Programs & Examples On #Decibel

Anything related to the usage of the decibel (dB). The decibel is a logarithmic unit of measurement commonly used in electronics and communication engineering.

PreparedStatement setNull(..)

but watch out for this....

Long nullLong = null;

preparedStatement.setLong( nullLong );

-thows null pointer exception-

because the protype is

setLong( long )   

NOT

setLong( Long )

nice one to catch you out eh.

Python Script to convert Image into Byte array

This works for me

# Convert image to bytes
import PIL.Image as Image
pil_im = Image.fromarray(image)
b = io.BytesIO()
pil_im.save(b, 'jpeg')
im_bytes = b.getvalue()
return im_bytes

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

If it is one (single) branch that you need to check, for example if you want that branch 'B' is fully merged into branch 'A', you can simply do the following:

$ git checkout A
$ git branch -d B

git branch -d <branchname> has the safety that "The branch must be fully merged in HEAD."

Caution: this actually deletes the branch B if it is merged into A.

sed whole word search and replace

In one of my machine, delimiting the word with "\b" (without the quotes) did not work. The solution was to use "\<" for starting delimiter and "\>" for ending delimiter.

To explain with Joakim Lundberg's example:

$ echo "bar embarassment" | sed "s/\<bar\>/no bar/g"
no bar embarassment

C++ template constructor

You could do this:

class C 
{
public:
    template <typename T> C(T*);
};
template <typename T> T* UseType() 
{
    static_cast<T*>(nullptr);
}

Then to create an object of type C using int as the template parameter to the constructor:

C obj(UseType<int>());

Since you can't pass template parameters to a constructor, this solution essentially converts the template parameter to a regular parameter. Using the UseType<T>() function when calling the constructor makes it clear to someone looking at the code that the purpose of that parameter is to tell the constructor what type to use.

One use case for this would be if the constructor creates a derived class object and assigns it to a member variable that is a base class pointer. (The constructor needs to know which derived class to use, but the class itself doesn't need to be templated since the same base class pointer type is always used.)

What’s the difference between Response.Write() andResponse.Output.Write()?

Here Response.Write():to display only string and you can not display any other data type values like int,date,etc.Conversion(from one data type to another) is not allowed. whereas Response .Output .Write(): you can display any type of data like int, date ,string etc.,by giving index values.

Here is example:

protected void Button1_Click(object sender, EventArgs e)
    {
       Response.Write ("hi good morning!"+"is it right?");//only strings are allowed        
       Response.Write("Scott is {0} at {1:d}", "cool", DateTime.Now);//this will give error(conversion is not allowed)
       Response.Output.Write("\nhi goood morning!");//works fine
       Response.Output.Write("Jai is {0} on {1:d}", "cool", DateTime.Now);//here the current date will be converted into string and displayed
    }

Visual Studio 2010 always thinks project is out of date, but nothing has changed

This happened to me multiple times and then went away, before I could figure out why. In my case it was:

Wrong system time in the dual boot setup!

Turns out, my dual boot with Ubuntu was the root cause!! I've been too lazy to fix up Ubuntu to stop messing with my hardware clock. When I log into Ubuntu, the time jumps 5 hours forward.

Out of bad luck, I built the project once, with the wrong system time, then corrected the time. As a result, all the build files had wrong timestamps, and VS would think they are all out of date and would rebuild the project.

fatal: bad default revision 'HEAD'

just do an initial commit and the error will go away:

git commit -m "initial commit"

Set QLineEdit to accept only numbers

You could also set an inputMask:

QLineEdit.setInputMask("9")

This allows the user to type only one digit ranging from 0 to 9. Use multiple 9's to allow the user to enter multiple numbers. See also the complete list of characters that can be used in an input mask.

(My answer is in Python, but it should not be hard to transform it to C++)

HTML embed autoplay="false", but still plays automatically

<embed ... autostart="0">

Replace false with 0

jQuery OR Selector?

Daniel A. White Solution works great for classes.

I've got a situation where I had to find input fields like donee_1_card where 1 is an index.

My solution has been

$("input[name^='donee']" && "input[name*='card']")

Though I am not sure how optimal it is.

Enabling SSL with XAMPP

For XAMPP, do the following steps:

  1. G:\xampp\apache\conf\extra\httpd-ssl.conf"

  2. Search 'DocumentRoot' text.

  3. Change DocumentRoot DocumentRoot "G:/xampp/htdocs" to DocumentRoot "G:/xampp/htdocs/project name".

How to set session timeout in web.config

If you want to set the timeout to 20 minutes, use something like this:

    <configuration>
      <system.web>
         <sessionState timeout="20"></sessionState>
      </system.web>
    </configuration>

Taking multiple inputs from user in python

My first impression was that you were wanting a looping command-prompt with looping user-input inside of that looping command-prompt. (Nested user-input.) Maybe it's not what you wanted, but I already wrote this answer before I realized that. So, I'm going to post it in case other people (or even you) find it useful.

You just need nested loops with an input statement at each loop's level.

For instance,

data=""
while 1:
    data=raw_input("Command: ")
    if data in ("test", "experiment", "try"):
        data2=""
        while data2=="":
            data2=raw_input("Which test? ")
        if data2=="chemical":
            print("You chose a chemical test.")
        else:
            print("We don't have any " + data2 + " tests.")
    elif data=="quit":
        break
    else:
        pass

Fit Image in ImageButton in Android

I want them to cover 75% of the button area.

Use android:padding="20dp" (adjust the padding as needed) to control how much the image takes up on the button.

but where as some images cover less area, some are too big to fit into the imageButton. How to programatically resize and show them?

Use a android:scaleType="fitCenter" to have Android scale the images, and android:adjustViewBounds="true" to have them adjust their bounds due to scaling.

All of these attributes can be set in code on each ImageButton at runtime. However, it is much easier to set and preview in xml in my opinion.

Also, do not use sp for anything other than text size, it is scaled depending on the text size preference the user sets, so your sp dimensions will be larger than your intended if the user has a "large" text setting. Use dp instead, as it is not scaled by the user's text size preference.

Here's a snippet of what each button should look like:

    <ImageButton
        android:id="@+id/button_topleft"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_marginBottom="5dp"
        android:layout_marginLeft="2dp"
        android:layout_marginRight="5dp"
        android:layout_marginTop="0dp"
        android:layout_weight="1"
        android:adjustViewBounds="true"
        android:padding="20dp"
        android:scaleType="fitCenter" />

Sample Button

How to split a string between letters and digits (or between digits and letters)?

If you are looking for solution without using Java String functionality (i.e. split, match, etc.) then the following should help:

List<String> splitString(String string) {
        List<String> list = new ArrayList<String>();
        String token = "";
        char curr;
        for (int e = 0; e < string.length() + 1; e++) {
            if (e == 0)
                curr = string.charAt(0);
            else {
                curr = string.charAt(--e);
            }

            if (isNumber(curr)) {
                while (e < string.length() && isNumber(string.charAt(e))) {
                    token += string.charAt(e++);
                }
                list.add(token);
                token = "";
            } else {
                while (e < string.length() && !isNumber(string.charAt(e))) {
                    token += string.charAt(e++);
                }
                list.add(token);
                token = "";
            }

        }

        return list;
    }

boolean isNumber(char c) {
        return c >= '0' && c <= '9';
    }

This solution will split numbers and 'words', where 'words' are strings that don't contain numbers. However, if you like to have only 'words' containing English letters then you can easily modify it by adding more conditions (like isNumber method call) depending on your requirements (for example you may wish to skip words that contain non English letters). Also note that the splitString method returns ArrayList which later can be converted to String array.

Shell script not running, command not found

First:

chmod 777 ./MigrateNshell.sh

Then:

./MigrateNshell.sh

Or, add your program to a directory recognized in your $PATH variable. Example: Path Variable Example Which will then allow you to call your program without ./

Display UIViewController as Popup in iPhone

You can do this in Interface Builder.

  • For the view you wish to present modally set its outermost view background to transparent
  • Control + click and drag from the host view controller to the modal view controller
  • Select present modally
  • Click on the newly created segue and in the Attribute Inspector (on the right) set "Presentation" to "Over Current Context"

Convert XmlDocument to String

As an extension method:

public static class Extensions
{
    public static string AsString(this XmlDocument xmlDoc)
    {
        using (StringWriter sw = new StringWriter())
        {
            using (XmlTextWriter tx = new XmlTextWriter(sw))
            {
                xmlDoc.WriteTo(tx);
                string strXmlText = sw.ToString();
                return strXmlText;
            }
        }
    }
}

Now to use simply:

yourXmlDoc.AsString()

ADB Driver and Windows 8.1

http://adbdriver.com/

this worked for me, in my latest Micromax Yu Yuphoria! just download the installer and install it

Android - How to achieve setOnClickListener in Kotlin?

You use like that onclickListener in kotlin

val fab = findViewById(R.id.fab) as FloatingActionButton
fab.setOnClickListener {  
...
}

What are Transient and Volatile Modifiers?

The volatile and transient modifiers can be applied to fields of classes1 irrespective of field type. Apart from that, they are unrelated.

The transient modifier tells the Java object serialization subsystem to exclude the field when serializing an instance of the class. When the object is then deserialized, the field will be initialized to the default value; i.e. null for a reference type, and zero or false for a primitive type. Note that the JLS (see 8.3.1.3) does not say what transient means, but defers to the Java Object Serialization Specification. Other serialization mechanisms may pay attention to a field's transient-ness. Or they may ignore it.

(Note that the JLS permits a static field to be declared as transient. This combination doesn't make sense for Java Object Serialization, since it doesn't serialize statics anyway. However, it could make sense in other contexts, so there is some justification for not forbidding it outright.)

The volatile modifier tells the JVM that writes to the field should always be synchronously flushed to memory, and that reads of the field should always read from memory. This means that fields marked as volatile can be safely accessed and updated in a multi-thread application without using native or standard library-based synchronization. Similarly, reads and writes to volatile fields are atomic. (This does not apply to >>non-volatile<< long or double fields, which may be subject to "word tearing" on some JVMs.) The relevant parts of the JLS are 8.3.1.4, 17.4 and 17.7.


1 - But not to local variables or parameters.

Python: create dictionary using dict() with integer keys?

There are also these 'ways':

>>> dict.fromkeys(range(1, 4))
{1: None, 2: None, 3: None}
>>> dict(zip(range(1, 4), range(1, 4)))
{1: 1, 2: 2, 3: 3}

iOS start Background Thread

If you use performSelectorInBackground:withObject: to spawn a new thread, then the performed selector is responsible for setting up the new thread's autorelease pool, run loop and other configuration details – see "Using NSObject to Spawn a Thread" in Apple's Threading Programming Guide.

You'd probably be better off using Grand Central Dispatch, though:

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    [self getResultSetFromDB:docids];
});

GCD is a newer technology, and is more efficient in terms of memory overhead and lines of code.


Updated with a hat tip to Chris Nolet, who suggested a change that makes the above code simpler and keeps up with Apple's latest GCD code examples.

Python threading. How do I lock a thread?

You can see that your locks are pretty much working as you are using them, if you slow down the process and make them block a bit more. You had the right idea, where you surround critical pieces of code with the lock. Here is a small adjustment to your example to show you how each waits on the other to release the lock.

import threading
import time
import inspect

class Thread(threading.Thread):
    def __init__(self, t, *args):
        threading.Thread.__init__(self, target=t, args=args)
        self.start()

count = 0
lock = threading.Lock()

def incre():
    global count
    caller = inspect.getouterframes(inspect.currentframe())[1][3]
    print "Inside %s()" % caller
    print "Acquiring lock"
    with lock:
        print "Lock Acquired"
        count += 1  
        time.sleep(2)  

def bye():
    while count < 5:
        incre()

def hello_there():
    while count < 5:
        incre()

def main():    
    hello = Thread(hello_there)
    goodbye = Thread(bye)


if __name__ == '__main__':
    main()

Sample output:

...
Inside hello_there()
Acquiring lock
Lock Acquired
Inside bye()
Acquiring lock
Lock Acquired
...

Show git diff on file in staging area

You can also use git diff HEAD file to show the diff for a specific file.

See the EXAMPLE section under git-diff(1)

member names cannot be the same as their enclosing type C#

The problem is with the method:

private void Flow()
{
    X = x;
    Y = y;
}

Your class is named Flow so this method can't also be named Flow. You will have to change the name of the Flow method to something else to make this code compile.

Or did you mean to create a private constructor to initialize your class? If that's the case, you will have to remove the void keyword to let the compiler know that your declaring a constructor.

AngularJS - How can I do a redirect with a full page load?

After searching and giving hit and trial session I am able to solove it by first specifying url like

$window.location.href = '/#/home/stats';

then reload

$window.location.reload();

java.lang.NoClassDefFoundError: org/apache/http/client/HttpClient

I was facing the same issue. In my case, I had a dependency of httpclient with an older version while sendgrid required a newer version of httpclient. Just make sure that the version of httpclient is correct in your dependencies and it would work fine.

How to embed fonts in HTML?

And it's unlikely too -- EOT is a fairly restrictive format that is supported only by IE. Both Safari 3.1 and Firefox 3.1 (well the current alpha) and possibly Opera 9.6 support true type font (ttf) embedding, and at least Safari supports SVG fonts through the same mechanism. A list apart had a good discussion about this a while back.

How to delete mysql database through shell command

Another suitable way:

$ mysql -u you -p
<enter password>

>>> DROP DATABASE foo;

Returning boolean if set is empty

Not as clean as bool(c) but it was an excuse to use ternary.

def myfunc(a,b):
    return True if a.intersection(b) else False

Also using a bit of the same logic there is no need to assign to c unless you are using it for something else.

def myfunc(a,b):
    return bool(a.intersection(b))

Finally, I would assume you want a True / False value because you are going to perform some sort of boolean test with it. I would recommend skipping the overhead of a function call and definition by simply testing where you need it.

Instead of:

if (myfunc(a,b)):
    # Do something

Maybe this:

if a.intersection(b):
    # Do something

Django: ImproperlyConfigured: The SECRET_KEY setting must not be empty

try import django then run django.setup() after the secret_key definition. like so:

SECRET_KEY = 'it5bs))q6toz-1gwf(+j+f9@rd8%_-0nx)p-2!egr*y1o51=45XXCV'
django.setup()

jquery: animate scrollLeft

You'll want something like this:


$("#next").click(function(){
      var currentElement = currentElement.next();
      $('html, body').animate({scrollLeft: $(currentElement).offset().left}, 800);
      return false;
   }); 
I believe this should work, it's adopted from a scrollTop function.

Loop through an array of strings in Bash?

Surprised that nobody's posted this yet -- if you need the indices of the elements while you're looping through the array, you can do this:

arr=(foo bar baz)

for i in ${!arr[@]}
do
    echo $i "${arr[i]}"
done

Output:

0 foo
1 bar
2 baz

I find this a lot more elegant than the "traditional" for-loop style (for (( i=0; i<${#arr[@]}; i++ ))).

(${!arr[@]} and $i don't need to be quoted because they're just numbers; some would suggest quoting them anyway, but that's just personal preference.)

Annotation @Transactional. How to rollback?

or programatically

TransactionAspectSupport.currentTransactionStatus().setRollbackOnly();

Print all key/value pairs in a Java ConcurrentHashMap

The HashMap has forEach as part of its structure. You can use that with a lambda expression to print out the contents in a one liner such as:

map.forEach((k,v)-> System.out.println(k+", "+v));

or

map.forEach((k,v)-> System.out.println("key: "+k+", value: "+v));

Background blur with CSS

In which way do you want it dynamic? If you want the popup to successfully map to the background, you need to create two backgrounds. It requires both the use of element() or -moz-element() and a filter (for Firefox, use a SVG filter like filter: url(#svgBlur) since Firefox does not support -moz-filter: blur() as yet?). It only works in Firefox at the time of writing.

See demo here.

I still need to create a simple demo to show how it is done. You're welcome to view the source.

Best way to write to the console in PowerShell

The middle one writes to the pipeline. Write-Host and Out-Host writes to the console. 'echo' is an alias for Write-Output which writes to the pipeline as well. The best way to write to the console would be using the Write-Host cmdlet.

When an object is written to the pipeline it can be consumed by other commands in the chain. For example:

"hello world" | Do-Something

but this won't work since Write-Host writes to the console, not to the pipeline (Do-Something will not get the string):

Write-Host "hello world" | Do-Something

Draw on HTML5 Canvas using a mouse

check this http://jsfiddle.net/ArtBIT/kneDX/. This should direct you on the right direction

RequestDispatcher.forward() vs HttpServletResponse.sendRedirect()

In the web development world, the term "redirect" is the act of sending the client an empty HTTP response with just a Location header containing the new URL to which the client has to send a brand new GET request. So basically:

  • Client sends a HTTP request to some.jsp.
  • Server sends a HTTP response back with Location: other.jsp header
  • Client sends a HTTP request to other.jsp (this get reflected in browser address bar!)
  • Server sends a HTTP response back with content of other.jsp.

You can track it with the web browser's builtin/addon developer toolset. Press F12 in Chrome/IE9/Firebug and check the "Network" section to see it.

Exactly the above is achieved by sendRedirect("other.jsp"). The RequestDispatcher#forward() doesn't send a redirect. Instead, it uses the content of the target page as HTTP response.

  • Client sends a HTTP request to some.jsp.
  • Server sends a HTTP response back with content of other.jsp.

However, as the original HTTP request was to some.jsp, the URL in browser address bar remains unchanged. Also, any request attributes set in the controller behind some.jsp will be available in other.jsp. This does not happen during a redirect because you're basically forcing the client to create a new HTTP request on other.jsp, hereby throwing away the original request on some.jsp including all of its attribtues.


The RequestDispatcher is extremely useful in the MVC paradigm and/or when you want to hide JSP's from direct access. You can put JSP's in the /WEB-INF folder and use a Servlet which controls, preprocesses and postprocesses the requests. The JSPs in the /WEB-INF folder are not directly accessible by URL, but the Servlet can access them using RequestDispatcher#forward().

You can for example have a JSP file in /WEB-INF/login.jsp and a LoginServlet which is mapped on an url-pattern of /login. When you invoke http://example.com/context/login, then the servlet's doGet() will be invoked. You can do any preprocessing stuff in there and finally forward the request like:

request.getRequestDispatcher("/WEB-INF/login.jsp").forward(request, response);

When you submit a form, you normally want to use POST:

<form action="login" method="post">

This way the servlet's doPost() will be invoked and you can do any postprocessing stuff in there (e.g. validation, business logic, login the user, etc).

If there are any errors, then you normally want to forward the request back to the same page and display the errors there next to the input fields and so on. You can use the RequestDispatcher for this.

If a POST is successful, you normally want to redirect the request, so that the request won't be resubmitted when the user refreshes the request (e.g. pressing F5 or navigating back in history).

User user = userDAO.find(username, password);
if (user != null) {
    request.getSession().setAttribute("user", user); // Login user.
    response.sendRedirect("home"); // Redirects to http://example.com/context/home after succesful login.
} else {
    request.setAttribute("error", "Unknown login, please try again."); // Set error.
    request.getRequestDispatcher("/WEB-INF/login.jsp").forward(request, response); // Forward to same page so that you can display error.
}

A redirect thus instructs the client to fire a new GET request on the given URL. Refreshing the request would then only refresh the redirected request and not the initial request. This will avoid "double submits" and confusion and bad user experiences. This is also called the POST-Redirect-GET pattern.

See also:

How to create a batch file to run cmd as administrator

Maybe something like this:

if "%~s0"=="%~s1" ( cd %~sp1 & shift ) else (
  echo CreateObject^("Shell.Application"^).ShellExecute "%~s0","%~0 %*","","runas",1 >"%tmp%%~n0.vbs" & "%tmp%%~n0.vbs" & del /q "%tmp%%~n0.vbs" & goto :eof
)

Make page to tell browser not to cache/preserve input values

From a Stack Overflow reference

It did not work with value="" if the browser already saves the value so you should add.

For an input tag there's the attribute autocomplete you can set:

<input type="text" autocomplete="off" />

You can use autocomplete for a form too.

How to access data/data folder in Android device?

I had also the same problem once. There is no way to access directly the file within android devices except adb shell or rooting device.

Beside here are 02 alternatives:

1)

 public void exportDatabse(String databaseName)
   {
     try {
        File sd = Environment.getExternalStorageDirectory();
        File data = Environment.getDataDirectory();

        if (sd.canWrite()) {
            String currentDBPath = "//data//"+getPackageName()+"//databases//"+databaseName+"";
            String backupDBPath = "backupname.db";
            File currentDB = new File(data, currentDBPath);
            File backupDB = new File(sd, backupDBPath);

            if (currentDB.exists()) {
                FileChannel src = new FileInputStream(currentDB).getChannel();
                FileChannel dst = new FileOutputStream(backupDB).getChannel();
                dst.transferFrom(src, 0, src.size());
                src.close();
                dst.close();
            }
        }
    } catch (Exception e) {

    }
}

2) Try this: https://github.com/sanathp/DatabaseManager_For_Android

How to insert a line break <br> in markdown

I know this post is about adding a single line break but I thought I would mention that you can create multiple line breaks with the backslash (\) character:

Hello
\
\
\
World!

This would result in 3 new lines after "Hello". To clarify, that would mean 2 empty lines between "Hello" and "World!". It would display like this:


Hello



World!



Personally I find this cleaner for a large number of line breaks compared to using <br>.

Note that backslashes are not recommended for compatibility reasons. So this may not be supported by your Markdown parser but it's handy when it is.

rsync: how can I configure it to create target directory on server?

this worked for me:

 rsync /dev/null node:existing-dir/new-dir/

I do get this message :

skipping non-regular file "null"

but I don't have to worry about having an empty directory hanging around.

Why is python setup.py saying invalid command 'bdist_wheel' on Travis CI?

If you already have all the required modules installed you probably need to import the setuptools module in your setup.py file. So just add the following line at the leading of setup.py file.

import setuptools
from distutils.core import setup
# other imports and setups

This is also mentioned in wheel's documentation. https://wheel.readthedocs.io/en/stable/#usage

How to align 3 divs (left/center/right) inside another div?

The easiest solution is to crate a table with 3 columns and center that table.

html:

 <div id="cont">
        <table class="aa">
            <tr>
                <td>
                    <div id="left">
                        <h3 class="hh">Content1</h3>
                        </div>
                    </td>
                <td>
                    <div id="center">
                        <h3 class="hh">Content2</h3>
                        </div>
                 </td>
                <td>
                    <div id="right"><h3 class="hh">Content3</h3>
                        </div>
                </td>
            </tr>
        </table>
    </div>

css:

#cont 
{
  margin: 0px auto;    
  padding: 10px 10px;
}

#left
{    
  width: 200px;
  height: 160px;
  border: 5px solid #fff;
}

#center
{
  width: 200px;
  height: 160px;
  border: 5px solid #fff;
}

#right
{
  width: 200px;
  height: 160px;
  border: 5px solid #fff;
}

missing private key in the distribution certificate on keychain

I could resolve this problem by updating macOS and XCode.

Resolving MSB3247 - Found conflicts between different versions of the same dependent assembly

This warning generated for default ASP.NET MVC 4 beta see here

In, any cast this Warning can be eliminated by manually editing the .csproj file for your project.

modify........: Reference Include="System.Net.Http"

to read ......: Reference Include="System.Net.Http, Version=4.0.0.0"

Changing Jenkins build number

You can change build number by updating file ${JENKINS_HOME}/jobs/job_name/nextBuildNumber on Jenkins server.

You can also install plugin Next Build Number plugin to change build number using CLI or UI

How to query nested objects?

db.messages.find( { headers : { From: "[email protected]" } } )

This queries for documents where headers equals { From: ... }, i.e. contains no other fields.


db.messages.find( { 'headers.From': "[email protected]" } )

This only looks at the headers.From field, not affected by other fields contained in, or missing from, headers.


Dot-notation docs

scp or sftp copy multiple files with single command

Is more simple without using scp:

tar cf - file1 ... file_n | ssh user@server 'tar xf -'

This also let you do some things like compress the stream (-C) or (since OpenSSH v7.3) -J any times to jump through one (or more) proxy servers.

You can avoid using passwords coping your public key to ~/.ssh/authorized_keys with ssh-copy-id.

Posted also here (with more details) and here.

Permission denied (publickey) when SSH Access to Amazon EC2 instance

When you try doing

ssh -i <.pem path> root@ec2-public-dns

You get a message advising you to use the ec2-user.

Please login as the user "ec2-user" rather than the user "root".

So use

ssh -i <.pem path> ec2-user@ec2-public-dns

Java ArrayList copy

Java doesn't pass objects, it passes references (pointers) to objects. So yes, l2 and l1 are two pointers to the same object.

You have to make an explicit copy if you need two different list with the same contents.

Can someone give an example of cosine similarity, in a very simple, graphical way?

Here's my implementation in C#.

using System;

namespace CosineSimilarity
{
    class Program
    {
        static void Main()
        {
            int[] vecA = {1, 2, 3, 4, 5};
            int[] vecB = {6, 7, 7, 9, 10};

            var cosSimilarity = CalculateCosineSimilarity(vecA, vecB);

            Console.WriteLine(cosSimilarity);
            Console.Read();
        }

        private static double CalculateCosineSimilarity(int[] vecA, int[] vecB)
        {
            var dotProduct = DotProduct(vecA, vecB);
            var magnitudeOfA = Magnitude(vecA);
            var magnitudeOfB = Magnitude(vecB);

            return dotProduct/(magnitudeOfA*magnitudeOfB);
        }

        private static double DotProduct(int[] vecA, int[] vecB)
        {
            // I'm not validating inputs here for simplicity.            
            double dotProduct = 0;
            for (var i = 0; i < vecA.Length; i++)
            {
                dotProduct += (vecA[i] * vecB[i]);
            }

            return dotProduct;
        }

        // Magnitude of the vector is the square root of the dot product of the vector with itself.
        private static double Magnitude(int[] vector)
        {
            return Math.Sqrt(DotProduct(vector, vector));
        }
    }
}

How do I use shell variables in an awk script?

Getting shell variables into awk

may be done in several ways. Some are better than others. This should cover most of them. If you have a comment, please leave below.                                                                                    v1.5


Using -v (The best way, most portable)

Use the -v option: (P.S. use a space after -v or it will be less portable. E.g., awk -v var= not awk -vvar=)

variable="line one\nline two"
awk -v var="$variable" 'BEGIN {print var}'
line one
line two

This should be compatible with most awk, and the variable is available in the BEGIN block as well:

If you have multiple variables:

awk -v a="$var1" -v b="$var2" 'BEGIN {print a,b}'

Warning. As Ed Morton writes, escape sequences will be interpreted so \t becomes a real tab and not \t if that is what you search for. Can be solved by using ENVIRON[] or access it via ARGV[]

PS If you like three vertical bar as separator |||, it can't be escaped, so use -F"[|][|][|]"

Example on getting data from a program/function inn to awk (here date is used)

awk -v time="$(date +"%F %H:%M" -d '-1 minute')" 'BEGIN {print time}'

Variable after code block

Here we get the variable after the awk code. This will work fine as long as you do not need the variable in the BEGIN block:

variable="line one\nline two"
echo "input data" | awk '{print var}' var="${variable}"
or
awk '{print var}' var="${variable}" file
  • Adding multiple variables:

awk '{print a,b,$0}' a="$var1" b="$var2" file

  • In this way we can also set different Field Separator FS for each file.

awk 'some code' FS=',' file1.txt FS=';' file2.ext

  • Variable after the code block will not work for the BEGIN block:

echo "input data" | awk 'BEGIN {print var}' var="${variable}"


Here-string

Variable can also be added to awk using a here-string from shells that support them (including Bash):

awk '{print $0}' <<< "$variable"
test

This is the same as:

printf '%s' "$variable" | awk '{print $0}'

P.S. this treats the variable as a file input.


ENVIRON input

As TrueY writes, you can use the ENVIRON to print Environment Variables. Setting a variable before running AWK, you can print it out like this:

X=MyVar
awk 'BEGIN{print ENVIRON["X"],ENVIRON["SHELL"]}'
MyVar /bin/bash

ARGV input

As Steven Penny writes, you can use ARGV to get the data into awk:

v="my data"
awk 'BEGIN {print ARGV[1]}' "$v"
my data

To get the data into the code itself, not just the BEGIN:

v="my data"
echo "test" | awk 'BEGIN{var=ARGV[1];ARGV[1]=""} {print var, $0}' "$v"
my data test

Variable within the code: USE WITH CAUTION

You can use a variable within the awk code, but it's messy and hard to read, and as Charles Duffy points out, this version may also be a victim of code injection. If someone adds bad stuff to the variable, it will be executed as part of the awk code.

This works by extracting the variable within the code, so it becomes a part of it.

If you want to make an awk that changes dynamically with use of variables, you can do it this way, but DO NOT use it for normal variables.

variable="line one\nline two"
awk 'BEGIN {print "'"$variable"'"}'
line one
line two

Here is an example of code injection:

variable='line one\nline two" ; for (i=1;i<=1000;++i) print i"'
awk 'BEGIN {print "'"$variable"'"}'
line one
line two
1
2
3
.
.
1000

You can add lots of commands to awk this way. Even make it crash with non valid commands.


Extra info:

Use of double quote

It's always good to double quote variable "$variable"
If not, multiple lines will be added as a long single line.

Example:

var="Line one
This is line two"

echo $var
Line one This is line two

echo "$var"
Line one
This is line two

Other errors you can get without double quote:

variable="line one\nline two"
awk -v var=$variable 'BEGIN {print var}'
awk: cmd. line:1: one\nline
awk: cmd. line:1:    ^ backslash not last character on line
awk: cmd. line:1: one\nline
awk: cmd. line:1:    ^ syntax error

And with single quote, it does not expand the value of the variable:

awk -v var='$variable' 'BEGIN {print var}'
$variable

More info about AWK and variables

Read this faq.

Your project contains error(s), please fix it before running it

If none of the above solution work, you should check the READ ONLY property of the Project folder, if it is Read-Only, the compiler will not be able to overwrite the resources, R.java and other dex APK etc files and hence this will occur.. This happened to me and I fixed after a long struggle.. Happy Programming.

How do you enable mod_rewrite on any OS?

network solutions offers the advice to put a php.ini in the cgi-bin to enable mod_rewrite

How to detect responsive breakpoints of Twitter Bootstrap 3 using JavaScript?

It's been a while since the OP, but here's my solution for this using Bootstrap 3. In my use case, I was only targeting rows, but the same could be applied to the container, etc.

Just change .row to whatever you want.

jQuery(document).ready(function ($) {

    var alterClass = function () {

        var ww = document.body.clientWidth;

        if (ww < 768) {

            $('.row').addClass('is-xs').removeClass('is-sm').removeClass('is-lg').removeClass('is-md');

        } else if (ww >= 768 && ww < 992) {

            $('.row').addClass('is-sm').removeClass('is-xs').removeClass('is-lg').removeClass('is-md');

        } else if (ww >= 992 && ww < 1200) {

            $('.row').addClass('is-md').removeClass('is-xs').removeClass('is-lg').removeClass('is-sm');

        } else if (ww >= 1200) {

            $('.row').addClass('is-lg').removeClass('is-md').removeClass('is-sm').removeClass('is-xs');

        };
    };

    // Make Changes when the window is resized
    $(window).resize(function () {
        alterClass();
    });

    // Fire when the page first loads
    alterClass();
});

How to change Git log date formats

In addition to --date=(relative|local|default|iso|iso-strict|rfc|short|raw), as others have mentioned, you can also use a custom log date format with

--date=format:'%Y-%m-%d %H:%M:%S'

This outputs something like 2016-01-13 11:32:13.

NOTE: If you take a look at the commit linked to below, I believe you'll need at least Git v2.6.0-rc0 for this to work.

In a full command it would be something like:

git config --global alias.lg "log --graph --decorate 
-30 --all --date-order --date=format:'%Y-%m-%d %H:%M:%S' 
--pretty=format:'%C(cyan)%h%Creset %C(black bold)%ad%Creset%C(auto)%d %s'" 

I haven't been able to find this in documentation anywhere (if someone knows where to find it, please comment) so I originally found the placeholders by trial and error.

In my search for documentation on this I found a commit to Git itself that indicates the format is fed directly to strftime. Looking up strftime (here or here) the placeholders I found match the placeholders listed.

The placeholders include:

%a      Abbreviated weekday name
%A      Full weekday name
%b      Abbreviated month name
%B      Full month name
%c      Date and time representation appropriate for locale
%d      Day of month as decimal number (01 – 31)
%H      Hour in 24-hour format (00 – 23)
%I      Hour in 12-hour format (01 – 12)
%j      Day of year as decimal number (001 – 366)
%m      Month as decimal number (01 – 12)
%M      Minute as decimal number (00 – 59)
%p      Current locale's A.M./P.M. indicator for 12-hour clock
%S      Second as decimal number (00 – 59)
%U      Week of year as decimal number, with Sunday as first day of week (00 – 53)
%w      Weekday as decimal number (0 – 6; Sunday is 0)
%W      Week of year as decimal number, with Monday as first day of week (00 – 53)
%x      Date representation for current locale
%X      Time representation for current locale
%y      Year without century, as decimal number (00 – 99)
%Y      Year with century, as decimal number
%z, %Z  Either the time-zone name or time zone abbreviation, depending on registry settings
%%      Percent sign

In a full command it would be something like

git config --global alias.lg "log --graph --decorate -30 --all --date-order --date=format:'%Y-%m-%d %H:%M:%S' --pretty=format:'%C(cyan)%h%Creset %C(black bold)%ad%Creset%C(auto)%d %s'" 

bash assign default value

The default value parameter expansion is often useful in build scripts like the example one below. If the user just calls the script as-is, perl will not be built in. The user has to explicitly set WITH_PERL to a value other than "no" to have it built in.

$ cat defvar.sh
#!/bin/bash

WITH_PERL=${WITH_PERL:-no}

if [[ "$WITH_PERL" != no ]]; then
    echo "building with perl"
    # ./configure --enable=perl
else
    echo "not building with perl"
    # ./configure
fi

Build without Perl

$ ./defvar.sh
not building with perl

Build with Perl

$ WITH_PERL=yes ./defvar.sh
building with perl

How do I automatically update a timestamp in PostgreSQL

Updating timestamp, only if the values changed

Based on E.J's link and add a if statement from this link (https://stackoverflow.com/a/3084254/1526023)

CREATE OR REPLACE FUNCTION update_modified_column()
RETURNS TRIGGER AS $$
BEGIN
   IF row(NEW.*) IS DISTINCT FROM row(OLD.*) THEN
      NEW.modified = now(); 
      RETURN NEW;
   ELSE
      RETURN OLD;
   END IF;
END;
$$ language 'plpgsql';

Select info from table where row has max date

SELECT group,MAX(date) as max_date
FROM table
WHERE checks>0
GROUP BY group

That works to get the max date..join it back to your data to get the other columns:

Select group,max_date,checks
from table t
inner join 
(SELECT group,MAX(date) as max_date
FROM table
WHERE checks>0
GROUP BY group)a
on a.group = t.group and a.max_date = date

Inner join functions as the filter to get the max record only.

FYI, your column names are horrid, don't use reserved words for columns (group, date, table).

How to create a directory and give permission in single command

IMO, it's better to use the install command in such situations. I was trying to make systemd-journald persistent across reboots.

install -d  -g systemd-journal -m 2755 -v /var/log/journal

Using command line arguments in VBscript

Set args = Wscript.Arguments

For Each arg In args
  Wscript.Echo arg
Next

From a command prompt, run the script like this:

CSCRIPT MyScript.vbs 1 2 A B "Arg with spaces"

Will give results like this:

1
2
A
B
Arg with spaces

How do I put a border around an Android textview?

This may help you.

<RelativeLayout
    android:id="@+id/textbox"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:background="@android:color/darker_gray" >

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:layout_margin="3dp"
        android:background="@android:color/white"
        android:gravity="center"
        android:text="@string/app_name"
        android:textSize="20dp" />

</RelativeLayout

Input from the keyboard in command line application

I just wanted to comment (I have not enough reps) on xenadu's implementation, because CChar in OS X is Int8, and Swift does not like at all when you add to the array when getchar() returns parts of UTF-8, or anything else above 7 bit.

I am using an array of UInt8 instead, and it works great and String.fromCString converts the UInt8 into UTF-8 just fine.

However this is how I done it

func readln() -> (str: String?, hadError: Bool) {
    var cstr: [UInt8] = []
    var c: Int32 = 0
    while c != EOF {
        c = getchar()
        if (c == 10 || c == 13) || c > 255 { break }
        cstr.append(UInt8(c))
    }
    cstr.append(0)
    return String.fromCStringRepairingIllFormedUTF8(UnsafePointer<CChar>(cstr))
}

while true {
    if let mystring = readln().str {
        println(" > \(mystring)")
    }
}

Groovy String to Date

Googling around for Groovy ways to "cast" a String to a Date, I came across this article: http://www.goodercode.com/wp/intercept-method-calls-groovy-type-conversion/

The author uses Groovy metaMethods to allow dynamically extending the behavior of any class' asType method. Here is the code from the website.

class Convert {
    private from
    private to

    private Convert(clazz) { from = clazz }
    static def from(clazz) {
        new Convert(clazz)
    }

    def to(clazz) {
        to = clazz
        return this
    }

    def using(closure) {
        def originalAsType = from.metaClass.getMetaMethod('asType', [] as Class[])
        from.metaClass.asType = { Class clazz ->
            if( clazz == to ) {
                closure.setProperty('value', delegate)
                closure(delegate)
            } else {
                originalAsType.doMethodInvoke(delegate, clazz)
            }
        }
    }
}

They provide a Convert class that wraps the Groovy complexity, making it trivial to add custom as-based type conversion from any type to any other:

Convert.from( String ).to( Date ).using { new java.text.SimpleDateFormat('MM-dd-yyyy').parse(value) }

def christmas = '12-25-2010' as Date

It's a convenient and powerful solution, but I wouldn't recommend it to someone who isn't familiar with the tradeoffs and pitfalls of tinkering with metaClasses.

How to declare an array of objects in C#

You are creating an array of null references. You should do something like:

for (int i = 0; i < houses.Count; i++)
{
    houses[i] = new GameObject();
}

Load local HTML file in a C# WebBrowser

Windows 10 uwp application.

Try this:

webview.Navigate(new Uri("ms-appx-web:///index.html"));

Graphical user interface Tutorial in C

You can also have a look at FLTK (C++ and not plain C though)

FLTK (pronounced "fulltick") is a cross-platform C++ GUI toolkit for UNIX®/Linux® (X11), Microsoft® Windows®, and MacOS® X. FLTK provides modern GUI functionality without the bloat and supports 3D graphics via OpenGL® and its built-in GLUT emulation.

FLTK is designed to be small and modular enough to be statically linked, but works fine as a shared library. FLTK also includes an excellent UI builder called FLUID that can be used to create applications in minutes.

Here are some quickstart screencasts

[Happy New Year!]

How to use dashes in HTML-5 data-* attributes in ASP.NET MVC

It's even easier than everything suggested above. Data attributes in MVC which include dashes (-) are catered for with the use of underscore (_).

<%= Html.ActionLink("« Previous", "Search",
 new { keyword = Model.Keyword, page = Model.currPage - 1},
 new { @class = "prev", data_details = "Some Details"   })%>

I see JohnnyO already mentioned this.

Base table or view not found: 1146 Table Laravel 5

If your error is not related to the issue of

Laravel can't determine the plural form of the word you used for your table name.

with this solution

and still have this error, try my approach. you should find the problem in the default "AppServiceProvider.php" or other ServiceProviders defined for that application specifically or even in Kernel.php in App\Console

This error happened for me and I solved it temporary and still couldn't figure out the exact origin and description.

In my case the main problem for causing my table unable to migrate, is that I have running code/query on my "PermissionsServiceProvider.php" in the boot() method.

In the same way, maybe, you defined something in boot() method of AppServiceProvider.php or in the Kernel.php

So first check your Serviceproviders and disable code for a while, and run php artisan migrate and then undo changes in your code.

How to get the current date and time

Java has always got inadequate support for the date and time use cases. For example, the existing classes (such as java.util.Date and SimpleDateFormatter) aren’t thread-safe which can lead to concurrency issues. Also there are certain flaws in API. For example, years in java.util.Date start at 1900, months start at 1, and days start at 0—not very intuitive. These issues led to popularity of third-party date and time libraries, such as Joda-Time. To address a new date and time API is designed for Java SE 8.

LocalDateTime timePoint = LocalDateTime.now();
System.out.println(timePoint);

As per doc:

The method now() returns the current date-time using the system clock and default time-zone, not null. It obtains the current date-time from the system clock in the default time-zone. This will query the system clock in the default time-zone to obtain the current date-time. Using this method will prevent the ability to use an alternate clock for testing because the clock is hard-coded.

What does the "assert" keyword do?

assert is a debugging tool that will cause the program to throw an AssertionFailed exception if the condition is not true. In this case, the program will throw an exception if either of the two conditions following it evaluate to false. Generally speaking, assert should not be used in production code

How to prevent robots from automatically filling up a form?

How about creating a text field input box the same color as the background which must remain blank. This will get around the problem of a bot reading display:none

OS detecting makefile

The uname command (http://developer.apple.com/documentation/Darwin/Reference/ManPages/man1/uname.1.html) with no parameters should tell you the operating system name. I'd use that, then make conditionals based on the return value.

Example

UNAME := $(shell uname)

ifeq ($(UNAME), Linux)
# do something Linux-y
endif
ifeq ($(UNAME), Solaris)
# do something Solaris-y
endif

Initialization of an ArrayList in one line

Java 9 has the following method to create an immutable list:

List<String> places = List.of("Buenos Aires", "Córdoba", "La Plata");

which is easily adapted to create a mutable list, if required:

List<String> places = new ArrayList<>(List.of("Buenos Aires", "Córdoba", "La Plata"));

Similar methods are available for Set and Map.

How do I handle ImeOptions' done button click?

Thanks to chikka.anddev and Alex Cohn in Kotlin it is:

text.setOnEditorActionListener { v, actionId, event ->
    if (actionId == EditorInfo.IME_ACTION_DONE ||
        event?.action == KeyEvent.ACTION_DOWN && event.keyCode == KeyEvent.KEYCODE_ENTER) {
        doSomething()
        true
    } else {
        false
    }
}

Here I check for Enter key, because it returns EditorInfo.IME_NULL instead of IME_ACTION_DONE.

See also Android imeOptions="actionDone" not working. Add android:singleLine="true" in the EditText.

How do I change the background color with JavaScript?

You can change background of a page by simply using:

function changeBodyBg(color){
    document.body.style.background = color;
}

Read more @ Changing the Background Color

How to get GET (query string) variables in Express.js on Node.js?

app.get('/user/:id', function(req, res) {
    res.send('user' + req.params.id);    
});

You can use this or you can try body-parser for parsing special element from the request parameters.

HTML Input Box - Disable

<input type="text" required="true" value="" readonly>

Not the.

<input type="text" required="true" value="" readonly="true">

How to delete files recursively from an S3 bucket

I needed to do the following...

def delete_bucket
  s3 = init_amazon_s3
  s3.buckets['BUCKET-NAME'].objects.each do |obj|
    obj.delete
  end
end

def init_amazon_s3
  config = YAML.load_file("#{Rails.root}/config/s3.yml")
  AWS.config(:access_key_id => config['access_key_id'],:secret_access_key => config['secret_access_key'])
  s3 = AWS::S3.new
end

How to convert a String to JsonObject using gson library

Note that as of Gson 2.8.6, instance method JsonParser.parse has been deprecated and replaced by static method JsonParser.parseString:

JsonObject jsonObject = JsonParser.parseString(json).getAsJsonObject();

Checking for duplicate strings in JavaScript array

You could take a Set and filter the values who are alreday seen.

_x000D_
_x000D_
var array = ["q", "w", "w", "e", "i", "u", "r"],_x000D_
    seen = array.filter((s => v => s.has(v) || !s.add(v))(new Set));_x000D_
_x000D_
console.log(seen);
_x000D_
_x000D_
_x000D_

Get a list of distinct values in List

public class KeyNote
{
    public long KeyNoteId { get; set; }
    public long CourseId { get; set; }
    public string CourseName { get; set; }
    public string Note { get; set; }
    public DateTime CreatedDate { get; set; }
}

public List<KeyNote> KeyNotes { get; set; }
public List<RefCourse> GetCourses { get; set; }    

List<RefCourse> courses = KeyNotes.Select(x => new RefCourse { CourseId = x.CourseId, Name = x.CourseName }).Distinct().ToList();

By using the above logic, we can get the unique Courses.

Creating a script for a Telnet session?

I like the example given by Active State using python. Here is the full link. I added the simple log in part from the link but you can get the gist of what you could do.

import telnetlib

prdLogBox='142.178.1.3'
uid = 'uid'
pwd = 'yourpassword'

tn = telnetlib.Telnet(prdLogBox)
tn.read_until("login: ")
tn.write(uid + "\n")
tn.read_until("Password:")
tn.write(pwd + "\n")
tn.write("exit\n")
tn.close()

How to perform a for-each loop over all the files under a specified path?

Here is a better way to loop over files as it handles spaces and newlines in file names:

#!/bin/bash

find . -type f -iname "*.txt" -print0 | while IFS= read -r -d $'\0' line; do
    echo "$line"
    ls -l "$line"    
done

Add multiple items to a list

Code check:

This is offtopic here but the people over at CodeReview are more than happy to help you.

I strongly suggest you to do so, there are several things that need attention in your code. Likewise I suggest that you do start reading tutorials since there is really no good reason not to do so.

Lists:

As you said yourself: you need a list of items. The way it is now you only store a reference to one item. Lucky there is exactly that to hold a group of related objects: a List.

Lists are very straightforward to use but take a look at the related documentation anyway.

A very simple example to keep multiple bikes in a list:

List<Motorbike> bikes = new List<Motorbike>();

bikes.add(new Bike { make = "Honda", color = "brown" });
bikes.add(new Bike { make = "Vroom", color = "red" });

And to iterate over the list you can use the foreach statement:

foreach(var bike in bikes) {
     Console.WriteLine(bike.make);
}

C++ Redefinition Header Files (winsock2.h)

#pragma once is flakey, even on MS compilers, and is not supported by many other compilers. As many other people have mentioned, using include guards is the way to go. Don't use #pragma once at all - it'll make your life much easier.

Simple CSS Animation Loop – Fading In & Out "Loading" Text

As King King said, you must add the browser specific prefix. This should cover most browsers:

_x000D_
_x000D_
@keyframes flickerAnimation {_x000D_
  0%   { opacity:1; }_x000D_
  50%  { opacity:0; }_x000D_
  100% { opacity:1; }_x000D_
}_x000D_
@-o-keyframes flickerAnimation{_x000D_
  0%   { opacity:1; }_x000D_
  50%  { opacity:0; }_x000D_
  100% { opacity:1; }_x000D_
}_x000D_
@-moz-keyframes flickerAnimation{_x000D_
  0%   { opacity:1; }_x000D_
  50%  { opacity:0; }_x000D_
  100% { opacity:1; }_x000D_
}_x000D_
@-webkit-keyframes flickerAnimation{_x000D_
  0%   { opacity:1; }_x000D_
  50%  { opacity:0; }_x000D_
  100% { opacity:1; }_x000D_
}_x000D_
.animate-flicker {_x000D_
   -webkit-animation: flickerAnimation 1s infinite;_x000D_
   -moz-animation: flickerAnimation 1s infinite;_x000D_
   -o-animation: flickerAnimation 1s infinite;_x000D_
    animation: flickerAnimation 1s infinite;_x000D_
}
_x000D_
<div class="animate-flicker">Loading...</div>
_x000D_
_x000D_
_x000D_

is vs typeof

This should answer that question, and then some.

The second line, if (obj.GetType() == typeof(ClassA)) {}, is faster, for those that don't want to read the article.

(Be aware that they don't do the same thing)

Make <body> fill entire screen?

If you have a border or padding, then the solution

_x000D_
_x000D_
html, body {_x000D_
    margin: 0;_x000D_
    height: 100%;_x000D_
}_x000D_
body {_x000D_
    border: solid red 5px;_x000D_
    border-radius: 2em;_x000D_
}
_x000D_
_x000D_
_x000D_

produces the imperfect rendering

not good

To get it right in the presence of a border or padding

good

use instead

_x000D_
_x000D_
html, body {_x000D_
    margin: 0;_x000D_
    height: 100%;_x000D_
}_x000D_
body {_x000D_
    box-sizing: border-box;_x000D_
    border: solid red 5px;_x000D_
    border-radius: 2em;_x000D_
}
_x000D_
_x000D_
_x000D_

as Martin pointed out, although overflow: hidden is not needed.

(2018 - tested with Chrome 69 and IE 11)

How can I get the latest JRE / JDK as a zip file rather than EXE or MSI installer?

Commands from tips below wrapped as batch script. Save this as unpack.bat. Then place it to dir with jdk/jre extracted files.

@echo off

cd /d "%~dp0"
for /r %%x in (*.pack) do .\bin\unpack200 -r "%%x" "%%~dx%%~px%%~nx.jar"

How to get response body using HttpURLConnection, when code other than 2xx is returned?

This is an easy way to get a successful response from the server like PHP echo otherwise an error message.

BufferedReader br = null;
if (conn.getResponseCode() == 200) {
    br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
    String strCurrentLine;
        while ((strCurrentLine = br.readLine()) != null) {
               System.out.println(strCurrentLine);
        }
} else {
    br = new BufferedReader(new InputStreamReader(conn.getErrorStream()));
    String strCurrentLine;
        while ((strCurrentLine = br.readLine()) != null) {
               System.out.println(strCurrentLine);
        }
}

How to use LDFLAGS in makefile

In more complicated build scenarios, it is common to break compilation into stages, with compilation and assembly happening first (output to object files), and linking object files into a final executable or library afterward--this prevents having to recompile all object files when their source files haven't changed. That's why including the linking flag -lm isn't working when you put it in CFLAGS (CFLAGS is used in the compilation stage).

The convention for libraries to be linked is to place them in either LOADLIBES or LDLIBS (GNU make includes both, but your mileage may vary):

LDLIBS=-lm

This should allow you to continue using the built-in rules rather than having to write your own linking rule. For other makes, there should be a flag to output built-in rules (for GNU make, this is -p). If your version of make does not have a built-in rule for linking (or if it does not have a placeholder for -l directives), you'll need to write your own:

client.o: client.c
    $(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c -o $@ $<

client: client.o
    $(CC) $(LDFLAGS) $(TARGET_ARCH) $^ $(LOADLIBES) $(LDLIBS) -o $@

curl_init() function not working

For linux you can install it via

sudo apt-get install php5-curl

For Windows(removing the ;) from php.ini

;extension=php_curl.dll

Restart apache server.

Can't connect Nexus 4 to adb: unauthorized

I was facing same, issue, I found I was using a simple usb cable which was meant for only charge and not data copy. using good usb cable solved my problem !

PHP server on local machine?

AppServ is a small program in Windows to run:

  • Apache
  • PHP
  • MySQL
  • phpMyAdmin

It will also give you a startup and stop button for Apache. Which I find very useful.

git add only modified changes and ignore untracked files

You didn't say what's currently your .gitignore, but a .gitignore with the following contents in your root directory should do the trick.

.metadata
build

Is <img> element block level or inline level?

behaves as an inline-block element as it allows other images in same line i.e. inline and also we can change the width and height of the image and this is the property of a block element. Hence, provide both the features of inline and block elements.

How to loop through array in jQuery?

ES6 syntax with arrow function and interpolation:

var data=["a","b","c"];
$(data).each((index, element) => {
        console.log(`current index : ${index} element : ${element}`)
    });

How to truncate milliseconds off of a .NET DateTime

DateTime d = DateTime.Now;
d = d.AddMilliseconds(-d.Millisecond);

Declaring and initializing arrays in C

There is no such particular way in which you can initialize the array after declaring it once.

There are three options only:

1.) initialize them in different lines :

int array[SIZE];

array[0] = 1;
array[1] = 2;
array[2] = 3;
array[3] = 4;
//...
//...
//...

But thats not what you want i guess.

2.) Initialize them using a for or while loop:

for (i = 0; i < MAX ; i++)  {
    array[i] = i;
}

This is the BEST WAY by the way to achieve your goal.

3.) In case your requirement is to initialize the array in one line itself, you have to define at-least an array with initialization. And then copy it to your destination array, but I think that there is no benefit of doing so, in that case you should define and initialize your array in one line itself.

And can I ask you why specifically you want to do so???

How do I set the request timeout for one controller action in an asp.net mvc application

<location path="ControllerName/ActionName">
    <system.web>
        <httpRuntime executionTimeout="1000"/>
    </system.web>
</location>

Probably it is better to set such values in web.config instead of controller. Hardcoding of configurable options is considered harmful.

Find and kill a process in one line using bash and regex

One liner:

ps aux | grep -i csp_build | awk '{print $2}' | xargs sudo kill -9

  • Print out column 2: awk '{print $2}'
  • sudo is optional
  • Run kill -9 5124, kill -9 5373 etc (kill -15 is more graceful but slightly slower)

Bonus:

I also have 2 shortcut functions defined in my .bash_profile (~/.bash_profile is for osx, you have to see what works for your *nix machine).

  1. p keyword
    • lists out all Processes containing keyword
    • usage e.g: p csp_build , p python etc

bash_profile code:

# FIND PROCESS
function p(){
        ps aux | grep -i $1 | grep -v grep
}
  1. ka keyword
    • Kills All processes that have this keyword
    • usage e.g: ka csp_build , ka python etc
    • optional kill level e.g: ka csp_build 15, ka python 9

bash_profile code:

# KILL ALL
function ka(){

    cnt=$( p $1 | wc -l)  # total count of processes found
    klevel=${2:-15}       # kill level, defaults to 15 if argument 2 is empty

    echo -e "\nSearching for '$1' -- Found" $cnt "Running Processes .. "
    p $1

    echo -e '\nTerminating' $cnt 'processes .. '

    ps aux  |  grep -i $1 |  grep -v grep   | awk '{print $2}' | xargs sudo kill -klevel
    echo -e "Done!\n"

    echo "Running search again:"
    p "$1"
    echo -e "\n"
}

Can I have multiple Xcode versions installed?

Whatever advice path you go down, make a copy of your project folder, and rename the external most one to reflect what XCode version it is being opened in. Your choice on whether you want it to update syntax or not, but the main reason for all this bovver is your storyboard will be altered just by looking. It may be resolved by the time a new reader coming across this in the future, or

Java equivalent to Explode and Implode(PHP)

The Javadoc for String reveals that String.split() is what you're looking for in regard to explode.

Java does not include a "implode" of "join" equivalent. Rather than including a giant external dependency for a simple function as the other answers suggest, you may just want to write a couple lines of code. There's a number of ways to accomplish that; using a StringBuilder is one:

String foo = "This,that,other";
String[] split = foo.split(",");
StringBuilder sb = new StringBuilder();
for (int i = 0; i < split.length; i++) {
    sb.append(split[i]);
    if (i != split.length - 1) {
        sb.append(" ");
    }
}
String joined = sb.toString();

Folder structure for a Node.js project

It's important to note that there's no consensus on what's the best approach and related frameworks in general do not enforce nor reward certain structures.

I find this to be a frustrating and huge overhead but equally important. It is sort of a downplayed version (but IMO more important) of the style guide issue. I like to point this out because the answer is the same: it doesn't matter what structure you use as long as it's well defined and coherent.

So I'd propose to look for a comprehensive guide that you like and make it clear that the project is based on this.

It's not easy, especially if you're new to this! Expect to spend hours researching. You'll find most guides recommending an MVC-like structure. While several years ago that might have been a solid choice, nowadays that's not necessarily the case. For example here's another approach.

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

For iPhone Devices : Now we need only one size iPhone 6 Plus (5.5 Inch) • 1242 x 2208 Then we have check box there, in all other sizes to : Use 5.5-Inch Display

ReactJS SyntheticEvent stopPropagation() only works with React events?

React 17 delegates events to root instead of document, which might solve the problem. More details here.

Difference between Parameters.Add(string, object) and Parameters.AddWithValue

Without explicitly providing the type as in command.Parameters.Add("@ID", SqlDbType.Int);, it will try to implicitly convert the input to what it is expecting.

The downside of this, is that the implicit conversion may not be the most optimal of conversions and may cause a performance hit.

There is a discussion about this very topic here: http://forums.asp.net/t/1200255.aspx/1

UITextField border color

this question shows up pretty high on a Google search and worked for the most part! I did find that Salman Zaidi's answer was partially correct for iOS 7.

You need to make a modification to the "reverting" code. I found that the following for reverting worked perfectly:

textField.layer.cornerRadius = 0.0f;
textField.layer.masksToBounds = YES;
textField.layer.borderColor = [[UIColor blackColor] CGColor];
textField.layer.borderWidth = 0.0f;

I understand that this is most likely due to changes in iOS 7.

SyntaxError: expected expression, got '<'

I got this type question on Django, and My issue is forget to add static to the <script> tag.

Such as in my template:

<script  type="text/javascript"  src="css/layer.js"></script>

I should add the static to it like this:

<script type="text/javascript" src="{% static 'css/layer.js' %}" ></script>

What is a good way to handle exceptions when trying to read a file in python?

Here is a read/write example. The with statements insure the close() statement will be called by the file object regardless of whether an exception is thrown. http://effbot.org/zone/python-with-statement.htm

import sys

fIn = 'symbolsIn.csv'
fOut = 'symbolsOut.csv'

try:
   with open(fIn, 'r') as f:
      file_content = f.read()
      print "read file " + fIn
   if not file_content:
      print "no data in file " + fIn
      file_content = "name,phone,address\n"
   with open(fOut, 'w') as dest:
      dest.write(file_content)
      print "wrote file " + fOut
except IOError as e:
   print "I/O error({0}): {1}".format(e.errno, e.strerror)
except: #handle other exceptions such as attribute errors
   print "Unexpected error:", sys.exc_info()[0]
print "done"

module.exports vs. export default in Node.js and ES6

The issue is with

  • how ES6 modules are emulated in CommonJS
  • how you import the module

ES6 to CommonJS

At the time of writing this, no environment supports ES6 modules natively. When using them in Node.js you need to use something like Babel to convert the modules to CommonJS. But how exactly does that happen?

Many people consider module.exports = ... to be equivalent to export default ... and exports.foo ... to be equivalent to export const foo = .... That's not quite true though, or at least not how Babel does it.

ES6 default exports are actually also named exports, except that default is a "reserved" name and there is special syntax support for it. Lets have a look how Babel compiles named and default exports:

// input
export const foo = 42;
export default 21;

// output
"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
var foo = exports.foo = 42;
exports.default = 21; 

Here we can see that the default export becomes a property on the exports object, just like foo.

Import the module

We can import the module in two ways: Either using CommonJS or using ES6 import syntax.

Your issue: I believe you are doing something like:

var bar = require('./input');
new bar();

expecting that bar is assigned the value of the default export. But as we can see in the example above, the default export is assigned to the default property!

So in order to access the default export we actually have to do

var bar = require('./input').default;

If we use ES6 module syntax, namely

import bar from './input';
console.log(bar);

Babel will transform it to

'use strict';

var _input = require('./input');

var _input2 = _interopRequireDefault(_input);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

console.log(_input2.default);

You can see that every access to bar is converted to access .default.

TS1086: An accessor cannot be declared in ambient context

I got the same issue when adding @angular/flex-layout to my Angular 8 project now with

`npm install @angular/flex-layout --save`.

This since now that command installed the major 9th version of the flex-layout package. Instead of upgrading everything else to the last version, I solved it by installing the last 8th major version of the package instead.

 npm install @angular/[email protected] --save

JQuery show/hide when hover

('.cat').hover(
  function () {
    $(this).show();
  }, 
  function () {
    $(this).hide();
  }
);

It's the same for the others.

For the smooth fade in you can use fadeIn and fadeOut

How to make a section of an image a clickable link

If you don't want to make the button a separate image, you can use the <area> tag. This is done by using html similar to this:

<img src="imgsrc" width="imgwidth" height="imgheight" alt="alttext" usemap="#mapname">

<map name="mapname">
    <area shape="rect" coords="see note 1" href="link" alt="alttext">
</map>

Note 1: The coords=" " attribute must be formatted in this way: coords="x1,y1,x2,y2" where:

x1=top left X coordinate
y1=top left Y coordinate
x2=bottom right X coordinate
y2=bottom right Y coordinate

Note 2: The usemap="#mapname" attribute must include the #.

EDIT:

I looked at your code and added in the <map> and <area> tags where they should be. I also commented out some parts that were either overlapping the image or seemed there for no use.

<div class="flexslider">
    <ul class="slides" runat="server" id="Ul">                             
        <li class="flex-active-slide" style="background: url(&quot;images/slider-bg-1.jpg&quot;) no-repeat scroll 50% 0px transparent; width: 100%; float: left; margin-right: -100%; position: relative; display: list-item;">
            <div class="container">
                <div class="sixteen columns contain"></div>   
                <img runat="server" id="imgSlide1" style="top: 1px; right: -19px; opacity: 1;" class="item" src="./test.png" data-topimage="7%" height="358" width="728" usemap="#imgmap" />
                <map name="imgmap">
                    <area shape="rect" coords="48,341,294,275" href="http://www.example.com/">
                </map>
                <!--<a href="#" style="display:block; background:#00F; width:356px; height:66px; position:absolute; left:1px; top:-19px; left: 162px; top: 279px;"></a>-->
            </div>
        </li>
    </ul>
</div>
<!-- <ul class="flex-direction-nav">
    <li><a class="flex-prev" href="#"><i class="icon-angle-left"></i></a></li>
    <li><a class="flex-next" href="#"><i class="icon-angle-right"></i></a></li>
</ul> -->

Notes:

  1. The coord="48,341,294,275" is in reference to your screenshot you posted.
  2. The src="./test.png" is the location and name of the screenshot you posted on my computer.
  3. The href="http://www.example.com/" is an example link.

Differences Between vbLf, vbCrLf & vbCr Constants

 Constant   Value               Description
 ----------------------------------------------------------------
 vbCr       Chr(13)             Carriage return
 vbCrLf     Chr(13) & Chr(10)   Carriage return–linefeed combination
 vbLf       Chr(10)             Line feed
  • vbCr : - return to line beginning
    Represents a carriage-return character for print and display functions.

  • vbCrLf : - similar to pressing Enter
    Represents a carriage-return character combined with a linefeed character for print and display functions.

  • vbLf : - go to next line
    Represents a linefeed character for print and display functions.


Read More from Constants Class

Align <div> elements side by side

Apply float:left; to both of your divs should make them stand side by side.

How to use placeholder as default value in select2 framework

$selectElement.select2({
    minimumResultsForSearch: -1,
    placeholder: 'SelectRelatives'}).on('select2-opening', function() {                                                                       $(this).closest('li').find('input').attr('placeholder','Select Relative');                            
});

React Native: How to select the next TextInput after pressing the "next" keyboard button?

Here a reagent solution for a input component that has a :focus property.

The field will be focused as long as this prop is set to true and will not have focus as long as this is false.

Unfortunately this component needs to have a :ref defined, I could not find an other way to call .focus() on it. I am happy about suggestions.

(defn focusable-input [init-attrs]
  (r/create-class
    {:display-name "focusable-input"
     :component-will-receive-props
       (fn [this new-argv]
         (let [ref-c (aget this "refs" (:ref init-attrs))
               focus (:focus (ru/extract-props new-argv))
               is-focused (.isFocused ref-c)]
           (if focus
             (when-not is-focused (.focus ref-c))
             (when is-focused (.blur ref-c)))))
     :reagent-render
       (fn [attrs]
         (let [init-focus (:focus init-attrs)
               auto-focus (or (:auto-focus attrs) init-focus)
               attrs (assoc attrs :auto-focus auto-focus)]
           [input attrs]))}))

https://gist.github.com/Knotschi/6f97efe89681ac149113ddec4c396cc5

How to put a symbol above another in LaTeX?

Use \overset{above}{main} in math mode. In your case, \overset{a}{\#}.

Auto Generate Database Diagram MySQL

Try MySQL Workbench, formerly DBDesigner 4:

http://dev.mysql.com/workbench/

This has a "Reverse Engineer Database" mode:

Database -> Reverse Engineer

enter image description here

Sheet.getRange(1,1,1,12) what does the numbers in bracket specify?

Found these docu on the google docu pages:

  • row --- int --- top row of the range
  • column --- int--- leftmost column of the range
  • optNumRows --- int --- number of rows in the range.
  • optNumColumns --- int --- number of columns in the range

In your example, you would get (if you picked the 3rd row) "C3:O3", cause C --> O is 12 columns

edit

Using the example on the docu:

// The code below will get the number of columns for the range C2:G8
// in the active spreadsheet, which happens to be "4"
var count = SpreadsheetApp.getActiveSheet().getRange(2, 3, 6, 4).getNumColumns(); Browser.msgBox(count);

The values between brackets:
2: the starting row = 2
3: the starting col = C
6: the number of rows = 6 so from 2 to 8
4: the number of cols = 4 so from C to G

So you come to the range: C2:G8

Spaces cause split in path with PowerShell

Using Powershell on Windows10 in 2018, what worked for me was simply to replace double quotes " by simple quotes '. Adding the backtick before the space, as suggested in an answer, broke the path.

Get string between two strings in a string

I think this works:

   static void Main(string[] args)
    {
        String text = "One=1,Two=2,ThreeFour=34";

        Console.WriteLine(betweenStrings(text, "One=", ",")); // 1
        Console.WriteLine(betweenStrings(text, "Two=", ",")); // 2
        Console.WriteLine(betweenStrings(text, "ThreeFour=", "")); // 34

        Console.ReadKey();

    }

    public static String betweenStrings(String text, String start, String end)
    {
        int p1 = text.IndexOf(start) + start.Length;
        int p2 = text.IndexOf(end, p1);

        if (end == "") return (text.Substring(p1));
        else return text.Substring(p1, p2 - p1);                      
    }

HTML5 Canvas: Zooming

If you have a source image or canvas element and your 400x400 canvas you want to draw into you can use the drawImage method to achieve zooming.

So for example, the full view might be like this

ctx.drawImage(img, 0, 0, img.width, img.height, 0, 0, canvas.width, canvas.height);

And a zoomed view might be like this

ctx.drawImage(img, img.width / 4, img.height / 4, img.width / 2, img.height / 2, 0, 0, canvas.width, canvas.height);

The first parameter to drawImage is the image element or canvas element to draw, the next 4 are the x, y, width and height to sample from the source and the last 4 parameters are the x, y, width and height of the region to draw in the canvas. It will then handle the scaling for you.

You would just need to pick the width and height for the source sample based on the zoom level and the x and y based on where the mouse is clicked minus half the calculated width and height (but you will need to ensure the rectangle isn't out of bounds).

How to declare an array in Python?

This is how:

my_array = [1, 'rebecca', 'allard', 15]

Java Timer vs ExecutorService?

If it's available to you, then it's difficult to think of a reason not to use the Java 5 executor framework. Calling:

ScheduledExecutorService ex = Executors.newSingleThreadScheduledExecutor();

will give you a ScheduledExecutorService with similar functionality to Timer (i.e. it will be single-threaded) but whose access may be slightly more scalable (under the hood, it uses concurrent structures rather than complete synchronization as with the Timer class). Using a ScheduledExecutorService also gives you advantages such as:

  • You can customize it if need be (see the newScheduledThreadPoolExecutor() or the ScheduledThreadPoolExecutor class)
  • The 'one off' executions can return results

About the only reasons for sticking to Timer I can think of are:

  • It is available pre Java 5
  • A similar class is provided in J2ME, which could make porting your application easier (but it wouldn't be terribly difficult to add a common layer of abstraction in this case)

Chrome:The website uses HSTS. Network errors...this page will probably work later

I encounter same error, and incognito mode also has same issue. I resolve this issue by clear Chrome history.

How do you create vectors with specific intervals in R?

Usually, we want to divide our vector into a number of intervals. In this case, you can use a function where (a) is a vector and (b) is the number of intervals. (Let's suppose you want 4 intervals)

a <- 1:10
b <- 4

FunctionIntervalM <- function(a,b) {
  seq(from=min(a), to = max(a), by = (max(a)-min(a))/b)
}

FunctionIntervalM(a,b)
# 1.00  3.25  5.50  7.75 10.00

Therefore you have 4 intervals:

1.00 - 3.25 
3.25 - 5.50
5.50 - 7.75
7.75 - 10.00

You can also use a cut function

  cut(a, 4)

# (0.991,3.25] (0.991,3.25] (0.991,3.25] (3.25,5.5]   (3.25,5.5]   (5.5,7.75]  
# (5.5,7.75]   (7.75,10]    (7.75,10]    (7.75,10]   
#Levels: (0.991,3.25] (3.25,5.5] (5.5,7.75] (7.75,10]

How to compare only date in moment.js

You could use startOf('day') method to compare just the date

Example :

var dateToCompare = moment("06/04/2015 18:30:00");
var today = moment(new Date());

dateToCompare.startOf('day').isSame(today.startOf('day'));

Adding IN clause List to a JPA Query

When using IN with a collection-valued parameter you don't need (...):

@NamedQuery(name = "EventLog.viewDatesInclude", 
    query = "SELECT el FROM EventLog el WHERE el.timeMark >= :dateFrom AND " 
    + "el.timeMark <= :dateTo AND " 
    + "el.name IN :inclList") 

Is it possible to run a .NET 4.5 app on XP?

I hesitate to post this answer, it is actually technically possible but it doesn't work that well in practice. The version numbers of the CLR and the core framework assemblies were not changed in 4.5. You still target v4.0.30319 of the CLR and the framework assembly version numbers are still 4.0.0.0. The only thing that's distinctive about the assembly manifest when you look at it with a disassembler like ildasm.exe is the presence of a [TargetFramework] attribute that says that 4.5 is needed, that would have to be altered. Not actually that easy, it is emitted by the compiler.

The biggest difference is not that visible, Microsoft made a long-overdue change in the executable header of the assemblies. Which specifies what version of Windows the executable is compatible with. XP belongs to a previous generation of Windows, started with Windows 2000. Their major version number is 5. Vista was the start of the current generation, major version number 6.

.NET compilers have always specified the minimum version number to be 4.00, the version of Windows NT and Windows 9x. You can see this by running dumpbin.exe /headers on the assembly. Sample output looks like this:

OPTIONAL HEADER VALUES
             10B magic # (PE32)
            ...
            4.00 operating system version
            0.00 image version
            4.00 subsystem version              // <=== here!!
               0 Win32 version
            ...

What's new in .NET 4.5 is that the compilers change that subsystem version to 6.00. A change that was over-due in large part because Windows pays attention to that number, beyond just checking if it is small enough. It also turns on appcompat features since it assumes that the program was written to work on old versions of Windows. These features cause trouble, particularly the way Windows lies about the size of a window in Aero is troublesome. It stops lying about the fat borders of an Aero window when it can see that the program was designed to run on a Windows version that has Aero.

You can alter that version number and set it back to 4.00 by running Editbin.exe on your assemblies with the /subsystem option. This answer shows a sample postbuild event.

That's however about where the good news ends, a significant problem is that .NET 4.5 isn't very compatible with .NET 4.0. By far the biggest hang-up is that classes were moved from one assembly to another. Most notably, that happened for the [Extension] attribute. Previously in System.Core.dll, it got moved to Mscorlib.dll in .NET 4.5. That's a kaboom on XP if you declare your own extension methods, your program says to look in Mscorlib for the attribute, enabled by a [TypeForwardedTo] attribute in the .NET 4.5 version of the System.Core reference assembly. But it isn't there when you run your program on .NET 4.0

And of course there's nothing that helps you stop using classes and methods that are only available on .NET 4.5. When you do, your program will fail with a TypeLoadException or MissingMethodException when run on 4.0

Just target 4.0 and all of these problems disappear. Or break that logjam and stop supporting XP, a business decision that programmers cannot often make but can certainly encourage by pointing out the hassles that it is causing. There is of course a non-zero cost to having to support ancient operating systems, just the testing effort is substantial. A cost that isn't often recognized by management, Windows compatibility is legendary, unless it is pointed out to them. Forward that cost to the client and they tend to make the right decision a lot quicker :) But we can't help you with that.

Bootstrap 3 - disable navbar collapse

The nabvar will collapse on small devices. The point of collapsing is defined by @grid-float-breakpoint in variables. By default this will by before 768px. For screens below the 768 pixels screen width, the navbar will look like:

enter image description here

It's possible to change the @grid-float-breakpoint in variables.less and recompile Bootstrap. When doing this you also will have to change @screen-xs-max in navbar.less. You will have to set this value to your new @grid-float-breakpoint -1. See also: https://github.com/twbs/bootstrap/pull/10465. This is needed to change navbar forms and dropdowns at the @grid-float-breakpoint to their mobile version too.

Easiest way is to customize bootstrap

find variable:

 @grid-float-breakpoint

which is set to @screen-sm, you can change it according to your needs. Hope it helps!


For SAAS Users

add your custom variables like $grid-float-breakpoint: 0px; before the @import "bootstrap.scss";

python: sys is not defined

In addition to the answers given above, check the last line of the error message in your console. In my case, the 'site-packages' path in sys.path.append('.....') was wrong.

How to print React component on click of a button?

If you're looking to print specific data that you already have access to, whether it's from a Store, AJAX, or available elsewhere, you can leverage my library react-print.

https://github.com/captray/react-print

It makes creating print templates much easier (assuming you already have a dependency on react). You just need to tag your HTML appropriately.

This ID should be added higher up in your actual DOM tree to exclude everything except the "print mount" below.

<div id="react-no-print"> 

This is where your react-print component will mount and wrap your template that you create:

<div id="print-mount"></div>

An example looks something like this:

var PrintTemplate = require('react-print');
var ReactDOM = require('react-dom');
var React = require('react');

var MyTemplate = React.createClass({
    render() {
        return (
            <PrintTemplate>
                <p>Your custom</p>
                <span>print stuff goes</span>
                <h1>Here</h1>
            </PrintTemplate>
        );
    }
});

ReactDOM.render(<MyTemplate/>, document.getElementById('print-mount'));

It's worth noting that you can create new or utilize existing child components inside of your template, and everything should render fine for printing.

Prepend line to beginning of a file

Different Idea:

(1) You save the original file as a variable.

(2) You overwrite the original file with new information.

(3) You append the original file in the data below the new information.

Code:

with open(<filename>,'r') as contents:
      save = contents.read()
with open(<filename>,'w') as contents:
      contents.write(< New Information >)
with open(<filename>,'a') as contents:
      contents.write(save)

fast way to copy formatting in excel

Just use the NumberFormat property after the Value property: In this example the Ranges are defined using variables called ColLetter and SheetRow and this comes from a for-next loop using the integer i, but they might be ordinary defined ranges of course.

TransferSheet.Range(ColLetter & SheetRow).Value = Range(ColLetter & i).Value TransferSheet.Range(ColLetter & SheetRow).NumberFormat = Range(ColLetter & i).NumberFormat

Centering a button vertically in table cell, using Twitter Bootstrap

A little update for Bootstrap 3.

Bootstrap now has the following style for table cells:

.table tbody>tr>td
{
    vertical-align: top;
}

The way to go is to add a your own class, with the same selector:

.table tbody>tr>td.vert-align
{
    vertical-align: middle;
}

And then add it to your tds

<td class="vert-align"></td>

Could not find method compile() for arguments Gradle

compile is a configuration that is usually introduced by a plugin (most likely the java plugin) Have a look at the gradle userguide for details about configurations. For now adding the java plugin on top of your build script should do the trick:

apply plugin:'java'

How to find if an array contains a string

I'm afraid I don't think there's a shortcut to do this - if only someone would write a linq wrapper for VB6!

You could write a function that does it by looping through the array and checking each entry - I don't think you'll get cleaner than that.

There's an example article that provides some details here: http://www.vb6.us/tutorials/searching-arrays-visual-basic-6

How to post a file from a form with Axios

Sample application using Vue. Requires a backend server running on localhost to process the request:

var app = new Vue({
  el: "#app",
  data: {
    file: ''
  },
  methods: {
    submitFile() {
      let formData = new FormData();
      formData.append('file', this.file);
      console.log('>> formData >> ', formData);

      // You should have a server side REST API 
      axios.post('http://localhost:8080/restapi/fileupload',
          formData, {
            headers: {
              'Content-Type': 'multipart/form-data'
            }
          }
        ).then(function () {
          console.log('SUCCESS!!');
        })
        .catch(function () {
          console.log('FAILURE!!');
        });
    },
    handleFileUpload() {
      this.file = this.$refs.file.files[0];
      console.log('>>>> 1st element in files array >>>> ', this.file);
    }
  }
});

https://codepen.io/pmarimuthu/pen/MqqaOE

javax.crypto.IllegalBlockSizeException : Input length must be multiple of 16 when decrypting with padded cipher

The algorithm you are using, "AES", is a shorthand for "AES/ECB/NoPadding". What this means is that you are using the AES algorithm with 128-bit key size and block size, with the ECB mode of operation and no padding.

In other words: you are only able to encrypt data in blocks of 128 bits or 16 bytes. That's why you are getting that IllegalBlockSizeException exception.

If you want to encrypt data in sizes that are not multiple of 16 bytes, you are either going to have to use some kind of padding, or a cipher-stream. For instance, you could use CBC mode (a mode of operation that effectively transforms a block cipher into a stream cipher) by specifying "AES/CBC/NoPadding" as the algorithm, or PKCS5 padding by specifying "AES/ECB/PKCS5", which will automatically add some bytes at the end of your data in a very specific format to make the size of the ciphertext multiple of 16 bytes, and in a way that the decryption algorithm will understand that it has to ignore some data.

In any case, I strongly suggest that you stop right now what you are doing and go study some very introductory material on cryptography. For instance, check Crypto I on Coursera. You should understand very well the implications of choosing one mode or another, what are their strengths and, most importantly, their weaknesses. Without this knowledge, it is very easy to build systems which are very easy to break.


Update: based on your comments on the question, don't ever encrypt passwords when storing them at a database!!!!! You should never, ever do this. You must HASH the passwords, properly salted, which is completely different from encrypting. Really, please, don't do what you are trying to do... By encrypting the passwords, they can be decrypted. What this means is that you, as the database manager and who knows the secret key, you will be able to read every password stored in your database. Either you knew this and are doing something very, very bad, or you didn't know this, and should get shocked and stop it.

Edit seaborn legend

If legend_out is set to True then legend is available thought g._legend property and it is a part of a figure. Seaborn legend is standard matplotlib legend object. Therefore you may change legend texts like:

import seaborn as sns

tips = sns.load_dataset("tips")
g = sns.lmplot(x="total_bill", y="tip", hue="smoker",
 data=tips, markers=["o", "x"], legend_out = True)

# title
new_title = 'My title'
g._legend.set_title(new_title)
# replace labels
new_labels = ['label 1', 'label 2']
for t, l in zip(g._legend.texts, new_labels): t.set_text(l)

sns.plt.show()

enter image description here

Another situation if legend_out is set to False. You have to define which axes has a legend (in below example this is axis number 0):

import seaborn as sns

tips = sns.load_dataset("tips")
g = sns.lmplot(x="total_bill", y="tip", hue="smoker",
 data=tips, markers=["o", "x"], legend_out = False)

# check axes and find which is have legend
leg = g.axes.flat[0].get_legend()
new_title = 'My title'
leg.set_title(new_title)
new_labels = ['label 1', 'label 2']
for t, l in zip(leg.texts, new_labels): t.set_text(l)
sns.plt.show()

enter image description here

Moreover you may combine both situations and use this code:

import seaborn as sns

tips = sns.load_dataset("tips")
g = sns.lmplot(x="total_bill", y="tip", hue="smoker",
 data=tips, markers=["o", "x"], legend_out = True)

# check axes and find which is have legend
for ax in g.axes.flat:
    leg = g.axes.flat[0].get_legend()
    if not leg is None: break
# or legend may be on a figure
if leg is None: leg = g._legend

# change legend texts
new_title = 'My title'
leg.set_title(new_title)
new_labels = ['label 1', 'label 2']
for t, l in zip(leg.texts, new_labels): t.set_text(l)

sns.plt.show()

This code works for any seaborn plot which is based on Grid class.

How to add data into ManyToMany field?

There's a whole page of the Django documentation devoted to this, well indexed from the contents page.

As that page states, you need to do:

my_obj.categories.add(fragmentCategory.objects.get(id=1))

or

my_obj.categories.create(name='val1')

How do you use bcrypt for hashing passwords in PHP?

The password_hash() function in PHP is an inbuilt function , used to create a new password hash with different algorithms and options. the function uses a strong hashing algorithm.

the function take 2 mandetory parametres ($password and $algorithm,) and 1 optional parameter ($options).

$strongPassword = password_hash( $password, $algorithm, $options )


Algoristrong textthms allowed right now for password_hash() are :

  • PASSWORD_DEFAULT

  • PASSWORD_BCRYPT

  • ASSWORD_ARGON2I

  • PASSWORD_ARGON2ID


example : echo password_hash("abcDEF", PASSWORD_DEFAULT);

answer : $2y$10$KwKceUaG84WInAif5ehdZOkE4kHPWTLp0ZK5a5OU2EbtdwQ9YIcGy


example: `echo password_hash("abcDEF", PASSWORD_BCRYPT);`

answer :$2y$10$SNly5bFzB/R6OVbBMq1bj.yiOZdsk6Mwgqi4BLR2sqdCvMyv/AyL2


to use the BCRYPT as password, use option cost =12 in an array , also change 1st parameter $password to some strong password like "wgt167yuWBGY@#1987__"

Example: echo password_hash("wgt167yuWBGY@#1987__", PASSWORD_BCRYPT ,['cost' => 12]);

Answer : $2y$12$TjSggXiFSidD63E.QP8PJOds2texJfsk/82VaNU8XRZ/niZhzkJ6S

How can I get a first element from a sorted list?

Matthew's answer is correct:

list.get(0);

To do what you tried:

list[0];

you'll have to wait until Java 7 is released:

devoxx conference http://img718.imageshack.us/img718/11/capturadepantalla201003cg.png

Here's an interesting presentation by Mark Reinhold about Java 7

It looks like parleys site is currently down, try later :(

Why do I get the "Unhandled exception type IOException"?

add "throws IOException" to your method like this:

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

        FileReader reader=new FileReader("db.properties");

        Properties p=new Properties();
        p.load(reader);


    }

Get month name from number

import datetime

monthinteger = 4

month = datetime.date(1900, monthinteger, 1).strftime('%B')

print month

April

Dynamic SQL - EXEC(@SQL) versus EXEC SP_EXECUTESQL(@SQL)

The big thing about SP_EXECUTESQL is that it allows you to create parameterized queries which is very good if you care about SQL injection.

Unbound classpath container in Eclipse

  1. right click on the project folder go to Properties at bottom
  2. go to Java Build path
  3. click on Libraries tab
  4. select Classpath
  5. click Add Add Library button on right
  6. select JRE System Library and click Next and then Finish
  7. click Apply and Close the error should go away in IDE.

How different is Objective-C from C++?

Off the top of my head:

  1. Styles - Obj-C is dynamic, C++ is typically static
  2. Although they are both OOP, I'm certain the solutions would be different.
  3. Different object model (C++ is restricted by its compile-time type system).

To me, the biggest difference is the model system. Obj-C lets you do messaging and introspection, but C++ has the ever-so-powerful templates.

Each have their strengths.

Java: Add elements to arraylist with FOR loop where element name has increasing number

Using Random function to generate number and iterating them on al using for loop

ArrayList<Integer> al=new ArrayList<Integer>(5);
    for (int i=0;i<=4;i++){

       Random rand=new Random();
        al.add(i,rand.nextInt(100));
        System.out.println(al);
    }
System.out.println(al.size());

How to get a parent element to appear above child

Fortunately a solution exists. You must add a wrapper for parent and change z-index of this wrapper for example 10, and set z-index for child to -1:

_x000D_
_x000D_
.parent {_x000D_
    position: relative;_x000D_
    width: 750px;_x000D_
    height: 7150px;_x000D_
    background: red;_x000D_
    border: solid 1px #000;_x000D_
    z-index: initial;_x000D_
}_x000D_
_x000D_
.child {_x000D_
    position: relative;_x000D_
    background-color: blue;_x000D_
    z-index: -1;_x000D_
    color: white;_x000D_
}_x000D_
_x000D_
.wrapper {_x000D_
    position: relative;_x000D_
    background: green;_x000D_
    z-index: 10;_x000D_
}
_x000D_
<div class="wrapper">_x000D_
    <div class="parent">parent parent_x000D_
        <div class="child">child child child</div>_x000D_
    </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to generate .json file with PHP?

Use this:

$json_data = json_encode($posts);
file_put_contents('myfile.json', $json_data);

You have to create the myfile.json before you run the script.

window.onload vs <body onload=""/>

There is no difference, but you should not use either.

In many browsers, the window.onload event is not triggered until all images have loaded, which is not what you want. Standards based browsers have an event called DOMContentLoaded which fires earlier, but it is not supported by IE (at the time of writing this answer). I'd recommend using a javascript library which supports a cross browser DOMContentLoaded feature, or finding a well written function you can use. jQuery's $(document).ready(), is a good example.

jQuery: How to capture the TAB keypress within a Textbox

You can capture an event tab using this JQuery API.

$( "#yourInputTextId" ).keydown(function(evt) {
   if(evt.key === "Tab")
      //call your function
});

cv2.imshow command doesn't work properly in opencv-python

If you choose to use "cv2.waitKey(0)", be sure that you have written "cv2.waitKey(0)" instead of "cv2.waitkey(0)", because that lowercase "k" might freeze your program too.

Call static methods from regular ES6 class methods

I stumbled over this thread searching for answer to similar case. Basically all answers are found, but it's still hard to extract the essentials from them.

Kinds of Access

Assume a class Foo probably derived from some other class(es) with probably more classes derived from it.

Then accessing

  • from static method/getter of Foo
    • some probably overridden static method/getter:
      • this.method()
      • this.property
    • some probably overridden instance method/getter:
      • impossible by design
    • own non-overridden static method/getter:
      • Foo.method()
      • Foo.property
    • own non-overridden instance method/getter:
      • impossible by design
  • from instance method/getter of Foo
    • some probably overridden static method/getter:
      • this.constructor.method()
      • this.constructor.property
    • some probably overridden instance method/getter:
      • this.method()
      • this.property
    • own non-overridden static method/getter:
      • Foo.method()
      • Foo.property
    • own non-overridden instance method/getter:
      • not possible by intention unless using some workaround:
        • Foo.prototype.method.call( this )
        • Object.getOwnPropertyDescriptor( Foo.prototype,"property" ).get.call(this);

Keep in mind that using this isn't working this way when using arrow functions or invoking methods/getters explicitly bound to custom value.

Background

  • When in context of an instance's method or getter
    • this is referring to current instance.
    • super is basically referring to same instance, but somewhat addressing methods and getters written in context of some class current one is extending (by using the prototype of Foo's prototype).
    • definition of instance's class used on creating it is available per this.constructor.
  • When in context of a static method or getter there is no "current instance" by intention and so
    • this is available to refer to the definition of current class directly.
    • super is not referring to some instance either, but to static methods and getters written in context of some class current one is extending.

Conclusion

Try this code:

_x000D_
_x000D_
class A {_x000D_
  constructor( input ) {_x000D_
    this.loose = this.constructor.getResult( input );_x000D_
    this.tight = A.getResult( input );_x000D_
    console.log( this.scaledProperty, Object.getOwnPropertyDescriptor( A.prototype, "scaledProperty" ).get.call( this ) );_x000D_
  }_x000D_
_x000D_
  get scaledProperty() {_x000D_
    return parseInt( this.loose ) * 100;_x000D_
  }_x000D_
  _x000D_
  static getResult( input ) {_x000D_
    return input * this.scale;_x000D_
  }_x000D_
  _x000D_
  static get scale() {_x000D_
    return 2;_x000D_
  }_x000D_
}_x000D_
_x000D_
class B extends A {_x000D_
  constructor( input ) {_x000D_
    super( input );_x000D_
    this.tight = B.getResult( input ) + " (of B)";_x000D_
  }_x000D_
  _x000D_
  get scaledProperty() {_x000D_
    return parseInt( this.loose ) * 10000;_x000D_
  }_x000D_
_x000D_
  static get scale() {_x000D_
    return 4;_x000D_
  }_x000D_
}_x000D_
_x000D_
class C extends B {_x000D_
  constructor( input ) {_x000D_
    super( input );_x000D_
  }_x000D_
  _x000D_
  static get scale() {_x000D_
    return 5;_x000D_
  }_x000D_
}_x000D_
_x000D_
class D extends C {_x000D_
  constructor( input ) {_x000D_
    super( input );_x000D_
  }_x000D_
  _x000D_
  static getResult( input ) {_x000D_
    return super.getResult( input ) + " (overridden)";_x000D_
  }_x000D_
  _x000D_
  static get scale() {_x000D_
    return 10;_x000D_
  }_x000D_
}_x000D_
_x000D_
_x000D_
let instanceA = new A( 4 );_x000D_
console.log( "A.loose", instanceA.loose );_x000D_
console.log( "A.tight", instanceA.tight );_x000D_
_x000D_
let instanceB = new B( 4 );_x000D_
console.log( "B.loose", instanceB.loose );_x000D_
console.log( "B.tight", instanceB.tight );_x000D_
_x000D_
let instanceC = new C( 4 );_x000D_
console.log( "C.loose", instanceC.loose );_x000D_
console.log( "C.tight", instanceC.tight );_x000D_
_x000D_
let instanceD = new D( 4 );_x000D_
console.log( "D.loose", instanceD.loose );_x000D_
console.log( "D.tight", instanceD.tight );
_x000D_
_x000D_
_x000D_

how to release localhost from Error: listen EADDRINUSE

When you get an error Error: listen EADDRINUSE,

Try running the following shell commands:

netstat -a -o | grep 8080
taskkill /F /PID 6204

I greped for 8080, because I know my server is running on port 8080. (static tells me when I start it: 'serving "." at http://127.0.0.1:8080'.) You might have to search for a different port.

Entity Framework 6 Code first Default value

It's been a while, but leaving a note for others. I achieved what is needed with an attribute and I decorated my model class fields with that attribute as I want.

[SqlDefaultValue(DefaultValue = "getutcdate()")]
public DateTime CreatedDateUtc { get; set; }

Got the help of these 2 articles:

What I did:

Define Attribute

[AttributeUsage(AttributeTargets.Property, AllowMultiple = false)]
public class SqlDefaultValueAttribute : Attribute
{
    public string DefaultValue { get; set; }
}

In the "OnModelCreating" of the context

modelBuilder.Conventions.Add( new AttributeToColumnAnnotationConvention<SqlDefaultValueAttribute, string>("SqlDefaultValue", (p, attributes) => attributes.Single().DefaultValue));

In the custom SqlGenerator

private void SetAnnotatedColumn(ColumnModel col)
{
    AnnotationValues values;
    if (col.Annotations.TryGetValue("SqlDefaultValue", out values))
    {
         col.DefaultValueSql = (string)values.NewValue;
    }
}

Then in the Migration Configuration constructor, register the custom SQL generator.

SetSqlGenerator("System.Data.SqlClient", new CustomMigrationSqlGenerator());

java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost:3306/dbname

An example of retrieving data from a table having columns column1, column2 ,column3 column4, cloumn1 and 2 hold int values and column 3 and 4 hold varchar(10)

import java.sql.*; 
// need to import this as the STEP 1. Has the classes that you mentioned  
public class JDBCexample {
    static final String JDBC_DRIVER = "com.mysql.jdbc.Driver"; 
    static final String DB_URL = "jdbc:mysql://LocalHost:3306/databaseNameHere"; 
    // DON'T PUT ANY SPACES IN BETWEEN and give the name of the database (case insensitive) 

    // database credentials
    static final String USER = "root";
    // usually when you install MySQL, it logs in as root 
    static final String PASS = "";
    // and the default password is blank

    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;

        try {
    // registering the driver__STEP 2
            Class.forName("com.mysql.jdbc.Driver"); 
    // returns a Class object of com.mysql.jdbc.Driver
    // (forName(""); initializes the class passed to it as String) i.e initializing the
    // "suitable" driver
            System.out.println("connecting to the database");
    // opening a connection__STEP 3
            conn = DriverManager.getConnection(DB_URL, USER, PASS);
    // executing a query__STEP 4 
            System.out.println("creating a statement..");
            stmt = conn.createStatement();
    // creating an object to create statements in SQL
            String sql;
            sql = "SELECT column1, cloumn2, column3, column4 from jdbcTest;";
    // this is what you would have typed in CLI for MySQL
            ResultSet rs = stmt.executeQuery(sql);
    // executing the query__STEP 5 (and retrieving the results in an object of ResultSet)
    // extracting data from result set
            while(rs.next()){
    // retrieve by column name
                int value1 = rs.getInt("column1");
                int value2 = rs.getInt("column2");
                String value3 = rs.getString("column3");
                String value4 = rs.getString("columnm4");
    // displaying values:
                System.out.println("column1 "+ value1);
                System.out.println("column2 "+ value2);
                System.out.println("column3 "+ value3);
                System.out.println("column4 "+ value4);

            }
    // cleaning up__STEP 6
            rs.close();
            stmt.close();
            conn.close();
        } catch (SQLException e) {
    //  handle sql exception
            e.printStackTrace();
        }catch (Exception e) {
    // TODO: handle exception for class.forName
            e.printStackTrace();
        }finally{  
    //closing the resources..STEP 7
            try {
                if (stmt != null)
                    stmt.close();
            } catch (SQLException e2) {
                e2.printStackTrace();
            }try {
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e2) {
                e2.printStackTrace();
            }
        }
        System.out.println("good bye");
    }
}

Importing a function from a class in another file?

from FOLDER_NAME import FILENAME
from FILENAME import CLASS_NAME FUNCTION_NAME

FILENAME is w/o the suffix

Load and execution sequence of a web page?

Open your page in Firefox and get the HTTPFox addon. It will tell you all that you need.

Found this on archivist.incuito:

http://archivist.incutio.com/viewlist/css-discuss/76444

When you first request a page, your browser sends a GET request to the server, which returns the HTML to the browser. The browser then starts parsing the page (possibly before all of it has been returned).

When it finds a reference to an external entity such as a CSS file, an image file, a script file, a Flash file, or anything else external to the page (either on the same server/domain or not), it prepares to make a further GET request for that resource.

However the HTTP standard specifies that the browser should not make more than two concurrent requests to the same domain. So it puts each request to a particular domain in a queue, and as each entity is returned it starts the next one in the queue for that domain.

The time it takes for an entity to be returned depends on its size, the load the server is currently experiencing, and the activity of every single machine between the machine running the browser and the server. The list of these machines can in principle be different for every request, to the extent that one image might travel from the USA to me in the UK over the Atlantic, while another from the same server comes out via the Pacific, Asia and Europe, which takes longer. So you might get a sequence like the following, where a page has (in this order) references to three script files, and five image files, all of differing sizes:

  1. GET script1 and script2; queue request for script3 and images1-5.
  2. script2 arrives (it's smaller than script1): GET script3, queue images1-5.
  3. script1 arrives; GET image1, queue images2-5.
  4. image1 arrives, GET image2, queue images3-5.
  5. script3 fails to arrive due to a network problem - GET script3 again (automatic retry).
  6. image2 arrives, script3 still not here; GET image3, queue images4-5.
  7. image 3 arrives; GET image4, queue image5, script3 still on the way.
  8. image4 arrives, GET image5;
  9. image5 arrives.
  10. script3 arrives.

In short: any old order, depending on what the server is doing, what the rest of the Internet is doing, and whether or not anything has errors and has to be re-fetched. This may seem like a weird way of doing things, but it would quite literally be impossible for the Internet (not just the WWW) to work with any degree of reliability if it wasn't done this way.

Also, the browser's internal queue might not fetch entities in the order they appear in the page - it's not required to by any standard.

(Oh, and don't forget caching, both in the browser and in caching proxies used by ISPs to ease the load on the network.)

Debugging Spring configuration

If you use Spring Boot, you can also enable a “debug” mode by starting your application with a --debug flag.

java -jar myapp.jar --debug

You can also specify debug=true in your application.properties.

When the debug mode is enabled, a selection of core loggers (embedded container, Hibernate, and Spring Boot) are configured to output more information. Enabling the debug mode does not configure your application to log all messages with DEBUG level.

Alternatively, you can enable a “trace” mode by starting your application with a --trace flag (or trace=true in your application.properties). Doing so enables trace logging for a selection of core loggers (embedded container, Hibernate schema generation, and the whole Spring portfolio).

https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-logging.html

Generate preview image from Video file?

Solution #1 (Older) (not recommended)

Firstly install ffmpeg-php project (http://ffmpeg-php.sourceforge.net/)

And then you can use of this simple code:

<?php
$frame = 10;
$movie = 'test.mp4';
$thumbnail = 'thumbnail.png';

$mov = new ffmpeg_movie($movie);
$frame = $mov->getFrame($frame);
if ($frame) {
    $gd_image = $frame->toGDImage();
    if ($gd_image) {
        imagepng($gd_image, $thumbnail);
        imagedestroy($gd_image);
        echo '<img src="'.$thumbnail.'">';
    }
}
?>

Description: This project use binary extension .so file, It's very old and last update was for 2008. So, maybe don't works with newer version of FFMpeg or PHP.


Solution #2 (Update 2018) (recommended)

Firstly install PHP-FFMpeg project (https://github.com/PHP-FFMpeg/PHP-FFMpeg)
(just run for install: composer require php-ffmpeg/php-ffmpeg)

And then you can use of this simple code:

<?php
require 'vendor/autoload.php';

$sec = 10;
$movie = 'test.mp4';
$thumbnail = 'thumbnail.png';

$ffmpeg = FFMpeg\FFMpeg::create();
$video = $ffmpeg->open($movie);
$frame = $video->frame(FFMpeg\Coordinate\TimeCode::fromSeconds($sec));
$frame->save($thumbnail);
echo '<img src="'.$thumbnail.'">';

Description: It's newer and more modern project and works with latest version of FFMpeg and PHP. Note that it's required to proc_open() PHP function.

How to run a cronjob every X minutes?

# .---------------- minute (0 - 59)
# |  .------------- hour (0 - 23)
# |  |  .---------- day of month (1 - 31)
# |  |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |  |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# |  |  |  |  |
# *  *  *  *  * user-name  command to be executed

To set for x minutes we need to set x minutes in the 1st argument and then the path of your script

For 15 mins

*/15 * * * *  /usr/bin/php /mydomain.in/cromail.php > /dev/null 2>&1

Eclipse Indigo - Cannot install Android ADT Plugin

Execute eclipse with root level

$sudo /opt/eclipse/eclipse

How do I detect the Python version at runtime?

Since all you are interested in is whether you have Python 2 or 3, a bit hackish but definitely the simplest and 100% working way of doing that would be as follows: python python_version_major = 3/2*2 The only drawback of this is that when there is Python 4, it will probably still give you 3.

Style jQuery autocomplete in a Bootstrap input field

Try this (demo):

.ui-autocomplete {
  position: absolute;
  top: 100%;
  left: 0;
  z-index: 1000;
  display: none;
  float: left;
  min-width: 160px;
  padding: 5px 0;
  margin: 2px 0 0;
  list-style: none;
  font-size: 14px;
  text-align: left;
  background-color: #ffffff;
  border: 1px solid #cccccc;
  border: 1px solid rgba(0, 0, 0, 0.15);
  border-radius: 4px;
  -webkit-box-shadow: 0 6px 12px rgba(0, 0, 0, 0.175);
  box-shadow: 0 6px 12px rgba(0, 0, 0, 0.175);
  background-clip: padding-box;
}

.ui-autocomplete > li > div {
  display: block;
  padding: 3px 20px;
  clear: both;
  font-weight: normal;
  line-height: 1.42857143;
  color: #333333;
  white-space: nowrap;
}

.ui-state-hover,
.ui-state-active,
.ui-state-focus {
  text-decoration: none;
  color: #262626;
  background-color: #f5f5f5;
  cursor: pointer;
}

.ui-helper-hidden-accessible {
  border: 0;
  clip: rect(0 0 0 0);
  height: 1px;
  margin: -1px;
  overflow: hidden;
  padding: 0;
  position: absolute;
  width: 1px;
}

Python: Is there an equivalent of mid, right, and left from BASIC?

You can use this method also it will act like that

thadari=[1,2,3,4,5,6]

#Front Two(Left)
print(thadari[:2])
[1,2]

#Last Two(Right)# edited
print(thadari[-2:])
[5,6]

#mid
mid = len(thadari) //2

lefthalf = thadari[:mid]
[1,2,3]
righthalf = thadari[mid:]
[4,5,6]

Hope it will help

Ruby on Rails: How do I add placeholder text to a f.text_field?

In your view template, set a default value:

f.text_field :password, :value => "password"

In your Javascript (assuming jquery here):

$(document).ready(function() {
  //add a handler to remove the text
});

How to determine if a decimal/double is an integer?

bool IsInteger(double num) {
    if (ceil(num) == num && floor(num) == num)
        return true;
    else
        return false;
}

Problemo solvo.

Edit: Pwned by Mark Rushakoff.

Wait for shell command to complete

what you proposed with a change at the parenthesis at the Run command worked fine with VBA for me

Dim wsh As Object
Set wsh = VBA.CreateObject("WScript.Shell")
Dim waitOnReturn As Boolean: waitOnReturn = True
Dim windowStyle As Integer: windowStyle = 1
Dim errorCode As Integer
wsh.Run "C:\folder\runbat.bat", windowStyle, waitOnReturn

Match exact string

Use the start and end delimiters: ^abc$

How to handle a single quote in Oracle SQL

Use two single-quotes

SQL> SELECT 'D''COSTA' name FROM DUAL;

NAME
-------
D'COSTA

Alternatively, use the new (10g+) quoting method:

SQL> SELECT q'$D'COSTA$' NAME FROM DUAL;

NAME
-------
D'COSTA

Making button go full-width?

Why not use the Bootstrap predefined class input-block-level that does the job?

<a href="#" class="btn input-block-level">Full-Width Button</a> <!-- BS2 -->
<a href="#" class="btn form-control">Full-Width Button</a> <!-- BS3 -->

<!-- And let's join both for BS# :) -->
<a href="#" class="btn input-block-level form-control">Full-Width Button</a>

Learn more here in the Control Sizing^ section.

How can I change the version of npm using nvm?

By looking at www.npmjs.com/install.sh I found there is a way to install a specific version by setting an environment-variable

export npm_install="2.14.14"

Then run the download-script as described at npmjs.com:

curl -L https://www.npmjs.com/install.sh | sh

If you omit setting the npm_install variable, then it will install the the version they have marked as latest

Prevent nginx 504 Gateway timeout using PHP set_time_limit()

You need to add extra nginx directive (for ngx_http_proxy_module) in nginx.conf, e.g.:

proxy_read_timeout 300;

Basically the nginx proxy_read_timeout directive changes the proxy timeout, the FcgidIOTimeout is for scripts that are quiet too long, and FcgidBusyTimeout is for scripts that take too long to execute.

Also if you're using FastCGI application, increase these options as well:

FcgidBusyTimeout 300
FcgidIOTimeout 250

Then reload nginx and PHP5-FPM.

Plesk

In Plesk, you can add it in Web Server Settings under Additional nginx directives.

For FastCGI check in Web Server Settings under Additional directives for HTTP.

See: How to fix FastCGI timeout issues in Plesk?

Trim Whitespaces (New Line and Tab space) in a String in Oracle

I know this is not a strict answer for this question, but I've been working in several scenarios where you need to transform text data following these rules:

  1. No spaces or ctrl chars at the beginning of the string
  2. No spaces or ctrl chars at the end of the string
  3. Multiple ocurrencies of spaces or ctrl chars will be replaced to a single space

Code below follow the rules detailed above:

WITH test_view AS (
  SELECT CHR(9) || 'Q   qwer' || CHR(9) || CHR(10) ||
         CHR(13) || ' qwerqwer     qwerty  ' || CHR(9) || 
         CHR(10) || CHR(13) str
  FROM DUAL
) SELECT 
     str original
    ,TRIM(REGEXP_REPLACE(str, '([[:space:]]{2,}|[[:cntrl:]])', ' ')) fixed
  FROM test_view;


ORIGINAL               FIXED                 
---------------------- ----------------------
    Q   qwer           Q qwer qwerqwer qwerty

 qwerqwer     qwerty                                         

1 row selected.

MySQL: View with Subquery in the FROM Clause Limitation

Couldn't your query just be written as:

SELECT u1.name as UserName from Message m1, User u1 
  WHERE u1.uid = m1.UserFromID GROUP BY u1.name HAVING count(m1.UserFromId)>3

That should also help with the known speed issues with subqueries in MySQL

creating json object with variables

if you need double quoted JSON use JSON.stringify( object)

var $items = $('#firstName, #lastName,#phoneNumber,#address ')
var obj = {}
$items.each(function() {
    obj[this.id] = $(this).val();
})

var json= JSON.stringify( obj);

DEMO: http://jsfiddle.net/vANKa/1

How do you check what version of SQL Server for a database using TSQL?

SELECT 
@@SERVERNAME AS ServerName,
CASE WHEN LEFT(CAST(serverproperty('productversion') as char), 1) = 9 THEN '2005'
 WHEN LEFT(CAST(serverproperty('productversion') as char), 2) = 10 THEN '2008'
 WHEN LEFT(CAST(serverproperty('productversion') as char), 2) = 11 THEN '2012'
END AS MajorVersion,
SERVERPROPERTY ('productlevel') AS MinorVersion, 
SERVERPROPERTY('productversion') AS FullVersion, 
SERVERPROPERTY ('edition') AS Edition

How to get the path of the batch script in Windows?

%cd% will give you the path of the directory from where the script is running.

Just run:

echo %cd%

eclipse stuck when building workspace

I tried lots of these suggestions, but the only thing that finally worked for me was creating a new workspace, and freshly checking out all my projects into that folder. Then it worked fine ;-)

How to change time in DateTime?

I have just come across this post because I had a similar issue whereby I wanted to set the time for an Entity Framework object in MVC that gets the date from a view (datepicker) so the time component is 00:00:00 but I need it to be the current time. Based on the answers in this post I came up with:

myEntity.FromDate += DateTime.Now.TimeOfDay;

What is the difference between an abstract function and a virtual function?

  1. Only abstract classes can have abstract members.
  2. A non-abstract class that inherits from an abstract class must override its abstract members.
  3. An abstract member is implicitly virtual.
  4. An abstract member cannot provide any implementation (abstract is called pure virtual in some languages).

SSH Key - Still asking for password and passphrase

Generally, here are the steps to allow you make a remote connection to your server using ssh without password:

  • Create a pair of rsa private and public key

    $ ssh-keygen -t rsa -b 4096 -C "your comments"
    
  • Copy your public key and login to your remote server

  • Add your public key to .ssh/authorized_keys

  • If you have multiple ssh keys in your computer you might to add your key using ssh-add

    $ ssh-add /path/to/private/key

  • Then try ssh to your server

    $ ssh username@your_ip_address

Source: http://diary-of-programmer.blogspot.com/2018/08/tips-how-to-ssh-to-your-digitalocean.html

Which characters need to be escaped when using Bash?

To save someone else from having to RTFM... in bash:

Enclosing characters in double quotes preserves the literal value of all characters within the quotes, with the exception of $, `, \, and, when history expansion is enabled, !.

...so if you escape those (and the quote itself, of course) you're probably okay.

If you take a more conservative 'when in doubt, escape it' approach, it should be possible to avoid getting instead characters with special meaning by not escaping identifier characters (i.e. ASCII letters, numbers, or '_'). It's very unlikely these would ever (i.e. in some weird POSIX-ish shell) have special meaning and thus need to be escaped.

Could not calculate build plan: Plugin org.apache.maven.plugins:maven-jar-plugin:2.3.2 or one of its dependencies could not be resolved

There could be multiple reasons, i fixed with following steps:

  1. delete .m2 folder and re launch eclipse. (Find m2 folder in windows: c:\Users\Your_User_Name\ .m2 or to search in Mac : ~/.m2
  2. make sure settings.xml is configured as #JustinBieber mentioned.
  3. provide settings.xml path in eclipse (windows->preferences->maven->user settings) User Settings must locate settings.xml file.

save changes and relaunch the eclipse..!! it should work.

Error in model.frame.default: variable lengths differ

Another thing that can cause this error is creating a model with the centering/scaling standardize function from the arm package -- m <- standardize(lm(y ~ x, data = train))

If you then try predict(m), you get the same error as in this question.

What does -save-dev mean in npm install grunt --save-dev

--save-dev means "needed only when developing"

  • e.g. the final users using your package will not want/need/care about what testing suite you used; they will only want packages that are absolutely required to run your code in a production environment. This flag marks what is needed when developing vs production.

What is the difference between Views and Materialized Views in Oracle?

Views

They evaluate the data in the tables underlying the view definition at the time the view is queried. It is a logical view of your tables, with no data stored anywhere else.

The upside of a view is that it will always return the latest data to you. The downside of a view is that its performance depends on how good a select statement the view is based on. If the select statement used by the view joins many tables, or uses joins based on non-indexed columns, the view could perform poorly.

Materialized views

They are similar to regular views, in that they are a logical view of your data (based on a select statement), however, the underlying query result set has been saved to a table. The upside of this is that when you query a materialized view, you are querying a table, which may also be indexed.

In addition, because all the joins have been resolved at materialized view refresh time, you pay the price of the join once (or as often as you refresh your materialized view), rather than each time you select from the materialized view. In addition, with query rewrite enabled, Oracle can optimize a query that selects from the source of your materialized view in such a way that it instead reads from your materialized view. In situations where you create materialized views as forms of aggregate tables, or as copies of frequently executed queries, this can greatly speed up the response time of your end user application. The downside though is that the data you get back from the materialized view is only as up to date as the last time the materialized view has been refreshed.


Materialized views can be set to refresh manually, on a set schedule, or based on the database detecting a change in data from one of the underlying tables. Materialized views can be incrementally updated by combining them with materialized view logs, which act as change data capture sources on the underlying tables.

Materialized views are most often used in data warehousing / business intelligence applications where querying large fact tables with thousands of millions of rows would result in query response times that resulted in an unusable application.


Materialized views also help to guarantee a consistent moment in time, similar to snapshot isolation.

What is the SQL command to return the field names of a table?

SQL-92 standard defines INFORMATION_SCHEMA which conforming rdbms's like MS SQL Server support. The following works for MS SQL Server 2000/2005/2008 and MySql 5 and above

select COLUMN_NAME from INFORMATION_SCHEMA.COLUMNS where TABLE_NAME = 'myTable'

MS SQl Server Specific:

exec sp_help 'myTable'

This solution returns several result sets within which is the information you desire, where as the former gives you exactly what you want.

Also just for completeness you can query the sys tables directly. This is not recommended as the schema can change between versions of SQL Server and INFORMATION_SCHEMA is a layer of abstraction above these tables. But here it is anyway for SQL Server 2000

select [name] from dbo.syscolumns where id = object_id(N'[dbo].[myTable]')

How to Install gcc 5.3 with yum on CentOS 7.2?

You can use the centos-sclo-rh-testing repo to install GCC v7 without having to compile it forever, also enable V7 by default and let you switch between different versions if required.

sudo yum install -y yum-utils centos-release-scl;
sudo yum -y --enablerepo=centos-sclo-rh-testing install devtoolset-7-gcc;
echo "source /opt/rh/devtoolset-7/enable" | sudo tee -a /etc/profile;
source /opt/rh/devtoolset-7/enable;
gcc --version;