Programs & Examples On #Bitfoo

Which UUID version to use?

That's a very general question. One answer is: "it depends what kind of UUID you wish to generate". But a better one is this: "Well, before I answer, can you tell us why you need to code up your own UUID generation algorithm instead of calling the UUID generation functionality that most modern operating systems provide?"

Doing that is easier and safer, and since you probably don't need to generate your own, why bother coding up an implementation? In that case, the answer becomes use whatever your O/S, programming language or framework provides. For example, in Windows, there is CoCreateGuid or UuidCreate or one of the various wrappers available from the numerous frameworks in use. In Linux there is uuid_generate.

If you, for some reason, absolutely need to generate your own, then at least have the good sense to stay away from generating v1 and v2 UUIDs. It's tricky to get those right. Stick, instead, to v3, v4 or v5 UUIDs.

Update: In a comment, you mention that you are using Python and link to this. Looking through the interface provided, the easiest option for you would be to generate a v4 UUID (that is, one created from random data) by calling uuid.uuid4().

If you have some data that you need to (or can) hash to generate a UUID from, then you can use either v3 (which relies on MD5) or v5 (which relies on SHA1). Generating a v3 or v5 UUID is simple: first pick the UUID type you want to generate (you should probably choose v5) and then pick the appropriate namespace and call the function with the data you want to use to generate the UUID from. For example, if you are hashing a URL you would use NAMESPACE_URL:

uuid.uuid3(uuid.NAMESPACE_URL, 'https://ripple.com')

Please note that this UUID will be different than the v5 UUID for the same URL, which is generated like this:

uuid.uuid5(uuid.NAMESPACE_URL, 'https://ripple.com')

A nice property of v3 and v5 URLs is that they should be interoperable between implementations. In other words, if two different systems are using an implementation that complies with RFC4122, they will (or at least should) both generate the same UUID if all other things are equal (i.e. generating the same version UUID, with the same namespace and the same data). This property can be very helpful in some situations (especially in content-addressible storage scenarios), but perhaps not in your particular case.

Get clicked element using jQuery on event?

As simple as it can be

Use $(this) here too

$(document).on("click",".appDetails", function () {
   var clickedBtnID = $(this).attr('id'); // or var clickedBtnID = this.id
   alert('you clicked on button #' + clickedBtnID);
});

Bloomberg Open API

I don't think so. The API's will provide access to delayed quotes, there is no way that real time data or tick data, will be provided for free.

Mocking Logger and LoggerFactory with PowerMock and Mockito

The following is a test class that mocks private static final Logger named log in class LogUtil.

In addition to mocking the getLogger factory call, it is necessary to explicitly set the field using reflection, in @BeforeClass

public class LogUtilTest {

    private static Logger logger;

    private static MockedStatic<LoggerFactory> loggerFactoryMockedStatic;

    /**
     * Since {@link LogUtil#log} being a static final variable it is only initialized once at the class load time
     * So assertions are also performed against the same mock {@link LogUtilTest#logger}
     */
    @BeforeClass
    public static void beforeClass() {
        logger = mock(Logger.class);
        loggerFactoryMockedStatic = mockStatic(LoggerFactory.class);
        loggerFactoryMockedStatic.when(() -> LoggerFactory.getLogger(anyString())).thenReturn(logger);
        Whitebox.setInternalState(LogUtil.class, "log", logger);
    }

    @AfterClass
    public static void after() {
        loggerFactoryMockedStatic.close();
    }
} 

Change status bar color with AppCompat ActionBarActivity

I don't think the status bar color has been implemented in AppCompat yet. These are the attributes which are available:

    <!-- ============= -->
    <!-- Color palette -->
    <!-- ============= -->

    <!-- The primary branding color for the app. By default, this is the color applied to the
         action bar background. -->
    <attr name="colorPrimary" format="color" />

    <!-- Dark variant of the primary branding color. By default, this is the color applied to
         the status bar (via statusBarColor) and navigation bar (via navigationBarColor). -->
    <attr name="colorPrimaryDark" format="color" />

    <!-- Bright complement to the primary branding color. By default, this is the color applied
         to framework controls (via colorControlActivated). -->
    <attr name="colorAccent" format="color" />

    <!-- The color applied to framework controls in their normal state. -->
    <attr name="colorControlNormal" format="color" />

    <!-- The color applied to framework controls in their activated (ex. checked) state. -->
    <attr name="colorControlActivated" format="color" />

    <!-- The color applied to framework control highlights (ex. ripples, list selectors). -->
    <attr name="colorControlHighlight" format="color" />

    <!-- The color applied to framework buttons in their normal state. -->
    <attr name="colorButtonNormal" format="color" />

    <!-- The color applied to framework switch thumbs in their normal state. -->
    <attr name="colorSwitchThumbNormal" format="color" />

(From \sdk\extras\android\support\v7\appcompat\res\values\attrs.xml)

Basic HTTP authentication with Node and Express 4

I changed in express 4.0 the basic authentication with http-auth, the code is:

var auth = require('http-auth');

var basic = auth.basic({
        realm: "Web."
    }, function (username, password, callback) { // Custom authentication method.
        callback(username === "userName" && password === "password");
    }
);

app.get('/the_url', auth.connect(basic), routes.theRoute);

Java: How to convert List to Map

Apache Commons MapUtils.populateMap

If you don't use Java 8 and you don't want to use a explicit loop for some reason, try MapUtils.populateMap from Apache Commons.

MapUtils.populateMap

Say you have a list of Pairs.

List<ImmutablePair<String, String>> pairs = ImmutableList.of(
    new ImmutablePair<>("A", "aaa"),
    new ImmutablePair<>("B", "bbb")
);

And you now want a Map of the Pair's key to the Pair object.

Map<String, Pair<String, String>> map = new HashMap<>();
MapUtils.populateMap(map, pairs, new Transformer<Pair<String, String>, String>() {

  @Override
  public String transform(Pair<String, String> input) {
    return input.getKey();
  }
});

System.out.println(map);

gives output:

{A=(A,aaa), B=(B,bbb)}

That being said, a for loop is maybe easier to understand. (This below gives the same output):

Map<String, Pair<String, String>> map = new HashMap<>();
for (Pair<String, String> pair : pairs) {
  map.put(pair.getKey(), pair);
}
System.out.println(map);

Psql list all tables

This can be used in automation scripts if you don't need all tables in all schemas:

  for table in $(psql -qAntc '\dt' | cut -d\| -f2); do
      ...
  done

Installing PG gem on OS X - failure to build native extension

Same error for me and I didn't experience it until I downloaded OS X 10.9 (Mavericks). Sigh, another OS upgrade headache.

Here's how I fixed it (with homebrew):

  • Install another build of Xcode Tools (typing brew update in the terminal will prompt you to update the Xcode build tools)
  • brew update
  • brew install postgresql

After that gem install pg worked for me.

Determine if string is in list in JavaScript

I'm surprised no one had mentioned a simple function that takes a string and a list.

function in_list(needle, hay)
{
    var i, len;

    for (i = 0, len = hay.length; i < len; i++)
    {
        if (hay[i] == needle) { return true; }
    }

    return false;
}

var alist = ["test"];

console.log(in_list("test", alist));

Why does my sorting loop seem to append an element where it shouldn't?

Starting from Java 8, you can also use parallelSort which is useful if you have arrays containing a lot of elements.

Example:

public static void main(String[] args) {
    String[] strings = { "x", "a", "c", "b", "y" };
    Arrays.parallelSort(strings);
    System.out.println(Arrays.toString(strings));   // [a, b, c, x, y]
}

If you want to ignore the case, you can use:

public static void main(String[] args) {
    String[] strings = { "x", "a", "c", "B", "y" };
    Arrays.parallelSort(strings, new Comparator<String>() {
        @Override
        public int compare(String o1, String o2) {              
            return o1.compareToIgnoreCase(o2);
        }
    });
    System.out.println(Arrays.toString(strings));   // [a, B, c, x, y]
}

otherwise B will be before a.

If you want to ignore the trailing spaces during the comparison, you can use trim():

public static void main(String[] args) {
    String[] strings = { "x", "  a", "c ", " b", "y" };
    Arrays.parallelSort(strings, new Comparator<String>() {
        @Override
        public int compare(String o1, String o2) {              
            return o1.trim().compareTo(o2.trim());
        }
    });
    System.out.println(Arrays.toString(strings)); // [  a,  b, c , x, y]
}

See:

memory error in python

A memory error means that your program has ran out of memory. This means that your program somehow creates too many objects.

In your example, you have to look for parts of your algorithm that could be consuming a lot of memory. I suspect that your program is given very long strings as inputs. Therefore, s[i:j+1] could be the culprit, since it creates a new list. The first time you use it though, it is not necessary because you don't use the created list. You could try to see if the following helps:

if  j + 1 < a:
    sub_strings.append(s[i:j+1])

To replace the second list creation, you should definitely use a buffer object, as suggested by glglgl.

Also note that since you use if j >= i:, you don't need to start your xrange at 0. You can have:

for i in xrange(0, a):
    for j in xrange(i, a):
        # No need for if j >= i

A more radical alternative would be to try to rework your algorithm so that you don't pre-compute all possible sub-strings. Instead, you could simply compute the substring that are asked.

In STL maps, is it better to use map::insert than []?

A gotcha with map::insert() is that it won't replace a value if the key already exists in the map. I've seen C++ code written by Java programmers where they have expected insert() to behave the same way as Map.put() in Java where values are replaced.

Match groups in Python

You could create a helper function:

def re_match_group(pattern, str, out_groups):
    del out_groups[:]
    result = re.match(pattern, str)
    if result:
        out_groups[:len(result.groups())] = result.groups()
    return result

And then use it like this:

groups = []
if re_match_group("I love (\w+)", statement, groups):
    print "He loves", groups[0]
elif re_match_group("Ich liebe (\w+)", statement, groups):
    print "Er liebt", groups[0]
elif re_match_group("Je t'aime (\w+)", statement, groups):
    print "Il aime", groups[0]

It's a little clunky, but it gets the job done.

Can you blur the content beneath/behind a div?

If you want to enable unblur, you cannot just add the blur CSS to the body, you need to blur each visible child one level directly under the body and then remove the CSS to unblur. The reason is because of the "Cascade" in CSS, you cannot undo the cascading of the CSS blur effect for a child of the body. Also, to blur the body's background image you need to use the pseudo element :before

//HTML

<div id="fullscreen-popup" style="position:absolute;top:50%;left:50%;">
    <div class="morph-button morph-button-overlay morph-button-fixed">
        <button id="user-interface" type="button">MORE INFO</button>
        <!--a id="user-interface" href="javascript:void(0)">popup</a-->
        <div class="morph-content">
            <div>
                <div class="content-style-overlay">
                    <span class="icon icon-close">Close the overlay</span>
                    <h2>About Parsley</h2>
                    <p>Gumbo beet greens corn soko endive gumbo gourd. Parsley shallot courgette tatsoi pea sprouts fava bean collard greens dandelion okra wakame tomato. Dandelion cucumber earthnut pea peanut soko zucchini.</p>
                    <p>Turnip greens yarrow ricebean rutabaga endive cauliflower sea lettuce kohlrabi amaranth water spinach avocado daikon napa cabbage asparagus winter purslane kale. Celery potato scallion desert raisin horseradish spinach carrot soko. Lotus root water spinach fennel kombu maize bamboo shoot green bean swiss chard seakale pumpkin onion chickpea gram corn pea. Brussels sprout coriander water chestnut gourd swiss chard wakame kohlrabi beetroot carrot watercress. Corn amaranth salsify bunya nuts nori azuki bean chickweed potato bell pepper artichoke.</p>
                    <p>Gumbo beet greens corn soko endive gumbo gourd. Parsley shallot courgette tatsoi pea sprouts fava bean collard greens dandelion okra wakame tomato. Dandelion cucumber earthnut pea peanut soko zucchini.</p>
                    <p>Turnip greens yarrow ricebean rutabaga endive cauliflower sea lettuce kohlrabi amaranth water spinach avocado daikon napa cabbage asparagus winter purslane kale. Celery potato scallion desert raisin horseradish spinach carrot soko. Lotus root water spinach fennel kombu maize bamboo shoot green bean swiss chard seakale pumpkin onion chickpea gram corn pea. Brussels sprout coriander water chestnut gourd swiss chard wakame kohlrabi beetroot carrot watercress. Corn amaranth salsify bunya nuts nori azuki bean chickweed potato bell pepper artichoke.</p>
                    <p>Gumbo beet greens corn soko endive gumbo gourd. Parsley shallot courgette tatsoi pea sprouts fava bean collard greens dandelion okra wakame tomato. Dandelion cucumber earthnut pea peanut soko zucchini.</p>
                    <p>Turnip greens yarrow ricebean rutabaga endive cauliflower sea lettuce kohlrabi amaranth water spinach avocado daikon napa cabbage asparagus winter purslane kale. Celery potato scallion desert raisin horseradish spinach carrot soko. Lotus root water spinach fennel kombu maize bamboo shoot green bean swiss chard seakale pumpkin onion chickpea gram corn pea. Brussels sprout coriander water chestnut gourd swiss chard wakame kohlrabi beetroot carrot watercress. Corn amaranth salsify bunya nuts nori azuki bean chickweed potato bell pepper artichoke.</p>
                </div>
            </div>
        </div>
    </div>
</div>

//CSS

/* Blur - doesn't work on IE */

.blur-on, .blur-element {
    -webkit-filter: blur(10px);
    -moz-filter: blur(10px);
    -o-filter: blur(10px);
    -ms-filter: blur(10px);
    filter: blur(10px);

    -webkit-transition: all 5s linear;
    transition        : all 5s linear;
    -moz-transition   : all 5s linear;
    -webkit-transition: all 5s linear;
    -o-transition     : all 5s linear;
}
.blur-off {
    -webkit-filter: blur(0px) !important;
    -moz-filter   : blur(0px) !important;
    -o-filter     : blur(0px) !important;
    -ms-filter    : blur(0px) !important;
    filter        : blur(0px) !important;
}
.blur-bgimage:before {
    content: "";
    position: absolute;
    height: 20%; width: 20%;
    background-size: cover;
    background: inherit;
    z-index: -1;

    transform: scale(5);
    transform-origin: top left;
    filter: blur(2px);       
    -moz-transform: scale(5);
    -moz-transform-origin: top left;
    -moz-filter: blur(2px);       
    -webkit-transform: scale(5);
    -webkit-transform-origin: top left;
    -webkit-filter: blur(2px);
    -o-transform: scale(5);
    -o-transform-origin: top left;
    -o-filter: blur(2px);       

    transition        : all 5s linear;
    -moz-transition   : all 5s linear;
    -webkit-transition: all 5s linear;
    -o-transition     : all 5s linear;
}


//Javascript

function blurBehindPopup() {
    if(blurredElements.length == 0) {
        for(var i=0; i < document.body.children.length; i++) {
            var element = document.body.children[i];
            if(element.id && element.id != 'fullscreen-popup' && element.isVisible == true) {
                classie.addClass( element, 'blur-element' );
                blurredElements.push(element);
            }
        }
    } else {
        for(var i=0; i < blurredElements.length; i++) {
            classie.addClass( blurredElements[i], 'blur-element' );
        }
    }
}
function unblurBehindPopup() {
    for(var i=0; i < blurredElements.length; i++) {
        classie.removeClass( blurredElements[i], 'blur-element' );
    }
}

Full Working Example Link

python: urllib2 how to send cookie with urlopen request

Maybe using cookielib.CookieJar can help you. For instance when posting to a page containing a form:

import urllib2
import urllib
from cookielib import CookieJar

cj = CookieJar()
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj))
# input-type values from the html form
formdata = { "username" : username, "password": password, "form-id" : "1234" }
data_encoded = urllib.urlencode(formdata)
response = opener.open("https://page.com/login.php", data_encoded)
content = response.read()

EDIT:

After Piotr's comment I'll elaborate a bit. From the docs:

The CookieJar class stores HTTP cookies. It extracts cookies from HTTP requests, and returns them in HTTP responses. CookieJar instances automatically expire contained cookies when necessary. Subclasses are also responsible for storing and retrieving cookies from a file or database.

So whatever requests you make with your CookieJar instance, all cookies will be handled automagically. Kinda like your browser does :)

I can only speak from my own experience and my 99% use-case for cookies is to receive a cookie and then need to send it with all subsequent requests in that session. The code above handles just that, and it does so transparently.

Twitter Bootstrap Multilevel Dropdown Menu

This example is from http://bootsnipp.com/snippets/featured/multi-level-dropdown-menu-bs3

Works for me in Bootstrap v3.1.1.

HTML

<div class="container">
<div class="row">
    <h2>Multi level dropdown menu in Bootstrap 3</h2>
    <hr>
    <div class="dropdown">
        <a id="dLabel" role="button" data-toggle="dropdown" class="btn btn-primary" data-target="#" href="/page.html">
            Dropdown <span class="caret"></span>
        </a>
        <ul class="dropdown-menu multi-level" role="menu" aria-labelledby="dropdownMenu">
          <li><a href="#">Some action</a></li>
          <li><a href="#">Some other action</a></li>
          <li class="divider"></li>
          <li class="dropdown-submenu">
            <a tabindex="-1" href="#">Hover me for more options</a>
            <ul class="dropdown-menu">
              <li><a tabindex="-1" href="#">Second level</a></li>
              <li class="dropdown-submenu">
                <a href="#">Even More..</a>
                <ul class="dropdown-menu">
                    <li><a href="#">3rd level</a></li>
                    <li><a href="#">3rd level</a></li>
                </ul>
              </li>
              <li><a href="#">Second level</a></li>
              <li><a href="#">Second level</a></li>
            </ul>
          </li>
        </ul>
    </div>
</div>

CSS

.dropdown-submenu {
position: relative;
}

.dropdown-submenu>.dropdown-menu {
top: 0;
left: 100%;
margin-top: -6px;
margin-left: -1px;
-webkit-border-radius: 0 6px 6px 6px;
-moz-border-radius: 0 6px 6px;
border-radius: 0 6px 6px 6px;
}

.dropdown-submenu:hover>.dropdown-menu {
display: block;
}

.dropdown-submenu>a:after {
display: block;
content: " ";
float: right;
width: 0;
height: 0;
border-color: transparent;
border-style: solid;
border-width: 5px 0 5px 5px;
border-left-color: #ccc;
margin-top: 5px;
margin-right: -10px;
}

.dropdown-submenu:hover>a:after {
border-left-color: #fff;
}

.dropdown-submenu.pull-left {
float: none;
}

.dropdown-submenu.pull-left>.dropdown-menu {
left: -100%;
margin-left: 10px;
-webkit-border-radius: 6px 0 6px 6px;
-moz-border-radius: 6px 0 6px 6px;
border-radius: 6px 0 6px 6px;
}

Why .NET String is immutable?

Strings are passed as reference types in .NET.

Reference types place a pointer on the stack, to the actual instance that resides on the managed heap. This is different to Value types, who hold their entire instance on the stack.

When a value type is passed as a parameter, the runtime creates a copy of the value on the stack and passes that value into a method. This is why integers must be passed with a 'ref' keyword to return an updated value.

When a reference type is passed, the runtime creates a copy of the pointer on the stack. That copied pointer still points to the original instance of the reference type.

The string type has an overloaded = operator which creates a copy of itself, instead of a copy of the pointer - making it behave more like a value type. However, if only the pointer was copied, a second string operation could accidently overwrite the value of a private member of another class causing some pretty nasty results.

As other posts have mentioned, the StringBuilder class allows for the creation of strings without the GC overhead.

How do I escape double quotes in attributes in an XML String in T-SQL?

Cannot comment anymore but voted it up and wanted to let folks know that &quot; works very well for the xml config files when forming regex expressions for RegexTransformer in Solr like so: regex=".*img src=&quot;(.*)&quot;.*" using the escaped version instead of double-quotes.

Trying to use Spring Boot REST to Read JSON String from POST

The issue appears with parsing the JSON from request body, tipical for an invalid JSON. If you're using curl on windows, try escaping the json like -d "{"name":"value"}" or even -d "{"""name""":"value"""}"

On the other hand you can ommit the content-type header in which case whetewer is sent will be converted to your String argument

Difference in Months between two dates in JavaScript

below logic will fetch difference in months

(endDate.getFullYear()*12+endDate.getMonth())-(startDate.getFullYear()*12+startDate.getMonth())

Return Boolean Value on SQL Select Statement

DECLARE @isAvailable      BIT = 0;

IF EXISTS(SELECT 1  FROM [User] WHERE (UserID = 20070022))
BEGIN
 SET @isAvailable = 1
END

initially isAvailable boolean value is set to 0

Should we pass a shared_ptr by reference or by value?

I ran the code below, once with foo taking the shared_ptr by const& and again with foo taking the shared_ptr by value.

void foo(const std::shared_ptr<int>& p)
{
    static int x = 0;
    *p = ++x;
}

int main()
{
    auto p = std::make_shared<int>();
    auto start = clock();
    for (int i = 0; i < 10000000; ++i)
    {
        foo(p);
    }    
    std::cout << "Took " << clock() - start << " ms" << std::endl;
}

Using VS2015, x86 release build, on my intel core 2 quad (2.4GHz) processor

const shared_ptr&     - 10ms  
shared_ptr            - 281ms 

The copy by value version was an order of magnitude slower.
If you are calling a function synchronously from the current thread, prefer the const& version.

Python Pandas counting and summing specific conditions

You didn't mention the fancy indexing capabilities of dataframes, e.g.:

>>> df = pd.DataFrame({"class":[1,1,1,2,2], "value":[1,2,3,4,5]})
>>> df[df["class"]==1].sum()
class    3
value    6
dtype: int64
>>> df[df["class"]==1].sum()["value"]
6
>>> df[df["class"]==1].count()["value"]
3

You could replace df["class"]==1by another condition.

How can I remove or replace SVG content?

I had two charts.

<div id="barChart"></div>
<div id="bubbleChart"></div>

This removed all charts.

d3.select("svg").remove(); 

This worked for removing the existing bar chart, but then I couldn't re-add the bar chart after

d3.select("#barChart").remove();

Tried this. It not only let me remove the existing bar chart, but also let me re-add a new bar chart.

d3.select("#barChart").select("svg").remove();

var svg = d3.select('#barChart')
       .append('svg')
       .attr('width', width + margins.left + margins.right)
       .attr('height', height + margins.top + margins.bottom)
       .append('g')
       .attr('transform', 'translate(' + margins.left + ',' + margins.top + ')');

Not sure if this is the correct way to remove, and re-add a chart in d3. It worked in Chrome, but have not tested in IE.

Fast way to discover the row count of a table in PostgreSQL

In Oracle, you could use rownum to limit the number of rows returned. I am guessing similar construct exists in other SQLs as well. So, for the example you gave, you could limit the number of rows returned to 500001 and apply a count(*) then:

SELECT (case when cnt > 500000 then 500000 else cnt end) myCnt
FROM (SELECT count(*) cnt FROM table WHERE rownum<=500001)

Run bash script from Windows PowerShell

If you add the extension .SH to the environment variable PATHEXT, you will be able to run shell scripts from PowerShell by only using the script name with arguments:

PS> .\script.sh args

If you store your scripts in a directory that is included in your PATH environment variable, you can run it from anywhere, and omit the extension and path:

PS> script args

Note: sh.exe or another *nix shell must be associated with the .sh extension.

Pyinstaller setting icons don't change

I know this is old and whatnot (and not exactly sure if it's a question), but after searching, I had success with this command for --onefile:

pyinstaller.exe --onefile --windowed --icon=app.ico app.py

Google led me to this page while I was searching for an answer on how to set an icon for my .exe, so maybe it will help someone else.

The information here was found at this site: https://mborgerson.com/creating-an-executable-from-a-python-script

Element-wise addition of 2 lists?

This will work for 2 or more lists; iterating through the list of lists, but using numpy addition to deal with elements of each list

import numpy as np
list1=[1, 2, 3]
list2=[4, 5, 6]

lists = [list1, list2]
list_sum = np.zeros(len(list1))
for i in lists:
   list_sum += i
list_sum = list_sum.tolist()    

[5.0, 7.0, 9.0]

Correct owner/group/permissions for Apache 2 site files/folders under Mac OS X?

This is the most restrictive and safest way I've found, as explained here for hypothetical ~/my/web/root/ directory for your web content:

  • For each parent directory leading to your web root (e.g. ~/my, ~/my/web, ~/my/web/root):
    • chmod go-rwx DIR (nobody other than owner can access content)
    • chmod go+x DIR (to allow "users" including _www to "enter" the dir)
  • sudo chgrp -R _www ~/my/web/root (all web content is now group _www)
  • chmod -R go-rwx ~/my/web/root (nobody other than owner can access web content)
  • chmod -R g+rx ~/my/web/root (all web content is now readable/executable/enterable by _www)

All other solutions leave files open to other local users (who are part of the "staff" group as well as obviously being in the "o"/others group). These users may then freely browse and access DB configurations, source code, or other sensitive details in your web config files and scripts if such are part of your content. If this is not an issue for you, then by all means go with one of the simpler solutions.

How to create a DateTime equal to 15 minutes ago?

datetime.datetime.now() - datetime.timedelta(0, 15 * 60)

timedelta is a "change in time". It takes days as the first parameter and seconds in the second parameter. 15 * 60 seconds is 15 minutes.

Gradient text color

Example of CSS Text Gradient

background-image: -moz-linear-gradient(top,#E605C1 0%,#3B113B 100%);
background-image: -webkit-linear-gradient(top,#E605C1 0%,#3B113B 100%);
background-image: -o-linear-gradient(top,#E605C1 0%,#3B113B 100%);
background-image: -ms-linear-gradient(top,#E605C1 0%,#3B113B 100%);
background-image: linear-gradient(top,#E605C1 0%,#3B113B 100%);
-webkit-background-clip: text;
-webkit-text-fill-color: transparent;
position:relative;
display:inline-block; /*required*/

Online generator textgradient.com

Convert a JSON Object to Buffer and Buffer to JSON Object back

You need to stringify the json, not calling toString

var buf = Buffer.from(JSON.stringify(obj));

And for converting string to json obj :

var temp = JSON.parse(buf.toString());

Finding version of Microsoft C++ compiler from command-line (for makefiles)

Have a look at C++11 Features (Modern C++)

and section "Quick Reference Guide to Visual C++ Version Numbers" ...

How to only find files in a given directory, and ignore subdirectories using bash

This may do what you want:

find /dev \( ! -name /dev -prune \) -type f -print

Add disabled attribute to input element using Javascript

Just use jQuery's attr() method

$(this).closest("tr").next().show().find('.longboxsmall').attr('disabled', 'disabled');

Excel 2007 - Compare 2 columns, find matching values

You could fill the C Column with variations on the following formula:

=IF(ISERROR(MATCH(A1,$B:$B,0)),"",A1)

Then C would only contain values that were in A and C.

PHP Unset Session Variable

If you completely want to clear the session you can use this:

session_unset();
session_destroy();

Actually both are not neccessary but it does not hurt.

If you want to clear only a specific part I think you need this:

unset($_SESSION['Products']);
//or
$_SESSION['Products'] = "";

depending on what you need.

Python 'If not' syntax

Yes, if bar is not None is more explicit, and thus better, assuming it is indeed what you want. That's not always the case, there are subtle differences: if not bar: will execute if bar is any kind of zero or empty container, or False. Many people do use not bar where they really do mean bar is not None.

Get a list of resources from classpath directory

So in terms of the PathMatchingResourcePatternResolver this is what is needed in the code:

@Autowired
ResourcePatternResolver resourceResolver;

public void getResources() {
  resourceResolver.getResources("classpath:config/*.xml");
}

List of all users that can connect via SSH

Any user whose login shell setting in /etc/passwd is an interactive shell can login. I don't think there's a totally reliable way to tell if a program is an interactive shell; checking whether it's in /etc/shells is probably as good as you can get.

Other users can also login, but the program they run should not allow them to get much access to the system. And users that aren't allowed to login at all should have /etc/false as their shell -- this will just log them out immediately.

Resetting a form in Angular 2 after submit

I don't know if I'm on the right path, but I got it working on ng 2.4.8 with the following form/submit tags:

<form #heroForm="ngForm" (ngSubmit)="add(newHero); heroForm.reset()">
<!-- place your input stuff here -->
<button type="submit" class="btn btn-default" [disabled]="!heroForm.valid">Add hero</button>

Seems to do the trick and sets the form's fields to "pristine" again.

Oracle select most recent date record

i think i'd try with MAX something like this:

SELECT staff_id, max( date ) from owner.table group by staff_id

then link in your other columns:

select staff_id, site_id, pay_level, latest
from owner.table, 
(   SELECT staff_id, max( date ) latest from owner.table group by staff_id ) m
where m.staff_id = staff_id
and m.latest = date

How to implement an STL-style iterator and avoid common pitfalls?

I was/am in the same boat as you for different reasons (partly educational, partly constraints). I had to re-write all the containers of the standard library and the containers had to conform to the standard. That means, if I swap out my container with the stl version, the code would work the same. Which also meant that I had to re-write the iterators.

Anyway, I looked at EASTL. Apart from learning a ton about containers that I never learned all this time using the stl containers or through my undergraduate courses. The main reason is that EASTL is more readable than the stl counterpart (I found this is simply because of the lack of all the macros and straight forward coding style). There are some icky things in there (like #ifdefs for exceptions) but nothing to overwhelm you.

As others mentioned, look at cplusplus.com's reference on iterators and containers.

Reload parent window from child window

You can use window.opener, window.parent, or window.top to reference the window in question. From there, you just call the reload method (e.g.: window.parent.location.reload()).

However, as a caveat, you might have problems with window.opener if you need to navigate away from the originally opened page since the reference will be lost.

Python 3: ImportError "No Module named Setuptools"

Your setup.py file needs setuptools. Some Python packages used to use distutils for distribution, but most now use setuptools, a more complete package. Here is a question about the differences between them.

To install setuptools on Debian:

sudo apt-get install python3-setuptools

For an older version of Python (Python 2.x):

sudo apt-get install python-setuptools

How do I iterate and modify Java Sets?

I don't like very much iterator's semantic, please consider this as an option. It's also safer as you publish less of your internal state

private Map<String, String> JSONtoMAP(String jsonString) {

    JSONObject json = new JSONObject(jsonString);
    Map<String, String> outMap = new HashMap<String, String>();

    for (String curKey : (Set<String>) json.keySet()) {
        outMap.put(curKey, json.getString(curKey));
    }

    return outMap;

}

Rails 4 image-path, image-url and asset-url no longer work in SCSS files

I had a similar problem, trying to add a background image with inline css. No need to specify the images folder due to the way asset sync works.

This worked for me:

background-image: url('/assets/image.jpg');

How to post ASP.NET MVC Ajax form using JavaScript rather than submit button

I'm going to assume that your lack of quotes around the selector is just a transcription error, but you should check it anyway. Also, I don't see where you are actually giving the form an id. Usually you do this with the htmlAttributes parameter. I don't see you using the signature that has it. Again, though, if the form is submitting at all, this could be a transcription error.

If the selector and the id aren't the problem I'm suspicious that it might be because the click handler is added via markup when you use the Ajax BeginForm extension. You might try using $('form').trigger('submit') or in the worst case, have the click handler on the anchor create a hidden submit button in the form and click it. Or even create your own ajax submission using pure jQuery (which is probably what I would do).

Lastly, you should realize that by replacing the submit button, you're going to totally break this for people who don't have javascript enabled. The way around this is to also have a button hidden using a noscript tag and handle both AJAX and non-AJAX posts on the server.

BTW, it's consider standard practice, Microsoft not withstanding, to add the handlers via javascript not via markup. This keeps your javascript organized in one place so you can more easily see what's going on on the form. Here's an example of how I would use the trigger mechanism.

  $(function() {
      $('form#ajaxForm').find('a.submit-link').click( function() {
           $('form#ajaxForm').trigger('submit');
      }).show();
  }

<% using (Ajax.BeginForm("Update", "Description", new { id = Model.Id },
     new AjaxOptions
     {
       UpdateTargetId = "DescriptionDiv",
       HttpMethod = "post"
     }, new { id = "ajaxForm" } )) {%>
   Description:
   <%= Html.TextBox("Description", Model.Description) %><br />
   <a href="#" class="submit-link" style="display: none;">Save</a>
   <noscript>
       <input type="submit" value="Save" />
   </noscript>
<% } %>

How can I center <ul> <li> into div

Here is the solution I could find:

#wrapper {
  float:right;
  position:relative;
  left:-50%;
  text-align:left;
}
#wrapper ul {
  list-style:none;
  position:relative;
  left:50%;
}

#wrapper li{
  float:left;
  position:relative;
}

How can I select an element with multiple classes in jQuery?

your code $(".a, .b") will work for below multiple elements (at a same time)

<element class="a">
<element class="b">

if you want to select element having a and b both class like <element class="a b"> than use js without coma

$('.a.b')

How can I print out just the index of a pandas dataframe?

You can access the index attribute of a df using .index:

In [277]:

df = pd.DataFrame({'a':np.arange(10), 'b':np.random.randn(10)})
df
Out[277]:
   a         b
0  0  0.293422
1  1 -1.631018
2  2  0.065344
3  3 -0.417926
4  4  1.925325
5  5  0.167545
6  6 -0.988941
7  7 -0.277446
8  8  1.426912
9  9 -0.114189
In [278]:

df.index
Out[278]:
Int64Index([0, 1, 2, 3, 4, 5, 6, 7, 8, 9], dtype='int64')

How do I get the backtrace for all the threads in GDB?

Generally, the backtrace is used to get the stack of the current thread, but if there is a necessity to get the stack trace of all the threads, use the following command.

thread apply all bt

How to instantiate a javascript class in another js file?

// Create Customer class as follows:
export default class Customer {}

// Import the class 
// no need for .js extension in path cos gets inferred automatically
import Customer from './path/to/Customer'; 
// or
const Customer = require('./path/to/Customer') 

// Use the class
var customer = new Customer();
var name = customer.getName();

Linux command-line call not returning what it should from os.system?

The simplest way is like this:

import os
retvalue = os.popen("ps -p 2993 -o time --no-headers").readlines()
print retvalue

This will be returned as a list

How does the @property decorator work in Python?

property is a class behind @property decorator.

You can always check this:

print(property) #<class 'property'>

I rewrote the example from help(property) to show that the @property syntax

class C:
    def __init__(self):
        self._x=None

    @property 
    def x(self):
        return self._x

    @x.setter 
    def x(self, value):
        self._x = value

    @x.deleter
    def x(self):
        del self._x

c = C()
c.x="a"
print(c.x)

is functionally identical to property() syntax:

class C:
    def __init__(self):
        self._x=None

    def g(self):
        return self._x

    def s(self, v):
        self._x = v

    def d(self):
        del self._x

    prop = property(g,s,d)

c = C()
c.x="a"
print(c.x)

There is no difference how we use the property as you can see.

To answer the question @property decorator is implemented via property class.


So, the question is to explain the property class a bit. This line:

prop = property(g,s,d)

Was the initialization. We can rewrite it like this:

prop = property(fget=g,fset=s,fdel=d)

The meaning of fget, fset and fdel:

 |    fget
 |      function to be used for getting an attribute value
 |    fset
 |      function to be used for setting an attribute value
 |    fdel
 |      function to be used for del'ing an attribute
 |    doc
 |      docstring

The next image shows the triplets we have, from the class property:

enter image description here

__get__, __set__, and __delete__ are there to be overridden. This is the implementation of the descriptor pattern in Python.

In general, a descriptor is an object attribute with “binding behavior”, one whose attribute access has been overridden by methods in the descriptor protocol.

We can also use property setter, getter and deleter methods to bind the function to property. Check the next example. The method s2 of the class C will set the property doubled.

class C:
    def __init__(self):
        self._x=None

    def g(self):
        return self._x

    def s(self, x):
        self._x = x

    def d(self):
        del self._x

    def s2(self,x):
        self._x=x+x


    x=property(g)
    x=x.setter(s)
    x=x.deleter(d)      


c = C()
c.x="a"
print(c.x) # outputs "a"

C.x=property(C.g, C.s2)
C.x=C.x.deleter(C.d)
c2 = C()
c2.x="a"
print(c2.x) # outputs "aa"

How to convert SSH keypairs generated using PuTTYgen (Windows) into key-pairs used by ssh-agent and Keychain (Linux)

Alternatively if you want to grab the private and public keys from a PuTTY formated key file you can use puttygen on *nix systems. For most apt-based systems puttygen is part of the putty-tools package.

Outputting a private key from a PuTTY formated keyfile:

$ puttygen keyfile.pem -O private-openssh -o avdev.pvk

For the public key:

$ puttygen keyfile.pem -L

Error 5 : Access Denied when starting windows service

I don't know if my answer would make sense to many, but I too faced the same issue and the solution was outrageously simple. All I had to do was to open the program which I used to run the code as an administrator. (right-click --> Run as Administrator).

That was all.

The pipe ' ' could not be found angular2 custom pipe

If you see this error when running tests, make sure you have imported the module the pipe belongs to, e.g.:

    beforeEach(async(() => {
        TestBed.configureTestingModule({
            imports: [CustomPipeModule],
            declarations: [...],
            providers: [...],
            ...
        }).compileComponents();
    }));

How to run DOS/CMD/Command Prompt commands from VB.NET?

You Can try This To Run Command Then cmd Exits

Process.Start("cmd", "/c YourCode")

You Can try This To Run The Command And Let cmd Wait For More Commands

Process.Start("cmd", "/k YourCode")

Android Canvas.drawText

Worked this out, turns out that android.R.color.black is not the same as Color.BLACK. Changed the code to:

Paint paint = new Paint(); 
paint.setColor(Color.WHITE); 
paint.setStyle(Style.FILL); 
canvas.drawPaint(paint); 

paint.setColor(Color.BLACK); 
paint.setTextSize(20); 
canvas.drawText("Some Text", 10, 25, paint); 

and it all works fine now!!

Alternate background colors for list items

This is set background color on even and odd li:

  li:nth-child(odd) { background: #ffffff; }
  li:nth-child(even) { background: #80808030; }

MySQL: How to add one day to datetime field in query

Have a go with this, as this is how I would do it :)

SELECT * 
FROM fab_scheduler
WHERE custid = '123456'
AND CURDATE() = DATE(DATE_ADD(eventdate, INTERVAL 1 DAY))

How to set default values in Go structs

  1. Force a method to get the struct (the constructor way).

    From this post:

    A good design is to make your type unexported, but provide an exported constructor function like NewMyType() in which you can properly initialize your struct / type. Also return an interface type and not a concrete type, and the interface should contain everything others want to do with your value. And your concrete type must implement that interface of course.

    This can be done by simply making the type itself unexported. You can export the function NewSomething and even the fields Text and DefaultText, but just don't export the struct type something.

  2. Another way to customize it for you own module is by using a Config struct to set default values (Option 5 in the link). Not a good way though.

How to access the last value in a vector?

Combining lindelof's and Gregg Lind's ideas:

last <- function(x) { tail(x, n = 1) }

Working at the prompt, I usually omit the n=, i.e. tail(x, 1).

Unlike last from the pastecs package, head and tail (from utils) work not only on vectors but also on data frames etc., and also can return data "without first/last n elements", e.g.

but.last <- function(x) { head(x, n = -1) }

(Note that you have to use head for this, instead of tail.)

jQuery UI dialog box not positioned center screen

$("#dialog").dialog({
       autoOpen: false,
        height: "auto",
        width: "auto",
        modal: true,
         my: "center",
         at: "center",
         of: window
})

This solution does work but only because of the newer jQuery versions ignoring this completely and falling back to the default, which is exactly this. So you can just remove position: 'center' from your options if you just want the pop up to be centered.

How do I avoid the specification of the username and password at every git push?

Step 1 -

Create SSH keys on your linux system using below command

ssh-keygen -t rsa -b 4096 -C "your_email"

It will ask for passphrase and file name (default will be ~/.ssh/id_rsa, ~/.ssh/id_rsa.pub)

Step 2 -

Once files created add public key id_rsa.pub to github account ssh section.

Step 3 -

On your machine add private key id_rsa to ssh-agent using below command

ssh-add ~/.ssh/id_rsa 

Step 4 -

Now add remote url [email protected]:user_name/repo_name.git to your local git repo using below command.

git remote remove origin
git remote add origin [email protected]:user_name/repo_name.git

Thats it.

Using grep and sed to find and replace a string

Your solution is ok. only try it in this way:

files=$(grep -rl oldstr path) && echo $files | xargs sed....

so execute the xargs only when grep return 0, e.g. when found the string in some files.

Escape string Python for MySQL

One other way to work around this is using something like this when using mysqlclient in python.

suppose the data you want to enter is like this <ol><li><strong style="background-color: rgb(255, 255, 0);">Saurav\'s List</strong></li></ol>. It contains both double qoute and single quote.

You can use the following method to escape the quotes:

statement = """ Update chats set html='{}' """.format(html_string.replace("'","\\\'"))

Note: three \ characters are needed to escape the single quote which is there in unformatted python string.

Redirect non-www to www in .htaccess

Add the following code in .htaccess file.

RewriteCond %{HTTP_HOST} !^www\.
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]

URLs redirect tutorial can be found from here - Redirect non-www to www & HTTP to HTTPS using .htaccess file

Releasing memory in Python

First, you may want to install glances:

sudo apt-get install python-pip build-essential python-dev lm-sensors 
sudo pip install psutil logutils bottle batinfo https://bitbucket.org/gleb_zhulik/py3sensors/get/tip.tar.gz zeroconf netifaces pymdstat influxdb elasticsearch potsdb statsd pystache docker-py pysnmp pika py-cpuinfo bernhard
sudo pip install glances

Then run it in the terminal!

glances

In your Python code, add at the begin of the file, the following:

import os
import gc # Garbage Collector

After using the "Big" variable (for example: myBigVar) for which, you would like to release memory, write in your python code the following:

del myBigVar
gc.collect()

In another terminal, run your python code and observe in the "glances" terminal, how the memory is managed in your system!

Good luck!

P.S. I assume you are working on a Debian or Ubuntu system

Creating Duplicate Table From Existing Table

Use this query to create the new table with the values from existing table

CREATE TABLE New_Table_name AS SELECT * FROM Existing_table_Name; 

Now you can get all the values from existing table into newly created table.

Remove all items from a FormArray in Angular

Angular 8

simply use clear() method on formArrays :

(this.invoiceForm.controls['other_Partners'] as FormArray).clear();

How to normalize a vector in MATLAB efficiently? Any related built-in function?

I took Mr. Fooz's code and also added Arlen's solution too and here are the timings that I've gotten for Octave:

clc; clear all;
V = rand(1024*1024*32,1);
N = 10;
tic; for i=1:N, V1 = V/norm(V);         end; toc % 7.0 s
tic; for i=1:N, V2 = V/sqrt(sum(V.*V)); end; toc % 6.4 s
tic; for i=1:N, V3 = V/sqrt(V'*V);      end; toc % 5.5 s
tic; for i=1:N, V4 = V/sqrt(sum(V.^2)); end; toc % 6.6 s
tic; for i=1:N, V1 = V/norm(V);         end; toc % 7.1 s
tic; for i=1:N, d = 1/norm(V); V1 = V*d;end; toc % 4.7 s

Then, because of something I'm currently looking at, I tested out this code for ensuring that each row sums to 1:

clc; clear all;
m = 2048;
V = rand(m);
N = 100;
tic; for i=1:N, V1 = V ./ (sum(V,2)*ones(1,m));                end; toc % 8.2 s
tic; for i=1:N, V2 = bsxfun(@rdivide, V, sum(V,2));            end; toc % 5.8 s
tic; for i=1:N, V3 = bsxfun(@rdivide, V, V*ones(m,1));         end; toc % 5.7 s
tic; for i=1:N, V4 = V ./ (V*ones(m,m));                       end; toc % 77.5 s
tic; for i=1:N, d = 1./sum(V,2);V5 = bsxfun(@times, V, d);     end; toc % 2.83 s
tic; for i=1:N, d = 1./(V*ones(m,1));V6 = bsxfun(@times, V, d);end; toc % 2.75 s
tic; for i=1:N, V1 = V ./ (sum(V,2)*ones(1,m));                end; toc % 8.2 s

How can I store JavaScript variable output into a PHP variable?

If this is related to a form submission, use a hidden inputinside the form and change the hidden input value to this variable value. Then you can get that hidden input value in the php page and assign it to your php variable after form submission.

Update:

According to your edit, it seems you don't understand how javascript and php works. Javascript is a client side language, and php is a serverside language. Therefore you cannot execute javascript logic and use that variable value to a php variable when you execute relevant page in the server. You can run the relevant javascript logic after client browser process the web page returned from the web server (which has already executed the php code for the relevant page). After the execution of the javascript code and after assigning the relevant value to the relevant javascript variable, you can use form submission or ajax to send that javascript variable value to use by another php page (or a request to process and get the same php page).

Set LIMIT with doctrine 2?

$limit=5; // for exemple

$query = $this->getDoctrine()->getEntityManager()->createQuery(
           '// your request')

->setMaxResults($limit);

 $results = $query->getResult();

// Done

calculating execution time in c++

I have used the technique said above, still I found that the time given in the Code:Blocks IDE was more or less similar to the result obtained-(may be it will differ by little micro seconds)..

HQL ERROR: Path expected for join

select u from UserGroup ug inner join ug.user u 
where ug.group_id = :groupId 
order by u.lastname

As a named query:

@NamedQuery(
  name = "User.findByGroupId",
  query =
    "SELECT u FROM UserGroup ug " +
    "INNER JOIN ug.user u WHERE ug.group_id = :groupId ORDER BY u.lastname"
)

Use paths in the HQL statement, from one entity to the other. See the Hibernate documentation on HQL and joins for details.

How can I convert tabs to spaces in every file of a directory?

You can use find with tabs-to-spaces package for this.

First, install tabs-to-spaces

npm install -g tabs-to-spaces

then, run this command from the root directory of your project;

find . -name '*' -exec t2s --spaces 2 {} \;

This will replace every tab character with 2 spaces in every file.

How to view kafka message

Old version includes kafka-simple-consumer-shell.sh (https://kafka.apache.org/downloads#1.1.1) which is convenient since we do not need cltr+c to exit.

For example

kafka-simple-consumer-shell.sh --broker-list $BROKERIP:$BROKERPORT --topic $TOPIC1 --property print.key=true --property key.separator=":"  --no-wait-at-logend

How can I change the current URL?

Simple assigning to window.location or window.location.href should be fine:

window.location = newUrl;

However, your new URL will cause the browser to load the new page, but it sounds like you'd like to modify the URL without leaving the current page. You have two options for this:

  1. Use the URL hash. For example, you can go from example.com to example.com#foo without loading a new page. You can simply set window.location.hash to make this easy. Then, you should listen to the HTML5 hashchange event, which will be fired when the user presses the back button. This is not supported in older versions of IE, but check out jQuery BBQ, which makes this work in all browsers.

  2. You could use HTML5 History to modify the path without reloading the page. This will allow you to change from example.com/foo to example.com/bar. Using this is easy:

    window.history.pushState("example.com/foo");

    When the user presses "back", you'll receive the window's popstate event, which you can easily listen to (jQuery):

    $(window).bind("popstate", function(e) { alert("location changed"); });

    Unfortunately, this is only supported in very modern browsers, like Chrome, Safari, and the Firefox 4 beta.

angular js unknown provider

Make sure your main app.js includes the services on which it depends. For example:

/* App Module */
angular.module('myApp', ['productServices']). 
.....

Eloquent - where not equal to

Use where with a != operator in combination with whereNull

Code::where('to_be_used_by_user_id', '!=' , 2)->orWhereNull('to_be_used_by_user_id')->get()

clearing a char array c

void clearArray (char *input[]){
    *input = ' '; 
}

Git submodule head 'reference is not a tree' error

To sync the git repo with the submodule's head, in case that is really what you want, I found that removing the submodule and then readding it avoids the tinkering with the history. Unfortunately removing a submodule requires hacking rather than being a single git command, but doable.

Steps I followed to remove the submodule, inspired by https://gist.github.com/kyleturner/1563153:

  1. Run git rm --cached
  2. Delete the relevant lines from the .gitmodules file.
  3. Delete the relevant section from .git/config.
  4. Delete the now untracked submodule files.
  5. Remove directory .git/modules/

Again, this can be useful if all you want is to point at the submodule's head again, and you haven't complicated things by needing to keep the local copy of the submodule intact. It assumes you have the submodule "right" as its own repo, wherever the origin of it is, and you just want to get back to properly including it as a submodule.

Note: always make a full copy of your project before engaging in these kinds of manipulation or any git command beyond simple commit or push. I'd advise that with all other answers as well, and as a general git guideline.

How to download file from database/folder using php

I have changed to your code with little modification will works well. Here is the code:

butangDonload.php

<?php
$file = "logo_ldg.png"; //Let say If I put the file name Bang.png
echo "<a href='download1.php?nama=".$file."'>download</a> ";
?>

download.php

<?php
$name= $_GET['nama'];

    header('Content-Description: File Transfer');
    header('Content-Type: application/force-download');
    header("Content-Disposition: attachment; filename=\"" . basename($name) . "\";");
    header('Content-Transfer-Encoding: binary');
    header('Expires: 0');
    header('Cache-Control: must-revalidate');
    header('Pragma: public');
    header('Content-Length: ' . filesize($name));
    ob_clean();
    flush();
    readfile("your_file_path/".$name); //showing the path to the server where the file is to be download
    exit;
?>

Here you need to show the path from where the file to be download. i.e. will just give the file name but need to give the file path for reading that file. So, it should be replaced by I have tested by using your code and modifying also will works.

Unable to allocate array with shape and data type

Sometimes, this error pops up because of the kernel has reached its limit. Try to restart the kernel redo the necessary steps.

Cannot set property 'display' of undefined

document.getElementsByClassName('btn-pageMenu') delivers a nodeList. You should use: document.getElementsByClassName('btn-pageMenu')[0].style.display (if it's the first element from that list you want to change.

If you want to change style.display for all nodes loop through the list:

var elems = document.getElementsByClassName('btn-pageMenu');
for (var i=0;i<elems.length;i+=1){
  elems[i].style.display = 'block';
}

to be complete: if you use jquery it is as simple as:

?$('.btn-pageMenu').css('display'???????????????????????????,'block');??????

Default session timeout for Apache Tomcat applications

Open $CATALINA_BASE/conf/web.xml and find this

<!-- ==================== Default Session Configuration ================= -->
<!-- You can set the default session timeout (in minutes) for all newly   -->
<!-- created sessions by modifying the value below.                       -->

<session-config>
  <session-timeout>30</session-timeout>
</session-config>

all webapps implicitly inherit from this default web descriptor. You can override session-config as well as other settings defined there in your web.xml.

This is actually from my Tomcat 7 (Windows) but I think 5.5 conf is not very different

What are callee and caller saved registers?

I'm not really sure if this adds anything but,

Caller saved means that the caller has to save the registers because they will be clobbered in the call and have no choice but to be left in a clobbered state after the call returns (for instance, the return value being in eax for cdecl. It makes no sense for the return value to be restored to the value before the call by the callee, because it is a return value).

Callee saved means that the callee has to save the registers and then restore them at the end of the call because they have the guarantee to the caller of containing the same values after the function returns, and it is possible to restore them, even if they are clobbered at some point during the call.

The issue with the above definition though is that for instance on Wikipedia cdecl, it says eax, ecx and edx are caller saved and rest are callee saved, this suggests that the caller must save all 3 of these registers, when it might not if none of these registers were used by the caller in the first place. In which case caller 'saved' becomes a misnomer, but 'call clobbered' still correctly applies. This is the same with 'the rest' being called callee saved. It implies that all other x86 registers will be saved and restored by the callee when this is not the case if some of the registers are never used in the call anyway. With cdecl, eax:edx may be used to return a 64 bit value. I'm not sure why ecx is also caller saved if needed, but it is.

What key shortcuts are to comment and uncomment code?

Use the keys CtrlK,C to comment out the line and CtrlK,U to uncomment the line.

Check if a specific value exists at a specific key in any subarray of a multidimensional array

function checkMultiArrayValue($array) {
        global $test;
        foreach ($array as $key => $item) {

            if(!empty($item) && is_array($item)) {
                checkMultiArrayValue($item);
            }else {
                if($item)
                 $test[$key] = $item;

            }
        }
        return $test;   
    }

 $multiArray = array(    
                0 =>  array(  
                      "country"   => "",  
                      "price"    => 4,  
                      "discount-price" => 0,  
               ),);

$test = checkMultiArrayValue($multiArray);
echo "<pre>"
print_r($test);

Will return array who have index and value

Regex to get string between curly braces

/\{([^}]+)\}/

/        - delimiter
\{       - opening literal brace escaped because it is a special character used for quantifiers eg {2,3}
(        - start capturing
[^}]     - character class consisting of
    ^    - not
    }    - a closing brace (no escaping necessary because special characters in a character class are different)
+        - one or more of the character class
)        - end capturing
\}       - the closing literal brace
/        - delimiter

Difference between __getattr__ vs __getattribute__

In reading through Beazley & Jones PCB, I have stumbled on an explicit and practical use-case for __getattr__ that helps answer the "when" part of the OP's question. From the book:

"The __getattr__() method is kind of like a catch-all for attribute lookup. It's a method that gets called if code tries to access an attribute that doesn't exist." We know this from the above answers, but in PCB recipe 8.15, this functionality is used to implement the delegation design pattern. If Object A has an attribute Object B that implements many methods that Object A wants to delegate to, rather than redefining all of Object B's methods in Object A just to call Object B's methods, define a __getattr__() method as follows:

def __getattr__(self, name):
    return getattr(self._b, name)

where _b is the name of Object A's attribute that is an Object B. When a method defined on Object B is called on Object A, the __getattr__ method will be invoked at the end of the lookup chain. This would make code cleaner as well, since you do not have a list of methods defined just for delegating to another object.

ImportError: No module named - Python

Make sure if root project directory is coming up in sys.path output. If not, please add path of root project directory to sys.path.

In Angular, how do you determine the active route?

I solved a problem I encountered in this link and I find out that there is a simple solution for your question. You could use router-link-active instead in your styles.

@Component({
   styles: [`.router-link-active { background-color: red; }`]
})
export class NavComponent {
}

MVC : The parameters dictionary contains a null entry for parameter 'k' of non-nullable type 'System.Int32'

It seems that your action needs k but ModelBinder can not find it (from form, or request or view data or ..) Change your action to this:

public ActionResult DetailsData(int? k)
    {

        EmployeeContext Ec = new EmployeeContext();
        if (k != null)
        {
           Employee emp = Ec.Employees.Single(X => X.EmpId == k.Value);

           return View(emp);
        }
        return View();
    }

SUM of grouped COUNT in SQL Query

You can use union to joining rows.

select Name, count(*) as Count from yourTable group by Name
union all
select "SUM" as Name, count(*) as Count from yourTable

In a Django form, how do I make a field readonly (or disabled) so that it cannot be edited?

Setting readonly on a widget only makes the input in the browser read-only. Adding a clean_sku which returns instance.sku ensures the field value will not change on form level.

def clean_sku(self):
    if self.instance: 
        return self.instance.sku
    else: 
        return self.fields['sku']

This way you can use model's (unmodified save) and avoid getting the field required error.

In PHP, what is a closure and why does it use the "use" identifier?

closures are beautiful! they solve a lot of problems that come with anonymous functions, and make really elegant code possible (at least as long as we talk about php).

javascript programmers use closures all the time, sometimes even without knowing it, because bound variables aren't explicitly defined - that's what "use" is for in php.

there are better real-world examples than the above one. lets say you have to sort an multidimensional array by a sub-value, but the key changes.

<?php
    function generateComparisonFunctionForKey($key) {
        return function ($left, $right) use ($key) {
            if ($left[$key] == $right[$key])
                return 0;
            else
                return ($left[$key] < $right[$key]) ? -1 : 1;
        };
    }

    $myArray = array(
        array('name' => 'Alex', 'age' => 70),
        array('name' => 'Enrico', 'age' => 25)
    );

    $sortByName = generateComparisonFunctionForKey('name');
    $sortByAge  = generateComparisonFunctionForKey('age');

    usort($myArray, $sortByName);

    usort($myArray, $sortByAge);
?>

warning: untested code (i don't have php5.3 installed atm), but it should look like something like that.

there's one downside: a lot of php developers may be a bit helpless if you confront them with closures.

to understand the nice-ty of closures more, i'll give you another example - this time in javascript. one of the problems is the scoping and the browser inherent asynchronity. especially, if it comes to window.setTimeout(); (or -interval). so, you pass a function to setTimeout, but you can't really give any parameters, because providing parameters executes the code!

function getFunctionTextInASecond(value) {
    return function () {
        document.getElementsByName('body')[0].innerHTML = value; // "value" is the bound variable!
    }
}

var textToDisplay = prompt('text to show in a second', 'foo bar');

// this returns a function that sets the bodys innerHTML to the prompted value
var myFunction = getFunctionTextInASecond(textToDisplay);

window.setTimeout(myFunction, 1000);

myFunction returns a function with a kind-of predefined parameter!

to be honest, i like php a lot more since 5.3 and anonymous functions/closures. namespaces may be more important, but they're a lot less sexy.

Add Bootstrap Glyphicon to Input Box

Here's a CSS-only alternative. I set this up for a search field to get an effect similar to Firefox (& a hundred other apps.)

Here's a fiddle.

HTML

<div class="col-md-4">
  <input class="form-control" type="search" />
  <span class="glyphicon glyphicon-search"></span>
</div>

CSS

.form-control {
  padding-right: 30px;
}

.form-control + .glyphicon {
  position: absolute;
  right: 0;
  padding: 8px 27px;
}

Change user-agent for Selenium web-driver

There is no way in Selenium to read the request or response headers. You could do it by instructing your browser to connect through a proxy that records this kind of information.

Setting the User Agent in Firefox

The usual way to change the user agent for Firefox is to set the variable "general.useragent.override" in your Firefox profile. Note that this is independent from Selenium.

You can direct Selenium to use a profile different from the default one, like this:

from selenium import webdriver
profile = webdriver.FirefoxProfile()
profile.set_preference("general.useragent.override", "whatever you want")
driver = webdriver.Firefox(profile)

Setting the User Agent in Chrome

With Chrome, what you want to do is use the user-agent command line option. Again, this is not a Selenium thing. You can invoke Chrome at the command line with chrome --user-agent=foo to set the agent to the value foo.

With Selenium you set it like this:

from selenium import webdriver
from selenium.webdriver.chrome.options import Options
opts = Options()
opts.add_argument("user-agent=whatever you want")

driver = webdriver.Chrome(chrome_options=opts)

Both methods above were tested and found to work. I don't know about other browsers.

Getting the User Agent

Selenium does not have methods to query the user agent from an instance of WebDriver. Even in the case of Firefox, you cannot discover the default user agent by checking what general.useragent.override would be if not set to a custom value. (This setting does not exist before it is set to some value.)

Once the browser is started, however, you can get the user agent by executing:

agent = driver.execute_script("return navigator.userAgent")

The agent variable will contain the user agent.

How to extract a string using JavaScript Regex?

Your regular expression most likely wants to be

/\nSUMMARY:(.*)$/g

A helpful little trick I like to use is to default assign on match with an array.

var arr = iCalContent.match(/\nSUMMARY:(.*)$/g) || [""]; //could also use null for empty value
return arr[0];

This way you don't get annoying type errors when you go to use arr

How do I import a .dmp file into Oracle?

i got solution what you are getting as per imp help=y it is mentioned that imp is only valid for TRANSPORT_TABLESPACE as below:

Keyword  Description (Default)       Keyword      Description (Default)
--------------------------------------------------------------------------
USERID   username/password           FULL         import entire file (N)
BUFFER   size of data buffer         FROMUSER     list of owner usernames
FILE     input files (EXPDAT.DMP)    TOUSER       list of usernames
SHOW     just list file contents (N) TABLES       list of table names
IGNORE   ignore create errors (N)    RECORDLENGTH length of IO record
GRANTS   import grants (Y)           INCTYPE      incremental import type
INDEXES  import indexes (Y)          COMMIT       commit array insert (N)
ROWS     import data rows (Y)        PARFILE      parameter filename
LOG      log file of screen output   CONSTRAINTS  import constraints (Y)
DESTROY                overwrite tablespace data file (N)
INDEXFILE              write table/index info to specified file
SKIP_UNUSABLE_INDEXES  skip maintenance of unusable indexes (N)
FEEDBACK               display progress every x rows(0)
TOID_NOVALIDATE        skip validation of specified type ids
FILESIZE               maximum size of each dump file
STATISTICS             import precomputed statistics (always)
RESUMABLE              suspend when a space related error is encountered(N)
RESUMABLE_NAME         text string used to identify resumable statement
RESUMABLE_TIMEOUT      wait time for RESUMABLE
COMPILE                compile procedures, packages, and functions (Y)
STREAMS_CONFIGURATION  import streams general metadata (Y)
STREAMS_INSTANTIATION  import streams instantiation metadata (N)
DATA_ONLY              import only data (N)

The following keywords only apply to transportable tablespaces
TRANSPORT_TABLESPACE import transportable tablespace metadata (N)
TABLESPACES tablespaces to be transported into database
DATAFILES datafiles to be transported into database
TTS_OWNERS users that own data in the transportable tablespace set

So, Please create table space for your user:

CREATE TABLESPACE <tablespace name> DATAFILE <path to save, example: 'C:\ORACLEXE\APP\ORACLE\ORADATA\XE\ABC.dbf'> SIZE 100M AUTOEXTEND ON NEXT 100M MAXSIZE 10G EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1M;

C++ calling base class constructors

The short answer for this is, "because that's what the C++ standard specifies".

Note that you can always specify a constructor that's different from the default, like so:

class Shape  {

  Shape()  {...} //default constructor
  Shape(int h, int w) {....} //some custom constructor


};

class Rectangle : public Shape {
  Rectangle(int h, int w) : Shape(h, w) {...} //you can specify which base class constructor to call

}

The default constructor of the base class is called only if you don't specify which one to call.

Unable to set default python version to python3 in ubuntu

Just follow these steps to help change the default python to the newly upgrade python version. Worked well for me.

  • sudo apt-install python3.7 Install the latest version of python you want
  • cd /usr/bin Enter the root directory where python is installed
  • sudo unlink python or sudo unlink python3 . Unlink the current default python
  • sudo ln -sv /usr/bin/python3.7 python Link the new downloaded python version
  • python --version Check the new python version and you're good to go

Get all LI elements in array

You can get a NodeList to iterate through by using getElementsByTagName(), like this:

var lis = document.getElementById("navbar").getElementsByTagName("li");

You can test it out here. This is a NodeList not an array, but it does have a .length and you can iterate over it like an array.

Getting return value from stored procedure in C#

There are multiple problems here:

  1. It is not possible. You are trying to return a varchar. Stored procedure return values can only be integer expressions. See official RETURN documentation: https://msdn.microsoft.com/en-us/library/ms174998.aspx.
  2. Your sqlcomm was never executed. You have to call sqlcomm.ExecuteNonQuery(); in order to execute your command.

Here is a solution using OUTPUT parameters. This was tested with:

  • Windows Server 2012
  • .NET v4.0.30319
  • C# 4.0
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER PROCEDURE [dbo].[Validate]
    @a varchar(50),
    @b varchar(50) OUTPUT
AS
BEGIN
    DECLARE @b AS varchar(50) = (SELECT Password FROM dbo.tblUser WHERE Login = @a)
    SELECT @b;
END
SqlConnection SqlConn = ...
var sqlcomm = new SqlCommand("Validate", SqlConn);

string returnValue = string.Empty;

try
{
    SqlConn.Open();
    sqlcomm.CommandType = CommandType.StoredProcedure;

    SqlParameter param = new SqlParameter("@a", SqlDbType.VarChar);
    param.Direction = ParameterDirection.Input;
    param.Value = Username;
    sqlcomm.Parameters.Add(param);

    SqlParameter output = sqlcomm.Parameters.Add("@b", SqlDbType.VarChar);
    ouput.Direction = ParameterDirection.Output;

    sqlcomm.ExecuteNonQuery(); // This line was missing

    returnValue = output.Value.ToString();

    // ... the rest of code

} catch (SqlException ex) {
    throw ex;
}

ReadFile in Base64 Nodejs

Latest and greatest way to do this:

Node supports file and buffer operations with the base64 encoding:

const fs = require('fs');
const contents = fs.readFileSync('/path/to/file.jpg', {encoding: 'base64'});

Or using the new promises API:

const fs = require('fs').promises;
const contents = await fs.readFile('/path/to/file.jpg', {encoding: 'base64'});

How can I make my layout scroll both horizontally and vertically?

You can do this by using below code

<HorizontalScrollView
                    android:layout_width="match_parent"
                    android:layout_height="match_parent">
                    <ScrollView
                        android:layout_width="wrap_content"
                        android:layout_height="match_parent">
                        <LinearLayout
                            android:layout_width="match_parent"
                            android:layout_height="wrap_content">
                            
                        </LinearLayout>
                    </ScrollView>
    </HorizontalScrollView>

Could not resolve '...' from state ''

Had the same issue with Ionic routing.

Simple solution is to use the name of the state - basically state.go(state name)

.state('tab.search', {
    url: '/search',
    views: {
      'tab-search': {
        templateUrl: 'templates/search.html',
        controller: 'SearchCtrl'
      }
    }
  })

And in controller you can use $state.go('tab.search');

Adjust width and height of iframe to fit with content in it

Context

I had to do this myself in a context of a web-extension. This web-extension injects some piece of UI into each page, and this UI lives inside an iframe. The content inside the iframe is dynamic, so I had to readjust the width and height of the iframe itself.

I use React but the concept applies to every library.

My solution (this assumes that you control both the page and the iframe)

Inside the iframe I changed body styles to have really big dimensions. This will allow the elements inside to lay out using all the necessary space. Making width and height 100% didn't work for me (I guess because the iframe has a default width = 300px and height = 150px)

/* something like this */
body {
  width: 99999px;
  height: 99999px;
}

Then I injected all the iframe UI inside a div and gave it some styles

#ui-root {
  display: 'inline-block';     
}

After rendering my app inside this #ui-root (in React I do this inside componentDidMount) I compute the dimensions of this div like and sync them to the parent page using window.postMessage:

let elRect = el.getBoundingClientRect()
window.parent.postMessage({
  type: 'resize-iframe',
  payload: {
    width: elRect.width,
    height: elRect.height
  }
}, '*')

In the parent frame I do something like this:

window.addEventListener('message', (ev) => {
  if(ev.data.type && ev.data.type === 'resize-iframe') {
    iframe.style.width = ev.data.payload.width + 'px'
    iframe.style.height = ev.data.payload.height + 'px'
  }
}, false)

What is the equivalent of "none" in django templates?

You can also use another built-in template default_if_none

{{ profile.user.first_name|default_if_none:"--" }}

VBScript -- Using error handling

I'm exceptionally new to VBScript, so this may not be considered best practice or there may be a reason it shouldn't be done this that way I'm not yet aware of, but this is the solution I came up with to trim down the amount of error logging code in my main code block.

Dim oConn, connStr
Set oConn = Server.CreateObject("ADODB.Connection")
connStr = "Provider=SQLOLEDB;Server=XX;UID=XX;PWD=XX;Databse=XX"

ON ERROR RESUME NEXT

oConn.Open connStr
If err.Number <> 0 Then : showError() : End If


Sub ShowError()

    'You could write the error details to the console...
    errDetail = "<script>" & _
    "console.log('Description: " & err.Description & "');" & _
    "console.log('Error number: " & err.Number & "');" & _
    "console.log('Error source: " & err.Source & "');" & _
    "</script>"

    Response.Write(errDetail)       

    '...you could display the error info directly in the page...
    Response.Write("Error Description: " & err.Description)
    Response.Write("Error Source: " & err.Source)
    Response.Write("Error Number: " & err.Number)

    '...or you could execute additional code when an error is thrown...
    'Insert error handling code here

    err.clear
End Sub

How do you disable the unused variable warnings coming out of gcc in 3rd party code I do not wish to edit?

The compiler is already telling you, it's not value but variable. You are looking for -Wno-unused-variable. Also, try g++ --help=warnings to see a list of available options.

Capturing mobile phone traffic on Wireshark

For Android, I previously used tPacketCapture but it didn't work well for an app streaming some video. I'm now using Shark. You need to be root to use it though.

It uses TCPDump (check the arguments you can pass) and creates a pcap file that can be read by Wireshark. The default arguments are usually good enough for me.

How to set array length in c# dynamically

InputProperty[] ip = new InputProperty[nvPairs.Length]; 

Or, you can use a list like so:

List<InputProperty> list = new List<InputProperty>();
InputProperty ip = new (..);
list.Add(ip);
update.items = list.ToArray();

Another thing I'd like to point out, in C# you can delcare your int variable use in a for loop right inside the loop:

for(int i = 0; i<nvPairs.Length;i++
{
.
.
}

And just because I'm in the mood, here's a cleaner way to do this method IMO:

private Update BuildMetaData(MetaData[] nvPairs)
{
        Update update = new Update();
        var ip = new List<InputProperty>();

        foreach(var nvPair in nvPairs)
        {
            if (nvPair == null) break;
            var inputProp = new InputProperty
            {
               Name = "udf:" + nvPair.Name,
               Val = nvPair.Value
            };
            ip.Add(inputProp);
        }
        update.Items = ip.ToArray();
        return update;
}

add elements to object array

You can try

Subject[] subjects = new Subject[2];
subjects[0] = new Subject{....};
subjects[1] = new Subject{....};

alternatively you can use List

List<Subject> subjects = new List<Subject>();
subjects.add(new Subject{....});
subjects.add(new Subject{....});

Babel command not found

To install version 7+ of Babel run:

npm install -g @babel/cli
npm install -g @babel/core

converting multiple columns from character to numeric format in r

like this?

DF <- data.frame("a" = as.character(0:5),
             "b" = paste(0:5, ".1", sep = ""),
             "c" = paste(10:15),
             stringsAsFactors = FALSE)

DF <- apply(DF, 2, as.numeric)

If there are "real" characters in dataframe like 'a' 'b' 'c', i would recommend answer from davsjob.

Jquery $(this) Child Selector

In the click event "this" is the a tag that was clicked

jQuery('.class1 a').click( function() {
   var divToSlide = $(this).parent().find(".class2");
   if (divToSlide.is(":hidden")) {
      divToSlide.slideDown("slow");
   } else {
      divToSlide.slideUp();
   }
});

There's multiple ways to get to the div though you could also use .siblings, .next etc

Call php function from JavaScript

I recently published a jQuery plugin which allows you to make PHP function calls in various ways: https://github.com/Xaxis/jquery.php

Simple example usage:

// Both .end() and .data() return data to variables
var strLenA = P.strlen('some string').end();
var strLenB = P.strlen('another string').end();
var totalStrLen = strLenA + strLenB;
console.log( totalStrLen ); // 25

// .data Returns data in an array
var data1 = P.crypt("Some Crypt String").data();
console.log( data1 ); // ["$1$Tk1b01rk$shTKSqDslatUSRV3WdlnI/"]

Angular update object in object array

Updating directly the item passed as argument should do the job, but I am maybe missing something here ?

updateItem(item){
  this.itemService.getUpdate(item.id)
  .subscribe(updatedItem => {
    item = updatedItem;
  });
}

EDIT : If you really have no choice but to loop through your entire array to update your item, use findIndex :

let itemIndex = this.items.findIndex(item => item.id == retrievedItem.id);
this.items[itemIndex] = retrievedItem;

Today`s date in an excel macro

Here's an example that puts the Now() value in column A.

Sub move()
    Dim i As Integer
    Dim sh1 As Worksheet
    Dim sh2 As Worksheet
    Dim nextRow As Long
    Dim copyRange As Range
    Dim destRange As Range

    Application.ScreenUpdating = False

        Set sh1 = ActiveWorkbook.Worksheets("Sheet1")
        Set sh2 = ActiveWorkbook.Worksheets("Sheet2")
        Set copyRange = sh1.Range("A1:A5")

        i = Application.WorksheetFunction.CountA(sh2.Range("B:B")) + 4

        Set destRange = sh2.Range("B" & i)

        destRange.Resize(1, copyRange.Rows.Count).Value = Application.Transpose(copyRange.Value)
        destRange.Offset(0, -1).Value = Format(Now(), "MMM-DD-YYYY")

        copyRange.Clear

    Application.ScreenUpdating = True

End Sub

There are better ways of getting the last row in column B than using a While loop, plenty of examples around here. Some are better than others but depend on what you're doing and what your worksheet structure looks like. I used one here which assumes that column B is ALL empty except the rows/records you're moving. If that's not the case, or if B1:B3 have some values in them, you'd need to modify or use another method. Or you could just use your loop, but I'd search for alternatives :)

How to call another components function in angular2

  • Lets say 1st component is DbstatsMainComponent
  • 2nd component DbstatsGraphComponent.
  • 1st component calling the method of 2nd

<button (click)="dbgraph.displayTableGraph()">Graph</button> <dbstats-graph #dbgraph></dbstats-graph>

Note the local variable #dbgraph on the child component, which the parent can use to access its methods (dbgraph.displayTableGraph()).

Can I inject a service into a directive in AngularJS?

You can do injection on Directives, and it looks just like it does everywhere else.

app.directive('changeIt', ['myData', function(myData){
    return {
        restrict: 'C',
        link: function (scope, element, attrs) {
            scope.name = myData.name;
        }
    }
 }]);

Sorting an Array of int using BubbleSort

You need two loops to implement the Bubble Sort .

Sample code :

public static void bubbleSort(int[] numArray) {

    int n = numArray.length;
    int temp = 0;

    for (int i = 0; i < n; i++) {
        for (int j = 1; j < (n - i); j++) {

            if (numArray[j - 1] > numArray[j]) {
                temp = numArray[j - 1];
                numArray[j - 1] = numArray[j];
                numArray[j] = temp;
            }

        }
    }
}

Batch file: Find if substring is in string (not in a file)

I usually do something like this:

Echo.%1 | findstr /C:"%2">nul && (
    REM TRUE
) || (
    REM FALSE
)

Example:

Echo.Hello world | findstr /C:"world">nul && (
    Echo.TRUE
) || (
    Echo.FALSE
)

Echo.Hello world | findstr /C:"World">nul && (Echo.TRUE) || (Echo.FALSE)

Output:

TRUE
FALSE

I don't know if this is the best way.

Use jquery to set value of div tag

When using the .html() method, a htmlString must be the parameter. (source) Put your string inside a HTML tag and it should work or use .text() as suggested by farzad.

Example:

<div class="demo-container">
    <div class="demo-box">Demonstration Box</div>
</div>

<script type="text/javascript">
$("div.demo-container").html( "<p>All new content. <em>You bet!</em></p>" );
</script>

Best dynamic JavaScript/JQuery Grid

Have a look at agiletoolkit.org as this has a simple to use CRUD which supports 2,4,6,7,9,10 and 12 out of the box (uses Ajax to defender the grid when adding,deleting data and it integrates with jquery.

I would post some examples but on an iPad at the moment.

HTML how to clear input using javascript?

<script type="text/javascript">
    function clearThis(target){
        if (target.value === "[email protected]") {
            target.value= "";
        }
    }
    </script>
<input type="text" name="email" value="[email protected]" size="30" onfocus="clearThis(this)">

Try it out here: http://jsfiddle.net/2K3Vp/

How do I create a chart with multiple series using different X values for each series?

You need to use the Scatter chart type instead of Line. That will allow you to define separate X values for each series.

How to create a scrollable Div Tag Vertically?

This code creates a nice vertical scrollbar for me in Firefox and Chrome:

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#answerform {
  position: absolute;
  border: 5px solid gray;
  padding: 5px;
  background: white;
  width: 300px;
  height: 400px;
  overflow-y: scroll;
}
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<div id='answerform'>
  badger<br><br>badger<br><br>badger<br><br>badger<br><br>badger<br><br> mushroom
  <br><br>mushroom<br><br> a badger<br><br>badger<br><br>badger<br><br>badger<br><br>badger<br><br>
</div>
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_x000D_
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Here is a JS fiddle demo proving the above works.

How can I solve ORA-00911: invalid character error?

I encountered the same thing lately. it was just due to spaces when copying a script from a document to sql developer. I had to remove the spaces and the script ran.

Oracle SQL: Update a table with data from another table

Try this:

MERGE INTO table1 t1
USING
(
-- For more complicated queries you can use WITH clause here
SELECT * FROM table2
)t2
ON(t1.id = t2.id)
WHEN MATCHED THEN UPDATE SET
t1.name = t2.name,
t1.desc = t2.desc;

How to populate/instantiate a C# array with a single value?

You can use Array.Fill in .NET Core 2.0+ and .NET Standard 2.1+.

Python one-line "for" expression

If you really only need to add the items in one array to another, the '+' operator is already overloaded to do that, incidentally:

a1 = [1,2,3,4,5]
a2 = [6,7,8,9]
a1 + a2
--> [1, 2, 3, 4, 5, 6, 7, 8, 9]

Linq to Sql: Multiple left outer joins

I am using this linq query for my application. if this match your requirement you can refer this. here i have joined(Left outer join) with 3 tables.

 Dim result = (From csL In contractEntity.CSLogin.Where(Function(cs) cs.Login = login AndAlso cs.Password = password).DefaultIfEmpty
                   From usrT In contractEntity.UserType.Where(Function(uTyp) uTyp.UserTypeID = csL.UserTyp).DefaultIfEmpty ' <== makes join left join
                   From kunD In contractEntity.EmployeeMaster.Where(Function(kunDat) kunDat.CSLoginID = csL.CSLoginID).DefaultIfEmpty
                   Select New With {
                  .CSLoginID = csL.CSLoginID,
                  .UserType = csL.UserTyp}).ToList()

Getting the Facebook like/share count for a given URL

UPDATE: This solution is no longer valid. FQLs are deprecated since August 7th, 2016.


https://api.facebook.com/method/fql.query?query=select%20%20like_count%20from%20link_stat%20where%20url=%22http://www.techlila.com%22

Also http://api.facebook.com/restserver.php?method=links.getStats&urls=http://www.techlila.com will show you all the data like 'Share Count', 'Like Count' and 'Comment Count' and total of all these.

Change the URL (i.e. http://www.techlila.com) as per your need.

This is the correct URL, I'm getting right results.

EDIT (May 2017): as of v2.9 you can make a graph API call where ID is the URL and select the 'engagement' field, below is a link with the example from the graph explorer.

https://developers.facebook.com/tools/explorer/?method=GET&path=%3Fid%3Dhttp%3A%2F%2Fcomunidade.edp.pt%26fields%3Dengagement&version=v2.9

How to add include and lib paths to configure/make cycle?

This took a while to get right. I had this issue when cross-compiling in Ubuntu for an ARM target. I solved it with:

PATH=$PATH:/ccpath/bin CC=ccname-gcc AR=ccname-ar LD=ccname-ld CPPFLAGS="-nostdinc -I/ccrootfs/usr/include ..." LDFLAGS=-L/ccrootfs/usr/lib ./autogen.sh --build=`config.guess` --host=armv5tejl-unknown-linux-gnueabihf

Notice CFLAGS is not used with autogen.sh/configure, using it gave me the error: "configure: error: C compiler cannot create executables". In the build environment I was using an autogen.sh script was provided, if you don't have an autogen.sh script substitute ./autogen.sh with ./configure in the command above. I ran config.guess on the target system to get the --host parameter.

After successfully running autogen.sh/configure, compile with:

PATH=$PATH:/ccpath/bin CC=ccname-gcc AR=ccname-ar LD=ccname-ld CPPFLAGS="-nostdinc -I/ccrootfs/usr/include ..." LDFLAGS=-L/ccrootfs/usr/lib CFLAGS="-march=... -mcpu=... etc." make

The CFLAGS I chose to use were: "-march=armv5te -fno-tree-vectorize -mthumb-interwork -mcpu=arm926ej-s". It will take a while to get all of the include directories set up correctly: you might want some includes pointing to your cross-compiler and some pointing to your root file system includes, and there will likely be some conflicts.

I'm sure this is not the perfect answer. And I am still seeing some include directories pointing to / and not /ccrootfs in the Makefiles. Would love to know how to correct this. Hope this helps someone.

Calculating Time Difference

You cannot calculate the differences separately ... what difference would that yield for 7:59 and 8:00 o'clock? Try

import time
time.time()

which gives you the seconds since the start of the epoch.

You can then get the intermediate time with something like

timestamp1 = time.time()
# Your code here
timestamp2 = time.time()
print "This took %.2f seconds" % (timestamp2 - timestamp1)

Trim specific character from a string

One line is enough:

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var x = '|f|oo||';
var y = x.replace(/^\|+|\|+$/g, '');
document.write(x + '<br />' + y);
_x000D_
_x000D_
_x000D_

^\|+   beginning of the string, pipe, one or more times
|      or
\|+$   pipe, one or more times, end of the string

A general solution:

_x000D_
_x000D_
function trim (s, c) {
  if (c === "]") c = "\\]";
  if (c === "\\") c = "\\\\";
  return s.replace(new RegExp(
    "^[" + c + "]+|[" + c + "]+$", "g"
  ), "");
}

chars = ".|]\\";
for (c of chars) {
  s = c + "foo" + c + c + "oo" + c + c + c;
  console.log(s, "->", trim(s, c));
}
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How to save a git commit message from windows cmd?

With the atom editor, you just need to install the git-plus package.

How to change proxy settings in Android (especially in Chrome)

Found one solution for WIFI (works for Android 4.3, 4.4):

  1. Connect to WIFI network (e.g. 'Alex')
  2. Settings->WIFI
  3. Long tap on connected network's name (e.g. on 'Alex')
  4. Modify network config-> Show advanced options
  5. Set proxy settings

Using :after to clear floating elements

Use

.wrapper:after {
    content : '\n';
}

Much like solution provided by Roko. It allows to insert/change content using : after and :before psuedo. For details check http://www.quirksmode.org/css/content.html

Sort columns of a dataframe by column name

Similar to other syntax above but for learning - can you sort by column names?

sort(colnames(test[1:ncol(test)] ))

How to prevent SIGPIPEs (or handle them properly)

In this post I described possible solution for Solaris case when neither SO_NOSIGPIPE nor MSG_NOSIGNAL is available.

Instead, we have to temporarily suppress SIGPIPE in the current thread that executes library code. Here's how to do this: to suppress SIGPIPE we first check if it is pending. If it does, this means that it is blocked in this thread, and we have to do nothing. If the library generates additional SIGPIPE, it will be merged with the pending one, and that's a no-op. If SIGPIPE is not pending then we block it in this thread, and also check whether it was already blocked. Then we are free to execute our writes. When we are to restore SIGPIPE to its original state, we do the following: if SIGPIPE was pending originally, we do nothing. Otherwise we check if it is pending now. If it does (which means that out actions have generated one or more SIGPIPEs), then we wait for it in this thread, thus clearing its pending status (to do this we use sigtimedwait() with zero timeout; this is to avoid blocking in a scenario where malicious user sent SIGPIPE manually to a whole process: in this case we will see it pending, but other thread may handle it before we had a change to wait for it). After clearing pending status we unblock SIGPIPE in this thread, but only if it wasn't blocked originally.

Example code at https://github.com/kroki/XProbes/blob/1447f3d93b6dbf273919af15e59f35cca58fcc23/src/libxprobes.c#L156

Difference between the System.Array.CopyTo() and System.Array.Clone()

Both perform shallow copies as @PatrickDesjardins said (despite the many misled souls who think that CopyTo does a deep copy).

However, CopyTo allows you to copy one array to a specified index in the destination array, giving it significantly more flexibility.

Android Button Onclick

There are two solutions for this are :-

(1) do not put onClick in xml

(2) remove

button.setOnClickListener(new OnClickListener() {
    public void onClick(View v) {
            // TODO Auto-generated method stub
    }
});

and put

public void setLogin(View v) {
    // Your code here
}

SHA-1 fingerprint of keystore certificate

As of Sept 2020, if you want to get the SHA-1 fingerprint of keystore certificate of Release. Simply open up your Google Play Developer Console and open the App Signing tab.

enter image description here

Windows service with timer

You need to put your main code on the OnStart method.

This other SO answer of mine might help.

You will need to put some code to enable debugging within visual-studio while maintaining your application valid as a windows-service. This other SO thread cover the issue of debugging a windows-service.

EDIT:

Please see also the documentation available here for the OnStart method at the MSDN where one can read this:

Do not use the constructor to perform processing that should be in OnStart. Use OnStart to handle all initialization of your service. The constructor is called when the application's executable runs, not when the service runs. The executable runs before OnStart. When you continue, for example, the constructor is not called again because the SCM already holds the object in memory. If OnStop releases resources allocated in the constructor rather than in OnStart, the needed resources would not be created again the second time the service is called.

When is it acceptable to call GC.Collect?

If you have good reason to believe that a significant set of objects - particularly those you suspect to be in generations 1 and 2 - are now eligible for garbage collection, and that now would be an appropriate time to collect in terms of the small performance hit.

A good example of this is if you've just closed a large form. You know that all the UI controls can now be garbage collected, and a very short pause as the form is closed probably won't be noticeable to the user.

UPDATE 2.7.2018

As of .NET 4.5 - there is GCLatencyMode.LowLatency and GCLatencyMode.SustainedLowLatency. When entering and leaving either of these modes, it is recommended that you force a full GC with GC.Collect(2, GCCollectionMode.Forced).

As of .NET 4.6 - there is the GC.TryStartNoGCRegion method (used to set the read-only value GCLatencyMode.NoGCRegion). This can itself, perform a full blocking garbage collection in an attempt to free enough memory, but given we are disallowing GC for a period, I would argue it is also a good idea to perform full GC before and after.

Source: Microsoft engineer Ben Watson's: Writing High-Performance .NET Code, 2nd Ed. 2018.

See:

Java. Implicit super constructor Employee() is undefined. Must explicitly invoke another constructor

This problem can also come up when you don't have your constructor immediately call super.

So this will work:

  public Employee(String name, String number, Date date)
  {
    super(....)
  }

But this won't:

  public Employee(String name, String number, Date date)
  {
    // an example of *any* code running before you call super.
    if (number < 5)
    {
       number++;
    }

    super(....)
  }

The reason the 2nd example fails is because java is trying to implicitely call

super(name,number,date)

as the first line in your constructor.... So java doesn't see that you've got a call to super going on later in the constructor. It essentially tries to do this:

  public Employee(String name, String number, Date date)
  {
    super(name, number, date);

    if (number < 5)
    {
       number++;
    }

    super(....)
  }

So the solution is pretty easy... Just don't put code before your super call ;-) If you need to initialize something before the call to super, do it in another constructor, and then call the old constructor... Like in this example pulled from this StackOverflow post:

public class Foo
{
    private int x;

    public Foo()
    {
        this(1);
    }

    public Foo(int x)
    {
        this.x = x;
    }
}

Remove NaN from pandas series

>>> s = pd.Series([1,2,3,4,np.NaN,5,np.NaN])
>>> s[~s.isnull()]
0    1
1    2
2    3
3    4
5    5

update or even better approach as @DSM suggested in comments, using pandas.Series.dropna():

>>> s.dropna()
0    1
1    2
2    3
3    4
5    5

Which JRE am I using?

 System.out.println(System.getProperty("java.vendor"));
 System.out.println(System.getProperty("java.vendor.url"));
 System.out.println(System.getProperty("java.version"));

 Sun Microsystems Inc.
 http://java.sun.com/
 1.6.0_11

http://docs.oracle.com/javase/tutorial/essential/environment/sysprop.html

Deadly CORS when http://localhost is the origin

The solution is to install an extension that lifts the block that Chrome does, for example:

Access Control-Allow-Origin - Unblock (https://add0n.com/access-control.html?version=0.1.5&type=install).

In PowerShell, how can I test if a variable holds a numeric value?

If you want to check if a string has a numeric value, use this code:

$a = "44.4"
$b = "ad"
$rtn = ""
[double]::TryParse($a,[ref]$rtn)
[double]::TryParse($b,[ref]$rtn)

Credits go here

Using Pipes within ngModel on INPUT Elements in Angular

because of two way binding, To prevent error of:

ExpressionChangedAfterItHasBeenCheckedError: Expression has changed after it was 
checked.

you can call a function to change model like this:

<input [ngModel]="item.value" 
  (ngModelChange)="getNewValue($event)" name="inputField" type="text" />


import { UseMyPipeToFormatThatValuePipe } from './path';

constructor({
    private UseMyPipeToFormatThatValue: UseMyPipeToFormatThatValuePipe,
})

getNewValue(ev: any): any {
    item.value= this.useMyPipeToFormatThatValue.transform(ev);
}

it'll be good if there is a better solution to prevent this error.

Using classes with the Arduino

Can you provide an example of what did not work? As you likely know, the Wiring language is based on C/C++, however, not all of C++ is supported.

Whether you are allowed to create classes in the Wiring IDE, I'm not sure (my first Arduino is in the mail right now). I do know that if you wrote a C++ class, compiled it using AVR-GCC, then loaded it on your Arduino using AVRDUDE, it would work.

How to iterate over associative arrays in Bash

Welcome to input associative array 2.0!

    clear
    echo "Welcome to input associative array 2.0! (Spaces in keys and values now supported)"
    unset array
    declare -A array
    read -p 'Enter number for array size: ' num
    for (( i=0; i < num; i++ ))
        do
            echo -n "(pair $(( $i+1 )))"
            read -p ' Enter key: ' k
            read -p '         Enter value: ' v
            echo " "
            array[$k]=$v
        done
    echo " "
    echo "The keys are: " ${!array[@]}
    echo "The values are: " ${array[@]}
    echo " "
    echo "Key <-> Value"
    echo "-------------"
    for i in "${!array[@]}"; do echo $i "<->" ${array[$i]}; done
    echo " "
    echo "Thanks for using input associative array 2.0!"

Output:

Welcome to input associative array 2.0! (Spaces in keys and values now supported)
Enter number for array size: 4
(pair 1) Enter key: Key Number 1
         Enter value: Value#1

(pair 2) Enter key: Key Two
         Enter value: Value2

(pair 3) Enter key: Key3
         Enter value: Val3

(pair 4) Enter key: Key4
         Enter value: Value4


The keys are:  Key4 Key3 Key Number 1 Key Two
The values are:  Value4 Val3 Value#1 Value2

Key <-> Value
-------------
Key4 <-> Value4
Key3 <-> Val3
Key Number 1 <-> Value#1
Key Two <-> Value2

Thanks for using input associative array 2.0!

Input associative array 1.0

(keys and values that contain spaces are not supported)

    clear
    echo "Welcome to input associative array! (written by mO extraordinaire!)"
    unset array
    declare -A array
    read -p 'Enter number for array size: ' num
    for (( i=0; i < num; i++ ))
        do
            read -p 'Enter key and value separated by a space: ' k v
            array[$k]=$v
        done
    echo " "
    echo "The keys are: " ${!array[@]}
    echo "The values are: " ${array[@]}
    echo " "
    echo "Key <-> Value"
    echo "-------------"
    for i in ${!array[@]}; do echo $i "<->" ${array[$i]}; done
    echo " "
    echo "Thanks for using input associative array!"

Output:

Welcome to input associative array! (written by mO extraordinaire!)
Enter number for array size: 10
Enter key and value separated by a space: a1 10
Enter key and value separated by a space: b2 20
Enter key and value separated by a space: c3 30
Enter key and value separated by a space: d4 40
Enter key and value separated by a space: e5 50
Enter key and value separated by a space: f6 60
Enter key and value separated by a space: g7 70
Enter key and value separated by a space: h8 80
Enter key and value separated by a space: i9 90
Enter key and value separated by a space: j10 100

The keys are:  h8 a1 j10 g7 f6 e5 d4 c3 i9 b2
The values are:  80 10 100 70 60 50 40 30 90 20

Key <-> Value
-------------
h8 <-> 80
a1 <-> 10
j10 <-> 100
g7 <-> 70
f6 <-> 60
e5 <-> 50
d4 <-> 40
c3 <-> 30
i9 <-> 90
b2 <-> 20

Thanks for using input associative array!

What is the difference between `new Object()` and object literal notation?

I have found one difference, for ES6/ES2015. You cannot return an object using the shorthand arrow function syntax, unless you surround the object with new Object().

> [1, 2, 3].map(v => {n: v});
[ undefined, undefined, undefined ]
> [1, 2, 3].map(v => new Object({n: v}));
[ { n: 1 }, { n: 2 }, { n: 3 } ]

This is because the compiler is confused by the {} brackets and thinks n: i is a label: statement construct; the semicolon is optional so it doesn't complain about it.

If you add another property to the object it will finally throw an error.

$ node -e "[1, 2, 3].map(v => {n: v, m: v+1});"
[1, 2, 3].map(v => {n: v, m: v+1});
                           ^

SyntaxError: Unexpected token :

Check if certain value is contained in a dataframe column in pandas

You can use any:

print any(df.column == 07311954)
True       #true if it contains the number, false otherwise

If you rather want to see how many times '07311954' occurs in a column you can use:

df.column[df.column == 07311954].count()

How to add images to README.md on GitHub?

Consider using a table if adding multiple screenshots and want to align them using tabular data for improved accessibility as shown here:

high-tea

If your markdown parser supports it you could also add the role="presentation" WIA-ARIA attribute to the TABLE element and omit the th tags.

How to check variable type at runtime in Go language

quux00's answer only tells about comparing basic types.

If you need to compare types you defined, you shouldn't use reflect.TypeOf(xxx). Instead, use reflect.TypeOf(xxx).Kind().

There are two categories of types:

  • direct types (the types you defined directly)
  • basic types (int, float64, struct, ...)

Here is a full example:

type MyFloat float64
type Vertex struct {
    X, Y float64
}

type EmptyInterface interface {}

type Abser interface {
    Abs() float64
}

func (v Vertex) Abs() float64 {
    return math.Sqrt(v.X*v.X + v.Y*v.Y)
}

func (f MyFloat) Abs() float64 {
    return math.Abs(float64(f))
}

var ia, ib Abser
ia = Vertex{1, 2}
ib = MyFloat(1)
fmt.Println(reflect.TypeOf(ia))
fmt.Println(reflect.TypeOf(ia).Kind())
fmt.Println(reflect.TypeOf(ib))
fmt.Println(reflect.TypeOf(ib).Kind())

if reflect.TypeOf(ia) != reflect.TypeOf(ib) {
    fmt.Println("Not equal typeOf")
}
if reflect.TypeOf(ia).Kind() != reflect.TypeOf(ib).Kind() {
    fmt.Println("Not equal kind")
}

ib = Vertex{3, 4}
if reflect.TypeOf(ia) == reflect.TypeOf(ib) {
    fmt.Println("Equal typeOf")
}
if reflect.TypeOf(ia).Kind() == reflect.TypeOf(ib).Kind() {
    fmt.Println("Equal kind")
}

The output would be:

main.Vertex
struct
main.MyFloat
float64
Not equal typeOf
Not equal kind
Equal typeOf
Equal kind

As you can see, reflect.TypeOf(xxx) returns the direct types which you might want to use, while reflect.TypeOf(xxx).Kind() returns the basic types.


Here's the conclusion. If you need to compare with basic types, use reflect.TypeOf(xxx).Kind(); and if you need to compare with self-defined types, use reflect.TypeOf(xxx).

if reflect.TypeOf(ia) == reflect.TypeOf(Vertex{}) {
    fmt.Println("self-defined")
} else if reflect.TypeOf(ia).Kind() == reflect.Float64 {
    fmt.Println("basic types")
}

How should I choose an authentication library for CodeIgniter?

Maybe you'd find Redux suiting your needs. It's no overkill and comes packed solely with bare features most of us would require. The dev and contributors were very strict on what code was contributed.

This is the official page

Count work days between two dates

 DECLARE @TotalDays INT,@WorkDays INT
 DECLARE @ReducedDayswithEndDate INT
 DECLARE @WeekPart INT
 DECLARE @DatePart INT

 SET @TotalDays= DATEDIFF(day, @StartDate, @EndDate) +1
 SELECT @ReducedDayswithEndDate = CASE DATENAME(weekday, @EndDate)
  WHEN 'Saturday' THEN 1
  WHEN 'Sunday' THEN 2
  ELSE 0 END 
 SET @TotalDays=@TotalDays-@ReducedDayswithEndDate
 SET @WeekPart=@TotalDays/7;
 SET @DatePart=@TotalDays%7;
 SET @WorkDays=(@WeekPart*5)+@DatePart

 RETURN @WorkDays

How do I parse a URL into hostname and path in javascript?

freddiefujiwara's answer is pretty good but I also needed to support relative URLs within Internet Explorer. I came up with the following solution:

function getLocation(href) {
    var location = document.createElement("a");
    location.href = href;
    // IE doesn't populate all link properties when setting .href with a relative URL,
    // however .href will return an absolute URL which then can be used on itself
    // to populate these additional fields.
    if (location.host == "") {
      location.href = location.href;
    }
    return location;
};

Now use it to get the needed properties:

var a = getLocation('http://example.com/aa/bb/');
document.write(a.hostname);
document.write(a.pathname);

Example:

_x000D_
_x000D_
function getLocation(href) {
  var location = document.createElement("a");
  location.href = href;
  // IE doesn't populate all link properties when setting .href with a relative URL,
  // however .href will return an absolute URL which then can be used on itself
  // to populate these additional fields.
  if (location.host == "") {
    location.href = location.href;
  }
  return location;
};
var urlToParse = 'http://example.com/aa/bb/',
  a = getLocation(urlToParse);
document.write('Absolute URL: ' + urlToParse);
document.write('<br />');
document.write('Hostname: ' + a.hostname);
document.write('<br />');
document.write('Pathname: ' + a.pathname);
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Create a pointer to two-dimensional array

You can always avoid fiddling around with the compiler by declaring the array as linear and doing the (row,col) to array index calculation by yourself.

static uint8_t l_matrix[200];

void test(int row, int col, uint8_t val)

{

   uint8_t* matrix_ptr = l_matrix;
   matrix_ptr [col+y*row] = val; // to assign a value

}

this is what the compiler would have done anyway.

How to make <a href=""> link look like a button?

Just take regular css button designs, and apply that CSS to a link (in exactly the same way as you would to a button).

Example:

<a href="#" class="stylish-button">Some words</a>

<style type="text/css">
.stylish-button {
    -webkit-box-shadow:rgba(0,0,0,0.2) 0 1px 0 0;
    -moz-box-shadow:rgba(0,0,0,0.2) 0 1px 0 0;
    box-shadow:rgba(0,0,0,0.2) 0 1px 0 0;
    color:#333;
    background-color:#FA2;
    border-radius:5px;
    -moz-border-radius:5px;
    -webkit-border-radius:5px;
    border:none;
    font-size:16px;
    font-weight:700;
    padding:4px 16px;
    text-shadow:#FE6 0 1px 0
}
</style>

Class is not abstract and does not override abstract method

If you're trying to take advantage of polymorphic behavior, you need to ensure that the methods visible to outside classes (that need polymorphism) have the same signature. That means they need to have the same name, number and order of parameters, as well as the parameter types.

In your case, you might do better to have a generic draw() method, and rely on the subclasses (Rectangle, Ellipse) to implement the draw() method as what you had been thinking of as "drawEllipse" and "drawRectangle".

Appending an element to the end of a list in Scala

This is similar to one of the answers but in different way :

scala> val x = List(1,2,3)
x: List[Int] = List(1, 2, 3)

scala> val y = x ::: 4 :: Nil
y: List[Int] = List(1, 2, 3, 4)

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.).

Dump a NumPy array into a csv file

if you want to write in column:

    for x in np.nditer(a.T, order='C'): 
            file.write(str(x))
            file.write("\n")

Here 'a' is the name of numpy array and 'file' is the variable to write in a file.

If you want to write in row:

    writer= csv.writer(file, delimiter=',')
    for x in np.nditer(a.T, order='C'): 
            row.append(str(x))
    writer.writerow(row)

Docker: How to use bash with an Alpine based docker image?

RUN /bin/sh -c "apk add --no-cache bash"

worked for me.

C# HttpWebRequest of type "application/x-www-form-urlencoded" - how to send '&' character in content body?

Since your content-type is application/x-www-form-urlencoded you'll need to encode the POST body, especially if it contains characters like & which have special meaning in a form.

Try passing your string through HttpUtility.UrlEncode before writing it to the request stream.

Here are a couple links for reference.

How to update a value, given a key in a hashmap?

One line solution:

map.put(key, map.containsKey(key) ? map.get(key) + 1 : 1);

bootstrap datepicker change date event doesnt fire up when manually editing dates or clearing date

In version 2.1.5

changeDate has been renamed to change.dp so changedate was not working for me

$("#datetimepicker").datetimepicker().on('change.dp', function (e) {
            FillDate(new Date());
    });

also needed to change css class from datepicker to datepicker-input

<div id='datetimepicker' class='datepicker-input input-group controls'>
   <input id='txtStartDate' class='form-control' placeholder='Select datepicker' data-rule-required='true' data-format='MM-DD-YYYY' type='text' />
   <span class='input-group-addon'>
       <span class='icon-calendar' data-time-icon='icon-time' data-date-icon='icon-calendar'></span>
   </span>
</div>

Date formate also works in capitals like this data-format='MM-DD-YYYY'

it might be helpful for someone it gave me really hard time :)

Steps to send a https request to a rest service in Node js

Note if you are using https.request do not directly use the body from res.on('data',... This will fail if you have a large data coming in chunks. So you need to concatenate all the data and then process the response in res.on('end'. Example -

  var options = {
    hostname: "www.google.com",
    port: 443,
    path: "/upload",
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Content-Length': Buffer.byteLength(post_data)
    }
  };

  //change to http for local testing
  var req = https.request(options, function (res) {
    res.setEncoding('utf8');

    var body = '';

    res.on('data', function (chunk) {
      body = body + chunk;
    });

    res.on('end',function(){
      console.log("Body :" + body);
      if (res.statusCode != 200) {
        callback("Api call failed with response code " + res.statusCode);
      } else {
        callback(null);
      }
    });

  });

  req.on('error', function (e) {
    console.log("Error : " + e.message);
    callback(e);
  });

  // write data to request body
  req.write(post_data);
  req.end();

How to install MySQLdb package? (ImportError: No module named setuptools)

This was sort of tricky for me too, I did the following which worked pretty well.

  • Download the appropriate Python .egg for setuptools (ie, for Python 2.6, you can get it here. Grab the correct one from the PyPI site here.)
  • chmod the egg to be executable: chmod a+x [egg] (ie, for Python 2.6, chmod a+x setuptools-0.6c9-py2.6.egg)
  • Run ./[egg] (ie, for Python 2.6, ./setuptools-0.6c9-py2.6.egg)

Not sure if you'll need to use sudo if you're just installing it for you current user. You'd definitely need it to install it for all users.

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")

Django - Static file not found

If your static URL is correct but still:

Not found: /static/css/main.css

Perhaps your WSGI problem.

? Config WSGI serves both development env and production env

==========================project/project/wsgi.py==========================

import os
from django.conf import settings
from django.contrib.staticfiles.handlers import StaticFilesHandler
from django.core.wsgi import get_wsgi_application

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'project.settings')
if settings.DEBUG:
    application = StaticFilesHandler(get_wsgi_application())
else:
    application = get_wsgi_application()

HTML iframe - disable scroll

It seems to work using

html, body { overflow: hidden; }

inside the IFrame

edit: Of course this is only working, if you have access to the Iframe's content (which I have in my case)

Angular2 change detection: ngOnChanges not firing for nested object

ok so my solution for this was:

this.arrayWeNeed.DoWhatWeNeedWithThisArray();
const tempArray = [...arrayWeNeed];
this.arrayWeNeed = [];
this.arrayWeNeed = tempArray;

And this trigger me ngOnChanges

api-ms-win-crt-runtime-l1-1-0.dll is missing when opening Microsoft Office file

  1. Delete all temp files
    • search %TEMP%
    • delete all
  2. Perform a clean boot. see How to perform a clean boot in Windows
  3. Install vc_redist.x64 see Download Visual C++ Redistributable for Visual Studio 2015
  4. Restart without clean boot

Append values to a set in Python

keep.update((0,1,2,3,4,5,6,7,8,9,10))

Or

keep.update(np.arange(11))

How to Delete node_modules - Deep Nested Folder in Windows

You can use Git Bash to remove the folder:

example: c:\users\olefrank\projects\mynodeproject

rm -rf /c/users/olefrank/projects/mynodeproject

Is it acceptable and safe to run pip install under sudo?

Is it acceptable & safe to run pip install under sudo?

It's not safe and it's being frowned upon – see What are the risks of running 'sudo pip'? To install Python package in your home directory you don't need root privileges. See description of --user option to pip.

How can I get argv[] as int?

You can use the function int atoi (const char * str);.
You need to include #include <stdlib.h> and use the function in this way:
int x = atoi(argv[1]);
Here more information if needed: atoi - C++ Reference

Unable to get spring boot to automatically create database schema

There are several possible causes:

  1. Your entity classes are in the same or in a sub-package relative one where you have you class with @EnableAutoConfiguration. If not then your spring app does not see them and hence will not create anything in db
  2. Check your config, it seems that you are using some hibernate specific options, try to replace them with:

    spring.jpa.database-platform=org.hibernate.dialect.MySQL5InnoDBDialect
    spring.jpa.hibernate.ddl-auto=update
    spring.datasource.driverClassName=com.mysql.jdbc.Driver
    spring.datasource.url=jdbc:mysql://localhost:3306/test
    spring.datasource.username=test
    spring.datasource.password=
    
  3. Your application.properties must be in src/main/resources folder.

If you did not specify dialect correctly it might try to default to bundled together with boot in-memory database and (as it was with me) I could see that it tries to connect to local HSQL (see console output) instance and fail at updating the schema.

What size should apple-touch-icon.png be for iPad and iPhone?

I have been developing and designing iOS apps for a while and This is the best iOS design cheat sheet out there!

have fun :)!

this image is from that article :)

Update: For iOS 8+, and the new devices (iPhone 6, 6 Plus, iPad Air) see this updated link.

Meta update: Iphone 6s/6s Plus have the same resolutions as iPhone 6/6 Plus respectively

This is an image from the new version of the article:

iOS 8 and mid 2014 devices info

JavaScript - populate drop down list with array

I had the same requirement, I used "Alex Turpin" solution with small corrections as mentioned below.

var select = document.getElementById("selectNumber"); 
var options = ["1", "2", "3", "4", "5"]; 

for(var i = 0; i < options.length; i++) {
    var opt = options[i];

    var el = document.createElement("option");
    el.text = opt;
    el.value = opt;

    select.add(el);
}?

Corrections because with the appendChild() function is loads when the DOM prepares. So It's not working in old(8 or lesser) IE versions. So with the corrections it's working fine.

Thanks Alex for your solution.

Some notes on differences b/w add() and appendChild()

Remove title in Toolbar in appcompat-v7

Try this...

 @Override
 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_landing_page); 

    .....

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar_landing_page);
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayShowTitleEnabled(false);

    .....

 }

SQL How to remove duplicates within select query?

You have to convert the "DateTime" to a "Date". Then you can easier select just one for the given date no matter the time for that date.

Any way to select without causing locking in MySQL?

Found an article titled "MYSQL WITH NOLOCK"

https://web.archive.org/web/20100814144042/http://sqldba.org/articles/22-mysql-with-nolock.aspx

in MS SQL Server you would do the following:

SELECT * FROM TABLE_NAME WITH (nolock)

and the MYSQL equivalent is

SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED ;
SELECT * FROM TABLE_NAME ;
SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ ;

EDIT

Michael Mior suggested the following (from the comments)

SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED ;
SELECT * FROM TABLE_NAME ;
COMMIT ;

Input length must be multiple of 16 when decrypting with padded cipher

I know this message is old and was a long time ago - but i also had problem with with the exact same error:

the problem I had was relates to the fact the encrypted text was converted to String and to byte[] when trying to DECRYPT it.

    private Key getAesKey() throws Exception {
    return new SecretKeySpec(Arrays.copyOf(key.getBytes("UTF-8"), 16), "AES");
}

private Cipher getMutual() throws Exception {
    Cipher cipher = Cipher.getInstance("AES");
    return cipher;// cipher.doFinal(pass.getBytes());
}

public byte[] getEncryptedPass(String pass) throws Exception {
    Cipher cipher = getMutual();
    cipher.init(Cipher.ENCRYPT_MODE, getAesKey());
    byte[] encrypted = cipher.doFinal(pass.getBytes("UTF-8"));
    return encrypted;

}

public String getDecryptedPass(byte[] encrypted) throws Exception {
    Cipher cipher = getMutual();
    cipher.init(Cipher.DECRYPT_MODE, getAesKey());
    String realPass = new String(cipher.doFinal(encrypted));
    return realPass;
}

Oracle: SQL query that returns rows with only numeric values

You can use following command -

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

This will return NULL if your string1 is Numeric

your query would be -

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

Disable F5 and browser refresh using JavaScript

Use this for modern browsers:

function my_onkeydown_handler( event ) {
    switch (event.keyCode) {
        case 116 : // 'F5'
            event.preventDefault();
            event.keyCode = 0;
            window.status = "F5 disabled";
            break;
    }
}
document.addEventListener("keydown", my_onkeydown_handler);

JAVA - using FOR, WHILE and DO WHILE loops to sum 1 through 100

Your for loop looks good.

A possible while loop to accomplish the same thing:

int sum = 0;
int i = 1;
while (i <= 100) {
    sum += i;
    i++;
}
System.out.println("The sum is " + sum);

A possible do while loop to accomplish the same thing:

int sum = 0;
int i = 1;
do {
    sum += i;
    i++;
} while (i <= 100);
System.out.println("The sum is " + sum);

The difference between the while and the do while is that, with the do while, at least one iteration is sure to occur.