Programs & Examples On #Getcustomattributes

Could not load type 'System.Runtime.CompilerServices.ExtensionAttribute' from assembly 'mscorlib

Could not load type 'System.Runtime.CompilerServices.ExtensionAttribute' from assembly mscorlib

Yes, this technically can go wrong when you execute code on .NET 4.0 instead of .NET 4.5. The attribute was moved from System.Core.dll to mscorlib.dll in .NET 4.5. While that sounds like a rather nasty breaking change in a framework version that is supposed to be 100% compatible, a [TypeForwardedTo] attribute is supposed to make this difference unobservable.

As Murphy would have it, every well intended change like this has at least one failure mode that nobody thought of. This appears to go wrong when ILMerge was used to merge several assemblies into one and that tool was used incorrectly. A good feedback article that describes this breakage is here. It links to a blog post that describes the mistake. It is rather a long article, but if I interpret it correctly then the wrong ILMerge command line option causes this problem:

  /targetplatform:"v4,c:\windows\Microsoft.NET\Framework\v4.0.30319"

Which is incorrect. When you install 4.5 on the machine that builds the program then the assemblies in that directory are updated from 4.0 to 4.5 and are no longer suitable to target 4.0. Those assemblies really shouldn't be there anymore but were kept for compat reasons. The proper reference assemblies are the 4.0 reference assemblies, stored elsewhere:

  /targetplatform:"v4,C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0"

So possible workarounds are to fall back to 4.0 on the build machine, install .NET 4.5 on the target machine and the real fix, to rebuild the project from the provided source code, fixing the ILMerge command.


Do note that this failure mode isn't exclusive to ILMerge, it is just a very common case. Any other scenario where these 4.5 assemblies are used as reference assemblies in a project that targets 4.0 is liable to fail the same way. Judging from other questions, another common failure mode is in build servers that were setup without using a valid VS license. And overlooking that the multi-targeting packs are a free download.

Using the reference assemblies in the c:\program files (x86) subdirectory is a rock hard requirement. Starting at .NET 4.0, already important to avoid accidentally taking a dependency on a class or method that was added in the 4.01, 4.02 and 4.03 releases. But absolutely essential now that 4.5 is released.

How to get C# Enum description from value?

I put the code together from the accepted answer in a generic extension method, so it could be used for all kinds of objects:

public static string DescriptionAttr<T>(this T source)
{
    FieldInfo fi = source.GetType().GetField(source.ToString());

    DescriptionAttribute[] attributes = (DescriptionAttribute[])fi.GetCustomAttributes(
        typeof(DescriptionAttribute), false);

    if (attributes != null && attributes.Length > 0) return attributes[0].Description;
    else return source.ToString();
}

Using an enum like in the original post, or any other class whose property is decorated with the Description attribute, the code can be consumed like this:

string enumDesc = MyEnum.HereIsAnother.DescriptionAttr();
string classDesc = myInstance.SomeProperty.DescriptionAttr();

How to get a list of properties with a given attribute?

As far as I know, there isn't any better way in terms of working with Reflection library in a smarter way. However, you could use LINQ to make the code a bit nicer:

var props = from p in t.GetProperties()
            let attrs = p.GetCustomAttributes(typeof(MyAttribute), true)
            where attrs.Length != 0 select p;

// Do something with the properties in 'props'

I believe this helps you to structure the code in a more readable fashion.

String representation of an Enum

Update: Visiting this page, 8 years later, after not touching C# for a long while, looks like my answer is no longer the best solution. I really like the converter solution tied with attribute-functions.

If you are reading this, please make sure you also check out other answers.
(hint: they are above this one)


As most of you, I really liked the selected answer by Jakub Šturc, but I also really hate to copy-paste code, and try to do it as little as I can.

So I decided I wanted an EnumBase class from which most of the functionality is inherited/built-in, leaving me to focus on the content instead of behavior.

The main problem with this approach is based on the fact that although Enum values are type-safe instances, the interaction is with the Static implementation of the Enum Class type. So with a little help of generics magic, I think I finally got the correct mix. Hope someone finds this as useful as I did.

I'll start with Jakub's example, but using inheritance and generics:

public sealed class AuthenticationMethod : EnumBase<AuthenticationMethod, int>
{
    public static readonly AuthenticationMethod FORMS =
        new AuthenticationMethod(1, "FORMS");
    public static readonly AuthenticationMethod WINDOWSAUTHENTICATION =
        new AuthenticationMethod(2, "WINDOWS");
    public static readonly AuthenticationMethod SINGLESIGNON =
        new AuthenticationMethod(3, "SSN");

    private AuthenticationMethod(int Value, String Name)
        : base( Value, Name ) { }
    public new static IEnumerable<AuthenticationMethod> All
    { get { return EnumBase<AuthenticationMethod, int>.All; } }
    public static explicit operator AuthenticationMethod(string str)
    { return Parse(str); }
}

And here is the base class:

using System;
using System.Collections.Generic;
using System.Linq; // for the .AsEnumerable() method call

// E is the derived type-safe-enum class
// - this allows all static members to be truly unique to the specific
//   derived class
public class EnumBase<E, T> where E: EnumBase<E, T>
{
    #region Instance code
    public T Value { get; private set; }
    public string Name { get; private set; }

    protected EnumBase(T EnumValue, string Name)
    {
        Value = EnumValue;
        this.Name = Name;
        mapping.Add(Name, this);
    }

    public override string ToString() { return Name; }
    #endregion

    #region Static tools
    static private readonly Dictionary<string, EnumBase<E, T>> mapping;
    static EnumBase() { mapping = new Dictionary<string, EnumBase<E, T>>(); }
    protected static E Parse(string name)
    {
        EnumBase<E, T> result;
        if (mapping.TryGetValue(name, out result))
        {
            return (E)result;
        }

        throw new InvalidCastException();
    }
    // This is protected to force the child class to expose it's own static
    // method.
    // By recreating this static method at the derived class, static
    // initialization will be explicit, promising the mapping dictionary
    // will never be empty when this method is called.
    protected static IEnumerable<E> All
    { get { return mapping.Values.AsEnumerable().Cast<E>(); } }
    #endregion
}

if else statement in AngularJS templates

Ternary is the most clear way of doing this.

<div>{{ConditionVar ? 'varIsTrue' : 'varIsFalse'}}</div>

What is the difference between Nexus and Maven?

Whatever I understood from my learning and what I think it is is here. I am Quoting some part from a book i learnt this things. Nexus Repository Manager and Nexus Repository Manager OSS started as a repository manager supporting the Maven repository format. While it supports many other repository formats now, the Maven repository format is still the most common and well supported format for build and provisioning tools running on the JVM and beyond. This chapter shows example configurations for using the repository manager with Apache Maven and a number of other tools. The setups take advantage of merging many repositories and exposing them via a repository group. Setting this up is documented in the chapter in addition to the configuration used by specific tools.

Details

Create an array with same element repeated multiple times

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var finalAry = [..."2".repeat(5).split("")].map(Number);_x000D_
console.log(finalAry);
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How to append elements into a dictionary in Swift?

To add new elements just set:

listParrameters["your parrameter"] = value

Python: IndexError: list index out of range

Here is your code. I'm assuming you're using python 3 based on the your use of print() and input():

import random

def main():
    #random.seed() --> don't need random.seed()

    #Prompts the user to enter the number of tickets they wish to play.

    #python 3 version:
    tickets = int(input("How many lottery tickets do you want?\n"))

    #Creates the dictionaries "winning_numbers" and "guess." Also creates the variable "winnings" for total amount of money won.
    winning_numbers = []
    winnings = 0

    #Generates the winning lotto numbers.
    for i in range(tickets * 5):
        #del winning_numbers[:] what is this line for?
        randNum = random.randint(1,30)
        while randNum in winning_numbers:    
            randNum = random.randint(1,30)
        winning_numbers.append(randNum)

    print(winning_numbers)
    guess = getguess(tickets)
    nummatches = checkmatch(winning_numbers, guess)

    print("Ticket #"+str(i+1)+": The winning combination was",winning_numbers,".You matched",nummatches,"number(s).\n")

    winningRanks = [0, 0, 10, 500, 20000, 1000000]

    winnings = sum(winningRanks[:nummatches + 1])

    print("You won a total of",winnings,"with",tickets,"tickets.\n")


#Gets the guess from the user.
def getguess(tickets):
    guess = []
    for i in range(tickets):
        bubble = [int(i) for i in input("What numbers do you want to choose for ticket #"+str(i+1)+"?\n").split()]
        guess.extend(bubble)
        print(bubble)
    return guess

#Checks the user's guesses with the winning numbers.
def checkmatch(winning_numbers, guess):
    match = 0
    for i in range(5):
        if guess[i] == winning_numbers[i]:
            match += 1
    return match

main()

Pycharm and sys.argv arguments

Add the following to the top of your Python file.

import sys

sys.argv = [
    __file__,
    'arg1',
    'arg2'
]

Now, you can simply right click on the Python script.

Using <style> tags in the <body> with other HTML

As others have already mentioned, HTML 4 requires the <style> tag to be placed in the <head> section (even though most browsers allow <style> tags within the body).

However, HTML 5 includes the scoped attribute (see update below), which allows you to create style sheets that are scoped within the parent element of the <style> tag. This also enables you to place <style> tags within the <body> element:

<!DOCTYPE html>
<html>
<head></head>
<body>

<div id="scoped-content">
    <style type="text/css" scoped>
        h1 { color: red; } 
    </style>

    <h1>Hello</h1>
</div>

    <h1>
      World
    </h1>

</body>
</html>

If you render the above code in an HTML-5 enabled browser that supports scoped, you will see the limited scope of the style sheet.

There's just one major caveat...

At the time I'm writing this answer (May, 2013) almost no mainstream browser currently supports the scoped attribute. (Although apparently developer builds of Chromium support it.)

HOWEVER, there is an interesting implication of the scoped attribute that pertains to this question. It means that future browsers are mandated via the standard to allow <style> elements within the <body> (as long as the <style> elements are scoped.)

So, given that:

  • Almost every existing browser currently ignores the scoped attribute
  • Almost every existing browser currently allows <style> tags within the <body>
  • Future implementations will be required to allow (scoped) <style> tags within the <body>

...then there is literally no harm * in placing <style> tags within the body, as long as you future proof them with a scoped attribute. The only problem is that current browsers won't actually limit the scope of the stylesheet - they'll apply it to the whole document. But the point is that, for all practical purposes, you can include <style> tags within the <body> provided that you:

  • Future-proof your HTML by including the scoped attribute
  • Understand that as of now, the stylesheet within the <body> will not actually be scoped (because no mainstream browser support exists yet)


* except of course, for pissing off HTML validators...


Finally, regarding the common (but subjective) claim that embedding CSS within HTML is poor practice, it should be noted that the whole point of the scoped attribute is to accommodate typical modern development frameworks that allow developers to import chunks of HTML as modules or syndicated content. It is very convenient to have embedded CSS that only applies to a particular chunk of HTML, in order to develop encapsulated, modular components with specific stylings.


Update as of Feb 2019, according to the Mozilla documentation, the scoped attribute is deprecated. Chrome stopped supporting it in version 36 (2014) and Firefox in version 62 (2018). In both cases, the feature had to be explicitly enabled by the user in the browsers' settings. No other major browser ever supported it.

SQLite3 database or disk is full / the database disk image is malformed

To repair a corrupt database you can use the sqlite3 commandline utility. Type in the following commands in a shell after setting the environment variables:

cd $DATABASE_LOCATION
echo '.dump'|sqlite3 $DB_NAME|sqlite3 repaired_$DB_NAME
mv $DB_NAME corrupt_$DB_NAME
mv repaired_$DB_NAME $DB_NAME

This code helped me recover a SQLite database I use as a persistent store for Core Data and which produced the following error upon save:

Could not save: NSError 259 in Domain NSCocoaErrorDomain { NSFilePath = mydata.db NSUnderlyingException = Fatal error. The database at mydata.db is corrupted. SQLite error code:11, 'database disk image is malformed' }

Differences between fork and exec

fork() creates a copy of the current process, with execution in the new child starting from just after the fork() call. After the fork(), they're identical, except for the return value of the fork() function. (RTFM for more details.) The two processes can then diverge still further, with one unable to interfere with the other, except possibly through any shared file handles.

exec() replaces the current process with a new one. It has nothing to do with fork(), except that an exec() often follows fork() when what's wanted is to launch a different child process, rather than replace the current one.

Where to change default pdf page width and font size in jspdf.debug.js?

Besides using one of the default formats you can specify any size you want in the unit you specify.

For example:

// Document of 210mm wide and 297mm high
new jsPDF('p', 'mm', [297, 210]);
// Document of 297mm wide and 210mm high
new jsPDF('l', 'mm', [297, 210]);
// Document of 5 inch width and 3 inch high
new jsPDF('l', 'in', [3, 5]);

The 3rd parameter of the constructor can take an array of the dimensions. However they do not correspond to width and height, instead they are long side and short side (or flipped around).

Your 1st parameter (landscape or portrait) determines what becomes the width and the height.

In the sourcecode on GitHub you can see the supported units (relative proportions to pt), and you can also see the default page formats (with their sizes in pt).

Launch Image does not show up in my iOS App

After several hours frustrated on this, I decided to use this way. It works for both iPhone and iPad (on Xcode 6.1)

  1. File >> New File >> User Interface >> Launch Screen
  2. Create new key/value: "Launch screen interface file base name"/"Your Launch Screen Name" in YourApp-Info.plist

1 picture worths more than thousand words. Please look at below:

File>>New File>> User Interface >> Launch Screen

Create new key/value "Launch screen interface file base name"/"Your Launch Screen Name" in YourApp-Info.plist

Java way to check if a string is palindrome

check this condition

String string="//some string...//"

check this... if(string.equals((string.reverse()) { it is palindrome }

How do I do a bulk insert in mySQL using node.js

I was looking around for an answer on bulk inserting Objects.

The answer by Ragnar123 led me to making this function:

function bulkInsert(connection, table, objectArray, callback) {
  let keys = Object.keys(objectArray[0]);
  let values = objectArray.map( obj => keys.map( key => obj[key]));
  let sql = 'INSERT INTO ' + table + ' (' + keys.join(',') + ') VALUES ?';
  connection.query(sql, [values], function (error, results, fields) {
    if (error) callback(error);
    callback(null, results);
  });
}

bulkInsert(connection, 'my_table_of_objects', objectArray, (error, response) => {
  if (error) res.send(error);
  res.json(response);
});

Hope it helps!

scatter plot in matplotlib

Maybe something like this:

import matplotlib.pyplot
import pylab

x = [1,2,3,4]
y = [3,4,8,6]

matplotlib.pyplot.scatter(x,y)

matplotlib.pyplot.show()

EDIT:

Let me see if I understand you correctly now:

You have:

       test1 | test2 | test3
test3 |   1   |   0  |  1

test4 |   0   |   1  |  0

test5 |   1   |   1  |  0

Now you want to represent the above values in in a scatter plot, such that value of 1 is represented by a dot.

Let's say you results are stored in a 2-D list:

results = [[1, 0, 1], [0, 1, 0], [1, 1, 0]]

We want to transform them into two variables so we are able to plot them.

And I believe this code will give you what you are looking for:

import matplotlib
import pylab


results = [[1, 0, 1], [0, 1, 0], [1, 1, 0]]

x = []
y = []

for ind_1, sublist in enumerate(results):
    for ind_2, ele in enumerate(sublist):
        if ele == 1:
            x.append(ind_1)
            y.append(ind_2)       


matplotlib.pyplot.scatter(x,y)

matplotlib.pyplot.show()

Notice that I do need to import pylab, and you would have play around with the axis labels. Also this feels like a work around, and there might be (probably is) a direct method to do this.

Express-js wildcard routing to cover everything under and including a path

It is not necessary to have two routes.

Simply add (/*)? at the end of your path string.

For example, app.get('/hello/world(/*)?' /* ... */)

Here is a fully working example, feel free to copy and paste this into a .js file to run with node, and play with it in a browser (or curl):

const app = require('express')()

// will be able to match all of the following
const test1 = 'http://localhost:3000/hello/world'
const test2 = 'http://localhost:3000/hello/world/'
const test3 = 'http://localhost:3000/hello/world/with/more/stuff'

// but fail at this one
const failTest = 'http://localhost:3000/foo/world'

app.get('/hello/world(/*)?', (req, res) => res.send(`
    This will match at example endpoints: <br><br>
    <pre><a href="${test1}">${test1}</a></pre>
    <pre><a href="${test2}">${test2}</a></pre>
    <pre><a href="${test3}">${test3}</a></pre>

    <br><br> Will NOT match at: <pre><a href="${failTest}">${failTest}</a></pre>
`))

app.listen(3000, () => console.log('Check this out in a browser at http://localhost:3000/hello/world!'))

How to delete an element from an array in C#

You can also convert your array to a list and call remove on the list. You can then convert back to your array.

int[] numbers = {1, 3, 4, 9, 2};
var numbersList = numbers.ToList();
numbersList.Remove(4);

How do I select a random value from an enumeration?

You can also cast a random value:

using System;

enum Test {
  Value1,
  Value2,
  Value3
}

class Program {
  public static void Main (string[] args) {
    var max = Enum.GetValues(typeof(Test)).Length;
    var value = (Test)new Random().Next(0, max - 1);
    Console.WriteLine(value);
  }
}

But you should use a better randomizer like the one in this library of mine.

The application may be doing too much work on its main thread

After doing much R&D on this issue I got the Solution,

In my case I am using Service that will run every 2 second and with the runonUIThread, I was wondering the problem was there but not at all. The next issue that I found is that I am using large Image in may App and thats the problem.

I removed the Images and set new Images.

Conclusion :- Look into your code is there any raw file that you are using is of big size.

Show and hide divs at a specific time interval using jQuery

Working Example here - add /edit to the URL to play with the code

You just need to use JavaScript setInterval function

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$('html').addClass('js');_x000D_
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$(function() {_x000D_
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  var timer = setInterval(showDiv, 5000);_x000D_
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  var counter = 0;_x000D_
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  function showDiv() {_x000D_
    if (counter == 0) {_x000D_
      counter++;_x000D_
      return;_x000D_
    }_x000D_
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    $('div', '#container')_x000D_
      .stop()_x000D_
      .hide()_x000D_
      .filter(function() {_x000D_
        return this.id.match('div' + counter);_x000D_
      })_x000D_
      .show('fast');_x000D_
    counter == 3 ? counter = 0 : counter++;_x000D_
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  }_x000D_
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});
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<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"_x000D_
       "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">_x000D_
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">_x000D_
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<head>_x000D_
  <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>_x000D_
  <title>Sandbox</title>_x000D_
  <meta http-equiv="Content-type" content="text/html; charset=utf-8" />_x000D_
  <style type="text/css" media="screen">_x000D_
    body {_x000D_
      background-color: #fff;_x000D_
      font: 16px Helvetica, Arial;_x000D_
      color: #000;_x000D_
    }_x000D_
    _x000D_
    .display {_x000D_
      width: 300px;_x000D_
      height: 200px;_x000D_
      border: 2px solid #000;_x000D_
    }_x000D_
    _x000D_
    .js .display {_x000D_
      display: none;_x000D_
    }_x000D_
  </style>_x000D_
</head>_x000D_
_x000D_
<body>_x000D_
  <h2>Example of using setInterval to trigger display of Div</h2>_x000D_
  <p>The first div will display after 10 seconds...</p>_x000D_
  <div id='container'>_x000D_
    <div id='div1' class='display' style="background-color: red;">_x000D_
      div1_x000D_
    </div>_x000D_
    <div id='div2' class='display' style="background-color: green;">_x000D_
      div2_x000D_
    </div>_x000D_
    <div id='div3' class='display' style="background-color: blue;">_x000D_
      div3_x000D_
    </div>_x000D_
    <div>_x000D_
</body>_x000D_
_x000D_
</html>
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EDIT:

In response to your comment about the container div, just modify this

$('div','#container')

to this

$('#div1, #div2, #div3')

Recursive mkdir() system call on Unix

Here's another take on mkpath(), using recursion, which is both small and readable. It makes use of strdupa() to avoid altering the given dir string argument directly and to avoid using malloc() & free(). Make sure to compile with -D_GNU_SOURCE to activate strdupa() ... meaning this code only works on GLIBC, EGLIBC, uClibc, and other GLIBC compatible C libraries.

int mkpath(char *dir, mode_t mode)
{
    if (!dir) {
        errno = EINVAL;
        return 1;
    }

    if (strlen(dir) == 1 && dir[0] == '/')
        return 0;

    mkpath(dirname(strdupa(dir)), mode);

    return mkdir(dir, mode);
}

After input both here and from Valery Frolov, in the Inadyn project, the following revised version of mkpath() has now been pushed to libite

int mkpath(char *dir, mode_t mode)
{
    struct stat sb;

    if (!dir) {
        errno = EINVAL;
        return 1;
    }

    if (!stat(dir, &sb))
        return 0;

    mkpath(dirname(strdupa(dir)), mode);

    return mkdir(dir, mode);
}

It uses one more syscall, but otoh the code is more readable now.

Maven - Failed to execute goal org.apache.maven.plugins:maven-clean-plugin:2.4.1:clean

I've noticed that sometimes eclipse somehow picks up some of the jars and keeps a lock on them (in Windows only) and when you try to do mvn clean it says:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-clean-plugin:2.2:clean (default-clean) on project

The only solution so far is to close eclipse and run the mvn build again.

And these are random jars - it can pick up anything it wants... Why that happens is a mystery to me. Probably eclipse opens the jars when you do Type Search or Resource Search and forgets to close them / release the file handlers..

System.Net.WebException: The remote name could not be resolved:

Open the hosts file located at : **C:\windows\system32\drivers\etc**.

Hosts file is for what?

Add the following at end of this file :

YourServerIP YourDNS

Example:

198.168.1.1 maps.google.com

td widths, not working?

It should be:

<td width="200">

or

<td style="width: 200px">

Note that if your cell contains some content that doesn't fit into the 200px (like somelongwordwithoutanyspaces), the cell will stretch nevertheless, unless your CSS contains table-layout: fixed for the table.

EDIT

As kristina childs noted on her answer, you should avoid both the width attribute and using inline CSS (with the style attribute). It's a good practice to separate style and structure as much as possible.

MySQL "between" clause not inclusive?

select * from person where DATE(dob) between '2011-01-01' and '2011-01-31'

Surprisingly such conversions are solutions to many problems in MySQL.

class method generates "TypeError: ... got multiple values for keyword argument ..."

just add 'staticmethod' decorator to function and problem is fixed

class foo(object):
    @staticmethod
    def foodo(thing=None, thong='not underwear'):
        print thing if thing else "nothing" 
        print 'a thong is',thong

How to use && in EL boolean expressions in Facelets?

In addition to the answer of BalusC, use the following Java RegExp to replace && with and:

Search:  (#\{[^\}]*)(&&)([^\}]*\})
Replace: $1and$3

You have run this regular expression replacement multiple times to find all occurences in case you are using >2 literals in your EL expressions. Mind to replace the leading # by $ if your EL expression syntax differs.

XML to CSV Using XSLT

This CsvEscape function is XSLT 1.0 and escapes column values ,, ", and newlines like RFC 4180 or Excel. It makes use of the fact that you can recursively call XSLT templates:

  • The template EscapeQuotes replaces all double quotes with 2 double quotes, recursively from the start of the string.
  • The template CsvEscape checks if the text contains a comma or double quote, and if so surrounds the whole string with a pair of double quotes and calls EscapeQuotes for the string.

Example usage: xsltproc xmltocsv.xslt file.xml > file.csv

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="text" encoding="UTF-8"/>

  <xsl:template name="EscapeQuotes">
    <xsl:param name="value"/>
    <xsl:choose>
      <xsl:when test="contains($value,'&quot;')">
    <xsl:value-of select="substring-before($value,'&quot;')"/>
    <xsl:text>&quot;&quot;</xsl:text>
    <xsl:call-template name="EscapeQuotes">
      <xsl:with-param name="value" select="substring-after($value,'&quot;')"/>
    </xsl:call-template>
      </xsl:when>
      <xsl:otherwise>
    <xsl:value-of select="$value"/>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:template>

  <xsl:template name="CsvEscape">
    <xsl:param name="value"/>
    <xsl:choose>
    <xsl:when test="contains($value,',')">
      <xsl:text>&quot;</xsl:text>
      <xsl:call-template name="EscapeQuotes">
    <xsl:with-param name="value" select="$value"/>
      </xsl:call-template>
      <xsl:text>&quot;</xsl:text>
    </xsl:when>
    <xsl:when test="contains($value,'&#xA;')">
      <xsl:text>&quot;</xsl:text>
      <xsl:call-template name="EscapeQuotes">
    <xsl:with-param name="value" select="$value"/>
      </xsl:call-template>
      <xsl:text>&quot;</xsl:text>
    </xsl:when>
    <xsl:when test="contains($value,'&quot;')">
      <xsl:text>&quot;</xsl:text>
      <xsl:call-template name="EscapeQuotes">
    <xsl:with-param name="value" select="$value"/>
      </xsl:call-template>
      <xsl:text>&quot;</xsl:text>
    </xsl:when>
    <xsl:otherwise>
      <xsl:value-of select="$value"/>
    </xsl:otherwise>
    </xsl:choose>
  </xsl:template>

  <xsl:template match="/">
    <xsl:text>project,name,language,owner,state,startDate</xsl:text>
    <xsl:text>&#xA;</xsl:text>
    <xsl:for-each select="projects/project">
      <xsl:call-template name="CsvEscape"><xsl:with-param name="value" select="normalize-space(name)"/></xsl:call-template>
      <xsl:text>,</xsl:text>
      <xsl:call-template name="CsvEscape"><xsl:with-param name="value" select="normalize-space(language)"/></xsl:call-template>
      <xsl:text>,</xsl:text>
      <xsl:call-template name="CsvEscape"><xsl:with-param name="value" select="normalize-space(owner)"/></xsl:call-template>
      <xsl:text>,</xsl:text>
      <xsl:call-template name="CsvEscape"><xsl:with-param name="value" select="normalize-space(state)"/></xsl:call-template>
      <xsl:text>,</xsl:text>
      <xsl:call-template name="CsvEscape"><xsl:with-param name="value" select="normalize-space(startDate)"/></xsl:call-template>
      <xsl:text>&#xA;</xsl:text>
    </xsl:for-each>
  </xsl:template>
</xsl:stylesheet>

Converting HTML to Excel?

Change the content type to ms-excel in the html and browser shall open the html in the Excel as xls. If you want control over the transformation of HTML to excel use POI libraries to do so.

SQLAlchemy ORDER BY DESCENDING?

from sqlalchemy import desc
someselect.order_by(desc(table1.mycol))

Usage from @jpmc26

How To Set Text In An EditText

String text = "Example";
EditText edtText = (EditText) findViewById(R.id.edtText);
edtText.setText(text);

Check it out EditText accept only String values if necessary convert it to string.

If int, double, long value, do:

String.value(value);

Good tutorial for using HTML5 History API (Pushstate?)

You may want to take a look at this jQuery plugin. They have lots of examples on their site. http://www.asual.com/jquery/address/

Best place to insert the Google Analytics code

If you want your scripts to load after page has been rendered, you can use:

function getScript(a, b) {
    var c = document.createElement("script");
    c.src = a;
    var d = document.getElementsByTagName("head")[0],
        done = false;
    c.onload = c.onreadystatechange = function() {
        if (!done && (!this.readyState || this.readyState == "loaded" || this.readyState == "complete")) {
            done = true;
            b();
            c.onload = c.onreadystatechange = null;
            d.removeChild(c)
        }
    };
    d.appendChild(c)
}

//call the function
getScript("http://www.google-analytics.com/ga.js", function() {
    // do stuff after the script has loaded
});

Single line if statement with 2 actions

Sounds like you really want a Dictionary<int, string> or possibly a switch statement...

You can do it with the conditional operator though:

userType = user.Type == 0 ? "Admin"
         : user.Type == 1 ? "User"
         : user.Type == 2 ? "Employee"
         : "The default you didn't specify";

While you could put that in one line, I'd strongly urge you not to.

I would normally only do this for different conditions though - not just several different possible values, which is better handled in a map.

Create JPA EntityManager without persistence.xml configuration file

Is there a way to initialize the EntityManager without a persistence unit defined?

You should define at least one persistence unit in the persistence.xml deployment descriptor.

Can you give all the required properties to create an Entitymanager?

  • The name attribute is required. The other attributes and elements are optional. (JPA specification). So this should be more or less your minimal persistence.xml file:
<persistence>
    <persistence-unit name="[REQUIRED_PERSISTENCE_UNIT_NAME_GOES_HERE]">
        SOME_PROPERTIES
    </persistence-unit>
</persistence>

In Java EE environments, the jta-data-source and non-jta-data-source elements are used to specify the global JNDI name of the JTA and/or non-JTA data source to be used by the persistence provider.

So if your target Application Server supports JTA (JBoss, Websphere, GlassFish), your persistence.xml looks like:

<persistence>
    <persistence-unit name="[REQUIRED_PERSISTENCE_UNIT_NAME_GOES_HERE]">
        <!--GLOBAL_JNDI_GOES_HERE-->
        <jta-data-source>jdbc/myDS</jta-data-source>
    </persistence-unit>
</persistence>

If your target Application Server does not support JTA (Tomcat), your persistence.xml looks like:

<persistence>
    <persistence-unit name="[REQUIRED_PERSISTENCE_UNIT_NAME_GOES_HERE]">
        <!--GLOBAL_JNDI_GOES_HERE-->
        <non-jta-data-source>jdbc/myDS</non-jta-data-source>
    </persistence-unit>
</persistence>

If your data source is not bound to a global JNDI (for instance, outside a Java EE container), so you would usually define JPA provider, driver, url, user and password properties. But property name depends on the JPA provider. So, for Hibernate as JPA provider, your persistence.xml file will looks like:

<persistence>
    <persistence-unit name="[REQUIRED_PERSISTENCE_UNIT_NAME_GOES_HERE]">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <class>br.com.persistence.SomeClass</class>
        <properties>
            <property name="hibernate.connection.driver_class" value="org.apache.derby.jdbc.ClientDriver"/>
            <property name="hibernate.connection.url" value="jdbc:derby://localhost:1527/EmpServDB;create=true"/>
            <property name="hibernate.connection.username" value="APP"/>
            <property name="hibernate.connection.password" value="APP"/>
        </properties>
    </persistence-unit>
</persistence>

Transaction Type Attribute

In general, in Java EE environments, a transaction-type of RESOURCE_LOCAL assumes that a non-JTA datasource will be provided. In a Java EE environment, if this element is not specified, the default is JTA. In a Java SE environment, if this element is not specified, a default of RESOURCE_LOCAL may be assumed.

  • To insure the portability of a Java SE application, it is necessary to explicitly list the managed persistence classes that are included in the persistence unit (JPA specification)

I need to create the EntityManager from the user's specified values at runtime

So use this:

Map addedOrOverridenProperties = new HashMap();

// Let's suppose we are using Hibernate as JPA provider
addedOrOverridenProperties.put("hibernate.show_sql", true);

Persistence.createEntityManagerFactory(<PERSISTENCE_UNIT_NAME_GOES_HERE>, addedOrOverridenProperties);

Merging two arrays in .NET

If you have the source arrays in an array itself you can use SelectMany:

var arrays = new[]{new[]{1, 2, 3}, new[]{4, 5, 6}};
var combined = arrays.SelectMany(a => a).ToArray();
foreach (var v in combined) Console.WriteLine(v);   

gives

1
2
3
4
5
6

Probably this is not the fastest method but might fit depending on usecase.

How to match "any character" in regular expression?

Specific Solution to the example problem:-

Try [A-Z]*123$ will match 123, AAA123, ASDFRRF123. In case you need at least a character before 123 use [A-Z]+123$.

General Solution to the question (How to match "any character" in the regular expression):

  1. If you are looking for anything including whitespace you can try [\w|\W]{min_char_to_match,}.
  2. If you are trying to match anything except whitespace you can try [\S]{min_char_to_match,}.

How can I get a Bootstrap column to span multiple rows?

The example below seemed to work. Just setting a height on the first element

<ul class="row">
    <li class="span4" style="height: 100px"><h1>1</h1></li>
    <li class="span4"><h1>2</h1></li>
    <li class="span4"><h1>3</h1></li>
    <li class="span4"><h1>4</h1></li>
    <li class="span4"><h1>5</h1></li>
    <li class="span4"><h1>6</h1></li>
    <li class="span4"><h1>7</h1></li>
    <li class="span4"><h1>8</h1></li>
</ul>

I can't help but thinking it's the wrong use of a row though.

When is a language considered a scripting language?

If it doesn't/wouldn't run on the CPU, it's a script to me. If an interpreter needs to run on the CPU below the program, then it's a script and a scripting language.

No reason to make it any more complicated than this?

Of course, in most (99%) of cases, it's clear whether a language is a scripting language. But consider that a VM can emulate the x86 instruction set, for example. Wouldn't this make the x86 bytecode a scripting language when run on a VM? What if someone was to write a compiler that would turn perl code into a native executable? In this case, I wouldn't know what to call the language itself anymore. It'd be the output that would matter, not the language.

Then again, I'm not aware of anything like this having been done, so for now I'm still comfortable calling interpreted languages scripting languages.

How can I get a list of users from active directory?

If you are new to Active Directory, I suggest you should understand how Active Directory stores data first.

Active Directory is actually a LDAP server. Objects stored in LDAP server are stored hierarchically. It's very similar to you store your files in your file system. That's why it got the name Directory server and Active Directory

The containers and objects on Active Directory can be specified by a distinguished name. The distinguished name is like this CN=SomeName,CN=SomeDirectory,DC=yourdomain,DC=com. Like a traditional relational database, you can run query against a LDAP server. It's called LDAP query.

There are a number of ways to run a LDAP query in .NET. You can use DirectorySearcher from System.DirectoryServices or SearchRequest from System.DirectoryServices.Protocol.

For your question, since you are asking to find user principal object specifically, I think the most intuitive way is to use PrincipalSearcher from System.DirectoryServices.AccountManagement. You can easily find a lot of different examples from google. Here is a sample that is doing exactly what you are asking for.

using (var context = new PrincipalContext(ContextType.Domain, "yourdomain.com"))
{
    using (var searcher = new PrincipalSearcher(new UserPrincipal(context)))
    {
        foreach (var result in searcher.FindAll())
        {
            DirectoryEntry de = result.GetUnderlyingObject() as DirectoryEntry;
            Console.WriteLine("First Name: " + de.Properties["givenName"].Value);
            Console.WriteLine("Last Name : " + de.Properties["sn"].Value);
            Console.WriteLine("SAM account name   : " + de.Properties["samAccountName"].Value);
            Console.WriteLine("User principal name: " + de.Properties["userPrincipalName"].Value);
            Console.WriteLine();
        }
    }
}
Console.ReadLine();

Note that on the AD user object, there are a number of attributes. In particular, givenName will give you the First Name and sn will give you the Last Name. About the user name. I think you meant the user logon name. Note that there are two logon names on AD user object. One is samAccountName, which is also known as pre-Windows 2000 user logon name. userPrincipalName is generally used after Windows 2000.

How to check whether java is installed on the computer

After installing Java, set the path in environmental variables and then open the command prompt and type java -version. If installed properly, it'll list the java version, jre version, etc.

You can additionally check by trying the javac command too. If it displays some data, you've your java installed with the proper path set, else it'll that javac is an invalid command.

How to Troubleshoot Intermittent SQL Timeout Errors

Like the other posters have suggested, it sounds like you have a lock contention issue. We faced a similar issue a few weeks back; however, ours was much more intermittent, and often cleared up before we could get a DBA onto the server to run sp_who2 to trace down the issue.

What we ended up doing was implement an e-mail notification if a lock exceeded a certain threshold. Once we put this in place, we were able to identify the processes that were locking, and change the isolation level to read uncommitted where appropriate to fix the issue.

Here's an article that provides an overview of how to configure this type of notification.

If locking turns out to be the issue, and if you're not already doing so, I would suggest looking into configuring row versioning-based isolation levels.

Creating SolidColorBrush from hex color value

How to get Color from Hexadecimal color code using .NET?

This I think is what you are after, hope it answers your question.

To get your code to work use Convert.ToByte instead of Convert.ToInt...

string colour = "#ffaacc";

Color.FromRgb(
Convert.ToByte(colour.Substring(1,2),16),
Convert.ToByte(colour.Substring(3,2),16),
Convert.ToByte(colour.Substring(5,2),16));

How to trigger a file download when clicking an HTML button or JavaScript

For me ading button instead of anchor text works really well.

<a href="file.doc"><button>Download!</button></a>

It might not be ok by most rules, but it looks pretty good.

How to browse localhost on Android device?

Combining a few of the answers above plus one other additional item solved the problem for me.

  1. As mentioned above, turn your firewall off [add a specific rule allowing the incoming connections to the port once you've successfully connected]
  2. Find you IP address via ipconfig as mentioned above
  3. Verify that your webserver is binding to the ip address found above and not just 127.0.0.1. Test this locally by browsing to the ip address and port. E.g. 192.168.1.113:8888. If it's not, find a solution. E.g. https://groups.google.com/forum/?fromgroups=#!topic/google-appengine-java/z4rtqkKO2hg
  4. Now test it out on your Android device. Note that I also turned off my data connection and exclusively used a wifi connection on my Android.

How to execute only one test spec with angular-cli

This is working for me in Angular 7. It is based on the --main option of the ng command. I am not sure if this option is undocumented and possibly subject to change, but it works for me. I put a line in my package.json file in scripts section. There using the --main option of with the ng test command, I specify the path to the .spec.ts file I want to execute. For example

"test 1": "ng test --main E:/WebRxAngularClient/src/app/test/shared/my-date-utils.spec.ts",

You can run the script as you run any such script. I run it in Webstorm by clicking on "test 1" in the npm section.

pip installing in global site-packages instead of virtualenv

I stumbled upon the same problem running Manjaro. I created the virtual environment using python3 -m ven venv and then activated using source venv/bin/actiave. which python and which pip both pointed towards the correct binaries in the virtualenv, however I was not able to install to the virtualenv, even when using the full path of the binaries. Turned out that when I uninstalled the python-pip package with sudo pacman -R python-pip python-reportlab (had to include reportlab to satisfy dependencies) everything started to work as expected. Not sure why, but this is probably due to a double install where the system package is taking precedence.

Open the terminal in visual studio?

Microsoft just included an integrated Windows Terminal in Visual Studio version 16.3 Preview 3. Go to Tools > Options > Preview Features, enable the Experimental VS Terminal option and restart Visual Studio.

https://devblogs.microsoft.com/visualstudio/say-hello-to-the-new-visual-studio-terminal/

iPhone hide Navigation Bar only on first page

After multiple trials here is how I got it working for what I wanted. This is what I was trying. - I have a view with a image. and I wanted to have the image go full screen. - I have a navigation controller with a tabBar too. So i need to hide that too. - Also, my main requirement was not just hiding, but having a fading effect too while showing and hiding.

This is how I got it working.

Step 1 - I have a image and user taps on that image once. I capture that gesture and push it into the new imageViewController, its in the imageViewController, I want to have full screen image.

- (void)handleSingleTap:(UIGestureRecognizer *)gestureRecognizer {  
NSLog(@"Single tap");
ImageViewController *imageViewController =
[[ImageViewController alloc] initWithNibName:@"ImageViewController" bundle:nil];

godImageViewController.imgName  = // pass the image.
godImageViewController.hidesBottomBarWhenPushed=YES;// This is important to note. 

[self.navigationController pushViewController:godImageViewController animated:YES];
// If I remove the line below, then I get this error. [CALayer retain]: message sent to deallocated instance . 
// [godImageViewController release];
} 

Step 2 - All these steps below are in the ImageViewController

Step 2.1 - In ViewDidLoad, show the navBar

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
NSLog(@"viewDidLoad");
[[self navigationController] setNavigationBarHidden:NO animated:YES];
}

Step 2.2 - In viewDidAppear, set up a timer task with delay ( I have it set for 1 sec delay). And after the delay, add fading effect. I am using alpha to use fading.

- (void)viewDidAppear:(BOOL)animated
{
NSLog(@"viewDidAppear");

myTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self     selector:@selector(fadeScreen) userInfo:nil repeats:NO];
}

- (void)fadeScreen
{
[UIView beginAnimations:nil context:nil]; // begins animation block
[UIView setAnimationDuration:1.95];        // sets animation duration
self.navigationController.navigationBar.alpha = 0.0;       // Fades the alpha channel of   this view to "0.0" over the animationDuration of "0.75" seconds
[UIView commitAnimations];   // commits the animation block.  This Block is done.
}

step 2.3 - Under viewWillAppear, add singleTap gesture to the image and make the navBar translucent.

- (void) viewWillAppear:(BOOL)animated
{

NSLog(@"viewWillAppear");


NSString *path = [[NSBundle mainBundle] pathForResource:self.imgName ofType:@"png"];

UIImage *theImage = [UIImage imageWithContentsOfFile:path];

self.imgView.image = theImage;

// add tap gestures 
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)];  
[self.imgView addGestureRecognizer:singleTap];  
[singleTap release];  

// to make the image go full screen
self.navigationController.navigationBar.translucent=YES;
}

- (void)handleTap:(UIGestureRecognizer *)gestureRecognizer 
{ 
 NSLog(@"Handle Single tap");
 [self finishedFading];
  // fade again. You can choose to skip this can add a bool, if you want to fade again when user taps again. 
 myTimer = [NSTimer scheduledTimerWithTimeInterval:5.0 target:self  selector:@selector(fadeScreen) userInfo:nil repeats:NO];
 }

Step 3 - Finally in viewWillDisappear, make sure to put all the stuff back

- (void)viewWillDisappear: (BOOL)animated 
{ 
self.hidesBottomBarWhenPushed = NO; 
self.navigationController.navigationBar.translucent=NO;

if (self.navigationController.topViewController != self)
{
    [self.navigationController setNavigationBarHidden:NO animated:animated];
}

[super viewWillDisappear:animated];
}

Linux Command History with date and time

Regarding this link you can make the first solution provided by krzyk permanent by executing:

echo 'export HISTTIMEFORMAT="%d/%m/%y %T "' >> ~/.bash_profile
source ~/.bash_profile

XMLHttpRequest Origin null is not allowed Access-Control-Allow-Origin for file:/// to file:/// (Serverless)

You can try putting 'Access-Control-Allow-Origin':'*' in response.writeHead(, {[here]}).

How can I see all the "special" characters permissible in a varchar or char field in SQL Server?

EDIT based on comments:

If you have line breaks in your result set and want to remove them, make your query this way:

SELECT
    REPLACE(REPLACE(YourColumn1,CHAR(13),' '),CHAR(10),' ')
   ,REPLACE(REPLACE(YourColumn2,CHAR(13),' '),CHAR(10),' ')
   ,REPLACE(REPLACE(YourColumn3,CHAR(13),' '),CHAR(10),' ')
   --^^^^^^^^^^^^^^^           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   --only add the above code to strings that are having line breaks, not to numbers or dates
   FROM YourTable...
   WHERE ...

This will replace all the line breaks with a space character.

Run this to "get" all characters permitted in a char() and varchar():

;WITH AllNumbers AS
(
    SELECT 1 AS Number
    UNION ALL
    SELECT Number+1
        FROM AllNumbers
        WHERE Number+1<256
)
SELECT Number AS ASCII_Value,CHAR(Number) AS ASCII_Char FROM AllNumbers
OPTION (MAXRECURSION 256)

OUTPUT:

ASCII_Value ASCII_Char
----------- ----------
1           
2           
3           
4           
5           
6           
7           
8           
9               
10          

11          
12          
13          

14          
15          
16          
17          
18          
19          
20          
21          
22          
23          
24          
25          
26          
27          
28          
29          
30          
31          
32           
33          !
34          "
35          #
36          $
37          %
38          &
39          '
40          (
41          )
42          *
43          +
44          ,
45          -
46          .
47          /
48          0
49          1
50          2
51          3
52          4
53          5
54          6
55          7
56          8
57          9
58          :
59          ;
60          <
61          =
62          >
63          ?
64          @
65          A
66          B
67          C
68          D
69          E
70          F
71          G
72          H
73          I
74          J
75          K
76          L
77          M
78          N
79          O
80          P
81          Q
82          R
83          S
84          T
85          U
86          V
87          W
88          X
89          Y
90          Z
91          [
92          \
93          ]
94          ^
95          _
96          `
97          a
98          b
99          c
100         d
101         e
102         f
103         g
104         h
105         i
106         j
107         k
108         l
109         m
110         n
111         o
112         p
113         q
114         r
115         s
116         t
117         u
118         v
119         w
120         x
121         y
122         z
123         {
124         |
125         }
126         ~
127         
128         €
129         
130         ‚
131         ƒ
132         „
133         …
134         †
135         ‡
136         ˆ
137         ‰
138         Š
139         ‹
140         Œ
141         
142         Ž
143         
144         
145         ‘
146         ’
147         “
148         ”
149         •
150         –
151         —
152         ˜
153         ™
154         š
155         ›
156         œ
157         
158         ž
159         Ÿ
160          
161         ¡
162         ¢
163         £
164         ¤
165         ¥
166         ¦
167         §
168         ¨
169         ©
170         ª
171         «
172         ¬
173         ­
174         ®
175         ¯
176         °
177         ±
178         ²
179         ³
180         ´
181         µ
182         ¶
183         ·
184         ¸
185         ¹
186         º
187         »
188         ¼
189         ½
190         ¾
191         ¿
192         À
193         Á
194         Â
195         Ã
196         Ä
197         Å
198         Æ
199         Ç
200         È
201         É
202         Ê
203         Ë
204         Ì
205         Í
206         Î
207         Ï
208         Ð
209         Ñ
210         Ò
211         Ó
212         Ô
213         Õ
214         Ö
215         ×
216         Ø
217         Ù
218         Ú
219         Û
220         Ü
221         Ý
222         Þ
223         ß
224         à
225         á
226         â
227         ã
228         ä
229         å
230         æ
231         ç
232         è
233         é
234         ê
235         ë
236         ì
237         í
238         î
239         ï
240         ð
241         ñ
242         ò
243         ó
244         ô
245         õ
246         ö
247         ÷
248         ø
249         ù
250         ú
251         û
252         ü
253         ý
254         þ
255         ÿ

(255 row(s) affected)

Inserting a string into a list without getting split into characters

Don't use list as a variable name. It's a built in that you are masking.

To insert, use the insert function of lists.

l = ['hello','world']
l.insert(0, 'foo')
print l
['foo', 'hello', 'world']

In an array of objects, fastest way to find the index of an object whose attributes match a search

I like this method because it's easy to compare to any value in the object no matter how deep it's nested.

 while(i<myArray.length && myArray[i].data.value!==value){
  i++; 
}
// i now hows the index value for the match. 
 console.log("Index ->",i );

Redis connection to 127.0.0.1:6379 failed - connect ECONNREFUSED

You have to install redis server first;

You can install redis server on mac by following step -

  $ curl -O http://download.redis.io/redis-stable.tar.gz
  $ tar xzvf redis-stable.tar.gz
  $ cd redis-stable
  $ make
  $ make test
  $ sudo make install
  $ redis-server

Good luck.

How to bind list to dataGridView?

Use a BindingList and set the DataPropertyName-Property of the column.

Try the following:

...
private void BindGrid()
{
    gvFilesOnServer.AutoGenerateColumns = false;

    //create the column programatically
    DataGridViewCell cell = new DataGridViewTextBoxCell();
    DataGridViewTextBoxColumn colFileName = new DataGridViewTextBoxColumn()
    {
        CellTemplate = cell, 
        Name = "Value",
        HeaderText = "File Name",
        DataPropertyName = "Value" // Tell the column which property of FileName it should use
     };

    gvFilesOnServer.Columns.Add(colFileName);

    var filelist = GetFileListOnWebServer().ToList();
    var filenamesList = new BindingList<FileName>(filelist); // <-- BindingList

    //Bind BindingList directly to the DataGrid, no need of BindingSource
    gvFilesOnServer.DataSource = filenamesList 
}

MySQL TEXT vs BLOB vs CLOB

TEXT is a data-type for text based input. On the other hand, you have BLOB and CLOB which are more suitable for data storage (images, etc) due to their larger capacity limits (4GB for example).

As for the difference between BLOB and CLOB, I believe CLOB has character encoding associated with it, which implies it can be suited well for very large amounts of text.

BLOB and CLOB data can take a long time to retrieve, relative to how quick data from a TEXT field can be retrieved. So, use only what you need.

How to write one new line in Bitbucket markdown?

On Github, <p> and <br/>solves the problem.

<p>I want to this to appear in a new line. Introduces extra line above

or

<br/> another way

Javascript: output current datetime in YYYY/mm/dd hh:m:sec format

Alternative to answer of @JosephMarikle If you do not want to figth against timezone UTC etc:

var dateString =
        ("0" + date.getUTCDate()).slice(-2) + "/" +
        ("0" + (date.getUTCMonth()+1)).slice(-2) + "/" +
        date.getUTCFullYear() + " " +
        //return HH:MM:SS with localtime without surprises
        date.toLocaleTimeString()
    console.log(fechaHoraActualCadena);

Reset ID autoincrement ? phpmyadmin

I have just experienced this issue in one of my MySQL db's and I looked at the phpMyAdmin answer here. However the best way I fixed it in phpMyAdmin was in the affected table, drop the id column and make a fresh/new id column (adding A-I -autoincrement-). This restored my table id correctly-simples! Hope that helps (no MySQL code needed-I hope to learn to use that but later!) anyone else with this problem.

How can bcrypt have built-in salts?

To make things even more clearer,

Registeration/Login direction ->

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

$2a$COST$BASE64

This value is stored eventually.

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

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

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

how to use ng-option to set default value of select element

An easier way to do it is to use data-ng-init like this:

<select data-ng-init="somethingHere = options[0]" data-ng-model="somethingHere" data-ng-options="option.name for option in options"></select>

The main difference here is that you would need to include data-ng-model

remove duplicates from sql union

Since you are still getting duplicate using only UNION I would check that:

  • That they are exact duplicates. I mean, if you make a

    SELECT DISTINCT * FROM (<your query>) AS subquery

    you do get fewer files?

  • That you don't have already the duplicates in the first part of the query (maybe generated by the left join). As I understand it UNION it will not add to the result set rows that are already on it, but it won't remove duplicates already present in the first data set.

Eclipse reports rendering library more recent than ADT plug-in

Am i change API version 17, 19, 21, & 23 in xml layoutside

&&

Updated Android Development Tools 23.0.7 but still can't render layout proper so am i updated Android DDMS 23.0.7 it's works perfect..!!!

Specific Time Range Query in SQL Server

I'm assuming you want all three of those as part of the selection criteria. You'll need a few statements in your where but they will be similar to the link your question contained.

SELECT *
  FROM MyTable
  WHERE [dateColumn] > '3/1/2009' AND [dateColumn] <= DATEADD(day,1,'3/31/2009') 
        --make it inclusive for a datetime type
    AND DATEPART(hh,[dateColumn]) >= 6 AND DATEPART(hh,[dateColumn]) <= 22 
        -- gets the hour of the day from the datetime
    AND DATEPART(dw,[dateColumn]) >= 3 AND DATEPART(dw,[dateColumn]) <= 5 
        -- gets the day of the week from the datetime

Hope this helps.

When to use which design pattern?

Learn them and slowly you'll be able to reconize and figure out when to use them. Start with something simple as the singleton pattern :)

if you want to create one instance of an object and just ONE. You use the singleton pattern. Let's say you're making a program with an options object. You don't want several of those, that would be silly. Singleton makes sure that there will never be more than one. Singleton pattern is simple, used a lot, and really effective.

bootstrap 4 file input doesn't show the file name

I have used following for the same:

<script type="application/javascript">
    $('input[type="file"]').change(function(e){
        var fileName = e.target.files[0].name;
        $('.custom-file-label').html(fileName);
    });
</script>

Calculating sum of repeated elements in AngularJS ng-repeat

This is a simple way to do this with ng-repeat and ng-init to aggregate all the values and extend the model with a item.total property.

<table>
<tr ng-repeat="item in items" ng-init="setTotals(item)">
                    <td>{{item.name}}</td>
                    <td>{{item.quantity}}</td>
                    <td>{{item.unitCost | number:2}}</td>
                    <td>{{item.total | number:2}}</td>
</tr>
<tr class="bg-warning">
                    <td>Totals</td>
                    <td>{{invoiceCount}}</td>
                    <td></td>                    
                    <td>{{invoiceTotal | number:2}}</td>
                </tr>
</table>

The ngInit directive calls the set total function for each item. The setTotals function in the controller calculates each item total. It also uses the invoiceCount and invoiceTotal scope variables to aggregate (sum) the quantity and total for all items.

$scope.setTotals = function(item){
        if (item){
            item.total = item.quantity * item.unitCost;
            $scope.invoiceCount += item.quantity;
            $scope.invoiceTotal += item.total;
        }
    }

for more information and demo look at this link:

http://www.ozkary.com/2015/06/angularjs-calculate-totals-using.html

Maximum on http header values?

No, HTTP does not define any limit. However most web servers do limit size of headers they accept. For example in Apache default limit is 8KB, in IIS it's 16K. Server will return 413 Entity Too Large error if headers size exceeds that limit.

Related question: How big can a user agent string get?

How can strings be concatenated?

For cases of appending to end of existing string:

string = "Sec_"
string += "C_type"
print(string)

results in

Sec_C_type

The located assembly's manifest definition does not match the assembly reference

This can also occur if you are using both AssemblyInfo.cs with the AssemblyVersion tags and your .csproj file has with a different value. By either matching the AssemblyInfo or removing the section all together the problem goes away.

Why does Java have an "unreachable statement" compiler error?

There is no definitive reason why unreachable statements must be not be allowed; other languages allow them without problems. For your specific need, this is the usual trick:

if (true) return;

It looks nonsensical, anyone who reads the code will guess that it must have been done deliberately, not a careless mistake of leaving the rest of statements unreachable.

Java has a little bit support for "conditional compilation"

http://java.sun.com/docs/books/jls/third_edition/html/statements.html#14.21

if (false) { x=3; }

does not result in a compile-time error. An optimizing compiler may realize that the statement x=3; will never be executed and may choose to omit the code for that statement from the generated class file, but the statement x=3; is not regarded as "unreachable" in the technical sense specified here.

The rationale for this differing treatment is to allow programmers to define "flag variables" such as:

static final boolean DEBUG = false;

and then write code such as:

if (DEBUG) { x=3; }

The idea is that it should be possible to change the value of DEBUG from false to true or from true to false and then compile the code correctly with no other changes to the program text.

iOS: UIButton resize according to text length

If your button was made with Interface Builder, and you're changing the title in code, you can do this:

[self.button setTitle:@"Button Title" forState:UIControlStateNormal];
[self.button sizeToFit];

How can I convert a stack trace to a string?

Code from Apache Commons Lang 3.4 (JavaDoc):

public static String getStackTrace(final Throwable throwable) {
    final StringWriter sw = new StringWriter();
    final PrintWriter pw = new PrintWriter(sw, true);
    throwable.printStackTrace(pw);
    return sw.getBuffer().toString();
}

The difference with the other answers is that it uses autoFlush on the PrintWriter.

Forbidden You don't have permission to access /wp-login.php on this server

I had a similar error, which was fixed by adding:

Options FollowSymLinks

... in the apps/[app-name]/conf/httpd-app.conf file. This is because, in my case, an .htaccess file wants to use rewrite rules, that are not allowed with FollowSymLinks AND SymLinksIfOwnerMatch turned off.

If your conf file already has a line with Options ..., you can just add FollowSymLinks to the list of options. You could end up with something like this:

Options Indexes MultiViews FollowSymLinks

Login to Microsoft SQL Server Error: 18456

Before opening, right-click and choose 'Run as Administrator'. This solved the problem for me.

How to do an INNER JOIN on multiple columns

Why can't it just use AND in the ON clause? For example:

SELECT *
FROM flights
INNER JOIN airports
   ON ((airports.code = flights.fairport)
       AND (airports.code = flights.tairport))

Password encryption at client side

I've listed a complete JavaScript for creating an MD5 at the bottom but it's really pointless without a secure connection for several reasons.

If you MD5 the password and store that MD5 in your database then the MD5 is the password. People can tell exactly what's in your database. You've essentially just made the password a longer string but it still isn't secure if that's what you're storing in your database.

If you say, "Well I'll MD5 the MD5" you're missing the point. By looking at the network traffic, or looking in your database, I can spoof your website and send it the MD5. Granted this is a lot harder than just reusing a plain text password but it's still a security hole.

Most of all though you can't salt the hash client side without sending the salt over the 'net unencrypted therefore making the salting pointless. Without a salt or with a known salt I can brute force attack the hash and figure out what the password is.

If you are going to do this kind of thing with unencrypted transmissions you need to use a public key/private key encryption technique. The client encrypts using your public key then you decrypt on your end with your private key then you MD5 the password (using a user unique salt) and store it in your database. Here's a JavaScript GPL public/private key library.

Anyway, here is the JavaScript code to create an MD5 client side (not my code):

/**
*
*  MD5 (Message-Digest Algorithm)
*  http://www.webtoolkit.info/
*
**/

var MD5 = function (string) {

    function RotateLeft(lValue, iShiftBits) {
        return (lValue<<iShiftBits) | (lValue>>>(32-iShiftBits));
    }

    function AddUnsigned(lX,lY) {
        var lX4,lY4,lX8,lY8,lResult;
        lX8 = (lX & 0x80000000);
        lY8 = (lY & 0x80000000);
        lX4 = (lX & 0x40000000);
        lY4 = (lY & 0x40000000);
        lResult = (lX & 0x3FFFFFFF)+(lY & 0x3FFFFFFF);
        if (lX4 & lY4) {
            return (lResult ^ 0x80000000 ^ lX8 ^ lY8);
        }
        if (lX4 | lY4) {
            if (lResult & 0x40000000) {
                return (lResult ^ 0xC0000000 ^ lX8 ^ lY8);
            } else {
                return (lResult ^ 0x40000000 ^ lX8 ^ lY8);
            }
        } else {
            return (lResult ^ lX8 ^ lY8);
        }
    }

    function F(x,y,z) { return (x & y) | ((~x) & z); }
    function G(x,y,z) { return (x & z) | (y & (~z)); }
    function H(x,y,z) { return (x ^ y ^ z); }
    function I(x,y,z) { return (y ^ (x | (~z))); }

    function FF(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(F(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };

    function GG(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(G(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };

    function HH(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(H(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };

    function II(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(I(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };

    function ConvertToWordArray(string) {
        var lWordCount;
        var lMessageLength = string.length;
        var lNumberOfWords_temp1=lMessageLength + 8;
        var lNumberOfWords_temp2=(lNumberOfWords_temp1-(lNumberOfWords_temp1 % 64))/64;
        var lNumberOfWords = (lNumberOfWords_temp2+1)*16;
        var lWordArray=Array(lNumberOfWords-1);
        var lBytePosition = 0;
        var lByteCount = 0;
        while ( lByteCount < lMessageLength ) {
            lWordCount = (lByteCount-(lByteCount % 4))/4;
            lBytePosition = (lByteCount % 4)*8;
            lWordArray[lWordCount] = (lWordArray[lWordCount] | (string.charCodeAt(lByteCount)<<lBytePosition));
            lByteCount++;
        }
        lWordCount = (lByteCount-(lByteCount % 4))/4;
        lBytePosition = (lByteCount % 4)*8;
        lWordArray[lWordCount] = lWordArray[lWordCount] | (0x80<<lBytePosition);
        lWordArray[lNumberOfWords-2] = lMessageLength<<3;
        lWordArray[lNumberOfWords-1] = lMessageLength>>>29;
        return lWordArray;
    };

    function WordToHex(lValue) {
        var WordToHexValue="",WordToHexValue_temp="",lByte,lCount;
        for (lCount = 0;lCount<=3;lCount++) {
            lByte = (lValue>>>(lCount*8)) & 255;
            WordToHexValue_temp = "0" + lByte.toString(16);
            WordToHexValue = WordToHexValue + WordToHexValue_temp.substr(WordToHexValue_temp.length-2,2);
        }
        return WordToHexValue;
    };

    function Utf8Encode(string) {
        string = string.replace(/\r\n/g,"\n");
        var utftext = "";

        for (var n = 0; n < string.length; n++) {

            var c = string.charCodeAt(n);

            if (c < 128) {
                utftext += String.fromCharCode(c);
            }
            else if((c > 127) && (c < 2048)) {
                utftext += String.fromCharCode((c >> 6) | 192);
                utftext += String.fromCharCode((c & 63) | 128);
            }
            else {
                utftext += String.fromCharCode((c >> 12) | 224);
                utftext += String.fromCharCode(((c >> 6) & 63) | 128);
                utftext += String.fromCharCode((c & 63) | 128);
            }

        }

        return utftext;
    };

    var x=Array();
    var k,AA,BB,CC,DD,a,b,c,d;
    var S11=7, S12=12, S13=17, S14=22;
    var S21=5, S22=9 , S23=14, S24=20;
    var S31=4, S32=11, S33=16, S34=23;
    var S41=6, S42=10, S43=15, S44=21;

    string = Utf8Encode(string);

    x = ConvertToWordArray(string);

    a = 0x67452301; b = 0xEFCDAB89; c = 0x98BADCFE; d = 0x10325476;

    for (k=0;k<x.length;k+=16) {
        AA=a; BB=b; CC=c; DD=d;
        a=FF(a,b,c,d,x[k+0], S11,0xD76AA478);
        d=FF(d,a,b,c,x[k+1], S12,0xE8C7B756);
        c=FF(c,d,a,b,x[k+2], S13,0x242070DB);
        b=FF(b,c,d,a,x[k+3], S14,0xC1BDCEEE);
        a=FF(a,b,c,d,x[k+4], S11,0xF57C0FAF);
        d=FF(d,a,b,c,x[k+5], S12,0x4787C62A);
        c=FF(c,d,a,b,x[k+6], S13,0xA8304613);
        b=FF(b,c,d,a,x[k+7], S14,0xFD469501);
        a=FF(a,b,c,d,x[k+8], S11,0x698098D8);
        d=FF(d,a,b,c,x[k+9], S12,0x8B44F7AF);
        c=FF(c,d,a,b,x[k+10],S13,0xFFFF5BB1);
        b=FF(b,c,d,a,x[k+11],S14,0x895CD7BE);
        a=FF(a,b,c,d,x[k+12],S11,0x6B901122);
        d=FF(d,a,b,c,x[k+13],S12,0xFD987193);
        c=FF(c,d,a,b,x[k+14],S13,0xA679438E);
        b=FF(b,c,d,a,x[k+15],S14,0x49B40821);
        a=GG(a,b,c,d,x[k+1], S21,0xF61E2562);
        d=GG(d,a,b,c,x[k+6], S22,0xC040B340);
        c=GG(c,d,a,b,x[k+11],S23,0x265E5A51);
        b=GG(b,c,d,a,x[k+0], S24,0xE9B6C7AA);
        a=GG(a,b,c,d,x[k+5], S21,0xD62F105D);
        d=GG(d,a,b,c,x[k+10],S22,0x2441453);
        c=GG(c,d,a,b,x[k+15],S23,0xD8A1E681);
        b=GG(b,c,d,a,x[k+4], S24,0xE7D3FBC8);
        a=GG(a,b,c,d,x[k+9], S21,0x21E1CDE6);
        d=GG(d,a,b,c,x[k+14],S22,0xC33707D6);
        c=GG(c,d,a,b,x[k+3], S23,0xF4D50D87);
        b=GG(b,c,d,a,x[k+8], S24,0x455A14ED);
        a=GG(a,b,c,d,x[k+13],S21,0xA9E3E905);
        d=GG(d,a,b,c,x[k+2], S22,0xFCEFA3F8);
        c=GG(c,d,a,b,x[k+7], S23,0x676F02D9);
        b=GG(b,c,d,a,x[k+12],S24,0x8D2A4C8A);
        a=HH(a,b,c,d,x[k+5], S31,0xFFFA3942);
        d=HH(d,a,b,c,x[k+8], S32,0x8771F681);
        c=HH(c,d,a,b,x[k+11],S33,0x6D9D6122);
        b=HH(b,c,d,a,x[k+14],S34,0xFDE5380C);
        a=HH(a,b,c,d,x[k+1], S31,0xA4BEEA44);
        d=HH(d,a,b,c,x[k+4], S32,0x4BDECFA9);
        c=HH(c,d,a,b,x[k+7], S33,0xF6BB4B60);
        b=HH(b,c,d,a,x[k+10],S34,0xBEBFBC70);
        a=HH(a,b,c,d,x[k+13],S31,0x289B7EC6);
        d=HH(d,a,b,c,x[k+0], S32,0xEAA127FA);
        c=HH(c,d,a,b,x[k+3], S33,0xD4EF3085);
        b=HH(b,c,d,a,x[k+6], S34,0x4881D05);
        a=HH(a,b,c,d,x[k+9], S31,0xD9D4D039);
        d=HH(d,a,b,c,x[k+12],S32,0xE6DB99E5);
        c=HH(c,d,a,b,x[k+15],S33,0x1FA27CF8);
        b=HH(b,c,d,a,x[k+2], S34,0xC4AC5665);
        a=II(a,b,c,d,x[k+0], S41,0xF4292244);
        d=II(d,a,b,c,x[k+7], S42,0x432AFF97);
        c=II(c,d,a,b,x[k+14],S43,0xAB9423A7);
        b=II(b,c,d,a,x[k+5], S44,0xFC93A039);
        a=II(a,b,c,d,x[k+12],S41,0x655B59C3);
        d=II(d,a,b,c,x[k+3], S42,0x8F0CCC92);
        c=II(c,d,a,b,x[k+10],S43,0xFFEFF47D);
        b=II(b,c,d,a,x[k+1], S44,0x85845DD1);
        a=II(a,b,c,d,x[k+8], S41,0x6FA87E4F);
        d=II(d,a,b,c,x[k+15],S42,0xFE2CE6E0);
        c=II(c,d,a,b,x[k+6], S43,0xA3014314);
        b=II(b,c,d,a,x[k+13],S44,0x4E0811A1);
        a=II(a,b,c,d,x[k+4], S41,0xF7537E82);
        d=II(d,a,b,c,x[k+11],S42,0xBD3AF235);
        c=II(c,d,a,b,x[k+2], S43,0x2AD7D2BB);
        b=II(b,c,d,a,x[k+9], S44,0xEB86D391);
        a=AddUnsigned(a,AA);
        b=AddUnsigned(b,BB);
        c=AddUnsigned(c,CC);
        d=AddUnsigned(d,DD);
    }

    var temp = WordToHex(a)+WordToHex(b)+WordToHex(c)+WordToHex(d);

    return temp.toLowerCase();
}

Could not find folder 'tools' inside SDK

In my case i was using Ubuntu. Where the was two directories one was /android-sdks and /android-sdk-linux. I used the second one it works for me :)

How to change MySQL data directory?

If you are using SE linux, set it to permissive mode by editing /etc/selinux/config and changing SELINUX=enforcing to SELINUX=permissive

Import txt file and having each line as a list

lines=[]
with open('file') as file:
   lines.append(file.readline())

Powershell folder size of folders without listing Subdirectories

This is similar to https://stackoverflow.com/users/3396598/kohlbrr answer, but I was trying to get the total size of a single folder and found that the script doesn't count the files in the Root of the folder you are searching. This worked for me.

$startFolder = "C:\Users";
$totalSize = 0;

$colItems = Get-ChildItem $startFolder
foreach ($i in $colItems)
{
    $subFolderItems = Get-ChildItem $i.FullName -recurse -force | Where-Object {$_.PSIsContainer -eq $false} | Measure-Object -property Length -sum | Select-Object Sum
    $totalSize = $totalSize + $subFolderItems.sum / 1MB

}

$startFolder + " | " + "{0:N2}" -f ($totalSize) + " MB"

Resize HTML5 canvas to fit window

The following solution worked for me the best. Since I'm relatively new to coding, I like to have visual confirmation that something is working the way I expect it to. I found it at the following site: http://htmlcheats.com/html/resize-the-html5-canvas-dyamically/

Here's the code:

<!DOCTYPE html>

<head>
    <meta charset="utf-8">
    <title>Resize HTML5 canvas dynamically | www.htmlcheats.com</title>
    <style>
    html, body {
      width: 100%;
      height: 100%;
      margin: 0px;
      border: 0;
      overflow: hidden; /*  Disable scrollbars */
      display: block;  /* No floating content on sides */
    }
    </style>
</head>

<body>
    <canvas id='c' style='position:absolute; left:0px; top:0px;'>
    </canvas>

    <script>
    (function() {
        var
        // Obtain a reference to the canvas element using its id.
        htmlCanvas = document.getElementById('c'),
        // Obtain a graphics context on the canvas element for drawing.
        context = htmlCanvas.getContext('2d');

       // Start listening to resize events and draw canvas.
       initialize();

       function initialize() {
           // Register an event listener to call the resizeCanvas() function 
           // each time the window is resized.
           window.addEventListener('resize', resizeCanvas, false);
           // Draw canvas border for the first time.
           resizeCanvas();
        }

        // Display custom canvas. In this case it's a blue, 5 pixel 
        // border that resizes along with the browser window.
        function redraw() {
           context.strokeStyle = 'blue';
           context.lineWidth = '5';
           context.strokeRect(0, 0, window.innerWidth, window.innerHeight);
        }

        // Runs each time the DOM window resize event fires.
        // Resets the canvas dimensions to match window,
        // then draws the new borders accordingly.
        function resizeCanvas() {
            htmlCanvas.width = window.innerWidth;
            htmlCanvas.height = window.innerHeight;
            redraw();
        }
    })();

    </script>
</body> 
</html>

The blue border shows you the edge of the resizing canvas, and is always along the edge of the window, visible on all 4 sides, which was NOT the case for some of the other above answers. Hope it helps.

Python Selenium accessing HTML source

With Selenium2Library you can use get_source()

import Selenium2Library
s = Selenium2Library.Selenium2Library()
s.open_browser("localhost:7080", "firefox")
source = s.get_source()

Unable to copy ~/.ssh/id_rsa.pub

add by user root this command : ssh user_to_acces@hostName -X

user_to_acces = user hostName = hostname machine

How to check if an integer is within a range?

There's filter_var() as well and it's the native function which checks range. It doesn't give exactly what you want (never returns true), but with "cheat" we can change it.

I don't think it's a good code as for readability, but I show it's as a possibility:

return (filter_var($someNumber, FILTER_VALIDATE_INT, ['options' => ['min_range' => $min, 'max_range' => $max]]) !== false)

Just fill $someNumber, $min and $max. filter_var with that filter returns either boolean false when number is outside range or the number itself when it's within range. The expression (!== false) makes function return true, when number is within range.

If you want to shorten it somehow, remember about type casting. If you would use != it would be false for number 0 within range -5; +5 (while it should be true). The same would happen if you would use type casting ((bool)).

// EXAMPLE OF WRONG USE, GIVES WRONG RESULTS WITH "0"
(bool)filter_var($someNumber, FILTER_VALIDATE_INT, ['options' => ['min_range' => $min, 'max_range' => $max]])
if (filter_var($someNumber, FILTER_VALIDATE_INT, ['options' => ['min_range' => $min, 'max_range' => $max]])) ...

Imagine that (from other answer):

if(in_array($userScore, range(-5, 5))) echo 'your score is correct'; else echo 'incorrect, enter again';

If user would write empty value ($userScore = '') it would be correct, as in_array is set here for default, non-strict more and that means that range creates 0 as well, and '' == 0 (non-strict), but '' !== 0 (if you would use strict mode). It's easy to miss such things and that's why I wrote a bit about that. I was learned that strict operators are default, and programmer could use non-strict only in special cases. I think it's a good lesson. Most examples here would fail in some cases because non-strict checking.

Still I like filter_var and you can use above (or below if I'd got so "upped" ;)) functions and make your own callback which you would use as FILTER_CALLBACK filter. You could return bool or even add openRange parameter. And other good point: you can use other functions, e.g. checking range of every number of array or POST/GET values. That's really powerful tool.

Why does Boolean.ToString output "True" and not "true"

This probably harks from the old VB NOT .Net days when bool.ToString produced True or False.

Submit a form using jQuery

In jQuery I would prefer the following:

$("#form-id").submit()

But then again, you really don't need jQuery to perform that task - just use regular JavaScript:

document.getElementById("form-id").submit()

How to catch segmentation fault in Linux?

Here's an example of how to do it in C.

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void segfault_sigaction(int signal, siginfo_t *si, void *arg)
{
    printf("Caught segfault at address %p\n", si->si_addr);
    exit(0);
}

int main(void)
{
    int *foo = NULL;
    struct sigaction sa;

    memset(&sa, 0, sizeof(struct sigaction));
    sigemptyset(&sa.sa_mask);
    sa.sa_sigaction = segfault_sigaction;
    sa.sa_flags   = SA_SIGINFO;

    sigaction(SIGSEGV, &sa, NULL);

    /* Cause a seg fault */
    *foo = 1;

    return 0;
}

Open mvc view in new window from controller

Yeah you can do some tricky works to simulate what you want:

1) Call your controller from a view by ajax. 2) Return your View

3) Use something like the following in the success (or maybe error! error works for me!) section of your $.ajax request:

$("#imgPrint").click(function () {
        $.ajax({
            url: ...,
            type: 'POST', dataType: 'json',
            data: $("#frm").serialize(),
            success: function (data, textStatus, jqXHR) {
                //Here it is:
                //Gets the model state
                var isValid = '@Html.Raw(Json.Encode(ViewData.ModelState.IsValid))'; 
                // checks that model is valid                    
                if (isValid == 'true') {
                    //open new tab or window - according to configs of browser
                    var w = window.open();
                    //put what controller gave in the new tab or win 
                    $(w.document.body).html(jqXHR.responseText);
                }
                $("#imgSpinner1").hide();
            },
            error: function (jqXHR, textStatus, errorThrown) {
                // And here it is for error section. 
                //Pay attention to different order of 
                //parameters of success and error sections!
                var isValid = '@Html.Raw(Json.Encode(ViewData.ModelState.IsValid))';                    
                if (isValid == 'true') {
                    var w = window.open();
                    $(w.document.body).html(jqXHR.responseText);
                }
                $("#imgSpinner1").hide();
            },
            beforeSend: function () { $("#imgSpinner1").show(); },
            complete: function () { $("#imgSpinner1").hide(); }
        });            
    });      

How do I send an HTML email?

You can find a complete and very simple java class for sending emails using Google(gmail) account here, Send email message using java application

It uses following properties

Properties props = new Properties();
  props.put("mail.smtp.auth", "true");
  props.put("mail.smtp.starttls.enable", "true");
  props.put("mail.smtp.host", "smtp.gmail.com");
  props.put("mail.smtp.port", "587");

Spring-Boot: How do I set JDBC pool properties like maximum number of connections?

Different connections pools have different configs.

For example Tomcat (default) expects:

spring.datasource.ourdb.url=...

and HikariCP will be happy with:

spring.datasource.ourdb.jdbc-url=...

We can satisfy both without boilerplate configuration:

spring.datasource.ourdb.jdbc-url=${spring.datasource.ourdb.url}

There is no property to define connection pool provider.

Take a look at source DataSourceBuilder.java

If Tomcat, HikariCP or Commons DBCP are on the classpath one of them will be selected (in that order with Tomcat first).

... so, we can easily replace connection pool provider using this maven configuration (pom.xml):

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
        <exclusions>
            <exclusion>
                <groupId>org.apache.tomcat</groupId>
                <artifactId>tomcat-jdbc</artifactId>
            </exclusion>
        </exclusions>
    </dependency>       

    <dependency>
        <groupId>com.zaxxer</groupId>
        <artifactId>HikariCP</artifactId>
    </dependency>

Verify ImageMagick installation

In Bash you can check if Imagick is an installed module:

$ php -m | grep imagick

If the response is blank it is not installed.

What are the ways to make an html link open a folder

Using file:///// just doesn't work if security settings are set to even a moderate level.

If you just want users to be able to download/view files* located on a network or share you can set up a Virtual Directory in IIS. On the Properties tab make sure the "A share located on another computer" is selected and the "Connect as..." is an account that can see the network location.

Link to the virtual directory from your webpage (e.g. http://yoursite/yourvirtualdir/) and this will open up a view of the directory in the web browser.

*You can allow write permissions on the virtual directory to allow users to add files but not tried it and assume network permissions would override this setting.

How to make PyCharm always show line numbers

v. community 5.0.4 (linux): File -> Settings -> Editor -> General -> Appearance -> now check 'Show line numbers', confirm w. OK an voila :)

How do I add a ToolTip to a control?

Just subscribe to the control's ToolTipTextNeeded event, and return e.TooltipText, much simpler.

How to use sys.exit() in Python

you didn't import sys in your code, nor did you close the () when calling the function... try:

import sys
sys.exit()

jQuery Upload Progress and AJAX file upload

Uploading files is actually possible with AJAX these days. Yes, AJAX, not some crappy AJAX wannabes like swf or java.

This example might help you out: https://webblocks.nl/tests/ajax/file-drag-drop.html

(It also includes the drag/drop interface but that's easily ignored.)

Basically what it comes down to is this:

<input id="files" type="file" />

<script>
document.getElementById('files').addEventListener('change', function(e) {
    var file = this.files[0];
    var xhr = new XMLHttpRequest();
    (xhr.upload || xhr).addEventListener('progress', function(e) {
        var done = e.position || e.loaded
        var total = e.totalSize || e.total;
        console.log('xhr progress: ' + Math.round(done/total*100) + '%');
    });
    xhr.addEventListener('load', function(e) {
        console.log('xhr upload complete', e, this.responseText);
    });
    xhr.open('post', '/URL-HERE', true);
    xhr.send(file);
});
</script>

(demo: http://jsfiddle.net/rudiedirkx/jzxmro8r/)

So basically what it comes down to is this =)

xhr.send(file);

Where file is typeof Blob: http://www.w3.org/TR/FileAPI/

Another (better IMO) way is to use FormData. This allows you to 1) name a file, like in a form and 2) send other stuff (files too), like in a form.

var fd = new FormData;
fd.append('photo1', file);
fd.append('photo2', file2);
fd.append('other_data', 'foo bar');
xhr.send(fd);

FormData makes the server code cleaner and more backward compatible (since the request now has the exact same format as normal forms).

All of it is not experimental, but very modern. Chrome 8+ and Firefox 4+ know what to do, but I don't know about any others.

This is how I handled the request (1 image per request) in PHP:

if ( isset($_FILES['file']) ) {
    $filename = basename($_FILES['file']['name']);
    $error = true;

    // Only upload if on my home win dev machine
    if ( isset($_SERVER['WINDIR']) ) {
        $path = 'uploads/'.$filename;
        $error = !move_uploaded_file($_FILES['file']['tmp_name'], $path);
    }

    $rsp = array(
        'error' => $error, // Used in JS
        'filename' => $filename,
        'filepath' => '/tests/uploads/' . $filename, // Web accessible
    );
    echo json_encode($rsp);
    exit;
}

Exit a while loop in VBS/VBA

what about changing the while loop to a do while loop

and exit using

Exit Do

Java ResultSet how to check if there are any results

Assuming you are working with a newly returned ResultSet whose cursor is pointing before the first row, an easier way to check this is to just call isBeforeFirst(). This avoids having to back-track if the data is to be read.

As explained in the documentation, this returns false if the cursor is not before the first record or if there are no rows in the ResultSet.

if (!resultSet.isBeforeFirst() ) {    
    System.out.println("No data"); 
} 

 

How can I extract embedded fonts from a PDF as valid font files?

You have several options. All these methods work on Linux as well as on Windows or Mac OS X. However, be aware that most PDFs do not include to full, complete fontface when they have a font embedded. Mostly they include just the subset of glyphs used in the document.


Using pdftops

One of the most frequently used methods to do this on *nix systems consists of the following steps:

  1. Convert the PDF to PostScript, for example by using XPDF's pdftops (on Windows: pdftops.exe helper program.
  2. Now fonts will be embedded in .pfa (PostScript) format + you can extract them using a text editor.
  3. You may need to convert the .pfa (ASCII) to a .pfb (binary) file using the t1utils and pfa2pfb.
  4. In PDFs there are never .pfm or .afm files (font metric files) embedded (because PDF viewer have internal knowledge about these). Without these, font files are hardly usable in a visually pleasing way.

Using fontforge

Another method is to use the Free font editor FontForge:

  1. Use the "Open Font" dialogbox used when opening files.
  2. Then select "Extract from PDF" in the filter section of dialog.
  3. Select the PDF file with the font to be extracted.
  4. A "Pick a font" dialogbox opens -- select here which font to open.

Check the FontForge manual. You may need to follow a few specific steps which are not necessarily straightforward in order to save the extracted font data as a file which is re-usable.


Using mupdf

Next, MuPDF. This application comes with a utility called pdfextract (on Windows: pdfextract.exe) which can extract fonts and images from PDFs. (In case you don't know about MuPDF, which still is relatively unknown and new: "MuPDF is a Free lightweight PDF viewer and toolkit written in portable C.", written by Artifex Software developers, the same company that gave us Ghostscript.)
(Update: Newer versions of MuPDF have moved the former functionality of 'pdfextract' to the command 'mutool extract'. Download it here: mupdf.com/downloads)

Note: pdfextract.exe is a command-line program. To use it, do the following:

c:\>  pdfextract.exe  c:\path\to\filename.pdf         # (on Windows)
$>    pdfextract  /path/tofilename.pdf                # (on Linux, Unix, Mac OS X)

This command will dump all of the extractable files from the pdf file referenced into the current directory. Generally you will see a variety of files: images as well as fonts. These include PNG, TTF, CFF, CID, etc. The image names will be like img-0412.png if the PDF object number of the image was 412. The fontnames will be like FGETYK+LinLibertineI-0966.ttf, if the font's PDF object number was 966.

CFF (Compact Font Format) files are a recognized format that can be converted to other formats via a variety of converters for use on different operating systems.

Again: be aware that most of these font files may have only a subset of characters and may not represent the complete typeface.

Update: (Jul 2013) Recent versions of mupdf have seen an internal reshuffling and renaming of their binaries, not just once, but several times. The main utility used to be a 'swiss knife'-alike binary called mubusy (name inspired by busybox?), which more recently was renamed to mutool. These support the sub-commands info, clean, extract, poster and show. Unfortunatey, the official documentation for these tools isn't up to date (yet). If you're on a Mac using 'MacPorts': then the utility was renamed in order to avoid name clashes with other utilities using identical names, and you may need to use mupdfextract.

To achieve the (roughly) equivalent results with mutool as its previous tool pdfextract did, just run mubusy extract ....*

So to extract fonts and images, you may need to run one of the following commandlines:

c:\>  mutool.exe extract filename.pdf      # (on Windows)
$>    mutool     extract filename.pdf      # (on Linux, Unix, Mac OS X)

Downloads are here: mupdf.com/downloads


Using gs (Ghostscript)

Then, Ghostscript can also extract fonts directly from PDFs. However, it needs the help of a special utility program named extractFonts.ps, written in PostScript language, which is available from the Ghostscript source code repository.

Now use it, you need to run both, this file extractFonts.ps and your PDF file. Ghostscript will then use the instructions from the PostScript program to extract the fonts from the PDF. It looks like this on Windows (yes, Ghostscript understands the 'forward slash', /, as a path separator also on Windows!):

gswin32c.exe                  ^
  -q -dNODISPLAY              ^
   c:/path/to/extractFonts.ps ^
  -c "(c:/path/to/your/PDFFile.pdf) extractFonts quit"

or on Linux, Unix or Mac OS X:

gs                          \
  -q -dNODISPLAY            \
   /path/to/extractFonts.ps \
  -c "(/path/to/your/PDFFile.pdf) extractFonts quit"

I've tested the Ghostscript method a few years ago. At the time it did extract *.ttf (TrueType) just fine. I don't know if other font types will also be extracted at all, and if so, in a re-usable way. I don't know if the utility does block extracting of fonts which are marked as protected.


Using pdf-parser.py

Finally, Didier Stevens' pdf-parser.py: this one is probably not as easy to use, because you need to have some know-how about internal PDF structures. pdf-parser.py is a Python script which can do a lot of other things too. It can also decompress and extract arbitrary streams from objects, and therefore it can extract embedded font files too.

But you need to know what to look for. Let's see it with an example. I have a file named big.pdf. As a first step I use the -s parameter to search the PDF for any occurrence of the keyword FontFile (pdf-parser.py does not require a case sensitive search):

pdf-parser.py -s fontfile big.pdf

In my case, for my big1.pdf, I get this result:

obj 9 0
 Type: /FontDescriptor
 Referencing: 15 0 R
  <<   
    /Ascent 728
    /CapHeight 716
    /Descent -210 
    /Flags 32
    /FontBBox [ -665 -325 2000 1006 ]
    /FontFile2 15 0 R
    /FontName /ArialMT
    /ItalicAngle 0
    /StemV 87
    /Type /FontDescriptor
    /XHeight 519
  >>   

obj 11 0 
 Type: /FontDescriptor
 Referencing: 16 0 R
  <<   
    /Ascent 728
    /CapHeight 716
    /Descent -210 
    /Flags 262176
    /FontBBox [ -628 -376 2000 1018 ]
    /FontFile2 16 0 R
    /FontName /Arial-BoldMT
    /ItalicAngle 0
    /StemV 165
    /Type /FontDescriptor
    /XHeight 519
  >>   

It tells me that there are two instances of FontFile2 inside the PDF, and these are in PDF objects no. 15 and no. 16, respectively. Object no. 15 holds the /FontFile2 for font /ArialMT, object no. 16 holds the /FontFile2 for font /Arial-BoldMT.

To show this more clearly:

pdf-parser.py -s fontfile big1.pdf | grep -i fontfile
  /FontFile2 15 0 R
  /FontFile2 16 0 R

A quick peeking into the PDF specification reveals the the keyword /FontFile2 relates to a 'stream containing a TrueType font program' (/FontFile would relate to a 'stream containing a Type 1 font program' and /FontFile3 would relate to a 'stream containing a font program whose format is specified by the Subtype entry in the stream dictionary' {hence being either a Type1C or a CIDFontType0C subtype}.)

To look specifically at PDF object no. 15 (which holds the font /ArialMT), one can use the -o 15 parameter:

pdf-parser.py -o 15 big1.pdf

 obj 15 0
  Type: 
  Referencing: 
  Contains stream
   <<
     /Length1 778552
     /Length 1581435
     /Filter /ASCIIHexDecode
   >>

This pdf-parser.py output tells us that this object contains a stream (which it will not directly display) that has a length of 1.581.435 Bytes and is encoded ( == "compressed") with ASCIIHexEncode and needs to be decoded ( == "de-compressed" or "filtered") with the help of the standard /ASCIIHexDecode filter.

To dump any stream from an object, pdf-parser.py can be called with the -d dumpname parameter. Let's do it:

pdf-parser.py -o 15 -d dumped-data.ext big1.pdf

Our extracted data dump will be in the file named dumped-data.ext. Let's see how big it is:

ls -l dumped-data.ext
  -rw-r--r--  1 kurtpfeifle  staff  1581435 Apr 11 00:29 dumped-data.ext

Oh look, it is 1.581.435 Bytes. We saw this figure in the previous command's output. Opening this file with a text editor confirms that its content is ASCII hex encoded data.

Opening the file with a font reading tool like otfinfo (this is a part of the lcdf-typetools package) will lead to some disappointment at first:

otfinfo -i dumped-data.ext
  otfinfo: dumped-data.ext: not an OpenType font (bad magic number)

OK, this is because we did not (yet) let pdf-parser.py make use of its full magic: to dump a filtered, decoded stream. For this we have to add the -f parameter:

pdf-parser.py -o 15 -f -d dumped-data-decoded.ext big1.pdf

What's the size is this new file?

ls -l dumped-data-decoded.ext
  -rw-r--r--  1 kurtpfeifle  staff  778552 Apr 11 00:39 dumped-data-decoded.ext

Oh, look: that exact number was also already stored in the PDF object no. 15 dictionary as the value for key /Length1...

What does file think it is?

file dumped-data-decoded.ext
  dumped-data-decoded.ext: TrueType font data

What does otfinfo tell us about it?

otfinfo -i dumped-data-decoded.ext
  Family:              Arial
  Subfamily:           Regular
  Full name:           Arial
  PostScript name:     ArialMT
  Version:             Version 5.10
  Unique ID:           Monotype:Arial Regular:Version 5.10 (Microsoft)
  Designer:            Monotype Type Drawing Office - Robin Nicholas, Patricia Saunders 1982
  Manufacturer:        The Monotype Corporation
  Trademark:           Arial is a trademark of The Monotype Corporation.
  Copyright:           © 2011 The Monotype Corporation. All Rights Reserved.
  License Description: You may use this font to display and print content as permitted by
                       the license terms for the product in which this font is included.
                       You may only (i) embed this font in content as permitted by the 
                       embedding restrictions included in this font; and (ii) temporarily 
                       download this font to a printer or other output device to help
                       print content.
  Vendor ID:           TMC

So Bingo!, we have a winner: pdf-parser.py did indeed extract a valid font file for us. Given the size of this file (778.552 Bytes), it looks like this font had been embedded even completely in the PDF...

We could rename it to arial-regular.ttf and install it as such and happily make use of it.


Caveats:

  • In any case you need to follow the license that applies to the font. Some font licences do not allow free use and/or distribution. Pirating fonts is like pirating any software or other copyrighted material.

  • Most PDFs which are in the wild out there do not embed the full font anyway, but only subsets. Extracting a subset of a font is only useful in a very limited scope, if at all.

Please do also read the following about Pros and (more) Cons regarding font extraction efforts:

remote: repository not found fatal: not found

This answer is a bit late but I hope it helps someone out there all the same.

In my case, it was because the repository had been moved. I recloned the project and everything became alright afterwards. A better alternative would have been to re-initialize git.

I hope this helps.. Merry coding!

How to convert C# nullable int to int

A simple conversion between v1 and v2 is not possible because v1 has a larger domain of values than v2. It's everything v1 can hold plus the null state. To convert you need to explicitly state what value in int will be used to map the null state. The simplest way to do this is the ?? operator

v2 = v1 ?? 0;  // maps null of v1 to 0

This can also be done in long form

int v2;
if (v1.HasValue) {
  v2 = v1.Value;
} else {
  v2 = 0;
}

std::queue iteration

If you need to iterate a queue ... queue isn't the container you need.
Why did you pick a queue?
Why don't you take a container that you can iterate over?


1.if you pick a queue then you say you want to wrap a container into a 'queue' interface: - front - back - push - pop - ...

if you also want to iterate, a queue has an incorrect interface. A queue is an adaptor that provides a restricted subset of the original container

2.The definition of a queue is a FIFO and by definition a FIFO is not iterable

How to make python Requests work via socks proxy

As soon as python requests will be merged with SOCKS5 pull request it will do as simple as using proxies dictionary:

#proxy
        # SOCKS5 proxy for HTTP/HTTPS
        proxies = {
            'http' : "socks5://myproxy:9191",
            'https' : "socks5://myproxy:9191"
        }

        #headers
        headers = {

        }

        url='http://icanhazip.com/'
        res = requests.get(url, headers=headers, proxies=proxies)

See SOCKS Proxy Support

Another options, in case that you cannot wait request to be ready, when you cannot use requesocks - like on GoogleAppEngine due to the lack of pwd built-in module, is to use PySocks that was mentioned above:

  1. Grab the socks.py file from the repo and put a copy in your root folder;
  2. Add import socks and import socket

At this point configure and bind the socket before using with urllib2 - in the following example:

import urllib2
import socket
import socks

socks.set_default_proxy(socks.SOCKS5, "myprivateproxy.net",port=9050)
socket.socket = socks.socksocket
res=urllib2.urlopen(url).read()

Git: "Not currently on any branch." Is there an easy way to get back on a branch, while keeping the changes?

Leaving another way here

git branch newbranch
git checkout master 
git merge newbranch 

Vertically aligning text next to a radio button

_x000D_
_x000D_
input.radio {vertical-align:middle; margin-top:8px; margin-bottom:12px;}
_x000D_
_x000D_
_x000D_

SIMPLY Adjust top and bottom as needed for PERFECT ALIGNMENT of radio button or checkbox

_x000D_
_x000D_
<input type="radio" class="radio">
_x000D_
_x000D_
_x000D_

How do I print the content of httprequest request?

If you want the content string and this string does not have parameters you can use

    String line = null;
    BufferedReader reader = request.getReader();
    while ((line = reader.readLine()) != null){
        System.out.println(line);
    }

ASP.NET MVC - Extract parameter of an URL

Update

RouteData.Values["id"] + Request.Url.Query

Will match all your examples


It is not entirely clear what you are trying to achieve. MVC passes URL parameters for you through model binding.

public class CustomerController : Controller {

  public ActionResult Edit(int id) {

    int customerId = id //the id in the URL

    return View();
  }

}


public class ProductController : Controller {

  public ActionResult Edit(int id, bool allowed) { 

    int productId = id; // the id in the URL
    bool isAllowed = allowed  // the ?allowed=true in the URL

    return View();
  }

}

Adding a route mapping to your global.asax.cs file before the default will handle the /administration/ part. Or you might want to look into MVC Areas.

routes.MapRoute(
  "Admin", // Route name
  "Administration/{controller}/{action}/{id}", // URL with parameters
  new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults

If it's the raw URL data you are after then you can use one of the various URL and Request properties available in your controller action

string url = Request.RawUrl;
string query= Request.Url.Query;
string isAllowed= Request.QueryString["allowed"];

It sounds like Request.Url.PathAndQuery could be what you want.

If you want access to the raw posted data you can use

string isAllowed = Request.Params["allowed"];
string id = RouteData.Values["id"];

Is there a "null coalescing" operator in JavaScript?

It will hopefully be available soon in Javascript, as it is in proposal phase as of Apr, 2020. You can monitor the status here for compatibility and support - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_operator

For people using Typescript, you can use the nullish coalescing operator from Typescript 3.7

From the docs -

You can think of this feature - the ?? operator - as a way to “fall back” to a default value when dealing with null or undefined. When we write code like

let x = foo ?? bar();

this is a new way to say that the value foo will be used when it’s “present”; but when it’s null or undefined, calculate bar() in its place.

Server returned HTTP response code: 401 for URL: https

401 means "Unauthorized", so there must be something with your credentials.

I think that java URL does not support the syntax you are showing. You could use an Authenticator instead.

Authenticator.setDefault(new Authenticator() {

    @Override
    protected PasswordAuthentication getPasswordAuthentication() {          
        return new PasswordAuthentication(login, password.toCharArray());
    }
});

and then simply invoking the regular url, without the credentials.

The other option is to provide the credentials in a Header:

String loginPassword = login+ ":" + password;
String encoded = new sun.misc.BASE64Encoder().encode (loginPassword.getBytes());
URLConnection conn = url.openConnection();
conn.setRequestProperty ("Authorization", "Basic " + encoded);

PS: It is not recommended to use that Base64Encoder but this is only to show a quick solution. If you want to keep that solution, look for a library that does. There are plenty.

Unable to locate an executable at "/usr/bin/java/bin/java" (-1)

JAVA_HOME is not the name of the java executable. But of the directory, java was installed in. The executable should be $JAVA_HOME/bin/java.

The which command is not helpful for you there. It will not give you the java home, but most likely this is just a wrapper or symlink to java installed in a very different directory.

How do you get current active/default Environment profile programmatically in Spring?

As already mentioned earlier. You could autowire Environment:

@Autowire
private Environment environment;

only you could do check for the needed environment much easier:

if (environment.acceptsProfiles(Profiles.of("test"))) {
    doStuffForTestEnv();
} else {
    doStuffForOtherProfiles();
}

Nested lists python

If you really need the indices you can just do what you said again for the inner list:

l = [[2,2,2],[3,3,3],[4,4,4]]
for index1 in xrange(len(l)):
    for index2 in xrange(len(l[index1])):
        print index1, index2, l[index1][index2]

But it is more pythonic to iterate through the list itself:

for inner_l in l:
    for item in inner_l:
        print item

If you really need the indices you can also use enumerate:

for index1, inner_l in enumerate(l):
    for index2, item in enumerate(inner_l):
        print index1, index2, item, l[index1][index2]

Programmatically Add CenterX/CenterY Constraints

The ObjectiveC equivalent is:

    myView.translatesAutoresizingMaskIntoConstraints = NO;

    [[myView.centerXAnchor constraintEqualToAnchor:self.view.centerXAnchor] setActive:YES];

    [[myView.centerYAnchor constraintEqualToAnchor:self.view.centerYAnchor] setActive:YES];

How to set calculation mode to manual when opening an excel file?

The best way around this would be to create an Excel called 'launcher.xlsm' in the same folder as the file you wish to open. In the 'launcher' file put the following code in the 'Workbook' object, but set the constant TargetWBName to be the name of the file you wish to open.

Private Const TargetWBName As String = "myworkbook.xlsx"

'// First, a function to tell us if the workbook is already open...
Function WorkbookOpen(WorkBookName As String) As Boolean
' returns TRUE if the workbook is open
    WorkbookOpen = False
    On Error GoTo WorkBookNotOpen
    If Len(Application.Workbooks(WorkBookName).Name) > 0 Then
        WorkbookOpen = True
        Exit Function
    End If
WorkBookNotOpen:
End Function

Private Sub Workbook_Open()
    'Check if our target workbook is open
    If WorkbookOpen(TargetWBName) = False Then
        'set calculation to manual
        Application.Calculation = xlCalculationManual
        Workbooks.Open ThisWorkbook.Path & "\" & TargetWBName
        DoEvents
        Me.Close False
    End If
End Sub

Set the constant 'TargetWBName' to be the name of the workbook that you wish to open. This code will simply switch calculation to manual, then open the file. The launcher file will then automatically close itself. *NOTE: If you do not wish to be prompted to 'Enable Content' every time you open this file (depending on your security settings) you should temporarily remove the 'me.close' to prevent it from closing itself, save the file and set it to be trusted, and then re-enable the 'me.close' call before saving again. Alternatively, you could just set the False to True after Me.Close

Setting href attribute at runtime

<style>
a:hover {
    cursor:pointer;
}
</style>

<script type="text/javascript" src="lib/jquery.js"></script>
<script type="text/javascript">
$(document).ready(function() {
    $(".link").click(function(){
        var href = $(this).attr("href").split("#");
        $(".results").text(href[1]);
    })
})
</script>



<a class="link" href="#one">one</a><br />
<a class="link" href="#two">two</a><br />
<a class="link" href="#three">three</a><br />
<a class="link" href="#four">four</a><br />
<a class="link" href="#five">five</a>


<br /><br />
<div class="results"></div>

Could someone explain this for me - for (int i = 0; i < 8; i++)

That's a loop that says, okay, for every time that i is smaller than 8, I'm going to do whatever is in the code block. Whenever i reaches 8, I'll stop. After each iteration of the loop, it increments i by 1 (i++), so that the loop will eventually stop when it meets the i < 8 (i becomes 8, so no longer is smaller than) condition.

For example, this:

for (int i = 0; i < 8; i++)
{
   Console.WriteLine(i);
}

Will output: 01234567

See how the code was executed 8 times?

In terms of arrays, this can be helpful when you don't know the size of the array, but you want to operate on every item of it. You can do:

Disclaimer: This following code will vary dependent upon language, but the principle remains the same

Array yourArray;

for (int i = 0; i < yourArray.Count; i++)
{
    Console.WriteLine(yourArray[i]);
}

The difference here is the number of execution times is entirely dependent on the size of the array, so it's dynamic.

JavaScript: how to change form action attribute value based on selection?

If you only want to change form's action, I prefer changing action on-form-submit, rather than on-input-change. It fires only once.

$('#search-form').submit(function(){
  var formAction = $("#selectsearch").val() == "people" ? "user" : "content";
  $("#search-form").attr("action", "/search/" + formAction);
}); 

How do you Hover in ReactJS? - onMouseLeave not registered during fast hover over

I personally use Style It for inline-style in React or keep my style separately in a CSS or SASS file...

But if you are really interested doing it inline, look at the library, I share some of the usages below:

In the component:

import React from 'react';
import Style from 'style-it';

class Intro extends React.Component {
  render() {
    return (
      <Style>
        {`
          .intro {
            font-size: 40px;
          }
        `}

        <p className="intro">CSS-in-JS made simple -- just Style It.</p>
      </Style>
    );
  }
}

export default Intro;

Output:

    <p class="intro _scoped-1">
      <style type="text/css">
        ._scoped-1.intro {
          font-size: 40px;
        }
      </style>

      CSS-in-JS made simple -- just Style It.
    </p>


Also you can use JavaScript variables with hover in your CSS as below :

import React from 'react';
import Style from 'style-it';

class Intro extends React.Component {
  render() {
    const fontSize = 13;

    return Style.it(`
      .intro {
        font-size: ${ fontSize }px;  // ES2015 & ES6 Template Literal string interpolation
      }
      .package {
        color: blue;
      }
      .package:hover {
        color: aqua;
      }
    `,
      <p className="intro">CSS-in-JS made simple -- just Style It.</p>
    );
  }
}

export default Intro;

And the result as below:

<p class="intro _scoped-1">
  <style type="text/css">
    ._scoped-1.intro {
      font-size: 13px;
    }
    ._scoped-1 .package {
      color: blue;
    }
    ._scoped-1 .package:hover {
      color: aqua;
    }
  </style>

  CSS-in-JS made simple -- just Style It.
</p>

What are the differences between char literals '\n' and '\r' in Java?

It depends on which Platform you work. To get the correct result use -

System.getProperty("line.separator")

How can git be installed on CENTOS 5.5?

For installing git

  1. install last epel-release

rpm -Uvh http://dl.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm

  1. Install git from repository

yum install git

What is "String args[]"? parameter in main method Java

I think it's pretty well covered by the answers above that String args[] is simply an array of string arguments you can pass to your application when you run it. For completion, I might add that it's also valid to define the method parameter passed to the main method as a variable argument (varargs) of type String:

public static void main (String... args)

In other words, the main method must accept either a String array (String args[]) or varargs (String... args) as a method argument. And there is no magic with the name args either. You might as well write arguments or even freddiefujiwara as shown in below e.gs.:

public static void main (String[] arguments)

public static void main (String[] freddiefujiwara)

How to use boost bind with a member function

Use the following instead:

boost::function<void (int)> f2( boost::bind( &myclass::fun2, this, _1 ) );

This forwards the first parameter passed to the function object to the function using place-holders - you have to tell Boost.Bind how to handle the parameters. With your expression it would try to interpret it as a member function taking no arguments.
See e.g. here or here for common usage patterns.

Note that VC8s cl.exe regularly crashes on Boost.Bind misuses - if in doubt use a test-case with gcc and you will probably get good hints like the template parameters Bind-internals were instantiated with if you read through the output.

Yarn install command error No such file or directory: 'install'

TL;DR

// Run these commands (Tested on Ubuntu 17.04 & above)
curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
sudo apt-get update && sudo apt-get install yarn

Additional Notes: Check out this official documentation/guide for installing yarn on other Ubuntu versions & to take care of additional cmdtest errors. https://yarnpkg.com/lang/en/docs/install/#debian-stable

If you don't have curl installed you can install it using sudo apt install curl

Auto increment in MongoDB to store sequence of Unique User ID

I had a similar issue, namely I was interested in generating unique numbers, which can be used as identifiers, but doesn't have to. I came up with the following solution. First to initialize the collection:

fun create(mongo: MongoTemplate) {
        mongo.db.getCollection("sequence")
                .insertOne(Document(mapOf("_id" to "globalCounter", "sequenceValue" to 0L)))
    }

An then a service that return unique (and ascending) numbers:

@Service
class IdCounter(val mongoTemplate: MongoTemplate) {

    companion object {
        const val collection = "sequence"
    }

    private val idField = "_id"
    private val idValue = "globalCounter"
    private val sequence = "sequenceValue"

    fun nextValue(): Long {
        val filter = Document(mapOf(idField to idValue))
        val update = Document("\$inc", Document(mapOf(sequence to 1)))
        val updated: Document = mongoTemplate.db.getCollection(collection).findOneAndUpdate(filter, update)!!
        return updated[sequence] as Long
    }
}

I believe that id doesn't have the weaknesses related to concurrent environment that some of the other solutions may suffer from.

character count using jquery

For length including white-space:

$("#id").val().length

For length without white-space:

$("#id").val().replace(/ /g,'').length

For removing only beginning and trailing white-space:

$.trim($("#test").val()).length

For example, the string " t e s t " would evaluate as:

//" t e s t "
$("#id").val(); 

//Example 1
$("#id").val().length; //Returns 9
//Example 2
$("#id").val().replace(/ /g,'').length; //Returns 4
//Example 3
$.trim($("#test").val()).length; //Returns 7

Here is a demo using all of them.

How can I use LEFT & RIGHT Functions in SQL to get last 3 characters?

SELECT  RIGHT(RTRIM(column), 3),
        LEFT(column, LEN(column) - 3)
FROM    table

Use RIGHT w/ RTRIM (to avoid complications with a fixed-length column), and LEFT coupled with LEN (to only grab what you need, exempt of the last 3 characters).

if there's ever a situation where the length is <= 3, then you're probably going to have to use a CASE statement so the LEFT call doesn't get greedy.

How to update std::map after using the find method?

You can update the value like following

   auto itr = m.find('ch'); 
     if (itr != m.end()){
           (*itr).second = 98;
     }

How to ping a server only once from within a batch file?

i used Mofi sample, and change some parameters, no you can do -t

@%SystemRoot%\system32\ping.exe -n -1 4.2.2.4

Remove all the elements that occur in one list from another

Performance Comparisons

Comparing the performance of all the answers mentioned here on Python 3.9.1 and Python 2.7.16.

Python 3.9.1

Answers are mentioned in order of performance:

  1. Arkku's set difference using subtraction "-" operation - (91.3 nsec per loop)

    mquadri$ python3 -m timeit -s "l1 = set([1,2,6,8]); l2 = set([2,3,5,8]);" "l1 - l2"
    5000000 loops, best of 5: 91.3 nsec per loop
    
  2. Moinuddin Quadri's using set().difference()- (133 nsec per loop)

    mquadri$ python3 -m timeit -s "l1 = set([1,2,6,8]); l2 = set([2,3,5,8]);" "l1.difference(l2)"
    2000000 loops, best of 5: 133 nsec per loop
    
  3. Moinuddin Quadri's list comprehension with set based lookup- (366 nsec per loop)

     mquadri$ python3 -m timeit -s "l1 = [1,2,6,8]; l2 = set([2,3,5,8]);" "[x for x in l1 if x not in l2]"
     1000000 loops, best of 5: 366 nsec per loop
    
  4. Donut's list comprehension on plain list - (489 nsec per loop)

     mquadri$ python3 -m timeit -s "l1 = [1,2,6,8]; l2 = [2,3,5,8];" "[x for x in l1 if x not in l2]"
     500000 loops, best of 5: 489 nsec per loop
    
  5. Daniel Pryden's generator expression with set based lookup and type-casting to list - (583 nsec per loop) : Explicitly type-casting to list to get the final object as list, as requested by OP. If generator expression is replaced with list comprehension, it'll become same as Moinuddin Quadri's list comprehension with set based lookup.

     mquadri$ mquadri$ python3 -m timeit -s "l1 = [1,2,6,8]; l2 = set([2,3,5,8]);" "list(x for x in l1 if x not in l2)"
     500000 loops, best of 5: 583 nsec per loop
    
  6. Moinuddin Quadri's using filter() and explicitly type-casting to list (need to explicitly type-cast as in Python 3.x, it returns iterator) - (681 nsec per loop)

     mquadri$ python3 -m timeit -s "l1 = [1,2,6,8]; l2 = set([2,3,5,8]);" "list(filter(lambda x: x not in l2, l1))"
     500000 loops, best of 5: 681 nsec per loop
    
  7. Akshay Hazari's using combination of functools.reduce + filter -(3.36 usec per loop) : Explicitly type-casting to list as from Python 3.x it started returned returning iterator. Also we need to import functools to use reduce in Python 3.x

     mquadri$ python3 -m timeit "from functools import reduce; l1 = [1,2,6,8]; l2 = [2,3,5,8];" "list(reduce(lambda x,y : filter(lambda z: z!=y,x) ,l1,l2))"
     100000 loops, best of 5: 3.36 usec per loop
    

Python 2.7.16

Answers are mentioned in order of performance:

  1. Arkku's set difference using subtraction "-" operation - (0.0783 usec per loop)

    mquadri$ python -m timeit -s "l1 = set([1,2,6,8]); l2 = set([2,3,5,8]);" "l1 - l2"
    10000000 loops, best of 3: 0.0783 usec per loop
    
  2. Moinuddin Quadri's using set().difference()- (0.117 usec per loop)

    mquadri$ mquadri$ python -m timeit -s "l1 = set([1,2,6,8]); l2 = set([2,3,5,8]);" "l1.difference(l2)"
    10000000 loops, best of 3: 0.117 usec per loop
    
  3. Moinuddin Quadri's list comprehension with set based lookup- (0.246 usec per loop)

     mquadri$ python -m timeit -s "l1 = [1,2,6,8]; l2 = set([2,3,5,8]);" "[x for x in l1 if x not in l2]"
     1000000 loops, best of 3: 0.246 usec per loop
    
  4. Donut's list comprehension on plain list - (0.372 usec per loop)

     mquadri$ python -m timeit -s "l1 = [1,2,6,8]; l2 = [2,3,5,8];" "[x for x in l1 if x not in l2]"
     1000000 loops, best of 3: 0.372 usec per loop
    
  5. Moinuddin Quadri's using filter() - (0.593 usec per loop)

     mquadri$ python -m timeit -s "l1 = [1,2,6,8]; l2 = set([2,3,5,8]);" "filter(lambda x: x not in l2, l1)"
     1000000 loops, best of 3: 0.593 usec per loop
    
  6. Daniel Pryden's generator expression with set based lookup and type-casting to list - (0.964 per loop) : Explicitly type-casting to list to get the final object as list, as requested by OP. If generator expression is replaced with list comprehension, it'll become same as Moinuddin Quadri's list comprehension with set based lookup.

     mquadri$ python -m timeit -s "l1 = [1,2,6,8]; l2 = set([2,3,5,8]);" "list(x for x in l1 if x not in l2)"
     1000000 loops, best of 3: 0.964 usec per loop
    
  7. Akshay Hazari's using combination of functools.reduce + filter -(2.78 usec per loop)

     mquadri$ python -m timeit "l1 = [1,2,6,8]; l2 = [2,3,5,8];" "reduce(lambda x,y : filter(lambda z: z!=y,x) ,l1,l2)"
     100000 loops, best of 3: 2.78 usec per loop
    

Making a flex item float right

You don't need floats. In fact, they're useless because floats are ignored in flexbox.

You also don't need CSS positioning.

There are several flex methods available. auto margins have been mentioned in another answer.

Here are two other options:

  • Use justify-content: space-between and the order property.
  • Use justify-content: space-between and reverse the order of the divs.

_x000D_
_x000D_
.parent {_x000D_
    display: flex;_x000D_
    justify-content: space-between;_x000D_
}_x000D_
_x000D_
.parent:first-of-type > div:last-child { order: -1; }_x000D_
_x000D_
p { background-color: #ddd;}
_x000D_
<p>Method 1: Use <code>justify-content: space-between</code> and <code>order-1</code></p>_x000D_
_x000D_
<div class="parent">_x000D_
    <div class="child" style="float:right"> Ignore parent? </div>_x000D_
    <div>another child </div>_x000D_
</div>_x000D_
_x000D_
<hr>_x000D_
_x000D_
<p>Method 2: Use <code>justify-content: space-between</code> and reverse the order of _x000D_
             divs in the mark-up</p>_x000D_
_x000D_
<div class="parent">_x000D_
    <div>another child </div>_x000D_
    <div class="child" style="float:right"> Ignore parent? </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to detect Esc Key Press in React and how to handle it

For a reusable React hook solution

import React, { useEffect } from 'react';

const useEscape = (onEscape) => {
    useEffect(() => {
        const handleEsc = (event) => {
            if (event.keyCode === 27) 
                onEscape();
        };
        window.addEventListener('keydown', handleEsc);

        return () => {
            window.removeEventListener('keydown', handleEsc);
        };
    }, []);
}

export default useEscape

Usage:

const [isOpen, setIsOpen] = useState(false);
useEscape(() => setIsOpen(false))

Closing database connections in Java

Yes. You need to close the resultset, the statement and the connection. If the connection has come from a pool, closing it actually sends it back to the pool for reuse.

You typically have to do this in a finally{} block, such that if an exception is thrown, you still get the chance to close this.

Many frameworks will look after this resource allocation/deallocation issue for you. e.g. Spring's JdbcTemplate. Apache DbUtils has methods to look after closing the resultset/statement/connection whether null or not (and catching exceptions upon closing), which may also help.

How to initialize all members of an array to the same value?

#include<stdio.h>
int main(){
int i,a[50];
for (i=0;i<50;i++){
    a[i]=5;// set value 5 to all the array index
}
for (i=0;i<50;i++)
printf("%d\n",a[i]);
   return 0;
}

It will give the o/p 5 5 5 5 5 5 ...... till the size of whole array

JavaScript DOM remove element

Using Node.removeChild() does the job for you, simply use something like this:

var leftSection = document.getElementById('left-section');
leftSection.parentNode.removeChild(leftSection);

In DOM 4, the remove method applied, but there is a poor browser support according to W3C:

The method node.remove() is implemented in the DOM 4 specification. But because of poor browser support, you should not use it.

But you can use remove method if you using jQuery...

$('#left-section').remove(); //using remove method in jQuery

Also in new frameworks like you can use conditions to remove an element, for example *ngIf in Angular and in React, rendering different views, depends on the conditions...

How do I use tools:overrideLibrary in a build.gradle file?

just changed only android:minSdkVersion="16" and it's work perfect C:\MyApp\platforms\android\CordovaLib\AndroidManifest.xml

Retrieve filename from file descriptor in C

In Windows, with GetFileInformationByHandleEx, passing FileNameInfo, you can retrieve the file name.

Using an attribute of the current class instance as a default value for method's parameter

It's written as:

def my_function(self, param_one=None): # Or custom sentinel if None is vaild
    if param_one is None:
        param_one = self.one_of_the_vars

And I think it's safe to say that will never happen in Python due to the nature that self doesn't really exist until the function starts... (you can't reference it, in its own definition - like everything else)

For example: you can't do d = {'x': 3, 'y': d['x'] * 5}

How to get Maven project version to the bash command line

This will avoid the need for grepping off log entries from the output:

mvn -Dexec.executable='echo' -Dexec.args='${project.version}' --non-recursive exec:exec -q

Selecting last element in JavaScript array

use es6 deconstruction array with the spread operator

var last = [...yourArray].pop();

note that yourArray doesn't change.

How to get input from user at runtime

`DECLARE
c_id customers.id%type := &c_id;
c_name customers.name%type;
c_add customers.address%type;
c_sal customers.salary%type;
a integer := &a`   

Here c_id customers.id%type := &c_id; statement inputs the c_id with type already defined in the table and statement a integer := &a just input integer in variable a.

Heap space out of memory

No. The heap is cleared by the garbage collector whenever it feels like it. You can ask it to run (with System.gc()) but it is not guaranteed to run.

First try increasing the memory by setting -Xmx256m

Adding value to input field with jQuery

You can do it as below.

$(this).prev('input').val("hello world");

Live Demo

What is dtype('O'), in pandas?

It means "a python object", i.e. not one of the builtin scalar types supported by numpy.

np.array([object()]).dtype
=> dtype('O')

How do I add items to an array in jQuery?

You are making an ajax request which is asynchronous therefore your console log of the list length occurs before the ajax request has completed.

The only way of achieving what you want is changing the ajax call to be synchronous. You can do this by using the .ajax and passing in asynch : false however this is not recommended as it locks the UI up until the call has returned, if it fails to return the user has to crash out of the browser.

How to install a Python module via its setup.py in Windows?

setup.py is designed to be run from the command line. You'll need to open your command prompt (In Windows 7, hold down shift while right-clicking in the directory with the setup.py file. You should be able to select "Open Command Window Here").

From the command line, you can type

python setup.py --help

...to get a list of commands. What you are looking to do is...

python setup.py install

How to find my Subversion server version number?

To find the version of the subversion REPOSITORY you can:

  1. Look to the repository on the web and on the bottom of the page it will say something like:
    "Powered by Subversion version 1.5.2 (r32768)."
  2. From the command line: <insert curl, grep oneliner here>

If not displayed, view source of the page

<svn version="1.6.13 (r1002816)" href="http://subversion.tigris.org/"> 

Now for the subversion CLIENT:

svn --version

will suffice

Test a weekly cron job

I'm using Webmin because its a productivity gem for someone who finds command line administration a bit daunting and impenetrable.

There is a "Save and Run Now" button in the "System > Scheduled Cron Jobs > Edit Cron Job" web interface.

It displays the output of the command and is exactly what I needed.

how to convert numeric to nvarchar in sql command

If the culture of the result doesn't matters or we're only talking of integer values, CONVERT or CAST will be fine.

However, if the result must match a specific culture, FORMAT might be the function to go:

DECLARE @value DECIMAL(19,4) = 1505.5698
SELECT CONVERT(NVARCHAR, @value)        -->  1505.5698
SELECT FORMAT(@value, 'N2', 'en-us')    --> 1,505.57
SELECT FORMAT(@value, 'N2', 'de-de')    --> 1.505,57

For more information on FORMAT see here.

Of course, formatting the result should be a matter of the UI layer of the software.

How do I check if an index exists on a table field in MySQL?

show index from table_name where Column_name='column_name';

Get commit list between tags in git

If your team uses descriptive commit messages (eg. "Ticket #12345 - Update dependencies") on this project, then generating changelog since the latest tag can de done like this:

git log --no-merges --pretty=format:"%s" 'old-tag^'...new-tag > /path/to/changelog.md
  • --no-merges omits the merge commits from the list
  • old-tag^ refers to the previous commit earlier than the tagged one. Useful if you want to see the tagged commit at the bottom of the list by any reason. (Single quotes needed only for iTerm on mac OS).

isset in jQuery?

You can use length:

if($("#one").length) { // 0 == false; >0 == true
    alert('yes');
}

Service vs IntentService in the Android platform

Service

  • Invoke by startService()
  • Triggered from any Thread
  • Runs on Main Thread
  • May block main (UI) thread. Always use thread within service for long task
  • Once task has done, it is our responsibility to stop service by calling stopSelf() or stopService()

IntentService

  • It performs long task usually no communication with main thread if communication is needed then it is done by Handler or BroadcastReceiver
  • Invoke via Intent
  • Triggered from Main Thread
  • Runs on the separate thread
  • Can't run the task in parallel and multiple intents are Queued on the same worker thread.

is there any PHP function for open page in new tab

You can simply use target="_blank" to open a page in a new tab

<a href="whatever.php" target="_blank">Opens On Another Tab</a>

Or you can simply use a javascript for onload

<body onload="window.open(url, '_blank');">

C# Break out of foreach loop after X number of items

int count = 0;
foreach (ListViewItem lvi in listView.Items)
{
    if(++count > 50) break;
}

How to pass value from <option><select> to form action

with jQuery :
html :

<form method="POST" name="myform" action="index.php?action=contact_agent&agent_id="  onsubmit="SetData()">
  <select name="agent" id="agent">
    <option value="1">Agent Homer</option>
    <option value="2">Agent Lenny</option>
    <option value="3">Agent Carl</option>
  </select>
</form>

jQuery :

$('form').submit(function(){
   $(this).attr('action',$(this).attr('action')+$('#agent').val());
   $(this).submit();
});

javascript :

function SetData(){
   var select = document.getElementById('agent');
   var agent_id = select.options[select.selectedIndex].value;
   document.myform.action = "index.php?action=contact_agent&agent_id="+agent_id ; # or .getAttribute('action')
   myform.submit();
}

Python: fastest way to create a list of n lists

The list comprehensions actually are implemented more efficiently than explicit looping (see the dis output for example functions) and the map way has to invoke an ophaque callable object on every iteration, which incurs considerable overhead overhead.

Regardless, [[] for _dummy in xrange(n)] is the right way to do it and none of the tiny (if existent at all) speed differences between various other ways should matter. Unless of course you spend most of your time doing this - but in that case, you should work on your algorithms instead. How often do you create these lists?

How to extract text from the PDF document?

I know that this topic is quite old, but this need is still alive. I read many documents, forum and script and build a new advanced one which supports compressed and uncompressed pdf :

https://gist.github.com/smalot/6183152

Hope it helps everone

How to undo 'git reset'?

Short answer:

git reset 'HEAD@{1}'

Long answer:

Git keeps a log of all ref updates (e.g., checkout, reset, commit, merge). You can view it by typing:

git reflog

Somewhere in this list is the commit that you lost. Let's say you just typed git reset HEAD~ and want to undo it. My reflog looks like this:

$ git reflog
3f6db14 HEAD@{0}: HEAD~: updating HEAD
d27924e HEAD@{1}: checkout: moving from d27924e0fe16776f0d0f1ee2933a0334a4787b4c
[...]

The first line says that HEAD 0 positions ago (in other words, the current position) is 3f6db14; it was obtained by resetting to HEAD~. The second line says that HEAD 1 position ago (in other words, the state before the reset) is d27924e. It was obtained by checking out a particular commit (though that's not important right now). So, to undo the reset, run git reset HEAD@{1} (or git reset d27924e).

If, on the other hand, you've run some other commands since then that update HEAD, the commit you want won't be at the top of the list, and you'll need to search through the reflog.

One final note: It may be easier to look at the reflog for the specific branch you want to un-reset, say master, rather than HEAD:

$ git reflog show master
c24138b master@{0}: merge origin/master: Fast-forward
90a2bf9 master@{1}: merge origin/master: Fast-forward
[...]

This should have less noise it in than the general HEAD reflog.

How to use curl to get a GET request exactly same as using Chrome?

Open Chrome Developer Tools, go to Network tab, make your request (you may need to check "Preserve Log" if the page refreshes). Find the request on the left, right-click, "Copy as cURL".

Apache2: 'AH01630: client denied by server configuration'

For me, all proposed solutions won't worked. This can help, if you use cgi, fastcig or fpm as proxy you have to add a location in your vhost to avoid this problem. This allows 404 to be passthrough proxy.

<Location />
require all granted
</Location>

Get parent directory of running script

I hope this will help

function get_directory(){
    $s = empty($_SERVER["HTTPS"]) ? '' : ($_SERVER["HTTPS"] == "on") ? "s" : "";
    $protocol = substr(strtolower($_SERVER["SERVER_PROTOCOL"]), 0, strpos(strtolower($_SERVER["SERVER_PROTOCOL"]), "/")) . $s;
    $port = ($_SERVER["SERVER_PORT"] == "80") ? "" : (":".$_SERVER["SERVER_PORT"]);
return $protocol . "://" . $_SERVER['SERVER_NAME'] . dirname($_SERVER['PHP_SELF']);
}
define("ROOT_PATH", get_directory()."/" );
echo ROOT_PATH;

Converting a view to Bitmap without displaying it in Android?

view.setDrawingCacheEnabled(true);
Bitmap bitmap = Bitmap.createBitmap(view.getDrawingCache());
view.setDrawingCacheEnabled(false);

How to create a custom string representation for a class object?

Ignacio Vazquez-Abrams' approved answer is quite right. It is, however, from the Python 2 generation. An update for the now-current Python 3 would be:

class MC(type):
  def __repr__(self):
    return 'Wahaha!'

class C(object, metaclass=MC):
    pass

print(C)

If you want code that runs across both Python 2 and Python 3, the six module has you covered:

from __future__ import print_function
from six import with_metaclass

class MC(type):
  def __repr__(self):
    return 'Wahaha!'

class C(with_metaclass(MC)):
    pass

print(C)

Finally, if you have one class that you want to have a custom static repr, the class-based approach above works great. But if you have several, you'd have to generate a metaclass similar to MC for each, and that can get tiresome. In that case, taking your metaprogramming one step further and creating a metaclass factory makes things a bit cleaner:

from __future__ import print_function
from six import with_metaclass

def custom_class_repr(name):
    """
    Factory that returns custom metaclass with a class ``__repr__`` that
    returns ``name``.
    """
    return type('whatever', (type,), {'__repr__': lambda self: name})

class C(with_metaclass(custom_class_repr('Wahaha!'))): pass

class D(with_metaclass(custom_class_repr('Booyah!'))): pass

class E(with_metaclass(custom_class_repr('Gotcha!'))): pass

print(C, D, E)

prints:

Wahaha! Booyah! Gotcha!

Metaprogramming isn't something you generally need everyday—but when you need it, it really hits the spot!

jQuery event handlers always execute in order they were bound - any way around this?

Updated Answer

jQuery changed the location of where events are stored in 1.8. Now you know why it is such a bad idea to mess around with internal APIs :)

The new internal API to access to events for a DOM object is available through the global jQuery object, and not tied to each instance, and it takes a DOM element as the first parameter, and a key ("events" for us) as the second parameter.

jQuery._data(<DOM element>, "events");

So here's the modified code for jQuery 1.8.

// [name] is the name of the event "click", "mouseover", .. 
// same as you'd pass it to bind()
// [fn] is the handler function
$.fn.bindFirst = function(name, fn) {
    // bind as you normally would
    // don't want to miss out on any jQuery magic
    this.on(name, fn);

    // Thanks to a comment by @Martin, adding support for
    // namespaced events too.
    this.each(function() {
        var handlers = $._data(this, 'events')[name.split('.')[0]];
        // take out the handler we just inserted from the end
        var handler = handlers.pop();
        // move it at the beginning
        handlers.splice(0, 0, handler);
    });
};

And here's a playground.


Original Answer

As @Sean has discovered, jQuery exposes all event handlers through an element's data interface. Specifically element.data('events'). Using this you could always write a simple plugin whereby you could insert any event handler at a specific position.

Here's a simple plugin that does just that to insert a handler at the beginning of the list. You can easily extend this to insert an item at any given position. It's just array manipulation. But since I haven't seen jQuery's source and don't want to miss out on any jQuery magic from happening, I normally add the handler using bind first, and then reshuffle the array.

// [name] is the name of the event "click", "mouseover", .. 
// same as you'd pass it to bind()
// [fn] is the handler function
$.fn.bindFirst = function(name, fn) {
    // bind as you normally would
    // don't want to miss out on any jQuery magic
    this.bind(name, fn);

    // Thanks to a comment by @Martin, adding support for
    // namespaced events too.
    var handlers = this.data('events')[name.split('.')[0]];
    // take out the handler we just inserted from the end
    var handler = handlers.pop();
    // move it at the beginning
    handlers.splice(0, 0, handler);
};

So for example, for this markup it would work as (example here):

<div id="me">..</div>

$("#me").click(function() { alert("1"); });
$("#me").click(function() { alert("2"); });    
$("#me").bindFirst('click', function() { alert("3"); });

$("#me").click(); // alerts - 3, then 1, then 2

However, since .data('events') is not part of their public API as far as I know, an update to jQuery could break your code if the underlying representation of attached events changes from an array to something else, for example.

Disclaimer: Since anything is possible :), here's your solution, but I would still err on the side of refactoring your existing code, as just trying to remember the order in which these items were attached can soon get out of hand as you keep adding more and more of these ordered events.

Facebook Open Graph Error - Inferred Property

In my case an unexpected error notice in the source code stopped the facebook crawler from parsing the (correctly set) og-meta tags.

I was using the HTTP_ACCEPT_LANGUAGE header, which worked fine for regular browser requests but not for the crawler, as it obviously won't use/set it.

Therefore, it was crucial for me to use the facebook's debugger feature See exactly what our scraper sees for your URL, as the error notice only could only be seen there (but not through the regular 'view source code'-browser feature).

screenshot of the facebook debugger

How to increase editor font size?

We have to be more careful when doing this. For the first time I have changed the font size of menu by mistake instead of font. First create your own scheme by going to File-->Settings-->Colors & Fonts and then you can make changes to your own scheme. The final procedure is to go to settings(File-->Settings) and then select Editor and Colors & Fontsin the left bar menu. Then select the arrow on the left side of Colors & Fonts and then select Font in the left menu bar. You will get options to change your values. Remember you can only change values to your own sheme.

Getting All Variables In Scope

As everyone noticed: you can't. But you can create a obj and assign every var you declare to that obj. That way you can easily check out your vars:

var v = {}; //put everything here

var f = function(a, b){//do something
}; v.f = f; //make's easy to debug
var a = [1,2,3];
v.a = a;
var x = 'x';
v.x = x;  //so on...

console.log(v); //it's all there

Is there a way to make AngularJS load partials in the beginning and not at when needed?

I just use eco to do the job for me. eco is supported by Sprockets by default. It's a shorthand for Embedded Coffeescript which takes a eco file and compile into a Javascript template file, and the file will be treated like any other js files you have in your assets folder.

All you need to do is to create a template with extension .jst.eco and write some html code in there, and rails will automatically compile and serve the file with the assets pipeline, and the way to access the template is really easy: JST['path/to/file']({var: value}); where path/to/file is based on the logical path, so if you have file in /assets/javascript/path/file.jst.eco, you can access the template at JST['path/file']()

To make it work with angularjs, you can pass it into the template attribute instead of templateDir, and it will start working magically!

Unsupported method: BaseConfig.getApplicationIdSuffix()

For Android Studio 3 I need to update two files to fix the error:--

1. app/build.gradle

buildscript {
    repositories {
        jcenter()
        mavenCentral()
        maven {
            url 'https://maven.google.com/'
            name 'Google'
        }
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'
    }
}

2. app/gradle/wrapper/gradle-wrapper.properties

distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip

How to use ConcurrentLinkedQueue?

No, the methods don't need to be synchronized, and you don't need to define any methods; they are already in ConcurrentLinkedQueue, just use them. ConcurrentLinkedQueue does all the locking and other operations you need internally; your producer(s) adds data into the queue, and your consumers poll for it.

First, create your queue:

Queue<YourObject> queue = new ConcurrentLinkedQueue<YourObject>();

Now, wherever you are creating your producer/consumer objects, pass in the queue so they have somewhere to put their objects (you could use a setter for this, instead, but I prefer to do this kind of thing in a constructor):

YourProducer producer = new YourProducer(queue);

and:

YourConsumer consumer = new YourConsumer(queue);

and add stuff to it in your producer:

queue.offer(myObject);

and take stuff out in your consumer (if the queue is empty, poll() will return null, so check it):

YourObject myObject = queue.poll();

For more info see the Javadoc

EDIT:

If you need to block waiting for the queue to not be empty, you probably want to use a LinkedBlockingQueue, and use the take() method. However, LinkedBlockingQueue has a maximum capacity (defaults to Integer.MAX_VALUE, which is over two billion) and thus may or may not be appropriate depending on your circumstances.

If you only have one thread putting stuff into the queue, and another thread taking stuff out of the queue, ConcurrentLinkedQueue is probably overkill. It's more for when you may have hundreds or even thousands of threads accessing the queue at the same time. Your needs will probably be met by using:

Queue<YourObject> queue = Collections.synchronizedList(new LinkedList<YourObject>());

A plus of this is that it locks on the instance (queue), so you can synchronize on queue to ensure atomicity of composite operations (as explained by Jared). You CANNOT do this with a ConcurrentLinkedQueue, as all operations are done WITHOUT locking on the instance (using java.util.concurrent.atomic variables). You will NOT need to do this if you want to block while the queue is empty, because poll() will simply return null while the queue is empty, and poll() is atomic. Check to see if poll() returns null. If it does, wait(), then try again. No need to lock.

Finally:

Honestly, I'd just use a LinkedBlockingQueue. It is still overkill for your application, but odds are it will work fine. If it isn't performant enough (PROFILE!), you can always try something else, and it means you don't have to deal with ANY synchronized stuff:

BlockingQueue<YourObject> queue = new LinkedBlockingQueue<YourObject>();

queue.put(myObject); // Blocks until queue isn't full.

YourObject myObject = queue.take(); // Blocks until queue isn't empty.

Everything else is the same. Put probably won't block, because you aren't likely to put two billion objects into the queue.

Call to undefined function curl_init().?

If you're on Windows:

Go to your php.ini file and remove the ; mark from the beginning of the following line:

;extension=php_curl.dll

After you have saved the file you must restart your HTTP server software (e.g. Apache) before this can take effect.


For Ubuntu 13.0 and above, simply use the debundled package. In a terminal type the following to install it and do not forgot to restart server.

sudo apt-get install php-curl

Or if you're using the old PHP5

sudo apt-get install php5-curl

or

sudo apt-get install php5.6-curl

Then restart apache to activate the package with

sudo service apache2 restart

Android 6.0 multiple permissions

Simple way to ask multiple permission,

https://github.com/sachinvarma/EasyPermission

How to add :

repositories {
        maven { url "https://jitpack.io" }
    }

implementation 'com.github.sachinvarma:EasyPermission:1.0.1'

How to ask permission:

 List<String> permission = new ArrayList<>();
 permission.add(EasyPermissionList.READ_EXTERNAL_STORAGE);
 permission.add(EasyPermissionList.ACCESS_FINE_LOCATION);

 new EasyPermissionInit(MainActivity.this, permission);

For more Details - >

https://github.com/sachinvarma/EasyPermission/blob/master/app/src/main/java/com/sachinvarma/easypermissionsample/MainActivity.java

It may help someone in future.

Datetime current year and month in Python

The question asks to use datetime specifically.

This is a way that uses datetime only:

year = datetime.now().year
month = datetime.now().month

syntax error, unexpected T_VARIABLE

There is no semicolon at the end of that instruction causing the error.

EDIT

Like RiverC pointed out, there is no semicolon at the end of the previous line!

require ("scripts/connect.php") 

EDIT

It seems you have no-semicolons whatsoever.

http://php.net/manual/en/language.basic-syntax.instruction-separation.php

As in C or Perl, PHP requires instructions to be terminated with a semicolon at the end of each statement.

Use RSA private key to generate public key?

Use the following commands:

  1. openssl req -x509 -nodes -days 365 -sha256 -newkey rsa:2048 -keyout mycert.pem -out mycert.pem

     Loading 'screen' into random state - done
     Generating a 2048 bit RSA private key
     .............+++
     ..................................................................................................................................................................+++
     writing new private key to 'mycert.pem'
     -----
     You are about to be asked to enter information that will be incorporated
     into your certificate request.
     What you are about to enter is what is called a Distinguished Name or a DN.
     There are quite a few fields but you can leave some blank
     For some fields there will be a default value,
     If you enter '.', the field will be left blank.
    
  2. If you check there will be a file created by the name : mycert.pem

  3. openssl rsa -in mycert.pem -pubout > mykey.txt

    writing RSA key
    
  4. If you check the same file location a new public key mykey.txt has been created.

Add a default value to a column through a migration

This is what you can do:

class Profile < ActiveRecord::Base
  before_save :set_default_val

  def set_default_val
    self.send_updates = 'val' unless self.send_updates
  end
end

EDIT: ...but apparently this is a Rookie mistake!

What is the meaning of "Failed building wheel for X" in pip install?

On Ubuntu 18.04, I ran into this issue because the apt package for wheel does not include the wheel command. I think pip tries to import the wheel python package, and if that succeeds assumes that the wheel command is also available. Ubuntu breaks that assumption.

The apt python3 code package is named python3-wheel. This is installed automatically because python3-pip recommends it.

The apt python3 wheel command package is named python-wheel-common. Installing this too fixes the "failed building wheel" errors for me.

Filter dataframe rows if value in column is in a set list of values

Use the isin method:

rpt[rpt['STK_ID'].isin(stk_list)]

SQL Server: Maximum character length of object names

Yes, it is 128, except for temp tables, whose names can only be up to 116 character long. It is perfectly explained here.

And the verification can be easily made with the following script contained in the blog post before:

DECLARE @i NVARCHAR(800)
SELECT @i = REPLICATE('A', 116)
SELECT @i = 'CREATE TABLE #'+@i+'(i int)'
PRINT @i
EXEC(@i)

Better way to sum a property value in an array

Use reduce with destructuring to sum Amount:

const traveler = [
  { description: 'Senior', Amount: 50 },
  { description: 'Senior', Amount: 50 },
  { description: 'Adult', Amount: 75 },
  { description: 'Child', Amount: 35 },
  { description: 'Infant', Amount: 25 },
];

console.log(traveler.reduce((n, {Amount}) => n + Amount, 0))

TypeError: '<=' not supported between instances of 'str' and 'int'

Change

vote = input('Enter the name of the player you wish to vote for')

to

vote = int(input('Enter the name of the player you wish to vote for'))

You are getting the input from the console as a string, so you must cast that input string to an int object in order to do numerical operations.

How to set .net Framework 4.5 version in IIS 7 application pool

There is no v4.5 shown in the gui, and typically you don't need to manually specify v4.5 since it's an in-place update. However, you can set it explicitly with appcmd like this:

appcmd set apppool /apppool.name: [App Pool Name] /managedRuntimeVersion:v4.5

Appcmd is located in %windir%\System32\inetsrv. This helped me to fix an issue with Web Deploy, where it was throwing an ERROR_APPPOOL_VERSION_MISMATCH error after upgrading from v4.0 to v4.5.

MS article on setting .Net version for App Pool

Appending output of a Batch file To log file

Use log4j in your java program instead. Then you can output to multiple media, create rolling logs, etc. and include timestamps, class names and line numbers.

Check if a key exists inside a json object

function to check undefined and null objects

function elementCheck(objarray, callback) {
        var list_undefined = "";
        async.forEachOf(objarray, function (item, key, next_key) {
            console.log("item----->", item);
            console.log("key----->", key);
            if (item == undefined || item == '') {
                list_undefined = list_undefined + "" + key + "!!  ";
                next_key(null);
            } else {
                next_key(null);
            }
        }, function (next_key) {
            callback(list_undefined);
        })
    }

here is an easy way to check whether object sent is contain undefined or null

var objarray={
"passenger_id":"59b64a2ad328b62e41f9050d",
"started_ride":"1",
"bus_id":"59b8f920e6f7b87b855393ca",
"route_id":"59b1333c36a6c342e132f5d5",
"start_location":"",
"stop_location":""
}
elementCheck(objarray,function(list){
console.log("list");
)

How to set Spring profile from system variable?

If you are using docker to deploy the spring boot app, you can set the profile using the flag e:

docker run -e "SPRING_PROFILES_ACTIVE=prod" -p 8080:8080 -t r.test.co/myapp:latest

How to measure elapsed time

Per the Android docs SystemClock.elapsedRealtime() is the recommend basis for general purpose interval timing. This is because, per the documentation, elapsedRealtime() is guaranteed to be monotonic, [...], so is the recommend basis for general purpose interval timing.

The SystemClock documentation has a nice overview of the various time methods and the applicable use cases for them.

  • SystemClock.elapsedRealtime() and SystemClock.elapsedRealtimeNanos() are the best bet for calculating general purpose elapsed time.
  • SystemClock.uptimeMillis() and System.nanoTime() are another possibility, but unlike the recommended methods, they don't include time in deep sleep. If this is your desired behavior then they are fine to use. Otherwise stick with elapsedRealtime().
  • Stay away from System.currentTimeMillis() as this will return "wall" clock time. Which is unsuitable for calculating elapsed time as the wall clock time may jump forward or backwards. Many things like NTP clients can cause wall clock time to jump and skew. This will cause elapsed time calculations based on currentTimeMillis() to not always be accurate.

When the game starts:

long startTime = SystemClock.elapsedRealtime();

When the game ends:

long endTime = SystemClock.elapsedRealtime();
long elapsedMilliSeconds = endTime - startTime;
double elapsedSeconds = elapsedMilliSeconds / 1000.0;

Also, Timer() is a best effort timer and will not always be accurate. So there will be an accumulation of timing errors over the duration of the game. To more accurately display interim time, use periodic checks to System.currentTimeMillis() as the basis of the time sent to setText(...).

Also, instead of using Timer, you might want to look into using TimerTask, this class is designed for what you want to do. The only problem is that it counts down instead of up, but that can be solved with simple subtraction.

Java decimal formatting using String.format?

Yes you can do it with String.format:

String result = String.format("%.2f", 10.0 / 3.0);
// result:  "3.33"

result = String.format("%.3f", 2.5);
// result:  "2.500"

Attach parameter to button.addTarget action in Swift

For Swift 3.0 you can use following

button.addTarget(self, action: #selector(YourViewController.YourMethodName(_:)), for:.touchUpInside)

func YourMethodName(_ sender : UIButton) {
    print(sender.tag)

}

How do I find the install time and date of Windows?

Very simple way from PowerShell:

(Get-CimInstance -Class Win32_OperatingSystem).InstallDate

Extracted from: https://www.sysadmit.com/2019/10/windows-cuando-fue-instalado.html

Getting "Could not find function xmlCheckVersion in library libxml2. Is libxml2 installed?" when installing lxml through pip

set STATICBUILD=true && pip install lxml

run this command instead, must have VS C++ compiler installed first

https://blogs.msdn.microsoft.com/pythonengineering/2016/04/11/unable-to-find-vcvarsall-bat/

It works for me with Python 3.5.2 and Windows 7

Design Patterns web based applications

I have used the struts framework and find it fairly easy to learn. When using the struts framework each page of your site will have the following items.

1) An action which is used is called every time the HTML page is refreshed. The action should populate the data in the form when the page is first loaded and handles interactions between the web UI and the business layer. If you are using the jsp page to modify a mutable java object a copy of the java object should be stored in the form rather than the original so that the original data doesn't get modified unless the user saves the page.

2) The form which is used to transfer data between the action and the jsp page. This object should consist of a set of getter and setters for attributes that need to be accessible to the jsp file. The form also has a method to validate data before it gets persisted.

3) A jsp page which is used to render the final HTML of the page. The jsp page is a hybrid of HTML and special struts tags used to access and manipulate data in the form. Although struts allows users to insert Java code into jsp files you should be very cautious about doing that because it makes your code more difficult to read. Java code inside jsp files is difficult to debug and can not be unit tested. If you find yourself writing more than 4-5 lines of java code inside a jsp file the code should probably be moved to the action.

Numpy: find index of the elements within range

This code snippet returns all the numbers in a numpy array between two values:

a = np.array([1, 3, 5, 6, 9, 10, 14, 15, 56] )
a[(a>6)*(a<10)]

It works as following: (a>6) returns a numpy array with True (1) and False (0), so does (a<10). By multiplying these two together you get an array with either a True, if both statements are True (because 1x1 = 1) or False (because 0x0 = 0 and 1x0 = 0).

The part a[...] returns all values of array a where the array between brackets returns a True statement.

Of course you can make this more complicated by saying for instance

...*(1-a<10) 

which is similar to an "and Not" statement.

Calculate mean and standard deviation from a vector of samples in C++ using Boost

//means deviation in c++

/A deviation that is a difference between an observed value and the true value of a quantity of interest (such as a population mean) is an error and a deviation that is the difference between the observed value and an estimate of the true value (such an estimate may be a sample mean) is a residual. These concepts are applicable for data at the interval and ratio levels of measurement./

#include <iostream>
#include <conio.h>
using namespace std;

/* run this program using the console pauser or add your own getch,     system("pause") or input loop */

int main(int argc, char** argv)
{
int i,cnt;
cout<<"please inter count:\t";
cin>>cnt;
float *num=new float [cnt];
float   *s=new float [cnt];
float sum=0,ave,M,M_D;

for(i=0;i<cnt;i++)
{
    cin>>num[i];
    sum+=num[i];    
}
ave=sum/cnt;
for(i=0;i<cnt;i++)
{
s[i]=ave-num[i];    
if(s[i]<0)
{
s[i]=s[i]*(-1); 
}
cout<<"\n|ave - number| = "<<s[i];  
M+=s[i];    
}
M_D=M/cnt;
cout<<"\n\n Average:             "<<ave;
cout<<"\n M.D(Mean Deviation): "<<M_D;
getch();
return 0;

}

What's the difference between using CGFloat and float?

Objective-C

From the Foundation source code, in CoreGraphics' CGBase.h:

/* Definition of `CGFLOAT_TYPE', `CGFLOAT_IS_DOUBLE', `CGFLOAT_MIN', and
   `CGFLOAT_MAX'. */

#if defined(__LP64__) && __LP64__
# define CGFLOAT_TYPE double
# define CGFLOAT_IS_DOUBLE 1
# define CGFLOAT_MIN DBL_MIN
# define CGFLOAT_MAX DBL_MAX
#else
# define CGFLOAT_TYPE float
# define CGFLOAT_IS_DOUBLE 0
# define CGFLOAT_MIN FLT_MIN
# define CGFLOAT_MAX FLT_MAX
#endif

/* Definition of the `CGFloat' type and `CGFLOAT_DEFINED'. */

typedef CGFLOAT_TYPE CGFloat;
#define CGFLOAT_DEFINED 1

Copyright (c) 2000-2011 Apple Inc.

This is essentially doing:

#if defined(__LP64__) && __LP64__
typedef double CGFloat;
#else
typedef float CGFloat;
#endif

Where __LP64__ indicates whether the current architecture* is 64-bit.

Note that 32-bit systems can still use the 64-bit double, it just takes more processor time, so CoreGraphics does this for optimization purposes, not for compatibility. If you aren't concerned about performance but are concerned about accuracy, simply use double.

Swift

In Swift, CGFloat is a struct wrapper around either Float on 32-bit architectures or Double on 64-bit ones (You can detect this at run- or compile-time with CGFloat.NativeType) and cgFloat.native.

From the CoreGraphics source code, in CGFloat.swift.gyb:

public struct CGFloat {
#if arch(i386) || arch(arm)
  /// The native type used to store the CGFloat, which is Float on
  /// 32-bit architectures and Double on 64-bit architectures.
  public typealias NativeType = Float
#elseif arch(x86_64) || arch(arm64)
  /// The native type used to store the CGFloat, which is Float on
  /// 32-bit architectures and Double on 64-bit architectures.
  public typealias NativeType = Double
#endif

*Specifically, longs and pointers, hence the LP. See also: http://www.unix.org/version2/whatsnew/lp64_wp.html

Pandas sort by group aggregate and column

Here's a more concise approach...

df['a_bsum'] = df.groupby('A')['B'].transform(sum)
df.sort(['a_bsum','C'], ascending=[True, False]).drop('a_bsum', axis=1)

The first line adds a column to the data frame with the groupwise sum. The second line performs the sort and then removes the extra column.

Result:

    A       B           C
5   baz     -2.301539   True
2   baz     -0.528172   False
1   bar     -0.611756   True
4   bar      0.865408   False
3   foo     -1.072969   True
0   foo      1.624345   False

NOTE: sort is deprecated, use sort_values instead

How to get the unique ID of an object which overrides hashCode()?

If it's a class that you can modify, you could declare a class variable static java.util.concurrent.atomic.AtomicInteger nextInstanceId. (You'll have to give it an initial value in the obvious way.) Then declare an instance variable int instanceId = nextInstanceId.getAndIncrement().