Programs & Examples On #Ferret

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

Regex is not on the list of search features, and it was on (more or less, as Better message search functionality (i.e. Wildcard and partial word search)) the list of pre-canned feature requests, so the answer is "you cannot do this via the Gmail web UI" :-(

There are no current Labs features which offer this. SIEVE filters would be another way to do this, that too was not supported, there seems to no longer be any definitive statement on SIEVE support in the Gmail help.

Updated for link rot The pre-canned list of feature requests was, er canned, the original is on archive.org dated 2012, now you just get redirected to a dumbed down page telling you how to give feedback. Lack of SIEVE support was covered in answer 78761 Does Gmail support all IMAP features?, since some time in 2015 that answer silently redirects to the answer about IMAP client configuration, archive.org has a copy dated 2014.

With the current search facility brackets of any form () {} [] are used for grouping, they have no observable effect if there's just one term within. Using (aaa|bbb) and [aaa|bbb] are equivalent and will both find words aaa or bbb. Most other punctuation characters, including \, are treated as a space or a word-separator, + - : and " do have special meaning though, see the help.

As of 2016, only the form "{term1 term2}" is documented for this, and is equivalent to the search "term1 OR term2".

You can do regex searches on your mailbox (within limits) programmatically via Google docs: http://www.labnol.org/internet/advanced-gmail-search/21623/ has source showing how it can be done (copy the document, then Tools > Script Editor to get the complete source).

You could also do this via IMAP as described here: Python IMAP search for partial subject and script something to move messages to different folder. The IMAP SEARCH verb only supports substrings, not regex (Gmail search is further limited to complete words, not substrings), further processing of the matches to apply a regex would be needed.

For completeness, one last workaround is: Gmail supports plus addressing, if you can change the destination address to [email protected] it will still be sent to your mailbox where you can filter by recipient address. Make sure to filter using the full email address to:[email protected]. This is of course more or less the same thing as setting up a dedicated Gmail address for this purpose :-)

string in namespace std does not name a type

Nouns.h doesn't include <string>, but it needs to. You need to add

#include <string>

at the top of that file, otherwise the compiler doesn't know what std::string is when it is encountered for the first time.

What use is find_package() if you need to specify CMAKE_MODULE_PATH anyway?

How is this usually done? Should I copy the cmake/ directory of SomeLib into my project and set the CMAKE_MODULE_PATH relatively?

If you don't trust CMake to have that module, then - yes, do that - sort of: Copy the find_SomeLib.cmake and its dependencies into your cmake/ directory. That's what I do as a fallback. It's an ugly solution though.

Note that the FindFoo.cmake modules are each a sort of a bridge between platform-dependence and platform-independence - they look in various platform-specific places to obtain paths in variables whose names is platform-independent.

How to get all groups that a user is a member of?

(GET-ADUSER –Identity USERNAME –Properties MemberOf | Select-Object MemberOf).MemberOf

How can I determine browser window size on server side C#

You can use Javascript to get the viewport width and height. Then pass the values back via a hidden form input or ajax.

At its simplest

var width = $(window).width();
var height = $(window).height();

Complete method using hidden form inputs

Assuming you have: JQuery framework.

First, add these hidden form inputs to store the width and height until postback.

<asp:HiddenField ID="width" runat="server" />
<asp:HiddenField ID="height" runat="server" />

Next we want to get the window (viewport) width and height. JQuery has two methods for this, aptly named width() and height().

Add the following code to your .aspx file within the head element.

<script type="text/javascript">
$(document).ready(function() {

    $("#width").val() = $(window).width();
    $("#height").val() = $(window).height();    

});
</script>

Result

This will result in the width and height of the browser window being available on postback. Just access the hidden form inputs like this:

var TheBrowserWidth = width.Value;
var TheBrowserHeight = height.Value;

This method provides the height and width upon postback, but not on the intial page load.

Note on UpdatePanels: If you are posting back via UpdatePanels, I believe the hidden inputs need to be within the UpdatePanel.

Alternatively you can post back the values via an ajax call. This is useful if you want to react to window resizing.

Update for jquery 3.1.1

I had to change the JavaScript to:

$("#width").val($(window).width());
$("#height").val($(window).height());

Get a list of all threads currently running in Java

In Groovy you can call private methods

// Get a snapshot of the list of all threads 
Thread[] threads = Thread.getThreads()

In Java, you can invoke that method using reflection provided that security manager allows it.

Drop all duplicate rows across multiple columns in Python Pandas

Just want to add to Ben's answer on drop_duplicates:

keep : {‘first’, ‘last’, False}, default ‘first’

  • first : Drop duplicates except for the first occurrence.

  • last : Drop duplicates except for the last occurrence.

  • False : Drop all duplicates.

So setting keep to False will give you desired answer.

DataFrame.drop_duplicates(*args, **kwargs) Return DataFrame with duplicate rows removed, optionally only considering certain columns

Parameters: subset : column label or sequence of labels, optional Only consider certain columns for identifying duplicates, by default use all of the columns keep : {‘first’, ‘last’, False}, default ‘first’ first : Drop duplicates except for the first occurrence. last : Drop duplicates except for the last occurrence. False : Drop all duplicates. take_last : deprecated inplace : boolean, default False Whether to drop duplicates in place or to return a copy cols : kwargs only argument of subset [deprecated] Returns: deduplicated : DataFrame

How do I programmatically get the GUID of an application in .NET 2.0

Try the following code. The value you are looking for is stored on a GuidAttribute instance attached to the Assembly

using System.Runtime.InteropServices;

static void Main(string[] args)
{
    var assembly = typeof(Program).Assembly;
    var attribute = (GuidAttribute)assembly.GetCustomAttributes(typeof(GuidAttribute),true)[0];
    var id = attribute.Value;
    Console.WriteLine(id);
}

JSON Array iteration in Android/Java

I think this code is short and clear:

int id;
String name;
JSONArray array = new JSONArray(string_of_json_array);
for (int i = 0; i < array.length(); i++) {
    JSONObject row = array.getJSONObject(i);
    id = row.getInt("id");
    name = row.getString("name");
}

Is that what you were looking for?

Why can't I use a list as a dict key in python?

Here's an answer http://wiki.python.org/moin/DictionaryKeys

What would go wrong if you tried to use lists as keys, with the hash as, say, their memory location?

Looking up different lists with the same contents would produce different results, even though comparing lists with the same contents would indicate them as equivalent.

What about Using a list literal in a dictionary lookup?

How do I restore a dump file from mysqldump?

mysql -u username -p -h localhost DATA-BASE-NAME < data.sql

look here - step 3: this way you dont need the USE statement

How can I hide the Android keyboard using JavaScript?

For anyone using vuejs or jquery with cordova, use document.activeElement.blur() ;

hideKeyboard() {
    document.activeElement.blur();
}

..and from my text box, I just call that function:

For VueJS : v-on:keyup.enter="hideKeyboard" Pressing the enter button closes the android keyboard.

for jQuery:

$('element').keypress(function(e) {
  if(e.keyCode===13) document.activeElement.blur();
}

How to specify a local file within html using the file: scheme?

The file: URL scheme refers to a file on the client machine. There is no hostname in the file: scheme; you just provide the path of the file. So, the file on your local machine would be file:///~User/2ndFile.html. Notice the three slashes; the hostname part of the URL is empty, so the slash at the beginning of the path immediately follows the double slash at the beginning of the URL. You will also need to expand the user's path; ~ does no expand in a file: URL. So you would need file:///home/User/2ndFile.html (on most Unixes), file:///Users/User/2ndFile.html (on Mac OS X), or file:///C:/Users/User/2ndFile.html (on Windows).

Many browsers, for security reasons, do not allow linking from a file that is loaded from a server to a local file. So, you may not be able to do this from a page loaded via HTTP; you may only be able to link to file: URLs from other local pages.

Base64 decode snippet in C++

Here is one written by me which uses unions and bit fields for maximum efficiency and readibility.

const char PADDING_CHAR = '=';
const char* ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
const uint8_t DECODED_ALPHBET[128]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,62,0,0,0,63,52,53,54,55,56,57,58,59,60,61,0,0,0,0,0,0,0,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,0,0,0,0,0,0,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,0,0,0,0,0};

/**
 * Given a string, this function will encode it in 64b (with padding)
 */
std::string encodeBase64(const std::string& binaryText)
{
    std::string encoded((binaryText.size()/3 + (binaryText.size()%3 > 0)) << 2, PADDING_CHAR);

    const char* bytes = binaryText.data();
    union
    {
        uint32_t temp = 0;
        struct
        {
            uint32_t first : 6, second : 6, third : 6, fourth : 6;
        } tempBytes;
    };
    std::string::iterator currEncoding = encoded.begin();

    for(uint32_t i = 0, lim = binaryText.size() / 3; i < lim; ++i, bytes+=3)
    {
        temp = bytes[0] << 16 | bytes[1] << 8 | bytes[2];
        (*currEncoding++) = ALPHABET[tempBytes.fourth];
        (*currEncoding++) = ALPHABET[tempBytes.third];
        (*currEncoding++) = ALPHABET[tempBytes.second];
        (*currEncoding++) = ALPHABET[tempBytes.first];
    }

    switch(binaryText.size() % 3)
    {
    case 1:
        temp = bytes[0] << 16;
        (*currEncoding++) = ALPHABET[tempBytes.fourth];
        (*currEncoding++) = ALPHABET[tempBytes.third];
        break;
    case 2:
        temp = bytes[0] << 16 | bytes[1] << 8;
        (*currEncoding++) = ALPHABET[tempBytes.fourth];
        (*currEncoding++) = ALPHABET[tempBytes.third];
        (*currEncoding++) = ALPHABET[tempBytes.second];
        break;
    }

    return encoded;
}

/**
 * Given a 64b padding-encoded string, this function will decode it.
 */
std::string decodeBase64(const std::string& base64Text)
{
    if( base64Text.empty() )
        return "";

    assert((base64Text.size()&3) == 0 && "The base64 text to be decoded must have a length devisible by 4!");

    uint32_t numPadding =  (*std::prev(base64Text.end(),1) == PADDING_CHAR) + (*std::prev(base64Text.end(),2) == PADDING_CHAR);

    std::string decoded((base64Text.size()*3>>2) - numPadding, '.');

    union
    {
        uint32_t temp;
        char tempBytes[4];
    };
    const uint8_t* bytes = reinterpret_cast<const uint8_t*>(base64Text.data());

    std::string::iterator currDecoding = decoded.begin();

    for(uint32_t i = 0, lim = (base64Text.size() >> 2) - (numPadding!=0); i < lim; ++i, bytes+=4)
    {
        temp = DECODED_ALPHBET[bytes[0]] << 18 | DECODED_ALPHBET[bytes[1]] << 12 | DECODED_ALPHBET[bytes[2]] << 6 | DECODED_ALPHBET[bytes[3]];
        (*currDecoding++) = tempBytes[2];
        (*currDecoding++) = tempBytes[1];
        (*currDecoding++) = tempBytes[0];
    }

    switch (numPadding)
    {
    case 2:
        temp = DECODED_ALPHBET[bytes[0]] << 18 | DECODED_ALPHBET[bytes[1]] << 12;
        (*currDecoding++) = tempBytes[2];
        break;
    
    case 1:
        temp = DECODED_ALPHBET[bytes[0]] << 18 | DECODED_ALPHBET[bytes[1]] << 12 | DECODED_ALPHBET[bytes[2]] << 6;
        (*currDecoding++) = tempBytes[2];
        (*currDecoding++) = tempBytes[1];
        break;
    }

    return decoded;
}

Check if string contains only letters in javascript

You need

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

Currently, you are matching a single character at the start of the input. If your goal is to match letter characters (one or more) from start to finish, then you need to repeat the a-z character match (using +) and specify that you want to match all the way to the end (via $)

What is the reason for having '//' in Python?

To complement Alex's response, I would add that starting from Python 2.2.0a2, from __future__ import division is a convenient alternative to using lots of float(…)/…. All divisions perform float divisions, except those with //. This works with all versions from 2.2.0a2 on.

Adding a simple UIAlertView

Simple alert with array data:

NSString *name = [[YourArray objectAtIndex:indexPath.row ]valueForKey:@"Name"];

NSString *msg = [[YourArray objectAtIndex:indexPath.row ]valueForKey:@"message"];

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:name
                                                message:msg
                                               delegate:self
                                      cancelButtonTitle:@"OK"
                                      otherButtonTitles:nil];
[alert show];

How to reset a timer in C#?

For a Timer (System.Windows.Forms.Timer).

The .Stop, then .Start methods worked as a reset.

Sending JWT token in the headers with Postman

Here is an image if it helps :)

Postman

Update:

The postman team added "Bearer token" to the "authorization tab": Updated postman

Unix - copy contents of one directory to another

Try this:

cp Folder1/* Folder2/

Make the current Git branch a master branch

From what I understand, you can branch the current branch into an existing branch. In essence, this will overwrite master with whatever you have in the current branch:

git branch -f master HEAD

Once you've done that, you can normally push your local master branch, possibly requiring the force parameter here as well:

git push -f origin master

No merges, no long commands. Simply branch and push— but, yes, this will rewrite history of the master branch, so if you work in a team you have got to know what you're doing.




Alternatively, I found that you can push any branch to the any remote branch, so:

# This will force push the current branch to the remote master
git push -f origin HEAD:master

# Switch current branch to master
git checkout master

# Reset the local master branch to what's on the remote
git reset --hard origin/master

How to fix SSL certificate error when running Npm on Windows?

set the below property:

"npm config set strict-ssl false"

Passing bash variable to jq

I resolved this issue by escaping the inner double quotes

projectID=$(cat file.json | jq -r ".resource[] | select(.username==\"$EMAILID\") | .id")

JavaScript click event listener on class

You can use the code below:

document.body.addEventListener('click', function (evt) {
    if (evt.target.className === 'databox') {
        alert(this)
    }
}, false);

Adding author name in Eclipse automatically to existing files

To old files I don't know how to do it... I think you will need a script to go thru all files and add the header.

To change the new ones you can do this.

Go to Eclipse menu bar

  1. Window menu.
  2. Preferences
  3. search for Templates
  4. go to Code templates
  5. click on +code
  6. Click on New Java files
  7. Click Edit
  8. add

/**
${user}
*/

And it's done every new File will have your name on it !

Correctly determine if date string is a valid date in that format

I have this thing that, even with PHP, I like to find functional solutions. So, for example, the answer given by @migli is really a good one, highly flexible and elegant.

But it has a problem: what if you need to validate a lot of DateTime strings with the same format? You would have to repeat the format all over the place, what goes against the DRY principle. We could put the format in a constant, but still, we would have to pass the constant as an argument to every function call.

But fear no more! We can use currying to our rescue! PHP doesn't make this task pleasant, but it's still possible to implement currying with PHP:

<?php
function validateDateTime($format)
{
    return function($dateStr) use ($format) {
        $date = DateTime::createFromFormat($format, $dateStr);
        return $date && $date->format($format) === $dateStr;
    };
}

So, what we just did? Basically we wrapped the function body in an anonymous and returned such function instead. We can call the validation function like this:

validateDateTime('Y-m-d H:i:s')('2017-02-06 17:07:11'); // true

Yeah, not a big difference... but the real power comes from the partially applied function, made possible by currying:

// Get a partially applied function
$validate = validateDateTime('Y-m-d H:i:s');

// Now you can use it everywhere, without repeating the format!
$validate('2017-02-06 17:09:31'); // true
$validate('1999-03-31 07:07:07'); // true
$validate('13-2-4 3:2:45'); // false

Functional programming FTW!

"Could not find a version that satisfies the requirement opencv-python"

Install it by using this command:

pip install opencv-contrib-python

Where does SVN client store user authentication data?

Read SVNBook | Client Credentials.

With modern SVN you can just run svn auth to display the list of cached credentials. Don't forget to make sure that you run up-to-date SVN client version because svn auth was introduced in version 1.9. The last line will specify the path to credential store which by default is %APPDATA%\Subversion\auth on Windows and ~/.subversion/auth/ on Unix-like systems.

PS C:\Users\MyUser> svn auth
------------------------------------------------------------------------
Credential kind: svn.simple
Authentication realm: <https://svn.example.local:443> VisualSVN Server
Password cache: wincrypt
Password: [not shown]
Username: user

Credentials cache in 'C:\Users\MyUser\AppData\Roaming\Subversion' contains 5 credentials

FutureWarning: elementwise comparison failed; returning scalar, but in the future will perform elementwise comparison

If your arrays aren't too big or you don't have too many of them, you might be able to get away with forcing the left hand side of == to be a string:

myRows = df[str(df['Unnamed: 5']) == 'Peter'].index.tolist()

But this is ~1.5 times slower if df['Unnamed: 5'] is a string, 25-30 times slower if df['Unnamed: 5'] is a small numpy array (length = 10), and 150-160 times slower if it's a numpy array with length 100 (times averaged over 500 trials).

a = linspace(0, 5, 10)
b = linspace(0, 50, 100)
n = 500
string1 = 'Peter'
string2 = 'blargh'
times_a = zeros(n)
times_str_a = zeros(n)
times_s = zeros(n)
times_str_s = zeros(n)
times_b = zeros(n)
times_str_b = zeros(n)
for i in range(n):
    t0 = time.time()
    tmp1 = a == string1
    t1 = time.time()
    tmp2 = str(a) == string1
    t2 = time.time()
    tmp3 = string2 == string1
    t3 = time.time()
    tmp4 = str(string2) == string1
    t4 = time.time()
    tmp5 = b == string1
    t5 = time.time()
    tmp6 = str(b) == string1
    t6 = time.time()
    times_a[i] = t1 - t0
    times_str_a[i] = t2 - t1
    times_s[i] = t3 - t2
    times_str_s[i] = t4 - t3
    times_b[i] = t5 - t4
    times_str_b[i] = t6 - t5
print('Small array:')
print('Time to compare without str conversion: {} s. With str conversion: {} s'.format(mean(times_a), mean(times_str_a)))
print('Ratio of time with/without string conversion: {}'.format(mean(times_str_a)/mean(times_a)))

print('\nBig array')
print('Time to compare without str conversion: {} s. With str conversion: {} s'.format(mean(times_b), mean(times_str_b)))
print(mean(times_str_b)/mean(times_b))

print('\nString')
print('Time to compare without str conversion: {} s. With str conversion: {} s'.format(mean(times_s), mean(times_str_s)))
print('Ratio of time with/without string conversion: {}'.format(mean(times_str_s)/mean(times_s)))

Result:

Small array:
Time to compare without str conversion: 6.58464431763e-06 s. With str conversion: 0.000173756599426 s
Ratio of time with/without string conversion: 26.3881526541

Big array
Time to compare without str conversion: 5.44309616089e-06 s. With str conversion: 0.000870866775513 s
159.99474375821288

String
Time to compare without str conversion: 5.89370727539e-07 s. With str conversion: 8.30173492432e-07 s
Ratio of time with/without string conversion: 1.40857605178

How to run a program without an operating system?

I wrote a c++ program based on Win32 to write an assembly to the boot sector of a pen-drive. When the computer is booted from the pen-drive it executes the code successfully - have a look here C++ Program to write to the boot sector of a USB Pendrive

This program is a few lines that should be compiled on a compiler with windows compilation configured - such as a visual studio compiler - any available version.

Correct way to delete cookies server-side

Use Max-Age=-1 rather than "Expires". It is shorter, less picky about the syntax, and Max-Age takes precedence over Expires anyway.

VBA - If a cell in column A is not blank the column B equals

Use the function IF :

=IF ( logical_test, value_if_true, value_if_false )

how to make a div to wrap two float divs inside?

This should do it:

<div id="wrap">
  <div id="nav"></div>
  <div id="content"></div>
  <div style="clear:both"></div>
</div>

How can I merge the columns from two tables into one output?

SELECT col1,
  col2
FROM
  (SELECT rownum X,col_table1 FROM table1) T1
INNER JOIN
  (SELECT rownum Y, col_table2 FROM table2) T2
ON T1.X=T2.Y;

Defining and using a variable in batch file

input location.bat

@echo off
cls

set /p "location"="bob"
echo We're working with %location%
pause

output

We're working with bob

(mistakes u done : space and " ")

Change drive in git bash for windows

TL;DR; for Windows users:

(Quotation marks not needed if path has no blank spaces)

Git Bash: cd "/C/Program Files (x86)/Android" // macOS/Linux syntax

Cmd.exe: cd "C:\Program Files (x86)\Android" // windows syntax


When using git bash on windows, you have to:

  • remove the colon after the drive letter
  • replace your back-slashes with forward-slashes
  • If you have blank spaces in your path: Put quotation marks at beginning and end of the path

Git Bash: cd "/C/Program Files (x86)/Android" // macOS/Linux syntax

Cmd.exe: cd "C:\Program Files (x86)\Android" // windows syntax

How to find third or n?? maximum salary from salary table?

MySQL tested solution, assume N = 4:

select min(CustomerID) from (SELECT distinct CustomerID FROM Customers order by CustomerID desc LIMIT 4) as A;

Another example:

select min(country) from (SELECT distinct country FROM Customers order by country desc limit 3);

How to delete a stash created with git stash create?

It also works

git stash drop <index>

like

git stash drop 5

What are major differences between C# and Java?

Comparing Java 7 and C# 3

(Some features of Java 7 aren't mentioned here, but the using statement advantage of all versions of C# over Java 1-6 has been removed.)

Not all of your summary is correct:

  • In Java methods are virtual by default but you can make them final. (In C# they're sealed by default, but you can make them virtual.)
  • There are plenty of IDEs for Java, both free (e.g. Eclipse, Netbeans) and commercial (e.g. IntelliJ IDEA)

Beyond that (and what's in your summary already):

  • Generics are completely different between the two; Java generics are just a compile-time "trick" (but a useful one at that). In C# and .NET generics are maintained at execution time too, and work for value types as well as reference types, keeping the appropriate efficiency (e.g. a List<byte> as a byte[] backing it, rather than an array of boxed bytes.)
  • C# doesn't have checked exceptions
  • Java doesn't allow the creation of user-defined value types
  • Java doesn't have operator and conversion overloading
  • Java doesn't have iterator blocks for simple implemetation of iterators
  • Java doesn't have anything like LINQ
  • Partly due to not having delegates, Java doesn't have anything quite like anonymous methods and lambda expressions. Anonymous inner classes usually fill these roles, but clunkily.
  • Java doesn't have expression trees
  • C# doesn't have anonymous inner classes
  • C# doesn't have Java's inner classes at all, in fact - all nested classes in C# are like Java's static nested classes
  • Java doesn't have static classes (which don't have any instance constructors, and can't be used for variables, parameters etc)
  • Java doesn't have any equivalent to the C# 3.0 anonymous types
  • Java doesn't have implicitly typed local variables
  • Java doesn't have extension methods
  • Java doesn't have object and collection initializer expressions
  • The access modifiers are somewhat different - in Java there's (currently) no direct equivalent of an assembly, so no idea of "internal" visibility; in C# there's no equivalent to the "default" visibility in Java which takes account of namespace (and inheritance)
  • The order of initialization in Java and C# is subtly different (C# executes variable initializers before the chained call to the base type's constructor)
  • Java doesn't have properties as part of the language; they're a convention of get/set/is methods
  • Java doesn't have the equivalent of "unsafe" code
  • Interop is easier in C# (and .NET in general) than Java's JNI
  • Java and C# have somewhat different ideas of enums. Java's are much more object-oriented.
  • Java has no preprocessor directives (#define, #if etc in C#).
  • Java has no equivalent of C#'s ref and out for passing parameters by reference
  • Java has no equivalent of partial types
  • C# interfaces cannot declare fields
  • Java has no unsigned integer types
  • Java has no language support for a decimal type. (java.math.BigDecimal provides something like System.Decimal - with differences - but there's no language support)
  • Java has no equivalent of nullable value types
  • Boxing in Java uses predefined (but "normal") reference types with particular operations on them. Boxing in C# and .NET is a more transparent affair, with a reference type being created for boxing by the CLR for any value type.

This is not exhaustive, but it covers everything I can think of off-hand.

How to create war files

Use ant build code I use this for my project SMS

<property name="WEB-INF" value="${basedir}/WebRoot/WEB-INF" />
<property name="OUT" value="${basedir}/out" />
<property name="WAR_FILE_NAME" value="mywebapplication.war" />
<property name="TEMP" value="${basedir}/temp" />

<target name="help">
    <echo>
        --------------------------------------------------
        compile - Compile
        archive - Generate WAR file
        --------------------------------------------------
    </echo>
</target>

<target name="init">
    <delete dir="${WEB-INF}/classes" />
    <mkdir dir="${WEB-INF}/classes" />
</target>

<target name="compile" depends="init">
    <javac srcdir="${basedir}/src" 
                destdir="${WEB-INF}/classes" 
                classpathref="libs">
    </javac>
</target>

<target name="archive" depends="compile">
    <delete dir="${OUT}" />
    <mkdir dir="${OUT}" />
    <delete dir="${TEMP}" />
    <mkdir dir="${TEMP}" />
    <copy todir="${TEMP}" >
        <fileset dir="${basedir}/WebRoot">
        </fileset>
    </copy>
    <move file="${TEMP}/log4j.properties" 
                    todir="${TEMP}/WEB-INF/classes" />
    <war destfile="${OUT}/${WAR_FILE_NAME}" 
                    basedir="${TEMP}" 
                    compress="true" 
                    webxml="${TEMP}/WEB-INF/web.xml" />
    <delete dir="${TEMP}" />
</target>

<path id="libs">
    <fileset includes="*.jar" dir="${WEB-INF}/lib" />
</path>

ERROR Could not load file or assembly 'AjaxControlToolkit' or one of its dependencies

Might sound obvious but do you definitely have AjaxControlToolkit.dll in your bin?

XAMPP Port 80 in use by "Unable to open process" with PID 4

Simply set Apache to listen on a different port. This can be done by clicking on the "Config" button on the same line as the "Apache" module, select the "httpd.conf" file in the dropdown, then change the "Listen 80" line to "Listen 8080". Save the file and close it.

Now it avoids Port 80 and uses Port 8080 instead without issue. The only additional thing you need to do is make sure to put localhost:8080 in the browser so the browser knows to look on Port 8080. Otherwise it defaults to Port 80 and won't find your local site.

MVC 3 file upload and model binding

For multiple files; note the newer "multiple" attribute for input:

Form:

@using (Html.BeginForm("FileImport","Import",FormMethod.Post, new {enctype = "multipart/form-data"}))
{
    <label for="files">Filename:</label>
    <input type="file" name="files" multiple="true" id="files" />
    <input type="submit"  />
}

Controller:

[HttpPost]
public ActionResult FileImport(IEnumerable<HttpPostedFileBase> files)
{
    return View();
}

DB2 SQL error: SQLCODE: -206, SQLSTATE: 42703

That only means that an undefined column or parameter name was detected. The errror that DB2 gives should point what that may be:

DB2 SQL Error: SQLCODE=-206, SQLSTATE=42703, SQLERRMC=[THE_UNDEFINED_COLUMN_OR_PARAMETER_NAME], DRIVER=4.8.87

Double check your table definition. Maybe you just missed adding something.

I also tried google-ing this problem and saw this:

http://www.coderanch.com/t/515475/JDBC/databases/sql-insert-statement-giving-sqlcode

What is a classpath and how do I set it?

For linux users, and to sum up and add to what others have said here, you should know the following:

  1. $CLASSPATH is what Java uses to look through multiple directories to find all the different classes it needs for your script (unless you explicitly tell it otherwise with the -cp override). Using -cp requires that you keep track of all the directories manually and copy-paste that line every time you run the program (not preferable IMO).

  2. The colon (":") character separates the different directories. There is only one $CLASSPATH and it has all the directories in it. So, when you run "export CLASSPATH=...." you want to include the current value "$CLASSPATH" in order to append to it. For example:

    export CLASSPATH=.
    export CLASSPATH=$CLASSPATH:/usr/share/java/mysql-connector-java-5.1.12.jar
    

    In the first line above, you start CLASSPATH out with just a simple 'dot' which is the path to your current working directory. With that, whenever you run java it will look in the current working directory (the one you're in) for classes. In the second line above, $CLASSPATH grabs the value that you previously entered (.) and appends the path to a mysql dirver. Now, java will look for the driver AND for your classes.

  3. echo $CLASSPATH
    

    is super handy, and what it returns should read like a colon-separated list of all the directories, and .jar files, you want java looking in for the classes it needs.

  4. Tomcat does not use CLASSPATH. Read what to do about that here: https://tomcat.apache.org/tomcat-8.0-doc/class-loader-howto.html

How do I convert an object to an array?

You can also use array_values() method of php

Django: OperationalError No Such Table

It looks like there was an issue with my migration.

I ran ./manage.py schemamigration research --auto and found that many of the fields didn't have a default specified.

So, I ran ./manage.py schemamigration research --init followed by ./manage.py migrate research

Rerunning the server from there did the trick!

How do we determine the number of days for a given month in python

Alternative solution:

>>> from datetime import date
>>> (date(2012, 3, 1) - date(2012, 2, 1)).days
29

How to get Android application id?

Android App ES File Explorer shows the Android package name in the User Apps section which is useful for Bitwarden. Bitwarden refers to this as "android application package ID (or package name)".

Why does the C++ STL not provide any "tree" containers?

Reading through the answers here the common named reasons are that one cannot iterate through the tree or that the tree does not assume the similar interface to other STL containers and one could not use STL algorithms with such tree structure.

Having that in mind I tried to design my own tree data structure which will provide STL-like interface and will be usable with existing STL algorthims as much as possible.

My idea was that the tree must be based on the existing STL containers and that it must not hide the container, so that it will be accessible to use with STL algorithms.

The other important feature the tree must provide is the traversing iterators.

Here is what I was able to come up with: https://github.com/cppfw/utki/blob/master/src/utki/tree.hpp

And here are the tests: https://github.com/cppfw/utki/blob/master/tests/tree/tests.cpp

Generate war file from tomcat webapp folder

Create the war file in a different directory to where the content is otherwise the jar command might try to zip up the file it is creating.

#!/bin/bash

set -euo pipefail

war=app.war
src=contents

# Clean last war build
if [ -e ${war} ]; then
    echo "Removing old war ${war}"
    rm -rf ${war}
fi

# Build war
if [ -d ${src} ]; then
    echo "Found source at ${src}"
    cd ${src}
    jar -cvf ../${war} *
    cd ..
fi

# Show war details
ls -la ${war}

How should I set the default proxy to use default credentials?

From .NET 2.0 you shouldn't need to do this. If you do not explicitly set the Proxy property on a web request it uses the value of the static WebRequest.DefaultWebProxy. If you wanted to change the proxy being used by all subsequent WebRequests, you can set this static DefaultWebProxy property.

The default behaviour of WebRequest.DefaultWebProxy is to use the same underlying settings as used by Internet Explorer.

If you wanted to use different proxy settings to the current user then you would need to code

WebRequest webRequest = WebRequest.Create("http://stackoverflow.com/");
webRequest.Proxy = new WebProxy("http://proxyserver:80/",true);

or

WebRequest.DefaultWebProxy = new WebProxy("http://proxyserver:80/",true);

You should also remember the object model for proxies includes the concept that the proxy can be different depending on the destination hostname. This can make things a bit confusing when debugging and checking the property of webRequest.Proxy. Call

webRequest.Proxy.GetProxy(new Uri("http://google.com.au")) to see the actual details of the proxy server that would be used.

There seems to be some debate about whether you can set webRequest.Proxy or WebRequest.DefaultWebProxy = null to prevent the use of any proxy. This seems to work OK for me but you could set it to new DefaultProxy() with no parameters to get the required behaviour. Another thing to check is that if a proxy element exists in your applications config file, the .NET Framework will NOT use the proxy settings in Internet Explorer.

The MSDN Magazine article Take the Burden Off Users with Automatic Configuration in .NET gives further details of what is happening under the hood.

Traits vs. interfaces

Public Service Announcement:

I want to state for the record that I believe traits are almost always a code smell and should be avoided in favor of composition. It's my opinion that single inheritance is frequently abused to the point of being an anti-pattern and multiple inheritance only compounds this problem. You'll be much better served in most cases by favoring composition over inheritance (be it single or multiple). If you're still interested in traits and their relationship to interfaces, read on ...


Let's start by saying this:

Object-Oriented Programming (OOP) can be a difficult paradigm to grasp. Just because you're using classes doesn't mean your code is Object-Oriented (OO).

To write OO code you need to understand that OOP is really about the capabilities of your objects. You've got to think about classes in terms of what they can do instead of what they actually do. This is in stark contrast to traditional procedural programming where the focus is on making a bit of code "do something."

If OOP code is about planning and design, an interface is the blueprint and an object is the fully constructed house. Meanwhile, traits are simply a way to help build the house laid out by the blueprint (the interface).

Interfaces

So, why should we use interfaces? Quite simply, interfaces make our code less brittle. If you doubt this statement, ask anyone who's been forced to maintain legacy code that wasn't written against interfaces.

The interface is a contract between the programmer and his/her code. The interface says, "As long as you play by my rules you can implement me however you like and I promise I won't break your other code."

So as an example, consider a real-world scenario (no cars or widgets):

You want to implement a caching system for a web application to cut down on server load

You start out by writing a class to cache request responses using APC:

class ApcCacher
{
  public function fetch($key) {
    return apc_fetch($key);
  }
  public function store($key, $data) {
    return apc_store($key, $data);
  }
  public function delete($key) {
    return apc_delete($key);
  }
}

Then, in your HTTP response object, you check for a cache hit before doing all the work to generate the actual response:

class Controller
{
  protected $req;
  protected $resp;
  protected $cacher;

  public function __construct(Request $req, Response $resp, ApcCacher $cacher=NULL) {
    $this->req    = $req;
    $this->resp   = $resp;
    $this->cacher = $cacher;

    $this->buildResponse();
  }

  public function buildResponse() {
    if (NULL !== $this->cacher && $response = $this->cacher->fetch($this->req->uri()) {
      $this->resp = $response;
    } else {
      // Build the response manually
    }
  }

  public function getResponse() {
    return $this->resp;
  }
}

This approach works great. But maybe a few weeks later you decide you want to use a file-based cache system instead of APC. Now you have to change your controller code because you've programmed your controller to work with the functionality of the ApcCacher class rather than to an interface that expresses the capabilities of the ApcCacher class. Let's say instead of the above you had made the Controller class reliant on a CacherInterface instead of the concrete ApcCacher like so:

// Your controller's constructor using the interface as a dependency
public function __construct(Request $req, Response $resp, CacherInterface $cacher=NULL)

To go along with that you define your interface like so:

interface CacherInterface
{
  public function fetch($key);
  public function store($key, $data);
  public function delete($key);
}

In turn you have both your ApcCacher and your new FileCacher classes implement the CacherInterface and you program your Controller class to use the capabilities required by the interface.

This example (hopefully) demonstrates how programming to an interface allows you to change the internal implementation of your classes without worrying if the changes will break your other code.

Traits

Traits, on the other hand, are simply a method for re-using code. Interfaces should not be thought of as a mutually exclusive alternative to traits. In fact, creating traits that fulfill the capabilities required by an interface is the ideal use case.

You should only use traits when multiple classes share the same functionality (likely dictated by the same interface). There's no sense in using a trait to provide functionality for a single class: that only obfuscates what the class does and a better design would move the trait's functionality into the relevant class.

Consider the following trait implementation:

interface Person
{
    public function greet();
    public function eat($food);
}

trait EatingTrait
{
    public function eat($food)
    {
        $this->putInMouth($food);
    }

    private function putInMouth($food)
    {
        // Digest delicious food
    }
}

class NicePerson implements Person
{
    use EatingTrait;

    public function greet()
    {
        echo 'Good day, good sir!';
    }
}

class MeanPerson implements Person
{
    use EatingTrait;

    public function greet()
    {
        echo 'Your mother was a hamster!';
    }
}

A more concrete example: imagine both your FileCacher and your ApcCacher from the interface discussion use the same method to determine whether a cache entry is stale and should be deleted (obviously this isn't the case in real life, but go with it). You could write a trait and allow both classes to use it to for the common interface requirement.

One final word of caution: be careful not to go overboard with traits. Often traits are used as a crutch for poor design when unique class implementations would suffice. You should limit traits to fulfilling interface requirements for best code design.

MySQL Data - Best way to implement paging?

There's literature about it:

The main problem happens with the usage of large OFFSETs. They avoid using OFFSET with a variety of techniques, ranging from id range selections in the WHERE clause, to some kind of caching or pre-computing pages.

There are suggested solutions at Use the INDEX, Luke:

How to delete cookies on an ASP.NET website

Unfortunately, for me, setting "Expires" did not always work. The cookie was unaffected.

This code did work for me:

HttpContext.Current.Session.Abandon();
HttpContext.Current.Response.Cookies.Add(new HttpCookie("ASP.NET_SessionId", ""));

where "ASP.NET_SessionId" is the name of the cookie. This does not really delete the cookie, but overrides it with a blank cookie, which was close enough for me.

Sending a JSON HTTP POST request from Android

Posting parameters Using POST:-

URL url;
URLConnection urlConn;
DataOutputStream printout;
DataInputStream  input;
url = new URL (getCodeBase().toString() + "env.tcgi");
urlConn = url.openConnection();
urlConn.setDoInput (true);
urlConn.setDoOutput (true);
urlConn.setUseCaches (false);
urlConn.setRequestProperty("Content-Type","application/json");   
urlConn.setRequestProperty("Host", "android.schoolportal.gr");
urlConn.connect();  
//Create JSONObject here
JSONObject jsonParam = new JSONObject();
jsonParam.put("ID", "25");
jsonParam.put("description", "Real");
jsonParam.put("enable", "true");

The part which you missed is in the the following... i.e., as follows..

// Send POST output.
printout = new DataOutputStream(urlConn.getOutputStream ());
printout.writeBytes(URLEncoder.encode(jsonParam.toString(),"UTF-8"));
printout.flush ();
printout.close ();

The rest of the thing you can do it.

How do I access my webcam in Python?

gstreamer can handle webcam input. If I remeber well, there are python bindings for it!

Restoring MySQL database from physical files

A MySQL MyISAM table is the combination of three files:

  • The FRM file is the table definition.
  • The MYD file is where the actual data is stored.
  • The MYI file is where the indexes created on the table are stored.

You should be able to restore by copying them in your database folder (In linux, the default location is /var/lib/mysql/)

You should do it while the server is not running.

Android ListView with onClick items

listview.setOnItemClickListener(new OnItemClickListener(){

    @Override
    public void onItemClick(AdapterView<?>adapter,View v, int position){
    Intent intent;
    switch(position){
      case 0:
        intent = new Intent(Activity.this,firstActivity.class);
        break;
      case 1:
        intent = new Intent(Activity.this,secondActivity.class);
        break;
     case 2:
        intent = new Intent(Activity.this,thirdActivity.class);
        break;
    //add more if you have more items in listview
   //0 is the first item 1 second and so on...
    }
    startActivity(intent);
  }

});

MySQL Select Query - Get only first 10 characters of a value

Using the below line

SELECT LEFT(subject , 10) FROM tbl 

MySQL Doc.

Converting an int to a binary string representation in Java?

There is also the java.lang.Integer.toString(int i, int base) method, which would be more appropriate if your code might one day handle bases other than 2 (binary). Keep in mind that this method only gives you an unsigned representation of the integer i, and if it is negative, it will tack on a negative sign at the front. It won't use two's complement.

How to set the size of a column in a Bootstrap responsive table

You could use inline styles and define the width in the <th> tag. Make it so that the sum of the widths = 100%.

    <tr>
        <th style="width:10%">Size</th>
        <th style="width:30%">Bust</th>
        <th style="width:50%">Waist</th>
        <th style="width:10%">Hips</th>
    </tr>

Bootply demo

Typically using inline styles is not ideal, however this does provide flexibility because you can get very specific and granular with exact widths.

Updating version numbers of modules in a multi-module Maven project

the easiest way is to change version in every pom.xml to arbitrary version. then check that dependency management to use the correct version of the module used in this module! for example, if u want increase versioning for a tow module project u must do like flowing:

in childe module :

    <parent>
       <artifactId>A-application</artifactId>
       <groupId>com.A</groupId>
       <version>new-version</version>
    </parent>

and in parent module :

<groupId>com.A</groupId>
<artifactId>A-application</artifactId>
<version>new-version</version>

Can HTML be embedded inside PHP "if" statement?

I know this is an old post, but I really hate that there is only one answer here that suggests not mixing html and php. Instead of mixing content one should use template systems, or create a basic template system themselves.

In the php

<?php 
  $var1 = 'Alice'; $var2 = 'apples'; $var3 = 'lunch'; $var4 = 'Bob';

  if ($var1 == 'Alice') {
    $html = file_get_contents('/path/to/file.html'); //get the html template
    $template_placeholders = array('##variable1##', '##variable2##', '##variable3##', '##variable4##'); // variable placeholders inside the template
    $template_replace_variables = array($var1, $var2, $var3, $var4); // the variables to pass to the template
    $html_output = str_replace($template_placeholders, $template_replace_variables, $html); // replace the placeholders with the actual variable values.
  }

  echo $html_output;
?>

In the html (/path/to/file.html)

<p>##variable1## ate ##variable2## for ##variable3## with ##variable4##.</p>

The output of this would be:

Alice ate apples for lunch with Bob.

Get Line Number of certain phrase in file Python

Open your file, and then do something like...

for line in f:
    nlines += 1
    if (line.find(phrase) >= 0):
        print "Its here.", nlines

There are numerous ways of reading lines from files in Python, but the for line in f technique is more efficient than most.

OnChange event using React JS for drop down

Thank you Felix Kling, but his answer need a little change:

var MySelect = React.createClass({
 getInitialState: function() {
     return {
         value: 'select'
     }
 },
 change: function(event){
     this.setState({value: event.target.value});
 },
 render: function(){
    return(
       <div>
           <select id="lang" onChange={this.change.bind(this)} value={this.state.value}>
              <option value="select">Select</option>
              <option value="Java">Java</option>
              <option value="C++">C++</option>
           </select>
           <p></p>
           <p>{this.state.value}</p>
       </div>
    );
 }
});
React.render(<MySelect />, document.body); 

Where and why do I have to put the "template" and "typename" keywords?

(See here also for my C++11 answer)

In order to parse a C++ program, the compiler needs to know whether certain names are types or not. The following example demonstrates that:

t * f;

How should this be parsed? For many languages a compiler doesn't need to know the meaning of a name in order to parse and basically know what action a line of code does. In C++, the above however can yield vastly different interpretations depending on what t means. If it's a type, then it will be a declaration of a pointer f. However if it's not a type, it will be a multiplication. So the C++ Standard says at paragraph (3/7):

Some names denote types or templates. In general, whenever a name is encountered it is necessary to determine whether that name denotes one of these entities before continuing to parse the program that contains it. The process that determines this is called name lookup.

How will the compiler find out what a name t::x refers to, if t refers to a template type parameter? x could be a static int data member that could be multiplied or could equally well be a nested class or typedef that could yield to a declaration. If a name has this property - that it can't be looked up until the actual template arguments are known - then it's called a dependent name (it "depends" on the template parameters).

You might recommend to just wait till the user instantiates the template:

Let's wait until the user instantiates the template, and then later find out the real meaning of t::x * f;.

This will work and actually is allowed by the Standard as a possible implementation approach. These compilers basically copy the template's text into an internal buffer, and only when an instantiation is needed, they parse the template and possibly detect errors in the definition. But instead of bothering the template's users (poor colleagues!) with errors made by a template's author, other implementations choose to check templates early on and give errors in the definition as soon as possible, before an instantiation even takes place.

So there has to be a way to tell the compiler that certain names are types and that certain names aren't.

The "typename" keyword

The answer is: We decide how the compiler should parse this. If t::x is a dependent name, then we need to prefix it by typename to tell the compiler to parse it in a certain way. The Standard says at (14.6/2):

A name used in a template declaration or definition and that is dependent on a template-parameter is assumed not to name a type unless the applicable name lookup finds a type name or the name is qualified by the keyword typename.

There are many names for which typename is not necessary, because the compiler can, with the applicable name lookup in the template definition, figure out how to parse a construct itself - for example with T *f;, when T is a type template parameter. But for t::x * f; to be a declaration, it must be written as typename t::x *f;. If you omit the keyword and the name is taken to be a non-type, but when instantiation finds it denotes a type, the usual error messages are emitted by the compiler. Sometimes, the error consequently is given at definition time:

// t::x is taken as non-type, but as an expression the following misses an
// operator between the two names or a semicolon separating them.
t::x f;

The syntax allows typename only before qualified names - it is therefor taken as granted that unqualified names are always known to refer to types if they do so.

A similar gotcha exists for names that denote templates, as hinted at by the introductory text.

The "template" keyword

Remember the initial quote above and how the Standard requires special handling for templates as well? Let's take the following innocent-looking example:

boost::function< int() > f;

It might look obvious to a human reader. Not so for the compiler. Imagine the following arbitrary definition of boost::function and f:

namespace boost { int function = 0; }
int main() { 
  int f = 0;
  boost::function< int() > f; 
}

That's actually a valid expression! It uses the less-than operator to compare boost::function against zero (int()), and then uses the greater-than operator to compare the resulting bool against f. However as you might well know, boost::function in real life is a template, so the compiler knows (14.2/3):

After name lookup (3.4) finds that a name is a template-name, if this name is followed by a <, the < is always taken as the beginning of a template-argument-list and never as a name followed by the less-than operator.

Now we are back to the same problem as with typename. What if we can't know yet whether the name is a template when parsing the code? We will need to insert template immediately before the template name, as specified by 14.2/4. This looks like:

t::template f<int>(); // call a function template

Template names can not only occur after a :: but also after a -> or . in a class member access. You need to insert the keyword there too:

this->template f<int>(); // call a function template

Dependencies

For the people that have thick Standardese books on their shelf and that want to know what exactly I was talking about, I'll talk a bit about how this is specified in the Standard.

In template declarations some constructs have different meanings depending on what template arguments you use to instantiate the template: Expressions may have different types or values, variables may have different types or function calls might end up calling different functions. Such constructs are generally said to depend on template parameters.

The Standard defines precisely the rules by whether a construct is dependent or not. It separates them into logically different groups: One catches types, another catches expressions. Expressions may depend by their value and/or their type. So we have, with typical examples appended:

  • Dependent types (e.g: a type template parameter T)
  • Value-dependent expressions (e.g: a non-type template parameter N)
  • Type-dependent expressions (e.g: a cast to a type template parameter (T)0)

Most of the rules are intuitive and are built up recursively: For example, a type constructed as T[N] is a dependent type if N is a value-dependent expression or T is a dependent type. The details of this can be read in section (14.6.2/1) for dependent types, (14.6.2.2) for type-dependent expressions and (14.6.2.3) for value-dependent expressions.

Dependent names

The Standard is a bit unclear about what exactly is a dependent name. On a simple read (you know, the principle of least surprise), all it defines as a dependent name is the special case for function names below. But since clearly T::x also needs to be looked up in the instantiation context, it also needs to be a dependent name (fortunately, as of mid C++14 the committee has started to look into how to fix this confusing definition).

To avoid this problem, I have resorted to a simple interpretation of the Standard text. Of all the constructs that denote dependent types or expressions, a subset of them represent names. Those names are therefore "dependent names". A name can take different forms - the Standard says:

A name is a use of an identifier (2.11), operator-function-id (13.5), conversion-function-id (12.3.2), or template-id (14.2) that denotes an entity or label (6.6.4, 6.1)

An identifier is just a plain sequence of characters / digits, while the next two are the operator + and operator type form. The last form is template-name <argument list>. All these are names, and by conventional use in the Standard, a name can also include qualifiers that say what namespace or class a name should be looked up in.

A value dependent expression 1 + N is not a name, but N is. The subset of all dependent constructs that are names is called dependent name. Function names, however, may have different meaning in different instantiations of a template, but unfortunately are not caught by this general rule.

Dependent function names

Not primarily a concern of this article, but still worth mentioning: Function names are an exception that are handled separately. An identifier function name is dependent not by itself, but by the type dependent argument expressions used in a call. In the example f((T)0), f is a dependent name. In the Standard, this is specified at (14.6.2/1).

Additional notes and examples

In enough cases we need both of typename and template. Your code should look like the following

template <typename T, typename Tail>
struct UnionNode : public Tail {
    // ...
    template<typename U> struct inUnion {
        typedef typename Tail::template inUnion<U> dummy;
    };
    // ...
};

The keyword template doesn't always have to appear in the last part of a name. It can appear in the middle before a class name that's used as a scope, like in the following example

typename t::template iterator<int>::value_type v;

In some cases, the keywords are forbidden, as detailed below

  • On the name of a dependent base class you are not allowed to write typename. It's assumed that the name given is a class type name. This is true for both names in the base-class list and the constructor initializer list:

     template <typename T>
     struct derive_from_Has_type : /* typename */ SomeBase<T>::type 
     { };
    
  • In using-declarations it's not possible to use template after the last ::, and the C++ committee said not to work on a solution.

     template <typename T>
     struct derive_from_Has_type : SomeBase<T> {
        using SomeBase<T>::template type; // error
        using typename SomeBase<T>::type; // typename *is* allowed
     };
    

is inaccessible due to its protection level

In your Main method, you're trying to access, for instance, club (which is protected), when you should be accessing myclub which is the public property that you created.

GDB: Listing all mapped memory regions for a crashed process

The problem with maintenance info sections is that command tries to extract information from the section header of the binary. It does not work if the binary is tripped (e.g by sstrip) or it gives wrong information when the loader may change the memory permission after loading (e.g. the case of RELRO).

How to set editable true/false EditText in Android programmatically?

try this,

EditText editText=(EditText)findViewById(R.id.editText1);

editText.setKeyListener(null);

It works fine...

Setting new value for an attribute using jQuery

Works fine for me

See example here. http://jsfiddle.net/blowsie/c6VAy/

Make sure your jquery is inside $(document).ready function or similar.

Also you can improve your code by using jquery data

$('#amount').data('min','1000');

<div id="amount" data-min=""></div>

Update,

A working example of your full code (pretty much) here. http://jsfiddle.net/blowsie/c6VAy/3/

Abort trap 6 error in C

Try this:

void drawInitialNim(int num1, int num2, int num3){
    int board[3][50] = {0}; // This is a local variable. It is not possible to use it after returning from this function. 

    int i, j, k;

    for(i=0; i<num1; i++)
        board[0][i] = 'O';
    for(i=0; i<num2; i++)
        board[1][i] = 'O';
    for(i=0; i<num3; i++)
        board[2][i] = 'O';

    for (j=0; j<3;j++) {
        for (k=0; k<50; k++) {
            if(board[j][k] != 0)
                printf("%c", board[j][k]);
        }
        printf("\n");
    }
}

Simple PowerShell LastWriteTime compare

Slightly easier - use the new-timespan cmdlet, which creates a time interval from the current time.

ls | where-object {(new-timespan $_.LastWriteTime).days -ge 1}

shows all files not written to today.

How to exclude records with certain values in sql select

One way:

SELECT DISTINCT sc.StoreId
FROM StoreClients sc
WHERE NOT EXISTS(
    SELECT * FROM StoreClients sc2 
    WHERE sc2.StoreId = sc.StoreId AND sc2.ClientId = 5)

Should I use px or rem value units in my CSS?

This article describes pretty well the pros and cons of px, em, and rem.

The author finally concludes that the best method is probably to use both px and rem, declaring px first for older browsers and redeclaring rem for newer browsers:

html { font-size: 62.5%; } 
body { font-size: 14px; font-size: 1.4rem; } /* =14px */
h1   { font-size: 24px; font-size: 2.4rem; } /* =24px */

Force encode from US-ASCII to UTF-8 (iconv)

People say you can't and I understand you may be frustrated when asking a question and getting such an answer.

If you really want it to show in UTF-8 instead of US ASCII then you need to do it in two steps.

First:

iconv -f us-ascii -t utf-16 yourfile > youfileinutf16.*

Second:

iconv -f utf-16le -t utf-8 yourfileinutf16 > yourfileinutf8.*

Then if you do a file -i, you'll see the new character set is UTF-8.

Android file chooser

EDIT (02 Jan 2012):

I created a small open source Android Library Project that streamlines this process, while also providing a built-in file explorer (in case the user does not have one present). It's extremely simple to use, requiring only a few lines of code.

You can find it at GitHub: aFileChooser.


ORIGINAL

If you want the user to be able to choose any file in the system, you will need to include your own file manager, or advise the user to download one. I believe the best you can do is look for "openable" content in an Intent.createChooser() like this:

private static final int FILE_SELECT_CODE = 0;

private void showFileChooser() {
    Intent intent = new Intent(Intent.ACTION_GET_CONTENT); 
    intent.setType("*/*"); 
    intent.addCategory(Intent.CATEGORY_OPENABLE);

    try {
        startActivityForResult(
                Intent.createChooser(intent, "Select a File to Upload"),
                FILE_SELECT_CODE);
    } catch (android.content.ActivityNotFoundException ex) {
        // Potentially direct the user to the Market with a Dialog
        Toast.makeText(this, "Please install a File Manager.", 
                Toast.LENGTH_SHORT).show();
    }
}

You would then listen for the selected file's Uri in onActivityResult() like so:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    switch (requestCode) {
        case FILE_SELECT_CODE:
        if (resultCode == RESULT_OK) {
            // Get the Uri of the selected file 
            Uri uri = data.getData();
            Log.d(TAG, "File Uri: " + uri.toString());
            // Get the path
            String path = FileUtils.getPath(this, uri);
            Log.d(TAG, "File Path: " + path);
            // Get the file instance
            // File file = new File(path);
            // Initiate the upload
        }
        break;
    }
    super.onActivityResult(requestCode, resultCode, data);
}

The getPath() method in my FileUtils.java is:

public static String getPath(Context context, Uri uri) throws URISyntaxException {
    if ("content".equalsIgnoreCase(uri.getScheme())) {
        String[] projection = { "_data" };
        Cursor cursor = null;

        try {
            cursor = context.getContentResolver().query(uri, projection, null, null, null);
            int column_index = cursor.getColumnIndexOrThrow("_data");
            if (cursor.moveToFirst()) {
                return cursor.getString(column_index);
            }
        } catch (Exception e) {
            // Eat it
        }
    }
    else if ("file".equalsIgnoreCase(uri.getScheme())) {
        return uri.getPath();
    }

    return null;
} 

How to mark a build unstable in Jenkins when running shell scripts

One easy way to set a build as unstable, is in your "execute shell" block, run exit 13

How to abort a Task like aborting a Thread (Thread.Abort method)?

If you have Task constructor, then we may extract Thread from the Task, and invoke thread.abort.

Thread th = null;

Task.Factory.StartNew(() =>
{
    th = Thread.CurrentThread;

    while (true)
    {
        Console.WriteLine(DateTime.UtcNow);
    }
});

Thread.Sleep(2000);
th.Abort();
Console.ReadKey();

How to get the return value from a thread in python?

One usual solution is to wrap your function foo with a decorator like

result = queue.Queue()

def task_wrapper(*args):
    result.put(target(*args))

Then the whole code may looks like that

result = queue.Queue()

def task_wrapper(*args):
    result.put(target(*args))

threads = [threading.Thread(target=task_wrapper, args=args) for args in args_list]

for t in threads:
    t.start()
    while(True):
        if(len(threading.enumerate()) < max_num):
            break
for t in threads:
    t.join()
return result

Note

One important issue is that the return values may be unorderred. (In fact, the return value is not necessarily saved to the queue, since you can choose arbitrary thread-safe data structure )

java.lang.NoClassDefFoundError: com/fasterxml/jackson/core/JsonFactory

Solved the problem by upgrading the dependency to below version

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.9.8</version>
</dependency>

Javascript string/integer comparisons

Comparing Numbers to String Equivalents Without Using parseInt

console.log(Number('2') > Number('10'));
console.log( ('2'/1) > ('10'/1) );

var item = { id: 998 }, id = '998';
var isEqual = (item.id.toString() === id.toString());
isEqual;

Image, saved to sdcard, doesn't appear in Android's Gallery app

You can also add an Image to the Media Gallery by intent, have a look at the example code to see how it is done:

ContentValues image = new ContentValues();

image.put(Images.Media.TITLE, imageTitle);
image.put(Images.Media.DISPLAY_NAME, imageDisplayName);
image.put(Images.Media.DESCRIPTION, imageDescription);
image.put(Images.Media.DATE_ADDED, dateTaken);
image.put(Images.Media.DATE_TAKEN, dateTaken);
image.put(Images.Media.DATE_MODIFIED, dateTaken);
image.put(Images.Media.MIME_TYPE, "image/png");
image.put(Images.Media.ORIENTATION, 0);

 File parent = imageFile.getParentFile();
 String path = parent.toString().toLowerCase();
 String name = parent.getName().toLowerCase();
 image.put(Images.ImageColumns.BUCKET_ID, path.hashCode());
 image.put(Images.ImageColumns.BUCKET_DISPLAY_NAME, name);
 image.put(Images.Media.SIZE, imageFile.length());

 image.put(Images.Media.DATA, imageFile.getAbsolutePath());

 Uri result = context.getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, image);

Add rows to CSV File in powershell

I know this is an old thread but it was the first I found when searching. The += solution did not work for me. The code that I did get to work is as below.

#this bit creates the CSV if it does not already exist
$headers = "Name", "Primary Type"
$psObject = New-Object psobject
foreach($header in $headers)
{
 Add-Member -InputObject $psobject -MemberType noteproperty -Name $header -Value ""
}
$psObject | Export-Csv $csvfile -NoTypeInformation

#this bit appends a new row to the CSV file
$bName = "My Name"
$bPrimaryType = "My Primary Type"
    $hash = @{
             "Name" =  $bName
             "Primary Type" = $bPrimaryType
              }

$newRow = New-Object PsObject -Property $hash
Export-Csv $csvfile -inputobject $newrow -append -Force

I was able to use this as a function to loop through a series of arrays and enter the contents into the CSV file.

It works in powershell 3 and above.

Re-render React component when prop changes

I would recommend having a look at this answer of mine, and see if it is relevant to what you are doing. If I understand your real problem, it's that your just not using your async action correctly and updating the redux "store", which will automatically update your component with it's new props.

This section of your code:

componentDidMount() {
      if (this.props.isManager) {
        this.props.dispatch(actions.fetchAllSites())
      } else {
        const currentUserId = this.props.user.get('id')
        this.props.dispatch(actions.fetchUsersSites(currentUserId))
      }  
    }

Should not be triggering in a component, it should be handled after executing your first request.

Have a look at this example from redux-thunk:

function makeASandwichWithSecretSauce(forPerson) {

  // Invert control!
  // Return a function that accepts `dispatch` so we can dispatch later.
  // Thunk middleware knows how to turn thunk async actions into actions.

  return function (dispatch) {
    return fetchSecretSauce().then(
      sauce => dispatch(makeASandwich(forPerson, sauce)),
      error => dispatch(apologize('The Sandwich Shop', forPerson, error))
    );
  };
}

You don't necessarily have to use redux-thunk, but it will help you reason about scenarios like this and write code to match.

AngularJS $watch window resize inside directive

// Following is angular 2.0 directive for window re size that adjust scroll bar for give element as per your tag

---- angular 2.0 window resize directive.
import { Directive, ElementRef} from 'angular2/core';

@Directive({
       selector: '[resize]',
       host: { '(window:resize)': 'onResize()' } // Window resize listener
})

export class AutoResize {

element: ElementRef; // Element that associated to attribute.
$window: any;
       constructor(_element: ElementRef) {

         this.element = _element;
         // Get instance of DOM window.
         this.$window = angular.element(window);

         this.onResize();

    }

    // Adjust height of element.
    onResize() {
         $(this.element.nativeElement).css('height', (this.$window.height() - 163) + 'px');
   }
}

Disabled form fields not submitting data

add CSS or class to the input element which works in select and text tags like

style="pointer-events: none;background-color:#E9ECEF"

How to check compiler log in sql developer?

control-shift-L should open the log(s) for you. this will by default be the messages log, but if you create the item that is creating the error the Compiler Log will show up (for me the box shows up in the bottom middle left).

if the messages log is the only log that shows up, simply re-execute the item that was causing the failure and the compiler log will show up

for instance, hit Control-shift-L then execute this

CREATE OR REPLACE FUNCTION TEST123() IS
BEGIN
VAR := 2;
end TEST123;

and you will see the message "Error(1,18): PLS-00103: Encountered the symbol ")" when expecting one of the following: current delete exists prior "

(You can also see this in "View--Log")

One more thing, if you are having a problem with a (function || package || procedure) if you do the coding via the SQL Developer interface (by finding the object in question on the connections tab and editing it the error will be immediately displayed (and even underlined at times)

Iframe positioning

you have to use this css property,

 position:relative;

use it for your #contentframe div tag

Maven plugins can not be found in IntelliJ

I have change the Maven home directory from Bundled(Maven 3) to Bundled(Maven 2) in the maven setting. And this works for me. Have a try!

XML Schema minOccurs / maxOccurs default values

Short answer:

As written in xsd:

<xs:attribute name="minOccurs" type="xs:nonNegativeInteger" use="optional" default="1"/>
<xs:attribute name="maxOccurs" type="xs:allNNI" use="optional" default="1"/>

If you provide an attribute with number, then the number is boundary. Otherwise attribute should appear exactly once.

Android - get children inside a View?

I'm just going to provide this answer as an alternative @IHeartAndroid's recursive algorithm for discovering all child Views in a view hierarchy. Note that at the time of this writing, the recursive solution is flawed in that it will contains duplicates in its result.

For those who have trouble wrapping their head around recursion, here's a non-recursive alternative. You get bonus points for realizing this is also a breadth-first search alternative to the depth-first approach of the recursive solution.

private List<View> getAllChildrenBFS(View v) {
    List<View> visited = new ArrayList<View>();
    List<View> unvisited = new ArrayList<View>();
    unvisited.add(v);

    while (!unvisited.isEmpty()) {
        View child = unvisited.remove(0);
        visited.add(child);
        if (!(child instanceof ViewGroup)) continue;
        ViewGroup group = (ViewGroup) child;
        final int childCount = group.getChildCount();
        for (int i=0; i<childCount; i++) unvisited.add(group.getChildAt(i));
    }

    return visited;
}

A couple of quick tests (nothing formal) suggest this alternative is also faster, although that has most likely to do with the number of new ArrayList instances the other answer creates. Also, results may vary based on how vertical/horizontal the view hierarchy is.

Cross-posted from: Android | Get all children elements of a ViewGroup

node.js: read a text file into an array. (Each line an item in the array.)

To read a big file into array you can read line by line or chunk by chunk.

line by line refer to my answer here

var fs = require('fs'),
    es = require('event-stream'),

var lines = [];

var s = fs.createReadStream('filepath')
    .pipe(es.split())
    .pipe(es.mapSync(function(line) {
        //pause the readstream
        s.pause();
        lines.push(line);
        s.resume();
    })
    .on('error', function(err) {
        console.log('Error:', err);
    })
    .on('end', function() {
        console.log('Finish reading.');
        console.log(lines);
    })
);

chunk by chunk refer to this article

var offset = 0;
var chunkSize = 2048;
var chunkBuffer = new Buffer(chunkSize);
var fp = fs.openSync('filepath', 'r');
var bytesRead = 0;
while(bytesRead = fs.readSync(fp, chunkBuffer, 0, chunkSize, offset)) {
    offset += bytesRead;
    var str = chunkBuffer.slice(0, bytesRead).toString();
    var arr = str.split('\n');

    if(bytesRead = chunkSize) {
        // the last item of the arr may be not a full line, leave it to the next chunk
        offset -= arr.pop().length;
    }
    lines.push(arr);
}
console.log(lines);

PhoneGap Eclipse Issue - eglCodecCommon glUtilsParamSize: unknow param errors

This is an error that you see when your emulator has the "Use host GPU" setting checked. If you uncheck it then the error goes away. Of course, then your emulator is not as responsive anymore.

CSS: styled a checkbox to look like a button, is there a hover?

it looks like you need a rule very similar to your checked rule

http://jsfiddle.net/VWBN4/3

#ck-button input:hover + span {
    background-color:#191;
    color:#fff;
}

and for hover and clicked state:

#ck-button input:checked:hover + span {
    background-color:#c11;
    color:#fff;
}

the order is important though.

Sniffing/logging your own Android Bluetooth traffic

Android 4.4 (Kit Kat) does have a new sniffing capability for Bluetooth. You should give it a try.

If you don’t own a sniffing device however, you aren’t necessarily out of luck. In many cases we can obtain positive results with a new feature introduced in Android 4.4: the ability to capture all Bluetooth HCI packets and save them to a file.

When the Analyst has finished populating the capture file by running the application being tested, he can pull the file generated by Android into the external storage of the device and analyze it (with Wireshark, for example).

Once this setting is activated, Android will save the packet capture to /sdcard/btsnoop_hci.log to be pulled by the analyst and inspected.

Type the following in case /sdcard/ is not the right path on your particular device:

adb shell echo \$EXTERNAL_STORAGE

We can then open a shell and pull the file: $adb pull /sdcard/btsnoop_hci.log and inspect it with Wireshark, just like a PCAP collected by sniffing WiFi traffic for example, so it is very simple and well supported:

screenshot of wireshark capture using Android HCI Snoop

[source]

You can enable this by going to Settings->Developer Options, then checking the box next to "Bluetooth HCI Snoop Log."

How to install and use "make" in Windows?

  1. Install npm
  2. install Node
  3. Install Make node install make up node install make if above commands displays any error then install Chocolatey(choco) Open cmd and copy and paste the below command (command copied from chocolatey URL) @"%SystemRoot%\System32\WindowsPowerShell\v1.0\powershell.exe" -NoProfile -InputFormat None -ExecutionPolicy Bypass -Command " [System.Net.ServicePointManager]::SecurityProtocol = 3072; iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'))" && SET "PATH=%PATH%;%ALLUSERSPROFILE%\chocolatey\bin"

How do you post data with a link

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

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

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

how to open a page in new tab on button click in asp.net?

add target='_blank' after check validation :

_x000D_
_x000D_
    <asp:button id="_ButPrint"  ValidationGroup="print" OnClientClick="if (Page_ClientValidate()){$('form').attr('target','_blank');}"  runat="server" onclick="ButPrint_Click" Text="print" />
                                                                 
_x000D_
_x000D_
_x000D_

How to debug a Flask app

One can also use the Flask Debug Toolbar extension to get more detailed information embedded in rendered pages.

from flask import Flask
from flask_debugtoolbar import DebugToolbarExtension
import logging

app = Flask(__name__)
app.debug = True
app.secret_key = 'development key'

toolbar = DebugToolbarExtension(app)

@app.route('/')
def index():
    logging.warning("See this message in Flask Debug Toolbar!")
    return "<html><body></body></html>"

Start the application as follows:

FLASK_APP=main.py FLASK_DEBUG=1 flask run

Error:java: invalid source release: 8 in Intellij. What does it mean?

As Andreas mentioned all about:

Error:java: invalid source release: 8 in IntelliJ
Error:java: invalid source release: 13 in IntelliJ
Error:java: invalid source release: 14 in IntelliJ...

OR whatever version you are using in Java...

The problem will exist if you do not have it matching inside the below code:

<properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
</properties>

This 1.8 in my case, must be matching on your device through MAVEN project library, settings, preferences, project setting and SDK.

Finding local maxima/minima with Numpy in a 1D numpy array

While this question is really old. I believe there is a much simpler approach in numpy (a one liner).

import numpy as np

list = [1,3,9,5,2,5,6,9,7]

np.diff(np.sign(np.diff(list))) #the one liner

#output
array([ 0, -2,  0,  2,  0,  0, -2])

To find a local max or min we essentially want to find when the difference between the values in the list (3-1, 9-3...) changes from positive to negative (max) or negative to positive (min). Therefore, first we find the difference. Then we find the sign, and then we find the changes in sign by taking the difference again. (Sort of like a first and second derivative in calculus, only we have discrete data and don't have a continuous function.)

The output in my example does not contain the extrema (the first and last values in the list). Also, just like calculus, if the second derivative is negative, you have max, and if it is positive you have a min.

Thus we have the following matchup:

[1,  3,  9,  5,  2,  5,  6,  9,  7]
    [0, -2,  0,  2,  0,  0, -2]
        Max     Min         Max

How to resize image automatically on browser width resize but keep same height?

changing the width of the image will automatically change the height...

how many pictures do you want to have this functionality? If it's a lot and they all have DIFFERENT Heights you should probably just let the height change as well.

Lets say you have 5 images that have height 400px , in your html give those five tags the class of fixed

.fixed { width: 100%; height: 500px !important }

This should let the width change but keep the height the same.

How can I use ":" as an AWK field separator?

AWK works as a text interpreter that goes linewise for the whole document and that goes fieldwise for each line. Thus $1, $2...$n are references to the fields of each line ($1 is the first field, $2 is the second field, and so on...).

You can define a field separator by using the "-F" switch under the command line or within two brackets with "FS=...".

Now consider the answer of Jürgen:

echo "1: " | awk -F  ":" '/1/ {print $1}'

Above the field, boundaries are set by ":" so we have two fields $1 which is "1" and $2 which is the empty space. After comes the regular expression "/1/" that instructs the filter to output the first field only when the interpreter stumbles upon a line containing such an expression (I mean 1).

The output of the "echo" command is one line that contains "1", so the filter will work...

When dealing with the following example:

echo "1: " | awk '/1/ -F ":" {print $1}'

The syntax is messy and the interpreter chose to ignore the part F ":" and switches to the default field splitter which is the empty space, thus outputting "1:" as the first field and there will be not a second field!

The answer of Jürgen contains the good syntax...

Convert double to Int, rounded down

double myDouble = 420.5;
//Type cast double to int
int i = (int)myDouble;
System.out.println(i);

The double value is 420.5 and the application prints out the integer value of 420

How to clear browser cache with php?

It seams you need to versionate, so when some change happens browser will catch something new and user won't need to clear browser's cache.

You can do it by subfolders (example /css/v1/style.css) or by filename (example: css/style_v1.css) or even by setting different folders for your website, example:

www.mywebsite.com/site1

www.mywebsite.com/site2

www.mywebsite.com/site3

And use a .htaccess or even change httpd.conf to redirect to your current application.

If's about one image or page:

    <?$time = date("H:i:s");?>
    <img src="myfile.jpg?time=<?$time;?>">

You can use $time on parts when you don't wanna cache. So it will always pull a new image. Versionate it seams a better approach, otherwise it can overload your server. Remember, browser's cache it's not only good to user experience, but also for your server.

Remove empty array elements

You can just do

array_filter($array)

array_filter: "If no callback is supplied, all entries of input equal to FALSE will be removed." This means that elements with values NULL, 0, '0', '', FALSE, array() will be removed too.

The other option is doing

array_diff($array, array(''))

which will remove elements with values NULL, '' and FALSE.

Hope this helps :)

UPDATE

Here is an example.

$a = array(0, '0', NULL, FALSE, '', array());

var_dump(array_filter($a));
// array()

var_dump(array_diff($a, array(0))) // 0 / '0'
// array(NULL, FALSE, '', array());

var_dump(array_diff($a, array(NULL))) // NULL / FALSE / ''
// array(0, '0', array())

To sum up:

  • 0 or '0' will remove 0 and '0'
  • NULL, FALSE or '' will remove NULL, FALSE and ''

What are the main performance differences between varchar and nvarchar SQL Server data types?

There'll be exceptional instances when you'll want to deliberately restrict the data type to ensure it doesn't contain characters from a certain set. For example, I had a scenario where I needed to store the domain name in a database. Internationalisation for domain names wasn't reliable at the time so it was better to restrict the input at the base level, and help to avoid any potential issues.

Find control by name from Windows Forms controls

You can use:

f.Controls[name];

Where f is your form variable. That gives you the control with name name.

How to convert int to date in SQL Server 2008

You have to first convert it into datetime, then to date.

Try this, it might be helpful:

Select Convert(DATETIME, LEFT(20130101, 8))

then convert to date.

How to get Database Name from Connection String using SqlConnectionStringBuilder

You can use InitialCatalog Property or builder["Database"] works as well. I tested it with different case and it still works.

Run a single test method with maven

As of surefire plugin version 2.22.1 (possibly earlier) you can run single test using testnames property when using testng.xml

Given a following testng.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd">
<suite name="Suite">
    <test name="all-tests">
        <classes>
            <class name="server.Atest"/>
            <class name="server.Btest"/>
            <class name="server.Ctest"/>
        </classes>
    </test>
    <test name="run-A-test">
        <classes>
            <class name="server.Atest"/>
        </classes>
    </test>
    <test name="run-B-test">
        <classes>
            <class name="server.Btest"/>
        </classes>
    </test>
    <test name="run-C-test">
        <classes>
            <class name="server.Ctest"/>
        </classes>
    </test>
</suite> 

with the pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    [...]
    <properties>
        <selectedTests>all-tests</selectedTests>
    </properties>
    [...]
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>2.22.1</version>
            <configuration>
                <suiteXmlFiles>
                    <file>src/test/resources/testng.xml</file>
                </suiteXmlFiles>
                <properties>
                    <property>
                        <name>testnames</name>
                        <value>${selectedTests}</value>
                    </property>
                </properties>
            </configuration>
        </plugin>
    </plugins>
    [...]
</project>

From command line

mvn clean test -DselectedTests=run-B-test

Further reading - Maven surefire plugin using testng

Basic Python client socket example

Here is a pretty simple socket program. This is about as simple as sockets get.

for the client program(CPU 1)

import socket

s = socket.socket()
host = '111.111.0.11' # needs to be in quote
port = 1247
s.connect((host, port))
print s.recv(1024)
inpt = raw_input('type anything and click enter... ')
s.send(inpt)
print "the message has been sent"

You have to replace the 111.111.0.11 in line 4 with the IP number found in the second computers network settings.

For the server program(CPU 2)

import socket

s = socket.socket()
host = socket.gethostname()
port = 1247
s.bind((host,port))
s.listen(5)
while True:
    c, addr = s.accept()
    print("Connection accepted from " + repr(addr[1]))

    c.send("Server approved connection\n")
    print repr(addr[1]) + ": " + c.recv(1026)
    c.close()

Run the server program and then the client one.

How to add a new audio (not mixing) into a video using ffmpeg?

Nothing quite worked for me (I think it was because my input .mp4 video didn't had any audio) so I found this worked for me:

ffmpeg -i input_video.mp4 -i balipraiavid.wav -map 0:v:0 -map 1:a:0 output.mp4

Visual Studio Code: Auto-refresh file changes

{
    "files.useExperimentalFileWatcher" : true
}

in Code -> Preferences -> Settings

Tested with Visual Studio Code Version 1.26.1 on mac and win

Converting string from snake_case to CamelCase in Ruby

I feel a little uneasy to add more answers here. Decided to go for the most readable and minimal pure ruby approach, disregarding the nice benchmark from @ulysse-bn. While :class mode is a copy of @user3869936, the :method mode I don't see in any other answer here.

  def snake_to_camel_case(str, mode: :class)
    case mode
    when :class
      str.split('_').map(&:capitalize).join
    when :method
      str.split('_').inject { |m, p| m + p.capitalize }
    else
      raise "unknown mode #{mode.inspect}"
    end
  end

Result is:

[28] pry(main)> snake_to_camel_case("asd_dsa_fds", mode: :class)
=> "AsdDsaFds"
[29] pry(main)> snake_to_camel_case("asd_dsa_fds", mode: :method)
=> "asdDsaFds"

Best way to copy a database (SQL Server 2008)

Easiest way is actually a script.

Run this on production:

USE MASTER;

BACKUP DATABASE [MyDatabase]
TO DISK = 'C:\temp\MyDatabase1.bak' -- some writeable folder. 
WITH COPY_ONLY

This one command makes a complete backup copy of the database onto a single file, without interfering with production availability or backup schedule, etc.

To restore, just run this on your dev or test SQL Server:

USE MASTER;

RESTORE DATABASE [MyDatabase]
FROM DISK = 'C:\temp\MyDatabase1.bak'
WITH
MOVE 'MyDatabase'   TO 'C:\Sql\MyDatabase.mdf', -- or wherever these live on target
MOVE 'MyDatabase_log'   TO 'C:\Sql\MyDatabase_log.ldf',
REPLACE, RECOVERY

Then save these scripts on each server. One-click convenience.

Edit:
if you get an error when restoring that the logical names don't match, you can get them like this:

RESTORE FILELISTONLY
FROM disk = 'C:\temp\MyDatabaseName1.bak'

If you use SQL Server logins (not windows authentication) you can run this after restoring each time (on the dev/test machine):

use MyDatabaseName;
sp_change_users_login 'Auto_Fix', 'userloginname', null, 'userpassword';

Java project in Eclipse: The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files

This is an annoying Eclipse Bug which seems to bite now and then. See http://dev-answers.blogspot.de/2009/06/eclipse-build-errors-javalangobject.html for a possible solution, otherwise try the following;

  • Close the project and reopen it.

  • Clean the project (It will rebuild the buildpath hence reconfiguring with the JDK libraries)

    OR

  • Delete and Re-import the project and if necessary do the above steps again.

The better cure is to try NetBeans instead of Eclipse :-)

What is the difference between Tomcat, JBoss and Glassfish?

Both JBoss and Tomcat are Java servlet application servers, but JBoss is a whole lot more. The substantial difference between the two is that JBoss provides a full Java Enterprise Edition (Java EE) stack, including Enterprise JavaBeans and many other technologies that are useful for developers working on enterprise Java applications.

Tomcat is much more limited. One way to think of it is that JBoss is a Java EE stack that includes a servlet container and web server, whereas Tomcat, for the most part, is a servlet container and web server.

Swift: print() vs println() vs NSLog()

To add to Rob's answer, since iOS 10.0, Apple has introduced an entirely new "Unified Logging" system that supersedes existing logging systems (including ASL and Syslog, NSLog), and also surpasses existing logging approaches in performance, thanks to its new techniques including log data compression and deferred data collection.

From Apple:

The unified logging system provides a single, efficient, performant API for capturing messaging across all levels of the system. This unified system centralizes the storage of log data in memory and in a data store on disk.

Apple highly recommends using os_log going forward to log all kinds of messages, including info, debug, error messages because of its much improved performance compared to previous logging systems, and its centralized data collection allowing convenient log and activity inspection for developers. In fact, the new system is likely so low-footprint that it won't cause the "observer effect" where your bug disappears if you insert a logging command, interfering the timing of the bug to happen.

Performance of Activity Tracing, now part of the new Unified Logging system

You can learn more about this in details here.

To sum it up: use print() for your personal debugging for convenience (but the message won't be logged when deployed on user devices). Then, use Unified Logging (os_log) as much as possible for everything else.

Curl error 60, SSL certificate issue: self signed certificate in certificate chain

Answers suggesting to disable CURLOPT_SSL_VERIFYPEER should not be accepted. The question is "Why doesn't it work with cURL", and as correctly pointed out by Martijn Hols, it is dangerous.

The error is probably caused by not having an up-to-date bundle of CA root certificates. This is typically a text file with a bunch of cryptographic signatures that curl uses to verify a host’s SSL certificate.

You need to make sure that your installation of PHP has one of these files, and that it’s up to date (otherwise download one here: http://curl.haxx.se/docs/caextract.html).

Then set in php.ini:

curl.cainfo = <absolute_path_to> cacert.pem

If you are setting it at runtime, use:

curl_setopt ($ch, CURLOPT_CAINFO, dirname(__FILE__)."/cacert.pem");

How to yum install Node.JS on Amazon Linux

Simple install with NVM...

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.34.0/install.sh | bash
. ~/.nvm/nvm.sh
nvm install node

To install a certain version (such as 12.16.3) of Node change the last line to

nvm install 12.16.3

For more information about how to use NVM visit the docs: https://github.com/nvm-sh/nvm

Questions every good Database/SQL developer should be able to answer

Knowing not to use, and WHY not to use:

SELECT *

How to prevent form from being submitted?

Try this one...

HTML Code

<form class="submit">
    <input type="text" name="text1"/>
    <input type="text" name="text2"/>
    <input type="submit" name="Submit" value="submit"/>
</form>

jQuery Code

$(function(){
    $('.submit').on('submit', function(event){
        event.preventDefault();
        alert("Form Submission stopped.");
    });
});

or

$(function(){
    $('.submit').on('submit', function(event){
       event.preventDefault();
       event.stopPropagation();
       alert("Form Submission prevented / stopped.");
    });
});

What's the difference between using CGFloat and float?

As others have said, CGFloat is a float on 32-bit systems and a double on 64-bit systems. However, the decision to do that was inherited from OS X, where it was made based on the performance characteristics of early PowerPC CPUs. In other words, you should not think that float is for 32-bit CPUs and double is for 64-bit CPUs. (I believe, Apple's ARM processors were able to process doubles long before they went 64-bit.) The main performance hit of using doubles is that they use twice the memory and therefore might be slower if you are doing a lot of floating point operations.

Javascript decoding html entities

Using jQuery the easiest will be:

var text = '&lt;p&gt;name&lt;/p&gt;&lt;p&gt;&lt;span style="font-size:xx-small;"&gt;ajde&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;em&gt;da&lt;/em&gt;&lt;/p&gt;';

var output = $("<div />").html(text).text();
console.log(output);

DEMO: http://jsfiddle.net/LKGZx/

Angular 2 http post params and body

Yes the problem is here. It's related to your syntax.

Try using this

return this.http.post(this.BASE_URL, params, options)
  .map(data => this.handleData(data))
  .catch(this.handleError);

instead of

return this.http.post(this.BASE_URL, params, options)
  .map(this.handleData)
  .catch(this.handleError);

Also, the second parameter is supposed to be the body, not the url params.

How to configure a HTTP proxy for svn

Have you seen the FAQ entry What if I'm behind a proxy??

... edit your "servers" configuration file to indicate which proxy to use. The files location depends on your operating system. On Linux or Unix it is located in the directory "~/.subversion". On Windows it is in "%APPDATA%\Subversion". (Try "echo %APPDATA%", note this is a hidden directory.)

For me this involved uncommenting and setting the following lines:

#http-proxy-host=my.proxy
#http-proxy-port=80
#http-proxy-username=[username]
#http-proxy-password=[password]

On command line : nano ~/.subversion/servers

angularjs directive call function specified in attribute and pass an argument to it

This should work.

<div my-method='theMethodToBeCalled'></div>

app.directive("myMethod",function($parse) {
  restrict:'A',
  scope: {theMethodToBeCalled: "="}
  link:function(scope,element,attrs) {
     $(element).on('theEvent',function( e, rowid ) {
        id = // some function called to determine id based on rowid
        scope.theMethodToBeCalled(id);
     }
  }
}

app.controller("myController",function($scope) {
   $scope.theMethodToBeCalled = function(id) { alert(id); };
}

Can you use a trailing comma in a JSON object?

Use JSON5. Don't use JSON.

  • Objects and arrays can have trailing commas
  • Object keys can be unquoted if they're valid identifiers
  • Strings can be single-quoted
  • Strings can be split across multiple lines
  • Numbers can be hexadecimal (base 16)
  • Numbers can begin or end with a (leading or trailing) decimal point.
  • Numbers can include Infinity and -Infinity.
  • Numbers can begin with an explicit plus (+) sign.
  • Both inline (single-line) and block (multi-line) comments are allowed.

http://json5.org/

https://github.com/aseemk/json5

Can I concatenate multiple MySQL rows into one field?

For somebody looking here how to use GROUP_CONCAT with subquery - posting this example

SELECT i.*,
(SELECT GROUP_CONCAT(userid) FROM favourites f WHERE f.itemid = i.id) AS idlist
FROM items i
WHERE i.id = $someid

So GROUP_CONCAT must be used inside the subquery, not wrapping it.

Getting "The remote certificate is invalid according to the validation procedure" when SMTP server has a valid certificate

Old post but as you said "why is it not using the correct certificate" I would like to offer an way to find out which SSL certificate is used for SMTP (see here) which required openssl:

openssl s_client -connect exchange01.int.contoso.com:25 -starttls smtp

This will outline the used SSL certificate for the SMTP service. Based on what you see here you can replace the wrong certificate (like you already did) with a correct one (or trust the certificate manually).

Extract Month and Year From Date in R

Use substring?

d = "2004-02-06"
substr(d,0,7)
>"2004-02"

Is there a way since (iOS 7's release) to get the UDID without using iTunes on a PC/Mac?

Plug it in, and run this from the command line:

system_profiler SPUSBDataType

Look for:

Serial Number: xxxx

How to list the properties of a JavaScript object?

Since I use underscore.js in almost every project, I would use the keys function:

var obj = {name: 'gach', hello: 'world'};
console.log(_.keys(obj));

The output of that will be:

['name', 'hello']

How do I see if Wi-Fi is connected on Android?

You can turn WIFI on if it's not activated as the following 1. check WIFI state as answered by @Jason Knight 2. if not activated, activate it don't forget to add WIFI permission in the manifest file

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

Your Java class should be like that

public class TestApp extends Activity {
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    //check WIFI activation
    ConnectivityManager connManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo mWifi = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);

    if (mWifi.isConnected() == false) {
        showWIFIDisabledAlertToUser();
    }
    else {
        Toast.makeText(this, "WIFI is Enabled in your devide", Toast.LENGTH_SHORT).show();
    }
}


private void showWIFIDisabledAlertToUser(){
    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
    alertDialogBuilder.setMessage("WIFI is disabled in your device. Would you like to enable it?")
            .setCancelable(false)
            .setPositiveButton("Goto Settings Page To Enable WIFI",
                    new DialogInterface.OnClickListener(){
                        public void onClick(DialogInterface dialog, int id){
                            Intent callGPSSettingIntent = new Intent(
                                    Settings.ACTION_WIFI_SETTINGS);
                            startActivity(callGPSSettingIntent);
                        }
                    });
    alertDialogBuilder.setNegativeButton("Cancel",
            new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int id){
                    dialog.cancel();
                }
            });
    AlertDialog alert = alertDialogBuilder.create();
    alert.show();
}

}

Should I use Java's String.format() if performance is important?

Generally you should use String.Format because it's relatively fast and it supports globalization (assuming you're actually trying to write something that is read by the user). It also makes it easier to globalize if you're trying to translate one string versus 3 or more per statement (especially for languages that have drastically different grammatical structures).

Now if you never plan on translating anything, then either rely on Java's built in conversion of + operators into StringBuilder. Or use Java's StringBuilder explicitly.

Check whether $_POST-value is empty

Change this:

if(isset($_POST['submit'])){

    if(!(isset($_POST['userName']))){
    $username = 'Anonymous';
    }      
    else $username = $_POST['userName'];
}

To this:

if(!empty($_POST['userName'])){
     $username = $_POST['userName'];
}

if(empty($_POST['userName'])){
     $username = 'Anonymous';
}

Using the RUN instruction in a Dockerfile with 'source' does not work

If you are using Docker 1.12 or newer, just use SHELL !

Short Answer:

general:

SHELL ["/bin/bash", "-c"] 

for python vituralenv:

SHELL ["/bin/bash", "-c", "source /usr/local/bin/virtualenvwrapper.sh"]

Long Answer:

from https://docs.docker.com/engine/reference/builder/#shell

SHELL ["executable", "parameters"]

The SHELL instruction allows the default shell used for the shell form of commands to be overridden. The default shell on Linux is ["/bin/sh", "-c"], and on Windows is ["cmd", "/S", "/C"]. The SHELL instruction must be written in JSON form in a Dockerfile.

The SHELL instruction is particularly useful on Windows where there are two commonly used and quite different native shells: cmd and powershell, as well as alternate shells available including sh.

The SHELL instruction can appear multiple times. Each SHELL instruction overrides all previous SHELL instructions, and affects all subsequent instructions. For example:

FROM microsoft/windowsservercore

# Executed as cmd /S /C echo default
RUN echo default

# Executed as cmd /S /C powershell -command Write-Host default
RUN powershell -command Write-Host default

# Executed as powershell -command Write-Host hello
SHELL ["powershell", "-command"]
RUN Write-Host hello

# Executed as cmd /S /C echo hello
SHELL ["cmd", "/S"", "/C"]
RUN echo hello

The following instructions can be affected by the SHELL instruction when the shell form of them is used in a Dockerfile: RUN, CMD and ENTRYPOINT.

The following example is a common pattern found on Windows which can be streamlined by using the SHELL instruction:

...
RUN powershell -command Execute-MyCmdlet -param1 "c:\foo.txt"
...

The command invoked by docker will be:

cmd /S /C powershell -command Execute-MyCmdlet -param1 "c:\foo.txt"

This is inefficient for two reasons. First, there is an un-necessary cmd.exe command processor (aka shell) being invoked. Second, each RUN instruction in the shell form requires an extra powershell -command prefixing the command.

To make this more efficient, one of two mechanisms can be employed. One is to use the JSON form of the RUN command such as:

...
RUN ["powershell", "-command", "Execute-MyCmdlet", "-param1 \"c:\\foo.txt\""]
...

While the JSON form is unambiguous and does not use the un-necessary cmd.exe, it does require more verbosity through double-quoting and escaping. The alternate mechanism is to use the SHELL instruction and the shell form, making a more natural syntax for Windows users, especially when combined with the escape parser directive:

# escape=`

FROM microsoft/nanoserver
SHELL ["powershell","-command"]
RUN New-Item -ItemType Directory C:\Example
ADD Execute-MyCmdlet.ps1 c:\example\
RUN c:\example\Execute-MyCmdlet -sample 'hello world'

Resulting in:

PS E:\docker\build\shell> docker build -t shell .
Sending build context to Docker daemon 4.096 kB
Step 1/5 : FROM microsoft/nanoserver
 ---> 22738ff49c6d
Step 2/5 : SHELL powershell -command
 ---> Running in 6fcdb6855ae2
 ---> 6331462d4300
Removing intermediate container 6fcdb6855ae2
Step 3/5 : RUN New-Item -ItemType Directory C:\Example
 ---> Running in d0eef8386e97


    Directory: C:\


Mode                LastWriteTime         Length Name
----                -------------         ------ ----
d-----       10/28/2016  11:26 AM                Example


 ---> 3f2fbf1395d9
Removing intermediate container d0eef8386e97
Step 4/5 : ADD Execute-MyCmdlet.ps1 c:\example\
 ---> a955b2621c31
Removing intermediate container b825593d39fc
Step 5/5 : RUN c:\example\Execute-MyCmdlet 'hello world'
 ---> Running in be6d8e63fe75
hello world
 ---> 8e559e9bf424
Removing intermediate container be6d8e63fe75
Successfully built 8e559e9bf424
PS E:\docker\build\shell>

The SHELL instruction could also be used to modify the way in which a shell operates. For example, using SHELL cmd /S /C /V:ON|OFF on Windows, delayed environment variable expansion semantics could be modified.

The SHELL instruction can also be used on Linux should an alternate shell be required such as zsh, csh, tcsh and others.

The SHELL feature was added in Docker 1.12.

IEnumerable vs List - What to Use? How do they work?

If all you want to do is enumerate them, use the IEnumerable.

Beware, though, that changing the original collection being enumerated is a dangerous operation - in this case, you will want to ToList first. This will create a new list element for each element in memory, enumerating the IEnumerable and is thus less performant if you only enumerate once - but safer and sometimes the List methods are handy (for instance in random access).

Is there an easy way to reload css without reloading the page?

i now have this:

    function swapStyleSheet() {
        var old = $('#pagestyle').attr('href');
        var newCss = $('#changeCss').attr('href');
        var sheet = newCss +Math.random(0,10);
        $('#pagestyle').attr('href',sheet);
        $('#profile').attr('href',old);
        }
    $("#changeCss").on("click", function(event) { 
        swapStyleSheet();
    } );

make any element in your page with id changeCss with a href attribute with the new css url in it. and a link element with the starting css:

<link id="pagestyle" rel="stylesheet" type="text/css" href="css1.css?t=" />

<img src="click.jpg" id="changeCss" href="css2.css?t=">

Convert Promise to Observable

try this:

import 'rxjs/add/observable/fromPromise';
import { Observable } from "rxjs/Observable";

const subscription = Observable.fromPromise(
    firebase.auth().createUserWithEmailAndPassword(email, password)
);
subscription.subscribe(firebaseUser => /* Do anything with data received */,
                       error => /* Handle error here */);

you can find complete reference to fromPromise operator here.

How to remove first and last character of a string?

this is perfectly working fine

String str = "[wdsd34svdf]";
//String str1 = str.replace("[","").replace("]", "");
String str1 = str.replaceAll("[^a-zA-Z0-9]", "");
System.out.println(str1);


String strr = "[wdsd(340) svdf]";
String strr1 = str.replaceAll("[^a-zA-Z0-9]", "");
System.out.println(strr1);

Difference between 3NF and BCNF in simple terms (must be able to explain to an 8-year old)

The difference between BCNF and 3NF

Using the BCNF definition

If and only if for every one of its dependencies X ? Y, at least one of the following conditions hold:

  • X ? Y is a trivial functional dependency (Y ? X), or
  • X is a super key for schema R

and the 3NF definition

If and only if, for each of its functional dependencies X ? A, at least one of the following conditions holds:

  • X contains A (that is, X ? A is trivial functional dependency), or
  • X is a superkey, or
  • Every element of A-X, the set difference between A and X, is a prime attribute (i.e., each attribute in A-X is contained in some candidate key)

We see the following difference, in simple terms:

  • In BCNF: Every partial key (prime attribute) can only depend on a superkey,

whereas

  • In 3NF: A partial key (prime attribute) can also depend on an attribute that is not a superkey (i.e. another partial key/prime attribute or even a non-prime attribute).

Where

  1. A prime attribute is an attribute found in a candidate key, and
  2. A candidate key is a minimal superkey for that relation, and
  3. A superkey is a set of attributes of a relation variable for which it holds that in all relations assigned to that variable, there are no two distinct tuples (rows) that have the same values for the attributes in this set.Equivalently a superkey can also be defined as a set of attributes of a relation schema upon which all attributes of the schema are functionally dependent. (A superkey always contains a candidate key/a candidate key is always a subset of a superkey. You can add any attribute in a relation to obtain one of the superkeys.)

That is, no partial subset (any non trivial subset except the full set) of a candidate key can be functionally dependent on anything other than a superkey.

A table/relation not in BCNF is subject to anomalies such as the update anomalies mentioned in the pizza example by another user. Unfortunately,

  • BNCF cannot always be obtained, while
  • 3NF can always be obtained.

3NF Versus BCNF Example

An example of the difference can currently be found at "3NF table not meeting BCNF (Boyce–Codd normal form)" on Wikipedia, where the following table meets 3NF but not BCNF because "Tennis Court" (a partial key/prime attribute) depends on "Rate Type" (a partial key/prime attribute that is not a superkey), which is a dependency we could determine by asking the clients of the database, the tennis club:

Today's Tennis Court Bookings (3NF, not BCNF)

Court   Start Time  End Time    Rate Type
------- ----------  --------    ---------
1       09:30       10:30       SAVER
1       11:00       12:00       SAVER
1       14:00       15:30       STANDARD
2       10:00       11:30       PREMIUM-B
2       11:30       13:30       PREMIUM-B
2       15:00       16:30       PREMIUM-A

The table's superkeys are:

S1 = {Court, Start Time}
S2 = {Court, End Time}
S3 = {Rate Type, Start Time}
S4 = {Rate Type, End Time}
S5 = {Court, Start Time, End Time}
S6 = {Rate Type, Start Time, End Time}
S7 = {Court, Rate Type, Start Time}
S8 = {Court, Rate Type, End Time}
ST = {Court, Rate Type, Start Time, End Time}, the trivial superkey

The 3NF problem: The partial key/prime attribute "Court" is dependent on something other than a superkey. Instead, it is dependent on the partial key/prime attribute "Rate Type". This means that the user must manually change the rate type if we upgrade a court, or manually change the court if wanting to apply a rate change.

  • But what if the user upgrades the court but does not remember to increase the rate? Or what if the wrong rate type is applied to a court?

(In technical terms, we cannot guarantee that the "Rate Type" -> "Court" functional dependency will not be violated.)

The BCNF solution: If we want to place the above table in BCNF we can decompose the given relation/table into the following two relations/tables (assuming we know that the rate type is dependent on only the court and membership status, which we could discover by asking the clients of our database, the owners of the tennis club):

Rate Types (BCNF and the weaker 3NF, which is implied by BCNF)

Rate Type   Court   Member Flag
---------   -----   -----------
SAVER       1       Yes
STANDARD    1       No
PREMIUM-A   2       Yes
PREMIUM-B   2       No

Today's Tennis Court Bookings (BCNF and the weaker 3NF, which is implied by BCNF)

Member Flag     Court     Start Time   End Time
-----------     -----     ----------   --------
Yes             1         09:30        10:30
Yes             1         11:00        12:00
No              1         14:00        15:30
No              2         10:00        11:30
No              2         11:30        13:30
Yes             2         15:00        16:30

Problem Solved: Now if we upgrade the court we can guarantee the rate type will reflect this change, and we cannot charge the wrong price for a court.

(In technical terms, we can guarantee that the functional dependency "Rate Type" -> "Court" will not be violated.)

What does -1 mean in numpy reshape?

Long story short: you set some dimensions and let NumPy set the remaining(s).

(userDim1, userDim2, ..., -1) -->>

(userDim1, userDim1, ..., TOTAL_DIMENSION - (userDim1 + userDim2 + ...))

C# Select elements in list as List of string

List<string> empnames = (from e in emplist select e.Enaame).ToList();

Or

string[] empnames = (from e in emplist select e.Enaame).ToArray();

Etc...

How to pass anonymous types as parameters?

Unfortunately, what you're trying to do is impossible. Under the hood, the query variable is typed to be an IEnumerable of an anonymous type. Anonymous type names cannot be represented in user code hence there is no way to make them an input parameter to a function.

Your best bet is to create a type and use that as the return from the query and then pass it into the function. For example,

struct Data {
  public string ColumnName; 
}

var query = (from name in some.Table
            select new Data { ColumnName = name });
MethodOp(query);
...
MethodOp(IEnumerable<Data> enumerable);

In this case though, you are only selecting a single field, so it may be easier to just select the field directly. This will cause the query to be typed as an IEnumerable of the field type. In this case, column name.

var query = (from name in some.Table select name);  // IEnumerable<string>

Declare an array in TypeScript

Specific type of array in typescript

export class RegisterFormComponent 
{
     genders = new Array<GenderType>();   // Use any array supports different kind objects

     loadGenders()
     {
        this.genders.push({name: "Male",isoCode: 1});
        this.genders.push({name: "FeMale",isoCode: 2});
     }
}

type GenderType = { name: string, isoCode: number };    // Specified format

Change image source in code behind - Wpf

You just need one line:

ImageViewer1.Source = new BitmapImage(new Uri(@"\myserver\folder1\Customer Data\sample.png"));

How do you get total amount of RAM the computer has?

// use `/ 1048576` to get ram in MB
// and `/ (1048576 * 1024)` or `/ 1048576 / 1024` to get ram in GB
private static String getRAMsize()
{
    ManagementClass mc = new ManagementClass("Win32_ComputerSystem");
    ManagementObjectCollection moc = mc.GetInstances();
    foreach (ManagementObject item in moc)
    {
       return Convert.ToString(Math.Round(Convert.ToDouble(item.Properties["TotalPhysicalMemory"].Value) / 1048576, 0)) + " MB";
    }

    return "RAMsize";
}

MySQL query to get column names?

I have tried this query in SQL Server and this worked for me :

SELECT name FROM sys.columns WHERE OBJECT_ID = OBJECT_ID('table_name')

Allow multi-line in EditText view in Android?

By default all the EditText widgets in Android are multi-lined.

Here is some sample code:

<EditText
    android:inputType="textMultiLine" <!-- Multiline input -->
    android:lines="8" <!-- Total Lines prior display -->
    android:minLines="6" <!-- Minimum lines -->
    android:gravity="top|left" <!-- Cursor Position -->
    android:maxLines="10" <!-- Maximum Lines -->
    android:layout_height="wrap_content" <!-- Height determined by content -->
    android:layout_width="match_parent" <!-- Fill entire width -->
    android:scrollbars="vertical" <!-- Vertical Scroll Bar -->
/>

Convert a PHP object to an associative array

I think it is a nice idea to use traits to store object-to-array converting logic. A simple example:

trait ArrayAwareTrait
{
    /**
     * Return list of Entity's parameters
     * @return array
     */
    public function toArray()
    {
        $props = array_flip($this->getPropertiesList());
        return array_map(
            function ($item) {
                if ($item instanceof \DateTime) {
                    return $item->format(DATE_ATOM);
                }
                return $item;
            },
            array_filter(get_object_vars($this), function ($key) use ($props) {
                return array_key_exists($key, $props);
            }, ARRAY_FILTER_USE_KEY)
        );
    }


    /**
     * @return array
     */
    protected function getPropertiesList()
    {
        if (method_exists($this, '__sleep')) {
            return $this->__sleep();
        }
        if (defined('static::PROPERTIES')) {
            return static::PROPERTIES;
        }
        return [];
    }
}

class OrderResponse
{
    use ArrayAwareTrait;

    const PROP_ORDER_ID = 'orderId';
    const PROP_TITLE = 'title';
    const PROP_QUANTITY = 'quantity';
    const PROP_BUYER_USERNAME = 'buyerUsername';
    const PROP_COST_VALUE = 'costValue';
    const PROP_ADDRESS = 'address';

    private $orderId;
    private $title;
    private $quantity;
    private $buyerUsername;
    private $costValue;
    private $address;

    /**
     * @param $orderId
     * @param $title
     * @param $quantity
     * @param $buyerUsername
     * @param $costValue
     * @param $address
     */
    public function __construct(
        $orderId,
        $title,
        $quantity,
        $buyerUsername,
        $costValue,
        $address
    ) {
        $this->orderId = $orderId;
        $this->title = $title;
        $this->quantity = $quantity;
        $this->buyerUsername = $buyerUsername;
        $this->costValue = $costValue;
        $this->address = $address;
    }

    /**
     * @inheritDoc
     */
    public function __sleep()
    {
        return [
            static::PROP_ORDER_ID,
            static::PROP_TITLE,
            static::PROP_QUANTITY,
            static::PROP_BUYER_USERNAME,
            static::PROP_COST_VALUE,
            static::PROP_ADDRESS,
        ];
    }

    /**
     * @return mixed
     */
    public function getOrderId()
    {
        return $this->orderId;
    }

    /**
     * @return mixed
     */
    public function getTitle()
    {
        return $this->title;
    }

    /**
     * @return mixed
     */
    public function getQuantity()
    {
        return $this->quantity;
    }

    /**
     * @return mixed
     */
    public function getBuyerUsername()
    {
        return $this->buyerUsername;
    }

    /**
     * @return mixed
     */
    public function getCostValue()
    {
        return $this->costValue;
    }

    /**
     * @return string
     */
    public function getAddress()
    {
        return $this->address;
    }
}

$orderResponse = new OrderResponse(...);
var_dump($orderResponse->toArray());

How to read a CSV file into a .NET Datatable

I came across this piece of code that uses Linq and regex to parse a CSV file. The refering article is now over a year and a half old, but have not come across a neater way to parse a CSV using Linq (and regex) than this. The caveat is the regex applied here is for comma delimited files (will detect commas inside quotes!) and that it may not take well to headers, but there is a way to overcome these). Take a peak:

Dim lines As String() = System.IO.File.ReadAllLines(strCustomerFile)
Dim pattern As String = ",(?=(?:[^""]*""[^""]*"")*(?![^""]*""))"
Dim r As System.Text.RegularExpressions.Regex = New System.Text.RegularExpressions.Regex(pattern)
Dim custs = From line In lines _
            Let data = r.Split(line) _
                Select New With {.custnmbr = data(0), _
                                 .custname = data(1)}
For Each cust In custs
    strCUSTNMBR = Replace(cust.custnmbr, Chr(34), "")
    strCUSTNAME = Replace(cust.custname, Chr(34), "")
Next

.prop('checked',false) or .removeAttr('checked')?

Another alternative to do the same thing is to filter on type=checkbox attribute:

$('input[type="checkbox"]').removeAttr('checked');

or

$('input[type="checkbox"]').prop('checked' , false);

Remeber that The difference between attributes and properties can be important in specific situations. Before jQuery 1.6, the .attr() method sometimes took property values into account when retrieving some attributes, which could cause inconsistent behavior. As of jQuery 1.6, the .prop() method provides a way to explicitly retrieve property values, while .attr() retrieves attributes.

Know more...

T-SQL Format integer to 2-digit string

You could try this

SELECT RIGHT( '0' + convert( varchar(2) , '0' ),  2 ) -- OUTPUTS : 00
SELECT RIGHT( '0' + convert( varchar(2) , '8' ),  2 ) -- OUTPUTS : 08
SELECT RIGHT( '0' + convert( varchar(2) , '9' ),  2 ) -- OUTPUTS : 09
SELECT RIGHT( '0' + convert( varchar(2) , '10' ), 2 ) -- OUTPUTS : 10
SELECT RIGHT( '0' + convert( varchar(2) , '11' ), 2 ) -- OUTPUTS : 11

this should help

Concatenating multiple text files into a single file in Bash

Just remember, for all the solutions given so far, the shell decides the order in which the files are concatenated. For Bash, IIRC, that's alphabetical order. If the order is important, you should either name the files appropriately (01file.txt, 02file.txt, etc...) or specify each file in the order you want it concatenated.

$ cat file1 file2 file3 file4 file5 file6 > out.txt

Sys is undefined

When I experienced the errors

  • Sys is undefined
  • ASP.NET Ajax client-side framework failed to load

in IE when using ASP.NET Ajax controls in .NET 2.0, I needed to add the following to the web.config file within the <system.web> tags:

<httpHandlers>
  <remove verb="*" path="*.asmx"/>
  <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
  <add verb="GET" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler" validate="false"/>
</httpHandlers>

Why is exception.printStackTrace() considered bad practice?

Printing the exception's stack trace in itself doesn't constitute bad practice, but only printing the stace trace when an exception occurs is probably the issue here -- often times, just printing a stack trace is not enough.

Also, there's a tendency to suspect that proper exception handling is not being performed if all that is being performed in a catch block is a e.printStackTrace. Improper handling could mean at best an problem is being ignored, and at worst a program that continues executing in an undefined or unexpected state.

Example

Let's consider the following example:

try {
  initializeState();

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

continueProcessingAssumingThatTheStateIsCorrect();

Here, we want to do some initialization processing before we continue on to some processing that requires that the initialization had taken place.

In the above code, the exception should have been caught and properly handled to prevent the program from proceeding to the continueProcessingAssumingThatTheStateIsCorrect method which we could assume would cause problems.

In many instances, e.printStackTrace() is an indication that some exception is being swallowed and processing is allowed to proceed as if no problem every occurred.

Why has this become a problem?

Probably one of the biggest reason that poor exception handling has become more prevalent is due to how IDEs such as Eclipse will auto-generate code that will perform a e.printStackTrace for the exception handling:

try {
  Thread.sleep(1000);
} catch (InterruptedException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
}

(The above is an actual try-catch auto-generated by Eclipse to handle an InterruptedException thrown by Thread.sleep.)

For most applications, just printing the stack trace to standard error is probably not going to be sufficient. Improper exception handling could in many instances lead to an application running in a state that is unexpected and could be leading to unexpected and undefined behavior.

Get a pixel from HTML Canvas?

// Get pixel data
var imageData = context.getImageData(x, y, width, height);

// Color at (x,y) position
var color = [];
color['red'] = imageData.data[((y*(imageData.width*4)) + (x*4)) + 0];
color['green'] = imageData.data[((y*(imageData.width*4)) + (x*4)) + 1];
color['blue'] = imageData.data[((y*(imageData.width*4)) + (x*4)) + 2];
color['alpha'] = imageData.data[((y*(imageData.width*4)) + (x*4)) + 3];

How do I generate a random number between two variables that I have stored?

To generate a random number between min and max, use:

int randNum = rand()%(max-min + 1) + min;

(Includes max and min)

Visual Studio setup problem - 'A problem has been encountered while loading the setup components. Canceling setup.'

Microsoft itself posted a KB article about this, and that article has a service pack that they claim fixes the problem. See below.

http://support.microsoft.com/kb/959417/

It took a while for the associated update to install itself, but once it did, I was able to run the Visual Studio setup successfully from the Add/Remove Programs control panel.

NVIDIA NVML Driver/library version mismatch

Had the issue too. (I'm running ubuntu 18.04)

What I did:

dpkg -l | grep -i nvidia

Then sudo apt-get remove --purge nvidia-381 (and every duplicate version, in my case I had 381, 384 and 387)

Then sudo ubuntu-drivers devices to list what's available

And I choose sudo apt install nvidia-driver-430

After that, nvidia-smi gave the correct output (no need to reboot). But I suppose you can reboot when in doubt.

I also followed this installation to reinstall cuda+cudnn.

Delete from a table based on date

You could use:

DELETE FROM tableName
where your_date_column < '2009-01-01';

but Keep in mind that the above is really

DELETE FROM tableName
    where your_date_column < '2009-01-01 00:00:00';

Not

 DELETE FROM tableName
        where your_date_column < '2009-01-01 11:59';

filtering a list using LINQ

var filtered = projects;
foreach (var tag in filteredTags) {
  filtered = filtered.Where(p => p.Tags.Contains(tag))
}

The nice thing with this approach is that you can refine search results incrementally.

How to dynamically change a web page's title?

One way that comes to mind that may help with SEO and still have your tab pages as they are would be to use named anchors that correspond to each tab, as in:

http://www.example.com/mypage#tab1, http://www.example.com/mypage#tab2, etc.

You would need to have server side processing to parse the url and set the initial page title when the browser renders the page. I would also go ahead and make that tab the "active" one. Once the page is loaded and an actual user is switching tabs you would use javascript to change document.title as other users have stated.

Declare Variable for a Query String

DECLARE @theDate DATETIME
SET @theDate = '2010-01-01'

Then change your query to use this logic:

AND 
(
    tblWO.OrderDate > DATEADD(MILLISECOND, -1, @theDate) 
    AND tblWO.OrderDate < DATEADD(DAY, 1, @theDate)
)

Android Failed to install HelloWorld.apk on device (null) Error

Restarting the device works for me. Using adb install can get the apk installed, but it's annoying to use it everytime you launch the app when debugging within eclipse.

javascript variable reference/alias

edit to my previous answer: if you want to count a function's invocations, you might want to try:

var countMe = ( function() {
  var c = 0;

  return function() {
    c++;
    return c;
  }
})();

alert(countMe()); // Alerts "1"
alert(countMe()); // Alerts "2"

Here, c serves as the counter, and you do not have to use arguments.callee.

Android Respond To URL in Intent

You might need to allow different combinations of data in your intent filter to get it to work in different cases (http/ vs https/, www. vs no www., etc).

For example, I had to do the following for an app which would open when the user opened a link to Google Drive forms (www.docs.google.com/forms)

Note that path prefix is optional.

        <intent-filter>
            <action android:name="android.intent.action.VIEW" />
            <category android:name="android.intent.category.DEFAULT" />
            <category android:name="android.intent.category.BROWSABLE" />

            <data android:scheme="http" />
            <data android:scheme="https" />

            <data android:host="www.docs.google.com" />
            <data android:host="docs.google.com" />

            <data android:pathPrefix="/forms" />
        </intent-filter>

java.net.SocketException: Connection reset by peer: socket write error When serving a file

This problem is usually caused by writing to a connection that had already been closed by the peer. In this case it could indicate that the user cancelled the download for example.

What are ODEX files in Android?

ART

According to the docs: http://web.archive.org/web/20170909233829/https://source.android.com/devices/tech/dalvik/configure an .odex file:

contains AOT compiled code for methods in the APK.

Furthermore, they appear to be regular shared libraries, since if you get any app, and check:

file /data/app/com.android.appname-*/oat/arm64/base.odex

it says:

base.odex: ELF shared object, 64-bit LSB arm64, stripped

and aarch64-linux-gnu-objdump -d base.odex seems to work and give some meaningful disassembly (but also some rubbish sections).

Selecting a row in DataGridView programmatically

 <GridViewName>.ClearSelection(); ----------------------------------------------------1
 foreach(var item in itemList) -------------------------------------------------------2
 {
    rowHandle =<GridViewName>.LocateByValue("UniqueProperty_Name", item.unique_id );--3
    if (rowHandle != GridControl.InvalidRowHandle)------------------------------------4
    {
        <GridViewName>.SelectRow(rowHandle);------------------------------------ -----5
    }
  }
  1. Clear all previous selection.
  2. Loop through rows needed to be selected in your grid.
  3. Get their row handles from grid (Note here grid is already updated with new rows)
  4. Checking if the row handle is valid or not.
  5. When valid row handle then select it.

Where itemList is list of rows to be selected in the grid view.

Why is this program erroneously rejected by three C++ compilers?

I've found it helps to not write my code on my monitor's glass with a magic marker, even though it looks nice when its really black. The screen fills up too fast and then the people who give me a clean monitor call me names each week.

A couple of my employees (I'm a manager) are chipping in to buy me one of those red pad computers with the knobs. They said that I won't need markers and I can clean the screen myself when it's full but I have to be careful shaking it. I supposed it's delicate that way.

That's why I hire the smart people.

What is the function of the push / pop instructions used on registers in x86 assembly?

Where is it pushed on?

esp - 4. More precisely:

  • esp gets subtracted by 4
  • the value is pushed to esp

pop reverses this.

The System V ABI tells Linux to make rsp point to a sensible stack location when the program starts running: What is default register state when program launches (asm, linux)? which is what you should usually use.

How can you push a register?

Minimal GNU GAS example:

.data
    /* .long takes 4 bytes each. */
    val1:
        /* Store bytes 0x 01 00 00 00 here. */
        .long 1
    val2:
        /* 0x 02 00 00 00 */
        .long 2
.text
    /* Make esp point to the address of val2.
     * Unusual, but totally possible. */
    mov $val2, %esp

    /* eax = 3 */
    mov $3, %ea 

    push %eax
    /*
    Outcome:
    - esp == val1
    - val1 == 3
    esp was changed to point to val1,
    and then val1 was modified.
    */

    pop %ebx
    /*
    Outcome:
    - esp == &val2
    - ebx == 3
    Inverses push: ebx gets the value of val1 (first)
    and then esp is increased back to point to val2.
    */

The above on GitHub with runnable assertions.

Why is this needed?

It is true that those instructions could be easily implemented via mov, add and sub.

They reason they exist, is that those combinations of instructions are so frequent, that Intel decided to provide them for us.

The reason why those combinations are so frequent, is that they make it easy to save and restore the values of registers to memory temporarily so they don't get overwritten.

To understand the problem, try compiling some C code by hand.

A major difficulty, is to decide where each variable will be stored.

Ideally, all variables would fit into registers, which is the fastest memory to access (currently about 100x faster than RAM).

But of course, we can easily have more variables than registers, specially for the arguments of nested functions, so the only solution is to write to memory.

We could write to any memory address, but since the local variables and arguments of function calls and returns fit into a nice stack pattern, which prevents memory fragmentation, that is the best way to deal with it. Compare that with the insanity of writing a heap allocator.

Then we let compilers optimize the register allocation for us, since that is NP complete, and one of the hardest parts of writing a compiler. This problem is called register allocation, and it is isomorphic to graph coloring.

When the compiler's allocator is forced to store things in memory instead of just registers, that is known as a spill.

Does this boil down to a single processor instruction or is it more complex?

All we know for sure is that Intel documents a push and a pop instruction, so they are one instruction in that sense.

Internally, it could be expanded to multiple microcodes, one to modify esp and one to do the memory IO, and take multiple cycles.

But it is also possible that a single push is faster than an equivalent combination of other instructions, since it is more specific.

This is mostly un(der)documented:

How to utilize date add function in Google spreadsheet?

In a fresh spreadsheet (US locale) with 12/19/11 in A1 and DT 30 in B1 then:

=A1+right(B1,2)

in say C1 returns 1/18/12.

As a string function RIGHT returns Text but that can be coerced into a number when adding. In adding a number to dates unity is treated as one day. Within (very wide) limits, months and even years are adjusted automatically.

XAMPP PORT 80 is Busy / EasyPHP error in Apache configuration file:

xampp port 80 is busy when some other application is using the same port at that time. This can be solved by using one of the following methods:

  1. Detect the application which is using the port 80 and close it.
  2. This one is more efficient. xampp installs apache server with default port 80. So, you can change this port manually to any number.

Just find the httpd.conf file in xampp installation and replace the following line of code.

#Listen 12.34.56.78:1234
Listen 80

to any port number of your choice. Here, i have taken 8000.

#Listen 12.34.56.78:1234
Listen 8000

Find the following code in the same file httpd.conf

ServerName localhost

Replace with the following, take the same number you have used in upper code.

ServerName localhost:8000

For detailed answer, check http://webolute.com/blog/programming/this-may-be-due-to-a-blocked-port-missing-dependencies

How do I reset the setInterval timer?

Once you clear the interval using clearInterval you could setInterval once again. And to avoid repeating the callback externalize it as a separate function:

var ticker = function() {
    console.log('idle');
};

then:

var myTimer = window.setInterval(ticker, 4000);

then when you decide to restart:

window.clearInterval(myTimer);
myTimer = window.setInterval(ticker, 4000);

Convert a string to integer with decimal in Python

>>> s = '23.45678'
>>> int(float(s))
23
>>> int(round(float(s)))
23
>>> s = '23.54678'
>>> int(float(s))
23
>>> int(round(float(s)))
24

You don't specify if you want rounding or not...

how to set the default value to the drop down list control?

After your DataBind():

lstDepartment.SelectedIndex = 0;  //first item

or

lstDepartment.SelectedValue = "Yourvalue"

or 
//add error checking, just an example, FindByValue may return null
lstDepartment.Items.FindByValue("Yourvalue").Selected = true;

or
//add error checking, just an example, FindByText may return null
lstDepartment.Items.FindByText("Yourvalue").Selected = true;

Find and replace strings in vim on multiple lines

As a side note, instead of having to type in the line numbers, just highlight the lines where you want to find/replace in one of the visual modes:

  • VISUAL mode (V)
  • VISUAL BLOCK mode (Ctrl+V)
  • VISUAL LINE mode (Shift+V, works best in your case)

Once you selected the lines to replace, type your command:

:s/<search_string>/<replace_string>/g

You'll note that the range '<,'> will be inserted automatically for you:

:'<,'>s/<search_string>/<replace_string>/g

Here '< simply means first highlighted line, and '> means last highlighted line.

Note that the behaviour might be unexpected when in NORMAL mode: '< and '> point to the start and end of the last highlight done in one of the VISUAL modes. Instead, in NORMAL mode, the special line number . can be used, which simply means current line. Hence, you can find/replace only on the current line like this:

:.s/<search_string>/<replace_string>/g

Another thing to note is that inserting a second : between the range and the find/replace command does no harm, in other words, these commands will still work:

:'<,'>:s/<search_string>/<replace_string>/g
:.:s/<search_string>/<replace_string>/g

Bootstrap 3 modal responsive

I had the same issue I have resolved by adding a media query for @screen-xs-min in less version under Modals.less

@media (max-width: @screen-xs-min) {
  .modal-xs { width: @modal-sm; }
}

What's the fastest way in Python to calculate cosine similarity given sparse matrix data?

The following method is about 30 times faster than scipy.spatial.distance.pdist. It works pretty quickly on large matrices (assuming you have enough RAM)

See below for a discussion of how to optimize for sparsity.

# base similarity matrix (all dot products)
# replace this with A.dot(A.T).toarray() for sparse representation
similarity = numpy.dot(A, A.T)


# squared magnitude of preference vectors (number of occurrences)
square_mag = numpy.diag(similarity)

# inverse squared magnitude
inv_square_mag = 1 / square_mag

# if it doesn't occur, set it's inverse magnitude to zero (instead of inf)
inv_square_mag[numpy.isinf(inv_square_mag)] = 0

# inverse of the magnitude
inv_mag = numpy.sqrt(inv_square_mag)

# cosine similarity (elementwise multiply by inverse magnitudes)
cosine = similarity * inv_mag
cosine = cosine.T * inv_mag

If your problem is typical for large scale binary preference problems, you have a lot more entries in one dimension than the other. Also, the short dimension is the one whose entries you want to calculate similarities between. Let's call this dimension the 'item' dimension.

If this is the case, list your 'items' in rows and create A using scipy.sparse. Then replace the first line as indicated.

If your problem is atypical you'll need more modifications. Those should be pretty straightforward replacements of basic numpy operations with their scipy.sparse equivalents.

How do I auto size columns through the Excel interop objects?

Have a look at this article, it's not an exact match to your problem, but suits it:

"End of script output before headers" error in Apache

If this is a CGI script for the web, then you must output your header:

#!"C:\xampp\perl\bin\perl.exe"

print "Content-Type: text/html\n\n";
print "Hello World";

The following error message tells you this End of script output before headers: sample.pl

Or even better, use the CGI module to output the header:

#!"C:\xampp\perl\bin\perl.exe"

use strict;
use warnings;

use CGI;

print CGI::header();
print "Hello World";

Select entries between dates in doctrine 2


    EDIT: See the other answers for better solutions

The original newbie approaches that I offered were (opt1):

$qb->where("e.fecha > '" . $monday->format('Y-m-d') . "'");
$qb->andWhere("e.fecha < '" . $sunday->format('Y-m-d') . "'");

And (opt2):

$qb->add('where', "e.fecha between '2012-01-01' and '2012-10-10'");

That was quick and easy and got the original poster going immediately.

Hence the accepted answer.

As per comments, it is the wrong answer, but it's an easy mistake to make, so I'm leaving it here as a "what not to do!"

AngularJS - value attribute for select

What you first tried should work, but the HTML is not what we would expect. I added an option to handle the initial "no item selected" case:

<select ng-options="region.code as region.name for region in regions" ng-model="region">
   <option style="display:none" value="">select a region</option>
</select>
<br>selected: {{region}}

The above generates this HTML:

<select ng-options="..." ng-model="region" class="...">
   <option style="display:none" value class>select a region</option>
   <option value="0">Alabama</option>
   <option value="1">Alaska</option>
   <option value="2">American Samoa</option>
</select>

Fiddle

Even though Angular uses numeric integers for the value, the model (i.e., $scope.region) will be set to AL, AK, or AS, as desired. (The numeric value is used by Angular to lookup the correct array entry when an option is selected from the list.)

This may be confusing when first learning how Angular implements its "select" directive.

How can I get a JavaScript stack trace when I throw an exception?

It is easier to get a stack trace on Firefox than it is on IE but fundamentally here is what you want to do:

Wrap the "problematic" piece of code in a try/catch block:

try {
    // some code that doesn't work
    var t = null;
    var n = t.not_a_value;
}
    catch(e) {
}

If you will examine the contents of the "error" object it contains the following fields:

e.fileName : The source file / page where the issue came from e.lineNumber : The line number in the file/page where the issue arose e.message : A simple message describing what type of error took place e.name : The type of error that took place, in the example above it should be 'TypeError' e.stack : Contains the stack trace that caused the exception

I hope this helps you out.

How to add a right button to a UINavigationController?

Here is the solution in Swift (set options as needed):

var optionButton = UIBarButtonItem()
optionButton.title = "Settings"
//optionButton.action = something (put your action here)
self.navigationItem.rightBarButtonItem = optionButton

How to unpack pkl file?

The pickle (and gzip if the file is compressed) module need to be used

NOTE: These are already in the standard Python library. No need to install anything new

What is the path for the startup folder in windows 2008 server

In Server 2008 the startup folder for individual users is here:

C:\Users\username\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup

For All Users it's here:

C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup

Hope that helps

Split string and get first value only

You can do it:

var str = "Doctor Who,Fantasy,Steven Moffat,David Tennant";

var title = str.Split(',').First();

Also you can do it this way:

var index = str.IndexOf(",");
var title = index < 0 ? str : str.Substring(0, index);

Python concatenate text files

Check out the .read() method of the File object:

http://docs.python.org/2/tutorial/inputoutput.html#methods-of-file-objects

You could do something like:

concat = ""
for file in files:
    concat += open(file).read()

or a more 'elegant' python-way:

concat = ''.join([open(f).read() for f in files])

which, according to this article: http://www.skymind.com/~ocrow/python_string/ would also be the fastest.

How To fix white screen on app Start up?

This is my AppTheme on an example app:

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <item name="android:windowIsTranslucent">true</item>
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
</style>

As you can see, I have the default colors and then I added the android:windowIsTranslucent and set it to true.

As far as I know as an Android Developer, this is the only thing you need to set in order to hide the white screen on the start of the application.

How to change RGB color to HSV?

Note that Color.GetSaturation() and Color.GetBrightness() return HSL values, not HSV.
The following code demonstrates the difference.

Color original = Color.FromArgb(50, 120, 200);
// original = {Name=ff3278c8, ARGB=(255, 50, 120, 200)}

double hue;
double saturation;
double value;
ColorToHSV(original, out hue, out saturation, out value);
// hue        = 212.0
// saturation = 0.75
// value      = 0.78431372549019607

Color copy = ColorFromHSV(hue, saturation, value);
// copy = {Name=ff3278c8, ARGB=(255, 50, 120, 200)}

// Compare that to the HSL values that the .NET framework provides: 
original.GetHue();        // 212.0
original.GetSaturation(); // 0.6
original.GetBrightness(); // 0.490196079

The following C# code is what you want. It converts between RGB and HSV using the algorithms described on Wikipedia. The ranges are 0 - 360 for hue, and 0 - 1 for saturation or value.

public static void ColorToHSV(Color color, out double hue, out double saturation, out double value)
{
    int max = Math.Max(color.R, Math.Max(color.G, color.B));
    int min = Math.Min(color.R, Math.Min(color.G, color.B));

    hue = color.GetHue();
    saturation = (max == 0) ? 0 : 1d - (1d * min / max);
    value = max / 255d;
}

public static Color ColorFromHSV(double hue, double saturation, double value)
{
    int hi = Convert.ToInt32(Math.Floor(hue / 60)) % 6;
    double f = hue / 60 - Math.Floor(hue / 60);

    value = value * 255;
    int v = Convert.ToInt32(value);
    int p = Convert.ToInt32(value * (1 - saturation));
    int q = Convert.ToInt32(value * (1 - f * saturation));
    int t = Convert.ToInt32(value * (1 - (1 - f) * saturation));

    if (hi == 0)
        return Color.FromArgb(255, v, t, p);
    else if (hi == 1)
        return Color.FromArgb(255, q, v, p);
    else if (hi == 2)
        return Color.FromArgb(255, p, v, t);
    else if (hi == 3)
        return Color.FromArgb(255, p, q, v);
    else if (hi == 4)
        return Color.FromArgb(255, t, p, v);
    else
        return Color.FromArgb(255, v, p, q);
}

How to get the text of the selected value of a dropdown list?

Hi if you are having dropdownlist like this

<select id="testID">
<option value="1">Value1</option>
<option value="2">Value2</option>
<option value="3">Value3</option>
<option value="4">Value4</option>
<option value="5">Value5</option>
<option value="6">Value6</option>
</select>
<input type="button" value="Get dropdown selected Value" onclick="getHTML();">

after giving id to dropdownlist you just need to add jquery code like this

function getHTML()
{
      var display=$('#testID option:selected').html();
      alert(display);
}

Exception : mockito wanted but not invoked, Actually there were zero interactions with this mock

@jk1 answer is perfect, since @igor Ganapolsky asked, why can't we use Mockito.mock here? i post this answer.

For that we have provide one setter method for myobj and set the myobj value with mocked object.

class MyClass {
    MyInterface myObj;

    public void abc() {
        myObj.myMethodToBeVerified (new String("a"), new String("b"));
    }

    public void setMyObj(MyInterface obj)
    {
        this.myObj=obj;
    }
}

In our Test class, we have to write below code

class MyClassTest {

MyClass myClass = new MyClass();

    @Mock
    MyInterface myInterface;

    @test
    testAbc() {
        myclass.setMyObj(myInterface); //it is good to have in @before method
        myClass.abc();
        verify(myInterface).myMethodToBeVerified(new String("a"), new String("b"));
     }
}

How to get an array of specific "key" in multidimensional array without looping

If id is the first key in the array, this'll do:

$ids = array_map('current', $users);

You should not necessarily rely on this though. :)

How do I cancel an HTTP fetch() request?

As of Feb 2018, fetch() can be cancelled with the code below on Chrome (read Using Readable Streams to enable Firefox support). No error is thrown for catch() to pick up, and this is a temporary solution until AbortController is fully adopted.

fetch('YOUR_CUSTOM_URL')
.then(response => {
  if (!response.body) {
    console.warn("ReadableStream is not yet supported in this browser.  See https://developer.mozilla.org/en-US/docs/Web/API/ReadableStream")
    return response;
  }

  // get reference to ReadableStream so we can cancel/abort this fetch request.
  const responseReader = response.body.getReader();
  startAbortSimulation(responseReader);

  // Return a new Response object that implements a custom reader.
  return new Response(new ReadableStream(new ReadableStreamConfig(responseReader)));
})
.then(response => response.blob())
.then(data => console.log('Download ended. Bytes downloaded:', data.size))
.catch(error => console.error('Error during fetch()', error))


// Here's an example of how to abort request once fetch() starts
function startAbortSimulation(responseReader) {
  // abort fetch() after 50ms
  setTimeout(function() {
    console.log('aborting fetch()...');
    responseReader.cancel()
    .then(function() {
      console.log('fetch() aborted');
    })
  },50)
}


// ReadableStream constructor requires custom implementation of start() method
function ReadableStreamConfig(reader) {
  return {
    start(controller) {
      read();
      function read() {
        reader.read().then(({done,value}) => {
          if (done) {
            controller.close();
            return;
          }
          controller.enqueue(value);
          read();
        })
      }
    }
  }
}

get the value of input type file , and alert if empty

<script type="text/javascript">
$(document).ready(function() {
    $('#upload').bind("click",function() 
    { 
        var imgVal = $('#uploadImage').val(); 
        if(imgVal=='') 
        { 
            alert("empty input file"); 

        } 
        return false; 

    }); 
});
</script> 

<input type="file" name="image" id="uploadImage" size="30" /> 
<input type="submit" name="upload" id="upload"  class="send_upload" value="upload" /> 

sqlplus how to find details of the currently connected database session

We can get the details and status of session from below query as:

select ' Sid, Serial#, Aud sid : '|| s.sid||' , '||s.serial#||' , '||
       s.audsid||chr(10)|| '     DB User / OS User : '||s.username||
       '   /   '||s.osuser||chr(10)|| '    Machine - Terminal : '||
       s.machine||'  -  '|| s.terminal||chr(10)||
       '        OS Process Ids : '||
       s.process||' (Client)  '||p.spid||' (Server)'|| chr(10)||
       '   Client Program Name : '||s.program "Session Info"
  from v$process p,v$session s
 where p.addr = s.paddr
   and s.sid = nvl('&SID',s.sid)
   and nvl(s.terminal,' ') = nvl('&Terminal',nvl(s.terminal,' '))
   and s.process = nvl('&Process',s.process)
   and p.spid = nvl('&spid',p.spid)
   and s.username = nvl('&username',s.username)
   and nvl(s.osuser,' ') = nvl('&OSUser',nvl(s.osuser,' '))
   and nvl(s.machine,' ') = nvl('&machine',nvl(s.machine,' '))
   and nvl('&SID',nvl('&TERMINAL',nvl('&PROCESS',nvl('&SPID',nvl('&USERNAME',
       nvl('&OSUSER',nvl('&MACHINE','NO VALUES'))))))) <> 'NO VALUES'
/

For more details: https://ora-data.blogspot.in/2016/11/query-session-details.html

Thanks,