Programs & Examples On #Parameterized query

A pre-compiled and optimized SQL statement that can be executed multiple times by changing certain constant values during each execution. Often used to prevent SQL injection.

How to make a <button> in Bootstrap look like a normal link in nav-tabs?

Just make regular link look like button :)

<a href="#" role="button" class="btn btn-success btn-large">Click here!</a>

"role" inside a href code makes it look like button, ofc you can add more variables such as class.

How to create radio buttons and checkbox in swift (iOS)?

Checkbox

You can create your own CheckBox control extending UIButton with Swift:

import UIKit

class CheckBox: UIButton {
    // Images
    let checkedImage = UIImage(named: "ic_check_box")! as UIImage
    let uncheckedImage = UIImage(named: "ic_check_box_outline_blank")! as UIImage
    
    // Bool property
    var isChecked: Bool = false {
        didSet {
            if isChecked == true {
                self.setImage(checkedImage, for: UIControl.State.normal)
            } else {
                self.setImage(uncheckedImage, for: UIControl.State.normal)
            }
        }
    }
        
    override func awakeFromNib() {
        self.addTarget(self, action:#selector(buttonClicked(sender:)), for: UIControl.Event.touchUpInside)
        self.isChecked = false
    }
        
    @objc func buttonClicked(sender: UIButton) {
        if sender == self {
            isChecked = !isChecked
        }
    }
}

And then add it to your views with Interface Builder:

enter image description here

Radio Buttons

Radio Buttons can be solved in a similar way.

For example, the classic gender selection Woman - Man:

enter image description here

import UIKit

class RadioButton: UIButton {
    var alternateButton:Array<RadioButton>?
    
    override func awakeFromNib() {
        self.layer.cornerRadius = 5
        self.layer.borderWidth = 2.0
        self.layer.masksToBounds = true
    }
    
    func unselectAlternateButtons() {
        if alternateButton != nil {
            self.isSelected = true
            
            for aButton:RadioButton in alternateButton! {
                aButton.isSelected = false
            }
        } else {
            toggleButton()
        }
    }
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        unselectAlternateButtons()
        super.touchesBegan(touches, with: event)
    }
    
    func toggleButton() {
        self.isSelected = !isSelected
    }
    
    override var isSelected: Bool {
        didSet {
            if isSelected {
                self.layer.borderColor = Color.turquoise.cgColor
            } else {
                self.layer.borderColor = Color.grey_99.cgColor
            }
        }
    }
}

You can init your radio buttons like this:

    override func awakeFromNib() {
        self.view.layoutIfNeeded()
        
        womanRadioButton.selected = true
        manRadioButton.selected = false
    }
    
    override func viewDidLoad() {
        womanRadioButton?.alternateButton = [manRadioButton!]
        manRadioButton?.alternateButton = [womanRadioButton!]
    }

Hope it helps.

Find out how much memory is being used by an object in Python

I haven't any personal experience with either of the following, but a simple search for a "Python [memory] profiler" yield:

  • PySizer, "a memory profiler for Python," found at http://pysizer.8325.org/. However the page seems to indicate that the project hasn't been updated for a while, and refers to...

  • Heapy, "support[ing] debugging and optimization regarding memory related issues in Python programs," found at http://guppy-pe.sourceforge.net/#Heapy.

Hope that helps.

How to get the ASCII value of a character

The accepted answer is correct, but there is a more clever/efficient way to do this if you need to convert a whole bunch of ASCII characters to their ASCII codes at once. Instead of doing:

for ch in mystr:
    code = ord(ch)

or the slightly faster:

for code in map(ord, mystr):

you convert to Python native types that iterate the codes directly. On Python 3, it's trivial:

for code in mystr.encode('ascii'):

and on Python 2.6/2.7, it's only slightly more involved because it doesn't have a Py3 style bytes object (bytes is an alias for str, which iterates by character), but they do have bytearray:

# If mystr is definitely str, not unicode
for code in bytearray(mystr):

# If mystr could be either str or unicode
for code in bytearray(mystr, 'ascii'):

Encoding as a type that natively iterates by ordinal means the conversion goes much faster; in local tests on both Py2.7 and Py3.5, iterating a str to get its ASCII codes using map(ord, mystr) starts off taking about twice as long for a len 10 str than using bytearray(mystr) on Py2 or mystr.encode('ascii') on Py3, and as the str gets longer, the multiplier paid for map(ord, mystr) rises to ~6.5x-7x.

The only downside is that the conversion is all at once, so your first result might take a little longer, and a truly enormous str would have a proportionately large temporary bytes/bytearray, but unless this forces you into page thrashing, this isn't likely to matter.

Convert a string date into datetime in Oracle

You can use a cast to char to see the date results

_x000D_
_x000D_
 select to_char(to_date('17-MAR-17 06.04.54','dd-MON-yy hh24:mi:ss'), 'mm/dd/yyyy hh24:mi:ss') from dual;
_x000D_
_x000D_
_x000D_

How can I specify a branch/tag when adding a Git submodule?

I'd like to add an answer here that is really just a conglomerate of other answers, but I think it may be more complete.

You know you have a Git submodule when you have these two things.

  1. Your .gitmodules has an entry like so:

    [submodule "SubmoduleTestRepo"]
        path = SubmoduleTestRepo
        url = https://github.com/jzaccone/SubmoduleTestRepo.git
    
  2. You have a submodule object (named SubmoduleTestRepo in this example) in your Git repository. GitHub shows these as "submodule" objects. Or do git submodule status from a command line. Git submodule objects are special kinds of Git objects, and they hold the SHA information for a specific commit.

    Whenever you do a git submodule update, it will populate your submodule with content from the commit. It knows where to find the commit because of the information in the .gitmodules.

    Now, all the -b does is add one line in your .gitmodules file. So following the same example, it would look like this:

    [submodule "SubmoduleTestRepo"]
        path = SubmoduleTestRepo
        url = https://github.com/jzaccone/SubmoduleTestRepo.git
        branch = master
    

    Note: only branch name is supported in a .gitmodules file, but SHA and TAG are not supported! (instead of that, the branch's commit of each module can be tracked and updated using "git add .", for example like git add ./SubmoduleTestRepo, and you do not need to change the .gitmodules file each time)

    The submodule object is still pointing at a specific commit. The only thing that the -b option buys you is the ability to add a --remote flag to your update as per Vogella's answer:

    git submodule update --remote
    

    Instead of populating the content of the submodule to the commit pointed to by the submodule, it replaces that commit with the latest commit on the master branch, THEN it populates the submodule with that commit. This can be done in two steps by djacobs7 answer. Since you have now updated the commit the submodule object is pointing to, you have to commit the changed submodule object into your Git repository.

    git submodule add -b is not some magically way to keep everything up to date with a branch. It is simply adds information about a branch in the .gitmodules file and gives you the option to update the submodule object to the latest commit of a specified branch before populating it.

How do I convert a float to an int in Objective C?

In support of unwind, remember that Objective-C is a superset of C, rather than a completely new language.

Anything you can do in regular old ANSI C can be done in Objective-C.

Regex match digits, comma and semicolon?

Try word.matches("^[0-9,;]+$");

Unable to access JSON property with "-" dash

jsonObj.profile-id is a subtraction expression (i.e. jsonObj.profile - id).

To access a key that contains characters that cannot appear in an identifier, use brackets:

jsonObj["profile-id"]

Where can I set environment variables that crontab will use?

Have 'cron' run a shell script that sets the environment before running the command.

Always.

#   @(#)$Id: crontab,v 4.2 2007/09/17 02:41:00 jleffler Exp $
#   Crontab file for Home Directory for Jonathan Leffler (JL)
#-----------------------------------------------------------------------------
#Min     Hour    Day     Month   Weekday Command
#-----------------------------------------------------------------------------
0        *       *       *       *       /usr/bin/ksh /work1/jleffler/bin/Cron/hourly
1        1       *       *       *       /usr/bin/ksh /work1/jleffler/bin/Cron/daily
23       1       *       *       1-5     /usr/bin/ksh /work1/jleffler/bin/Cron/weekday
2        3       *       *       0       /usr/bin/ksh /work1/jleffler/bin/Cron/weekly
21       3       1       *       *       /usr/bin/ksh /work1/jleffler/bin/Cron/monthly

The scripts in ~/bin/Cron are all links to a single script, 'runcron', which looks like:

:       "$Id: runcron.sh,v 2.1 2001/02/27 00:53:22 jleffler Exp $"
#
#       Commands to be performed by Cron (no debugging options)

#       Set environment -- not done by cron (usually switches HOME)
. $HOME/.cronfile

base=`basename $0`
cmd=${REAL_HOME:-/real/home}/bin/$base

if [ ! -x $cmd ]
then cmd=${HOME}/bin/$base
fi

exec $cmd ${@:+"$@"}

(Written using an older coding standard - nowadays, I'd use a shebang '#!' at the start.)

The '~/.cronfile' is a variation on my profile for use by cron - rigorously non-interactive and no echoing for the sake of being noisy. You could arrange to execute the .profile and so on instead. (The REAL_HOME stuff is an artefact of my environment - you can pretend it is the same as $HOME.)

So, this code reads the appropriate environment and then executes the non-Cron version of the command from my home directory. So, for example, my 'weekday' command looks like:

:       "@(#)$Id: weekday.sh,v 1.10 2007/09/17 02:42:03 jleffler Exp $"
#
#       Commands to be done each weekday

# Update ICSCOPE
n.updics

The 'daily' command is simpler:

:       "@(#)$Id: daily.sh,v 1.5 1997/06/02 22:04:21 johnl Exp $"
#
#       Commands to be done daily

# Nothing -- most things are done on weekdays only

exit 0

Fix columns in horizontal scrolling

Demo: http://www.jqueryscript.net/demo/jQuery-Plugin-For-Fixed-Table-Header-Footer-Columns-TableHeadFixer/

HTML

<h2>TableHeadFixer Fix Left Column</h2>

<div id="parent">
    <table id="fixTable" class="table">
        <thead>
            <tr>
                <th>Ano</th>
                <th>Jan</th>
                <th>Fev</th>
                <th>Mar</th>
                <th>Abr</th>
                <th>Maio</th>
                <th>Total</th>
            </tr>
        </thead>
        <tbody>
            <tr>
                <td>2012</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>550.00</td>
            </tr>
            <tr>
                <td>2012</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>550.00</td>
            </tr>
            <tr>
                <td>2012</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>550.00</td>
            </tr>
            <tr>
                <td>2012</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>550.00</td>
            </tr>
            <tr>
                <td>2012</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>110.00</td>
                <td>550.00</td>
            </tr>
        </tbody>
    </table>
</div>

JS

    $(document).ready(function() {
        $("#fixTable").tableHeadFixer({"head" : false, "right" : 1}); 
    });

CSS

    #parent {
        height: 300px;
    }

    #fixTable {
        width: 1800px !important;
    }

https://jsfiddle.net/5gfuqqc4/

Createuser: could not connect to database postgres: FATAL: role "tom" does not exist

Your error is posted in the official documentation. You can read this article.

I have copied the reason for you (and hyperlinked the URLs) from that article:

This will happen if the administrator has not created a PostgreSQL user account for you. (PostgreSQL user accounts are distinct from operating system user accounts.) If you are the administrator, see Chapter 20 for help creating accounts. You will need to become the operating system user under which PostgreSQL was installed (usually postgres) to create the first user account. It could also be that you were assigned a PostgreSQL user name that is different from your operating system user name; in that case you need to use the -U switch or set the PGUSER environment variable to specify your PostgreSQL user name

For your purposes, you can do:

1) Create a PostgreSQL user account:

sudo -u postgres createuser tom -d -P

(the -P option to set a password; the -d option for allowing the creation of database for your username 'tom'. Note that 'tom' is your operating system username. That way, you can execute PostgreSQL commands without sudoing.)

2) Now you should be able to execute createdb and other PostgreSQL commands.

Are static class variables possible in Python?

Yes, definitely possible to write static variables and methods in python.

Static Variables : Variable declared at class level are called static variable which can be accessed directly using class name.

    >>> class A:
        ...my_var = "shagun"

    >>> print(A.my_var)
        shagun

Instance variables: Variables that are related and accessed by instance of a class are instance variables.

   >>> a = A()
   >>> a.my_var = "pruthi"
   >>> print(A.my_var,a.my_var)
       shagun pruthi

Static Methods: Similar to variables, static methods can be accessed directly using class Name. No need to create an instance.

But keep in mind, a static method cannot call a non-static method in python.

    >>> class A:
   ...     @staticmethod
   ...     def my_static_method():
   ...             print("Yippey!!")
   ... 
   >>> A.my_static_method()
   Yippey!!

Could not calculate build plan: Plugin org.apache.maven.plugins:maven-resources-plugin:2.6 or one of its dependencies could not be resolved

This helped me: I created a new maven project which was working fine in my old workspace, but gave above errors in the new workspace. I had to do the following: - Open old workspace on Eclipse - open Preferences tab - Search Maven in filter - Copy the path for settings.xml from User Settings - User Settings - Switch to new workspace - Update the preferences - Maven - User Settings - User Settings path

After the build is completed, all errors are resolved.

Jquery-How to grey out the background while showing the loading icon over it

1) "container" is a class and not an ID 2) .container - set z-index and display: none in your CSS and not inline unless there is a really good reason to do so. Demo@fiddle

$("#button").click(function() {
    $(".container").css("opacity", 0.2);
   $("#loading-img").css({"display": "block"});
});

CSS:

#loading-img {
    background: url(http://web.bogdanteodoru.com/wp-content/uploads/2012/01/bouncy-css3-loading-animation.jpg) center center no-repeat;  /* different for testing purposes */
    display: none;
    height: 100px; /* for testing purposes */
    z-index: 12;
}

And a demo with animated image.

How do I include negative decimal numbers in this regular expression?

Some Regular expression examples:

Positive Integers:

^\d+$

Negative Integers:

^-\d+$

Integer:

^-?\d+$

Positive Number:

^\d*\.?\d+$

Negative Number:

^-\d*\.?\d+$

Positive Number or Negative Number:

^-?\d*\.{0,1}\d+$

Phone number:

^\+?[\d\s]{3,}$

Phone with code:

^\+?[\d\s]+\(?[\d\s]{10,}$

Year 1900-2099:

^(19|20)[\d]{2,2}$

Date (dd mm yyyy, d/m/yyyy, etc.):

^([1-9]|0[1-9]|[12][0-9]|3[01])\D([1-9]|0[1-9]|1[012])\D(19[0-9][0-9]|20[0-9][0-9])$

IP v4:

^(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5]){3}$

How can I find the latitude and longitude from address?

An answer to Kandha problem above :

It throws the "java.io.IOException service not available" i already gave those permission and include the library...i can get map view...it throws that IOException at geocoder...

I just added a catch IOException after the try and it solved the problem

    catch(IOException ioEx){
        return null;
    }

Javascript objects: get parent

To further iterate on Mik's answer, you could also recursivey attach a parent to all nested objects.

var myApp = {

    init: function() {
        for (var i in this) {
            if (typeof this[i] == 'object') {
                    this[i].init = this.init;
                    this[i].init();
                    this[i].parent = this;
            }
        }
        return this;
    },

    obj1: {
        obj2: {
            notify: function() {
                console.log(this.parent.parent.obj3.msg);
            }
        }
    },

    obj3: {
        msg: 'Hello'
    }

}.init();

myApp.obj1.obj2.notify();

http://jsbin.com/zupepelaciya/1/watch?js,console

Auto-indent in Notepad++

Try to save the file before, then it will indent.

Can I change the headers of the HTTP request sent by the browser?

I would partially disagree with Milan's suggestion of embedding the requested representation in the URI.

If anyhow possible, URIs should only be used for addressing resources and not for tunneling HTTP methods/verbs. Eventually, specific business action (edit, lock, etc.) could be embedded in the URI if create (POST) or update (PUT) alone do not serve the purpose:

POST http://shonzilla.com/orders/08/165;edit

In the case of requesting a particular representation in URI you would need to disrupt your URI design eventually making it uglier, mixing two distinct REST concepts in the same place (i.e. URI) and making it harder to generically process requests on the server-side. What Milan is suggesting and many are doing the same, incl. Flickr, is exactly this.

Instead, a more RESTful approach would be using a separate place to encode preferred representation by using Accept HTTP header which is used for content negotiation where client tells to the server which content types it can handle/process and server tries to fulfill client's request. This approach is a part of HTTP 1.1 standard, software compliant and supported by web browsers as well.

Compare this:

GET /orders/08/165.xml HTTP/1.1
or
GET /orders/08/165&format=xml HTTP/1.1

to this:

GET /orders/08/165 HTTP/1.1
Accept: application/xml

From a web browser you can request any content type by using setRequestHeader method of XMLHttpRequest object. For example:

function getOrder(year, yearlyOrderId, contentType) {
 var client = new XMLHttpRequest();
 client.open("GET", "/order/" + year + "/" + yearlyOrderId);
 client.setRequestHeader("Accept", contentType);
 client.send(orderDetails);
}

To sum it up: the address, i.e. the URI of a resource should be independent of its representation and XMLHttpRequest.setRequestHeader method allows you to request any representation using the Accept HTTP header.

Cheers!
Shonzilla

Programmatically obtain the phone number of the Android phone

Wouldn't be recommending to use TelephonyManager as it requires the app to require READ_PHONE_STATE permission during runtime.

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

Should be using Google's Play Service for Authentication, and it will able to allow User to select which phoneNumber to use, and handles multiple SIM cards, rather than us trying to guess which one is the primary SIM Card.

implementation "com.google.android.gms:play-services-auth:$play_service_auth_version"
fun main() {
    val googleApiClient = GoogleApiClient.Builder(context)
        .addApi(Auth.CREDENTIALS_API).build()

    val hintRequest = HintRequest.Builder()
        .setPhoneNumberIdentifierSupported(true)
        .build()

    val hintPickerIntent = Auth.CredentialsApi.getHintPickerIntent(
        googleApiClient, hintRequest
    )

    startIntentSenderForResult(
        hintPickerIntent.intentSender, REQUEST_PHONE_NUMBER, null, 0, 0, 0
    )
}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)
    when (requestCode) {
        REQUEST_PHONE_NUMBER -> {
            if (requestCode == Activity.RESULT_OK) {
                val credential = data?.getParcelableExtra<Credential>(Credential.EXTRA_KEY)
                val selectedPhoneNumber = credential?.id
            }
        }
    }
}

How to get filename without extension from file path in Ruby

require 'pathname'

Pathname.new('/opt/local/bin/ruby').basename
# => #<Pathname:ruby>

I haven't been a Windows user in a long time, but the Pathname rdoc says it has no issues with directory-name separators on Windows.

How to automatically insert a blank row after a group of data

This does exactly what you are asking, checks the rows, and inserts a blank empty row at each change in column A:

sub AddBlankRows()
'
dim iRow as integer, iCol as integer
dim oRng as range

set oRng=range("a1")

irow=oRng.row
icol=oRng.column

do 
'
if cells(irow+1, iCol)<>cells(irow,iCol) then
    cells(irow+1,iCol).entirerow.insert shift:=xldown
    irow=irow+2
else
    irow=irow+1
end if
'
loop while not cells (irow,iCol).text=""
'
end sub

I hope that gets you started, let us know!

Philip

How to use BeginInvoke C#

Action is a Type of Delegate provided by the .NET framework. The Action points to a method with no parameters and does not return a value.

() => is lambda expression syntax. Lambda expressions are not of Type Delegate. Invoke requires Delegate so Action can be used to wrap the lambda expression and provide the expected Type to Invoke()

Invoke causes said Action to execute on the thread that created the Control's window handle. Changing threads is often necessary to avoid Exceptions. For example, if one tries to set the Rtf property on a RichTextBox when an Invoke is necessary, without first calling Invoke, then a Cross-thread operation not valid exception will be thrown. Check Control.InvokeRequired before calling Invoke.

BeginInvoke is the Asynchronous version of Invoke. Asynchronous means the thread will not block the caller as opposed to a synchronous call which is blocking.

Writing numerical values on the plot with Matplotlib

You can use the annotate command to place text annotations at any x and y values you want. To place them exactly at the data points you could do this

import numpy
from matplotlib import pyplot

x = numpy.arange(10)
y = numpy.array([5,3,4,2,7,5,4,6,3,2])

fig = pyplot.figure()
ax = fig.add_subplot(111)
ax.set_ylim(0,10)
pyplot.plot(x,y)
for i,j in zip(x,y):
    ax.annotate(str(j),xy=(i,j))

pyplot.show()

If you want the annotations offset a little, you could change the annotate line to something like

ax.annotate(str(j),xy=(i,j+0.5))

How can I convert uppercase letters to lowercase in Notepad++

Ctrl+A , Ctrl+Shift+U

should do the trick!

Edit: Ctrl+U is the shortcut to be used to convert capital letters to lowercase (reverse scenario)

how to convert java string to Date object

    try 
    {  
      String datestr="06/27/2007";
      DateFormat formatter; 
      Date date; 
      formatter = new SimpleDateFormat("MM/dd/yyyy");
      date = (Date)formatter.parse(datestr);  
    } 
    catch (Exception e)
    {}

month is MM, minutes is mm..

What are the differences between a pointer variable and a reference variable in C++?

in simple words, we can say a reference is an alternative name for a variable whereas, a pointer is a variable that holds the address of another variable. e.g.

int a = 20;
int &r = a;
r = 40;  /* now the value of a is changed to 40 */

int b =20;
int *ptr;
ptr = &b;  /*assigns address of b to ptr not the value */

How to display my application's errors in JSF?

I tried this as a best guess, but no luck:

It looks right to me. Have you tried setting a message severity explicitly? Also I believe the ID needs to be the same as that of a component (i.e., you'd need to use newPassword1 or newPassword2, if those are your IDs, and not newPassword as you had in the example).

FacesContext.getCurrentInstance().addMessage("newPassword1", 
                    new FacesMessage(FacesMessage.SEVERITY_ERROR, "Error Message"));

Then use <h:message for="newPassword1" /> to display the error message on the JSF page.

MySQL: @variable vs. variable. What's the difference?

@variable is very useful if calling stored procedures from an application written in Java , Python etc. There are ocassions where variable values are created in the first call and needed in functions of subsequent calls.

Side-note on PL/SQL (Oracle)

The advantage can be seen in Oracle PL/SQL where these variables have 3 different scopes:

  • Function variable for which the scope ends when function exits.
  • Package body variables defined at the top of package and outside all functions whose scope is the session and visibility is package.
  • Package variable whose variable is session and visibility is global.

My Experience in PL/SQL

I have developed an architecture in which the complete code is written in PL/SQL. These are called from a middle-ware written in Java. There are two types of middle-ware. One to cater calls from a client which is also written in Java. The other other one to cater for calls from a browser. The client facility is implemented 100 percent in JavaScript. A command set is used instead of HTML and JavaScript for writing application in PL/SQL.

I have been looking for the same facility to port the codes written in PL/SQL to another database. The nearest one I have found is Postgres. But all the variables have function scope.

Opinion towards @ in MySQL

I am happy to see that at least this @ facility is there in MySQL. I don't think Oracle will build same facility available in PL/SQL to MySQL stored procedures since it may affect the sales of Oracle database.

Display Animated GIF

Nobody has mentioned the Ion or Glide library. they work very well.

It's easier to handle compared to a WebView.

How to read from standard input in the console?

I'm not sure what's wrong with the block

reader := bufio.NewReader(os.Stdin)
fmt.Print("Enter text: ")
text, _ := reader.ReadString('\n')
fmt.Println(text)

As it works on my machine. However, for the next block you need a pointer to the variables you're assigning the input to. Try replacing fmt.Scanln(text2) with fmt.Scanln(&text2). Don't use Sscanln, because it parses a string already in memory instead of from stdin. If you want to do something like what you were trying to do, replace it with fmt.Scanf("%s", &ln)

If this still doesn't work, your culprit might be some weird system settings or a buggy IDE.

Could not load NIB in bundle

Got this problem while transforming my old code from XCode 3x to XCode 4 and Solved it by just renaming wwwwwwww.xib into RootViewController.xib

Intellij Cannot resolve symbol on import

I found the source cause!

In my case, I add a jar file include some java source file, but I think the java source is bad, in Intellij Idea dependency library it add the source automatic, so in Editor the import is BAD, JUST remove the source code in "Project Structure" -> "Library", it works for me.

How to select a dropdown value in Selenium WebDriver using Java

First Import the package as :

import org.openqa.selenium.support.ui.Select;

then write in single line as:

new Select (driver.findElement(By.id("sampleid"))).selectByValue("SampleValue");

How to type a new line character in SQL Server Management Studio

Try using MS Access instead. Create a new file and select 'Project using existing data' template. This will create .adp file.

Then simply open your table and press Ctrl+Enter for new line.

Pasting from clipboard also works correctly.

How do I redirect to another webpage?

jQuery code to redirect a page or URL

First Way

Here is the jQuery code for redirecting a page. Since, I have put this code on the $(document).ready() function, it will execute as soon as the page is loaded.

_x000D_
_x000D_
var url = "http://stackoverflow.com";
$(location).attr('href',url);
_x000D_
_x000D_
_x000D_

You can even pass a URL directly to the attr() method, instead of using a variable.

Second Way

 window.location.href="http://stackoverflow.com";

You can also code like this (both are same internally):

window.location="http://stackoverflow.com";

If you are curious about the difference between window.location and window.location.href, then you can see that the latter one is setting href property explicitly, while the former one does it implicitly. Since window.location returns an object, which by default sets its .href property.

Third Way

There is another way to redirect a page using JavaScript, the replace() method of window.location object. You can pass a new URL to the replace() method, and it will simulate an HTTP redirect. By the way, remember that window.location.replace() method doesn't put the originating page in the session history, which may affect behavior of the back button. Sometime, it's what you want, so use it carefully.

_x000D_
_x000D_
// Doesn't put originating page in history
window.location.replace("http://stackoverflow.com");
_x000D_
_x000D_
_x000D_

Fourth Way

like attr() method (after jQuery 1.6 introduce)

_x000D_
_x000D_
var url = "http://stackoverflow.com";
$(location).prop('href', url);
_x000D_
_x000D_
_x000D_

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

Use file_put_contents()

file_put_contents('file.txt', 'bar');
echo file_get_contents('file.txt'); // bar
file_put_contents('file.txt', 'foo');
echo file_get_contents('file.txt'); // foo

Alternatively, if you're stuck with fopen() you can use the w or w+ modes:

'w' Open for writing only; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.

'w+' Open for reading and writing; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.

Relative path in HTML

You say your website is in http://localhost/mywebsite, and let's say that your image is inside a subfolder named pictures/:

Absolute path

If you use an absolute path, / would point to the root of the site, not the root of the document: localhost in your case. That's why you need to specify your document's folder in order to access the pictures folder:

"/mywebsite/pictures/picture.png"

And it would be the same as:

"http://localhost/mywebsite/pictures/picture.png"

Relative path

A relative path is always relative to the root of the document, so if your html is at the same level of the directory, you'd need to start the path directly with your picture's directory name:

"pictures/picture.png"

But there are other perks with relative paths:

dot-slash (./)

Dot (.) points to the same directory and the slash (/) gives access to it:

So this:

"pictures/picture.png"

Would be the same as this:

"./pictures/picture.png"

Double-dot-slash (../)

In this case, a double dot (..) points to the upper directory and likewise, the slash (/) gives you access to it. So if you wanted to access a picture that is on a directory one level above of the current directory your document is, your URL would look like this:

"../picture.png"

You can play around with them as much as you want, a little example would be this:

Let's say you're on directory A, and you want to access directory X.

- root
   |- a
      |- A
   |- b
   |- x
      |- X

Your URL would look either:

Absolute path

"/x/X/picture.png"

Or:

Relative path

"./../x/X/picture.png"

How to use Git Revert

git revert makes a new commit

git revert simply creates a new commit that is the opposite of an existing commit.

It leaves the files in the same state as if the commit that has been reverted never existed. For example, consider the following simple example:

$ cd /tmp/example
$ git init
Initialized empty Git repository in /tmp/example/.git/
$ echo "Initial text" > README.md
$ git add README.md
$ git commit -m "initial commit"
[master (root-commit) 3f7522e] initial commit
 1 file changed, 1 insertion(+)
 create mode 100644 README.md
$ echo "bad update" > README.md 
$ git commit -am "bad update"
[master a1b9870] bad update
 1 file changed, 1 insertion(+), 1 deletion(-)

In this example the commit history has two commits and the last one is a mistake. Using git revert:

$ git revert HEAD
[master 1db4eeb] Revert "bad update"
 1 file changed, 1 insertion(+), 1 deletion(-)

There will be 3 commits in the log:

$ git log --oneline
1db4eeb Revert "bad update"
a1b9870 bad update
3f7522e initial commit

So there is a consistent history of what has happened, yet the files are as if the bad update never occured:

cat README.md 
Initial text

It doesn't matter where in the history the commit to be reverted is (in the above example, the last commit is reverted - any commit can be reverted).

Closing questions

do you have to do something else after?

A git revert is just another commit, so e.g. push to the remote so that other users can pull/fetch/merge the changes and you're done.

Do you have to commit the changes revert made or does revert directly commit to the repo?

git revert is a commit - there are no extra steps assuming reverting a single commit is what you wanted to do.

Obviously you'll need to push again and probably announce to the team.

Indeed - if the remote is in an unstable state - communicating to the rest of the team that they need to pull to get the fix (the reverting commit) would be the right thing to do :).

How to install Python package from GitHub?

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

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

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

sudo python setup.py install

What is the copy-and-swap idiom?

Overview

Why do we need the copy-and-swap idiom?

Any class that manages a resource (a wrapper, like a smart pointer) needs to implement The Big Three. While the goals and implementation of the copy-constructor and destructor are straightforward, the copy-assignment operator is arguably the most nuanced and difficult. How should it be done? What pitfalls need to be avoided?

The copy-and-swap idiom is the solution, and elegantly assists the assignment operator in achieving two things: avoiding code duplication, and providing a strong exception guarantee.

How does it work?

Conceptually, it works by using the copy-constructor's functionality to create a local copy of the data, then takes the copied data with a swap function, swapping the old data with the new data. The temporary copy then destructs, taking the old data with it. We are left with a copy of the new data.

In order to use the copy-and-swap idiom, we need three things: a working copy-constructor, a working destructor (both are the basis of any wrapper, so should be complete anyway), and a swap function.

A swap function is a non-throwing function that swaps two objects of a class, member for member. We might be tempted to use std::swap instead of providing our own, but this would be impossible; std::swap uses the copy-constructor and copy-assignment operator within its implementation, and we'd ultimately be trying to define the assignment operator in terms of itself!

(Not only that, but unqualified calls to swap will use our custom swap operator, skipping over the unnecessary construction and destruction of our class that std::swap would entail.)


An in-depth explanation

The goal

Let's consider a concrete case. We want to manage, in an otherwise useless class, a dynamic array. We start with a working constructor, copy-constructor, and destructor:

#include <algorithm> // std::copy
#include <cstddef> // std::size_t

class dumb_array
{
public:
    // (default) constructor
    dumb_array(std::size_t size = 0)
        : mSize(size),
          mArray(mSize ? new int[mSize]() : nullptr)
    {
    }

    // copy-constructor
    dumb_array(const dumb_array& other)
        : mSize(other.mSize),
          mArray(mSize ? new int[mSize] : nullptr),
    {
        // note that this is non-throwing, because of the data
        // types being used; more attention to detail with regards
        // to exceptions must be given in a more general case, however
        std::copy(other.mArray, other.mArray + mSize, mArray);
    }

    // destructor
    ~dumb_array()
    {
        delete [] mArray;
    }

private:
    std::size_t mSize;
    int* mArray;
};

This class almost manages the array successfully, but it needs operator= to work correctly.

A failed solution

Here's how a naive implementation might look:

// the hard part
dumb_array& operator=(const dumb_array& other)
{
    if (this != &other) // (1)
    {
        // get rid of the old data...
        delete [] mArray; // (2)
        mArray = nullptr; // (2) *(see footnote for rationale)

        // ...and put in the new
        mSize = other.mSize; // (3)
        mArray = mSize ? new int[mSize] : nullptr; // (3)
        std::copy(other.mArray, other.mArray + mSize, mArray); // (3)
    }

    return *this;
}

And we say we're finished; this now manages an array, without leaks. However, it suffers from three problems, marked sequentially in the code as (n).

  1. The first is the self-assignment test. This check serves two purposes: it's an easy way to prevent us from running needless code on self-assignment, and it protects us from subtle bugs (such as deleting the array only to try and copy it). But in all other cases it merely serves to slow the program down, and act as noise in the code; self-assignment rarely occurs, so most of the time this check is a waste. It would be better if the operator could work properly without it.

  2. The second is that it only provides a basic exception guarantee. If new int[mSize] fails, *this will have been modified. (Namely, the size is wrong and the data is gone!) For a strong exception guarantee, it would need to be something akin to:

    dumb_array& operator=(const dumb_array& other)
    {
        if (this != &other) // (1)
        {
            // get the new data ready before we replace the old
            std::size_t newSize = other.mSize;
            int* newArray = newSize ? new int[newSize]() : nullptr; // (3)
            std::copy(other.mArray, other.mArray + newSize, newArray); // (3)
    
            // replace the old data (all are non-throwing)
            delete [] mArray;
            mSize = newSize;
            mArray = newArray;
        }
    
        return *this;
    }
    
  3. The code has expanded! Which leads us to the third problem: code duplication. Our assignment operator effectively duplicates all the code we've already written elsewhere, and that's a terrible thing.

In our case, the core of it is only two lines (the allocation and the copy), but with more complex resources this code bloat can be quite a hassle. We should strive to never repeat ourselves.

(One might wonder: if this much code is needed to manage one resource correctly, what if my class manages more than one? While this may seem to be a valid concern, and indeed it requires non-trivial try/catch clauses, this is a non-issue. That's because a class should manage one resource only!)

A successful solution

As mentioned, the copy-and-swap idiom will fix all these issues. But right now, we have all the requirements except one: a swap function. While The Rule of Three successfully entails the existence of our copy-constructor, assignment operator, and destructor, it should really be called "The Big Three and A Half": any time your class manages a resource it also makes sense to provide a swap function.

We need to add swap functionality to our class, and we do that as follows†:

class dumb_array
{
public:
    // ...

    friend void swap(dumb_array& first, dumb_array& second) // nothrow
    {
        // enable ADL (not necessary in our case, but good practice)
        using std::swap;

        // by swapping the members of two objects,
        // the two objects are effectively swapped
        swap(first.mSize, second.mSize);
        swap(first.mArray, second.mArray);
    }

    // ...
};

(Here is the explanation why public friend swap.) Now not only can we swap our dumb_array's, but swaps in general can be more efficient; it merely swaps pointers and sizes, rather than allocating and copying entire arrays. Aside from this bonus in functionality and efficiency, we are now ready to implement the copy-and-swap idiom.

Without further ado, our assignment operator is:

dumb_array& operator=(dumb_array other) // (1)
{
    swap(*this, other); // (2)

    return *this;
}

And that's it! With one fell swoop, all three problems are elegantly tackled at once.

Why does it work?

We first notice an important choice: the parameter argument is taken by-value. While one could just as easily do the following (and indeed, many naive implementations of the idiom do):

dumb_array& operator=(const dumb_array& other)
{
    dumb_array temp(other);
    swap(*this, temp);

    return *this;
}

We lose an important optimization opportunity. Not only that, but this choice is critical in C++11, which is discussed later. (On a general note, a remarkably useful guideline is as follows: if you're going to make a copy of something in a function, let the compiler do it in the parameter list.‡)

Either way, this method of obtaining our resource is the key to eliminating code duplication: we get to use the code from the copy-constructor to make the copy, and never need to repeat any bit of it. Now that the copy is made, we are ready to swap.

Observe that upon entering the function that all the new data is already allocated, copied, and ready to be used. This is what gives us a strong exception guarantee for free: we won't even enter the function if construction of the copy fails, and it's therefore not possible to alter the state of *this. (What we did manually before for a strong exception guarantee, the compiler is doing for us now; how kind.)

At this point we are home-free, because swap is non-throwing. We swap our current data with the copied data, safely altering our state, and the old data gets put into the temporary. The old data is then released when the function returns. (Where upon the parameter's scope ends and its destructor is called.)

Because the idiom repeats no code, we cannot introduce bugs within the operator. Note that this means we are rid of the need for a self-assignment check, allowing a single uniform implementation of operator=. (Additionally, we no longer have a performance penalty on non-self-assignments.)

And that is the copy-and-swap idiom.

What about C++11?

The next version of C++, C++11, makes one very important change to how we manage resources: the Rule of Three is now The Rule of Four (and a half). Why? Because not only do we need to be able to copy-construct our resource, we need to move-construct it as well.

Luckily for us, this is easy:

class dumb_array
{
public:
    // ...

    // move constructor
    dumb_array(dumb_array&& other) noexcept ††
        : dumb_array() // initialize via default constructor, C++11 only
    {
        swap(*this, other);
    }

    // ...
};

What's going on here? Recall the goal of move-construction: to take the resources from another instance of the class, leaving it in a state guaranteed to be assignable and destructible.

So what we've done is simple: initialize via the default constructor (a C++11 feature), then swap with other; we know a default constructed instance of our class can safely be assigned and destructed, so we know other will be able to do the same, after swapping.

(Note that some compilers do not support constructor delegation; in this case, we have to manually default construct the class. This is an unfortunate but luckily trivial task.)

Why does that work?

That is the only change we need to make to our class, so why does it work? Remember the ever-important decision we made to make the parameter a value and not a reference:

dumb_array& operator=(dumb_array other); // (1)

Now, if other is being initialized with an rvalue, it will be move-constructed. Perfect. In the same way C++03 let us re-use our copy-constructor functionality by taking the argument by-value, C++11 will automatically pick the move-constructor when appropriate as well. (And, of course, as mentioned in previously linked article, the copying/moving of the value may simply be elided altogether.)

And so concludes the copy-and-swap idiom.


Footnotes

*Why do we set mArray to null? Because if any further code in the operator throws, the destructor of dumb_array might be called; and if that happens without setting it to null, we attempt to delete memory that's already been deleted! We avoid this by setting it to null, as deleting null is a no-operation.

†There are other claims that we should specialize std::swap for our type, provide an in-class swap along-side a free-function swap, etc. But this is all unnecessary: any proper use of swap will be through an unqualified call, and our function will be found through ADL. One function will do.

‡The reason is simple: once you have the resource to yourself, you may swap and/or move it (C++11) anywhere it needs to be. And by making the copy in the parameter list, you maximize optimization.

††The move constructor should generally be noexcept, otherwise some code (e.g. std::vector resizing logic) will use the copy constructor even when a move would make sense. Of course, only mark it noexcept if the code inside doesn't throw exceptions.

jQuery detect if textarea is empty

To find out if the textarea is empty we have a look at the textarea text content and if there is one sinlge character to be found it is not empty.

Try:

if ($(#textareaid).get(0).textContent.length == 0){
  // action
}
//or
if (document.getElmentById(textareaid).textContent.length == 0){
  // action
}

$(#textareaid) gets us the textarea jQuery object. $(#textareaid).get(0) gets us the dom node. We could also use document.getElmentById(textareaid) without the use of jQuery. .textContent gets us the textContent of that dom element. With .length we can see if there are any characters present. So the textarea is empty in case that there are no characters inside.

Does --disable-web-security Work In Chrome Anymore?

If you want to automate this: Kill chrome from task Manager First. In Windows - Right Click (or Shift+right click, in-case of taskbar) on Chrome Icon. Select Properties. In "Target" text-box, add --disable-web-security flag.

So text in text-box should look like

C:\Users\njadhav\AppData\Local\Google\Chrome SxS\Application\chrome.exe" --disable-web-security

Click Ok and launch chrome.

Current date and time as string

you can use asctime() function of time.h to get a string simply .

time_t _tm =time(NULL );

struct tm * curtime = localtime ( &_tm );
cout<<"The current date/time is:"<<asctime(curtime);

Sample output:

The current date/time is:Fri Oct 16 13:37:30 2015

Convert String to double in Java

String s = "12.34";
double num = Double.valueOf(s);

Mapping many-to-many association table with extra column(s)

As said before, with JPA, in order to have the chance to have extra columns, you need to use two OneToMany associations, instead of a single ManyToMany relationship. You can also add a column with autogenerated values; this way, it can work as the primary key of the table, if useful.

For instance, the implementation code of the extra class should look like that:

@Entity
@Table(name = "USER_SERVICES")
public class UserService{

    // example of auto-generated ID
    @Id
    @Column(name = "USER_SERVICES_ID", nullable = false)
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long userServiceID;



    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "USER_ID")
    private User user;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "SERVICE_ID")
    private Service service;



    // example of extra column
    @Column(name="VISIBILITY")    
    private boolean visibility;



    public long getUserServiceID() {
        return userServiceID;
    }


    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public Service getService() {
        return service;
    }

    public void setService(Service service) {
        this.service = service;
    }

    public boolean getVisibility() {
        return visibility;
    }

    public void setVisibility(boolean visibility) {
        this.visibility = visibility;
    }

}

Vertical align in bootstrap table

Based on what you have provided your CSS selector is not specific enough to override the CSS rules defined by Bootstrap.

Try this:

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

In Boostrap 4, this can be achieved with the .align-middle Vertical Alignment utility class.

<td class="align-middle">Text</td>

How to calculate distance between two locations using their longitude and latitude value

Use the below method for calculating the distance of two different locations.

public double getKilometers(double lat1, double long1, double lat2, double long2) {
 double PI_RAD = Math.PI / 180.0;
 double phi1 = lat1 * PI_RAD;
 double phi2 = lat2 * PI_RAD;
 double lam1 = long1 * PI_RAD;
 double lam2 = long2 * PI_RAD;

return 6371.01 * acos(sin(phi1) * sin(phi2) + cos(phi1) * cos(phi2) * cos(lam2 - lam1));}

How to convert list data into json in java

i wrote my own function to return list of object for populate combo box :

public static String getJSONList(java.util.List<Object> list,String kelas,String name, String label) {
        try {
            Object[] args={};
            Class cl = Class.forName(kelas);
            Method getName = cl.getMethod(name, null);
            Method getLabel = cl.getMethod(label, null);
            String json="[";
            for (int i = 0; i < list.size(); i++) {
            Object o = list.get(i);
            if(i>0){
                json+=",";
            }
            json+="{\"label\":\""+getLabel.invoke(o,args)+"\",\"name\":\""+getName.invoke(o,args)+"\"}";
            //System.out.println("Object = " + i+" -> "+o.getNumber());
            }
            json+="]";
            return json;
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(JSONHelper.class.getName()).log(Level.SEVERE, null, ex);
        } catch (Exception ex) {
            System.out.println("Error in get JSON List");
            ex.printStackTrace();
        }
        return "";
    }

and call it from anywhere like :

String toreturn=JSONHelper.getJSONList(list, "com.bean.Contact", "getContactID", "getNumber");

How do I make bootstrap table rows clickable?

I show you my example with modal windows...you create your modal and give it an id then In your table you have tr section, just ad the first line you see below (don't forget to set the on the first row like this

<tr onclick="input" data-toggle="modal" href="#the name for my modal windows" >
 <td><label>Some value here</label></td>
</tr>                                                                                                                                                                                   

Eclipse EGit Checkout conflict with files: - EGit doesn't want to continue

This is the way I solved my problem:

  1. Right click the folder that has uncommitted changes on your local
  2. Click Team > Advanced > Assume Unchanged
  3. Pull from master.

UPDATE:

As Hugo Zuleta rightly pointed out, you should be careful while applying this. He says that it might end up saying the branch is up to date, but the changes aren't shown, resulting in desync from the branch.

What is the Regular Expression For "Not Whitespace and Not a hyphen"

In Java:

    String regex = "[^-\\s]";

    System.out.println("-".matches(regex)); // prints "false"
    System.out.println(" ".matches(regex)); // prints "false"
    System.out.println("+".matches(regex)); // prints "true"

The regex [^-\s] works as expected. [^\s-] also works.

See also

What does it mean by command cd /d %~dp0 in Windows

Let's dissect it. There are three parts:

  1. cd -- This is change directory command.
  2. /d -- This switch makes cd change both drive and directory at once. Without it you would have to do cd %~d0 & cd %~p0. (%~d0 Changs active drive, cd %~p0 change the directory).
  3. %~dp0 -- This can be dissected further into three parts:
    1. %0 -- This represents zeroth parameter of your batch script. It expands into the name of the batch file itself.
    2. %~0 -- The ~ there strips double quotes (") around the expanded argument.
    3. %dp0 -- The d and p there are modifiers of the expansion. The d forces addition of a drive letter and the p adds full path.

How to check whether a string contains a substring in Ruby

A more succinct idiom than the accepted answer above that's available in Rails (from 3.1.0 and above) is .in?:

my_string = "abcdefg"
if "cde".in? my_string
  puts "'cde' is in the String."
  puts "i.e. String includes 'cde'"
end

I also think it's more readable.

See the in? documentation for more information.

Note again that it's only available in Rails, and not pure Ruby.

What's "tools:context" in Android layout files?

That attribute is basically the persistence for the "Associated Activity" selection above the layout. At runtime, a layout is always associated with an activity. It can of course be associated with more than one, but at least one. In the tool, we need to know about this mapping (which at runtime happens in the other direction; an activity can call setContentView(layout) to display a layout) in order to drive certain features.

Right now, we're using it for one thing only: Picking the right theme to show for a layout (since the manifest file can register themes to use for an activity, and once we know the activity associated with the layout, we can pick the right theme to show for the layout). In the future, we'll use this to drive additional features - such as rendering the action bar (which is associated with the activity), a place to add onClick handlers, etc.

The reason this is a tools: namespace attribute is that this is only a designtime mapping for use by the tool. The layout itself can be used by multiple activities/fragments etc. We just want to give you a way to pick a designtime binding such that we can for example show the right theme; you can change it at any time, just like you can change our listview and fragment bindings, etc.

(Here's the full changeset which has more details on this)

And yeah, the link Nikolay listed above shows how the new configuration chooser looks and works

One more thing: The "tools" namespace is special. The android packaging tool knows to ignore it, so none of those attributes will be packaged into the APK. We're using it for extra metadata in the layout. It's also where for example the attributes to suppress lint warnings are stored -- as tools:ignore.

How to pass arguments to Shell Script through docker run

Another option...

To make this works

docker run -d --rm $IMG_NAME "bash:command1&&command2&&command3"

in dockerfile

ENTRYPOINT ["/entrypoint.sh"]

in entrypoint.sh

#!/bin/sh

entrypoint_params=$1
printf "==>[entrypoint.sh] %s\n" "entry_point_param is $entrypoint_params"

PARAM1=$(echo $entrypoint_params | cut -d':' -f1) # output is 1 must be 'bash' it     will be tested    
PARAM2=$(echo $entrypoint_params | cut -d':' -f2) # the real command separated by     &&

printf "==>[entrypoint.sh] %s\n" "PARAM1=$PARAM1"
printf "==>[entrypoint.sh] %s\n" "PARAM2=$PARAM2"

if [ "$PARAM1" = "bash" ];
then
    printf "==>[entrypoint.sh] %s\n" "about to running $PARAM2 command"
    echo $PARAM2 | tr '&&' '\n' | while read cmd; do
        $cmd
    done    
fi

How to check list A contains any value from list B?

I use this to count:

int cnt = 0;

foreach (var lA in listA)
{
    if (listB.Contains(lA))
    {
        cnt++;
    }
}

How to use "raise" keyword in Python

It's used for raising errors.

if something:
    raise Exception('My error!')

Some examples here

Best place to insert the Google Analytics code

Yes, it is recommended to put the GA code in the footer anyway, as the page shouldnt count as a page visit until its read all the markup.

jQuery ID starts with

Here you go:

$('td[id^="' + value +'"]')

so if the value is for instance 'foo', then the selector will be 'td[id^="foo"]'.

Note that the quotes are mandatory: [id^="...."].

Source: http://api.jquery.com/attribute-starts-with-selector/

Auto-loading lib files in Rails 4

I think this may solve your problem:

  1. in config/application.rb:

    config.autoload_paths << Rails.root.join('lib')
    

    and keep the right naming convention in lib.

    in lib/foo.rb:

    class Foo
    end
    

    in lib/foo/bar.rb:

    class Foo::Bar
    end
    
  2. if you really wanna do some monkey patches in file like lib/extensions.rb, you may manually require it:

    in config/initializers/require.rb:

    require "#{Rails.root}/lib/extensions" 
    

P.S.

How to load a tsv file into a Pandas DataFrame?

Use read_table(filepath). The default separator is tab

How to install SQL Server Management Studio 2008 component only

The accepted answer was correct up until July 2011. To get the latest version, including the Service Pack you should find the latest version as described here:

For example, if you check the SP2 CTP and SP1, you'll find the latest version of SQL Server Management Studio under SP1:

Download the 32-bit (x86) or 64-bit (x64) version of the SQLManagementStudio*.exe files as appropriate and install it. You can find out whether your system is 32-bit or 64-bit by right clicking Computer, selecting Properties and looking at the System Type.

Although you could apply the service pack to the base version that results from following the accepted answer, it's easier to just download the latest version of SQL Server Management Studio and simply install it in one step.

Any way (or shortcut) to auto import the classes in IntelliJ IDEA like in Eclipse?

Use control+option+O to auto-import the package or auto remove unused packages on MacOS

Using the AND and NOT Operator in Python

It's called and and or in Python.

Using Jquery Ajax to retrieve data from Mysql

Please make sure your $row[1] , $row[2] contains correct value, we do assume here that 1 = Name , and 2 here is your Address field ?

Assuming you have correctly fetched your records from your Records.php, You can do something like this:

$(document).ready(function()
{
    $('#getRecords').click(function()
    {
        var response = '';
        $.ajax({ type: 'POST',   
                 url: "Records.php",   
                 async: false,
                 success : function(text){
                               $('#table1').html(text);
                           }
           });
    });

}

In your HTML

<table id="table1"> 
    //Let jQuery AJAX Change This Text  
</table>
<button id='getRecords'>Get Records</button>

A little note:

Try learing PDO http://php.net/manual/en/class.pdo.php since mysql_* functions are no longer encouraged..

SHA1 vs md5 vs SHA256: which to use for a PHP login?

Use SHA256. It is not perfect, as SHA512 would be ideal for a fast hash, but out of the options, its the definite choice. As per any hashing technology, be sure to salt the hash for added security.

As an added note, FRKT, please show me where someone can easily crack a salted SHA256 hash? I am truly very interested to see this.

Important Edit:

Moving forward please use bcrypt as a hardened hash. More information can be found here.


Edit on Salting:

Use a random number, or random byte stream etc. You can use the unique field of the record in your database as the salt too, this way the salt is different per user.

How to plot an array in python?

if you give a 2D array to the plot function of matplotlib it will assume the columns to be lines:

If x and/or y is 2-dimensional, then the corresponding columns will be plotted.

In your case your shape is not accepted (100, 1, 1, 8000). As so you can using numpy squeeze to solve the problem quickly:

np.squeez doc: Remove single-dimensional entries from the shape of an array.

import numpy as np
import matplotlib.pyplot as plt

data = np.random.randint(3, 7, (10, 1, 1, 80))
newdata = np.squeeze(data) # Shape is now: (10, 80)
plt.plot(newdata) # plotting by columns
plt.show()

But notice that 100 sets of 80 000 points is a lot of data for matplotlib. I would recommend that you look for an alternative. The result of the code example (run in Jupyter) is:

Jupyter matplotlib plot

Find the most popular element in int[] array

Mine Linear O(N)

Using map to save all the differents elements found in the array and saving the number of times ocurred, then just getting the max from the map.

import java.util.HashMap;
import java.util.Map;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
import java.util.stream.IntStream;

public class MosftOftenNumber {

    // for O(N) + map O(1) = O(N) 
    public static int mostOftenNumber(int[] a)
    {
        final Map m = new HashMap<Integer,Integer>();
        int max = 0;
        int element = 0;

        for (int i=0; i<a.length; i++){
            //initializing value for the map the value will have the counter of each element
            //first time one new number its found will be initialize with zero 
            if (m.get(a[i]) == null)
                m.put(a[i],0);

            //save each value from the array and increment the count each time its found
            m.put(a[i] , (Integer) m.get(a[i]) + 1);

            //check the value from each element and comparing with max
            if ( (Integer) m.get(a[i]) > max){
                max = (Integer) m.get(a[i]);
                element = a[i];
            }

        }
        System.out.println("Times repeated: " + max);
        return element;
    }

    public static int mostOftenNumberWithLambdas(int[] a)
    {
        Integer max = IntStream.of(a).boxed().max(Integer::compareTo).get();
        Integer coumtMax = Math.toIntExact(IntStream.of(a).boxed().filter(number -> number.equals(max)).count());
        System.out.println("Times repeated: " + coumtMax);
        return max;
    }

    public static void main(String args[]) {
//      int[] array = {1,1,2,1,1};
//      int[] array = {2,2,1,2,2};
        int[] array = {1,2,3,4,5,6,7,7,7,7};
        System.out.println("Most often number with loops: " + mostOftenNumber(array));
        System.out.println("Most often number with lambdas: " + mostOftenNumberWithLambdas(array));
    }

}

APR based Apache Tomcat Native library was not found on the java.library.path?

For Ubntu Users

 1. Install compilers
    #sudo apt-get install make
    #sudo apt-get install gcc

    2. Install openssl and development libraries
    #sudo apt-get install openssl
    #sudo apt-get install libssl-dev
    3. Install the APR package (Downloaded from http://apr.apache.org/)

    #tar -xzf apr-1.4.6.tar.gz
    #cd apr-1.4.6/
    #sudo ./configure
    #sudo make
    #sudo make install

    You should see the compiled file as
    /usr/local/apr/lib/libapr-1.a

    4. Download, compile and install Tomcat Native sourse package
    tomcat-native-1.1.27-src.tar.gz

    Extract the archive into some folder

    #tar -xzf tomcat-native-1.1.27-src.tar.gz
    #cd tomcat-native-1.1.27-src/jni/native
    #JAVA_HOME=/usr/lib/jvm/jdk1.7.0_21/
    #sudo ./configure --with-apr=/usr/local/apr --with-java-home=$JAVA_HOME
    #sudo make
    #sudo make install

    Now I have compiled Tomcat Native library in /usr/local/apr/libtcnative-1.so.0.1.27 and symbolic link file /usr/local/apr/@libtcnative-1.so pointed to the library

    5. Create or edit the $CATALINA_HOME/bin/setenv.sh file with following lines :
    export LD_LIBRARY_PATH='$LD_LIBRARY_PATH:/usr/local/apr/lib'

    6. Restart tomcat and see the desired result:

How to add an image to a JPanel?

Fred Haslam's way works fine. I had trouble with the filepath though, since I want to reference an image within my jar. To do this, I used:

BufferedImage wPic = ImageIO.read(this.getClass().getResource("snow.png"));
JLabel wIcon = new JLabel(new ImageIcon(wPic));

Since I only have a finite number (about 10) images that I need to load using this method, it works quite well. It gets file without having to have the correct relative filepath.

Is calculating an MD5 hash less CPU intensive than SHA family functions?

sha1sum is quite a bit faster on Power9 than md5sum

$ uname -mov
#1 SMP Mon May 13 12:16:08 EDT 2019 ppc64le GNU/Linux

$ cat /proc/cpuinfo
processor       : 0
cpu             : POWER9, altivec supported
clock           : 2166.000000MHz
revision        : 2.2 (pvr 004e 1202)

$ ls -l linux-master.tar
-rw-rw-r-- 1 x x 829685760 Jan 29 14:30 linux-master.tar

$ time sha1sum linux-master.tar
10fbf911e254c4fe8e5eb2e605c6c02d29a88563  linux-master.tar

real    0m1.685s
user    0m1.528s
sys     0m0.156s

$ time md5sum linux-master.tar
d476375abacda064ae437a683c537ec4  linux-master.tar

real    0m2.942s
user    0m2.806s
sys     0m0.136s

$ time sum linux-master.tar
36928 810240

real    0m2.186s
user    0m1.917s
sys     0m0.268s

How to change the buttons text using javascript

If the HTMLElement is input[type='button'], input[type='submit'], etc.

<input id="ShowButton" type="button" value="Show">
<input id="ShowButton" type="submit" value="Show">

change it using this code:

document.querySelector('#ShowButton').value = 'Hide';

If, the HTMLElement is button[type='button'], button[type='submit'], etc:

<button id="ShowButton" type="button">Show</button>
<button id="ShowButton" type="submit">Show</button>

change it using any of these methods,

document.querySelector('#ShowButton').innerHTML = 'Hide';
document.querySelector('#ShowButton').innerText = 'Hide';
document.querySelector('#ShowButton').textContent = 'Hide';

Please note that

  • input is an empty tag and cannot have innerHTML, innerText or textContent
  • button is a container tag and can have innerHTML, innerText or textContent

Ignore this answer if you ain't using asp.net-web-forms, asp.net-ajax and rad-grid

You must use value instead of innerHTML.

Try this.

document.getElementById("ShowButton").value= "Hide Filter";

And since you are running the button at server the ID may get mangled in the framework. I so, try

document.getElementById('<%=ShowButton.ClientID %>').value= "Hide Filter";

Another better way to do this is like this.

On markup, change your onclick attribute like this. onclick="showFilterItem(this)"

Now use it like this

function showFilterItem(objButton) {
    if (filterstatus == 0) {
        filterstatus = 1;
        $find('<%=FileAdminRadGrid.ClientID %>').get_masterTableView().showFilterItem();
        objButton.value = "Hide Filter";
    }
    else {
        filterstatus = 0;
        $find('<%=FileAdminRadGrid.ClientID %>').get_masterTableView().hideFilterItem();
        objButton.value = "Show filter";
    }
}

Oracle: SQL query that returns rows with only numeric values

You can use following command -

LENGTH(TRIM(TRANSLATE(string1, '+-.0123456789', '')))

This will return NULL if your string1 is Numeric

your query would be -

select * from tablename 
where LENGTH(TRIM(TRANSLATE(X, '+-.0123456789', ''))) is null

Given two directory trees, how can I find out which files differ by content?

You can also use Rsync and find. For find:

find $FOLDER -type f | cut -d/ -f2- | sort > /tmp/file_list_$FOLDER

But files with the same names and in the same subfolders, but with different content, will not be shown in the lists.

If you are a fan of GUI, you may check Meld that @Alexander mentioned. It works fine in both windows and linux.

Stop jQuery .load response from being cached

I noticed that if some servers (like Apache2) are not configured to specifically allow or deny any "caching", then the server may by default send a "cached" response, even if you set the HTTP headers to "no-cache". So make sure that your server is not "caching" anything before it sents a response:

In the case of Apache2 you have to

1) edit the "disk_cache.conf" file - to disable cache add "CacheDisable /local_files" directive

2) load mod_cache modules (On Ubuntu "sudo a2enmod cache" and "sudo a2enmod disk_cache")

3) restart the Apache2 (Ubuntu "sudo service apache2 restart");

This should do the trick disabling cache on the servers side. Cheers! :)

Role/Purpose of ContextLoaderListener in Spring?

ContextLoaderListner is a Servlet listener that loads all the different configuration files (service layer configuration, persistence layer configuration etc) into single spring application context.

This helps to split spring configurations across multiple XML files.

Once the context files are loaded, Spring creates a WebApplicationContext object based on the bean definition and stores it in the ServletContext of your web application.

How to have EditText with border in Android Lollipop

You can use a drawable. Create a drawable layout file in your drawable folder. Paste this code. You can as well modify it - border.xml.

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<stroke
    android:width="1dp"
    android:color="@color/divider" />
<solid
    android:color="#00FFFFFF"
    android:paddingLeft="10dp"
    android:paddingTop="10dp"/>
<padding
    android:left="10dp"
    android:top="10dp"
    android:right="10dp"
    android:bottom="10dp" />
</shape>

in your EditText view, add

android:background="@drawable/border"

Catching nullpointerexception in Java

As stated already within another answer it is not recommended to catch a NullPointerException. However you definitely could catch it, like the following example shows.

public class Testclass{

    public static void main(String[] args) {
        try {
            doSomething();
        } catch (NullPointerException e) {
            System.out.print("Caught the NullPointerException");
        }
    }

    public static void doSomething() {
        String nullString = null;
        nullString.endsWith("test");
    }
}

Although a NPE can be caught you definitely shouldn't do that but fix the initial issue, which is the Check_Circular method.

How can I replace non-printable Unicode characters in Java?

I have used this simple function for this:

private static Pattern pattern = Pattern.compile("[^ -~]");
private static String cleanTheText(String text) {
    Matcher matcher = pattern.matcher(text);
    if ( matcher.find() ) {
        text = text.replace(matcher.group(0), "");
    }
    return text;
}

Hope this is useful.

Setting default permissions for newly created files and sub-directories under a directory in Linux?

To get the right ownership, you can set the group setuid bit on the directory with

chmod g+rwxs dirname

This will ensure that files created in the directory are owned by the group. You should then make sure everyone runs with umask 002 or 007 or something of that nature---this is why Debian and many other linux systems are configured with per-user groups by default.

I don't know of a way to force the permissions you want if the user's umask is too strong.

Re-ordering columns in pandas dataframe based on column name

One use-case is that you have named (some of) your columns with some prefix, and you want the columns sorted with those prefixes all together and in some particular order (not alphabetical).

For example, you might start all of your features with Ft_, labels with Lbl_, etc, and you want all unprefixed columns first, then all features, then the label. You can do this with the following function (I will note a possible efficiency problem using sum to reduce lists, but this isn't an issue unless you have a LOT of columns, which I do not):

def sortedcols(df, groups = ['Ft_', 'Lbl_'] ):
    return df[ sum([list(filter(re.compile(r).search, list(df.columns).copy())) for r in (lambda l: ['^(?!(%s))' % '|'.join(l)] + ['^%s' % i  for i in l ] )(groups)   ], [])  ]

Creating an empty bitmap and drawing though canvas in Android

This is probably simpler than you're thinking:

int w = WIDTH_PX, h = HEIGHT_PX;

Bitmap.Config conf = Bitmap.Config.ARGB_8888; // see other conf types
Bitmap bmp = Bitmap.createBitmap(w, h, conf); // this creates a MUTABLE bitmap
Canvas canvas = new Canvas(bmp);

// ready to draw on that bitmap through that canvas

Here's a series of tutorials I've found on the topic: Drawing with Canvas Series

Get most recent row for given ID

Use the aggregate MAX(signin) grouped by id. This will list the most recent signin for each id.

SELECT 
 id, 
 MAX(signin) AS most_recent_signin
FROM tbl
GROUP BY id

To get the whole single record, perform an INNER JOIN against a subquery which returns only the MAX(signin) per id.

SELECT 
  tbl.id,
  signin,
  signout
FROM tbl
  INNER JOIN (
    SELECT id, MAX(signin) AS maxsign FROM tbl GROUP BY id
  ) ms ON tbl.id = ms.id AND signin = maxsign
WHERE tbl.id=1

When and why do I need to use cin.ignore() in C++?

Ignore function is used to skip(discard/throw away) characters in the input stream. Ignore file is associated with the file istream. Consider the function below ex: cin.ignore(120,'/n'); the particular function skips the next 120 input character or to skip the characters until a newline character is read.

AngularJS - Passing data between pages

If you only need to share data between views/scopes/controllers, the easiest way is to store it in $rootScope. However, if you need a shared function, it is better to define a service to do that.

Why is my xlabel cut off in my matplotlib plot?

plt.autoscale() worked for me.

HTML span align center not working?

On top of all the other explanations, I believe you're using equal "=" sign, instead of colon ":":

<span style="border:1px solid red;text-align=center">

It should be:

<span style="border:1px solid red;text-align:center">

Unable to install pyodbc on Linux

Adding one more answer on this question. For Linux Debian Stretch release you would need to install the following dependencies:

apt-get update
apt-get install g++
apt-get install unixodbc-dev
pip install pyodbc

EPPlus - Read Excel Table

Below code will read excel data into a datatable, which is converted to list of datarows.

if (FileUpload1.HasFile)
{
    if (Path.GetExtension(FileUpload1.FileName) == ".xlsx")
    {
        Stream fs = FileUpload1.FileContent;
        ExcelPackage package = new ExcelPackage(fs);
        DataTable dt = new DataTable();
        dt= package.ToDataTable();
        List<DataRow> listOfRows = new List<DataRow>();
        listOfRows = dt.AsEnumerable().ToList();

    }
}
using OfficeOpenXml;
using System.Data;
using System.Linq;

 public static class ExcelPackageExtensions
    {
        public static DataTable ToDataTable(this ExcelPackage package)
        {
            ExcelWorksheet workSheet = package.Workbook.Worksheets.First();
            DataTable table = new DataTable();
            foreach (var firstRowCell in workSheet.Cells[1, 1, 1, workSheet.Dimension.End.Column])
            {
                table.Columns.Add(firstRowCell.Text);
            }

            for (var rowNumber = 2; rowNumber <= workSheet.Dimension.End.Row; rowNumber++)
            {
                var row = workSheet.Cells[rowNumber, 1, rowNumber, workSheet.Dimension.End.Column];
                var newRow = table.NewRow();
                foreach (var cell in row)
                {
                    newRow[cell.Start.Column - 1] = cell.Text;
                }
                table.Rows.Add(newRow);
            }
            return table;
        }

    }

Making a button invisible by clicking another button in HTML

  1. getElementById returns a single object for which you can specify the style.So, the above explanation is correct.

  2. getElementsByTagName returns multiple objects(array of objects and properties) for which we cannot apply the style directly.

C++ - how to find the length of an integer

How about (works also for 0 and negatives):

int digits( int x ) { 
    return ( (bool) x * (int) log10( abs( x ) ) + 1 );
}

Understanding Apache's access log

And what does "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.19 (KHTML, like Gecko) Chrome/18.0.1025.5 Safari/535.19" means ?

This is the value of User-Agent, the browser identification string.

For this reason, most Web browsers use a User-Agent string value as follows:

Mozilla/[version] ([system and browser information]) [platform] ([platform details]) [extensions]. For example, Safari on the iPad has used the following:

Mozilla/5.0 (iPad; U; CPU OS 3_2_1 like Mac OS X; en-us) AppleWebKit/531.21.10 (KHTML, like Gecko) Mobile/7B405 The components of this string are as follows:

Mozilla/5.0: Previously used to indicate compatibility with the Mozilla rendering engine. (iPad; U; CPU OS 3_2_1 like Mac OS X; en-us): Details of the system in which the browser is running. AppleWebKit/531.21.10: The platform the browser uses. (KHTML, like Gecko): Browser platform details. Mobile/7B405: This is used by the browser to indicate specific enhancements that are available directly in the browser or through third parties. An example of this is Microsoft Live Meeting which registers an extension so that the Live Meeting service knows if the software is already installed, which means it can provide a streamlined experience to joining meetings.

This value will be used to identify what browser is being used by end user.

Refer

SQL Insert Query Using C#

public static string textDataSource = "Data Source=localhost;Initial 
Catalog=TEST_C;User ID=sa;Password=P@ssw0rd";
public static bool ExtSql(string sql) {
    SqlConnection cnn;
    SqlCommand cmd;
    cnn = new SqlConnection(textDataSource);
    cmd = new SqlCommand(sql, cnn);
    try {
        cnn.Open();
        cmd.ExecuteNonQuery();
        cnn.Close();
        return true;
    }
    catch (Exception) {
        return false;
    }
    finally {
        cmd.Dispose();
        cnn = null;
        cmd = null; 
    }
}

How to initialize static variables

In PHP 7.0.1, I was able to define this:

public static $kIdsByActions = array(
  MyClass1::kAction => 0,
  MyClass2::kAction => 1
);

And then use it like this:

MyClass::$kIdsByActions[$this->mAction];

Getting the docstring from a function

Interactively, you can display it with

help(my_func)

Or from code you can retrieve it with

my_func.__doc__

Java to Jackson JSON serialization: Money fields

I had the same issue and i had it formatted into JSON as a String instead. Might be a bit of a hack but it's easy to implement.

private BigDecimal myValue = new BigDecimal("25.50");
...
public String getMyValue() {
    return myValue.setScale(2, BigDecimal.ROUND_HALF_UP).toString();
}

How to place a div on the right side with absolute position

For top right corner try this:

position: absolute;
top: 0;
right: 0;

Check if a value is in an array (C#)

Note: The question is about arrays of strings. The mentioned routines are not to be mixed with the .Contains method of single strings.

I would like to add an extending answer referring to different C# versions and because of two reasons:

  • The accepted answer requires Linq which is perfectly idiomatic C# while it does not come without costs, and is not available in C# 2.0 or below. When an array is involved, performance may matter, so there are situations where you want to stay with Array methods.

  • No answer directly attends to the question where it was asked also to put this in a function (As some answers are also mixing strings with arrays of strings, this is not completely unimportant).

Array.Exists() is a C#/.NET 2.0 method and needs no Linq. Searching in arrays is O(n). For even faster access use HashSet or similar collections.

Since .NET 3.5 there also exists a generic method Array<T>.Exists() :

public void PrinterSetup(string[] printer)
{
   if (Array.Exists(printer, x => x == "jupiter"))
   {
      Process.Start("BLAH BLAH CODE TO ADD PRINTER VIA WINDOWS EXEC");
   }
}

You could write an own extension method (C# 3.0 and above) to add the syntactic sugar to get the same/similar ".Contains" as for strings for all arrays without including Linq:

// Using the generic extension method below as requested.
public void PrinterSetup(string[] printer)
{
   if (printer.ArrayContains("jupiter"))
   {
      Process.Start("BLAH BLAH CODE TO ADD PRINTER VIA WINDOWS EXEC");
   }
}

public static bool ArrayContains<T>(this T[] thisArray, T searchElement)
{
   // If you want this to find "null" values, you could change the code here
   return Array.Exists<T>(thisArray, x => x.Equals(searchElement));
}

In this case this ArrayContains() method is used and not the Contains method of Linq.

The elsewhere mentioned .Contains methods refer to List<T>.Contains (since C# 2.0) or ArrayList.Contains (since C# 1.1), but not to arrays itself directly.

How do I read the file content from the Internal storage - Android App

I prefer to use java.util.Scanner:

try {
    Scanner scanner = new Scanner(context.openFileInput(filename)).useDelimiter("\\Z");
    StringBuilder sb = new StringBuilder();

    while (scanner.hasNext()) {
        sb.append(scanner.next());
    }

    scanner.close();

    String result = sb.toString();

} catch (IOException e) {}

How to find out which JavaScript events fired?

Just thought I'd add that you can do this in Chrome as well:

Ctrl + Shift + I (Developer Tools) > Sources> Event Listener Breakpoints (on the right).

You can also view all events that have already been attached by simply right clicking on the element and then browsing its properties (the panel on the right).

For example:

  • Right click on the upvote button to the left
  • Select inspect element
  • Collapse the styles section (section on the far right - double chevron)
  • Expand the event listeners option
  • Now you can see the events bound to the upvote
  • Not sure if it's quite as powerful as the firebug option, but has been enough for most of my stuff.

    Another option that is a bit different but surprisingly awesome is Visual Event: http://www.sprymedia.co.uk/article/Visual+Event+2

    It highlights all of the elements on a page that have been bound and has popovers showing the functions that are called. Pretty nifty for a bookmark! There's a Chrome plugin as well if that's more your thing - not sure about other browsers.

    AnonymousAndrew has also pointed out monitorEvents(window); here

    Increment variable value by 1 ( shell programming)

    You can try this :

    i=0
    i=$((i+1))
    

    How to represent matrices in python

    If you are not going to use the NumPy library, you can use the nested list. This is code to implement the dynamic nested list (2-dimensional lists).

    Let r is the number of rows

    let r=3
    
    m=[]
    for i in range(r):
        m.append([int(x) for x in raw_input().split()])
    

    Any time you can append a row using

    m.append([int(x) for x in raw_input().split()])
    

    Above, you have to enter the matrix row-wise. To insert a column:

    for i in m:
        i.append(x) # x is the value to be added in column
    

    To print the matrix:

    print m       # all in single row
    
    for i in m:
        print i   # each row in a different line
    

    Serial Port (RS -232) Connection in C++

    Please take a look here:

    1) You can use this with Windows (incl. MinGW) as well as Linux. Alternative you can only use the code as an example.

    2) Step-by-step tutorial how to use serial ports on windows

    3) You can use this literally on MinGW

    Here's some very, very simple code (without any error handling or settings):

    #include <windows.h>
    
    /* ... */
    
    
    // Open serial port
    HANDLE serialHandle;
    
    serialHandle = CreateFile("\\\\.\\COM1", GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
    
    // Do some basic settings
    DCB serialParams = { 0 };
    serialParams.DCBlength = sizeof(serialParams);
    
    GetCommState(serialHandle, &serialParams);
    serialParams.BaudRate = baudrate;
    serialParams.ByteSize = byteSize;
    serialParams.StopBits = stopBits;
    serialParams.Parity = parity;
    SetCommState(serialHandle, &serialParams);
    
    // Set timeouts
    COMMTIMEOUTS timeout = { 0 };
    timeout.ReadIntervalTimeout = 50;
    timeout.ReadTotalTimeoutConstant = 50;
    timeout.ReadTotalTimeoutMultiplier = 50;
    timeout.WriteTotalTimeoutConstant = 50;
    timeout.WriteTotalTimeoutMultiplier = 10;
    
    SetCommTimeouts(serialHandle, &timeout);
    

    Now you can use WriteFile() / ReadFile() to write / read bytes. Don't forget to close your connection:

    CloseHandle(serialHandle);
    

    Excluding Maven dependencies

    Global exclusions look like they're being worked on, but until then...

    From the Sonatype maven reference (bottom of the page):

    Dependency management in a top-level POM is different from just defining a dependency on a widely shared parent POM. For starters, all dependencies are inherited. If mysql-connector-java were listed as a dependency of the top-level parent project, every single project in the hierarchy would have a reference to this dependency. Instead of adding in unnecessary dependencies, using dependencyManagement allows you to consolidate and centralize the management of dependency versions without adding dependencies which are inherited by all children. In other words, the dependencyManagement element is equivalent to an environment variable which allows you to declare a dependency anywhere below a project without specifying a version number.

    As an example:

      <dependencies>
        <dependency>
          <groupId>commons-httpclient</groupId>
          <artifactId>commons-httpclient</artifactId>
          <version>3.1</version>
        </dependency>
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-beans</artifactId>
          <version>3.0.5.RELEASE</version>
        </dependency>
      </dependencies>
      <dependencyManagement>
        <dependencies>
          <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <exclusions>
              <exclusion>
                <groupId>commons-logging</groupId>
                <artifactId>commons-logging</artifactId>
              </exclusion>
            </exclusions>
          </dependency>
          <dependency>
            <groupId>commons-httpclient</groupId>
            <artifactId>commons-httpclient</artifactId>
            <exclusions>
              <exclusion>
                <groupId>commons-logging</groupId>
                <artifactId>commons-logging</artifactId>
              </exclusion>
            </exclusions>
          </dependency>
        </dependencies>
      </dependencyManagement>
    

    It doesn't make the code less verbose overall, but it does make it less verbose where it counts. If you still want it less verbose you can follow these tips also from the Sonatype reference.

    Disable Drag and Drop on HTML elements?

    try this

    $('#id').on('mousedown', function(event){
        event.preventDefault();
    }
    

    What are some great online database modeling tools?

    I like Clay Eclipse plugin. I've only used it with MySQL, but it claims Firebird support.

    jQuery Validation plugin: validate check box

    You can validate group checkbox and radio button without extra js code, see below example.

    Your JS should be look like:

    $("#formid").validate();
    

    You can play with HTML tag and attributes: eg. group checkbox [minlength=2 and maxlength=4]

    <fieldset class="col-md-12">
      <legend>Days</legend>
      <div class="form-row">
        <div class="col-12 col-md-12 form-group">
            <label class="checkbox-inline">
              <input type="checkbox" name="daysgroup[]" value="1" required="required" data-msg-required="This value is required." minlength="2" maxlength="4" data-msg-maxlength="Max should be 4">Monday
            </label>
            <label class="checkbox-inline">
              <input type="checkbox" name="daysgroup[]" value="2">Tuesday
            </label>
            <label class="checkbox-inline">
              <input type="checkbox" name="daysgroup[]" value="3">Wednesday
            </label>
            <label class="checkbox-inline">
              <input type="checkbox" name="daysgroup[]" value="4">Thursday
            </label>
            <label class="checkbox-inline">
              <input type="checkbox" name="daysgroup[]" value="5">Friday
            </label>
            <label class="checkbox-inline">
              <input type="checkbox" name="daysgroup[]" value="6">Saturday
            </label>
            <label class="checkbox-inline">
              <input type="checkbox" name="daysgroup[]" value="7">Sunday
            </label>
            <label for="daysgroup[]" class="error">Your error message will be display here.</label>
        </div>
      </div>
    </fieldset>
    

    You can see here first or any one input should have required, minlength="2" and maxlength="4" attributes. minlength/maxlength as per your requirement.

    eg. group radio button:

    <fieldset class="col-md-12">
      <legend>Gender</legend>
      <div class="form-row">
        <div class="col-12 col-md-12 form-group">
            <label class="form-check-inline">
              <input type="radio" name="gendergroup[]" value="m" required="required" data-msg-required="This value is required.">man
            </label>
            <label class="form-check-inline">
              <input type="radio" name="gendergroup[]" value="w">woman
            </label>
            <label class="form-check-inline">
              <input type="radio" name="gendergroup[]" value="o">other
            </label>
            <label for="gendergroup[]" class="error">Your error message will be display here.</label>
        </div>
      </div>
    </fieldset>
    

    You can check working example here.

    • jQuery v3.3.x
    • jQuery Validation Plugin - v1.17.0

    How should you diagnose the error SEHException - External component has thrown an exception

    I had a similar problem with an SEHException that was thrown when my program first used a native dll wrapper. Turned out that the native DLL for that wrapper was missing. The exception was in no way helpful in solving this. What did help in the end was running procmon in the background and checking if there were any errors when loading all the necessary DLLs.

    When should I really use noexcept?

    This actually does make a (potentially) huge difference to the optimizer in the compiler. Compilers have actually had this feature for years via the empty throw() statement after a function definition, as well as propriety extensions. I can assure you that modern compilers do take advantage of this knowledge to generate better code.

    Almost every optimization in the compiler uses something called a "flow graph" of a function to reason about what is legal. A flow graph consists of what are generally called "blocks" of the function (areas of code that have a single entrance and a single exit) and edges between the blocks to indicate where flow can jump to. Noexcept alters the flow graph.

    You asked for a specific example. Consider this code:

    void foo(int x) {
        try {
            bar();
            x = 5;
            // Other stuff which doesn't modify x, but might throw
        } catch(...) {
            // Don't modify x
        }
    
        baz(x); // Or other statement using x
    }
    

    The flow graph for this function is different if bar is labeled noexcept (there is no way for execution to jump between the end of bar and the catch statement). When labeled as noexcept, the compiler is certain the value of x is 5 during the baz function - the x=5 block is said to "dominate" the baz(x) block without the edge from bar() to the catch statement.

    It can then do something called "constant propagation" to generate more efficient code. Here if baz is inlined, the statements using x might also contain constants and then what used to be a runtime evaluation can be turned into a compile-time evaluation, etc.

    Anyway, the short answer: noexcept lets the compiler generate a tighter flow graph, and the flow graph is used to reason about all sorts of common compiler optimizations. To a compiler, user annotations of this nature are awesome. The compiler will try to figure this stuff out, but it usually can't (the function in question might be in another object file not visible to the compiler or transitively use some function which is not visible), or when it does, there is some trivial exception which might be thrown that you're not even aware of, so it can't implicitly label it as noexcept (allocating memory might throw bad_alloc, for example).

    Importing CSV File to Google Maps

    GPS Visualizer has an interface by which you can cut and paste a CSV file and convert it to kml:

    http://www.gpsvisualizer.com/map_input?form=googleearth

    Then use Google Earth. If you don't have Google Earth and want to display it online I found another nifty service that will plot kml files online:

    http://display-kml.appspot.com/

    How can I manually generate a .pyc file from a .py file

    You can compile individual files(s) from the command line with:

    python -m compileall <file_1>.py <file_n>.py
    

    Most efficient solution for reading CLOB to String, and String to CLOB in Java?

    My answer is just a flavor of the same. But I tested it with serializing a zipped content and it worked. So I can trust this solution unlike the one offered first (that use readLine) because it will ignore line breaks and corrupt the input.

    /*********************************************************************************************
     * From CLOB to String
     * @return string representation of clob
     *********************************************************************************************/
    private String clobToString(java.sql.Clob data)
    {
        final StringBuilder sb = new StringBuilder();
    
        try
        {
            final Reader         reader = data.getCharacterStream();
            final BufferedReader br     = new BufferedReader(reader);
    
            int b;
            while(-1 != (b = br.read()))
            {
                sb.append((char)b);
            }
    
            br.close();
        }
        catch (SQLException e)
        {
            log.error("SQL. Could not convert CLOB to string",e);
            return e.toString();
        }
        catch (IOException e)
        {
            log.error("IO. Could not convert CLOB to string",e);
            return e.toString();
        }
    
        return sb.toString();
    }
    

    Xcode couldn't find any provisioning profiles matching

    You can get this issue if Apple update their terms. Simply log into your dev account and accept any updated terms and you should be good (you will need to goto Xcode -> project->signing and capabilities and retry the certificate check. This should get you going if terms are the issue.

    How to state in requirements.txt a direct github source

    Normally your requirements.txt file would look something like this:

    package-one==1.9.4
    package-two==3.7.1
    package-three==1.0.1
    ...
    

    To specify a Github repo, you do not need the package-name== convention.

    The examples below update package-two using a GitHub repo. The text between @ and # denotes the specifics of the package.

    Specify commit hash (41b95ec in the context of updated requirements.txt):

    package-one==1.9.4
    git+git://github.com/path/to/package-two@41b95ec#egg=package-two
    package-three==1.0.1
    

    Specify branch name (master):

    git+git://github.com/path/to/package-two@master#egg=package-two
    

    Specify tag (0.1):

    git+git://github.com/path/to/[email protected]#egg=package-two
    

    Specify release (3.7.1):

    git+git://github.com/path/to/package-two@releases/tag/v3.7.1#egg=package-two
    

    Note that #egg=package-two is not a comment here, it is to explicitly state the package name

    This blog post has some more discussion on the topic.

    How should I throw a divide by zero exception in Java without actually dividing by zero?

    There are two ways you could do this. Either create your own custom exception class to represent a divide by zero error or throw the same type of exception the java runtime would throw in this situation.

    Define custom exception

    public class DivideByZeroException() extends ArithmeticException {
    }
    

    Then in your code you would check for a divide by zero and throw this exception:

    if (divisor == 0) throw new DivideByZeroException();
    

    Throw ArithmeticException

    Add to your code the check for a divide by zero and throw an arithmetic exception:

    if (divisor == 0) throw new java.lang.ArithmeticException("/ by zero");
    

    Additionally, you could consider throwing an illegal argument exception since a divisor of zero is an incorrect argument to pass to your setKp() method:

    if (divisor == 0) throw new java.lang.IllegalArgumentException("divisor == 0");
    

    python: create list of tuples from lists

    You're after the zip function.

    Taken directly from the question: How to merge lists into a list of tuples in Python?

    >>> list_a = [1, 2, 3, 4]
    >>> list_b = [5, 6, 7, 8]
    >>> zip(list_a,list_b)
    [(1, 5), (2, 6), (3, 7), (4, 8)]
    

    SQL Server PRINT SELECT (Print a select query result)?

    I wrote this SP to do just what you want, however, you need to use dynamic sql.

    This worked for me on SQL Server 2008 R2

    ALTER procedure [dbo].[PrintSQLResults] 
        @query nvarchar(MAX),
        @numberToDisplay int = 10,
        @padding int = 20
    as
    
    SET NOCOUNT ON;
    SET ANSI_WARNINGS ON;
    
    declare @cols nvarchar(MAX), 
            @displayCols nvarchar(MAX), 
            @sql nvarchar(MAX), 
            @printableResults nvarchar(MAX),
            @NewLineChar AS char(2) = char(13) + char(10),
            @Tab AS char(9) = char(9);
    
    if exists (select * from tempdb.sys.tables where name = '##PrintSQLResultsTempTable') drop table ##PrintSQLResultsTempTable
    
    set @query = REPLACE(@query, 'from', ' into ##PrintSQLResultsTempTable from');
    --print @query
    exec(@query);
    select ROW_NUMBER() OVER (ORDER BY (select Null)) AS ID12345XYZ, * into #PrintSQLResultsTempTable 
    from ##PrintSQLResultsTempTable
    drop table ##PrintSQLResultsTempTable
    
    select name
    into #PrintSQLResultsTempTableColumns
    from tempdb.sys.columns where object_id =
    object_id('tempdb..#PrintSQLResultsTempTable');
    
    select @cols =
    stuff((
        (select ' + space(1) + (LEFT( (CAST([' + name + '] as nvarchar(max)) + space('+ CAST(@padding as nvarchar(4)) +')), '+CAST(@padding as nvarchar(4))+')) ' as [text()]
        FROM #PrintSQLResultsTempTableColumns
        where name != 'ID12345XYZ'
        FOR XML PATH(''), root('str'), type ).value('/str[1]','nvarchar(max)'))
    ,1,0,'''''');
    
    select @displayCols =
    stuff((
        (select space(1) + LEFT(name + space(@padding), @padding) as [text()]
        FROM #PrintSQLResultsTempTableColumns
        where name != 'ID12345XYZ'
        FOR XML PATH(''), root('str'), type ).value('/str[1]','nvarchar(max)'))
    ,1,0,'');
    
    DECLARE 
        @tableCount int = (select count(*) from #PrintSQLResultsTempTable);
    DECLARE 
        @i int = 1, 
        @ii int = case when @tableCount < @numberToDisplay then @tableCount else @numberToDisplay end;
    
    print @displayCols -- header
    While @i <= @ii
    BEGIN
        set @sql = N'select @printableResults = ' + @cols + ' + @NewLineChar from #PrintSQLResultsTempTable where ID12345XYZ = ' + CAST(@i as varchar(3)) + '; print @printableResults;'
        --print @sql
        execute sp_executesql @sql, N'@NewLineChar char(2), @printableResults nvarchar(max) output', @NewLineChar = @NewLineChar, @printableResults = @printableResults output
        print @printableResults
        SET @i += 1;
    END
    

    This worked for me on SQL Server 2012

    ALTER procedure [dbo].[PrintSQLResults] 
        @query nvarchar(MAX),
        @numberToDisplay int = 10,
        @padding int = 20
    as
    
    SET NOCOUNT ON;
    SET ANSI_WARNINGS ON;
    
    declare @cols nvarchar(MAX), 
            @displayCols nvarchar(MAX), 
            @sql nvarchar(MAX), 
            @printableResults nvarchar(MAX),
            @NewLineChar AS char(2) = char(13) + char(10),
            @Tab AS char(9) = char(9);
    
    if exists (select * from tempdb.sys.tables where name = '##PrintSQLResultsTempTable') drop table ##PrintSQLResultsTempTable
    
    set @query = REPLACE(@query, 'from', ' into ##PrintSQLResultsTempTable from');
    --print @query
    exec(@query);
    select ROW_NUMBER() OVER (ORDER BY (select Null)) AS ID12345XYZ, * into #PrintSQLResultsTempTable 
    from ##PrintSQLResultsTempTable
    drop table ##PrintSQLResultsTempTable
    
    select name
    into #PrintSQLResultsTempTableColumns
    from tempdb.sys.columns where object_id =
    object_id('tempdb..#PrintSQLResultsTempTable');
    
    select @cols =
    stuff((
        (select ' + space(1) + LEFT(CAST([' + name + '] as nvarchar('+CAST(@padding as nvarchar(4))+')) + space('+ CAST(@padding as nvarchar(4)) +'), '+CAST(@padding as nvarchar(4))+') ' as [text()]
        FROM #PrintSQLResultsTempTableColumns
        where name != 'ID12345XYZ'
        FOR XML PATH(''), root('str'), type ).value('/str[1]','nvarchar(max)'))
    ,1,0,'''''');
    
    select @displayCols =
    stuff((
        (select space(1) + LEFT(name + space(@padding), @padding) as [text()]
        FROM #PrintSQLResultsTempTableColumns
        where name != 'ID12345XYZ'
        FOR XML PATH(''), root('str'), type ).value('/str[1]','nvarchar(max)'))
    ,1,0,'');
    
    DECLARE 
        @tableCount int = (select count(*) from #PrintSQLResultsTempTable);
    DECLARE 
        @i int = 1, 
        @ii int = case when @tableCount < @numberToDisplay then @tableCount else @numberToDisplay end;
    
    print @displayCols -- header
    While @i <= @ii
    BEGIN
        set @sql = N'select @printableResults = ' + @cols + ' + @NewLineChar   from #PrintSQLResultsTempTable where ID12345XYZ = ' + CAST(@i as varchar(3)) + ' '
        --print @sql
        execute sp_executesql @sql, N'@NewLineChar char(2), @printableResults nvarchar(max) output', @NewLineChar = @NewLineChar, @printableResults = @printableResults output
        print @printableResults
        SET @i += 1;
    END
    

    This worked for me on SQL Server 2014

    ALTER procedure [dbo].[PrintSQLResults] 
        @query nvarchar(MAX),
        @numberToDisplay int = 10,
        @padding int = 20
    as
    
    SET NOCOUNT ON;
    SET ANSI_WARNINGS ON;
    
    declare @cols nvarchar(MAX), 
            @displayCols nvarchar(MAX), 
            @sql nvarchar(MAX), 
            @printableResults nvarchar(MAX),
            @NewLineChar AS char(2) = char(13) + char(10),
            @Tab AS char(9) = char(9);
    
    if exists (select * from tempdb.sys.tables where name = '##PrintSQLResultsTempTable') drop table ##PrintSQLResultsTempTable
    
    set @query = REPLACE(@query, 'from', ' into ##PrintSQLResultsTempTable from');
    --print @query
    exec(@query);
    select ROW_NUMBER() OVER (ORDER BY (select Null)) AS ID12345XYZ, * into #PrintSQLResultsTempTable 
    from ##PrintSQLResultsTempTable
    drop table ##PrintSQLResultsTempTable
    
    select name
    into #PrintSQLResultsTempTableColumns
    from tempdb.sys.columns where object_id =
    object_id('tempdb..#PrintSQLResultsTempTable');
    
    select @cols =
    stuff((
        (select ' , space(1) + LEFT(CAST([' + name + '] as nvarchar('+CAST(@padding as nvarchar(4))+')) + space('+ CAST(@padding as nvarchar(4)) +'), '+CAST(@padding as nvarchar(4))+') ' as [text()]
        FROM #PrintSQLResultsTempTableColumns
        where name != 'ID12345XYZ'
        FOR XML PATH(''), root('str'), type ).value('/str[1]','nvarchar(max)'))
    ,1,0,'''''');
    
    select @displayCols =
    stuff((
        (select space(1) + LEFT(name + space(@padding), @padding) as [text()]
        FROM #PrintSQLResultsTempTableColumns
        where name != 'ID12345XYZ'
        FOR XML PATH(''), root('str'), type ).value('/str[1]','nvarchar(max)'))
    ,1,0,'');
    
    DECLARE 
        @tableCount int = (select count(*) from #PrintSQLResultsTempTable);
    DECLARE 
        @i int = 1, 
        @ii int = case when @tableCount < @numberToDisplay then @tableCount else @numberToDisplay end;
    
    print @displayCols -- header
    While @i <= @ii
    BEGIN
        set @sql = N'select @printableResults = concat(@printableResults, ' + @cols + ', @NewLineChar) from #PrintSQLResultsTempTable where ID12345XYZ = ' + CAST(@i as varchar(3))
        --print @sql
        execute sp_executesql @sql, N'@NewLineChar char(2), @printableResults nvarchar(max) output', @NewLineChar = @NewLineChar, @printableResults = @printableResults output
        print @printableResults
        SET @printableResults = null;
        SET @i += 1;
    END
    

    Example:

    exec [dbo].[PrintSQLResults] n'select * from MyTable'
    

    LDAP: error code 49 - 80090308: LdapErr: DSID-0C0903A9, comment: AcceptSecurityContext error, data 52e, v1db1

    For me issue is resolved by changing envs like this:

     env.put("LDAP_BASEDN", base)
     env.put(Context.SECURITY_PRINCIPAL,"user@domain")
    

    How to send HTML-formatted email?

    This works for me

    msg.BodyFormat = MailFormat.Html;
    

    and then you can use html in your body

    msg.Body = "<em>It's great to use HTML in mail!!</em>"
    

    How to send a POST request using volley with string body?

    I created a function for a Volley Request. You just need to pass the arguments :

    public void callvolly(final String username, final String password){
        RequestQueue MyRequestQueue = Volley.newRequestQueue(this);
        String url = "http://your_url.com/abc.php"; // <----enter your post url here
        StringRequest MyStringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                //This code is executed if the server responds, whether or not the response contains data.
                //The String 'response' contains the server's response.
            }
        }, new Response.ErrorListener() { //Create an error listener to handle errors appropriately.
            @Override
            public void onErrorResponse(VolleyError error) {
                //This code is executed if there is an error.
            }
        }) {
            protected Map<String, String> getParams() {
                Map<String, String> MyData = new HashMap<String, String>();
                MyData.put("username", username);             
                MyData.put("password", password);                
                return MyData;
            }
        };
    
    
        MyRequestQueue.add(MyStringRequest);
    }
    

    jQuery - disable selected options

    pls try this,

    $('#select_id option[value="'+value+'"]').attr("disabled", true);
    

    Using %f with strftime() in Python to get microseconds

    This should do the work

    import datetime
    datetime.datetime.now().strftime("%H:%M:%S.%f")
    

    It will print

    HH:MM:SS.microseconds like this e.g 14:38:19.425961

    Formatting floats in a numpy array

    You can use round function. Here some example

    numpy.round([2.15295647e+01, 8.12531501e+00, 3.97113829e+00, 1.00777250e+01],2)
    array([ 21.53,   8.13,   3.97,  10.08])
    

    IF you want change just display representation, I would not recommended to alter printing format globally, as it suggested above. I would format my output in place.

    >>a=np.array([2.15295647e+01, 8.12531501e+00, 3.97113829e+00, 1.00777250e+01])
    >>> print([ "{:0.2f}".format(x) for x in a ])
    ['21.53', '8.13', '3.97', '10.08']
    

    Use CSS to remove the space between images

    I prefer do like this

    img { float: left; }
    

    to remove the space between images

    how to check for null with a ng-if values in a view with angularjs?

    You can also use ng-template, I think that would be more efficient while run time :)

    <div ng-if="!test.view; else somethingElse">1</div>
    <ng-template #somethingElse>
        <div>2</div>
    </ng-template>
    

    Cheers

    How can I pass selected row to commandLink inside dataTable or ui:repeat?

    As to the cause, the <f:attribute> is specific to the component itself (populated during view build time), not to the iterated row (populated during view render time).

    There are several ways to achieve the requirement.

    1. If your servletcontainer supports a minimum of Servlet 3.0 / EL 2.2, then just pass it as an argument of action/listener method of UICommand component or AjaxBehavior tag. E.g.

       <h:commandLink action="#{bean.insert(item.id)}" value="insert" />
      

      In combination with:

       public void insert(Long id) {
           // ...
       }
      

      This only requires that the datamodel is preserved for the form submit request. Best is to put the bean in the view scope by @ViewScoped.

      You can even pass the entire item object:

       <h:commandLink action="#{bean.insert(item)}" value="insert" />
      

      with:

       public void insert(Item item) {
           // ...
       }
      

      On Servlet 2.5 containers, this is also possible if you supply an EL implementation which supports this, like as JBoss EL. For configuration detail, see this answer.


    2. Use <f:param> in UICommand component. It adds a request parameter.

       <h:commandLink action="#{bean.insert}" value="insert">
           <f:param name="id" value="#{item.id}" />
       </h:commandLink>
      

      If your bean is request scoped, let JSF set it by @ManagedProperty

       @ManagedProperty(value="#{param.id}")
       private Long id; // +setter
      

      Or if your bean has a broader scope or if you want more fine grained validation/conversion, use <f:viewParam> on the target view, see also f:viewParam vs @ManagedProperty:

       <f:viewParam name="id" value="#{bean.id}" required="true" />
      

      Either way, this has the advantage that the datamodel doesn't necessarily need to be preserved for the form submit (for the case that your bean is request scoped).


    3. Use <f:setPropertyActionListener> in UICommand component. The advantage is that this removes the need for accessing the request parameter map when the bean has a broader scope than the request scope.

       <h:commandLink action="#{bean.insert}" value="insert">
           <f:setPropertyActionListener target="#{bean.id}" value="#{item.id}" />
       </h:commandLink>
      

      In combination with

       private Long id; // +setter
      

      It'll be just available by property id in action method. This only requires that the datamodel is preserved for the form submit request. Best is to put the bean in the view scope by @ViewScoped.


    4. Bind the datatable value to DataModel<E> instead which in turn wraps the items.

       <h:dataTable value="#{bean.model}" var="item">
      

      with

       private transient DataModel<Item> model;
      
       public DataModel<Item> getModel() {
           if (model == null) {
               model = new ListDataModel<Item>(items);
           }
           return model;
       }
      

      (making it transient and lazily instantiating it in the getter is mandatory when you're using this on a view or session scoped bean since DataModel doesn't implement Serializable)

      Then you'll be able to access the current row by DataModel#getRowData() without passing anything around (JSF determines the row based on the request parameter name of the clicked command link/button).

       public void insert() {
           Item item = model.getRowData();
           Long id = item.getId();
           // ...
       }
      

      This also requires that the datamodel is preserved for the form submit request. Best is to put the bean in the view scope by @ViewScoped.


    5. Use Application#evaluateExpressionGet() to programmatically evaluate the current #{item}.

       public void insert() {
           FacesContext context = FacesContext.getCurrentInstance();
           Item item = context.getApplication().evaluateExpressionGet(context, "#{item}", Item.class);
           Long id = item.getId();
           // ...
       }
      

    Which way to choose depends on the functional requirements and whether the one or the other offers more advantages for other purposes. I personally would go ahead with #1 or, when you'd like to support servlet 2.5 containers as well, with #2.

    Transfer data between iOS and Android via Bluetooth?

    This question has been asked many times on this site and the definitive answer is: NO, you can't connect an Android phone to an iPhone over Bluetooth, and YES Apple has restrictions that prevent this.

    Some possible alternatives:

    1. Bonjour over WiFi, as you mentioned. However, I couldn't find a comprehensive tutorial for it.
    2. Some internet based sync service, like Dropbox, Google Drive, Amazon S3. These usually have libraries for several platforms.
    3. Direct TCP/IP communication over sockets. (How to write a small (socket) server in iOS)
    4. Bluetooth Low Energy will be possible once the issues on the Android side are solved (Communicating between iOS and Android with Bluetooth LE)

    Coolest alternative: use the Bump API. It has iOS and Android support and really easy to integrate. For small payloads this can be the most convenient solution.

    Details on why you can't connect an arbitrary device to the iPhone. iOS allows only some bluetooth profiles to be used without the Made For iPhone (MFi) certification (HPF, A2DP, MAP...). The Serial Port Profile that you would require to implement the communication is bound to MFi membership. Membership to this program provides you to the MFi authentication module that has to be added to your hardware and takes care of authenticating the device towards the iPhone. Android phones don't have this module, so even though the physical connection may be possible to build up, the authentication step will fail. iPhone to iPhone communication is possible as both ends are able to authenticate themselves.

    How to use jQuery with Angular?

    Here is what worked for me - Angular 2 with webpack

    I tried declaring $ as type any but whenever I tried to use any JQuery module I was getting (for example) $(..).datepicker() is not a function

    Since I have Jquery included in my vendor.ts file I simply imported it into my component using

    import * as $ from 'jquery';

    I am able to use Jquery plugins (like bootstrap-datetimepicker) now

    How to find a value in an excel column by vba code Cells.Find

    Just use

    Dim Cell As Range
    Columns("B:B").Select
    Set cell = Selection.Find(What:="celda", After:=ActiveCell, LookIn:=xlFormulas, _
            LookAt:=xlWhole, SearchOrder:=xlByRows, SearchDirection:=xlNext, _
            MatchCase:=False, SearchFormat:=False)
    
    If cell Is Nothing Then
        'do it something
    
    Else
        'do it another thing
    End If
    

    Re-enabling window.alert in Chrome

    Close and re-open the tab. That should do the trick.

    Django TemplateDoesNotExist?

    Hi guys I found a new solution. Actually it is defined in another template so instead of defining TEMPLATE_DIRS yourself, put your directory path name at their: enter image description here

    How to read user input into a variable in Bash?

    Yep, you'll want to do something like this:

    echo -n "Enter Fullname: " 
    read fullname
    

    Another option would be to have them supply this information on the command line. Getopts is your best bet there.

    Using getopts in bash shell script to get long and short command line options

    Run JavaScript code on window close or page refresh?

    Trying this in React, if the function does not gets executed try wrapping it in an IIFE like this:

    
      window.onbeforeunload = (function () {
        alert('GrrrR!!!')
        return null;
      })()
    
    

    Android Canvas: drawing too large bitmap

    Move your image in the (hi-res) drawable to drawable-xxhdpi. But in app development, you do not need to use large image. It will increase your APK file size.

    Converting between datetime, Timestamp and datetime64

    If you want to convert an entire pandas series of datetimes to regular python datetimes, you can also use .to_pydatetime().

    pd.date_range('20110101','20110102',freq='H').to_pydatetime()
    
    > [datetime.datetime(2011, 1, 1, 0, 0) datetime.datetime(2011, 1, 1, 1, 0)
       datetime.datetime(2011, 1, 1, 2, 0) datetime.datetime(2011, 1, 1, 3, 0)
       ....
    

    It also supports timezones:

    pd.date_range('20110101','20110102',freq='H').tz_localize('UTC').tz_convert('Australia/Sydney').to_pydatetime()
    
    [ datetime.datetime(2011, 1, 1, 11, 0, tzinfo=<DstTzInfo 'Australia/Sydney' EST+11:00:00 DST>)
     datetime.datetime(2011, 1, 1, 12, 0, tzinfo=<DstTzInfo 'Australia/Sydney' EST+11:00:00 DST>)
    ....
    

    NOTE: If you are operating on a Pandas Series you cannot call to_pydatetime() on the entire series. You will need to call .to_pydatetime() on each individual datetime64 using a list comprehension or something similar:

    datetimes = [val.to_pydatetime() for val in df.problem_datetime_column]
    

    Relative path to absolute path in C#?

    You can use Path.Combine with the "base" path, then GetFullPath on the results.

    string absPathContainingHrefs = GetAbsolutePath(); // Get the "base" path
    string fullPath = Path.Combine(absPathContainingHrefs, @"..\..\images\image.jpg");
    fullPath = Path.GetFullPath(fullPath);  // Will turn the above into a proper abs path
    

    Passing Objects By Reference or Value in C#

    One more code sample to showcase this:

    void Main()
    {
    
    
        int k = 0;
        TestPlain(k);
        Console.WriteLine("TestPlain:" + k);
    
        TestRef(ref k);
        Console.WriteLine("TestRef:" + k);
    
        string t = "test";
    
        TestObjPlain(t);
        Console.WriteLine("TestObjPlain:" +t);
    
        TestObjRef(ref t);
        Console.WriteLine("TestObjRef:" + t);
    }
    
    public static void TestPlain(int i)
    {
        i = 5;
    }
    
    public static void TestRef(ref int i)
    {
        i = 5;
    }
    
    public static void TestObjPlain(string s)
    {
        s = "TestObjPlain";
    }
    
    public static void TestObjRef(ref string s)
    {
        s = "TestObjRef";
    }
    

    And the output:

    TestPlain:0

    TestRef:5

    TestObjPlain:test

    TestObjRef:TestObjRef

    Why are there no ++ and --? operators in Python?

    I always assumed it had to do with this line of the zen of python:

    There should be one — and preferably only one — obvious way to do it.

    x++ and x+=1 do the exact same thing, so there is no reason to have both.

    Calling a phone number in swift

    openURL() has been deprecated in iOS 10. Here is the new syntax:

    if let url = URL(string: "tel://\(busPhone)") {
        UIApplication.shared.open(url, options: [:], completionHandler: nil)
    }
    

    HTML5 event handling(onfocus and onfocusout) using angular 2

    I've created a little directive that bind with the tabindex attribute. It adds/removes the has-focus class dynamically.

    @Directive({
        selector: "[tabindex]"
    })
    export class TabindexDirective {
        constructor(private elementHost: ElementRef) {}
    
        @HostListener("focus")
        setInputFocus(): void {
            this.elementHost.nativeElement.classList.add("has-focus");
        }
    
        @HostListener("blur")
        setInputFocusOut(): void {
            this.elementHost.nativeElement.classList.remove("has-focus");
        }
    }
    

    How to change the height of a div dynamically based on another div using css?

    #container-of-boxes {
        display: table;
        width: 1158px;
    }
    #box-1 {
        width: 578px;
    }
    #box-2 {
        width: 386px;
    }
    #box-3 {
        width: 194px;
    }
    #box-1, #box-2, #box-3 {
        min-height: 210px;
        padding-bottom: 20px;
        display: table-cell;
        height: auto;
        overflow: hidden;
    }
    
    • The container must have display:table
    • The boxes inside container must be: display:table-cell
    • Don't put floats.

    Comma separated results in SQL

    this works in sql server 2016

    USE AdventureWorks
    GO
    DECLARE @listStr VARCHAR(MAX)
    SELECT @listStr = COALESCE(@listStr+',' ,'') + Name
    FROM Production.Product
    SELECT @listStr
    GO
    

    Export MySQL database using PHP only

    If you dont have phpMyAdmin, you can write in php CLI commands such as login to mysql and perform db dump. In this case you would use shell_exec function.

    Changes in import statement python3

    Relative import happens whenever you are importing a package relative to the current script/package.

    Consider the following tree for example:

    mypkg
    +-- base.py
    +-- derived.py
    

    Now, your derived.py requires something from base.py. In Python 2, you could do it like this (in derived.py):

    from base import BaseThing
    

    Python 3 no longer supports that since it's not explicit whether you want the 'relative' or 'absolute' base. In other words, if there was a Python package named base installed in the system, you'd get the wrong one.

    Instead it requires you to use explicit imports which explicitly specify location of a module on a path-alike basis. Your derived.py would look like:

    from .base import BaseThing
    

    The leading . says 'import base from module directory'; in other words, .base maps to ./base.py.

    Similarly, there is .. prefix which goes up the directory hierarchy like ../ (with ..mod mapping to ../mod.py), and then ... which goes two levels up (../../mod.py) and so on.

    Please however note that the relative paths listed above were relative to directory where current module (derived.py) resides in, not the current working directory.


    @BrenBarn has already explained the star import case. For completeness, I will have to say the same ;).

    For example, you need to use a few math functions but you use them only in a single function. In Python 2 you were permitted to be semi-lazy:

    def sin_degrees(x):
        from math import *
        return sin(degrees(x))
    

    Note that it already triggers a warning in Python 2:

    a.py:1: SyntaxWarning: import * only allowed at module level
      def sin_degrees(x):
    

    In modern Python 2 code you should and in Python 3 you have to do either:

    def sin_degrees(x):
        from math import sin, degrees
        return sin(degrees(x))
    

    or:

    from math import *
    
    def sin_degrees(x):
        return sin(degrees(x))
    

    Split string into tokens and save them in an array

    Why strtok() is a bad idea

    Do not use strtok() in normal code, strtok() uses static variables which have some problems. There are some use cases on embedded microcontrollers where static variables make sense but avoid them in most other cases. strtok() behaves unexpected when more than 1 thread uses it, when it is used in a interrupt or when there are some other circumstances where more than one input is processed between successive calls to strtok(). Consider this example:

    #include <stdio.h>
    #include <string.h>
    
    //Splits the input by the / character and prints the content in between
    //the / character. The input string will be changed
    void printContent(char *input)
    {
        char *p = strtok(input, "/");
        while(p)
        {
            printf("%s, ",p);
            p = strtok(NULL, "/");
        }
    }
    
    int main(void)
    {
        char buffer[] = "abc/def/ghi:ABC/DEF/GHI";
        char *p = strtok(buffer, ":");
        while(p)
        {
            printContent(p);
            puts(""); //print newline
            p = strtok(NULL, ":");
        }
        return 0;
    }
    

    You may expect the output:

    abc, def, ghi,
    ABC, DEF, GHI,
    

    But you will get

    abc, def, ghi,
    

    This is because you call strtok() in printContent() resting the internal state of strtok() generated in main(). After returning, the content of strtok() is empty and the next call to strtok() returns NULL.

    What you should do instead

    You could use strtok_r() when you use a POSIX system, this versions does not need static variables. If your library does not provide strtok_r() you can write your own version of it. This should not be hard and Stackoverflow is not a coding service, you can write it on your own.

    How do I check if a string contains another string in Swift?

    Just an addendum to the answers here.

    You can also do a local case insensitive test using:

     - (BOOL)localizedCaseInsensitiveContainsString:(NSString *)aString
    

    Example:

        import Foundation
    
        var string: NSString  =  "hello Swift"
       if string.localizedCaseInsensitiveContainsString("Hello") {
        println("TRUE")
    }
    

    UPDATE

    This is part of the Foundation Framework for iOS & Mac OS X 10.10.x and was part of 10.10 at Time of my original Posting.

    Document Generated: 2014-06-05 12:26:27 -0700 OS X Release Notes Copyright © 2014 Apple Inc. All Rights Reserved.

    OS X 10.10 Release Notes Cocoa Foundation Framework

    NSString now has the following two convenience methods:

    - (BOOL)containsString:(NSString *)str;

    - (BOOL)localizedCaseInsensitiveContainsString:(NSString *)str;

    How to disable scrolling temporarily?

    I'm using showModalDialog, for showing secondary page as modal dialog.

    to hide main window scrollbars:

    document.body.style.overflow = "hidden";
    

    and when closing modal dialog, showing main window scrollbars:

    document.body.style.overflow = "scroll";
    

    to access elements in main window from dialog:

    parent.document.getElementById('dialog-close').click();
    

    just for anybody searching about showModalDialog:(after line 29 of original code)

    document.getElementById('dialog-body').contentWindow.dialogArguments = arg;
    document.body.style.overflow = "hidden";//****
    document.getElementById('dialog-close').addEventListener('click', function(e) {
        e.preventDefault();
        document.body.style.overflow = "scroll";//****
        dialog.close();
    });
    

    Why there can be only one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT clause?

    I also wondered that long time ago. I searched a bit in my history and I think that this post: http://lists.mysql.com/internals/34919 represents the semi-official position of MySQL (before Oracle's intervention ;))

    In short:

    this limitation stems only from the way in which this feature is currently implemented in the server and there are no other reasons for its existence.

    So their explanation is "because it is implemented like this". Doesn't sound very scientific. I guess it all comes from some old code. This is suggested in the thread above: "carry-over from when only the first timestamp field was auto-set/update".

    Cheers!

    Import-CSV and Foreach

    $IP_Array = (Get-Content test2.csv)[0].split(",")
    foreach ( $IP in $IP_Array){
        $IP
    }
    

    Get-content Filename returns an array of strings for each line.

    On the first string only, I split it based on ",". Dumping it into $IP_Array.

    $IP_Array = (Get-Content test2.csv)[0].split(",")
    foreach ( $IP in $IP_Array){
      if ($IP -eq "2.2.2.2") {
        Write-Host "Found $IP"
      }
    }
    

    Calling Scalar-valued Functions in SQL

    Make sure you have the correct database selected. You may have the master database selected if you are trying to run it in a new query window.

    std::enable_if to conditionally compile a member function

    The boolean needs to depend on the template parameter being deduced. So an easy way to fix is to use a default boolean parameter:

    template< class T >
    class Y {
    
        public:
            template < bool EnableBool = true, typename = typename std::enable_if<( std::is_same<T, double>::value && EnableBool )>::type >
            T foo() {
                return 10;
            }
    
    };
    

    However, this won't work if you want to overload the member function. Instead, its best to use TICK_MEMBER_REQUIRES from the Tick library:

    template< class T >
    class Y {
    
        public:
            TICK_MEMBER_REQUIRES(std::is_same<T, double>::value)
            T foo() {
                return 10;
            }
    
            TICK_MEMBER_REQUIRES(!std::is_same<T, double>::value)
            T foo() {
                return 10;
            }
    
    };
    

    You can also implement your own member requires macro like this(just in case you don't want to use another library):

    template<long N>
    struct requires_enum
    {
        enum class type
        {
            none,
            all       
        };
    };
    
    
    #define MEMBER_REQUIRES(...) \
    typename requires_enum<__LINE__>::type PrivateRequiresEnum ## __LINE__ = requires_enum<__LINE__>::type::none, \
    class=typename std::enable_if<((PrivateRequiresEnum ## __LINE__ == requires_enum<__LINE__>::type::none) && (__VA_ARGS__))>::type
    

    What is a file with extension .a?

    .a files are static libraries typically generated by the archive tool. You usually include the header files associated with that static library and then link to the library when you are compiling.

    Print second last column/field in awk

    First decrements the value and then print it -

    awk ' { print $(--NF)}' file
    

    OR

    rev file|cut -d ' ' -f2|rev
    

    How to comment out a block of code in Python

    The only way you can do this without triple quotes is to add an:

    if False:
    

    And then indent all your code. Note that the code will still need to have proper syntax.


    Many Python IDEs can add # for you on each selected line, and remove them when un-commenting too. Likewise, if you use vi or Emacs you can create a macro to do this for you for a block of code.

    How to export datagridview to excel using vb.net?

    The following code works fine for me :)

    Protected Sub ExportToExcel(sender As Object, e As EventArgs) Handles ExportExcel.Click
            Try
                Response.Clear()
                Response.Buffer = True
                Response.AddHeader("content-disposition", "attachment;filename=ExportEthias.xls")
                Response.Charset = ""
                Response.ContentType = "application/vnd.ms-excel"
                Using sw As New StringWriter()
                    Dim hw As New HtmlTextWriter(sw)
                    GvActifs.RenderControl(hw)
                    'Le format de base est le texte pour éviter les problèmes d'arrondis des nombres
                    Dim style As String = "<style> .textmode { } </style>"
                    Response.Write(Style)
                    Response.Output.Write(sw.ToString())
                    Response.Flush()
                    Response.End()
                End Using
            Catch ex As Exception
                lblMessage.Text = "Erreur export Excel : " & ex.Message
            End Try
        End Sub
        Public Overrides Sub VerifyRenderingInServerForm(control As Control)
            ' Verifies that the control is rendered
        End Sub
    

    Hopes this help you.

    Is it possible in Java to catch two exceptions in the same catch block?

    Java <= 6.x just allows you to catch one exception for each catch block:

    try {
    
    } catch (ExceptionType name) {
    
    } catch (ExceptionType name) {
    
    }
    

    Documentation:

    Each catch block is an exception handler and handles the type of exception indicated by its argument. The argument type, ExceptionType, declares the type of exception that the handler can handle and must be the name of a class that inherits from the Throwable class.

    For Java 7 you can have multiple Exception caught on one catch block:

    catch (IOException|SQLException ex) {
        logger.log(ex);
        throw ex;
    }
    

    Documentation:

    In Java SE 7 and later, a single catch block can handle more than one type of exception. This feature can reduce code duplication and lessen the temptation to catch an overly broad exception.

    Reference: http://docs.oracle.com/javase/tutorial/essential/exceptions/catch.html

    Search input with an icon Bootstrap 4

    you can also do in this way using input-group

    <div class="input-group">
      <input class="form-control"
             placeholder="I can help you to find anything you want!">
      <div class="input-group-addon" ><i class="fa fa-search"></i></div>
    </div>
    

    codeply

    How to pass an event object to a function in Javascript?

    1. Modify the definition of the function check_me as::

       function check_me(ev) {
      
    2. Now you can access the methods and parameters of the event, in your case:

       ev.preventDefault();
      
    3. Then, you have to pass the parameter on the onclick in the inline call::

       <button type="button" onclick="check_me(event);">Click Me!</button>
      

    A useful link to understand this.


    Full example:

    <!DOCTYPE html>
    <html lang="en">
      <head>
        <script type="text/javascript">
          function check_me(ev) {
            ev.preventDefault();
            alert("Hello World!")
          }
        </script>
      </head>
      <body>
        <button type="button" onclick="check_me(event);">Click Me!</button>
      </body>
    </html>
    









    Alternatives (best practices):

    Although the above is the direct answer to the question (passing an event object to an inline event), there are other ways of handling events that keep the logic separated from the presentation

    A. Using addEventListener:

    <!DOCTYPE html>
    <html lang="en">
      <head>
      </head>
      <body>
        <button id='my_button' type="button">Click Me!</button>
    
        <!-- put the javascript at the end to guarantee that the DOM is ready to use-->
        <script type="text/javascript">
          function check_me(ev) {
            ev.preventDefault();
            alert("Hello World!")
          }
          
          <!-- add the event to the button identified #my_button -->
          document.getElementById("my_button").addEventListener("click", check_me);
        </script>
      </body>
    </html>
    

    B. Isolating Javascript:

    Both of the above solutions are fine for a small project, or a hackish quick and dirty solution, but for bigger projects, it is better to keep the HTML separated from the Javascript.

    Just put this two files in the same folder:

    • example.html:
    <!DOCTYPE html>
    <html lang="en">
      <head>
      </head>
      <body>
        <button id='my_button' type="button">Click Me!</button>
    
        <!-- put the javascript at the end to guarantee that the DOM is ready to use-->
        <script type="text/javascript" src="example.js"></script>
      </body>
    </html>
    
    • example.js:
    function check_me(ev) {
        ev.preventDefault();
        alert("Hello World!")
    }
    document.getElementById("my_button").addEventListener("click", check_me);
    

    Using msbuild to execute a File System Publish Profile

    FYI: I had the same issue with Visual Studio 2015. After many of hours trying, I can now do msbuild myproject.csproj /p:DeployOnBuild=true /p:PublishProfile=myprofile.

    I had to edit my .csproj file to get it working. It contained a line like this:

    <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v10.0\WebApplications\Microsoft.WebApplication.targets" 
      Condition="false" />
    

    I changed this line as follows:

    <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v14.0\WebApplications\Microsoft.WebApplication.targets" />
    

    (I changed 10.0 to 14.0, not sure whether this was necessary. But I definitely had to remove the condition part.)

    How to process a file in PowerShell line-by-line as a stream

    If you are really about to work on multi-gigabyte text files then do not use PowerShell. Even if you find a way to read it faster processing of huge amount of lines will be slow in PowerShell anyway and you cannot avoid this. Even simple loops are expensive, say for 10 million iterations (quite real in your case) we have:

    # "empty" loop: takes 10 seconds
    measure-command { for($i=0; $i -lt 10000000; ++$i) {} }
    
    # "simple" job, just output: takes 20 seconds
    measure-command { for($i=0; $i -lt 10000000; ++$i) { $i } }
    
    # "more real job": 107 seconds
    measure-command { for($i=0; $i -lt 10000000; ++$i) { $i.ToString() -match '1' } }
    

    UPDATE: If you are still not scared then try to use the .NET reader:

    $reader = [System.IO.File]::OpenText("my.log")
    try {
        for() {
            $line = $reader.ReadLine()
            if ($line -eq $null) { break }
            # process the line
            $line
        }
    }
    finally {
        $reader.Close()
    }
    

    UPDATE 2

    There are comments about possibly better / shorter code. There is nothing wrong with the original code with for and it is not pseudo-code. But the shorter (shortest?) variant of the reading loop is

    $reader = [System.IO.File]::OpenText("my.log")
    while($null -ne ($line = $reader.ReadLine())) {
        $line
    }
    

    How can I parse a String to BigDecimal?

    BigDecimal offers a string constructor. You'll need to strip all commas from the number, via via an regex or String filteredString=inString.replaceAll(",","").

    You then simply call BigDecimal myBigD=new BigDecimal(filteredString);

    You can also create a NumberFormat and call setParseBigDecimal(true). Then parse( will give you a BigDecimal without worrying about manually formatting.

    Adding image inside table cell in HTML

    You have a TH floating at the top of your table which isn't within a TR. Fix that.

    With regards to your image problem you;re referencing the image absolutely from your computer's hard drive. Don't do that.

    You also have a closing tag which shouldn't be there.

    It should be:

    <img src="h.gif" alt="" border="3" height="100" width="100" />
    

    Also this:

    <table border = 5 bordercolor = red align = center>
    

    Your colspans are also messed up. You only seem to have three columns but have colspans of 14 and 4 in your code.

    Should be:

    <table border="5" bordercolor="red" align="center">
    

    Also you have no DOCTYPE declared. You should at least add:

    <!DOCTYPE html> 
    

    SQL/mysql - Select distinct/UNIQUE but return all columns?

    SELECT DISTINCT FIELD1, FIELD2, FIELD3 FROM TABLE1 works if the values of all three columns are unique in the table.

    If, for example, you have multiple identical values for first name, but the last name and other information in the selected columns is different, the record will be included in the result set.

    How to list active / open connections in Oracle?

    select s.sid as "Sid", s.serial# as "Serial#", nvl(s.username, ' ') as "Username", s.machine as "Machine", s.schemaname as "Schema name", s.logon_time as "Login time", s.program as "Program", s.osuser as "Os user", s.status as "Status", nvl(s.process, ' ') as "OS Process id"
    from v$session s
    where nvl(s.username, 'a') not like 'a' and status like 'ACTIVE'
    order by 1,2
    

    This query attempts to filter out all background processes.

    Can you split/explode a field in a MySQL query?

    There's an easier way, have a link table, i.e.:

    Table 1: clients, client info, blah blah blah

    Table 2: courses, course info, blah blah

    Table 3: clientid, courseid

    Then do a JOIN and you're off to the races.

    Android button background color

    If you don't mind hardcoding it you can do this ~> android:background="#eeeeee" and drop any hex color # you wish.

    Looks like this....

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/textView1"
        android:text="@string/ClickMe"
        android:background="#fff"/>
    

    How to get PID of process I've just started within java program?

    One solution is to use the idiosyncratic tools the platform offers:

    private static String invokeLinuxPsProcess(String filterByCommand) {
        List<String> args = Arrays.asList("ps -e -o stat,pid,unit,args=".split(" +"));
        // Example output:
        // Sl   22245 bpds-api.service                /opt/libreoffice5.4/program/soffice.bin --headless
        // Z    22250 -                               [soffice.bin] <defunct>
    
        try {
            Process psAux = new ProcessBuilder(args).redirectErrorStream(true).start();
            try {
                Thread.sleep(100); // TODO: Find some passive way.
            } catch (InterruptedException e) { }
    
            try (BufferedReader reader = new BufferedReader(new InputStreamReader(psAux.getInputStream(), StandardCharsets.UTF_8))) {
                String line;
                while ((line = reader.readLine()) != null) {
                    if (!line.contains(filterByCommand))
                        continue;
                    String[] parts = line.split("\\w+");
                    if (parts.length < 4)
                        throw new RuntimeException("Unexpected format of the `ps` line, expected at least 4 columns:\n\t" + line);
                    String pid = parts[1];
                    return pid;
                }
            }
        }
        catch (IOException ex) {
            log.warn(String.format("Failed executing %s: %s", args, ex.getMessage()), ex);
        }
        return null;
    }
    

    Disclaimer: Not tested, but you get the idea:

    • Call ps to list the processes,
    • Find your one because you know the command you launched it with.
    • If there are multiple processes with the same command, you can:
      • Add another dummy argument to differentiate them
      • Rely on the increasing PID (not really safe, not concurrent)
      • Check the time of process creation (could be too coarse to really differentiate, also not concurrent)
      • Add a specific environment variable and list it with ps too.

    What is the difference between Sessions and Cookies in PHP?

    A cookie is a bit of data stored by the browser and sent to the server with every request.

    A session is a collection of data stored on the server and associated with a given user (usually via a cookie containing an id code)

    How to Resize image in Swift?

    Here's a general method (in Swift 5) for downscaling an image to fit a size. The resulting image can have the same aspect ratio as the original, or it can be the target size with the original image centered in it. If the image is smaller than the target size, it is not resized.

    extension UIImage {
        func scaledDown(into size:CGSize, centered:Bool = false) -> UIImage {
            var (targetWidth, targetHeight) = (self.size.width, self.size.height)
            var (scaleW, scaleH) = (1 as CGFloat, 1 as CGFloat)
            if targetWidth > size.width {
                scaleW = size.width/targetWidth
            }
            if targetHeight > size.height {
                scaleH = size.height/targetHeight
            }
            let scale = min(scaleW,scaleH)
            targetWidth *= scale; targetHeight *= scale
            let sz = CGSize(width:targetWidth, height:targetHeight)
            if !centered {
                return UIGraphicsImageRenderer(size:sz).image { _ in
                    self.draw(in:CGRect(origin:.zero, size:sz))
                }
            }
            let x = (size.width - targetWidth)/2
            let y = (size.height - targetHeight)/2
            let origin = CGPoint(x:x,y:y)
            return UIGraphicsImageRenderer(size:size).image { _ in
                self.draw(in:CGRect(origin:origin, size:sz))
            }
        }
    }
    

    How to edit a text file in my terminal

    Try this command:

    sudo gedit helloWorld.txt
    

    it, will open up a text editor to edit your file.

    OR

    sudo nano helloWorld.txt
    

    Here, you can edit your file in the terminal window.

    How to open select file dialog via js?

    For the sake of completeness, Ron van der Heijden's solution in pure JavaScript:

    <button onclick="document.querySelector('.inputFile').click();">Select File ...</button>
    <input class="inputFile" type="file" style="display: none;">
    

    Must declare the scalar variable

    Just FYI, I know this is an old post, but depending on the database COLLATION settings you can get this error on a statement like this,

    SET @sql = @Sql + ' WHERE RowNum BETWEEN @RowFrom AND @RowTo;';
    

    if for example you typo the S in the

    SET @sql = @***S***ql 
    

    sorry to spin off the answers already posted here, but this is an actual instance of the error reported.

    Note also that the error will not display the capital S in the message, I am not sure why, but I think it is because the

    Set @sql =
    

    is on the left of the equal sign.

    jQuery event for images loaded

      function CheckImageLoadingState()
      {
         var counter = 0;
         var length = 0;
    
         jQuery('#siteContent img').each(function() 
         {
            if(jQuery(this).attr('src').match(/(gif|png|jpg|jpeg)$/))
              length++;
         });
    
         jQuery('#siteContent img').each(function() 
         {  
            if(jQuery(this).attr('src').match(/(gif|png|jpg|jpeg)$/))
            {
               jQuery(this).load(function() 
               {
               }).each(function() {
                  if(this.complete) jQuery(this).load();
                });
            }
            jQuery(this).load(function()
            {
               counter++;
               if(counter === length) 
               {  
                  //function to call when all the images have been loaded
                  DisplaySiteContent();
               }
            });
         });
      }
    

    how to check confirm password field in form without reloading page

    Using Native setCustomValidity

    Compare the password/confirm-password input values on their change event and setCustomValidity accordingly:

    _x000D_
    _x000D_
    function onChange() {_x000D_
      const password = document.querySelector('input[name=password]');_x000D_
      const confirm = document.querySelector('input[name=confirm]');_x000D_
      if (confirm.value === password.value) {_x000D_
        confirm.setCustomValidity('');_x000D_
      } else {_x000D_
        confirm.setCustomValidity('Passwords do not match');_x000D_
      }_x000D_
    }
    _x000D_
    <form>_x000D_
      <label>Password: <input name="password" type="password" onChange="onChange()" /> </label><br />_x000D_
      <label>Confirm : <input name="confirm"  type="password" onChange="onChange()" /> </label><br />_x000D_
      <input type="submit" />_x000D_
    </form>
    _x000D_
    _x000D_
    _x000D_

    How do I view the SQLite database on an Android device?

    Here are step-by-step instructions (mostly taken from a combination of the other answers). This works even on devices that are not rooted.

    1. Connect your device and launch the application in debug mode.

    2. You may want to use adb -d shell "run-as com.yourpackge.name ls /data/data/com.yourpackge.name/databases/" to see what the database filename is.

    Notice: com.yourpackge.name is your application package name. You can get it from the manifest file.

    1. Copy the database file from your application folder to your SD card.

      adb -d shell "run-as com.yourpackge.name cat /data/data/com.yourpackge.name/databases/filename.sqlite > /sdcard/filename.sqlite"

    Notice: filename.sqlite is your database name you used when you created the database

    1. Pull the database files to your machine:

      adb pull /sdcard/filename.sqlite

    This will copy the database from the SD card to the place where your ADB exist.

    1. Install Firefox SQLite Manager: https://addons.mozilla.org/en-US/firefox/addon/sqlite-manager/

    2. Open Firefox SQLite Manager (Tools->SQLite Manager) and open your database file from step 3 above.

    3. Enjoy!

    Raw SQL Query without DbSet - Entity Framework Core

    My case used stored procedure instead of raw SQL

    Created a class

    Public class School
    {
        [Key]
        public Guid SchoolId { get; set; }
        public string Name { get; set; }
        public string Branch { get; set; }
        public int NumberOfStudents  { get; set; }
    }
    

    Added below on my DbContext class

    public DbSet<School> SP_Schools { get; set; }
    

    To execute the stored procedure:

    var MySchools = _db.SP_Schools.FromSqlRaw("GetSchools @schoolId, @page, @size ",
                  new SqlParameter("schoolId", schoolId),
                  new SqlParameter("page", page),
                  new SqlParameter("size", size)))
    .IgnoreQueryFilters();
    

    Download files from server php

    To read directory contents you can use readdir() and use a script, in my example download.php, to download files

    if ($handle = opendir('/path/to/your/dir/')) {
        while (false !== ($entry = readdir($handle))) {
            if ($entry != "." && $entry != "..") {
                echo "<a href='download.php?file=".$entry."'>".$entry."</a>\n";
            }
        }
        closedir($handle);
    }
    

    In download.php you can force browser to send download data, and use basename() to make sure client does not pass other file name like ../config.php

    $file = basename($_GET['file']);
    $file = '/path/to/your/dir/'.$file;
    
    if(!file_exists($file)){ // file does not exist
        die('file not found');
    } else {
        header("Cache-Control: public");
        header("Content-Description: File Transfer");
        header("Content-Disposition: attachment; filename=$file");
        header("Content-Type: application/zip");
        header("Content-Transfer-Encoding: binary");
    
        // read the file from disk
        readfile($file);
    }
    

    Calling class staticmethod within the class body?

    If the "core problem" is assigning class variables using functions, an alternative is to use a metaclass (it's kind of "annoying" and "magical" and I agree that the static method should be callable inside the class, but unfortunately it isn't). This way, we can refactor the behavior into a standalone function and don't clutter the class.

    class KlassMetaClass(type(object)):
        @staticmethod
        def _stat_func():
            return 42
    
        def __new__(cls, clsname, bases, attrs):
            # Call the __new__ method from the Object metaclass
            super_new = super().__new__(cls, clsname, bases, attrs)
            # Modify class variable "_ANS"
            super_new._ANS = cls._stat_func()
            return super_new
    
    class Klass(object, metaclass=KlassMetaClass):
        """
        Class that will have class variables set pseudo-dynamically by the metaclass
        """
        pass
    
    print(Klass._ANS) # prints 42
    

    Using this alternative "in the real world" may be problematic. I had to use it to override class variables in Django classes, but in other circumstances maybe it's better to go with one of the alternatives from the other answers.

    How to get all columns' names for all the tables in MySQL?

    Similar to the answer posted by @suganya this doesn't directly answer the question but is a quicker alternative for a single table:

    DESCRIBE column_name;
    

    CSS vertical alignment text inside li

    Define the parent with display: table and the element itself with vertical-align: middle and display: table-cell.

    Change the encoding of a file in Visual Studio Code

    The existing answers show a possible solution for single files or file types. However, you can define the charset standard in VS Code by following this path:

    File > Preferences > Settings > Encoding > Choose your option

    This will define a character set as default. Besides that, you can always change the encoding in the lower right corner of the editor (blue symbol line) for the current project.

    Why can't DateTime.ParseExact() parse "9/1/2009" using "M/d/yyyy"

    I bet your machine's culture is not "en-US". From the documentation:

    If provider is a null reference (Nothing in Visual Basic), the current culture is used.

    If your current culture is not "en-US", this would explain why it works for me but doesn't work for you and works when you explicitly specify the culture to be "en-US".

    MySQL - ERROR 1045 - Access denied

    Try connecting without any password:

    mysql -u root
    

    I believe the initial default is no password for the root account (which should obviously be changed as soon as possible).

    C# Creating and using Functions

    Note: in C# the term "function" is often replaced by the term "method". For the sake of this question there is no difference, so I'll just use the term "function".

    The other answers have already given you a quick way to fix your problem (just make Add a static function), but I'd like to explain why.

    C# has a fundamentally different design paradigm than C. That paradigm is called object-oriented programming (OOP). Explaining all the differences between OOP and functional programming is beyond the scope of this question, but here's the short version as it applies to you.

    Writing your program in C, you would have created a function that adds two numbers, and that function would exist independently and be callable from anywhere. In C# most functions don't exist independently; instead, they exist in the context of an object. In your example code, only an instance (an object) of the class Program knows how to perform Add. Said another way, you have to create an instance of Program, and then ask Program to perform an Add for you.

    The solutions that people gave you, using the static keyword, route around that design. Using the static keyword is kind of like saying, "Hey, this function I'm defining doesn't need any context/state, it can just be called." Since your Add function is very simple, this makes sense. As you start diving deeper into OOP, you're going to find that your functions get more complicated and rely on knowing their state/context.

    My advice: Pick up an OOP book and get ready to switch your brain from functional programming to OOP programming. You're in for a ride.

    Load dimension value from res/values/dimension.xml from source code

    Use a Kotlin Extension

    You can add an extension to simplify this process. It enables you to just call context.dp(R.dimen. tutorial_cross_marginTop) to get the Float value

    fun Context.px(@DimenRes dimen: Int): Int = resources.getDimension(dimen).toInt()
    
    fun Context.dp(@DimenRes dimen: Int): Float = px(dimen) / resources.displayMetrics.density
    

    If you want to handle it without context, you can use Resources.getSystem():

    val Int.dp get() = this / Resources.getSystem().displayMetrics.density // Float
    
    val Int.px get() = (this * Resources.getSystem().displayMetrics.density).toInt()
    

    For example, on an xhdpi device, use 24.dp to get 12.0 or 12.px to get 24

    How to hide the Google Invisible reCAPTCHA badge

    Set the data-badge attribute to inline

    <button type="submit" data-sitekey="your_site_key" data-callback="onSubmit" data-badge="inline" />
    

    And add the following CSS

    .grecaptcha-badge {
        display: none;
    }
    

    pandas dataframe columns scaling with sklearn

    As it is being mentioned in pir's comment - the .apply(lambda el: scale.fit_transform(el)) method will produce the following warning:

    DeprecationWarning: Passing 1d arrays as data is deprecated in 0.17 and will raise ValueError in 0.19. Reshape your data either using X.reshape(-1, 1) if your data has a single feature or X.reshape(1, -1) if it contains a single sample.

    Converting your columns to numpy arrays should do the job (I prefer StandardScaler):

    from sklearn.preprocessing import StandardScaler
    scale = StandardScaler()
    
    dfTest[['A','B','C']] = scale.fit_transform(dfTest[['A','B','C']].as_matrix())
    

    -- Edit Nov 2018 (Tested for pandas 0.23.4)--

    As Rob Murray mentions in the comments, in the current (v0.23.4) version of pandas .as_matrix() returns FutureWarning. Therefore, it should be replaced by .values:

    from sklearn.preprocessing import StandardScaler
    scaler = StandardScaler()
    
    scaler.fit_transform(dfTest[['A','B']].values)
    

    -- Edit May 2019 (Tested for pandas 0.24.2)--

    As joelostblom mentions in the comments, "Since 0.24.0, it is recommended to use .to_numpy() instead of .values."

    Updated example:

    import pandas as pd
    from sklearn.preprocessing import StandardScaler
    scaler = StandardScaler()
    dfTest = pd.DataFrame({
                   'A':[14.00,90.20,90.95,96.27,91.21],
                   'B':[103.02,107.26,110.35,114.23,114.68],
                   'C':['big','small','big','small','small']
                 })
    dfTest[['A', 'B']] = scaler.fit_transform(dfTest[['A','B']].to_numpy())
    dfTest
          A         B      C
    0 -1.995290 -1.571117    big
    1  0.436356 -0.603995  small
    2  0.460289  0.100818    big
    3  0.630058  0.985826  small
    4  0.468586  1.088469  small
    

    Is there any native DLL export functions viewer?

    dumpbin from the Visual Studio command prompt:

    dumpbin /exports csp.dll
    

    Example of output:

    Microsoft (R) COFF/PE Dumper Version 10.00.30319.01
    Copyright (C) Microsoft Corporation.  All rights reserved.
    
    
    Dump of file csp.dll
    
    File Type: DLL
    
      Section contains the following exports for CSP.dll
    
        00000000 characteristics
        3B1D0B77 time date stamp Tue Jun 05 12:40:23 2001
            0.00 version
               1 ordinal base
              25 number of functions
              25 number of names
    
        ordinal hint RVA      name
    
              1    0 00001470 CPAcquireContext
              2    1 000014B0 CPCreateHash
              3    2 00001520 CPDecrypt
              4    3 000014B0 CPDeriveKey
              5    4 00001590 CPDestroyHash
              6    5 00001590 CPDestroyKey
              7    6 00001560 CPEncrypt
              8    7 00001520 CPExportKey
              9    8 00001490 CPGenKey
             10    9 000015B0 CPGenRandom
             11    A 000014D0 CPGetHashParam
             12    B 000014D0 CPGetKeyParam
             13    C 00001500 CPGetProvParam
             14    D 000015C0 CPGetUserKey
             15    E 00001580 CPHashData
             16    F 000014F0 CPHashSessionKey
             17   10 00001540 CPImportKey
             18   11 00001590 CPReleaseContext
             19   12 00001580 CPSetHashParam
             20   13 00001580 CPSetKeyParam
             21   14 000014F0 CPSetProvParam
             22   15 00001520 CPSignHash
             23   16 000015A0 CPVerifySignature
             24   17 00001060 DllRegisterServer
             25   18 00001000 DllUnregisterServer
    
      Summary
    
            1000 .data
            1000 .rdata
            1000 .reloc
            1000 .rsrc
            1000 .text
    
    

    How could I create a list in c++?

    Create list using C++ templates

    i.e

    template <class T> struct Node 
    {
        T data;
        Node * next;
    };
        
    template <class T> class List 
    {
        Node<T> *head,*tail;
            
        public: 
            void push(T const&);  // push element 
            void pop();           // pop element 
            bool empty()          // return true if empty. 
    }; 
    

    Then you can write the code like:

    List<MyClass>;
    

    The type T is not dynamic in run time.It is only for the compile time.

    For complete example click here.

    For C++ templates tutorial click here.

    Could not obtain information about Windows NT group user

    I had to connect to VPN for the publish script to successfully deploy to the DB.

    PHP - syntax error, unexpected T_CONSTANT_ENCAPSED_STRING

    You have a sintax error in your code:

    try changing this line

    $out.='<option value=''.$key.'">'.$value["name"].';
    

    with

    $out.='<option value="'.$key.'">'.$value["name"].'</option>';
    

    Foreach with JSONArray and JSONObject

    Apparently, org.json.simple.JSONArray implements a raw Iterator. This means that each element is considered to be an Object. You can try to cast:

    for(Object o: arr){
        if ( o instanceof JSONObject ) {
            parse((JSONObject)o);
        }
    }
    

    This is how things were done back in Java 1.4 and earlier.

    Setting query string using Fetch GET request

    Maybe this is better:

    const withQuery = require('with-query');
    
    fetch(withQuery('https://api.github.com/search/repositories', {
      q: 'query',
      sort: 'stars',
      order: 'asc',
    }))
    .then(res => res.json())
    .then((json) => {
      console.info(json);
    })
    .catch((err) => {
      console.error(err);
    });
    

    My Application Could not open ServletContext resource

    Quote from the Spring reference doc:

    Upon initialization of a DispatcherServlet, Spring MVC looks for a file named [servlet-name]-servlet.xml in the WEB-INF directory of your web application and creates the beans defined there...

    Your servlet is called spring-dispatcher, so it looks for /WEB-INF/spring-dispatcher-servlet.xml. You need to have this servlet configuration, and define web related beans in there (like controllers, view resolvers, etc). See the linked documentation for clarification on the relation of servlet contexts to the global application context (which is the app-config.xml in your case).

    One more thing, if you don't like the naming convention of the servlet config xml, you can specify your config explicitly:

    <servlet>
        <servlet-name>spring-dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>/WEB-INF/spring/appServlet/servlet-context.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>