Draw on HTML5 Canvas using a mouse

It's been years since the question was asked and was answered.

For anyone who looks for a simple drawing canvas (eg, for taking the signature from the user/customer), here I am posting a more simplified jquery version of the currently accepted answer

_x000D_

$(document).ready(function() {_x000D_
  var flag, dot_flag = false,_x000D_
 prevX, prevY, currX, currY = 0,_x000D_
 color = 'black', thickness = 2;_x000D_
  var $canvas = $('#canvas');_x000D_
  var ctx = $canvas[0].getContext('2d');_x000D_
_x000D_
  $canvas.on('mousemove mousedown mouseup mouseout', function(e) {_x000D_
    prevX = currX;_x000D_
    prevY = currY;_x000D_
    currX = e.clientX - $canvas.offset().left;_x000D_
    currY = e.clientY - $canvas.offset().top;_x000D_
    if (e.type == 'mousedown') {_x000D_
      flag = true;_x000D_
    }_x000D_
    if (e.type == 'mouseup' || e.type == 'mouseout') {_x000D_
      flag = false;_x000D_
    }_x000D_
    if (e.type == 'mousemove') {_x000D_
      if (flag) {_x000D_
        ctx.beginPath();_x000D_
        ctx.moveTo(prevX, prevY);_x000D_
        ctx.lineTo(currX, currY);_x000D_
        ctx.strokeStyle = color;_x000D_
        ctx.lineWidth = thickness;_x000D_
        ctx.stroke();_x000D_
        ctx.closePath();_x000D_
      }_x000D_
    }_x000D_
  });_x000D_
_x000D_
  $('.canvas-clear').on('click', function(e) {_x000D_
    c_width = $canvas.width();_x000D_
    c_height = $canvas.height();_x000D_
    ctx.clearRect(0, 0, c_width, c_height);_x000D_
    $('#canvasimg').hide();_x000D_
  });_x000D_
});

_x000D_

<html>_x000D_
  <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.0/jquery.min.js"></script>_x000D_
  <body>_x000D_
    <canvas id="canvas" width="400" height="400" style="position:absolute;top:10%;left:10%;border:2px solid;"></canvas>_x000D_
    <input type="button" value="Clear" class="canvas-clear" />_x000D_
  </body>_x000D_
</html>

_x000D_

Extract first item of each sublist

lst = [['a','b','c'], [1,2,3], ['x','y','z']]
outputlist = []
for values in lst:
    outputlist.append(values[0])

print(outputlist)

Output: ['a', 1, 'x']

How can I increase a scrollbar's width using CSS?

This can be done in WebKit-based browsers (such as Chrome and Safari) with only CSS:

::-webkit-scrollbar {
    width: 2em;
    height: 2em
}
::-webkit-scrollbar-button {
    background: #ccc
}
::-webkit-scrollbar-track-piece {
    background: #888
}
::-webkit-scrollbar-thumb {
    background: #eee
}?

JSFiddle Demo

References:

MD5 is 128 bits but why is it 32 characters?

A hex "character" (nibble) is different from a "character"

To be clear on the bits vs byte, vs characters.

1 byte is 8 bits (for our purposes)
8 bits provides 2**8 possible combinations: 256 combinations

When you look at a hex character,

16 combinations of [0-9] + [a-f]: the full range of 0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f
16 is less than 256, so one one hex character does not store a byte.
16 is 2**4: that means one hex character can store 4 bits in a byte (half a byte).
Therefore, two hex characters, can store 8 bits, 2**8 combinations.
A byte represented as a hex character is [0-9a-f][0-9a-f] and that represents both halfs of a byte (we call a half-byte a nibble).

When you look at a regular single-byte character, (we're totally going to skip multi-byte and wide-characters here)

It can store far more than 16 combinations.
The capabilities of the character are determined by the encoding. For instance, the ISO 8859-1 that stores an entire byte, stores all this stuff
All that stuff takes the entire 2**8 range.
If a hex-character in an md5() could store all that, you'd see all the lowercase letters, all the uppercase letters, all the punctuation and things like ¡°ÀÐàð, whitespace like (newlines, and tabs), and control characters (which you can't even see and many of which aren't in use).

So they're clearly different and I hope that provides the best break down of the differences.

How many threads is too many?

ryeguy, I am currently developing a similar application and my threads number is set to 15. Unfortunately if I increase it at 20, it crashes. So, yes, I think the best way to handle this is to measure whether or not your current configuration allows more or less than a number X of threads.

How do I handle newlines in JSON?

You could just escape your string on the server when writing the value of the JSON field and unescape it when retrieving the value in the client browser, for instance.

The JavaScript implementation of all major browsers have the unescape command.

Example:

On the server:

response.write "{""field1"":""" & escape(RS_Temp("textField")) & """}"

In the browser:

document.getElementById("text1").value = unescape(jsonObject.field1)

How to format html table with inline styles to look like a rendered Excel table?

table {
  border-collapse:collapse;
}

How to count the number of lines of a string in javascript

I was testing out the speed of the functions, and I found consistently that this solution that I had written was much faster than matching. We check the new length of the string as compared to the previous length.

const lines = str.length - str.replace(/\n/g, "").length+1;

_x000D_

let str = `Line1
Line2
Line3`;
console.time("LinesTimer")
console.log("Lines: ",str.length - str.replace(/\n/g, "").length+1);
console.timeEnd("LinesTimer")

_x000D_

Html- how to disable <a href>?

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

That should do it hope I helped!

Get size of all tables in database

For get all table size in one database you can use this query :

Exec sys.sp_MSforeachtable ' sp_spaceused "?" '

And you can change it to insert all of result into temp table and after that select from temp table.

Insert into #TempTable Exec sys.sp_MSforeachtable ' sp_spaceused "?" ' 
Select * from #TempTable

How to delete the contents of a folder?

Use the method bellow to remove the contents of a directory, not the directory itself:

import os
import shutil

def remove_contents(path):
    for c in os.listdir(path):
        full_path = os.path.join(path, c)
        if os.path.isfile(full_path):
            os.remove(full_path)
        else:
            shutil.rmtree(full_path)

Get filename and path from URI from mediastore

Since the above answers didn't work for me, here is the solution that worked for me:

For both >19 and <=19 API Levels.

This method covers all the cases to get filePath from uri

/**
 * Get a file path from a Uri. This will get the the path for Storage Access
 * Framework Documents, as well as the _data field for the MediaStore and
 * other file-based ContentProviders.
 *
 * @param context The activity.
 * @param uri The Uri to query.
 * @author paulburke
 */
public static String getPath(final Context context, final Uri uri) {

    // DocumentProvider
    if ( Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT && DocumentsContract.isDocumentUri(context, uri)) {
        // ExternalStorageProvider
        if (isExternalStorageDocument(uri)) {
            final String docId = DocumentsContract.getDocumentId(uri);
            final String[] split = docId.split(":");
            final String type = split[0];

            if ("primary".equalsIgnoreCase(type)) {
                return Environment.getExternalStorageDirectory() + "/" + split[1];
            }else{
                Toast.makeText(context, "Could not get file path. Please try again", Toast.LENGTH_SHORT).show();
            }
        }
        // DownloadsProvider
        else if (isDownloadsDocument(uri)) {

            final String id = DocumentsContract.getDocumentId(uri);
            final Uri contentUri = ContentUris.withAppendedId(
                    Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

            return getDataColumn(context, contentUri, null, null);
        }
        // MediaProvider
        else if (isMediaDocument(uri)) {
            final String docId = DocumentsContract.getDocumentId(uri);
            final String[] split = docId.split(":");
            final String type = split[0];

            Uri contentUri = null;
            if ("image".equals(type)) {
                contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
            } else if ("video".equals(type)) {
                contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
            } else if ("audio".equals(type)) {
                contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
            } else {
                contentUri = MediaStore.Files.getContentUri("external");
            }

            final String selection = "_id=?";
            final String[] selectionArgs = new String[] {
                    split[1]
            };

            return getDataColumn(context, contentUri, selection, selectionArgs);
        }
    }
    // MediaStore (and general)
    else if ("content".equalsIgnoreCase(uri.getScheme())) {
        return getDataColumn(context, uri, null, null);
    }
    // File
    else if ("file".equalsIgnoreCase(uri.getScheme())) {
        return uri.getPath();
    }

    return null;
}

How to add an item to an ArrayList in Kotlin?

If you want to specifically use java ArrayList then you can do something like this:

fun initList(){
    val list: ArrayList<String> = ArrayList()
    list.add("text")
    println(list)
}

Otherwise @guenhter answer is the one you are looking for.

initialize a vector to zeros C++/C++11

You don't need initialization lists for that:

std::vector<int> vector1(length, 0);
std::vector<double> vector2(length, 0.0);

Querying Datatable with where condition

Something like this...

var res = from row in myDTable.AsEnumerable()
where row.Field<int>("EmpID") == 5 &&
(row.Field<string>("EmpName") != "abc" ||
row.Field<string>("EmpName") != "xyz")
select row;

How do I install Eclipse Marketplace in Eclipse Classic?

Help → Install new Software → Switch to the Kepler Repository → General Purpose Tools → Marketplace Client

If you use Eclipse Luna SR 1, the released Marketplace contains a bug; you have to install it from the Marketplace update site. This is fixed again in Luna SR 2.

Marketplace update site:

Luna - http://download.eclipse.org/mpc/luna
Helios - http://download.eclipse.org/releases/helios
Juno - http://download.eclipse.org/releases/juno
Mars - http://download.eclipse.org/releases/mars

Clear History and Reload Page on Login/Logout Using Ionic Framework

I was trying to do refresh page using angularjs when i saw websites i got confused but no code was working for the code then i got solution for reloading page using

$state.go('path',null,{reload:true});

use this in a function this will work.

Align DIV to bottom of the page

Nathan Lee's answer is perfect. I just wanted to add something about position:absolute;. If you wanted to use position:absolute; like you had in your code, you have to think of it as pushing it away from one side of the page.

For example, if you wanted your div to be somewhere in the bottom, you would have to use position:absolute; top:500px;. That would push your div 500px from the top of the page. Same rule applies for all other directions.

DEMO

'ng' is not recognized as an internal or external command, operable program or batch file

You should add the path where ng.cmd located. By default, it should be located on C:\Users\user\AppData\Roaming\npm

NB: Here "user" may vary as per your pc username!

Stop all active ajax requests in jQuery

The following snippet allows you to maintain a list (pool) of request and abort them all if needed. Best to place in the <HEAD> of your html, before any other AJAX calls are made.

<script type="text/javascript">
    $(function() {
        $.xhrPool = [];
        $.xhrPool.abortAll = function() {
            $(this).each(function(i, jqXHR) {   //  cycle through list of recorded connection
                jqXHR.abort();  //  aborts connection
                $.xhrPool.splice(i, 1); //  removes from list by index
            });
        }
        $.ajaxSetup({
            beforeSend: function(jqXHR) { $.xhrPool.push(jqXHR); }, //  annd connection to list
            complete: function(jqXHR) {
                var i = $.xhrPool.indexOf(jqXHR);   //  get index for current connection completed
                if (i > -1) $.xhrPool.splice(i, 1); //  removes from list by index
            }
        });
    })
</script>

Npm Error - No matching version found for

Try removing "package-lock.json" and running "npm install && npm update", it'll install the latest version and clear all errors.

"git rm --cached x" vs "git reset head --? x"?

Perhaps an example will help:

git rm --cached asd
git commit -m "the file asd is gone from the repository"

versus

git reset HEAD -- asd
git commit -m "the file asd remains in the repository"

Note that if you haven't changed anything else, the second commit won't actually do anything.

Difference between <input type='submit' /> and <button type='submit'>text</button>

Not sure where you get your legends from but:

Submit button with `<button>`

As with:

<button type="submit">(html content)</button>

IE6 will submit all text for this button between the tags, other browsers will only submit the value. Using <button> gives you more layout freedom over the design of the button. In all its intents and purposes, it seemed excellent at first, but various browser quirks make it hard to use at times.

In your example, IE6 will send text to the server, while most other browsers will send nothing. To make it cross-browser compatible, use <button type="submit" value="text">text</button>. Better yet: don't use the value, because if you add HTML it becomes rather tricky what is received on server side. Instead, if you must send an extra value, use a hidden field.

Button with `<input>`

As with:

<input type="button" />

By default, this does next to nothing. It will not even submit your form. You can only place text on the button and give it a size and a border by means of CSS. Its original (and current) intent was to execute a script without the need to submit the form to the server.

Normal submit button with `<input>`

As with:

<input type="submit" />

Like the former, but actually submits the surrounding form.

Image submit button with `<input>`

As with:

<input type="image" />

Like the former (submit), it will also submit a form, but you can use any image. This used to be the preferred way to use images as buttons when a form needed submitting. For more control, <button> is now used. This can also be used for server side image maps but that's a rarity these days. When you use the usemap-attribute and (with or without that attribute), the browser will send the mouse-pointer X/Y coordinates to the server (more precisely, the mouse-pointer location inside the button of the moment you click it). If you just ignore these extras, it is nothing more than a submit button disguised as an image.

There are some subtle differences between browsers, but all will submit the value-attribute, except for the <button> tag as explained above.

iOS for VirtualBox

Additional to the above - the QEMU website has good documentation about setting up an ARM based emulator: http://qemu.weilnetz.de/qemu-doc.html#ARM-System-emulator

"The import org.springframework cannot be resolved."

Finally my issue got resolved. I was importing the project as "Existing project into workspace". This was completely wrong. After that I selected "Existing Maven project" and after that some few hiccups and all errors were removed. In this process I got to learn so many things in Maven which are important for a new comer in Maven project.

How do I execute a PowerShell script automatically using Windows task scheduler?

You can use the Unblock-File cmdlet to unblock the execution of this specific script. This prevents you doing any permanent policy changes which you may not want due to security concerns.

Unblock-File path_to_your_script

Source: Unblock-File

Change window location Jquery

If you want to use the back button, check this out. https://stackoverflow.com/questions/116446/what-is-the-best-back-button-jquery-plugin

Use document.location.href to change the page location, place it in the function on a successful ajax run.

How to convert View Model into JSON object in ASP.NET MVC?

<htmltag id=’elementId’ data-ZZZZ’=’@Html.Raw(Json.Encode(Model))’ />

Refer https://highspeedlowdrag.wordpress.com/2014/08/23/mvc-data-to-jquery-data/

I did below and it works like charm.

<input id="hdnElement" class="hdnElement" type="hidden" value='@Html.Raw(Json.Encode(Model))'>

Swift GET request with parameters

I use:

let dictionary = ["method":"login_user",
                  "cel":mobile.text!
                  "password":password.text!] as  Dictionary<String,String>

for (key, value) in dictionary {
    data=data+"&"+key+"="+value
    }

request.HTTPBody = data.dataUsingEncoding(NSUTF8StringEncoding);

Format numbers in JavaScript similar to C#

May I suggest numbro for locale based formatting and number-format.js for the general case. A combination of the two depending on use-case may help.

How to read/process command line arguments?

Pocoo's click is more intuitive, requires less boilerplate, and is at least as powerful as argparse.

The only weakness I've encountered so far is that you can't do much customization to help pages, but that usually isn't a requirement and docopt seems like the clear choice when it is.

Bash: Syntax error: redirection unexpected

On my machine, if I run a script directly, the default is bash.

If I run it with sudo, the default is sh.

That’s why I was hitting this problem when I used sudo.

Trying to add adb to PATH variable OSX

2nd solution is explained below. But when i close the terminal the change which i made in path variable gets lost. Thus i prefer the first way!

Connection timeout for SQL server

Yes, you could append ;Connection Timeout=30 to your connection string and specify the value you wish.

The timeout value set in the Connection Timeout property is a time expressed in seconds. If this property isn't set, the timeout value for the connection is the default value (15 seconds).

Moreover, setting the timeout value to 0, you are specifying that your attempt to connect waits an infinite time. As described in the documentation, this is something that you shouldn't set in your connection string:

A value of 0 indicates no limit, and should be avoided in a ConnectionString because an attempt to connect waits indefinitely.

How do you validate a URL with a regular expression in Python?

The regex provided should match any url of the form http://www.ietf.org/rfc/rfc3986.txt; and does when tested in the python interpreter.

What format have the URLs you've been having trouble parsing had?

Combining two sorted lists in Python

is there a smarter way to do this in Python

This hasn't been mentioned, so I'll go ahead - there is a merge stdlib function in the heapq module of python 2.6+. If all you're looking to do is getting things done, this might be a better idea. Of course, if you want to implement your own, the merge of merge-sort is the way to go.

>>> list1 = [1, 5, 8, 10, 50]
>>> list2 = [3, 4, 29, 41, 45, 49]
>>> from heapq import merge
>>> list(merge(list1, list2))
[1, 3, 4, 5, 8, 10, 29, 41, 45, 49, 50]

Here's the documentation.

How to insert an object in an ArrayList at a specific position

This method Appends the specified element to the end of this list.

add(E e) //append element to the end of the arraylist.

This method Inserts the specified element at the specified position in this list.

void add(int index, E element) //inserts element at the given position in the array list.

This method Replaces the element at the specified position in this list with the specified element.

set(int index, E element) //Replaces the element at the specified position in this list with the specified element.

Android Studio Stuck at Gradle Download on create new project

Yes, There is.

Create a new project and you should Shutdown The Android Studio Application.(Because it takes a long time for you).
Goto C:\Users\{Logged in User}\.gradle folder
There is a folder there that show you which version of gradle Android Studio requires (e.g. gradle-1.8-bin)
Download this version from internet (e.g. gradle-1.8-bin.zip).
Goto C:\Users\{Logged in User}\.gradle\wrapper\dists\gradle-1.8-bin
There is a folder here that its name is like a GUID.
You should just copy the zip file that you've already downloaded from internet into this folder.
Execute Android Studio and create a new project.

Simple DateTime sql query

Others have already said that date literals in SQL Server require being surrounded with single quotes, but I wanted to add that you can solve your month/day mixup problem two ways (that is, the problem where 25 is seen as the month and 5 the day) :

Use an explicit Convert(datetime, 'datevalue', style) where style is one of the numeric style codes, see Cast and Convert. The style parameter isn't just for converting dates to strings but also for determining how strings are parsed to dates.
Use a region-independent format for dates stored as strings. The one I use is 'yyyymmdd hh:mm:ss', or consider ISO format, yyyy-mm-ddThh:mi:ss.mmm. Based on experimentation, there are NO other language-invariant format string. (Though I think you can include time zone at the end, see the above link).

What is the most compatible way to install python modules on a Mac?

I use easy_install with Apple's Python, and it works like a charm.

What do 1.#INF00, -1.#IND00 and -1.#IND mean?

For anyone wondering about the difference between -1.#IND00 and -1.#IND (which the question specifically asked, and none of the answers address):

-1.#IND00

This specifically means a non-zero number divided by zero, e.g. 3.14 / 0 (source)

-1.#IND (a synonym for NaN)

This means one of four things (see wiki from source):

1) sqrt or log of a negative number

2) operations where both variables are 0 or infinity, e.g. 0 / 0

3) operations where at least one variable is already NaN, e.g. NaN * 5

4) out of range trig, e.g. arcsin(2)

BeautifulSoup: extract text from anchor tag

This will help:

from bs4 import BeautifulSoup

data = '''<div class="image">
        <a href="http://www.example.com/eg1">Content1<img  
        src="http://image.example.com/img1.jpg" /></a>
        </div>
        <div class="image">
        <a href="http://www.example.com/eg2">Content2<img  
        src="http://image.example.com/img2.jpg" /> </a>
        </div>'''

soup = BeautifulSoup(data)

for div in soup.findAll('div', attrs={'class':'image'}):
    print(div.find('a')['href'])
    print(div.find('a').contents[0])
    print(div.find('img')['src'])

If you are looking into Amazon products then you should be using the official API. There is at least one Python package that will ease your scraping issues and keep your activity within the terms of use.

What is the Angular equivalent to an AngularJS $watch?

This does not answer the question directly, but I have on different occasions landed on this Stack Overflow question in order to solve something I would use $watch for in angularJs. I ended up using another approach than described in the current answers, and want to share it in case someone finds it useful.

The technique I use to achieve something similar $watch is to use a BehaviorSubject (more on the topic here) in an Angular service, and let my components subscribe to it in order to get (watch) the changes. This is similar to a $watch in angularJs, but require some more setup and understanding.

In my component:

export class HelloComponent {
  name: string;
  // inject our service, which holds the object we want to watch.
  constructor(private helloService: HelloService){
    // Here I am "watching" for changes by subscribing
    this.helloService.getGreeting().subscribe( greeting => {
      this.name = greeting.value;
    });
  }
}

In my service

export class HelloService {
  private helloSubject = new BehaviorSubject<{value: string}>({value: 'hello'});
  constructor(){}
  // similar to using $watch, in order to get updates of our object 
  getGreeting(): Observable<{value:string}> {
    return this.helloSubject;
  }
  // Each time this method is called, each subscriber will receive the updated greeting.
  setGreeting(greeting: string) {
    this.helloSubject.next({value: greeting});
  }
}

Here is a demo on Stackblitz

How to handle change of checkbox using jQuery?

You can use Id of the field as well

$('#checkbox1').change(function() {
   if($(this).is(":checked")) {
      //'checked' event code
      return;
   }
   //'unchecked' event code
});

Get text of label with jquery

Try this

var g = $('#<%=Label1.ClientID%>').text();

Is <div style="width: ;height: ;background: "> CSS?

For example :

_x000D_

<div style="height:100px; width:100px; background:#000000"></div>

_x000D_

here.

you give css to div of height and width having 100px and background as black.

PS : try to avoid inline-css you can make external CSS and import in your html file.

you can refer here for CSS

hope this helps.

Encoding Error in Panda read_csv

This works in Mac as well you can use

df= pd.read_csv('Region_count.csv', encoding ='latin1')

Vertically align text within input field of fixed-height without display: table or padding?

I ran into this problem myself. I found that not specifying an input height, but using the font-height and padding combined, results in vertically aligned text.

For instance, lets say you want to have a 42px tall input box, with a font-size of 20px. You could simply find the difference between the input height and the font-size, divide it by two, and set your padding to that amount. In this case, you would have 22px total worth of padding, which is 11px on each side.

<input type="text" style="padding: 11px 0px 11px 0px; font-size: 20px;" />

That would give you a 42px tall input box with perfect vertical alignment.

Hope that helps.

How to assign string to bytes array

For example,

package main

import "fmt"

func main() {
    s := "abc"
    var a [20]byte
    copy(a[:], s)
    fmt.Println("s:", []byte(s), "a:", a)
}

Output:

s: [97 98 99] a: [97 98 99 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]

How to execute .sql script file using JDBC

You should be able to parse the SQL file into statements. And run a single statement a time. If you know that your file consists of simple insert/update/delete statements you can use a semicolon as statement delimiter. In common case you have a task to create your specific SQL-dialect parser.

Pyspark: display a spark data frame in a table format

The show method does what you're looking for.

For example, given the following dataframe of 3 rows, I can print just the first two rows like this:

df = sqlContext.createDataFrame([("foo", 1), ("bar", 2), ("baz", 3)], ('k', 'v'))
df.show(n=2)

which yields:

+---+---+
|  k|  v|
+---+---+
|foo|  1|
|bar|  2|
+---+---+
only showing top 2 rows

How get value from URL

You can also get a query string value as:

$uri =  $_SERVER["REQUEST_URI"]; //it will print full url
$uriArray = explode('/', $uri); //convert string into array with explode
$id = $uriArray[1]; //Print first array value

Adding and removing extensionattribute to AD object

To clear the value you can always reset it to $Null. For example:

Set-Mailbox -Identity "username" -CustomAttribute1 $Null

ORA-00932: inconsistent datatypes: expected - got CLOB

I found that selecting a clob column in CTE caused this explosion. ie

with cte as (
    select
        mytable1.myIntCol,
        mytable2.myClobCol
    from mytable1
    join mytable2 on ...
)
select myIntCol, myClobCol
from cte
where ...

presumably because oracle can't handle a clob in a temporary table.

Because my values were longer than 4K, I couldn't use to_char().
My work around was to select it from the final select, ie

with cte as (
    select
        mytable1.myIntCol
    from mytable1
)
select myIntCol, myClobCol
from cte
join mytable2 on ...
where ...

Too bad if this causes a performance problem.

Why is visible="false" not working for a plain html table?

Use display: none instead. Besides, this is probably what you need, because this also truncates the page by removing the space the table occupies, whereas visibility: hidden leaves the white space left by the table.

What are all the uses of an underscore in Scala?

Here are some more examples where _ is used:

val nums = List(1,2,3,4,5,6,7,8,9,10)

nums filter (_ % 2 == 0)

nums reduce (_ + _)

nums.exists(_ > 5)

nums.takeWhile(_ < 8)

In all above examples one underscore represents an element in the list (for reduce the first underscore represents the accumulator)

How to round up value C# to the nearest integer?

Use a function in place of MidpointRounding.AwayFromZero:

myRound(1.11125,4)

Answer:- 1.1114

public static Double myRound(Double Value, int places = 1000)
{
    Double myvalue = (Double)Value;
    if (places == 1000)
    {
        if (myvalue - (int)myvalue == 0.5)
        {
            myvalue = myvalue + 0.1;
            return (Double)Math.Round(myvalue);
        }
        return (Double)Math.Round(myvalue);
        places = myvalue.ToString().Substring(myvalue.ToString().IndexOf(".") + 1).Length - 1;
    } if ((myvalue * Math.Pow(10, places)) - (int)(myvalue * Math.Pow(10, places)) > 0.49)
    {
        myvalue = (myvalue * Math.Pow(10, places + 1)) + 1;
        myvalue = (myvalue / Math.Pow(10, places + 1));
    }
    return (Double)Math.Round(myvalue, places);
}

Computing cross-correlation function?

If you are looking for a rapid, normalized cross correlation in either one or two dimensions I would recommend the openCV library (see ~~http://opencv.willowgarage.com/wiki/~~ http://opencv.org/). The cross-correlation code maintained by this group is the fastest you will find, and it will be normalized (results between -1 and 1).

While this is a C++ library the code is maintained with CMake and has python bindings so that access to the cross correlation functions is convenient. OpenCV also plays nicely with numpy. If I wanted to compute a 2-D cross-correlation starting from numpy arrays I could do it as follows.

import numpy
import cv

#Create a random template and place it in a larger image
templateNp = numpy.random.random( (100,100) )
image = numpy.random.random( (400,400) )
image[:100, :100] = templateNp

#create a numpy array for storing result
resultNp = numpy.zeros( (301, 301) )

#convert from numpy format to openCV format
templateCv = cv.fromarray(numpy.float32(template))
imageCv = cv.fromarray(numpy.float32(image))
resultCv =  cv.fromarray(numpy.float32(resultNp))

#perform cross correlation
cv.MatchTemplate(templateCv, imageCv, resultCv, cv.CV_TM_CCORR_NORMED)

#convert result back to numpy array
resultNp = np.asarray(resultCv)

For just a 1-D cross-correlation create a 2-D array with shape equal to (N, 1 ). Though there is some extra code involved to convert to an openCV format the speed-up over scipy is quite impressive.

Why would $_FILES be empty when uploading files to PHP?

Here's a check-list for file uploading in PHP:

Check php.ini for:
file_uploads = On
post_max_size = 100M
upload_max_filesize = 100M
- You might need to use .htaccess or .user.ini if you are on shared hosting and don't have access to php.ini.
- Make sure you’re editing the correct ini file – use the phpinfo() function to verify your settings are actually being applied.
- Also make sure you don’t misspell the sizes - it should be 100M not 100MB.
Make sure your <form> tag has the enctype="multipart/form-data" attribute. No other tag will work, it has to be your FORM tag. Double check that it is spelled correctly. Double check that multipart/form-data is surrounded by STRAIGHT QUOTES, not smart quotes pasted in from Word OR from a website blog (WordPress converts straight quotes to angle quotes!). If you have multiple forms on the page, make sure they both have this attribute. Type them in manually, or try straight single quotes typed in manually.
Make sure you do not have two input file fields with the same name attribute. If you need to support multiple, put square brackets at the end of the name:
```
<input type="file" name="files[]">
<input type="file" name="files[]">
```
Make sure your tmp and upload directories have the correct read+write permissions set. The temporary upload folder is specified in PHP settings as upload_tmp_dir.
Make sure your file destination and tmp/upload directories do not have spaces in them.
Make sure all <form>'s on your page have </form> close tags.
Make sure your FORM tag has method="POST". GET requests do not support multipart/form-data uploads.
Make sure your file input tag has a NAME attribute. An ID attribute is NOT sufficient! ID attributes are for use in the DOM, not for POST payloads.
Make sure you are not using Javascript to disable your <input type="file"> field on submission
Make sure you're not nesting forms like <form><form></form></form>
Check your HTML structure for invalid/overlapping tags like <div><form></div></form>
Also make sure that the file you are uploading does not have any non-alphanumeric characters in it.
Once, I just spent hours trying to figure out why this was happening to me all of a sudden. It turned out that I had modified some of the PHP settings in .htaccess, and one of them (not sure which yet) was causing the upload to fail and $_FILES to be empty.
You could potentially try avoiding underscores (_) in the name="" attribute of the <input> tag
Try uploading very small files to narrow down whether it's a file-size issue.
Check your available disk space. Although very rare, it is mentioned in this PHP Manual page comment:

If the $_FILES array suddenly goes mysteriously empty, even though your form seems correct, you should check the disk space available for your temporary folder partition. In my installation, all file uploads failed without warning. After much gnashing of teeth, I tried freeing up additional space, after which file uploads suddenly worked again.
Be sure that you're not submitting the form through an AJAX POST request instead of a normal POST request that causes a page to reload. I went through each and every point in the list above, and finally found out that the reason due to which my $_FILES variable was empty was that I was submitting the form using an AJAX POST request. I know that there are methods to upload files using ajax too, but this could be a valid reason why your $_FILES array is empty.

Source for some of these points:
http://getluky.net/2004/10/04/apachephp-_files-array-mysteriously-empty/

Erasing elements from a vector

Use the remove/erase idiom:

std::vector<int>& vec = myNumbers; // use shorter name
vec.erase(std::remove(vec.begin(), vec.end(), number_in), vec.end());

What happens is that remove compacts the elements that differ from the value to be removed (number_in) in the beginning of the vector and returns the iterator to the first element after that range. Then erase removes these elements (whose value is unspecified).

How to map and remove nil values in Ruby

You could use compact:

[1, nil, 3, nil, nil].compact
=> [1, 3]

I'd like to remind people that if you're getting an array containing nils as the output of a map block, and that block tries to conditionally return values, then you've got code smell and need to rethink your logic.

For instance, if you're doing something that does this:

[1,2,3].map{ |i|
  if i % 2 == 0
    i
  end
}
# => [nil, 2, nil]

Then don't. Instead, prior to the map, reject the stuff you don't want or select what you do want:

[1,2,3].select{ |i| i % 2 == 0 }.map{ |i|
  i
}
# => [2]

I consider using compact to clean up a mess as a last-ditch effort to get rid of things we didn't handle correctly, usually because we didn't know what was coming at us. We should always know what sort of data is being thrown around in our program; Unexpected/unknown data is bad. Anytime I see nils in an array I'm working on, I dig into why they exist, and see if I can improve the code generating the array, rather than allow Ruby to waste time and memory generating nils then sifting through the array to remove them later.

'Just my $%0.2f.' % [2.to_f/100]

Method call if not null in C#

A quick extension method:

    public static void IfNotNull<T>(this T obj, Action<T> action, Action actionIfNull = null) where T : class {
        if(obj != null) {
            action(obj);
        } else if ( actionIfNull != null ) {
            actionIfNull();
        }
    }

example:

  string str = null;
  str.IfNotNull(s => Console.Write(s.Length));
  str.IfNotNull(s => Console.Write(s.Length), () => Console.Write("null"));

or alternatively:

    public static TR IfNotNull<T, TR>(this T obj, Func<T, TR> func, Func<TR> ifNull = null) where T : class {
        return obj != null ? func(obj) : (ifNull != null ? ifNull() : default(TR));
    }

example:

    string str = null;
    Console.Write(str.IfNotNull(s => s.Length.ToString());
    Console.Write(str.IfNotNull(s => s.Length.ToString(), () =>  "null"));

Sublime Text 2 - View whitespace characters

If you really only want to see trailing spaces, this ST2 plugin will do the trick: https://github.com/SublimeText/TrailingSpaces

Of Countries and their Cities

https://code.google.com/p/worlddb/downloads/list

Open World Database alpha

This database has multi languages country names, region names, city names and they's latitude and longitude number and country's alpha2 code .

Get all parameters from JSP page

Even though this is an old question, I had to do something similar today but I prefer JSTL:

<c:forEach var="par" items="${paramValues}">
    <c:if test="${fn:startsWith(par.key, 'question')}"> 
${par.key} = ${par.value[0]}; //whatever
    </c:if>
</c:forEach>

Correctly determine if date string is a valid date in that format

Validate with checkdate function:

$date = '2019-02-30';

$date_parts = explode( '-', $date );

if(checkdate( $date_parts[1], $date_parts[2], $date_parts[0] )){
    //date is valid
}else{
    //date is invalid
}

Default values and initialization in Java

In the first code sample, a is a main method local variable. Method local variables need to be initialized before using them.

In the second code sample, a is class member variable, hence it will be initialized to the default value.

How to export query result to csv in Oracle SQL Developer?

FYI, you can substitute the /*csv*/ for other formats as well including /*xml*/ and /*html*/. select /*xml*/ * from emp would return an xml document with the query results for example. I came across this article while looking for an easy way to return xml from a query.

How to create a .NET DateTime from ISO 8601 format

using System.Globalization;

DateTime d;
DateTime.TryParseExact(
    "2010-08-20T15:00:00",
    "s",
    CultureInfo.InvariantCulture,
    DateTimeStyles.AssumeUniversal, out d);

Adding value to input field with jQuery

You can simply use

 $(this).prev().val("hello world");

JSFiddle Demo

Check if a string is a palindrome

string test = "Malayalam";
            char[] palindrome = test.ToCharArray();
            char[] reversestring = new char[palindrome.Count()];
            for (int i = palindrome.Count() - 1; i >= 0; i--)
            {
                reversestring[palindrome.Count() - 1 - i] = palindrome[i];

            }

            string materializedString = new string(reversestring);

            if (materializedString.ToLower() == test.ToLower())
            {
                Console.Write("Palindrome!");
            }
            else
            {
                Console.Write("Not a Palindrome!");
            }

            Console.Read();

How to launch an EXE from Web page (asp.net)

In windows, specified protocol for application can be registered in Registry. In this msdn doc shows Registering an Application to a URI Scheme.

For example, an executable files 'alert.exe' is to be started. The following item can be registered.

HKEY_CLASSES_ROOT
   alert
      (Default) = "URL:Alert Protocol"
      URL Protocol = ""
      DefaultIcon
         (Default) = "alert.exe,1"
      shell
         open
            command
               (Default) = "C:\Program Files\Alert\alert.exe"

Then you can write a html to test

<head>
    <title>alter</title>
</head>

<body>
    <a href="alert:" >alert</a>
<body>

Extract filename and extension in Bash

Here is the algorithm I used for finding the name and extension of a file when I wrote a Bash script to make names unique when names conflicted with respect to casing.

#! /bin/bash 

#
# Finds 
# -- name and extension pairs
# -- null extension when there isn't an extension.
# -- Finds name of a hidden file without an extension
# 

declare -a fileNames=(
  '.Montreal' 
  '.Rome.txt' 
  'Loundon.txt' 
  'Paris' 
  'San Diego.txt'
  'San Francisco' 
  )

echo "Script ${0} finding name and extension pairs."
echo 

for theFileName in "${fileNames[@]}"
do
     echo "theFileName=${theFileName}"  

     # Get the proposed name by chopping off the extension
     name="${theFileName%.*}"

     # get extension.  Set to null when there isn't an extension
     # Thanks to mklement0 in a comment above.
     extension=$([[ "$theFileName" == *.* ]] && echo ".${theFileName##*.}" || echo '')

     # a hidden file without extenson?
     if [ "${theFileName}" = "${extension}" ] ; then
         # hidden file without extension.  Fixup.
         name=${theFileName}
         extension=""
     fi

     echo "  name=${name}"
     echo "  extension=${extension}"
done

The test run.

$ config/Name\&Extension.bash 
Script config/Name&Extension.bash finding name and extension pairs.

theFileName=.Montreal
  name=.Montreal
  extension=
theFileName=.Rome.txt
  name=.Rome
  extension=.txt
theFileName=Loundon.txt
  name=Loundon
  extension=.txt
theFileName=Paris
  name=Paris
  extension=
theFileName=San Diego.txt
  name=San Diego
  extension=.txt
theFileName=San Francisco
  name=San Francisco
  extension=
$

FYI: The complete transliteration program and more test cases can be found here: https://www.dropbox.com/s/4c6m0f2e28a1vxf/avoid-clashes-code.zip?dl=0

Javascript to sort contents of select element

Yes DOK has the right answer ... either pre-sort the results before you write the HTML (assuming it's dynamic and you are responsible for the output), or you write javascript.

The Javascript Sort method will be your friend here. Simply pull the values out of the select list, then sort it, and put them back :-)

Looping through a DataTable

If you want to change the contents of each and every cell in a datatable then we need to Create another Datatable and bind it as follows using "Import Row". If we don't create another table it will throw an Exception saying "Collection was Modified".

Consider the following code.

//New Datatable created which will have updated cells
DataTable dtUpdated = new DataTable();

//This gives similar schema to the new datatable
dtUpdated = dtReports.Clone();
foreach (DataRow row in dtReports.Rows)
{
    for (int i = 0; i < dtReports.Columns.Count; i++)
    {
        string oldVal = row[i].ToString();
        string newVal = "{"+oldVal;
        row[i] = newVal;
    }
    dtUpdated.ImportRow(row); 
}

This will have all the cells preceding with Paranthesis({)

jQuery first child of "this"

This can be done with a simple magic like this:

$(":first-child", element).toggleClass("redClass");

Reference: http://www.snoopcode.com/jquery/jquery-first-child-selector

Regular expression - starting and ending with a letter, accepting only letters, numbers and _

Here's a solution using a negative lookahead (not supported in all regex engines):

^[a-zA-Z](((?!__)[a-zA-Z0-9_])*[a-zA-Z0-9])?$

Test that it works as expected:

import re
tests = [
   ('a', True),
   ('_', False),
   ('zz', True),
   ('a0', True),
   ('A_', False),
   ('a0_b', True),
   ('a__b', False),
   ('a_1_c', True),
]

regex = '^[a-zA-Z](((?!__)[a-zA-Z0-9_])*[a-zA-Z0-9])?$'
for test in tests:
   is_match = re.match(regex, test[0]) is not None
   if is_match != test[1]:
       print "fail: "  + test[0]

Displaying a message in iOS which has the same functionality as Toast in Android

1) Download toast-notifications-ios from this link

2) go to Targets -> Build Phases and add -fno-objc-arc to the "compiler Sources" for relevant files

3) make a function and #import "iToast.h"

-(void)showToast :(NSString *)strMessage {
    iToast * objiTost = [iToast makeText:strMessage];
    [objiTost setFontSize:11];
    [objiTost setDuration:iToastDurationNormal];
    [objiTost setGravity:iToastGravityBottom];
    [objiTost show];
}

4) call where you need to display toast message

[self showToast:@"This is example text."];

How do I bind to list of checkbox values with AngularJS?

There are two ways to approach this problem. Either use a simple array or an array of objects. Each solution has it pros and cons. Below you'll find one for each case.

With a simple array as input data

The HTML could look like:

<label ng-repeat="fruitName in fruits">
  <input
    type="checkbox"
    name="selectedFruits[]"
    value="{{fruitName}}"
    ng-checked="selection.indexOf(fruitName) > -1"
    ng-click="toggleSelection(fruitName)"
  > {{fruitName}}
</label>

And the appropriate controller code would be:

app.controller('SimpleArrayCtrl', ['$scope', function SimpleArrayCtrl($scope) {

  // Fruits
  $scope.fruits = ['apple', 'orange', 'pear', 'naartjie'];

  // Selected fruits
  $scope.selection = ['apple', 'pear'];

  // Toggle selection for a given fruit by name
  $scope.toggleSelection = function toggleSelection(fruitName) {
    var idx = $scope.selection.indexOf(fruitName);

    // Is currently selected
    if (idx > -1) {
      $scope.selection.splice(idx, 1);
    }

    // Is newly selected
    else {
      $scope.selection.push(fruitName);
    }
  };
}]);

Pros: Simple data structure and toggling by name is easy to handle

Cons: Add/remove is cumbersome as two lists (the input and selection) have to be managed

With an object array as input data

The HTML could look like:

<label ng-repeat="fruit in fruits">
  <!--
    - Use `value="{{fruit.name}}"` to give the input a real value, in case the form gets submitted
      traditionally

    - Use `ng-checked="fruit.selected"` to have the checkbox checked based on some angular expression
      (no two-way-data-binding)

    - Use `ng-model="fruit.selected"` to utilize two-way-data-binding. Note that `.selected`
      is arbitrary. The property name could be anything and will be created on the object if not present.
  -->
  <input
    type="checkbox"
    name="selectedFruits[]"
    value="{{fruit.name}}"
    ng-model="fruit.selected"
  > {{fruit.name}}
</label>

And the appropriate controller code would be:

app.controller('ObjectArrayCtrl', ['$scope', 'filterFilter', function ObjectArrayCtrl($scope, filterFilter) {

  // Fruits
  $scope.fruits = [
    { name: 'apple',    selected: true },
    { name: 'orange',   selected: false },
    { name: 'pear',     selected: true },
    { name: 'naartjie', selected: false }
  ];

  // Selected fruits
  $scope.selection = [];

  // Helper method to get selected fruits
  $scope.selectedFruits = function selectedFruits() {
    return filterFilter($scope.fruits, { selected: true });
  };

  // Watch fruits for changes
  $scope.$watch('fruits|filter:{selected:true}', function (nv) {
    $scope.selection = nv.map(function (fruit) {
      return fruit.name;
    });
  }, true);
}]);

Pros: Add/remove is very easy

Cons: Somewhat more complex data structure and toggling by name is cumbersome or requires a helper method

Demo: http://jsbin.com/ImAqUC/1/

Retrieve CPU usage and memory usage of a single process on Linux?

ps aux | awk '{print $4"\t"$11}' | sort | uniq -c | awk '{print $2" "$1" "$3}' | sort -nr

or per process

ps aux | awk '{print $4"\t"$11}' | sort | uniq -c | awk '{print $2" "$1" "$3}' | sort -nr |grep mysql

Move all files except one

The following is not a 100% guaranteed method, and should not at all be attempted for scripting. But some times it is good enough for quick interactive shell usage. A file file glob like

[abc]*

(which will match all files with names starting with a, b or c) can be negated by inserting a "^" character first, i.e.

[^abc]*

I sometimes use this for not matching the "lost+found" directory, like for instance:

mv /mnt/usbdisk/[^l]* /home/user/stuff/.

Of course if there are other files starting with l I have to process those afterwards.

How to share data between different threads In C# using AOP?

When you start a thread you are executing a method of some chosen class. All attributes of that class are visible.

  Worker myWorker = new Worker( /* arguments */ );

  Thread myThread = new Thread(new ThreadStart(myWorker.doWork));

  myThread.Start();

Your thread is now in the doWork() method and can see any atrributes of myWorker, which may themselves be other objects. Now you just need to be careful to deal with the cases of having several threads all hitting those attributes at the same time.

Invoke or BeginInvoke cannot be called on a control until the window handle has been created

What about this :


    public static bool SafeInvoke( this Control control, MethodInvoker method )
    {
        if( control != null && ! control.IsDisposed && control.IsHandleCreated && control.FindForm().IsHandleCreated )
        {
            if( control.InvokeRequired )
            {
                control.Invoke( method );
            }
            else
            {
                method();
            }
            return true;
        }
        else return false;
    }

Get month name from date in Oracle

select to_char(sysdate, 'Month') from dual

in your example will be:

select to_char(to_date('15-11-2010', 'DD-MM-YYYY'), 'Month') from dual

How do I auto size a UIScrollView to fit its content

it depends on the content really : content.frame.height might give you what you want ? Depends if content is a single thing, or a collection of things.

Check if file is already open

If file is in use FileOutputStream fileOutputStream = new FileOutputStream(file); returns java.io.FileNotFoundException with 'The process cannot access the file because it is being used by another process' in the exception message.

What is the difference between a process and a thread?

Both threads and processes are atomic units of OS resource allocation (i.e. there is a concurrency model describing how CPU time is divided between them, and the model of owning other OS resources). There is a difference in:

Shared resources (threads are sharing memory by definition, they do not own anything except stack and local variables; processes could also share memory, but there is a separate mechanism for that, maintained by OS)
Allocation space (kernel space for processes vs. user space for threads)

Greg Hewgill above was correct about the Erlang meaning of the word "process", and here there's a discussion of why Erlang could do processes lightweight.

What is the parameter "next" used for in Express?

Before understanding next, you need to have a little idea of Request-Response cycle in node though not much in detail. It starts with you making an HTTP request for a particular resource and it ends when you send a response back to the user i.e. when you encounter something like res.send(‘Hello World’);

let’s have a look at a very simple example.

app.get('/hello', function (req, res, next) {
  res.send('USER')
})

Here we do not need next(), because resp.send will end the cycle and hand over the control back to the route middleware.

Now let’s take a look at another example.

app.get('/hello', function (req, res, next) {
  res.send("Hello World !!!!");
});

app.get('/hello', function (req, res, next) {
  res.send("Hello Planet !!!!");
});

Here we have 2 middleware functions for the same path. But you always gonna get the response from the first one. Because that is mounted first in the middleware stack and res.send will end the cycle.

But what if we always do not want the “Hello World !!!!” response back. For some conditions we may want the "Hello Planet !!!!" response. Let’s modify the above code and see what happens.

app.get('/hello', function (req, res, next) {
  if(some condition){
    next();
    return;
  }
  res.send("Hello World !!!!");  
});

app.get('/hello', function (req, res, next) {
  res.send("Hello Planet !!!!");
});

What’s the next doing here. And yes you might have gusses. It’s gonna skip the first middleware function if the condition is true and invoke the next middleware function and you will have the "Hello Planet !!!!" response.

So, next pass the control to the next function in the middleware stack.

What if the first middleware function does not send back any response but do execute a piece of logic and then you get the response back from second middleware function.

Something like below:-

app.get('/hello', function (req, res, next) {
  // Your piece of logic
  next();
});

app.get('/hello', function (req, res, next) {
  res.send("Hello !!!!");
});

In this case you need both the middleware functions to be invoked. So, the only way you reach the second middleware function is by calling next();

What if you do not make a call to next. Do not expect the second middleware function to get invoked automatically. After invoking the first function your request will be left hanging. The second function will never get invoked and you will not get back the response.

Do not want scientific notation on plot axis

You can use format or formatC to, ahem, format your axis labels.

For whole numbers, try

x <- 10 ^ (1:10)
format(x, scientific = FALSE)
formatC(x, digits = 0, format = "f")

If the numbers are convertable to actual integers (i.e., not too big), you can also use

formatC(x, format = "d")

How you get the labels onto your axis depends upon the plotting system that you are using.

How do I replace NA values with zeros in an R dataframe?

It is also possible to use tidyr::replace_na.

    library(tidyr)
    df <- df %>% mutate_all(funs(replace_na(.,0)))

How to make Unicode charset in cmd.exe by default?

Open an elevated Command Prompt (run cmd as administrator). query your registry for available TT fonts to the console by:

    REG query "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Console\TrueTypeFont"

You'll see an output like :

    0    REG_SZ    Lucida Console
    00    REG_SZ    Consolas
    936    REG_SZ    *???
    932    REG_SZ    *MS ????

Now we need to add a TT font that supports the characters you need like Courier New, we do this by adding zeros to the string name, so in this case the next one would be "000" :

    REG ADD "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Console\TrueTypeFont" /v 000 /t REG_SZ /d "Courier New"

Now we implement UTF-8 support:

    REG ADD HKCU\Console /v CodePage /t REG_DWORD /d 65001 /f

Set default font to "Courier New":

    REG ADD HKCU\Console /v FaceName /t REG_SZ /d "Courier New" /f

Set font size to 20 :

    REG ADD HKCU\Console /v FontSize /t REG_DWORD /d 20 /f

Enable quick edit if you like :

    REG ADD HKCU\Console /v QuickEdit /t REG_DWORD /d 1 /f

Align two divs horizontally side by side center to the page using bootstrap css

Alternate Bootstrap 4 solution (this way you can use divs which are smaller than col-6):

<div class="container">
  <div class="row justify-content-center">
    <div class="col-4">
      One of two columns
    </div>
    <div class="col-4">
      One of two columns
    </div>
  </div>
</div>

Adjust plot title (main) position

To summarize and explain visually how it works. Code construction is as follows:

par(mar = c(3,2,2,1))
barplot(...all parameters...)
title("Title text", adj = 0.5, line = 0)

explanation:

par(mar = c(low, left, top, right)) - margins of the graph area.

title("text" - title text
      adj  = from left (0) to right (1) with anything in between: 0.1, 0.2, etc...
      line = positive values move title text up, negative - down)

How to execute a Windows command on a remote PC?

psexec \\RemoteComputer cmd.exe

or use ssh or TeamViewer or RemoteDesktop!

Javascript string replace with regex to strip off illegal characters

What you need are character classes. In that, you've only to worry about the ], \ and - characters (and ^ if you're placing it straight after the beginning of the character class "[" ).

Syntax: [characters] where characters is a list with characters.

Example:

var cleanString = dirtyString.replace(/[|&;$%@"<>()+,]/g, "");

How to inject window into a service?

With the release of angular 2.0.0-rc.5 NgModule was introduced. The previous solution stopped working for me. This is what I did to fix it:

app.module.ts:

@NgModule({        
  providers: [
    { provide: 'Window',  useValue: window }
  ],
  declarations: [...],
  imports: [...]
})
export class AppModule {}

In some component:

import { Component, Inject } from '@angular/core';

@Component({...})
export class MyComponent {
    constructor (@Inject('Window') window: Window) {}
}

You could also use an OpaqueToken instead of the string 'Window'

Edit:

The AppModule is used to bootstrap your application in main.ts like this:

import { platformBrowserDynamic  } from '@angular/platform-browser-dynamic';
import { AppModule } from './app/app.module';

platformBrowserDynamic().bootstrapModule(AppModule)

For more information about NgModule read the Angular 2 documentation: https://angular.io/docs/ts/latest/guide/ngmodule.html

How do I do a Date comparison in Javascript?

You could try adding the following script code to implement this:

if(CompareDates(smallDate,largeDate,'-') == 0) {
    alert('Selected date must be current date or previous date!');
return false;
}

function CompareDates(smallDate,largeDate,separator) {
    var smallDateArr = Array();
    var largeDateArr = Array(); 
    smallDateArr = smallDate.split(separator);
    largeDateArr = largeDate.split(separator);  
    var smallDt = smallDateArr[0];
    var smallMt = smallDateArr[1];
    var smallYr = smallDateArr[2];  
    var largeDt = largeDateArr[0];
    var largeMt = largeDateArr[1];
    var largeYr = largeDateArr[2];

    if(smallYr>largeYr) 
        return 0;
else if(smallYr<=largeYr && smallMt>largeMt)
    return 0;
else if(smallYr<=largeYr && smallMt==largeMt && smallDt>largeDt)
    return 0;
else 
    return 1;
}

How to extract base URL from a string in JavaScript?

Well, URL API object avoids splitting and constructing the url's manually.

 let url = new URL('https://stackoverflow.com/questions/1420881');
 alert(url.origin);

When to use 'raise NotImplementedError'?

Consider if instead it was:

class RectangularRoom(object):
    def __init__(self, width, height):
        pass

    def cleanTileAtPosition(self, pos):
        pass

    def isTileCleaned(self, m, n):
        pass

and you subclass and forget to tell it how to isTileCleaned() or, perhaps more likely, typo it as isTileCLeaned(). Then in your code, you'll get a None when you call it.

Will you get the overridden function you wanted? Definitely not.
Is None valid output? Who knows.
Is that intended behavior? Almost certainly not.
Will you get an error? It depends.

raise NotImplmentedError forces you to implement it, as it will throw an exception when you try to run it until you do so. This removes a lot of silent errors. It's similar to why a bare except is almost never a good idea: because people make mistakes and this makes sure they aren't swept under the rug.

Note: Using an abstract base class, as other answers have mentioned, is better still, as then the errors are frontloaded and the program won't run until you implement them (with NotImplementedError, it will only throw an exception if actually called).

Android Fragments and animation

My modified support library supports using both View animations (i.e. <translate>, <rotate>) and Object Animators (i.e. <objectAnimator>) for Fragment Transitions. It is implemented with NineOldAndroids. Refer to my documentation on github for details.

Using multiple IF statements in a batch file

IF EXIST "somefile.txt" (
  IF EXIST "someotherfile.txt" (
    SET var="somefile.txt","someotherfile.txt"
  )
) ELSE (
  CALL :SUB
)
:SUB
ECHO Sorry... nothin' there.
GOTO:EOF

Is this feasible?

SETLOCAL ENABLEDELAYEDEXPANSION
IF EXIST "somefile.txt" (
  SET var="somefile.txt"
  IF EXIST "someotherfile.txt" (
    SET var=!var!,"someotherfile.txt"
  )
) ELSE (
  IF EXIST "someotherfile.txt" (
    SET var="someotherfile.txt"
  ) ELSE (
  GOTO:EOF
  )
)

How do I clone a github project to run locally?

To clone a repository and place it in a specified directory use "git clone [url] [directory]". For example

git clone https://github.com/ryanb/railscasts-episodes.git Rails

will create a directory named "Rails" and place it in the new directory. Click here for more information.

PostgreSQL: how to convert from Unix epoch to date?

On Postgres 10:

SELECT to_timestamp(CAST(epoch_ms as bigint)/1000)

Display a message in Visual Studio's output window when not debug mode?

This whole thread confused the h#$l out of me until I realized you have to be running the debugger to see ANY trace or debug output. I needed a debug output (outside of the debugger) because my WebApp runs fine when I debug it but not when the debugger isn't running (SqlDataSource is instantiated correctly when running through the debugger).

Just because debug output can be seen when you're running in release mode doesn't mean you'll see anything if you're not running the debugger. Careful reading of Writing to output window of Visual Studio? gave me DebugView as an alternative. Extremely useful!

Hopefully this helps anyone else confused by this.

Angular ng-repeat Error "Duplicates in a repeater are not allowed."

If you call a ng-repeat within a < ul> tag, you may be able to allow duplicates. See this link for reference. See Todo2.html

Generating a random & unique 8 character string using MySQL

DELIMITER $$

USE `temp` $$

DROP PROCEDURE IF EXISTS `GenerateUniqueValue`$$

CREATE PROCEDURE `GenerateUniqueValue`(IN tableName VARCHAR(255),IN columnName VARCHAR(255)) 
BEGIN
    DECLARE uniqueValue VARCHAR(8) DEFAULT "";
    WHILE LENGTH(uniqueValue) = 0 DO
        SELECT CONCAT(SUBSTRING('ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789', RAND()*34+1, 1),
                SUBSTRING('ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789', RAND()*34+1, 1),
                SUBSTRING('ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789', RAND()*34+1, 1),
                SUBSTRING('ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789', RAND()*34+1, 1),
                SUBSTRING('ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789', RAND()*34+1, 1),
                SUBSTRING('ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789', RAND()*34+1, 1),
                SUBSTRING('ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789', RAND()*34+1, 1),
                SUBSTRING('ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789', RAND()*34+1, 1)
                ) INTO @newUniqueValue;
        SET @rcount = -1;
        SET @query=CONCAT('SELECT COUNT(*) INTO @rcount FROM  ',tableName,' WHERE ',columnName,'  like ''',@newUniqueValue,'''');
        PREPARE stmt FROM  @query;
        EXECUTE stmt;
        DEALLOCATE PREPARE stmt;
    IF @rcount = 0 THEN
            SET uniqueValue = @newUniqueValue ;
        END IF ;
    END WHILE ;
    SELECT uniqueValue;
    END$$

DELIMITER ;

Use this stored procedure and use it everytime like

Call GenerateUniqueValue('tableName','columnName')

How do I to insert data into an SQL table using C# as well as implement an upload function?

using System;
using System.Data;
using System.Data.SqlClient;

namespace InsertingData
{
    class sqlinsertdata
    {
        static void Main(string[] args)
        {
            try
            { 
            SqlConnection conn = new SqlConnection("Data source=USER-PC; Database=Emp123;User Id=sa;Password=sa123");
            conn.Open();
                SqlCommand cmd = new SqlCommand("insert into <Table Name>values(1,'nagendra',10000);",conn);
                cmd.ExecuteNonQuery();
                Console.WriteLine("Inserting Data Successfully");
                conn.Close();
        }
            catch(Exception e)
            {
                Console.WriteLine("Exception Occre while creating table:" + e.Message + "\t"  + e.GetType());
            }
            Console.ReadKey();

    }
    }
}

MySQL/SQL: Group by date only on a Datetime column

Or:

SELECT SUM(foo), DATE(mydate) mydate FROM a_table GROUP BY mydate;

More efficient (I think.) Because you don't have to cast mydate twice per row.

slf4j: how to log formatted message, object array, exception

As of SLF4J 1.6.0, in the presence of multiple parameters and if the last argument in a logging statement is an exception, then SLF4J will presume that the user wants the last argument to be treated as an exception and not a simple parameter. See also the relevant FAQ entry.

So, writing (in SLF4J version 1.7.x and later)

 logger.error("one two three: {} {} {}", "a", "b", 
              "c", new Exception("something went wrong"));

or writing (in SLF4J version 1.6.x)

 logger.error("one two three: {} {} {}", new Object[] {"a", "b", 
              "c", new Exception("something went wrong")});

will yield

one two three: a b c
java.lang.Exception: something went wrong
    at Example.main(Example.java:13)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at ...

The exact output will depend on the underlying framework (e.g. logback, log4j, etc) as well on how the underlying framework is configured. However, if the last parameter is an exception it will be interpreted as such regardless of the underlying framework.

How to import a bak file into SQL Server Express

Using management studio the procedure can be done as follows

right click on the Databases container within object explorer
from context menu select Restore database
Specify To Database as either a new or existing database
Specify Source for restore as from device
Select Backup media as File
Click the Add button and browse to the location of the BAK file

refer

You'll need to specify the WITH REPLACE option to overwrite the existing adventure_second database with a backup taken from a different database.

Click option menu and tick Overwrite the existing database(With replace)

Reference

Angular 2 router.navigate

_x000D_

import { ActivatedRoute } from '@angular/router';_x000D_
_x000D_
export class ClassName {_x000D_
  _x000D_
  private router = ActivatedRoute;_x000D_
_x000D_
    constructor(r: ActivatedRoute) {_x000D_
        this.router =r;_x000D_
    }_x000D_
_x000D_
onSuccess() {_x000D_
     this.router.navigate(['/user_invitation'],_x000D_
         {queryParams: {email: loginEmail, code: userCode}});_x000D_
}_x000D_
_x000D_
}_x000D_
_x000D_
_x000D_
Get this values:_x000D_
---------------_x000D_
_x000D_
ngOnInit() {_x000D_
    this.route_x000D_
        .queryParams_x000D_
        .subscribe(params => {_x000D_
            let code = params['code'];_x000D_
            let userEmail = params['email'];_x000D_
        });_x000D_
}

_x000D_

Ref: https://angular.io/docs/ts/latest/api/router/index/NavigationExtras-interface.html

Psexec "run as (remote) admin"

Use psexec -s

The s switch will cause it to run under system account which is the same as running an elevated admin prompt. just used it to enable WinRM remotely.

Credit card expiration dates - Inclusive or exclusive?

lots of big companies dont even use your expiration date anymore because it causes auto-renewal of payments to be lost when cards are issued with new expiration dates and the same account number. This has been a huge problem in the service industry, so these companies have cornered the card issuers into processing payments w/o expiration dates to avoid this pitfall. Not many people know about this yet, so not all companies use this practice.

How to parse JSON without JSON.NET library?

You can use DataContractJsonSerializer. See this link for more details.

Why does only the first line of this Windows batch file execute but all three lines execute in a command shell?

It should be that the particular mvn command execs and does not return, thereby not executing the rest of the commands.

What does it mean to write to stdout in C?

That means that you are printing output on the main output device for the session... whatever that may be. The user's console, a tty session, a file or who knows what. What that device may be varies depending on how the program is being run and from where.

The following command will write to the standard output device (stdout)...

printf( "hello world\n" );

Which is just another way, in essence, of doing this...

fprintf( stdout, "hello world\n" );

In which case stdout is a pointer to a FILE stream that represents the default output device for the application. You could also use

fprintf( stderr, "that didn't go well\n" );

in which case you would be sending the output to the standard error output device for the application which may, or may not, be the same as stdout -- as with stdout, stderr is a pointer to a FILE stream representing the default output device for error messages.

Absolute and Flexbox in React Native

The first step would be to add

position: 'absolute',

then if you want the element full width, add

left: 0,
right: 0,

then, if you want to put the element in the bottom, add

bottom: 0,
// don't need set top: 0

if you want to position the element at the top, replace bottom: 0 by top: 0

pass array to method Java

In this way we can pass an array to a function, here this print function will print the contents of the array.

public class PassArrayToFunc {

    public static void print(char [] arr) {
        for(int i = 0 ; i<arr.length;i++) {
            System.out.println(arr[i]);
        }
    }

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        char [] array = scan.next().toCharArray();
        print(array);
        scan.close();
    }

}

How do I "select Android SDK" in Android Studio?

It helped me:

1. close project
2. remove .idea/ folder
3. select "import project (Gradle, Eclipse ADT, etc.)"

Environment:

Android Studio 3.1.3
OS Macos High Sierra 10.13.5

Another answers don't work for me.

Elasticsearch error: cluster_block_exception [FORBIDDEN/12/index read-only / allow delete (api)], flood stage disk watermark exceeded

This happens when Elasticsearch thinks the disk is running low on space so it puts itself into read-only mode.

By default Elasticsearch's decision is based on the percentage of disk space that's free, so on big disks this can happen even if you have many gigabytes of free space.

The flood stage watermark is 95% by default, so on a 1TB drive you need at least 50GB of free space or Elasticsearch will put itself into read-only mode.

For docs about the flood stage watermark see https://www.elastic.co/guide/en/elasticsearch/reference/6.2/disk-allocator.html.

The right solution depends on the context - for example a production environment vs a development environment.

Solution 1: free up disk space

Freeing up enough disk space so that more than 5% of the disk is free will solve this problem. Elasticsearch won't automatically take itself out of read-only mode once enough disk is free though, you'll have to do something like this to unlock the indices:

$ curl -XPUT -H "Content-Type: application/json" https://[YOUR_ELASTICSEARCH_ENDPOINT]:9200/_all/_settings -d '{"index.blocks.read_only_allow_delete": null}'

Solution 2: change the flood stage watermark setting

Change the "cluster.routing.allocation.disk.watermark.flood_stage" setting to something else. It can either be set to a lower percentage or to an absolute value. Here's an example of how to change the setting from the docs:

PUT _cluster/settings
{
  "transient": {
    "cluster.routing.allocation.disk.watermark.low": "100gb",
    "cluster.routing.allocation.disk.watermark.high": "50gb",
    "cluster.routing.allocation.disk.watermark.flood_stage": "10gb",
    "cluster.info.update.interval": "1m"
  }
}

Again, after doing this you'll have to use the curl command above to unlock the indices, but after that they should not go into read-only mode again.

How to set image width to be 100% and height to be auto in react native?

use aspectRatio property in style

Aspect ratio control the size of the undefined dimension of a node. Aspect ratio is a non-standard property only available in react native and not CSS.

On a node with a set width/height aspect ratio control the size of the unset dimension
On a node with a set flex basis aspect ratio controls the size of the node in the cross axis if unset
On a node with a measure function aspect ratio works as though the measure function measures the flex basis
On a node with flex grow/shrink aspect ratio controls the size of the node in the cross axis if unset
Aspect ratio takes min/max dimensions into account

docs: https://reactnative.dev/docs/layout-props#aspectratio

try like this:

import {Image, Dimensions} from 'react-native';

var width = Dimensions.get('window').width; 

<Image
    source={{
        uri: '<IMAGE_URI>'
    }}
    style={{
        width: width * .2,  //its same to '20%' of device width
        aspectRatio: 1, // <-- this
        resizeMode: 'contain', //optional
    }}
/>

How can I change a file's encoding with vim?

Just like your steps, setting fileencoding should work. However, I'd like to add one "set bomb" to help editor consider the file as UTF8.

$ vim file
:set bomb
:set fileencoding=utf-8
:wq

Loading/Downloading image from URL on Swift

A method for getting the image that is safe and works with Swift 2.0 and X-Code 7.1:

static func imageForImageURLString(imageURLString: String, completion: (image: UIImage?, success: Bool) -> Void) {
    guard let url = NSURL(string: imageURLString),
        let data = NSData(contentsOfURL: url),
        let image = UIImage(data: data)
        else { 
            completion(image: nil, success: false); 
            return 
       }

    completion(image: image, success: true)
}

You would then call this method like so:

imageForImageURLString(imageString) { (image, success) -> Void in
        if success {
            guard let image = image 
                 else { return } // Error handling here 
            // You now have the image. 
         } else {
            // Error handling here.
        }
    }

If you are updating the view with the image, you will have to use this after the "if success {":

    dispatch_async(dispatch_get_main_queue()) { () -> Void in
         guard let image = image 
              else { return } // Error handling here 
         // You now have the image. Use the image to update the view or anything UI related here
         // Reload the view, so the image appears
    }

The reason this last part is needed if you are using the image in the UI is because network calls take time. If you try to update the UI using the image without calling dispatch_async like above, the computer will look for the image while the image is still being fetched, find that there is no image (yet), and move on as if there was no image found. Putting your code inside of a dispatch_async completion closure says to the computer, "Go, get this image and when you are done, then complete this code." That way, you will have the image when the code is called and things will work well.

How to fix git error: RPC failed; curl 56 GnuTLS

I also encountered same and restart of the system resolved it :)

Most efficient way to remove special characters from string

I wonder if a Regex-based replacement (possibly compiled) is faster. ~~Would have to test that~~ Someone has found this to be ~5 times slower.

Other than that, you should initialize the StringBuilder with an expected length, so that the intermediate string doesn't have to be copied around while it grows.

A good number is the length of the original string, or something slightly lower (depending on the nature of the functions inputs).

Finally, you can use a lookup table (in the range 0..127) to find out whether a character is to be accepted.

Summarizing multiple columns with dplyr?

For completeness: with dplyr v0.2 ddply with colwise will also do this:

> ddply(df, .(grp), colwise(mean))
  grp        a    b        c        d
1   1 4.333333 4.00 1.000000 2.000000
2   2 2.000000 2.75 2.750000 2.750000
3   3 3.000000 4.00 4.333333 3.666667

but it is slower, at least in this case:

> microbenchmark(ddply(df, .(grp), colwise(mean)), 
                  df %>% group_by(grp) %>% summarise_each(funs(mean)))
Unit: milliseconds
                                            expr      min       lq     mean
                ddply(df, .(grp), colwise(mean))     3.278002 3.331744 3.533835
 df %>% group_by(grp) %>% summarise_each(funs(mean)) 1.001789 1.031528 1.109337

   median       uq      max neval
 3.353633 3.378089 7.592209   100
 1.121954 1.133428 2.292216   100

Reset git proxy to default configuration

If you have used Powershell commands to set the Proxy on windows machine doing the below helped me.

To unset the proxy use: 1. Open powershell 2. Enter the following:

[Environment]::SetEnvironmentVariable(“HTTP_PROXY”, $null, [EnvironmentVariableTarget]::Machine)
[Environment]::SetEnvironmentVariable(“HTTPS_PROXY”, $null, [EnvironmentVariableTarget]::Machine)

To set the proxy again use: 1. Open powershell 2. Enter the following:

[Environment]::SetEnvironmentVariable(“HTTP_PROXY”, “http://yourproxy.com:yourportnumber”, [EnvironmentVariableTarget]::Machine)
[Environment]::SetEnvironmentVariable(“HTTPS_PROXY”, “http://yourproxy.com:yourportnumber”, [EnvironmentVariableTarget]::Machine)

How to force addition instead of concatenation in javascript

Your code concatenates three strings, then converts the result to a number.

You need to convert each variable to a number by calling parseFloat() around each one.

total = parseFloat(myInt1) + parseFloat(myInt2) + parseFloat(myInt3);

How to determine if object is in array

Having been recently bitten by the FP bug reading many wonderful accounts of how neatly the functional paradigm fits with Javascript

I replicate the code for completeness sake and suggest two ways this can be done functionally.

    var carBrands = [];

  var car1 = {name:'ford'};
  var car2 = {name:'lexus'};
  var car3 = {name:'maserati'};
  var car4 = {name:'ford'};
  var car5 = {name:'toyota'};

  carBrands.push(car1);
  carBrands.push(car2);
  carBrands.push(car3);
  carBrands.push(car4);

  // ES6 approach which uses the includes method (Chrome47+, Firefox43+)

  carBrands.includes(car1) // -> true
  carBrands.includes(car5) // -> false

If you need to support older browsers use the polyfill, it seems IE9+ and Edge do NOT support it. Located in polyfill section of MSDN page

Alternatively I would like to propose an updated answer to cdhowie

// ES2015 syntax
function containsObject(obj, list) {

    return list.some(function(elem) {
      return elem === obj
    })
}

// or ES6+ syntax with cool fat arrows
function containsObject(obj, list) {

    return list.some(elem => elem === obj)
}

Proper way to empty a C-String

Two other ways are strcpy(str, ""); and string[0] = 0

To really delete the Variable contents (in case you have dirty code which is not working properly with the snippets above :P ) use a loop like in the example below.

#include <string.h>

...

int i=0;
for(i=0;i<strlen(string);i++)
{
    string[i] = 0;
}

In case you want to clear a dynamic allocated array of chars from the beginning, you may either use a combination of malloc() and memset() or - and this is way faster - calloc() which does the same thing as malloc but initializing the whole array with Null.

At last i want you to have your runtime in mind. All the way more, if you're handling huge arrays (6 digits and above) you should try to set the first value to Null instead of running memset() through the whole String.

It may look dirtier at first, but is way faster. You just need to pay more attention on your code ;)

I hope this was useful for anybody ;)

Visual Studio Code: How to show line endings

If you want to set it to LF as default, you can go to File->Preferences->Settings and under user settings you can paste this line in below your other user settings.

"files.eol": "\n"

For example.

"git.confirmSync": false,
"window.zoomLevel": -1,
"workbench.activityBar.visible": true,
"editor.wordWrap": true,
"workbench.iconTheme": "vscode-icons",
"window.menuBarVisibility": "default",
"vsicons.projectDetection.autoReload": true,
"files.eol": "\n"

Enable tcp\ip remote connections to sql server express already installed database with code or script(query)

I recommend to use SMO (Enable TCP/IP Network Protocol for SQL Server). However, it was not available in my case.

I rewrote the WMI commands from Krzysztof Kozielczyk to PowerShell.

# Enable TCP/IP

Get-CimInstance -Namespace root/Microsoft/SqlServer/ComputerManagement10 -ClassName ServerNetworkProtocol -Filter "InstanceName = 'SQLEXPRESS' and ProtocolName = 'Tcp'" |
Invoke-CimMethod -Name SetEnable

# Open the right ports in the firewall
New-NetFirewallRule -DisplayName 'MSSQL$SQLEXPRESS' -Direction Inbound -Action Allow -Protocol TCP -LocalPort 1433

# Modify TCP/IP properties to enable an IP address

$properties = Get-CimInstance -Namespace root/Microsoft/SqlServer/ComputerManagement10 -ClassName ServerNetworkProtocolProperty -Filter "InstanceName='SQLEXPRESS' and ProtocolName = 'Tcp' and IPAddressName='IPAll'"
$properties | ? { $_.PropertyName -eq 'TcpPort' } | Invoke-CimMethod -Name SetStringValue -Arguments @{ StrValue = '1433' }
$properties | ? { $_.PropertyName -eq 'TcpPortDynamic' } | Invoke-CimMethod -Name SetStringValue -Arguments @{ StrValue = '' }

# Restart SQL Server

Restart-Service 'MSSQL$SQLEXPRESS'

How to get first and last element in an array in java?

// Array of doubles
double[] array_doubles = {2.5, 6.2, 8.2, 4846.354, 9.6};

// First position
double firstNum = array_doubles[0]; // 2.5

// Last position
double lastNum = array_doubles[array_doubles.length - 1]; // 9.6

This is the same in any array.

Change Project Namespace in Visual Studio

Just right click on the name you want to change (this could be namespace or whatever else) and select Refactor->Rename...

Enter new name, leave location as [Global Namespace], check preview if you want and you're done!

How to fix Error: laravel.log could not be opened?

(on Ubuntu) : Can be solved in 2 simple steps :

$ sudo chmod -R 777 storage

And

$ sudo service apache2 restart

Yarn install command error No such file or directory: 'install'

The following steps worked on Pop!_OS 20.10 & ubuntu 20.04

sudo apt remove cmdtest
sudo apt remove yarn
curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
sudo apt-get update
sudo apt-get install yarn -y
yarn install

Python nonlocal statement

My personal understanding of the "nonlocal" statement (and do excuse me as I am new to Python and Programming in general) is that the "nonlocal" is a way to use the Global functionality within iterated functions rather than the body of the code itself. A Global statement between functions if you will.

How to change date format using jQuery?

var d = new Date();

var curr_date = d.getDate();

var curr_month = d.getMonth();

var curr_year = d.getFullYear();

curr_year = curr_year.toString().substr(2,2);

document.write(curr_date+"-"+curr_month+"-"+curr_year);

You can change this as your need..

How to print binary tree diagram?

I've created simple binary tree printer. You can use and modify it as you want, but it's not optimized anyway. I think that a lot of things can be improved here ;)

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class BTreePrinterTest {

    private static Node<Integer> test1() {
        Node<Integer> root = new Node<Integer>(2);
        Node<Integer> n11 = new Node<Integer>(7);
        Node<Integer> n12 = new Node<Integer>(5);
        Node<Integer> n21 = new Node<Integer>(2);
        Node<Integer> n22 = new Node<Integer>(6);
        Node<Integer> n23 = new Node<Integer>(3);
        Node<Integer> n24 = new Node<Integer>(6);
        Node<Integer> n31 = new Node<Integer>(5);
        Node<Integer> n32 = new Node<Integer>(8);
        Node<Integer> n33 = new Node<Integer>(4);
        Node<Integer> n34 = new Node<Integer>(5);
        Node<Integer> n35 = new Node<Integer>(8);
        Node<Integer> n36 = new Node<Integer>(4);
        Node<Integer> n37 = new Node<Integer>(5);
        Node<Integer> n38 = new Node<Integer>(8);

        root.left = n11;
        root.right = n12;

        n11.left = n21;
        n11.right = n22;
        n12.left = n23;
        n12.right = n24;

        n21.left = n31;
        n21.right = n32;
        n22.left = n33;
        n22.right = n34;
        n23.left = n35;
        n23.right = n36;
        n24.left = n37;
        n24.right = n38;

        return root;
    }

    private static Node<Integer> test2() {
        Node<Integer> root = new Node<Integer>(2);
        Node<Integer> n11 = new Node<Integer>(7);
        Node<Integer> n12 = new Node<Integer>(5);
        Node<Integer> n21 = new Node<Integer>(2);
        Node<Integer> n22 = new Node<Integer>(6);
        Node<Integer> n23 = new Node<Integer>(9);
        Node<Integer> n31 = new Node<Integer>(5);
        Node<Integer> n32 = new Node<Integer>(8);
        Node<Integer> n33 = new Node<Integer>(4);

        root.left = n11;
        root.right = n12;

        n11.left = n21;
        n11.right = n22;

        n12.right = n23;
        n22.left = n31;
        n22.right = n32;

        n23.left = n33;

        return root;
    }

    public static void main(String[] args) {

        BTreePrinter.printNode(test1());
        BTreePrinter.printNode(test2());

    }
}

class Node<T extends Comparable<?>> {
    Node<T> left, right;
    T data;

    public Node(T data) {
        this.data = data;
    }
}

class BTreePrinter {

    public static <T extends Comparable<?>> void printNode(Node<T> root) {
        int maxLevel = BTreePrinter.maxLevel(root);

        printNodeInternal(Collections.singletonList(root), 1, maxLevel);
    }

    private static <T extends Comparable<?>> void printNodeInternal(List<Node<T>> nodes, int level, int maxLevel) {
        if (nodes.isEmpty() || BTreePrinter.isAllElementsNull(nodes))
            return;

        int floor = maxLevel - level;
        int endgeLines = (int) Math.pow(2, (Math.max(floor - 1, 0)));
        int firstSpaces = (int) Math.pow(2, (floor)) - 1;
        int betweenSpaces = (int) Math.pow(2, (floor + 1)) - 1;

        BTreePrinter.printWhitespaces(firstSpaces);

        List<Node<T>> newNodes = new ArrayList<Node<T>>();
        for (Node<T> node : nodes) {
            if (node != null) {
                System.out.print(node.data);
                newNodes.add(node.left);
                newNodes.add(node.right);
            } else {
                newNodes.add(null);
                newNodes.add(null);
                System.out.print(" ");
            }

            BTreePrinter.printWhitespaces(betweenSpaces);
        }
        System.out.println("");

        for (int i = 1; i <= endgeLines; i++) {
            for (int j = 0; j < nodes.size(); j++) {
                BTreePrinter.printWhitespaces(firstSpaces - i);
                if (nodes.get(j) == null) {
                    BTreePrinter.printWhitespaces(endgeLines + endgeLines + i + 1);
                    continue;
                }

                if (nodes.get(j).left != null)
                    System.out.print("/");
                else
                    BTreePrinter.printWhitespaces(1);

                BTreePrinter.printWhitespaces(i + i - 1);

                if (nodes.get(j).right != null)
                    System.out.print("\\");
                else
                    BTreePrinter.printWhitespaces(1);

                BTreePrinter.printWhitespaces(endgeLines + endgeLines - i);
            }

            System.out.println("");
        }

        printNodeInternal(newNodes, level + 1, maxLevel);
    }

    private static void printWhitespaces(int count) {
        for (int i = 0; i < count; i++)
            System.out.print(" ");
    }

    private static <T extends Comparable<?>> int maxLevel(Node<T> node) {
        if (node == null)
            return 0;

        return Math.max(BTreePrinter.maxLevel(node.left), BTreePrinter.maxLevel(node.right)) + 1;
    }

    private static <T> boolean isAllElementsNull(List<T> list) {
        for (Object object : list) {
            if (object != null)
                return false;
        }

        return true;
    }

}

Output 1 :

         2               
        / \       
       /   \      
      /     \     
     /       \    
     7       5       
    / \     / \   
   /   \   /   \  
   2   6   3   6   
  / \ / \ / \ / \ 
  5 8 4 5 8 4 5 8

Output 2 :

       2               
      / \       
     /   \      
    /     \     
   /       \    
   7       5       
  / \       \   
 /   \       \  
 2   6       9   
    / \     /   
    5 8     4

mysql select from n last rows

Take advantage of SORT and LIMIT as you would with pagination. If you want the ith block of rows, use OFFSET.

SELECT val FROM big_table
where val = someval
ORDER BY id DESC
LIMIT n;

In response to Nir: The sort operation is not necessarily penalized, this depends on what the query planner does. Since this use case is crucial for pagination performance, there are some optimizations (see link above). This is true in postgres as well "ORDER BY ... LIMIT can be done without sorting " E.7.1. Last bullet

explain extended select id from items where val = 48 order by id desc limit 10;
+----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+
| id | select_type | table | type  | possible_keys | key     | key_len | ref   | rows | Extra       |
+----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+
|  1 | SIMPLE      | items | const | PRIMARY       | PRIMARY | 4       | const |    1 | Using index | 
+----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+

Remove last item from array

say you have var arr = [1,0,2]

arr.splice(-1,1) will return to you array [1,0]; while arr.slice(-1,1) will return to you array [2];

How to remove the default arrow icon from a dropdown list (select element)?

Just wanted to complete the thread. To be very clear this does not works in IE9, however we can do it by little css trick.

<div class="customselect">
    <select>
    <option>2000</option>
    <option>2001</option>
    <option>2002</option>
    </select>
</div>

.customselect {
    width: 80px;
    overflow: hidden;
   border:1px solid;
}

.customselect select {
   width: 100px;
   border:none;
  -moz-appearance: none;
   -webkit-appearance: none;
   appearance: none;
}

How to count TRUE values in a logical vector

Another option which hasn't been mentioned is to use which:

length(which(z))

Just to actually provide some context on the "which is faster question", it's always easiest just to test yourself. I made the vector much larger for comparison:

z <- sample(c(TRUE,FALSE),1000000,rep=TRUE)
system.time(sum(z))
   user  system elapsed 
   0.03    0.00    0.03
system.time(length(z[z==TRUE]))
   user  system elapsed 
   0.75    0.07    0.83 
system.time(length(which(z)))
   user  system elapsed 
   1.34    0.28    1.64 
system.time(table(z)["TRUE"])
   user  system elapsed 
  10.62    0.52   11.19

So clearly using sum is the best approach in this case. You may also want to check for NA values as Marek suggested.

Just to add a note regarding NA values and the which function:

> which(c(T, F, NA, NULL, T, F))
[1] 1 4
> which(!c(T, F, NA, NULL, T, F))
[1] 2 5

Note that which only checks for logical TRUE, so it essentially ignores non-logical values.

Writing string to a file on a new line every time

Unless write to binary files, use print. Below example good for formatting csv files:

def write_row(file_, *columns):
    print(*columns, sep='\t', end='\n', file=file_)

Usage:

PHI = 45
with open('file.csv', 'a+') as f:
    write_row(f, 'header', 'phi:', PHI, 'serie no. 2')
    write_row(f)  # newline
    write_row(f, data[0], data[1])

Notes:

print documentation
'{}, {}'.format(1, 'the_second') - https://pyformat.info/, PEP-3101
'\t' - tab character
*columns in function definition - dispatches any number of arguments to list - see question on *args & **kwargs

WPF global exception handler

I use the following code in my WPF apps to show a "Sorry for the inconvenience" dialog box whenever an unhandled exception occurs. It shows the exception message, and asks user whether they want to close the app or ignore the exception and continue (the latter case is convenient when a non-fatal exceptions occur and user can still normally continue to use the app).

In App.xaml add the Startup event handler:

<Application .... Startup="Application_Startup">

In App.xaml.cs code add Startup event handler function that will register the global application event handler:

using System.Windows.Threading;

private void Application_Startup(object sender, StartupEventArgs e)
{
    // Global exception handling  
    Application.Current.DispatcherUnhandledException += new DispatcherUnhandledExceptionEventHandler(AppDispatcherUnhandledException);    
}

void AppDispatcherUnhandledException(object sender, DispatcherUnhandledExceptionEventArgs e)
{    
    \#if DEBUG   // In debug mode do not custom-handle the exception, let Visual Studio handle it

    e.Handled = false;

    \#else

    ShowUnhandledException(e);    

    \#endif     
}

void ShowUnhandledException(DispatcherUnhandledExceptionEventArgs e)
{
    e.Handled = true;

    string errorMessage = string.Format("An application error occurred.\nPlease check whether your data is correct and repeat the action. If this error occurs again there seems to be a more serious malfunction in the application, and you better close it.\n\nError: {0}\n\nDo you want to continue?\n(if you click Yes you will continue with your work, if you click No the application will close)",

    e.Exception.Message + (e.Exception.InnerException != null ? "\n" + 
    e.Exception.InnerException.Message : null));

    if (MessageBox.Show(errorMessage, "Application Error", MessageBoxButton.YesNoCancel, MessageBoxImage.Error) == MessageBoxResult.No)   {
        if (MessageBox.Show("WARNING: The application will close. Any changes will not be saved!\nDo you really want to close it?", "Close the application!", MessageBoxButton.YesNoCancel, MessageBoxImage.Warning) == MessageBoxResult.Yes)
    {
        Application.Current.Shutdown();
    } 
}

Random Number Between 2 Double Numbers

Yes.

Random.NextDouble returns a double between 0 and 1. You then multiply that by the range you need to go into (difference between maximum and minimum) and then add that to the base (minimum).

public double GetRandomNumber(double minimum, double maximum)
{ 
    Random random = new Random();
    return random.NextDouble() * (maximum - minimum) + minimum;
}

Real code should have random be a static member. This will save the cost of creating the random number generator, and will enable you to call GetRandomNumber very frequently. Since we are initializing a new RNG with every call, if you call quick enough that the system time doesn't change between calls the RNG will get seeded with the exact same timestamp, and generate the same stream of random numbers.

How to delete last character from a string using jQuery?

@skajfes and @GolezTrol provided the best methods to use. Personally, I prefer using "slice()". It's less code, and you don't have to know how long a string is. Just use:

//-----------------------------------------
// @param begin  Required. The index where 
//               to begin the extraction. 
//               1st character is at index 0
//
// @param end    Optional. Where to end the
//               extraction. If omitted, 
//               slice() selects all 
//               characters from the begin 
//               position to the end of 
//               the string.
var str = '123-4';
alert(str.slice(0, -1));

Failed to load c++ bson extension

I just ran:

sudo npm install bson

and

sudo npm update

and all become ok.

SELECT with a Replace()

if you want any hope of ever using an index, store the data in a consistent manner (with the spaces removed). Either just remove the spaces or add a persisted computed column, Then you can just select from that column and not have to add all the space removing overhead every time you run your query.

add a PERSISTED computed column:

ALTER TABLE Contacts ADD PostcodeSpaceFree AS Replace(Postcode, ' ', '') PERSISTED 
go
CREATE NONCLUSTERED INDEX IX_Contacts_PostcodeSpaceFree 
ON Contacts (PostcodeSpaceFree) --INCLUDE (covered columns here!!)
go

to just fix the column by removing the spaces use:

UPDATE Contacts
    SET Postcode=Replace(Postcode, ' ', '')

now you can search like this, either select can use an index:

--search the PERSISTED computed column
SELECT 
    PostcodeSpaceFree 
    FROM Contacts
    WHERE PostcodeSpaceFree  LIKE 'NW101%'

--search the fixed (spaces removed column)
SELECT 
    Postcode
    FROM Contacts
    WHERE PostcodeLIKE 'NW101%'

What is the difference between for and foreach?

A for loop is useful when you have an indication or determination, in advance, of how many times you want a loop to run. As an example, if you need to perform a process for each day of the week, you know you want 7 loops.

A foreach loop is when you want to repeat a process for all pieces of a collection or array, but it is not important specifically how many times the loop runs. As an example, you are formatting a list of favorite books for users. Every user may have a different number of books, or none, and we don't really care how many it is, we just want the loop to act on all of them.

Remove leading or trailing spaces in an entire column of data

If you would like to use a formula, the TRIM function will do exactly what you're looking for:

+----+------------+---------------------+
|    |     A      |           B         |
+----+------------+---------------------+
| 1  | =TRIM(B1)  |  value to trim here |
+----+------------+---------------------+

So to do the whole column...
1) Insert a column
2) Insert TRIM function pointed at cell you are trying to correct.
3) Copy formula down the page
4) Copy inserted column
5) Paste as "Values"

Should be good to go from there...

How can I read numeric strings in Excel cells as string (not numbers)?

I also have had a similar issue on a data set of thousands of numbers and I think that I have found a simple way to solve. I needed to get the apostrophe inserted before a number so that a separate DB import always sees the numbers as text. Before this the number 8 would be imported as 8.0.

Solution:

Keep all the formatting as General.
Here I am assuming numbers are stored in Column A starting at Row 1.
Put in the ' in Column B and copy down as many rows as needed. Nothing appears in the worksheet but clicking on the cell you can see the apostophe in the Formula bar.
In Column C: =B1&A1.
Select all the Cells in Column C and do a Paste Special into Column D using the Values option.

Hey Presto all the numbers but stored as Text.

How can I get the current PowerShell executing file?

Did some testing with the following script, on both PS 2 and PS 4 and had the same result. I hope this helps people.

$PSVersionTable.PSVersion
function PSscript {
  $PSscript = Get-Item $MyInvocation.ScriptName
  Return $PSscript
}
""
$PSscript = PSscript
$PSscript.FullName
$PSscript.Name
$PSscript.BaseName
$PSscript.Extension
$PSscript.DirectoryName

""
$PSscript = Get-Item $MyInvocation.InvocationName
$PSscript.FullName
$PSscript.Name
$PSscript.BaseName
$PSscript.Extension
$PSscript.DirectoryName

Results -

Major  Minor  Build  Revision
-----  -----  -----  --------
4      0      -1     -1      

C:\PSscripts\Untitled1.ps1
Untitled1.ps1
Untitled1
.ps1
C:\PSscripts

C:\PSscripts\Untitled1.ps1
Untitled1.ps1
Untitled1
.ps1
C:\PSscripts

ASP.net using a form to insert data into an sql server table

Simple, make a simple asp page with the designer (just for the beginning) Lets say the body is something like this:

<body>
    <form id="form1" runat="server">
    <div>
        <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
        <br />
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
    </div>
    <p>
        <asp:Button ID="Button1" runat="server" Text="Button" />
    </p>
    </form>
</body>

Great, now every asp object IS an object. So you can access it in the asp's CS code. The asp's CS code is triggered by events (mostly). The class will probably inherit from System.Web.UI.Page

If you go to the cs file of the asp page, you'll see a protected void Page_Load(object sender, EventArgs e) ... That's the load event, you can use that to populate data into your objects when the page loads.

Now, go to the button in your designer (Button1) and look at its properties, you can design it, or add events from there. Just change to the events view, and create a method for the event.

The button is a web control Button Add a Click event to the button call it Button1Click:

void Button1Click(Object sender,EventArgs e) { }

Now when you click the button, this method will be called. Because ASP is object oriented, you can think of the page as the actual class, and the objects will hold the actual current data.

So if for example you want to access the text in TextBox1 you just need to call that object in the C# code:

String firstBox = TextBox1.Text;

In the same way you can populate the objects when event occur.

Now that you have the data the user posted in the textboxes , you can use regular C# SQL connections to add the data to your database.

How do I get current date/time on the Windows command line in a suitable format for usage in a file/folder name?

http://sourceforge.net/projects/unxutils/files/

Look inside the ZIP file for something called "Date.exe" and rename it "DateFormat.exe" (to avoid conflicts).

Put it in your Windows system32 folder.

It has a lot of "date output" options.

For help, use DateFormat.exe --h

I'm not sure how you would put its output into an environment variable... using SET.

Could not find folder 'tools' inside SDK

By default it looks for the SDK tools in "C:\Documents and Settings\user\android-sdks". Some times we install it at another location. So you just have to select the correct path and it will done.

Installation Issue with matplotlib Python

Problem Cause

In mac os image rendering back end of matplotlib (what-is-a-backend to render using the API of Cocoa by default). There are Qt4Agg and GTKAgg and as a back-end is not the default. Set the back end of macosx that is differ compare with other windows or linux os.

Solution

I assume you have installed the pip matplotlib, there is a directory in your root called ~/.matplotlib.
Create a file ~/.matplotlib/matplotlibrc there and add the following code: backend: TkAgg

From this link you can try different diagrams.

Remove spacing between table cells and rows

I had a similar problem and I solved it by (inline)styling the td element as follows :

<td style="display: block;">

This will work although its not the best practice. In my case I was working on a old template that had been styled using HTML tables.

In C, how should I read a text file and print all strings

Use "read()" instead o fscanf:

ssize_t read(int fildes, void *buf, size_t nbyte);

DESCRIPTION

The read() function shall attempt to read nbyte bytes from the file associated with the open file descriptor, fildes, into the buffer pointed to by buf.

Here is an example:

http://cmagical.blogspot.com/2010/01/c-programming-on-unix-implementing-cat.html

Working part from that example:

f=open(argv[1],O_RDONLY);
while ((n=read(f,l,80)) > 0)
    write(1,l,n);

An alternate approach is to use getc/putc to read/write 1 char at a time. A lot less efficient. A good example: http://www.eskimo.com/~scs/cclass/notes/sx13.html

What is wrong with this code that uses the mysql extension to fetch data from a database in PHP?

Code:

while ($rows = mysql_fetch_array($query)):
       $name = $rows['Name'];
       $address = $rows['Address'];
       $email = $rows['Email'];
       $subject = $rows['Subject'];
       $comment = $rows['Comment']
       echo "$name<br>$address<br>$email<br>$subject<br>$comment<br><br>";
endwhile;

SQL Stored Procedure set variables using SELECT

One advantage your current approach does have is that it will raise an error if multiple rows are returned by the predicate. To reproduce that you can use.

SELECT @currentTerm = currentterm,
       @termID = termid,
       @endDate = enddate
FROM   table1
WHERE  iscurrent = 1

IF( @@ROWCOUNT <> 1 )
  BEGIN
      RAISERROR ('Unexpected number of matching rows',
                 16,
                 1)

      RETURN
  END

Unable to load DLL (Module could not be found HRESULT: 0x8007007E)

I faced the same problem when import C++ Dll in .Net Framework +4, I unchecked Project->Properties->Build->Prefer 32-bit and it solved for me.

Commenting out a set of lines in a shell script

Depending of the editor that you're using there are some shortcuts to comment a block of lines.

Another workaround would be to put your code in an "if (0)" conditional block ;)

Send email using java

Here is the working solution bro. It's guranteed.

First of all open your gmail account from which you wanted to send mail, like in you case [email protected]
Open this link below:

https://support.google.com/accounts/answer/6010255?hl=en
Click on "Go to the "Less secure apps" section in My Account." option
Then turn on it
That's it (:

Here is my code:

import javax.mail.*;
import javax.mail.internet.*;
import java.util.*;

public class SendEmail {

   final String senderEmailID = "Sender Email id";
final String senderPassword = "Sender Pass word";
final String emailSMTPserver = "smtp.gmail.com";
final String emailServerPort = "465";
String receiverEmailID = null;
static String emailSubject = "Test Mail";
static String emailBody = ":)";
public SendEmail(String receiverEmailID, String emailSubject, String emailBody)
{
this.receiverEmailID=receiverEmailID;
this.emailSubject=emailSubject;
this.emailBody=emailBody;
Properties props = new Properties();
props.put("mail.smtp.user",senderEmailID);
props.put("mail.smtp.host", emailSMTPserver);
props.put("mail.smtp.port", emailServerPort);
props.put("mail.smtp.starttls.enable", "true");
props.put("mail.smtp.auth", "true");
props.put("mail.smtp.socketFactory.port", emailServerPort);
props.put("mail.smtp.socketFactory.class","javax.net.ssl.SSLSocketFactory");
props.put("mail.smtp.socketFactory.fallback", "false");
SecurityManager security = System.getSecurityManager();
try
{
Authenticator auth = new SMTPAuthenticator();
Session session = Session.getInstance(props, auth);
MimeMessage msg = new MimeMessage(session);
msg.setText(emailBody);
msg.setSubject(emailSubject);
msg.setFrom(new InternetAddress(senderEmailID));
msg.addRecipient(Message.RecipientType.TO,
new InternetAddress(receiverEmailID));
Transport.send(msg);
System.out.println("Message send Successfully:)");
}
catch (Exception mex)
{
mex.printStackTrace();
}
}
public class SMTPAuthenticator extends javax.mail.Authenticator
{
public PasswordAuthentication getPasswordAuthentication()
{
return new PasswordAuthentication(senderEmailID, senderPassword);
}
}
    public static void main(String[] args) {
       SendEmail mailSender;
        mailSender = new SendEmail("Receiver Email id","Testing Code 2 example","Testing Code Body yess");
    }

}

scipy.misc module has no attribute imread?

The solution that work for me in python 3.6 is the following

py -m pip install Pillow

How do I specify the platform for MSBuild?

Hopefully this helps someone out there.

For platform I was specifying "Any CPU", changed it to "AnyCPU" and that fixed the problem.

msbuild C:\Users\Project\Project.publishproj /p:Platform="AnyCPU"  /p:DeployOnBuild=true /p:PublishProfile=local /p:Configuration=Debug

If you look at your .csproj file you'll see the correct platform name to use.

Python, HTTPS GET with basic authentication

using only standard modules and no manual header encoding

...which seems to be the intended and most portable way

the concept of python urllib is to group the numerous attributes of the request into various managers/directors/contexts... which then process their parts:

import urllib.request, ssl

# to avoid verifying ssl certificates
httpsHa = urllib.request.HTTPSHandler(context= ssl._create_unverified_context())

# setting up realm+urls+user-password auth
# (top_level_url may be sequence, also the complete url, realm None is default)
top_level_url = 'https://ip:port_or_domain'
# of the std managers, this can send user+passwd in one go,
# not after HTTP req->401 sequence
password_mgr = urllib.request.HTTPPasswordMgrWithPriorAuth()
password_mgr.add_password(None, top_level_url, "user", "password", is_authenticated=True)

handler = urllib.request.HTTPBasicAuthHandler(password_mgr)
# create OpenerDirector
opener = urllib.request.build_opener(handler, httpsHa)

url = top_level_url + '/some_url?some_query...'
response = opener.open(url)

print(response.read())

How to position a table at the center of div horizontally & vertically

To position horizontally center you can say width: 50%; margin: auto;. As far as I know, that's cross browser. For vertical alignment you can try vertical-align:middle;, but it may only work in relation to text. It's worth a try though.

PHP Notice: Undefined offset: 1 with array when reading data

Hide php warnings in file

error_reporting(0);

Is it possible to insert multiple rows at a time in an SQLite database?

in mysql lite you cannot insert multiple values, but you can save time by opening connection only one time and then doing all insertions and then closing connection. It saves a lot of time

Converting a number with comma as decimal point to float

from PHP manual:

str_replace — Replace all occurrences of the search string with the replacement string

I would go down that route, and then convert from string to float - floatval

"You have mail" message in terminal, os X

Probably it is some message from your system.

Type in terminal:

man mail

, and see how can you get this message from your system.

How can you print a variable name in python?

If you are trying to do this, it means you are doing something wrong. Consider using a dict instead.

def show_val(vals, name):
    print "Name:", name, "val:", vals[name]

vals = {'a': 1, 'b': 2}
show_val(vals, 'b')

Output:

Name: b val: 2

What's the difference between MyISAM and InnoDB?

The main differences between InnoDB and MyISAM ("with respect to designing a table or database" you asked about) are support for "referential integrity" and "transactions".

If you need the database to enforce foreign key constraints, or you need the database to support transactions (i.e. changes made by two or more DML operations handled as single unit of work, with all of the changes either applied, or all the changes reverted) then you would choose the InnoDB engine, since these features are absent from the MyISAM engine.

Those are the two biggest differences. Another big difference is concurrency. With MyISAM, a DML statement will obtain an exclusive lock on the table, and while that lock is held, no other session can perform a SELECT or a DML operation on the table.

Those two specific engines you asked about (InnoDB and MyISAM) have different design goals. MySQL also has other storage engines, with their own design goals.

So, in choosing between InnoDB and MyISAM, the first step is in determining if you need the features provided by InnoDB. If not, then MyISAM is up for consideration.

A more detailed discussion of differences is rather impractical (in this forum) absent a more detailed discussion of the problem space... how the application will use the database, how many tables, size of the tables, the transaction load, volumes of select, insert, updates, concurrency requirements, replication features, etc.

The logical design of the database should be centered around data analysis and user requirements; the choice to use a relational database would come later, and even later would the choice of MySQL as a relational database management system, and then the selection of a storage engine for each table.

Syntax error on print with Python 3

Because in Python 3, print statement has been replaced with a print() function, with keyword arguments to replace most of the special syntax of the old print statement. So you have to write it as

print("Hello World")

But if you write this in a program and someone using Python 2.x tries to run it, they will get an error. To avoid this, it is a good practice to import print function:

from __future__ import print_function

Now your code works on both 2.x & 3.x.

Check out below examples also to get familiar with print() function.

Old: print "The answer is", 2*2
New: print("The answer is", 2*2)

Old: print x,           # Trailing comma suppresses newline
New: print(x, end=" ")  # Appends a space instead of a newline

Old: print              # Prints a newline
New: print()            # You must call the function!

Old: print >>sys.stderr, "fatal error"
New: print("fatal error", file=sys.stderr)

Old: print (x, y)       # prints repr((x, y))
New: print((x, y))      # Not the same as print(x, y)!

Source: What’s New In Python 3.0?

Get month name from Date

Instead of declaring array which hold all the month name and then pointing with an index, we can also write it in a shorter version as below:

var objDate = new Date().toLocaleString("en-us", { month: "long" }); // result: August
var objDate = new Date().toLocaleString("en-us", { month: "short" }); // result: Aug

How to query between two dates using Laravel and Eloquent?

If you want to check if current date exist in between two dates in db: =>here the query will get the application list if employe's application from and to date is exist in todays date.

$list=  (new LeaveApplication())
            ->whereDate('from','<=', $today)
            ->whereDate('to','>=', $today)
            ->get();

CSS Background Image Not Displaying

if you are using vs code just try using background:url("img/bimg.jpg") instead of background:url('img/bimg.jpg') Mine worked at it Nothing much I replaced ' with "

Node.js - use of module.exports as a constructor

At the end, Node is about Javascript. JS has several way to accomplished something, is the same thing to get an "constructor", the important thing is to return a function.

This way actually you are creating a new function, as we created using JS on Web Browser environment for example.

Personally i prefer the prototype approach, as Sukima suggested on this post: Node.js - use of module.exports as a constructor

How to copy Java Collections list

b has a capacity of 3, but a size of 0. The fact that ArrayList has some sort of buffer capacity is an implementation detail - it's not part of the List interface, so Collections.copy(List, List) doesn't use it. It would be ugly for it to special-case ArrayList.

As MrWiggles has indicated, using the ArrayList constructor which takes a collection is the way to in the example provided.

For more complicated scenarios (which may well include your real code), you may find the collections within Guava useful.

How to open an existing project in Eclipse?

From the main menu bar, select command link File > Import.... The Import wizard opens.
Select General > Existing Project into Workspace and click Next.
Choose either Select root directory or Select archive file and click the associated Browse to locate the directory or file containing the projects.
Under Projects select the project or projects which you would like to import.
Click Finish to start the import.

Running conda with proxy

One mistake I was making was saving the file as a.condarc or b.condarc.

Save it only as .condarc and paste the following code in the file and save the file in your home directory. Make necessary changes to hostname, user etc.

channels:
- defaults

show_channel_urls: True
allow_other_channels: True

proxy_servers:
    http: http://user:pass@hostname:port
    https: http://user:pass@hostname:port


ssl_verify: False

Eclipse error ... cannot be resolved to a type

Download servlet-api.jar file and paste it in WEB-INF folder it will work

How to reload the current state?

Probably the cleaner approach would be the following :

<a data-ui-sref="directory.organisations.details" data-ui-sref-opts="{reload: true}">Details State</a>

We can reload the state from the HTML only.

Find all tables containing column with specified name - MS SQL Server

Hopefully this isn't a duplicate answer, but what I like to do is generate a sql statement within a sql statement that will allow me to search for the values I am looking for (not just the tables with those field names ( as it's usually necessary for me to then delete any info related to the id of the column name I am looking for):

  SELECT  'Select * from ' + t.name + ' where ' + c.name + ' = 148' AS SQLToRun
  FROM sys.columns c, c.name as ColName, t.name as TableName
  JOIN sys.tables t 
     ON c.object_id = t.object_id
  WHERE c.name LIKE '%ProjectID%'

Then I can copy and paste run my 1st column "SQLToRun"... then I replace the "Select * from ' with 'Delete from ' and it allows me to delete any references to that given ID! Write these results to file so you have them just in case.

NOTE**** Make sure you eliminate any bakup tables prior to running your your delete statement...

  SELECT  'Delete from ' + t.name + ' where ' + c.name + ' = 148' AS SQLToRun
  FROM sys.columns c, c.name as ColName, t.name as TableName
  JOIN sys.tables t 
     ON c.object_id = t.object_id
  WHERE c.name LIKE '%ProjectID%'

Convert generic list to dataset in C#

I found this code on Microsoft forum. This is so far one of easiest way, easy to understand and use. This has saved me hours , I have customized it as extension method without any change to actual method. Below is the code. it doesn't require much explanation.

You can use two function signature with same implementation

1) public static DataSet ToDataSetFromObject(this object dsCollection)

2) public static DataSet ToDataSetFromArrayOfObject( this object[] arrCollection) . I 'll be using this one for example.

// <summary>
// Serialize Object to XML and then read it into a DataSet:
// </summary>
// <param name="arrCollection">Array of object</param>
// <returns>dataset</returns>

public static DataSet ToDataSetFromArrayOfObject( this object[] arrCollection)
{
    DataSet ds = new DataSet();
    try {
        XmlSerializer serializer = new XmlSerializer(arrCollection.GetType);
        System.IO.StringWriter sw = new System.IO.StringWriter();
        serializer.Serialize(sw, dsCollection);
        System.IO.StringReader reader = new System.IO.StringReader(sw.ToString());
        ds.ReadXml(reader);
    } catch (Exception ex) {
        throw (new Exception("Error While Converting Array of Object to Dataset."));
    }
    return ds;
}

To use this extension in code

Country[] objArrayCountry = null;
objArrayCountry = ....;// populate your array
if ((objArrayCountry != null)) {
    dataset = objArrayCountry.ToDataSetFromArrayOfObject();
}

ionic build Android | error: No installed build tools found. Please install the Android build tools

In my case the problem was that ANDROID_HOME was pointing to ~/Library/Android/ for some reason. The correct path is ~/Library/Android/sdk

How do I configure Notepad++ to use spaces instead of tabs?

Go to the Preferences menu command under menu Settings, and select Language Menu/Tab Settings, depending on your version. Earlier versions use Tab Settings. Later versions use Language. Click the Replace with space check box. Set the size to 4.

See documentation: http://docs.notepad-plus-plus.org/index.php/Built-in_Languages#Tab_settings

How to convert a String into an ArrayList?

 String s1="[a,b,c,d]";
 String replace = s1.replace("[","");
 System.out.println(replace);
 String replace1 = replace.replace("]","");
 System.out.println(replace1);
 List<String> myList = new ArrayList<String>(Arrays.asList(replace1.split(",")));
 System.out.println(myList.toString());

How to remove hashbang from url?

For Vuejs 2.5 & vue-router 3.0 nothing above worked for me, however after playing around a little bit the following seems to work:

export default new Router({
  mode: 'history',
  hash: false,
  routes: [
  ...
    ,
    { path: '*', redirect: '/' }, // catch all use case
  ],
})

note that you will also need to add the catch-all path.

How to get multiple select box values using jQuery?

Html Code:

 <select id="multiple" multiple="multiple" name="multiple">
  <option value=""> -- Select -- </option>
  <option value="1">Opt1</option>
  <option value="2">Opt2</option>
  <option value="3">Opt3</option>
  <option value="4">Opt4</option>
  <option value="5">Opt5</option>
 </select>

JQuery Code:

$('#multiple :selected').each(function(i, sel){ 
    alert( $(sel).val() ); 

});

Hope it works

Getting list of Facebook friends with latest API

Use FQL instead, its a like SQL but for Facebook's data tables and easily covers data query you'de like to make. You won't have to use all of those /xx/xxx/xx calls, just know the tables and columns you are intereseted in.

$myQuery = "SELECT uid2 FROM friend WHERE uid1=me()";
$facebook->api( "/fql?q=" . urlencode($myQuery) )

Great interactive examples at http://developers.facebook.com/docs/reference/fql/

Write / add data in JSON file using Node.js

you should read the file, every time you want to add a new property to the json, and then add the the new properties

var fs = require('fs');
fs.readFile('data.json',function(err,content){
  if(err) throw err;
  var parseJson = JSON.parse(content);
  for (i=0; i <11 ; i++){
   parseJson.table.push({id:i, square:i*i})
  }
  fs.writeFile('data.json',JSON.stringify(parseJson),function(err){
    if(err) throw err;
  })
})

How to add header row to a pandas DataFrame

You can use names directly in the read_csv

names : array-like, default None List of column names to use. If file contains no header row, then you should explicitly pass header=None

Cov = pd.read_csv("path/to/file.txt", 
                  sep='\t', 
                  names=["Sequence", "Start", "End", "Coverage"])

Echo a blank (empty) line to the console from a Windows batch file

^{Note: Though my original answer attracted several upvotes, I decided that I could do much better. You can find my original (simplistic and misguided) answer in the edit history.}

If Microsoft had the intent of providing a means of outputting a blank line from cmd.exe, Microsoft surely would have documented such a simple operation. It is this omission that motivated me to ask this question.

So, because a means for outputting a blank line from cmd.exe is not documented, arguably one should consider any suggestion for how to accomplish this to be a hack. That means that there is no known method for outputting a blank line from cmd.exe that is guaranteed to work (or work efficiently) in all situations.

With that in mind, here is a discussion of methods that have been recommended for outputting a blank line from cmd.exe. All recommendations are based on variations of the echo command.

echo.

While this will work in many if not most situations, it should be avoided because it is slower than its alternatives and actually can fail (see here, here, and here). Specifically, cmd.exe first searches for a file named echo and tries to start it. If a file named echo happens to exist in the current working directory, echo. will fail with:

'echo.' is not recognized as an internal or external command,
operable program or batch file.

echo:
echo\

At the end of this answer, the author argues that these commands can be slow, for instance if they are executed from a network drive location. A specific reason for the potential slowness is not given. But one can infer that it may have something to do with accessing the file system. (Perhaps because : and \ have special meaning in a Windows file system path?)

However, some may consider these to be safe options since : and \ cannot appear in a file name. For that or another reason, echo: is recommended by SS64.com here.

echo(
echo+
echo,
echo/
echo;
echo=
echo[
echo]

This lengthy discussion includes what I believe to be all of these. Several of these options are recommended in this SO answer as well. Within the cited discussion, this post ends with what appears to be a recommendation for echo( and echo:.

My question at the top of this page does not specify a version of Windows. My experimentation on Windows 10 indicates that all of these produce a blank line, regardless of whether files named echo, echo+, echo,, ..., echo] exist in the current working directory. (Note that my question predates the release of Windows 10. So I concede the possibility that older versions of Windows may behave differently.)

In this answer, @jeb asserts that echo( always works. To me, @jeb's answer implies that other options are less reliable but does not provide any detail as to why that might be. Note that @jeb contributed much valuable content to other references I have cited in this answer.

Conclusion: Do not use echo.. Of the many other options I encountered in the sources I have cited, the support for these two appears most authoritative:

echo(
echo:

But I have not found any strong evidence that the use of either of these will always be trouble-free.

Example Usage:

@echo off
echo Here is the first line.
echo(
echo There is a blank line above this line.

Expected output:

Here is the first line.

There is a blank line above this line.

Data truncated for column?

I had the same problem, with a database field with type "SET" which is an enum type.

I tried to add a value which was not in that list.

The value I tried to add had the decimal value 256, but the enum list only had 8 values.

1: 1   -> A
2: 2   -> B
3: 4   -> C
4: 8   -> D
5: 16  -> E
6: 32  -> F
7: 64  -> G
8: 128 -> H

So I just had to add the additional value to the field.

Reading this documentation entry helped me to understand the problem.

MySQL stores SET values numerically, with the low-order bit of the stored value corresponding to the first set member. If you retrieve a SET value in a numeric context, the value retrieved has bits set corresponding to the set members that make up the column value. For example, you can retrieve numeric values from a SET column like this:
mysql> SELECT set_col+0 FROM tbl_name; If a number is stored into a
If a number is stored into a SET column, the bits that are set in the binary representation of the number determine the set members in the column value. For a column specified as SET('a','b','c','d'), the members have the following decimal and binary values.

SET Member  Decimal Value   Binary Value
    'a'                1          0001
    'b'                2          0010
    'c'                4          0100
    'd'                8          1000

If you assign a value of 9 to this column, that is 1001 in binary, so the first and fourth SET value members 'a' and 'd' are selected and the resulting value is 'a,d'.

change image opacity using javascript

You could use jQuery's animate or fadeTo.

How can I get column names from a table in SQL Server?

It will check whether the given the table is Base Table.

SELECT 
    T.TABLE_NAME AS 'TABLE NAME',
    C.COLUMN_NAME AS 'COLUMN NAME'
FROM INFORMATION_SCHEMA.TABLES T
INNER JOIN INFORMATION_SCHEMA.COLUMNS C ON T.TABLE_NAME=C.TABLE_NAME
    WHERE   T.TABLE_TYPE='BASE TABLE'
            AND T.TABLE_NAME LIKE 'Your Table Name'

List all the files and folders in a Directory with PHP recursive function

It's shorter version :

function getDirContents($path) {
    $rii = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($path));

    $files = array(); 
    foreach ($rii as $file)
        if (!$file->isDir())
            $files[] = $file->getPathname();

    return $files;
}

var_dump(getDirContents($path));

How to draw text using only OpenGL methods?

This article describes how to render text in OpenGL using various techniques.

With only using opengl, there are several ways:

using glBitmap
using textures
using display lists

How do you run JavaScript script through the Terminal?

Another answer would be the NodeJS!

Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.

Using terminal you will be able to start it using node command.

$ node
> 2 + 4
6
>

Note: If you want to exit just type

.exit

You can also run a JavaScript file like this:

node file.js

« Install it NOW »

Programs & Examples On #Gesture

Draw on HTML5 Canvas using a mouse

Extract first item of each sublist

How can I increase a scrollbar's width using CSS?

MD5 is 128 bits but why is it 32 characters?

A hex "character" (nibble) is different from a "character"

How many threads is too many?

How do I handle newlines in JSON?

How to format html table with inline styles to look like a rendered Excel table?

How to count the number of lines of a string in javascript

Html- how to disable <a href>?

Get size of all tables in database

How to delete the contents of a folder?

Get filename and path from URI from mediastore

How to add an item to an ArrayList in Kotlin?

initialize a vector to zeros C++/C++11

Querying Datatable with where condition

How do I install Eclipse Marketplace in Eclipse Classic?

Clear History and Reload Page on Login/Logout Using Ionic Framework

Align DIV to bottom of the page

'ng' is not recognized as an internal or external command, operable program or batch file

Stop all active ajax requests in jQuery

Npm Error - No matching version found for

"git rm --cached x" vs "git reset head --? x"?

Difference between <input type='submit' /> and <button type='submit'>text</button>

Submit button with <button>

Button with <input>

Normal submit button with <input>

Image submit button with <input>

iOS for VirtualBox

"The import org.springframework cannot be resolved."

How do I execute a PowerShell script automatically using Windows task scheduler?

Change window location Jquery

How to convert View Model into JSON object in ASP.NET MVC?

Swift GET request with parameters

Format numbers in JavaScript similar to C#

How to read/process command line arguments?

Bash: Syntax error: redirection unexpected

Trying to add adb to PATH variable OSX

Connection timeout for SQL server

How do you validate a URL with a regular expression in Python?

Combining two sorted lists in Python

How to insert an object in an ArrayList at a specific position

Android Studio Stuck at Gradle Download on create new project

Simple DateTime sql query

What is the most compatible way to install python modules on a Mac?

What do 1.#INF00, -1.#IND00 and -1.#IND mean?

BeautifulSoup: extract text from anchor tag

What is the Angular equivalent to an AngularJS $watch?

How to handle change of checkbox using jQuery?

Get text of label with jquery

Is <div style="width: ;height: ;background: "> CSS?

Encoding Error in Panda read_csv

Vertically align text within input field of fixed-height without display: table or padding?

How to assign string to bytes array

How to execute .sql script file using JDBC

Pyspark: display a spark data frame in a table format

How get value from URL

Adding and removing extensionattribute to AD object

ORA-00932: inconsistent datatypes: expected - got CLOB

Why is visible="false" not working for a plain html table?

What are all the uses of an underscore in Scala?

How to round up value C# to the nearest integer?

Computing cross-correlation function?

Why would $_FILES be empty when uploading files to PHP?

Erasing elements from a vector

How to map and remove nil values in Ruby

Method call if not null in C#

Sublime Text 2 - View whitespace characters

Of Countries and their Cities

Get all parameters from JSP page

Correctly determine if date string is a valid date in that format

Default values and initialization in Java

How to export query result to csv in Oracle SQL Developer?

How to create a .NET DateTime from ISO 8601 format

Adding value to input field with jQuery

Check if a string is a palindrome

How to launch an EXE from Web page (asp.net)

Extract filename and extension in Bash

Javascript to sort contents of select element

Submit button with `<button>`

Button with `<input>`

Normal submit button with `<input>`

Image submit button with `<input>`