Programs & Examples On #Mcisendstring

How to copy data from one table to another new table in MySQL?

CREATE TABLE newTable LIKE oldTable;

Then, to copy the data over

INSERT INTO newTable SELECT * FROM oldTable;

How can I run Android emulator for Intel x86 Atom without hardware acceleration on Windows 8 for API 21 and 19?

I have a pc with intel c2d without hardware accelaration i am having same problem in android studio. firstly i get bored with android studio and installed eclipse+sdk+adt then i have installed every thing and started emulator it worked then the same emulator worked in android studio for direct launching application in android studio and i have also runned the sample app that emulator so you can run android studio without virtualization technique even your processor does not sopport vt-x

Root element is missing

Hi this is odd way but try it once

  1. Read the file content into a string
  2. print the string and check whether you are getting proper XML or not
  3. you can use XMLDocument.LoadXML(xmlstring)

I try with your code and same XML without adding any XML declaration it works for me

XmlDocument doc = new XmlDocument();
        doc.Load(@"H:\WorkSpace\C#\TestDemos\TestDemos\XMLFile1.xml");
        XmlNodeList nodes = doc.GetElementsByTagName("Product");
        XmlNode node = null;
        foreach (XmlNode n in nodes)
        {
            Console.WriteLine("HI");
        }

Its working perfectly fine

Java, Shifting Elements in an Array

Just for completeness: Stream solution since Java 8.

final String[] shiftedArray = Arrays.stream(array)
        .skip(1)
        .toArray(String[]::new);

I think I sticked with the System.arraycopy() in your situtation. But the best long-term solution might be to convert everything to Immutable Collections (Guava, Vavr), as long as those collections are short-lived.

Multiple conditions in if statement shell script

You are trying to compare strings inside an arithmetic command (((...))). Use [[ instead.

if [[ $username == "$username1" && $password == "$password1" ]] ||
   [[ $username == "$username2" && $password == "$password2" ]]; then

Note that I've reduced this to two separate tests joined by ||, with the && moved inside the tests. This is because the shell operators && and || have equal precedence and are simply evaluated from left to right. As a result, it's not generally true that a && b || c && d is equivalent to the intended ( a && b ) || ( c && d ).

All possible array initialization syntaxes

Non-empty arrays

  • var data0 = new int[3]

  • var data1 = new int[3] { 1, 2, 3 }

  • var data2 = new int[] { 1, 2, 3 }

  • var data3 = new[] { 1, 2, 3 }

  • var data4 = { 1, 2, 3 } is not compilable. Use int[] data5 = { 1, 2, 3 } instead.

Empty arrays

  • var data6 = new int[0]
  • var data7 = new int[] { }
  • var data8 = new [] { } and int[] data9 = new [] { } are not compilable.

  • var data10 = { } is not compilable. Use int[] data11 = { } instead.

As an argument of a method

Only expressions that can be assigned with the var keyword can be passed as arguments.

  • Foo(new int[2])
  • Foo(new int[2] { 1, 2 })
  • Foo(new int[] { 1, 2 })
  • Foo(new[] { 1, 2 })
  • Foo({ 1, 2 }) is not compilable
  • Foo(new int[0])
  • Foo(new int[] { })
  • Foo({}) is not compilable

How do I properly set the permgen size?

Completely removed from java 8 +
Partially removed from java 7 (interned Strings for example)
source

Chrome refuses to execute an AJAX script due to wrong MIME type

FYI, I've got the same error from Chrome console. I thought my AJAX function causing it, but I uncommented my minified script from /javascripts/ajax-vanilla.min.js to /javascripts/ajax-vanilla.js. But in reality the source file was at /javascripts/src/ajax-vanilla.js. So in Chrome you getting bad MIME type error even if the file cannot be found. In this case, the error message is described as text/plain bad MIME type.

How to set image name in Dockerfile?

Here is another version if you have to reference a specific docker file:

version: "3"
services:
  nginx:
    container_name: nginx
    build:
      context: ../..
      dockerfile: ./docker/nginx/Dockerfile
    image: my_nginx:latest

Then you just run

docker-compose build

How to disable input conditionally in vue.js

Can use this add condition.

  <el-form-item :label="Amount ($)" style="width:100%"  >
            <template slot-scope="scoped">
            <el-input-number v-model="listQuery.refAmount" :disabled="(rowData.status !== 1 ) === true" ></el-input-number>
            </template>
          </el-form-item>

Array and string offset access syntax with curly braces is deprecated

It's really simple to fix the issue, however keep in mind that you should fork and commit your changes for each library you are using in their repositories to help others as well.

Let's say you have something like this in your code:

$str = "test";
echo($str{0});

since PHP 7.4 curly braces method to get individual characters inside a string has been deprecated, so change the above syntax into this:

$str = "test";
echo($str[0]);

Fixing the code in the question will look something like this:

public function getRecordID(string $zoneID, string $type = '', string $name = ''): string
{
    $records = $this->listRecords($zoneID, $type, $name);
    if (isset($records->result[0]->id)) {
        return $records->result[0]->id;
    }
    return false;
}

invalid types 'int[int]' for array subscript

You are subscripting a three-dimensional array myArray[10][10][10] four times myArray[i][t][x][y]. You will probably need to add another dimension to your array. Also consider a container like Boost.MultiArray, though that's probably over your head at this point.

Difference between dict.clear() and assigning {} in Python

Mutating methods are always useful if the original object is not in scope:

def fun(d):
    d.clear()
    d["b"] = 2

d={"a": 2}
fun(d)
d          # {'b': 2}

Re-assigning the dictionary would create a new object and wouldn't modify the original one.

How to delete file from public folder in laravel 5.1

the easiest way for you to delete the image of the news is using the model event like below and the model delete the image if the news deleted

at first you should import this in top of the model class use Illuminate\Support\Facades\Storage after that in the model class News you should do this

public static function boot(){
    parent::boot();

    static::deleting(function ($news) {
          Storage::disk('public')->delete("{$news->image}");
    })
}

or you can delete the image in your controller with this command

Storage::disk('public')->delete("images/news/{$news->file_name}");

but you should know that the default disk is public but if you create folder in the public folder and put the image on that you should set the folder name before $news->file_name

VirtualBox Cannot register the hard disk already exists

1 - Open the files '.vbox' and '.vbox-prev' (if exist) files in any text editor and replace the first character of HardDisk uuid (take note to revert this change on step 6)

Example: nano /home/virtualbox/WindowsServer/WindowsServer.vbox

Change:

<HardDisks>
        <HardDisk uuid="{3ebaa9b6-8318-4b81-b853-8f30dd278bdc}" location="/home/virtualbox/WindowsServer/WindowsServer.vdi" format="VDI" type="Normal"/>

To:

<HardDisks>
        <HardDisk uuid="{2ebaa9b6-8318-4b81-b853-8f30dd278bdc}" location="/home/virtualbox/WindowsServer/WindowsServer.vdi" format="VDI" type="Normal"/>

2 - Reboot machine

4 - Stop Virtual Machine (if started)

5 - On terminal:

su vbox
cd /home/virtualbox/WindowsServer/
VBoxManage modifyhd WindowsServer.vdi --resize SIZE
exit
exit

change SIZE for a number in Megabytes, example 80000 (80GB)

6 - Open again the files '.vbox' and '.vbox-prev' (if exist) files in any text editor and replace the first character of HardDisk uuid whith the original value

Example: nano /home/virtualbox/WindowsServer/WindowsServer.vbox

Change:

<HardDisks>
        <HardDisk uuid="{2ebaa9b6-8318-4b81-b853-8f30dd278bdc}" location="/home/virtualbox/WindowsServer/WindowsServer.vdi" format="VDI" type="Normal"/>

To:

<HardDisks>
        <HardDisk uuid="{3ebaa9b6-8318-4b81-b853-8f30dd278bdc}" location="/home/virtualbox/WindowsServer/WindowsServer.vdi" format="VDI" type="Normal"/>

7 - Reboot machine

MySQL: What's the difference between float and double?

Float has 32 bit (4 bytes) with 8 places accuracy. Double has 64 bit (8 bytes) with 16 places accuracy.

If you need better accuracy, use Double instead of Float.

Jackson and generic type reference

I modified rushidesai1's answer to include a working example.

JsonMarshaller.java

import java.io.*;
import java.util.*;

public class JsonMarshaller<T> {
    private static ClassLoader loader = JsonMarshaller.class.getClassLoader();

    public static void main(String[] args) {
        try {
            JsonMarshallerUnmarshaller<Station> marshaller = new JsonMarshallerUnmarshaller<>(Station.class);
            String jsonString = read(loader.getResourceAsStream("data.json"));
            List<Station> stations = marshaller.unmarshal(jsonString);
            stations.forEach(System.out::println);
            System.out.println(marshaller.marshal(stations));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @SuppressWarnings("resource")
    public static String read(InputStream ios) {
        return new Scanner(ios).useDelimiter("\\A").next(); // Read the entire file
    }
}

Output

Station [id=123, title=my title, name=my name]
Station [id=456, title=my title 2, name=my name 2]
[{"id":123,"title":"my title","name":"my name"},{"id":456,"title":"my title 2","name":"my name 2"}]

JsonMarshallerUnmarshaller.java

import java.io.*;
import java.util.List;

import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.introspect.JacksonAnnotationIntrospector;

public class JsonMarshallerUnmarshaller<T> {
    private ObjectMapper mapper;
    private Class<T> targetClass;

    public JsonMarshallerUnmarshaller(Class<T> targetClass) {
        AnnotationIntrospector introspector = new JacksonAnnotationIntrospector();

        mapper = new ObjectMapper();
        mapper.getDeserializationConfig().with(introspector);
        mapper.getSerializationConfig().with(introspector);

        this.targetClass = targetClass;
    }

    public List<T> unmarshal(String jsonString) throws JsonParseException, JsonMappingException, IOException {
        return parseList(jsonString, mapper, targetClass);
    }

    public String marshal(List<T> list) throws JsonProcessingException {
        return mapper.writeValueAsString(list);
    }

    public static <E> List<E> parseList(String str, ObjectMapper mapper, Class<E> clazz)
            throws JsonParseException, JsonMappingException, IOException {
        return mapper.readValue(str, listType(mapper, clazz));
    }

    public static <E> List<E> parseList(InputStream is, ObjectMapper mapper, Class<E> clazz)
            throws JsonParseException, JsonMappingException, IOException {
        return mapper.readValue(is, listType(mapper, clazz));
    }

    public static <E> JavaType listType(ObjectMapper mapper, Class<E> clazz) {
        return mapper.getTypeFactory().constructCollectionType(List.class, clazz);
    }
}

Station.java

public class Station {
    private long id;
    private String title;
    private String name;

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return String.format("Station [id=%s, title=%s, name=%s]", id, title, name);
    }
}

data.json

[{
  "id": 123,
  "title": "my title",
  "name": "my name"
}, {
  "id": 456,
  "title": "my title 2",
  "name": "my name 2"
}]

String parsing in Java with delimiter tab "\t" using split

You can use yourstring.split("\x09"); I tested it, and it works.

How to change the font color of a disabled TextBox?

Just handle Enable changed and set it to the color you need

private void TextBoxName_EnabledChanged(System.Object sender, System.EventArgs e)
{
    ((TextBox)sender).ForeColor = Color.Black;
}

How To Show And Hide Input Fields Based On Radio Button Selection

***This will work.........
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript">
 window.onload = function() {
    document.getElementById('ifYes').style.display = 'none';
    document.getElementById('ifNo').style.display = 'none';
}
function yesnoCheck() {
    if (document.getElementById('yesCheck').checked) {
        document.getElementById('ifYes').style.display = 'block';
        document.getElementById('ifNo').style.display = 'none';
        document.getElementById('redhat1').style.display = 'none';
        document.getElementById('aix1').style.display = 'none';
    } 
    else if(document.getElementById('noCheck').checked) {
        document.getElementById('ifNo').style.display = 'block';
        document.getElementById('ifYes').style.display = 'none';
        document.getElementById('redhat1').style.display = 'none';
        document.getElementById('aix1').style.display = 'none';
   }
}
function yesnoCheck1() {
   if(document.getElementById('redhat').checked) {
       document.getElementById('redhat1').style.display = 'block';
       document.getElementById('aix1').style.display = 'none';
    }
   if(document.getElementById('aix').checked) {
       document.getElementById('aix1').style.display = 'block';
       document.getElementById('redhat1').style.display = 'none';
    }
}
</script>
</head>
<body>
Select os :<br>
windows
<input type="radio" onclick="javascript:yesnoCheck();" name="yesno" id="yesCheck"/>Unix
<input type="radio" onclick="javascript:yesnoCheck();" name="yesno" id="noCheck"/>
<br>
<div id="ifYes" style="display:none">
Windows 2008<input type="radio" name="win" value="2008"/>
Windows 2012<input type="radio" name="win" value="2012"/>
</div>
<div id="ifNo" style="display:none">
Red Hat<input type="radio" name="unix" onclick="javascript:yesnoCheck1();"value="2008" 

id="redhat"/>
AIX<input type="radio" name="unix" onclick="javascript:yesnoCheck1();"  
value="2012" id="aix"/>
</div>
<div id="redhat1" style="display:none">
Red Hat 6.0<input type="radio" name="redhat" value="2008" id="redhat6.0"/>
Red Hat 6.1<input type="radio" name="redhat" value="2012" id="redhat6.1"/>
</div>
<div id="aix1" style="display:none">
aix 6.0<input type="radio" name="aix" value="2008" id="aix6.0"/>
aix 6.1<input type="radio" name="aix" value="2012" id="aix6.1"/
</div>
</body> 
</html>***

How do we determine the number of days for a given month in python

Just for the sake of academic interest, I did it this way...

(dt.replace(month = dt.month % 12 +1, day = 1)-timedelta(days=1)).day

String concatenation of two pandas columns

You could also use

df['bar'] = df['bar'].str.cat(df['foo'].values.astype(str), sep=' is ')

ExecJS and could not find a JavaScript runtime

Don't Use RubyRacer as it is bad on memory. Installing Node.js as suggested by some people here is a better idea.

This list of available runtimes that can be used by ExecJs Library also documents the use of Node.js

https://github.com/sstephenson/execjs

So, Node.js is not an overkill, and much better solution than using the RubyRacer.

span with onclick event inside a tag

use onmouseup

try something like this

        <html>
        <head>
        <script type="text/javascript">
        function hide(){
        document.getElementById('span_hide').style.display="none";
        }
        </script>
        </head>

        <body>
        <a href="page" style="text-decoration:none;display:block;">
        <span   onmouseup="hide()" id="span_hide">Hide me</span>
        </a>
        </body>
        </html>

EDIT:

          <html>
        <head>
        <script type="text/javascript">
        $(document).ready(function(){
         $("a").click(function () { 
         $(this).fadeTo("fast", .5).removeAttr("href"); 
        });
        });
        function hide(){
        document.getElementById('span_hide').style.display="none";
        }
        </script>
        </head>

        <body>
        <a href="page.html" style="text-decoration:none;display:block;" onclick="return false" >
        <span   onmouseup="hide()" id="span_hide">Hide me</span>
        </a>
        </body>
        </html>

Given an RGB value, how do I create a tint (or shade)?

I'm currently experimenting with canvas and pixels... I'm finding this logic works out for me better.

  1. Use this to calculate the grey-ness ( luma ? )
  2. but with both the existing value and the new 'tint' value
  3. calculate the difference ( I found I did not need to multiply )
  4. add to offset the 'tint' value

    var grey =  (r + g + b) / 3;    
    var grey2 = (new_r + new_g + new_b) / 3;
    
    var dr =  grey - grey2 * 1;    
    var dg =  grey - grey2 * 1    
    var db =  grey - grey2 * 1;  
    
    tint_r = new_r + dr;    
    tint_g = new_g + dg;   
    tint_b = new_b _ db;
    

or something like that...

Image vs Bitmap class

Image provides an abstract access to an arbitrary image , it defines a set of methods that can loggically be applied upon any implementation of Image. Its not bounded to any particular image format or implementation . Bitmap is a specific implementation to the image abstract class which encapsulate windows GDI bitmap object. Bitmap is just a specific implementation to the Image abstract class which relay on the GDI bitmap Object.

You could for example , Create your own implementation to the Image abstract , by inheriting from the Image class and implementing the abstract methods.

Anyway , this is just a simple basic use of OOP , it shouldn't be hard to catch.

IOError: [Errno 22] invalid mode ('r') or filename: 'c:\\Python27\test.txt'

\t is a tab character. Use a raw string instead:

test_file=open(r'c:\Python27\test.txt','r')

or double the slashes:

test_file=open('c:\\Python27\\test.txt','r')

or use forward slashes instead:

test_file=open('c:/Python27/test.txt','r')

How do I implement Toastr JS?

I investigate i knew that the jquery script need to load in order that why it not worked in your case. Because $ symbol mentioned in code not understand unless you load Jquery 1.9.1 at first. Load like follows

<script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>
<script src="http://code.jquery.com/jquery-migrate-1.2.1.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/toastr.js/2.0.1/css/toastr.css" rel="stylesheet"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/toastr.js/2.0.1/js/toastr.js"></script>

Then it will work fine

How Does Modulus Divison Work

Very simple: a % b is defined as the remainder of the division of a by b.

See the wikipedia article for more examples.

Text Progress Bar in the Console

I am using progress from reddit. I like it because it can print progress for every item in one line, and it shouldn't erase printouts from the program.

Edit: fixed link

Command to find information about CPUs on a UNIX machine

Firstly, it probably depends which version of Solaris you're running, but also what hardware you have.

On SPARC at least, you have psrinfo to show you processor information, which run on its own will show you the number of CPUs the machine sees. psrinfo -p shows you the number of physical processors installed. From that you can deduce the number of threads/cores per physical processors.

prtdiag will display a fair bit of info about the hardware in your machine. It looks like on a V240 you do get memory channel info from prtdiag, but you don't on a T2000. I guess that's an architecture issue between UltraSPARC IIIi and UltraSPARC T1.

How do I detect if Python is running as a 64-bit application?

import platform
platform.architecture()

From the Python docs:

Queries the given executable (defaults to the Python interpreter binary) for various architecture information.

Returns a tuple (bits, linkage) which contain information about the bit architecture and the linkage format used for the executable. Both values are returned as strings.

How do I add files and folders into GitHub repos?

Simple solution:

git init
git add =A
git commit -m "your commit"
git push -u origin master

if you want add folder to existing repo ..then add folder to local project code

git rm --cached ./folderName
 git add ./folderName

after that

git status
git commit -m "your commit"
git push -u origin master

How do I sleep for a millisecond in Perl?

From the Perldoc page on sleep:

For delays of finer granularity than one second, the Time::HiRes module (from CPAN, and starting from Perl 5.8 part of the standard distribution) provides usleep().

Actually, it provides usleep() (which sleeps in microseconds) and nanosleep() (which sleeps in nanoseconds). You may want usleep(), which should let you deal with easier numbers. 1 millisecond sleep (using each):

use strict;
use warnings;

use Time::HiRes qw(usleep nanosleep);

# 1 millisecond == 1000 microseconds
usleep(1000);
# 1 microsecond == 1000 nanoseconds
nanosleep(1000000);

If you don't want to (or can't) load a module to do this, you may also be able to use the built-in select() function:

# Sleep for 250 milliseconds
select(undef, undef, undef, 0.25);

JavaScript/jQuery - How to check if a string contain specific words

indexOf/includes should not be used for finding whole words:

It does not know the difference between find a word or just a part of a word:

"has a word".indexOf('wor')  // 6
"has a word".includes('wor') // true

Check if a single word (whole word) is in the string

Find a real whole word, not just if the letters of that word are somewhere in the string.

_x000D_
_x000D_
const wordInString = (s, word) => new RegExp('\\b' + word + '\\b', 'i').test(s);

// tests
[
  '',            // true
  ' ',           // true
  'did',         // true
  'id',          // flase
  'yo ',         // flase
  'you',         // true
  'you not'      // true
].forEach(q => console.log(
  wordInString('dID You, or did you NOt, gEt WHy?', q) 
))

console.log(
  wordInString('did you, or did you not, get why?', 'you') // true
)
_x000D_
_x000D_
_x000D_

Check if all words are in the string

_x000D_
_x000D_
var stringHasAll = (s, query) => 
  // convert the query to array of "words" & checks EVERY item is contained in the string
  query.split(' ').every(q => new RegExp('\\b' + q + '\\b', 'i').test(s)); 


// tests
[
  '',            // true
  ' ',           // true
  'aa',          // true
  'aa ',         // true
  ' aa',         // true
  'd b',         // false
  'aaa',         // false
  'a b',         // false
  'a a a a a ',  // false
].forEach(q => console.log(
  stringHasAll('aA bB cC dD', q) 
))
_x000D_
_x000D_
_x000D_

Eclipse error: 'Failed to create the Java Virtual Machine'

The simple way to fix this problem is just to delete or rename your eclipse.ini file. Try it first. If this method does not resolve your problem, try the solutions described below.

Other ways to fix it:

Solution 1

Add a string into the eclipse.ini file which change a destination of the javaw.exe file. The main thing is that this string must be placed above the string "-vmargs"!

-vm
C:\Program Files\Java\jdk1.6.0_22\bin\javaw.exe 

Solution 2

Remove the value of –launcher.XXMaxPermSize, like 256m.

Solution 3

Remove or decrease the values of Xms and Xmx:

-Xms384m 
-Xmx384m

Integer ASCII value to character in BASH using printf

This works (with the value in octal):

$ printf '%b' '\101'
A

even for (some: don't go over 7) sequences:

$ printf '%b' '\'{101..107}
ABCDEFG

A general construct that allows (decimal) values in any range is:

$ printf '%b' $(printf '\\%03o' {65..122})
ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz

Or you could use the hex values of the characters:

$ printf '%b' $(printf '\\x%x' {65..122})
ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz

You also could get the character back with xxd (use hexadecimal values):

$ echo "41" | xxd -p -r
A

That is, one action is the reverse of the other:

$ printf "%x" "'A" | xxd -p -r
A

And also works with several hex values at once:

$ echo "41 42 43 44 45 46 47 48 49 4a" | xxd -p -r
ABCDEFGHIJ

or sequences (printf is used here to get hex values):

$ printf '%x' {65..90} | xxd -r -p 
ABCDEFGHIJKLMNOPQRSTUVWXYZ

Or even use awk:

$ echo 65 | awk '{printf("%c",$1)}'
A

even for sequences:

$ seq 65 90 | awk '{printf("%c",$1)}'
ABCDEFGHIJKLMNOPQRSTUVWXYZ

How can I add a string to the end of each line in Vim?

If u want to add Hello world at the end of each line:

:%s/$/HelloWorld/

If you want to do this for specific number of line say, from 20 to 30 use:

:20,30s/$/HelloWorld/

If u want to do this at start of each line then use:

:20,30s/^/HelloWorld/

Google Maps API throws "Uncaught ReferenceError: google is not defined" only when using AJAX

The API can't be loaded after the document has finished loading by default, you'll need to load it asynchronous.

modify the page with the map:

<div id="map_canvas" style="height: 354px; width:713px;"></div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false&callback=initialize"></script>
<script>
var directionsDisplay,
    directionsService,
    map;

function initialize() {
  var directionsService = new google.maps.DirectionsService();
  directionsDisplay = new google.maps.DirectionsRenderer();
  var chicago = new google.maps.LatLng(41.850033, -87.6500523);
  var mapOptions = { zoom:7, mapTypeId: google.maps.MapTypeId.ROADMAP, center: chicago }
  map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
  directionsDisplay.setMap(map);
}

</script>

For more details take a look at: https://stackoverflow.com/questions/14184956/async-google-maps-api-v3-undefined-is-not-a-function/14185834#14185834

Example: http://jsfiddle.net/doktormolle/zJ5em/

How to run a class from Jar which is not the Main-Class in its Manifest file

You can execute any class which has a public final static main method from a JAR file, even if the jar file has a Main-Class defined.

Execute Main-Class:

java -jar MyJar.jar  // will execute the Main-Class

Execute another class with a public static void main method:

java -cp MyJar.jar com.mycomp.myproj.AnotherClassWithMainMethod

Note: the first uses -jar, the second uses -cp.

What's the idiomatic syntax for prepending to a short python list?

If you can go the functional way, the following is pretty clear

new_list = [x] + your_list

Of course you haven't inserted x into your_list, rather you have created a new list with x preprended to it.

Filter Linq EXCEPT on properties

I use an extension method for Except, that allows you to compare Apples with Oranges as long as they both have something common that can be used to compare them, like an Id or Key.

public static class ExtensionMethods
{
    public static IEnumerable<TA> Except<TA, TB, TK>(
        this IEnumerable<TA> a,
        IEnumerable<TB> b,
        Func<TA, TK> selectKeyA,
        Func<TB, TK> selectKeyB, 
        IEqualityComparer<TK> comparer = null)
    {
        return a.Where(aItem => !b.Select(bItem => selectKeyB(bItem)).Contains(selectKeyA(aItem), comparer));
    }
}

then use it something like this:

var filteredApps = unfilteredApps.Except(excludedAppIds, a => a.Id, b => b);

the extension is very similar to ColinE 's answer, it's just packaged up into a neat extension that can be reused without to much mental overhead.

How to get the body's content of an iframe in Javascript?

Using JQuery, try this:

$("#id_description_iframe").contents().find("body").html()

How to check if a subclass is an instance of a class at runtime?

If there is polymorphism such as checking SQLRecoverableException vs SQLException, it can be done like that.

try {
    // sth may throw exception
    ....
} catch (Exception e) {
    if(SQLException.class.isAssignableFrom(e.getCause().getClass()))
    {
        // do sth
        System.out.println("SQLException occurs!");
    }
}

Simply say,

ChildClass child= new ChildClass();
if(ParentClass.class.isAssignableFrom(child.getClass()))
{
    // do sth
    ...
}

horizontal scrollbar on top and bottom of table

Expanding on StanleyH's answer, and trying to find the minimum required, here is what I implemented:

JavaScript (called once from somewhere like $(document).ready()):

function doubleScroll(){
        $(".topScrollVisible").scroll(function(){
            $(".tableWrapper")
                .scrollLeft($(".topScrollVisible").scrollLeft());
        });
        $(".tableWrapper").scroll(function(){
            $(".topScrollVisible")
                .scrollLeft($(".tableWrapper").scrollLeft());
        });
}

HTML (note that the widths will change the scroll bar length):

<div class="topScrollVisible" style="overflow-x:scroll">
    <div class="topScrollTableLength" style="width:1520px; height:20px">
    </div>
</div>
<div class="tableWrapper" style="overflow:auto; height:100%;">
    <table id="myTable" style="width:1470px" class="myTableClass">
...
    </table>

That's it.

How does a hash table work?

This is how it works in my understanding:

Here's an example: picture the entire table as a series of buckets. Suppose you have an implementation with alpha-numeric hash-codes and have one bucket for each letter of the alphabet. This implementation puts each item whose hash code begins with a particular letter in the corresponding bucket.

Let's say you have 200 objects, but only 15 of them have hash codes that begin with the letter 'B.' The hash table would only need to look up and search through the 15 objects in the 'B' bucket, rather than all 200 objects.

As far as calculating the hash code, there is nothing magical about it. The goal is just to have different objects return different codes and for equal objects to return equal codes. You could write a class that always returns the same integer as a hash-code for all instances, but you would essentially destroy the usefulness of a hash-table, as it would just become one giant bucket.

How to remove all white spaces in java

String a="string with                multi spaces ";

String b= a.replace("    "," ").replace("   "," ").replace("  "," ").replace("   "," ").replace("  "," ");

//it work fine with any spaces

How to iterate through a list of objects in C++

You're close.

std::list<Student>::iterator it;
for (it = data.begin(); it != data.end(); ++it){
    std::cout << it->name;
}

Note that you can define it inside the for loop:

for (std::list<Student>::iterator it = data.begin(); it != data.end(); ++it){
    std::cout << it->name;
}

And if you are using C++11 then you can use a range-based for loop instead:

for (auto const& i : data) {
    std::cout << i.name;
}

Here auto automatically deduces the correct type. You could have written Student const& i instead.

How do I check what version of Python is running my script?

The simplest way

Just type python in your terminal and you can see the version as like following

desktop:~$ python
Python 2.7.6 (default, Jun 22 2015, 18:00:18) 
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> 

Module not found: Error: Can't resolve 'core-js/es6'

I found possible answer. You have core-js version 3.0, and this version doesn't have separate folders for ES6 and ES7; that's why the application cannot find correct paths.

To resolve this error, you can downgrade the core-js version to 2.5.7. This version produces correct catalogs structure, with separate ES6 and ES7 folders.

To downgrade the version, simply run:

npm i -S [email protected]

In my case, with Angular, this works ok.

Get escaped URL parameter

Based on the 999's answer:

function getURLParameter(name) {
    return decodeURIComponent(
        (location.search.match(RegExp("[?|&]"+name+'=(.+?)(&|$)'))||[,null])[1]
    );  
}

Changes:

  • decodeURI() is replaced with decodeURIComponent()
  • [?|&] is added at the beginning of the regexp

Gets byte array from a ByteBuffer in java

This is a simple way to get a byte[], but part of the point of using a ByteBuffer is avoiding having to create a byte[]. Perhaps you can get whatever you wanted to get from the byte[] directly from the ByteBuffer.

socket programming multiple client to one server

This is the echo server handling multiple clients... Runs fine and good using Threads

// echo server
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;


public class Server_X_Client {
public static void main(String args[]){


    Socket s=null;
    ServerSocket ss2=null;
    System.out.println("Server Listening......");
    try{
        ss2 = new ServerSocket(4445); // can also use static final PORT_NUM , when defined

    }
    catch(IOException e){
    e.printStackTrace();
    System.out.println("Server error");

    }

    while(true){
        try{
            s= ss2.accept();
            System.out.println("connection Established");
            ServerThread st=new ServerThread(s);
            st.start();

        }

    catch(Exception e){
        e.printStackTrace();
        System.out.println("Connection Error");

    }
    }

}

}

class ServerThread extends Thread{  

    String line=null;
    BufferedReader  is = null;
    PrintWriter os=null;
    Socket s=null;

    public ServerThread(Socket s){
        this.s=s;
    }

    public void run() {
    try{
        is= new BufferedReader(new InputStreamReader(s.getInputStream()));
        os=new PrintWriter(s.getOutputStream());

    }catch(IOException e){
        System.out.println("IO error in server thread");
    }

    try {
        line=is.readLine();
        while(line.compareTo("QUIT")!=0){

            os.println(line);
            os.flush();
            System.out.println("Response to Client  :  "+line);
            line=is.readLine();
        }   
    } catch (IOException e) {

        line=this.getName(); //reused String line for getting thread name
        System.out.println("IO Error/ Client "+line+" terminated abruptly");
    }
    catch(NullPointerException e){
        line=this.getName(); //reused String line for getting thread name
        System.out.println("Client "+line+" Closed");
    }

    finally{    
    try{
        System.out.println("Connection Closing..");
        if (is!=null){
            is.close(); 
            System.out.println(" Socket Input Stream Closed");
        }

        if(os!=null){
            os.close();
            System.out.println("Socket Out Closed");
        }
        if (s!=null){
        s.close();
        System.out.println("Socket Closed");
        }

        }
    catch(IOException ie){
        System.out.println("Socket Close Error");
    }
    }//end finally
    }
}

Also here is the code for the client.. Just execute this code for as many times as you want to create multiple client..

// A simple Client Server Protocol .. Client for Echo Server

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;

public class NetworkClient {

public static void main(String args[]) throws IOException{


    InetAddress address=InetAddress.getLocalHost();
    Socket s1=null;
    String line=null;
    BufferedReader br=null;
    BufferedReader is=null;
    PrintWriter os=null;

    try {
        s1=new Socket(address, 4445); // You can use static final constant PORT_NUM
        br= new BufferedReader(new InputStreamReader(System.in));
        is=new BufferedReader(new InputStreamReader(s1.getInputStream()));
        os= new PrintWriter(s1.getOutputStream());
    }
    catch (IOException e){
        e.printStackTrace();
        System.err.print("IO Exception");
    }

    System.out.println("Client Address : "+address);
    System.out.println("Enter Data to echo Server ( Enter QUIT to end):");

    String response=null;
    try{
        line=br.readLine(); 
        while(line.compareTo("QUIT")!=0){
                os.println(line);
                os.flush();
                response=is.readLine();
                System.out.println("Server Response : "+response);
                line=br.readLine();

            }



    }
    catch(IOException e){
        e.printStackTrace();
    System.out.println("Socket read Error");
    }
    finally{

        is.close();os.close();br.close();s1.close();
                System.out.println("Connection Closed");

    }

}
}

How to remove foreign key constraint in sql server?

Depending on the DB you are using there's a syntax or another.

If you're using Oracle you have to put what the other users told you:

ALTER TABLE table_name DROP CONSTRAINT fk_name;

But if you use MySQL then this will give you a syntax error, instead you can type:

ALTER TABLE table_name DROP INDEX fk_name;

What is the minimum length of a valid international phone number?

As per different sources, I think the minimum length in E-164 format depends on country to country. For eg:

  • For Israel: The minimum phone number length (excluding the country code) is 8 digits. - Official Source (Country Code 972)
  • For Sweden : The minimum number length (excluding the country code) is 7 digits. - Official Source? (country code 46)

  • For Solomon Islands its 5 for fixed line phones. - Source (country code 677)

... and so on. So including country code, the minimum length is 9 digits for Sweden and 11 for Israel and 8 for Solomon Islands.

Edit (Clean Solution): Actually, Instead of validating an international phone number by having different checks like length etc, you can use the Google's libphonenumber library. It can validate a phone number in E164 format directly. It will take into account everything and you don't even need to give the country if the number is in valid E164 format. Its pretty good! Taking an example:

String phoneNumberE164Format = "+14167129018"
PhoneNumberUtil phoneUtil = PhoneNumberUtil.getInstance();
try {
    PhoneNumber phoneNumberProto = phoneUtil.parse(phoneNumberE164Format, null);
    boolean isValid = phoneUtil.isValidNumber(phoneNumberProto); // returns true if valid
    if (isValid) {
        // Actions to perform if the number is valid
    } else {
        // Do necessary actions if its not valid 
    }
} catch (NumberParseException e) {
    System.err.println("NumberParseException was thrown: " + e.toString());
}

If you know the country for which you are validating the numbers, you don;t even need the E164 format and can specify the country in .parse function instead of passing null.

Reliable method to get machine's MAC address in C#

foreach (NetworkInterface nic in NetworkInterface.GetAllNetworkInterfaces())
{
     if (nic.OperationalStatus == OperationalStatus.Up)
     {
            PhysicalAddress Mac = nic.GetPhysicalAddress();
     }
}

Creating a segue programmatically

You have to link your code to the UIStoryboard that you're using. Make sure you go into YourViewController in your UIStoryboard, click on the border around it, and then set its identifier field to a NSString that you call in your code.

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" 
                                                     bundle:nil];
YourViewController *yourViewController = 
 (YourViewController *)
  [storyboard instantiateViewControllerWithIdentifier:@"yourViewControllerID"];
[self.navigationController pushViewController:yourViewController animated:YES];

A potentially dangerous Request.Form value was detected from the client

I see there's a lot written about this...and I didn't see this mentioned. This has been available since .NET Framework 4.5

The ValidateRequestMode setting for a control is a great option. This way the other controls on the page are still protected. No web.config changes needed.

 protected void Page_Load(object sender, EventArgs e)
 {
     txtMachKey.ValidateRequestMode = ValidateRequestMode.Disabled;
 }

ExpressJS How to structure an application?

This may be of interest:

https://github.com/flatiron/nconf

Hierarchical node.js configuration with files, environment variables, command-line arguments, and atomic object merging.

Removing items from a ListBox in VB.net

This worked for me.

Private Sub listbox_MouseDoubleClick(sender As Object, e As MouseEventArgs) 
        Handles listbox.MouseDoubleClick
        listbox.Items.RemoveAt(listbox.SelectedIndex.ToString())
    End Sub

Image re-size to 50% of original size in HTML

The percentage setting does not take into account the original image size. From w3schools :

In HTML 4.01, the width could be defined in pixels or in % of the containing element. In HTML5, the value must be in pixels.

Also, good practice advice from the same source :

Tip: Downsizing a large image with the height and width attributes forces a user to download the large image (even if it looks small on the page). To avoid this, rescale the image with a program before using it on a page.

Deprecated meaning?

Deprecated in general means "don't use it".
A deprecated function may or may not work, but it is not guaranteed to work.

What does void mean in C, C++, and C#?

Void is an incomplete type which, by definition, can't be an lvalue. That means it can't get assigned a value.

So it also can't hold any value.

Default settings Raspberry Pi /etc/network/interfaces

These are the default settings I have for /etc/network/interfaces (including WiFi settings) for my Raspberry Pi 1:

auto lo

iface lo inet loopback
iface eth0 inet dhcp

allow-hotplug wlan0
iface wlan0 inet manual
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp

How to send email in ASP.NET C#

MailMessage mm = new MailMessage(txtEmail.Text, txtTo.Text);
mm.Subject = txtSubject.Text;
mm.Body = txtBody.Text;
if (fuAttachment.HasFile)//file upload select or not
{
    string FileName = Path.GetFileName(fuAttachment.PostedFile.FileName);
    mm.Attachments.Add(new Attachment(fuAttachment.PostedFile.InputStream, FileName));
}
mm.IsBodyHtml = false;
SmtpClient smtp = new SmtpClient();
smtp.Host = "smtp.gmail.com";
smtp.EnableSsl = true;
NetworkCredential NetworkCred = new NetworkCredential(txtEmail.Text, txtPassword.Text);
smtp.UseDefaultCredentials = true;
smtp.Credentials = NetworkCred;
smtp.Port = 587;
smtp.Send(mm);
Response.write("Send Mail");

View Video: https://www.youtube.com/watch?v=bUUNv-19QAI

Can Json.NET serialize / deserialize to / from a stream?

I've written an extension class to help me deserializing from JSON sources (string, stream, file).

public static class JsonHelpers
{
    public static T CreateFromJsonStream<T>(this Stream stream)
    {
        JsonSerializer serializer = new JsonSerializer();
        T data;
        using (StreamReader streamReader = new StreamReader(stream))
        {
            data = (T)serializer.Deserialize(streamReader, typeof(T));
        }
        return data;
    }

    public static T CreateFromJsonString<T>(this String json)
    {
        T data;
        using (MemoryStream stream = new MemoryStream(System.Text.Encoding.Default.GetBytes(json)))
        {
            data = CreateFromJsonStream<T>(stream);
        }
        return data;
    }

    public static T CreateFromJsonFile<T>(this String fileName)
    {
        T data;
        using (FileStream fileStream = new FileStream(fileName, FileMode.Open))
        {
            data = CreateFromJsonStream<T>(fileStream);
        }
        return data;
    }
}

Deserializing is now as easy as writing:

MyType obj1 = aStream.CreateFromJsonStream<MyType>();
MyType obj2 = "{\"key\":\"value\"}".CreateFromJsonString<MyType>();
MyType obj3 = "data.json".CreateFromJsonFile<MyType>();

Hope it will help someone else.

What's the complete range for Chinese characters in Unicode?

The Unicode code blocks that the others answers gave certainly cover most of the Chinese Unicode characters, but check out some of these other code blocks, too.

CJK_UNIFIED_IDEOGRAPHS
CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A
CJK_UNIFIED_IDEOGRAPHS_EXTENSION_B
CJK_UNIFIED_IDEOGRAPHS_EXTENSION_C
CJK_UNIFIED_IDEOGRAPHS_EXTENSION_D
CJK_UNIFIED_IDEOGRAPHS_EXTENSION_E
CJK_COMPATIBILITY
CJK_COMPATIBILITY_FORMS
CJK_COMPATIBILITY_IDEOGRAPHS
CJK_COMPATIBILITY_IDEOGRAPHS_SUPPLEMENT
CJK_RADICALS_SUPPLEMENT
CJK_STROKES
CJK_SYMBOLS_AND_PUNCTUATION
ENCLOSED_CJK_LETTERS_AND_MONTHS
ENCLOSED_IDEOGRAPHIC_SUPPLEMENT
KANGXI_RADICALS
IDEOGRAPHIC_DESCRIPTION_CHARACTERS

See my fuller discussion here. And this site is convenient for browsing Unicode.

How to check if a column exists in Pandas

This will work:

if 'A' in df:

But for clarity, I'd probably write it as:

if 'A' in df.columns:

Simple jQuery, PHP and JSONP example?

$.ajax({

        type:     "GET",
        url: '<?php echo Base_url("user/your function");?>',
        data: {name: mail},
        dataType: "jsonp",
        jsonp: 'callback',
        jsonpCallback: 'chekEmailTaken',
        success: function(msg){
    }
});
return true;

In controller:

public function ajax_checkjp(){
$checkType = $_GET['name'];
echo $_GET['callback']. '(' . json_encode($result) . ');';  
}

Change Placeholder Text using jQuery

The plugin doesn't look very robust. If you call .placeholder() again, it creates a new Placeholder instance while events are still bound to the old one.

Looking at the code, it looks like you could do:

$("#serMemtb").attr("placeholder", "Type a name (Lastname, Firstname)").blur();

EDIT

placeholder is an HTML5 attribute, guess who's not supporting it?

Your plugin doesn't really seem to help you overcome the fact that IE doesn't support it, so while my solution works, your plugin doesn't. Why don't you find one that does.

Clear listview content?

I guess you passed a List or an Array to the Adapter. If you keep the instance of this added collection, you can do a

collection.clear();
listview.getAdapter().notifyDataSetChanged();

this'll work only if you instantiated the adapter with collection and it's the same instance.

Also, depending on the Adapter you extended, you may not be able to do this. SimpleAdapter is used for static data, thus it can't be updated after creation.

PS. not all Adapters have a clear() method. ArrayAdapter does, but ListAdapter or SimpleAdapter don't

*ngIf else if in template

Or maybe just use conditional chains with ternary operator. if … else if … else if … else chain.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Conditional_Operator#Conditional_chains

<ng-container *ngIf="isFirst ? first: isSecond ? second : third"></ng-container>

<ng-template #first></ng-template>
<ng-template #second></ng-template>
<ng-template #third></ng-template>

I like this aproach better.

Merging dataframes on index with pandas

You should be able to use join, which joins on the index as default. Given your desired result, you must use outer as the join type.

>>> df1.join(df2, how='outer')
            V1  V2
A 1/1/2012  12  15
  2/1/2012  14 NaN
  3/1/2012 NaN  21
B 1/1/2012  15  24
  2/1/2012   8   9
C 1/1/2012  17 NaN
  2/1/2012   9 NaN
D 1/1/2012 NaN   7
  2/1/2012 NaN  16

Signature: _.join(other, on=None, how='left', lsuffix='', rsuffix='', sort=False) Docstring: Join columns with other DataFrame either on index or on a key column. Efficiently Join multiple DataFrame objects by index at once by passing a list.

Merge two array of objects based on a key

You can recursively merge them into one as follows:

_x000D_
_x000D_
function mergeRecursive(obj1, obj2) {_x000D_
    for (var p in obj2) {_x000D_
        try {_x000D_
            // Property in destination object set; update its value._x000D_
            if (obj2[p].constructor == Object) {_x000D_
                obj1[p] = this.mergeRecursive(obj1[p], obj2[p]);_x000D_
_x000D_
            } else {_x000D_
                obj1[p] = obj2[p];_x000D_
_x000D_
            }_x000D_
_x000D_
        } catch (e) {_x000D_
            obj1[p] = obj2[p];_x000D_
_x000D_
        }_x000D_
    }_x000D_
    return obj1;_x000D_
}_x000D_
_x000D_
arr1 = [_x000D_
    { id: "abdc4051", date: "2017-01-24" },_x000D_
    { id: "abdc4052", date: "2017-01-22" }_x000D_
];_x000D_
arr2 = [_x000D_
    { id: "abdc4051", name: "ab" },_x000D_
    { id: "abdc4052", name: "abc" }_x000D_
];_x000D_
_x000D_
mergeRecursive(arr1, arr2)_x000D_
console.log(JSON.stringify(arr1))
_x000D_
_x000D_
_x000D_

Replace last occurrence of character in string

No need for jQuery nor regex assuming the character you want to replace exists in the string

Replace last char in a string

str = str.substring(0,str.length-2)+otherchar

Replace last underscore in a string

var pos = str.lastIndexOf('_');
str = str.substring(0,pos) + otherchar + str.substring(pos+1)

or use one of the regular expressions from the other answers

_x000D_
_x000D_
var str1 = "Replace the full stop with a questionmark."_x000D_
var str2 = "Replace last _ with another char other than the underscore _ near the end"_x000D_
_x000D_
// Replace last char in a string_x000D_
_x000D_
console.log(_x000D_
  str1.substring(0,str1.length-2)+"?"_x000D_
)  _x000D_
// alternative syntax_x000D_
console.log(_x000D_
  str1.slice(0,-1)+"?"_x000D_
)_x000D_
_x000D_
// Replace last underscore in a string _x000D_
_x000D_
var pos = str2.lastIndexOf('_'), otherchar = "|";_x000D_
console.log(_x000D_
  str2.substring(0,pos) + otherchar + str2.substring(pos+1)_x000D_
)_x000D_
// alternative syntax_x000D_
_x000D_
console.log(_x000D_
  str2.slice(0,pos) + otherchar + str2.slice(pos+1)_x000D_
)
_x000D_
_x000D_
_x000D_

How to get request URL in Spring Boot RestController

If you don't want any dependency on Spring's HATEOAS or javax.* namespace, use ServletUriComponentsBuilder to get URI of current request:

import org.springframework.web.util.UriComponentsBuilder;

ServletUriComponentsBuilder.fromCurrentRequest();
ServletUriComponentsBuilder.fromCurrentRequestUri();

How to set and reference a variable in a Jenkinsfile

I can' t comment yet but, just a hint: use try/catch clauses to avoid breaking the pipeline (if you are sure the file exists, disregard)

    pipeline {
        agent any
            stages {
                stage("foo") {
                    steps {
                        script {
                            try {                    
                                env.FILENAME = readFile 'output.txt'
                                echo "${env.FILENAME}"
                            }
                            catch(Exception e) {
                                //do something, e.g. echo 'File not found'
                            }
                        }
                   }
    }

Another hint (this was commented by @hao, and think is worth to share): you may want to trim like this readFile('output.txt').trim()

The Definitive C Book Guide and List

Warning!

This is a list of random books of diverse quality. In the view of some people (with some justification), it is no longer a list of recommended books. Some of the listed books contain blatantly incorrect statements or teach wrong/harmful practices. People who are aware of such books can edit this answer to help improve it. See The C book list has gone haywire. What to do with it?, and also Deleted question audit 2018.

Reference (All Levels)

  • The C Programming Language (2nd Edition) - Brian W. Kernighan and Dennis M. Ritchie (1988). Still a good, short but complete introduction to C (C90, not C99 or later versions), written by the inventor of C. However, the language has changed and good C style has developed in the last 25 years, and there are parts of the book that show its age.

  • C: A Reference Manual (5th Edition) - Samuel P. Harbison and Guy R. Steele (2002). An excellent reference book on C, up to and including C99. It is not a tutorial, and probably unfit for beginners. It's great if you need to write a compiler for C, as the authors had to do when they started.

  • C Pocket Reference (O'Reilly) - Peter Prinz and Ulla Kirch-Prinz (2002).

  • The comp.lang.c FAQ - Steve Summit. Web site with answers to many questions about C.

  • Various versions of the C language standards can be found here. There is an online version of the draft C11 standard.

  • The new C standard - an annotated reference (Free PDF) - Derek M. Jones (2009). The "new standard" referred to is the old C99 standard rather than C11.

  • Rationale for C99 Standard.


Beginner

  • C In Easy Steps (5th Edition) - Mike McGrath (2018). It is a good book for learning and referencing C.

  • Effective C - Robert C Seacord (2020). A good introduction to modern C, including chapters on dynamic memory allocation, on program structure, and on debugging, testing and analysis. It has some pointers toward probable C2x features.

Intermediate

  • Modern C — Jens Gustedt (2017 1st Edn; 2020 2nd Edn). Covers C in 5 levels (encounter, acquaintance, cognition, experience, ambition) from beginning C to advanced C. It covers C11 and C17, including threads and atomic access, which few other books do. Not all compilers recognize these features in all environments.

  • C Interfaces and Implementations - David R. Hanson (1997). Provides information on how to define a boundary between an interface and implementation in C in a generic and reusable fashion. It also demonstrates this principle by applying it to the implementation of common mechanisms and data structures in C, such as lists, sets, exceptions, string manipulation, memory allocators, and more. Basically, Hanson took all the code he'd written as part of building Icon and lcc and pulled out the best bits in a form that other people could reuse for their own projects. It's a model of good C programming using modern design techniques (including Liskov's data abstraction), showing how to organize a big C project as a bunch of useful libraries.

  • The C Puzzle Book - Alan R. Feuer (1998)

  • The Standard C Library - P.J. Plauger (1992). It contains the complete source code to an implementation of the C89 standard library, along with extensive discussions about the design and why the code is designed as shown.

  • 21st Century C: C Tips from the New School - Ben Klemens (2012). In addition to the C language, the book explains gdb, valgrind, autotools, and git. The comments on style are found in the last part (Chapter 6 and beyond).

  • Algorithms in C - Robert Sedgewick (1997). Gives you a real grasp of implementing algorithms in C. Very lucid and clear; will probably make you want to throw away all of your other algorithms books and keep this one.

  • Extreme C: Push the limits of what C and you can do - Kamran Amini (2019). This book builds on your existing C knowledge to help you become a more expert C programmer. You will gain insights into algorithm design, functions, and structures, and understand both multi-threading and multi-processing in a POSIX environment.

Expert


Uncategorized

  • Essential C (Free PDF) - Nick Parlante (2003). Note that this describes the C90 language at several points (e.g., in discussing // comments and placement of variable declarations at arbitrary points in the code), so it should be treated with some caution.

  • C Programming FAQs: Frequently Asked Questions - Steve Summit (1995). This is the book of the web site listed earlier. It doesn't cover C99 or the later standards.

  • C in a Nutshell - Peter Prinz and Tony Crawford (2005). Excellent book if you need a reference for C99.

  • Functional C - Pieter Hartel and Henk Muller (1997). Teaches modern practices that are invaluable for low-level programming, with concurrency and modularity in mind.

  • The Practice of Programming - Brian W. Kernighan and Rob Pike (1999). A very good book to accompany K&R. It uses C++ and Java too.

  • C Traps and Pitfalls by A. Koenig (1989). Very good, but the C style pre-dates standard C, which makes it less recommendable these days.

    Some have argued for the removal of 'Traps and Pitfalls' from this list because it has trapped some people into making mistakes; others continue to argue for its inclusion. Perhaps it should be regarded as an 'expert' book because it requires a moderately extensive knowledge of C to understand what's changed since it was published.

  • MISRA-C - industry standard published and maintained by the Motor Industry Software Reliability Association. Covers C89 and C99.

    Although this isn't a book as such, many programmers recommend reading and implementing as much of it as possible. MISRA-C was originally intended as guidelines for safety-critical applications in particular, but it applies to any area of application where stable, bug-free C code is desired (who doesn't want fewer bugs?). MISRA-C is becoming the de facto standard in the whole embedded industry and is getting increasingly popular even in other programming branches. There are (at least) three publications of the standard (1998, 2004, and the current version from 2012). There is also a MISRA Compliance Guidelines document from 2016, and MISRA C:2012 Amendment 1 — Additional Security Guidelines for MISRA C:2012 (published in April 2016).

    Note that some of the strictures in the MISRA rules are not appropriate to every context. For example, directive 4.12 states "Dynamic memory allocation shall not be used". This is appropriate in the embedded systems for which the MISRA rules are designed; it is not appropriate everywhere. (Compilers, for instance, generally use dynamic memory allocation for things like symbol tables, and to do without dynamic memory allocation would be difficult, if not preposterous.)

  • Archived lists of ACCU-reviewed books on Beginner's C (116 titles) from 2007 and Advanced C (76 titles) from 2008. Most of these don't look to be on the main site anymore, and you can't browse that by subject anyway.


Warnings

There is a list of books and tutorials to be cautious about at the ISO 9899 Wiki, which is not itself formally associated with ISO or the C standard, but contains information about the C standard (though it hails the release of ISO 9899:2011 and does not mention the release of ISO 9899:2018).

Be wary of books written by Herbert Schildt. In particular, you should stay away from C: The Complete Reference (4th Edition, 2000), known in some circles as C: The Complete Nonsense.

Also do not use the book Let Us C (16th Edition, 2017) by Yashwant Kanetkar. Many people view it as an outdated book that teaches Turbo C and has lots of obsolete, misleading and incorrect material. For example, page 137 discusses the expected output from printf("%d %d %d\n", a, ++a, a++) and does not categorize it as undefined behaviour as it should. It also consistently promotes unportable and buggy coding practices, such as using gets, %[\n]s in scanf, storing return value of getchar in a variable of type char or using fflush on stdin.

Learn C The Hard Way (2015) by Zed Shaw. A book with mixed reviews. A critique of this book by Tim Hentenaar:

To summarize my views, which are laid out below, the author presents the material in a greatly oversimplified and misleading way, the whole corpus is a bundled mess, and some of the opinions and analyses he offers are just plain wrong. I've tried to view this book through the eyes of a novice, but unfortunately I am biased by years of experience writing code in C. It's obvious to me that either the author has a flawed understanding of C, or he's deliberately oversimplifying to the point where he's actually misleading the reader (intentionally or otherwise).

"Learn C The Hard Way" is not a book that I could recommend to someone who is both learning to program and learning C. If you're already a competent programmer in some other related language, then it represents an interesting and unusual exposition on C, though I have reservations about parts of the book. Jonathan Leffler


Outdated


Other contributors, not necessarily credited in the revision history, include:
Alex Lockwood, Ben Jackson, Bubbles, claws, coledot, Dana Robinson, Daniel Holden, desbest, Dervin Thunk, dwc, Erci Hou, Garen, haziz, Johan Bezem, Jonathan Leffler, Joshua Partogi, Lucas, Lundin, Matt K., mossplix, Matthieu M., midor, Nietzche-jou, Norman Ramsey, r3st0r3, ridthyself, Robert S. Barnes, Steve Summit, Tim Ring, Tony Bai, VMAtm

Faster alternative in Oracle to SELECT COUNT(*) FROM sometable

You can create a fast refresh materialized view to store the count.

Example:

create table sometable (
id number(10) not null primary key
, name varchar2(100) not null);

create materialized view log on sometable with rowid including new values;

create materialized view sometable_count
refresh on commit
as
select count(*) count
from   sometable;

insert into sometable values (1,'Raymond');
insert into sometable values (2,'Hans');

commit;

select count from sometable_count; 

It will slow mutations on table sometable a bit but the counting will become a lot faster.

Excel telling me my blank cells aren't blank

'Select non blank cells
Selection.SpecialCells(xlCellTypeConstants, 23).Select
' REplace tehse blank look like cells to something uniqu
Selection.Replace What:="", Replacement:="TOBEDELETED", LookAt:=xlWhole, _
    SearchOrder:=xlByRows, MatchCase:=False, SearchFormat:=False, _
    ReplaceFormat:=False
'now replace this uique text to nothing and voila all will disappear
Selection.Replace What:="TOBEDELETED", Replacement:="", LookAt:=xlWhole, _
    SearchOrder:=xlByRows, MatchCase:=False, SearchFormat:=False, _
    ReplaceFormat:=False

Difference between h:button and h:commandButton

h:button - clicking on a h:button issues a bookmarkable GET request.

h:commandbutton - Instead of a get request, h:commandbutton issues a POST request which sends the form data back to the server.

Excel formula to display ONLY month and year?

First thing first. set the column in which you are working in by clicking on format cells->number-> date and then format e.g Jan-16 representing Jan, 1, 2016. and then apply either of the formulas above.

ExecuteNonQuery doesn't return results

Could you post the exact query? The ExecuteNonQuery method returns the @@ROWCOUNT Sql Server variable what ever it is after the last query has executed is what the ExecuteNonQuery method returns.

What is the significance of #pragma marks? Why do we need #pragma marks?

#pragma mark is used to tag the group of methods so you may easily find and detect methods from the Jump Bar. It may help you when your code files reach about 1000 lines and you want to find methods quickly through the category from Jump box.

In a long program it becomes difficult to remember and find a method name. So pragma mark allows you to categorize methods according to the work they do. For example, you tagged some tag for Table View Protocol Methods, AlertView Methods, Init Methods, Declaration etc.

#pragma mark is the facility for XCode but it has no impact on your code. It merely helps to make it easier to find methods while coding.

HTML5 record audio to file

Update now Chrome also supports MediaRecorder API from v47. The same thing to do would be to use it( guessing native recording method is bound to be faster than work arounds), the API is really easy to use, and you would find tons of answers as to how to upload a blob for the server.

Demo - would work in Chrome and Firefox, intentionally left out pushing blob to server...

Code Source


Currently, there are three ways to do it:

  1. as wav[ all code client-side, uncompressed recording], you can check out --> Recorderjs. Problem: file size is quite big, more upload bandwidth required.
  2. as mp3[ all code client-side, compressed recording], you can check out --> mp3Recorder. Problem: personally, I find the quality bad, also there is this licensing issue.
  3. as ogg [ client+ server(node.js) code, compressed recording, infinite hours of recording without browser crash ], you can check out --> recordOpus, either only client-side recording, or client-server bundling, the choice is yours.

    ogg recording example( only firefox):

    var mediaRecorder = new MediaRecorder(stream);
    mediaRecorder.start();  // to start recording.    
    ...
    mediaRecorder.stop();   // to stop recording.
    mediaRecorder.ondataavailable = function(e) {
        // do something with the data.
    }
    

    Fiddle Demo for ogg recording.

Securing a password in a properties file

enter image description here

Jasypt provides the org.jasypt.properties.EncryptableProperties class for loading, managing and transparently decrypting encrypted values in .properties files, allowing the mix of both encrypted and not-encrypted values in the same file.

http://www.jasypt.org/encrypting-configuration.html

By using an org.jasypt.properties.EncryptableProperties object, an application would be able to correctly read and use a .properties file like this:

datasource.driver=com.mysql.jdbc.Driver 
datasource.url=jdbc:mysql://localhost/reportsdb 
datasource.username=reportsUser 
datasource.password=ENC(G6N718UuyPE5bHyWKyuLQSm02auQPUtm) 

Note that the database password is encrypted (in fact, any other property could also be encrypted, be it related with database configuration or not).

How do we read this value? like this:

/*
* First, create (or ask some other component for) the adequate encryptor for   
* decrypting the values in our .properties file.   
*/  
StandardPBEStringEncryptor encryptor = new StandardPBEStringEncryptor();     
encryptor.setPassword("jasypt"); // could be got from web, env variable...    
/*   
* Create our EncryptableProperties object and load it the usual way.   
*/  
Properties props = new EncryptableProperties(encryptor);  
props.load(new FileInputStream("/path/to/my/configuration.properties"));

/*   
* To get a non-encrypted value, we just get it with getProperty...   
*/  
String datasourceUsername = props.getProperty("datasource.username");

/*   
* ...and to get an encrypted value, we do exactly the same. Decryption will   
* be transparently performed behind the scenes.   
*/ 
String datasourcePassword = props.getProperty("datasource.password");

 // From now on, datasourcePassword equals "reports_passwd"...

SQL Server String or binary data would be truncated

If you’re on SQL Server 2016-2017: to fix it, turn on trace flag 460

DBCC TRACEON(460, 1);
GO

and make sure you turn it off after:

DBCC TRACEOFF(460, 1);
GO

source

Pass element ID to Javascript function

The problem for me was as simple as just not knowing Javascript well. I was trying to pass the name of the id using double quotes, when I should have been using single. And it worked fine.

This worked:

validateSelectizeDropdown('#PartCondition')

This did not:

validateSelectizeDropdown("#PartCondition")

And the function:

    function validateSelectizeDropdown(name) {
    if ($(name).val() === "") {
         //do something
    }
}

Using python PIL to turn a RGB image into a pure black and white image

As Martin Thoma has said, you need to normally apply thresholding. But you can do this using simple vectorization which will run much faster than the for loop that is used in that answer.

The code below converts the pixels of an image into 0 (black) and 1 (white).

from PIL import Image
import numpy as np
import matplotlib.pyplot as plt

#Pixels higher than this will be 1. Otherwise 0.
THRESHOLD_VALUE = 200

#Load image and convert to greyscale
img = Image.open("photo.png")
img = img.convert("L")

imgData = np.asarray(img)
thresholdedData = (imgData > THRESHOLD_VALUE) * 1.0

plt.imshow(thresholdedData)
plt.show()

AWS ssh access 'Permission denied (publickey)' issue

Had the same issue. Permission denied (publickey) when trying to login in with 'ec2-user' or with 'root'.

Googled the AMI number of the machine image and it had the SSH login information right their on the Debian wiki page.

Hope this helps.

Difference between using bean id and name in Spring configuration file

Either one would work. It depends on your needs:
If your bean identifier contains special character(s) for example (/viewSummary.html), it wont be allowed as the bean id, because it's not a valid XML ID. In such cases you could skip defining the bean id and supply the bean name instead.
The name attribute also helps in defining aliases for your bean, since it allows specifying multiple identifiers for a given bean.

Use of alloc init instead of new

Very old question, but I've written some example just for fun — maybe you'll find it useful ;)

#import "InitAllocNewTest.h"

@implementation InitAllocNewTest

+(id)alloc{
    NSLog(@"Allocating...");
    return [super alloc];
}

-(id)init{
    NSLog(@"Initializing...");
    return [super init];
}

@end

In main function both statements:

[[InitAllocNewTest alloc] init];

and

[InitAllocNewTest new];

result in the same output:

2013-03-06 16:45:44.125 XMLTest[18370:207] Allocating...
2013-03-06 16:45:44.128 XMLTest[18370:207] Initializing...

chrome : how to turn off user agent stylesheet settings?

https://developers.google.com/chrome-developer-tools/docs/settings

  1. Open Chrome dev tools
  2. Click gear icon on bottom right
  3. In General section, check or uncheck "Show user agent styles".

Official reasons for "Software caused connection abort: socket write error"

ssl client side will throw such exception in below situation(I had tested), :

server is asked to authenticate client certificate, but the client provide a certificate which Extended Key Usage donot support client auth.

Where do I configure log4j in a JUnit test class?

You may want to look into to Simple Logging Facade for Java (SLF4J). It is a facade that wraps around Log4j that doesn't require an initial setup call like Log4j. It is also fairly easy to switch out Log4j for Slf4j as the API differences are minimal.

Scroll to the top of the page using JavaScript?

The equivalent solution in TypeScript may be as the following

   window.scroll({
      top: 0,
      left: 0,
      behavior: 'smooth'
    });

iOS 7: UITableView shows under status bar

If you are doing things programatically and are using a UITableViewController without a UINavigationController your best bet is to do the following in viewDidLoad:

Swift 3

self.tableView.contentInset = UIEdgeInsets(top: 20, left: 0, bottom: 0, right: 0)

Earlier Swift

self.tableView.contentInset = UIEdgeInsetsMake(20.0f, 0.0f, 0.0f, 0.0f);

The UITableViewController will still scroll behind the status bar but won't be under it when scrolled to the top.

How to Insert BOOL Value to MySQL Database

TRUE and FALSE are keywords, and should not be quoted as strings:

INSERT INTO first VALUES (NULL, 'G22', TRUE);
INSERT INTO first VALUES (NULL, 'G23', FALSE);

By quoting them as strings, MySQL will then cast them to their integer equivalent (since booleans are really just a one-byte INT in MySQL), which translates into zero for any non-numeric string. Thus, you get 0 for both values in your table.

Non-numeric strings cast to zero:

mysql> SELECT CAST('TRUE' AS SIGNED), CAST('FALSE' AS SIGNED), CAST('12345' AS SIGNED);
+------------------------+-------------------------+-------------------------+
| CAST('TRUE' AS SIGNED) | CAST('FALSE' AS SIGNED) | CAST('12345' AS SIGNED) |
+------------------------+-------------------------+-------------------------+
|                      0 |                       0 |                   12345 |
+------------------------+-------------------------+-------------------------+

But the keywords return their corresponding INT representation:

mysql> SELECT TRUE, FALSE;
+------+-------+
| TRUE | FALSE |
+------+-------+
|    1 |     0 |
+------+-------+

Note also, that I have replaced your double-quotes with single quotes as are more standard SQL string enclosures. Finally, I have replaced your empty strings for id with NULL. The empty string may issue a warning.

The entity cannot be constructed in a LINQ to Entities query

You can use this and it should be working --> You must use toList before making the new list using select:

db.Products
    .where(x=>x.CategoryID == categoryID).ToList()
    .select(x=>new Product { Name = p.Name}).ToList(); 

What are sessions? How do they work?

Simple Explanation by analogy

Imagine you are in a bank, trying to get some money out of your account. But it's dark; the bank is pitch black: there's no light and you can't see your hand in front of your face. You are surrounded by another 20 people. They all look the same. And everybody has the same voice. And everyone is a potential bad guy. In other words, HTTP is stateless.

This bank is a funny type of bank - for the sake of argument here's how things work:

  1. you wait in line (or on-line) and you talk to the teller: you make a request to withdraw money, and then
  2. you have to wait briefly on the sofa, and 20 minutes later
  3. you have to go and actually collect your money from the teller.

But how will the teller tell you apart from everyone else?

The teller can't see or readily recognise you, remember, because the lights are all out. What if your teller gives your $10,000 withdrawal to someone else - the wrong person?! It's absolutely vital that the teller can recognise you as the one who made the withdrawal, so that you can get the money (or resource) that you asked for.

Solution:

When you first appear to the teller, he or she tells you something in secret:

"When ever you are talking to me," says the teller, "you should first identify yourlself as GNASHEU329 - that way I know it's you".

Nobody else knows the secret passcode.

Example of How I Withdrew Cash:

So I decide to go to and chill out for 20 minutes and then later i go to the teller and say "I'd like to collect my withdrawal"

The teller asks me: "who are you??!"

"It's me, Mr George Banks!"

"Prove it!"

And then I tell them my passcode: GNASHEU329

"Certainly Mr Banks!"

That basically is how a session works. It allows one to be uniquely identified in a sea of millions of people. You need to identify yourself every time you deal with the teller.

If you got any questions or are unclear - please post comment and i will try to clear it up for you. The following is not strictly speaking, completely accurate in its terminology, but I hope it's helpful to you in understanding concepts.

Explanation via Pictures:

Sessions explained via Picture

How to make phpstorm display line numbers by default?

In PHPStorm 2016: File > Settings > Editor > General > Appearance > check "Show line numbers"

How to check Oracle patches are installed?

Here is an article on how to check and or install new patches :


To find the OPatch tool setup your database enviroment variables and then issue this comand:

cd $ORACLE_HOME/OPatch 
> pwd
/oracle/app/product/10.2.0/db_1/OPatch

To list all the patches applies to your database use the lsinventory option:

[oracle@DCG023 8828328]$ opatch lsinventory
Oracle Interim Patch Installer version 11.2.0.3.4
Copyright (c) 2012, Oracle Corporation. All rights reserved.

Oracle Home : /u00/product/11.2.0/dbhome_1
Central Inventory : /u00/oraInventory
from : /u00/product/11.2.0/dbhome_1/oraInst.loc
OPatch version : 11.2.0.3.4
OUI version : 11.2.0.1.0
Log file location : /u00/product/11.2.0/dbhome_1/cfgtoollogs/opatch/opatch2013-11-13_13-55-22PM_1.log
Lsinventory Output file location : /u00/product/11.2.0/dbhome_1/cfgtoollogs/opatch/lsinv/lsinventory2013-11-13_13-55-22PM.txt


Installed Top-level Products (1):
Oracle Database 11g 11.2.0.1.0
There are 1 products installed in this Oracle Home.

Interim patches (1) :
Patch 8405205 : applied on Mon Aug 19 15:18:04 BRT 2013
Unique Patch ID: 11805160
Created on 23 Sep 2009, 02:41:32 hrs PST8PDT
Bugs fixed:
8405205

OPatch succeeded.

To list the patches using sql :

select * from registry$history;

Naming returned columns in Pandas aggregate function?

For pandas >= 0.25

The functionality to name returned aggregate columns has been reintroduced in the master branch and is targeted for pandas 0.25. The new syntax is .agg(new_col_name=('col_name', 'agg_func'). Detailed example from the PR linked above:

In [2]: df = pd.DataFrame({'kind': ['cat', 'dog', 'cat', 'dog'],
   ...:                    'height': [9.1, 6.0, 9.5, 34.0],
   ...:                    'weight': [7.9, 7.5, 9.9, 198.0]})
   ...:

In [3]: df
Out[3]:
  kind  height  weight
0  cat     9.1     7.9
1  dog     6.0     7.5
2  cat     9.5     9.9
3  dog    34.0   198.0

In [4]: df.groupby('kind').agg(min_height=('height', 'min'), 
                               max_weight=('weight', 'max'))
Out[4]:
      min_height  max_weight
kind
cat          9.1         9.9
dog          6.0       198.0

It will also be possible to use multiple lambda expressions with this syntax and the two-step rename syntax I suggested earlier (below) as per this PR. Again, copying from the example in the PR:

In [2]: df = pd.DataFrame({"A": ['a', 'a'], 'B': [1, 2], 'C': [3, 4]})

In [3]: df.groupby("A").agg({'B': [lambda x: 0, lambda x: 1]})
Out[3]:
         B
  <lambda> <lambda 1>
A
a        0          1

and then .rename(), or in one go:

In [4]: df.groupby("A").agg(b=('B', lambda x: 0), c=('B', lambda x: 1))
Out[4]:
   b  c
A
a  0  0

For pandas < 0.25

The currently accepted answer by unutbu describes are great way of doing this in pandas versions <= 0.20. However, as of pandas 0.20, using this method raises a warning indicating that the syntax will not be available in future versions of pandas.

Series:

FutureWarning: using a dict on a Series for aggregation is deprecated and will be removed in a future version

DataFrames:

FutureWarning: using a dict with renaming is deprecated and will be removed in a future version

According to the pandas 0.20 changelog, the recommended way of renaming columns while aggregating is as follows.

# Create a sample data frame
df = pd.DataFrame({'A': [1, 1, 1, 2, 2],
                   'B': range(5),
                   'C': range(5)})

# ==== SINGLE COLUMN (SERIES) ====
# Syntax soon to be deprecated
df.groupby('A').B.agg({'foo': 'count'})
# Recommended replacement syntax
df.groupby('A').B.agg(['count']).rename(columns={'count': 'foo'})

# ==== MULTI COLUMN ====
# Syntax soon to be deprecated
df.groupby('A').agg({'B': {'foo': 'sum'}, 'C': {'bar': 'min'}})
# Recommended replacement syntax
df.groupby('A').agg({'B': 'sum', 'C': 'min'}).rename(columns={'B': 'foo', 'C': 'bar'})
# As the recommended syntax is more verbose, parentheses can
# be used to introduce line breaks and increase readability
(df.groupby('A')
    .agg({'B': 'sum', 'C': 'min'})
    .rename(columns={'B': 'foo', 'C': 'bar'})
)

Please see the 0.20 changelog for additional details.

Update 2017-01-03 in response to @JunkMechanic's comment.

With the old style dictionary syntax, it was possible to pass multiple lambda functions to .agg, since these would be renamed with the key in the passed dictionary:

>>> df.groupby('A').agg({'B': {'min': lambda x: x.min(), 'max': lambda x: x.max()}})

    B    
  max min
A        
1   2   0
2   4   3

Multiple functions can also be passed to a single column as a list:

>>> df.groupby('A').agg({'B': [np.min, np.max]})

     B     
  amin amax
A          
1    0    2
2    3    4

However, this does not work with lambda functions, since they are anonymous and all return <lambda>, which causes a name collision:

>>> df.groupby('A').agg({'B': [lambda x: x.min(), lambda x: x.max]})
SpecificationError: Function names must be unique, found multiple named <lambda>

To avoid the SpecificationError, named functions can be defined a priori instead of using lambda. Suitable function names also avoid calling .rename on the data frame afterwards. These functions can be passed with the same list syntax as above:

>>> def my_min(x):
>>>     return x.min()

>>> def my_max(x):
>>>     return x.max()

>>> df.groupby('A').agg({'B': [my_min, my_max]})

       B       
  my_min my_max
A              
1      0      2
2      3      4

Change input value onclick button - pure javascript or jQuery

Another simple solution for this case using jQuery. Keep in mind it's not a good practice to use inline javascript.

JsFiddle

I've added IDs to html on the total price and on the buttons. Here is the jQuery.

$('#two').click(function(){
    $('#count').val('2');
    $('#total').text('Product price: $1000');
});

$('#four').click(function(){
    $('#count').val('4');
    $('#total').text('Product price: $2000');
});

Adding an onclick event to a table row

Here is a compact and a bit cleaner version of the same pure Javascript (not a jQuery) solution as discussed above by @redsquare and @SolutionYogi (re: adding onclick event handlers to all HTML table rows) that works in all major Web Browsers, including the latest IE11:

function addRowHandlers() {
    var rows = document.getElementById("tableId").rows;
    for (i = 0; i < rows.length; i++) {
        rows[i].onclick = function(){ return function(){
               var id = this.cells[0].innerHTML;
               alert("id:" + id);
        };}(rows[i]);
    }
}
window.onload = addRowHandlers();

Working DEMO

Note: in order to make it work in IE8 as well, instead of this pointer use the explicit identifier like function(myrow) as suggested by @redsquare. Best regards,

How to parse a month name (string) to an integer for comparison in C#?

You can use the DateTime.Parse method to get a DateTime object and then check its Month property. Do something like this:

int month = DateTime.Parse("1." + monthName + " 2008").Month;

The trick is to build a valid date to create a DateTime object.

How do I parse JSON from a Java HTTPResponse?

Jackson appears to support some amount of JSON parsing straight from an InputStream. My understanding is that it runs on Android and is fairly quick. On the other hand, it is an extra JAR to include with your app, increasing download and on-flash size.

Sending message through WhatsApp

The following code is used by Google Now App and will NOT work for any other application.

I'm writing this post because it makes me angry, that WhatsApp does not allow any other developers to send messages directly except for Google.

And I want other freelance-developers to know, that this kind of cooperation is going on, while Google keeps talking about "open for anybody" and WhatsApp says they don't want to provide any access to developers.

Recently WhatsApp has added an Intent specially for Google Now, which should look like following:

Intent intent = new Intent("com.google.android.voicesearch.SEND_MESSAGE_TO_CONTACTS");
intent.setPackage("com.whatsapp");
intent.setComponent(new ComponentName("com.whatsapp", "com.whatsapp.VoiceMessagingActivity"));

intent.putExtra("com.google.android.voicesearch.extra.RECIPIENT_CONTACT_CHAT_ID", number);
intent.putExtra("android.intent.extra.TEXT", text);
intent.putExtra("search_action_token", ?????);

I could also find out that "search_action_token" is a PendingIntent that contains an IBinder-Object, which is sent back to Google App and checked, if it was created by Google Now.

Otherwise WhatsApp will not accept the message.

How to make a great R reproducible example

You can do this using reprex.

As mt1022 noted, "... good package for producing minimal, reproducible example is "reprex" from tidyverse".

According to Tidyverse:

The goal of "reprex" is to package your problematic code in such a way that other people can run it and feel your pain.

An example is given on tidyverse web site.

library(reprex)
y <- 1:4
mean(y)
reprex() 

I think this is the simplest way to create a reproducible example.

iOS - Build fails with CocoaPods cannot find header files

Have a try to comment this line for your target

#  use_frameworks!

Or you can refer to my another answer added unit testing target to xcode - failed to import bridging header won't go away

Difference between Date(dateString) and new Date(dateString)

The difference is the fact (if I recall from the ECMA documentation) is that Date("xx") does not create (in a sense) a new date object (in fact it is equivalent to calling (new Date("xx").toString()). While new Date("xx") will actually create a new date object.

For More Information:

Look at 15.9.2 of http://www.ecma-international.org/publications/files/ECMA-ST/ECMA-262.pdf

error: pathspec 'test-branch' did not match any file(s) known to git

You can also get this error with any version of git if the remote branch was created after your last clone/fetch and your local repo doesn't know about it yet. I solved it by doing a git fetch first which "tells" your local repo about all the remote branches.

git fetch
git checkout test-branch

SQL Query for Logins

@allain, @GateKiller your query selects users not logins
To select logins you can use this query:

SELECT name FROM master..sysxlogins WHERE sid IS NOT NULL

In MSSQL2005/2008 syslogins table is used insted of sysxlogins

Delete last commit in bitbucket

By now, cloud bitbucket (I'm not sure which version) allows to revert a commit from the file system as follows (I do not see how to revert from the Bitbucket interface in the Chrome browser).

-backup your entire directory to secure the changes you inadvertently committed

-select checked out directory

-right mouse button: tortoise git menu

-repo-browser (the menu option 'revert' only undoes the uncommited changes)

-press the HEAD button

-select the uppermost line (the last commit)

-right mouse button: revert change by this commit

-after it undid the changes on the file system, press commit

-this updates GIT with a message 'Revert (your previous message). This reverts commit so-and-so'

-select 'commit and push'.

Numpy where function multiple conditions

Try:

np.intersect1d(np.where(dists >= r)[0],np.where(dists <= r + dr)[0])

What does "<html xmlns="http://www.w3.org/1999/xhtml">" do?

You're mixing up HTML with XHTML.

Usually a <!DOCTYPE> declaration is used to distinguish between versions of HTMLish languages (in this case, HTML or XHTML).

Different markup languages will behave differently. My favorite example is height:100%. Look at the following in a browser:

XHTML

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
  <style type="text/css">
    table { height:100%;background:yellow; }
  </style>
</head>
<body>
  <table>
    <tbody>
      <tr><td>How tall is this?</td></tr>
    </tbody>
  </table>
</body>
</html>

... and compare it to the following: (note the conspicuous lack of a <!DOCTYPE> declaration)

HTML (quirks mode)

<html>
<head>
  <style type="text/css">
    table { height:100%;background:yellow; }
  </style>
</head>
<body>
  <table>
    <tbody>
      <tr><td>How tall is this?</td></tr>
    </tbody>
  </table>
</body>
</html>

You'll notice that the height of the table is drastically different, and the only difference between the 2 documents is the type of markup!

That's nice... now, what does <html xmlns="http://www.w3.org/1999/xhtml"> do?

That doesn't answer your question though. Technically, the xmlns attribute is used by the root element of an XHTML document: (according to Wikipedia)

The root element of an XHTML document must be html, and must contain an xmlns attribute to associate it with the XHTML namespace.

You see, it's important to understand that XHTML isn't HTML but XML - a very different creature. (ok, a kind of different creature) The xmlns attribute is just one of those things the document needs to be valid XML. Why? Because someone working on the standard said so ;) (you can read more about XML namespaces on Wikipedia but I'm omitting that info 'cause it's not actually relevant to your question!)

But then why is <html xmlns="http://www.w3.org/1999/xhtml"> fixing the CSS?

If structuring your document like so... (as you suggest in your comment)

<html xmlns="http://www.w3.org/1999/xhtml">
<!DOCTYPE html>
<html>
<head>
[...]

... is fixing your document, it leads me to believe that you don't know that much about CSS and HTML (no offense!) and that the truth is that without <html xmlns="http://www.w3.org/1999/xhtml"> it's behaving normally and with <html xmlns="http://www.w3.org/1999/xhtml"> it's not - and you just think it is, because you're used to writing invalid HTML and thus working in quirks mode.

The above example I provided is an example of that same problem; most people think height:100% should result in the height of the <table> being the whole window, and that the DOCTYPE is actually breaking their CSS... but that's not really the case; rather, they just don't understand that they need to add a html, body { height:100%; } CSS rule to achieve their desired effect.

How to obtain Certificate Signing Request

Follow these steps to create CSR (Code Signing Identity):

  1. On your Mac, go to the folder 'Applications' ? 'Utilities' and open 'Keychain Access.'

    enter image description here

  2. Go to 'Keychain Access' ? Certificate Assistant ? Request a Certificate from a Certificate Authority. ?

    enter image description here

  3. Fill out the information in the Certificate Information window as specified below and click "Continue."
    • In the User Email Address field, enter the email address to identify with this certificate
    • In the Common Name field, enter your name
    • In the Request group, click the "Saved to disk" option ?

    enter image description here

  4. Save the file to your hard drive.

    enter image description here


Use this CSR (.certSigningRequest) file to create project/application certificates and profiles, in Apple developer account.

How to build and run Maven projects after importing into Eclipse IDE

answer 1

  1. Right click on your project in eclipse
  2. go to maven -> Update Project

answer 2

simply press Alt+F5 after updating your pom.xml. This will build your project again and download all jar files

Jenkins - how to build a specific branch

This is extension of answer provided by Ranjith

I would suggest, you to choose a choice-parameter build, and specify the branches that you would like to build. Active Choice Parameter

And after that, you can specify branches to build. Branch to Build

Now, when you would build your project, you would be provided with "Build with Parameters, where you can choose the branch to build"

You can also write a groovy script to fetch all your branches to in active choice parameter.

how to filter out a null value from spark dataframe

I use the following code to solve my question. It works. But as we all know, I work around a country's mile to solve it. So, is there a short cut for that? Thanks

def filter_null(field : Any) : Int = field match {
    case null => 0
    case _    => 1
}

val test = train_event_join.join(
    user_friends_pair,
    train_event_join("user_id") === user_friends_pair("user_id") &&
    train_event_join("event_owner") === user_friends_pair("friend_id"),
    "left"
).select(
    train_event_join("user_id"),
    train_event_join("event_id"),
    train_event_join("invited"),
    train_event_join("day_diff"),
    train_event_join("interested"),
    train_event_join("event_owner"),
    user_friends_pair("friend_id")
).rdd.map{
    line => (
        line(0).toString.toLong,
        line(1).toString.toLong,
        line(2).toString.toLong,
        line(3).toString.toLong,
        line(4).toString.toLong,
        line(5).toString.toLong,
        filter_null(line(6))
        )
    }.toDF("user_id", "event_id", "invited", "day_diff", "interested", "event_owner", "creator_is_friend")

Accessing MVC's model property from Javascript

Contents of the Answer

1) How to access Model data in Javascript/Jquery code block in .cshtml file

2) How to access Model data in Javascript/Jquery code block in .js file

How to access Model data in Javascript/Jquery code block in .cshtml file

There are two types of c# variable (Model) assignments to JavaScript variable.

  1. Property assignment - Basic datatypes like int, string, DateTime (ex: Model.Name)
  2. Object assignment - Custom or inbuilt classes (ex: Model, Model.UserSettingsObj)

Lets look into the details of these two assignments.

For the rest of the answer lets consider the below AppUser Model as an example.

public class AppUser
{
    public string Name { get; set; }
    public bool IsAuthenticated { get; set; }
    public DateTime LoginDateTime { get; set; }
    public int Age { get; set; }
    public string UserIconHTML { get; set; }
}

And the values we assign this Model are

AppUser appUser = new AppUser
{
    Name = "Raj",
    IsAuthenticated = true,
    LoginDateTime = DateTime.Now,
    Age = 26,
    UserIconHTML = "<i class='fa fa-users'></i>"
};

Property assignment

Lets use different syntax for assignment and observe the results.

1) Without wrapping property assignment in quotes.

var Name = @Model.Name;  
var Age = @Model.Age;
var LoginTime = @Model.LoginDateTime; 
var IsAuthenticated = @Model.IsAuthenticated;   
var IconHtml = @Model.UserIconHTML;  

enter image description here

As you can see there are couple of errors, Raj and True is considered to be javascript variables and since they dont exist its an variable undefined error. Where as for the dateTime varialble the error is unexpected number numbers cannot have special characters, The HTML tags are converted into its entity names so that the browser doesn't mix up your values and the HTML markup.

2) Wrapping property assignment in Quotes.

var Name = '@Model.Name';
var Age = '@Model.Age';
var LoginTime = '@Model.LoginDateTime';
var IsAuthenticated = '@Model.IsAuthenticated';
var IconHtml = '@Model.UserIconHTML'; 

enter image description here

The results are valid, So wrapping the property assignment in quotes gives us valid syntax. But note that the Number Age is now a string, So if you dont want that we can just remove the quotes and it will be rendered as a number type.

3) Using @Html.Raw but without wrapping it in quotes

 var Name = @Html.Raw(Model.Name);
 var Age = @Html.Raw(Model.Age);
 var LoginTime = @Html.Raw(Model.LoginDateTime);
 var IsAuthenticated = @Html.Raw(Model.IsAuthenticated);
 var IconHtml = @Html.Raw(Model.UserIconHTML);

enter image description here

The results are similar to our test case 1. However using @Html.Raw()on the HTML string did show us some change. The HTML is retained without changing to its entity names.

From the docs Html.Raw()

Wraps HTML markup in an HtmlString instance so that it is interpreted as HTML markup.

But still we have errors in other lines.

4) Using @Html.Raw and also wrapping it within quotes

var Name ='@Html.Raw(Model.Name)';
var Age = '@Html.Raw(Model.Age)';
var LoginTime = '@Html.Raw(Model.LoginDateTime)';
var IsAuthenticated = '@Html.Raw(Model.IsAuthenticated)';
var IconHtml = '@Html.Raw(Model.UserIconHTML)';

enter image description here

The results are good with all types. But our HTML data is now broken and this will break the scripts. The issue is because we are using single quotes ' to wrap the the data and even the data has single quotes.

We can overcome this issue with 2 approaches.

1) use double quotes " " to wrap the HTML part. As the inner data has only single quotes. (Be sure that after wrapping with double quotes there are no " within the data too)

  var IconHtml = "@Html.Raw(Model.UserIconHTML)";

2) Escape the character meaning in your server side code. Like

  UserIconHTML = "<i class=\"fa fa-users\"></i>"

Conclusion of property assignment

  • Use quotes for non numeric dataType.
  • Do Not use quotes for numeric dataType.
  • Use Html.Raw to interpret your HTML data as is.
  • Take care of your HTML data to either escape the quotes meaning in server side, Or use a different quote than in data during assignment to javascript variable.

Object assignment

Lets use different syntax for assignment and observe the results.

1) Without wrapping object assignment in quotes.

  var userObj = @Model; 

enter image description here

When you assign a c# object to javascript variable the value of the .ToString() of that oject will be assigned. Hence the above result.

2 Wrapping object assignment in quotes

var userObj = '@Model'; 

enter image description here

3) Using Html.Raw without quotes.

   var userObj = @Html.Raw(Model); 

enter image description here

4) Using Html.Raw along with quotes

   var userObj = '@Html.Raw(Model)'; 

enter image description here

The Html.Raw was of no much use for us while assigning a object to variable.

5) Using Json.Encode() without quotes

var userObj = @Json.Encode(Model); 

//result is like
var userObj = {&quot;Name&quot;:&quot;Raj&quot;,
               &quot;IsAuthenticated&quot;:true,
               &quot;LoginDateTime&quot;:&quot;\/Date(1482572875150)\/&quot;,
               &quot;Age&quot;:26,
               &quot;UserIconHTML&quot;:&quot;\u003ci class=\&quot;fa fa-users\&quot;\u003e\u003c/i\u003e&quot;
              };

We do see some change, We see our Model is being interpreted as a object. But we have those special characters changed into entity names. Also wrapping the above syntax in quotes is of no much use. We simply get the same result within quotes.

From the docs of Json.Encode()

Converts a data object to a string that is in the JavaScript Object Notation (JSON) format.

As you have already encountered this entity Name issue with property assignment and if you remember we overcame it with the use of Html.Raw. So lets try that out. Lets combine Html.Raw and Json.Encode

6) Using Html.Raw and Json.Encode without quotes.

var userObj = @Html.Raw(Json.Encode(Model));

Result is a valid Javascript Object

 var userObj = {"Name":"Raj",
     "IsAuthenticated":true,
     "LoginDateTime":"\/Date(1482573224421)\/",
     "Age":26,
     "UserIconHTML":"\u003ci class=\"fa fa-users\"\u003e\u003c/i\u003e"
 };

enter image description here

7) Using Html.Raw and Json.Encode within quotes.

var userObj = '@Html.Raw(Json.Encode(Model))';

enter image description here

As you see wrapping with quotes gives us a JSON data

Conslusion on Object assignment

  • Use Html.Raw and Json.Encode in combintaion to assign your object to javascript variable as JavaScript object.
  • Use Html.Raw and Json.Encode also wrap it within quotes to get a JSON

Note: If you have observed the DataTime data format is not right. This is because as said earlier Converts a data object to a string that is in the JavaScript Object Notation (JSON) format and JSON does not contain a date type. Other options to fix this is to add another line of code to handle this type alone using javascipt Date() object

var userObj.LoginDateTime = new Date('@Html.Raw(Model.LoginDateTime)'); 
//without Json.Encode


How to access Model data in Javascript/Jquery code block in .js file

Razor syntax has no meaning in .js file and hence we cannot directly use our Model insisde a .js file. However there is a workaround.

1) Solution is using javascript Global variables.

We have to assign the value to a global scoped javascipt variable and then use this variable within all code block of your .cshtml and .js files. So the syntax would be

<script type="text/javascript">
  var userObj = @Html.Raw(Json.Encode(Model)); //For javascript object
  var userJsonObj = '@Html.Raw(Json.Encode(Model))'; //For json data
</script>

With this in place we can use the variables userObj and userJsonObj as and when needed.

Note: I personally dont suggest using global variables as it gets very hard for maintainance. However if you have no other option then you can use it with having a proper naming convention .. something like userAppDetails_global.

2) Using function() or closure Wrap all the code that is dependent on the model data in a function. And then execute this function from the .cshtml file .

external.js

 function userDataDependent(userObj){
  //.... related code
 }

.cshtml file

 <script type="text/javascript">
  userDataDependent(@Html.Raw(Json.Encode(Model))); //execute the function     
</script>

Note: Your external file must be referenced prior to the above script. Else the userDataDependent function is undefined.

Also note that the function must be in global scope too. So either solution we have to deal with global scoped players.

Default port for SQL Server

If you have access to the server then you can use

select local_tcp_port from sys.dm_exec_connections where local_tcp_port is not null

For full details see port number of SQL Server

How can I pass parameters to a partial view in mvc 4

One of The Shortest method i found for single value while i was searching for myself, is just passing single string and setting string as model in view like this.

In your Partial calling side

@Html.Partial("ParitalAction", "String data to pass to partial")

And then binding the model with Partial View like this

@model string

and the using its value in Partial View like this

@Model

You can also play with other datatypes like array, int or more complex data types like IDictionary or something else.

Hope it helps,

Seeing the console's output in Visual Studio 2010?

Press Ctrl + F5 to run the program instead of F5.

Elegant way to check for missing packages and install them?

Dason K. and I have the pacman package that can do this nicely. The function p_load in the package does this. The first line is just to ensure that pacman is installed.

if (!require("pacman")) install.packages("pacman")
pacman::p_load(package1, package2, package_n)

In bootstrap how to add borders to rows without adding up?

You can simply use the border class from bootstrap:

<div class="row border border-dark">
...
</div>

For more details visit the following link: Borders

Combining (concatenating) date and time into a datetime

I am using SQL Server 2016 and both myDate and myTime fields are strings. The below tsql statement worked in concatenating them into datetime

select cast((myDate + ' ' + myTime) as datetime) from myTable

In log4j, does checking isDebugEnabled before logging improve performance?

As of 2.x, Apache Log4j has this check built in, so having isDebugEnabled() isn't necessary anymore. Just do a debug() and the messages will be suppressed if not enabled.

android: how to align image in the horizontal center of an imageview?

Try:

android:layout_height="wrap_content"
android:scaleType="fitStart"

on the image in the RelativeLayout

How to set component default props on React component

For a function type prop you can use the following code:

AddAddressComponent.defaultProps = {
    callBackHandler: () => {}
};

AddAddressComponent.propTypes = {
    callBackHandler: PropTypes.func,
};

JQuery: dynamic height() with window resize()

To see the window height while (or after) it is resized, try it:

$(window).resize(function() {
$('body').prepend('<div>' + $(window).height() - 46 + '</div>');
});

jQuery same click event for multiple elements

Simply use $('.myclass1, .myclass2, .myclass3') for multiple selectors. Also, you dont need lambda functions to bind an existing function to the click event.

Assert an object is a specific type

Solution for JUnit 5

The documentation says:

However, JUnit Jupiter’s org.junit.jupiter.Assertions class does not provide an assertThat() method like the one found in JUnit 4’s org.junit.Assert class which accepts a Hamcrest Matcher. Instead, developers are encouraged to use the built-in support for matchers provided by third-party assertion libraries.

Example for Hamcrest:

import static org.hamcrest.CoreMatchers.instanceOf;
import static org.hamcrest.MatcherAssert.assertThat;

import org.junit.jupiter.api.Test;

class HamcrestAssertionDemo {

    @Test
    void assertWithHamcrestMatcher() {
        SubClass subClass = new SubClass();
        assertThat(subClass, instanceOf(BaseClass.class));
    }

}

Example for AssertJ:

import static org.assertj.core.api.Assertions.assertThat;

import org.junit.jupiter.api.Test;

class AssertJDemo {

    @Test
    void assertWithAssertJ() {
        SubClass subClass = new SubClass();
        assertThat(subClass).isInstanceOf(BaseClass.class);
    }

}

Note that this assumes you want to test behaviors similar to instanceof (which accepts subclasses). If you want exact equal type, I don’t see a better way than asserting the two class to be equal like you mentioned in the question.

How to code a modulo (%) operator in C/C++/Obj-C that handles negative numbers

Example template for C++

template< class T >
T mod( T a, T b )
{
    T const r = a%b;
    return ((r!=0)&&((r^b)<0) ? r + b : r);
}

With this template, the returned remainder will be zero or have the same sign as the divisor (denominator) (the equivalent of rounding towards negative infinity), instead of the C++ behavior of the remainder being zero or having the same sign as the dividend (numerator) (the equivalent of rounding towards zero).

Email Address Validation for ASP.NET

Preventing XSS is a different issue from validating input.

Regarding XSS: You should not try to check input for XSS or related exploits. You should prevent XSS exploits, SQL injection and so on by escaping correctly when inserting strings into a different language where some characters are "magic", eg, when inserting strings in HTML or SQL. For example a name like O'Reilly is perfectly valid input, but could cause a crash or worse if inserted unescaped into SQL. You cannot prevent that kind of problems by validating input.

Validation of user input makes sense to prevent missing or malformed data, eg. a user writing "asdf" in the zip-code field and so on. Wrt. e-mail adresses, the syntax is so complex though, that it doesnt provide much benefit to validate it using a regex. Just check that it contains a "@".

Process all arguments except the first one (in a bash script)

If you want a solution that also works in /bin/sh try

first_arg="$1"
shift
echo First argument: "$first_arg"
echo Remaining arguments: "$@"

shift [n] shifts the positional parameters n times. A shift sets the value of $1 to the value of $2, the value of $2 to the value of $3, and so on, decreasing the value of $# by one.

Sum of values in an array using jQuery

You can do it in this way.

var somearray = ["20","40","80","400"];

somearray = somearray.map(Number);

var total = somearray.reduce(function(a,b){  return a+b },0)

console.log(total);

Get program execution time in the shell

You can get much more detailed information than the bash built-in time (which Robert Gamble mentions) using time(1). Normally this is /usr/bin/time.

Editor's note: To ensure that you're invoking the external utility time rather than your shell's time keyword, invoke it as /usr/bin/time.
time is a POSIX-mandated utility, but the only option it is required to support is -p.
Specific platforms implement specific, nonstandard extensions: -v works with GNU's time utility, as demonstrated below (the question is tagged ); the BSD/macOS implementation uses -l to produce similar output - see man 1 time.

Example of verbose output:

$ /usr/bin/time -v sleep 1
       Command being timed: "sleep 1"
       User time (seconds): 0.00
       System time (seconds): 0.00
       Percent of CPU this job got: 1%
       Elapsed (wall clock) time (h:mm:ss or m:ss): 0:01.05
       Average shared text size (kbytes): 0
       Average unshared data size (kbytes): 0
       Average stack size (kbytes): 0
       Average total size (kbytes): 0
       Maximum resident set size (kbytes): 0
       Average resident set size (kbytes): 0
       Major (requiring I/O) page faults: 0
       Minor (reclaiming a frame) page faults: 210
       Voluntary context switches: 2
       Involuntary context switches: 1
       Swaps: 0
       File system inputs: 0
       File system outputs: 0
       Socket messages sent: 0
       Socket messages received: 0
       Signals delivered: 0
       Page size (bytes): 4096
       Exit status: 0

Viewing unpushed Git commits

If you have git submodules...

Whether you do git cherry -v or git logs @{u}.. -p, don't forget to include your submodules via git submodule foreach --recursive 'git logs @{u}..'.

I am using the following bash script to check all of that:

    unpushedCommitsCmd="git log @{u}.."; # Source: https://stackoverflow.com/a/8182309

    # check if there are unpushed changes
    if [ -n "$($getGitUnpushedCommits)" ]; then # Check Source: https://stackoverflow.com/a/12137501
        echo "You have unpushed changes.  Push them first!"
        $getGitUnpushedCommits;
        exit 2
    fi

    unpushedInSubmodules="git submodule foreach --recursive --quiet ${unpushedCommitsCmd}"; # Source: https://stackoverflow.com/a/24548122
    # check if there are unpushed changes in submodules
    if [ -n "$($unpushedInSubmodules)" ]; then
        echo "You have unpushed changes in submodules.  Push them first!"
        git submodule foreach --recursive ${unpushedCommitsCmd} # not "--quiet" this time, to display details
        exit 2
    fi

Assets file project.assets.json not found. Run a NuGet package restore

In my case the error was the GIT repository. It had spaces in the name, making my project unable to restore

If this is your issue, just rename the GIT repository when you clone

git clone http://Your%20Project%20With%20Spaces newprojectname

Input type for HTML form for integer

<input type="number" step="1" ...

By adding the step attribute, you restrict input to integers.

Of course you should always validate on the server as well. Except under carefully controlled conditions, everything received from a client needs to be treated as suspect.

Error: Specified cast is not valid. (SqlManagerUI)

Sometimes it happens because of the version change like store 2012 db on 2008, so how to check it?

RESTORE VERIFYONLY FROM DISK = N'd:\yourbackup.bak'

if it gives error like:

Msg 3241, Level 16, State 13, Line 2 The media family on device 'd:\alibaba.bak' is incorrectly formed. SQL Server cannot process this media family. Msg 3013, Level 16, State 1, Line 2 VERIFY DATABASE is terminating abnormally.

Check it further:

RESTORE HEADERONLY FROM DISK = N'd:\yourbackup.bak'

BackupName is "* INCOMPLETE *", Position is "1", other fields are "NULL".

Means either your backup is corrupt or taken from newer version.

Eclipse IDE: How to zoom in on text?

On Mac you can do Press 'Command' and '+' buttons to zoom in. press 'Command' and '-' buttons to zoom out.

Where can I find a list of Mac virtual key codes?

In addition to the keycodes supplied in other answers, there are also "usage IDs" used for key remapping in the newer APIs introduced in macOS Sierra:

Technical Note TN2450

Remapping Keys in macOS 10.12 Sierra

Under macOS Sierra 10.12, the mechanism for key remapping was changed. This Technical Note is for developers of key remapping software so that they can update their software to support macOS Sierra 10.12. We present 2 solutions for implementing key remapping functionality for macOS 10.12 in this Technical Note.

https://developer.apple.com/library/archive/technotes/tn2450/_index.html

Keyboard a and A - 0x04
Keyboard b and B - 0x05
Keyboard c and C - 0x06
Keyboard d and D - 0x07
Keyboard e and E - 0x08
...

CSS filter: make color image with transparency white

You can use

filter: brightness(0) invert(1);

_x000D_
_x000D_
html {_x000D_
  background: red;_x000D_
}_x000D_
p {_x000D_
  float: left;_x000D_
  max-width: 50%;_x000D_
  text-align: center;_x000D_
}_x000D_
img {_x000D_
  display: block;_x000D_
  max-width: 100%;_x000D_
}_x000D_
.filter {_x000D_
  -webkit-filter: brightness(0) invert(1);_x000D_
  filter: brightness(0) invert(1);_x000D_
}
_x000D_
<p>_x000D_
  Original:_x000D_
  <img src="http://i.stack.imgur.com/jO8jP.gif" />_x000D_
</p>_x000D_
<p>_x000D_
  Filter:_x000D_
  <img src="http://i.stack.imgur.com/jO8jP.gif" class="filter" />_x000D_
</p>
_x000D_
_x000D_
_x000D_

First, brightness(0) makes all image black, except transparent parts, which remain transparent.

Then, invert(1) makes the black parts white.

How to prevent errno 32 broken pipe?

It depends on how you tested it, and possibly on differences in the TCP stack implementation of the personal computer and the server.

For example, if your sendall always completes immediately (or very quickly) on the personal computer, the connection may simply never have broken during sending. This is very likely if your browser is running on the same machine (since there is no real network latency).


In general, you just need to handle the case where a client disconnects before you're finished, by handling the exception.

Remember that TCP communications are asynchronous, but this is much more obvious on physically remote connections than on local ones, so conditions like this can be hard to reproduce on a local workstation. Specifically, loopback connections on a single machine are often almost synchronous.

jQuery Ajax Request inside Ajax Request

Here is an example:

$.ajax({
        type: "post",
        url: "ajax/example.php",
        data: 'page=' + btn_page,
        success: function (data) {
            var a = data; // This line shows error.
            $.ajax({
                type: "post",
                url: "example.php",
                data: 'page=' + a,
                success: function (data) {

                }
            });
        }
    });

How to detect the currently pressed key?

if (Form.ModifierKeys == Keys.Shift)

does work for a text box if the above code is in the form's keydown event and no other control captures the keydown event for the key down.

Also one may wish stop further key processing with:

e.Handled = true;

Ubuntu says "bash: ./program Permission denied"

Try this:

sudo chmod +x program_name
./program_name 

Centering the image in Bootstrap

Update 2018

Bootstrap 2.x

You could create a new CSS class such as:

.img-center {margin:0 auto;}

And then, add this to each IMG:

 <img src="images/2.png" class="img-responsive img-center">

OR, just override the .img-responsive if you're going to center all images..

 .img-responsive {margin:0 auto;}

Demo: http://bootply.com/86123

Bootstrap 3.x

EDIT - With the release of Bootstrap 3.0.1, the center-block class can now be used without any additional CSS..

 <img src="images/2.png" class="img-responsive center-block">

Bootstrap 4

In Bootstrap 4, the mx-auto class (auto x-axis margins) can be used to center images that are display:block. However, img is display:inline by default so text-center can be used on the parent.

<div class="container">
    <div class="row">
        <div class="col-12">
            <img class="mx-auto d-block" src="//placehold.it/200">  
        </div>
    </div>
    <div class="row">
        <div class="col-12 text-center">
            <img src="//placehold.it/200">  
        </div>
    </div>
</div>

Bootsrap 4 - center image demo

Cannot serve WCF services in IIS on Windows 8

For Windows Server 2012, the solution is very similar to faester's (see above). From the Server Manager, click on Add roles and features, select the appropriate server, then select Features. Under .NET Framework 4.5 Features, you'll see WCF Services, and under that, you'll find HTTP Activation.

Calling the base class constructor from the derived class constructor

The constructor of PetStore will call a constructor of Farm; there's no way you can prevent it. If you do nothing (as you've done), it will call the default constructor (Farm()); if you need to pass arguments, you'll have to specify the base class in the initializer list:

PetStore::PetStore()
    : Farm( neededArgument )
    , idF( 0 )
{
}

(Similarly, the constructor of PetStore will call the constructor of nameF. The constructor of a class always calls the constructors of all of its base classes and all of its members.)

Is putting a div inside an anchor ever correct?

You can't put <div> inside <a> - it's not valid (X)HTML.

Even though you style a span with display: block you still can't put block-level elements inside it: the (X)HTML still has to obey the (X)HTML DTD (whichever one you use), no matter how the CSS alters things.

The browser will probably display it as you want, but that doesn't make it right.

UnsatisfiedDependencyException: Error creating bean with name

The application needs to be placed in the same directory as the scanned package:

enter image description here

How do you add swap to an EC2 instance?

After applying the steps mentioned by ajtrichards you can check if your amazon free tier instance is using swap using this command

cat /proc/meminfo

result:

ubuntu@ip-172-31-24-245:/$ cat /proc/meminfo
MemTotal:         604340 kB
MemFree:            8524 kB
Buffers:            3380 kB
Cached:           398316 kB
SwapCached:            0 kB
Active:           165476 kB
Inactive:         384556 kB
Active(anon):     141344 kB
Inactive(anon):     7248 kB
Active(file):      24132 kB
Inactive(file):   377308 kB
Unevictable:           0 kB
Mlocked:               0 kB

SwapTotal: 1048572 kB

SwapFree: 1048572 kB

Dirty:                 0 kB
Writeback:             0 kB
AnonPages:        148368 kB
Mapped:            14304 kB
Shmem:               256 kB
Slab:              26392 kB
SReclaimable:      18648 kB
SUnreclaim:         7744 kB
KernelStack:         736 kB
PageTables:         5060 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     1350740 kB
Committed_AS:     623908 kB
VmallocTotal:   34359738367 kB
VmallocUsed:        7420 kB
VmallocChunk:   34359728748 kB
HardwareCorrupted:     0 kB
AnonHugePages:         0 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:      637952 kB
DirectMap2M:           0 kB

Escaping quotes and double quotes

Escaping parameters like that is usually source of frustration and feels a lot like a time wasted. I see you're on v2 so I would suggest using a technique that Joel "Jaykul" Bennet blogged about a while ago.

Long story short: you just wrap your string with @' ... '@ :

Start-Process \\server\toto.exe @'
-batch=B -param="sort1;parmtxt='Security ID=1234'"
'@

(Mind that I assumed which quotes are needed, and which things you were attempting to escape.) If you want to work with the output, you may want to add the -NoNewWindow switch.

BTW: this was so important issue that since v3 you can use --% to stop the PowerShell parser from doing anything with your parameters:

\\server\toto.exe --% -batch=b -param="sort1;paramtxt='Security ID=1234'"

... should work fine there (with the same assumption).

php search array key and get value

array_search('20120504', array_keys($your_array));

Execute php file from another php

Sounds like you're trying to execute the PHP code directly in your shell. Your shell doesn't speak PHP, so it interprets your PHP code as though it's in your shell's native language, as though you had literally run <?php at the command line.

Shell scripts usually start with a "shebang" line that tells the shell what program to use to interpret the file. Begin your file like this:

#!/usr/bin/env php
<?php
//Connection
function connection () {

Besides that, the string you're passing to exec doesn't make any sense. It starts with a slash all by itself, it uses too many periods in the path, and it has a stray right parenthesis.

Copy the contents of the command string and paste them at your command line. If it doesn't run there, then exec probably won't be able to run it, either.

Another option is to change the command you execute. Instead of running the script directly, run php and pass your script as an argument. Then you shouldn't need the shebang line.

exec('php name.php');

How can I share Jupyter notebooks with non-programmers?

It depends on what you are intending to do with your Notebook: do you want that the user can recompute the results or just playing with them?

Static notebook

NBViewer is a great tool. You can directly use it inside Jupyter. Github has also a render, so you can directly link your file (such as https://github.com/my-name/my-repo/blob/master/mynotebook.ipynb)

Alive notebook

If you want your user to be able to recompute some parts, you can also use MyBinder. It takes some time to start your notebook, but the result is worth it.

As said by @Mapl, Google can host your notebook with Colab. A nice feature is to compute your cells over a GPU.

How to download PDF automatically using js?

Please try this

_x000D_
_x000D_
(function ($) {
    $(document).ready(function(){
       function validateEmail(email) {
            const re = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
            return re.test(email);
           }
       
       if($('.submitclass').length){
            $('.submitclass').click(function(){
                $email_id = $('.custom-email-field').val();
                if (validateEmail($email_id)) {
                  var url= $(this).attr('pdf_url');
                  var link = document.createElement('a');
                  link.href = url;
                  link.download = url.split("/").pop();
                  link.dispatchEvent(new MouseEvent('click'));
                }
            });
       }
    });
}(jQuery));
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form method="post">
        <div class="form-item form-type-textfield form-item-email-id form-group">
            <input placeholder="please enter email address" class="custom-email-field form-control" type="text" id="edit-email-id" name="email_id" value="" size="60" maxlength="128" required />
        </div>
        <button type="submit" class="submitclass btn btn-danger" pdf_url="https://file-examples-com.github.io/uploads/2017/10/file-sample_150kB.pdf">Submit</button>
</form>
_x000D_
_x000D_
_x000D_

Or use download attribute to tag in HTML5

Getting rid of all the rounded corners in Twitter Bootstrap

With SASS Bootstrap - if you are compiling Bootstrap yourself - you can set all border radius (or more specific) simply to zero:

$border-radius:               0;
$border-radius-lg:            0;
$border-radius-sm:            0;

Get first element in PHP stdObject

Update PHP 7.4

Curly brace access syntax is deprecated since PHP 7.4

Update 2019

Moving on to the best practices of OOPS, @MrTrick's answer must be marked as correct, although my answer provides a hacked solution its not the best method.

Simply iterate its using {}

Example:

$videos{0}->id

This way your object is not destroyed and you can easily iterate through object.

For PHP 5.6 and below use this

$videos{0}['id']

Both array() and the stdClass objects can be accessed using the current() key() next() prev() reset() end() functions.

So, if your object looks like

object(stdClass)#19 (3) {
  [0]=>
  object(stdClass)#20 (22) {
    ["id"]=>
    string(1) "123"
  etc...

Then you can just do;

$id = reset($obj)->id; //Gets the 'id' attr of the first entry in the object

If you need the key for some reason, you can do;

reset($obj); //Ensure that we're at the first element
$key = key($obj);

Hope that works for you. :-) No errors, even in super-strict mode, on PHP 5.4


2022 Update:
After PHP 7.4, using current(), end(), etc functions on objects is deprecated.

In newer versions of PHP, use the ArrayIterator class:

$objIterator = new ArrayIterator($obj);

$id = $objIterator->current()->id; // Gets the 'id' attr of the first entry in the object

$key = $objIterator->key(); // and gets the key

C++11 thread-safe queue

According to the standard condition_variables are allowed to wakeup spuriously, even if the event hasn't occured. In case of a spurious wakeup it will return cv_status::no_timeout (since it woke up instead of timing out), even though it hasn't been notified. The correct solution for this is of course to check if the wakeup was actually legit before proceding.

The details are specified in the standard §30.5.1 [thread.condition.condvar]:

—The function will unblock when signaled by a call to notify_one(), a call to notify_all(), expiration of the absolute timeout (30.2.4) speci?ed by abs_time, or spuriously.

...

Returns: cv_status::timeout if the absolute timeout (30.2.4) speci?edby abs_time expired, other-ise cv_status::no_timeout.

How to fix Git error: object file is empty?

git stash
git checkout master
cd .git/ && find . -type f -empty -delete
git branch your-branch-name -D
git checkout -b your-branch-name
git stash pop

resolve my problem

JSON.Net Self referencing loop detected

You must set Preserving Object References:

var jsonSerializerSettings = new JsonSerializerSettings
{
    PreserveReferencesHandling = PreserveReferencesHandling.Objects
};

Then call your query var q = (from a in db.Events where a.Active select a).ToList(); like

string jsonStr = Newtonsoft.Json.JsonConvert.SerializeObject(q, jsonSerializerSettings);

See: https://www.newtonsoft.com/json/help/html/PreserveObjectReferences.htm

What to gitignore from the .idea folder?

https://www.gitignore.io/api/jetbrains

Created by https://www.gitignore.io/api/jetbrains

### JetBrains ###
# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and Webstorm
# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839

# User-specific stuff:
.idea/workspace.xml
.idea/tasks.xml
.idea/dictionaries
.idea/vcs.xml
.idea/jsLibraryMappings.xml

# Sensitive or high-churn files:
.idea/dataSources.ids
.idea/dataSources.xml
.idea/dataSources.local.xml
.idea/sqlDataSources.xml
.idea/dynamic.xml
.idea/uiDesigner.xml

# Gradle:
.idea/gradle.xml
.idea/libraries

# Mongo Explorer plugin:
.idea/mongoSettings.xml

## File-based project format:
*.iws

## Plugin-specific files:

# IntelliJ
/out/

# mpeltonen/sbt-idea plugin
.idea_modules/

# JIRA plugin
atlassian-ide-plugin.xml

# Crashlytics plugin (for Android Studio and IntelliJ)
com_crashlytics_export_strings.xml
crashlytics.properties
crashlytics-build.properties
fabric.properties

### JetBrains Patch ###
# Comment Reason: https://github.com/joeblau/gitignore.io/issues/186#issuecomment-215987721

# *.iml
# modules.xml
# .idea/misc.xml 
# *.ipr 

How to get database structure in MySQL via query

SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA='bodb' AND TABLE_NAME='abc';

works for getting all column names

Finding last occurrence of substring in string, replacing that

A one liner would be :

str=str[::-1].replace(".",".-",1)[::-1]

First Or Create

firstOrCreate() checks for all the arguments to be present before it finds a match.

If you only want to check on a specific field, then use firstOrCreate(['field_name' => 'value']) like

$user = User::firstOrCreate([
    'email' => '[email protected]'
], [
    'firstName' => 'abcd',
    'lastName' => 'efgh',
    'veristyName'=>'xyz',
]);

Then it check only the email

setting textColor in TextView in layout/main.xml main layout file not referencing colors.xml file. (It wants a #RRGGBB instead of @color/text_color)

You should write textcolor in xml as

android:textColor="@color/text_color"

or

android:textColor="#FFFFFF"

iOS: present view controller programmatically

If you are using Storyboard and your "add" viewController is in storyboard then set an identifier for your "add" viewcontroller in settings so you can do something like this:

UIStoryboard* storyboard = [UIStoryboard storyboardWithName:@"NameOfYourStoryBoard" 
                                                     bundle:nil];
AddTaskViewController *add = 
           [storyboard instantiateViewControllerWithIdentifier:@"viewControllerIdentifier"];

[self presentViewController:add 
                   animated:YES 
                 completion:nil];

if you do not have your "add" viewController in storyboard or a nib file and want to create the whole thing programmaticaly then appDocs says:

If you cannot define your views in a storyboard or a nib file, override the loadView method to manually instantiate a view hierarchy and assign it to the view property.

How to plot a function curve in R

As sjdh also mentioned, ggplot2 comes to the rescue. A more intuitive way without making a dummy data set is to use xlim:

library(ggplot2)
eq <- function(x){sin(x)}
base <- ggplot() + xlim(0, 30)
base + geom_function(fun=eq)

Additionally, for a smoother graph we can set the number of points over which the graph is interpolated using n:

base + geom_function(fun=eq, n=10000)

In Python, how to display current time in readable format

Take a look at the facilities provided by the time module

You have several conversion functions there.

Edit: see the datetime module for more OOP-like solutions. The time library linked above is kinda imperative.

What is ":-!!" in C code?

It's creating a size 0 bitfield if the condition is false, but a size -1 (-!!1) bitfield if the condition is true/non-zero. In the former case, there is no error and the struct is initialized with an int member. In the latter case, there is a compile error (and no such thing as a size -1 bitfield is created, of course).

Difference between onCreate() and onStart()?

Take a look on life cycle of Activity enter image description here

Where

***onCreate()***

Called when the activity is first created. This is where you should do all of your normal static set up: create views, bind data to lists, etc. This method also provides you with a Bundle containing the activity's previously frozen state, if there was one. Always followed by onStart().

***onStart()***

Called when the activity is becoming visible to the user. Followed by onResume() if the activity comes to the foreground, or onStop() if it becomes hidden.

And you can write your simple class to take a look when these methods call

public class TestActivity extends Activity {
    /** Called when the activity is first created. */

    private final static String TAG = "TestActivity";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Log.i(TAG, "On Create .....");
    }
    /* (non-Javadoc)
    * @see android.app.Activity#onDestroy()
    */
    @Override
    protected void onDestroy() { 
        super.onDestroy();
        Log.i(TAG, "On Destroy .....");
    }
    /* (non-Javadoc)
    * @see android.app.Activity#onPause()
    */
    @Override
    protected void onPause() { 
        super.onPause();
        Log.i(TAG, "On Pause .....");
    }

    /* (non-Javadoc)
    * @see android.app.Activity#onRestart()
    */
    @Override
    protected void onRestart() {
        super.onRestart();
        Log.i(TAG, "On Restart .....");
    }

    /* (non-Javadoc)
    * @see android.app.Activity#onResume()
    */
    @Override
    protected void onResume() {
        super.onResume();
        Log.i(TAG, "On Resume .....");
    }

    /* (non-Javadoc)
    * @see android.app.Activity#onStart()
    */
    @Override
    protected void onStart() {
        super.onStart();
        Log.i(TAG, "On Start .....");
    }
    /* (non-Javadoc)
    * @see android.app.Activity#onStop()
    */
    @Override
    protected void onStop() {
        super.onStop();
        Log.i(TAG, "On Stop .....");
    }
}

Hope this will clear your confusion.

And take a look here for details.

Lifecycle Methods in Details is a very good example and demo application, which is a very good article to understand the life cycle.

How to push a new folder (containing other folders and files) to an existing git repo?

You can directly go to Web IDE and upload your folder there.

Steps:

  1. Go to Web IDE(Mostly located below the clone option).
  2. Create new directory at your path
  3. Upload your files and folders

In some cases you may not be able to directly upload entire folder containing folders, In such cases, you will have to create directory structure yourself.

Need to perform Wildcard (*,?, etc) search on a string using Regex

Windows and *nux treat wildcards differently. *, ? and . are processed in a very complex way by Windows, one's presence or position would change another's meaning. While *nux keeps it simple, all it does is just one simple pattern match. Besides that, Windows matches ? for 0 or 1 chars, Linux matches it for exactly 1 chars.

I didn't find authoritative documents on this matter, here is just my conclusion based on days of tests on Windows 8/XP (command line, dir command to be specific, and the Directory.GetFiles method uses the same rules too) and Ubuntu Server 12.04.1 (ls command). I made tens of common and uncommon cases work, although there'are many failed cases too.

The current answer by Gabe, works like *nux. If you also want a Windows style one, and are willing to accept the imperfection, then here it is:

    /// <summary>
    /// <para>Tests if a file name matches the given wildcard pattern, uses the same rule as shell commands.</para>
    /// </summary>
    /// <param name="fileName">The file name to test, without folder.</param>
    /// <param name="pattern">A wildcard pattern which can use char * to match any amount of characters; or char ? to match one character.</param>
    /// <param name="unixStyle">If true, use the *nix style wildcard rules; otherwise use windows style rules.</param>
    /// <returns>true if the file name matches the pattern, false otherwise.</returns>
    public static bool MatchesWildcard(this string fileName, string pattern, bool unixStyle)
    {
        if (fileName == null)
            throw new ArgumentNullException("fileName");

        if (pattern == null)
            throw new ArgumentNullException("pattern");

        if (unixStyle)
            return WildcardMatchesUnixStyle(pattern, fileName);

        return WildcardMatchesWindowsStyle(fileName, pattern);
    }

    private static bool WildcardMatchesWindowsStyle(string fileName, string pattern)
    {
        var dotdot = pattern.IndexOf("..", StringComparison.Ordinal);
        if (dotdot >= 0)
        {
            for (var i = dotdot; i < pattern.Length; i++)
                if (pattern[i] != '.')
                    return false;
        }

        var normalized = Regex.Replace(pattern, @"\.+$", "");
        var endsWithDot = normalized.Length != pattern.Length;

        var endWeight = 0;
        if (endsWithDot)
        {
            var lastNonWildcard = normalized.Length - 1;
            for (; lastNonWildcard >= 0; lastNonWildcard--)
            {
                var c = normalized[lastNonWildcard];
                if (c == '*')
                    endWeight += short.MaxValue;
                else if (c == '?')
                    endWeight += 1;
                else
                    break;
            }

            if (endWeight > 0)
                normalized = normalized.Substring(0, lastNonWildcard + 1);
        }

        var endsWithWildcardDot = endWeight > 0;
        var endsWithDotWildcardDot = endsWithWildcardDot && normalized.EndsWith(".");
        if (endsWithDotWildcardDot)
            normalized = normalized.Substring(0, normalized.Length - 1);

        normalized = Regex.Replace(normalized, @"(?!^)(\.\*)+$", @".*");

        var escaped = Regex.Escape(normalized);
        string head, tail;

        if (endsWithDotWildcardDot)
        {
            head = "^" + escaped;
            tail = @"(\.[^.]{0," + endWeight + "})?$";
        }
        else if (endsWithWildcardDot)
        {
            head = "^" + escaped;
            tail = "[^.]{0," + endWeight + "}$";
        }
        else
        {
            head = "^" + escaped;
            tail = "$";
        }

        if (head.EndsWith(@"\.\*") && head.Length > 5)
        {
            head = head.Substring(0, head.Length - 4);
            tail = @"(\..*)?" + tail;
        }

        var regex = head.Replace(@"\*", ".*").Replace(@"\?", "[^.]?") + tail;
        return Regex.IsMatch(fileName, regex, RegexOptions.IgnoreCase);
    }

    private static bool WildcardMatchesUnixStyle(string pattern, string text)
    {
        var regex = "^" + Regex.Escape(pattern)
                               .Replace("\\*", ".*")
                               .Replace("\\?", ".")
                    + "$";

        return Regex.IsMatch(text, regex);
    }

There's a funny thing, even the Windows API PathMatchSpec does not agree with FindFirstFile. Just try a1*., FindFirstFile says it matches a1, PathMatchSpec says not.

What is useState() in React?

useState is a Hook that allows you to have state variables in functional components.

There are two types of components in React: class and functional components.

Class components are ES6 classes that extend from React.Component and can have state and lifecycle methods:

class Message extends React.Component {
constructor(props) {
super(props);
this.state = {
  message: ‘’    
 };
}

componentDidMount() {
/* ... */
 }

render() {
return <div>{this.state.message}</div>;
  }
}

Functional components are functions that just accept arguments as the properties of the component and return valid JSX:

function Message(props) {
  return <div>{props.message}</div>
 }
// Or as an arrow function
const Message = (props) =>  <div>{props.message}</div>

As you can see, there are no state or lifecycle methods.

$(document).ready not Working

  • Check for your script has to be write or loaded after jQuery link.

_x000D_
_x000D_
<script type="text/javascript" src="js/jquery-3.2.1.min.js"></script>_x000D_
_x000D_
//after link >> write codes..._x000D_
_x000D_
<script>_x000D_
    $(document).ready(function(){_x000D_
      //your code_x000D_
    })(jQuery);_x000D_
</script>
_x000D_
_x000D_
_x000D_

SSIS Excel Connection Manager failed to Connect to the Source

It seems like the 32-bit version of Excel was not installed. Remember that SSDT is a 32-bit IDE. Therefore, when data is access from SSDT the 32-bit data providers are used. When running the package outside of SSDT it runs in 64-bit mode (not always, but mostly) and uses the 64-bit data providers.

Always keep in mind that if you want to run your package in 64-bit (which you should aim for) you will need both the 32-bit data providers (for development in SSDT) as well as the 64-bit data providers (for executing the package in production).

I downloaded the 32-bit access drivers from:

After installation, I could see the worksheets


Source:

How can one check to see if a remote file exists using PHP?

There's an even more sophisticated alternative. You can do the checking all client-side using a JQuery trick.

$('a[href^="http://"]').filter(function(){
     return this.hostname && this.hostname !== location.hostname;
}).each(function() {
    var link = jQuery(this);
    var faviconURL =
      link.attr('href').replace(/^(http:\/\/[^\/]+).*$/, '$1')+'/favicon.ico';
    var faviconIMG = jQuery('<img src="favicon.png" alt="" />')['appendTo'](link);
    var extImg = new Image();
    extImg.src = faviconURL;
    if (extImg.complete)
      faviconIMG.attr('src', faviconURL);
    else
      extImg.onload = function() { faviconIMG.attr('src', faviconURL); };
});

From http://snipplr.com/view/18782/add-a-favicon-near-external-links-with-jquery/ (the original blog is presently down)

Get free disk space

I had the same problem and i saw waruna manjula giving the best answer. However writing it all down on the console is not what you might want. To get string off al info use the following

Step one: declare values at begin

    //drive 1
    public static string drivename = "";
    public static string drivetype = "";
    public static string drivevolumelabel = "";
    public static string drivefilesystem = "";
    public static string driveuseravailablespace = "";
    public static string driveavailablespace = "";
    public static string drivetotalspace = "";

    //drive 2
    public static string drivename2 = "";
    public static string drivetype2 = "";
    public static string drivevolumelabel2 = "";
    public static string drivefilesystem2 = "";
    public static string driveuseravailablespace2 = "";
    public static string driveavailablespace2 = "";
    public static string drivetotalspace2 = "";

    //drive 3
    public static string drivename3 = "";
    public static string drivetype3 = "";
    public static string drivevolumelabel3 = "";
    public static string drivefilesystem3 = "";
    public static string driveuseravailablespace3 = "";
    public static string driveavailablespace3 = "";
    public static string drivetotalspace3 = "";

Step 2: actual code

                DriveInfo[] allDrives = DriveInfo.GetDrives();
                int drive = 1;
                foreach (DriveInfo d in allDrives)
                {
                    if (drive == 1)
                    {
                        drivename = String.Format("Drive {0}", d.Name);
                        drivetype = String.Format("Drive type: {0}", d.DriveType);
                        if (d.IsReady == true)
                        {
                            drivevolumelabel = String.Format("Volume label: {0}", d.VolumeLabel);
                            drivefilesystem = String.Format("File system: {0}", d.DriveFormat);
                            driveuseravailablespace = String.Format("Available space to current user:{0, 15} bytes", d.AvailableFreeSpace);
                            driveavailablespace = String.Format("Total available space:{0, 15} bytes", d.TotalFreeSpace);
                            drivetotalspace = String.Format("Total size of drive:{0, 15} bytes ", d.TotalSize);
                        }
                        drive = 2;
                    }
                    else if (drive == 2)
                    {
                        drivename2 = String.Format("Drive {0}", d.Name);
                        drivetype2 = String.Format("Drive type: {0}", d.DriveType);
                        if (d.IsReady == true)
                        {
                            drivevolumelabel2 = String.Format("Volume label: {0}", d.VolumeLabel);
                            drivefilesystem2 = String.Format("File system: {0}", d.DriveFormat);
                            driveuseravailablespace2 = String.Format("Available space to current user:{0, 15} bytes", d.AvailableFreeSpace);
                            driveavailablespace2 = String.Format("Total available space:{0, 15} bytes", d.TotalFreeSpace);
                            drivetotalspace2 = String.Format("Total size of drive:{0, 15} bytes ", d.TotalSize);
                        }
                        drive = 3;
                    }
                    else if (drive == 3)
                    {
                        drivename3 = String.Format("Drive {0}", d.Name);
                        drivetype3 = String.Format("Drive type: {0}", d.DriveType);
                        if (d.IsReady == true)
                        {
                            drivevolumelabel3 = String.Format("Volume label: {0}", d.VolumeLabel);
                            drivefilesystem3 = String.Format("File system: {0}", d.DriveFormat);
                            driveuseravailablespace3 = String.Format("Available space to current user:{0, 15} bytes", d.AvailableFreeSpace);
                            driveavailablespace3 = String.Format("Total available space:{0, 15} bytes", d.TotalFreeSpace);
                            drivetotalspace3 = String.Format("Total size of drive:{0, 15} bytes ", d.TotalSize);
                        }
                        drive = 4;
                    }
                    if (drive == 4)
                    {
                        drive = 1;
                    }
                }

                //part 2: possible debug - displays in output

                //drive 1
                Console.WriteLine(drivename);
                Console.WriteLine(drivetype);
                Console.WriteLine(drivevolumelabel);
                Console.WriteLine(drivefilesystem);
                Console.WriteLine(driveuseravailablespace);
                Console.WriteLine(driveavailablespace);
                Console.WriteLine(drivetotalspace);

                //drive 2
                Console.WriteLine(drivename2);
                Console.WriteLine(drivetype2);
                Console.WriteLine(drivevolumelabel2);
                Console.WriteLine(drivefilesystem2);
                Console.WriteLine(driveuseravailablespace2);
                Console.WriteLine(driveavailablespace2);
                Console.WriteLine(drivetotalspace2);

                //drive 3
                Console.WriteLine(drivename3);
                Console.WriteLine(drivetype3);
                Console.WriteLine(drivevolumelabel3);
                Console.WriteLine(drivefilesystem3);
                Console.WriteLine(driveuseravailablespace3);
                Console.WriteLine(driveavailablespace3);
                Console.WriteLine(drivetotalspace3);

I want to note that you can just make all the console writelines comment code, but i thought it would be nice for you to test it. If you display all these after each other you get the same list as waruna majuna

Drive C:\ Drive type: Fixed Volume label: File system: NTFS Available space to current user: 134880153600 bytes Total available space: 134880153600 bytes Total size of drive: 499554185216 bytes

Drive D:\ Drive type: CDRom

Drive H:\ Drive type: Fixed Volume label: HDD File system: NTFS Available space to current user: 2000010817536 bytes Total available space: 2000010817536 bytes Total size of drive: 2000263573504 bytes

However you can now acces all of the loose information at strings

Visual Studio Code: format is not using indent settings

I sometimes have this same problem. VSCode will just suddenly lose it's mind and completely ignore any indentation setting I tell it, even though it's been indenting the same file just fine all day.

I have editor.tabSize set to 2 (as well as editor.formatOnSave set to true). When VSCode messes up a file, I use the options at the bottom of the editor to change indentation type and size, hoping something will work, but VSCode insists on actually using an indent size of 4.

The fix? Restart VSCode. It should come back with the indent status showing something wrong (in my case, 4). For me, I had to change the setting and then save for it to actually make the change, but that's probably because of my editor.formatOnSave setting.

I haven't figured out why it happens, but for me it's usually when I'm editing a nested object in a JS file. It will suddenly do very strange indentation within the object, even though I've been working in that file for a while and it's been indenting just fine.

pip connection failure: cannot fetch index base URL http://pypi.python.org/simple/

You can try with this below command:

python -m pip install --trusted-host https://pypi.python.org deepdiff

it will work.

Practical uses of different data structures

Any ranking of various data structures will be at least partially tied to problem context. It would help to learn how to analyze time and space performance of algorithms. Typically, "big O notation" is used, e.g. binary search is in O(log n) time, which means that the time to search for an element is the log (in base 2, implicitly) of the number of elements. Intuitively, since every step discards half of the remaining data as irrelevant, doubling the number of elements will increases the time by 1 step. (Binary search scales rather well.) Space performance concerns how the amount of memory grows for larger data sets. Also, note that big-O notation ignores constant factors - for smaller data sets, an O(n^2) algorithm may still be faster than an O(n * log n) algorithm that has a higher constant factor. Complex algorithms often have more work to do on startup.

Besides time and space, other characteristics include whether a data structure is sorted (trees and skiplists are sorted, hash tables are not), persistence (binary trees can reuse pointers from older versions, while hash tables are modified in place), etc.

While you'll need to learn the behavior of several data structures to be able to compare them, one way to develop a sense for why they differ in performance is to closely study a few. I'd suggest comparing singly-linked lists, binary search trees, and skip lists, all of which are relatively simple, but have very different characteristics. Think about how much work it takes to find a value, add a new value, find all values in order, etc.

There are various texts on analyzing algorithms / data structure performance that people recommend, but what really made them make sense to me was learning OCaml. Dealing with complex data structures is ML's strong suit, and their behavior is much clearer when you can avoid pointers and memory management as in C. (Learning OCaml just to understand data structures is almost certainly the long way around, though. :) )

How can I put a ListView into a ScrollView without it collapsing?

We could not use two scrolling simulteniuosly.We will have get total length of ListView and expand listview with the total height .Then we can add ListView in ScrollView directly or using LinearLayout because ScrollView have directly one child . copy setListViewHeightBasedOnChildren(lv) method in your code and expand listview then you can use listview inside scrollview. \layout xml file

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

        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
         android:background="#1D1D1D"
        android:orientation="vertical"
        android:scrollbars="none" >

        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:background="#1D1D1D"
            android:orientation="vertical" >

            <TextView
                android:layout_width="fill_parent"
                android:layout_height="40dip"
                android:background="#333"
                android:gravity="center_vertical"
                android:paddingLeft="8dip"
                android:text="First ListView"
                android:textColor="#C7C7C7"
                android:textSize="20sp" />

            <ListView
                android:id="@+id/first_listview"
                android:layout_width="260dp"
                android:layout_height="wrap_content"
                android:divider="#00000000"
               android:listSelector="#ff0000"
                android:scrollbars="none" />

               <TextView
                android:layout_width="fill_parent"
                android:layout_height="40dip"
                android:background="#333"
                android:gravity="center_vertical"
                android:paddingLeft="8dip"
                android:text="Second ListView"
                android:textColor="#C7C7C7"
                android:textSize="20sp" />

            <ListView
                android:id="@+id/secondList"
                android:layout_width="260dp"
                android:layout_height="wrap_content"
                android:divider="#00000000"
                android:listSelector="#ffcc00"
                android:scrollbars="none" />
  </LinearLayout>
  </ScrollView>

   </LinearLayout>

onCreate method in Activity class:

 import java.util.ArrayList;
  import android.app.Activity;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ArrayAdapter;
 import android.widget.ListAdapter;
  import android.widget.ListView;

   public class MainActivity extends Activity {

   @Override
   protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.listview_inside_scrollview);
    ListView list_first=(ListView) findViewById(R.id.first_listview);
    ListView list_second=(ListView) findViewById(R.id.secondList);
    ArrayList<String> list=new ArrayList<String>();
    for(int x=0;x<30;x++)
    {
        list.add("Item "+x);
    }

       ArrayAdapter<String> adapter=new ArrayAdapter<String>(getApplicationContext(), 
          android.R.layout.simple_list_item_1,list);               
      list_first.setAdapter(adapter);

     setListViewHeightBasedOnChildren(list_first);

      list_second.setAdapter(adapter);

    setListViewHeightBasedOnChildren(list_second);
   }



   public static void setListViewHeightBasedOnChildren(ListView listView) {
    ListAdapter listAdapter = listView.getAdapter();
    if (listAdapter == null) {
        // pre-condition
        return;
    }

    int totalHeight = 0;
    for (int i = 0; i < listAdapter.getCount(); i++) {
        View listItem = listAdapter.getView(i, null, listView);
        listItem.measure(0, 0);
        totalHeight += listItem.getMeasuredHeight();
    }

    ViewGroup.LayoutParams params = listView.getLayoutParams();
    params.height = totalHeight
            + (listView.getDividerHeight() * (listAdapter.getCount() - 1));
    listView.setLayoutParams(params);
      }

Maximum packet size for a TCP connection

It seems most web sites out on the internet use 1460 bytes for the value of MTU. Sometimes it's 1452 and if you are on a VPN it will drop even more for the IPSec headers.

The default window size varies quite a bit up to a max of 65535 bytes. I use http://tcpcheck.com to look at my own source IP values and to check what other Internet vendors are using.

Java: splitting the filename into a base and extension

Old question but I usually use this solution:

import org.apache.commons.io.FilenameUtils;

String fileName = "/abc/defg/file.txt";

String basename = FilenameUtils.getBaseName(fileName);
String extension = FilenameUtils.getExtension(fileName);
System.out.println(basename); // file
System.out.println(extension); // txt (NOT ".txt" !)

How can I exclude a directory from Visual Studio Code "Explore" tab?

In newer versions of VS Code, you navigate to settings (Ctrl+,), and make sure to select Workspace Settings at the top right.

enter image description here

Then add a files.exclude option to specify patterns to exclude.

You can also add search.exclude if you only want to exclude a file from search results, and not from the folder explorer.

PHP - define constant inside a class

You can define a class constant in php. But your class constant would be accessible from any object instance as well. This is php's functionality. However, as of php7.1, you can define your class constants with access modifiers (public, private or protected).

A work around would be to define your constant as private or protected and then make them readable via a static function. This function should only return the constant values if called from the static context.

You can also create this static function in your parent class and simply inherit this parent class on all other classes to make it a default functionality.

Credits: http://dwellupper.io/post/48/defining-class-constants-in-php

Simple Android RecyclerView example

You can use abstract adapter with diff utils and filter

SimpleAbstractAdapter.kt

abstract class SimpleAbstractAdapter<T>(private var items: ArrayList<T> = arrayListOf()) : RecyclerView.Adapter<SimpleAbstractAdapter.VH>() {
   protected var listener: OnViewHolderListener<T>? = null
   private val filter = ArrayFilter()
   private val lock = Any()
   protected abstract fun getLayout(): Int
   protected abstract fun bindView(item: T, viewHolder: VH)
   protected abstract fun getDiffCallback(): DiffCallback<T>?
   private var onFilterObjectCallback: OnFilterObjectCallback? = null
   private var constraint: CharSequence? = ""

override fun onBindViewHolder(vh: VH, position: Int) {
    getItem(position)?.let { bindView(it, vh) }
}

override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): VH {
    return VH(parent, getLayout())
}

override fun getItemCount(): Int = items.size

protected abstract class DiffCallback<T> : DiffUtil.Callback() {
    private val mOldItems = ArrayList<T>()
    private val mNewItems = ArrayList<T>()

    fun setItems(oldItems: List<T>, newItems: List<T>) {
        mOldItems.clear()
        mOldItems.addAll(oldItems)
        mNewItems.clear()
        mNewItems.addAll(newItems)
    }

    override fun getOldListSize(): Int {
        return mOldItems.size
    }

    override fun getNewListSize(): Int {
        return mNewItems.size
    }

    override fun areItemsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
        return areItemsTheSame(
                mOldItems[oldItemPosition],
                mNewItems[newItemPosition]
        )
    }

    abstract fun areItemsTheSame(oldItem: T, newItem: T): Boolean

    override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
        return areContentsTheSame(
                mOldItems[oldItemPosition],
                mNewItems[newItemPosition]
        )
    }

    abstract fun areContentsTheSame(oldItem: T, newItem: T): Boolean
}

class VH(parent: ViewGroup, @LayoutRes layout: Int) : RecyclerView.ViewHolder(LayoutInflater.from(parent.context).inflate(layout, parent, false))

interface OnViewHolderListener<T> {
    fun onItemClick(position: Int, item: T)
}

fun getItem(position: Int): T? {
    return items.getOrNull(position)
}

fun getItems(): ArrayList<T> {
    return items
}

fun setViewHolderListener(listener: OnViewHolderListener<T>) {
    this.listener = listener
}

fun addAll(list: List<T>) {
    val diffCallback = getDiffCallback()
    when {
        diffCallback != null && !items.isEmpty() -> {
            diffCallback.setItems(items, list)
            val diffResult = DiffUtil.calculateDiff(diffCallback)
            items.clear()
            items.addAll(list)
            diffResult.dispatchUpdatesTo(this)
        }
        diffCallback == null && !items.isEmpty() -> {
            items.clear()
            items.addAll(list)
            notifyDataSetChanged()
        }
        else -> {
            items.addAll(list)
            notifyDataSetChanged()
        }
    }
}

fun add(item: T) {
    items.add(item)
    notifyDataSetChanged()
}

fun add(position:Int, item: T) {
    items.add(position,item)
    notifyItemInserted(position)
}

fun remove(position: Int) {
    items.removeAt(position)
    notifyItemRemoved(position)
}

fun remove(item: T) {
    items.remove(item)
    notifyDataSetChanged()
}

fun clear(notify: Boolean=false) {
    items.clear()
    if (notify) {
        notifyDataSetChanged()
    }
}

fun setFilter(filter: SimpleAdapterFilter<T>): ArrayFilter {
    return this.filter.setFilter(filter)
}

interface SimpleAdapterFilter<T> {
    fun onFilterItem(contains: CharSequence, item: T): Boolean
}

fun convertResultToString(resultValue: Any): CharSequence {
    return filter.convertResultToString(resultValue)
}

fun filter(constraint: CharSequence) {
    this.constraint = constraint
    filter.filter(constraint)
}

fun filter(constraint: CharSequence, listener: Filter.FilterListener) {
    this.constraint = constraint
    filter.filter(constraint, listener)
}

fun getFilter(): Filter {
    return filter
}

interface OnFilterObjectCallback {
    fun handle(countFilterObject: Int)
}

fun setOnFilterObjectCallback(objectCallback: OnFilterObjectCallback) {
    onFilterObjectCallback = objectCallback
}

inner class ArrayFilter : Filter() {
    private var original: ArrayList<T> = arrayListOf()
    private var filter: SimpleAdapterFilter<T> = DefaultFilter()
    private var list: ArrayList<T> = arrayListOf()
    private var values: ArrayList<T> = arrayListOf()


    fun setFilter(filter: SimpleAdapterFilter<T>): ArrayFilter {
        original = items
        this.filter = filter
        return this
    }

    override fun performFiltering(constraint: CharSequence?): Filter.FilterResults {
        val results = Filter.FilterResults()
        if (constraint == null || constraint.isBlank()) {
            synchronized(lock) {
                list = original
            }
            results.values = list
            results.count = list.size
        } else {
            synchronized(lock) {
                values = original
            }
            val result = ArrayList<T>()
            for (value in values) {
                if (constraint!=null && constraint.trim().isNotEmpty() && value != null) {
                    if (filter.onFilterItem(constraint, value)) {
                        result.add(value)
                    }
                } else {
                    value?.let { result.add(it) }
                }
            }
            results.values = result
            results.count = result.size
        }
        return results
    }

    override fun publishResults(constraint: CharSequence, results: Filter.FilterResults) {
        items = results.values as? ArrayList<T> ?: arrayListOf()
        notifyDataSetChanged()
        onFilterObjectCallback?.handle(results.count)
    }

}

class DefaultFilter<T> : SimpleAdapterFilter<T> {
    override fun onFilterItem(contains: CharSequence, item: T): Boolean {
        val valueText = item.toString().toLowerCase()
        if (valueText.startsWith(contains.toString())) {
            return true
        } else {
            val words = valueText.split(" ".toRegex()).dropLastWhile { it.isEmpty() }.toTypedArray()
            for (word in words) {
                if (word.contains(contains)) {
                    return true
                }
            }
        }
        return false
    }
  }
}

And extend abstract adapter with implements methods

TasksAdapter.kt

import android.annotation.SuppressLint
  import kotlinx.android.synthetic.main.task_item_layout.view.*

class TasksAdapter(private val listener:TasksListener? = null) : SimpleAbstractAdapter<Task>() {
override fun getLayout(): Int {
    return R.layout.task_item_layout
}

override fun getDiffCallback(): DiffCallback<Task>? {
    return object : DiffCallback<Task>() {
        override fun areItemsTheSame(oldItem: Task, newItem: Task): Boolean {
            return oldItem.id == newItem.id
        }

        override fun areContentsTheSame(oldItem: Task, newItem: Task): Boolean {
            return oldItem.items == newItem.items
        }
    }
}

@SuppressLint("SetTextI18n")
override fun bindView(item: Task, viewHolder: VH) {
    viewHolder.itemView.apply {
        val position = viewHolder.adapterPosition
        val customer = item.customer
        val customerName = if (customer != null) customer.name else ""
        tvTaskCommentTitle.text = customerName + ", #" + item.id
        tvCommentContent.text = item.taskAddress
        ivCall.setOnClickListener {
            listener?.onCallClick(position, item)
        }
        setOnClickListener {
            listener?.onItemClick(position, item)
        }
    }
}

 interface TasksListener : SimpleAbstractAdapter.OnViewHolderListener<Task> {
    fun onCallClick(position: Int, item: Task)
 }
}

Init adapter

mAdapter = TasksAdapter(object : TasksAdapter.TasksListener {
            override fun onCallClick(position: Int, item:Task) {
            }

            override fun onItemClick(position: Int, item:Task) {

            }
        })
rvTasks.adapter = mAdapter

and fill

mAdapter?.addAll(tasks)

add custom filter

mAdapter?.setFilter(object : SimpleAbstractAdapter.SimpleAdapterFilter<MoveTask> {
            override fun onFilterItem(contains: CharSequence, item:Task): Boolean {
                return contains.toString().toLowerCase().contains(item.id?.toLowerCase().toString())
            }
    })

filter data

mAdapter?.filter("test")

MySQL: How to reset or change the MySQL root password?

For Ubuntu 18.04 and mysql version 14.14 Distrib 5.7.22 follow the below step to reset the mysql password.

Step 1

sudo systemctl stop mysql

Step 2

sudo systemctl edit mysql

This command will open a new file in the nano editor, which you'll use to edit MySQL's service overrides. These change the default service parameters for MySQL. This file will be empty, so add the following content:

[Service]
ExecStart=
ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/run/mysqld/mysqld.pid --skip-grant-tables --skip-networking

Step 3

sudo systemctl daemon-reload
sudo systemctl start mysql

Step 4

sudo mysql -u root

Step 5

FLUSH PRIVILEGES;

Step 6

UPDATE mysql.user SET authentication_string = PASSWORD('new_password') WHEREuser = 'root';

Step 7

UPDATE mysql.user SET plugin ='mysql_native_password' WHERE user = 'root';

Step 8

sudo systemctl revert mysql

and finally

sudo systemctl restart mysql

Now enjoy

jQuery: How can I show an image popup onclick of the thumbnail?

There are a lot of jQuery plugins available for this

Thickbox

LightBox

FancyBox

FaceBox

NyroModal

PiroBox

Thickbox Examples

For a single image

  1. Create a link element ()
  2. Give the link a class attribute with a value of thickbox (class="thickbox")
  3. Provide a path in the href attribute to an image file (.jpg .jpeg .png .gif .bmp)

How to detect the screen resolution with JavaScript?

Trying to get this on a mobile device requires a few more steps. screen.availWidth stays the same regardless of the orientation of the device.

Here is my solution for mobile:

function getOrientation(){
    return Math.abs(window.orientation) - 90 == 0 ? "landscape" : "portrait";
};
function getMobileWidth(){
    return getOrientation() == "landscape" ? screen.availHeight : screen.availWidth;
};
function getMobileHeight(){
    return getOrientation() == "landscape" ? screen.availWidth : screen.availHeight;
};

Javascript to set hidden form value on drop down change

$(function() {
$('#myselect').change(function() {
   $('#myhidden').val =$("#myselect option:selected").text();
    });
});

Python requests library how to pass Authorization header with single token

This worked for me:

r = requests.get('http://127.0.0.1:8000/api/ray/musics/', headers={'Authorization': 'Token 22ec0cc4207ebead1f51dea06ff149342082b190'})

My code uses user generated token.

Moving from one activity to another Activity in Android

1) place setContentView(R.layout.avtivity_next); to the next-activity's onCreate() method just like this (main) activity's onCreate()

2) if you have not defined the next-activity in your-apps manifest file then do this also, like:

<application
        android:allowBackup="true"
        android:icon="@drawable/app_icon"
        android:label="@string/app_name" >
        <activity
            android:name=".MainActivity"
            android:label="Main Activity" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".NextActivity"
            android:label="Next Activity" >
        </activity>
    </application>

You must have to perform the 2nd step every time you create a new activity, otherwise your app will crash

Can the Android layout folder contain subfolders?

The top answer by @eski is good, but the code is not elegant to use, so I wrote a groovy script in gradle for general use. It's applied to all build type and product flavor and not only can be use for layout, you can also add subfolder for any other resources type such as drawable. Here is the code(put it in android block of project-level gradle file):

sourceSets.each {
    def rootResDir = it.res.srcDirs[0]
    def getSubDirs = { dirName ->
        def layoutsDir = new File(rootResDir, dirName)
        def subLayoutDirs = []
        if (layoutsDir.exists()) {
            layoutsDir.eachDir {
                subLayoutDirs.add it
            }
        }
        return subLayoutDirs
    }
    def resDirs = [
            "anims",
            "colors",
            "drawables",
            "drawables-hdpi",
            "drawables-mdpi",
            "drawables-xhdpi",
            "drawables-xxhdpi",
            "layouts",
            "valuess",
    ]
    def srcDirs = resDirs.collect {
        getSubDirs(it)
    }
    it.res.srcDirs = [srcDirs, rootResDir]
}

How to do in practice?

For example, I want to create subfolder named activity for layout, add a string by any name in resDirs variable such as layouts, then the layout xml file should be put in res\layouts\activity\layout\xxx.xml.

If I want to create subfolder named selectors for drawable, add a string by any name in resDirs variable such as drawables, then the drawable xml file should be put in res\drawables\selectors\drawable\xxx.xml.

The folder name such as layouts and drawables is defined in resDirs variable, it can be any string. All subfolder created by you such as activity or selectors are regarded as the same as res folder. So in selectors folder, we must create drawable folder additionally and put xml files in drawable folder, after that gradle can recognize the xml files as drawable normally.

Remove all padding and margin table HTML and CSS

Remove padding between cells inside the table. Just use cellpadding=0 and cellspacing=0 attributes in table tag.

How to connect to remote Redis server?

There are two ways to connect remote redis server using redis-cli:

1. Using host & port individually as options in command

redis-cli -h host -p port

If your instance is password protected

redis-cli -h host -p port -a password

e.g. if my-web.cache.amazonaws.com is the host url and 6379 is the port

Then this will be the command:

redis-cli -h my-web.cache.amazonaws.com -p 6379

if 92.101.91.8 is the host IP address and 6379 is the port:

redis-cli -h 92.101.91.8 -p 6379

command if the instance is protected with password pass123:

redis-cli -h my-web.cache.amazonaws.com -p 6379 -a pass123

2. Using single uri option in command

redis-cli -u redis://password@host:port

command in a single uri form with username & password

redis-cli -u redis://username:password@host:port

e.g. for the same above host - port configuration command would be

redis-cli -u redis://[email protected]:6379

command if username is also provided user123

redis-cli -u redis://user123:[email protected]:6379

This detailed answer was for those who wants to check all options. For more information check documentation: Redis command line usage