Programs & Examples On #Nsdialogs

nsDialogs is a plugin plus a set of macros that allow the creation of custom pages in an NSIS installer on top of the built-in pages, with any type of controls in any order and arrangement. nsDialogs was introduced in NSIS 2.29 as a replacement for InstallOptions.

Bootstrap center heading

Bootstrap comes with many pre-build classes and one of them is class="text-left". Please call this class whenever needed. :-)

Converting a generic list to a CSV string

It's amazing what the Framework already does for us.

List<int> myValues;
string csv = String.Join(",", myValues.Select(x => x.ToString()).ToArray());

For the general case:

IEnumerable<T> myList;
string csv = String.Join(",", myList.Select(x => x.ToString()).ToArray());

As you can see, it's effectively no different. Beware that you might need to actually wrap x.ToString() in quotes (i.e., "\"" + x.ToString() + "\"") in case x.ToString() contains commas.

For an interesting read on a slight variant of this: see Comma Quibbling on Eric Lippert's blog.

Note: This was written before .NET 4.0 was officially released. Now we can just say

IEnumerable<T> sequence;
string csv = String.Join(",", sequence);

using the overload String.Join<T>(string, IEnumerable<T>). This method will automatically project each element x to x.ToString().

Permission denied: /var/www/abc/.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable?

I had the same issue when I changed the home directory of one use. In my case it was because of selinux. I used the below to fix the issue:

selinuxenabled 0
setenforce 0

Is a Java hashmap search really O(1)?

It is O(1) only if your hashing function is very good. The Java hash table implementation does not protect against bad hash functions.

Whether you need to grow the table when you add items or not is not relevant to the question because it is about lookup time.

How to pass a variable from Activity to Fragment, and pass it back?

Sending data from Activity into Fragments linked by XML

If you create a fragment in Android Studio using one of the templates e.g. File > New > Fragment > Fragment (List), then the fragment is linked via XML. The newInstance method is created in the fragment but is never called so can't be used to pass arguments.

Instead in the Activity override the method onAttachFragment

@Override
public void onAttachFragment(Fragment fragment) {
    if (fragment instanceof DetailsFragment) {
        Bundle args = new Bundle();
        args.putInt("index", index);
        f.setArguments(args);        
     }
}

Then read the arguments in the fragment onCreate method as per the other answers

Xlib: extension "RANDR" missing on display ":21". - Trying to run headless Google Chrome

jeues answer helped me nothing :-( after hours I finally found the solution for my system and I think this will help other people too. I had to set the LD_LIBRARY_PATH like this:

   export LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu/

after that everything worked very well, even without any "-extension RANDR" switch.

How can I create an executable JAR with dependencies using Maven?

Taking Unanswered's answer and reformatting it, we have:

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <configuration>
                <archive>
                    <manifest>
                        <addClasspath>true</addClasspath>
                        <mainClass>fully.qualified.MainClass</mainClass>
                    </manifest>
                </archive>
            </configuration>
        </plugin>
        <plugin>
            <artifactId>maven-assembly-plugin</artifactId>
            <configuration>
                <descriptorRefs>
                    <descriptorRef>jar-with-dependencies</descriptorRef>
                </descriptorRefs>
            </configuration>
        </plugin>
    </plugins>
</build>

Next, I would recommend making this a natural part of your build, rather than something to call explicitly. To make this a integral part of your build, add this plugin to your pom.xml and bind it to the package lifecycle event. However, a gotcha is that you need to call the assembly:single goal if putting this in your pom.xml, while you would call 'assembly:assembly' if executing it manually from the command line.

<project>
  [...]
  <build>
      <plugins>
          <plugin>
              <artifactId>maven-assembly-plugin</artifactId>
              <configuration>
                  <archive>
                      <manifest>
                          <addClasspath>true</addClasspath>
                          <mainClass>fully.qualified.MainClass</mainClass>
                      </manifest>
                  </archive>
                  <descriptorRefs>
                      <descriptorRef>jar-with-dependencies</descriptorRef>
                  </descriptorRefs>
              </configuration>
              <executions>
                  <execution>
                      <id>make-my-jar-with-dependencies</id>
                      <phase>package</phase>
                      <goals>
                          <goal>single</goal>
                      </goals>
                  </execution>
              </executions>
          </plugin>
      [...]
      </plugins>
    [...]
  </build>
</project>

how to append a css class to an element by javascript?

var element = document.getElementById(element_id);
element.className += " " + newClassName;

Voilà. This will work on pretty much every browser ever. The leading space is important, because the className property treats the css classes like a single string, which ought to match the class attribute on HTML elements (where multiple classes must be separated by spaces).

Incidentally, you're going to be better off using a Javascript library like prototype or jQuery, which have methods to do this, as well as functions that can first check if an element already has a class assigned.

In prototype, for instance:

// Prototype automatically checks that the element doesn't already have the class
$(element_id).addClassName(newClassName);

See how much nicer that is?!

Hibernate-sequence doesn't exist

You can also put :

@GeneratedValue(strategy = GenerationType.IDENTITY)

And let the DateBase manage the incrementation of the primary key:

AUTO_INCREMENT PRIMARY KEY

The above answer helped me.

SQL Server dynamic PIVOT query?

Updated version for SQL Server 2017 using STRING_AGG function to construct the pivot column list:

create table temp
(
    date datetime,
    category varchar(3),
    amount money
);

insert into temp values ('20120101', 'ABC', 1000.00);
insert into temp values ('20120201', 'DEF', 500.00);
insert into temp values ('20120201', 'GHI', 800.00);
insert into temp values ('20120210', 'DEF', 700.00);
insert into temp values ('20120301', 'ABC', 1100.00);


DECLARE @cols AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX);

SET @cols = (SELECT STRING_AGG(category,',') FROM (SELECT DISTINCT category FROM temp WHERE category IS NOT NULL)t);

set @query = 'SELECT date, ' + @cols + ' from 
            (
                select date
                    , amount
                    , category
                from temp
           ) x
            pivot 
            (
                 max(amount)
                for category in (' + @cols + ')
            ) p ';

execute(@query);

drop table temp;

Changing java platform on which netbeans runs

open etc folder in netbeans folder then edit the netbeans.conf with notepad and you will find a line like this :

Default location of JDK, can be overridden by using --jdkhome :
netbeans_jdkhome="G:\Program Files\Java\jdk1.6.0_13"

here you can set your jdk version.

I can't find my git.exe file in my Github folder

The path for the latest version of Git is changed, In my laptop, I found it in

C:\Users\Anum Sheraz\AppData\Local\Programs\Git\bin\git.exe

This resolved my issue of path. Hope that helps to someone :)

How to increase font size in the Xcode editor?

When changing fonts in XCode from [Preferences] (after duplicating a template that matches colours close to what you want), you can select multiple entries and change the fonts all at once. Use [shift] to select a range or [cmd] to select multiple individual entries (e.g. you might select both 'comments' and 'strings' and change only their fonts).

Steve

Proper way to use AJAX Post in jquery to pass model from strongly typed MVC3 view

what you have is fine - however to save some typing, you can simply use for your data


data: $('#formId').serialize()

see http://www.ryancoughlin.com/2009/05/04/how-to-use-jquery-to-serialize-ajax-forms/ for details, the syntax is pretty basic.

Installing a dependency with Bower from URL and specify version

Just specifying the uri endpoint worked for me, bower 1.3.9

  "dependencies": {
    "jquery.cookie": "latest",
    "everestjs": "http://www.everestjs.net/static/st.v2.js"
  }

Running bower install, I received following output:

bower new           version for http://www.everestjs.net/static/st.v2.js#*
bower resolve       http://www.everestjs.net/static/st.v2.js#*
bower download      http://www.everestjs.net/static/st.v2.js

You could also try updating bower

  • npm update -g bower

According to documentation: the following types of urls are supported:

http://example.com/script.js
http://example.com/style.css
http://example.com/package.zip (contents will be extracted)
http://example.com/package.tar (contents will be extracted)

One line if/else condition in linux shell scripting

It's not a direct answer to the question but you could just use the OR-operator

( grep "#SystemMaxUse=" journald.conf > /dev/null && sed -i 's/\#SystemMaxUse=/SystemMaxUse=50M/g' journald.conf ) || echo "This file has been edited. You'll need to do it manually."

Using ExcelDataReader to read Excel data starting from a particular cell

You could use the .NET library to do the same thing which i believe is more straightforward.

string ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0; data source={path of your excel file}; Extended Properties=Excel 12.0;";

        OleDbConnection objConn = null;
        System.Data.DataTable dt = null;
        //Create connection object by using the preceding connection string.
        objConn = new OleDbConnection(connString);
        objConn.Open();
        //Get the data table containg the schema guid.
        dt = objConn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
        string sql = string.Format("select * from [{0}$]", sheetName);
        var adapter = new System.Data.OleDb.OleDbDataAdapter(sql, ConnectionString);
        var ds = new System.Data.DataSet();
        string tableName = sheetName;
        adapter.Fill(ds, tableName);
        System.Data.DataTable data = ds.Tables[tableName];

After you have your data in the datatable you can access them as you would normally do with a DataTable class.

FB OpenGraph og:image not pulling images (possibly https?)

I ran into the same problem and reported it as a bug on the Facebook developer site. It seems pretty clear that og:image URIs using HTTP work just fine and URIs using HTTPS do not. They have now acknowledged that they are "looking into this."

Update: As of 2020, the bug is no longer visible in Facebook's ticket system. They never responded and I don't believe this behavior has changed. However, specifying HTTPS URI in og:image:secure does seem to be working fine.

What is a pre-revprop-change hook in SVN, and how do I create it?

Basically it's a script that is launched before unversioned property is modified on the repository, so that you can manage more precisely what's happening on your repository.

There are templates in the SVN distrib for different hooks, located in the /hooks subdirectory (*.tmpl that you have to edit and rename depending on your OS, to activate).

Add quotation at the start and end of each line in Notepad++

  1. Put your cursor at the begining of line 1.
  2. click Edit>ColumnEditor. Put " in the text and hit enter.
  3. Repeat 2 but put the cursor at the end of line1 and put ", and hit enter.

Test if object implements interface

This should do:

public static boolean implementsInterface(Object object, Class interf){
    return interf.isInstance(object);
}

For example,

 java.io.Serializable.class.isInstance("a test string")

evaluates to true.

CSS to stop text wrapping under image

setting display:flexfor the text worked for me.

Pythonic way to return list of every nth item in a larger list

newlist = oldlist[::10]

This picks out every 10th element of the list.

How to host a Node.Js application in shared hosting

Connect with SSH and follow these instructions to install Node on a shared hosting

In short you first install NVM, then you install the Node version of your choice with NVM.

wget -qO- https://cdn.rawgit.com/creationix/nvm/master/install.sh | bash

Your restart your shell (close and reopen your sessions). Then you

nvm install stable

to install the latest stable version for example. You can install any version of your choice. Check node --version for the node version you are currently using and nvm list to see what you've installed.

In bonus you can switch version very easily (nvm use <version>)

There's no need of PHP or whichever tricky workaround if you have SSH.

The type initializer for 'MyClass' threw an exception

Dictionary keys should be unique !

In my case, I was using a Dictionary, and I found two items in it have accidentally the same key.

Dictionary<string, string> myDictionary = new Dictionary<string, string>() {
            {"KEY1", "V1"},
            {"KEY1", "V2" },
            {"KEY3", "V3"},
        };

How do I sleep for a millisecond in Perl?

From the Perldoc page on sleep:

For delays of finer granularity than one second, the Time::HiRes module (from CPAN, and starting from Perl 5.8 part of the standard distribution) provides usleep().

Actually, it provides usleep() (which sleeps in microseconds) and nanosleep() (which sleeps in nanoseconds). You may want usleep(), which should let you deal with easier numbers. 1 millisecond sleep (using each):

use strict;
use warnings;

use Time::HiRes qw(usleep nanosleep);

# 1 millisecond == 1000 microseconds
usleep(1000);
# 1 microsecond == 1000 nanoseconds
nanosleep(1000000);

If you don't want to (or can't) load a module to do this, you may also be able to use the built-in select() function:

# Sleep for 250 milliseconds
select(undef, undef, undef, 0.25);

Catching "Maximum request length exceeded"

How about catch it at EndRequest event?

protected void Application_EndRequest(object sender, EventArgs e)
    {
        HttpRequest request = HttpContext.Current.Request;
        HttpResponse response = HttpContext.Current.Response;
        if ((request.HttpMethod == "POST") &&
            (response.StatusCode == 404 && response.SubStatusCode == 13))
        {
            // Clear the response header but do not clear errors and
            // transfer back to requesting page to handle error
            response.ClearHeaders();
            HttpContext.Current.Server.Transfer(request.AppRelativeCurrentExecutionFilePath);
        }
    }

Example for boost shared_mutex (multiple reads/one write)?

It looks like you would do something like this:

boost::shared_mutex _access;
void reader()
{
  // get shared access
  boost::shared_lock<boost::shared_mutex> lock(_access);

  // now we have shared access
}

void writer()
{
  // get upgradable access
  boost::upgrade_lock<boost::shared_mutex> lock(_access);

  // get exclusive access
  boost::upgrade_to_unique_lock<boost::shared_mutex> uniqueLock(lock);
  // now we have exclusive access
}

jQuery: go to URL with target="_blank"

The .ready function is used to insert the attribute once the page has finished loading.

$(document).ready(function() {
     $("class name or id a.your class name").attr({"target" : "_blank"})
})

Code formatting shortcuts in Android Studio for Operation Systems

You will have to apply all Eclipse shortcuts with Android Studio before using all those shortcuts.

Procedure:

Steps:

Setting -> KeyMap -> Select Eclipse -> Apply -> OK

Now you can use all Eclipse shortcuts in Android Studio...

Have some snapshots here.

Enter image description here

Enter image description here

Must declare the scalar variable

Here is a simple example :

Create or alter PROCEDURE getPersonCountByLastName (
@lastName varchar(20),
@count int OUTPUT
)
As
Begin
select @count = count(personSid) from Person where lastName like @lastName
End;

Execute below statements in one batch (by selecting all)

1. Declare @count int
2. Exec getPersonCountByLastName kumar, @count output
3. Select @count

When i tried to execute statements 1,2,3 individually, I had the same error. But when executed them all at one time, it worked fine.

The reason is that SQL executes declare, exec statements in different sessions.

Open to further corrections.

What exactly does a jar file contain?

JAR stands for Java ARchive. It's a file format based on the popular ZIP file format and is used for aggregating many files into one. Although JAR can be used as a general archiving tool, the primary motivation for its development was so that Java applets and their requisite components (.class files, images and sounds) can be downloaded to a browser in a single HTTP transaction, rather than opening a new connection for each piece. This greatly improves the speed with which an applet can be loaded onto a web page and begin functioning. The JAR format also supports compression, which reduces the size of the file and improves download time still further. Additionally, individual entries in a JAR file may be digitally signed by the applet author to authenticate their origin.

What are access specifiers? Should I inherit with private, protected or public?

The explanation from Scott Meyers in Effective C++ might help understand when to use them:

Public inheritance should model "is-a relationship," whereas private inheritance should be used for "is-implemented-in-terms-of" - so you don't have to adhere to the interface of the superclass, you're just reusing the implementation.

Command line .cmd/.bat script, how to get directory of running script

Raymond Chen has a few ideas:

https://devblogs.microsoft.com/oldnewthing/20050128-00/?p=36573

Quoted here in full because MSDN archives tend to be somewhat unreliable:

The easy way is to use the %CD% pseudo-variable. It expands to the current working directory.

set OLDDIR=%CD%
.. do stuff ..
chdir /d %OLDDIR% &rem restore current directory

(Of course, directory save/restore could more easily have been done with pushd/popd, but that's not the point here.)

The %CD% trick is handy even from the command line. For example, I often find myself in a directory where there's a file that I want to operate on but... oh, I need to chdir to some other directory in order to perform that operation.

set _=%CD%\curfile.txt
cd ... some other directory ...
somecommand args %_% args

(I like to use %_% as my scratch environment variable.)

Type SET /? to see the other pseudo-variables provided by the command processor.

Also the comments in the article are well worth scanning for example this one (via the WayBack Machine, since comments are gone from older articles):

http://blogs.msdn.com/oldnewthing/archive/2005/01/28/362565.aspx#362741

This covers the use of %~dp0:

If you want to know where the batch file lives: %~dp0

%0 is the name of the batch file. ~dp gives you the drive and path of the specified argument.

WPF Binding StringFormat Short Date String

Be aware of the single quotes for the string format. This doesn't work:

    Content="{Binding PlannedDateTime, StringFormat={}{0:yy.MM.dd HH:mm}}"

while this does:

    Content="{Binding PlannedDateTime, StringFormat='{}{0:yy.MM.dd HH:mm}'}"

Wait on the Database Engine recovery handle failed. Check the SQL server error log for potential causes

In my case, setting SQL Server Database Engine service startup account to NT AUTHORITY\NETWORK SERVICE failed, but setting it to NT Authority\System allowed me to succesfully install my SQL Server 2016 STD instance.

Just check the following snapshot.

enter image description here

For further details, check @Shanky's answer at https://dba.stackexchange.com/a/71798/66179

Remember: you can avoid server rebooting using setup's SkipRules switch:

setup.exe /ACTION=INSTALL /SkipRules=RebootRequiredCheck

setup.exe /ACTION=UNINSTALL /SkipRules=RebootRequiredCheck

Iterating through directories with Python

Another way of returning all files in subdirectories is to use the pathlib module, introduced in Python 3.4, which provides an object oriented approach to handling filesystem paths (Pathlib is also available on Python 2.7 via the pathlib2 module on PyPi):

from pathlib import Path

rootdir = Path('C:/Users/sid/Desktop/test')
# Return a list of regular files only, not directories
file_list = [f for f in rootdir.glob('**/*') if f.is_file()]

# For absolute paths instead of relative the current dir
file_list = [f for f in rootdir.resolve().glob('**/*') if f.is_file()]

Since Python 3.5, the glob module also supports recursive file finding:

import os
from glob import iglob

rootdir_glob = 'C:/Users/sid/Desktop/test/**/*' # Note the added asterisks
# This will return absolute paths
file_list = [f for f in iglob(rootdir_glob, recursive=True) if os.path.isfile(f)]

The file_list from either of the above approaches can be iterated over without the need for a nested loop:

for f in file_list:
    print(f) # Replace with desired operations

how can select from drop down menu and call javascript function

<select name="aa" onchange="report(this.value)"> 
  <option value="">Please select</option>
  <option value="daily">daily</option>
  <option value="monthly">monthly</option>
</select>

using

function report(period) {
  if (period=="") return; // please select - possibly you want something else here

  const report = "script/"+((period == "daily")?"d":"m")+"_report.php";
  loadXMLDoc(report,'responseTag');
  document.getElementById('responseTag').style.visibility='visible';
  document.getElementById('list_report').style.visibility='hidden';
  document.getElementById('formTag').style.visibility='hidden'; 
} 

Unobtrusive version:

<select id="aa" name="aa"> 
  <option value="">Please select</option>
  <option value="daily">daily</option>
  <option value="monthly">monthly</option>
</select>

using

window.addEventListener("load",function() {
  document.getElementById("aa").addEventListener("change",function() {
    const period = this.value;
    if (period=="") return; // please select - possibly you want something else here

    const report = "script/"+((period == "daily")?"d":"m")+"_report.php";
    loadXMLDoc(report,'responseTag');
    document.getElementById('responseTag').style.visibility='visible';
    document.getElementById('list_report').style.visibility='hidden';
    document.getElementById('formTag').style.visibility='hidden'; 
  }); 
});

jQuery version - same select with ID

$(function() {
  $("#aa").on("change",function() {
    const period = this.value;
    if (period=="") return; // please select - possibly you want something else here

    var report = "script/"+((period == "daily")?"d":"m")+"_report.php";
    loadXMLDoc(report,'responseTag');
    $('#responseTag').show();
    $('#list_report').hide();
    $('#formTag').hide(); 
  }); 
});

Manually adding a Userscript to Google Chrome

This parameter is is working for me:

--enable-easy-off-store-extension-install

Do the following:

  1. Right click on your "Chrome" icon.
  2. Choose properties
  3. At the end of your target line, place these parameters: --enable-easy-off-store-extension-install
  4. It should look like: chrome.exe --enable-easy-off-store-extension-install
  5. Start Chrome by double-clicking on the icon

How to easily import multiple sql files into a MySQL database?

I know it's been a little over two years... but I was looking for a way to do this, and wasn't overly happy with the solution posted (it works fine, but I wanted a little more information as the import happens). When combining all the SQL files in to one, you don't get any sort of progress updates.

So I kept digging for an answer and thought this might be a good place to post what I found for future people looking for the same answer. Here's a command line in Windows that will import multiple SQL files from a folder. You run this from the command line while in the directory where mysql.exe is located.

for /f %f in ('dir /b <dir>\<mask>') do mysql --user=<user> --password=<password> <dbname> < <dir>\%f

With some assumed values (as an example):

for /f %f in ('dir /b c:\sqlbackup\*.sql') do mysql --user=mylogin --password=mypass mydb < c:\sqlbackup\%f

If you had two sets of SQL backups in the folder, you could change the *.sql to something more specific (like mydb_*.sql).

Detect change to selected date with bootstrap-datepicker

You can use onSelect event

 $("#date-daily").datepicker({
  onSelect: function(dateText) {
   alert($('#dp3').val());
  }
});

It is Called when the datepicker is selected. The function receives the selected date as text and the datepicker instance as parameters. this refers to the associated input field.

SEE HERE

How to capture a backspace on the onkeydown event

Try this:

document.addEventListener("keydown", KeyCheck);  //or however you are calling your method
function KeyCheck(event)
{
   var KeyID = event.keyCode;
   switch(KeyID)
   {
      case 8:
      alert("backspace");
      break; 
      case 46:
      alert("delete");
      break;
      default:
      break;
   }
}

How to terminate a process in vbscript

Dim shll : Set shll = CreateObject("WScript.Shell")
Set Rt = shll.Exec("Notepad") : wscript.sleep 4000 : Rt.Terminate

Run the process with .Exec.

Then wait for 4 seconds.

After that kill this process.

How to redirect stderr to null in cmd.exe

Your DOS command 2> nul

Read page Using command redirection operators. Besides the "2>" construct mentioned by Tanuki Software, it lists some other useful combinations.

How to change the DataTable Column Name?

Try this:

dataTable.Columns["Marks"].ColumnName = "SubjectMarks";

How to output to the console in C++/Windows

First off, what compiler or dev environment are you using? If Visual Studio, you need to make a console application project to get console output.

Second,

std::cout << "Hello World" << std::endl;

should work in any C++ console application.

jQuery validate Uncaught TypeError: Cannot read property 'nodeName' of null

I found this answer when I was getting a similar error for nodeName after upgrading to Bootstrap 4. The issue was that the tabs didn't have the nav and nav-tab classes; adding those to the <ul> element fixed the issue.

Where does System.Diagnostics.Debug.Write output appear?

As others have pointed out, listeners have to be registered in order to read these streams. Also note that Debug.Write will only function if the DEBUG build flag is set, while Trace.Write will only function if the TRACE build flag is set.

Setting the DEBUG and/or TRACE flags is easily done in the project properties in Visual Studio or by supplying the following arguments to csc.exe

/define:DEBUG;TRACE

Getting request URL in a servlet

The getRequestURL() omits the port when it is 80 while the scheme is http, or when it is 443 while the scheme is https.

So, just use getRequestURL() if all you want is obtaining the entire URL. This does however not include the GET query string. You may want to construct it as follows then:

StringBuffer requestURL = request.getRequestURL();
if (request.getQueryString() != null) {
    requestURL.append("?").append(request.getQueryString());
}
String completeURL = requestURL.toString();

iOS 11, 12, and 13 installed certificates not trusted automatically (self signed)

This has happened to me also, after undating to IOS11 on my iPhone. When I try to connect to the corporate network it bring up the corporate cert and says it isn't trusted. I press the 'trust' button and the connection fails and the cert does not appear in the trusted certs list.

Replace a value in a data frame based on a conditional (`if`) statement

stata.replace<-function(data,replacevar,replacevalue,ifs) {
  ifs=parse(text=ifs)
  yy=as.numeric(eval(ifs,data,parent.frame()))
  x=sum(yy)
  data=cbind(data,yy)
  data[yy==1,replacevar]=replacevalue
  message=noquote(paste0(x, " replacement are made"))
  print(message)
  return(data[,1:(ncol(data)-1)])
}

Call this function using below line.

d=stata.replace(d,"under20",1,"age<20")

no default constructor exists for class

You declared the constructor blowfish as this:

Blowfish(BlowfishAlgorithm algorithm);

So this line cannot exist (without further initialization later):

Blowfish _blowfish;

since you passed no parameter. It does not understand how to handle a parameter-less declaration of object "BlowFish" - you need to create another constructor for that.

What's the simplest way to extend a numpy array in 2 dimensions?

You can use:

>>> np.concatenate([array1, array2, ...]) 

e.g.

>>> import numpy as np
>>> a = [[1, 2, 3],[10, 20, 30]]
>>> b = [[100,200,300]]
>>> a = np.array(a) # not necessary, but numpy objects prefered to built-in
>>> b = np.array(b) # "^
>>> a
array([[ 1,  2,  3],
       [10, 20, 30]])
>>> b
array([[100, 200, 300]])
>>> c = np.concatenate([a,b])
>>> c
array([[  1,   2,   3],
       [ 10,  20,  30],
       [100, 200, 300]])
>>> print c
[[  1   2   3]
 [ 10  20  30]
 [100 200 300]]

~-+-~-+-~-+-~

Sometimes, you will come across trouble if a numpy array object is initialized with incomplete values for its shape property. This problem is fixed by assigning to the shape property the tuple: (array_length, element_length).

Note: Here, 'array_length' and 'element_length' are integer parameters, which you substitute values in for. A 'tuple' is just a pair of numbers in parentheses.

e.g.

>>> import numpy as np
>>> a = np.array([[1,2,3],[10,20,30]])
>>> b = np.array([100,200,300]) # initialize b with incorrect dimensions
>>> a.shape
(2, 3)
>>> b.shape
(3,)
>>> c = np.concatenate([a,b])

Traceback (most recent call last):
  File "<pyshell#191>", line 1, in <module>
    c = np.concatenate([a,b])
ValueError: all the input arrays must have same number of dimensions
>>> b.shape = (1,3)
>>> c = np.concatenate([a,b])
>>> c
array([[  1,   2,   3],
       [ 10,  20,  30],
       [100, 200, 300]])

iOS detect if user is on an iPad

In Swift you can use the following equalities to determine the kind of device on Universal apps:

UIDevice.current.userInterfaceIdiom == .phone
// or
UIDevice.current.userInterfaceIdiom == .pad

Usage would then be something like:

if UIDevice.current.userInterfaceIdiom == .pad {
    // Available Idioms - .pad, .phone, .tv, .carPlay, .unspecified
    // Implement your logic here
}

jQuery get an element by its data-id

This worked for me, in my case I had a button with a data-id attribute:

$("a").data("item-id");

Fiddle

Finding Variable Type in JavaScript

I find it frustrating that typeof is so limited. Here’s an improved version:

var realtypeof = function (obj) {
    switch (typeof(obj)) {
        // object prototypes
        case 'object':
            if (obj instanceof Array)
                return '[object Array]';
            if (obj instanceof Date)
                return '[object Date]';
            if (obj instanceof RegExp)
                return '[object regexp]';
            if (obj instanceof String)
                return '[object String]';
            if (obj instanceof Number)
                return '[object Number]';

            return 'object';
        // object literals
        default:
            return typeof(obj);
    }   
};

sample test:

realtypeof( '' ) // "string"
realtypeof( new String('') ) // "[object String]"
Object.prototype.toString.call("foo bar") //"[object String]" 

Multiple selector chaining in jQuery?

If we want to apply the same functionality and features to more than one selectors then we use multiple selector options. I think we can say this feature is used like reusability. write a jquery function and just add multiple selectors in which we want the same features.

Kindly take a look in below example:

_x000D_
_x000D_
$( "div, span, .paragraph, #paraId" ).css( {"font-family": "tahoma", "background": "red"} );
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<div>Div element</div>_x000D_
<p class="paragraph">Paragraph with class selector</p>_x000D_
<p id="paraId">Paragraph with id selector</p>_x000D_
<span>Span element</span>
_x000D_
_x000D_
_x000D_

I hope it will help you. Namaste

How to iterate over arguments in a Bash script

Note that Robert's answer is correct, and it works in sh as well. You can (portably) simplify it even further:

for i in "$@"

is equivalent to:

for i

I.e., you don't need anything!

Testing ($ is command prompt):

$ set a b "spaces here" d
$ for i; do echo "$i"; done
a
b
spaces here
d
$ for i in "$@"; do echo "$i"; done
a
b
spaces here
d

I first read about this in Unix Programming Environment by Kernighan and Pike.

In bash, help for documents this:

for NAME [in WORDS ... ;] do COMMANDS; done

If 'in WORDS ...;' is not present, then 'in "$@"' is assumed.

Protractor : How to wait for page complete after click a button?

In this case, you can used:

Page Object:

    waitForURLContain(urlExpected: string, timeout: number) {
        try {
            const condition = browser.ExpectedConditions;
            browser.wait(condition.urlContains(urlExpected), timeout);
        } catch (e) {
            console.error('URL not contain text.', e);
        };
    }

Page Test:

page.waitForURLContain('abc#/efg', 30000);

mat-form-field must contain a MatFormFieldControl

import { MatFormFieldModule } from '@angular/material/form-field';
import { MatInputModule } from '@angular/material/input';

don't forget to add at first of <tabe></table>

 <mat-form-field>
        <mat-label>Filter</mat-label>
        <input matInput (keyup)="applyFilter($event)" placeholder="Ex. Helium" #input>
      </mat-form-field>

don't forget to add at last of <tabe></table>

<tr class="mat-row" *matNoDataRow>
<td class="mat-cell" colspan="4">
   No data matching the filter "{{input.value}}"
</td>
</tr>

assign value using linq

Be aware that it only updates the first company it found with company id 1. For multiple

 (from c in listOfCompany where c.id == 1 select c).First().Name = "Whatever Name";

For Multiple updates

 from c in listOfCompany where c.id == 1 select c => {c.Name = "Whatever Name";  return c;}

port 8080 is already in use and no process using 8080 has been listed

PID is the process ID - not the port number. You need to look for an entry with ":8080" at the end of the address/port part (the second column). Then you can look at the PID and use Task Manager to work out which process is involved... or run netstat -abn which will show the process names (but must be run under an administrator account).

Having said that, I would expect the find "8080" to find it...

Another thing to do is just visit http://localhost:8080 - on that port, chances are it's a web server of some description.

Programmatically change the src of an img tag

Maybe because you have a tag like a parent of the tag. That why you have to click two time the images.

For me the solution is this: http://www.w3schools.com/js/tryit.asp?filename=tryjs_intro_lightbulb

How to add text to a WPF Label in code?

I believe you want to set the Content property. This has more information on what is available to a label.

Can I serve multiple clients using just Flask app.run() as standalone?

flask.Flask.run accepts additional keyword arguments (**options) that it forwards to werkzeug.serving.run_simple - two of those arguments are threaded (a boolean) and processes (which you can set to a number greater than one to have werkzeug spawn more than one process to handle requests).

threaded defaults to True as of Flask 1.0, so for the latest versions of Flask, the default development server will be able to serve multiple clients simultaneously by default. For older versions of Flask, you can explicitly pass threaded=True to enable this behaviour.

For example, you can do

if __name__ == '__main__':
    app.run(threaded=True)

to handle multiple clients using threads in a way compatible with old Flask versions, or

if __name__ == '__main__':
    app.run(threaded=False, processes=3)

to tell Werkzeug to spawn three processes to handle incoming requests, or just

if __name__ == '__main__':
    app.run()

to handle multiple clients using threads if you know that you will be using Flask 1.0 or later.

That being said, Werkzeug's serving.run_simple wraps the standard library's wsgiref package - and that package contains a reference implementation of WSGI, not a production-ready web server. If you are going to use Flask in production (assuming that "production" is not a low-traffic internal application with no more than 10 concurrent users) make sure to stand it up behind a real web server (see the section of Flask's docs entitled Deployment Options for some suggested methods).

How do I get a TextBox to only accept numeric input in WPF?

The following code creates a control which you will be able to use like a normal TextBox however it will only take a positive double as an input:

In the XAML you'll be able to use this control like so:

<local:UnsignedDoubleBox/>

In the C# code add the following inside the current namespace:

public class UnsignedDoubleBox : TextBox
    {
        public UnsignedDoubleBox()
        {
            this.PreviewTextInput += defaultPreviewTextInput;
            DataObject.AddPastingHandler(this, defaultTextBoxPasting);
        }

        private bool IsTextAllowed(TextBox textBox, String text)
        {
            //source: https://stackoverflow.com/questions/23397195/in-wpf-does-previewtextinput-always-give-a-single-character-only#comment89374810_23406386
            String newText = textBox.Text.Insert(textBox.CaretIndex, text);
            double res;
            return double.TryParse(newText, out res) && res >= 0;
        }
        //source: https://stackoverflow.com/a/1268648/13093413
        private void defaultTextBoxPasting(object sender, DataObjectPastingEventArgs e)
        {
            if (e.DataObject.GetDataPresent(typeof(String)))
            {
                String text = (String)e.DataObject.GetData(typeof(String));

                if (!IsTextAllowed((TextBox)sender, text))
                {
                    e.CancelCommand();
                }
            }
            else
            {
                e.CancelCommand();
            }
        }

        private void defaultPreviewTextInput(object sender, TextCompositionEventArgs e)
        {

            if (IsTextAllowed((TextBox)sender, e.Text))
            {
                e.Handled = false;
            }
            else
            {
                e.Handled = true;
            }
        }

    }

How do I get an object's unqualified (short) class name?

Based on @MaBi 's answer, I made this:

trait ClassShortNameTrait
{
    public static function getClassShortName()
    {
        if ($pos = strrchr(static::class, '\\')) {
            return substr($pos, 1);
        } else {
            return static::class;
        }
    }
}

Which you may use like that:

namespace Foo\Bar\Baz;

class A
{
    use ClassShortNameTrait;
}

A::class returns Foo\Bar\Baz\A, but A::getClassShortName() returns A.

Works for PHP >= 5.5.

How to check if a table contains an element in Lua?

I can't think of another way to compare values, but if you use the element of the set as the key, you can set the value to anything other than nil. Then you get fast lookups without having to search the entire table.

SQLSTATE[HY000] [1045] Access denied for user 'root'@'localhost' (using password: YES) symfony2

database_password: password would between quotes: " or '.

like so:

database_password: "password"

No Title Bar Android Theme

In your styles.xml, modify style "AppTheme" like

    <!-- Application theme. -->
    <style name="AppTheme" parent="AppBaseTheme">
        <item name="android:windowActionBar">false</item>
        <item name="android:windowNoTitle">true</item> 
    </style>

How to read from stdin line by line in Node

// Work on POSIX and Windows
var fs = require("fs");
var stdinBuffer = fs.readFileSync(0); // STDIN_FILENO = 0
console.log(stdinBuffer.toString());

Pandas Merge - How to avoid duplicating columns

This is a bit of going around the problem, but I have written a function that basically deals with the extra columns:

def merge_fix_cols(df_company,df_product,uniqueID):
    
    df_merged = pd.merge(df_company,
                         df_product,
                         how='left',left_on=uniqueID,right_on=uniqueID)    
    for col in df_merged:
        if col.endswith('_x'):
            df_merged.rename(columns = lambda col:col.rstrip('_x'),inplace=True)
        elif col.endswith('_y'):
            to_drop = [col for col in df_merged if col.endswith('_y')]
            df_merged.drop(to_drop,axis=1,inplace=True)
        else:
            pass
    return df_merged

Seems to work well with my merges!

Excel VBA - read cell value from code

I think you need this ..

Dim n as Integer   

For n = 5 to 17
  msgbox cells(n,3) '--> sched waste
  msgbox cells(n,4) '--> type of treatm
  msgbox format(cells(n,5),"dd/MM/yyyy") '--> Lic exp
  msgbox cells(n,6) '--> email col
Next

Get path to execution directory of Windows Forms application

Both of the examples are in VB.NET.

Debug path:

TextBox1.Text = My.Application.Info.DirectoryPath

EXE path:

TextBox2.Text = IO.Path.GetFullPath(Application.ExecutablePath)

Angular 4: How to include Bootstrap?

Tested In Angular 7.0.0

Step 1 - Install the required dependencies

npm install bootstrap (if you want specific version please specify the version no.)

npm install popper.js (if you want specific version please specify the version no.)

npm install jquery

Versions I have tried:

"bootstrap": "^4.1.3",
"popper.js": "^1.14.5",
"jquery": "^3.3.1",

Step 2 : Specify the libraries in below orderin angular.json. In latest angular , the config file name is angular.json not angular-cli.json

"architect": {
        "build": {
          "builder": "@angular-devkit/build-angular:browser",
          "options": {
            "outputPath": "dist/client",
            "index": "src/index.html",
            "main": "src/main.ts",
            "polyfills": "src/polyfills.ts",
            "tsConfig": "src/tsconfig.app.json",
            "assets": [
              "src/favicon.ico",
              "src/assets"
            ],
            "styles": [
             "node_modules/bootstrap/dist/css/bootstrap.css",
              "src/styles.scss"
            ],
            "scripts": [
              "node_modules/jquery/dist/jquery.min.js",
              "node_modules/popper.js/dist/umd/popper.min.js",
              "node_modules/bootstrap/dist/js/bootstrap.min.js"
            ]
          },

Convert String to int array in java

If you prefer an Integer[] instead array of an int[] array:

Integer[]

String str = "[1,2]";
String plainStr = str.substring(1, str.length()-1); // clear braces []
String[] parts = plainStr.split(","); 
Integer[] result = Stream.of(parts).mapToInt(Integer::parseInt).boxed().toArray(Integer[]::new);

int[]

String str = "[1,2]";
String plainStr = str.substring(1, str.length()-1); // clear braces []
String[] parts = plainStr.split(","); 
int[] result = Stream.of(parts).mapToInt(Integer::parseInt).toArray()

This works for Java 8 and higher.

How to get today's Date?

Is there are more correct way?

Yes, there is.

LocalDate.now( 
    ZoneId.of( "America/Montreal" ) 
).atStartOfDay(
    ZoneId.of( "America/Montreal" )
)

java.time

Java 8 and later now has the new java.time framework built-in. See Tutorial. Inspired by Joda-Time, defined by JSR 310, and extended by the ThreeTen-Extra project.

Examples

Some examples follow, using java.time. Note how they specify a time zone. If omitted, your JVM’s current default time zone. That default can vary, even changing at any moment during runtime, so I suggest you specify a time zone explicitly rather than rely implicitly on the default.

Here is an example of date-only, without time-of-day nor time zone.

ZoneId zonedId = ZoneId.of( "America/Montreal" );
LocalDate today = LocalDate.now( zonedId );
System.out.println( "today : " + today );

today : 2015-10-19

Here is an example of getting current date-time.

ZoneId zonedId = ZoneId.of( "America/Montreal" );
ZonedDateTime zdt = ZonedDateTime.now( zonedId );
System.out.println( "zdt : " + zdt );

When run:

zdt : 2015-10-19T18:07:02.910-04:00[America/Montreal]

First Moment Of The Day

The Question asks for the date-time where the time is set to zero. This assumes the first moment of the day is always the time 00:00:00.0 but that is not always the case. Daylight Saving Time (DST) and perhaps other anomalies mean the day may begin at a different time such as 01:00.0.

Fortunately, java.time has a facility to determine the first moment of a day appropriate to a particular time zone, LocalDate::atStartOfDay. Let's see some code using the LocalDate named today and the ZoneId named zoneId from code above.

ZonedDateTime todayStart = today.atStartOfDay( zoneId );

zdt : 2015-10-19T00:00:00-04:00[America/Montreal]

Interoperability

If you must have a java.util.Date for use with classes not yet updated to work with the java.time types, convert. Call the java.util.Date.from( Instant instant ) method.

java.util.Date date = java.util.Date.from( zdt.toInstant() );

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.

Where to obtain the java.time classes?

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

error: command 'gcc' failed with exit status 1 while installing eventlet

sudo apt install gcc

It works for PyCharm on Ubuntu 20.10.

javascript regular expression to check for IP addresses

A short RegEx: ^(?:(?:^|\.)(?:2(?:5[0-5]|[0-4]\d)|1?\d?\d)){4}$

Example

_x000D_
_x000D_
const isValidIp = value => (/^(?:(?:^|\.)(?:2(?:5[0-5]|[0-4]\d)|1?\d?\d)){4}$/.test(value) ? true : false);_x000D_
_x000D_
_x000D_
// valid_x000D_
console.log("isValidIp('0.0.0.0') ? ", isValidIp('0.0.0.0'));_x000D_
console.log("isValidIp('115.42.150.37') ? ", isValidIp('115.42.150.37'));_x000D_
console.log("isValidIp('192.168.0.1') ? ", isValidIp('192.168.0.1'));_x000D_
console.log("isValidIp('110.234.52.124' ? ", isValidIp('110.234.52.124'));_x000D_
console.log("isValidIp('115.42.150.37') ? ", isValidIp('115.42.150.37'));_x000D_
console.log("isValidIp('115.42.150.38') ? ", isValidIp('115.42.150.38'));_x000D_
console.log("isValidIp('115.42.150.50') ? ", isValidIp('115.42.150.50'));_x000D_
_x000D_
// Invalid_x000D_
console.log("isValidIp('210.110') ? ", isValidIp('210.110'));_x000D_
console.log("isValidIp('255') ? ", isValidIp('255'));_x000D_
console.log("isValidIp('y.y.y.y' ? ", isValidIp('y.y.y.y'));_x000D_
console.log(" isValidIp('255.0.0.y') ? ", isValidIp('255.0.0.y'));_x000D_
console.log("isValidIp('666.10.10.20') ? ", isValidIp('666.10.10.20'));_x000D_
console.log("isValidIp('4444.11.11.11') ? ", isValidIp('4444.11.11.11'));_x000D_
console.log("isValidIp('33.3333.33.3') ? ", isValidIp('33.3333.33.3'));
_x000D_
_x000D_
_x000D_

How to run JUnit test cases from the command line

If your project is Maven-based you can run all test-methods from test-class CustomTest which belongs to module 'my-module' using next command:

mvn clean test -pl :my-module -Dtest=CustomTest

Or run only 1 test-method myMethod from test-class CustomTest using next command:

mvn clean test -pl :my-module -Dtest=CustomTest#myMethod

For this ability you need Maven Surefire Plugin v.2.7.3+ and Junit 4. More details is here: http://maven.apache.org/surefire/maven-surefire-plugin/examples/single-test.html

Android Relative Layout Align Center

Use this in your RelativeLayout

android:gravity="center_vertical"

How to do multiline shell script in Ansible

Ansible uses YAML syntax in its playbooks. YAML has a number of block operators:

  • The > is a folding block operator. That is, it joins multiple lines together by spaces. The following syntax:

    key: >
      This text
      has multiple
      lines
    

    Would assign the value This text has multiple lines\n to key.

  • The | character is a literal block operator. This is probably what you want for multi-line shell scripts. The following syntax:

    key: |
      This text
      has multiple
      lines
    

    Would assign the value This text\nhas multiple\nlines\n to key.

You can use this for multiline shell scripts like this:

- name: iterate user groups
  shell: |
    groupmod -o -g {{ item['guid'] }} {{ item['username'] }} 
    do_some_stuff_here
    and_some_other_stuff
  with_items: "{{ users }}"

There is one caveat: Ansible does some janky manipulation of arguments to the shell command, so while the above will generally work as expected, the following won't:

- shell: |
    cat <<EOF
    This is a test.
    EOF

Ansible will actually render that text with leading spaces, which means the shell will never find the string EOF at the beginning of a line. You can avoid Ansible's unhelpful heuristics by using the cmd parameter like this:

- shell:
    cmd: |
      cat <<EOF
      This is a test.
      EOF

How to fix: Handler "PageHandlerFactory-Integrated" has a bad module "ManagedPipelineHandler" in its module list

  1. run cmd

  2. drag and drop Aspnet_regiis.exe into the command prompt from:

    C:\Windows\Microsoft.NET\Framework64\v2.0.50727\
    
  3. type -i (for example Aspnet_regiis.exe -i)

  4. hit enter

  5. wait until the process completes

Good luck!

Global variable Python classes

What you have is correct, though you will not call it global, it is a class attribute and can be accessed via class e.g Shape.lolwut or via an instance e.g. shape.lolwut but be careful while setting it as it will set an instance level attribute not class attribute

class Shape(object):
    lolwut = 1

shape = Shape()

print Shape.lolwut,  # 1
print shape.lolwut,  # 1

# setting shape.lolwut would not change class attribute lolwut 
# but will create it in the instance
shape.lolwut = 2

print Shape.lolwut,  # 1
print shape.lolwut,  # 2

# to change class attribute access it via class
Shape.lolwut = 3

print Shape.lolwut,  # 3
print shape.lolwut   # 2 

output:

1 1 1 2 3 2

Somebody may expect output to be 1 1 2 2 3 3 but it would be incorrect

How can I get a uitableViewCell by indexPath?

You can use the following code to get last cell.

UITableViewCell *cell = [tableView cellForRowAtIndexPath:lastIndexPath];

Is there a way to compile node.js source files?

Now this may include more than you need (and may not even work for command line applications in a non-graphical environment, I don't know), but there is nw.js. It's Blink (i.e. Chromium/Webkit) + io.js (i.e. Node.js).

You can use node-webkit-builder to build native executable binaries for Linux, OS X and Windows.

If you want a GUI, that's a huge plus. You can build one with web technologies. If you don't, specify "node-main" in the package.json (and probably "window": {"show": false} although maybe it works to just have a node-main and not a main)

I haven't tried to use it in exactly this way, just throwing it out there as a possibility. I can say it's certainly not an ideal solution for non-graphical Node.js applications.

check if variable empty

To check for null values you can use is_null() as is demonstrated below.

if (is_null($value)) {
   $value = "MY TEXT"; //define to suit
}

Use CASE statement to check if column exists in table - SQL Server

SELECT *
FROM ...
WHERE EXISTS(SELECT 1 
        FROM sys.columns c
        WHERE c.[object_id] = OBJECT_ID('dbo.Tags')
            AND c.name = 'ModifiedByUser'
    )

How to convert an integer to a string in any base?

Recursive

I would simplify the most voted answer to:

BS="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
def to_base(n, b): 
    return "0" if not n else to_base(n//b, b).lstrip("0") + BS[n%b]

With the same advice for RuntimeError: maximum recursion depth exceeded in cmp on very large integers and negative numbers. (You could usesys.setrecursionlimit(new_limit))

Iterative

To avoid recursion problems:

BS="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
def to_base(s, b):
    res = ""
    while s:
        res+=BS[s%b]
        s//= b
    return res[::-1] or "0"

What is the difference between NULL, '\0' and 0?

"NUL" is not 0, but refers to the ASCII NUL character. At least, that's how I've seen it used. The null pointer is often defined as 0, but this depends on the environment you are running in, and the specification of whatever operating system or language you are using.

In ANSI C, the null pointer is specified as the integer value 0. So any world where that's not true is not ANSI C compliant.

pod has unbound PersistentVolumeClaims

You have to define a PersistentVolume providing disc space to be consumed by the PersistentVolumeClaim.

When using storageClass Kubernetes is going to enable "Dynamic Volume Provisioning" which is not working with the local file system.


To solve your issue:

  • Provide a PersistentVolume fulfilling the constraints of the claim (a size >= 100Mi)
  • Remove the storageClass-line from the PersistentVolumeClaim
  • Remove the StorageClass from your cluster

How do these pieces play together?

At creation of the deployment state-description it is usually known which kind (amount, speed, ...) of storage that application will need.
To make a deployment versatile you'd like to avoid a hard dependency on storage. Kubernetes' volume-abstraction allows you to provide and consume storage in a standardized way.

The PersistentVolumeClaim is used to provide a storage-constraint alongside the deployment of an application.

The PersistentVolume offers cluster-wide volume-instances ready to be consumed ("bound"). One PersistentVolume will be bound to one claim. But since multiple instances of that claim may be run on multiple nodes, that volume may be accessed by multiple nodes.

A PersistentVolume without StorageClass is considered to be static.

"Dynamic Volume Provisioning" alongside with a StorageClass allows the cluster to provision PersistentVolumes on demand. In order to make that work, the given storage provider must support provisioning - this allows the cluster to request the provisioning of a "new" PersistentVolume when an unsatisfied PersistentVolumeClaim pops up.


Example PersistentVolume

In order to find how to specify things you're best advised to take a look at the API for your Kubernetes version, so the following example is build from the API-Reference of K8S 1.17:

apiVersion: v1
kind: PersistentVolume
metadata:
  name: ckan-pv-home
  labels:
    type: local
spec:
  capacity:
    storage: 100Mi
  hostPath:
    path: "/mnt/data/ckan"

The PersistentVolumeSpec allows us to define multiple attributes. I chose a hostPath volume which maps a local directory as content for the volume. The capacity allows the resource scheduler to recognize this volume as applicable in terms of resource needs.


Additional Resources:

What is the difference between a static and a non-static initialization code block

"final" guarantees that a variable must be initialized before end of object initializer code. Likewise "static final" guarantees that a variable will be initialized by the end of class initialization code. Omitting the "static" from your initialization code turns it into object initialization code; thus your variable no longer satisfies its guarantees.

How to default to other directory instead of home directory

I also just changed the "Start in" setting of the shortcut icon to: %HOMEDRIVE%/xampp/htdocs/

sql server invalid object name - but tables are listed in SSMS tables list

I just had to close SMSS and reopen it. I tried Refresh Local Cache and that didn't work.

Convert Unicode to ASCII without errors in Python

For broken consoles like cmd.exe and HTML output you can always use:

my_unicode_string.encode('ascii','xmlcharrefreplace')

This will preserve all the non-ascii chars while making them printable in pure ASCII and in HTML.

WARNING: If you use this in production code to avoid errors then most likely there is something wrong in your code. The only valid use case for this is printing to a non-unicode console or easy conversion to HTML entities in an HTML context.

And finally, if you are on windows and use cmd.exe then you can type chcp 65001 to enable utf-8 output (works with Lucida Console font). You might need to add myUnicodeString.encode('utf8').

ngOnInit not being called when Injectable class is Instantiated

Adding to answer by @Sasxa,

In Injectables you can use class normally that is putting initial code in constructor instead of using ngOnInit(), it works fine.

Declare a variable in DB2 SQL

I'm coming from a SQL Server background also and spent the past 2 weeks figuring out how to run scripts like this in IBM Data Studio. Hope it helps.

CREATE VARIABLE v_lookupid INTEGER DEFAULT (4815162342); --where 4815162342 is your variable data 
  SELECT * FROM DB1.PERSON WHERE PERSON_ID = v_lookupid;
  SELECT * FROM DB1.PERSON_DATA WHERE PERSON_ID = v_lookupid;
  SELECT * FROM DB1.PERSON_HIST WHERE PERSON_ID = v_lookupid;
DROP VARIABLE v_lookupid; 

How to load data to hive from HDFS without removing the source file?

from your question I assume that you already have your data in hdfs. So you don't need to LOAD DATA, which moves the files to the default hive location /user/hive/warehouse. You can simply define the table using the externalkeyword, which leaves the files in place, but creates the table definition in the hive metastore. See here: Create Table DDL eg.:

create external table table_name (
  id int,
  myfields string
)
location '/my/location/in/hdfs';

Please note that the format you use might differ from the default (as mentioned by JigneshRawal in the comments). You can use your own delimiter, for example when using Sqoop:

row format delimited fields terminated by ','

Jquery show/hide table rows

Change your black and white IDs to classes instead (duplicate IDs are invalid), add 2 buttons with the proper IDs, and do this:

var rows = $('table.someclass tr');

$('#showBlackButton').click(function() {
    var black = rows.filter('.black').show();
    rows.not( black ).hide();
});

$('#showWhiteButton').click(function() {
    var white = rows.filter('.white').show();
    rows.not( white ).hide();
});

$('#showAll').click(function() {
    rows.show();
});

<button id="showBlackButton">show black</button>
<button id="showWhiteButton">show white</button>
<button id="showAll">show all</button>

<table class="someclass" border="0" cellpadding="0" cellspacing="0" summary="bla bla bla">
    <caption>bla bla bla</caption>
    <thead>
          <tr class="black">
            ...
          </tr>
    </thead>
    <tbody>
        <tr class="white">
            ...
        </tr>
        <tr class="black">
           ...
        </tr>
    </tbody>
</table>

It uses the filter()[docs] method to filter the rows with the black or white class (depending on the button).

Then it uses the not()[docs] method to do the opposite filter, excluding the black or white rows that were previously found.


EDIT: You could also pass a selector to .not() instead of the previously found set. It may perform better that way:

rows.not( `.black` ).hide();

// ...

rows.not( `.white` ).hide();

...or better yet, just keep a cached set of both right from the start:

var rows = $('table.someclass tr');
var black = rows.filter('.black');
var white = rows.filter('.white');

$('#showBlackButton').click(function() {
    black.show();
    white.hide();
});

$('#showWhiteButton').click(function() {
    white.show();
    black.hide();
});

Open two instances of a file in a single Visual Studio session

For file types, where the same file can't be opened in a vertical tab group (for example .vb files) you can

  • Open 2 different instances of Visual Studio
  • Open the same file in each instance
  • Resize the IDE windows & place them side by side to achieve your layout.

If you save to disk in one instance though, you'll have to reload the file when you switch to the other. Also if you make edits in both instances, you'll have to resolve on the second save. Visual Studio prompts you in both cases with various options. You'll simplify your life a bit if you edit in only the one instance.

How to sort a file, based on its numerical values for a field?

You must do the following command:

sort -n -k1 filename

That should do it :)

How to semantically add heading to a list

You could also use the <figure> element to link a heading to your list like this:

<figure>
    <figcaption>My favorite fruits</figcaption>    
       <ul>
          <li>Banana</li>
          <li>Orange</li>
          <li>Chocolate</li>
       </ul>
</figure>

Source: https://www.w3.org/TR/2017/WD-html53-20171214/single-page.html#the-li-element (Example 162)

How to get current route in Symfony 2?

From something that is ContainerAware (like a controller):

$request = $this->container->get('request');
$routeName = $request->get('_route');

How to find out which JavaScript events fired?

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

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

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

For example:

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

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

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

    AnonymousAndrew has also pointed out monitorEvents(window); here

    How to set placeholder value using CSS?

    You can do this for webkit:

    #text2::-webkit-input-placeholder::before {
        color:#666;
        content:"Line 1\A Line 2\A Line 3\A";
    }
    

    http://jsfiddle.net/Z3tFG/1/

    Which Eclipse version should I use for an Android app?

    Update July 2017:

    From ADT Plugin page, the question must be unasked:

    The Eclipse ADT plugin is no longer supported, as per this announcement in June 2015.

    The Eclipse ADT plugin has many known bugs and potential security bugs that will not be fixed.

    You should immediately switch to use Android Studio, the official IDE for Android. For help transitioning your projects, read Migrate to Android Studio.

    how to change language for DataTable

    It is indeed

    language: {
     url: '//URL_TO_CDN'
    }
    

    The problem is not all of the DataTables (As of this writing) are valid JSON. The Traditional Chinese file for instance is one of them.

    To get around this I wrote the following code in JavaScript:

      var dataTableLanguages = {
        'es': '//cdn.datatables.net/plug-ins/1.10.21/i18n/Spanish.json',
        'fr': '//cdn.datatables.net/plug-ins/1.10.21/i18n/French.json',
        'ar': '//cdn.datatables.net/plug-ins/1.10.21/i18n/Arabic.json',
        'zh-TW': {
          "processing": "???...",
          "loadingRecords": "???...",
          "lengthMenu": "?? _MENU_ ???",
          "zeroRecords": "???????",
          "info": "??? _START_ ? _END_ ???,? _TOTAL_ ?",
          "infoEmpty": "??? 0 ? 0 ???,? 0 ?",
          "infoFiltered": "(? _MAX_ ??????)",
          "infoPostFix": "",
          "search": "??:",
          "paginate": {
            "first": "???",
            "previous": "???",
            "next": "???",
            "last": "????"
          },
          "aria": {
            "sortAscending": ": ????",
            "sortDescending": ": ????"
          }
        }
      };
      var language = dataTableLanguages[$('html').attr('lang')];
    
      var opts = {...};
      
      if (language) {
        if (typeof language === 'string') {
           opts.language = {
             url: language
           };
        } else {
           opts.language = language;
        }
      }
    

    Now use the opts as option object for data table like

    $('#list-table').DataTable(opts)
    

    How to detect Windows 64-bit platform with .NET?

    I use:

    Dim drivelet As String = Application.StartupPath.ToString
    If Directory.Exists(drivelet(0) & ":\Program Files (x86)") Then
        MsgBox("64bit")
    Else
        MsgBox("32bit")
    End if
    

    This gets the path where your application is launched in case you have it installed in various places on the computer. Also, you could just do the general C:\ path since 99.9% of computers out there have Windows installed in C:\.

    What event handler to use for ComboBox Item Selected (Selected Item not necessarily changed)

    I had the same question and I finally found the answer:

    You need to handle BOTH the SelectionChanged event and the DropDownClosed like this:

    In XAML:

    <ComboBox Name="cmbSelect" SelectionChanged="ComboBox_SelectionChanged" DropDownClosed="ComboBox_DropDownClosed">
        <ComboBoxItem>1</ComboBoxItem>
        <ComboBoxItem>2</ComboBoxItem>
        <ComboBoxItem>3</ComboBoxItem>
    </ComboBox>
    

    In C#:

    private bool handle = true;
    private void ComboBox_DropDownClosed(object sender, EventArgs e) {
      if(handle)Handle();
      handle = true;
    }
    
    private void ComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e) {
      ComboBox cmb = sender as ComboBox;
      handle = !cmb.IsDropDownOpen;
      Handle();
    }
    
    private void Handle() {
      switch (cmbSelect.SelectedItem.ToString().Split(new string[] { ": " }, StringSplitOptions.None).Last())
      { 
          case "1":
              //Handle for the first combobox
              break;
          case "2":
              //Handle for the second combobox
              break;
          case "3":
              //Handle for the third combobox
              break;
      }
    }
    

    Using await outside of an async function

    As of Node.js 14.3.0 the top-level await is supported.

    Required flag: --experimental-top-level-await.

    Further details: https://v8.dev/features/top-level-await

    How to prevent Browser cache for php site

    I had problem with caching my css files. Setting headers in PHP didn't help me (perhaps because the headers would need to be set in the stylesheet file instead of the page linking to it?).

    I found the solution on this page: https://css-tricks.com/can-we-prevent-css-caching/

    The solution:

    Append timestamp as the query part of the URI for the linked file.
    (Can be used for css, js, images etc.)

    For development:

    <link rel="stylesheet" href="style.css?<?php echo date('Y-m-d_H:i:s'); ?>">

    For production (where caching is mostly a good thing):

    <link rel="stylesheet" type="text/css" href="style.css?version=3.2">
    (and rewrite manually when it is required)

    Or combination of these two:

    <?php
        define( "DEBUGGING", true ); // or false in production enviroment
    ?>
    <!-- ... -->
    <link rel="stylesheet" type="text/css" href="style.css?version=3.2<?php echo (DEBUGGING) ? date('_Y-m-d_H:i:s') : ""; ?>">
    

    EDIT:

    Or prettier combination of those two:

    <?php
        // Init
        define( "DEBUGGING", true ); // or false in production enviroment
        // Functions
        function get_cache_prevent_string( $always = false ) {
            return (DEBUGGING || $always) ? date('_Y-m-d_H:i:s') : "";
        }
    ?>
    <!-- ... -->
    <link rel="stylesheet" type="text/css" href="style.css?version=3.2<?php echo get_cache_prevent_string(); ?>">
    

    python: SyntaxError: EOL while scanning string literal

    I had this problem - I eventually worked out that the reason was that I'd included \ characters in the string. If you have any of these, "escape" them with \\ and it should work fine.

    How to get HttpClient to pass credentials along with the request?

    It worked for me after I set up a user with internet access in the Windows service.

    In my code:

    HttpClientHandler handler = new HttpClientHandler();
    handler.Proxy = System.Net.WebRequest.DefaultWebProxy;
    handler.Proxy.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials;
    .....
    HttpClient httpClient = new HttpClient(handler)
    .... 
    

    Redirect parent window from an iframe action

    Try using

    window.parent.window.location.href = 'http://google.com'
    

    mvn command not found in OSX Mavrerick

    I got same problem, I tried all above, noting solved my problem. Luckely, I solved the problem this way:

    echo $SHELL
    

    Output

    /bin/zsh
    OR 
    /bin/bash
    
    If it showing "bash" in output. You have to add env properties in .bashrc file (.bash_profile i did not tried, you can try) or else
    It is showing 'zsh' in output. You have to add env properties in .zshrc file, if not exist already you create one no issue.
    

    Wait 5 seconds before executing next line

    You have to put your code in the callback function you supply to setTimeout:

    function stateChange(newState) {
        setTimeout(function () {
            if (newState == -1) {
                alert('VIDEO HAS STOPPED');
            }
        }, 5000);
    }
    

    Any other code will execute immediately.

    Could pandas use column as index?

    You can change the index as explained already using set_index. You don't need to manually swap rows with columns, there is a transpose (data.T) method in pandas that does it for you:

    > df = pd.DataFrame([['ABBOTSFORD', 427000, 448000],
                        ['ABERFELDIE', 534000, 600000]],
                        columns=['Locality', 2005, 2006])
    
    > newdf = df.set_index('Locality').T
    > newdf
    
    Locality    ABBOTSFORD  ABERFELDIE
    2005        427000      534000
    2006        448000      600000
    

    then you can fetch the dataframe column values and transform them to a list:

    > newdf['ABBOTSFORD'].values.tolist()
    
    [427000, 448000]
    

    How to select distinct rows in a datatable and store into an array

    var distinctRows = (from DataRow dRow in dtInventory.Rows
                                    select dRow["column_name"] ).Distinct();
    
    var distinctRows = (from DataRow dRow in dtInventory.Rows
                                    select dRow["col1"], dRow["col2"].. ).Distinct();
    

    How do I change the string representation of a Python class?

    This is not as easy as it seems, some core library functions don't work when only str is overwritten (checked with Python 2.7), see this thread for examples How to make a class JSON serializable Also, try this

    import json
    
    class A(unicode):
        def __str__(self):
            return 'a'
        def __unicode__(self):
            return u'a'
        def __repr__(self):
            return 'a'
    
    a = A()
    json.dumps(a)
    

    produces

    '""'
    

    and not

    '"a"'
    

    as would be expected.

    EDIT: answering mchicago's comment:

    unicode does not have any attributes -- it is an immutable string, the value of which is hidden and not available from high-level Python code. The json module uses re for generating the string representation which seems to have access to this internal attribute. Here's a simple example to justify this:

    b = A('b') print b

    produces

    'a'

    while

    json.dumps({'b': b})

    produces

    {"b": "b"}

    so you see that the internal representation is used by some native libraries, probably for performance reasons.

    See also this for more details: http://www.laurentluce.com/posts/python-string-objects-implementation/

    How can I select all rows with sqlalchemy?

    I use the following snippet to view all the rows in a table. Use a query to find all the rows. The returned objects are the class instances. They can be used to view/edit the values as required:

    from sqlalchemy.ext.declarative import declarative_base
    from sqlalchemy import create_engine, Sequence
    from sqlalchemy import String, Integer, Float, Boolean, Column
    from sqlalchemy.orm import sessionmaker
    
    Base = declarative_base()
    
    class MyTable(Base):
        __tablename__ = 'MyTable'
        id = Column(Integer, Sequence('user_id_seq'), primary_key=True)
        some_col = Column(String(500))
    
        def __init__(self, some_col):
            self.some_col = some_col
    
    engine = create_engine('sqlite:///sqllight.db', echo=True)
    Session = sessionmaker(bind=engine)
    session = Session()
    
    for class_instance in session.query(MyTable).all():
        print(vars(class_instance))
    
    session.close()
    

    Delete column from SQLite table

    For simplicity, why not create the backup table from the select statement?

    CREATE TABLE t1_backup AS SELECT a, b FROM t1;
    DROP TABLE t1;
    ALTER TABLE t1_backup RENAME TO t1;
    

    Querying a linked sql server

    SELECT * FROM [server].[database].[schema].[table]
    

    This works for me. SSMS intellisense may still underline this as a syntax error, but it should work if your linked server is configured and your query is otherwise correct.

    CSS: transition opacity on mouse-out?

    $(window).scroll(function() {    
        $('.logo_container, .slogan').css({
            "opacity" : ".1",
            "transition" : "opacity .8s ease-in-out"
        });
    });
    

    Check the fiddle: http://jsfiddle.net/2k3hfwo0/2/

    How to redirect output of systemd service to a file

    I think there's a more elegant way to solve the problem: send the stdout/stderr to syslog with an identifier and instruct your syslog manager to split its output by program name.

    Use the following properties in your systemd service unit file:

    StandardOutput=syslog
    StandardError=syslog
    SyslogIdentifier=<your program identifier> # without any quote
    

    Then, assuming your distribution is using rsyslog to manage syslogs, create a file in /etc/rsyslog.d/<new_file>.conf with the following content:

    if $programname == '<your program identifier>' then /path/to/log/file.log
    & stop
    

    Now make the log file writable by syslog:

    # ls -alth /var/log/syslog 
    -rw-r----- 1 syslog adm 439K Mar  5 19:35 /var/log/syslog
    # chown syslog:adm /path/to/log/file.log
    

    Restart rsyslog (sudo systemctl restart rsyslog) and enjoy! Your program stdout/stderr will still be available through journalctl (sudo journalctl -u <your program identifier>) but they will also be available in your file of choice.

    Source via archive.org

    Cannot open database "test" requested by the login. The login failed. Login failed for user 'xyz\ASPNET'

    The best option would be to use Windows integrated authentication as it is more secure than sql authentication. Create a new windows user in sql server with necessary permissions and change IIS user in the application pool security settings.

    How to enable ASP classic in IIS7.5

    Add Authenticated Users

    Make the file accessible to the Authenticated Users group. Right click your virtual directory and give the group read/write access to Authenticated Users.

    I faced issue on windows 10 machine.

    spring data jpa @query and pageable

    With @Query , we can use pagination as well where you need to pass object of Pageable class at end of JPA method

    For example:

    Pageable pageableRequest = new PageRequest(page, size, Sort.Direction.DESC, rollNo);
    

    Where, page = index of page (index start from zero)
    size = No. of records
    Sort.Direction = Sorting as per rollNo
    rollNo = Field in User class

    UserRepository repo
    repo.findByFirstname("John", pageableRequest);
    
    public interface UserRepository extends JpaRepository<User, Long> {
    
      @Query(value = "SELECT * FROM USER WHERE FIRSTNAME = :firstname)
      Page<User> findByLastname(@Param("firstname") String firstname, Pageable pageable);
    }
    

    How to remove text from a string?

    Plain old JavaScript will suffice - jQuery is not necessary for such a simple task:

    var myString = "data-123";
    var myNewString = myString.replace("data-", "");
    

    See: .replace() docs on MDN for additional information and usage.

    How can I introduce multiple conditions in LIKE operator?

    Here is an alternative way:

    select * from tbl where col like 'ABC%'
    union
    select * from tbl where col like 'XYZ%'
    union
    select * from tbl where col like 'PQR%';
    

    Here is the test code to verify:

    create table tbl (col varchar(255));
    insert into tbl (col) values ('ABCDEFG'), ('HIJKLMNO'), ('PQRSTUVW'), ('XYZ');
    select * from tbl where col like 'ABC%'
    union
    select * from tbl where col like 'XYZ%'
    union
    select * from tbl where col like 'PQR%';
    +----------+
    | col      |
    +----------+
    | ABCDEFG  |
    | XYZ      |
    | PQRSTUVW |
    +----------+
    3 rows in set (0.00 sec)
    

    Correct way to detach from a container without stopping it

    You can simply kill docker cli process by sending SEGKILL. If you started the container with

    docker run -it some/container

    You can get it's pid

    ps -aux | grep docker

    user   1234  0.3  0.6 1357948 54684 pts/2   Sl+  15:09   0:00 docker run -it some/container
    

    let's say it's 1234, you can "detach" it with

    kill -9 1234

    It's somewhat of a hack but it works!

    How to populate a sub-document in mongoose after creating it?

    This might have changed since the original answer was written, but it looks like you can now use the Models populate function to do this without having to execute an extra findOne. See: http://mongoosejs.com/docs/api.html#model_Model.populate. You'd want to use this inside the save handler just like the findOne is.

    What does @media screen and (max-width: 1024px) mean in CSS?

    It targets some specified feature to execute some other codes...

    For example:

    @media all and (max-width: 600px) {
      .navigation {
        -webkit-flex-flow: column wrap;
        flex-flow: column wrap;
        padding: 0;
    
      }
    

    the above snippet say if the device that run this program have screen with 600px or less than 600px width, in this case our program must execute this part .

    shift a std_logic_vector of n bit to right or left

    Personally, I think the concatenation is the better solution. The generic implementation would be

    entity shifter is
        generic (
            REGSIZE  : integer := 8);
        port(
            clk      : in  str_logic;
            Data_in  : in  std_logic;
            Data_out : out std_logic(REGSIZE-1 downto 0);
    end shifter ;
    
    architecture bhv of shifter is
        signal shift_reg : std_logic_vector(REGSIZE-1 downto 0) := (others<='0');
    begin
        process (clk) begin
            if rising_edge(clk) then
                shift_reg <= shift_reg(REGSIZE-2 downto 0) & Data_in;
            end if;
        end process;
    end bhv;
    Data_out <= shift_reg;
    

    Both will implement as shift registers. If you find yourself in need of more shift registers than you are willing to spend resources on (EG dividing 1000 numbers by 4) you might consider using a BRAM to store the values and a single shift register to contain "indices" that result in the correct shift of all the numbers.

    Check for internet connection with Swift

    Create a new Swift file within your project, name it Reachability.swift. Cut & paste the following code into it to create your class.

    import Foundation
    import SystemConfiguration
    
    public class Reachability {
    
        class func isConnectedToNetwork() -> Bool {
    
            var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
            zeroAddress.sin_len = UInt8(sizeofValue(zeroAddress))
            zeroAddress.sin_family = sa_family_t(AF_INET)
    
            let defaultRouteReachability = withUnsafePointer(&zeroAddress) {
                SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, UnsafePointer($0))
            }
    
            var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0)
            if SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) == false {
                 return false
            }
    
            let isReachable = flags == .Reachable
            let needsConnection = flags == .ConnectionRequired
    
            return isReachable && !needsConnection
    
        }
    }
    

    You can check internet connection anywhere in your project using this code:

    if Reachability.isConnectedToNetwork() {
        println("Internet connection OK")
    } else {
        println("Internet connection FAILED")
    }
    

    If the user is not connected to the internet, you may want to show them an alert dialog to notify them.

    if Reachability.isConnectedToNetwork() {
        println("Internet connection OK")
    } else {
        println("Internet connection FAILED")
        var alert = UIAlertView(title: "No Internet Connection", message: "Make sure your device is connected to the internet.", delegate: nil, cancelButtonTitle: "OK")
        alert.show()
    }
    

    Explanation:

    We are making a reusable public class and a method which can be used anywhere in the project to check internet connectivity. We require adding Foundation and System Configuration frameworks.

    In the public class Reachability, the method isConnectedToNetwork() -> Bool { } will return a bool value about internet connectivity. We use a if loop to perform required actions on case. I hope this is enough. Cheers!

    How to stop an animation (cancel() does not work)

    You must use .clearAnimation(); method in UI thread:

    runOnUiThread(new Runnable() {
        @Override
        public void run() {
            v.clearAnimation();
        }
    });
    

    Java ArrayList - how can I tell if two lists are equal, order not mattering?

    This is based on @cHao solution. I included several fixes and performance improvements. This runs roughly twice as fast the equals-ordered-copy solution. Works for any collection type. Empty collections and null are regarded as equal. Use to your advantage ;)

    /**
     * Returns if both {@link Collection Collections} contains the same elements, in the same quantities, regardless of order and collection type.
     * <p>
     * Empty collections and {@code null} are regarded as equal.
     */
    public static <T> boolean haveSameElements(Collection<T> col1, Collection<T> col2) {
        if (col1 == col2)
            return true;
    
        // If either list is null, return whether the other is empty
        if (col1 == null)
            return col2.isEmpty();
        if (col2 == null)
            return col1.isEmpty();
    
        // If lengths are not equal, they can't possibly match
        if (col1.size() != col2.size())
            return false;
    
        // Helper class, so we don't have to do a whole lot of autoboxing
        class Count
        {
            // Initialize as 1, as we would increment it anyway
            public int count = 1;
        }
    
        final Map<T, Count> counts = new HashMap<>();
    
        // Count the items in col1
        for (final T item : col1) {
            final Count count = counts.get(item);
            if (count != null)
                count.count++;
            else
                // If the map doesn't contain the item, put a new count
                counts.put(item, new Count());
        }
    
        // Subtract the count of items in col2
        for (final T item : col2) {
            final Count count = counts.get(item);
            // If the map doesn't contain the item, or the count is already reduced to 0, the lists are unequal 
            if (count == null || count.count == 0)
                return false;
            count.count--;
        }
    
        // At this point, both collections are equal.
        // Both have the same length, and for any counter to be unequal to zero, there would have to be an element in col2 which is not in col1, but this is checked in the second loop, as @holger pointed out.
        return true;
    }
    

    How can I create a keystore?

    Signing Your App in Android Studio

    To sign your app in release mode in Android Studio, follow these steps:

    1- On the menu bar, click Build > Generate Signed APK.


    2-On the Generate Signed APK Wizard window, click Create new to create a new keystore. If you already have a keystore, go to step 4.


    3- On the New Key Store window, provide the required information as shown in figure Your key should be valid for at least 25 years, so you can sign app updates with the same key through the lifespan of your app.

    enter image description here

    4- On the Generate Signed APK Wizard window, select a keystore, a private key, and enter the passwords for both. Then click Next.enter image description here

    5- On the next window, select a destination for the signed APK and click Finish. enter image description here

    referance

    http://developer.android.com/tools/publishing/app-signing.html

    Is it possible to declare a public variable in vba and assign a default value?

    Just to offer you a different angle -

    I find it's not a good idea to maintain public variables between function calls. Any variables you need to use should be stored in Subs and Functions and passed as parameters. Once the code is done running, you shouldn't expect the VBA Project to maintain the values of any variables.

    The reason for this is that there is just a huge slew of things that can inadvertently reset the VBA Project while using the workbook. When this happens, any public variables get reset to 0.

    If you need a value to be stored outside of your subs and functions, I highly recommend using a hidden worksheet with named ranges for any information that needs to persist.

    how to remove css property using javascript?

    To change all classes for an element:

    document.getElementById("ElementID").className = "CssClass";
    

    To add an additional class to an element:

    document.getElementById("ElementID").className += " CssClass";
    

    To check if a class is already applied to an element:

    if ( document.getElementById("ElementID").className.match(/(?:^|\s)CssClass(?!\S)/) )
    

    Angular 4 HttpClient Query Parameters

    With Angular 7, I got it working by using the following without using HttpParams.

    import { HttpClient } from '@angular/common/http';
    
    export class ApiClass {
    
      constructor(private httpClient: HttpClient) {
        // use it like this in other services / components etc.
        this.getDataFromServer().
          then(res => {
            console.log('res: ', res);
          });
      }
    
      getDataFromServer() {
        const params = {
          param1: value1,
          param2: value2
        }
        const url = 'https://api.example.com/list'
    
        // { params: params } is the same as { params } 
        // look for es6 object literal to read more
        return this.httpClient.get(url, { params }).toPromise();
      }
    }
    

    Parse error: syntax error, unexpected [

    Are you using php 5.4 on your local? the render line is using the new way of initializing arrays. Try replacing ["title" => "Welcome "] with array("title" => "Welcome ")

    What does --net=host option in Docker command really do?

    1. you can create your own new network like --net="anyname"
    2. this is done to isolate the services from different container.
    3. suppose the same service are running in different containers, but the port mapping remains same, the first container starts well , but the same service from second container will fail. so to avoid this, either change the port mappings or create a network.

    Uncaught TypeError: (intermediate value)(...) is not a function

    I have faced this issue when I created a new ES2015 class where the property name was equal to the method name.

    e.g.:

    class Test{
      constructor () {
        this.test = 'test'
      }
    
      test (test) {
        this.test = test
      }
    }
    
    let t = new Test()
    t.test('new Test')
    

    Please note this implementation was in NodeJS 6.10.

    As a workaround (if you do not want to use the boring 'setTest' method name), you could use a prefix for your 'private' properties (like _test).

    Open your Developer Tools in jsfiddle.

    How to return a 200 HTTP Status Code from ASP.NET MVC 3 controller

    The way to do this in .NET Core is (at the time of writing) as follows:

    public async Task<IActionResult> YourAction(YourModel model)
    {
        if (ModelState.IsValid)
        {
            return StatusCode(200);
        }
    
        return StatusCode(400);
    }
    

    The StatusCode method returns a type of StatusCodeResult which implements IActionResult and can thus be used as a return type of your action.

    As a refactor, you could improve readability by using a cast of the HTTP status codes enum like:

    return StatusCode((int)HttpStatusCode.OK);
    

    Furthermore, you could also use some of the built in result types. For example:

    return Ok(); // returns a 200
    return BadRequest(ModelState); // returns a 400 with the ModelState as JSON
    

    Ref. StatusCodeResult - https://docs.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.mvc.statuscoderesult?view=aspnetcore-2.1

    Hide Twitter Bootstrap nav collapse on click

    try this:

    $('.nav a').on('click', function(){
        $('.btn-navbar').click(); //bootstrap 2.x
        $('.navbar-toggle').click(); //bootstrap 3.x by Richard
        $('.navbar-toggler').click(); //bootstrap 4.x
    });
    

    How to get the <html> tag HTML with JavaScript / jQuery?

    This is how to get the html DOM element purely with JS:

    var htmlElement = document.getElementsByTagName("html")[0];
    

    or

    var htmlElement = document.querySelector("html");
    

    And if you want to use jQuery to get attributes from it...

    $(htmlElement).attr(INSERT-ATTRIBUTE-NAME);
    

    How to create an email form that can send email using html

    Html by itself will not send email. You will need something that connects to a SMTP server to send an email. Hence Outlook pops up with mailto: else your form goes to the server which has a script that sends email.

    Android Facebook integration with invalid key hash

    Here are a lot of right answers. Just one thing:

    Paste the received hash into ApplicationSettingsMain, not via the fast start tutorial.

    How to get all selected values from <select multiple=multiple>?

    Works everywhere without jquery:

    var getSelectValues = function (select) {
        var ret = [];
    
        // fast but not universally supported
        if (select.selectedOptions != undefined) {
            for (var i=0; i < select.selectedOptions.length; i++) {
                ret.push(select.selectedOptions[i].value);
            }
    
        // compatible, but can be painfully slow
        } else {
            for (var i=0; i < select.options.length; i++) {
                if (select.options[i].selected) {
                    ret.push(select.options[i].value);
                }
            }
        }
        return ret;
    };
    

    Chrome javascript debugger breakpoints don't do anything?

    I had an issue where Chrome's breakpoints weren't firing anything. When I tried to use 'debugger' in my code, I could only step through the code in the VM version of my code. My issue was that I was mapping the resources incorrectly. Re-mapping fixed my problem.

    Can I have multiple Xcode versions installed?

    You may want to use the "xcode-select" command in terminal to switch between the different Xcode version in the installed folders.

    TypeError: Cannot read property 'then' of undefined

    TypeError: Cannot read property 'then' of undefined when calling a Django service using AngularJS.

    If you are calling a Python service, the code will look like below:

    this.updateTalentSupplier=function(supplierObj){
      var promise = $http({
        method: 'POST',
          url: bbConfig.BWS+'updateTalentSupplier/',
          data:supplierObj,
          withCredentials: false,
          contentType:'application/json',
          dataType:'json'
        });
        return promise; //Promise is returned 
    }
    

    We are using MongoDB as the database(I know it doesn't matter. But if someone is searching with MongoDB + Python (Django) + AngularJS the result should come.

    Fastest way to check if a value exists in a list

    Or use __contains__:

    sequence.__contains__(value)
    

    Demo:

    >>> l = [1, 2, 3]
    >>> l.__contains__(3)
    True
    >>> 
    

    IntelliJ - show where errors are

    For those who even yet have the problem, try enabling "Build project automatically" in the Java compiler settings and see if that makes a difference as it worked for me.

    Easiest way to develop simple GUI in Python

    Try with Kivy! kivy.org It's quite easy, multi platform and a really good documentation

    Web Service vs WCF Service

    From What's the Difference between WCF and Web Services?

    WCF is a replacement for all earlier web service technologies from Microsoft. It also does a lot more than what is traditionally considered as "web services".

    WCF "web services" are part of a much broader spectrum of remote communication enabled through WCF. You will get a much higher degree of flexibility and portability doing things in WCF than through traditional ASMX because WCF is designed, from the ground up, to summarize all of the different distributed programming infrastructures offered by Microsoft. An endpoint in WCF can be communicated with just as easily over SOAP/XML as it can over TCP/binary and to change this medium is simply a configuration file mod. In theory, this reduces the amount of new code needed when porting or changing business needs, targets, etc.

    ASMX is older than WCF, and anything ASMX can do so can WCF (and more). Basically you can see WCF as trying to logically group together all the different ways of getting two apps to communicate in the world of Microsoft; ASMX was just one of these many ways and so is now grouped under the WCF umbrella of capabilities.

    Web Services can be accessed only over HTTP & it works in stateless environment, where WCF is flexible because its services can be hosted in different types of applications. Common scenarios for hosting WCF services are IIS,WAS, Self-hosting, Managed Windows Service.

    The major difference is that Web Services Use XmlSerializer. But WCF Uses DataContractSerializer which is better in performance as compared to XmlSerializer.

    What's the easiest way to install a missing Perl module?

    On ubuntu most perl modules are already packaged, so installing is much faster than most other systems which have to compile.

    To install Foo::Bar at a commmand prompt for example usually you just do:

    sudo apt-get install libfoo-bar-perl
    

    Sadly not all modules follow that naming convention.

    Background Image for Select (dropdown) does not work in Chrome

    you can use the below css styles for all browsers except Firefox 30

    select {
      background: url(dropdown_arw.png) no-repeat right center;
      appearance: none;
      -moz-appearance: none;
      -webkit-appearance: none;
      width: 90px;
      text-indent: 0.01px;
      text-overflow: "";
    }
    

    demo page - http://kvijayanand.in/jquery-plugin/test.html

    Updated

    here is solution for Firefox 30. little trick for custom select elements in firefox :-moz-any() css pseudo class.

    http://blog.kvijayanand.in/customize-select-arrow-css/

    Detect merged cells in VBA Excel with MergeArea

    While working with selected cells as shown by @tbur can be useful, it's also not the only option available.

    You can use Range() like so:

    If Worksheets("Sheet1").Range("A1").MergeCells Then
      Do something
    Else
      Do something else
    End If
    

    Or:

    If Worksheets("Sheet1").Range("A1:C1").MergeCells Then
      Do something
    Else
      Do something else
    End If
    

    Alternately, you can use Cells():

    If Worksheets("Sheet1").Cells(1, 1).MergeCells Then
      Do something
    Else
      Do something else
    End If
    

    Difference between dict.clear() and assigning {} in Python

    d = {} will create a new instance for d but all other references will still point to the old contents. d.clear() will reset the contents, but all references to the same instance will still be correct.

    Failed to execute 'createObjectURL' on 'URL':

    If you are using ajax, it is possible to add the options xhrFields: { responseType: 'blob' }:

    $.ajax({
      url: 'yourURL',
      type: 'POST',
      data: yourData,
      xhrFields: { responseType: 'blob' },
      success: function (data, textStatus, jqXHR) {
        let src = window.URL.createObjectURL(data);
      }
    });
    

    Java: object to byte[] and byte[] to object converter (for Tokyo Cabinet)

    If your class extends Serializable, you can write and read objects through a ByteArrayOutputStream, that's what I usually do.

    How to get a function name as a string?

    my_function.func_name
    

    There are also other fun properties of functions. Type dir(func_name) to list them. func_name.func_code.co_code is the compiled function, stored as a string.

    import dis
    dis.dis(my_function)
    

    will display the code in almost human readable format. :)

    jQuery DataTable overflow and text-wrapping issues

    The same problem and I solved putting the table between the code

    <div class = "table-responsive"> </ div>
    

    What does "Object reference not set to an instance of an object" mean?

    Another easy way to get this:

     Person myPet = GetPersonFromDatabase();
     // check for myPet == null... AND for myPet.PetType == null
     if ( myPet.PetType == "cat" ) <--- fall down go boom!
    

    ImportError: No module named dateutil.parser

    For Python 3:

    pip3 install python-dateutil
    

    How to check if a DateTime field is not null or empty?

    DateTime is not standard nullable type. If you want assign null to DateTime type of variable, you have to use DateTime? type which supports null value.

    If you only want test your variable to be set (e.g. variable holds other than default value), you can use keyword "default" like in following code:

    if (dateTimeVariable == default(DateTime))
    {
        //do work for dateTimeVariable == null situation
    }
    

    Datatable to html Table

    The first answer is correct, but if you have a large amount of data (in my project I had 8.000 rows * 8 columns) is tragically slow.... Having a string that becomes that large in c# is why that solution is forbiden

    Instead using a large string I used a string array that I join at the end in order to return the string of the html table. Moreover, I used a linq expression ((from o in row.ItemArray select o.ToString()).ToArray()) in order to join each DataRow of the table, instead of looping again, in order to save as much time as possible.

    This is my sample code:

    private string MakeHtmlTable(DataTable data)
    {
                string[] table = new string[data.Rows.Count] ;
                long counter = 1;
                foreach (DataRow row in data.Rows)
                {
                    table[counter-1] = "<tr><td>" + String.Join("</td><td>", (from o in row.ItemArray select o.ToString()).ToArray()) + "</td></tr>";
    
                    counter+=1;
                }
    
                return "</br><table>" + String.Join("", table) + "</table>";
    }
    

    How to put wildcard entry into /etc/hosts?

    It happens that /etc/hosts file doesn't support wild card entries.

    You'll have to use other services like dnsmasq. To enable it in dnsmasq, just edit dnsmasq.conf and add the following line:

    address=/example.com/127.0.0.1
    

    How to change text transparency in HTML/CSS?

    What about the css opacity attribute? 0 to 1 values.

    But then you probably need to use a more explicit dom element than "font". For instance:

    <html><body><span style=\"opacity: 0.5;\"><font color=\"black\" face=\"arial\" size=\"4\">THIS IS MY TEXT</font></span></body></html>
    

    As an additional information I would of course suggest you use CSS declarations outside of your html elements, but as well try to use the font css style instead of the font html tag.

    For cross browser css3 styles generator, have a look at http://css3please.com/

    Applying function with multiple arguments to create a new pandas column

    You can go with @greenAfrican example, if it's possible for you to rewrite your function. But if you don't want to rewrite your function, you can wrap it into anonymous function inside apply, like this:

    >>> def fxy(x, y):
    ...     return x * y
    
    >>> df['newcolumn'] = df.apply(lambda x: fxy(x['A'], x['B']), axis=1)
    >>> df
        A   B  newcolumn
    0  10  20        200
    1  20  30        600
    2  30  10        300
    

    jQuery - Getting the text value of a table cell in the same row as a clicked element

    This will also work

    $(this).parent().parent().find('td').text()
    

    displayname attribute vs display attribute

    I think the current answers are neglecting to highlight the actual important and significant differences and what that means for the intended usage. While they might both work in certain situations because the implementer built in support for both, they have different usage scenarios. Both can annotate properties and methods but here are some important differences:

    DisplayAttribute

    • defined in the System.ComponentModel.DataAnnotations namespace in the System.ComponentModel.DataAnnotations.dll assembly
    • can be used on parameters and fields
    • lets you set additional properties like Description or ShortName
    • can be localized with resources

    DisplayNameAttribute

    • DisplayName is in the System.ComponentModel namespace in System.dll
    • can be used on classes and events
    • cannot be localized with resources

    The assembly and namespace speaks to the intended usage and localization support is the big kicker. DisplayNameAttribute has been around since .NET 2 and seems to have been intended more for naming of developer components and properties in the legacy property grid, not so much for things visible to end users that may need localization and such.

    DisplayAttribute was introduced later in .NET 4 and seems to be designed specifically for labeling members of data classes that will be end-user visible, so it is more suitable for DTOs, entities, and other things of that sort. I find it rather unfortunate that they limited it so it can't be used on classes though.

    EDIT: Looks like latest .NET Core source allows DisplayAttribute to be used on classes now as well.

    PHP error: "The zip extension and unzip command are both missing, skipping."

    Not to belabor the point, but if you are working in a Dockerfile, you would solve this particular issue with Composer by installing the unzip utility. Below is an example using the official PHP image to install unzip and the zip PHP extension for good measure.

    FROM php:7.4-apache
    
    # Install Composer
    COPY --from=composer /usr/bin/composer /usr/bin/composer
    
    # Install unzip utility and libs needed by zip PHP extension 
    RUN apt-get update && apt-get install -y \
        zlib1g-dev \
        libzip-dev \
        unzip
    RUN docker-php-ext-install zip
    

    This is a helpful GitHub issue where the above is lovingly lifted from.

    $_POST vs. $_SERVER['REQUEST_METHOD'] == 'POST'

    It checks whether the page has been called through POST (as opposed to GET, HEAD, etc). When you type a URL in the menu bar, the page is called through GET. However, when you submit a form with method="post" the action page is called with POST.

    OpenCV C++/Obj-C: Detecting a sheet of paper / Square Detection

    What you need is a quadrangle instead of a rotated rectangle. RotatedRect will give you incorrect results. Also you will need a perspective projection.

    Basicly what must been done is:

    • Loop through all polygon segments and connect those which are almost equel.
    • Sort them so you have the 4 most largest line segments.
    • Intersect those lines and you have the 4 most likely corner points.
    • Transform the matrix over the perspective gathered from the corner points and the aspect ratio of the known object.

    I implemented a class Quadrangle which takes care of contour to quadrangle conversion and will also transform it over the right perspective.

    See a working implementation here: Java OpenCV deskewing a contour

    How to represent multiple conditions in a shell if statement?

    Classic technique (escape metacharacters):

    if [ \( "$g" -eq 1 -a "$c" = "123" \) -o \( "$g" -eq 2 -a "$c" = "456" \) ]
    then echo abc
    else echo efg
    fi
    

    I've enclosed the references to $g in double quotes; that's good practice, in general. Strictly, the parentheses aren't needed because the precedence of -a and -o makes it correct even without them.

    Note that the -a and -o operators are part of the POSIX specification for test, aka [, mainly for backwards compatibility (since they were a part of test in 7th Edition UNIX, for example), but they are explicitly marked as 'obsolescent' by POSIX. Bash (see conditional expressions) seems to preempt the classic and POSIX meanings for -a and -o with its own alternative operators that take arguments.


    With some care, you can use the more modern [[ operator, but be aware that the versions in Bash and Korn Shell (for example) need not be identical.

    for g in 1 2 3
    do
        for c in 123 456 789
        do
            if [[ ( "$g" -eq 1 && "$c" = "123" ) || ( "$g" -eq 2 && "$c" = "456" ) ]]
            then echo "g = $g; c = $c; true"
            else echo "g = $g; c = $c; false"
            fi
        done
    done
    

    Example run, using Bash 3.2.57 on Mac OS X:

    g = 1; c = 123; true
    g = 1; c = 456; false
    g = 1; c = 789; false
    g = 2; c = 123; false
    g = 2; c = 456; true
    g = 2; c = 789; false
    g = 3; c = 123; false
    g = 3; c = 456; false
    g = 3; c = 789; false
    

    You don't need to quote the variables in [[ as you do with [ because it is not a separate command in the same way that [ is.


    Isn't it a classic question?

    I would have thought so. However, there is another alternative, namely:

    if [ "$g" -eq 1 -a "$c" = "123" ] || [ "$g" -eq 2 -a "$c" = "456" ]
    then echo abc
    else echo efg
    fi
    

    Indeed, if you read the 'portable shell' guidelines for the autoconf tool or related packages, this notation — using '||' and '&&' — is what they recommend. I suppose you could even go so far as:

    if [ "$g" -eq 1 ] && [ "$c" = "123" ]
    then echo abc
    elif [ "$g" -eq 2 ] && [ "$c" = "456" ]
    then echo abc
    else echo efg
    fi
    

    Where the actions are as trivial as echoing, this isn't bad. When the action block to be repeated is multiple lines, the repetition is too painful and one of the earlier versions is preferable — or you need to wrap the actions into a function that is invoked in the different then blocks.

    How exactly does __attribute__((constructor)) work?

    This page provides great understanding about the constructor and destructor attribute implementation and the sections within within ELF that allow them to work. After digesting the information provided here, I compiled a bit of additional information and (borrowing the section example from Michael Ambrus above) created an example to illustrate the concepts and help my learning. Those results are provided below along with the example source.

    As explained in this thread, the constructor and destructor attributes create entries in the .ctors and .dtors section of the object file. You can place references to functions in either section in one of three ways. (1) using either the section attribute; (2) constructor and destructor attributes or (3) with an inline-assembly call (as referenced the link in Ambrus' answer).

    The use of constructor and destructor attributes allow you to additionally assign a priority to the constructor/destructor to control its order of execution before main() is called or after it returns. The lower the priority value given, the higher the execution priority (lower priorities execute before higher priorities before main() -- and subsequent to higher priorities after main() ). The priority values you give must be greater than100 as the compiler reserves priority values between 0-100 for implementation. Aconstructor or destructor specified with priority executes before a constructor or destructor specified without priority.

    With the 'section' attribute or with inline-assembly, you can also place function references in the .init and .fini ELF code section that will execute before any constructor and after any destructor, respectively. Any functions called by the function reference placed in the .init section, will execute before the function reference itself (as usual).

    I have tried to illustrate each of those in the example below:

    #include <stdio.h>
    #include <stdlib.h>
    
    /*  test function utilizing attribute 'section' ".ctors"/".dtors"
        to create constuctors/destructors without assigned priority.
        (provided by Michael Ambrus in earlier answer)
    */
    
    #define SECTION( S ) __attribute__ ((section ( S )))
    
    void test (void) {
    printf("\n\ttest() utilizing -- (.section .ctors/.dtors) w/o priority\n");
    }
    
    void (*funcptr1)(void) SECTION(".ctors") =test;
    void (*funcptr2)(void) SECTION(".ctors") =test;
    void (*funcptr3)(void) SECTION(".dtors") =test;
    
    /*  functions constructX, destructX use attributes 'constructor' and
        'destructor' to create prioritized entries in the .ctors, .dtors
        ELF sections, respectively.
    
        NOTE: priorities 0-100 are reserved
    */
    void construct1 () __attribute__ ((constructor (101)));
    void construct2 () __attribute__ ((constructor (102)));
    void destruct1 () __attribute__ ((destructor (101)));
    void destruct2 () __attribute__ ((destructor (102)));
    
    /*  init_some_function() - called by elf_init()
    */
    int init_some_function () {
        printf ("\n  init_some_function() called by elf_init()\n");
        return 1;
    }
    
    /*  elf_init uses inline-assembly to place itself in the ELF .init section.
    */
    int elf_init (void)
    {
        __asm__ (".section .init \n call elf_init \n .section .text\n");
    
        if(!init_some_function ())
        {
            exit (1);
        }
    
        printf ("\n    elf_init() -- (.section .init)\n");
    
        return 1;
    }
    
    /*
        function definitions for constructX and destructX
    */
    void construct1 () {
        printf ("\n      construct1() constructor -- (.section .ctors) priority 101\n");
    }
    
    void construct2 () {
        printf ("\n      construct2() constructor -- (.section .ctors) priority 102\n");
    }
    
    void destruct1 () {
        printf ("\n      destruct1() destructor -- (.section .dtors) priority 101\n\n");
    }
    
    void destruct2 () {
        printf ("\n      destruct2() destructor -- (.section .dtors) priority 102\n");
    }
    
    /* main makes no function call to any of the functions declared above
    */
    int
    main (int argc, char *argv[]) {
    
        printf ("\n\t  [ main body of program ]\n");
    
        return 0;
    }
    

    output:

    init_some_function() called by elf_init()
    
        elf_init() -- (.section .init)
    
        construct1() constructor -- (.section .ctors) priority 101
    
        construct2() constructor -- (.section .ctors) priority 102
    
            test() utilizing -- (.section .ctors/.dtors) w/o priority
    
            test() utilizing -- (.section .ctors/.dtors) w/o priority
    
            [ main body of program ]
    
            test() utilizing -- (.section .ctors/.dtors) w/o priority
    
        destruct2() destructor -- (.section .dtors) priority 102
    
        destruct1() destructor -- (.section .dtors) priority 101
    

    The example helped cement the constructor/destructor behavior, hopefully it will be useful to others as well.

    Reusing a PreparedStatement multiple times

    The loop in your code is only an over-simplified example, right?

    It would be better to create the PreparedStatement only once, and re-use it over and over again in the loop.

    In situations where that is not possible (because it complicated the program flow too much), it is still beneficial to use a PreparedStatement, even if you use it only once, because the server-side of the work (parsing the SQL and caching the execution plan), will still be reduced.

    To address the situation that you want to re-use the Java-side PreparedStatement, some JDBC drivers (such as Oracle) have a caching feature: If you create a PreparedStatement for the same SQL on the same connection, it will give you the same (cached) instance.

    About multi-threading: I do not think JDBC connections can be shared across multiple threads (i.e. used concurrently by multiple threads) anyway. Every thread should get his own connection from the pool, use it, and return it to the pool again.

    Setting a timeout for socket operations

    You could use the following solution:

    SocketAddress sockaddr = new InetSocketAddress(ip, port);
    // Create your socket
    Socket socket = new Socket();
    // Connect with 10 s timeout
    socket.connect(sockaddr, 10000);
    

    Hope it helps!

    How can I prevent the textarea from stretching beyond his parent DIV element? (google-chrome issue only)

    textarea {
    width: 700px;  
    height: 100px;
    resize: none; }
    

    assign your required width and height for the textarea and then use. resize: none ; css property which will disable the textarea's stretchable property.

    (Built-in) way in JavaScript to check if a string is a valid number

    Save yourself the headache of trying to find a "built-in" solution.

    There isn't a good answer, and the hugely upvoted answer in this thread is wrong.

    npm install is-number

    In JavaScript, it's not always as straightforward as it should be to reliably check if a value is a number. It's common for devs to use +, -, or Number() to cast a string value to a number (for example, when values are returned from user input, regex matches, parsers, etc). But there are many non-intuitive edge cases that yield unexpected results:

    console.log(+[]); //=> 0
    console.log(+''); //=> 0
    console.log(+'   '); //=> 0
    console.log(typeof NaN); //=> 'number'
    

    Creating a byte array from a stream

    You can simply use ToArray() method of MemoryStream class, for ex-

    MemoryStream ms = (MemoryStream)dataInStream;
    byte[] imageBytes = ms.ToArray();
    

    how to reset <input type = "file">

    I miss an other Solution here (2021): I use FileList to interact with file input.

    Since there is no way to create a FileList object, I use DataTransfer, that brings clean FilleList with it.

    I reset it with:

      file_input.files=new DataTransfer().files  
    

    In my case this perfectly fits, since I interact only via FileList with my encapsulated file input element.

    HTML5 validation when the input type is not "submit"

    I may be late, but the way I did it was to create a hidden submit input, and calling it's click handler upon submit. Something like (using jquery for simplicity):

    <input type="text" id="example" name="example" value="" required>
    <button type="button"  onclick="submitform()" id="save">Save</button>
    <input id="submit_handle" type="submit" style="display: none">
    
    <script>
    function submitform() {
        $('#submit_handle').click();
    }
    </script>
    

    HTTP POST Returns Error: 417 "Expectation Failed."

    System.Net.HttpWebRequest adds the header 'HTTP header "Expect: 100-Continue"' to every request unless you explicitly ask it not to by setting this static property to false:

    System.Net.ServicePointManager.Expect100Continue = false;
    

    Some servers choke on that header and send back the 417 error you're seeing.

    Give that a shot.

    C - gettimeofday for computing time?

    The answer offered by @Daniel Kamil Kozar is the correct answer - gettimeofday actually should not be used to measure the elapsed time. Use clock_gettime(CLOCK_MONOTONIC) instead.


    Man Pages say - The time returned by gettimeofday() is affected by discontinuous jumps in the system time (e.g., if the system administrator manually changes the system time). If you need a monotonically increasing clock, see clock_gettime(2).

    The Opengroup says - Applications should use the clock_gettime() function instead of the obsolescent gettimeofday() function.

    Everyone seems to love gettimeofday until they run into a case where it does not work or is not there (VxWorks) ... clock_gettime is fantastically awesome and portable.

    <<

    Setting new value for an attribute using jQuery

    Works fine for me

    See example here. http://jsfiddle.net/blowsie/c6VAy/

    Make sure your jquery is inside $(document).ready function or similar.

    Also you can improve your code by using jquery data

    $('#amount').data('min','1000');
    
    <div id="amount" data-min=""></div>
    

    Update,

    A working example of your full code (pretty much) here. http://jsfiddle.net/blowsie/c6VAy/3/

    Understanding the difference between Object.create() and new SomeFunction()

    Object.create(Constructor.prototype) is the part of new Constructor

    this is new Constructor implementation

    // 1. define constructor function
    
          function myConstructor(name, age) {
            this.name = name;
            this.age = age;
          }
          myConstructor.prototype.greet = function(){
            console.log(this.name, this.age)
          };
    
    // 2. new operator implementation
    
          let newOperatorWithConstructor = function(name, age) {
            const newInstance = new Object(); // empty object
            Object.setPrototypeOf(newInstance, myConstructor.prototype); // set prototype
    
            const bindedConstructor = myConstructor.bind(newInstance); // this binding
            bindedConstructor(name, age); // execute binded constructor function
    
            return newInstance; // return instance
          };
    
    // 3. produce new instance
    
          const instance = new myConstructor("jun", 28);
          const instance2 = newOperatorWithConstructor("jun", 28);
          console.log(instance);
          console.log(instance2);
          
    

    new Constructor implementation contains Object.create method

          newOperatorWithConstructor = function(name, age) {
            const newInstance = Object.create(myConstructor.prototype); // empty object, prototype chaining
    
            const bindedConstructor = myConstructor.bind(newInstance); // this binding
            bindedConstructor(name, age); // execute binded constructor function
    
            return newInstance; // return instance
          };
    
          console.log(newOperatorWithConstructor("jun", 28));
    

    IOPub data rate exceeded in Jupyter notebook (when viewing image)

    Some additional advice for Windows(10) users:

    1. If you are using Anaconda Prompt/PowerShell for the first time, type "Anaconda" in the search field of your Windows task bar and you will see the suggested software.
    2. Make sure to open the Anaconda prompt as administrator.
    3. Always navigate to your user directory or the directory with your Jupyter Notebook files first before running the command. Otherwise you might end up somewhere in your system files and be confused by an unfamiliar file tree.

    The correct way to open Jupyter notebook with new data limit from the Anaconda Prompt on my own Windows 10 PC is:

    (base) C:\Users\mobarget\Google Drive\Jupyter Notebook>jupyter notebook --NotebookApp.iopub_data_rate_limit=1.0e10
    

    Angular (4, 5, 6, 7) - Simple example of slide in out animation on ngIf

    The most upvoted answer is not implementing a real slide in/out (or down/up), as:

    1. It's not doing a soft transition on the height attribute. At time zero the element already has the 100% of its height producing a sudden glitch on the elements below it.
    2. When sliding out/up, the element does a translateY(-100%) and then suddenly disappears, causing another glitch on the elements below it.

    You can implement a slide in and slide out like so:

    my-component.ts

    import { animate, style, transition, trigger } from '@angular/animations';
    
    @Component({
      ...
      animations: [
        trigger('slideDownUp', [
          transition(':enter', [style({ height: 0 }), animate(500)]),
          transition(':leave', [animate(500, style({ height: 0 }))]),
        ]),
      ],
    })
    

    my-component.html

    <div @slideDownUp *ngIf="isShowing" class="box">
      I am the content of the div!
    </div>
    

    my-component.scss

    .box {
      overflow: hidden;
    }
    

    How can I add additional PHP versions to MAMP

    The easiest solution I found is to just rename the php folder version as such:

    1. Shut down the servers
    2. Rename the folder containing the php version that you don't need in /Applications/MAMP/bin/php. php7.3.9 --> _php7.3.9

    That way only two of them will be read by MAMP. Done!

    Which is the fastest algorithm to find prime numbers?

    A very fast implementation of the Sieve of Atkin is Dan Bernstein's primegen. This sieve is more efficient than the Sieve of Eratosthenes. His page has some benchmark information.

    TypeError: ufunc 'add' did not contain a loop with signature matching types

    You have a numpy array of strings, not floats. This is what is meant by dtype('<U9') -- a little endian encoded unicode string with up to 9 characters.

    try:

    return sum(np.asarray(listOfEmb, dtype=float)) / float(len(listOfEmb))
    

    However, you don't need numpy here at all. You can really just do:

    return sum(float(embedding) for embedding in listOfEmb) / len(listOfEmb)
    

    Or if you're really set on using numpy.

    return np.asarray(listOfEmb, dtype=float).mean()
    

    Is there an easy way to check the .NET Framework version?

    You can get a useful string without having to touch the registry or reference assemblies which may or may not be loaded. mscorlib.dll and other System assemblies have AssemblyFileVersionAttribute defined, and it seems to be unique for each version of .NET, based on the reference assemblies provided with Visual Studio.

    string version = (typeof(string).Assembly
        .GetCustomAttributes(typeof(AssemblyFileVersionAttribute), false)
        .FirstOrDefault() as AssemblyFileVersionAttribute)?.Version;
    

    Version 4.5 is a bit off, because it's marked 4.0 in that version, but 4.6 onward appear to have the minor version matching at least. Doing it this way seems like it would be more future proof than depending on some installer registry key and having to compare against a fixed set of values.

    I found the reference assemblies here:

    C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework
    

    Where I got the following versions:

    4.0 = 4.0.30319.1
    4.5 = 4.0.30319.18020
    4.5.1 = 4.0.30319.18402
    4.5.2 = 4.0.30319.34211
    4.6 = 4.6.81.0
    4.6.1 = 4.6.1055.0
    4.7.2 = 4.7.3062.0
    4.8 = 4.8.3761.0
    

    AutoComplete TextBox Control

    There are two ways to accomplish this textbox effect:

    enter image description here

    Either using the graphic user interface (GUI); or with code

    Using the Graphic User Interface:
    Go to: "Properties" Tab; then set the following properties:

    enter image description here

    However; the best way is to create this by code. See example below.

    AutoCompleteStringCollection sourceName = new AutoCompleteStringCollection();
    
    foreach (string name in listNames)
    {    
        sourceName.Add(name);
    }
    
    txtName.AutoCompleteCustomSource = sourceName;
    txtName.AutoCompleteMode = AutoCompleteMode.Suggest;
    txtName.AutoCompleteSource = AutoCompleteSource.CustomSource;
    

    integrating barcode scanner into php application?

    If you have Bluetooth, Use twedge on windows and getblue app on android, they also have a few videos of it. It's made by TEC-IT. I've got it to work by setting the interface option to bluetooth server in TWedge and setting the output setting in getblue to Bluetooth client and selecting my computer from the Bluetooth devices list. Make sure your computer and phone is paired. Also to get the barcode as input set the action setting in TWedge to Keyboard Wedge. This will allow for you to first click the input text box on said form, then scan said product with your phone and wait a sec for the barcode number to be put into the text box. Using this method requires no php that doesn't already exist in your current form processing, just process the text box as usual and viola your phone scans bar codes, sends them to your pc via Bluetooth wirelessly, your computer inserts the barcode into whatever text field is selected in any application or website. Hope this helps.

    How to revert a "git rm -r ."?

    undo git rm

    git rm file             # delete file & update index
    git checkout HEAD file  # restore file & index from HEAD
    

    undo git rm -r

    git rm -r dir          # delete tracked files in dir & update index
    git checkout HEAD dir  # restore file & index from HEAD
    

    undo git rm -rf

    git rm -r dir          # delete tracked files & delete uncommitted changes
    not possible           # `uncommitted changes` can not be restored.
    

    Uncommitted changes includes not staged changes, staged changes but not committed.