Programs & Examples On #Hg git

A tool for communicating changes between mercurial and git.

Curl : connection refused

Make sure you have a service started and listening on the port.

netstat -ln | grep 8080

and

sudo netstat -tulpn

How to redirect a page using onclick event in php?

You can't use php code client-side. You need to use javascript.

<input type="button" value="Home" class="homebutton" id="btnHome" 
onClick="document.location.href='some/page'" />

However, you really shouldn't be using inline js (like onclick here). Study about this here: https://www.google.com/search?q=Why+is+inline+js+bad%3F

Here's a clean way of doing this: Live demo (click).

Markup:

<button id="myBtn">Redirect</button>

JavaScript:

var btn = document.getElementById('myBtn');
btn.addEventListener('click', function() {
  document.location.href = 'some/page';
});

If you need to write in the location with php:

  <button id="myBtn">Redirect</button>
  <script>
    var btn = document.getElementById('myBtn');
    btn.addEventListener('click', function() {
      document.location.href = '<?php echo $page; ?>';
    });
  </script>

Error 5 : Access Denied when starting windows service

Use LocalSystem Account instead of LocalService Account in Service Installer.

You can do this either from doing below change in design view of your service installer:
Properties of Service Process Installer -> Set Account to LocalSystem.

or by doing below change in in designer.cs file of your service installer:

this.serviceProcessInstaller1.Account = System.ServiceProcess.ServiceAccount.LocalSystem;

How to avoid the need to specify the WSDL location in a CXF or JAX-WS generated webservice client?

For those using org.jvnet.jax-ws-commons:jaxws-maven-plugin to generate a client from WSDL at build-time:

  • Place the WSDL somewhere in your src/main/resources
  • Do not prefix the wsdlLocation with classpath:
  • Do prefix the wsdlLocation with /

Example:

  • WSDL is stored in /src/main/resources/foo/bar.wsdl
  • Configure jaxws-maven-plugin with <wsdlDirectory>${basedir}/src/main/resources/foo</wsdlDirectory> and <wsdlLocation>/foo/bar.wsdl</wsdlLocation>

set the width of select2 input (through Angular-ui directive)

Wanted to add my solution here as well. This is similar to Ravindu's answer above.

I added width: 'resolve', as a property within the select2:

    $('#searchFilter').select2({
        width: 'resolve',
    });

Then I added a min-width property to select2-container with !important:

.select2-container {
    min-width: 100% !important;
}

On the select element, the style='100px !important;' attribute needed !important to work:

<select class="form-control" style="width: 160px;" id="searchFilter" name="searchfilter[]">

Usage of @see in JavaDoc?

@see is useful for information about related methods/classes in an API. It will produce a link to the referenced method/code on the documentation. Use it when there is related code that might help the user understand how to use the API.

Does Java SE 8 have Pairs or Tuples?

Since you only care about the indexes, you don't need to map to tuples at all. Why not just write a filter that uses the looks up elements in your array?

     int[] value =  ...


IntStream.range(0, value.length)
            .filter(i -> value[i] > 30)  //or whatever filter you want
            .forEach(i -> System.out.println(i));

A message body writer for Java type, class myPackage.B, and MIME media type, application/octet-stream, was not found

i was facing the same problem for a get method i was returning an "int" for the @get method Strangely when i change the return type to String the error was gone.Give it a try and if someone knows the logic behind it kindly share it

How to "git show" a merge commit with combined diff output even when every changed file agrees with one of the parents?

in your case you just need to

git diff HEAD^ HEAD^2

or just hash for you commit:

git diff 0e1329e55^ 0e1329e55^2

Width equal to content

Try using a <span> element instead. Or if you prefer, try display:inline

Converting a string to a date in JavaScript

function stringToDate(_date,_format,_delimiter)
{
            var formatLowerCase=_format.toLowerCase();
            var formatItems=formatLowerCase.split(_delimiter);
            var dateItems=_date.split(_delimiter);
            var monthIndex=formatItems.indexOf("mm");
            var dayIndex=formatItems.indexOf("dd");
            var yearIndex=formatItems.indexOf("yyyy");
            var month=parseInt(dateItems[monthIndex]);
            month-=1;
            var formatedDate = new Date(dateItems[yearIndex],month,dateItems[dayIndex]);
            return formatedDate;
}

stringToDate("17/9/2014","dd/MM/yyyy","/");
stringToDate("9/17/2014","mm/dd/yyyy","/")
stringToDate("9-17-2014","mm-dd-yyyy","-")

Android - Best and safe way to stop thread

The Thread.stop() method that could be used to stop a thread has been deprecated; for more info see; Why are Thread.stop, Thread.suspend and Thread.resume Deprecated?.

Your best bet is to have a variable which the thread itself consults, and voluntarily exits if the variable equals a certain value. You then manipulate the variable inside your code when you want the thread to exit. Alternately of course, you can use an AsyncTask instead.

jquery disable form submit on enter

$(document).on('keyup keypress', 'form input[type="text"]', function(e) {
  if(e.which == 13) {
    e.preventDefault();
    return false;
  }
});

This solution works on all forms on website (also on forms inserted with ajax), preventing only Enters in input texts. Place it in a document ready function, and forget this problem for a life.

Setting the focus to a text field

I have had a similar scenario where I needed to set the focus on a text box within a panel when the panel was shown. The panel was loaded on application startup, so I couldn't set the focus in the constructor. As the panel wasn't being loaded or being given focus on show, this meant that I had no event to fire the focus request from.

To solve this, I added a global method to my main that called a method in the panel that invoked requestFocusInWindow() on the text area. I put the call to the global method in the button that showed the panel, after the call to show. This meant that the panel would be shown and then the text area assigned the focus after showing the panel. Hope that makes sense and helps!

Also, you can edit most of the auto-generated code by right clicking on the object in design view and selecting customize code, however I don't think that it allows you to edit panels.

Get top first record from duplicate records having no unique identity

Find all products that has been ordered 1 or more times... (kind of duplicate records)

SELECT DISTINCT * from [order_items] where productid in 
(SELECT productid 
  FROM [order_items]
  group by productid 
  having COUNT(*)>0)
order by productid 

To select the last inserted of those...

SELECT DISTINCT productid, MAX(id) OVER (PARTITION BY productid) AS LastRowId from [order_items] where productid in 
(SELECT productid 
  FROM [order_items]
  group by productid 
  having COUNT(*)>0)
order by productid 

Converting file size in bytes to human-readable string

Based on cocco's idea, here's a less compact -but hopefully more comprehensive- example.

<!DOCTYPE html>
<html>
<head>
<title>File info</title>

<script>
<!--
function fileSize(bytes) {
    var exp = Math.log(bytes) / Math.log(1024) | 0;
    var result = (bytes / Math.pow(1024, exp)).toFixed(2);

    return result + ' ' + (exp == 0 ? 'bytes': 'KMGTPEZY'[exp - 1] + 'B');
}

function info(input) {
    input.nextElementSibling.textContent = fileSize(input.files[0].size);
} 
-->
</script>
</head>

<body>
<label for="upload-file"> File: </label>
<input id="upload-file" type="file" onchange="info(this)">
<div></div>
</body>
</html> 

How do you refresh the MySQL configuration file without restarting?

Specific actions you can do from SQL client and you don't need to restart anything:

SET GLOBAL log = 'ON';
FLUSH LOGS;

CSS selector - element with a given child

I agree that it is not possible in general.

The only thing CSS3 can do (which helped in my case) is to select elements that have no children:

table td:empty
{
   background-color: white;
}

Or have any children (including text):

table td:not(:empty)
{
   background-color: white;
}

Volatile vs Static in Java

Declaring a static variable in Java, means that there will be only one copy, no matter how many objects of the class are created. The variable will be accessible even with no Objects created at all. However, threads may have locally cached values of it.

When a variable is volatile and not static, there will be one variable for each Object. So, on the surface it seems there is no difference from a normal variable but totally different from static. However, even with Object fields, a thread may cache a variable value locally.

This means that if two threads update a variable of the same Object concurrently, and the variable is not declared volatile, there could be a case in which one of the thread has in cache an old value.

Even if you access a static value through multiple threads, each thread can have its local cached copy! To avoid this you can declare the variable as static volatile and this will force the thread to read each time the global value.

However, volatile is not a substitute for proper synchronisation!
For instance:

private static volatile int counter = 0;

private void concurrentMethodWrong() {
  counter = counter + 5;
  //do something
  counter = counter - 5;
}

Executing concurrentMethodWrong concurrently many times may lead to a final value of counter different from zero!
To solve the problem, you have to implement a lock:

private static final Object counterLock = new Object();

private static volatile int counter = 0;

private void concurrentMethodRight() {
  synchronized (counterLock) {
    counter = counter + 5;
  }
  //do something
  synchronized (counterLock) {
    counter = counter - 5;
  }
}

Or use the AtomicInteger class.

SQL select statements with multiple tables

Like that:

SELECT p.*, a.street, a.city FROM persons AS p
JOIN address AS a ON p.id = a.person_id
WHERE a.zip = '97299'

How to uninstall a windows service and delete its files without rebooting

I had sort of the same problem as you. I have a system service that i want to uninstall and afterwards reinstall as part of an update. On certain systems this would not work without a reboot. The problem was that a call to DeleteService() would return ok, but the following call to CreateService() would tell me the service was still there, but marked for deletion (error code 1072). The registry would reflect that, since the subkey was still there (under HKLM\System\CurrentControlSet\Services), but "DeleteFlag" was set to 1. From that point on, only a reboot could fix the situation.

Some things that don't work:

  • Using "sc delete": it had the same problems as I. The call would return ok, but the service was not really gone and still in the registry with DeleteFlag = 1.
  • Deleting the key in the registry. The Service Manager seems to keep a database in memory and the registry is just a copy of it for the next boot.
  • Adding wait loops, waiting for .exe files to be ready to be overwritten, killing the process, etc.
  • Closing handles to the service. Which ones??

But here is what worked:

I noticed in some articles here on stackoverflow that net.exe has start/stop features as well (I only knew of sc.exe utility). And strangely enough, a "net stop svcname" plus a "sc delete svcname" worked! So net.exe must do something I don't do.

But net.exe doesn't contain an import to ControlService(), so how does it stop the service? I found out that net.exe spawns net1.exe, but net1.exe doesn't import ControlService() as well. I used the great API Monitor utility ( http://www.rohitab.com/apimonitor ) to see what net1.exe is doing, but it never called anything that looked promising.

But then I saw that it imports NetServiceControl() from NETAPI32.DLL (that had at least "Service" in its name!). MSDN says that this function is obsolete. Nevertheless, I found the prototype in LMSvc.h and some parameter description here: http://cyberkinetica.homeunix.net/os2tk45/srvfpgr/369_L2_NetServiceControlorN.html . When you load NETAPI32.DLL and use NetServiceControl(NULL, service_name, 3, 0, 0) (3 is for SERVICE_CTRL_UNINSTALL, which is used to stop) the service is stopped afterwards. And it can be deleted and reinstalled afterwards without DeleteFlag or reboot!

So it was never a problem of deleting, but of stopping the service properly. And NetServiceControl() does the trick. Sorry for the long post, but I thought it might help someone with similar problems. (Just for reference, I use Win7 SP1 x64.)

how to avoid extra blank page at end while printing?

First, emulate the print stylesheet via your browser's devtools. Instructions can be found here.

Then you'll want to look for extra padding, margin, borders, etc that could be extending the dimensions of your pages beyond the 8.5in x 11in. Pay special attention to whitespace as this will be impossible to detect via the print preview dialog. If there is whitespace that shouldn't be there, right-clicking and inspecting the element under the cursor should highlight the issue (unless it's a margin causing it).

What is the difference between SQL and MySQL?

SQL stands for Structured Query Language, and it is a programming language designed for querying data from a database. MySQL is a relational database management system, which is a completely different thing.

MySQL is an open-source platform that uses SQL, just like MSSQL, which is Microsoft's product (not open-source) that uses SQL for database management.

AWK to print field $2 first, then field $1

Use a dot or a pipe as the field separator:

awk -v FS='[.|]' '{
    printf "%s%s %s.%s\n", toupper(substr($4,1,1)), substr($4,2), $1, $2
}' << END
[email protected]|com.emailclient.account
[email protected]|com.socialsite.auth.account
END

gives:

Emailclient [email protected]
Socialsite [email protected]

NPM clean modules

There is actually special command for this job

npm ci

It will delete node_modules directory and will install packages with respect your package-lock.json file

More info: https://docs.npmjs.com/cli/ci.html

SQLiteDatabase.query method

tableColumns

  • null for all columns as in SELECT * FROM ...
  • new String[] { "column1", "column2", ... } for specific columns as in SELECT column1, column2 FROM ... - you can also put complex expressions here:
    new String[] { "(SELECT max(column1) FROM table1) AS max" } would give you a column named max holding the max value of column1

whereClause

  • the part you put after WHERE without that keyword, e.g. "column1 > 5"
  • should include ? for things that are dynamic, e.g. "column1=?" -> see whereArgs

whereArgs

  • specify the content that fills each ? in whereClause in the order they appear

the others

  • just like whereClause the statement after the keyword or null if you don't use it.

Example

String[] tableColumns = new String[] {
    "column1",
    "(SELECT max(column1) FROM table2) AS max"
};
String whereClause = "column1 = ? OR column1 = ?";
String[] whereArgs = new String[] {
    "value1",
    "value2"
};
String orderBy = "column1";
Cursor c = sqLiteDatabase.query("table1", tableColumns, whereClause, whereArgs,
        null, null, orderBy);

// since we have a named column we can do
int idx = c.getColumnIndex("max");

is equivalent to the following raw query

String queryString =
    "SELECT column1, (SELECT max(column1) FROM table1) AS max FROM table1 " +
    "WHERE column1 = ? OR column1 = ? ORDER BY column1";
sqLiteDatabase.rawQuery(queryString, whereArgs);

By using the Where/Bind -Args version you get automatically escaped values and you don't have to worry if input-data contains '.

Unsafe: String whereClause = "column1='" + value + "'";
Safe: String whereClause = "column1=?";

because if value contains a ' your statement either breaks and you get exceptions or does unintended things, for example value = "XYZ'; DROP TABLE table1;--" might even drop your table since the statement would become two statements and a comment:

SELECT * FROM table1 where column1='XYZ'; DROP TABLE table1;--'

using the args version XYZ'; DROP TABLE table1;-- would be escaped to 'XYZ''; DROP TABLE table1;--' and would only be treated as a value. Even if the ' is not intended to do bad things it is still quite common that people have it in their names or use it in texts, filenames, passwords etc. So always use the args version. (It is okay to build int and other primitives directly into whereClause though)

Best practices for catching and re-throwing .NET exceptions

Actually, there are some situations which the throw statment will not preserve the StackTrace information. For example, in the code below:

try
{
  int i = 0;
  int j = 12 / i; // Line 47
  int k = j + 1;
}
catch
{
  // do something
  // ...
  throw; // Line 54
}

The StackTrace will indicate that line 54 raised the exception, although it was raised at line 47.

Unhandled Exception: System.DivideByZeroException: Attempted to divide by zero.
   at Program.WithThrowIncomplete() in Program.cs:line 54
   at Program.Main(String[] args) in Program.cs:line 106

In situations like the one described above, there are two options to preseve the original StackTrace:

Calling the Exception.InternalPreserveStackTrace

As it is a private method, it has to be invoked by using reflection:

private static void PreserveStackTrace(Exception exception)
{
  MethodInfo preserveStackTrace = typeof(Exception).GetMethod("InternalPreserveStackTrace",
    BindingFlags.Instance | BindingFlags.NonPublic);
  preserveStackTrace.Invoke(exception, null);
}

I has a disadvantage of relying on a private method to preserve the StackTrace information. It can be changed in future versions of .NET Framework. The code example above and proposed solution below was extracted from Fabrice MARGUERIE weblog.

Calling Exception.SetObjectData

The technique below was suggested by Anton Tykhyy as answer to In C#, how can I rethrow InnerException without losing stack trace question.

static void PreserveStackTrace (Exception e) 
{ 
  var ctx = new StreamingContext  (StreamingContextStates.CrossAppDomain) ; 
  var mgr = new ObjectManager     (null, ctx) ; 
  var si  = new SerializationInfo (e.GetType (), new FormatterConverter ()) ; 

  e.GetObjectData    (si, ctx)  ; 
  mgr.RegisterObject (e, 1, si) ; // prepare for SetObjectData 
  mgr.DoFixups       ()         ; // ObjectManager calls SetObjectData 

  // voila, e is unmodified save for _remoteStackTraceString 
} 

Although, it has the advantage of relying in public methods only it also depends on the following exception constructor (which some exceptions developed by 3rd parties do not implement):

protected Exception(
    SerializationInfo info,
    StreamingContext context
)

In my situation, I had to choose the first approach, because the exceptions raised by a 3rd-party library I was using didn't implement this constructor.

JavaScript hard refresh of current page

Try to use:

location.reload(true);

When this method receives a true value as argument, it will cause the page to always be reloaded from the server. If it is false or not specified, the browser may reload the page from its cache.

More info:

Sort table rows In Bootstrap

These examples are minified because StackOverflow has a maximum character limit and links to external code are discouraged since links can break.

There are multiple plugins if you look: Bootstrap Sortable, Bootstrap Table or DataTables.

Bootstrap 3 with DataTables Example: Bootstrap Docs & DataTables Docs

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$(document).ready(function() {
  $('#example').DataTable();
});
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<link href=https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.4.1/css/bootstrap.min.css rel=stylesheet><link href=https://cdnjs.cloudflare.com/ajax/libs/datatables/1.10.20/css/dataTables.bootstrap.min.css rel=stylesheet><div class=container><h1>Bootstrap 3 DataTables</h1><table cellspacing=0 class="table table-bordered table-hover table-striped"id=example width=100%><thead><tr><th>Name<th>Position<th>Office<th>Salary<tbody><tr><td>Tiger Nixon<td>System Architect<td>Edinburgh<td>$320,800<tr><td>Garrett Winters<td>Accountant<td>Tokyo<td>$170,750<tr><td>Ashton Cox<td>Junior Technical Author<td>San Francisco<td>$86,000<tr><td>Cedric Kelly<td>Senior Javascript Developer<td>Edinburgh<td>$433,060<tr><td>Airi Satou<td>Accountant<td>Tokyo<td>$162,700<tr><td>Brielle Williamson<td>Integration Specialist<td>New York<td>$372,000<tr><td>Herrod Chandler<td>Sales Assistant<td>San Francisco<td>$137,500<tr><td>Rhona Davidson<td>Integration Specialist<td>Tokyo<td>$327,900<tr><td>Colleen Hurst<td>Javascript Developer<td>San Francisco<td>$205,500<tr><td>Sonya Frost<td>Software Engineer<td>Edinburgh<td>$103,600<tr><td>Jena Gaines<td>Office Manager<td>London<td>$90,560<tr><td>Quinn Flynn<td>Support Lead<td>Edinburgh<td>$342,000<tr><td>Charde Marshall<td>Regional Director<td>San Francisco<td>$470,600<tr><td>Haley Kennedy<td>Senior Marketing Designer<td>London<td>$313,500<tr><td>Tatyana Fitzpatrick<td>Regional Director<td>London<td>$385,750<tr><td>Michael Silva<td>Marketing Designer<td>London<td>$198,500<tr><td>Paul Byrd<td>Chief Financial Officer (CFO)<td>New York<td>$725,000<tr><td>Gloria Little<td>Systems Administrator<td>New York<td>$237,500<tr><td>Bradley Greer<td>Software Engineer<td>London<td>$132,000<tr><td>Dai Rios<td>Personnel Lead<td>Edinburgh<td>$217,500<tr><td>Jenette Caldwell<td>Development Lead<td>New York<td>$345,000<tr><td>Yuri Berry<td>Chief Marketing Officer (CMO)<td>New York<td>$675,000<tr><td>Caesar Vance<td>Pre-Sales Support<td>New York<td>$106,450<tr><td>Doris Wilder<td>Sales Assistant<td>Sidney<td>$85,600<tr><td>Angelica Ramos<td>Chief Executive Officer (CEO)<td>London<td>$1,200,000<tr><td>Gavin Joyce<td>Developer<td>Edinburgh<td>$92,575<tr><td>Jennifer Chang<td>Regional Director<td>Singapore<td>$357,650<tr><td>Brenden Wagner<td>Software Engineer<td>San Francisco<td>$206,850<tr><td>Fiona Green<td>Chief Operating Officer (COO)<td>San Francisco<td>$850,000<tr><td>Shou Itou<td>Regional Marketing<td>Tokyo<td>$163,000<tr><td>Michelle House<td>Integration Specialist<td>Sidney<td>$95,400<tr><td>Suki Burks<td>Developer<td>London<td>$114,500<tr><td>Prescott Bartlett<td>Technical Author<td>London<td>$145,000<tr><td>Gavin Cortez<td>Team Leader<td>San Francisco<td>$235,500<tr><td>Martena Mccray<td>Post-Sales support<td>Edinburgh<td>$324,050<tr><td>Unity Butler<td>Marketing Designer<td>San Francisco<td>$85,675<tr><td>Howard Hatfield<td>Office Manager<td>San Francisco<td>$164,500<tr><td>Hope Fuentes<td>Secretary<td>San Francisco<td>$109,850<tr><td>Vivian Harrell<td>Financial Controller<td>San Francisco<td>$452,500<tr><td>Timothy Mooney<td>Office Manager<td>London<td>$136,200<tr><td>Jackson Bradshaw<td>Director<td>New York<td>$645,750<tr><td>Olivia Liang<td>Support Engineer<td>Singapore<td>$234,500<tr><td>Bruno Nash<td>Software Engineer<td>London<td>$163,500<tr><td>Sakura Yamamoto<td>Support Engineer<td>Tokyo<td>$139,575<tr><td>Thor Walton<td>Developer<td>New York<td>$98,540<tr><td>Finn Camacho<td>Support Engineer<td>San Francisco<td>$87,500<tr><td>Serge Baldwin<td>Data Coordinator<td>Singapore<td>$138,575<tr><td>Zenaida Frank<td>Software Engineer<td>New York<td>$125,250<tr><td>Zorita Serrano<td>Software Engineer<td>San Francisco<td>$115,000<tr><td>Jennifer Acosta<td>Junior Javascript Developer<td>Edinburgh<td>$75,650<tr><td>Cara Stevens<td>Sales Assistant<td>New York<td>$145,600<tr><td>Hermione Butler<td>Regional Director<td>London<td>$356,250<tr><td>Lael Greer<td>Systems Administrator<td>London<td>$103,500<tr><td>Jonas Alexander<td>Developer<td>San Francisco<td>$86,500<tr><td>Shad Decker<td>Regional Director<td>Edinburgh<td>$183,000<tr><td>Michael Bruce<td>Javascript Developer<td>Singapore<td>$183,000<tr><td>Donna Snider<td>Customer Support<td>New York<td>$112,000</table></div><script src=https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js></script><script src=https://cdnjs.cloudflare.com/ajax/libs/datatables/1.10.20/js/jquery.dataTables.min.js></script><script src=https://cdnjs.cloudflare.com/ajax/libs/datatables/1.10.20/js/dataTables.bootstrap.min.js></script>
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Bootstrap 4 with DataTables Example: Bootstrap Docs & DataTables Docs

_x000D_
_x000D_
$(document).ready(function() {
  $('#example').DataTable();
});
_x000D_
<link href=https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.5.0/css/bootstrap.min.css rel=stylesheet><link href=https://cdnjs.cloudflare.com/ajax/libs/datatables/1.10.20/css/dataTables.bootstrap4.min.css rel=stylesheet><div class=container><h1>Bootstrap 4 DataTables</h1><table cellspacing=0 class="table table-bordered table-hover table-inverse table-striped"id=example width=100%><thead><tr><th>Name<th>Position<th>Office<th>Age<th>Start date<th>Salary<tfoot><tr><th>Name<th>Position<th>Office<th>Age<th>Start date<th>Salary<tbody><tr><td>Tiger Nixon<td>System Architect<td>Edinburgh<td>61<td>2011/04/25<td>$320,800<tr><td>Garrett Winters<td>Accountant<td>Tokyo<td>63<td>2011/07/25<td>$170,750<tr><td>Ashton Cox<td>Junior Technical Author<td>San Francisco<td>66<td>2009/01/12<td>$86,000<tr><td>Cedric Kelly<td>Senior Javascript Developer<td>Edinburgh<td>22<td>2012/03/29<td>$433,060<tr><td>Airi Satou<td>Accountant<td>Tokyo<td>33<td>2008/11/28<td>$162,700<tr><td>Brielle Williamson<td>Integration Specialist<td>New York<td>61<td>2012/12/02<td>$372,000<tr><td>Herrod Chandler<td>Sales Assistant<td>San Francisco<td>59<td>2012/08/06<td>$137,500<tr><td>Rhona Davidson<td>Integration Specialist<td>Tokyo<td>55<td>2010/10/14<td>$327,900<tr><td>Colleen Hurst<td>Javascript Developer<td>San Francisco<td>39<td>2009/09/15<td>$205,500<tr><td>Sonya Frost<td>Software Engineer<td>Edinburgh<td>23<td>2008/12/13<td>$103,600<tr><td>Jena Gaines<td>Office Manager<td>London<td>30<td>2008/12/19<td>$90,560<tr><td>Quinn Flynn<td>Support Lead<td>Edinburgh<td>22<td>2013/03/03<td>$342,000<tr><td>Charde Marshall<td>Regional Director<td>San Francisco<td>36<td>2008/10/16<td>$470,600<tr><td>Haley Kennedy<td>Senior Marketing Designer<td>London<td>43<td>2012/12/18<td>$313,500<tr><td>Tatyana Fitzpatrick<td>Regional Director<td>London<td>19<td>2010/03/17<td>$385,750<tr><td>Michael Silva<td>Marketing Designer<td>London<td>66<td>2012/11/27<td>$198,500<tr><td>Paul Byrd<td>Chief Financial Officer (CFO)<td>New York<td>64<td>2010/06/09<td>$725,000<tr><td>Gloria Little<td>Systems Administrator<td>New York<td>59<td>2009/04/10<td>$237,500<tr><td>Bradley Greer<td>Software Engineer<td>London<td>41<td>2012/10/13<td>$132,000<tr><td>Dai Rios<td>Personnel Lead<td>Edinburgh<td>35<td>2012/09/26<td>$217,500<tr><td>Jenette Caldwell<td>Development Lead<td>New York<td>30<td>2011/09/03<td>$345,000<tr><td>Yuri Berry<td>Chief Marketing Officer (CMO)<td>New York<td>40<td>2009/06/25<td>$675,000<tr><td>Caesar Vance<td>Pre-Sales Support<td>New York<td>21<td>2011/12/12<td>$106,450<tr><td>Doris Wilder<td>Sales Assistant<td>Sidney<td>23<td>2010/09/20<td>$85,600<tr><td>Angelica Ramos<td>Chief Executive Officer (CEO)<td>London<td>47<td>2009/10/09<td>$1,200,000<tr><td>Gavin Joyce<td>Developer<td>Edinburgh<td>42<td>2010/12/22<td>$92,575<tr><td>Jennifer Chang<td>Regional Director<td>Singapore<td>28<td>2010/11/14<td>$357,650<tr><td>Brenden Wagner<td>Software Engineer<td>San Francisco<td>28<td>2011/06/07<td>$206,850<tr><td>Fiona Green<td>Chief Operating Officer (COO)<td>San Francisco<td>48<td>2010/03/11<td>$850,000<tr><td>Shou Itou<td>Regional Marketing<td>Tokyo<td>20<td>2011/08/14<td>$163,000<tr><td>Michelle House<td>Integration Specialist<td>Sidney<td>37<td>2011/06/02<td>$95,400<tr><td>Suki Burks<td>Developer<td>London<td>53<td>2009/10/22<td>$114,500<tr><td>Prescott Bartlett<td>Technical Author<td>London<td>27<td>2011/05/07<td>$145,000<tr><td>Gavin Cortez<td>Team Leader<td>San Francisco<td>22<td>2008/10/26<td>$235,500<tr><td>Martena Mccray<td>Post-Sales support<td>Edinburgh<td>46<td>2011/03/09<td>$324,050<tr><td>Unity Butler<td>Marketing Designer<td>San Francisco<td>47<td>2009/12/09<td>$85,675<tr><td>Howard Hatfield<td>Office Manager<td>San Francisco<td>51<td>2008/12/16<td>$164,500<tr><td>Hope Fuentes<td>Secretary<td>San Francisco<td>41<td>2010/02/12<td>$109,850<tr><td>Vivian Harrell<td>Financial Controller<td>San Francisco<td>62<td>2009/02/14<td>$452,500<tr><td>Timothy Mooney<td>Office Manager<td>London<td>37<td>2008/12/11<td>$136,200<tr><td>Jackson Bradshaw<td>Director<td>New York<td>65<td>2008/09/26<td>$645,750<tr><td>Olivia Liang<td>Support Engineer<td>Singapore<td>64<td>2011/02/03<td>$234,500<tr><td>Bruno Nash<td>Software Engineer<td>London<td>38<td>2011/05/03<td>$163,500<tr><td>Sakura Yamamoto<td>Support Engineer<td>Tokyo<td>37<td>2009/08/19<td>$139,575<tr><td>Thor Walton<td>Developer<td>New York<td>61<td>2013/08/11<td>$98,540<tr><td>Finn Camacho<td>Support Engineer<td>San Francisco<td>47<td>2009/07/07<td>$87,500<tr><td>Serge Baldwin<td>Data Coordinator<td>Singapore<td>64<td>2012/04/09<td>$138,575<tr><td>Zenaida Frank<td>Software Engineer<td>New York<td>63<td>2010/01/04<td>$125,250<tr><td>Zorita Serrano<td>Software Engineer<td>San Francisco<td>56<td>2012/06/01<td>$115,000<tr><td>Jennifer Acosta<td>Junior Javascript Developer<td>Edinburgh<td>43<td>2013/02/01<td>$75,650<tr><td>Cara Stevens<td>Sales Assistant<td>New York<td>46<td>2011/12/06<td>$145,600<tr><td>Hermione Butler<td>Regional Director<td>London<td>47<td>2011/03/21<td>$356,250<tr><td>Lael Greer<td>Systems Administrator<td>London<td>21<td>2009/02/27<td>$103,500<tr><td>Jonas Alexander<td>Developer<td>San Francisco<td>30<td>2010/07/14<td>$86,500<tr><td>Shad Decker<td>Regional Director<td>Edinburgh<td>51<td>2008/11/13<td>$183,000<tr><td>Michael Bruce<td>Javascript Developer<td>Singapore<td>29<td>2011/06/27<td>$183,000<tr><td>Donna Snider<td>Customer Support<td>New York<td>27<td>2011/01/25<td>$112,000</table></div><script src=https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js></script><script src=https://cdnjs.cloudflare.com/ajax/libs/datatables/1.10.20/js/jquery.dataTables.min.js></script><script src=https://cdnjs.cloudflare.com/ajax/libs/datatables/1.10.20/js/dataTables.bootstrap4.min.js></script>
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Bootstrap 3 with Bootstrap Table Example: Bootstrap Docs & Bootstrap Table Docs

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<link href=https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.4.1/css/bootstrap.min.css rel=stylesheet><link href=https://cdnjs.cloudflare.com/ajax/libs/bootstrap-table/1.16.0/bootstrap-table.min.css rel=stylesheet><table data-sort-name=stargazers_count data-sort-order=desc data-toggle=table data-url="https://api.github.com/users/wenzhixin/repos?type=owner&sort=full_name&direction=asc&per_page=100&page=1"><thead><tr><th data-field=name data-sortable=true>Name<th data-field=stargazers_count data-sortable=true>Stars<th data-field=forks_count data-sortable=true>Forks<th data-field=description data-sortable=true>Description</thead></table><script src=https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js></script><script src=https://cdnjs.cloudflare.com/ajax/libs/bootstrap-table/1.16.0/bootstrap-table.min.js></script>
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Bootstrap 3 with Bootstrap Sortable Example: Bootstrap Docs & Bootstrap Sortable Docs

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function randomDate(t,e){return new Date(t.getTime()+Math.random()*(e.getTime()-t.getTime()))}function randomName(){return["Jack","Peter","Frank","Steven"][Math.floor(4*Math.random())]+" "+["White","Jackson","Sinatra","Spielberg"][Math.floor(4*Math.random())]}function newTableRow(){var t=moment(randomDate(new Date(2e3,0,1),new Date)).format("D.M.YYYY"),e=Math.round(Math.random()*Math.random()*100*100)/100,a=Math.round(Math.random()*Math.random()*100*100)/100,r=Math.round(Math.random()*Math.random()*100*100)/100;return"<tr><td>"+randomName()+"</td><td>"+e+"</td><td>"+a+"</td><td>"+r+"</td><td>"+Math.round(100*(e+a+r))/100+"</td><td data-dateformat='D-M-YYYY'>"+t+"</td></tr>"}function customSort(){alert("Custom sort.")}!function(t,e){"use strict";"function"==typeof define&&define.amd?define("tinysort",function(){return e}):t.tinysort=e}(this,function(){"use strict";function t(t,e){for(var a,r=t.length,o=r;o--;)e(t[a=r-o-1],a)}function e(t,e,a){for(var o in 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t}M(a)&&(a=d.querySelectorAll(a)),0===a.length&&console.warn("No elements to sort");var x,N,F=d.createDocumentFragment(),D=[],Y=[],$=[],E=[],k=!0,A=a.length&&a[0].parentNode,T=A.rootNode!==document,R=a.length&&(s===r||!1!==s.useFlex)&&!T&&-1!==getComputedStyle(A,null).display.indexOf("flex");return function(){0===arguments.length?v({}):t(arguments,function(t){v(M(t)?{selector:t}:t)}),f=E.length}.apply(n,Array.prototype.slice.call(arguments,1)),t(a,function(t,e){N?N!==t.parentNode&&(k=!1):N=t.parentNode;var a=E[0],r=a.hasFilter,o=a.selector,n=!o||r&&t.matchesSelector(o)||o&&t.querySelector(o)?Y:$,s={elm:t,pos:e,posn:n.length};D.push(s),n.push(s)}),x=Y.slice(0),Y.sort(function(e,a){var n=0;for(0!==h&&(h=0);0===n&&f>h;){var s=E[h],d=s.ignoreDashes?c:l;if(t(u,function(t){var e=t.prepare;e&&e(s)}),s.sortFunction)n=s.sortFunction(e,a);else if("rand"==s.order)n=Math.random()<.5?1:-1;else{var p=o,m=C(e,s),v=C(a,s),w=""===m||m===r,S=""===v||v===r;if(m===v)n=0;else 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t.elm})},{plugin:a,defaults:m})}()),function(t,e){"function"==typeof define&&define.amd?define(["jquery","tinysort","moment"],e):e(t.jQuery,t.tinysort,t.moment||void 0)}(this,function(t,e,a){var r,o,n,s=t(document);function d(e){var s=void 0!==a;r=e.sign?e.sign:"arrow","default"==e.customSort&&(e.customSort=c),o=e.customSort||o||c,n=e.emptyEnd,t("table.sortable").each(function(){var r=t(this),o=!0===e.applyLast;r.find("span.sign").remove(),r.find("> thead [colspan]").each(function(){for(var e=parseFloat(t(this).attr("colspan")),a=1;a<e;a++)t(this).after('<th class="colspan-compensate">')}),r.find("> thead [rowspan]").each(function(){for(var e=t(this),a=parseFloat(e.attr("rowspan")),r=1;r<a;r++){var o=e.parent("tr"),n=o.next("tr"),s=o.children().index(e);n.children().eq(s).before('<th class="rowspan-compensate">')}}),r.find("> thead tr").each(function(e){t(this).find("th").each(function(a){var r=t(this);r.addClass("nosort").removeClass("up down"),r.attr("data-sortcolumn",a),r.attr("data-sortkey",a+"-"+e)})}),r.find("> thead .rowspan-compensate, .colspan-compensate").remove(),r.find("th").each(function(){var e=t(this);if(void 0!==e.attr("data-dateformat")&&s){var o=parseFloat(e.attr("data-sortcolumn"));r.find("td:nth-child("+(o+1)+")").each(function(){var r=t(this);r.attr("data-value",a(r.text(),e.attr("data-dateformat")).format("YYYY/MM/DD/HH/mm/ss"))})}else if(void 0!==e.attr("data-valueprovider")){o=parseFloat(e.attr("data-sortcolumn"));r.find("td:nth-child("+(o+1)+")").each(function(){var a=t(this);a.attr("data-value",new RegExp(e.attr("data-valueprovider")).exec(a.text())[0])})}}),r.find("td").each(function(){var e=t(this);void 0!==e.attr("data-dateformat")&&s?e.attr("data-value",a(e.text(),e.attr("data-dateformat")).format("YYYY/MM/DD/HH/mm/ss")):void 0!==e.attr("data-valueprovider")?e.attr("data-value",new RegExp(e.attr("data-valueprovider")).exec(e.text())[0]):void 0===e.attr("data-value")&&e.attr("data-value",e.text())});var n=l(r),d=n.bsSort;r.find('> thead th[data-defaultsort!="disabled"]').each(function(e){var a=t(this),r=a.closest("table.sortable");a.data("sortTable",r);var s=a.attr("data-sortkey"),i=o?n.lastSort:-1;d[s]=o?d[s]:a.attr("data-defaultsort"),void 0!==d[s]&&o===(s===i)&&(d[s]="asc"===d[s]?"desc":"asc",u(a,r))})})}function i(e){var a=t(e),r=a.data("sortTable")||a.closest("table.sortable");u(a,r)}function l(e){var a=e.data("bootstrap-sortable-context");return void 0===a&&(a={bsSort:[],lastSort:void 0},e.find('> thead th[data-defaultsort!="disabled"]').each(function(e){var r=t(this),o=r.attr("data-sortkey");a.bsSort[o]=r.attr("data-defaultsort"),void 0!==a.bsSort[o]&&(a.lastSort=o)}),e.data("bootstrap-sortable-context",a)),a}function c(t,a){e(t,a)}function u(e,a){a.trigger("before-sort");var s=parseFloat(e.attr("data-sortcolumn")),d=l(a),i=d.bsSort;if(e.attr("colspan")){var c=parseFloat(e.data("mainsort"))||0,f=parseFloat(e.data("sortkey").split("-").pop());if(a.find("> thead tr").length-1>f)return void u(a.find('[data-sortkey="'+(s+c)+"-"+(f+1)+'"]'),a);s+=c}var h=e.attr("data-defaultsign")||r;if(a.find("> thead th").each(function(){t(this).removeClass("up").removeClass("down").addClass("nosort")}),t.browser.mozilla){var p=a.find("> thead div.mozilla");void 0!==p&&(p.find(".sign").remove(),p.parent().html(p.html())),e.wrapInner('<div class="mozilla"></div>'),e.children().eq(0).append('<span class="sign '+h+'"></span>')}else a.find("> thead span.sign").remove(),e.append('<span class="sign '+h+'"></span>');var m=e.attr("data-sortkey"),v="desc"!==e.attr("data-firstsort")?"desc":"asc",b=i[m]||v;d.lastSort!==m&&void 0!==i[m]||(b="asc"===b?"desc":"asc"),i[m]=b,d.lastSort=m,"desc"===i[m]?(e.find("span.sign").addClass("up"),e.addClass("up").removeClass("down nosort")):e.addClass("down").removeClass("up nosort");var g=a.children("tbody").children("tr"),w=[];t(g.filter('[data-disablesort="true"]').get().reverse()).each(function(e,a){var r=t(a);w.push({index:g.index(r),row:r}),r.remove()});var S=g.not('[data-disablesort="true"]');if(0!=S.length){var y="asc"===i[m]&&n;o(S,{emptyEnd:y,selector:"td:nth-child("+(s+1)+")",order:i[m],data:"value"})}t(w.reverse()).each(function(t,e){0===e.index?a.children("tbody").prepend(e.row):a.children("tbody").children("tr").eq(e.index-1).after(e.row)}),a.find("> tbody > tr > td.sorted,> thead th.sorted").removeClass("sorted"),S.find("td:eq("+s+")").addClass("sorted"),e.addClass("sorted"),a.trigger("sorted")}if(t.bootstrapSortable=function(t){null==t?d({}):t.constructor===Boolean?d({applyLast:t}):void 0!==t.sortingHeader?i(t.sortingHeader):d(t)},s.on("click",'table.sortable>thead th[data-defaultsort!="disabled"]',function(t){i(this)}),!t.browser){t.browser={chrome:!1,mozilla:!1,opera:!1,msie:!1,safari:!1};var f=navigator.userAgent;t.each(t.browser,function(e){t.browser[e]=!!new RegExp(e,"i").test(f),t.browser.mozilla&&"mozilla"===e&&(t.browser.mozilla=!!new RegExp("firefox","i").test(f)),t.browser.chrome&&"safari"===e&&(t.browser.safari=!1)})}t(t.bootstrapSortable)}),function(){var t=$("table");t.append(newTableRow()),t.append(newTableRow()),$("button.add-row").on("click",function(){var e=$(this);t.append(newTableRow()),e.data("sort")?$.bootstrapSortable(!0):$.bootstrapSortable(!1)}),$("button.change-sort").on("click",function(){$(this).data("custom")?$.bootstrapSortable(!0,void 0,customSort):$.bootstrapSortable(!0,void 0,"default")}),t.on("sorted",function(){alert("Table was sorted.")}),$("#event").on("change",function(){$(this).is(":checked")?t.on("sorted",function(){alert("Table was sorted.")}):t.off("sorted")}),$("input[name=sign]:radio").change(function(){$.bootstrapSortable(!0,$(this).val())})}();
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table.sortable span.sign { display: block; position: absolute; top: 50%; right: 5px; font-size: 12px; margin-top: -10px; color: #bfbfc1; } table.sortable th:after { display: block; position: absolute; top: 50%; right: 5px; font-size: 12px; margin-top: -10px; color: #bfbfc1; } table.sortable th.arrow:after { content: ''; } table.sortable span.arrow, span.reversed, th.arrow.down:after, th.reversedarrow.down:after, th.arrow.up:after, th.reversedarrow.up:after { border-style: solid; border-width: 5px; font-size: 0; border-color: #ccc transparent transparent transparent; line-height: 0; height: 0; width: 0; margin-top: -2px; } table.sortable span.arrow.up, th.arrow.up:after { border-color: transparent transparent #ccc transparent; margin-top: -7px; } table.sortable span.reversed, th.reversedarrow.down:after { border-color: transparent transparent #ccc transparent; margin-top: -7px; } table.sortable span.reversed.up, th.reversedarrow.up:after { border-color: #ccc transparent transparent transparent; margin-top: -2px; } table.sortable span.az:before, th.az.down:after { content: "a .. z"; } table.sortable span.az.up:before, th.az.up:after { content: "z .. a"; } table.sortable th.az.nosort:after, th.AZ.nosort:after, th._19.nosort:after, th.month.nosort:after { content: ".."; } table.sortable span.AZ:before, th.AZ.down:after { content: "A .. Z"; } table.sortable span.AZ.up:before, th.AZ.up:after { content: "Z .. A"; } table.sortable span._19:before, th._19.down:after { content: "1 .. 9"; } table.sortable span._19.up:before, th._19.up:after { content: "9 .. 1"; } table.sortable span.month:before, th.month.down:after { content: "jan .. dec"; } table.sortable span.month.up:before, th.month.up:after { content: "dec .. jan"; } table.sortable thead th:not([data-defaultsort=disabled]) { cursor: pointer; position: relative; top: 0; left: 0; } table.sortable thead th:hover:not([data-defaultsort=disabled]) { background: #efefef; } table.sortable thead th div.mozilla { position: relative; }
_x000D_
<link href=https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.13.1/css/all.min.css rel=stylesheet><link href=https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css rel=stylesheet><div class=container><div class=hero-unit><h1>Bootstrap Sortable</h1></div><table class="sortable table table-bordered table-striped"><thead><tr><th style=width:20%;vertical-align:middle data-defaultsign=nospan class=az data-defaultsort=asc rowspan=2><i class="fa fa-fw fa-map-marker"></i>Name<th style=text-align:center colspan=4 data-mainsort=3>Results<th data-defaultsort=disabled><tr><th style=width:20% colspan=2 data-mainsort=1 data-firstsort=desc>Round 1<th style=width:20%>Round 2<th style=width:20%>Total<t
                  

RESTful Authentication

To answer this question from my understanding...

An authentication system that uses REST so that you do not need to actually track or manage the users in your system. This is done by using the HTTP methods POST, GET, PUT, DELETE. We take these 4 methods and think of them in terms of database interaction as CREATE, READ, UPDATE, DELETE (but on the web we use POST and GET because that is what anchor tags support currently). So treating POST and GET as our CREATE/READ/UPDATE/DELETE (CRUD) then we can design routes in our web application that will be able to deduce what action of CRUD we are achieving.

For example, in a Ruby on Rails application we can build our web app such that if a user who is logged in visits http://store.com/account/logout then the GET of that page can viewed as the user attempting to logout. In our rails controller we would build an action in that logs the user out and sends them back to the home page.

A GET on the login page would yield a form. a POST on the login page would be viewed as a login attempt and take the POST data and use it to login.

To me, it is a practice of using HTTP methods mapped to their database meaning and then building an authentication system with that in mind you do not need to pass around any session id's or track sessions.

I'm still learning -- if you find anything I have said to be wrong please correct me, and if you learn more post it back here. Thanks.

How to remove a package in sublime text 2

There are several answers, First IF you are using Package Control simply use Package Control's Remove Package command...

Ctrl+Shift+P

Package Control: Remove Package

If you installed the package manually, and are on a Windows machine...have no fear; Just modify the files manually.

First navigate to

C:\users\[Name]\AppData\Roaming\Sublime Text [version]\

There will be 4 directories:

  1. Installed Packages (Holds the Package Control config file, ignore)
  2. Packages (Holds Package source)
  3. Pristine Packages (Holds the versioning info, ignore)
  4. Settings (Sublime Setting Info, ignore)

First open ..\Packages folder and locate the folder named the same as your package; Delete it.

Secondly, open Sublime and navigate to the Preferences > Package Settings > Package Control > Settings-user

Third, locate the line where the package name you want to "uninstall"

{
    "installed_packages":
    [
        "Alignment",
        "All Autocomplete",
        "AngularJS",
        "AutoFileName",
        "BracketHighlighter",
        "Browser Support",
        "Case Conversion",
        "ColorPicker",
        "Emmet",
        "FileDiffs",
        "Format SQL",
        "Git",
        "Github Tools",
        "HTML-CSS-JS Prettify",
        "HTML5",
        "HTMLBeautify",
        "jQuery",
        "JsFormat",
        "JSHint",
        "JsMinifier",
        "LiveReload",
        "LoremIpsum",
        "LoremPixel",
        "Oracle PL SQL",
        "Package Control",
        "Placehold.it Image Tag Generator",
        "Placeholders",
        "Prefixr",
        "Search Stack Overflow",
        "SublimeAStyleFormatter",
        "SublimeCodeIntel",
        "Tag",
        "Theme - Centurion",
        "TortoiseSVN",
        "Zen Tabs"
    ]
}

NOTE Say the package you are removing is "Zen Tabs", you MUST also remove the , after "TortoiseSVN" or it will error.

Thus concludes the easiest way to remove or Install a Sublime Text Package.

Get css top value as number not as string?

A jQuery plugin based on M4N's answer

jQuery.fn.cssNumber = function(prop){
    var v = parseInt(this.css(prop),10);
    return isNaN(v) ? 0 : v;
};

So then you just use this method to get number values

$("#logo").cssNumber("top")

Linux: copy and create destination dir if it does not exist

cp has multiple usages:

$ cp --help
Usage: cp [OPTION]... [-T] SOURCE DEST
  or:  cp [OPTION]... SOURCE... DIRECTORY
  or:  cp [OPTION]... -t DIRECTORY SOURCE...
Copy SOURCE to DEST, or multiple SOURCE(s) to DIRECTORY.

@AndyRoss's answer works for the

cp SOURCE DEST

style of cp, but does the wrong thing if you use the

cp SOURCE... DIRECTORY/

style of cp.

I think that "DEST" is ambiguous without a trailing slash in this usage (i.e. where the target directory doesn't yet exist), which is perhaps why cp has never added an option for this.

So here's my version of this function which enforces a trailing slash on the dest dir:

cp-p() {
  last=${@: -1}

  if [[ $# -ge 2 && "$last" == */ ]] ; then
    # cp SOURCE... DEST/
    mkdir -p "$last" && cp "$@"
  else
    echo "cp-p: (copy, creating parent dirs)"
    echo "cp-p: Usage: cp-p SOURCE... DEST/"
  fi
}

What does getActivity() mean?

getActivity() is used for fragment. For activity, wherever you can use this, you can replace the this in fragment in similar cases with getActivity().

How to use source: function()... and AJAX in JQuery UI autocomplete

Inside your AJAX callback you need to call the response function; passing the array that contains items to display.

jQuery("input.suggest-user").autocomplete({
    source: function (request, response) {
        jQuery.get("usernames.action", {
            query: request.term
        }, function (data) {
            // assuming data is a JavaScript array such as
            // ["[email protected]", "[email protected]","[email protected]"]
            // and not a string
            response(data);
        });
    },
    minLength: 3
});

If the response JSON does not match the formats accepted by jQuery UI autocomplete then you must transform the result inside the AJAX callback before passing it to the response callback. See this question and the accepted answer.

Compare two files in Visual Studio

VS2019->View->Other Windows->Command Window (CTRL+ALT+A)

Tools.DiffFiles File1 File2

Get the selected option id with jQuery

Th easiest way to this is var id = $(this).val(); from inside an event like on change.

How to initialize a two-dimensional array in Python?

Initializing a 2D matrix of size m X n with 0

m,n = map(int,input().split())
l = [[0 for i in range(m)] for j in range(n)]
print(l)

Correctly ignore all files recursively under a specific folder except for a specific file type

Either I'm doing it wrongly, or the accepted answer does not work anymore with the current git.

I have actually found the proper solution and posted it under almost the same question here. For more details head there.

Solution:

# Ignore everything inside Resources/ directory
/Resources/**
# Except for subdirectories(won't be committed anyway if there is no committed file inside)
!/Resources/**/
# And except for *.foo files
!*.foo

How to easily consume a web service from PHP

Well, those features are specific to a tool that you are using for development in those languages.

You wouldn't have those tools if (for example) you were using notepad to write code. So, maybe you should ask the question for the tool you are using.

For PHP: http://webservices.xml.com/pub/a/ws/2004/03/24/phpws.html

Running Internet Explorer 6, Internet Explorer 7, and Internet Explorer 8 on the same machine

Backing up the other users, you will need to run Virtual PC instances on your Windows box. If you try to do a multi install of Internet Explorer, you will break conditional comments on pages, which will make testing difficult anyway (For example, With Internet Explorer 5, 6 and 7. On a Windows box, the IF Internet Explorer statements will resolve to Internet Explorer 7 even in Internet Explorer 5, which means even more weird bugs.

More information and a link to download and run a Internet Explorer 6 Virtual Image: http://blogs.msdn.com/ie/archive/2007/04/17/ie7-virtual-pc-image-and-ie6-virtual-pc-image-refresh.aspx

If you have Virtual PC already, here is the image: http://www.microsoft.com/Downloads/details.aspx?FamilyID=21eabb90-958f-4b64-b5f1-73d0a413c8ef&displaylang=en

New line in Sql Query

Pinal Dave explains this well in his blog.

http://blog.sqlauthority.com/2009/07/01/sql-server-difference-between-line-feed-n-and-carriage-return-r-t-sql-new-line-char/

DECLARE @NewLineChar AS CHAR(2) = CHAR(13) + CHAR(10)
PRINT ('SELECT FirstLine AS FL ' + @NewLineChar + 'SELECT SecondLine AS SL')

`&mdash;` or `&#8212;` is there any difference in HTML output?

They are exactly the same character. See: http://en.wikipedia.org/wiki/Dash

Barring browser bugs they will display the same in all cases, so the only difference would be concerning code readability, which would point to &mdash;.

Or, if you are using UTF-8 as a charset in your HTML document, you could enter the character directly. That would also display exactly the same.

Python urllib2: Receive JSON response from url

Python 3 standard library one-liner:

load(urlopen(url))

# imports (place these above the code before running it)
from json import load
from urllib.request import urlopen
url = 'https://jsonplaceholder.typicode.com/todos/1'

XMLHttpRequest cannot load file. Cross origin requests are only supported for HTTP

If you use the WebStorm Javascript IDE, you can just open your project from WebStorm in your browser. WebStorm will automatically start a server and you won't get any of these errors anymore, because you are now accessing the files with the allowed/supported protocols (HTTP).

How do I check in SQLite whether a table exists?

The most reliable way I have found in C# right now, using the latest sqlite-net-pcl nuget package (1.5.231) which is using SQLite 3, is as follows:

var result = database.GetTableInfo(tableName);
if ((result == null) || (result.Count == 0))
{
    database.CreateTable<T>(CreateFlags.AllImplicit);
}

Non greedy (reluctant) regex matching in sed?

Have not yet seen this answer, so here's how you can do this with vi or vim:

vi -c '%s/\(http:\/\/.\{-}\/\).*/\1/ge | wq' file &>/dev/null

This runs the vi :%s substitution globally (the trailing g), refrains from raising an error if the pattern is not found (e), then saves the resulting changes to disk and quits. The &>/dev/null prevents the GUI from briefly flashing on screen, which can be annoying.

I like using vi sometimes for super complicated regexes, because (1) perl is dead dying, (2) vim has a very advanced regex engine, and (3) I'm already intimately familiar with vi regexes in my day-to-day usage editing documents.

Is there a command to list all Unix group names?

If you want all groups known to the system, I would recommend using getent group instead of parsing /etc/group:

getent group

The reason is that on networked systems, groups may not only read from /etc/group file, but also obtained through LDAP or Yellow Pages (the list of known groups comes from the local group file plus groups received via LDAP or YP in these cases).

If you want just the group names you can use:

getent group | cut -d: -f1

How to upload file to server with HTTP POST multipart/form-data?

For people searching for 403 forbidden issue while trying to upload in multipart form the below might help as there is a case depending on the server configuration that you will get MULTIPART_STRICT_ERROR "!@eq 0" due to incorrect MultipartFormDataContent headers. Please note that both imagetag/filename variables include quotations (\") eg filename="\"myfile.png\"" .

    MultipartFormDataContent form = new MultipartFormDataContent();
    ByteArrayContent imageContent = new ByteArrayContent(fileBytes, 0, fileBytes.Length);
    imageContent.Headers.TryAddWithoutValidation("Content-Disposition", "form-data; name="+imagetag+"; filename="+filename);
    imageContent.Headers.TryAddWithoutValidation("Content-Type", "image / png");
    form.Add(imageContent, imagetag, filename);

Access denied for user 'test'@'localhost' (using password: YES) except root user

For annoying searching getting here after searching for this error message:

Access denied for user 'someuser@somewhere' (using password: YES)

The issue for me was not enclosing the password in quotes. eg. I needed to use -p'password' instead of -ppassword

What exactly does Double mean in java?

In a comment on @paxdiablo's answer, you asked:

"So basically, is it better to use Double than Float?"

That is a complicated question. I will deal with it in two parts


Deciding between double versus float

On the one hand, a double occupies 8 bytes versus 4 bytes for a float. If you have many of them, this may be significant, though it may also have no impact. (Consider the case where the values are in fields or local variables on a 64bit machine, and the JVM aligns them on 64 bit boundaries.) Additionally, floating point arithmetic with double values is typically slower than with float values ... though once again this is hardware dependent.

On the other hand, a double can represent larger (and smaller) numbers than a float and can represent them with more than twice the precision. For the details, refer to Wikipedia.

The tricky question is knowing whether you actually need the extra range and precision of a double. In some cases it is obvious that you need it. In others it is not so obvious. For instance if you are doing calculations such as inverting a matrix or calculating a standard deviation, the extra precision may be critical. On the other hand, in some cases not even double is going to give you enough precision. (And beware of the trap of expecting float and double to give you an exact representation. They won't and they can't!)

There is a branch of mathematics called Numerical Analysis that deals with the effects of rounding error, etc in practical numerical calculations. It used to be a standard part of computer science courses ... back in the 1970's.


Deciding between Double versus Float

For the Double versus Float case, the issues of precision and range are the same as for double versus float, but the relative performance measures will be slightly different.

  • A Double (on a 32 bit machine) typically takes 16 bytes + 4 bytes for the reference, compared with 12 + 4 bytes for a Float. Compare this to 8 bytes versus 4 bytes for the double versus float case. So the ratio is 5 to 4 versus 2 to 1.

  • Arithmetic involving Double and Float typically involves dereferencing the pointer and creating a new object to hold the result (depending on the circumstances). These extra overheads also affect the ratios in favor of the Double case.


Correctness

Having said all that, the most important thing is correctness, and this typically means getting the most accurate answer. And even if accuracy is not critical, it is usually not wrong to be "too accurate". So, the simple "rule of thumb" is to use double in preference to float, UNLESS there is an overriding performance requirement, AND you have solid evidence that using float will make a difference with respect to that requirement.

ArrayList vs List<> in C#

I think, the differences between ArrayList and List<T> are:

  1. List<T>, where T is value-type is faster than ArrayList. This is because List<T> avoids boxing/unboxing (where T is value-type).
  2. Many sources say - usually ArrayList used just for backward compatibility. (is not a real difference, but i think it is important note).
  3. Reflection is easier with nongeneric ArrayList then List<T>
  4. ArrayList has IsSynchronized property. So, It is easy to create and use syncronised ArrayList. I didin't found IsSynchronized property for List<T>. Also Keep in mind this type of synchronization is relatively inefficient, msdn):

    var arraylist = new ArrayList();
    var arrayListSyncronized = ArrayList.Synchronized(arraylist
    Console.WriteLine($"syncronized {arraylist.IsSynchronized}");
    Console.WriteLine($"syncronized {arrayListSyncronized.IsSynchronized}");
    
    var list = new List<object>();
    var listSyncronized = ArrayList.Synchronized(list);
    Console.WriteLine($"syncronized {list.IsSynchronized}");//error, no such prop
    Console.WriteLine($"syncronized {list.IsSynchronized}");//error, no such prop
    
  5. ArrayList has ArrayList.SyncRoot property which can be used for syncronisation (msdn). List<T> hasn't SyncRoot property, so in the following construction you need to use some object if you use List<T>:

    ArrayList myCollection = new ArrayList();
    lock(myCollection.SyncRoot) //  ofcourse you can use another object for this goal
    {
        foreach (object item in myCollection)
        {
            // ...
        }
    }
    

Javascript Object push() function

Javascript programming language supports functional programming paradigm so you can do easily with these codes.

var data = [
    {"Id": "1", "Status": "Valid"},
    {"Id": "2", "Status": "Invalid"}
];
var isValid = function(data){
    return data.Status === "Valid";
};
var valids = data.filter(isValid);

Jquery: Find Text and replace

Warning string.replace('string','new string') not replaced all character. You have to use regax replace.

For exp: I have a sting old string1, old string2, old string3 and want to replace old to new

Then i used.

    var test = 'old string1, old string2, old string3';

   //***** Wrong method **********
    test = test.replace('old', 'new'); // This  will replaced only first match not all
    Result: new string1, old string2, old string3

  //***** Right method **********
    test = test.replace(/([old])+/g, 'new'); // This  will replaced all match 
    Result: new string1, new string2, new string3

Apache HttpClient Interim Error: NoHttpResponseException

Most likely persistent connections that are kept alive by the connection manager become stale. That is, the target server shuts down the connection on its end without HttpClient being able to react to that event, while the connection is being idle, thus rendering the connection half-closed or 'stale'. Usually this is not a problem. HttpClient employs several techniques to verify connection validity upon its lease from the pool. Even if the stale connection check is disabled and a stale connection is used to transmit a request message the request execution usually fails in the write operation with SocketException and gets automatically retried. However under some circumstances the write operation can terminate without an exception and the subsequent read operation returns -1 (end of stream). In this case HttpClient has no other choice but to assume the request succeeded but the server failed to respond most likely due to an unexpected error on the server side.

The simplest way to remedy the situation is to evict expired connections and connections that have been idle longer than, say, 1 minute from the pool after a period of inactivity. For details please see this section of the HttpClient tutorial.

Get the week start date and week end date from week number

The most voted answer works fine except for the 1st week and last week of a year. For example, if the value of WeddingDate is '2016-01-01', the result will be 2015-12-27 and 2016-01-02, but the right answer is 2016-01-01 and 2016-01-02.

Try this:

Select 
  Sum(NumberOfBrides) As [Wedding Count], 
  DATEPART( wk, WeddingDate) as [Week Number],
  DATEPART( year, WeddingDate) as [Year],
  MAX(CASE WHEN DATEPART(WEEK, WeddingDate) = 1 THEN CAST(DATEADD(YEAR, DATEDIFF(YEAR, 0, WeddingDate), 0) AS date) ELSE DATEADD(DAY, 7 * DATEPART(WEEK, WeddingDate), DATEADD(DAY, -(DATEPART(WEEKDAY, DATEADD(YEAR, DATEDIFF(YEAR, 0, WeddingDate), 0)) + 6), DATEADD(YEAR, DATEDIFF(YEAR, 0, WeddingDate), 0))) END) as WeekStart,
  MAX(CASE WHEN DATEPART(WEEK, WeddingDate) = DATEPART(WEEK, DATEADD(DAY, -1, DATEADD(YEAR, DATEDIFF(YEAR, 0, WeddingDate) + 1, 0))) THEN DATEADD(DAY, -1, DATEADD(YEAR, DATEDIFF(YEAR, 0, WeddingDate) + 1, 0)) ELSE DATEADD(DAY, 7 * DATEPART(WEEK, WeddingDate) + 6, DATEADD(DAY, -(DATEPART(WEEKDAY, DATEADD(YEAR, DATEDIFF(YEAR, 0, WeddingDate), 0)) + 6), DATEADD(YEAR, DATEDIFF(YEAR, 0, WeddingDate), 0))) END) as WeekEnd
FROM  MemberWeddingDates
Group By DATEPART( year, WeddingDate), DATEPART( wk, WeddingDate)
Order By Sum(NumberOfBrides) Desc;

The result looks like: enter image description here

It works for all weeks, 1st or others.

How to remove all duplicate items from a list

This should do it for you:

new_list = list(set(old_list))

set will automatically remove duplicates. list will cast it back to a list.

Copy data from one existing row to another existing row in SQL?

Try this:

UPDATE barang
SET ID FROM(SELECT tblkatalog.tblkatalog_id FROM tblkatalog 
WHERE tblkatalog.tblkatalog_nomor = barang.NO_CAT) WHERE barang.NO_CAT <>'';

Ruby on Rails: how to render a string as HTML?

Use raw:

<%=raw @str >

But as @jmort253 correctly says, consider where the HTML really belongs.

How to change facet labels?

I have another way to achieve the same goal without changing the underlying data:

ggplot(transform(survey, survey = factor(survey,
        labels = c("Hosp 1", "Hosp 2", "Hosp 3", "Hosp 4"))), aes(x = age)) +
  stat_bin(aes(n = nrow(h3),y=..count../n), binwidth = 10) +
  scale_y_continuous(formatter = "percent", breaks = c(0, 0.1, 0.2)) +
  facet_grid(hospital ~ .) +
  opts(panel.background = theme_blank())

What I did above is changing the labels of the factor in the original data frame, and that is the only difference compared with your original code.

What are the options for storing hierarchical data in a relational database?

This is really a square peg, round hole question.

If relational databases and SQL are the only hammer you have or are willing to use, then the answers that have been posted thus far are adequate. However, why not use a tool designed to handle hierarchical data? Graph database are ideal for complex hierarchical data.

The inefficiencies of the relational model along with the complexities of any code/query solution to map a graph/hierarchical model onto a relational model is just not worth the effort when compared to the ease with which a graph database solution can solve the same problem.

Consider a Bill of Materials as a common hierarchical data structure.

class Component extends Vertex {
    long assetId;
    long partNumber;
    long material;
    long amount;
};

class PartOf extends Edge {
};

class AdjacentTo extends Edge {
};

Shortest path between two sub-assemblies: Simple graph traversal algorithm. Acceptable paths can be qualified based on criteria.

Similarity: What is the degree of similarity between two assemblies? Perform a traversal on both sub-trees computing the intersection and union of the two sub-trees. The percent similar is the intersection divided by the union.

Transitive Closure: Walk the sub-tree and sum up the field(s) of interest, e.g. "How much aluminum is in a sub-assembly?"

Yes, you can solve the problem with SQL and a relational database. However, there are much better approaches if you are willing to use the right tool for the job.

How can I test a PDF document if it is PDF/A compliant?

If you download the latest version of Adobe Acrobat Reader, it will tell you if your pdf is PDF/A compliant. Just open the PDF file and a big blue marking should appear.

OpenOffice supports PDF/A. For some reason "PDF/A-1" is called

"SelectPdfVersion"
internally in OpenOffice. Just add 1 to that value and your output should be PDF/A.

The different values can be

0 = PDFXNONE
1 = PDFX1A2001
2 = PDFX32002
3 = PDFA1A
4 = PDFA1B

You set

FilterData
to be a
HashMap('SelectPdfVersion',1) //1 for PDFX1A2001

Rounding a number to the nearest 5 or 10 or X

Simply ROUND(x/5)*5 should do the job.

How to check if object property exists with a variable holding the property name?

Thank you for everyone's assistance and pushing to get rid of the eval statement. Variables needed to be in brackets, not dot notation. This works and is clean, proper code.

Each of these are variables: appChoice, underI, underObstr.

if(typeof tData.tonicdata[appChoice][underI][underObstr] !== "undefined"){
    //enter code here
}

Convert hours:minutes:seconds into total minutes in excel

Just use the formula

120 = (HOUR(A8)*3600+MINUTE(A8)*60+SECOND(A8))/60

AWS : The config profile (MyName) could not be found

In my case, I was using the Docker method for the AWS CLI tool, and I hadn't read the instructions far enough to realize that I had to make my credentials directory visible to the docker container. https://docs.aws.amazon.com/cli/latest/userguide/install-cliv2-docker.html

Instead of

docker run --rm -it amazon/aws-cli:latest command args...

I needed to do:

docker run --rm -it -v ~/.aws:/root/.aws amazon/aws-cli:latest command args...

how to insert date and time in oracle?

You are doing everything right by using a to_date function and specifying the time. The time is there in the database. The trouble is just that when you select a column of DATE datatype from the database, the default format mask doesn't show the time. If you issue a

alter session set nls_date_format = 'dd/MON/yyyy hh24:mi:ss'

or something similar including a time component, you will see that the time successfully made it into the database.

Spring Boot default H2 jdbc connection (and H2 console)

I had made a very stupid mistake when I had this same problem. I had added H2 DB for running unit test cases and hence I had set the scope to test in pom.xml. While running the application using mvn spring:run I removed the scope and it works fine now.

Inline for loop

you can use enumerate keeping the ind/index of the elements is in vm, if you make vm a set you will also have 0(1) lookups:

vm = {-1, -1, -1, -1}

print([ind if q in vm else 9999 for ind,ele in enumerate(vm) ])

How to set response header in JAX-RS so that user sees download popup for Excel?

You don't need HttpServletResponse to set a header on the response. You can do it using javax.ws.rs.core.Response. Just make your method to return Response instead of entity:

return Response.ok(entity).header("Content-Disposition", "attachment; filename=\"" + fileName + "\"").build()

If you still want to use HttpServletResponse you can get it either injected to one of the class fields, or using property, or to method parameter:

@Path("/resource")
class MyResource {

  // one way to get HttpServletResponse
  @Context
  private HttpServletResponse anotherServletResponse;

  // another way
  Response myMethod(@Context HttpServletResponse servletResponse) {
      // ... code
  }
}

How do I change the figure size with subplots?

If you already have the figure object use:

f.set_figheight(15)
f.set_figwidth(15)

But if you use the .subplots() command (as in the examples you're showing) to create a new figure you can also use:

f, axs = plt.subplots(2,2,figsize=(15,15))

Plot different DataFrames in the same figure

Just to enhance @adivis12 answer, you don't need to do the if statement. Put it like this:

fig, ax = plt.subplots()
for BAR in dict_of_dfs.keys():
    dict_of_dfs[BAR].plot(ax=ax)

Windows Scheduled task succeeds but returns result 0x1

It seems many users are having issues with this. Here are some fixes:

  • Right click on your task > "Properties" > "Actions" > "Edit" | Put ONLY the file name under 'Program/Script', no quotes and ONLY the directory under 'Start in' as described, again no quotes.

  • Right click on your task > "Properties" > "General" | Test with any/all of the following:

    1. "Run with highest privileges" (test both options)
    2. "Run wheter user is logged on or not" (test both options)
    3. Check that "Configure for" is set to your machine's OS version
    4. Make sure the user account running the program has the right permissions

adding x and y axis labels in ggplot2

[Note: edited to modernize ggplot syntax]

Your example is not reproducible since there is no ex1221new (there is an ex1221 in Sleuth2, so I guess that is what you meant). Also, you don't need (and shouldn't) pull columns out to send to ggplot. One advantage is that ggplot works with data.frames directly.

You can set the labels with xlab() and ylab(), or make it part of the scale_*.* call.

library("Sleuth2")
library("ggplot2")
ggplot(ex1221, aes(Discharge, Area)) +
  geom_point(aes(size=NO3)) + 
  scale_size_area() + 
  xlab("My x label") +
  ylab("My y label") +
  ggtitle("Weighted Scatterplot of Watershed Area vs. Discharge and Nitrogen Levels (PPM)")

enter image description here

ggplot(ex1221, aes(Discharge, Area)) +
  geom_point(aes(size=NO3)) + 
  scale_size_area("Nitrogen") + 
  scale_x_continuous("My x label") +
  scale_y_continuous("My y label") +
  ggtitle("Weighted Scatterplot of Watershed Area vs. Discharge and Nitrogen Levels (PPM)")

enter image description here

An alternate way to specify just labels (handy if you are not changing any other aspects of the scales) is using the labs function

ggplot(ex1221, aes(Discharge, Area)) +
  geom_point(aes(size=NO3)) + 
  scale_size_area() + 
  labs(size= "Nitrogen",
       x = "My x label",
       y = "My y label",
       title = "Weighted Scatterplot of Watershed Area vs. Discharge and Nitrogen Levels (PPM)")

which gives an identical figure to the one above.

How to remove \xa0 from string in Python?

I ran into this same problem pulling some data from a sqlite3 database with python. The above answers didn't work for me (not sure why), but this did: line = line.decode('ascii', 'ignore') However, my goal was deleting the \xa0s, rather than replacing them with spaces.

I got this from this super-helpful unicode tutorial by Ned Batchelder.

How to add data into ManyToMany field?

In case someone else ends up here struggling to customize admin form Many2Many saving behaviour, you can't call self.instance.my_m2m.add(obj) in your ModelForm.save override, as ModelForm.save later populates your m2m from self.cleaned_data['my_m2m'] which overwrites your changes. Instead call:

my_m2ms = list(self.cleaned_data['my_m2ms'])
my_m2ms.extend(my_custom_new_m2ms)
self.cleaned_data['my_m2ms'] = my_m2ms

(It is fine to convert the incoming QuerySet to a list - the ManyToManyField does that anyway.)

How to do associative array/hashing in JavaScript

https://gist.github.com/alexhawkins/f6329420f40e5cafa0a4

var HashTable = function() {
  this._storage = [];
  this._count = 0;
  this._limit = 8;
}


HashTable.prototype.insert = function(key, value) {

  // Create an index for our storage location by passing
  // it through our hashing function
  var index = this.hashFunc(key, this._limit);

  // Retrieve the bucket at this particular index in
  // our storage, if one exists
  //[[ [k,v], [k,v], [k,v] ] , [ [k,v], [k,v] ]  [ [k,v] ] ]
  var bucket = this._storage[index]

  // Does a bucket exist or do we get undefined
  // when trying to retrieve said index?
  if (!bucket) {
    // Create the bucket
    var bucket = [];
    // Insert the bucket into our hashTable
    this._storage[index] = bucket;
  }

  var override = false;

  // Now iterate through our bucket to see if there are any conflicting
  // key value pairs within our bucket. If there are any, override them.
  for (var i = 0; i < bucket.length; i++) {
    var tuple = bucket[i];
    if (tuple[0] === key) {

      // Override value stored at this key
      tuple[1] = value;
      override = true;
    }
  }

  if (!override) {
    // Create a new tuple in our bucket.
    // Note that this could either be the new empty bucket we created above
    // or a bucket with other tupules with keys that are different than
    // the key of the tuple we are inserting. These tupules are in the same
    // bucket because their keys all equate to the same numeric index when
    // passing through our hash function.
    bucket.push([key, value]);
    this._count++

    // Now that we've added our new key/val pair to our storage
    // let's check to see if we need to resize our storage
    if (this._count > this._limit * 0.75) {
      this.resize(this._limit * 2);
    }
  }
  return this;
};


HashTable.prototype.remove = function(key) {
  var index = this.hashFunc(key, this._limit);
  var bucket = this._storage[index];
  if (!bucket) {
    return null;
  }

  // Iterate over the bucket
  for (var i = 0; i < bucket.length; i++) {
    var tuple = bucket[i];

    // Check to see if key is inside bucket
    if (tuple[0] === key) {

      // If it is, get rid of this tuple
      bucket.splice(i, 1);
      this._count--;
      if (this._count < this._limit * 0.25) {
        this._resize(this._limit / 2);
      }
      return tuple[1];
    }
  }
};


HashTable.prototype.retrieve = function(key) {
  var index = this.hashFunc(key, this._limit);
  var bucket = this._storage[index];

  if (!bucket) {
    return null;
  }

  for (var i = 0; i < bucket.length; i++) {
    var tuple = bucket[i];
    if (tuple[0] === key) {
      return tuple[1];
    }
  }

  return null;
};


HashTable.prototype.hashFunc = function(str, max) {
  var hash = 0;
  for (var i = 0; i < str.length; i++) {
    var letter = str[i];
    hash = (hash << 5) + letter.charCodeAt(0);
    hash = (hash & hash) % max;
  }
  return hash;
};


HashTable.prototype.resize = function(newLimit) {
  var oldStorage = this._storage;

  this._limit = newLimit;
  this._count = 0;
  this._storage = [];

  oldStorage.forEach(function(bucket) {
    if (!bucket) {
      return;
    }
    for (var i = 0; i < bucket.length; i++) {
      var tuple = bucket[i];
      this.insert(tuple[0], tuple[1]);
    }
  }.bind(this));
};


HashTable.prototype.retrieveAll = function() {
  console.log(this._storage);
  //console.log(this._limit);
};

/******************************TESTS*******************************/

var hashT = new HashTable();

hashT.insert('Alex Hawkins', '510-599-1930');
//hashT.retrieve();
//[ , , , [ [ 'Alex Hawkins', '510-599-1930' ] ] ]
hashT.insert('Boo Radley', '520-589-1970');
//hashT.retrieve();
//[ , [ [ 'Boo Radley', '520-589-1970' ] ], , [ [ 'Alex Hawkins', '510-599-1930' ] ] ]
hashT.insert('Vance Carter', '120-589-1970').insert('Rick Mires', '520-589-1970').insert('Tom Bradey', '520-589-1970').insert('Biff Tanin', '520-589-1970');
//hashT.retrieveAll();
/*
[ ,
  [ [ 'Boo Radley', '520-589-1970' ],
    [ 'Tom Bradey', '520-589-1970' ] ],
  ,
  [ [ 'Alex Hawkins', '510-599-1930' ],
    [ 'Rick Mires', '520-589-1970' ] ],
  ,
  ,
  [ [ 'Biff Tanin', '520-589-1970' ] ] ]
*/

// Override example (Phone Number Change)
//
hashT.insert('Rick Mires', '650-589-1970').insert('Tom Bradey', '818-589-1970').insert('Biff Tanin', '987-589-1970');
//hashT.retrieveAll();

/*
[ ,
  [ [ 'Boo Radley', '520-589-1970' ],
    [ 'Tom Bradey', '818-589-1970' ] ],
  ,
  [ [ 'Alex Hawkins', '510-599-1930' ],
    [ 'Rick Mires', '650-589-1970' ] ],
  ,
  ,
  [ [ 'Biff Tanin', '987-589-1970' ] ] ]

*/

hashT.remove('Rick Mires');
hashT.remove('Tom Bradey');
//hashT.retrieveAll();

/*
[ ,
  [ [ 'Boo Radley', '520-589-1970' ] ],
  ,
  [ [ 'Alex Hawkins', '510-599-1930' ] ],
  ,
  ,
  [ [ 'Biff Tanin', '987-589-1970' ] ] ]


*/

hashT.insert('Dick Mires', '650-589-1970').insert('Lam James', '818-589-1970').insert('Ricky Ticky Tavi', '987-589-1970');
hashT.retrieveAll();


/* NOTICE HOW THE HASH TABLE HAS NOW DOUBLED IN SIZE UPON REACHING 75% CAPACITY, i.e. 6/8. It is now size 16.
 [,
  ,
  [ [ 'Vance Carter', '120-589-1970' ] ],
  [ [ 'Alex Hawkins', '510-599-1930' ],
    [ 'Dick Mires', '650-589-1970' ],
    [ 'Lam James', '818-589-1970' ] ],
  ,
  ,
  ,
  ,
  ,
  [ [ 'Boo Radley', '520-589-1970' ],
    [ 'Ricky Ticky Tavi', '987-589-1970' ] ],
  ,
  ,
  ,
  ,
  [ [ 'Biff Tanin', '987-589-1970' ] ] ]

*/

console.log(hashT.retrieve('Lam James'));  // 818-589-1970
console.log(hashT.retrieve('Dick Mires')); // 650-589-1970
console.log(hashT.retrieve('Ricky Ticky Tavi')); //987-589-1970
console.log(hashT.retrieve('Alex Hawkins')); // 510-599-1930
console.log(hashT.retrieve('Lebron James')); // null

How to split the screen with two equal LinearLayouts?

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <LinearLayout
            android:orientation="vertical"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            tools:context=".MainActivity">
            <TextView
                android:layout_marginTop="16dp"
                android:textSize="18sp"
                android:textStyle="bold"
                android:padding="4dp"
                android:textColor="#EA80FC"
                android:fontFamily="sans-serif-medium"
                android:text="@string/team_a"
                android:gravity="center_horizontal"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <TextView
                android:id="@+id/team_a_score"
                android:text="@string/_0"
                android:textSize="56sp"
                android:padding="4dp"
                android:gravity="center_horizontal"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <TextView
                android:id="@+id/team_a_fouls"
                android:text="@string/fouls"
                android:padding="4dp"
                android:textSize="26sp"
                android:gravity="center_horizontal"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_1_points"
                android:layout_width="match_parent"
                android:onClick="addOnePointTeamA"
                android:textColor="#fff"
                android:layout_margin="6dp"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_2_points"
                android:textColor="#fff"
                android:onClick="addTwoPointTeamA"
                android:layout_width="match_parent"
                android:layout_margin="6dp"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_3_points"
                android:textColor="#fff"
                android:onClick="addThreePointTeamA"
                android:layout_margin="6dp"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_1_point_foul"
                android:textColor="#fff"
                android:layout_width="match_parent"
                android:onClick="addOnePointFoulTeamA"
                android:layout_margin="6dp"
                android:layout_height="wrap_content" />
        </LinearLayout>
        <LinearLayout
            android:orientation="vertical"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            tools:context=".MainActivity">
            <TextView
                android:text="@string/team_b"
                android:textColor="#EA80FC"
                android:textStyle="bold"
                android:padding="4dp"
                android:layout_marginTop="16dp"
                android:fontFamily="sans-serif-medium"
                android:textSize="18sp"
                android:gravity="center_horizontal"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <TextView
                android:id="@+id/team_b_score"
                android:text="0"
                android:padding="4dp"
                android:textSize="56sp"
                android:gravity="center_horizontal"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <TextView
                android:id="@+id/team_b_fouls"
                android:text="Fouls"
                android:padding="4dp"
                android:textSize="26sp"
                android:gravity="center_horizontal"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_1_points"
                android:textColor="#fff"
                android:fontFamily="sans-serif-medium"
                android:layout_width="match_parent"
                android:onClick="addOnePointTeamB"
                android:layout_margin="6dp"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_2_points"
                android:layout_margin="6dp"
                android:fontFamily="sans-serif-medium"
                android:textColor="#fff"
                android:onClick="addTwoPointTeamB"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_3_points"
                android:fontFamily="sans-serif-medium"
                android:textColor="#fff"
                android:onClick="addThreePointTeamB"
                android:layout_margin="6dp"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
            <Button
                android:text="@string/_1_point_foul"
                android:textColor="#fff"
                android:onClick="addOnePointFoulTeamB"
                android:layout_width="match_parent"
                android:layout_margin="6dp"
                android:layout_height="wrap_content" />


        </LinearLayout>
    </LinearLayout>
    <Button
        android:text="@string/reset"
        android:layout_marginBottom="25dp"
        android:onClick="resetScore"
        android:textColor="#fff"
        android:fontFamily="sans-serif-medium"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</RelativeLayout>

Java Date vs Calendar

Date should be re-developed. Instead of being a long interger, it should hold year, month, date, hour, minute, second, as separate fields. It might be even good to store the calendar and time zone this date is associated with.

In our natural conversation, if setup an appointment at Nov. 1, 2013 1pm NY Time, this is a DateTime. It is NOT a Calendar. So we should be able to converse like this in Java as well.

When Date is stored as a long integer (of mili seconds since Jan 1 1970 or something), calculating its current date depends on the calendar. Different calendars will give different date. This is from the prospective of giving an absolute time (eg 1 trillion seconds after Big Bang). But often we also need a convenient way of conversation, like an object encapsulating year, month etc.

I wonder if there are new advances in Java to reconcile these 2 objectives. Maybe my java knowledge is too old.

CREATE FILE encountered operating system error 5(failed to retrieve text for this error. Reason: 15105)

It's a Windows permissions issue. If you connected to your server using Windows Authentication then that Windows user needs permissions to the file. If you connected to your server using SQL Server authentication then the SQL Server instance account (MSSQL$, e.g. MSSQL$SQLEXPRESS) needs permissions to the file. The other solutions suggesting logging in as an administrator essentially accomplish the same thing (with a bit of a sledgehammer :).

If the database file is in your SQL Server's data folder then it should have inherited the user rights for the SQL Server account from that folder so the SQL Server authentication should have worked. I would recommend fixing the SQL Server instance's account's rights for that folder. If the data file is somewhere else and the SQL Server account does not have permissions then you will likely encounter other problems later. Again, the better solution is to fix the SS account rights. Unless you are always going to log in as administrator...

How do you take a git diff file, and apply it to a local branch that is a copy of the same repository?

Copy the diff file to the root of your repository, and then do:

git apply yourcoworkers.diff

More information about the apply command is available on its man page.

By the way: A better way to exchange whole commits by file is the combination of the commands git format-patch on the sender and then git am on the receiver, because it also transfers the authorship info and the commit message.

If the patch application fails and if the commits the diff was generated from are actually in your repo, you can use the -3 option of apply that tries to merge in the changes.

It also works with Unix pipe as follows:

git diff d892531 815a3b5 | git apply

How do I find which process is leaking memory?

If you can't do it deductively, consider the Signal Flare debugging pattern: Increase the amount of memory allocated by one process by a factor of ten. Then run your program.

If the amount of the memory leaked is the same, that process was not the source of the leak; restore the process and make the same modification to the next process.

When you hit the process that is responsible, you'll see the size of your memory leak jump (the "signal flare"). You can narrow it down still further by selectively increasing the allocation size of separate statements within this process.

Javascript add method to object

There are many ways to create re-usable objects like this in JavaScript. Mozilla have a nice introduction here:

The following will work in your example:

function Foo(){
    this.bar = function (){
        alert("Hello World!");
    }
}

myFoo = new Foo();
myFoo.bar(); // Hello World?????????????????????????????????

What is the SQL command to return the field names of a table?

MySQL 3 and 4 (and 5):

desc tablename

which is an alias for

show fields from tablename

SQL Server (from 2000) and MySQL 5:

select COLUMN_NAME from INFORMATION_SCHEMA.COLUMNS 
where TABLE_NAME = 'tablename'

Completing the answer: like people below have said, in SQL Server you can also use the stored procedure sp_help

exec sp_help 'tablename'

How to create Gmail filter searching for text only at start of subject line?

The only option I have found to do this is find some exact wording and put that under the "Has the words" option. Its not the best option, but it works.

How do I add an integer value with javascript (jquery) to a value that's returning a string?

Your code should like this:

<span id="replies">8</span>

var currentValue = $("#replies").text();
var newValue = parseInt(parseFloat(currentValue)) + 1;
$("replies").text(newValue);

Hacks N Tricks

How to add element in Python to the end of list using list.insert?

list.insert with any index >= len(of_the_list) places the value at the end of list. It behaves like append

Python 3.7.4
>>>lst=[10,20,30]
>>>lst.insert(len(lst), 101)
>>>lst
[10, 20, 30, 101]
>>>lst.insert(len(lst)+50, 202)
>>>lst
[10, 20, 30, 101, 202]

Time complexity, append O(1), insert O(n)

Convert normal Java Array or ArrayList to Json Array in android

If you want or need to work with a Java array then you can always use the java.util.Arrays utility classes' static asList() method to convert your array to a List.

Something along those lines should work.

String mStringArray[] = { "String1", "String2" };

JSONArray mJSONArray = new JSONArray(Arrays.asList(mStringArray));

Beware that code is written offhand so consider it pseudo-code.

How to normalize a signal to zero mean and unit variance?

It seems like you are essentially looking into computing the z-score or standard score of your data, which is calculated through the formula: z = (x-mean(x))/std(x)

This should work:

%% Original data (Normal with mean 1 and standard deviation 2)
x = 1 + 2*randn(100,1);
mean(x)
var(x)
std(x)

%% Normalized data with mean 0 and variance 1
z = (x-mean(x))/std(x);
mean(z)
var(z)
std(z)

How to create a temporary directory and get the path / file name in Python

Use the mkdtemp() function from the tempfile module:

import tempfile
import shutil

dirpath = tempfile.mkdtemp()
# ... do stuff with dirpath
shutil.rmtree(dirpath)

.NET code to send ZPL to Zebra printers

This way you will be able to send ZPL to a printer no matter how it is connected (LPT, USB, Network Share...)

Create the RawPrinterHelper class (from the Microsoft article on How to send raw data to a printer by using Visual C# .NET):

using System;
using System.Drawing;
using System.Drawing.Printing;
using System.IO;
using System.Windows.Forms;
using System.Runtime.InteropServices;

public class RawPrinterHelper
{
    // Structure and API declarions:
    [StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)]
    public class DOCINFOA
    {
        [MarshalAs(UnmanagedType.LPStr)] public string pDocName;
        [MarshalAs(UnmanagedType.LPStr)] public string pOutputFile;
        [MarshalAs(UnmanagedType.LPStr)] public string pDataType;
    }
    [DllImport("winspool.Drv", EntryPoint="OpenPrinterA", SetLastError=true, CharSet=CharSet.Ansi, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
    public static extern bool OpenPrinter([MarshalAs(UnmanagedType.LPStr)] string szPrinter, out IntPtr hPrinter, IntPtr pd);

    [DllImport("winspool.Drv", EntryPoint="ClosePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
    public static extern bool ClosePrinter(IntPtr hPrinter);

    [DllImport("winspool.Drv", EntryPoint="StartDocPrinterA", SetLastError=true, CharSet=CharSet.Ansi, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
    public static extern bool StartDocPrinter( IntPtr hPrinter, Int32 level,  [In, MarshalAs(UnmanagedType.LPStruct)] DOCINFOA di);

    [DllImport("winspool.Drv", EntryPoint="EndDocPrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
    public static extern bool EndDocPrinter(IntPtr hPrinter);

    [DllImport("winspool.Drv", EntryPoint="StartPagePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
    public static extern bool StartPagePrinter(IntPtr hPrinter);

    [DllImport("winspool.Drv", EntryPoint="EndPagePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
    public static extern bool EndPagePrinter(IntPtr hPrinter);

    [DllImport("winspool.Drv", EntryPoint="WritePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
    public static extern bool WritePrinter(IntPtr hPrinter, IntPtr pBytes, Int32 dwCount, out Int32 dwWritten );

    // SendBytesToPrinter()
    // When the function is given a printer name and an unmanaged array
    // of bytes, the function sends those bytes to the print queue.
    // Returns true on success, false on failure.
    public static bool SendBytesToPrinter( string szPrinterName, IntPtr pBytes, Int32 dwCount)
    {
        Int32    dwError = 0, dwWritten = 0;
        IntPtr    hPrinter = new IntPtr(0);
        DOCINFOA    di = new DOCINFOA();
        bool    bSuccess = false; // Assume failure unless you specifically succeed.

        di.pDocName = "My C#.NET RAW Document";
        di.pDataType = "RAW";

        // Open the printer.
        if( OpenPrinter( szPrinterName.Normalize(), out hPrinter, IntPtr.Zero ) )
        {
            // Start a document.
            if( StartDocPrinter(hPrinter, 1, di) )
            {
                // Start a page.
                if( StartPagePrinter(hPrinter) )
                {
                    // Write your bytes.
                    bSuccess = WritePrinter(hPrinter, pBytes, dwCount, out dwWritten);
                    EndPagePrinter(hPrinter);
                }
                EndDocPrinter(hPrinter);
            }
            ClosePrinter(hPrinter);
        }
        // If you did not succeed, GetLastError may give more information
        // about why not.
        if( bSuccess == false )
        {
                dwError = Marshal.GetLastWin32Error();
        }
        return bSuccess;
    }

    public static bool SendFileToPrinter( string szPrinterName, string szFileName )
    {
        // Open the file.
        FileStream fs = new FileStream(szFileName, FileMode.Open);
        // Create a BinaryReader on the file.
        BinaryReader br = new BinaryReader(fs);
        // Dim an array of bytes big enough to hold the file's contents.
        Byte []bytes = new Byte[fs.Length];
        bool bSuccess = false;
        // Your unmanaged pointer.
        IntPtr pUnmanagedBytes = new IntPtr(0);
        int nLength;

        nLength = Convert.ToInt32(fs.Length);
        // Read the contents of the file into the array.
        bytes = br.ReadBytes( nLength );
        // Allocate some unmanaged memory for those bytes.
        pUnmanagedBytes = Marshal.AllocCoTaskMem(nLength);
        // Copy the managed byte array into the unmanaged array.
        Marshal.Copy(bytes, 0, pUnmanagedBytes, nLength);
        // Send the unmanaged bytes to the printer.
        bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, nLength);
        // Free the unmanaged memory that you allocated earlier.
        Marshal.FreeCoTaskMem(pUnmanagedBytes);
        return bSuccess;
    }
    public static bool SendStringToPrinter( string szPrinterName, string szString )
    {
        IntPtr pBytes;
        Int32 dwCount;
        // How many characters are in the string?
        dwCount = szString.Length;
        // Assume that the printer is expecting ANSI text, and then convert
        // the string to ANSI text.
        pBytes = Marshal.StringToCoTaskMemAnsi(szString);
        // Send the converted ANSI string to the printer.
        SendBytesToPrinter(szPrinterName, pBytes, dwCount);
        Marshal.FreeCoTaskMem(pBytes);
        return true;
    }
}

Call the print method:

private void BtnPrint_Click(object sender, System.EventArgs e)
{
    string s = "^XA^LH30,30\n^FO20,10^ADN,90,50^AD^FDHello World^FS\n^XZ";

    PrintDialog pd  = new PrintDialog();
    pd.PrinterSettings = new PrinterSettings();
    if(DialogResult.OK == pd.ShowDialog(this))
    {
        RawPrinterHelper.SendStringToPrinter(pd.PrinterSettings.PrinterName, s);
    }
}

There are 2 gotchas I've come across that happen when you're sending txt files with ZPL codes to the printer:

  1. The file has to end with a new line character
  2. Encoding has to be set to Encoding.Default when reading ANSI txt files with special characters

    public static bool SendTextFileToPrinter(string szFileName, string printerName)
    {
        var sb = new StringBuilder();
    
        using (var sr = new StreamReader(szFileName, Encoding.Default))
        {
            while (!sr.EndOfStream)
            {
                sb.AppendLine(sr.ReadLine());
            }
        }
    
        return RawPrinterHelper.SendStringToPrinter(printerName, sb.ToString());
    }
    

How do I concatenate strings?

2020 Update: Concatenation by String Interpolation

RFC 2795 issued 2019-10-27: Suggests support for implicit arguments to do what many people would know as "string interpolation" -- a way of embedding arguments within a string to concatenate them.

RFC: https://rust-lang.github.io/rfcs/2795-format-args-implicit-identifiers.html

Latest issue status can be found here: https://github.com/rust-lang/rust/issues/67984

At the time of this writing (2020-9-24), I believe this feature should be available in the Rust Nightly build.

This will allow you to concatenate via the following shorthand:

format_args!("hello {person}")

It is equivalent to this:

format_args!("hello {person}", person=person)

There is also the "ifmt" crate, which provides its own kind of string interpolation:

https://crates.io/crates/ifmt

java.lang.RuntimeException: Unable to instantiate activity ComponentInfo

Right click on project > properties > android > and try with different version of the android earlier i was doing with android 4.4 then i changed to android 4.3 and it worked !

Find size and free space of the filesystem containing a given file

If you just need the free space on a device, see the answer using os.statvfs() below.

If you also need the device name and mount point associated with the file, you should call an external program to get this information. df will provide all the information you need -- when called as df filename it prints a line about the partition that contains the file.

To give an example:

import subprocess
df = subprocess.Popen(["df", "filename"], stdout=subprocess.PIPE)
output = df.communicate()[0]
device, size, used, available, percent, mountpoint = \
    output.split("\n")[1].split()

Note that this is rather brittle, since it depends on the exact format of the df output, but I'm not aware of a more robust solution. (There are a few solutions relying on the /proc filesystem below that are even less portable than this one.)

How can I define fieldset border color?

I added it for all fieldsets with

fieldset {
        border: 1px solid lightgray;
    }

I didnt work if I set it separately using for example

border-color : red

. Then a black line was drawn next to the red line.

Referring to the null object in Python

Null is a special object type like:

>>>type(None)
<class 'NoneType'>

You can check if an object is in class 'NoneType':

>>>variable = None
>>>variable is None
True

More information is available at Python Docs

Remove specific characters from a string in Javascript

Simply replace it with nothing:

var string = 'F0123456'; // just an example
string.replace(/^F0+/i, ''); '123456'

How can I add a key/value pair to a JavaScript object?

According to Property Accessors defined in ECMA-262(http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-262.pdf, P67), there are two ways you can do to add properties to a exists object. All these two way, the Javascript engine will treat them the same.

The first way is to use dot notation:

obj.key3 = value3;

But this way, you should use a IdentifierName after dot notation.

The second way is to use bracket notation:

obj["key3"] = value3;

and another form:

var key3 = "key3";
obj[key3] = value3;

This way, you could use a Expression (include IdentifierName) in the bracket notation.

Simple GUI Java calculator

This is the working code...

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;

public class JavaCalculator extends JFrame {

    private JButton jbtNum1;
    private JButton jbtNum2;
    private JButton jbtNum3;
    private JButton jbtNum4;
    private JButton jbtNum5;
    private JButton jbtNum6;
    private JButton jbtNum7;
    private JButton jbtNum8;
    private JButton jbtNum9;
    private JButton jbtNum0;
    private JButton jbtEqual;
    private JButton jbtAdd;
    private JButton jbtSubtract;
    private JButton jbtMultiply;
    private JButton jbtDivide;
    private JButton jbtSolve;
    private JButton jbtClear;
    private double TEMP;
    private double SolveTEMP;
    private JTextField jtfResult;

    Boolean addBool = false;
    Boolean subBool = false;
    Boolean divBool = false;
    Boolean mulBool = false;

    String display = "";

    public JavaCalculator() {

        JPanel p1 = new JPanel();
        p1.setLayout(new GridLayout(4, 3));
        p1.add(jbtNum1 = new JButton("1"));
        p1.add(jbtNum2 = new JButton("2"));
        p1.add(jbtNum3 = new JButton("3"));
        p1.add(jbtNum4 = new JButton("4"));
        p1.add(jbtNum5 = new JButton("5"));
        p1.add(jbtNum6 = new JButton("6"));
        p1.add(jbtNum7 = new JButton("7"));
        p1.add(jbtNum8 = new JButton("8"));
        p1.add(jbtNum9 = new JButton("9"));
        p1.add(jbtNum0 = new JButton("0"));
        p1.add(jbtClear = new JButton("C"));

        JPanel p2 = new JPanel();
        p2.setLayout(new FlowLayout());
        p2.add(jtfResult = new JTextField(20));
        jtfResult.setHorizontalAlignment(JTextField.RIGHT);
        jtfResult.setEditable(false);

        JPanel p3 = new JPanel();
        p3.setLayout(new GridLayout(5, 1));
        p3.add(jbtAdd = new JButton("+"));
        p3.add(jbtSubtract = new JButton("-"));
        p3.add(jbtMultiply = new JButton("*"));
        p3.add(jbtDivide = new JButton("/"));
        p3.add(jbtSolve = new JButton("="));

        JPanel p = new JPanel();
        p.setLayout(new GridLayout());
        p.add(p2, BorderLayout.NORTH);
        p.add(p1, BorderLayout.SOUTH);
        p.add(p3, BorderLayout.EAST);

        add(p);

        jbtNum1.addActionListener(new ListenToOne());
        jbtNum2.addActionListener(new ListenToTwo());
        jbtNum3.addActionListener(new ListenToThree());
        jbtNum4.addActionListener(new ListenToFour());
        jbtNum5.addActionListener(new ListenToFive());
        jbtNum6.addActionListener(new ListenToSix());
        jbtNum7.addActionListener(new ListenToSeven());
        jbtNum8.addActionListener(new ListenToEight());
        jbtNum9.addActionListener(new ListenToNine());
        jbtNum0.addActionListener(new ListenToZero());

        jbtAdd.addActionListener(new ListenToAdd());
        jbtSubtract.addActionListener(new ListenToSubtract());
        jbtMultiply.addActionListener(new ListenToMultiply());
        jbtDivide.addActionListener(new ListenToDivide());
        jbtSolve.addActionListener(new ListenToSolve());
        jbtClear.addActionListener(new ListenToClear());
    } //JavaCaluclator()

    class ListenToClear implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            //display = jtfResult.getText();
            jtfResult.setText("");
            addBool = false;
            subBool = false;
            mulBool = false;
            divBool = false;

            TEMP = 0;
            SolveTEMP = 0;
        }
    }

    class ListenToOne implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            display = jtfResult.getText();
            jtfResult.setText(display + "1");
        }
    }

    class ListenToTwo implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            display = jtfResult.getText();
            jtfResult.setText(display + "2");
        }
    }

    class ListenToThree implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            display = jtfResult.getText();
            jtfResult.setText(display + "3");
        }
    }

    class ListenToFour implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            display = jtfResult.getText();
            jtfResult.setText(display + "4");
        }
    }

    class ListenToFive implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            display = jtfResult.getText();
            jtfResult.setText(display + "5");
        }
    }

    class ListenToSix implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            display = jtfResult.getText();
            jtfResult.setText(display + "6");
        }
    }

    class ListenToSeven implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            display = jtfResult.getText();
            jtfResult.setText(display + "7");
        }
    }

    class ListenToEight implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            display = jtfResult.getText();
            jtfResult.setText(display + "8");
        }
    }

    class ListenToNine implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            display = jtfResult.getText();
            jtfResult.setText(display + "9");
        }
    }

    class ListenToZero implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            display = jtfResult.getText();
            jtfResult.setText(display + "0");
        }
    }

    class ListenToAdd implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            TEMP = Double.parseDouble(jtfResult.getText());
            jtfResult.setText("");
            addBool = true;
        }
    }

    class ListenToSubtract implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            TEMP = Double.parseDouble(jtfResult.getText());
            jtfResult.setText("");
            subBool = true;
        }
    }

    class ListenToMultiply implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            TEMP = Double.parseDouble(jtfResult.getText());
            jtfResult.setText("");
            mulBool = true;
        }
    }

    class ListenToDivide implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            TEMP = Double.parseDouble(jtfResult.getText());
            jtfResult.setText("");
            divBool = true;
        }
    }

    class ListenToSolve implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            SolveTEMP = Double.parseDouble(jtfResult.getText());
            if (addBool == true)
                SolveTEMP = SolveTEMP + TEMP;
            else if ( subBool == true)
                SolveTEMP = SolveTEMP - TEMP;
            else if ( mulBool == true)
                SolveTEMP = SolveTEMP * TEMP;
            else if ( divBool == true)
                            SolveTEMP = SolveTEMP / TEMP;
            jtfResult.setText(  Double.toString(SolveTEMP));

            addBool = false;
            subBool = false;
            mulBool = false;
            divBool = false;
        }
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        JavaCalculator calc = new JavaCalculator();
        calc.pack();
        calc.setLocationRelativeTo(null);
                calc.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        calc.setVisible(true);
    }

} //JavaCalculator

How to run a .jar in mac?

Make Executable your jar and after that double click on it on Mac OS then it works successfully.

sudo chmod +x filename.jar

Try this, I hope this works.

close fancy box from function from within open 'fancybox'

Bit of an old thread but ...

Actually, I suspect that the answer to the original question about how to close the window from within the window has more to do with the fact that the click event is not attached to the element. If the click event is attached in document.ready the event will not be attached when fancybox creates the new window.

You need to re-apply the click event once the new window . Probably the easiest way to do this is to use onComplete feature.

This works for me:

$(".popup").fancybox({
    'transitionIn'  :   'fade',
    'transitionOut' :   'elastic',
    'speedIn'       :   600, 
    'speedOut'      :   400, 
    'overlayShow'   :   true,
    'overlayColor'  :   '#000022',
            'overlayOpacity'  : 0.8,
            'onComplete' : function(){$('.closer').click(function(){parent.$.fancybox.close();})}
});

Actually, after a bit of thought 'live' rather than 'click' or 'bind' might work just as well.

How to style a div to be a responsive square?

It is as easy as specifying a padding bottom the same size as the width in percent. So if you have a width of 50%, just use this example below

id or class{
    width: 50%;
    padding-bottom: 50%;
}

Here is a jsfiddle http://jsfiddle.net/kJL3u/2/

Edited version with responsive text: http://jsfiddle.net/kJL3u/394

Compare two List<T> objects for equality, ignoring order

I use this method )

public delegate bool CompareValue<in T1, in T2>(T1 val1, T2 val2);

public static bool CompareTwoArrays<T1, T2>(this IEnumerable<T1> array1, IEnumerable<T2> array2, CompareValue<T1, T2> compareValue)
{
    return array1.Select(item1 => array2.Any(item2 => compareValue(item1, item2))).All(search => search)
            && array2.Select(item2 => array1.Any(item1 => compareValue(item1, item2))).All(search => search);
}

Detecting Windows or Linux?

Useful simple class are forked by me on: https://gist.github.com/kiuz/816e24aa787c2d102dd0

public class OSValidator {

    private static String OS = System.getProperty("os.name").toLowerCase();

    public static void main(String[] args) {

        System.out.println(OS);

        if (isWindows()) {
            System.out.println("This is Windows");
        } else if (isMac()) {
            System.out.println("This is Mac");
        } else if (isUnix()) {
            System.out.println("This is Unix or Linux");
        } else if (isSolaris()) {
            System.out.println("This is Solaris");
        } else {
            System.out.println("Your OS is not support!!");
        }
    }

    public static boolean isWindows() {
        return OS.contains("win");
    }

    public static boolean isMac() {
        return OS.contains("mac");
    }

    public static boolean isUnix() {
        return (OS.contains("nix") || OS.contains("nux") || OS.contains("aix"));
    }

    public static boolean isSolaris() {
        return OS.contains("sunos");
    }
    public static String getOS(){
        if (isWindows()) {
            return "win";
        } else if (isMac()) {
            return "osx";
        } else if (isUnix()) {
            return "uni";
        } else if (isSolaris()) {
            return "sol";
        } else {
            return "err";
        }
    }

}

CSS3's border-radius property and border-collapse:collapse don't mix. How can I use border-radius to create a collapsed table with rounded corners?

The following method works (tested in Chrome) by using a box-shadow with a spread of 1px instead of a "real" border.

_x000D_
_x000D_
    table {
        border-collapse: collapse;
        border-radius: 30px;
        border-style: hidden; /* hide standard table (collapsed) border */
        box-shadow: 0 0 0 1px #666; /* this draws the table border  */ 
    }

    td {
        border: 1px solid #ccc;
    }
_x000D_
<table>
  <thead>
    <tr>
      <th>Foo</th>
      <th>Bar</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Baz</td>
      <td>Qux</td>
    </tr>
    <tr>
      <td>Life is short</td>
      <td rowspan="3">and</td>
    </tr>
    <tr>
      <td>Love</td>
    </tr>
    <tr>
      <td>is always over</td>
    </tr>
    <tr>
      <td>In the</td>
      <td>Morning</td>
    </tr>
  </tbody>
</table>
_x000D_
_x000D_
_x000D_

jQuery find events handlers registered with an object

I've combined both solutions from @jps to one function:

jQuery.fn.getEvents = function() {
    if (typeof(jQuery._data) === 'function') {
        return jQuery._data(this.get(0), 'events') || {};
    }

    // jQuery version < 1.7.?
    if (typeof(this.data) === 'function') {
        return this.data('events') || {};
    }

    return {};
};

But beware, this function can only return events that were set using jQuery itself.

LaTeX Optional Arguments

Here's my attempt, it doesn't follow your specs exactly though. Not fully tested, so be cautious.

\newcount\seccount

\def\sec{%
    \seccount0%
    \let\go\secnext\go
}

\def\secnext#1{%
    \def\last{#1}%
    \futurelet\next\secparse
}

\def\secparse{%
    \ifx\next\bgroup
        \let\go\secparseii
    \else
        \let\go\seclast
    \fi
    \go
}

\def\secparseii#1{%
    \ifnum\seccount>0, \fi
    \advance\seccount1\relax
    \last
    \def\last{#1}%
    \futurelet\next\secparse
}

\def\seclast{\ifnum\seccount>0{} and \fi\last}%

\sec{a}{b}{c}{d}{e}
% outputs "a, b, c, d and e"

\sec{a}
% outputs "a"

\sec{a}{b}
% outputs "a and b"

MySQL root access from all hosts

I'm using AWS LightSail and for my instance to work, I had to change:

bind-address = 127.0.0.1

to

bind-address = <Private IP Assigned by Amazon>

Then I was able to connect remotely.

How do I create a list of random numbers without duplicates?

In order to obtain a program that generates a list of random values without duplicates that is deterministic, efficient and built with basic programming constructs consider the function extractSamples defined below,

def extractSamples(populationSize, sampleSize, intervalLst) :
    import random
    if (sampleSize > populationSize) :
        raise ValueError("sampleSize = "+str(sampleSize) +" > populationSize (= " + str(populationSize) + ")")
    samples = []
    while (len(samples) < sampleSize) :
        i = random.randint(0, (len(intervalLst)-1))
        (a,b) = intervalLst[i]
        sample = random.randint(a,b)
        if (a==b) :
            intervalLst.pop(i)
        elif (a == sample) : # shorten beginning of interval                                                                                                                                           
            intervalLst[i] = (sample+1, b)
        elif ( sample == b) : # shorten interval end                                                                                                                                                   
            intervalLst[i] = (a, sample - 1)
        else :
            intervalLst[i] = (a, sample - 1)
            intervalLst.append((sample+1, b))
        samples.append(sample)
    return samples

The basic idea is to keep track of intervals intervalLst for possible values from which to select our required elements from. This is deterministic in the sense that we are guaranteed to generate a sample within a fixed number of steps (solely dependent on populationSize and sampleSize).

To use the above function to generate our required list,

In [3]: populationSize, sampleSize = 10**17, 10**5

In [4]: %time lst1 = extractSamples(populationSize, sampleSize, [(0, populationSize-1)])
CPU times: user 289 ms, sys: 9.96 ms, total: 299 ms
Wall time: 293 ms

We may also compare with an earlier solution (for a lower value of populationSize)

In [5]: populationSize, sampleSize = 10**8, 10**5

In [6]: %time lst = random.sample(range(populationSize), sampleSize)
CPU times: user 1.89 s, sys: 299 ms, total: 2.19 s
Wall time: 2.18 s

In [7]: %time lst1 = extractSamples(populationSize, sampleSize, [(0, populationSize-1)])
CPU times: user 449 ms, sys: 8.92 ms, total: 458 ms
Wall time: 442 ms

Note that I reduced populationSize value as it produces Memory Error for higher values when using the random.sample solution (also mentioned in previous answers here and here). For above values, we can also observe that extractSamples outperforms the random.sample approach.

P.S. : Though the core approach is similar to my earlier answer, there are substantial modifications in implementation as well as approach alongwith improvement in clarity.

AttributeError: module 'cv2.cv2' has no attribute 'createLBPHFaceRecognizer'

I had a similar problem:

module cv2 has no attribute "cv2.TrackerCSRT_create"

My Python version is 3.8.0 under Windows 10. The problem was the opencv version installation.

So I fixed this way (cmd prompt with administrator privileges):

  1. Uninstalled opencv-python: pip uninstall opencv-python
  2. Installed only opencv-contrib-python: pip install opencv-contrib-python

Anyway you can read the following guide:

https://github.com/skvark/opencv-python

Seaborn Barplot - Displaying Values

Just in case if anyone is interested in labeling horizontal barplot graph, I modified Sharon's answer as below:

def show_values_on_bars(axs, h_v="v", space=0.4):
    def _show_on_single_plot(ax):
        if h_v == "v":
            for p in ax.patches:
                _x = p.get_x() + p.get_width() / 2
                _y = p.get_y() + p.get_height()
                value = int(p.get_height())
                ax.text(_x, _y, value, ha="center") 
        elif h_v == "h":
            for p in ax.patches:
                _x = p.get_x() + p.get_width() + float(space)
                _y = p.get_y() + p.get_height()
                value = int(p.get_width())
                ax.text(_x, _y, value, ha="left")

    if isinstance(axs, np.ndarray):
        for idx, ax in np.ndenumerate(axs):
            _show_on_single_plot(ax)
    else:
        _show_on_single_plot(axs)

Two parameters explained:

h_v - Whether the barplot is horizontal or vertical. "h" represents the horizontal barplot, "v" represents the vertical barplot.

space - The space between value text and the top edge of the bar. Only works for horizontal mode.

Example:

show_values_on_bars(sns_t, "h", 0.3)

enter image description here

Use multiple custom fonts using @font-face?

You can use multiple font faces quite easily. Below is an example of how I used it in the past:

<!--[if (IE)]><!-->
    <style type="text/css" media="screen">
        @font-face {
            font-family: "Century Schoolbook";
            src: url(/fonts/century-schoolbook.eot);
        }
        @font-face {
            font-family: "Chalkduster";
            src: url(/fonts/chalkduster.eot);
        }
    </style>
<!--<![endif]-->
<!--[if !(IE)]><!-->
    <style type="text/css" media="screen">
        @font-face {
            font-family: "Century Schoolbook";
            src: url(/fonts/century-schoolbook.ttf);
        }
        @font-face {
            font-family: "Chalkduster";
            src: url(/fonts/chalkduster.ttf);
        }
    </style>
<!--<![endif]-->

It is worth noting that fonts can be funny across different Browsers. Font face on earlier browsers works, but you need to use eot files instead of ttf.

That is why I include my fonts in the head of the html file as I can then use conditional IE tags to use eot or ttf files accordingly.

If you need to convert ttf to eot for this purpose there is a brilliant website you can do this for free online, which can be found at http://ttf2eot.sebastiankippe.com/.

Hope that helps.

How do I turn off the output from tar commands on Unix?

Just drop the option v.

-v is for verbose. If you don't use it then it won't display:

tar -zxf tmp.tar.gz -C ~/tmp1

Change a Django form field to a hidden field

an option that worked for me, define the field in the original form as:

forms.CharField(widget = forms.HiddenInput(), required = False)

then when you override it in the new Class it will keep it's place.

Get the contents of a table row with a button click

Try this:

$(".use-address").click(function() {
   $(this).closest('tr').find('td').each(function() {
        var textval = $(this).text(); // this will be the text of each <td>
   });
});

This will find the closest tr (going up through the DOM) of the currently clicked button and then loop each td - you might want to create a string / array with the values.

Example here

Getting the full address using an array example here

Gradle: Could not determine java version from '11.0.2'

I've had the same issue. Upgrading to gradle 5.0 did the trick for me.

This link provides detailed steps on how install gradle 5.0: https://linuxize.com/post/how-to-install-gradle-on-ubuntu-18-04/

iOS how to set app icon and launch images

This is a very frustrating part of XCode. Like many, I wasted hours on this when I switched to a newer version of xcode (version 8). The solution for me was to open the properties for my project and under the "App Icons and Launch Images" choose the "migrate" option for the icons. This made absolutely no sense to me as I already had all my icons there, but it worked! Unfortunately I now seem to have two copies of my launcher icons in the project though.

Best way to define private methods for a class in Objective-C

every objects in Objective C conform to NSObject protocol, which holds onto the performSelector: method. I was also previously looking for a way to create some "helper or private" methods that I did not need exposed on a public level. If you want to create a private method with no overhead and not having to define it in your header file then give this a shot...

define the your method with a similar signature as the code below...

-(void)myHelperMethod: (id) sender{
     // code here...
}

then when you need to reference the method simply call it as a selector...

[self performSelector:@selector(myHelperMethod:)];

this line of code will invoke the method you created and not have an annoying warning about not having it defined in the header file.

How to compare data between two table in different databases using Sql Server 2008?

If both database on same server. You can check similar tables by using following query :

select 
      fdb.name, sdb.name 
from 
      FIRSTDBNAME.sys.tables fdb 
      join SECONDDBNAME.sys.tables sdb
      on fdb.name = sdb.name -- compare same name tables
order by 
      1     

By listing out similar table you can compare columns schema using sys.columns view.

Hope this helps you.

Converting Swagger specification JSON to HTML documentation

I was not satisfied with swagger-codegen when I was looking for a tool to do this, so I wrote my own. Have a look at bootprint-swagger

The main goal compared to swagger-codegen is to provide an easy setup (though you'll need nodejs). And it should be easy to adapt styling and templates to your own needs, which is a core functionality of the bootprint-project

Use of 'prototype' vs. 'this' in JavaScript?

I know this has been answered to death but I'd like to show an actual example of speed differences.

Function directly on object:

_x000D_
_x000D_
function ExampleFn() {
    this.print = function() {
        console.log("Calling print! ");
    }
}

var objects = [];
console.time('x');
for (let i = 0; i < 2000000; i++) {
    objects.push(new ExampleFn());
}
console.timeEnd('x');

//x: 1151.960693359375ms
_x000D_
_x000D_
_x000D_

Function on prototype:

_x000D_
_x000D_
function ExampleFn() {
}
ExampleFn.prototype.print = function() {
    console.log("Calling print!");
}

var objects = [];
console.time('y');
for (let i = 0; i < 2000000; i++) {
    objects.push(new ExampleFn());
}
console.timeEnd('y');

//x: 617.866943359375ms
_x000D_
_x000D_
_x000D_

Here we're creating 2,000,000 new objects with a print method in Chrome. We're storing every object in an array. Putting print on the prototype takes about 1/2 as long.

How to convert Varchar to Int in sql server 2008?

That is the correct way to convert it to an INT as long as you don't have any alpha characters or NULL values.

If you have any NULL values, use

ISNULL(column1, 0)

How to list all tags along with the full message in git?

Try this it will list all the tags along with annotations & 9 lines of message for every tag:

git tag -n9

can also use

git tag -l -n9

if specific tags are to list:

git tag -l -n9 v3.*

(e.g, above command will only display tags starting with "v3.")

-l , --list List tags with names that match the given pattern (or all if no pattern is given). Running "git tag" without arguments also lists all tags. The pattern is a shell wildcard (i.e., matched using fnmatch(3)). Multiple patterns may be given; if any of them matches, the tag is shown.

Selectors in Objective-C?

In this case, the name of the selector is wrong. The colon here is part of the method signature; it means that the method takes one argument. I believe that you want

SEL sel = @selector(lowercaseString);

How can I plot separate Pandas DataFrames as subplots?

Building on @joris response above, if you have already established a reference to the subplot, you can use the reference as well. For example,

ax1 = plt.subplot2grid((50,100), (0, 0), colspan=20, rowspan=10)
...

df.plot.barh(ax=ax1, stacked=True)

Working with TIFFs (import, export) in Python using numpy

PyLibTiff worked better for me than PIL, which as of December 2020 still doesn't support color images with more than 8 bits per color.

from libtiff import TIFF

tif = TIFF.open('filename.tif') # open tiff file in read mode
# read an image in the currect TIFF directory as a numpy array
image = tif.read_image()

# read all images in a TIFF file:
for image in tif.iter_images(): 
    pass

tif = TIFF.open('filename.tif', mode='w')
tif.write_image(image)

You can install PyLibTiff with

pip3 install numpy libtiff

The readme of PyLibTiff also mentions the tifffile library but I haven't tried it.

How to reset AUTO_INCREMENT in MySQL?

it is for empty table:

ALTER TABLE `table_name` AUTO_INCREMENT = 1;

if you have data but you want to tidy up it, i recommend use this :

ALTER TABLE `table_name` DROP `auto_colmn`;
ALTER TABLE `table_name` ADD  `auto_colmn` INT( {many you want} ) NOT NULL AUTO_INCREMENT FIRST ,ADD PRIMARY KEY (`auto_colmn`);

Using getopts to process long and short command line options

In case you don't want the getopt dependency, you can do this:

while test $# -gt 0
do
  case $1 in

  # Normal option processing
    -h | --help)
      # usage and help
      ;;
    -v | --version)
      # version info
      ;;
  # ...

  # Special cases
    --)
      break
      ;;
    --*)
      # error unknown (long) option $1
      ;;
    -?)
      # error unknown (short) option $1
      ;;

  # FUN STUFF HERE:
  # Split apart combined short options
    -*)
      split=$1
      shift
      set -- $(echo "$split" | cut -c 2- | sed 's/./-& /g') "$@"
      continue
      ;;

  # Done with options
    *)
      break
      ;;
  esac

  # for testing purposes:
  echo "$1"

  shift
done

Of course, then you can't use long style options with one dash. And if you want to add shortened versions (e.g. --verbos instead of --verbose), then you need to add those manually.

But if you are looking to get getopts functionality along with long options, this is a simple way to do it.

I also put this snippet in a gist.

SQL JOIN and different types of JOINs

Definition:


JOINS are way to query the data that combined together from multiple tables simultaneously.

Types of JOINS:


Concern to RDBMS there are 5-types of joins:

  • Equi-Join: Combines common records from two tables based on equality condition. Technically, Join made by using equality-operator (=) to compare values of Primary Key of one table and Foreign Key values of another table, hence result set includes common(matched) records from both tables. For implementation see INNER-JOIN.

  • Natural-Join: It is enhanced version of Equi-Join, in which SELECT operation omits duplicate column. For implementation see INNER-JOIN

  • Non-Equi-Join: It is reverse of Equi-join where joining condition is uses other than equal operator(=) e.g, !=, <=, >=, >, < or BETWEEN etc. For implementation see INNER-JOIN.

  • Self-Join:: A customized behavior of join where a table combined with itself; This is typically needed for querying self-referencing tables (or Unary relationship entity). For implementation see INNER-JOINs.

  • Cartesian Product: It cross combines all records of both tables without any condition. Technically, it returns the result set of a query without WHERE-Clause.

As per SQL concern and advancement, there are 3-types of joins and all RDBMS joins can be achieved using these types of joins.

  1. INNER-JOIN: It merges(or combines) matched rows from two tables. The matching is done based on common columns of tables and their comparing operation. If equality based condition then: EQUI-JOIN performed, otherwise Non-EQUI-Join.

  2. OUTER-JOIN: It merges(or combines) matched rows from two tables and unmatched rows with NULL values. However, can customized selection of un-matched rows e.g, selecting unmatched row from first table or second table by sub-types: LEFT OUTER JOIN and RIGHT OUTER JOIN.

    2.1. LEFT Outer JOIN (a.k.a, LEFT-JOIN): Returns matched rows from two tables and unmatched from the LEFT table(i.e, first table) only.

    2.2. RIGHT Outer JOIN (a.k.a, RIGHT-JOIN): Returns matched rows from two tables and unmatched from the RIGHT table only.

    2.3. FULL OUTER JOIN (a.k.a OUTER JOIN): Returns matched and unmatched from both tables.

  3. CROSS-JOIN: This join does not merges/combines instead it performs Cartesian product.

enter image description here Note: Self-JOIN can be achieved by either INNER-JOIN, OUTER-JOIN and CROSS-JOIN based on requirement but the table must join with itself.

For more information:

Examples:

1.1: INNER-JOIN: Equi-join implementation

SELECT  *
FROM Table1 A 
 INNER JOIN Table2 B ON A.<Primary-Key> =B.<Foreign-Key>;

1.2: INNER-JOIN: Natural-JOIN implementation

Select A.*, B.Col1, B.Col2          --But no B.ForeignKeyColumn in Select
 FROM Table1 A
 INNER JOIN Table2 B On A.Pk = B.Fk;

1.3: INNER-JOIN with NON-Equi-join implementation

Select *
 FROM Table1 A INNER JOIN Table2 B On A.Pk <= B.Fk;

1.4: INNER-JOIN with SELF-JOIN

Select *
 FROM Table1 A1 INNER JOIN Table1 A2 On A1.Pk = A2.Fk;

2.1: OUTER JOIN (full outer join)

Select *
 FROM Table1 A FULL OUTER JOIN Table2 B On A.Pk = B.Fk;

2.2: LEFT JOIN

Select *
 FROM Table1 A LEFT OUTER JOIN Table2 B On A.Pk = B.Fk;

2.3: RIGHT JOIN

Select *
 FROM Table1 A RIGHT OUTER JOIN Table2 B On A.Pk = B.Fk;

3.1: CROSS JOIN

Select *
 FROM TableA CROSS JOIN TableB;

3.2: CROSS JOIN-Self JOIN

Select *
 FROM Table1 A1 CROSS JOIN Table1 A2;

//OR//

Select *
 FROM Table1 A1,Table1 A2;

How to log a method's execution time exactly in milliseconds?

OK, if your objective is to find out what you can fix to make it faster, that's a little different goal. Measuring the time that functions take is a good way to find out if what you did made a difference, but to find out what to do you need a different technique. This is what I recommend, and I know you can do it on iPhones.

Edit: Reviewers suggested I elaborate the answer, so I'm trying to think of a brief way to say it.
Your overall program takes enough clock time to bother you. Suppose that's N seconds.
You're assuming you can speed it up. The only way you can do that is by making it not do something it's doing in that time, accounting for m seconds.
You don't initially know what that thing is. You can guess, as all programmers do, but it could easily be something else. Whatever it is, here's how you can find it:

Since that thing, whatever it is, accounts for fraction m/N of the time, that means if you pause it at random the probability is m/N that you will catch it in the act of doing that thing. Of course it might be doing something else, but pause it and see what it's doing.
Now do it again. If you see it doing that same thing again, you can be more suspicious.

Do it 10 times, or 20. Now if you see it doing some particular thing (no matter how you describe it) on multiple pauses, that you can get rid of, you know two things. You know very roughly what fraction of time it takes, but you know very exactly what to fix.
If you also want to know very exactly how much time will be saved, that's easy. Measure it before, fix it, and measure it after. If you're really disappointed, back out the fix.

Do you see how this is different from measuring? It's finding, not measuring. Most profiling is based on measuring as exactly as possible how much time is taken, as if that's important, and hand-waves the problem of identifying what needs to be fixed. Profiling does not find every problem, but this method does find every problem, and it's the problems you don't find that hurt you.

Finding the length of a Character Array in C

There is also a compact form for that, if you do not want to rely on strlen. Assuming that the character array you are considering is "msg":

  unsigned int len=0;
  while(*(msg+len) ) len++;

How to use random in BATCH script?

@echo off
title Professional Hacker
color 02
:matrix
echo %random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%
echo %random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%% 
echo %random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%
echo %random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%
echo %random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%
echo %random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%
echo %random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%% 
echo %random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%%random%% 
goto matrix

Python append() vs. + operator on lists, why do these give different results?

Python lists are heterogeneous that is the elements in the same list can be any type of object. The expression: c.append(c) appends the object c what ever it may be to the list. In the case it makes the list itself a member of the list.

The expression c += c adds two lists together and assigns the result to the variable c. The overloaded + operator is defined on lists to create a new list whose contents are the elements in the first list and the elements in the second list.

So these are really just different expressions used to do different things by design.

Determine if Python is running inside virtualenv

This is an old question, but too many examples above are over-complicated.

Keep It Simple: (in Jupyter Notebook or Python 3.7.1 terminal on Windows 10)


import sys
print(sys.executable)```

# example output: >> `C:\Anaconda3\envs\quantecon\python.exe`

OR 
```sys.base_prefix```

# Example output: >> 'C:\\Anaconda3\\envs\\quantecon'

How to download dependencies in gradle

You should try this one :

task getDeps(type: Copy) {
    from configurations.runtime
    into 'runtime/'
}

I was was looking for it some time ago when working on a project in which we had to download all dependencies into current working directory at some point in our provisioning script. I guess you're trying to achieve something similar.

CSS: Position loading indicator in the center of the screen

Here is a solution using an overlay that inhibits along with material design spinner that you configure one time in your app and you can call it from anywhere.

app.component.html

(put this somewhere at the root level of your html)

<div class="overlay" [style.height.px]="height" [style.width.px]="width" *ngIf="message.plzWait$ | async">
        <mat-spinner class="plzWait"  mode="indeterminate"></mat-spinner>
</div>

app.component.css

.plzWait{
  position: relative;
  left: calc(50% - 50px);
  top:50%;

}
.overlay{
  position: absolute;
  top:0px;
  left:0px;
  width: 100%;
  height: 100%;
  background: black;
  opacity: .5;
  z-index: 999999;
}

app.component.ts

height = 0;
width = 0;
constructor(
    private message: MessagingService
  }
ngOnInit() {
    this.height = document.body.clientHeight;
    this.width = document.body.clientWidth;
  }

messaging.service.ts

import { Injectable } from '@angular/core';
import { Subject } from 'rxjs';

@Injectable({
    providedIn: 'root',
  })
export class MessagingService {
    // Observable string sources
  private plzWaitObservable = new Subject<boolean>();


  // Public Observables you subscribe to
  public plzWait$ = this.plzWaitObservable.asObservable();

  public plzWait = (wait: boolean) => this.plzWaitObservable.next(wait);
}

Some other component

constructor(private message: MessagingService) { }
somefunction() {
    this.message.plzWait(true);
    setTimeout(() => {
            this.message.plzWait(false);
    }, 5000);
}

How to send Request payload to REST API in java?

The following code works for me.

//escape the double quotes in json string
String payload="{\"jsonrpc\":\"2.0\",\"method\":\"changeDetail\",\"params\":[{\"id\":11376}],\"id\":2}";
String requestUrl="https://git.eclipse.org/r/gerrit/rpc/ChangeDetailService";
sendPostRequest(requestUrl, payload);

method implementation:

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

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

}

sql query distinct with Row_Number

Try this

SELECT distinct id
FROM  (SELECT id, ROW_NUMBER() OVER (ORDER BY  id) AS RowNum
      FROM table
      WHERE fid = 64) t

Or use RANK() instead of row number and select records DISTINCT rank

SELECT id
FROM  (SELECT id, ROW_NUMBER() OVER (PARTITION BY  id ORDER BY  id) AS RowNum
      FROM table
      WHERE fid = 64) t
WHERE t.RowNum=1

This also returns the distinct ids

Prefer composition over inheritance?

Aside from is a/has a considerations, one must also consider the "depth" of inheritance your object has to go through. Anything beyond five or six levels of inheritance deep might cause unexpected casting and boxing/unboxing problems, and in those cases it might be wise to compose your object instead.

How to detect the physical connected state of a network cable/connector?

You can use ethtool:

$ sudo ethtool eth0
Settings for eth0:
    Supported ports: [ TP ]
    Supported link modes:   10baseT/Half 10baseT/Full
                            100baseT/Half 100baseT/Full
                            1000baseT/Full
    Supports auto-negotiation: Yes
    Advertised link modes:  10baseT/Half 10baseT/Full
                            100baseT/Half 100baseT/Full
                            1000baseT/Full
    Advertised auto-negotiation: Yes
    Speed: 1000Mb/s
    Duplex: Full
    Port: Twisted Pair
    PHYAD: 0
    Transceiver: internal
    Auto-negotiation: on
    Supports Wake-on: umbg
    Wake-on: g
    Current message level: 0x00000007 (7)
    Link detected: yes

To only get the Link status you can use grep:

$ sudo ethtool eth0 | grep Link
    Link detected: yes

SELECT where row value contains string MySQL

SELECT * FROM Accounts WHERE Username LIKE '%$query%'

but it's not suggested. use PDO

unary operator expected in shell script when comparing null value with string

Why all people want to use '==' instead of simple '=' ? It is bad habit! It used only in [[ ]] expression. And in (( )) too. But you may use just = too! It work well in any case. If you use numbers, not strings use not parcing to strings and then compare like strings but compare numbers. like that

let -i i=5 # garantee that i is nubmber
test $i -eq 5 && echo "$i is equal 5" || echo "$i not equal 5"

It's match better and quicker. I'm expert in C/C++, Java, JavaScript. But if I use bash i never use '==' instead '='. Why you do so?

How to export data from Spark SQL to CSV

Since Spark 2.X spark-csv is integrated as native datasource. Therefore, the necessary statement simplifies to (windows)

df.write
  .option("header", "true")
  .csv("file:///C:/out.csv")

or UNIX

df.write
  .option("header", "true")
  .csv("/var/out.csv")

Notice: as the comments say, it is creating the directory by that name with the partitions in it, not a standard CSV file. This, however, is most likely what you want since otherwise your either crashing your driver (out of RAM) or you could be working with a non distributed environment.

Fatal error: Please read "Security" section of the manual to find out how to run mysqld as root

The correct answer that worked for me on CentOS is

/etc/init.d/mysql restart

which is an init script and not /etc/init.d/mysqld restart, which is binary

The is in fact comment of @MrTux on the question which worked for me. It took quite a bit of my time hence posting it as answer.

Deserialize JSON with Jackson into Polymorphic Types - A Complete Example is giving me a compile error

As promised, I'm putting an example for how to use annotations to serialize/deserialize polymorphic objects, I based this example in the Animal class from the tutorial you were reading.

First of all your Animal class with the Json Annotations for the subclasses.

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonSubTypes;
import com.fasterxml.jackson.annotation.JsonTypeInfo;

@JsonIgnoreProperties(ignoreUnknown = true)
@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY)
@JsonSubTypes({
    @JsonSubTypes.Type(value = Dog.class, name = "Dog"),

    @JsonSubTypes.Type(value = Cat.class, name = "Cat") }
)
public abstract class Animal {

    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

}

Then your subclasses, Dog and Cat.

public class Dog extends Animal {

    private String breed;

    public Dog() {

    }

    public Dog(String name, String breed) {
        setName(name);
        setBreed(breed);
    }

    public String getBreed() {
        return breed;
    }

    public void setBreed(String breed) {
        this.breed = breed;
    }
}

public class Cat extends Animal {

    public String getFavoriteToy() {
        return favoriteToy;
    }

    public Cat() {}

    public Cat(String name, String favoriteToy) {
        setName(name);
        setFavoriteToy(favoriteToy);
    }

    public void setFavoriteToy(String favoriteToy) {
        this.favoriteToy = favoriteToy;
    }

    private String favoriteToy;

}

As you can see, there is nothing special for Cat and Dog, the only one that know about them is the abstract class Animal, so when deserializing, you'll target to Animal and the ObjectMapper will return the actual instance as you can see in the following test:

public class Test {

    public static void main(String[] args) {

        ObjectMapper objectMapper = new ObjectMapper();

        Animal myDog = new Dog("ruffus","english shepherd");

        Animal myCat = new Cat("goya", "mice");

        try {
            String dogJson = objectMapper.writeValueAsString(myDog);

            System.out.println(dogJson);

            Animal deserializedDog = objectMapper.readValue(dogJson, Animal.class);

            System.out.println("Deserialized dogJson Class: " + deserializedDog.getClass().getSimpleName());

            String catJson = objectMapper.writeValueAsString(myCat);

            Animal deseriliazedCat = objectMapper.readValue(catJson, Animal.class);

            System.out.println("Deserialized catJson Class: " + deseriliazedCat.getClass().getSimpleName());



        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}

Output after running the Test class:

{"@type":"Dog","name":"ruffus","breed":"english shepherd"}

Deserialized dogJson Class: Dog

{"@type":"Cat","name":"goya","favoriteToy":"mice"}

Deserialized catJson Class: Cat

Hope this helps,

Jose Luis

Calculating the position of points in a circle

Here is an R version based on the @Pirijan answer above.

points <- 8
radius <- 10
center_x <- 5
center_y <- 5

drawCirclePoints <- function(points, radius, center_x, center_y) {
  slice <- 2 * pi / points
  angle <- slice * seq(0, points, by = 1)

  newX <- center_x + radius * cos(angle)
  newY <- center_y + radius * sin(angle)

  plot(newX, newY)
}

drawCirclePoints(points, radius, center_x, center_y)

How to run a cron job inside a docker container?

this line was the one that helped me run my pre-scheduled task.

ADD mycron/root /etc/cron.d/root

RUN chmod 0644 /etc/cron.d/root

RUN crontab /etc/cron.d/root

RUN touch /var/log/cron.log

CMD ( cron -f -l 8 & ) && apache2-foreground # <-- run cron

--> My project run inside: FROM php:7.2-apache

Display Adobe pdf inside a div

I don't think you can. You may need to use an Iframe instead.

Extract date (yyyy/mm/dd) from a timestamp in PostgreSQL

CREATE TABLE sometable (t TIMESTAMP, d DATE);
INSERT INTO sometable SELECT '2011/05/26 09:00:00';
UPDATE sometable SET d = t; -- OK
-- UPDATE sometable SET d = t::date; OK
-- UPDATE sometable SET d = CAST (t AS date); OK
-- UPDATE sometable SET d = date(t); OK
SELECT * FROM sometable ;
          t          |     d      
---------------------+------------
 2011-05-26 09:00:00 | 2011-05-26
(1 row)

Another test kit:

SELECT pg_catalog.date(t) FROM sometable;
    date    
------------
 2011-05-26
(1 row)

SHOW datestyle ;
 DateStyle 
-----------
 ISO, MDY
(1 row)

Pandas index column title or name

Use df.index.rename('foo', inplace=True) to set the index name.

Seems this api is available since pandas 0.13.

How do I fix the Visual Studio compile error, "mismatch between processor architecture"?

A good rule of thumb is "open DLLs, closed EXEs", that is:

  • EXE targets the OS, by specifying x86 or x64.
  • DLLs are left open (i.e., AnyCPU) so they can be instantiated within a 32-bit or a 64-bit process.

When you build an EXE as AnyCPU, all you're doing is deferring the decision on what process bitness to use to the OS, which will JIT the EXE to its liking. That is, an x64 OS will create a 64-bit process, an x86 OS will create an 32-bit process.

Building DLLs as AnyCPU makes them compatible to either process.

For more on the subtleties of assembly loading, see here. The executive summary reads something like:

  • AnyCPU – loads as x64 or x86 assembly, depending on the invoking process
  • x86 – loads as x86 assembly; will not load from an x64 process
  • x64 – loads as x64 assembly; will not load from an x86 process

Implement a simple factory pattern with Spring 3 annotations

Following the answer from DruidKuma and jumping_monkey

You can also include optional and make your code a bit nicer and cleaner:

 public static MyService getService(String type) {
        return Optional.ofNullable(myServiceCache.get(type))
                .orElseThrow(() -> new RuntimeException("Unknown service type: " + type));
 }

How do you get the current project directory from C# code when creating a custom MSBuild task?

If a project is running on an IIS express, the Environment.CurrentDirectory could point to where IIS Express is located ( the default path would be C:\Program Files (x86)\IIS Express ), not to where your project resides.


This is probably the most suitable directory path for various kinds of projects.

AppDomain.CurrentDomain.BaseDirectory

This is the MSDN definition.

Gets the base directory that the assembly resolver uses to probe for assemblies.

Cross-reference (named anchor) in markdown

Take me to [pookie](#pookie)

should be the correct markdown syntax to jump to the anchor point named pookie.

To insert an anchor point of that name use HTML:

<a name="pookie"></a>

Markdown doesn't seem to mind where you put the anchor point. A useful place to put it is in a header. For example:

### <a name="tith"></a>This is the Heading

works very well. (I'd demonstrate here but SO's renderer strips out the anchor.)

Note on self-closing tags and id= versus name=

An earlier version of this post suggested using <a id='tith' />, using the self-closing syntax for XHTML, and using the id attribute instead of name.

XHTML allows for any tag to be 'empty' and 'self-closed'. That is, <tag /> is short-hand for <tag></tag>, a matched pair of tags with an empty body. Most browsers will accept XHTML, but some do not. To avoid cross-browser problems, close the tag explicitly using <tag></tag>, as recommended above.

Finally, the attribute name= was deprecated in XHTML, so I originally used id=, which everyone recognises. However, HTML5 now creates a global variable in JavaScript when using id=, and this may not necessarily be what you want. So, using name= is now likely to be more friendly.

(Thanks to Slipp Douglas for explaining XHTML to me, and nailer for pointing out the HTML5 side-effect — see the comments and nailer's answer for more detail. name= appears to work everywhere, though it is deprecated in XHTML.)

Array of PHP Objects

The best place to find answers to general (and somewhat easy questions) such as this is to read up on PHP docs. Specifically in your case you can read more on objects. You can store stdObject and instantiated objects within an array. In fact, there is a process known as 'hydration' which populates the member variables of an object with values from a database row, then the object is stored in an array (possibly with other objects) and returned to the calling code for access.

-- Edit --

class Car
{
    public $color;
    public $type;
}

$myCar = new Car();
$myCar->color = 'red';
$myCar->type = 'sedan';

$yourCar = new Car();
$yourCar->color = 'blue';
$yourCar->type = 'suv';

$cars = array($myCar, $yourCar);

foreach ($cars as $car) {
    echo 'This car is a ' . $car->color . ' ' . $car->type . "\n";
}

Android: how to create Switch case from this?

switch(position) {
  case 0:
    ...
    break;
  case 1:
    ...
    break;
  default:
    ...

}

Did you mean that?

Print the contents of a DIV

Although @BC answer was the best to print a single page.

But To print multiple pages of A4 size at same time with ctrl+P following solution may help.

@media print{
html *{
    height:0px!important;
    width:0px !important;
    margin: 0px !important;
    padding: 0px !important;
    min-height: 0px !important;
    line-height: 0px !important;
    overflow: visible !important;
    visibility: hidden ;


}


/*assing myPagesClass to every div you want to print on single separate A4 page*/

 body .myPagesClass {
    z-index: 100 !important;
    visibility: visible !important;
    position: relative !important;
    display: block !important;
    background-color: lightgray !important;
    height: 297mm !important;
    width: 211mm !important;
    position: relative !important;

    padding: 0px;
    top: 0 !important;
    left: 0 !important;
    margin: 0 !important;
    orphans: 0!important;
    widows: 0!important;
    overflow: visible !important;
    page-break-after: always;

}
@page{
    size: A4;
    margin: 0mm ;
    orphans: 0!important;
    widows: 0!important;
}}

How do you close/hide the Android soft keyboard using Java?

When you want to hide keyboard manually on the action of button click:

/**
 * Hides the already popped up keyboard from the screen.
 *
 */
public void hideKeyboard() {
    try {
        // use application level context to avoid unnecessary leaks.
        InputMethodManager inputManager = (InputMethodManager) getApplicationContext().getSystemService(Context.INPUT_METHOD_SERVICE);
        assert inputManager != null;
        inputManager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

When you want to hide keyboard where ever you click on screen except edittext Override this method in your activity:

@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
    View view = getCurrentFocus();
    if (view != null && (ev.getAction() == MotionEvent.ACTION_UP || ev.getAction() == MotionEvent.ACTION_MOVE) && view instanceof EditText && !view.getClass().getName().startsWith("android.webkit.")) {
        int scrcoords[] = new int[2];
        view.getLocationOnScreen(scrcoords);
        float x = ev.getRawX() + view.getLeft() - scrcoords[0];
        float y = ev.getRawY() + view.getTop() - scrcoords[1];
        if (x < view.getLeft() || x > view.getRight() || y < view.getTop() || y > view.getBottom())
            ((InputMethodManager)this.getSystemService(Context.INPUT_METHOD_SERVICE)).hideSoftInputFromWindow((this.getWindow().getDecorView().getApplicationWindowToken()), 0);
    }
    return super.dispatchTouchEvent(ev);
}

Default session timeout for Apache Tomcat applications

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

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

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

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

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

How can I strip all punctuation from a string in JavaScript using regex?

/[^A-Za-z0-9\s]/g should match all punctuation but keep the spaces. So you can use .replace(/\s{2,}/g, " ") to replace extra spaces if you need to do so. You can test the regex in http://rubular.com/

.replace(/[^A-Za-z0-9\s]/g,"").replace(/\s{2,}/g, " ")

Update: Will only work if the input is ANSI English.

Most recent previous business day in Python

timeboard package does this.

Suppose your date is 04 Sep 2017. In spite of being a Monday, it was a holiday in the US (the Labor Day). So, the most recent business day was Friday, Sep 1.

>>> import timeboard.calendars.US as US
>>> clnd = US.Weekly8x5()
>>> clnd('04 Sep 2017').rollback().to_timestamp().date()
datetime.date(2017, 9, 1)

In UK, 04 Sep 2017 was the regular business day, so the most recent business day was itself.

>>> import timeboard.calendars.UK as UK
>>> clnd = UK.Weekly8x5()
>>> clnd('04 Sep 2017').rollback().to_timestamp().date()
datetime.date(2017, 9, 4)

DISCLAIMER: I am the author of timeboard.

Numbering rows within groups in a data frame

I would like to add a data.table variant using the rank() function which provides the additional possibility to change the ordering and thus makes it a bit more flexible than the seq_len() solution and is pretty similar to row_number functions in RDBMS.

# Variant with ascending ordering
library(data.table)
dt <- data.table(df)
dt[, .( val
   , num = rank(val))
    , by = list(cat)][order(cat, num),]

    cat        val num
 1: aaa 0.05638315   1
 2: aaa 0.25767250   2
 3: aaa 0.30776611   3
 4: aaa 0.46854928   4
 5: aaa 0.55232243   5
 6: bbb 0.17026205   1
 7: bbb 0.37032054   2
 8: bbb 0.48377074   3
 9: bbb 0.54655860   4
10: bbb 0.81240262   5
11: ccc 0.28035384   1
12: ccc 0.39848790   2
13: ccc 0.62499648   3
14: ccc 0.76255108   4

# Variant with descending ordering
dt[, .( val
   , num = rank(-val))
    , by = list(cat)][order(cat, num),]

how to check if List<T> element contains an item with a Particular Property Value

This is pretty easy to do using LINQ:

var match = pricePublicList.FirstOrDefault(p => p.Size == 200);
if (match == null)
{
    // Element doesn't exist
}

Execute stored procedure with an Output parameter?

CREATE PROCEDURE DBO.MY_STORED_PROCEDURE
(@PARAM1VALUE INT,
@PARAM2VALUE INT,
@OUTPARAM VARCHAR(20) OUT)
AS 
BEGIN
SELECT * FROM DBO.PARAMTABLENAME WHERE PARAM1VALUE=@PARAM1VALUE
END

DECLARE @OUTPARAM2 VARCHAR(20)
EXEC DBO.MY_STORED_PROCEDURE 1,@OUTPARAM2 OUT
PRINT @OUTPARAM2

How do I find out if a column exists in a VB.Net DataRow

DataRow's are nice in the way that they have their underlying table linked to them. With the underlying table you can verify that a specific row has a specific column in it.

    If DataRow.Table.Columns.Contains("column") Then
        MsgBox("YAY")
    End If

C# equivalent of C++ map<string,double>

This code is all you need:

   static void Main(string[] args) {
        String xml = @"
            <transactions>
                <transaction name=""Fred"" amount=""5,20"" />
                <transaction name=""John"" amount=""10,00"" />
                <transaction name=""Fred"" amount=""3,00"" />
            </transactions>";

        XDocument xmlDocument = XDocument.Parse(xml);

        var query = from x in xmlDocument.Descendants("transaction")
                    group x by x.Attribute("name").Value into g
                    select new { Name = g.Key, Amount = g.Sum(t => Decimal.Parse(t.Attribute("amount").Value)) };

        foreach (var item in query) {
            Console.WriteLine("Name: {0}; Amount: {1:C};", item.Name, item.Amount);
        }
    }

And the content is:

Name: Fred; Amount: R$ 8,20;
Name: John; Amount: R$ 10,00;

That is the way of doing this in C# - in a declarative way!

I hope this helps,

Ricardo Lacerda Castelo Branco

jQuery: Check if special characters exists in string

var specialChars = "<>@!#$%^&*()_+[]{}?:;|'\"\\,./~`-="
var check = function(string){
    for(i = 0; i < specialChars.length;i++){
        if(string.indexOf(specialChars[i]) > -1){
            return true
        }
    }
    return false;
}

if(check($('#Search').val()) == false){
    // Code that needs to execute when none of the above is in the string
}else{
    alert('Your search string contains illegal characters.');
}

Select Multiple Fields from List in Linq

(from i in list
 select new { i.category_id, i.category_name })
 .Distinct()
 .OrderBy(i => i.category_name);

How to execute a command prompt command from python

Try adding a call to proc.stdin.flush() after writing to the pipe and see if things start behaving more as you expect. Explicitly flushing the pipe means you don't need to worry about exactly how the buffering is set up.

Also, don't forget to include a "\n" at the end of your command or your child shell will sit there at the prompt waiting for completion of the command entry.

I wrote about using Popen to manipulate an external shell instance in more detail at: Running three commands in the same process with Python

As was the case in that question, this trick can be valuable if you need to maintain shell state across multiple out-of-process invocations on a Windows machine.

Excel VBA Run Time Error '424' object required

Simply remove the .value from your code.

Set envFrmwrkPath = ActiveSheet.Range("D6").Value

instead of this, use:

Set envFrmwrkPath = ActiveSheet.Range("D6")

retrieve data from db and display it in table in php .. see this code whats wrong with it?

Here is the solution total html with php and database connections

   <!doctype html>
    <html lang="en">
    <head>
      <meta charset="UTF-8">
      <title>database connections</title>
    </head>
    <body>
      <?php
      $username = "database-username";
      $password = "database-password";
      $host = "localhost";

      $connector = mysql_connect($host,$username,$password)
          or die("Unable to connect");
        echo "Connections are made successfully::";
      $selected = mysql_select_db("test_db", $connector)
        or die("Unable to connect");

      //execute the SQL query and return records
      $result = mysql_query("SELECT * FROM table_one ");
      ?>
      <table border="2" style= "background-color: #84ed86; color: #761a9b; margin: 0 auto;" >
      <thead>
        <tr>
          <th>Employee_id</th>
          <th>Employee_Name</th>
          <th>Employee_dob</th>
          <th>Employee_Adress</th>
          <th>Employee_dept</th>
          <td>Employee_salary</td>
        </tr>
      </thead>
      <tbody>
        <?php
          while( $row = mysql_fetch_assoc( $result ) ){
            echo
            "<tr>
              <td>{$row\['employee_id'\]}</td>
              <td>{$row\['employee_name'\]}</td>
              <td>{$row\['employee_dob'\]}</td>
              <td>{$row\['employee_addr'\]}</td>
              <td>{$row\['employee_dept'\]}</td>
              <td>{$row\['employee_sal'\]}</td> 
            </tr>\n";
          }
        ?>
      </tbody>
    </table>
     <?php mysql_close($connector); ?>
    </body>
    </html>

C: scanf to array

Use

scanf("%d", &array[0]);

and use == for comparision instead of =

Binning column with python pandas

Using numba module for speed up.

On big datasets (500k >) pd.cut can be quite slow for binning data.

I wrote my own function in numba with just in time compilation, which is roughly 16x faster:

from numba import njit

@njit
def cut(arr):
    bins = np.empty(arr.shape[0])
    for idx, x in enumerate(arr):
        if (x >= 0) & (x < 1):
            bins[idx] = 1
        elif (x >= 1) & (x < 5):
            bins[idx] = 2
        elif (x >= 5) & (x < 10):
            bins[idx] = 3
        elif (x >= 10) & (x < 25):
            bins[idx] = 4
        elif (x >= 25) & (x < 50):
            bins[idx] = 5
        elif (x >= 50) & (x < 100):
            bins[idx] = 6
        else:
            bins[idx] = 7

    return bins
cut(df['percentage'].to_numpy())

# array([5., 5., 7., 5.])

Optional: you can also map it to bins as strings:

a = cut(df['percentage'].to_numpy())

conversion_dict = {1: 'bin1',
                   2: 'bin2',
                   3: 'bin3',
                   4: 'bin4',
                   5: 'bin5',
                   6: 'bin6',
                   7: 'bin7'}

bins = list(map(conversion_dict.get, a))

# ['bin5', 'bin5', 'bin7', 'bin5']

Speed comparison:

# create dataframe of 8 million rows for testing
dfbig = pd.concat([df]*2000000, ignore_index=True)

dfbig.shape

# (8000000, 1)
%%timeit
cut(dfbig['percentage'].to_numpy())

# 38 ms ± 616 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)
%%timeit
bins = [0, 1, 5, 10, 25, 50, 100]
labels = [1,2,3,4,5,6]
pd.cut(dfbig['percentage'], bins=bins, labels=labels)

# 215 ms ± 9.76 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)

How do I spool to a CSV formatted file using SQLPLUS?

There is a problem using sqlplus to create csv files. If you want the column headers only once in the output and there are thousands or millions of rows, you cannot set pagesize large enough not to get a repeat. The solution is to start with pagesize = 50 and parse out the headers, then issue the select again with pagesize = 0 to get the data. See bash script below:

#!/bin/bash
FOLDER="csvdata_mydb"
CONN="192.168.100.11:1521/mydb0023.world"
CNT=0376
ORD="0376"
TABLE="MY_ATTACHMENTS"

sqlplus -L logn/pswd@//${CONN}<<EOF >/dev/null
set pagesize 50;
set verify off;
set feedback off;
set long 99999;
set linesize 32767;
set trimspool on;
col object_ddl format A32000;
set colsep ,;
set underline off;
set headsep off;
spool ${ORD}${TABLE}.tmp;
select * from tblspc.${TABLE} where rownum < 2;
EOF
LINES=`wc -l ${ORD}${TABLE}.tmp | cut -f1 -d" "`
[ ${LINES} -le 3 ] && {
  echo "No Data Found in ${TABLE}."
}
[ ${LINES} -gt 3 ] && {
  cat ${ORD}${TABLE}.tmp | sed -e 's/ * / /g' -e 's/^ //' -e 's/ ,/,/g' -e 's/, /,/g' | tail -n +3 | head -n 1 > ./${ORD}${TABLE}.headers
}

sqlplus -L logn/pswd@//${CONN}<<EOF >/dev/null
set pagesize 0;
set verify off;
set feedback off;
set long 99999;
set linesize 32767;
set trimspool on;
col object_ddl format A32000;
set colsep ,;
set underline off;
set headsep off;
spool ${ORD}${TABLE}.tmp;
select * from tblspc.${TABLE};
EOF
LINES=`wc -l ${ORD}${TABLE}.tmp | cut -f1 -d" "`
[ ${LINES} -le 3 ] && {
  echo "No Data Found in ${TABLE}."
}
[ ${LINES} -gt 3 ] && {
  cat ${ORD}${TABLE}.headers > ${FOLDER}/${ORD}${TABLE}.csv
  cat ${ORD}${TABLE}.tmp | sed -e 's/ * / /g' -e 's/^ //' -e 's/ ,/,/g' -e 's/, /,/g' | tail -n +2 | head -n -1 >> ${FOLDER}/${ORD}${TABLE}.csv
}

Creating an XmlNode/XmlElement in C# without an XmlDocument?

Create a new XmlDocument with the contents you want and then import it into your existing document, by accessing the OwnerDocument property of your existing nodes:

XmlNode existing_node; // of some document, where we don't know necessarily know the XmlDocument...
XmlDocument temp = new XmlDocument();
temp.LoadXml("<new><elements/></new>");
XmlNode new_node = existing_node.OwnerDocument.ImportNode(temp.DocumentElement, true);
existing_node.AppendChild(new_node);

Good luck.

WPF C# button style

To solve your question definitely need to use the Style and Template for the Button. But how exactly does he look like? Decisions may be several. For example, Button are two texts to better define the relevant TextBlocks? Can be directly in the template, but then use the buttons will be limited, because the template can be only one ContentPresenter. I decided to do things differently, to identify one ContentPresenter with an icon in the form of a Path, and the content is set using the buttons on the side.

The style:

<Style TargetType="{x:Type Button}">
    <Setter Property="Background" Value="#373737" />
    <Setter Property="Foreground" Value="White" />
    <Setter Property="FontSize" Value="15" />
    <Setter Property="SnapsToDevicePixels" Value="True" />

    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Button}">
                <Border CornerRadius="4" Background="{TemplateBinding Background}">
                    <Grid>
                        <Path x:Name="PathIcon" Width="15" Height="25" Stretch="Fill" Fill="#4C87B3" HorizontalAlignment="Left" Margin="17,0,0,0" Data="F1 M 30.0833,22.1667L 50.6665,37.6043L 50.6665,38.7918L 30.0833,53.8333L 30.0833,22.1667 Z "/>
                        <ContentPresenter x:Name="MyContentPresenter" Content="{TemplateBinding Content}" HorizontalAlignment="Center" VerticalAlignment="Center" Margin="0,0,0,0" />                                
                    </Grid>
                </Border>

                <ControlTemplate.Triggers>
                    <Trigger Property="IsMouseOver" Value="True">
                        <Setter Property="Background" Value="#E59400" />
                        <Setter Property="Foreground" Value="White" />
                        <Setter TargetName="PathIcon" Property="Fill" Value="Black" />
                    </Trigger>

                    <Trigger Property="IsPressed" Value="True">
                        <Setter Property="Background" Value="OrangeRed" />
                        <Setter Property="Foreground" Value="White" />
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

Sample of using:

<Button Width="200" Height="50" VerticalAlignment="Top" Margin="0,20,0,0" />
    <Button.Content>
        <StackPanel>
            <TextBlock Text="Watch Now" FontSize="20" />
            <TextBlock Text="Duration: 50m" FontSize="12" Foreground="Gainsboro" />
        </StackPanel>
    </Button.Content>
</Button>

Output

enter image description here

It is best to StackPanel determine the Resources and set the Button so:

<Window.Resources>
    <StackPanel x:Key="MyStackPanel">
        <TextBlock Name="MainContent" Text="Watch Now" FontSize="20" />
        <TextBlock Name="DurationValue" Text="Duration: 50m" FontSize="12" Foreground="Gainsboro" />
    </StackPanel>
</Window.Resources>

<Button Width="200" Height="50" Content="{StaticResource MyStackPanel}" VerticalAlignment="Top" Margin="0,20,0,0" />

The question remains with setting the value for TextBlock Duration, because this value must be dynamic. I implemented it using attached DependencyProperty. Set it to the window, like that:

<Window Name="MyWindow" local:MyDependencyClass.CurrentDuration="Duration: 50m" ... />

Using in TextBlock:

<TextBlock Name="DurationValue" Text="{Binding ElementName=MyWindow, Path=(local:MyDependencyClass.CurrentDuration)}" FontSize="12" Foreground="Gainsboro" />

In fact, there is no difference for anyone to determine the attached DependencyProperty, because it is the predominant feature.

Example of set value:

private void Button_Click(object sender, RoutedEventArgs e)
{
    MyDependencyClass.SetCurrentDuration(MyWindow, "Duration: 101m");
}

A complete listing of examples:

XAML

<Window x:Class="ButtonHelp.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:ButtonHelp"
    Name="MyWindow"
    Title="MainWindow" Height="350" Width="525"
    WindowStartupLocation="CenterScreen"
    local:MyDependencyClass.CurrentDuration="Duration: 50m">

<Window.Resources>
    <Style TargetType="{x:Type Button}">
        <Setter Property="Background" Value="#373737" />
        <Setter Property="Foreground" Value="White" />
        <Setter Property="FontSize" Value="15" />
        <Setter Property="FontFamily" Value="./#Segoe UI" />
        <Setter Property="SnapsToDevicePixels" Value="True" />

        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type Button}">
                    <Border CornerRadius="4" Background="{TemplateBinding Background}">
                        <Grid>
                            <Path x:Name="PathIcon" Width="15" Height="25" Stretch="Fill" Fill="#4C87B3" HorizontalAlignment="Left" Margin="17,0,0,0" Data="F1 M 30.0833,22.1667L 50.6665,37.6043L 50.6665,38.7918L 30.0833,53.8333L 30.0833,22.1667 Z "/>
                            <ContentPresenter x:Name="MyContentPresenter" Content="{TemplateBinding Content}" HorizontalAlignment="Center" VerticalAlignment="Center" Margin="0,0,0,0" />                                
                        </Grid>
                    </Border>

                    <ControlTemplate.Triggers>
                        <Trigger Property="IsMouseOver" Value="True">
                            <Setter Property="Background" Value="#E59400" />
                            <Setter Property="Foreground" Value="White" />
                            <Setter TargetName="PathIcon" Property="Fill" Value="Black" />
                        </Trigger>

                        <Trigger Property="IsPressed" Value="True">
                            <Setter Property="Background" Value="OrangeRed" />
                            <Setter Property="Foreground" Value="White" />
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

    <StackPanel x:Key="MyStackPanel">
        <TextBlock Name="MainContent" Text="Watch Now" FontSize="20" />
        <TextBlock Name="DurationValue" Text="{Binding ElementName=MyWindow, Path=(local:MyDependencyClass.CurrentDuration)}" FontSize="12" Foreground="Gainsboro" />
    </StackPanel>
</Window.Resources>

<Grid>        
    <Button Width="200" Height="50" Content="{StaticResource MyStackPanel}" VerticalAlignment="Top" Margin="0,20,0,0" />

    <Button Content="Set some duration" Style="{x:Null}" Width="140" Height="30" VerticalAlignment="Top" HorizontalAlignment="Left" Click="Button_Click" />
</Grid>

Code behind

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        MyDependencyClass.SetCurrentDuration(MyWindow, "Duration: 101m");
    }
}

public class MyDependencyClass : DependencyObject
{
    public static readonly DependencyProperty CurrentDurationProperty;        

    public static void SetCurrentDuration(DependencyObject DepObject, string value)
    {
        DepObject.SetValue(CurrentDurationProperty, value);
    }

    public static string GetCurrentDuration(DependencyObject DepObject)
    {
        return (string)DepObject.GetValue(CurrentDurationProperty);
    }

    static MyDependencyClass()
    {
        PropertyMetadata MyPropertyMetadata = new PropertyMetadata("Duration: 0m");

        CurrentDurationProperty = DependencyProperty.RegisterAttached("CurrentDuration",
                                                            typeof(string),
                                                            typeof(MyDependencyClass),
                                                            MyPropertyMetadata);
    }
}

Java Could not reserve enough space for object heap error

4gb RAM doesn't mean you can use it all for java process. Lots of RAM is needed for system processes. Dont go above 2GB or it will be trouble some.

Before starting jvm just check how much RAM is available and then set memory accordingly.

How to kill a child process after a given timeout in Bash?

I also had this question and found two more things very useful:

  1. The SECONDS variable in bash.
  2. The command "pgrep".

So I use something like this on the command line (OSX 10.9):

ping www.goooooogle.com & PING_PID=$(pgrep 'ping'); SECONDS=0; while pgrep -q 'ping'; do sleep 0.2; if [ $SECONDS = 10 ]; then kill $PING_PID; fi; done

As this is a loop I included a "sleep 0.2" to keep the CPU cool. ;-)

(BTW: ping is a bad example anyway, you just would use the built-in "-t" (timeout) option.)

Single Line Nested For Loops

First of all, your first code doesn't use a for loop per se, but a list comprehension.

  1. Would be equivalent to

    for j in range(0, width): for i in range(0, height): m[i][j]

  2. Much the same way, it generally nests like for loops, right to left. But list comprehension syntax is more complex.

  3. I'm not sure what this question is asking


  1. Any iterable object that yields iterable objects that yield exactly two objects (what a mouthful - i.e [(1,2),'ab'] would be valid )

  2. The order in which the object yields upon iteration. i goes to the first yield, j the second.

  3. Yes, but not as pretty. I believe it is functionally equivalent to:

    l = list()
    for i,j in object:
        l.append(function(i,j))
    

    or even better use map:

    map(function, object)
    

    But of course function would have to get i, j itself.

  4. Isn't this the same question as 3?

Print string and variable contents on the same line in R

As other users said, cat() is probably the best option.

@krlmlr suggested using sprintf() and it's currently the third ranked answer. sprintf() is not a good idea. From R documentation:

The format string is passed down the OS's sprintf function, and incorrect formats can cause the latter to crash the R process.

There is no good reason to use sprintf() over cat or other options.

SQL Server 2008 - Case / If statements in SELECT Clause

Simple CASE expression:

CASE input_expression 
     WHEN when_expression THEN result_expression [ ...n ] 
     [ ELSE else_result_expression ] 
END

Searched CASE expression:

CASE
     WHEN Boolean_expression THEN result_expression [ ...n ] 
     [ ELSE else_result_expression ] 
END

Reference: http://msdn.microsoft.com/en-us/library/ms181765.aspx

Rank function in MySQL

To avoid the "however" in Erandac's answer in combination of Daniel's and Salman's answers, one may use one of the following "partition workarounds"

SELECT customerID, myDate

  -- partition ranking works only with CTE / from MySQL 8.0 on
  , RANK() OVER (PARTITION BY customerID ORDER BY dateFrom) AS rank, 

  -- Erandac's method in combination of Daniel's and Salman's
  -- count all items in sequence, maximum reaches row count.
  , IF(customerID=@_lastRank, @_curRank:=@_curRank, @_curRank:=@_sequence+1) AS sequenceRank
  , @_sequence:=@_sequence+1 as sequenceOverAll

  -- Dense partition ranking, works also with MySQL 5.7
  -- remember to set offset values in from clause
  , IF(customerID=@_lastRank, @_nxtRank:=@_nxtRank, @_nxtRank:=@_nxtRank+1 ) AS partitionRank
  , IF(customerID=@_lastRank, @_overPart:=@_overPart+1, @_overPart:=1 ) AS partitionSequence

  , @_lastRank:=customerID
FROM myCustomers, 
  (SELECT @_curRank:=0, @_sequence:=0, @_lastRank:=0, @_nxtRank:=0, @_overPart:=0 ) r
ORDER BY customerID, myDate

The partition ranking in the 3rd variant in this code snippet will return continous ranking numbers. this will lead to a data structur similar to the rank() over partition by result. As an example, see below. In particular, the partitionSequence will always start with 1 for each new partitionRank, using this method:

customerID    myDate   sequenceRank (Erandac)
                          |    sequenceOverAll
                          |     |   partitionRank
                          |     |     | partitionSequence
                          |     |     |    | lastRank
... lines ommitted for clarity
40    09.11.2016 11:19    1     44    1   44    40
40    09.12.2016 12:08    1     45    1   45    40
40    09.12.2016 12:08    1     46    1   46    40
40    09.12.2016 12:11    1     47    1   47    40
40    09.12.2016 12:12    1     48    1   48    40
40    13.10.2017 16:31    1     49    1   49    40
40    15.10.2017 11:00    1     50    1   50    40
76    01.07.2015 00:24    51    51    2    1    76
77    04.08.2014 13:35    52    52    3    1    77
79    15.04.2015 20:25    53    53    4    1    79
79    24.04.2018 11:44    53    54    4    2    79
79    08.10.2018 17:37    53    55    4    3    79
117   09.07.2014 18:21    56    56    5    1   117
119   26.06.2014 13:55    57    57    6    1   119
119   02.03.2015 10:23    57    58    6    2   119
119   12.10.2015 10:16    57    59    6    3   119
119   08.04.2016 09:32    57    60    6    4   119
119   05.10.2016 12:41    57    61    6    5   119
119   05.10.2016 12:42    57    62    6    6   119
...

How to print environment variables to the console in PowerShell?

The following is works best in my opinion:

Get-Item Env:PATH
  1. It's shorter and therefore a little bit easier to remember than Get-ChildItem. There's no hierarchy with environment variables.
  2. The command is symmetrical to one of the ways that's used for setting environment variables with Powershell. (EX: Set-Item -Path env:SomeVariable -Value "Some Value")
  3. If you get in the habit of doing it this way you'll remember how to list all Environment variables; simply omit the entry portion. (EX: Get-Item Env:)

I found the syntax odd at first, but things started making more sense after I understood the notion of Providers. Essentially PowerShell let's you navigate disparate components of the system in a way that's analogous to a file system.

What's the point of the trailing colon in Env:? Try listing all of the "drives" available through Providers like this:

PS> Get-PSDrive

I only see a few results... (Alias, C, Cert, D, Env, Function, HKCU, HKLM, Variable, WSMan). It becomes obvious that Env is simply another "drive" and the colon is a familiar syntax to anyone who's worked in Windows.

You can navigate the drives and pick out specific values:

Get-ChildItem C:\Windows
Get-Item C:
Get-Item Env:
Get-Item HKLM:
Get-ChildItem HKLM:SYSTEM

Put byte array to JSON and vice versa

The typical way to send binary in json is to base64 encode it.

Java provides different ways to Base64 encode and decode a byte[]. One of these is DatatypeConverter.

Very simply

byte[] originalBytes = new byte[] { 1, 2, 3, 4, 5};
String base64Encoded = DatatypeConverter.printBase64Binary(originalBytes);
byte[] base64Decoded = DatatypeConverter.parseBase64Binary(base64Encoded);

You'll have to make this conversion depending on the json parser/generator library you use.

How to preview git-pull without doing fetch?

After doing a git fetch, do a git log HEAD..origin/master to show the log entries between your last common commit and the origin's master branch. To show the diffs, use either git log -p HEAD..origin/master to show each patch, or git diff HEAD...origin/master (three dots not two) to show a single diff.

There normally isn't any need to undo a fetch, because doing a fetch only updates the remote branches and none of your branches. If you're not prepared to do a pull and merge in all the remote commits, you can use git cherry-pick to accept only the specific remote commits you want. Later, when you're ready to get everything, a git pull will merge in the rest of the commits.

Update: I'm not entirely sure why you want to avoid the use of git fetch. All git fetch does is update your local copy of the remote branches. This local copy doesn't have anything to do with any of your branches, and it doesn't have anything to do with uncommitted local changes. I have heard of people who run git fetch in a cron job because it's so safe. (I wouldn't normally recommend doing that, though.)

`getchar()` gives the same output as the input string

In the simple setup you are likely using, getchar works with buffered input, so you have to press enter before getchar gets anything to read. Strings are not terminated by EOF; in fact, EOF is not really a character, but a magic value that indicates the end of the file. But EOF is not part of the string read. It's what getchar returns when there is nothing left to read.

&& (AND) and || (OR) in IF statements

Short circuit here means that the second condition won't be evaluated.

If ( A && B ) will result in short circuit if A is False.

If ( A && B ) will not result in short Circuit if A is True.

If ( A || B ) will result in short circuit if A is True.

If ( A || B ) will not result in short circuit if A is False.

Limiting the number of characters in a string, and chopping off the rest

Ideally you should try not to modify the internal data representation for the purpose of creating the table. Whats the problem with String.format()? It will return you new string with required width.

How do getters and setters work?

Tutorial is not really required for this. Read up on encapsulation

private String myField; //"private" means access to this is restricted

public String getMyField()
{
     //include validation, logic, logging or whatever you like here
    return this.myField;
}
public void setMyField(String value)
{
     //include more logic
     this.myField = value;
}

How do I tell what type of value is in a Perl variable?

I like polymorphism instead of manually checking for something:

use MooseX::Declare;

class Foo {
    use MooseX::MultiMethods;

    multi method foo (ArrayRef $arg){ say "arg is an array" }
    multi method foo (HashRef $arg) { say "arg is a hash" }
    multi method foo (Any $arg)     { say "arg is something else" }
}

Foo->new->foo([]); # arg is an array
Foo->new->foo(40); # arg is something else

This is much more powerful than manual checking, as you can reuse your "checks" like you would any other type constraint. That means when you want to handle arrays, hashes, and even numbers less than 42, you just write a constraint for "even numbers less than 42" and add a new multimethod for that case. The "calling code" is not affected.

Your type library:

package MyApp::Types;
use MooseX::Types -declare => ['EvenNumberLessThan42'];
use MooseX::Types::Moose qw(Num);

subtype EvenNumberLessThan42, as Num, where { $_ < 42 && $_ % 2 == 0 };

Then make Foo support this (in that class definition):

class Foo {
    use MyApp::Types qw(EvenNumberLessThan42);

    multi method foo (EvenNumberLessThan42 $arg) { say "arg is an even number less than 42" }
}

Then Foo->new->foo(40) prints arg is an even number less than 42 instead of arg is something else.

Maintainable.

Display an image with Python

import IPython.display as display
from PIL import Image
image_path = 'my_image.jpg'
display.display(Image.open(image_path))

Mongodb service won't start

In my case, it was also showing some lock problems whenever my local system shuts down without stopping the MongoDB server.

But it just worked only by using sudo command:-

$ sudo mongod --port 27017

Storing Images in PostgreSQL

Updating to 2012, when we see that image sizes, and number of images, are growing and growing, in all applications...

We need some distinction between "original image" and "processed image", like thumbnail.

As Jcoby's answer says, there are two options, then, I recommend:

  • use blob (Binary Large OBject): for original image store, at your table. See Ivan's answer (no problem with backing up blobs!), PostgreSQL additional supplied modules, How-tos etc.

  • use a separate database with DBlink: for original image store, at another (unified/specialized) database. In this case, I prefer bytea, but blob is near the same. Separating database is the best way for a "unified image webservice".

  • use bytea (BYTE Array): for caching thumbnail images. Cache the little images to send it fast to the web-browser (to avoiding rendering problems) and reduce server processing. Cache also essential metadata, like width and height. Database caching is the easiest way, but check your needs and server configs (ex. Apache modules): store thumbnails at file system may be better, compare performances. Remember that it is a (unified) web-service, then can be stored at a separate database (with no backups), serving many tables. See also PostgreSQL binary data types manual, tests with bytea column, etc.

NOTE1: today the use of "dual solutions" (database+filesystem) is deprecated (!). There are many advantages to using "only database" instead dual. PostgreSQL have comparable performance and good tools for export/import/input/output.

NOTE2: remember that PostgreSQL have only bytea, not have a default Oracle's BLOB: "The SQL standard defines (...) BLOB. The input format is different from bytea, but the provided functions and operators are mostly the same",Manual.


EDIT 2014: I have not changed the original text above today (my answer was Apr 22 '12, now with 14 votes), I am opening the answer for your changes (see "Wiki mode", you can edit!), for proofreading and for updates.
The question is stable (@Ivans's '08 answer with 19 votes), please, help to improve this text.

Angular JS break ForEach

You can use this:

var count = 0;
var arr = [0,1,2];
for(var i in arr){
   if(count == 1) break;
   //console.log(arr[i]);
}

Is it possible to use the instanceof operator in a switch statement?

You can't. The switch statement can only contain case statements which are compile time constants and which evaluate to an integer (Up to Java 6 and a string in Java 7).

What you are looking for is called "pattern matching" in functional programming.

See also Avoiding instanceof in Java

Accessing a value in a tuple that is in a list

A list comprehension is absolutely the way to do this. Another way that should be faster is map and itemgetter.

import operator

new_list = map(operator.itemgetter(1), old_list)

In response to the comment that the OP couldn't find an answer on google, I'll point out a super naive way to do it.

new_list = []
for item in old_list:
    new_list.append(item[1])

This uses:

  1. Declaring a variable to reference an empty list.
  2. A for loop.
  3. Calling the append method on a list.

If somebody is trying to learn a language and can't put together these basic pieces for themselves, then they need to view it as an exercise and do it themselves even if it takes twenty hours.

One needs to learn how to think about what one wants and compare that to the available tools. Every element in my second answer should be covered in a basic tutorial. You cannot learn to program without reading one.