Programs & Examples On #Captured variable

How do I convert hex to decimal in Python?

>>> int("0xff", 16)
255

or

>>> int("FFFF", 16)
65535

Read the docs.

Multithreading in Bash

Bash job control involves multiple processes, not multiple threads.

You can execute a command in background with the & suffix.

You can wait for completion of a background command with the wait command.

You can execute multiple commands in parallel by separating them with |. This provides also a synchronization mechanism, since stdout of a command at left of | is connected to stdin of command at right.

Limiting the output of PHP's echo to 200 characters

<?php echo substr($row['style_info'], 0, 200) .((strlen($row['style_info']) > 200) ? '...' : ''); ?> 

How can I overwrite file contents with new content in PHP?

$fname = "database.php";
$fhandle = fopen($fname,"r");
$content = fread($fhandle,filesize($fname));
$content = str_replace("192.168.1.198", "localhost", $content);

$fhandle = fopen($fname,"w");
fwrite($fhandle,$content);
fclose($fhandle);

Java 8 stream reverse order

With regard to the specific question of generating a reverse IntStream:

starting from Java 9 you can use the three-argument version of the IntStream.iterate(...):

IntStream.iterate(10, x -> x >= 0, x -> x - 1).forEach(System.out::println);

// Out: 10 9 8 7 6 5 4 3 2 1 0

where:

IntStream.iterate?(int seed, IntPredicate hasNext, IntUnaryOperator next);

  • seed - the initial element;
  • hasNext - a predicate to apply to elements to determine when the stream must terminate;
  • next - a function to be applied to the previous element to produce a new element.

Could not load file or assembly 'System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' or one of its dependencies

i just changed my target .net framework and it worked .in my case i changed from .net 4.7 to .net 4. Right click your solution and select properties selct properties

Click Application >> Target Framework

How to put attributes via XElement

Add XAttribute in the constructor of the XElement, like

new XElement("Conn", new XAttribute("Server", comboBox1.Text));

You can also add multiple attributes or elements via the constructor

new XElement("Conn", new XAttribute("Server", comboBox1.Text), new XAttribute("Database", combobox2.Text));

or you can use the Add-Method of the XElement to add attributes

XElement element = new XElement("Conn");
XAttribute attribute = new XAttribute("Server", comboBox1.Text);
element.Add(attribute);

How to make a loop in x86 assembly language?

You need to use conditional jmp commands. This isn't the same syntax as you're using; looks like MASM, but using GAS here's an example from some code I wrote to calculate gcd:

gcd_alg:
    subl    %ecx, %eax      /* a = a - c */
    cmpl    $0, %eax        /* if a == 0 */
    je      gcd_done        /* jump to end */
    cmpl    %ecx, %eax      /* if a < c */
    jl      gcd_preswap     /* swap and start over */
    jmp     gcd_alg         /* keep subtracting */

Basically, I compare two registers with the cmpl instruction (compare long). If it is less the JL (jump less) instruction jumps to the preswap location, otherwise it jumps back to the same label.

As for clearing the screen, that depends on the system you're using.

Still Reachable Leak detected by Valgrind

Here is a proper explanation of "still reachable":

"Still reachable" are leaks assigned to global and static-local variables. Because valgrind tracks global and static variables it can exclude memory allocations that are assigned "once-and-forget". A global variable assigned an allocation once and never reassigned that allocation is typically not a "leak" in the sense that it does not grow indefinitely. It is still a leak in the strict sense, but can usually be ignored unless you are pedantic.

Local variables that are assigned allocations and not free'd are almost always leaks.

Here is an example

int foo(void)
{
    static char *working_buf = NULL;
    char *temp_buf;
    if (!working_buf) {
         working_buf = (char *) malloc(16 * 1024);
    }
    temp_buf = (char *) malloc(5 * 1024);

    ....
    ....
    ....

}

Valgrind will report working_buf as "still reachable - 16k" and temp_buf as "definitely lost - 5k".

Struct Constructor in C++?

In c++ struct and c++ class have only one difference by default struct members are public and class members are private.

/*Here, C++ program constructor in struct*/ 
#include <iostream>
using namespace std;

struct hello
    {
    public:     //by default also it is public
        hello();    
        ~hello();
    };

hello::hello()
    {
    cout<<"calling constructor...!"<<endl;
    }

hello::~hello()
    {
    cout<<"calling destructor...!"<<endl;
    }

int main()
{
hello obj;      //creating a hello obj, calling hello constructor and destructor 

return 0;
}

Scale the contents of a div by a percentage?

You can simply use the zoom property:

#myContainer{
    zoom: 0.5;
    -moz-transform: scale(0.5);
}

Where myContainer contains all the elements you're editing. This is supported in all major browsers.

Resizing image in Java

Try this:

ImageIcon icon = new ImageIcon(UrlToPngFile);
Image scaleImage = icon.getImage().getScaledInstance(28, 28,Image.SCALE_DEFAULT);

Make docker use IPv4 for port binding

For CentOS users,

I've got same issue on CentOS7 and setting net.ipv4.ip_forward to 1 solves the issue. Please, refer to Docker Networking Disabled: WARNING: IPv4 forwarding is disabled. Networking will not work for more details.

iPhone UIView Animation Best Practice

The difference seems to be the amount of control you need over the animation.

The CATransition approach gives you more control and therefore more things to set up, eg. the timing function. Being an object, you can store it for later, refactor to point all your animations at it to reduce duplicated code, etc.

The UIView class methods are convenience methods for common animations, but are more limited than CATransition. For example, there are only four possible transition types (flip left, flip right, curl up, curl down). If you wanted to do a fade in, you'd have to either dig down to CATransition's fade transition, or set up an explicit animation of your UIView's alpha.

Note that CATransition on Mac OS X will let you specify an arbitrary CoreImage filter to use as a transition, but as it stands now you can't do this on the iPhone, which lacks CoreImage.

How to verify Facebook access token?

I found this official tool from facebook developer page, this page will you following information related to access token - App ID, Type, App-Scoped,User last installed this app via, Issued, Expires, Data Access Expires, Valid, Origin, Scopes. Just need access token.

https://developers.facebook.com/tools/debug/accesstoken/

scrollable div inside container

If you put overflow: scroll on a fixed height div, the div will scroll if the contents take up too much space.

Where does mysql store data?

In mysql server 8.0, on Windows, the location is C:\ProgramData\MySQL\MySQL Server 8.0\Data

How to wait until WebBrowser is completely loaded in VB.NET?

Sometimes if you use JavaScript the DocumentComplete event don't return the right answer; I use the event ProgressChanged instead:

Private Sub WebBrowser1_ProgressChanged(sender As Object, e As WebBrowserProgressChangedEventArgs) Handles WebBrowser1.ProgressChanged

        Console.WriteLine("Current Progress: " + e.CurrentProgress.ToString)

        If e.CurrentProgress = e.MaximumProgress Then

            ' The maximum progress is reached
            load_started = True

        End If

        ' The page is confirmed downloaded after the progress returns to 0
        If e.CurrentProgress = 0 Then

            If load_started Then

                ' The page is ready to print or download...
                WebBrowser1.Print()
                load_started = False

            End If

        End If

End Sub

Entity Framework - Code First - Can't Store List<String>

EF Core 2.1+ :

Property:

public string[] Strings { get; set; }

OnModelCreating:

modelBuilder.Entity<YourEntity>()
            .Property(e => e.Strings)
            .HasConversion(
                v => string.Join(',', v),
                v => v.Split(',', StringSplitOptions.RemoveEmptyEntries));

Update (2021-02-14)

The PostgreSQL has an array data type and the Npgsql EF Core provider does support that. So it will map your C# arrays and lists to the PostgreSQL array data type automatically and no extra config is required. Also you can operate on the array and the operation will be translated to SQL.

More information on this page.

HTML table needs spacing between columns, not rows

<table cellpadding="pixels"cellspacing="pixels"></table>
<td align="position"valign="position"></td>

cellpadding="length in pixels" ~ The cellpadding attribute, used in the <table> tag, specifies how much blank space to display in between the content of each table cell and its respective border. The value is defined as a length in pixels. Hence, a cellpadding="10" attribute-value pair will display 10 pixels of blank space on all four sides of the content of each cell in that table.

cellspacing="length in pixels" ~ The cellspacing attribute, also used in the <table> tag, defines how much blank space to display in between adjacent table cells and in between table cells and the table border. The value is defined as a length in pixels. Hence, a cellspacing="10" attribute-value pair will horizontally and vertically separate all adjacent cells in the respective table by a length of 10 pixels. It will also offset all cells from the table's frame on all four sides by a length of 10 pixels.

How to convert string to long

IF your input is String then I recommend you to store the String into a double and then convert the double to the long.

String str = "123.45";
Double  a = Double.parseDouble(str);

long b = Math.round(a);

Random number generator only generating one random number

1) As Marc Gravell said, try to use ONE random-generator. It's always cool to add this to the constructor: System.Environment.TickCount.

2) One tip. Let's say you want to create 100 objects and suppose each of them should have its-own random-generator (handy if you calculate LOADS of random numbers in a very short period of time). If you would do this in a loop (generation of 100 objects), you could do this like that (to assure fully-randomness):

int inMyRandSeed;

for(int i=0;i<100;i++)
{
   inMyRandSeed = System.Environment.TickCount + i;
   .
   .
   .
   myNewObject = new MyNewObject(inMyRandSeed);  
   .
   .
   .
}

// Usage: Random m_rndGen = new Random(inMyRandSeed);

Cheers.

How to add data via $.ajax ( serialize() + extra data ) like this

Personally, I'd append the element to the form instead of hacking the serialized data, e.g.

moredata = 'your custom data here';

// do what you like with the input
$input = $('<input type="text" name="moredata"/>').val(morevalue);

// append to the form
$('#myForm').append($input);

// then..
data: $('#myForm').serialize()

That way, you don't have to worry about ? or &

How to select all columns, except one column in pandas?

When the columns are not a MultiIndex, df.columns is just an array of column names so you can do:

df.loc[:, df.columns != 'b']

          a         c         d
0  0.561196  0.013768  0.772827
1  0.882641  0.615396  0.075381
2  0.368824  0.651378  0.397203
3  0.788730  0.568099  0.869127

Wordpress - Images not showing up in the Media Library

Did you ever change the directory of your Wordpress install?

I had a problem with not finding my uploaded images after changing the Wordpress location on my server. In Wordpress, I went to Dashboard-> Settings -> Media and changed the uploads folder in the "Store uploads in this folder" field.

Open Cygwin at a specific folder

Probably the simplest one:

1) Create file foo.reg

2) Insert content:

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\Directory\background\shell\open_mintty]
@="open mintty"

[HKEY_CLASSES_ROOT\Directory\background\shell\open_mintty\command]
@="cmd /C mintty"

3) Execute foo.reg

Now just right-click in any folder, click open mintty and it will spawn mintty in that folder.

Bootstrap 4: responsive sidebar menu to top navbar

It could be done in Bootstrap 4 using the responsive grid columns. One column for the sidebar and one for the main content.

Bootstrap 4 Sidebar switch to Top Navbar on mobile

<div class="container-fluid h-100">
    <div class="row h-100">
        <aside class="col-12 col-md-2 p-0 bg-dark">
            <nav class="navbar navbar-expand navbar-dark bg-dark flex-md-column flex-row align-items-start">
                <div class="collapse navbar-collapse">
                    <ul class="flex-md-column flex-row navbar-nav w-100 justify-content-between">
                        <li class="nav-item">
                            <a class="nav-link pl-0" href="#">Link</a>
                        </li>
                        ..
                    </ul>
                </div>
            </nav>
        </aside>
        <main class="col">
            ..
        </main>
    </div>
</div>

Alternate sidebar to top
Fixed sidebar to top

For the reverse (Top Navbar that becomes a Sidebar), can be done like this example

Get text from pressed button

The view you get passed in on onClick() is the Button you are looking for.

public void onClick(View v) {
    // 1) Possibly check for instance of first 
    Button b = (Button)v;
    String buttonText = b.getText().toString();
}

1) If you are using a non-anonymous class as onClickListener, you may want to check for the type of the view before casting it, as it may be something different than a Button.

How to add a fragment to a programmatically generated layout?

Below is a working code to add a fragment e.g 3 times to a vertical LinearLayout (xNumberLinear). You can change number 3 with any other number or take a number from a spinner!

for (int i = 0; i < 3; i++) {
            LinearLayout linearDummy = new LinearLayout(getActivity());
            linearDummy.setOrientation(LinearLayout.VERTICAL);
            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1) {

                Toast.makeText(getActivity(), "This function works on newer versions of android", Toast.LENGTH_LONG).show();

            } else {
                linearDummy.setId(View.generateViewId());
            }
            fragmentManager.beginTransaction().add(linearDummy.getId(), new SomeFragment(),"someTag1").commit();

            xNumberLinear.addView(linearDummy);
        }

Setting button text via javascript

Use textContent instead of value to set the button text.

Typically the value attribute is used to associate a value with the button when it's submitted as form data.

Note that while it's possible to set the button text with innerHTML, using textContext should be preferred because it's more performant and it can prevent cross-site scripting attacks as its value is not parsed as HTML.

JS:

var b = document.createElement('button');
b.setAttribute('content', 'test content');
b.setAttribute('class', 'btn');  
b.textContent = 'test value';

var wrapper = document.getElementById("divWrapper");
wrapper.appendChild(b);

Produces this in the DOM:

<div id="divWrapper">
    <button content="test content" class="btn">test value</button>
</div>

Demo: https://jsfiddle.net/13ucp6ob/

Set value for particular cell in pandas DataFrame with iloc

For mixed position and index, use .ix. BUT you need to make sure that your index is not of integer, otherwise it will cause confusions.

df.ix[0, 'COL_NAME'] = x

Update:

Alternatively, try

df.iloc[0, df.columns.get_loc('COL_NAME')] = x

Example:

import pandas as pd
import numpy as np

# your data
# ========================
np.random.seed(0)
df = pd.DataFrame(np.random.randn(10, 2), columns=['col1', 'col2'], index=np.random.randint(1,100,10)).sort_index()

print(df)


      col1    col2
10  1.7641  0.4002
24  0.1440  1.4543
29  0.3131 -0.8541
32  0.9501 -0.1514
33  1.8676 -0.9773
36  0.7610  0.1217
56  1.4941 -0.2052
58  0.9787  2.2409
75 -0.1032  0.4106
76  0.4439  0.3337

# .iloc with get_loc
# ===================================
df.iloc[0, df.columns.get_loc('col2')] = 100

df

      col1      col2
10  1.7641  100.0000
24  0.1440    1.4543
29  0.3131   -0.8541
32  0.9501   -0.1514
33  1.8676   -0.9773
36  0.7610    0.1217
56  1.4941   -0.2052
58  0.9787    2.2409
75 -0.1032    0.4106
76  0.4439    0.3337

C++ unordered_map using a custom class type as the key

Most basic possible copy/paste complete runnable example of using a custom class as the key for an unordered_map (basic implementation of a sparse matrix):

// UnorderedMapObjectAsKey.cpp

#include <iostream>
#include <vector>
#include <unordered_map>

struct Pos
{
  int row;
  int col;

  Pos() { }
  Pos(int row, int col)
  {
    this->row = row;
    this->col = col;
  }

  bool operator==(const Pos& otherPos) const
  {
    if (this->row == otherPos.row && this->col == otherPos.col) return true;
    else return false;
  }

  struct HashFunction
  {
    size_t operator()(const Pos& pos) const
    {
      size_t rowHash = std::hash<int>()(pos.row);
      size_t colHash = std::hash<int>()(pos.col) << 1;
      return rowHash ^ colHash;
    }
  };
};

int main(void)
{
  std::unordered_map<Pos, int, Pos::HashFunction> umap;

  // at row 1, col 2, set value to 5
  umap[Pos(1, 2)] = 5;

  // at row 3, col 4, set value to 10
  umap[Pos(3, 4)] = 10;

  // print the umap
  std::cout << "\n";
  for (auto& element : umap)
  {
    std::cout << "( " << element.first.row << ", " << element.first.col << " ) = " << element.second << "\n";
  }
  std::cout << "\n";

  return 0;
}

Get an object's class name at runtime

Simple answer :

class MyClass {}

const instance = new MyClass();

console.log(instance.constructor.name); // MyClass
console.log(MyClass.name);              // MyClass

However: beware that the name will likely be different when using minified code.

Text in a flex container doesn't wrap in IE11

I had a similar issue with overflowing images in a flex wrapper.

Adding either flex-basis: 100%; or flex: 1; to the overflowing child fixed worked for me.

Div table-cell vertical align not working

In my case, I wanted to center in a parent container with position: absolute.

<div class="absolute-container">
    <div class="parent-container">
        <div class="centered-content">
            My content
        </div>
    </div>
</div>

I had to add some positioning for top, bottom, left & right.

.absolute-container {
    position:absolute;
    top:0;
    left:0;
    bottom:0;
    right:0;
}

.parent-container {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    display: table
}

.centered-content {
    display: table-cell;
    text-align: center;
    vertical-align: middle
}

How to check if std::map contains a key without doing insert?

Use my_map.count( key ); it can only return 0 or 1, which is essentially the Boolean result you want.

Alternately my_map.find( key ) != my_map.end() works too.

JS: Uncaught TypeError: object is not a function (onclick)

Please change only the name of the function; no other change is required

<script>
    function totalbandwidthresult() {
        alert("fdf");
        var fps = Number(document.calculator.fps.value);
        var bitrate = Number(document.calculator.bitrate.value);
        var numberofcameras = Number(document.calculator.numberofcameras.value);
        var encoding = document.calculator.encoding.value;
        if (encoding = "mjpeg") {
            storage = bitrate * fps;
        } else {
            storage = bitrate;
        }

        totalbandwidth = (numberofcameras * storage) / 1000;
        alert(totalbandwidth);
        document.calculator.totalbandwidthresult.value = totalbandwidth;
    }
</script>

<form name="calculator" class="formtable">
    <div class="formrow">
        <label for="rcname">RC Name</label>
        <input type="text" name="rcname">
    </div>
    <div class="formrow">
        <label for="fps">FPS</label>
        <input type="text" name="fps">
    </div>
    <div class="formrow">
        <label for="bitrate">Bitrate</label>
        <input type="text" name="bitrate">
    </div>
    <div class="formrow">
        <label for="numberofcameras">Number of Cameras</label>
        <input type="text" name="numberofcameras">
    </div>
    <div class="formrow">
        <label for="encoding">Encoding</label>
        <select name="encoding" id="encodingoptions">
            <option value="h264">H.264</option>
            <option value="mjpeg">MJPEG</option>
            <option value="mpeg4">MPEG4</option>
        </select>
    </div>Total Storage:
    <input type="text" name="totalstorage">Total Bandwidth:
    <input type="text" name="totalbandwidth">
    <input type="button" value="totalbandwidthresult" onclick="totalbandwidthresult();">
</form>

Simplest way to form a union of two lists

The easiest way is to use LINQ's Union method:

var aUb = A.Union(B).ToList();

How to manually deploy artifacts in Nexus Repository Manager OSS 3

This is implemented in Nexus since Version 3.9.0.

  • Login
  • Select Upload

enter image description here

  • Fill out form and upload Artifact

enter image description here

Getting file names without extensions

FileInfo knows its own extension, so you could just remove it

fileInfo.Name.Replace(fileInfo.Extension, "");
fileInfo.FullName.Replace(fileInfo.Extension, "");

or if you're paranoid that it might appear in the middle, or want to microoptimize:

file.Name.Substring(0, file.Name.Length - file.Extension.Length)

Jenkins - how to build a specific branch

This is extension of answer provided by Ranjith

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

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

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

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

First letter capitalization for EditText

I encountered the same problem, just sharing what I found out. Might help you and others...

Try this on your layout.add the line below in your EditText.

android:inputType="textCapWords|textCapSentences"

works fine on me.. hope it works also on you...

Where can I download Eclipse Android bundle?

Google has ended support for eclipse plugin. If you prefer to use eclipse still you can download Eclipse Android Development Tool from

ADT for Eclipse

ListView inside ScrollView is not scrolling on Android

Here is the exact method of using Listview with in the Scrollview. All we have to handle touch events.

      lstvNextTracks.setOnTouchListener(new OnTouchListener()
      {
          @Override
          public boolean onTouch(View v, MotionEvent event)
          {
         Log.e("Lisview *************", "focused");
         SCView.requestDisallowInterceptTouchEvent(true);
         return false;
          }
      });




    SCView.setOnTouchListener(new OnTouchListener()
    {

        @Override
        public boolean onTouch(View v, MotionEvent event)
        {
            int arr[] = new int[] { 1, 2 };
            lstvNextTracks.getLocationOnScreen(arr);

            /* Get bounds of child Listview*/
            int lstvTop = arr[0];
            int lstvBottom = arr[1] + lstvNextTracks.getHeight();
            int lstvLeft = arr[1];
            int lstvRight = arr[0] + lstvNextTracks.getWidth();

            float x = event.getRawX();
            float y = event.getRawY();

            if (event.getAction() == MotionEvent.ACTION_DOWN)
            {
                /*check if child ListView bounds are touched*/
                if (x > lstvTop && x < lstvBottom && y > lstvLeft && y < lstvRight)
                {
                    SCView.clearFocus();
                    /*This statement tells the ScrollView to do not handle this touch event, so the child Listview will handle this touch event and will scroll */
                    SCView.requestDisallowInterceptTouchEvent(true);
                    /*The child Listview isFocusable attribute must be set to true otherwise it will not work*/
                    lstvNextTracks.requestFocus();
                    return true;
                } else
                    return false;
            } else if (event.getAction() == MotionEvent.ACTION_MOVE)
            {

                if (x > lstvTop && x < lstvBottom && y > lstvLeft && y < lstvRight)
                {
                    SCView.clearFocus();
                    SCView.requestDisallowInterceptTouchEvent(true);
                    lstvNextTracks.requestFocus();
                    return true;
                } else
                    return false;
            } else if (event.getAction() == MotionEvent.ACTION_UP)
            {
                SCView.clearFocus();
                SCView.requestDisallowInterceptTouchEvent(true);
                lstvNextTracks.requestFocus();
                return false;
            } else
            {
                return false;
            }
        }
    });

How can I upgrade NumPy?

I tried doing sudo pip uninstall numpy instead, because the rm didn't work at first.

Hopefully that helps.

Uninstalling then to install it again.

How to find the operating system version using JavaScript?

var OSName = "Unknown";
if (window.navigator.userAgent.indexOf("Windows NT 10.0")!= -1) OSName="Windows 10";
if (window.navigator.userAgent.indexOf("Windows NT 6.3") != -1) OSName="Windows 8.1";
if (window.navigator.userAgent.indexOf("Windows NT 6.2") != -1) OSName="Windows 8";
if (window.navigator.userAgent.indexOf("Windows NT 6.1") != -1) OSName="Windows 7";
if (window.navigator.userAgent.indexOf("Windows NT 6.0") != -1) OSName="Windows Vista";
if (window.navigator.userAgent.indexOf("Windows NT 5.1") != -1) OSName="Windows XP";
if (window.navigator.userAgent.indexOf("Windows NT 5.0") != -1) OSName="Windows 2000";
if (window.navigator.userAgent.indexOf("Mac")            != -1) OSName="Mac/iOS";
if (window.navigator.userAgent.indexOf("X11")            != -1) OSName="UNIX";
if (window.navigator.userAgent.indexOf("Linux")          != -1) OSName="Linux";

Remove part of string in Java

I would at first split the original string into an array of String with a token " (" and the String at position 0 of the output array is what you would like to have.

String[] output = originalString.split(" (");

String result = output[0];

Clear the form field after successful submission of php form

The POST data which holds the submitted form data is being echoed in the form, eg:

<input name="firstname" type="text" placeholder="First Name" required="required" 
value="<?php echo $_POST['firstname'];?>"  

Either clear the POST data once you have done with the form - ie all inputs were ok and you have actioned whatever your result from a form is.
Or, once you have determined the form is ok and have actioned whatever you action from the form, redirect the user to a new page to say "all done, thanks" etc.

header('Location: thanks.php');
exit();

This stops the POST data being present, it's know as "Post/Redirect/Get":
http://en.wikipedia.org/wiki/Post/Redirect/Get

The Post/Redirect/Get (PRG) method and using another page also ensures that if users click browser refresh, or back button having navigated somewhere else, your form is not submitted again.
This means if your form inserts into a database, or emails someone (etc), without the PRG method the values will (likely) be inserted/emailed every time they click refresh or revisit the page using their history/back button.

How to send emails from my Android application?

I used this code to send mail by launching default mail app compose section directly.

    Intent i = new Intent(Intent.ACTION_SENDTO);
    i.setType("message/rfc822"); 
    i.setData(Uri.parse("mailto:"));
    i.putExtra(Intent.EXTRA_EMAIL  , new String[]{"[email protected]"});
    i.putExtra(Intent.EXTRA_SUBJECT, "Subject");
    i.putExtra(Intent.EXTRA_TEXT   , "body of email");
    try {
        startActivity(Intent.createChooser(i, "Send mail..."));
    } catch (android.content.ActivityNotFoundException ex) {
        Toast.makeText(this, "There are no email clients installed.", Toast.LENGTH_SHORT).show();
    }

Ruby 'require' error: cannot load such file

Ruby 1.9 has removed the current directory from the load path, and so you will need to do a relative require on this file, as David Grayson says:

require_relative 'tokenizer'

There's no need to suffix it with .rb, as Ruby's smart enough to know that's what you mean anyway.

How do you declare an interface in C++?

As far I could test, it is very important to add the virtual destructor. I'm using objects created with new and destroyed with delete.

If you do not add the virtual destructor in the interface, then the destructor of the inherited class is not called.

class IBase {
public:
    virtual ~IBase() {}; // destructor, use it to call destructor of the inherit classes
    virtual void Describe() = 0; // pure virtual method
};

class Tester : public IBase {
public:
    Tester(std::string name);
    virtual ~Tester();
    virtual void Describe();
private:
    std::string privatename;
};

Tester::Tester(std::string name) {
    std::cout << "Tester constructor" << std::endl;
    this->privatename = name;
}

Tester::~Tester() {
    std::cout << "Tester destructor" << std::endl;
}

void Tester::Describe() {
    std::cout << "I'm Tester [" << this->privatename << "]" << std::endl;
}


void descriptor(IBase * obj) {
    obj->Describe();
}

int main(int argc, char** argv) {

    std::cout << std::endl << "Tester Testing..." << std::endl;
    Tester * obj1 = new Tester("Declared with Tester");
    descriptor(obj1);
    delete obj1;

    std::cout << std::endl << "IBase Testing..." << std::endl;
    IBase * obj2 = new Tester("Declared with IBase");
    descriptor(obj2);
    delete obj2;

    // this is a bad usage of the object since it is created with "new" but there are no "delete"
    std::cout << std::endl << "Tester not defined..." << std::endl;
    descriptor(new Tester("Not defined"));


    return 0;
}

If you run the previous code without virtual ~IBase() {};, you will see that the destructor Tester::~Tester() is never called.

ggplot legends - change labels, order and title

You need to do two things:

  1. Rename and re-order the factor levels before the plot
  2. Rename the title of each legend to the same title

The code:

dtt$model <- factor(dtt$model, levels=c("mb", "ma", "mc"), labels=c("MBB", "MAA", "MCC"))

library(ggplot2)
ggplot(dtt, aes(x=year, y=V, group = model, colour = model, ymin = lower, ymax = upper)) +
  geom_ribbon(alpha = 0.35, linetype=0)+ 
  geom_line(aes(linetype=model), size = 1) +       
  geom_point(aes(shape=model), size=4)  +      
  theme(legend.position=c(.6,0.8)) +
  theme(legend.background = element_rect(colour = 'black', fill = 'grey90', size = 1, linetype='solid')) +
  scale_linetype_discrete("Model 1") +
  scale_shape_discrete("Model 1") +
  scale_colour_discrete("Model 1")

enter image description here

However, I think this is really ugly as well as difficult to interpret. It's far better to use facets:

ggplot(dtt, aes(x=year, y=V, group = model, colour = model, ymin = lower, ymax = upper)) +
  geom_ribbon(alpha=0.2, colour=NA)+ 
  geom_line() +       
  geom_point()  +      
  facet_wrap(~model)

enter image description here

'ssh' is not recognized as an internal or external command

Actually you have 2 problems here: First is that you don't have ssh installed, second is that you don't know how to deploy

Install SSH

It seems that ssh is not installed on your computer.

You can install openssh from here : http://openssh.en.softonic.com/download

Generate your key

Than you will have to geneate your ssh-key. There's a good tutorial about this here:

https://help.github.com/articles/generating-ssh-keys#platform-windows

Deploy

To deploy, you just have to push your code over git. Something like this:

git push fort master

If you get permission denied, be sure that you have put your public_key in the dashboard in the git tab.

SSH

The ssh command gives you access to your remote node. You should have received a password by email and now that you have ssh installed, you should be asked for a password when trying to connect. just input that password. If you want to use your private ssh key to connect to your server rather then typing that password, you can follow this : http://fortrabbit.com/docs/how-to/ssh-sftp/enable-public-key-authentication

Properly embedding Youtube video into bootstrap 3.0 page

I know it's late, I have the same issue with an old custom theme, just added to boostrap.css:

.embed-responsive {
  position: relative;
  display: block;
  height: 0;
  padding: 0;
  overflow: hidden;
}
.embed-responsive .embed-responsive-item,
.embed-responsive iframe,
.embed-responsive embed,
.embed-responsive object,
.embed-responsive video {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}
.embed-responsive-16by9 {
  padding-bottom: 56.25%;
}
.embed-responsive-4by3 {
  padding-bottom: 75%;
}

And for the video:

<div class="embed-responsive embed-responsive-16by9" >
<iframe class="embed-responsive-item"  src="https://www.youtube.com/embed/jVIxe3YLNs8"></iframe>
</div>

How to change bower's default components folder?

Something worth mentioning...

As noted above by other contributors, using a .bowerrc file with the JSON

{ "directory": "some/path" }

is necessary -- HOWEVER, you may run into an issue on Windows while creating that file. If Windows gives you a message imploring you to add a "file name", simply use a text editor / IDE such as Notepad++.

Add the JSON to an unnamed file, save it as .bowerrc -- you're good to go!

Probably an easy assumption, but I hope this save others the unnecessary headache :)

When should I write the keyword 'inline' for a function/method?

When one should inline :

1.When one want to avoid overhead of things happening when function is called like parameter passing , control transfer, control return etc.

2.The function should be small,frequently called and making inline is really advantageous since as per 80-20 rule,try to make those function inline which has major impact on program performance.

As we know that inline is just a request to compiler similar to register and it will cost you at Object code size.

Disable scrolling in webview?

I don't know if you still need it or not, but here is the solution:

appView = (WebView) findViewById(R.id.appView); 
appView.setVerticalScrollBarEnabled(false);
appView.setHorizontalScrollBarEnabled(false);

What is the best or most commonly used JMX Console / Client

Alternatively, constructing a JMX console yourself doesn't need to be hard. Just plug in Jolokia and create a web page getting the attributes that you're interested in. Admittedly, it doesn't allow you to do trend analysis, but it does allow you to construct something that is really geared towards your purpose.

I constructed something in just a few lines: http://nxt.flotsam.nl/ears-and-eyes.html

How to change Screen buffer size in Windows Command Prompt from batch script

I'm expanding upon a comment that I posted here as most people won't notice the comment.

https://lifeboat.com/programs/console.exe is a compiled version of the Visual Basic program described at https://stackoverflow.com/a/4694566/1752929. My version simply sets the buffer height to 32766 which is the maximum buffer height available. It does not adjust anything else. If there is a lot of demand, I could create a more flexible program but generally you can just set other variables in your shortcut layout tab.

Following is the target I use in my shortcut where I wish to start in the f directory. (I have to set the directory this way as Windows won't let you set it any other way if you wish to run the command prompt as administrator.)

C:\Windows\System32\cmd.exe /k "console & cd /d c:\f"

Python logging: use milliseconds in time format

Adding msecs was the better option, Thanks. Here is my amendment using this with Python 3.5.3 in Blender

import logging
logging.basicConfig(level=logging.DEBUG, format='%(asctime)s.%(msecs)03d %(levelname)s:\t%(message)s', datefmt='%Y-%m-%d %H:%M:%S')
log = logging.getLogger(__name__)
log.info("Logging Info")
log.debug("Logging Debug")

How do I run Java .class files?

You have to put java in lower case and you have to add .class!

java HelloWorld2.class

HTTP Request in Swift with POST method

Swift 4 and above

@IBAction func submitAction(sender: UIButton) {

    //declare parameter as a dictionary which contains string as key and value combination. considering inputs are valid

    let parameters = ["id": 13, "name": "jack"]

    //create the url with URL
    let url = URL(string: "www.thisismylink.com/postName.php")! //change the url

    //create the session object
    let session = URLSession.shared

    //now create the URLRequest object using the url object
    var request = URLRequest(url: url)
    request.httpMethod = "POST" //set http method as POST

    do {
        request.httpBody = try JSONSerialization.data(withJSONObject: parameters, options: .prettyPrinted) // pass dictionary to nsdata object and set it as request body
    } catch let error {
        print(error.localizedDescription)
    }

    request.addValue("application/json", forHTTPHeaderField: "Content-Type")
    request.addValue("application/json", forHTTPHeaderField: "Accept")

    //create dataTask using the session object to send data to the server
    let task = session.dataTask(with: request as URLRequest, completionHandler: { data, response, error in

        guard error == nil else {
            return
        }

        guard let data = data else {
            return
        }

        do {
            //create json object from data
            if let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any] {
                print(json)
                // handle json...
            }
        } catch let error {
            print(error.localizedDescription)
        }
    })
    task.resume()
}

Allow User to input HTML in ASP.NET MVC - ValidateInput or AllowHtml

I have faced this problem during development of a E-Commerce site using NopCommerce, I got this solution by 3 different ways as like the previous answers. But according to the NopCommerce structure I didn't found those three at a time. I have just seen that there they are using just [AllowHtml] and it's working fine except any problem. As previously asked question

Personally I don't prefer [ValidateInput(false)] because i's skipping total model entity checking, which is insecure. But if anyone just write have a look here

[AllowHtml] 
public string BlogText {get;set;}

then it just skip only single property, and just allow only particular property and check hardly all other entities. Therefore it seems preferable towards mine.

How do I create a folder in VB if it doesn't exist?

If Not Directory.Exists(somePath) then
    Directory.CreateDirectory(somePath)
End If

How do I get column names to print in this C# program?

You need to loop over loadDT.Columns, like this:

foreach (DataColumn column in loadDT.Columns)
{
    Console.Write("Item: ");
    Console.Write(column.ColumnName);
    Console.Write(" ");
    Console.WriteLine(row[column]);
}

JavaScript Infinitely Looping slideshow with delays?

Perhps this is what you are looking for.

var pos = 0;
window.onload = function start() {
    setTimeout(slide, 3000);
}
function slide() {
   pos -= 600;
   if (pos === -2400)
     pos = 0;
   document.getElementById('container').style.marginLeft= pos + "px";
   setTimeout(slide, 3000);
}

What is the equivalent of the C++ Pair<L,R> in Java?

For programming languages like Java, the alternate data structure used by most programmers to represent pair like data-structures are two array, and data is accessed via the same index

example: http://www-igm.univ-mlv.fr/~lecroq/string/node8.html#SECTION0080

This isn't ideal as the data should be bound together, but also turn out to be pretty cheap. Also, if your use case demands storing co-ordinates then its better to build your own data structure.

I've something like this in my library

public class Pair<First,Second>{.. }

SQL Server Management Studio missing

Try restarting your computer if you just installed SQL Server and there's no choice in the SQL Server Installation Center to install SQL Server Management Studio.

This choice (see image below) only appeared for me after I installed SQL Server, then restarted my computer:

enter image description here

Remove by _id in MongoDB console

Well, the _id is an object in your example, so you just need to pass an object

'db.test_users.remove({"_id": { "$oid" : "4d513345cc9374271b02ec6c" }})'

This should work

Edit: Added trailing paren to ensure that it compiled.

What is the difference between a schema and a table and a database?

Contrary to some of the above answers, here is my understanding based on experience with each of them:

  • MySQL: database/schema :: table
  • SQL Server: database :: (schema/namespace ::) table
  • Oracle: database/schema/user :: (tablespace ::) table

Please correct me on whether tablespace is optional or not with Oracle, it's been a long time since I remember using them.

Check if current date is between two dates Oracle SQL

SELECT to_char(emp_login_date,'DD-MON-YYYY HH24:MI:SS'),A.* 
FROM emp_log A
WHERE emp_login_date BETWEEN to_date(to_char('21-MAY-2015 11:50:14'),'DD-MON-YYYY HH24:MI:SS')
AND
to_date(to_char('22-MAY-2015 17:56:52'),'DD-MON-YYYY HH24:MI:SS') 
ORDER BY emp_login_date

How to rebase local branch onto remote master

First fetch the new master from the upstream repository, then rebase your work branch on that:

git fetch origin            # Updates origin/master
git rebase origin/master    # Rebases current branch onto origin/master

Update: Please see Paul Draper's answer for a more concise way to do the same - recent Git versions provide a simpler way to do the equivalent of the above two commands.

Clang vs GCC - which produces faster binaries?

Here are some up-to-date albeit narrow findings of mine with GCC 4.7.2 and Clang 3.2 for C++.

UPDATE: GCC 4.8.1 v clang 3.3 comparison appended below.

UPDATE: GCC 4.8.2 v clang 3.4 comparison is appended to that.

I maintain an OSS tool that is built for Linux with both GCC and Clang, and with Microsoft's compiler for Windows. The tool, coan, is a preprocessor and analyser of C/C++ source files and codelines of such: its computational profile majors on recursive-descent parsing and file-handling. The development branch (to which these results pertain) comprises at present around 11K LOC in about 90 files. It is coded, now, in C++ that is rich in polymorphism and templates and but is still mired in many patches by its not-so-distant past in hacked-together C. Move semantics are not expressly exploited. It is single-threaded. I have devoted no serious effort to optimizing it, while the "architecture" remains so largely ToDo.

I employed Clang prior to 3.2 only as an experimental compiler because, despite its superior compilation speed and diagnostics, its C++11 standard support lagged the contemporary GCC version in the respects exercised by coan. With 3.2, this gap has been closed.

My Linux test harness for current coan development processes roughly 70K sources files in a mixture of one-file parser test-cases, stress tests consuming 1000s of files and scenario tests consuming < 1K files. As well as reporting the test results, the harness accumulates and displays the totals of files consumed and the run time consumed in coan (it just passes each coan command line to the Linux time command and captures and adds up the reported numbers). The timings are flattered by the fact that any number of tests which take 0 measurable time will all add up to 0, but the contribution of such tests is negligible. The timing stats are displayed at the end of make check like this:

coan_test_timer: info: coan processed 70844 input_files.
coan_test_timer: info: run time in coan: 16.4 secs.
coan_test_timer: info: Average processing time per input file: 0.000231 secs.

I compared the test harness performance as between GCC 4.7.2 and Clang 3.2, all things being equal except the compilers. As of Clang 3.2, I no longer require any preprocessor differentiation between code tracts that GCC will compile and Clang alternatives. I built to the same C++ library (GCC's) in each case and ran all the comparisons consecutively in the same terminal session.

The default optimization level for my release build is -O2. I also successfully tested builds at -O3. I tested each configuration 3 times back-to-back and averaged the 3 outcomes, with the following results. The number in a data-cell is the average number of microseconds consumed by the coan executable to process each of the ~70K input files (read, parse and write output and diagnostics).

          | -O2 | -O3 |O2/O3|
----------|-----|-----|-----|
GCC-4.7.2 | 231 | 237 |0.97 |
----------|-----|-----|-----|
Clang-3.2 | 234 | 186 |1.25 |
----------|-----|-----|------
GCC/Clang |0.99 | 1.27|

Any particular application is very likely to have traits that play unfairly to a compiler's strengths or weaknesses. Rigorous benchmarking employs diverse applications. With that well in mind, the noteworthy features of these data are:

  1. -O3 optimization was marginally detrimental to GCC
  2. -O3 optimization was importantly beneficial to Clang
  3. At -O2 optimization, GCC was faster than Clang by just a whisker
  4. At -O3 optimization, Clang was importantly faster than GCC.

A further interesting comparison of the two compilers emerged by accident shortly after those findings. Coan liberally employs smart pointers and one such is heavily exercised in the file handling. This particular smart-pointer type had been typedef'd in prior releases for the sake of compiler-differentiation, to be an std::unique_ptr<X> if the configured compiler had sufficiently mature support for its usage as that, and otherwise an std::shared_ptr<X>. The bias to std::unique_ptr was foolish, since these pointers were in fact transferred around, but std::unique_ptr looked like the fitter option for replacing std::auto_ptr at a point when the C++11 variants were novel to me.

In the course of experimental builds to gauge Clang 3.2's continued need for this and similar differentiation, I inadvertently built std::shared_ptr<X> when I had intended to build std::unique_ptr<X>, and was surprised to observe that the resulting executable, with default -O2 optimization, was the fastest I had seen, sometimes achieving 184 msecs. per input file. With this one change to the source code, the corresponding results were these;

          | -O2 | -O3 |O2/O3|
----------|-----|-----|-----|
GCC-4.7.2 | 234 | 234 |1.00 |
----------|-----|-----|-----|
Clang-3.2 | 188 | 187 |1.00 |
----------|-----|-----|------
GCC/Clang |1.24 |1.25 |

The points of note here are:

  1. Neither compiler now benefits at all from -O3 optimization.
  2. Clang beats GCC just as importantly at each level of optimization.
  3. GCC's performance is only marginally affected by the smart-pointer type change.
  4. Clang's -O2 performance is importantly affected by the smart-pointer type change.

Before and after the smart-pointer type change, Clang is able to build a substantially faster coan executable at -O3 optimisation, and it can build an equally faster executable at -O2 and -O3 when that pointer-type is the best one - std::shared_ptr<X> - for the job.

An obvious question that I am not competent to comment upon is why Clang should be able to find a 25% -O2 speed-up in my application when a heavily used smart-pointer-type is changed from unique to shared, while GCC is indifferent to the same change. Nor do I know whether I should cheer or boo the discovery that Clang's -O2 optimization harbours such huge sensitivity to the wisdom of my smart-pointer choices.

UPDATE: GCC 4.8.1 v clang 3.3

The corresponding results now are:

          | -O2 | -O3 |O2/O3|
----------|-----|-----|-----|
GCC-4.8.1 | 442 | 443 |1.00 |
----------|-----|-----|-----|
Clang-3.3 | 374 | 370 |1.01 |
----------|-----|-----|------
GCC/Clang |1.18 |1.20 |

The fact that all four executables now take a much greater average time than previously to process 1 file does not reflect on the latest compilers' performance. It is due to the fact that the later development branch of the test application has taken on lot of parsing sophistication in the meantime and pays for it in speed. Only the ratios are significant.

The points of note now are not arrestingly novel:

  • GCC is indifferent to -O3 optimization
  • clang benefits very marginally from -O3 optimization
  • clang beats GCC by a similarly important margin at each level of optimization.

Comparing these results with those for GCC 4.7.2 and clang 3.2, it stands out that GCC has clawed back about a quarter of clang's lead at each optimization level. But since the test application has been heavily developed in the meantime one cannot confidently attribute this to a catch-up in GCC's code-generation. (This time, I have noted the application snapshot from which the timings were obtained and can use it again.)

UPDATE: GCC 4.8.2 v clang 3.4

I finished the update for GCC 4.8.1 v Clang 3.3 saying that I would stick to the same coan snaphot for further updates. But I decided instead to test on that snapshot (rev. 301) and on the latest development snapshot I have that passes its test suite (rev. 619). This gives the results a bit of longitude, and I had another motive:

My original posting noted that I had devoted no effort to optimizing coan for speed. This was still the case as of rev. 301. However, after I had built the timing apparatus into the coan test harness, every time I ran the test suite the performance impact of the latest changes stared me in the face. I saw that it was often surprisingly big and that the trend was more steeply negative than I felt to be merited by gains in functionality.

By rev. 308 the average processing time per input file in the test suite had well more than doubled since the first posting here. At that point I made a U-turn on my 10 year policy of not bothering about performance. In the intensive spate of revisions up to 619 performance was always a consideration and a large number of them went purely to rewriting key load-bearers on fundamentally faster lines (though without using any non-standard compiler features to do so). It would be interesting to see each compiler's reaction to this U-turn,

Here is the now familiar timings matrix for the latest two compilers' builds of rev.301:

coan - rev.301 results

          | -O2 | -O3 |O2/O3|
----------|-----|-----|-----|
GCC-4.8.2 | 428 | 428 |1.00 |
----------|-----|-----|-----|
Clang-3.4 | 390 | 365 |1.07 |
----------|-----|-----|------
GCC/Clang | 1.1 | 1.17|

The story here is only marginally changed from GCC-4.8.1 and Clang-3.3. GCC's showing is a trifle better. Clang's is a trifle worse. Noise could well account for this. Clang still comes out ahead by -O2 and -O3 margins that wouldn't matter in most applications but would matter to quite a few.

And here is the matrix for rev. 619.

coan - rev.619 results

          | -O2 | -O3 |O2/O3|
----------|-----|-----|-----|
GCC-4.8.2 | 210 | 208 |1.01 |
----------|-----|-----|-----|
Clang-3.4 | 252 | 250 |1.01 |
----------|-----|-----|------
GCC/Clang |0.83 | 0.83|

Taking the 301 and the 619 figures side by side, several points speak out.

  • I was aiming to write faster code, and both compilers emphatically vindicate my efforts. But:

  • GCC repays those efforts far more generously than Clang. At -O2 optimization Clang's 619 build is 46% faster than its 301 build: at -O3 Clang's improvement is 31%. Good, but at each optimization level GCC's 619 build is more than twice as fast as its 301.

  • GCC more than reverses Clang's former superiority. And at each optimization level GCC now beats Clang by 17%.

  • Clang's ability in the 301 build to get more leverage than GCC from -O3 optimization is gone in the 619 build. Neither compiler gains meaningfully from -O3.

I was sufficiently surprised by this reversal of fortunes that I suspected I might have accidentally made a sluggish build of clang 3.4 itself (since I built it from source). So I re-ran the 619 test with my distro's stock Clang 3.3. The results were practically the same as for 3.4.

So as regards reaction to the U-turn: On the numbers here, Clang has done much better than GCC at at wringing speed out of my C++ code when I was giving it no help. When I put my mind to helping, GCC did a much better job than Clang.

I don't elevate that observation into a principle, but I take the lesson that "Which compiler produces the better binaries?" is a question that, even if you specify the test suite to which the answer shall be relative, still is not a clear-cut matter of just timing the binaries.

Is your better binary the fastest binary, or is it the one that best compensates for cheaply crafted code? Or best compensates for expensively crafted code that prioritizes maintainability and reuse over speed? It depends on the nature and relative weights of your motives for producing the binary, and of the constraints under which you do so.

And in any case, if you deeply care about building "the best" binaries then you had better keep checking how successive iterations of compilers deliver on your idea of "the best" over successive iterations of your code.

Java synchronized block vs. Collections.synchronizedMap

Collections.synchronizedMap() guarantees that each atomic operation you want to run on the map will be synchronized.

Running two (or more) operations on the map however, must be synchronized in a block. So yes - you are synchronizing correctly.

how to send multiple data with $.ajax() jquery

You can create an object of key/value pairs and jQuery will do the rest for you:

$.ajax({
    ...
    data : { foo : 'bar', bar : 'foo' },
    ...
});

This way the data will be properly encoded automatically. If you do want to concoct you own string then make sure to use encodeURIComponent(): https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/encodeURIComponent

Your current code is not working because the string is not concocted properly:

'id='+ id  & 'name='+ name

should be:

'id='+ encodeURIComponent(id) + '&name='+ encodeURIComponent(name)

Sending HTML Code Through JSON

Yes, you can use json_encode to take your HTML string and escape it as necessary.

Note that in JSON, the top level item must be an array or object (that's not true anymore), it cannot just be a string. So you'll want to create an object and make the HTML string a property of the object (probably the only one), so the resulting JSON looks something like:

{"html": "<p>I'm the markup</p>"}

Using Git, show all commits that are in one branch, but not the other(s)

You can use this simple script to see commits that are not merged

#!/bin/bash
# Show commits that exists only on branch and not in current
# Usage:
#   git branch-notmerge <branchname>
#
# Setup git alias
#   git config alias.branch-notmerge [path/to/this/script]
grep -Fvf <(git log --pretty=format:'%H - %s') <(git log $1 --pretty=format:'%H - %s')

You can use also tool git-wtf that will display state of branches

Is it possible to display my iPhone on my computer monitor?

Release notes iOS 3.2 (External Display Support) and iOS 4.0 (Inherited Improvements) mentions that it should be possible to connect external displays to iOS 4.0 devices.
But you still have to jailbreak if you would mirror your iPhone screen...
Related SO Question with updates

Combination of async function + await + setTimeout

The following code works in Chrome and Firefox and maybe other browsers.

function timeout(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
}
async function sleep(fn, ...args) {
    await timeout(3000);
    return fn(...args);
}

But in Internet Explorer I get a Syntax Error for the "(resolve **=>** setTimeout..."

pip or pip3 to install packages for Python 3?

Given an activated Python 3.6 virtualenv in somepath/venv, the following aliases resolved the various issues on a macOS Sierra where pip insisted on pointing to Apple's 2.7 Python.

alias pip='python somepath/venv/lib/python3.6/site-packages/pip/__main__.py'

This didn't work so well when I had to do sudo pip as the root user doesn't know anything about my alias or the virtualenv, so I had to add an extra alias to handle this as well. It's a hack, but it works, and I know what it does:

alias sudopip='sudo somepath/venv/bin/python somepath/venv/lib/python3.6/site-packages/pip/__main__.py'

background:

pip3 did not exist to start (command not found) with and which pip would return /opt/local/Library/Frameworks/Python.framework/Versions/2.7/bin/pip, the Apple Python.

Python 3.6 was installed via macports.

After activation of the 3.6 virtualenv I wanted to work with, which python would return somepath/venv/bin/python

Somehow pip install would do the right thing and hit my virtualenv, but pip list would rattle off Python 2.7 packages.

For Python, this is batting way beneath my expectations in terms of beginner-friendliness.

Ruby: Merging variables in to a string

You can use it with your local variables, like this:

@animal = "Dog"
@action = "licks"
@second_animal = "Bird"

"The #{@animal} #{@action} the #{@second_animal}"

the output would be: "The Dog licks the Bird"

How to select the comparison of two columns as one column in Oracle

If you want to consider null values equality too, try the following

select column1, column2, 
   case
      when column1 is NULL and column2 is NULL then 'true'  
      when column1=column2 then 'true' 
      else 'false' 
   end 
from table;

Count number of rows matching a criteria

mydata$sCode == "CA" will return a boolean array, with a TRUE value everywhere that the condition is met. To illustrate:

> mydata = data.frame(sCode = c("CA", "CA", "AC"))
> mydata$sCode == "CA"
[1]  TRUE  TRUE FALSE

There are a couple of ways to deal with this:

  1. sum(mydata$sCode == "CA"), as suggested in the comments; because TRUE is interpreted as 1 and FALSE as 0, this should return the numer of TRUE values in your vector.

  2. length(which(mydata$sCode == "CA")); the which() function returns a vector of the indices where the condition is met, the length of which is the count of "CA".

Edit to expand upon what's happening in #2:

> which(mydata$sCode == "CA")
[1] 1 2

which() returns a vector identify each column where the condition is met (in this case, columns 1 and 2 of the dataframe). The length() of this vector is the number of occurences.

What does this mean? "Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM"

if you still need to use the double-colon then make sure your on PHP 5.3+

How to limit the number of selected checkboxes?

Try like this.

On change event,

$('input[type=checkbox]').on('change', function (e) {
    if ($('input[type=checkbox]:checked').length > 3) {
        $(this).prop('checked', false);
        alert("allowed only 3");
    }
});

Check this in JSFiddle

R: Print list to a text file

Here's another way using sink:

sink(sink_dir_and_file_name); print(yourList); sink()

How to check if the request is an AJAX request with PHP

You could try using a $_SESSION variable to make sure that a request was made from a browser. Otherwise, you could have the request sent through a database or file [server-side].

How to check if the given string is palindrome?

Language agnostic meta-code then...

rev = StringReverse(originalString)
return ( rev == originalString );

How to read and write xml files?

SAX parser is working differently with a DOM parser, it neither load any XML document into memory nor create any object representation of the XML document. Instead, the SAX parser use callback function org.xml.sax.helpers.DefaultHandler to informs clients of the XML document structure.

SAX Parser is faster and uses less memory than DOM parser. See following SAX callback methods :

startDocument() and endDocument() – Method called at the start and end of an XML document. startElement() and endElement() – Method called at the start and end of a document element. characters() – Method called with the text contents in between the start and end tags of an XML document element.

  1. XML file

Create a simple XML file.

<?xml version="1.0"?>
<company>
    <staff>
        <firstname>yong</firstname>
        <lastname>mook kim</lastname>
        <nickname>mkyong</nickname>
        <salary>100000</salary>
    </staff>
    <staff>
        <firstname>low</firstname>
        <lastname>yin fong</lastname>
        <nickname>fong fong</nickname>
        <salary>200000</salary>
    </staff>
</company>
  1. XML parser:

Java file Use SAX parser to parse the XML file.

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class ReadXMLFile {
    public static void main(String argv[]) {

        try {
            SAXParserFactory factory = SAXParserFactory.newInstance();
            SAXParser saxParser = factory.newSAXParser();

            DefaultHandler handler = new DefaultHandler() {
                boolean bfname = false;
                boolean blname = false;
                boolean bnname = false;
                boolean bsalary = false;

                public void startElement(String uri, String localName,String qName, 
                            Attributes attributes) throws SAXException {

                    System.out.println("Start Element :" + qName);

                    if (qName.equalsIgnoreCase("FIRSTNAME")) {
                        bfname = true;
                    }

                    if (qName.equalsIgnoreCase("LASTNAME")) {
                        blname = true;
                    }

                    if (qName.equalsIgnoreCase("NICKNAME")) {
                        bnname = true;
                    }

                    if (qName.equalsIgnoreCase("SALARY")) {
                        bsalary = true;
                    }

                }

                public void endElement(String uri, String localName,
                    String qName) throws SAXException {

                    System.out.println("End Element :" + qName);

                }

                public void characters(char ch[], int start, int length) throws SAXException {

                    if (bfname) {
                        System.out.println("First Name : " + new String(ch, start, length));
                        bfname = false;
                    }

                    if (blname) {
                        System.out.println("Last Name : " + new String(ch, start, length));
                        blname = false;
                    }

                    if (bnname) {
                        System.out.println("Nick Name : " + new String(ch, start, length));
                        bnname = false;
                    }

                    if (bsalary) {
                        System.out.println("Salary : " + new String(ch, start, length));
                        bsalary = false;
                    }

                }

            };

            saxParser.parse("c:\\file.xml", handler);

        } catch (Exception e) {
           e.printStackTrace();
        }

    }

}

Result

Start Element :company
Start Element :staff
Start Element :firstname
First Name : yong
End Element :firstname
Start Element :lastname
Last Name : mook kim
End Element :lastname
Start Element :nickname
Nick Name : mkyong
End Element :nickname
and so on...

Source(MyKong) - http://www.mkyong.com/java/how-to-read-xml-file-in-java-sax-parser/

Creating layout constraints programmatically

why can't I use a property like self.myView instead of a local variable like myView?

try using:

NSDictionaryOfVariableBindings(_view)

instead of self.view

How to replace captured groups only?

A little improvement to Matthew's answer could be a lookahead instead of the last capturing group:

.replace(/(\w+)(\d+)(?=\w+)/, "$1!NEW_ID!");

Or you could split on the decimal and join with your new id like this:

.split(/\d+/).join("!NEW_ID!");

Example/Benchmark here: https://codepen.io/jogai/full/oyNXBX

Oracle Installer:[INS-13001] Environment does not meet minimum requirements

To make @Raghavendra's answer more specific:

Once you've downloaded 2 zip files,

copy ALL the contents of "win64_11gR2_database_2of2.zip -> Database -> Stage -> Components" folder to "win64_11gR2_database_1of2.zip -> Database -> Stage -> Components" folder.

You'll still get the same warning, however, the installation will run completely without generating any errors.

sql server convert date to string MM/DD/YYYY

As of SQL Server 2012+, you can use FORMAT(value, format [, culture ])

Where the format param takes any valid standard format string or custom formatting string

Example:

SELECT FORMAT(GETDATE(), 'MM/dd/yyyy')

Further Reading:

Ajax Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource

I think setting your header to Access-Control-Allow-Origin: * would do the trick here. Had the same issue and I resolved it like that.

How to update core-js to core-js@3 dependency?

For ng9 upgraders:

npm i -g core-js@^3

..then:

npm cache clean -f

..followed by:

npm i

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2

I was running into a similar error in pywikipediabot. The .decode method is a step in the right direction but for me it didn't work without adding 'ignore':

ignore_encoding = lambda s: s.decode('utf8', 'ignore')

Ignoring encoding errors can lead to data loss or produce incorrect output. But if you just want to get it done and the details aren't very important this can be a good way to move faster.

JavaScript Editor Plugin for Eclipse

Complete the following steps in Eclipse to get plugins for JavaScript files:

  1. Open Eclipse -> Go to "Help" -> "Install New Software"
  2. Select the repository for your version of Eclipse. I have Juno so I selected http://download.eclipse.org/releases/juno
  3. Expand "Programming Languages" -> Check the box next to "JavaScript Development Tools"
  4. Click "Next" -> "Next" -> Accept the Terms of the License Agreement -> "Finish"
  5. Wait for the software to install, then restart Eclipse (by clicking "Yes" button at pop up window)
  6. Once Eclipse has restarted, open "Window" -> "Preferences" -> Expand "General" and "Editors" -> Click "File Associations" -> Add ".js" to the "File types:" list, if it is not already there
  7. In the same "File Associations" dialog, click "Add" in the "Associated editors:" section
  8. Select "Internal editors" radio at the top
  9. Select "JavaScript Viewer". Click "OK" -> "OK"

To add JavaScript Perspective: (Optional)
10. Go to "Window" -> "Open Perspective" -> "Other..."
11. Select "JavaScript". Click "OK"

To open .html or .js file with highlighted JavaScript syntax:
12. (Optional) Select JavaScript Perspective
13. Browse and Select .html or .js file in Script Explorer in [JavaScript Perspective] (Or Package Explorer [Java Perspective] Or PyDev Package Explorer [PyDev Perspective] Don't matter.)
14. Right-click on .html or .js file -> "Open With" -> "Other..."
15. Select "Internal editors"
16. Select "Java Script Editor". Click "OK" (see JavaScript syntax is now highlighted )

How to navigate through a vector using iterators? (C++)

In C++-11 you can do:

std::vector<int> v = {0, 1, 2, 3, 4, 5};
for (auto i : v)
{
   // access by value, the type of i is int
   std::cout << i << ' ';
}
std::cout << '\n';

See here for variations: https://en.cppreference.com/w/cpp/language/range-for

ASP.NET document.getElementById('<%=Control.ClientID%>'); returns null

Gotcha!

You have to use RegisterStartupScript instead of RegisterClientScriptBlock

Here My Example.

MasterPage:

<%@ Master Language="C#" AutoEventWireup="true" CodeBehind="MasterPage.master.cs"
    Inherits="prueba.MasterPage" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>

    <script type="text/javascript">

        function confirmCallBack() {
            var a = document.getElementById('<%= Page.Master.FindControl("ContentPlaceHolder1").FindControl("Button1").ClientID %>');

            alert(a.value);

        }

    </script>

    <asp:ContentPlaceHolder ID="head" runat="server">
    </asp:ContentPlaceHolder>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">
        </asp:ContentPlaceHolder>
    </div>
    </form>
</body>
</html>

WebForm1.aspx

<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPage.Master" AutoEventWireup="true"
    CodeBehind="WebForm1.aspx.cs" Inherits="prueba.WebForm1" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">

</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
<asp:Button ID="Button1" runat="server" Text="Button" />
</asp:Content>

WebForm1.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace prueba
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            ClientScript.RegisterStartupScript(this.GetType(), "js", "confirmCallBack();", true);

        }
    }
}

SQL Server Group By Month

I prefer combining DATEADD and DATEDIFF functions like this:

GROUP BY DATEADD(MONTH, DATEDIFF(MONTH, 0, Created),0)

Together, these two functions zero-out the date component smaller than the specified datepart (i.e. MONTH in this example).

You can change the datepart bit to YEAR, WEEK, DAY, etc... which is super handy.

Your original SQL query would then look something like this (I can't test it as I don't have your data set, but it should put you on the right track).

DECLARE @start [datetime] = '2010-04-01';

SELECT
    ItemID,
    UserID,
    DATEADD(MONTH, DATEDIFF(MONTH, 0, Created),0) [Month],
    IsPaid,
    SUM(Amount)
FROM LIVE L
INNER JOIN Payments I ON I.LiveID = L.RECORD_KEY
WHERE UserID = 16178
AND PaymentDate > @start

One more thing: the Month column is typed as a DateTime which is also a nice advantage if you need to further process that data or map it .NET object for example.

What does it mean if a Python object is "subscriptable" or not?

Off the top of my head, the following are the only built-ins that are subscriptable:

string:  "foobar"[3] == "b"
tuple:   (1,2,3,4)[3] == 4
list:    [1,2,3,4][3] == 4
dict:    {"a":1, "b":2, "c":3}["c"] == 3

But mipadi's answer is correct - any class that implements __getitem__ is subscriptable

ALTER TABLE to add a composite primary key

alter table table_name add primary key (col_name1, col_name2);

SQL Server Profiler - How to filter trace to only display events from one database?

Under Trace properties > Events Selection tab > select show all columns. Now under column filters, you should see the database name. Enter the database name for the Like section and you should see traces only for that database.

Can't access 127.0.0.1

In windows first check under services if world wide web publishing services is running. If not start it.

If you cannot find it switch on IIS features of windows: In 7,8,10 it is under control panel , "turn windows features on or off". Internet Information Services World Wide web services and Internet information Services Hostable Core are required. Not sure if there is another way to get it going on windows, but this worked for me for all browsers. You might need to add localhost or http:/127.0.0.1 to the trusted websites also under IE settings.

How add spaces between Slick carousel item

Yup, I have found the solution for dis issue.

  • Create one slider box with extra width from both side( Which we can use to add item space from both sides ).
  • Create Inner Item Content with proper width & margin from both sides( This should be your actual wrapper size )
  • Done

Android textview outline text

So you want a stroke around the textview? Unfortunately there is no simple way to do it with the styling. You'll have to create another view and place your textview over-top, making the parent view (the one it's on top of) just a few pixels bigger - this should create an outline.

Get values from an object in JavaScript

If you $ is defined then You can iterate

var data={"id" : 1, "second" : "abcd"};
$.each(data, function() {
  var key = Object.keys(this)[0];
  var value = this[key];
  //do something with value;
}); 

You can access it by following way If you know the values of keys

data.id

or

data["id"]

How do I put text on ProgressBar?

AVOID FLICKERING TEXT

The solution provided by Barry above is excellent, but there's is the "flicker-problem".

As soon as the Value is above zero the OnPaint will be envoked repeatedly and the text will flicker.

There is a solution to this. We do not need VisualStyles for the object since we will be drawing it with our own code.

Add the following code to the custom object Barry wrote and you will avoid the flicker:

    [DllImportAttribute("uxtheme.dll")]
    private static extern int SetWindowTheme(IntPtr hWnd, string appname, string idlist);

    protected override void OnHandleCreated(EventArgs e)
    {
        SetWindowTheme(this.Handle, "", "");
        base.OnHandleCreated(e);
    }

I did not write this myself. It found it here: https://stackoverflow.com/a/299983/1163954

I've testet it and it works.

How to pass table value parameters to stored procedure from .net code

The cleanest way to work with it. Assuming your table is a list of integers called "dbo.tvp_Int" (Customize for your own table type)

Create this extension method...

public static void AddWithValue_Tvp_Int(this SqlParameterCollection paramCollection, string parameterName, List<int> data)
{
   if(paramCollection != null)
   {
       var p = paramCollection.Add(parameterName, SqlDbType.Structured);
       p.TypeName = "dbo.tvp_Int";
       DataTable _dt = new DataTable() {Columns = {"Value"}};
       data.ForEach(value => _dt.Rows.Add(value));
       p.Value = _dt;
   }
}

Now you can add a table valued parameter in one line anywhere simply by doing this:

cmd.Parameters.AddWithValueFor_Tvp_Int("@IDValues", listOfIds);

How can I check if a Perl module is installed on my system from the command line?

What you're doing there is not recursing into directories. It is only listing the modules in the root directory of the @INC directory.

The module XML::Simple will live in one of the @INC paths under XML/Simple.pm.

What he said above to find specific modules.

CPAN explains how to find all modules here, see How to find installed modules.

Get domain name from given url

import java.net.*;
import java.io.*;

public class ParseURL {
  public static void main(String[] args) throws Exception {

    URL aURL = new URL("http://example.com:80/docs/books/tutorial"
                       + "/index.html?name=networking#DOWNLOADING");

    System.out.println("protocol = " + aURL.getProtocol()); //http
    System.out.println("authority = " + aURL.getAuthority()); //example.com:80
    System.out.println("host = " + aURL.getHost()); //example.com
    System.out.println("port = " + aURL.getPort()); //80
    System.out.println("path = " + aURL.getPath()); //  /docs/books/tutorial/index.html
    System.out.println("query = " + aURL.getQuery()); //name=networking
    System.out.println("filename = " + aURL.getFile()); ///docs/books/tutorial/index.html?name=networking
    System.out.println("ref = " + aURL.getRef()); //DOWNLOADING
  }
}

Read more

Difference between <? super T> and <? extends T> in Java

You can go through all the answers above to understand why the .add() is restricted to '<?>', '<? extends>', and partly to '<? super>'.

But here's the conclusion of it all if you want to remember it, and dont want to go exploring the answer every time:

List<? extends A> means this will accept any List of A and subclass of A. But you cannot add anything to this list. Not even objects of type A.

List<? super A> means this will accept any list of A and superclass of A. You can add objects of type A and its subclasses.

cast or convert a float to nvarchar?

Check STR. You need something like SELECT STR([Column_Name],10,0) ** This is SQL Server solution, for other servers check their docs.

Error LNK2019 unresolved external symbol _main referenced in function "int __cdecl invoke_main(void)" (?invoke_main@@YAHXZ)

This is an edge case, but you can also get this error if you are building an MFC application with CMake.

In that case, you need to add the following definitions:

ADD_DEFINITIONS(-D_AFXDLL) SET(CMAKE_MFC_FLAG 2) # or 1 if you are looking for the static library

If you are compiling with unicode, the following properties also need to be added:

set_target_properties(MyApp PROPERTIES COMPILE_DEFINITIONS _AFXDLL,_UNICODE,UNICODE,_BIND_TO_CURRENT_CRT_VERSION,_BIND_TO_CURRENT_MFC_VERSION LINK_FLAGS "/ENTRY:\"wWinMainCRTStartup\"" )

Soure: FAQ: How to use MFC with CMake

How do you run multiple programs in parallel from a bash script?

Here is a function I use in order to run at max n process in parallel (n=4 in the example):

max_children=4

function parallel {
  local time1=$(date +"%H:%M:%S")
  local time2=""

  # for the sake of the example, I'm using $2 as a description, you may be interested in other description
  echo "starting $2 ($time1)..."
  "$@" && time2=$(date +"%H:%M:%S") && echo "finishing $2 ($time1 -- $time2)..." &

  local my_pid=$$
  local children=$(ps -eo ppid | grep -w $my_pid | wc -w)
  children=$((children-1))
  if [[ $children -ge $max_children ]]; then
    wait -n
  fi
}

parallel sleep 5
parallel sleep 6
parallel sleep 7
parallel sleep 8
parallel sleep 9
wait

If max_children is set to the number of cores, this function will try to avoid idle cores.

How do I encrypt and decrypt a string in python?

Take a look at PyCrypto. It supports Python 3.2 and does exactly what you want.

From their pip website:

>>> from Crypto.Cipher import AES
>>> obj = AES.new('This is a key123', AES.MODE_CFB, 'This is an IV456')
>>> message = "The answer is no"
>>> ciphertext = obj.encrypt(message)
>>> ciphertext
'\xd6\x83\x8dd!VT\x92\xaa`A\x05\xe0\x9b\x8b\xf1'
>>> obj2 = AES.new('This is a key123', AES.MODE_CFB, 'This is an IV456')
>>> obj2.decrypt(ciphertext)
'The answer is no'

If you want to encrypt a message of an arbitrary size use AES.MODE_CFB instead of AES.MODE_CBC.

Best approach to converting Boolean object to string in java

If you are sure that your value is not null you can use third option which is

String str3 = b.toString();

and its code looks like

public String toString() {
    return value ? "true" : "false";
}

If you want to be null-safe use String.valueOf(b) which code looks like

public static String valueOf(Object obj) {
    return (obj == null) ? "null" : obj.toString();
}

so as you see it will first test for null and later invoke toString() method on your object.


Calling Boolean.toString(b) will invoke

public static String toString(boolean b) {
    return b ? "true" : "false";
}

which is little slower than b.toString() since JVM needs to first unbox Boolean to boolean which will be passed as argument to Boolean.toString(...), while b.toString() reuses private boolean value field in Boolean object which holds its state.

Using import fs from 'fs'

ES6 modules support in Node.js is fairly recent; even in the bleeding-edge versions, it is still experimental. With Node.js 10, you can start Node.js with the --experimental-modules flag, and it will likely work.

To import on older Node.js versions - or standard Node.js 10 - use CommonJS syntax:

const fs = require('fs');

How to convert Blob to String and String to Blob in java

How are you setting blob to DB? You should do:

 //imagine u have a a prepared statement like:
 PreparedStatement ps = conn.prepareStatement("INSERT INTO table VALUES (?)");
 String blobString= "This is the string u want to convert to Blob";
oracle.sql.BLOB myBlob = oracle.sql.BLOB.createTemporary(conn, false,oracle.sql.BLOB.DURATION_SESSION);
 byte[] buff = blobString.getBytes();
 myBlob.putBytes(1,buff);
 ps.setBlob(1, myBlob);
 ps.executeUpdate();

How to get Android crash logs?

If you are looking for a basic crash reporting tool, try crashlytics.

If you want a more advanced reporting tool, Checkout Gryphonet. It logs all the crashes occured along with the exact line of code that caused the crash along with automated markers that show you the steps the user took prior to the crash and more.

Good luck!

Why is char[] preferred over String for passwords?

Strings are immutable and cannot be altered once they have been created. Creating a password as a string will leave stray references to the password on the heap or on the String pool. Now if someone takes a heap dump of the Java process and carefully scans through he might be able to guess the passwords. Of course these non used strings will be garbage collected but that depends on when the GC kicks in.

On the other side char[] are mutable as soon as the authentication is done you can overwrite them with any character like all M's or backslashes. Now even if someone takes a heap dump he might not be able to get the passwords which are not currently in use. This gives you more control in the sense like clearing the Object content yourself vs waiting for the GC to do it.

check if file exists in php

file_exists checks whether a file exist in the specified path or not.

Syntax:

file_exists ( string $filename )

Returns TRUE if the file or directory specified by filename exists; FALSE otherwise.

$filename = BASE_DIR."images/a/test.jpg";
if (file_exists($filename)){
    echo "File exist.";
}else{
    echo "File does not exist.";
}

Another alternative method you can use getimagesize(), it will return 0(zero) if file/directory is not available in the specified path.

if (@getimagesize($filename)) {...}

How do I discover memory usage of my application in Android?

1) I guess not, at least not from Java.
2)

ActivityManager activityManager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
MemoryInfo mi = new MemoryInfo();
activityManager.getMemoryInfo(mi);
Log.i("memory free", "" + mi.availMem);

How to scanf only integer?

  1. You take scanf().
  2. You throw it in the bin.
  3. You use fgets() to get an entire line.
  4. You use strtol() to parse the line as an integer, checking if it consumed the entire line.
char *end;
char buf[LINE_MAX];

do {
     if (!fgets(buf, sizeof buf, stdin))
        break;

     // remove \n
     buf[strlen(buf) - 1] = 0;

     int n = strtol(buf, &end, 10);
} while (end != buf + strlen(buf));

How do I clear the previous text field value after submitting the form with out refreshing the entire page?

HTML

<form id="some_form">
<!-- some form elements -->
</form>

and jquery

$("#some_form").reset();

Set selected item of spinner programmatically

Most of the time spinner.setSelection(i); //i is 0 to (size-1) of adapter's size doesn't work. If you just call spinner.setSelection(i);

It depends on your logic.

If view is fully loaded and you want to call it from interface I suggest you to call

spinner.setAdapter(spinner_no_of_hospitals.getAdapter());
spinner.setSelection(i); // i is 0 or within adapter size

Or if you want to change between activity/fragment lifecycle, call like this

spinner.post(new Runnable() {
  @Override public void run() {
    spinner.setSelection(i);
  }
});

Why doesn't Java support unsigned ints?

The reason IMHO is because they are/were too lazy to implement/correct that mistake. Suggesting that C/C++ programmers does not understand unsigned, structure, union, bit flag... Is just preposterous.

Ether you were talking with a basic/bash/java programmer on the verge of beginning programming a la C, without any real knowledge this language or you are just talking out of your own mind. ;)

when you deal every day on format either from file or hardware you begin to question, what in the hell they were thinking.

A good example here would be trying to use an unsigned byte as a self rotating loop. For those of you who do not understand the last sentence, how on earth you call yourself a programmer.

DC

What's the best way to do a backwards loop in C/C#/C++?

While admittedly a bit obscure, I would say that the most typographically pleasing way of doing this is

for (int i = myArray.Length; i --> 0; )
{
    //do something
}

Uncaught Error: Unexpected module 'FormsModule' declared by the module 'AppModule'. Please add a @Pipe/@Directive/@Component annotation

Remove the FormsModule from Declaration:[] and Add the FormsModule in imports:[]

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    FormsModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})

getElementsByClassName not working

There are several issues:

  1. Class names (and IDs) are not allowed to start with a digit.
  2. You have to pass a class to getElementsByClassName().
  3. You have to iterate of the result set.

Example (untested):

<script type="text/javascript">
function hideTd(className){
    var elements = document.getElementsByClassName(className);
    for(var i = 0, length = elements.length; i < length; i++) {
       if( elements[i].textContent == ''){
          elements[i].style.display = 'none';
       } 
    }

  }
</script>
</head>
<body onload="hideTd('td');">
<table border="1">
  <tr>
    <td class="td">not empty</td>
  </tr>
  <tr>
    <td class="td"></td>
  </tr>
  <tr>
    <td class="td"></td>
  </tr>
</table>
</body>

Note that getElementsByClassName() is not available up to and including IE8.

Update:

Alternatively you can give the table an ID and use:

var elements = document.getElementById('tableID').getElementsByTagName('td');

to get all td elements.

To hide the parent row, use the parentNode property of the element:

elements[i].parentNode.style.display = "none";

How does the Python's range function work?

It is looping, probably the problem is in the part of the print...

If you can't find the logic where the system prints, just add the folling where you want the content out:

for i in range(len(vs)):
    print vs[i]
    print fs[i]
    print rs[i]

In Perl, how can I read an entire file into a string?

With File::Slurp:

use File::Slurp;
my $text = read_file('index.html');

Yes, even you can use CPAN.

How to access a preexisting collection with Mongoose?

Go to MongoDB website, Login > Connect > Connect Application > Copy > Paste in 'database_url' > Collections > Copy/Paste in 'collection' .

var mongoose = require("mongoose");
mongoose.connect(' database_url ');
var conn = mongoose.connection;
conn.on('error', console.error.bind(console, 'connection error:'));
conn.once('open', function () {

conn.db.collection(" collection ", function(err, collection){

    collection.find({}).toArray(function(err, data){
        console.log(data); // data printed in console
    })
});

});

Happy to Help. by RTTSS.

Installing Java on OS X 10.9 (Mavericks)

The new Mavericks (10.9) showed me the "Requesting install", but nothing happened.

The solution was to manually download and install the official Java package for OS X, which is in Java for OS X 2013-005.

Update: As mentioned in the comments below, there is a newer version of this same package:

Java for OS X 2014-001

Java for OS X 2014-001 (Correcting dead line above)

Java for OS X 2014-001 includes installation improvements, and supersedes all previous versions of Java for OS X. This package installs the same version of Java 6 included in Java for OS X 2013-005.

Hibernate Error: org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session

It's because you have open a session maybe for get data and then you forget to close it. When you delete you open session again then it becomes error.

SOLUTION: every function should open and close session

session.getTransaction.begin(); /* your operation */ session.close()

Ruby on Rails 3 Can't connect to local MySQL server through socket '/tmp/mysql.sock' on OSX

"/tmp/mysql.sock" will be created automatically when you start the MySQL server. So remember to do that before starting the rails server.

How the single threaded non blocking IO model works in Node.js

Node.js is built upon libuv, a cross-platform library that abstracts apis/syscalls for asynchronous (non-blocking) input/output provided by the supported OSes (Unix, OS X and Windows at least).

Asynchronous IO

In this programming model open/read/write operation on devices and resources (sockets, filesystem, etc.) managed by the file-system don't block the calling thread (as in the typical synchronous c-like model) and just mark the process (in kernel/OS level data structure) to be notified when new data or events are available. In case of a web-server-like app, the process is then responsible to figure out which request/context the notified event belongs to and proceed processing the request from there. Note that this will necessarily mean you'll be on a different stack frame from the one that originated the request to the OS as the latter had to yield to a process' dispatcher in order for a single threaded process to handle new events.

The problem with the model I described is that it's not familiar and hard to reason about for the programmer as it's non-sequential in nature. "You need to make request in function A and handle the result in a different function where your locals from A are usually not available."

Node's model (Continuation Passing Style and Event Loop)

Node tackles the problem leveraging javascript's language features to make this model a little more synchronous-looking by inducing the programmer to employ a certain programming style. Every function that requests IO has a signature like function (... parameters ..., callback) and needs to be given a callback that will be invoked when the requested operation is completed (keep in mind that most of the time is spent waiting for the OS to signal the completion - time that can be spent doing other work). Javascript's support for closures allows you to use variables you've defined in the outer (calling) function inside the body of the callback - this allows to keep state between different functions that will be invoked by the node runtime independently. See also Continuation Passing Style.

Moreover, after invoking a function spawning an IO operation the calling function will usually return control to node's event loop. This loop will invoke the next callback or function that was scheduled for execution (most likely because the corresponding event was notified by the OS) - this allows the concurrent processing of multiple requests.

You can think of node's event loop as somewhat similar to the kernel's dispatcher: the kernel would schedule for execution a blocked thread once its pending IO is completed while node will schedule a callback when the corresponding event has occured.

Highly concurrent, no parallelism

As a final remark, the phrase "everything runs in parallel except your code" does a decent job of capturing the point that node allows your code to handle requests from hundreds of thousands open socket with a single thread concurrently by multiplexing and sequencing all your js logic in a single stream of execution (even though saying "everything runs in parallel" is probably not correct here - see Concurrency vs Parallelism - What is the difference?). This works pretty well for webapp servers as most of the time is actually spent on waiting for network or disk (database / sockets) and the logic is not really CPU intensive - that is to say: this works well for IO-bound workloads.

How to achieve pagination/table layout with Angular.js?

The simplest way is using slice. You pipe the slice and mention the start index and end index for the part of the data you wish to display. Here is the code:
HTML

<table>
  <thead>
     ...
  </thead>
  <tbody>
     <tr *ngFor="let row of rowData | slice:startIndex:endIndex">
        ...
     </tr>
  </tbody>
</table>
<nav *ngIf="rowData" aria-label="Page navigation example">
    <ul class="pagination">
        <li class="page-item">
            <a class="page-link" (click)="updateIndex(0)" aria-label="Previous">
                <span aria-hidden="true">First</span>
            </a>
        </li>
        <li *ngFor="let i of getArrayFromNumber(rowData.length)" class="page-item">
            <a class="page-link" (click)="updateIndex(i)">{{i+1}}</a></li>

        <li class="page-item">
            <a class="page-link" (click)="updateIndex(pageNumberArray.length-1)" aria-label="Next">
                <span aria-hidden="true">Last</span>
            </a>
        </li>
    </ul>
</nav>


TypeScript

...
public rowData = data // data you want to display in table
public paginationRowCount = 100 //number of records in a page
...
getArrayFromNumber(length) {
        if (length % this.paginationRowCount === 0) {
            this.pageNumberArray = Array.from(Array(Math.floor(length / this.paginationRowCount)).keys());
        } else {
            this.pageNumberArray = Array.from(Array(Math.floor(length / this.paginationRowCount) + 1).keys());
        }
        return this.pageNumberArray;
    }

    updateIndex(pageIndex) {
        this.startIndex = pageIndex * this.paginationRowCount;
        if (this.rowData.length > this.startIndex + this.paginationRowCount) {
            this.endIndex = this.startIndex + this.paginationRowCount;
        } else {
            this.endIndex = this.rowData.length;
        }
    }

Refence for tutorial: https://www.youtube.com/watch?v=Q0jPfb9iyE0

python 3.x ImportError: No module named 'cStringIO'

From Python 3.0 changelog;

The StringIO and cStringIO modules are gone. Instead, import the io module and use io.StringIO or io.BytesIO for text and data respectively.

From the Python 3 email documentation it can be seen that io.StringIO should be used instead:

from io import StringIO
from email.generator import Generator
fp = StringIO()
g = Generator(fp, mangle_from_=True, maxheaderlen=60)
g.flatten(msg)
text = fp.getvalue()

Reference: https://docs.python.org/3/library/io.html

Software Design vs. Software Architecture

Pretty subjective but my take:

Architecture The overall design of the system including interactions with other systems, hardware requirement, overall component design, and data flow.

Design The organization and flow of a component in the overall system. This would also include the component's API for interaction with other components.

javascript: optional first argument in function

I've created a simple library for handling optional arguments with JavaScript functions, see https://github.com/ovatto/argShim. The library is developed with Node.js in mind but should be easily ported to work with e.g. browsers.

Example:

var argShim = require('argShim');
var defaultOptions = {
  myOption: 123
};

var my_function = argShim([
    {optional:'String'},
    {optional:'Object',default:defaultOptions}
  ], function(content, options) {
    console.log("content:", content, "options:", options);
  });

my_function();
my_function('str');
my_function({myOption:42});
my_function('str', {myOption:42});

Output:

content: undefined options: { myOption: 123 }
content: str options: { myOption: 123 }
content: undefined options: { myOption: 42 }
content: str options: { myOption: 42 }

The main target for the library are module interfaces where you need to be able to handle different invocations of exported module functions.

How to convert a Binary String to a base 10 integer in Java

public Integer binaryToInteger(String binary){
    char[] numbers = binary.toCharArray();
    Integer result = 0;
    int count = 0;
    for(int i=numbers.length-1;i>=0;i--){
         if(numbers[i]=='1')result+=(int)Math.pow(2, count);
         count++;
    }
    return result;
}

I guess I'm even more bored! Modified Hassan's answer to function correctly.

LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup

I got this error while I was trying to turn off precompiled headers in a Console Application Project and removing the header file stdafx.h

To fix this go to your project properties -> Linker -> SubSystem and change the value to Not Set

In your main class, use the standard C++ main function protoype that others have already mentioned :

int main(int argc, char** argv)

Batch file to split .csv file

Use the cgwin command SPLIT. Samples

To split a file every 500 lines counts:

split -l 500 [filename.ext]

by default, it adds xa,xb,xc... to filename after extension

To generate files with numbers and ending in correct extension, use following

split -l 1000 sourcefilename.ext destinationfilename -d --additional-suffix=.ext

the position of -d or -l does not matter,

  • "-d" is same as --numeric-suffixes
  • "-l" is same as --lines

For more: split --help

Easy way to build Android UI?

This is an old question, that unfortunately even several years on doesn't have a good solution. I've just ported an app from iOS (Obj C) to Android. The biggest problem was not the back end code (for many/most folks, if you can code in Obj C you can code in Java) but porting the native interfaces. What Todd said above, UI layout is still a complete pain. In my experience, the fastest wat to develop a reliable UI that supports multiple formats etc is in good 'ol HTML.

What is DOM Event delegation?

A delegate in C# is similar to a function pointer in C or C++. Using a delegate allows the programmer to encapsulate a reference to a method inside a delegate object. The delegate object can then be passed to code which can call the referenced method, without having to know at compile time which method will be invoked.

See this link --> http://www.akadia.com/services/dotnet_delegates_and_events.html

Text not wrapping in p tag

This is not an answer to the question but as I found this page while looking to an answer to a problem that I had, I want to mention the solution that I found as it cost me a lot of time. In the hope this will be useful to others:

The problem was that text in a <p> tag would not fold in the div. Eventually, I opened the inspector and noticed a 'no breaking space entity' between all the words. My editor, vi, was just showing normal blank spaces (some invisible chr, I don't know what) but I had copied pasted the text from a PDF document. The solution was to copy a blank space from within vi and replace it with a blank space. ie. :%s/ / /g where the blank to be replaced was copied from the offending text. Problem solved.

Several ports (8005, 8080, 8009) required by Tomcat Server at localhost are already in use

It occurs when others in the project are also using the same port numbers as you are using! double click tomcat server, change port numbers to anything 8585 or whatever. The code will now begin to run!

How can I play sound in Java?

This thread is rather old but I have determined an option that could prove useful.

Instead of using the Java AudioStream library you could use an external program like Windows Media Player or VLC and run it with a console command through Java.

String command = "\"C:/Program Files (x86)/Windows Media Player/wmplayer.exe\" \"C:/song.mp3\"";
try {
    Process p = Runtime.getRuntime().exec(command);
catch (IOException e) {
    e.printStackTrace();
}

This will also create a separate process that can be controlled it the program.

p.destroy();

Of course this will take longer to execute than using an internal library but there may be programs that can start up faster and possibly without a GUI given certain console commands.

If time is not of the essence then this is useful.

SQL Server SELECT LAST N Rows

DECLARE @MYVAR  NVARCHAR(100)
DECLARE @step  int
SET @step = 0;


DECLARE MYTESTCURSOR CURSOR
DYNAMIC 
FOR
SELECT col FROM [dbo].[table]
OPEN MYTESTCURSOR
FETCH LAST FROM MYTESTCURSOR INTO @MYVAR
print @MYVAR;


WHILE @step < 10
BEGIN   
    FETCH PRIOR FROM MYTESTCURSOR INTO @MYVAR
        print @MYVAR;
        SET @step = @step + 1;
END   
CLOSE MYTESTCURSOR
DEALLOCATE MYTESTCURSOR

c# razor url parameter from view

I've found the solution in this thread

@(ViewContext.RouteData.Values["parameterName"])

notifyDataSetChanged example

I recently wrote on this topic, though this post it old, I thought it will be helpful to someone who wants to know how to implement BaseAdapter.notifyDataSetChanged() step by step and in a correct way.

Please follow How to correctly implement BaseAdapter.notifyDataSetChanged() in Android or the newer blog BaseAdapter.notifyDataSetChanged().

How to resolve git status "Unmerged paths:"?

All you should need to do is:

# if the file in the right place isn't already committed:
git add <path to desired file>

# remove the "both deleted" file from the index:
git rm --cached ../public/images/originals/dog.ai

# commit the merge:
git commit

Receive result from DialogFragment

if you want to send arguments and receive the result from second fragment, you may use Fragment.setArguments to accomplish this task

static class FirstFragment extends Fragment {
    final Handler mUIHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
            case 101: // receive the result from SecondFragment
                Object result = msg.obj;
                // do something according to the result
                break;
            }
        };
    };

    void onStartSecondFragments() {
        Message msg = Message.obtain(mUIHandler, 101, 102, 103, new Object()); // replace Object with a Parcelable if you want to across Save/Restore
                                                                               // instance
        putParcelable(new SecondFragment(), msg).show(getFragmentManager().beginTransaction(), null);
    }
}

static class SecondFragment extends DialogFragment {
    Message mMsg; // arguments from the caller/FirstFragment

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onViewCreated(view, savedInstanceState);
        mMsg = getParcelable(this);
    }

    void onClickOK() {
        mMsg.obj = new Object(); // send the result to the caller/FirstFragment
        mMsg.sendToTarget();
    }
}

static <T extends Fragment> T putParcelable(T f, Parcelable arg) {
    if (f.getArguments() == null) {
        f.setArguments(new Bundle());
    }
    f.getArguments().putParcelable("extra_args", arg);
    return f;
}
static <T extends Parcelable> T getParcelable(Fragment f) {
    return f.getArguments().getParcelable("extra_args");
}

Class method decorator with self arguments?

You can't. There's no self in the class body, because no instance exists. You'd need to pass it, say, a str containing the attribute name to lookup on the instance, which the returned function can then do, or use a different method entirely.

Can Mockito stub a method without regard to the argument?

Another option is to rely on good old fashion equals method. As long as the argument in the when mock equals the argument in the code being tested, then Mockito will match the mock.

Here is an example.

public class MyPojo {

    public MyPojo( String someField ) {
        this.someField = someField;
    }

    private String someField;

    @Override
    public boolean equals( Object o ) {
        if ( this == o ) return true;
        if ( o == null || getClass() != o.getClass() ) return false;
        MyPojo myPojo = ( MyPojo ) o;
        return someField.equals( myPojo.someField );
    }

}

then, assuming you know what the value for someField will be, you can mock it like this.

when(fooDao.getBar(new MyPojo(expectedSomeField))).thenReturn(myFoo);

pros: This is more explicit then any matchers. As a reviewer of code, I keep an eye open for any in the code junior developers write, as it glances over their code's logic to generate the appropriate object being passed.

con: Sometimes the field being passed to the object is a random ID. For this case you cannot easily construct the expected argument object in your mock code.

Another possible approach is to use Mockito's Answer object that can be used with the when method. Answer lets you intercept the actual call and inspect the input argument and return a mock object. In the example below I am using any to catch any request to the method being mocked. But then in the Answer lambda, I can further inspect the Bazo argument... maybe to verify that a proper ID was passed to it. I prefer this over any by itself so that at least some inspection is done on the argument.

    Bar mockBar = //generate mock Bar.

    when(fooDao.getBar(any(Bazo.class))
    .thenAnswer(  ( InvocationOnMock invocationOnMock) -> {
        Bazo actualBazo = invocationOnMock.getArgument( 0 );

        //inspect the actualBazo here and thrw exception if it does not meet your testing requirements.
        return mockBar;
    } );

So to sum it all up, I like relying on equals (where the expected argument and actual argument should be equal to each other) and if equals is not possible (due to not being able to predict the actual argument's state), I'll resort to Answer to inspect the argument.

How do I show/hide a UIBarButtonItem?

This is long way down the answer list, but just in case somebody wants an easy copy and paste for the swift solution, here it is

func hideToolbarItem(button: UIBarButtonItem, withToolbar toolbar: UIToolbar) {
    var toolbarButtons: [UIBarButtonItem] = toolbar.items!
    toolbarButtons.removeAtIndex(toolbarButtons.indexOf(button)!)
    toolbar.setItems(toolbarButtons, animated: true)
}

func showToolbarItem(button: UIBarButtonItem, inToolbar toolbar: UIToolbar, atIndex index: Int) {
    var toolbarButtons: [UIBarButtonItem] = toolbar.items!
    if !toolbarButtons.contains(button) {
        toolbarButtons.insert(button, atIndex: index)
        toolbar.setItems(toolbarButtons, animated:true);
    }
}

Display a view from another controller in ASP.NET MVC

With this code you can obtain any controller:

var controller = DependencyResolver.Current.GetService<ControllerB>();
controller.ControllerContext = new ControllerContext(this.Request.RequestContext, 
controller);

How to replace master branch in Git, entirely, from another branch?

I found this to be the best way of doing this (I had an issue with my server not letting me delete).

On the server that hosts the origin repository, type the following from a directory inside the repository:

git config receive.denyDeleteCurrent ignore

On your workstation:

git branch -m master vabandoned                 # Rename master on local
git branch -m newBranch master                  # Locally rename branch newBranch to master
git push origin :master                         # Delete the remote's master
git push origin master:refs/heads/master        # Push the new master to the remote
git push origin abandoned:refs/heads/abandoned  # Push the old master to the remote

Back on the server that hosts the origin repository:

git config receive.denyDeleteCurrent true

Credit to the author of blog post http://www.mslinn.com/blog/?p=772

What's the best way to break from nested loops in JavaScript?

Wrap that up in a function and then just return.

Is using 'var' to declare variables optional?

I just found the answer from a forum referred by one of my colleague. If you declare a variable outside a function, it's always global. No matter if you use var keyword or not. But, if you declare the variable inside a function, it has a big difference. Inside a function, if you declare the variable using var keyword, it will be local, but if you declare the variable without var keyword, it will be global. It can overwrite your previously declared variables. - See more at: http://forum.webdeveloperszone.com/question/what-is-the-difference-between-using-var-keyword-or-not-using-var-during-variable-declaration/#sthash.xNnLrwc3.dpuf

Export to CSV using jQuery and html

I am not sure if the above CSV generation code is so great as it appears to skip th cells and also did not appear to allow for commas in the value. So here is my CSV generation code that might be useful.

It does assume you have the $table variable which is a jQuery object (eg. var $table = $('#yourtable');)

$rows = $table.find('tr');

var csvData = "";

for(var i=0;i<$rows.length;i++){
                var $cells = $($rows[i]).children('th,td'); //header or content cells

                for(var y=0;y<$cells.length;y++){
                    if(y>0){
                      csvData += ",";
                    }
                    var txt = ($($cells[y]).text()).toString().trim();
                    if(txt.indexOf(',')>=0 || txt.indexOf('\"')>=0 || txt.indexOf('\n')>=0){
                        txt = "\"" + txt.replace(/\"/g, "\"\"") + "\"";
                    }
                    csvData += txt;
                }
                csvData += '\n';
 }

Handling onchange event in HTML.DropDownList Razor MVC

The way of dknaack does not work for me, I found this solution as well:

@Html.DropDownList("Chapters", ViewBag.Chapters as SelectList, 
                    "Select chapter", new { @onchange = "location = this.value;" })

where

@Html.DropDownList(controlName, ViewBag.property + cast, "Default value", @onchange event)

In the controller you can add:

DbModel db = new DbModel();    //entity model of Entity Framework

ViewBag.Chapters = new SelectList(db.T_Chapter, "Id", "Name");

C++, How to determine if a Windows Process is running?

The process handle will be signaled if it exits.

So the following will work (error handling removed for brevity):

BOOL IsProcessRunning(DWORD pid)
{
    HANDLE process = OpenProcess(SYNCHRONIZE, FALSE, pid);
    DWORD ret = WaitForSingleObject(process, 0);
    CloseHandle(process);
    return ret == WAIT_TIMEOUT;
}

Note that process ID's can be recycled - it's better to cache the handle that is returned from the CreateProcess call.

You can also use the threadpool API's (SetThreadpoolWait on Vista+, RegisterWaitForSingleObject on older platforms) to receive a callback when the process exits.

EDIT: I missed the "want to do something to the process" part of the original question. You can use this technique if it is ok to have potentially stale data for some small window or if you want to fail an operation without even attempting it. You will still have to handle the case where the action fails because the process has exited.

Reading specific XML elements from XML file

Alternatively, you can use XPath query via XPathSelectElements method:

var document = XDocument.Parse(yourXmlAsString);
var words = document.XPathSelectElements("//word[./category[text() = 'verb']]");

IntelliJ IDEA "The selected directory is not a valid home for JDK"

Because you are choosing jre dir. and not JDK dir. JDK dir. is for instance (depending on update and whether it's 64 bit or 32 bit): C:\Program Files (x86)\Java\jdk1.7.0_45 In my case it's 32 bit JDK 1.7 update 45

Find the closest ancestor element that has a specific class

Update: Now supported in most major browsers

document.querySelector("p").closest(".near.ancestor")

Note that this can match selectors, not just classes

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


For legacy browsers that do not support closest() but have matches() one can build selector-matching similar to @rvighne's class matching:

function findAncestor (el, sel) {
    while ((el = el.parentElement) && !((el.matches || el.matchesSelector).call(el,sel)));
    return el;
}

Add target="_blank" in CSS

Another way to use target="_blank" is:

onclick="this.target='_blank'"

Example:

<a href="http://www.url.com" onclick="this.target='_blank'">Your Text<a>

apache redirect from non www to www

<VirtualHost *:80>
    ServerAlias example.com
    RedirectMatch permanent ^/(.*) http://www.example.com/$1
</VirtualHost>

HTML - how can I show tooltip ONLY when ellipsis is activated

If you want to do this solely using javascript, I would do the following. Give the span an id attribute (so that it can easily be retrieved from the DOM) and place all the content in an attribute named 'content':

<span id='myDataId' style='text-overflow: ellipsis; overflow : hidden;
 white-space: nowrap; width: 71;' content='{$myData}'>${myData}</span>

Then, in your javascript, you can do the following after the element has been inserted into the DOM.

var elemInnerText, elemContent;
elemInnerText = document.getElementById("myDataId").innerText;
elemContent = document.getElementById("myDataId").getAttribute('content')
if(elemInnerText.length <= elemContent.length)
{
   document.getElementById("myDataId").setAttribute('title', elemContent); 
}

Of course, if you're using javascript to insert the span into the DOM, you could just keep the content in a variable before inserting it. This way you don't need a content attribute on the span.

There are more elegant solutions than this if you want to use jQuery.

Byte[] to InputStream or OutputStream

I'm assuming you mean that 'use' means read, but what i'll explain for the read case can be basically reversed for the write case.

so you end up with a byte[]. this could represent any kind of data which may need special types of conversions (character, encrypted, etc). let's pretend you want to write this data as is to a file.

firstly you could create a ByteArrayInputStream which is basically a mechanism to supply the bytes to something in sequence.

then you could create a FileOutputStream for the file you want to create. there are many types of InputStreams and OutputStreams for different data sources and destinations.

lastly you would write the InputStream to the OutputStream. in this case, the array of bytes would be sent in sequence to the FileOutputStream for writing. For this i recommend using IOUtils

byte[] bytes = ...;//
ByteArrayInputStream in = new ByteArrayInputStream(bytes);
FileOutputStream out = new FileOutputStream(new File(...));
IOUtils.copy(in, out);
IOUtils.closeQuietly(in);
IOUtils.closeQuietly(out);

and in reverse

FileInputStream in = new FileInputStream(new File(...));
ByteArrayOutputStream out = new ByteArrayOutputStream();
IOUtils.copy(in, out);
IOUtils.closeQuietly(in);
IOUtils.closeQuietly(out);
byte[] bytes = out.toByteArray();

if you use the above code snippets you'll need to handle exceptions and i recommend you do the 'closes' in a finally block.

How to order results with findBy() in Doctrine

$ens = $em->getRepository('AcmeBinBundle:Marks')
              ->findBy(
                 array(), 
                 array('id' => 'ASC')
               );

How to change the docker image installation directory?

For Those looking in 2020. The following is for Windows 10 Machine:

  1. In the global Actions pane of Hyper-V Manager click Hyper-V Settings…
  2. Under Virtual Hard Disks change the location from the default to your desired location.
  3. Under Virtual Machines change the location from the default to your desired location, and click apply.

enter image description here

  1. Click OK to close the Hyper-V Settings page.

console.log not working in Angular2 Component (Typescript)

The console.log should be wrapped in a function , the "default" function for every class is its constructor so it should be declared there.

import { Component } from '@angular/core';
console.log("Hello1");

 @Component({
  selector: 'hello-console',
})
    export class App {
     s: string = "Hello2";
    constructor(){
     console.log(s); 
    }

}

When and how should I use a ThreadLocal variable?

The documentation says it very well: "each thread that accesses [a thread-local variable] (via its get or set method) has its own, independently initialized copy of the variable".

You use one when each thread must have its own copy of something. By default, data is shared between threads.

JSON Stringify changes time of date because of UTC

I'm a little late but you can always overwrite the toJson function in case of a Date using Prototype like so:

Date.prototype.toJSON = function(){
    return Util.getDateTimeString(this);
};

In my case, Util.getDateTimeString(this) return a string like this: "2017-01-19T00:00:00Z"

Checking for #N/A in Excel cell from VBA code

First check for an error (N/A value) and then try the comparisation against cvErr(). You are comparing two different things, a value and an error. This may work, but not always. Simply casting the expression to an error may result in similar problems because it is not a real error only the value of an error which depends on the expression.

If IsError(ActiveWorkbook.Sheets("Publish").Range("G4").offset(offsetCount, 0).Value) Then
  If (ActiveWorkbook.Sheets("Publish").Range("G4").offset(offsetCount, 0).Value <> CVErr(xlErrNA)) Then
    'do something
  End If
End If

Refresh a page using PHP

You cannot do it in PHP. Once the page is loaded, PHP dies and is out of control.

You have a few options:

  • Use JavaScript
  • Use the refresh meta tag, <meta http-equiv="refresh" content="5">

I think that the refresh meta tag is the easiest and most convenient.

How can I include null values in a MIN or MAX?

Use the analytic function :

select case when 
    max(field) keep (dense_rank first order by datfin desc nulls first) is null then 1 
    else 0 end as flag 
from MYTABLE;

Do I need to convert .CER to .CRT for Apache SSL certificates? If so, how?

The .cer and .crt file should be interchangable as far as importing them into a keystore.

Take a look at the contents of the .cer file. Erase anything before the -----BEGIN CERTIFICATE----- line and after the -----END CERTIFICATE----- line. You'll be left with the BEGIN/END lines with a bunch of Base64-encoded stuff between them.

-----BEGIN CERTIFICATE-----
MIIDQTCCAqqgAwIBAgIJALQea21f1bVjMA0GCSqGSIb3DQEBBQUAMIG1MQswCQYD
...
pfDACIDHTrwCk5OefMwArfEkSBo/
-----END CERTIFICATE-----

Then just import it into your keyfile using keytool.

keytool -import -alias myalias -keystore my.keystore -trustcacerts -file mycert.cer

Explanation of polkitd Unregistered Authentication Agent

Policykit is a system daemon and policykit authentication agent is used to verify identity of the user before executing actions. The messages logged in /var/log/secure show that an authentication agent is registered when user logs in and it gets unregistered when user logs out. These messages are harmless and can be safely ignored.

SyntaxError: cannot assign to operator

In case it helps someone, if your variables have hyphens in them, you may see this error since hyphens are not allowed in variable names in Python and are used as subtraction operators.

Example:

my-variable = 5   # would result in 'SyntaxError: can't assign to operator'

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

You have to convert input x and y into int like below.

x=int(x)
y=int(y)

Difficulty with ng-model, ng-repeat, and inputs

how do something like:

<select ng-model="myModel($index+1)">

And in my inspector element be:

<select ng-model="myModel1">
...
<select ng-model="myModel2">

Center align with table-cell

Here is a good starting point.

HTML:

<div class="containing-table">
    <div class="centre-align">
        <div class="content"></div>
    </div>
</div>

CSS:

.containing-table {
    display: table;
    width: 100%;
    height: 400px; /* for demo only */
    border: 1px dotted blue;
}
.centre-align {
    padding: 10px;
    border: 1px dashed gray;
    display: table-cell;
    text-align: center;
    vertical-align: middle;
}
.content {
    width: 50px;
    height: 50px;
    background-color: red;
    display: inline-block;
    vertical-align: top; /* Removes the extra white space below the baseline */
}

See demo at: http://jsfiddle.net/audetwebdesign/jSVyY/

.containing-table establishes the width and height context for .centre-align (the table-cell).

You can apply text-align and vertical-align to alter .centre-align as needed.

Note that .content needs to use display: inline-block if it is to be centered horizontally using the text-align property.

Determine what attributes were changed in Rails after_save callback?

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

Rails 5.1 and greater

model.saved_changes

Rails < 5.1

model.previous_changes

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

How can I convert string to double in C++?

If it is a c-string (null-terminated array of type char), you can do something like:

#include <stdlib.h>
char str[] = "3.14159";
double num = atof(str);

If it is a C++ string, just use the c_str() method:

double num = atof( cppstr.c_str() );

atof() will convert the string to a double, returning 0 on failure. The function is documented here: http://www.cplusplus.com/reference/clibrary/cstdlib/atof.html

How to compare two strings are equal in value, what is the best method?

== checks to see if they are actually the same object in memory (which confusingly sometimes is true, since they may both be from the pool), where as equals() is overridden by java.lang.String to check each character to ensure true equality. So therefore, equals() is what you want.

How to run java application by .bat file

Sure, call the java executable.

Mine is C:\Program Files\Java\jre6\bin\java.exe, so to run it I would do

C:\Program Files\Java\jre6\bin\java.exe -jar myjarfile.jar

Chrome net::ERR_INCOMPLETE_CHUNKED_ENCODING error

I had this problem (showing ERR_INCOMPLETE_CHUNKED_ENCODING in Chrome, nothing in other browsers). Turned out the problem was my hosting provider GoDaddy adding a monitoring script at the end of my output.

https://www.godaddy.com/community/cPanel-Hosting/how-to-remove-additional-quot-monitoring-quot-script-added/td-p/62592

Android - shadow on text?

Draw 2 texts: one gray (it will be the shadow) and on top of it draw the second text (y coordinate 1px more then shadow text).

Vue component event after render

updated() should be what you're looking for:

Called after a data change causes the virtual DOM to be re-rendered and patched.

The component’s DOM will have been updated when this hook is called, so you can perform DOM-dependent operations here.

Display TIFF image in all web browser

This comes down to browser image support; it looks like the only mainstream browser that supports tiff is Safari:

http://en.wikipedia.org/wiki/Comparison_of_web_browsers#Image_format_support

Where are you getting the tiff images from? Is it possible for them to be generated in a different format?

If you have a static set of images then I'd recommend using something like PaintShop Pro to batch convert them, changing the format.

If this isn't an option then there might be some mileage in looking for a pre-written Java applet (or another browser plugin) that can display the images in the browser.

python pandas: Remove duplicates by columns A, keeping the row with the highest value in column B

Simplest solution:

To drop duplicates based on one column:

df = df.drop_duplicates('column_name', keep='last')

To drop duplicates based on multiple columns:

df = df.drop_duplicates(['col_name1','col_name2','col_name3'], keep='last')

SSL_connect: SSL_ERROR_SYSCALL in connection to github.com:443

for me, that's caused by the SSL certificate not enabled in the K8S ingress. hope this helps someone

RecyclerView vs. ListView

Advantages of RecyclerView over listview :

  1. Contains ViewHolder by default.

  2. Easy animations.

  3. Supports horizontal , grid and staggered layouts

Advantages of listView over recyclerView :

  1. Easy to add divider.

  2. Can use inbuilt arrayAdapter for simple plain lists

  3. Supports Header and footer .

  4. Supports OnItemClickListner .