Programs & Examples On #Sfx

How do I make a self extract and running installer

I have created step by step instructions on how to do this as I also was very confused about how to get this working.

How to make a self extracting archive that runs your setup.exe with 7zip -sfx switch

Here are the steps.

Step 1 - Setup your installation folder

To make this easy create a folder c:\Install. This is where we will copy all the required files.

Step 2 - 7Zip your installers

  1. Go to the folder that has your .msi and your setup.exe
  2. Select both the .msi and the setup.exe
  3. Right-Click and choose 7Zip --> "Add to Archive"
  4. Name your archive "Installer.7z" (or a name of your choice)
  5. Click Ok
  6. You should now have "Installer.7z".
  7. Copy this .7z file to your c:\Install directory

Step 3 - Get the 7z-Extra sfx extension module

You need to download 7zSD.sfx

  1. Download one of the LZMA packages from here
  2. Extract the package and find 7zSD.sfx in the bin folder.
  3. Copy the file "7zSD.sfx" to c:\Install

Step 4 - Setup your config.txt

I would recommend using NotePad++ to edit this text file as you will need to encode in UTF-8, the following instructions are using notepad++.

  1. Using windows explorer go to c:\Install
  2. right-click and choose "New Text File" and name it config.txt
  3. right-click and choose "Edit with NotePad++
  4. Click the "Encoding Menu" and choose "Encode in UTF-8"
  5. Enter something like this:

    ;!@Install@!UTF-8!
    Title="SOFTWARE v1.0.0.0"
    BeginPrompt="Do you want to install SOFTWARE v1.0.0.0?"
    RunProgram="setup.exe"
    ;!@InstallEnd@!
    

Edit this replacing [SOFTWARE v1.0.0.0] with your product name. Notes on the parameters and options for the setup file are here.

CheckPoint

You should now have a folder "c:\Install" with the following 3 files:

  1. Installer.7z
  2. 7zSD.sfx
  3. config.txt

Step 5 - Create the archive

These instructions I found on the web but nowhere did it explain any of the 4 steps above.

  1. Open a cmd window, Window + R --> cmd --> press enter
  2. In the command window type the following

    cd \
    cd Install
    copy /b 7zSD.sfx + config.txt + Installer.7z MyInstaller.exe
    
  3. Look in c:\Install and you will now see you have a MyInstaller.exe

  4. You are finished

Run the installer

Double click on MyInstaller.exe and it will prompt with your message. Click OK and the setup.exe will run.

P.S. Note on Automation

Now that you have this working in your c:\Install directory I would create an "Install.bat" file and put the copy script in it.

copy /b 7zSD.sfx + config.txt + Installer.7z MyInstaller.exe

Now you can just edit and run the Install.bat every time you need to rebuild a new version of you deployment package.

How to apply filters to *ngFor?

I'm not sure when it came in but they already made slice pipe that will do that. It's well documented too.

https://angular.io/docs/ts/latest/api/common/index/SlicePipe-pipe.html

<p *ngFor="let feature of content?.keyFeatures | slice:1:5">
   {{ feature.description }}
</p>

How to open a new tab in GNOME Terminal from command line?

Just in case, you want to open

  • a new window
  • with two tabs
  • and executing command in there
  • and having them stay open...

here you go:

gnome-terminal --geometry=73x16+0+0 --window \
  --working-directory=/depot --title='A' --command="bash -c ls;bash" \
  --tab --working-directory=/depot/kn --title='B' --command="bash -c ls;bash"

(same for mate-terminal btw.)

Algorithm to return all combinations of k elements from n

Short fast C implementation

#include <stdio.h>

void main(int argc, char *argv[]) {
  const int n = 6; /* The size of the set; for {1, 2, 3, 4} it's 4 */
  const int p = 4; /* The size of the subsets; for {1, 2}, {1, 3}, ... it's 2 */
  int comb[40] = {0}; /* comb[i] is the index of the i-th element in the combination */

  int i = 0;
  for (int j = 0; j <= n; j++) comb[j] = 0;
  while (i >= 0) {
    if (comb[i] < n + i - p + 1) {
       comb[i]++;
       if (i == p - 1) { for (int j = 0; j < p; j++) printf("%d ", comb[j]); printf("\n"); }
       else            { comb[++i] = comb[i - 1]; }
    } else i--; }
}

To see how fast it is, use this code and test it

#include <time.h>
#include <stdio.h>

void main(int argc, char *argv[]) {
  const int n = 32; /* The size of the set; for {1, 2, 3, 4} it's 4 */
  const int p = 16; /* The size of the subsets; for {1, 2}, {1, 3}, ... it's 2 */
  int comb[40] = {0}; /* comb[i] is the index of the i-th element in the combination */

  int c = 0; int i = 0;
  for (int j = 0; j <= n; j++) comb[j] = 0;
  while (i >= 0) {
    if (comb[i] < n + i - p + 1) {
       comb[i]++;
       /* if (i == p - 1) { for (int j = 0; j < p; j++) printf("%d ", comb[j]); printf("\n"); } */
       if (i == p - 1) c++;
       else            { comb[++i] = comb[i - 1]; }
    } else i--; }
  printf("%d!%d == %d combination(s) in %15.3f second(s)\n ", p, n, c, clock()/1000.0);
}

test with cmd.exe (windows):

Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

c:\Program Files\lcc\projects>combination
16!32 == 601080390 combination(s) in          5.781 second(s)

c:\Program Files\lcc\projects>

Have a nice day.

How to get a single value from FormGroup

Another option:

this.form.value['nameOfControl']

How to resolve the error "Unable to access jarfile ApacheJMeter.jar errorlevel=1" while initiating Jmeter?

I faced with the same error, when i downloaded the Jmeter Source, and it got fixed once i downloaded Jmeter Binary. Please watch this video.

Is the practice of returning a C++ reference variable evil?

return reference is usually used in operator overloading in C++ for large Object, because returning a value need copy operation.(in perator overloading, we usually don't use pointer as return value)

But return reference may cause memory allocation problem. Because a reference to the result will be passed out of the function as a reference to the return value, the return value cannot be an automatic variable.

if you want use returning refernce, you may use a buffer of static object. for example

const max_tmp=5; 
Obj& get_tmp()
{
 static int buf=0;
 static Obj Buf[max_tmp];
  if(buf==max_tmp) buf=0;
  return Buf[buf++];
}
Obj& operator+(const Obj& o1, const Obj& o1)
{
 Obj& res=get_tmp();
 // +operation
  return res;
 }

in this way, you could use returning reference safely.

But you could always use pointer instead of reference for returning value in functiong.

Split text with '\r\n'

Following code gives intended results.

string text="some interesting text\nsome text that should be in the same line\r\nsome 
text should be in another line"
var results = text.Split(new[] {"\n","\r\n"}, StringSplitOptions.None);

iPhone is not available. Please reconnect the device

Follow these steps:

  1. Check your iOS Version from (Settings ? General ? About ? Software Version) and get the device support file from the link below:

    https://github.com/iGhibli/iOS-DeviceSupport/tree/master/DeviceSupport

  2. Next, unzip the files and place them at the following location:

    Applications ? Xcode ? right click ? Show Package Contents ? Contents ? Developer ? Platforms ? iPhoneOS.platform ? DeviceSupport

  3. Restart Xcode

Can I get "&&" or "-and" to work in PowerShell?

&& and || were on the list of things to implement (still are) but did not pop up as the next most useful thing to add. The reason is that we have -AND and -OR. If you think it is important, please file a suggestion on Connect and we'll consider it for V3.

Named parameters in JDBC

JDBC does not support named parameters. Unless you are bound to using plain JDBC (which causes pain, let me tell you that) I would suggest to use Springs Excellent JDBCTemplate which can be used without the whole IoC Container.

NamedParameterJDBCTemplate supports named parameters, you can use them like that:

 NamedParameterJdbcTemplate jdbcTemplate = new NamedParameterJdbcTemplate(dataSource);

 MapSqlParameterSource paramSource = new MapSqlParameterSource();
 paramSource.addValue("name", name);
 paramSource.addValue("city", city);
 jdbcTemplate.queryForRowSet("SELECT * FROM customers WHERE name = :name AND city = :city", paramSource);

Opening A Specific File With A Batch File?

If the file that you want to open is in the same folder as your batch(.bat) file then you can simply try:

start filename.filetype

example: start image.png

How do I change the android actionbar title and icon

You can also do as follow :

override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main2)
        setSupportActionBar(toolbar)
        setTitle("Activity 2")
    }

Fit Image in ImageButton in Android

Try to use android:scaleType="fitXY" in i-Imagebutton xml

Oracle Error ORA-06512

The variable pCv is of type VARCHAR2 so when you concat the insert you aren't putting it inside single quotes:

 EXECUTE IMMEDIATE  'INSERT INTO M'||pNum||'GR (CV, SUP, IDM'||pNum||') VALUES('''||pCv||''', '||pSup||', '||pIdM||')';

Additionally the error ORA-06512 raise when you are trying to insert a value too large in a column. Check the definiton of the table M_pNum_GR and the parameters that you are sending. Just for clarify if you try to insert the value 100 on a NUMERIC(2) field the error will raise.

Android Button Onclick

It would be helpful to know what code you are trying to execute when the button is pressed. You've got the onClick property set in your xml file to a method called setLogin. For clarity, I'd delete this line android:onClick="setLogin" and call the method directly from inside your onClick() method.

Also you can't just set the display to a new XML, you need to start a new activity with an Intent, a method something like this would be appropriate

 private void setLogin() {

 Intent i = new Intent(currentActivity.this, newActivity.class);
 startActivty(i);

 }

Then set the new Activity to have the new layout.

what is the unsigned datatype?

According to C17 6.7.2 §2:

Each list of type specifiers shall be one of the following multisets (delimited by commas, when there is more than one multiset per item); the type specifiers may occur in any order, possibly intermixed with the other declaration specifiers

— void
— char
— signed char
— unsigned char
— short, signed short, short int, or signed short int
— unsigned short, or unsigned short int
— int, signed, or signed int
— unsigned, or unsigned int
— long, signed long, long int, or signed long int
— unsigned long, or unsigned long int
— long long, signed long long, long long int, or signed long long int
— unsigned long long, or unsigned long long int
— float
— double
— long double
— _Bool
— float _Complex
— double _Complex
— long double _Complex
— atomic type specifier
— struct or union specifier
— enum specifier
— typedef name

So in case of unsigned int we can either write unsigned or unsigned int, or if we are feeling crazy, int unsigned. The latter since the standard is stupid enough to allow "...may occur in any order, possibly intermixed". This is a known flaw of the language.

Proper C code uses unsigned int.

Table scroll with HTML and CSS

Adds a fading gradient to an overflowing HTML table element to better indicate there is more content to be scrolled.

  • Table with fixed header
  • Overflow scroll gradient
  • Custom scrollbar

See the live example below:

_x000D_
_x000D_
$("#scrolltable").html("<table id='cell'><tbody></tbody></table>");_x000D_
$("#cell").append("<thead><tr><th><div>First col</div></th><th><div>Second col</div></th></tr></thead>");_x000D_
_x000D_
for (var i = 0; i < 40; i++) {_x000D_
  $("#scrolltable > table > tbody").append("<tr><td>" + "foo" + "</td><td>" + "bar" + "</td></tr>");_x000D_
}
_x000D_
/* Table with fixed header */_x000D_
_x000D_
table,_x000D_
thead {_x000D_
  width: 100%;_x000D_
  text-align: left;_x000D_
}_x000D_
_x000D_
#scrolltable {_x000D_
  margin-top: 50px;_x000D_
  height: 120px;_x000D_
  overflow: auto;_x000D_
  width: 200px;_x000D_
}_x000D_
_x000D_
#scrolltable table {_x000D_
  border-collapse: collapse;_x000D_
}_x000D_
_x000D_
#scrolltable tr:nth-child(even) {_x000D_
  background: #EEE;_x000D_
}_x000D_
_x000D_
#scrolltable th div {_x000D_
  position: absolute;_x000D_
  margin-top: -30px;_x000D_
}_x000D_
_x000D_
_x000D_
/* Custom scrollbar */_x000D_
_x000D_
::-webkit-scrollbar {_x000D_
  width: 8px;_x000D_
}_x000D_
_x000D_
::-webkit-scrollbar-track {_x000D_
  box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.3);_x000D_
  border-radius: 10px;_x000D_
}_x000D_
_x000D_
::-webkit-scrollbar-thumb {_x000D_
  border-radius: 10px;_x000D_
  box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.5);_x000D_
}_x000D_
_x000D_
_x000D_
/* Overflow scroll gradient */_x000D_
_x000D_
.overflow-scroll-gradient {_x000D_
  position: relative;_x000D_
}_x000D_
_x000D_
.overflow-scroll-gradient::after {_x000D_
  content: '';_x000D_
  position: absolute;_x000D_
  bottom: 0;_x000D_
  width: 240px;_x000D_
  height: 25px;_x000D_
  background: linear-gradient( rgba(255, 255, 255, 0.001), white);_x000D_
  pointer-events: none;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div class="overflow-scroll-gradient">_x000D_
  <div id="scrolltable">_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to pass List<String> in post method using Spring MVC?

You are using wrong JSON. In this case you should use JSON that looks like this:

["orange", "apple"]

If you have to accept JSON in that form :

{"fruits":["apple","orange"]}

You'll have to create wrapper object:

public class FruitWrapper{

    List<String> fruits;

    //getter
    //setter
}

and then your controller method should look like this:

@RequestMapping(value = "/saveFruits", method = RequestMethod.POST, 
    consumes = "application/json")
@ResponseBody
public ResultObject saveFruits(@RequestBody FruitWrapper fruits){
...
}

Java: how do I initialize an array size if it's unknown?

I think you need use List or classes based on that.

For instance,

ArrayList<Integer> integers = new ArrayList<Integer>();
int j;

do{
    integers.add(int.nextInt());
    j++;
}while( (integers.get(j-1) >= 1) || (integers.get(j-1) <= 100) );

You could read this article for getting more information about how to use that.

Get original URL referer with PHP?

As Johnathan Suggested, you would either want to save it in a cookie or a session.

The easier way would be to use a Session variable.

session_start();
if(!isset($_SESSION['org_referer']))
{
    $_SESSION['org_referer'] = $_SERVER['HTTP_REFERER'];
}

Put that at the top of the page, and you will always be able to access the first referer that the site visitor was directed by.

How do I get column datatype in Oracle with PL-SQL with low privileges?

To see the internal representation size in bytes you can use:

REGEXP_SUBSTR(DUMP(your_column_name), 'Len=(\d+)\:', 1, 1, 'c', 1 ) 

Javascript Debugging line by line using Google Chrome

Assuming you're running on a Windows machine...

  1. Hit the F12 key
  2. Select the Scripts, or Sources, tab in the developer tools
  3. Click the little folder icon in the top level
  4. Select your JavaScript file
  5. Add a breakpoint by clicking on the line number on the left (adds a little blue marker)
  6. Execute your JavaScript

Then during execution debugging you can do a handful of stepping motions...

  • F8 Continue: Will continue until the next breakpoint
  • F10 Step over: Steps over next function call (won't enter the library)
  • F11 Step into: Steps into the next function call (will enter the library)
  • Shift + F11 Step out: Steps out of the current function

Update

After reading your updated post; to debug your code I would recommend temporarily using the jQuery Development Source Code. Although this doesn't directly solve your problem, it will allow you to debug more easily. For what you're trying to achieve I believe you'll need to step-in to the library, so hopefully the production code should help you decipher what's happening.

How to concatenate string variables in Bash

I wanted to build a string from a list. Couldn't find an answer for that so I post it here. Here is what I did:

list=(1 2 3 4 5)
string=''

for elm in "${list[@]}"; do
    string="${string} ${elm}"
done

echo ${string}

and then I get the following output:

1 2 3 4 5

How can I use tabs for indentation in IntelliJ IDEA?

Another useful option in IDEA to switch off or keep checked if you really need that:

Preferences -> Code Style -> Detect and use existing file indents for editing

if your team is going to switch to tab formatting with existing code written with spaces, uncheck that

How to fix libeay32.dll was not found error

It is a library from SSL. You need to install openssl.

You might also meet missing readline() function in python. You have to install pyreadline Lib.

NSNotificationCenter addObserver in Swift

A nice way of doing this is to use the addObserver(forName:object:queue:using:) method rather than the addObserver(_:selector:name:object:) method that is often used from Objective-C code. The advantage of the first variant is that you don't have to use the @objc attribute on your method:

    func batteryLevelChanged(notification: Notification) {
        // do something useful with this information
    }

    let observer = NotificationCenter.default.addObserver(
        forName: NSNotification.Name.UIDeviceBatteryLevelDidChange,
        object: nil, queue: nil,
        using: batteryLevelChanged)

and you can even just use a closure instead of a method if you want:

    let observer = NotificationCenter.default.addObserver(
        forName: NSNotification.Name.UIDeviceBatteryLevelDidChange,
        object: nil, queue: nil) { _ in print("") }

You can use the returned value to stop listening for the notification later:

    NotificationCenter.default.removeObserver(observer)

There used to be another advantage in using this method, which was that it doesn't require you to use selector strings which couldn't be statically checked by the compiler and so were fragile to breaking if the method is renamed, but Swift 2.2 and later include #selector expressions that fix that problem.

Prepend line to beginning of a file

Different Idea:

(1) You save the original file as a variable.

(2) You overwrite the original file with new information.

(3) You append the original file in the data below the new information.

Code:

with open(<filename>,'r') as contents:
      save = contents.read()
with open(<filename>,'w') as contents:
      contents.write(< New Information >)
with open(<filename>,'a') as contents:
      contents.write(save)

PHP function to generate v4 UUID

Inspired by broofa's answer here.

preg_replace_callback('/[xy]/', function ($matches)
{
  return dechex('x' == $matches[0] ? mt_rand(0, 15) : (mt_rand(0, 15) & 0x3 | 0x8));
}
, 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx');

Or if unable to use anonymous functions.

preg_replace_callback('/[xy]/', create_function(
  '$matches',
  'return dechex("x" == $matches[0] ? mt_rand(0, 15) : (mt_rand(0, 15) & 0x3 | 0x8));'
)
, 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx');

Which way is best for creating an object in JavaScript? Is `var` necessary before an object property?

There is no "best way" to create an object. Each way has benefits depending on your use case.

The constructor pattern (a function paired with the new operator to invoke it) provides the possibility of using prototypal inheritance, whereas the other ways don't. So if you want prototypal inheritance, then a constructor function is a fine way to go.

However, if you want prototypal inheritance, you may as well use Object.create, which makes the inheritance more obvious.

Creating an object literal (ex: var obj = {foo: "bar"};) works great if you happen to have all the properties you wish to set on hand at creation time.

For setting properties later, the NewObject.property1 syntax is generally preferable to NewObject['property1'] if you know the property name. But the latter is useful when you don't actually have the property's name ahead of time (ex: NewObject[someStringVar]).

Hope this helps!

How to get the size of a JavaScript object?

Here's a slightly more compact solution to the problem:

const typeSizes = {
  "undefined": () => 0,
  "boolean": () => 4,
  "number": () => 8,
  "string": item => 2 * item.length,
  "object": item => !item ? 0 : Object
    .keys(item)
    .reduce((total, key) => sizeOf(key) + sizeOf(item[key]) + total, 0)
};

const sizeOf = value => typeSizes[typeof value](value);

How can I remove item from querystring in asp.net using c#?

You're probably going to want use a Regular Expression to find the parameter you want to remove from the querystring, then remove it and redirect the browser to the same file with your new querystring.

Getting the index of a particular item in array

FindIndex Extension

static class ArrayExtensions
{
    public static int FindIndex<T>(this T[] array, Predicate<T> match)
    {
        return Array.FindIndex(array, match);
    }
}

Usage

int[] array = { 9,8,7,6,5 };

var index = array.FindIndex(i => i == 7);

Console.WriteLine(index); // Prints "2"

Here's a fiddle with it.


Bonus: IndexOf Extension

I wrote this first not reading the question properly...

static class ArrayExtensions
{
    public static int IndexOf<T>(this T[] array, T value)
    {
        return Array.IndexOf(array, value);
    }   
}

Usage

int[] array = { 9,8,7,6,5 };

var index = array.IndexOf(7);

Console.WriteLine(index); // Prints "2"

Here's a fiddle with it.

LINQ order by null column where order is ascending and nulls should be last

Try putting both columns in the same orderby.

orderby p.LowestPrice.HasValue descending, p.LowestPrice

Otherwise each orderby is a separate operation on the collection re-ordering it each time.

This should order the ones with a value first, "then" the order of the value.

How to get a list of sub-folders and their files, ordered by folder-names

create a vbs file and copy all code below. Change directory location to wherever you want.

Dim fso
Dim ObjOutFile

Set fso = CreateObject("Scripting.FileSystemObject")

Set ObjOutFile = fso.CreateTextFile("OutputFiles.csv")

ObjOutFile.WriteLine("Type,File Name,File Path")

GetFiles("YOUR LOCATION")

ObjOutFile.Close

WScript.Echo("Completed")

Function GetFiles(FolderName)
    On Error Resume Next

    Dim ObjFolder
    Dim ObjSubFolders
    Dim ObjSubFolder
    Dim ObjFiles
    Dim ObjFile

    Set ObjFolder = fso.GetFolder(FolderName)
    Set ObjFiles = ObjFolder.Files

    For Each ObjFile In ObjFiles
    ObjOutFile.WriteLine("File," & ObjFile.Name & "," & ObjFile.Path)
    Next

    Set ObjSubFolders = ObjFolder.SubFolders

    For Each ObjFolder In ObjSubFolders

        ObjOutFile.WriteLine("Folder," & ObjFolder.Name & "," & ObjFolder.Path)


        GetFiles(ObjFolder.Path)
    Next

End Function

Save the code as vbs and run it. you will get a list in that directory

Typescript: difference between String and string

In JavaScript strings can be either string primitive type or string objects. The following code shows the distinction:

var a: string = 'test'; // string literal
var b: String = new String('another test'); // string wrapper object

console.log(typeof a); // string
console.log(typeof b); // object

Your error:

Type 'String' is not assignable to type 'string'. 'string' is a primitive, but 'String' is a wrapper object. Prefer using 'string' when possible.

Is thrown by the TS compiler because you tried to assign the type string to a string object type (created via new keyword). The compiler is telling you that you should use the type string only for strings primitive types and you can't use this type to describe string object types.

How do CSS triangles work?

If you want to play around with border-size, width and height and see how those can create different shapes, try this:

_x000D_
_x000D_
const sizes = [32, 32, 32, 32];_x000D_
const triangle = document.getElementById('triangle');_x000D_
_x000D_
function update({ target }) {_x000D_
  let index = null;_x000D_
  _x000D_
  if (target) {_x000D_
    index = parseInt(target.id);_x000D_
_x000D_
    if (!isNaN(index)) {_x000D_
      sizes[index] = target.value;_x000D_
    }_x000D_
  }_x000D_
  _x000D_
  window.requestAnimationFrame(() => {_x000D_
    triangle.style.borderWidth = sizes.map(size => `${ size }px`).join(' ');_x000D_
    _x000D_
    if (isNaN(index)) {_x000D_
      triangle.style[target.id] = `${ target.value }px`;_x000D_
    }_x000D_
  });_x000D_
}_x000D_
_x000D_
document.querySelectorAll('input').forEach(input => {_x000D_
  input.oninput = update;_x000D_
});_x000D_
_x000D_
update({});
_x000D_
body {_x000D_
  margin: 0;_x000D_
  min-height: 100vh;_x000D_
  display: flex;_x000D_
  justify-content: center;_x000D_
  align-items: center;_x000D_
  overflow: hidden;_x000D_
}_x000D_
_x000D_
#triangle {_x000D_
    border-style: solid;_x000D_
    border-color: yellow magenta blue black;_x000D_
    background: cyan;_x000D_
    height: 0px;_x000D_
    width: 0px;_x000D_
}_x000D_
_x000D_
#controls {_x000D_
  position: fixed;_x000D_
  bottom: 0;_x000D_
  left: 0;_x000D_
  right: 0;_x000D_
  background: white;_x000D_
  display: flex;_x000D_
  box-shadow: 0 0 32px rgba(0, 0, 0, .125);_x000D_
}_x000D_
_x000D_
#controls > div {_x000D_
  position: relative;_x000D_
  width: 25%;_x000D_
  padding: 8px;_x000D_
  box-sizing: border-box;_x000D_
  display: flex;_x000D_
}_x000D_
_x000D_
input {_x000D_
  margin: 0;_x000D_
  width: 100%;_x000D_
  position: relative;_x000D_
}
_x000D_
<div id="triangle" style="border-width: 32px 32px 32px 32px;"></div>_x000D_
_x000D_
<div id="controls">_x000D_
  <div><input type="range" min="0" max="128" value="32" id="0" /></div>_x000D_
  <div><input type="range" min="0" max="128" value="32" id="1" /></div>_x000D_
  <div><input type="range" min="0" max="128" value="32" id="2" /></div>_x000D_
  <div><input type="range" min="0" max="128" value="32" id="3" /></div>_x000D_
  <div><input type="range" min="0" max="128" value="0" id="width" /></div>_x000D_
  <div><input type="range" min="0" max="128" value="0" id="height" /></div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to install latest version of Node using Brew

Try to use "n" the Node extremely simple package manager.

> npm install -g n

Once you have "n" installed. You can pull the latest node by doing the following:

> n latest

I've used it successfully on Ubuntu 16.0x and MacOS 10.12 (Sierra)

Reference: https://github.com/tj/n

Work on a remote project with Eclipse via SSH

This answer currently only applies to using two Linux computers [or maybe works on Mac too?--untested on Mac] (syncing from one to the other) because I wrote this synchronization script in bash. It is simply a wrapper around git, however, so feel free to take it and convert it into a cross-platform Python solution or something if you wish


This doesn't directly answer the OP's question, but it is so close I guarantee it will answer many other peoples' question who land on this page (mine included, actually, as I came here first before writing my own solution), so I'm posting it here anyway.

I want to:

  1. develop code using a powerful IDE like Eclipse on a light-weight Linux computer, then
  2. build that code via ssh on a different, more powerful Linux computer (from the command-line, NOT from inside Eclipse)

Let's call the first computer where I write the code "PC1" (Personal Computer 1), and the 2nd computer where I build the code "PC2". I need a tool to easily synchronize from PC1 to PC2. I tried rsync, but it was insanely slow for large repos and took tons of bandwidth and data.

So, how do I do it? What workflow should I use? If you have this question too, here's the workflow that I decided upon. I wrote a bash script to automate the process by using git to automatically push changes from PC1 to PC2 via a remote repository, such as github. So far it works very well and I'm very pleased with it. It is far far far faster than rsync, more trustworthy in my opinion because each PC maintains a functional git repo, and uses far less bandwidth to do the whole sync, so it's easily doable over a cell phone hot spot without using tons of your data.

Setup:

  1. Install the script on PC1 (this solution assumes ~/bin is in your $PATH):

    git clone https://github.com/ElectricRCAircraftGuy/eRCaGuy_dotfiles.git
    cd eRCaGuy_dotfiles/useful_scripts
    mkdir -p ~/bin
    ln -s "${PWD}/sync_git_repo_from_pc1_to_pc2.sh" ~/bin/sync_git_repo_from_pc1_to_pc2
    cd ..
    cp -i .sync_git_repo ~/.sync_git_repo
    
  2. Now edit the "~/.sync_git_repo" file you just copied above, and update its parameters to fit your case. Here are the parameters it contains:

    # The git repo root directory on PC2 where you are syncing your files TO; this dir must *already exist* 
    # and you must have *already `git clone`d* a copy of your git repo into it!
    # - Do NOT use variables such as `$HOME`. Be explicit instead. This is because the variable expansion will 
    #   happen on the local machine when what we need is the variable expansion from the remote machine. Being 
    #   explicit instead just avoids this problem.
    PC2_GIT_REPO_TARGET_DIR="/home/gabriel/dev/eRCaGuy_dotfiles" # explicitly type this out; don't use variables
    
    PC2_SSH_USERNAME="my_username" # explicitly type this out; don't use variables
    PC2_SSH_HOST="my_hostname"     # explicitly type this out; don't use variables
    
  3. Git clone your repo you want to sync on both PC1 and PC2.

  4. Ensure your ssh keys are all set up to be able to push and pull to the remote repo from both PC1 and PC2. Here's some helpful links:
    1. https://help.github.com/en/github/authenticating-to-github/connecting-to-github-with-ssh
    2. https://help.github.com/en/github/authenticating-to-github/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent
  5. Ensure your ssh keys are all set up to ssh from PC1 to PC2.
  6. Now cd into any directory within the git repo on PC1, and run:

    sync_git_repo_from_pc1_to_pc2
    
  7. That's it! About 30 seconds later everything will be magically synced from PC1 to PC2, and it will be printing output the whole time to tell you what it's doing and where it's doing it on your disk and on which computer. It's safe too, because it doesn't overwrite or delete anything that is uncommitted. It backs it up first instead! Read more below for how that works.

Here's the process this script uses (ie: what it's actually doing)

  1. From PC1: It checks to see if any uncommitted changes are on PC1. If so, it commits them to a temporary commit on the current branch. It then force pushes them to a remote SYNC branch. Then it uncommits its temporary commit it just did on the local branch, then it puts the local git repo back to exactly how it was by staging any files that were previously staged at the time you called the script. Next, it rsyncs a copy of the script over to PC2, and does an ssh call to tell PC2 to run the script with a special option to just do PC2 stuff.
  2. Here's what PC2 does: it cds into the repo, and checks to see if any local uncommitted changes exist. If so, it creates a new backup branch forked off of the current branch (sample name: my_branch_SYNC_BAK_20200220-0028hrs-15sec <-- notice that's YYYYMMDD-HHMMhrs--SSsec), and commits any uncommitted changes to that branch with a commit message such as DO BACKUP OF ALL UNCOMMITTED CHANGES ON PC2 (TARGET PC/BUILD MACHINE). Now, it checks out the SYNC branch, pulling it from the remote repository if it is not already on the local machine. Then, it fetches the latest changes on the remote repository, and does a hard reset to force the local SYNC repository to match the remote SYNC repository. You might call this a "hard pull". It is safe, however, because we already backed up any uncommitted changes we had locally on PC2, so nothing is lost!
  3. That's it! You now have produced a perfect copy from PC1 to PC2 without even having to ensure clean working directories, as the script handled all of the automatic committing and stuff for you! It is fast and works very well on huge repositories. Now you have an easy mechanism to use any IDE of your choice on one machine while building or testing on another machine, easily, over a wifi hot spot from your cell phone if needed, even if the repository is dozens of gigabytes and you are time and resource-constrained.

Resources:

  1. The whole project: https://github.com/ElectricRCAircraftGuy/eRCaGuy_dotfiles
    1. See tons more links and references in the source code itself within this project.
  2. How to do a "hard pull", as I call it: How do I force "git pull" to overwrite local files?

Related:

  1. git repository sync between computers, when moving around?

Center text in table cell

How about simply (Please note, come up with a better name for the class name this is simply an example):

.centerText{
   text-align: center;
}


<div>
   <table style="width:100%">
   <tbody>
   <tr>
      <td class="centerText">Cell 1</td>
      <td>Cell 2</td>
    </tr>
    <tr>
      <td class="centerText">Cell 3</td>
      <td>Cell 4</td>
    </tr>
    </tbody>
    </table>
</div>

Example here

You can place the css in a separate file, which is recommended. In my example, I created a file called styles.css and placed my css rules in it. Then include it in the html document in the <head> section as follows:

<head>
    <link href="styles.css" rel="stylesheet" type="text/css">
</head>

The alternative, not creating a seperate css file, not recommended at all... Create <style> block in your <head> in the html document. Then just place your rules there.

<head>
 <style type="text/css">
   .centerText{
       text-align: center;
    }
 </style>
</head>

iPhone Debugging: How to resolve 'failed to get the task for process'?

It might be that you have an expired development profile on your phone.

My development provisioning profile expired several days ago and I had to renew it. I installed the new profile on my phone and came up with the same error message when I tried to run my app. When I looked at the profile settings on my phone I noticed the expired profile and removed it. That cleared the error for me.

How to avoid java.util.ConcurrentModificationException when iterating through and removing elements from an ArrayList

"Should I clone the list first?"

That will be the easiest solution, remove from the clone, and copy the clone back after removal.

An example from my rummikub game:

SuppressWarnings("unchecked")
public void removeStones() {
  ArrayList<Stone> clone = (ArrayList<Stone>) stones.clone();
  // remove the stones moved to the table
  for (Stone stone : stones) {
      if (stone.isOnTable()) {
         clone.remove(stone);
      }
  }
  stones = (ArrayList<Stone>) clone.clone();
  sortStones();
}

Appending a vector to a vector

If you would like to add vector to itself both popular solutions will fail:

std::vector<std::string> v, orig;

orig.push_back("first");
orig.push_back("second");

// BAD:
v = orig;
v.insert(v.end(), v.begin(), v.end());
// Now v contains: { "first", "second", "", "" }

// BAD:
v = orig;
std::copy(v.begin(), v.end(), std::back_inserter(v));
// std::bad_alloc exception is generated

// GOOD, but I can't guarantee it will work with any STL:
v = orig;
v.reserve(v.size()*2);
v.insert(v.end(), v.begin(), v.end());
// Now v contains: { "first", "second", "first", "second" }

// GOOD, but I can't guarantee it will work with any STL:
v = orig;
v.reserve(v.size()*2);
std::copy(v.begin(), v.end(), std::back_inserter(v));
// Now v contains: { "first", "second", "first", "second" }

// GOOD (best):
v = orig;
v.insert(v.end(), orig.begin(), orig.end()); // note: we use different vectors here
// Now v contains: { "first", "second", "first", "second" }

Pandas split DataFrame by column value

Using "groupby" and list comprehension:

Storing all the split dataframe in list variable and accessing each of the seprated dataframe by their index.

DF = pd.DataFrame({'chr':["chr3","chr3","chr7","chr6","chr1"],'pos':[10,20,30,40,50],})
ans = [pd.DataFrame(y) for x, y in DF.groupby('chr', as_index=False)]

accessing the separated DF like this:

ans[0]
ans[1]
ans[len(ans)-1] # this is the last separated DF

accessing the column value of the separated DF like this:

ansI_chr=ans[i].chr 

Stylesheet not updating

Most probably the file is just being cached by the server. You could either disable cache (but remember to enable it when the site goes live), or modify href of your link tag, so the server will not load it from cache.

If your page is created dynamically by some language like php, you could add some variable at the end of the href value, like:

    <link rel="stylesheet" type="text/css" href="css/yourStyles.css?<?php echo time(); ?>" />

That will add the current timestamp on the end of a file path, so it will always be unique and never loaded from cache.

If your page is static, you have to manage those variables yourself, so use something like:

    <link rel="stylesheet" type="text/css" href="css/yourStyles.css?version=1" />

after doing some changes in the file content, change version=1 to version=2 and so on.

If you wish to disable the cache from caching css files, refer to your server type documentation (it's done differently on apache, IIS, nginx etc.) or ask/search for a question on https://serverfault.com/

Assuming IIS - adding the key under with the right settings in the root or the relevant folder does the trick.

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <caching enabled="false" enableKernelCache="false" /> <!-- This one -->
    </system.webServer>
</configuration>

That said sometimes one still has to recycle the Application Pool to "bump" the CSS. Therefore: Disabling IIS caching alone is not a 100% guaranteed solution.

For the browser: There are some notes on fine-grain controlling the local cache on FF over on SuperUser for the interested.

How do I resolve this "ORA-01109: database not open" error?

As the error states - the database is not open - it was previously shut down, and someone left it in the middle of the startup process. They may either be intentional, or unintentional (i.e., it was supposed to be open, but failed to do so).

Assuming that's nothing wrong with the database itself, you could open it with a simple statement:(Since the question is asked specifically in the context of SQLPlus, kindly remember to put a statement terminator(Semicolon) at the end mandatorily, otherwise, it will result in an error.)

ALTER DATABASE OPEN;

What does bundle exec rake mean?

I have not used bundle exec much, but am setting it up now.

I have had instances where the wrong rake was used and much time wasted tracking down the problem. This helps you avoid that.

Here's how to set up RVM so you can use bundle exec by default within a specific project directory:

https://thoughtbot.com/blog/use-bundlers-binstubs

Difference between single and double quotes in Bash

The accepted answer is great. I am making a table that helps in quick comprehension of the topic. The explanation involves a simple variable a as well as an indexed array arr.

If we set

a=apple      # a simple variable
arr=(apple)  # an indexed array with a single element

and then echo the expression in the second column, we would get the result / behavior shown in the third column. The fourth column explains the behavior.

# Expression Result Comments
1 "$a" apple variables are expanded inside ""
2 '$a' $a variables are not expanded inside ''
3 "'$a'" 'apple' '' has no special meaning inside ""
4 '"$a"' "$a" "" is treated literally inside ''
5 '\'' invalid can not escape a ' within ''; use "'" or $'\'' (ANSI-C quoting)
6 "red$arocks" red $arocks does not expand $a; use ${a}rocks to preserve $a
7 "redapple$" redapple$ $ followed by no variable name evaluates to $
8 '\"' \" \ has no special meaning inside ''
9 "\'" \' \' is interpreted inside "" but has no significance for '
10 "\"" " \" is interpreted inside ""
11 "*" * glob does not work inside "" or ''
12 "\t\n" \t\n \t and \n have no special meaning inside "" or ''; use ANSI-C quoting
13 "`echo hi`" hi `` and $() are evaluated inside "" (backquotes are retained in actual output)
14 '`echo hi`' echo hi `` and $() are not evaluated inside '' (backquotes are retained in actual output)
15 '${arr[0]}' ${arr[0]} array access not possible inside ''
16 "${arr[0]}" apple array access works inside ""
17 $'$a\'' $a' single quotes can be escaped inside ANSI-C quoting
18 "$'\t'" $'\t' ANSI-C quoting is not interpreted inside ""
19 '!cmd' !cmd history expansion character '!' is ignored inside ''
20 "!cmd" cmd args expands to the most recent command matching "cmd"
21 $'!cmd' !cmd history expansion character '!' is ignored inside ANSI-C quotes

See also:

REST API Best practice: How to accept list of parameter values as input

I will side with nategood's answer as it is complete and it seemed to have please your needs. Though, I would like to add a comment on identifying multiple (1 or more) resource that way:

http://our.api.com/Product/101404,7267261

In doing so, you:

Complexify the clients by forcing them to interpret your response as an array, which to me is counter intuitive if I make the following request: http://our.api.com/Product/101404

Create redundant APIs with one API for getting all products and the one above for getting 1 or many. Since you shouldn't show more than 1 page of details to a user for the sake of UX, I believe having more than 1 ID would be useless and purely used for filtering the products.

It might not be that problematic, but you will either have to handle this yourself server side by returning a single entity (by verifying if your response contains one or more) or let clients manage it.

Example

I want to order a book from Amazing. I know exactly which book it is and I see it in the listing when navigating for Horror books:

  1. 10 000 amazing lines, 0 amazing test
  2. The return of the amazing monster
  3. Let's duplicate amazing code
  4. The amazing beginning of the end

After selecting the second book, I am redirected to a page detailing the book part of a list:

--------------------------------------------
Book #1
--------------------------------------------
    Title: The return of the amazing monster
    Summary:
    Pages:
    Publisher:
--------------------------------------------

Or in a page giving me the full details of that book only?

---------------------------------
The return of the amazing monster
---------------------------------
Summary:
Pages:
Publisher:
---------------------------------

My Opinion

I would suggest using the ID in the path variable when unicity is guarantied when getting this resource's details. For example, the APIs below suggest multiple ways to get the details for a specific resource (assuming a product has a unique ID and a spec for that product has a unique name and you can navigate top down):

/products/{id}
/products/{id}/specs/{name}

The moment you need more than 1 resource, I would suggest filtering from a larger collection. For the same example:

/products?ids=

Of course, this is my opinion as it is not imposed.

laravel the requested url was not found on this server

This looks like you have to enable .htaccess by adding this to your vhost:

<Directory /var/www/html/public/>
    Options Indexes FollowSymLinks
    AllowOverride All
    Require all granted
</Directory>

If that doesn't work, make sure you have mod_rewrite enabled.

Don't forget to restart apache after making the changes! (service apache2 restart)

Select value from list of tuples where condition

If you have named tuples you can do this:

results = [t.age for t in mylist if t.person_id == 10]

Otherwise use indexes:

results = [t[1] for t in mylist if t[0] == 10]

Or use tuple unpacking as per Nate's answer. Note that you don't have to give a meaningful name to every item you unpack. You can do (person_id, age, _, _, _, _) to unpack a six item tuple.

how to bold words within a paragraph in HTML/CSS?

I know this question is old but I ran across it and I know other people might have the same problem. All these answers are okay but do not give proper detail or actual TRUE advice.

When wanting to style a specific section of a paragraph use the span tag.

<p><span style="font-weight:900">Andy Warhol</span> (August 6, 1928 - February 22, 1987) 

was an American artist who was a leading figure in the visual art movement known as pop 

art.</p>

Andy Warhol (August 6, 1928 - February 22, 1987) was an American artist who was a leading figure in the visual art movement known as pop art.

As the code shows, the span tag styles on the specified words: "Andy Warhol". You can further style a word using any CSS font styling codes.

{font-weight; font-size; text-decoration; font-family; margin; color}, etc. 

Any of these and more can be used to style a word, group of words, or even specified paragraphs without having to add a class to the CSS Style Sheet Doc. I hope this helps someone!

How to find whether a ResultSet is empty or not in Java?

Definitely this gives good solution,

ResultSet rs = stmt.execute("SQL QUERY");
// With the above statement you will not have a null ResultSet 'rs'.
// In case, if any exception occurs then next line of code won't execute.
// So, no problem if I won't check rs as null.

if (rs.next()) {
    do {
      // Logic to retrieve the data from the resultset.
      // eg: rs.getString("abc");
    } while(rs.next());
} else {
    // No data
}

python NameError: name 'file' is not defined

It seems that your project is written in Python < 3. This is because the file() builtin function is removed in Python 3. Try using Python 2to3 tool or edit the erroneous file yourself.

EDIT: BTW, the project page clearly mentions that

Gunicorn requires Python 2.x >= 2.5. Python 3.x support is planned.

Adding an assets folder in Android Studio

You can click on the Project window, press Alt-Insert, and select Folder->Assets Folder. Android Studio will add it automatically to the correct location.

You are most likely looking at your Project with the new(ish) "Android View". Note that this is a view and not the actual folder structure on disk (which hasn't changed since the introduction of Gradle as the new build tool). You can switch to the old "Project View" by clicking on the word "Android" at the top of the Project window and selecting "Project".

Save a list to a .txt file

Try this, if it helps you

values = ['1', '2', '3']

with open("file.txt", "w") as output:
    output.write(str(values))

Add button to navigationbar programmatically

Try this.It work for me. Add button to navigation bar programmatically, Also we set image to navigation bar button,

Below is Code:-

  UIBarButtonItem *Savebtn=[[UIBarButtonItem alloc]initWithImage:
  [[UIImage imageNamed:@"bt_save.png"]imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal] 
  style:UIBarButtonItemStylePlain target:self action:@selector(SaveButtonClicked)];
  self.navigationItem.rightBarButtonItem=Savebtn;

  -(void)SaveButtonClicked
  {
    // Add save button code.
  }

Error:Execution failed for task ':app:transformClassesWithDexForDebug'

I had this problem when I delegated my compilation task to the Google Compute Engine via SSH. The nature of this issue is a memory error, as indicated by the crash log; specifically it is thrown when Java runs out of virtual memory to work with during the build.

Important: When gradle crashes due to this memory error, the gradle daemons remain running long after your compilation task has failed. Any re-attempt to build using gradle again will allocate a new gradle daemon. You must ensure that you properly dispose of any crashed instances using gradlew --stop.

The hs_error_pid crash logs indicates the following workarounds:

# There is insufficient memory for the Java Runtime Environment to continue.
# Possible reasons:
#   The system is out of physical RAM or swap space
#   In 32 bit mode, the process size limit was hit
# Possible solutions:
#   Reduce memory load on the system
#   Increase physical memory or swap space
#   Check if swap backing store is full
#   Use 64 bit Java on a 64 bit OS
#   Decrease Java heap size (-Xmx/-Xms)
#   Decrease number of Java threads
#   Decrease Java thread stack sizes (-Xss)
#   Set larger code cache with -XX:ReservedCodeCacheSize=

I found that after increasing the runtime resources of the virtual machine, this issue was resolved.

Jquery to open Bootstrap v3 modal of remote url

e.relatedTarget.data('load-url'); won't work
use dataset.loadUrl

$('#myModal').on('show.bs.modal', function (e) {
    var loadurl = e.relatedTarget.dataset.loadUrl;
    $(this).find('.modal-body').load(loadurl);
});

Strip off URL parameter with PHP

@MarcB mentioned that it is dirty to use regex to remove an url parameter. And yes it is, because it's not as easy as it looks:

$urls = array(
  'example.com/?foo=bar',
  'example.com/?bar=foo&foo=bar',
  'example.com/?foo=bar&bar=foo',
);

echo 'Original' . PHP_EOL;
foreach ($urls as $url) {
  echo $url . PHP_EOL;
}

echo PHP_EOL . '@AaronHathaway' . PHP_EOL;
foreach ($urls as $url) {
  echo preg_replace('#&?foo=[^&]*#', null, $url) . PHP_EOL;
}

echo PHP_EOL . '@SergeS' . PHP_EOL;
foreach ($urls as $url) {
  echo preg_replace( "/&{2,}/", "&", preg_replace( "/foo=[^&]+/", "", $url)) . PHP_EOL;
}

echo PHP_EOL . '@Justin' . PHP_EOL;
foreach ($urls as $url) {
  echo preg_replace('/([?&])foo=[^&]+(&|$)/', '$1', $url) . PHP_EOL;
}

echo PHP_EOL . '@kraftb' . PHP_EOL;
foreach ($urls as $url) {
  echo preg_replace('/(&|\?)foo=[^&]*&/', '$1', preg_replace('/(&|\?)foo=[^&]*$/', '', $url)) . PHP_EOL;
}

echo PHP_EOL . 'My version' . PHP_EOL;
foreach ($urls as $url) {
  echo str_replace('/&', '/?', preg_replace('#[&?]foo=[^&]*#', null, $url)) . PHP_EOL;
}

returns:

Original
example.com/?foo=bar
example.com/?bar=foo&foo=bar
example.com/?foo=bar&bar=foo

@AaronHathaway
example.com/?
example.com/?bar=foo
example.com/?&bar=foo

@SergeS
example.com/?
example.com/?bar=foo&
example.com/?&bar=foo

@Justin
example.com/?
example.com/?bar=foo&
example.com/?bar=foo

@kraftb
example.com/
example.com/?bar=foo
example.com/?bar=foo

My version
example.com/
example.com/?bar=foo
example.com/?bar=foo

As you can see only @kraftb posted a correct answer using regex and my version is a little bit smaller.

How can I change my Cygwin home folder after installation?

Change your HOME environment variable.

on XP, its right-click My Computer >> Properties >> Advanced >> Environment Variables >> User Variables for >> [select variable HOME] >> edit

Excel 2007 - Compare 2 columns, find matching values

=VLOOKUP(lookup_value,table_array,col_index_num,range_lookup) will solve this issue.

This will search for a value in the first column to the left and return the value in the same row from a specific column.

Page loaded over HTTPS but requested an insecure XMLHttpRequest endpoint

this is easy,
if you use .htaccess , check http: for https: ,
if you use codeigniter, check config : url_base -> you url http change for https.....
I solved my problem.

Python Math - TypeError: 'NoneType' object is not subscriptable

lista = list.sort(lista)

This should be

lista.sort()

The .sort() method is in-place, and returns None. If you want something not in-place, which returns a value, you could use

sorted_list = sorted(lista)

Aside #1: please don't call your lists list. That clobbers the builtin list type.

Aside #2: I'm not sure what this line is meant to do:

print str("value 1a")+str(" + ")+str("value 2")+str(" = ")+str("value 3a ")+str("value 4")+str("\n")

is it simply

print "value 1a + value 2 = value 3a value 4"

? In other words, I don't know why you're calling str on things which are already str.

Aside #3: sometimes you use print("something") (Python 3 syntax) and sometimes you use print "something" (Python 2). The latter would give you a SyntaxError in py3, so you must be running 2.*, in which case you probably don't want to get in the habit or you'll wind up printing tuples, with extra parentheses. I admit that it'll work well enough here, because if there's only one element in the parentheses it's not interpreted as a tuple, but it looks strange to the pythonic eye..


The exception TypeError: 'NoneType' object is not subscriptable happens because the value of lista is actually None. You can reproduce TypeError that you get in your code if you try this at the Python command line:

None[0]

The reason that lista gets set to None is because the return value of list.sort() is None... it does not return a sorted copy of the original list. Instead, as the documentation points out, the list gets sorted in-place instead of a copy being made (this is for efficiency reasons).

If you do not want to alter the original version you can use

other_list = sorted(lista)

Updating the value of data attribute using jQuery

$('.toggle img').each(function(index) { 
    if($(this).attr('data-id') == '4')
    {
        $(this).attr('data-block', 'something');
        $(this).attr('src', 'something.jpg');
    }
});

or

$('.toggle img[data-id="4"]').attr('data-block', 'something');
$('.toggle img[data-id="4"]').attr('src', 'something.jpg');

Create an empty list in python with certain size

(This was written based on the original version of the question.)

I want to create a empty list (or whatever is the best way) can hold 10 elements.

All lists can hold as many elements as you like, subject only to the limit of available memory. The only "size" of a list that matters is the number of elements currently in it.

but when I run it, the result is []

print display s1 is not valid syntax; based on your description of what you're seeing, I assume you meant display(s1) and then print s1. For that to run, you must have previously defined a global s1 to pass into the function.

Calling display does not modify the list you pass in, as written. Your code says "s1 is a name for whatever thing was passed in to the function; ok, now the first thing we'll do is forget about that thing completely, and let s1 start referring instead to a newly created list. Now we'll modify that list". This has no effect on the value you passed in.

There is no reason to pass in a value here. (There is no real reason to create a function, either, but that's beside the point.) You want to "create" something, so that is the output of your function. No information is required to create the thing you describe, so don't pass any information in. To get information out, return it.

That would give you something like:

def display():
    s1 = list();
    for i in range(0, 9):
        s1[i] = i
    return s1

The next problem you will note is that your list will actually have only 9 elements, because the end point is skipped by the range function. (As side notes, [] works just as well as list(), the semicolon is unnecessary, s1 is a poor name for the variable, and only one parameter is needed for range if you're starting from 0.) So then you end up with

def create_list():
    result = list()
    for i in range(10):
        result[i] = i
    return result

However, this is still missing the mark; range is not some magical keyword that's part of the language the way for and def are, but instead it's a function. And guess what that function returns? That's right - a list of those integers. So the entire function collapses to

def create_list():
    return range(10)

and now you see why we don't need to write a function ourselves at all; range is already the function we're looking for. Although, again, there is no need or reason to "pre-size" the list.

How are zlib, gzip and zip related? What do they have in common and how are they different?

The most important difference is that gzip is only capable to compress a single file while zip compresses multiple files one by one and archives them into one single file afterwards. Thus, gzip comes along with tar most of the time (there are other possibilities, though). This comes along with some (dis)advantages.

If you have a big archive and you only need one single file out of it, you have to decompress the whole gzip file to get to that file. This is not required if you have a zip file.

On the other hand, if you compress 10 similiar or even identical files, the zip archive will be much bigger because each file is compressed individually, whereas in gzip in combination with tar a single file is compressed which is much more effective if the files are similiar (equal).

Advantages of std::for_each over for loop

Aside from readability and performance, one aspect commonly overlooked is consistency. There are many ways to implement a for (or while) loop over iterators, from:

for (C::iterator iter = c.begin(); iter != c.end(); iter++) {
    do_something(*iter);
}

to:

C::iterator iter = c.begin();
C::iterator end = c.end();
while (iter != end) {
    do_something(*iter);
    ++iter;
}

with many examples in between at varying levels of efficiency and bug potential.

Using for_each, however, enforces consistency by abstracting away the loop:

for_each(c.begin(), c.end(), do_something);

The only thing you have to worry about now is: do you implement the loop body as function, a functor, or a lambda using Boost or C++0x features? Personally, I'd rather worry about that than how to implement or read a random for/while loop.

Calling a class function inside of __init__

If I'm not wrong, both functions are part of your class, you should use it like this:

class MyClass():
    def __init__(self, filename):
        self.filename = filename 

        self.stat1 = None
        self.stat2 = None
        self.stat3 = None
        self.stat4 = None
        self.stat5 = None
        self.parse_file()

    def parse_file(self):
        #do some parsing
        self.stat1 = result_from_parse1
        self.stat2 = result_from_parse2
        self.stat3 = result_from_parse3
        self.stat4 = result_from_parse4
        self.stat5 = result_from_parse5

replace your line:

parse_file() 

with:

self.parse_file()

How to listen for a WebView finishing loading a URL?

Just to show progress bar, "onPageStarted" and "onPageFinished" methods are enough; but if you want to have an "is_loading" flag (along with page redirects, ...), this methods may executed with non-sequencing, like "onPageStarted > onPageStarted > onPageFinished > onPageFinished" queue.

But with my short test (test it yourself.), "onProgressChanged" method values queue is "0-100 > 0-100 > 0-100 > ..."

private boolean is_loading = false;

webView.setWebChromeClient(new MyWebChromeClient(context));

private final class MyWebChromeClient extends WebChromeClient{
    @Override
    public void onProgressChanged(WebView view, int newProgress) {
        if (newProgress == 0){
            is_loading = true;
        } else if (newProgress == 100){
            is_loading = false;
        }
        super.onProgressChanged(view, newProgress);
    }
}

Also set "is_loading = false" on activity close, if it is a static variable because activity can be finished before page finish.

Ignoring directories in Git repositories on Windows

You can create the ".gitignore" file with the contents:

*
!.gitignore

It works for me.

Laravel 5 – Remove Public from URL

Firstly you can use this steps

For Laravel 5:

1. Rename server.php in your Laravel root folder to index.php

2. Copy the .htaccess file from /public directory to your Laravel root folder.

source: https://stackoverflow.com/a/28735930

after you follow these steps then you need to change all css and script path, but this will be tiring.

Solution Proposal :simply you can make minor change the helpers::asset function.

For this:

  1. open vendor\laravel\framework\src\Illuminate\Foundation\helpers.php

  2. goto line 130

  3. write "public/".$path instead of $path,

    function asset($path, $secure = null){
       return app('url')->asset("public/".$path, $secure);
    }
    

Grant execute permission for a user on all stored procedures in database?

Create a role add this role to users, and then you can grant execute to all the routines in one shot to this role.

CREATE ROLE <abc>
GRANT EXECUTE TO <abc>

EDIT
This works in SQL Server 2005, I'm not sure about backward compatibility of this feature, I'm sure anything later than 2005 should be fine.

SELECT query with CASE condition and SUM()

I don't think you need a case statement. You just need to update your where clause and make sure you have correct parentheses to group the clauses.

SELECT Sum(CAMount) as PaymentAmount 
from TableOrderPayment 
where (CStatus = 'Active' AND CPaymentType = 'Cash') 
OR (CStatus = 'Active' and CPaymentType = 'Check' and CDate<=SYSDATETIME())

The answers posted before mine assume that CDate<=SYSDATETIME() is also appropriate for Cash payment type as well. I think I split mine out so it only looks for that clause for check payments.

How to use "Share image using" sharing Intent to share images in android?

if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(),
            Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
        Log.d(TAG, "Permission granted");
    } else {
        ActivityCompat.requestPermissions(getActivity(),
                new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                100);
    }

    fab.setOnClickListener(v -> {
        Bitmap b = BitmapFactory.decodeResource(getResources(), R.drawable.refer_pic);
        Intent share = new Intent(Intent.ACTION_SEND);
        share.setType("image/*");
        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        b.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
        String path = MediaStore.Images.Media.insertImage(requireActivity().getContentResolver(),
                b, "Title", null);
        Uri imageUri = Uri.parse(path);
        share.putExtra(Intent.EXTRA_STREAM, imageUri);
        share.putExtra(Intent.EXTRA_TEXT, "Here is text");
        startActivity(Intent.createChooser(share, "Share via"));
    });

How to know if a DateTime is between a DateRange in C#

Following on from Sergey's answer, I think this more generic version is more in line with Fowler's Range idea, and resolves some of the issues with that answer such as being able to have the Includes methods within a generic class by constraining T as IComparable<T>. It's also immutable like what you would expect with types that extend the functionality of other value types like DateTime.

public struct Range<T> where T : IComparable<T>
{
    public Range(T start, T end)
    {
        Start = start;
        End = end;
    }

    public T Start { get; }

    public T End { get; }

    public bool Includes(T value) => Start.CompareTo(value) <= 0 && End.CompareTo(value) >= 0;

    public bool Includes(Range<T> range) => Start.CompareTo(range.Start) <= 0 && End.CompareTo(range.End) >= 0;
}

IPhone/IPad: How to get screen width programmatically?

Here is a Swift way to get screen sizes, this also takes current interface orientation into account:

var screenWidth: CGFloat {
    if UIInterfaceOrientationIsPortrait(screenOrientation) {
        return UIScreen.mainScreen().bounds.size.width
    } else {
        return UIScreen.mainScreen().bounds.size.height
    }
}
var screenHeight: CGFloat {
    if UIInterfaceOrientationIsPortrait(screenOrientation) {
        return UIScreen.mainScreen().bounds.size.height
    } else {
        return UIScreen.mainScreen().bounds.size.width
    }
}
var screenOrientation: UIInterfaceOrientation {
    return UIApplication.sharedApplication().statusBarOrientation
}

These are included as a standard function in:

https://github.com/goktugyil/EZSwiftExtensions

How can I remove a specific item from an array?

You can use splice to remove objects or values from an array.

Let's consider an array of length 5, with values 10,20,30,40,50, and I want to remove the value 30 from it.

_x000D_
_x000D_
var array = [10,20,30,40,50];_x000D_
if (array.indexOf(30) > -1) {_x000D_
   array.splice(array.indexOf(30), 1);_x000D_
}_x000D_
console.log(array); // [10,20,40,50]
_x000D_
_x000D_
_x000D_

Convert an image to grayscale

To summarize a few items here: There are some pixel-by-pixel options that, while being simple just aren't fast.

@Luis' comment linking to: (archived) https://web.archive.org/web/20110827032809/http://www.switchonthecode.com/tutorials/csharp-tutorial-convert-a-color-image-to-grayscale is superb.

He runs through three different options and includes timings for each.

How to send an email with Python?

I'd like to help you with sending emails by advising the yagmail package (I'm the maintainer, sorry for the advertising, but I feel it can really help!).

The whole code for you would be:

import yagmail
yag = yagmail.SMTP(FROM, 'pass')
yag.send(TO, SUBJECT, TEXT)

Note that I provide defaults for all arguments, for example if you want to send to yourself, you can omit TO, if you don't want a subject, you can omit it also.

Furthermore, the goal is also to make it really easy to attach html code or images (and other files).

Where you put contents you can do something like:

contents = ['Body text, and here is an embedded image:', 'http://somedomain/image.png',
            'You can also find an audio file attached.', '/local/path/song.mp3']

Wow, how easy it is to send attachments! This would take like 20 lines without yagmail ;)

Also, if you set it up once, you'll never have to enter the password again (and have it safely stored). In your case you can do something like:

import yagmail
yagmail.SMTP().send(contents = contents)

which is much more concise!

I'd invite you to have a look at the github or install it directly with pip install yagmail.

Making Enter key on an HTML form submit instead of activating button

$("form#submit input").on('keypress',function(event) {
  event.preventDefault();
  if (event.which === 13) {
    $('button.submit').trigger('click');
  }
});

How to choose an AES encryption mode (CBC ECB CTR OCB CFB)?

  1. Anything but ECB.
  2. If using CTR, it is imperative that you use a different IV for each message, otherwise you end up with the attacker being able to take two ciphertexts and deriving a combined unencrypted plaintext. The reason is that CTR mode essentially turns a block cipher into a stream cipher, and the first rule of stream ciphers is to never use the same Key+IV twice.
  3. There really isn't much difference in how difficult the modes are to implement. Some modes only require the block cipher to operate in the encrypting direction. However, most block ciphers, including AES, don't take much more code to implement decryption.
  4. For all cipher modes, it is important to use different IVs for each message if your messages could be identical in the first several bytes, and you don't want an attacker knowing this.

Execute external program

import java.io.*;

public class Code {
  public static void main(String[] args) throws Exception {
    ProcessBuilder builder = new ProcessBuilder("ls", "-ltr");
    Process process = builder.start();

    StringBuilder out = new StringBuilder();
    try (BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()))) {
        String line = null;
      while ((line = reader.readLine()) != null) {
        out.append(line);
        out.append("\n");
      }
      System.out.println(out);
    }
  }
}

Try online

What's the correct way to convert bytes to a hex string in Python 3?

it can been used the format specifier %x02 that format and output a hex value. For example:

>>> foo = b"tC\xfc}\x05i\x8d\x86\x05\xa5\xb4\xd3]Vd\x9cZ\x92~'6"
>>> res = ""
>>> for b in foo:
...     res += "%02x" % b
... 
>>> print(res)
7443fc7d05698d8605a5b4d35d56649c5a927e2736

How to make child element higher z-index than parent?

Use non-static position along with greater z-index in child element:

.parent {
    position: absolute
    z-index: 100;
}

.child {
    position: relative;
    z-index: 101;
}

Why would $_FILES be empty when uploading files to PHP?

Another possible culprit is apache redirects. In my case I had apache's httpd.conf set up to redirect certain pages on our site to http versions, and other pages to https versions of the page, if they weren't already. The page on which I had a form with a file input was one of the pages configured to force ssl, but the page designated as the action of the form was configured to be http. So the page would submit the upload to the ssl version of the action page, but apache was redirecting it to the http version of the page and the post data, including the uploaded file was lost.

The SELECT permission was denied on the object 'Users', database 'XXX', schema 'dbo'

  1. Open SQL Management Studio
  2. Expand your database
  3. Expand the "Security" Folder
  4. Expand "Users"
  5. Right click the user (the one that's trying to perform the query) and select Properties.
  6. Select page Membership.
  7. Make sure you uncheck

    db_denydatareader

    db_denydatawriter

enter image description here

This should go without saying, but only grant the permissions to what the user needs. An easy lazy fix is to check db_owner like I have, but this is not the best security practice.

How to add a "confirm delete" option in ASP.Net Gridview?

I like this way of adding a confirmation prompt before deleting a record from a gridview. This is the CommandField definition nested within a GridView web control in the aspx page. There's nothing fancy here--just a straightforward Commandfield.

_x000D_
_x000D_
<asp:CommandField ShowEditButton="true" UpdateText="Save" ShowDeleteButton="True">_x000D_
  <ControlStyle CssClass="modMarketAdjust" />_x000D_
</asp:CommandField>
_x000D_
_x000D_
_x000D_

Then, all I had to do was add some code to the RowDeleting event of the GridView control. This event fires before the row is actually deleted, which allows you to get the user's confirmation, and to cancel the event if he doesn't want to cancel after all. Here is the code that I put in the RowDeleting event handler:

Private Sub grdMarketAdjustment_RowDeleting(sender As Object, e As GridViewDeleteEventArgs) Handles grdMarketAdjustment.RowDeleting
  Dim confirmed As Integer = MsgBox("Are you sure that you want to delete this market adjustment?", MsgBoxStyle.YesNo + MsgBoxStyle.MsgBoxSetForeground, "Confirm Delete")
  If Not confirmed = MsgBoxResult.Yes Then
    e.Cancel = True 'Cancel the delete.
  End If
End Sub

And that seems to work fine.

How to determine if a type implements an interface with C# reflection

IsAssignableFrom is now moved to TypeInfo:

typeof(ISMSRequest).GetTypeInfo().IsAssignableFrom(typeof(T).GetTypeInfo());

WP -- Get posts by category?

Check here : http://codex.wordpress.org/Template_Tags/get_posts

Note: The category parameter needs to be the ID of the category, and not the category name.

Excel VBA - How to Redim a 2D array?

Here ya go.

Public Function ReDimPreserve(ByRef Arr, ByVal idx1 As Integer, ByVal idx2 As Integer)

    Dim newArr()
    Dim x As Integer
    Dim y As Integer

    ReDim newArr(idx1, idx2)

    For x = 0 To UBound(Arr, 1)
        For y = 0 To UBound(Arr, 2)
            newArr(x, y) = Arr(x, y)
        Next
    Next

    Arr = newArr

End Function

How to work with string fields in a C struct?

You could just use an even simpler typedef:

typedef char *string;

Then, your malloc would look like a usual malloc:

string s = malloc(maxStringLength);

Apply CSS Style to child elements

.test * {padding: 40px 100px 40px 50px;}

Can a Byte[] Array be written to a file in C#?

You can use a BinaryWriter object.

protected bool SaveData(string FileName, byte[] Data)
{
    BinaryWriter Writer = null;
    string Name = @"C:\temp\yourfile.name";

    try
    {
        // Create a new stream to write to the file
        Writer = new BinaryWriter(File.OpenWrite(Name));

        // Writer raw data                
        Writer.Write(Data);
        Writer.Flush();
        Writer.Close();
    }
    catch 
    {
        //...
        return false;
    }

    return true;
}

Edit: Oops, forgot the finally part... lets say it is left as an exercise for the reader ;-)

List comprehension vs map

I find list comprehensions are generally more expressive of what I'm trying to do than map - they both get it done, but the former saves the mental load of trying to understand what could be a complex lambda expression.

There's also an interview out there somewhere (I can't find it offhand) where Guido lists lambdas and the functional functions as the thing he most regrets about accepting into Python, so you could make the argument that they're un-Pythonic by virtue of that.

mysql query: SELECT DISTINCT column1, GROUP BY column2

Try the following:

SELECT DISTINCT(ip), name, COUNT(name) nameCnt, 
time, price, SUM(price) priceSum
FROM tablename 
WHERE time >= $yesterday AND time <$today 
GROUP BY ip, name

Chrome disable SSL checking for sites?

In my case I was developing an ASP.Net MVC5 web app and the certificate errors on my local dev machine (IISExpress certificate) started becoming a practical concern once I started working with service workers. Chrome simply wouldn't register my service worker because of the certificate error.

I did, however, notice that during my automated Selenium browser tests, Chrome seem to just "ignore" all these kinds of problems (e.g. the warning page about an insecure site), so I asked myself the question: How is Selenium starting Chrome for running its tests, and might it also solve the service worker problem?

Using Process Explorer on Windows, I was able to find out the command-line arguments with which Selenium is starting Chrome:

"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --disable-background-networking --disable-client-side-phishing-detection --disable-default-apps --disable-hang-monitor --disable-popup-blocking --disable-prompt-on-repost --disable-sync --disable-web-resources --enable-automation --enable-logging --force-fieldtrials=SiteIsolationExtensions/Control --ignore-certificate-errors --log-level=0 --metrics-recording-only --no-first-run --password-store=basic --remote-debugging-port=12207 --safebrowsing-disable-auto-update --test-type=webdriver --use-mock-keychain --user-data-dir="C:\Users\Sam\AppData\Local\Temp\some-non-existent-directory" data:,

There are a bunch of parameters here that I didn't end up doing necessity-testing for, but if I run Chrome this way, my service worker registers and works as expected.

The only one that does seem to make a difference is the --user-data-dir parameter, which to make things work can be set to a non-existent directory (things won't work if you don't provide the parameter).

Hope that helps someone else with a similar problem. I'm using Chrome 60.0.3112.90.

Find nginx version?

My guess is it's not in your path.
in bash, try:
echo $PATH
and
sudo which nginx
And see if the folder containing nginx is also in your $PATH variable.
If not, either add the folder to your path environment variable, or create an alias (and put it in your .bashrc) ooor your could create a link i guess.
or sudo nginx -v if you just want that...

Suppress output of a function

It isn't clear why you want to do this without sink, but you can wrap any commands in the invisible() function and it will suppress the output. For instance:

1:10 # prints output
invisible(1:10) # hides it

Otherwise, you can always combine things into one line with a semicolon and parentheses:

{ sink("/dev/null"); ....; sink(); }

how to make log4j to write to the console as well

This works well for console in debug mode

log4j.appender.console=org.apache.log4j.ConsoleAppender
log4j.appender.console.Threshold=DEBUG
log4j.appender.console.Target=System.out
log4j.appender.console.layout=org.apache.log4j.PatternLayout
log4j.appender.console.layout.conversionPattern=%d{yyyy-MM-dd HH:mm:ss,SSS} %-5p - %m%n

Adding elements to an xml file in C#

I've used XDocument.Root.Add to add elements. Root returns XElement which has an Add function for additional XElements

What is the difference between ports 465 and 587?

I don't want to name names, but someone appears to be completely wrong. The referenced standards body stated the following: submissions 465 tcp Message Submission over TLS protocol [IESG] [IETF_Chair] 2017-12-12 [RFC8314]

If you are so inclined, you may wish to read the referenced RFC.

This seems to clearly imply that port 465 is the best way to force encrypted communication and be sure that it is in place. Port 587 offers no such guarantee.

CSS Box Shadow - Top and Bottom Only

essentially the shadow is the box shape just offset behind the actual box. in order to hide portions of the shadow, you need to create additional divs and set their z-index above the shadowed box so that the shadow is not visible.

If you'd like to have extremely specific control over your shadows, build them as images and created container divs with the right amount of padding and margins.. then use the png fix to make sure the shadows render properly in all browsers

How to store Emoji Character in MySQL Database

If you are inserting using PHP, and you have followed the various ALTER database and ALTER table options above, make sure your php connection's charset is utf8mb4.

Example of connection string:

$this->pdo = new PDO("mysql:host=$ip;port=$port;dbname=$db;charset=utf8mb4", etc etc

Notice the "charset" is utf8mb4, not just utf8!

Extracting the last n characters from a string in R

I used the following code to get the last character of a string.

    substr(output, nchar(stringOfInterest), nchar(stringOfInterest))

You can play with the nchar(stringOfInterest) to figure out how to get last few characters.

Creating a blocking Queue<T> in .NET?

I haven't fully explored the TPL but they might have something that fits your needs, or at the very least, some Reflector fodder to snag some inspiration from.

Hope that helps.

Get class labels from Keras functional model

To map predicted classes and filenames using ImageDataGenerator, I use:

# Data generator and prediction
test_datagen = ImageDataGenerator(rescale=1./255)
test_generator = test_datagen.flow_from_directory(
        inputpath,
        target_size=(150, 150),
        batch_size=20,
        class_mode='categorical',
        shuffle=False)
pred = model.predict_generator(test_generator, steps=len(test_generator), verbose=0)
# Get classes by max element in np (as a list)
classes = list(np.argmax(pred, axis=1))
# Get filenames (set shuffle=false in generator is important)
filenames = test_generator.filenames

I can loop over predicted classes and the associated filename using:

for f in zip(classes, filenames):
    ...

How to create a fixed-size array of objects

If what you want is a fixed size array, and initialize it with nil values, you can use an UnsafeMutableBufferPointer, allocate memory for 64 nodes with it, and then read/write from/to the memory by subscripting the pointer type instance. This also has the benefit of avoiding checking if the memory must be reallocated, which Array does. I would however be surprised if the compiler doesn't optimize that away for arrays that don't have any more calls to methods that may require resizing, other than at the creation site.

let count = 64
let sprites = UnsafeMutableBufferPointer<SKSpriteNode>.allocate(capacity: count)

for i in 0..<count {
    sprites[i] = ...
}

for sprite in sprites {
    print(sprite!)
}

sprites.deallocate()

This is however not very user friendly. So, let's make a wrapper!

class ConstantSizeArray<T>: ExpressibleByArrayLiteral {
    
    typealias ArrayLiteralElement = T
    
    private let memory: UnsafeMutableBufferPointer<T>
    
    public var count: Int {
        get {
            return memory.count
        }
    }
    
    private init(_ count: Int) {
        memory = UnsafeMutableBufferPointer.allocate(capacity: count)
    }
    
    public convenience init(count: Int, repeating value: T) {
        self.init(count)
        
        memory.initialize(repeating: value)
    }
    
    public required convenience init(arrayLiteral: ArrayLiteralElement...) {
        self.init(arrayLiteral.count)
        
        memory.initialize(from: arrayLiteral)
    }
    
    deinit {
        memory.deallocate()
    }
    
    public subscript(index: Int) -> T {
        set(value) {
            precondition((0...endIndex).contains(index))
            
            memory[index] = value;
        }
        get {
            precondition((0...endIndex).contains(index))
            
            return memory[index]
        }
    }
}

extension ConstantSizeArray: MutableCollection {
    public var startIndex: Int {
        return 0
    }
    
    public var endIndex: Int {
        return count - 1
    }
    
    func index(after i: Int) -> Int {
        return i + 1;
    }
}

Now, this is a class, and not a structure, so there's some reference counting overhead incurred here. You can change it to a struct instead, but because Swift doesn't provide you with an ability to use copy initializers and deinit on structures, you'll need a deallocation method (func release() { memory.deallocate() }), and all copied instances of the structure will reference the same memory.

Now, this class may just be good enough. Its use is simple:

let sprites = ConstantSizeArray<SKSpriteNode?>(count: 64, repeating: nil)

for i in 0..<sprites.count {
    sprite[i] = ...
}

for sprite in sprites {
    print(sprite!)
}

For more protocols to implement conformance to, see the Array documentation (scroll to Relationships).

How to run Gradle from the command line on Mac bash

./gradlew

Your directory with gradlew is not included in the PATH, so you must specify path to the gradlew. . means "current directory".

Switching to a TabBar tab view programmatically?

Note that the tabs are indexed starting from 0. So the following code snippet works

tabBarController = [[UITabBarController alloc] init];
.
.
.
tabBarController.selectedViewController = [tabBarController.viewControllers objectAtIndex:4];

goes to the fifth tab in the bar.

Modulo operation with negative numbers

The other answers have explained in C99 or later, division of integers involving negative operands always truncate towards zero.

Note that, in C89, whether the result round upward or downward is implementation-defined. Because (a/b) * b + a%b equals a in all standards, the result of % involving negative operands is also implementation-defined in C89.

How to enable remote access of mysql in centos?

Bind-address XXX.XX.XX.XXX in /etc/my.cnf

comment line:

skip-networking

or

skip-external-locking

after edit hit service mysqld restart

login into mysql and hit this query:

GRANT ALL PRIVILEGES ON dbname.* TO 'username'@'%' IDENTIFIED BY 'password';

FLUSH PRIVILEGES;
quit;

add firewall rule:

iptables -I INPUT -i eth0 -p tcp --destination-port 3306 -j ACCEPT

Difference between os.getenv and os.environ.get

In Python 2.7 with iPython:

>>> import os
>>> os.getenv??
Signature: os.getenv(key, default=None)
Source:
def getenv(key, default=None):
    """Get an environment variable, return None if it doesn't exist.
    The optional second argument can specify an alternate default."""
    return environ.get(key, default)
File:      ~/venv/lib/python2.7/os.py
Type:      function

So we can conclude os.getenv is just a simple wrapper around os.environ.get.

How to check if an item is selected from an HTML drop down list?

Select select = new Select(_element);
List<WebElement> selectedOptions = select.getAllSelectedOptions();

if(selectedOptions.size() > 0){
    return true;
}else{
    return false;
}

How to get access token from FB.login method in javascript SDK

_x000D_
_x000D_
window.fbAsyncInit = function () {_x000D_
    FB.init({_x000D_
        appId: 'Your-appId',_x000D_
        cookie: false,  // enable cookies to allow the server to access _x000D_
        // the session_x000D_
        xfbml: true,  // parse social plugins on this page_x000D_
        version: 'v2.0' // use version 2.0_x000D_
    });_x000D_
};_x000D_
_x000D_
// Load the SDK asynchronously_x000D_
(function (d, s, id) {_x000D_
    var js, fjs = d.getElementsByTagName(s)[0];_x000D_
    if (d.getElementById(id)) return;_x000D_
    js = d.createElement(s); js.id = id;_x000D_
    js.src = "//connect.facebook.net/en_US/sdk.js";_x000D_
    fjs.parentNode.insertBefore(js, fjs);_x000D_
}(document, 'script', 'facebook-jssdk'));_x000D_
_x000D_
   _x000D_
function fb_login() {_x000D_
    FB.login(function (response) {_x000D_
_x000D_
        if (response.authResponse) {_x000D_
            console.log('Welcome!  Fetching your information.... ');_x000D_
            //console.log(response); // dump complete info_x000D_
            access_token = response.authResponse.accessToken; //get access token_x000D_
            user_id = response.authResponse.userID; //get FB UID_x000D_
_x000D_
            FB.api('/me', function (response) {_x000D_
                var email = response.email;_x000D_
                var name = response.name;_x000D_
                window.location = 'http://localhost:12962/Account/FacebookLogin/' + email + '/' + name;_x000D_
                // used in my mvc3 controller for //AuthenticationFormsAuthentication.SetAuthCookie(email, true);          _x000D_
            });_x000D_
_x000D_
        } else {_x000D_
            //user hit cancel button_x000D_
            console.log('User cancelled login or did not fully authorize.');_x000D_
_x000D_
        }_x000D_
    }, {_x000D_
        scope: 'email'_x000D_
    });_x000D_
}
_x000D_
<!-- custom image -->_x000D_
<a href="#" onclick="fb_login();"><img src="/Public/assets/images/facebook/facebook_connect_button.png" /></a>_x000D_
_x000D_
<!-- Facebook button -->_x000D_
<fb:login-button scope="public_profile,email" onlogin="fb_login();">_x000D_
                </fb:login-button>
_x000D_
_x000D_
_x000D_

What version of MongoDB is installed on Ubuntu

When you entered in mongo shell using "mongo" command , that time only you will notice

MongoDB shell version v3.4.0-rc2
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.4.0-rc2

also you can try command,in mongo shell , db.version()

JSF rendered multiple combined conditions

Assuming that "a" and "b" are bean properties

rendered="#{bean.a==12 and (bean.b==13 or bean.b==15)}"

You may look at JSF EL operators

Remove empty lines in a text file via grep

Simplest Answer -----------------------------------------

[root@node1 ~]# cat /etc/sudoers | grep -v -e ^# -e ^$
Defaults   !visiblepw
Defaults    always_set_home
Defaults    match_group_by_gid
Defaults    always_query_group_plugin
Defaults    env_reset
Defaults    env_keep =  "COLORS DISPLAY HOSTNAME HISTSIZE KDEDIR LS_COLORS"
Defaults    env_keep += "MAIL PS1 PS2 QTDIR USERNAME LANG LC_ADDRESS LC_CTYPE"
Defaults    env_keep += "LC_COLLATE LC_IDENTIFICATION LC_MEASUREMENT LC_MESSAGES"
Defaults    env_keep += "LC_MONETARY LC_NAME LC_NUMERIC LC_PAPER LC_TELEPHONE"
Defaults    env_keep += "LC_TIME LC_ALL LANGUAGE LINGUAS _XKB_CHARSET XAUTHORITY"
Defaults    secure_path = /sbin:/bin:/usr/sbin:/usr/bin
root    ALL=(ALL)       ALL
%wheel  ALL=(ALL)       ALL
[root@node1 ~]#

What's the @ in front of a string in C#?

This is a verbatim string, and changes the escaping rules - the only character that is now escaped is ", escaped to "". This is especially useful for file paths and regex:

var path = @"c:\some\location";
var tsql = @"SELECT *
            FROM FOO
            WHERE Bar = 1";
var escaped = @"a "" b";

etc

Blocking device rotation on mobile web pages

_x000D_
_x000D_
#rotate-device {_x000D_
    width: 100%;_x000D_
    height: 100%;_x000D_
    position: fixed;_x000D_
    z-index: 9999;_x000D_
    top: 0;_x000D_
    left: 0;_x000D_
    background-color: #000;_x000D_
    background-image: url(/path to img/rotate.png);_x000D_
    background-size: 100px 100px;_x000D_
    background-position: center;_x000D_
    background-repeat: no-repeat;_x000D_
    display: none;_x000D_
}_x000D_
_x000D_
@media only screen and (max-device-width: 667px) and (min-device-width: 320px) and (orientation: landscape){_x000D_
 #rotate-device {_x000D_
  display: block;_x000D_
 }_x000D_
}
_x000D_
<div id="rotate-device"></div>
_x000D_
_x000D_
_x000D_

Detect when input has a 'readonly' attribute

Check the current value of your "readonly" attribute, if it's "false" (a string) or empty (undefined or "") then it's not readonly.

$('input').each(function() {
    var readonly = $(this).attr("readonly");
    if(readonly && readonly.toLowerCase()!=='false') { // this is readonly
        alert('this is a read only field');
    }
});

What's the console.log() of java?

console.log() in java is System.out.println(); to put text on the next line

And System.out.print(); puts text on the same line.

check if array is empty (vba excel)

Adding into this: it depends on what your array is defined as. Consider:

dim a() as integer
dim b() as string
dim c() as variant

'these doesn't work
if isempty(a) then msgbox "integer arrays can be empty"
if isempty(b) then msgbox "string arrays can be empty"

'this is because isempty can only be tested on classes which have an .empty property

'this do work
if isempty(c) then msgbox "variants can be empty"

So, what can we do? In VBA, we can see if we can trigger an error and somehow handle it, for example

dim a() as integer
dim bEmpty as boolean

bempty=false

on error resume next
bempty=not isnumeric(ubound(a))
on error goto 0

But this is really clumsy... A nicer solution is to declare a boolean variable (a public or module level is best). When the array is first initialised, then set this variable. Because it's a variable declared at the same time, if it loses it's value, then you know that you need to reinitialise your array. However, if it is initialised, then all you're doing is checking the value of a boolean, which is low cost. It depends on whether being low cost matters, and if you're going to be needing to check it often.

option explicit

'declared at module level
dim a() as integer
dim aInitialised as boolean

sub DoSomethingWithA()
if not aInitialised then InitialiseA
'you can now proceed confident that a() is intialised
end sub

sub InitialiseA()
'insert code to do whatever is required to initialise A
'e.g. 
redim a(10)
a(1)=123
'...
aInitialised=true
end sub

The last thing you can do is create a function; which in this case will need to be dependent on the clumsy on error method.

function isInitialised(byref a() as variant) as boolean
isInitialised=false
on error resume next
isinitialised=isnumeric(ubound(a))
end function

Change collations of all columns of all tables in SQL Server

Fixed length problem nvarchar (include max), included text and added NULL/NOT NULL.

USE [put your database name here];

begin tran

DECLARE @collate nvarchar(100);
DECLARE @table nvarchar(255);
DECLARE @column_name nvarchar(255);
DECLARE @column_id int;
DECLARE @data_type nvarchar(255);
DECLARE @max_length int;
DECLARE @max_length_str nvarchar(100);
DECLARE @is_nullable bit;
DECLARE @row_id int;
DECLARE @sql nvarchar(max);
DECLARE @sql_column nvarchar(max);

SET @collate = 'Latin1_General_CI_AS';

DECLARE local_table_cursor CURSOR FOR

SELECT [name]
FROM sysobjects
WHERE OBJECTPROPERTY(id, N'IsUserTable') = 1
ORDER BY [name]

OPEN local_table_cursor
FETCH NEXT FROM local_table_cursor
INTO @table

WHILE @@FETCH_STATUS = 0
BEGIN

    DECLARE local_change_cursor CURSOR FOR

    SELECT ROW_NUMBER() OVER (ORDER BY c.column_id) AS row_id
        , c.name column_name
        , t.Name data_type
        , col.CHARACTER_MAXIMUM_LENGTH
        , c.column_id
        , c.is_nullable
    FROM sys.columns c
    JOIN sys.types t ON c.system_type_id = t.system_type_id
    JOIN INFORMATION_SCHEMA.COLUMNS col on col.COLUMN_NAME = c.name and c.object_id = OBJECT_ID(col.TABLE_NAME)
    LEFT OUTER JOIN sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id
    LEFT OUTER JOIN sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id
    WHERE c.object_id = OBJECT_ID(@table) AND (t.Name LIKE '%char%' OR t.Name LIKE '%text%') 
    AND c.collation_name <> @collate
    ORDER BY c.column_id

    OPEN local_change_cursor
    FETCH NEXT FROM local_change_cursor
    INTO @row_id, @column_name, @data_type, @max_length, @column_id, @is_nullable

    WHILE @@FETCH_STATUS = 0
    BEGIN

        set @max_length_str = @max_length
        IF (@max_length = -1) SET @max_length_str = 'max'
        IF (@max_length > 4000) SET @max_length_str = '4000'

        BEGIN TRY
            SET @sql =
            CASE 
                WHEN @data_type like '%text%' 
                THEN 'ALTER TABLE ' + @table + ' ALTER COLUMN [' + @column_name + '] ' + @data_type + ' COLLATE ' + @collate + ' ' + CASE WHEN @is_nullable = 0 THEN 'NOT NULL' ELSE 'NULL' END
                ELSE 'ALTER TABLE ' + @table + ' ALTER COLUMN [' + @column_name + '] ' + @data_type + '(' + @max_length_str + ') COLLATE ' + @collate + ' ' + CASE WHEN @is_nullable = 0 THEN 'NOT NULL' ELSE 'NULL' END
            END
            --PRINT @sql
            EXEC sp_executesql @sql
        END TRY
        BEGIN CATCH
          PRINT 'ERROR (' + @table + '): Some index or constraint rely on the column ' + @column_name + '. No conversion possible.'
          --PRINT @sql
        END CATCH

        FETCH NEXT FROM local_change_cursor
        INTO @row_id, @column_name, @data_type, @max_length, @column_id, @is_nullable

    END

    CLOSE local_change_cursor
    DEALLOCATE local_change_cursor

    FETCH NEXT FROM local_table_cursor
    INTO @table

END

CLOSE local_table_cursor
DEALLOCATE local_table_cursor

commit tran

GO

Notice : in case when you just need to change some specific collation use condition like this :

WHERE c.object_id = OBJECT_ID(@table) AND (t.Name LIKE '%char%' OR t.Name LIKE '%text%') 
    AND c.collation_name = 'collation to change'

e.g. NOT the : AND c.collation_name <> @collate

In my case, I had correct / specified collation of some columns and didn't want to change them.

Why doesn't list have safe "get" method like dictionary?

Dictionaries are for look ups. It makes sense to ask if an entry exists or not. Lists are usually iterated. It isn't common to ask if L[10] exists but rather if the length of L is 11.

CSS: Control space between bullet and <li>

Here is another solution using css counter and pseudo elements. I find it more elegant as it doesn't require use of extra html markup nor css classes :

ol,
ul {
    list-style-position: inside;
}

li {
    list-style-type: none;
}

ol {
    counter-reset: ol; //reset the counter for every new ol
}

ul li:before {
        content: '\2022 \00a0 \00a0 \00a0'; //bullet unicode followed by 3 non breakable spaces
}

ol li:before {
        counter-increment: ol;
        content: counter(ol) '.\00a0 \00a0 \00a0'; //css counter followed by a dot and 3 non breakable spaces
}

I use non breakable spaces so that the spacing only affects the first line of my list elements (if the list element is more than one line long). You could use padding here instead.

Refreshing page on click of a button

<button onclick=location=URL>Refresh</button>

Small hack.

Are email addresses case sensitive?

Per @l3x, it depends.

There are clearly two sets of general situations where the correct answer can be different, along with a third which is not as general:

a) You are a user sending private mails:

Very few modern email systems implement case sensitivity, so you are probably fine to ignore case and choose whatever case you feel like using. There is no guarantee that all your mails will be delivered - but so few mails would be negatively affected that you should not worry about it.

b) You are developing mail software:

See RFC5321 2.4 excerpt at the bottom.

When you are developing mail software, you want to be RFC-compliant. You can make your own users' email addresses case insensitive if you want to (and you probably should). But in order to be RFC compliant, you MUST treat outside addresses as case sensitive.

c) Managing business-owned lists of email addresses as an employee:

It is possible that the same email recipient is added to a list more than once - but using different case. In this situation though the addresses are technically different, it might result in a recipient receiving duplicate emails. How you treat this situation is similar to situation a) in that you are probably fine to treat them as duplicates and to remove a duplicate entry. It is better to treat these as special cases however, by sending a "reminder" mail to both addresses to ask them if the case of the email address is accurate.

From a legal standpoint, if you remove a duplicate without acknowledgement/permission from both addresses, you can be held responsible for leaking private information/authentication to an unauthorised address simply because two actually-separate recipients have the same address with different cases.

Excerpt from RFC5321 2.4:

The local-part of a mailbox MUST BE treated as case sensitive. Therefore, SMTP implementations MUST take care to preserve the case of mailbox local-parts. In particular, for some hosts, the user "smith" is different from the user "Smith". However, exploiting the case sensitivity of mailbox local-parts impedes interoperability and is discouraged.

How to force composer to reinstall a library?

What I did:

  1. Deleted that particular library's folder
  2. composer update --prefer-source vendor/library-name

It fetches the library again along with it's git repo

How can I make Bootstrap columns all the same height?

@media (min-width: @screen-sm-min) {
    div.equal-height-sm {
        display: table;


        > div[class^='col-'] {
            display: table-cell;
            float: none;
            vertical-align: top;
        }
    }
}

<div class="equal-height-sm">
    <div class="col-xs-12 col-sm-7">Test<br/>Test<br/>Test</div>
    <div class="col-xs-12 col-sm-5">Test</div>
</div>

Example:

https://jsfiddle.net/b9chris/njcnex83/embedded/result/

Adapted from several answers here. The flexbox-based answers are the right way once IE8 and 9 are dead, and once Android 2.x is dead, but that is not true in 2015, and likely won't be in 2016. IE8 and 9 still make up 4-6% of usage depending on how you measure, and for many corporate users it's much worse. http://caniuse.com/#feat=flexbox

The display: table, display: table-cell trick is more backwards-compatible - and one great thing is the only serious compatibility issue is a Safari issue where it forces box-sizing: border-box, something already applied to your Bootstrap tags. http://caniuse.com/#feat=css-table

You can obviously add more classes that do similar things, like .equal-height-md. I tied these to divs for the small performance benefit in my constrained usage, but you could remove the tag to make it more generalized like the rest of Bootstrap.

Note that the jsfiddle here uses CSS, and so, things Less would otherwise provide are hard-coded in the linked example. For example @screen-sm-min has been replaced with what Less would insert - 768px.

Laravel Request getting current path with query string

$request->fullUrl() will also work if you are injecting Illumitate\Http\Request.

Can't pickle <type 'instancemethod'> when using multiprocessing Pool.map()

Update: as of the day of this writing, namedTuples are pickable (starting with python 2.7)

The issue here is the child processes aren't able to import the class of the object -in this case, the class P-, in the case of a multi-model project the Class P should be importable anywhere the child process get used

a quick workaround is to make it importable by affecting it to globals()

globals()["P"] = P

Tomcat view catalina.out log file

If you type in the command line

catalina

you will see some message about it, look for this:

CATALINA_BASE: /usr/local/Cellar/tomcat/9.0.27/libexec

cd /usr/local/Cellar/tomcat/9.0.27/libexec/logs
tail -f catalina.out

You will then see the live logs.

NOTE: My Tomcat installation was done via Homebrew

URL Encode a string in jQuery for an AJAX request

I'm using MVC3/EntityFramework as back-end, the front-end consumes all of my project controllers via jquery, posting directly (using $.post) doesnt requires the data encription, when you pass params directly other than URL hardcoded. I already tested several chars i even sent an URL(this one http://www.ihackforfun.eu/index.php?title=update-on-url-crazy&more=1&c=1&tb=1&pb=1) as a parameter and had no issue at all even though encodeURIComponent works great when you pass all data in within the URL (hardcoded)

Hardcoded URL i.e.>

 var encodedName = encodeURIComponent(name);
 var url = "ControllerName/ActionName/" + encodedName + "/" + keyword + "/" + description + "/" + linkUrl + "/" + includeMetrics + "/" + typeTask + "/" + project + "/" + userCreated + "/" + userModified + "/" + status + "/" + parent;; // + name + "/" + keyword + "/" + description + "/" + linkUrl + "/" + includeMetrics + "/" + typeTask + "/" + project + "/" + userCreated + "/" + userModified + "/" + status + "/" + parent;

Otherwise dont use encodeURIComponent and instead try passing params in within the ajax post method

 var url = "ControllerName/ActionName/";   
 $.post(url,
        { name: nameVal, fkKeyword: keyword, description: descriptionVal, linkUrl: linkUrlVal, includeMetrics: includeMetricsVal, FKTypeTask: typeTask, FKProject: project, FKUserCreated: userCreated, FKUserModified: userModified, FKStatus: status, FKParent: parent },
 function (data) {.......});

Difference between "read commited" and "repeatable read"

I think this picture can also be useful, it helps me as a reference when I want to quickly remember the differences between isolation levels (thanks to kudvenkat on youtube)

enter image description here

Python find elements in one list that are not in the other

From ser1 remove items present in ser2.

Input

ser1 = pd.Series([1, 2, 3, 4, 5]) ser2 = pd.Series([4, 5, 6, 7, 8])

Solution

ser1[~ser1.isin(ser2)]

Convert XLS to CSV on command line

You can do it with Alacon - command-line utility for Alasql database. It works with Node.js, so you need to install Node.js and then Alasql package.

To convert Excel file to CVS (ot TSV) you can enter:

> node alacon "SELECT * INTO CSV('mydata.csv', {headers:true}) FROM XLS('mydata.xls', {headers:true})"

By default Alasql converts data from "Sheet1", but you can change it with parameters:

{headers:false, sheetid: 'Sheet2', range: 'A1:C100'}

Alacon supports other type of conversions (CSV, TSV, TXT, XLSX, XLS) and SQL language constructions (see User Manual for examples).

How do I show/hide a UIBarButtonItem?

For Swift version, here is the code:

For UINavigationBar:

self.navigationItem.rightBarButtonItem = nil

self.navigationItem.leftBarButtonItem = nil

Difference between MongoDB and Mongoose

One more difference I found with respect to both is that it is fairly easy to connect to multiple databases with mongodb native driver while you have to use work arounds in mongoose which still have some drawbacks.

So if you wanna go for a multitenant application, go for mongodb native driver.

500.19 - Internal Server Error - The requested page cannot be accessed because the related configuration data for the page is invalid

**Enable** All Features under **Application Development Features** and Refresh the **IIS**

Goto Windows Features on or Off . Enable All Features under Application Development Features and Refresh the IIS. Its Working

How to get a Fragment to remove itself, i.e. its equivalent of finish()?

OnCreate:

//Add comment fragment
            container = FindViewById<FrameLayout>(Resource.Id.frmAttachPicture);
            mPictureFragment = new fmtAttachPicture();

            var trans = SupportFragmentManager.BeginTransaction();
            trans.Add(container.Id, mPictureFragment, "fmtPicture");
            trans.Show(mPictureFragment); trans.Commit();

This is how I hide the fragment in click event 1

//Close fragment
    var trans = SupportFragmentManager.BeginTransaction();
    trans.Hide(mPictureFragment);
    trans.AddToBackStack(null);
    trans.Commit();

Then Shows it back int event 2

var trans = SupportFragmentManager.BeginTransaction();
            trans.Show(mPictureFragment); trans.Commit();

How to downgrade the installed version of 'pip' on windows?

If downgrading from pip version 10 because of PyCharm manage.py or other python errors:

python -m pip install pip==9.0.1

ASP.Net which user account running Web Service on IIS 7?

Server 2008

Start Task Manager Find w3wp.exe process (description IIS Worker Process) Check User Name column to find who you're IIS process is running as.

In the IIS GUI you can configure your application pool to run as a specific user: Application Pool default Advanced Settings Identity

Here's the info from Microsoft on setting up Application Pool Identites:

http://learn.iis.net/page.aspx/624/application-pool-identities/

How to set a binding in Code?

In addition to the answer of Dyppl, I think it would be nice to place this inside the OnDataContextChanged event:

private void OnDataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
    // Unforunately we cannot bind from the viewmodel to the code behind so easily, the dependency property is not available in XAML. (for some reason).
    // To work around this, we create the binding once we get the viewmodel through the datacontext.
    var newViewModel = e.NewValue as MyViewModel;

    var executablePathBinding = new Binding
    {
        Source = newViewModel,
        Path = new PropertyPath(nameof(newViewModel.ExecutablePath))
    };

    BindingOperations.SetBinding(LayoutRoot, ExecutablePathProperty, executablePathBinding);
}

We have also had cases were we just saved the DataContext to a local property and used that to access viewmodel properties. The choice is of course yours, I like this approach because it is more consistent with the rest. You can also add some validation, like null checks. If you actually change your DataContext around, I think it would be nice to also call:

BindingOperations.ClearBinding(myText, TextBlock.TextProperty);

to clear the binding of the old viewmodel (e.oldValue in the event handler).

Specifying content of an iframe instead of the src attribute to a page

iframe now supports srcdoc which can be used to specify the HTML content of the page to show in the inline frame.

Gson: Directly convert String to JsonObject (no POJO)

com.google.gson.JsonParser#parse(java.lang.String) is now deprecated

so use com.google.gson.JsonParser#parseString, it works pretty well

Kotlin Example:

val mJsonObject = JsonParser.parseString(myStringJsonbject).asJsonObject

Java Example:

JsonObject mJsonObject = JsonParser.parseString(myStringJsonbject).getAsJsonObject();

Java generics - ArrayList initialization

A lot of this has to do with polymorphism. When you assign

X = new Y();

X can be much less 'specific' than Y, but not the other way around. X is just the handle you are accessing Y with, Y is the real instantiated thing,

You get an error here because Integer is a Number, but Number is not an Integer.

ArrayList<Integer> a = new ArrayList<Number>(); // compile-time error

As such, any method of X that you call must be valid for Y. Since X is more generally it probably shares some, but not all of Y's methods. Still, any arguments given must be valid for Y.

In your examples with add, an int (small i) is not a valid Object or Integer.

ArrayList<?> a = new ArrayList<?>();

This is no good because you can't actually instantiate an array list containing ?'s. You can declare one as such, and then damn near anything can follow in new ArrayList<Whatever>();

Finding the index of an item in a list

A problem will arise if the element is not in the list. This function handles the issue:

# if element is found it returns index of element else returns None

def find_element_in_list(element, list_element):
    try:
        index_element = list_element.index(element)
        return index_element
    except ValueError:
        return None

How to get info on sent PHP curl request

You can also use a proxy tool like Charles to capture the outgoing request headers, data, etc. by passing the proxy details through CURLOPT_PROXY to your curl_setopt_array method.

For example:

$proxy = '127.0.0.1:8888';
$opt = array (
    CURLOPT_URL => "http://www.example.com",
    CURLOPT_PROXY => $proxy,
    CURLOPT_POST => true,
    CURLOPT_VERBOSE => true,
    );

$ch = curl_init();
curl_setopt_array($ch, $opt);
curl_exec($ch);
curl_close($ch);

Remove useless zero digits from decimals in PHP

Strange, when I get a number out of database with a "float" type and if my number is ex. 10000 when I floatval it, it becomes 1.

$number = $ad['price_month']; // 1000 from the database with a float type
echo floatval($number);
Result : 1

I've tested all the solutions above but didn't work.

Raise an error manually in T-SQL to jump to BEGIN CATCH block

You could use THROW (available in SQL Server 2012+):

THROW 50000, 'Your custom error message', 1
THROW <error_number>, <message>, <state>

MSDN THROW (Transact-SQL)

Differences Between RAISERROR and THROW in Sql Server

Return in Scala

I don't program Scala, but I use another language with implicit returns (Ruby). You have code after your if (elem.isEmpty) block -- the last line of code is what's returned, which is why you're not getting what you're expecting.

EDIT: Here's a simpler way to write your function too. Just use the boolean value of isEmpty and count to return true or false automatically:

def balanceMain(elem: List[Char]): Boolean =
{
    elem.isEmpty && count == 0
}

Learning Regular Expressions

The most important part is the concepts. Once you understand how the building blocks work, differences in syntax amount to little more than mild dialects. A layer on top of your regular expression engine's syntax is the syntax of the programming language you're using. Languages such as Perl remove most of this complication, but you'll have to keep in mind other considerations if you're using regular expressions in a C program.

If you think of regular expressions as building blocks that you can mix and match as you please, it helps you learn how to write and debug your own patterns but also how to understand patterns written by others.

Start simple

Conceptually, the simplest regular expressions are literal characters. The pattern N matches the character 'N'.

Regular expressions next to each other match sequences. For example, the pattern Nick matches the sequence 'N' followed by 'i' followed by 'c' followed by 'k'.

If you've ever used grep on Unix—even if only to search for ordinary looking strings—you've already been using regular expressions! (The re in grep refers to regular expressions.)

Order from the menu

Adding just a little complexity, you can match either 'Nick' or 'nick' with the pattern [Nn]ick. The part in square brackets is a character class, which means it matches exactly one of the enclosed characters. You can also use ranges in character classes, so [a-c] matches either 'a' or 'b' or 'c'.

The pattern . is special: rather than matching a literal dot only, it matches any character. It's the same conceptually as the really big character class [-.?+%$A-Za-z0-9...].

Think of character classes as menus: pick just one.

Helpful shortcuts

Using . can save you lots of typing, and there are other shortcuts for common patterns. Say you want to match a digit: one way to write that is [0-9]. Digits are a frequent match target, so you could instead use the shortcut \d. Others are \s (whitespace) and \w (word characters: alphanumerics or underscore).

The uppercased variants are their complements, so \S matches any non-whitespace character, for example.

Once is not enough

From there, you can repeat parts of your pattern with quantifiers. For example, the pattern ab?c matches 'abc' or 'ac' because the ? quantifier makes the subpattern it modifies optional. Other quantifiers are

  • * (zero or more times)
  • + (one or more times)
  • {n} (exactly n times)
  • {n,} (at least n times)
  • {n,m} (at least n times but no more than m times)

Putting some of these blocks together, the pattern [Nn]*ick matches all of

  • ick
  • Nick
  • nick
  • Nnick
  • nNick
  • nnick
  • (and so on)

The first match demonstrates an important lesson: * always succeeds! Any pattern can match zero times.

A few other useful examples:

  • [0-9]+ (and its equivalent \d+) matches any non-negative integer
  • \d{4}-\d{2}-\d{2} matches dates formatted like 2019-01-01

Grouping

A quantifier modifies the pattern to its immediate left. You might expect 0abc+0 to match '0abc0', '0abcabc0', and so forth, but the pattern immediately to the left of the plus quantifier is c. This means 0abc+0 matches '0abc0', '0abcc0', '0abccc0', and so on.

To match one or more sequences of 'abc' with zeros on the ends, use 0(abc)+0. The parentheses denote a subpattern that can be quantified as a unit. It's also common for regular expression engines to save or "capture" the portion of the input text that matches a parenthesized group. Extracting bits this way is much more flexible and less error-prone than counting indices and substr.

Alternation

Earlier, we saw one way to match either 'Nick' or 'nick'. Another is with alternation as in Nick|nick. Remember that alternation includes everything to its left and everything to its right. Use grouping parentheses to limit the scope of |, e.g., (Nick|nick).

For another example, you could equivalently write [a-c] as a|b|c, but this is likely to be suboptimal because many implementations assume alternatives will have lengths greater than 1.

Escaping

Although some characters match themselves, others have special meanings. The pattern \d+ doesn't match backslash followed by lowercase D followed by a plus sign: to get that, we'd use \\d\+. A backslash removes the special meaning from the following character.

Greediness

Regular expression quantifiers are greedy. This means they match as much text as they possibly can while allowing the entire pattern to match successfully.

For example, say the input is

"Hello," she said, "How are you?"

You might expect ".+" to match only 'Hello,' and will then be surprised when you see that it matched from 'Hello' all the way through 'you?'.

To switch from greedy to what you might think of as cautious, add an extra ? to the quantifier. Now you understand how \((.+?)\), the example from your question works. It matches the sequence of a literal left-parenthesis, followed by one or more characters, and terminated by a right-parenthesis.

If your input is '(123) (456)', then the first capture will be '123'. Non-greedy quantifiers want to allow the rest of the pattern to start matching as soon as possible.

(As to your confusion, I don't know of any regular-expression dialect where ((.+?)) would do the same thing. I suspect something got lost in transmission somewhere along the way.)

Anchors

Use the special pattern ^ to match only at the beginning of your input and $ to match only at the end. Making "bookends" with your patterns where you say, "I know what's at the front and back, but give me everything between" is a useful technique.

Say you want to match comments of the form

-- This is a comment --

you'd write ^--\s+(.+)\s+--$.

Build your own

Regular expressions are recursive, so now that you understand these basic rules, you can combine them however you like.

Tools for writing and debugging regexes:

Books

Free resources

Footnote

†: The statement above that . matches any character is a simplification for pedagogical purposes that is not strictly true. Dot matches any character except newline, "\n", but in practice you rarely expect a pattern such as .+ to cross a newline boundary. Perl regexes have a /s switch and Java Pattern.DOTALL, for example, to make . match any character at all. For languages that don't have such a feature, you can use something like [\s\S] to match "any whitespace or any non-whitespace", in other words anything.

How can I process each letter of text using Javascript?

If you want to do a transformation on the text on a character level, and get the transformed text back at the end, you would do something like this:

var value = "alma";
var new_value = value.split("").map(function(x) { return x+"E" }).join("")

So the steps:

  • Split the string into an array (list) of characters
  • Map each character via a functor
  • Join the resulting array of chars together into the resulting string

Eclipse CDT: no rule to make target all

If the above solutions did not work for you so -

Could be that you did not install C++ compiler packages properly, flow this: (Instructions for Win7, 32bit/64bit)

  1. Make sure you install properly one or more of the supporting C++ compiler packages:

    (I installed MinGW (HowTo Install Videos can be found on YouTube))

    In case you choose to install MinGW packages:

    • Download MinGW installer from the Install Page above
    • Run MinGW installer and make sure to choose the following packages:

      - mingw-developer-toolkit
      - mingw32-base
      - mingw32-gcc-g++
      - msys-base

    • Add MinGW and MSYS bin paths to your PATH environment variable , if you didn't change the default installation folders you should add:

    C:\MinGW\msys\1.0\bin;C:\MinGW\bin;
    • Logoff and log back in for making sure Environment vars kicked in
  2. Create a new C++ project in eclipse:

    • New -> C++ Projects
    • Choose Project type: Executables -> Hello World C++ project
      (Now on the right, under Toolchains you shall see MinGW GCC)
    • Select MinGW GCC from the Toolchains list
    • Hit Finish
  3. In you Hello World Project you shall see + src folder, and + Includes (If so you are probably good to go).

  4. Build project
  5. Run it!

Entity Framework. Delete all rows in table

If you wish to clear your entire database.

Because of the foreign-key constraints it matters which sequence the tables are truncated. This is a way to bruteforce this sequence.

    public static void ClearDatabase<T>() where T : DbContext, new()
    {
        using (var context = new T())
        {
            var tableNames = context.Database.SqlQuery<string>("SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = 'BASE TABLE' AND TABLE_NAME NOT LIKE '%Migration%'").ToList();
            foreach (var tableName in tableNames)
            {
                foreach (var t in tableNames)
                {
                    try
                    {

                        if (context.Database.ExecuteSqlCommand(string.Format("TRUNCATE TABLE [{0}]", tableName)) == 1)
                            break;

                    }
                    catch (Exception ex)
                    {

                    }
                }
            }

            context.SaveChanges();
        }
    }

usage:

ClearDatabase<ApplicationDbContext>();

remember to reinstantiate your DbContext after this.

Best way to create unique token in Rails?

I think token should be handled just like password. As such, they should be encrypted in DB.

I'n doing something like this to generate a unique new token for a model:

key = ActiveSupport::KeyGenerator
                .new(Devise.secret_key)
                .generate_key("put some random or the name of the key")

loop do
  raw = SecureRandom.urlsafe_base64(nil, false)
  enc = OpenSSL::HMAC.hexdigest('SHA256', key, raw)

  break [raw, enc] unless Model.exist?(token: enc)
end

Calculate a Running Total in SQL Server

I believe a running total can be achieved using the simple INNER JOIN operation below.

SELECT
     ROW_NUMBER() OVER (ORDER BY SomeDate) AS OrderID
    ,rt.*
INTO
    #tmp
FROM
    (
        SELECT 45 AS ID, CAST('01-01-2009' AS DATETIME) AS SomeDate, 3 AS SomeValue
        UNION ALL
        SELECT 23, CAST('01-08-2009' AS DATETIME), 5
        UNION ALL
        SELECT 12, CAST('02-02-2009' AS DATETIME), 0
        UNION ALL
        SELECT 77, CAST('02-14-2009' AS DATETIME), 7
        UNION ALL
        SELECT 39, CAST('02-20-2009' AS DATETIME), 34
        UNION ALL
        SELECT 33, CAST('03-02-2009' AS DATETIME), 6
    ) rt

SELECT
     t1.ID
    ,t1.SomeDate
    ,t1.SomeValue
    ,SUM(t2.SomeValue) AS RunningTotal
FROM
    #tmp t1
    JOIN #tmp t2
        ON t2.OrderID <= t1.OrderID
GROUP BY
     t1.OrderID
    ,t1.ID
    ,t1.SomeDate
    ,t1.SomeValue
ORDER BY
    t1.OrderID

DROP TABLE #tmp

Remove characters from NSString?

You could use:

NSString *stringWithoutSpaces = [myString 
   stringByReplacingOccurrencesOfString:@" " withString:@""];

Why does modern Perl avoid UTF-8 by default?

You should enable the unicode strings feature, and this is the default if you use v5.14;

You should not really use unicode identifiers esp. for foreign code via utf8 as they are insecure in perl5, only cperl got that right. See e.g. http://perl11.org/blog/unicode-identifiers.html

Regarding utf8 for your filehandles/streams: You need decide by yourself the encoding of your external data. A library cannot know that, and since not even libc supports utf8, proper utf8 data is rare. There's more wtf8, the windows aberration of utf8 around.

BTW: Moose is not really "Modern Perl", they just hijacked the name. Moose is perfect Larry Wall-style postmodern perl mixed with Bjarne Stroustrup-style everything goes, with an eclectic aberration of proper perl6 syntax, e.g. using strings for variable names, horrible fields syntax, and a very immature naive implementation which is 10x slower than a proper implementation. cperl and perl6 are the true modern perls, where form follows function, and the implementation is reduced and optimized.

Sending data through POST request from a node.js server to a node.js server

Posting data is a matter of sending a query string (just like the way you would send it with an URL after the ?) as the request body.

This requires Content-Type and Content-Length headers, so the receiving server knows how to interpret the incoming data. (*)

var querystring = require('querystring');
var http = require('http');

var data = querystring.stringify({
      username: yourUsernameValue,
      password: yourPasswordValue
    });

var options = {
    host: 'my.url',
    port: 80,
    path: '/login',
    method: 'POST',
    headers: {
        'Content-Type': 'application/x-www-form-urlencoded',
        'Content-Length': Buffer.byteLength(data)
    }
};

var req = http.request(options, function(res) {
    res.setEncoding('utf8');
    res.on('data', function (chunk) {
        console.log("body: " + chunk);
    });
});

req.write(data);
req.end();

(*) Sending data requires the Content-Type header to be set correctly, i.e. application/x-www-form-urlencoded for the traditional format that a standard HTML form would use.

It's easy to send JSON (application/json) in exactly the same manner; just JSON.stringify() the data beforehand.

URL-encoded data supports one level of structure (i.e. key and value). JSON is useful when it comes to exchanging data that has a nested structure.

The bottom line is: The server must be able to interpret the content type in question. It could be text/plain or anything else; there is no need to convert data if the receiving server understands it as it is.

Add a charset parameter (e.g. application/json; charset=Windows-1252) if your data is in an unusual character set, i.e. not UTF-8. This can be necessary if you read it from a file, for example.

How can I run code on a background thread on Android?

Simple 3-Liner

A simple way of doing this that I found as a comment by @awardak in Brandon Rude's answer:

new Thread( new Runnable() { @Override public void run() { 
  // Run whatever background code you want here.
} } ).start();

I'm not sure if, or how , this is better than using AsyncTask.execute but it seems to work for us. Any comments as to the difference would be appreciated.

Thanks, @awardak!

C#: How to access an Excel cell?

How I work to automate Office / Excel:

  1. Record a macro, this will generate a VBA template
  2. Edit the VBA template so it will match my needs
  3. Convert to VB.Net (A small step for men)
  4. Leave it in VB.Net, Much more easy as doing it using C#

Pandas group-by and sum

Use GroupBy.sum:

df.groupby(['Fruit','Name']).sum()

Out[31]: 
               Number
Fruit   Name         
Apples  Bob        16
        Mike        9
        Steve      10
Grapes  Bob        35
        Tom        87
        Tony       15
Oranges Bob        67
        Mike       57
        Tom        15
        Tony        1

Determine number of pages in a PDF file

I have good success using CeTe Dynamic PDF products. They're not free, but are well documented. They did the job for me.

http://www.dynamicpdf.com/

Cannot set property 'innerHTML' of null

_x000D_
_x000D_
<!DOCTYPE HTML>_x000D_
<html>_x000D_
<head>_x000D_
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">_x000D_
<title>Untitled Document</title>_x000D_
</head>_x000D_
<body>_x000D_
<div id="hello"></div>_x000D_
<script type ="text/javascript">_x000D_
    what();_x000D_
    function what(){_x000D_
        document.getElementById('hello').innerHTML = 'hi';_x000D_
    };_x000D_
</script>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Is the ternary operator faster than an "if" condition in Java

For the example given, I prefer the ternary or condition operator (?) for a specific reason: I can clearly see that assigning a is not optional. With a simple example, it's not too hard to scan the if-else block to see that a is assigned in each clause, but imagine several assignments in each clause:

if (i == 0)
{
    a = 10;
    b = 6;
    c = 3;
}
else
{
    a = 5;
    b = 4;
    d = 1;
}

a = (i == 0) ? 10 : 5;
b = (i == 0) ? 6  : 4;
c = (i == 0) ? 3  : 9;
d = (i == 0) ? 12 : 1;

I prefer the latter so that you know you haven't missed an assignment.

Run/install/debug Android applications over Wi-Fi?

If you are using Android 11 click on the build version many times to activate the developer option then go to Settings>Advanced>Developer options. Scroll to debugging and turn on the "Wireless debugging" checkbox. Then open the menu debugging by touching the "Wireless debugging". Select "Pair device with paring code" and you will see the address for pairing with a pairing code. write this command in your desktop terminal to pair with your Android device.

adb pair 192.168.XXX.XXX:XXXX   <--------- the address showing on screen under paring code

Use the paring code to connect.

But wait we are not connected to adb yet. After you have successfully paired your device once. You can connect your adb anytime you turn on your Wireless debug option. To connect your adb every time before you use it from now on you don't need the pairing address anymore instead you will use the given address that shows when you enter the Wireless debug menu.

adb connect 192.168.XXX.XXX:XXXX    <--- this address shows inside wireless debug menu

can you add HTTPS functionality to a python flask web server?

Don't use openssl or pyopenssl its now become obselete in python

Refer the Code below

from flask import Flask, jsonify
import os

ASSETS_DIR = os.path.dirname(os.path.abspath(__file__))
app = Flask(__name__)


@app.route('/')
def index():
    return 'Flask is running!'


@app.route('/data')
def names():
    data = {"names": ["John", "Jacob", "Julie", "Jennifer"]}
    return jsonify(data)


if __name__ == '__main__':
    context = ('local.crt', 'local.key')#certificate and key files
    app.run(debug=True, ssl_context=context)

Cannot connect to the Docker daemon at unix:/var/run/docker.sock. Is the docker daemon running?

You can try out this:

systemctl start docker

It worked fine for me.

P.S.: after if there is commands that you can't do without sudo, try this:

gpasswd -a $USER docker

PHP remove special character from string

You want str replace, because performance-wise it's much cheaper and still fits your needs!

$title = str_replace( array( '\'', '"', ',' , ';', '<', '>' ), ' ', $rawtitle);

(Unless this is all about security and sql injection, in that case, I'd rather to go with a POSITIVE list of ALLOWED characters... even better, stick with tested, proven routines.)

Btw, since the OP talked about title-setting: I wouldn't replace special chars with nothing, but with a space. A superficious space is less of a problem than two words glued together...

How to add percent sign to NSString

uese following code.

 NSString *searchText = @"Bhupi"
 NSString *formatedSearchText = [NSString stringWithFormat:@"%%%@%%",searchText];

will output: %Bhupi%

Performing Breadth First Search recursively

I had to implement a heap traversal which outputs in a BFS order. It isn't actually BFS but accomplishes the same task.

private void getNodeValue(Node node, int index, int[] array) {
    array[index] = node.value;
    index = (index*2)+1;

    Node left = node.leftNode;
    if (left!=null) getNodeValue(left,index,array);
    Node right = node.rightNode;
    if (right!=null) getNodeValue(right,index+1,array);
}

public int[] getHeap() {
    int[] nodes = new int[size];
    getNodeValue(root,0,nodes);
    return nodes;
}

GCC -fPIC option

Code that is built into shared libraries should normally be position-independent code, so that the shared library can readily be loaded at (more or less) any address in memory. The -fPIC option ensures that GCC produces such code.

Beautiful Soup and extracting a div and its contents by ID

from bs4 import BeautifulSoup
from requests_html import HTMLSession

url = 'your_url'
session = HTMLSession()
resp = session.get(url)

# if element with id "articlebody" is dynamic, else need not to render
resp.html.render()

soup = bs(resp.html.html, "lxml")
soup.find("div", {"id": "articlebody"})

Update Row if it Exists Else Insert Logic with Entity Framework

Ladislav's answer was close but I had to made a couple of modifications to get this to work in EF6 (database-first). I extended my data context with my on AddOrUpdate method and so far this appears to be working well with detached objects:

using System.Data.Entity;

[....]

public partial class MyDBEntities {

  public void AddOrUpdate(MyDBEntities ctx, DbSet set, Object obj, long ID) {
      if (ID != 0) {
          set.Attach(obj);
          ctx.Entry(obj).State = EntityState.Modified;
      }
      else {
          set.Add(obj);
      }
  }
[....]

How do we update URL or query strings using javascript/jQuery without reloading the page?

Define a new URL object, assign it the current url, append your parameter(s) to that URL object and finally push it to your browsers state.

var url = new URL(window.location.href);
//var url = new URL(window.location.origin + window.location.pathname) <- flush existing parameters
url.searchParams.append("order", orderId);
window.history.pushState(null, null, url);

List of foreign keys and the tables they reference in Oracle DB

I know it's kinda late to answer but let me answer anyway, some of the answers above are quite complicated hence here is a much simpler take.

SELECT a.table_name child_table, a.column_name child_column, a.constraint_name, 
      b.table_name parent_table, b.column_name parent_column
  FROM all_cons_columns a
  JOIN all_constraints c ON a.owner = c.owner AND a.constraint_name = c.constraint_name
 join all_cons_columns b on c.owner = b.owner and c.r_constraint_name = b.constraint_name
 WHERE c.constraint_type = 'R'
   AND a.table_name = 'your table name'

What's the difference between a 302 and a 307 redirect?

307 came about because user agents adopted as a de facto behaviour to take POST requests that receive a 302 response and send a GET request to the Location response header.

That is the incorrect behaviour — only a 303 should cause a POST to turn into a GET. User agents should (but don't) stick with the POST method when requesting the new URL if the original POST request returned a 302.

307 was introduced to allow servers to make it clear to the user agent that a method change should not be made by the client when following the Location response header.

Remove leading and trailing spaces?

Should be noted that strip() method would trim any leading and trailing whitespace characters from the string (if there is no passed-in argument). If you want to trim space character(s), while keeping the others (like newline), this answer might be helpful:

sample = '  some string\n'
sample_modified = sample.strip(' ')

print(sample_modified)  # will print 'some string\n'

strip([chars]): You can pass in optional characters to strip([chars]) method. Python will look for occurrences of these characters and trim the given string accordingly.

Func vs. Action vs. Predicate

The difference between Func and Action is simply whether you want the delegate to return a value (use Func) or not (use Action).

Func is probably most commonly used in LINQ - for example in projections:

 list.Select(x => x.SomeProperty)

or filtering:

 list.Where(x => x.SomeValue == someOtherValue)

or key selection:

 list.Join(otherList, x => x.FirstKey, y => y.SecondKey, ...)

Action is more commonly used for things like List<T>.ForEach: execute the given action for each item in the list. I use this less often than Func, although I do sometimes use the parameterless version for things like Control.BeginInvoke and Dispatcher.BeginInvoke.

Predicate is just a special cased Func<T, bool> really, introduced before all of the Func and most of the Action delegates came along. I suspect that if we'd already had Func and Action in their various guises, Predicate wouldn't have been introduced... although it does impart a certain meaning to the use of the delegate, whereas Func and Action are used for widely disparate purposes.

Predicate is mostly used in List<T> for methods like FindAll and RemoveAll.

How is TeamViewer so fast?

Oddly. but in my experience TeamViewer is not faster/more responsive than VNC, only easier to setup. I have a couple of win-boxen that I VNC over OpenVPN into (so there is another overhead layer) and that's on cheap Cable (512 up) and I find properly setup TightVNC to be much more responsive than TeamViewer to same boxen. RDP (naturally) even more so since by large part it sends GUI draw commands instead of bitmap tiles.

Which brings us to:

  1. Why are you not using VNC? There are plethora of open source solutions, and Tight is probably on top of it's game right now.

  2. Advanced VNC implementations use lossy compression and that seems to achieve better results than your choice of PNG. Also, IIRC the rest of the payload is also squashed using zlib. Bothj Tight and UltraVNC have very optimized algos, especially for windows. On top of that Tight is open-source.

  3. If win boxen are your primary target RDP may be a better option, and has an opensource implementation (rdesktop)

  4. If *nix boxen are your primary target NX may be a better option and has an open source implementation (FreeNX, albeit not as optimised as NoMachine's proprietary product).

If compressing JPEG is a performance issue for your algo, I'm pretty sure that image comparison would still take away some performance. I'd bet they use best-case compression for every specific situation ie lossy for large frames, some quick and dirty internall losless for smaller ones, compare bits of images and send only diffs of sort and bunch of other optimisation tricks.

And a lot of those tricks must be present in Tight > 2.0 since again, in my experience it beats the hell out of TeamViewer performance wyse, YMMV.

Also the choice of a JIT compiled runtime over something like C++ might take a slice from your performance edge, especially in memory constrained machines (a lot of performance tuning goes to the toilet when windows start using the pagefile intensively). And you will need memory to keep previous image states for internal comparison atop of what DF mirage gives you.

UIBarButtonItem in navigation bar programmatically?

I have same issue and I have read answers in another topic then I solve another similar way. I do not know which is more effective. similar issue

//play button

@IBAction func startIt(sender: AnyObject) {
    startThrough();
};

//play button

func startThrough() {
    timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: Selector("updateTime"), userInfo: nil, repeats: true);

    let pauseButton = UIBarButtonItem(barButtonSystemItem: .Pause, target: self, action: "pauseIt");
    self.toolBarIt.items?.removeLast();
    self.toolBarIt.items?.append( pauseButton );
}

func pauseIt() {
    timer.invalidate();

    let play = UIBarButtonItem(barButtonSystemItem: .Play, target: self, action: "startThrough");
    self.toolBarIt.items?.removeLast();
    self.toolBarIt.items?.append( play );
}

NumPy array is not JSON serializable

Use the json.dumps default kwarg:

default should be a function that gets called for objects that can’t otherwise be serialized. ... or raise a TypeError

In the default function check if the object is from the module numpy, if so either use ndarray.tolist for a ndarray or use .item for any other numpy specific type.

import numpy as np

def default(obj):
    if type(obj).__module__ == np.__name__:
        if isinstance(obj, np.ndarray):
            return obj.tolist()
        else:
            return obj.item()
    raise TypeError('Unknown type:', type(obj))

dumped = json.dumps(data, default=default)

How to get Maven project version to the bash command line

There is also one option without need Maven:

grep -oPm1 "(?<=<version>)[^<]+" "pom.xml"

How to find out line-endings in a text file?

In vi...

:set list to see line-endings.

:set nolist to go back to normal.

While I don't think you can see \n or \r\n in vi, you can see which type of file it is (UNIX, DOS, etc.) to infer which line endings it has...

:set ff

Alternatively, from bash you can use od -t c <filename> or just od -c <filename> to display the returns.

How do I remove a MySQL database?

From the MySQL prompt:

mysql> drop database <db_name>;

Get full path without filename from path that includes filename

Path.GetDirectoryName() returns the directory name, so for what you want (with the trailing reverse solidus character) you could call Path.GetDirectoryName(filePath) + Path.DirectorySeparatorChar.

How to call VS Code Editor from terminal / command line

This works for Windows:

CMD> start vscode://file/o:/git/libzmq/builds/msvc/vs2017/libzmq.sln

But if the filepath has spaces, normally one would add double quotes around it, like this:

CMD> start "vscode://file/o:/git/lib zmq/builds/msvc/vs2017/libzmq.sln"

But this messes up with start, which can take a double-quoted title, so it will create a window with this name as the title and not open the project.

CMD> start "title" "vscode://file/o:/git/lib zmq/builds/msvc/vs2017/libzmq.sln"

PHP - regex to allow letters and numbers only

1. Use PHP's inbuilt ctype_alnum

You dont need to use a regex for this, PHP has an inbuilt function ctype_alnum which will do this for you, and execute faster:

<?php
$strings = array('AbCd1zyZ9', 'foo!#$bar');
foreach ($strings as $testcase) {
    if (ctype_alnum($testcase)) {
        echo "The string $testcase consists of all letters or digits.\n";
    } else {
        echo "The string $testcase does not consist of all letters or digits.\n";
    }
}
?>

2. Alternatively, use a regex

If you desperately want to use a regex, you have a few options.

Firstly:

preg_match('/^[\w]+$/', $string);

\w includes more than alphanumeric (it includes underscore), but includes all of \d.

Alternatively:

/^[a-zA-Z\d]+$/

Or even just:

/^[^\W_]+$/

Remove row lines in twitter bootstrap

This is what worked for me..

.table-no-border>thead>tr>th, 
.table-no-border>tbody>tr>th, 
.table-no-border>tfoot>tr>th, 
.table-no-border>thead>tr>td, 
.table-no-border>tbody>tr>td, 
.table-no-border>tfoot>tr>td,
.table-no-border>tbody,
.table-no-border>thead,
.table-no-border>tfoot{
  border-top: none !important; 
  border-bottom: none !important; 
}

Had to whip out the !important to make it stick.

Replace all whitespace with a line break/paragraph mark to make a word list

For reasonably modern versions of sed, edit the standard input to yield the standard output with

$ echo 't???? ß?ß??? ?? ??p??' | sed -E -e 's/[[:blank:]]+/\n/g'
t????
ß?ß???
??
??p??

If your vocabulary words are in files named lesson1 and lesson2, redirect sed’s standard output to the file all-vocab with

sed -E -e 's/[[:blank:]]+/\n/g' lesson1 lesson2 > all-vocab

What it means:

  • The character class [[:blank:]] matches either a single space character or a single tab character.
    • Use [[:space:]] instead to match any single whitespace character (commonly space, tab, newline, carriage return, form-feed, and vertical tab).
    • The + quantifier means match one or more of the previous pattern.
    • So [[:blank:]]+ is a sequence of one or more characters that are all space or tab.
  • The \n in the replacement is the newline that you want.
  • The /g modifier on the end means perform the substitution as many times as possible rather than just once.
  • The -E option tells sed to use POSIX extended regex syntax and in particular for this case the + quantifier. Without -E, your sed command becomes sed -e 's/[[:blank:]]\+/\n/g'. (Note the use of \+ rather than simple +.)

Perl Compatible Regexes

For those familiar with Perl-compatible regexes and a PCRE-capable sed, use \s+ to match runs of at least one whitespace character, as in

sed -E -e 's/\s+/\n/g' old > new

or

sed -e 's/\s\+/\n/g' old > new

These commands read input from the file old and write the result to a file named new in the current directory.

Maximum portability, maximum cruftiness

Going back to almost any version of sed since Version 7 Unix, the command invocation is a bit more baroque.

$ echo 't???? ß?ß??? ?? ??p??' | sed -e 's/[ \t][ \t]*/\
/g'
t????
ß?ß???
??
??p??

Notes:

  • Here we do not even assume the existence of the humble + quantifier and simulate it with a single space-or-tab ([ \t]) followed by zero or more of them ([ \t]*).
  • Similarly, assuming sed does not understand \n for newline, we have to include it on the command line verbatim.
    • The \ and the end of the first line of the command is a continuation marker that escapes the immediately following newline, and the remainder of the command is on the next line.
      • Note: There must be no whitespace preceding the escaped newline. That is, the end of the first line must be exactly backslash followed by end-of-line.
    • This error prone process helps one appreciate why the world moved to visible characters, and you will want to exercise some care in trying out the command with copy-and-paste.

Note on backslashes and quoting

The commands above all used single quotes ('') rather than double quotes (""). Consider:

$ echo '\\\\' "\\\\"
\\\\ \\

That is, the shell applies different escaping rules to single-quoted strings as compared with double-quoted strings. You typically want to protect all the backslashes common in regexes with single quotes.

Plotting two variables as lines using ggplot2 on the same graph

You need the data to be in "tall" format instead of "wide" for ggplot2. "wide" means having an observation per row with each variable as a different column (like you have now). You need to convert it to a "tall" format where you have a column that tells you the name of the variable and another column that tells you the value of the variable. The process of passing from wide to tall is usually called "melting". You can use tidyr::gather to melt your data frame:

library(ggplot2)
library(tidyr)

test_data <-
  data.frame(
    var0 = 100 + c(0, cumsum(runif(49, -20, 20))),
    var1 = 150 + c(0, cumsum(runif(49, -10, 10))),
    date = seq(as.Date("2002-01-01"), by="1 month", length.out=100)
  )
test_data %>%
    gather(key,value, var0, var1) %>%
    ggplot(aes(x=date, y=value, colour=key)) +
    geom_line()

multiple series ggplot2

Just to be clear the data that ggplot is consuming after piping it via gather looks like this:

date        key     value
2002-01-01  var0    100.00000
2002-02-01  var0    115.16388 
...
2007-11-01  var1    114.86302
2007-12-01  var1    119.30996

Change WPF controls from a non-main thread using Dispatcher.Invoke

The @japf answer above is working fine and in my case I wanted to change the mouse cursor from a Spinning Wheel back to the normal Arrow once the CEF Browser finished loading the page. In case it can help someone, here is the code:

private void Browser_LoadingStateChanged(object sender, CefSharp.LoadingStateChangedEventArgs e) {
   if (!e.IsLoading) {
      // set the cursor back to arrow
      Application.Current.Dispatcher.BeginInvoke(DispatcherPriority.Background,
         new Action(() => Mouse.OverrideCursor = Cursors.Arrow));
   }
}

How to run vi on docker container?

Inside container(in docker, not in VM), by default these are not installed. Even apt-get, wget will not work. My VM is running on Ubuntu 17.10. For me yum package manaager worked.

Yum is not part of debian or ubuntu. It is part of red-hat. But, it works in Ubuntu and it is installed by default like apt-get

Tu install vim, use this command

yum install -y vim-enhanced 

To uninstall vim :

yum uninstall -y vim-enhanced 

Similarly,

yum install -y wget 
yum install -y sudo 

-y is for assuming yes if prompted for any qustion asked after doing yum install packagename

Is it possible to include one CSS file in another?

Yes.

@import "your.css";

The rule is documented here.

How do I use PHP to get the current year?

$year = date("Y", strtotime($yourDateVar));

How can you get the build/version number of your Android application?

This code was mentioned above in pieces, but here it is again all included. You need a try/catch block, because it may throw a "NameNotFoundException".

try {
    String appVersion = getPackageManager().getPackageInfo(getPackageName(), 0).versionName;
}
catch (PackageManager.NameNotFoundException e) {
    e.printStackTrace();
}

I hope this simplifies things for someone down the road. :)

How to copy to clipboard using Access/VBA?

VB 6 provides a Clipboard object that makes all of this extremely simple and convenient, but unfortunately that's not available from VBA.

If it were me, I'd go the API route. There's no reason to be scared of calling native APIs; the language provides you with the ability to do that for a reason.

However, a simpler alternative is to use the DataObject class, which is part of the Forms library. I would only recommend going this route if you are already using functionality from the Forms library in your app. Adding a reference to this library only to use the clipboard seems a bit silly.

For example, to place some text on the clipboard, you could use the following code:

Dim clipboard As MSForms.DataObject
Set clipboard = New MSForms.DataObject
clipboard.SetText "A string value"
clipboard.PutInClipboard

Or, to copy text from the clipboard into a string variable:

Dim clipboard As MSForms.DataObject
Dim strContents As String

Set clipboard = New MSForms.DataObject
clipboard.GetFromClipboard
strContents = clipboard.GetText

How to get parameters from a URL string?

I created function from @Ruel answer. You can use this:

function get_valueFromStringUrl($url , $parameter_name)
{
    $parts = parse_url($url);
    if(isset($parts['query']))
    {
        parse_str($parts['query'], $query);
        if(isset($query[$parameter_name]))
        {
            return $query[$parameter_name];
        }
        else
        {
            return null;
        }
    }
    else
    {
        return null;
    }
}

Example:

$url = "https://example.com/test/the-page-here/1234?someurl=key&[email protected]";
echo get_valueFromStringUrl($url , "email");

Thanks to @Ruel