Programs & Examples On #Launcher

A launcher is a program that stores locations of applications to aid users in starting them.

How to make a launcher

They're examples provided by the Android team, if you've already loaded Samples, you can import Home screen replacement sample by following these steps.

File > New > Other >Android > Android Sample Project > Android x.x > Home > Finish

But if you do not have samples loaded, then download it using the below steps

Windows > Android SDK Manager > chooses "Sample for SDK" for SDK you need it > Install package > Accept License > Install

How do you change the launcher logo of an app in Android Studio?

To quickly create a new set of icons and change the launcher icon in Android Studio, you can:

  1. Use this tool: to upload your preferred image or icon (your source file). The tool then automatically creates a set of icons in all the different resolutions for the ic_launcher.png.

  2. Download the zip-file created by the tool, extract everything (which will create a folder structure for all the different resolutions) and then replace all the icons inside your project res folder: <AndroidStudioProjectPath>\app\src\main\res

Launch Minecraft from command line - username and password as prefix

To run Minecraft with Forge (change C:\Users\nov11\AppData\Roaming/.minecraft/to your MineCraft path :) [Just for people who are a bit too lazy to search on Google...] Special thanks to ammarx for his TagAPI_3 (Github) which was used to create this command. Arguments are separated line by line to make it easier to find useful ones.


Just when other solutions don't work. accessToken and uuid can be acquired from Mojang Servers, check other anwsers for details.

Edit (26.11.2018): I've also created Launcher Framework in C# (.NET Framework 3.5), which you can also check to see how launcher should work Available Here

How to make div appear in front of another?

Upper div use higher z-index and lower div use lower z-index then use absolute/fixed/relative position

Get Application Directory

If you're trying to get access to a file, try the openFileOutput() and openFileInput() methods as described here. They automatically open input/output streams to the specified file in internal memory. This allows you to bypass the directory and File objects altogether which is a pretty clean solution.

Using HttpClient and HttpPost in Android with post parameters

I've just checked and i have the same code as you and it works perferctly. The only difference is how i fill my List for the params :

I use a : ArrayList<BasicNameValuePair> params

and fill it this way :

 params.add(new BasicNameValuePair("apikey", apikey);

I do not use any JSONObject to send params to the webservices.

Are you obliged to use the JSONObject ?

Reference requirements.txt for the install_requires kwarg in setuptools file

I created a reusable function for this. It actually parses an entire directory of requirements files and sets them to extras_require.

Latest always available here:

import glob
import itertools
import os

# This is getting ridiculous
    from pip._internal.req import parse_requirements
    from import PipSession
except ImportError:
        from pip._internal.req import parse_requirements
        from import PipSession
    except ImportError:
        from pip.req import parse_requirements
        from import PipSession

def setup_requirements(
            'requirements.txt', 'requirements/*.txt', 'requirements/*.pip'
    Parse a glob of requirements and return a dictionary of setup() options.
    Create a dictionary that holds your options to setup() and update it using this.
    Pass that as kwargs into setup(), viola

    Any files that are not a standard option name (ie install, tests, setup) are added to extras_require with their
    basename minus ext. An extra key is added to extras_require: 'all', that contains all distinct reqs combined.

    Keep in mind all literally contains `all` packages in your extras.
    This means if you have conflicting packages across your extras, then you're going to have a bad time.
    (don't use all in these cases.)

    If you're running this for a Docker build, set `combine=True`.
    This will set `install_requires` to all distinct reqs combined.


    >>> import setuptools
    >>> _conf = dict(
    ...     name='mainline',
    ...     version='0.0.1',
    ...     description='Mainline',
    ...     author='Trevor Joynson <[email protected],io>',
    ...     url='',
    ...     namespace_packages=['mainline'],
    ...     packages=setuptools.find_packages(),
    ...     zip_safe=False,
    ...     include_package_data=True,
    ... )
    >>> _conf.update(setup_requirements())
    >>> # setuptools.setup(**_conf)

    :param str pattern: Glob pattern to find requirements files
    :param bool combine: Set True to set install_requires to extras_require['all']
    :return dict: Dictionary of parsed setup() options
    session = PipSession()

    # Handle setuptools insanity
    key_map = {
        'requirements': 'install_requires',
        'install': 'install_requires',
        'tests': 'tests_require',
        'setup': 'setup_requires',
    ret = {v: set() for v in key_map.values()}
    extras = ret['extras_require'] = {}
    all_reqs = set()

    files = [glob.glob(pat) for pat in patterns]
    files = itertools.chain(*files)

    for full_fn in files:
        # Parse
        reqs = {
            for r in parse_requirements(full_fn, session=session)
            # Must match env marker, eg:
            #   yarl ; python_version >= '3.0'
            if r.match_markers()

        # Add in the right section
        fn = os.path.basename(full_fn)
        barefn, _ = os.path.splitext(fn)
        key = key_map.get(barefn)

        if key:
            extras[key] = reqs

        extras[barefn] = reqs

    if 'all' not in extras:
        extras['all'] = list(all_reqs)

    if combine:
        extras['install'] = ret['install_requires']
        ret['install_requires'] = list(all_reqs)

    def _listify(dikt):
        ret = {}

        for k, v in dikt.items():
            if isinstance(v, set):
                v = list(v)
            elif isinstance(v, dict):
                v = _listify(v)
            ret[k] = v

        return ret

    ret = _listify(ret)

    return ret

__all__ = ['setup_requirements']

if __name__ == '__main__':
    reqs = setup_requirements()

How to change content on hover

<span class="label"></span>

iOS: Multi-line UILabel in Auto Layout

One way to do this... As text length increases try to change (decrease) the fontsize of the label text using

Label.adjustsFontSizeToFitWidth = YES;

Preventing iframe caching in browser

I also had this problem in 2016 with iOS Safari. What seemed to work for me was giving a GET-parameter to the iframe src and a value for it like this

<iframe width="60%" src="../other/url?cachebust=1" allowfullscreen></iframe>

The Response content must be a string or object implementing __toString(), "boolean" given after move to psql

You can use json_decode(Your variable Name):


I was getting value from Model.where a column has value like this way


so access this value form model. you have to use this code.

$dayTimeListObject = json_decode($settingAttendance->bio_attendance_day_time,1);

 foreach ( $dayTimeListObject['dayList'] as $dayListArr)
     foreach ( $dayListArr['day'] as $dayIndex)
         if( $dayIndex == Date('w',strtotime('2020-02-11')))
             $dayTimeList= $dayListArr['time'];

 return $dayTimeList[2]['out_time'] ;

You can also define caste in your Model file.

 protected $casts = [
    'your-column-name' => 'json'

so after this no need of this line .

$dayTimeListObject = json_decode($settingAttendance->bio_attendance_day_time,1);

you can directly access this code.


Why are arrays of references illegal?

References are not objects. They don't have storage of their own, they just reference existing objects. For this reason it doesn't make sense to have arrays of references.

If you want a light-weight object that references another object then you can use a pointer. You will only be able to use a struct with a reference member as objects in arrays if you provide explicit initialization for all the reference members for all struct instances. References cannot be default initalized.

Edit: As jia3ep notes, in the standard section on declarations there is an explicit prohibition on arrays of references.

How to create a DOM node as an object?

Try this:

var div = $('<div></div>').addClass('bar').text('bla');
var li = $('<li></li>').attr('id', '1234');


Obviously, it doesn't make sense to append a li to the body directly. Basically, the trick is to construct the DOM elementr tree with $('your html here'). I suggest to use CSS modifiers (.text(), .addClass() etc) as opposed to making jquery parse raw HTML, it will make it much easier to change things later.

How to find the type of an object in Go?

The Go reflection package has methods for inspecting the type of variables.

The following snippet will print out the reflection type of a string, integer and float.

package main

import (

func main() {

    tst := "string"
    tst2 := 10
    tst3 := 1.2




Hello, playground

see: to view it in action.

More documentation here:

HTML Agility pack - parsing tables

I know this is a pretty old question but this was my solution that helped with visualizing the table so you can create a class structure. This is also using the HTML Agility Pack

HtmlDocument doc = new HtmlDocument();
doc.LoadHtml(@"<html><body><p><table id=""foo""><tr><th>hello</th></tr><tr><td>world</td></tr></table></body></html>");
var table = doc.DocumentNode.SelectSingleNode("//table");
var tableRows = table.SelectNodes("tr");
var columns = tableRows[0].SelectNodes("th/text()");
for (int i = 1; i < tableRows.Count; i++)
    for (int e = 0; e < columns.Count; e++)
        var value = tableRows[i].SelectSingleNode($"td[{e + 1}]");
        Console.Write(columns[e].InnerText + ":" + value.InnerText);

Open link in new tab or window

You should add the target="_blank" and rel="noopener noreferrer" in the anchor tag.

For example:

<a target="_blank" rel="noopener noreferrer" href="http://your_url_here.html">Link</a>

Adding rel="noopener noreferrer" is not mandatory, but it's a recommended security measure. More information can be found in the links below.


ProgressDialog in AsyncTask

A couple of days ago I found a very nice solution of this problem. Read about it here. In two words Mike created a AsyncTaskManager that mediates ProgressDialog and AsyncTask. It's very easy to use this solution. You just need to include in your project several interfaces and several classes and in your activity write some simple code and nest your new AsyncTask from BaseTask. I also advice you to read comments because there are some useful tips.

Key Value Pair List

Using one of the subsets method in this question

var list = new List<KeyValuePair<string, int>>() { 
    new KeyValuePair<string, int>("A", 1),
    new KeyValuePair<string, int>("B", 0),
    new KeyValuePair<string, int>("C", 0),
    new KeyValuePair<string, int>("D", 2),
    new KeyValuePair<string, int>("E", 8),

int input = 11;
var items = SubSets(list).FirstOrDefault(x => x.Sum(y => y.Value)==input);


a full console application:

using System;
using System.Collections.Generic;
using System.Linq;

namespace ConsoleApplication1
    class Program
        static void Main(string[] args)
            var list = new List<KeyValuePair<string, int>>() { 
                new KeyValuePair<string, int>("A", 1),
                new KeyValuePair<string, int>("B", 2),
                new KeyValuePair<string, int>("C", 3),
                new KeyValuePair<string, int>("D", 4),
                new KeyValuePair<string, int>("E", 5),
                new KeyValuePair<string, int>("F", 6),

            int input = 12;
            var alternatives = list.SubSets().Where(x => x.Sum(y => y.Value) == input);

            foreach (var res in alternatives)
                Console.WriteLine(String.Join(",", res.Select(x => x.Key)));

    public static class Extenions
        public static IEnumerable<IEnumerable<T>> SubSets<T>(this IEnumerable<T> enumerable)
            List<T> list = enumerable.ToList();
            ulong upper = (ulong)1 << list.Count;

            for (ulong i = 0; i < upper; i++)
                List<T> l = new List<T>(list.Count);
                for (int j = 0; j < sizeof(ulong) * 8; j++)
                    if (((ulong)1 << j) >= upper) break;

                    if (((i >> j) & 1) == 1)

                yield return l;

Simulating ENTER keypress in bash script

You could make use of expect (man expect comes with examples).

Meaning of numbers in "col-md-4"," col-xs-1", "col-lg-2" in Bootstrap

Here you go

col-lg-2 : if the screen is large (lg) then this component will take space of 2 elements considering entire row can fit 12 elements ( so you will see that on large screen this component takes 16% space of a row)

col-lg-6 : if the screen is large (lg) then this component will take space of 6 elements considering entire row can fit 12 elements -- when applied you will see that the component has taken half the available space in the row.

Above rule is only applied when the screen is large. when the screen is small this rule is discarded and only one component per row is shown.

Below image shows various screen size widths :

screen size definitions

<button> background image

Try changing your CSS to this

button #rock {
    background: url('img/rock.png') no-repeat;

...provided that the image is in that place

IIS7 - The request filtering module is configured to deny a request that exceeds the request content length

The following example Web.config file will configure IIS to deny access for HTTP requests where the length of the "Content-type" header is greater than 100 bytes.

                  <add header="Content-type" sizeLimit="100" />


How to check if array is empty or does not exist?

You want to do the check for undefined first. If you do it the other way round, it will generate an error if the array is undefined.

if (array === undefined || array.length == 0) {
    // array empty or does not exist


This answer is getting a fair amount of attention, so I'd like to point out that my original answer, more than anything else, addressed the wrong order of the conditions being evaluated in the question. In this sense, it fails to address several scenarios, such as null values, other types of objects with a length property, etc. It is also not very idiomatic JavaScript.

The foolproof approach
Taking some inspiration from the comments, below is what I currently consider to be the foolproof way to check whether an array is empty or does not exist. It also takes into account that the variable might not refer to an array, but to some other type of object with a length property.

if (!Array.isArray(array) || !array.length) {
  // array does not exist, is not an array, or is empty
  // ? do not attempt to process array

To break it down:

  1. Array.isArray(), unsurprisingly, checks whether its argument is an array. This weeds out values like null, undefined and anything else that is not an array.
    Note that this will also eliminate array-like objects, such as the arguments object and DOM NodeList objects. Depending on your situation, this might not be the behavior you're after.

  2. The array.length condition checks whether the variable's length property evaluates to a truthy value. Because the previous condition already established that we are indeed dealing with an array, more strict comparisons like array.length != 0 or array.length !== 0 are not required here.

The pragmatic approach
In a lot of cases, the above might seem like overkill. Maybe you're using a higher order language like TypeScript that does most of the type-checking for you at compile-time, or you really don't care whether the object is actually an array, or just array-like.

In those cases, I tend to go for the following, more idiomatic JavaScript:

if (!array || !array.length) {
    // array or array.length are falsy
    // ? do not attempt to process array

Or, more frequently, its inverse:

if (array && array.length) {
    // array and array.length are truthy
    // ? probably OK to process array

With the introduction of the optional chaining operator (Elvis operator) in ECMAScript 2020, this can be shortened even further:

if (!array?.length) {
    // array or array.length are falsy
    // ? do not attempt to process array

Or the opposite:

if (array?.length) {
    // array and array.length are truthy
    // ? probably OK to process array

'too many values to unpack', iterating over a dict. key=>string, value=>list

In Python3 iteritems() is no longer supported

Use .items

for field, possible_values in fields.items():
    print(field, possible_values)

How to delete multiple files at once in Bash on Linux?

Bash supports all sorts of wildcards and expansions.

Your exact case would be handled by brace expansion, like so:

$ rm -rf abc.log.2012-03-{14,27,28}

The above would expand to a single command with all three arguments, and be equivalent to typing:

$ rm -rf abc.log.2012-03-14 abc.log.2012-03-27 abc.log.2012-03-28

It's important to note that this expansion is done by the shell, before rm is even loaded.

Windows 7 environment variable not working in path

I had this problem in Windows 10 and it seemed to be solved after I closed "explorer.exe" in the Task Manager.

How do I change button size in Python?

Configuring a button (or any widget) in Tkinter is done by calling a configure method "config"

To change the size of a button called button1 you simple call

button1.config( height = WHATEVER, width = WHATEVER2 )

If you know what size you want at initialization these options can be added to the constructor.

button1 = Button(self, text = "Send", command = self.response1, height = 100, width = 100) 

How can I check if a program exists from a Bash script?

The which command might be useful. man which

It returns 0 if the executable is found and returns 1 if it's not found or not executable:


       which - locate a command


       which [-a] filename ...


       which returns the pathnames of the files which would
       be executed in the current environment, had its
       arguments been given as commands in a strictly
       POSIX-conformant shell. It does this by searching
       the PATH for executable files matching the names
       of the arguments.


       -a     print all matching pathnames of each argument


       0      if all specified commands are 
              found and executable

       1      if one or more specified commands is nonexistent
              or not executable

       2      if an invalid option is specified

The nice thing about which is that it figures out if the executable is available in the environment that which is run in - it saves a few problems...

How to use *ngIf else?

"bindEmail" it will check email is available or not. if email is exist than Logout will show otherwise Login will show

<li *ngIf="bindEmail;then logout else login"></li>
<ng-template #logout><li><a routerLink="/logout">Logout</a></li></ng-template>
<ng-template #login><li><a routerLink="/login">Login</a></li></ng-template>

Are there pointers in php?

Yes there is something similar to pointers in PHP but may not match with what exactly happens in c or c++. Following is one of the example.

$a = "test";
$b = "a";
echo $a;
echo $b;
echo $$b;


This illustrates similar concept of pointers in PHP.

How to check command line parameter in ".bat" file?

In addition to the other answers, which I subscribe, you may consider using the /I switch of the IF command.

... the /I switch, if specified, says to do case insensitive string compares.

it may be of help if you want to give case insensitive flexibility to your users to specify the parameters.

IF /I "%1"=="-b" GOTO SPECIFIC

How to set environment variables in Jenkins?

You can use Environment Injector Plugin to set environment variables in Jenkins at job and node levels. Below I will show how to set them at job level.

  1. From the Jenkins web interface, go to Manage Jenkins > Manage Plugins and install the plugin.

Environment Injector Plugin

  1. Go to your job Configure screen
  2. Find Add build step in Build section and select Inject environment variables
  3. Set the desired environment variable as VARIABLE_NAME=VALUE pattern. In my case, I changed value of USERPROFILE variable

enter image description here

If you need to define a new environment variable depending on some conditions (e.g. job parameters), then you can refer to this answer.

get value from DataTable

It looks like you have accidentally declared DataType as an array rather than as a string.

Change line 3 to:

Dim DataType As String = myTableData.Rows(i).Item(1)

That should work.

Check if an object belongs to a class in Java

If you ever need to do this dynamically, you can use the following:

boolean isInstance(Object object, Class<?> type) {
    return type.isInstance(object);

You can get an instance of java.lang.Class by calling the instance method Object::getClass on any object (returns the Class which that object is an instance of), or you can do class literals (for example, String.class, List.class, int[].class). There are other ways as well, through the reflection API (which Class itself is the entry point for).

How to create nonexistent subdirectories recursively using Bash?

While existing answers definitely solve the purpose, if your'e looking to replicate nested directory structure under two different subdirectories, then you can do this

mkdir -p {main,test}/{resources,scala/com/company}

It will create following directory structure under the directory from where it is invoked

+-- main
¦   +-- resources
¦   +-- scala
¦       +-- com
¦           +-- company
+-- test
    +-- resources
    +-- scala
        +-- com
            +-- company

The example was taken from this link for creating SBT directory structure

How do I set specific environment variables when debugging in Visual Studio?

Starting with NUnit 2.5 you can use /framework switch e.g.:

nunit-console myassembly.dll /framework:net-1.1

This is from NUnit's help pages.

Class type check in TypeScript

You can use the instanceof operator for this. From MDN:

The instanceof operator tests whether the prototype property of a constructor appears anywhere in the prototype chain of an object.

If you don't know what prototypes and prototype chains are I highly recommend looking it up. Also here is a JS (TS works similar in this respect) example which might clarify the concept:

    class Animal {_x000D_
        constructor(name) {_x000D_
   = name;_x000D_
    const animal = new Animal('fluffy');_x000D_
    // true because Animal in on the prototype chain of animal_x000D_
    console.log(animal instanceof Animal); // true_x000D_
    // Proof that Animal is on the prototype chain_x000D_
    console.log(Object.getPrototypeOf(animal) === Animal.prototype); // true_x000D_
    // true because Object in on the prototype chain of animal_x000D_
    console.log(animal instanceof Object); _x000D_
    // Proof that Object is on the prototype chain_x000D_
    console.log(Object.getPrototypeOf(Animal.prototype) === Object.prototype); // true_x000D_
    console.log(animal instanceof Function); // false, Function not on prototype chain_x000D_

The prototype chain in this example is:

animal > Animal.prototype > Object.prototype

Bytes of a string in Java

The pedantic answer (though not necessarily the most useful one, depending on what you want to do with the result) is:

string.length() * 2

Java strings are physically stored in UTF-16BE encoding, which uses 2 bytes per code unit, and String.length() measures the length in UTF-16 code units, so this is equivalent to:

final byte[] utf16Bytes= string.getBytes("UTF-16BE");

And this will tell you the size of the internal char array, in bytes.

Note: "UTF-16" will give a different result from "UTF-16BE" as the former encoding will insert a BOM, adding 2 bytes to the length of the array.

(Excel) Conditional Formatting based on Adjacent Cell Value

You need to take out the $ signs before the row numbers in the formula....and the row number used in the formula should correspond to the first row of data, so if you are applying this to the ("applies to") range $B$2:$B$5 it must be this formula


by using that "relative" version rather than your "absolute" one Excel (implicitly) adjusts the formula for each row in the range, as if you were copying the formula down

How to align title at center of ActionBar in default theme(Theme.Holo.Light)

This actually works:

  ActionBar.LayoutParams p = new ActionBar.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
        p.gravity = Gravity.CENTER;

You have to define custom_actionbar.xml layout which is as per your requirement e.g. :

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android=""


Why doesn't git recognize that my file has been changed, therefore git add not working

I had the same problem. Turns out I had two copies of the project and my terminal was in the wrong project folder!

How can I escape white space in a bash loop list?

You could use IFS (internal field separator) temporally using :

OLD_IFS=$IFS     # Stores Default IFS
IFS=$'\n'        # Set it to line break
for f in `find test/* -type d`; do
    echo $f



Passing a dictionary to a function as keyword parameters

In[1]: def myfunc(a=1, b=2):
In[2]:    print(a, b)

In[3]: mydict = {'a': 100, 'b': 200}

In[4]: myfunc(**mydict)
100 200

A few extra details that might be helpful to know (questions I had after reading this and went and tested):

  1. The function can have parameters that are not included in the dictionary
  2. You can not override a parameter that is already in the dictionary
  3. The dictionary can not have parameters that aren't in the function.


Number 1: The function can have parameters that are not included in the dictionary

In[5]: mydict = {'a': 100}
In[6]: myfunc(**mydict)
100 2

Number 2: You can not override a parameter that is already in the dictionary

In[7]: mydict = {'a': 100, 'b': 200}
In[8]: myfunc(a=3, **mydict)

TypeError: myfunc() got multiple values for keyword argument 'a'

Number 3: The dictionary can not have parameters that aren't in the function.

In[9]:  mydict = {'a': 100, 'b': 200, 'c': 300}
In[10]: myfunc(**mydict)

TypeError: myfunc() got an unexpected keyword argument 'c'

As requested in comments, a solution to Number 3 is to filter the dictionary based on the keyword arguments available in the function:

In[11]: import inspect
In[12]: mydict = {'a': 100, 'b': 200, 'c': 300}
In[13]: filtered_mydict = {k: v for k, v in mydict.items() if k in [ for p in inspect.signature(myfunc).parameters.values()]}
In[14]: myfunc(**filtered_mydict)
100 200

Another option is to accept (and ignore) additional kwargs in your function:

In[15]: def myfunc2(a=None, **kwargs):
In[16]:    print(a)

In[17]: mydict = {'a': 100, 'b': 200, 'c': 300}

In[18]: myfunc2(**mydict)

Notice further than you can use positional arguments and lists or tuples in effectively the same way as kwargs, here's a more advanced example incorporating both positional and keyword args:

In[19]: def myfunc3(a, *posargs, b=2, **kwargs):
In[20]:    print(a, b)
In[21]:    print(posargs)
In[22]:    print(kwargs)

In[23]: mylist = [10, 20, 30]
In[24]: mydict = {'b': 200, 'c': 300}

In[25]: myfunc3(*mylist, **mydict)
10 200
(20, 30)
{'c': 300}

What is the difference between a heuristic and an algorithm?

  • An algorithm is typically deterministic and proven to yield an optimal result
  • A heuristic has no proof of correctness, often involves random elements, and may not yield optimal results.

Many problems for which no efficient algorithm to find an optimal solution is known have heuristic approaches that yield near-optimal results very quickly.

There are some overlaps: "genetic algorithms" is an accepted term, but strictly speaking, those are heuristics, not algorithms.

How to replace a string in multiple files in linux command line

I found this one from another post (can't remember which) and while not the most elegant, it's simple and as a novice Linux user has given me no trouble

for i in *old_str* ; do mv -v "$i" "${i/\old_str/new_str}" ; done

if you have spaces or other special characters use a \

for i in *old_str\ * ; do mv -v "$i" "${i/\old_str\ /new_str}" ; done

for strings in sub-directories use **

for i in *\*old_str\ * ; do mv -v "$i" "${i/\old_str\ /new_str}" ; done

How can I get key's value from dictionary in Swift?

For finding value use below

if let a = companies["AAPL"] {
   // a is the value

For traversing through the dictionary

for (key, value) in companies {
    print(key,"---", value)

Finally for searching key by value you firstly add the extension

extension Dictionary where Value: Equatable {
    func findKey(forValue val: Value) -> Key? {
        return first(where: { $1 == val })?.key

Then just call

companies.findKey(val : "Apple Inc")

How to convert hex to rgb using Java?

To elaborate on the answer @xhh provided, you can append the red, green, and blue to format your string as "rgb(0,0,0)" before returning it.

* @param colorStr e.g. "#FFFFFF"
* @return String - formatted "rgb(0,0,0)"
public static String hex2Rgb(String colorStr) {
    Color c = new Color(
        Integer.valueOf(hexString.substring(1, 3), 16), 
        Integer.valueOf(hexString.substring(3, 5), 16), 
        Integer.valueOf(hexString.substring(5, 7), 16));

    StringBuffer sb = new StringBuffer();
    return sb.toString();


The idea of REpresentational State Transfer is not about accessing data in the simplest way possible.

You suggested using post requests to access JSON, which is a perfectly valid way to access/manipulate data.

REST is a methodology for meaningful access of data. When you see a request in REST, it should immediately be apparant what is happening with the data.

For example:

GET: /cars/make/chevrolet

is likely going to return a list of chevy cars. A good REST api might even incorporate some output options in the querystring like ?output=json or ?output=html which would allow the accessor to decide what format the information should be encoded in.

After a bit of thinking about how to reasonably incorporate data typing into a REST API, I've concluded that the best way to specify the type of data explicitly would be via the already existing file extension such as .js, .json, .html, or .xml. A missing file extension would default to whatever format is default (such as JSON); a file extension that's not supported could return a 501 Not Implemented status code.

Another example:

POST: /cars/
{ make:chevrolet, model:malibu, colors:[red, green, blue, grey] }

is likely going to create a new chevy malibu in the db with the associated colors. I say likely as the REST api does not need to be directly related to the database structure. It is just a masking interface so that the true data is protected (think of it like accessors and mutators for a database structure).

Now we need to move onto the issue of idempotence. Usually REST implements CRUD over HTTP. HTTP uses GET, PUT, POST and DELETE for the requests.

A very simplistic implementation of REST could use the following CRUD mapping:

Create -> Post
Read   -> Get
Update -> Put
Delete -> Delete

There is an issue with this implementation: Post is defined as a non-idempotent method. This means that subsequent calls of the same Post method will result in different server states. Get, Put, and Delete, are idempotent; which means that calling them multiple times should result in an identical server state.

This means that a request such as:

Delete: /cars/oldest

could actually be implemented as:

Post: /cars/oldest?action=delete


Delete: /cars/id/123456

will result in the same server state if you call it once, or if you call it 1000 times.

A better way of handling the removal of the oldest item would be to request:

Get: /cars/oldest

and use the ID from the resulting data to make a delete request:

Delete: /cars/id/[oldest id]

An issue with this method would be if another /cars item was added between when /oldest was requested and when the delete was issued.

How to find pg_config path

I used :

export PATH=$PATH:/Library/PostgreSQL/9.6/bin

pip install psycopg2

Android ViewPager with bottom dots

I thought of posting a simpler solution for the above problem and indicator numbers can be dynamically changed with only changing one variable value dotCounts=x what I did goes like this.

1) Create an xml file in drawable folder for page selected indicator named "item_selected".

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android=""
    android:shape="oval" android:useLevel="true"
    <size android:height="8dp" android:width="8dp"/>
    <solid android:color="@color/image_item_selected_for_dots"/>

2) Create one more xml file for unselected indicator named "item_unselected"

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android=""
    android:shape="oval" android:useLevel="true"

    <size android:height="8dp" android:width="8dp"/>

    <solid android:color="@color/image_item_unselected_for_dots"/>

3) Now add add this part of the code at the place where you want to display the indicators for ex below viewPager in your Layout XML file.


            android:orientation="horizontal" />

4) Add this function on top of your activity file file where your layout is inflated or the above xml file is related to

private int dotsCount=5;    //No of tabs or images
private ImageView[] dots;
LinearLayout linearLayout;

private void drawPageSelectionIndicators(int mPosition){
    if(linearLayout!=null) {
    dots = new ImageView[dotsCount];
    for (int i = 0; i < dotsCount; i++) {
        dots[i] = new ImageView(context);

        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(

        params.setMargins(4, 0, 4, 0);
        linearLayout.addView(dots[i], params);

5) Finally in your onCreate method add the following code to reference your layout and handle pageselected positions

mPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

    public void onPageSelected(int position) {

    public void onPageScrollStateChanged(int state) {

How to use and style new AlertDialog from appCompat 22.1 and above

If you're like me you just want to modify some of the colors in AppCompat, and the only color you need to uniquely change in the dialog is the background. Then all you need to do is set a color for colorBackgroundFloating.

Here's my basic theme that simply modifies some colors with no nested themes:

    <style name="AppTheme" parent="Theme.AppCompat">
        <item name="colorPrimary">@color/theme_colorPrimary</item>
        <item name="colorPrimaryDark">@color/theme_colorPrimaryDark</item>
        <item name="colorAccent">@color/theme_colorAccent</item>
        <item name="colorControlActivated">@color/theme_colorControlActivated</item>
        <item name="android:windowBackground">@color/theme_bg</item>
        <item name="colorBackgroundFloating">@color/theme_dialog_bg</item><!-- Dialog background color -->
        <item name="colorButtonNormal">@color/theme_colorPrimary</item>
        <item name="colorControlHighlight">@color/theme_colorAccent</item>

How can I uninstall npm modules in Node.js?

Update for npm 5:

As of npm 5.0.0, installed/uninstalled modules are added/removed as a dependency by default, so the --save option is no longer needed.


npm uninstall <package>

For example:

npm uninstall mongodb

It will remove the module from the node_modules folder and also the package.json file.

Detect If Browser Tab Has Focus

While searching about this problem, I found a recommendation that Page Visibility API should be used. Most modern browsers support this API according to Can I Use:

Here's a working example (derived from this snippet):

$(document).ready(function() {
  var hidden, visibilityState, visibilityChange;

  if (typeof document.hidden !== "undefined") {
    hidden = "hidden", visibilityChange = "visibilitychange", visibilityState = "visibilityState";
  } else if (typeof document.msHidden !== "undefined") {
    hidden = "msHidden", visibilityChange = "msvisibilitychange", visibilityState = "msVisibilityState";

  var document_hidden = document[hidden];

  document.addEventListener(visibilityChange, function() {
    if(document_hidden != document[hidden]) {
      if(document[hidden]) {
        // Document hidden
      } else {
        // Document shown

      document_hidden = document[hidden];

Update: The example above used to have prefixed properties for Gecko and WebKit browsers, but I removed that implementation because these browsers have been offering Page Visibility API without a prefix for a while now. I kept Microsoft specific prefix in order to stay compatible with IE10.

How can I generate Unix timestamps?

In Perl:

>> time
=> 1335552733

Accessing JSON elements

'temp_C' is a key inside dictionary that is inside a list that is inside a dictionary

This way works:

>> '10'

What is the difference between git pull and git fetch + git rebase?


git pull is like running git fetch then git merge
git pull --rebase is like git fetch then git rebase

In reply to your first statement,

git pull is like a git fetch + git merge.

"In its default mode, git pull is shorthand for git fetch followed by git merge FETCH_HEAD" More precisely, git pull runs git fetch with the given parameters and then calls git merge to merge the retrieved branch heads into the current branch"


For your second statement/question:

'But what is the difference between git pull VS git fetch + git rebase'

Again, from same source:
git pull --rebase

"With --rebase, it runs git rebase instead of git merge."

Now, if you wanted to ask

'the difference between merge and rebase'

that is answered here too:
(the difference between altering the way version history is recorded)

MySQL Query GROUP BY day / month / year

.... group by to_char(date, 'YYYY') --> 1989

.... group by to_char(date,'MM') -->05

.... group by to_char(date,'DD') --->23

.... group by to_char(date,'MON') --->MAY

.... group by to_char(date,'YY') --->89

What is the best way to delete a value from an array in Perl?

You could use array slicing instead of splicing. Grep to return the indices you want keep and use slicing:

my @arr = ...;
# run through each item.
my @indicesToKeep = grep { $arr[$_] ne 'foo' } 0..$#arr;
@arr = @arr[@indicesToKeep];

Column calculated from another column?

MySQL 5.7 supports computed columns. They call it "Generated Columns" and the syntax is a little weird, but it supports the same options I see in other databases.

Visual Studio keyboard shortcut to display IntelliSense

If you want to change whether it highlights the best fitting possibility, use:

Ctrl + Alt + Space

SMTP connect() failed PHPmailer - PHP

The solution of this problem is really very simple. actually Google start using a new authorization mechanism for its User.. you might have seen another line in debug console prompting you to log into your account using any browser.! this is because of new XOAUTH2 authentication mechanism which google start using since 2014. remember.. do not use the ssl over port 465, instead go for tls over 587. this is just because of XOAUTH2 authentication mechanism. if you use ssl over 465, your request will be bounced back.

what you really need to do is .. log into your google account and open up following address and check turn on . you have to do this for letting you to connect with the google SMTP because according to new authentication mechanism google bounce back all the requests from all those applications which does not follow any standard encryption technique.. after checking turn on.. you are good to go.. here is the code which worked fine for me..

require_once 'C:\xampp\htdocs\email\vendor\autoload.php';

define ('GUSER','[email protected]');
define ('GPWD','your password');

// make a separate file and include this file in that. call this function in that file.

function smtpmailer($to, $from, $from_name, $subject, $body) { 
    global $error;
    $mail = new PHPMailer();  // create a new object
    $mail->IsSMTP(); // enable SMTP
    $mail->SMTPDebug = 2;  // debugging: 1 = errors and messages, 2 = messages only
    $mail->SMTPAuth = true;  // authentication enabled
    $mail->SMTPSecure = 'tls'; // secure transfer enabled REQUIRED for GMail
    $mail->SMTPAutoTLS = false;
    $mail->Host = '';
    $mail->Port = 587;

    $mail->Username = GUSER;  
    $mail->Password = GPWD;           
    $mail->SetFrom($from, $from_name);
    $mail->Subject = $subject;
    $mail->Body = $body;
    if(!$mail->Send()) {
        $error = 'Mail error: '.$mail->ErrorInfo; 
        return false;
    } else {
        $error = 'Message sent!';
        return true;

ASP.NET MVC 5 - Identity. How to get current ApplicationUser

The code of Ellbar works! You need only add using.

1 - using Microsoft.AspNet.Identity;

And... the code of Ellbar:

2 - string currentUserId = User.Identity.GetUserId(); ApplicationUser currentUser = db.Users.FirstOrDefault(x => x.Id == currentUserId);

With this code (in currentUser), you work the general data of the connected user, if you want extra data... see this link

SQL Server Express CREATE DATABASE permission denied in database 'master'

I know, it is an old question, but no solution worked for me. Here is what I did:

USE master 

Repeat this with every permission you need, for example GRANT CREATE DATABASE TO PUBLIC, ... You must have the server role "public" (yes, I am captain obvious).

Note 1: GRANT ALL TO PUBLIC is deprecated, does not work anymore in 2017.

Note 2: I tried to build an msi installer using the wix toolset. This toolset calls a powershell file, wich creates the databases, ... Just to give you some background information :)

Useful example of a shutdown hook in Java?

You could do the following:

  • Let the shutdown hook set some AtomicBoolean (or volatile boolean) "keepRunning" to false
  • (Optionally, .interrupt the working threads if they wait for data in some blocking call)
  • Wait for the working threads (executing writeBatch in your case) to finish, by calling the Thread.join() method on the working threads.
  • Terminate the program

Some sketchy code:

  • Add a static volatile boolean keepRunning = true;
  • In run() you change to

    for (int i = 0; i < N && keepRunning; ++i)
        writeBatch(pw, i);
  • In main() you add:

    final Thread mainThread = Thread.currentThread();
    Runtime.getRuntime().addShutdownHook(new Thread() {
        public void run() {
            keepRunning = false;

That's roughly how I do a graceful "reject all clients upon hitting Control-C" in terminal.

From the docs:

When the virtual machine begins its shutdown sequence it will start all registered shutdown hooks in some unspecified order and let them run concurrently. When all the hooks have finished it will then run all uninvoked finalizers if finalization-on-exit has been enabled. Finally, the virtual machine will halt.

That is, a shutdown hook keeps the JVM running until the hook has terminated (returned from the run()-method.

What does [STAThread] do?

It tells the compiler that you're in a Single Thread Apartment model. This is an evil COM thing, it's usually used for Windows Forms (GUI's) as that uses Win32 for its drawing, which is implemented as STA. If you are using something that's STA model from multiple threads then you get corrupted objects.

This is why you have to invoke onto the Gui from another thread (if you've done any forms coding).

Basically don't worry about it, just accept that Windows GUI threads must be marked as STA otherwise weird stuff happens.

How to use XPath in Python?

PyXML works well.

You didn't say what platform you're using, however if you're on Ubuntu you can get it with sudo apt-get install python-xml. I'm sure other Linux distros have it as well.

If you're on a Mac, xpath is already installed but not immediately accessible. You can set PY_USE_XMLPLUS in your environment or do it the Python way before you import xml.xpath:

if sys.platform.startswith('darwin'):
    os.environ['PY_USE_XMLPLUS'] = '1'

In the worst case you may have to build it yourself. This package is no longer maintained but still builds fine and works with modern 2.x Pythons. Basic docs are here.

Flask ImportError: No Module Named Flask

Go to the flask file in microblog, then activate the virtual environment with source bin/activate, then go to flask/bin and install flask, and the rest of the packages, pip install flask. You will see flask listed inside bin directory. Try to run ./ again from microblog (or from wherever you have the file).

SQL Server Regular expressions in T-SQL

If you are using SQL Server 2016 or above, you can use sp_execute_external_script along with R. It has functions for Regular Expression searches, such as grep and grepl.

Here's an example for email addresses. I'll query some "people" via the SQL Server database engine, pass the data for those people to R, let R decide which people have invalid email addresses, and have R pass back that subset of people to SQL Server. The "people" are from the [Application].[People] table in the [WideWorldImporters] sample database. They get passed to the R engine as a dataframe named InputDataSet. R uses the grepl function with the "not" operator (exclamation point!) to find which people have email addresses that don't match the RegEx string search pattern.

EXEC sp_execute_external_script 
 @language = N'R',
 @script = N' RegexWithR <- InputDataSet;
OutputDataSet <- RegexWithR[!grepl("([_a-z0-9-]+(\\.[_a-z0-9-]+)*@[a-z0-9-]+(\\.[a-z0-9-]+)*(\\.[a-z]{2,4}))", RegexWithR$EmailAddress), ];',
 @input_data_1 = N'SELECT PersonID, FullName, EmailAddress FROM Application.People'
 WITH RESULT SETS (([PersonID] INT, [FullName] NVARCHAR(50), [EmailAddress] NVARCHAR(256)))

Note that the appropriate features must be installed on the SQL Server host. For SQL Server 2016, it is called "SQL Server R Services". For SQL Server 2017, it was renamed to "SQL Server Machine Learning Services".

Closing Thoughts Microsoft's implementation of SQL (T-SQL) doesn't have native support for RegEx. This proposed solution may not be any more desirable to the OP than the use of a CLR stored procedure. But it does offer an additional way to approach the problem.

How do I execute a PowerShell script automatically using Windows task scheduler?

You can use the Unblock-File cmdlet to unblock the execution of this specific script. This prevents you doing any permanent policy changes which you may not want due to security concerns.

Unblock-File path_to_your_script

Source: Unblock-File

Mercurial undo last commit

hg strip will completely remove a revision (and any descendants) from the repository.

To use strip you'll need to install MqExtension by adding the following lines to your .hgrc (or mercurial.ini):

mq =

In TortoiseHg the strip command is available in the workbench. Right click on a revision and choose 'Modify history' -> 'Strip'.

Since strip changes the the repository's history you should only use it on revisions which haven't been shared with anyone yet. If you are using mercurial 2.1+ you can uses phases to track this information. If a commit is still in the draft phase it hasn't been shared with other repositories so you can safely strip it. (Thanks to Zasurus for pointing this out).

How to get the selected value from RadioButtonList?

string radioListValue = RadioButtonList.Text;

Alert handling in Selenium WebDriver (selenium 2) with Java

        //Handle the alert pop-up using seithTO alert statement
        Alert alert = driver.switchTo().alert();

        //Print alert is present
        System.out.println("Alert is present");

        //get the message which is present on pop-up
        String message = alert.getText();

        //print the pop-up message

        //Click on OK button on pop-up
    catch (NoAlertPresentException e) 
        //if alert is not present print message
        System.out.println("alert is not present");

Clearing a string buffer/builder after loop

Already good answer there. Just add a benchmark result for StringBuffer and StringBuild performance difference use new instance in loop or use setLength(0) in loop.

The summary is: In a large loop

  • StringBuilder is much faster than StringBuffer
  • Create new StringBuilder instance in loop have no difference with setLength(0). (setLength(0) have very very very tiny advantage than create new instance.)
  • StringBuffer is slower than StringBuilder by create new instance in loop
  • setLength(0) of StringBuffer is extremely slower than create new instance in loop.

Very simple benchmark (I just manually changed the code and do different test ):

public class StringBuilderSpeed {
public static final char ch[] = new char[]{'a','b','c','d','e','f','g','h','i'};

public static void main(String a[]){
    int loopTime = 99999999;
    long startTime = System.currentTimeMillis();
    StringBuilder sb = new StringBuilder();
    for(int i = 0 ; i < loopTime; i++){
        for(char c : ch){
    long endTime = System.currentTimeMillis();
    System.out.println("Time cost: " + (endTime - startTime));


New StringBuilder instance in loop: Time cost: 3693, 3862, 3624, 3742

StringBuilder setLength: Time cost: 3465, 3421, 3557, 3408

New StringBuffer instance in loop: Time cost: 8327, 8324, 8284

StringBuffer setLength Time cost: 22878, 23017, 22894

Again StringBuilder setLength to ensure not my labtop got some issue to use such long for StringBuffer setLength :-) Time cost: 3448

How to pass multiple parameters in thread in VB

Just create a class or structure that has two members, one List(Of OneItem) and the other Integer and send in an instance of that class.

Edit: Sorry, missed that you had problems with one parameter as well. Just look at Thread Constructor (ParameterizedThreadStart) and that page includes a simple sample.

Is there a command line command for verifying what version of .NET is installed

You can write yourself a little console app and use System.Environment.Version to find out the version. Scott Hanselman gives a blog post about it.

Or look in the registry for the installed versions. HKLM\Software\Microsoft\NETFramework Setup\NDP

Merging multiple PDFs using iTextSharp in

I found the answer:

Instead of the 2nd Method, add more files to the first array of input files.

public static void CombineMultiplePDFs(string[] fileNames, string outFile)
    // step 1: creation of a document-object
    Document document = new Document();
    //create newFileStream object which will be disposed at the end
    using (FileStream newFileStream = new FileStream(outFile, FileMode.Create))
       // step 2: we create a writer that listens to the document
       PdfCopy writer = new PdfCopy(document, newFileStream );
       if (writer == null)

       // step 3: we open the document

       foreach (string fileName in fileNames)
           // we create a reader for a certain document
           PdfReader reader = new PdfReader(fileName);

           // step 4: we add content
           for (int i = 1; i <= reader.NumberOfPages; i++)
               PdfImportedPage page = writer.GetImportedPage(reader, i);

           PRAcroForm form = reader.AcroForm;
           if (form != null)


       // step 5: we close the document and writer
   }//disposes the newFileStream object

If my interface must return Task what is the best way to have a no-operation implementation?

return Task.CompletedTask; // this will make the compiler happy

Firing events on CSS class changes in jQuery

Good question. I'm using the Bootstrap Dropdown Menu, and needed to execute an event when a Bootstrap Dropdown was hidden. When the dropdown is opened, the containing div with a class name of "button-group" adds a class of "open"; and the button itself has an "aria-expanded" attribute set to true. When the dropdown is closed, that class of "open" is removed from the containing div, and aria-expanded is switched from true to false.

That led me to this question, of how to detect the class change.

With Bootstrap, there are "Dropdown Events" that can be detected. Look for "Dropdown Events" at this link.

Here is a quick-and-dirty example of using this event on a Bootstrap Dropdown.

$(document).on('', function(event) {

Now I realize this is more specific than the general question that's being asked. But I imagine other developers trying to detect an open or closed event with a Bootstrap Dropdown will find this helpful. Like me, they may initially go down the path of simply trying to detect an element class change (which apparently isn't so simple). Thanks.

Xcode 4 - build output directory

Keep derived data but use the DSTROOT to specify the destination.

Use DEPLOYMENT_LOCATION to force deployment.

Use the undocumented DWARF_DSYM_FOLDER_PATH to copy the dSYM over too.

This allows you to use derived data location from xcodebuild and not have to do wacky stuff to find the app.

xcodebuild -sdk "iphoneos" -workspace Foo.xcworkspace -scheme Foo -configuration "Debug" DEPLOYMENT_LOCATION=YES DSTROOT=tmp DWARF_DSYM_FOLDER_PATH=tmp build

Removing nan values from an array

filter(lambda v: v==v, x)

works both for lists and numpy array since v!=v only for NaN

sendUserActionEvent() is null

This has to do with having two buttons with the same ID in two different Activities, sometimes Android Studio can't find, You just have to give your button a new ID and re Build the Project

How can I check if a checkbox is checked?

You can try this:

if ($(#remember).is(':checked')){
   alert('not checked')

curl usage to get header

You need to add the -i flag to the first command, to include the HTTP header in the output. This is required to print headers.

curl -X HEAD -i

More here:

How to Determine the Screen Height and Width in Flutter

We have noticed that using the MediaQuery class can be a bit cumbersome, and it’s also missing a couple of key pieces of information.

Here We have a small Screen helper class, that we use across all our new projects:

class Screen {
  static double get _ppi => (Platform.isAndroid || Platform.isIOS)? 150 : 96;
  static bool isLandscape(BuildContext c) => MediaQuery.of(c).orientation == Orientation.landscape;
  static Size size(BuildContext c) => MediaQuery.of(c).size;
  static double width(BuildContext c) => size(c).width;
  static double height(BuildContext c) => size(c).height;
  static double diagonal(BuildContext c) {
    Size s = size(c);
    return sqrt((s.width * s.width) + (s.height * s.height));
  static Size inches(BuildContext c) {
    Size pxSize = size(c);
    return Size(pxSize.width / _ppi, pxSize.height/ _ppi);
  static double widthInches(BuildContext c) => inches(c).width;
  static double heightInches(BuildContext c) => inches(c).height;
  static double diagonalInches(BuildContext c) => diagonal(c) / _ppi;

To use

bool isLandscape = Screen.isLandscape(context)
bool isLargePhone = Screen.diagonal(context) > 720;
bool isTablet = Screen.diagonalInches(context) >= 7;
bool isNarrow = Screen.widthInches(context) < 3.5;

To More, See:

How to put an image in div with CSS?

Take this as a sample code. Replace imageheight and image width with your image dimensions.

<div style="background:yourimage.jpg no-repeat;height:imageheight px;width:imagewidth px">

mysql: get record count between two date-time

select * from yourtable where created < now() and created > '2011-04-25 04:00:00'

How do I get a list of files in a directory in C++?

If you're in Windows & using MSVC, the MSDN library has sample code that does this.

And here's the code from that link:

#include <windows.h>
#include <tchar.h> 
#include <stdio.h>
#include <strsafe.h>

void ErrorHandler(LPTSTR lpszFunction);

int _tmain(int argc, TCHAR *argv[])
   WIN32_FIND_DATA ffd;
   LARGE_INTEGER filesize;
   size_t length_of_arg;
   DWORD dwError=0;

   // If the directory is not specified as a command-line argument,
   // print usage.

   if(argc != 2)
      _tprintf(TEXT("\nUsage: %s <directory name>\n"), argv[0]);
      return (-1);

   // Check that the input path plus 2 is not longer than MAX_PATH.

   StringCchLength(argv[1], MAX_PATH, &length_of_arg);

   if (length_of_arg > (MAX_PATH - 2))
      _tprintf(TEXT("\nDirectory path is too long.\n"));
      return (-1);

   _tprintf(TEXT("\nTarget directory is %s\n\n"), argv[1]);

   // Prepare string for use with FindFile functions.  First, copy the
   // string to a buffer, then append '\*' to the directory name.

   StringCchCopy(szDir, MAX_PATH, argv[1]);
   StringCchCat(szDir, MAX_PATH, TEXT("\\*"));

   // Find the first file in the directory.

   hFind = FindFirstFile(szDir, &ffd);

   if (INVALID_HANDLE_VALUE == hFind) 
      return dwError;

   // List all the files in the directory with some info about them.

      if (ffd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
         _tprintf(TEXT("  %s   <DIR>\n"), ffd.cFileName);
         filesize.LowPart = ffd.nFileSizeLow;
         filesize.HighPart = ffd.nFileSizeHigh;
         _tprintf(TEXT("  %s   %ld bytes\n"), ffd.cFileName, filesize.QuadPart);
   while (FindNextFile(hFind, &ffd) != 0);

   dwError = GetLastError();
   if (dwError != ERROR_NO_MORE_FILES) 

   return dwError;

void ErrorHandler(LPTSTR lpszFunction) 
    // Retrieve the system error message for the last-error code

    LPVOID lpMsgBuf;
    LPVOID lpDisplayBuf;
    DWORD dw = GetLastError(); 

        (LPTSTR) &lpMsgBuf,
        0, NULL );

    // Display the error message and exit the process

    lpDisplayBuf = (LPVOID)LocalAlloc(LMEM_ZEROINIT, 
        LocalSize(lpDisplayBuf) / sizeof(TCHAR),
        TEXT("%s failed with error %d: %s"), 
        lpszFunction, dw, lpMsgBuf); 
    MessageBox(NULL, (LPCTSTR)lpDisplayBuf, TEXT("Error"), MB_OK); 


How to get all keys with their values in redis

I refined the bash solution a bit, so that the more efficient scan is used instead of keys, and printing out array and hash values is supported. My solution also prints out the key name.


# Default to '*' key pattern, meaning all redis keys in the namespace
for key in $(redis-cli --scan --pattern "$REDIS_KEY_PATTERN")
    type=$(redis-cli type $key)
    if [ $type = "list" ]
        printf "$key => \n$(redis-cli lrange $key 0 -1 | sed 's/^/  /')\n"
    elif [ $type = "hash" ]
        printf "$key => \n$(redis-cli hgetall $key | sed 's/^/  /')\n"
        printf "$key => $(redis-cli get $key)\n"

Note: you can formulate a one-liner of this script by removing the first line of and commanding: cat | tr '\n' ';' | awk '$1=$1'

Extracting the top 5 maximum values in excel

Given a data setup like this:

Top 5 by criteria

The formula in cell D2 and copied down is:


This formula will work even if there are tied OPS scores among players.

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

Jimmy's answer correctly represents the continuous JavaScript integer spectrum as -9007199254740992 to 9007199254740992 inclusive (sorry 9007199254740993, you might think you are 9007199254740993, but you are wrong! Demonstration below or in jsfiddle).


However, there is no answer that finds/proves this programatically (other than the one CoolAJ86 alluded to in his answer that would finish in 28.56 years ;), so here's a slightly more efficient way to do that (to be precise, it's more efficient by about 28.559999999968312 years :), along with a test fiddle:

 * Checks if adding/subtracting one to/from a number yields the correct result._x000D_
 * @param number The number to test_x000D_
 * @return true if you can add/subtract 1, false otherwise._x000D_
var canAddSubtractOneFromNumber = function(number) {_x000D_
    var numMinusOne = number - 1;_x000D_
    var numPlusOne = number + 1;_x000D_
    return ((number - numMinusOne) === 1) && ((number - numPlusOne) === -1);_x000D_
//Find the highest number_x000D_
var highestNumber = 3; //Start with an integer 1 or higher_x000D_
//Get a number higher than the valid integer range_x000D_
while (canAddSubtractOneFromNumber(highestNumber)) {_x000D_
    highestNumber *= 2;_x000D_
//Find the lowest number you can't add/subtract 1 from_x000D_
var numToSubtract = highestNumber / 4;_x000D_
while (numToSubtract >= 1) {_x000D_
    while (!canAddSubtractOneFromNumber(highestNumber - numToSubtract)) {_x000D_
        highestNumber = highestNumber - numToSubtract;_x000D_
    numToSubtract /= 2;_x000D_
}        _x000D_
//And there was much rejoicing.  Yay.    _x000D_
console.log('HighestNumber = ' + highestNumber);

I can not find my.cnf on my windows computer

Here is my answer:

  1. Win+R (shortcut for 'run'), type services.msc, Enter
  2. You should find an entry like 'MySQL56', right click on it, select properties
  3. You should see something like "D:/Program Files/MySQL/MySQL Server 5.6/bin\mysqld" --defaults-file="D:\ProgramData\MySQL\MySQL Server 5.6\my.ini" MySQL56

Full answer here:

Regex any ASCII character

If you really mean any and ASCII (not e.g. all Unicode characters):


JavaScript example:

var re = /xxx[\x00-\x7F]+xxx/;

// true

// false

Compute row average in pandas

I think this is what you are looking for:

df.drop('Region', axis=1).apply(lambda x: x.mean(), axis=1)

Update cordova plugins in one command

cordova-check-plugins --update=auto --force

use the command line

How to convert a Base64 string into a Bitmap image to show it in a ImageView?

You can just basically revert your code using some other built in methods.

byte[] decodedString = Base64.decode(encodedImage, Base64.DEFAULT);
Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length); 

How do I debug jquery AJAX calls?

if you are using mozilla firefox than just install an add-on called firebug.

In your page press f12 in mozilla and firebug will open.

go for the net tab in firebug and in this tab go in the xhr tab. and reload your page. you will get 5 options in xhr Params Headers Response HTML and Cookies

so by going in response and html you can see which response you are getting after your ajax call.

Please let me know if you have any issue.

How to make Python speak

install pip install pypiwin32

How to use the text to speech features of a Windows PC

from win32com.client import Dispatch

speak = Dispatch("SAPI.SpVoice").Speak


Using google text-to-speech Api to create an mp3 and hear it

After you installed the gtts module in cmd: pip install gtts

from gtts import gTTS
import os    

tts = gTTS(text="This is the pc speaking", lang='en')"pcvoice.mp3")
# to start the file from python
os.system("start pcvoice.mp3")

Run Batch File On Start-up

If your Windows language is different from English, you can launch the Task Scheduler by

  1. Press Windows+X
  2. Select your language translation of "Computer Management"
  3. Follow the instruction in the answer provided by prankin

How to filter by IP address in Wireshark?


ip.dst ==

python save image from url

For linux in case; you can use wget command

import os
os.system('wget {}'.format(url1))

failed to lazily initialize a collection of role

Lazy exceptions occur when you fetch an object typically containing a collection which is lazily loaded, and try to access that collection.

You can avoid this problem by

  • accessing the lazy collection within a transaction.
  • Initalizing the collection using Hibernate.initialize(obj);
  • Fetch the collection in another transaction
  • Use Fetch profiles to select lazy/non-lazy fetching runtime
  • Set fetch to non-lazy (which is generally not recommended)

Further I would recommend looking at the related links to your right where this question has been answered many times before. Also see Hibernate lazy-load application design.

How to set at runtime?

Another approach, if you're desperate and don't have access to (a) the code or (b) the command line, then you can use environment variables:

Specifically for java web start set the environment variable:


and for applets:



Additionally, under Windows global options (for general Java applications) can be set in the Java control plan page under the "Java" tab.

Crop image to specified size and picture location

You would need to do something like this. I am typing this off the top of my head, so this may not be 100% correct.

CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); CGContextRef context = CGBitmapContextCreate(NULL, 640, 360, 8, 4 * width, colorSpace, kCGImageAlphaPremultipliedFirst); CGColorSpaceRelease(colorSpace);  CGContextDrawImage(context, CGRectMake(0,-160,640,360), cgImgFromAVCaptureSession);  CGImageRef image = CGBitmapContextCreateImage(context); UIImage* myCroppedImg = [UIImage imageWithCGImage:image]; CGContextRelease(context);       

How to send Request payload to REST API in java?

The following code works for me.

//escape the double quotes in json string
String payload="{\"jsonrpc\":\"2.0\",\"method\":\"changeDetail\",\"params\":[{\"id\":11376}],\"id\":2}";
String requestUrl="";
sendPostRequest(requestUrl, payload);

method implementation:

public static String sendPostRequest(String requestUrl, String payload) {
    try {
        URL url = new URL(requestUrl);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();

        connection.setRequestProperty("Accept", "application/json");
        connection.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
        OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream(), "UTF-8");
        BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
        StringBuffer jsonString = new StringBuffer();
        String line;
        while ((line = br.readLine()) != null) {
        return jsonString.toString();
    } catch (Exception e) {
            throw new RuntimeException(e.getMessage());


Determine if JavaScript value is an "integer"?

Try this:

if(Math.floor(id) == id && $.isNumeric(id)) 
  alert('yes its an int!');

$.isNumeric(id) checks whether it's numeric or not
Math.floor(id) == id will then determine if it's really in integer value and not a float. If it's a float parsing it to int will give a different result than the original value. If it's int both will be the same.

How to increase MaximumErrorCount in SQL Server 2008 Jobs or Packages?

If I have open a package in BIDS ("Business Intelligence Development Studio", the tool you use to design the packages), and do not select any item in it, I have a "Properties" pane in the bottom right containing - among others, the MaximumErrorCount property. If you do not see it, maybe it is minimized and you have to open it (have a look at tabs in the right).

If you cannot find it this way, try the menu: View/Properties Window.

Or try the F4 key.

.htaccess: where is located when not in www base dir

The .htaccess is either in the root-directory of your webpage or in the directory you want to protect.

Make sure to make them visible in your filesystem, because AFAIK (I'm no unix expert either) files starting with a period are invisible by default on unix-systems.

how to print a string to console in c++

yes it's possible to print a string to the console.

#include "stdafx.h"
#include <string>
#include <iostream>

using namespace std;

int _tmain(int argc, _TCHAR* argv[])
    string strMytestString("hello world");
    cout << strMytestString;
    return 0;

stdafx.h isn't pertinent to the solution, everything else is.

Test if a string contains a word in PHP?

//  Use this function and Pass Mixed string and what you want to search in mixed string.
//  For Example :
    $mixedStr = "hello world. This is john duvey";
    $searchStr= "john";

    if(strpos($mixedStr,$searchStr)) {
      echo "Your string here";
    }else {
      echo "String not here";

shuffling/permutating a DataFrame in pandas

Sampling randomizes, so just sample the entire data frame.


What is the correct value for the disabled attribute?

From MDN by setAttribute():

To set the value of a Boolean attribute, such as disabled, you can specify any value. An empty string or the name of the attribute are recommended values. All that matters is that if the attribute is present at all, regardless of its actual value, its value is considered to be true. The absence of the attribute means its value is false. By setting the value of the disabled attribute to the empty string (""), we are setting disabled to true, which results in the button being disabled.

Link to MDN


  • I mean that in XHTML Strict is right disabled="disabled",
  • and in HTML5 is only disabled, like <input name="myinput" disabled>
  • In javascript, I set the value to true via e.disabled = true;
    or to "" via setAttribute( "disabled", "" );

Test in Chrome

var f = document.querySelectorAll( "label.disabled input" );
for( var i = 0; i < f.length; i++ )
    // Reference
    var e = f[ i ];

    // Actions
    e.setAttribute( "disabled", false|null|undefined|""|0|"disabled" );
        <input disabled="false"|"null"|"undefined"|empty|"0"|"disabled">
        e.getAttribute( "disabled" ) === "false"|"null"|"undefined"|""|"0"|"disabled"
        e.disabled === true
    e.removeAttribute( "disabled" );
        e.getAttribute( "disabled" ) === null
        e.disabled === false

    e.disabled = false|null|undefined|""|0;
        e.getAttribute( "disabled" ) === null|null|null|null|null
        e.disabled === false

    e.disabled = true|" "|"disabled"|1;
        <input disabled>
        e.getAttribute( "disabled" ) === ""|""|""|""
        e.disabled === true

What's the console.log() of java?

public class Console {

    public static void Log(Object obj){

to call and use as JavaScript just do this:

Console.Log (Object)

I think that's what you mean

How to use JavaScript source maps (.map files)?

The .map files are for js and css (and now ts too) files that have been minified. They are called SourceMaps. When you minify a file, like the angular.js file, it takes thousands of lines of pretty code and turns it into only a few lines of ugly code. Hopefully, when you are shipping your code to production, you are using the minified code instead of the full, unminified version. When your app is in production, and has an error, the sourcemap will help take your ugly file, and will allow you to see the original version of the code. If you didn't have the sourcemap, then any error would seem cryptic at best.

Same for CSS files. Once you take a SASS or LESS file and compile it to CSS, it looks nothing like its original form. If you enable sourcemaps, then you can see the original state of the file, instead of the modified state.

So, to answer you questions in order:

  • What is it for? To de-reference uglified code
  • How can a developer use it? You use it for debugging a production app. In development mode you can use the full version of Angular. In production, you would use the minified version.
  • Should I care about creating a file? If you care about being able to debug production code easier, then yes, you should do it.
  • How does it get created? It is created at build time. There are build tools that can build your .map file for you as it does other files.

I hope this makes sense.

How to run a script as root on Mac OS X?

As in any unix-based environment, you can use the sudo command:

$ sudo script-name

It will ask for your password (your own, not a separate root password).

Closing Excel Application using VBA

You can try out

ThisWorkbook.Saved = True

Calling dynamic function with dynamic number of parameters

Couldn't you just pass the arguments array along?

function mainfunc (func){
    // remove the first argument containing the function name
    window[func].apply(null, arguments);

function calledfunc1(args){
    // Do stuff here

function calledfunc2(args){
    // Do stuff here


How do I solve this "Cannot read property 'appendChild' of null" error?

The element hasn't been appended yet, therefore it is equal to null. The Id will never = 0. When you call getElementById(id), it is null since it is not a part of the dom yet unless your static id is already on the DOM. Do a call through the console to see what it returns.

How to disable editing of elements in combobox for c#?

Use the ComboStyle property:

comboBox.DropDownStyle = ComboBoxStyle.DropDownList;

How can I get the named parameters from a URL using Flask?

You can also use brackets <> on the URL of the view definition and this input will go into your view function arguments

def my_view_func(name):
    return name

How to make MySQL handle UTF-8 properly

To make this 'permanent', in my.cnf:

character-set-server = utf8

To check, go to the client and show some variables:

SHOW VARIABLES LIKE 'character_set%';

Verify that they're all utf8, except ..._filesystem, which should be binary and ..._dir, that points somewhere in the MySQL installation.

Save current directory in variable using Bash?

On a BASH shell, you can very simply run:

export PATH=$PATH:`pwd`/somethingelse

No need to save the current working directory into a variable...

Initialize a string variable in Python: "" or None?

Either way is okay in python. I would personally prefer "". but again, either way is okay

>>>x = None
<class 'NoneType'>
>>>x = "hello there"
hello there
<class 'str'>
>>>x = ""

<class 'str'>
>>>x = "hello there"
<class 'str'>
hello there

Evaluate expression given as a string

Sorry but I don't understand why too many people even think a string was something that could be evaluated. You must change your mindset, really. Forget all connections between strings on one side and expressions, calls, evaluation on the other side.

The (possibly) only connection is via parse(text = ....) and all good R programmers should know that this is rarely an efficient or safe means to construct expressions (or calls). Rather learn more about substitute(), quote(), and possibly the power of using, ......).

fortunes::fortune("answer is parse")
# If the answer is parse() you should usually rethink the question.
#    -- Thomas Lumley
#       R-help (February 2005)

Dec.2017: Ok, here is an example (in comments, there's no nice formatting):

q5 <- quote(5+5)
# language 5 + 5

e5 <- expression(5+5)
# expression(5 + 5)

and if you get more experienced you'll learn that q5 is a "call" whereas e5 is an "expression", and even that e5[[1]] is identical to q5:

identical(q5, e5[[1]])
# [1] TRUE

Angular - res.json() is not a function

HttpClient.get() applies res.json() automatically and returns Observable<HttpResponse<string>>. You no longer need to call this function yourself.

See Difference between HTTP and HTTPClient in angular 4?

Hibernate vs JPA vs JDO - pros and cons of each?

Which would you suggest for a new project?

I would suggest neither! Use Spring DAO's JdbcTemplate together with StoredProcedure, RowMapper and RowCallbackHandler instead.

My own personal experience with Hibernate is that the time saved up-front is more than offset by the endless days you will spend down the line trying to understand and debug issues like unexpected cascading update behaviour.

If you are using a relational DB then the closer your code is to it, the more control you have. Spring's DAO layer allows fine control of the mapping layer, whilst removing the need for boilerplate code. Also, it integrates into Spring's transaction layer which means you can very easily add (via AOP) complicated transactional behaviour without this intruding into your code (of course, you get this with Hibernate too).

Setting default values for columns in JPA

You can define the default value in the database designer, or when you create the table. For instance in SQL Server you can set the default vault of a Date field to (getDate()). Use insertable=false as mentioned in your column definition. JPA will not specify that column on inserts and the database will generate the value for you.

Location of GlassFish Server Logs

tail -f /path/to/glassfish/domains/YOURDOMAIN/logs/server.log

You can also upload log from admin console : http://yoururl:4848

enter image description here

How to echo or print an array in PHP?

To see the contents of array you can use.

1) print_r($array); or if you want nicely formatted array then:

echo '<pre>'; print_r($array); echo '</pre>';

2) use var_dump($array) to get more information of the content in the array like datatype and length.

3) you can loop the array using php's foreach(); and get the desired output. more info on foreach in php's documentation website:

Powershell Active Directory - Limiting my get-aduser search to a specific OU [and sub OUs]

If I understand you correctly, you need to use -SearchBase:

Get-ADUser -SearchBase "OU=Accounts,OU=RootOU,DC=ChildDomain,DC=RootDomain,DC=com" -Filter *

Note that Get-ADUser defaults to using

 -SearchScope Subtree

so you don't need to specify it. It's this that gives you all sub-OUs (and sub-sub-OUs, etc.).

How can I do width = 100% - 100px in CSS?

You can't.

You can, however, use margins to effect the same result.

AES Encryption for an NSString on the iPhone

I waited a bit on @QuinnTaylor to update his answer, but since he didn't, here's the answer a bit more clearly and in a way that it will load on XCode7 (and perhaps greater). I used this in a Cocoa application, but it likely will work okay with an iOS application as well. Has no ARC errors.

Paste before any @implementation section in your AppDelegate.m or file.

#import <CommonCrypto/CommonCryptor.h>

@implementation NSData (AES256)

- (NSData *)AES256EncryptWithKey:(NSString *)key {
    // 'key' should be 32 bytes for AES256, will be null-padded otherwise
    char keyPtr[kCCKeySizeAES256+1]; // room for terminator (unused)
    bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)

    // fetch key data
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

    NSUInteger dataLength = [self length];

    //See the doc: For block ciphers, the output size will always be less than or 
    //equal to the input size plus the size of one block.
    //That's why we need to add the size of one block here
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);

    size_t numBytesEncrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
                                     keyPtr, kCCKeySizeAES256,
                                     NULL /* initialization vector (optional) */,
                                     [self bytes], dataLength, /* input */
                                     buffer, bufferSize, /* output */
    if (cryptStatus == kCCSuccess) {
        //the returned NSData takes ownership of the buffer and will free it on deallocation
        return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];

    free(buffer); //free the buffer;
    return nil;

- (NSData *)AES256DecryptWithKey:(NSString *)key {
    // 'key' should be 32 bytes for AES256, will be null-padded otherwise
    char keyPtr[kCCKeySizeAES256+1]; // room for terminator (unused)
    bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)

    // fetch key data
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

    NSUInteger dataLength = [self length];

    //See the doc: For block ciphers, the output size will always be less than or 
    //equal to the input size plus the size of one block.
    //That's why we need to add the size of one block here
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);

    size_t numBytesDecrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
                                     keyPtr, kCCKeySizeAES256,
                                     NULL /* initialization vector (optional) */,
                                     [self bytes], dataLength, /* input */
                                     buffer, bufferSize, /* output */

    if (cryptStatus == kCCSuccess) {
        //the returned NSData takes ownership of the buffer and will free it on deallocation
        return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];

    free(buffer); //free the buffer;
    return nil;


Paste these two functions in the @implementation class you desire. In my case, I chose @implementation AppDelegate in my or AppDelegate.m file.

- (NSString *) encryptString:(NSString*)plaintext withKey:(NSString*)key {
    NSData *data = [[plaintext dataUsingEncoding:NSUTF8StringEncoding] AES256EncryptWithKey:key];
    return [data base64EncodedStringWithOptions:kNilOptions];

- (NSString *) decryptString:(NSString *)ciphertext withKey:(NSString*)key {
    NSData *data = [[NSData alloc] initWithBase64EncodedString:ciphertext options:kNilOptions];
    return [[NSString alloc] initWithData:[data AES256DecryptWithKey:key] encoding:NSUTF8StringEncoding];

Register .NET Framework 4.5 in IIS 7.5

Hosting 4.5/4.5.1 Web application on Local IIS 1)Be Sure IIS Installation before Visual Installation Installataion then aspnet_regiis will already registerd with IIS

If Not Install IIS and then Register aspnet_regiis with IIS by cmd Editor

For VS2012 and 32 bit OS Run Below code on command editor :

1)Install IIS First & then


cd C:\Windows\Microsoft.NET\Framework\v4.0.30319   

  C:\Windows\Microsoft.NET\Framework\v4.0.30319> aspnet_regiis -i

For VS2012 and 64 bit OS Below code on command editor:

1)Install IIS First & then


cd C:\Windows\Microsoft.NET\Framework64\v4.0.30319    
  C:\Windows\Microsoft.NET\Framework64\v4.0.30319> aspnet_regiis -i

BY Following Above Steps Current Version of VS2012 registered with IIS Hosting (VS2012 Web APP)

Create VS2012 Web Application(WebForm/MVC) then Build Application Right Click On WebApplication(WebForm/MVC) go to 'Properties' Click On 'Web' Tab on then 'Use Local IIS Web Server' Then Uncheck 'Use IIS Express' (If Visul Studio 2013 Select 'Local IIS' from Dropdown) Provide Project Url like "http://localhost/MvcDemoApp" Then Click On 'Create Virtual Directory' Button Then Open IIS by Prssing 'Window + R' Run Command and type 'inetmgr' and 'Enter' (or 'OK' Button) Then Expand 'Sites->Default Web Site' you Hosted Successfully. If Still Gets any Server Error like 'The resource cannot be found.' Then Include following code in web.config

         <modules runAllManagedModulesForAllRequests="true"></modules>

And Run Application

If still problem occurs Check application pool by : In iis Right click on application->Manage Application->Advanced setting->General. you see the application pool. then close advance setting window. click on 'Application Pools' you will see the all application pools in middle window. Right click on application pool in which application hosted(DefaultAppPool). click 'Basic Setting' -> Change .Net FrameWork Version to->.Net FrameWork v4.0.30349

Killing a process using Java

It might be a java interpreter defect, but java on HPUX does not do a kill -9, but only a kill -TERM.

I did a small test

ProcessBuilder pb = new ProcessBuilder(args);
Process process = pb.start();

And the invocation:

$ tusc -f -p -s signal,kill -e /opt/java1.5/bin/java testDestroy sh -c 'trap "echo TERM" TERM; sleep 10'

dies after 10s (not killed after 1s as expected) and shows:

[19999]   Received signal 15, SIGTERM, in waitpid(), [caught], no siginfo
[19998] kill(19999, SIGTERM) ............................................................................. = 0

Doing the same on windows seems to kill the process fine even if signal is handled (but that might be due to windows not using signals to destroy).

Actually i found Java - Process.destroy() source code for Linux related thread and openjava implementation seems to use -TERM as well, which seems very wrong.

requestFeature() must be called before adding content

Doesn't the error exactly tell you what's wrong? You're calling requestWindowFeature and setFeatureInt after you're calling setContentView.

By the way, why are you calling setContentView twice?

Cannot create JDBC driver of class ' ' for connect URL 'null' : I do not understand this exception

Several fixes:

  1. Use the right driver class name for your environment: if you are using an out-of-process Derby server, then you want ClientDriver (and need to use derbyclient.jar), the hostname and port, etc. If you want an in-process Derby server, then you want derby.jar, EmbeddedDriver, and a URL that is appropriate for an embedded database.

  2. Put your driver JAR file only in Tomcat's lib/ directory.

  3. Don't put anything in Tomcat's conf/context.xml: there's really no reason for it. Instead, use your webapp's META-INF/context.xml to define your <Resource>.

The error "Cannot create JDBC driver of class '' for connect URL 'null' usually occurs because the JDBC driver is not in the right place (or in too many places, like Tomcat's lib/ directory but also in the webapp's WEB-INF/lib/ directory). Please verify that you have the right driver JAR file in the right place.

What does a Status of "Suspended" and high DiskIO means from sp_who2?

This is a very broad question, so I am going to give a broad answer.

  1. A query gets suspended when it is requesting access to a resource that is currently not available. This can be a logical resource like a locked row or a physical resource like a memory data page. The query starts running again, once the resource becomes available. 
  2. High disk IO means that a lot of data pages need to be accessed to fulfill the request.

That is all that I can tell from the above screenshot. However, if I were to speculate, you probably have an IO subsystem that is too slow to keep up with the demand. This could be caused by missing indexes or an actually too slow disk. Keep in mind, that 15000 reads for a single OLTP query is slightly high but not uncommon.

Curl Command to Repeat URL Request

for i in `seq 1 20`; do curl http://url; done

Or if you want to get timing information back, use ab:

ab -n 20 http://url/

How to Split Image Into Multiple Pieces in Python

Splitting image to tiles of MxN pixels (assuming im is numpy.ndarray):

tiles = [im[x:x+M,y:y+N] for x in range(0,im.shape[0],M) for y in range(0,im.shape[1],N)]

In the case you want to split the image to four pieces:

M = im.shape[0]//2
N = im.shape[1]//2

tiles[0] holds the upper left tile

C# Numeric Only TextBox Control


// Boolean flag used to determine when a character other than a number is entered.
private bool nonNumberEntered = false;
// Handle the KeyDown event to determine the type of character entered into the control.
private void textBox1_KeyDown(object sender, KeyEventArgs e)
    // Initialize the flag to false.
    nonNumberEntered = false;
    // Determine whether the keystroke is a number from the top of the keyboard.
    if (e.KeyCode < Keys.D0 || e.KeyCode > Keys.D9)
        // Determine whether the keystroke is a number from the keypad.
        if (e.KeyCode < Keys.NumPad0 || e.KeyCode > Keys.NumPad9)
            // Determine whether the keystroke is a backspace.
            if (e.KeyCode != Keys.Back)
                // A non-numerical keystroke was pressed.
                // Set the flag to true and evaluate in KeyPress event.
                nonNumberEntered = true;

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
    if (nonNumberEntered == true)
       MessageBox.Show("Please enter number only..."); 
       e.Handled = true;

Source is

Evenly space multiple views within a container view

Android has a method of chaining views together in its constraint based layout system that I wanted to mimic. Searches brought me here but none of the answers quite worked. I didn't want to use StackViews because they tend to cause me more grief down the line than they save up front. I ended up creating a solution that used UILayoutGuides placed between the views. Controlling their width's allows different types of distributions, chain styles in Android parlance. The function accepts a leading and trailing anchor instead of a parent view. This allows the chain to be placed between two arbitrary views rather than distributed inside of the parent view. It does use UILayoutGuide which is only available in iOS 9+ but that shouldn't be a problem anymore.

public enum LayoutConstraintChainStyle {
    case spread //Evenly distribute between the anchors
    case spreadInside //Pin the first & last views to the sides and then evenly distribute
    case packed //The views have a set space but are centered between the anchors.

public extension NSLayoutConstraint {

    static func chainHorizontally(views: [UIView],
                                  leadingAnchor: NSLayoutXAxisAnchor,
                                  trailingAnchor: NSLayoutXAxisAnchor,
                                  spacing: CGFloat = 0.0,
                                  style: LayoutConstraintChainStyle = .spread) -> [NSLayoutConstraint] {
    var constraints = [NSLayoutConstraint]()
    guard views.count > 1 else { return constraints }
    guard let first = views.first, let last = views.last, let superview = first.superview else { return constraints }

    //Setup the chain of views
    var distributionGuides = [UILayoutGuide]()
    var previous = first
    let firstGuide = UILayoutGuide()
    firstGuide.identifier = "ChainDistribution\(distributionGuides.count)"
    constraints.append(firstGuide.leadingAnchor.constraint(equalTo: leadingAnchor))
    constraints.append(first.leadingAnchor.constraint(equalTo: firstGuide.trailingAnchor, constant: spacing))
    views.dropFirst().forEach { view in
        let g = UILayoutGuide()
        g.identifier = "ChainDistribution\(distributionGuides.count)"
        constraints.append(contentsOf: [
            g.leadingAnchor.constraint(equalTo: previous.trailingAnchor),
            view.leadingAnchor.constraint(equalTo: g.trailingAnchor)
        previous = view
    let lastGuide = UILayoutGuide()
    constraints.append(contentsOf: [lastGuide.leadingAnchor.constraint(equalTo: last.trailingAnchor),
                                    lastGuide.trailingAnchor.constraint(equalTo: trailingAnchor)])

    //Space the according to the style.
    switch style {
    case .packed:
        if let first = distributionGuides.first, let last = distributionGuides.last {
            constraints.append(first.widthAnchor.constraint(greaterThanOrEqualToConstant: spacing))
            constraints.append(last.widthAnchor.constraint(greaterThanOrEqualToConstant: spacing))
            constraints.append(last.widthAnchor.constraint(equalTo: first.widthAnchor))
                    .map { $0.widthAnchor.constraint(equalToConstant: spacing) }
    case .spread:
        if let first = distributionGuides.first {
                distributionGuides.dropFirst().map { $0.widthAnchor.constraint(equalTo: first.widthAnchor) })
    case .spreadInside:
        if let first = distributionGuides.first, let last = distributionGuides.last {
            constraints.append(first.widthAnchor.constraint(equalToConstant: spacing))
            constraints.append(last.widthAnchor.constraint(equalToConstant: spacing))
            let innerGuides = distributionGuides.dropFirst().dropLast()
            if let key = innerGuides.first {
                    innerGuides.dropFirst().map { $0.widthAnchor.constraint(equalTo: key.widthAnchor) }

    return constraints

Send HTTP POST message in ASP.NET Core using HttpClient PostAsJsonAsync

I use this class:

public class JsonContent : StringContent
    public JsonContent(object obj) :
        base(JsonConvert.SerializeObject(obj), Encoding.UTF8, "application/json")
    { }

Sample of usage:

new HttpClient().PostAsync("http://...", new JsonContent(new { x = 1, y = 2 }));

I have filtered my Excel data and now I want to number the rows. How do I do that?

Try this:

On first row set value 1 (e.g cell A1)

on next row set: =A1+1

Finally autocomplete the remaining rows

Merge/flatten an array of arrays

If you need to support IE8 and, therefore, can't use methods such as reduce or isArray, here is a possible solution. It is a verbose approach to help you to understand the recursive algorithm.

function flattenArray(a){

    var aFinal = [];

    (function recursiveArray(a){

        var i,
            iCount = a.length;

        if ( === '[object Array]') {
            for (i = 0; i < iCount; i += 1){
        } else {


    return aFinal;


var aMyArray = [6,3,4,[12,14,15,[23,24,25,[34,35],27,28],56],3,4];

var result = flattenArray(aMyArray);


How to resolve 'npm should be run outside of the node repl, in your normal shell'

Do not run the application using node.js icon.

Go to All Programmes->Node.js->Node.js command prompt.

Below is example screen shot.

enter image description here

enter image description here

How to pass a querystring or route parameter to AWS Lambda from Amazon API Gateway

exports.handler = async (event) => {
    let query = event.queryStringParameters;
    console.log(`id: ${}`);
    const response = {
        statusCode: 200,
        body: "Hi",
    return response;

Add object to ArrayList at specified index

How about this little while loop as a solution?

private ArrayList<Object> list = new ArrayList<Object>();

private void addObject(int i, Object object) {
    while(list.size() < i) {
        list.add(list.size(), null);
    list.add(i, object);

addObject(1, object1)
addObject(3, object3)
addObject(2, object2)

zsh compinit: insecure directories

This morning, some packages in my system updated, and left me with this error message. I am using Ubuntu 18.04.

Apparently, something in the update changed the username and group to numbers, instead of root, as so:

# There are insecure files: /usr/share/zsh/vendor-completions/_code
# sudo ls -alh
-rw-r--r-- 1  131  142 2.6K 2019-10-10 16:28 _code

I simply changed the user and group for this file back to root and the problem went away. I did not need to change any permissions, and would caution against doing so unless the underlying cause of the problem is understood.

sudo chown root _code && sudo chgrp root _code

After switching 131 and 142 back to root, this error message from zsh went away.

Does MySQL ignore null values on unique constraints?

Yes, MySQL allows multiple NULLs in a column with a unique constraint.

INSERT table1 VALUES (1);
INSERT table1 VALUES (1);   -- Duplicate entry '1' for key 'x'
SELECT * FROM table1;



This is not true for all databases. SQL Server 2005 and older, for example, only allows a single NULL value in a column that has a unique constraint.

In Gradle, is there a better way to get Environment Variables?

I couldn't get the form suggested by @thoredge to work in Gradle 1.11, but this works for me:

home = System.getenv('HOME')

It helps to keep in mind that anything that works in pure Java will work in Gradle too.

Activity has leaked window that was originally added

I was also facing this problem for some time but I realized it's not because of dialog in my case it's because of ActionMode. So if you are trying to finish activity when an ActionMode is open it will cause this problem. In your activity's onPause finish the action mode.

 private ActionMode actionMode;

 public void onActionModeStarted(ActionMode mode) {
    actionMode = mode;

 protected void onPause() {
    if (actionMode != null) actionMode.finish();

Check if Key Exists in NameValueCollection

You could use the Get method and check for null as the method will return null if the NameValueCollection does not contain the specified key.


C# elegant way to check if a property's property is null

It is not possible.
ObjectA.PropertyA.PropertyB will fail if ObjectA is null due to null dereferencing, which is an error.

if(ObjectA != null && ObjectA.PropertyA ... works due to short circuiting, ie ObjectA.PropertyA will never be checked if ObjectA is null.

The first way you propose is the best and most clear with intent. If anything you could try to redesign without having to rely on so many nulls.

Entity Framework VS LINQ to SQL VS ADO.NET with stored procedures?

your question is basically O/RM's vs hand writing SQL

Using an ORM or plain SQL?

Take a look at some of the other O/RM solutions out there, L2S isn't the only one (NHibernate, ActiveRecord)

to address the specific questions:

  1. Depends on the quality of the O/RM solution, L2S is pretty good at generating SQL
  2. This is normally much faster using an O/RM once you grok the process
  3. Code is also usually much neater and more maintainable
  4. Straight SQL will of course get you more flexibility, but most O/RM's can do all but the most complicated queries
  5. Overall I would suggest going with an O/RM, the flexibility loss is negligable

Difference between java.lang.RuntimeException and java.lang.Exception

In Java, there are two types of exceptions: checked exceptions and un-checked exceptions. A checked exception must be handled explicitly by the code, whereas, an un-checked exception does not need to be explicitly handled.

For checked exceptions, you either have to put a try/catch block around the code that could potentially throw the exception, or add a "throws" clause to the method, to indicate that the method might throw this type of exception (which must be handled in the calling class or above).

Any exception that derives from "Exception" is a checked exception, whereas a class that derives from RuntimeException is un-checked. RuntimeExceptions do not need to be explicitly handled by the calling code.

Is Ruby pass by reference or by value?

Try this:--

#=> 3

#=> 5

a = 1
#=> 1
#=> 3

b = 2
#=> 2
#=> 5

identifier a contains object_id 3 for value object 1 and identifier b contains object_id 5 for value object 2.

Now do this:--

a.object_id = 5
#=> error

a = b
#value(object_id) at b copies itself as value(object_id) at a. value object 2 has object_id 5
#=> 2

#=> 5

Now, a and b both contain same object_id 5 which refers to value object 2. So, Ruby variable contains object_ids to refer to value objects.

Doing following also gives error:--

#=> error

but doing this won't give error:--

#=> 11

c = 5
#=> value object 5 provides return type for variable c and saves 5.object_id i.e. 11 at c
#=> 5
#=> 11 

a = c.object_id
#=> object_id of c as a value object changes value at a
#=> 11
#=> 23
a.object_id == 11.object_id
#=> true

#=> Value at a
#=> 11

Here identifier a returns value object 11 whose object id is 23 i.e. object_id 23 is at identifier a, Now we see an example by using method.

def foo(arg)
  p arg
  p arg.object_id
#=> nil
#=> 23
x = 11
#=> 11
#=> 23
#=> 11
#=> 23

arg in foo is assigned with return value of x. It clearly shows that argument is passed by value 11, and value 11 being itself an object has unique object id 23.

Now see this also:--

def foo(arg)
  p arg
  p arg.object_id
  arg = 12
  p arg
  p arg.object_id

#=> nil
#=> 23
x = 11
#=> 11
#=> 23
#=> 11
#=> 23
#=> 12
#=> 25
#=> 11
#=> 23

Here, identifier arg first contains object_id 23 to refer 11 and after internal assignment with value object 12, it contains object_id 25. But it does not change value referenced by identifier x used in calling method.

Hence, Ruby is pass by value and Ruby variables do not contain values but do contain reference to value object.

How to access single elements in a table in R

?"[" pretty much covers the various ways of accessing elements of things.

Under usage it lists these:

x[i, j, ... , drop = TRUE]
x[[i, exact = TRUE]]
x[[i, j, ..., exact = TRUE]]
getElement(object, name)

x[i] <- value
x[i, j, ...] <- value
x[[i]] <- value
x$i <- value

The second item is sufficient for your purpose

Under Arguments it points out that with [ the arguments i and j can be numeric, character or logical

So these work:


As does this:


and keeping in mind a data frame is a list of vectors:


will also both work.

So that's a few things to be going on with. I suggest you type in the examples at the bottom of the help page one line at a time (yes, actually type the whole thing in one line at a time and see what they all do, you'll pick up stuff very quickly and the typing rather than copypasting is an important part of helping to commit it to memory.)

What is the use of


class ExamTest{

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

If you want get char input you have to cast like this: char sn=(char)

The value byte is returned as int in the range 0 to 255. However, unlike in other languages’ methods, reads only a byte at a time.

Moving average or running mean

For educational purposes, let me add two more Numpy solutions (which are slower than the cumsum solution):

import numpy as np
from numpy.lib.stride_tricks import as_strided

def ra_strides(arr, window):
    ''' Running average using as_strided'''
    n = arr.shape[0] - window + 1
    arr_strided = as_strided(arr, shape=[n, window], strides=2*arr.strides)
    return arr_strided.mean(axis=1)

def ra_add(arr, window):
    ''' Running average using add.reduceat'''
    n = arr.shape[0] - window + 1
    indices = np.array([0, window]*n) + np.repeat(np.arange(n), 2)
    arr = np.append(arr, 0)
    return np.add.reduceat(arr, indices )[::2]/window

Functions used: as_strided, add.reduceat

Revert to Eclipse default settings

I was having this problem in Eclipse Luna (4.4.2)

  1. Exit Eclipse
  2. Deleted the following under the .metadata/.plugins/org.eclipse.core.runtime/.settings directory
    • com.aptana.theme.prefs
    • com.github.eclipsecolortheme.prefs
    • org.eclipse.e4.ui.css.swt.theme.prefs
  3. Started Eclipse
  4. In Preferences > General > Appeareance > Color Theme > check "Set all background colors to default"

Without step 4. a vertical strip near line numbers remained the older background color

What is log4j's default log file dumping path

By default, Log4j logs to standard output and that means you should be able to see log messages on your Eclipse's console view. To log to a file you need to use a FileAppender explicitly by defining it in a file in your classpath.

Create the following file in your classpath. This allows you to log your message to both a file as well as your console.

log4j.rootLogger=debug, stdout, file


# Pattern to output the caller's file name and line number.
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] (%F:%L) - %m%n

log4j.appender.file.layout.ConversionPattern=%p %t %c - %m%n

Note: The above creates an example.log in your current working directory (i.e. Eclipse's project directory) so that the same could work with different projects without overwriting each other's logs.

Apache log4j 1.2 - Short introduction to log4j

Fragment Inside Fragment

Curently in nested fragment, the nested one(s) are only supported if they are generated programmatically! So at this time no nested fragment layout are supported in xml layout scheme!

Make virtualenv inherit specific packages from your global site-packages

Create the environment with virtualenv --system-site-packages . Then, activate the virtualenv and when you want things installed in the virtualenv rather than the system python, use pip install --ignore-installed or pip install -I . That way pip will install what you've requested locally even though a system-wide version exists. Your python interpreter will look first in the virtualenv's package directory, so those packages should shadow the global ones.


I had to use a slightly extended version @Erwin Brandstetter used:

  _db TEXT := 'some_db';
  _user TEXT := 'postgres_user';
  _password TEXT := 'password';
  CREATE EXTENSION IF NOT EXISTS dblink; -- enable extension 
  IF EXISTS (SELECT 1 FROM pg_database WHERE datname = _db) THEN
    RAISE NOTICE 'Database already exists';
    PERFORM dblink_connect('host=localhost user=' || _user || ' password=' || _password || ' dbname=' || current_database());
    PERFORM dblink_exec('CREATE DATABASE ' || _db);

I had to enable the dblink extension, plus i had to provide the credentials for dblink. Works with Postgres 9.4.

Get a list of all the files in a directory (recursive)

This code works for me:


def list = []

def dir = new File("path_to_parent_dir")
dir.eachFileRecurse (FileType.FILES) { file ->
  list << file

Afterwards the list variable contains all files ( of the given directory and its subdirectories:

list.each {
  println it.path

Convert JSON array to Python list

import json

array = '{"fruits": ["apple", "banana", "orange"]}'
data  = json.loads(array)
print data['fruits']
# the print displays:
# [u'apple', u'banana', u'orange']

You had everything you needed. data will be a dict, and data['fruits'] will be a list

How to remove CocoaPods from a project?

Removing CocoaPods from a project is possible, but not currently automated by the CLI. First thing, if the only issue you have is not being able to use an xcworkspace you can use CocoaPods with just xcodeprojs by using the --no-integrate flag which will produce the Pods.xcodeproj but not a workspace. Then you can add this xcodeproj as a subproject to your main xcodeproj.

If you really want to remove all CocoaPods integration you need to do a few things:

NOTE editing some of these things if done incorrectly could break your main project. I strongly encourage you to check your projects into source control just in case. Also these instructions are for CocoaPods version 0.39.0, they could change with new versions.

  1. Delete the standalone files (Podfile Podfile.lock and your Pods directory)
  2. Delete the generated xcworkspace
  3. Open your xcodeproj file, delete the references to Pods.xcconfig and libPods.a (in the Frameworks group)
  4. Under your Build Phases delete the Copy Pods Resources, Embed Pods Frameworks and Check Pods Manifest.lock phases.
  5. This may seem obvious but you'll need to integrate the 3rd party libraries some other way or remove references to them from your code.

After those steps you should be set with a single xcodeproj that existed before you integrated CocoaPods. If I missed anything let me know and I will edit this.

Also we're always looking for suggestions for how to improve CocoaPods so if you have an issues please submit them in our issue tracker so we can come up with a way to fix them!


As shown by Jack Wu in the comments there is a third party CocoaPods plugin that can automate these steps for you. It can be found here. Note that it is a third party plugin and might not always be updated when CocoaPods is. Also note that it is made by a CocoaPods core team member so that problem won't be a problem.

How to get date and time from server

For enable PHP Extension intl , follow the Steps..

  1. Open the xampp/php/php.ini file in any editor.
  2. Search ";extension=php_intl.dll"
  3. kindly remove the starting semicolon ( ; ) Like : ;extension=php_intl.dll. to. extension=php_intl.dll.
  4. Save the xampp/php/php.ini file.
  5. Restart your xampp/wamp.

How to generate gcc debug symbol outside the build target?

Compile with debug information:

gcc -g -o main main.c

Separate the debug information:

objcopy --only-keep-debug main main.debug


cp main main.debug
strip --only-keep-debug main.debug

Strip debug information from origin file:

objcopy --strip-debug main


strip --strip-debug --strip-unneeded main

debug by debuglink mode:

objcopy --add-gnu-debuglink main.debug main
gdb main

You can also use exec file and symbol file separatly:

gdb -s main.debug -e main


(gdb) exec-file main
(gdb) symbol-file main.debug

For details:

(gdb) help exec-file
(gdb) help symbol-file


document.createElement("script") synchronously

This isn't pretty, but it works:

<script type="text/javascript">
  document.write('<script type="text/javascript" src="other.js"></script>');

<script type="text/javascript">


<script type="text/javascript">
  document.write('<script type="text/javascript" src="other.js"></script>');
  window.onload = function() {

The script must be included either in a separate <script> tag or before window.onload().

This will not work:

<script type="text/javascript">
  document.write('<script type="text/javascript" src="other.js"></script>');
  functionFromOther(); // Error

The same can be done with creating a node, as Pointy did, but only in FF. You have no guarantee when the script will be ready in other browsers.

Being an XML Purist I really hate this. But it does work predictably. You could easily wrap those ugly document.write()s so you don't have to look at them. You could even do tests and create a node and append it then fall back on document.write().

Javascript get object key name

Assuming that you have access to Prototype, this could work. I wrote this code for myself just a few minutes ago; I only needed a single key at a time, so this isn't time efficient for big lists of key:value pairs or for spitting out multiple key names.

function key(int) {
    var j = -1;
    for(var i in this) {
        if(j==int) {
            return i;
        } else {
Object.prototype.key = key;

This is numbered to work the same way that arrays do, to save headaches. In the case of your code:

buttons.key(0) // Should result in "button1"

How do I set response headers in Flask?

This work for me

from flask import Flask
from flask import Response

app = Flask(__name__)

def home():
    return Response(headers={'Access-Control-Allow-Origin':'*'})

if __name__ == "__main__":

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

It's ugly, but you can use the setfacl command to achieve exactly what you want.

On a Solaris machine, I have a file that contains the acls for users and groups. Unfortunately, you have to list all of the users (at least I couldn't find a way to make this work otherwise):


Name the file acl.lst and fill in your real user names instead of user_X.

You can now set those acls on your directory by issuing the following command:

setfacl -f acl.lst /your/dir/here

Abstract variables in Java?

Define a constructor in the abstract class which sets the field so that the concrete implementations are per the specification required to call/override the constructor.


public abstract class AbstractTable {
    protected String name;

    public AbstractTable(String name) { = name;

When you extend AbstractTable, the class won't compile until you add a constructor which calls super("somename").

public class ConcreteTable extends AbstractTable {
    private static final String NAME = "concreteTable";

    public ConcreteTable() {

This way the implementors are required to set name. This way you can also do (null)checks in the constructor of the abstract class to make it more robust. E.g:

public AbstractTable(String name) {
    if (name == null) throw new NullPointerException("Name may not be null"); = name;

TLS 1.2 in .NET Framework 4.0

If you are not able to add a property to class library.

Then, add in Global.asax file:

ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072; //TLS 1.2
ServicePointManager.SecurityProtocol = (SecurityProtocolType)768; //TLS 1.1

And you can use it in a function, at the starting line:

ServicePointManager.SecurityProtocol = (SecurityProtocolType)768 | (SecurityProtocolType)3072;

And, it's being useful for STRIPE payment gateway, which only supports TLS 1.1, TLS 1.2.

EDIT: After so many questions on .NET 4.5 is installed on my server or not... here is the screenshot of Registry on my production server:

I have only .NET framework 4.0 installed.


How can I quickly sum all numbers in a file?

In Go:

package main

import (

func main() {
    scanner := bufio.NewScanner(os.Stdin)
    sum := int64(0)
    for scanner.Scan() {
        v, err := strconv.ParseInt(scanner.Text(), 10, 64)
        if err != nil {
            fmt.Fprintf(os.Stderr, "Not an integer: '%s'\n", scanner.Text())
        sum += v

Difference between SRC and HREF

If you're talking HTML4, its list of attributes might help you with the subtleties. They're not interchangeable.

Batch file to move files to another directory

Suppose there's a file test.txt in Root Folder, and want to move it to \TxtFolder,

You can try

move %~dp0\test.txt %~dp0\TxtFolder


reference answer: relative path in BAT script

Backup a single table with its data from a database in sql server 2008

To get a copy in a file on the local file-system, this rickety utility from the Windows start button menu worked: "C:\Program Files (x86)\Microsoft SQL Server\110\DTS\Binn\DTSWizard.exe"

How do I get bootstrap-datepicker to work with Bootstrap 3?

I also use Stefan Petre’s and it does not work with Bootstrap 3 without modification. Note that is a fork of Stefan Petre's code.

You have to change your markup (the sample markup will not work) to use the new CSS and form grid layout in Bootstrap 3. Also, you have to modify some CSS and JavaScript in the actual bootstrap-datepicker implementation.

Here is my solution:

<div class="form-group row">
  <div class="col-xs-8">
    <label class="control-label">My Label</label>
    <div class="input-group date" id="dp3" data-date="12-02-2012" data-date-format="mm-dd-yyyy">
      <input class="form-control" type="text" readonly="" value="12-02-2012">
      <span class="input-group-addon"><i class="glyphicon glyphicon-calendar"></i></span>

CSS changes in datepicker.css on lines 176-177: .input-group-addon i, .input-group-addon i {

Javascript change in datepicker-bootstrap.js on line 34:

this.component ='.date') ? this.element.find('.input-group-addon') : false;


Using the newer code from the changes are as follows:

CSS changes in datepicker.css on lines 446-447: .input-group-addon i, .input-group-addon i {

Javascript change in datepicker-bootstrap.js on line 46:

 this.component ='.date') ? this.element.find('.input-group-addon, .btn') : false;

Finally, the JavaScript to enable the datepicker (with some options):

 $("").datepicker({ autoclose: true, todayHighlight: true });

Tested with Bootstrap 3.0 and JQuery 1.9.1. Note that this fork is better to use than the other as it is more feature rich, has localization support and auto-positions the datepicker based on the control position and window size, avoiding the picker going off the screen which was a problem with the older version.

Bash: Syntax error: redirection unexpected


I was getting this problem from my Dockerfile as I had:

RUN bash < <(curl -s -S -L

However, according to this issue, it was solved:

The exec form makes it possible to avoid shell string munging, and to RUN commands using a base image that does not contain /bin/sh.


To use a different shell, other than /bin/sh, use the exec form passing in the desired shell. For example,

RUN ["/bin/bash", "-c", "echo hello"]


RUN ["/bin/bash", "-c", "bash < <(curl -s -S -L"]

Notice the quotes around each parameter.

This API project is not authorized to use this API. Please ensure that this API is activated in the APIs Console

Need to enable Directions API as well in the Google API Console. I have the following enabled:

  • Directions API
  • Geocoding API
  • Maps Javascript API

I also have Geolocation API enabled but the console doesn't show it as being used (0 requests). But maybe it's not real-time reporting so doesn't hurt to enable anyway.

Installing Homebrew on OS X

Check if Xcode is installed or not:

$ gcc --version

$ ruby -e "$(curl -fsSL"

$ brew doctor

$ brew update "click here for exact instruction updates"

Android - how to replace part of a string by another string?


In java, string objects are immutable. Immutable simply means unmodifiable or unchangeable.

Once string object is created its data or state can't be changed but a new string object is created.

gradlew: Permission Denied

if it doesn't work after chmod'ing make sure you aren't trying to execute it inside the /tmp directory.

How to set URL query params in Vue with Vue-Router

If you are trying to keep some parameters, while changing others, be sure to copy the state of the vue router query and not reuse it.

This works, since you are making an unreferenced copy:

  const query = Object.assign({}, this.$route.query); = page;
  query.limit = rowsPerPage;
  await this.$router.push({ query });

while below will lead to Vue Router thinking you are reusing the same query and lead to the NavigationDuplicated error:

  const query = this.$route.query; = page;
  query.limit = rowsPerPage;
  await this.$router.push({ query });

Of course, you could decompose the query object, such as follows, but you'll need to be aware of all the query parameters to your page, otherwise you risk losing them in the resultant navigation.

  const { page, limit, ...otherParams } = this.$route.query;
  await this.$router.push(Object.assign({
    page: page,
    limit: rowsPerPage
  }, otherParams));

Note, while the above example is for push(), this works with replace() too.

Tested with vue-router 3.1.6.

Real-world examples of recursion

Geometric calculations for GIS or cartography, such as finding the edge of a circle.

Getting DOM element value using pure JavaScript

In the second version, you're passing the String returned from Not the element itself.

So id.value won't give you what you want.

You would need to pass the element with this.



    var value = el.value;

Note: In some browsers, the second one would work if you did:


because element IDs are a global property, but this is not safe.

It makes the most sense to just pass the element with this instead of fetching it again with its ID.

Combining two Series into a DataFrame in pandas

Not sure I fully understand your question, but is this what you want to do?

pd.DataFrame(data=dict(s1=s1, s2=s2), index=s1.index)

(index=s1.index is not even necessary here)

WebView link click open default browser

You can use an Intent for this:

Uri uriUrl = Uri.parse(""); 
Intent launchBrowser = new Intent(Intent.ACTION_VIEW, uriUrl);  

How to set breakpoints in inline Javascript in Google Chrome?

My situation and what I did to fix it:
I have a javascript file included on an HTML page as follows:
Page Name: test.html

<!DOCTYPE html>
        <script src="scripts/common.js"></script>
        <title>Test debugging JS in Chrome</title>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
         <script type="text/javascript">


Now entering the Javascript Debugger in Chrome, I click the Scripts Tab, and drop down the list as shown above. I can clearly see scripts/common.js however I could NOT see the current html page test.html in the drop down, therefore I could not debug the embedded javascript:

<script type="text/javascript">

That was perplexing. However, when I removed the obsolete type="text/javascript" from the embedded script:


..and refreshed / reloaded the page, voila, it appeared in the drop down list, and all was well again.
I hope this is helpful to anyone who is having issues debugging embedded javascript on an html page.

Python os.path.join on Windows

The reason os.path.join('C:', 'src') is not working as you expect is because of something in the documentation that you linked to:

Note that on Windows, since there is a current directory for each drive, os.path.join("c:", "foo") represents a path relative to the current directory on drive C: (c:foo), not c:\foo.

As ghostdog said, you probably want mypath=os.path.join('c:\\', 'sourcedir')

How to search file text for a pattern and replace it with a given value

Actually, Ruby does have an in-place editing feature. Like Perl, you can say

ruby -pi.bak -e "gsub(/oldtext/, 'newtext')" *.txt

This will apply the code in double-quotes to all files in the current directory whose names end with ".txt". Backup copies of edited files will be created with a ".bak" extension ("foobar.txt.bak" I think).

NOTE: this does not appear to work for multiline searches. For those, you have to do it the other less pretty way, with a wrapper script around the regex.

How to edit the size of the submit button on a form?

Using CSS you can set a style for that specific button using the id (#) selector:

#search {
    width: 20em;  height: 2em;

or if you want all submit buttons to be a particular size:

input[type=submit] {
    width: 20em;  height: 2em;

or if you want certain classes of button to be a particular style you can use CSS classes:

<input type="submit" id="search" value="Search" class="search" />

and {
    width: 20em;  height: 2em;

I use ems as the measurement unit because they tend to scale better.

String.Format for Hex

If we have built in functions to convert your integer values to COLOR then why to worry.

string hexValue = string.Format("{0:X}", intColor);

Color brushes = System.Drawing.ColorTranslator.FromHtml("#"+hexValue);

equals vs Arrays.equals in Java

The equals() of arrays is inherited from Object, so it does not look at the contents of the arrrays, it only considers each array equal to itself.

The Arrays.equals() methods do compare the arrays' contents. There's overloads for all primitive types, and the one for objects uses the objects' own equals() methods.

How to redirect on another page and pass parameter in url from table?

Set the user name as data-username attribute to the button and also a class:


<input type="button" name="theButton" value="Detail" class="btn" data-username="{{result['username']}}" />


$(document).on('click', '.btn', function() {

    var name = $(this).data('username');        
    if (name != undefined && name != null) {
        window.location = '/player_detail?username=' + name;


Also, you can simply check for undefined && null using:

$(document).on('click', '.btn', function() {

    var name = $(this).data('username');        
    if (name) {
        window.location = '/player_detail?username=' + name;

As, mentioned in this answer

if (name) {            

will evaluate to true if value is not:

  • null
  • undefined
  • NaN
  • empty string ("")
  • 0
  • false

The above list represents all possible falsy values in ECMA/Javascript.

Looping through dictionary object

You can do it like this.

Models.TestModels obj = new Models.TestModels();
foreach (var item in obj.sp)

The problem you most likely have right now is that the collection is private. If you add public to the beginning of this line

Dictionary<int, dynamic> sp = new Dictionary<int, dynamic> 

You should be able to access it from the function inside your controller.

Edit: Adding functional example of the full TestModels implementation.

Your TestModels class should look something like this.

public class TestModels
    public Dictionary<int, dynamic> sp = new Dictionary<int, dynamic>();

    public TestModels()
        sp.Add(0, new {name="Test One", age=5});
        sp.Add(1, new {name="Test Two", age=7});

You probably want to read up on the dynamic keyword as well.