Programs & Examples On #Atg

ATG's (Art Technology Group) Web Commerce platform. As of version 11 known as Oracle Commerce.

Why does C++ code for testing the Collatz conjecture run faster than hand-written assembly?

From comments:

But, this code never stops (because of integer overflow) !?! Yves Daoust

For many numbers it will not overflow.

If it will overflow - for one of those unlucky initial seeds, the overflown number will very likely converge toward 1 without another overflow.

Still this poses interesting question, is there some overflow-cyclic seed number?

Any simple final converging series starts with power of two value (obvious enough?).

2^64 will overflow to zero, which is undefined infinite loop according to algorithm (ends only with 1), but the most optimal solution in answer will finish due to shr rax producing ZF=1.

Can we produce 2^64? If the starting number is 0x5555555555555555, it's odd number, next number is then 3n+1, which is 0xFFFFFFFFFFFFFFFF + 1 = 0. Theoretically in undefined state of algorithm, but the optimized answer of johnfound will recover by exiting on ZF=1. The cmp rax,1 of Peter Cordes will end in infinite loop (QED variant 1, "cheapo" through undefined 0 number).

How about some more complex number, which will create cycle without 0? Frankly, I'm not sure, my Math theory is too hazy to get any serious idea, how to deal with it in serious way. But intuitively I would say the series will converge to 1 for every number : 0 < number, as the 3n+1 formula will slowly turn every non-2 prime factor of original number (or intermediate) into some power of 2, sooner or later. So we don't need to worry about infinite loop for original series, only overflow can hamper us.

So I just put few numbers into sheet and took a look on 8 bit truncated numbers.

There are three values overflowing to 0: 227, 170 and 85 (85 going directly to 0, other two progressing toward 85).

But there's no value creating cyclic overflow seed.

Funnily enough I did a check, which is the first number to suffer from 8 bit truncation, and already 27 is affected! It does reach value 9232 in proper non-truncated series (first truncated value is 322 in 12th step), and the maximum value reached for any of the 2-255 input numbers in non-truncated way is 13120 (for the 255 itself), maximum number of steps to converge to 1 is about 128 (+-2, not sure if "1" is to count, etc...).

Interestingly enough (for me) the number 9232 is maximum for many other source numbers, what's so special about it? :-O 9232 = 0x2410 ... hmmm.. no idea.

Unfortunately I can't get any deep grasp of this series, why does it converge and what are the implications of truncating them to k bits, but with cmp number,1 terminating condition it's certainly possible to put the algorithm into infinite loop with particular input value ending as 0 after truncation.

But the value 27 overflowing for 8 bit case is sort of alerting, this looks like if you count the number of steps to reach value 1, you will get wrong result for majority of numbers from the total k-bit set of integers. For the 8 bit integers the 146 numbers out of 256 have affected series by truncation (some of them may still hit the correct number of steps by accident maybe, I'm too lazy to check).

missing FROM-clause entry for table

SELECT 
   AcId, AcName, PldepPer, RepId, CustCatg, HardCode, BlockCust, CrPeriod, CrLimit, 
   BillLimit, Mode, PNotes, gtab82.memno 
FROM
   VCustomer AS v1
INNER JOIN   
   gtab82 ON gtab82.memacid = v1.AcId 
WHERE (AcGrCode = '204' OR CreDebt = 'True') 
AND Masked = 'false'
ORDER BY AcName

You typically only use an alias for a table name when you need to prefix a column with the table name due to duplicate column names in the joined tables and the table name is long or when the table is joined to itself. In your case you use an alias for VCustomer but only use it in the ON clause for uncertain reasons. You may want to review that aspect of your code.

How to calculate the number of occurrence of a given character in each row of a column of strings?

If you don't want to leave base R, here's a fairly succinct and expressive possibility:

x <- q.data$string
lengths(regmatches(x, gregexpr("a", x)))
# [1] 2 1 0

Remove part of a string

Maybe the most intuitive solution is probably to use the stringr function str_remove which is even easier than str_replace as it has only 1 argument instead of 2.

The only tricky part in your example is that you want to keep the underscore but its possible: You must match the regular expression until it finds the specified string pattern (?=pattern).

See example:

strings = c("TGAS_1121", "MGAS_1432", "ATGAS_1121")
strings %>% stringr::str_remove(".+?(?=_)")

[1] "_1121" "_1432" "_1121"

How can I force a long string without any blank to be wrapped?

I don't think you can do this with CSS. Instead, at regular 'word lengths' along the string, insert an HTML soft-hyphen:

ACTGATCG&shy;AGCTGAAG&shy;CGCAGTGC&shy;GATGCTTC&shy;GATGATGC&shy;TGACGATG

This will display a hyphen at the end of the line, where it wraps, which may or may not be what you want.

Note Safari seems to wrap the long string in a <textarea> anyway, unlike Firefox.

How to get current CPU and RAM usage in Python?

Use the psutil library. On Ubuntu 18.04, pip installed 5.5.0 (latest version) as of 1-30-2019. Older versions may behave somewhat differently. You can check your version of psutil by doing this in Python:

from __future__ import print_function  # for Python2
import psutil
print(psutil.__versi??on__)

To get some memory and CPU stats:

from __future__ import print_function
import psutil
print(psutil.cpu_percent())
print(psutil.virtual_memory())  # physical memory usage
print('memory % used:', psutil.virtual_memory()[2])

The virtual_memory (tuple) will have the percent memory used system-wide. This seemed to be overestimated by a few percent for me on Ubuntu 18.04.

You can also get the memory used by the current Python instance:

import os
import psutil
pid = os.getpid()
py = psutil.Process(pid)
memoryUse = py.memory_info()[0]/2.**30  # memory use in GB...I think
print('memory use:', memoryUse)

which gives the current memory use of your Python script.

There are some more in-depth examples on the pypi page for psutil.

Prevent a webpage from navigating away using JavaScript

Using onunload allows you to display messages, but will not interrupt the navigation (because it is too late). However, using onbeforeunload will interrupt navigation:

window.onbeforeunload = function() {
  return "";
}

Note: An empty string is returned because newer browsers provide a message such as "Any unsaved changes will be lost" that cannot be overridden.

In older browsers you could specify the message to display in the prompt:

window.onbeforeunload = function() {
  return "Are you sure you want to navigate away?";
}

Gradle failed to resolve library in Android Studio

For me follwing steps helped.

It seems to be bug of Android Studio 3.4/3.5 and it was "fixed" by disabling:

File ? Settings ? Experimental ? Gradle ? Only sync the active variant

PHP - find entry by object property from an array of objects

Using array_column to re-index will save time if you need to find multiple times:

$lookup = array_column($arr, NULL, 'id');   // re-index by 'id'

Then you can simply $lookup[$id] at will.

Looking for a 'cmake clean' command to clear up CMake output

I googled it for like half an hour and the only useful thing I came up with was invoking the find utility:

# Find and then delete all files under current directory (.) that:
#  1. contains "cmake" (case-&insensitive) in its path (wholename)
#  2. name is not CMakeLists.txt
find . -iwholename '*cmake*' -not -name CMakeLists.txt -delete

Also, be sure to invoke make clean (or whatever CMake generator you're using) before that.

:)

Is it possible to use global variables in Rust?

Look at the const and static section of the Rust book.

You can use something as follows:

const N: i32 = 5; 

or

static N: i32 = 5;

in global space.

But these are not mutable. For mutability, you could use something like:

static mut N: i32 = 5;

Then reference them like:

unsafe {
    N += 1;

    println!("N: {}", N);
}

How to download a Nuget package without nuget.exe or Visual Studio extension?

To obtain the current stable version of the NuGet package use:

https://www.nuget.org/api/v2/package/{packageID}

Java : Accessing a class within a package, which is the better way?

There is no performance difference between importing the package or using the fully qualified class name. The import directive is not converted to Java byte code, consequently there is no effect on runtime performance. The only difference is that it saves you time in case you are using the imported class multiple times. This is a good read here

The type initializer for 'Oracle.DataAccess.Client.OracleConnection' threw an exception

You need the oracle client driver installed for those classes to work.

There might be 3rd party connection frameworks out there that can handle Oracle, perhaps someone else might know of some specific ones.

What in layman's terms is a Recursive Function using PHP

This is a very simple example of factorial with Recursion:

Factorials are a very easy maths concept. They are written like 5! and this means 5 * 4 * 3 * 2 * 1. So 6! is 720 and 4! is 24.

function factorial($number) { 

    if ($number < 2) { 
        return 1; 
    } else { 
        return ($number * factorial($number-1)); 
    } 
}

hope this is usefull for you. :)

How do I print the type or class of a variable in Swift?

SWIFT 5

With the latest release of Swift 3 we can get pretty descriptions of type names through the String initializer. Like, for example print(String(describing: type(of: object))). Where object can be an instance variable like array, a dictionary, an Int, a NSDate, an instance of a custom class, etc.

Here is my complete answer: Get class name of object as string in Swift

That question is looking for a way to getting the class name of an object as string but, also i proposed another way to getting the class name of a variable that isn't subclass of NSObject. Here it is:

class Utility{
    class func classNameAsString(obj: Any) -> String {
        //prints more readable results for dictionaries, arrays, Int, etc
        return String(describing: type(of: obj))
    }
}

I made a static function which takes as parameter an object of type Any and returns its class name as String :) .

I tested this function with some variables like:

    let diccionary: [String: CGFloat] = [:]
    let array: [Int] = []
    let numInt = 9
    let numFloat: CGFloat = 3.0
    let numDouble: Double = 1.0
    let classOne = ClassOne()
    let classTwo: ClassTwo? = ClassTwo()
    let now = NSDate()
    let lbl = UILabel()

and the output was:

  • diccionary is of type Dictionary
  • array is of type Array
  • numInt is of type Int
  • numFloat is of type CGFloat
  • numDouble is of type Double
  • classOne is of type: ClassOne
  • classTwo is of type: ClassTwo
  • now is of type: Date
  • lbl is of type: UILabel

How to get current value of RxJS Subject or Observable?

Although it may sound overkill, this is just another "possible" solution to keep Observable type and reduce boilerplate...

You could always create an extension getter to get the current value of an Observable.

To do this you would need to extend the Observable<T> interface in a global.d.ts typings declaration file. Then implement the extension getter in a observable.extension.ts file and finally include both typings and extension file to your application.

You can refer to this StackOverflow Answer to know how to include the extensions into your Angular application.

// global.d.ts
declare module 'rxjs' {
  interface Observable<T> {
    /**
     * _Extension Method_ - Returns current value of an Observable.
     * Value is retrieved using _first()_ operator to avoid the need to unsubscribe.
     */
    value: Observable<T>;
  }
}

// observable.extension.ts
Object.defineProperty(Observable.prototype, 'value', {
  get <T>(this: Observable<T>): Observable<T> {
    return this.pipe(
      filter(value => value !== null && value !== undefined),
      first());
  },
});

// using the extension getter example
this.myObservable$.value
  .subscribe(value => {
    // whatever code you need...
  });

Display two fields side by side in a Bootstrap Form

did you check boostrap website? search for "forms"

<div class="form-row">
<div class="col">
  <input type="text" class="form-control" placeholder="First name">
</div>
<div class="col">
  <input type="text" class="form-control" placeholder="Last name">
</div>

How do I apply a perspective transform to a UIView?

You can get accurate Carousel effect using iCarousel SDK.

You can get an instant Cover Flow effect on iOS by using the marvelous and free iCarousel library. You can download it from https://github.com/nicklockwood/iCarousel and drop it into your Xcode project fairly easily by adding a bridging header (it's written in Objective-C).

If you haven't added Objective-C code to a Swift project before, follow these steps:

  • Download iCarousel and unzip it
  • Go into the folder you unzipped, open its iCarousel subfolder, then select iCarousel.h and iCarousel.m and drag them into your project navigation – that's the left pane in Xcode. Just below Info.plist is fine.
  • Check "Copy items if needed" then click Finish.
  • Xcode will prompt you with the message "Would you like to configure an Objective-C bridging header?" Click "Create Bridging Header" You should see a new file in your project, named YourProjectName-Bridging-Header.h.
  • Add this line to the file: #import "iCarousel.h"
  • Once you've added iCarousel to your project you can start using it.
  • Make sure you conform to both the iCarouselDelegate and iCarouselDataSource protocols.

Swift 3 Sample Code:

    override func viewDidLoad() {
      super.viewDidLoad()
      let carousel = iCarousel(frame: CGRect(x: 0, y: 0, width: 300, height: 200))
      carousel.dataSource = self
      carousel.type = .coverFlow
      view.addSubview(carousel) 
    }

   func numberOfItems(in carousel: iCarousel) -> Int {
        return 10
    }

    func carousel(_ carousel: iCarousel, viewForItemAt index: Int, reusing view: UIView?) -> UIView {
        let imageView: UIImageView

        if view != nil {
            imageView = view as! UIImageView
        } else {
            imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 128, height: 128))
        }

        imageView.image = UIImage(named: "example")

        return imageView
    }

Check mySQL version on Mac 10.8.5

Or just call mysql command with --version option.

mysql --version

Basic HTTP and Bearer Token Authentication

I had a similar problem - authenticate device and user at device. I used a Cookie header alongside an Authorization: Bearer... header. One header authenticated the device, the other authenticated the user. I used a Cookie header because these are commonly used for authentication.

Unescape HTML entities in Javascript?

Matthias Bynens has a library for this: https://github.com/mathiasbynens/he

Example:

console.log(
    he.decode("J&#246;rg &amp J&#xFC;rgen rocked to &amp; fro ")
);
// Logs "Jörg & Jürgen rocked to & fro"

I suggest favouring it over hacks involving setting an element's HTML content and then reading back its text content. Such approaches can work, but are deceptively dangerous and present XSS opportunities if used on untrusted user input.

If you really can't bear to load in a library, you can use the textarea hack described in this answer to a near-duplicate question, which, unlike various similar approaches that have been suggested, has no security holes that I know of:

function decodeEntities(encodedString) {
    var textArea = document.createElement('textarea');
    textArea.innerHTML = encodedString;
    return textArea.value;
}

console.log(decodeEntities('1 &amp; 2')); // '1 & 2'

But take note of the security issues, affecting similar approaches to this one, that I list in the linked answer! This approach is a hack, and future changes to the permissible content of a textarea (or bugs in particular browsers) could lead to code that relies upon it suddenly having an XSS hole one day.

Causes of getting a java.lang.VerifyError

VerifyError means that the class file contains bytecode that is syntactically correct but violates some semantic restriction e.g. a jump target that crosses method boundaries.

Basically, a VerifyError can only occur when there is a compiler bug, or when the class file gets corrupted in some other way (e.g. through faulty RAM or a failing HD).

Try compiling with a different JDK version and on a different machine.

Convert normal Java Array or ArrayList to Json Array in android

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

Something along those lines should work.

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

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

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

Regex for empty string or white space

If you're using jQuery, you have .trim().

if ($("#siren").val().trim() == "") {
  // it's empty
}

Can I pass variable to select statement as column name in SQL Server

You can't use variable names to bind columns or other system objects, you need dynamic sql

DECLARE @value varchar(10)  
SET @value = 'intStep'  
DECLARE @sqlText nvarchar(1000); 

SET @sqlText = N'SELECT ' + @value + ' FROM dbo.tblBatchDetail'
Exec (@sqlText)

Get git branch name in Jenkins Pipeline/Jenkinsfile

A colleague told me to use scm.branches[0].name and it worked. I wrapped it to a function in my Jenkinsfile:

def getGitBranchName() {
    return scm.branches[0].name
}

How do I dynamically assign properties to an object in TypeScript?

You can create new object based on the old object using the spread operator

interface MyObject {
    prop1: string;
}

const myObj: MyObject = {
    prop1: 'foo',
}

const newObj = {
    ...myObj,
    prop2: 'bar',
}

console.log(newObj.prop2); // 'bar'

TypeScript will infer all the fields of the original object and VSCode will do autocompletion, etc.

Good ways to manage a changelog using git?

A more to-the-point CHANGELOG.

git log --since=1/11/2011 --until=28/11/2011 --no-merges --format=%B

Can PHP cURL retrieve response headers AND body in a single request?

One solution to this was posted in the PHP documentation comments: http://www.php.net/manual/en/function.curl-exec.php#80442

Code example:

$ch = curl_init();
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_HEADER, 1);
// ...

$response = curl_exec($ch);

// Then, after your curl_exec call:
$header_size = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
$header = substr($response, 0, $header_size);
$body = substr($response, $header_size);

Warning: As noted in the comments below, this may not be reliable when used with proxy servers or when handling certain types of redirects. @Geoffrey's answer may handle these more reliably.

Eventviewer eventid for lock and unlock

For Windows 10 the event ID for lock=4800 and unlock=4801.

As it says in the answer provided by Mario and User 00000, you will need to enable logging of lock and unlock events by using their method described above by running gpedit.msc and navigating to the branch they indicated:

Computer Configuration -> Windows Settings -> Security Settings -> Advanced Audit Policy Configuration -> System Audit Policies - Local Group Policy Object -> Logon/Logoff -> Audit Other Login/Logoff

Enable for both success and failure events.

After enabling logging of those events you can filter for Event ID 4800 and 4801 directly.

This method works for Windows 10 as I just used it to filter my security logs after locking and unlocking my computer.

How can I get the intersection, union, and subset of arrays in Ruby?

I assume X and Y are arrays? If so, there's a very simple way to do this:

x = [1, 1, 2, 4]
y = [1, 2, 2, 2]

# intersection
x & y            # => [1, 2]

# union
x | y            # => [1, 2, 4]

# difference
x - y            # => [4]

Source

Instance member cannot be used on type

Your initial problem was:

class ReportView: NSView {
  var categoriesPerPage = [[Int]]()
  var numPages: Int = { return categoriesPerPage.count }
}

Instance member 'categoriesPerPage' cannot be used on type 'ReportView'

previous posts correctly point out, if you want a computed property, the = sign is errant.

Additional possibility for error:

If your intent was to "Setting a Default Property Value with a Closure or Function", you need only slightly change it as well. (Note: this example was obviously not intended to do that)

class ReportView: NSView {
  var categoriesPerPage = [[Int]]()
  var numPages: Int = { return categoriesPerPage.count }()
}

Instead of removing the =, we add () to denote a default initialization closure. (This can be useful when initializing UI code, to keep it all in one place.)

However, the exact same error occurs:

Instance member 'categoriesPerPage' cannot be used on type 'ReportView'

The problem is trying to initialize one property with the value of another. One solution is to make the initializer lazy. It will not be executed until the value is accessed.

class ReportView: NSView {
  var categoriesPerPage = [[Int]]()
  lazy var numPages: Int = { return categoriesPerPage.count }()
}

now the compiler is happy!

What is android:ems attribute in Edit Text?

Taken from: http://www.w3.org/Style/Examples/007/units:

The em is simply the font size. In an element with a 2in font, 1em thus means 2in. Expressing sizes, such as margins and paddings, in em means they are related to the font size, and if the user has a big font (e.g., on a big screen) or a small font (e.g., on a handheld device), the sizes will be in proportion. Declarations such as 'text-indent: 1.5em' and 'margin: 1em' are extremely common in CSS.

em is basically CSS property for font sizes.

WebSockets vs. Server-Sent events/EventSource

According to caniuse.com:

You can use a client-only polyfill to extend support of SSE to many other browsers. This is less likely with WebSockets. Some EventSource polyfills:

If you need to support all the browsers, consider using a library like web-socket-js, SignalR or socket.io which support multiple transports such as WebSockets, SSE, Forever Frame and AJAX long polling. These often require modifications to the server side as well.

Learn more about SSE from:

Learn more about WebSockets from:

Other differences:

  • WebSockets supports arbitrary binary data, SSE only uses UTF-8

Best way to save a trained model in PyTorch?

I've found this page on their github repo, I'll just paste the content here.


Recommended approach for saving a model

There are two main approaches for serializing and restoring a model.

The first (recommended) saves and loads only the model parameters:

torch.save(the_model.state_dict(), PATH)

Then later:

the_model = TheModelClass(*args, **kwargs)
the_model.load_state_dict(torch.load(PATH))

The second saves and loads the entire model:

torch.save(the_model, PATH)

Then later:

the_model = torch.load(PATH)

However in this case, the serialized data is bound to the specific classes and the exact directory structure used, so it can break in various ways when used in other projects, or after some serious refactors.

Android Paint: .measureText() vs .getTextBounds()

You can do what I did to inspect such problem:

Study Android source code, Paint.java source, see both measureText and getTextBounds methods. You'd learn that measureText calls native_measureText, and getTextBounds calls nativeGetStringBounds, which are native methods implemented in C++.

So you'd continue to study Paint.cpp, which implements both.

native_measureText -> SkPaintGlue::measureText_CII

nativeGetStringBounds -> SkPaintGlue::getStringBounds

Now your study checks where these methods differ. After some param checks, both call function SkPaint::measureText in Skia Lib (part of Android), but they both call different overloaded form.

Digging further into Skia, I see that both calls result into same computation in same function, only return result differently.

To answer your question: Both your calls do same computation. Possible difference of result lies in fact that getTextBounds returns bounds as integer, while measureText returns float value.

So what you get is rounding error during conversion of float to int, and this happens in Paint.cpp in SkPaintGlue::doTextBounds in call to function SkRect::roundOut.

The difference between computed width of those two calls may be maximally 1.

EDIT 4 Oct 2011

What may be better than visualization. I took the effort, for own exploring, and for deserving bounty :)

enter image description here

This is font size 60, in red is bounds rectangle, in purple is result of measureText.

It's seen that bounds left part starts some pixels from left, and value of measureText is incremented by this value on both left and right. This is something called Glyph's AdvanceX value. (I've discovered this in Skia sources in SkPaint.cpp)

So the outcome of the test is that measureText adds some advance value to the text on both sides, while getTextBounds computes minimal bounds where given text will fit.

Hope this result is useful to you.

Testing code:

  protected void onDraw(Canvas canvas){
     final String s = "Hello. I'm some text!";

     Paint p = new Paint();
     Rect bounds = new Rect();
     p.setTextSize(60);

     p.getTextBounds(s, 0, s.length(), bounds);
     float mt = p.measureText(s);
     int bw = bounds.width();

     Log.i("LCG", String.format(
          "measureText %f, getTextBounds %d (%s)",
          mt,
          bw, bounds.toShortString())
      );
     bounds.offset(0, -bounds.top);
     p.setStyle(Style.STROKE);
     canvas.drawColor(0xff000080);
     p.setColor(0xffff0000);
     canvas.drawRect(bounds, p);
     p.setColor(0xff00ff00);
     canvas.drawText(s, 0, bounds.bottom, p);
  }

Selecting data from two different servers in SQL Server

Server 2008:

When in SSMS connected to server1.DB1 and try:

SELECT  * FROM
[server2].[DB2].[dbo].[table1]

as others noted, if it doesn't work it's because the server isn't linked.

I get the error:

Could not find server DB2 in sys.servers. Verify that the correct server name was specified. If necessary, execute stored procedure sp_addlinkedserver to add the server to sys.servers.

To add the server:

reference: To add server using sp_addlinkedserver Link: [1]: To add server using sp_addlinkedserver

To see what is in your sys.servers just query it:

SELECT * FROM [sys].[servers]

Printing a char with printf

In C char gets promoted to int in expressions. That pretty much explains every question, if you think about it.

Source: The C Programming Language by Brian W.Kernighan and Dennis M.Ritchie

A must read if you want to learn C.

Also see this stack overflow page, where people much more experienced then me can explain it much better then I ever can.

Correct way of getting Client's IP Addresses from http.Request

Looking at http.Request you can find the following member variables:

// HTTP defines that header names are case-insensitive.
// The request parser implements this by canonicalizing the
// name, making the first character and any characters
// following a hyphen uppercase and the rest lowercase.
//
// For client requests certain headers are automatically
// added and may override values in Header.
//
// See the documentation for the Request.Write method.
Header Header

// RemoteAddr allows HTTP servers and other software to record
// the network address that sent the request, usually for
// logging. This field is not filled in by ReadRequest and
// has no defined format. The HTTP server in this package
// sets RemoteAddr to an "IP:port" address before invoking a
// handler.
// This field is ignored by the HTTP client.
RemoteAddr string

You can use RemoteAddr to get the remote client's IP address and port (the format is "IP:port"), which is the address of the original requestor or the last proxy (for example a load balancer which lives in front of your server).

This is all you have for sure.

Then you can investigate the headers, which are case-insensitive (per documentation above), meaning all of your examples will work and yield the same result:

req.Header.Get("X-Forwarded-For") // capitalisation
req.Header.Get("x-forwarded-for") // doesn't
req.Header.Get("X-FORWARDED-FOR") // matter

This is because internally http.Header.Get will normalise the key for you. (If you want to access header map directly, and not through Get, you would need to use http.CanonicalHeaderKey first.)

Finally, "X-Forwarded-For" is probably the field you want to take a look at in order to grab more information about client's IP. This greatly depends on the HTTP software used on the remote side though, as client can put anything in there if it wishes to. Also, note the expected format of this field is the comma+space separated list of IP addresses. You will need to parse it a little bit to get a single IP of your choice (probably the first one in the list), for example:

// Assuming format is as expected
ips := strings.Split("10.0.0.1, 10.0.0.2, 10.0.0.3", ", ")
for _, ip := range ips {
    fmt.Println(ip)
}

will produce:

10.0.0.1
10.0.0.2
10.0.0.3

Difference between a virtual function and a pure virtual function

A pure virtual function is usually not (but can be) implemented in a base class and must be implemented in a leaf subclass.

You denote that fact by appending the "= 0" to the declaration, like this:

class AbstractBase
{
    virtual void PureVirtualFunction() = 0;
}

Then you cannot declare and instantiate a subclass without it implementing the pure virtual function:

class Derived : public AbstractBase
{
    virtual void PureVirtualFunction() override { }
}

By adding the override keyword, the compiler will ensure that there is a base class virtual function with the same signature.

How to edit/save a file through Ubuntu Terminal

For editing use

vi galfit.feedme //if user has file editing permissions

or

sudo vi galfit.feedme //if user doesn't have file editing permissions

For inserting

Press i //Do required editing

For exiting

Press Esc

    :wq //for exiting and saving
    :q! //for exiting without saving

Apache Tomcat Not Showing in Eclipse Server Runtime Environments

In my case I needed to install "JST Server Adapters". I am running Eclipse 3.6 Helios RCP Edition.

Here are the steps I followed:

  1. Help -> Install New Software
  2. Choose "Helios - http://download.eclipse.org/releases/helios" site or kepler - http://download.ecliplse.org/releases/kepler
  3. Expand "Web, XML, and Java EE Development"
  4. Check JST Server Adapters (version 3.2.2)

After that I could define new Server Runtime Environments.

EDIT: With Eclipse 3.7 Indigo Classic, Eclipse Kepler and Luna, the steps are the same (with appropriate update site) but you need both JST Server Adapters and JST Server Adapters Extentions to get the Server Runtime Environment options.

ORA-06502: PL/SQL: numeric or value error: character string buffer too small

CHAR is a fixed-length data type that uses as much space as possible. So a:= a||'one '; will require more space than is available. Your problem can be reduced to the following example:

declare
  v_foo char(50);
begin
  v_foo := 'A';
  dbms_output.put_line('length of v_foo(A) = ' || length(v_foo));
  -- next line will raise:
  -- ORA-06502: PL/SQL: numeric or value error: character string buffer too small
  v_foo := v_foo || 'B';
  dbms_output.put_line('length of v_foo(AB) = ' || length(v_foo));  
end;
/

Never use char. For rationale check the following question (read also the links):

Unfortunately Launcher3 has stopped working error in android studio?

I had a similar problem with a physical device. The problem was related with the fact that the google app ( the search bar for google on top ) was disabled. After the first reboot launcher3 began failing. No matter how many cache/data cleaning I did, it kept failing. I reenabled it and launched it, so it appeared again on the screen and from that moment on, launcher3 was back to life.

I guess there mmust be some kind of dependency with this app.

How do you create nested dict in Python?

This thing is empty nested list from which ne will append data to empty dict

ls = [['a','a1','a2','a3'],['b','b1','b2','b3'],['c','c1','c2','c3'], 
['d','d1','d2','d3']]

this means to create four empty dict inside data_dict

data_dict = {f'dict{i}':{} for i in range(4)}
for i in range(4):
    upd_dict = {'val' : ls[i][0], 'val1' : ls[i][1],'val2' : ls[i][2],'val3' : ls[i][3]}

    data_dict[f'dict{i}'].update(upd_dict)

print(data_dict)

The output

{'dict0': {'val': 'a', 'val1': 'a1', 'val2': 'a2', 'val3': 'a3'}, 'dict1': {'val': 'b', 'val1': 'b1', 'val2': 'b2', 'val3': 'b3'},'dict2': {'val': 'c', 'val1': 'c1', 'val2': 'c2', 'val3': 'c3'}, 'dict3': {'val': 'd', 'val1': 'd1', 'val2': 'd2', 'val3': 'd3'}}

How to change app default theme to a different app theme?

If you are trying to reference an android style, you need to put "android:" in there

android:theme="@android:style/Theme.Black"

If that doesn't solve it, you may need to edit your question with the full manifest file, so we can see more details

Java: How to convert List to Map

You can leverage the streams API of Java 8.

public class ListToMap {

  public static void main(String[] args) {
    List<User> items = Arrays.asList(new User("One"), new User("Two"), new User("Three"));

    Map<String, User> map = createHashMap(items);
    for(String key : map.keySet()) {
      System.out.println(key +" : "+map.get(key));
    }
  }

  public static Map<String, User> createHashMap(List<User> items) {
    Map<String, User> map = items.stream().collect(Collectors.toMap(User::getId, Function.identity()));
    return map;
  }
}

For more details visit: http://codecramp.com/java-8-streams-api-convert-list-map/

Kotlin - How to correctly concatenate a String

Similar to @Rhusfer answer I wrote this. In case you have a group of EditTexts and want to concatenate their values, you can write:

listOf(edit_1, edit_2, edit_3, edit_4).joinToString(separator = "") { it.text.toString() }

If you want to concatenate Map, use this:

map.entries.joinToString(separator = ", ")

To concatenate Bundle, use

bundle.keySet().joinToString(", ") { key -> "$key=${bundle[key]}" }

It sorts keys in alphabetical order.

Example:

val map: MutableMap<String, Any> = mutableMapOf("price" to 20.5)
map += "arrange" to 0
map += "title" to "Night cream"
println(map.entries.joinToString(separator = ", "))

// price=20.5, arrange=0, title=Night cream

val bundle = bundleOf("price" to 20.5)
bundle.putAll(bundleOf("arrange" to 0))
bundle.putAll(bundleOf("title" to "Night cream"))
val bundleString =
    bundle.keySet().joinToString(", ") { key -> "$key=${bundle[key]}" }
println(bundleString)

// arrange=0, price=20.5, title=Night cream

PL/SQL print out ref cursor returned by a stored procedure

Note: This code is untested

Define a record for your refCursor return type, call it rec. For example:

TYPE MyRec IS RECORD (col1 VARCHAR2(10), col2 VARCHAR2(20), ...);  --define the record
rec MyRec;        -- instantiate the record

Once you have the refcursor returned from your procedure, you can add the following code where your comments are now:

LOOP
  FETCH refCursor INTO rec;
  EXIT WHEN refCursor%NOTFOUND;
  dbms_output.put_line(rec.col1||','||rec.col2||','||...);
END LOOP;

How to generate a simple popup using jQuery

I use a jQuery plugin called ColorBox, it is

  1. Very easy to use
  2. lightweight
  3. customizable
  4. the nicest popup dialog I have seen for jQuery yet

C# - Insert a variable number of spaces into a string? (Formatting an output file)

Use String.Format:

string title1 = "Sample Title One";
string element1 = "Element One";
string format = "{0,-20} {1,-10}";

string result = string.Format(format, title1, element1);
//or you can print to Console directly with
//Console.WriteLine(format, title1, element1);

In the format {0,-20} means the first argument has a fixed length 20, and the negative sign guarantees the string is printed from left to right.

Drawing an image from a data URL to a canvas

Perhaps this fiddle would help ThumbGen - jsFiddle It uses File API and Canvas to dynamically generate thumbnails of images.

(function (doc) {
    var oError = null;
    var oFileIn = doc.getElementById('fileIn');
    var oFileReader = new FileReader();
    var oImage = new Image();
    oFileIn.addEventListener('change', function () {
        var oFile = this.files[0];
        var oLogInfo = doc.getElementById('logInfo');
        var rFltr = /^(?:image\/bmp|image\/cis\-cod|image\/gif|image\/ief|image\/jpeg|image\/jpeg|image\/jpeg|image\/pipeg|image\/png|image\/svg\+xml|image\/tiff|image\/x\-cmu\-raster|image\/x\-cmx|image\/x\-icon|image\/x\-portable\-anymap|image\/x\-portable\-bitmap|image\/x\-portable\-graymap|image\/x\-portable\-pixmap|image\/x\-rgb|image\/x\-xbitmap|image\/x\-xpixmap|image\/x\-xwindowdump)$/i
        try {
            if (rFltr.test(oFile.type)) {
                oFileReader.readAsDataURL(oFile);
                oLogInfo.setAttribute('class', 'message info');
                throw 'Preview for ' + oFile.name;
            } else {
                oLogInfo.setAttribute('class', 'message error');
                throw oFile.name + ' is not a valid image';
            }
        } catch (err) {
            if (oError) {
                oLogInfo.removeChild(oError);
                oError = null;
                $('#logInfo').fadeOut();
                $('#imgThumb').fadeOut();
            }
            oError = doc.createTextNode(err);
            oLogInfo.appendChild(oError);
            $('#logInfo').fadeIn();
        }
    }, false);
    oFileReader.addEventListener('load', function (e) {
        oImage.src = e.target.result;
    }, false);
    oImage.addEventListener('load', function () {
        if (oCanvas) {
            oCanvas = null;
            oContext = null;
            $('#imgThumb').fadeOut();
        }
        var oCanvas = doc.getElementById('imgThumb');
        var oContext = oCanvas.getContext('2d');
        var nWidth = (this.width > 500) ? this.width / 4 : this.width;
        var nHeight = (this.height > 500) ? this.height / 4 : this.height;
        oCanvas.setAttribute('width', nWidth);
        oCanvas.setAttribute('height', nHeight);
        oContext.drawImage(this, 0, 0, nWidth, nHeight);
        $('#imgThumb').fadeIn();
    }, false);
})(document);

How can I get a channel ID from YouTube?

An easy answer is, your YouTube Channel ID is UC + {YOUR_ACCOUNT_ID}. To be sure of your YouTube Channel ID or your YouTube account ID, access the advanced settings at your settings page

And if you want to know the YouTube Channel ID for any channel, you could use the solution @mjlescano gave.

https://www.googleapis.com/youtube/v3/channels?key={YOUR_API_KEY}&forUsername={USER_NAME}&part=id

If this could be of any help, some user marked it was solved in another topic right here.

Allow Access-Control-Allow-Origin header using HTML5 fetch API

This worked for me :

npm install -g local-cors-proxy

API endpoint that we want to request that has CORS issues:

https://www.yourdomain.com/test/list

Start Proxy:

lcp --proxyUrl https://www.yourdomain.com

 Proxy Active 

 Proxy Url: http://www.yourdomain.com:28080
 Proxy Partial: proxy
 PORT: 8010

Then in your client code, new API endpoint:

http://localhost:8010/proxy/test/list

End result will be a request to https://www.yourdomain.ie/test/list without the CORS issues!

Play a Sound with Python

Definitely use Pyglet for this. It's kind of a large package, but it is pure python with no extension modules. That will definitely be the easiest for deployment. It's also got great format and codec support.

import pyglet

music = pyglet.resource.media('music.mp3')
music.play()

pyglet.app.run()

Autonumber value of last inserted row - MS Access / VBA

If DAO use

RS.Move 0, RS.LastModified
lngID = RS!AutoNumberFieldName

If ADO use

cn.Execute "INSERT INTO TheTable.....", , adCmdText + adExecuteNoRecords
Set rs = cn.Execute("SELECT @@Identity", , adCmdText)
Debug.Print rs.Fields(0).Value

cn being a valid ADO connection, @@Identity will return the last Identity (Autonumber) inserted on this connection.

Note that @@Identity might be troublesome because the last generated value may not be the one you are interested in. For the Access database engine, consider a VIEW that joins two tables, both of which have the IDENTITY property, and you INSERT INTO the VIEW. For SQL Server, consider if there are triggers that in turn insert records into another table that also has the IDENTITY property.

BTW DMax would not work as if someone else inserts a record just after you've inserted one but before your Dmax function finishes excecuting, then you would get their record.

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

you can check installed c# compilers and the printed version of the .net:

@echo off

for /r "%SystemRoot%\Microsoft.NET\Framework\" %%# in ("*csc.exe") do (
    set "l="
    for /f "skip=1 tokens=2 delims=k" %%$ in ('"%%# #"') do (
        if not defined l (
            echo Installed: %%$
            set l=%%$
        )
    )
)

echo latest installed .NET %l%

the csc.exe does not have a -version switch but it prints the .net version in its logo. You can also try with msbuild.exe but .net framework 1.* does not have msbuild.

How to initialize an array in Java?

Try data = new int[] {10,20,30,40,50,60,71,80,90,91 };

python pip on Windows - command 'cl.exe' failed

  1. Install Microsoft visual c++ 14.0 build tool.(Windows 7)
  2. create a virtual environment using conda.
  3. Activate the environment and use conda to install the necessary package.

For example: conda install -c conda-forge spacy

Can I use an HTML input type "date" to collect only a year?

You can do the following:

  1. Generate an Array of the years I'll be accepting,
  2. Use a select box.
  3. Use each item from your Array as an 'option' tag.

Example using PHP (you can do this in any language of your choice):

Server:

<?php $years = range(1900, strftime("%Y", time())); ?>

HTML

<select>
  <option>Select Year</option>
  <?php foreach($years as $year) : ?>
    <option value="<?php echo $year; ?>"><?php echo $year; ?></option>
  <?php endforeach; ?>
</select>

As an added benefit, this works has a browser compatibility of a 100% ;-)

How to dynamically change header based on AngularJS partial view?

Alternatively, if you are using ui-router:

index.html

<!DOCTYPE html>
<html ng-app="myApp">
<head>
    <title ng-bind="$state.current.data.title || 'App'">App</title>

Routing

$stateProvider
  .state('home', {
      url: '/',
      templateUrl: 'views/home.html',
      data: {
        title: 'Welcome Home.'
      }
  }

Import SQL file by command line in Windows 7

mysql : < (for import) > (for export)

in windows, you want to take backup or import the sql file, then goto cmd prompt type the address were the mysql is installed eg:C:\Program Files (x86)\MySQL\MySQL Server 5.6\bin> after this

C:\Program Files (x86)\MySQL\MySQL Server 5.6\bin> mysql -u UserName -p Password DatabaseName < FileName.sql (import)

C:\Program Files (x86)\MySQL\MySQL Server 5.6\bin> mysql -u UserName -p Password DatabaseName > FileName.sql (export)

Atom menu is missing. How do I re-enable

CONTROL + SHIFT + P and execute command "Tree View: Show"

What's the most useful and complete Java cheat sheet?

  1. I have personally found the dzone cheatsheet on core java to be really handy in the beginning. However the needs change as we grow and get used to things.

  2. There are a few listed (at the end of the post) in on this java learning resources article too

  3. For the most practical use, in recent past I have found Java API doc to be the best place to cheat code and learn new api. This helps specially when you want to focus on latest version of java.

  4. mkyong - is one my fav places to cheat a lot of code for quick start - http://www.mkyong.com/

  5. And last but not the least, Stackoverflow is king of all small handy code snippets. Just google a stuff you are trying and there is a chance that a page will be top of search results, most of my google search results end at stackoverflow. Many of the common questions are available here - https://stackoverflow.com/questions/tagged/java?sort=frequent

What's the best way to build a string of delimited items in Java?

And a minimal one (if you don't want to include Apache Commons or Gauva into project dependencies just for the sake of joining strings)

/**
 *
 * @param delim : String that should be kept in between the parts
 * @param parts : parts that needs to be joined
 * @return  a String that's formed by joining the parts
 */
private static final String join(String delim, String... parts) {
    StringBuilder builder = new StringBuilder();
    for (int i = 0; i < parts.length - 1; i++) {
        builder.append(parts[i]).append(delim);
    }
    if(parts.length > 0){
        builder.append(parts[parts.length - 1]);
    }
    return builder.toString();
}

Use PPK file in Mac Terminal to connect to remote connection over SSH

There is a way to do this without installing putty on your Mac. You can easily convert your existing PPK file to a PEM file using PuTTYgen on Windows.

Launch PuTTYgen and then load the existing private key file using the Load button. From the "Conversions" menu select "Export OpenSSH key" and save the private key file with the .pem file extension.

Copy the PEM file to your Mac and set it to be read-only by your user:

chmod 400 <private-key-filename>.pem

Then you should be able to use ssh to connect to your remote server

ssh -i <private-key-filename>.pem username@hostname

How to create a new component in Angular 4 using CLI

go to your project directory in CMD, and run the following commands. You can use the visual studio code terminal also.

ng generate component "component_name"

OR

ng g c "component_name"

a new folder with "component_name" will be created

component_name/component_name.component.html component_name/component_name.component.spec.ts component_name/component_name.component.ts component_name/component_name.component.css

new component will be Automatically added module.

you can avoid creating spec file by following command

ng g c "component_name" --nospec

How to debug a referenced dll (having pdb)

Step 1: Go to Tools-->Option-->Debugging

Step 2: Uncheck Enable Just My Code

Step 3: Uncheck Require source file exactly match with original Version

Step 4: Uncheck Step over Properties and Operators

Step 5: Go to Project properties-->Debug

Step 6: Check Enable native code debugging

How to move/rename a file using an Ansible task on a remote system

- name: Move the src file to dest
  command: mv /path/to/src /path/to/dest
  args:
    removes: /path/to/src
    creates: /path/to/dest

This runs the mv command only when /path/to/src exists and /path/to/dest does not, so it runs once per host, moves the file, then doesn't run again.

I use this method when I need to move a file or directory on several hundred hosts, many of which may be powered off at any given time. It's idempotent and safe to leave in a playbook.

PHP refresh window? equivalent to F5 page reload?

with php you can use two redirections. It works same as refresh in some issues.

you can use a page redirect.php and post your last url to it by GET method (for example). then in redirect.php you can change header to location you`ve sent to it by GET method.

like this: your page:

<?php
header("location:redirec.php?ref=".$your_url);
?>

redirect.php:

<?php
$ref_url=$_GET["ref"];
header("location:redirec.php?ref=".$ref_url);
?>

that worked for me good.

Set the absolute position of a view

Check screenshot

Place any view on your desire X & Y point

layout file

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.test.MainActivity" >

    <AbsoluteLayout
        android:id="@+id/absolute"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

        <RelativeLayout
            android:id="@+id/rlParent"
            android:layout_width="match_parent"
            android:layout_height="match_parent" >

            <ImageView
                android:id="@+id/img"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="@drawable/btn_blue_matte" />
        </RelativeLayout>
    </AbsoluteLayout>

</RelativeLayout>

Java Class

public class MainActivity extends Activity {

    private RelativeLayout rlParent;
    private int width = 100, height = 150, x = 20, y= 50; 

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

        AbsoluteLayout.LayoutParams param = new AbsoluteLayout.LayoutParams(width, height, x, y);
        rlParent = (RelativeLayout)findViewById(R.id.rlParent);
        rlParent.setLayoutParams(param);
    }
}

Done

How do I set vertical space between list items?

To apply to an entire list, use

ul.space_list li { margin-bottom: 1em; }

Then, in the html:

<ul class=space_list>
<li>A</li>
<li>B</li>
</ul>

How do you do Impersonation in .NET?

View more detail from my previous answer I have created an nuget package Nuget

Code on Github

sample : you can use :

           string login = "";
           string domain = "";
           string password = "";

           using (UserImpersonation user = new UserImpersonation(login, domain, password))
           {
               if (user.ImpersonateValidUser())
               {
                   File.WriteAllText("test.txt", "your text");
                   Console.WriteLine("File writed");
               }
               else
               {
                   Console.WriteLine("User not connected");
               }
           }

Vieuw the full code :

using System;
using System.Runtime.InteropServices;
using System.Security.Principal;


/// <summary>
/// Object to change the user authticated
/// </summary>
public class UserImpersonation : IDisposable
{
    /// <summary>
    /// Logon method (check athetification) from advapi32.dll
    /// </summary>
    /// <param name="lpszUserName"></param>
    /// <param name="lpszDomain"></param>
    /// <param name="lpszPassword"></param>
    /// <param name="dwLogonType"></param>
    /// <param name="dwLogonProvider"></param>
    /// <param name="phToken"></param>
    /// <returns></returns>
    [DllImport("advapi32.dll")]
    private static extern bool LogonUser(String lpszUserName,
        String lpszDomain,
        String lpszPassword,
        int dwLogonType,
        int dwLogonProvider,
        ref IntPtr phToken);

    /// <summary>
    /// Close
    /// </summary>
    /// <param name="handle"></param>
    /// <returns></returns>
    [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
    public static extern bool CloseHandle(IntPtr handle);

    private WindowsImpersonationContext _windowsImpersonationContext;
    private IntPtr _tokenHandle;
    private string _userName;
    private string _domain;
    private string _passWord;

    const int LOGON32_PROVIDER_DEFAULT = 0;
    const int LOGON32_LOGON_INTERACTIVE = 2;

    /// <summary>
    /// Initialize a UserImpersonation
    /// </summary>
    /// <param name="userName"></param>
    /// <param name="domain"></param>
    /// <param name="passWord"></param>
    public UserImpersonation(string userName, string domain, string passWord)
    {
        _userName = userName;
        _domain = domain;
        _passWord = passWord;
    }

    /// <summary>
    /// Valiate the user inforamtion
    /// </summary>
    /// <returns></returns>
    public bool ImpersonateValidUser()
    {
        bool returnValue = LogonUser(_userName, _domain, _passWord,
                LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT,
                ref _tokenHandle);

        if (false == returnValue)
        {
            return false;
        }

        WindowsIdentity newId = new WindowsIdentity(_tokenHandle);
        _windowsImpersonationContext = newId.Impersonate();
        return true;
    }

    #region IDisposable Members

    /// <summary>
    /// Dispose the UserImpersonation connection
    /// </summary>
    public void Dispose()
    {
        if (_windowsImpersonationContext != null)
            _windowsImpersonationContext.Undo();
        if (_tokenHandle != IntPtr.Zero)
            CloseHandle(_tokenHandle);
    }

    #endregion
}

Convert bytes to a string

In Python 3, the default encoding is "utf-8", so you can directly use:

b'hello'.decode()

which is equivalent to

b'hello'.decode(encoding="utf-8")

On the other hand, in Python 2, encoding defaults to the default string encoding. Thus, you should use:

b'hello'.decode(encoding)

where encoding is the encoding you want.

Note: support for keyword arguments was added in Python 2.7.

Using Mockito, how do I verify a method was a called with a certain argument?

This is the better solution:

verify(mock_contractsDao, times(1)).save(Mockito.eq("Parameter I'm expecting"));

Left Outer Join using + sign in Oracle 11g

Those two queries are performing OUTER JOIN. See below

Oracle recommends that you use the FROM clause OUTER JOIN syntax rather than the Oracle join operator. Outer join queries that use the Oracle join operator (+) are subject to the following rules and restrictions, which do not apply to the FROM clause OUTER JOIN syntax:

  • You cannot specify the (+) operator in a query block that also contains FROM clause join syntax.

  • The (+) operator can appear only in the WHERE clause or, in the context of left- correlation (when specifying the TABLE clause) in the FROM clause, and can be applied only to a column of a table or view.

  • If A and B are joined by multiple join conditions, then you must use the (+) operator in all of these conditions. If you do not, then Oracle Database will return only the rows resulting from a simple join, but without a warning or error to advise you that you do not have the results of an outer join.

  • The (+) operator does not produce an outer join if you specify one table in the outer query and the other table in an inner query.

  • You cannot use the (+) operator to outer-join a table to itself, although self joins are valid. For example, the following statement is not valid:

    -- The following statement is not valid:
    SELECT employee_id, manager_id
       FROM employees
       WHERE employees.manager_id(+) = employees.employee_id;
    

    However, the following self join is valid:

    SELECT e1.employee_id, e1.manager_id, e2.employee_id
       FROM employees e1, employees e2
       WHERE e1.manager_id(+) = e2.employee_id
       ORDER BY e1.employee_id, e1.manager_id, e2.employee_id;
    
  • The (+) operator can be applied only to a column, not to an arbitrary expression. However, an arbitrary expression can contain one or more columns marked with the (+) operator.

  • A WHERE condition containing the (+) operator cannot be combined with another condition using the OR logical operator.

  • A WHERE condition cannot use the IN comparison condition to compare a column marked with the (+) operator with an expression.

If the WHERE clause contains a condition that compares a column from table B with a constant, then the (+) operator must be applied to the column so that Oracle returns the rows from table A for which it has generated nulls for this column. Otherwise Oracle returns only the results of a simple join.

In a query that performs outer joins of more than two pairs of tables, a single table can be the null-generated table for only one other table. For this reason, you cannot apply the (+) operator to columns of B in the join condition for A and B and the join condition for B and C. Refer to SELECT for the syntax for an outer join.

Taken from http://download.oracle.com/docs/cd/B28359_01/server.111/b28286/queries006.htm

How to detect control+click in Javascript from an onclick div attribute?

I'd recommend using JQuery's keyup and keydown methods on the document, as it normalizes the event codes, to make one solution crossbrowser.

For the right click, you can use oncontextmenu, however beware it can be buggy in IE8. See a chart of compatibility here:

http://www.quirksmode.org/dom/events/contextmenu.html

<p onclick="selectMe(1)" oncontextmenu="selectMe(2)">Click me</p>

$(document).keydown(function(event){
    if(event.which=="17")
        cntrlIsPressed = true;
});

$(document).keyup(function(){
    cntrlIsPressed = false;
});

var cntrlIsPressed = false;


function selectMe(mouseButton)
{
    if(cntrlIsPressed)
    {
        switch(mouseButton)
        {
            case 1:
                alert("Cntrl +  left click");
                break;
            case 2:
                alert("Cntrl + right click");
                break;
            default:
                break;
        }
    }


}

Print a file's last modified date in Bash

On OS X, I like my date to be in the format of YYYY-MM-DD HH:MM in the output for the file.

So to specify a file I would use:

stat -f "%Sm" -t "%Y-%m-%d %H:%M" [filename]

If I want to run it on a range of files, I can do something like this:

#!/usr/bin/env bash
for i in /var/log/*.out; do
  stat -f "%Sm" -t "%Y-%m-%d %H:%M" "$i"
done

This example will print out the last time I ran the sudo periodic daily weekly monthly command as it references the log files.


To add the filenames under each date, I would run the following instead:

#!/usr/bin/env bash
for i in /var/log/*.out; do
  stat -f "%Sm" -t "%Y-%m-%d %H:%M" "$i"
  echo "$i"
done

The output would was the following:

2016-40-01 16:40
/var/log/daily.out
2016-40-01 16:40
/var/log/monthly.out
2016-40-01 16:40
/var/log/weekly.out

Unfortunately I'm not sure how to prevent the line break and keep the file name appended to the end of the date without adding more lines to the script.


PS - I use #!/usr/bin/env bash as I'm a Python user by day, and have different versions of bash installed on my system instead of #!/bin/bash

How to make exe files from a node.js app?

I was using below technology:

  1. @vercel/ncc (this make sure we bundle all necessary dependency into single file)
  2. pkg (this to make exe file)

Let do below:

  1. npm i -g @vercel/ncc

  2. ncc build app.ts -o dist (my entry file is app.ts, output is in dist folder, make sure you run in folder where package.json and app.ts reside, after run above you may see the index.js file in the folder dist)

  3. npm install -g pkg (installing pkg)

  4. pkg index.js (make sure you are in the dist folder above)

Using Server.MapPath() inside a static field in ASP.NET MVC

I think you can try this for calling in from a class

 System.Web.HttpContext.Current.Server.MapPath("~/SignatureImages/");

*----------------Sorry I oversight, for static function already answered the question by adrift*

System.Web.Hosting.HostingEnvironment.MapPath("~/SignatureImages/");

Update

I got exception while using System.Web.Hosting.HostingEnvironment.MapPath("~/SignatureImages/");

Ex details : System.ArgumentException: The relative virtual path 'SignatureImages' is not allowed here. at System.Web.VirtualPath.FailIfRelativePath()

Solution (tested in static webmethod)

System.Web.HttpContext.Current.Server.MapPath("~/SignatureImages/"); Worked

How can I display the current branch and folder path in terminal?

From Mac OS Catalina .bash_profile is replaced with .zprofile

Step 1: Create a .zprofile

touch .zprofile

Step 2:

nano .zprofile

type below line in this

source ~/.bash_profile

and save(ctrl+o return ctrl+x)

Step 3: Restart your terminal

To Add Git Branch Name Now you can add below lines in .bash_profile

    parse_git_branch() {
    git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/ (\1)/'
}

export PS1="\u@\h \[\033[32m\]\w - \$(parse_git_branch)\[\033[00m\] $ "

Restart your terminal this will work.

Note: Even you can rename .bash_profile to .zprofile that also works.

Executing <script> elements inserted with .innerHTML

It's easier to use jquery $(parent).html(code) instead of parent.innerHTML = code:

var oldDocumentWrite = document.write;
var oldDocumentWriteln = document.writeln;
try {
    document.write = function(code) {
        $(parent).append(code);
    }
    document.writeln = function(code) {
        document.write(code + "<br/>");
    }
    $(parent).html(html); 
} finally {
    $(window).load(function() {
        document.write = oldDocumentWrite
        document.writeln = oldDocumentWriteln
    })
}

This also works with scripts that use document.write and scripts loaded via src attribute. Unfortunately even this doesn't work with Google AdSense scripts.

How to cin to a vector

#include<iostream>
#include<vector>
#include<string>
using namespace std;
int main()
{
    vector<string>V;
    int num;
    cin>>num;
    string input;
    while (cin>>input && num != 0) //enter any non-integer to end the loop!
{
    //cin>>input;
   V.push_back(input);
   num--;
   if(num==0)
   {
   vector<string>::iterator it;
    for(it=V.begin();it!=V.end();it++)
        cout<<*it<<endl;
   };

}
return 0;

};

Python urllib2, basic HTTP authentication, and tr.im

Same solutions as Python urllib2 Basic Auth Problem apply.

see https://stackoverflow.com/a/24048852/1733117; you can subclass urllib2.HTTPBasicAuthHandler to add the Authorization header to each request that matches the known url.

class PreemptiveBasicAuthHandler(urllib2.HTTPBasicAuthHandler):
    '''Preemptive basic auth.

    Instead of waiting for a 403 to then retry with the credentials,
    send the credentials if the url is handled by the password manager.
    Note: please use realm=None when calling add_password.'''
    def http_request(self, req):
        url = req.get_full_url()
        realm = None
        # this is very similar to the code from retry_http_basic_auth()
        # but returns a request object.
        user, pw = self.passwd.find_user_password(realm, url)
        if pw:
            raw = "%s:%s" % (user, pw)
            auth = 'Basic %s' % base64.b64encode(raw).strip()
            req.add_unredirected_header(self.auth_header, auth)
        return req

    https_request = http_request

How to print float to n decimal places including trailing 0s?

Floating point numbers lack precision to accurately represent "1.6" out to that many decimal places. The rounding errors are real. Your number is not actually 1.6.

Check out: http://docs.python.org/library/decimal.html

How to print_r $_POST array?

$_POST is already an array. Try this:

foreach ($_POST as $key => $value) {
    echo "<p>".$key."</p>";
    echo "<p>".$value."</p>";
    echo "<hr />";
} 

How to set the context path of a web application in Tomcat 7.0

I faced this problem for one month,Putting context tag inside server.xml is not safe it affect context elements deploying for all other host ,for big apps it take connection errors also not good isolation for example you may access other sites by folder name domain2.com/domain1Folder !! also database session connections loaded twice ! the other way is put ROOT.xml file that has context tag with full path such :

 <Context path="" docBase="/var/lib/tomcat7/webapps/ROOT" />

in conf/catalina/webappsfoldername and deploy war file as ROOT.war inside webappsfoldername and also specify host such

 <Host name="domianname"  appBase="webapps2" unpackWARs="true"  autoDeploy="true"  xmlValidation="false" xmlNamespaceAware="false" >

        <Logger className="org.apache.catalina.logger.FileLogger"
               directory="logs"  prefix="localhost_log." suffix=".txt"
          timestamp="true"/>
</Host>

In this approach also for same type apps user sessions has not good isolation ! you may inside app1 if app1 same as app2 you may after login by server side session automatically can login to app2 ?! So you have to keep users session in client side cache and not with jsessionid ! we may change engine name from localhost to solve it. but let say playing with tomcat need more time than play with other cats!

When to encode space to plus (+) or %20?

So, the answers here are all a bit incomplete. The use of a '%20' to encode a space in URLs is explicitly defined in RFC3986, which defines how a URI is built. There is no mention in this specification of using a '+' for encoding spaces - if you go solely by this specification, a space must be encoded as '%20'.

The mention of using '+' for encoding spaces comes from the various incarnations of the HTML specification - specifically in the section describing content type 'application/x-www-form-urlencoded'. This is used for posting form data.

Now, the HTML 2.0 Specification (RFC1866) explicitly said, in section 8.2.2, that the Query part of a GET request's URL string should be encoded as 'application/x-www-form-urlencoded'. This, in theory, suggests that it's legal to use a '+' in the URL in the query string (after the '?').

But... does it really? Remember, HTML is itself a content specification, and URLs with query strings can be used with content other than HTML. Further, while the later versions of the HTML spec continue to define '+' as legal in 'application/x-www-form-urlencoded' content, they completely omit the part saying that GET request query strings are defined as that type. There is, in fact, no mention whatsoever about the query string encoding in anything after the HTML 2.0 spec.

Which leaves us with the question - is it valid? Certainly there's a LOT of legacy code which supports '+' in query strings, and a lot of code which generates it as well. So odds are good you won't break if you use '+'. (And, in fact, I did all the research on this recently because I discovered a major site which failed to accept '%20' in a GET query as a space. They actually failed to decode ANY percent encoded character. So the service you're using may be relevant as well.)

But from a pure reading of the specifications, without the language from the HTML 2.0 specification carried over into later versions, URLs are covered entirely by RFC3986, which means spaces ought to be converted to '%20'. And definitely that should be the case if you are requesting anything other than an HTML document.

Fatal error: Call to undefined function mcrypt_encrypt()

Under Ubuntu I had the problem and solved it with

$ sudo apt-get install php5-mcrypt
$ sudo service apache2 reload

Simple way to create matrix of random numbers

When you say "a matrix of random numbers", you can use numpy as Pavel https://stackoverflow.com/a/15451997/6169225 mentioned above, in this case I'm assuming to you it is irrelevant what distribution these (pseudo) random numbers adhere to.

However, if you require a particular distribution (I imagine you are interested in the uniform distribution), numpy.random has very useful methods for you. For example, let's say you want a 3x2 matrix with a pseudo random uniform distribution bounded by [low,high]. You can do this like so:

numpy.random.uniform(low,high,(3,2))

Note, you can replace uniform by any number of distributions supported by this library.

Further reading: https://docs.scipy.org/doc/numpy/reference/routines.random.html

Background color for Tk in Python

Its been updated so

root.configure(background="red")

is now:

root.configure(bg="red")

How to get index of object by its property in JavaScript?

What about this ? :

Data.indexOf(_.find(Data, function(element) {
  return element.name === 'John';
}));

Assuming you are using lodash or underscorejs.

Rank function in MySQL

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

SELECT customerID, myDate

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

  -- Erandac's method in combination of Daniel's and Salman's
  -- count all items in sequence, maximum reaches row count.
  , IF(customerID=@_lastRank, @_curRank:=@_curRank, @_curRank:=@_sequence+1) AS sequenceRank
  , @_sequence:=@_sequence+1 as sequenceOverAll

  -- Dense partition ranking, works also with MySQL 5.7
  -- remember to set offset values in from clause
  , IF(customerID=@_lastRank, @_nxtRank:=@_nxtRank, @_nxtRank:=@_nxtRank+1 ) AS partitionRank
  , IF(customerID=@_lastRank, @_overPart:=@_overPart+1, @_overPart:=1 ) AS partitionSequence

  , @_lastRank:=customerID
FROM myCustomers, 
  (SELECT @_curRank:=0, @_sequence:=0, @_lastRank:=0, @_nxtRank:=0, @_overPart:=0 ) r
ORDER BY customerID, myDate

The partition ranking in the 3rd variant in this code snippet will return continous ranking numbers. this will lead to a data structur similar to the rank() over partition by result. As an example, see below. In particular, the partitionSequence will always start with 1 for each new partitionRank, using this method:

customerID    myDate   sequenceRank (Erandac)
                          |    sequenceOverAll
                          |     |   partitionRank
                          |     |     | partitionSequence
                          |     |     |    | lastRank
... lines ommitted for clarity
40    09.11.2016 11:19    1     44    1   44    40
40    09.12.2016 12:08    1     45    1   45    40
40    09.12.2016 12:08    1     46    1   46    40
40    09.12.2016 12:11    1     47    1   47    40
40    09.12.2016 12:12    1     48    1   48    40
40    13.10.2017 16:31    1     49    1   49    40
40    15.10.2017 11:00    1     50    1   50    40
76    01.07.2015 00:24    51    51    2    1    76
77    04.08.2014 13:35    52    52    3    1    77
79    15.04.2015 20:25    53    53    4    1    79
79    24.04.2018 11:44    53    54    4    2    79
79    08.10.2018 17:37    53    55    4    3    79
117   09.07.2014 18:21    56    56    5    1   117
119   26.06.2014 13:55    57    57    6    1   119
119   02.03.2015 10:23    57    58    6    2   119
119   12.10.2015 10:16    57    59    6    3   119
119   08.04.2016 09:32    57    60    6    4   119
119   05.10.2016 12:41    57    61    6    5   119
119   05.10.2016 12:42    57    62    6    6   119
...

Best way to represent a Grid or Table in AngularJS with Bootstrap 3?

You can use bootstrap 3 classes and build a table using the ng-repeat directive

Example:

_x000D_
_x000D_
angular.module('App', []);_x000D_
_x000D_
function ctrl($scope) {_x000D_
    $scope.items = [_x000D_
        ['A', 'B', 'C'],_x000D_
        ['item1', 'item2', 'item3'],_x000D_
        ['item4', 'item5', 'item6']_x000D_
    ];_x000D_
}
_x000D_
<link href="http://netdna.bootstrapcdn.com/bootstrap/3.0.3/css/bootstrap.min.css" rel="stylesheet" />_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>_x000D_
_x000D_
<div ng-app="App">_x000D_
  <div ng-controller="ctrl">_x000D_
    _x000D_
    _x000D_
    <table class="table table-bordered">_x000D_
      <thead>_x000D_
        <tr>_x000D_
          <th ng-repeat="itemA in items[0]">{{itemA}}</th>_x000D_
        </tr>_x000D_
      </thead>_x000D_
      <tbody>_x000D_
        <tr>_x000D_
          <td ng-repeat="itemB in items[1]">{{itemB}}</td>_x000D_
        </tr>_x000D_
        <tr>_x000D_
          <td ng-repeat="itemC in items[2]">{{itemC}}</td>_x000D_
        </tr>_x000D_
      </tbody>_x000D_
    </table>_x000D_
    _x000D_
    _x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

live example: http://jsfiddle.net/choroshin/5YDJW/5/

Update:

or you can always try the popular ng-grid , ng-grid is good for sorting, searching, grouping etc, but I haven't tested it yet on a large scale data.

How can bcrypt have built-in salts?

To make things even more clearer,

Registeration/Login direction ->

The password + salt is encrypted with a key generated from the: cost, salt and the password. we call that encrypted value the cipher text. then we attach the salt to this value and encoding it using base64. attaching the cost to it and this is the produced string from bcrypt:

$2a$COST$BASE64

This value is stored eventually.

What the attacker would need to do in order to find the password ? (other direction <- )

In case the attacker got control over the DB, the attacker will decode easily the base64 value, and then he will be able to see the salt. the salt is not secret. though it is random. Then he will need to decrypt the cipher text.

What is more important : There is no hashing in this process, rather CPU expensive encryption - decryption. thus rainbow tables are less relevant here.

What exactly is the function of Application.CutCopyMode property in Excel

Normally, When you copy a cell you will find the below statement written down in the status bar (in the bottom of your sheet)

"Select destination and Press Enter or Choose Paste"

Then you press whether Enter or choose paste to paste the value of the cell.

If you didn't press Esc afterwards you will be able to paste the value of the cell several times

Application.CutCopyMode = False does the same like the Esc button, if you removed it from your code you will find that you are able to paste the cell value several times again.

And if you closed the Excel without pressing Esc you will get the warning 'There is a large amount of information on the Clipboard....'

Time part of a DateTime Field in SQL

SELECT DISTINCT   
                 CONVERT(VARCHAR(17), A.SOURCE_DEPARTURE_TIME, 108)  
FROM  
      CONSOLIDATED_LIST AS A  
WHERE   
      CONVERT(VARCHAR(17), A.SOURCE_DEPARTURE_TIME, 108) BETWEEN '15:00:00' AND '15:45:00'

omp parallel vs. omp parallel for

I am seeing starkly different runtimes when I take a for loop in g++ 4.7.0 and using

std::vector<double> x;
std::vector<double> y;
std::vector<double> prod;

for (int i = 0; i < 5000000; i++)
{
   double r1 = ((double)rand() / double(RAND_MAX)) * 5;
   double r2 = ((double)rand() / double(RAND_MAX)) * 5;
   x.push_back(r1);
   y.push_back(r2);
}

int sz = x.size();

#pragma omp parallel for

for (int i = 0; i< sz; i++)
   prod[i] = x[i] * y[i];

the serial code (no openmp ) runs in 79 ms. the "parallel for" code runs in 29 ms. If I omit the for and use #pragma omp parallel, the runtime shoots up to 179ms, which is slower than serial code. (the machine has hw concurrency of 8)

the code links to libgomp

How to convert SQL Query result to PANDAS Data Structure?

This question is old, but I wanted to add my two-cents. I read the question as " I want to run a query to my [my]SQL database and store the returned data as Pandas data structure [DataFrame]."

From the code it looks like you mean mysql database and assume you mean pandas DataFrame.

import MySQLdb as mdb
import pandas.io.sql as sql
from pandas import *

conn = mdb.connect('<server>','<user>','<pass>','<db>');
df = sql.read_frame('<query>', conn)

For example,

conn = mdb.connect('localhost','myname','mypass','testdb');
df = sql.read_frame('select * from testTable', conn)

This will import all rows of testTable into a DataFrame.

How to put a UserControl into Visual Studio toolBox

I found that the user control must have a parameterless constructor or it won't show up in the list. at least that was true in vs2005.

twitter bootstrap 3.0 typeahead ajax example

I'm using this https://github.com/biggora/bootstrap-ajax-typeahead

The result of code using Codeigniter/PHP

<pre>

$("#produto").typeahead({
        onSelect: function(item) {
            console.log(item);
            getProductInfs(item);
        },
        ajax: {
            url: path + 'produto/getProdName/',
            timeout: 500,
            displayField: "concat",
            valueField: "idproduto",
            triggerLength: 1,
            method: "post",
            dataType: "JSON",
            preDispatch: function (query) {
                showLoadingMask(true);
                return {
                    search: query
                }
            },
            preProcess: function (data) {

                if (data.success === false) {
                    return false;
                }else{
                    return data;    
                }                
            }               
        }
    });
</pre>   

How to check if a file exists from inside a batch file

C:\>help if

Performs conditional processing in batch programs.

IF [NOT] ERRORLEVEL number command

IF [NOT] string1==string2 command

IF [NOT] EXIST filename command

How do I update an entity using spring-data-jpa?

spring data save() method will help you to perform both: adding new item and updating an existed item.

Just call the save() and enjoy the life :))

Why is list initialization (using curly braces) better than the alternatives?

There are already great answers about the advantages of using list initialization, however my personal rule of thumb is NOT to use curly braces whenever possible, but instead make it dependent on the conceptual meaning:

  • If the object I'm creating conceptually holds the values I'm passing in the constructor (e.g. containers, POD structs, atomics, smart pointers etc.), then I'm using the braces.
  • If the constructor resembles a normal function call (it performs some more or less complex operations that are parametrized by the arguments) then I'm using the normal function call syntax.
  • For default initialization I always use curly braces.
    For one, that way I'm always sure that the object gets initialized irrespective of whether it e.g. is a "real" class with a default constructor that would get called anyway or a builtin / POD type. Second it is - in most cases - consistent with the first rule, as a default initialized object often represents an "empty" object.

In my experience, this ruleset can be applied much more consistently than using curly braces by default, but having to explicitly remember all the exceptions when they can't be used or have a different meaning than the "normal" function-call syntax with parenthesis (calls a different overload).

It e.g. fits nicely with standard library-types like std::vector:

vector<int> a{10,20};   //Curly braces -> fills the vector with the arguments

vector<int> b(10,20);   //Parentheses -> uses arguments to parametrize some functionality,                          
vector<int> c(it1,it2); //like filling the vector with 10 integers or copying a range.

vector<int> d{};      //empty braces -> default constructs vector, which is equivalent
                      //to a vector that is filled with zero elements

Tkinter: "Python may not be configured for Tk"

Install tk-devel (or a similarly-named package) before building Python.

Check if a variable is null in plsql

In PL/SQL you can't use operators such as '=' or '<>' to test for NULL because all comparisons to NULL return NULL. To compare something against NULL you need to use the special operators IS NULL or IS NOT NULL which are there for precisely this purpose. Thus, instead of writing

IF var = NULL THEN...

you should write

IF VAR IS NULL THEN...

In the case you've given you also have the option of using the NVL built-in function. NVL takes two arguments, the first being a variable and the second being a value (constant or computed). NVL looks at its first argument and, if it finds that the first argument is NULL, returns the second argument. If the first argument to NVL is not NULL, the first argument is returned. So you could rewrite

IF var IS NULL THEN
  var := 5;
END IF;

as

var := NVL(var, 5);

I hope this helps.

EDIT

And because it's nearly ten years since I wrote this answer, let's celebrate by expanding it just a bit.

The COALESCE function is the ANSI equivalent of Oracle's NVL. It differs from NVL in a couple of IMO good ways:

  1. It takes any number of arguments, and returns the first one which is not NULL. If all the arguments passed to COALESCE are NULL, it returns NULL.

  2. In contrast to NVL, COALESCE only evaluates arguments if it must, while NVL evaluates both of its arguments and then determines if the first one is NULL, etc. So COALESCE can be more efficient, because it doesn't spend time evaluating things which won't be used (and which can potentially cause unwanted side effects), but it also means that COALESCE is not a 100% straightforward drop-in replacement for NVL.

When do you use the "this" keyword?

I use it when, in a function that accepts a reference to an object of the same type, I want to make it perfectly clear which object I'm referring to, where.

For example

class AABB
{
  // ... members
  bool intersects( AABB other )
  {
    return other.left() < this->right() &&
           this->left() < other.right() &&

           // +y increases going down
           other.top() < this->bottom() &&
           this->top() < other.bottom() ;
  }
} ;

(vs)

class AABB
{
  bool intersects( AABB other )
  {
    return other.left() < right() &&
           left() < other.right() &&

           // +y increases going down
           other.top() < bottom() &&
           top() < other.bottom() ;
  }
} ;

At a glance which AABB does right() refer to? The this adds a bit of a clarifier.

How to explicitly obtain post data in Spring MVC?

Another answer to the OP's exact question is to set the consumes content type to "text/plain" and then declare a @RequestBody String input parameter. This will pass the text of the POST data in as the declared String variable (postPayload in the following example).

Of course, this presumes your POST payload is text data (as the OP stated was the case).

Example:

    @RequestMapping(value = "/your/url/here", method = RequestMethod.POST, consumes = "text/plain")
    public ModelAndView someMethod(@RequestBody String postPayload) {    
        // ...    
    }

What are all the escape characters?

Java Escape Sequences:

\u{0000-FFFF}  /* Unicode [Basic Multilingual Plane only, see below] hex value 
                  does not handle unicode values higher than 0xFFFF (65535),
                  the high surrogate has to be separate: \uD852\uDF62
                  Four hex characters only (no variable width) */
\b             /* \u0008: backspace (BS) */
\t             /* \u0009: horizontal tab (HT) */
\n             /* \u000a: linefeed (LF) */
\f             /* \u000c: form feed (FF) */
\r             /* \u000d: carriage return (CR) */
\"             /* \u0022: double quote (") */
\'             /* \u0027: single quote (') */
\\             /* \u005c: backslash (\) */
\{0-377}       /* \u0000 to \u00ff: from octal value 
                  1 to 3 octal digits (variable width) */

The Basic Multilingual Plane is the unicode values from 0x0000 - 0xFFFF (0 - 65535). Additional planes can only be specified in Java by multiple characters: the egyptian heiroglyph A054 (laying down dude) is U+1303F / &#77887; and would have to be broken into "\uD80C\uDC3F" (UTF-16) for Java strings. Some other languages support higher planes with "\U0001303F".

Cannot find pkg-config error

For Ubuntu/Debian OS,

apt-get install -y pkg-config

For Redhat/Yum OS,

yum install -y pkgconfig

For Archlinux OS,

pacman -S pkgconf

Windows 7: unable to register DLL - Error Code:0X80004005

Use following command should work on windows 7. don't forget to enclose the dll name with full path in double quotations.

C:\Windows\SysWOW64>regsvr32 "c:\dll.name" 

Order data frame rows according to vector with specific order

I prefer to use ***_join in dplyr whenever I need to match data. One possible try for this

left_join(data.frame(name=target),df,by="name")

Note that the input for ***_join require tbls or data.frame

redirect to current page in ASP.Net

http://en.wikipedia.org/wiki/Post/Redirect/Get

The most common way to implement this pattern in ASP.Net is to use Response.Redirect(Request.RawUrl)

Consider the differences between Redirect and Transfer. Transfer really isn't telling the browser to forward to a clear form, it's simply returning a cleared form. That may or may not be what you want.

Response.Redirect() does not a waste round trip. If you post to a script that clears the form by Server.Transfer() and reload you will be asked to repost by most browsers since the last action was a HTTP POST. This may cause your users to unintentionally repeat some action, eg. place a second order which will have to be voided later.

What is the meaning of "__attribute__((packed, aligned(4))) "

The attribute packed means that the compiler will not add padding between fields of the struct. Padding is usually used to make fields aligned to their natural size, because some architectures impose penalties for unaligned access or don't allow it at all.

aligned(4) means that the struct should be aligned to an address that is divisible by 4.

How to tag docker image with docker-compose

It seems the docs/tool have been updated and you can now add the image tag to your script. This was successful for me.

Example:

version: '2'
services:

  baggins.api.rest:
    image: my.image.name:rc2
    build:
      context: ../..
      dockerfile: app/Docker/Dockerfile.release
    ports:
      ...

https://docs.docker.com/compose/compose-file/#build

How to solve the “failed to lazily initialize a collection of role” Hibernate exception

Hi All posting quite late hope it helps others, Thanking in advance to @GMK for this post Hibernate.initialize(object)

when Lazy="true"

Set<myObject> set=null;
hibernateSession.open
set=hibernateSession.getMyObjects();
hibernateSession.close();

now if i access 'set' after closing session it throws exception.

My solution :

Set<myObject> set=new HashSet<myObject>();
hibernateSession.open
set.addAll(hibernateSession.getMyObjects());
hibernateSession.close();

now i can access 'set' even after closing Hibernate Session.

How to print a percentage value in python?

There is a way more convenient 'percent'-formatting option for the .format() format method:

>>> '{:.1%}'.format(1/3.0)
'33.3%'

Imported a csv-dataset to R but the values becomes factors

None of these answers mention the colClasses argument which is another way to specify the variable classes in read.csv.

 stuckey <- read.csv("C:/kalle/R/stuckey.csv", colClasses = "numeric") # all variables to numeric

or you can specify which columns to convert:

stuckey <- read.csv("C:/kalle/R/stuckey.csv", colClasses = c("PTS" = "numeric", "MP" = "numeric") # specific columns to numeric

Note that if a variable can't be converted to numeric then it will be converted to factor as default which makes it more difficult to convert to number. Therefore, it can be advisable just to read all variables in as 'character' colClasses = "character" and then convert the specific columns to numeric once the csv is read in:

stuckey <- read.csv("C:/kalle/R/stuckey.csv", colClasses = "character")
point <- as.numeric(stuckey$PTS)
time <- as.numeric(stuckey$MP)

What does [object Object] mean? (JavaScript)

Another option is to use JSON.stringify(obj)

For example:

exampleObj = {'a':1,'b':2,'c':3};
alert(JSON.stringify(exampleObj))

https://www.w3schools.com/js/js_json_stringify.asp

Insert data using Entity Framework model

var context = new DatabaseEntities();

var t = new test //Make sure you have a table called test in DB
{
    ID = Guid.NewGuid(),
    name = "blah",
};

context.test.Add(t);
context.SaveChanges();

Should do it

TOMCAT - HTTP Status 404

  1. Click on Window > Show view > Server or right click on the server in "Servers" view, select "Properties".
  2. In the "General" panel, click on the "Switch Location" button.
  3. The "Location: [workspace metadata]" should replace by something else.
  4. Open the Overview screen for the server by double clicking it.
  5. In the Server locations tab , select "Use Tomcat location".
  6. Save the configurations and restart the Server.

You may want to follow the steps above before starting the server. Because server location section goes grayed-unreachable.

server Locations in eclipse view

VSCode cannot find module '@angular/core' or any other modules

Executing the following two commands solves the problem for me:

npm install -g @angular/cli
ng update --all --force

How to access the last value in a vector?

I use the tail function:

tail(vector, n=1)

The nice thing with tail is that it works on dataframes too, unlike the x[length(x)] idiom.

Import and insert sql.gz file into database with putty

If you have scp then:

To move your file from local to remote:

$scp /home/user/file.gz user@ipaddress:path/to/file.gz 

To move your file from remote to local:

$scp user@ipaddress:path/to/file.gz /home/user/file.gz

To export your mysql file without login in to remote system:

$mysqldump -h ipaddressofremotehost -Pportnumber -u usernameofmysql -p  databasename | gzip -9 > databasename.sql.gz

To import your mysql file withoug login in to remote system:

$gunzip < databasename.sql.gz | mysql -h ipaddressofremotehost -Pportnumber -u usernameofmysql -p 

Note: Make sure you have network access to the ipaddress of remote host

To check network access:

$ping ipaddressofremotehost

How to get just one file from another branch

To restore a file from another branch, simply use the following command from your working branch:

git restore -s my-other-branch -- ./path/to/file

The -s flag is short for source i.e. the branch from where you want to pull the file.

(The chosen answer is very informative but also a bit overwhelming.)

Bad Request - Invalid Hostname IIS7

Check your local hosts file (C:\Windows\System32\drivers\etc\hosts for example). In my case I had previously used this to point a URL to a dev box and then forgotten about it. When I then reused the same URL I kept getting Bad Request (Invalid Hostname) because the traffic was going to the wrong server.

Android: combining text & image on a Button or ImageButton

You can use this:

  <Button
                    android:id="@+id/reset_all"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginRight="5dp"
                    android:layout_weight="1"
                    android:background="@drawable/btn_med"
                    android:text="Reset all"
                    android:textColor="#ffffff" />

                <Button
                    android:id="@+id/undo"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="5dp"
                    android:layout_weight="1"
                    android:background="@drawable/btn_med"
                    android:text="Undo"
                    android:textColor="#ffffff" />

in that i have put an image as background and also added text..!

How to reload/refresh jQuery dataTable?

Very Simple answer

$("#table_name").DataTable().ajax.reload(null, false); 

PYODBC--Data source name not found and no default driver specified

Do not put a space after the Driver keyword in the connection string.

This fails on Windows ...

conn_str = (
    r'DRIVER = {SQL Server};'
    r'SERVER=(local)\SQLEXPRESS;'
    r'DATABASE=myDb;'
    r'Trusted_Connection=yes;'
)
cnxn = pyodbc.connect(conn_str)

... but this works:

conn_str = (
    r'DRIVER={SQL Server};'
    r'SERVER=(local)\SQLEXPRESS;'
    r'DATABASE=myDb;'
    r'Trusted_Connection=yes;'
)
cnxn = pyodbc.connect(conn_str)

How to trigger Jenkins builds remotely and to pass parameters

You can simply try it with a jenkinsfile. Create a Jenkins job with following pipeline script.

pipeline {
    agent any

    parameters {
        booleanParam(defaultValue: true, description: '', name: 'userFlag')
    }

    stages {
        stage('Trigger') {
            steps {
                script {
                    println("triggering the pipeline from a rest call...")
                }
            }
        }
        stage("foo") {
            steps {
                echo "flag: ${params.userFlag}"
            }
        }

    }
}

Build the job once manually to get it configured & just create a http POST request to the Jenkins job as follows.

The format is http://server/job/myjob/buildWithParameters?PARAMETER=Value

curl http://admin:test123@localhost:30637/job/apd-test/buildWithParameters?userFlag=false --request POST

Difference between / and /* in servlet mapping url pattern

The essential difference between /* and / is that a servlet with mapping /* will be selected before any servlet with an extension mapping (like *.html), while a servlet with mapping / will be selected only after extension mappings are considered (and will be used for any request which doesn't match anything else---it is the "default servlet").

In particular, a /* mapping will always be selected before a / mapping. Having either prevents any requests from reaching the container's own default servlet.

Either will be selected only after servlet mappings which are exact matches (like /foo/bar) and those which are path mappings longer than /* (like /foo/*). Note that the empty string mapping is an exact match for the context root (http://host:port/context/).

See Chapter 12 of the Java Servlet Specification, available in version 3.1 at http://download.oracle.com/otndocs/jcp/servlet-3_1-fr-eval-spec/index.html.

Truncate (not round) decimal places in SQL Server

Round has an optional parameter

Select round(123.456, 2, 1)  will = 123.45
Select round(123.456, 2, 0)  will = 123.46

How to check for the type of a template parameter?

Use is_same:

#include <type_traits>

template <typename T>
void foo()
{
    if (std::is_same<T, animal>::value) { /* ... */ }  // optimizable...
}

Usually, that's a totally unworkable design, though, and you really want to specialize:

template <typename T> void foo() { /* generic implementation  */ }

template <> void foo<animal>()   { /* specific for T = animal */ }

Note also that it's unusual to have function templates with explicit (non-deduced) arguments. It's not unheard of, but often there are better approaches.

Stop node.js program from command line

you can work following command to be specific in localserver kill(here: 8000)

http://localhost:8000/ kill PID(processId):

$:lsof -i tcp:8000

It will give you following groups of TCPs:

COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME

node 21521 ubuntu 12u IPv6 345668 0t0 TCP *:8000 (LISTEN)

$:kill -9 21521

It will kill processId corresponding to TCP*:8000

disable textbox using jquery?

$(document).ready(function () {
   $("#txt1").attr("onfocus", "blur()");
});

_x000D_
_x000D_
$(document).ready(function () {_x000D_
  $("#txt1").attr("onfocus", "blur()");_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>_x000D_
_x000D_
<input id="txt1">
_x000D_
_x000D_
_x000D_

How do you put an image file in a json object?

To upload files directly to Mongo DB you can make use of Grid FS. Although I will suggest you to upload the file anywhere in file system and put the image's url in the JSON object for every entry and then when you call the data for specific object you can call for the image using URL.

Tell me which backend technology are you using? I can give more suggestions based on that.

Check that a variable is a number in UNIX shell

if echo $var | egrep -q '^[0-9]+$'; then
    # $var is a number
else
    # $var is not a number
fi

How to skip the OPTIONS preflight request?

setting the content-type to undefined would make javascript pass the header data As it is , and over writing the default angular $httpProvider header configurations. Angular $http Documentation

$http({url:url,method:"POST", headers:{'Content-Type':undefined}).then(success,failure);

Import a module from a relative path

The easiest method is to use sys.path.append().

However, you may be also interested in the imp module. It provides access to internal import functions.

# mod_name is the filename without the .py/.pyc extention
py_mod = imp.load_source(mod_name,filename_path) # Loads .py file
py_mod = imp.load_compiled(mod_name,filename_path) # Loads .pyc file 

This can be used to load modules dynamically when you don't know a module's name.

I've used this in the past to create a plugin type interface to an application, where the user would write a script with application specific functions, and just drop thier script in a specific directory.

Also, these functions may be useful:

imp.find_module(name[, path])
imp.load_module(name, file, pathname, description)

JFrame Maximize window

The way to set JFrame to full-screen, is to set MAXIMIZED_BOTH option which stands for MAXIMIZED_VERT | MAXIMIZED_HORIZ, which respectively set the frame to maximize vertically and horizontally

package Example;
import java.awt.GraphicsConfiguration;
import javax.swing.JFrame;
import javax.swing.JButton;

public class JFrameExample
{
    static JFrame frame;
    static GraphicsConfiguration gc;
    public static void main(String[] args)
    {
        frame = new JFrame(gc);
        frame.setTitle("Full Screen Example");
        frame.setExtendedState(MAXIMIZED_BOTH);

        JButton button = new JButton("exit");
        b.addActionListener(new ActionListener(){@Override
        public void actionPerformed(ActionEvent arg0){
            JFrameExample.frame.dispose();
            System.exit(0);
        }});

        frame.add(button);
        frame.setVisible(true);
    }
}

Content Security Policy "data" not working for base64 Images in Chrome 28

Try this

data to load:

<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 4 5'><path fill='#343a40' d='M2 0L0 2h4zm0 5L0 3h4z'/></svg>

get a utf8 to base64 convertor and convert the "svg" string to:

PHN2ZyB4bWxucz0naHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmcnIHZpZXdCb3g9JzAgMCA0IDUn
PjxwYXRoIGZpbGw9JyMzNDNhNDAnIGQ9J00yIDBMMCAyaDR6bTAgNUwwIDNoNHonLz48L3N2Zz4=

and the CSP is

img-src data: image/svg+xml;base64,PHN2ZyB4bWxucz0naHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmcnIHZpZXdCb3g9JzAgMCA0IDUn
PjxwYXRoIGZpbGw9JyMzNDNhNDAnIGQ9J00yIDBMMCAyaDR6bTAgNUwwIDNoNHonLz48L3N2Zz4=

How to center an iframe horizontally?

best way and more simple to center an iframe on your webpage is :

<p align="center"><iframe src="http://www.google.com/" width=500 height="500"></iframe></p>

where width and height will be the size of your iframe in your html page.

View/edit ID3 data for MP3 files

TagLib Sharp has support for reading ID3 tags.

Removing underline with href attribute

Add a style with the attribute text-decoration:none;:

There are a number of different ways of doing this.

Inline style:

<a href="xxx.html" style="text-decoration:none;">goto this link</a>

Inline stylesheet:

<html>
<head>
<style type="text/css">
   a {
      text-decoration:none;
   }
</style>
</head>
<body>
<a href="xxx.html">goto this link</a>
</body>
</html>

External stylesheet:

<html>
<head>
<link rel="Stylesheet" href="stylesheet.css" />
</head>
<body>
<a href="xxx.html">goto this link</a>
</body>
</html>

stylesheet.css:

a {
      text-decoration:none;
   }

Multiple select in Visual Studio?

Update: MixEdit extension now provides this ability.

MultiEdit extension for VS allows for something similar (doesn't support multiple selections as of this writing, just multiple carets)

Head over to Hanselman's for a quick animated gif of this in action: Simultaneous Editing for Visual Studio with the free MultiEdit extension

Simple linked list in C++

Below is a sample linkedlist

    #include <string>
    #include <iostream>

    using namespace std;


    template<class T>
    class Node
    {
    public:
        Node();
        Node(const T& item, Node<T>* ptrnext = NULL);
        T value;
        Node<T> * next;
    };

    template<class T>
    Node<T>::Node()
    {
        value = NULL;
        next = NULL;
    }
    template<class T>
    Node<T>::Node(const T& item, Node<T>* ptrnext = NULL)
    {
        this->value = item;
        this->next = ptrnext;
    }

    template<class T>
    class LinkedListClass
    {
    private:
        Node<T> * Front;
        Node<T> * Rear;
        int Count;
    public:
        LinkedListClass();
        ~LinkedListClass();
        void InsertFront(const T Item);
        void InsertRear(const T Item);
        void PrintList();
    };
    template<class T>
    LinkedListClass<T>::LinkedListClass()
    {
        Front = NULL;
        Rear = NULL;
    }

    template<class T>
    void LinkedListClass<T>::InsertFront(const T  Item)
    {
        if (Front == NULL)
        {
            Front = new Node<T>();
            Front->value = Item;
            Front->next = NULL;
            Rear = new Node<T>();
            Rear = Front;
        }
        else
        {
            Node<T> * newNode = new Node<T>();
            newNode->value = Item;
            newNode->next = Front;
            Front = newNode;
        }
    }

    template<class T>
    void LinkedListClass<T>::InsertRear(const T  Item)
    {
        if (Rear == NULL)
        {
            Rear = new Node<T>();
            Rear->value = Item;
            Rear->next = NULL;
            Front = new Node<T>();
            Front = Rear;
        }
        else
        {
            Node<T> * newNode = new Node<T>();
            newNode->value = Item;
            Rear->next = newNode;
            Rear = newNode;
        }
    }
    template<class T>
    void LinkedListClass<T>::PrintList()
    {
        Node<T> *  temp = Front;
        while (temp->next != NULL)
        {
            cout << " " << temp->value << "";
            if (temp != NULL)
            {
                temp = (temp->next);
            }
            else
            {
                break;
            }
        }
    }

    int main()
    {
        LinkedListClass<int> * LList = new LinkedListClass<int>();
        LList->InsertFront(40);
        LList->InsertFront(30);
        LList->InsertFront(20);
        LList->InsertFront(10);
        LList->InsertRear(50);
        LList->InsertRear(60);
        LList->InsertRear(70);
        LList->PrintList();
    }

How to convert hex strings to byte values in Java

String str = "Your string";

byte[] array = str.getBytes();

How can you flush a write using a file descriptor?

Have you tried disabling buffering?

setvbuf(fd, NULL, _IONBF, 0);

How to get first item from a java.util.Set?

Vector has some handy features:

Vector<String> siteIdVector = new Vector<>(siteIdSet);
String first = siteIdVector.firstElement();
String last = siteIdVector.lastElement();

But I do agree - this may have unintended consequences, since the underling set is not guaranteed to be ordered.

Appending HTML string to the DOM

Use insertAdjacentHTML if it's available, otherwise use some sort of fallback. insertAdjacentHTML is supported in all current browsers.

div.insertAdjacentHTML( 'beforeend', str );

Live demo: http://jsfiddle.net/euQ5n/

jinja2.exceptions.TemplateNotFound error

I think you shouldn't prepend themesDir. You only pass the filename of the template to flask, it will then look in a folder called templates relative to your python file.

What is boilerplate code?

Boilerplate code means a piece of code which can be used over and over again. On the other hand, anyone can say that it's a piece of reusable code.

The term actually came from the steel industries.

For a little bit of history, according to Wikipedia:

In the 1890s, boilerplate was actually cast or stamped in metal ready for the printing press and distributed to newspapers around the United States. Until the 1950s, thousands of newspapers received and used this kind of boilerplate from the nation's largest supplier, the Western Newspaper Union. Some companies also sent out press releases as boilerplate so that they had to be printed as written.

Now according to Wikipedia:

In object-oriented programs, classes are often provided with methods for getting and setting instance variables. The definitions of these methods can frequently be regarded as boilerplate. Although the code will vary from one class to another, it is sufficiently stereotypical in structure that it would be better generated automatically than written by hand. For example, in the following Java class representing a pet, almost all the code is boilerplate except for the declarations of Pet, name and owner:

public class Pet {
    private PetName name;
    private Person owner;

    public Pet(PetName name, Person owner) {
        this.name = name;
        this.owner = owner;
    }

    public PetName getName() {
        return name;
    }

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

    public Person getOwner() {
        return owner;
    }

    public void setOwner(Person owner) {
        this.owner = owner;
    }
}

Fully change package name including company domain

current package : com.company.name

New package : com.mycomapny.name

Steps: 1) Suppose you are at this screen which is shown below.

enter image description here

2) Open project pane and click on settings icon.

3) Deselect Compact Empty Middle Packages.

4) Then your package is now broken into individual parts as shown below .

5) right click on "company" select Refactor -> select rename ->rename directory.

enter image description here

6) Now your "company" has been changed to new "mycomapny" and changes were reflected as shown in below figure.

enter image description here

7) Now change the package name in AndroidManifest.xml file .

enter image description here

8) Open app level build.gradle and change package name .

enter image description here

9) you will get errors as Cannot resolve symbol "R" .

10) Remove line which gives this error and studio will import new R file automatically.

11) If you have multiple files then use find and replace option by pressing " Cntrl+Shift+R "

Or " Select Edit->Find->Replace in path.."

enter image description here

12) select Replace All.

How do you select a particular option in a SELECT element in jQuery?

A selector to get the middle option-element by value is

$('.selDiv option[value="SEL1"]')

For an index:

$('.selDiv option:eq(1)')

For a known text:

$('.selDiv option:contains("Selection 1")')

EDIT: As commented above the OP might have been after changing the selected item of the dropdown. In version 1.6 and higher the prop() method is recommended:

$('.selDiv option:eq(1)').prop('selected', true)

In older versions:

$('.selDiv option:eq(1)').attr('selected', 'selected')

EDIT2: after Ryan's comment. A match on "Selection 10" might be unwanted. I found no selector to match the full text, but a filter works:

 $('.selDiv option')
    .filter(function(i, e) { return $(e).text() == "Selection 1"})

EDIT3: Use caution with $(e).text() as it can contain a newline making the comparison fail. This happens when the options are implicitly closed (no </option> tag):

<select ...>
<option value="1">Selection 1
<option value="2">Selection 2
   :
</select>

If you simply use e.text any extra whitespace like the trailing newline will be removed, making the comparison more robust.

Java "user.dir" property - what exactly does it mean?

Typically this is the directory where your app (java) was started (working dir). "Typically" because it can be changed, eg when you run an app with Runtime.exec(String[] cmdarray, String[] envp, File dir)

Undefined function mysql_connect()

In php.ini file

change this

;extension=php_mysql.dll

into

extension=php_mysql.dll

Can you get the column names from a SqlDataReader?

I use the GetSchemaTable method, which is exposed via the IDataReader interface.

How to restart remote MySQL server running on Ubuntu linux?

  1. SSH into the machine. Using the proper credentials and ip address, ssh [email protected]. This should provide you with shell access to the Ubuntu server.
  2. Restart the mySQL service. sudo service mysql restart should do the job.

If your mySQL service is named something else like mysqld you may have to change the command accordingly or try this: sudo /etc/init.d/mysql restart

C# Select elements in list as List of string

List<string> empnames = emplist.Select(e => e.Ename).ToList();

This is an example of Projection in Linq. Followed by a ToList to resolve the IEnumerable<string> into a List<string>.

Alternatively in Linq syntax (head compiled):

var empnamesEnum = from emp in emplist 
                   select emp.Ename;
List<string> empnames = empnamesEnum.ToList();

Projection is basically representing the current type of the enumerable as a new type. You can project to anonymous types, another known type by calling constructors etc, or an enumerable of one of the properties (as in your case).

For example, you can project an enumerable of Employee to an enumerable of Tuple<int, string> like so:

var tuples = emplist.Select(e => new Tuple<int, string>(e.EID, e.Ename));

Batch file FOR /f tokens

for /f "tokens=* delims= " %%f in (myfile) do

This reads a file line-by-line, removing leading spaces (thanks, jeb).

set line=%%f

sets then the line variable to the line just read and

call :procesToken

calls a subroutine that does something with the line

:processToken

is the start of the subroutine mentioned above.

for /f "tokens=1* delims=/" %%a in ("%line%") do

will then split the line at /, but stopping tokenization after the first token.

echo Got one token: %%a

will output that first token and

set line=%%b

will set the line variable to the rest of the line.

if not "%line%" == "" goto :processToken

And if line isn't yet empty (i.e. all tokens processed), it returns to the start, continuing with the rest of the line.

php - push array into array - key issue

Use this..

$res_arr_values = array();
while ($row = mysql_fetch_array($result, MYSQL_ASSOC))
{
    $res_arr_values[] = $row;
}

How can I perform a str_replace in JavaScript, replacing text in JavaScript?

Added a method replace_in_javascript which will satisfy your requirement. Also found that you are writing a string "new_text" in document.write() which is supposed to refer to a variable new_text.

_x000D_
_x000D_
let replace_in_javascript= (replaceble, replaceTo, text) => {_x000D_
  return text.replace(replaceble, replaceTo)_x000D_
}_x000D_
_x000D_
var text = "this is some sample text that i want to replace";_x000D_
var new_text = replace_in_javascript("want", "dont want", text);_x000D_
document.write(new_text);
_x000D_
_x000D_
_x000D_

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

it's not a login issue most times. The database might not have been created. To create the database, Go to db context file and add this.Database.EnsureCreated();

HTML character codes for this ? or this ?

I usually use the excellent Gucharmap to look up Unicode characters. It's installed on all recent Linux installations with Gnome under the name "Character Map". I don't know of any equivalent tools for Windows or Mac OS X, but its homepage lists a few.

Is there a way to make mv create the directory to be moved to if it doesn't exist?

You can even use brace extensions:

mkdir -p directory{1..3}/subdirectory{1..3}/subsubdirectory{1..2}      
  • which creates 3 directories (directory1, directory2, directory3),
    • and in each one of them two subdirectories (subdirectory1, subdirectory2),
      • and in each of them two subsubdirectories (subsubdirectory1 and subsubdirectory2).

You have to use bash 3.0 or newer.

UPDATE with CASE and IN - Oracle

Use to_number to convert budgpost to a number:

when to_number(budgpost,99999) in (1001,1012,50055) THEN 'BP_GR_A' 

EDIT: Make sure there are enough 9's in to_number to match to largest budget post.

If there are non-numeric budget posts, you could filter them out with a where clause at then end of the query:

where regexp_like(budgpost, '^-?[[:digit:],.]+$')

Pass by pointer & Pass by reference

Use references all the time and pointers only when you have to refer to NULL which reference cannot refer.

See this FAQ : http://www.parashift.com/c++-faq-lite/references.html#faq-8.6

"document.getElementByClass is not a function"

As others have said, you're not using the right function name and it doesn't exist univerally in all browsers.

If you need to do cross-browser fetching of anything other than an element with an id with document.getElementById(), then I would strongly suggest you get a library that supports CSS3 selectors across all browsers. It will save you a massive amount of development time, testing and bug fixing. The easiest thing to do is to just use jQuery because it's so widely available, has excellent documentation, has free CDN access and has an excellent community of people behind it to answer questions. If that seems like more than you need, then you can get Sizzle which is just a selector library (it's actually the selector engine inside of jQuery and others). I've used it by itself in other projects and it's easy, productive and small.

If you want to select multiple nodes at once, you can do that many different ways. If you give them all the same class, you can do that with:

var list = document.getElementsByClassName("myButton");
for (var i = 0; i < list.length; i++) {
    // list[i] is a node with the desired class name
}

and it will return a list of nodes that have that class name.

In Sizzle, it would be this:

var list = Sizzle(".myButton");
for (var i = 0; i < list.length; i++) {
    // list[i] is a node with the desired class name
}

In jQuery, it would be this:

$(".myButton").each(function(index, element) {
    // element is a node with the desired class name
});

In both Sizzle and jQuery, you can put multiple class names into the selector like this and use much more complicated and powerful selectors:

$(".myButton, .myInput, .homepage.gallery, #submitButton").each(function(index, element) {
    // element is a node that matches the selector
});

In Swift how to call method with parameters on GCD main thread?

Here's a nice little global function you can add for a nicer syntax:

func dispatch_on_main(block: dispatch_block_t) {
    dispatch_async(dispatch_get_main_queue(), block)
}

And usage

dispatch_on_main {
    // Do some UI stuff
}

How to drop rows of Pandas DataFrame whose value in a certain column is NaN

yet another solution which uses the fact that np.nan != np.nan:

In [149]: df.query("EPS == EPS")
Out[149]:
                 STK_ID  EPS  cash
STK_ID RPT_Date
600016 20111231  600016  4.3   NaN
601939 20111231  601939  2.5   NaN

Array of PHP Objects

Another intuitive solution could be:

class Post
{
    public $title;
    public $date;
}

$posts = array();

$posts[0] = new Post();
$posts[0]->title = 'post sample 1';
$posts[0]->date = '1/1/2021';

$posts[1] = new Post();
$posts[1]->title = 'post sample 2';
$posts[1]->date = '2/2/2021';

foreach ($posts as $post) {
  echo 'Post Title:' . $post->title . ' Post Date:' . $post->date . "\n";
}

forcing web-site to show in landscape mode only

@Golmaal really answered this, I'm just being a bit more verbose.

<style type="text/css">
    #warning-message { display: none; }
    @media only screen and (orientation:portrait){
        #wrapper { display:none; }
        #warning-message { display:block; }
    }
    @media only screen and (orientation:landscape){
        #warning-message { display:none; }
    }
</style>

....

<div id="wrapper">
    <!-- your html for your website -->
</div>
<div id="warning-message">
    this website is only viewable in landscape mode
</div>

You have no control over the user moving the orientation however you can at least message them. This example will hide the wrapper if in portrait mode and show the warning message and then hide the warning message in landscape mode and show the portrait.

I don't think this answer is any better than @Golmaal , only a compliment to it. If you like this answer, make sure to give @Golmaal the credit.

Update

I've been working with Cordova a lot recently and it turns out you CAN control it when you have access to the native features.

Another Update

So after releasing Cordova it is really terrible in the end. It is better to use something like React Native if you want JavaScript. It is really amazing and I know it isn't pure web but the pure web experience on mobile kind of failed.

Java Enum return Int

Simply call the ordinal() method on an enum value, to retrieve its corresponding number. There's no need to declare an addition attribute with its value, each enumerated value gets its own number by default, assigned starting from zero, incrementing by one for each value in the same order they were declared.

You shouldn't depend on the int value of an enum, only on its actual value. Enums in Java are a different kind of monster and are not like enums in C, where you depend on their integer code.

Regarding the example you provided in the question, Font.PLAIN works because that's just an integer constant of the Font class. If you absolutely need a (possibly changing) numeric code, then an enum is not the right tool for the job, better stick to numeric constants.

How can I list all tags for a Docker image on a remote registry?

You can use:

skopeo inspect docker://<REMOTE_REGISTRY> --authfile <PULL_SECRET> | jq .RepoTags

The connection to adb is down, and a severe error has occurred

For me the following worked:

  1. Kill adb.exe from Task Manager

  2. Restart Eclipse as administrator

  3. For my app, the target was Google APIs level 10.. I went to Window-> AVD Manager and the entry for "Google APIs level 10" had a broken instead of a green tick - so I just clicked the entry and clicked the "repair" button and problem was fixed

(It was probably only 3 above..)

What's the valid way to include an image with no src?

I found that simply setting the src to an empty string and adding a rule to your CSS to hide the broken image icon works just fine.

[src=''] {
    visibility: hidden;
}

Searching word in vim?

  1. vim filename
  2. press /
  3. type word which you want to search
  4. press Enter

How can I hide/show a div when a button is clicked?

The following solution is:

  • briefest. Somewhat similar to here. It's also minimal: The table in the DIV is orthogonal to your question.
  • fastest: getElementById is called once at the outset. This may or may not suit your purposes.
  • It uses pure JavaScript (i.e. without JQuery).
  • It uses a button. Your taste may vary.
  • extensible: it's ready to add more DIVs, sharing the code.

_x000D_
_x000D_
mydiv = document.getElementById("showmehideme");_x000D_
_x000D_
function showhide(d) {_x000D_
    d.style.display = (d.style.display !== "none") ? "none" : "block";_x000D_
}
_x000D_
#mydiv { background-color: #ddd; }
_x000D_
<button id="button" onclick="showhide(mydiv)">Show/Hide</button>_x000D_
<div id="showmehideme">_x000D_
    This div will show and hide on button click._x000D_
</div>
_x000D_
_x000D_
_x000D_

How to check is Apache2 is stopped in Ubuntu?

You can also type "top" and look at the list of running processes.

What does mysql error 1025 (HY000): Error on rename of './foo' (errorno: 150) mean?

Take a look in error file for your mysql database. According to Bug #26305 my sql do not give you the cause. This bug exists since MySQL 4.1 ;-)

Java - Find shortest path between 2 points in a distance weighted map

This maybe too late but No one provided a clear explanation of how the algorithm works

The idea of Dijkstra is simple, let me show this with the following pseudocode.

Dijkstra partitions all nodes into two distinct sets. Unsettled and settled. Initially all nodes are in the unsettled set, e.g. they must be still evaluated.

At first only the source node is put in the set of settledNodes. A specific node will be moved to the settled set if the shortest path from the source to a particular node has been found.

The algorithm runs until the unsettledNodes set is empty. In each iteration it selects the node with the lowest distance to the source node out of the unsettledNodes set. E.g. It reads all edges which are outgoing from the source and evaluates each destination node from these edges which are not yet settled.

If the known distance from the source to this node can be reduced when the selected edge is used, the distance is updated and the node is added to the nodes which need evaluation.

Please note that Dijkstra also determines the pre-successor of each node on its way to the source. I left that out of the pseudo code to simplify it.

Credits to Lars Vogel

UL has margin on the left

I don't see any margin or margin-left declarations for #footer-wrap li.

This ought to do the trick:

#footer-wrap ul,
#footer-wrap li {
    margin-left: 0;
    list-style-type: none;
}

Detect if range is empty

Found a solution from the comments I got.

Sub TestIsEmpty()
    If WorksheetFunction.CountA(Range("A38:P38")) = 0 Then
        MsgBox "Empty"
    Else
        MsgBox "Not Empty"
    End If
End Sub

Simple function to sort an array of objects

var people = 
[{"name": 'a75',"item1": "false","item2":"false"}, 
{"name": 'z32',"item1": "true","item2":  "false"}, 
{"name": 'e77',"item1": "false","item2": "false"}]; 

function mycomparator(a,b) {   return parseInt(a.name) - parseInt(b.name);  } 
people.sort(mycomparator); 

something along the lines of this maybe (or as we used to say, this should work).

ExecuteReader: Connection property has not been initialized

All of the answers is true.This is another way. And I like this One

SqlCommand cmd = conn.CreateCommand()

you must notice that strings concat have a sql injection problem. Use the Parameters http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommand.parameters.aspx

Convert a string to a double - is this possible?

Use doubleval(). But be very careful about using decimals in financial transactions, and validate that user input very carefully.

How to fix the Eclipse executable launcher was unable to locate its companion shared library for windows 7?

This is an issue with the 64 bit version of Kepler and windows7 in my case. I downloaded the 32 bit and it worked immediately.

jQuery trigger event when click outside the element

I do not think document fires the click event. Try using the body element to capture the click event. Might need to check on that...

Field 'id' doesn't have a default value?

This is caused by MySQL having a strict mode set which won’t allow INSERT or UPDATE commands with empty fields where the schema doesn’t have a default value set.

There are a couple of fixes for this.

First ‘fix’ is to assign a default value to your schema. This can be done with a simple ALTER command:

ALTER TABLE `details` CHANGE COLUMN `delivery_address_id` `delivery_address_id` INT(11) NOT NULL DEFAULT 0 ;

However, this may need doing for many tables in your database schema which will become tedious very quickly. The second fix is to remove sql_mode STRICT_TRANS_TABLES on the mysql server.

If you are using a brew installed MySQL you should edit the my.cnf file in the MySQL directory. Change the sql_mode at the bottom:

#sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
sql_mode=NO_ENGINE_SUBSTITUTION

Save the file and restart Mysql.

Source: https://www.euperia.com/development/mysql-fix-field-doesnt-default-value/1509

Microsoft.ReportViewer.Common Version=12.0.0.0

I worked on this issue for a few days. Installed all packages, modified web.config and still had the same problem. I finally removed

<assemblies>
<add assembly="Microsoft.ReportViewer.Common, Version=12.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91" />
</assemblies>

from the web.config and it worked. No exactly sure why it didn't work with the tags in the web.config file. My guess there is a conflict with the GAC and the BIN folder.

Here is my web.config file:

<?xml version="1.0"?>
<configuration>
  <system.web>
    <compilation debug="true" targetFramework="4.5" />
    <httpRuntime targetFramework="4.5" />
    <httpHandlers>
      <add verb="*" path="Reserved.ReportViewerWebControl.axd" type="Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=12.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91" />     
    </httpHandlers>    
  </system.web>
  <system.webServer>
    <validation validateIntegratedModeConfiguration="false" />
    <handlers>
      <add name="ReportViewerWebControlHandler" preCondition="integratedMode" verb="*" path="Reserved.ReportViewerWebControl.axd" type="Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=12.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91" />      
    </handlers>
  </system.webServer>
</configuration>

How can I send JSON response in symfony2 controller

Since Symfony 3.1 you can use JSON Helper http://symfony.com/doc/current/book/controller.html#json-helper

public function indexAction()
{
// returns '{"username":"jane.doe"}' and sets the proper Content-Type header
return $this->json(array('username' => 'jane.doe'));

// the shortcut defines three optional arguments
// return $this->json($data, $status = 200, $headers = array(), $context = array());
}

How to set default vim colorscheme

Once you’ve decided to change vim color scheme that you like, you’ll need to configure vim configuration file ~/.vimrc.

For e.g. to use the elflord color scheme just add these lines to your ~/.vimrc file:

colo elflord

For other names of color schemes you can look in /usr/share/vim/vimNN/colors where NN - version of VIM.

How can I get a value from a map?

map.at("key") throws exception if missing key

If k does not match the key of any element in the container, the function throws an out_of_range exception.

http://www.cplusplus.com/reference/map/map/at/

drag drop files into standard html file input

_x000D_
_x000D_
//----------App.js---------------------//_x000D_
$(document).ready(function() {_x000D_
    var holder = document.getElementById('holder');_x000D_
    holder.ondragover = function () { this.className = 'hover'; return false; };_x000D_
    holder.ondrop = function (e) {_x000D_
      this.className = 'hidden';_x000D_
      e.preventDefault();_x000D_
      var file = e.dataTransfer.files[0];_x000D_
      var reader = new FileReader();_x000D_
      reader.onload = function (event) {_x000D_
          document.getElementById('image_droped').className='visible'_x000D_
          $('#image_droped').attr('src', event.target.result);_x000D_
      }_x000D_
      reader.readAsDataURL(file);_x000D_
    };_x000D_
});
_x000D_
.holder_default {_x000D_
    width:500px; _x000D_
    height:150px; _x000D_
    border: 3px dashed #ccc;_x000D_
}_x000D_
_x000D_
#holder.hover { _x000D_
    width:400px; _x000D_
    height:150px; _x000D_
    border: 3px dashed #0c0 !important; _x000D_
}_x000D_
_x000D_
.hidden {_x000D_
    visibility: hidden;_x000D_
}_x000D_
_x000D_
.visible {_x000D_
    visibility: visible;_x000D_
}
_x000D_
<!DOCTYPE html>_x000D_
_x000D_
<html>_x000D_
    <head>_x000D_
        <title> HTML 5 </title>_x000D_
        <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.js"></script>_x000D_
    </head>_x000D_
    <body>_x000D_
      <form method="post" action="http://example.com/">_x000D_
        <div id="holder" style="" id="holder" class="holder_default">_x000D_
          <img src="" id="image_droped" width="200" style="border: 3px dashed #7A97FC;" class=" hidden"/>_x000D_
        </div>_x000D_
      </form>_x000D_
    </body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Resource interpreted as stylesheet but transferred with MIME type text/html (seems not related with web server)

In case anyone comes to this post and has a similar issue. I just experienced a similar problem, but the solution was quite simple.

A developer had mistakenly dropped a copy of the web.config into the CSS directory. Once deleted, all errors were resolved and the page properly displayed.

Get IP address of visitors using Flask for Python

Proxies can make this a little tricky, make sure to check out ProxyFix (Flask docs) if you are using one. Take a look at request.environ in your particular environment. With nginx I will sometimes do something like this:

from flask import request   
request.environ.get('HTTP_X_REAL_IP', request.remote_addr)   

When proxies, such as nginx, forward addresses, they typically include the original IP somewhere in the request headers.

Update See the flask-security implementation. Again, review the documentation about ProxyFix before implementing. Your solution may vary based on your particular environment.

WebAPI to Return XML

Here's another way to be compatible with an IHttpActionResult return type. In this case I am asking it to use the XML Serializer(optional) instead of Data Contract serializer, I'm using return ResponseMessage( so that I get a return compatible with IHttpActionResult:

return ResponseMessage(new HttpResponseMessage(HttpStatusCode.OK)
       {
           Content = new ObjectContent<SomeType>(objectToSerialize, 
              new System.Net.Http.Formatting.XmlMediaTypeFormatter { 
                  UseXmlSerializer = true 
              })
       });

Remove all special characters from a string

Update

The solution below has a "SEO friendlier" version:

function hyphenize($string) {
    $dict = array(
        "I'm"      => "I am",
        "thier"    => "their",
        // Add your own replacements here
    );
    return strtolower(
        preg_replace(
          array( '#[\\s-]+#', '#[^A-Za-z0-9. -]+#' ),
          array( '-', '' ),
          // the full cleanString() can be downloaded from http://www.unexpectedit.com/php/php-clean-string-of-utf8-chars-convert-to-similar-ascii-char
          cleanString(
              str_replace( // preg_replace can be used to support more complicated replacements
                  array_keys($dict),
                  array_values($dict),
                  urldecode($string)
              )
          )
        )
    );
}

function cleanString($text) {
    $utf8 = array(
        '/[áàâãªä]/u'   =>   'a',
        '/[ÁÀÂÃÄ]/u'    =>   'A',
        '/[ÍÌÎÏ]/u'     =>   'I',
        '/[íìîï]/u'     =>   'i',
        '/[éèêë]/u'     =>   'e',
        '/[ÉÈÊË]/u'     =>   'E',
        '/[óòôõºö]/u'   =>   'o',
        '/[ÓÒÔÕÖ]/u'    =>   'O',
        '/[úùûü]/u'     =>   'u',
        '/[ÚÙÛÜ]/u'     =>   'U',
        '/ç/'           =>   'c',
        '/Ç/'           =>   'C',
        '/ñ/'           =>   'n',
        '/Ñ/'           =>   'N',
        '/–/'           =>   '-', // UTF-8 hyphen to "normal" hyphen
        '/[’‘‹›‚]/u'    =>   ' ', // Literally a single quote
        '/[“”«»„]/u'    =>   ' ', // Double quote
        '/ /'           =>   ' ', // nonbreaking space (equiv. to 0x160)
    );
    return preg_replace(array_keys($utf8), array_values($utf8), $text);
}

The rationale for the above functions (which I find way inefficient - the one below is better) is that a service that shall not be named apparently ran spelling checks and keyword recognition on the URLs.

After losing a long time on a customer's paranoias, I found out they were not imagining things after all -- their SEO experts [I am definitely not one] reported that, say, converting "Viaggi Economy Perù" to viaggi-economy-peru "behaved better" than viaggi-economy-per (the previous "cleaning" removed UTF8 characters; Bogotà became bogot, Medellìn became medelln and so on).

There were also some common misspellings that seemed to influence the results, and the only explanation that made sense to me is that our URL were being unpacked, the words singled out, and used to drive God knows what ranking algorithms. And those algorithms apparently had been fed with UTF8-cleaned strings, so that "Perù" became "Peru" instead of "Per". "Per" did not match and sort of took it in the neck.

In order to both keep UTF8 characters and replace some misspellings, the faster function below became the more accurate (?) function above. $dict needs to be hand tailored, of course.

Previous answer

A simple approach:

// Remove all characters except A-Z, a-z, 0-9, dots, hyphens and spaces
// Note that the hyphen must go last not to be confused with a range (A-Z)
// and the dot, NOT being special (I know. My life was a lie), is NOT escaped

$str = preg_replace('/[^A-Za-z0-9. -]/', '', $str);

// Replace sequences of spaces with hyphen
$str = preg_replace('/  */', '-', $str);

// The above means "a space, followed by a space repeated zero or more times"
// (should be equivalent to / +/)

// You may also want to try this alternative:
$str = preg_replace('/\\s+/', '-', $str);

// where \s+ means "zero or more whitespaces" (a space is not necessarily the
// same as a whitespace) just to be sure and include everything

Note that you might have to first urldecode() the URL, since %20 and + both are actually spaces - I mean, if you have "Never%20gonna%20give%20you%20up" you want it to become Never-gonna-give-you-up, not Never20gonna20give20you20up . You might not need it, but I thought I'd mention the possibility.

So the finished function along with test cases:

function hyphenize($string) {
    return 
    ## strtolower(
          preg_replace(
            array('#[\\s-]+#', '#[^A-Za-z0-9. -]+#'),
            array('-', ''),
        ##     cleanString(
              urldecode($string)
        ##     )
        )
    ## )
    ;
}

print implode("\n", array_map(
    function($s) {
            return $s . ' becomes ' . hyphenize($s);
    },
    array(
    'Never%20gonna%20give%20you%20up',
    "I'm not the man I was",
    "'Légeresse', dit sa majesté",
    )));


Never%20gonna%20give%20you%20up    becomes  never-gonna-give-you-up
I'm not the man I was              becomes  im-not-the-man-I-was
'Légeresse', dit sa majesté        becomes  legeresse-dit-sa-majeste

To handle UTF-8 I used a cleanString implementation found online (link broken since, but a stripped down copy with all the not-too-esoteric UTF8 characters is at the beginning of the answer; it's also easy to add more characters to it if you need) that converts UTF8 characters to normal characters, thus preserving the word "look" as much as possible. It could be simplified and wrapped inside the function here for performance.

The function above also implements converting to lowercase - but that's a taste. The code to do so has been commented out.

find files by extension, *.html under a folder in nodejs

node.js, recursive simple function:

var path = require('path'), fs=require('fs');

function fromDir(startPath,filter){

    //console.log('Starting from dir '+startPath+'/');

    if (!fs.existsSync(startPath)){
        console.log("no dir ",startPath);
        return;
    }

    var files=fs.readdirSync(startPath);
    for(var i=0;i<files.length;i++){
        var filename=path.join(startPath,files[i]);
        var stat = fs.lstatSync(filename);
        if (stat.isDirectory()){
            fromDir(filename,filter); //recurse
        }
        else if (filename.indexOf(filter)>=0) {
            console.log('-- found: ',filename);
        };
    };
};

fromDir('../LiteScript','.html');

add RegExp if you want to get fancy, and a callback to make it generic.

var path = require('path'), fs=require('fs');

function fromDir(startPath,filter,callback){

    //console.log('Starting from dir '+startPath+'/');

    if (!fs.existsSync(startPath)){
        console.log("no dir ",startPath);
        return;
    }

    var files=fs.readdirSync(startPath);
    for(var i=0;i<files.length;i++){
        var filename=path.join(startPath,files[i]);
        var stat = fs.lstatSync(filename);
        if (stat.isDirectory()){
            fromDir(filename,filter,callback); //recurse
        }
        else if (filter.test(filename)) callback(filename);
    };
};

fromDir('../LiteScript',/\.html$/,function(filename){
    console.log('-- found: ',filename);
});

How to convert ASCII code (0-255) to its corresponding character?

This is an example, which shows that by converting an int to char, one can determine the corresponding character to an ASCII code.

public class sample6
{
    public static void main(String... asf)
    {

        for(int i =0; i<256; i++)
        {
            System.out.println( i + ". " + (char)i);
        }
    }
}

Make header and footer files to be included in multiple html pages

It is also possible to load scripts and links into the header. I'll be adding it one of the examples above...

<!--load_essentials.js-->
document.write('<link rel="stylesheet" type="text/css" href="css/style.css" />');
document.write('<link rel="stylesheet" type="text/css" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css" />');
document.write('<script src="js/jquery.js" type="text/javascript"></script>');

document.getElementById("myHead").innerHTML =
"<span id='headerText'>Title</span>"
+ "<span id='headerSubtext'>Subtitle</span>";
document.getElementById("myNav").innerHTML =
"<ul id='navLinks'>"
+ "<li><a href='index.html'>Home</a></li>"
+ "<li><a href='about.html'>About</a>"
+ "<li><a href='donate.html'>Donate</a></li>"
+ "</ul>";
document.getElementById("myFooter").innerHTML =
"<p id='copyright'>Copyright &copy; " + new Date().getFullYear() + " You. All"
+ " rights reserved.</p>"
+ "<p id='credits'>Layout by You</p>"
+ "<p id='contact'><a href='mailto:[email protected]'>Contact Us</a> / "
+ "<a href='mailto:[email protected]'>Report a problem.</a></p>";

<!--HTML-->
<header id="myHead"></header>
<nav id="myNav"></nav>
Content
<footer id="myFooter"></footer>

<script src="load_essentials.js"></script>

make arrayList.toArray() return more specific types

A shorter version of converting List to Array of specific type (for example Long):

Long[] myArray = myList.toArray(Long[]::new);

IOError: [Errno 13] Permission denied

I had a similar problem. I was attempting to have a file written every time a user visits a website.

The problem ended up being twofold.

1: the permissions were not set correctly

2: I attempted to use
f = open(r"newfile.txt","w+") (Wrong)

After changing the file to 777 (all users can read/write)
chmod 777 /var/www/path/to/file
and changing the path to an absolute path, my problem was solved
f = open(r"/var/www/path/to/file/newfile.txt","w+") (Right)