Programs & Examples On #Utility

Utility software is system software designed to help analyze, configure, optimize or maintain a computer. A single piece of utility software is usually called a utility or tool.

Implement touch using Python?

For a more low-level solution one can use

os.close(os.open("file.txt", os.O_CREAT))

Converting newline formatting from Mac to Windows

On Yosemite OSX, use this command:

sed -e 's/^M$//' -i '' filename

where the ^M sequence is achieved by pressing Ctrl+V then Enter.

How can I create an utility class?

Making a class abstract sends a message to the readers of your code that you want users of your abstract class to subclass it. However, this is not what you want then to do: a utility class should not be subclassed.

Therefore, adding a private constructor is a better choice here. You should also make the class final to disallow subclassing of your utility class.

Good tool for testing socket connections?

I would go with netcat too , but since you can't use it , here is an alternative : netcat :). You can find netcat implemented in three languages ( python/ruby/perl ) . All you need to do is install the interpreters for the language you choose . Surely , that won't be viewed as a hacking tool .

Here are the links :

Perl implementation

Python implementation

Ruby Implementation

Java: Static Class?

Sounds like you have a utility class similar to java.lang.Math.
The approach there is final class with private constructor and static methods.

But beware of what this does for testability, I recommend reading this article
Static Methods are Death to Testability

Open a URL without using a browser from a batch file

Try winhttpjs.bat. It uses a winhttp request object that should be faster than
Msxml2.XMLHTTP as there isn't any DOM parsing of the response. It is capable to do requests with body and all HTTP methods.

call winhttpjs.bat  http://somelink.com/something.html -saveTo c:\something.html

Fastest way to get the first n elements of a List into an Array

Option 3

Iterators are faster than using the get operation, since the get operation has to start from the beginning if it has to do some traversal. It probably wouldn't make a difference in an ArrayList, but other data structures could see a noticeable speed difference. This is also compatible with things that aren't lists, like sets.

String[] out = new String[n];
Iterator<String> iterator = in.iterator();
for (int i = 0; i < n && iterator.hasNext(); i++)
    out[i] = iterator.next();

How to redirect to previous page in Ruby On Rails?

I like Jaime's method with one exception, it worked better for me to re-store the referer every time:

def edit
    session[:return_to] = request.referer
...

The reason is that if you edit multiple objects, you will always be redirected back to the first URL you stored in the session with Jaime's method. For example, let's say I have objects Apple and Orange. I edit Apple and session[:return_to] gets set to the referer of that action. When I go to edit Oranges using the same code, session[:return_to] will not get set because it is already defined. So when I update the Orange, I will get sent to the referer of the previous Apple#edit action.

How can I enable the MySQLi extension in PHP 7?

In Ubuntu, you need to uncomment this line in file php.ini which is located at /etc/php/7.0/apache2/php.ini:

extension=php_mysqli.so

This certificate has an invalid issuer Apple Push Services

I think I've figured this one out. I imported the new WWDR Certificate that expires in 2023, but I was still getting problems building and my developer certificates were still showing the invalid issuer error.

  • In keychain access, go to View -> Show Expired Certificates. Then in your login keychain highlight the expired WWDR Certificate and delete it.
  • I also had the same expired certificate in my System keychain, so I deleted it from there too (important).

After deleting the expired certificate from the login and System keychains, I was able to build for Distribution again.

Groovy executing shell commands

"ls".execute() returns a Process object which is why "ls".execute().text works. You should be able to just read the error stream to determine if there were any errors.

There is a extra method on Process that allow you to pass a StringBuffer to retrieve the text: consumeProcessErrorStream(StringBuffer error).

Example:

def proc = "ls".execute()
def b = new StringBuffer()
proc.consumeProcessErrorStream(b)

println proc.text
println b.toString()

clear table jquery

Having a table like this (with a header and a body)

<table id="myTableId">
    <thead>
    </thead>
    <tbody>
   </tbody>
</table>

remove every tr having a parent called tbody inside the #tableId

$('#tableId tbody > tr').remove();

and in reverse if you want to add to your table

$('#tableId tbody').append("<tr><td></td>....</tr>");

Android SDK Setup under Windows 7 Pro 64 bit

You can just push back and push next again, and it installs OK.

How SID is different from Service name in Oracle tnsnames.ora

Quote by @DAC

In short: SID = the unique name of your DB, ServiceName = the alias used when connecting

Not strictly true. SID = unique name of the INSTANCE (eg the oracle process running on the machine). Oracle considers the "Database" to be the files.

Service Name = alias to an INSTANCE (or many instances). The main purpose of this is if you are running a cluster, the client can say "connect me to SALES.acme.com", the DBA can on the fly change the number of instances which are available to SALES.acme.com requests, or even move SALES.acme.com to a completely different database without the client needing to change any settings.

How to check for file existence

# file? will only return true for files
File.file?(filename)

and

# Will also return true for directories - watch out!
File.exist?(filename)

IOException: Too many open files

Don't know the nature of your app, but I have seen this error manifested multiple times because of a connection pool leak, so that would be worth checking out. On Linux, socket connections consume file descriptors as well as file system files. Just a thought.

How to update/modify an XML file in python?

The quick and easy way, which you definitely should not do (see below), is to read the whole file into a list of strings using readlines(). I write this in case the quick and easy solution is what you're looking for.

Just open the file using open(), then call the readlines() method. What you'll get is a list of all the strings in the file. Now, you can easily add strings before the last element (just add to the list one element before the last). Finally, you can write these back to the file using writelines().

An example might help:

my_file = open(filename, "r")
lines_of_file = my_file.readlines()
lines_of_file.insert(-1, "This line is added one before the last line")
my_file.writelines(lines_of_file)

The reason you shouldn't be doing this is because, unless you are doing something very quick n' dirty, you should be using an XML parser. This is a library that allows you to work with XML intelligently, using concepts like DOM, trees, and nodes. This is not only the proper way to work with XML, it is also the standard way, making your code both more portable, and easier for other programmers to understand.

Tim's answer mentioned checking out xml.dom.minidom for this purpose, which I think would be a great idea.

Generating a WSDL from an XSD file

I'd like to differ with marc_s on this, who wrote:

a XSD describes the DATA aspects e.g. of a webservice - the WSDL describes the FUNCTIONS of the web services (method calls). You cannot typically figure out the method calls from your data alone.

WSDL does not describe functions. WSDL defines a network interface, which itself is comprised of endpoints that get messages and then sometimes reply with messages. WSDL describes the endpoints, and the request and reply messages. It is very much message oriented.

We often think of WSDL as a set of functions, but this is because the web services tools typically generate client-side proxies that expose the WSDL operations as methods or function calls. But the WSDL does not require this. This is a side effect of the tools.

EDIT: Also, in the general case, XSD does not define data aspects of a web service. XSD defines the elements that may be present in a compliant XML document. Such a document may be exchanged as a message over a web service endpoint, but it need not be.


Getting back to the question I would answer the original question a little differently. I woudl say YES, it is possible to generate a WSDL file given a xsd file, in the same way it is possible to generate an omelette using eggs.

EDIT: My original response has been unclear. Let me try again. I do not suggest that XSD is equivalent to WSDL, nor that an XSD is sufficient to produce a WSDL. I do say that it is possible to generate a WSDL, given an XSD file, if by that phrase you mean "to generate a WSDL using an XSD file". Doing so, you will augment the information in the XSD file to generate the WSDL. You will need to define additional things - message parts, operations, port types - none of these are present in the XSD. But it is possible to "generate a WSDL, given an XSD", with some creative effort.

If the phrase "generate a WSDL given an XSD" is taken to imply "mechanically transform an XSD into a WSDL", then the answer is NO, you cannot do that. This much should be clear given my description of the WSDL above.

When generating a WSDL using an XSD file, you will typically do something like this (note the creative steps in this procedure):

  1. import the XML schema into the WSDL (wsdl:types element)
  2. add to the set of types or elements with additional ones, or wrappers (let's say arrays, or structures containing the basic types) as desired. The result of #1 and #2 comprise all the types the WSDL will use.
  3. define a set of in and out messages (and maybe faults) in terms of those previously defined types.
  4. Define a port-type, which is the collection of pairings of in.out messages. You might think of port-type as a WSDL analog to a Java interface.
  5. Specify a binding, which implements the port-type and defines how messages will be serialized.
  6. Specify a service, which implements the binding.

Most of the WSDL is more or less boilerplate. It can look daunting, but that is mostly because of those scary and plentiful angle brackets, I've found.

Some have suggested that this is a long-winded manual process. Maybe. But this is how you can build interoperable services. You can also use tools for defining WSDL. Dynamically generating WSDL from code will lead to interop pitfalls.

How to map an array of objects in React

I think you want to print the name of the person or both the name and email :

const renObjData = this.props.data.map(function(data, idx) {
    return <p key={idx}>{data.name}</p>;
});

or :

const renObjData = this.props.data.map(function(data, idx) {
   return ([
       <p key={idx}>{data.name}</p>,
       <p key={idx}>{data.email}</p>,
   ]);
});

Get string after character

echo "GenFiltEff=7.092200e-01" | cut -d "=" -f2 

How do I find the CPU and RAM usage using PowerShell?

I use the following PowerShell snippet to get CPU usage for local or remote systems:

Get-Counter -ComputerName localhost '\Process(*)\% Processor Time' | Select-Object -ExpandProperty countersamples | Select-Object -Property instancename, cookedvalue| Sort-Object -Property cookedvalue -Descending| Select-Object -First 20| ft InstanceName,@{L='CPU';E={($_.Cookedvalue/100).toString('P')}} -AutoSize

Same script but formatted with line continuation:

Get-Counter -ComputerName localhost '\Process(*)\% Processor Time' `
    | Select-Object -ExpandProperty countersamples `
    | Select-Object -Property instancename, cookedvalue `
    | Sort-Object -Property cookedvalue -Descending | Select-Object -First 20 `
    | ft InstanceName,@{L='CPU';E={($_.Cookedvalue/100).toString('P')}} -AutoSize

On a 4 core system it will return results that look like this:

InstanceName          CPU
------------          ---
_total                399.61 %
idle                  314.75 %
system                26.23 %
services              24.69 %
setpoint              15.43 %
dwm                   3.09 %
policy.client.invoker 3.09 %
imobilityservice      1.54 %
mcshield              1.54 %
hipsvc                1.54 %
svchost               1.54 %
stacsv64              1.54 %
wmiprvse              1.54 %
chrome                1.54 %
dbgsvc                1.54 %
sqlservr              0.00 %
wlidsvc               0.00 %
iastordatamgrsvc      0.00 %
intelmefwservice      0.00 %
lms                   0.00 %

The ComputerName argument will accept a list of servers, so with a bit of extra formatting you can generate a list of top processes on each server. Something like:

$psstats = Get-Counter -ComputerName utdev1,utdev2,utdev3 '\Process(*)\% Processor Time' -ErrorAction SilentlyContinue | Select-Object -ExpandProperty countersamples | %{New-Object PSObject -Property @{ComputerName=$_.Path.Split('\')[2];Process=$_.instancename;CPUPct=("{0,4:N0}%" -f $_.Cookedvalue);CookedValue=$_.CookedValue}} | ?{$_.CookedValue -gt 0}| Sort-Object @{E='ComputerName'; A=$true },@{E='CookedValue'; D=$true },@{E='Process'; A=$true }
$psstats | ft @{E={"{0,25}" -f $_.Process};L="ProcessName"},CPUPct -AutoSize -GroupBy ComputerName -HideTableHeaders

Which would result in a $psstats variable with the raw data and the following display:

   ComputerName: utdev1

           _total  397%
             idle  358%
             3mws   28%
           webcrs   10%


   ComputerName: utdev2

           _total  400%
             idle  248%
             cpfs   42%
             cpfs   36%
             cpfs   34%
          svchost   21%
         services   19%


   ComputerName: utdev3

           _total  200%
             idle  200%

How to loop through all the properties of a class?

This is how I do it.

foreach (var fi in typeof(CustomRoles).GetFields())
{
    var propertyName = fi.Name;
}

What exactly is nullptr?

Let's say that you have a function (f) which is overloaded to take both int and char*. Before C++ 11, If you wanted to call it with a null pointer, and you used NULL (i.e. the value 0), then you would call the one overloaded for int:

void f(int);
void f(char*);

void g() 
{
  f(0); // Calls f(int).
  f(NULL); // Equals to f(0). Calls f(int).
}

This is probably not what you wanted. C++11 solves this with nullptr; Now you can write the following:

void g()
{
  f(nullptr); //calls f(char*)
}

Regular expression to stop at first match

Here's another way.

Here's the one you want. This is lazy [\s\S]*?

The first item: [\s\S]*?(?:location="[^"]*")[\s\S]* Replace with: $1

Explaination: https://regex101.com/r/ZcqcUm/2


For completeness, this gets the last one. This is greedy [\s\S]*

The last item:[\s\S]*(?:location="([^"]*)")[\s\S]* Replace with: $1

Explaination: https://regex101.com/r/LXSPDp/3


There's only 1 difference between these two regular expressions and that is the ?

How to get a table cell value using jQuery?

a less-jquerish approach:

$('#mytable tr').each(function() {
    if (!this.rowIndex) return; // skip first row
    var customerId = this.cells[0].innerHTML;
});

this can obviously be changed to work with not-the-first cells.

Angular JS POST request not sending JSON data

If you are serializing your data object, it will not be a proper json object. Take what you have, and just wrap the data object in a JSON.stringify().

$http({
    url: '/user_to_itsr',
    method: "POST",
    data: JSON.stringify({application:app, from:d1, to:d2}),
    headers: {'Content-Type': 'application/json'}
}).success(function (data, status, headers, config) {
    $scope.users = data.users; // assign  $scope.persons here as promise is resolved here 
}).error(function (data, status, headers, config) {
    $scope.status = status + ' ' + headers;
});

How do I find an element that contains specific text in Selenium WebDriver (Python)?

Use driver.find_elements_by_xpath and matches regex matching function for the case insensitive search of the element by its text.

driver.find_elements_by_xpath("//*[matches(.,'My Button', 'i')]")

PHP7 : install ext-dom issue

For CentOS, RHEL, Fedora:

$ yum search php-xml
============================================================================================================ N/S matched: php-xml ============================================================================================================
php-xml.x86_64 : A module for PHP applications which use XML
php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php-xmlseclibs.noarch : PHP library for XML Security
php54-php-xml.x86_64 : A module for PHP applications which use XML
php54-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php55-php-xml.x86_64 : A module for PHP applications which use XML
php55-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php56-php-xml.x86_64 : A module for PHP applications which use XML
php56-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php70-php-xml.x86_64 : A module for PHP applications which use XML
php70-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php71-php-xml.x86_64 : A module for PHP applications which use XML
php71-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php72-php-xml.x86_64 : A module for PHP applications which use XML
php72-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php73-php-xml.x86_64 : A module for PHP applications which use XML
php73-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol

Then select the php-xml version matching your php version:

# php -v
PHP 7.2.11 (cli) (built: Oct 10 2018 10:00:29) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies

# sudo yum install -y php72-php-xml.x86_64

How to refresh materialized view in oracle

a bit late to the game, but I found a way to make the original syntax in this question work (I'm on Oracle 11g)

** first switch to schema of your MV **

EXECUTE DBMS_MVIEW.REFRESH(LIST=>'MV_MY_VIEW');

alternatively you can add some options:

EXECUTE DBMS_MVIEW.REFRESH(LIST=>'MV_MY_VIEW',PARALLELISM=>4);

this actually works for me, and adding parallelism option sped my execution about 2.5 times.

More info here: How to Refresh a Materialized View in Parallel

round a single column in pandas

No need to use for loop. It can be directly applied to a column of a dataframe

sleepstudy['Reaction'] = sleepstudy['Reaction'].round(1)

HTML Drag And Drop On Mobile Devices

jQuery UI Touch Punch just solves it all.

It's a Touch Event Support for jQuery UI. Basically, it just wires touch event back to jQuery UI. Tested on iPad, iPhone, Android and other touch-enabled mobile devices. I used jQuery UI sortable and it works like a charm.

http://touchpunch.furf.com/

What is the best way to iterate over a dictionary?

If say, you want to iterate over the values collection by default, I believe you can implement IEnumerable<>, Where T is the type of the values object in the dictionary, and "this" is a Dictionary.

public new IEnumerator<T> GetEnumerator()
{
   return this.Values.GetEnumerator();
}

How to save CSS changes of Styles panel of Chrome Developer Tools?

As long as you haven't been sticking the CSS in element.style:

  1. Go to a style you have added. There should be a link saying inspector-stylesheet:

enter image description here

  1. Click on that, and it will open up all the CSS that you have added in the sources panel

  2. Copy and paste it - yay!

If you have been using element.style:

You can just right-click on your HTML element, click Edit as HTML and then copy and paste the HTML with the inline styles.

How do I start an activity from within a Fragment?

You should do it with getActivity().startActivity(myIntent)

PHP: How to remove all non printable characters in a string?

you can use character classes

/[[:cntrl:]]+/

How to put img inline with text

Images have display: inline by default.
You might want to put the image inside the paragraph.
<p><img /></p>

Split string to equal length substrings in Java

public static String[] split(String src, int len) {
    String[] result = new String[(int)Math.ceil((double)src.length()/(double)len)];
    for (int i=0; i<result.length; i++)
        result[i] = src.substring(i*len, Math.min(src.length(), (i+1)*len));
    return result;
}

Attach to a processes output for viewing

I wanted to remotely watch a yum upgrade process that had been run locally, so while there were probably more efficient ways to do this, here's what I did:

watch cat /dev/vcsa1

Obviously you'd want to use vcsa2, vcsa3, etc., depending on which terminal was being used.

So long as my terminal window was of the same width as the terminal that the command was being run on, I could see a snapshot of their current output every two seconds. The other commands recommended elsewhere did not work particularly well for my situation, but that one did the trick.

POST request with a simple string in body with Alamofire

You can do this:

  1. I created a separated request Alamofire object.
  2. Convert string to Data
  3. Put in httpBody the data

    var request = URLRequest(url: URL(string: url)!)
    request.httpMethod = HTTPMethod.post.rawValue
    request.setValue("application/json", forHTTPHeaderField: "Content-Type")
    
    let pjson = attendences.toJSONString(prettyPrint: false)
    let data = (pjson?.data(using: .utf8))! as Data
    
    request.httpBody = data
    
    Alamofire.request(request).responseJSON { (response) in
    
    
        print(response)
    
    }
    

What does "pending" mean for request in Chrome Developer Window?

Same problem with Chrome : I had in my html page the following code :

<body>
  ...
  <script src="http://myserver/lib/load.js"></script>
  ...
</body>

But the load.js was always in status pending when looking in the Network pannel.

I found a workaround using asynchronous load of load.js:

<body>
  ...
  <script>
    setTimeout(function(){
      var head, script;
      head = document.getElementsByTagName("head")[0];
      script = document.createElement("script");
      script.src = "http://myserver/lib/load.js";
      head.appendChild(script);
    }, 1);
  </script>
  ...
</body>

Now its working fine.

How do you decrease navbar height in Bootstrap 3?

bootstrap had 15px top padding and 15px bottom padding on .navbar-nav > li > a so you need to decrease it by overriding it in your css file and .navbar has min-height:50px; decrease it as much you want.

for example

.navbar-nav > li > a {padding-top:5px !important; padding-bottom:5px !important;}
.navbar {min-height:32px !important}

add these classes to your css and then check.

What characters are forbidden in Windows and Linux directory names?

Here's a c# implementation for windows based on Christopher Oezbek's answer

It was made more complex by the containsFolder boolean, but hopefully covers everything

/// <summary>
/// This will replace invalid chars with underscores, there are also some reserved words that it adds underscore to
/// </summary>
/// <remarks>
/// https://stackoverflow.com/questions/1976007/what-characters-are-forbidden-in-windows-and-linux-directory-names
/// </remarks>
/// <param name="containsFolder">Pass in true if filename represents a folder\file (passing true will allow slash)</param>
public static string EscapeFilename_Windows(string filename, bool containsFolder = false)
{
    StringBuilder builder = new StringBuilder(filename.Length + 12);

    int index = 0;

    // Allow colon if it's part of the drive letter
    if (containsFolder)
    {
        Match match = Regex.Match(filename, @"^\s*[A-Z]:\\", RegexOptions.IgnoreCase);
        if (match.Success)
        {
            builder.Append(match.Value);
            index = match.Length;
        }
    }

    // Character substitutions
    for (int cntr = index; cntr < filename.Length; cntr++)
    {
        char c = filename[cntr];

        switch (c)
        {
            case '\u0000':
            case '\u0001':
            case '\u0002':
            case '\u0003':
            case '\u0004':
            case '\u0005':
            case '\u0006':
            case '\u0007':
            case '\u0008':
            case '\u0009':
            case '\u000A':
            case '\u000B':
            case '\u000C':
            case '\u000D':
            case '\u000E':
            case '\u000F':
            case '\u0010':
            case '\u0011':
            case '\u0012':
            case '\u0013':
            case '\u0014':
            case '\u0015':
            case '\u0016':
            case '\u0017':
            case '\u0018':
            case '\u0019':
            case '\u001A':
            case '\u001B':
            case '\u001C':
            case '\u001D':
            case '\u001E':
            case '\u001F':

            case '<':
            case '>':
            case ':':
            case '"':
            case '/':
            case '|':
            case '?':
            case '*':
                builder.Append('_');
                break;

            case '\\':
                builder.Append(containsFolder ? c : '_');
                break;

            default:
                builder.Append(c);
                break;
        }
    }

    string built = builder.ToString();

    if (built == "")
    {
        return "_";
    }

    if (built.EndsWith(" ") || built.EndsWith("."))
    {
        built = built.Substring(0, built.Length - 1) + "_";
    }

    // These are reserved names, in either the folder or file name, but they are fine if following a dot
    // CON, PRN, AUX, NUL, COM0 .. COM9, LPT0 .. LPT9
    builder = new StringBuilder(built.Length + 12);
    index = 0;
    foreach (Match match in Regex.Matches(built, @"(^|\\)\s*(?<bad>CON|PRN|AUX|NUL|COM\d|LPT\d)\s*(\.|\\|$)", RegexOptions.IgnoreCase))
    {
        Group group = match.Groups["bad"];
        if (group.Index > index)
        {
            builder.Append(built.Substring(index, match.Index - index + 1));
        }

        builder.Append(group.Value);
        builder.Append("_");        // putting an underscore after this keyword is enough to make it acceptable

        index = group.Index + group.Length;
    }

    if (index == 0)
    {
        return built;
    }

    if (index < built.Length - 1)
    {
        builder.Append(built.Substring(index));
    }

    return builder.ToString();
}

How to create jobs in SQL Server Express edition

The functionality of creating SQL Agent Jobs is not available in SQL Server Express Edition. An alternative is to execute a batch file that executes a SQL script using Windows Task Scheduler.

In order to do this first create a batch file named sqljob.bat

sqlcmd -S servername -U username -P password -i <path of sqljob.sql>

Replace the servername, username, password and path with yours.

Then create the SQL Script file named sqljob.sql

USE [databasename]
--T-SQL commands go here
GO

Replace the [databasename] with your database name. The USE and GO is necessary when you write the SQL script.

sqlcmd is a command-line utility to execute SQL scripts. After creating these two files execute the batch file using Windows Task Scheduler.

NB: An almost same answer was posted for this question before. But I felt it was incomplete as it didn't specify about login information using sqlcmd.

Is it possible to install iOS 6 SDK on Xcode 5?

Just for me the easiest solution:

  1. Locate an older SDK like for example "iPhoneOS6.1 sdk" in an older version of xcode for example. If you haven't, you can downlad it from Apple Developer server at this address: https://developer.apple.com/downloads/index.action?name=Xcode When you open the xcode.dmg you can find it by opening the Xcode.app (right click and "show contents") and go to Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.1 sdk enter image description here
  2. Simple Copy the folder iPhoneOS6.X sdk and paste it in your xcode.app
    • right click on your xcode.app in Applications folder.
    • Go to Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/
    • Just paste here.

enter image description here

  1. Close your xcode app and re-open it again.

To test an app in iOS 6 on your simulator: - Just choose iOS 6.0 in your active sheme. enter image description here

To build your app in iOS 6, so the design of your app will be the older design on an iPhone with iOS 7 also: - Choose iOS6.1 in Targets - Base SDK

enter image description here

Just note : When you change the base SDK in your Targets, iOS 7.0 won't be available anymore for building on the simulator !

Pretty printing JSON from Jackson 2.2's ObjectMapper

Try this.

 objectMapper.enable(SerializationConfig.Feature.INDENT_OUTPUT);

Find maximum value of a column and return the corresponding row values using Pandas

Assuming df has a unique index, this gives the row with the maximum value:

In [34]: df.loc[df['Value'].idxmax()]
Out[34]: 
Country        US
Place      Kansas
Value         894
Name: 7

Note that idxmax returns index labels. So if the DataFrame has duplicates in the index, the label may not uniquely identify the row, so df.loc may return more than one row.

Therefore, if df does not have a unique index, you must make the index unique before proceeding as above. Depending on the DataFrame, sometimes you can use stack or set_index to make the index unique. Or, you can simply reset the index (so the rows become renumbered, starting at 0):

df = df.reset_index()

get everything between <tag> and </tag> with php

You can use the following:

$regex = '#<\s*?code\b[^>]*>(.*?)</code\b[^>]*>#s';
  • \b ensures that a typo (like <codeS>) is not captured.
  • The first pattern [^>]* captures the content of a tag with attributes (eg a class).
  • Finally, the flag s capture content with newlines.

See the result here : http://lumadis.be/regex/test_regex.php?id=1081

How to add screenshot to READMEs in github repository?

First, create a directory(folder) in the root of your local repo that will contain the screenshots you want added. Let’s call the name of this directory screenshots. Place the images (JPEG, PNG, GIF,` etc) you want to add into this directory.

Android Studio Workspace Screenshot

Secondly, you need to add a link to each image into your README. So, if I have images named 1_ArtistsActivity.png and 2_AlbumsActivity.png in my screenshots directory, I will add their links like so:

 <img src="screenshots/1_ArtistsActivity.png" height="400" alt="Screenshot"/> <img src=“screenshots/2_AlbumsActivity.png" height="400" alt="Screenshot"/>

If you want each screenshot on a separate line, write their links on separate lines. However, it’s better if you write all the links in one line, separated by space only. It might actually not look too good but by doing so GitHub automatically arranges them for you.

Finally, commit your changes and push it!

Is there a method that tells my program to quit?

In Python 3 there is an exit() function:

elif choice == "q":
    exit()

What is the most efficient way to get first and last line of a text file?

First open the file in read mode.Then use readlines() method to read line by line.All the lines stored in a list.Now you can use list slices to get first and last lines of the file.

    a=open('file.txt','rb')
    lines = a.readlines()
    if lines:
        first_line = lines[:1]
        last_line = lines[-1]

how to modify an existing check constraint?

No. If such a feature existed it would be listed in this syntax illustration. (Although it's possible there is an undocumented SQL feature, or maybe there is some package that I'm not aware of.)

Append date to filename in linux

There's two problems here.

1. Get the date as a string

This is pretty easy. Just use the date command with the + option. We can use backticks to capture the value in a variable.

$ DATE=`date +%d-%m-%y` 

You can change the date format by using different % options as detailed on the date man page.

2. Split a file into name and extension.

This is a bit trickier. If we think they'll be only one . in the filename we can use cut with . as the delimiter.

$ NAME=`echo $FILE | cut -d. -f1
$ EXT=`echo $FILE | cut -d. -f2`

However, this won't work with multiple . in the file name. If we're using bash - which you probably are - we can use some bash magic that allows us to match patterns when we do variable expansion:

$ NAME=${FILE%.*}
$ EXT=${FILE#*.} 

Putting them together we get:

$ FILE=somefile.txt             
$ NAME=${FILE%.*}
$ EXT=${FILE#*.} 
$ DATE=`date +%d-%m-%y`         
$ NEWFILE=${NAME}_${DATE}.${EXT}
$ echo $NEWFILE                 
somefile_25-11-09.txt                         

And if we're less worried about readability we do all the work on one line (with a different date format):

$ FILE=somefile.txt  
$ FILE=${FILE%.*}_`date +%d%b%y`.${FILE#*.}
$ echo $FILE                                 
somefile_25Nov09.txt

How do I pass parameters to a jar file at the time of execution?

The JAVA Documentation says:

java [ options ] -jar file.jar [ argument ... ]

and

... Non-option arguments after the class name or JAR file name are passed to the main function...

Maybe you have to put the arguments in single quotes.

How to use OpenCV SimpleBlobDetector

Python: Reads image blob.jpg and performs blob detection with different parameters.

#!/usr/bin/python

# Standard imports
import cv2
import numpy as np;

# Read image
im = cv2.imread("blob.jpg")

# Setup SimpleBlobDetector parameters.
params = cv2.SimpleBlobDetector_Params()

# Change thresholds
params.minThreshold = 10
params.maxThreshold = 200


# Filter by Area.
params.filterByArea = True
params.minArea = 1500

# Filter by Circularity
params.filterByCircularity = True
params.minCircularity = 0.1

# Filter by Convexity
params.filterByConvexity = True
params.minConvexity = 0.87

# Filter by Inertia
params.filterByInertia = True
params.minInertiaRatio = 0.01

# Create a detector with the parameters
detector = cv2.SimpleBlobDetector(params)


# Detect blobs.
keypoints = detector.detect(im)

# Draw detected blobs as red circles.
# cv2.DRAW_MATCHES_FLAGS_DRAW_RICH_KEYPOINTS ensures
# the size of the circle corresponds to the size of blob

im_with_keypoints = cv2.drawKeypoints(im, keypoints, np.array([]), (0,0,255), cv2.DRAW_MATCHES_FLAGS_DRAW_RICH_KEYPOINTS)

# Show blobs
cv2.imshow("Keypoints", im_with_keypoints)
cv2.waitKey(0)

C++: Reads image blob.jpg and performs blob detection with different parameters.

#include "opencv2/opencv.hpp"

using namespace cv;
using namespace std;

int main(int argc, char** argv)
{
    // Read image
#if CV_MAJOR_VERSION < 3   // If you are using OpenCV 2
    Mat im = imread("blob.jpg", CV_LOAD_IMAGE_GRAYSCALE);
#else
    Mat im = imread("blob.jpg", IMREAD_GRAYSCALE);
#endif

    // Setup SimpleBlobDetector parameters.
    SimpleBlobDetector::Params params;

    // Change thresholds
    params.minThreshold = 10;
    params.maxThreshold = 200;

    // Filter by Area.
    params.filterByArea = true;
    params.minArea = 1500;

    // Filter by Circularity
    params.filterByCircularity = true;
    params.minCircularity = 0.1;

    // Filter by Convexity
    params.filterByConvexity = true;
    params.minConvexity = 0.87;

    // Filter by Inertia
    params.filterByInertia = true;
    params.minInertiaRatio = 0.01;

    // Storage for blobs
    std::vector<KeyPoint> keypoints;

#if CV_MAJOR_VERSION < 3   // If you are using OpenCV 2

    // Set up detector with params
    SimpleBlobDetector detector(params);

    // Detect blobs
    detector.detect(im, keypoints);
#else 

    // Set up detector with params
    Ptr<SimpleBlobDetector> detector = SimpleBlobDetector::create(params);

    // Detect blobs
    detector->detect(im, keypoints);
#endif 

    // Draw detected blobs as red circles.
    // DrawMatchesFlags::DRAW_RICH_KEYPOINTS flag ensures
    // the size of the circle corresponds to the size of blob

    Mat im_with_keypoints;
    drawKeypoints(im, keypoints, im_with_keypoints, Scalar(0, 0, 255), DrawMatchesFlags::DRAW_RICH_KEYPOINTS);

    // Show blobs
    imshow("keypoints", im_with_keypoints);
    waitKey(0);
}

The answer has been copied from this tutorial I wrote at LearnOpenCV.com explaining various parameters of SimpleBlobDetector. You can find additional details about the parameters in the tutorial.

Error when trying to access XAMPP from a network

In your xampppath\apache\conf\extra open file httpd-xampp.conf and find the below tag:

# Close XAMPP sites here
<LocationMatch "^/(?i:(?:xampp|licenses|phpmyadmin|webalizer|server-status|server-info))">
    Order deny,allow
    Deny from all
    Allow from ::1 127.0.0.0/8 
    ErrorDocument 403 /error/HTTP_XAMPP_FORBIDDEN.html.var
</LocationMatch>

and add

"Allow from all"

after Allow from ::1 127.0.0.0/8 {line}

Restart xampp, and you are done.

In later versions of Xampp

...you can simply remove this part

#
# New XAMPP security concept
#
<LocationMatch "^/(?i:(?:xampp|security|licenses|phpmyadmin|webalizer|server-status|server-info))">
        Require local
    ErrorDocument 403 /error/XAMPP_FORBIDDEN.html.var
</LocationMatch>

from the same file and it should work over the local network.

How to check if mod_rewrite is enabled in php?

One more method through exec().

exec('/usr/bin/httpd -M | find "rewrite_module"',$output);

If mod_rewrite is loaded it will return "rewrite_module" in output.

What's the difference between disabled="disabled" and readonly="readonly" for HTML form input fields?

If the value of a disabled textbox needs to be retained when a form is cleared (reset), disabled = "disabled" has to be used, as read-only textbox will not retain the value

For Example:

HTML

Textbox

<input type="text" id="disabledText" name="randombox" value="demo" disabled="disabled" />

Reset button

<button type="reset" id="clearButton">Clear</button>

In the above example, when Clear button is pressed, disabled text value will be retained in the form. Value will not be retained in the case of input type = "text" readonly="readonly"

How to log SQL statements in Spring Boot?

Settings to avoid

You should not use this setting:

spring.jpa.show-sql=true 

The problem with show-sql is that the SQL statements are printed in the console, so there is no way to filter them, as you'd normally do with a Logging framework.

Using Hibernate logging

In your log configuration file, if you add the following logger:

<logger name="org.hibernate.SQL" level="debug"/>

Then, Hibernate will print the SQL statements when the JDBC PreparedStatement is created. That's why the statement will be logged using parameter placeholders:

INSERT INTO post (title, version, id) VALUES (?, ?, ?)

If you want to log the bind parameter values, just add the following logger as well:

<logger name="org.hibernate.type.descriptor.sql.BasicBinder" level="trace"/>

Once you set the BasicBinder logger, you will see that the bind parameter values are logged as well:

DEBUG [main]: o.h.SQL - insert into post (title, version, id) values (?, ?, ?)
TRACE [main]: o.h.t.d.s.BasicBinder - binding parameter [1] as [VARCHAR] - [High-Performance Java Persistence, part 1]
TRACE [main]: o.h.t.d.s.BasicBinder - binding parameter [2] as [INTEGER] - [0]
TRACE [main]: o.h.t.d.s.BasicBinder - binding parameter [3] as [BIGINT] - [1]

Using datasource-proxy

The datasource-proxy OSS framework allows you to proxy the actual JDBC DataSource, as illustrated by the following diagram:

DataSource-Proxy

You can define the dataSource bean that will be used by Hibernate as follows:

@Bean
public DataSource dataSource(DataSource actualDataSource) {
    SLF4JQueryLoggingListener loggingListener = new SLF4JQueryLoggingListener();
    loggingListener.setQueryLogEntryCreator(new InlineQueryLogEntryCreator());
    return ProxyDataSourceBuilder
        .create(actualDataSource)
        .name(DATA_SOURCE_PROXY_NAME)
        .listener(loggingListener)
        .build();
}

Notice that the actualDataSource must be the DataSource defined by the [connection pool][2] you are using in your application.

Next, you need to set the net.ttddyy.dsproxy.listener log level to debug in your logging framework configuration file. For instance, if you're using Logback, you can add the following logger:

<logger name="net.ttddyy.dsproxy.listener" level="debug"/>

Once you enable datasource-proxy, the SQl statement are going to be logged as follows:

Name:DATA_SOURCE_PROXY, Time:6, Success:True,
Type:Prepared, Batch:True, QuerySize:1, BatchSize:3,
Query:["insert into post (title, version, id) values (?, ?, ?)"],
Params:[(Post no. 0, 0, 0), (Post no. 1, 0, 1), (Post no. 2, 0, 2)]

How to iterate over the files of a certain directory, in Java?

Use java.io.File.listFiles
Or
If you want to filter the list prior to iteration (or any more complicated use case), use apache-commons FileUtils. FileUtils.listFiles

Ansible: Set variable to file content

You can use fetch module to copy files from remote hosts to local, and lookup module to read the content of fetched files.

SQL Server Convert Varchar to Datetime

Like this

DECLARE @date DATETIME
SET @date = '2011-09-28 18:01:00'
select convert(varchar, @date,105) + ' ' + convert(varchar, @date,108)

Get the IP Address of local computer

In DEV C++, I used pure C with WIN32, with this given piece of code:

case IDC_IP:

             gethostname(szHostName, 255);
             host_entry=gethostbyname(szHostName);
             szLocalIP = inet_ntoa (*(struct in_addr *)*host_entry->h_addr_list);
             //WSACleanup(); 
             writeInTextBox("\n");
             writeInTextBox("IP: "); 
             writeInTextBox(szLocalIP);
             break;

When I click the button 'show ip', it works. But on the second time, the program quits (without warning or error). When I do:

//WSACleanup(); 

The program does not quit, even clicking the same button multiple times with fastest speed. So WSACleanup() may not work well with Dev-C++..

Animated GIF in IE stopping

I had this same problem, common also to other borwsers like Firefox. Finally I discovered that dynamically create an element with animated gif inside at form submit did not animate, so I developed the following workaorund.

1) At document.ready(), each FORM found in page, receive position:relative property and then to each one is attached an invisible DIV.bg-overlay.

2) After this, assuming that each submit value of my website is identified by btn-primary css class, again at document.ready(), I look for these buttons, traverse to the FORM parent of each one, and at form submit, I fire showOverlayOnFormExecution(this,true); function, passing clicked button and a boolean that toggle visibility of DIV.bg-overlay.

$(document).ready(function() {

  //Append LOADING image to all forms
  $('form').css('position','relative').append('<div class="bg-overlay" style="display:none;"><img src="/images/loading.gif"></div>');

  //At form submit, fires a specific function
  $('form .btn-primary').closest('form').submit(function (e) {
    showOverlayOnFormExecution(this,true);
  });
});

CSS for DIV.bg-overlay is the following:

.bg-overlay
{
  width:100%;
  height:100%;
  position:absolute;
  top:0;
  left:0;
  background:rgba(255,255,255,0.6);
  z-index:100;
}

.bg-overlay img
{
  position:absolute;
  left:50%;
  top:50%;
  margin-left:-40px; //my loading images is 80x80 px. This is done to center it horizontally and vertically.
  margin-top:-40px;
  max-width:auto;
  max-height:80px;
}

3) At any form submit, the following function is fired to show a semi-white background overlay all over it (that deny ability to interact again with form) and an animated gif inside it (that visually show a loading action).

function showOverlayOnFormExecution(clicked_button, showOrNot) 
{
    if(showOrNot == 1)
    {
        //Add "content" of #bg-overlay_container (copying it) to the confrm that contains clicked button 
        $(clicked_button).closest('form').find('.bg-overlay').show();
    }
    else
        $('form .bg-overlay').hide();
}

Showing animated gif at form submit, instead of appending it at this event, solves "gif animation freeze" problem of various browsers (as said, I found this problem in IE and Firefox, not in Chrome)

Where does Vagrant download its .box files to?

In addition to

Mac:
~/.vagrant.d/

Windows:
C:\Users\%userprofile%\.vagrant.d\boxes

You have to delete the files in VirtualBox/OtherVMprovider to make a clean start.

mysql after insert trigger which updates another table's column

Try this:

DELIMITER $$
CREATE TRIGGER occupy_trig
AFTER INSERT ON `OccupiedRoom` FOR EACH ROW
begin
       DECLARE id_exists Boolean;
       -- Check BookingRequest table
       SELECT 1
       INTO @id_exists
       FROM BookingRequest
       WHERE BookingRequest.idRequest= NEW.idRequest;

       IF @id_exists = 1
       THEN
           UPDATE BookingRequest
           SET status = '1'
           WHERE idRequest = NEW.idRequest;
        END IF;
END;
$$
DELIMITER ;

How to zip a whole folder using PHP

Use this function:

function zip($source, $destination)
{
    if (!extension_loaded('zip') || !file_exists($source)) {
        return false;
    }

    $zip = new ZipArchive();
    if (!$zip->open($destination, ZIPARCHIVE::CREATE)) {
        return false;
    }

    $source = str_replace('\\', '/', realpath($source));

    if (is_dir($source) === true) {
        $files = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($source), RecursiveIteratorIterator::SELF_FIRST);

        foreach ($files as $file) {
            $file = str_replace('\\', '/', $file);

            // Ignore "." and ".." folders
            if (in_array(substr($file, strrpos($file, '/')+1), array('.', '..'))) {
                continue;
            }               

            $file = realpath($file);

            if (is_dir($file) === true) {
                $zip->addEmptyDir(str_replace($source . '/', '', $file . '/'));
            } elseif (is_file($file) === true) {
                $zip->addFromString(str_replace($source . '/', '', $file), file_get_contents($file));
            }
        }
    } elseif (is_file($source) === true) {
        $zip->addFromString(basename($source), file_get_contents($source));
    }

    return $zip->close();
}

Example use:

zip('/folder/to/compress/', './compressed.zip');

How do I do a case-insensitive string comparison?

Comparing strings in a case insensitive way seems trivial, but it's not. I will be using Python 3, since Python 2 is underdeveloped here.

The first thing to note is that case-removing conversions in Unicode aren't trivial. There is text for which text.lower() != text.upper().lower(), such as "ß":

"ß".lower()
#>>> 'ß'

"ß".upper().lower()
#>>> 'ss'

But let's say you wanted to caselessly compare "BUSSE" and "Buße". Heck, you probably also want to compare "BUSSE" and "BU?E" equal - that's the newer capital form. The recommended way is to use casefold:

str.casefold()

Return a casefolded copy of the string. Casefolded strings may be used for caseless matching.

Casefolding is similar to lowercasing but more aggressive because it is intended to remove all case distinctions in a string. [...]

Do not just use lower. If casefold is not available, doing .upper().lower() helps (but only somewhat).

Then you should consider accents. If your font renderer is good, you probably think "ê" == "e^" - but it doesn't:

"ê" == "e^"
#>>> False

This is because the accent on the latter is a combining character.

import unicodedata

[unicodedata.name(char) for char in "ê"]
#>>> ['LATIN SMALL LETTER E WITH CIRCUMFLEX']

[unicodedata.name(char) for char in "e^"]
#>>> ['LATIN SMALL LETTER E', 'COMBINING CIRCUMFLEX ACCENT']

The simplest way to deal with this is unicodedata.normalize. You probably want to use NFKD normalization, but feel free to check the documentation. Then one does

unicodedata.normalize("NFKD", "ê") == unicodedata.normalize("NFKD", "e^")
#>>> True

To finish up, here this is expressed in functions:

import unicodedata

def normalize_caseless(text):
    return unicodedata.normalize("NFKD", text.casefold())

def caseless_equal(left, right):
    return normalize_caseless(left) == normalize_caseless(right)

test if display = none

Try this instead to only select the visible elements under the tbody:

$('tbody :visible').highlight(myArray[i]);

Setting POST variable without using form

Yes, simply set it to another value:

$_POST['text'] = 'another value';

This will override the previous value corresponding to text key of the array. The $_POST is superglobal associative array and you can change the values like a normal PHP array.

Caution: This change is only visible within the same PHP execution scope. Once the execution is complete and the page has loaded, the $_POST array is cleared. A new form submission will generate a new $_POST array.

If you want to persist the value across form submissions, you will need to put it in the form as an input tag's value attribute or retrieve it from a data store.

How to install libusb in Ubuntu

"I need to install it to the folder of my C program." Why?

Include usb.h:

#include <usb.h>

and remember to add -lusb to gcc:

gcc -o example example.c -lusb

This work fine for me.

c# dictionary How to add multiple values for single key?

Though nearly the same as most of the other responses, I think this is the most efficient and concise way to implement it. Using TryGetValue is faster than using ContainsKey and reindexing into the dictionary as some other solutions have shown.

void Add(string key, string val)
{
    List<string> list;

    if (!dictionary.TryGetValue(someKey, out list))
    {
       values = new List<string>();
       dictionary.Add(key, list);
    }

    list.Add(val);
}

How to use paths in tsconfig.json?

/ starts from the root only, to get the relative path we should use ./ or ../

JOIN queries vs multiple queries

This question is old, but is missing some benchmarks. I benchmarked JOIN against its 2 competitors:

  • N+1 queries
  • 2 queries, the second one using a WHERE IN(...) or equivalent

The result is clear: on MySQL, JOIN is much faster. N+1 queries can drop the performance of an application drastically:

JOIN vs WHERE IN vs N+1

That is, unless you select a lot of records that point to a very small number of distinct, foreign records. Here is a benchmark for the extreme case:

JOIN vs N+1 - all records pointing to the same foreign record

This is very unlikely to happen in a typical application, unless you're joining a -to-many relationship, in which case the foreign key is on the other table, and you're duplicating the main table data many times.

Takeaway:

  • For *-to-one relationships, always use JOIN
  • For *-to-many relationships, a second query might be faster

See my article on Medium for more information.

Convert string to datetime in vb.net

You can try with ParseExact method

Sample

Dim format As String  
format = "d" 
Dim provider As CultureInfo = CultureInfo.InvariantCulture
result = Date.ParseExact(DateString, format, provider)

Excel: Search for a list of strings within a particular string using array formulas?

This will return the matching word or an error if no match is found. For this example I used the following.

List of words to search for: G1:G7
Cell to search in: A1

=INDEX(G1:G7,MAX(IF(ISERROR(FIND(G1:G7,A1)),-1,1)*(ROW(G1:G7)-ROW(G1)+1)))

Enter as an array formula by pressing Ctrl+Shift+Enter.

This formula works by first looking through the list of words to find matches, then recording the position of the word in the list as a positive value if it is found or as a negative value if it is not found. The largest value from this array is the position of the found word in the list. If no word is found, a negative value is passed into the INDEX() function, throwing an error.

To return the row number of a matching word, you can use the following:

=MAX(IF(ISERROR(FIND(G1:G7,A1)),-1,1)*ROW(G1:G7))

This also must be entered as an array formula by pressing Ctrl+Shift+Enter. It will return -1 if no match is found.

C++ Returning reference to local variable

A good thing to remember are these simple rules, and they apply to both parameters and return types...

  • Value - makes a copy of the item in question.
  • Pointer - refers to the address of the item in question.
  • Reference - is literally the item in question.

There is a time and place for each, so make sure you get to know them. Local variables, as you've shown here, are just that, limited to the time they are locally alive in the function scope. In your example having a return type of int* and returning &i would have been equally incorrect. You would be better off in that case doing this...

void func1(int& oValue)
{
    oValue = 1;
}

Doing so would directly change the value of your passed in parameter. Whereas this code...

void func1(int oValue)
{
    oValue = 1;
}

would not. It would just change the value of oValue local to the function call. The reason for this is because you'd actually be changing just a "local" copy of oValue, and not oValue itself.

MySQL "Or" Condition

Use brackets:

mysql_query("SELECT * FROM Drinks WHERE email='$Email' AND 
    (date='$Date_Today' 
     OR date='$Date_Yesterday' 
     OR date='$Date_TwoDaysAgo' 
     OR date='$Date_ThreeDaysAgo' 
     OR date='$Date_FourDaysAgo' 
     OR date='$Date_FiveDaysAgo' 
     OR date='$Date_SixDaysAgo' 
     OR date='$Date_SevenDaysAgo'
    )
");

But you should alsos have a look at the IN operator. So you can say ´date IN ('$date1','$date2',...)`

But if you have always a set of consecutive days why don't you do the following for the date part

date <= $Date_Today AND date >= $Date_SevenDaysAgo

How to know Hive and Hadoop versions from command prompt?

Use the version flag from the CLI

[hadoop@usernode~]$ hadoop version
Hadoop 2.7.3-amzn-1
Subversion [email protected]:/pkg/Aws157BigTop -r d94115f47e58e29d8113a887a1f5c9960c61ab83
Compiled by ec2-user on 2017-01-31T19:18Z
Compiled with protoc 2.5.0
From source with checksum 1833aada17b94cfb94ad40ccd02d3df8
This command was run using /usr/lib/hadoop/hadoop-common-2.7.3-amzn-1.jar


[hadoop@usernode ~]$ hive --version
Hive 1.0.0-amzn-8
Subversion git://ip-20-69-181-31/workspace/workspace/bigtop.release-rpm-4.8.4/build/hive/rpm/BUILD/apache-hive-1.0.0-amzn-8-src -r d94115f47e58e29d8113a887a1f5c9960c61ab83
Compiled by ec2-user on Tue Jan 31 19:51:34 UTC 2017
From source with checksum 298304aab1c4240a868146213f9ce15f

use a javascript array to fill up a drop down select box

This is a part from a REST-Service I´ve written recently.

var select = $("#productSelect")
for (var prop in data) {
    var option = document.createElement('option');
    option.innerHTML = data[prop].ProduktName
    option.value = data[prop].ProduktName;
    select.append(option)
}

The reason why im posting this is because appendChild() wasn´t working in my case so I decided to put up another possibility that works aswell.

org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 15

This was a Tomcat bug that resurfaced again with the Java 9 bytecode. The exact versions which fix this (for both Java 8/9 bytecode) are:

  • trunk for 9.0.0.M18 onwards
  • 8.5.x for 8.5.12 onwards
  • 8.0.x for 8.0.42 onwards
  • 7.0.x for 7.0.76 onwards

How do I run a command on an already existing Docker container?

So I think the answer is simpler than many misleading answers above.

To start an existing container which is stopped

docker start <container-name/ID>

To stop a running container

docker stop <container-name/ID>

Then to login to the interactive shell of a container

docker exec -it <container-name/ID> bash

To start an existing container and attach to it in one command

docker start -ai <container-name/ID>

Beware, this will stop the container on exit. But in general, you need to start the container, attach and stop it after you are done.

How do I turn a C# object into a JSON string in .NET?

I would vote for ServiceStack's JSON Serializer:

using ServiceStack;

string jsonString = new { FirstName = "James" }.ToJson();

It is also the fastest JSON serializer available for .NET: http://www.servicestack.net/benchmarks/

what is the difference between const_iterator and iterator?

if you have a list a and then following statements

list<int>::iterator it; // declare an iterator
    list<int>::const_iterator cit; // declare an const iterator 
    it=a.begin();
    cit=a.begin();

you can change the contents of the element in the list using “it” but not “cit”, that is you can use “cit” for reading the contents not for updating the elements.

*it=*it+1;//returns no error
    *cit=*cit+1;//this will return error

How to frame two for loops in list comprehension python

This should do it:

[entry for tag in tags for entry in entries if tag in entry]

Load image from resources

Try this for WPF

StreamResourceInfo sri = Application.GetResourceStream(new Uri("pack://application:,,,/WpfGifImage001;Component/Images/Progess_Green.gif"));
picBox1.Image = System.Drawing.Image.FromStream(sri.Stream);

Concatenate strings from several rows using Pandas groupby

The answer by EdChum provides you with a lot of flexibility but if you just want to concateate strings into a column of list objects you can also:

output_series = df.groupby(['name','month'])['text'].apply(list)

Reading an Excel file in python using pandas

You just need to feed the path to your file to pd.read_excel

import pandas as pd

file_path = "./my_excel.xlsx"
data_frame = pd.read_excel(file_path)

Checkout the documentation to explore parameters like skiprows to ignore rows when loading the excel

Get TimeZone offset value from TimeZone without TimeZone name

We can easily get the millisecond offset of a TimeZone with only a TimeZone instance and System.currentTimeMillis(). Then we can convert from milliseconds to any time unit of choice using the TimeUnit class.

Like so:

public static int getOffsetHours(TimeZone timeZone) {
    return (int) TimeUnit.MILLISECONDS.toHours(timeZone.getOffset(System.currentTimeMillis()));
}

Or if you prefer the new Java 8 time API

public static ZoneOffset getOffset(TimeZone timeZone) { //for using ZoneOffsett class
    ZoneId zi = timeZone.toZoneId();
    ZoneRules zr = zi.getRules();
    return zr.getOffset(LocalDateTime.now());
}

public static int getOffsetHours(TimeZone timeZone) { //just hour offset
    ZoneOffset zo = getOffset(timeZone);
    TimeUnit.SECONDS.toHours(zo.getTotalSeconds());
}

Converting a Uniform Distribution to a Normal Distribution

function distRandom(){
  do{
    x=random(DISTRIBUTION_DOMAIN);
  }while(random(DISTRIBUTION_RANGE)>=distributionFunction(x));
  return x;
}

How can I compare two dates in PHP?

$today = date('Y-m-d');//Y-m-d H:i:s
$expireDate = new DateTime($row->expireDate);// From db 
$date1=date_create($today);
$date2=date_create($expireDate->format('Y-m-d'));
$diff=date_diff($date1,$date2);

//echo $timeDiff;
if($diff->days >= 30){
    echo "Expired.";
}else{
    echo "Not expired.";
}

No == operator found while comparing structs in C++

In C++, structs do not have a comparison operator generated by default. You need to write your own:

bool operator==(const MyStruct1& lhs, const MyStruct1& rhs)
{
    return /* your comparison code goes here */
}

How to enable C++11 in Qt Creator?

According to this site add

CONFIG += c++11

to your .pro file (see at the bottom of that web page). It requires Qt 5.


The other answers, suggesting

QMAKE_CXXFLAGS += -std=c++11 (or QMAKE_CXXFLAGS += -std=c++0x)

also work with Qt 4.8 and gcc / clang.

How do I enable MSDTC on SQL Server?

I've found that the best way to debug is to use the microsoft tool called DTCPing

  1. Copy the file to both the server (DB) and the client (Application server/client pc)
    • Start it at the server and the client
    • At the server: fill in the client netbios computer name and try to setup a DTC connection
    • Restart both applications.
    • At the client: fill in the server netbios computer name and try to setup a DTC connection

I've had my fare deal of problems in our old company network, and I've got a few tips:

  • if you get the error message "Gethostbyname failed" it means the computer can not find the other computer by its netbios name. The server could for instance resolve and ping the client, but that works on a DNS level. Not on a netbios lookup level. Using WINS servers or changing the LMHOST (dirty) will solve this problem.
  • if you get an error "Acces Denied", the security settings don't match. You should compare the security tab for the msdtc and get the server and client to match. One other thing to look at is the RestrictRemoteClients value. Depending on your OS version and more importantly the Service Pack, this value can be different.
  • Other connection problems:
    • The firewall between the server and the client must allow communication over port 135. And more importantly the connection can be initiated from both sites (I had a lot of problems with the firewall people in my company because they assumed only the server would open an connection on to that port)
    • The protocol returns a random port to connect to for the real transaction communication. Firewall people don't like that, they like to restrict the ports to a certain range. You can restrict the RPC dynamic port generation to a certain range using the keys as described in How to configure RPC dynamic port allocation to work with firewalls.

In my experience, if the DTCPing is able to setup a DTC connection initiated from the client and initiated from the server, your transactions are not the problem any more.

How can I make text appear on next line instead of overflowing?

Well, you can stick one or more "soft hyphens" (&#173;) in your long unbroken strings. I doubt that old IE versions deal with that correctly, but what it's supposed to do is tell the browser about allowable word breaks that it can use if it has to.

Now, how exactly would you pick where to stuff those characters? That depends on the actual string and what it means, I guess.

MySQL root password change

On MySQL 8 you need to specify the password hashing method:

ALTER USER 'root'@'localhost' IDENTIFIED WITH caching_sha2_password BY 'new-password';

Simple (non-secure) hash function for JavaScript?

Check out this MD5 implementation for JavaScript. Its BSD Licensed and really easy to use. Example:

md5 = hex_md5("message to digest")

C++ templates that accept only certain types

That's not possible in plain C++, but you can verify template parameters at compile-time through Concept Checking, e.g. using Boost's BCCL.

As of C++20, concepts are becoming an official feature of the language.

How can I change Mac OS's default Java VM returned from /usr/libexec/java_home

It's actually pretty easy. Let's say we have this in our JavaVirtualMachines folder:

  • jdk1.7.0_51.jdk
  • jdk1.8.0.jdk

Imagine that 1.8 is our default, then we just add a new folder (for example 'old') and move the default jdk folder to that new folder. Do java -version again et voila, 1.7!

How to draw a rounded Rectangle on HTML Canvas?

I needed to do the same thing and created a method to do it.

_x000D_
_x000D_
// Now you can just call
var ctx = document.getElementById("rounded-rect").getContext("2d");
// Draw using default border radius, 
// stroke it but no fill (function's default values)
roundRect(ctx, 5, 5, 50, 50);
// To change the color on the rectangle, just manipulate the context
ctx.strokeStyle = "rgb(255, 0, 0)";
ctx.fillStyle = "rgba(255, 255, 0, .5)";
roundRect(ctx, 100, 5, 100, 100, 20, true);
// Manipulate it again
ctx.strokeStyle = "#0f0";
ctx.fillStyle = "#ddd";
// Different radii for each corner, others default to 0
roundRect(ctx, 300, 5, 200, 100, {
  tl: 50,
  br: 25
}, true);

/**
 * Draws a rounded rectangle using the current state of the canvas.
 * If you omit the last three params, it will draw a rectangle
 * outline with a 5 pixel border radius
 * @param {CanvasRenderingContext2D} ctx
 * @param {Number} x The top left x coordinate
 * @param {Number} y The top left y coordinate
 * @param {Number} width The width of the rectangle
 * @param {Number} height The height of the rectangle
 * @param {Number} [radius = 5] The corner radius; It can also be an object 
 *                 to specify different radii for corners
 * @param {Number} [radius.tl = 0] Top left
 * @param {Number} [radius.tr = 0] Top right
 * @param {Number} [radius.br = 0] Bottom right
 * @param {Number} [radius.bl = 0] Bottom left
 * @param {Boolean} [fill = false] Whether to fill the rectangle.
 * @param {Boolean} [stroke = true] Whether to stroke the rectangle.
 */
function roundRect(ctx, x, y, width, height, radius, fill, stroke) {
  if (typeof stroke === 'undefined') {
    stroke = true;
  }
  if (typeof radius === 'undefined') {
    radius = 5;
  }
  if (typeof radius === 'number') {
    radius = {tl: radius, tr: radius, br: radius, bl: radius};
  } else {
    var defaultRadius = {tl: 0, tr: 0, br: 0, bl: 0};
    for (var side in defaultRadius) {
      radius[side] = radius[side] || defaultRadius[side];
    }
  }
  ctx.beginPath();
  ctx.moveTo(x + radius.tl, y);
  ctx.lineTo(x + width - radius.tr, y);
  ctx.quadraticCurveTo(x + width, y, x + width, y + radius.tr);
  ctx.lineTo(x + width, y + height - radius.br);
  ctx.quadraticCurveTo(x + width, y + height, x + width - radius.br, y + height);
  ctx.lineTo(x + radius.bl, y + height);
  ctx.quadraticCurveTo(x, y + height, x, y + height - radius.bl);
  ctx.lineTo(x, y + radius.tl);
  ctx.quadraticCurveTo(x, y, x + radius.tl, y);
  ctx.closePath();
  if (fill) {
    ctx.fill();
  }
  if (stroke) {
    ctx.stroke();
  }

}
_x000D_
<canvas id="rounded-rect" width="500" height="200">
  <!-- Insert fallback content here -->
</canvas>
_x000D_
_x000D_
_x000D_

How to initailize byte array of 100 bytes in java with all 0's

The default element value of any array of primitives is already zero: false for booleans.

Open mvc view in new window from controller

You can use Tommy's method in forms as well:

@using (Html.BeginForm("Action", "Controller", FormMethod.Get, new { target = "_blank" }))
{
//code
}

How to prevent scanf causing a buffer overflow in C?

Directly using scanf(3) and its variants poses a number of problems. Typically, users and non-interactive use cases are defined in terms of lines of input. It's rare to see a case where, if enough objects are not found, more lines will solve the problem, yet that's the default mode for scanf. (If a user didn't know to enter a number on the first line, a second and third line will probably not help.)

At least if you fgets(3) you know how many input lines your program will need, and you won't have any buffer overflows...

C# Dictionary get item by index

If you need to extract an element key based on index, this function can be used:

public string getCard(int random)
{
    return Karta._dict.ElementAt(random).Key;
}

If you need to extract the Key where the element value is equal to the integer generated randomly, you can used the following function:

public string getCard(int random)
{
    return Karta._dict.FirstOrDefault(x => x.Value == random).Key;
}

Side Note: The first element of the dictionary is The Key and the second is the Value

Writing a new line to file in PHP (line feed)

Use PHP_EOL which outputs \r\n or \n depending on the OS.

How to format date and time in Android?

Date format class work with cheat code to make date. Like

  1. M -> 7, MM -> 07, MMM -> Jul , MMMM -> July
  2. EEE -> Tue , EEEE -> Tuesday
  3. z -> EST , zzz -> EST , zzzz -> Eastern Standard Time

You can check more cheats here.

Bash Script : what does #!/bin/bash mean?

In bash script, what does #!/bin/bash at the 1st line mean ?

In Linux system, we have shell which interprets our UNIX commands. Now there are a number of shell in Unix system. Among them, there is a shell called bash which is very very common Linux and it has a long history. This is a by default shell in Linux.

When you write a script (collection of unix commands and so on) you have a option to specify which shell it can be used. Generally you can specify which shell it wold be by using Shebang(Yes that's what it's name).

So if you #!/bin/bash in the top of your scripts then you are telling your system to use bash as a default shell.

Now coming to your second question :Is there a difference between #!/bin/bash and #!/bin/sh ?

The answer is Yes. When you tell #!/bin/bash then you are telling your environment/ os to use bash as a command interpreter. This is hard coded thing.

Every system has its own shell which the system will use to execute its own system scripts. This system shell can be vary from OS to OS(most of the time it will be bash. Ubuntu recently using dash as default system shell). When you specify #!/bin/sh then system will use it's internal system shell to interpreting your shell scripts.

Visit this link for further information where I have explained this topic.

Hope this will eliminate your confusions...good luck.

Cannot find or open the PDB file in Visual Studio C++ 2010

This can also happen if you don't have Modify permissions on the symbol cache directory configured in Tools, Options, Debugging, Symbols.

Converting a UNIX Timestamp to Formatted Date String

Try gmdate like this:

<?php
$timestamp=1333699439;
echo gmdate("Y-m-d\TH:i:s\Z", $timestamp);
?>

How to automatically convert strongly typed enum into int?

The C++ committee took one step forward (scoping enums out of global namespace) and fifty steps back (no enum type decay to integer). Sadly, enum class is simply not usable if you need the value of the enum in any non-symbolic way.

The best solution is to not use it at all, and instead scope the enum yourself using a namespace or a struct. For this purpose, they are interchangable. You will need to type a little extra when refering to the enum type itself, but that will likely not be often.

struct TextureUploadFormat {
    enum Type : uint32 {
        r,
        rg,
        rgb,
        rgba,
        __count
    };
};

// must use ::Type, which is the extra typing with this method; beats all the static_cast<>()
uint32 getFormatStride(TextureUploadFormat::Type format){
    const uint32 formatStride[TextureUploadFormat::__count] = {
        1,
        2,
        3,
        4
    };
    return formatStride[format]; // decays without complaint
}

showDialog deprecated. What's the alternative?

To display dialog box, you can use the following code. This is to display a simple AlertDialog box with multiple check boxes:

AlertDialog.Builder alertDialog= new AlertDialog.Builder(MainActivity.this); .
            alertDialog.setTitle("this is a dialog box ");
            alertDialog.setPositiveButton("ok", new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {
                    // TODO Auto-generated method stub
                    Toast.makeText(getBaseContext(),"ok ive wrote this 'ok' here" ,Toast.LENGTH_SHORT).show();

                }
            });
            alertDialog.setNegativeButton("cancel", new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {
                    // TODO Auto-generated method stub
                        Toast.makeText(getBaseContext(), "cancel ' comment same as ok'", Toast.LENGTH_SHORT).show();


                }
            });
            alertDialog.setMultiChoiceItems(items, checkedItems, new DialogInterface.OnMultiChoiceClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which, boolean isChecked) {
                    // TODO Auto-generated method stub
                    Toast.makeText(getBaseContext(), items[which] +(isChecked?"clicked'again i've wrrten this click'":"unchecked"),Toast.LENGTH_SHORT).show();

                }
            });
            alertDialog.show();

Heading

Whereas if you are using the showDialog function to display different dialog box or anything as per the arguments passed, you can create a self function and can call it under the onClickListener() function. Something like:

 public CharSequence[] items={"google","Apple","Kaye"};
public boolean[] checkedItems=new boolean[items.length];
Button bt;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    bt=(Button) findViewById(R.id.bt);
    bt.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            display(0);             
        }       
    });
}

and add the code of dialog box given above in the function definition.

What is the correct value for the disabled attribute?

From MDN by setAttribute():

To set the value of a Boolean attribute, such as disabled, you can specify any value. An empty string or the name of the attribute are recommended values. All that matters is that if the attribute is present at all, regardless of its actual value, its value is considered to be true. The absence of the attribute means its value is false. By setting the value of the disabled attribute to the empty string (""), we are setting disabled to true, which results in the button being disabled.

Link to MDN

Solution

  • I mean that in XHTML Strict is right disabled="disabled",
  • and in HTML5 is only disabled, like <input name="myinput" disabled>
  • In javascript, I set the value to true via e.disabled = true;
    or to "" via setAttribute( "disabled", "" );

Test in Chrome

var f = document.querySelectorAll( "label.disabled input" );
for( var i = 0; i < f.length; i++ )
{
    // Reference
    var e = f[ i ];

    // Actions
    e.setAttribute( "disabled", false|null|undefined|""|0|"disabled" );
    /*
        <input disabled="false"|"null"|"undefined"|empty|"0"|"disabled">
        e.getAttribute( "disabled" ) === "false"|"null"|"undefined"|""|"0"|"disabled"
        e.disabled === true
    */
    
    e.removeAttribute( "disabled" );
    /*
        <input>
        e.getAttribute( "disabled" ) === null
        e.disabled === false
    */

    e.disabled = false|null|undefined|""|0;
    /*
        <input>
        e.getAttribute( "disabled" ) === null|null|null|null|null
        e.disabled === false
    */

    e.disabled = true|" "|"disabled"|1;
    /*
        <input disabled>
        e.getAttribute( "disabled" ) === ""|""|""|""
        e.disabled === true
    */
}

Enabling WiFi on Android Emulator

Apparently it does not and I didn't quite expect it would. HOWEVER Ivan brings up a good possibility that has escaped Android people.

What is the purpose of an emulator? to EMULATE, right? I don't see why for testing purposes -provided the tester understands the limitations- the emulator might not add a Wifi emulator.

It could for example emulate WiFi access by using the underlying internet connection of the host. Obviously testing WPA/WEP differencess would not make sense but at least it could toggle access via WiFi.

Or some sort of emulator plugin where there would be a base WiFi emulator that would emulate WiFi access via the underlying connection but then via configuration it could emulate WPA/WEP by providing a list of fake WiFi networks and their corresponding fake passwords that would be matched against a configurable list of credentials.

After all the idea is to do initial testing on the emulator and then move on to the actual device.

How to delete a localStorage item when the browser window/tab is closed?

You can make use of the beforeunload event in JavaScript.

Using vanilla JavaScript you could do something like:

window.onbeforeunload = function() {
  localStorage.removeItem(key);
  return '';
};

That will delete the key before the browser window/tab is closed and prompts you to confirm the close window/tab action. I hope that solves your problem.

NOTE: The onbeforeunload method should return a string.

MySQL add days to a date

This query stands good for fetching the values between current date and its next 3 dates

SELECT * FROM tableName
WHERE columName BETWEEN CURDATE() AND DATE_ADD(CURDATE(), INTERVAL 3 DAY)

This will eventually add extra 3 days of buffer to the current date.

selected value get from db into dropdown select box option using php mysql error

THE EASIEST SOLUTION

It will add an extra in your options but your problem will be solved.

<?php 
    if ($editing == Yes) {
        echo "<option value=\".$MyValue.\" SELECTED>".$MyValue."</option>";
    }
?>

MySQL vs MongoDB 1000 reads

On Single Server, MongoDb would not be any faster than mysql MyISAM on both read and write, given table/doc sizes are small 1 GB to 20 GB.
MonoDB will be faster on Parallel Reduce on Multi-Node clusters, where Mysql can NOT scale horizontally.

Error:Unknown host services.gradle.org. You may need to adjust the proxy settings in Gradle

If you are using an http proxy server, revise the following proxy settings in "gradle.properties" file in your project's root folder. If not using proxy server, just delete those entries.

systemProp.http.proxyPort=8080
systemProp.http.proxyUser=UserName
systemProp.http.proxyPassword=Passw0rd
systemProp.https.proxyPassword=Passw0rd
systemProp.https.proxyHost=proxy.abc.com
systemProp.http.proxyHost=proxy.abc.com
systemProp.https.proxyPort=8080
systemProp.https.proxyUser=UserName

jQuery document.createElement equivalent?

Though this is a very old question, I thought it would be nice to update it with recent information;

Since jQuery 1.8 there is a jQuery.parseHTML() function which is now a preferred way of creating elements. Also, there are some issues with parsing HTML via $('(html code goes here)'), fo example official jQuery website mentions the following in one of their release notes:

Relaxed HTML parsing: You can once again have leading spaces or newlines before tags in $(htmlString). We still strongly advise that you use $.parseHTML() when parsing HTML obtained from external sources, and may be making further changes to HTML parsing in the future.

To relate to the actual question, provided example could be translated to:

this.$OuterDiv = $($.parseHTML('<div></div>'))
    .hide()
    .append($($.parseHTML('<table></table>'))
        .attr({ cellSpacing : 0 })
        .addClass("text")
    )
;

which is unfortunately less convenient than using just $(), but it gives you more control, for example you may choose to exclude script tags (it will leave inline scripts like onclick though):

> $.parseHTML('<div onclick="a"></div><script></script>')
[<div onclick=?"a">?</div>?]

> $.parseHTML('<div onclick="a"></div><script></script>', document, true)
[<div onclick=?"a">?</div>?, <script>?</script>?]

Also, here's a benchmark from the top answer adjusted to the new reality:

JSbin Link

jQuery 1.9.1

  $.parseHTML:    88ms
  $($.parseHTML): 240ms
  <div></div>:    138ms
  <div>:          143ms
  createElement:  64ms

It looks like parseHTML is much closer to createElement than $(), but all the boost is gone after wrapping the results in a new jQuery object

M_PI works with math.h but not with cmath in Visual Studio

Consider adding the switch /D_USE_MATH_DEFINES to your compilation command line, or to define the macro in the project settings. This will drag the symbol to all reachable dark corners of include and source files leaving your source clean for multiple platforms. If you set it globally for the whole project, you will not forget it later in a new file(s).

SSH library for Java

The Java Secure Channel (JSCH) is a very popular library, used by maven, ant and eclipse. It is open source with a BSD style license.

Pretty Printing JSON with React

You'll need to either insert BR tag appropriately in the resulting string, or use for example a PRE tag so that the formatting of the stringify is retained:

var data = { a: 1, b: 2 };

var Hello = React.createClass({
    render: function() {
        return <div><pre>{JSON.stringify(data, null, 2) }</pre></div>;
    }
});

React.render(<Hello />, document.getElementById('container'));

Working example.

Update

class PrettyPrintJson extends React.Component {
    render() {
         // data could be a prop for example
         // const { data } = this.props;
         return (<div><pre>{JSON.stringify(data, null, 2) }</pre></div>);
    }
}

ReactDOM.render(<PrettyPrintJson/>, document.getElementById('container'));

Example

Stateless Functional component, React .14 or higher

const PrettyPrintJson = ({data}) => {
    // (destructured) data could be a prop for example
    return (<div><pre>{ JSON.stringify(data, null, 2) }</pre></div>);
}

Or, ...

const PrettyPrintJson = ({data}) => (<div><pre>{ 
    JSON.stringify(data, null, 2) }</pre></div>);

Working example

Memo / 16.6+

(You might even want to use a memo, 16.6+)

const PrettyPrintJson = React.memo(({data}) => (<div><pre>{
    JSON.stringify(data, null, 2) }</pre></div>));

Ruby on Rails: Clear a cached page

This line in development.rb ensures that caching is not happening.

config.action_controller.perform_caching             = false

You can clear the Rails cache with

Rails.cache.clear

That said - I am not convinced this is a caching issue. Are you making changes to the page and not seeing them reflected? You aren't perhaps looking at the live version of that page? I have done that once (blush).

Update:

You can call that command from in the console. Are you sure you are running the application in development?

The only alternative is that the page that you are trying to render isn't the page that is being rendered.

If you watch the server output you should be able to see the render command when the page is rendered similar to this:

Rendered shared_partials/_latest_featured_video (31.9ms)
Rendered shared_partials/_s_invite_friends (2.9ms)
Rendered layouts/_sidebar (2002.1ms)
Rendered layouts/_footer (2.8ms)
Rendered layouts/_busy_indicator (0.6ms)

Java inner class and static nested class

I think that none of the above answers explain to you the real difference between a nested class and a static nested class in term of application design :

OverView

A nested class could be nonstatic or static and in each case is a class defined within another class. A nested class should exist only to serve is enclosing class, if a nested class is useful by other classes (not only the enclosing), should be declared as a top level class.

Difference

Nonstatic Nested class : is implicitly associated with the enclosing instance of the containing class, this means that it is possible to invoke methods and access variables of the enclosing instance. One common use of a nonstatic nested class is to define an Adapter class.

Static Nested Class : can't access enclosing class instance and invoke methods on it, so should be used when the nested class doesn't require access to an instance of the enclosing class . A common use of static nested class is to implement a components of the outer object.

Conclusion

So the main difference between the two from a design standpoint is : nonstatic nested class can access instance of the container class, while static can't.

Cannot get a text value from a numeric cell “Poi”

This is one of the other method to solve the Error: "Cannot get a text value from a numeric cell “Poi”"

Go to the Excel Sheet. Drag and Select the Numerics which you are importing Data from the Excel sheet. Go to Format > Number > Then Select "Plain Text" Then Export as .xlsx. Now Try to Run the Script

Hope works Fine...!

Cannot get a text value from a numeric cell “Poi”.img

ScriptManager.RegisterStartupScript code not working - why?

You must put the updatepanel id in the first argument if the control causing the script is inside the updatepanel else use the keyword 'this' instead of update panel here is the code

ScriptManager.RegisterStartupScript(UpdatePanel3, this.GetType(), UpdatePanel3.UniqueID, "showError();", true);

Determine if a String is an Integer in Java

You can use Integer.parseInt() or Integer.valueOf() to get the integer from the string, and catch the exception if it is not a parsable int. You want to be sure to catch the NumberFormatException it can throw.

It may be helpful to note that valueOf() will return an Integer object, not the primitive int.

Comparing Class Types in Java

As said earlier, your code will work unless you have the same classes loaded on two different class loaders. This might happen in case you need multiple versions of the same class in memory at the same time, or you are doing some weird on the fly compilation stuff (as I am).

In this case, if you want to consider these as the same class (which might be reasonable depending on the case), you can match their names to compare them.

public static boolean areClassesQuiteTheSame(Class<?> c1, Class<?> c2) {
  // TODO handle nulls maybe?
  return c1.getCanonicalName().equals(c2.getCanonicalName());
}

Keep in mind that this comparison will do just what it does: compare class names; I don't think you will be able to cast from one version of a class to the other, and before looking into reflection, you might want to make sure there's a good reason for your classloader mess.

Command to close an application of console?

You can Try This

Application.Exit();

From inside of a Docker container, how do I connect to the localhost of the machine?

For macOS and Windows

Docker v 18.03 and above (since March 21st 2018)

Use your internal IP address or connect to the special DNS name host.docker.internal which will resolve to the internal IP address used by the host.

Linux support pending https://github.com/docker/for-linux/issues/264

MacOS with earlier versions of Docker

Docker for Mac v 17.12 to v 18.02

Same as above but use docker.for.mac.host.internal instead.

Docker for Mac v 17.06 to v 17.11

Same as above but use docker.for.mac.localhost instead.

Docker for Mac 17.05 and below

To access host machine from the docker container you must attach an IP alias to your network interface. You can bind whichever IP you want, just make sure you're not using it to anything else.

sudo ifconfig lo0 alias 123.123.123.123/24

Then make sure that you server is listening to the IP mentioned above or 0.0.0.0. If it's listening on localhost 127.0.0.1 it will not accept the connection.

Then just point your docker container to this IP and you can access the host machine!

To test you can run something like curl -X GET 123.123.123.123:3000 inside the container.

The alias will reset on every reboot so create a start-up script if necessary.

Solution and more documentation here: https://docs.docker.com/docker-for-mac/networking/#use-cases-and-workarounds

How to remove items from a list while iterating?

If you want to do anything else during the iteration, it may be nice to get both the index (which guarantees you being able to reference it, for example if you have a list of dicts) and the actual list item contents.

inlist = [{'field1':10, 'field2':20}, {'field1':30, 'field2':15}]    
for idx, i in enumerate(inlist):
    do some stuff with i['field1']
    if somecondition:
        xlist.append(idx)
for i in reversed(xlist): del inlist[i]

enumerate gives you access to the item and the index at once. reversed is so that the indices that you're going to later delete don't change on you.

AngularJS: How can I pass variables between controllers?

There are two ways to do this

1) Use get/set service

2) $scope.$emit('key', {data: value}); //to set the value

 $rootScope.$on('key', function (event, data) {}); // to get the value

Web Reference vs. Service Reference

In the end, both do the same thing. There are some differences in code: Web Services doesn't add a Root namespace of project, but Service Reference adds service classes to the namespace of the project. The ServiceSoapClient class gets a different naming, which is not important. In working with TFS I'd rather use Service Reference because it works better with source control. Both work with SOAP protocols.

I find it better to use the Service Reference because it is new and will thus be better maintained.

Change SQLite database mode to read-write

I solved this by changing owner from root to me on all files on /db dir.

Just do ls -l on that folder, if any of the filer is owned by root just change it to you, using: sudo chown user file

Android - Best and safe way to stop thread

This worked for me like this. Introduce a static variable in main activity and regularly check for it how i did was below.

public class MainActivity extends AppCompatActivity {


//This is the static variable introduced in main activity
public static boolean stopThread =false;



  protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Thread thread = new Thread(new Thread1());
    thread.start();

    Button stp_thread= findViewById(R.id.button_stop);

    stp_thread.setOnClickListener(new Button.OnClickListener(){
           @Override
           public void onClick(View v){
              stopThread = true;
           }

     }

  }


  class Thread1 implements Runnable{

        public void run() {

        // YOU CAN DO IT ON BELOW WAY 
        while(!MainActivity.stopThread) {
             Do Something here
        }


        //OR YOU CAN CALL RETURN AFTER EVERY LINE LIKE BELOW

        process 1 goes here;

        //Below method also could be used
        if(stopThread==true){
            return ;
        }
        // use this after every line



        process 2 goes here;


        //Below method also could be used
        if(stopThread==true){
            return ;
        }
        // use this after every line


        process 3 goes here;


        //Below method also could be used
        if(stopThread==true){
            return ;
        }
        // use this after every line


        process 4 goes here;



       }
   }

}

PHP salt and hash SHA256 for login password

According to php.net the Salt option has been deprecated as of PHP 7.0.0, so you should use the salt that is generated by default and is far more simpler

Example for store the password:

$hashPassword = password_hash("password", PASSWORD_BCRYPT);

Example to verify the password:

$passwordCorrect = password_verify("password", $hashPassword);

Limiting floats to two decimal points

Most numbers cannot be exactly represented in floats. If you want to round the number because that's what your mathematical formula or algorithm requires, then you want to use round. If you just want to restrict the display to a certain precision, then don't even use round and just format it as that string. (If you want to display it with some alternate rounding method, and there are tons, then you need to mix the two approaches.)

>>> "%.2f" % 3.14159
'3.14'
>>> "%.2f" % 13.9499999
'13.95'

And lastly, though perhaps most importantly, if you want exact math then you don't want floats at all. The usual example is dealing with money and to store 'cents' as an integer.

Hide the browse button on a input type=file

Oddly enough, this works for me (when I place inside a button tag).

.button {
    position: relative;

    input[type=file] {
            color: transparent;
            background-color: transparent;
            position: absolute;
            left: 0;
            width: 100%;
            height: 100%;
            top: 0;
            opacity: 0;
            z-index: 100;
        }
}

Only tested in Chrome (macOS Sierra).

PG::ConnectionBad - could not connect to server: Connection refused

The Homebrew package manager includes launchctl plists to start automatically. For more information run brew info postgres.

Start manually:

pg_ctl -D /usr/local/var/postgres start

Stop manually:

pg_ctl -D /usr/local/var/postgres stop

Start automatically:

"To have launchd start postgresql now and restart at login:"

brew services start postgresql

Validating a Textbox field for only numeric input.

I know this is an old question but I figured out I should pitch my answer anyways.

The following snippet iterates through each character of the text and uses the IsNumber() method, which returns true if the character is a number and false the other way, to check if all the characters are numbers. If all are numbers, the method returns true. If not it returns false.

using System;

private bool ValidateText(string text){
    char[] characters = text.ToCharArray();

    foreach(char c in characters){
        if(!char.IsNumber(c))
            return false;
    }
    return true;
}

How to delete large data of table in SQL without log?

Another use:

SET ROWCOUNT 1000 -- Buffer

DECLARE @DATE AS DATETIME = dateadd(MONTH,-7,GETDATE())

DELETE LargeTable  WHERE readTime < @DATE
WHILE @@ROWCOUNT > 0
BEGIN
   DELETE LargeTable  WHERE readTime < @DATE
END
SET ROWCOUNT 0

Optional;

If transaction log is enabled, disable transaction logs.

ALTER DATABASE dbname SET RECOVERY SIMPLE;

Copy and Paste a set range in the next empty row

You could also try this

Private Sub CommandButton1_Click()

Sheets("Sheet1").Range("A3:E3").Copy

Dim lastrow As Long
lastrow = Range("A65536").End(xlUp).Row

Sheets("Summary Info").Activate
Cells(lastrow + 1, 1).PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks:=False, Transpose:=False

End Sub

SQL LEFT-JOIN on 2 fields for MySQL

Let's try this way:

select 
    a.ip, 
    a.os, 
    a.hostname, 
    a.port, 
    a.protocol, 
    b.state
from a
left join b 
    on a.ip = b.ip 
        and a.port = b.port /*if you has to filter by columns from right table , then add this condition in ON clause*/
where a.somecolumn = somevalue /*if you have to filter by some column from left table, then add it to where condition*/

So, in where clause you can filter result set by column from right table only on this way:

...
where b.somecolumn <> (=) null

Adding System.Web.Script reference in class library

You need to add a reference to System.Web.Extensions.dll in project for System.Web.Script.Serialization error.

How to diff a commit with its parent?

Use git show $COMMIT. It'll show you the log message for the commit, and the diff of that particular commit.

How to compare strings in C conditional preprocessor-directives

As already stated above, the ISO-C11 preprocessor does not support string comparison. However, the problem of assigning a macro with the “opposite value” can be solved with “token pasting” and “table access”. Jesse’s simple concatenate/stringify macro-solution fails with gcc 5.4.0 because the stringization is done before the evaluation of the concatenation (conforming to ISO C11). However, it can be fixed:

#define P_(user) user ## _VS
#define VS(user) P_ (user)
#define S(U) S_(U)
#define S_(U) #U

#define jack_VS  queen
#define queen_VS jack

S (VS (jack))
S (jack)
S (VS (queen))
S (queen)

#define USER jack          // jack    or queen, your choice
#define USER_VS USER##_VS  // jack_VS or queen_VS
S (USER)
S (USER_VS)

The first line (macro P_()) adds one indirection to let the next line (macro VS()) finish the concatenation before the stringization (see Why do I need double layer of indirection for macros?). The stringization macros (S() and S_()) are from Jesse.

The table (macros jack_VS and queen_VS) which is much easier to maintain than the if-then-else construction of the OP is from Jesse.

Finally, the next four-line block invokes the function-style macros. The last four-line block is from Jesse’s answer.

Storing the code in foo.c and invoking the preprocessor gcc -nostdinc -E foo.c yields:

# 1 "foo.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "foo.c"
# 9 "foo.c"
"queen"
"jack"
"jack"
"queen"



"jack"
"USER_VS"

The output is as expected. The last line shows that the USER_VS macro is not expanded before stringization.

How to make HTML element resizable using pure Javascript?

I really recommend using some sort of library, but you asked for it, you get it:

var p = document.querySelector('p'); // element to make resizable

p.addEventListener('click', function init() {
    p.removeEventListener('click', init, false);
    p.className = p.className + ' resizable';
    var resizer = document.createElement('div');
    resizer.className = 'resizer';
    p.appendChild(resizer);
    resizer.addEventListener('mousedown', initDrag, false);
}, false);

var startX, startY, startWidth, startHeight;

function initDrag(e) {
   startX = e.clientX;
   startY = e.clientY;
   startWidth = parseInt(document.defaultView.getComputedStyle(p).width, 10);
   startHeight = parseInt(document.defaultView.getComputedStyle(p).height, 10);
   document.documentElement.addEventListener('mousemove', doDrag, false);
   document.documentElement.addEventListener('mouseup', stopDrag, false);
}

function doDrag(e) {
   p.style.width = (startWidth + e.clientX - startX) + 'px';
   p.style.height = (startHeight + e.clientY - startY) + 'px';
}

function stopDrag(e) {
    document.documentElement.removeEventListener('mousemove', doDrag, false);
    document.documentElement.removeEventListener('mouseup', stopDrag, false);
}

Demo

Remember that this may not run in all browsers (tested only in Firefox, definitely not working in IE <9).

How to return multiple values in one column (T-SQL)?

DECLARE @Str varchar(500)

SELECT @Str=COALESCE(@Str,'') + CAST(ID as varchar(10)) + ','
FROM dbo.fcUser

SELECT @Str

MVC Razor view nested foreach's model

Another much simpler possibility is that one of your property names is wrong (probably one you just changed in the class). This is what it was for me in RazorPages .NET Core 3.

Initialize a Map containing arrays

Per Mozilla's Map documentation, you can initialize as follows:

private _gridOptions:Map<string, Array<string>> = 
    new Map([
        ["1", ["test"]],
        ["2", ["test2"]]
    ]);

How to get the contents of a webpage in a shell variable?

There is the wget command or the curl.

You can now use the file you downloaded with wget. Or you can handle a stream with curl.


Resources :

Complex CSS selector for parent of active child

Many people answered with jQuery parent, but just to add on to that I wanted to share a quick snippet of code that I use for adding classes to my navs so I can add styling to li's that only have sub-menus and not li's that don't.

$("li ul").parent().addClass('has-sub');

How to remove a key from Hash and get the remaining hash in Ruby/Rails?

It's was great if delete return the delete pair of the hash. I'm doing this:

hash = {a: 1, b: 2, c: 3}
{b: hash.delete(:b)} # => {:b=>2}
hash  # => {:a=>1, :c=>3} 

Encode String to UTF-8

How about using

ByteBuffer byteBuffer = StandardCharsets.UTF_8.encode(myString)

How do you access the value of an SQL count () query in a Java program

I have done it this way (example):

String query="SELECT count(t1.id) from t1, t2 where t1.id=t2.id and t2.email='"[email protected]"'";
int count=0;
try {
    ResultSet rs = DatabaseService.statementDataBase().executeQuery(query);
    while(rs.next())
        count=rs.getInt(1);
} catch (SQLException e) {
    e.printStackTrace();
} finally {
    //...
}

AngularJS - Any way for $http.post to send request parameters instead of JSON?

I have problems as well with setting custom http authentication because $resource cache the request.

To make it work you have to overwrite the existing headers by doing this

var transformRequest = function(data, headersGetter){
  var headers = headersGetter();
  headers['Authorization'] = 'WSSE profile="UsernameToken"';
  headers['X-WSSE'] = 'UsernameToken ' + nonce
  headers['Content-Type'] = 'application/json';
};

return $resource(
  url,
    {
    },
    {
      query: {
        method: 'POST',
        url: apiURL + '/profile',
        transformRequest: transformRequest,
        params: {userId: '@userId'}
      },
    }
);

I hope I was able to help someone. It took me 3 days to figure this one out.

What is the proper way to display the full InnerException?

If you want information about all exceptions then use exception.ToString(). It will collect data from all inner exceptions.

If you want only the original exception then use exception.GetBaseException().ToString(). This will get you the first exception, e.g. the deepest inner exception or the current exception if there is no inner exception.

Example:

try {
    Exception ex1 = new Exception( "Original" );
    Exception ex2 = new Exception( "Second", ex1 );
    Exception ex3 = new Exception( "Third", ex2 );
    throw ex3;
} catch( Exception ex ) {
    // ex => ex3
    Exception baseEx = ex.GetBaseException(); // => ex1
}

Using the Jersey client to do a POST operation

If you need to do a file upload, you'll need to use MediaType.MULTIPART_FORM_DATA_TYPE. Looks like MultivaluedMap cannot be used with that so here's a solution with FormDataMultiPart.

InputStream stream = getClass().getClassLoader().getResourceAsStream(fileNameToUpload);

FormDataMultiPart part = new FormDataMultiPart();
part.field("String_key", "String_value");
part.field("fileToUpload", stream, MediaType.TEXT_PLAIN_TYPE);
String response = WebResource.type(MediaType.MULTIPART_FORM_DATA_TYPE).post(String.class, part);

Error handling in AngularJS http get then construct

Try this

function sendRequest(method, url, payload, done){

        var datatype = (method === "JSONP")? "jsonp" : "json";
        $http({
                method: method,
                url: url,
                dataType: datatype,
                data: payload || {},
                cache: true,
                timeout: 1000 * 60 * 10
        }).then(
            function(res){
                done(null, res.data); // server response
            },
            function(res){
                responseHandler(res, done);
            }
        );

    }
    function responseHandler(res, done){
        switch(res.status){
            default: done(res.status + ": " + res.statusText);
        }
    }

Truncate number to two decimal places without rounding

All these answers seem a bit complicated. I would just subtract 0.5 from your number and use toFixed().

Is null reference possible?

clang++ 3.5 even warns on it:

/tmp/a.C:3:7: warning: reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to
      always evaluate to false [-Wtautological-undefined-compare]
if( & nullReference == 0 ) // null reference
      ^~~~~~~~~~~~~    ~
1 warning generated.

How do I get an element to scroll into view, using jQuery?

There are methods to scroll element directly into the view, but if you want to scroll to a point relative from an element, you have to do it manually:

Inside the click handler, get the position of the element relative to the document, subtract 20 and use window.scrollTo:

var pos = $(this).offset();
var top = pos.top - 20;
var left = pos.left - 20;
window.scrollTo((left < 0 ? 0 : left), (top < 0 ? 0 : top));

Adding dictionaries together, Python

If you're interested in creating a new dict without using intermediary storage: (this is faster, and in my opinion, cleaner than using dict.items())

dic2 = dict(dic0, **dic1)

Or if you're happy to use one of the existing dicts:

dic0.update(dic1)

Comparing the contents of two files in Sublime Text

There are a number of diff plugins available via Package Control. I've used Sublimerge Pro, which worked well enough, but it's a commercial product (with an unlimited trial period) and closed-source, so you can't tweak it if you want to change something, or just look at its internals. FileDiffs is quite popular, judging by the number of installs, so you might want to try that one out.

Loop through list with both content and index

Like everyone else:

for i, val in enumerate(data):
    print i, val

but also

for i, val in enumerate(data, 1):
    print i, val

In other words, you can specify as starting value for the index/count generated by enumerate() which comes in handy if you don't want your index to start with the default value of zero.

I was printing out lines in a file the other day and specified the starting value as 1 for enumerate(), which made more sense than 0 when displaying information about a specific line to the user.

How to remove text before | character in notepad++

To replace anything that starts with "text" until the last character:

text.+(.*)$

Example

text             hsjh sdjh sd          jhsjhsdjhsdj hsd
                                                      ^
                                                      last character


To replace anything that starts with "text" until "123"

text.+(\ 123)

Example

text fuhfh283nfnd03no3 d90d3nd 3d 123 udauhdah au dauh ej2e
^                                   ^
From here                     To here

Private properties in JavaScript ES6 classes

In fact it is possible using Symbols and Proxies. You use the symbols in the class scope and set two traps in a proxy: one for the class prototype so that the Reflect.ownKeys(instance) or Object.getOwnPropertySymbols doesn't give your symbols away, the other one is for the constructor itself so when new ClassName(attrs) is called, the instance returned will be intercepted and have the own properties symbols blocked. Here's the code:

_x000D_
_x000D_
const Human = (function() {_x000D_
  const pet = Symbol();_x000D_
  const greet = Symbol();_x000D_
_x000D_
  const Human = privatizeSymbolsInFn(function(name) {_x000D_
    this.name = name; // public_x000D_
    this[pet] = 'dog'; // private _x000D_
  });_x000D_
_x000D_
  Human.prototype = privatizeSymbolsInObj({_x000D_
    [greet]() { // private_x000D_
      return 'Hi there!';_x000D_
    },_x000D_
    revealSecrets() {_x000D_
      console.log(this[greet]() + ` The pet is a ${this[pet]}`);_x000D_
    }_x000D_
  });_x000D_
_x000D_
  return Human;_x000D_
})();_x000D_
_x000D_
const bob = new Human('Bob');_x000D_
_x000D_
console.assert(bob instanceof Human);_x000D_
console.assert(Reflect.ownKeys(bob).length === 1) // only ['name']_x000D_
console.assert(Reflect.ownKeys(Human.prototype).length === 1 ) // only ['revealSecrets']_x000D_
_x000D_
_x000D_
// Setting up the traps inside proxies:_x000D_
function privatizeSymbolsInObj(target) { _x000D_
  return new Proxy(target, { ownKeys: Object.getOwnPropertyNames });_x000D_
}_x000D_
_x000D_
function privatizeSymbolsInFn(Class) {_x000D_
  function construct(TargetClass, argsList) {_x000D_
    const instance = new TargetClass(...argsList);_x000D_
    return privatizeSymbolsInObj(instance);_x000D_
  }_x000D_
  return new Proxy(Class, { construct });_x000D_
}
_x000D_
_x000D_
_x000D_

Reflect.ownKeys() works like so: Object.getOwnPropertyNames(myObj).concat(Object.getOwnPropertySymbols(myObj)) that's why we need a trap for these objects.

Create Elasticsearch curl query for not null and not empty("")

Here's the query example to check the existence of multiple fields:

{
  "query": {
    "bool": {
      "filter": [
        {
          "exists": {
            "field": "field_1"
          }
        },
        {
          "exists": {
            "field": "field_2"
          }
        },
        {
          "exists": {
            "field": "field_n"
          }
        }
      ]
    }
  }
}

What does 'foo' really mean?

foo is used as a place-holder name, usually in example code to signify that the object being named, or the choice of name, is not part of the crux of the example. foo is often followed by bar, baz, and even bundy, if more than one such name is needed. Wikipedia calls these names Metasyntactic Variables. Python programmers supposedly use spam, eggs, ham, instead of foo, etc.

There are good uses of foo in SA.

I have also seen foo used when the programmer can't think of a meaningful name (as a substitute for tmp, say), but I consider that to be a misuse of foo.

How to find cube root using Python?

def cube(x):
    if 0<=x: return x**(1./3.)
    return -(-x)**(1./3.)
print (cube(8))
print (cube(-8))

Here is the full answer for both negative and positive numbers.

>>> 
2.0
-2.0
>>> 

Or here is a one-liner;

root_cube = lambda x: x**(1./3.) if 0<=x else -(-x)**(1./3.)

strcpy() error in Visual studio 2012

If you are getting an error saying something about deprecated functions, try doing #define _CRT_SECURE_NO_WARNINGS or #define _CRT_SECURE_NO_DEPRECATE. These should fix it. You can also use Microsoft's "secure" functions, if you want.

How to open an existing project in Eclipse?

Just do like below, it helped me after doing like this.

To load existing Eclipse projects in the IDE, you need to import them into the Eclipse workspace.

  1. Click File > Import > General
  2. Click Existing Projects into Workspace.
  3. You can edit the project directly in its original location or choose to create a copy of the project in the workspace.
  4. Select the directory that contains the projects you want to import.
  5. Click Finish. This imports the projects into the current workspace and loads them in the IDE.

Look at this below link for reference. https://www.microfocus.com/documentation/enterprise-developer/ed30/Eclipse/GUID-773A19C7-98B2-442D-9D36-240E20E3F2CE.html

How to Export Private / Secret ASC Key to Decrypt GPG Files

You can export the private key with the command-line tool from GPG. It works on the Windows-shell. Use the following command:

gpg --export-secret-keys

A normal export with --export will not include any private keys, therefore you have to use --export-secret-keys.

Edit:

To sum up the information given in my comments, this is the command that allows you to export a specific key with the ID 1234ABCD to the file secret.asc:

gpg --export-secret-keys --armor 1234ABCD > secret.asc

You can find the ID that you need using the following command. The ID is the second part of the second column:

gpg --list-keys

To Export just 1 specific secret key instead of all of them:

gpg --export-secret-keys keyIDNumber > exportedKeyFilename.asc

keyIDNumber is the number of the key id for the desired key you are trying to export.

WebView and HTML5 <video>

I had a similar problem. I had HTML files and videos in the assets-folder of my app.

Therefore the videos were located inside of the APK. Because the APK is really a ZIP-file, the WebView was not able to read the video-files.

Copying all HTML- and video-files onto the SD-Card worked for me.

Block direct access to a file over http but allow php script access

If you have access to you httpd.conf file (in ubuntu it is in the /etc/apache2 directory), you should add the same lines that you would to the .htaccess file in the specific directory. That is (for example):

ServerName YOURSERVERNAMEHERE
<Directory /var/www/>
AllowOverride None
order deny,allow
Options -Indexes FollowSymLinks
</Directory>

Do this for every directory that you want to control the information, and you will have one file in one spot to manage all access. It the example above, I did it for the root directory, /var/www.

This option may not be available with outsourced hosting, especially shared hosting. But it is a better option than adding many .htaccess files.

jQuery serialize does not register checkboxes

var checkboxes = $('#myform').find('input[type="checkbox"]');
$.each( checkboxes, function( key, value ) {
    if (value.checked === false) {
        value.value = 0;
    } else {
        value.value = 1;
    }
    $(value).attr('type', 'hidden');
});
$('#myform').serialize();

CSS disable hover effect

From your question all I can understand is that you already have some hover effect on your button which you want remove. For that either remove that css which causes the hover effect or override it.

For overriding, do this

.buttonDisabled:hover
{
    //overriding css goes here
}

For example if your button's background color changes on hover from red to blue. In the overriding css you will make it as red so that it doesnt change.

Also go through all the rules of writing and overriding css. Get familiar with what css will have what priority.

Best of luck.

Linux/Unix command to determine if process is running?

You SHOULD know the PID !

Finding a process by trying to do some kind of pattern recognition on the process arguments (like pgrep "mysqld") is a strategy that is doomed to fail sooner or later. What if you have two mysqld running? Forget that approach. You MAY get it right temporarily and it MAY work for a year or two but then something happens that you haven't thought about.

Only the process id (pid) is truly unique.

Always store the pid when you launch something in the background. In Bash this can be done with the $! Bash variable. You will save yourself SO much trouble by doing so.

How to determine if process is running (by pid)

So now the question becomes how to know if a pid is running.

Simply do:

ps -o pid= -p <pid>

This is POSIX and hence portable. It will return the pid itself if the process is running or return nothing if the process is not running. Strictly speaking the command will return a single column, the pid, but since we've given that an empty title header (the stuff immediately preceding the equals sign) and this is the only column requested then the ps command will not use header at all. Which is what we want because it makes parsing easier.

This will work on Linux, BSD, Solaris, etc.

Another strategy would be to test on the exit value from the above ps command. It should be zero if the process is running and non-zero if it isn't. The POSIX spec says that ps must exit >0 if an error has occurred but it is unclear to me what constitutes 'an error'. Therefore I'm not personally using that strategy although I'm pretty sure it will work as well on all Unix/Linux platforms.

How to display multiple images in one figure correctly?

You could try the following:

import matplotlib.pyplot as plt
import numpy as np

def plot_figures(figures, nrows = 1, ncols=1):
    """Plot a dictionary of figures.

    Parameters
    ----------
    figures : <title, figure> dictionary
    ncols : number of columns of subplots wanted in the display
    nrows : number of rows of subplots wanted in the figure
    """

    fig, axeslist = plt.subplots(ncols=ncols, nrows=nrows)
    for ind,title in zip(range(len(figures)), figures):
        axeslist.ravel()[ind].imshow(figures[title], cmap=plt.jet())
        axeslist.ravel()[ind].set_title(title)
        axeslist.ravel()[ind].set_axis_off()
    plt.tight_layout() # optional



# generation of a dictionary of (title, images)
number_of_im = 20
w=10
h=10
figures = {'im'+str(i): np.random.randint(10, size=(h,w)) for i in range(number_of_im)}

# plot of the images in a figure, with 5 rows and 4 columns
plot_figures(figures, 5, 4)

plt.show()

However, this is basically just copy and paste from here: Multiple figures in a single window for which reason this post should be considered to be a duplicate.

I hope this helps.

Angular 4/5/6 Global Variables

You can use the Window object and access it everwhere. example window.defaultTitle = "my title"; then you can access window.defaultTitle without importing anything.

Custom Adapter for List View

It is very simple.

import android.content.Context;
import android.content.DialogInterface;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.app.AlertDialog;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.List;

/**
 * Created by Belal on 9/14/2017.
 */

//we need to extend the ArrayAdapter class as we are building an adapter
public class MyListAdapter extends ArrayAdapter<Hero> {

    //the list values in the List of type hero 
    List<Hero> heroList;

    //activity context 
    Context context;

    //the layout resource file for the list items
    int resource;

    //constructor initializing the values 
    public MyListAdapter(Context context, int resource, List<Hero> heroList) {
        super(context, resource, heroList);
        this.context = context;
        this.resource = resource;
        this.heroList = heroList;
    }

    //this will return the ListView Item as a View
    @NonNull
    @Override
    public View getView(final int position, @Nullable View convertView, @NonNull ViewGroup parent) {

        //we need to get the view of the xml for our list item
        //And for this we need a layoutinflater
        LayoutInflater layoutInflater = LayoutInflater.from(context);

        //getting the view
        View view = layoutInflater.inflate(resource, null, false);

        //getting the view elements of the list from the view
        ImageView imageView = view.findViewById(R.id.imageView);
        TextView textViewName = view.findViewById(R.id.textViewName);
        TextView textViewTeam = view.findViewById(R.id.textViewTeam);
        Button buttonDelete = view.findViewById(R.id.buttonDelete);

        //getting the hero of the specified position
        Hero hero = heroList.get(position);

        //adding values to the list item 
        imageView.setImageDrawable(context.getResources().getDrawable(hero.getImage()));
        textViewName.setText(hero.getName());
        textViewTeam.setText(hero.getTeam());

        //adding a click listener to the button to remove item from the list
        buttonDelete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //we will call this method to remove the selected value from the list
                //we are passing the position which is to be removed in the method 
                removeHero(position);
            }
        });

        //finally returning the view
        return view;
    }

    //this method will remove the item from the list 
    private void removeHero(final int position) {
        //Creating an alert dialog to confirm the deletion
        AlertDialog.Builder builder = new AlertDialog.Builder(context);
        builder.setTitle("Are you sure you want to delete this?");

        //if the response is positive in the alert 
        builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {

                //removing the item 
                heroList.remove(position);

                //reloading the list 
                notifyDataSetChanged();
            }
        });

        //if response is negative nothing is being done 
        builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {

            }
        });

        //creating and displaying the alert dialog 
        AlertDialog alertDialog = builder.create();
        alertDialog.show();
    }
}

Source: Custom ListView Android Tutorial

groovy: safely find a key in a map and return its value

The reason you get a Null Pointer Exception is because there is no key likesZZZ in your second example. Try:

def mymap = [name:"Gromit", likes:"cheese", id:1234]
def x = mymap.find{ it.key == "likes" }.value
if(x)
    println "x value: ${x}"

How to set a selected option of a dropdown list control using angular JS

JS:

$scope.options = [
  {
    name: "a", 
    id: 1 
  },
  {
    name: "b",
    id: 2 
  }
];
$scope.selectedOption = $scope.options[1];

SQL Query to find missing rows between two related tables

SELECT A.ABC_ID, A.VAL FROM A WHERE NOT EXISTS 
   (SELECT * FROM B WHERE B.ABC_ID = A.ABC_ID AND B.VAL = A.VAL)

or

SELECT A.ABC_ID, A.VAL FROM A WHERE VAL NOT IN 
    (SELECT VAL FROM B WHERE B.ABC_ID = A.ABC_ID)

or

SELECT A.ABC_ID, A.VAL LEFT OUTER JOIN B 
    ON A.ABC_ID = B.ABC_ID AND A.VAL = B.VAL FROM A WHERE B.VAL IS NULL

Please note that these queries do not require that ABC_ID be in table B at all. I think that does what you want.

How to break out of multiple loops?

This isn't the prettiest way to do it, but in my opinion, it's the best way.

def loop():
    while True:
    #snip: print out current state
        while True:
            ok = get_input("Is this ok? (y/n)")
            if ok == "y" or ok == "Y": return
            if ok == "n" or ok == "N": break
        #do more processing with menus and stuff

I'm pretty sure you could work out something using recursion here as well, but I don't know if that's a good option for you.

What's the difference between "static" and "static inline" function?

inline instructs the compiler to attempt to embed the function content into the calling code instead of executing an actual call.

For small functions that are called frequently that can make a big performance difference.

However, this is only a "hint", and the compiler may ignore it, and most compilers will try to "inline" even when the keyword is not used, as part of the optimizations, where its possible.

for example:

static int Inc(int i) {return i+1};
.... // some code
int i;
.... // some more code
for (i=0; i<999999; i = Inc(i)) {/*do something here*/};

This tight loop will perform a function call on each iteration, and the function content is actually significantly less than the code the compiler needs to put to perform the call. inline will essentially instruct the compiler to convert the code above into an equivalent of:

 int i;
 ....
 for (i=0; i<999999; i = i+1) { /* do something here */};

Skipping the actual function call and return

Obviously this is an example to show the point, not a real piece of code.

static refers to the scope. In C it means that the function/variable can only be used within the same translation unit.

Why doesn't Python have a sign function?

Since cmp has been removed, you can get the same functionality with

def cmp(a, b):
    return (a > b) - (a < b)

def sign(a):
    return (a > 0) - (a < 0)

It works for float, int and even Fraction. In the case of float, notice sign(float("nan")) is zero.

Python doesn't require that comparisons return a boolean, and so coercing the comparisons to bool() protects against allowable, but uncommon implementation:

def sign(a):
    return bool(a > 0) - bool(a < 0)

how to convert binary string to decimal?

        var num = 10;

        alert("Binary " + num.toString(2));   //1010
        alert("Octal " + num.toString(8));    //12
        alert("Hex " + num.toString(16));     //a

        alert("Binary to Decimal "+ parseInt("1010", 2));  //10
        alert("Octal to Decimal " + parseInt("12", 8));    //10
        alert("Hex to Decimal " + parseInt("a", 16));      //10

Launch a shell command with in a python script, wait for the termination and return to the script

subprocess: The subprocess module allows you to spawn new processes, connect to their input/output/error pipes, and obtain their return codes.

http://docs.python.org/library/subprocess.html

Usage:

import subprocess
process = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE)
process.wait()
print process.returncode

Change HTML email body font type and size in VBA

FYI I did a little research as well and if the name of the font-family you want to apply contains spaces (as an example I take Gill Alt One MT Light), you should write it this way :

strbody= "<BODY style=" & Chr(34) & "font-family:Gill Alt One MT Light" & Chr(34) & ">" & YOUR_TEXT & "</BODY>"

Unable to launch the IIS Express Web server, Failed to register URL, Access is denied

In VS2017. I had to edit my .sln file and had to update the VWDPort = "5010" setting. None of the other solutions posted here worked.

Detect if checkbox is checked or unchecked in Angular.js ng-change event

The state of the checkbox will be reflected on whatever model you have it bound to, in this case, $scope.answers[item.questID]

"java.lang.OutOfMemoryError: PermGen space" in Maven build

When I encountered this exception, I solved this by using Run Configurations... panel as picture shows below.Especially, at JRE tab, the VM Arguments are the critical
( "-Xmx1024m -Xms512m -XX:MaxPermSize=1024m -XX:PermSize=512m" ).

enter image description here

How do I specify the exit code of a console application in .NET?

3 options:

  • You can return it from Main if you declare your Main method to return int.
  • You can call Environment.Exit(code).
  • You can set the exit code using properties: Environment.ExitCode = -1;. This will be used if nothing else sets the return code or uses one of the other options above).

Depending on your application (console, service, web app, etc) different methods can be used.

How do I instantiate a JAXBElement<String> object?

Here is how I do it. You will need to get the namespace URL and the element name from your generated code.

new JAXBElement(new QName("http://www.novell.com/role/service","userDN"),
                new String("").getClass(),testDN);

Exception : AAPT2 error: check logs for details

I ran into this very issue today morning and found the solution for it too. This issue is created when you have messed up one of your .xml files. I'll suggest you go through them one by one and look for recent changes made. It might be caused by a silly mistake.

In my case, I accidentally hardcoded a color string as #FFFFF(Bad practice, I know). As you can see it had 5 F instead of 6. It didn't show any warning but was the root of the same issue as encountered by you.

Edit 1: Another thing you can do is to run assembleDebug in your gradle console. It will find the specific line for you.

Edit 2: Adding an image for reference to run assembleDebug.

enter image description here

Preventing iframe caching in browser

Make the URL of the iframe point to a page on your site which acts as a proxy to retrieve and return the actual contents of the iframe. Now you are no longer bound by the same-origin policy (EDIT: does not prevent the iframe caching issue).

Why am I getting error CS0246: The type or namespace name could not be found?

most of the problems cause by .NET Framework. So just go to project properties and change .Net version same as your reference dll.

Done!!!

Hope it's help :)

Could not read JSON: Can not deserialize instance of hello.Country[] out of START_OBJECT token

If you want to avoid using an extra Class and List<Object> genomes you could simply use a Map.

The data structure translates into Map<String, List<Country>>

String resourceEndpoint = "http://api.geonames.org/countryInfoJSON?username=volodiaL";

Map<String, List<Country>> geonames = restTemplate.getForObject(resourceEndpoint, Map.class);

List<Country> countries = geonames.get("geonames");

How to validate domain credentials?

I`m using the following code to validate credentials. The method shown below will confirm if the credentials are correct and if not wether the password is expired or needs change.

I`ve been looking for something like this for ages... So i hope this helps someone!

using System;
using System.DirectoryServices;
using System.DirectoryServices.AccountManagement;
using System.Runtime.InteropServices;

namespace User
{
    public static class UserValidation
    {
        [DllImport("advapi32.dll", SetLastError = true)]
        static extern bool LogonUser(string principal, string authority, string password, LogonTypes logonType, LogonProviders logonProvider, out IntPtr token);
        [DllImport("kernel32.dll", SetLastError = true)]
        static extern bool CloseHandle(IntPtr handle);
        enum LogonProviders : uint
        {
            Default = 0, // default for platform (use this!)
            WinNT35,     // sends smoke signals to authority
            WinNT40,     // uses NTLM
            WinNT50      // negotiates Kerb or NTLM
        }
        enum LogonTypes : uint
        {
            Interactive = 2,
            Network = 3,
            Batch = 4,
            Service = 5,
            Unlock = 7,
            NetworkCleartext = 8,
            NewCredentials = 9
        }
        public  const int ERROR_PASSWORD_MUST_CHANGE = 1907;
        public  const int ERROR_LOGON_FAILURE = 1326;
        public  const int ERROR_ACCOUNT_RESTRICTION = 1327;
        public  const int ERROR_ACCOUNT_DISABLED = 1331;
        public  const int ERROR_INVALID_LOGON_HOURS = 1328;
        public  const int ERROR_NO_LOGON_SERVERS = 1311;
        public  const int ERROR_INVALID_WORKSTATION = 1329;
        public  const int ERROR_ACCOUNT_LOCKED_OUT = 1909;      //It gives this error if the account is locked, REGARDLESS OF WHETHER VALID CREDENTIALS WERE PROVIDED!!!
        public  const int ERROR_ACCOUNT_EXPIRED = 1793;
        public  const int ERROR_PASSWORD_EXPIRED = 1330;

        public static int CheckUserLogon(string username, string password, string domain_fqdn)
        {
            int errorCode = 0;
            using (PrincipalContext pc = new PrincipalContext(ContextType.Domain, domain_fqdn, "ADMIN_USER", "PASSWORD"))
            {
                if (!pc.ValidateCredentials(username, password))
                {
                    IntPtr token = new IntPtr();
                    try
                    {
                        if (!LogonUser(username, domain_fqdn, password, LogonTypes.Network, LogonProviders.Default, out token))
                        {
                            errorCode = Marshal.GetLastWin32Error();
                        }
                    }
                    catch (Exception)
                    {
                        throw;
                    }
                    finally
                    {
                        CloseHandle(token);
                    }
                }
            }
            return errorCode;
        }
    }

How to fix "Root element is missing." when doing a Visual Studio (VS) Build?

In my case, I just renamed the .csproj.user and restart the visual studio and opened the project. It automatically created another .csproj.user file and the solution worked fine for me.

Oracle 'Partition By' and 'Row_Number' keyword

I often use row_number() as a quick way to discard duplicate records from my select statements. Just add a where clause. Something like...

select a,b,rn 
  from (select a, b, row_number() over (partition by a,b order by a,b) as rn           
          from table) 
 where rn=1;

How to get build time stamp from Jenkins build variables?

BUILD_ID used to provide this information but they changed it to provide the Build Number since Jenkins 1.597. Refer this for more information.

You can achieve this using the Build Time Stamp plugin as pointed out in the other answers.

However, if you are not allowed or not willing to use a plugin, follow the below method:

def BUILD_TIMESTAMP = null
withCredentials([usernamePassword(credentialsId: 'JenkinsCredentials', passwordVariable: 'JENKINS_PASSWORD', usernameVariable: 'JENKINS_USERNAME')]) {
   sh(script: "curl https://${JENKINS_USERNAME}:${JENKINS_PASSWORD}@<JENKINS_URL>/job/<JOB_NAME>/lastBuild/buildTimestamp", returnStdout: true).trim();
}
println BUILD_TIMESTAMP

This might seem a bit of overkill but manages to get the job done.

The credentials for accessing your Jenkins should be added and the id needs to be passed in the withCredentials statement, in place of 'JenkinsCredentials'. Feel free to omit that step if your Jenkins doesn't use authentication.

outline on only one border

Try with Shadow( Like border ) + Border

border-bottom: 5px solid #fff;
box-shadow: 0 5px 0 #ffbf0e;

Swift: Display HTML data in a label or textView

Swift 3

extension String {


var html2AttributedString: NSAttributedString? {
    guard
        let data = data(using: String.Encoding.utf8)
        else { return nil }
    do {
        return try NSAttributedString(data: data, options: [NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType,NSCharacterEncodingDocumentAttribute:String.Encoding.utf8], documentAttributes: nil)
    } catch let error as NSError {
        print(error.localizedDescription)
        return  nil
    }
}
var html2String: String {
    return html2AttributedString?.string ?? ""
 }
}