Programs & Examples On #Android controls

How to do a case sensitive search in WHERE clause (I'm using SQL Server)?

Just as others said, you can perform a case sensitive search. Or just change the collation format of a specified column as me. For the User/Password columns in my database I change them to collation through the following command:

ALTER TABLE `UserAuthentication` CHANGE `Password` `Password` VARCHAR(255) CHARACTER SET latin1 COLLATE latin1_general_cs NOT NULL;

Create a button with rounded border

          onPressed: null,
          child: Text('Button', style: TextStyle(
          textColor: MyColor.white,
          shape: RoundedRectangleBorder(side: BorderSide(
            width: 1,
            style: BorderStyle.solid
          ), borderRadius: BorderRadius.circular(50)),

Double value to round up in Java

This is not possible in the requested way because there are numbers with two decimal places which can not be expressed exactly using IEEE floating point numbers (for example 1/10 = 0.1 can not be expressed as a Double or Float). The formatting should always happen as the last step before presenting the result to the user.

I guess you are asking because you want to deal with monetary values. There is no way to do this reliably with floating-point numbers, you shoud consider switching to fixed-point arithmetics. This probably means doing all calculations in "cents" instead of "dollars".

Get fragment (value after hash '#') from a URL in php

I've been searching for a workaround for this for a bit - and the only thing I have found is to use URL rewrites to read the "anchor". I found in the apache docs here the following...

By default, redirecting to an HTML anchor doesn't work, because mod_rewrite escapes the # character, turning it into %23. This, in turn, breaks the redirection.

Solution: Use the [NE] flag on the RewriteRule. NE stands for No Escape.

Discussion: This technique will of course also work with other special characters that mod_rewrite, by default, URL-encodes.

It may have other caveats and what not ... but I think that at least doing something with the # on the server is possible.

Android: Clear Activity Stack

Here is a simple helper method for starting a new activity as the new top activity which works from API level 4 up until the current version 17:

static void startNewMainActivity(Activity currentActivity, Class<? extends Activity> newTopActivityClass) {
    Intent intent = new Intent(currentActivity, newTopActivityClass);
        intent.addFlags(0x8000); // equal to Intent.FLAG_ACTIVITY_CLEAR_TASK which is only available from API level 11

call it like this from your current activity:

startNewMainActivity(this, MainActivity.class);

How to Get the Query Executed in Laravel 5? DB::getQueryLog() Returning Empty Array

In continuing of the Apparently with Laravel 5.2, the closure in DB::listen only receives a single parameter... response above : you can put this code into the Middleware script and use it in the routes.


use Monolog\Logger;
use Monolog\Handler\StreamHandler;

$log = new Logger('sql');
$log->pushHandler(new StreamHandler(storage_path().'/logs/sql-' . date('Y-m-d') . '.log', Logger::INFO));

// add records to the log
$log->addInfo($query, $data);

Total memory used by Python process?

Here is a useful solution that works for various operating systems, including Linux, Windows, etc.:

import os, psutil
process = psutil.Process(os.getpid())
print(process.memory_info().rss)  # in bytes 

With Python 2.7 and psutil 5.6.3, the last line should be


instead (there was a change in the API later).


  • do pip install psutil if it is not installed yet

  • handy one-liner if you quickly want to know how many MB your process takes:

    import os, psutil; print(psutil.Process(os.getpid()).memory_info().rss / 1024 ** 2)

Comparison of full text search engine - Lucene, Sphinx, Postgresql, MySQL?

I am surprised that there isn't more information posted about Solr. Solr is quite similar to Sphinx but has more advanced features (AFAIK as I haven't used Sphinx -- only read about it).

The answer at the link below details a few things about Sphinx which also applies to Solr. Comparison of full text search engine - Lucene, Sphinx, Postgresql, MySQL?

Solr also provides the following additional features:

  1. Supports replication
  2. Multiple cores (think of these as separate databases with their own configuration and own indexes)
  3. Boolean searches
  4. Highlighting of keywords (fairly easy to do in application code if you have regex-fu; however, why not let a specialized tool do a better job for you)
  5. Update index via XML or delimited file
  6. Communicate with the search server via HTTP (it can even return Json, Native PHP/Ruby/Python)
  7. PDF, Word document indexing
  8. Dynamic fields
  9. Facets
  10. Aggregate fields
  11. Stop words, synonyms, etc.
  12. More Like this...
  13. Index directly from the database with custom queries
  14. Auto-suggest
  15. Cache Autowarming
  16. Fast indexing (compare to MySQL full-text search indexing times) -- Lucene uses a binary inverted index format.
  17. Boosting (custom rules for increasing relevance of a particular keyword or phrase, etc.)
  18. Fielded searches (if a search user knows the field he/she wants to search, they narrow down their search by typing the field, then the value, and ONLY that field is searched rather than everything -- much better user experience)

BTW, there are tons more features; however, I've listed just the features that I have actually used in production. BTW, out of the box, MySQL supports #1, #3, and #11 (limited) on the list above. For the features you are looking for, a relational database isn't going to cut it. I'd eliminate those straight away.

Also, another benefit is that Solr (well, Lucene actually) is a document database (e.g. NoSQL) so many of the benefits of any other document database can be realized with Solr. In other words, you can use it for more than just search (i.e. Performance). Get creative with it :)

NameError: global name 'unicode' is not defined - in Python 3

One can replace unicode with u''.__class__ to handle the missing unicode class in Python 3. For both Python 2 and 3, you can use the construct

isinstance(unicode_or_str, u''.__class__)


type(unicode_or_str) == type(u'')

Depending on your further processing, consider the different outcome:

Python 3

>>> isinstance('text', u''.__class__)
>>> isinstance(u'text', u''.__class__)

Python 2

>>> isinstance(u'text', u''.__class__)
>>> isinstance('text', u''.__class__)

Send message to specific client with and node.js

Also you can keep clients refferences. But this makes your memmory busy.

Create an empty object and set your clients into it.

const myClientList = {};

  server.on("connection", (socket) => {`Client connected [id=${}]`);
     myClientList[] = socket;   
  socket.on("disconnect", (socket) => {
    delete myClientList[];

then call your specific client by id from the object


Base 64 encode and decode example code

To encrypt:

byte[] encrpt= text.getBytes("UTF-8");
String base64 = Base64.encodeToString(encrpt, Base64.DEFAULT);

To decrypt:

byte[] decrypt= Base64.decode(base64, Base64.DEFAULT);
String text = new String(decrypt, "UTF-8");

UICollectionView - dynamic cell height?

I followed the steps mentioned in this SO and everything is fine except when my Collection View has less data (text) to make it wide enough. Checking the documentation in systemLyaoutSizeFittingSize, I have this solution so my cell take up the width as I requested:

- (CGSize)calculateSizeForSizingCell:(UICollectionViewCell *)sizingCell width:(CGFloat)width {
    CGRect frame = sizingCell.frame;
    frame.size.width = width;
    sizingCell.frame = frame;
    [sizingCell setNeedsLayout];
    [sizingCell layoutIfNeeded];

    CGSize size = [sizingCell systemLayoutSizeFittingSize:UILayoutFittingCompressedSize
    return size;

Hope this would help someone.

- (CGSize)systemLayoutSizeFittingSize:(CGSize)targetSize NS_AVAILABLE_IOS(6_0);

Apple doc:

Equivalent to sending -systemLayoutSizeFittingSize:withHorizontalFittingPriority:verticalFittingPriority: with UILayoutPriorityFittingSizeLevel for both priorities.

While the default value is "pretty low" according to Apple's doc:

When you send -[UIView systemLayoutSizeFittingSize:], the size fitting most closely to the target size (the argument) is computed. UILayoutPriorityFittingSizeLevel is the priority level with which the view wants to conform to the target size in that computation. It's quite low. It is generally not appropriate to make a constraint at exactly this priority. You want to be higher or lower.

So my change of default behavior is to enforce the width (horizontal fitting) with UILayoutPriorityRequired.

How can I get the sha1 hash of a string in node.js?

Obligatory: SHA1 is broken, you can compute SHA1 collisions for 45,000 USD. You should use sha256:

var getSHA256ofJSON = function(input){
    return crypto.createHash('sha256').update(JSON.stringify(input)).digest('hex')

To answer your question and make a SHA1 hash:

var getInsecureSHA1ofJSON = function(input){
    return crypto.createHash(INSECURE_ALGORITHM).update(JSON.stringify(input)).digest('hex')







Official node docs on crypto.createHash()

Opening a remote machine's Windows C drive

If it's not the Home edition of XP, you can use \\servername\c$

Mark Brackett's comment:

Note that you need to be an Administrator on the local machine, as the share permissions are locked down

mongodb how to get max value from collections

what about using aggregate framework:

db.collection.aggregate({ $group : { _id: null, max: { $max : "$age" }}});

Pushing from local repository to GitHub hosted remote

Subversion implicitly has the remote repository associated with it at all times. Git, on the other hand, allows many "remotes", each of which represents a single remote place you can push to or pull from.

You need to add a remote for the GitHub repository to your local repository, then use git push ${remote} or git pull ${remote} to push and pull respectively - or the GUI equivalents.

Pro Git discusses remotes here:

The GitHub help also discusses them in a more "task-focused" way here:

Once you have associated the two you will be able to push or pull branches.

How can I tail a log file in Python?

Python is "batteries included" - it has a nice solution for it:

Reads log file lines that have not been read. Remembers where it finished last time, and continues from there.

import sys
from pygtail import Pygtail

for line in Pygtail("some.log"):

How can I add a custom HTTP header to ajax request with js or jQuery?

Assuming that you mean "When using ajax" and "An HTTP Request header", then use the headers property in the object you pass to ajax()

headers(added 1.5)

Default: {}

A map of additional header key/value pairs to send along with the request. This setting is set before the beforeSend function is called; therefore, any values in the headers setting can be overwritten from within the beforeSend function.

JSON.stringify output to div in pretty print way

A lot of people create very strange responses to these questions that make alot more work than necessary.

The easiest way to do this consists of the following

  1. Parse JSON String using JSON.parse(value)
  2. Stringify Parsed string into a nice format - JSON.stringify(input,undefined,2)
  3. Set output to the value of step 2.

In actual code, an example will be (combining all steps together):

    var input = document.getElementById("input").value;
    document.getElementById("output").value = JSON.stringify(JSON.parse(input),undefined,2);

output.value is going to be the area where you will want to display a beautified JSON.

"Invalid form control" only in Google Chrome

$("...").attr("required"); and $("...").removeAttr("required"); 

didn't work for me until I putted all my jQuery code between that:

$(document).ready(function() {
    //jQuery code goes here

Eclipse error "Could not find or load main class"

I also had the same issue and was getting "Error: Could not find or load main class ...."

I solved it as follows:

  1. Right clicked on my Java main class > Run As > Run Configurations.

  2. In the resultant popup box and Under Java Application your java file name would be selected mode... if not select it

  3. On the right side of the same box and under Classpath tab Clear all Bootstrap and User Entries (if any)
  4. Under Bootstrap Entries Click Advanced Button > Select Add Library Radio and click OK. In next "Add Library" box Select JRE System Library and provide your correct JRE location and click Finish. (If it is not visible then u have to add it by clicking Installed JRE > Add button). Now you can see JRE System Library under BootStrap Entries

  5. Next User Entries > Click Add Projects Button > And then under Project Selection box check on your Project name > OK

The main java file should now work. Hope this may help someone who would be facing similar issues.

Jenkins Git Plugin: How to build specific tag?

If you are using Jenkins pipelines and want to checkout a specific tag (eg: a TAG parameter of your build), here is what you can do:

stage('Checkout') {
  steps {
    checkout scm: [$class: 'GitSCM', userRemoteConfigs: [[url: 'YOUR_GIT_REPO_URL.git', credentialsId: 'YOUR_GIT_CREDENTIALS_ID' ]], branches: [[name: 'refs/tags/${TAG}']]], poll: false

Using 'starts with' selector on individual class names

While the top answer here is a workaround for the asker's particular case, if you're looking for a solution to actually using 'starts with' on individual class names:

You can use this custom jQuery selector, which I call :acp() for "A Class Prefix." Code is at the bottom of this post.

var test = $('div:acp("starting_text")');

This will select any and all <div> elements that have at least one class name beginning with the given string ("starting_text" in this example), regardless of whether that class is at the beginning or elsewhere in the class attribute strings.

<div id="1" class="apple orange lemon" />
<div id="2" class="orange applelemon banana" />
<div id="3" class="orange lemon apple" />
<div id="4" class="lemon orangeapple" />
<div id="5" class="lemon orange" />

var startsWithapp = $('div:acp("app")');

This will return elements 1, 2, and 3, but not 4 or 5.

Here's the declaration for the :acp custom selector, which you can put anywhere:

    $.expr[":"].acp = function(elem, index, m){
          var regString = '\\b' + m[3];
          var reg = new RegExp(regString, "g");
          return elem.className.match(reg);

I made this because I do a lot of GreaseMonkey hacking of websites on which I have no backend control, so I often need to find elements with class names that have dynamic suffixes. It's been very useful.

How to resolve "local edit, incoming delete upon update" message

If you haven't made any changes inside the conflicted directory, you can also rm -rf conflicts_in_here/ and then svn up. This worked for me at least.

Failed to find 'ANDROID_HOME' environment variable

April 11, 2019

None of the answers above solved my problem so I wanted to include a current solution (as of April 2019) for people using Ubuntu 18.04. This is how I solved the question above...

  1. I installed the Android SDK from the website, and put it in this folder: /usr/lib/Android/
  2. Search for where the SDK is installed and the version. In my case it was here:


    Note: that I am using version 28.0.3, your version may differ.

  3. Add ANDROID_HOME to the environment path. To do this, open /etc/environment with a text editor:

    sudo nano /etc/environment

    Add a line for ANDROID_HOME for your specific version and path. In my case it was:


  4. Finally, source the updated environment with: source /etc/environment

    Confirm this by trying: echo $ANDROID_HOME in the terminal. You should get the path of your newly created variable.

    One additionally note about sourcing, I did have to restart my computer for the VScode terminal to recognize my changes. After the restart, the environment was set and I haven't had any issues since.

How to select rows with no matching entry in another table?

You can do something like this

   SELECT IFNULL(`price`.`fPrice`,100) as fPrice,product.ProductId,ProductName 
          FROM `products` left join `price` ON 
          price.ProductId=product.ProductId AND (GeoFancingId=1 OR GeoFancingId 
          IS NULL) WHERE Status="Active" AND Delete="No"

Difference between JE/JNE and JZ/JNZ

From the Intel's manual - Instruction Set Reference, the JE and JZ have the same opcode (74 for rel8 / 0F 84 for rel 16/32) also JNE and JNZ (75 for rel8 / 0F 85 for rel 16/32) share opcodes.

JE and JZ they both check for the ZF (or zero flag), although the manual differs slightly in the descriptions of the first JE rel8 and JZ rel8 ZF usage, but basically they are the same.

Here is an extract from the manual's pages 464, 465 and 467.

 Op Code    | mnemonic  | Description
 74 cb      | JE rel8   | Jump short if equal (ZF=1).
 74 cb      | JZ rel8   | Jump short if zero (ZF ? 1).

 0F 84 cw   | JE rel16  | Jump near if equal (ZF=1). Not supported in 64-bit mode.
 0F 84 cw   | JZ rel16  | Jump near if 0 (ZF=1). Not supported in 64-bit mode.

 0F 84 cd   | JE rel32  | Jump near if equal (ZF=1).
 0F 84 cd   | JZ rel32  | Jump near if 0 (ZF=1).

 75 cb      | JNE rel8  | Jump short if not equal (ZF=0).
 75 cb      | JNZ rel8  | Jump short if not zero (ZF=0).

 0F 85 cd   | JNE rel32 | Jump near if not equal (ZF=0).
 0F 85 cd   | JNZ rel32 | Jump near if not zero (ZF=0).

@Html.DisplayFor - DateFormat ("mm/dd/yyyy")

I have been using this change in my code :

old code :

  @Html.DisplayFor(modelItem => item.dataakt)

new :


Change navbar color in Twitter Bootstrap

Update 2020

Changing the Navbar color is different (and a little easier) in Bootstrap 4. You can create a custom navbar class, and then reference it to change the navbar without impacting other Bootstrap navs..

<nav class="navbar navbar-custom">...</nav>

Bootstrap 4.3+

The CSS required to change the Navbar is much less in Bootstrap 4...

.navbar-custom {
    background-color: #ff5500;
/* change the brand and text color */
.navbar-custom .navbar-brand,
.navbar-custom .navbar-text {
    color: rgba(255,255,255,.8);
/* change the link color */
.navbar-custom .navbar-nav .nav-link {
    color: rgba(255,255,255,.5);
/* change the color of active or hovered links */
.navbar-custom .nav-link,
.navbar-custom .nav-item:hover .nav-link {
    color: #ffffff;

Bootstrap 4 Custom Navbar Demoenter image description here

Changing the active/hover link background color also works with the same CSS, but you must adjust the padding if you want the bg color to fill the full height of the link...

py-0 to remove vertical padding from the entire navbar...

<nav class="navbar navbar-expand-sm navbar-custom py-0">..</nav>

/* change the link color and padding  */
.navbar-custom .navbar-nav .nav-link {
    color: rgba(255,255,255,.5);
    padding: .75rem 1rem;

/* change the color and background color of active links */
.navbar-custom .nav-link,
.navbar-custom .nav-item:hover .nav-link {
    color: #ffffff;
    background-color: #333;

Bootstrap 4 Change Link and Background Color Demo

Also see: Bootstrap 4 Change Hamburger Toggler Color

**Bootstrap 3**
<nav class="navbar navbar-custom">
  <div class="navbar-header">
    <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">...
    <a class="navbar-brand" href="#">Title</a>

.navbar-custom {
.navbar-custom .navbar-nav > li > a {

.navbar-custom .navbar-nav > .active > a {
    color: #ffffff;
.navbar-custom .navbar-nav > li > a:hover,
.navbar-custom .navbar-nav > li > a:focus,
.navbar-custom .navbar-nav > .active > a:hover,
.navbar-custom .navbar-nav > .active > a:focus,
.navbar-custom .navbar-nav > .open >a {
    text-decoration: none;
    background-color: #33aa33;
.navbar-custom .navbar-brand {
.navbar-custom .navbar-toggle {
.navbar-custom .icon-bar {

Custom Navbar Demo on Bootply

If the Navbar has dropdowns, add the following to change dropdown color(s):

/* for dropdowns only */
.navbar-custom .navbar-nav .dropdown-menu  { 
  background-color: #33aa33;
.navbar-custom .navbar-nav .dropdown-menu>li>a  { 
  color: #fff;
.navbar-custom .navbar-nav .dropdown-menu>li>a:hover,.navbar-custom .navbar-nav .dropdown-menu>li>a:focus  { 
  color: #33aa33;

Demo with Dropdown

If you want to change the theme colors all together (beyond the navbar), see this answer

How to set JAVA_HOME for multiple Tomcat instances?

Linux based Tomcat6 should have /etc/tomcat6/tomcat6.conf

# System-wide configuration file for tomcat6 services
# This will be sourced by tomcat6 and any secondary service
# Values will be overridden by service-specific configuration
# files in /etc/sysconfig
# Use this one to change default values for all services
# Change the service specific ones to affect only one service
# (see, for instance, /etc/sysconfig/tomcat6)

# Where your java installation lives

# Where your tomcat installation lives

How to get difference between two dates in Year/Month/Week/Day?

Leap years and uneven months actually make this a non-trivial problem. I'm sure someone can come up with a more efficient way, but here's one option - approximate on the small side first and adjust up (untested):

public static void GetDifference(DateTime date1, DateTime date2, out int Years, 
    out int Months, out int Weeks, out int Days)
    //assumes date2 is the bigger date for simplicity

    TimeSpan diff = date2 - date1;
    Years = diff.Days / 366;
    DateTime workingDate = date1.AddYears(Years);

    while(workingDate.AddYears(1) <= date2)
        workingDate = workingDate.AddYears(1);

    diff = date2 - workingDate;
    Months = diff.Days / 31;
    workingDate = workingDate.AddMonths(Months);

    while(workingDate.AddMonths(1) <= date2)
        workingDate = workingDate.AddMonths(1);

    //weeks and days
    diff = date2 - workingDate;
    Weeks = diff.Days / 7; //weeks always have 7 days
    Days = diff.Days % 7;

Python 3: UnboundLocalError: local variable referenced before assignment

I don't like this behavior, but this is how Python works. The question has already been answered by others, but for completeness, let me point out that Python 2 has more such quirks.

def f(x):
    return x

def main():
    print f(3)
    if (True):
        print [f for f in [1, 2, 3]]


Python 2.7.6 returns an error:

Traceback (most recent call last):
  File "", line 9, in <module>
  File "", line 5, in main
    print f(3)
UnboundLocalError: local variable 'f' referenced before assignment

Python sees the f is used as a local variable in [f for f in [1, 2, 3]], and decides that it is also a local variable in f(3). You could add a global f statement:

def f(x):
    return x

def main():
    global f
    print f(3)
    if (True):
        print [f for f in [1, 2, 3]]


It does work; however, f becomes 3 at the end... That is, print [f for f in [1, 2, 3]] now changes the global variable f to 3, so it is not a function any more.

Fortunately, it works fine in Python3 after adding the parentheses to print.

Run a Python script from another Python script, passing in arguments

I think the good practice may be something like this;

import subprocess
cmd = 'python'

p = subprocess.Popen(cmd, stdout=subprocess.PIPE, shell=True)
out, err = p.communicate() 
result = out.split('\n')
for lin in result:
    if not lin.startswith('#'):

according to documentation The subprocess module allows you to spawn new processes, connect to their input/output/error pipes, and obtain their return codes. This module intends to replace several older modules and functions:


Use communicate() rather than .stdin.write, or to avoid deadlocks due to any of the other OS pipe buffers filling up and blocking the child process. Read Here

How can I concatenate a string within a loop in JSTL/JSP?

define a String variable using the JSP tags

String test = new String();

then refer to that variable in your loop as

<c:forEach items="${myParams.items}" var="currentItem" varStatus="stat">
test+= whaterver_value

macOS on VMware doesn't recognize iOS device

I have 2 computers with VMWare Workstation and Mac OS Sierra installed as the guest OS. First machine could recognize my iOS device whereas my second machine could not recognize it. The second machine was exhibiting the same behavior as others reported where it would reconnect and disconnect with the iPhone endlessly.

Thankfully, my second machine had network connectivity problems with my VM. So I stumbled upon the solution when I reset my network settings for the VM.

You can try the following steps and see if it works for you. It worked for me.

  1. Go to Start Menu.
  2. Open VMWare folder.
  3. Start VMWare Network Editor.
  4. Click Change Settings button to assign Administrator privileges.
  5. Click Restore Defaults button.
  6. Open Virtual Machine.
  7. Verify internet connectivity on Mac OS.
  8. Connect iOS device. If iTunes launches on Mac, this means that the Mac has correctly identified your iOS device.

Getting the current Fragment instance in the viewpager

by selecting an option, I need to update the fragment that is currently visible.

To get a reference to currently visible fragment, assume you have a reference to ViewPager as mPager. Then following steps will get a reference to currentFragment:

  1. PageAdapter adapter = mPager.getAdapter();
  2. int fragmentIndex = mPager.getCurrentItem();
  3. FragmentStatePagerAdapter fspa = (FragmentStatePagerAdapter)adapter;
  4. Fragment currentFragment = fspa.getItem(fragmentIndex);

The only cast used line 3 is valid usually. FragmentStatePagerAdapter is an useful adapter for a ViewPager.

Bash or KornShell (ksh)?

Bash is the benchmark, but that's mostly because you can be reasonably sure it's installed on every *nix out there. If you're planning to distribute the scripts, use Bash.

I can not really address the actual programming differences between the shells, unfortunately.

print variable and a string in python

From what I know, printing can be done in many ways

Here's what I follow:

Printing string with variables

a = 1
b = "ball"
print("I have", a, b)

Versus printing string with functions

a = 1
b = "ball"
print("I have" + str(a) + str(b))

In this case, str() is a function that takes a variable and spits out what its assigned to as a string

They both yield the same print, but in two different ways. I hope that was helpful

Passive Link in Angular 2 - <a href=""> equivalent

There are ways of doing it with angular2, but I strongly disagree this is a bug. I'm not familiarized with angular1, but this seems like a really wrong behavior even though as you claim is useful in some cases, but clearly this should not be the default behavior of any framework.

Disagreements aside you can write a simple directive that grabs all your links and check for href's content and if the length of it it's 0 you execute preventDefault(), here's a little example.

  selector : '[href]',
  host : {
    '(click)' : 'preventDefault($event)'
class MyInhertLink {
  @Input() href;
  preventDefault(event) {
    if(this.href.length == 0) event.preventDefault();

You can make it to work across your application by adding this directive in PLATFORM_DIRECTIVES

bootstrap(App, [provide(PLATFORM_DIRECTIVES, {useValue: MyInhertLink, multi: true})]);

Here's a plnkr with an example working.

What is the difference between PUT, POST and PATCH?

Quite logical the difference between PUT & PATCH w.r.t sending full & partial data for replacing/updating respectively. However, just couple of points as below

  1. Sometimes POST is considered as for updates w.r.t PUT for create
  2. Does HTTP mandates/checks for sending full vs partial data in PATCH? Otherwise, PATCH may be quite same as update as in PUT/POST

SQL Server Restore Error - Access is Denied

This also happens if the paths are correct, but the service account is not the owner of the data files (yet it still has enough rights for read/write access). This can occur if the permissions for the files were reset to match the permissions of the folder (of course, while the service was stopped).

The easiest solution in this case is to detach each database and attach it again (because when attaching the owner is changed to be the service account).

How to implement 2D vector array?

vector<int> adj[n]; // where n is number of rows in 2d vector.

How to define relative paths in Visual Studio Project?

If I get you right, you need ..\..\src

What is the difference between json.dump() and json.dumps() in python?

One notable difference in Python 2 is that if you're using ensure_ascii=False, dump will properly write UTF-8 encoded data into the file (unless you used 8-bit strings with extended characters that are not UTF-8):

dumps on the other hand, with ensure_ascii=False can produce a str or unicode just depending on what types you used for strings:

Serialize obj to a JSON formatted str using this conversion table. If ensure_ascii is False, the result may contain non-ASCII characters and the return value may be a unicode instance.

(emphasis mine). Note that it may still be a str instance as well.

Thus you cannot use its return value to save the structure into file without checking which format was returned and possibly playing with unicode.encode.

This of course is not valid concern in Python 3 any more, since there is no more this 8-bit/Unicode confusion.

As for load vs loads, load considers the whole file to be one JSON document, so you cannot use it to read multiple newline limited JSON documents from a single file.

How to use MapView in android using google map V2?

More complete sample from here and here.

Or you can check out my layout sample. p.s no need to put API key in the map view.

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

<LinearLayout xmlns:android=""


    <ListView android:id="@+id/nearby_lv"


Java correct way convert/cast object to Double

Also worth mentioning -- if you were forced to use an older Java version prior to 1.5, and you are trying to use Collections, you won't be able to parameterize the collection with a type such as Double.

You'll have to manually "box" to the class Double when adding new items, and "unbox" to the primitive double by parsing and casting, doing something like this:

LinkedList lameOldList = new LinkedList();
lameOldList.add( new Double(1.2) );
lameOldList.add( new Double(3.4) );
lameOldList.add( new Double(5.6) );

double total = 0.0;
for (int i = 0, len = lameOldList.size(); i < len; i++) {
  total += Double.valueOf( (Double)lameOldList.get(i) );

The old-school list will contain only type Object and so has to be cast to Double.

Also, you won't be able to iterate through the list with an enhanced-for-loop in early Java versions -- only with a for-loop.

Restore DB — Error RESTORE HEADERONLY is terminating abnormally.

This error can be caused by the permissions to the file, which you should check, however recently I noticed that the same is thrown if the file has been transferred and windows has marked the file as 'Encrypt Contents to Secure Data'.

You can find this by bringing up the .bak file properties and clicking the advanced button, it appears as the last check box on the dialog.

Hope that helps someone!

Javadoc link to method in other class

For the Javadoc tag @see, you don't need to use @link; Javadoc will create a link for you. Try


Here's more info about @see.

load iframe in bootstrap modal

It seems that your

$(".modal").on('')   // One way Or

You can do this in a slight different way, like this

    // Send the src on click of button to the iframe. Which will make it load.
    // Hide the loading message
    $(".openifrmahere").find('iframe').load(function() {

Click toggle with jQuery

jQuery: Best Way, delegate the actions to jQuery (jQuery = jQuery).

$( "input[type='checkbox']" ).prop( "checked", function( i, val ) {
    return !val;

How to validate domain credentials?

Here's how to determine a local user:

    public bool IsLocalUser()
        return windowsIdentity.AuthenticationType == "NTLM";

Edit by Ian Boyd

You should not use NTLM anymore at all. It is so old, and so bad, that Microsoft's Application Verifier (which is used to catch common programming mistakes) will throw a warning if it detects you using NTLM.

Here's a chapter from the Application Verifier documentation about why they have a test if someone is mistakenly using NTLM:

Why the NTLM Plug-in is Needed

NTLM is an outdated authentication protocol with flaws that potentially compromise the security of applications and the operating system. The most important shortcoming is the lack of server authentication, which could allow an attacker to trick users into connecting to a spoofed server. As a corollary of missing server authentication, applications using NTLM can also be vulnerable to a type of attack known as a “reflection” attack. This latter allows an attacker to hijack a user’s authentication conversation to a legitimate server and use it to authenticate the attacker to the user’s computer. NTLM’s vulnerabilities and ways of exploiting them are the target of increasing research activity in the security community.

Although Kerberos has been available for many years many applications are still written to use NTLM only. This needlessly reduces the security of applications. Kerberos cannot however replace NTLM in all scenarios – principally those where a client needs to authenticate to systems that are not joined to a domain (a home network perhaps being the most common of these). The Negotiate security package allows a backwards-compatible compromise that uses Kerberos whenever possible and only reverts to NTLM when there is no other option. Switching code to use Negotiate instead of NTLM will significantly increase the security for our customers while introducing few or no application compatibilities. Negotiate by itself is not a silver bullet – there are cases where an attacker can force downgrade to NTLM but these are significantly more difficult to exploit. However, one immediate improvement is that applications written to use Negotiate correctly are automatically immune to NTLM reflection attacks.

By way of a final word of caution against use of NTLM: in future versions of Windows it will be possible to disable the use of NTLM at the operating system. If applications have a hard dependency on NTLM they will simply fail to authenticate when NTLM is disabled.

How the Plug-in Works

The Verifier plug detects the following errors:

  • The NTLM package is directly specified in the call to AcquireCredentialsHandle (or higher level wrapper API).

  • The target name in the call to InitializeSecurityContext is NULL.

  • The target name in the call to InitializeSecurityContext is not a properly-formed SPN, UPN or NetBIOS-style domain name.

The latter two cases will force Negotiate to fall back to NTLM either directly (the first case) or indirectly (the domain controller will return a “principal not found” error in the second case causing Negotiate to fall back).

The plug-in also logs warnings when it detects downgrades to NTLM; for example, when an SPN is not found by the Domain Controller. These are only logged as warnings since they are often legitimate cases – for example, when authenticating to a system that is not domain-joined.

NTLM Stops

5000 – Application Has Explicitly Selected NTLM Package

Severity – Error

The application or subsystem explicitly selects NTLM instead of Negotiate in the call to AcquireCredentialsHandle. Even though it may be possible for the client and server to authenticate using Kerberos this is prevented by the explicit selection of NTLM.

How to Fix this Error

The fix for this error is to select the Negotiate package in place of NTLM. How this is done will depend on the particular Network subsystem being used by the client or server. Some examples are given below. You should consult the documentation on the particular library or API set that you are using.

APIs(parameter) Used by Application    Incorrect Value  Correct Value  
=====================================  ===============  ========================
AcquireCredentialsHandle (pszPackage)  “NTLM”           NEGOSSP_NAME “Negotiate”

MYSQL query between two timestamps

Try this its worked for me

SELECT * from bookedroom
    WHERE UNIX_TIMESTAMP('2020-8-07 5:31')
        between UNIX_TIMESTAMP('2020-8-07 5:30') and
        UNIX_TIMESTAMP('2020-8-09 5:30')

Find something in column A then show the value of B for that row in Excel 2010

I note you suggested this formula


.....but LOOKUP isn't appropriate here because I assume you want an exact match (LOOKUP won't guarantee that and also data in lookup range has to be sorted), so VLOOKUP or INDEX/MATCH would be better....and you can also use IFERROR to avoid the IF function, i.e


Note: VLOOKUP always looks up the lookup value (A9) in the first column of the "table array" and returns a value from the nth column of the "table array" where n is defined by col_index_num, in this case 9

INDEX/MATCH is sometimes more flexible because you can explicitly define the lookup column and the return column (and return column can be to the left of the lookup column which can't be the case in VLOOKUP), so that would look like this:


INDEX/MATCH also allows you to more easily return multiple values from different columns, e.g. by using $ signs in front of A9 and the lookup range Ruhrpumpen!A$5:A$100, i.e.


this version can be dragged across to get successive values from column I, column J, column K etc.....

Check if event exists on element

To check for events on an element:

var events = $._data(element, "events")

Note that this will only work with direct event handlers, if you are using $(document).on("event-name", "jq-selector", function() { //logic }), you will want to see the getEvents function at the bottom of this answer

For example:

 var events = $._data(document.getElementById("myElemId"), "events")


 var events = $._data($("#myElemId")[0], "events")

Full Example:

        <script src="//" type="text/javascript"></script>
            $(function() {
                $("#textDiv").click(function() {
                    //Event Handling
                var events = $._data(document.getElementById('textDiv'), "events");
                var hasEvents = (events != null);
        <div id="textDiv">Text</div>

A more complete way to check, that includes dynamic listeners, installed with $(document).on

function getEvents(element) {
    var elemEvents = $._data(element, "events");
    var allDocEvnts = $._data(document, "events");
    for(var evntType in allDocEvnts) {
        if(allDocEvnts.hasOwnProperty(evntType)) {
            var evts = allDocEvnts[evntType];
            for(var i = 0; i < evts.length; i++) {
                if($(element).is(evts[i].selector)) {
                    if(elemEvents == null) {
                        elemEvents = {};
                    if(!elemEvents.hasOwnProperty(evntType)) {
                        elemEvents[evntType] = [];
    return elemEvents;

Example usage:


Combine two (or more) PDF's

I've done this with PDFBox. I suppose it works similarly to iTextSharp.

IntelliJ: Error:java: error: release version 5 not supported

The only working solution in my case was adding the following block to pom.xml:

            <version>3.8.0</version> <configuration> <release>12</release>

Visual Studio "Could not copy" .... during build

I have noticed some answers that solved my problem, BUT, just in case anyone is having the same problem I was.


Make sure you have closed out any console windows that may have been opened from a previous build. For instance I was just testing some code in a console application, I didn't realize that the console window from one of the previous times I ran my program was open. During that session I was debugging, the window got pushed to the back and I couldn't see it. Just saying, this could be your problem, so check to make sure that is not the problem.

Formatting struct timespec

I wanted to ask the same question. Here is my current solution to obtain a string like this: 2013-02-07 09:24:40.749355372 I am not sure if there is a more straight forward solution than this, but at least the string format is freely configurable with this approach.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#define NANO 1000000000L

// buf needs to store 30 characters
int timespec2str(char *buf, uint len, struct timespec *ts) {
    int ret;
    struct tm t;

    if (localtime_r(&(ts->tv_sec), &t) == NULL)
        return 1;

    ret = strftime(buf, len, "%F %T", &t);
    if (ret == 0)
        return 2;
    len -= ret - 1;

    ret = snprintf(&buf[strlen(buf)], len, ".%09ld", ts->tv_nsec);
    if (ret >= len)
        return 3;

    return 0;

int main(int argc, char **argv) {
    clockid_t clk_id = CLOCK_REALTIME;
    const uint TIME_FMT = strlen("2012-12-31 12:59:59.123456789") + 1;
    char timestr[TIME_FMT];

    struct timespec ts, res;
    clock_getres(clk_id, &res);
    clock_gettime(clk_id, &ts);

    if (timespec2str(timestr, sizeof(timestr), &ts) != 0) {
        printf("timespec2str failed!\n");
        return EXIT_FAILURE;
    } else {
        unsigned long resol = res.tv_sec * NANO + res.tv_nsec;
        printf("CLOCK_REALTIME: res=%ld ns, time=%s\n", resol, timestr);
        return EXIT_SUCCESS;


gcc mwe.c -lrt 
$ ./a.out 
CLOCK_REALTIME: res=1 ns, time=2013-02-07 13:41:17.994326501

Difference between abstraction and encapsulation?

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

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

How can I open a link in a new window?

This is not a very nice fix but it works:


    display: none;


<a data-href="" href="javascript:">Click here</a>
<form class="new-tab-opener" method="get" target="_blank"></form>


$('a').on('click', function (e) {    
    var f = $('.new-tab-opener');
    f.attr('action', $(this).attr('data-href'));

Live example:

SQL Order By Count

You need to aggregate the data first, this can be done using the GROUP BY clause:

FROM table

The DESC keyword allows you to show the highest count first, ORDER BY by default orders in ascending order which would show the lowest count first.


In standard SQL this type of update looks like:

update a
   set a.firstfield ='BIT OF TEXT' + b.something
  from file1 a
  join file2 b
    on substr(a.firstfield,10,20) = 
 where a.firstfield like 'BLAH%' 

With minor syntactic variations this type of thing will work on Oracle or SQL Server and (although I don't have a DB/2 instance to hand to test) will almost certainly work on DB/2.

javascript function wait until another function to finish

Following answer can help in this and other similar situations like synchronous AJAX call -

Working example

  console.log('Finally, I can execute!!!');
  console.log('This is error message.');

function waitForMe(){
    // Returns promise
    console.log('Inside waitForMe');
    return new Promise(function(resolve, reject){
        if(true){ // Try changing to 'false'
                console.log('waitForMe\'s function succeeded');
            }, 2500);
                console.log('waitForMe\'s else block failed');
            }, 2500);

Simple PowerShell LastWriteTime compare

Try the following.

$d = [datetime](Get-ItemProperty -Path $source -Name LastWriteTime).lastwritetime

This is part of the item property weirdness. When you run Get-ItemProperty it does not return the value but instead the property. You have to use one more level of indirection to get to the value.

str_replace with array

Alternatively to the answer marked as correct, if you have to replace words instead of chars you can do it with this piece of code :

$query = "INSERT INTO my_table VALUES (?, ?, ?, ?);";
$values = Array("apple", "oranges", "mangos", "papayas");
foreach (array_fill(0, count($values), '?') as $key => $wildcard) {
    $query = substr_replace($query, '"'.$values[$key].'"', strpos($query, $wildcard), strlen($wildcard));
echo $query;

Demo here :

How to fix an UnsatisfiedLinkError (Can't find dependent libraries) in a JNI project

Creating static library worked for me, compiling using g++ -static. It bundles the dependent libraries along with the build.

How to remove not null constraint in sql server using query

 ALTER TABLE YourTable ALTER COLUMN YourColumn columnType NULL

Getting JavaScript object key list

          var data = []

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

Everyone knows (hopefully) its bad to terminate thread. The problem is when you don't own a piece of code you're calling. If this code is running in some do/while infinite loop , itself calling some native functions, etc. you're basically stuck. When this happens in your own code termination, stop or Dispose call, it's kinda ok to start shooting the bad guys (so you don't become a bad guy yourself).

So, for what it's worth, I've written those two blocking functions that use their own native thread, not a thread from the pool or some thread created by the CLR. They will stop the thread if a timeout occurs:

// returns true if the call went to completion successfully, false otherwise
public static bool RunWithAbort(this Action action, int milliseconds) => RunWithAbort(action, new TimeSpan(0, 0, 0, 0, milliseconds));
public static bool RunWithAbort(this Action action, TimeSpan delay)
    if (action == null)
        throw new ArgumentNullException(nameof(action));

    var source = new CancellationTokenSource(delay);
    var success = false;
    var handle = IntPtr.Zero;
    var fn = new Action(() =>
        using (source.Token.Register(() => TerminateThread(handle, 0)))
            success = true;

    handle = CreateThread(IntPtr.Zero, IntPtr.Zero, fn, IntPtr.Zero, 0, out var id);
    WaitForSingleObject(handle, 100 + (int)delay.TotalMilliseconds);
    return success;

// returns what's the function should return if the call went to completion successfully, default(T) otherwise
public static T RunWithAbort<T>(this Func<T> func, int milliseconds) => RunWithAbort(func, new TimeSpan(0, 0, 0, 0, milliseconds));
public static T RunWithAbort<T>(this Func<T> func, TimeSpan delay)
    if (func == null)
        throw new ArgumentNullException(nameof(func));

    var source = new CancellationTokenSource(delay);
    var item = default(T);
    var handle = IntPtr.Zero;
    var fn = new Action(() =>
        using (source.Token.Register(() => TerminateThread(handle, 0)))
            item = func();

    handle = CreateThread(IntPtr.Zero, IntPtr.Zero, fn, IntPtr.Zero, 0, out var id);
    WaitForSingleObject(handle, 100 + (int)delay.TotalMilliseconds);
    return item;

private static extern bool TerminateThread(IntPtr hThread, int dwExitCode);

private static extern IntPtr CreateThread(IntPtr lpThreadAttributes, IntPtr dwStackSize, Delegate lpStartAddress, IntPtr lpParameter, int dwCreationFlags, out int lpThreadId);

private static extern bool CloseHandle(IntPtr hObject);

private static extern int WaitForSingleObject(IntPtr hHandle, int dwMilliseconds);

SOAP vs REST (differences)

REST vs SOAP is not the right question to ask.

REST, unlike SOAP is not a protocol.

REST is an architectural style and a design for network-based software architectures.

REST concepts are referred to as resources. A representation of a resource must be stateless. It is represented via some media type. Some examples of media types include XML, JSON, and RDF. Resources are manipulated by components. Components request and manipulate resources via a standard uniform interface. In the case of HTTP, this interface consists of standard HTTP ops e.g. GET, PUT, POST, DELETE.

@Abdulaziz's question does illuminate the fact that REST and HTTP are often used in tandem. This is primarily due to the simplicity of HTTP and its very natural mapping to RESTful principles.

Fundamental REST Principles

Client-Server Communication

Client-server architectures have a very distinct separation of concerns. All applications built in the RESTful style must also be client-server in principle.


Each client request to the server requires that its state be fully represented. The server must be able to completely understand the client request without using any server context or server session state. It follows that all state must be kept on the client.


Cache constraints may be used, thus enabling response data to be marked as cacheable or not-cacheable. Any data marked as cacheable may be reused as the response to the same subsequent request.

Uniform Interface

All components must interact through a single uniform interface. Because all component interaction occurs via this interface, interaction with different services is very simple. The interface is the same! This also means that implementation changes can be made in isolation. Such changes, will not affect fundamental component interaction because the uniform interface is always unchanged. One disadvantage is that you are stuck with the interface. If an optimization could be provided to a specific service by changing the interface, you are out of luck as REST prohibits this. On the bright side, however, REST is optimized for the web, hence incredible popularity of REST over HTTP!

The above concepts represent defining characteristics of REST and differentiate the REST architecture from other architectures like web services. It is useful to note that a REST service is a web service, but a web service is not necessarily a REST service.

See this blog post on REST Design Principles for more details on REST and the above stated bullets.

EDIT: update content based on comments

How to write LDAP query to test if user is member of a group?

You should be able to create a query with this filter here:


and when you run that against your LDAP server, if you get a result, your user "yourUserName" is indeed a member of the group "CN=YourGroup,OU=Users,DC=YourDomain,DC=com

Try and see if this works!

If you use C# / VB.Net and System.DirectoryServices, this snippet should do the trick:

DirectoryEntry rootEntry = new DirectoryEntry("LDAP://dc=yourcompany,dc=com");

DirectorySearcher srch = new DirectorySearcher(rootEntry);
srch.SearchScope = SearchScope.Subtree;

srch.Filter = "(&(objectClass=user)(sAMAccountName=yourusername)(memberOf=CN=yourgroup,OU=yourOU,DC=yourcompany,DC=com))";

SearchResultCollection res = srch.FindAll();

if(res == null || res.Count <= 0) {
    Console.WriteLine("This user is *NOT* member of that group");
} else {
    Console.WriteLine("This user is INDEED a member of that group");

Word of caution: this will only test for immediate group memberships, and it will not test for membership in what is called the "primary group" (usually "cn=Users") in your domain. It does not handle nested memberships, e.g. User A is member of Group A which is member of Group B - that fact that User A is really a member of Group B as well doesn't get reflected here.


Python sys.argv lists and indexes

In a nutshell, sys.argv is a list of the words that appear in the command used to run the program. The first word (first element of the list) is the name of the program, and the rest of the elements of the list are any arguments provided. In most computer languages (including Python), lists are indexed from zero, meaning that the first element in the list (in this case, the program name) is sys.argv[0], and the second element (first argument, if there is one) is sys.argv[1], etc.

The test len(sys.argv) >= 2 simply checks wither the list has a length greater than or equal to 2, which will be the case if there was at least one argument provided to the program.

What is the difference between properties and attributes in HTML?

The answers already explain how attributes and properties are handled differently, but I really would like to point out how totally insane this is. Even if it is to some extent the spec.

It is crazy, to have some of the attributes (e.g. id, class, foo, bar) to retain only one kind of value in the DOM, while some attributes (e.g. checked, selected) to retain two values; that is, the value "when it was loaded" and the value of the "dynamic state". (Isn't the DOM supposed to be to represent the state of the document to its full extent?)

It is absolutely essential, that two input fields, e.g. a text and a checkbox behave the very same way. If the text input field does not retain a separate "when it was loaded" value and the "current, dynamic" value, why does the checkbox? If the checkbox does have two values for the checked attribute, why does it not have two for its class and id attributes? If you expect to change the value of a text *input* field, and you expect the DOM (i.e. the "serialized representation") to change, and reflect this change, why on earth would you not expect the same from an input field of type checkbox on the checked attribute?

The differentiation, of "it is a boolean attribute" just does not make any sense to me, or is, at least not a sufficient reason for this.

React Native TextInput that only accepts numeric characters

<TextInput autoCapitalize={'none'} maxLength={10} placeholder='Mobile Number'  value={} onChangeText={(mobile) => this.onChanged(mobile)}/>

and onChanged method :

   var newText = '';
   var numbers = '0123456789';
   if(text.length < 1){
     this.setState({ mobile: '' });
   for (var i=0; i < text.length; i++) {
        if(numbers.indexOf(text[i]) > -1 ) {
             newText = newText + text[i];
        this.setState({ mobile: newText });

Will using 'var' affect performance?

There's no extra IL code for the var keyword: the resulting IL should be identical for non-anonymous types. If the compiler can't create that IL because it can't figure out what type you intended to use, you'll get a compiler error.

The only trick is that var will infer an exact type where you may have chosen an Interface or parent type if you were to set the type manually.

Update 8 Years Later

I need to update this as my understanding has changed. I now believe it may be possible for var to affect performance in the situation where a method returns an interface, but you would have used an exact type. For example, if you have this method:

IList<int> Foo()
    return Enumerable.Range(0,10).ToList();

Consider these three lines of code to call the method:

List<int> bar1 = Foo();
IList<int> bar = Foo();
var bar3 = Foo();

All three compile and execute as expected. However, the first two lines are not exactly the same, and the third line will match the second, rather than the first. Because the signature of Foo() is to return an IList<int>, that is how the compiler will build the bar3 variable.

From a performance standpoint, mostly you won't notice. However, there are situations where the performance of the third line may not be quite as fast as the performance of the first. As you continue to use the bar3 variable, the compiler may not be able to dispatch method calls the same way.

Note that it's possible (likely even) the jitter will be able to erase this difference, but it's not guaranteed. Generally, you should still consider var to be a non-factor in terms of performance. It's certainly not at all like using a dynamic variable. But to say it never makes a difference at all may be overstating it.

How do you specify a byte literal in Java?

What about overriding the method with

void f(int value)

this will allow for f(0)

OS X Bash, 'watch' command

You can emulate the basic functionality with the shell loop:

while :; do clear; your_command; sleep 2; done

That will loop forever, clear the screen, run your command, and wait two seconds - the basic watch your_command implementation.

You can take this a step further and create a script that can accept your_command and sleep_duration as parameters:

# usage: <your_command> <sleep_duration>

while :; 
  sleep $2

no such file to load -- rubygems (LoadError)

I had a similar problem and solved that by setting up RUBYLIB env.

In my environment I used this:

export RUBYLIB=$ruby_dir/lib/ruby/1.9.1/:$ruby_dir/lib/ruby/1.9.1/i686-linux/:$RUBYLIB

sklearn: Found arrays with inconsistent numbers of samples when calling

It looks like sklearn requires the data shape of (row number, column number). If your data shape is (row number, ) like (999, ), it does not work. By using numpy.reshape(), you should change the shape of the array to (999, 1), e.g. using


In my case, it worked with that.

How do I remove the file suffix and path portion from a path string in Bash?

Combining the top-rated answer with the second-top-rated answer to get the filename without the full path:

$ x="/foo/"
$ y=(`basename ${x%%.*}`)
$ echo $y

Draw text in OpenGL ES

I looked at the sprite text example and it looks awfully complicated for such a task, I considered rendering to a texture too, but I'm worried about the performance hit that might cause. I might just have to go with a view instead and worry about porting when it's time to cross that bridge :)

Angular2: Cannot read property 'name' of undefined

The variable selectedHero is null in the template so you cannot bind as is. You need to use the elvis operator ?. for this case:

<input [ngModel]="selectedHero?.name" (ngModelChange)=" = $event" />

The separation of the [(ngModel)] into [ngModel] and (ngModelChange) is also needed because you can't assign to an expression that uses the elvis operator.

I also think you mean to use:

<h2>{{selectedHero?.name}} details!</h2>

instead of:

<h2>{{}} details!</h2>

Verify object attribute value with mockito

This is answer based on answer from iraSenthil but with annotation (Captor). In my opinion it has some advantages:

  • it's shorter
  • it's easier to read
  • it can handle generics without warnings


public class SomeTest{

    private ArgumentCaptor<List<SomeType>> captor;


    public void shouldTestArgsVals() {

        assertThat(captor.getValue().getXXX(), is("expected"));

How to run a script at a certain time on Linux?

Cron is good for something that will run periodically, like every Saturday at 4am. There's also anacron, which works around power shutdowns, sleeps, and whatnot. As well as at.

But for a one-off solution, that doesn't require root or anything, you can just use date to compute the seconds-since-epoch of the target time as well as the present time, then use expr to find the difference, and sleep that many seconds.

correct configuration for nginx to localhost?

Fundamentally you hadn't declare location which is what nginx uses to bind URL with resources.

 server {
            listen       80;
            server_name  localhost;

            access_log  logs/localhost.access.log  main;

            location / {
                root /var/www/board/public;
                index index.html index.htm index.php;

Concatenate string with field value in MySQL

SELECT ..., CONCAT( 'category_id=', tableOne.category_id) as query2  FROM tableOne 
LEFT JOIN tableTwo
ON tableTwo.query = query2

Check if any type of files exist in a directory using BATCH script

For files in a directory, you can use things like:

if exist *.csv echo "csv file found"


if not exist *.csv goto nofile

How To Set A JS object property name from a variable

It does not matter where the variable comes from. Main thing we have one ... Set the variable name between square brackets "[ .. ]".

var optionName = 'nameA';
var JsonVar = {
[optionName] : 'some value'

Script to get the HTTP status code of a list of urls?

Curl has a specific option, --write-out, for this:

$ curl -o /dev/null --silent --head --write-out '%{http_code}\n' <url>
  • -o /dev/null throws away the usual output
  • --silent throws away the progress meter
  • --head makes a HEAD HTTP request, instead of GET
  • --write-out '%{http_code}\n' prints the required status code

To wrap this up in a complete Bash script:

while read LINE; do
  curl -o /dev/null --silent --head --write-out "%{http_code} $LINE\n" "$LINE"
done < url-list.txt

(Eagle-eyed readers will notice that this uses one curl process per URL, which imposes fork and TCP connection penalties. It would be faster if multiple URLs were combined in a single curl, but there isn't space to write out the monsterous repetition of options that curl requires to do this.)

Get Insert Statement for existing row in MySQL

Within MySQL work bench perform the following:

  1. Click Server > Data Export

  2. In the Object Selection Tab select the desired schema.

  3. Next, select the desired tables using the list box to the right of the schema.

  4. Select a file location to export the script.

  5. Click Finish.

  6. Navigate to the newly created file and copy the insert statements.

how to get yesterday's date in C#

You don't need to call DateTime.Today multiple times, just use it single time and format the date object in your desire format.. like that

 string result = DateTime.Now.Date.AddDays(-1).ToString("yyyy-MM-dd");


 string result = DateTime.Today.AddDays(-1).ToString("yyyy-MM-dd");

How can I check if a string represents an int, without using try/except?

I think

s.startswith('-') and s[1:].isdigit()

would be better to rewrite to:

s.replace('-', '').isdigit()

because s[1:] also creates a new string

But much better solution is


Ctrl+click doesn't work in Eclipse Juno

I encounter this problem when creating workspace/project in eclipse 3.7.2. Then I open it using Kepler (4.3). So simply open the project by the eclipse version you created it (3.7.2 in my case) solves the problem. Hope it helps.

How do I configure Apache 2 to run Perl CGI scripts?

As of Ubuntu 12.04 (Precise Pangolin) (and perhaps a release or two before) simply installing apache2 and mod-perl via Synaptic and placing your CGI scripts in /usr/lib/cgi-bin is really all you need to do.

Printing a char with printf

In C, character constant expressions such as '\n' or 'a' have type int (thus sizeof '\n' == sizeof (int)), whereas in C++ they have type char.

The statement printf("%d", '\0'); should simply print 0; the type of the expression '\0' is int, and its value is 0.

The statement printf("%d", ch); should print the integer encoding for the value in ch (for ASCII, 'a' == 97).

How to set time to midnight for current day?

I believe you are looking for DateTime.Today. The documentation states:

An object that is set to today's date, with the time component set to 00:00:00.

Your code would be

DateTime _Begin = DateTime.Today;

GCM with PHP (Google Cloud Messaging)

use this

 function pnstest(){

                $data = array('post_id'=>'12345','title'=>'A Blog post', 'message' =>'test msg');

                $url = '';

                $server_key = 'AIzaSyDVpDdS7EyNgMUpoZV6sI2p-cG';

                $target ='fO3JGJw4CXI:APA91bFKvHv8wzZ05w2JQSor6D8lFvEGE_jHZGDAKzFmKWc73LABnumtRosWuJx--I4SoyF1XQ4w01P77MKft33grAPhA8g-wuBPZTgmgttaC9U4S3uCHjdDn5c3YHAnBF3H';

                $fields = array();
                $fields['data'] = $data;
                    $fields['registration_ids'] = $target;
                    $fields['to'] = $target;

                //header with content_type api key
                $headers = array(

                $ch = curl_init();
                curl_setopt($ch, CURLOPT_URL, $url);
                curl_setopt($ch, CURLOPT_POST, true);
                curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
                curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
                curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
                curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
                curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($fields));
                $result = curl_exec($ch);
                if ($result === FALSE) {
                    die('FCM Send Error: ' . curl_error($ch));
                return $result;


C++ equivalent of java's instanceof

Instanceof implementation without dynamic_cast

I think this question is still relevant today. Using the C++11 standard you are now able to implement a instanceof function without using dynamic_cast like this:

if (dynamic_cast<B*>(aPtr) != nullptr) {
  // aPtr is instance of B
} else {
  // aPtr is NOT instance of B

But you're still reliant on RTTI support. So here is my solution for this problem depending on some Macros and Metaprogramming Magic. The only drawback imho is that this approach does not work for multiple inheritance.


#include <set>
#include <tuple>
#include <typeindex>

#define _EMPTY_BASE_TYPE_DECL() using BaseTypes = std::tuple<>;
#define _BASE_TYPE_DECL(Class, BaseClass) \
  using BaseTypes = decltype(std::tuple_cat(std::tuple<BaseClass>(), Class::BaseTypes()));
#define _INSTANCE_OF_DECL_BODY(Class)                                 \
  static const std::set<std::type_index> baseTypeContainer;           \
  virtual bool instanceOfHelper(const std::type_index &_tidx) {       \
    if (std::type_index(typeid(ThisType)) == _tidx) return true;      \
    if (std::tuple_size<BaseTypes>::value == 0) return false;         \
    return baseTypeContainer.find(_tidx) != baseTypeContainer.end();  \
  }                                                                   \
  template <typename... T>                                            \
  static std::set<std::type_index> getTypeIndexes(std::tuple<T...>) { \
    return std::set<std::type_index>{std::type_index(typeid(T))...};  \

#define INSTANCE_OF_SUB_DECL(Class, BaseClass) \
 protected:                                    \
  using ThisType = Class;                      \
  _BASE_TYPE_DECL(Class, BaseClass)            \

#define INSTANCE_OF_BASE_DECL(Class)                                                    \
 protected:                                                                             \
  using ThisType = Class;                                                               \
  _EMPTY_BASE_TYPE_DECL()                                                               \
  _INSTANCE_OF_DECL_BODY(Class)                                                         \
 public:                                                                                \
  template <typename Of>                                                                \
  typename std::enable_if<std::is_base_of<Class, Of>::value, bool>::type instanceOf() { \
    return instanceOfHelper(std::type_index(typeid(Of)));                               \

#define INSTANCE_OF_IMPL(Class) \
  const std::set<std::type_index> Class::baseTypeContainer = Class::getTypeIndexes(Class::BaseTypes());


You can then use this stuff (with caution) as follows:


#include "InstanceOfMacros.h"

struct A {
  virtual ~A() {}

struct B : public A {
  virtual ~B() {}

struct C : public A {
  virtual ~C() {}

struct D : public C {
  virtual ~D() {}

The following code presents a small demo to verify rudimentary the correct behavior.


#include <iostream>
#include <memory>
#include "DemoClassHierarchy.hpp"

int main() {
  A *a2aPtr = new A;
  A *a2bPtr = new B;
  std::shared_ptr<A> a2cPtr(new C);
  C *c2dPtr = new D;
  std::unique_ptr<A> a2dPtr(new D);

  std::cout << "a2aPtr->instanceOf<A>(): expected=1, value=" << a2aPtr->instanceOf<A>() << std::endl;
  std::cout << "a2aPtr->instanceOf<B>(): expected=0, value=" << a2aPtr->instanceOf<B>() << std::endl;
  std::cout << "a2aPtr->instanceOf<C>(): expected=0, value=" << a2aPtr->instanceOf<C>() << std::endl;
  std::cout << "a2aPtr->instanceOf<D>(): expected=0, value=" << a2aPtr->instanceOf<D>() << std::endl;
  std::cout << std::endl;
  std::cout << "a2bPtr->instanceOf<A>(): expected=1, value=" << a2bPtr->instanceOf<A>() << std::endl;
  std::cout << "a2bPtr->instanceOf<B>(): expected=1, value=" << a2bPtr->instanceOf<B>() << std::endl;
  std::cout << "a2bPtr->instanceOf<C>(): expected=0, value=" << a2bPtr->instanceOf<C>() << std::endl;
  std::cout << "a2bPtr->instanceOf<D>(): expected=0, value=" << a2bPtr->instanceOf<D>() << std::endl;
  std::cout << std::endl;
  std::cout << "a2cPtr->instanceOf<A>(): expected=1, value=" << a2cPtr->instanceOf<A>() << std::endl;
  std::cout << "a2cPtr->instanceOf<B>(): expected=0, value=" << a2cPtr->instanceOf<B>() << std::endl;
  std::cout << "a2cPtr->instanceOf<C>(): expected=1, value=" << a2cPtr->instanceOf<C>() << std::endl;
  std::cout << "a2cPtr->instanceOf<D>(): expected=0, value=" << a2cPtr->instanceOf<D>() << std::endl;
  std::cout << std::endl;
  std::cout << "c2dPtr->instanceOf<A>(): expected=1, value=" << c2dPtr->instanceOf<A>() << std::endl;
  std::cout << "c2dPtr->instanceOf<B>(): expected=0, value=" << c2dPtr->instanceOf<B>() << std::endl;
  std::cout << "c2dPtr->instanceOf<C>(): expected=1, value=" << c2dPtr->instanceOf<C>() << std::endl;
  std::cout << "c2dPtr->instanceOf<D>(): expected=1, value=" << c2dPtr->instanceOf<D>() << std::endl;
  std::cout << std::endl;
  std::cout << "a2dPtr->instanceOf<A>(): expected=1, value=" << a2dPtr->instanceOf<A>() << std::endl;
  std::cout << "a2dPtr->instanceOf<B>(): expected=0, value=" << a2dPtr->instanceOf<B>() << std::endl;
  std::cout << "a2dPtr->instanceOf<C>(): expected=1, value=" << a2dPtr->instanceOf<C>() << std::endl;
  std::cout << "a2dPtr->instanceOf<D>(): expected=1, value=" << a2dPtr->instanceOf<D>() << std::endl;

  delete a2aPtr;
  delete a2bPtr;
  delete c2dPtr;

  return 0;


a2aPtr->instanceOf<A>(): expected=1, value=1
a2aPtr->instanceOf<B>(): expected=0, value=0
a2aPtr->instanceOf<C>(): expected=0, value=0
a2aPtr->instanceOf<D>(): expected=0, value=0

a2bPtr->instanceOf<A>(): expected=1, value=1
a2bPtr->instanceOf<B>(): expected=1, value=1
a2bPtr->instanceOf<C>(): expected=0, value=0
a2bPtr->instanceOf<D>(): expected=0, value=0

a2cPtr->instanceOf<A>(): expected=1, value=1
a2cPtr->instanceOf<B>(): expected=0, value=0
a2cPtr->instanceOf<C>(): expected=1, value=1
a2cPtr->instanceOf<D>(): expected=0, value=0

c2dPtr->instanceOf<A>(): expected=1, value=1
c2dPtr->instanceOf<B>(): expected=0, value=0
c2dPtr->instanceOf<C>(): expected=1, value=1
c2dPtr->instanceOf<D>(): expected=1, value=1

a2dPtr->instanceOf<A>(): expected=1, value=1
a2dPtr->instanceOf<B>(): expected=0, value=0
a2dPtr->instanceOf<C>(): expected=1, value=1
a2dPtr->instanceOf<D>(): expected=1, value=1


The most interesting question which now arises is, if this evil stuff is more efficient than the usage of dynamic_cast. Therefore I've written a very basic performance measurement app.


#include <chrono>
#include <iostream>
#include <string>
#include "DemoClassHierarchy.hpp"

template <typename Base, typename Derived, typename Duration>
Duration instanceOfMeasurement(unsigned _loopCycles) {
  auto start = std::chrono::high_resolution_clock::now();
  volatile bool isInstanceOf = false;
  for (unsigned i = 0; i < _loopCycles; ++i) {
    Base *ptr = new Derived;
    isInstanceOf = ptr->template instanceOf<Derived>();
    delete ptr;
  auto end = std::chrono::high_resolution_clock::now();
  return std::chrono::duration_cast<Duration>(end - start);

template <typename Base, typename Derived, typename Duration>
Duration dynamicCastMeasurement(unsigned _loopCycles) {
  auto start = std::chrono::high_resolution_clock::now();
  volatile bool isInstanceOf = false;
  for (unsigned i = 0; i < _loopCycles; ++i) {
    Base *ptr = new Derived;
    isInstanceOf = dynamic_cast<Derived *>(ptr) != nullptr;
    delete ptr;
  auto end = std::chrono::high_resolution_clock::now();
  return std::chrono::duration_cast<Duration>(end - start);

int main() {
  unsigned testCycles = 10000000;
  std::string unit = " us";
  using DType = std::chrono::microseconds;

  std::cout << "InstanceOf performance(A->D)  : " << instanceOfMeasurement<A, D, DType>(testCycles).count() << unit
            << std::endl;
  std::cout << "InstanceOf performance(A->C)  : " << instanceOfMeasurement<A, C, DType>(testCycles).count() << unit
            << std::endl;
  std::cout << "InstanceOf performance(A->B)  : " << instanceOfMeasurement<A, B, DType>(testCycles).count() << unit
            << std::endl;
  std::cout << "InstanceOf performance(A->A)  : " << instanceOfMeasurement<A, A, DType>(testCycles).count() << unit
            << "\n"
            << std::endl;
  std::cout << "DynamicCast performance(A->D) : " << dynamicCastMeasurement<A, D, DType>(testCycles).count() << unit
            << std::endl;
  std::cout << "DynamicCast performance(A->C) : " << dynamicCastMeasurement<A, C, DType>(testCycles).count() << unit
            << std::endl;
  std::cout << "DynamicCast performance(A->B) : " << dynamicCastMeasurement<A, B, DType>(testCycles).count() << unit
            << std::endl;
  std::cout << "DynamicCast performance(A->A) : " << dynamicCastMeasurement<A, A, DType>(testCycles).count() << unit
            << "\n"
            << std::endl;
  return 0;

The results vary and are essentially based on the degree of compiler optimization. Compiling the performance measurement program using g++ -std=c++11 -O0 -o instanceof-performance InstanceOfPerformance.cpp the output on my local machine was:

InstanceOf performance(A->D)  : 699638 us
InstanceOf performance(A->C)  : 642157 us
InstanceOf performance(A->B)  : 671399 us
InstanceOf performance(A->A)  : 626193 us

DynamicCast performance(A->D) : 754937 us
DynamicCast performance(A->C) : 706766 us
DynamicCast performance(A->B) : 751353 us
DynamicCast performance(A->A) : 676853 us

Mhm, this result was very sobering, because the timings demonstrates that the new approach is not much faster compared to the dynamic_cast approach. It is even less efficient for the special test case which tests if a pointer of A is an instance ofA. BUT the tide turns by tuning our binary using compiler otpimization. The respective compiler command is g++ -std=c++11 -O3 -o instanceof-performance InstanceOfPerformance.cpp. The result on my local machine was amazing:

InstanceOf performance(A->D)  : 3035 us
InstanceOf performance(A->C)  : 5030 us
InstanceOf performance(A->B)  : 5250 us
InstanceOf performance(A->A)  : 3021 us

DynamicCast performance(A->D) : 666903 us
DynamicCast performance(A->C) : 698567 us
DynamicCast performance(A->B) : 727368 us
DynamicCast performance(A->A) : 3098 us

If you are not reliant on multiple inheritance, are no opponent of good old C macros, RTTI and template metaprogramming and are not too lazy to add some small instructions to the classes of your class hierarchy, then this approach can boost your application a little bit with respect to its performance, if you often end up with checking the instance of a pointer. But use it with caution. There is no warranty for the correctness of this approach.

Note: All demos were compiled using clang (Apple LLVM version 9.0.0 (clang-900.0.39.2)) under macOS Sierra on a MacBook Pro Mid 2012.

Edit: I've also tested the performance on a Linux machine using gcc (Ubuntu 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609. On this platform the perfomance benefit was not so significant as on macOs with clang.

Output (without compiler optimization):

InstanceOf performance(A->D)  : 390768 us
InstanceOf performance(A->C)  : 333994 us
InstanceOf performance(A->B)  : 334596 us
InstanceOf performance(A->A)  : 300959 us

DynamicCast performance(A->D) : 331942 us
DynamicCast performance(A->C) : 303715 us
DynamicCast performance(A->B) : 400262 us
DynamicCast performance(A->A) : 324942 us

Output (with compiler optimization):

InstanceOf performance(A->D)  : 209501 us
InstanceOf performance(A->C)  : 208727 us
InstanceOf performance(A->B)  : 207815 us
InstanceOf performance(A->A)  : 197953 us

DynamicCast performance(A->D) : 259417 us
DynamicCast performance(A->C) : 256203 us
DynamicCast performance(A->B) : 261202 us
DynamicCast performance(A->A) : 193535 us

Get a list of dates between two dates using a function

This does exactly what you want, modified from Will's earlier post. No need for helper tables or loops.

WITH date_range (calc_date) AS (
    SELECT DATEADD(DAY, DATEDIFF(DAY, 0, '2010-01-13') - DATEDIFF(DAY, '2010-01-01', '2010-01-13'), 0)
        UNION ALL SELECT DATEADD(DAY, 1, calc_date)
            FROM date_range
            WHERE DATEADD(DAY, 1, calc_date) <= '2010-01-13')
SELECT calc_date
FROM date_range;

Confirm Password with jQuery Validate

Just a quick chime in here to hopefully help others... Especially with the newer version (since this is 2 years old)...

Instead of having some static fields defined in JS, you can also use the data-rule-* attributes. You can use built-in rules as well as custom rules.

See for built-in rules.


<p><label>Email: <input type="text" name="email" id="email" data-rule-email="true" required></label></p>
<p><label>Confirm Email: <input type="text" name="email" id="email_confirm" data-rule-email="true" data-rule-equalTo="#email" required></label></p>

Note the data-rule-* attributes.

How to give the background-image path in CSS?

you can also add inline css for adding image as a background as per below example

<div class="item active" style="background-image: url(../../foo.png);">

Can a Byte[] Array be written to a file in C#?

Based on the first sentence of the question: "I'm trying to write out a Byte[] array representing a complete file to a file."

The path of least resistance would be:

File.WriteAllBytes(string path, byte[] bytes)

Documented here:

System.IO.File.WriteAllBytes - MSDN


Oracle 9i+ (maybe 8i too) has FIRST/LAST aggregate functions, that make computation over groups of rows according to row's rank in group. Assuming all rows as one group, you'll get what you want without subqueries:

  keep (
      dense_rank first
      order by paym_date desc NULLS LAST
FROM user_payment
WHERE user_id=1

How do I check if a string contains another string in Objective-C?

For iOS 8.0+ and macOS 10.10+, you can use NSString's native containsString:.

For older versions of iOS and macOS, you can create your own (obsolete) category for NSString:

@interface NSString ( SubstringSearch )
    - (BOOL)containsString:(NSString *)substring;

// - - - - 

@implementation NSString ( SubstringSearch )

- (BOOL)containsString:(NSString *)substring
    NSRange range = [self rangeOfString : substring];
    BOOL found = ( range.location != NSNotFound );
    return found;


Note: Observe Daniel Galasko's comment below regarding naming

Does Visual Studio have code coverage for unit tests?

Toni's answer is very useful, but I thought a quick start for total beginners to test coverage assessment (like I am).

As already mentioned, Visual Studio Professional and Community Editions do not have built-in test coverage support. However, it can be obtained quite easily. I will write step-by-step configuration for use with NUnit tests within Visual Studion 2015 Professional.

  1. Install OpenCover NUGet component using NuGet interface

  2. Get OpenCoverUI extension. This can be installed directly from Visual Studio by using Tools -> Extensions and Updates

  3. Configure OpenCoverUI to use the appropriate executables, by accessing Tools -> Options -> OpenCover.UI Options -> General

NUnit Path: must point to the `nunit-console.exe file. This can be found only within NUnit 2.xx version, which can be downloaded from here.

OpenCover Path: this should point to the installed package, usually <solution path>\packages\OpenCover.4.6.519\tools\OpenCover.Console.exe

  1. Install ReportGenerator NUGet package

  2. Access OpenCover Test Explorer from OpenCover menu. Try discovering tests from there. If it fails, check Output windows for more details.

  3. Check OpenCover Results (within OpenCover menu) for more details. It will output details such as Code Coverage in a tree based view. You can also highlight code that is or is not covered (small icon in the top-left).

NOTE: as mentioned, OpenCoverUI does not support latest major version of NUnit (3.xx). However, if nothing specific to this version is used within tests, it will work with no problems, regardless of having installed NUnit 3.xx version.

This covers the quick start. As already mentioned in the comments, for more advanced configuration and automation check this article.

Getting the text from a drop-down box

function getValue(obj)
   // it will return the selected text
   // obj variable will contain the object of check box
   var text = obj.options[obj.selectedIndex].innerHTML ; 


HTML Snippet

 <asp:DropDownList ID="ddl" runat="server" CssClass="ComboXXX" 

How to sync with a remote Git repository?

For Linux:

git add * 
git commit -a --message "Initial Push All"
git push -u origin --all

java.lang.IllegalStateException: The specified child already has a parent

I have facing this issue many time. Please add following code for resolve this issue :

    public void onDestroyView() {
        if (view != null) {
            ViewGroup parentViewGroup = (ViewGroup) view.getParent();
            if (parentViewGroup != null) {


Whoops, looks like something went wrong. Laravel 5.0

in process of uploading env file to cpanel,

sometimes the dot is taken out and this may raised the error.

this solution worked for me.

go to your cpanel and rename env file to .env

JPA: how do I persist a String into a database field, type MYSQL Text

With @Lob I always end up with a LONGTEXTin MySQL.

To get TEXT I declare it that way (JPA 2.0):

@Column(columnDefinition = "TEXT")
private String text

Find this better, because I can directly choose which Text-Type the column will have in database.

For columnDefinition it is also good to read this.

EDIT: Please pay attention to Adam Siemions comment and check the database engine you are using, before applying columnDefinition = "TEXT".

Unicode character as bullet for list-item in CSS

To add a star use the Unicode character 22C6.

I added a space to make a little gap between the li and the star. The code for space is A0.

li:before {
    content: '\22C6\A0';

How to return part of string before a certain character?

In General a function to return string after substring is

function getStringAfterSubstring(parentString, substring) {_x000D_
    return parentString.substring(parentString.indexOf(substring) + substring.length)_x000D_
function getStringBeforeSubstring(parentString, substring) {_x000D_
    return parentString.substring(0, parentString.indexOf(substring))_x000D_
console.log(getStringAfterSubstring('abcxyz123uvw', '123'))_x000D_
console.log(getStringBeforeSubstring('abcxyz123uvw', '123'))

Intermediate language used in scalac?

The nearest equivalents would be icode and bcode as used by scalac, view Miguel Garcia's site on the Scalac optimiser for more information, here:

You might also consider Java bytecode itself to be your intermediate representation, given that bytecode is the ultimate output of scalac.

Or perhaps the true intermediate is something that the JIT produces before it finally outputs native instructions?

Ultimately though... There's no single place that you can point at an claim "there's the intermediate!". Scalac works in phases that successively change the abstract syntax tree, every single phase produces a new intermediate. The whole thing is like an onion, and it's very hard to try and pick out one layer as somehow being more significant than any other.

Multiplying Two Columns in SQL Server

In a query you can just do something like:

SELECT ColumnA * ColumnB FROM table


SELECT ColumnA - ColumnB FROM table

You can also create computed columns in your table where you can permanently use your formula.

How to remove an element from an array in Swift

As of Xcode 10+, and according to the WWDC 2018 session 223, "Embracing Algorithms," a good method going forward will be mutating func removeAll(where predicate: (Element) throws -> Bool) rethrows

Apple's example:

var phrase = "The rain in Spain stays mainly in the plain."
let vowels: Set<Character> = ["a", "e", "i", "o", "u"]

phrase.removeAll(where: { vowels.contains($0) })
// phrase == "Th rn n Spn stys mnly n th pln."

see Apple's Documentation

So in the OP's example, removing animals[2], "chimps":

var animals = ["cats", "dogs", "chimps", "moose"]
animals.removeAll(where: { $0 == "chimps" } )
// or animals.removeAll { $0 == "chimps" }

This method may be preferred because it scales well (linear vs quadratic), is readable and clean. Keep in mind that it only works in Xcode 10+, and as of writing this is in Beta.

How can I set a cookie in react?

Use vanilla js, example

document.cookie = `referral_key=hello;max-age=604800;`

Read more at:

Swipe to Delete and the "More" button (like in Mail app on iOS 7)

How to Implement

It looks like iOS 8 opens up this API. Hints of such functionality are present in Beta 2.

To get something working, implement the following two methods on your UITableView's delegate to get the desired effect (see gist for an example).

- tableView:editActionsForRowAtIndexPath:
- tableView:commitEditingStyle:forRowAtIndexPath:

Known Issues

The documentation says tableView:commitEditingStyle:forRowAtIndexPath is:

"Not called for edit actions using UITableViewRowAction - the action's handler will be invoked instead."

However, the swiping doesn't work without it. Even if the method stub is blank, it still needs it, for now. This is most obviously a bug in beta 2.


Original Answer:


Sample code with this working (In Swift):

The sample code contains this easy-to-follow method in MasterViewController.swift, and with just this method you get the behavior shown in the OP screenshot:

override func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [AnyObject]? {

    var moreRowAction = UITableViewRowAction(style: UITableViewRowActionStyle.Default, title: "More", handler:{action, indexpath in
    moreRowAction.backgroundColor = UIColor(red: 0.298, green: 0.851, blue: 0.3922, alpha: 1.0);

    var deleteRowAction = UITableViewRowAction(style: UITableViewRowActionStyle.Default, title: "Delete", handler:{action, indexpath in

    return [deleteRowAction, moreRowAction];

how to remove the bold from a headline?

You want font-weight, not text-decoration (along with suitable additional markup, such as <em> or <span>, so you can apply different styling to different parts of the heading)

HRESULT: 0x800A03EC on Worksheet.range

This could also be caused if you have no room on the partition you are saving to.

I checked my HD and foind it was maxed. Moving some un-needed files to a different partition resolved my problem.

Changing CSS style from ASP.NET code

If your div is an ASP.NET control with runat="server" then AviewAnew's answer should do it. If it's just an HTML div, then you'd probably want to use JavaScript. Can you add the actual div tag to your question?

Java verify void method calls n times with Mockito

The necessary method is Mockito#verify:

public static <T> T verify(T mock,
                           VerificationMode mode)

mock is your mocked object and mode is the VerificationMode that describes how the mock should be verified. Possible modes are:

verify(mock, times(5)).someMethod("was called five times");
verify(mock, never()).someMethod("was never called");
verify(mock, atLeastOnce()).someMethod("was called at least once");
verify(mock, atLeast(2)).someMethod("was called at least twice");
verify(mock, atMost(3)).someMethod("was called at most 3 times");
verify(mock, atLeast(0)).someMethod("was called any number of times"); // useful with captors
verify(mock, only()).someMethod("no other method has been called on the mock");

You'll need these static imports from the Mockito class in order to use the verify method and these verification modes:

import static org.mockito.Mockito.atLeast;
import static org.mockito.Mockito.atLeastOnce;
import static org.mockito.Mockito.atMost;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.only;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;

So in your case the correct syntax will be:

Mockito.verify(mock, times(4)).send()

This verifies that the method send was called 4 times on the mocked object. It will fail if it was called less or more than 4 times.

If you just want to check, if the method has been called once, then you don't need to pass a VerificationMode. A simple

verify(mock).someMethod("was called once");

would be enough. It internally uses verify(mock, times(1)).someMethod("was called once");.

It is possible to have multiple verification calls on the same mock to achieve a "between" verification. Mockito doesn't support something like this verify(mock, between(4,6)).someMethod("was called between 4 and 6 times");, but we can write

verify(mock, atLeast(4)).someMethod("was called at least four times ...");
verify(mock, atMost(6)).someMethod("... and not more than six times");

instead, to get the same behaviour. The bounds are included, so the test case is green when the method was called 4, 5 or 6 times.

SQL - The conversion of a varchar data type to a datetime data type resulted in an out-of-range value

You can make use of

Set dateformat <date-format> ;

in you sp function or stored procedure to get things done.

Using ls to list directories and their total sizes

It is important to note here that du gives you disk usage. Different machines can use different block sizes, so on one machine a block could be 4096 bytes and another machine could contain block sizes of 2048. If I put 10 1 byte files in a machine using 4096 bytes blocks and 10 1 byte file in a machine using 2048 bytes blocks, du -h would report ~40k and ~20k respectively.

If you want to know the size of all the files in a directory, for each directory you can do something like:

for x in ./*;
    if [[ -f "$x" ]]; then
        ls -al "$x"
done | awk '{print $6}' | awk '{s+=$1}END{print s}'

This would give you the total size of all the files in a directory.

Concatenate a vector of strings/character

Try using an empty collapse argument within the paste function:

paste(sdata, collapse = '')

Thanks to

belongs_to through associations

So you cant have the behavior that you want but you can do something that feels like it. You want to be able to do Choice.first.question

what I have done in the past is something like this

class Choice
  belongs_to :user
  belongs_to :answer
  validates_uniqueness_of :answer_id, :scope => [ :question_id, :user_id ]
  def question

this way the you can now call question on Choice

converting multiple columns from character to numeric format in r

I used this code to convert all columns to numeric except the first one:

    # check structure, row and column number with: glimpse(df)
    # convert to numeric e.g. from 2nd column to 10th column
    df <- df %>% 
     mutate_at(c(2:10), as.numeric)

Why use deflate instead of gzip for text files served by Apache?

if I remember correctly

  • gzip will compress a little more than deflate
  • deflate is more efficient

How to convert xml into array in php?

I liked this question and some answers was helpful to me, but i need to convert the xml to one domination array, so i will post my solution maybe someone need it later:

$xml = json_decode(json_encode((array)simplexml_load_string($xml)),1);
$finalItem = getChild($xml);

function getChild($xml, $finalItem = []){
    foreach($xml as $key=>$value){
            $finalItem[$key] = $value;
            $finalItem = getChild($value, $finalItem);
    return $finalItem;

PATH issue with pytest 'ImportError: No module named YadaYadaYada'

For me the problem was generated by Django along with tests directory. Removing solved the problem.

How to use 'hover' in CSS

Not an answer, but explanation of why your css is not matching HTML.

In css space is used as a separator to tell browser to look in children, so your css

a .hover :hover{

means "look for a element, then look for any descendants of it that have hover class and look of any descendants of those descendants that have hover state" and would match this markup

   <span class="hover">
         I will become underlined when you hover on me

If you want to match <a class="hover">I will become underlined when you hover on me</a> you should use a.hover:hover, which means "look for any a element with class hover and with hover state"

How do I debug "Error: spawn ENOENT" on node.js?

Windows solution: Replace spawn with node-cross-spawn. For instance like this at the beginning of your app.js:

(function() {
    var childProcess = require("child_process");
    childProcess.spawn = require('cross-spawn');

When to use CouchDB over MongoDB and vice versa

I summarize the answers found in that article:

MongoDB: Better querying, data storage in BSON (faster access), better data consistency, multiple collections

CouchDB: Better replication, with master to master replication and conflict resolution, data storage in JSON (human-readable, better access through REST services), querying through map-reduce.

So in conclusion, MongoDB is faster, CouchDB is safer.


The representation of if-elseif-else in EL using JSF

You can use EL if you want to work as IF:

<h:outputLabel value="#{row==10? '10' : '15'}"/>

Changing styles or classes:

style="#{test eq testMB.test? 'font-weight:bold' : 'font-weight:normal'}"

class="#{test eq testMB.test? 'divRred' : 'divGreen'}"

Responsive Image full screen and centered - maintain aspect ratio, not exceed window

After a lot of trial and error I found this solved my problems. This is used to display photos on TVs via a browser.

  • It Keeps the photos aspect ratio
  • Scales in vertical and horizontal
  • Centers vertically and horizontal
  • The only thing to watch for are really wide images. They do stretch to fill, but not by much, standard camera photos are not altered.

    Give it a try :)

*only tested in chrome so far


<div class="frame">
  <img src="image.jpg"/>


.frame {
  border: 1px solid red;

  min-height: 98%;
  max-height: 98%;
  min-width: 99%;
  max-width: 99%;

  text-align: center;
  margin: auto;
  position: absolute;
img {
  border: 1px solid blue;

  min-height: 98%;
  max-width: 99%;
  max-height: 98%;

  width: auto;
  height: auto;
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  margin: auto;

Python dict how to create key or append an element to key?

Use dict.setdefault():



        D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D

How do I set a path in Visual Studio?

Set the PATH variable, like you're doing. If you're running the program from the IDE, you can modify environment variables by adjusting the Debugging options in the project properties.

If the DLLs are named such that you don't need different paths for the different configuration types, you can add the path to the system PATH variable or to Visual Studio's global one in Tools | Options.

How to use execvp()

The first argument is the file you wish to execute, and the second argument is an array of null-terminated strings that represent the appropriate arguments to the file as specified in the man page.

For example:

char *cmd = "ls";
char *argv[3];
argv[0] = "ls";
argv[1] = "-la";
argv[2] = NULL;

execvp(cmd, argv); //This will run "ls -la" as if it were a command

Angular update object in object array

You can use for loop to find your element and update it:

  for (let i = 0; i < this.itemsArray.length; i++) {
      if(this.itemsArray[i].id =={
        this.users[i] = newItem;

Renaming files using node.js

For synchronous renaming use fs.renameSync

fs.renameSync('/path/to/Afghanistan.png', '/path/to/AF.png');

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

If you are using Google Cloud Messaging, then this issue will not be solved by simply changing your icon. For example, this will not work:

 Notification notification  = new Notification.Builder(this)

Even if ic_notification is transparant and white. It must be also defined in the Manifest meta data, like so:

  <meta-data android:name=""

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

Meta-data goes under the application tag, for reference.

Truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all()

You need to use bitwise operators | instead of or and & instead of and in pandas, you can't simply use the bool statements from python.

For much complex filtering create a mask and apply the mask on the dataframe.
Put all your query in the mask and apply it.

mask = (df["col1"]>=df["col2"]) & (stock["col1"]<=df["col2"])
df_new = df[mask]

How can I embed a YouTube video on GitHub wiki pages?

I created to simplify this. The usage is direct, from the examples above:

[![Everything Is AWESOME](]( "Everything Is AWESOME")

Will result in: example of usage of yt-embed

Just make a call to:[video_id] as the image instead of

Generate MD5 hash string with T-SQL


SUBSTRING(sys.fn_sqlvarbasetostr(HASHBYTES('MD5','your text')),3,32)

Is Python interpreted, or compiled, or both?

Python(the interpreter) is compiled.

Proof: It won't even compile your code if it contains syntax error.

Example 1:

print("This should print") 
a = 9/0 


This should print
Traceback (most recent call last):
  File "", line 2, in <module>
    a = 9/0
ZeroDivisionError: integer division or modulo by zero

Code gets compiled successfully. First line gets executed (print) second line throws ZeroDivisionError (run time error) .

Example 2:

print("This should not print")


  File "", line 2
SyntaxError: invalid syntax

Conclusion: If your code file contains SyntaxError nothing will execute as compilation fails.

How to split a string in Haskell?

If you use Data.Text, there is splitOn:

This is built in the Haskell Platform.

So for instance:

import qualified Data.Text as T
main = print $ T.splitOn (T.pack " ") (T.pack "this is a test")


{-# LANGUAGE OverloadedStrings #-}

import qualified Data.Text as T
main = print $ T.splitOn " " "this is a test"

Absolute Positioning & Text Alignment

position: absolute;
color: #ffffff;
font-weight: 500;
top: 0%;
left: 0%;
right: 0%;
text-align: center;

What is the difference between a symbolic link and a hard link?

I add on Nick's question: when are hard links useful or necessary? The only application that comes to my mind, in which symbolic links wouldn't do the job, is providing a copy of a system file in a chrooted environment.

How to use protractor to check if an element is visible?

I had a similar issue, in that I only wanted return elements that were visible in a page object. I found that I'm able to use the css :not. In the case of this issue, this should do you...


In the context of a page object, you can get ONLY those elements that are visible in this way as well. Eg. given a page with multiple items, where only some are visible, you can use:

this.visibileIcons = $$('i.icon:not(.ng-hide)'); 

This will return you all visible i.icons

How to convert JSON object to an Typescript array?

To convert any JSON to array, use the below code:

const usersJson: any[] = Array.of(res.json());

What is the effect of extern "C" in C++?

In every C++ program, all non-static functions are represented in the binary file as symbols. These symbols are special text strings that uniquely identify a function in the program.

In C, the symbol name is the same as the function name. This is possible because in C no two non-static functions can have the same name.

Because C++ allows overloading and has many features that C does not — like classes, member functions, exception specifications - it is not possible to simply use the function name as the symbol name. To solve that, C++ uses so-called name mangling, which transforms the function name and all the necessary information (like the number and size of the arguments) into some weird-looking string processed only by the compiler and linker.

So if you specify a function to be extern C, the compiler doesn't performs name mangling with it and it can be directly accessed using its symbol name as the function name.

This comes handy while using dlsym() and dlopen() for calling such functions.

android:drawableLeft margin and/or padding

Make your drawable resources.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="">
    <item android:state_checked="true">
        <inset android:drawable="@drawable/small_m" android:insetLeft="10dp" android:insetTop="10dp" />
        <inset android:drawable="@drawable/small_p" android:insetLeft="10dp" android:insetTop="10dp" />

Making a mocked method return an argument that was passed to it

You can create an Answer in Mockito. Let's assume, we have an interface named Application with a method myFunction.

public interface Application {
  public String myFunction(String abc);

Here is the test method with a Mockito answer:

public void testMyFunction() throws Exception {
  Application mock = mock(Application.class);
  when(mock.myFunction(anyString())).thenAnswer(new Answer<String>() {
    public String answer(InvocationOnMock invocation) throws Throwable {
      Object[] args = invocation.getArguments();
      return (String) args[0];


Since Mockito 1.9.5 and Java 8, you can also use a lambda expression:

when(myMock.myFunction(anyString())).thenAnswer(i -> i.getArguments()[0]);

Delete last commit in bitbucket

You can write the command also for Bitbucket as mentioned by Dustin:

git push -f origin HEAD^:master

Note: instead of master you can use any branch. And it deletes just push on Bitbucket.

To remove last commit locally in git use:

git reset --hard HEAD~1

How to fix System.NullReferenceException: Object reference not set to an instance of an object

I was getting this same error, but for me this was due to a method in a base class (in Project A) having the output type changed from a non-void type to void. A child class existed in Project B (which I didn't want used and had marked obsolete) that I missed when performing this update and hence started throwing this error.

1>CSC : error CS8104: An error occurred while writing the output file: System.NullReferenceException: Object reference not set to an instance of an object.

Original Code:

[Obsolete("Calling this method will throw an error")]
public override CompletionStatus Run()
    throw new CustomException("Run process not supported.");

Revised Code:

[Obsolete("Calling this method will throw an error")]
public override void Run()
    throw new CustomException("Run process not supported.");

Difference between adjustResize and adjustPan in android?

As doc says also keep in mind the correct value combination:

The setting must be one of the values listed in the following table, or a combination of one "state..." value plus one "adjust..." value. Setting multiple values in either group — multiple "state..." values, for example — has undefined results. Individual values are separated by a vertical bar (|). For example:

<activity android:windowSoftInputMode="stateVisible|adjustResize" . . . >

CSS Styling for a Button: Using <input type="button> instead of <button>

Float:left... Although I presume you want the input to be styled not the div?

.button input{
    font:2.4em Futura, ‘Century Gothic’, AppleGothic, sans-serif;
    background:url(overlay.png) repeat-x center #ffcc00;
    border:1px solid #ffcc00;
    border-bottom:1px solid #9f9f9f;
    -moz-box-shadow:inset 0 1px 0 rgba(255,255,255,0.5);
    -webkit-box-shadow:inset 0 1px 0 rgba(255,255,255,0.5);
    box-shadow:inset 0 1px 0 rgba(255,255,255,0.5);
.button input:hover{

Android Call an method from another class

You should use the following code :

Class2 cls2 = new Class2();

In case you don't want to create a new instance to call the method, you can decalre the method as static and then you can just call Class2.UpdateEmployee().

Oracle SQL - REGEXP_LIKE contains characters other than a-z or A-Z

Something like

select *
  from foo
 where regexp_like( col1, '[^[:alpha:]]' ) ;

should work

SQL> create table foo( col1 varchar2(100) );

Table created.

SQL> insert into foo values( 'abc' );

1 row created.

SQL> insert into foo values( 'abc123' );

1 row created.

SQL> insert into foo values( 'def' );

1 row created.

SQL> select *
  2    from foo
  3   where regexp_like( col1, '[^[:alpha:]]' ) ;


Can I use wget to check , but not download

Yes easy.

wget --spider

That will give you

Connecting to[]:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [text/html]
200 OK

Removing whitespace between HTML elements when using line breaks

Semantically speaking, wouldn't it be best to use an ordered or unordered list and then style it appropriately using CSS?

<ul id="[UL_ID]">
    <li><img src="[image1_url]" alt="img1" /></li>
    <li><img src="[image2_url]" alt="img2" /></li>
    <li><img src="[image3_url]" alt="img3" /></li>
    <li><img src="[image4_url]" alt="img4" /></li>
    <li><img src="[image5_url]" alt="img5" /></li>
    <li><img src="[image6_url]" alt="img6" /></li>

Using CSS, you'll be able to style this whatever way you want and remove the whitespace imbetween the books.

Can I change the color of Font Awesome's icon color?


<i class="icon-cog blackiconcolor">

css :

 .blackiconcolor {color:black;}

Using class will give you a free binding property which you can apply on any tag you require.

Simple PHP Pagination script

// Custom PHP MySQL Pagination Tutorial and Script
// You have to put your mysql connection data and alter the SQL queries(both queries)

mysql_connect("DATABASE_Host_Here","DATABASE_Username_Here","DATABASE_Password_Here") or die (mysql_error());
mysql_select_db("DATABASE_Name_Here") or die (mysql_error());
$sql = mysql_query("SELECT id, firstname, country FROM myTable ORDER BY id ASC");
//////////////////////////////////// Pagination Logic ////////////////////////////////////////////////////////////////////////
$nr = mysql_num_rows($sql); // Get total of Num rows from the database query
if (isset($_GET['pn'])) { // Get pn from URL vars if it is present
    $pn = preg_replace('#[^0-9]#i', '', $_GET['pn']); // filter everything but numbers for security(new)
    //$pn = ereg_replace("[^0-9]", "", $_GET['pn']); // filter everything but numbers for security(deprecated)
} else { // If the pn URL variable is not present force it to be value of page number 1
    $pn = 1;
//This is where we set how many database items to show on each page
$itemsPerPage = 10;
// Get the value of the last page in the pagination result set
$lastPage = ceil($nr / $itemsPerPage);
// Be sure URL variable $pn(page number) is no lower than page 1 and no higher than $lastpage
if ($pn < 1) { // If it is less than 1
    $pn = 1; // force if to be 1
} else if ($pn > $lastPage) { // if it is greater than $lastpage
    $pn = $lastPage; // force it to be $lastpage's value
// This creates the numbers to click in between the next and back buttons
// This section is explained well in the video that accompanies this script
$centerPages = "";
$sub1 = $pn - 1;
$sub2 = $pn - 2;
$add1 = $pn + 1;
$add2 = $pn + 2;
if ($pn == 1) {
    $centerPages .= '&nbsp; <span class="pagNumActive">' . $pn . '</span> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $add1 . '">' . $add1 . '</a> &nbsp;';
} else if ($pn == $lastPage) {
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $sub1 . '">' . $sub1 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <span class="pagNumActive">' . $pn . '</span> &nbsp;';
} else if ($pn > 2 && $pn < ($lastPage - 1)) {
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $sub2 . '">' . $sub2 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $sub1 . '">' . $sub1 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <span class="pagNumActive">' . $pn . '</span> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $add1 . '">' . $add1 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $add2 . '">' . $add2 . '</a> &nbsp;';
} else if ($pn > 1 && $pn < $lastPage) {
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $sub1 . '">' . $sub1 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <span class="pagNumActive">' . $pn . '</span> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $add1 . '">' . $add1 . '</a> &nbsp;';
// This line sets the "LIMIT" range... the 2 values we place to choose a range of rows from database in our query
$limit = 'LIMIT ' .($pn - 1) * $itemsPerPage .',' .$itemsPerPage;
// Now we are going to run the same query as above but this time add $limit onto the end of the SQL syntax
// $sql2 is what we will use to fuel our while loop statement below
$sql2 = mysql_query("SELECT id, firstname, country FROM myTable ORDER BY id ASC $limit");
//////////////////////////////// END Pagination Logic ////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////// Pagination Display Setup /////////////////////////////////////////////////////////////////////
$paginationDisplay = ""; // Initialize the pagination output variable
// This code runs only if the last page variable is ot equal to 1, if it is only 1 page we require no paginated links to display
if ($lastPage != "1"){
    // This shows the user what page they are on, and the total number of pages
    $paginationDisplay .= 'Page <strong>' . $pn . '</strong> of ' . $lastPage. '&nbsp;  &nbsp;  &nbsp; ';
    // If we are not on page 1 we can place the Back button
    if ($pn != 1) {
        $previous = $pn - 1;
        $paginationDisplay .=  '&nbsp;  <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $previous . '"> Back</a> ';
    // Lay in the clickable numbers display here between the Back and Next links
    $paginationDisplay .= '<span class="paginationNumbers">' . $centerPages . '</span>';
    // If we are not on the very last page we can place the Next button
    if ($pn != $lastPage) {
        $nextPage = $pn + 1;
        $paginationDisplay .=  '&nbsp;  <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $nextPage . '"> Next</a> ';
///////////////////////////////////// END Pagination Display Setup ///////////////////////////////////////////////////////////////////////////
// Build the Output Section Here
$outputList = '';
while($row = mysql_fetch_array($sql2)){

    $id = $row["id"];
    $firstname = $row["firstname"];
    $country = $row["country"];

    $outputList .= '<h1>' . $firstname . '</h1><h2>' . $country . ' </h2><hr />';

} // close while loop
<title>Simple Pagination</title>
   <div style="margin-left:64px; margin-right:64px;">
     <h2>Total Items: <?php echo $nr; ?></h2>
      <div style="margin-left:58px; margin-right:58px; padding:6px; background-color:#FFF; border:#999 1px solid;"><?php echo $paginationDisplay; ?></div>
      <div style="margin-left:64px; margin-right:64px;"><?php print "$outputList"; ?></div>
      <div style="margin-left:58px; margin-right:58px; padding:6px; background-color:#FFF; border:#999 1px solid;"><?php echo $paginationDisplay; ?></div>

How to line-break from css, without using <br />?

You can add a lot of padding and force text to be split to new line, for example

    padding-right: 50%;

Worked fine for me in a situation with responsive design, where only within a certain width range it was needed for text to be split.

Cross-browser window resize event - JavaScript / jQuery

Here is the non-jQuery way of tapping into the resize event:

window.addEventListener('resize', function(event){
  // do stuff here

It works on all modern browsers. It does not throttle anything for you. Here is an example of it in action.

Getting the parameters of a running JVM

If you can do this in java, try:




RuntimeMXBean runtimeMXBean = ManagementFactory.getRuntimeMXBean();
List<String> jvmArgs = runtimeMXBean.getInputArguments();
for (String arg : jvmArgs) {

Return date as ddmmyyyy in SQL Server

Try this:

SELECT CONVERT(DATE, STUFF(STUFF('01012020', 5, 0, '-'), 3, 0, '-'), 103);

It works with SQL Server 2016.

Deprecation warning in Moment.js - Not in a recognized ISO format

I have similar issue faced and solve with following solution: my date format is: 'Fri Dec 11 2020 05:00:00 GMT+0500 (Pakistan Standard Time)'

let currentDate = moment(new Date('Fri Dec 11 2020 05:00:00 GMT+0500 (Pakistan Standard Time)').format('DD-MM-YYYY'); // 'Fri Dec 11 2020 05:00:00 GMT+0500 (Pakistan Standard Time)'

let output=(moment(currentDate).isSameOrAfter('07-12-2020'));

How to copy a file from one directory to another using PHP?

You could use the rename() function :

rename('foo/test.php', 'bar/test.php');

This however will move the file not copy

Inserting HTML elements with JavaScript

Instead of directly messing with innerHTML it might be better to create a fragment and then insert that:

function create(htmlStr) {
    var frag = document.createDocumentFragment(),
        temp = document.createElement('div');
    temp.innerHTML = htmlStr;
    while (temp.firstChild) {
    return frag;

var fragment = create('<div>Hello!</div><p>...</p>');
// You can use native DOM methods to insert the fragment:
document.body.insertBefore(fragment, document.body.childNodes[0]);


  1. You can use native DOM methods for insertion such as insertBefore, appendChild etc.
  2. You have access to the actual DOM nodes before they're inserted; you can access the fragment's childNodes object.
  3. Using document fragments is very quick; faster than creating elements outside of the DOM and in certain situations faster than innerHTML.

Even though innerHTML is used within the function, it's all happening outside of the DOM so it's much faster than you'd think...

How to copy multiple files in one layer using a Dockerfile?


COPY  package.json gulpfile.js __BUILD_NUMBER ./

from the doc

If multiple resources are specified, either directly or due to the use of a wildcard, then must be a directory, and it must end with a slash /.

How to change XAMPP apache server port?

I had problem too. I switced Port but couldn't start on 8012.

Skype was involved becouse it had the same port - 80. And it couldn't let apache change it's port.

So just restart computer and Before turning on any other programs Open xampp first change port let's say from 80 to 8000 or 8012 on these lines in httpd.conf

Listen 80
ServerName localhost:80

Restart xampp, Start apache, check localhost.

Disable Chrome strict MIME type checking

The server should respond with the correct MIME Type for JSONP application/javascript and your request should tell jQuery you are loading JSONP dataType: 'jsonp'

Please see this answer for further details ! You can also have a look a this one as it explains why loading .js file with text/plain won't work.

What is the most elegant way to check if all values in a boolean array are true?

In Java 8+, you can create an IntStream in the range of 0 to myArray.length and check that all values are true in the corresponding (primitive) array with something like,

return IntStream.range(0, myArray.length).allMatch(i -> myArray[i]);

iPhone - Get Position of UIView within entire UIWindow

Swift 5+:

let globalPoint = aView.superview?.convert(aView.frame.origin, to: nil)

How do browser cookie domains work?

The last (third to be exactly) RFC for this issue is RFC-6265 (Obsoletes RFC-2965 that in turn obsoletes RFC-2109).

According to it if the server omits the Domain attribute, the user agent will return the cookie only to the origin server (the server on which a given resource resides). But it's also warning that some existing user agents treat an absent Domain attribute as if the Domain attribute were present and contained the current host name (For example, if returns a Set-Cookie header without a Domain attribute, these user agents will erroneously send the cookie to as well).

When the Domain attribute have been specified, it will be treated as complete domain name (if there is the leading dot in attribute it will be ignored). Server should match the domain specified in attribute (have exactly the same domain name or to be a subdomain of it) to get this cookie. More accurately it specified here.

So, for example:

  • cookie attribute is equivalent to
  • cookies with such Domain attributes will be available for and
  • cookies with such Domain attributes will be not available for
  • specifying cookie attribute like will close the way for

PS: trailing comma in Domain attribute will cause the user agent to ignore the attribute =(

What is JavaScript's highest integer value that a number can go to without losing precision?

Scato wrotes:

anything you want to use for bitwise operations must be between 0x80000000 (-2147483648 or -2^31) and 0x7fffffff (2147483647 or 2^31 - 1).

the console will tell you that 0x80000000 equals +2147483648, but 0x80000000 & 0x80000000 equals -2147483648

Hex-Decimals are unsigned positive values, so 0x80000000 = 2147483648 - thats mathematically correct. If you want to make it a signed value you have to right shift: 0x80000000 >> 0 = -2147483648. You can write 1 << 31 instead, too.

reading from stdin in c++

You have not defined the variable input_line.

Add this:

string input_line;

And add this include.

#include <string>

Here is the full example. I also removed the semi-colon after the while loop, and you should have getline inside the while to properly detect the end of the stream.

#include <iostream>
#include <string>

int main() {
    for (std::string line; std::getline(std::cin, line);) {
        std::cout << line << std::endl;
    return 0;

Download file and automatically save it to folder

A much simpler solution would be to download the file using Chrome. In this manner you don't have to manually click on the save button.

using System;
using System.Diagnostics;
using System.ComponentModel;

namespace MyProcessSample
    class MyProcess
        public static void Main()
            Process myProcess = new Process();

Building a complete online payment gateway like Paypal

Big task, chances are you shouldn't reinvent the wheel rather using an existing wheel (such as paypal).

However, if you insist on continuing. Start small, you can use a credit card processing facility (Moneris, Authorize.NET) to process credit cards. Most providers have an API you can use. Be wary that you may need to use different providers depending on the card type (Discover, Visa, Amex, Mastercard) and Country (USA, Canada, UK). So build it so that you can communicate with multiple credit card processing APIs.

Security is essential if you are storing credit cards and payment details. Ensure that you are encrypting things properly.

Again, don't reinvent the wheel. You are better off using an existing provider and focussing your development attention on solving an problem that can't easily be purchase.

Select second last element with css

Note: Posted this answer because OP later stated in comments that they need to select the last two elements, not just the second to last one.

The :nth-child CSS3 selector is in fact more capable than you ever imagined!

For example, this will select the last 2 elements of #container:

#container :nth-last-child(-n+2) {}

But this is just the beginning of a beautiful friendship.

#container :nth-last-child(-n+2) {
  background-color: cyan;
<div id="container">
 <div>SELECT THIS</div>
 <div>SELECT THIS</div>

Use JSTL forEach loop's varStatus as an ID

The variable set by varStatus is a LoopTagStatus object, not an int. Use:

<div id="divIDNo${theCount.index}">

To clarify:

  • ${theCount.index} starts counting at 0 unless you've set the begin attribute
  • ${theCount.count} starts counting at 1

HTML/CSS - Adding an Icon to a button

Here's what you can do using font-awesome library.

button.btn.add::before {_x000D_
  font-family: fontAwesome;_x000D_
  content: "\f067\00a0";_x000D_
button.btn.edit::before {_x000D_
  font-family: fontAwesome;_x000D_
  content: "\f044\00a0";_x000D_
_x000D_ {_x000D_
  font-family: fontAwesome;_x000D_
  content: "\f00c\00a0";_x000D_
button.btn.cancel::before {_x000D_
  font-family: fontAwesome;_x000D_
  content: "\f00d\00a0";_x000D_
<script src=""></script>_x000D_
<script src=""></script>_x000D_
<link href="" rel="stylesheet"/>_x000D_
<link href="" rel="stylesheet"/>_x000D_
<!--FA unicodes here:>_x000D_
<h4>Buttons with text</h4>_x000D_
<button class="btn cancel btn-default">Close</button>_x000D_
<button class="btn add btn-primary">Add</button>_x000D_
<button class="btn add btn-success">Insert</button>_x000D_
<button class="btn save btn-primary">Save</button>_x000D_
<button class="btn save btn-warning">Submit Changes</button>_x000D_
<button class="btn cancel btn-link">Delete</button>_x000D_
<button class="btn edit btn-info">Edit</button>_x000D_
<button class="btn edit btn-danger">Modify</button>_x000D_
<h4>Buttons without text</h4>_x000D_
<button class="btn edit btn-primary" />_x000D_
<button class="btn cancel btn-danger" />_x000D_
<button class="btn add btn-info" />_x000D_
<button class="btn save btn-success" />_x000D_
<button class="btn edit btn-link"/>_x000D_
<button class="btn cancel btn-link"/>

Fiddle here.

How to force file download with PHP

You can stream download too which will consume significantly less resource. example:

$readableStream = fopen('', 'rb');
$writableStream = fopen('php://output', 'wb');

header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename=""');
stream_copy_to_stream($readableStream, $writableStream);

In the above example, I am downloading a (which was actually the android studio zip on my local machine). php://output is a write-only stream (generally used by echo or print). after that, you just need to set the required headers and call stream_copy_to_stream(source, destination). stream_copy_to_stream() method acts as a pipe which takes the input from the source stream (read stream) and pipes it to the destination stream (write stream) and it also avoid the issue of allowed memory exhausted so you can actually download files that are bigger than your PHP memory_limit.

How do I view 'git diff' output with my preferred diff tool/ viewer?

The following can be gleaned from the other answers here, but for me it's difficult, (too much information), so here's the 'just type it in' answer for tkdiff:

git difftool --tool=tkdiff <path to the file to be diffed>

You can substitute the executable name of your favorite diffing tool for tkdiff. As long as (e.g. tkdiff), (or your favorite diffing tool) is in your PATH, it will be launched.

PHP: How to handle <![CDATA[ with SimpleXMLElement?

When to use LIBXML_NOCDATA ?

I add the issue when transforming XML to JSON.

$xml = simplexml_load_string("<foo><content><![CDATA[Hello, world!]]></content></foo>");
echo json_encode($xml, true); 
/* prints
     "content": {}

When accessing the SimpleXMLElement object, It gets the CDATA :

$xml = simplexml_load_string("<foo><content><![CDATA[Hello, world!]]></content></foo>");
echo $xml->content; 
/* prints
   Hello, world!

I makes sense to use LIBXML_NOCDATA because json_encode don't access the SimpleXMLElement to trigger the string casting feature, I'm guessing a __toString() equivalent.

$xml = simplexml_load_string("<foo><content><![CDATA[Hello, world!]]></content></foo>", null, LIBXML_NOCDATA);
echo json_encode($xml);
   "content": "Hello, world!"

Dataframe to Excel sheet

I tested the previous answers found here: Assuming that we want the other four sheets to remain, the previous answers here did not work, because the other four sheets were deleted. In case we want them to remain use xlwings:

import xlwings as xw
import pandas as pd

filename = "test.xlsx"

df = pd.DataFrame([
    ("a", 1, 8, 3),
    ("b", 1, 2, 5),
    ("c", 3, 4, 6),
    ], columns=['one', 'two', 'three', "four"])

app = xw.App(visible=False)
wb = xw.Book(filename)
ws = wb.sheets["Sheet5"]

ws["A1"].options(pd.DataFrame, header=1, index=False, expand='table').value = df

# If formatting of column names and index is needed as xlsxwriter does it, 
# the following lines will do it (if the dataframe is not multiindex).
ws["A1"].expand("right").api.Font.Bold = True
ws["A1"].expand("down").api.Font.Bold = True
ws["A1"].expand("right").api.Borders.Weight = 2
ws["A1"].expand("down").api.Borders.Weight = 2

failed to find target with hash string android-23

Following these reccomended directions seemed to work:

Hint: Open the SDK manager by running: /path/to/android/tools/android

You will require: 1. "SDK Platform" for android-23 2. "Android SDK Platform-tools (latest) 3. "Android SDK Build-tools" (latest)

Bootstrap 3 Flush footer to bottom. not fixed

For Bootstrap:

<div class="navbar-fixed-bottom row-fluid">
  <div class="navbar-inner">
    <div class="container">

Label word wrapping

You can use a TextBox and set multiline to true and canEdit to false .

git submodule tracking latest

Edit (2020.12.28): GitHub change default master branch to main branch since October 2020. See

Update March 2013

Git 1.8.2 added the possibility to track branches.

"git submodule" started learning a new mode to integrate with the tip of the remote branch (as opposed to integrating with the commit recorded in the superproject's gitlink).

# add submodule to track master branch
git submodule add -b master [URL to Git repo];

# update your submodule
git submodule update --remote 

If you had a submodule already present you now wish would track a branch, see "how to make an existing submodule track a branch".

Also see Vogella's tutorial on submodules for general information on submodules.


git submodule add -b . [URL to Git repo];

See git submodule man page:

A special value of . is used to indicate that the name of the branch in the submodule should be the same name as the current branch in the current repository.

See commit b928922727d6691a3bdc28160f93f25712c565f6:

submodule add: If --branch is given, record it in .gitmodules

This allows you to easily record a submodule.<name>.branch option in .gitmodules when you add a new submodule. With this patch,

$ git submodule add -b <branch> <repository> [<path>]
$ git config -f .gitmodules submodule.<path>.branch <branch>

reduces to

$ git submodule add -b <branch> <repository> [<path>]

This means that future calls to

$ git submodule update --remote ...

will get updates from the same branch that you used to initialize the submodule, which is usually what you want.

Signed-off-by: W. Trevor King [email protected]

Original answer (February 2012):

A submodule is a single commit referenced by a parent repo.
Since it is a Git repo on its own, the "history of all commits" is accessible through a git log within that submodule.

So for a parent to track automatically the latest commit of a given branch of a submodule, it would need to:

  • cd in the submodule
  • git fetch/pull to make sure it has the latest commits on the right branch
  • cd back in the parent repo
  • add and commit in order to record the new commit of the submodule.

gitslave (that you already looked at) seems to be the best fit, including for the commit operation.

It is a little annoying to make changes to the submodule due to the requirement to check out onto the correct submodule branch, make the change, commit, and then go into the superproject and commit the commit (or at least record the new location of the submodule).

Other alternatives are detailed here.

Javascript geocoding from address to latitude and longitude numbers not working

The script tag to the api has changed recently. Use something like this to query the Geocoding API and get the JSON object back

<script type="text/javascript" src=""></script>

The address could be something like

1600+Amphitheatre+Parkway,+Mountain+View,+CA (URI Encoded; you should Google it. Very useful)

or simply

1600 Amphitheatre Parkway, Mountain View, CA

By entering this address,+Mountain+View,+CA&key=YOUR_API_KEY inside the browser, along with my API Key, I get back a JSON object which contains the Latitude & Longitude for the city of Moutain view, CA.

{"results" : [
     "address_components" : [
           "long_name" : "1600",
           "short_name" : "1600",
           "types" : [ "street_number" ]
           "long_name" : "Amphitheatre Parkway",
           "short_name" : "Amphitheatre Pkwy",
           "types" : [ "route" ]
           "long_name" : "Mountain View",
           "short_name" : "Mountain View",
           "types" : [ "locality", "political" ]
           "long_name" : "Santa Clara County",
           "short_name" : "Santa Clara County",
           "types" : [ "administrative_area_level_2", "political" ]
           "long_name" : "California",
           "short_name" : "CA",
           "types" : [ "administrative_area_level_1", "political" ]
           "long_name" : "United States",
           "short_name" : "US",
           "types" : [ "country", "political" ]
           "long_name" : "94043",
           "short_name" : "94043",
           "types" : [ "postal_code" ]
     "formatted_address" : "1600 Amphitheatre Pkwy, Mountain View, CA 94043, USA",
     "geometry" : {
        "location" : {
           "lat" : 37.4222556,
           "lng" : -122.0838589
        "location_type" : "ROOFTOP",
        "viewport" : {
           "northeast" : {
              "lat" : 37.4236045802915,
              "lng" : -122.0825099197085
           "southwest" : {
              "lat" : 37.4209066197085,
              "lng" : -122.0852078802915
     "place_id" : "ChIJ2eUgeAK6j4ARbn5u_wAGqWA",
     "types" : [ "street_address" ]
  }],"status" : "OK"}

Web Frameworks such like AngularJS allow us to perform these queries with ease.

Convert Python program to C/C++ code?

If the C variant needs x hours less, then I'd invest that time in letting the algorithms run longer/again

"invest" isn't the right word here.

  1. Build a working implementation in Python. You'll finish this long before you'd finish a C version.

  2. Measure performance with the Python profiler. Fix any problems you find. Change data structures and algorithms as necessary to really do this properly. You'll finish this long before you finish the first version in C.

  3. If it's still too slow, manually translate the well-designed and carefully constructed Python into C.

    Because of the way hindsight works, doing the second version from existing Python (with existing unit tests, and with existing profiling data) will still be faster than trying to do the C code from scratch.

This quote is important.

Thompson's Rule for First-Time Telescope Makers
It is faster to make a four-inch mirror and then a six-inch mirror than to make a six-inch mirror.

Bill McKeenan
Wang Institute

Intellij idea subversion checkout error: `Cannot run program "svn"`

In IntelliJ Idea 2017.1 you can use the embedded SVN client that sadly is not enabled by default. Here's how you can activate it.

1) Open IntelliJ Idea

2) Menu Help > Find Actions...

enter image description here

3) Type subversion to gain access to the subversion related settings. Choose the item Subversion Settings as highlighted in the following picture.

enter image description here

4) Finally, be sure to uncheck the option Use command line client.

enter image description here

From now on, in the current project, you'll use the embedded subversion.

How do you round a number to two decimal places in C#?

Personally I never round anything. Keep it as resolute as possible, since rounding is a bit of a red herring in CS anyway. But you do want to format data for your users, and to that end, I find that string.Format("{0:0.00}", number) is a good approach.

How to break out of while loop in Python?

while True:
    print('Your score is so far '+str(myScore)+'.')
    print("Would you like to roll or quit?")
    if ans=='R':
        R=random.randint(1, 8)
        print("You rolled a "+str(R)+".")
        print("Now I'll see if I can break your score...")
        ans = False

How to count number of records per day?

SELECT count(*), dateadded FROM Responses
WHERE DateAdded >=dateadd(day,datediff(day,0,GetDate())- 7,0)
group by dateadded


This will give you a count of records for each dateadded value. Don't make the mistake of adding more columns to the select, expecting to get just one count per day. The group by clause will give you a row for every unique instance of the columns listed.