Programs & Examples On #Packer

Packer is a tool for creating identical machine images for multiple platforms from a single source configuration.

How can I kill whatever process is using port 8080 so that I can vagrant up?

I needed to kill processes on different ports so I created a bash script:

killPort() {
  PID=$(echo $(lsof -n -i4TCP:$1) | awk 'NR==1{print $11}')
  kill -9 $PID
}

Just add that to your .bashrc and run it like this:

killPort 8080

You can pass whatever port number you wish

git: can't push (unpacker error) related to permission issues

I was having trouble with this too, thinking my remote gitolite-admin was corrupted or something wrong.

My setup is Mac OS X (10.6.6) laptop with remote Ubuntu 10 server with gitolite.

It turned out that the problem was with my local checkout of gitolite-admin.

Despite the "unpack failed" error, it turned out the the problem was local.

I figured this out by checking it out again as gitolite-admin2, making a change, and the pushing.

Voila! It worked!

Matplotlib subplots_adjust hspace so titles and xlabels don't overlap?

You can use plt.subplots_adjust to change the spacing between the subplots Link

subplots_adjust(left=None, bottom=None, right=None, top=None, wspace=None, hspace=None)

left  = 0.125  # the left side of the subplots of the figure
right = 0.9    # the right side of the subplots of the figure
bottom = 0.1   # the bottom of the subplots of the figure
top = 0.9      # the top of the subplots of the figure
wspace = 0.2   # the amount of width reserved for blank space between subplots
hspace = 0.2   # the amount of height reserved for white space between subplots

Error pushing to GitHub - insufficient permission for adding an object to repository database

Check the repository: $ git remote -v

origin  ssh://[email protected]:2283/srv/git/repo.git (fetch)
origin  ssh://[email protected]:2283/srv/git/repo.git (push)

Note that there is a 'git@' substring here, it instructs git to authenticate as username 'git' on the remote server. If you omit this line, git will authenticate under different username, hence this error will occur.

How do I create a singleton service in Angular 2?

Just declare your service as provider in app.module.ts only.

It did the job for me.

providers: [Topic1Service,Topic2Service,...,TopicNService],

then either instanciate it using a constructor private parameter :

constructor(private topicService: TopicService) { }

or since if your service is used from html, the -prod option will claim:

Property 'topicService' is private and only accessible within class 'SomeComponent'.

add a member for your service and fill it with the instance recieved in the constructor:

export class SomeComponent {
  topicService: TopicService;
  constructor(private topicService: TopicService) { 
    this.topicService= topicService;
  }
}

Convert timestamp to date in MySQL query

If the registration field is indeed of type TIMESTAMP you should be able to just do:

$sql = "SELECT user.email, 
           info.name, 
           DATE(user.registration), 
           info.news
      FROM user, 
           info 
     WHERE user.id = info.id ";

and the registration should be showing as yyyy-mm-dd

Create a List of primitive int?

No there isn't any collection that can contain primitive types when Java Collection Framework is being used.

However, there are other java collections which support primitive types, such as: Trove, Colt, Fastutil, Guava

An example of how an arraylist with ints would be when Trove Library used is the following:

 TIntArrayList list= new TIntArrayList();

The performance of this list, when compared with the ArrayList of Integers from Java Collections is much better as the autoboxing/unboxing to the corresponding Integer Wrapper Class is not needed.

Cheap way to search a large text file for a string

If it is "pretty large" file, then access the lines sequentially and don't read the whole file into memory:

with open('largeFile', 'r') as inF:
    for line in inF:
        if 'myString' in line:
            # do_something

Function to return only alpha-numeric characters from string?

Rather than preg_replace, you could always use PHP's filter functions using the filter_var() function with FILTER_SANITIZE_STRING.

Verifying a specific parameter with Moq

If the verification logic is non-trivial, it will be messy to write a large lambda method (as your example shows). You could put all the test statements in a separate method, but I don't like to do this because it disrupts the flow of reading the test code.

Another option is to use a callback on the Setup call to store the value that was passed into the mocked method, and then write standard Assert methods to validate it. For example:

// Arrange
MyObject saveObject;
mock.Setup(c => c.Method(It.IsAny<int>(), It.IsAny<MyObject>()))
        .Callback<int, MyObject>((i, obj) => saveObject = obj)
        .Returns("xyzzy");

// Act
// ...

// Assert
// Verify Method was called once only
mock.Verify(c => c.Method(It.IsAny<int>(), It.IsAny<MyObject>()), Times.Once());
// Assert about saveObject
Assert.That(saveObject.TheProperty, Is.EqualTo(2));

Angular ngClass and click event for toggling class

We can also use ngClass to assign multiple CSS classes based on multiple conditions as below:

<div
  [ngClass]="{
  'class-name': trueCondition,
  'other-class': !trueCondition
}"
></div>

2D Euclidean vector rotations

Rotating a vector 90 degrees is particularily simple.

(x, y) rotated 90 degrees around (0, 0) is (-y, x).

If you want to rotate clockwise, you simply do it the other way around, getting (y, -x).

How to display list items on console window in C#

While the answers with List<T>.ForEach are very good.

I found String.Join<T>(string separator, IEnumerable<T> values) method more useful.

Example :

List<string> numbersStrLst = new List<string>
            { "One", "Two", "Three","Four","Five"};

Console.WriteLine(String.Join(", ", numbersStrLst));//Output:"One, Two, Three, Four, Five"

int[] numbersIntAry = new int[] {1, 2, 3, 4, 5};
Console.WriteLine(String.Join("; ", numbersIntAry));//Output:"1; 2; 3; 4; 5"

Remarks :

If separator is null, an empty string (String.Empty) is used instead. If any member of values is null, an empty string is used instead.

Join(String, IEnumerable<String>) is a convenience method that lets you concatenate each element in an IEnumerable(Of String) collection without first converting the elements to a string array. It is particularly useful with Language-Integrated Query (LINQ) query expressions.

This should work just fine for the problem, whereas for others, having array values. Use other overloads of this same method, String.Join Method (String, Object[])

Reference: https://msdn.microsoft.com/en-us/library/dd783876(v=vs.110).aspx

Get url without querystring

My way:

new UriBuilder(url) { Query = string.Empty }.ToString()

or

new UriBuilder(url) { Query = string.Empty }.Uri

spark submit add multiple jars in classpath

Just use the --jars parameter. Spark will share those jars (comma-separated) with the executors.

How do I define and use an ENUM in Objective-C?

This is how Apple does it for classes like NSString:

In the header file:

enum {
    PlayerStateOff,
    PlayerStatePlaying,
    PlayerStatePaused
};

typedef NSInteger PlayerState;

Refer to Coding Guidelines at http://developer.apple.com/

SQL UPDATE all values in a field with appended string CONCAT not working

convert the NULL values with empty string by wrapping it in COALESCE

"UPDATE table SET data = CONCAT(COALESCE(`data`,''), 'a')"

OR

Use CONCAT_WS instead:

"UPDATE table SET data = CONCAT_WS(',',data, 'a')"

What's the difference between a Python module and a Python package?

Any Python file is a module, its name being the file's base name without the .py extension. A package is a collection of Python modules: while a module is a single Python file, a package is a directory of Python modules containing an additional __init__.py file, to distinguish a package from a directory that just happens to contain a bunch of Python scripts. Packages can be nested to any depth, provided that the corresponding directories contain their own __init__.py file.

The distinction between module and package seems to hold just at the file system level. When you import a module or a package, the corresponding object created by Python is always of type module. Note, however, when you import a package, only variables/functions/classes in the __init__.py file of that package are directly visible, not sub-packages or modules. As an example, consider the xml package in the Python standard library: its xml directory contains an __init__.py file and four sub-directories; the sub-directory etree contains an __init__.py file and, among others, an ElementTree.py file. See what happens when you try to interactively import package/modules:

>>> import xml
>>> type(xml)
<type 'module'>
>>> xml.etree.ElementTree
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'etree'
>>> import xml.etree
>>> type(xml.etree)
<type 'module'>
>>> xml.etree.ElementTree
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'ElementTree'
>>> import xml.etree.ElementTree
>>> type(xml.etree.ElementTree)
<type 'module'>
>>> xml.etree.ElementTree.parse
<function parse at 0x00B135B0>

In Python there also are built-in modules, such as sys, that are written in C, but I don't think you meant to consider those in your question.

Failed to import new Gradle project: failed to find Build Tools revision *.0.0

This worked for me after i tryed many solutions:
For some reason the adb process didn't restart itself after installing new packages. Manualy killing adb.exe and attempt to import the project another time solved this problem for me.

Jquery Setting Value of Input Field

You just write this script. use input element for this.

$("input").val("valuesgoeshere"); 

or by id="fsd" you write this code.

$("input").val(document.getElementById("fsd").innerHTML);

When to use .First and when to use .FirstOrDefault with LINQ?

.First() will throw an exception if there's no row to be returned, while .FirstOrDefault() will return the default value (NULL for all reference types) instead.

So if you're prepared and willing to handle a possible exception, .First() is fine. If you prefer to check the return value for != null anyway, then .FirstOrDefault() is your better choice.

But I guess it's a bit of a personal preference, too. Use whichever makes more sense to you and fits your coding style better.

Xcode/Simulator: How to run older iOS version?

If you have iAds in your binary you will not be able to run it on anything before iOS 4.0 and it will be rejected if you try and submit a binary like this.

You can still run the simulator from 3.2 onwards after upgrading.

In the iPhone Simulator try selecting Hardware -> Version -> 3.2

How to change visibility of layout programmatically

Use this Layout in your xml file

<LinearLayout
  android:id="@+id/contacts_type"
  android:orientation="horizontal"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:visibility="gone">
</LinearLayout>

Define your layout in .class file

 LinearLayout linearLayout = (LinearLayout) findViewById(R.id.contacts_type);

Now if you want to display this layout just write

 linearLayout.setVisibility(View.VISIBLE);

and if you want to hide layout just write

 linearLayout.setVisibility(View.INVISIBLE);

How to configure PostgreSQL to accept all incoming connections

0.0.0.0/0 for all IPv4 addresses

::0/0 for all IPv6 addresses

all to match any IP address

samehost to match any of the server's own IP addresses

samenet to match any address in any subnet that the server is directly connected to.

e.g.

host    all             all             0.0.0.0/0            md5

Calculate distance in meters when you know longitude and latitude in java

Based on another question on stackoverflow, I got this code.. This calculates the result in meters, not in miles :)

 public static float distFrom(float lat1, float lng1, float lat2, float lng2) {
    double earthRadius = 6371000; //meters
    double dLat = Math.toRadians(lat2-lat1);
    double dLng = Math.toRadians(lng2-lng1);
    double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
               Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) *
               Math.sin(dLng/2) * Math.sin(dLng/2);
    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
    float dist = (float) (earthRadius * c);

    return dist;
    }

How to show code but hide output in RMarkdown?

As @ J_F answered in the comments, using {r echo = T, results = 'hide'}.

I wanted to expand on their answer - there are great resources you can access to determine all possible options for your chunk and output display - I keep a printed copy at my desk!

You can find them either on the RStudio Website under Cheatsheets (look for the R Markdown cheatsheet and R Markdown Reference Guide) or, in RStudio, navigate to the "Help" tab, choose "Cheatsheets", and look for the same documents there.

Finally to set default chunk options, you can run (in your first chunk) something like the following code if you want most chunks to have the same behavior:

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = T,
                      results = "hide")
```

Later, you can modify the behavior of individual chunks like this, which will replace the default value for just the results option.

```{r analysis, results="markup"}
# code here
```

What is the difference between Collection and List in Java?

Collection is the main interface of Java Collections hierarchy and List(Sequence) is one of the sub interfaces that defines an ordered collection.

AngularJs ReferenceError: $http is not defined

Probably you haven't injected $http service to your controller. There are several ways of doing that.

Please read this reference about DI. Then it gets very simple:

function MyController($scope, $http) {
   // ... your code
}

Using a different font with twitter bootstrap

Hi you can create a customized build on bootstrap, just change the font name in the following pages

Bootstrap 2.3.2 http://getbootstrap.com/2.3.2/customize.html#variables

Bootstrap 3 http://getbootstrap.com/customize/#less-variables

After that, make sure to use proper @font-face in a css file and link that to your page. Or you could use font kit generators.

Resizing a button

If you want to call a different size for the button inline, you would probably do it like this:

<div class="button" style="width:60px;height:100px;">This is a button</div>

Or, a better way to have different sizes (say there will be 3 standard sizes for the button) would be to have classes just for size.

For example, you would call your button like this:

<div class="button small">This is a button</div>

And in your CSS

.button.small { width: 60px; height: 100px; }

and just create classes for each size you wish to have. That way you still have the perks of using a stylesheet in case say, you want to change the size of all the small buttons at once.

Android: How to create a Dialog without a title?

Use like this:

Dialog dialog = new Dialog(this);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE); 

This will remove any title bar from dialog window.

Finding first blank row, then writing to it

If you mean the row number after the last row that is used, you can find it with this:

Dim unusedRow As Long
unusedRow = Cells.SpecialCells(xlCellTypeLastCell).Offset(1, 0).Row

If you mean a row that happens to be blank with data after it... it gets more complicated.

Here's a function I wrote which will give you the actual row number of the first row that is blank for the provided worksheet.

Function firstBlankRow(ws As Worksheet) As Long
'returns the row # of the row after the last used row
'Or the first row with no data in it
    Dim rw As Range
    For Each rw In ws.UsedRange.Rows
        If rw.Address = ws.Range(rw.Address).SpecialCells(xlCellTypeBlanks). _
            Address Then

                firstBlankRow = rw.Row
                Exit For
        End If
    Next
    If firstBlankRow = 0 Then
        firstBlankRow = ws.Cells.SpecialCells(xlCellTypeLastCell). _
                    Offset(1, 0).Row
    End If
End Function

Usage example: firstblankRow(thisworkbook.Sheets(1)) or pass any worksheet.

Edit: As ooo pointed out, this will error if there are no blank cells in your used range.

Using C++ base class constructors?

Prefer initialization:

class C : public A
{
public:
    C(const string &val) : A(anInt) {}
};

In C++11, you can use inheriting constructors (which has the syntax seen in your example D).

Update: Inheriting Constructors have been available in GCC since version 4.8.


If you don't find initialization appealing (e.g. due to the number of possibilities in your actual case), then you might favor this approach for some TMP constructs:

class A
{
public: 
    A() {}
    virtual ~A() {}
    void init(int) { std::cout << "A\n"; }
};

class B : public A
{
public:
    B() : A() {}
    void init(int) { std::cout << "B\n"; }
};

class C : public A
{
public:
    C() : A() {}
    void init(int) { std::cout << "C\n"; }
};

class D : public A
{
public:
    D() : A() {}
    using A::init;
    void init(const std::string& s) { std::cout << "D -> " << s << "\n"; }
};

int main()
{
    B b; b.init(10);
    C c; c.init(10);
    D d; d.init(10); d.init("a");

    return 0;
}

Numpy Resize/Rescale Image

One-line numpy solution for downsampling (by 2):

smaller_img = bigger_img[::2, ::2]

And upsampling (by 2):

bigger_img = smaller_img.repeat(2, axis=0).repeat(2, axis=1)

(this asssumes HxWxC shaped image. h/t to L. Kärkkäinen in the comments above. note this method only allows whole integer resizing (e.g., 2x but not 1.5x))

PHP string concatenation

I think this code should work fine

while ($personCount < 10) {
$result = $personCount . "people ';
$personCount++;
}
// do not understand why do you need the (+) with the result.
echo $result;

Laravel 5: Retrieve JSON array from $request

My jQuery ajax settings:

        $.ajax({
        headers: {'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')},
        url: url,
        dataType: "json",
        type: "post",
        data: params,
        success: function (resp){
            ....
        },
        error: responseFunc
    });

And now i am able to get the request via $request->all() in Laravel

dataType: "json"

is the important part in the ajax request to handle the response as an json object and not string.

Displaying a Table in Django from Database

$ pip install django-tables2

settings.py

INSTALLED_APPS , 'django_tables2'
TEMPLATES.OPTIONS.context-processors , 'django.template.context_processors.request'

models.py

class hotel(models.Model):
     name = models.CharField(max_length=20)

views.py

from django.shortcuts import render

def people(request):
    istekler = hotel.objects.all()
    return render(request, 'list.html', locals())

list.html

{# yonetim/templates/list.html #}
{% load render_table from django_tables2 %}
{% load static %}
<!doctype html>
<html>
    <head>
        <link rel="stylesheet" href="{% static 
'ticket/static/css/screen.css' %}" />
    </head>
    <body>
        {% render_table istekler %}
    </body>
</html>

How to change permissions for a folder and its subfolders/files in one step?

I think Adam was asking how to change umask value for all processes that tying to operate on /opt/lampp/htdocs directory.

The user file-creation mode mask (umask) is use to determine the file permission for newly created files. It can be used to control the default file permission for new files.

so if you will use some kind of ftp program to upload files into /opt/lampp/htdocs you need to configure your ftp server to use umask you want.

If files / directories be created for example by php, you need to modify php code

<?php
umask(0022);
// other code
?>

if you will create new files / folders from your bash session, you can set umask value in your shell profile ~/.bashrc Or you can set up umask in /etc/bashrc or /etc/profile file for all users. add the following to file: umask 022

Sample umask Values and File Creation Permissions
If umask value set to   User permission     Group permission     Others permission
000                         all              all                   all
007                         all              all                   none
027                         all          read / execute            none

And to change permissions for already created files you can use find. Hope this helps.

cast or convert a float to nvarchar?

You can also do something:

SELECT CAST(CAST(34512367.392 AS decimal(30,9)) AS NVARCHAR(100))

Output: 34512367.392000000

Run cmd commands through Java

Once you get the reference to Process, you can call getOutpuStream on it to get the standard input of the cmd prompt. Then you can send any command over the stream using write method as with any other stream.

Note that it is process.getOutputStream() which is connected to the stdin on the spawned process. Similarly, to get the output of any command, you will need to call getInputStream and then read over this as any other input stream.

JNI converting jstring to char *

Thanks Jason Rogers's answer first.

In Android && cpp should be this:

const char *nativeString = env->GetStringUTFChars(javaString, nullptr);

// use your string

env->ReleaseStringUTFChars(javaString, nativeString);

Can fix this errors:

1.error: base operand of '->' has non-pointer type 'JNIEnv {aka _JNIEnv}'

2.error: no matching function for call to '_JNIEnv::GetStringUTFChars(JNIEnv*&, _jstring*&, bool)'

3.error: no matching function for call to '_JNIEnv::ReleaseStringUTFChars(JNIEnv*&, _jstring*&, char const*&)'

4.add "env->DeleteLocalRef(nativeString);" at end.

How do I use Maven through a proxy?

I know this is not really an answer to the question, but it might be worth knowing for someone searching this post. It is also possible to install a Maven repository proxy like nexus.

Your maven would be configured to contact the local Nexus proxy, and Nexus would then retrieve (and cache) the artifacts. It can be configured through a web interface and has support for (http) proxies).

This can be an advantage, especially in a company setting, as artefacts are locally available and can be downloaded fast, and you are not that dependent on the availability of external Maven repositories anymore.

To link back to the question; with Nexus there is a nice GUI for the proxy configuration, and it needs to be done on one place only, and not for every developer.

git replacing LF with CRLF

Many text-editors allow you to change to LF, see Atom instructions below. Simple and explicit.


Click CRLF on bottom right:

enter image description here

Select LF in dropdown on top:

enter image description here

Android 'Unable to add window -- token null is not for an application' exception

I got the same exception. what i do to fix this is to pass instance of the dialog as parameter into function and use it instead of pass only context then using getContext(). this solution solve my problem, hope it can help

Rename package in Android Studio

I found another way that works or an extra step to some of the answers here especially if you want to change the domain as well. It works in Android Studio 1.4. This is what I did:

  1. Open Manifest.xml and change the package name to what you want.
  2. Open your app build.gradle file and change the Application Id in defaultConfig to the same name as in manifest and rebuild the project.
  3. If still an issue, open a file under the package name, go to the package breadcrumbs (i.e. package declaration at head of file) and set your cursor to the domain you want to change and hit "Shift + F6", it would come out with a dialog with multiple use warnings, click on "Rename packages" and then click on "Do Refactor" it should rename everything including the R.Java files.

So for example if you want to rename "com.example.app" to "com.YourDomain.app", open a file under the package to be renamed, in the package breadcrumbs, set your cursor to "example" part of the domain and hit Shift + F6 and rename package to "YourDomain".

Setting Windows PATH for Postgres tools

All you need to do is to change the PATH variable to include the bin directory of your PostgreSQL installation.

An explanation on how to change environment variables is here:

http://support.microsoft.com/kb/310519
http://www.computerhope.com/issues/ch000549.htm

To verify that the path is set correctly, you can use:

echo %PATH%

on the commandline.

Java String array: is there a size of method?

In java there is a length field that you can use on any array to find out it's size:

    String[] s = new String[10];
    System.out.println(s.length);

What are FTL files

FTL stands for FreeMarker Template.

It is very useful when you want to follow the MVC (Model View Controller) pattern.

The idea behind using the MVC pattern for dynamic Web pages is that you separate the designers (HTML authors) from the programmers.

Xcode Project vs. Xcode Workspace - Differences

I think there are three key items you need to understand regarding project structure: Targets, projects, and workspaces. Targets specify in detail how a product/binary (i.e., an application or library) is built. They include build settings, such as compiler and linker flags, and they define which files (source code and resources) actually belong to a product. When you build/run, you always select one specific target.

It is likely that you have a few targets that share code and resources. These different targets can be slightly different versions of an app (iPad/iPhone, different brandings,…) or test cases that naturally need to access the same source files as the app. All these related targets can be grouped in a project. While the project contains the files from all its targets, each target picks its own subset of relevant files. The same goes for build settings: You can define default project-wide settings in the project, but if one of your targets needs different settings, you can always override them there:

Shared project settings that all targets inherit, unless they overwrite it

Shared project settings that all targets inherit, unless they override it

Concrete target settings: PSE iPhone overwrites the project’s Base SDK setting

Concrete target settings: PSE iPhone overrides the project’s Base SDK setting

In Xcode, you always open projects (or workspaces, but not targets), and all the targets it contains can be built/run, but there’s no way/definition of building a project, so every project needs at least one target in order to be more than just a collection of files and settings.

Select one of the project’s targets to run

Select one of the project’s targets to run

In a lot of cases, projects are all you need. If you have a dependency that you build from source, you can embed it as a subproject. Subprojects can be opened separately or within their super project.

demoLib is a subprojec

demoLib is a subproject

If you add one of the subproject’s targets to the super project’s dependencies, the subproject will be automatically built unless it has remained unchanged. The advantage here is that you can edit files from both your project and your dependencies in the same Xcode window, and when you build/run, you can select from the project’s and its subprojects’ targets:

Running targets from a subproject

If, however, your library (the subproject) is used by a variety of other projects (or their targets, to be precise), it makes sense to put it on the same hierarchy level – that’s what workspaces are for. Workspaces contain and manage projects, and all the projects it includes directly (i.e., not their subprojects) are on the same level and their targets can depend on each other (projects’ targets can depend on subprojects’ targets, but not vice versa).

Workspace structure

Workspace structure

In this example, both apps (AnotherApplication / ProjectStructureExample) can reference the demoLib project’s targets. This would also be possible by including the demoLib project in both other projects as a subproject (which is a reference only, so no duplication necessary), but if you have lots of cross-dependencies, workspaces make more sense. If you open a workspace, you can choose from all projects’ targets when building/running.

Running targets from a workspace

You can still open your project files separately, but it is likely their targets won’t build because Xcode cannot resolve the dependencies unless you open the workspace file. Workspaces give you the same benefit as subprojects: Once a dependency changes, Xcode will rebuild it to make sure it’s up-to-date (although I have had some issues with that, it doesn’t seem to work reliably).

Your questions in a nutshell:

1) Projects contain files (code/resouces), settings, and targets that build products from those files and settings. Workspaces contain projects which can reference each other.

2) Both are responsible for structuring your overall project, but on different levels.

3) I think projects are sufficient in most cases. Don’t use workspaces unless there’s a specific reason. Plus, you can always embed your project in a workspace later.

4) I think that’s what the above text is for…

There’s one remark for 3): CocoaPods, which automatically handles 3rd party libraries for you, uses workspaces. Therefore, you have to use them, too, when you use CocoaPods (which a lot of people do).

How to get all key in JSON object (javascript)

var jsonData = { Name: "Ricardo Vasquez", age: "46", Email: "[email protected]" };

for (x in jsonData) {   
  console.log(x +" => "+ jsonData[x]);  
  alert(x +" => "+  jsonData[x]);  
  }

OpenCV Error: (-215)size.width>0 && size.height>0 in function imshow

This error message

error: (-215)size.width>0 && size.height>0 in function imshow

simply means that imshow() is not getting video frame from input-device. You can try using

cap = cv2.VideoCapture(1) 

instead of

cap = cv2.VideoCapture(0) 

& see if the problem still persists.

how to make a html iframe 100% width and height?

this code probable help you .

<iframe src="" onload="this.width=screen.width;this.height=screen.height;">

How to convert milliseconds to "hh:mm:ss" format?

DateFormat df = new SimpleDateFormat("HH:mm:ss");
String formatted = df.format(aDateObject);

data.table vs dplyr: can one do something well the other can't or does poorly?

Here's my attempt at a comprehensive answer from the dplyr perspective, following the broad outline of Arun's answer (but somewhat rearranged based on differing priorities).

Syntax

There is some subjectivity to syntax, but I stand by my statement that the concision of data.table makes it harder to learn and harder to read. This is partly because dplyr is solving a much easier problem!

One really important thing that dplyr does for you is that it constrains your options. I claim that most single table problems can be solved with just five key verbs filter, select, mutate, arrange and summarise, along with a "by group" adverb. That constraint is a big help when you're learning data manipulation, because it helps order your thinking about the problem. In dplyr, each of these verbs is mapped to a single function. Each function does one job, and is easy to understand in isolation.

You create complexity by piping these simple operations together with %>%. Here's an example from one of the posts Arun linked to:

diamonds %>%
  filter(cut != "Fair") %>%
  group_by(cut) %>%
  summarize(
    AvgPrice = mean(price),
    MedianPrice = as.numeric(median(price)),
    Count = n()
  ) %>%
  arrange(desc(Count))

Even if you've never seen dplyr before (or even R!), you can still get the gist of what's happening because the functions are all English verbs. The disadvantage of English verbs is that they require more typing than [, but I think that can be largely mitigated by better autocomplete.

Here's the equivalent data.table code:

diamondsDT <- data.table(diamonds)
diamondsDT[
  cut != "Fair", 
  .(AvgPrice = mean(price),
    MedianPrice = as.numeric(median(price)),
    Count = .N
  ), 
  by = cut
][ 
  order(-Count) 
]

It's harder to follow this code unless you're already familiar with data.table. (I also couldn't figure out how to indent the repeated [ in a way that looks good to my eye). Personally, when I look at code I wrote 6 months ago, it's like looking at a code written by a stranger, so I've come to prefer straightforward, if verbose, code.

Two other minor factors that I think slightly decrease readability:

  • Since almost every data table operation uses [ you need additional context to figure out what's happening. For example, is x[y] joining two data tables or extracting columns from a data frame? This is only a small issue, because in well-written code the variable names should suggest what's happening.

  • I like that group_by() is a separate operation in dplyr. It fundamentally changes the computation so I think should be obvious when skimming the code, and it's easier to spot group_by() than the by argument to [.data.table.

I also like that the the pipe isn't just limited to just one package. You can start by tidying your data with tidyr, and finish up with a plot in ggvis. And you're not limited to the packages that I write - anyone can write a function that forms a seamless part of a data manipulation pipe. In fact, I rather prefer the previous data.table code rewritten with %>%:

diamonds %>% 
  data.table() %>% 
  .[cut != "Fair", 
    .(AvgPrice = mean(price),
      MedianPrice = as.numeric(median(price)),
      Count = .N
    ), 
    by = cut
  ] %>% 
  .[order(-Count)]

And the idea of piping with %>% is not limited to just data frames and is easily generalised to other contexts: interactive web graphics, web scraping, gists, run-time contracts, ...)

Memory and performance

I've lumped these together, because, to me, they're not that important. Most R users work with well under 1 million rows of data, and dplyr is sufficiently fast enough for that size of data that you're not aware of processing time. We optimise dplyr for expressiveness on medium data; feel free to use data.table for raw speed on bigger data.

The flexibility of dplyr also means that you can easily tweak performance characteristics using the same syntax. If the performance of dplyr with the data frame backend is not good enough for you, you can use the data.table backend (albeit with a somewhat restricted set of functionality). If the data you're working with doesn't fit in memory, then you can use a database backend.

All that said, dplyr performance will get better in the long-term. We'll definitely implement some of the great ideas of data.table like radix ordering and using the same index for joins & filters. We're also working on parallelisation so we can take advantage of multiple cores.

Features

A few things that we're planning to work on in 2015:

  • the readr package, to make it easy to get files off disk and in to memory, analogous to fread().

  • More flexible joins, including support for non-equi-joins.

  • More flexible grouping like bootstrap samples, rollups and more

I'm also investing time into improving R's database connectors, the ability to talk to web apis, and making it easier to scrape html pages.

How to escape a JSON string containing newline characters using JavaScript?

I used the built in jQuery.serialize() to extract the value from a textarea to urlencode the input. The pro part is that you don't have to search replace every special char on your own and i also keep the newlines and escapes html. For serialize to work it seems the input field needs to have a name attribute though and it also adds same attribute to the escaped string which needs to be replaced away. Might not be what you are looking for but it works for me.

var myinputfield = jQuery("#myinputfield"); 
var text = myinputfield.serialize();
text = text.replace(myinputfield.attr('name') + '=','');

Does Python have a package/module management system?

It's called setuptools. You run it with the "easy_install" command.

You can find the directory at http://pypi.python.org/

Updating a date in Oracle SQL table

Here is how you set the date and time:

update user set expiry_date=TO_DATE('31/DEC/2017 12:59:59', 'dd/mm/yyyy hh24:mi:ss') where id=123;

How can I pass a username/password in the header to a SOAP WCF Service

The answers above are so wrong! DO NOT add custom headers. Judging from your sample xml, it is a standard WS-Security header. WCF definitely supports it out of the box. When you add a service reference you should have basicHttpBinding binding created for you in the config file. You will have to modify it to include security element with mode TransportWithMessageCredential and message element with clientCredentialType = UserName:

<basicHttpBinding>
  <binding name="usernameHttps">
    <security mode="TransportWithMessageCredential">
      <message clientCredentialType="UserName"/>
    </security>
  </binding>
</basicHttpBinding>

The config above is telling WCF to expect userid/password in the SOAP header over HTTPS. Then you can set id/password in your code before making a call:

var service = new MyServiceClient();
service.ClientCredentials.UserName.UserName = "username";
service.ClientCredentials.UserName.Password = "password";

Unless this particular service provider deviated from the standard, it should work.

How can I mock requests and the response?

Here is what worked for me:

import mock
@mock.patch('requests.get', mock.Mock(side_effect = lambda k:{'aurl': 'a response', 'burl' : 'b response'}.get(k, 'unhandled request %s'%k)))

How to make a edittext box in a dialog

I know its too late to answer this question but for others who are searching for some thing similar to this here is a simple code of an alertbox with an edittext

AlertDialog.Builder alert = new AlertDialog.Builder(this); 

or

new AlertDialog.Builder(mContext, R.style.MyCustomDialogTheme);

if you want to change the theme of the dialog.

final EditText edittext = new EditText(ActivityContext);
alert.setMessage("Enter Your Message");
alert.setTitle("Enter Your Title");

alert.setView(edittext);

alert.setPositiveButton("Yes Option", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog, int whichButton) {
        //What ever you want to do with the value
        Editable YouEditTextValue = edittext.getText();
        //OR
        String YouEditTextValue = edittext.getText().toString();
    }
});

alert.setNegativeButton("No Option", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog, int whichButton) {
        // what ever you want to do with No option.
    }
});

alert.show();

How to properly make a http web GET request

Simpliest way for my opinion

  var web = new WebClient();
  var url = $"{hostname}/LoadDataSync?systemID={systemId}";
  var responseString = web.DownloadString(url);

OR

 var bytes = web.DownloadData(url);

How do you add swap to an EC2 instance?

Swap should take place on the Instance Storage (ephemeral) disk and not an EBS device. Swapping will cause a lot of IO and will increase cost on EBS. EBS is also slower than the Instance Store and the Instance Store comes free with certain types of EC2 Instances.

It will usually be mounted to /mnt but if not run

sudo mount /dev/xvda2 /mnt

To then create a swap file on this device do the following for a 4GB swapfile

sudo dd if=/dev/zero of=/mnt/swapfile bs=1M count=4096

Make sure no other user can view the swap file

sudo chown root:root /mnt/swapfile
sudo chmod 600 /mnt/swapfile

Make and Flag as swap

sudo mkswap /mnt/swapfile
sudo swapon /mnt/swapfile

Add/Make sure the following are in your /etc/fstab

/dev/xvda2      /mnt    auto    defaults,nobootwait,comment=cloudconfig 0   2
/mnt/swapfile swap swap defaults 0 0

lastly enable swap

sudo swapon -a

Is there a template engine for Node.js?

Try "vash" - asp.net mvc like razor syntax for node.js

https://github.com/kirbysayshi/Vash

also checkout: http://haacked.com/archive/2011/01/06/razor-syntax-quick-reference.aspx


// sample
var tmpl = vash.compile('<hr/>@model.a,@model.b<hr/>');
var html = tmpl({"a": "hello", "b": "world"});
res.write(html);

Use String.split() with multiple delimiters

For two char sequence as delimeters "AND" and "OR" this should be worked. Don't forget to trim while using.

 String text ="ISTANBUL AND NEW YORK AND PARIS OR TOKYO AND MOSCOW";
 String[] cities = text.split("AND|OR"); 

Result : cities = {"ISTANBUL ", " NEW YORK ", " PARIS ", " TOKYO ", " MOSCOW"}

Error:(23, 17) Failed to resolve: junit:junit:4.12

I was having same problem.

  • 1 option: Download junit 4.12.jar and copy it in your lib folder and restart android studio. Benefit u don't have to create any new project

  • 2 option: Create a new project having a internet connections and copy all the java and XML code in the newly created project. Benefit this problem will be solved permantly

Verify ImageMagick installation

In Bash you can check if Imagick is an installed module:

$ php -m | grep imagick

If the response is blank it is not installed.

ldconfig error: is not a symbolic link

I ran into this issue with the Oracle 11R2 client. Not sure if the Oracle installer did this or someone did it here before i arrived. It was not 64-bit vs 32-bit, all was 64-bit.

The error was that libexpat.so.1 was not a symbolic link.

It turned out that there were two identical files, libexpat.so.1.5.2 and libexpat.so.1. Removing the offending file and making it a symlink to the 1.5.2 version caused the error to go away.

Makes sense that you'd want the well-known name to be a symlink to the current version. If you do this, it's less likely that you'll end up with a stale library.

Matching special characters and letters in regex

Add them to the allowed characters, but you'll need to escape some of them, such as -]/\

var pattern = /^[a-zA-Z0-9!@#$%^&*()_+\-=\[\]{};':"\\|,.<>\/?]*$/

That way you can remove any individual character you want to disallow.

Also, you want to include the start and end of string placemarkers ^ and $

Update:

As elclanrs understood (and the rest of us didn't, initially), the only special characters needing to be allowed in the pattern are &-._

/^[\w&.\-]+$/

[\w] is the same as [a-zA-Z0-9_]

Though the dash doesn't need escaping when it's at the start or end of the list, I prefer to do it in case other characters are added. Additionally, the + means you need at least one of the listed characters. If zero is ok (ie an empty value), then replace it with a * instead:

/^[\w&.\-]*$/

How can I slice an ArrayList out of an ArrayList in Java?

I have found a way if you know startIndex and endIndex of the elements one need to remove from ArrayList

Let al be the original ArrayList and startIndex,endIndex be start and end index to be removed from the array respectively:

al.subList(startIndex, endIndex + 1).clear();

Change type of varchar field to integer: "cannot be cast automatically to type integer"

There is no implicit (automatic) cast from text or varchar to integer (i.e. you cannot pass a varchar to a function expecting integer or assign a varchar field to an integer one), so you must specify an explicit cast using ALTER TABLE ... ALTER COLUMN ... TYPE ... USING:

ALTER TABLE the_table ALTER COLUMN col_name TYPE integer USING (col_name::integer);

Note that you may have whitespace in your text fields; in that case, use:

ALTER TABLE the_table ALTER COLUMN col_name TYPE integer USING (trim(col_name)::integer);

to strip white space before converting.

This shoud've been obvious from an error message if the command was run in psql, but it's possible PgAdmin-III isn't showing you the full error. Here's what happens if I test it in psql on PostgreSQL 9.2:

=> CREATE TABLE test( x varchar );
CREATE TABLE
=> insert into test(x) values ('14'), (' 42  ');
INSERT 0 2
=> ALTER TABLE test ALTER COLUMN x TYPE integer;
ERROR:  column "x" cannot be cast automatically to type integer
HINT:  Specify a USING expression to perform the conversion. 
=> ALTER TABLE test ALTER COLUMN x TYPE integer USING (trim(x)::integer);
ALTER TABLE        

Thanks @muistooshort for adding the USING link.

See also this related question; it's about Rails migrations, but the underlying cause is the same and the answer applies.

If the error still occurs, then it may be related not to column values, but indexes over this column or column default values might fail typecast. Indexes need to be dropped before ALTER COLUMN and recreated after. Default values should be changed appropriately.

Bootstrap 4 File Input

I just add this in my CSS file and it works:

.custom-file-label::after{content: 'New Text Button' !important;}


How can I tell if an algorithm is efficient?

Yes you can start with the Wikipedia article explaining the Big O notation, which in a nutshell is a way of describing the "efficiency" (upper bound of complexity) of different type of algorithms. Or you can look at an earlier answer where this is explained in simple english

Style disabled button with CSS

input[type="button"]:disabled,
input[type="submit"]:disabled,
input[type="reset"]:disabled,
{
  //  apply css here what u like it will definitely work...
}

how to add css class to html generic control div?

My approach would be:

/// <summary>
/// Appends CSS Class seprated by a space character
/// </summary>
/// <param name="control">Target control</param>
/// <param name="cssClass">CSS class name to append</param>
public static void AppendCss(HtmlGenericControl control, string cssClass)
{
    // Ensure CSS class is definied
    if (string.IsNullOrEmpty(cssClass)) return;

    // Append CSS class
    if (string.IsNullOrEmpty(control.Attributes["class"]))
    {
        // Set our CSS Class as only one
        control.Attributes["class"] = cssClass;
    }
    else
    {
        // Append new CSS class with space as seprator
        control.Attributes["class"] += (" " + cssClass);
    }
}

How can I get client information such as OS and browser

This code is based on the most voted question but I might be easier to use

public enum OS {

    WINDOWS,
    MAC,
    LINUX,
    ANDROID,
    IPHONE,
    UNKNOWN;

    public static OS valueOf(HttpServletRequest request) {

        final String userAgent = request.getHeader("User-Agent");
        final OS toReturn;

        if (userAgent == null || userAgent.isEmpty()) {
            toReturn = UNKNOWN;
        } else if (userAgent.toLowerCase().contains("windows")) {
            toReturn = WINDOWS;
        } else if (userAgent.toLowerCase().contains("mac")) {
            toReturn = MAC;
        } else if (userAgent.toLowerCase().contains("x11")) {
            toReturn = LINUX;
        } else if (userAgent.toLowerCase().contains("android")) {
            toReturn = ANDROID;
        } else if (userAgent.toLowerCase().contains("iphone")) {
            toReturn = IPHONE;
        } else {
            toReturn = UNKNOWN;
        }

        return toReturn;
    }

}

GCC C++ Linker errors: Undefined reference to 'vtable for XXX', Undefined reference to 'ClassName::ClassName()'

I had this error message. The problem was that I declared a virtual destructor in the header file, but the virtual functions' body was actually not implemented.

Adjust list style image position?

_x000D_
_x000D_
My solution:_x000D_
_x000D_
ul {_x000D_
    line-height: 1.3 !important;_x000D_
    li {_x000D_
        font-size: x-large;_x000D_
        position: relative;_x000D_
        &:before {_x000D_
            content: '';_x000D_
            display: block;_x000D_
            position: absolute;_x000D_
            top: 5px;_x000D_
            left: -25px;_x000D_
            height: 23px;_x000D_
            width: 23px;_x000D_
            background-image: url(../img/list-char.png) !important;_x000D_
            background-size: 23px;_x000D_
            background-repeat: no-repeat;_x000D_
        }_x000D_
    }_x000D_
}
_x000D_
_x000D_
_x000D_

How to transform numpy.matrix or array to scipy sparse matrix

In Python, the Scipy library can be used to convert the 2-D NumPy matrix into a Sparse matrix. SciPy 2-D sparse matrix package for numeric data is scipy.sparse

The scipy.sparse package provides different Classes to create the following types of Sparse matrices from the 2-dimensional matrix:

  1. Block Sparse Row matrix
  2. A sparse matrix in COOrdinate format.
  3. Compressed Sparse Column matrix
  4. Compressed Sparse Row matrix
  5. Sparse matrix with DIAgonal storage
  6. Dictionary Of Keys based sparse matrix.
  7. Row-based list of lists sparse matrix
  8. This class provides a base class for all sparse matrices.

CSR (Compressed Sparse Row) or CSC (Compressed Sparse Column) formats support efficient access and matrix operations.

Example code to Convert Numpy matrix into Compressed Sparse Column(CSC) matrix & Compressed Sparse Row (CSR) matrix using Scipy classes:

import sys                 # Return the size of an object in bytes
import numpy as np         # To create 2 dimentional matrix
from scipy.sparse import csr_matrix, csc_matrix 
# csr_matrix: used to create compressed sparse row matrix from Matrix
# csc_matrix: used to create compressed sparse column matrix from Matrix

create a 2-D Numpy matrix

A = np.array([[1, 0, 0, 0, 0, 0],\
              [0, 0, 2, 0, 0, 1],\
              [0, 0, 0, 2, 0, 0]])
print("Dense matrix representation: \n", A)
print("Memory utilised (bytes): ", sys.getsizeof(A))
print("Type of the object", type(A))

Print the matrix & other details:

Dense matrix representation: 
 [[1 0 0 0 0 0]
 [0 0 2 0 0 1]
 [0 0 0 2 0 0]]
Memory utilised (bytes):  184
Type of the object <class 'numpy.ndarray'>

Converting Matrix A to the Compressed sparse row matrix representation using csr_matrix Class:

S = csr_matrix(A)
print("Sparse 'row' matrix: \n",S)
print("Memory utilised (bytes): ", sys.getsizeof(S))
print("Type of the object", type(S))

The output of print statements:

Sparse 'row' matrix:
(0, 0) 1
(1, 2) 2
(1, 5) 1
(2, 3) 2
Memory utilised (bytes): 56
Type of the object: <class 'scipy.sparse.csr.csc_matrix'>

Converting Matrix A to Compressed Sparse Column matrix representation using csc_matrix Class:

S = csc_matrix(A)
print("Sparse 'column' matrix: \n",S)
print("Memory utilised (bytes): ", sys.getsizeof(S))
print("Type of the object", type(S))

The output of print statements:

Sparse 'column' matrix:
(0, 0) 1
(1, 2) 2
(2, 3) 2
(1, 5) 1
Memory utilised (bytes): 56
Type of the object: <class 'scipy.sparse.csc.csc_matrix'>

As it can be seen the size of the compressed matrices is 56 bytes and the original matrix size is 184 bytes.

For a more detailed explanation and code examples please refer to this article: https://limitlessdatascience.wordpress.com/2020/11/26/sparse-matrix-in-machine-learning/

How to get local server host and port in Spring Boot?

IP Address

You can get network interfaces with NetworkInterface.getNetworkInterfaces(), then the IP addresses off the NetworkInterface objects returned with .getInetAddresses(), then the string representation of those addresses with .getHostAddress().

Port

If you make a @Configuration class which implements ApplicationListener<EmbeddedServletContainerInitializedEvent>, you can override onApplicationEvent to get the port number once it's set.

@Override
public void onApplicationEvent(EmbeddedServletContainerInitializedEvent event) {
    int port = event.getEmbeddedServletContainer().getPort();
}

Convert integer into its character equivalent, where 0 => a, 1 => b, etc

I don't like all the solutions that use magic numbers like 97 or 36.

const A = 'A'.charCodeAt(0);

let numberToCharacter = number => String.fromCharCode(A + number);

let characterToNumber = character => character.charCodeAt(0) - A;

this assumes uppercase letters and starts 'A' at 0.

TypeError: $.ajax(...) is not a function?

If you are using bootstrap html template remember to remove the link to jquery slim at the bottom of the template. I post this detail here as I cannot comment answers yet..

Unable to import path from django.urls

The reason you cannot import path is because it is new in Django 2.0 as is mentioned here: https://docs.djangoproject.com/en/2.0/ref/urls/#path.

On that page in the bottom right hand corner you can change the documentation version to the version that you have installed. If you do this you will see that there is no entry for path on the 1.11 docs.

How to find out the location of currently used MySQL configuration file in linux

The information you want can be found by running

mysql --help

or

mysqld --help --verbose

I tried this command on my machine:

mysql --help | grep "Default options" -A 1

And it printed out:

Default options are read from the following files in the given order:
/etc/my.cnf /usr/local/etc/my.cnf ~/.my.cnf

See if that works for you.

nodemon not found in npm

You have to simply installed it globally. npm install -g nodemon

How to hide/show more text within a certain length (like youtube)

HTML

<div>asdasdasdasd
    <br>asdasdasdasd
    <br>asdasdasdasd
    <br>asdasdasdasd
    <br>asdasdasdasd
    <br>asdasdasdasd
    <br>asdasdasdasd
    <br>asdasdasdasd
    <br>asdasdasdasd
    <br>asdasdasdasd
    <br>asdasdasdasd
    <br>asdasdasdasd
    <br>asdasdasdasd
    <br>asdasdasdasd
    <br>
</div>

<a id="more" href="#">Read more </a>
<a id="less" href="#">Read less </a>

CSS

<style type="text/css">
    div{
        width:100px;
        height:50px;
        display:block;
        border:1px solid red;
        padding:10px;
        overflow:hidden;
    }
</style>    

jQuery

<link rel="stylesheet" 
href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.9/themes/start/jquery-ui.css" 
type="text/css" media="all" />

<script type="text/javascript">
var h = $('div')[0].scrollHeight;


$('#more').click(function(e) {
   e.stopPropagation();
   $('div').animate({
      'height': h
   })
   $('#more').hide();
   $('#less').show();
});

$('#less').click(function(e) {

    $('#more').show();
    $('#less').hide();
});

$(document).click(function() {
    $('div').animate({
        'height': '50px'
    })
})
$(document).ready(function(){
     $('#less').hide();
})
</script>

How to read integer value from the standard input in Java

check this one:

import java.io.*;
public class UserInputInteger
{
        public static void main(String args[])throws IOException
        {
        InputStreamReader read = new InputStreamReader(System.in);
        BufferedReader in = new BufferedReader(read);
        int number;
                System.out.println("Enter the number");
                number = Integer.parseInt(in.readLine());
    }
}

Padding between ActionBar's home icon and title

I used AppBarLayout and custom ImageButton do to so.

<android.support.design.widget.AppBarLayout
    android:id="@+id/appbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:elevation="0dp"
    android:background="@android:color/transparent"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

   <RelativeLayout
       android:layout_width="match_parent"
       android:layout_height="match_parent">

       <ImageView
           android:layout_width="32dp"
           android:layout_height="32dp"
           android:src="@drawable/selector_back_button"
           android:layout_centerVertical="true"
           android:layout_marginLeft="8dp"
           android:id="@+id/back_button"/>

       <android.support.v7.widget.Toolbar
           android:id="@+id/toolbar"
           android:layout_width="match_parent"
           android:layout_height="?attr/actionBarSize"
           app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>
    </RelativeLayout>    
</android.support.design.widget.AppBarLayout>

My Java code:

findViewById(R.id.appbar).bringToFront();
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
final ActionBar ab = getSupportActionBar();
getSupportActionBar().setDisplayShowTitleEnabled(false);

How to check user is "logged in"?

if (User.Identity.IsAuthenticated)
{
    Page.Title = "Home page for " + User.Identity.Name;
}
else
{
    Page.Title = "Home page for guest user.";
}

Repeat table headers in print mode

Before you implement this solution it's important to know that Webkit currently doesn't do this.

Here is the relevant issue on the Chrome issue tracker: http://code.google.com/p/chromium/issues/detail?id=24826

And on the Webkit issue tracker: https://bugs.webkit.org/show_bug.cgi?id=17205

Star it on the Chrome issue tracker if you want to show that it is important to you (I did).

Uncaught SoapFault exception: [HTTP] Error Fetching http headers

Did you try adding

'trace'=>1,

to SoapClient creation parameters and then:

var_dump($client->__getLastRequest());
var_dump($client->__getLastResponse());

to see what is going on?

getResourceAsStream returns null

What worked for me is I placed the file under

src/main/java/myfile.log

and

InputStream is = getClass().getClassLoader().getResourceAsStream("myfile.log");
        
        if (is == null) {
            throw new FileNotFoundException("Log file not provided");
        }

Replacing a fragment with another fragment inside activity group

Use this code using v4

 ExampleFragment newFragment = new ExampleFragment();     
 FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();  
 // Replace whatever is in the fragment_container view with this fragment,  
 // and add the transaction to the back stack so the user can navigate back   
 transaction.replace(R.id.container, newFragment);
 transaction.addToBackStack(null);  
 // Commit the transaction   
 transaction.commit();

Regular expression for exact match of a string

In malfaux's answer '^' and '$' has been used to detect the beginning and the end of the text.
These are usually used to detect the beginning and the end of a line.
However this may be the correct way in this case.
But if you wish to match an exact word the more elegant way is to use '\b'. In this case following pattern will match the exact phrase'123456'.

/\b123456\b/

How can I run another application within a panel of my C# program?

If you want to run notepad inside your app you would probably be better of with a text editor component. There's obviously a basic text box that comes with WinForms, but I suspect more advanced components that offer Notepad functionality (or better) can be found on the interweb.

Compile to stand alone exe for C# app in Visual Studio 2010

You can get single file EXE after build the console application

your Application folder - > bin folder -> there will have lot of files there is need 2 files must and other referenced dlls

1. IMG_PDF_CONVERSION [this is my application name, take your application name]
2. IMG_PDF_CONVERSION.exe [this is supporting configure file]
3. your refered dll's

then you can move that 3(exe, configure file, refered dll's) dll to any folder that's it

if you click on 1st IMG_PDF_CONVERSION it will execute the application cool way

any calcification please ask your queries.

Printing leading 0's in C

You place a zero before the minimum field width:

printf("%05d", zipcode);

Convert NSDate to NSString

swift 4 answer

static let dateformat: String = "yyyy-MM-dd'T'HH:mm:ss"
public static func stringTodate(strDate : String) -> Date
{

    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = dateformat
    let date = dateFormatter.date(from: strDate)
    return date!
}
public static func dateToString(inputdate : Date) -> String
{

    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = dateformat
    return formatter.string(from: inputdate)

}

How to copy data from one HDFS to another HDFS?

distcp command use for copying from one cluster to another cluster in parallel. You have to set the path for namenode of src and path for namenode of dst, internally it use mapper.

Example:

$ hadoop distcp <src> <dst>

there few options you can set for distcp

-m for no. of mapper for copying data this will increase speed of copying.

-atomic for auto commit the data.

-update will only update data that is in old version.

There are generic command for copying files in hadoop are -cp and -put but they are use only when the data volume is less.

How to check for Is not Null And Is not Empty string in SQL server?

WHERE NULLIF(your_column, '') IS NOT NULL

Nowadays (4.5 years on), to make it easier for a human to read, I would just use

WHERE your_column <> ''

While there is a temptation to make the null check explicit...

WHERE your_column <> '' 
      AND your_column IS NOT NULL

...as @Martin Smith demonstrates in the accepted answer, it doesn't really add anything (and I personally shun SQL nulls entirely nowadays, so it wouldn't apply to me anyway!).

simple vba code gives me run time error 91 object variable or with block not set

Also you are trying to set value2 using Set keyword, which is not required. You can directly use rng.value2 = 1

below test code for ref.

Sub test()
    Dim rng As Range
    Set rng = Range("A1")
    rng.Value2 = 1
End Sub

Capitalize words in string

If you're using lodash in your JavaScript application, You can use _.capitalize:

_x000D_
_x000D_
console.log( _.capitalize('ÿöur striñg') );_x000D_
 
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js"></script>
_x000D_
_x000D_
_x000D_

creating Hashmap from a JSON String

public Map<String, String> parseJSON(JSONObject json, Map<String, String> dataFields) throws JSONException {
        Iterator<String> keys = json.keys();
        while (keys.hasNext()) {
            String key = keys.next();
            String val = null;
            try {
                JSONObject value = json.getJSONObject(key);
                parseJSON(value, dataFields);
            } catch (Exception e) {
                if (json.isNull(key)) {
                    val = "";
                } else {
                    try {
                        val = json.getString(key);
                    } catch (Exception ex) {
                        System.out.println(ex.getMessage());
                    }
                }
            }

            if (val != null) {
                dataFields.put(key, val);
            }
        }
        return dataFields;
    }

How to redirect to previous page in Ruby On Rails?

request.referer is set by Rack and is set as follows:

def referer
  @env['HTTP_REFERER'] || '/'
end

Just do a redirect_to request.referer and it will always redirect to the true referring page, or the root_path ('/'). This is essential when passing tests that fail in cases of direct-nav to a particular page in which the controller throws a redirect_to :back

How to make HTML Text unselectable

I altered the jQuery plugin posted above so it would work on live elements.

(function ($) {
$.fn.disableSelection = function () {
    return this.each(function () {
        if (typeof this.onselectstart != 'undefined') {
            this.onselectstart = function() { return false; };
        } else if (typeof this.style.MozUserSelect != 'undefined') {
            this.style.MozUserSelect = 'none';
        } else {
            this.onmousedown = function() { return false; };
        }
    });
};
})(jQuery);

Then you could so something like:

$(document).ready(function() {
    $('label').disableSelection();

    // Or to make everything unselectable
    $('*').disableSelection();
});

How to use GNU Make on Windows?

Although this question is old, it is still asked by many who use MSYS2.

I started to use it this year to replace CygWin, and I'm getting pretty satisfied.

To install make, open the MSYS2 shell and type the following commands:

# Update the package database and core system packages
pacman -Syu
# Close shell and open again if needed

# Update again
pacman -Su

# Install make
pacman -S make

# Test it (show version)
make -v

Visual Studio Code compile on save

Step 1

In your tsconfig.json

"compileOnSave": true, // change it to true and save the application

if problem is still there then apply step-2

Step 2

Restart your editor

if still problem not resolved then apply step-3

Step 3

Change any route, revert it back and save the application. It'll start compiling. i.e.

const routes: Routes = [
  {
    path: '', // i.e. remove , (comma) and then insert it and save, it'll start compiling
    component: MyComponent
  }
]

Count all occurrences of a string in lots of files with grep

Something different than all the previous answers:

perl -lne '$count++ for m/<pattern>/g;END{print $count}' *

What is the function of FormulaR1C1?

FormulaR1C1 has the same behavior as Formula, only using R1C1 style annotation, instead of A1 annotation. In A1 annotation you would use:

Worksheets("Sheet1").Range("A5").Formula = "=A4+A10"

In R1C1 you would use:

Worksheets("Sheet1").Range("A5").FormulaR1C1 = "=R4C1+R10C1"

It doesn't act upon row 1 column 1, it acts upon the targeted cell or range. Column 1 is the same as column A, so R4C1 is the same as A4, R5C2 is B5, and so forth.

The command does not change names, the targeted cell changes. For your R2C3 (also known as C2) example :

Worksheets("Sheet1").Range("C2").FormulaR1C1 = "=your formula here"

Get age from Birthdate

Try this function...

function calculate_age(birth_month,birth_day,birth_year)
{
    today_date = new Date();
    today_year = today_date.getFullYear();
    today_month = today_date.getMonth();
    today_day = today_date.getDate();
    age = today_year - birth_year;

    if ( today_month < (birth_month - 1))
    {
        age--;
    }
    if (((birth_month - 1) == today_month) && (today_day < birth_day))
    {
        age--;
    }
    return age;
}

OR

function getAge(dateString) 
{
    var today = new Date();
    var birthDate = new Date(dateString);
    var age = today.getFullYear() - birthDate.getFullYear();
    var m = today.getMonth() - birthDate.getMonth();
    if (m < 0 || (m === 0 && today.getDate() < birthDate.getDate())) 
    {
        age--;
    }
    return age;
}

See Demo.

Java associative-array

Look at the Map interface, and at the concrete class HashMap.

To create a Map:

Map<String, String> assoc = new HashMap<String, String>();

To add a key-value pair:

assoc.put("name", "demo");

To retrieve the value associated with a key:

assoc.get("name")

And sure, you may create an array of Maps, as it seems to be what you want:

Map<String, String>[] assoc = ...

Java: Converting String to and from ByteBuffer and associated problems

Unless things have changed, you're better off with

public static ByteBuffer str_to_bb(String msg, Charset charset){
    return ByteBuffer.wrap(msg.getBytes(charset));
}

public static String bb_to_str(ByteBuffer buffer, Charset charset){
    byte[] bytes;
    if(buffer.hasArray()) {
        bytes = buffer.array();
    } else {
        bytes = new byte[buffer.remaining()];
        buffer.get(bytes);
    }
    return new String(bytes, charset);
}

Usually buffer.hasArray() will be either always true or always false depending on your use case. In practice, unless you really want it to work under any circumstances, it's safe to optimize away the branch you don't need.

Laravel 4: how to "order by" using Eloquent ORM

This is how I would go about it.

$posts = $this->post->orderBy('id', 'DESC')->get();

Delete all but the most recent X files in bash

With zsh

Assuming you don't care about present directories and you will not have more than 999 files (choose a bigger number if you want, or create a while loop).

[ 6 -le `ls *(.)|wc -l` ] && rm *(.om[6,999])

In *(.om[6,999]), the . means files, the o means sort order up, the m means by date of modification (put a for access time or c for inode change), the [6,999] chooses a range of file, so doesn't rm the 5 first.

Combine two tables for one output

In your expected output, you've got the second last row sum incorrect, it should be 40 according to the data in your tables, but here is the query:

Select  ChargeNum, CategoryId, Sum(Hours)
From    (
    Select  ChargeNum, CategoryId, Hours
    From    KnownHours
    Union
    Select  ChargeNum, 'Unknown' As CategoryId, Hours
    From    UnknownHours
) As a
Group By ChargeNum, CategoryId
Order By ChargeNum, CategoryId

And here is the output:

ChargeNum  CategoryId 
---------- ---------- ----------------------
111111     1          40
111111     2          50
111111     Unknown    70
222222     1          40
222222     Unknown    25.5

iTunes Connect Screenshots Sizes for all iOS (iPhone/iPad/Apple Watch) devices

 1)iPhone X screenshot support in iTunes Connect.October 27, 2017.

 2)You can now upload screenshots for iPhone X. 
  You’ll see a new tab for 5.8-inch displays under Screenshots and App Previews on your iOS app  version information page.

 3)Note that iPhone X screenshots are optional and cannot be used for smaller devices sizes. 
  5.5-inchdisplay screenshots are still required for all apps that run on iPhone.

 4)iPhone X Screenshot Resolutions
  1125 by 2436 (Portrait)
  2436 by 1125 (Landscape)

Docker command can't connect to Docker daemon

Add the user to the docker group

  • Add the docker group if it doesn't already exist:

    sudo groupadd docker

  • Add the connected user "${USER}" to the docker group:

    sudo gpasswd -a ${USER} docker

  • Restart the Docker daemon:

    sudo service docker restart

  • Either do a newgrp docker or log out/in to activate the changes to groups.

Does it matter what extension is used for SQLite database files?

If you have settled on a particular set of tools to access / modify your databases, I would go with whatever extension they expect you to use. This will avoid needless friction when doing development tasks.

For instance, SQLiteStudio v3.1.1 defaults to looking for files with the following extensions:

enter image description here

(db|sdb|sqlite|db3|s3db|sqlite3|sl3|db2|s2db|sqlite2|sl2)

If necessary for deployment your installation mechanism could rename the file if obscuring the file type seems useful to you (as some other answers have suggested). Filename requirements for development and deployment can be different.

syntax error when using command line in python

Running from the command line means running from the terminal or DOS shell. You are running it from Python itself.

if (boolean condition) in Java

if (turnedOn) {
    //do stuff when the condition is false or true?
}
else {
    //do else of if
}

It can be written like:

if (turnedOn == true) {
        //do stuff when the condition is false or true?
    }
else { // turnedOn == false or !turnedOn
        //do else of if
}

So if your turnedOn variable is true, if will be called, if is assigned to false, else will be called. boolean values are implicitly assigned to false if you won't assign them explicitly e.q. turnedOn = true

How to access the GET parameters after "?" in Express?

So, after checking out the express reference, I found that req.query.color would return me the value I'm looking for.

req.params refers to items with a ':' in the URL and req.query refers to items associated with the '?'

Example:

GET /something?color1=red&color2=blue

Then in express, the handler:

app.get('/something', (req, res) => {
    req.query.color1 === 'red'  // true
    req.query.color2 === 'blue' // true
})

How to exit a 'git status' list in a terminal?

You can disable pager for commands that don't recognize --no-pager flag.

git config --global pager.<command> false

I disable for log aliases and set specific quantity to return.

git config --global pager.log false

Find empty or NaN entry in Pandas Dataframe

Check if the columns contain Nan using .isnull() and check for empty strings using .eq(''), then join the two together using the bitwise OR operator |.

Sum along axis 0 to find columns with missing data, then sum along axis 1 to the index locations for rows with missing data.

missing_cols, missing_rows = (
    (df2.isnull().sum(x) | df2.eq('').sum(x))
    .loc[lambda x: x.gt(0)].index
    for x in (0, 1)
)

>>> df2.loc[missing_rows, missing_cols]
         A2       A3
2            1.10035
5 -0.508501         
6       NaN      NaN
7       NaN      NaN

Pass Array Parameter in SqlCommand

Here is a minor variant of Brian's answer that someone else may find useful. Takes a List of keys and drops it into the parameter list.

//keyList is a List<string>
System.Data.SqlClient.SqlCommand command = new System.Data.SqlClient.SqlCommand();
string sql = "SELECT fieldList FROM dbo.tableName WHERE keyField in (";
int i = 1;
foreach (string key in keyList) {
    sql = sql + "@key" + i + ",";
    command.Parameters.AddWithValue("@key" + i, key);
    i++;
}
sql = sql.TrimEnd(',') + ")";

How do I keep jQuery UI Accordion collapsed by default?

Add the active: false option (documentation)..

$("#accordion").accordion({ header: "h3", collapsible: true, active: false });

How to fix ReferenceError: primordials is not defined in node

Gulp is making issue with Nodejs version 11 and above. Uninstall your current node version and reinstall the v10.15.1 here is link for that version. This helps me and it will solve your problem too.

https://nodejs.org/download/release/v10.15.1/

How to abort a Task like aborting a Thread (Thread.Abort method)?

While it's possible to abort a thread, in practice it's almost always a very bad idea to do so. Aborthing a thread means the thread is not given a chance to clean up after itself, leaving resources undeleted, and things in unknown states.

In practice, if you abort a thread, you should only do so in conjunction with killing the process. Sadly, all too many people think ThreadAbort is a viable way of stopping something and continuing on, it's not.

Since Tasks run as threads, you can call ThreadAbort on them, but as with generic threads you almost never want to do this, except as a last resort.

How do I make a Windows batch script completely silent?

To suppress output, use redirection to NUL.

There are two kinds of output that console commands use:

  • standard output, or stdout,

  • standard error, or stderr.

Of the two, stdout is used more often, both by internal commands, like copy, and by console utilities, or external commands, like find and others, as well as by third-party console programs.

>NUL suppresses the standard output and works fine e.g. for suppressing the 1 file(s) copied. message of the copy command. An alternative syntax is 1>NUL. So,

COPY file1 file2 >NUL

or

COPY file1 file2 1>NUL

or

>NUL COPY file1 file2

or

1>NUL COPY file1 file2

suppresses all of COPY's standard output.

To suppress error messages, which are typically printed to stderr, use 2>NUL instead. So, to suppress a File Not Found message that DEL prints when, well, the specified file is not found, just add 2>NUL either at the beginning or at the end of the command line:

DEL file 2>NUL

or

2>NUL DEL file

Although sometimes it may be a better idea to actually verify whether the file exists before trying to delete it, like you are doing in your own solution. Note, however, that you don't need to delete the files one by one, using a loop. You can use a single command to delete the lot:

IF EXIST "%scriptDirectory%*.noext" DEL "%scriptDirectory%*.noext"

Using jQuery to center a DIV on the screen

I would use the jQuery UI position function.

See working demo.

<div id="test" style="position:absolute;background-color:blue;color:white">
    test div to center in window
</div>

If i have a div with id "test" to center then the following script would center the div in the window on document ready. (the default values for "my" and "at" in the position options are "center")

<script type="text/javascript">
$(function(){
  $("#test").position({
     of: $(window)
  });
};
</script>

Mailto on submit button

Just include "a" tag in "button" tag.

<button><a href="mailto:..."></a></button>

Python error when trying to access list by index - "List indices must be integers, not str"

A list is a chain of spaces that can be indexed by (0, 1, 2 .... etc). So if players was a list, players[0] or players[1] would have worked. If players is a dictionary, players["name"] would have worked.

How can I load Partial view inside the view?

if you want to populate contents of your partial view inside your view you can use

@Html.Partial("PartialViewName")

or

{@Html.RenderPartial("PartialViewName");}

if you want to make server request and process the data and then return partial view to you main view filled with that data you can use

...
    @Html.Action("Load", "Home")
...

public PartialViewResult Load()
{
    return PartialView("_LoadView");
}

if you want user to click on the link and then populate the data of partial view you can use:

@Ajax.ActionLink(
    "Click Here to Load the Partial View", 
    "ActionName", 
    "ControlerName",
    null, 
    new AjaxOptions { UpdateTargetId = "toUpdate" }
)

Pad a string with leading zeros so it's 3 characters long in SQL Server 2008

Wrote this because I had requirements for up to a specific length (9). Pads the left with the @pattern ONLY when the input needs padding. Should always return length defined in @pattern.

declare @charInput as char(50) = 'input'

--always handle NULL :)
set @charInput = isnull(@charInput,'')

declare @actualLength as int = len(@charInput)

declare @pattern as char(50) = '123456789'
declare @prefLength as int = len(@pattern)

if @prefLength > @actualLength
    select Left(Left(@pattern, @prefLength-@actualLength) + @charInput, @prefLength)
else
    select @charInput

Returns 1234input

Reading file using relative path in python project

This worked for me.

with open('data/test.csv') as f:

 

Can Powershell Run Commands in Parallel?

If you're using latest cross platform powershell (which you should btw) https://github.com/powershell/powershell#get-powershell, you can add single & to run parallel scripts. (Use ; to run sequentially)

In my case I needed to run 2 npm scripts in parallel: npm run hotReload & npm run dev


You can also setup npm to use powershell for its scripts (by default it uses cmd on windows).

Run from project root folder: npm config set script-shell pwsh --userconfig ./.npmrc and then use single npm script command: npm run start

"start":"npm run hotReload & npm run dev"

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

In case your using testing.M and associated setup/teardown; -v is valid here as well.

package g 

import (
    "os"
    "fmt"
    "testing"
)

func TestSomething(t *testing.T) {
    t.Skip("later")
}

func setup() {
    fmt.Println("setting up")
}

func teardown() {
    fmt.Println("tearing down")
}

func TestMain(m *testing.M) {
    setup()
    result := m.Run()
    teardown()
    os.Exit(result)
}
$ go test -v g_test.go 
setting up
=== RUN   TestSomething
    g_test.go:10: later
--- SKIP: TestSomething (0.00s)
PASS
tearing down
ok      command-line-arguments  0.002s

Salt and hash a password in Python

I don' want to resurrect an old thread, but... anyone who wants to use a modern up to date secure solution, use argon2.

https://pypi.python.org/pypi/argon2_cffi

It won the the password hashing competition. ( https://password-hashing.net/ ) It is easier to use than bcrypt, and it is more secure than bcrypt.

Disable/Enable Submit Button until all forms have been filled

I just posted this on Disable Submit button until Input fields filled in. Works for me.

Use the form onsubmit. Nice and clean. You don't have to worry about the change and keypress events firing. Don't have to worry about keyup and focus issues.

http://www.w3schools.com/jsref/event_form_onsubmit.asp

<form action="formpost.php" method="POST" onsubmit="return validateCreditCardForm()">
   ...
</form>

function validateCreditCardForm(){
    var result = false;
    if (($('#billing-cc-exp').val().length > 0) &&
        ($('#billing-cvv').val().length  > 0) &&
        ($('#billing-cc-number').val().length > 0)) {
            result = true;
    }
    return result;
}

Change the encoding of a file in Visual Studio Code

Apart from the settings explained in the answer by @DarkNeuron:

"files.encoding": "any encoding"

you can also specify settings for a specific language like so:

"[language id]": {
  "files.encoding": "any encoding"
}

For example, I use this when I need to edit PowerShell files previously created with ISE (which are created in ANSI format):

"[powershell]": {
    "files.encoding": "windows1252"
}

You can get a list of identifiers of well-known languages here.

Python variables as keys to dict

Well this is a bit, umm ... non-Pythonic ... ugly ... hackish ...

Here's a snippet of code assuming you want to create a dictionary of all the local variables you create after a specific checkpoint is taken:

checkpoint = [ 'checkpoint' ] + locals().keys()[:]
## Various local assigments here ...
var_keys_since_checkpoint = set(locals().keys()) - set(checkpoint)
new_vars = dict()
for each in var_keys_since_checkpoint:
   new_vars[each] = locals()[each]

Note that we explicitly add the 'checkpoint' key into our capture of the locals().keys() I'm also explicitly taking a slice of that though it shouldn't be necessary in this case since the reference has to be flattened to add it to the [ 'checkpoint' ] list. However, if you were using a variant of this code and tried to shortcut out the ['checkpoint'] + portion (because that key was already inlocals(), for example) ... then, without the [:] slice you could end up with a reference to thelocals().keys()` whose values would change as you added variables.

Offhand I can't think of a way to call something like new_vars.update() with a list of keys to be added/updated. So thefor loop is most portable. I suppose a dictionary comprehension could be used in more recent versions of Python. However that woudl seem to be nothing more than a round of code golf.

How can I delete using INNER JOIN with SQL Server?

In SQL Server Management Studio I can easily create a SELECT query:

SELECT Contact.Naam_Contactpersoon, Bedrijf.BedrijfsNaam, Bedrijf.Adres, Bedrijf.Postcode
FROM Contact
INNER JOIN Bedrijf ON Bedrijf.IDBedrijf = Contact.IDbedrijf

I can execute it, and all my contacts are shown.

Now change the SELECT to a DELETE:

DELETE Contact
FROM Contact
INNER JOIN Bedrijf ON Bedrijf.IDBedrijf = Contact.IDbedrijf

All the records you saw in the SELECT statement will be removed.

You may even create a more difficult inner join with the same procedure, for example:

DELETE FROM Contact
INNER JOIN Bedrijf ON Bedrijf.IDBedrijf = Contact.IDbedrijf
INNER JOIN LoginBedrijf ON Bedrijf.IDLoginBedrijf = LoginBedrijf.IDLoginBedrijf

Service located in another namespace

To access services in two different namespaces you can use url like this:

HTTP://<your-service-name>.<namespace-with-that-service>.svc.cluster.local

To list out all your namespaces you can use:

kubectl get namespace

And for service in that namespace you can simply use:

kubectl get services -n <namespace-name>

this will help you.

Setting a PHP $_SESSION['var'] using jQuery

Similar to Luke's answer, but with GET.

Place this php-code in a php-page, ex. getpage.php:

<?php
$_SESSION['size'] = $_GET['size'];
?>

Then call it with a jQuery script like this:

$.get( "/getpage.php?size=1");

Agree with Federico. In some cases you may run into problems using POST, although not sure if it can be browser related.

How to get the currently logged in user's user id in Django?

You can access Current logged in user by using the following code:

request.user.id

How do I update Anaconda?

root is the old (pre-conda 4.4) name for the main environment; after conda 4.4, it was renamed to be base. source

What 95% of people actually want

In most cases what you want to do when you say that you want to update Anaconda is to execute the command:

conda update --all

(But this should be preceeded by conda update -n base conda so you have the latest conda version installed)

This will update all packages in the current environment to the latest version -- with the small print being that it may use an older version of some packages in order to satisfy dependency constraints (often this won't be necessary and when it is necessary the package plan solver will do its best to minimize the impact).

This needs to be executed from the command line, and the best way to get there is from Anaconda Navigator, then the "Environments" tab, then click on the triangle beside the base environment, selecting "Open Terminal":

Open terminal from Navigator

This operation will only update the one selected environment (in this case, the base environment). If you have other environments you'd like to update you can repeat the process above, but first click on the environment. When it is selected there is a triangular marker on the right (see image above, step 3). Or from the command line you can provide the environment name (-n envname) or path (-p /path/to/env), for example to update your dspyr environment from the screenshot above:

conda update -n dspyr --all

Update individual packages

If you are only interested in updating an individual package then simply click on the blue arrow or blue version number in Navigator, e.g. for astroid or astropy in the screenshot above, and this will tag those packages for an upgrade. When you are done you need to click the "Apply" button:

Apply to update individual packages

Or from the command line:

conda update astroid astropy

Updating just the packages in the standard Anaconda Distribution

If you don't care about package versions and just want "the latest set of all packages in the standard Anaconda Distribution, so long as they work together", then you should take a look at this gist.

Why updating the Anaconda package is almost always a bad idea

In most cases updating the Anaconda package in the package list will have a surprising result: you may actually downgrade many packages (in fact, this is likely if it indicates the version as custom). The gist above provides details.

Leverage conda environments

Your base environment is probably not a good place to try and manage an exact set of packages: it is going to be a dynamic working space with new packages installed and packages randomly updated. If you need an exact set of packages then create a conda environment to hold them. Thanks to the conda package cache and the way file linking is used doing this is typically i) fast and ii) consumes very little additional disk space. E.g.

conda create -n myspecialenv -c bioconda -c conda-forge python=3.5 pandas beautifulsoup seaborn nltk

The conda documentation has more details and examples.

pip, PyPI, and setuptools?

None of this is going to help with updating packages that have been installed from PyPI via pip or any packages installed using python setup.py install. conda list will give you some hints about the pip-based Python packages you have in an environment, but it won't do anything special to update them.

Commercial use of Anaconda or Anaconda Enterprise

It is pretty much exactly the same story, with the exception that you may not be able to update the base environment if it was installed by someone else (say to /opt/anaconda/latest). If you're not able to update the environments you are using you should be able to clone and then update:

conda create -n myenv --clone base
conda update -n myenv --all

What is the difference between aggregation, composition and dependency?

Aggregation - separable part to whole. The part has a identity of its own, separate from what it is part of. You could pick that part and move it to another object. (real world examples: wheel -> car, bloodcell -> body)

Composition - non-separable part of the whole. You cannot move the part to another object. more like a property. (real world examples: curve -> road, personality -> person, max_speed -> car, property of object -> object )

Note that a relation that is an aggregate in one design can be a composition in another. Its all about how the relation is to be used in that specific design.

dependency - sensitive to change. (amount of rain -> weather, headposition -> bodyposition)

Note: "Bloodcell" -> Blood" could be "Composition" as Blood Cells can not exist without the entity called Blood. "Blood" -> Body" could be "Aggregation" as Blood can exist without the entity called Body.

How to resolve "git did not exit cleanly (exit code 128)" error on TortoiseGit?

An quick solution would be to create a new local directory for example c:\git_2014, In this directory rightklick and choose Git Clone

XML Schema Validation : Cannot find the declaration of element

Thanks to everyone above, but this is now fixed. For the benefit of others the most significant error was in aligning the three namespaces as suggested by Ian.

For completeness, here is the corrected XML and XSD

Here is the XML, with the typos corrected (sorry for any confusion caused by tardiness)

<?xml version="1.0" encoding="UTF-8"?>

<Root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xmlns="urn:Test.Namespace"  
      xsi:schemaLocation="urn:Test.Namespace Test1.xsd">
    <element1 id="001">
        <element2 id="001.1">
            <element3 id="001.1" />
        </element2>
    </element1>
</Root>

and, here is the Schema

<?xml version="1.0"?>

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
            targetNamespace="urn:Test.Namespace"
            xmlns="urn:Test.Namespace"
            elementFormDefault="qualified">
    <xsd:element name="Root">
        <xsd:complexType>
            <xsd:sequence>
                <xsd:element name="element1" maxOccurs="unbounded" type="element1Type"/>
            </xsd:sequence>
        </xsd:complexType>
    </xsd:element>
       
    <xsd:complexType name="element1Type">
        <xsd:sequence>
            <xsd:element name="element2" maxOccurs="unbounded" type="element2Type"/>
        </xsd:sequence>
        <xsd:attribute name="id" type="xsd:string"/>
    </xsd:complexType>
       
    <xsd:complexType name="element2Type">
        <xsd:sequence>
            <xsd:element name="element3" type="element3Type"/>
        </xsd:sequence>
        <xsd:attribute name="id" type="xsd:string"/>
    </xsd:complexType>

    <xsd:complexType name="element3Type">
        <xsd:attribute name="id" type="xsd:string"/>
    </xsd:complexType>        
</xsd:schema>

Thanks again to everyone, I hope this is of use to somebody else in the future.

Excel formula is only showing the formula rather than the value within the cell in Office 2010

Add an = at the beginning. That makes it a function rather than an entry.

Can a relative sitemap url be used in a robots.txt?

Google crawlers are not smart enough, they can't crawl relative URLs, that's why it's always recommended to use absolute URL's for better crawlability and indexability.

Therefore, you can not use this variation

> sitemap: /sitemap.xml

Recommended syntax is

Sitemap: https://www.yourdomain.com/sitemap.xml

Note:

  • Don't forgot to capitalise the first letter in "sitemap"
  • Don't forgot to put space after "Sitemap:"

How to do error logging in CodeIgniter (PHP)

More oin regards to question part 4 How do you e-mail that error to an email address? The error_log function has email destination too. http://php.net/manual/en/function.error-log.php

Agha, here I found an example that shows a usage. Send errors message via email using error_log()

error_log($this->_errorMsg, 1, ADMIN_MAIL, "Content-Type: text/html; charset=utf8\r\nFrom: ".MAIL_ERR_FROM."\r\nTo: ".ADMIN_MAIL);

What are Maven goals and phases and what is their difference?

There are following three built-in build lifecycles:

  • default
  • clean
  • site

Lifecycle default -> [validate, initialize, generate-sources, process-sources, generate-resources, process-resources, compile, process-classes, generate-test-sources, process-test-sources, generate-test-resources, process-test-resources, test-compile, process-test-classes, test, prepare-package, package, pre-integration-test, integration-test, post-integration-test, verify, install, deploy]

Lifecycle clean -> [pre-clean, clean, post-clean]

Lifecycle site -> [pre-site, site, post-site, site-deploy]

The flow is sequential, for example, for default lifecycle, it starts with validate, then initialize and so on...

You can check the lifecycle by enabling debug mode of mvn i.e., mvn -X <your_goal>

popup form using html/javascript/css

Here is a resource you can edit and use Download Source Code or see live demo here http://purpledesign.in/blog/pop-out-a-form-using-jquery-and-javascript/

Add a Button or link to your page like this

<p><a href="#inline">click to open</a></p>

“#inline” here should be the “id” of the that will contain the form.

<div id="inline">
 <h2>Send us a Message</h2>
 <form id="contact" name="contact" action="#" method="post">
 <label for="email">Your E-mail</label>
 <input type="email" id="email" name="email" class="txt">
 <br>
 <label for="msg">Enter a Message</label>
 <textarea id="msg" name="msg" class="txtarea"></textarea>
<button id="send">Send E-mail</button>
 </form>
</div>

Include these script to listen of the event of click. If you have an action defined in your form you can use “preventDefault()” method

<script type="text/javascript">
 $(document).ready(function() {
$(".modalbox").fancybox();
$("#contact").submit(function() { return false; });
$("#send").on("click", function(){
var emailval = $("#email").val();
var msgval = $("#msg").val();
var msglen = msgval.length;
var mailvalid = validateEmail(emailval);
if(mailvalid == false) {
$("#email").addClass("error");
}
else if(mailvalid == true){
 $("#email").removeClass("error");
 }

 if(msglen < 4) {
 $("#msg").addClass("error");
 }
 else if(msglen >= 4){
 $("#msg").removeClass("error");
 }

 if(mailvalid == true && msglen >= 4) {
 // if both validate we attempt to send the e-mail
 // first we hide the submit btn so the user doesnt click twice
 $("#send").replaceWith("<em>sending...</em>");
 //This will post it to the php page
 $.ajax({
 type: 'POST',
 url: 'sendmessage.php',
 data: $("#contact").serialize(),
 success: function(data) {
 if(data == "true") {
 $("#contact").fadeOut("fast", function(){
//Display a message on successful posting for 1 sec
 $(this).before("<p><strong>Success! Your feedback has been sent, thanks :)</strong></p>");
 setTimeout("$.fancybox.close()", 1000);
 });
 }
 }
 });
 }
 });
 });
</script>

You can add anything you want to do in your PHP file.

android activity has leaked window com.android.internal.policy.impl.phonewindow$decorview Issue

 @Override
    protected void onPostExecute(final Boolean success) {
        mProgressDialog.dismiss();
        mProgressDialog = null;

setting the value null works for me

MySQL Where DateTime is greater than today

I guess you looking for CURDATE() or NOW() .

  SELECT name, datum 
  FROM tasks 
  WHERE datum >= CURDATE()

LooK the rsult of NOW and CURDATE

   NOW()                    CURDATE()        
   2008-11-11 12:45:34      2008-11-11       

How to input a path with a white space?

If the path in Ubuntu is "/home/ec2-user/Name of Directory", then do this:

1) Java's build.properties file:

build_path='/home/ec2-user/Name\\ of\\ Directory'

Where ~/ is equal to /home/ec2-user

2) Jenkinsfile:

build_path=buildprops['build_path']
echo "Build path= ${build_path}"
sh "cd ${build_path}"

Read from file or stdin

You can just read from stdin unless the user supply a filename ?

If not, treat the special "filename" - as meaning "read from stdin". The user would have to start the program like cat file | myprogram - if he wants to pipe data to it, and myprogam file if he wants it to read from a file.

int main(int argc,char *argv[] ) {
  FILE *input;
  if(argc != 2) {
     usage();
     return 1;
   }
   if(!strcmp(argv[1],"-")) {
     input = stdin;
    } else {
      input = fopen(argv[1],"rb");
      //check for errors
    }

If you're on *nix, you can check whether stdin is a fifo:

 struct stat st_info;
 if(fstat(0,&st_info) != 0)
   //error
  }
  if(S_ISFIFO(st_info.st_mode)) {
     //stdin is a pipe
  }

Though that won't handle the user doing myprogram <file

You can also check if stdin is a terminal/console

if(isatty(0)) {
  //stdin is a terminal
}

Run AVD Emulator without Android Studio

For Windows

In case anyone looking for shortcut / batch script - Gist - Download batch file.

@echo off
IF [%1]==[] (GOTO ExitWithPrompt)
set i=1
FOR /F "delims=" %%i IN ('emulator -list-avds') DO (
    set /A i=i+1
    set em=%%i
    if %i% == %1 (
        echo Starting %em%
        emulator -avd %em%
        EXIT /B 0
    )
)
GOTO :Exit
:ExitWithPrompt
emulator -list-avds
echo Please enter the emulator number to start

:Exit
EXIT /B 0

Usage

D:\>start-emulator
Nexus_5_API_26
Please enter the emulator number to start

D:\>start-emulator 1
Starting Nexus_5_API_26
HAX is working and emulator runs in fast virt mode.

How to terminate process from Python using pid?

Using the awesome psutil library it's pretty simple:

p = psutil.Process(pid)
p.terminate()  #or p.kill()

If you don't want to install a new library, you can use the os module:

import os
import signal

os.kill(pid, signal.SIGTERM) #or signal.SIGKILL 

See also the os.kill documentation.


If you are interested in starting the command python StripCore.py if it is not running, and killing it otherwise, you can use psutil to do this reliably.

Something like:

import psutil
from subprocess import Popen

for process in psutil.process_iter():
    if process.cmdline() == ['python', 'StripCore.py']:
        print('Process found. Terminating it.')
        process.terminate()
        break
else:
    print('Process not found: starting it.')
    Popen(['python', 'StripCore.py'])

Sample run:

$python test_strip.py   #test_strip.py contains the code above
Process not found: starting it.
$python test_strip.py 
Process found. Terminating it.
$python test_strip.py 
Process not found: starting it.
$killall python
$python test_strip.py 
Process not found: starting it.
$python test_strip.py 
Process found. Terminating it.
$python test_strip.py 
Process not found: starting it.

Note: In previous psutil versions cmdline was an attribute instead of a method.

Git on Bitbucket: Always asked for password, even after uploading my public SSH key

The following assumes command-line access via iTerm / Terminal to bitbucket.

For MacOS Sierra 10.12.5, my system manifested an equivalent problem - asking for my SSH passphrase on each connection to bitbucket.

The issue has to do with OpenSSH updates in macOS 10.12.2, which are described here in Technical Note TN2449.

You very well might want to tailor your solution, but the following will work when added to your ~/.ssh/config file:

Host *
    UseKeychain yes

For more information on ssh configs, take a look at the man pages for ssh_config:

% man ssh_config

One other thing: there is a good write-up on superuser here that discusses this problem and various solutions depending on your needs and setup.

How do you scroll up/down on the console of a Linux VM

Press the Shift key when scrolling the mouse up/down works for me when loggin in Ubuntu using Terminal ssh in Yosemite.

Calling Java from Python

I'm just beginning to use JPype 0.5.4.2 (july 2011) and it looks like it's working nicely...
I'm on Xubuntu 10.04

How to keep the header static, always on top while scrolling?

here is one with css + jquery (javascript) solution.

here is demo link Demo

//html

<div id="uberbar">
    <a href="#top">Top of Page</a>
    <a href="#bottom">Bottom of Page</a>

</div>

//css 

#uberbar    { 
    border-bottom:1px solid #eb7429; 
    background:#fc9453; 
    padding:10px 20px; 
    position:fixed; 
    top:0; 
    left:0; 
    z-index:2000; 
    width:100%;
}

//jquery

$(document).ready(function() {
    (function() {
        //settings
        var fadeSpeed = 200, fadeTo = 0.5, topDistance = 30;
        var topbarME = function() { $('#uberbar').fadeTo(fadeSpeed,1); }, topbarML = function() { $('#uberbar').fadeTo(fadeSpeed,fadeTo); };
        var inside = false;
        //do
        $(window).scroll(function() {
            position = $(window).scrollTop();
            if(position > topDistance && !inside) {
                //add events
                topbarML();
                $('#uberbar').bind('mouseenter',topbarME);
                $('#uberbar').bind('mouseleave',topbarML);
                inside = true;
            }
            else if (position < topDistance){
                topbarME();
                $('#uberbar').unbind('mouseenter',topbarME);
                $('#uberbar').unbind('mouseleave',topbarML);
                inside = false;
            }
        });
    })();
});

How can I backup a Docker-container with its data-volumes?

I have created a tool to orchestrate and launch backup of data and mysql containers, simply called docker-backup. There is even a ready-to-use image on the docker hub.

It's mainly written in Bash as it is mainly orchestration. It uses duplicity for the actual backup engine. You can currently backup to FTP(S) and Amazon S3.

The configuration is quite simple: write a config file in YAML describing what to backup and where, and here you go!

For data containers, it automatically mount the volumes shared by your container to backup and process it. For mysql containers, it links them and execute a mysqldump bundled with your container and process the result.

I wrote it because I use Docker-Cloud which is not up-to-date with recent docker-engine releases and because I wanted to embrace the Docker way by not including any process of backup inside my application containers.

Java method: Finding object in array list given a known attribute value

Assuming that you've written an equals method for Dog correctly that compares based on the id of the Dog the easiest and simplest way to return an item in the list is as follows.

if (dogList.contains(dog)) {
   return dogList.get(dogList.indexOf(dog));
}

That's less performance intensive that other approaches here. You don't need a loop at all in this case. Hope this helps.

P.S You can use Apache Commons Lang to write a simple equals method for Dog as follows:

@Override
public boolean equals(Object obj) {     
   EqualsBuilder builder = new EqualsBuilder().append(this.getId(), obj.getId());               
   return builder.isEquals();
}

Unzipping files

I wrote a class for that too. http://blog.another-d-mention.ro/programming/read-load-files-from-zip-in-javascript/ You can load basic assets such as javascript/css/images directly from the zip using class methods. Hope it helps

Improve SQL Server query performance on large tables

I know it's been quite a time since the beginning... There is a lot of wisdom in all these answers. Good indexing is the first thing when trying to improve a query. Well, almost the first. The most-first (so to speak) is making changes to code so that it's efficient. So, after all's been said and done, if one has a query with no WHERE, or when the WHERE-condition is not selective enough, there is only one way to get the data: TABLE SCAN (INDEX SCAN). If one needs all the columns from a table, then TABLE SCAN will be used - no question about it. This might be a heap scan or clustered index scan, depending on the type of data organization. The only last way to speed things up (if at all possible), is to make sure that as many cores are used as possible to do the scan: OPTION (MAXDOP 0). I'm ignoring the subject of storage, of course, but one should make sure that one has unlimited RAM, which goes without saying :)

Add Insecure Registry to Docker

I happened to encounter a similar kind of issue after setting up local internal JFrog Docker Private Registry on Amazon Linux.

THE followings I did to solve the issue:

Added "--insecure-registry xx.xx.xx.xx:8081" by modifying the OPTIONS variable in the /etc/sysconfig/docker file:

OPTIONS="--default-ulimit nofile=1024:40961 --insecure-registry hostname:8081"

Then restarted the docker.

I was then able to login to the local docker registry using:

docker login -u admin -p password hostname:8081

How to use JavaScript regex over multiple lines?

I have tested it (Chrome) and it working for me( both [^] and [^\0]), by changing the dot (.) by either [^\0] or [^] , because dot doesn't match line break (See here: http://www.regular-expressions.info/dot.html).

_x000D_
_x000D_
var ss= "<pre>aaaa\nbbb\nccc</pre>ddd";_x000D_
var arr= ss.match( /<pre[^\0]*?<\/pre>/gm );_x000D_
alert(arr);     //Working
_x000D_
_x000D_
_x000D_

Getting results between two dates in PostgreSQL

Assuming you want all "overlapping" time periods, i.e. all that have at least one day in common.

Try to envision time periods on a straight time line and move them around before your eyes and you will see the necessary conditions.

SELECT *
FROM   tbl
WHERE  start_date <= '2012-04-12'::date
AND    end_date   >= '2012-01-01'::date;

This is sometimes faster for me than OVERLAPS - which is the other good way to do it (as @Marco already provided).

Note the subtle difference (per documentation):

OVERLAPS automatically takes the earlier value of the pair as the start. Each time period is considered to represent the half-open interval start <= time < end, unless start and end are equal in which case it represents that single time instant. This means for instance that two time periods with only an endpoint in common do not overlap.

Bold emphasis mine.

Performance

For big tables the right index can help performance (a lot).

CREATE INDEX tbl_date_inverse_idx ON tbl(start_date, end_date DESC);

Possibly with another (leading) index column if you have additional selective conditions.

Note the inverse order of the two columns. Detailed explanation:

How to safely open/close files in python 2.4

Here is example given which so how to use open and "python close

from sys import argv
script,filename=argv
txt=open(filename)
print "filename %r" %(filename)
print txt.read()
txt.close()
print "Change the file name"
file_again=raw_input('>')
print "New file name %r" %(file_again)
txt_again=open(file_again)
print txt_again.read()
txt_again.close()

It's necessary to how many times you opened file have to close that times.

Master Page Weirdness - "Content controls have to be top-level controls in a content page or a nested master page that references a master page."

Better late than never i suppose... you get the option to set the MASTERPAGE only of you are developing a WEB SITE (FILE>NEW>WEBSITE)... but not when you create an ASP.NET project (FILE>NEW>PROJECT) - there you have to set the Masterpage using the properties of the newly created webform and it's up to you to modify the ASPX source to make it master page compliant (ie, removing the stock HTML, etc...)

How to change the style of the title attribute inside an anchor tag?

I thought i'd post my 20 lines JavaScript solution here. It is not perfect, but may be useful for some depending on what you need from your tooltips.

When to use it

  • Automatically styles the tooltip for all HTML elements with a TITLE attribute defined (this includes elements dynamically added to the document in the future)
  • No Javascript/HTML changes or hacks required for every tooltip (just the TITLE attribute, semantically clear)
  • Very light (adds about 300 bytes gzipped and minified)
  • You want only a very basic styleable tooltip

When NOT to use

  • Requires jQuery, so do not use if you don't use jQuery
  • Bad support for nested elements that both have tooltips
  • You need more than one tooltip on the screen at the same time
  • You need the tooltip to disappear after some time

The code

// Use a closure to keep vars out of global scope
(function () {
    var ID = "tooltip", CLS_ON = "tooltip_ON", FOLLOW = true,
    DATA = "_tooltip", OFFSET_X = 20, OFFSET_Y = 10,
    showAt = function (e) {
        var ntop = e.pageY + OFFSET_Y, nleft = e.pageX + OFFSET_X;
        $("#" + ID).html($(e.target).data(DATA)).css({
            position: "absolute", top: ntop, left: nleft
        }).show();
    };
    $(document).on("mouseenter", "*[title]", function (e) {
        $(this).data(DATA, $(this).attr("title"));
        $(this).removeAttr("title").addClass(CLS_ON);
        $("<div id='" + ID + "' />").appendTo("body");
        showAt(e);
    });
    $(document).on("mouseleave", "." + CLS_ON, function (e) {
        $(this).attr("title", $(this).data(DATA)).removeClass(CLS_ON);
        $("#" + ID).remove();
    });
    if (FOLLOW) { $(document).on("mousemove", "." + CLS_ON, showAt); }
}());

Paste it anywhere, it should work even when you run this code before the DOM is ready (it just won't show your tooltips until DOM is ready).

Customize

You can change the var declarations on the second line to customize it a bit.

var ID = "tooltip"; // The ID of the styleable tooltip
var CLS_ON = "tooltip_ON"; // Does not matter, make it somewhat unique
var FOLLOW = true; // TRUE to enable mouse following, FALSE to have static tooltips
var DATA = "_tooltip"; // Does not matter, make it somewhat unique
var OFFSET_X = 20, OFFSET_Y = 10; // Tooltip's distance to the cursor

Style

You can now style your tooltips using the following CSS:

#tooltip {
    background: #fff;
    border: 1px solid red;
    padding: 3px 10px;
}

String replace method is not replacing characters

You should re-assign the result of the replacement, like this:

 sentence = sentence.replace("and", " ");

Be aware that the String class is immutable, meaning that all of its methods return a new string and never modify the original string in-place, so the result of invoking a method in an instance of String must be assigned to a variable or used immediately for the change to take effect.

Set Page Title using PHP

It'll be tricky to rearrange your code to make this work, but I'll try :)

So, put this at the top of your code:

<?php require_once('mysql.php'); ?>

The top of the file should look like:

<?php require_once('mysql.php'); ?>
<html>
    <head>

    <meta name="keywords" content="Mac user Ultan Casey TheCompuGeeks UltanKC">
    <title>Ultan.me - <?php echo htmlspecialchars($title); ?> </title>

Then, create a file called mysql.php in the same directory that the file which contains the code you quoted is in.

Put this is mysql.php:

<?php
mysql_connect ('localhost', 'root', 'root');
mysql_select_db ('ultankc');

if (!isset($_GET['id']) || !is_numeric($_GET['id'])) {
    die("Invalid ID specified.");
}

$id = (int)$_GET['id'];
$sql = "SELECT * FROM php_blog WHERE id='$id' LIMIT 1";

$result = mysql_query($sql) or print ("Can't select entry from table php_blog.<br />" .       $sql . "<br />" . mysql_error());

$res = mysql_fetch_assoc($result); 

$date = date("l F d Y", $res['timestamp']);
$title = $res['title'];
$entry = $res['entry'];
$get_categories = mysql_query("SELECT * FROM php_blog_categories WHERE `category_id` = $res['category']");
$category = mysql_fetch_array($get_categories);

?>

Well, hope that helped :)

What is the dual table in Oracle?

DUAL is necessary in PL/SQL development for using functions that are only available in SQL

e.g.

DECLARE
x XMLTYPE;
BEGIN
SELECT xmlelement("hhh", 'stuff')
INTO x
FROM dual;
END;

What is the difference between URL parameters and query strings?

The query component is indicated by the first ? in a URI. "Query string" might be a synonym (this term is not used in the URI standard).

Some examples for HTTP URIs with query components:

http://example.com/foo?bar
http://example.com/foo/foo/foo?bar/bar/bar
http://example.com/?bar
http://example.com/?@bar._=???/1:
http://example.com/?bar1=a&bar2=b

(list of allowed characters in the query component)

The "format" of the query component is up to the URI authors. A common convention (but nothing more than a convention, as far as the URI standard is concerned¹) is to use the query component for key-value pairs, aka. parameters, like in the last example above: bar1=a&bar2=b.

Such parameters could also appear in the other URI components, i.e., the path² and the fragment. As far as the URI standard is concerned, it’s up to you which component and which format to use.

Example URI with parameters in the path, the query, and the fragment:

http://example.com/foo;key1=value1?key2=value2#key3=value3

¹ The URI standard says about the query component:

[…] query components are often used to carry identifying information in the form of "key=value" pairs […]

² The URI standard says about the path component:

[…] the semicolon (";") and equals ("=") reserved characters are often used to delimit parameters and parameter values applicable to that segment. The comma (",") reserved character is often used for similar purposes.

getting integer values from textfield

You need to use Integer.parseInt(String)

private void jTextField2MouseClicked(java.awt.event.MouseEvent evt) {
        if(evt.getSource()==jTextField2){
            int jml = Integer.parseInt(jTextField3.getText());
            jTextField1.setText(numberToWord(jml));

        }
    }

How to return a complex JSON response with Node.js?

[Edit] After reviewing the Mongoose documentation, it looks like you can send each query result as a separate chunk; the web server uses chunked transfer encoding by default so all you have to do is wrap an array around the items to make it a valid JSON object.

Roughly (untested):

app.get('/users/:email/messages/unread', function(req, res, next) {
  var firstItem=true, query=MessageInfo.find(/*...*/);
  res.writeHead(200, {'Content-Type': 'application/json'});
  query.each(function(docs) {
    // Start the JSON array or separate the next element.
    res.write(firstItem ? (firstItem=false,'[') : ',');
    res.write(JSON.stringify({ msgId: msg.fileName }));
  });
  res.end(']'); // End the JSON array and response.
});

Alternatively, as you mention, you can simply send the array contents as-is. In this case the response body will be buffered and sent immediately, which may consume a large amount of additional memory (above what is required to store the results themselves) for large result sets. For example:

// ...
var query = MessageInfo.find(/*...*/);
res.writeHead(200, {'Content-Type': 'application/json'});
res.end(JSON.stringify(query.map(function(x){ return x.fileName })));

How do I move a file from one location to another in Java?

Wrote this method to do this very thing on my own project only with the replace file if existing logic in it.

// we use the older file i/o operations for this rather than the newer jdk7+ Files.move() operation
private boolean moveFileToDirectory(File sourceFile, String targetPath) {
    File tDir = new File(targetPath);
    if (tDir.exists()) {
        String newFilePath = targetPath+File.separator+sourceFile.getName();
        File movedFile = new File(newFilePath);
        if (movedFile.exists())
            movedFile.delete();
        return sourceFile.renameTo(new File(newFilePath));
    } else {
        LOG.warn("unable to move file "+sourceFile.getName()+" to directory "+targetPath+" -> target directory does not exist");
        return false;
    }       
}

Bash foreach loop

If they all have the same extension (for example .jpg), you can use this:

for picture in  *.jpg ; do
    echo "the next file is $picture"
done

(This solution also works if the filename has spaces)

How to create relationships in MySQL

Certain MySQL engines support foreign keys. For example, InnoDB can establish constraints based on foreign keys. If you try to delete an entry in one table that has dependents in another, the delete will fail.

If you are using a table type in MySQL, such as MyISAM, that doesn't support foreign keys, you don't link the tables anywhere except your diagrams and queries.

For example, in a query you link two tables in a select statement with a join:

SELECT a, b from table1 LEFT JOIN table2 USING (common_field);

Floating point exception

It's caused by n % x, when x is 0. You should have x start at 2 instead. You should not use floating point here at all, since you only need integer operations.

General notes:

  1. Try to format your code better. Focus on using a consistent style. E.g. you have one else that starts immediately after a if brace (not even a space), and another with a newline in between.
  2. Don't use globals unless necessary. There is no reason for q to be global.
  3. Don't return without a value in a non-void (int) function.

Oracle DateTime in Where Clause?

Yes: TIME_CREATED contains a date and a time. Use TRUNC to strip the time:

SELECT EMP_NAME, DEPT
FROM EMPLOYEE
WHERE TRUNC(TIME_CREATED) = TO_DATE('26/JAN/2011','dd/mon/yyyy')

UPDATE:
As Dave Costa points out in the comment below, this will prevent Oracle from using the index of the column TIME_CREATED if it exists. An alternative approach without this problem is this:

SELECT EMP_NAME, DEPT
FROM EMPLOYEE
WHERE TIME_CREATED >= TO_DATE('26/JAN/2011','dd/mon/yyyy') 
      AND TIME_CREATED < TO_DATE('26/JAN/2011','dd/mon/yyyy') + 1

Getting Error - ORA-01858: a non-numeric character was found where a numeric was expected

The error you are getting is either because you are doing TO_DATE on a column that's already a date, and you're using a format mask that is different to your nls_date_format parameter[1] or because the event_occurrence column contains data that isn't a number.

You need to a) correct your query so that it's not using TO_DATE on the date column, and b) correct your data, if event_occurrence is supposed to be just numbers.

And fix the datatype of that column to make sure you can only store numbers.



[1] What Oracle does when you do: TO_DATE(date_column, non_default_format_mask) is: TO_DATE(TO_CHAR(date_column, nls_date_format), non_default_format_mask)

Generally, the default nls_date_format parameter is set to dd-MON-yy, so in your query, what is likely to be happening is your date column is converted to a string in the format dd-MON-yy, and you're then turning it back to a date using the format MMDD. The string is not in this format, so you get an error.

How to zip a file using cmd line?

If you want a simple program that will run with .net 4.6.1 or above on Windows, I wrote this for my own purposes after finding this question.

You simply cd to the directory above the folder you want to zip, then pass in the directory name and it will output mydir.zip. Add zipper to your path, I personally have a utils folder on C:\utils that have things like this in it.

cd C:\Users\SomeUser\Desktop\
zipper myfolder

Below is the source code and copy of the exe:

https://github.com/tryonlinux/commandLineZipper

Javascript ES6/ES5 find in array and change

worked for me

let returnPayments = [ ...this.payments ];

returnPayments[this.payments.findIndex(x => x.id == this.payment.id)] = this.payment;

Python loop to run for certain amount of seconds

Simply You can do it

import time
delay=60*15    ###for 15 minutes delay 
close_time=time.time()+delay
while True:
      ##bla bla
      ###bla bla
     if time.time()>close_time
         break

HTML5 and frameborder

How about using the same for technique for "fooling" the validator with Javascript by sticking a target attribute in XHTML <a onclick="this.target='_blank'">?

  • onsomething = " this.frameborder = '0' "

<iframe onload = " this.frameborder='0' " src="menu.html" id="menu"> </iframe>

Or getElementsByTagName]("iframe")1 adding this attribute for all iframes on the page?

Haven't tested this because I've done something which means that nothing is working in IE less than 9! :) So while I'm sorting that out ... :)

Convert Object to JSON string

Also useful is Object.toSource() for debugging purposes, where you want to show the object and its properties for debugging purposes. This is a generic Javascript (not jQuery) function, however it only works in "modern" browsers.

XAMPP - Apache could not start - Attempting to start Apache service

IF PORT 80 IS NOT THE ISSUE!

Check to see if the port 80 is in use first as this can be an issue. You can do this by typing "netstat -an" into cmd. The look for 0.0.0.0:80 under Local Address, if you find this is in use then follow the solution from @Karthik. However, I had a similar issue but my port 80 was not in use. My XAMPP had wrong paths locations, steps to fix this:

1.Find out the Apache version you are using, you can find this by looking in Services (Control panel, Admin Tools, Services) and finding Apache in my case it was listed as Apache2.4

2.Close XAMPP.

3.Run cmd as admin.

4.execute 'sc delete "Apache2.4"' (put your version in place of mine and without the surrounding ' ', but with the " " around Apache).

5.execute 'sc delete "mySQL"', again remove the '' when you type it.

6.reopen XAMPP and try starting Apache

If you are having trouble with FileZill, Mercury, or Tomcat you could try it here too, but I have not tested that myself.

Hope this helps!

How to import an Oracle database from dmp file and log file?

All this peace of code put into *.bat file and run all at once:

My code for creating user in oracle. crate_drop_user.sql file

drop user "USER" cascade;
DROP TABLESPACE "USER";

CREATE TABLESPACE USER DATAFILE 'D:\ORA_DATA\ORA10\USER.ORA' SIZE 10M REUSE 
    AUTOEXTEND 
    ON NEXT  5M  EXTENT MANAGEMENT LOCAL 
    SEGMENT SPACE MANAGEMENT  AUTO
/ 

CREATE  TEMPORARY TABLESPACE "USER_TEMP" TEMPFILE 
    'D:\ORA_DATA\ORA10\USER_TEMP.ORA' SIZE 10M REUSE AUTOEXTEND
    ON NEXT  5M  EXTENT MANAGEMENT LOCAL 
    UNIFORM SIZE 1M    
/

CREATE USER "USER"  PROFILE "DEFAULT" 
    IDENTIFIED BY "user_password" DEFAULT TABLESPACE "USER" 
    TEMPORARY TABLESPACE "USER_TEMP" 
/    

alter user USER quota unlimited on "USER";

GRANT CREATE PROCEDURE TO "USER";
GRANT CREATE PUBLIC SYNONYM TO "USER";
GRANT CREATE SEQUENCE TO "USER";
GRANT CREATE SNAPSHOT TO "USER";
GRANT CREATE SYNONYM TO "USER";
GRANT CREATE TABLE TO "USER";
GRANT CREATE TRIGGER TO "USER";
GRANT CREATE VIEW TO "USER";
GRANT "CONNECT" TO "USER";
GRANT SELECT ANY DICTIONARY to "USER";
GRANT CREATE TYPE TO "USER";

create file import.bat and put this lines in it:

SQLPLUS SYSTEM/systempassword@ORA_alias @"crate_drop_user.SQL"
IMP SYSTEM/systempassword@ORA_alias FILE=user.DMP FROMUSER=user TOUSER=user GRANTS=Y log =user.log

Be carefull if you will import from one user to another. For example if you have user named user1 and you will import to user2 you may lost all grants , so you have to recreate it.

Good luck, Ivan

When to use MyISAM and InnoDB?

Read about Storage Engines.

MyISAM:

The MyISAM storage engine in MySQL.

  • Simpler to design and create, thus better for beginners. No worries about the foreign relationships between tables.
  • Faster than InnoDB on the whole as a result of the simpler structure thus much less costs of server resources. -- Mostly no longer true.
  • Full-text indexing. -- InnoDB has it now
  • Especially good for read-intensive (select) tables. -- Mostly no longer true.
  • Disk footprint is 2x-3x less than InnoDB's. -- As of Version 5.7, this is perhaps the only real advantage of MyISAM.

InnoDB:

The InnoDB storage engine in MySQL.

  • Support for transactions (giving you support for the ACID property).
  • Row-level locking. Having a more fine grained locking-mechanism gives you higher concurrency compared to, for instance, MyISAM.
  • Foreign key constraints. Allowing you to let the database ensure the integrity of the state of the database, and the relationships between tables.
  • InnoDB is more resistant to table corruption than MyISAM.
  • Support for large buffer pool for both data and indexes. MyISAM key buffer is only for indexes.
  • MyISAM is stagnant; all future enhancements will be in InnoDB. This was made abundantly clear with the roll out of Version 8.0.

MyISAM Limitations:

  • No foreign keys and cascading deletes/updates
  • No transactional integrity (ACID compliance)
  • No rollback abilities
  • 4,284,867,296 row limit (2^32) -- This is old default. The configurable limit (for many versions) has been 2**56 bytes.
  • Maximum of 64 indexes per table

InnoDB Limitations:

  • No full text indexing (Below-5.6 mysql version)
  • Cannot be compressed for fast, read-only (5.5.14 introduced ROW_FORMAT=COMPRESSED)
  • You cannot repair an InnoDB table

For brief understanding read below links:

  1. MySQL Engines: InnoDB vs. MyISAM – A Comparison of Pros and Cons
  2. MySQL Engines: MyISAM vs. InnoDB
  3. What are the main differences between InnoDB and MyISAM?
  4. MyISAM versus InnoDB
  5. What's the difference between MyISAM and InnoDB?
  6. MySql: MyISAM vs. Inno DB!

Naming conventions for Java methods that return boolean

The convention is to ask a question in the name.

Here are a few examples that can be found in the JDK:

isEmpty()

hasChildren()

That way, the names are read like they would have a question mark on the end.

Is the Collection empty?
Does this Node have children?

And, then, true means yes, and false means no.

Or, you could read it like an assertion:

The Collection is empty.
The node has children

Note:
Sometimes you may want to name a method something like createFreshSnapshot?. Without the question mark, the name implies that the method should be creating a snapshot, instead of checking to see if one is required.

In this case you should rethink what you are actually asking. Something like isSnapshotExpired is a much better name, and conveys what the method will tell you when it is called. Following a pattern like this can also help keep more of your functions pure and without side effects.

If you do a Google Search for isEmpty() in the Java API, you get lots of results.

Convert HTML5 into standalone Android App

You could use PhoneGap.

http://phonegap.com/

http://docs.phonegap.com/en/2.1.0/guide_getting-started_android_index.md.html#Getting%20Started%20with%20Android

This has the benefit of being a cross-platform solution. Be warned though that you may need to pay subscription fees. The simplest solution is to just embed a WebView as detailed in @Enigma's answer.

php artisan migrate throwing [PDO Exception] Could not find driver - Using Laravel

I think you missed the mysql driver for php5. Execute below command:

sudo apt-get install php5-mysql
/etc/init.d/php5-fpm restart

How to create byte array from HttpPostedFile

in your question, both buffer and byteArray seem to be byte[]. So:

ImageElement image = ImageElement.FromBinary(buffer);

Clearing input in vuejs form

These solutions are good but if you want to go for less work then you can use $refs

<form ref="anyName" @submit="submitForm">
</form>

<script>
   methods: {
      submitForm(){
         // Your form submission
         this.$refs.anyName.reset(); // This will clear that form
      }
   }
</script>

What is the difference between Html.Hidden and Html.HiddenFor

Most of the MVC helper methods have a XXXFor variant. They are intended to be used in conjunction with a concrete model class. The idea is to allow the helper to derive the appropriate "name" attribute for the form-input control based on the property you specify in the lambda. This means that you get to eliminate "magic strings" that you would otherwise have to employ to correlate the model properties with your views. For example:

Html.Hidden("Name", "Value")

Will result in:

<input id="Name" name="Name" type="hidden" value="Value">

In your controller, you might have an action like:

[HttpPost]
public ActionResult MyAction(MyModel model) 
{
}

And a model like:

public class MyModel 
{
    public string Name { get; set; }
}

The raw Html.Hidden we used above will get correlated to the Name property in the model. However, it's somewhat distasteful that the value "Name" for the property must be specified using a string ("Name"). If you rename the Name property on the Model, your code will break and the error will be somewhat difficult to figure out. On the other hand, if you use HiddenFor, you get protected from that:

Html.HiddenFor(x => x.Name, "Value");

Now, if you rename the Name property, you will get an explicit runtime error indicating that the property can't be found. In addition, you get other benefits of static analysis, such as getting a drop-down of the members after typing x..

How do I get the fragment identifier (value after hash #) from a URL?

You may do it by using following code:

var url = "www.site.com/index.php#hello";
var hash = url.substring(url.indexOf('#')+1);
alert(hash);

SEE DEMO

Merge unequal dataframes and replace missing rows with 0

Another alternative with data.table.

EXAMPLE DATA

dt1 <- data.table(df1)
dt2 <- data.table(df2)
setkey(dt1,x)
setkey(dt2,x)

CODE

dt2[dt1,list(y=ifelse(is.na(y),0,y))]

How to get different colored lines for different plots in a single figure?

Matplotlib does this by default.

E.g.:

import matplotlib.pyplot as plt
import numpy as np

x = np.arange(10)

plt.plot(x, x)
plt.plot(x, 2 * x)
plt.plot(x, 3 * x)
plt.plot(x, 4 * x)
plt.show()

Basic plot demonstrating color cycling

And, as you may already know, you can easily add a legend:

import matplotlib.pyplot as plt
import numpy as np

x = np.arange(10)

plt.plot(x, x)
plt.plot(x, 2 * x)
plt.plot(x, 3 * x)
plt.plot(x, 4 * x)

plt.legend(['y = x', 'y = 2x', 'y = 3x', 'y = 4x'], loc='upper left')

plt.show()

Basic plot with legend

If you want to control the colors that will be cycled through:

import matplotlib.pyplot as plt
import numpy as np

x = np.arange(10)

plt.gca().set_color_cycle(['red', 'green', 'blue', 'yellow'])

plt.plot(x, x)
plt.plot(x, 2 * x)
plt.plot(x, 3 * x)
plt.plot(x, 4 * x)

plt.legend(['y = x', 'y = 2x', 'y = 3x', 'y = 4x'], loc='upper left')

plt.show()

Plot showing control over default color cycling

If you're unfamiliar with matplotlib, the tutorial is a good place to start.

Edit:

First off, if you have a lot (>5) of things you want to plot on one figure, either:

  1. Put them on different plots (consider using a few subplots on one figure), or
  2. Use something other than color (i.e. marker styles or line thickness) to distinguish between them.

Otherwise, you're going to wind up with a very messy plot! Be nice to who ever is going to read whatever you're doing and don't try to cram 15 different things onto one figure!!

Beyond that, many people are colorblind to varying degrees, and distinguishing between numerous subtly different colors is difficult for more people than you may realize.

That having been said, if you really want to put 20 lines on one axis with 20 relatively distinct colors, here's one way to do it:

import matplotlib.pyplot as plt
import numpy as np

num_plots = 20

# Have a look at the colormaps here and decide which one you'd like:
# http://matplotlib.org/1.2.1/examples/pylab_examples/show_colormaps.html
colormap = plt.cm.gist_ncar
plt.gca().set_prop_cycle(plt.cycler('color', plt.cm.jet(np.linspace(0, 1, num_plots))))

# Plot several different functions...
x = np.arange(10)
labels = []
for i in range(1, num_plots + 1):
    plt.plot(x, i * x + 5 * i)
    labels.append(r'$y = %ix + %i$' % (i, 5*i))

# I'm basically just demonstrating several different legend options here...
plt.legend(labels, ncol=4, loc='upper center', 
           bbox_to_anchor=[0.5, 1.1], 
           columnspacing=1.0, labelspacing=0.0,
           handletextpad=0.0, handlelength=1.5,
           fancybox=True, shadow=True)

plt.show()

Unique colors for 20 lines based on a given colormap

Apache default VirtualHost

If you are using Debian style virtual host configuration (sites-available/sites-enabled), one way to set a Default VirtualHost is to include the specific configuration file first in httpd.conf or apache.conf (or what ever is your main configuration file).

# To set default VirtualHost, include it before anything else.
IncludeOptional sites-enabled/my.site.com.conf

# Load config files in the "/etc/httpd/conf.d" directory, if any.
IncludeOptional conf.d/*.conf

# Load virtual host config files from "/etc/httpd/sites-enabled/".
IncludeOptional sites-enabled/*.conf

CSS container div not getting height

The best and the most bulletproof solution is to add ::before and ::after pseudoelements to the container. So if you have for example a list like:

<ul class="clearfix">
    <li></li>
    <li></li>
    <li></li>
</ul>

And every elements in the list has float:left property, then you should add to your css:

.clearfix::after, .clearfix::before {
     content: '';
     clear: both;
     display: table;
}

Or you could try display:inline-block; property, then you don't need to add any clearfix.