Programs & Examples On #Posthoc

Is there a method that calculates a factorial in Java?

Bare naked factorials are rarely needed in practice. Most often you will need one of the following:

1) divide one factorial by another, or

2) approximated floating-point answer.

In both cases, you'd be better with simple custom solutions.

In case (1), say, if x = 90! / 85!, then you'll calculate the result just as x = 86 * 87 * 88 * 89 * 90, without a need to hold 90! in memory :)

In case (2), google for "Stirling's approximation".

Cannot find the object because it does not exist or you do not have permissions. Error in SQL Server

I've been trying to copy a table from PROD to DEV but get an error: "Cannot find the object X because it does not exist or you do not have permissions."

However, the table did exist, and I was running as sa so I did have permissions.

The problem was actually with CONTRAINTS. I'd renamed the table on DEV to be old_XXX months ago. But when I tried to copy the original one over from PROD, the Defaut Constraint names clashed.

The error message was misleading

Viewing full version tree in git

There is a very good answer to the same question.
Adding following lines to "~/.gitconfig":

lg1 = log --graph --abbrev-commit --decorate --date=relative --format=format:'%C(bold blue)%h%C(reset) - %C(bold green)(%ar)%C(reset) %C(white)%s%C(reset) %C(dim white)- %an%C(reset)%C(bold yellow)%d%C(reset)' --all
lg2 = log --graph --abbrev-commit --decorate --format=format:'%C(bold blue)%h%C(reset) - %C(bold cyan)%aD%C(reset) %C(bold green)(%ar)%C(reset)%C(bold yellow)%d%C(reset)%n''          %C(white)%s%C(reset) %C(dim white)- %an%C(reset)' --all
lg = !"git lg1"

Rendering React Components from Array of Objects presumably contains all the data, so you would need to do something like this:

var stations = [];
var stationData =;

for (var i = 0; i < stationData.length; i++) {
        <div key={stationData[i].call} className="station">
            Call: {stationData[i].call}, Freq: {stationData[i].frequency}

render() {
  return (
    <div className="stations">{stations}</div>

Or you can use map and arrow functions if you're using ES6:

const stations = =>
    <div key={} className="station">
      Call: {}, Freq: {station.frequency}

Access multiple elements of list knowing their index

Basic and not very extensive testing comparing the execution time of the five supplied answers:

def numpyIndexValues(a, b):
    na = np.array(a)
    nb = np.array(b)
    out = list(na[nb])
    return out

def mapIndexValues(a, b):
    out = map(a.__getitem__, b)
    return list(out)

def getIndexValues(a, b):
    out = operator.itemgetter(*b)(a)
    return out

def pythonLoopOverlap(a, b):
    c = [ a[i] for i in b]
    return c

multipleListItemValues = lambda searchList, ind: [searchList[i] for i in ind]

using the following input:

a = range(0, 10000000)
b = range(500, 500000)

simple python loop was the quickest with lambda operation a close second, mapIndexValues and getIndexValues were consistently pretty similar with numpy method significantly slower after converting lists to numpy arrays.If data is already in numpy arrays the numpyIndexValues method with the numpy.array conversion removed is quickest.

numpyIndexValues -> time:1.38940598 (when converted the lists to numpy arrays)
numpyIndexValues -> time:0.0193445 (using numpy array instead of python list as input, and conversion code removed)
mapIndexValues -> time:0.06477512099999999
getIndexValues -> time:0.06391049500000001
multipleListItemValues -> time:0.043773591
pythonLoopOverlap -> time:0.043021754999999995

Disable browser cache for entire ASP.NET website

Instead of rolling your own, simply use what's provided for you.

As mentioned previously, do not disable caching for everything. For instance, jQuery scripts used heavily in ASP.NET MVC should be cached. Actually ideally you should be using a CDN for those anyway, but my point is some content should be cached.

What I find works best here rather than sprinkling the [OutputCache] everywhere is to use a class:

[System.Web.Mvc.OutputCache(NoStore = true, Duration = 0, VaryByParam = "*")]
public class NoCacheController  : Controller

All of your controllers you want to disable caching for then inherit from this controller.

If you need to override the defaults in the NoCacheController class, simply specify the cache settings on your action method and the settings on your Action method will take precedence.

[OutputCache(NoStore = true, Duration = 60, VaryByParam = "*")]
public ViewResult Index()

Laravel back button

The following is a complete Blade (the templating engine Laravel uses) solution:

{!! link_to(URL::previous(), 'Cancel', ['class' => 'btn btn-default']) !!}

The options array with the class is optional, in this case it specifies the styling for a Bootstrap 3 button.

How can I control the speed that bootstrap carousel slides in items?

You need to set interval in the main DIV as data-interval tag. The it will work fine and you can give different time to different slides.

<div class="carousel" data-interval="5000">

What is the exact meaning of Git Bash?

I think the question asker is (was) thinking that git bash is a command like git init or git checkout. Git bash is not a command, it is an interface. I will also assume the asker is not a linux user because bash is very popular the unix/linux world. The name "bash" is an acronym for "Bourne Again SHell". Bash is a text-only command interface that has features which allow automated scripts to be run. A good analogy would be to compare bash to the new PowerShell interface in Windows7/8. A poor analogy (but one likely to be more readily understood by more people) is the combination of the command prompt and .BAT (batch) command files from the days of DOS and early versions of Windows.



Here is a version with configurable parameters that you can set programmatically:

<xsl:stylesheet version="1.0" xmlns:xsl="">
  <xsl:output method="text" encoding="utf-8" />

  <xsl:param name="delim" select="','" />
  <xsl:param name="quote" select="'&quot;'" />
  <xsl:param name="break" select="'&#xA;'" />

  <xsl:template match="/">
    <xsl:apply-templates select="projects/project" />

  <xsl:template match="project">
    <xsl:apply-templates />
    <xsl:if test="following-sibling::*">
      <xsl:value-of select="$break" />

  <xsl:template match="*">
    <!-- remove normalize-space() if you want keep white-space at it is --> 
    <xsl:value-of select="concat($quote, normalize-space(), $quote)" />
    <xsl:if test="following-sibling::*">
      <xsl:value-of select="$delim" />

  <xsl:template match="text()" />

check if array is empty (vba excel)

Arr1 becomes an array of 'Variant' by the first statement of your code:

Dim arr1() As Variant

Array of size zero is not empty, as like an empty box exists in real world.

If you define a variable of 'Variant', that will be empty when it is created.

Following code will display "Empty".

Dim a as Variant

If IsEmpty(a) then
  MsgBox("Not Empty")
End If

SQL Server Restore Error - Access is Denied

I had a similar problem. I tried to restore a 2005 .bak file, and i received exactly the same error. I selected the overwrite option as well to no avail.

my solution was to grant the SQL user access to the directory in question, by going to the folder and editing the access rights through the property screen.

JFrame Exit on close Java

If you're using a Frame (Class Extends Frame) you'll not get the


How to remove outliers from a dataset

data_clean <- data[data$attribute >=x[1] & data$attribute<=x[2],]

I find this very easy to remove outliers. In the above example I am just extracting 2 percentile to 98 percentile of attribute values.

How to check if activity is in foreground or in visible background?

That's exactly the difference between onPause and onStop events of the activity as described in the Activity class documentation.

If I understand you correctly, what you want to do is call finish() from your activity onStop to terminate it. See the attached image of the Activity Lifecycle Demo App. This is how it looks like when Activity B is launched from Activity A. The order of events is from bottom to top so you can see that Activity A onStop is called after Activity B onResume was already called.

Activity lifecycle demo

In case a dialog is shown your activity is dimmed in the background and only onPause is called.

Can I get a patch-compatible output from git-diff?

Just use -p1: you will need to use -p0 in the --no-prefix case anyway, so you can just leave out the --no-prefix and use -p1:

$ git diff > save.patch
$ patch -p1 < save.patch

$ git diff --no-prefix > save.patch
$ patch -p0 < save.patch

Bootstrap 3 : Vertically Center Navigation Links when Logo Increasing The Height of Navbar

I found that you don't necessarily need the text vertically centred, it also looks good near the bottom of the row, it's only when it's at the top (or above centre?) that it looks wrong. So I went with this to push the links to the bottom of the row:

.navbar-brand {
    min-height: 80px;

@media (min-width: 768px) {
    #navbar-collapse {
        position: absolute;
        bottom: 0px;
        left: 250px;

My brand image is SVG and I used height: 50px; width: auto which makes it about 216px wide. It spilled out of its container vertically so I added the min-height: 80px; to make room for it plus bootstrap's 15px margins. Then I tweaked the navbar-collapse's left setting until it looked right.

Using quotation marks inside quotation marks

I'm surprised nobody has mentioned explicit conversion flag yet

>>> print('{!r}'.format('a word that needs quotation marks'))
'a word that needs quotation marks'

The flag !r is a shorthand of the repr() built-in function1. It is used to print the object representation object.__repr__() instead of object.__str__().

There is an interesting side-effect though:

>>> print("{!r} \t {!r} \t {!r} \t {!r}".format("Buzz'", 'Buzz"', "Buzz", 'Buzz'))
"Buzz'"      'Buzz"'     'Buzz'      'Buzz'

Notice how different composition of quotation marks are handled differenty so that it fits a valid string representation of a Python object 2.

1 Correct me if anybody knows otherwise.

2 The question's original example " "word" " is not a valid representation in Python

How can I generate UUID in C#

Here is a client side "sequential guid" solution.

using System;
using System.Runtime.InteropServices;

namespace MyCompany.MyTechnology.Framework.CrossDomain.GuidExtend
    public static class Guid


        Original Reference for Code:


        [DllImport("rpcrt4.dll", SetLastError = true)]
        static extern int UuidCreateSequential(out System.Guid guid);

        public static System.Guid NewGuid()
            return CreateSequentialUuid();

        public static System.Guid CreateSequentialUuid()
            const int RPC_S_OK = 0;
            System.Guid g;
            int hr = UuidCreateSequential(out g);
            if (hr != RPC_S_OK)
                throw new ApplicationException("UuidCreateSequential failed: " + hr);
            return g;


        Text From URL above:

        UuidCreateSequential (rpcrt4)

        Type a page name and press Enter. You'll jump to the page if it exists, or you can create it if it doesn't.
        To create a page in a module other than rpcrt4, prefix the name with the module name and a period.
        . Summary
        Creates a new UUID 
        C# Signature:
        [DllImport("rpcrt4.dll", SetLastError=true)]
        static extern int UuidCreateSequential(out Guid guid);

        VB Signature:
        Declare Function UuidCreateSequential Lib "rpcrt4.dll" (ByRef id As Guid) As Integer

        User-Defined Types:

        Microsoft changed the UuidCreate function so it no longer uses the machine's MAC address as part of the UUID. Since CoCreateGuid calls UuidCreate to get its GUID, its output also changed. If you still like the GUIDs to be generated in sequential order (helpful for keeping a related group of GUIDs together in the system registry), you can use the UuidCreateSequential function.

        CoCreateGuid generates random-looking GUIDs like these:


        UuidCreateSequential generates sequential GUIDs like these:


        Here is a summary of the differences in the output of UuidCreateSequential:

        The last six bytes reveal your MAC address 
        Several GUIDs generated in a row are sequential 
        Tips & Tricks:
        Please add some!

        Sample Code in C#:
        static Guid UuidCreateSequential()
           const int RPC_S_OK = 0;
           Guid g;
           int hr = UuidCreateSequential(out g);
           if (hr != RPC_S_OK)
             throw new ApplicationException
               ("UuidCreateSequential failed: " + hr);
           return g;

        Sample Code in VB:
        Sub Main()
           Dim myId As Guid
           Dim code As Integer
           code = UuidCreateSequential(myId)
           If code <> 0 Then
             Console.WriteLine("UuidCreateSequential failed: {0}", code)
           End If
        End Sub



Keywords: CreateSequentialUUID SequentialUUID

Typescript es6 import module "File is not a module error"

In addition to A. Tim's answer there are times when even that doesn't work, so you need to:

  1. Rewrite the import string, using the intellisense. Sometimes this fixes the issue
  2. Restart VS Code

CSS: center element within a <div> element

Assign text-align: center; to the parent and display: inline-block; to the div.

How to view user privileges using windows cmd?

For Windows Server® 2008, Windows 7, Windows Server 2003, Windows Vista®, or Windows XP run "control userpasswords2"

  • Click the Start button, then click Run (Windows XP, Server 2003 or below)

  • Type control userpasswords2 and press Enter on your keyboard.

Note: For Windows 7 and Windows Vista, this command will not run by typing it in the Serach box on the Start Menu - it must be run using the Run option. To add the Run command to your Start menu, right-click on it and choose the option to customize it, then go to the Advanced options. Check to option to add the Run command.

You will see a window of user details!

Hibernate Criteria Query to get specific columns

You can use multiselect function for this.

   CriteriaBuilder cb=session.getCriteriaBuilder();
            CriteriaQuery<Object[]> cquery=cb.createQuery(Object[].class);
            Root<Car> root=cquery.from(User.class);
            Query<Object[]> q=session.createQuery(cquery);
            List<Object[]> list=q.getResultList();
            System.out.println("id        Name");
            for (Object[] objects : list) {
                System.out.println(objects[0]+"        "+objects[1]);

This is supported by hibernate 5. createCriteria is deprecated in further version of hibernate. So you can use criteria builder instead.

Log all requests from the python-requests module

I'm using a logger_config.yaml file to configure my logging, and to get those logs to show up, all I had to do was to add a disable_existing_loggers: False to the end of it.

My logging setup is rather extensive and confusing, so I don't even know a good way to explain it here, but if someone's also using a YAML file to configure their logging, this might help.

Selecting/excluding sets of columns in pandas

Also have a look into the built-in DataFrame.filter function.

Minimalistic but greedy approach (sufficient for the given df):


Conservative/lazy approach (exact matches only):


Conservative and generic:

exclude_cols = ['B','C']

Efficient way to apply multiple filters to pandas DataFrame or Series

Chaining conditions creates long lines, which are discouraged by pep8. Using the .query method forces to use strings, which is powerful but unpythonic and not very dynamic.

Once each of the filters is in place, one approach is

import numpy as np
import functools
def conjunction(*conditions):
    return functools.reduce(np.logical_and, conditions)

c_1 = data.col1 == True
c_2 = data.col2 < 64
c_3 = data.col3 != 4

data_filtered = data[conjunction(c1,c2,c3)]

np.logical operates on and is fast, but does not take more than two arguments, which is handled by functools.reduce.

Note that this still has some redundancies: a) shortcutting does not happen on a global level b) Each of the individual conditions runs on the whole initial data. Still, I expect this to be efficient enough for many applications and it is very readable.

You can also make a disjunction (wherein only one of the conditions needs to be true) by using np.logical_or instead:

import numpy as np
import functools
def disjunction(*conditions):
    return functools.reduce(np.logical_or, conditions)

c_1 = data.col1 == True
c_2 = data.col2 < 64
c_3 = data.col3 != 4

data_filtered = data[disjunction(c1,c2,c3)]

How to change Visual Studio 2012,2013 or 2015 License Key?

To see what's inside these HKCR\Licenses use API Monitor v2

API-Filter find 

        ^-Enable all from Advapi32.dll

        ^- Enable all from Crypt32.dll
         + Breakpoint / after Call

sample data that'll come out from CryptUnprotectData:

HKEY_CLASSES_ROOT\Licenses\4D8CFBCB-2F6A-4AD2-BABF-10E28F6F2C8F\07078  [length 0x1C6 (0454.) ]
    00322-20000-00000-AA450                 <- PID2
    7d3cbcbb-90b1-411f-9981-6e28039a9b82    <- Ver
    7C3WXN74-VRMXH-J8X3H-M8F7W-CPQB8        <- PID3

HKEY_CLASSES_ROOT\Licenses\4D8CFBCB-2F6A-4AD2-BABF-10E28F6F2C8F\0bcad  [length 0xbcad (0534.) ]

    0000  00000025 ffffffff 7fffffff   07064. 00000007   07078. 00000007 ffffffff
    0020  7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff
    0040  7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff
    0060  7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff
    0080  7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff
    00a0  7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff
    00c0  7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff
    00e0  7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff
    0100  7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff 7fffffff ffffffff
    0120  7fffffff ffffffff 7fffffff 10.2015. c2a6 11.
    0134                             ^installation date^

Useful here is maybe the Installation timestamp (11.10.2015 here ) Change this would required to call 'CryptProtectData'. Doing so needs some efforts like written a small program OR stop with ollydebug at this place and manually 'crafting' a CryptProtectData call ...

Note: In this example I'm using Microsoft® Visual Studio 2015

-> For a quick'n'dirty sneak into an expired VS I recommend to read this post. However that's just good for occasional use, till you get all the sign up and login crap properly done again ;)

Okay the real meat is here:
%LOCALAPPDATA%\Microsoft\VisualStudio\14.0\Licenses\ ^- This path comes from HKCU\Software\Microsoft\VisualStudio\14.0\Licenses\715f10eb-9e99-11d2-bfc2-00c04f990235\1


-after some Base64 decoding:

        00000000   30 82 06 41 30 82 04 29  A0 03 02 01 02 02 13 5A   0‚ A0‚ )       Z
        00000010   00 00 BC CB 23 AC 52 9C  E8 93 F9 0A 00 01 00 00     ¼Ë#¬Rœè“ù     
        00000020   BC CB 30 0D 06 09 2A 86  48 86 F7 0D 01 01 0B 05   ¼Ë0   *†H†÷     
        00000030   00 30 81 8B 31 0B 30 09  06 03 55 04 06 13 02 55    0 ‹1 0   U    U
        00000040   53 31 13 30 11 06 03 55  04 08 13 0A 57 61 73 68   S1 0   U    Wash
        00000050   69 6E 67 74 6F 6E 31 10  30 0E 06 03 55 04 07 13   ington1 0   U   
        00000060   07 52 65 64 6D 6F 6E 64  31 1E 30 1C 06 03 55 04    Redmond1 0   U 
        00000070   0A 13 15 4D 69 63 72 6F  73 6F 66 74 20 43 6F 72      Microsoft Cor
        00000080   70 6F 72 61 74 69 6F 6E  31 15 30 13 06 03 55 04   poration1 0   U 
        00000090   0B 13 0C 4D 69 63 72 6F  73 6F 66 74 20 49 54 31      Microsoft IT1
        000000A0   1E 30 1C 06 03 55 04 03  13 15 4D 69 63 72 6F 73    0   U    Micros
        000000B0   6F 66 74 20 49 54 20 53  53 4C 20 53 48 41 32 30   oft IT SSL SHA20
        000000C0   1E 17 0D 31 35 30 33 30  35 32 31 32 39 35 36 5A      150305212956Z
        000000D0   17 0D 31 37 30 33 30 34  32 31 32 39 35 36 5A 30     170304212956Z0
        000000E0   25 31 23 30 21 06 03 55  04 03 13 1A 61 70 70 2E   %1#0!  U    app.
        000000F0   76 73 73 70 73 2E 76 69  73 75 61 6C 73 74 75 64   vssps.visualstud
        00000100   69 6F 2E 63 6F 6D 30 82  01 22 30 0D 06 09 2A 86   io.com0‚ "0   *†
        000002B0   6E 86 36 68 74 74 70 3A  2F 2F 6D 73 63 72 6C 2E   n†6http://mscrl.
        000002C0   6D 69 63 72 6F 73 6F 66  74 2E 63 6F 6D 2F 70 6B
        000002D0   69 2F 6D 73 63 6F 72 70  2F 63 72 6C 2F 6D 73 69   i/mscorp/crl/msi
        000002E0   74 77 77 77 32 2E 63 72  6C 86 34 68 74 74 70 3A   twww2.crl†4http:
        000002F0   2F 2F 63 72 6C 2E 6D 69  63 72 6F 73 6F 66 74 2E   //
        00000300   63 6F 6D 2F 70 6B 69 2F  6D 73 63 6F 72 70 2F 63   com/pki/mscorp/c
        00000310   72 6C 2F 6D 73 69 74 77  77 77 32 2E 63 72 6C 30   rl/msitwww2.crl0
        00000320   70 06 08 2B 06 01 05 05  07 01 01 04 64 30 62 30   p  +        d0b0
        00000330   3C 06 08 2B 06 01 05 05  07 30 02 86 30 68 74 74   <  +     0 †0htt
        00000340   70 3A 2F 2F 77 77 77 2E  6D 69 63 72 6F 73 6F 66   p://www.microsof
        00000350   74 2E 63 6F 6D 2F 70 6B  69 2F 6D 73 63 6F 72 70
        00000360   2F 6D 73 69 74 77 77 77  32 2E 63 72 74 30 22 06   /msitwww2.crt0" 
        00000370   08 2B 06 01 05 05 07 30  01 86 16 68 74 74 70 3A    +     0 † http:
        00000380   2F 2F 6F 63 73 70 2E 6D  73 6F 63 73 70 2E 63 6F   //
        00000390   6D 30 4E 06 03 55 1D 20  04 47 30 45 30 43 06 09   m0N  U   G0E0C  
        000003A0   2B 06 01 04 01 82 37 2A  01 30 36 30 34 06 08 2B   +    ‚7* 0604  +
        000003B0   06 01 05 05 07 02 01 16  28 68 74 74 70 3A 2F 2F           (http://
        000003C0   77 77 77 2E 6D 69 63 72  6F 73 6F 66 74 2E 63 6F
        000003D0   6D 2F 70 6B 69 2F 6D 73  63 6F 72 70 2F 63 70 73   m/pki/mscorp/cps
        000003E0   00 30 27 06 09 2B 06 01  04 01 82 37 15 0A 04 1A    0'  +    ‚7    
        000003F0   30 18 30 0A 06 08 2B 06  01 05 05 07 03 01 30 0A   0 0   +       0 
        00000400   06 08 2B 06 01 05 05 07  03 02 30 25 06 03 55 1D     +       0%  U 
        00000410   11 04 1E 30 1C 82 1A 61  70 70 2E 76 73 73 70 73      0 ‚ app.vssps
        00000420   2E 76 69 73 75 61 6C 73  74 75 64 69 6F 2E 63 6F
        00000430   6D 30 0D 06 09 2A 86 48  86 F7 0D 01 01 0B 05 00   m0   *†H†÷      
        ...                                                U

Seems M$ is using JSON Web Token (JWT) to wrap in license data. I guess inside CertificateBytes will be somehow the payload - you're email and other details.

So far for the rough overview what's the data inside.

For more wishes get ILSpy + Reflexil (<- to changes/correct little things!) and then 'browser&correct' files like c:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE**Microsoft.VisualStudio.Licensing.dll** or check out 'Microsoft.VisualStudio.Services.WebApi.dll'

How to restart counting from 1 after erasing table in MS Access?

I am going to Necro this topic.

Starting around , you can execute Data Definition Queries (DDQ) through Macro's

Data Definition Query


  1. Save the DDQ, with your values
  2. Create a Macro with the appropriate logic either before this or after.
  3. To execute this DDQ:
    • Add an Open Query action
    • Define the name of the DDQ in the Query Name field; View and Data Mode settings are not relevant and can leave the default values


  1. This will reset the AutoNumber Counter to 1
  2. Any Referential Integrity will be summarily destroyed


  • Use this for Staging tables
    • these are tables that are never intended to persist the data they temporarily contain.
    • The data contained is only there until additional cleaning actions have been performed and stored in the appropriate table(s).
    • Once cleaning operations have been performed and the data is no longer needed, these tables are summarily purged of any data contained.
  • Import Tables
    • These are very similar to Staging Tables but tend to only have two columns: ID and RowValue
    • Since these are typically used to import RAW data from a general file format (TXT, RTF, CSV, XML, etc.), the data contained does not persist past the processing lifecycle

Regular expression for excluding special characters

I would just white list the characters.


Building a black list is equally simple with regex but you might need to add much more characters - there are a lot of Chinese symbols in unicode ... ;)


The expression [^(many characters here)] just matches any character that is not listed.

What Are Some Good .NET Profilers?

The current release of SharpDevelop (3.1.1) has a nice integrated profiler. It's quite fast, and integrates very well into the SharpDevelop IDE and its NUnit runner. Results are displayed in a flexible Tree/List style (use LINQ to create your own selection). Doubleclicking the displayed method jumps directly into the source code.

How can I use a DLL file from Python?

For ease of use, ctypes is the way to go.

The following example of ctypes is from actual code I've written (in Python 2.5). This has been, by far, the easiest way I've found for doing what you ask.

import ctypes

# Load DLL into memory.

hllDll = ctypes.WinDLL ("c:\\PComm\\ehlapi32.dll")

# Set up prototype and parameters for the desired function call.

hllApiProto = ctypes.WINFUNCTYPE (
    ctypes.c_int,      # Return type.
    ctypes.c_void_p,   # Parameters 1 ...
    ctypes.c_void_p)   # ... thru 4.
hllApiParams = (1, "p1", 0), (1, "p2", 0), (1, "p3",0), (1, "p4",0),

# Actually map the call ("HLLAPI(...)") to a Python name.

hllApi = hllApiProto (("HLLAPI", hllDll), hllApiParams)

# This is how you can actually call the DLL function.
# Set up the variables and call the Python name with them.

p1 = ctypes.c_int (1)
p2 = ctypes.c_char_p (sessionVar)
p3 = ctypes.c_int (1)
p4 = ctypes.c_int (0)
hllApi (ctypes.byref (p1), p2, ctypes.byref (p3), ctypes.byref (p4))

The ctypes stuff has all the C-type data types (int, char, short, void*, and so on) and can pass by value or reference. It can also return specific data types although my example doesn't do that (the HLL API returns values by modifying a variable passed by reference).

In terms of the specific example shown above, IBM's EHLLAPI is a fairly consistent interface.

All calls pass four void pointers (EHLLAPI sends the return code back through the fourth parameter, a pointer to an int so, while I specify int as the return type, I can safely ignore it) as per IBM's documentation here. In other words, the C variant of the function would be:

int hllApi (void *p1, void *p2, void *p3, void *p4)

This makes for a single, simple ctypes function able to do anything the EHLLAPI library provides, but it's likely that other libraries will need a separate ctypes function set up per library function.

The return value from WINFUNCTYPE is a function prototype but you still have to set up more parameter information (over and above the types). Each tuple in hllApiParams has a parameter "direction" (1 = input, 2 = output and so on), a parameter name and a default value - see the ctypes doco for details

Once you have the prototype and parameter information, you can create a Python "callable" hllApi with which to call the function. You simply create the needed variable (p1 through p4 in my case) and call the function with them.

curl posting with header application/x-www-form-urlencoded

Try something like:


$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/x-www-form-urlencoded'));   
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_data);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); 
$result = curl_exec($ch);

echo $result;

What is the difference between String.slice and String.substring?

slice() works like substring() with a few different behaviors.

Syntax: string.slice(start, stop);
Syntax: string.substring(start, stop);

What they have in common:

  1. If start equals stop: returns an empty string
  2. If stop is omitted: extracts characters to the end of the string
  3. If either argument is greater than the string's length, the string's length will be used instead.

Distinctions of substring():

  1. If start > stop, then substring will swap those 2 arguments.
  2. If either argument is negative or is NaN, it is treated as if it were 0.

Distinctions of slice():

  1. If start > stop, slice() will return the empty string. ("")
  2. If start is negative: sets char from the end of string, exactly like substr() in Firefox. This behavior is observed in both Firefox and IE.
  3. If stop is negative: sets stop to: string.length – Math.abs(stop) (original value), except bounded at 0 (thus, Math.max(0, string.length + stop)) as covered in the ECMA specification.

Source: Rudimentary Art of Programming & Development: Javascript: substr() v.s. substring()

What is declarative programming?

It's a method of programming based around describing what something should do or be instead of describing how it should work.

In other words, you don't write algorithms made of expressions, you just layout how you want things to be. Two good examples are HTML and WPF.

This Wikipedia article is a good overview:

How do you serve a file for download with AngularJS or Javascript?

Just click the button to download using following code.

in html

<a class="btn" ng-click="saveJSON()" ng-href="{{ url }}">Export to JSON</a>

In controller

$scope.saveJSON = function () {_x000D_
   $scope.toJSON = '';_x000D_
   $scope.toJSON = angular.toJson($;_x000D_
   var blob = new Blob([$scope.toJSON], { type:"application/json;charset=utf-8;" });   _x000D_
   var downloadLink = angular.element('<a></a>');_x000D_
                        downloadLink.attr('download', 'fileName.json');_x000D_

Run .php file in Windows Command Prompt (cmd)

If running Windows 10:

  1. Open the start menu
  2. Type path
  3. Click Edit the system environment variables (usually, it's the top search result) and continue on step 6 below.

If on older Windows:

  1. Show Desktop.

  2. Right Click My Computer shortcut in the desktop.

  3. Click Properties.

  4. You should see a section of control Panel - Control Panel\System and Security\System.

  5. Click Advanced System Settings on the Left menu.

  6. Click Enviornment Variables towards the bottom of the System Properties window.

  7. Select PATH in the user variables list.

  8. Append your PHP Path (C:\myfolder\php) to your PATH variable, separated from the already existing string by a semi colon.

  9. Click OK

  10. Open your "cmd"

  11. Type PATH, press enter

  12. Make sure that you see your PHP folder among the list.

That should work.

Note: Make sure that your PHP folder has the php.exe. It should have the file type CLI. If you do not have the php.exe, go ahead and check the installation guidelines at - - and download the installation file from there.

Delete all lines starting with # or ; in Notepad++

Maybe you should try


^ matches the beggining, $ the end.

Doctrine and LIKE query

you can also do it like that :

$ver = $em->getRepository('GedDocumentBundle:version')->search($val);

$tail = sizeof($ver);

How to select following sibling/xml tag using xpath

How would I accomplish the nextsibling and is there an easier way of doing this?

You may use:


but I'd rather use directly:

tr[td[@class='name'] ='Brand']/td[@class='desc']

This assumes that:

  1. The context node, against which the XPath expression is evaluated is the parent of all tr elements -- not shown in your question.

  2. Each tr element has only one td with class attribute valued 'name' and only one td with class attribute valued 'desc'.

How to find file accessed/created just few minutes ago

If you know the file is in your current directory, I would use:

ls -lt | head

This lists your most recently modified files and directories in order. In fact, I use it so much I have it aliased to 'lh'.

How to set the value of a hidden field from a controller in mvc

Please try using following way.

@Html.Hidden("hdnFlag",(object) Convert.ToInt32(ViewBag.page_Count))

How to randomly select rows in SQL?

This is an old question, but attempting to apply a new field (either NEWID() or ORDER BY rand()) to a table with a large number of rows would be prohibitively expensive. If you have incremental, unique IDs (and do not have any holes) it will be more efficient to calculate the X # of IDs to be selected instead of applying a GUID or similar to every single row and then taking the top X # of.

DECLARE @minValue int;
DECLARE @maxValue int;
SELECT @minValue = min(id), @maxValue = max(id) from [TABLE];

DECLARE @randomId1 int, @randomId2 int, @randomId3 int, @randomId4 int, @randomId5 int
SET @randomId1 = ((@maxValue + 1) - @minValue) * Rand() + @minValue
SET @randomId2 = ((@maxValue + 1) - @minValue) * Rand() + @minValue
SET @randomId3 = ((@maxValue + 1) - @minValue) * Rand() + @minValue
SET @randomId4 = ((@maxValue + 1) - @minValue) * Rand() + @minValue
SET @randomId5 = ((@maxValue + 1) - @minValue) * Rand() + @minValue

--select @maxValue as MaxValue, @minValue as MinValue
--  , @randomId1 as SelectedId1
--  , @randomId2 as SelectedId2
--  , @randomId3 as SelectedId3
--  , @randomId4 as SelectedId4
--  , @randomId5 as SelectedId5

select * from [TABLE] el
where in (@randomId1, @randomId2, @randomId3, @randomId4, @randomId5)

If you wanted to select many more rows I would look into populating a #tempTable with an ID and a bunch of rand() values then using each rand() value to scale to the min-max values. That way you do not have to define all of the @randomId1...n parameters. I've included an example below using a CTE to populate the initial table.

DECLARE @NumItems int = 100;

DECLARE @minValue int;
DECLARE @maxValue int;
SELECT @minValue = min(id), @maxValue = max(id) from [TABLE];
DECLARE @range int = @maxValue+1 - @minValue;

with cte (n) as (
   select 1 union all
   select n+1 from cte
   where n < @NumItems
select cast( @range * rand(cast(newid() as varbinary(100))) + @minValue as int) tp
into #Nt
from cte;

select * from #Nt ntt
inner join [TABLE] i on =;

drop table #Nt;

What is the difference between a static method and a non-static method?

Well, more technically speaking, the difference between a static method and a virtual method is the way the are linked.

A traditional "static" method like in most non OO languages gets linked/wired "statically" to its implementation at compile time. That is, if you call method Y() in program A, and link your program A with library X that implements Y(), the address of X.Y() is hardcoded to A, and you can not change that.

In OO languages like JAVA, "virtual" methods are resolved "late", at run-time, and you need to provide an instance of a class. So in, program A, to call virtual method Y(), you need to provide an instance, B.Y() for example. At runtime, every time A calls B.Y() the implementation called will depend on the instance used, so B.Y() , C.Y() etc... could all potential provide different implementations of Y() at runtime.

Why will you ever need that? Because that way you can decouple your code from the dependencies. For example, say program A is doing "draw()". With a static language, thats it, but with OO you will do B.draw() and the actual drawing will depend on the type of object B, which, at runtime, can change to square a circle etc. That way your code can draw multiple things with no need to change, even if new types of B are provided AFTER the code was written. Nifty -

Rails find_or_create_by more than one attribute?

By passing a block to find_or_create, you can pass additional parameters that will be added to the object if it is created new. This is useful if you are validating the presence of a field that you aren't searching by.


class GroupMember < ActiveRecord::Base
    validates_presence_of :name


GroupMember.where(:member_id => 4, :group_id => 7).first_or_create { |gm| = "John Doe" }

will create a new GroupMember with the name "John Doe" if it doesn't find one with member_id 4 and group_id 7

jQuery Validation using the class instead of the name value

Here's the solution using jQuery:

    $().ready(function () {
        $(".checkBox").each(function (item) {
            $(this).rules("add", {
                required: true,

How to create a hidden <img> in JavaScript?

You can hide an image using javascript like this:

document.images['imageName'].style.visibility = hidden;

If that isn't what you are after, you need to explain yourself more clearly.

jQuery - If element has class do this

First, you're missing some parentheses in your conditional:

if ($("#about").hasClass("opened")) {
  $("#about").animate({right: "-700px"}, 2000);

But you can also simplify this to:


If #about doesn't have the opened class, it won't animate.

If the problem is with the animation itself, we'd need to know more about your element positioning (absolute? absolute inside relative parent? does the parent have layout?)

Most efficient way to remove special characters from string

I agree with this code sample. The only different it I make it into Extension Method of string type. So that you can use it in a very simple line or code:

string test = "abc@#$123";

Thank to Guffa for your experiment.

public static class MethodExtensionHelper
    public static string RemoveSpecialCharacters(this string str)
            StringBuilder sb = new StringBuilder();
            foreach (char c in str)
                if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_')
            return sb.ToString();

MySQL Select Multiple VALUES

Try this -

 select * from table where id in (3,4) or [name] in ('andy','paul');

How to debug a stored procedure in Toad?

Basic Steps to Debug a Procedure in Toad

  1. Load your Procedure in Toad Editor.
  2. Put debug point on the line where you want to debug.See the first screenshot.
  3. Right click on the editor Execute->Execute PLSQL(Debugger).See the second screeshot.
  4. A window opens up,you need to select the procedure from the left side and pass parameters for that procedure and then click Execute.See the third screenshot.
  5. Now start your debugging check Debug-->Step Over...Add Watch etc.

Reference:Toad Debugger


Execute In Debug


When restoring a backup, how do I disconnect all active connections?

None of these were working for me, couldn't delete or disconnect current users. Also couldn't see any active connections to the DB. Restarting SQL Server (Right click and select Restart) allowed me to do it.

Setting up connection string in ASP.NET to SQL SERVER

Try this for your connection string.

 Data Source=myServerAddress;Initial Catalog=myDataBase;Integrated Security=SSPI;
 User ID=myDomain\myUsername;Password=myPassword;

Jquery insert new row into table at a certain index

I know it's coming late but for those people who want to implement it purely using the JavaScript , here's how you can do it:

  1. Get the reference to the current tr which is clicked.
  2. Make a new tr DOM element.
  3. Add it to the referred tr parent node.


                        <button id="0" onclick="addRow()">Expand</button>

                        <button id="1" onclick="addRow()">Expand</button>
                        <button id="2" onclick="addRow()">Expand</button>

In JavaScript:

function addRow() {
        var evt =;
        var btn_clicked = document.getElementById(evt);
        var tr_referred = btn_clicked.parentNode.parentNode;
        var td = document.createElement('td');
        td.innerHTML = 'abc';
        var tr = document.createElement('tr');
        tr_referred.parentNode.insertBefore(tr, tr_referred.nextSibling);
        return tr;

This will add the new table row exactly below the row on which the button is clicked.

Comparing floating point number to zero


Equality is equality.

The function you wrote will not test two doubles for equality, as its name promises. It will only test if two doubles are "close enough" to each other.

If you really want to test two doubles for equality, use this one:

inline bool isEqual(double x, double y)
   return x == y;

Coding standards usually recommend against comparing two doubles for exact equality. But that is a different subject. If you actually want to compare two doubles for exact equality, x == y is the code you want.

10.000000000000001 is not equal to 10.0, no matter what they tell you.

An example of using exact equality is when a particular value of a double is used as a synonym of some special state, such as "pending calulation" or "no data available". This is possible only if the actual numeric values after that pending calculation are only a subset of the possible values of a double. The most typical particular case is when that value is nonnegative, and you use -1.0 as an (exact) representation of a "pending calculation" or "no data available". You could represent that with a constant:

const double NO_DATA = -1.0;

double myData = getSomeDataWhichIsAlwaysNonNegative(someParameters);

if (myData != NO_DATA)

Array to Hash Ruby

a = ["item 1", "item 2", "item 3", "item 4"]
h = Hash[*a] # => { "item 1" => "item 2", "item 3" => "item 4" }

That's it. The * is called the splat operator.

One caveat per @Mike Lewis (in the comments): "Be very careful with this. Ruby expands splats on the stack. If you do this with a large dataset, expect to blow out your stack."

So, for most general use cases this method is great, but use a different method if you want to do the conversion on lots of data. For example, @Lukasz Niemier (also in the comments) offers this method for large data sets:

h = Hash[a.each_slice(2).to_a]

Normalize data in pandas

Slightly modified from: Python Pandas Dataframe: Normalize data between 0.01 and 0.99? but from some of the comments thought it was relevant (sorry if considered a repost though...)

I wanted customized normalization in that regular percentile of datum or z-score was not adequate. Sometimes I knew what the feasible max and min of the population were, and therefore wanted to define it other than my sample, or a different midpoint, or whatever! This can often be useful for rescaling and normalizing data for neural nets where you may want all inputs between 0 and 1, but some of your data may need to be scaled in a more customized way... because percentiles and stdevs assumes your sample covers the population, but sometimes we know this isn't true. It was also very useful for me when visualizing data in heatmaps. So i built a custom function (used extra steps in the code here to make it as readable as possible):

def NormData(s,low='min',center='mid',hi='max',insideout=False,shrinkfactor=0.):    
    if low=='min':
    elif low=='abs':
    if hi=='max':
    elif hi=='abs':

    if center=='mid':
    elif center=='avg':
    elif center=='median':

    s2=[x-center for x in s]


    for x in s2:
        if x<low:
        elif x>hi:
            if x>=center:

    if insideout==True:
        ir=[(1.-abs(z-0.5)*2.) for z in r]

    rr =[x-(x-0.5)*shrinkfactor for x in r]    
    return rr

This will take in a pandas series, or even just a list and normalize it to your specified low, center, and high points. also there is a shrink factor! to allow you to scale down the data away from endpoints 0 and 1 (I had to do this when combining colormaps in matplotlib:Single pcolormesh with more than one colormap using Matplotlib) So you can likely see how the code works, but basically say you have values [-5,1,10] in a sample, but want to normalize based on a range of -7 to 7 (so anything above 7, our "10" is treated as a 7 effectively) with a midpoint of 2, but shrink it to fit a 256 RGB colormap:

[0.1279296875, 0.5826822916666667, 0.99609375]

It can also turn your data inside out... this may seem odd, but I found it useful for heatmapping. Say you want a darker color for values closer to 0 rather than hi/low. You could heatmap based on normalized data where insideout=True:

[0.251953125, 0.8307291666666666, 0.00390625]

So now "2" which is closest to the center, defined as "1" is the highest value.

Anyways, I thought my application was relevant if you're looking to rescale data in other ways that could have useful applications to you.

How to capitalize the first letter in a String in Ruby

Unfortunately, it is impossible for a machine to upcase/downcase/capitalize properly. It needs way too much contextual information for a computer to understand.

That's why Ruby's String class only supports capitalization for ASCII characters, because there it's at least somewhat well-defined.

What do I mean by "contextual information"?

For example, to capitalize i properly, you need to know which language the text is in. English, for example, has only two is: capital I without a dot and small i with a dot. But Turkish has four is: capital I without a dot, capital I with a dot, small i without a dot, small i with a dot. So, in English 'i'.upcase # => 'I' and in Turkish 'i'.upcase # => 'I'. In other words: since 'i'.upcase can return two different results, depending on the language, it is obviously impossible to correctly capitalize a word without knowing its language.

But Ruby doesn't know the language, it only knows the encoding. Therefore it is impossible to properly capitalize a string with Ruby's built-in functionality.

It gets worse: even with knowing the language, it is sometimes impossible to do capitalization properly. For example, in German, 'Maße'.upcase # => 'MASSE' (Maße is the plural of Maß meaning measurement). However, 'Masse'.upcase # => 'MASSE' (meaning mass). So, what is 'MASSE'.capitalize? In other words: correctly capitalizing requires a full-blown Artificial Intelligence.

So, instead of sometimes giving the wrong answer, Ruby chooses to sometimes give no answer at all, which is why non-ASCII characters simply get ignored in downcase/upcase/capitalize operations. (Which of course also reads to wrong results, but at least it's easy to check.)

Python socket connection timeout

You just need to use the socket settimeout() method before attempting the connect(), please note that after connecting you must settimeout(None) to set the socket into blocking mode, such is required for the makefile . Here is the code I am using:

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
fileobj = sock.makefile('rb', 0)

HTML&CSS + Twitter Bootstrap: full page layout or height 100% - Npx

I've found a post here on Stackoverflow and implemented your design:

Here's the original post:

Is that what you're looking for?


<div class="container-fluid wrapper">

  <div class="row-fluid columns content"> 

    <div class="span2 article-tree">
      navigation column

    <div class="span10 content-area">
      content column 

  <div class="footer">
     footer content


html, body {
    height: 100%;
.container-fluid {
    margin: 0 auto;
    height: 100%;
    padding: 20px 0;

    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box;
    box-sizing: border-box;

.columns {
    background-color: #C9E6FF;
    height: 100%;   

.content-area, .article-tree{
    background: #bada55;
    height: 100%;

.footer {
    background: red;
    height: 20px;

Including jars in classpath on commandline (javac or apt)

Use the -cp or -classpath switch.

$ java -help  
Usage: java [-options] class [args...]  
           (to execute a class)  
   or  java [-options] -jar jarfile [args...]  
           (to execute a jar file)  

where options include:  
    -cp <class search path of directories and zip/jar files>  
    -classpath <class search path of directories and zip/jar files>  
                  A ; separated list of directories, JAR archives,  
                  and ZIP archives to search for class files.  

(Note that the separator used to separate entries on the classpath differs between OSes, on my Windows machine it is ;, in *nix it is usually :.)

A Generic error occurred in GDI+ in Bitmap.Save method

I use this solution

int G = 0;

private void toolStripMenuItem17_Click(object sender, EventArgs e)
  Directory.CreateDirectory("picture");// ??? ??????? ????? ???? ?? ???? ???? ????????
  G = G + 1;
  memoryImage1.Save("picture\\picture" + G.ToString() + ".jpg");
  pictureBox1.Image = Image.FromFile("picture\\picture" + G.ToString() + ".jpg");

How to make links in a TextView clickable?

Only what do you need to add this in text view in xml


How to get the instance id from within an ec2 instance?

You can try this:

aws_instance=$(wget -q -O-
aws_region=$(wget -q -O-
aws_zone=`ec2-describe-instances $aws_instance --region $aws_region`
aws_zone=`expr match "$aws_zone" ".*\($aws_region[a-z]\)"`

How do I Geocode 20 addresses without receiving an OVER_QUERY_LIMIT response?

No, there is not really any other way : if you have many locations and want to display them on a map, the best solution is to :

  • fetch the latitude+longitude, using the geocoder, when a location is created
  • store those in your database, alongside the address
  • and use those stored latitude+longitude when you want to display the map.

This is, of course, considering that you have a lot less creation/modification of locations than you have consultations of locations.

Yes, it means you'll have to do a bit more work when saving the locations -- but it also means :

  • You'll be able to search by geographical coordinates
    • i.e. "I want a list of points that are near where I'm now"
  • Displaying the map will be a lot faster
    • Even with more than 20 locations on it
  • Oh, and, also (last but not least) : this will work ;-)
    • You will less likely hit the limit of X geocoder calls in N seconds.
    • And you will less likely hit the limit of Y geocoder calls per day.

Generating random strings with T-SQL

Below are the way to Generate 4 Or 8 Characters Long Random Alphanumeric String in SQL



Throwing exceptions in a PHP Try Catch block

To rethrow do

 throw $e;

not the message.

Python read next()

You don't need to read the next line, you are iterating through the lines. lines is a list (an array), and for line in lines is iterating over it. Every time you are finished with one you move onto the next line. If you want to skip to the next line just continue out of the current loop.

filne = "D:/testtube/testdkanimfilternode.txt"
f = open(filne, 'r+')

lines = f.readlines() # get all lines as a list (array)

# Iterate over each line, printing each line and then move to the next
for line in lines:
    print line


How to lazy load images in ListView in Android

UPDATE: if you're searching for a solution in 2020 backed by Kotlin Coroutines, try Coil.

Coil is an acronym for Coroutine Image Loader.


  1. Fast: Coil performs a number of optimizations including memory and disk caching, downsampling the image in memory, re-using bitmaps, automatically pausing/cancelling requests, and more.
  2. Lightweight: Coil adds ~2000 methods to your APK (for apps that already use OkHttp and Coroutines), which is comparable to Picasso and significantly less than Glide and Fresco.
  3. Easy to use: Coil's API leverages Kotlin's language features for simplicity and minimal boilerplate.
  4. Modern: Coil is Kotlin-first and uses modern libraries including Coroutines, OkHttp, Okio, and AndroidX Lifecycles.

Gradle Setup:

Coil is available on mavenCentral().


Quick Start

To load an image into an ImageView, use the load extension function:

// URL

// Resource

// File

or on Background threads

// Coil (suspends the current coroutine; non-blocking and thread safe)
val request = ImageRequest.Builder(context)
    .size(width, height)
val drawable = context.imageLoader.execute(request).drawable

You can also migrate from Picasso/Glide

Full documentation here

Run function in script from command line (Node JS)

If you turn db.js into a module you can require it from db_init.js and just: node db_init.js.


module.exports = {
  method1: function () { ... },
  method2: function () { ... }


var db = require('./db');


How to check if android checkbox is checked within its onClick method (declared in XML)?

This will do the trick:

  public void itemClicked(View v) {
    if (((CheckBox) v).isChecked()) {
           "Checked", Toast.LENGTH_LONG).show();

How to prevent gcc optimizing some statements in C?

Instead of using the new pragmas, you can also use __attribute__((optimize("O0"))) for your needs. This has the advantage of just applying to a single function and not all functions defined in the same file.

Usage example:

void __attribute__((optimize("O0"))) foo(unsigned char data) {
    // unmodifiable compiler code

Under which circumstances textAlign property works in Flutter?

For maximum flexibility, I usually prefer working with SizedBox like this:

                                children: <Widget>[
                                      width: 235,
                                      child: Text('Hey, ')),
                                      width: 110,
                                      child: Text('how are'),
                                      width: 10,
                                      child: Text('you?'))

I've experienced problems with text alignment when using alignment in the past, whereas sizedbox always does the work.

How to restart ADB manually from Android Studio

Open task manager and kill adb.exe, now adb will start normally

How to type ":" ("colon") in regexp?

Be careful, - has a special meaning with regexp. In a [], you can put it without problem if it is placed at the end. In your case, ,-: is taken as from , to :.

Place a button right aligned

In my case the

<p align="right"/>

worked fine

Change status bar color with AppCompat ActionBarActivity

There are various ways of changing the status bar color.

1) Using the styles.xml. You can use the android:statusBarColor attribute to do this the easy but static way.

Note: You can also use this attribute with the Material theme.

<?xml version="1.0" encoding="utf-8"?>
    <style name="AppTheme" parent="AppTheme.Base">
        <item name="android:statusBarColor">@android:color/transparent</item>

2) You can get it done dynamically using the setStatusBarColor(int) method in the Window class. But remember that this method is only available for API 21 or higher. So be sure to check that, or your app will surely crash in lower devices.

Here is a working example of this method.

if (Build.VERSION.SDK_INT >= 21) {
            Window window = getWindow();

where primaryDark is the 700 tint of the primary color I am using in my app. You can define this color in the colors.xml file.

Do give it a try and let me know if you have any questions. Hope it helps.

Disabling submit button until all fields have values

$('#user_input, #pass_input, #v_pass_input, #email').bind('keyup', function() {
    if(allFilled()) $('#register').removeAttr('disabled');

function allFilled() {
    var filled = true;
    $('body input').each(function() {
        if($(this).val() == '') filled = false;
    return filled;

JSFiddle with your code, works :)

What is the difference between instanceof and Class.isAssignableFrom(...)?

Talking in terms of performance "2" (with JMH):

class A{}
class B extends A{}

public class InstanceOfTest {

public static final Object a = new A();
public static final Object b = new B();

public boolean testInstanceOf()
    return b instanceof A;

public boolean testIsInstance()
    return A.class.isInstance(b);

public boolean testIsAssignableFrom()
    return A.class.isAssignableFrom(b.getClass());

public static void main(String[] args) throws RunnerException {
    Options opt = new OptionsBuilder()

    new Runner(opt).run();

It gives:

Benchmark                            Mode  Cnt  Score   Error  Units
InstanceOfTest.testInstanceOf        avgt    5  1,972 ? 0,002  ns/op
InstanceOfTest.testIsAssignableFrom  avgt    5  1,991 ? 0,004  ns/op
InstanceOfTest.testIsInstance        avgt    5  1,972 ? 0,003  ns/op

So that we can conclude: instanceof as fast as isInstance() and isAssignableFrom() not far away (+0.9% executon time). So no real difference whatever you choose

How to detect if numpy is installed

The traditional method for checking for packages in Python is "it's better to beg forgiveness than ask permission", or rather, "it's better to catch an exception than test a condition."

    import numpy
    HAS_NUMPY = True
except ImportError:
    HAS_NUMPY = False

Selecting multiple columns/fields in MySQL subquery

Yes, you can do this. The knack you need is the concept that there are two ways of getting tables out of the table server. One way is ..


The other way is

FROM (SELECT col as name1, col2 as name2 FROM ...) B

Notice that the select clause and the parentheses around it are a table, a virtual table.

So, using your second code example (I am guessing at the columns you are hoping to retrieve here):

SELECT a.attr,, b.trans, b.lang
FROM attribute a
 SELECT AS id, at.translation AS trans, at.language AS lang, a.attribute
 FROM attributeTranslation at
) b ON ( = b.attribute AND b.lang = 1)

Notice that your real table attribute is the first table in this join, and that this virtual table I've called b is the second table.

This technique comes in especially handy when the virtual table is a summary table of some kind. e.g.

SELECT a.attr,, b.trans, b.lang, c.langcount
FROM attribute a
 SELECT AS id, at.translation AS trans, at.language AS lang, at.attribute
 FROM attributeTranslation at
) b ON ( = b.attribute AND b.lang = 1)
 SELECT count(*) AS langcount,  at.attribute
 FROM attributeTranslation at
 GROUP BY at.attribute
) c ON ( = c.attribute)

See how that goes? You've generated a virtual table c containing two columns, joined it to the other two, used one of the columns for the ON clause, and returned the other as a column in your result set.

Printing Java Collections Nicely (toString Doesn't Return Pretty Output)

System.out.println(Collection c) already print any type of collection in readable format. Only if collection contains user defined objects , then you need to implement toString() in user defined class to display content.

Convert from List into IEnumerable format

As far as I know List<T> implements IEnumerable<T>. It means that you do not have to convert or cast anything.

What's a quick way to comment/uncomment lines in Vim?

Here's a basic one-liner based on the C-v followed by I method outlined above.

This command (:Comment) adds a chosen string to the beginning of any selected lines.

command! -range -nargs=1 Comment :execute "'<,'>normal! <C-v>0I" . <f-args> . "<Esc><Esc>"

Add this line to your .vimrc to create a command that accepts a single argument and places the argument at the beginning of every line in the current selection.

E.g. if the following text is selected:


and you run this: :Comment //, the result will be:


Difference between 2 dates in seconds

$timeFirst  = strtotime('2011-05-12 18:20:20');
$timeSecond = strtotime('2011-05-13 18:20:20');
$differenceInSeconds = $timeSecond - $timeFirst;

You will then be able to use the seconds to find minutes, hours, days, etc.

How do I get started with Node.js

You can follow these tutorials to get started


Developer Sites







JavaScript resources

Node.js Modules


How to get Latitude and Longitude of the mobile device in android?

You can use FusedLocationProvider

For using Fused Location Provider in your project you will have to add the google play services location dependency in our app level build.gradle file

dependencies {
   implementation fileTree(dir: 'libs', include: ['*.jar'])
   implementation ''

Permissions in Manifest

Apps that use location services must request location permissions. Android offers two location permissions: ACCESS_COARSE_LOCATION and ACCESS_FINE_LOCATION.

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

As you may know that from Android 6.0 (Marshmallow) you must request permissions for important access in the runtime. Cause it’s a security issue where while installing an application, user may not clearly understand about an important permission of their device.

    arrayOf(Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION),

Then you can use the FusedLocationProvider Client to get the updated location in your desired place.

    mFusedLocationClient.lastLocation.addOnCompleteListener(this) { task ->
        var location: Location? = task.result
        if (location == null) {
        } else {
            findViewById<TextView>( = location.latitude.toString()
            findViewById<TextView>( = location.longitude.toString()

You can also check certain configuration like if the device has location settings on or not. You can also check the article on Detect Current Latitude & Longitude using Kotlin in Android for more functionality. If there is no cache location then it will catch the current location using:

private fun requestNewLocationData() {
    var mLocationRequest = LocationRequest()
    mLocationRequest.priority = LocationRequest.PRIORITY_HIGH_ACCURACY
    mLocationRequest.interval = 0
    mLocationRequest.fastestInterval = 0
    mLocationRequest.numUpdates = 1

    mFusedLocationClient = LocationServices.getFusedLocationProviderClient(this)
            mLocationRequest, mLocationCallback,

Cannot install signed apk to device manually, got error "App not installed"

if Your Android Studio Version Greater than 3.0

Looks like we can not directly use the apk after running on the device from the build -->output->apk folder.

After upgrading to android studio 3.0 you need to go to Build -> Build Apk(s) then copy the apk from build -> output -> apk -> debug

enter image description here

Cannot implicitly convert type 'string' to 'System.Threading.Tasks.Task<string>'

Use FromResult Method

public async Task<string> GetString()
   return await Task.FromResult("Hello");

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

Complete guide :

As per Android official Blogs :

We can say that:

  • If the manifest package name has changed, the new application will be installed alongside the old application, so they both co-exist on the user’s device at the same time.

  • If the signing certificate changes, trying to install the new application on to the device will fail until the old version is uninstalled.

As per Google App Update check list :

Update your apps

Prepare your APK

When you're ready to make changes to your APK, make sure to update your app’s version code as well so that existing users will receive your update.

Use the following checklist to make sure your new APK is ready to update your existing users:

  • The package name of the updated APK needs to be the same as the current version.
  • The version code needs to be greater than that current version. Learn more about versioning your applications.
  • The updated APK needs to be signed with the same signature as the current version.

To verify that your APK is using the same certification as the previous version, you can run the following command on both APKs and compare the results:

$ jarsigner -verify -verbose -certs my_application.apk

If the results are identical, you’re using the same key and are ready to continue. If the results are different, you will need to re-sign the APK with the correct key.

Learn more about signing your applications

Upload your APK Once your APK is ready, you can create a new release.

What is the easiest way to remove the first character from a string?

Using regex:

str = 'string'
n = 1  #to remove first n characters

str[/.{#{str.size-n}}\z/] #=> "tring"

Sort a list of lists with a custom compare function

You need to slightly modify your compare function and use functools.cmp_to_key to pass it to sorted. Example code:

import functools

lst = [list(range(i, i+5)) for i in range(5, 1, -1)]

def fitness(item):
    return item[0]+item[1]+item[2]+item[3]+item[4]
def compare(item1, item2):
    return fitness(item1) - fitness(item2)

sorted(lst, key=functools.cmp_to_key(compare))


[[2, 3, 4, 5, 6], [3, 4, 5, 6, 7], [4, 5, 6, 7, 8], [5, 6, 7, 8, 9]]

Works :)

Where can I find the .apk file on my device, when I download any app and install?

You can use a file browser with an backup function, for example the ES File Explorer Long tap a item and select create backup

How can I make Bootstrap 4 columns all the same height?

Equal height columns is the default behaviour for Bootstrap 4 grids.

.col { background: red; }_x000D_
.col:nth-child(odd) { background: yellow; }
<link rel="stylesheet" href="" integrity="sha384-rwoIResjU2yc3z8GV/NPeZWAv56rSmLldC3R/AZzGRnGxQQKnKkoFVhFQhNUwEyJ" crossorigin="anonymous">_x000D_
<div class="container">_x000D_
  <div class="row">_x000D_
    <div class="col">_x000D_
      1 of 3_x000D_
    <div class="col">_x000D_
      1 of 3_x000D_
      Line 2_x000D_
      Line 3_x000D_
    <div class="col">_x000D_
      1 of 3_x000D_

Error when trying to inject a service into an angular component "EXCEPTION: Can't resolve all parameters for component", why?

I have encountered this error by mistyping the service's name, i.e. constructor (private myService: MyService).

For misspelled services, I was able to determine which service was the problem (I had several listed in the constructor) by inspecting the page in Chrome->Console. You will see as part of the message a "parameter" array list by displaying object Object, object Object, ? (or something like that). Notice where the "?" is and that is the position of the service that is causing the problem.

Right click to select a row in a Datagridview and show a menu to delete it

For completness of this question, better to use a Grid event rather than mouse.

First Set your datagrid properties:

SelectionMode to FullRowSelect and RowTemplate / ContextMenuStrip to a context menu.

Create the CellMouseDown event:-

private void myDatagridView_CellMouseDown(object sender, DataGridViewCellMouseEventArgs e)
    if (e.Button == MouseButtons.Right)
        int rowSelected = e.RowIndex;
        if (e.RowIndex != -1)
            this.myDatagridView.Rows[rowSelected].Selected = true;
        // you now have the selected row with the context menu showing for the user to delete etc.

Difference between abstraction and encapsulation?

Abstraction--- Hiding Implementation--at Design---Using Interface/Abstract calsses

Encapsulation--Hiding Data --At Development---Using access modifiers(public/private)

What replaces cellpadding, cellspacing, valign, and align in HTML5 tables?

Alternatively, can use for particular table

 <table style="width:1000px; height:100px;">
        <td align="center" valign="top">Text</td> //Remove it
        <td class="tableFormatter">Text></td>

Add this css in external file


Check play state of AVPlayer

Swift extension based on the answer by maz

extension AVPlayer {

    var isPlaying: Bool {
        return ((rate != 0) && (error == nil))

Case vs If Else If: Which is more efficient?

The debugger is making it simpler, because you don't want to step through the actual code that the compiler creates.

If the switch contains more than five items, it's implemented using a lookup table or hash table, otherwise it's implemeneted using an if..else.

See the closely related question is “else if” faster than “switch() case” ?.

Other languages than C# will of course implement it more or less differently, but a switch is generally more efficient.

Laravel Redirect Back with() Message

I stopped writing this myself for laravel in favor of the Laracasts package that handles it all for you. It is really easy to use and keeps your code clean. There is even a laracast that covers how to use it. All you have to do:

Pull in the package through Composer.

"require": {
  "laracasts/flash": "~1.0"

Include the service provider within app/config/app.php.

'providers' => [

Add a facade alias to this same file at the bottom:

'aliases' => [
  'Flash' => 'Laracasts\Flash\Flash'

Pull the HTML into the view:


There is a close button on the right of the message. This relies on jQuery so make sure that is added before your bootstrap.

optional changes:

If you aren't using bootstrap or want to skip the include of the flash message and write the code yourself:

@if (Session::has('flash_notification.message'))
  <div class="{{ Session::get('flash_notification.level') }}">
    {{ Session::get('flash_notification.message') }}

If you would like to view the HTML pulled in by @include('flash::message'), you can find it in vendor/laracasts/flash/src/views/message.blade.php.

If you need to modify the partials do:

php artisan view:publish laracasts/flash

The two package views will now be located in the `app/views/packages/laracasts/flash/' directory.

View/edit ID3 data for MP3 files

ID3.NET implemented ID3v1.x and ID3v2.3 and supports read/write operations on the ID3 section in MP3 files. There's also a NuGet package available.

How do I convert from int to Long in Java?

 1,new Long(intValue);

post checkbox value

in normal time, checkboxes return an on/off value.

you can verify it with this code:

<form action method="POST">
      <input type="checkbox" name="hello"/>

if(isset($_POST['hello'])) echo('<p>'.$_POST['hello'].'</p>');

this will return




Changing background color of ListView items on Android

In the list view you can add android:listselector=color name that you want.

this work fine in my app.

localhost refused to connect Error in visual studio

I was having this issue and solved it by closing all open instances of Visual Studio.

How to set the max size of upload file

Also in Spring boot 1.4, you can add following lines to your to set the file size limit:


for spring boot 2.x and above its


Worked for me. Source:


Somebody asked the differences between the two properties.

Below are the formal definitions:

MaxFileSize: The maximum size allowed for uploaded files, in bytes. If the size of any uploaded file is greater than this size, the web container will throw an exception (IllegalStateException). The default size is unlimited.

MaxRequestSize: The maximum size allowed for a multipart/form-data request, in bytes. The web container will throw an exception if the overall size of all uploaded files exceeds this threshold. The default size is unlimited.

To explain each:

MaxFileSize: The limit for a single file to upload. This is applied for the single file limit only.

MaxRequestSize: The limit for the total size of all files in a single upload request. This checks the total limit. Let's say you have two files a.txt and b.txt for a single upload request. a.txt is 5kb and b.txt is 7kb so the MaxRequestSize should be above 12kb.

Impact of Xcode build options "Enable bitcode" Yes/No

  • What does the ENABLE_BITCODE actually do, will it be a non-optional requirement in the future?

I'm not sure at what level you are looking for an answer at, so let's take a little trip. Some of this you may already know.

When you build your project, Xcode invokes clang for Objective-C targets and swift/swiftc for Swift targets. Both of these compilers compile the app to an intermediate representation (IR), one of these IRs is bitcode. From this IR, a program called LLVM takes over and creates the binaries needed for x86 32 and 64 bit modes (for the simulator) and arm6/arm7/arm7s/arm64 (for the device). Normally, all of these different binaries are lumped together in a single file called a fat binary.

The ENABLE_BITCODE option cuts out this final step. It creates a version of the app with an IR bitcode binary. This has a number of nice features, but one giant drawback: it can't run anywhere. In order to get an app with a bitcode binary to run, the bitcode needs to be recompiled (maybe assembled or transcoded… I'm not sure of the correct verb) into an x86 or ARM binary.

When a bitcode app is submitted to the App Store, Apple will do this final step and create the finished binaries.

Right now, bitcode apps are optional, but history has shown Apple turns optional things into requirements (like 64 bit support). This usually takes a few years, so third party developers (like Parse) have time to update.

  • can I use the above method without any negative impact and without compromising a future appstore submission?

Yes, you can turn off ENABLE_BITCODE and everything will work just like before. Until Apple makes bitcode apps a requirement for the App Store, you will be fine.

  • Are there any performance impacts if I enable / disable it?

There will never be negative performance impacts for enabling it, but internal distribution of an app for testing may get more complicated.

As for positive impacts… well that's complicated.

For distribution in the App Store, Apple will create separate versions of your app for each machine architecture (arm6/arm7/arm7s/arm64) instead of one app with a fat binary. This means the app installed on iOS devices will be smaller.

In addition, when bitcode is recompiled (maybe assembled or transcoded… again, I'm not sure of the correct verb), it is optimized. LLVM is always working on creating new a better optimizations. In theory, the App Store could recreate the separate version of the app in the App Store with each new release of LLVM, so your app could be re-optimized with the latest LLVM technology.

get Context in non-Activity class

If your class is non-activity class, and creating an instance of it from the activiy, you can pass an instance of context via constructor of the later as follows:

class YourNonActivityClass{

// variable to hold context
private Context context;

//save the context recievied via constructor in a local variable

public YourNonActivityClass(Context context){


You can create instance of this class from the activity as follows:

new YourNonActivityClass(this);

Callback functions in C++

See the above definition where it states that a callback function is passed off to some other function and at some point it is called.

In C++ it is desirable to have callback functions call a classes method. When you do this you have access to the member data. If you use the C way of defining a callback you will have to point it to a static member function. This is not very desirable.

Here is how you can use callbacks in C++. Assume 4 files. A pair of .CPP/.H files for each class. Class C1 is the class with a method we want to callback. C2 calls back to C1's method. In this example the callback function takes 1 parameter which I added for the readers sake. The example doesn't show any objects being instantiated and used. One use case for this implementation is when you have one class that reads and stores data into temporary space and another that post processes the data. With a callback function, for every row of data read the callback can then process it. This technique cuts outs the overhead of the temporary space required. It is particularly useful for SQL queries that return a large amount of data which then has to be post-processed.

// C1 H file

class C1
    C1() {};
    ~C1() {};
    void CALLBACK F1(int i);

// C1 CPP file

void CALLBACK C1::F1(int i)
// Do stuff with C1, its methods and data, and even do stuff with the passed in parameter

// C2 H File

class C1; // Forward declaration

class C2
    typedef void (CALLBACK C1::* pfnCallBack)(int i);
    C2() {};
    ~C2() {};

    void Fn(C1 * pThat,pfnCallBack pFn);

// C2 CPP File

void C2::Fn(C1 * pThat,pfnCallBack pFn)
    // Call a non-static method in C1
    int i = 1;

HTTP Error 404 when running Tomcat from Eclipse

Another way to fix this would be to go to the properties of the server on eclipse (right click on server -> properties) In general tab you would see location as workspace.metadata. Click on switch location.

how to add a day to a date using jquery datepicker

This answer really helped me get started (noob) - but I encountered some weird behavior when I set a start date of 12/31/2014 and added +1 to default the end date. Instead of giving me an end date of 01/01/2015 I was getting 02/01/2015 (!!!). This version parses the components of the start date to avoid these end of year oddities.

 $( "#date_start" ).datepicker({

   minDate: 0,
   dateFormat: "mm/dd/yy",

   onSelect: function(selected) {
         $("#date_end").datepicker("option","minDate", selected); //  mindate on the End datepicker cannot be less than start date already selected.
         var date = $(this).datepicker('getDate');
         var tempStartDate = new Date(date);
         var default_end = new Date(tempStartDate.getFullYear(), tempStartDate.getMonth(), tempStartDate.getDate()+1); //this parses date to overcome new year date weirdness
         $('#date_end').datepicker('setDate', default_end); // Set as default                           


 $( "#date_end" ).datepicker({

   minDate: 0,
   dateFormat: "mm/dd/yy",

   onSelect: function(selected) {
     $("#date_start").datepicker("option","maxDate", selected); //  maxdate on the Start datepicker cannot be more than end date selected.



How do you move a file?

If I'm not wrong starting from version 1.5 SVN can track moved files\folders. In TortoiseSVN use can move file via drag&drop.

How to launch multiple Internet Explorer windows/tabs from batch file?

Try this in your batch file:

@echo off
start /d "C:\Program Files\Internet Explorer" IEXPLORE.EXE
start /d "C:\Program Files\Internet Explorer" IEXPLORE.EXE

Transposing a 2D-array in JavaScript

Many good answers here! I consolidated them into one answer and updated some of the code for a more modern syntax:

One-liners inspired by Fawad Ghafoor and Óscar Gómez Alcañiz

function transpose(matrix) {
  return matrix[0].map((col, i) => => row[i]));

function transpose(matrix) {
  return matrix[0].map((col, c) =>, r) => matrix[r][c]));

Functional approach style with reduce by Andrew Tatomyr

function transpose(matrix) {
  return matrix.reduce((prev, next) =>, i) =>
    (prev[i] || []).concat(next[i])
  ), []);

Lodash/Underscore by marcel

function tranpose(matrix) {

// Without spread operator.
function transpose(matrix) {
  return, [[1,2,3], [1,2,3], [1,2,3]])

Vanilla approach

function transpose(matrix) {
  const rows = matrix.length, cols = matrix[0].length;
  const grid = [];
  for (let j = 0; j < cols; j++) {
    grid[j] = Array(rows);
  for (let i = 0; i < rows; i++) {
    for (let j = 0; j < cols; j++) {
      grid[j][i] = matrix[i][j];
  return grid;

Vanilla in-place ES6 approach inspired by Emanuel Saringan

function transpose(matrix) {
  for (var i = 0; i < matrix.length; i++) {
    for (var j = 0; j < i; j++) {
      const temp = matrix[i][j];
      matrix[i][j] = matrix[j][i];
      matrix[j][i] = temp;

// Using destructing
function transpose(matrix) {
  for (var i = 0; i < matrix.length; i++) {
    for (var j = 0; j < i; j++) {
      [matrix[i][j], matrix[j][i]] = [matrix[j][i], matrix[i][j]];

horizontal line and right way to code it in html, css

In HTML5, the <hr> tag defines a thematic break. In HTML 4.01, the <hr> tag represents a horizontal rule.

So after definition, I would prefer <hr>

Class JavaLaunchHelper is implemented in both. One of the two will be used. Which one is undefined

  1. Install Java 7u21 from here:

  2. set these variables:

    export JAVA_HOME="/Library/Java/JavaVirtualMachines/jdk1.7.0_21.jdk/Contents/Home"
    export PATH=$JAVA_HOME/bin:$PATH
  3. Run your app and fun :)

(Minor update: put variable value in quote)

Hexadecimal string to byte array in C

As far as I know, there's no standard function to do so, but it's simple to achieve in the following manner:

#include <stdio.h>

int main(int argc, char **argv) {
    const char hexstring[] = "DEadbeef10203040b00b1e50", *pos = hexstring;
    unsigned char val[12];

     /* WARNING: no sanitization or error-checking whatsoever */
    for (size_t count = 0; count < sizeof val/sizeof *val; count++) {
        sscanf(pos, "%2hhx", &val[count]);
        pos += 2;

    for(size_t count = 0; count < sizeof val/sizeof *val; count++)
        printf("%02x", val[count]);

    return 0;


As Al pointed out, in case of an odd number of hex digits in the string, you have to make sure you prefix it with a starting 0. For example, the string "f00f5" will be evaluated as {0xf0, 0x0f, 0x05} erroneously by the above example, instead of the proper {0x0f, 0x00, 0xf5}.

Amended the example a little bit to address the comment from @MassimoCallegari

Can't bind to 'formGroup' since it isn't a known property of 'form'

Once I added my module to the AppModule everything started working fine.

C++ equivalent of java's instanceof

Depending on what you want to do you could do this:

template<typename Base, typename T>
inline bool instanceof(const T*) {
    return std::is_base_of<Base, T>::value;


if (instanceof<BaseClass>(ptr)) { ... }

However, this purely operates on the types as known by the compiler.


This code should work for polymorphic pointers:

template<typename Base, typename T>
inline bool instanceof(const T *ptr) {
    return dynamic_cast<const Base*>(ptr) != nullptr;


dyld: Library not loaded: /usr/local/lib/libpng16.16.dylib with anything php related

I know this question has already an answer that gives a solution. But I want to give you my two cents to help people to understand the problem. Getting same issue I've created a specific question. I got same problem, but only with PHPStorm. And exactly when I try to run test from the editor.

dyld is the dynamic linker

I sow that dyld was looking for /usr/local/lib/libpng15.15.dylib but inside my /usr/local/lib/ there was not. In that folder, I got libpng16.16.dylib.

Thanks to a comment, I undestand that my /usr/bin/php was a pointer to php 5.5.8. Instead, ... /usr/local/bin/php was 5.5.14. PHPStorm worked with /usr/bin/php that is default configuration. When I run php via console, I run /urs/local/bin/php.

So, ... If you get some dyld error, maybe you have some wrong php configuration. That's the reason because

$ brew update && brew upgrade
$ brew reinstall php55

But I dont know why this do not solve the problem to me. Maybe because I have

Adding a custom header to HTTP request using angular.js

Chrome is preflighting the request to look for CORS headers. If the request is acceptable, it will then send the real request. If you're doing this cross-domain, you will simply have to deal with it or else find a way to make the request non-cross-domain. This is by design.

Unlike simple requests (discussed above), "preflighted" requests first send an HTTP request by the OPTIONS method to the resource on the other domain, in order to determine whether the actual request is safe to send. Cross-site requests are preflighted like this since they may have implications to user data. In particular, a request is preflighted if:

It uses methods other than GET, HEAD or POST. Also, if POST is used to send request data with a Content-Type other than application/x-www-form-urlencoded, multipart/form-data, or text/plain, e.g. if the POST request sends an XML payload to the server using application/xml or text/xml, then the request is preflighted. It sets custom headers in the request (e.g. the request uses a header such as X-PINGOTHER)

Ref: AJAX in Chrome sending OPTIONS instead of GET/POST/PUT/DELETE?

What does 'index 0 is out of bounds for axis 0 with size 0' mean?

In numpy, index and dimension numbering starts with 0. So axis 0 means the 1st dimension. Also in numpy a dimension can have length (size) 0. The simplest case is:

In [435]: x = np.zeros((0,), int)
In [436]: x
Out[436]: array([], dtype=int32)
In [437]: x[0]
IndexError: index 0 is out of bounds for axis 0 with size 0

I also get it if x = np.zeros((0,5), int), a 2d array with 0 rows, and 5 columns.

So someplace in your code you are creating an array with a size 0 first axis.

When asking about errors, it is expected that you tell us where the error occurs.

Also when debugging problems like this, the first thing you should do is print the shape (and maybe the dtype) of the suspected variables.

Applied to pandas

Resolving the error:

  1. Use a try-except block
  2. Verify the size of the array is not 0
    • if x.size != 0:

ActiveXObject in Firefox or Chrome (not IE!)

ActiveX resolved in Chrome!
Hello all this is not the solution but the successful workaround and I have implemented as well.
This required some implementation on client machine as well that why is most suitable for intranet environment and not recommended for public sites. Even though one can implement it for public sites as well the only problem is end user has to download/implement solution.
Lets understand the key problem
Chrome cannot communicate with ActiceX
Solution: Since Chorme cannot communicate with ActiveX but still it can communicate with the API hosted on the client machine. So develop API using .Net MVC or any other technology so that through Ajax call it can communicate with the API and API communicate with the ActiveX object situated on the client machine. Since API also resides in Client machine that why there is no problem in communication. This API works as mediator between Chrome browser and ActiveX.
During API implementation you might encounter CORS issues, Use JSONP to deal with it.
Pictorial view of the solution Pictorial view of the solution

Other solution : Use URI Scheme like MailTo: or MS-Word to deal with outlook and word application. If your requirement is different then you can implement your customized URI Scheme.

how to set image from url for imageView


URL newurl = new URL(photo_url_str); 
mIcon_val = BitmapFactory.decodeStream(newurl.openConnection() .getInputStream()); 

More from

1) how-to-load-an-imageview-by-url-in-android.

2) android-make-an-image-at-a-url-equal-to-imageviews-image

Add/Delete table rows dynamically using JavaScript

If you put a delete button on each row, then:

  <td><input type="button" value="Delete row" onclick="deleteRow(this);">
  <td><input type="text">
  <td><input type="text">

And the deleteRow function can be:

function deleteRow(el) {
    // while there are parents, keep going until reach TR 
    while (el.parentNode && el.tagName.toLowerCase() != 'tr') {
        el = el.parentNode;

    // If el has a parentNode it must be a TR, so delete it
    // Don't delte if only 3 rows left in table
    if (el.parentNode && el.parentNode.rows.length > 3) {

If all your rows have the same content, it will be much faster to add a row by cloning an existing row:

function addRow(tableID) {
    var table = document.getElementById(tableID);

    if (!table) return;

    var newRow = table.rows[1].cloneNode(true);

    // Now get the inputs and modify their names 
    var inputs = newRow.getElementsByTagName('input');

    for (var i=0, iLen=inputs.length; i<iLen; i++) {
        // Update inputs[i]

    // Add the new row to the tBody (required for IE)
    var tBody = table.tBodies[0];
    tBody.insertBefore(newRow, tBody.lastChild);

reading a line from ifstream into a string variable

Use the std::getline() from <string>.

 istream & getline(istream & is,std::string& str)

So, for your case it would be:


Run task only if host does not belong to a group

Here's another way to do this:

- name: my command
  command: echo stuff
  when: "'groupname' not in group_names"

group_names is a magic variable as documented here: :

group_names is a list (array) of all the groups the current host is in.

Read a text file line by line in Qt

Use this code:

QFile inputFile(fileName);
if (
   QTextStream in(&inputFile);
   while (!in.atEnd())
      QString line = in.readLine();

Ubuntu apt-get unable to fetch packages

Just for the sake of any Googlers, if you're getting this error while building a Docker image, preface the failing RUN command with

apt-get update &&

This happens when Docker uses a cached image. Why the cached image wouldn't have the latest repo information the second time around is totally beyond me, but prefacing every single apt-get with an update does solve the problem.

Converting from longitude\latitude to Cartesian coordinates

If you care about getting coordinates based on an ellipsoid rather than a sphere, take a look at Geographic_coordinate_conversion - it gives the formulae. GEodetic Datum has the WGS84 constants you need for the conversion.

The formulae there also take into account the altitude relative to the reference ellipsoid surface (useful if you are getting altitude data from a GPS device).

What is the reason behind "non-static method cannot be referenced from a static context"?

So you are asking for a very core reason?

Well, since you are developing in Java, the compiler generates an object code that the Java Virtual Machine can interpret. The JVM anyway is a binary program that run in machine language (probably the JVM’s version specific for your operating system and hardware was previously compiled by another programming language like C in order to get a machine code that can run in your processor). At the end, any code is translated to machine code. So, create an object (an instance of a class) is equivalent to reserve a memory space (memory registers that will be processor registers when the CPU scheduler of the operating system put your program at the top of the queue in order to execute it) to have a data storage place that can be able to read and write data. If you don’t have an instance of a class (which happens on a static context), then you don’t have that memory space to read or write the data. In fact, like other people had said, the data don’t exist (because from the begin you never had written neither had reserved the memory space to store it).

Sorry for my english! I'm latin!

Is optimisation level -O3 dangerous in g++?

In my somewhat checkered experience, applying -O3 to an entire program almost always makes it slower (relative to -O2), because it turns on aggressive loop unrolling and inlining that make the program no longer fit in the instruction cache. For larger programs, this can also be true for -O2 relative to -Os!

The intended use pattern for -O3 is, after profiling your program, you manually apply it to a small handful of files containing critical inner loops that actually benefit from these aggressive space-for-speed tradeoffs. Newer versions of GCC have a profile-guided optimization mode that can (IIUC) selectively apply the -O3 optimizations to hot functions -- effectively automating this process.

DLL load failed error when importing cv2

If this helps someone, on official python 3.6 windows docker image, to make this thing work I had to copy following libraries from my desktop:





Inserting a tab character into text using C#

Try using the \t character in your strings

What's the yield keyword in JavaScript?

It's Really Simple, This is how it works

  • yield keyword simply helps to pause and resume a function in any time asynchronously.
  • Additionally it helps to return value from a generator function.

Take this simple generator function:

function* process() {
    console.log('Start process 1');
    console.log('Pause process2 until call next()');


    console.log('Resumed process2');
    console.log('Pause process3 until call next()');

    let parms = yield {age: 12};
    console.log("Passed by final process next(90): " + parms);

    console.log('Resumed process3');
    console.log('End of the process function');

let _process = process();

Until you call the it wont execute the first 2 lines of code, then the first yield will pause the function. To resume the function until next pause point (yield keyword) you need to call

You can think multiple yields are the breakpoints in a javascript debugger within a single function. Until you tell to navigate next breakpoint it wont execute the code block. (Note: without blocking the whole application)

But while yield performs this pause and resume behaviours it can return some results as well {value: any, done: boolean} according to the previous function we haven't emit any values. If we explore the previous output it will show the same { value: undefined, done: false } with value undefined.

Lets dig in to the yield keyword. Optionally you can add expression and set assign a default optional value. (Official doc syntax)

[rv] = yield [expression];

expression: Value to return from the generator function

yield any;
yield {age: 12};

rv: Returns the optional value that passed to the generator's next() method

Simply you can pass parameters to process() function with this mechanism, to execute different yield parts.

let val = yield 99;;
now the val will be 10 

Try It Now


  • Lazy evaluation
  • Infinite sequences
  • Asynchronous control flows


Read JSON data in a shell script


$ cat /tmp/so.json | underscore select '.Messages .Body' 

Javascript CLI tools

You can use Javascript CLI tools like


Select all name children of a addons:

underscore select ".addons > .name"

The underscore-cli provide others real world examples as well as the json:select() doc.

"find: paths must precede expression:" How do I specify a recursive search that also finds files in the current directory?

From find manual:


   Operator precedence surprises
   The command find . -name afile -o -name bfile -print will never print
   afile because this is actually equivalent to find . -name afile -o \(
   -name bfile -a -print \).  Remember that the precedence of -a is
   higher than that of -o and when there is no operator specified
   between tests, -a is assumed.

   “paths must precede expression” error message
   $ find . -name *.c -print
   find: paths must precede expression
   Usage: find [-H] [-L] [-P] [-Olevel] [-D ... [path...] [expression]

   This happens because *.c has been expanded by the shell resulting in
   find actually receiving a command line like this:
   find . -name frcode.c locate.c word_io.c -print
   That command is of course not going to work.  Instead of doing things
   this way, you should enclose the pattern in quotes or escape the
   $ find . -name '*.c' -print
   $ find . -name \*.c -print

typedef fixed length array

From R..'s answer:

However, this is probably a very bad idea, because the resulting type is an array type, but users of it won't see that it's an array type. If used as a function argument, it will be passed by reference, not by value, and the sizeof for it will then be wrong.

Users who don't see that it's an array will most likely write something like this (which fails):

#include <stdio.h>

typedef int twoInts[2];

void print(twoInts *twoIntsPtr);
void intermediate (twoInts twoIntsAppearsByValue);

int main () {
    twoInts a;
    a[0] = 0;
    a[1] = 1;
    return 0;
void intermediate(twoInts b) {

void print(twoInts *c){
    printf("%d\n%d\n", (*c)[0], (*c)[1]);

It will compile with the following warnings:

In function ‘intermediate’:
warning: passing argument 1 of ‘print’ from incompatible pointer type [enabled by default]
note: expected ‘int (*)[2]’ but argument is of type ‘int **’
    void print(twoInts *twoIntsPtr);

And produces the following output:


How/When does Execute Shell mark a build as failure in Jenkins?

In Jenkins ver. 1.635, it is impossible to show a native environment variable like this:


In this case, you have to set it in an other variable.


How to open a Bootstrap modal window using jQuery?

Try this. It's works for me well.

function clicked(item) {
<link href="" rel="stylesheet"/>
<script src=""></script>

<button onclick="clicked(this);" id="modalME">Click me</button>

<!-- Modal -->
  <div class="modal" id="modalME" aria-hidden="true">
    <div class="modal-dialog">
      <div class="modal-header">
        <h2>Modal in CSS</h2>
        <a href="#close" class="btn-close" aria-hidden="true">×</a> <!--CHANGED TO "#close"-->
      <div class="modal-body">
        <p>One modal example here.</p>
      <div class="modal-footer">
        <a href="#close" class="btn">Nice!</a>  <!--CHANGED TO "#close"-->
  <!-- /Modal -->

Converting stream of int's to char's in java

Maybe you are asking for:

Character.toChars(65) // returns ['A']

More info: Character.toChars(int codePoint)

Converts the specified character (Unicode code point) to its UTF-16 representation stored in a char array. If the specified code point is a BMP (Basic Multilingual Plane or Plane 0) value, the resulting char array has the same value as codePoint. If the specified code point is a supplementary code point, the resulting char array has the corresponding surrogate pair.

How can I display a tooltip message on hover using jQuery?

As recommended qTip and other projects are quite old I recommend using qTip2 as it is most up-to-date.

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

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

To use with ActiveSheet:

Call SelectAllCellsInSheet(ActiveSheet.Name)

Android Push Notifications: Icon not displaying in notification, white square shown instead

Declare this code in Android Manifest :

<meta-data android:name="" 

android:resource="@drawable/ic_stat_name" />

I hope this useful to you.

Spring MVC: How to return image in @ResponseBody?

This is how I do it with Spring Boot and Guava:

@RequestMapping(value = "/getimage", method = RequestMethod.GET, produces = MediaType.IMAGE_JPEG_VALUE)
public void getImage( HttpServletResponse response ) throws IOException
    ByteStreams.copy( getClass().getResourceAsStream( "/preview-image.jpg" ), response.getOutputStream() );

Command-line Git on Windows

In the latest version (v2.19 for Windows when I'm writing), if you choose the option "Use git in Windows command prompt" (or sth similar, please read the options carefully when you install git), you should be able to use git commands in windows command prompt or windows powershell without any additional setting. Just remember to restart the command line tool after you install git.

How to discard local changes and pull latest from GitHub repository

If you already committed the changes than you would have to revert changes.

If you didn't commit yet, just do a clean checkout git checkout .

Conditional formatting using AND() function

You can use a much simpler formula. I just created a new workbook to test it.

Column A = Date1 | Column B = Date2 | Column C = Date3

Highlight Column A and enter the conditional formatting formula:


Run Excel Macro from Outside Excel Using VBScript From Command Line

I think you are trying to do this? (TRIED AND TESTED)

This code will open the file Test.xls and run the macro TestMacro which will in turn write to the text file TestResult.txt

Option Explicit

Dim xlApp, xlBook

Set xlApp = CreateObject("Excel.Application")
'~~> Change Path here
Set xlBook = xlApp.Workbooks.Open("C:\Test.xls", 0, True)
xlApp.Run "TestMacro"

Set xlBook = Nothing
Set xlApp = Nothing

WScript.Echo "Finished."

Understanding the basics of Git and GitHub

  1. What is the difference between Git and GitHub?

    Linus Torvalds would kill you for this. Git is the name of the version manager program he wrote. GitHub is a website on which there are source code repositories manageable by Git. Thus, GitHub is completely unrelated to the original Git tool.

  2. Is git saving every repository locally (in the user's machine) and in GitHub?

    If you commit changes, it stores locally. Then, if you push the commits, it also sotres them remotely.

  3. Can you use Git without GitHub? If yes, what would be the benefit for using GitHub?

    You can, but I'm sure you don't want to manually set up a git server for yourself. Benefits of GitHub? Well, easy to use, lot of people know it so others may find your code and follow/fork it to make improvements as well.

  4. How does Git compare to a backup system such as Time Machine?

    Git is specifically designed and optimized for source code.

  5. Is this a manual process, in other words if you don't commit you wont have a new version of the changes made?


  6. If are not collaborating and you are already using a backup system why would you use Git?

    See #4.

ASP.NET MVC 3 - redirect to another action

Your method needs to return a ActionResult type:

public ActionResult Index()
    //All we want to do is redirect to the class selection page
    return RedirectToAction("SelectClasses", "Registration");

getting the last item in a javascript object

As for the ordering of object properties in Javascript, I will just link to this answer:

Elements order in a "for (… in …)" loop


All modern implementations of ECMAScript iterate through object properties in the order in which they were defined

So every other answer here is correct, there is no official guaranteed order to object properties. However in practice there is (barring any bugs which naturally can screw up even set-in-stone officially specified behavior).

Furthermore, the de-facto enumeration order of object properties is likely to be codified in future EMCAScript specs.

Still, at this time I would not write code around this, mostly because there are no built-in tools to help deal with object property order. You could write your own, but in the end you'd always be looping over each property in an object to determine its position.

As such the answer to your question is No, there is no way besides looping through an object.

Codeigniter $this->input->post() empty while $_POST is working correctly

To see all the post value try var_dump($this->input->post(ALL));

Javascript-Setting background image of a DIV via a function and function parameter

From what I know, the correct syntax is:

function ChangeBackgroungImageOfTab(tabName, imagePrefix)
    document.getElementById(tabName).style.backgroundImage = "url('buttons/" + imagePrefix + ".png')";

So basically, getElementById(tabName).backgroundImage and split the string like:

"cssInHere('and" + javascriptOutHere + "/cssAgain')";

Python: printing a file to stdout

Sure. Assuming you have a string with the file's name called fname, the following does the trick.

with open(fname, 'r') as fin:

‘ant’ is not recognized as an internal or external command

Need to see whether you got ant folder moved by mistake or unknowingly. It is set in environment variables.I resolved this once as mentioned below.

I removed ant folder by mistake and placed in another folder.I went to command prompt and typed "path". It has given me path as "F:\apache-ant-1.9.4\". So I moved the ant back to F drive and it resolved the issue.

How to create a custom exception type in Java?

Since you can just create and throw exceptions it could be as easy as

if ( word.contains(" ") )
     throw new RuntimeException ( "Word contains one or more spaces" ) ;

If you would like to be more formal, you can create an Exception class

class SpaceyWordException extends RuntimeException


Either way, if you use RuntimeException, your new Exception will be unchecked.

Auto-fit TextView for Android

I'll explain how works this attribute lower android versions step by step:

1- Import android support library 26.x.x on your project gradle file. If there is no support library on IDE, they will download automatically.

dependencies {
    compile ''
    compile ''
    compile '' }

allprojects {
    repositories {
        maven {
            url ""
    } }

2- Open your layout XML file and refactor like this tag your TextView. This scenario is: when incrased font size on system, fit text to avaliable width, not word wrap.

            android:text="Auto size text with compatible lower android versions."
            app:autoSizeTextType="uniform" />

Wait for Angular 2 to load/resolve model before rendering view/template

Try {{model?}} this should wait for model to not be undefined and then render.

Angular 2 refers to this ?. syntax as the Elvis operator. Reference to it in the documentation is hard to find so here is a copy of it in case they change/move it:

The Elvis Operator ( ?. ) and null property paths

The Angular “Elvis” operator ( ?. ) is a fluent and convenient way to guard against null and undefined values in property paths. Here it is, protecting against a view render failure if the currentHero is null.

The current hero's name is {{currentHero?.firstName}}

Let’s elaborate on the problem and this particular solution.

What happens when the following data bound title property is null?

The title is {{ title }}

The view still renders but the displayed value is blank; we see only "The title is" with nothing after it. That is reasonable behavior. At least the app doesn't crash.

Suppose the template expression involves a property path as in this next example where we’re displaying the firstName of a null hero.

The null hero's name is {{nullHero.firstName}}

JavaScript throws a null reference error and so does Angular:

TypeError: Cannot read property 'firstName' of null in [null]

Worse, the entire view disappears.

We could claim that this is reasonable behavior if we believed that the hero property must never be null. If it must never be null and yet it is null, we've made a programming error that should be caught and fixed. Throwing an exception is the right thing to do.

On the other hand, null values in the property path may be OK from time to time, especially when we know the data will arrive eventually.

While we wait for data, the view should render without complaint and the null property path should display as blank just as the title property does.

Unfortunately, our app crashes when the currentHero is null.

We could code around that problem with NgIf

<!--No hero, div not displayed, no error --> <div *ngIf="nullHero">The null hero's name is {{nullHero.firstName}}</div>

Or we could try to chain parts of the property path with &&, knowing that the expression bails out when it encounters the first null.

The null hero's name is {{nullHero && nullHero.firstName}}

These approaches have merit but they can be cumbersome, especially if the property path is long. Imagine guarding against a null somewhere in a long property path such as a.b.c.d.

The Angular “Elvis” operator ( ?. ) is a more fluent and convenient way to guard against nulls in property paths. The expression bails out when it hits the first null value. The display is blank but the app keeps rolling and there are no errors.

<!-- No hero, no problem! --> The null hero's name is {{nullHero?.firstName}}

It works perfectly with long property paths too:


How to produce a range with step n in bash? (generate a sequence of numbers with increments)

Pure Bash, without an extra process:

for (( COUNTER=0; COUNTER<=10; COUNTER+=2 )); do
    echo $COUNTER

MySQL user DB does not have password columns - Installing MySQL on OSX

One pitfall I fell into is there is no password field now, it has been renamed so:

update user set password=PASSWORD("YOURPASSWORDHERE") where user='root';

Should now be:

update user set authentication_string=password('YOURPASSWORDHERE') where user='root';

Abort a git cherry-pick?

Try also with '--quit' option, which allows you to abort the current operation and further clear the sequencer state.

--quit Forget about the current operation in progress. Can be used to clear the sequencer state after a failed cherry-pick or revert.

--abort Cancel the operation and return to the pre-sequence state.

use help to see the original doc with more details, $ git help cherry-pick

I would avoid 'git reset --hard HEAD' that is too harsh and you might ended up doing some manual work.


More of a comment link for suggested further reading...A really good blog article which benchmarks various ways of accomplishing this task can be found here.

They use a few techniques: "Insert Where Not Exists", "Merge" statement, "Insert Except", and your typical "left join" to see which way is the fastest to accomplish this task.

The example code used for each technique is as follows (straight copy/paste from their page) :

INSERT INTO #table1 (Id, guidd, TimeAdded, ExtraData)
SELECT Id, guidd, TimeAdded, ExtraData
FROM #table2
WHERE NOT EXISTS (Select Id, guidd From #table1 WHERE =
MERGE #table1 as [Target]
USING  (select Id, guidd, TimeAdded, ExtraData from #table2) as [Source]
(id, guidd, TimeAdded, ExtraData)
    on [Target].id =[Source].id
    INSERT (id, guidd, TimeAdded, ExtraData)
    VALUES ([Source].id, [Source].guidd, [Source].TimeAdded, [Source].ExtraData);
INSERT INTO #table1 (id, guidd, TimeAdded, ExtraData)
SELECT id, guidd, TimeAdded, ExtraData from #table2
SELECT id, guidd, TimeAdded, ExtraData from #table1
INSERT INTO #table1 (id, guidd, TimeAdded, ExtraData)
SELECT, #table2.guidd, #table2.TimeAdded, #table2.ExtraData
FROM #table2
LEFT JOIN #table1 on =
WHERE is null

It's a good read for those who are looking for speed! On SQL 2014, the Insert-Except method turned out to be the fastest for 50 million or more records.

How to make a link open multiple pages when clicked

You can open multiple windows on single click... Try this..

<a href="http://--" 
     'http://--','','width=700,height=500'); ..// add more"
               >Click Here</a>`

How to get pixel data from a UIImage (Cocoa Touch) or CGImage (Core Graphics)?

FYI, I combined Keremk's answer with my original outline, cleaned-up the typos, generalized it to return an array of colors and got the whole thing to compile. Here is the result:

+ (NSArray*)getRGBAsFromImage:(UIImage*)image atX:(int)x andY:(int)y count:(int)count
    NSMutableArray *result = [NSMutableArray arrayWithCapacity:count];

    // First get the image into your data buffer
    CGImageRef imageRef = [image CGImage];
    NSUInteger width = CGImageGetWidth(imageRef);
    NSUInteger height = CGImageGetHeight(imageRef);
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    unsigned char *rawData = (unsigned char*) calloc(height * width * 4, sizeof(unsigned char));
    NSUInteger bytesPerPixel = 4;
    NSUInteger bytesPerRow = bytesPerPixel * width;
    NSUInteger bitsPerComponent = 8;
    CGContextRef context = CGBitmapContextCreate(rawData, width, height,
                    bitsPerComponent, bytesPerRow, colorSpace,
                    kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);

    CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);

    // Now your rawData contains the image data in the RGBA8888 pixel format.
    NSUInteger byteIndex = (bytesPerRow * y) + x * bytesPerPixel;
    for (int i = 0 ; i < count ; ++i)
        CGFloat alpha = ((CGFloat) rawData[byteIndex + 3] ) / 255.0f;
        CGFloat red   = ((CGFloat) rawData[byteIndex]     ) / alpha;
        CGFloat green = ((CGFloat) rawData[byteIndex + 1] ) / alpha;
        CGFloat blue  = ((CGFloat) rawData[byteIndex + 2] ) / alpha;
        byteIndex += bytesPerPixel;

        UIColor *acolor = [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
        [result addObject:acolor];


  return result;

How to close jQuery Dialog within the dialog?

better way is "destroy and remove" instead of "close" it will remove dialog's "html" from the DOM


'Access denied for user 'root'@'localhost' (using password: NO)'

  1. Change the password from present in C:\xampp\phpMyAdmin.
  2. Type mysql -u root -p in the command prompt.
  3. You will be asked to enter the password. Enter that password which you updated in the

What does the 'Z' mean in Unix timestamp '120314170138Z'?

The Z stands for 'Zulu' - your times are in UTC. From Wikipedia:

The UTC time zone is sometimes denoted by the letter Z—a reference to the equivalent nautical time zone (GMT), which has been denoted by a Z since about 1950. The letter also refers to the "zone description" of zero hours, which has been used since 1920 (see time zone history). Since the NATO phonetic alphabet and amateur radio word for Z is "Zulu", UTC is sometimes known as Zulu time. This is especially true in aviation, where Zulu is the universal standard.

Copy existing project with a new name in Android Studio

I'm following these steps and it's been working so far:

  1. Copy and paste the folder as used to.
  2. Open Android Studio (v3.0.1).
  3. Select Open an existing Project.
  4. Close the message that will pop up with title: "Import Gradle Projects".
  5. At left side on Android Tab go to: app -> java -> select the first folder (your project folder)
  6. Refactor => Rename... (Shift + F6)
  7. Rename Package, Select both options - Put the new folder's name in lowercase.
  8. Do Refactor
  9. Select: Sync Project with Gradle Files at toolbar.
  10. Build => Clean Project
  11. Go to app -> res -> values -> strings.xml, and change the app name at 2nd line.

Running code in main thread from another thread

Follow this method. Using this way you can simply update the UI from a background thread. runOnUiThread work on the main(UI) thread . I think this code snippet is less complex and easy, especially for beginners.

AsyncTask.execute(new Runnable() {
            public void run() {

            //code you want to run on the background

           //the code you want to run on main thread
 MainActivity.this.runOnUiThread(new Runnable() {

                    public void run() {

/*the code you want to run after the background operation otherwise they will executed earlier and give you an error*/


in the case of a service

create a handler in the oncreate

 handler = new Handler();

then use it like this

 private void runOnUiThread(Runnable runnable) {;

How can I pad an integer with zeros on the left?

Found this example... Will test...

import java.text.DecimalFormat;
class TestingAndQualityAssuranceDepartment
    public static void main(String [] args)
        int x=1;
        DecimalFormat df = new DecimalFormat("00");

Tested this and:


Both work, for my purposes I think String.Format is better and more succinct.

$http get parameters does not work

The 2nd parameter in the get call is a config object. You want something like this:

    .get('accept.php', {
        params: {
            source: link,
            category_id: category
     .success(function (data,status) {
          $scope.info_show = data

See the Arguments section of$http for more detail

TypeError: $(...).on is not a function

If you are using old version of jQuery(< 1.7) then you can use "bind" instead of "on". This will only work in case you are using old version, since as of jQuery 3.0, "bind" has been deprecated.

When to use: Java 8+ interface default method, vs. abstract method

Regarding your query of

So when should interface with default methods be used and when should an abstract class be used? Are the abstract classes still useful in that scenario?

java documentation provides perfect answer.

Abstract Classes Compared to Interfaces:

Abstract classes are similar to interfaces. You cannot instantiate them, and they may contain a mix of methods declared with or without an implementation.

However, with abstract classes, you can declare fields that are not static and final, and define public, protected, and private concrete methods.

With interfaces, all fields are automatically public, static, and final, and all methods that you declare or define (as default methods) are public. In addition, you can extend only one class, whether or not it is abstract, whereas you can implement any number of interfaces.

Use cases for each of them have been explained in below SE post:

What is the difference between an interface and abstract class?

Are the abstract classes still useful in that scenario?

Yes. They are still useful. They can contain non-static, non-final methods and attributes (protected, private in addition to public), which is not possible even with Java-8 interfaces.

Route [login] not defined

Replace in your views (blade files) all

{{route('/')}} ----- by ----> {{url('/')}}

How can I call a shell command in my Perl script?

You might want to look into open2 and open3 in case you need bidirectional communication.

mysql datetime comparison

But this is obviously performing a 'string' comparison

No. The string will be automatically cast into a DATETIME value.

See 11.2. Type Conversion in Expression Evaluation.

When an operator is used with operands of different types, type conversion occurs to make the operands compatible. Some conversions occur implicitly. For example, MySQL automatically converts numbers to strings as necessary, and vice versa.

How to check if a string contains an element from a list in Python

Use list comprehensions if you want a single line solution. The following code returns a list containing the url_string when it has the extensions .doc, .pdf and .xls or returns empty list when it doesn't contain the extension.

print [url_string for extension in extensionsToCheck if(extension in url_string)]

NOTE: This is only to check if it contains or not and is not useful when one wants to extract the exact word matching the extensions.

How to preserve insertion order in HashMap?

HashMap is unordered per the second line of the documentation:

This class makes no guarantees as to the order of the map; in particular, it does not guarantee that the order will remain constant over time.

Perhaps you can do as aix suggests and use a LinkedHashMap, or another ordered collection. This link can help you find the most appropriate collection to use.

JQuery: dynamic height() with window resize()

I feel like there should be a no javascript solution, but how is this?

$(window).resize(function() {
    $('#content').height($(window).height() - 46);


Found 'OR 1=1/* sql injection in my newsletter database

It probably aimed to select all the informations in your table. If you use this kind of query (for example in PHP) :

mysql_query("SELECT * FROM newsletter WHERE email = '$email'");

The email ' OR 1=1/* will give this kind of query :

mysql_query("SELECT * FROM newsletter WHERE email = '' OR 1=1/*");

So it selects all the rows (because 1=1 is always true and the rest of the query is 'commented'). But it was not successful

  • if strings used in your queries are escaped
  • if you don't display all the queries results on a page...

How to store custom objects in NSUserDefaults

If anybody is looking for a swift version:

1) Create a custom class for your data

class customData: NSObject, NSCoding {
let name : String
let url : String
let desc : String

init(tuple : (String,String,String)){ = tuple.0
    self.url = tuple.1
    self.desc = tuple.2
func getName() -> String {
    return name
func getURL() -> String{
    return url
func getDescription() -> String {
    return desc
func getTuple() -> (String,String,String) {
    return (,self.url,self.desc)

required init(coder aDecoder: NSCoder) { = aDecoder.decodeObjectForKey("name") as! String
    self.url = aDecoder.decodeObjectForKey("url") as! String
    self.desc = aDecoder.decodeObjectForKey("desc") as! String

func encodeWithCoder(aCoder: NSCoder) {
    aCoder.encodeObject(, forKey: "name")
    aCoder.encodeObject(self.url, forKey: "url")
    aCoder.encodeObject(self.desc, forKey: "desc")

2) To save data use following function:

func saveData()
        let data  = NSKeyedArchiver.archivedDataWithRootObject(custom)
        let defaults = NSUserDefaults.standardUserDefaults()
        defaults.setObject(data, forKey:"customArray" )

3) To retrieve:

if let data = NSUserDefaults.standardUserDefaults().objectForKey("customArray") as? NSData
             custom = NSKeyedUnarchiver.unarchiveObjectWithData(data) as! [customData]

Note: Here I am saving and retrieving an array of the custom class objects.

What is the simplest way to get indented XML with line breaks from XmlDocument?

Based on the other answers, I looked into XmlTextWriter and came up with the following helper method:

static public string Beautify(this XmlDocument doc)
    StringBuilder sb = new StringBuilder();
    XmlWriterSettings settings = new XmlWriterSettings
        Indent = true,
        IndentChars = "  ",
        NewLineChars = "\r\n",
        NewLineHandling = NewLineHandling.Replace
    using (XmlWriter writer = XmlWriter.Create(sb, settings)) {
    return sb.ToString();

It's a bit more code than I hoped for, but it works just peachy.

The simplest way to comma-delimit a list?

I didn't compile it... but should work (or be close to working).

public static <T> String toString(final List<T> list, 
                                  final String delim)
    final StringBuilder builder;

    builder = new StringBuilder();

    for(final T item : list)

    // kill the last delim
    builder.setLength(builder.length() - delim.length());

    return (builder.toString());

Add one year in current date PYTHON

Look at this:


import datetime

def addYears(date, years):
    result = date + datetime.timedelta(366 * years)
    if years > 0:
        while result.year - date.year > years or date.month < result.month or <
            result += datetime.timedelta(-1)
    elif years < 0:
        while result.year - date.year < years or date.month > result.month or >
            result += datetime.timedelta(1)
    print "input: %s output: %s" % (date, result)
    return result

Example usage:

addYears(,1,1), -1)
addYears(,1,1), 0)
addYears(,1,1), 1)
addYears(,1,1), -10)
addYears(,1,1), 0)
addYears(,1,1), 10)

And output of this example:

input: 2012-01-01 output: 2011-01-01
input: 2012-01-01 output: 2012-01-01
input: 2012-01-01 output: 2013-01-01
input: 2012-01-01 output: 2002-01-01
input: 2012-01-01 output: 2012-01-01
input: 2012-01-01 output: 2022-01-01

PHP DOMDocument loadHTML not encoding UTF-8 correctly

You could prefix a line enforcing utf-8 encoding, like this:

@$doc->loadHTML('<?xml version="1.0" encoding="UTF-8"?>' . "\n" . $profile);

And you can then continue with the code you already have, like:


Cannot truncate table because it is being referenced by a FOREIGN KEY constraint?

you can follow this step, By reseeding table you can delete the data of the table.

delete from table_name
dbcc checkident('table_name',reseed,0)

if some error comes then you have to reseed the primary table.

How do I round to the nearest 0.5?

Multiply your rating by 2, then round using Math.Round(rating, MidpointRounding.AwayFromZero), then divide that value by 2.

Math.Round(value * 2, MidpointRounding.AwayFromZero) / 2

Get The Current Domain Name With Javascript (Not the path, etc.)

If you are not interested in the host name (for example but in the domain name (for example, this works for valid host names:

function getDomainName(hostName)
    return hostName.substring(hostName.lastIndexOf(".", hostName.lastIndexOf(".") - 1) + 1);

How to read numbers separated by space using scanf

scanf uses any whitespace as a delimiter, so if you just say scanf("%d", &var) it will skip any whitespace and then read an integer (digits up to the next non-digit) and nothing more.

Note that whitespace is any whitespace -- spaces, tabs, newlines, or carriage returns. Any of those are whitespace and any one or more of them will serve to delimit successive integers.

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

It is very simple just go to panoramio website and then open World Map from panoramio website.Then go to specified location whichs latitude and longitude required.

Then you found latitude and longitude in address bar for example in this address.

lt=32.739485 =>latitude ln=70.491211 =>longitude

this Panoramio JavaScript API widget create a bounding box around a lat/long pair and then returning all photos with in those bounds.

Another type of Panoramio JavaScript API widget in which you can also change background color with example and code is here.

It does not show in composing mood.It show after publishing.

<div dir="ltr" style="text-align: center;" trbidi="on">
<script src=";hl=en"></script>
<div id="wapiblock" style="float: right; margin: 10px 15px"></div>
<script type="text/javascript">
var myRequest = {
  'tag': 'kahna',
  'rect': {'sw': {'lat': -30, 'lng': 10.5}, 'ne': {'lat': 50.5, 'lng': 30}}
  var myOptions = {
  'width': 300,
  'height': 200
var wapiblock = document.getElementById('wapiblock');
var photo_widget = new panoramio.PhotoWidget('wapiblock', myRequest, myOptions);

Definition of int64_t

a) Can you explain to me the difference between int64_t and long (long int)? In my understanding, both are 64 bit integers. Is there any reason to choose one over the other?

The former is a signed integer type with exactly 64 bits. The latter is a signed integer type with at least 32 bits.

b) I tried to look up the definition of int64_t on the web, without much success. Is there an authoritative source I need to consult for such questions? covers this here: The authoritative source, however, is the C++ standard (this particular bit can be found in §18.4 Integer types [cstdint]).

c) For code using int64_t to compile, I am including <iostream>, which doesn't make much sense to me. Are there other includes that provide a declaration of int64_t?

It is declared in <cstdint> or <cinttypes> (under namespace std), or in <stdint.h> or <inttypes.h> (in the global namespace).

How to change option menu icon in the action bar?

This works properly in my case:

Drawable drawable = ContextCompat.getDrawable(getApplicationContext(),

Remove Item in Dictionary based on Value

In my case I use this

  var key=dict.FirstOrDefault(m => m.Value == s).Key;

jQuery keypress() event not firing?

Ofcourse this is a closed issue, i would like to add something to your discussion

In mozilla i have observed a weird behaviour for this code

//my code 

the code is being triggered twice. When debugged i found that actually there are two events getting fired: 'keypress' and 'keydown'. I disabled one of the event and the code shown me expected behavior.

//my code

This works for all browsers and also there is no need to check for browser specific(if($.browser.mozilla){ }).

Hope this might be useful for someone