Programs & Examples On #Concat ws

Can I concatenate multiple MySQL rows into one field?

You can use GROUP_CONCAT:

SELECT person_id,
   GROUP_CONCAT(hobbies SEPARATOR ', ')
FROM peoples_hobbies
GROUP BY person_id;

As Ludwig stated in his comment, you can add the DISTINCT operator to avoid duplicates:

SELECT person_id,
   GROUP_CONCAT(DISTINCT hobbies SEPARATOR ', ')
FROM peoples_hobbies
GROUP BY person_id;

As Jan stated in their comment, you can also sort the values before imploding it using ORDER BY:

SELECT person_id, 
       GROUP_CONCAT(hobbies ORDER BY hobbies ASC SEPARATOR ', ')
FROM peoples_hobbies
GROUP BY person_id;

As Dag stated in his comment, there is a 1024 byte limit on the result. To solve this, run this query before your query:

SET group_concat_max_len = 2048;

Of course, you can change 2048 according to your needs. To calculate and assign the value:

SET group_concat_max_len = CAST(
                     (SELECT SUM(LENGTH(hobbies)) + COUNT(*) * LENGTH(', ')
                           FROM peoples_hobbies
                           GROUP BY person_id) AS UNSIGNED);

How to find the Center Coordinate of Rectangle?

We can calculate using mid point of line formula,

centre (x,y) =  new Point((boundRect.tl().x+boundRect.br().x)/2,(boundRect.tl().y+boundRect.br().y)/2)

How to get class object's name as a string in Javascript?

Immediately after the object is instantiatd, you can attach a property, say name, to the object and assign the string value you expect to it:

var myObj = new someClass();
myObj.name="myObj";

document.write(myObj.name);

Alternatively, the assignment can be made inside the codes of the class, i.e.

var someClass = function(P)
{ this.name=P;
  // rest of the class definition...
};

var myObj = new someClass("myObj");
document.write(myObj.name);

SQL Server error on update command - "A severe error occurred on the current command"

In my case,I was using SubQuery and had a same problem. I realized that the problem is from memory leakage.

Restarting MSSQL service cause to flush tempDb resource and free huge amount of memory. so this was solve the problem.

What is the correct way to read from NetworkStream in .NET

Setting the underlying socket ReceiveTimeout property did the trick. You can access it like this: yourTcpClient.Client.ReceiveTimeout. You can read the docs for more information.

Now the code will only "sleep" as long as needed for some data to arrive in the socket, or it will raise an exception if no data arrives, at the beginning of a read operation, for more than 20ms. I can tweak this timeout if needed. Now I'm not paying the 20ms price in every iteration, I'm only paying it at the last read operation. Since I have the content-length of the message in the first bytes read from the server I can use it to tweak it even more and not try to read if all expected data has been already received.

I find using ReceiveTimeout much easier than implementing asynchronous read... Here is the working code:

string SendCmd(string cmd, string ip, int port)
{
  var client = new TcpClient(ip, port);
  var data = Encoding.GetEncoding(1252).GetBytes(cmd);
  var stm = client.GetStream();
  stm.Write(data, 0, data.Length);
  byte[] resp = new byte[2048];
  var memStream = new MemoryStream();
  var bytes = 0;
  client.Client.ReceiveTimeout = 20;
  do
  {
      try
      {
          bytes = stm.Read(resp, 0, resp.Length);
          memStream.Write(resp, 0, bytes);
      }
      catch (IOException ex)
      {
          // if the ReceiveTimeout is reached an IOException will be raised...
          // with an InnerException of type SocketException and ErrorCode 10060
          var socketExept = ex.InnerException as SocketException;
          if (socketExept == null || socketExept.ErrorCode != 10060)
              // if it's not the "expected" exception, let's not hide the error
              throw ex;
          // if it is the receive timeout, then reading ended
          bytes = 0;
      }
  } while (bytes > 0);
  return Encoding.GetEncoding(1252).GetString(memStream.ToArray());
}

Create numpy matrix filled with NaNs

Yet another possibility not yet mentioned here is to use NumPy tile:

a = numpy.tile(numpy.nan, (3, 3))

Also gives

array([[ NaN,  NaN,  NaN],
       [ NaN,  NaN,  NaN],
       [ NaN,  NaN,  NaN]])

I don't know about speed comparison.

How do I clear all variables in the middle of a Python script?

No, you are best off restarting the interpreter

IPython is an excellent replacement for the bundled interpreter and has the %reset command which usually works

How do I use .toLocaleTimeString() without displaying seconds?

You can try this, which is working for my needs.

var d = new Date();
d.toLocaleTimeString().replace(/:\d{2}\s/,' ');

or

d.toLocaleString().replace(/:\d{2}\s/,' ');

What is the basic difference between the Factory and Abstract Factory Design Patterns?

I have some points to contribute with John's answer as follows:

Abstract factory is a factory of factories!

With the "Factory Method" (because just "Factory" is ambiguous), you produce implementations (Lemon, Orange, etc.) of a particular interface -- say, IFruit. This Factory could be called CitricFruitFactory.

But now you want to create another kinds of fruit that the CitricFruitFactory is not able to create. Maybe the code of CitricFruitFactory wouldn't make sense if you create an Strawberry in it (strawberry is not a citric fruit!).

So you could create a new Factory called RedFruitFactory that produces Strawberry, Raspberry, etc.

Like John Feminella said: "With the Abstract Factory pattern, you produce implementations of a particular Factory interface -- e.g., IFruitFactory. Each of those knows how to create different kinds of fruit."

That implementatios of IFruitFactory are CitricFruitFactory and RedFruitFactory!

How to replace text of a cell based on condition in excel

You can use the Conditional Formatting to replace text and NOT effect any formulas. Simply go to the Rule's format where you will see Number, Font, Border and Fill.
Go to the Number tab and select CUSTOM. Then simply type where it says TYPE: what you want to say in QUOTES.

Example.. "OTHER"

read file in classpath

Change . to / as the path separator and use getResourceAsStream:

reader = new BufferedReader(new InputStreamReader(
    getClass().getClassLoader().getResourceAsStream(
        "com/company/app/dao/sql/SqlQueryFile.sql")));

or

reader = new BufferedReader(new InputStreamReader(
    getClass().getResourceAsStream(
        "/com/company/app/dao/sql/SqlQueryFile.sql")));

Note the leading slash when using Class.getResourceAsStream() vs ClassLoader.getResourceAsStream. getSystemResourceAsStream uses the system classloader which isn't what you want.

I suspect that using slashes instead of dots would work for ClassPathResource too.

Postgresql SELECT if string contains

I personally prefer the simpler syntax of the ~ operator.

SELECT id FROM TAG_TABLE WHERE 'aaaaaaaa' ~ tag_name;

Worth reading through Difference between LIKE and ~ in Postgres to understand the difference. `

Find and extract a number from a string

Just use a RegEx to match the string, then convert:

Match match = Regex.Match(test , @"(\d+)");
if (match.Success) {
   return int.Parse(match.Groups[1].Value);
}

set serveroutput on in oracle procedure

To understand the use of "SET SERVEROUTPUT ON" I will take an example

DECLARE
a number(10)  :=10;
BEGIN
dbms_output.put_line(a) ;
dbms_output.put_line('Hello World ! ')  ;
END ;

With an output : PL/SQl procedure successfully completed i.e without the expected output

And the main reason behind is that ,whatever we pass inside dbms_output.put_line(' ARGUMENT '/VALUES) i.e. ARGUMENT/VALUES , is internally stored inside a buffer in SGA(Shared Global Area ) memory area upto 2000 bytes .

*NOTE :***However one should note that this buffer is only created when we use **dbms_output package. And we need to set the environment variable only once for a session !!

And in order to fetch it from that buffer we need to set the environment variable for the session . It makes a lot of confusion to the beginners that we are setting the server output on ( because of its nomenclature ) , but unfortunately its nothing like that . Using SET SERVER OUTPUT ON are just telling the PL/SQL engine that

*Hey please print the ARGUMENT/VALUES that I will be passing inside dbms_output.put_line
and in turn PL/SQl run time engine prints the argument on the main console .

I think I am clear to you all . Wish you all the best . To know more about it with the architectural structure of Oracle Server Engine you can see my answer on Quora http://qr.ae/RojAn8

And to answer your question "One should use SET SERVER OUTPUT in the beginning of the session. "

How can I tell if a DOM element is visible in the current viewport?

I use this function (it only checks if the y is inscreen since most of the time the x is not needed)

function elementInViewport(el) {
    var elinfo = {
        "top":el.offsetTop,
        "height":el.offsetHeight,
    };

    if (elinfo.top + elinfo.height < window.pageYOffset || elinfo.top > window.pageYOffset + window.innerHeight) {
        return false;
    } else {
        return true;
    }

}

MySQL search and replace some text in a field

In my experience, the fastest method is

UPDATE table_name SET field = REPLACE(field, 'foo', 'bar') WHERE field LIKE '%foo%';

The INSTR() way is the second-fastest and omitting the WHERE clause altogether is slowest, even if the column is not indexed.

Add characters to a string in Javascript

To use String.concat, you need to replace your existing text, since the function does not act by reference.

var text ="";
for (var member in list) {
        text = text.concat(list[member]);
}

Of course, the join() or += suggestions offered by others will work fine as well.

How to make a promise from setTimeout

Implementation:

// Promisify setTimeout
const pause = (ms, cb, ...args) =>
  new Promise((resolve, reject) => {
    setTimeout(async () => {
      try {
        resolve(await cb?.(...args))
      } catch (error) {
        reject(error)
      }
    }, ms)
  })

Tests:

// Test 1
pause(1000).then(() => console.log('called'))
// Test 2
pause(1000, (a, b, c) => [a, b, c], 1, 2, 3).then(value => console.log(value))
// Test 3
pause(1000, () => {
  throw Error('foo')
}).catch(error => console.error(error))

What are the proper permissions for an upload folder with PHP/Apache?

I would support the idea of creating a ftp group that will have the rights to upload. However, i don't think it is necessary to give 775 permission. 7 stands for read, write, execute. Normally you want to allow certain groups to read and write, but depending on the case, execute may not be necessary.

How to find list intersection?

This is an example when you need Each element in the result should appear as many times as it shows in both arrays.

def intersection(nums1, nums2):
    #example:
    #nums1 = [1,2,2,1]
    #nums2 = [2,2]
    #output = [2,2]
    #find first 2 and remove from target, continue iterating

    target, iterate = [nums1, nums2] if len(nums2) >= len(nums1) else [nums2, nums1] #iterate will look into target

    if len(target) == 0:
            return []

    i = 0
    store = []
    while i < len(iterate):

         element = iterate[i]

         if element in target:
               store.append(element)
               target.remove(element)

         i += 1


    return store

Deploying my application at the root in Tomcat

Adding on to @Rob Hruska's sol, this setting in server.xml inside section works:

<Context path="" docBase="gateway" reloadable="true" override="true"> </Context>

Note: override="true" might be required in some cases.

How to permanently add a private key with ssh-add on Ubuntu?

very simple ^_^ two steps

1.yum install keychain

2.add code below to .bash_profile

/usr/bin/keychain $HOME/.ssh/id_dsa
source $HOME/.keychain/$HOSTNAME-sh

Spring mvc @PathVariable

Have a look at the below code snippet.

@RequestMapping(value="/Add/{type}")
public ModelAndView addForm(@PathVariable String type ){
    ModelAndView modelAndView = new ModelAndView();
    modelAndView.setViewName("addContent");
    modelAndView.addObject("typelist",contentPropertyDAO.getType() );
    modelAndView.addObject("property",contentPropertyDAO.get(type,0) );
    return modelAndView;
}

Hope it helps in constructing your code.

Image, saved to sdcard, doesn't appear in Android's Gallery app

Use this after saving the image

sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://"+ Environment.getExternalStorageDirectory())));

Generate random 5 characters string

$rand = substr(md5(microtime()),rand(0,26),5);

Would be my best guess--Unless you're looking for special characters, too:

$seed = str_split('abcdefghijklmnopqrstuvwxyz'
                 .'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
                 .'0123456789!@#$%^&*()'); // and any other characters
shuffle($seed); // probably optional since array_is randomized; this may be redundant
$rand = '';
foreach (array_rand($seed, 5) as $k) $rand .= $seed[$k];

Example

And, for one based on the clock (fewer collisions since it's incremental):

function incrementalHash($len = 5){
  $charset = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
  $base = strlen($charset);
  $result = '';

  $now = explode(' ', microtime())[1];
  while ($now >= $base){
    $i = $now % $base;
    $result = $charset[$i] . $result;
    $now /= $base;
  }
  return substr($result, -5);
}

Note: incremental means easier to guess; If you're using this as a salt or a verification token, don't. A salt (now) of "WCWyb" means 5 seconds from now it's "WCWyg")

How to get overall CPU usage (e.g. 57%) on Linux

You can try:

top -bn1 | grep "Cpu(s)" | \
           sed "s/.*, *\([0-9.]*\)%* id.*/\1/" | \
           awk '{print 100 - $1"%"}'

How to specify test directory for mocha?

As @jeff-dickey suggested, in the root of your project, make a folder called test. In that folder, make a file called mocha.opts. Now where I try to improve on Jeff's answer, what worked for me was instead of specifying the name of just one test folder, I specified a pattern to find all tests to run in my project by adding this line:

*/tests/*.js --recursive in mocha.opts

If you instead want to specify the exact folders to look for tests in, I did something like this:

shared/tests/*.js --recursive
server/tests/graph/*.js --recursive

I hope this helps anyone who needed more than what the other answers provide

R: Print list to a text file

Another way

writeLines(unlist(lapply(mylist, paste, collapse=" ")))

How to iterate over the files of a certain directory, in Java?

Here is an example that lists all the files on my desktop. you should change the path variable to your path.

Instead of printing the file's name with System.out.println, you should place your own code to operate on the file.

public static void main(String[] args) {
    File path = new File("c:/documents and settings/Zachary/desktop");

    File [] files = path.listFiles();
    for (int i = 0; i < files.length; i++){
        if (files[i].isFile()){ //this line weeds out other directories/folders
            System.out.println(files[i]);
        }
    }
}

How to get body of a POST in php?

A possible reason for an empty $_POST is that the request is not POST, or not POST anymore... It may have started out as post, but encountered a 301 or 302 redirect somewhere, which is switched to GET!

Inspect $_SERVER['REQUEST_METHOD'] to check if this is the case.

See https://stackoverflow.com/a/19422232/109787 for a good discussion of why this should not happen but still does.

Difference between 2 dates in SQLite

In my case, I have to calculate the difference in minutes and julianday() does not give an accurate value. Instead, I use strftime():

SELECT (strftime('%s', [UserEnd]) - strftime('%s', [UserStart])) / 60

Both dates are converted to unixtime (seconds), then subtracted to get value in seconds between the two dates. Next, divide it by 60.

https://www.sqlite.org/cvstrac/wiki?p=DateAndTimeFunctions

Check if Nullable Guid is empty in c#

You should use the HasValue property:

SomeProperty.HasValue

For example:

if (SomeProperty.HasValue)
{
    // Do Something
}
else
{
    // Do Something Else
}

FYI

public Nullable<System.Guid> SomeProperty { get; set; }

is equivalent to:

public System.Guid? SomeProperty { get; set; }

The MSDN Reference: http://msdn.microsoft.com/en-us/library/sksw8094.aspx

Relative paths in Python

It's 2018 now, and Python have already evolve to the __future__ long time ago. So how about using the amazing pathlib coming with Python 3.4 to accomplish the task instead of struggling with os, os.path, glob, shutil, etc.

So we have 3 paths here (possibly duplicated):

  • mod_path: which is the path of the simple helper script
  • src_path: which contains a couple of template files waiting to be copied.
  • cwd: current directory, the destination of those template files.

and the problem is: we don't have the full path of src_path, only know it's relative path to the mod_path.

Now let's solve this with the the amazing pathlib:

# Hope you don't be imprisoned by legacy Python code :)
from pathlib import Path

# `cwd`: current directory is straightforward
cwd = Path.cwd()

# `mod_path`: According to the accepted answer and combine with future power
# if we are in the `helper_script.py`
mod_path = Path(__file__).parent
# OR if we are `import helper_script`
mod_path = Path(helper_script.__file__).parent

# `src_path`: with the future power, it's just so straightforward
relative_path_1 = 'same/parent/with/helper/script/'
relative_path_2 = '../../or/any/level/up/'
src_path_1 = (mod_path / relative_path_1).resolve()
src_path_2 = (mod_path / relative_path_2).resolve()

In the future, it just that simple. :D


Moreover, we can select and check and copy/move those template files with pathlib:

if src_path != cwd:
    # When we have different types of files in the `src_path`
    for template_path in src_path.glob('*.ini'):
        fname = template_path.name
        target = cwd / fname
        if not target.exists():
            # This is the COPY action
            with target.open(mode='wb') as fd:
                fd.write(template_path.read_bytes())
            # If we want MOVE action, we could use:
            # template_path.replace(target)

Can't get Gulp to run: cannot find module 'gulp-util'

I had the same issue, although the module that it was downloading was different. The only resolution to the problem is run the below command again:

npm install

Truncate (not round off) decimal numbers in javascript

Number.prototype.trim = function(decimals) {
    var s = this.toString();
    var d = s.split(".");
    d[1] = d[1].substring(0, decimals);
    return parseFloat(d.join("."));
}

console.log((5.676).trim(2)); //logs 5.67

break statement in "if else" - java

The issue is that you are trying to have multiple statements in an if without using {}. What you currently have is interpreted like:

if( choice==5 )
{
    System.out.println( ... );
}
break;
else
{
    //...
}

You really want:

if( choice==5 )
{
    System.out.println( ... );
    break;
}
else
{
    //...
}

Also, as Farce has stated, it would be better to use else if for all the conditions instead of if because if choice==1, it will still go through and check if choice==5, which would fail, and it will still go into your else block.

if( choice==1 )
    //...
else if( choice==2 )
    //...
else if( choice==3 )
    //...
else if( choice==4 )
    //...
else if( choice==5 )
{
    //...
}
else
    //...

A more elegant solution would be using a switch statement. However, break only breaks from the most inner "block" unless you use labels. So you want to label your loop and break from that if the case is 5:

LOOP:
for(;;)
{
    System.out.println("---> Your choice: ");
    choice = input.nextInt();
    switch( choice )
    {
        case 1:
            playGame();
            break;
        case 2:
            loadGame();
            break;
        case 2:
            options();
            break;
        case 4:
            credits();
            break;
        case 5:
            System.out.println("End of Game\n Thank you for playing with us!");
            break LOOP;
        default:
            System.out.println( ... );
    }
}

Instead of labeling the loop, you could also use a flag to tell the loop to stop.

bool finished = false;
while( !finished )
{
    switch( choice )
    {
        // ...
        case 5:
            System.out.println( ... )
            finished = true;
            break;
        // ...
    }
}

Determine when a ViewPager changes pages

ViewPager.setOnPageChangeListener is deprecated now. You now need to use ViewPager.addOnPageChangeListener instead.

for example,

viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

        }

        @Override
        public void onPageSelected(int position) {

        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

Redirect within component Angular 2

first configure routing

import {RouteConfig, Router, ROUTER_DIRECTIVES} from 'angular2/router';

and

@RouteConfig([
  { path: '/addDisplay', component: AddDisplay, as: 'addDisplay' },
  { path: '/<secondComponent>', component: '<secondComponentName>', as: 'secondComponentAs' },
])

then in your component import and then inject Router

import {Router} from 'angular2/router'

export class AddDisplay {
  constructor(private router: Router)
}

the last thing you have to do is to call

this.router.navigateByUrl('<pathDefinedInRouteConfig>');

or

this.router.navigate(['<aliasInRouteConfig>']);

HTML5 Audio Looping

Your code works for me on Chrome (5.0.375), and Safari (5.0). Doesn't loop on Firefox (3.6).

See example.

var song = new Audio("file");
song.loop = true;
document.body.appendChild(song);?

Scrolling to element using webdriver?

In addition to move_to_element() and scrollIntoView() I wanted to pose the following code which attempts to center the element in the view:

desired_y = (element.size['height'] / 2) + element.location['y']
window_h = driver.execute_script('return window.innerHeight')
window_y = driver.execute_script('return window.pageYOffset')
current_y = (window_h / 2) + window_y
scroll_y_by = desired_y - current_y

driver.execute_script("window.scrollBy(0, arguments[0]);", scroll_y_by)

MySQL SELECT DISTINCT multiple columns

I know that the question is too old, anyway:

select a, b from mytable group by a, b

will give your all the combinations.

How to Create a Form Dynamically Via Javascript

some thing as follows ::

Add this After the body tag

This is a rough sketch, you will need to modify it according to your needs.

<script>
var f = document.createElement("form");
f.setAttribute('method',"post");
f.setAttribute('action',"submit.php");

var i = document.createElement("input"); //input element, text
i.setAttribute('type',"text");
i.setAttribute('name',"username");

var s = document.createElement("input"); //input element, Submit button
s.setAttribute('type',"submit");
s.setAttribute('value',"Submit");

f.appendChild(i);
f.appendChild(s);

//and some more input elements here
//and dont forget to add a submit button

document.getElementsByTagName('body')[0].appendChild(f);

</script>

Android LinearLayout : Add border with shadow around a LinearLayout

Ya Mahdi aj---for RelativeLayout

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="rectangle">
            <gradient
                android:startColor="#7d000000"
                android:endColor="@android:color/transparent"
                android:angle="90" >
            </gradient>
            <corners android:radius="2dp" />
        </shape>
    </item>

    <item
        android:left="0dp"
        android:right="3dp"
        android:top="0dp"
        android:bottom="3dp">
        <shape android:shape="rectangle">
            <padding
                android:bottom="40dp"
                android:top="40dp"
                android:right="10dp"
                android:left="10dp"
                >
            </padding>
            <solid android:color="@color/Whitetransparent"/>
            <corners android:radius="2dp" />
        </shape>
    </item>
</layer-list>

adding css class to multiple elements

Try using:

.button input, .button a {
    // css stuff
}

Also, read up on CSS.

Edit: If it were me, I'd add the button class to the element, not to the parent tag. Like so:

HTML:

<a href="#" class='button'>BUTTON TEXT</a>
<input type="submit" class='button' value='buttontext' />

CSS:

.button {
    // css stuff
}

For specific css stuff use:

input.button {
    // css stuff
}
a.button {
    // css stuff
}

ping response "Request timed out." vs "Destination Host unreachable"

As I understand it, "request timeout" means the ICMP packet reached from one host to the other host but the reply could not reach the requesting host. There may be more packet loss or some physical issue. "destination host unreachable" means there is no proper route defined between two hosts.

Python - Locating the position of a regex match in a string?

I don't think this question has been completely answered yet because all of the answers only give single match examples. The OP's question demonstrates the nuances of having 2 matches as well as a substring match which should not be reported because it is not a word/token.

To match multiple occurrences, one might do something like this:

iter = re.finditer(r"\bis\b", String)
indices = [m.start(0) for m in iter]

This would return a list of the two indices for the original string.

How do I read a date in Excel format in Python?

After testing and a few days wait for feedback, I'll svn-commit the following whole new function in xlrd's xldate module ... note that it won't be available to the diehards still running Python 2.1 or 2.2.

##
# Convert an Excel number (presumed to represent a date, a datetime or a time) into
# a Python datetime.datetime
# @param xldate The Excel number
# @param datemode 0: 1900-based, 1: 1904-based.
# <br>WARNING: when using this function to
# interpret the contents of a workbook, you should pass in the Book.datemode
# attribute of that workbook. Whether
# the workbook has ever been anywhere near a Macintosh is irrelevant.
# @return a datetime.datetime object, to the nearest_second.
# <br>Special case: if 0.0 <= xldate < 1.0, it is assumed to represent a time;
# a datetime.time object will be returned.
# <br>Note: 1904-01-01 is not regarded as a valid date in the datemode 1 system; its "serial number"
# is zero.
# @throws XLDateNegative xldate < 0.00
# @throws XLDateAmbiguous The 1900 leap-year problem (datemode == 0 and 1.0 <= xldate < 61.0)
# @throws XLDateTooLarge Gregorian year 10000 or later
# @throws XLDateBadDatemode datemode arg is neither 0 nor 1
# @throws XLDateError Covers the 4 specific errors

def xldate_as_datetime(xldate, datemode):
    if datemode not in (0, 1):
        raise XLDateBadDatemode(datemode)
    if xldate == 0.00:
        return datetime.time(0, 0, 0)
    if xldate < 0.00:
        raise XLDateNegative(xldate)
    xldays = int(xldate)
    frac = xldate - xldays
    seconds = int(round(frac * 86400.0))
    assert 0 <= seconds <= 86400
    if seconds == 86400:
        seconds = 0
        xldays += 1
    if xldays >= _XLDAYS_TOO_LARGE[datemode]:
        raise XLDateTooLarge(xldate)

    if xldays == 0:
        # second = seconds % 60; minutes = seconds // 60
        minutes, second = divmod(seconds, 60)
        # minute = minutes % 60; hour    = minutes // 60
        hour, minute = divmod(minutes, 60)
        return datetime.time(hour, minute, second)

    if xldays < 61 and datemode == 0:
        raise XLDateAmbiguous(xldate)

    return (
        datetime.datetime.fromordinal(xldays + 693594 + 1462 * datemode)
        + datetime.timedelta(seconds=seconds)
        )

Getting error: ISO C++ forbids declaration of with no type

You forgot the return types in your member function definitions:

int ttTree::ttTreeInsert(int value) { ... }
^^^               

and so on.

Http Post request with content type application/x-www-form-urlencoded not working in Spring

you should replace @RequestBody with @RequestParam, and do not accept parameters with a java entity.

Then you controller is probably like this:

@RequestMapping(value = "/patientdetails", method = RequestMethod.POST, 
consumes = {MediaType.APPLICATION_FORM_URLENCODED_VALUE})
public @ResponseBody List<PatientProfileDto> getPatientDetails(
    @RequestParam Map<String, String> name) {
   List<PatientProfileDto> list = new ArrayList<PatientProfileDto>();
   ...
   PatientProfileDto patientProfileDto = mapToPatientProfileDto(mame);
   ...
   list = service.getPatient(patientProfileDto);
   return list;
}

How to clear textarea on click?

jQuery attribute val() should do the job. You can do $('#YourTextareaID').click(function(e) { e.target.value = ''; }).

Unresolved reference issue in PyCharm

The easiest way to fix it is by doing the following in your pyCharm software:

Click on: File > Settings > (Project: your project name) > Project Interpreter >

then click on the "+" icon on the right side to search for the package you want and install it.

Enjoy coding !!!

Converting NumPy array into Python List structure?

tolist() works fine even if encountered a nested array, say a pandas DataFrame;

my_list = [0,1,2,3,4,5,4,3,2,1,0]
my_dt = pd.DataFrame(my_list)
new_list = [i[0] for i in my_dt.values.tolist()]

print(type(my_list),type(my_dt),type(new_list))

How to pass parameters to a Script tag?

Got it. Kind of a hack, but it works pretty nice:

var params = document.body.getElementsByTagName('script');
query = params[0].classList;
var param_a = query[0];
var param_b = query[1];
var param_c = query[2];

I pass the params in the script tag as classes:

<script src="http://path.to/widget.js" class="2 5 4"></script>

This article helped a lot.

How to construct a std::string from a std::vector<char>?

I think you can just do

std::string s( MyVector.begin(), MyVector.end() );

where MyVector is your std::vector.

How to set Android camera orientation properly?

This solution will work for all versions of Android. You can use reflection in Java to make it work for all Android devices:

Basically you should create a reflection wrapper to call the Android 2.2 setDisplayOrientation, instead of calling the specific method.

The method:

    protected void setDisplayOrientation(Camera camera, int angle){
    Method downPolymorphic;
    try
    {
        downPolymorphic = camera.getClass().getMethod("setDisplayOrientation", new Class[] { int.class });
        if (downPolymorphic != null)
            downPolymorphic.invoke(camera, new Object[] { angle });
    }
    catch (Exception e1)
    {
    }
}

And instead of using camera.setDisplayOrientation(x) use setDisplayOrientation(camera, x) :

    if (Integer.parseInt(Build.VERSION.SDK) >= 8)
        setDisplayOrientation(mCamera, 90);
    else
    {
        if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT)
        {
            p.set("orientation", "portrait");
            p.set("rotation", 90);
        }
        if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE)
        {
            p.set("orientation", "landscape");
            p.set("rotation", 90);
        }
    }   

AngularJS : ng-model binding not updating when changed with jQuery

Try this

var selectedDueDateField = document.getElementById("selectedDueDate");
var element = angular.element(selectedDueDateField);
element.val('new value here');
element.triggerHandler('input');

Disable submit button when form invalid with AngularJS

You need to use the name of your form, as well as ng-disabled: Here's a demo on Plunker

<form name="myForm">
    <input name="myText" type="text" ng-model="mytext" required />
    <button ng-disabled="myForm.$invalid">Save</button>
</form>

What can MATLAB do that R cannot do?

We can't because it's expected/required by our customers.

Copy/Paste/Calculate Visible Cells from One Column of a Filtered Table

Just to add to Jon's coding if you needed to take it a step further, and do more than just one column you can add something like

Dim copyRange2 As Range
Dim copyRange3 As Range

Set copyRange2 =src.Range("B2:B" & lastRow)
Set copyRange3 =src.Range("C2:C" & lastRow)

copyRange2.SpecialCells(xlCellTypeVisible).Copy tgt.Range("B12")
copyRange3.SpecialCells(xlCellTypeVisible).Copy tgt.Range("C12")

put these near the other codings that are the same you can easily change the Ranges as you need.

I only add this because it was helpful for me. I'd assume Jon already knows this but for those that are less experienced sometimes it's helpful to see how to change/add/modify these codings. I figured since Ruya didn't know how to manipulate the original coding it could be helpful if one ever needed to copy over only 2 visibile columns, or only 3, etc. You can use this same coding, add in extra lines that are almost the same and then the coding is copying over whatever you need.

I don't have enough reputation to reply to Jon's comment directly so I have to post as a new comment, sorry.

jQuery.active function

For anyone trying to use jQuery.active with JSONP requests (like I was) you'll need enable it with this:

jQuery.ajaxPrefilter(function( options ) {
    options.global = true;
});

Keep in mind that you'll need a timeout on your JSONP request to catch failures.

What are the Differences Between "php artisan dump-autoload" and "composer dump-autoload"?

composer dump-autoload

PATH vendor/composer/autoload_classmap.php
  • Composer dump-autoload won’t download a thing.
  • It just regenerates the list of all classes that need to be included in the project (autoload_classmap.php).
  • Ideal for when you have a new class inside your project.
  • autoload_classmap.php also includes the providers in config/app.php

php artisan dump-autoload

  • It will call Composer with the optimize flag
  • It will 'recompile' loads of files creating the huge bootstrap/compiled.php

pythonic way to do something N times without an index variable?

Assume that you've defined do_something as a function, and you'd like to perform it N times. Maybe you can try the following:

todos = [do_something] * N  
for doit in todos:  
    doit()

Why can I ping a server but not connect via SSH?

ping (ICMP protocol) and ssh are two different protocols.

  1. It could be that ssh service is not running or not installed

  2. firewall restriction (local to server like iptables or even sshd config lock down ) or (external firewall that protects incomming traffic to network hosting 111.111.111.111)

First check is to see if ssh port is up

nc -v -w 1 111.111.111.111 -z 22

if it succeeds then ssh should communicate if not then it will never work until restriction is lifted or ssh is started

Passing a method parameter using Task.Factory.StartNew

Construct the first parameter as an instance of Action, e.g.

var inputID = 123;
var col = new BlockingDataCollection();
var task = Task.Factory.StartNew(
    () => CheckFiles(inputID, col),
    cancelCheckFile.Token,
    TaskCreationOptions.LongRunning,
    TaskScheduler.Default);

set dropdown value by text using jquery

This is worked both chrome and firefox

set value in to dropdown box.

var given = $("#anotherbox").val();
$("#HowYouKnow").text(given).attr('value', given);

How can I get the current screen orientation?

In your activity class use the method below :

 @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);

        // Checks the orientation of the screen
        if (newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE) {

            setlogo();// Your Method
            Log.d("Daiya", "ORIENTATION_LANDSCAPE");

        } else if (newConfig.orientation == Configuration.ORIENTATION_PORTRAIT) {

            setlogoForLandScape();// Your Method
            Log.d("Daiya", "ORIENTATION_PORTRAIT");
        }
    }

Then to declare that your activity handles a configuration change, edit the appropriate element in your manifest file to include the android:configChanges attribute with a value that represents the configuration you want to handle. Possible values are listed in the documentation for the android:configChanges attribute (the most commonly used values are "orientation" to prevent restarts when the screen orientation changes and "keyboardHidden" to prevent restarts when the keyboard availability changes). You can declare multiple configuration values in the attribute by separating them with a pipe | character.

<activity android:name=".MyActivity"
          android:configChanges="orientation|keyboardHidden"
          android:label="@string/app_name">

That's all!!

PHP Checking if the current date is before or after a set date

if( strtotime($database_date) > strtotime('now') ) {
...

How to use localization in C#

It's quite simple, actually. Create a new resource file, for example Strings.resx. Set Access Modifier to Public. Use the apprioriate file template, so Visual Studio will automatically generate an accessor class (the name will be Strings, in this case). This is your default language.

Now, when you want to add, say, German localization, add a localized resx file. This will be typically Strings.de.resx in this case. If you want to add additional localization for, say, Austria, you'll additionally create a Strings.de-AT.resx.

Now go create a string - let's say a string with the name HelloWorld. In your Strings.resx, add this string with the value "Hello, world!". In Strings.de.resx, add "Hallo, Welt!". And in Strings.de-AT.resx, add "Servus, Welt!". That's it so far.

Now you have this generated Strings class, and it has a property with a getter HelloWorld. Getting this property will load "Servus, Welt!" when your locale is de-AT, "Hallo, Welt! when your locale is any other de locale (including de-DE and de-CH), and "Hello, World!" when your locale is anything else. If a string is missing in the localized version, the resource manager will automatically walk up the chain, from the most specialized to the invariant resource.

You can use the ResourceManager class for more control about how exactly you are loading things. The generated Strings class uses it as well.

C# Ignore certificate errors?

To disable ssl cert validation in client configuration.

<behaviors>
   <endpointBehaviors>
      <behavior name="DisableSSLCertificateValidation">
         <clientCredentials>
             <serviceCertificate>
                <sslCertificateAuthentication certificateValidationMode="None" />
              </serviceCertificate>
           </clientCredentials>
        </behavior>

The difference between fork(), vfork(), exec() and clone()

  1. fork() - creates a new child process, which is a complete copy of the parent process. Child and parent processes use different virtual address spaces, which is initially populated by the same memory pages. Then, as both processes are executed, the virtual address spaces begin to differ more and more, because the operating system performs a lazy copying of memory pages that are being written by either of these two processes and assigns an independent copies of the modified pages of memory for each process. This technique is called Copy-On-Write (COW).
  2. vfork() - creates a new child process, which is a "quick" copy of the parent process. In contrast to the system call fork(), child and parent processes share the same virtual address space. NOTE! Using the same virtual address space, both the parent and child use the same stack, the stack pointer and the instruction pointer, as in the case of the classic fork()! To prevent unwanted interference between parent and child, which use the same stack, execution of the parent process is frozen until the child will call either exec() (create a new virtual address space and a transition to a different stack) or _exit() (termination of the process execution). vfork() is the optimization of fork() for "fork-and-exec" model. It can be performed 4-5 times faster than the fork(), because unlike the fork() (even with COW kept in the mind), implementation of vfork() system call does not include the creation of a new address space (the allocation and setting up of new page directories).
  3. clone() - creates a new child process. Various parameters of this system call, specify which parts of the parent process must be copied into the child process and which parts will be shared between them. As a result, this system call can be used to create all kinds of execution entities, starting from threads and finishing by completely independent processes. In fact, clone() system call is the base which is used for the implementation of pthread_create() and all the family of the fork() system calls.
  4. exec() - resets all the memory of the process, loads and parses specified executable binary, sets up new stack and passes control to the entry point of the loaded executable. This system call never return control to the caller and serves for loading of a new program to the already existing process. This system call with fork() system call together form a classical UNIX process management model called "fork-and-exec".

delete word after or around cursor in VIM

In old vi, b moves the cursor to the beginning of the word before cursor, w moves the cursor to the beginning of the word after cursor, e moves cursor at the end of the word after cursor and dw deletes from the cursor to the end of the word.

If you type wbdw, you delete the word around cursor, even if the cursor is at the beginning or at the end of the word. Note that whitespaces after a word are considerer to be part of the word to be deleted.

Get element from within an iFrame

var iframe = document.getElementById('iframeId');
var innerDoc = (iframe.contentDocument) ? iframe.contentDocument : iframe.contentWindow.document;

You could more simply write:

var iframe = document.getElementById('iframeId');
var innerDoc = iframe.contentDocument || iframe.contentWindow.document;

and the first valid inner doc will be returned.

Once you get the inner doc, you can just access its internals the same way as you would access any element on your current page. (innerDoc.getElementById...etc.)

IMPORTANT: Make sure that the iframe is on the same domain, otherwise you can't get access to its internals. That would be cross-site scripting.

Why doesn't adding CORS headers to an OPTIONS route allow browsers to access my API?

Try passing control to the next matching route. If Express is matching app.get route first, then it won't continue onto the options route unless you do this (note use of next):

app.get('somethingelse', function(req, res, next) {
    //..set headers etc.

    next();
});

In terms of organising the CORS stuff, I put it in a middleware which is working well for me:

//CORS middleware
var allowCrossDomain = function(req, res, next) {
    res.header('Access-Control-Allow-Origin', 'example.com');
    res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE');
    res.header('Access-Control-Allow-Headers', 'Content-Type');

    next();
}

//...
app.configure(function() {
    app.use(express.bodyParser());
    app.use(express.cookieParser());
    app.use(express.session({ secret: 'cool beans' }));
    app.use(express.methodOverride());
    app.use(allowCrossDomain);
    app.use(app.router);
    app.use(express.static(__dirname + '/public'));
});

Invoking JavaScript code in an iframe from the parent page

There are some quirks to be aware of here.

  1. HTMLIFrameElement.contentWindow is probably the easier way, but it's not quite a standard property and some browsers don't support it, mostly older ones. This is because the DOM Level 1 HTML standard has nothing to say about the window object.

  2. You can also try HTMLIFrameElement.contentDocument.defaultView, which a couple of older browsers allow but IE doesn't. Even so, the standard doesn't explicitly say that you get the window object back, for the same reason as (1), but you can pick up a few extra browser versions here if you care.

  3. window.frames['name'] returning the window is the oldest and hence most reliable interface. But you then have to use a name="..." attribute to be able to get a frame by name, which is slightly ugly/deprecated/transitional. (id="..." would be better but IE doesn't like that.)

  4. window.frames[number] is also very reliable, but knowing the right index is the trick. You can get away with this eg. if you know you only have the one iframe on the page.

  5. It is entirely possible the child iframe hasn't loaded yet, or something else went wrong to make it inaccessible. You may find it easier to reverse the flow of communications: that is, have the child iframe notify its window.parent script when it has finished loaded and is ready to be called back. By passing one of its own objects (eg. a callback function) to the parent script, that parent can then communicate directly with the script in the iframe without having to worry about what HTMLIFrameElement it is associated with.

How do you print in a Go test using the "testing" package?

The *_test.go file is a Go source like the others, you can initialize a new logger every time if you need to dump complex data structure, here an example:

// initZapLog is delegated to initialize a new 'log manager'
func initZapLog() *zap.Logger {
    config := zap.NewDevelopmentConfig()
    config.EncoderConfig.EncodeLevel = zapcore.CapitalColorLevelEncoder
    config.EncoderConfig.TimeKey = "timestamp"
    config.EncoderConfig.EncodeTime = zapcore.ISO8601TimeEncoder
    logger, _ := config.Build()
    return logger
}

Then, every time, in every test:

func TestCreateDB(t *testing.T) {
    loggerMgr := initZapLog()
    // Make logger avaible everywhere
    zap.ReplaceGlobals(loggerMgr)
    defer loggerMgr.Sync() // flushes buffer, if any
    logger := loggerMgr.Sugar()
    logger.Debug("START")
    conf := initConf()
    /* Your test here
    if false {
        t.Fail()
    }*/
}

How can I keep a container running on Kubernetes?

Use Kubernetes Deployment and services.

How to test my servlet using JUnit

 public class WishServletTest {
 WishServlet wishServlet;
 HttpServletRequest mockhttpServletRequest;
 HttpServletResponse mockhttpServletResponse;

@Before
public void setUp(){
    wishServlet=new WishServlet();
    mockhttpServletRequest=createNiceMock(HttpServletRequest.class);
    mockhttpServletResponse=createNiceMock(HttpServletResponse.class);
}

@Test
public void testService()throws Exception{
    File file= new File("Sample.txt");
    File.createTempFile("ashok","txt");
    expect(mockhttpServletRequest.getParameter("username")).andReturn("ashok");
    expect(mockhttpServletResponse.getWriter()).andReturn(new PrintWriter(file));
    replay(mockhttpServletRequest);
    replay(mockhttpServletResponse);
    wishServlet.doGet(mockhttpServletRequest, mockhttpServletResponse);
    FileReader fileReader=new FileReader(file);
    int count = 0;
    String str = "";
    while ( (count=fileReader.read())!=-1){
        str=str+(char)count;
    }

    Assert.assertTrue(str.trim().equals("Helloashok"));
    verify(mockhttpServletRequest);
    verify(mockhttpServletResponse);

}

}

Android: where are downloaded files saved?

Most devices have some form of emulated storage. if they support sd cards they are usually mounted to /sdcard (or some variation of that name) which is usually symlinked to to a directory in /storage like /storage/sdcard0 or /storage/0 sometimes the emulated storage is mounted to /sdcard and the actual path is something like /storage/emulated/legacy. You should be able to use to get the downloads directory. You are best off using the api calls to get directories. Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);

Since the filesystems and sdcard support varies among devices.

see similar question for more info how to access downloads folder in android?

Usually the DownloadManager handles downloads and the files are then accessed by requesting the file's uri fromthe download manager using a file id to get where file was places which would usually be somewhere in the sdcard/ real or emulated since apps can only read data from certain places on the filesystem outside of their data directory like the sdcard

What integer hash function are good that accepts an integer hash key?

I found the following algorithm provides a very good statistical distribution. Each input bit affects each output bit with about 50% probability. There are no collisions (each input results in a different output). The algorithm is fast except if the CPU doesn't have a built-in integer multiplication unit. C code, assuming int is 32 bit (for Java, replace >> with >>> and remove unsigned):

unsigned int hash(unsigned int x) {
    x = ((x >> 16) ^ x) * 0x45d9f3b;
    x = ((x >> 16) ^ x) * 0x45d9f3b;
    x = (x >> 16) ^ x;
    return x;
}

The magic number was calculated using a special multi-threaded test program that ran for many hours, which calculates the avalanche effect (the number of output bits that change if a single input bit is changed; should be nearly 16 on average), independence of output bit changes (output bits should not depend on each other), and the probability of a change in each output bit if any input bit is changed. The calculated values are better than the 32-bit finalizer used by MurmurHash, and nearly as good (not quite) as when using AES. A slight advantage is that the same constant is used twice (it did make it slightly faster the last time I tested, not sure if it's still the case).

You can reverse the process (get the input value from the hash) if you replace the 0x45d9f3b with 0x119de1f3 (the multiplicative inverse):

unsigned int unhash(unsigned int x) {
    x = ((x >> 16) ^ x) * 0x119de1f3;
    x = ((x >> 16) ^ x) * 0x119de1f3;
    x = (x >> 16) ^ x;
    return x;
}

For 64-bit numbers, I suggest to use the following, even thought it might not be the fastest. This one is based on splitmix64, which seems to be based on the blog article Better Bit Mixing (mix 13).

uint64_t hash(uint64_t x) {
    x = (x ^ (x >> 30)) * UINT64_C(0xbf58476d1ce4e5b9);
    x = (x ^ (x >> 27)) * UINT64_C(0x94d049bb133111eb);
    x = x ^ (x >> 31);
    return x;
}

For Java, use long, add L to the constant, replace >> with >>> and remove unsigned. In this case, reversing is more complicated:

uint64_t unhash(uint64_t x) {
    x = (x ^ (x >> 31) ^ (x >> 62)) * UINT64_C(0x319642b2d24d8ec3);
    x = (x ^ (x >> 27) ^ (x >> 54)) * UINT64_C(0x96de1b173f119089);
    x = x ^ (x >> 30) ^ (x >> 60);
    return x;
}

Update: You may also want to look at the Hash Function Prospector project, where other (possibly better) constants are listed.

Right align text in android TextView

In case somebody still needs

android:gravity="end"

Convert NSArray to NSString in Objective-C

NSString * result = [[array valueForKey:@"description"] componentsJoinedByString:@""];

Getting all types that implement an interface

To find all types in an assembly that implement IFoo interface:

var results = from type in someAssembly.GetTypes()
              where typeof(IFoo).IsAssignableFrom(type)
              select type;

Note that Ryan Rinaldi's suggestion was incorrect. It will return 0 types. You cannot write

where type is IFoo

because type is a System.Type instance, and will never be of type IFoo. Instead, you check to see if IFoo is assignable from the type. That will get your expected results.

Also, Adam Wright's suggestion, which is currently marked as the answer, is incorrect as well, and for the same reason. At runtime, you'll see 0 types come back, because all System.Type instances weren't IFoo implementors.

How to get the return value from a thread in python?

One usual solution is to wrap your function foo with a decorator like

result = queue.Queue()

def task_wrapper(*args):
    result.put(target(*args))

Then the whole code may looks like that

result = queue.Queue()

def task_wrapper(*args):
    result.put(target(*args))

threads = [threading.Thread(target=task_wrapper, args=args) for args in args_list]

for t in threads:
    t.start()
    while(True):
        if(len(threading.enumerate()) < max_num):
            break
for t in threads:
    t.join()
return result

Note

One important issue is that the return values may be unorderred. (In fact, the return value is not necessarily saved to the queue, since you can choose arbitrary thread-safe data structure )

How do I create an array of strings in C?

Your code is creating an array of function pointers. Try

char* a[size];

or

char a[size1][size2];

instead.

See wikibooks to arrays and pointers

Express.js Response Timeout

An update if one is using Express 4.2 then the timeout middleware has been removed so need to manually add it with

npm install connect-timeout

and in the code it has to be (Edited as per comment, how to include it in the code)

 var timeout = require('connect-timeout');
 app.use(timeout('100s'));

How can I access a hover state in reactjs?

React components expose all the standard Javascript mouse events in their top-level interface. Of course, you can still use :hover in your CSS, and that may be adequate for some of your needs, but for the more advanced behaviors triggered by a hover you'll need to use the Javascript. So to manage hover interactions, you'll want to use onMouseEnter and onMouseLeave. You then attach them to handlers in your component like so:

<ReactComponent
    onMouseEnter={() => this.someHandler}
    onMouseLeave={() => this.someOtherHandler}
/>

You'll then use some combination of state/props to pass changed state or properties down to your child React components.

How to make an element width: 100% minus padding?

Assuming i'm in a container with 15px padding, this is what i always use for the inner part:

width:auto;
right:15px;
left:15px;

That will stretch the inner part to whatever width it should be less the 15px either side.

How to list all the files in a commit?

Preferred Way (because it's a plumbing command; meant to be programmatic):

$ git diff-tree --no-commit-id --name-only -r bd61ad98
index.html
javascript/application.js
javascript/ie6.js

Another Way (less preferred for scripts, because it's a porcelain command; meant to be user-facing)

$ git show --pretty="" --name-only bd61ad98    
index.html
javascript/application.js
javascript/ie6.js

  • The --no-commit-id suppresses the commit ID output.
  • The --pretty argument specifies an empty format string to avoid the cruft at the beginning.
  • The --name-only argument shows only the file names that were affected (Thanks Hank). Use --name-status instead, if you want to see what happened to each file (Deleted, Modified, Added)
  • The -r argument is to recurse into sub-trees

How to configure Git post commit hook

As mentioned in "Polling must die: triggering Jenkins builds from a git hook", you can notify Jenkins of a new commit:

With the latest Git plugin 1.1.14 (that I just release now), you can now do this more >easily by simply executing the following command:

curl http://yourserver/jenkins/git/notifyCommit?url=<URL of the Git repository>

This will scan all the jobs that’s configured to check out the specified URL, and if they are also configured with polling, it’ll immediately trigger the polling (and if that finds a change worth a build, a build will be triggered in turn.)

This allows a script to remain the same when jobs come and go in Jenkins.
Or if you have multiple repositories under a single repository host application (such as Gitosis), you can share a single post-receive hook script with all the repositories. Finally, this URL doesn’t require authentication even for secured Jenkins, because the server doesn’t directly use anything that the client is sending. It runs polling to verify that there is a change, before it actually starts a build.

As mentioned here, make sure to use the right address for your Jenkins server:

since we're running Jenkins as standalone Webserver on port 8080 the URL should have been without the /jenkins, like this:

http://jenkins:8080/git/notifyCommit?url=git@gitserver:tools/common.git

To reinforce that last point, ptha adds in the comments:

It may be obvious, but I had issues with:

curl http://yourserver/jenkins/git/notifyCommit?url=<URL of the Git repository>. 

The url parameter should match exactly what you have in Repository URL of your Jenkins job.
When copying examples I left out the protocol, in our case ssh://, and it didn't work.


You can also use a simple post-receive hook like in "Push based builds using Jenkins and GIT"

#!/bin/bash
/usr/bin/curl --user USERNAME:PASS -s \

http://jenkinsci/job/PROJECTNAME/build?token=1qaz2wsx

Configure your Jenkins job to be able to “Trigger builds remotely” and use an authentication token (1qaz2wsx in this example).

However, this is a project-specific script, and the author mentions a way to generalize it.
The first solution is easier as it doesn't depend on authentication or a specific project.


I want to check in change set whether at least one java file is there the build should start.
Suppose the developers changed only XML files or property files, then the build should not start.

Basically, your build script can:

  • put a 'build' notes (see git notes) on the first call
  • on the subsequent calls, grab the list of commits between HEAD of your branch candidate for build and the commit referenced by the git notes 'build' (git show refs/notes/build): git diff --name-only SHA_build HEAD.
  • your script can parse that list and decide if it needs to go on with the build.
  • in any case, create/move your git notes 'build' to HEAD.

May 2016: cwhsu points out in the comments the following possible url:

you could just use curl --user USER:PWD http://JENKINS_SERVER/job/JOB_NAME/build?token=YOUR_TOKEN if you set trigger config in your item

http://i.imgur.com/IolrOOj.png


June 2016, polaretto points out in the comments:

I wanted to add that with just a little of shell scripting you can avoid manual url configuration, especially if you have many repositories under a common directory.
For example I used these parameter expansions to get the repo name

repository=${PWD%/hooks}; 
repository=${repository##*/} 

and then use it like:

curl $JENKINS_URL/git/notifyCommit?url=$GIT_URL/$repository

How to get the GL library/headers?

Debian Linux (e.g. Ubuntu)

sudo apt-get update
OpenGL: sudo apt-get install libglu1-mesa-dev freeglut3-dev mesa-common-dev

Windows

Locate your Visual Studio folder for where it puts libraries and also header files, download and copy lib files to lib folder and header files to header. Then copy dll files to system32. Then your code will 100% run.

Also Windows: For all of those includes you just need to download glut32.lib, glut.h, glut32.dll.

SVN change username

Also, for those who happened to realize too late, that they committed with the wrong credentials, the solution (after the fact) is to change the svn author of that revision: see this question

Basically the syntax is:

svn propset --revprop -r (revision_number) svn:author (new username)

How to select a range of the second row to the last row

Sub SelectAllCellsInSheet(SheetName As String)
    lastCol = Sheets(SheetName).Range("a1").End(xlToRight).Column
    Lastrow = Sheets(SheetName).Cells(1, 1).End(xlDown).Row
    Sheets(SheetName).Range("A2", Sheets(SheetName).Cells(Lastrow, lastCol)).Select
End Sub

To use with ActiveSheet:

Call SelectAllCellsInSheet(ActiveSheet.Name)

Get Substring - everything before certain char

The LINQy way

String.Concat( "223232-1.jpg".TakeWhile(c => c != '-') )

(But, you do need to test for null ;)

SaveFileDialog setting default path and file type?

The SaveFileDialog control won't do any saving at all. All it does is providing you a convenient interface to actually display Windows' default file save dialog.

  1. Set the property InitialDirectory to the drive you'd like it to show some other default. Just think of other computers that might have a different layout. By default windows will save the directory used the last time and present it again.

  2. That is handled outside the control. You'll have to check the dialog's results and then do the saving yourself (e.g. write a text or binary file).

Just as a quick example (there are alternative ways to do it). savefile is a control of type SaveFileDialog

SaveFileDialog savefile = new SaveFileDialog(); 
// set a default file name
savefile.FileName = "unknown.txt";
// set filters - this can be done in properties as well
savefile.Filter = "Text files (*.txt)|*.txt|All files (*.*)|*.*";

if (savefile.ShowDialog() == DialogResult.OK)
{
    using (StreamWriter sw = new StreamWriter(savefile.FileName))
        sw.WriteLine ("Hello World!");
}

What is the difference between onBlur and onChange attribute in HTML?

onChange is when something within a field changes eg, you write something in a text input.

onBlur is when you take focus away from a field eg, you were writing in a text input and you have clicked off it.

So really they are almost the same thing but for onChange to behave the way onBlur does something in that input needs to change.

How to directly move camera to current location in Google Maps Android API v2?

make sure you have these permissions:

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

Then make some activity and register a LocationListener

package com.example.location;

import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.View;
import com.actionbarsherlock.app.SherlockFragmentActivity;
import com.google.android.gms.maps.CameraUpdate;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;

public class LocationActivity extends SherlockFragmentActivity implements LocationListener     {
private GoogleMap map;
private LocationManager locationManager;
private static final long MIN_TIME = 400;
private static final float MIN_DISTANCE = 1000;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.map);
    map = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();

    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME, MIN_DISTANCE, this); //You can also use LocationManager.GPS_PROVIDER and LocationManager.PASSIVE_PROVIDER        
}

@Override
public void onLocationChanged(Location location) {
    LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
    CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(latLng, 10);
    map.animateCamera(cameraUpdate);
    locationManager.removeUpdates(this);
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) { }

@Override
public void onProviderEnabled(String provider) { }

@Override
public void onProviderDisabled(String provider) { }
}

map.xml

<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.SupportMapFragment"/>

'was not declared in this scope' error

You need to declare y and c outside the scope of the if/else statement. A variable is only valid inside the scope it is declared (and a scope is marked with { })

#include <iostream> 
using namespace std; 
//Using the Gaussian algorithm 
int dayofweek(int date, int month, int year ){ 
int d=date; 
int y, c;
if (month==1||month==2) 
        {y=((year-1)%100);c=(year-1)/100;} 
else 
        {y=year%100;c=year/100;} 
int m=(month+9)%12+1; 
int product=(d+(2.6*m-0.2)+y+y/4+c/4-2*c); 
return product%7; 
} 

int main(){ 
cout<<dayofweek(19,1,2054); 
return 0; 
} 

TypeError: 'function' object is not subscriptable - Python

You have two objects both named bank_holiday -- one a list and one a function. Disambiguate the two.

bank_holiday[month] is raising an error because Python thinks bank_holiday refers to the function (the last object bound to the name bank_holiday), whereas you probably intend it to mean the list.

issue ORA-00001: unique constraint violated coming in INSERT/UPDATE

Oracle's error message should be somewhat longer. It usually looks like this:

ORA-00001: unique constraint (TABLE_UK1) violated

The name in parentheses is the constrait name. It tells you which constraint was violated.

How to "comment-out" (add comment) in a batch/cmd?

You can add comments to the end of a batch file with this syntax:

@echo off
:: Start of code
...
:: End of code

(I am a comment
So I am!
This can be only at the end of batch files

Just make sure you never use a closing parentheses.

Attributions: Leo Guttirez Ramirez on https://www.robvanderwoude.com/comments.php

No resource found that matches the given name '@style/Theme.AppCompat.Light'

Below are the steps you can try it out to resolve the issue: -

  1. Provide reference of AppCompat Library into your project.
  2. If option 1 doesn't solve the issue then you can try to change the style.xml file to below code.
 parent="android:Theme.Holo.Light"  

instead.

 parent="android:Theme.AppCompat.Light"  

But option 2 will require minimum sdk version 14.

Hope this will help !

Summved

How to install Python package from GitHub?

To install Python package from github, you need to clone that repository.

git clone https://github.com/jkbr/httpie.git

Then just run the setup.py file from that directory,

sudo python setup.py install

Set cookies for cross origin requests

Note for Chrome Browser released in 2020.

A future release of Chrome will only deliver cookies with cross-site requests if they are set with SameSite=None and Secure.

So if your backend server does not set SameSite=None, Chrome will use SameSite=Lax by default and will not use this cookie with { withCredentials: true } requests.

More info https://www.chromium.org/updates/same-site.

Firefox and Edge developers also want to release this feature in the future.

Spec found here: https://tools.ietf.org/html/draft-west-cookie-incrementalism-01#page-8

How to invoke function from external .c file in C?

Change your Main.c like so

#include <stdlib.h>
#include <stdio.h>
#include "ClasseAusiliaria.h"

int main(void)
{
  int risultato;
  risultato = addizione(5,6);
  printf("%d\n",risultato);
}

Create ClasseAusiliaria.h like so

extern int addizione(int a, int b);

I then compiled and ran your code, I got an output of

11

UNION with WHERE clause

I would make sure you have an index on ColA, and then run both of them and time them. That would give you the best answer.

libclntsh.so.11.1: cannot open shared object file.

If you have problem with libclntsh.so, need create symlink for libclntsh.so from /usr/lib/oracle/11.2/client64/lib to /usr/lib

Multiple glibc libraries on a single host

Setup 1: compile your own glibc without dedicated GCC and use it

This setup might work and is quick as it does not recompile the whole GCC toolchain, just glibc.

But it is not reliable as it uses host C runtime objects such as crt1.o, crti.o, and crtn.o provided by glibc. This is mentioned at: https://sourceware.org/glibc/wiki/Testing/Builds?action=recall&rev=21#Compile_against_glibc_in_an_installed_location Those objects do early setup that glibc relies on, so I wouldn't be surprised if things crashed in wonderful and awesomely subtle ways.

For a more reliable setup, see Setup 2 below.

Build glibc and install locally:

export glibc_install="$(pwd)/glibc/build/install"

git clone git://sourceware.org/git/glibc.git
cd glibc
git checkout glibc-2.28
mkdir build
cd build
../configure --prefix "$glibc_install"
make -j `nproc`
make install -j `nproc`

Setup 1: verify the build

test_glibc.c

#define _GNU_SOURCE
#include <assert.h>
#include <gnu/libc-version.h>
#include <stdatomic.h>
#include <stdio.h>
#include <threads.h>

atomic_int acnt;
int cnt;

int f(void* thr_data) {
    for(int n = 0; n < 1000; ++n) {
        ++cnt;
        ++acnt;
    }
    return 0;
}

int main(int argc, char **argv) {
    /* Basic library version check. */
    printf("gnu_get_libc_version() = %s\n", gnu_get_libc_version());

    /* Exercise thrd_create from -pthread,
     * which is not present in glibc 2.27 in Ubuntu 18.04.
     * https://stackoverflow.com/questions/56810/how-do-i-start-threads-in-plain-c/52453291#52453291 */
    thrd_t thr[10];
    for(int n = 0; n < 10; ++n)
        thrd_create(&thr[n], f, NULL);
    for(int n = 0; n < 10; ++n)
        thrd_join(thr[n], NULL);
    printf("The atomic counter is %u\n", acnt);
    printf("The non-atomic counter is %u\n", cnt);
}

Compile and run with test_glibc.sh:

#!/usr/bin/env bash
set -eux
gcc \
  -L "${glibc_install}/lib" \
  -I "${glibc_install}/include" \
  -Wl,--rpath="${glibc_install}/lib" \
  -Wl,--dynamic-linker="${glibc_install}/lib/ld-linux-x86-64.so.2" \
  -std=c11 \
  -o test_glibc.out \
  -v \
  test_glibc.c \
  -pthread \
;
ldd ./test_glibc.out
./test_glibc.out

The program outputs the expected:

gnu_get_libc_version() = 2.28
The atomic counter is 10000
The non-atomic counter is 8674

Command adapted from https://sourceware.org/glibc/wiki/Testing/Builds?action=recall&rev=21#Compile_against_glibc_in_an_installed_location but --sysroot made it fail with:

cannot find /home/ciro/glibc/build/install/lib/libc.so.6 inside /home/ciro/glibc/build/install

so I removed it.

ldd output confirms that the ldd and libraries that we've just built are actually being used as expected:

+ ldd test_glibc.out
        linux-vdso.so.1 (0x00007ffe4bfd3000)
        libpthread.so.0 => /home/ciro/glibc/build/install/lib/libpthread.so.0 (0x00007fc12ed92000)
        libc.so.6 => /home/ciro/glibc/build/install/lib/libc.so.6 (0x00007fc12e9dc000)
        /home/ciro/glibc/build/install/lib/ld-linux-x86-64.so.2 => /lib64/ld-linux-x86-64.so.2 (0x00007fc12f1b3000)

The gcc compilation debug output shows that my host runtime objects were used, which is bad as mentioned previously, but I don't know how to work around it, e.g. it contains:

COLLECT_GCC_OPTIONS=/usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/crt1.o

Setup 1: modify glibc

Now let's modify glibc with:

diff --git a/nptl/thrd_create.c b/nptl/thrd_create.c
index 113ba0d93e..b00f088abb 100644
--- a/nptl/thrd_create.c
+++ b/nptl/thrd_create.c
@@ -16,11 +16,14 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */

+#include <stdio.h>
+
 #include "thrd_priv.h"

 int
 thrd_create (thrd_t *thr, thrd_start_t func, void *arg)
 {
+  puts("hacked");
   _Static_assert (sizeof (thr) == sizeof (pthread_t),
                   "sizeof (thr) != sizeof (pthread_t)");

Then recompile and re-install glibc, and recompile and re-run our program:

cd glibc/build
make -j `nproc`
make -j `nproc` install
./test_glibc.sh

and we see hacked printed a few times as expected.

This further confirms that we actually used the glibc that we compiled and not the host one.

Tested on Ubuntu 18.04.

Setup 2: crosstool-NG pristine setup

This is an alternative to setup 1, and it is the most correct setup I've achieved far: everything is correct as far as I can observe, including the C runtime objects such as crt1.o, crti.o, and crtn.o.

In this setup, we will compile a full dedicated GCC toolchain that uses the glibc that we want.

The only downside to this method is that the build will take longer. But I wouldn't risk a production setup with anything less.

crosstool-NG is a set of scripts that downloads and compiles everything from source for us, including GCC, glibc and binutils.

Yes the GCC build system is so bad that we need a separate project for that.

This setup is only not perfect because crosstool-NG does not support building the executables without extra -Wl flags, which feels weird since we've built GCC itself. But everything seems to work, so this is only an inconvenience.

Get crosstool-NG, configure and build it:

git clone https://github.com/crosstool-ng/crosstool-ng
cd crosstool-ng
git checkout a6580b8e8b55345a5a342b5bd96e42c83e640ac5
export CT_PREFIX="$(pwd)/.build/install"
export PATH="/usr/lib/ccache:${PATH}"
./bootstrap
./configure --enable-local
make -j `nproc`
./ct-ng x86_64-unknown-linux-gnu
./ct-ng menuconfig
env -u LD_LIBRARY_PATH time ./ct-ng build CT_JOBS=`nproc`

The build takes about thirty minutes to two hours.

The only mandatory configuration option that I can see, is making it match your host kernel version to use the correct kernel headers. Find your host kernel version with:

uname -a

which shows me:

4.15.0-34-generic

so in menuconfig I do:

  • Operating System
    • Version of linux

so I select:

4.14.71

which is the first equal or older version. It has to be older since the kernel is backwards compatible.

Setup 2: optional configurations

The .config that we generated with ./ct-ng x86_64-unknown-linux-gnu has:

CT_GLIBC_V_2_27=y

To change that, in menuconfig do:

  • C-library
  • Version of glibc

save the .config, and continue with the build.

Or, if you want to use your own glibc source, e.g. to use glibc from the latest git, proceed like this:

  • Paths and misc options
    • Try features marked as EXPERIMENTAL: set to true
  • C-library
    • Source of glibc
      • Custom location: say yes
      • Custom location
        • Custom source location: point to a directory containing your glibc source

where glibc was cloned as:

git clone git://sourceware.org/git/glibc.git
cd glibc
git checkout glibc-2.28

Setup 2: test it out

Once you have built he toolchain that you want, test it out with:

#!/usr/bin/env bash
set -eux
install_dir="${CT_PREFIX}/x86_64-unknown-linux-gnu"
PATH="${PATH}:${install_dir}/bin" \
  x86_64-unknown-linux-gnu-gcc \
  -Wl,--dynamic-linker="${install_dir}/x86_64-unknown-linux-gnu/sysroot/lib/ld-linux-x86-64.so.2" \
  -Wl,--rpath="${install_dir}/x86_64-unknown-linux-gnu/sysroot/lib" \
  -v \
  -o test_glibc.out \
  test_glibc.c \
  -pthread \
;
ldd test_glibc.out
./test_glibc.out

Everything seems to work as in Setup 1, except that now the correct runtime objects were used:

COLLECT_GCC_OPTIONS=/home/ciro/crosstool-ng/.build/install/x86_64-unknown-linux-gnu/bin/../x86_64-unknown-linux-gnu/sysroot/usr/lib/../lib64/crt1.o

Setup 2: failed efficient glibc recompilation attempt

It does not seem possible with crosstool-NG, as explained below.

If you just re-build;

env -u LD_LIBRARY_PATH time ./ct-ng build CT_JOBS=`nproc`

then your changes to the custom glibc source location are taken into account, but it builds everything from scratch, making it unusable for iterative development.

If we do:

./ct-ng list-steps

it gives a nice overview of the build steps:

Available build steps, in order:
  - companion_tools_for_build
  - companion_libs_for_build
  - binutils_for_build
  - companion_tools_for_host
  - companion_libs_for_host
  - binutils_for_host
  - cc_core_pass_1
  - kernel_headers
  - libc_start_files
  - cc_core_pass_2
  - libc
  - cc_for_build
  - cc_for_host
  - libc_post_cc
  - companion_libs_for_target
  - binutils_for_target
  - debug
  - test_suite
  - finish
Use "<step>" as action to execute only that step.
Use "+<step>" as action to execute up to that step.
Use "<step>+" as action to execute from that step onward.

therefore, we see that there are glibc steps intertwined with several GCC steps, most notably libc_start_files comes before cc_core_pass_2, which is likely the most expensive step together with cc_core_pass_1.

In order to build just one step, you must first set the "Save intermediate steps" in .config option for the intial build:

  • Paths and misc options
    • Debug crosstool-NG
      • Save intermediate steps

and then you can try:

env -u LD_LIBRARY_PATH time ./ct-ng libc+ -j`nproc`

but unfortunately, the + required as mentioned at: https://github.com/crosstool-ng/crosstool-ng/issues/1033#issuecomment-424877536

Note however that restarting at an intermediate step resets the installation directory to the state it had during that step. I.e., you will have a rebuilt libc - but no final compiler built with this libc (and hence, no compiler libraries like libstdc++ either).

and basically still makes the rebuild too slow to be feasible for development, and I don't see how to overcome this without patching crosstool-NG.

Furthermore, starting from the libc step didn't seem to copy over the source again from Custom source location, further making this method unusable.

Bonus: stdlibc++

A bonus if you're also interested in the C++ standard library: How to edit and re-build the GCC libstdc++ C++ standard library source?

How to check if click event is already bound - JQuery

Based on @konrad-garus answer, but using data, since I believe class should be used mostly for styling.

if (!el.data("bound")) {
  el.data("bound", true);
  el.on("event", function(e) { ... });
}

Laravel Eloquent: How to get only certain columns from joined tables

Check out, http://laravel.com/docs/database/eloquent#to-array

You should be able to define which columns you do not want displayed in your api.

#1214 - The used table type doesn't support FULLTEXT indexes

Simply do the following:

  1. Open your .sql file with Notepad or Notepad ++

  2. Find InnoDB and Replace all (around 87) with MyISAM

  3. Save and now you can import your database with out error.

How to append multiple items in one line in Python

No. The method for appending an entire sequence is list.extend().

>>> L = [1, 2]
>>> L.extend((3, 4, 5))
>>> L
[1, 2, 3, 4, 5]

How to request a random row in SQL?

It seems that many of the ideas listed still use ordering

However, if you use a temporary table, you are able to assign a random index (like many of the solutions have suggested), and then grab the first one that is greater than an arbitrary number between 0 and 1.

For example (for DB2):

WITH TEMP AS (
SELECT COMLUMN, RAND() AS IDX FROM TABLE)
SELECT COLUMN FROM TABLE WHERE IDX > .5
FETCH FIRST 1 ROW ONLY

I just discovered why all ASP.Net websites are slow, and I am trying to work out what to do about it

If your page does not modify any session variables, you can opt out of most of this lock.

<% @Page EnableSessionState="ReadOnly" %>

If your page does not read any session variables, you can opt out of this lock entirely, for that page.

<% @Page EnableSessionState="False" %>

If none of your pages use session variables, just turn off session state in the web.config.

<sessionState mode="Off" />

I'm curious, what do you think "a ThreadSafe collection" would do to become thread-safe, if it doesn't use locks?

Edit: I should probably explain by what I mean by "opt out of most of this lock". Any number of read-only-session or no-session pages can be processed for a given session at the same time without blocking each other. However, a read-write-session page can't start processing until all read-only requests have completed, and while it is running it must have exclusive access to that user's session in order to maintain consistency. Locking on individual values wouldn't work, because what if one page changes a set of related values as a group? How would you ensure that other pages running at the same time would get a consistent view of the user's session variables?

I would suggest that you try to minimize the modifying of session variables once they have been set, if possible. This would allow you to make the majority of your pages read-only-session pages, increasing the chance that multiple simultaneous requests from the same user would not block each other.

Remove last character from string. Swift language

complimentary to the above code I wanted to remove the beginning of the string and could not find a reference anywhere. Here is how I did it:

var mac = peripheral.identifier.description
let range = mac.startIndex..<mac.endIndex.advancedBy(-50)
mac.removeRange(range)  // trim 17 characters from the beginning
let txPower = peripheral.advertisements.txPower?.description

This trims 17 characters from the beginning of the string (he total string length is 67 we advance -50 from the end and there you have it.

git checkout master error: the following untracked working tree files would be overwritten by checkout

Try git checkout -f master.

-f or --force

Source: https://www.kernel.org/pub/software/scm/git/docs/git-checkout.html

When switching branches, proceed even if the index or the working tree differs from HEAD. This is used to throw away local changes.

When checking out paths from the index, do not fail upon unmerged entries; instead, unmerged entries are ignored.

Safest way to convert float to integer in python?

Combining two of the previous results, we have:

int(round(some_float))

This converts a float to an integer fairly dependably.

How to avoid precompiled headers

You can always disable the use of pre-compiled headers in the project settings.

Instructions for VS 2010 (should be similar for other versions of VS):

Select your project, use the "Project -> Properties" menu and go to the "Configuration Properties -> C/C++ -> Precompiled Headers" section, then change the "Precompiled Header" setting to "Not Using Precompiled Headers" option.


If you are only trying to setup a minimal Visual Studio project for simple C++ command-line programs (such as those developed in introductory C++ programming classes), you can create an empty C++ project.

What's the difference between REST & RESTful

REST is an architectural pattern for creating web services. A RESTful service is one that implements that pattern.

how to download file in react js

If you are using React Router, use this:

<Link to="/files/myfile.pdf" target="_blank" download>Download</Link>

Where /files/myfile.pdf is inside your public folder.

Fitting a histogram with python

I was a bit puzzled that norm.fit apparently only worked with the expanded list of sampled values. I tried giving it two lists of numbers, or lists of tuples, but it only appeared to flatten everything and threat the input as individual samples. Since I already have a histogram based on millions of samples, I didn't want to expand this if I didn't have to. Thankfully, the normal distribution is trivial to calculate, so...

# histogram is [(val,count)]
from math import sqrt

def normfit(hist):
    n,s,ss = univar(hist)
    mu = s/n
    var = ss/n-mu*mu
    return (mu, sqrt(var))

def univar(hist):
    n = 0
    s = 0
    ss = 0
    for v,c in hist:
        n += c
        s += c*v
        ss += c*v*v
    return n, s, ss

I'm sure this must be provided by the libraries, but as I couldn't find it anywhere, I'm posting this here instead. Feel free to point to the correct way to do it and downvote me :-)

How to uninstall Python 2.7 on a Mac OS X 10.6.4?

No need to uninstall old python versions.

Just install new version say python-3.3.2-macosx10.6.dmg and change the soft link of python to newly installed python3.3

Check the path of default python and python3.3 with following commands

"which python" and "which python3.3"

then delete existing soft link of python and point it to python3.3

Value of type 'T' cannot be converted to

Change this line:

if (typeof(T) == typeof(string))

For this line:

if (t.GetType() == typeof(string))

Linq with group by having count

Like this:

from c in db.Company
group c by c.Name into grp
where grp.Count() > 1
select grp.Key

Or, using the method syntax:

Company
    .GroupBy(c => c.Name)
    .Where(grp => grp.Count() > 1)
    .Select(grp => grp.Key);

Android : Capturing HTTP Requests with non-rooted android device

It's 2020 now, for the latest solution, you can use Burp Suite to sniffing https traffic without rooting your Android device.

Steps:

  1. Install Burp Suite

  2. Enable Proxy

  3. Import the certification in your Android phone

  4. Change you Wifi configuration to listening to proxy

  5. Profit!

I wrote the full tutorial and screenshot on how to do it at here: https://www.yodiw.com/monitor-android-network-traffic-with-burp/

Select all contents of textbox when it receives focus (Vanilla JS or jQuery)

jQuery is not JavaScript which is more easy to use in some cases.

Look at this example:

<textarea rows="10" cols="50" onclick="this.focus();this.select()">Text is here</textarea>

Source: CSS Tricks, MDN

Code for download video from Youtube on Java, Android

Ref : Youtube Video Download (Android/Java)

private static final HashMap<String, Meta> typeMap = new HashMap<String, Meta>();

initTypeMap(); call first

class Meta {
    public String num;
    public String type;
    public String ext;

    Meta(String num, String ext, String type) {
        this.num = num;
        this.ext = ext;
        this.type = type;
    }
}

class Video {
    public String ext = "";
    public String type = "";
    public String url = "";

    Video(String ext, String type, String url) {
        this.ext = ext;
        this.type = type;
        this.url = url;
    }
}

public ArrayList<Video> getStreamingUrisFromYouTubePage(String ytUrl)
        throws IOException {
    if (ytUrl == null) {
        return null;
    }

    // Remove any query params in query string after the watch?v=<vid> in
    // e.g.
    // http://www.youtube.com/watch?v=0RUPACpf8Vs&feature=youtube_gdata_player
    int andIdx = ytUrl.indexOf('&');
    if (andIdx >= 0) {
        ytUrl = ytUrl.substring(0, andIdx);
    }

    // Get the HTML response
    /* String userAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:8.0.1)";*/
   /* HttpClient client = new DefaultHttpClient();
    client.getParams().setParameter(CoreProtocolPNames.USER_AGENT,
            userAgent);
    HttpGet request = new HttpGet(ytUrl);
    HttpResponse response = client.execute(request);*/
    String html = "";
    HttpsURLConnection c = (HttpsURLConnection) new URL(ytUrl).openConnection();
    c.setRequestMethod("GET");
    c.setDoOutput(true);
    c.connect();
    InputStream in = c.getInputStream();
    BufferedReader reader = new BufferedReader(new InputStreamReader(in));
    StringBuilder str = new StringBuilder();
    String line = null;
    while ((line = reader.readLine()) != null) {
        str.append(line.replace("\\u0026", "&"));
    }
    in.close();
    html = str.toString();

    // Parse the HTML response and extract the streaming URIs
    if (html.contains("verify-age-thumb")) {
        Log.e("Downloader", "YouTube is asking for age verification. We can't handle that sorry.");
        return null;
    }

    if (html.contains("das_captcha")) {
        Log.e("Downloader", "Captcha found, please try with different IP address.");
        return null;
    }

    Pattern p = Pattern.compile("stream_map\":\"(.*?)?\"");
    // Pattern p = Pattern.compile("/stream_map=(.[^&]*?)\"/");
    Matcher m = p.matcher(html);
    List<String> matches = new ArrayList<String>();
    while (m.find()) {
        matches.add(m.group());
    }

    if (matches.size() != 1) {
        Log.e("Downloader", "Found zero or too many stream maps.");
        return null;
    }

    String urls[] = matches.get(0).split(",");
    HashMap<String, String> foundArray = new HashMap<String, String>();
    for (String ppUrl : urls) {
        String url = URLDecoder.decode(ppUrl, "UTF-8");
        Log.e("URL","URL : "+url);

        Pattern p1 = Pattern.compile("itag=([0-9]+?)[&]");
        Matcher m1 = p1.matcher(url);
        String itag = null;
        if (m1.find()) {
            itag = m1.group(1);
        }

        Pattern p2 = Pattern.compile("signature=(.*?)[&]");
        Matcher m2 = p2.matcher(url);
        String sig = null;
        if (m2.find()) {
            sig = m2.group(1);
        } else {
            Pattern p23 = Pattern.compile("signature&s=(.*?)[&]");
            Matcher m23 = p23.matcher(url);
            if (m23.find()) {
                sig = m23.group(1);
            }
        }

        Pattern p3 = Pattern.compile("url=(.*?)[&]");
        Matcher m3 = p3.matcher(ppUrl);
        String um = null;
        if (m3.find()) {
            um = m3.group(1);
        }

        if (itag != null && sig != null && um != null) {
            Log.e("foundArray","Adding Value");
            foundArray.put(itag, URLDecoder.decode(um, "UTF-8") + "&"
                    + "signature=" + sig);
        }
    }
    Log.e("foundArray","Size : "+foundArray.size());
    if (foundArray.size() == 0) {
        Log.e("Downloader", "Couldn't find any URLs and corresponding signatures");
        return null;
    }


    ArrayList<Video> videos = new ArrayList<Video>();

    for (String format : typeMap.keySet()) {
        Meta meta = typeMap.get(format);

        if (foundArray.containsKey(format)) {
            Video newVideo = new Video(meta.ext, meta.type,
                    foundArray.get(format));
            videos.add(newVideo);
            Log.d("Downloader", "YouTube Video streaming details: ext:" + newVideo.ext
                    + ", type:" + newVideo.type + ", url:" + newVideo.url);
        }
    }

    return videos;
}

private class YouTubePageStreamUriGetter extends AsyncTask<String, String, ArrayList<Video>> {
    ProgressDialog progressDialog;

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        progressDialog = ProgressDialog.show(webViewActivity.this, "",
                "Connecting to YouTube...", true);
    }

    @Override
    protected ArrayList<Video> doInBackground(String... params) {
        ArrayList<Video> fVideos = new ArrayList<>();
        String url = params[0];
        try {
            ArrayList<Video> videos = getStreamingUrisFromYouTubePage(url);
            /*                Log.e("Downloader","Size of Video : "+videos.size());*/
            if (videos != null && !videos.isEmpty()) {
                for (Video video : videos)
                {
                    Log.e("Downloader", "ext : " + video.ext);
                    if (video.ext.toLowerCase().contains("mp4") || video.ext.toLowerCase().contains("3gp") || video.ext.toLowerCase().contains("flv") || video.ext.toLowerCase().contains("webm")) {
                        ext = video.ext.toLowerCase();
                        fVideos.add(new Video(video.ext,video.type,video.url));
                    }
                }


                return fVideos;
            }
        } catch (Exception e) {
            e.printStackTrace();
            Log.e("Downloader", "Couldn't get YouTube streaming URL", e);
        }
        Log.e("Downloader", "Couldn't get stream URI for " + url);
        return null;
    }

    @Override
    protected void onPostExecute(ArrayList<Video> streamingUrl) {
        super.onPostExecute(streamingUrl);
        progressDialog.dismiss();
        if (streamingUrl != null) {
            if (!streamingUrl.isEmpty()) {
                //Log.e("Steaming Url", "Value : " + streamingUrl);

                for (int i = 0; i < streamingUrl.size(); i++) {
                    Video fX = streamingUrl.get(i);
                    Log.e("Founded Video", "URL : " + fX.url);
                    Log.e("Founded Video", "TYPE : " + fX.type);
                    Log.e("Founded Video", "EXT : " + fX.ext);
                }
                //new ProgressBack().execute(new String[]{streamingUrl, filename + "." + ext});
            }
        }
    }
}
public void initTypeMap()
{
    typeMap.put("13", new Meta("13", "3GP", "Low Quality - 176x144"));
    typeMap.put("17", new Meta("17", "3GP", "Medium Quality - 176x144"));
    typeMap.put("36", new Meta("36", "3GP", "High Quality - 320x240"));
    typeMap.put("5", new Meta("5", "FLV", "Low Quality - 400x226"));
    typeMap.put("6", new Meta("6", "FLV", "Medium Quality - 640x360"));
    typeMap.put("34", new Meta("34", "FLV", "Medium Quality - 640x360"));
    typeMap.put("35", new Meta("35", "FLV", "High Quality - 854x480"));
    typeMap.put("43", new Meta("43", "WEBM", "Low Quality - 640x360"));
    typeMap.put("44", new Meta("44", "WEBM", "Medium Quality - 854x480"));
    typeMap.put("45", new Meta("45", "WEBM", "High Quality - 1280x720"));
    typeMap.put("18", new Meta("18", "MP4", "Medium Quality - 480x360"));
    typeMap.put("22", new Meta("22", "MP4", "High Quality - 1280x720"));
    typeMap.put("37", new Meta("37", "MP4", "High Quality - 1920x1080"));
    typeMap.put("33", new Meta("38", "MP4", "High Quality - 4096x230"));
}

Edit 2:

Some time This Code Not worked proper

Same-origin policy

https://en.wikipedia.org/wiki/Same-origin_policy

https://en.wikipedia.org/wiki/Cross-origin_resource_sharing

problem of Same-origin policy. Essentially, you cannot download this file from www.youtube.com because they are different domains. A workaround of this problem is [CORS][1]. 

Ref : https://superuser.com/questions/773719/how-do-all-of-these-save-video-from-youtube-services-work/773998#773998

url_encoded_fmt_stream_map // traditional: contains video and audio stream
adaptive_fmts              // DASH: contains video or audio stream

Each of these is a comma separated array of what I would call "stream objects". Each "stream object" will contain values like this

url  // direct HTTP link to a video
itag // code specifying the quality
s    // signature, security measure to counter downloading

Each URL will be encoded so you will need to decode them. Now the tricky part.

YouTube has at least 3 security levels for their videos

unsecured // as expected, you can download these with just the unencoded URL
s         // see below
RTMPE     // uses "rtmpe://" protocol, no known method for these

The RTMPE videos are typically used on official full length movies, and are protected with SWF Verification Type 2. This has been around since 2011 and has yet to be reverse engineered.

The type "s" videos are the most difficult that can actually be downloaded. You will typcially see these on VEVO videos and the like. They start with a signature such as

AA5D05FA7771AD4868BA4C977C3DEAAC620DE020E.0F421820F42978A1F8EAFCDAC4EF507DB5 Then the signature is scrambled with a function like this

function mo(a) {
  a = a.split("");
  a = lo.rw(a, 1);
  a = lo.rw(a, 32);
  a = lo.IC(a, 1);
  a = lo.wS(a, 77);
  a = lo.IC(a, 3);
  a = lo.wS(a, 77);
  a = lo.IC(a, 3);
  a = lo.wS(a, 44);
  return a.join("")
}

This function is dynamic, it typically changes every day. To make it more difficult the function is hosted at a URL such as

http://s.ytimg.com/yts/jsbin/html5player-en_US-vflycBCEX.js

this introduces the problem of Same-origin policy. Essentially, you cannot download this file from www.youtube.com because they are different domains. A workaround of this problem is CORS. With CORS, s.ytimg.com could add this header

Access-Control-Allow-Origin: http://www.youtube.com

and it would allow the JavaScript to download from www.youtube.com. Of course they do not do this. A workaround for this workaround is to use a CORS proxy. This is a proxy that responds with the following header to all requests

Access-Control-Allow-Origin: *

So, now that you have proxied your JS file, and used the function to scramble the signature, you can use that in the querystring to download a video.

Is there a TRY CATCH command in Bash

You can use trap:

try { block A } catch { block B } finally { block C }

translates to:

(
  set -Ee
  function _catch {
    block B
    exit 0  # optional; use if you don't want to propagate (rethrow) error to outer shell
  }
  function _finally {
    block C
  }
  trap _catch ERR
  trap _finally EXIT
  block A
)

How do I call a Django function on button click?

here is a pure-javascript, minimalistic approach. I use JQuery but you can use any library (or even no libraries at all).

<html>
    <head>
        <title>An example</title>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
        <script>
            function call_counter(url, pk) {
                window.open(url);
                $.get('YOUR_VIEW_HERE/'+pk+'/', function (data) {
                    alert("counter updated!");
                });
            }
        </script>
    </head>
    <body>
        <button onclick="call_counter('http://www.google.com', 12345);">
            I update object 12345
        </button>
        <button onclick="call_counter('http://www.yahoo.com', 999);">
            I update object 999
        </button>
    </body>
</html>

Alternative approach

Instead of placing the JavaScript code, you can change your link in this way:

<a target="_blank" 
    class="btn btn-info pull-right" 
    href="{% url YOUR_VIEW column_3_item.pk %}/?next={{column_3_item.link_for_item|urlencode:''}}">
    Check It Out
</a>

and in your views.py:

def YOUR_VIEW_DEF(request, pk):
    YOUR_OBJECT.objects.filter(pk=pk).update(views=F('views')+1)
    return HttpResponseRedirect(request.GET.get('next')))

Can "list_display" in a Django ModelAdmin display attributes of ForeignKey fields?

According to the documentation, you can only display the __unicode__ representation of a ForeignKey:

http://docs.djangoproject.com/en/dev/ref/contrib/admin/#list-display

Seems odd that it doesn't support the 'book__author' style format which is used everywhere else in the DB API.

Turns out there's a ticket for this feature, which is marked as Won't Fix.

The simplest way to comma-delimit a list?

I somewhat like this approach, which I found on a blog some time ago. Unfortunately I don't remember the blog's name/URL.

You can create a utility/helper class that looks like this:

private class Delimiter
{
    private final String delimiter;
    private boolean first = true;

    public Delimiter(String delimiter)
    {
        this.delimiter = delimiter;
    }

    @Override
    public String toString()
    {
        if (first) {
            first = false;
            return "";
        }

        return delimiter;
    }
}

Using the helper class is simple as this:

StringBuilder sb = new StringBuilder();
Delimiter delimiter = new Delimiter(", ");

for (String item : list) {
    sb.append(delimiter);
    sb.append(item);
}

CodeIgniter: How to use WHERE clause and OR clause

Active record method or_where is to be used:

$this->db->select("*")
->from("table_name")
->where("first", $first)
->or_where("second", $second);

String to Binary in C#

The following will give you the hex encoding for the low byte of each character, which looks like what you're asking for:

StringBuilder sb = new StringBuilder();
foreach (char c in asciiString)
{
    uint i = (uint)c;
    sb.AppendFormat("{0:X2}", (i & 0xff));
}
return sb.ToString();

SQL Server Group by Count of DateTime Per Hour?

I found this somewhere else. I like this answer!

SELECT [Hourly], COUNT(*) as [Count]
  FROM 
 (SELECT dateadd(hh, datediff(hh, '20010101', [date_created]), '20010101') as [Hourly]
    FROM table) idat
 GROUP BY [Hourly]

Early exit from function?

if you are looking for a script to avoid submitting form when some errors found, this method should work

function verifyData(){
     if (document.MyForm.FormInput.value.length == "") {
          alert("Write something!");
     }
     else {
          document.MyForm.submit();
     }
}

change the Submit Button type to "button"

<input value="Save" type="button" onClick="verifyData()">

hope this help.

How do I move a file (or folder) from one folder to another in TortoiseSVN?

Subversion does not yet have a first-class rename operations.

There's a 6-year-old bug on the problem: http://subversion.tigris.org/issues/show_bug.cgi?id=898

It's being considered for 1.6, now that merge tracking (a higher priority) has been added (in 1.5).

.ps1 cannot be loaded because the execution of scripts is disabled on this system

I had a similar issue and noted that the default cmd on Windows Server 2012 was running the x64 one.

For Windows 7, Windows 8, Windows Server 2008 R2 or Windows Server 2012, run the following commands as Administrator:

x86

Open C:\Windows\SysWOW64\cmd.exe Run the command: powershell Set-ExecutionPolicy RemoteSigned

x64

Open C:\Windows\system32\cmd.exe Run the command powershell Set-ExecutionPolicy RemoteSigned

You can check mode using

In CMD: echo %PROCESSOR_ARCHITECTURE% In Powershell: [Environment]::Is64BitProcess

I hope this help you.

Resizing an iframe based on content

We had this type of problem, but slightly in reverse to your situation - we were providing the iframed content to sites on other domains, so the same origin policy was also an issue. After many hours spent trawling google, we eventually found a (somewhat..) workable solution, which you may be able to adapt to your needs.

There is a way around the same origin policy, but it requires changes on both the iframed content and the framing page, so if you haven't the ability to request changes on both sides, this method won't be very useful to you, i'm afraid.

There's a browser quirk which allows us to skirt the same origin policy - javascript can communicate either with pages on its own domain, or with pages it has iframed, but never pages in which it is framed, e.g. if you have:

 www.foo.com/home.html, which iframes
 |-> www.bar.net/framed.html, which iframes
     |-> www.foo.com/helper.html

then home.html can communicate with framed.html (iframed) and helper.html (same domain).

 Communication options for each page:
 +-------------------------+-----------+-------------+-------------+
 |                         | home.html | framed.html | helper.html |
 +-------------------------+-----------+-------------+-------------+
 | www.foo.com/home.html   |    N/A    |     YES     |     YES     |
 | www.bar.net/framed.html |    NO     |     N/A     |     YES     |
 | www.foo.com/helper.html |    YES    |     YES     |     N/A     |
 +-------------------------+-----------+-------------+-------------+

framed.html can send messages to helper.html (iframed) but not home.html (child can't communicate cross-domain with parent).

The key here is that helper.html can receive messages from framed.html, and can also communicate with home.html.

So essentially, when framed.html loads, it works out its own height, tells helper.html, which passes the message on to home.html, which can then resize the iframe in which framed.html sits.

The simplest way we found to pass messages from framed.html to helper.html was through a URL argument. To do this, framed.html has an iframe with src='' specified. When its onload fires, it evaluates its own height, and sets the src of the iframe at this point to helper.html?height=N

There's an explanation here of how facebook handle it, which may be slightly clearer than mine above!


Code

In www.foo.com/home.html, the following javascript code is required (this can be loaded from a .js file on any domain, incidentally..):

<script>
  // Resize iframe to full height
  function resizeIframe(height)
  {
    // "+60" is a general rule of thumb to allow for differences in
    // IE & and FF height reporting, can be adjusted as required..
    document.getElementById('frame_name_here').height = parseInt(height)+60;
  }
</script>
<iframe id='frame_name_here' src='http://www.bar.net/framed.html'></iframe>

In www.bar.net/framed.html:

<body onload="iframeResizePipe()">
<iframe id="helpframe" src='' height='0' width='0' frameborder='0'></iframe>

<script type="text/javascript">
  function iframeResizePipe()
  {
     // What's the page height?
     var height = document.body.scrollHeight;

     // Going to 'pipe' the data to the parent through the helpframe..
     var pipe = document.getElementById('helpframe');

     // Cachebuster a precaution here to stop browser caching interfering
     pipe.src = 'http://www.foo.com/helper.html?height='+height+'&cacheb='+Math.random();

  }
</script>

Contents of www.foo.com/helper.html:

<html> 
<!-- 
This page is on the same domain as the parent, so can
communicate with it to order the iframe window resizing
to fit the content 
--> 
  <body onload="parentIframeResize()"> 
    <script> 
      // Tell the parent iframe what height the iframe needs to be
      function parentIframeResize()
      {
         var height = getParam('height');
         // This works as our parent's parent is on our domain..
         parent.parent.resizeIframe(height);
      }

      // Helper function, parse param from request string
      function getParam( name )
      {
        name = name.replace(/[\[]/,"\\\[").replace(/[\]]/,"\\\]");
        var regexS = "[\\?&]"+name+"=([^&#]*)";
        var regex = new RegExp( regexS );
        var results = regex.exec( window.location.href );
        if( results == null )
          return "";
        else
          return results[1];
      }
    </script> 
  </body> 
</html>

How to save/restore serializable object to/from file?

1. Restore Object From File

From Here you can deserialize an object from file in two way.

Solution-1: Read file into a string and deserialize JSON to a type

string json = File.ReadAllText(@"c:\myObj.json");
MyObject myObj = JsonConvert.DeserializeObject<MyObject>(json);

Solution-2: Deserialize JSON directly from a file

using (StreamReader file = File.OpenText(@"c:\myObj.json"))
{
    JsonSerializer serializer = new JsonSerializer();
    MyObject myObj2 = (MyObject)serializer.Deserialize(file, typeof(MyObject));
}

2. Save Object To File

from here you can serialize an object to file in two way.

Solution-1: Serialize JSON to a string and then write string to a file

string json = JsonConvert.SerializeObject(myObj);
File.WriteAllText(@"c:\myObj.json", json);

Solution-2: Serialize JSON directly to a file

using (StreamWriter file = File.CreateText(@"c:\myObj.json"))
{
    JsonSerializer serializer = new JsonSerializer();
    serializer.Serialize(file, myObj);
}

3. Extra

You can download Newtonsoft.Json from NuGet by following command

Install-Package Newtonsoft.Json

How to create file execute mode permissions in Git on Windows?

The note is firstly you must sure about filemode set to false in config git file, or use this command:

git config core.filemode false

and then you can set 0777 permission with this command:

git update-index --chmod=+x foo.sh

What is the Auto-Alignment Shortcut Key in Eclipse?

The answer that the OP accepted is wildly different from the question I thought was asked. I thought the OP wanted a way to auto-align = signs or + signs, similar to the tabularize plugin for vim.

For this task, I found the Columns4Eclipse plugin to be just what I needed.

Return string without trailing slash

Here a small url example.

var currentUrl = location.href;

if(currentUrl.substr(-1) == '/') {
    currentUrl = currentUrl.substr(0, currentUrl.length - 1);
}

log the new url

console.log(currentUrl);

Fit Image in ImageButton in Android

You can make your ImageButton widget as I did. In my case, I needed a widget with a fixed icon size. Let's start from custom attributes:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="ImageButtonFixedIconSize">
        <attr name="imageButton_icon" format="reference" />
        <attr name="imageButton_iconWidth" format="dimension" />
        <attr name="imageButton_iconHeight" format="dimension" />
    </declare-styleable>
</resources>

Widget class is quite simple (the key point is padding calculations in onLayout method):

class ImageButtonFixedIconSize
@JvmOverloads
constructor(
    context: Context,
    attrs: AttributeSet? = null,
    defStyleAttr: Int = android.R.attr.imageButtonStyle
) : ImageButton(context, attrs, defStyleAttr) {

    private lateinit var icon: Drawable

    @Px
    private var iconWidth: Int = 0
    @Px
    private var iconHeight: Int = 0

    init {
        scaleType = ScaleType.FIT_XY
        attrs?.let { retrieveAttributes(it) }
    }

    /**
     *
     */
    override fun onLayout(changed: Boolean, left: Int, top: Int, right: Int, bottom: Int) {
        val width = right - left
        val height = bottom - top

        val horizontalPadding = if(width > iconWidth) (width - iconWidth) / 2 else 0
        val verticalPadding = if(height > iconHeight) (height - iconHeight) / 2 else 0

        setPadding(horizontalPadding, verticalPadding, horizontalPadding, verticalPadding)

        setImageDrawable(icon)

        super.onLayout(changed, left, top, right, bottom)
    }

    /**
     *
     */
    private fun retrieveAttributes(attrs: AttributeSet) {
        val typedArray = context.obtainStyledAttributes(attrs, R.styleable.ImageButtonFixedIconSize)

        icon = typedArray.getDrawable(R.styleable.ImageButtonFixedIconSize_imageButton_icon)!!

        iconWidth = typedArray.getDimension(R.styleable.ImageButtonFixedIconSize_imageButton_iconWidth, 0f).toInt()
        iconHeight = typedArray.getDimension(R.styleable.ImageButtonFixedIconSize_imageButton_iconHeight, 0f).toInt()

        typedArray.recycle()
    }
}

And at last you should use your widget like this:

<com.syleiman.gingermoney.ui.common.controls.ImageButtonFixedIconSize
    android:layout_width="90dp"
    android:layout_height="63dp"

    app:imageButton_icon="@drawable/ic_backspace"
    app:imageButton_iconWidth="20dp"
    app:imageButton_iconHeight="15dp"

    android:id="@+id/backspaceButton"
    tools:ignore="ContentDescription"
    />

XPath: select text node

your xpath should work . i have tested your xpath and mine in both MarkLogic and Zorba Xquery/ Xpath implementation.

Both should work.

/node/child::text()[1] - should return Text1
/node/child::text()[2] - should return text2


/node/text()[1] - should return Text1
/node/text()[2] - should return text2

How to check if variable is array?... or something array-like

Functions

<?php

/**
 * Is Array?
 * @param mixed $x
 * @return bool
 */
function isArray($x) : bool {
  return !isAssociative($x);
}

/**
 * Is Associative Array?
 * @param mixed $x
 * @return bool
 */
function isAssociative($x) : bool {
  if (!is_array($array)) {
    return false;
  }
  $i = count($array);
  while ($i > 0) {
    if (!isset($array[--$i])) {
      return true;
    }
  }
  return false;
}

Example

<?php

$arr = [ 'foo', 'bar' ];
$obj = [ 'foo' => 'bar' ];

var_dump(isAssociative($arr));
# bool(false)

var_dump(isAssociative($obj));
# bool(true)

var_dump(isArray($obj));
# bool(false)

var_dump(isArray($arr));
# bool(true)

How to create a function in SQL Server

This one get everything between the "." characters. Please note this won't work for more complex URLs like "www.somesite.co.uk" Ideally the function would check for how many instances of the "." character and choose the substring accordingly.

CREATE FUNCTION dbo.GetURL (@URL VARCHAR(250))
RETURNS VARCHAR(250)
AS BEGIN
    DECLARE @Work VARCHAR(250)

    SET @Work = @URL

    SET @Work = SUBSTRING(@work, CHARINDEX('.', @work) + 1, LEN(@work))   
    SET @Work = SUBSTRING(@work, 0, CHARINDEX('.', @work))

    --Alternate:
    --SET @Work = SUBSTRING(@work, CHARINDEX('.', @work) + 1, CHARINDEX('.', @work) + 1)   

    RETURN @work
END

Is it possible to change the package name of an Android app on Google Play?

No, you cannot change package name unless you're okay with publishing it as a new app in Play Store:

Once you publish your application under its manifest package name, this is the unique identity of the application forever more. Switching to a different name results in an entirely new application, one that can’t be installed as an update to the existing application. Android manual confirms it as well here:

Caution: Once you publish your application, you cannot change the package name. The package name defines your application's identity, so if you change it, then it is considered to be a different application and users of the previous version cannot update to the new version. If you're okay with publishing new version of your app as a completely new entity, you can do it of course - just remove old app from Play Store (if you want) and publish new one, with different package name.

How to initialize a two-dimensional array in Python?

Matrix={}
for i in range(0,3):
  for j in range(0,3):
    Matrix[i,j] = raw_input("Enter the matrix:")

Parse JSON from HttpURLConnection object

The JSON string will just be the body of the response you get back from the URL you have called. So add this code

...
BufferedReader in = new BufferedReader(new InputStreamReader(
                            conn.getInputStream()));
String inputLine;
while ((inputLine = in.readLine()) != null) 
    System.out.println(inputLine);
in.close();

That will allow you to see the JSON being returned to the console. The only missing piece you then have is using a JSON library to read that data and provide you with a Java representation.

Here's an example using JSON-LIB

MomentJS getting JavaScript Date in UTC

Calling toDate will create a copy (the documentation is down-right wrong about it not being a copy), of the underlying JS Date object. JS Date object is stored in UTC and will always print to eastern time. Without getting into whether .utc() modifies the underlying object that moment wraps use the code below.

You don't need moment for this.

new Date().getTime()

This works, because JS Date at its core is in UTC from the Unix Epoch. It's extraordinarily confusing and I believe a big flaw in the interface to mix local and UTC times like this with no descriptions in the methods.

How to select rows with one or more nulls from a pandas DataFrame without listing columns explicitly?

If you want to filter rows by a certain number of columns with null values, you may use this:

df.iloc[df[(df.isnull().sum(axis=1) >= qty_of_nuls)].index]

So, here is the example:

Your dataframe:

>>> df = pd.DataFrame([range(4), [0, np.NaN, 0, np.NaN], [0, 0, np.NaN, 0], range(4), [np.NaN, 0, np.NaN, np.NaN]])
>>> df
     0    1    2    3
0  0.0  1.0  2.0  3.0
1  0.0  NaN  0.0  NaN
2  0.0  0.0  NaN  0.0
3  0.0  1.0  2.0  3.0
4  NaN  0.0  NaN  NaN

If you want to select the rows that have two or more columns with null value, you run the following:

>>> qty_of_nuls = 2
>>> df.iloc[df[(df.isnull().sum(axis=1) >=qty_of_nuls)].index]
     0    1    2   3
1  0.0  NaN  0.0 NaN
4  NaN  0.0  NaN NaN

How do you divide each element in a list by an int?

>>> myList = [10,20,30,40,50,60,70,80,90]
>>> myInt = 10
>>> newList = map(lambda x: x/myInt, myList)
>>> newList
[1, 2, 3, 4, 5, 6, 7, 8, 9]

How to import cv2 in python3?

well, there was 2 issues: 1.instead of pip, pip3 should be used. 2.its better to use virtual env. because i have had multiple python version installed

How can I bind a background color in WPF/XAML?

Here you've got a copy-paste code:

class NameToBackgroundConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if(value.ToString() == "System")
            {
                return new SolidColorBrush(System.Windows.Media.Colors.Aqua);
            }else
            {
                return new SolidColorBrush(System.Windows.Media.Colors.Blue);
            }
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return null;
        }
    }

Cannot push to Git repository on Bitbucket

If you are using SourceTree (I'm using 2.4.1), I found a simpler way to generate an SSH key and add it to my Bitbucket settings. This solved the problem for me.

  1. In SourceTree, go to Preferences.
  2. Go to the Accounts tab and select your account.
  3. There should be an option to generate and copy an SSH key to clipboard.
  4. Once you have copied that, go to Bitbucket in your browser. Go to [avatar] -> Bitbucket settings.
  5. Go to SSH keys.
  6. Click Add key
  7. Paste in the key you copied.

I received a confirmation email from Bitbucket that an SSH key had been added to my account.

For reference, on macOS, using Terminal, you can use the following command to see the keys generated for your device. This is where the key you generated is stored.

ls -la ~/.ssh

As others have stated, this documentation helped me: Use the SSH protocol with Bitbucket Cloud

Adding items to a JComboBox

You can use any Object as an item. In that object you can have several fields you need. In your case the value field. You have to override the toString() method to represent the text. In your case "item text". See the example:

public class AnyObject {

    private String value;
    private String text;

    public AnyObject(String value, String text) {
        this.value = value;
        this.text = text;
    }

...

    @Override
    public String toString() {
        return text;
    }
}

comboBox.addItem(new AnyObject("item_value", "item text"));

git pull displays "fatal: Couldn't find remote ref refs/heads/xxxx" and hangs up

There are probably some commands to resolve it, but I would start by looking in your .git/config file for references to that branch, and removing them.

Restricting JTextField input to Integers

Here's one approach that uses a keylistener,but uses the keyChar (instead of the keyCode):

http://edenti.deis.unibo.it/utils/Java-tips/Validating%20numerical%20input%20in%20a%20JTextField.txt

 keyText.addKeyListener(new KeyAdapter() {
    public void keyTyped(KeyEvent e) {
      char c = e.getKeyChar();
      if (!((c >= '0') && (c <= '9') ||
         (c == KeyEvent.VK_BACK_SPACE) ||
         (c == KeyEvent.VK_DELETE))) {
        getToolkit().beep();
        e.consume();
      }
    }
  });

Another approach (which personally I find almost as over-complicated as Swing's JTree model) is to use Formatted Text Fields:

http://docs.oracle.com/javase/tutorial/uiswing/components/formattedtextfield.html

Chrome, Javascript, window.open in new tab

You can use this code to open in new tab..

function openWindow( url )
{
  window.open(url, '_blank');
  window.focus();
}

I got it from stackoverflow..

Python equivalent of a given wget command

There is also a nice Python module named wget that is pretty easy to use. Found here.

This demonstrates the simplicity of the design:

>>> import wget
>>> url = 'http://www.futurecrew.com/skaven/song_files/mp3/razorback.mp3'
>>> filename = wget.download(url)
100% [................................................] 3841532 / 3841532>
>> filename
'razorback.mp3'

Enjoy.

However, if wget doesn't work (I've had trouble with certain PDF files), try this solution.

Edit: You can also use the out parameter to use a custom output directory instead of current working directory.

>>> output_directory = <directory_name>
>>> filename = wget.download(url, out=output_directory)
>>> filename
'razorback.mp3'

How to skip a iteration/loop in while-loop

Try to add continue; where you want to skip 1 iteration.

Unlike the break keyword, continue does not terminate a loop. Rather, it skips to the next iteration of the loop, and stops executing any further statements in this iteration. This allows us to bypass the rest of the statements in the current sequence, without stopping the next iteration through the loop.

http://www.javacoffeebreak.com/articles/loopyjava/index.html

How to change progress bar's progress color in Android

This is not programmatically but I think it could help a lot of people anyway.
I tried a lot and the most efficient way was to add this lines to my ProgressBar in the .xml File:

            android:indeterminate="true"
            android:indeterminateTintMode="src_atop"
            android:indeterminateTint="@color/secondary"

So in the end this code did it for me:

<ProgressBar
            android:id="@+id/progressBar"
            style="?android:attr/progressBarStyleLarge"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerHorizontal="true"
            android:layout_centerVertical="true"
            android:layout_marginTop="50dp"
            android:layout_marginBottom="50dp"
            android:visibility="visible"
            android:indeterminate="true"
            android:indeterminateTintMode="src_atop"
            android:indeterminateTint="@color/secondary">

This solution works for API 21+

Understanding __get__ and __set__ and Python descriptors

I am trying to understand what Python's descriptors are and what they can be useful for.

Descriptors are class attributes (like properties or methods) with any of the following special methods:

  • __get__ (non-data descriptor method, for example on a method/function)
  • __set__ (data descriptor method, for example on a property instance)
  • __delete__ (data descriptor method)

These descriptor objects can be used as attributes on other object class definitions. (That is, they live in the __dict__ of the class object.)

Descriptor objects can be used to programmatically manage the results of a dotted lookup (e.g. foo.descriptor) in a normal expression, an assignment, and even a deletion.

Functions/methods, bound methods, property, classmethod, and staticmethod all use these special methods to control how they are accessed via the dotted lookup.

A data descriptor, like property, can allow for lazy evaluation of attributes based on a simpler state of the object, allowing instances to use less memory than if you precomputed each possible attribute.

Another data descriptor, a member_descriptor, created by __slots__, allow memory savings by allowing the class to store data in a mutable tuple-like datastructure instead of the more flexible but space-consuming __dict__.

Non-data descriptors, usually instance, class, and static methods, get their implicit first arguments (usually named cls and self, respectively) from their non-data descriptor method, __get__.

Most users of Python need to learn only the simple usage, and have no need to learn or understand the implementation of descriptors further.

In Depth: What Are Descriptors?

A descriptor is an object with any of the following methods (__get__, __set__, or __delete__), intended to be used via dotted-lookup as if it were a typical attribute of an instance. For an owner-object, obj_instance, with a descriptor object:

  • obj_instance.descriptor invokes
    descriptor.__get__(self, obj_instance, owner_class) returning a value
    This is how all methods and the get on a property work.

  • obj_instance.descriptor = value invokes
    descriptor.__set__(self, obj_instance, value) returning None
    This is how the setter on a property works.

  • del obj_instance.descriptor invokes
    descriptor.__delete__(self, obj_instance) returning None
    This is how the deleter on a property works.

obj_instance is the instance whose class contains the descriptor object's instance. self is the instance of the descriptor (probably just one for the class of the obj_instance)

To define this with code, an object is a descriptor if the set of its attributes intersects with any of the required attributes:

def has_descriptor_attrs(obj):
    return set(['__get__', '__set__', '__delete__']).intersection(dir(obj))

def is_descriptor(obj):
    """obj can be instance of descriptor or the descriptor class"""
    return bool(has_descriptor_attrs(obj))

A Data Descriptor has a __set__ and/or __delete__.
A Non-Data-Descriptor has neither __set__ nor __delete__.

def has_data_descriptor_attrs(obj):
    return set(['__set__', '__delete__']) & set(dir(obj))

def is_data_descriptor(obj):
    return bool(has_data_descriptor_attrs(obj))

Builtin Descriptor Object Examples:

  • classmethod
  • staticmethod
  • property
  • functions in general

Non-Data Descriptors

We can see that classmethod and staticmethod are Non-Data-Descriptors:

>>> is_descriptor(classmethod), is_data_descriptor(classmethod)
(True, False)
>>> is_descriptor(staticmethod), is_data_descriptor(staticmethod)
(True, False)

Both only have the __get__ method:

>>> has_descriptor_attrs(classmethod), has_descriptor_attrs(staticmethod)
(set(['__get__']), set(['__get__']))

Note that all functions are also Non-Data-Descriptors:

>>> def foo(): pass
... 
>>> is_descriptor(foo), is_data_descriptor(foo)
(True, False)

Data Descriptor, property

However, property is a Data-Descriptor:

>>> is_data_descriptor(property)
True
>>> has_descriptor_attrs(property)
set(['__set__', '__get__', '__delete__'])

Dotted Lookup Order

These are important distinctions, as they affect the lookup order for a dotted lookup.

obj_instance.attribute
  1. First the above looks to see if the attribute is a Data-Descriptor on the class of the instance,
  2. If not, it looks to see if the attribute is in the obj_instance's __dict__, then
  3. it finally falls back to a Non-Data-Descriptor.

The consequence of this lookup order is that Non-Data-Descriptors like functions/methods can be overridden by instances.

Recap and Next Steps

We have learned that descriptors are objects with any of __get__, __set__, or __delete__. These descriptor objects can be used as attributes on other object class definitions. Now we will look at how they are used, using your code as an example.


Analysis of Code from the Question

Here's your code, followed by your questions and answers to each:

class Celsius(object):
    def __init__(self, value=0.0):
        self.value = float(value)
    def __get__(self, instance, owner):
        return self.value
    def __set__(self, instance, value):
        self.value = float(value)

class Temperature(object):
    celsius = Celsius()
  1. Why do I need the descriptor class?

Your descriptor ensures you always have a float for this class attribute of Temperature, and that you can't use del to delete the attribute:

>>> t1 = Temperature()
>>> del t1.celsius
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: __delete__

Otherwise, your descriptors ignore the owner-class and instances of the owner, instead, storing state in the descriptor. You could just as easily share state across all instances with a simple class attribute (so long as you always set it as a float to the class and never delete it, or are comfortable with users of your code doing so):

class Temperature(object):
    celsius = 0.0

This gets you exactly the same behavior as your example (see response to question 3 below), but uses a Pythons builtin (property), and would be considered more idiomatic:

class Temperature(object):
    _celsius = 0.0
    @property
    def celsius(self):
        return type(self)._celsius
    @celsius.setter
    def celsius(self, value):
        type(self)._celsius = float(value)
  1. What is instance and owner here? (in get). What is the purpose of these parameters?

instance is the instance of the owner that is calling the descriptor. The owner is the class in which the descriptor object is used to manage access to the data point. See the descriptions of the special methods that define descriptors next to the first paragraph of this answer for more descriptive variable names.

  1. How would I call/use this example?

Here's a demonstration:

>>> t1 = Temperature()
>>> t1.celsius
0.0
>>> t1.celsius = 1
>>> 
>>> t1.celsius
1.0
>>> t2 = Temperature()
>>> t2.celsius
1.0

You can't delete the attribute:

>>> del t2.celsius
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: __delete__

And you can't assign a variable that can't be converted to a float:

>>> t1.celsius = '0x02'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 7, in __set__
ValueError: invalid literal for float(): 0x02

Otherwise, what you have here is a global state for all instances, that is managed by assigning to any instance.

The expected way that most experienced Python programmers would accomplish this outcome would be to use the property decorator, which makes use of the same descriptors under the hood, but brings the behavior into the implementation of the owner class (again, as defined above):

class Temperature(object):
    _celsius = 0.0
    @property
    def celsius(self):
        return type(self)._celsius
    @celsius.setter
    def celsius(self, value):
        type(self)._celsius = float(value)

Which has the exact same expected behavior of the original piece of code:

>>> t1 = Temperature()
>>> t2 = Temperature()
>>> t1.celsius
0.0
>>> t1.celsius = 1.0
>>> t2.celsius
1.0
>>> del t1.celsius
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: can't delete attribute
>>> t1.celsius = '0x02'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 8, in celsius
ValueError: invalid literal for float(): 0x02

Conclusion

We've covered the attributes that define descriptors, the difference between data- and non-data-descriptors, builtin objects that use them, and specific questions about use.

So again, how would you use the question's example? I hope you wouldn't. I hope you would start with my first suggestion (a simple class attribute) and move on to the second suggestion (the property decorator) if you feel it is necessary.

How to make Toolbar transparent?

Checking Google's example Source Code I found out how to make the toolbar completely transparent. It was simpler than I thought. We just have to create a simple Shape drawable like this.

The name of the drawable is toolbar_bg

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" >
<gradient
    android:angle="90"
    android:startColor="@android:color/transparent"
    android:endColor="@android:color/transparent"
    android:type="linear" />
</shape>

And then in the fragment or activity.. Add the toolbar like this.

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:background="@drawable/toolbar_bg"
        android:popupTheme="@style/ThemeOverlay.AppCompat.Light"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"/>

And here we will have a fully transparent toolbar.

enter image description here

Don't add the <android.support.design.widget.AppBarLayout > if you do, this won't work.

Note: If you need the AppBarLayout, set the elevation to 0 so it doesn't draw its shadow.

Ping a site in Python?

read a file name, the file contain the one url per line, like this:

http://www.poolsaboveground.com/apache/hadoop/core/
http://mirrors.sonic.net/apache/hadoop/core/

use command:

python url.py urls.txt

get the result:

Round Trip Time: 253 ms - mirrors.sonic.net
Round Trip Time: 245 ms - www.globalish.com
Round Trip Time: 327 ms - www.poolsaboveground.com

source code(url.py):

import re
import sys
import urlparse
from subprocess import Popen, PIPE
from threading import Thread


class Pinger(object):
    def __init__(self, hosts):
        for host in hosts:
            hostname = urlparse.urlparse(host).hostname
            if hostname:
                pa = PingAgent(hostname)
                pa.start()
            else:
                continue

class PingAgent(Thread):
    def __init__(self, host):
        Thread.__init__(self)        
        self.host = host

    def run(self):
        p = Popen('ping -n 1 ' + self.host, stdout=PIPE)
        m = re.search('Average = (.*)ms', p.stdout.read())
        if m: print 'Round Trip Time: %s ms -' % m.group(1), self.host
        else: print 'Error: Invalid Response -', self.host


if __name__ == '__main__':
    with open(sys.argv[1]) as f:
        content = f.readlines() 
    Pinger(content)

Adding calculated column(s) to a dataframe in pandas

The first four functions you list will work on vectors as well, with the exception that lower_wick needs to be adapted. Something like this,

def lower_wick_vec(o, l, c):
    min_oc = numpy.where(o > c, c, o)
    return min_oc - l

where o, l and c are vectors. You could do it this way instead which just takes the df as input and avoid using numpy, although it will be much slower:

def lower_wick_df(df):
    min_oc = df[['Open', 'Close']].min(axis=1)
    return min_oc - l

The other three will work on columns or vectors just as they are. Then you can finish off with

def is_hammer(df):
    lw = lower_wick_at_least_twice_real_body(df["Open"], df["Low"], df["Close"]) 
    cl = closed_in_top_half_of_range(df["High"], df["Low"], df["Close"])
    return cl & lw

Bit operators can perform set logic on boolean vectors, & for and, | for or etc. This is enough to completely vectorize the sample calculations you gave and should be relatively fast. You could probably speed up even more by temporarily working with the numpy arrays underlying the data while performing these calculations.

For the second part, I would recommend introducing a column indicating the pattern for each row and writing a family of functions which deal with each pattern. Then groupby the pattern and apply the appropriate function to each group.

Variable not accessible when initialized outside function

A global variable would be best expressed in an external JavaScript file:

var system_status;

Make sure that this has not been used anywhere else. Then to access the variable on your page, just reference it as such. Say, for example, you wanted to fill in the results on a textbox,

document.getElementById("textbox1").value = system_status;

To ensure that the object exists, use the document ready feature of jQuery.

Example:

$(function() {
    $("#textbox1")[0].value = system_status;
});

Javascript: Load an Image from url and display

Are you after something like this:

 <html>
 <head>
    <title>Z Test</title>
 </head>
 <body>

<div id="img_home"></div>

<button onclick="addimage()" type="button">Add an image</button>

<script>
function addimage() {
    var img = new Image();
    img.src = "https://www.google.com/images/srpr/logo4w.png"
    img_home.appendChild(img);
}
</script>
</body>

application/x-www-form-urlencoded or multipart/form-data?

TL;DR

Summary; if you have binary (non-alphanumeric) data (or a significantly sized payload) to transmit, use multipart/form-data. Otherwise, use application/x-www-form-urlencoded.


The MIME types you mention are the two Content-Type headers for HTTP POST requests that user-agents (browsers) must support. The purpose of both of those types of requests is to send a list of name/value pairs to the server. Depending on the type and amount of data being transmitted, one of the methods will be more efficient than the other. To understand why, you have to look at what each is doing under the covers.

For application/x-www-form-urlencoded, the body of the HTTP message sent to the server is essentially one giant query string -- name/value pairs are separated by the ampersand (&), and names are separated from values by the equals symbol (=). An example of this would be: 

MyVariableOne=ValueOne&MyVariableTwo=ValueTwo

According to the specification:

[Reserved and] non-alphanumeric characters are replaced by `%HH', a percent sign and two hexadecimal digits representing the ASCII code of the character

That means that for each non-alphanumeric byte that exists in one of our values, it's going to take three bytes to represent it. For large binary files, tripling the payload is going to be highly inefficient.

That's where multipart/form-data comes in. With this method of transmitting name/value pairs, each pair is represented as a "part" in a MIME message (as described by other answers). Parts are separated by a particular string boundary (chosen specifically so that this boundary string does not occur in any of the "value" payloads). Each part has its own set of MIME headers like Content-Type, and particularly Content-Disposition, which can give each part its "name." The value piece of each name/value pair is the payload of each part of the MIME message. The MIME spec gives us more options when representing the value payload -- we can choose a more efficient encoding of binary data to save bandwidth (e.g. base 64 or even raw binary).

Why not use multipart/form-data all the time? For short alphanumeric values (like most web forms), the overhead of adding all of the MIME headers is going to significantly outweigh any savings from more efficient binary encoding.

Keeping ASP.NET Session Open / Alive

Do you really need to keep the session (do you have data in it?) or is it enough to fake this by reinstantiating the session when a request comes in? If the first, use the method above. If the second, try something like using the Session_End event handler.

If you have Forms Authentication, then you get something in the Global.asax.cs like

FormsAuthenticationTicket ticket = FormsAuthentication.Decrypt(formsCookie.Value);
if (ticket.Expired)
{
    Request.Cookies.Remove(FormsAuthentication.FormsCookieName);
    FormsAuthentication.SignOut();
    ...             
     }
else
{   ...
    // renew ticket if old
    ticket = FormsAuthentication.RenewTicketIfOld(ticket);
    ...
     }

And you set the ticket lifetime much longer than the session lifetime. If you're not authenticating, or using a different authentication method, there are similar tricks. Microsoft TFS web interface and SharePoint seem to use these - the give away is that if you click a link on a stale page, you get authentication prompts in the popup window, but if you just use a command, it works.

SQL Server equivalent of MySQL's NOW()?

You can also use CURRENT_TIMESTAMP, if you feel like being more ANSI compliant (though if you're porting code between database vendors, that'll be the least of your worries). It's exactly the same as GetDate() under the covers (see this question for more on that).

There's no ANSI equivalent for GetUTCDate(), however, which is probably the one you should be using if your app operates in more than a single time zone ...

Adobe Reader Command Line Reference

To open a PDF at page 100 the follow works

<path to Adobe Reader> /A "page=100" "<Path To PDF file>"

If you require more than one argument separate them with &

I use the following in a batch file to open the book I'm reading to the page I was up to.

C:\Program Files\Adobe\Reader 10.0\Reader\AcroRd32.exe /A "page=149&pagemode=none" "D:\books\MCTS(70-562) ASP.Net 3.5 Development.pdf"

The best list of command line args for Adobe Reader I have found is here.
http://partners.adobe.com/public/developer/en/acrobat/PDFOpenParameters.pdf

It's for version 7 but all the arguments I tried worked.

As for closing the file, I think you will need to use the SDK, or if you are opening the file from code you could close the file from code once you have finished with it.

Select2 doesn't work when embedded in a bootstrap modal

For Select2 v4:

Use dropdownParent to attach the dropdown to the modal dialog, rather than the HTML body.

<!-- Modal -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel">
  <div class="modal-dialog" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
        <h4 class="modal-title" id="myModalLabel">Modal title</h4>
      </div>
      <div class="modal-body">
        <select id="select2insidemodal" multiple="multiple">
          <option value="AL">Alabama</option>
            ...
          <option value="WY">Wyoming</option>
        </select>
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
    </div>
  </div>
</div>


<script>

$(document).ready(function() {
  $("#select2insidemodal").select2({
    dropdownParent: $("#myModal")
  });
});

</script>

This will attach the Select2 dropdown so it falls within the DOM of the modal rather than to the HTML body (the default). See https://select2.org/dropdown#dropdown-placement

Mocking a method to throw an exception (moq), but otherwise act like the mocked object?

Here's how you can mock your FileConnection

Mock<IFileConnection> fileConnection = new Mock<IFileConnection>(
                                                           MockBehavior.Strict);
fileConnection.Setup(item => item.Get(It.IsAny<string>,It.IsAny<string>))
              .Throws(new IOException());

Then instantiate your Transfer class and use the mock in your method call

Transfer transfer = new Transfer();
transfer.GetFile(fileConnection.Object, someRemoteFilename, someLocalFileName);

Update:

First of all you have to mock your dependencies only, not the class you are testing(Transfer class in this case). Stating those dependencies in your constructor make it easy to see what services your class needs to work. It also makes it possible to replace them with fakes when you are writing your unit tests. At the moment it's impossible to replace those properties with fakes.

Since you are setting those properties using another dependency, I would write it like this:

public class Transfer
{
    public Transfer(IInternalConfig internalConfig)
    {
        source = internalConfig.GetFileConnection("source");
        destination = internalConfig.GetFileConnection("destination");
    }

    //you should consider making these private or protected fields
    public virtual IFileConnection source { get; set; }
    public virtual IFileConnection destination { get; set; }

    public virtual void GetFile(IFileConnection connection, 
        string remoteFilename, string localFilename)
    {
        connection.Get(remoteFilename, localFilename);
    }

    public virtual void PutFile(IFileConnection connection, 
        string localFilename, string remoteFilename)
    {
        connection.Get(remoteFilename, localFilename);
    }

    public virtual void TransferFiles(string sourceName, string destName)
    {
        var tempName = Path.GetTempFileName();
        GetFile(source, sourceName, tempName);
        PutFile(destination, tempName, destName);
    }
}

This way you can mock internalConfig and make it return IFileConnection mocks that does what you want.

Specify system property to Maven project

I have learned it is also possible to do this with the exec-maven-plugin if you're doing a "standalone" java app.

            <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>exec-maven-plugin</artifactId>
            <version>${maven.exec.plugin.version}</version>
            <executions>
                <execution>
                    <goals>
                        <goal>java</goal>
                    </goals>
                </execution>
            </executions>
            <configuration>
                <mainClass>${exec.main-class}</mainClass>
                <systemProperties>
                    <systemProperty>
                        <key>myproperty</key>
                        <value>myvalue</value>
                    </systemProperty>
                </systemProperties>
            </configuration>
        </plugin>

Is #pragma once a safe include guard?

Using gcc 3.4 and 4.1 on very large trees (sometimes making use of distcc), I have yet to see any speed up when using #pragma once in lieu of, or in combination with standard include guards.

I really don't see how its worth potentially confusing older versions of gcc, or even other compilers since there's no real savings. I have not tried all of the various de-linters, but I'm willing to bet it will confuse many of them.

I too wish it had been adopted early on, but I can see the argument "Why do we need that when ifndef works perfectly fine?". Given C's many dark corners and complexities, include guards are one of the easiest, self explaining things. If you have even a small knowledge of how the preprocessor works, they should be self explanatory.

If you do observe a significant speed up, however, please update your question.

Objective-C: Reading a file line by line

As others have answered both NSInputStream and NSFileHandle are fine options, but it can also be done in a fairly compact way with NSData and memory mapping:

BRLineReader.h

#import <Foundation/Foundation.h>

@interface BRLineReader : NSObject

@property (readonly, nonatomic) NSData *data;
@property (readonly, nonatomic) NSUInteger linesRead;
@property (strong, nonatomic) NSCharacterSet *lineTrimCharacters;
@property (readonly, nonatomic) NSStringEncoding stringEncoding;

- (instancetype)initWithFile:(NSString *)filePath encoding:(NSStringEncoding)encoding;
- (instancetype)initWithData:(NSData *)data encoding:(NSStringEncoding)encoding;
- (NSString *)readLine;
- (NSString *)readTrimmedLine;
- (void)setLineSearchPosition:(NSUInteger)position;

@end

BRLineReader.m

#import "BRLineReader.h"

static unsigned char const BRLineReaderDelimiter = '\n';

@implementation BRLineReader
{
    NSRange _lastRange;
}

- (instancetype)initWithFile:(NSString *)filePath encoding:(NSStringEncoding)encoding
{
    self = [super init];
    if (self) {
        NSError *error = nil;
        _data = [NSData dataWithContentsOfFile:filePath options:NSDataReadingMappedAlways error:&error];
        if (!_data) {
            NSLog(@"%@", [error localizedDescription]);
        }
        _stringEncoding = encoding;
        _lineTrimCharacters = [NSCharacterSet whitespaceAndNewlineCharacterSet];
    }

    return self;
}

- (instancetype)initWithData:(NSData *)data encoding:(NSStringEncoding)encoding
{
    self = [super init];
    if (self) {
        _data = data;
        _stringEncoding = encoding;
        _lineTrimCharacters = [NSCharacterSet whitespaceAndNewlineCharacterSet];
    }

    return self;
}

- (NSString *)readLine
{
    NSUInteger dataLength = [_data length];
    NSUInteger beginPos = _lastRange.location + _lastRange.length;
    NSUInteger endPos = 0;
    if (beginPos == dataLength) {
        // End of file
        return nil;
    }

    unsigned char *buffer = (unsigned char *)[_data bytes];
    for (NSUInteger i = beginPos; i < dataLength; i++) {
        endPos = i;
        if (buffer[i] == BRLineReaderDelimiter) break;
    }

    // End of line found
    _lastRange = NSMakeRange(beginPos, endPos - beginPos + 1);
    NSData *lineData = [_data subdataWithRange:_lastRange];
    NSString *line = [[NSString alloc] initWithData:lineData encoding:_stringEncoding];
    _linesRead++;

    return line;
}

- (NSString *)readTrimmedLine
{
    return [[self readLine] stringByTrimmingCharactersInSet:_lineTrimCharacters];
}

- (void)setLineSearchPosition:(NSUInteger)position
{
    _lastRange = NSMakeRange(position, 0);
    _linesRead = 0;
}

@end

C# using streams

There is only one basic type of Stream. However in various circumstances some members will throw an exception when called because in that context the operation was not available.

For example a MemoryStream is simply a way to moves bytes into and out of a chunk of memory. Hence you can call Read and Write on it.

On the other hand a FileStream allows you to read or write (or both) from/to a file. Whether you can actually Read or Write depends on how the file was opened. You can't Write to a file if you only opened it for Read access.

Cmake is not able to find Python-libraries

Even after adding -DPYTHON_INCLUDE_DIR and -DPYTHON_LIBRARY as suggested above, I was still facing the error Could NOT find PythonInterp. What solved it was adding -DPYTHON_EXECUTABLE:FILEPATH= to cmake as suggested in https://github.com/pybind/pybind11/issues/99#issuecomment-182071479:

cmake .. \
-DPYTHON_INCLUDE_DIR=$(python -c "from distutils.sysconfig import get_python_inc; print(get_python_inc())")  \
-DPYTHON_LIBRARY=$(python -c "import distutils.sysconfig as sysconfig; print(sysconfig.get_config_var('LIBDIR'))") \
-DPYTHON_EXECUTABLE:FILEPATH=`which python`

Prolog "or" operator, query

you can 'invoke' alternative bindings on Y this way:

...registered(X, Y), (Y=ct101; Y=ct102; Y=ct103).

Note the parenthesis are required to keep the correct execution control flow. The ;/2 it's the general or operator. For your restricted use you could as well choice the more idiomatic

...registered(X, Y), member(Y, [ct101,ct102,ct103]).

that on backtracking binds Y to each member of the list.

edit I understood with a delay your last requirement. If you want that Y match all 3 values the or is inappropriate, use instead

...registered(X, ct101), registered(X, ct102), registered(X, ct103).

or the more compact

...findall(Y, registered(X, Y), L), sort(L, [ct101,ct102,ct103]).

findall/3 build the list in the very same order that registered/2 succeeds. Then I use sort to ensure the matching.

...setof(Y, registered(X, Y), [ct101,ct102,ct103]).

setof/3 also sorts the result list

How to remove border from specific PrimeFaces p:panelGrid?

for me only the following code works

.noBorder tr {
border-width: 0 ;
}
.ui-panelgrid td{
    border-width: 0
}

<p:panelGrid id="userFormFields" columns="2" styleClass="noBorder" >
</p:panelGrid>

How to read pickle file?

Pickle serializes a single object at a time, and reads back a single object - the pickled data is recorded in sequence on the file.

If you simply do pickle.load you should be reading the first object serialized into the file (not the last one as you've written).

After unserializing the first object, the file-pointer is at the beggining of the next object - if you simply call pickle.load again, it will read that next object - do that until the end of the file.

objects = []
with (open("myfile", "rb")) as openfile:
    while True:
        try:
            objects.append(pickle.load(openfile))
        except EOFError:
            break

GridView must be placed inside a form tag with runat="server" even after the GridView is within a form tag

An alternative to overriding VerifyRenderingInServerForm is to remove the grid from the controls collection while you do the render, and then add it back when you are finished before the page loads. This is helpful if you want to have some generic helper method to get grid html because you don't have to remember to add the override.

Control parent = grid.Parent;
int GridIndex = 0;
if (parent != null)
{
    GridIndex = parent.Controls.IndexOf(grid);
    parent.Controls.Remove(grid);
}

grid.RenderControl(hw);

if (parent != null)
{
    parent.Controls.AddAt(GridIndex, grid);
}

Another alternative to avoid the override is to do this:

grid.RenderBeginTag(hw);
grid.HeaderRow.RenderControl(hw);
foreach (GridViewRow row in grid.Rows)
{
    row.RenderControl(hw);
}
grid.FooterRow.RenderControl(hw);
grid.RenderEndTag(hw);

increase the java heap size permanently?

Apparently, _JAVA_OPTIONS works on Linux, too:

$ export _JAVA_OPTIONS="-Xmx1g"
$ java -jar jconsole.jar &
Picked up _JAVA_OPTIONS: -Xmx1g

Search for value in DataGridView in a column

Why don't you build a DataTable first then assign it to the DataGridView as DataSource:

DataTable table4DataSource=new DataTable();

table4DataSource.Columns.Add("col00");
table4DataSource.Columns.Add("col01");
table4DataSource.Columns.Add("col02");

...

(add your rows, manually, in a circle or via a DataReader from a database table) (assign the datasource)

dtGrdViewGrid.DataSource = table4DataSource;

and then use:

(dtGrdViewGrid.DataSource as DataTable).DefaultView.RowFilter = "col00 = '" + textBoxSearch.Text+ "'";
dtGrdViewGrid.Refresh();

You can even put this piece of code within your textbox_textchange event and your filtered values will be showing as you write.

Using a BOOL property

Apple simply recommends declaring an isX getter for stylistic purposes. It doesn't matter whether you customize the getter name or not, as long as you use the dot notation or message notation with the correct name. If you're going to use the dot notation it makes no difference, you still access it by the property name:

@property (nonatomic, assign) BOOL working;

[self setWorking:YES];         // Or self.working = YES;
BOOL working = [self working]; // Or = self.working;

Or

@property (nonatomic, assign, getter=isWorking) BOOL working;

[self setWorking:YES];           // Or self.working = YES;, same as above
BOOL working = [self isWorking]; // Or = self.working;, also same as above

Get domain name from given url

private static final String hostExtractorRegexString = "(?:https?://)?(?:www\\.)?(.+\\.)(com|au\\.uk|co\\.in|be|in|uk|org\\.in|org|net|edu|gov|mil)";
private static final Pattern hostExtractorRegexPattern = Pattern.compile(hostExtractorRegexString);

public static String getDomainName(String url){
    if (url == null) return null;
    url = url.trim();
    Matcher m = hostExtractorRegexPattern.matcher(url);
    if(m.find() && m.groupCount() == 2) {
        return m.group(1) + m.group(2);
    }
    return null;
}

Explanation : The regex has 4 groups. The first two are non-matching groups and the next two are matching groups.

The first non-matching group is "http" or "https" or ""

The second non-matching group is "www." or ""

The second matching group is the top level domain

The first matching group is anything after the non-matching groups and anything before the top level domain

The concatenation of the two matching groups will give us the domain/host name.

PS : Note that you can add any number of supported domains to the regex.

SHA1 vs md5 vs SHA256: which to use for a PHP login?

Use argon2i. The argon2 password hashing function has won the Password Hashing Competition.

Other reasonable choices, if using argon2 is not available, are scrypt, bcrypt and PBKDF2. Wikipedia has pages for these functions:

MD5, SHA1 and SHA256 are message digests, not password-hashing functions. They are not suitable for this purpose.

Switching from MD5 to SHA1 or SHA512 will not improve the security of the construction so much. Computing a SHA256 or SHA512 hash is very fast. An attacker with common hardware could still try tens of millions (with a single CPU) or even billions (with a single GPU) of hashes per second. Good password hashing functions include a work factor to slow down dictionary attacks.

Here is a suggestion for PHP programmers: read the PHP FAQ then use password_hash().

C# How can I check if a URL exists/is valid?

You could issue a "HEAD" request rather than a "GET"?

(edit) - lol! Looks like I've done this before!; changed to wiki to avoid accusations of rep-garnering. So to test a URL without the cost of downloading the content:

// using MyClient from linked post
using(var client = new MyClient()) {
    client.HeadOnly = true;
    // fine, no content downloaded
    string s1 = client.DownloadString("http://google.com");
    // throws 404
    string s2 = client.DownloadString("http://google.com/silly");
}

You would try/catch around the DownloadString to check for errors; no error? It exists...


With C# 2.0 (VS2005):

private bool headOnly;
public bool HeadOnly {
    get {return headOnly;}
    set {headOnly = value;}
}

and

using(WebClient client = new MyClient())
{
    // code as before
}

java.io.FileNotFoundException: (Access is denied)

You cannot open and read a directory, use the isFile() and isDirectory() methods to distinguish between files and folders. You can get the contents of folders using the list() and listFiles() methods (for filenames and Files respectively) you can also specify a filter that selects a subset of files listed.

Closure in Java 7

A closure is a block of code that can be referenced (and passed around) with access to the variables of the enclosing scope.

Since Java 1.1, anonymous inner class have provided this facility in a highly verbose manner. They also have a restriction of only being able to use final (and definitely assigned) local variables. (Note, even non-final local variables are in scope, but cannot be used.)

Java SE 8 is intended to have a more concise version of this for single-method interfaces*, called "lambdas". Lambdas have much the same restrictions as anonymous inner classes, although some details vary randomly.

Lambdas are being developed under Project Lambda and JSR 335.

*Originally the design was more flexible allowing Single Abstract Methods (SAM) types. Unfortunately the new design is less flexible, but does attempt to justify allowing implementation within interfaces.

PreparedStatement with Statement.RETURN_GENERATED_KEYS

String query = "INSERT INTO ....";
PreparedStatement preparedStatement = connection.prepareStatement(query, PreparedStatement.RETURN_GENERATED_KEYS);

preparedStatement.setXXX(1, VALUE); 
preparedStatement.setXXX(2, VALUE); 
....
preparedStatement.executeUpdate();  

ResultSet rs = preparedStatement.getGeneratedKeys();  
int key = rs.next() ? rs.getInt(1) : 0;

if(key!=0){
    System.out.println("Generated key="+key);
}

Xcode 5.1 - No architectures to compile for (ONLY_ACTIVE_ARCH=YES, active arch=x86_64, VALID_ARCHS=i386)

Just in case, for anyone still encountering the issue despite following the above, check that the simulator you are running is also the supported one. I had mine specified to arm7 and arm7s but was trying to run the app on a 64 bit simulator.

How do I initialize an empty array in C#?

I had tried:

string[] sample = new string[0];

But I could only insert one string into it, and then I got an exceptionOutOfBound error, so I just simply put a size for it, like

string[] sample = new string[100];

Or another way that work for me:

List<string> sample = new List<string>();

Assigning Value for list:

sample.Add(your input);

Capitalize only first character of string and leave others alone? (Rails)

This should do it:

title = "test test"     
title[0] = title[0].capitalize
puts title # "Test test"

How to create virtual column using MySQL SELECT?

You can add virtual columns as

SELECT '1' as temp

But if you tries to put where condition to additionally generated column, it wont work and will show an error message as the column doesn't exist.

We can solve this issue by returning sql result as a table.ie,

SELECT tb.* from (SELECT 1 as temp) as tb WHERE tb.temp = 1

Function for 'does matrix contain value X?'

For floating point data, you can use the new ismembertol function, which computes set membership with a specified tolerance. This is similar to the ismemberf function found in the File Exchange except that it is now built-in to MATLAB. Example:

>> pi_estimate = 3.14159;
>> abs(pi_estimate - pi)
ans =
   5.3590e-08
>> tol = 1e-7;
>> ismembertol(pi,pi_estimate,tol)
ans =
     1

How to recover the deleted files using "rm -R" command in linux server?

Not possible with standard unix commands. You might have luck with a file recovery utility. Also, be aware, using rm changes the table of contents to mark those blocks as available to be overwritten, so simply using your computer right now risks those blocks being overwritten permanently. If it's critical data, you should turn off the computer before the file sectors gets overwritten. Good luck!

Some restore utility: http://www.ubuntugeek.com/recover-deleted-files-with-foremostscalpel-in-ubuntu.html

Forum where this was previously answered: http://webcache.googleusercontent.com/search?q=cache:m4hiPw-_GekJ:ubuntuforums.org/archive/index.php/t-1134955.html+&cd=1&hl=en&ct=clnk&gl=us

How to search file text for a pattern and replace it with a given value

Actually, Ruby does have an in-place editing feature. Like Perl, you can say

ruby -pi.bak -e "gsub(/oldtext/, 'newtext')" *.txt

This will apply the code in double-quotes to all files in the current directory whose names end with ".txt". Backup copies of edited files will be created with a ".bak" extension ("foobar.txt.bak" I think).

NOTE: this does not appear to work for multiline searches. For those, you have to do it the other less pretty way, with a wrapper script around the regex.