How can I define a composite primary key in SQL?

Just for clarification: a table can have at most one primary key. A primary key consists of one or more columns (from that table). If a primary key consists of two or more columns it is called a composite primary key. It is defined as follows:

CREATE TABLE voting (
  QuestionID NUMERIC,
  MemberID NUMERIC,
  PRIMARY KEY (QuestionID, MemberID)
);

The pair (QuestionID,MemberID) must then be unique for the table and neither value can be NULL. If you do a query like this:

SELECT * FROM voting WHERE QuestionID = 7

it will use the primary key's index. If however you do this:

SELECT * FROM voting WHERE MemberID = 7

it won't because to use a composite index requires using all the keys from the "left". If an index is on fields (A,B,C) and your criteria is on B and C then that index is of no use to you for that query. So choose from (QuestionID,MemberID) and (MemberID,QuestionID) whichever is most appropriate for how you will use the table.

If necessary, add an index on the other:

CREATE UNIQUE INDEX idx1 ON voting (MemberID, QuestionID);

How to change href of <a> tag on button click through javascript

<a href="#" id="a" onclick="ChangeHref()">1.Change 2.Go</a>

<script>
function ChangeHref(){
document.getElementById("a").setAttribute("onclick", "location.href='http://religiasatanista.ro'");
}
</script>

Align text to the bottom of a div

You now can do this with Flexbox justify-content: flex-end now:

_x000D_

div {_x000D_
  display: flex;_x000D_
  justify-content: flex-end;_x000D_
  align-items: flex-end;_x000D_
  width: 150px;_x000D_
  height: 150px;_x000D_
  border: solid 1px red;_x000D_
}_x000D_

_x000D_

<div>_x000D_
  Something to align_x000D_
</div>

_x000D_

Consult your Caniuse to see if Flexbox is right for you.

How to create a sticky footer that plays well with Bootstrap 3

The answer, as Schmalzy points out, can be found here in the examples section of the getbootstrap site.

But that example does not include a top nav. For fixed top nav with sticky footer, see this plnkr, or code below.

Style CSS:

/* Styles go here */

/* Sticky footer styles
-------------------------------------------------- */

html,
body {
  height: 100%;
  /* The html and body elements cannot have any padding or margin. */
}

/* Wrapper for page content to push down footer */
#wrap {
  min-height: 100%;
  height: auto;
  /* Negative indent footer by its height */
  margin: 0 auto -60px;
  /* Pad bottom by footer height */
  padding: 0 0 60px;
}

/* Set the fixed height of the footer here */
#footer {
  height: 60px;
  background-color: #f5f5f5;
}


/* Custom page CSS
-------------------------------------------------- */
/* Not required for template or sticky footer method. */

.container {
  width: auto;
  max-width: 680px;
  padding: 0 15px;
}
.container .credit {
  margin: 20px 0;
}

Index.html:

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="description" content="">
    <meta name="author" content="">
    <link rel="shortcut icon" href="../../docs-assets/ico/favicon.png">

    <title>Sticky Footer Template for Bootstrap</title>

    <!-- Bootstrap core CSS -->
    <link href="//netdna.bootstrapcdn.com/bootstrap/3.0.1/css/bootstrap.min.css" rel="stylesheet">

    <!-- Custom styles for this template -->
    <link href="style.css" rel="stylesheet">

    <!-- Just for debugging purposes. Don't actually copy this line! -->
    <!--[if lt IE 9]><script src="../../docs-assets/js/ie8-responsive-file-warning.js"></script><![endif]-->

    <!-- HTML5 shim and Respond.js IE8 support of HTML5 elements and media queries -->
    <!--[if lt IE 9]>
      <script src="https://oss.maxcdn.com/libs/html5shiv/3.7.0/html5shiv.js"></script>
      <script src="https://oss.maxcdn.com/libs/respond.js/1.3.0/respond.min.js"></script>
    <![endif]-->
  </head>

  <body>

    <!-- Wrap all page content here -->
    <div id="wrap">

<nav class="navbar navbar-default" role="navigation">
  <!-- Brand and toggle get grouped for better mobile display -->
  <div class="navbar-header">
    <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1">
      <span class="sr-only">Toggle navigation</span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
    </button>
    <a class="navbar-brand" href="#">Brand</a>
  </div>

  <!-- Collect the nav links, forms, and other content for toggling -->
  <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
    <ul class="nav navbar-nav">
      <li class="active"><a href="#">Link</a></li>
      <li><a href="#">Link</a></li>
      <li class="dropdown">
        <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown <b class="caret"></b></a>
        <ul class="dropdown-menu">
          <li><a href="#">Action</a></li>
          <li><a href="#">Another action</a></li>
          <li><a href="#">Something else here</a></li>
          <li class="divider"></li>
          <li><a href="#">Separated link</a></li>
          <li class="divider"></li>
          <li><a href="#">One more separated link</a></li>
        </ul>
      </li>
    </ul>
    <form class="navbar-form navbar-left" role="search">
      <div class="form-group">
        <input type="text" class="form-control" placeholder="Search">
      </div>
      <button type="submit" class="btn btn-default">Submit</button>
    </form>
    <ul class="nav navbar-nav navbar-right">
      <li><a href="#">Link</a></li>
      <li class="dropdown">
        <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown <b class="caret"></b></a>
        <ul class="dropdown-menu">
          <li><a href="#">Action</a></li>
          <li><a href="#">Another action</a></li>
          <li><a href="#">Something else here</a></li>
          <li class="divider"></li>
          <li><a href="#">Separated link</a></li>
        </ul>
      </li>
    </ul>
  </div><!-- /.navbar-collapse -->
</nav>

      <!-- Begin page content -->
      <div class="container">

        <div class="page-header">
          <h1>Sticky footer</h1>
        </div>
        <p class="lead">Pin a fixed-height footer to the bottom of the viewport in desktop browsers with this custom HTML and CSS.</p>
        <p>Use <a href="../sticky-footer-navbar">the sticky footer with a fixed navbar</a> if need be, too.</p>
      </div>
    </div><!-- Wrap Div end -->

    <div id="footer">
      <div class="container">
        <p class="text-muted credit">Example courtesy <a href="http://martinbean.co.uk">Martin Bean</a> and <a href="http://ryanfait.com/sticky-footer/">Ryan Fait</a>.</p>
      </div>
    </div>


    <!-- Bootstrap core JavaScript
    ================================================== -->
    <!-- Placed at the end of the document so the pages load faster -->
  </body>
</html>

Example for boost shared_mutex (multiple reads/one write)?

Since C++ 17 (VS2015) you can use the standard for read-write locks:

#include <shared_mutex>

typedef std::shared_mutex Lock;
typedef std::unique_lock< Lock > WriteLock;
typedef std::shared_lock< Lock > ReadLock;

Lock myLock;


void ReadFunction()
{
    ReadLock r_lock(myLock);
    //Do reader stuff
}

void WriteFunction()
{
     WriteLock w_lock(myLock);
     //Do writer stuff
}

For older version, you can use boost with the same syntax:

#include <boost/thread/locks.hpp>
#include <boost/thread/shared_mutex.hpp>

typedef boost::shared_mutex Lock;
typedef boost::unique_lock< Lock >  WriteLock;
typedef boost::shared_lock< Lock >  ReadLock;

Convert 4 bytes to int

You can also use BigInteger for variable length bytes. You can convert it to Long, Integer or Short, whichever suits your needs.

new BigInteger(bytes).intValue();

or to denote polarity:

new BigInteger(1, bytes).intValue();

How do I get client IP address in ASP.NET CORE?

The API has been updated. Not sure when it changed but according to Damien Edwards in late December, you can now do this:

var remoteIpAddress = request.HttpContext.Connection.RemoteIpAddress;

How to replace (null) values with 0 output in PIVOT

Sometimes it's better to think like a parser, like T-SQL parser. While executing the statement, parser does not have any value in Pivot section and you can't have any check expression in that section. By the way, you can simply use this:

SELECT  CLASS
,   IsNull([AZ], 0)
,   IsNull([CA], 0)
,   IsNull([TX], 0)
    FROM #TEMP
    PIVOT (
        SUM(DATA)
        FOR STATE IN (
            [AZ]
        ,   [CA]
        ,   [TX]
        )
    )   AS  PVT
    ORDER   BY  CLASS

How to start IDLE (Python editor) without using the shortcut on Windows Vista?

Another option for Windows that will automatically use the most recent version of Python installed, and also doesn't make you look for the installation path:

Target: pyw -m idlelib
Start in: Wherever you want

What is LDAP used for?

In Windows Server LDAP is a protocol which is used for access Active Directory object, user authentication, authorization.

Python ValueError: too many values to unpack

self.materials is a dict and by default you are iterating over just the keys (which are strings).

Since self.materials has more than two keys*, they can't be unpacked into the tuple "k, m", hence the ValueError exception is raised.

In Python 2.x, to iterate over the keys and the values (the tuple "k, m"), we use self.materials.iteritems().

However, since you're throwing the key away anyway, you may as well simply iterate over the dictionary's values:

for m in self.materials.itervalues():

In Python 3.x, prefer dict.values() (which returns a dictionary view object):

for m in self.materials.values():

Using boolean values in C

A few thoughts on booleans in C:

I'm old enough that I just use plain ints as my boolean type without any typedefs or special defines or enums for true/false values. If you follow my suggestion below on never comparing against boolean constants, then you only need to use 0/1 to initialize the flags anyway. However, such an approach may be deemed too reactionary in these modern times. In that case, one should definitely use <stdbool.h> since it at least has the benefit of being standardized.

Whatever the boolean constants are called, use them only for initialization. Never ever write something like

if (ready == TRUE) ...
while (empty == FALSE) ...

These can always be replaced by the clearer

if (ready) ...
while (!empty) ...

Note that these can actually reasonably and understandably be read out loud.

Give your boolean variables positive names, ie full instead of notfull. The latter leads to code that is difficult to read easily. Compare

if (full) ...
if (!full) ...

with

if (!notfull) ...
if (notfull) ...

Both of the former pair read naturally, while !notfull is awkward to read even as it is, and becomes much worse in more complex boolean expressions.

Boolean arguments should generally be avoided. Consider a function defined like this

void foo(bool option) { ... }

Within the body of the function, it is very clear what the argument means since it has a convenient, and hopefully meaningful, name. But, the call sites look like

foo(TRUE);
foo(FALSE):

Here, it's essentially impossible to tell what the parameter meant without always looking at the function definition or declaration, and it gets much worse as soon if you add even more boolean parameters. I suggest either

typedef enum { OPT_ON, OPT_OFF } foo_option;
void foo(foo_option option);

#define OPT_ON true
#define OPT_OFF false
void foo(bool option) { ... }

In either case, the call site now looks like

foo(OPT_ON);
foo(OPT_OFF);

which the reader has at least a chance of understanding without dredging up the definition of foo.

Javascript: The prettiest way to compare one value against multiple values

Just for kicks, since this Q&A does seem to be about syntax microanalysis, a tiny tiny modification of André Alçada Padez's suggestion(s):

(and of course accounting for the pre-IE9 shim/shiv/polyfill he's included)

if (~[foo, bar].indexOf(foobar)) {
    // pretty
}

What is ' and why does Google search replace it with apostrophe?

It's HTML character references for encoding a character by its decimal code point

Look at the ASCII table here and you'll see that 39 (hex 0x27, octal 47) is the code for apostrophe

How to parse a string in JavaScript?

as amber and sinan have noted above, the javascritp '.split' method will work just fine. Just pass it the string separator(-) and the string that you intend to split('123-abc-itchy-knee') and it will do the rest.

    var coolVar = '123-abc-itchy-knee';
    var coolVarParts = coolVar.split('-'); // this is an array containing the items

    var1=coolVarParts[0]; //this will retrieve 123

To access each item from the array just use the respective index(indices start at zero).

How can I get the content of CKEditor using JQuery?

I think it will be better, just serialize your form by jquery and cheers...

<form id="ajxForm">
  <!-- input elments here -->
  <textarea id="ck-editor" name="ck-editor" required></textarea>
  <input name="text" id="text" type="text" required> 
<form>

and In javascript section

CKEDITOR.replace('ck-editor', {
  extraPlugins: 'sourcedialog',
  removePlugins: 'sourcearea'
});

$("form#ajxForm").submit(function(e) {
  e.preventDefault();
  var data = $(this).serialize();
  if (data != '') {
    $.ajax({
      url: 'post.php',
      cache: false,
      type: 'POST',
      data: data,
      success: function(e) {
        setTimeout(function() {
          alert(e);
        }, 6500);
      }
    });
  }
  return;
});

How to remove part of a string before a ":" in javascript?

There is no need for jQuery here, regular JavaScript will do:

var str = "Abc: Lorem ipsum sit amet";
str = str.substring(str.indexOf(":") + 1);

Or, the .split() and .pop() version:

var str = "Abc: Lorem ipsum sit amet";
str = str.split(":").pop();

Or, the regex version (several variants of this):

var str = "Abc: Lorem ipsum sit amet";
str = /:(.+)/.exec(str)[1];

Bootstrap get div to align in the center

When I align elements in center I use the bootstrap class text-center:

<div class="text-center">Centered content goes here</div>

Selecting all text in HTML text input when clicked

If anyone want to do this on page load w/ jQuery (sweet for search fields) here is my solution

jQuery.fn.focusAndSelect = function() {
    return this.each(function() {
        $(this).focus();
        if (this.setSelectionRange) {
            var len = $(this).val().length * 2;
            this.setSelectionRange(0, len);
        } else {
            $(this).val($(this).val());
        }
        this.scrollTop = 999999;
    });
};

(function ($) {
    $('#input').focusAndSelect();
})(jQuery);

Based on this post . Thanks to CSS-Tricks.com

Could not load file or assembly System.Web.Http.WebHost after published to Azure web site

The dll is missing in the published (deployed environment). That is the reason why it is working in the local i.e. Visual Studio but not in the Azure Website Environment.

Just do Copy Local = true in the properties for the assembly(System.Web.Http.WebHost) and then do a redeploy, it should work fine.

When should I use a struct rather than a class in C#?

Here is a basic rule.

If all member fields are value types create a struct.
If any one member field is a reference type, create a class. This is because the reference type field will need the heap allocation anyway.

Exmaples

public struct MyPoint 
{
    public int X; // Value Type
    public int Y; // Value Type
}

public class MyPointWithName 
{
    public int X; // Value Type
    public int Y; // Value Type
    public string Name; // Reference Type
}

AWS ssh access 'Permission denied (publickey)' issue

For Ubuntu instances:

chmod 600 ec2-keypair.pem
ssh -v -i ec2-keypair.pem [email protected]

For other instances, you might have to use ec2-user instead of ubuntu.

Most EC2 Linux images I've used only have the root user created by default.

Database, Table and Column Naming Conventions?

I work in a database support team with three DBAs and our considered options are:

Any naming standard is better than no standard.
There is no "one true" standard, we all have our preferences
If there is standard already in place, use it. Don't create another standard or muddy the existing standards.

We use singular names for tables. Tables tend to be prefixed with the name of the system (or its acronym). This is useful if the system complex as you can change the prefix to group the tables together logically (ie. reg_customer, reg_booking and regadmin_limits).

For fields we'd expect field names to be include the prefix/acryonm of the table (i.e. cust_address1) and we also prefer the use of a standard set of suffixes ( _id for the PK, _cd for "code", _nm for "name", _nb for "number", _dt for "Date").

The name of the Foriegn key field should be the same as the Primary key field.

i.e.

SELECT cust_nm, cust_add1, booking_dt
FROM reg_customer
INNER JOIN reg_booking
ON reg_customer.cust_id = reg_booking.cust_id

When developing a new project, I'd recommend you write out all the preferred entity names, prefixes and acronyms and give this document to your developers. Then, when they decide to create a new table, they can refer to the document rather than "guess" what the table and fields should be called.

Browser can't access/find relative resources like CSS, images and links when calling a Servlet which forwards to a JSP

You can try out this one as well as. Because this worked for me and it's simple.

<style>
    <%@ include file="/css/style.css" %>
</style>

How can I easily view the contents of a datatable or dataview in the immediate window

and if you want this anywhere... to be a helper on DataTable this assumes you want to capture the output to Log4Net but the excellent starting example I worked against just dumps to the console... This one also has editable column width variable nMaxColWidth - ultimately I will pass that from whatever context...

public static class Helpers
    {
        private static ILog Log = Global.Log ?? LogManager.GetLogger("MyLogger");
        /// <summary>
        /// Dump contents of a DataTable to the log
        /// </summary>
        /// <param name="table"></param>
        public static void DebugTable(this DataTable table)
        {
            Log?.Debug("--- DebugTable(" + table.TableName + ") ---");
            var nRows = table.Rows.Count;
            var nCols = table.Columns.Count;
            var nMaxColWidth = 32;

            // Column Headers

            var sColFormat = @"{0,-" + nMaxColWidth + @"} | ";
            var sLogMessage = string.Empty;
            for (var i = 0; i < table.Columns.Count; i++)
            {
                sLogMessage = string.Concat(sLogMessage, string.Format(sColFormat, table.Columns[i].ToString()));
            }
            //Debug.Write(Environment.NewLine);
            Log?.Debug(sLogMessage);

            var sUnderScore = string.Empty;
            var sDashes = string.Empty;
            for (var j = 0; j <= nMaxColWidth; j++)
            {
                sDashes = sDashes + "-";
            }


            for (var i = 0; i < table.Columns.Count; i++)
            {
                sUnderScore = string.Concat(sUnderScore, sDashes + "|-");
            }

            sUnderScore = sUnderScore.TrimEnd('-');

            //Debug.Write(Environment.NewLine);
            Log?.Debug(sUnderScore);

            // Data
            for (var i = 0; i < nRows; i++)
            {
                DataRow row = table.Rows[i];
                //Debug.WriteLine("{0} {1} ", row[0], row[1]);
                sLogMessage = string.Empty;

                for (var j = 0; j < nCols; j++)
                {
                    string s = row[j].ToString();
                    if (s.Length > nMaxColWidth) s = s.Substring(0, nMaxColWidth - 3) + "...";
                    sLogMessage = string.Concat(sLogMessage, string.Format(sColFormat, s));
                }

                Log?.Debug(sLogMessage);
                //Debug.Write(Environment.NewLine);
            }           
            Log?.Debug(sUnderScore);
        }
}

Assign variable value inside if-statement

Yes, it is possible to assign inside if conditional check. But, your variable should have already been declared to assign something.

How can I get list of values from dict?

You can use * operator to unpack dict_values:

>>> d = {1: "a", 2: "b"}
>>> [*d.values()]
['a', 'b']

or list object

>>> d = {1: "a", 2: "b"}
>>> list(d.values())
['a', 'b']

How to list only top level directories in Python?

Using list comprehension,

[a for a in os.listdir() if os.path.isdir(a)]

I think It is the simplest way

TypeError: 'list' object cannot be interpreted as an integer

remove the range.

for i in myList

range takes in an integer. you want for each element in the list.

Prevent BODY from scrolling when a modal is opened

React , if you are looking for

useEffect in the modal that is getting popedup

 useEffect(() => {
    document.body.style.overflowY = 'hidden';
    return () =>{
      document.body.style.overflowY = 'auto';
    }
  }, [])

How to use absolute path in twig functions

Symfony 2.7 has a new absolute_url which can be used to generate the absolute url. http://symfony.com/blog/new-in-symfony-2-7-the-new-asset-component#template-function-changes

It will work on those both cases or a path string:

<a href="{{ absolute_url(path('route_name', {'param' : value})) }}">A link</a>

and for assets:

<img src="{{ absolute_url(asset('bundle/myname/img/image.gif')) }}" alt="Title"/>

Or for any string path

<img src="{{ absolute_url('my/absolute/path') }}" alt="Title"/>

on those tree cases you will end up with an absolute URL like

http://www.example.com/my/absolute/path

Uncaught TypeError: Cannot read property 'top' of undefined

I know this is extremely old, but I understand that this error type is a common mistake for beginners to make since most beginners will call their functions upon their header element being loaded. Seeing as this solution is not addressed at all in this thread, I'll add it. It is very likely that this javascript function was placed before the actual html was loaded. Remember, if you immediately call your javascript before the document is ready then elements requiring an element from the document might find an undefined value.

'cl' is not recognized as an internal or external command,

I had the same problem and I solved it by switching to MinGW from MSVC2010.

Select the Project Tab from your left pane. Then select the "Target". From there change Qt version to MinGW instead of VC++.

What are the differences between a superkey and a candidate key?

Super key: super key is a set of atttibutes in a relation(table).which can define every tupple in the relation(table) uniquely.

Candidate key: we can say minimal super key is candidate key. Candidate is the smallest sub set of super key. And can uniquely define each and every tupple.

Can't clone a github repo on Linux via HTTPS

Make sure you have git 1.7.10 or later, it now prompts for user/password correctly. (You can download the latest version here)

Cannot implicitly convert type from Task<>

The main issue with your example that you can't implicitly convert Task<T> return types to the base T type. You need to use the Task.Result property. Note that Task.Result will block async code, and should be used carefully.

Try this instead:

public List<int> TestGetMethod()  
{  
    return GetIdList().Result;  
}

Search for executable files using find command

Well the easy answer would be: "your executable files are in the directories contained in your PATH variable" but that would not really find your executables and could miss a lot of executables anyway.

I don't know much about mac but I think "mdfind 'kMDItemContentType=public.unix-executable'" might miss stuff like interpreted scripts

If it's ok for you to find files with the executable bits set (regardless of whether they are actually executable) then it's fine to do

find . -type f -perm +111 -print

where supported the "-executable" option will make a further filter looking at acl and other permission artifacts but is technically not much different to "-pemr +111".

Maybe in the future find will support "-magic " and let you look explicitly for files with a specific magic id ... but then you would haveto specify to fine all the executable formats magic id.

I'm unaware of a technically correct easy way out on unix.

check if jquery has been loaded, then load it if false

Maybe something like this:

<script>
if(!window.jQuery)
{
   var script = document.createElement('script');
   script.type = "text/javascript";
   script.src = "path/to/jQuery";
   document.getElementsByTagName('head')[0].appendChild(script);
}
</script>

Python find min max and average of a list (array)

Only a teacher would ask you to do something silly like this. You could provide an expected answer. Or a unique solution, while the rest of the class will be (yawn) the same...

from operator import lt, gt
def ultimate (l,op,c=1,u=0):
    try:
        if op(l[c],l[u]): 
            u = c
        c += 1
        return ultimate(l,op,c,u)
    except IndexError:
        return l[u]
def minimum (l):
    return ultimate(l,lt)
def maximum (l):
    return ultimate(l,gt)

The solution is simple. Use this to set yourself apart from obvious choices.

Check if a number is odd or even in python

It shouldn't matter if the word has an even or odd amount fo letters:

def is_palindrome(word):
    if word == word[::-1]:
        return True
    else:
        return False

how to permit an array with strong parameters

If you want to permit an array of hashes(or an array of objects from the perspective of JSON)

params.permit(:foo, array: [:key1, :key2])

2 points to notice here:

array should be the last argument of the permit method.
you should specify keys of the hash in the array, otherwise you will get an error Unpermitted parameter: array, which is very difficult to debug in this case.

Dynamically add properties to a existing object

If you can't use the dynamic type with ExpandoObject, then you could use a 'Property Bag' mechanism, where, using a dictionary (or some other key / value collection type) you store string key's that name the properties and values of the required type.

See here for an example implementation.

Fatal error: Cannot use object of type stdClass as array in

if you really want an array instead you can use:

$getvidids->result_array()

which would return the same information as an associative array.

Simple Android grid example using RecyclerView with GridLayoutManager (like the old GridView)

Set in RecyclerView initialization

recyclerView.setLayoutManager(new GridLayoutManager(this, 4));

How to change the default port of mysql from 3306 to 3360

In Windows 8.1 x64 bit os, Currently I am using MySQL version :

Server version: 5.7.11-log MySQL Community Server (GPL)

For changing your MySQL port number, Go to installation directory, my installation directory is :

C:\Program Files\MySQL\MySQL Server 5.7

open the my-default.ini Configuration Setting file in any text editor.

search the line in the configuration file.

# port = .....

replace it with :

port=<my_new_port_number>

like my self changed to :

port=15800

To apply the changes don't forget to immediate either restart the MySQL Server or your OS.

Hope this would help many one.

What does "Error: object '<myvariable>' not found" mean?

The error means that R could not find the variable mentioned in the error message.

The easiest way to reproduce the error is to type the name of a variable that doesn't exist. (If you've defined x already, use a different variable name.)

x
## Error: object 'x' not found

The more complex version of the error has the same cause: calling a function when x does not exist.

mean(x)
## Error in mean(x) : 
##   error in evaluating the argument 'x' in selecting a method for function 'mean': Error: object 'x' not found

Once the variable has been defined, the error will not occur.

x <- 1:5
x
## [1] 1 2 3 4 5     
mean(x)
## [1] 3

You can check to see if a variable exists using ls or exists.

ls()        # lists all the variables that have been defined
exists("x") # returns TRUE or FALSE, depending upon whether x has been defined.

Errors like this can occur when you are using non-standard evaluation. For example, when using subset, the error will occur if a column name is not present in the data frame to subset.

d <- data.frame(a = rnorm(5))
subset(d, b > 0)
## Error in eval(expr, envir, enclos) : object 'b' not found

The error can also occur if you use custom evaluation.

get("var", "package:stats") #returns the var function
get("var", "package:utils")
## Error in get("var", "package:utils") : object 'var' not found

In the second case, the var function cannot be found when R looks in the utils package's environment because utils is further down the search list than stats.

In more advanced use cases, you may wish to read:

The Scope section of the CRAN manual Intro to R and demo(scoping)
The Non-standard evaluation chapter of Advanced R

Chrome Dev Tools - Modify javascript and reload

Yes, just open the "Source" Tab in the dev-tools and navigate to the script you want to change . Make your adjustments directly in the dev tools window and then hit ctrl+s to save the script - know the new js will be used until you refresh the whole page.

How to set the color of an icon in Angular Material?

Since for some reason white isn't available for selection, I have found that mat-palette($mat-grey, 50) was close enough to white, for my needs at least.

Adding 30 minutes to time formatted as H:i in PHP

$time = strtotime('10:00');
$startTime = date("H:i", strtotime('-30 minutes', $time));
$endTime = date("H:i", strtotime('+30 minutes', $time));

How do I find out which computer is the domain controller in Windows programmatically?

With the most simple programming language: DOS batch

echo %LOGONSERVER%

Is there any good dynamic SQL builder library in Java?

Hibernate Criteria API (not plain SQL though, but very powerful and in active development):

List sales = session.createCriteria(Sale.class)
         .add(Expression.ge("date",startDate);
         .add(Expression.le("date",endDate);
         .addOrder( Order.asc("date") )
         .setFirstResult(0)
         .setMaxResults(10)
         .list();

How do I set up Visual Studio Code to compile C++ code?

If your project has a CMake configuration it's pretty straight forward to setup VSCode, e.g. setup tasks.json like below:

{
    "version": "0.1.0",
    "command": "sh",
    "isShellCommand": true,
    "args": ["-c"],
    "showOutput": "always",
    "suppressTaskName": true,
    "options": {
        "cwd": "${workspaceRoot}/build"
    },
    "tasks": [
        {
            "taskName": "cmake",
            "args": ["cmake ."]
        },
        {
            "taskName": "make",
            "args" : ["make"],
            "isBuildCommand": true,
            "problemMatcher": {
                "owner": "cpp",
                "fileLocation": "absolute",
                "pattern": {
                    "regexp": "^(.*):(\\d+):(\\d+):\\s+(warning|error):\\s+(.*)$",
                    "file": 1,
                    "line": 2,
                    "column": 3,
                    "severity": 4,
                    "message": 5
                }
            }
        }
    ]
}

This assumes that there is a folder build in the root of the workspace with a CMake configuration.

There's also a CMake integration extension that adds a "CMake build" command to VScode.

PS! The problemMatcher is setup for clang-builds. To use GCC I believe you need to change fileLocation to relative, but I haven't tested this.

Table and Index size in SQL Server

To see a single table's (and its indexes) storage data:

exec sp_spaceused MyTable

What is a 'workspace' in Visual Studio Code?

The main utility of a workspace (and maybe the only one) is to allow to add multiple independent folders that compounds a project. For example:

- WorkspaceProjectX  
-- ApiFolder   (maybe /usr/share/www/api)  
-- DocsFolder  (maybe /home/user/projx/html/docs)  
-- WebFolder   (maybe /usr/share/www/web)

So you can group those in a work space for a specific project instead of have to open multiple folders windows.

You can learn more here.

Unknown version of Tomcat was specified in Eclipse

You are specifying tomcat source directory.

You need to specify tomcat binary installation root directory, also known as CATALINA_HOME.

Usually, this is where you untar apache-tomcat-7.0.42.tar.gz file.

Apply CSS rules to a nested class inside a div

If you need to target multiple classes use:

#main_text .title, #main_text .title2 {
  /* Properties */
}

NoClassDefFoundError on Maven dependency

I was able to work around it by running mvn install:install-file with -Dpackaging=class. Then adding entry to POM as described here:

Array to Collection: Optimized code

Another way to do it:

Collections.addAll(collectionInstance,array);

String escape into XML

George, it's simple. Always use the XML APIs to handle XML. They do all the escaping and unescaping for you.

Never create XML by appending strings.

Error in <my code> : object of type 'closure' is not subsettable

I had this issue was trying to remove a ui element inside an event reactive:

myReactives <- eventReactive(input$execute, {
    ... # Some other long running function here
    removeUI(selector = "#placeholder2")
})

I was getting this error, but not on the removeUI element line, it was in the next observer after for some reason. Taking the removeUI method out of the eventReactive and placing it somewhere else removed this error for me.

Disable scrolling when touch moving certain element

Note: As pointed out in the comments by @nevf, this solution may no longer work (at least in Chrome) due to performance changes. The recommendation is to use touch-action which is also suggested by @JohnWeisz's answer.

Similar to the answer given by @Llepwryd, I used a combination of ontouchstart and ontouchmove to prevent scrolling when it is on a certain element.

Taken as-is from a project of mine:

window.blockMenuHeaderScroll = false;
$(window).on('touchstart', function(e)
{
    if ($(e.target).closest('#mobileMenuHeader').length == 1)
    {
        blockMenuHeaderScroll = true;
    }
});
$(window).on('touchend', function()
{
    blockMenuHeaderScroll = false;
});
$(window).on('touchmove', function(e)
{
    if (blockMenuHeaderScroll)
    {
        e.preventDefault();
    }
});

Essentially, what I am doing is listening on the touch start to see whether it begins on an element that is a child of another using jQuery .closest and allowing that to turn on/off the touch movement doing scrolling. The e.target refers to the element that the touch start begins with.

You want to prevent the default on the touch move event however you also need to clear your flag for this at the end of the touch event otherwise no touch scroll events will work.

This can be accomplished without jQuery however for my usage, I already had jQuery and didn't need to code something up to find whether the element has a particular parent.

Tested in Chrome on Android and an iPod Touch as of 2013-06-18

How to calculate rolling / moving average using NumPy / SciPy?

By comparing the solution below with the one that uses cumsum of numpy, This one takes almost half the time. This is because it does not need to go through the entire array to do the cumsum and then do all the subtraction. Moreover, the cumsum can be "dangerous" if the array is huge and the number are huge (possible overflow). Of course, also here the danger exists but at least are summed together only the essential numbers.

def moving_average(array_numbers, n):
    if n > len(array_numbers):
      return []
    temp_sum = sum(array_numbers[:n])
    averages = [temp_sum / float(n)]
    for first_index, item in enumerate(array_numbers[n:]):
        temp_sum += item - array_numbers[first_index]
        averages.append(temp_sum / float(n))
    return averages

Recursively add the entire folder to a repository

Navigate to the folder where you have your files
if you are on a windows machine you will need to start git bash from which you will get a command line interface then use these commands

git init   //this initializes a .git  repository in your working directory

git remote add origin <URL_TO_YOUR_REPO.git> // this points to correct repository where files will be uploaded

git add *   // this adds all the files to the initialialized git repository

if you make any changes to the files before merging it to the master you have to commit the changes by executing

git commit -m "applied some changes to the branch"

After this checkout the branch to the master branch

What is the meaning of @_ in Perl?

perldoc perlvar is the first place to check for any special-named Perl variable info.

Quoting:

@_: Within a subroutine the array @_ contains the parameters passed to that subroutine.

More details can be found in perldoc perlsub (Perl subroutines) linked from the perlvar:

Any arguments passed in show up in the array @_ .

Therefore, if you called a function with two arguments, those would be stored in $_[0] and $_[1].

The array @_ is a local array, but its elements are aliases for the actual scalar parameters. In particular, if an element $_[0] is updated, the corresponding argument is updated (or an error occurs if it is not updatable).

If an argument is an array or hash element which did not exist when the function was called, that element is created only when (and if) it is modified or a reference to it is taken. (Some earlier versions of Perl created the element whether or not the element was assigned to.) Assigning to the whole array @_ removes that aliasing, and does not update any arguments.

MySQL Server has gone away when importing large sql file

I got same issue with

$image_base64 = base64_encode(file_get_contents($_FILES['file']['tmp_name']) );
$image = 'data:image/jpeg;base64,'.$image_base64;
$query = "insert into images(image) values('".$image."')";
mysqli_query($con,$query);

In \xampp\mysql\bin\my.ini file of phpmyadmin we get only

[mysqldump]
max_allowed_packet=110M

which is just for mysqldump -u root -p dbname . I resolved my issue by replacing above code with

max_allowed_packet=110M
[mysqldump]
max_allowed_packet=110M

How do you add a scroll bar to a div?

<div class="scrollingDiv">foo</div> 

div.scrollingDiv
{
   overflow:scroll;
}

make iframe height dynamic based on content inside- JQUERY/Javascript

in my project there is one requirement that we have make dynamic screen like Alignment of Dashboard while loading, it should display on an entire page and should get adjust dynamically, if user is maximizing or resizing the browser’s window. For this I have created url and used iframe to open one of the dynamic report which is written in cognos BI.In jsp we have to embed BI report. I have used iframe to embed this report in jsp. following code is working in my case.

<iframe src= ${cognosUrl} onload="this.style.height=(this.contentDocument.body.scrollHeight+30) +'px';" scrolling="no" style="width: 100%; min-height: 900px; border: none; overflow: hidden; height: 30px;"></iframe>

Twitter - How to embed native video from someone else's tweet into a New Tweet or a DM

I eventually figured out an easy way to do it:

On your Twitter feed, click the date/time of the tweet containing the video. That will open the single tweet view
Look for the down-pointing arrow at the top-right corner of the tweet, click it to open drop-down menue
Select the "Embed Video" option and copy the HTML embed code and Paste it to Notepad
Find the last "t.co" shortened URL inside the HTML code (should be something like this: https://``t.co/tQM43ftXyM). Copy this URL and paste it in a new browser tab.
The browser will expand the shortened URL to something which looks like this: https://twitter.com/UserName/status/828267001496784896/video/1

This is the link to the Twitter Card containing the native video. Pasting this link in a new tweet or DM will include the native video in it!

Trigger change() event when setting <select>'s value with val() function

I separate it, and then use an identity comparison to dictate what is does next.

$("#selectField").change(function(){
  if(this.value === 'textValue1'){ $(".contentClass1").fadeIn(); }
  if(this.value === 'textValue2'){ $(".contentclass2").fadeIn(); }
});

How to parse this string in Java?

String str = "/usr/local/apache/resumes/dir1/dir2";
String prefix = "/usr/local/apache/resumes/";

if( str.startsWith(prefix) ) {
  str = str.substring(0, prefix.length);
  String parts[] = str.split("/");
  // dir1=parts[0];
  // dir2=parts[1];
} else {
  // It doesn't start with your prefix
}

What are intent-filters in Android?

When you create an implicit intent, the Android system finds the appropriate component to start by comparing the contents of the intent to the intent filters declared in the manifest file of other apps on the device. If the intent matches an intent filter, the system starts that component and delivers it the Intent object. If multiple intent filters are compatible, the system displays a dialog so the user can pick which app to use.

An intent filter is an expression in an app's manifest file that specifies the type of intents that the component would like to receive. For instance, by declaring an intent filter for an activity, you make it possible for other apps to directly start your activity with a certain kind of intent. Likewise, if you do not declare any intent filters for an activity, then it can be started only with an explicit intent.

According: Intents and Intent Filters

c++ "Incomplete type not allowed" error accessing class reference information (Circular dependency with forward declaration)

If you will place your definitions in this order then the code will be compiled

class Ball;

class Player {
public:
    void doSomething(Ball& ball);
private:
};

class Ball {
public:
    Player& PlayerB;
    float ballPosX = 800;
private:

};

void Player::doSomething(Ball& ball) {
    ball.ballPosX += 10;                   // incomplete type error occurs here.
}

int main()
{
}

The definition of function doSomething requires the complete definition of class Ball because it access its data member.

In your code example module Player.cpp has no access to the definition of class Ball so the compiler issues an error.

How to rename a table column in Oracle 10g

The syntax of the query is as follows:

Alter table <table name> rename column <column name> to <new column name>;

Example:

Alter table employee rename column eName to empName;

To rename a column name without space to a column name with space:

Alter table employee rename column empName to "Emp Name";

To rename a column with space to a column name without space:

Alter table employee rename column "emp name" to empName;

How to have multiple conditions for one if statement in python

Assuming you're passing in strings rather than integers, try casting the arguments to integers:

def example(arg1, arg2, arg3):
     if int(arg1) == 1 and int(arg2) == 2 and int(arg3) == 3:
          print("Example Text")

(Edited to emphasize I'm not asking for clarification; I was trying to be diplomatic in my answer. )

Mocking methods of local scope objects with Mockito

You could avoid changing the code (although I recommend Boris' answer) and mock the constructor, like in this example for mocking the creation of a File object inside a method. Don't forget to put the class that will create the file in the @PrepareForTest.

package hello.easymock.constructor;

import java.io.File;

import org.easymock.EasyMock;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.easymock.PowerMock;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
    
@RunWith(PowerMockRunner.class)
@PrepareForTest({File.class})
public class ConstructorExampleTest {
        
    @Test
    public void testMockFile() throws Exception {

        // first, create a mock for File
        final File fileMock = EasyMock.createMock(File.class);
        EasyMock.expect(fileMock.getAbsolutePath()).andReturn("/my/fake/file/path");
        EasyMock.replay(fileMock);

        // then return the mocked object if the constructor is invoked
        Class<?>[] parameterTypes = new Class[] { String.class };
        PowerMock.expectNew(File.class, parameterTypes , EasyMock.isA(String.class)).andReturn(fileMock);
        PowerMock.replay(File.class); 
    
        // try constructing a real File and check if the mock kicked in
        final String mockedFilePath = new File("/real/path/for/file").getAbsolutePath();
        Assert.assertEquals("/my/fake/file/path", mockedFilePath);
    }
}

What is the scope of variables in JavaScript?

TLDR

JavaScript has lexical (also called static) scoping and closures. This means you can tell the scope of an identifier by looking at the source code.

The four scopes are:

Global - visible by everything
Function - visible within a function (and its sub-functions and blocks)
Block - visible within a block (and its sub-blocks)
Module - visible within a module

Outside of the special cases of global and module scope, variables are declared using var (function scope), let (block scope), and const (block scope). Most other forms of identifier declaration have block scope in strict mode.

Overview

Scope is the region of the codebase over which an identifier is valid.

A lexical environment is a mapping between identifier names and the values associated with them.

Scope is formed of a linked nesting of lexical environments, with each level in the nesting corresponding to a lexical environment of an ancestor execution context.

These linked lexical environments form a scope "chain". Identifier resolution is the process of searching along this chain for a matching identifier.

Identifier resolution only occurs in one direction: outwards. In this way, outer lexical environments cannot "see" into inner lexical environments.

There are three pertinent factors in deciding the scope of an identifier in JavaScript:

How an identifier was declared
Where an identifier was declared
Whether you are in strict mode or non-strict mode

Some of the ways identifiers can be declared:

var, let and const
Function parameters
Catch block parameter
Function declarations
Named function expressions
Implicitly defined properties on the global object (i.e., missing out var in non-strict mode)
import statements
eval

Some of the locations identifiers can be declared:

Global context
Function body
Ordinary block
The top of a control structure (e.g., loop, if, while, etc.)
Control structure body
Modules

Declaration Styles

var

Identifiers declared using var have function scope, apart from when they are declared directly in the global context, in which case they are added as properties on the global object and have global scope. There are separate rules for their use in eval functions.

let and const

Identifiers declared using let and const have block scope, apart from when they are declared directly in the global context, in which case they have global scope.

Note: let, const and var are all hoisted. This means that their logical position of definition is the top of their enclosing scope (block or function). However, variables declared using let and const cannot be read or assigned to until control has passed the point of declaration in the source code. The interim period is known as the temporal dead zone.

_x000D_

function f() {
    function g() {
        console.log(x)
    }
    let x = 1
    g()
}
f() // 1 because x is hoisted even though declared with `let`!

_x000D_

Function parameter names

Function parameter names are scoped to the function body. Note that there is a slight complexity to this. Functions declared as default arguments close over the parameter list, and not the body of the function.

Function declarations

Function declarations have block scope in strict mode and function scope in non-strict mode. Note: non-strict mode is a complicated set of emergent rules based on the quirky historical implementations of different browsers.

Named function expressions

Named function expressions are scoped to themselves (e.g., for the purpose of recursion).

Implicitly defined properties on the global object

In non-strict mode, implicitly defined properties on the global object have global scope, because the global object sits at the top of the scope chain. In strict mode, these are not permitted.

eval

In eval strings, variables declared using var will be placed in the current scope, or, if eval is used indirectly, as properties on the global object.

Examples

The following will throw a ReferenceError because the namesx, y, and z have no meaning outside of the function f.

_x000D_

function f() {
    var x = 1
    let y = 1
    const z = 1
}
console.log(typeof x) // undefined (because var has function scope!)
console.log(typeof y) // undefined (because the body of the function is a block)
console.log(typeof z) // undefined (because the body of the function is a block)

_x000D_

The following will throw a ReferenceError for y and z, but not for x, because the visibility of x is not constrained by the block. Blocks that define the bodies of control structures like if, for, and while, behave similarly.

_x000D_

{
    var x = 1
    let y = 1
    const z = 1
}
console.log(x) // 1
console.log(typeof y) // undefined because `y` has block scope
console.log(typeof z) // undefined because `z` has block scope

_x000D_

In the following, x is visible outside of the loop because var has function scope:

_x000D_

for(var x = 0; x < 5; ++x) {}
console.log(x) // 5 (note this is outside the loop!)

_x000D_

...because of this behavior, you need to be careful about closing over variables declared using var in loops. There is only one instance of variable x declared here, and it sits logically outside of the loop.

The following prints 5, five times, and then prints 5 a sixth time for the console.log outside the loop:

_x000D_

for(var x = 0; x < 5; ++x) {
    setTimeout(() => console.log(x)) // closes over the `x` which is logically positioned at the top of the enclosing scope, above the loop
}
console.log(x) // note: visible outside the loop

_x000D_

The following prints undefined because x is block-scoped. The callbacks are run one by one asynchronously. New behavior for let variables means that each anonymous function closed over a different variable named x (unlike it would have done with var), and so integers 0 through 4 are printed.:

_x000D_

for(let x = 0; x < 5; ++x) {
    setTimeout(() => console.log(x)) // `let` declarations are re-declared on a per-iteration basis, so the closures capture different variables
}
console.log(typeof x) // undefined

_x000D_

The following will NOT throw a ReferenceError because the visibility of x is not constrained by the block; it will, however, print undefined because the variable has not been initialised (because of the if statement).

_x000D_

if(false) {
    var x = 1
}
console.log(x) // here, `x` has been declared, but not initialised

_x000D_

A variable declared at the top of a for loop using let is scoped to the body of the loop:

_x000D_

for(let x = 0; x < 10; ++x) {} 
console.log(typeof x) // undefined, because `x` is block-scoped

_x000D_

The following will throw a ReferenceError because the visibility of x is constrained by the block:

_x000D_

if(false) {
    let x = 1
}
console.log(typeof x) // undefined, because `x` is block-scoped

_x000D_

Variables declared using var, let or const are all scoped to modules:

// module1.js

var x = 0
export function f() {}

//module2.js

import f from 'module1.js'

console.log(x) // throws ReferenceError

The following will declare a property on the global object because variables declared using var within the global context are added as properties to the global object:

_x000D_

var x = 1
console.log(window.hasOwnProperty('x')) // true

_x000D_

let and const in the global context do not add properties to the global object, but still have global scope:

_x000D_

let x = 1
console.log(window.hasOwnProperty('x')) // false

_x000D_

Function parameters can be considered to be declared in the function body:

_x000D_

function f(x) {}
console.log(typeof x) // undefined, because `x` is scoped to the function

_x000D_

Catch block parameters are scoped to the catch-block body:

_x000D_

try {} catch(e) {}
console.log(typeof e) // undefined, because `e` is scoped to the catch block

_x000D_

Named function expressions are scoped only to the expression itself:

_x000D_

(function foo() { console.log(foo) })()
console.log(typeof foo) // undefined, because `foo` is scoped to its own expression

_x000D_

In non-strict mode, implicitly defined properties on the global object are globally scoped. In strict mode, you get an error.

_x000D_

x = 1 // implicitly defined property on the global object (no "var"!)

console.log(x) // 1
console.log(window.hasOwnProperty('x')) // true

_x000D_

In non-strict mode, function declarations have function scope. In strict mode, they have block scope.

_x000D_

'use strict'
{
    function foo() {}
}
console.log(typeof foo) // undefined, because `foo` is block-scoped

_x000D_

How it works under the hood

Scope is defined as the lexical region of code over which an identifier is valid.

In JavaScript, every function-object has a hidden [[Environment]] reference that is a reference to the lexical environment of the execution context (stack frame) within which it was created.

When you invoke a function, the hidden [[Call]] method is called. This method creates a new execution context and establishes a link between the new execution context and the lexical environment of the function-object. It does this by copying the [[Environment]] value on the function-object, into an outer reference field on the lexical environment of the new execution context.

Note that this link between the new execution context and the lexical environment of the function object is called a closure.

Thus, in JavaScript, scope is implemented via lexical environments linked together in a "chain" by outer references. This chain of lexical environments is called the scope chain, and identifier resolution occurs by searching up the chain for a matching identifier.

Find out more.

Is there a way to instantiate a class by name in Java?

use Class.forName("String name of class").newInstance();

Class.forName("A").newInstance();

This will cause class named A initialized.

Command output redirect to file and terminal

It is worth mentioning that 2>&1 means that standard error will be redirected too, together with standard output. So

someCommand | tee someFile

gives you just the standard output in the file, but not the standard error: standard error will appear in console only. To get standard error in the file too, you can use

someCommand 2>&1 | tee someFile

(source: In the shell, what is " 2>&1 "? ). Finally, both the above commands will truncate the file and start clear. If you use a sequence of commands, you may want to get output&error of all of them, one after another. In this case you can use -a flag to "tee" command:

someCommand 2>&1 | tee -a someFile

How do I pre-populate a jQuery Datepicker textbox with today's date?

To pre-populate date, first you have to initialise datepicker, then pass setDate parameter value.

$("#date_pretty").datepicker().datepicker("setDate", new Date());

Getting realtime output using subprocess

Depending on the use case, you might also want to disable the buffering in the subprocess itself.

If the subprocess will be a Python process, you could do this before the call:

os.environ["PYTHONUNBUFFERED"] = "1"

Or alternatively pass this in the env argument to Popen.

Otherwise, if you are on Linux/Unix, you can use the stdbuf tool. E.g. like:

cmd = ["stdbuf", "-oL"] + cmd

See also here about stdbuf or other options.

(See also here for the same answer.)

Is init.py not required for packages in Python 3.3+

Based on my experience, even with python 3.3+, an empty __init__.py is still needed sometimes. One situation is when you want to refer a subfolder as a package. For example, when I ran python -m test.foo, it didn't work until I created an empty __init__.py under the test folder. And I'm talking about 3.6.6 version here which is pretty recent.

Apart from that, even for reasons of compatibility with existing source code or project guidelines, its nice to have an empty __init__.py in your package folder.

Checking Date format from a string in C#

string inputString = "2000-02-02";
DateTime dDate;

if (DateTime.TryParse(inputString, out dDate))
{
    String.Format("{0:d/MM/yyyy}", dDate); 
}
else
{
    Console.WriteLine("Invalid"); // <-- Control flow goes here
}

How to make parent wait for all child processes to finish?

POSIX defines a function: wait(NULL);. It's the shorthand for waitpid(-1, NULL, 0);, which will suspends the execution of the calling process until any one child process exits. Here, 1st argument of waitpid indicates wait for any child process to end.

In your case, have the parent call it from within your else branch.

How to install a PHP IDE plugin for Eclipse directly from the Eclipse environment?

The URL which worked for me is http://download.eclipse.org/tools/pdt/updates/2.0/interim/.

See also Stack Overflow question Installing PDT in Eclipse - No runtime option .. only SDK.

Vue js error: Component template should contain exactly one root element

if, for any reasons, you don't want to add a wrapper (in my first case it was for <tr/> components), you can use a functionnal component.

Instead of having a single components/MyCompo.vue you will have few files in a components/MyCompo folder :

components/MyCompo/index.js
components/MyCompo/File.vue
components/MyCompo/Avatar.vue

With this structure, the way you call your component won't change.

components/MyCompo/index.js file content :

import File from './File';
import Avatar from './Avatar';   

const commonSort=(a,b)=>b-a;

export default {
  functional: true,
  name: 'MyCompo',
  props: [ 'someProp', 'plopProp' ],
  render(createElement, context) {
    return [
        createElement( File, { props: Object.assign({light: true, sort: commonSort},context.props) } ),
        createElement( Avatar, { props: Object.assign({light: false, sort: commonSort},context.props) } )
    ]; 
  }
};

And if you have some function or data used in both templates, passed them as properties and that's it !

I let you imagine building list of components and so much features with this pattern.

SQL Insert Multiple Rows

Wrap each row of values to be inserted in brackets/parenthesis (value1, value2, value3) and separate the brackets/parenthesis by comma for as many as you wish to insert into the table.

INSERT INTO example
VALUES
  (100, 'Name 1', 'Value 1', 'Other 1'),
  (101, 'Name 2', 'Value 2', 'Other 2'),
  (102, 'Name 3', 'Value 3', 'Other 3'),
  (103, 'Name 4', 'Value 4', 'Other 4');

Create zip file and ignore directory structure

You can use -j.

-j
--junk-paths
          Store just the name of a saved file (junk the path), and do  not
          store  directory names. By default, zip will store the full path
          (relative to the current directory).

URL for public Amazon S3 bucket

The URL structure you're referring to is called the REST endpoint, as opposed to the Web Site Endpoint.

Note: Since this answer was originally written, S3 has rolled out dualstack support on REST endpoints, using new hostnames, while leaving the existing hostnames in place. This is now integrated into the information provided, below.

If your bucket is really in the us-east-1 region of AWS -- which the S3 documentation formerly referred to as the "US Standard" region, but was subsequently officially renamed to the "U.S. East (N. Virginia) Region" -- then http://s3-us-east-1.amazonaws.com/bucket/ is not the correct form for that endpoint, even though it looks like it should be. The correct format for that region is either http://s3.amazonaws.com/bucket/ or http://s3-external-1.amazonaws.com/bucket/.¹

The format you're using is applicable to all the other S3 regions, but not ~~US Standard~~ US East (N. Virginia) [us-east-1].

S3 now also has dual-stack endpoint hostnames for the REST endpoints, and unlike the original endpoint hostnames, the names of these have a consistent format across regions, for example s3.dualstack.us-east-1.amazonaws.com. These endpoints support both IPv4 and IPv6 connectivity and DNS resolution, but are otherwise functionally equivalent to the existing REST endpoints.

If your permissions and configuration are set up such that the web site endpoint works, then the REST endpoint should work, too.

However... the two endpoints do not offer the same functionality.

Roughly speaking, the REST endpoint is better-suited for machine access and the web site endpoint is better suited for human access, since the web site endpoint offers friendly error messages, index documents, and redirects, while the REST endpoint doesn't. On the other hand, the REST endpoint offers HTTPS and support for signed URLs, while the web site endpoint doesn't.

Choose the correct type of endpoint (REST or web site) for your application:

http://docs.aws.amazon.com/AmazonS3/latest/dev/WebsiteEndpoints.html#WebsiteRestEndpointDiff

¹ s3-external-1.amazonaws.com has been referred to as the "Northern Virginia endpoint," in contrast to the "Global endpoint" s3.amazonaws.com. It was unofficially possible to get read-after-write consistency on new objects in this region if the "s3-external-1" hostname was used, because this would send you to a subset of possible physical endpoints that could provide that functionality. This behavior is now officially supported on this endpoint, so this is probably the better choice in many applications. Previously, s3-external-2 had been referred to as the "Pacific Northwest endpoint" for US-Standard, though it is now a CNAME in DNS for s3-external-1 so s3-external-2 appears to have no purpose except backwards-compatibility.

Plot a legend outside of the plotting area in base graphics?

No one has mentioned using negative inset values for legend. Here is an example, where the legend is to the right of the plot, aligned to the top (using keyword "topright").

# Random data to plot:
A <- data.frame(x=rnorm(100, 20, 2), y=rnorm(100, 20, 2))
B <- data.frame(x=rnorm(100, 21, 1), y=rnorm(100, 21, 1))

# Add extra space to right of plot area; change clipping to figure
par(mar=c(5.1, 4.1, 4.1, 8.1), xpd=TRUE)

# Plot both groups
plot(y ~ x, A, ylim=range(c(A$y, B$y)), xlim=range(c(A$x, B$x)), pch=1,
               main="Scatter plot of two groups")
points(y ~ x, B, pch=3)

# Add legend to top right, outside plot region
legend("topright", inset=c(-0.2,0), legend=c("A","B"), pch=c(1,3), title="Group")

The first value of inset=c(-0.2,0) might need adjusting based on the width of the legend.

legend_right

What is the difference between a function expression vs declaration in JavaScript?

Though the complete difference is more complicated, the only difference that concerns me is when the machine creates the function object. Which in the case of declarations is before any statement is executed but after a statement body is invoked (be that the global code body or a sub-function's), and in the case of expressions is when the statement it is in gets executed. Other than that for all intents and purposes browsers treat them the same.

To help you understand, take a look at this performance test which busted an assumption I had made of internally declared functions not needing to be re-created by the machine when the outer function is invoked. Kind of a shame too as I liked writing code that way.

Python WindowsError: [Error 123] The filename, directory name, or volume label syntax is incorrect:

I had this problem with Django and it was because I had forgotten to start the virtual environment on the backend.

form_for with nested resources

Be sure to have both objects created in controller: @post and @comment for the post, eg:

@post = Post.find params[:post_id]
@comment = Comment.new(:post=>@post)

Then in view:

<%= form_for([@post, @comment]) do |f| %>

Be sure to explicitly define the array in the form_for, not just comma separated like you have above.

'namespace' but is used like a 'type'

I had this problem as I created a class "Response.cs" inside a folder named "Response". So VS was catching the new Response () as Folder/namespace.

So I changed the class name to StatusResponse.cs and called new StatusResponse().This solved the issue.

How to Get a Specific Column Value from a DataTable?

string countryName = "USA";
DataTable dt = new DataTable();
int id = (from DataRow dr in dt.Rows
              where (string)dr["CountryName"] == countryName
              select (int)dr["id"]).FirstOrDefault();

Python loop to run for certain amount of seconds

I was looking for an easier-to-read time-loop when I encountered this question here. Something like:

for sec in max_seconds(10):
      do_something()

So I created this helper:

# allow easy time-boxing: 'for sec in max_seconds(42): do_something()'
def max_seconds(max_seconds, *, interval=1):
    interval = int(interval)
    start_time = time.time()
    end_time = start_time + max_seconds
    yield 0
    while time.time() < end_time:
        if interval > 0:
            next_time = start_time
            while next_time < time.time():
                next_time += interval
            time.sleep(int(round(next_time - time.time())))
        yield int(round(time.time() - start_time))
        if int(round(time.time() + interval)) > int(round(end_time)): 
            return

It only works with full seconds which was OK for my use-case.

Examples:

for sec in max_seconds(10) # -> 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
for sec in max_seconds(10, interval=3) # -> 0, 3, 6, 9
for sec in max_seconds(7): sleep(1.5) # -> 0, 2, 4, 6
for sec in max_seconds(8): sleep(1.5) # -> 0, 2, 4, 6, 8

Be aware that interval isn't that accurate, as I only wait full seconds (sleep never was any good for me with times < 1 sec). So if your job takes 500 ms and you ask for an interval of 1 sec, you'll get called at: 0, 500ms, 2000ms, 2500ms, 4000ms and so on. One could fix this by measuring time in a loop rather than sleep() ...

How to run a javascript function during a mouseover on a div

I'm assuming you want to display the welcome when you mouse over "some text".

As a message box, this will be:

<div id="sub1" onmouseover="javascript:alert('Welcome!');">some text</div>

As a tooltip, it should be:

<div id="sub1" title="Welcome!">some text</div>

As a new div, you can use:

<div id="sub1" onmouseover="javascript:var mydiv = document.createElement('div'); mydiv.height = 100; mydiv.width = 100; mydiv.zindex = 1000; mydiv.innerHTML = 'Welcome!'; mydiv.position = 'absolute'; mydiv.top = 0; mydiv.left = 0;">some text</div>

You should NEVER contain spaces in the id of an element.

What is best way to start and stop hadoop ecosystem, with command line?

Starting

start-dfs.sh (starts the namenode and the datanode)
start-mapred.sh (starts the jobtracker and the tasktracker)

Stopping

stop-dfs.sh
stop-mapred.sh

Dictionaries and default values

How to convert milliseconds into a readable date?

You can use datejs and convert in different formate. I have tested some formate and working fine.

var d = new Date(1469433907836);

d.toLocaleString()     // 7/25/2016, 1:35:07 PM
d.toLocaleDateString() // 7/25/2016
d.toDateString()       // Mon Jul 25 2016
d.toTimeString()       // 13:35:07 GMT+0530 (India Standard Time)
d.toLocaleTimeString() // 1:35:07 PM
d.toISOString();       // 2016-07-25T08:05:07.836Z
d.toJSON();            // 2016-07-25T08:05:07.836Z
d.toString();          // Mon Jul 25 2016 13:35:07 GMT+0530 (India Standard Time)
d.toUTCString();       // Mon, 25 Jul 2016 08:05:07 GMT

What's the most efficient way to erase duplicates and sort a vector?

Assuming that a is a vector, remove the contiguous duplicates using

a.erase(unique(a.begin(),a.end()),a.end()); runs in O(n) time.

How to check if a process is in hang state (Linux)

Unfortunately there is no hung state for a process. Now hung can be deadlock. This is block state. The threads in the process are blocked. The other things could be live lock where the process is running but doing the same thing again and again. This process is in running state. So as you can see there is no definite hung state. As suggested you can use the top command to see if the process is using 100% CPU or lot of memory.

WinSCP: Permission denied. Error code: 3 Error message from server: Permission denied

You possibly do not have create permissions to the folder. So WinSCP fails to create a temporary file for the transfer.

You have two options:

Grant write permissions to the folder to the user or group you log in with (myuser), or change the ownership of the folder to the user, or
Disable a transfer to temporary file.

In Preferences, go to Transfer > Endurance page and in Enable transfer resume/transfer to temporary file name for select Disable:

How to use _CRT_SECURE_NO_WARNINGS

Add by

Configuration Properties>>C/C++>>Preporocessor>>Preprocessor Definitions>> _CRT_SECURE_NO_WARNINGS

screenshot of the relevant config interface

C++ -- expected primary-expression before ' '

You should not be repeating the string part when sending parameters.

int wordLength = wordLengthFunction(word); //you do not put string word here.

Disable browser's back button

I was searching for the same question and I found following code on a site. Thought to share it here:

function noBack()
{
   window.history.forward()
}
noBack();
window.onload = noBack;
window.onpageshow = function(evt){ if(evt.persisted) noBack(); }
window.onunload = function(){ void(0); }

However as noted by above users, this is never a good practice and should be avoided for all reasons.

Convert a JSON string to object in Java ME?

I used a few of them and my favorite is,

http://code.google.com/p/json-simple/

The library is very small so it's perfect for J2ME.

You can parse JSON into Java object in one line like this,

JSONObject json = (JSONObject)new JSONParser().parse("{\"name\":\"MyNode\", \"width\":200, \"height\":100}");
System.out.println("name=" + json.get("name"));
System.out.println("width=" + json.get("width"));

How, in general, does Node.js handle 10,000 concurrent requests?

Adding to slebetman answer: When you say Node.JS can handle 10,000 concurrent requests they are essentially non-blocking requests i.e. these requests are majorly pertaining to database query.

Internally, event loop of Node.JS is handling a thread pool, where each thread handles a non-blocking request and event loop continues to listen to more request after delegating work to one of the thread of the thread pool. When one of the thread completes the work, it send a signal to the event loop that it has finished aka callback. Event loop then process this callback and send the response back.

As you are new to NodeJS, do read more about nextTick to understand how event loop works internally. Read blogs on http://javascriptissexy.com, they were really helpful for me when I started with JavaScript/NodeJS.

How do I add more members to my ENUM-type column in MySQL?

FYI: A useful simulation tool - phpMyAdmin with Wampserver 3.0.6 - Preview SQL: I use 'Preview SQL' to see the SQL code that would be generated before you save the column with the change to ENUM. Preview SQL

Above you see that I have entered 'Ford','Toyota' into the ENUM but I am getting syntax ENUM(0) which is generating syntax error Query error 1064#

I then copy and paste and alter the SQL and run it through SQL with a positive result.

SQL changed

This is a quickfix that I use often and can also be used on existing ENUM values that need to be altered. Thought this might be useful.

Arduino COM port doesn't work

Installing Drivers for Arduino in Windows 8 / 7.

( I tried it for Uno r3, but i believe it will work for all Arduino Boards )

Plugin your Arduino Board

Go to Control Panel ---> System and Security ---> System ---> On the left pane Device Manger

Expand Other Devices.

Under Other Devices you will notice a icon with a small yellow error graphic. (Unplug all your other devices attached to any Serial Port)

Right Click on that device ---> Update Driver Software

Select Browse my computer for Driver Software

Click on Browse ---> Browse for the folder of Arduino Environment which you have downloaded from Arduino website. If not downloaded then http://arduino.cc/en/Main/Software

After Browsing mark include subfolder.

Click next ---> Your driver will be installed.

Collapse Other Devices ---> Expand Port ( its in device manager only under other devices )

You will see Arduino Written ---> Look for its COM PORT (close device manager)

Go to Arduino Environment ---> Tools ---> Serial Port ---> Select the COM PORT as mentioned in PORT in device manager. (If you are using any other Arduino Board instead of UNO then select the same in boards )

Upload your killer programmes and see them work . . .

I hope this helps. . .

Welcome

contenteditable change events

Two options:

1) For modern (evergreen) browsers: The "input" event would act as an alternative "change" event.

https://developer.mozilla.org/en-US/docs/Web/Events/input

document.querySelector('div').addEventListener('input', (e) => {
    // Do something with the "change"-like event
});

<div oninput="someFunc(event)"></div>

or (with jQuery)

$('div').on('click', function(e) {
    // Do something with the "change"-like event
});

2) To account for IE11 and modern (evergreen) browsers: This watches for element changes and their contents inside the div.

https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver

var div = document.querySelector('div');
var divMO = new window.MutationObserver(function(e) {
    // Do something on change
});
divMO.observe(div, { childList: true, subtree: true, characterData: true });

How to save a list as numpy array in python?

Here is a more complete example:

import csv
import numpy as np

with open('filename','rb') as csvfile:
     cdl = list( csv.reader(csvfile,delimiter='\t'))
     print "Number of records = " + str(len(cdl))

#then later

npcdl = np.array(cdl)

Hope this helps!!

check if variable is dataframe

Use isinstance, nothing else:

if isinstance(x, pd.DataFrame):
    ... # do something

PEP8 says explicitly that isinstance is the preferred way to check types

No:  type(x) is pd.DataFrame
No:  type(x) == pd.DataFrame
Yes: isinstance(x, pd.DataFrame)

And don't even think about

if obj.__class__.__name__ = 'DataFrame':
    expect_problems_some_day()

isinstance handles inheritance (see What are the differences between type() and isinstance()?). For example, it will tell you if a variable is a string (either str or unicode), because they derive from basestring)

if isinstance(obj, basestring):
    i_am_string(obj)

Specifically for pandas DataFrame objects:

import pandas as pd
isinstance(var, pd.DataFrame)

How to make my font bold using css?

You can use the CSS declaration font-weight: bold;.

I would advise you to read the CSS beginner guide at http://htmldog.com/guides/cssbeginner/ .

Laravel 5 - redirect to HTTPS

For Laravel 5.6, I had to change condition a little to make it work.

from:

if (!$request->secure() && env('APP_ENV') === 'prod') {
return redirect()->secure($request->getRequestUri());
}

To:

if (empty($_SERVER['HTTPS']) && env('APP_ENV') === 'prod') {
return redirect()->secure($request->getRequestUri());
}

C: socket connection timeout

The two socket options SO_RCVTIMEO and SO_SNDTIMEO have no effect on connect. Below is a link to the screenshot which includes this explanation, here I am just briefing it. The apt way of implementing timeouts with connect are using signal or select or poll.

Signals

connect can be interrupted by a self generated signal SIGALRM by using syscall (wrapper) alarm. But, a signal disposition should be installed for the same signal otherwise the program would be terminated. The code goes like this...

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<signal.h>
#include<errno.h>

static void signal_handler(int signo)
{
    return; // Do nothing just interrupt.
}

int main()
{
    /* Register signal handler */

    struct sigaction act, oact;

    act.sa_handler = signal_handler;
    sigemptyset(&act.sa_mask);
    act.sa_flags = 0;

#ifdef SA_INTERRUPT
    act.sa_flags |= SA_INTERRUPT;
#endif

    if(sigaction(SIGALRM, &act, &oact) < 0)  // Error registering signal handler.
    {
        fprintf(stderr, "Error registering signal disposition\n");
        exit(1);
    }

    /* Prepare your socket and sockaddr structures */

    int sockfd;
    struct sockaddr* servaddr;

    /* Implementing timeout connect */

    int sec = 30;

    if(alarm(sec) != 0)
        fprintf(stderr, "Already timer was set\n");

    if(connect(sockfd, servaddr, sizeof(struct sockaddr)) < 0)
    {
        if(errno == EINTR)
            fprintf(stderr, "Connect timeout\n");
        else
            fprintf(stderr, "Connect failed\n");

        close(sockfd);

        exit(1);
    }

    alarm(0);  /* turn off the alarm */

    sigaction(SIGALRM, &oact, NULL);  /* Restore the default actions of SIGALRM */

    /* Use socket */


    /* End program */

    close(sockfd);
    return 0;
}

Select or Poll

As already some users provided nice explanation on how to use select to achieve connect timeout, it would not be necessary for me to reiterate the same. poll can be used in the same way. However, there are few mistakes that are common in all of the answers, which I would like to address.

Even though socket is non-blocking, if the server to which we are connecting is on the same local machine, connect may return with success. So it is advised to check the return value of connect before calling select.
Berkeley-derived implementations (and POSIX) have the following rules for non-blocking sockets and connect.

1) When the connection completes successfully, the descriptor becomes writable (p. 531 of TCPv2).

2) When the connection establishment encounters an error, the descriptor becomes both readable and writable (p. 530 of TCPv2).

So the code should handle these cases, here I just code the necessary modifications.

/* All the code stays */

/* Modifications at connect */

int conn_ret = connect(sockfd, servaddr, sizeof(struct sockdaddr));

if(conn_ret == 0)
    goto done;

/* Modifications at select */

int sec = 30;
for( ; ; )
{
    struct timeval timeo;
    timeo.tv_sec = sec;
    timeo.tv_usec = 0;

    fd_set wr_set, rd_set;
    FDZERO(&wr_set);
    FD_SET(sockfd, &wr_set);
    rd_set = wr_set;
    int sl_ret = select(sockfd + 1, &rd_set, &wr_set, NULL, &timeo);

    /* All the code stays */
}


done:

    /* Use your socket */

Text from Unix Network Programming Volume 1

JavaScript - XMLHttpRequest, Access-Control-Allow-Origin errors

I've gotten same problem. The servers logs showed:

DEBUG: <-- origin: null

I've investigated that and it occurred that this is not populated when I've been calling from file from local drive. When I've copied file to the server and used it from server - the request worked perfectly fine

How exactly do you configure httpOnlyCookies in ASP.NET?

If you want to do it in code, use the System.Web.HttpCookie.HttpOnly property.

This is directly from the MSDN docs:

// Create a new HttpCookie.
HttpCookie myHttpCookie = new HttpCookie("LastVisit", DateTime.Now.ToString());
// By default, the HttpOnly property is set to false 
// unless specified otherwise in configuration.
myHttpCookie.Name = "MyHttpCookie";
Response.AppendCookie(myHttpCookie);
// Show the name of the cookie.
Response.Write(myHttpCookie.Name);
// Create an HttpOnly cookie.
HttpCookie myHttpOnlyCookie = new HttpCookie("LastVisit", DateTime.Now.ToString());
// Setting the HttpOnly value to true, makes
// this cookie accessible only to ASP.NET.
myHttpOnlyCookie.HttpOnly = true;
myHttpOnlyCookie.Name = "MyHttpOnlyCookie";
Response.AppendCookie(myHttpOnlyCookie);
// Show the name of the HttpOnly cookie.
Response.Write(myHttpOnlyCookie.Name);

Doing it in code allows you to selectively choose which cookies are HttpOnly and which are not.

Making Enter key on an HTML form submit instead of activating button

You don't need JavaScript to choose your default submit button or input. You just need to mark it up with type="submit", and the other buttons mark them with type="button". In your example:

<button type="button" onclick="return myFunc1()">Button 1</button>
<input type="submit" name="go" value="Submit"/>

A python class that acts like dict

Don’t inherit from Python built-in dict, ever! for example update method woldn't use __setitem__, they do a lot for optimization. Use UserDict.

from collections import UserDict

class MyDict(UserDict):
    def __delitem__(self, key):
        pass
    def __setitem__(self, key, value):
        pass

Returning Month Name in SQL Server Query

basically this ...

declare @currentdate datetime = getdate()
select left(datename(month,DATEADD(MONTH, -1, GETDATE())),3)
union all
select left(datename(month,(DATEADD(MONTH, -2, GETDATE()))),3)
union all
select left(datename(month,(DATEADD(MONTH, -3, GETDATE()))),3)

What does the "yield" keyword do?

Here is a mental image of what yield does.

I like to think of a thread as having a stack (even when it's not implemented that way).

When a normal function is called, it puts its local variables on the stack, does some computation, then clears the stack and returns. The values of its local variables are never seen again.

With a yield function, when its code begins to run (i.e. after the function is called, returning a generator object, whose next() method is then invoked), it similarly puts its local variables onto the stack and computes for a while. But then, when it hits the yield statement, before clearing its part of the stack and returning, it takes a snapshot of its local variables and stores them in the generator object. It also writes down the place where it's currently up to in its code (i.e. the particular yield statement).

So it's a kind of a frozen function that the generator is hanging onto.

When next() is called subsequently, it retrieves the function's belongings onto the stack and re-animates it. The function continues to compute from where it left off, oblivious to the fact that it had just spent an eternity in cold storage.

Compare the following examples:

def normalFunction():
    return
    if False:
        pass

def yielderFunction():
    return
    if False:
        yield 12

When we call the second function, it behaves very differently to the first. The yield statement might be unreachable, but if it's present anywhere, it changes the nature of what we're dealing with.

>>> yielderFunction()
<generator object yielderFunction at 0x07742D28>

Calling yielderFunction() doesn't run its code, but makes a generator out of the code. (Maybe it's a good idea to name such things with the yielder prefix for readability.)

>>> gen = yielderFunction()
>>> dir(gen)
['__class__',
 ...
 '__iter__',    #Returns gen itself, to make it work uniformly with containers
 ...            #when given to a for loop. (Containers return an iterator instead.)
 'close',
 'gi_code',
 'gi_frame',
 'gi_running',
 'next',        #The method that runs the function's body.
 'send',
 'throw']

The gi_code and gi_frame fields are where the frozen state is stored. Exploring them with dir(..), we can confirm that our mental model above is credible.

/usr/bin/codesign failed with exit code 1

Same issue with ambiguous (matches "iPhone Developer: [me] " and /// tweetdeck's library privatedata file. Fixed it by moving file to the trash and re-logging into Tweetdeck, setting up passwords again. What a pain.

php var_dump() vs print_r()

var_dump displays structured information about the object / variable. This includes type and values. Like print_r arrays are recursed through and indented.

print_r displays human readable information about the values with a format presenting keys and elements for arrays and objects.

The most important thing to notice is var_dump will output type as well as values while print_r does not.

Cleaning `Inf` values from an R dataframe

Feng Mai has a tidyverse answer above to get negative and positive infinities:

dat %>% mutate_if(is.numeric, list(~na_if(., Inf))) %>% 
  mutate_if(is.numeric, list(~na_if(., -Inf)))

This works well, but a word of warning is not to swap in abs(.) here to do both lines at once as is proposed in an upvoted comment. It will look like it works, but changes all negative values in the dataset to positive! You can confirm with this:

data(iris)
#The last line here is bad - it converts all negative values to positive
iris %>% 
  mutate_if(is.numeric, ~scale(.)) %>%
  mutate(infinities = Sepal.Length / 0) %>%
  mutate_if(is.numeric, list(~na_if(abs(.), Inf)))

For one line, this works:

  mutate_if(is.numeric, ~ifelse(abs(.) == Inf,NA,.))

I get exception when using Thread.sleep(x) or wait()

Alternatively, if you don't want to deal with threads, try this method:

public static void pause(int seconds){
    Date start = new Date();
    Date end = new Date();
    while(end.getTime() - start.getTime() < seconds * 1000){
        end = new Date();
    }
}

It starts when you call it, and ends when the number of seconds have passed.

OpenCV - Saving images to a particular folder of choice

The solution provided by ebeneditos works perfectly.

But if you have cv2.imwrite() in several sections of a large code snippet and you want to change the path where the images get saved, you will have to change the path at every occurrence of cv2.imwrite() individually.

As Soltius stated, here is a better way. Declare a path and pass it as a string into cv2.imwrite()

import cv2
import os
img = cv2.imread('1.jpg', 1)
path = 'D:/OpenCV/Scripts/Images'
cv2.imwrite(os.path.join(path , 'waka.jpg'), img)
cv2.waitKey(0)

Now if you want to modify the path, you just have to change the path variable.

Edited based on solution provided by Kallz

Error : No resource found that matches the given name (at 'icon' with value '@drawable/icon')

If you are 100% sure that directories and files are ok, have a look at the project location.

There is a limit on the path length of files in the Operating System. Perhaps this limit is being exceded in your project files.

Move the project to a shorter folder (say C:/MyProject) and try again!

This was the problem for me!

iPhone SDK on Windows (alternative solutions)

No one has brought up the hackintosh. If you have supported hardware it might be the best option.

Replace multiple whitespaces with single whitespace in JavaScript string

If you want to restrict user to give blank space in the name just create a if statement and give the condition. like I did:

$j('#fragment_key').bind({
    keypress: function(e){
        var key = e.keyCode;
    var character = String.fromCharCode(key); 
    if(character.match( /[' ']/)) {
        alert("Blank space is not allowed in the Name");
        return false;
        }
    }
});

create a JQuery function .
this is key press event.
Initialize a variable.
Give condition to match the character
show a alert message for your matched condition.

How to create an Explorer-like folder browser control?

Take a look at Shell MegaPack control set. It provides Windows Explorer like folder/file browsing with most of the features and functionality like context menus, renaming, drag-drop, icons, overlay icons, thumbnails, etc

.map() a Javascript ES6 Map?

Using Array.from I wrote a Typescript function that maps the values:

function mapKeys<T, V, U>(m: Map<T, V>, fn: (this: void, v: V) => U): Map<T, U> {
  function transformPair([k, v]: [T, V]): [T, U] {
    return [k, fn(v)]
  }
  return new Map(Array.from(m.entries(), transformPair));
}

const m = new Map([[1, 2], [3, 4]]);
console.log(mapKeys(m, i => i + 1));
// Map { 1 => 3, 3 => 5 }

Why does cURL return error "(23) Failed writing body"?

In Bash and zsh (and perhaps other shells), you can use process substitution (Bash/zsh) to create a file on the fly, and then use that as input to the next process in the pipeline chain.

For example, I was trying to parse JSON output from cURL using jq and less, but was getting the Failed writing body error.

# Note: this does NOT work
curl https://gitlab.com/api/v4/projects/ | jq | less

When I rewrote it using process substitution, it worked!

# this works!
jq "" <(curl https://gitlab.com/api/v4/projects/) | less

Note: jq uses its 2nd argument to specify an input file

Bonus: If you're using jq like me and want to keep the colorized output in less, use the following command line instead:

jq -C "" <(curl https://gitlab.com/api/v4/projects/) | less -r

(Thanks to Kowaru for their explanation of why Failed writing body was occurring. However, their solution of using tac twice didn't work for me. I also wanted to find a solution that would scale better for large files and tries to avoid the other issues noted as comments to that answer.)

Chmod recursively

Try to change all the persmissions at the same time:

chmod -R +xr

Implementing a simple file download servlet

Assuming you have access to servlet as below

http://localhost:8080/myapp/download?id=7

I need to create a servlet and register it to web.xml

web.xml

<servlet>
     <servlet-name>DownloadServlet</servlet-name>
     <servlet-class>com.myapp.servlet.DownloadServlet</servlet-class>
</servlet>
<servlet-mapping>
     <servlet-name>DownloadServlet</servlet-name>
     <url-pattern>/download</url-pattern>
</servlet-mapping>

DownloadServlet.java

public class DownloadServlet extends HttpServlet {


    protected void doGet( HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

         String id = request.getParameter("id");

         String fileName = "";
         String fileType = "";
         // Find this file id in database to get file name, and file type

         // You must tell the browser the file type you are going to send
         // for example application/pdf, text/plain, text/html, image/jpg
         response.setContentType(fileType);

         // Make sure to show the download dialog
         response.setHeader("Content-disposition","attachment; filename=yourcustomfilename.pdf");

         // Assume file name is retrieved from database
         // For example D:\\file\\test.pdf

         File my_file = new File(fileName);

         // This should send the file to browser
         OutputStream out = response.getOutputStream();
         FileInputStream in = new FileInputStream(my_file);
         byte[] buffer = new byte[4096];
         int length;
         while ((length = in.read(buffer)) > 0){
            out.write(buffer, 0, length);
         }
         in.close();
         out.flush();
    }
}

Why do we always prefer using parameters in SQL statements?

In addition to other answers need to add that parameters not only helps prevent sql injection but can improve performance of queries. Sql server caching parameterized query plans and reuse them on repeated queries execution. If you not parameterized your query then sql server would compile new plan on each query(with some exclusion) execution if text of query would differ.

More information about query plan caching

TypeError: not all arguments converted during string formatting python

I encounter the error as well,

_mysql_exceptions.ProgrammingError: not all arguments converted during string formatting

But list args work well.

I use mysqlclient python lib. The lib looks like not to accept tuple args. To pass list args like ['arg1', 'arg2'] will work.

Positioning the colorbar

The best way to get good control over the colorbar position is to give it its own axis. Like so:

# What I imagine your plotting looks like so far
fig = plt.figure()
ax1 = fig.add_subplot(111)
ax1.plot(your_data)

# Now adding the colorbar
cbaxes = fig.add_axes([0.8, 0.1, 0.03, 0.8]) 
cb = plt.colorbar(ax1, cax = cbaxes)

The numbers in the square brackets of add_axes refer to [left, bottom, width, height], where the coordinates are just fractions that go from 0 to 1 of the plotting area.

Apache SSL Configuration Error (SSL Connection Error)

It turns out that the SSL certificate was installed improperly. Re-installing it properly fixed the problem

how to create Socket connection in Android?

Socket connections in Android are the same as in Java: http://www.oracle.com/technetwork/java/socket-140484.html

Things you need to be aware of:

If phone goes to sleep your app will no longer execute, so socket will eventually timeout. You can prevent this with wake lock. This will eat devices battery tremendously - I know I wouldn't use that app.
If you do this constantly, even when your app is not active, then you need to use Service.
Activities and Services can be killed off by OS at any time, especially if they are part of an inactive app.

Take a look at AlarmManager, if you need scheduled execution of your code.

Do you need to run your code and receive data even if user does not use the app any more (i.e. app is inactive)?

Bootstrap collapse animation not smooth

Adding to @CR Rollyson answer,

In case if you have a collapsible div which has a min-height attribute, it will also cause the jerking. Try removing that attribute from directly collapsible div. Use it in the child div of the collapsible div.

<div class="form-group">
    <a for="collapseOne" data-toggle="collapse" href="#collapseOne" aria-expanded="true" aria-controls="collapseOne">+ Not Jerky</a>
    <div class="collapse" id="collapseOne" style="padding: 0;">
        <textarea class="form-control" rows="4" style="padding: 20px;">No padding on animated element. Padding on child.</textarea>
    </div>
</div>

Fiddle

JSR 303 Validation, If one field equals "something", then these other fields should not be null

jQuery: Best practice to populate drop down?

$.getJSON("/Admin/GetFolderList/", function(result) {
    var options = $("#options");
    //don't forget error handling!
    $.each(result, function(item) {
        options.append($("<option />").val(item.ImageFolderID).text(item.Name));
    });
});

What I'm doing above is creating a new <option> element and adding it to the options list (assuming options is the ID of a drop down element.

PS My javascript is a bit rusty so the syntax may not be perfect

How to use the start command in a batch file?

I think this other Stack Overflow answer would solve your problem: How do I run a bat file in the background from another bat file?

Basically, you use the /B and /C options:

START /B CMD /C CALL "foo.bat" [args [...]] >NUL 2>&1

The entitlements specified...profile. (0xE8008016). Error iOS 4.2

Deleting the xcuserdata folder solved my issue. More on that here: https://stackoverflow.com/a/9968884/300694

How to make certain text not selectable with CSS

The CSS below stops users from being able to select text.

-webkit-user-select: none; /* Safari */        
-moz-user-select: none; /* Firefox */
-ms-user-select: none; /* IE10+/Edge */
user-select: none; /* Standard */

To target IE9 downwards the html attribute unselectable must be used instead:

<p unselectable="on">Test Text</p>

How to add a custom Ribbon tab using VBA?

AFAIK you cannot use VBA Excel to create custom tab in the Excel ribbon. You can however hide/make visible a ribbon component using VBA. Additionally, the link that you mentioned above is for MS Project and not MS Excel.

I create tabs for my Excel Applications/Add-Ins using this free utility called Custom UI Editor.

Edit: To accommodate new request by OP

Tutorial

Here is a short tutorial as promised:

After you have installed the Custom UI Editor (CUIE), open it and then click on File | Open and select the relevant Excel File. Please ensure that the Excel File is closed before you open it via CUIE. I am using a brand new worksheet as an example.
Right click as shown in the image below and click on "Office 2007 Custom UI Part". It will insert the "customUI.xml"
Next Click on menu Insert | Sample XML | Custom Tab. You will notice that the basic code is automatically generated. Now you are all set to edit it as per your requirements.
Let's inspect the code

label="Custom Tab": Replace "Custom Tab" with the name which you want to give your tab. For the time being let's call it "Jerome".

The below part adds a custom button.
```
<button id="customButton" label="Custom Button" imageMso="HappyFace" size="large" onAction="Callback" />
```
imageMso: This is the image that will display on the button. "HappyFace" is what you will see at the moment. You can download more image ID's here.

onAction="Callback": "Callback" is the name of the procedure which runs when you click on the button.

Demo

With that, let's create 2 buttons and call them "JG Button 1" and "JG Button 2". Let's keep happy face as the image of the first one and let's keep the "Sun" for the second. The amended code now looks like this:

<customUI xmlns="http://schemas.microsoft.com/office/2006/01/customui">
<ribbon startFromScratch="false">
<tabs>
<tab id="MyCustomTab" label="Jerome" insertAfterMso="TabView">
<group id="customGroup1" label="First Tab">
<button id="customButton1" label="JG Button 1" imageMso="HappyFace" size="large" onAction="Callback1" />
<button id="customButton2" label="JG Button 2" imageMso="PictureBrightnessGallery" size="large" onAction="Callback2" />
</group>
</tab>
</tabs>
</ribbon>
</customUI>

Delete all the code which was generated in CUIE and then paste the above code in lieu of that. Save and close CUIE. Now when you open the Excel File it will look like this:

enter image description here

Now the code part. Open VBA Editor, insert a module, and paste this code:

Public Sub Callback1(control As IRibbonControl)

    MsgBox "You pressed Happy Face"

End Sub

Public Sub Callback2(control As IRibbonControl)

    MsgBox "You pressed the Sun"

End Sub

Save the Excel file as a macro enabled file. Now when you click on the Smiley or the Sun you will see the relevant message box:

enter image description here

Hope this helps!

Adding a JAR to an Eclipse Java library

As of Helios Service Release 2, there is no longer support for JAR files.You can add them, but Eclipse will not recognize them as libraries, therefore you can only "import" but can never use.

MySQL: update a field only if condition is met

found the solution with AND condition:

  $trainstrength = "UPDATE user_character SET strength_trains = strength_trains + 1, trained_strength = trained_strength +1, character_gold = character_gold - $gold_to_next_strength WHERE ID = $currentUser AND character_gold > $gold_to_next_strength";

How can I map True/False to 1/0 in a Pandas DataFrame?

A succinct way to convert a single column of boolean values to a column of integers 1 or 0:

df["somecolumn"] = df["somecolumn"].astype(int)

How to enable named/bind/DNS full logging?

I usually expand each log out into it's own channel and then to a separate log file, certainly makes things easier when you are trying to debug specific issues. So my logging section looks like the following:

logging {
    channel default_file {
        file "/var/log/named/default.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel general_file {
        file "/var/log/named/general.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel database_file {
        file "/var/log/named/database.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel security_file {
        file "/var/log/named/security.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel config_file {
        file "/var/log/named/config.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel resolver_file {
        file "/var/log/named/resolver.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel xfer-in_file {
        file "/var/log/named/xfer-in.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel xfer-out_file {
        file "/var/log/named/xfer-out.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel notify_file {
        file "/var/log/named/notify.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel client_file {
        file "/var/log/named/client.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel unmatched_file {
        file "/var/log/named/unmatched.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel queries_file {
        file "/var/log/named/queries.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel network_file {
        file "/var/log/named/network.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel update_file {
        file "/var/log/named/update.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel dispatch_file {
        file "/var/log/named/dispatch.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel dnssec_file {
        file "/var/log/named/dnssec.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };
    channel lame-servers_file {
        file "/var/log/named/lame-servers.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    };

    category default { default_file; };
    category general { general_file; };
    category database { database_file; };
    category security { security_file; };
    category config { config_file; };
    category resolver { resolver_file; };
    category xfer-in { xfer-in_file; };
    category xfer-out { xfer-out_file; };
    category notify { notify_file; };
    category client { client_file; };
    category unmatched { unmatched_file; };
    category queries { queries_file; };
    category network { network_file; };
    category update { update_file; };
    category dispatch { dispatch_file; };
    category dnssec { dnssec_file; };
    category lame-servers { lame-servers_file; };
};

Hope this helps.

Altering a column to be nullable

This depends on what SQL Engine you are using, in Sybase your command works fine:

ALTER TABLE Merchant_Pending_Functions 
Modify NumberOfLocations NULL;

Select a date from date picker using Selenium webdriver

WebDriver driver;

public void launch(){

    driver = new FirefoxDriver();
    driver.get("http://www.cleartrip.com/");
    driver.manage().window().maximize();
    System.out.println("The browser launched successfully");
    }
public void clickdate(String inputDate){
    WebElement ele =driver.findElement(By.id("DepartDate"));
    ele.click();
    String month = driver.findElement(By.xpath("//div[@class='monthBlock first']/div[1]//span[1]")).getText();
    String year = driver.findElement(By.xpath("//div[@class='monthBlock first']/div[1]//span[2]")).getText();
    System.out.println("Application month : "+month + " Year :"+year);
    int monthNum = getMonthNum(month);
    System.out.println("Enum Num : "+monthNum);
    String[] parts = inputDate.split("/");
    int noOfHits = ((Integer.parseInt(parts[2])-Integer.parseInt(year))*12)+(Integer.parseInt(parts[1])-monthNum);
    System.out.println("No OF Hits "+noOfHits);
    for(int i=0; i< noOfHits;i++){
    driver.findElement(By.className("nextMonth ")).click();
    }
    List<WebElement> cals=driver.findElements(By.xpath("//div[@class='monthBlock first']//tr"));
    System.out.println(cals.size());
    for( WebElement daterow : cals){
    List<WebElement> datenums = daterow.findElements(By.xpath("//td"));
    /*iterating the "td" list*/
    for(WebElement date : datenums ){
    /* Checking The our input Date(if it match go inside and click*/
    if(date.getText().equalsIgnoreCase(parts[0])){
    date.click();
    break;
                          }
                     }
                 }
}

public  int getMonthNum(String month){
    for (Month mName : Month.values()) {
    if(mName.name().equalsIgnoreCase(month))
    return mName.value;
    }
    return -1;
    }

public enum Month{
    January(1), February(2), March(3), April(4), May(5), June(6) , July(7), August(8), September(9), October(10), November(11),December(12);
    private int value;

    private Month(int value) {
    this.value = value;
    }

    }


public static void main(String[] args)  {
    // TODO Auto-generated method stub
    Cleartrip cl=new Cleartrip();
    cl.launch();
    cl.clickdate("24/11/2015");
    }
}

How to move a git repository into another directory and make that directory a git repository?

It's very simple. Git doesn't care about what's the name of its directory. It only cares what's inside. So you can simply do:

# copy the directory into newrepo dir that exists already (else create it)
$ cp -r gitrepo1 newrepo

# remove .git from old repo to delete all history and anything git from it
$ rm -rf gitrepo1/.git

Note that the copy is quite expensive if the repository is large and with a long history. You can avoid it easily too:

# move the directory instead
$ mv gitrepo1 newrepo

# make a copy of the latest version
# Either:
$ mkdir gitrepo1; cp -r newrepo/* gitrepo1/  # doesn't copy .gitignore (and other hidden files)

# Or:
$ git clone --depth 1 newrepo gitrepo1; rm -rf gitrepo1/.git

# Or (look further here: http://stackoverflow.com/q/1209999/912144)
$ git archive --format=tar --remote=<repository URL> HEAD | tar xf -

Once you create newrepo, the destination to put gitrepo1 could be anywhere, even inside newrepo if you want it. It doesn't change the procedure, just the path you are writing gitrepo1 back.

Converting NumPy array into Python List structure?

Use tolist():

import numpy as np
>>> np.array([[1,2,3],[4,5,6]]).tolist()
[[1, 2, 3], [4, 5, 6]]

Note that this converts the values from whatever numpy type they may have (e.g. np.int32 or np.float32) to the "nearest compatible Python type" (in a list). If you want to preserve the numpy data types, you could call list() on your array instead, and you'll end up with a list of numpy scalars. (Thanks to Mr_and_Mrs_D for pointing that out in a comment.)

AttributeError: 'numpy.ndarray' object has no attribute 'append'

Use numpy.concatenate(list1 , list2) or numpy.append() Look into the thread at Append a NumPy array to a NumPy array.

Unexpected 'else' in "else" error

You need to rearrange your curly brackets. Your first statement is complete, so R interprets it as such and produces syntax errors on the other lines. Your code should look like:

if (dsnt<0.05) {
  wilcox.test(distance[result=='nt'],distance[result=='t'],alternative=c("two.sided"),paired=TRUE)
} else if (dst<0.05) {
  wilcox.test(distance[result=='nt'],distance[result=='t'],alternative=c("two.sided"),paired=TRUE)
} else {
  t.test(distance[result=='nt'],distance[result=='t'],alternative=c("two.sided"),paired=TRUE)       
}

To put it more simply, if you have:

if(condition == TRUE) x <- TRUE
else x <- FALSE

Then R reads the first line and because it is complete, runs that in its entirety. When it gets to the next line, it goes "Else? Else what?" because it is a completely new statement. To have R interpret the else as part of the preceding if statement, you must have curly brackets to tell R that you aren't yet finished:

if(condition == TRUE) {x <- TRUE
 } else {x <- FALSE}

Unlocking tables if thread is lost

how will I know that some tables are locked?

You can use SHOW OPEN TABLES command to view locked tables.

how do I unlock tables manually?

If you know the session ID that locked tables - 'SELECT CONNECTION_ID()', then you can run KILL command to terminate session and unlock tables.

How to display a list of images in a ListView in Android?

I'd start with something like this (and if there is something wrong with my code, I'd of course appreciate any comment):

public class ItemsList extends ListActivity {

private ItemsAdapter adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.items_list);

    this.adapter = new ItemsAdapter(this, R.layout.items_list_item, ItemManager.getLoadedItems());
    setListAdapter(this.adapter);
}

private class ItemsAdapter extends ArrayAdapter<Item> {

    private Item[] items;

    public ItemsAdapter(Context context, int textViewResourceId, Item[] items) {
        super(context, textViewResourceId, items);
        this.items = items;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View v = convertView;
        if (v == null) {
            LayoutInflater vi = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            v = vi.inflate(R.layout.items_list_item, null);
        }

        Item it = items[position];
        if (it != null) {
            ImageView iv = (ImageView) v.findViewById(R.id.list_item_image);
            if (iv != null) {
                iv.setImageDrawable(it.getImage());
            }
        }

        return v;
    }
}

@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
    this.adapter.getItem(position).click(this.getApplicationContext());
}
}

E.g. extending ArrayAdapter with own type of Items (holding information about your pictures) and overriden getView() method, that prepares view for items within list. There is also method add() on ArrayAdapter to add items to the end of the list.

R.layout.items_list is simple layout with ListView

R.layout.items_list_item is layout representing one item in list

How to do logging in React Native?

I had the same issue: console messages were not appearing in XCode's debug area. In my app I did cmd-d to bring up the debug menu, and remembered I had set "Debug in Safari" on.

I turned this off, and some messages were printed to the output message, but not my console messages. However, one of the log messages said:

__DEV__ === false, development-level warning are OFF, performance optimizations are ON"

This was because I had previously bundled my project for testing on a real device with the command:

react-native bundle --minify

This bundled without "dev-mode" on. To allow dev messages,include the --dev flag:

react-native bundle --dev

And console.log messages are back! If you aren't bundling for a real device, don't forget to re-point jsCodeLocation in AppDelegate.m to localhost (I did!).

Oracle - What TNS Names file am I using?

Oracle provides a utility called tnsping:

R:\>tnsping someconnection

TNS Ping Utility for 32-bit Windows: Version 9.0.1.3.1 - Production on 27-AUG-20
08 10:38:07

Copyright (c) 1997 Oracle Corporation.  All rights reserved.

Used parameter files:
C:\Oracle92\network\ADMIN\sqlnet.ora
C:\Oracle92\network\ADMIN\tnsnames.ora

TNS-03505: Failed to resolve name

R:\>


R:\>tnsping entpr01

TNS Ping Utility for 32-bit Windows: Version 9.0.1.3.1 - Production on 27-AUG-20
08 10:39:22

Copyright (c) 1997 Oracle Corporation.  All rights reserved.

Used parameter files:
C:\Oracle92\network\ADMIN\sqlnet.ora
C:\Oracle92\network\ADMIN\tnsnames.ora

Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (COMMUNITY = **)
 (PROTOCOL = TCP) (Host = ****) (Port = 1521))) (CONNECT_DATA = (SID = ENTPR0
1)))
OK (40 msec)

R:\>

This should show what file you're using. The utility sits in the Oracle bin directory.

PHP Get name of current directory

getcwd();

dirname(__FILE__);

or (PHP5)

basename(__DIR__)

http://php.net/manual/en/function.getcwd.php

http://php.net/manual/en/function.dirname.php

You can use basename() to get the trailing part of the path :)

In your case, I'd say you are most likely looking to use getcwd(), dirname(__FILE__) is more useful when you have a file that needs to include another library and is included in another library.

Eg:

main.php
libs/common.php
libs/images/editor.php

In your common.php you need to use functions in editor.php, so you use

common.php:

require_once dirname(__FILE__) . '/images/editor.php';

main.php:

require_once libs/common.php

That way when common.php is require'd in main.php, the call of require_once in common.php will correctly includes editor.php in images/editor.php instead of trying to look in current directory where main.php is run.

Return JSON response from Flask view

If you want to analyze a file uploaded by the user, the Flask quickstart shows how to get files from users and access them. Get the file from request.files and pass it to the summary function.

from flask import request, jsonify
from werkzeug import secure_filename

@app.route('/summary', methods=['GET', 'POST'])
def summary():
    if request.method == 'POST':
        csv = request.files['data']
        return jsonify(
            summary=make_summary(csv),
            csv_name=secure_filename(csv.filename)
        )

    return render_template('submit_data.html')

Replace the 'data' key for request.files with the name of the file input in your HTML form.

Video auto play is not working in Safari and Chrome desktop browser

Try this:

    <video height="256" loop autoplay controls id="vid">
     <source type="video/mp4" src="video_file.mp4"></source>
     <source type="video/ogg" src="video_file.ogg"></source>

This is how I normally do it. loop, controls and autoplay do not require a value they are boolean attributes.

Microsoft Visual C++ 14.0 is required (Unable to find vcvarsall.bat)

I had the exact issue while trying to install Scrapy web scraping Python framework on my Windows 10 machine. I figured out the solution this way:

Download the latest (the last one) wheel file from this link wheel file for twisted package
I'd recommend saving that wheel file in the directory where you've installed Python i.e somewhere in Local Disk C
Then visit the folder where the wheel file exists and run pip install <*wheel file's name*>
Finally run the command pip install Scrapy again and you're good to use Scrapy or any other tool which required you to download massive Windows C++ Package/SDK.

Disclaimer: This solution worked for me while trying to install Scrapy, but I can't guarantee the same happening while installing other softwares/packages/etc.?

Search for a string in Enum and return the Enum

You can use Enum.Parse to get an enum value from the name. You can iterate over all values with Enum.GetNames, and you can just cast an int to an enum to get the enum value from the int value.

Like this, for example:

public MyColours GetColours(string colour)
{
    foreach (MyColours mc in Enum.GetNames(typeof(MyColours))) {
        if (mc.ToString().Contains(colour)) {
            return mc;
        }
    }
    return MyColours.Red; // Default value
}

or:

public MyColours GetColours(string colour)
{
    return (MyColours)Enum.Parse(typeof(MyColours), colour, true); // true = ignoreCase
}

The latter will throw an ArgumentException if the value is not found, you may want to catch it inside the function and return the default value.

How to get file name from file path in android

The easiest solution is to use Uri.getLastPathSegment():

String filename = uri.getLastPathSegment();

How to get folder directory from HTML input type "file" or any other way?

Stumbled on this page as well, and then found out this is possible with just javascript (no plugins like ActiveX or Flash), but just in chrome:

https://plus.google.com/+AddyOsmani/posts/Dk5UhZ6zfF3

Basically, they added support for a new attribute on the file input element "webkitdirectory". You can use it like this:

<input type="file" id="ctrl" webkitdirectory directory multiple/>

It allows you to select directories. The multiple attribute is a good fallback for browsers that support multiple file selection but not directory selection.

When you select a directory the files are available through the dom object for the control (document.getElementById('ctrl')), just like they are with the multiple attribute. The browsers adds all files in the selected directory to that list recursively.

You can already add the directory attribute as well in case this gets standardized at some point (couldn't find any info regarding that)

Bootstrap number validation

You should use jquery validation because if you use type="number" then you can also enter "E" character in input type, which is not correct.

Solution:

HTML

<input class="form-control floatNumber" name="energy1_total_power_generated" type="text" required="" >

JQuery

//integer value validation
$('input.floatNumber').on('input', function() {
    this.value = this.value.replace(/[^0-9.]/g,'').replace(/(\..*)\./g, '$1');
});

Array of strings in groovy

Most of the time you would create a list in groovy rather than an array. You could do it like this:

names = ["lucas", "Fred", "Mary"]

Alternately, if you did not want to quote everything like you did in the ruby example, you could do this:

names = "lucas Fred Mary".split()

R: Plotting a 3D surface from x, y, z

If your x and y coords are not on a grid then you need to interpolate your x,y,z surface onto one. You can do this with kriging using any of the geostatistics packages (geoR, gstat, others) or simpler techniques such as inverse distance weighting.

I'm guessing the 'interp' function you mention is from the akima package. Note that the output matrix is independent of the size of your input points. You could have 10000 points in your input and interpolate that onto a 10x10 grid if you wanted. By default akima::interp does it onto a 40x40 grid:

require(akima)
require(rgl)

x = runif(1000)
y = runif(1000)
z = rnorm(1000)
s = interp(x,y,z)
> dim(s$z)
[1] 40 40
surface3d(s$x,s$y,s$z)

That'll look spiky and rubbish because its random data. Hopefully your data isnt!

Get all messages from Whatsapp

You can get access to the WhatsApp data base located on the SD card only as a root user I think. if you open "\data\data\com.whatsapp" you will see that "databases" is linked to "\firstboot\sqlite\com.whatsapp\"

How do I list all tables in a schema in Oracle SQL?

select TABLE_NAME from user_tables;

Above query will give you the names of all tables present in that user;

iPhone and WireShark

I had to do something very similar to find out why my iPhone was bleeding cellular network data, eating 80% of my 500Mb allowance in a couple of days.

Unfortunately I had to packet sniff whilst on 3G/4G and couldn't rely on being on wireless. So if you need an "industrial" solution then this is how you sniff all traffic (not just http) on any network.

Basic recipe:

Install VPN server
Run packet sniffer on VPN server
Connect iPhone to VPN server and perform operations
Download .pcap from VPN server and use your favourite .pcap analyser on it.

Detailed'ish instructions:

Get yourself a linux server, I used Fedora 20 64bit from Digirtal Ocean on a $5/month box
Configure OpenVPN on it. OpenVPN has comprehensive instructions
Ensure you configure the Routing all traffic through the VPN section
Be aware the instructions for (3) are all iptables which has been superseded, at time of writing, by firewall-cmd. This website explains the firewall-cmd to use
Check that you can connect your iPhone to the VPN. I did this by downloading the free OpenVPN software. I then set up a OpenVPN certificate. You can embed your ca, crt & key files by opening up and embedding the --- BEGIN CERTIFACTE --- ---- END CERTIFICATE --- in < ca > < /ca > < crt >< /crt>< key > < /key > blocks. Note that I had to do this in Mac with text editor, when I used notepad.exe on Win it didn't work. I then emailed this to my iphone and picked installed it.
Check the iPhone connects to VPN and routes it's traffic through (google what's my IP should return the VPN server IP when you run it on iPhone)
Now that you can connect go to your linux server & install wireshark (yum install wireshark)
This installs tshark, which is a command line packet sniffer. Run this in the background with screen tshark -i tun0 -x -w capture.pcap -F pcap (assuming vpn device is tun0)
Now when you want to capture traffic simply start the VPN on your machine
When complete switch off the VPN
Download the .pcap file from your server, and run analysis as you normally would. It's been decrypted on the server when it arrives so the traffic is viewable in plain text (obviously https still encrypted)

Note that the above implementation is not security focussed it's simply about getting a detailed packet capture of all of your iPhone's traffic on 3G/4G/Wireless networks

Show data on mouseover of circle

This concise example demonstrates common way how to create custom tooltip in d3.

_x000D_

var w = 500;_x000D_
var h = 150;_x000D_
_x000D_
var dataset = [5, 10, 15, 20, 25];_x000D_
_x000D_
// firstly we create div element that we can use as_x000D_
// tooltip container, it have absolute position and_x000D_
// visibility: hidden by default_x000D_
_x000D_
var tooltip = d3.select("body")_x000D_
  .append("div")_x000D_
  .attr('class', 'tooltip');_x000D_
_x000D_
var svg = d3.select("body")_x000D_
  .append("svg")_x000D_
  .attr("width", w)_x000D_
  .attr("height", h);_x000D_
_x000D_
// here we add some circles on the page_x000D_
_x000D_
var circles = svg.selectAll("circle")_x000D_
  .data(dataset)_x000D_
  .enter()_x000D_
  .append("circle");_x000D_
_x000D_
circles.attr("cx", function(d, i) {_x000D_
    return (i * 50) + 25;_x000D_
  })_x000D_
  .attr("cy", h / 2)_x000D_
  .attr("r", function(d) {_x000D_
    return d;_x000D_
  })_x000D_
  _x000D_
  // we define "mouseover" handler, here we change tooltip_x000D_
  // visibility to "visible" and add appropriate test_x000D_
  _x000D_
  .on("mouseover", function(d) {_x000D_
    return tooltip.style("visibility", "visible").text('radius = ' + d);_x000D_
  })_x000D_
  _x000D_
  // we move tooltip during of "mousemove"_x000D_
  _x000D_
  .on("mousemove", function() {_x000D_
    return tooltip.style("top", (event.pageY - 30) + "px")_x000D_
      .style("left", event.pageX + "px");_x000D_
  })_x000D_
  _x000D_
  // we hide our tooltip on "mouseout"_x000D_
  _x000D_
  .on("mouseout", function() {_x000D_
    return tooltip.style("visibility", "hidden");_x000D_
  });

_x000D_

.tooltip {_x000D_
    position: absolute;_x000D_
    z-index: 10;_x000D_
    visibility: hidden;_x000D_
    background-color: lightblue;_x000D_
    text-align: center;_x000D_
    padding: 4px;_x000D_
    border-radius: 4px;_x000D_
    font-weight: bold;_x000D_
    color: orange;_x000D_
}

_x000D_

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.11.0/d3.min.js"></script>

_x000D_

Maven : error in opening zip file when running maven

I downloaded the jar file manually and replace the one in my local directory and it worked

Bash mkdir and subfolders

You can:

mkdir -p folder/subfolder

The -p flag causes any parent directories to be created if necessary.

Required request body content is missing: org.springframework.web.method.HandlerMethod$HandlerMethodParameter

I also had the same problem. I use "Postman" for JSON request. The code itself is not wrong. I simply set the content type to JSON (application/json) and it worked, as you can see on the image below

Sending mass email using PHP

First off, using the mail() function that comes with PHP is not an optimal solution. It is easily marked as spammed, and you need to set up header to ensure that you are sending HTML emails correctly. As for whether the code snippet will work, it would, but I doubt you will get HTML code inside it correctly without specifying extra headers

I'll suggest you take a look at SwiftMailer, which has HTML support, support for different mime types and SMTP authentication (which is less likely to mark your mail as spam).

Google Maps setCenter()

For me above solutions didn't work then I tried

map.setCenter(new google.maps.LatLng(lat, lng));

and it worked as expected.

@UniqueConstraint and @Column(unique = true) in hibernate annotation

In addition to Boaz's answer ....

@UniqueConstraint allows you to name the constraint, while @Column(unique = true) generates a random name (e.g. UK_3u5h7y36qqa13y3mauc5xxayq).

Sometimes it can be helpful to know what table a constraint is associated with. E.g.:

@Table(
   name = "product_serial_group_mask", 
   uniqueConstraints = {
      @UniqueConstraint(
          columnNames = {"mask", "group"},
          name="uk_product_serial_group_mask"
      )
   }
)

C++ equivalent of Java's toString?

You can also do it this way, allowing polymorphism:

class Base {
public:
   virtual std::ostream& dump(std::ostream& o) const {
      return o << "Base: " << b << "; ";
   }
private:
  int b;
};

class Derived : public Base {
public:
   virtual std::ostream& dump(std::ostream& o) const {
      return o << "Derived: " << d << "; ";
   }
private:
   int d;
}

std::ostream& operator<<(std::ostream& o, const Base& b) { return b.dump(o); }

How to ping multiple servers and return IP address and Hostnames using batch script?

Well, it's unfortunate that you didn't post your own code too, so that it could be corrected.
Anyway, here's my own solution to this:

@echo off
setlocal enabledelayedexpansion

set OUTPUT_FILE=result.txt
>nul copy nul %OUTPUT_FILE%
for /f %%i in (testservers.txt) do (
    set SERVER_ADDRESS=ADDRESS N/A
    for /f "tokens=1,2,3" %%x in ('ping -n 1 %%i ^&^& echo SERVER_IS_UP') do (
        if %%x==Pinging set SERVER_ADDRESS=%%y
        if %%x==Reply set SERVER_ADDRESS=%%z
        if %%x==SERVER_IS_UP (set SERVER_STATE=UP) else (set SERVER_STATE=DOWN)
    )
    echo %%i [!SERVER_ADDRESS::=!] is !SERVER_STATE! >>%OUTPUT_FILE%
)

The outer loop iterates through the hosts and the inner loop parses the ping output. The first two if statements handle the two possible cases of IP address resolution:

The host name is the host IP address.
The host IP address can be resolved from its name.

If the host IP address cannot be resolved, the address is set to "ADDRESS N/A".

Hope this helps.

Adding an arbitrary line to a matplotlib plot in ipython notebook

Using vlines:

import numpy as np
np.random.seed(5)
x = arange(1, 101)
y = 20 + 3 * x + np.random.normal(0, 60, 100)
p =  plot(x, y, "o")
vlines(70,100,250)

The basic call signatures are:

vlines(x, ymin, ymax)
hlines(y, xmin, xmax)

Prevent scrolling of parent element when inner element scroll position reaches top/bottom?

This actually works in AngularJS. Tested on Chrome and Firefox.

.directive('stopScroll', function () {
    return {
        restrict: 'A',
        link: function (scope, element, attr) {
            element.bind('mousewheel', function (e) {
                var $this = $(this),
                    scrollTop = this.scrollTop,
                    scrollHeight = this.scrollHeight,
                    height = $this.height(),
                    delta = (e.type == 'DOMMouseScroll' ?
                    e.originalEvent.detail * -40 :
                        e.originalEvent.wheelDelta),
                    up = delta > 0;

                var prevent = function() {
                    e.stopPropagation();
                    e.preventDefault();
                    e.returnValue = false;
                    return false;
                };

                if (!up && -delta > scrollHeight - height - scrollTop) {
                    // Scrolling down, but this will take us past the bottom.
                    $this.scrollTop(scrollHeight);
                    return prevent();
                } else if (up && delta > scrollTop) {
                    // Scrolling up, but this will take us past the top.
                    $this.scrollTop(0);
                    return prevent();
                }
            });
        }
    };
})

How to set default text for a Tkinter Entry widget

Use Entry.insert. For example:

try:
    from tkinter import *  # Python 3.x
except Import Error:
    from Tkinter import *  # Python 2.x

root = Tk()
e = Entry(root)
e.insert(END, 'default text')
e.pack()
root.mainloop()

Or use textvariable option:

try:
    from tkinter import *  # Python 3.x
except Import Error:
    from Tkinter import *  # Python 2.x

root = Tk()
v = StringVar(root, value='default text')
e = Entry(root, textvariable=v)
e.pack()
root.mainloop()

How to Automatically Start a Download in PHP?

A clean example.

<?php
    header('Content-Type: application/download');
    header('Content-Disposition: attachment; filename="example.txt"');
    header("Content-Length: " . filesize("example.txt"));

    $fp = fopen("example.txt", "r");
    fpassthru($fp);
    fclose($fp);
?>

How to set a default value for an existing column

You can use following syntax, For more information see this question and answers : Add a column with a default value to an existing table in SQL Server

Syntax :

ALTER TABLE {TABLENAME} 
ADD {COLUMNNAME} {TYPE} {NULL|NOT NULL} 
CONSTRAINT {CONSTRAINT_NAME} DEFAULT {DEFAULT_VALUE}
WITH VALUES

Example :

ALTER TABLE SomeTable
ADD SomeCol Bit NULL --Or NOT NULL.
CONSTRAINT D_SomeTable_SomeCol --When Omitted a Default-Constraint Name is 
autogenerated.
DEFAULT (0)--Optional Default-Constraint.
WITH VALUES --Add if Column is Nullable and you want the Default Value for Existing Records.

Another way :

Right click on the table and click on Design,then click on column that you want to set default value.

Then in bottom of page add a default value or binding : something like '1' for string or 1 for int.

How do I cast a JSON Object to a TypeScript class?

https://jvilk.com/MakeTypes/

you can use this site to generate a proxy for you. it generates a class and can parse and validate your input JSON object.

Div table-cell vertical align not working

You can vertically align a floated element in a way which works on IE 6+. It doesn't need full table markup either. This method isn't perfectly clean - includes wrappers and there are a few things to be aware of e.g. if you have too much text outspilling the container - but it's pretty good.

Short answer: You just need to apply display: table-cell to an element inside the floated element (table cells don't float), and use a fallback with position: absolute and top for old IE.

Long answer: Here's a jsfiddle showing the basics. The important stuff summarized (with a conditional comment adding an .old-ie class):

    .wrap {
        float: left;
        height: 100px; /* any fixed amount */
    }
    .wrap2 {
        height: inherit;
    }
    .content {
        display: table-cell;
        height: inherit;
        vertical-align: middle;
    }

    .old-ie .wrap{
        position: relative;
    }
    .old-ie .wrap2 {
        position: absolute;
        top: 50%;
    }
    .old-ie .content {
        position: relative;
        top: -50%;
        display: block;
    }

Here's a jsfiddle that deliberately highlight the minor faults with this method. Note how:

In standards browsers, content that exceeds the height of the wrapper element stops centering and starts going down the page. This isn't a big problem (probably looks better than creeping up the page), and can be avoided by avoiding content that is too big (note that unless I've overlooked something, overflow methods like overflow: auto; don't seem to work)
In old IE, the content element doesn't stretch to fill the available space - the height is the height of the content, not of the container.

Those are pretty minor limitations, but worth being aware of.

Code and idea adapted from here

Real escape string and PDO

PDO offers an alternative designed to replace mysql_escape_string() with the PDO::quote() method.

Here is an excerpt from the PHP website:

<?php
    $conn = new PDO('sqlite:/home/lynn/music.sql3');

    /* Simple string */
    $string = 'Nice';
    print "Unquoted string: $string\n";
    print "Quoted string: " . $conn->quote($string) . "\n";
?>

The above code will output:

Unquoted string: Nice
Quoted string: 'Nice'

Git on Bitbucket: Always asked for password, even after uploading my public SSH key

If you are using a Ubuntu system, use the following to Store Password Permanently:

git config --global credential.helper store

How to parse Excel (XLS) file in Javascript/HTML5

Thank you for the answer above, I think the scope (of answers) is completed but I would like to add a "react way" for whoever using react.

Create a file called importData.js:

import React, {Component} from 'react';
import XLSX from 'xlsx';
export default class ImportData extends Component{
    constructor(props){
        super(props);
        this.state={
            excelData:{}
        }
    }
    excelToJson(reader){
        var fileData = reader.result;
        var wb = XLSX.read(fileData, {type : 'binary'});
        var data = {};
        wb.SheetNames.forEach(function(sheetName){
             var rowObj =XLSX.utils.sheet_to_row_object_array(wb.Sheets[sheetName]);
             var rowString = JSON.stringify(rowObj);
             data[sheetName] = rowString;
        });
        this.setState({excelData: data});
    }
    loadFileXLSX(event){
        var input = event.target;
        var reader = new FileReader();
        reader.onload = this.excelToJson.bind(this,reader);
        reader.readAsBinaryString(input.files[0]);
    }
    render(){
        return (
            <input type="file" onChange={this.loadFileXLSX.bind(this)}/>
        );
    }
}

Then you can use the component in the render method like:

import ImportData from './importData.js';
import React, {Component} from 'react';
class ParentComponent extends Component{
    render(){
        return (<ImportData/>);
    }
}

<ImportData/> would set the data to its own state, you can access Excel data in the "parent component" by following this:

How to call a Web Service Method?

write return(secondmethod) inside of the first method

PostgreSQL delete with inner join

This worked for me:

DELETE from m_productprice
WHERE  m_pricelist_version_id='1000020'
       AND m_product_id IN (SELECT m_product_id
                            FROM   m_product
                            WHERE  upc = '7094');

Android: Difference between Parcelable and Serializable?

Parcelable much faster than serializable with Binder, because serializable use reflection and cause many GC. Parcelable is design to optimize to pass object.

Here's link to reference. http://www.developerphil.com/parcelable-vs-serializable/

In Mongoose, how do I sort by date? (node.js)

This one works for me.

`Post.find().sort({postedon: -1}).find(function (err, sortedposts){
    if (err) 
        return res.status(500).send({ message: "No Posts." });
    res.status(200).send({sortedposts : sortedposts});
 });`

How to merge 2 List<T> and removing duplicate values from it in C#

Union has not good performance : this article describe about compare them with together

var dict = list2.ToDictionary(p => p.Number);
foreach (var person in list1)
{
        dict[person.Number] = person;
}
var merged = dict.Values.ToList();

Lists and LINQ merge: 4820ms
Dictionary merge: 16ms
HashSet and IEqualityComparer: 20ms
LINQ Union and IEqualityComparer: 24ms

Angular HTML binding

In Angular 2 you can do 3 types of bindings:

[property]="expression" -> Any html property can link to an
expression. In this case, if expression changes property will update, but this doesn't work the other way.
(event)="expression" -> When event activates execute expression.
[(ngModel)]="property" -> Binds the property from js (or ts) to html. Any update on this property will be noticeable everywhere.

An expression can be a value, an attribute or a method. For example: '4', 'controller.var', 'getValue()'

Example here

jQuery window scroll event does not fire up

Nothing seemd to work for me, but this did the trick

$(parent.window.document).scroll(function() {
    alert("bottom!");
});

Right click to select a row in a Datagridview and show a menu to delete it

private void dataGridView1_CellContextMenuStripNeeded(object sender, 
DataGridViewCellContextMenuStripNeededEventArgs e)
{            
    if (e.RowIndex != -1)
    {
        dataGridView1.ClearSelection();
        this.dataGridView1.Rows[e.RowIndex].Selected = true;
        e.ContextMenuStrip = contextMenuStrip1;
    }
}

Programs & Examples On #Grails constraints

How can I define a composite primary key in SQL?

How to change href of <a> tag on button click through javascript

Align text to the bottom of a div

How to create a sticky footer that plays well with Bootstrap 3

Example for boost shared_mutex (multiple reads/one write)?

Convert 4 bytes to int

How do I get client IP address in ASP.NET CORE?

How to replace (null) values with 0 output in PIVOT

How to start IDLE (Python editor) without using the shortcut on Windows Vista?

What is LDAP used for?

Python ValueError: too many values to unpack

Using boolean values in C

Javascript: The prettiest way to compare one value against multiple values

What is &#39; and why does Google search replace it with apostrophe?

How to parse a string in JavaScript?

How can I get the content of CKEditor using JQuery?

How to remove part of a string before a ":" in javascript?

Bootstrap get div to align in the center

Selecting all text in HTML text input when clicked

Could not load file or assembly System.Web.Http.WebHost after published to Azure web site

When should I use a struct rather than a class in C#?

AWS ssh access 'Permission denied (publickey)' issue

Database, Table and Column Naming Conventions?

Browser can't access/find relative resources like CSS, images and links when calling a Servlet which forwards to a JSP

How can I easily view the contents of a datatable or dataview in the immediate window

Assign variable value inside if-statement

How can I get list of values from dict?

How to list only top level directories in Python?

TypeError: 'list' object cannot be interpreted as an integer

Prevent BODY from scrolling when a modal is opened

How to use absolute path in twig functions

Uncaught TypeError: Cannot read property 'top' of undefined

'cl' is not recognized as an internal or external command,

What are the differences between a superkey and a candidate key?

Can't clone a github repo on Linux via HTTPS

Cannot implicitly convert type from Task<>

Search for executable files using find command

check if jquery has been loaded, then load it if false

Python find min max and average of a list (array)

Check if a number is odd or even in python

how to permit an array with strong parameters

Dynamically add properties to a existing object

Fatal error: Cannot use object of type stdClass as array in

Simple Android grid example using RecyclerView with GridLayoutManager (like the old GridView)

How to change the default port of mysql from 3306 to 3360

What does "Error: object '<myvariable>' not found" mean?

Chrome Dev Tools - Modify javascript and reload

How to set the color of an icon in Angular Material?

Adding 30 minutes to time formatted as H:i in PHP

How do I find out which computer is the domain controller in Windows programmatically?

Is there any good dynamic SQL builder library in Java?

How do I set up Visual Studio Code to compile C++ code?

Table and Index size in SQL Server

What is a 'workspace' in Visual Studio Code?

Unknown version of Tomcat was specified in Eclipse

Apply CSS rules to a nested class inside a div

NoClassDefFoundError on Maven dependency

Array to Collection: Optimized code

String escape into XML

Error in <my code> : object of type 'closure' is not subsettable

Disable scrolling when touch moving certain element

How to calculate rolling / moving average using NumPy / SciPy?

Recursively add the entire folder to a repository

What is the meaning of @_ in Perl?

MySQL Server has gone away when importing large sql file

How do you add a scroll bar to a div?

make iframe height dynamic based on content inside- JQUERY/Javascript

Twitter - How to embed native video from someone else's tweet into a New Tweet or a DM

Trigger change() event when setting <select>'s value with val() function

How to parse this string in Java?

What are intent-filters in Android?

c++ "Incomplete type not allowed" error accessing class reference information (Circular dependency with forward declaration)

How to rename a table column in Oracle 10g

How to have multiple conditions for one if statement in python

Mocking methods of local scope objects with Mockito

What is the scope of variables in JavaScript?

TLDR

Overview

Declaration Styles

What is ' and why does Google search replace it with apostrophe?

Is init.py not required for packages in Python 3.3+