editing PATH variable on mac

Based on my own experiences and internet search, I find these places work:

/etc/paths.d

~/.bash_profile

Note that you should open a new terminal window to see the changes.

You may also refer to this this question

How to loop through all but the last item of a list?

if you meant comparing nth item with n+1 th item in the list you could also do with

>>> for i in range(len(list[:-1])):
...     print list[i]>list[i+1]

note there is no hard coding going on there. This should be ok unless you feel otherwise.

Text editor to open big (giant, huge, large) text files

Tips and tricks

less

Why are you using editors to just look at a (large) file?

Under *nix or Cygwin, just use less. (There is a famous saying – "less is more, more or less" – because "less" replaced the earlier Unix command "more", with the addition that you could scroll back up.) Searching and navigating under less is very similar to Vim, but there is no swap file and little RAM used.

There is a Win32 port of GNU less. See the "less" section of the answer above.

Perl

Perl is good for quick scripts, and its .. (range flip-flop) operator makes for a nice selection mechanism to limit the crud you have to wade through.

For example:

$ perl -n -e 'print if ( 1000000 .. 2000000)' humongo.txt | less

This will extract everything from line 1 million to line 2 million, and allow you to sift the output manually in less.

Another example:

$ perl -n -e 'print if ( /regex one/ .. /regex two/)' humongo.txt | less

This starts printing when the "regular expression one" finds something, and stops when the "regular expression two" find the end of an interesting block. It may find multiple blocks. Sift the output...

logparser

This is another useful tool you can use. To quote the Wikipedia article:

logparser is a flexible command line utility that was initially written by Gabriele Giuseppini, a Microsoft employee, to automate tests for IIS logging. It was intended for use with the Windows operating system, and was included with the IIS 6.0 Resource Kit Tools. The default behavior of logparser works like a "data processing pipeline", by taking an SQL expression on the command line, and outputting the lines containing matches for the SQL expression.

Microsoft describes Logparser as a powerful, versatile tool that provides universal query access to text-based data such as log files, XML files and CSV files, as well as key data sources on the Windows operating system such as the Event Log, the Registry, the file system, and Active Directory. The results of the input query can be custom-formatted in text based output, or they can be persisted to more specialty targets like SQL, SYSLOG, or a chart.

Example usage:

C:\>logparser.exe -i:textline -o:tsv "select Index, Text from 'c:\path\to\file.log' where line > 1000 and line < 2000"
C:\>logparser.exe -i:textline -o:tsv "select Index, Text from 'c:\path\to\file.log' where line like '%pattern%'"

The relativity of sizes

100 MB isn't too big. 3 GB is getting kind of big. I used to work at a print & mail facility that created about 2% of U.S. first class mail. One of the systems for which I was the tech lead accounted for about 15+% of the pieces of mail. We had some big files to debug here and there.

And more...

Feel free to add more tools and information here. This answer is community wiki for a reason! We all need more advice on dealing with large amounts of data...

Java using enum with switch statement

If whichView is an object of the GuideView Enum, following works well. Please note that there is no qualifier for the constant after case.

switch (whichView) {
    case SEVEN_DAY:
        ...
        break;
    case NOW_SHOWING:
        ...
        break;
}

Writing to CSV with Python adds blank lines

Pyexcel works great with both Python2 and Python3 without troubles.

Fast installation with pip:

pip install pyexcel

After that, only 3 lines of code and the job is done:

import pyexcel
data = [['Me', 'You'], ['293', '219'], ['54', '13']]
pyexcel.save_as(array = data, dest_file_name = 'csv_file_name.csv')

Cancel split window in Vim

Okay I just detached and reattach to the screen session and I am back to normal screen I wanted

Windows batch script to unhide files hidden by virus

this will unhide all files and folders on your computer

attrib -r -s -h /S /D

Remove a fixed prefix/suffix from a string in Bash

I use grep for removing prefixes from paths (which aren't handled well by sed):

echo "$input" | grep -oP "^$prefix\K.*"

\K removes from the match all the characters before it.

Map with Key as String and Value as List in Groovy

Groovy accepts nearly all Java syntax, so there is a spectrum of choices, as illustrated below:

// Java syntax 

Map<String,List> map1  = new HashMap<>();
List list1 = new ArrayList();
list1.add("hello");
map1.put("abc", list1); 
assert map1.get("abc") == list1;

// slightly less Java-esque

def map2  = new HashMap<String,List>()
def list2 = new ArrayList()
list2.add("hello")
map2.put("abc", list2)
assert map2.get("abc") == list2

// typical Groovy

def map3  = [:]
def list3 = []
list3 << "hello"
map3.'abc'= list3
assert map3.'abc' == list3

setting an environment variable in virtualenv

If you're already using Heroku, consider running your server via Foreman. It supports a .env file which is simply a list of lines with KEY=VAL that will be exported to your app before it runs.

Why is semicolon allowed in this python snippet?

Python does let you use a semi-colon to denote the end of a statement if you are including more than one statement on a line.

javascript regex - look behind alternative?

EDIT: From ECMAScript 2018 onwards, lookbehind assertions (even unbounded) are supported natively.

In previous versions, you can do this:

^(?:(?!filename\.js$).)*\.js$

This does explicitly what the lookbehind expression is doing implicitly: check each character of the string if the lookbehind expression plus the regex after it will not match, and only then allow that character to match.

^                 # Start of string
(?:               # Try to match the following:
 (?!              # First assert that we can't match the following:
  filename\.js    # filename.js 
  $               # and end-of-string
 )                # End of negative lookahead
 .                # Match any character
)*                # Repeat as needed
\.js              # Match .js
$                 # End of string

Another edit:

It pains me to say (especially since this answer has been upvoted so much) that there is a far easier way to accomplish this goal. There is no need to check the lookahead at every character:

^(?!.*filename\.js$).*\.js$

works just as well:

^                 # Start of string
(?!               # Assert that we can't match the following:
 .*               # any string, 
  filename\.js    # followed by filename.js
  $               # and end-of-string
)                 # End of negative lookahead
.*                # Match any string
\.js              # Match .js
$                 # End of string

How to set the Default Page in ASP.NET?

if you are using login page in your website go to web.config file

<authentication mode="Forms">
  <forms loginUrl="login.aspx" defaultUrl="index.aspx"  >
    </forms>
</authentication>

replace your authentication tag to above (where index.aspx will be your startup page)

and one more thing write this in your web.config file inside

<configuration>
   <system.webServer>
   <defaultDocument>
    <files>
     <clear />
     <add value="index.aspx" />
    </files>
  </defaultDocument>
  </system.webServer>

  <location path="index.aspx">
    <system.web>
      <authorization>
        <allow users="*" />
      </authorization>
   </system.web>
  </location>
</configuration>

Slice indices must be integers or None or have index method

Your debut and fin values are floating point values, not integers, because taille is a float.

Make those values integers instead:

item = plateau[int(debut):int(fin)]

Alternatively, make taille an integer:

taille = int(sqrt(len(plateau)))

What jar should I include to use javax.persistence package in a hibernate based application?

If you are using maven, adding below dependency should work

<dependency>
    <groupId>javax.persistence</groupId>
    <artifactId>persistence-api</artifactId>
    <version>1.0</version>
</dependency>

Python "TypeError: unhashable type: 'slice'" for encoding categorical data

if you use .Values while creating the matrix X and Y vectors it will fix the problem.

y=dataset.iloc[:, 4].values

X=dataset.iloc[:, 0:4].values

when you use .Values it creates a Object representation of the created matrix will be returned with the axes removed. Check the below link for more information

https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.values.html

make a header full screen (width) css

Just set the header width to be 100vw to make it full screen width and set the header height to be 100vh to make it full screen height

How to force a web browser NOT to cache images

use Class="NO-CACHE"

sample html:

<div>
    <img class="NO-CACHE" src="images/img1.jpg" />
    <img class="NO-CACHE" src="images/imgLogo.jpg" />
</div>

jQuery:

    $(document).ready(function ()
    {           
        $('.NO-CACHE').attr('src',function () { return $(this).attr('src') + "?a=" + Math.random() });
    });

javascript:

var nods = document.getElementsByClassName('NO-CACHE');
for (var i = 0; i < nods.length; i++)
{
    nods[i].attributes['src'].value += "?a=" + Math.random();
}

Result: src="images/img1.jpg" => src="images/img1.jpg?a=0.08749723793963926"

Passing data between different controller action methods

HTTP and redirects

Let's first recap how ASP.NET MVC works:

When an HTTP request comes in, it is matched against a set of routes. If a route matches the request, the controller action corresponding to the route will be invoked.
Before invoking the action method, ASP.NET MVC performs model binding. Model binding is the process of mapping the content of the HTTP request, which is basically just text, to the strongly typed arguments of your action method

Let's also remind ourselves what a redirect is:

An HTTP redirect is a response that the webserver can send to the client, telling the client to look for the requested content under a different URL. The new URL is contained in a Location header that the webserver returns to the client. In ASP.NET MVC, you do an HTTP redirect by returning a RedirectResult from an action.

Passing data

If you were just passing simple values like strings and/or integers, you could pass them as query parameters in the URL in the Location header. This is what would happen if you used something like

return RedirectToAction("ActionName", "Controller", new { arg = updatedResultsDocument });

as others have suggested

The reason that this will not work is that the XDocument is a potentially very complex object. There is no straightforward way for the ASP.NET MVC framework to serialize the document into something that will fit in a URL and then model bind from the URL value back to your XDocument action parameter.

In general, passing the document to the client in order for the client to pass it back to the server on the next request, is a very brittle procedure: it would require all sorts of serialisation and deserialisation and all sorts of things could go wrong. If the document is large, it might also be a substantial waste of bandwidth and might severely impact the performance of your application.

Instead, what you want to do is keep the document around on the server and pass an identifier back to the client. The client then passes the identifier along with the next request and the server retrieves the document using this identifier.

Storing data for retrieval on the next request

So, the question now becomes, where does the server store the document in the meantime? Well, that is for you to decide and the best choice will depend upon your particular scenario. If this document needs to be available in the long run, you may want to store it on disk or in a database. If it contains only transient information, keeping it in the webserver's memory, in the ASP.NET cache or the Session (or TempData, which is more or less the same as the Session in the end) may be the right solution. Either way, you store the document under a key that will allow you to retrieve the document later:

int documentId = _myDocumentRepository.Save(updatedResultsDocument);

and then you return that key to the client:

return RedirectToAction("UpdateConfirmation", "ApplicationPoolController ", new { id = documentId });

When you want to retrieve the document, you simply fetch it based on the key:

 public ActionResult UpdateConfirmation(int id)
 {
      XDocument doc = _myDocumentRepository.GetById(id);

      ConfirmationModel model = new ConfirmationModel(doc);

      return View(model);
 }

How to add multiple columns to pandas dataframe in one assignment?

if adding a lot of missing columns (a, b, c ,....) with the same value, here 0, i did this:

    new_cols = ["a", "b", "c" ] 
    df[new_cols] = pd.DataFrame([[0] * len(new_cols)], index=df.index)

It's based on the second variant of the accepted answer.

What is the difference between compare() and compareTo()?

compareTo(T object)

comes from the java.lang.Comparable interface, implemented to compare this object with another to give a negative int value for this object being less than, 0 for equals, or positive value for greater than the other. This is the more convenient compare method, but must be implemented in every class you want to compare.

compare(T obj1, T obj2)

comes from the java.util.Comparator interface, implemented in a separate class that compares another class's objects to give a negative int value for the first object being less than, 0 for equals, or positive value for greater than the second object. It is needed when you cannot make a class implement compareTo() because it is not modifiable. It is also used when you want different ways to compare objects, not just one (such as by name or age).

Counting the number of elements in array

Best practice of getting length is use length filter returns the number of items of a sequence or mapping, or the length of a string. For example: {{ notcount | length }}

But you can calculate count of elements in for loop. For example:

{% set count = 0 %}
{% for nc in notcount %}
    {% set count = count + 1 %}
{% endfor %}

{{ count }}

This solution helps if you want to calculate count of elements by condition, for example you have a property name inside object and you want to calculate count of objects with not empty names:

{% set countNotEmpty = 0 %}
{% for nc in notcount if nc.name %}
    {% set countNotEmpty = countNotEmpty + 1 %}
{% endfor %}

{{ countNotEmpty }}

Useful links:

Could not load type from assembly error

I had the same issue and for me it had nothing to do with namespace or project naming.

But as several users hinted at it had to do with an old assembly still being referenced.

I recommend to delete all "bin"/binary folders of all projects and to re-build the whole solution. This washed out any potentially outdated assemblies and after that MEF exported all my plugins without issue.

SQL Server: Get data for only the past year

I, like @D.E. White, came here for similar but different reasons than the original question. The original question asks for the last 365 days. @samjudson's answer provides that. @D.E. White's answer returns results for the prior calendar year.

My query is a bit different in that it works for the prior year up to and including the current date:

SELECT .... FROM .... WHERE year(date) > year(DATEADD(year, -2, GETDATE()))

For example, on Feb 17, 2017 this query returns results from 1/1/2016 to 2/17/2017

How to make an Android Spinner with initial text "Select One"?

I found many good solutions for this. most is working by adding an item to the end of adapter, and don't display the last item in drop-down list. The big problem for me was the spinner drop-down list will start from the bottom of the list. So user see the last items instead of the first items (in case of have many items to show), after touch the spinner for the first time.

So I put the hint item to the beginning of the list. and hide the first item in drop-down list.

private void loadSpinner(){

    HintArrayAdapter hintAdapter = new HintArrayAdapter<String>(context, 0);

    hintAdapter.add("Hint to be displayed");
    hintAdapter.add("Item 1");
    hintAdapter.add("Item 2");
            .
            .
    hintAdapter.add("Item 30");

    spinner1.setAdapter(hintAdapter);

    //spinner1.setSelection(0); //display hint. Actually you can ignore it, because the default is already 0
    //spinner1.setSelection(0, false); //use this if don't want to onItemClick called for the hint

    spinner1.setOnItemSelectedListener(yourListener);
}

private class HintArrayAdapter<T> extends ArrayAdapter<T> {

    Context mContext;

    public HintArrayAdapter(Context context, int resource) {
        super(context, resource);
        this.mContext = context
    }

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

        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        View view = inflater.inflate(android.R.layout.simple_spinner_item, parent, false);
        TextView texview = (TextView) view.findViewById(android.R.id.text1);

        if(position == 0) {
            texview.setText("");
            texview.setHint(getItem(position).toString()); //"Hint to be displayed"
        } else {
            texview.setText(getItem(position).toString());
        }

        return view;
    }

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

        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        View view;

        if(position == 0){
            view = inflater.inflate(R.layout.spinner_hint_list_item_layout, parent, false); // Hide first row
        } else {
            view = inflater.inflate(android.R.layout.simple_spinner_dropdown_item, parent, false);
            TextView texview = (TextView) view.findViewById(android.R.id.text1);
            texview.setText(getItem(position).toString());
        } 

        return view;
    }
}

set the below layout in @Override getDropDownView() when position is 0, to hide the first hint row.

R.layout.spinner_hint_list_item_layout:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

</LinearLayout>

Format XML string to print friendly XML string

Customizable Pretty XML output with UTF-8 XML declaration

The following class definition gives a simple method to convert an input XML string into formatted output XML with the xml declaration as UTF-8. It supports all the configuration options that the XmlWriterSettings class offers.

using System;
using System.Text;
using System.Xml;
using System.IO;

namespace CJBS.Demo
{
    /// <summary>
    /// Supports formatting for XML in a format that is easily human-readable.
    /// </summary>
    public static class PrettyXmlFormatter
    {

        /// <summary>
        /// Generates formatted UTF-8 XML for the content in the <paramref name="doc"/>
        /// </summary>
        /// <param name="doc">XmlDocument for which content will be returned as a formatted string</param>
        /// <returns>Formatted (indented) XML string</returns>
        public static string GetPrettyXml(XmlDocument doc)
        {
            // Configure how XML is to be formatted
            XmlWriterSettings settings = new XmlWriterSettings 
            {
                Indent = true
                , IndentChars = "  "
                , NewLineChars = System.Environment.NewLine
                , NewLineHandling = NewLineHandling.Replace
                //,NewLineOnAttributes = true
                //,OmitXmlDeclaration = false
            };

            // Use wrapper class that supports UTF-8 encoding
            StringWriterWithEncoding sw = new StringWriterWithEncoding(Encoding.UTF8);

            // Output formatted XML to StringWriter
            using (XmlWriter writer = XmlWriter.Create(sw, settings))
            {
                doc.Save(writer);
            }

            // Get formatted text from writer
            return sw.ToString();
        }



        /// <summary>
        /// Wrapper class around <see cref="StringWriter"/> that supports encoding.
        /// Attribution: http://stackoverflow.com/a/427737/3063884
        /// </summary>
        private sealed class StringWriterWithEncoding : StringWriter
        {
            private readonly Encoding encoding;

            /// <summary>
            /// Creates a new <see cref="PrettyXmlFormatter"/> with the specified encoding
            /// </summary>
            /// <param name="encoding"></param>
            public StringWriterWithEncoding(Encoding encoding)
            {
                this.encoding = encoding;
            }

            /// <summary>
            /// Encoding to use when dealing with text
            /// </summary>
            public override Encoding Encoding
            {
                get { return encoding; }
            }
        }
    }
}

Possibilities for further improvement:-

An additional method GetPrettyXml(XmlDocument doc, XmlWriterSettings settings) could be created that allows the caller to customize the output.
An additional method GetPrettyXml(String rawXml) could be added that supports parsing raw text, rather than have the client use the XmlDocument. In my case, I needed to manipulate the XML using the XmlDocument, hence I didn't add this.

Usage:

String myFormattedXml = null;
XmlDocument doc = new XmlDocument();
try
{
    doc.LoadXml(myRawXmlString);
    myFormattedXml = PrettyXmlFormatter.GetPrettyXml(doc);
}
catch(XmlException ex)
{
    // Failed to parse XML -- use original XML as formatted XML
    myFormattedXml = myRawXmlString;
}

What is Hash and Range Primary Key?

@vnr you can retrieve all the sort keys associated with a partition key by just using the query using partion key. No need of scan. The point here is partition key is compulsory in a query . Sort key are used only to get range of data

How to get URL of current page in PHP

if you want just the parts of url after http://domain.com, try this:

<?php echo $_SERVER['REQUEST_URI']; ?>

if the current url was http://domain.com/some-slug/some-id, echo will return only '/some-slug/some-id'.

if you want the full url, try this:

<?php echo 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI']; ?>

Detecting the character encoding of an HTTP POST request

The Charset used in the POST will match that of the Charset specified in the HTML hosting the form. Hence if your form is sent using UTF-8 encoding that is the encoding used for the posted content. The URL encoding is applied after the values are converted to the set of octets for the character encoding.

Using "Object.create" instead of "new"

TL;DR:

new Computer() will invoke the constructor function Computer(){} for one time, while Object.create(Computer.prototype) won't.

All the advantages are based on this point.

Sidenote about performance: Constructor invoking like new Computer() is heavily optimized by the engine, so it may be even faster than Object.create.

How to call a asp:Button OnClick event using JavaScript?

Set style= "display:none;". By setting visible=false, it will not render button in the browser. Thus,client side script wont execute.

<asp:Button ID="savebtn" runat="server" OnClick="savebtn_Click" style="display:none" />

html markup should be

<button id="btnsave" onclick="fncsave()">Save</button>

Change javascript to

<script type="text/javascript">
     function fncsave()
     {
        document.getElementById('<%= savebtn.ClientID %>').click();
     }
</script>

How to write specific CSS for mozilla, chrome and IE

use agent detector and then with your web language create program to create css

for example in python

csscreator()
    useragent = detector()
    if useragent == "Firefox":
         css = "your css"
    ...
    return css

How to prevent robots from automatically filling up a form?

I've added a time check to my forms. The forms will not be submitted if filled in less than 3 seconds and this was working great for me especially for the long forms. Here's the form check function that I call on the submit button

function formCheck(){
var timeStart; 
var timediff;

$("input").bind('click keyup', function () {
    timeStart = new Date().getTime();          
}); 
 timediff= Math.round((new Date().getTime() - timeStart)/1000);

  if(timediff < 3) { 
    //throw a warning or don't submit the form 
  } 
  else submit(); // some submit function

}

Kubernetes pod gets recreated when deleted

This will provide information about all the pods,deployments, services and jobs in the namespace.

kubectl get pods,services, deployments, jobs

pods can either be created by deployments or jobs

kubectl delete job [job_name]
kubectl delete deployment [deployment_name]

If you delete the deployment or job then restart of the pods can be stopped.

Get Mouse Position

Try looking at the java.awt.Robot class. It allows you to move the mouse programatically.

Using command line arguments in VBscript

Set args = Wscript.Arguments

For Each arg In args
  Wscript.Echo arg
Next

From a command prompt, run the script like this:

CSCRIPT MyScript.vbs 1 2 A B "Arg with spaces"

Will give results like this:

1
2
A
B
Arg with spaces

Cross-Domain Cookies

There's no such thing as cross domain cookies. You could share a cookie between foo.example.com and bar.example.com but never between example.com and example2.com and that's for security reasons.

PHP shorthand for isset()?

PHP 7.4+; with the null coalescing assignment operator

$var ??= '';

PHP 7.0+; with the null coalescing operator

$var = $var ?? '';

PHP 5.3+; with the ternary operator shorthand

isset($var) ?: $var = '';

Or for all/older versions with isset:

$var = isset($var) ? $var : '';

!isset($var) && $var = '';

How to print a float with 2 decimal places in Java?

Many people have mentioned DecimalFormat. But you can also use printf if you have a recent version of Java:

System.out.printf("%1.2f", 3.14159D);

See the docs on the Formatter for more information about the printf format string.

Is there a way to take a screenshot using Java and save it to some sort of image?

GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();  
GraphicsDevice[] screens = ge.getScreenDevices();       
Rectangle allScreenBounds = new Rectangle();  
for (GraphicsDevice screen : screens) {  
       Rectangle screenBounds = screen.getDefaultConfiguration().getBounds();        
       allScreenBounds.width += screenBounds.width;  
       allScreenBounds.height = Math.max(allScreenBounds.height, screenBounds.height);
       allScreenBounds.x=Math.min(allScreenBounds.x, screenBounds.x);
       allScreenBounds.y=Math.min(allScreenBounds.y, screenBounds.y);
      } 
Robot robot = new Robot();
BufferedImage bufferedImage = robot.createScreenCapture(allScreenBounds);
File file = new File("C:\\Users\\Joe\\Desktop\\scr.png");
if(!file.exists())
    file.createNewFile();
FileOutputStream fos = new FileOutputStream(file);
ImageIO.write( bufferedImage, "png", fos );

bufferedImage will contain a full screenshot, this was tested with three monitors

Suppress Scientific Notation in Numpy When Creating Array From Nested List

I guess what you need is np.set_printoptions(suppress=True), for details see here: http://pythonquirks.blogspot.fr/2009/10/controlling-printing-in-numpy.html

For SciPy.org numpy documentation, which includes all function parameters (suppress isn't detailed in the above link), see here: https://docs.scipy.org/doc/numpy/reference/generated/numpy.set_printoptions.html

What to do with "Unexpected indent" in python?

If the indentation looks ok then have a look to see if your editor has a "View Whitespace" option. Enabling this should allow to find where spaces and tabs are mixed.

WooCommerce: Finding the products in database

I would recommend using WordPress custom fields to store eligible postcodes for each product. add_post_meta() and update_post_meta are what you're looking for. It's not recommended to alter the default WordPress table structure. All postmetas are inserted in wp_postmeta table. You can find the corresponding products within wp_posts table.

jquery get all input from specific form

The below code helps to get the details of elements from the specific form with the form id,

$('#formId input, #formId select').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

The below code helps to get the details of elements from all the forms which are place in the loading page,

$('form input, form select').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

The below code helps to get the details of elements which are place in the loading page even when the element is not place inside the tag,

$('input, select').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

NOTE: We add the more element tag name what we need in the object list like as below,

Example: to get name of attribute "textarea",

$('input, select, textarea').each(
    function(index){  
        var input = $(this);
        alert('Type: ' + input.attr('type') + 'Name: ' + input.attr('name') + 'Value: ' + input.val());
    }
);

What is the difference between the GNU Makefile variable assignments =, ?=, := and +=?

In the above answers, it is important to understand what is meant by "values are expanded at declaration/use time". Giving a value like *.c does not entail any expansion. It is only when this string is used by a command that it will maybe trigger some globbing. Similarly, a value like $(wildcard *.c) or $(shell ls *.c) does not entail any expansion and is completely evaluated at definition time even if we used := in the variable definition.

Try the following Makefile in directory where you have some C files:

VAR1 = *.c
VAR2 := *.c
VAR3 = $(wildcard *.c)
VAR4 := $(wildcard *.c)
VAR5 = $(shell ls *.c)
VAR6 := $(shell ls *.c)

all :
    touch foo.c
    @echo "now VAR1 = \"$(VAR1)\"" ; ls $(VAR1)
    @echo "now VAR2 = \"$(VAR2)\"" ; ls $(VAR2)
    @echo "now VAR3 = \"$(VAR3)\"" ; ls $(VAR3)
    @echo "now VAR4 = \"$(VAR4)\"" ; ls $(VAR4)
    @echo "now VAR5 = \"$(VAR5)\"" ; ls $(VAR5)
    @echo "now VAR6 = \"$(VAR6)\"" ; ls $(VAR6)
    rm -v foo.c

Running make will trigger a rule that creates an extra (empty) C file, called foo.c but none of the 6 variables has foo.c in its value.

how to change namespace of entire project?

When I wanted to change namespace and the solution name I did as follows:
1) changed the namespace by selecting it and renaming it and I did the same with solution name
2) clicked on the light bulb and renamed all the instances of old namespace
3) removed all the projects from the solution
4) closed the visual studio
5) renamed all the projects in windows explorer
6) opened visual studio and added all the projects again
7) rename namespaces in all projects in their properties
8) removed bin folder (from all projects)
9) build the project again

That worked for me without any problems and my project had as well source control. All was fine after pushing those changes to the remote.

How do I convert a PDF document to a preview image in PHP?

You can also get the page count using

$im->getNumberImages();

Then you can can create thumbs of all the pages using a loop, eg.

'file.pdf['.$x.']'

How do I configure PyCharm to run py.test tests?

Please go to File| Settings | Tools | Python Integrated Tools and change the default test runner to py.test. Then you'll get the py.test option to create tests instead of the unittest one.

jquery, find next element by class

To find the next element with the same class:

$(".class").eq( $(".class").index( $(element) ) + 1 )

Regular Expression to match every new line character (\n) inside a <content> tag

<content>(?:[^\n]*(\n+))+</content>

File Upload ASP.NET MVC 3.0

MemoryStream.GetBuffer() can return extra empty bytes at the end of the byte[], but you can fix that by using MemoryStream.ToArray() instead. However, I found this alternative to work perfectly for all file types:

using (var binaryReader = new BinaryReader(file.InputStream))
{
    byte[] array = binaryReader.ReadBytes(file.ContentLength);
}
Here's my full code:

Document Class:

public class Document
{
    public int? DocumentID { get; set; }
    public string FileName { get; set; }
    public byte[] Data { get; set; }
    public string ContentType { get; set; }
    public int? ContentLength { get; set; }

    public Document()
    {
        DocumentID = 0;
        FileName = "New File";
        Data = new byte[] { };
        ContentType = "";
        ContentLength = 0;
    }
}
File Download:

[HttpGet]
public ActionResult GetDocument(int? documentID)
{
    // Get document from database
    var doc = dataLayer.GetDocument(documentID);

    // Convert to ContentDisposition
    var cd = new System.Net.Mime.ContentDisposition
    {
        FileName = doc.FileName, 

        // Prompt the user for downloading; set to true if you want 
        // the browser to try to show the file 'inline' (display in-browser
        // without prompting to download file).  Set to false if you 
        // want to always prompt them to download the file.
        Inline = true, 
    };
    Response.AppendHeader("Content-Disposition", cd.ToString());

    // View document
    return File(doc.Data, doc.ContentType);
}
File Upload:

[HttpPost]
public ActionResult GetDocument(HttpPostedFileBase file)
{
    // Verify that the user selected a file
    if (file != null && file.ContentLength > 0)
    {
        // Get file info
        var fileName = Path.GetFileName(file.FileName);
        var contentLength = file.ContentLength;
        var contentType = file.ContentType;

        // Get file data
        byte[] data = new byte[] { };
        using (var binaryReader = new BinaryReader(file.InputStream))
        {
            data = binaryReader.ReadBytes(file.ContentLength);
        }

        // Save to database
        Document doc = new Document()
        {
            FileName = fileName,
            Data = data,
            ContentType = contentType,
            ContentLength = contentLength,
        };
        dataLayer.SaveDocument(doc);

        // Show success ...
        return RedirectToAction("Index");
    }
    else
    {
        // Show error ...
        return View("Foo");
    }
}
View (snippet):

@using (Html.BeginForm("GetDocument", "Home", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    <input type="file" name="file" />
    <input type="submit" value="Upload File" />
}

How to extract the decision rules from scikit-learn decision-tree?

Thank for the wonderful solution of @paulkerfeld. On top of his solution, for all those who want to have a serialized version of trees, just use tree.threshold, tree.children_left, tree.children_right, tree.feature and tree.value. Since the leaves don't have splits and hence no feature names and children, their placeholder in tree.feature and tree.children_*** are _tree.TREE_UNDEFINED and _tree.TREE_LEAF. Every split is assigned a unique index by depth first search.
Notice that the tree.value is of shape [n, 1, 1]

Inverse of matrix in R

Note that if you care about speed and do not need to worry about singularities, solve() should be preferred to ginv() because it is much faster, as you can check:

require(MASS)
mat <- matrix(rnorm(1e6),nrow=1e3,ncol=1e3)

t0 <- proc.time()
inv0 <- ginv(mat)
proc.time() - t0 

t1 <- proc.time()
inv1 <- solve(mat)
proc.time() - t1

Play audio from a stream using C#

Edit: Answer updated to reflect changes in recent versions of NAudio

It's possible using the NAudio open source .NET audio library I have written. It looks for an ACM codec on your PC to do the conversion. The Mp3FileReader supplied with NAudio currently expects to be able to reposition within the source stream (it builds an index of MP3 frames up front), so it is not appropriate for streaming over the network. However, you can still use the MP3Frame and AcmMp3FrameDecompressor classes in NAudio to decompress streamed MP3 on the fly.

I have posted an article on my blog explaining how to play back an MP3 stream using NAudio. Essentially you have one thread downloading MP3 frames, decompressing them and storing them in a BufferedWaveProvider. Another thread then plays back using the BufferedWaveProvider as an input.

Printing PDFs from Windows Command Line

Looks like you are missing the printer name, driver, and port - in that order. Your final command should resemble:

AcroRd32.exe /t <file.pdf> <printer_name> <printer_driver> <printer_port>

For example:

"C:\Program Files (x86)\Adobe\Reader 11.0\Reader\AcroRd32.exe" /t "C:\Folder\File.pdf" "Brother MFC-7820N USB Printer" "Brother MFC-7820N USB Printer" "IP_192.168.10.110"

Note: To find the printer information, right click your printer and choose properties. In my case shown above, the printer name and driver name matched - but your information may differ.

How do I get the last character of a string?

String aString = "This will return the letter t";
System.out.println(aString.charAt(aString.length() - 1));

Output should be:

Happy coding!

How do I build a Java project in Eclipse, to create an external JAR

.crx file install in chrome

Update: appears to have stopped working since Chrome 80

Drag & Drop the '.crx' file on to the 'Extensions' page

Settings - icon > Tools > Extensions
( the 'hamburger' icon in the top-right corner )

Enable Developer Mode ( toggle button in top-right corner )

Drag and drop the '.crx' extension file onto the Extensions page from step 1
( crx file should likely be in your Downloads directory )

Install

Source: Chrome YouTube Downloader - install instructions

How to create a numeric vector of zero length in R

Simply:

x <- vector(mode="numeric", length=0)

How do I convert a column of text URLs into active hyperlinks in Excel?

OK, here's a hokey solution, but I just can't figure out how to get Excel to evaluate a column of URLs as hyperlinks in bulk.

Create a formula, ="=hyperlink(""" & A1 & """)"
Drag down
Copy new formula column
Paste Special Values-only over the original column
Highlight column, click Ctrl-H (to replace), finding and replacing = with = (somehow forces re-evaluation of cells).
Cells should now be clickable as hyperlinks. If you want the blue/underline style, then just highlight all cells and choose the Hyperlink style.

The hyperlink style alone won't convert to clickable links, and the "Insert Hyperlink" dialog can't seem to use the text as the address for a bunch of cells in bulk. Aside from that, F2 and Enter through all cells would do it, but that's tedious for a lot of cells.

SQL Server NOLOCK and joins

I was pretty sure that you need to specify the NOLOCK for each JOIN in the query. But my experience was limited to SQL Server 2005.

When I looked up MSDN just to confirm, I couldn't find anything definite. The below statements do seem to make me think, that for 2008, your two statements above are equivalent though for 2005 it is not the case:

[SQL Server 2008 R2]

All lock hints are propagated to all the tables and views that are accessed by the query plan, including tables and views referenced in a view. Also, SQL Server performs the corresponding lock consistency checks.

[SQL Server 2005]

In SQL Server 2005, all lock hints are propagated to all the tables and views that are referenced in a view. Also, SQL Server performs the corresponding lock consistency checks.

Additionally, point to note - and this applies to both 2005 and 2008:

The table hints are ignored if the table is not accessed by the query plan. This may be caused by the optimizer choosing not to access the table at all, or because an indexed view is accessed instead. In the latter case, accessing an indexed view can be prevented by using the OPTION (EXPAND VIEWS) query hint.

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

A simplest fix would be:

x = input("Give starting number: ")
y = input("Give ending number: ")

x = int(x)  # parse string into an integer
y = int(y)  # parse string into an integer

for i in range(x,y):
    print(i)

input returns you a string (raw_input in Python 2). int tries to parse it into an integer. This code will throw an exception if the string doesn't contain a valid integer string, so you'd probably want to refine it a bit using try/except statements.

Calling a particular PHP function on form submit

Write this code

<?php
    if(isset($_POST['submit'])){
        echo 'Hello World';
    } 
?>

<html>
     <body>
         <form method="post">
             <input type="text" name="studentname">
             <input type="submit" name="submit" value="click">
         </form>
     </body>
</html>

showDialog deprecated. What's the alternative?

From Activity#showDialog(int):

This method is deprecated.
Use the new DialogFragment class with FragmentManager instead; this is also available on older platforms through the Android compatibility package.

Find closest previous element jQuery

var link = $("#me").closest(":has(h3 span b)").find('span b').text();

How to get rid of blank pages in PDF exported from SSRS

I've successfully used pdftk to remove pages I didn't want/need in pdfs. You can download the program here

You might try something like the following. Taken from here under examples

Remove 'page 13' from in1.pdf to create out1.pdf pdftk in.pdf cat 1-12 14-end output out1.pdf

or:

pdftk A=in1.pdf cat A1-12 A14-end output out1.pdf

Most efficient way to see if an ArrayList contains an object in Java

There are three basic options:

1) If retrieval performance is paramount and it is practical to do so, use a form of hash table built once (and altered as/if the List changes).

2) If the List is conveniently sorted or it is practical to sort it and O(log n) retrieval is sufficient, sort and search.

3) If O(n) retrieval is fast enough or if it is impractical to manipulate/maintain the data structure or an alternate, iterate over the List.

Before writing code more complex than a simple iteration over the List, it is worth thinking through some questions.

Why is something different needed? (Time) performance? Elegance? Maintainability? Reuse? All of these are okay reasons, apart or together, but they influence the solution.
How much control do you have over the data structure in question? Can you influence how it is built? Managed later?
What is the life cycle of the data structure (and underlying objects)? Is it built up all at once and never changed, or highly dynamic? Can your code monitor (or even alter) its life cycle?
Are there other important constraints, such as memory footprint? Does information about duplicates matter? Etc.

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)

Uncaught TypeError: Cannot read property 'toLowerCase' of undefined

When you call loadTeachers() on DOMReady the context of this will not be the #CourseSelect element.

You can fix this by triggering a change() event on the #CourseSelect element on load of the DOM:

$("#CourseSelect").change(loadTeachers).change(); // or .trigger('change');

Alternatively can use $.proxy to change the context the function runs under:

$("#CourseSelect").change(loadTeachers);
$.proxy(loadTeachers, $('#CourseSelect'))();

Or the vanilla JS equivalent of the above, bind():

$("#CourseSelect").change(loadTeachers);
loadTeachers.bind($('#CourseSelect'));

Twitter Bootstrap 3 Sticky Footer

If yout want to use bootstrap build in classes for the footer. You should also write some javascript:

$(document).ready(function(){
  $.fn.resize_footer();

  $(window).resize(function() {
    $.fn.resize_footer();
  });
 });

(function($) {

  $.fn.resize_footer = function(){
    $('body > .container-fluid').css('padding-bottom', $('body > footer').height());
  };
 });

It will prevent content overlapping by the fixed footer, and it will adjust the padding-bottom when the user changes the window/screen size.

In the script above I assumed that footer is placed directly inside the body tag like that:

<body>
  ... content of your page ...
  <div class="navbar navbar-default navbar-fixed-bottom">
    <div class="container">
      <div class="muted pull-right">
        Something useful
      </div>
      ... some other footer content ...
    </div>
  </div>
</body>

This is definitely not the best solution (because of the JS which could be avoided), but it works without any issues with overlapping, it is easy to implement and responsive (height is not hardcoded in CSS).

MySQL Workbench Edit Table Data is read only

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

For example, the following query

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

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

SELECT * FROM users WHERE id=1012;

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

String.Format like functionality in T-SQL?

I have created a user defined function to mimic the string.format functionality. You can use it.

stringformat-in-sql

UPDATE:
This version allows the user to change the delimitter.

-- DROP function will loose the security settings.
IF object_id('[dbo].[svfn_FormatString]') IS NOT NULL
    DROP FUNCTION [dbo].[svfn_FormatString]
GO

CREATE FUNCTION [dbo].[svfn_FormatString]
(
    @Format NVARCHAR(4000),
    @Parameters NVARCHAR(4000),
    @Delimiter CHAR(1) = ','
)
RETURNS NVARCHAR(MAX)
AS
BEGIN
    /*
        Name: [dbo].[svfn_FormatString]
        Creation Date: 12/18/2020

        Purpose: Returns the formatted string (Just like in C-Sharp)

        Input Parameters:   @Format         = The string to be Formatted
                            @Parameters     = The comma separated list of parameters
                            @Delimiter      = The delimitter to be used in the formatting process

        Format:             @Format         = N'Hi {0}, Welcome to our site {1}. Thank you {0}'
                            @Parameters     = N'Karthik,google.com'
                            @Delimiter      = ','           
        Examples:
            SELECT dbo.svfn_FormatString(N'Hi {0}, Welcome to our site {1}. Thank you {0}', N'Karthik,google.com', default)
            SELECT dbo.svfn_FormatString(N'Hi {0}, Welcome to our site {1}. Thank you {0}', N'Karthik;google.com', ';')
    */
    DECLARE @Message NVARCHAR(400)
    DECLARE @ParamTable TABLE ( Id INT IDENTITY(0,1), Paramter VARCHAR(1000))

    SELECT @Message = @Format

    ;WITH CTE (StartPos, EndPos) AS
    (
        SELECT 1, CHARINDEX(@Delimiter, @Parameters)
        UNION ALL
        SELECT EndPos + (LEN(@Delimiter)), CHARINDEX(@Delimiter, @Parameters, EndPos + (LEN(@Delimiter)))
        FROM CTE
        WHERE EndPos > 0
    )

    INSERT INTO @ParamTable ( Paramter )
    SELECT
        [Id] = SUBSTRING(@Parameters, StartPos, CASE WHEN EndPos > 0 THEN EndPos - StartPos ELSE 4000 END )
    FROM CTE

    UPDATE @ParamTable 
    SET 
        @Message = REPLACE(@Message, '{'+ CONVERT(VARCHAR, Id) + '}', Paramter )

    RETURN @Message
END

How does the keyword "use" work in PHP and can I import classes with it?

Using the keyword "use" is for shortening namespace literals. You can use both with aliasing and without it. Without aliasing you must use last part of full namespace.

<?php
    use foo\bar\lastPart;
    $obj=new lastPart\AnyClass(); //If there's not the line above, a fatal error will be encountered.
?>

using javascript to detect whether the url exists before display in iframe

I created this method, it is ideal because it aborts the connection without downloading it in its entirety, ideal for checking if videos or large images exist, decreasing the response time and the need to download the entire file

// if-url-exist.js v1
function ifUrlExist(url, callback) {
    let request = new XMLHttpRequest;
    request.open('GET', url, true);
    request.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8');
    request.setRequestHeader('Accept', '*/*');
    request.onprogress = function(event) {
        let status = event.target.status;
        let statusFirstNumber = (status).toString()[0];
        switch (statusFirstNumber) {
            case '2':
                request.abort();
                return callback(true);
            default:
                request.abort();
                return callback(false);
        };
    };
    request.send('');
};

Example of use:

ifUrlExist(url, function(exists) {
    console.log(exists);
});

How to make div go behind another div?

One possible could be like this,

HTML

<div class="box-left-mini">
    <div class="front">this div is infront</div>
    <div class="behind">
        this div is behind
    </div>
</div>

CSS

.box-left-mini{
float:left;
background-image:url(website-content/hotcampaign.png);
width:292px;
height:141px;
}
.front{
    background-color:lightgreen;
}
.behind{
    background-color:grey;
    position:absolute;
    width:100%;
    height:100%;
    top:0;
    z-index:-1;
}

http://jsfiddle.net/MgtWS/

But it really depends on the layout of your div elements i.e. if they are floating, or absolute positioned etc.

Nexus 7 (2013) and Win 7 64 - cannot install USB driver despite checking many forums and online resources

Depending on the device, sometimes you are getting "The folder you specified doesn't contain a compatible software" error because the first interface isn't actually the ADB interface.

Try installing it as a generic "USB composite device" instead (from the 'pick from a list' driver install option); once the standard composite driver installs it will allow Windows to communicate with the device and detect the associated ADB driver interface and install it properly.

Laravel back button

Laravel 5.2+, back button

<a href="{{ url()->previous() }}" class="btn btn-default">Back</a>

Ajax success function

It is because Ajax is asynchronous, the success or the error function will be called later, when the server answer the client. So, just move parts depending on the result into your success function like that :

jQuery.ajax({

            type:"post",
            dataType:"json",
            url: myAjax.ajaxurl,
            data: {action: 'submit_data', info: info},
            success: function(data) {
                successmessage = 'Data was succesfully captured';
                $("label#successmessage").text(successmessage);
            },
            error: function(data) {
                successmessage = 'Error';
                $("label#successmessage").text(successmessage);
            },
        });

        $(":input").val('');
        return false;

Does the 'mutable' keyword have any purpose other than allowing the variable to be modified by a const function?

It's useful in situations where you have hidden internal state such as a cache. For example:

class HashTable
{
...
public:
    string lookup(string key) const
    {
        if(key == lastKey)
            return lastValue;

        string value = lookupInternal(key);

        lastKey = key;
        lastValue = value;

        return value;
    }

private:
    mutable string lastKey, lastValue;
};

And then you can have a const HashTable object still use its lookup() method, which modifies the internal cache.

Vuejs: Event on route change

Another solution for typescript user:

import Vue from "vue";
import Component from "vue-class-component";

@Component({
  beforeRouteLeave(to, from, next) {
    // incase if you want to access `this`
    // const self = this as any;
    next();
  }
})

export default class ComponentName extends Vue {}

Concatenating multiple text files into a single file in Bash

You can do like this: cat [directory_path]/**/*.[h,m] > test.txt

if you use {} to include the extension of the files you want to find, there is a sequencing problem.

Save text file UTF-8 encoded with VBA

Here is another way to do this - using the API function WideCharToMultiByte:

Option Explicit

Private Declare Function WideCharToMultiByte Lib "kernel32.dll" ( _
  ByVal CodePage As Long, _
  ByVal dwFlags As Long, _
  ByVal lpWideCharStr As Long, _
  ByVal cchWideChar As Long, _
  ByVal lpMultiByteStr As Long, _
  ByVal cbMultiByte As Long, _
  ByVal lpDefaultChar As Long, _
  ByVal lpUsedDefaultChar As Long) As Long

Private Sub getUtf8(ByRef s As String, ByRef b() As Byte)
Const CP_UTF8 As Long = 65001
Dim len_s As Long
Dim ptr_s As Long
Dim size As Long
  Erase b
  len_s = Len(s)
  If len_s = 0 Then _
    Err.Raise 30030, , "Len(WideChars) = 0"
  ptr_s = StrPtr(s)
  size = WideCharToMultiByte(CP_UTF8, 0, ptr_s, len_s, 0, 0, 0, 0)
  If size = 0 Then _
    Err.Raise 30030, , "WideCharToMultiByte() = 0"
  ReDim b(0 To size - 1)
  If WideCharToMultiByte(CP_UTF8, 0, ptr_s, len_s, VarPtr(b(0)), size, 0, 0) = 0 Then _
    Err.Raise 30030, , "WideCharToMultiByte(" & Format$(size) & ") = 0"
End Sub

Public Sub writeUtf()
Dim file As Integer
Dim s As String
Dim b() As Byte
  s = "äöüßµ@€|~{}[]²³\ .." & _
    " OMEGA" & ChrW$(937) & ", SIGMA" & ChrW$(931) & _
    ", alpha" & ChrW$(945) & ", beta" & ChrW$(946) & ", pi" & ChrW$(960) & vbCrLf
  file = FreeFile
  Open "C:\Temp\TestUtf8.txt" For Binary Access Write Lock Read Write As #file
  getUtf8 s, b
  Put #file, , b
  Close #file
End Sub

How to disable HTML button using JavaScript?

It is an attribute, but a boolean one (so it doesn't need a name, just a value -- I know, it's weird). You can set the property equivalent in Javascript:

document.getElementsByName("myButton")[0].disabled = true;

How to calculate the bounding box for a given lat/lng location?

Thanks @Fedrico A. for the Phyton implementation, I have ported it into a Objective C category class. Here is:

#import "LocationService+Bounds.h"

//Semi-axes of WGS-84 geoidal reference
const double WGS84_a = 6378137.0; //Major semiaxis [m]
const double WGS84_b = 6356752.3; //Minor semiaxis [m]

@implementation LocationService (Bounds)

struct BoundsLocation {
    double maxLatitude;
    double minLatitude;
    double maxLongitude;
    double minLongitude;
};

+ (struct BoundsLocation)locationBoundsWithLatitude:(double)aLatitude longitude:(double)aLongitude maxDistanceKm:(NSInteger)aMaxKmDistance {
    return [self boundingBoxWithLatitude:aLatitude longitude:aLongitude halfDistanceKm:aMaxKmDistance/2];
}

#pragma mark - Algorithm 

+ (struct BoundsLocation)boundingBoxWithLatitude:(double)aLatitude longitude:(double)aLongitude halfDistanceKm:(double)aDistanceKm {
    double radianLatitude = [self degreesToRadians:aLatitude];
    double radianLongitude = [self degreesToRadians:aLongitude];
    double halfDistanceMeters = aDistanceKm*1000;


    double earthRadius = [self earthRadiusAtLatitude:radianLatitude];
    double parallelRadius = earthRadius*cosl(radianLatitude);

    double radianMinLatitude = radianLatitude - halfDistanceMeters/earthRadius;
    double radianMaxLatitude = radianLatitude + halfDistanceMeters/earthRadius;
    double radianMinLongitude = radianLongitude - halfDistanceMeters/parallelRadius;
    double radianMaxLongitude = radianLongitude + halfDistanceMeters/parallelRadius;

    struct BoundsLocation bounds;
    bounds.minLatitude = [self radiansToDegrees:radianMinLatitude];
    bounds.maxLatitude = [self radiansToDegrees:radianMaxLatitude];
    bounds.minLongitude = [self radiansToDegrees:radianMinLongitude];
    bounds.maxLongitude = [self radiansToDegrees:radianMaxLongitude];

    return bounds;
}

+ (double)earthRadiusAtLatitude:(double)aRadianLatitude {
    double An = WGS84_a * WGS84_a * cosl(aRadianLatitude);
    double Bn = WGS84_b * WGS84_b * sinl(aRadianLatitude);
    double Ad = WGS84_a * cosl(aRadianLatitude);
    double Bd = WGS84_b * sinl(aRadianLatitude);
    return sqrtl( ((An * An) + (Bn * Bn))/((Ad * Ad) + (Bd * Bd)) );
}

+ (double)degreesToRadians:(double)aDegrees {
    return M_PI*aDegrees/180.0;
}

+ (double)radiansToDegrees:(double)aRadians {
    return 180.0*aRadians/M_PI;
}



@end

I have tested it and seems be working nice. Struct BoundsLocation should be replaced by a class, I have used it just to share it here.

Initializing IEnumerable<string> In C#

IEnumerable is an interface, instead of looking for how to create an interface instance, create an implementation that matches the interface: create a list or an array.

IEnumerable<string> myStrings = new [] { "first item", "second item" };
IEnumerable<string> myStrings = new List<string> { "first item", "second item" };

Angular2 change detection: ngOnChanges not firing for nested object

suppose you have a nested object, like

var obj = {"parent": {"child": {....}}}

If you passed the reference of the complete object, like

[wholeObj] = "obj"

In that case, you can't detect the changes in the child objects, so to overcome this problem you can also pass the reference of the child object through another property, like

[wholeObj] = "obj" [childObj] = "obj.parent.child"

So you can also detect the changes from the child objects too.

ngOnChanges(changes: SimpleChanges) { 
    if (changes.childObj) {// your logic here}
}

Write a file in UTF-8 using FileWriter (Java)?

You need to use the OutputStreamWriter class as the writer parameter for your BufferedWriter. It does accept an encoding. Review javadocs for it.

Somewhat like this:

BufferedWriter out = new BufferedWriter(new OutputStreamWriter(
    new FileOutputStream("jedis.txt"), "UTF-8"
));

Or you can set the current system encoding with the system property file.encoding to UTF-8.

java -Dfile.encoding=UTF-8 com.jediacademy.Runner arg1 arg2 ...

You may also set it as a system property at runtime with System.setProperty(...) if you only need it for this specific file, but in a case like this I think I would prefer the OutputStreamWriter.

By setting the system property you can use FileWriter and expect that it will use UTF-8 as the default encoding for your files. In this case for all the files that you read and write.

EDIT

Starting from API 19, you can replace the String "UTF-8" with StandardCharsets.UTF_8

As suggested in the comments below by tchrist, if you intend to detect encoding errors in your file you would be forced to use the OutputStreamWriter approach and use the constructor that receives a charset encoder.

Somewhat like

CharsetEncoder encoder = Charset.forName("UTF-8").newEncoder();
encoder.onMalformedInput(CodingErrorAction.REPORT);
encoder.onUnmappableCharacter(CodingErrorAction.REPORT);
BufferedWriter out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("jedis.txt"),encoder));

You may choose between actions IGNORE | REPLACE | REPORT

Also, this question was already answered here.

How to access session variables from any class in ASP.NET?

(Updated for completeness)
You can access session variables from any page or control using Session["loginId"] and from any class (e.g. from inside a class library), using System.Web.HttpContext.Current.Session["loginId"].

But please read on for my original answer...

I always use a wrapper class around the ASP.NET session to simplify access to session variables:

public class MySession
{
    // private constructor
    private MySession()
    {
      Property1 = "default value";
    }

    // Gets the current session.
    public static MySession Current
    {
      get
      {
        MySession session =
          (MySession)HttpContext.Current.Session["__MySession__"];
        if (session == null)
        {
          session = new MySession();
          HttpContext.Current.Session["__MySession__"] = session;
        }
        return session;
      }
    }

    // **** add your session properties here, e.g like this:
    public string Property1 { get; set; }
    public DateTime MyDate { get; set; }
    public int LoginId { get; set; }
}

This class stores one instance of itself in the ASP.NET session and allows you to access your session properties in a type-safe way from any class, e.g like this:

int loginId = MySession.Current.LoginId;

string property1 = MySession.Current.Property1;
MySession.Current.Property1 = newValue;

DateTime myDate = MySession.Current.MyDate;
MySession.Current.MyDate = DateTime.Now;

This approach has several advantages:

it saves you from a lot of type-casting
you don't have to use hard-coded session keys throughout your application (e.g. Session["loginId"]
you can document your session items by adding XML doc comments on the properties of MySession
you can initialize your session variables with default values (e.g. assuring they are not null)

Fastest way to check if a string matches a regexp in ruby?

Depending on how complicated your regular expression is, you could possibly just use simple string slicing. I'm not sure about the practicality of this for your application or whether or not it would actually offer any speed improvements.

'testsentence'['stsen']
=> 'stsen' # evaluates to true
'testsentence'['koala']
=> nil # evaluates to false

foreach loop in angularjs

Change the line into this

 angular.forEach(values, function(value, key){
   console.log(key + ': ' + value);
 });

 angular.forEach(values, function(value, key){
   console.log(key + ': ' + value.Name);
 });

How do I clear a C++ array?

Hey i think The fastest way to handle that kind of operation is to memset() the memory.

Example-

memset(&myPage.pageArray[0][0], 0, sizeof(myPage.pageArray));

A similar C++ way would be to use std::fill

char *begin = myPage.pageArray[0][0];
char *end = begin + sizeof(myPage.pageArray);
std::fill(begin, end, 0);

Determine what attributes were changed in Rails after_save callback?

For those who want to know the changes just made in an after_save callback:

Rails 5.1 and greater

model.saved_changes

Rails < 5.1

model.previous_changes

Also see: http://api.rubyonrails.org/classes/ActiveModel/Dirty.html#method-i-previous_changes

Upgrade version of Pandas

According to an article on Medium, this will work:

install --upgrade pandas==1.0.0rc0

Pandas: Convert Timestamp to datetime.date

Assume time column is in timestamp integer msec format

1 day = 86400000 ms

Here you go:

day_divider = 86400000

df['time'] = df['time'].values.astype(dtype='datetime64[ms]') # for msec format

df['time'] = (df['time']/day_divider).values.astype(dtype='datetime64[D]') # for day format

Room persistance library. Delete all

To make use of the Room without abuse of the @Query annotation first use @Query to select all rows and put them in a list, for example:

@Query("SELECT * FROM your_class_table")

List`<`your_class`>` load_all_your_class();

Put his list into the delete annotation, for example:

@Delete

void deleteAllOfYourTable(List`<`your_class`>` your_class_list);

AngularJS: Basic example to use authentication in Single Page Application

_x000D_

var _login = function (loginData) {_x000D_
 _x000D_
        var data = "grant_type=password&username=" + loginData.userName + "&password=" + loginData.password;_x000D_
 _x000D_
        var deferred = $q.defer();_x000D_
 _x000D_
        $http.post(serviceBase + 'token', data, { headers: { 'Content-Type': 'application/x-www-form-urlencoded' } }).success(function (response) {_x000D_
 _x000D_
            localStorageService.set('authorizationData', { token: response.access_token, userName: loginData.userName });_x000D_
 _x000D_
            _authentication.isAuth = true;_x000D_
            _authentication.userName = loginData.userName;_x000D_
 _x000D_
            deferred.resolve(response);_x000D_
 _x000D_
        }).error(function (err, status) {_x000D_
            _logOut();_x000D_
            deferred.reject(err);_x000D_
        });_x000D_
 _x000D_
        return deferred.promise;_x000D_
 _x000D_
    };_x000D_

_x000D_

IllegalArgumentException or NullPointerException for a null parameter?

It's a "Holy War" style question. In others words, both alternatives are good, but people will have their preferences which they will defend to the death.

How to correctly display .csv files within Excel 2013?

For Excel 2013:

Open Blank Workbook.
Go to DATA tab.
Click button From Text in the General External Data section.
Select your CSV file.
Follow the Text Import Wizard. (in step 2, select the delimiter of your text)

http://blogmines.com/blog/how-to-import-text-file-in-excel-2013/

grep using a character vector with multiple patterns

Have you tried the match() or charmatch() functions?

Example use:

match(c("A1", "A9", "A6"), myfile$Letter)

Store a cmdlet's result value in a variable in Powershell

Just access the Priority property of the object returned from the pipeline:

$var = (Get-WSManInstance -enumerate wmicimv2/win32_process).Priority

(This won't work if Get-WSManInstance returns multiple objects.²)

For the second question: to get two properties there are several options, problably the simplest is to have have one variable* containing an object with two separate properties:

$var = (Get-WSManInstance -enumerate wmicimv2/win32_process | select -first 1 Priority, ProcessID)

and then use, assuming only one process:

$var.Priority

and

$var.ProcessID

If there are multiple processes $var will be an array which you can index, so to get the properties of the first process (using the array literal syntax @(...) so it is always a collection¹):

$var = @(Get-WSManInstance -enumerate wmicimv2/win32_process | select -first 1 Priority, ProcessID)

and then use:

$var[0].Priority
$var[0].ProcessID

¹ PowerShell helpfully for the command line, but not so helpfully in scripts has some extra logic when assigning the result of a pipeline to a variable: if no objects are returned then set $null, if one is returned then that object is assigned, otherwise an array is assigned. Forcing an array returns an array with zero, one or more (respectively) elements.

² This changes in PowerShell V3 (at the time of writing in Release Candidate), using a member property on an array of objects will return an array of the value of those properties.

How do you perform a left outer join using linq extension methods

Group Join method is unnecessary to achieve joining of two data sets.

Inner Join:

var qry = Foos.SelectMany
            (
                foo => Bars.Where (bar => foo.Foo_id == bar.Foo_id),
                (foo, bar) => new
                    {
                    Foo = foo,
                    Bar = bar
                    }
            );

For Left Join just add DefaultIfEmpty()

var qry = Foos.SelectMany
            (
                foo => Bars.Where (bar => foo.Foo_id == bar.Foo_id).DefaultIfEmpty(),
                (foo, bar) => new
                    {
                    Foo = foo,
                    Bar = bar
                    }
            );

EF and LINQ to SQL correctly transform to SQL. For LINQ to Objects it is beter to join using GroupJoin as it internally uses Lookup. But if you are querying DB then skipping of GroupJoin is AFAIK as performant.

Personlay for me this way is more readable compared to GroupJoin().SelectMany()

How to add column if not exists on PostgreSQL?

With Postgres 9.6 this can be done using the option if not exists

ALTER TABLE table_name ADD COLUMN IF NOT EXISTS column_name INTEGER;

Select data between a date/time range

You must search date defend on how you insert that game_date data on your database.. for example if you inserted date value on long date or short.

SELECT * FROM hockey_stats WHERE game_date >= "6/11/2018" AND game_date <= "6/17/2018"

You can also use BETWEEN:

SELECT * FROM hockey_stats WHERE game_date BETWEEN "6/11/2018" AND "6/17/2018"

simple as that.

Determine Pixel Length of String in Javascript/jQuery?

The contexts used for HTML Canvases have a built-in method for checking the size of a font. This method returns a TextMetrics object, which has a width property that contains the width of the text.

function getWidthOfText(txt, fontname, fontsize){
    if(getWidthOfText.c === undefined){
        getWidthOfText.c=document.createElement('canvas');
        getWidthOfText.ctx=getWidthOfText.c.getContext('2d');
    }
    var fontspec = fontsize + ' ' + fontname;
    if(getWidthOfText.ctx.font !== fontspec)
        getWidthOfText.ctx.font = fontspec;
    return getWidthOfText.ctx.measureText(txt).width;
}

Or, as some of the other users have suggested, you can wrap it in a span element:

function getWidthOfText(txt, fontname, fontsize){
    if(getWidthOfText.e === undefined){
        getWidthOfText.e = document.createElement('span');
        getWidthOfText.e.style.display = "none";
        document.body.appendChild(getWidthOfText.e);
    }
    if(getWidthOfText.e.style.fontSize !== fontsize)
        getWidthOfText.e.style.fontSize = fontsize;
    if(getWidthOfText.e.style.fontFamily !== fontname)
        getWidthOfText.e.style.fontFamily = fontname;
    getWidthOfText.e.innerText = txt;
    return getWidthOfText.e.offsetWidth;
}

EDIT 2020: added font name+size caching at Igor Okorokov's suggestion.

How do I install boto?

If you already have boto installed in one python version and then install a higher python version, boto is not found by the new version of python.

For example, I had python2.7 and then installed python3.5 (keeping both). My script under python3.5 could not find boto. Doing "pip install boto" told me that boto was already installed in /usr/lib/python2.7/dist-packages.

So I did

pip install --target /usr/lib/python3.5/dist-packages boto

This allowed my script under python3.5 to find boto.

Send HTTP POST message in ASP.NET Core using HttpClient PostAsJsonAsync

Microsoft now recommends using an IHttpClientFactory with the following benefits:

Provides a central location for naming and configuring logical HttpClient instances. For example, a client named github could be registered and configured to access GitHub. A default client can be registered for general access.
Codifies the concept of outgoing middleware via delegating handlers in HttpClient. Provides extensions for Polly-based middleware to take advantage of delegating handlers in HttpClient.
Manages the pooling and lifetime of underlying HttpClientMessageHandler instances. Automatic management avoids common DNS (Domain Name System) problems that occur when manually managing HttpClient lifetimes.
Adds a configurable logging experience (via ILogger) for all requests sent through clients created by the factory.

https://docs.microsoft.com/en-us/aspnet/core/fundamentals/http-requests?view=aspnetcore-3.1

Setup:

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddHttpClient();
        // Remaining code deleted for brevity.

POST example:

public class BasicUsageModel : PageModel
{
    private readonly IHttpClientFactory _clientFactory;

    public BasicUsageModel(IHttpClientFactory clientFactory)
    {
        _clientFactory = clientFactory;
    }
    
    public async Task CreateItemAsync(TodoItem todoItem)
    {
        var todoItemJson = new StringContent(
            JsonSerializer.Serialize(todoItem, _jsonSerializerOptions),
            Encoding.UTF8,
            "application/json");
            
        var httpClient = _clientFactory.CreateClient();
        
        using var httpResponse =
            await httpClient.PostAsync("/api/TodoItems", todoItemJson);
    
        httpResponse.EnsureSuccessStatusCode();
    }

https://docs.microsoft.com/en-us/aspnet/core/fundamentals/http-requests?view=aspnetcore-3.1#make-post-put-and-delete-requests

What does upstream mean in nginx?

If we have a single server we can directly include it in the proxy_pass. But in case if we have many servers we use upstream to maintain the servers. Nginx will load-balance based on the incoming traffic.

What are the git concepts of HEAD, master, origin?

HEAD is not the latest revision, it's the current revision. Usually, it's the latest revision of the current branch, but it doesn't have to be.

master is a name commonly given to the main branch, but it could be called anything else (or there could be no main branch).

origin is a name commonly given to the main remote. remote is another repository that you can pull from and push to. Usually it's on some server, like github.

Spring boot - Not a managed type

Faced similar issue. In my case the repository and the type being managed where not in same package.

Best XML Parser for PHP

It depends on what you are trying to do with the XML files. If you are just trying to read the XML file (like a configuration file), The Wicked Flea is correct in suggesting SimpleXML since it creates what amounts to nested ArrayObjects. e.g. value will be accessible by $xml->root->child.

If you are looking to manipulate the XML files you're probably best off using DOM XML

Restore a deleted file in the Visual Studio Code Recycle Bin

It uses the normal trash bin of your system. So you can grab it our of there.

In Windows you find it in the explorer, in Linux it is as well in Konquerer / Nemo / ...

Total width of element (including padding and border) in jQuery

Just for simplicity I encapsulated Andreas Grech's great answer above in some functions. For those who want a bit of cut-and-paste happiness.

function getTotalWidthOfObject(object) {

    if(object == null || object.length == 0) {
        return 0;
    }

    var value       = object.width();
    value           += parseInt(object.css("padding-left"), 10) + parseInt(object.css("padding-right"), 10); //Total Padding Width
    value           += parseInt(object.css("margin-left"), 10) + parseInt(object.css("margin-right"), 10); //Total Margin Width
    value           += parseInt(object.css("borderLeftWidth"), 10) + parseInt(object.css("borderRightWidth"), 10); //Total Border Width
    return value;
}

function  getTotalHeightOfObject(object) {

    if(object == null || object.length == 0) {
        return 0;
    }

    var value       = object.height();
    value           += parseInt(object.css("padding-top"), 10) + parseInt(object.css("padding-bottom"), 10); //Total Padding Width
    value           += parseInt(object.css("margin-top"), 10) + parseInt(object.css("margin-bottom"), 10); //Total Margin Width
    value           += parseInt(object.css("borderTopWidth"), 10) + parseInt(object.css("borderBottomWidth"), 10); //Total Border Width
    return value;
}

var self = this?

var functionX = function() {
  var self = this;
  var functionY = function(y) {
    // If we call "this" in here, we get a reference to functionY,
    // but if we call "self" (defined earlier), we get a reference to function X.
  }
}

edit: in spite of, nested functions within an object takes on the global window object rather than the surrounding object.

Android MediaPlayer Stop and Play

I may have not got your answer correct, but you can try this:

public void MusicController(View view) throws IOException{
    switch (view.getId()){
        case R.id.play: mplayer.start();break;
        case R.id.pause: mplayer.pause(); break;
        case R.id.stop:
            if(mplayer.isPlaying()) {
                mplayer.stop();
                mplayer.prepare(); 
            }
            break;

    }// where mplayer is defined in  onCreate method}

as there is just one thread handling all, so stop() makes it die so we have to again prepare it If your intent is to start it again when your press start button(it throws IO Exception) Or for better understanding of MediaPlayer you can refer to Android Media Player

AssertNull should be used or AssertNotNull

I just want to add that if you want to write special text if It null than you make it like that

  Assert.assertNotNull("The object you enter return null", str1)

How can I set my Cygwin PATH to find javac?

as you write the it with double-quotes, you don't need to escape spaces with \

export PATH=$PATH:"/cygdrive/C/Program Files/Java/jdk1.6.0_23/bin/"

of course this also works:

export PATH=$PATH:/cygdrive/C/Program\ Files/Java/jdk1.6.0_23/bin/

bootstrap datepicker change date event doesnt fire up when manually editing dates or clearing date

In version 2.1.5

bootstrap-datetimepicker.js
http://www.eyecon.ro/bootstrap-datepicker
Contributions:
Andrew Rowls
Thiago de Arruda
updated for Bootstrap v3 by Jonathan Peterson @Eonasdan

changeDate has been renamed to change.dp so changedate was not working for me

$("#datetimepicker").datetimepicker().on('change.dp', function (e) {
            FillDate(new Date());
    });

also needed to change css class from datepicker to datepicker-input

<div id='datetimepicker' class='datepicker-input input-group controls'>
   <input id='txtStartDate' class='form-control' placeholder='Select datepicker' data-rule-required='true' data-format='MM-DD-YYYY' type='text' />
   <span class='input-group-addon'>
       <span class='icon-calendar' data-time-icon='icon-time' data-date-icon='icon-calendar'></span>
   </span>
</div>

Date formate also works in capitals like this data-format='MM-DD-YYYY'

it might be helpful for someone it gave me really hard time :)

turn typescript object into json string

You can use the standard JSON object, available in Javascript:

var a: any = {};
a.x = 10;
a.y='hello';
var jsonString = JSON.stringify(a);

Convert all strings in a list to int

Use a list comprehension:

results = [int(i) for i in results]

e.g.

>>> results = ["1", "2", "3"]
>>> results = [int(i) for i in results]
>>> results
[1, 2, 3]

Serializing/deserializing with memory stream

This code works for me:

public void Run()
{
    Dog myDog = new Dog();
    myDog.Name= "Foo";
    myDog.Color = DogColor.Brown;

    System.Console.WriteLine("{0}", myDog.ToString());

    MemoryStream stream = SerializeToStream(myDog);

    Dog newDog = (Dog)DeserializeFromStream(stream);

    System.Console.WriteLine("{0}", newDog.ToString());
}

Where the types are like this:

[Serializable]
public enum DogColor
{
    Brown,
    Black,
    Mottled
}

[Serializable]
public class Dog
{
    public String Name
    {
        get; set;
    }

    public DogColor Color
    {
        get;set;
    }

    public override String ToString()
    {
        return String.Format("Dog: {0}/{1}", Name, Color);
    }
}

and the utility methods are:

public static MemoryStream SerializeToStream(object o)
{
    MemoryStream stream = new MemoryStream();
    IFormatter formatter = new BinaryFormatter();
    formatter.Serialize(stream, o);
    return stream;
}

public static object DeserializeFromStream(MemoryStream stream)
{
    IFormatter formatter = new BinaryFormatter();
    stream.Seek(0, SeekOrigin.Begin);
    object o = formatter.Deserialize(stream);
    return o;
}

Fast Bitmap Blur For Android SDK

For future Googlers, here is an algorithm that I ported from Quasimondo. It's kind of a mix between a box blur and a gaussian blur, it's very pretty and quite fast too.

Update for people encountering the ArrayIndexOutOfBoundsException problem : @anthonycr in the comments provides this information :

I found that by replacing Math.abs with StrictMath.abs or some other abs implementation, the crash does not occur.

/**
 * Stack Blur v1.0 from
 * http://www.quasimondo.com/StackBlurForCanvas/StackBlurDemo.html
 * Java Author: Mario Klingemann <mario at quasimondo.com>
 * http://incubator.quasimondo.com
 *
 * created Feburary 29, 2004
 * Android port : Yahel Bouaziz <yahel at kayenko.com>
 * http://www.kayenko.com
 * ported april 5th, 2012
 *
 * This is a compromise between Gaussian Blur and Box blur
 * It creates much better looking blurs than Box Blur, but is
 * 7x faster than my Gaussian Blur implementation.
 *
 * I called it Stack Blur because this describes best how this
 * filter works internally: it creates a kind of moving stack
 * of colors whilst scanning through the image. Thereby it
 * just has to add one new block of color to the right side
 * of the stack and remove the leftmost color. The remaining
 * colors on the topmost layer of the stack are either added on
 * or reduced by one, depending on if they are on the right or
 * on the left side of the stack.
 *  
 * If you are using this algorithm in your code please add
 * the following line:
 * Stack Blur Algorithm by Mario Klingemann <[email protected]>
 */

public Bitmap fastblur(Bitmap sentBitmap, float scale, int radius) {

    int width = Math.round(sentBitmap.getWidth() * scale);
    int height = Math.round(sentBitmap.getHeight() * scale);
    sentBitmap = Bitmap.createScaledBitmap(sentBitmap, width, height, false);

    Bitmap bitmap = sentBitmap.copy(sentBitmap.getConfig(), true);

    if (radius < 1) {
        return (null);
    }

    int w = bitmap.getWidth();
    int h = bitmap.getHeight();

    int[] pix = new int[w * h];
    Log.e("pix", w + " " + h + " " + pix.length);
    bitmap.getPixels(pix, 0, w, 0, 0, w, h);

    int wm = w - 1;
    int hm = h - 1;
    int wh = w * h;
    int div = radius + radius + 1;

    int r[] = new int[wh];
    int g[] = new int[wh];
    int b[] = new int[wh];
    int rsum, gsum, bsum, x, y, i, p, yp, yi, yw;
    int vmin[] = new int[Math.max(w, h)];

    int divsum = (div + 1) >> 1;
    divsum *= divsum;
    int dv[] = new int[256 * divsum];
    for (i = 0; i < 256 * divsum; i++) {
        dv[i] = (i / divsum);
    }

    yw = yi = 0;

    int[][] stack = new int[div][3];
    int stackpointer;
    int stackstart;
    int[] sir;
    int rbs;
    int r1 = radius + 1;
    int routsum, goutsum, boutsum;
    int rinsum, ginsum, binsum;

    for (y = 0; y < h; y++) {
        rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
        for (i = -radius; i <= radius; i++) {
            p = pix[yi + Math.min(wm, Math.max(i, 0))];
            sir = stack[i + radius];
            sir[0] = (p & 0xff0000) >> 16;
            sir[1] = (p & 0x00ff00) >> 8;
            sir[2] = (p & 0x0000ff);
            rbs = r1 - Math.abs(i);
            rsum += sir[0] * rbs;
            gsum += sir[1] * rbs;
            bsum += sir[2] * rbs;
            if (i > 0) {
                rinsum += sir[0];
                ginsum += sir[1];
                binsum += sir[2];
            } else {
                routsum += sir[0];
                goutsum += sir[1];
                boutsum += sir[2];
            }
        }
        stackpointer = radius;

        for (x = 0; x < w; x++) {

            r[yi] = dv[rsum];
            g[yi] = dv[gsum];
            b[yi] = dv[bsum];

            rsum -= routsum;
            gsum -= goutsum;
            bsum -= boutsum;

            stackstart = stackpointer - radius + div;
            sir = stack[stackstart % div];

            routsum -= sir[0];
            goutsum -= sir[1];
            boutsum -= sir[2];

            if (y == 0) {
                vmin[x] = Math.min(x + radius + 1, wm);
            }
            p = pix[yw + vmin[x]];

            sir[0] = (p & 0xff0000) >> 16;
            sir[1] = (p & 0x00ff00) >> 8;
            sir[2] = (p & 0x0000ff);

            rinsum += sir[0];
            ginsum += sir[1];
            binsum += sir[2];

            rsum += rinsum;
            gsum += ginsum;
            bsum += binsum;

            stackpointer = (stackpointer + 1) % div;
            sir = stack[(stackpointer) % div];

            routsum += sir[0];
            goutsum += sir[1];
            boutsum += sir[2];

            rinsum -= sir[0];
            ginsum -= sir[1];
            binsum -= sir[2];

            yi++;
        }
        yw += w;
    }
    for (x = 0; x < w; x++) {
        rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
        yp = -radius * w;
        for (i = -radius; i <= radius; i++) {
            yi = Math.max(0, yp) + x;

            sir = stack[i + radius];

            sir[0] = r[yi];
            sir[1] = g[yi];
            sir[2] = b[yi];

            rbs = r1 - Math.abs(i);

            rsum += r[yi] * rbs;
            gsum += g[yi] * rbs;
            bsum += b[yi] * rbs;

            if (i > 0) {
                rinsum += sir[0];
                ginsum += sir[1];
                binsum += sir[2];
            } else {
                routsum += sir[0];
                goutsum += sir[1];
                boutsum += sir[2];
            }

            if (i < hm) {
                yp += w;
            }
        }
        yi = x;
        stackpointer = radius;
        for (y = 0; y < h; y++) {
            // Preserve alpha channel: ( 0xff000000 & pix[yi] )
            pix[yi] = ( 0xff000000 & pix[yi] ) | ( dv[rsum] << 16 ) | ( dv[gsum] << 8 ) | dv[bsum];

            rsum -= routsum;
            gsum -= goutsum;
            bsum -= boutsum;

            stackstart = stackpointer - radius + div;
            sir = stack[stackstart % div];

            routsum -= sir[0];
            goutsum -= sir[1];
            boutsum -= sir[2];

            if (x == 0) {
                vmin[y] = Math.min(y + r1, hm) * w;
            }
            p = x + vmin[y];

            sir[0] = r[p];
            sir[1] = g[p];
            sir[2] = b[p];

            rinsum += sir[0];
            ginsum += sir[1];
            binsum += sir[2];

            rsum += rinsum;
            gsum += ginsum;
            bsum += binsum;

            stackpointer = (stackpointer + 1) % div;
            sir = stack[stackpointer];

            routsum += sir[0];
            goutsum += sir[1];
            boutsum += sir[2];

            rinsum -= sir[0];
            ginsum -= sir[1];
            binsum -= sir[2];

            yi += w;
        }
    }

    Log.e("pix", w + " " + h + " " + pix.length);
    bitmap.setPixels(pix, 0, w, 0, 0, w, h);

    return (bitmap);
}

jQuery, simple polling example

function make_call()
{
  // do the request

  setTimeout(function(){ 
    make_call();
  }, 5000);
}

$(document).ready(function() {
  make_call();
});

Python try-else

One of the use scenarios I can think of is unpredictable exceptions, which can be circumvented if you try again. For instance, when the operations in try block involves random numbers:

while True:
    try:
        r = random.random()
        some_operation_that_fails_for_specific_r(r)
    except Exception:
        continue
    else:
        break

But if the exception can be predicted, you should always choose validation beforehand over an exception. However, not everything can be predicted, so this code pattern has its place.

How do I draw a grid onto a plot in Python?

Using rcParams you can show grid very easily as follows

plt.rcParams['axes.facecolor'] = 'white'
plt.rcParams['axes.edgecolor'] = 'white'
plt.rcParams['axes.grid'] = True
plt.rcParams['grid.alpha'] = 1
plt.rcParams['grid.color'] = "#cccccc"

If grid is not showing even after changing these parameters then use

plt.grid(True)

before calling

plt.show()

Sorting options elements alphabetically using jQuery

Accepted answer is not the best in all cases because sometimes you want to perserve classes of options and different arguments (for example data-foo).

My solution is:

var sel = $('#select_id');
var selected = sel.val(); // cache selected value, before reordering
var opts_list = sel.find('option');
opts_list.sort(function(a, b) { return $(a).text() > $(b).text() ? 1 : -1; });
sel.html('').append(opts_list);
sel.val(selected); // set cached selected value

//For ie11 or those who get a blank options, replace html('') empty()

dll missing in JDBC

You have to make sure your DLL is in the classpath.

One such way to do so is to put the path to the DLL in PATH environment variable.

Other option is to add it to the VM arguments in the variable LD_LIBRARY_PATH, like this:

java -Djava.library.path=/path/to/my/dll -cp /my/classpath/goes/here MainClass

When to use std::size_t?

size_t is returned by various libraries to indicate that the size of that container is non-zero. You use it when you get once back :0

However, in the your example above looping on a size_t is a potential bug. Consider the following:

for (size_t i = thing.size(); i >= 0; --i) {
  // this will never terminate because size_t is a typedef for
  // unsigned int which can not be negative by definition
  // therefore i will always be >= 0
  printf("the never ending story. la la la la");
}

the use of unsigned integers has the potential to create these types of subtle issues. Therefore imho I prefer to use size_t only when I interact with containers/types that require it.

How to find list intersection?

If you convert the larger of the two lists into a set, you can get the intersection of that set with any iterable using intersection():

a = [1,2,3,4,5]
b = [1,3,5,6]
set(a).intersection(b)

Python Pylab scatter plot error bars (the error on each point is unique)

This is almost like the other answer but you don't need a scatter plot at all, you can simply specify a scatter-plot-like format (fmt-parameter) for errorbar:

import matplotlib.pyplot as plt
x = [1, 2, 3, 4]
y = [1, 4, 9, 16]
e = [0.5, 1., 1.5, 2.]
plt.errorbar(x, y, yerr=e, fmt='o')
plt.show()

Result:

A list of the avaiable fmt parameters can be found for example in the plot documentation:

character   description
'-'     solid line style
'--'    dashed line style
'-.'    dash-dot line style
':'     dotted line style
'.'     point marker
','     pixel marker
'o'     circle marker
'v'     triangle_down marker
'^'     triangle_up marker
'<'     triangle_left marker
'>'     triangle_right marker
'1'     tri_down marker
'2'     tri_up marker
'3'     tri_left marker
'4'     tri_right marker
's'     square marker
'p'     pentagon marker
'*'     star marker
'h'     hexagon1 marker
'H'     hexagon2 marker
'+'     plus marker
'x'     x marker
'D'     diamond marker
'd'     thin_diamond marker
'|'     vline marker
'_'     hline marker

How do I change the default library path for R packages

After a couple of hours of trying to solve the issue in several ways, some of which are described here, for me (on Win 10) the option of creating a Renviron file worked, but a little different from what was written here above. The task is to change the value of the variable R_LIBS_USER. To do this two steps needed:

Create the file named Renviron (without dot) in the folder \Program\etc\ (Programm is the directory where the R installed, for example for me it was c:\Program Files\R\R-4.0.0\etc)
Insert a line in Renviron with new path: R_LIBS_USER=c:/R/Library

It's been working for a few days already.

Sending email from Command-line via outlook without having to click send

Send SMS/Text Messages from Command Line with VBScript!

If VBA meets the rules for VB Script then it can be called from command line by simply placing it into a text file - in this case there's no need to specifically open Outlook.

I had a need to send automated text messages to myself from the command line, so I used the code below, which is just a compressed version of @Geoff's answer above.

Most mobile phone carriers worldwide provide an email address "version" of your mobile phone number. For example in Canada with Rogers or Chatr Wireless, an email sent to <YourPhoneNumber> @pcs.rogers.com will be immediately delivered to your Rogers/Chatr phone as a text message.

* ^{You may need to "authorize" the first message on your phone, and some carriers may charge an additional fee for theses message although as far as I know, all Canadian carriers provide this little-known service for free. Check your carrier's website for details.}

There are further instructions and various compiled lists of worldwide carrier's Email-to-Text addresses available online such as this and this and this.

Code & Instructions

Copy the code below and paste into a new file in your favorite text editor.
Save the file with any name with a .VBS extension, such as TextMyself.vbs.

That's all!
Just double-click the file to send a test message, or else run it from a batch file using START.

Sub SendMessage()
    Const EmailToSMSAddy = "[email protected]"
    Dim objOutlookRecip
    With CreateObject("Outlook.Application").CreateItem(0)
        Set objOutlookRecip = .Recipients.Add(EmailToSMSAddy)
        objOutlookRecip.Type = 1
        .Subject = "The computer needs your attention!"
        .Body = "Go see why Windows Command Line is texting you!"
        .Save
        .Send
    End With
End Sub

Example Batch File Usage:

START x:\mypath\TextMyself.vbs

Of course there are endless possible ways this could be adapted and customized to suit various practical or creative needs.

SHA-256 or MD5 for file integrity

To 1): Yes, on most CPUs, SHA-256 is about only 40% as fast as MD5.

To 2): I would argue for a different algorithm than MD5 in such a case. I would definitely prefer an algorithm that is considered safe. However, this is more a feeling. Cases where this matters would be rather constructed than realistic, e.g. if your backup system encounters an example case of an attack on an MD5-based certificate, you are likely to have two files in such an example with different data, but identical MD5 checksums. For the rest of the cases, it doesn't matter, because MD5 checksums have a collision (= same checksums for different data) virtually only when provoked intentionally. I'm not an expert on the various hashing (checksum generating) algorithms, so I can not suggest another algorithm. Hence this part of the question is still open. Suggested further reading is Cryptographic Hash Function - File or Data Identifier on Wikipedia. Also further down on that page there is a list of cryptographic hash algorithms.

To 3): MD5 is an algorithm to calculate checksums. A checksum calculated using this algorithm is then called an MD5 checksum.

Way to go from recursion to iteration

A question that had been closed as a duplicate of this one had a very specific data structure:

The node had the following structure:

typedef struct {
    int32_t type;
    int32_t valueint;
    double  valuedouble;
    struct  cNODE *next;
    struct  cNODE *prev;
    struct  cNODE *child;
} cNODE;

The recursive deletion function looked like:

void cNODE_Delete(cNODE *c) {
    cNODE*next;
    while (c) {
        next=c->next;
        if (c->child) { 
          cNODE_Delete(c->child)
        }
        free(c);
        c=next;
    }
}

In general, it is not always possible to avoid a stack for recursive functions that invoke itself more than one time (or even once). However, for this particular structure, it is possible. The idea is to flatten all the nodes into a single list. This is accomplished by putting the current node's child at the end of the top row's list.

void cNODE_Delete (cNODE *c) {
    cNODE *tmp, *last = c;
    while (c) {
        while (last->next) {
            last = last->next;   /* find last */
        }
        if ((tmp = c->child)) {
            c->child = NULL;     /* append child to last */
            last->next = tmp;
            tmp->prev = last;
        }
        tmp = c->next;           /* remove current */
        free(c);
        c = tmp;
    }
}

This technique can be applied to any data linked structure that can be reduce to a DAG with a deterministic topological ordering. The current nodes children are rearranged so that the last child adopts all of the other children. Then the current node can be deleted and traversal can then iterate to the remaining child.

Cannot create cache directory .. or directory is not writable. Proceeding without cache in Laravel

I had a similar problem recently, and needed to change the permissions of my vendor folder

By running following commands :

php artisan cache:clear
chmod -R 777 storage vendor
composer dump-autoload

I need to give all the permissions required to open and write vendor files to solve this issue

jump to line X in nano editor

In the nano editor

Ctrl+_

On openning a file

nano +10 file.txt

Change color inside strings.xml

Try this

For red color,

<string name="hello_worldRed"><![CDATA[<b><font color=#FF0000>Hello world!</font></b>]]></string>

For blue,

<string name="hello_worldBlue"><![CDATA[<b><font color=#0000FF>Hello world!</font></b>]]></string>

In java code,

//red color text
TextView redColorTextView = (TextView)findViewById(R.id.redText);
String redString = getResources().getString(R.string.hello_worldRed)
redColorTextView.setText(Html.fromHtml(redString));

//Blue color text
TextView blueColorTextView = (TextView)findViewById(R.id.blueText);
String blueString = getResources().getString(R.string.hello_worldBlue)
blueColorTextView.setText(Html.fromHtml(blueString));

Force R not to use exponential notation (e.g. e+10)?

Get size of all tables in database

The currently accepted answer has over 2600 up-votes but gives incorrect results when working with multiple partitions and/or filtered indexes. It also doesn't distinguish between the size of the data and indexes, which is often very relevant. Several suggested fixes don't address the core problem or are simply wrong as well.

The following query addresses all of those issues.

SELECT 
     [object_id]        = t.[object_id]
    ,[schema_name]      = s.[name]
    ,[table_name]       = t.[name]
    ,[index_name]       = CASE WHEN i.[type] in (0,1,5) THEN null    ELSE i.[name] END -- 0=Heap; 1=Clustered; 5=Clustered Columnstore
    ,[object_type]      = CASE WHEN i.[type] in (0,1,5) THEN 'TABLE' ELSE 'INDEX'  END
    ,[index_type]       = i.[type_desc]
    ,[partition_count]  = p.partition_count
    ,[row_count]        = p.[rows]
    ,[data_compression] = CASE WHEN p.data_compression_cnt > 1 THEN 'Mixed'
                               ELSE (  SELECT DISTINCT p.data_compression_desc
                                       FROM sys.partitions p
                                       WHERE i.[object_id] = p.[object_id] AND i.index_id = p.index_id
                                    )
                          END
    ,[total_space_MB]   = cast(round(( au.total_pages                  * (8/1024.00)), 2) AS DECIMAL(36,2))
    ,[used_space_MB]    = cast(round(( au.used_pages                   * (8/1024.00)), 2) AS DECIMAL(36,2))
    ,[unused_space_MB]  = cast(round(((au.total_pages - au.used_pages) * (8/1024.00)), 2) AS DECIMAL(36,2))
FROM sys.schemas s
JOIN sys.tables  t ON s.schema_id = t.schema_id
JOIN sys.indexes i ON t.object_id = i.object_id
JOIN (
    SELECT [object_id], index_id, partition_count=count(*), [rows]=sum([rows]), data_compression_cnt=count(distinct [data_compression])
    FROM sys.partitions
    GROUP BY [object_id], [index_id]
) p ON i.[object_id] = p.[object_id] AND i.[index_id] = p.[index_id]
JOIN (
    SELECT p.[object_id], p.[index_id], total_pages = sum(a.total_pages), used_pages = sum(a.used_pages), data_pages=sum(a.data_pages)
    FROM sys.partitions p
    JOIN sys.allocation_units a ON p.[partition_id] = a.[container_id]
    GROUP BY p.[object_id], p.[index_id]
) au ON i.[object_id] = au.[object_id] AND i.[index_id] = au.[index_id]
WHERE t.is_ms_shipped = 0 -- Not a system table

Is JavaScript a pass-by-reference or pass-by-value language?

JavaScript is always pass-by-value; everything is of value type.

Objects are values, and member functions of objects are values themselves (remember that functions are first-class objects in JavaScript). Also, regarding the concept that everything in JavaScript is an object; this is wrong. Strings, symbols, numbers, booleans, nulls, and undefineds are primitives.

On occasion they can leverage some member functions and properties inherited from their base prototypes, but this is only for convenience. It does not mean that they are objects themselves. Try the following for reference:

x = "test";
alert(x.foo);
x.foo = 12;
alert(x.foo);

In both alerts you will find the value to be undefined.

PyTorch: How to get the shape of a Tensor as a list of int

If you're a fan of NumPyish syntax, then there's tensor.shape.

In [3]: ar = torch.rand(3, 3)

In [4]: ar.shape
Out[4]: torch.Size([3, 3])

# method-1
In [7]: list(ar.shape)
Out[7]: [3, 3]

# method-2
In [8]: [*ar.shape]
Out[8]: [3, 3]

# method-3
In [9]: [*ar.size()]
Out[9]: [3, 3]

P.S.: Note that tensor.shape is an alias to tensor.size(), though tensor.shape is an attribute of the tensor in question whereas tensor.size() is a function.

Generating a Random Number between 1 and 10 Java

As the documentation says, this method call returns "a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive)". This means that you will get numbers from 0 to 9 in your case. So you've done everything correctly by adding one to that number.

Generally speaking, if you need to generate numbers from min to max (including both), you write

random.nextInt(max - min + 1) + min

Serializing PHP object to JSON

In the simplest cases type hinting should work:

$json = json_encode( (array)$object );

Get the directory from a file path in java (android)

Yes. First, construct a File representing the image path:

File file = new File(a);

If you're starting from a relative path:

file = new File(file.getAbsolutePath());

Then, get the parent:

String dir = file.getParent();

Or, if you want the directory as a File object,

File dirAsFile = file.getParentFile();

Python, HTTPS GET with basic authentication

A correct way to do basic auth in Python3 urllib.request with certificate validation follows.

Note that certifi is not mandatory. You can use your OS bundle (likely *nix only) or distribute Mozilla's CA Bundle yourself. Or if the hosts you communicate with are just a few, concatenate CA file yourself from the hosts' CAs, which can reduce the risk of MitM attack caused by another corrupt CA.

#!/usr/bin/env python3


import urllib.request
import ssl

import certifi


context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
context.verify_mode = ssl.CERT_REQUIRED
context.load_verify_locations(certifi.where())
httpsHandler = urllib.request.HTTPSHandler(context = context)

manager = urllib.request.HTTPPasswordMgrWithDefaultRealm()
manager.add_password(None, 'https://domain.com/', 'username', 'password')
authHandler = urllib.request.HTTPBasicAuthHandler(manager)

opener = urllib.request.build_opener(httpsHandler, authHandler)

# Used globally for all urllib.request requests.
# If it doesn't fit your design, use opener directly.
urllib.request.install_opener(opener)

response = urllib.request.urlopen('https://domain.com/some/path')
print(response.read())

Find full path of the Python interpreter?

sys.executable contains full path of the currently running Python interpreter.

import sys

print(sys.executable)

which is now documented here

Get a file name from a path

For long time I was looking for a function able to properly decompose file path. For me this code is working perfectly for both Linux and Windows.

void decomposePath(const char *filePath, char *fileDir, char *fileName, char *fileExt)
{
    #if defined _WIN32
        const char *lastSeparator = strrchr(filePath, '\\');
    #else
        const char *lastSeparator = strrchr(filePath, '/');
    #endif

    const char *lastDot = strrchr(filePath, '.');
    const char *endOfPath = filePath + strlen(filePath);
    const char *startOfName = lastSeparator ? lastSeparator + 1 : filePath;
    const char *startOfExt = lastDot > startOfName ? lastDot : endOfPath;

    if(fileDir)
        _snprintf(fileDir, MAX_PATH, "%.*s", startOfName - filePath, filePath);

    if(fileName)
        _snprintf(fileName, MAX_PATH, "%.*s", startOfExt - startOfName, startOfName);

    if(fileExt)
        _snprintf(fileExt, MAX_PATH, "%s", startOfExt);
}

Example results are:

[]
  fileDir:  ''
  fileName: ''
  fileExt:  ''

[.htaccess]
  fileDir:  ''
  fileName: '.htaccess'
  fileExt:  ''

[a.exe]
  fileDir:  ''
  fileName: 'a'
  fileExt:  '.exe'

[a\b.c]
  fileDir:  'a\'
  fileName: 'b'
  fileExt:  '.c'

[git-archive]
  fileDir:  ''
  fileName: 'git-archive'
  fileExt:  ''

[git-archive.exe]
  fileDir:  ''
  fileName: 'git-archive'
  fileExt:  '.exe'

[D:\Git\mingw64\libexec\git-core\.htaccess]
  fileDir:  'D:\Git\mingw64\libexec\git-core\'
  fileName: '.htaccess'
  fileExt:  ''

[D:\Git\mingw64\libexec\git-core\a.exe]
  fileDir:  'D:\Git\mingw64\libexec\git-core\'
  fileName: 'a'
  fileExt:  '.exe'

[D:\Git\mingw64\libexec\git-core\git-archive.exe]
  fileDir:  'D:\Git\mingw64\libexec\git-core\'
  fileName: 'git-archive'
  fileExt:  '.exe'

[D:\Git\mingw64\libexec\git.core\git-archive.exe]
  fileDir:  'D:\Git\mingw64\libexec\git.core\'
  fileName: 'git-archive'
  fileExt:  '.exe'

[D:\Git\mingw64\libexec\git-core\git-archiveexe]
  fileDir:  'D:\Git\mingw64\libexec\git-core\'
  fileName: 'git-archiveexe'
  fileExt:  ''

[D:\Git\mingw64\libexec\git.core\git-archiveexe]
  fileDir:  'D:\Git\mingw64\libexec\git.core\'
  fileName: 'git-archiveexe'
  fileExt:  ''

I hope this helps you also :)

Array versus linked-list

Besides convenience in insertions and deletions, the memory representation of linked list is different than the arrays. There is no restriction on the number of elements in a linked list, while in the arrays, you have to specify the total number of elements. Check this article.

How to show only next line after the matched one?

Great answer from raim, was very useful for me. It is trivial to extend this to print e.g. line 7 after the pattern

awk -v lines=7 '/blah/ {for(i=lines;i;--i)getline; print $0 }' logfile

How to copy to clipboard in Vim?

I had issue because my vim was not supporting clipboard:

vim --version | grep clip
-clipboard       +insert_expand   +path_extra      +user_commands
+emacs_tags      -mouseshape      +startuptime     -xterm_clipboard

I installed vim-gnome (which support clipboard) and then checked again:

vim --version | grep clipboard
+clipboard       +insert_expand   +path_extra      +user_commands
+emacs_tags      +mouseshape      +startuptime     +xterm_clipboard

Now I am able to copy and paste using "+y and "+p respectively.

Finding what branch a Git commit came from

This simple command works like a charm:

git name-rev <SHA>

For example (where test-branch is the branch name):

git name-rev 651ad3a
251ad3a remotes/origin/test-branch

Even this is working for complex scenarios, like:

origin/branchA/
              /branchB
                      /commit<SHA1>
                                   /commit<SHA2>

Here git name-rev commit<SHA2> returns branchB.

How to manage startActivityForResult on Android?

First you use startActivityForResult() with parameters in first Activity and if you want to send data from second Activity to first Activity then pass value using Intent with setResult() method and get that data inside onActivityResult() method in first Activity.

Passing arguments to C# generic new() of templated type

Very old question, but new answer ;-)

The ExpressionTree version: (I think the fastests and cleanest solution)

Like Welly Tambunan said, "we could also use expression tree to build the object"

This will generate a 'constructor' (function) for the type/parameters given. It returns a delegate and accept the parameter types as an array of objects.

Here it is:

// this delegate is just, so you don't have to pass an object array. _(params)_
public delegate object ConstructorDelegate(params object[] args);

public static ConstructorDelegate CreateConstructor(Type type, params Type[] parameters)
{
    // Get the constructor info for these parameters
    var constructorInfo = type.GetConstructor(parameters);

    // define a object[] parameter
    var paramExpr = Expression.Parameter(typeof(Object[]));

    // To feed the constructor with the right parameters, we need to generate an array 
    // of parameters that will be read from the initialize object array argument.
    var constructorParameters = parameters.Select((paramType, index) =>
        // convert the object[index] to the right constructor parameter type.
        Expression.Convert(
            // read a value from the object[index]
            Expression.ArrayAccess(
                paramExpr,
                Expression.Constant(index)),
            paramType)).ToArray();

    // just call the constructor.
    var body = Expression.New(constructorInfo, constructorParameters);

    var constructor = Expression.Lambda<ConstructorDelegate>(body, paramExpr);
    return constructor.Compile();
}

Example MyClass:

public class MyClass
{
    public int TestInt { get; private set; }
    public string TestString { get; private set; }

    public MyClass(int testInt, string testString)
    {
        TestInt = testInt;
        TestString = testString;
    }
}

Usage:

// you should cache this 'constructor'
var myConstructor = CreateConstructor(typeof(MyClass), typeof(int), typeof(string));

// Call the `myConstructor` function to create a new instance.
var myObject = myConstructor(10, "test message");

Another example: passing the types as an array

var type = typeof(MyClass);
var args = new Type[] { typeof(int), typeof(string) };

// you should cache this 'constructor'
var myConstructor = CreateConstructor(type, args);

// Call the `myConstructor` fucntion to create a new instance.
var myObject = myConstructor(10, "test message");

DebugView of Expression

.Lambda #Lambda1<TestExpressionConstructor.MainWindow+ConstructorDelegate>(System.Object[] $var1) {
    .New TestExpressionConstructor.MainWindow+MyClass(
        (System.Int32)$var1[0],
        (System.String)$var1[1])
}

This is equivalent to the code that is generated:

public object myConstructor(object[] var1)
{
    return new MyClass(
        (System.Int32)var1[0],
        (System.String)var1[1]);
}

Small downside

All valuetypes parameters are boxed when they are passed like an object array.

Simple performance test:

private void TestActivator()
{
    Stopwatch sw = Stopwatch.StartNew();
    for (int i = 0; i < 1024 * 1024 * 10; i++)
    {
        var myObject = Activator.CreateInstance(typeof(MyClass), 10, "test message");
    }
    sw.Stop();
    Trace.WriteLine("Activator: " + sw.Elapsed);
}

private void TestReflection()
{
    var constructorInfo = typeof(MyClass).GetConstructor(new[] { typeof(int), typeof(string) });

    Stopwatch sw = Stopwatch.StartNew();
    for (int i = 0; i < 1024 * 1024 * 10; i++)
    {
        var myObject = constructorInfo.Invoke(new object[] { 10, "test message" });
    }

    sw.Stop();
    Trace.WriteLine("Reflection: " + sw.Elapsed);
}

private void TestExpression()
{
    var myConstructor = CreateConstructor(typeof(MyClass), typeof(int), typeof(string));

    Stopwatch sw = Stopwatch.StartNew();

    for (int i = 0; i < 1024 * 1024 * 10; i++)
    {
        var myObject = myConstructor(10, "test message");
    }

    sw.Stop();
    Trace.WriteLine("Expression: " + sw.Elapsed);
}

TestActivator();
TestReflection();
TestExpression();

Results:

Activator: 00:00:13.8210732
Reflection: 00:00:05.2986945
Expression: 00:00:00.6681696

Using Expressions is +/- 8 times faster than Invoking the ConstructorInfo and +/- 20 times faster than using the Activator

Firing a Keyboard Event in Safari, using JavaScript

The Mozilla Developer Network provides the following explanation:

Create an event using event = document.createEvent("KeyboardEvent")
Init the keyevent

using:

event.initKeyEvent (type, bubbles, cancelable, viewArg, 
       ctrlKeyArg, altKeyArg, shiftKeyArg, metaKeyArg, 
           keyCodeArg, charCodeArg)

Dispatch the event using yourElement.dispatchEvent(event)

I don't see the last one in your code, maybe that's what you're missing. I hope this works in IE as well...

NameError: name 'python' is not defined

When you run the Windows Command Prompt, and type in python, it starts the Python interpreter.

Typing it again tries to interpret python as a variable, which doesn't exist and thus won't work:

Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

C:\Users\USER>python
Python 2.7.5 (default, May 15 2013, 22:43:36) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> python
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'python' is not defined
>>> print("interpreter has started")
interpreter has started
>>> quit() # leave the interpreter, and go back to the command line

C:\Users\USER>

If you're not doing this from the command line, and instead running the Python interpreter (python.exe or IDLE's shell) directly, you are not in the Windows Command Line, and python is interpreted as a variable, which you have not defined.

Django request.GET

In python, None, 0, ""(empty string), False are all accepted None.

So:

if request.GET['q']: // true if q contains anything but not ""
    message
else : //// since this returns "" ant this is equals to None
    error

What are the special dollar sign shell variables?

Take care with some of the examples; $0 may include some leading path as well as the name of the program. Eg save this two line script as ./mytry.sh and the execute it.

#!/bin/bash

echo "parameter 0 --> $0" ; exit 0

Output:

parameter 0 --> ./mytry.sh

This is on a current (year 2016) version of Bash, via Slackware 14.2

#ifdef in C#

I would recommend you using the Conditional Attribute!

Update: 3.5 years later

You can use #if like this (example copied from MSDN):

// preprocessor_if.cs
#define DEBUG
#define VC_V7
using System;
public class MyClass 
{
    static void Main() 
    {
#if (DEBUG && !VC_V7)
        Console.WriteLine("DEBUG is defined");
#elif (!DEBUG && VC_V7)
        Console.WriteLine("VC_V7 is defined");
#elif (DEBUG && VC_V7)
        Console.WriteLine("DEBUG and VC_V7 are defined");
#else
        Console.WriteLine("DEBUG and VC_V7 are not defined");
#endif
    }
}

Only useful for excluding parts of methods.

If you use #if to exclude some method from compilation then you will have to exclude from compilation all pieces of code which call that method as well (sometimes you may load some classes at runtime and you cannot find the caller with "Find all references"). Otherwise there will be errors.

If you use conditional compilation on the other hand you can still leave all pieces of code that call the method. All parameters will still be validated by the compiler. The method just won't be called at runtime. I think that it is way better to hide the method just once and not have to remove all the code that calls it as well. You are not allowed to use the conditional attribute on methods which return value - only on void methods. But I don't think this is a big limitation because if you use #if with a method that returns a value you have to hide all pieces of code that call it too.

Here is an example:


    // calling Class1.ConditionalMethod() will be ignored at runtime 
    // unless the DEBUG constant is defined


    using System.Diagnostics;
    class Class1 
    {
       [Conditional("DEBUG")]
       public static void ConditionalMethod() {
          Console.WriteLine("Executed Class1.ConditionalMethod");
       }
    }

Summary:

I would use #ifdef in C++ but with C#/VB I would use Conditional attribute. This way you hide the method definition without having to hide the pieces of code that call it. The calling code is still compiled and validated by the compiler, the method is not called at runtime though. You may want to use #if to avoid dependencies because with Conditional attribute your code is still compiled.

Turning off eslint rule for a specific line

Or for multiple ignores on the next line, string the rules using commas

// eslint-disable-next-line class-methods-use-this, no-unused-vars

Forbidden: You don't have permission to access / on this server, WAMP Error

Adding Allow from All didn't worked for me. Then I tried this and it worked.

OS: Windows 8.1
Wamp : 2.5

I added this in the file C:\wamp\bin\apache\apache2.4.9\conf\extra\httpd-vhosts.conf

<VirtualHost *:80>
    ServerAdmin [email protected]
    DocumentRoot "c:/wamp/www/"
    ServerName localhost
    ServerAlias localhost
    ErrorLog "logs/localhost-error.log"
    CustomLog "logs/localhost-access.log" common
</VirtualHost>

How to have an automatic timestamp in SQLite?

If you use the SQLite DB-Browser you can change the default value in this way:

Choose database structure
select the table
modify table
in your column put under 'default value' the value: =(datetime('now','localtime'))

I recommend to make an update of your database before, because a wrong format in the value can lead to problems in the SQLLite Browser.

PHP to write Tab Characters inside a file?

The tab character is \t. Notice the use of " instead of '.

$chunk = "abc\tdef\tghi";

PHP Strings - Double quoted

If the string is enclosed in double-quotes ("), PHP will interpret more escape sequences for special characters:

...

\t horizontal tab (HT or 0x09 (9) in ASCII)

Also, let me recommend the fputcsv() function which is for the purpose of writing CSV files.

How to make a transparent border using CSS?

Well if you want fully transparent than you can use

border: 5px solid transparent;

If you mean opaque/transparent, than you can use

border: 5px solid rgba(255, 255, 255, .5);

Here, a means alpha, which you can scale, 0-1.

Also some might suggest you to use opacity which does the same job as well, the only difference is it will result in child elements getting opaque too, yes, there are some work arounds but rgba seems better than using opacity.

For older browsers, always declare the background color using #(hex) just as a fall back, so that if old browsers doesn't recognize the rgba, they will apply the hex color to your element.

Demo

Demo 2 (With a background image for nested div)

Demo 3 (With an img tag instead of a background-image)

body {
    background: url(http://www.desktopas.com/files/2013/06/Images-1920x1200.jpg);   
}

div.wrap {
    border: 5px solid #fff; /* Fall back, not used in fiddle */
    border: 5px solid rgba(255, 255, 255, .5);
    height: 400px;
    width: 400px;
    margin: 50px;
    border-radius: 50%;
}

div.inner {
    background: #fff; /* Fall back, not used in fiddle */
    background: rgba(255, 255, 255, .5);
    height: 380px;
    width: 380px;
    border-radius: 50%; 
    margin: auto; /* Horizontal Center */
    margin-top: 10px; /* Vertical Center ... Yea I know, that's 
                         manually calculated*/
}

Note (For Demo 3): Image will be scaled according to the height and width provided so make sure it doesn't break the scaling ratio.

Removing display of row names from data frame

Recently I had the same problem when using htmlTable() (‘htmlTable’ package) and I found a simpler solution: convert the data frame to a matrix with as.matrix():

htmlTable(as.matrix(df))

And be sure that the rownames are just indices. as.matrix() conservs the same columnames. That's it.

UPDATE

Following the comment of @DMR, I did't notice that htmlTable() has the parameter rnames = FALSE for cases like this. So a better answer would be:

htmlTable(df, rnames = FALSE)

HashMap: One Key, multiple Values

Write a new class that holds all the values that you need and use the new class's object as the value in your HashMap

HashMap<String, MyObject>

class MyObject {
public String value1;
public int value2;
public List<String> value3;
}

Git for Windows: .bashrc or equivalent configuration files for Git Bash shell

I had to add a user environment variable, HOME, with C:\Users\<your user name> by going to System, Advanced System Settings, in the System Properties window, the Advanced tab, Environment Variables...

Then in my C:\Users\<your user name> I created the file .bashrc, e.g., touch .bashrc and added the desired aliases.

How to get the last element of a slice?

Bit less elegant but can also do:

sl[len(sl)-1: len(sl)]

How to make a countdown timer in Android?

Try this way:

private void startTimer() {
    startTimer = new CountDownTimer(30000, 1000) {

        public void onTick(long millisUntilFinished) {

            long sec = (TimeUnit.MILLISECONDS.toSeconds(millisUntilFinished) -
 TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(millisUntilFinished)));

            Log.e(TAG, "onTick: "+sec );
            tv_timer.setText(String.format("( %02d SEC )", sec));
            if(sec == 1)
            {

                new Handler().postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        tv_timer.setText("( 00 SEC )");
                    }
                }, 1000);
            }


        }

        public void onFinish() {
            tv_timer.setText("Timer finish");
        }
    }.start();
}

MongoDB: How to find out if an array field contains an element?

I am trying to explain by putting problem statement and solution to it. I hope it will help

Problem Statement:

Find all the published products, whose name like ABC Product or PQR Product, and price should be less than 15/-

Solution:

Below are the conditions that need to be taken care of

Product price should be less than 15
Product name should be either ABC Product or PQR Product
Product should be in published state.

Below is the statement that applies above criterion to create query and fetch data.

$elements = $collection->find(
             Array(
                [price] => Array( [$lt] => 15 ),
                [$or] => Array(
                            [0]=>Array(
                                    [product_name]=>Array(
                                       [$in]=>Array(
                                            [0] => ABC Product,
                                            [1]=> PQR Product
                                            )
                                        )
                                    )
                                ),
                [state]=>Published
                )
            );

Change Twitter Bootstrap Tooltip content on click

In bootstrap 4 I just use $(el).tooltip('dispose'); then recreate as normal. So you can put the dispose before a function that creates a tooltip to be sure it doesn't double up.

Having to check the state and tinker with values seems less friendly.

Set bootstrap modal body height by percentage

The scss solution for Bootstrap 4.0

.modal { max-height: 100vh; .modal-dialog { .modal-content { .modal-body { max-height: calc(80vh - 140px); overflow-y: auto; } } } }

Make sure the .modal max-height is 100vh. Then for .modal-body use calc() function to calculate desired height. In above case we want to occupy 80vh of the viewport, reduced by the size of header + footer in pixels. This is around 140px together but you can measure it easily and apply your own custom values. For smaller/taller modal modify 80vh accordingly.

When should you use constexpr capability in C++11?

There used to be a pattern with metaprogramming:

template<unsigned T>
struct Fact {
    enum Enum {
        VALUE = Fact<T-1>*T;
    };
};

template<>
struct Fact<1u> {
    enum Enum {
        VALUE = 1;
    };
};

// Fact<10>::VALUE is known be a compile-time constant

I believe constexpr was introduced to let you write such constructs without the need for templates and weird constructs with specialization, SFINAE and stuff - but exactly like you'd write a run-time function, but with the guarantee that the result will be determined in compile-time.

However, note that:

int fact(unsigned n) {
    if (n==1) return 1;
    return fact(n-1)*n;
}

int main() {
    return fact(10);
}

Compile this with g++ -O3 and you'll see that fact(10) is indeed evaulated at compile-time!

An VLA-aware compiler (so a C compiler in C99 mode or C++ compiler with C99 extensions) may even allow you to do:

int main() {
    int tab[fact(10)];
    int tab2[std::max(20,30)];
}

But that it's non-standard C++ at the moment - constexpr looks like a way to combat this (even without VLA, in the above case). And there's still the problem of the need to have "formal" constant expressions as template arguments.

Call jQuery Ajax Request Each X Minutes

I found a very good jquery plugin that can ease your life with this type of operation. You can checkout https://github.com/ocombe/jQuery-keepAlive.

$.fn.keepAlive({url: 'your-route/filename', timer: 'time'},       function(response) {
        console.log(response);
      });//

Command-line svn for Windows?

cygwin is another option. It has a port of svn.

Get user's current location

The old freegeoip API is now deprecated and will be discontinued on July 1st, 2018.

The new API is from https://ipstack.com. You have to create the account in ipstack.Then you can use the access key in the API url.

$url = "http://api.ipstack.com/122.167.180.20?access_key=ACCESS_KEY&format=1";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_PROXYPORT, 3128);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
$response = curl_exec($ch);
curl_close($ch);
$response = json_decode($response);
$city  = $response->city; //You can get all the details like longitude,latitude from the $response .

For more information check here :/ https://github.com/apilayer/freegeoip

ImportError: No module named xlsxwriter

I have the same issue. It seems that pip is the problem. Try

pip uninstall xlsxwriter
easy_install xlsxwriter

Spring's overriding bean

An example from official spring manual:

<bean id="inheritedTestBean" abstract="true"
    class="org.springframework.beans.TestBean">
  <property name="name" value="parent"/>
  <property name="age" value="1"/>
</bean>

<bean id="inheritsWithDifferentClass"
      class="org.springframework.beans.DerivedTestBean"
      parent="inheritedTestBean" init-method="initialize">
  <property name="name" value="override"/>
  <!-- the age property value of 1 will be inherited from  parent -->
</bean>

Is that what you was looking for? Updated link

Vim: How to insert in visual block mode?

press ctrl and v // start select
press shift and i // then type in any text
press esc esc // press esc twice

show loading icon until the page is load?

HTML

<body>
    <div id="load"></div>
    <div id="contents">
          jlkjjlkjlkjlkjlklk
    </div>
</body>

document.onreadystatechange = function () {
  var state = document.readyState
  if (state == 'interactive') {
       document.getElementById('contents').style.visibility="hidden";
  } else if (state == 'complete') {
      setTimeout(function(){
         document.getElementById('interactive');
         document.getElementById('load').style.visibility="hidden";
         document.getElementById('contents').style.visibility="visible";
      },1000);
  }
}

CSS

#load{
    width:100%;
    height:100%;
    position:fixed;
    z-index:9999;
    background:url("https://www.creditmutuel.fr/cmne/fr/banques/webservices/nswr/images/loading.gif") no-repeat center center rgba(0,0,0,0.25)
}

Note:
you wont see any loading gif if your page is loaded fast, so use this code on a page with high loading time, and i also recommend to put your js on the bottom of the page.

DEMO

http://jsfiddle.net/6AcAr/ - with timeout(only for demo)
http://jsfiddle.net/47PkH/ - no timeout(use this for actual page)

update

http://jsfiddle.net/d9ngT/

Open Sublime Text from Terminal in macOS

This is to get it working as an ALIAS, not a Symbolic link!

This will allow you to run additional commands in the terminal without interrupting the subl session. Using many of the symbolic link answers here (ln -s), cause the terminal process to endure while using Sublime text. If you want the separation, create an alias in the Bash profile like so:

Test subl from your ST installation:

First, navigate to a folder in Terminal that you want ST to open and enter the following command:
```
/Applications/Sublime\ Text.app/Contents/SharedSupport/bin/subl .
```
NOTE: You may need to replace Sublime\ Text.app in the command above to Sublime\ Text\ 3.app or Sublime\ Text\ 2.app depending upon where the application is stored in your Applications directory. The . at the end of the above command opens the current working directory you are located in (again make sure you're in a directory that only contains a few files!).

If you DO NOT get Sublime Text opening your current working directory then the next set of steps will NOT work. If nothing happens or you get an error from Terminal it will be because it couldn't find the Sublime Text application. This would mean that you would have to check what you've typed (spelling, etc.) OR that Sublime Text isn't installed!
Check and update ".bash_profile":

Now add the alias in your Bash Profile. Open it via vim ~/.bash_profile. These are the following lines that pertain to having subl work on the command line for Sublime Text:
```
## For Sublime Text 3 alias
alias subl='/Applications/Sublime\ Text.app/Contents/SharedSupport/bin/subl'
## For Sublime Text global editor preference **Optional
export EDITOR='subl -w'
```
I suggest always commenting your code in here with ##. The second line is OPTIONAL and just sets Sublime Text as the default editor. The flag -w has been added and you can find out more about flags by going to the Sublime Text docs: ST3 subl or ST2 subl

If you do make any edits to this file once you have closed it, you need to source this file in your current session or close the terminal (tab) and open a new one. You can source this file by running the command source ~/.bash_profile Resolve any errors before moving to the final step.

Associating enums with strings in C#

New in .Net Core 3.0/C# 8.0 (if your work environment allows you to upgrade your project) is a short-hand switch statement that looks somewhat enum-ish. At the end of the day it's the same old boring switch statement we've been using for years.

Only real difference here is that the switch statement got a new suit.

public static RGBColor FromRainbow(Rainbow colorBand) =>
colorBand switch
{
    Rainbow.Red    => new RGBColor(0xFF, 0x00, 0x00),
    Rainbow.Orange => new RGBColor(0xFF, 0x7F, 0x00),
    Rainbow.Yellow => new RGBColor(0xFF, 0xFF, 0x00),
    Rainbow.Green  => new RGBColor(0x00, 0xFF, 0x00),
    Rainbow.Blue   => new RGBColor(0x00, 0x00, 0xFF),
    Rainbow.Indigo => new RGBColor(0x4B, 0x00, 0x82),
    Rainbow.Violet => new RGBColor(0x94, 0x00, 0xD3),
    _              => throw new ArgumentException(message: "invalid enum value", paramName: nameof(colorBand)),
};

You'll notice that the code above which I copied from here, is actually using an enum as a param.

It's not exactly what you want (and trust me, I've wanted something of similar to what the OP is requesting for a long time), but I actually feel like this is somewhat of an olive branch from MS. JMO.

Hope it helps someone!

OpenSSL: unable to verify the first certificate for Experian URL

The first error message is telling you more about the problem:

verify error:num=20:unable to get local issuer certificate

The issuing certificate authority of the end entity server certificate is

VeriSign Class 3 Secure Server CA - G3

Look closely in your CA file - you will not find this certificate since it is an intermediary CA - what you found was a similar-named G3 Public Primary CA of VeriSign.

But why does the other connection succeed, but this one doesn't? The problem is a misconfiguration of the servers (see for yourself using the -debug option). The "good" server sends the entire certificate chain during the handshake, therefore providing you with the necessary intermediate certificates.

But the server that is failing sends you only the end entity certificate, and OpenSSL is not capable of downloading the missing intermediate certificate "on the fly" (which would be possible by interpreting the Authority Information Access extension). Therefore your attempt fails using s_client but it would succeed nevertheless if you browse to the same URL using e.g. FireFox (which does support the "certificate discovery" feature).

Your options to solve the problem are either fixing this on the server side by making the server send the entire chain, too, or by passing the missing intermediate certificate to OpenSSL as a client-side parameter.

Why am I getting an error "Object literal may only specify known properties"?

As of TypeScript 1.6, properties in object literals that do not have a corresponding property in the type they're being assigned to are flagged as errors.

Usually this error means you have a bug (typically a typo) in your code, or in the definition file. The right fix in this case would be to fix the typo. In the question, the property callbackOnLoactionHash is incorrect and should have been callbackOnLocationHash (note the mis-spelling of "Location").

This change also required some updates in definition files, so you should get the latest version of the .d.ts for any libraries you're using.

Example:

interface TextOptions {
    alignment?: string;
    color?: string;
    padding?: number;
}
function drawText(opts: TextOptions) { ... }
drawText({ align: 'center' }); // Error, no property 'align' in 'TextOptions'

But I meant to do that

There are a few cases where you may have intended to have extra properties in your object. Depending on what you're doing, there are several appropriate fixes

Type-checking only some properties

Sometimes you want to make sure a few things are present and of the correct type, but intend to have extra properties for whatever reason. Type assertions (<T>v or v as T) do not check for extra properties, so you can use them in place of a type annotation:

interface Options {
    x?: string;
    y?: number;
}

// Error, no property 'z' in 'Options'
let q1: Options = { x: 'foo', y: 32, z: 100 };
// OK
let q2 = { x: 'foo', y: 32, z: 100 } as Options;
// Still an error (good):
let q3 = { x: 100, y: 32, z: 100 } as Options;

These properties and maybe more

Some APIs take an object and dynamically iterate over its keys, but have 'special' keys that need to be of a certain type. Adding a string indexer to the type will disable extra property checking

Before

interface Model {
  name: string;
}
function createModel(x: Model) { ... }

// Error
createModel({name: 'hello', length: 100});

After

interface Model {
  name: string;
  [others: string]: any;
}
function createModel(x: Model) { ... }

// OK
createModel({name: 'hello', length: 100});

This is a dog or a cat or a horse, not sure yet

interface Animal { move; }
interface Dog extends Animal { woof; }
interface Cat extends Animal { meow; }
interface Horse extends Animal { neigh; }

let x: Animal;
if(...) {
  x = { move: 'doggy paddle', woof: 'bark' };
} else if(...) {
  x = { move: 'catwalk', meow: 'mrar' };
} else {
  x = { move: 'gallop', neigh: 'wilbur' };
}

Two good solutions come to mind here

Specify a closed set for x

// Removes all errors
let x: Dog|Cat|Horse;

or Type assert each thing

// For each initialization
  x = { move: 'doggy paddle', woof: 'bark' } as Dog;

This type is sometimes open and sometimes not

A clean solution to the "data model" problem using intersection types:

interface DataModelOptions {
  name?: string;
  id?: number;
}
interface UserProperties {
  [key: string]: any;
}
function createDataModel(model: DataModelOptions & UserProperties) {
 /* ... */
}
// findDataModel can only look up by name or id
function findDataModel(model: DataModelOptions) {
 /* ... */
}
// OK
createDataModel({name: 'my model', favoriteAnimal: 'cat' });
// Error, 'ID' is not correct (should be 'id')
findDataModel({ ID: 32 });

CSS override rules and specificity

To give the second rule higher specificity you can always use parts of the first rule. In this case I would add table.rule1 trfrom rule one and add it to rule two.

table.rule1 tr td {
    background-color: #ff0000;
}

table.rule1 tr td.rule2 {
    background-color: #ffff00;
}

After a while I find this gets natural, but I know some people disagree. For those people I would suggest looking into LESS or SASS.

SQL, Postgres OIDs, What are they and why are they useful?

OIDs basically give you a built-in id for every row, contained in a system column (as opposed to a user-space column). That's handy for tables where you don't have a primary key, have duplicate rows, etc. For example, if you have a table with two identical rows, and you want to delete the oldest of the two, you could do that using the oid column.

OIDs are implemented using 4-byte unsigned integers. They are not unique–OID counter will wrap around at 2³²-1. OID are also used to identify data types (see /usr/include/postgresql/server/catalog/pg_type_d.h).

In my experience, the feature is generally unused in most postgres-backed applications (probably in part because they're non-standard), and their use is essentially deprecated:

In PostgreSQL 8.1 default_with_oids is off by default; in prior versions of PostgreSQL, it was on by default.

The use of OIDs in user tables is considered deprecated, so most installations should leave this variable disabled. Applications that require OIDs for a particular table should specify WITH OIDS when creating the table. This variable can be enabled for compatibility with old applications that do not follow this behavior.

How to detect if multiple keys are pressed at once using JavaScript?

Make the keydown even call multiple functions, with each function checking for a specific key and responding appropriately.

document.keydown = function (key) {

    checkKey("x");
    checkKey("y");
};

pip installs packages successfully, but executables not found from command line

On macOS with the default python installation you need to add /Users/<you>/Library/Python/2.7/bin/ to your $PATH.

Add this to your .bash_profile:

export PATH="/Users/<you>/Library/Python/2.7/bin:$PATH"

That's where pip installs the executables.

Tip: For non-default python version which python to find the location of your python installation and replace that portion in the path above. (Thanks for the hint Sanket_Diwale)

unique() for more than one variable

This is an addition to Josh's answer.

You can also keep the values of other variables while filtering out duplicated rows in data.table

Example:

library(data.table)

#create data table
dt <- data.table(
  V1=LETTERS[c(1,1,1,1,2,3,3,5,7,1)],
  V2=LETTERS[c(2,3,4,2,1,4,4,6,7,2)],
  V3=c(1),
  V4=c(2) )

> dt
# V1 V2 V3 V4
# A  B  1  2
# A  C  1  2
# A  D  1  2
# A  B  1  2
# B  A  1  2
# C  D  1  2
# C  D  1  2
# E  F  1  2
# G  G  1  2
# A  B  1  2

# set the key to all columns
setkey(dt)

# Get Unique lines in the data table
unique( dt[list(V1, V2), nomatch = 0] ) 

# V1 V2 V3 V4
# A  B  1  2
# A  C  1  2
# A  D  1  2
# B  A  1  2
# C  D  1  2
# E  F  1  2
# G  G  1  2

Alert: If there are different combinations of values in the other variables, then your result will be

unique combination of V1 and V2

How to load URL in UIWebView in Swift?

in swift 5

import UIKit
import WebKit
class ViewController: UIViewController, WKUIDelegate {
   var webView: WKWebView!
   override func viewDidLoad() {
      super.viewDidLoad()
      let myURL = URL(string:"https://www.apple.com")
      let myRequest = URLRequest(url: myURL!)
      webView.load(myRequest)
   }
   override func loadView() {
      let webConfiguration = WKWebViewConfiguration()
      webView = WKWebView(frame: .zero, configuration: webConfiguration)
      webView.uiDelegate = self
      view = webView
   }
}

SELECT FOR UPDATE with SQL Server

You cannot have snapshot isolation and blocking reads at the same time. The purpose of snapshot isolation is to prevent blocking reads.

JavaScript Array to Set

By definition "A Set is a collection of values, where each value may occur only once." So, if your array has repeated values then only one value among the repeated values will be added to your Set.

var arr = [1, 2, 3];
var set = new Set(arr);
console.log(set); // {1,2,3}


var arr = [1, 2, 1];
var set = new Set(arr);
console.log(set); // {1,2}

So, do not convert to set if you have repeated values in your array.

Read text from response

I've just tried that myself, and it gave me a 200 OK response, but no content - the content length was 0. Are you sure it's giving you content? Anyway, I'll assume that you've really got content.

Getting actual text back relies on knowing the encoding, which can be tricky. It should be in the Content-Type header, but then you've got to parse it etc.

However, if this is actually XML (e.g. from "http://google.com/xrds/xrds.xml"), it's a lot easier. Just load the XML into memory, e.g. via LINQ to XML. For example:

using System;
using System.IO;
using System.Net;
using System.Xml.Linq;
using System.Web;

class Test
{
    static void Main()
    {
        string url = "http://google.com/xrds/xrds.xml";
        HttpWebRequest request = (HttpWebRequest) WebRequest.Create(url);

        XDocument doc;
        using (WebResponse response = request.GetResponse())
        {
            using (Stream stream = response.GetResponseStream())
            {
                doc = XDocument.Load(stream);
            }
        }
        // Now do whatever you want with doc here
        Console.WriteLine(doc);
    }   
}

If the content is XML, getting the result into an XML object model (whether it's XDocument, XmlDocument or XmlReader) is likely to be more valuable than having the plain text.

How to make custom error pages work in ASP.NET MVC 4

I do something that requires less coding than the other solutions posted.

First, in my web.config, I have the following:

<customErrors mode="On" defaultRedirect="~/ErrorPage/Oops">
   <error redirect="~/ErrorPage/Oops/404" statusCode="404" />
   <error redirect="~/ErrorPage/Oops/500" statusCode="500" />
</customErrors>

And the controller (/Controllers/ErrorPageController.cs) contains the following:

public class ErrorPageController : Controller
{
    public ActionResult Oops(int id)
    {
        Response.StatusCode = id;

        return View();
    }
}

And finally, the view contains the following (stripped down for simplicity, but it can conta:

_x000D_

@{ ViewBag.Title = "Oops! Error Encountered"; }_x000D_
_x000D_
<section id="Page">_x000D_
  <div class="col-xs-12 well">_x000D_
    <table cellspacing="5" cellpadding="3" style="background-color:#fff;width:100%;" class="table-responsive">_x000D_
      <tbody>_x000D_
        <tr>_x000D_
          <td valign="top" align="left" id="tableProps">_x000D_
            <img width="25" height="33" src="~/Images/PageError.gif" id="pagerrorImg">_x000D_
          </td>_x000D_
          <td width="360" valign="middle" align="left" id="tableProps2">_x000D_
            <h1 style="COLOR: black; FONT: 13pt/15pt verdana" id="errortype"><span id="errorText">@Response.Status</span></h1>_x000D_
          </td>_x000D_
        </tr>_x000D_
        <tr>_x000D_
          <td width="400" colspan="2" id="tablePropsWidth"><font style="COLOR: black; FONT: 8pt/11pt verdana">Possible causes:</font>_x000D_
          </td>_x000D_
        </tr>_x000D_
        <tr>_x000D_
          <td width="400" colspan="2" id="tablePropsWidth2">_x000D_
            <font style="COLOR: black; FONT: 8pt/11pt verdana" id="LID1">_x000D_
                            <hr>_x000D_
                            <ul>_x000D_
                                <li id="list1">_x000D_
                                    <span class="infotext">_x000D_
                                        <strong>Baptist explanation: </strong>There_x000D_
                                        must be sin in your life. Everyone else opened it fine.<br>_x000D_
                                    </span>_x000D_
                                </li>_x000D_
                                <li>_x000D_
                                    <span class="infotext">_x000D_
                                        <strong>Presbyterian explanation: </strong>It's_x000D_
                                        not God's will for you to open this link.<br>_x000D_
                                    </span>_x000D_
                                </li>_x000D_
                                <li>_x000D_
                                    <span class="infotext">_x000D_
                                        <strong> Word of Faith explanation:</strong>_x000D_
                                        You lack the faith to open this link. Your negative words have prevented_x000D_
                                        you from realizing this link's fulfillment.<br>_x000D_
                                    </span>_x000D_
                                </li>_x000D_
                                <li>_x000D_
                                    <span class="infotext">_x000D_
                                        <strong>Charismatic explanation: </strong>Thou_x000D_
                                        art loosed! Be commanded to OPEN!<br>_x000D_
                                    </span>_x000D_
                                </li>_x000D_
                                <li>_x000D_
                                    <span class="infotext">_x000D_
                                        <strong>Unitarian explanation:</strong> All_x000D_
                                        links are equal, so if this link doesn't work for you, feel free to_x000D_
                                        experiment with other links that might bring you joy and fulfillment.<br>_x000D_
                                    </span>_x000D_
                                </li>_x000D_
                                <li>_x000D_
                                    <span class="infotext">_x000D_
                                        <strong>Buddhist explanation:</strong> .........................<br>_x000D_
                                    </span>_x000D_
                                </li>_x000D_
                                <li>_x000D_
                                    <span class="infotext">_x000D_
                                        <strong>Episcopalian explanation:</strong>_x000D_
                                        Are you saying you have something against homosexuals?<br>_x000D_
                                    </span>_x000D_
                                </li>_x000D_
                                <li>_x000D_
                                    <span class="infotext">_x000D_
                                        <strong>Christian Science explanation: </strong>There_x000D_
                                        really is no link.<br>_x000D_
                                    </span>_x000D_
                                </li>_x000D_
                                <li>_x000D_
                                    <span class="infotext">_x000D_
                                        <strong>Atheist explanation: </strong>The only_x000D_
                                        reason you think this link exists is because you needed to invent it.<br>_x000D_
                                    </span>_x000D_
                                </li>_x000D_
                                <li>_x000D_
                                    <span class="infotext">_x000D_
                                        <strong>Church counselor's explanation:</strong>_x000D_
                                        And what did you feel when the link would not open?_x000D_
                                    </span>_x000D_
                                </li>_x000D_
                            </ul>_x000D_
                            <p>_x000D_
                                <br>_x000D_
                            </p>_x000D_
                            <h2 style="font:8pt/11pt verdana; color:black" id="ietext">_x000D_
                                <img width="16" height="16" align="top" src="~/Images/Search.gif">_x000D_
                                HTTP @Response.StatusCode - @Response.StatusDescription <br>_x000D_
                            </h2>_x000D_
                        </font>_x000D_
          </td>_x000D_
        </tr>_x000D_
      </tbody>_x000D_
    </table>_x000D_
  </div>_x000D_
</section>

_x000D_

It's just as simple as that. It could be easily extended to offer more detailed error info, but ELMAH handles that for me & the statusCode & statusDescription is all that I usually need.

When should an Excel VBA variable be killed or set to Nothing?

VB6/VBA uses deterministic approach to destoying objects. Each object stores number of references to itself. When the number reaches zero, the object is destroyed.

Object variables are guaranteed to be cleaned (set to Nothing) when they go out of scope, this decrements the reference counters in their respective objects. No manual action required.

There are only two cases when you want an explicit cleanup:

When you want an object to be destroyed before its variable goes out of scope (e.g., your procedure is going to take long time to execute, and the object holds a resource, so you want to destroy the object as soon as possible to release the resource).
When you have a circular reference between two or more objects.

If objectA stores a references to objectB, and objectB stores a reference to objectA, the two objects will never get destroyed unless you brake the chain by explicitly setting objectA.ReferenceToB = Nothing or objectB.ReferenceToA = Nothing.

The code snippet you show is wrong. No manual cleanup is required. It is even harmful to do a manual cleanup, as it gives you a false sense of more correct code.

If you have a variable at a class level, it will be cleaned/destroyed when the class instance is destructed. You can destroy it earlier if you want (see item 1.).

If you have a variable at a module level, it will be cleaned/destroyed when your program exits (or, in case of VBA, when the VBA project is reset). You can destroy it earlier if you want (see item 1.).

Access level of a variable (public vs. private) does not affect its life time.

Add characters to a string in Javascript

simply used the + operator. Javascript concats strings with +

Using ADB to capture the screen

To save to a file on Windows, OSX and Linux

adb exec-out screencap -p > screen.png

To copy to clipboard on Linux use

adb exec-out screencap -p | xclip -t image/png

Java regex email

Don't. You will never end up with a valid expression.

For example these are all valid email addresses:

"Abc\@def"@example.com
"Fred Bloggs"@example.com
"Joe\\Blow"@example.com
"Abc@def"@example.com
customer/department=shipping@examp le.com
[email protected]
!def!xyz%[email protected]
[email protected]
matteo(this is a comment)[email protected]
root@[127.0.0.1]

Just to mention a few problems:

you don't consider the many forms of specifying a host (e.g, by the IP address)
you miss valid characters
you miss non ASCII domain names

Before even beginning check the corresponding RFCs

Windows batch: formatted date into variable

It is possible to use PowerShell and redirect its output to an environment variable by using a loop.

From the command line (cmd):

for /f "tokens=*" %a in ('powershell get-date -format "{yyyy-MM-dd+HH:mm}"') do set td=%a

echo %td%
2016-25-02+17:25

In a batch file you might escape %a as %%a:

for /f "tokens=*" %%a in ('powershell get-date -format "{yyyy-MM-dd+HH:mm}"') do set td=%%a

How to change the default GCC compiler in Ubuntu?

As @Tommy suggested, you should use update-alternatives.
It assigns values to every software of a family, so that it defines the order in which the applications will be called.

It is used to maintain different versions of the same software on a system. In your case, you will be able to use several declinations of gcc, and one will be favoured.

To figure out the current priorities of gcc, type in the command pointed out by @tripleee's comment:

update-alternatives --query gcc

Now, note the priority attributed to gcc-4.4 because you'll need to give a higher one to gcc-3.3.
To set your alternatives, you should have something like this (assuming your gcc installation is located at /usr/bin/gcc-3.3, and gcc-4.4's priority is less than 50):

update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-3.3 50

--edit--

Finally, you can also use the interactive interface of update-alternatives to easily switch between versions. Type update-alternatives --config gcc to be asked to choose the gcc version you want to use among those installed.

--edit 2 --

Now, to fix the CXX environment variable systemwide, you need to put the line indicated by @DipSwitch's in your .bashrc file (this will apply the change only for your user, which is safer in my opinion):

echo 'export CXX=/usr/bin/gcc-3.3' >> ~/.bashrc

How to get the day of week and the month of the year?

As @L-Ray has already suggested, you can look into moment.js as well

Sample

_x000D_

var today = moment();
var result = {
  day: today.format("dddd"),
  month: today.format("MMM")
}

document.write("<pre>" + JSON.stringify(result,0,4) + "</pre>");

_x000D_

<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.13.0/moment.min.js"></script>

_x000D_

Initialize Array of Objects using NSArray

No one commenting on the randomAge method?

This is so awfully wrong, it couldn't be any wronger.

NSInteger is a primitive type - it is most likely typedef'd as int or long. In the randomAge method, you calculate a number from about 1 to 98.

Then you can cast that number to an NSNumber. You had to add a cast because the compiler gave you a warning that you didn't understand. That made the warning go away, but left you with an awful bug: That number was forced to be a pointer, so now you have a pointer to an integer somewhere in the first 100 bytes of memory.

If you access an NSInteger through the pointer, your program will crash. If you write through the pointer, your program will crash. If you put it into an array or dictionary, your program will crash.

Change it either to NSInteger or int, which is probably the best, or to NSNumber if you need an object for some reason. Then create the object by calling [NSNumber numberWithInteger:99] or whatever number you want.

Programs & Examples On #Tcldevkit

editing PATH variable on mac

How to loop through all but the last item of a list?

Text editor to open big (giant, huge, large) text files

Tips and tricks

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Perl

logparser

The relativity of sizes

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