Programs & Examples On #Pscp

PuTTY Secure Copy client (pscp) is a command-line SCP client for transferring files securely between computers using an SSH connection.

How can I copy a file from a remote server to using Putty in Windows?

It worked using PSCP. Instructions:

  1. Download PSCP.EXE from Putty download page
  2. Open command prompt and type set PATH=<path to the pscp.exe file>
  3. In command prompt point to the location of the pscp.exe using cd command
  4. Type pscp
  5. use the following command to copy file form remote server to the local system

    pscp [options] [user@]host:source target
    

So to copy the file /etc/hosts from the server example.com as user fred to the file c:\temp\example-hosts.txt, you would type:

pscp [email protected]:/etc/hosts c:\temp\example-hosts.txt

PHP Pass variable to next page

HTML / HTTP is stateless, in other words, what you did / saw on the previous page, is completely unconnected with the current page. Except if you use something like sessions, cookies or GET / POST variables. Sessions and cookies are quite easy to use, with session being by far more secure than cookies. More secure, but not completely secure.

Session:

//On page 1
$_SESSION['varname'] = $var_value;

//On page 2
$var_value = $_SESSION['varname'];

Remember to run the session_start(); statement on both these pages before you try to access the $_SESSION array, and also before any output is sent to the browser.

Cookie:

//One page 1
$_COOKIE['varname'] = $var_value;

//On page 2
$var_value = $_COOKIE['varname'];

The big difference between sessions and cookies is that the value of the variable will be stored on the server if you're using sessions, and on the client if you're using cookies. I can't think of any good reason to use cookies instead of sessions, except if you want data to persist between sessions, but even then it's perhaps better to store it in a DB, and retrieve it based on a username or id.

GET and POST

You can add the variable in the link to the next page:

<a href="page2.php?varname=<?php echo $var_value ?>">Page2</a>

This will create a GET variable.

Another way is to include a hidden field in a form that submits to page two:

<form method="get" action="page2.php">
    <input type="hidden" name="varname" value="var_value">
    <input type="submit">
</form>

And then on page two:

//Using GET
$var_value = $_GET['varname'];

//Using POST
$var_value = $_POST['varname'];

//Using GET, POST or COOKIE.
$var_value = $_REQUEST['varname'];

Just change the method for the form to post if you want to do it via post. Both are equally insecure, although GET is easier to hack.

The fact that each new request is, except for session data, a totally new instance of the script caught me when I first started coding in PHP. Once you get used to it, it's quite simple though.

A Simple, 2d cross-platform graphics library for c or c++?

What about SDL?

Perhaps it's a bit too complex for your needs, but it's certainly cross-platform.

Default fetch type for one-to-one, many-to-one and one-to-many in Hibernate

I know the answers were correct at the time of asking the question - but since people (like me this minute) still happen to find them wondering why their WildFly 10 was behaving differently, I'd like to give an update for the current Hibernate 5.x version:

In the Hibernate 5.2 User Guide it is stated in chapter 11.2. Applying fetch strategies:

The Hibernate recommendation is to statically mark all associations lazy and to use dynamic fetching strategies for eagerness. This is unfortunately at odds with the JPA specification which defines that all one-to-one and many-to-one associations should be eagerly fetched by default. Hibernate, as a JPA provider, honors that default.

So Hibernate as well behaves like Ashish Agarwal stated above for JPA:

OneToMany: LAZY
ManyToOne: EAGER
ManyToMany: LAZY
OneToOne: EAGER

(see JPA 2.1 Spec)

jQuery: using a variable as a selector

You're thinking too complicated. It's actually just $('#'+openaddress).

Assets file project.assets.json not found. Run a NuGet package restore

little late to the answer but seems this will add value. Looking at the error - it seems to occur in CI/CD pipeline.

Just running "dotnet build" will be sufficient enough.

dotnet build

dotnet build runs the "restore" by default.

Error: Cannot match any routes. URL Segment: - Angular 2

Solved myself. Done some small structural changes also. Route from Component1 to Component2 is done by a single <router-outlet>. Component2 to Comonent3 and Component4 is done by multiple <router-outlet name= "xxxxx"> The resulting contents are :

Component1.html

<nav>
    <a routerLink="/two" class="dash-item">Go to 2</a>
</nav>
    <router-outlet></router-outlet>

Component2.html

 <a [routerLink]="['/two', {outlets: {'nameThree': ['three']}}]">In Two...Go to 3 ...       </a>
 <a [routerLink]="['/two', {outlets: {'nameFour': ['four']}}]">   In Two...Go to 4 ...</a>

 <router-outlet name="nameThree"></router-outlet>
 <router-outlet name="nameFour"></router-outlet>

The '/two' represents the parent component and ['three']and ['four'] represents the link to the respective children of component2 . Component3.html and Component4.html are the same as in the question.

router.module.ts

const routes: Routes = [
{
    path: '',
    redirectTo: 'one',
    pathMatch: 'full'
},
{
    path: 'two',
    component: ClassTwo, children: [

        {
            path: 'three',
            component: ClassThree,
            outlet: 'nameThree'
        },
        {
            path: 'four',
            component: ClassFour,
            outlet: 'nameFour'
        }
    ]
},];

MySQL error code: 1175 during UPDATE in MySQL Workbench

The simplest solution is to define the row limit and execute. This is done for safety purposes.

How to get just the date part of getdate()?

SELECT CAST(FLOOR(CAST(GETDATE() AS float)) as datetime)

or

SELECT CONVERT(datetime,FLOOR(CONVERT(float,GETDATE())))

libc++abi.dylib: terminating with uncaught exception of type NSException (lldb)

In my case if you are using UITableView do not forget to add UITableViewDelegate and UITableViewDataSource next to viewcontroller like this. class MenuController: UIViewController, UITableViewDelegate, UITableViewDataSource

When converting old projects (written in Swift 2.3) to Swift 3 it needs adding these keywords.

Is there a C++ gdb GUI for Linux?

As someone familiar with Visual Studio, I've looked at several open source IDE's to replace it, and KDevelop comes the closest IMO to being something that a Visual C++ person can just sit down and start using. When you run the project in debugging mode, it uses gdb but kdevelop pretty much handles the whole thing so that you don't have to know it's gdb; you're just single stepping or assigning watches to variables.

It still isn't as good as the Visual Studio Debugger, unfortunately.

jQuery get value of selected radio button

To get the value of the selected Radio Button, Use RadioButtonName and the Form Id containing the RadioButton.

$('input[name=radioName]:checked', '#myForm').val()

OR by only

$('form input[type=radio]:checked').val();

Changing plot scale by a factor in matplotlib

As you have noticed, xscale and yscale does not support a simple linear re-scaling (unfortunately). As an alternative to Hooked's answer, instead of messing with the data, you can trick the labels like so:

ticks = ticker.FuncFormatter(lambda x, pos: '{0:g}'.format(x*scale))
ax.xaxis.set_major_formatter(ticks)

A complete example showing both x and y scaling:

import numpy as np
import pylab as plt
import matplotlib.ticker as ticker

# Generate data
x = np.linspace(0, 1e-9)
y = 1e3*np.sin(2*np.pi*x/1e-9) # one period, 1k amplitude

# setup figures
fig = plt.figure()
ax1 = fig.add_subplot(121)
ax2 = fig.add_subplot(122)
# plot two identical plots
ax1.plot(x, y)
ax2.plot(x, y)

# Change only ax2
scale_x = 1e-9
scale_y = 1e3
ticks_x = ticker.FuncFormatter(lambda x, pos: '{0:g}'.format(x/scale_x))
ax2.xaxis.set_major_formatter(ticks_x)

ticks_y = ticker.FuncFormatter(lambda x, pos: '{0:g}'.format(x/scale_y))
ax2.yaxis.set_major_formatter(ticks_y)

ax1.set_xlabel("meters")
ax1.set_ylabel('volt')
ax2.set_xlabel("nanometers")
ax2.set_ylabel('kilovolt')

plt.show() 

And finally I have the credits for a picture:

Left: ax1 no scaling, right: ax2 y axis scaled to kilo and x axis scaled to nano

Note that, if you have text.usetex: true as I have, you may want to enclose the labels in $, like so: '${0:g}$'.

Plotting lines connecting points

I realize this question was asked and answered a long time ago, but the answers don't give what I feel is the simplest solution. It's almost always a good idea to avoid loops whenever possible, and matplotlib's plot is capable of plotting multiple lines with one command. If x and y are arrays, then plot draws one line for every column.

In your case, you can do the following:

x=np.array([-1 ,0.5 ,1,-0.5])
xx = np.vstack([x[[0,2]],x[[1,3]]])
y=np.array([ 0.5,  1, -0.5, -1])
yy = np.vstack([y[[0,2]],y[[1,3]]])
plt.plot(xx,yy, '-o')

Have a long list of x's and y's, and want to connect adjacent pairs?

xx = np.vstack([x[0::2],x[1::2]])
yy = np.vstack([y[0::2],y[1::2]])

Want a specified (different) color for the dots and the lines?

plt.plot(xx,yy, '-ok', mfc='C1', mec='C1')

Plot of two pairs of points, each connected by a separate line

C++11 introduced a standardized memory model. What does it mean? And how is it going to affect C++ programming?

First, you have to learn to think like a Language Lawyer.

The C++ specification does not make reference to any particular compiler, operating system, or CPU. It makes reference to an abstract machine that is a generalization of actual systems. In the Language Lawyer world, the job of the programmer is to write code for the abstract machine; the job of the compiler is to actualize that code on a concrete machine. By coding rigidly to the spec, you can be certain that your code will compile and run without modification on any system with a compliant C++ compiler, whether today or 50 years from now.

The abstract machine in the C++98/C++03 specification is fundamentally single-threaded. So it is not possible to write multi-threaded C++ code that is "fully portable" with respect to the spec. The spec does not even say anything about the atomicity of memory loads and stores or the order in which loads and stores might happen, never mind things like mutexes.

Of course, you can write multi-threaded code in practice for particular concrete systems – like pthreads or Windows. But there is no standard way to write multi-threaded code for C++98/C++03.

The abstract machine in C++11 is multi-threaded by design. It also has a well-defined memory model; that is, it says what the compiler may and may not do when it comes to accessing memory.

Consider the following example, where a pair of global variables are accessed concurrently by two threads:

           Global
           int x, y;

Thread 1            Thread 2
x = 17;             cout << y << " ";
y = 37;             cout << x << endl;

What might Thread 2 output?

Under C++98/C++03, this is not even Undefined Behavior; the question itself is meaningless because the standard does not contemplate anything called a "thread".

Under C++11, the result is Undefined Behavior, because loads and stores need not be atomic in general. Which may not seem like much of an improvement... And by itself, it's not.

But with C++11, you can write this:

           Global
           atomic<int> x, y;

Thread 1                 Thread 2
x.store(17);             cout << y.load() << " ";
y.store(37);             cout << x.load() << endl;

Now things get much more interesting. First of all, the behavior here is defined. Thread 2 could now print 0 0 (if it runs before Thread 1), 37 17 (if it runs after Thread 1), or 0 17 (if it runs after Thread 1 assigns to x but before it assigns to y).

What it cannot print is 37 0, because the default mode for atomic loads/stores in C++11 is to enforce sequential consistency. This just means all loads and stores must be "as if" they happened in the order you wrote them within each thread, while operations among threads can be interleaved however the system likes. So the default behavior of atomics provides both atomicity and ordering for loads and stores.

Now, on a modern CPU, ensuring sequential consistency can be expensive. In particular, the compiler is likely to emit full-blown memory barriers between every access here. But if your algorithm can tolerate out-of-order loads and stores; i.e., if it requires atomicity but not ordering; i.e., if it can tolerate 37 0 as output from this program, then you can write this:

           Global
           atomic<int> x, y;

Thread 1                            Thread 2
x.store(17,memory_order_relaxed);   cout << y.load(memory_order_relaxed) << " ";
y.store(37,memory_order_relaxed);   cout << x.load(memory_order_relaxed) << endl;

The more modern the CPU, the more likely this is to be faster than the previous example.

Finally, if you just need to keep particular loads and stores in order, you can write:

           Global
           atomic<int> x, y;

Thread 1                            Thread 2
x.store(17,memory_order_release);   cout << y.load(memory_order_acquire) << " ";
y.store(37,memory_order_release);   cout << x.load(memory_order_acquire) << endl;

This takes us back to the ordered loads and stores – so 37 0 is no longer a possible output – but it does so with minimal overhead. (In this trivial example, the result is the same as full-blown sequential consistency; in a larger program, it would not be.)

Of course, if the only outputs you want to see are 0 0 or 37 17, you can just wrap a mutex around the original code. But if you have read this far, I bet you already know how that works, and this answer is already longer than I intended :-).

So, bottom line. Mutexes are great, and C++11 standardizes them. But sometimes for performance reasons you want lower-level primitives (e.g., the classic double-checked locking pattern). The new standard provides high-level gadgets like mutexes and condition variables, and it also provides low-level gadgets like atomic types and the various flavors of memory barrier. So now you can write sophisticated, high-performance concurrent routines entirely within the language specified by the standard, and you can be certain your code will compile and run unchanged on both today's systems and tomorrow's.

Although to be frank, unless you are an expert and working on some serious low-level code, you should probably stick to mutexes and condition variables. That's what I intend to do.

For more on this stuff, see this blog post.

How do I use CSS with a ruby on rails application?

With Rails 6.0.0, create your "stylesheet.css" stylesheet at app/assets/stylesheets.

MongoDB vs Firebase

After using Firebase a considerable amount I've come to find something.

If you intend to use it for large, real time apps, it isn't the best choice. It has its own wide array of problems including a bad error handling system and limitations. You will spend significant time trying to understand Firebase and it's kinks. It's also quite easy for a project to become a monolithic thing that goes out of control. MongoDB is a much better choice as far as a backend for a large app goes.

However, if you need to make a small app or quickly prototype something, Firebase is a great choice. It'll be incredibly easy way to hit the ground running.

Remove the complete styling of an HTML button/submit

Your question says "Internet Explorer," but for those interested in other browsers, you can now use all: unset on buttons to unstyle them.

It doesn't work in IE, but it's well-supported everywhere else.

https://caniuse.com/#feat=css-all

Old Safari color warning: Setting the text color of the button after using all: unset can fail in Safari 13.1, due to a bug in WebKit. (The bug is fixed in Safari 14 and up.) "all: unset is setting -webkit-text-fill-color to black, and that overrides color." If you need to set text color after using all: unset, be sure to set both the color and the -webkit-text-fill-color to the same color.

Accessibility warning: For the sake of users who aren't using a mouse pointer, be sure to re-add some :focus styling, e.g. button:focus { outline: orange auto 5px } for keyboard accessibility.

And don't forget cursor: pointer. all: unset removes all styling, including the cursor: pointer, which makes your mouse cursor look like a pointing hand when you hover over the button. You almost certainly want to bring that back.

_x000D_
_x000D_
button {
  all: unset;
  color: blue;
  -webkit-text-fill-color: blue;
  cursor: pointer;
}

button:focus {
  outline: orange 5px auto;
}
_x000D_
<button>check it out</button>
_x000D_
_x000D_
_x000D_

Retrieve specific commit from a remote Git repository

Finally i found a way to clone specific commit using git cherry-pick. Assuming you don't have any repository in local and you are pulling specific commit from remote,

1) create empty repository in local and git init

2) git remote add origin "url-of-repository"

3) git fetch origin [this will not move your files to your local workspace unless you merge]

4) git cherry-pick "Enter-long-commit-hash-that-you-need"

Done.This way, you will only have the files from that specific commit in your local.

Enter-long-commit-hash:

You can get this using -> git log --pretty=oneline

How do I configure modprobe to find my module?

Follow following steps:

  1. Copy hello.ko to /lib/modules/'uname-r'/misc/
  2. Add misc/hello.ko entry in /lib/modules/'uname-r'/modules.dep
  3. sudo depmod
  4. sudo modprobe hello

modprobe will check modules.dep file for any dependency.

How to get a float result by dividing two integer values using T-SQL?

Because SQL Server performs integer division. Try this:

select 1 * 1.0 / 3

This is helpful when you pass integers as params.

select x * 1.0 / y

Shortest distance between a point and a line segment

the accepted answer does not work (e.g. distance between 0,0 and (-10,2,10,2) should be 2).

here's code that works:

   def dist2line2(x,y,line):
     x1,y1,x2,y2=line
     vx = x1 - x
     vy = y1 - y
     ux = x2-x1
     uy = y2-y1
     length = ux * ux + uy * uy
     det = (-vx * ux) + (-vy * uy) #//if this is < 0 or > length then its outside the line segment
     if det < 0:
       return (x1 - x)**2 + (y1 - y)**2
     if det > length:
       return (x2 - x)**2 + (y2 - y)**2
     det = ux * vy - uy * vx
     return det**2 / length
   def dist2line(x,y,line): return math.sqrt(dist2line2(x,y,line))

@Scope("prototype") bean scope not creating new bean

Since Spring 2.5 there's a very easy (and elegant) way to achieve that.

You can just change the params proxyMode and value of the @Scope annotation.

With this trick you can avoid to write extra code or to inject the ApplicationContext every time that you need a prototype inside a singleton bean.

Example:

@Service 
@Scope(value="prototype", proxyMode=ScopedProxyMode.TARGET_CLASS)  
public class LoginAction {}

With the config above LoginAction (inside HomeController) is always a prototype even though the controller is a singleton.

How to find my php-fpm.sock?

I know this is old questions but since I too have the same problem just now and found out the answer, thought I might share it. The problem was due to configuration at pood.d/ directory.

Open

/etc/php5/fpm/pool.d/www.conf

find

listen = 127.0.0.1:9000

change to

listen = /var/run/php5-fpm.sock

Restart both nginx and php5-fpm service afterwards and check if php5-fpm.sock already created.

What is the "hasClass" function with plain JavaScript?

if (document.body.className.split(/\s+/).indexOf("thatClass") !== -1) {
    // has "thatClass"
}

'mat-form-field' is not a known element - Angular 5 & Material2

the problem is in the MatInputModule:

exports: [
    MatInputModule
  ]

PostgreSQL: FOREIGN KEY/ON DELETE CASCADE

In my humble experience with postgres 9.6, cascade delete doesn't work in practice for tables that grow above a trivial size.

  • Even worse, while the delete cascade is going on, the tables involved are locked so those tables (and potentially your whole database) is unusable.
  • Still worse, it's hard to get postgres to tell you what it's doing during the delete cascade. If it's taking a long time, which table or tables is making it slow? Perhaps it's somewhere in the pg_stats information? It's hard to tell.

Search and get a line in Python

If you prefer a one-liner:

matched_lines = [line for line in my_string.split('\n') if "substring" in line]

Delete worksheet in Excel using VBA

Consider:

Sub SheetKiller()
    Dim s As Worksheet, t As String
    Dim i As Long, K As Long
    K = Sheets.Count

    For i = K To 1 Step -1
        t = Sheets(i).Name
        If t = "ID Sheet" Or t = "Summary" Then
            Application.DisplayAlerts = False
                Sheets(i).Delete
            Application.DisplayAlerts = True
        End If
    Next i
End Sub

NOTE:

Because we are deleting, we run the loop backwards.

Basic authentication with fetch?

A solution without dependencies.

Node

headers.set('Authorization', 'Basic ' + Buffer.from(username + ":" + password).toString('base64'));

Browser

headers.set('Authorization', 'Basic ' + btoa(username + ":" + password));

displayname attribute vs display attribute

DisplayName sets the DisplayName in the model metadata. For example:

[DisplayName("foo")]
public string MyProperty { get; set; }

and if you use in your view the following:

@Html.LabelFor(x => x.MyProperty)

it would generate:

<label for="MyProperty">foo</label>

Display does the same, but also allows you to set other metadata properties such as Name, Description, ...

Brad Wilson has a nice blog post covering those attributes.

Pandas groupby month and year

Why not keep it simple?!

GB=DF.groupby([(DF.index.year),(DF.index.month)]).sum()

giving you,

print(GB)
        abc  xyz
2013 6   80  250
     8   40   -5
2014 1   25   15
     2   60   80

and then you can plot like asked using,

GB.plot('abc','xyz',kind='scatter')

PLS-00428: an INTO clause is expected in this SELECT statement

In PLSQL block, columns of select statements must be assigned to variables, which is not the case in SQL statements.

The second BEGIN's SQL statement doesn't have INTO clause and that caused the error.

DECLARE
   PROD_ROW_ID   VARCHAR (10) := NULL;
   VIS_ROW_ID    NUMBER;
   DSC           VARCHAR (512);
BEGIN
   SELECT ROW_ID
     INTO VIS_ROW_ID
     FROM SIEBEL.S_PROD_INT
    WHERE PART_NUM = 'S0146404';

   BEGIN
      SELECT    RTRIM (VIS.SERIAL_NUM)
             || ','
             || RTRIM (PLANID.DESC_TEXT)
             || ','
             || CASE
                   WHEN PLANID.HIGH = 'TEST123'
                   THEN
                      CASE
                         WHEN TO_DATE (PROD.START_DATE) + 30 > SYSDATE
                         THEN
                            'Y'
                         ELSE
                            'N'
                      END
                   ELSE
                      'N'
                END
             || ','
             || 'GB'
             || ','
             || RTRIM (TO_CHAR (PROD.START_DATE, 'YYYY-MM-DD'))
        INTO DSC
        FROM SIEBEL.S_LST_OF_VAL PLANID
             INNER JOIN SIEBEL.S_PROD_INT PROD
                ON PROD.PART_NUM = PLANID.VAL
             INNER JOIN SIEBEL.S_ASSET NETFLIX
                ON PROD.PROD_ID = PROD.ROW_ID
             INNER JOIN SIEBEL.S_ASSET VIS
                ON VIS.PROM_INTEG_ID = PROD.PROM_INTEG_ID
             INNER JOIN SIEBEL.S_PROD_INT VISPROD
                ON VIS.PROD_ID = VISPROD.ROW_ID
       WHERE     PLANID.TYPE = 'Test Plan'
             AND PLANID.ACTIVE_FLG = 'Y'
             AND VISPROD.PART_NUM = VIS_ROW_ID
             AND PROD.STATUS_CD = 'Active'
             AND VIS.SERIAL_NUM IS NOT NULL;
   END;
END;
/

References

http://docs.oracle.com/cd/E11882_01/appdev.112/e25519/static.htm#LNPLS00601 http://docs.oracle.com/cd/B19306_01/appdev.102/b14261/selectinto_statement.htm#CJAJAAIG http://pls-00428.ora-code.com/

jQuery.getJSON - Access-Control-Allow-Origin Issue

It's simple, use $.getJSON() function and in your URL just include

callback=?

as a parameter. That will convert the call to JSONP which is necessary to make cross-domain calls. More info: http://api.jquery.com/jQuery.getJSON/

why does DateTime.ToString("dd/MM/yyyy") give me dd-MM-yyyy?

Pass CultureInfo.InvariantCulture as the second parameter of DateTime, it will return the string as what you want, even a very special format:

DateTime.Now.ToString("dd|MM|yyyy", CultureInfo.InvariantCulture)

will return: 28|02|2014

Proxy Basic Authentication in C#: HTTP 407 error

here is the correct way of using proxy along with creds..

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);

IWebProxy proxy = request.Proxy;                    
if (proxy != null)
{
    Console.WriteLine("Proxy: {0}", proxy.GetProxy(request.RequestUri));
}
else
{
    Console.WriteLine("Proxy is null; no proxy will be used");
}

WebProxy myProxy = new WebProxy();
Uri newUri = new Uri("http://20.154.23.100:8888");
// Associate the newUri object to 'myProxy' object so that new myProxy settings can be set.
myProxy.Address = newUri;
// Create a NetworkCredential object and associate it with the 
// Proxy property of request object.
myProxy.Credentials = new NetworkCredential("userName", "password");
request.Proxy = myProxy;

Thanks everyone for help... :)

Java IOException "Too many open files"

You're obviously not closing your file descriptors before opening new ones. Are you on windows or linux?

Date query with ISODate in mongodb doesn't seem to work

Although $date is a part of MongoDB Extended JSON and that's what you get as default with mongoexport I don't think you can really use it as a part of the query.

If try exact search with $date like below:

db.foo.find({dt: {"$date": "2012-01-01T15:00:00.000Z"}})

you'll get error:

error: { "$err" : "invalid operator: $date", "code" : 10068 }

Try this:

db.mycollection.find({
    "dt" : {"$gte": new Date("2013-10-01T00:00:00.000Z")}
})

or (following comments by @user3805045):

db.mycollection.find({
    "dt" : {"$gte": ISODate("2013-10-01T00:00:00.000Z")}
})

ISODate may be also required to compare dates without time (noted by @MattMolnar).

According to Data Types in the mongo Shell both should be equivalent:

The mongo shell provides various methods to return the date, either as a string or as a Date object:

  • Date() method which returns the current date as a string.
  • new Date() constructor which returns a Date object using the ISODate() wrapper.
  • ISODate() constructor which returns a Date object using the ISODate() wrapper.

and using ISODate should still return a Date object.

{"$date": "ISO-8601 string"} can be used when strict JSON representation is required. One possible example is Hadoop connector.

Disable a link in Bootstrap

I just removed 'href' attribute from that anchor tag which I want to disable

$('#idOfAnchorTag').removeAttr('href');

$('#idOfAnchorTag').attr('class', $('#idOfAnchorTag').attr('class')+ ' disabled');

How to check for a Null value in VB.NET

If Not editTransactionRow.pay_id AndAlso String.IsNullOrEmpty(editTransactionRow.pay_id.ToString()) = False Then
    stTransactionPaymentID = editTransactionRow.pay_id 'Check for null value
End If

jQuery event to trigger action when a div is made visible

The problem is being addressed by DOM mutation observers. They allow you to bind an observer (a function) to events of changing content, text or attributes of dom elements.

With the release of IE11, all major browsers support this feature, check http://caniuse.com/mutationobserver

The example code is a follows:

_x000D_
_x000D_
$(function() {
  $('#show').click(function() {
    $('#testdiv').show();
  });

  var observer = new MutationObserver(function(mutations) {
    alert('Attributes changed!');
  });
  var target = document.querySelector('#testdiv');
  observer.observe(target, {
    attributes: true
  });

});
_x000D_
<div id="testdiv" style="display:none;">hidden</div>
<button id="show">Show hidden div</button>

<script type="text/javascript" src="https://code.jquery.com/jquery-1.9.1.min.js"></script>
_x000D_
_x000D_
_x000D_

How do I rotate the Android emulator display?

Press Ctrl + F10 to rotate the emulator screen.

How do you post data with a link

I assume that each house is stored in its own table and has an 'id' field, e.g house id. So when you loop through the houses and display them, you could do something like this:

<a href="house.php?id=<?php echo $house_id;?>">
  <?php echo $house_name;?>
</a>

Then in house.php, you would get the house id using $_GET['id'], validate it using is_numeric() and then display its info.

How to grep for contents after pattern?

grep -Po 'potato:\s\K.*' file

-P to use Perl regular expression

-o to output only the match

\s to match the space after potato:

\K to omit the match

.* to match rest of the string(s)

How to set environment via `ng serve` in Angular 6

You need to use the new configuration option (this works for ng build and ng serve as well)

ng serve --configuration=local

or

ng serve -c local

If you look at your angular.json file, you'll see that you have finer control over settings for each configuration (aot, optimizer, environment files,...)

"configurations": {
  "production": {
    "optimization": true,
    "outputHashing": "all",
    "sourceMap": false,
    "extractCss": true,
    "namedChunks": false,
    "aot": true,
    "extractLicenses": true,
    "vendorChunk": false,
    "buildOptimizer": true,
    "fileReplacements": [
      {
        "replace": "src/environments/environment.ts",
        "with": "src/environments/environment.prod.ts"
      }
    ]
  }
}

You can get more info here for managing environment specific configurations.

As pointed in the other response below, if you need to add a new 'environment', you need to add a new configuration to the build task and, depending on your needs, to the serve and test tasks as well.

Adding a new environment

Edit: To make it clear, file replacements must be specified in the build section. So if you want to use ng serve with a specific environment file (say dev2), you first need to modify the build section to add a new dev2 configuration

"build": {
   "configurations": {
        "dev2": {

          "fileReplacements": [
            {
              "replace": "src/environments/environment.ts",
              "with": "src/environments/environment.dev2.ts"
            }
            /* You can add all other options here, such as aot, optimization, ... */
          ],
          "serviceWorker": true
        },

Then modify your serve section to add a new configuration as well, pointing to the dev2 build configuration you just declared

"serve":
      "configurations": {
        "dev2": {
          "browserTarget": "projectName:build:dev2"
        }

Then you can use ng serve -c dev2, which will use the dev2 config file

Which Ruby version am I really running?

If you have access to a console in the context you are investigating, you can determine which version you are running by printing the value of the global constant RUBY_VERSION.

Passing a URL with brackets to curl

I was getting this error though there were no (obvious) brackets in my URL, and in my situation the --globoff command will not solve the issue.

For example (doing this on on mac in iTerm2):

for endpoint in $(grep some_string output.txt); do curl "http://1.2.3.4/api/v1/${endpoint}" ; done

I have grep aliased to "grep --color=always". As a result, the above command will result in this error, with some_string highlighted in whatever colour you have grep set to:

curl: (3) bad range in URL position 31:
http://1.2.3.4/api/v1/lalalasome_stringlalala

The terminal was transparently translating the [colour\codes]some_string[colour\codes] into the expected no-special-characters URL when viewed in terminal, but behind the scenes the colour codes were being sent in the URL passed to curl, resulting in brackets in your URL.

Solution is to not use match highlighting.

fatal: does not appear to be a git repository

my local and remote machines are both OS X. I was having trouble until I checked the file structure of the git repo that xCode Server provides me. Essentially everything is chmod 777 * in that repo so to setup a separate non xCode repo on the same machine in my remote account there I did this:

REMOTE MACHINE

  1. Login to your account
  2. Create a master dir for all projects 'mkdir git'
  3. chmod 775 git then cd into it
  4. make a project folder 'mkdir project1'
  5. chmod 777 project1 then cd into it
  6. run command 'git init' to make the repo
  7. this creates a .git dir. do command 'chmod 777 .git' then cd into it
  8. run command 'chmod 777 *' to make all files in .git 777 mod
  9. cd back out to myproject1 (cd ..)
  10. setup a test file in the new repo w/command 'touch test.php'
  11. add it to the repo staging area with command 'git add test.php'
  12. run command "git commit -m 'new file'" to add file to repo
  13. run command 'git status' and you should get "working dir clean" msg
  14. cd back to master dir with 'cd ..'
  15. in the master dir make a symlink 'ln -s project1 project1.git'
  16. run command 'pwd' to get full path
  17. in my case the full path was "/Users/myname/git/project1.git'
  18. write down the full path for later use in URL
  19. exit from the REMOTE MACHINE

LOCAL MACHINE

  1. create a project folder somewhere 'newproj1' with 'mkdir newproj1'
  2. cd into it
  3. run command 'git init'
  4. make an alias to the REMOTE MACHINE
  5. the alias command format is 'git remote add your_alias_here URL'
  6. make sure your URL is correct. This caused me headaches initially
  7. URL = 'ssh://[email protected]/Users/myname/git/project1.git'
  8. after you do 'git remote add alias URL' do 'git remote -v'
  9. the command should respond with a fetch and push line
  10. run cmd 'git pull your_alias master' to get test.php from REMOTE repo
  11. after the command in #10 you should see a nice message.
  12. run command 'git push --set-upstream your_alias master'
  13. after command in 12 you should see nice message
  14. command in #12 sets up REMOTE as the project master (root)

For me, i learned getting a clean start with a git repo on a LOCAL and REMOTE requires all initial work in a shell first. Then, after the above i was able to easily setup the LOCAL and REMOTE git repos in my IDE and do all the basic git commands using the GUI of the IDE.

I had difficulty until I started at the remote first, then did the local, and until i opened up all the permissions on remote. In addition, having the exact full path in the URL to the symlink was critical to succeed.

Again, this all worked on OS X, local and remote machines.

Find a file with a certain extension in folder

You could use the Directory class

 Directory.GetFiles(path, "*.txt", SearchOption.AllDirectories)

Turning off hibernate logging console output

You can disabled the many of the outputs of hibernate setting this props of hibernate (hb configuration) a false:

hibernate.show_sql
hibernate.generate_statistics
hibernate.use_sql_comments

But if you want to disable all console info you must to set the logger level a NONE of FATAL of class org.hibernate like Juha say.

How can I install Python's pip3 on my Mac?

After upgrading to macOS v10.15 (Catalina), and upgrading all my vEnv modules, pip3 stopped working (gave error: "TypeError: 'module' object is not callable").

I found question 58386953 which led to here and solution.

  1. Exit from the vEnv (I started a fresh shell)
  2. sudo python3 -m pip uninstall pip (this is necessary, but it did not fix problem, because it removed the base Python pip, but it didn't touch my vEnv pip)
  3. sudo easy_install pip (reinstalling pip in base Python, not in vEnv)
  4. cd to your vEnv/bin and type "source activate" to get into vEnv
  5. rm pip pip3 pip3.6 (it seems to be the only way to get rid of the bogus pip's in vEnv)
  6. Now pip is gone from vEnv, and we can use the one in the base Python (I wasn't able to successfully install pip into vEnv after deleting)

Angular 2 change event on every keypress

<input type="text" [ngModel]="mymodel" (keypress)="mymodel=$event.target.value"/>
{{mymodel}}

The name 'InitializeComponent' does not exist in the current context

I had this error messages too after I added a new platform 'x86' to the Solution Configuration Manager. Before it had only 'Any CPU'. The solution was still running but showed multiple of these error messages in the error window.

I found the problem was that in the project properties the 'Output Path' was now pointing to "bin\x86\Debug". This was put in by Configuration Manager at the add operation. The output path of the 'Any CPU' platform was always just "bin" (because this test project was never built in release mode), so the Configuration Manager figured it should add the "\x86\Debug" by itself. There was no indication whatsoever from the error messages that the build output could be the cause and I still don't understand how the project could even run like this. After setting it to "bin" for all projects in the new 'x86' configuration all of the errors vanished.

How can I count the rows with data in an Excel sheet?

This is what I finally came up with, which works great!

{=SUM(IF((ISTEXT('Worksheet Name!A:A))+(ISTEXT('CCSA Associates'!E:E)),1,0))-1}

Don't forget since it is an array to type the formula above without the "{}", and to CTRL + SHIFT + ENTER instead of just ENTER for the "{}" to appear and for it to be entered properly.

How to restore a SQL Server 2012 database to SQL Server 2008 R2?

Here is another option which did the trick for me: https://dba.stackexchange.com/a/44340

There I used Option B. This is not my idea so all credit goes to the original author. I am just putting it in here also as I know that sometimes links don't function and it is recommended to have the full story handy.

Just one tip from me: First resolve the schema incompatibilities if any. Then pouring in the data should be a breeze.


Option A: Script out database in compatibility mode using Generate script option:

Note: If you script out database with schema and data, depending on your data size, the script will be massive and wont be handled by SSMS, sqlcmd or osql (might be in GB as well).

enter image description here

Option B:

First script out tables first with all Indexes, FK's, etc and create blank tables in the destination database - option with SCHEMA ONLY (No data).

Use BCP to insert data

I. BCP out the data using below script. Set SSMS in Text Mode and copy the output generated by below script in a bat file.

-- save below output in a bat file by executing below in SSMS in TEXT mode

-- clean up: create a bat file with this command --> del D:\BCP\*.dat 

select '"C:\Program Files\Microsoft SQL Server\100\Tools\Binn\bcp.exe" ' /* path to BCP.exe */
    +  QUOTENAME(DB_NAME())+ '.' /* Current Database */
    +  QUOTENAME(SCHEMA_NAME(SCHEMA_ID))+'.'            
    +  QUOTENAME(name)  
    +  ' out D:\BCP\'  /* Path where BCP out files will be stored */
    +  REPLACE(SCHEMA_NAME(schema_id),' ','') + '_' 
    +  REPLACE(name,' ','') 
    + '.dat -T -E -SServerName\Instance -n' /* ServerName, -E will take care of Identity, -n is for Native Format */
from sys.tables
where is_ms_shipped = 0 and name <> 'sysdiagrams'                       /* sysdiagrams is classified my MS as UserTable and we dont want it */
/*and schema_name(schema_id) <> 'unwantedschema'    */                             /* Optional to exclude any schema  */
order by schema_name(schema_id)

II. Run the bat file that will generate the .dat files in the folder that you have specified.

III. Run below script on the destination server with SSMS in text mode again.

--- Execute this on the destination server.database from SSMS.

--- Make sure the change the @Destdbname and the bcp out path as per your environment.

declare @Destdbname sysname
set @Destdbname = 'destinationDB' /* Destination Database Name where you want to Bulk Insert in */
select 'BULK INSERT '
/*Remember Tables must be present on destination database */ 
+ QUOTENAME(@Destdbname) + '.' 
+ QUOTENAME(SCHEMA_NAME(SCHEMA_ID)) 
+ '.' + QUOTENAME(name) 
+ ' from ''D:\BCP\' /* Change here for bcp out path */ 
+ REPLACE(SCHEMA_NAME(schema_id), ' ', '') + '_' + REPLACE(name, ' ', '') 
+ '.dat'' with ( KEEPIDENTITY, DATAFILETYPE = ''native'', TABLOCK )' 
+ char(10) 
+ 'print ''Bulk insert for ' + REPLACE(SCHEMA_NAME(schema_id), ' ', '') + '_' + REPLACE(name, ' ', '') + ' is done... ''' 
+ char(10) + 'go'
from sys.tables
where is_ms_shipped = 0
and name <> 'sysdiagrams' /* sysdiagrams is classified my MS as UserTable and we dont want it */
--and schema_name(schema_id) <> 'unwantedschema' /* Optional to exclude any schema */
    order by schema_name(schema_id)

IV. Run the output using SSMS to insert data back in the tables.

This is very fast BCP method as it uses Native mode.

Java SSL: how to disable hostname verification

It should be possible to create custom java agent that overrides default HostnameVerifier:

import javax.net.ssl.*;
import java.lang.instrument.Instrumentation;

public class LenientHostnameVerifierAgent {
    public static void premain(String args, Instrumentation inst) {
        HttpsURLConnection.setDefaultHostnameVerifier(new HostnameVerifier() {
            public boolean verify(String s, SSLSession sslSession) {
                return true;
            }
        });
    }
}

Then just add -javaagent:LenientHostnameVerifierAgent.jar to program's java startup arguments.

Is there a better way to do optional function parameters in JavaScript?

Those ones are shorter than the typeof operator version.

function foo(a, b) {
    a !== undefined || (a = 'defaultA');
    if(b === undefined) b = 'defaultB';
    ...
}

.attr("disabled", "disabled") issue

To add disabled attribute

$('#id').attr("disabled", "true");

To remove Disabled Attribute

$('#id').removeAttr('disabled');

Copy Paste in Bash on Ubuntu on Windows

As others have said, there is now an option for Ctrl+Shf+Vfor paste in Windows 10 Insider build #17643.

Unfortunately this isn't in my muscle memory and as a user of TTY terminals I'd like to use Shf+Ins as I do on all the Linux boxes I connect to.

This is possible on Windows 10 if you install ConEmu which wraps the terminal in a new GUI and allows Shf+Ins for paste. It also allows you to tweak the behaviour in the Properties.

The Console looks like this:ConEmu Console

Copy options:ConEmu Copy properties

Paste options:ConEmu Paste properties

Shf+Ins works out of the box. I can't remember if you need to configure bash as one of the shells it uses but if you do, here is the task properties to add it:ConEmu Bash Task Properties

Also allows tabbed Consoles (including different types, cmd.exe, powershell etc). I've been using this since early Windows 7 and in those days it made the command line on Windows usable!

How to view Plugin Manager in Notepad++

I changed the plugin folder name. Restart Notepad ++ It works now, a

Making a <button> that's a link in HTML

Use javascript:

<button onclick="window.location.href='/css_page.html'">CSS page</button>

You can always style the button in css anyaways. Hope it helped!

Good luck!

MySQL Join Where Not Exists

I'd probably use a LEFT JOIN, which will return rows even if there's no match, and then you can select only the rows with no match by checking for NULLs.

So, something like:

SELECT V.*
FROM voter V LEFT JOIN elimination E ON V.id = E.voter_id
WHERE E.voter_id IS NULL

Whether that's more or less efficient than using a subquery depends on optimization, indexes, whether its possible to have more than one elimination per voter, etc.

Calculate the mean by group

Adding alternative base R approach, which remains fast under various cases.

rowsummean <- function(df) {
  rowsum(df$speed, df$dive) / tabulate(df$dive)
}

Borrowing the benchmarks from @Ari:

10 rows, 2 groups

res1

10 million rows, 10 groups

res2

10 million rows, 1000 groups

res3

How do I enable/disable log levels in Android?

Stripping out the logging with proguard (see answer from @Christopher ) was easy and fast, but it caused stack traces from production to mismatch the source if there was any debug logging in the file.

Instead, here's a technique that uses different logging levels in development vs. production, assuming that proguard is used only in production. It recognizes production by seeing if proguard has renamed a given class name (in the example, I use "com.foo.Bar"--you would replace this with a fully-qualified class name that you know will be renamed by proguard).

This technique makes use of commons logging.

private void initLogging() {
    Level level = Level.WARNING;
    try {
        // in production, the shrinker/obfuscator proguard will change the
        // name of this class (and many others) so in development, this
        // class WILL exist as named, and we will have debug level
        Class.forName("com.foo.Bar");
        level = Level.FINE;
    } catch (Throwable t) {
        // no problem, we are in production mode
    }
    Handler[] handlers = Logger.getLogger("").getHandlers();
    for (Handler handler : handlers) {
        Log.d("log init", "handler: " + handler.getClass().getName());
        handler.setLevel(level);
    }
}

What is the difference between % and %% in a cmd file?

(Explanation in more details can be found in an archived Microsoft KB article.)

Three things to know:

  1. The percent sign is used in batch files to represent command line parameters: %1, %2, ...
  2. Two percent signs with any characters in between them are interpreted as a variable:

    echo %myvar%

  3. Two percent signs without anything in between (in a batch file) are treated like a single percent sign in a command (not a batch file): %%f

Why's that?

For example, if we execute your (simplified) command line

FOR /f %f in ('dir /b .') DO somecommand %f

in a batch file, rule 2 would try to interpret

%f in ('dir /b .') DO somecommand %

as a variable. In order to prevent that, you have to apply rule 3 and escape the % with an second %:

FOR /f %%f in ('dir /b .') DO somecommand %%f

How to change package name of an Android Application

  1. Fist change the package name in the manifest file
  2. Re-factor > Rename the name of the package in src folder and put a tick for rename subpackages
  3. That is all you are done.

How to POST request using RestSharp

My RestSharp POST method:

var client = new RestClient(ServiceUrl);

var request = new RestRequest("/resource/", Method.POST);

// Json to post.
string jsonToSend = JsonHelper.ToJson(json);

request.AddParameter("application/json; charset=utf-8", jsonToSend, ParameterType.RequestBody);
request.RequestFormat = DataFormat.Json;

try
{
    client.ExecuteAsync(request, response =>
    {
        if (response.StatusCode == HttpStatusCode.OK)
        {
            // OK
        }
        else
        {
            // NOK
        }
    });
}
catch (Exception error)
{
    // Log
}

How do I iterate through children elements of a div using jQuery?

It can be done this way as well:

$('input', '#div').each(function () {
    console.log($(this)); //log every element found to console output
});

How to skip a iteration/loop in while-loop

You don't need to skip the iteration, since the rest of it is in the else statement, it will only be executed if the condition is not true.

But if you really need to skip it, you can use the continue; statement.

What are the obj and bin folders (created by Visual Studio) used for?

The obj directory is for intermediate object files and other transient data files that are generated by the compiler or build system during a build. The bin directory is the directory that final output binaries (and any dependencies or other deployable files) will be written to.

You can change the actual directories used for both purposes within the project settings, if you like.

Decimal or numeric values in regular expression validation

/([0-9]+[.,]*)+/ matches any number with or without coma or dots

it can match

         122
         122,354
         122.88
         112,262,123.7678

bug: it also matches 262.4377,3883 ( but it doesn't matter parctically)

tar: add all files and directories in current directory INCLUDING .svn and so on

The problem with the most solutions provided here is that tar contains ./ at the begging of every entry. So this results in having . directory when opening it through GUI compressor. So what I ended up doing is:

ls -1A | xargs -d "\n" tar cfz my.tar.gz

If you already have my.tar.gz in current directory you may want to grep this out:

ls -1A | grep -v my.tar.gz | xargs -d "\n" tar cfz my.tar.gz

Be aware of that xargs has certain limit (see xargs --show-limits). So this solution would not work if you are trying to create a package which has lots of entries (directories and files) on a directory which you are trying to tar.

Convert month name to month number in SQL Server

I recently had a similar experience (sql server 2012). I did not have the luxury of controlling the input, I just had a requirement to report on it. Luckily the dates were entered with leading 3 character alpha month abbreviations, so this made it simple & quick:

TRY_CONVERT(DATETIME,REPLACE(obs.DateValueText,SUBSTRING(obs.DateValueText,1,3),CHARINDEX(SUBSTRING(obs.DateValueText,1,3),'...JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC')/4)) 

It worked for 12 hour:
Feb-14-2015 5:00:00 PM 2015-02-14 17:00:00.000
and 24 hour times:
Sep-27-2013 22:45 2013-09-27 22:45:00.000

(thanks ryanyuyu)

How do I add a library path in cmake?

The simplest way of doing this would be to add

include_directories(${CMAKE_SOURCE_DIR}/inc)
link_directories(${CMAKE_SOURCE_DIR}/lib)

add_executable(foo ${FOO_SRCS})
target_link_libraries(foo bar) # libbar.so is found in ${CMAKE_SOURCE_DIR}/lib

The modern CMake version that doesn't add the -I and -L flags to every compiler invocation would be to use imported libraries:

add_library(bar SHARED IMPORTED) # or STATIC instead of SHARED
set_target_properties(bar PROPERTIES
  IMPORTED_LOCATION "${CMAKE_SOURCE_DIR}/lib/libbar.so"
  INTERFACE_INCLUDE_DIRECTORIES "${CMAKE_SOURCE_DIR}/include/libbar"
)

set(FOO_SRCS "foo.cpp")
add_executable(foo ${FOO_SRCS})
target_link_libraries(foo bar) # also adds the required include path

If setting the INTERFACE_INCLUDE_DIRECTORIES doesn't add the path, older versions of CMake also allow you to use target_include_directories(bar PUBLIC /path/to/include). However, this no longer works with CMake 3.6 or newer.

String replace a Backslash

sSource = sSource.replace("\\/", "/");
  • String is immutable - each method you invoke on it does not change its state. It returns a new instance holding the new state instead. So you have to assign the new value to a variable (it can be the same variable)
  • replaceAll(..) uses regex. You don't need that.

What is the use of "assert"?

if the statement after assert is true then the program continues , but if the statement after assert is false then the program gives an error. Simple as that.

e.g.:

assert 1>0   #normal execution
assert 0>1   #Traceback (most recent call last):
             #File "<pyshell#11>", line 1, in <module>
             #assert 0>1
             #AssertionError

Jetty: HTTP ERROR: 503/ Service Unavailable

2012-04-20 11:14:32.617:WARN:oejx.XmlParser:FATAL@file:/C:/Users/***/workspace/Test/WEB-INF/web.xml line:1 col:7 : org.xml.sax.SAXParseException: The processing instruction target matching "[xX][mM][lL]" is not allowed.

You Log says, that you web.xml is malformed. Line 1, colum 7. It may be a UTF-8 Byte-Order-Marker

Try to verify, that your xml is wellformed and does not have a BOM. Java doesn't use BOMs.

How can I remove an element from a list, with lodash?

In Addition to @thefourtheye answer, using predicate instead of traditional anonymous functions:

  _.remove(obj.subTopics, (currentObject) => {
        return currentObject.subTopicId === stToDelete;
    });

OR

obj.subTopics = _.filter(obj.subTopics, (currentObject) => {
    return currentObject.subTopicId !== stToDelete;
});

take(1) vs first()

Operators first() and take(1) aren't the same.

The first() operator takes an optional predicate function and emits an error notification when no value matched when the source completed.

For example this will emit an error:

import { EMPTY, range } from 'rxjs';
import { first, take } from 'rxjs/operators';

EMPTY.pipe(
  first(),
).subscribe(console.log, err => console.log('Error', err));

... as well as this:

range(1, 5).pipe(
  first(val => val > 6),
).subscribe(console.log, err => console.log('Error', err));

While this will match the first value emitted:

range(1, 5).pipe(
  first(),
).subscribe(console.log, err => console.log('Error', err));

On the other hand take(1) just takes the first value and completes. No further logic is involved.

range(1, 5).pipe(
  take(1),
).subscribe(console.log, err => console.log('Error', err));

Then with empty source Observable it won't emit any error:

EMPTY.pipe(
  take(1),
).subscribe(console.log, err => console.log('Error', err));

Jan 2019: Updated for RxJS 6

URL encoding the space character: + or %20?

I would recommend %20.

Are you hard-coding them?

This is not very consistent across languages, though. If I'm not mistaken, in PHP urlencode() treats spaces as + whereas Python's urlencode() treats them as %20.

EDIT:

It seems I'm mistaken. Python's urlencode() (at least in 2.7.2) uses quote_plus() instead of quote() and thus encodes spaces as "+". It seems also that the W3C recommendation is the "+" as per here: http://www.w3.org/TR/html4/interact/forms.html#h-17.13.4.1

And in fact, you can follow this interesting debate on Python's own issue tracker about what to use to encode spaces: http://bugs.python.org/issue13866.

EDIT #2:

I understand that the most common way of encoding " " is as "+", but just a note, it may be just me, but I find this a bit confusing:

import urllib
print(urllib.urlencode({' ' : '+ '})

>>> '+=%2B+'

Generic deep diff between two objects

I modified @sbgoran's answer so that the resulting diff object includes only the changed values, and omits values that were the same. In addition, it shows both the original value and the updated value.

var deepDiffMapper = function () {
    return {
        VALUE_CREATED: 'created',
        VALUE_UPDATED: 'updated',
        VALUE_DELETED: 'deleted',
        VALUE_UNCHANGED: '---',
        map: function (obj1, obj2) {
            if (this.isFunction(obj1) || this.isFunction(obj2)) {
                throw 'Invalid argument. Function given, object expected.';
            }
            if (this.isValue(obj1) || this.isValue(obj2)) {
                let returnObj = {
                    type: this.compareValues(obj1, obj2),
                    original: obj1,
                    updated: obj2,
                };
                if (returnObj.type != this.VALUE_UNCHANGED) {
                    return returnObj;
                }
                return undefined;
            }

            var diff = {};
            let foundKeys = {};
            for (var key in obj1) {
                if (this.isFunction(obj1[key])) {
                    continue;
                }

                var value2 = undefined;
                if (obj2[key] !== undefined) {
                    value2 = obj2[key];
                }

                let mapValue = this.map(obj1[key], value2);
                foundKeys[key] = true;
                if (mapValue) {
                    diff[key] = mapValue;
                }
            }
            for (var key in obj2) {
                if (this.isFunction(obj2[key]) || foundKeys[key] !== undefined) {
                    continue;
                }

                let mapValue = this.map(undefined, obj2[key]);
                if (mapValue) {
                    diff[key] = mapValue;
                }
            }

            //2020-06-13: object length code copied from https://stackoverflow.com/a/13190981/2336212
            if (Object.keys(diff).length > 0) {
                return diff;
            }
            return undefined;
        },
        compareValues: function (value1, value2) {
            if (value1 === value2) {
                return this.VALUE_UNCHANGED;
            }
            if (this.isDate(value1) && this.isDate(value2) && value1.getTime() === value2.getTime()) {
                return this.VALUE_UNCHANGED;
            }
            if (value1 === undefined) {
                return this.VALUE_CREATED;
            }
            if (value2 === undefined) {
                return this.VALUE_DELETED;
            }
            return this.VALUE_UPDATED;
        },
        isFunction: function (x) {
            return Object.prototype.toString.call(x) === '[object Function]';
        },
        isArray: function (x) {
            return Object.prototype.toString.call(x) === '[object Array]';
        },
        isDate: function (x) {
            return Object.prototype.toString.call(x) === '[object Date]';
        },
        isObject: function (x) {
            return Object.prototype.toString.call(x) === '[object Object]';
        },
        isValue: function (x) {
            return !this.isObject(x) && !this.isArray(x);
        }
    }
}();

Open-Source Examples of well-designed Android Applications?

All of the applications delivered with Android (Calendar, Contacts, Email, etc) are all open-source, but not part of the SDK. The source for those projects is here: https://android.googlesource.com/ (look at /platform/packages/apps). I've referred to those sources several times when I've used an application on my phone and wanted to see how a particular feature was implemented.

What is 'Context' on Android?

Definition of Context

  • Context represents environment data
  • It provides access to things such as databases

Simpler terms (example 1)

  • Consider Person-X is the CEO of a start-up software company.

  • There is a lead architect present in the company, this lead architect does all the work in the company which involves such as database, UI etc.

  • Now the CEO Hires a new Developer.

  • It is the Architect who tells the responsibility of the newly hired person based on the skills of the new person that whether he will work on Database or UI etc.

Simpler terms (example 2)

  • It's like access to android activity to the app's resource.

  • It's similar to when you visit a hotel, you want breakfast, lunch & dinner in the suitable timings, right?

  • There are many other things you like during the time of stay. How do you get these things?

  • You ask the room-service person to bring these things for you.

  • Here the room-service person is the context considering you are the single activity and the hotel to be your app, finally the breakfast, lunch & dinner has to be the resources.


Things that involve context are:

  1. Loading a resource.
  2. Launching a new activity.
  3. Creating views.
  4. obtaining system service.

Context is the base class for Activity, Service, Application, etc

Another way to describe this: Consider context as remote of a TV & channel's in the television are resources, services, using intents, etc - - - Here remote acts as an access to get access to all the different resources into the foreground.

  • So, Remote has access to channels such as resources, services, using intents, etc ....

  • Likewise ... Whoever has access to remote naturally has access to all the things such as resources, services, using intents, etc


Different methods by which you can get context

  • getApplicationContext()
  • getContext()
  • getBaseContext()
  • or this (when in the activity class)

Example:

TextView tv = new TextView(this);

The keyword this refers to the context of the current activity.

How to run a Command Prompt command with Visual Basic code?

Or, you could do it the really simple way.

Dim OpenCMD 
OpenCMD = CreateObject("wscript.shell")
OpenCMD.run("Command Goes Here")

Adding a collaborator to my free GitHub account?

Go to Manage Access page under settings (https://github.com/user/repo/settings/access) and add the collaborators as needed.

Screenshot:

enter image description here

how to overwrite css style

You can add your styles in the required page after the external style sheet so they'll cascade and overwrite the first set of rules.

<link rel="stylesheet" href="allpages.css">
<style>
.flex-control-thumbs li {
  width: auto;
  float: none;
}
</style>

Install-Module : The term 'Install-Module' is not recognized as the name of a cmdlet

I think the above answer posted by Jeremy Thompson is the correct one, but I don't have enough street cred to comment. Once I updated nuget and powershellget, Install-Module was available for me.

Install-PackageProvider -Name NuGet -MinimumVersion 2.8.5.201 -Force 
Install-PackageProvider -Name Powershellget -Force

What is interesting is that the version numbers returned by get-packageprovider didn't change after the update.

What is the boundary in multipart/form-data?

Is the ??? free to be defined by the user?

Yes.

or is it supplied by the HTML?

No. HTML has nothing to do with that. Read below.

Is it possible for me to define the ??? as abcdefg?

Yes.

If you want to send the following data to the web server:

name = John
age = 12

using application/x-www-form-urlencoded would be like this:

name=John&age=12

As you can see, the server knows that parameters are separated by an ampersand &. If & is required for a parameter value then it must be encoded.

So how does the server know where a parameter value starts and ends when it receives an HTTP request using multipart/form-data?

Using the boundary, similar to &.

For example:

--XXX
Content-Disposition: form-data; name="name"

John
--XXX
Content-Disposition: form-data; name="age"

12
--XXX--

In that case, the boundary value is XXX. You specify it in the Content-Type header so that the server knows how to split the data it receives.

So you need to:

  • Use a value that won't appear in the HTTP data sent to the server.

  • Be consistent and use the same value everywhere in the request message.

How do I find out which process is locking a file using .NET?

One of the good things about handle.exe is that you can run it as a subprocess and parse the output.

We do this in our deployment script - works like a charm.

C++ performance vs. Java/C#

You might get short bursts when Java or CLR is faster than C++, but overall the performance is worse for the life of the application: see www.codeproject.com/KB/dotnet/RuntimePerformance.aspx for some results for that.

Has been blocked by CORS policy: Response to preflight request doesn’t pass access control check

The provided solution here is correct. However, the same error can also occur from a user error, where your endpoint request method is NOT matching the method your using when making the request.

For example, the server endpoint is defined with "RequestMethod.PUT" while you are requesting the method as POST.

How can I make Jenkins CI with Git trigger on pushes to master?

My solution for a local git server: go to your local git server hook directory, ignore the existing update.sample and create a new file literally named as "update", such as:

gituser@me:~/project.git/hooks$ pwd
/home/gituser/project.git/hooks
gituser@me:~/project.git/hooks$ cat update
#!/bin/sh
echo "XXX from  update file"
curl -u admin:11f778f9f2c4d1e237d60f479974e3dae9 -X POST http://localhost:8080/job/job4_pullsrc_buildcontainer/build?token=11f778f9f2c4d1e237d60f479974e3dae9

exit 0
gituser@me:~/project.git/hooks$ 

The echo statement will be displayed under your git push result, token can be taken from your jenkins job configuration, browse to find it. If the file "update" is not called, try some other files with the same name without extension "sample".

That's all you need

Angular CLI SASS options

Tell angular-cli to always use scss by default

To avoid passing --style scss each time you generate a project, you might want to adjust your default configuration of angular-cli globally, with the following command:

ng set --global defaults.styleExt scss


Please note that some versions of angular-cli contain a bug with reading the above global flag (see link). If your version contains this bug, generate your project with:

ng new some_project_name --style=scss

Splitting a Java String by the pipe symbol using split("|")

test.split("\\|",999);

Specifing a limit or max will be accurate for examples like: "boo|||a" or "||boo|" or " |||"

But test.split("\\|"); will return different length strings arrays for the same examples.

use reference: link

Copy files from one directory into an existing directory

Depending on some details you might need to do something like this:

r=$(pwd)
case "$TARG" in
    /*) p=$r;;
    *) p="";;
    esac
cd "$SRC" && cp -r . "$p/$TARG"
cd "$r"

... this basically changes to the SRC directory and copies it to the target, then returns back to whence ever you started.

The extra fussing is to handle relative or absolute targets.

(This doesn't rely on subtle semantics of the cp command itself ... about how it handles source specifications with or without a trailing / ... since I'm not sure those are stable, portable, and reliable beyond just GNU cp and I don't know if they'll continue to be so in the future).

How to list running screen sessions?

While joshperry's answer is correct, I find very annoying that it does not tell you the screen name (the one you set with -t option), that is actually what you use to identify a session. (not his fault, of course, that's a screen's flaw)

That's why I instead use a script such as this: ps auxw|grep -i screen|grep -v grep

How do you get a query string on Flask?

The full URL is available as request.url, and the query string is available as request.query_string.decode().

Here's an example:

from flask import request

@app.route('/adhoc_test/')
def adhoc_test():

    return request.query_string

To access an individual known param passed in the query string, you can use request.args.get('param'). This is the "right" way to do it, as far as I know.

ETA: Before you go further, you should ask yourself why you want the query string. I've never had to pull in the raw string - Flask has mechanisms for accessing it in an abstracted way. You should use those unless you have a compelling reason not to.

How to set the holo dark theme in a Android app?

According the android.com, you only need to set it in the AndroidManifest.xml file:

http://developer.android.com/guide/topics/ui/themes.html#ApplyATheme

Adding the theme attribute to your application element worked for me:

--AndroidManifest.xml--

...

<application ...

  android:theme="@android:style/Theme.Holo"/>
  ...

</application>

How can I split this comma-delimited string in Python?

How about a list?

mystring.split(",")

It might help if you could explain what kind of info we are looking at. Maybe some background info also?

EDIT:

I had a thought you might want the info in groups of two?

then try:

re.split(r"\d*,\d*", mystring)

and also if you want them into tuples

[(pair[0], pair[1]) for match in re.split(r"\d*,\d*", mystring) for pair in match.split(",")]

in a more readable form:

mylist = []
for match in re.split(r"\d*,\d*", mystring):
    for pair in match.split(",")
        mylist.append((pair[0], pair[1]))

how can the textbox width be reduced?

<input type="text" style="width:50px;"/>

HTML text input field with currency symbol

Since you can't do ::before with content: '$' on inputs and adding an absolutely positioned element adds extra html - I like do to a background SVG inline css.

It goes something like this:

input {
    width: 85px;
    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' version='1.1' height='16px' width='85px'><text x='2' y='13' fill='gray' font-size='12' font-family='arial'>$</text></svg>");
    padding-left: 12px;
}

It outputs the following:

svg dollar sign background css

Note: the code must all be on a single line. Support is pretty good in modern browsers, but be sure to test.

Can't open file 'svn/repo/db/txn-current-lock': Permission denied

I also had this problem recently, and it was the SELinux which caused it. I was trying to have the post-commit of subversion to notify Jenkins that the code has change so Jenkins would do a build and deploy to Nexus.

I had to do the following to get it to work.

1) First I checked if SELinux is enabled:

    less /selinux/enforce

This will output 1 (for on) or 0 (for off)

2) Temporary disable SELinux:

    echo 0 > /selinux/enforce

Now test see if it works now.

3) Enable SELinux:

    echo 1 > /selinux/enforce

Change the policy for SELinux.

4) First view the current configuration:

    /usr/sbin/getsebool -a | grep httpd

This will give you: httpd_can_network_connect --> off

5) Set this to on and your post-commit will work with SELinux:

    /usr/sbin/setsebool -P httpd_can_network_connect on

Now it should be working again.

Moving from one activity to another Activity in Android

Simply add your NextActivity in the Manifest.XML file

<activity
            android:name="com.example.sms1.NextActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
            </intent-filter>
        </activity>

get index of DataTable column with name

You can use DataColumn.Ordinal to get the index of the column in the DataTable. So if you need the next column as mentioned use Column.Ordinal + 1:

row[row.Table.Columns["ColumnName"].Ordinal + 1] = someOtherValue;

raw_input function in Python

The raw_input() function reads a line from input (i.e. the user) and returns a string

Python v3.x as raw_input() was renamed to input()

PEP 3111: raw_input() was renamed to input(). That is, the new input() function reads a line from sys.stdin and returns it with the trailing newline stripped. It raises EOFError if the input is terminated prematurely. To get the old behavior of input(), use eval(input()).

Ref: Docs Python 3

How to fix "Incorrect string value" errors?

I have tried all of the above solutions (which all bring valid points), but nothing was working for me.

Until I found that my MySQL table field mappings in C# was using an incorrect type: MySqlDbType.Blob . I changed it to MySqlDbType.Text and now I can write all the UTF8 symbols I want!

p.s. My MySQL table field is of the "LongText" type. However, when I autogenerated the field mappings using MyGeneration software, it automatically set the field type as MySqlDbType.Blob in C#.

Interestingly, I have been using the MySqlDbType.Blob type with UTF8 characters for many months with no trouble, until one day I tried writing a string with some specific characters in it.

Hope this helps someone who is struggling to find a reason for the error.

Get type of a generic parameter in Java with reflection

Nope, that is not possible. Due to downwards compatibility issues, Java's generics are based on type erasure, i.a. at runtime, all you have is a non-generic List object. There is some information about type parameters at runtime, but it resides in class definitions (i.e. you can ask "what generic type does this field's definition use?"), not in object instances.

Converting array to list in Java

The problem is that varargs got introduced in Java5 and unfortunately, Arrays.asList() got overloaded with a vararg version too. So Arrays.asList(spam) is understood by the Java5 compiler as a vararg parameter of int arrays.

This problem is explained in more details in Effective Java 2nd Ed., Chapter 7, Item 42.

XSLT equivalent for JSON

XSLT equivalents for JSON - a list of candidates (tools and specs)

Tools

1. XSLT

You can use XSLT for JSON with the aim of fn:json-to-xml.

This section describes facilities allowing JSON data to be processed using XSLT.

2. jq

jq is like sed for JSON data - you can use it to slice and filter and map and transform structured data with the same ease that sed, awk, grep and friends let you play with text. There are install packages for different OS.

3. jj

JJ is a command line utility that provides a fast and simple way to retrieve or update values from JSON documents. It's powered by GJSON and SJSON under the hood.

4. fx

Command-line JSON processing tool - Don't need to learn new syntax - Plain JavaScript - Formatting and highlighting - Standalone binary

5. jl

jl ("JSON lambda") is a tiny functional language for querying and manipulating JSON.

6. JOLT

JSON to JSON transformation library written in Java where the "specification" for the transform is itself a JSON document.

7. gron

Make JSON greppable! gron transforms JSON into discrete assignments to make it easier to grep for what you want and see the absolute 'path' to it. It eases the exploration of APIs that return large blobs of JSON but have terrible documentation.

8. json-e

JSON-e is a data-structure parameterization system for embedding context in JSON objects. The central idea is to treat a data structure as a "template" and transform it, using another data structure as context, to produce an output data structure.

9. JSLT

JSLT is a complete query and transformation language for JSON. The language design is inspired by jq, XPath, and XQuery.

10. JSONata

JSONata is a lightweight query and transformation language for JSON data. Inspired by the 'location path' semantics of XPath 3.1, it allows sophisticated queries to be expressed in a compact and intuitive notation.

11. JSONPath Plus

Analyse, transform, and selectively extract data from JSON documents (and JavaScript objects). jsonpath-plus expands on the original specification to add some additional operators and makes explicit some behaviors the original did not spell out.

12. json-transforms Last Commit Dec 1, 2017

Provides a recursive, pattern-matching approach to transforming JSON data. Transformations are defined as a set of rules which match the structure of a JSON object. When a match occurs, the rule emits the transformed data, optionally recursing to transform child objects.

13. json Last commit Jun 23, 2018

json is a fast CLI tool for working with JSON. It is a single-file node.js script with no external deps (other than node.js itself).

14. jsawk Last commit Mar 4, 2015

Jsawk is like awk, but for JSON. You work with an array of JSON objects read from stdin, filter them using JavaScript to produce a results array that is printed to stdout.

15. yate Last Commit Mar 13, 2017

Tests can be used as docu https://github.com/pasaran/yate/tree/master/tests

16. jsonpath-object-transform Last Commit Jan 18, 2017

Pulls data from an object literal using JSONPath and generate a new objects based on a template.

17. Stapling Last Commit Sep 16, 2013

Stapling is a JavaScript library that enables XSLT formatting for JSON objects. Instead of using a JavaScript templating engine and text/html templates, Stapling gives you the opportunity to use XSLT templates - loaded asynchronously with Ajax and then cached client side - to parse your JSON datasources.

Specs:

JSON Pointer defines a string syntax for identifying a specific value within a JavaScript Object Notation (JSON) document.

JSONPath expressions always refer to a JSON structure in the same way as XPath expression are used in combination with an XML document

JSPath for JSON is like XPath for XML."

The main source of inspiration behind JSONiq is XQuery, which has been proven so far a successful and productive query language for semi-structured data

How to set root password to null

It works for me.

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password'

Is there a concurrent List in Java's JDK?

Mostly if you need a concurrent list it is inside a model object (as you should not use abstract data types like a list to represent a node in a application model graph) or it is part of a particular service, you can synchronize the access yourself.

class MyClass {
  List<MyType> myConcurrentList = new ArrayList<>();
  void myMethod() {
    synchronzied(myConcurrentList) {
      doSomethingWithList;
    }
  }
}

Often this is enough to get you going. If you need to iterate, iterate over a copy of the list not the list itself and only synchronize the part where you copy the list not while you are iterating over it.

Also when concurrently working on a list you usually do something more than just adding or removing or copying, meaning that the operation becomes meaningful enough to warrent its own method and the list becomes member of a special class representing just this particular list with thread safe behavior.

Even if I agree that a concurrent list implementation is needed and Vector / Collections.sychronizeList(list) do not do the trick as for sure you need something like compareAndAdd or compareAndRemove or get(..., ifAbsentDo), even if you have a ConcurrentList implementation developers often introduce bugs by not considering what is the true transaction when working with a concurrent lists (and maps).

These scenarios where the transactions are too small for what the intended purpose of the interaction with a concurrent ADT (abstract data type) always lead to me hide the list in a special class and synchronizing access to this class objects method using the synchronized on the method level. Its the only way to be sure that the transactions are correct.

I have seen too many bugs to do it any other way - at least if the code is important and handles something like money or security or guarantees some quality of service measures (e.g sending message at least once and only once).

allowing only alphabets in text box using java script

:::::HTML:::::

<input type="text" onkeypress="return lettersValidate(event)" />

Only letters no spaces

::::JS::::::::

// ===================== Allow - Only Letters ===============================================================

function lettersValidate(key) {
    var keycode = (key.which) ? key.which : key.keyCode;

    if ((keycode > 64 && keycode < 91) || (keycode > 96 && keycode < 123))  
    {     
           return true;    
    }
    else
    {
        return false;
    }
         
}
 

how to check if item is selected from a comboBox in C#

I've found that using this null comparison works well:

if (Combobox.SelectedItem != null){
   //Do something
}
else{
  MessageBox.show("Please select a item");
}

This will only accept the selected item and no other value which may have been entered manually by the user which could cause validation issues.

openssl s_client -cert: Proving a client certificate was sent to the server

I know this is an old question but it does not yet appear to have an answer. I've duplicated this situation, but I'm writing the server app, so I've been able to establish what happens on the server side as well. The client sends the certificate when the server asks for it and if it has a reference to a real certificate in the s_client command line. My server application is set up to ask for a client certificate and to fail if one is not presented. Here is the command line I issue:

Yourhostname here -vvvvvvvvvv s_client -connect <hostname>:443 -cert client.pem -key cckey.pem -CAfile rootcert.pem -cipher ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH -tls1 -state

When I leave out the "-cert client.pem" part of the command the handshake fails on the server side and the s_client command fails with an error reported. I still get the report "No client certificate CA names sent" but I think that has been answered here above.

The short answer then is that the server determines whether a certificate will be sent by the client under normal operating conditions (s_client is not normal) and the failure is due to the server not recognizing the CA in the certificate presented. I'm not familiar with many situations in which two-way authentication is done although it is required for my project.

You are clearly sending a certificate. The server is clearly rejecting it.

The missing information here is the exact manner in which the certs were created and the way in which the provider loaded the cert, but that is probably all wrapped up by now.

How to use JNDI DataSource provided by Tomcat in Spring?

I found this solution very helpful in a clean way to remove xml configuration entirely.

Please check this db configuration using JNDI and spring framework. http://www.unotions.com/design/how-to-create-oracleothersql-db-configuration-using-spring-and-maven/

By this article, it explain how easy to create a db confguration based on database jndi(db/test) configuration. once you are done with configuration then all the db repositories are loaded using this jndi. I did find useful. If @Pierre has issue with this then let me know. It's complete solution to write db configuration.

How to convert from []byte to int in Go Programming

var bs []byte
value, _ := strconv.ParseInt(string(bs), 10, 64)

Error: could not find function ... in R

There are a few things you should check :

  1. Did you write the name of your function correctly? Names are case sensitive.
  2. Did you install the package that contains the function? install.packages("thePackage") (this only needs to be done once)
  3. Did you attach that package to the workspace ? require(thePackage) or library(thePackage) (this should be done every time you start a new R session)
  4. Are you using an older R version where this function didn't exist yet?

If you're not sure in which package that function is situated, you can do a few things.

  1. If you're sure you installed and attached/loaded the right package, type help.search("some.function") or ??some.function to get an information box that can tell you in which package it is contained.
  2. find and getAnywhere can also be used to locate functions.
  3. If you have no clue about the package, you can use findFn in the sos package as explained in this answer.
  4. RSiteSearch("some.function") or searching with rdocumentation or rseek are alternative ways to find the function.

Sometimes you need to use an older version of R, but run code created for a newer version. Newly added functions (eg hasName in R 3.4.0) won't be found then. If you use an older R version and want to use a newer function, you can use the package backports to make such functions available. You also find a list of functions that need to be backported on the git repo of backports. Keep in mind that R versions older than R3.0.0 are incompatible with packages built for R3.0.0 and later versions.

Mongodb find() query : return only unique values (no duplicates)

I think you can use db.collection.distinct(fields,query)

You will be able to get the distinct values in your case for NetworkID.

It should be something like this :

Db.collection.distinct('NetworkID')

Plot two graphs in same plot in R

If you are using base graphics (i.e. not lattice/ grid graphics), then you can mimic MATLAB's hold on feature by using the points/lines/polygons functions to add additional details to your plots without starting a new plot. In the case of a multiplot layout, you can use par(mfg=...) to pick which plot you add things to.

Detect merged cells in VBA Excel with MergeArea

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

You can use Range() like so:

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

Or:

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

Alternately, you can use Cells():

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

How to navigate through textfields (Next / Done Buttons)

There is a much more elegant solution which blew me away the first time I saw it. Benefits:

  • Closer to OSX textfield implementation where a textfield knows where the focus should go next
  • Does not rely on setting or using tags -- which are, IMO fragile for this use case
  • Can be extended to work with both UITextField and UITextView controls -- or any keyboard entry UI control
  • Doesn't clutter your view controller with boilerplate UITextField delegate code
  • Integrates nicely with IB and can be configured through the familiar option-drag-drop to connect outlets.

Create a UITextField subclass which has an IBOutlet property called nextField. Here's the header:

@interface SOTextField : UITextField

@property (weak, nonatomic) IBOutlet UITextField *nextField; 

@end

And here's the implementation:

@implementation SOTextField

@end

In your view controller, you'll create the -textFieldShouldReturn: delegate method:

- (BOOL)textFieldShouldReturn:(UITextField *)textField {
    if ([textField isKindOfClass:[SOTextField class]]) {
        UITextField *nextField = [(SOTextField *)textField nextField];

        if (nextField) {
            dispatch_async(dispatch_get_current_queue(), ^{
                [nextField becomeFirstResponder];
            });
        }
        else {
            [textField resignFirstResponder];
        }
    }

    return YES;
}

In IB, change your UITextFields to use the SOTextField class. Next, also in IB, set the delegate for each of the 'SOTextFields'to 'File's Owner' (which is right where you put the code for the delegate method - textFieldShouldReturn). The beauty of this design is that now you can simply right-click on any textField and assign the nextField outlet to the next SOTextField object you want to be the next responder.

Assigning nextField in IB

Moreover, you can do cool things like loop the textFields so that after the last one loses focus, the first one will receive focus again.

This can easily be extended to automatically assign the returnKeyType of the SOTextField to a UIReturnKeyNext if there is a nextField assigned -- one less thing manually configure.

Convert string to List<string> in one line?

List<string> result = names.Split(new char[] { ',' }).ToList();

Or even cleaner by Dan's suggestion:

List<string> result = names.Split(',').ToList();

How do I fix 'Invalid character value for cast specification' on a date column in flat file?

The proper data type for "2010-12-20 00:00:00.0000000" value is DATETIME2(7) / DT_DBTIME2 ().

But used data type for CYCLE_DATE field is DATETIME - DT_DATE. This means milliseconds precision with accuracy down to every third millisecond (yyyy-mm-ddThh:mi:ss.mmL where L can be 0,3 or 7).

The solution is to change CYCLE_DATE date type to DATETIME2 - DT_DBTIME2.

IDEA: javac: source release 1.7 requires target release 1.7

You need to change Java compiler version in in build config.

enter image description here

CSS: 100% width or height while keeping aspect ratio?

Its best to use auto on the dimension that should respect the aspect ratio. If you do not set the other property to auto, most browsers nowadays will assume that you want to respect the aspect ration, but not all of them (IE10 on windows phone 8 does not, for example)

width: 100%;
height: auto;

iOS Launching Settings -> Restrictions URL Scheme

Update:

prefs: will NOT work since iOS 10.

ROW_NUMBER() in MySQL

This could also be a solution:

SET @row_number = 0;

SELECT 
    (@row_number:=@row_number + 1) AS num, firstName, lastName
FROM
    employees

How to cast from List<Double> to double[] in Java?

With , you can do it this way.

double[] arr = frameList.stream().mapToDouble(Double::doubleValue).toArray(); //via method reference
double[] arr = frameList.stream().mapToDouble(d -> d).toArray(); //identity function, Java unboxes automatically to get the double value

What it does is :

  • get the Stream<Double> from the list
  • map each double instance to its primitive value, resulting in a DoubleStream
  • call toArray() to get the array.

Return list from async/await method

You need to correct your code to wait for the list to be downloaded:

List<Item> list = await GetListAsync();

Also, make sure that the method, where this code is located, has async modifier.

The reason why you get this error is that GetListAsync method returns a Task<T> which is not a completed result. As your list is downloaded asynchronously (because of Task.Run()) you need to "extract" the value from the task using the await keyword.

If you remove Task.Run(), you list will be downloaded synchronously and you don't need to use Task, async or await.

One more suggestion: you don't need to await in GetListAsync method if the only thing you do is just delegating the operation to a different thread, so you can shorten your code to the following:

private Task<List<Item>> GetListAsync(){
    return Task.Run(() => manager.GetList());
}

Can't connect to MySQL server on '127.0.0.1' (10061) (2003)

I encountered a similar problem. I am using WinNMP. When I started it, MariaDB was also not running and prompts "Can't connect to MySQL server on '127.0.0.1' (10061) (2003)" whenever I try to connect to a database.

Just want to help. For WinNMP users like me, this worked for me:

  1. Run msyqld installer located at "C:\WinNMP\bin\MariaDB\bin".
  2. Restart your WinNMP.
  3. MariaDB should be running now.

Hope this helps someone! :D

How to set JAVA_HOME in Mac permanently?

First, figure out where your java home is by running the command /usr/libexec/java_home -v <version> replacing with whatever version of OpenJDK your running.

Next use vim ~/.bash_profile to edit your bash profile. Add export JAVA_HOME="<java path>" replacing with the path to your java home found in the last step.

Finally, run the command source ~/.bash_profile

This should permanently set your JAVA_HOME environment variable.

To make sure it worked run echo $JAVA_HOME and make sure it returns the path you set

ASP.NET Temporary files cleanup

Yes, it's safe to delete these, although it may force a dynamic recompilation of any .NET applications you run on the server.

For background, see the Understanding ASP.NET dynamic compilation article on MSDN.

How can the default node version be set using NVM?

The current answers did not solve the problem for me, because I had node installed in /usr/bin/node and /usr/local/bin/node - so the system always resolved these first, and ignored the nvm version.

I solved the issue by moving the existing versions to /usr/bin/node-system and /usr/local/bin/node-system

Then I had no node command anymore, until I used nvm use :(

I solved this issue by creating a symlink to the version that would be installed by nvm.

sudo mv /usr/local/bin/node /usr/local/bin/node-system    
sudo mv /usr/bin/node /usr/bin/node-system 
nvm use node
  Now using node v12.20.1 (npm v6.14.10)
which node
  /home/paul/.nvm/versions/node/v12.20.1/bin/node
sudo ln -s /home/paul/.nvm/versions/node/v12.20.1/bin/node /usr/bin/node

Then open a new shell

node -v
  v12.20.1

How does database indexing work?

Now, let’s say that we want to run a query to find all the details of any employees who are named ‘Abc’?

SELECT * FROM Employee 
WHERE Employee_Name = 'Abc'

What would happen without an index?

Database software would literally have to look at every single row in the Employee table to see if the Employee_Name for that row is ‘Abc’. And, because we want every row with the name ‘Abc’ inside it, we can not just stop looking once we find just one row with the name ‘Abc’, because there could be other rows with the name Abc. So, every row up until the last row must be searched – which means thousands of rows in this scenario will have to be examined by the database to find the rows with the name ‘Abc’. This is what is called a full table scan

How a database index can help performance

The whole point of having an index is to speed up search queries by essentially cutting down the number of records/rows in a table that need to be examined. An index is a data structure (most commonly a B- tree) that stores the values for a specific column in a table.

How does B-trees index work?

The reason B- trees are the most popular data structure for indexes is due to the fact that they are time efficient – because look-ups, deletions, and insertions can all be done in logarithmic time. And, another major reason B- trees are more commonly used is because the data that is stored inside the B- tree can be sorted. The RDBMS typically determines which data structure is actually used for an index. But, in some scenarios with certain RDBMS’s, you can actually specify which data structure you want your database to use when you create the index itself.

How does a hash table index work?

The reason hash indexes are used is because hash tables are extremely efficient when it comes to just looking up values. So, queries that compare for equality to a string can retrieve values very fast if they use a hash index.

For instance, the query we discussed earlier could benefit from a hash index created on the Employee_Name column. The way a hash index would work is that the column value will be the key into the hash table and the actual value mapped to that key would just be a pointer to the row data in the table. Since a hash table is basically an associative array, a typical entry would look something like “Abc => 0x28939", where 0x28939 is a reference to the table row where Abc is stored in memory. Looking up a value like “Abc” in a hash table index and getting back a reference to the row in memory is obviously a lot faster than scanning the table to find all the rows with a value of “Abc” in the Employee_Name column.

The disadvantages of a hash index

Hash tables are not sorted data structures, and there are many types of queries which hash indexes can not even help with. For instance, suppose you want to find out all of the employees who are less than 40 years old. How could you do that with a hash table index? Well, it’s not possible because a hash table is only good for looking up key value pairs – which means queries that check for equality

What exactly is inside a database index? So, now you know that a database index is created on a column in a table, and that the index stores the values in that specific column. But, it is important to understand that a database index does not store the values in the other columns of the same table. For example, if we create an index on the Employee_Name column, this means that the Employee_Age and Employee_Address column values are not also stored in the index. If we did just store all the other columns in the index, then it would be just like creating another copy of the entire table – which would take up way too much space and would be very inefficient.

How does a database know when to use an index? When a query like “SELECT * FROM Employee WHERE Employee_Name = ‘Abc’ ” is run, the database will check to see if there is an index on the column(s) being queried. Assuming the Employee_Name column does have an index created on it, the database will have to decide whether it actually makes sense to use the index to find the values being searched – because there are some scenarios where it is actually less efficient to use the database index, and more efficient just to scan the entire table.

What is the cost of having a database index?

It takes up space – and the larger your table, the larger your index. Another performance hit with indexes is the fact that whenever you add, delete, or update rows in the corresponding table, the same operations will have to be done to your index. Remember that an index needs to contain the same up to the minute data as whatever is in the table column(s) that the index covers.

As a general rule, an index should only be created on a table if the data in the indexed column will be queried frequently.

See also

  1. What columns generally make good indexes?
  2. How do database indexes work

StringBuilder vs String concatenation in toString() in Java

There seems to be some debate whether using StringBuilder is still needed with current compilers. So I thought I'll give my 2 cents of experience.

I have a JDBC result set of 10k records (yes, I need all of them in one batch.) Using the + operator takes about 5 minutes on my machine with Java 1.8. Using stringBuilder.append("") takes less than a second for the same query.

So the difference is huge. Inside a loop StringBuilder is much faster.

JS - window.history - Delete a state

You may have moved on by now, but... as far as I know there's no way to delete a history entry (or state).

One option I've been looking into is to handle the history yourself in JavaScript and use the window.history object as a carrier of sorts.

Basically, when the page first loads you create your custom history object (we'll go with an array here, but use whatever makes sense for your situation), then do your initial pushState. I would pass your custom history object as the state object, as it may come in handy if you also need to handle users navigating away from your app and coming back later.

var myHistory = [];

function pageLoad() {
    window.history.pushState(myHistory, "<name>", "<url>");

    //Load page data.
}

Now when you navigate, you add to your own history object (or don't - the history is now in your hands!) and use replaceState to keep the browser out of the loop.

function nav_to_details() {
    myHistory.push("page_im_on_now");
    window.history.replaceState(myHistory, "<name>", "<url>");

    //Load page data.
}

When the user navigates backwards, they'll be hitting your "base" state (your state object will be null) and you can handle the navigation according to your custom history object. Afterward, you do another pushState.

function on_popState() {
    // Note that some browsers fire popState on initial load,
    // so you should check your state object and handle things accordingly.
    // (I did not do that in these examples!)

    if (myHistory.length > 0) {
        var pg = myHistory.pop();
        window.history.pushState(myHistory, "<name>", "<url>");

        //Load page data for "pg".
    } else {
        //No "history" - let them exit or keep them in the app.
    }
}

The user will never be able to navigate forward using their browser buttons because they are always on the newest page.

From the browser's perspective, every time they go "back", they've immediately pushed forward again.

From the user's perspective, they're able to navigate backwards through the pages but not forward (basically simulating the smartphone "page stack" model).

From the developer's perspective, you now have a high level of control over how the user navigates through your application, while still allowing them to use the familiar navigation buttons on their browser. You can add/remove items from anywhere in the history chain as you please. If you use objects in your history array, you can track extra information about the pages as well (like field contents and whatnot).

If you need to handle user-initiated navigation (like the user changing the URL in a hash-based navigation scheme), then you might use a slightly different approach like...

var myHistory = [];

function pageLoad() {
    // When the user first hits your page...
    // Check the state to see what's going on.

    if (window.history.state === null) {
        // If the state is null, this is a NEW navigation,
        //    the user has navigated to your page directly (not using back/forward).

        // First we establish a "back" page to catch backward navigation.
        window.history.replaceState(
            { isBackPage: true },
            "<back>",
            "<back>"
        );

        // Then push an "app" page on top of that - this is where the user will sit.
        // (As browsers vary, it might be safer to put this in a short setTimeout).
        window.history.pushState(
            { isBackPage: false },
            "<name>",
            "<url>"
        );

        // We also need to start our history tracking.
        myHistory.push("<whatever>");

        return;
    }

    // If the state is NOT null, then the user is returning to our app via history navigation.

    // (Load up the page based on the last entry of myHistory here)

    if (window.history.state.isBackPage) {
        // If the user came into our app via the back page,
        //     you can either push them forward one more step or just use pushState as above.

        window.history.go(1);
        // or window.history.pushState({ isBackPage: false }, "<name>", "<url>");
    }

    setTimeout(function() {
        // Add our popstate event listener - doing it here should remove
        //     the issue of dealing with the browser firing it on initial page load.
        window.addEventListener("popstate", on_popstate);
    }, 100);
}

function on_popstate(e) {
    if (e.state === null) {
        // If there's no state at all, then the user must have navigated to a new hash.

        // <Look at what they've done, maybe by reading the hash from the URL>
        // <Change/load the new page and push it onto the myHistory stack>
        // <Alternatively, ignore their navigation attempt by NOT loading anything new or adding to myHistory>

        // Undo what they've done (as far as navigation) by kicking them backwards to the "app" page
        window.history.go(-1);

        // Optionally, you can throw another replaceState in here, e.g. if you want to change the visible URL.
        // This would also prevent them from using the "forward" button to return to the new hash.
        window.history.replaceState(
            { isBackPage: false },
            "<new name>",
            "<new url>"
        );
    } else {
        if (e.state.isBackPage) {
            // If there is state and it's the 'back' page...

            if (myHistory.length > 0) {
                // Pull/load the page from our custom history...
                var pg = myHistory.pop();
                // <load/render/whatever>

                // And push them to our "app" page again
                window.history.pushState(
                    { isBackPage: false },
                    "<name>",
                    "<url>"
                );
            } else {
                // No more history - let them exit or keep them in the app.
            }
        }

        // Implied 'else' here - if there is state and it's NOT the 'back' page
        //     then we can ignore it since we're already on the page we want.
        //     (This is the case when we push the user back with window.history.go(-1) above)
    }
}

Get and Set a Single Cookie with Node.js HTTP Server

As an enhancement to @Corey Hart's answer, I've rewritten the parseCookies() using:

Here's the working example:

let http = require('http');

function parseCookies(str) {
  let rx = /([^;=\s]*)=([^;]*)/g;
  let obj = { };
  for ( let m ; m = rx.exec(str) ; )
    obj[ m[1] ] = decodeURIComponent( m[2] );
  return obj;
}

function stringifyCookies(cookies) {
  return Object.entries( cookies )
    .map( ([k,v]) => k + '=' + encodeURIComponent(v) )
    .join( '; ');
}

http.createServer(function ( request, response ) {
  let cookies = parseCookies( request.headers.cookie );
  console.log( 'Input cookies: ', cookies );
  cookies.search = 'google';
  if ( cookies.counter )
    cookies.counter++;
  else
    cookies.counter = 1;
  console.log( 'Output cookies: ', cookies );
  response.writeHead( 200, {
    'Set-Cookie': stringifyCookies(cookies),
    'Content-Type': 'text/plain'
  } );
  response.end('Hello World\n');
} ).listen(1234);

I also note that the OP uses the http module. If the OP was using restify, he can make use of restify-cookies:

var CookieParser = require('restify-cookies');
var Restify = require('restify');
var server = Restify.createServer();
server.use(CookieParser.parse);
server.get('/', function(req, res, next){
  var cookies = req.cookies; // Gets read-only cookies from the request
  res.setCookie('my-new-cookie', 'Hi There'); // Adds a new cookie to the response
  res.send(JSON.stringify(cookies));
});
server.listen(8080);

How to search for a part of a word with ElasticSearch

While there are a lot of answers which focuses on solving the issue at hand but don't talk much about the various trade-off which someone needs to make before choosing a particular answer. So let me try to add a few more details on this perspective.

Partial search is now a day a very common and important feature and if not implemented properly can lead to poor user experience and bad performance, so first know your application function and non-function requirement related to this feature which I talked about in my this detailed SO answer.

Now there are various approaches, like query time, index time, completion suggester and search as you type data-types added in recent version of elasticsarch.

Now people who quickly want to just implement a solution can use below end to end working solution.

Index mapping

{
  "settings": {
    "analysis": {
      "filter": {
        "autocomplete_filter": {
          "type": "ngram",
          "min_gram": 1,
          "max_gram": 10
        }
      },
      "analyzer": {
        "autocomplete": { 
          "type": "custom",
          "tokenizer": "standard",
          "filter": [
            "lowercase",
            "autocomplete_filter"
          ]
        }
      }
    },
    "index.max_ngram_diff" : 10
  },
  "mappings": {
    "properties": {
      "title": {
        "type": "text",
        "analyzer": "autocomplete", 
        "search_analyzer": "standard" 
      }
    }
  }
}

Index given sample docs

{
  "title" : "John Doeman"
  
}

{
  "title" : "Jane Doewoman"
  
}

{
  "title" : "Jimmy Jackal"
  
}

And search query

{
    "query": {
        "match": {
            "title": "Doe"
        }
    }
}

which returns expected search results

 "hits": [
            {
                "_index": "6467067",
                "_type": "_doc",
                "_id": "1",
                "_score": 0.76718915,
                "_source": {
                    "title": "John Doeman"
                }
            },
            {
                "_index": "6467067",
                "_type": "_doc",
                "_id": "2",
                "_score": 0.76718915,
                "_source": {
                    "title": "Jane Doewoman"
                }
            }
        ]

How to implement oauth2 server in ASP.NET MVC 5 and WEB API 2

I also struggled finding articles on how to just generate the token part. I never found one and wrote my own. So if it helps:

The things to do are:

  • Create a new web application
  • Install the following NuGet packages:
    • Microsoft.Owin
    • Microsoft.Owin.Host.SystemWeb
    • Microsoft.Owin.Security.OAuth
    • Microsoft.AspNet.Identity.Owin
  • Add a OWIN startup class

Then create a HTML and a JavaScript (index.js) file with these contents:

var loginData = 'grant_type=password&[email protected]&password=test123';

var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function () {
    if (xmlhttp.readyState === 4 && xmlhttp.status === 200) {
        alert(xmlhttp.responseText);
    }
}
xmlhttp.open("POST", "/token", true);
xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlhttp.send(loginData);
<!DOCTYPE html>
<html>
<head>
    <title></title>
</head>
<body>
    <script type="text/javascript" src="index.js"></script>
</body>
</html>

The OWIN startup class should have this content:

using System;
using System.Security.Claims;
using Microsoft.Owin;
using Microsoft.Owin.Security.OAuth;
using OAuth20;
using Owin;

[assembly: OwinStartup(typeof(Startup))]

namespace OAuth20
{
    public class Startup
    {
        public static OAuthAuthorizationServerOptions OAuthOptions { get; private set; }

        public void Configuration(IAppBuilder app)
        {
            OAuthOptions = new OAuthAuthorizationServerOptions()
            {
                TokenEndpointPath = new PathString("/token"),
                Provider = new OAuthAuthorizationServerProvider()
                {
                    OnValidateClientAuthentication = async (context) =>
                    {
                        context.Validated();
                    },
                    OnGrantResourceOwnerCredentials = async (context) =>
                    {
                        if (context.UserName == "[email protected]" && context.Password == "test123")
                        {
                            ClaimsIdentity oAuthIdentity = new ClaimsIdentity(context.Options.AuthenticationType);
                            context.Validated(oAuthIdentity);
                        }
                    }
                },
                AllowInsecureHttp = true,
                AccessTokenExpireTimeSpan = TimeSpan.FromDays(1)
            };

            app.UseOAuthBearerTokens(OAuthOptions);
        }
    }
}

Run your project. The token should be displayed in the pop-up.

How to delete row in gridview using rowdeleting event?

protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
    GridViewRow row = (GridViewRow)GridView1.Rows[e.RowIndex];
    SqlCommand cmd = new SqlCommand("Delete From userTable (userName,age,birthPLace)");
    GridView1.DataBind();
}

How to create an Oracle sequence starting with max value from a table?

Bear in mid, the MAX value will only be the maximum of committed values. It might return 1234, and you may need to consider that someone has already inserted 1235 but not committed.

How to check if mysql database exists

A very simple BASH-one-liner:

mysqlshow | grep dbname

Interface vs Base class

Also keep in mind not to get swept away in OO (see blog) and always model objects based on behavior required, if you were designing an app where the only behavior you required was a generic name and species for an animal then you would only need one class Animal with a property for the name, instead of millions of classes for every possible animal in the world.

How to do SQL Like % in Linq?

Well indexOf works for me too

var result = from c in SampleList
where c.LongName.IndexOf(SearchQuery) >= 0
select c;

Multiline for WPF TextBox

Contrary to @Andre Luus, setting Height="Auto" will not make the TextBox stretch. The solution I found was to set VerticalAlignment="Stretch"

Refresh Page and Keep Scroll Position

If you don't want to use local storage then you could attach the y position of the page to the url and grab it with js on load and set the page offset to the get param you passed in, i.e.:

//code to refresh the page
var page_y = $( document ).scrollTop();
window.location.href = window.location.href + '?page_y=' + page_y;


//code to handle setting page offset on load
$(function() {
    if ( window.location.href.indexOf( 'page_y' ) != -1 ) {
        //gets the number from end of url
        var match = window.location.href.split('?')[1].match( /\d+$/ );
        var page_y = match[0];

        //sets the page offset 
        $( 'html, body' ).scrollTop( page_y );
    }
});

How to pretty print XML from the command line?

xmllint support formatting in-place:

for f in *.xml; do xmllint -o $f --format $f; done

As Daniel Veillard has written:

I think xmllint -o tst.xml --format tst.xml should be safe as the parser will fully load the input into a tree before opening the output to serialize it.

Indent level is controlled by XMLLINT_INDENT environment variable which is by default 2 spaces. Example how to change indent to 4 spaces:

XMLLINT_INDENT='    '  xmllint -o out.xml --format in.xml

You may have lack with --recover option when you XML documents are broken. Or try weak HTML parser with strict XML output:

xmllint --html --xmlout <in.xml >out.xml

--nsclean, --nonet, --nocdata, --noblanks etc may be useful. Read man page.

apt-get install libxml2-utils
apt-cyg install libxml2
brew install libxml2

Extract elements of list at odd positions

Solution

Yes, you can:

l = L[1::2]

And this is all. The result will contain the elements placed on the following positions (0-based, so first element is at position 0, second at 1 etc.):

1, 3, 5

so the result (actual numbers) will be:

2, 4, 6

Explanation

The [1::2] at the end is just a notation for list slicing. Usually it is in the following form:

some_list[start:stop:step]

If we omitted start, the default (0) would be used. So the first element (at position 0, because the indexes are 0-based) would be selected. In this case the second element will be selected.

Because the second element is omitted, the default is being used (the end of the list). So the list is being iterated from the second element to the end.

We also provided third argument (step) which is 2. Which means that one element will be selected, the next will be skipped, and so on...

So, to sum up, in this case [1::2] means:

  1. take the second element (which, by the way, is an odd element, if you judge from the index),
  2. skip one element (because we have step=2, so we are skipping one, as a contrary to step=1 which is default),
  3. take the next element,
  4. Repeat steps 2.-3. until the end of the list is reached,

EDIT: @PreetKukreti gave a link for another explanation on Python's list slicing notation. See here: Explain Python's slice notation

Extras - replacing counter with enumerate()

In your code, you explicitly create and increase the counter. In Python this is not necessary, as you can enumerate through some iterable using enumerate():

for count, i in enumerate(L):
    if count % 2 == 1:
        l.append(i)

The above serves exactly the same purpose as the code you were using:

count = 0
for i in L:
    if count % 2 == 1:
        l.append(i)
    count += 1

More on emulating for loops with counter in Python: Accessing the index in Python 'for' loops

Alternative Windows shells, besides CMD.EXE?

Try Clink. It's awesome, especially if you are used to bash keybindings and features.

(As already pointed out - there is a similar question: Is there a better Windows Console Window?)

Watch multiple $scope attributes

Angular introduced $watchGroup in version 1.3 using which we can watch multiple variables, with a single $watchGroup block $watchGroup takes array as first parameter in which we can include all of our variables to watch.

$scope.$watchGroup(['var1','var2'],function(newVals,oldVals){
   console.log("new value of var1 = " newVals[0]);
   console.log("new value of var2 = " newVals[1]);
   console.log("old value of var1 = " oldVals[0]);
   console.log("old value of var2 = " oldVals[1]);
});

Deploying just HTML, CSS webpage to Tomcat

There is no real need to create a war to run it from Tomcat. You can follow these steps

  1. Create a folder in webapps folder e.g. MyApp

  2. Put your html and css in that folder and name the html file, which you want to be the starting page for your application, index.html

  3. Start tomcat and point your browser to url "http://localhost:8080/MyApp". Your index.html page will pop up in the browser

What are the Differences Between "php artisan dump-autoload" and "composer dump-autoload"?

Laravel's Autoload is a bit different:

1) It will in fact use Composer for some stuff

2) It will call Composer with the optimize flag

3) It will 'recompile' loads of files creating the huge bootstrap/compiled.php

4) And also will find all of your Workbench packages and composer dump-autoload them, one by one.

How to upgrade Git on Windows to the latest version?

Just run:

$ git update-git-for-windows

Android Emulator Error Message: "PANIC: Missing emulator engine program for 'x86' CPUS."

Simply follow the below steps specific to mac:

  1. go to: /Users/{username}/Library/Android/sdk/emulator

  2. ./emulator -list-avds

  3. ./emulator @avdName

automatically execute an Excel macro on a cell change

Your code looks pretty good.

Be careful, however, for your call to Range("H5") is a shortcut command to Application.Range("H5"), which is equivalent to Application.ActiveSheet.Range("H5"). This could be fine, if the only changes are user-changes -- which is the most typical -- but it is possible for the worksheet's cell values to change when it is not the active sheet via programmatic changes, e.g. VBA.

With this in mind, I would utilize Target.Worksheet.Range("H5"):

Private Sub Worksheet_Change(ByVal Target As Range)
    If Not Intersect(Target, Target.Worksheet.Range("H5")) Is Nothing Then Macro
End Sub

Or you can use Me.Range("H5"), if the event handler is on the code page for the worksheet in question (it usually is):

Private Sub Worksheet_Change(ByVal Target As Range)
    If Not Intersect(Target, Me.Range("H5")) Is Nothing Then Macro
End Sub

Hope this helps...

Text in a flex container doesn't wrap in IE11

The only way I have 100% consistently been able to avoid this flex-direction column bug is to use a min-width media query to assign a max-width to the child element on desktop sized screens.

.parent {
    display: flex;
    flex-direction: column;
}

//a media query targeting desktop sort of sized screens
@media screen and (min-width: 980px) {
    .child {
        display: block;
        max-width: 500px;//maximimum width of the element on a desktop sized screen
    }
}

You will need to set naturally inline child elements (eg. <span> or <a>) to something other than inline (mainly display:block or display:inline-block) for the fix to work.

Eclipse: Java was started but returned error code=13

This error occurs because your Eclipse version is 64-bit. You should download and install 64-bit JRE and add the path to it in eclipse.ini. For example:

...
--launcher.appendVmargs
-vm
C:\Program Files\Java\jre1.8.0_45\bin\javaw.exe
-vmargs
...

Note: The -vm parameter should be just before -vmargs and the path should be on a separate line. It should be the full path to the javaw.exe file. Do not enclose the path in double quotes (").

If your Eclipse is 32-bit, install a 32-bit JRE and use the path to its javaw.exe file.

C# Creating an array of arrays

I think you may be looking for Jagged Arrays, which are different from multi-dimensional arrays (as you are using in your example) in C#. Converting the arrays in your declarations to jagged arrays should make it work. However, you'll still need to use two loops to iterate over all the items in the 2D jagged array.

How to stop "setInterval"

Store the return of setInterval in a variable, and use it later to clear the interval.

var timer = null;
$("textarea").blur(function(){
    timer = window.setInterval(function(){ ... whatever ... }, 2000);
}).focus(function(){
    if(timer){
       window.clearInterval(timer);
       timer = null
    }
});

How to reset the bootstrap modal when it gets closed and open it fresh again?

Just reset any content manually when modal is hidden:

$(".modal").on("hidden.bs.modal", function(){
    $(".modal-body1").html("");
});

There is more events. More about them here

_x000D_
_x000D_
$(document).ready(function() {_x000D_
  $(".modal").on("hidden.bs.modal", function() {_x000D_
    $(".modal-body1").html("Where did he go?!?!?!");_x000D_
  });_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/css/bootstrap.min.css" />_x000D_
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/js/bootstrap.min.js"></script>_x000D_
_x000D_
<button type="button" class="btn btn-primary btn-lg" data-toggle="modal" data-target="#myModal">_x000D_
  Launch modal_x000D_
</button>_x000D_
_x000D_
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">_x000D_
  <div class="modal-dialog">_x000D_
    <div class="modal-content">_x000D_
      <div class="modal-header">_x000D_
        <button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;</span><span class="sr-only">Close</span>_x000D_
        </button>_x000D_
        <h4 class="modal-title" id="myModalLabel">Modal title</h4>_x000D_
      </div>_x000D_
      <div class="modal-body">_x000D_
        <div class='modal-body1'>_x000D_
          <h3>Close and open, I will be gone!</h3>_x000D_
        </div>_x000D_
      </div>_x000D_
      <div class="modal-footer">_x000D_
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>_x000D_
      </div>_x000D_
    </div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

.htaccess File Options -Indexes on Subdirectories

The correct answer is

Options -Indexes

You must have been thinking of

AllowOverride All

https://httpd.apache.org/docs/2.2/howto/htaccess.html

.htaccess files (or "distributed configuration files") provide a way to make configuration changes on a per-directory basis. A file, containing one or more configuration directives, is placed in a particular document directory, and the directives apply to that directory, and all subdirectories thereof.

TypeError: 'list' object cannot be interpreted as an integer

You should do this instead:

for i in myList:
    # etc.

That is, remove the range() part. The range() function is used to generate a sequence of numbers, and it receives as parameters the limits to generate the range, it won't work to pass a list as parameter. For iterating over the list, just write the loop as shown above.

Numpy - Replace a number with NaN

A[A==NDV]=numpy.nan

A==NDV will produce a boolean array that can be used as an index for A

How to make MySQL handle UTF-8 properly

These tips on MySQL and UTF-8 may be helpful. Unfortunately, they don't constitute a full solution, just common gotchas.

Add line break to ::after or ::before pseudo-element content

<p>Break sentence after the comma,<span class="mbr"> </span>in case of mobile version.</p>
<p>Break sentence after the comma,<span class="dbr"> </span>in case of desktop version.</p>

The .mbr and .dbr classes can simulate line-break behavior using CSS display:table. Useful if you want to replace real <br />.

Check out this demo Codepen: https://codepen.io/Marko36/pen/RBweYY,
and this post on responsive site use: Responsive line-breaks: simulate <br /> at given breakpoints.

what's the default value of char?

Default value of Character is Character.MIN_VALUE which internally represented as MIN_VALUE = '\u0000'

Additionally, you can check if the character field contains default value as

Character DEFAULT_CHAR = new Character(Character.MIN_VALUE);
if (DEFAULT_CHAR.compareTo((Character) value) == 0)
{

}

SyntaxError: multiple statements found while compiling a single statement

A (partial) practical work-around is to put things into a throw-away function.

Pasting

x = 1
x += 1
print(x)

results in

>>> x = 1
x += 1
print(x)
  File "<stdin>", line 1
    x += 1
print(x)

    ^
SyntaxError: multiple statements found while compiling a single statement
>>>

However, pasting

def abc():
  x = 1
  x += 1
  print(x)

works:

>>> def abc():
  x = 1
  x += 1
  print(x)
>>> abc()
2
>>>

Of course, this is OK for a quick one-off, won't work for everything you might want to do, etc. But then, going to ipython / jupyter qtconsole is probably the next simplest option.

Java: Retrieving an element from a HashSet

First of all convert your set to Array. Then, get item by index of array .

Set uniqueItem = new HashSet() ;
uniqueItem.add("0");
uniqueItem.add("1");
uniqueItem.add("0");

Object[] arrayItem = uniqueItem.toArray(); 
for(int i = 0; i < uniqueItem.size();i++){
    System.out.println("Item "+i+" "+arrayItem[i].toString());
}

How do I get total physical memory size using PowerShell without WMI?

If you don't want to use WMI, I can suggest systeminfo.exe. But, there may be a better way to do that.

(systeminfo | Select-String 'Total Physical Memory:').ToString().Split(':')[1].Trim()

MySQL: determine which database is selected?

@mysql_result(mysql_query("SELECT DATABASE();"),0)

If no database selected, or there is no connection it returns NULL otherwise the name of the selected database.

RequestDispatcher.forward() vs HttpServletResponse.sendRedirect()

SendRedirect() will search the content between the servers. it is slow because it has to intimate the browser by sending the URL of the content. then browser will create a new request for the content within the same server or in another one.

RquestDispatcher is for searching the content within the server i think. its the server side process and it is faster compare to the SendRedirect() method. but the thing is that it will not intimate the browser in which server it is searching the required date or content, neither it will not ask the browser to change the URL in URL tab. so it causes little inconvenience to the user.

grabbing first row in a mysql query only

You can get the total number of rows containing a specific name using:

SELECT COUNT(*) FROM tbl_foo WHERE name = 'sarmen'

Given the count, you can now get the nth row using:

SELECT * FROM tbl_foo WHERE name = 'sarmen' LIMIT (n - 1), 1

Where 1 <= n <= COUNT(*) from the first query.

Example:

getting the 3rd row

SELECT * FROM tbl_foo WHERE name = 'sarmen' LIMIT 2, 1

What is the advantage of using heredoc in PHP?

Some IDEs highlight the code in heredoc strings automatically - which makes using heredoc for XML or HTML visually appealing.

I personally like it for longer parts of i.e. XML since I don't have to care about quoting quote characters and can simply paste the XML.

Pass parameter from a batch file to a PowerShell script

The answer from @Emiliano is excellent. You can also pass named parameters like so:

powershell.exe -Command 'G:\Karan\PowerShell_Scripts\START_DEV.ps1' -NamedParam1 "SomeDataA" -NamedParam2 "SomeData2"

Note the parameters are outside the command call, and you'll use:

[parameter(Mandatory=$false)]
  [string]$NamedParam1,
[parameter(Mandatory=$false)]
  [string]$NamedParam2

getActionBar() returns null

I had the same problem and one of the solutions was to use setContentView() before calling getActionBar().

But there was another thing that fixed the problem. I specified theme for the application to be @android:style/Theme.Holo.Light.

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@android:style/Theme.Holo.Light" >
    ...
</application>

I think any theme, which has <item name="android:windowActionBar">true</item> in it, can be used.

Resolving IP Address from hostname with PowerShell

You could use vcsjones's solution, but this might cause problems with further ping/tracert commands, since the result is an array of addresses and you need only one.

To select the proper address, Send an ICMP echo request and read the Address property of the echo reply:

$ping = New-Object System.Net.NetworkInformation.Ping
$ip = $($ping.Send("yourhosthere").Address).IPAddressToString

Though the remarks from the documentation say:

The Address returned by any of the Send overloads can originate from a malicious remote computer. Do not connect to the remote computer using this address. Use DNS to determine the IP address of the machine to which you want to connect.

Get last n lines of a file, similar to tail

abc = "2018-06-16 04:45:18.68"
filename = "abc.txt"
with open(filename) as myFile:
    for num, line in enumerate(myFile, 1):
        if abc in line:
            lastline = num
print "last occurance of work at file is in "+str(lastline) 

Java: Array with loop

int[] nums = new int[100];

int sum = 0;

// Fill it with numbers using a for-loop for (int i = 0; i < nums.length; i++)

{ 
     nums[i] = i + 1;
    sum += n;
}

System.out.println(sum);

How do I count cells that are between two numbers in Excel?

Example-

For cells containing the values between 21-31, the formula is:

=COUNTIF(M$7:M$83,">21")-COUNTIF(M$7:M$83,">31")

Weird PHP error: 'Can't use function return value in write context'

This can happen in more than one scenario, below is a list of well known scenarios :

// calling empty on a function 
empty(myFunction($myVariable)); // the return value of myFunction should be saved into a variable
// then you can use empty on your variable

// using parenthesis to access an element of an array, parenthesis are used to call a function

if (isset($_POST('sms_code') == TRUE ) { ...
// that should be if(isset($_POST['sms_code']) == TRUE)

This also could be triggered when we try to increment the result of a function like below:

$myCounter = '356';

$myCounter = intVal($myCounter)++; // we try to increment the result of the intVal...
// like the first case, the ++ needs to be called on a variable, a variable should hold the the return of the function then we can call ++ operator on it.

Want to move a particular div to right

You can use float on that particular div, e.g.

<div style="float:right;">

Float the div you want more space to have to the left as well:

<div style="float:left;">

If all else fails give the div on the right position:absolute and then move it as right as you want it to be.

<div style="position:absolute; left:-500px; top:30px;"> 

etc. Obviously put the style in a seperate stylesheet but this is just a quicker example.

JSON date to Java date?

Note that SimpleDateFormat format pattern Z is for RFC 822 time zone and pattern X is for ISO 8601 (this standard supports single letter time zone names like Z for Zulu).

So new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSX") produces a format that can parse both "2013-03-11T01:38:18.309Z" and "2013-03-11T01:38:18.309+0000" and will give you the same result.

Unfortunately, as far as I can tell, you can't get this format to generate the Z for Zulu version, which is annoying.

I actually have more trouble on the JavaScript side to deal with both formats.

How to terminate a process in vbscript

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

Run the process with .Exec.

Then wait for 4 seconds.

After that kill this process.

when I run mockito test occurs WrongTypeOfReturnValue Exception

Very interested problem. In my case this problem was caused when I tried to debug my tests on this similar line:

Boolean fooBar;
when(bar.getFoo()).thenReturn(fooBar);

The important note is that the tests were running correctly without debugging.

In any way, when I replaced above code with below code snippet then I was able to debug the problem line without problems.

doReturn(fooBar).when(bar).getFoo();

jQuery: Clearing Form Inputs

Demo : http://jsfiddle.net/xavi3r/D3prt/

$(':input','#myform')
  .not(':button, :submit, :reset, :hidden')
  .val('')
  .removeAttr('checked')
  .removeAttr('selected');

Original Answer: Resetting a multi-stage form with jQuery


Mike's suggestion (from the comments) to keep checkbox and selects intact!

Warning: If you're creating elements (so they're not in the dom), replace :hidden with [type=hidden] or all fields will be ignored!

$(':input','#myform')
  .removeAttr('checked')
  .removeAttr('selected')
  .not(':button, :submit, :reset, :hidden, :radio, :checkbox')
  .val('');

How to configure postgresql for the first time?

Just browse up to your installation's directory and execute this file "pg_env.bat", so after go at bin folder and execute pgAdmin.exe. This must work no doubt!

How to get selected value from Dropdown list in JavaScript

Direct value should work just fine:

var sv = sel.value;
alert(sv);

The only reason your code might fail is when there is no item selected, then the selectedIndex returns -1 and the code breaks.

Way to insert text having ' (apostrophe) into a SQL table

INSERT INTO exampleTbl VALUES('he doesn''t work for me')

If you're adding a record through ASP.NET, you can use the SqlParameter object to pass in values so you don't have to worry about the apostrophe's that users enter in.

Find and copy files

The reason for that error is that you are trying to copy a folder which requires -r option also to cp Thanks

Blocking device rotation on mobile web pages

In JavaScript-enabled browsers it should be easy to determine if the screen is in landscape or portrait mode and compensate using CSS. It may be helpful to give users the option to disable this or at least warn them that device rotation will not work properly.

Edit

The easiest way to detect the orientation of the browser is to check the width of the browser versus the height of the browser. This also has the advantage that you'll know if the game is being played on a device that is naturally oriented in landscape mode (as some mobile devices like the PSP are). This makes more sense than trying to disable device rotation.

Edit 2

Daz has shown how you can detect device orientation, but detecting orientation is only half of the solution. If want to reverse the automatic orientation change, you'll need to rotate everything either 90° or 270°/-90°, e.g.

$(window).bind('orientationchange resize', function(event){
  if (event.orientation) {
    if (event.orientation == 'landscape') {
      if (window.rotation == 90) {
        rotate(this, -90);
      } else {
        rotate(this, 90);
      }
    }
  }
});

function rotate(el, degs) {
  iedegs = degs/90;
  if (iedegs < 0) iedegs += 4;
  transform = 'rotate('+degs+'deg)';
  iefilter = 'progid:DXImageTransform.Microsoft.BasicImage(rotation='+iedegs+')';
  styles = {
    transform: transform,
    '-webkit-transform': transform,
    '-moz-transform': transform,
    '-o-transform': transform,
    filter: iefilter,
    '-ms-filter': iefilter
  };
  $(el).css(styles);
}

Note: if you want to rotate in IE by an arbitrary angle (for other purposes), you'll need to use matrix transform, e.g.

rads = degs * Math.PI / 180;
m11 = m22 = Math.cos(rads);
m21 = Math.sin(rads);
m12 = -m21;
iefilter = "progid:DXImageTransform.Microsoft.Matrix("
  + "M11 = " + m11 + ", "
  + "M12 = " + m12 + ", "
  + "M21 = " + m21 + ", "
  + "M22 = " + m22 + ", sizingMethod = 'auto expand')";
styles['filter'] = styles['-ms-filter'] = iefilter;

—or use CSS Sandpaper. Also, this applies the rotation style to the window object, which I've never actually tested and don't know if works or not. You may need to apply the style to a document element instead.

Anyway, I would still recommend simply displaying a message that asks the user to play the game in portrait mode.

Why does viewWillAppear not get called when an app comes back from the background?

The method viewWillAppear should be taken in the context of what is going on in your own application, and not in the context of your application being placed in the foreground when you switch back to it from another app.

In other words, if someone looks at another application or takes a phone call, then switches back to your app which was earlier on backgrounded, your UIViewController which was already visible when you left your app 'doesn't care' so to speak -- as far as it is concerned, it's never disappeared and it's still visible -- and so viewWillAppear isn't called.

I recommend against calling the viewWillAppear yourself -- it has a specific meaning which you shouldn't subvert! A refactoring you can do to achieve the same effect might be as follows:

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    [self doMyLayoutStuff:self];
}

- (void)doMyLayoutStuff:(id)sender {
    // stuff
}

Then also you trigger doMyLayoutStuff from the appropriate notification:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(doMyLayoutStuff:) name:UIApplicationDidChangeStatusBarFrameNotification object:self];

There's no out of the box way to tell which is the 'current' UIViewController by the way. But you can find ways around that, e.g. there are delegate methods of UINavigationController for finding out when a UIViewController is presented therein. You could use such a thing to track the latest UIViewController which has been presented.

Update

If you layout out UIs with the appropriate autoresizing masks on the various bits, sometimes you don't even need to deal with the 'manual' laying out of your UI - it just gets dealt with...

how to display excel sheet in html page

Depending on if you want it to automatically update or not, you can just save the excel spreadsheet as a PDF then embed the PDF as an object -

It appears you don't have a PDF plugin for this browser, but you can click here to download the PDF file.

It's the best way I have found for uploading.

multiprocessing: How do I share a dict among multiple processes?

In addition to @senderle's here, some might also be wondering how to use the functionality of multiprocessing.Pool.

The nice thing is that there is a .Pool() method to the manager instance that mimics all the familiar API of the top-level multiprocessing.

from itertools import repeat
import multiprocessing as mp
import os
import pprint

def f(d: dict) -> None:
    pid = os.getpid()
    d[pid] = "Hi, I was written by process %d" % pid

if __name__ == '__main__':
    with mp.Manager() as manager:
        d = manager.dict()
        with manager.Pool() as pool:
            pool.map(f, repeat(d, 10))
        # `d` is a DictProxy object that can be converted to dict
        pprint.pprint(dict(d))

Output:

$ python3 mul.py 
{22562: 'Hi, I was written by process 22562',
 22563: 'Hi, I was written by process 22563',
 22564: 'Hi, I was written by process 22564',
 22565: 'Hi, I was written by process 22565',
 22566: 'Hi, I was written by process 22566',
 22567: 'Hi, I was written by process 22567',
 22568: 'Hi, I was written by process 22568',
 22569: 'Hi, I was written by process 22569',
 22570: 'Hi, I was written by process 22570',
 22571: 'Hi, I was written by process 22571'}

This is a slightly different example where each process just logs its process ID to the global DictProxy object d.

The real difference between "int" and "unsigned int"

The printf function interprets the value that you pass it according to the format specifier in a matching position. If you tell printf that you pass an int, but pass unsigned instead, printf would re-interpret one as the other, and print the results that you see.

ERROR 403 in loading resources like CSS and JS in my index.php

Find out the web server user

open up terminal and type lsof -i tcp:80

This will show you the user of the web server process Here is an example from a raspberry pi running debian:

COMMAND   PID     USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
apache2  7478 www-data    3u  IPv4 450666      0t0  TCP *:http (LISTEN)
apache2  7664 www-data    3u  IPv4 450666      0t0  TCP *:http (LISTEN)
apache2  7794 www-data    3u  IPv4 450666      0t0  TCP *:http (LISTEN)

The user is www-data

If you give ownership of the web files to the web server:

chown www-data:www-data -R /opt/lamp/htdocs

And chmod 755 for good measure:

chmod 755 -R /opt/lamp/htdocs

Let me know how you go, maybe you need to use 'sudo' before the command, i.e. sudo chown www-data:www-data -R /opt/lamp/htdocs

if it doesn't work, please give us the output of: ls -al /opt/lamp/htdocs

Transparent background on winforms?

I tried almost all of this. but still couldn't work. Finally I found it was because of 24bitmap problems. If you tried some bitmap which less than 24bit. Most of those above methods should work.