Programs & Examples On #Configurable product

How to use View.OnTouchListener instead of onClick

for use sample touch listener just you need this code

public boolean onTouch(View view, MotionEvent motionEvent) {

    ClipData data = ClipData.newPlainText("", "");
    View.DragShadowBuilder shadowBuilder = new View.DragShadowBuilder(view);
    view.startDrag(data, shadowBuilder, null, 0);

    return true;

What is this property in Spring Boot?

This property will register an OpenEntityManagerInViewInterceptor, which registers an EntityManager to the current thread, so you will have the same EntityManager until the web request is finished. It has nothing to do with a Hibernate SessionFactory etc.

Fix Access denied for user 'root'@'localhost' for phpMyAdmin

What worked for me:

Go to


$cfg['Servers'][$i]['AllowNoPassword'] = true;


$cfg['Servers'][$i]['AllowNoPassword'] = false;


$cfg['Servers'][$i]['password'] = '';


$cfg['Servers'][$i]['password'] = ' ';


$cfg['Servers'][$i]['auth_type'] = 'config';


$cfg['Servers'][$i]['auth_type'] = 'http';

Reload the page http://localhost/phpmyadmin

Type : root
pass : (empty)

Now you have access to it. :)

.NET DateTime to SqlDateTime Conversion

on my quest to do this with entitie, i stumbled over here, just hitting back to post what i've found out...

when using EF4, "a sql's" datetime column can be filled from .NET's DateTime using BitConverter.

EntitieObj.thetime = BitConverter.GetBytes(DateTime.Now.ToBinary());

also Fakrudeen's link brought me further... thank you.

How to ping an IP address

Check your connectivity. On my Computer this prints REACHABLE for both IP's:

Sending Ping Request to
Host is reachable
Sending Ping Request to
Host is reachable


You could try modifying the code to use getByAddress() to obtain the address:

public static void main(String[] args) throws UnknownHostException, IOException {
    InetAddress inet;

    inet = InetAddress.getByAddress(new byte[] { 127, 0, 0, 1 });
    System.out.println("Sending Ping Request to " + inet);
    System.out.println(inet.isReachable(5000) ? "Host is reachable" : "Host is NOT reachable");

    inet = InetAddress.getByAddress(new byte[] { (byte) 173, (byte) 194, 32, 38 });
    System.out.println("Sending Ping Request to " + inet);
    System.out.println(inet.isReachable(5000) ? "Host is reachable" : "Host is NOT reachable");

The getByName() methods may attempt some kind of reverse DNS lookup which may not be possible on your machine, getByAddress() might bypass that.

How to validate an email address in JavaScript

One of my coworker shared this regex with me. I like it a lot.

function isValidEmailAddress (email) {
    var validEmail = false;
    if (email) {
        email = email.trim().toLowerCase();
        var pattern = /^[\w-']+(\.[\w-']+)*@([a-zA-Z0-9]+[a-zA-Z0-9-]+(\.[a-zA-Z0-9-]+)*?\.[a-zA-Z]{2,6}|(\d{1,3}\.){3}\d{1,3})(:\d{4})?$/;
        validEmail = pattern.exec(email);

    return validEmail;

if (typeof String.prototype.trim !== 'function') {
    String.prototype.trim = function() {
        return this.replace(/^\s+|\s+$/g, '');

what is trailing whitespace and how can I handle this?

Trailing whitespace is any spaces or tabs after the last non-whitespace character on the line until the newline.

In your posted question, there is one extra space after try:, and there are 12 extra spaces after pass:

>>> post_text = '''\
...             if self.tagname and self.tagname2 in list1:
...                 try: 
...                     question = soup.find("div", "post-text")
...                     title = soup.find("a", "question-hyperlink")
...                     self.list2.append(str(title)+str(question)+url)
...                     current += 1
...                 except AttributeError:
...                     pass            
...   "%s questions passed, %s questions \
...                 collected" % (count, current))
...             count += 1
...         return self.list2
... '''
>>> for line in post_text.splitlines():
...     if line.rstrip() != line:
...         print(repr(line))
'                try: '
'                    pass            '

See where the strings end? There are spaces before the lines (indentation), but also spaces after.

Use your editor to find the end of the line and backspace. Many modern text editors can also automatically remove trailing whitespace from the end of the line, for example every time you save a file.


Quite an old article on mssqlcity attempts to explain the types of locks:

Shared locks are used for operations that do not change or update data, such as a SELECT statement.

Update locks are used when SQL Server intends to modify a page, and later promotes the update page lock to an exclusive page lock before actually making the changes.

Exclusive locks are used for the data modification operations, such as UPDATE, INSERT, or DELETE.

What it doesn't discuss are Intent (which basically is a modifier for these lock types). Intent (Shared/Exclusive) locks are locks held at a higher level than the real lock. So, for instance, if your transaction has an X lock on a row, it will also have an IX lock at the table level (which stops other transactions from attempting to obtain an incompatible lock at a higher level on the table (e.g. a schema modification lock) until your transaction completes or rolls back).

The concept of "sharing" a lock is quite straightforward - multiple transactions can have a Shared lock for the same resource, whereas only a single transaction may have an Exclusive lock, and an Exclusive lock precludes any transaction from obtaining or holding a Shared lock.

Syntax error due to using a reserved word as a table or column name in MySQL

The Problem

In MySQL, certain words like SELECT, INSERT, DELETE etc. are reserved words. Since they have a special meaning, MySQL treats it as a syntax error whenever you use them as a table name, column name, or other kind of identifier - unless you surround the identifier with backticks.

As noted in the official docs, in section 10.2 Schema Object Names (emphasis added):

Certain objects within MySQL, including database, table, index, column, alias, view, stored procedure, partition, tablespace, and other object names are known as identifiers.


If an identifier contains special characters or is a reserved word, you must quote it whenever you refer to it.


The identifier quote character is the backtick ("`"):

A complete list of keywords and reserved words can be found in section 10.3 Keywords and Reserved Words. In that page, words followed by "(R)" are reserved words. Some reserved words are listed below, including many that tend to cause this issue.

  • ADD
  • AND
  • BY
  • CALL
  • CASE
  • DESC
  • FROM
  • IN
  • IS
  • KEY
  • LIKE
  • LONG
  • NOT
  • OR
  • RANK
  • TO

The Solution

You have two options.

1. Don't use reserved words as identifiers

The simplest solution is simply to avoid using reserved words as identifiers. You can probably find another reasonable name for your column that is not a reserved word.

Doing this has a couple of advantages:

  • It eliminates the possibility that you or another developer using your database will accidentally write a syntax error due to forgetting - or not knowing - that a particular identifier is a reserved word. There are many reserved words in MySQL and most developers are unlikely to know all of them. By not using these words in the first place, you avoid leaving traps for yourself or future developers.

  • The means of quoting identifiers differs between SQL dialects. While MySQL uses backticks for quoting identifiers by default, ANSI-compliant SQL (and indeed MySQL in ANSI SQL mode, as noted here) uses double quotes for quoting identifiers. As such, queries that quote identifiers with backticks are less easily portable to other SQL dialects.

Purely for the sake of reducing the risk of future mistakes, this is usually a wiser course of action than backtick-quoting the identifier.

2. Use backticks

If renaming the table or column isn't possible, wrap the offending identifier in backticks (`) as described in the earlier quote from 10.2 Schema Object Names.

An example to demonstrate the usage (taken from 10.3 Keywords and Reserved Words):

mysql> CREATE TABLE interval (begin INT, end INT);
ERROR 1064 (42000): You have an error in your SQL syntax.
near 'interval (begin INT, end INT)'

mysql> CREATE TABLE `interval` (begin INT, end INT); Query OK, 0 rows affected (0.01 sec)

Similarly, the query from the question can be fixed by wrapping the keyword key in backticks, as shown below:

INSERT INTO user_details (username, location, `key`)
VALUES ('Tim', 'Florida', 42)";               ^   ^

How do you fix a bad merge, and replay your good commits onto a fixed merge?

Please don't use this recipe if your situation is not the one described in the question. This recipe is for fixing a bad merge, and replaying your good commits onto a fixed merge.

Although filter-branch will do what you want, it is quite a complex command and I would probably choose to do this with git rebase. It's probably a personal preference. filter-branch can do it in a single, slightly more complex command, whereas the rebase solution is performing the equivalent logical operations one step at a time.

Try the following recipe:

# create and check out a temporary branch at the location of the bad merge
git checkout -b tmpfix <sha1-of-merge>

# remove the incorrectly added file
git rm somefile.orig

# commit the amended merge
git commit --amend

# go back to the master branch
git checkout master

# replant the master branch onto the corrected merge
git rebase tmpfix

# delete the temporary branch
git branch -d tmpfix

(Note that you don't actually need a temporary branch, you can do this with a 'detached HEAD', but you need to take a note of the commit id generated by the git commit --amend step to supply to the git rebase command rather than using the temporary branch name.)

What is the iOS 6 user agent string?

Some more:

Mozilla/5.0 (iPhone; CPU iPhone OS 6_1_3 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) Version/6.0 Mobile/10B329 Safari/8536.25

Mozilla/5.0 (iPhone; CPU iPhone OS 6_1_4 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) Version/6.0 Mobile/10B350 Safari/8536.25

Numpy matrix to array

First, Mv = numpy.asarray(M.T), which gives you a 4x1 but 2D array.

Then, perform A = Mv[0,:], which gives you what you want. You could put them together, as numpy.asarray(M.T)[0,:].

Finding the layers and layer sizes for each Docker image

It's indeed doable to query the manifest or blob info from docker registry server without pulling the image to local disk.

You can refer to the Registry v2 API to fetch the manifest of image.

GET /v2/<name>/manifests/<reference>

Note, you have to handle different manifest version. For v2 you can directly get the size of layer and digest of blob. For v1 manifest, you can HEAD the blob download url to get the actual layer size.

There is a simple script for handling above cases that will be continuously maintained.

Path to Powershell.exe (v 2.0)

I think $PsHome has the information you're after?

PS .> $PsHome

PS .> Get-Help about_automatic_variables

    about_Automatic_Variables ...

How to install XNA game studio on Visual Studio 2012?

There seems to be some confusion over how to get this set up for the Express version specifically. Using the Windows Desktop (WD) version of VS Express 2012, I followed the instructions in Steve B's and Rick Martin's answers with the modifications below.

  • In step 2 rather than copying to "C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE\Extensions\Microsoft\XNA Game Studio 4.0", copy to "C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE\WDExpressExtensions\Microsoft\XNA Game Studio 4.0"
  • In step 4, after making the changes also add the line <Edition>WDExpress</Edition> (you should be able to see where it makes sense)
  • In step 5, replace devenv.exe with WDExpress.exe
  • In Rick Martin's step, replace "%LocalAppData%\Microsoft\VisualStudio\11.0\Extensions" with "%LocalAppData%\Microsoft\WDExpress\11.0\Extensions"

I haven't done a lot of work since then, but I did manage to create a new game project and it seems fine so far.

Why does my 'git branch' have no master?

In my case there was a develop branch but no master branch. Therefore I cloned the repository pointing the newly created HEAD to the existing branch. Then I created the missing master branch and update HEAD to point to the new master branch.

git clone git:repositoryname --branch otherbranch
git checkout -b master
git update-ref HEAD master
git push --set-upstream origin master

jquery get height of iframe content when loaded

This's a jQuery free solution that can work with SPA inside the iframe

document.getElementById('iframe-id').addEventListener('load', function () {
  let that = this;
  setTimeout(function () { = that.contentWindow.document.body.offsetHeight + 'px';
  }, 2000) // if you're having SPA framework (angularjs for example) inside the iframe, some delay is needed for the content to populate

How to convert string to double with proper cultureinfo

Use InvariantCulture. The decimal separator is always "." eventually you can replace "," by "." When you display the result , use your local culture. But internally use always invariant culture

TryParse does not allway work as we would expect There are change request in .net in this area:

Can I edit an iPad's host file?

You can also make use of a proxy server on your iPhone or iPade via mobile internet (3G) by using a iPhone Mobile proxy generator:

Just enter the apn of your carrier (with apn username/password if needed) and the proxy server you want to go through and tap Generate

Concatenate in jQuery Selector

Your concatenation syntax is correct.

Most likely the callback function isn't even being called. You can test that by putting an alert(), console.log() or debugger line in that function.

If it isn't being called, most likely there's an AJAX error. Look at chaining a .fail() handler after $.post() to find out what the error is, e.g.:

$.post('ajaxskeleton.php', {
    red: text       
}, function(){
    $('#part' + number).html(text);
}).fail(function(jqXHR, textStatus, errorThrown) {

SQLite Query in Android to count rows

Assuming you already have a Database (db) connection established, I think the most elegant way is to stick to the Cursor class, and do something like:

String selection = "uname = ? AND pwd = ?";
String[] selectionArgs = {loginname, loginpass};
String tableName = "YourTable";
Cursor c = db.query(tableName, null, selection, selectionArgs, null, null, null);
int result = c.getCount();
return result;

Number of visitors on a specific page

If you want to know the number of visitors (as is titled in the question) and not the number of pageviews, then you'll need to create a custom report.



Google Analytics has changed the terminology they use within the reports. Now, visits is named "sessions" and unique visitors is named "users."

User - A unique person who has visited your website. Users may visit your website multiple times, and they will only be counted once.

Session - The number of different times that a visitor came to your site.

Pageviews - The total number of pages that a user has accessed.


Creating a Custom Report

  1. To create a custom report, click on the "Customization" item in the left navigation menu, and then click on "Custom Reports".

customization item expanded in navigation menu

  1. The "Create Custom Report" page will open.
  2. Enter a name for your report.
  3. In the "Metric Groups" section, enter either "Users" or "Sessions" depending on what information you want to collect (see Terminology, above).
  4. In the "Dimension Drilldowns" section, enter "Page".
  5. Under "Filters" enter the individual page (exact) or group of pages (using regex) that you would like to see the data for. enter image description here
  6. Save the report and run it.

How to fix height of TR?

Your table width is 90% which is relative to it's container.

If you squeeze the page, you are probably squeezing the table width as well. The width of the cells reduce too and the browser compensate by increasing the height.

To have the height untouched, you have to make sure the widths of the cells can hold the intented content. Fixing the table width is probably something you want to try. Or perhaps play around with the min-width of the table.

AWS S3 CLI - Could not connect to the endpoint URL

first you use 'aws configure' then input the access key, and secret key, and the region. the region you input would be important for this problem. try to input something like '', not ''. it will solve the issue.

CodeIgniter Active Record not equal

Try this code. This seems working in my case.

$this->db->where(array('id !='=> $id))

When can I use a forward declaration?

As long as you don't need the definition (think pointers and references) you can get away with forward declarations. This is why mostly you'd see them in headers while implementation files typically will pull the header for the appropriate definition(s).

What is the point of "final class" in Java?

In Java, items with the final modifier cannot be changed!

This includes final classes, final variables, and final methods:

  • A final class cannot be extended by any other class
  • A final variable cannot be reassigned another value
  • A final method cannot be overridden

Django request get parameters

You can use [] to extract values from a QueryDict object like you would any ordinary dictionary.

# HTTP POST variables
request.POST['section'] # => [39]
request.POST['MAINS'] # => [137]

# HTTP GET variables
request.GET['section'] # => [39]
request.GET['MAINS'] # => [137]

# HTTP POST and HTTP GET variables (Deprecated since Django 1.7)
request.REQUEST['section'] # => [39]
request.REQUEST['MAINS'] # => [137]

How to use youtube-dl from a python program?

If youtube-dl is a terminal program, you can use the subprocess module to access the data you want.

Check out this link for more details: Calling an external command in Python

jQuery 'input' event

Occurs when the text content of an element is changed through the user interface.

It's not quite an alias for keyup because keyup will fire even if the key does nothing (for example: pressing and then releasing the Control key will trigger a keyup event).

A good way to think about it is like this: it's an event that triggers whenever the input changes. This includes -- but is not limited to -- pressing keys which modify the input (so, for example, Ctrl by itself will not trigger the event, but Ctrl-V to paste some text will), selecting an auto-completion option, Linux-style middle-click paste, drag-and-drop, and lots of other things.

See this page and the comments on this answer for more details.

Add line break to 'git commit -m' from the command line

Personally, I find it easiest to modify commit messages after the fact in vi (or whatever your git editor of choice is) rather than on the command line, by doing git commit --amend right after git commit.

How to access POST form fields

For Express 4.1 and above

As most of the answers are using to Express, bodyParser, connect; where multipart is deprecated. There is a secure way to send post multipart objects easily.

Multer can be used as replacement for connect.multipart().

To install the package

$ npm install multer

Load it in your app:

var multer = require('multer');

And then, add it in the middleware stack along with the other form parsing middleware.

app.use(multer({ dest: './uploads/' }));

connect.json() handles application/json

connect.urlencoded() handles application/x-www-form-urlencoded

multer() handles multipart/form-data

Python: How to increase/reduce the fontsize of x and y tick labels?

You can set the fontsize directly in the call to set_xticklabels and set_yticklabels (as noted in previous answers). This will only affect one Axes at a time.

ax.set_xticklabels(x_ticks, rotation=0, fontsize=8)
ax.set_yticklabels(y_ticks, rotation=0, fontsize=8)

You can also set the ticklabel font size globally (i.e. for all figures/subplots in a script) using rcParams:

import matplotlib.pyplot as plt


Or, equivalently:


Finally, if this is a setting that you would like to be set for all your matplotlib plots, you could also set these two rcParams in your matplotlibrc file:

xtick.labelsize      : 8 # fontsize of the x tick labels
ytick.labelsize      : 8 # fontsize of the y tick labels

CSS get height of screen resolution

You can bind the current height and width of the screen to css variables: var(--screen-x) and var(--screen-y) with this javascript:

var root = document.documentElement;

document.addEventListener('resize', () => {'--screen-x', window.screenX)'--screen-y', window.screenY)

This was directly adapted from lea verou's example in her talk on css variables here:

How do I "select Android SDK" in Android Studio?

Sometimes android studio just acts stupid and needs some kind of reset..

Go to settings.gradle file it should contain include ':app'
change it to include ':ap' and sync.
after sync, change it to include ':app' again.

It should be working OK now.

How to count instances of character in SQL Column

This gave me accurate results every time...

This is in my Stripes field...

Yellow, Yellow, Yellow, Yellow, Yellow, Yellow, Black, Yellow, Yellow, Red, Yellow, Yellow, Yellow, Black

  • 11 Yellows
  • 2 Black
  • 1 Red
SELECT (LEN(Stripes) - LEN(REPLACE(Stripes, 'Red', ''))) / LEN('Red') 
  FROM t_Contacts

How to count rows with SELECT COUNT(*) with SQLAlchemy?

I needed to do a count of a very complex query with many joins. I was using the joins as filters, so I only wanted to know the count of the actual objects. count() was insufficient, but I found the answer in the docs here:

The code would look something like this (to count user objects):

from sqlalchemy import func


What's the best way to test SQL Server connection programmatically?

I have had a difficulty with the EF when the connection the server is stopped or paused, and I raised the same question. So for completeness to the above answers here is the code.

/// <summary>
/// Test that the server is connected
/// </summary>
/// <param name="connectionString">The connection string</param>
/// <returns>true if the connection is opened</returns>
private static bool IsServerConnected(string connectionString)
    using (SqlConnection connection = new SqlConnection(connectionString))
            return true;
        catch (SqlException)
            return false;

What does "while True" mean in Python?

while True:

means infinite loop.

The while statement is often used of a finite loop. But using the constant 'True' guarantees the repetition of the while statement without the need to control the loop (setting a boolean value inside the iteration for example), unless you want to break it.

In fact

True == (1 == 1)

mysqli_connect(): (HY000/2002): No connection could be made because the target machine actively refused it

You have entered wrong port number 3360 instead of 3306. You dont need to write database port number if you are using daefault (3306 in case of MySQL)

open resource with relative path in Java

Use this:


Can I stop 100% Width Text Boxes from extending beyond their containers?

Just came across this problem myself, and the only solution I could find that worked in all my test browsers (IE6, IE7, Firefox) was the following:

  1. Wrap the input field in two separate DIVs
  2. Set the outer DIV to width 100%, this prevents our container from overflowing the document
  3. Put padding in the inner DIV of the exact amount to compensate for the horizontal overflow of the input.
  4. Set custom padding on the input so it overflows by the same amount as I allowed for in the inner DIV

The code:

<div style="width: 100%">
    <div style="padding-right: 6px;">
        <input type="text" style="width: 100%; padding: 2px; margin: 0;
                                  border : solid 1px #999" />

Here, the total horizontal overflow for the input element is 6px - 2x(padding + border) - so we set a padding-right for the inner DIV of 6px.

How can I set the default value for an HTML <select> element?

This code sets the default value for the HTML select element with PHP.

<select name="hall" id="hall">
    $default = 3;
    $nr = 1;
    while($nr < 10){
        if($nr == $default){
            echo "<option selected=\"selected\">". $nr ."</option>";
            echo "<option>". $nr ."</option>";

jQuery OR Selector?

Using a comma may not be sufficient if you have multiple jQuery objects that need to be joined.

The .add() method adds the selected elements to the result set:

// classA OR classB

It's more verbose than '.classA, .classB', but lets you build more complex selectors like the following:

// (classA which has <p> descendant) OR (<div> ancestors of classB)

Validate SSL certificates with Python

You can use Twisted to verify certificates. The main API is CertificateOptions, which can be provided as the contextFactory argument to various functions such as listenSSL and startTLS.

Unfortunately, neither Python nor Twisted comes with a the pile of CA certificates required to actually do HTTPS validation, nor the HTTPS validation logic. Due to a limitation in PyOpenSSL, you can't do it completely correctly just yet, but thanks to the fact that almost all certificates include a subject commonName, you can get close enough.

Here is a naive sample implementation of a verifying Twisted HTTPS client which ignores wildcards and subjectAltName extensions, and uses the certificate-authority certificates present in the 'ca-certificates' package in most Ubuntu distributions. Try it with your favorite valid and invalid certificate sites :).

import os
import glob
from OpenSSL.crypto import load_certificate, FILETYPE_PEM
from twisted.python.urlpath import URLPath
from twisted.internet.ssl import ContextFactory
from twisted.internet import reactor
from twisted.web.client import getPage
certificateAuthorityMap = {}
for certFileName in glob.glob("/etc/ssl/certs/*.pem"):
    # There might be some dead symlinks in there, so let's make sure it's real.
    if os.path.exists(certFileName):
        data = open(certFileName).read()
        x509 = load_certificate(FILETYPE_PEM, data)
        digest = x509.digest('sha1')
        # Now, de-duplicate in case the same cert has multiple names.
        certificateAuthorityMap[digest] = x509
class HTTPSVerifyingContextFactory(ContextFactory):
    def __init__(self, hostname):
        self.hostname = hostname
    isClient = True
    def getContext(self):
        ctx = Context(TLSv1_METHOD)
        store = ctx.get_cert_store()
        for value in certificateAuthorityMap.values():
        ctx.set_verify(VERIFY_PEER | VERIFY_FAIL_IF_NO_PEER_CERT, self.verifyHostname)
        return ctx
    def verifyHostname(self, connection, x509, errno, depth, preverifyOK):
        if preverifyOK:
            if self.hostname != x509.get_subject().commonName:
                return False
        return preverifyOK
def secureGet(url):
    return getPage(url, HTTPSVerifyingContextFactory(URLPath.fromString(url).netloc))
def done(result):
    print 'Done!', len(result)

sqlite3.OperationalError: unable to open database file

use this type it works for me . windows 7 with python 2.7 and django 1.5

'ENGINE': 'django.db.backends.sqlite3',
'NAME': 'C:\\tool\\mysite\\data.db',

hope its works...

How to print variables without spaces between values

It's the comma which is providing that extra white space.

One way is to use the string % method:

print 'Value is "%d"' % (value)

which is like printf in C, allowing you to incorporate and format the items after % by using format specifiers in the string itself. Another example, showing the use of multiple values:

print '%s is %3d.%d' % ('pi', 3, 14159)

For what it's worth, Python 3 greatly improves the situation by allowing you to specify the separator and terminator for a single print call:

>>> print(1,2,3,4,5)
1 2 3 4 5

>>> print(1,2,3,4,5,end='<<\n')
1 2 3 4 5<<

>>> print(1,2,3,4,5,sep=':',end='<<\n')

How do I use method overloading in Python?

It's method overloading, not method overriding. And in Python, you do it all in one function:

class A:

    def stackoverflow(self, i='some_default_value'):
        print 'only method'


You can't have two methods with the same name in Python -- and you don't need to.

See the Default Argument Values section of the Python tutorial. See "Least Astonishment" and the Mutable Default Argument for a common mistake to avoid.

See PEP 443 for information about the new single dispatch generic functions in Python 3.4.

How to use sudo inside a docker container?

If SUDO or apt-get is not accessible inside the Container, You can use, below option in running container.

docker exec -u root -it f83b5c5bf413 ash

"f83b5c5bf413" is my container ID & here is working example from my terminal:

enter image description here

bootstrap 3 wrap text content within div for horizontal alignment

Now Update word-wrap is replace by :


Compatible old navigator and css 3 it's good alternative !

it's evolution of word-wrap ( since 2012... )

See more information :

See compatibility full :

Recursion in Python? RuntimeError: maximum recursion depth exceeded while calling a Python object

Python lacks the tail recursion optimizations common in functional languages like lisp. In Python, recursion is limited to 999 calls (see sys.getrecursionlimit).

If 999 depth is more than you are expecting, check if the implementation lacks a condition that stops recursion, or if this test may be wrong for some cases.

I dare to say that in Python, pure recursive algorithm implementations are not correct/safe. A fib() implementation limited to 999 is not really correct. It is always possible to convert recursive into iterative, and doing so is trivial.

It is not reached often because in many recursive algorithms the depth tend to be logarithmic. If it is not the case with your algorithm and you expect recursion deeper than 999 calls you have two options:

1) You can change the recursion limit with sys.setrecursionlimit(n) until the maximum allowed for your platform:


Set the maximum depth of the Python interpreter stack to limit. This limit prevents infinite recursion from causing an overflow of the C stack and crashing Python.

The highest possible limit is platform-dependent. A user may need to set the limit higher when she has a program that requires deep recursion and a platform that supports a higher limit. This should be done with care, because a too-high limit can lead to a crash.

2) You can try to convert the algorithm from recursive to iterative. If recursion depth is bigger than allowed by your platform, it is the only way to fix the problem. There are step by step instructions on the Internet and it should be a straightforward operation for someone with some CS education. If you are having trouble with that, post a new question so we can help.

No module named MySQLdb

I have tried methods above, but still no module named 'MySQLdb', finally, I succeed with

easy_install mysql-python

my env is unbuntu 14.04

Variables declared outside function

When Python parses a function, it notes when a variable assignment is made. When there is an assignment, it assumes by default that that variable is a local variable. To declare that the assignment refers to a global variable, you must use the global declaration.

When you access a variable in a function, its value is looked up using the LEGB scoping rules.

So, the first example

  x = 1
  def inc():
      x += 5

produces an UnboundLocalError because Python determined x inside inc to be a local variable,

while accessing x works in your second example

 def inc():
    print x

because here, in accordance with the LEGB rule, Python looks for x in the local scope, does not find it, then looks for it in the extended scope, still does not find it, and finally looks for it in the global scope successfully.

JAVA Unsupported major.minor version 51.0

This is because of a higher JDK during compile time and lower JDK during runtime. So you just need to update your JDK version, possible to JDK 7

You may also check Unsupported major.minor version 51.0

Call a function with argument list in python

A small addition to previous answers, since I couldn't find a solution for a problem, which is not worth opening a new question, but led me here.

Here is a small code snippet, which combines lists, zip() and *args, to provide a wrapper that can deal with an unknown amount of functions with an unknown amount of arguments.

def f1(var1, var2, var3):

def f2(var1, var2):

def f3():
    print('f3, empty')

def wrapper(a,b, func_list, arg_list):
    for f,var in zip(func_list,arg_list):

f_list = [f1, f2, f3]
a_list = [[1,2,3], [4,5], []]

wrapper('begin', 'end', f_list, a_list)

Keep in mind, that zip() does not provide a safety check for lists of unequal length, see zip iterators asserting for equal length in python.

What is

To install a Python package you've downloaded, you extract the archive and run the script inside:

python install

To me, this has always felt odd. It would be more natural to point a package manager at the download, as one would do in Ruby and Nodejs, eg. gem install rails-4.1.1.gem

A package manager is more comfortable too, because it's familiar and reliable. On the other hand, each is novel, because it's specific to the package. It demands faith in convention "I trust this takes the same commands as others I have used in the past". That's a regrettable tax on mental willpower.

I'm not saying the workflow is less secure than a package manager (I understand Pip just runs the inside), but certainly I feel it's awkard and jarring. There's a harmony to commands all being to the same package manager application. You might even grow fond it.

phpMyAdmin is throwing a #2002 cannot log in to the mysql server phpmyadmin

Did you set up the MySQL on your machine? It sounds like you're using Windows; MySQL runs as a "Service" on your machine (right-click My Computer -> Manage -> Services).

Handler "ExtensionlessUrlHandler-Integrated-4.0" has a bad module "ManagedPipelineHandler" in its module list

In my case (Windows 10 + IIS 10) i had to open "Turn Windows Features On or Off" and then go to Internet Information Services > World Wide Web Services > Application Development Features > and check ASP.NET 4.6

Postgres: clear entire database before re-creating / re-populating from bash script

Note: my answer is about really deleting the tables and other database objects; for deleting all data in the tables, i.e. truncating all tables, Endre Both has provided a similarily well-executed (direct execution) statement a month later.

For the cases where you can’t just DROP SCHEMA public CASCADE;, DROP OWNED BY current_user; or something, here’s a stand-alone SQL script I wrote, which is transaction-safe (i.e. you can put it between BEGIN; and either ROLLBACK; to just test it out or COMMIT; to actually do the deed) and cleans up “all” database objects… well, all those used in the database our application uses or I could sensibly add, which is:

  • triggers on tables
  • constraints on tables (FK, PK, CHECK, UNIQUE)
  • indices
  • VIEWs (normal or materialised)
  • tables
  • sequences
  • routines (aggregate functions, functions, procedures)
  • all non-default (i.e. not public or DB-internal) schemata “we” own: the script is useful when run as “not a database superuser”; a superuser can drop all schemata (the really important ones are still explicitly excluded, though)
  • extensions (user-contributed but I normally deliberately leave them in)

Not dropped are (some deliberate; some only because I had no example in our DB):

  • the public schema (e.g. for extension-provided stuff in them)
  • collations and other locale stuff
  • event triggers
  • text search stuff, … (see here for other stuff I might have missed)
  • roles or other security settings
  • composite types
  • toast tables
  • FDW and foreign tables

This is really useful for the cases when the dump you want to restore is of a different database schema version (e.g. with Debian dbconfig-common, Flyway or Liquibase/DB-Manul) than the database you want to restore it into.

I’ve also got a version which deletes “everything except two tables and what belongs to them” (a sequence, tested manually, sorry, I know, boring) in case someone is interested; the diff is small. Contact me or check this repo if interested.


-- Copyright © 2019, 2020
--      mirabilos <[email protected]>
-- Provided that these terms and disclaimer and all copyright notices
-- are retained or reproduced in an accompanying document, permission
-- is granted to deal in this work without restriction, including un-
-- limited rights to use, publicly perform, distribute, sell, modify,
-- merge, give away, or sublicence.
-- This work is provided “AS IS” and WITHOUT WARRANTY of any kind, to
-- the utmost extent permitted by applicable law, neither express nor
-- implied; without malicious intent or gross negligence. In no event
-- may a licensor, author or contributor be held liable for indirect,
-- direct, other damage, loss, or other issues arising in any way out
-- of dealing in the work, even if advised of the possibility of such
-- damage or existence of a defect, except proven that it results out
-- of said person’s immediate fault when using the work as intended.
-- -
-- Drop everything from the PostgreSQL database.

DO $$
        q TEXT;
        r RECORD;
        -- triggers
        FOR r IN (SELECT pns.nspname, pc.relname, pt.tgname
                FROM pg_catalog.pg_trigger pt, pg_catalog.pg_class pc, pg_catalog.pg_namespace pns
                WHERE pns.oid=pc.relnamespace AND pc.oid=pt.tgrelid
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pt.tgisinternal=false
            ) LOOP
                EXECUTE format('DROP TRIGGER %I ON %I.%I;',
                    r.tgname, r.nspname, r.relname);
        END LOOP;
        -- constraints #1: foreign key
        FOR r IN (SELECT pns.nspname, pc.relname, pcon.conname
                FROM pg_catalog.pg_constraint pcon, pg_catalog.pg_class pc, pg_catalog.pg_namespace pns
                WHERE pns.oid=pc.relnamespace AND pc.oid=pcon.conrelid
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pcon.contype='f'
            ) LOOP
                EXECUTE format('ALTER TABLE ONLY %I.%I DROP CONSTRAINT %I;',
                    r.nspname, r.relname, r.conname);
        END LOOP;
        -- constraints #2: the rest
        FOR r IN (SELECT pns.nspname, pc.relname, pcon.conname
                FROM pg_catalog.pg_constraint pcon, pg_catalog.pg_class pc, pg_catalog.pg_namespace pns
                WHERE pns.oid=pc.relnamespace AND pc.oid=pcon.conrelid
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pcon.contype<>'f'
            ) LOOP
                EXECUTE format('ALTER TABLE ONLY %I.%I DROP CONSTRAINT %I;',
                    r.nspname, r.relname, r.conname);
        END LOOP;
        -- indices
        FOR r IN (SELECT pns.nspname, pc.relname
                FROM pg_catalog.pg_class pc, pg_catalog.pg_namespace pns
                WHERE pns.oid=pc.relnamespace
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pc.relkind='i'
            ) LOOP
                EXECUTE format('DROP INDEX %I.%I;',
                    r.nspname, r.relname);
        END LOOP;
        -- normal and materialised views
        FOR r IN (SELECT pns.nspname, pc.relname
                FROM pg_catalog.pg_class pc, pg_catalog.pg_namespace pns
                WHERE pns.oid=pc.relnamespace
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pc.relkind IN ('v', 'm')
            ) LOOP
                EXECUTE format('DROP VIEW %I.%I;',
                    r.nspname, r.relname);
        END LOOP;
        -- tables
        FOR r IN (SELECT pns.nspname, pc.relname
                FROM pg_catalog.pg_class pc, pg_catalog.pg_namespace pns
                WHERE pns.oid=pc.relnamespace
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pc.relkind='r'
            ) LOOP
                EXECUTE format('DROP TABLE %I.%I;',
                    r.nspname, r.relname);
        END LOOP;
        -- sequences
        FOR r IN (SELECT pns.nspname, pc.relname
                FROM pg_catalog.pg_class pc, pg_catalog.pg_namespace pns
                WHERE pns.oid=pc.relnamespace
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pc.relkind='S'
            ) LOOP
                EXECUTE format('DROP SEQUENCE %I.%I;',
                    r.nspname, r.relname);
        END LOOP;
        -- extensions (only if necessary; keep them normally)
        FOR r IN (SELECT pns.nspname, pe.extname
                FROM pg_catalog.pg_extension pe, pg_catalog.pg_namespace pns
                WHERE pns.oid=pe.extnamespace
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
            ) LOOP
                EXECUTE format('DROP EXTENSION %I;', r.extname);
        END LOOP;
        -- aggregate functions first (because they depend on other functions)
        FOR r IN (SELECT pns.nspname, pp.proname, pp.oid
                FROM pg_catalog.pg_proc pp, pg_catalog.pg_namespace pns, pg_catalog.pg_aggregate pagg
                WHERE pns.oid=pp.pronamespace
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
                    AND pagg.aggfnoid=pp.oid
            ) LOOP
                EXECUTE format('DROP AGGREGATE %I.%I(%s);',
                    r.nspname, r.proname,
        END LOOP;
        -- routines (functions, aggregate functions, procedures, window functions)
        IF EXISTS (SELECT * FROM pg_catalog.pg_attribute
                WHERE attrelid='pg_catalog.pg_proc'::regclass
                    AND attname='prokind' -- PostgreSQL 11+
            ) THEN
                q := 'CASE pp.prokind
                        WHEN ''p'' THEN ''PROCEDURE''
                        WHEN ''a'' THEN ''AGGREGATE''
                        ELSE ''FUNCTION''
        ELSIF EXISTS (SELECT * FROM pg_catalog.pg_attribute
                WHERE attrelid='pg_catalog.pg_proc'::regclass
                    AND attname='proisagg' -- PostgreSQL =10
            ) THEN
                q := 'CASE pp.proisagg
                        WHEN true THEN ''AGGREGATE''
                        ELSE ''FUNCTION''
                q := '''FUNCTION''';
        END IF;
        FOR r IN EXECUTE 'SELECT pns.nspname, pp.proname, pp.oid, ' || q || ' AS pt
                FROM pg_catalog.pg_proc pp, pg_catalog.pg_namespace pns
                WHERE pns.oid=pp.pronamespace
                    AND pns.nspname NOT IN (''information_schema'', ''pg_catalog'', ''pg_toast'')
            ' LOOP
                EXECUTE format('DROP %s %I.%I(%s);',,
                    r.nspname, r.proname,
        END LOOP;
        -- non-default schemata we own; assume to be run by a not-superuser
        FOR r IN (SELECT pns.nspname
                FROM pg_catalog.pg_namespace pns, pg_catalog.pg_roles pr
                WHERE pr.oid=pns.nspowner
                    AND pns.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast', 'public')
                    AND pr.rolname=current_user
            ) LOOP
                EXECUTE format('DROP SCHEMA %I;', r.nspname);
        END LOOP;
        -- voilà
        RAISE NOTICE 'Database cleared!';
END; $$;

Tested, except later additions (extensions contributed by Clément Prévost), on PostgreSQL 9.6 (jessie-backports). Aggregate removal tested on 9.6 and 12.2, procedure removal tested on 12.2 as well. Bugfixes and further improvements welcome!

How to uninstall Ruby from /usr/local?

do this way :

sudo apt purge ruby

Replace CRLF using powershell

For CMD one line LF-only:

powershell -NoProfile -command "((Get-Content 'prueba1.txt') -join \"`n\") + \"`n\" | Set-Content -NoNewline 'prueba1.txt'"

so you can create a .bat

JavaScript file not updating no matter what I do

A little late to the party, but if you put this in your html, it will keep your website from updating the cache. It takes the website a little longer to load, but for debugging purposes i like it. Taken from this answer: How to programmatically empty browser cache?

<meta http-equiv='cache-control' content='no-cache'>
<meta http-equiv='expires' content='0'>
<meta http-equiv='pragma' content='no-cache'>

Easy way to print Perl array? (with a little formatting)

I've not tried to run below, though. I think this's a tricky way.

map{print $_;} @array;

Histogram with Logarithmic Scale and custom breaks

I've put together a function that behaves identically to hist in the default case, but accepts the log argument. It uses several tricks from other posters, but adds a few of its own. hist(x) and myhist(x) look identical.

The original problem would be solved with:

myhist(mydata$V3, breaks=c(0,1,2,3,4,5,25), log="xy")

The function:

myhist <- function(x, ..., breaks="Sturges",
                   main = paste("Histogram of", xname),
                   xlab = xname,
                   ylab = "Frequency") {
  xname = paste(deparse(substitute(x), 500), collapse="\n")
  h = hist(x, breaks=breaks, plot=FALSE)
  plot(h$breaks, c(NA,h$counts), type='S', main=main,
       xlab=xlab, ylab=ylab, axes=FALSE, ...)
  lines(h$breaks, c(h$counts,NA), type='s')
  lines(h$breaks, c(NA,h$counts), type='h')
  lines(h$breaks, c(h$counts,NA), type='h')
  lines(h$breaks, rep(0,length(h$breaks)), type='S')

Exercise for the reader: Unfortunately, not everything that works with hist works with myhist as it stands. That should be fixable with a bit more effort, though.

How best to determine if an argument is not sent to the JavaScript function

fnCalledFunction(Param1,Param2, window.YourOptionalParameter)

If above function is called from many places and you are sure first 2 parameters are passed from every where but not sure about 3rd parameter then you can use window.

window.param3 will handle if it is not defined from the caller method.

Disable and enable buttons in C#

button2.Enabled == true ;

should be

button2.Enabled = true ;

JavaScript Object Id

If you want to lookup/associate an object with a unique identifier without modifying the underlying object, you can use a WeakMap:

// Note that object must be an object or array,
// NOT a primitive value like string, number, etc.
var objIdMap=new WeakMap, objectCount = 0;
function objectId(object){
  if (!objIdMap.has(object)) objIdMap.set(object,++objectCount);
  return objIdMap.get(object);

var o1={}, o2={}, o3={a:1}, o4={a:1};
console.log( objectId(o1) ) // 1
console.log( objectId(o2) ) // 2
console.log( objectId(o1) ) // 1
console.log( objectId(o3) ) // 3
console.log( objectId(o4) ) // 4
console.log( objectId(o3) ) // 3

Using a WeakMap instead of Map ensures that the objects can still be garbage-collected.

Log all requests from the python-requests module

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

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

How to resize Twitter Bootstrap modal dynamically based on the content

Simple Css work for me

.modal-dialog { 
max-width : 100% ;

How do you determine a processing time in Python?

Building on and updating a number of earlier responses (thanks: SilentGhost, nosklo, Ramkumar) a simple portable timer would use timeit's default_timer():

>>> import timeit
>>> tic=timeit.default_timer()
>>> # Do Stuff
>>> toc=timeit.default_timer()
>>> toc - tic #elapsed time in seconds

This will return the elapsed wall clock (real) time, not CPU time. And as described in the timeit documentation chooses the most precise available real-world timer depending on the platform.

ALso, beginning with Python 3.3 this same functionality is available with the time.perf_counter performance counter. Under 3.3+ timeit.default_timer() refers to this new counter.

For more precise/complex performance calculations, timeit includes more sophisticated calls for automatically timing small code snippets including averaging run time over a defined set of repetitions.

Linux delete file with size 0

You can use the command find to do this. We can match files with -type f, and match empty files using -size 0. Then we can delete the matches with -delete.

find . -type f -size 0 -delete

How to configure PHP to send e-mail?

Use PHPMailer instead:

How to use it:

$mail=new PHPMailer();
$mail->CharSet = 'UTF-8';

$body = 'This is the message';

$mail->Host       = '';

$mail->SMTPSecure = 'tls';
$mail->Port       = 587;
$mail->SMTPDebug  = 1;
$mail->SMTPAuth   = true;

$mail->Username   = '[email protected]';
$mail->Password   = '123!@#';

$mail->SetFrom('[email protected]', $name);
$mail->AddReplyTo('[email protected]','no-reply');
$mail->Subject    = 'subject';

$mail->AddAddress('[email protected]', 'title1');
$mail->AddAddress('[email protected]', 'title2'); /* ... */


Clearfix with twitter bootstrap

clearfix should contain the floating elements but in your html you have added clearfix only after floating right that is your pull-right so you should do like this:

<div class="clearfix">
  <div id="sidebar">
  <div id="main">
      <div class="pull-right">
  <div>MOVED BELOW Z</div>

see this demo

Happy to know you solved the problem by setting overflow properties. However this is also good idea to clear the float. Where you have floated your elements you could add overflow: hidden; as you have done in your main.

My prerelease app has been "processing" for over a week in iTunes Connect, what gives?

Solution is Wait for some hours Approximately 24 Hours. Your issue will be fixed at once. Apple is having bad times now a days. I hope they will soon fix everything

Python method for reading keypress?

I was also trying to achieve this. From above codes, what I understood was that you can call getch() function multiple times in order to get both bytes getting from the function. So the ord() function is not necessary if you are just looking to use with byte objects.

while True :
    if m.kbhit() :
        k = m.getch()
        if b'\r' == k :
        elif k == b'\x08'or k == b'\x1b':
            # b'\x08' => BACKSPACE
            # b'\x1b' => ESC
        elif k == b'\xe0' or k == b'\x00':
            k = m.getch()
            if k in [b'H',b'M',b'K',b'P',b'S',b'\x08']:
                # b'H' => UP ARROW
                # b'M' => RIGHT ARROW
                # b'K' => LEFT ARROW
                # b'P' => DOWN ARROW
                # b'S' => DELETE

This code will work print any key until enter key is pressed in CMD or IDE (I was using VS CODE) You can customize inside the if for specific keys if needed

Static vs class functions/variables in Swift classes?

There's one more difference. class can be used to define type properties of computed type only. If you need a stored type property use static instead.

Class :- reference type

struct :- value type

How to set cellpadding and cellspacing in table with CSS?

The padding inside a table-divider (TD) is a padding property applied to the cell itself.


td, th {padding:0}

The spacing in-between the table-dividers is a space between cell borders of the TABLE. To make it effective, you have to specify if your table cells borders will 'collapse' or be 'separated'.


table, td, th {border-collapse:separate}
table {border-spacing:6px}

Try this : ( 27 100 results )

Array initialization syntax when not in a declaration

Why is this blocked by Java?

You'd have to ask the Java designers. There might be some subtle grammatical reason for the restriction. Note that some of the array creation / initialization constructs were not in Java 1.0, and (IIRC) were added in Java 1.1.

But "why" is immaterial ... the restriction is there, and you have to live with it.

I know how to work around it, but from time to time it would be simpler.

You can write this:

AClass[] array;
array = new AClass[]{object1, object2};

C# DataTable.Select() - How do I format the filter criteria to include null?

Try out Following:

DataRow rows = DataTable.Select("[Name]<>'n/a'")

For Null check in This:

DataRow rows =  DataTable.Select("[Name] <> 'n/a' OR [Name] is NULL" )

HTML text input field with currency symbol

Consider simulating an input field with a fixed prefix or suffix using a span with a border around a borderless input field. Here's a basic kickoff example:

.currencyinput {_x000D_
    border: 1px inset #ccc;_x000D_
.currencyinput input {_x000D_
    border: 0;_x000D_
<span class="currencyinput">$<input type="text" name="currency"></span>

How to navigate a few folders up?

this may help

string parentOfStartupPath = Path.GetFullPath(Path.Combine(Application.StartupPath, @"../../")) + "Orders.xml";
if (File.Exists(parentOfStartupPath))
    // file found

Removing trailing newline character from fgets() input

size_t ln = strlen(name) - 1;
if (*name && name[ln] == '\n') 
    name[ln] = '\0';

Name [jdbc/mydb] is not bound in this Context

You need a ResourceLink in your META-INF/context.xml file to make the global resource available to the web application.

 <ResourceLink name="jdbc/mydb"
              type="javax.sql.DataSource" />

Vim: faster way to select blocks of text in visual mode

In addition to what others have said, you can also expand your selection using pattern searches.

For example, v/foo will select from your current position to the next instance of "foo." If you actually wanted to expand to the next instance of "foo," on line 35, for example, just press n to expand selection to the next instance, and so on.


I don't often do it, but I know that some people use marks extensively to make visual selections. For example, if I'm on line 5 and I want to select to line 35, I might press ma to place mark a on line 5, then :35 to move to line 35. Shift + v to enter linewise visual mode, and finally `a to select back to mark a.

Get absolute path of initially run script

This is what I use and it works in Linux environments. I don't think this would work on a Windows machine...

//define canonicalized absolute pathname for the script
    //does the script name start with the directory separator?
    //if so, the path is defined from root; may have symbolic references so still use realpath()
    $script = realpath($_SERVER['SCRIPT_NAME']);
} else {
    //otherwise prefix script name with the current working directory
    //and use realpath() to resolve symbolic references
    $script = realpath(getcwd() . DIRECTORY_SEPARATOR . $_SERVER['SCRIPT_NAME']);

How to multi-line "Replace in files..." in Notepad++

This is a subjective opinion, but I think a text editor shouldn't do everything and the kitchen sink. I prefer lightweight flexible and powerful (in their specialized fields) editors. Although being mostly a Windows user, I like the Unix philosophy of having lot of specialized tools that you can pipe together (like the UnxUtils) rather than a monster doing everything, but not necessarily as you would like it!

Find in files is on the border of these extra features, but useful when you can double-click on a found line to open the file at the right line. Note that initially, in SciTE it was just a Tools call to grep or equivalent!
FTP is very close to off topic, although it can be seen as an extended open/save dialog.
Replace in files is too much IMO: it is dangerous (you can mess lot of files at once) if you have no preview, etc. I would rather use a specialized tool I chose, perhaps among those in Multi line search and replace tool.

To answer the question, looking at N++, I see a Run menu where you can launch any tool, with assignment of a name and shortcut key. I see also Plugins > NppExec, which seems able to launch stuff like sed (not tried it).

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

The for-loop will iterate over each (space separated) entry on the provided string.

You do not actually execute the find command, but provide it is as string (which gets iterated by the for-loop). Instead of the double quotes use either backticks or $():

for line in $(find . -iname '*.txt'); do 
     echo "$line"
     ls -l "$line"

Furthermore, if your file paths/names contains spaces this method fails (since the for-loop iterates over space separated entries). Instead it is better to use the method described in dogbanes answer.

To clarify your error:

As said, for line in "find . -iname '*.txt'"; iterates over all space separated entries, which are:

  • find
  • .
  • -iname
  • '*.txt' (I think...)

The first two do not result in an error (besides the undesired behavior), but the third is problematic as it executes:

ls -l -iname

A lot of (bash) commands can combine single character options, so -iname is the same as -i -n -a -m -e. And voila: your invalid option -- 'e' error!

changing the language of error message in required field in html5 contact form

<input type="text" id="inputName"  placeholder="Enter name"  required  oninvalid="this.setCustomValidity('Please Enter your first name')" >

this can help you even more better, Fast, Convenient & Easiest.

Showing alert in angularjs when user leaves a page

As you've discovered above, you can use a combination of window.onbeforeunload and $locationChangeStart to message the user. In addition, you can utilize ngForm.$dirty to only message the user when they have made changes.

I've written an angularjs directive that you can apply to any form that will automatically watch for changes and message the user if they reload the page or navigate away. @see

Hopefully you find this directive useful!

Getting Index of an item in an arraylist;

I think a for-loop should be a valid solution :

    public int getIndexByname(String pName)
        for(AuctionItem _item : *yourArray*)
                return *yourarray*.indexOf(_item)
        return -1;

Synchronously waiting for an async operation, and why does Wait() freeze the program here

Here is what I did

private void myEvent_Handler(object sender, SomeEvent e)
  // I dont know how many times this event will fire
  Task t = new Task(() =>
    if (something == true) 

working great and not blocking UI thread

PHP upload image

 $target_dir = "images/";
    echo $target_file = $target_dir . basename($_FILES["image"]["name"]);
    $post_tmp_img = $_FILES["image"]["tmp_name"];
    $imageFileType = strtolower(pathinfo($target_file, PATHINFO_EXTENSION));
    $post_imag = $_FILES["image"]["name"];

eval command in Bash and its typical uses

I've recently had to use eval to force multiple brace expansions to be evaluated in the order I needed. Bash does multiple brace expansions from left to right, so

xargs -I_ cat _/{11..15}/{8..5}.jpg

expands to

xargs -I_ cat _/11/8.jpg _/11/7.jpg _/11/6.jpg _/11/5.jpg _/12/8.jpg _/12/7.jpg _/12/6.jpg _/12/5.jpg _/13/8.jpg _/13/7.jpg _/13/6.jpg _/13/5.jpg _/14/8.jpg _/14/7.jpg _/14/6.jpg _/14/5.jpg _/15/8.jpg _/15/7.jpg _/15/6.jpg _/15/5.jpg

but I needed the second brace expansion done first, yielding

xargs -I_ cat _/11/8.jpg _/12/8.jpg _/13/8.jpg _/14/8.jpg _/15/8.jpg _/11/7.jpg _/12/7.jpg _/13/7.jpg _/14/7.jpg _/15/7.jpg _/11/6.jpg _/12/6.jpg _/13/6.jpg _/14/6.jpg _/15/6.jpg _/11/5.jpg _/12/5.jpg _/13/5.jpg _/14/5.jpg _/15/5.jpg

The best I could come up with to do that was

xargs -I_ cat $(eval echo _/'{11..15}'/{8..5}.jpg)

This works because the single quotes protect the first set of braces from expansion during the parsing of the eval command line, leaving them to be expanded by the subshell invoked by eval.

There may be some cunning scheme involving nested brace expansions that allows this to happen in one step, but if there is I'm too old and stupid to see it.

What is the difference between ManualResetEvent and AutoResetEvent in .NET?

OK, normally it does not a good practice to add 2 answers in same thread, but I did not want to edit/delete my previous answer, since it can help on another manner.

Now, I created, much more comprehensive, and easy to understand, run-to-learn console app snippet below.

Just run the examples on two different consoles, and observe behaviour. You will get much more clear idea there what is happening behind the scenes.

Manual Reset Event

using System;
using System.Threading;

namespace ConsoleApplicationDotNetBasics.ThreadingExamples
    public class ManualResetEventSample
        private readonly ManualResetEvent _manualReset = new ManualResetEvent(false);

        public void RunAll()
            new Thread(Worker1).Start();
            new Thread(Worker2).Start();
            new Thread(Worker3).Start();
            Console.WriteLine("All Threads Scheduled to RUN!. ThreadId: {0}", Thread.CurrentThread.ManagedThreadId);
            Console.WriteLine("Main Thread is waiting for 15 seconds, observe 3 thread behaviour. All threads run once and stopped. Why? Because they call WaitOne() internally. They will wait until signals arrive, down below.");
            Console.WriteLine("1- Main will call ManualResetEvent.Set() in 5 seconds, watch out!");
            Console.WriteLine("2- Main will call ManualResetEvent.Set() in 5 seconds, watch out!");
            Console.WriteLine("3- Main will call ManualResetEvent.Set() in 5 seconds, watch out!");
            Console.WriteLine("4- Main will call ManualResetEvent.Reset() in 5 seconds, watch out!");
            Console.WriteLine("It ran one more time. Why? Even Reset Sets the state of the event to nonsignaled (false), causing threads to block, this will initial the state, and threads will run again until they WaitOne().");
            Console.WriteLine("This will go so on. Everytime you call Set(), ManualResetEvent will let ALL threads to run. So if you want synchronization between them, consider using AutoReset event, or simply user TPL (Task Parallel Library).");
            Console.WriteLine("Main thread reached to end! ThreadId: {0}", Thread.CurrentThread.ManagedThreadId);


        public void Worker1()
            for (int i = 1; i <= 10; i++)
                Console.WriteLine("Worker1 is running {0}/10. ThreadId: {1}.", i, Thread.CurrentThread.ManagedThreadId);
                // this gets blocked until _autoReset gets signal
            Console.WriteLine("Worker1 is DONE. ThreadId: {0}", Thread.CurrentThread.ManagedThreadId);
        public void Worker2()
            for (int i = 1; i <= 10; i++)
                Console.WriteLine("Worker2 is running {0}/10. ThreadId: {1}.", i, Thread.CurrentThread.ManagedThreadId);
                // this gets blocked until _autoReset gets signal
            Console.WriteLine("Worker2 is DONE. ThreadId: {0}", Thread.CurrentThread.ManagedThreadId);
        public void Worker3()
            for (int i = 1; i <= 10; i++)
                Console.WriteLine("Worker3 is running {0}/10. ThreadId: {1}.", i, Thread.CurrentThread.ManagedThreadId);
                // this gets blocked until _autoReset gets signal
            Console.WriteLine("Worker3 is DONE. ThreadId: {0}", Thread.CurrentThread.ManagedThreadId);


Manual Reset Event Output

Auto Reset Event

using System;
using System.Threading;

namespace ConsoleApplicationDotNetBasics.ThreadingExamples
    public class AutoResetEventSample
        private readonly AutoResetEvent _autoReset = new AutoResetEvent(false);

        public void RunAll()
            new Thread(Worker1).Start();
            new Thread(Worker2).Start();
            new Thread(Worker3).Start();
            Console.WriteLine("All Threads Scheduled to RUN!. ThreadId: {0}", Thread.CurrentThread.ManagedThreadId);
            Console.WriteLine("Main Thread is waiting for 15 seconds, observe 3 thread behaviour. All threads run once and stopped. Why? Because they call WaitOne() internally. They will wait until signals arrive, down below.");
            Console.WriteLine("1- Main will call AutoResetEvent.Set() in 5 seconds, watch out!");
            Console.WriteLine("2- Main will call AutoResetEvent.Set() in 5 seconds, watch out!");
            Console.WriteLine("3- Main will call AutoResetEvent.Set() in 5 seconds, watch out!");
            Console.WriteLine("4- Main will call AutoResetEvent.Reset() in 5 seconds, watch out!");
            Console.WriteLine("Nothing happened. Why? Becasuse Reset Sets the state of the event to nonsignaled, causing threads to block. Since they are already blocked, it will not affect anything.");
            Console.WriteLine("This will go so on. Everytime you call Set(), AutoResetEvent will let another thread to run. It will make it automatically, so you do not need to worry about thread running order, unless you want it manually!");
            Console.WriteLine("Main thread reached to end! ThreadId: {0}", Thread.CurrentThread.ManagedThreadId);


        public void Worker1()
            for (int i = 1; i <= 5; i++)
                Console.WriteLine("Worker1 is running {0}/5. ThreadId: {1}.", i, Thread.CurrentThread.ManagedThreadId);
                // this gets blocked until _autoReset gets signal
            Console.WriteLine("Worker1 is DONE. ThreadId: {0}", Thread.CurrentThread.ManagedThreadId);
        public void Worker2()
            for (int i = 1; i <= 5; i++)
                Console.WriteLine("Worker2 is running {0}/5. ThreadId: {1}.", i, Thread.CurrentThread.ManagedThreadId);
                // this gets blocked until _autoReset gets signal
            Console.WriteLine("Worker2 is DONE. ThreadId: {0}", Thread.CurrentThread.ManagedThreadId);
        public void Worker3()
            for (int i = 1; i <= 5; i++)
                Console.WriteLine("Worker3 is running {0}/5. ThreadId: {1}.", i, Thread.CurrentThread.ManagedThreadId);
                // this gets blocked until _autoReset gets signal
            Console.WriteLine("Worker3 is DONE. ThreadId: {0}", Thread.CurrentThread.ManagedThreadId);


Auto Reset Event Output

Python main call within class

Well, first, you need to actually define a function before you can run it (and it doesn't need to be called main). For instance:

class Example(object):
    def run(self):
        print "Hello, world!"

if __name__ == '__main__':

You don't need to use a class, though - if all you want to do is run some code, just put it inside a function and call the function, or just put it in the if block:

def main():
    print "Hello, world!"

if __name__ == '__main__':


if __name__ == '__main__':
    print "Hello, world!"

How do I decode a string with escaped unicode?

Edit (2017-10-12):

@MechaLynx and @Kevin-Weber note that unescape() is deprecated from non-browser environments and does not exist in TypeScript. decodeURIComponent is a drop-in replacement. For broader compatibility, use the below instead:

> ''

Original answer:

> ''

You can offload all the work to JSON.parse

How to check certificate name and alias in keystore files?

You can run from Java code.

try {

        File file = new File(keystore location);
        InputStream is = new FileInputStream(file);
        KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
        String password = "password";
        keystore.load(is, password.toCharArray());

        Enumeration<String> enumeration = keystore.aliases();
        while(enumeration.hasMoreElements()) {
            String alias = enumeration.nextElement();
            System.out.println("alias name: " + alias);
            Certificate certificate = keystore.getCertificate(alias);


    } catch ( e) {
    } catch (NoSuchAlgorithmException e) {
    } catch (FileNotFoundException e) {
    } catch (KeyStoreException e) {
    } catch (IOException e) {
    }finally {
        if(null != is)
            try {
            } catch (IOException e) {
                // TODO Auto-generated catch block

Certificate class holds all information about the keystore.


Key key = keyStore.getKey(alias, password.toCharArray());
String encodedKey = new Base64Encoder().encode(key.getEncoded());
System.out.println("key ? " + encodedKey);

@prateek Hope this is what you looking for!

When using Trusted_Connection=true and SQL Server authentication, will this affect performance?

If your web application is configured to impersonate a client, then using a trusted connection will potentially have a negative performance impact. This is because each client must use a different connection pool (with the client's credentials).

Most web applications don't use impersonation / delegation, and hence don't have this problem.

See this MSDN article for more information.

How to get store information in Magento?

In Magento and maybe all versions in 1.x use:


and the following params, it depends what you want to get:

  • general/store_information/name
  • general/store_information/phone
  • general/store_information/merchant_country
  • general/store_information/address
  • general/store_information/merchant_vat_number

Convert System.Drawing.Color to RGB and Hex Value

For hexadecimal code try this

  1. Get ARGB (Alpha, Red, Green, Blue) representation for the color
  2. Filter out Alpha channel: & 0x00FFFFFF
  3. Format out the value (as hexadecimal "X6" for hex)

For RGB one

  1. Just format out Red, Green, Blue values


private static string HexConverter(Color c) {
  return String.Format("#{0:X6}", c.ToArgb() & 0x00FFFFFF);

public static string RgbConverter(Color c) {
  return String.Format("RGB({0},{1},{2})", c.R, c.G, c.B);

What does the Java assert keyword do, and when should it be used?

A lot of good answers explaining what the assert keyword does, but few answering the real question, "when should the assert keyword be used in real life?"

The answer: almost never.

Assertions, as a concept, are wonderful. Good code has lots of if (...) throw ... statements (and their relatives like Objects.requireNonNull and Math.addExact). However, certain design decisions have greatly limited the utility of the assert keyword itself.

The driving idea behind the assert keyword is premature optimization, and the main feature is being able to easily turn off all checks. In fact, the assert checks are turned off by default.

However, it is critically important that invariant checks continue to be done in production. This is because perfect test coverage is impossible, and all production code will have bugs which assertions should help to diagnose and mitigate.

Therefore, the use of if (...) throw ... should be preferred, just as it is required for checking parameter values of public methods and for throwing IllegalArgumentException.

Occasionally, one might be tempted to write an invariant check that does take an undesirably long time to process (and is called often enough for it to matter). However, such checks will slow down testing which is also undesirable. Such time-consuming checks are usually written as unit tests. Nevertheless, it may sometimes make sense to use assert for this reason.

Do not use assert simply because it is cleaner and prettier than if (...) throw ... (and I say that with great pain, because I like clean and pretty). If you just cannot help yourself, and can control how your application is launched, then feel free to use assert but always enable assertions in production. Admittedly, this is what I tend to do. I am pushing for a lombok annotation that will cause assert to act more like if (...) throw .... Vote for it here.

(Rant: the JVM devs were a bunch of awful, prematurely optimizing coders. That is why you hear about so many security issues in the Java plugin and JVM. They refused to include basic checks and assertions in production code, and we are continuing to pay the price.)

How can I load storyboard programmatically from class?

The extension below will allow you to load a Storyboard and it's associated UIViewController. Example: If you have a UIViewController named ModalAlertViewController and a storyboard named "ModalAlert" e.g.

let vc: ModalAlertViewController = UIViewController.loadStoryboard("ModalAlert")

Will load both the Storyboard and UIViewController and vc will be of type ModalAlertViewController. Note Assumes that the storyboard's Storyboard ID has the same name as the storyboard and that the storyboard has been marked as Is Initial View Controller.

extension UIViewController {
    /// Loads a `UIViewController` of type `T` with storyboard. Assumes that the storyboards Storyboard ID has the same name as the storyboard and that the storyboard has been marked as Is Initial View Controller.
    /// - Parameter storyboardName: Name of the storyboard without .xib/nib suffix.
    static func loadStoryboard<T: UIViewController>(_ storyboardName: String) -> T? {
        let storyboard = UIStoryboard(name: storyboardName, bundle: nil)
        if let vc = storyboard.instantiateViewController(withIdentifier: storyboardName) as? T {
            vc.loadViewIfNeeded() // ensures vc.view is loaded before returning
            return vc
        return nil

base_url() function not working in codeigniter

Question -I wanted to load my css file but it was not working even though i autoload and manual laod why ? i found the solution => here is my solution : application>config>config.php $config['base_url'] = 'http://localhost/CodeIgniter/'; //paste the link to base url

question explanation:

" > i had my bootstrap.min.css file inside assets/css folder where assets is root directory which i was created.But it was not working even though when i loaded ? 1. $autoload['helper'] = array('url'); 2. $this->load->helper('url'); in my controllar then i go to my

Unable instantiate android.gms.maps.MapFragment

In IntelliJ IDEA (updated for IntelliJ 12):

  1. Create a file ~/android-sdk/extras/google/google_play_services/libproject/google-play-services_lib/src/ containing class dummy {}.
  2. File->Import Module-> ~/android-sdk/extras/google/google_play_services/libproject/google-play-services_lib
  3. Create Module from Existing Sources
  4. Next->Next->Next->Next->Finish
  5. File->Project Structure->Modules->YourApp
  6. +->Module Dependency->Google-play-services_lib (The + button is in the top right corner of the dialog.)
  7. +->Jars or directories->~/android-sdk/extras/google/google_play_services/libproject/google-play-services_lib/libs/google-play-services.jar
  8. Use the up/down arrows to move <Module source> to the bottom of the list.

You can delete if you like.

Edit: After using this for a while I've found that there is a small flaw/bug. IDEA will sometimes complain about not being able to open a .iml project file in the google-play-services_lib directory, despite the fact that you never told it there was a project there. If that happens, rebuilding the project solves the problem, at least until it comes back.

ModalPopupExtender OK Button click event not firing?

I often use a blank label as the TargetControlID. ex. <asp:Label ID="lblghost" runat="server" Text="" />

I've seen two things that cause the click event not fire:
1. you have to remove the OKControlID (as others have mentioned)
2. If you are using field validators you should add CausesValidation="false" on the button.

Both scenarios behaved the same way for me.

Disable Copy or Paste action for text box?

Here is the updated fiddle.

    $('#confirmEmail').bind("cut copy paste",function(e) {

This will prevent cut copy paste on Confirm Email text box.

Hope it helps.

How to insert values in table with foreign key using MySQL?

Case 1

INSERT INTO tab_student (name_student, id_teacher_fk)
    VALUES ('dan red', 
           (SELECT id_teacher FROM tab_teacher WHERE name_teacher ='jason bourne')

it is advisable to store your values in lowercase to make retrieval easier and less error prone

Case 2

mysql docs

INSERT INTO tab_teacher (name_teacher) 
    VALUES ('tom stills')
INSERT INTO tab_student (name_student, id_teacher_fk)
    VALUES ('rich man', LAST_INSERT_ID())

How to read a file from jar in Java?

A JAR is basically a ZIP file so treat it as such. Below contains an example on how to extract one file from a WAR file (also treat it as a ZIP file) and outputs the string contents. For binary you'll need to modify the extraction process, but there are plenty of examples out there for that.

public static void main(String args[]) {
    String relativeFilePath = "style/someCSSFile.css";
    String zipFilePath = "/someDirectory/someWarFile.war";
    String contents = readZipFile(zipFilePath,relativeFilePath);

public static String readZipFile(String zipFilePath, String relativeFilePath) {
    try {
        ZipFile zipFile = new ZipFile(zipFilePath);
        Enumeration<? extends ZipEntry> e = zipFile.entries();

        while (e.hasMoreElements()) {
            ZipEntry entry = (ZipEntry) e.nextElement();
            // if the entry is not directory and matches relative file then extract it
            if (!entry.isDirectory() && entry.getName().equals(relativeFilePath)) {
                BufferedInputStream bis = new BufferedInputStream(
                // Read the file
                    // With Apache Commons I/O
                 String fileContentsStr = IOUtils.toString(bis, "UTF-8");

                    // With Guava
                //String fileContentsStr = new String(ByteStreams.toByteArray(bis),Charsets.UTF_8);
                // close the input stream.
                return fileContentsStr;
            } else {
    } catch (IOException e) {
        logger.error("IOError :" + e);
    return null;

In this example I'm using Apache Commons I/O and if you are using Maven here is the dependency:


Cannot create SSPI context

Had a really weird instance of this; All the web products that had connection strings containing the windows computer name of the SQL server worked fine, but the products that had a FQDN with the internal domain attached gave an SSPI error. i.e. COMPUTERNAME vs COMPUTERNAME.DOMAIN (ping always worked as expected)

This ONLY gave problems when a new SQL server was being used and hosts files pointed both the computer name and the computername as a FQDN for the connection strings.

Solution in this case was to set all the connection strings to the computer name only, removing the domain references.

SQL : 2008R2 SQL2012

IIS : 2008R2

Image inside div has extra space below the image

I just added float:left to div and it worked

Convert HTML string to image

       <!--ForExport data in iamge -->
        <script type="text/javascript">
            function ConvertToImage(btnExport) {
                html2canvas($("#dvTable")[0]).then(function (canvas) {
                    var base64 = canvas.toDataURL();
                    __doPostBack(, "");
                return false;

        <!--ForExport data in iamge -->

        <script type="text/javascript" src=""></script>
        <script src="../js/html2canvas.min.js"></script> 

                    <td valign="top">
                        <asp:Button ID="btnExport" Text="Download Back" runat="server" UseSubmitBehavior="false"
                            OnClick="ExportToImage" OnClientClick="return ConvertToImage(this)" />
                        <div id="dvTable" class="divsection2" style="width: 350px">
                            <asp:HiddenField ID="hfImageData" runat="server" />
                            <table width="100%">
                                        <br />

                                        <asp:Label ID="Labelgg" runat="server" CssClass="labans4" Text=""></asp:Label>


         protected void ExportToImage(object sender, EventArgs e)
                    string base64 = Request.Form[hfImageData.UniqueID].Split(',')[1];
                    byte[] bytes = Convert.FromBase64String(base64);
                    Response.ContentType = "image/png";
                    Response.AddHeader("Content-Disposition", "attachment; filename=name.png");
                    Response.Buffer = true;


Delete file from internal storage

Have you tried getFilesDir().getAbsolutePath()?

Seems you fixed your problem by initializing the File object with a full path. I believe this would also do the trick.

How to abort an interactive rebase if --abort doesn't work?

Try to follow the advice you see on the screen, and first reset your master's HEAD to the commit it expects.

git update-ref refs/heads/master b918ac16a33881ce00799bea63d9c23bf7022d67

Then, abort the rebase again.

File is universal (three slices), but it does not contain a(n) ARMv7-s slice error for static libraries on iOS, anyway to bypass?

Try to remove armv7s from project's "Valid architecture" to release from this issue for iOS 5.1 phone

How to set session timeout in web.config

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

         <sessionState timeout="20"></sessionState>

Android: Clear the back stack

I found an interesting solution which might help. I did this in my onBackPressed() method.


FinishAffinity removes the connection of the existing activity to its stack. And then finish helps you exit that activity. Which will eventually exit the application.

How to prevent Right Click option using jquery

<body oncontextmenu="return false" onselectstart="return false" ondragstart="return false" >

Set these attributes in your selected tag

See here Working Example -

No Need JQuery (like)

How can javascript upload a blob?

I tried all the solutions above and in addition, those in related answers as well. Solutions including but not limited to passing the blob manually to a HTMLInputElement's file property, calling all the readAs* methods on FileReader, using a File instance as second argument for a FormData.append call, trying to get the blob data as a string by getting the values at URL.createObjectURL(myBlob) which turned out nasty and crashed my machine.

Now, if you happen to attempt those or more and still find you're unable to upload your blob, it could mean the problem is server-side. In my case, my blob exceeded the and post_max_size limit in PHP.INI so the file was leaving the front end form but getting rejected by the server. You could either increase this value directly in PHP.INI or via .htaccess

Angular and debounce

You can create an RxJS (v.6) Observable that does whatever you like.


<input type="text" (input)="onSearchChange($" />


import { Observable } from 'rxjs';
import { debounceTime, distinctUntilChanged } from 'rxjs/operators';

export class ViewComponent {

  onSearchChange(searchValue: string) {

    if (!this.searchChangeObserver) {
      Observable.create(observer => {
        this.searchChangeObserver = observer;
      }).pipe(debounceTime(300)) // wait 300ms after the last event before emitting last event
        .pipe(distinctUntilChanged()) // only emit if value is different from previous value


Javascript (+) sign concatenates instead of giving sum of variables

Joachim Sauer's answer will work in scenarios like this. But there are some instances where adding parentheses won’t help.

For example: You are passing “sum of value of an input element and an integer” as an argument to a function.

arg1 = $("#elemId").val();   // value is treated as string
arg2 = 1;
someFuntion(arg1 + arg2);    // and so the values are merged here
someFuntion((arg1 + arg2));  // and here

You can make it work by using Number()

arg1 = Number($("#elemId").val());
arg2 = 1;
someFuntion(arg1 + arg2);


arg1 = $("#elemId").val();
arg2 = 1;
someFuntion(Number(arg1) + arg2);

How to set TextView textStyle such as bold, italic

AppCompatTextView text =(AppCompatTextView)findViewById(R.layout.appCompatTextView1);

Use above method to set the typeface programmatically.

What's the difference between ViewData and ViewBag?

One main difference I noticed between ViewData and ViewBag is:

ViewData : it will return object does not matter what you have assigned into this and need to typecast again back to the original type.

ViewBag : it is enough smart to return exact type what you have assigned to it it does not matter weather you have assigned simple type (i.e. int, string etc.) or complex type.

Ex: Controller code.

 namespace WebApplication1.Controllers
    public class HomeController : Controller
        public ActionResult Index()
            Products p1 = new Products();
            p1.productId = 101;
            p1.productName = "Phone";
            Products p2 = new Products();
            p2.productId = 102;
            p2.productName = "laptop";

            List<Products> products = new List<Products>();
            ViewBag.Countries = products;
            return View();
    public class Products
        public int productId { get; set; }
        public string productName { get; set; }

View Code.

            @foreach (WebApplication1.Controllers.Products item in ViewBag.Countries)
            <li>@item.productId &nbsp;&nbsp;&nbsp;@item.productName</li>

OutPut Screen.

enter image description here

Get the filePath from Filename using Java

Correct solution with "File" class to get the directory - the "path" of the file:

String path = new File("C:\\Temp\\your directory\\yourfile.txt").getParent();

which will return:

path = "C:\\Temp\\your directory"

PHP Fatal error: Class 'PDO' not found

I had to run the following on AWS EC2 Linux instance (PHP Version 7.3):

sudo yum install php73-php-pdo php73-php-mysqlnd

get all keys set in memcached

The easiest way is to use python-memcached-stats package,

The keys() method should get you going.

Example -

from memcached_stats import MemcachedStats
mem = MemcachedStats()

 ... ]

center MessageBox in parent form

From a comment on Joel Spolsky's blog:

A Messagebox is always centered on the screen. You can provide an owner, but that is just for Z-order, not centering. The only way is to use Win32 hooks and center it yourself. You can find code doing that online if you search for it.

Much easier is to just write your own message box class and add centering functionality. Then you can also add default captioning, Do not show again-checkbox and making them modeless.

"Win32 hooks" probably refers to using SetWindowsHookEx as shown in this example.

Why should text files end with a newline?

Because that’s how the POSIX standard defines a line:

3.206 Line
A sequence of zero or more non- <newline> characters plus a terminating <newline> character.

Therefore, lines not ending in a newline character aren't considered actual lines. That's why some programs have problems processing the last line of a file if it isn't newline terminated.

There's at least one hard advantage to this guideline when working on a terminal emulator: All Unix tools expect this convention and work with it. For instance, when concatenating files with cat, a file terminated by newline will have a different effect than one without:

$ more a.txt
$ more b.txt
bar$ more c.txt
$ cat {a,b,c}.txt

And, as the previous example also demonstrates, when displaying the file on the command line (e.g. via more), a newline-terminated file results in a correct display. An improperly terminated file might be garbled (second line).

For consistency, it’s very helpful to follow this rule – doing otherwise will incur extra work when dealing with the default Unix tools.

Think about it differently: If lines aren’t terminated by newline, making commands such as cat useful is much harder: how do you make a command to concatenate files such that

  1. it puts each file’s start on a new line, which is what you want 95% of the time; but
  2. it allows merging the last and first line of two files, as in the example above between b.txt and c.txt?

Of course this is solvable but you need to make the usage of cat more complex (by adding positional command line arguments, e.g. cat a.txt --no-newline b.txt c.txt), and now the command rather than each individual file controls how it is pasted together with other files. This is almost certainly not convenient.

… Or you need to introduce a special sentinel character to mark a line that is supposed to be continued rather than terminated. Well, now you’re stuck with the same situation as on POSIX, except inverted (line continuation rather than line termination character).

Now, on non POSIX compliant systems (nowadays that’s mostly Windows), the point is moot: files don’t generally end with a newline, and the (informal) definition of a line might for instance be “text that is separated by newlines” (note the emphasis). This is entirely valid. However, for structured data (e.g. programming code) it makes parsing minimally more complicated: it generally means that parsers have to be rewritten. If a parser was originally written with the POSIX definition in mind, then it might be easier to modify the token stream rather than the parser — in other words, add an “artificial newline” token to the end of the input.

Finding CN of users in Active Directory

CN refers to class name, so put in your LDAP query CN=Users. Should work.

What is 0x10 in decimal?

0x means the number is hexadecimal, or base 16.

0x10 is 16.

Visual Studio debugger error: Unable to start program Specified file cannot be found

Guessing from the information I have, you're not actually compiling the program, but trying to run it. That is, ALL_BUILD is set as your startup project. (It should be in a bold font, unlike the other projects in your solution) If you then try to run/debug, you will get the error you describe, because there is simply nothing to run.

The project is most likely generated via CMAKE and included in your Visual Studio solution. Set any of the projects that do generate a .exe as the startup project (by right-clicking on the project and selecting "set as startup project") and you will most likely will be able to start those from within Visual Studio.

VC++ fatal error LNK1168: cannot open filename.exe for writing

This can also be a problem from the improper use of functions like FindNextFile when a FindClose is never executed. The process of the built file is terminated, and the build itself can be deleted, but LNK1168 will prevent a rebuild because of the open handle. This can create a handle leak in Explorer which can be addressed by terminating and restarting Explorer, but in many cases an immediate reboot is necessary.

Get column from a two dimensional array

This function works to arrays and objects. obs: it works like array_column php function. It means that an optional third parameter can be passed to define what column will correspond to the indices of return.

function array_column(list, column, indice){
    var result;

    if(typeof indice != "undefined"){
        result = {};

        for(key in list)
            result[list[key][indice]] = list[key][column];
        result = [];

        for(key in list)
            result.push( list[key][column] );

    return result;

This is a conditional version:

function array_column_conditional(list, column, indice){
    var result;

    if(typeof indice != "undefined"){
        result = {};

        for(key in list)
            if(typeof list[key][column] !== 'undefined' && typeof list[key][indice] !== 'undefined')
                result[list[key][indice]] = list[key][column];
        result = [];

        for(key in list)
            if(typeof list[key][column] !== 'undefined')
                result.push( list[key][column] );

    return result;


var lista = [
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]

var obj_list = [
  {a: 1, b: 2, c: 3},
  {a: 4, b: 5, c: 6},
  {a: 8, c: 9}

var objeto = {
  d: {a: 1, b: 3},
  e: {a: 4, b: 5, c: 6},
  f: {a: 7, b: 8, c: 9}

var list_obj = {
  d: [1, 2, 3],
  e: [4, 5],
  f: [7, 8, 9]

console.log( "column list: ", array_column(lista, 1) );
console.log( "column obj_list: ", array_column(obj_list, 'b', 'c') );
console.log( "column objeto: ", array_column(objeto, 'c') );
console.log( "column list_obj: ", array_column(list_obj, 0, 0) );

console.log( "column list conditional: ", array_column_conditional(lista, 1) );
console.log( "column obj_list conditional: ", array_column_conditional(obj_list, 'b', 'c') );
console.log( "column objeto conditional: ", array_column_conditional(objeto, 'c') );
console.log( "column list_obj conditional: ", array_column_conditional(list_obj, 0, 0) );


column list:  Array [ 2, 5, 8 ]
column obj_list:  Object { 3: 2, 6: 5, 9: undefined }
column objeto:  Array [ undefined, 6, 9 ]
column list_obj:  Object { 1: 1, 4: 4, 7: 7 }

column list conditional:  Array [ 2, 5, 8 ]
column obj_list conditional:  Object { 3: 2, 6: 5 }
column objeto conditional:  Array [ 6, 9 ]
column list_obj conditional:  Object { 1: 1, 4: 4, 7: 7 }

How to scale a BufferedImage

To scale an image, you need to create a new image and draw into it. One way is to use the filter() method of an AffineTransferOp, as suggested here. This allows you to choose the interpolation technique.

private static BufferedImage scale1(BufferedImage before, double scale) {
    int w = before.getWidth();
    int h = before.getHeight();
    // Create a new image of the proper size
    int w2 = (int) (w * scale);
    int h2 = (int) (h * scale);
    BufferedImage after = new BufferedImage(w2, h2, BufferedImage.TYPE_INT_ARGB);
    AffineTransform scaleInstance = AffineTransform.getScaleInstance(scale, scale);
    AffineTransformOp scaleOp 
        = new AffineTransformOp(scaleInstance, AffineTransformOp.TYPE_BILINEAR);

    scaleOp.filter(before, after);
    return after;

Another way is to simply draw the original image into the new image, using a scaling operation to do the scaling. This method is very similar, but it also illustrates how you can draw anything you want in the final image. (I put in a blank line where the two methods start to differ.)

private static BufferedImage scale2(BufferedImage before, double scale) {
    int w = before.getWidth();
    int h = before.getHeight();
    // Create a new image of the proper size
    int w2 = (int) (w * scale);
    int h2 = (int) (h * scale);
    BufferedImage after = new BufferedImage(w2, h2, BufferedImage.TYPE_INT_ARGB);
    AffineTransform scaleInstance = AffineTransform.getScaleInstance(scale, scale);
    AffineTransformOp scaleOp 
        = new AffineTransformOp(scaleInstance, AffineTransformOp.TYPE_BILINEAR);

    Graphics2D g2 = (Graphics2D) after.getGraphics();
    // Here, you may draw anything you want into the new image, but we're
    // drawing a scaled version of the original image.
    g2.drawImage(before, scaleOp, 0, 0);
    return after;

Addendum: Results

To illustrate the differences, I compared the results of the five methods below. Here is what the results look like, scaled both up and down, along with performance data. (Performance varies from one run to the next, so take these numbers only as rough guidelines.) The top image is the original. I scale it double-size and half-size.

As you can see, AffineTransformOp.filter(), used in scaleBilinear(), is faster than the standard drawing method of Graphics2D.drawImage() in scale2(). Also BiCubic interpolation is the slowest, but gives the best results when expanding the image. (For performance, it should only be compared with scaleBilinear() and scaleNearest().) Bilinear seems to be better for shrinking the image, although it's a tough call. And NearestNeighbor is the fastest, with the worst results. Bilinear seems to be the best compromise between speed and quality. The Image.getScaledInstance(), called in the questionable() method, performed very poorly, and returned the same low quality as NearestNeighbor. (Performance numbers are only given for expanding the image.)

enter image description here

public static BufferedImage scaleBilinear(BufferedImage before, double scale) {
    final int interpolation = AffineTransformOp.TYPE_BILINEAR;
    return scale(before, scale, interpolation);

public static BufferedImage scaleBicubic(BufferedImage before, double scale) {
    final int interpolation = AffineTransformOp.TYPE_BICUBIC;
    return scale(before, scale, interpolation);

public static BufferedImage scaleNearest(BufferedImage before, double scale) {
    final int interpolation = AffineTransformOp.TYPE_NEAREST_NEIGHBOR;
    return scale(before, scale, interpolation);

private static 
BufferedImage scale(final BufferedImage before, final double scale, final int type) {
    int w = before.getWidth();
    int h = before.getHeight();
    int w2 = (int) (w * scale);
    int h2 = (int) (h * scale);
    BufferedImage after = new BufferedImage(w2, h2, before.getType());
    AffineTransform scaleInstance = AffineTransform.getScaleInstance(scale, scale);
    AffineTransformOp scaleOp = new AffineTransformOp(scaleInstance, type);
    scaleOp.filter(before, after);
    return after;

 * This is a more generic solution. It produces the same result, but it shows how you 
 * can draw anything you want into the newly created image. It's slower 
 * than scaleBilinear().
 * @param before The original image
 * @param scale The scale factor
 * @return A scaled version of the original image
private static BufferedImage scale2(BufferedImage before, double scale) {
    int w = before.getWidth();
    int h = before.getHeight();
    // Create a new image of the proper size
    int w2 = (int) (w * scale);
    int h2 = (int) (h * scale);
    BufferedImage after = new BufferedImage(w2, h2, before.getType());
    AffineTransform scaleInstance = AffineTransform.getScaleInstance(scale, scale);
    AffineTransformOp scaleOp
            = new AffineTransformOp(scaleInstance, AffineTransformOp.TYPE_BILINEAR);

    Graphics2D g2 = (Graphics2D) after.getGraphics();
    // Here, you may draw anything you want into the new image, but we're just drawing
    // a scaled version of the original image. This is slower than 
    // calling scaleOp.filter().
    g2.drawImage(before, scaleOp, 0, 0);
    return after;

 * I call this one "questionable" because it uses the questionable getScaledImage() 
 * method. This method is no longer favored because it's slow, as my tests confirm.
 * @param before The original image
 * @param scale The scale factor
 * @return The scaled image.
private static Image questionable(final BufferedImage before, double scale) {
    int w2 = (int) (before.getWidth() * scale);
    int h2 = (int) (before.getHeight() * scale);
    return before.getScaledInstance(w2, h2, Image.SCALE_FAST);

How to Lock/Unlock screen programmatically?

Use Activity.getWindow() to get the window of your activity; use Window.addFlags() to add whichever of the following flags in WindowManager.LayoutParams that you desire:

Save current directory in variable using Bash?

I have the following in my .bash_profile:

function mark {
    export $1=`pwd`;

so anytime I want to remember a directory, I can just type, e.g. mark there .

Then when I want to go back to that location, I just type cd $there

java: run a function after a specific number of seconds

Example of using javax.swing.Timer

Timer timer = new Timer(3000, new ActionListener() {
  public void actionPerformed(ActionEvent arg0) {
    // Code to be executed
timer.setRepeats(false); // Only execute once
timer.start(); // Go go go!

This code will only be executed once, and the execution happens in 3000 ms (3 seconds).

As camickr mentions, you should lookup "How to Use Swing Timers" for a short introduction.

How to get UTC time in Python?

import datetime
import pytz

# datetime object with timezone awareness:

# seconds from epoch: 

# ms from epoch:
int( * 1000) 

Remove the last character in a string in T-SQL?

Get the last character

Right(@string, len(@String) - (len(@String) - 1))

jQuery add class .active on menu

window.location.href will give you the current url (as shown in the browser address). After parsing it and retrieving the relevant part you would compare it with each link href and assign the active class to the corresponding link.

Access-Control-Allow-Origin and Angular.js $http

@Swapnil Niwane

I was able to solve this issue by calling an ajax request and formatting the data to 'jsonp'.

          method: 'GET',
          url: url,
          defaultHeaders: {
              'Content-Type': 'application/json',
              "Access-Control-Allow-Origin": "*",
              'Accept': 'application/json'

          dataType: 'jsonp',

          success: function (response) {
            console.log("success ");
          error: function (xhr) {
            console.log("error ");

REST API - Bulk Create or Update in single request

You probably will need to use POST or PATCH, because it is unlikely that a single request that updates and creates multiple resources will be idempotent.

Doing PATCH /docs is definitely a valid option. You might find using the standard patch formats tricky for your particular scenario. Not sure about this.

You could use 200. You could also use 207 - Multi Status

This can be done in a RESTful way. The key, in my opinion, is to have some resource that is designed to accept a set of documents to update/create.

If you use the PATCH method I would think your operation should be atomic. i.e. I wouldn't use the 207 status code and then report successes and failures in the response body. If you use the POST operation then the 207 approach is viable. You will have to design your own response body for communicating which operations succeeded and which failed. I'm not aware of a standardized one.

Detect current device with UI_USER_INTERFACE_IDIOM() in Swift

Swift 4.2 - 5.1 Extension

 public extension UIDevice {

    class var isPhone: Bool {
        return UIDevice.current.userInterfaceIdiom == .phone

    class var isPad: Bool {
        return UIDevice.current.userInterfaceIdiom == .pad

    class var isTV: Bool {
        return UIDevice.current.userInterfaceIdiom == .tv

    class var isCarPlay: Bool {
        return UIDevice.current.userInterfaceIdiom == .carPlay


if UIDevice.isPad {
   // Do something

ORDER BY date and time BEFORE GROUP BY name in mysql

In Oracle, This work for me

SELECT name, min(date), min(time)
    FROM table_name

Checking if a variable is not nil and not zero in ruby

You could initialize discount to 0 as long as your code is guaranteed not to try and use it before it is initialized. That would remove one check I suppose, I can't think of anything else.

My eclipse won't open, i download the bundle pack it keeps saying error log

Make sure you have the prerequisite, a JVM ( installed.

This will be a JRE and JDK package.

There are a number of sources which includes:

Proper use of const for defining functions in JavaScript

There's no problem with what you've done, but you must remember the difference between function declarations and function expressions.

A function declaration, that is:

function doSomething () {}

Is hoisted entirely to the top of the scope (and like let and const they are block scoped as well).

This means that the following will work:

doSomething() // works!
function doSomething() {}

A function expression, that is:

[const | let | var] = function () {} (or () =>

Is the creation of an anonymous function (function () {}) and the creation of a variable, and then the assignment of that anonymous function to that variable.

So the usual rules around variable hoisting within a scope -- block-scoped variables (let and const) do not hoist as undefined to the top of their block scope.

This means:

if (true) {
    doSomething() // will fail
    const doSomething = function () {}

Will fail since doSomething is not defined. (It will throw a ReferenceError)

If you switch to using var you get your hoisting of the variable, but it will be initialized to undefined so that block of code above will still not work. (This will throw a TypeError since doSomething is not a function at the time you call it)

As far as standard practices go, you should always use the proper tool for the job.

Axel Rauschmayer has a great post on scope and hoisting including es6 semantics: Variables and Scoping in ES6

How do I match any character across multiple lines in a regular expression?

we can also use


to match everything including newline without greedy

This will make the new line optional


Spring application context external properties?

You can try something like this:

        location="${}/" />

And define property in your application server / jvm, otherwise the default properties location "classpath:/" (i.e., classes dir of .jar or .war) would be used:

BTW, very useful blog post.

Get JSON data from external URL and display it in a div as plain text

Here is one without using JQuery with pure JavaScript. I used javascript promises and XMLHttpRequest You can try it here on this fiddle


<div id="result" style="color:red"></div>


var getJSON = function(url) {
  return new Promise(function(resolve, reject) {
    var xhr = new XMLHttpRequest();'get', url, true);
    xhr.responseType = 'json';
    xhr.onload = function() {
      var status = xhr.status;
      if (status == 200) {
      } else {

getJSON('').then(function(data) {
    alert('Your Json result is:  ' + data.result); //you can comment this, i used it to debug

    result.innerText = data.result; //display the result in an HTML element
}, function(status) { //error detection....
  alert('Something went wrong.');

How to Make Laravel Eloquent "IN" Query?

Here is how you do in Eloquent

$users = User::whereIn('id', array(1, 2, 3))->get();

And if you are using Query builder then :

$users = DB::table('users')->whereIn('id', array(1, 2, 3))->get();

How to execute Ant build in command line

Try running all targets individually to check that all are running correct

run ant target name to run a target individually

e.g. ant build-project

Also the default target you specified is

project basedir="." default="build" name="iControlSilk4J"

This will only execute build-subprojects,build-project and init

ASP.Net MVC Redirect To A Different View

Here's what you can do:

return View("another view name", anotherviewmodel);

How to write a Python module/package?

Once you have defined your chosen commands, you can simply drag and drop the saved file into the Lib folder in your python program files.

>>> import mymodule 
>>> mymodule.myfunc()

How do I get the current date in JavaScript?

If you're looking for a lot more granular control over the date formats, I thoroughly recommend checking out momentjs. Terrific library - and only 5KB.

Multiple Buttons' OnClickListener() android

You could set the property:


in the xml file for each of those buttons, and use this in the java code:

public void buttonClicked(View view) {

    if (view.getId() == {
        // button1 action
    } else if (view.getId() == {
        //button2 action
    } else if (view.getId() == {
        //button3 action


How to calculate 1st and 3rd quartiles?

Using np.percentile.

q75, q25 = np.percentile(DataFrame, [75,25])
iqr = q75 - q25

Answer from How do you find the IQR in Numpy?

Unable to set data attribute using jQuery Data() API

Happened the same to me. It turns out that

var data = $("#myObject").data();

gives you a non-writable object. I solved it using:

var data = $.extend({}, $("#myObject").data());

And from then on, data was a standard, writable JS object.

Java: How to set Precision for double value?

To set precision for double values DecimalFormat is good technique. To use this class import java.text.DecimalFormat and create object of it for example

double no=12.786;
DecimalFormat dec = new DecimalFormat("#0.00");

So it will print two digits after decimal point here it will print 12.79

How do you loop in a Windows batch file?

Conditionally perform a command several times.

  • syntax-FOR-Files

    FOR %%parameter IN (set) DO command 
  • syntax-FOR-Files-Rooted at Path

    FOR /R [[drive:]path] %%parameter IN (set) DO command 
  • syntax-FOR-Folders

    FOR /D %%parameter IN (folder_set) DO command 
  • syntax-FOR-List of numbers

    FOR /L %%parameter IN (start,step,end) DO command 
  • syntax-FOR-File contents

    FOR /F ["options"] %%parameter IN (filenameset) DO command 


    FOR /F ["options"] %%parameter IN ("Text string to process") DO command
  • syntax-FOR-Command Results

    FOR /F ["options"] %%parameter IN ('command to process') DO command


  • Take a set of data
  • Make a FOR Parameter %%G equal to some part of that data
  • Perform a command (optionally using the parameter as part of the command).
  • --> Repeat for each item of data

If you are using the FOR command at the command line rather than in a batch program, use just one percent sign: %G instead of %%G.

FOR Parameters

  • The first parameter has to be defined using a single character, for example the letter G.

  • FOR %%G IN ...

    In each iteration of a FOR loop, the IN ( ....) clause is evaluated and %%G set to a different value

    If this clause results in a single value then %%G is set equal to that value and the command is performed.

    If the clause results in a multiple values then extra parameters are implicitly defined to hold each. These are automatically assigned in alphabetical order %%H %%I %%J ...(implicit parameter definition)

    If the parameter refers to a file, then enhanced variable reference can be used to extract the filename/path/date/size.

    You can of course pick any letter of the alphabet other than %%G. but it is a good choice because it does not conflict with any of the pathname format letters (a, d, f, n, p, s, t, x) and provides the longest run of non-conflicting letters for use as implicit parameters.

How do function pointers in C work?

Since function pointers are often typed callbacks, you might want to have a look at type safe callbacks. The same applies to entry points, etc of functions that are not callbacks.

C is quite fickle and forgiving at the same time :)

Laravel form html with PUT method for PUT routes

Is very easy, you just need to use method_field('PUT') like this:


<form action="{{ route('route_name') }}" method="post">
    {{ method_field('PUT') }}
    {{ csrf_field() }}


<form action="{{ route('route_name') }}" method="post">
    <input type="hidden" name="_method" value="PUT">
    <input type="hidden" name="_token" value="{{ csrf_token() }}">


Can't change z-index with JQuery

because your jQuery code is wrong. Correctly would be:

var theParent = $(this).parent().get(0); 
$(theParent).css('z-index', 3000);

How to do multiline shell script in Ansible

I prefer this syntax as it allows to set configuration parameters for the shell:

- name: an example
    cmd: |
      docker build -t current_dir .
      echo "Hello World"

    chdir: /home/vagrant/

Adding files to java classpath at runtime

Try this one on for size.

private static void addSoftwareLibrary(File file) throws Exception {
    Method method = URLClassLoader.class.getDeclaredMethod("addURL", new Class[]{URL.class});
    method.invoke(ClassLoader.getSystemClassLoader(), new Object[]{file.toURI().toURL()});

This edits the system class loader to include the given library jar. It is pretty ugly, but it works.

List files ONLY in the current directory

You can use os.listdir for this purpose. If you only want files and not directories, you can filter the results using os.path.isfile.


files = os.listdir(os.curdir)  #files and directories


files = filter(os.path.isfile, os.listdir( os.curdir ) )  # files only
files = [ f for f in os.listdir( os.curdir ) if os.path.isfile(f) ] #list comprehension version.

Scale Image to fill ImageView width and keep aspect ratio

I had a similar issue, I found the reason for this is because you need to calculate the dp. Android studio is calculating the ImageView when you load it from the drawable, but when you are using another method, like loading from bitmap the dp is not automatically accounted for,

Here is my xml

  android:layout_height="match_parent"//dp is not automaticly updated, when loading from a other source
  tools:srcCompat="@drawable/a8" />

I'm using Kotlin, and loading drawable from an asset file, here's how I calculate this

val d = Drawable.createFromStream("imageData/${imageName}.png"), null)
bitHeight = d.minimumHeight//get the image height
imageViewer.layoutParams.height = (bitHeight * resources.displayMetrics.density).toInt()//set the height
imageViewer.setImageDrawable(d)//set the image from the drawable
imageViewer.requestLayout()//here I apply it to the layout

How to prevent XSS with HTML/PHP?

Use htmlspecialchars on PHP. On HTML try to avoid using:

element.innerHTML = “…”; element.outerHTML = “…”; document.write(…); document.writeln(…);

where var is controlled by the user.

Also obviously try avoiding eval(var), if you have to use any of them then try JS escaping them, HTML escape them and you might have to do some more but for the basics this should be enough.

system("pause"); - Why is it wrong?

the pro's to using system("PAUSE"); while creating the small portions of your program is for debugging it yourself. if you use it to get results of variables before during and after each process you are using to assure that they are working properly.

After testing and moving it into full swing with the rest of the solution you should remove these lines. it is really good when testing an user-defined algorithm and assuring that you are doing things in the proper order for results that you want.

In no means do you want to use this in an application after you have tested it and assured that it is working properly. However it does allow you to keep track of everything that is going on as it happens. Don't use it for End-User apps at all.

Pull request vs Merge request

In my point of view, they mean the same activity but from different perspectives:

Think about that, Alice makes some commits on repository A, which was forked from Bob's repository B.

When Alice wants to "merge" her changes into B, she actually wants Bob to "pull" these changes from A.

Therefore, from Alice's point of view, it is a "merge request", while Bob views it as a "pull request".

TCP: can two different sockets share a port?

A connected socket is assigned to a new (dedicated) port

That's a common intuition, but it's incorrect. A connected socket is not assigned to a new/dedicated port. The only actual constraint that the TCP stack must satisfy is that the tuple of (local_address, local_port, remote_address, remote_port) must be unique for each socket connection. Thus the server can have many TCP sockets using the same local port, as long as each of the sockets on the port is connected to a different remote location.

See the "Socket Pair" paragraph at:

What's a Good Javascript Time Picker?

Sorry guys.. maybe it's a bit late.. I've been using NoGray.. it's cool..

getting integer values from textfield

As You're getting values from textfield as jTextField3.getText();.

As it is a textField it will return you string format as its format says:

String getText()

      Returns the text contained in this TextComponent.

So, convert your String to Integer as:

int jml = Integer.parseInt(jTextField3.getText());

instead of directly setting

   int jml = jTextField3.getText();

Excel VBA Run-time Error '32809' - Trying to Understand it

I got this problem after adding a combobox with VBA-code in a particular sheet. Testing the code etc was no problem at all, until I opened the sheet again. Stackoverflow and Microsoft comes with many work arounds, but no real solution. I use excel 2010 (dutch version) with W10 (upgraded from W7). I think the problem is in Excel 2010. In my case, I got an error on the line to unprotect a sheet by VBA, in a module which wasn't changed for a long time.

Ok, this is how it is in my opinion: There was a security issue in FM20.DLL, for whic MS had an update in Q1 2015. This update installs a new FM20.DLL, however the language packages (FM20NLD.DLL and FM20ENU.DLL) were not updated. Possibly, if you don't use a language pack, you don't have this error. In my opinion, the language parts should have been updated as well (but there is no update available)

Ok, deleting the .exd-files works for a moment. This is a temporary work around. MS doesn't has a real solution, but recompiling the code 'solves' the problem.

That is why some people said: 'Add a comment and the problem is solved'. Yes, adding a comment forces a recompilation.

I agree, this is still a work-around, but not a temporary work around. So: 1. check in which part of the VBA-code the error exists 2. add a comment by which a recompile is forced. 3. save the project again

that's all

Java: export to an .jar file in eclipse

No need for external plugins. In the Export JAR dialog, make sure you select all the necessary resources you want to export. By default, there should be no problem exporting other resource files as well (pictures, configuration files, etc...), see screenshot below. JAR Export Dialog

Write to rails console

As other have said, you want to use either puts or p. Why? Is that magic?

Actually not. A rails console is, under the hood, an IRB, so all you can do in IRB you will be able to do in a rails console. Since for printing in an IRB we use puts, we use the same command for printing in a rails console.

You can actually take a look at the console code in the rails source code. See the require of irb? :)

How to get a List<string> collection of values from app.config in WPF?

I love Richard Nienaber's answer, but as Chuu pointed out, it really doesn't tell how to accomplish what Richard is refering to as a solution. Therefore I have chosen to provide you with the way I ended up doing this, ending with the result Richard is talking about.

The solution

In this case I'm creating a greeting widget that needs to know which options it has to greet in. This may be an over-engineered solution to OPs question as I am also creating an container for possible future widgets.

First I set up my collection to handle the different greetings

public class GreetingWidgetCollection : System.Configuration.ConfigurationElementCollection
    public List<IGreeting> All { get { return this.Cast<IGreeting>().ToList(); } }

    public GreetingElement this[int index]
            return base.BaseGet(index) as GreetingElement;
            if (base.BaseGet(index) != null)
            this.BaseAdd(index, value);

    protected override ConfigurationElement CreateNewElement()
        return new GreetingElement();

    protected override object GetElementKey(ConfigurationElement element)
        return ((GreetingElement)element).Greeting;

Then we create the acutal greeting element and it's interface

(You can omit the interface, that's just the way I'm always doing it.)

public interface IGreeting
    string Greeting { get; set; }

public class GreetingElement : System.Configuration.ConfigurationElement, IGreeting
    [ConfigurationProperty("greeting", IsRequired = true)]
    public string Greeting
        get { return (string)this["greeting"]; }
        set { this["greeting"] = value; }

The greetingWidget property so our config understands the collection

We define our collection GreetingWidgetCollection as the ConfigurationProperty greetingWidget so that we can use "greetingWidget" as our container in the resulting XML.

public class Widgets : System.Configuration.ConfigurationSection
    public static Widgets Widget => ConfigurationManager.GetSection("widgets") as Widgets;

    [ConfigurationProperty("greetingWidget", IsRequired = true)]
    public GreetingWidgetCollection GreetingWidget
        get { return (GreetingWidgetCollection) this["greetingWidget"]; }
        set { this["greetingWidget"] = value; }

The resulting XML

<?xml version="1.0" encoding="utf-8" ?>
           <add greeting="Hej" />
           <add greeting="Goddag" />
           <add greeting="Hello" />
           <add greeting="Konnichiwa" />
           <add greeting="Namaskaar" />

And you would call it like this

List<GreetingElement> greetings = Widgets.GreetingWidget.All;

Disabling Log4J Output in Java


change html input type by JS?

Yes, you can even change it by triggering an event

<input type='text' name='pass'  onclick="(this.type='password')" />

<input type="text" placeholder="date" onfocusin="(this.type='date')" onfocusout="(this.type='text')">

android image button

You can use the button :

1 - make the text empty

2 - set the background for it

+3 - you can use the selector to more useful and nice button

About the imagebutton you can set the image source and the background the same picture and it must be (*.png) when you do it you can make any design for the button

and for more beauty button use the selector //just Google it ;)

What's the difference between "2*2" and "2**2" in Python?

  2**2 means 2 squared (2^2)
  2*2 mean 2 times 2 (2x2)

In this case they happen to have the same value, but...

  3**3*4 != 3*3*4

Not able to start Genymotion device

This worked for me..

Open Virtual Box and select your mobile VM. Right click->Settings

Change Promiscuous mode to Allow VMS and click ok

The application may be doing too much work on its main thread

Another common cause of delays on UI thread is SharedPreferences access. When you call a PreferenceManager.getSharedPreferences and other similar methods for the first time, the associated .xml file is immediately loaded and parsed in the same thread.

One of good ways to combat this issue is triggering first SharedPreference load from the background thread, started as early as possible (e.g. from onCreate of your Application class). This way the preference object may be already constructed by the time you'd want to use it.

Unfortunately, sometimes reading a preference files is necessary during early phases of startup (e.g. in the initial Activity or even Application itself). In such cases it is still possible to avoid stalling UI by using MessageQueue.IdleHandler. Do everything else you need to perform on the main thread, then install the IdleHandler to execute code once your Activity have been fully drawn. In that Runnable you should be able to access SharedPreferences without delaying too many drawing operations and making Choreographer unhappy.

Setting PATH environment variable in OSX permanently

You could also add this

if [ -f ~/.bashrc ]; then
    . ~/.bashrc

to ~/.bash_profile, then create ~/.bashrc where you can just add more paths to PATH. An example with .

export PATH=$PATH:.

How to disable all <input > inside a form with jQuery?

The definitive answer (covering changes to jQuery api at version 1.6) has been given by Gnarf

Java parsing XML document gives "Content not allowed in prolog." error

Please check the xml file whether it has any junk character like this ?.If exists,please use the following syntax to remove that.

String XString = writer.toString();
XString = XString.replaceAll("[^\\x20-\\x7e]", "");

How to convert list to string

By using ''.join

list1 = ['1', '2', '3']
str1 = ''.join(list1)

Or if the list is of integers, convert the elements before joining them.

list1 = [1, 2, 3]
str1 = ''.join(str(e) for e in list1)

What is the best project structure for a Python application?

According to Jean-Paul Calderone's Filesystem structure of a Python project:

|-- bin/
|   |-- project
|-- project/
|   |-- test/
|   |   |--
|   |   |--
|   |   
|   |--
|   |--

XML Carriage return encoding

A browser isn't going to show you white space reliably. I recommend the Linux 'od' command to see what's really in there. Comforming XML parsers will respect all of the methods you listed.

How to clear a textbox once a button is clicked in WPF?

You can use Any of the statement given below to clear the text of the text box on button click:

  1. textBoxName.Text = string.Empty;
  2. textBoxName.Clear();
  3. textBoxName.Text = "";

How to resolve git's "not something we can merge" error

The below method works for me every time.

git checkout master
git pull
git checkout branch-name-to-be-merged
git pull
git checkout branch-name
git pull
git merge branch-name-to-be-merged

An implementation of the fast Fourier transform (FFT) in C#

An old question but it still shows up in Google results...

A very un-restrictive MIT Licensed C# / .NET library can be found at,

This library is fast as it parallel threads on multiple cores and is very complete and ready to use.

what does mysql_real_escape_string() really do?

The function adds an escape character, the backslash, \, before certain potentially dangerous characters in a string passed in to the function. The characters escaped are

\x00, \n, \r, \, ', " and \x1a.

This can help prevent SQL injection attacks which are often performed by using the ' character to append malicious code to an SQL query.