Programs & Examples On #Ascii art

Diagrams, texts and pictures made entirely by stringing together the printable ASCII characters.

Command-line Unix ASCII-based charting / plotting tool

gnuplot is the definitive answer to your question.

I am personally also a big fan of the google chart API, which can be accessed from the command line with the help of wget (or curl) to download a png file (and view with xview or something similar). I like this option because I find the charts to be slightly prettier (i.e. better antialiasing).

MySQL: selecting rows where a column is null

There's also a <=> operator:

SELECT pid FROM planets WHERE userid <=> NULL

Would work. The nice thing is that <=> can also be used with non-NULL values:

SELECT NULL <=> NULL yields 1.

SELECT 42 <=> 42 yields 1 as well.

See here: https://dev.mysql.com/doc/refman/5.7/en/comparison-operators.html#operator_equal-to

Why can't I define my workbook as an object?

You'll need to open the workbook to refer to it.

Sub Setwbk()

    Dim wbk As Workbook

    Set wbk = Workbooks.Open("F:\Quarterly Reports\2012 Reports\New Reports\ _
        Master Benchmark Data Sheet.xlsx")

End Sub

* Follow Doug's answer if the workbook is already open. For the sake of making this answer as complete as possible, I'm including my comment on his answer:

Why do I have to "set" it?

Set is how VBA assigns object variables. Since a Range and a Workbook/Worksheet are objects, you must use Set with these.

What is the difference between Task.Run() and Task.Factory.StartNew()

The Task.Run got introduced in newer .NET framework version and it is recommended.

Starting with the .NET Framework 4.5, the Task.Run method is the recommended way to launch a compute-bound task. Use the StartNew method only when you require fine-grained control for a long-running, compute-bound task.

The Task.Factory.StartNew has more options, the Task.Run is a shorthand:

The Run method provides a set of overloads that make it easy to start a task by using default values. It is a lightweight alternative to the StartNew overloads.

And by shorthand I mean a technical shortcut:

public static Task Run(Action action)
{
    return Task.InternalStartNew(null, action, null, default(CancellationToken), TaskScheduler.Default,
        TaskCreationOptions.DenyChildAttach, InternalTaskOptions.None, ref stackMark);
}

How to push to History in React Router v4?

If you want to use history while passing a function as a value to a Component's prop, with react-router 4 you can simply destructure the history prop in the render attribute of the <Route/> Component and then use history.push()

    <Route path='/create' render={({history}) => (
      <YourComponent
        YourProp={() => {
          this.YourClassMethod()
          history.push('/')
        }}>
      </YourComponent>
    )} />

Note: For this to work you should wrap React Router's BrowserRouter Component around your root component (eg. which might be in index.js)

How do AX, AH, AL map onto EAX?

No, that's not quite right.

EAX is the full 32-bit value
AX is the lower 16-bits
AL is the lower 8 bits
AH is the bits 8 through 15 (zero-based)

So AX is composed of AH:AL halves, and is itself the low half of EAX. (The upper half of EAX isn't directly accessible as a 16-bit register; you can shift or rotate EAX if you want to get at it.)

For completeness, in addition to the above, which was based on a 32-bit CPU, 64-bit Intel/AMD CPUs have

RAX, which hold a 64-bit value, and where EAX is mapped to the lower 32 bits.

All of this also applies to EBX/RBX, ECX/RCX, and EDX/RDX. The other registers like EDI/RDI have a DI low 16-bit partial register, but no high-8 part, and the low-8 DIL is only accessible in 64-bit mode: Assembly registers in 64-bit architecture


Writing AL, AH, or AX merges into the full AX/EAX/RAX, leaving other bytes unmodified for historical reasons. (In 32 or 64-bit code, prefer a movzx eax, byte [mem] or movzx eax, word [mem] load if you don't specifically want this merging: Why doesn't GCC use partial registers?)

Writing EAX zero-extends into RAX. (Why do x86-64 instructions on 32-bit registers zero the upper part of the full 64-bit register?)

Get the date of next monday, tuesday, etc

You can use Carbon library.

Example: Next week friday

Carbon::parse("friday next week");

How do I use itertools.groupby()?

The example on the Python docs is quite straightforward:

groups = []
uniquekeys = []
for k, g in groupby(data, keyfunc):
    groups.append(list(g))      # Store group iterator as a list
    uniquekeys.append(k)

So in your case, data is a list of nodes, keyfunc is where the logic of your criteria function goes and then groupby() groups the data.

You must be careful to sort the data by the criteria before you call groupby or it won't work. groupby method actually just iterates through a list and whenever the key changes it creates a new group.

How to download Visual Studio Community Edition 2015 (not 2017)

The "official" way to get the vs2015 is to go to https://my.visualstudio.com/ ; join the " Visual Studio Dev Essentials" and then search the relevant file to download https://my.visualstudio.com/Downloads?q=Visual%20Studio%202015%20with%20Update%203

display: inline-block extra margin

A year later, stumbled across this question for a inline LI problem, but have found a great solution that may apply here.

http://robertnyman.com/2010/02/24/css-display-inline-block-why-it-rocks-and-why-it-sucks/

vertical-align:bottom on all my LI elements fixed my "extra margin" problem in all browsers.

How to modify list entries during for loop?

In short, to do modification on the list while iterating the same list.

list[:] = ["Modify the list" for each_element in list "Condition Check"]

example:

list[:] = [list.remove(each_element) for each_element in list if each_element in ["data1", "data2"]]

How to modify JsonNode in Java?

I think you can just cast to ObjectNode and use put method. Like this

ObjectNode o = (ObjectNode) jsonNode; o.put("value", "NO");

How does String.Index work in Swift

I appreciate this question and all the info with it. I have something in mind that's kind of a question and an answer when it comes to String.Index.

I'm trying to see if there is an O(1) way to access a Substring (or Character) inside a String because string.index(startIndex, offsetBy: 1) is O(n) speed if you look at the definition of index function. Of course we can do something like:

let characterArray = Array(string)

then access any position in the characterArray however SPACE complexity of this is n = length of string, O(n) so it's kind of a waste of space.

I was looking at Swift.String documentation in Xcode and there is a frozen public struct called Index. We can initialize is as:

let index = String.Index(encodedOffset: 0)

Then simply access or print any index in our String object as such:

print(string[index])

Note: be careful not to go out of bounds`

This works and that's great but what is the run-time and space complexity of doing it this way? Is it any better?

Numpy `ValueError: operands could not be broadcast together with shape ...`

If X and beta do not have the same shape as the second term in the rhs of your last line (i.e. nsample), then you will get this type of error. To add an array to a tuple of arrays, they all must be the same shape.

I would recommend looking at the numpy broadcasting rules.

Extracting jar to specified directory

jars use zip compression so you can use any unzip utility.

Example:

$ unzip myJar.jar -d ./directoryToExtractTo

How to assign name for a screen?

The easiest way use screen with name

screen -S 'name' 'application'
  • Ctrl+a, d = exit and leave application open

Return to screen:

screen -r 'name'

for example using lynx with screen

Create screen:

screen -S lynx lynx

Ctrl+a, d =exit

later you can return with:

screen -r lynx

Accessing Redux state in an action creator?

I wouldn't access state in the Action Creator. I would use mapStateToProps() and import the entire state object and import a combinedReducer file (or import * from './reducers';) in the component the Action Creator is eventually going to. Then use destructuring in the component to use whatever you need from the state prop. If the Action Creator is passing the state onto a Reducer for the given TYPE, you don't need to mention state because the reducer has access to everything that is currently set in state. Your example is not updating anything. I would only use the Action Creator to pass along state from its parameters.

In the reducer do something like:

const state = this.state;
const apple = this.state.apples;

If you need to perform an action on state for the TYPE you are referencing, please do it in the reducer.

Please correct me if I'm wrong!!!

Filter element based on .data() key/value

Sounds like more work than its worth.

1) Why not just have a single JavaScript variable that stores a reference to the currently selected element\jQuery object.

2) Why not add a class to the currently selected element. Then you could query the DOM for the ".active" class or something.

opening a window form from another form programmatically

This is an old question, but answering for gathering knowledge. We have an original form with a button to show the new form.

enter image description here

The code for the button click is below

private void button1_Click(object sender, EventArgs e)
{
    New_Form new_Form = new New_Form();
    new_Form.Show();
}

Now when click is made, New Form is shown. Since, you want to hide after 2 seconds we are adding a onload event to the new form designer

this.Load += new System.EventHandler(this.OnPageLoad);

This OnPageLoad function runs when that form is loaded

In NewForm.cs ,

public partial class New_Form : Form
{
    private Timer formClosingTimer;

    private void OnPageLoad(object sender, EventArgs e)
    {
        formClosingTimer = new Timer();  // Creating a new timer 
        formClosingTimer.Tick += new EventHandler(CloseForm); // Defining tick event to invoke after a time period
        formClosingTimer.Interval = 2000; // Time Interval in miliseconds
        formClosingTimer.Start(); // Starting a timer
    }
    private void CloseForm(object sender, EventArgs e)
    {
        formClosingTimer.Stop(); // Stoping timer. If we dont stop, function will be triggered in regular intervals
        this.Close(); // Closing the current form
    }
}

In this new form , a timer is used to invoke a method which closes that form.

Here is the new form which automatically closes after 2 seconds, we will be able operate on both the forms where no interference between those two forms.

enter image description here

For your knowledge,

form.close() will free the memory and we can never interact with that form again form.hide() will just hide the form, where the code part can still run

For more details about timer refer this link, https://docs.microsoft.com/en-us/dotnet/api/system.timers.timer?view=netframework-4.7.2

Specify system property to Maven project

I have learned it is also possible to do this with the exec-maven-plugin if you're doing a "standalone" java app.

            <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>exec-maven-plugin</artifactId>
            <version>${maven.exec.plugin.version}</version>
            <executions>
                <execution>
                    <goals>
                        <goal>java</goal>
                    </goals>
                </execution>
            </executions>
            <configuration>
                <mainClass>${exec.main-class}</mainClass>
                <systemProperties>
                    <systemProperty>
                        <key>myproperty</key>
                        <value>myvalue</value>
                    </systemProperty>
                </systemProperties>
            </configuration>
        </plugin>

Passing data between different controller action methods

If you need to pass data from one controller to another you must pass data by route values.Because both are different request.if you send data from one page to another then you have to user query string(same as route values).

But you can do one trick :

In your calling action call the called action as a simple method :

public class ServerController : Controller
{
 [HttpPost]
 public ActionResult ApplicationPoolsUpdate(ServiceViewModel viewModel)
 {
      XDocument updatedResultsDocument = myService.UpdateApplicationPools();
      ApplicationPoolController pool=new ApplicationPoolController(); //make an object of ApplicationPoolController class.

      return pool.UpdateConfirmation(updatedResultsDocument); // call the ActionMethod you want as a simple method and pass the model as an argument.
      // Redirect to ApplicationPool controller and pass
      // updatedResultsDocument to be used in UpdateConfirmation action method
 }
}

How can I get the session object if I have the entity-manager?

'entityManager.unwrap(Session.class)' is used to get session from EntityManager.

@Repository
@Transactional
public class EmployeeRepository {

  @PersistenceContext
  private EntityManager entityManager;

  public Session getSession() {
    Session session = entityManager.unwrap(Session.class);
    return session;
  }

  ......
  ......

}

Demo Application link.

How to load image to WPF in runtime?

In WPF an image is typically loaded from a Stream or an Uri.

BitmapImage supports both and an Uri can even be passed as constructor argument:

var uri = new Uri("http://...");
var bitmap = new BitmapImage(uri);

If the image file is located in a local folder, you would have to use a file:// Uri. You could create such a Uri from a path like this:

var path = Path.Combine(Environment.CurrentDirectory, "Bilder", "sas.png");
var uri = new Uri(path);

If the image file is an assembly resource, the Uri must follow the the Pack Uri scheme:

var uri = new Uri("pack://application:,,,/Bilder/sas.png");

In this case the Visual Studio Build Action for sas.png would have to be Resource.

Once you have created a BitmapImage and also have an Image control like in this XAML

<Image Name="image1" />

you would simply assign the BitmapImage to the Source property of that Image control:

image1.Source = bitmap;

Get the first item from an iterable that matches a condition

Similar to using ifilter, you could use a generator expression:

>>> (x for x in xrange(10) if x > 5).next()
6

In either case, you probably want to catch StopIteration though, in case no elements satisfy your condition.

Technically speaking, I suppose you could do something like this:

>>> foo = None
>>> for foo in (x for x in xrange(10) if x > 5): break
... 
>>> foo
6

It would avoid having to make a try/except block. But that seems kind of obscure and abusive to the syntax.

POST request not allowed - 405 Not Allowed - nginx, even with headers included

This configuration to your nginx.conf should help you.

https://gist.github.com/baskaran-md/e46cc25ccfac83f153bb

server {
    listen       80;
    server_name  localhost;

    location / {
        root   html;
        index  index.html index.htm;
    }

    error_page  404     /404.html;
    error_page  403     /403.html;

    # To allow POST on static pages
    error_page  405     =200 $uri;

    # ...
}

How can I create my own comparator for a map?

Since C++11, you can also use a lambda expression instead of defining a comparator struct:

auto comp = [](const string& a, const string& b) { return a.length() < b.length(); };
map<string, string, decltype(comp)> my_map(comp);

my_map["1"]      = "a";
my_map["three"]  = "b";
my_map["two"]    = "c";
my_map["fouuur"] = "d";

for(auto const &kv : my_map)
    cout << kv.first << endl;

Output:

1
two
three
fouuur

I'd like to repeat the final note of Georg's answer: When comparing by length you can only have one string of each length in the map as a key.

Code on Ideone

How to filter Android logcat by application?

I use to store it in a file:

        int pid = android.os.Process.myPid();
        File outputFile = new File(Environment.getExternalStorageDirectory() + "/logs/logcat.txt");
        try {
            String command = "logcat | grep " + pid + " > " + outputFile.getAbsolutePath();
            Process p =  Runtime.getRuntime().exec("su");
            OutputStream os = p.getOutputStream();
            os.write((command + "\n").getBytes("ASCII"));
        } catch (IOException e) {
            e.printStackTrace();
        }

Using Eloquent ORM in Laravel to perform search of database using LIKE

Use double quotes instead of single quote eg :

where('customer.name', 'LIKE', "%$findcustomer%")

Below is my code:

public function searchCustomer($findcustomer)
{
    $customer = DB::table('customer')
                  ->where('customer.name', 'LIKE', "%$findcustomer%")
                  ->orWhere('customer.phone', 'LIKE', "%$findcustomer%")
                  ->get();

    return View::make("your view here");
}

Using group by on multiple columns

In simple English from GROUP BY with two parameters what we are doing is looking for similar value pairs and get the count to a 3rd column.

Look at the following example for reference. Here I'm using International football results from 1872 to 2020

+----------+----------------+--------+---+---+--------+---------+-------------------+-----+
|       _c0|             _c1|     _c2|_c3|_c4|     _c5|      _c6|                _c7|  _c8|
+----------+----------------+--------+---+---+--------+---------+-------------------+-----+
|1872-11-30|        Scotland| England|  0|  0|Friendly|  Glasgow|           Scotland|FALSE|
|1873-03-08|         England|Scotland|  4|  2|Friendly|   London|            England|FALSE|
|1874-03-07|        Scotland| England|  2|  1|Friendly|  Glasgow|           Scotland|FALSE|
|1875-03-06|         England|Scotland|  2|  2|Friendly|   London|            England|FALSE|
|1876-03-04|        Scotland| England|  3|  0|Friendly|  Glasgow|           Scotland|FALSE|
|1876-03-25|        Scotland|   Wales|  4|  0|Friendly|  Glasgow|           Scotland|FALSE|
|1877-03-03|         England|Scotland|  1|  3|Friendly|   London|            England|FALSE|
|1877-03-05|           Wales|Scotland|  0|  2|Friendly|  Wrexham|              Wales|FALSE|
|1878-03-02|        Scotland| England|  7|  2|Friendly|  Glasgow|           Scotland|FALSE|
|1878-03-23|        Scotland|   Wales|  9|  0|Friendly|  Glasgow|           Scotland|FALSE|
|1879-01-18|         England|   Wales|  2|  1|Friendly|   London|            England|FALSE|
|1879-04-05|         England|Scotland|  5|  4|Friendly|   London|            England|FALSE|
|1879-04-07|           Wales|Scotland|  0|  3|Friendly|  Wrexham|              Wales|FALSE|
|1880-03-13|        Scotland| England|  5|  4|Friendly|  Glasgow|           Scotland|FALSE|
|1880-03-15|           Wales| England|  2|  3|Friendly|  Wrexham|              Wales|FALSE|
|1880-03-27|        Scotland|   Wales|  5|  1|Friendly|  Glasgow|           Scotland|FALSE|
|1881-02-26|         England|   Wales|  0|  1|Friendly|Blackburn|            England|FALSE|
|1881-03-12|         England|Scotland|  1|  6|Friendly|   London|            England|FALSE|
|1881-03-14|           Wales|Scotland|  1|  5|Friendly|  Wrexham|              Wales|FALSE|
|1882-02-18|Northern Ireland| England|  0| 13|Friendly|  Belfast|Republic of Ireland|FALSE|
+----------+----------------+--------+---+---+--------+---------+-------------------+-----+

And now I'm going to group by similar country(column _c7) and tournament(_c5) value pairs by GROUP BY operation,

SELECT `_c5`,`_c7`,count(*)  FROM res GROUP BY `_c5`,`_c7`

+--------------------+-------------------+--------+
|                 _c5|                _c7|count(1)|
+--------------------+-------------------+--------+
|            Friendly|  Southern Rhodesia|      11|
|            Friendly|            Ecuador|      68|
|African Cup of Na...|           Ethiopia|      41|
|Gold Cup qualific...|Trinidad and Tobago|       9|
|AFC Asian Cup qua...|             Bhutan|       7|
|African Nations C...|              Gabon|       2|
|            Friendly|           China PR|     170|
|FIFA World Cup qu...|             Israel|      59|
|FIFA World Cup qu...|              Japan|      61|
|UEFA Euro qualifi...|            Romania|      62|
|AFC Asian Cup qua...|              Macau|       9|
|            Friendly|        South Sudan|       1|
|CONCACAF Nations ...|           Suriname|       3|
|         Copa Newton|          Argentina|      12|
|            Friendly|        Philippines|      38|
|FIFA World Cup qu...|              Chile|      68|
|African Cup of Na...|         Madagascar|      29|
|FIFA World Cup qu...|       Burkina Faso|      30|
| UEFA Nations League|            Denmark|       4|
|        Atlantic Cup|           Paraguay|       2|
+--------------------+-------------------+--------+

Explanation: The meaning of the first row is there were 11 Friendly tournaments held on Southern Rhodesia in total.

Note: Here it's mandatory to use a counter column in this case.

count number of rows in a data frame in R based on group

The count() function in plyr does what you want:

library(plyr)

count(mydf, "MONTH-YEAR")

How to scroll the window using JQuery $.scrollTo() function

jQuery now supports scrollTop as an animation variable.

$("#id").animate({"scrollTop": $("#id").scrollTop() + 100});

You no longer need to setTimeout/setInterval to scroll smoothly.

How do I print colored output to the terminal in Python?

Color_Console library is comparatively easier to use. Install this library and the following code would help you.

from Color_Console import *
ctext("This will be printed" , "white" , "blue")
The first argument is the string to be printed, The second argument is the color of 
the text and the last one is the background color.

The latest version of Color_Console allows you to pass a list or dictionary of colors which would change after a specified delay time.

Also, they have good documentation on all of their functions.

Visit https://pypi.org/project/Color-Console/ to know more.

jQuery Ajax POST example with PHP

You can use serialize. Below is an example.

$("#submit_btn").click(function(){
    $('.error_status').html();
        if($("form#frm_message_board").valid())
        {
            $.ajax({
                type: "POST",
                url: "<?php echo site_url('message_board/add');?>",
                data: $('#frm_message_board').serialize(),
                success: function(msg) {
                    var msg = $.parseJSON(msg);
                    if(msg.success=='yes')
                    {
                        return true;
                    }
                    else
                    {
                        alert('Server error');
                        return false;
                    }
                }
            });
        }
        return false;
    });

What is the difference between a JavaBean and a POJO?

POJO: If the class can be executed with underlying JDK,without any other external third party libraries support then its called POJO

JavaBean: If class only contains attributes with accessors(setters and getters) those are called javabeans.Java beans generally will not contain any bussiness logic rather those are used for holding some data in it.

All Javabeans are POJOs but all POJO are not Javabeans

Angular 4 Pipe Filter

The transform method signature changed somewhere in an RC of Angular 2. Try something more like this:

export class FilterPipe implements PipeTransform {
    transform(items: any[], filterBy: string): any {
        return items.filter(item => item.id.indexOf(filterBy) !== -1);
    }
}

And if you want to handle nulls and make the filter case insensitive, you may want to do something more like the one I have here:

export class ProductFilterPipe implements PipeTransform {

    transform(value: IProduct[], filterBy: string): IProduct[] {
        filterBy = filterBy ? filterBy.toLocaleLowerCase() : null;
        return filterBy ? value.filter((product: IProduct) =>
            product.productName.toLocaleLowerCase().indexOf(filterBy) !== -1) : value;
    }
}

And NOTE: Sorting and filtering in pipes is a big issue with performance and they are NOT recommended. See the docs here for more info: https://angular.io/guide/pipes#appendix-no-filterpipe-or-orderbypipe

How to read HDF5 files in Python

you can use Pandas.

import pandas as pd
pd.read_hdf(filename,key)

How to call a button click event from another method

we have 2 form in this project. in main form change

private void button1_Click(object sender, EventArgs e) { // work }

to

public void button1_Click(object sender, EventArgs e) { // work }

and in other form, when we need above function

        private void button2_Click(object sender, EventArgs e)
    {
        main_page() obj = new main_page();
        obj.button2_Click(sender, e);
    }

Converting Stream to String and back...what are we missing?

Try this.

string output1 = Encoding.ASCII.GetString(byteArray, 0, byteArray.Length)

ldap_bind: Invalid Credentials (49)

I don't see an obvious problem with the above.

It's possible your ldap.conf is being overridden, but the command-line options will take precedence, ldapsearch will ignore BINDDN in the main ldap.conf, so the only parameter that could be wrong is the URI. (The order is ETCDIR/ldap.conf then ~/ldaprc or ~/.ldaprc and then ldaprc in the current directory, though there environment variables which can influence this too, see man ldapconf.)

Try an explicit URI:

ldapsearch -x -W -D 'cn=Manager,dc=example,dc=com' -b "" -s base -H ldap://localhost

or prevent defaults with:

LDAPNOINIT=1 ldapsearch -x -W -D 'cn=Manager,dc=example,dc=com' -b "" -s base

If that doesn't work, then some troubleshooting (you'll probably need the full path to the slapd binary for these):

  • make sure your slapd.conf is being used and is correct (as root)

    slapd -T test -f slapd.conf -d 65535

    You may have a left-over or default slapd.d configuration directory which takes preference over your slapd.conf (unless you specify your config explicitly with -f, slapd.conf is officially deprecated in OpenLDAP-2.4). If you don't get several pages of output then your binaries were built without debug support.

  • stop OpenLDAP, then manually start slapd in a separate terminal/console with debug enabled (as root, ^C to quit)

    slapd -h ldap://localhost -d 481

    then retry the search and see if you can spot the problem (there will be a lot of schema noise in the start of the output unfortunately). (Note: running slapd without the -u/-g options can change file ownerships which can cause problems, you should usually use those options, probably -u ldap -g ldap )

  • if debug is enabled, then try also

    ldapsearch -v -d 63 -W -D 'cn=Manager,dc=example,dc=com' -b "" -s base

sql try/catch rollback/commit - preventing erroneous commit after rollback

I used below ms sql script pattern several times successfully which uses Try-Catch,Commit Transaction- Rollback Transaction,Error Tracking.

Your TRY block will be as follows

 BEGIN TRY
 BEGIN TRANSACTION T
 ----
 //your script block
 ----
 COMMIT TRANSACTION T 
 END TRY

Your CATCH block will be as follows

BEGIN CATCH
DECLARE @ErrMsg NVarChar(4000), 
        @ErrNum Int, 
        @ErrSeverity Int, 
        @ErrState Int, 
        @ErrLine Int, 
        @ErrProc NVarChar(200)
 SELECT @ErrNum = Error_Number(), 
       @ErrSeverity = Error_Severity(), 
       @ErrState = Error_State(), 
       @ErrLine = Error_Line(), 
       @ErrProc = IsNull(Error_Procedure(), '-')
 SET @ErrMsg = N'ErrLine: ' + rtrim(@ErrLine) + ', proc: ' + RTRIM(@ErrProc) + ', 
       Message: '+ Error_Message()

Your ROLLBACK script will be part of CATCH block as follows

IF (@@TRANCOUNT) > 0 
BEGIN
PRINT 'ROLLBACK: ' + SUBSTRING(@ErrMsg,1,4000)
ROLLBACK TRANSACTION T
END
ELSE
BEGIN
PRINT SUBSTRING(@ErrMsg,1,4000);   
END

END CATCH

Above different script blocks you need to use as one block. If any error happens in the TRY block it will go the the CATCH block. There it is setting various details about the error number,error severity,error line ..etc. At last all these details will get append to @ErrMsg parameter. Then it will check for the count of transaction (@@TRANCOUNT >0) , ie if anything is there in the transaction for rollback. If it is there then show the error message and ROLLBACK TRANSACTION. Otherwise simply print the error message.

We have kept our COMMIT TRANSACTION T script towards the last line of TRY block in order to make sure that it should commit the transaction(final change in the database) only after all the code in the TRY block has run successfully.

What is Java Servlet?

Java Servlets are server-side Java program modules that procedure and answer customer demands and actualize the servlet interface. It helps in improving Web server usefulness with negligible overhead, upkeep and support.

A servlet goes about as a mediator between the customer and the server. As servlet modules keep running on the server, they can get and react to demands made by the customer. Demand and reaction objects of the servlet offer a helpful method to deal with HTTP asks for and send content information back to the customer.

Since a servlet is coordinated with the Java dialect, it additionally has all the Java highlights, for example, high movability, stage autonomy, security and Java database availability.

What are some reasons for jquery .focus() not working?

I had problems triggering focus on an element (a form input) that was transitioning into the page. I found it was fixable by invoking the focus event from inside a setTimeout with no delay on it. As I understand it (from, eg. this answer), this delays the function until the current execution queue finishes, so in this case it delays the focus event until the transition has completed.

setTimeout(function(){
    $('#goal-input').focus();
});

HTML5 Audio stop function

In IE 11 I used combined variant:

player.currentTime = 0; 
player.pause(); 
player.currentTime = 0;

Only 2 times repeat prevents IE from continuing loading media stream after pause() and flooding a disk by that.

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

You can delete small batches using a while loop, something like this:

DELETE TOP (10000)  LargeTable 
WHERE readTime < dateadd(MONTH,-7,GETDATE())
WHILE @@ROWCOUNT > 0
BEGIN
    DELETE TOP (10000)  LargeTable 
    WHERE readTime < dateadd(MONTH,-7,GETDATE())
END

jQuery remove selected option from this

This should do the trick:

$('#some_select_box').click(function() {
  $('option:selected', this ).remove();
});

Can someone explain how to implement the jQuery File Upload plugin?

I struggled with this plugin for a while on Rails, and then someone gemified it obsoleting all the code I had created.

Although it looks like you're not using this in Rails, however if anyone is using it checkout this gem. The source is here --> jQueryFileUpload Rails.

Update:

In order to satisfy the commenter I've updated my answer. Essentially "use this gem, here is the source code" If it disappears then do it the long way.

Partly JSON unmarshal into a map in Go

Here is an elegant way to do similar thing. But why do partly JSON unmarshal? That doesn't make sense.

  1. Create your structs for the Chat.
  2. Decode json to the Struct.
  3. Now you can access everything in Struct/Object easily.

Look below at the working code. Copy and paste it.

import (
   "bytes"
   "encoding/json" // Encoding and Decoding Package
   "fmt"
 )

var messeging = `{
"say":"Hello",
"sendMsg":{
    "user":"ANisus",
    "msg":"Trying to send a message"
   }
}`

type SendMsg struct {
   User string `json:"user"`
   Msg  string `json:"msg"`
}

 type Chat struct {
   Say     string   `json:"say"`
   SendMsg *SendMsg `json:"sendMsg"`
}

func main() {
  /** Clean way to solve Json Decoding in Go */
  /** Excellent solution */

   var chat Chat
   r := bytes.NewReader([]byte(messeging))
   chatErr := json.NewDecoder(r).Decode(&chat)
   errHandler(chatErr)
   fmt.Println(chat.Say)
   fmt.Println(chat.SendMsg.User)
   fmt.Println(chat.SendMsg.Msg)

}

 func errHandler(err error) {
   if err != nil {
     fmt.Println(err)
     return
   }
 }

Go playground

SQLException : String or binary data would be truncated

Generally it is that you are inserting a value that is greater than the maximum allowed value. Ex, data column can only hold up to 200 characters, but you are inserting 201-character string

Browser Caching of CSS files

That depends on what headers you are sending along with your CSS files. Check your server configuration as you are probably not sending them manually. Do a google search for "http caching" to learn about different caching options you can set. You can force the browser to download a fresh copy of the file everytime it loads it for instance, or you can cache the file for one week...

What is the "Temporary ASP.NET Files" folder for?

The CLR uses it when it is compiling at runtime. Here is a link to MSDN that explains further.

How to write ternary operator condition in jQuery?

Here is a working example in side a function:

_x000D_
_x000D_
function setCurrency(){_x000D_
   var returnCurrent;_x000D_
   $("#RequestCurrencyType").is(":checked") === true ? returnCurrent = 'Dollar': returnCurrent = 'Euro';_x000D_
   _x000D_
   return returnCurrent;_x000D_
}
_x000D_
_x000D_
_x000D_

In your case. Change the selector and the return values

_x000D_
_x000D_
$("#blackbox").css('background-color') === 'pink' ? return "black" : return "pink";
_x000D_
_x000D_
_x000D_

lastly, to know what is the value used by the browser run the following in the console:

_x000D_
_x000D_
$("#blackbox").css('background-color')
_x000D_
_x000D_
_x000D_

and use the "rgb(xxx.xxx.xxx)" value instead of the Hex for the color selection.

How can I tell what edition of SQL Server runs on the machine?

select @@version

Sample Output

Microsoft SQL Server 2008 (SP1) - 10.0.2531.0 (X64) Mar 29 2009 10:11:52 Copyright (c) 1988-2008 Microsoft Corporation Developer Edition (64-bit) on Windows NT 6.1 (Build 7600: )

If you just want to get the edition, you can use:

select serverproperty('Edition')

To use in an automated script, you can get the edition ID, which is an integer:

select serverproperty('EditionID')
  • -1253826760 = Desktop
  • -1592396055 = Express
  • -1534726760 = Standard
  • 1333529388 = Workgroup
  • 1804890536 = Enterprise
  • -323382091 = Personal
  • -2117995310 = Developer
  • 610778273 = Enterprise Evaluation
  • 1044790755 = Windows Embedded SQL
  • 4161255391 = Express with Advanced Services

extract the date part from DateTime in C#

DateTime is a DataType which is used to store both Date and Time. But it provides Properties to get the Date Part.

You can get the Date part from Date Property.

http://msdn.microsoft.com/en-us/library/system.datetime.date.aspx

DateTime date1 = new DateTime(2008, 6, 1, 7, 47, 0);
Console.WriteLine(date1.ToString());

// Get date-only portion of date, without its time.
DateTime dateOnly = date1.Date;
// Display date using short date string.
Console.WriteLine(dateOnly.ToString("d"));
// Display date using 24-hour clock.
Console.WriteLine(dateOnly.ToString("g"));
Console.WriteLine(dateOnly.ToString("MM/dd/yyyy HH:mm"));   
// The example displays the following output to the console:
//       6/1/2008 7:47:00 AM
//       6/1/2008
//       6/1/2008 12:00 AM
//       06/01/2008 00:00

How to print instances of a class using print()?

>>> class Test:
...     def __repr__(self):
...         return "Test()"
...     def __str__(self):
...         return "member of Test"
... 
>>> t = Test()
>>> t
Test()
>>> print(t)
member of Test

The __str__ method is what happens when you print it, and the __repr__ method is what happens when you use the repr() function (or when you look at it with the interactive prompt). If this isn't the most Pythonic method, I apologize, because I'm still learning too - but it works.

If no __str__ method is given, Python will print the result of __repr__ instead. If you define __str__ but not __repr__, Python will use what you see above as the __repr__, but still use __str__ for printing.

What is inf and nan?

inf is infinity - a value that is greater than any other value. -inf is therefore smaller than any other value.

nan stands for Not A Number, and this is not equal to 0.

Although positive and negative infinity can be said to be symmetric about 0, the same can be said for any value n, meaning that the result of adding the two yields nan. This idea is discussed in this math.se question.

Because nan is (literally) not a number, you can't do arithmetic with it, so the result of the second operation is also not a number (nan)

Remove all special characters from a string in R?

Instead of using regex to remove those "crazy" characters, just convert them to ASCII, which will remove accents, but will keep the letters.

astr <- "Ábcdêãçoàúü"
iconv(astr, from = 'UTF-8', to = 'ASCII//TRANSLIT')

which results in

[1] "Abcdeacoauu"

Set auto height and width in CSS/HTML for different screen sizes

This is what do you want? DEMO. Try to shrink the browser's window and you'll see that the elements will be ordered.

What I used? Flexible Box Model or Flexbox.

Just add the follow CSS classes to your container element (in this case div#container):

flex-init-setup and flex-ppal-setup.

Where:

  1. flex-init-setup means flexbox init setup; and
  2. flex-ppal-setup means flexbox principal setup

Here are the CSS rules:

 .flex-init-setup {
     display: -webkit-box;
     display: -moz-box;
     display: -webkit-flex;
     display: -ms-flexbox;
     display: flex;
 }
 .flex-ppal-setup {
     -webkit-flex-flow: column wrap;
     -moz-flex-flow: column wrap;
     flex-flow: column wrap;
     -webkit-justify-content: center;
     -moz-justify-content: center;
     justify-content: center;
 }

Be good, Leonardo

Could not open ServletContext resource

Put the things like /src/main/resources/foo/bar.properties and then reference them as classpath:/foo/bar.properties.

Using a .php file to generate a MySQL dump

MajorLeo's answer point me in the right direction but it didn't worked for me. I've found this site that follows the same approach and did work.

$dir = "path/to/file/";
$filename = "backup" . date("YmdHis") . ".sql.gz";

$db_host = "host";
$db_username = "username";
$db_password = "password";
$db_database = "database";

$cmd = "mysqldump -h {$db_host} -u {$db_username} --password={$db_password} {$db_database} | gzip > {$dir}{$filename}";
exec($cmd);

header("Content-type: application/octet-stream");
header("Content-Disposition: attachment; filename=\"$filename\"");

passthru("cat {$dir}{$filename}");

I hope it helps someone else!

Reading serial data in realtime in Python

You can use inWaiting() to get the amount of bytes available at the input queue.

Then you can use read() to read the bytes, something like that:

While True:
    bytesToRead = ser.inWaiting()
    ser.read(bytesToRead)

Why not to use readline() at this case from Docs:

Read a line which is terminated with end-of-line (eol) character (\n by default) or until timeout.

You are waiting for the timeout at each reading since it waits for eol. the serial input Q remains the same it just a lot of time to get to the "end" of the buffer, To understand it better: you are writing to the input Q like a race car, and reading like an old car :)

Multiple ping script in Python

This script:

import subprocess
import os
with open(os.devnull, "wb") as limbo:
        for n in xrange(1, 10):
                ip="192.168.0.{0}".format(n)
                result=subprocess.Popen(["ping", "-c", "1", "-n", "-W", "2", ip],
                        stdout=limbo, stderr=limbo).wait()
                if result:
                        print ip, "inactive"
                else:
                        print ip, "active"

will produce something like this output:

192.168.0.1 active
192.168.0.2 active
192.168.0.3 inactive
192.168.0.4 inactive
192.168.0.5 inactive
192.168.0.6 inactive
192.168.0.7 active
192.168.0.8 inactive
192.168.0.9 inactive

You can capture the output if you replace limbo with subprocess.PIPE and use communicate() on the Popen object:

p=Popen( ... )
output=p.communicate()
result=p.wait()

This way you get the return value of the command and can capture the text. Following the manual this is the preferred way to operate a subprocess if you need flexibility:

The underlying process creation and management in this module is handled by the Popen class. It offers a lot of flexibility so that developers are able to handle the less common cases not covered by the convenience functions.

How to merge many PDF files into a single one?

There are lots of free tools that can do this.

I use PDFTK (a open source cross-platform command-line tool) for things like that.

Download a file from NodeJS Server using Express

Use res.download()

It transfers the file at path as an “attachment”. For instance:

var express = require('express');
var router = express.Router();

// ...

router.get('/:id/download', function (req, res, next) {
    var filePath = "/my/file/path/..."; // Or format the path using the `id` rest param
    var fileName = "report.pdf"; // The default name the browser will use

    res.download(filePath, fileName);    
});

How can I obtain the element-wise logical NOT of a pandas Series?

To invert a boolean Series, use ~s:

In [7]: s = pd.Series([True, True, False, True])

In [8]: ~s
Out[8]: 
0    False
1    False
2     True
3    False
dtype: bool

Using Python2.7, NumPy 1.8.0, Pandas 0.13.1:

In [119]: s = pd.Series([True, True, False, True]*10000)

In [10]:  %timeit np.invert(s)
10000 loops, best of 3: 91.8 µs per loop

In [11]: %timeit ~s
10000 loops, best of 3: 73.5 µs per loop

In [12]: %timeit (-s)
10000 loops, best of 3: 73.5 µs per loop

As of Pandas 0.13.0, Series are no longer subclasses of numpy.ndarray; they are now subclasses of pd.NDFrame. This might have something to do with why np.invert(s) is no longer as fast as ~s or -s.

Caveat: timeit results may vary depending on many factors including hardware, compiler, OS, Python, NumPy and Pandas versions.

How to use Global Variables in C#?

First examine if you really need a global variable instead using it blatantly without consideration to your software architecture.

Let's assuming it passes the test. Depending on usage, Globals can be hard to debug with race conditions and many other "bad things", it's best to approach them from an angle where you're prepared to handle such bad things. So,

  1. Wrap all such Global variables into a single static class (for manageability).
  2. Have Properties instead of fields(='variables'). This way you have some mechanisms to address any issues with concurrent writes to Globals in the future.

The basic outline for such a class would be:

public class Globals
{
    private static bool _expired;
    public static bool Expired 
    {
        get
        {
            // Reads are usually simple
            return _expired;
        }
        set
        {
            // You can add logic here for race conditions,
            // or other measurements
            _expired = value;
        }
    }
    // Perhaps extend this to have Read-Modify-Write static methods
    // for data integrity during concurrency? Situational.
}

Usage from other classes (within same namespace)

// Read
bool areWeAlive = Globals.Expired;

// Write
// past deadline
Globals.Expired = true;

CSS to set A4 paper size

CSS

body {
  background: rgb(204,204,204); 
}
page[size="A4"] {
  background: white;
  width: 21cm;
  height: 29.7cm;
  display: block;
  margin: 0 auto;
  margin-bottom: 0.5cm;
  box-shadow: 0 0 0.5cm rgba(0,0,0,0.5);
}
@media print {
  body, page[size="A4"] {
    margin: 0;
    box-shadow: 0;
  }
}

HTML

<page size="A4"></page>
<page size="A4"></page>
<page size="A4"></page>

DEMO

How to set javascript variables using MVC4 with Razor

This sets a JavaScript var for me directly from a web.config defined appSetting..

var pv = '@System.Web.Configuration.WebConfigurationManager.AppSettings["pv"]';

Changing the child element's CSS when the parent is hovered

Not sure if there's terrible reasons to do this or not, but it seems to work with me on the latest version of Chrome/Firefox without any visible performance problems with quite a lot of elements on the page.

*:not(:hover)>.parent-hover-show{
    display:none;
}

But this way, all you need is to apply parent-hover-show to an element and the rest is taken care of, and you can keep whatever default display type you want without it always being "block" or making multiple classes for each type.

Why is a primary-foreign key relation required when we can join without it?

You need two columns of the same type, one on each table, to JOIN on. Whether they're primary and foreign keys or not doesn't matter.

Pandas get topmost n records within each group

Sometimes sorting the whole data ahead is very time consuming. We can groupby first and doing topk for each group:

g = df.groupby(['id']).apply(lambda x: x.nlargest(topk,['value'])).reset_index(drop=True)

SQL Server Creating a temp table for this query

IF OBJECT_ID('tempdb..#MyTempTable') IS NOT NULL DROP TABLE #MyTempTable

CREATE TABLE #MyTempTable (SiteName varchar(50), BillingMonth varchar(10), Consumption float)

INSERT INTO #MyTempTable (SiteName, BillingMonth, Consumption)
SELECT  tblMEP_Sites.Name AS SiteName, convert(varchar(10),BillingMonth ,101)
AS BillingMonth, SUM(Consumption) AS Consumption
FROM tblMEP_Projects.......

Convert PDF to image with high resolution

It's actually pretty easy to do with Preview on a mac. All you have to do is open the file in Preview and save-as (or export) a png or jpeg but make sure that you use at least 300 dpi at the bottom of the window to get a high quality image.

How to parse dates in multiple formats using SimpleDateFormat

For the modern answer I am ignoring the requirement to use SimpleDateFormat. While using this class for parsing was a good idea in 2010 when this question was asked, it is now long outdated. The replacement, DateTimeFormatter, came out in 2014. The idea in the following is pretty much the same as in the accepted answer.

private static DateTimeFormatter[] parseFormatters = Stream.of("M/yy", "M/y", "M/d/y", "M-d-y")
        .map(DateTimeFormatter::ofPattern)
        .toArray(DateTimeFormatter[]::new);

public static YearMonth parseYearMonth(String input) {
    for (DateTimeFormatter formatter : parseFormatters) {
        try {
            return YearMonth.parse(input, formatter);
        } catch (DateTimeParseException dtpe) {
            // ignore, try next format
        }
    }
    throw new IllegalArgumentException("Could not parse " + input);
}

This parses each of the input strings from the question into a year-month of 2009-09. It’s important to try the two-digit year first since "M/y" could also parse 9/09, but into 0009-09 instead.

A limitation of the above code is it ignores the day-of-month from the strings that have one, like 9/1/2009. Maybe it’s OK as long as most formats have only month and year. To pick it up, we’d have to try LocalDate.parse() rather then YearMonth.parse() for the formats that include d in the pattern string. Surely it can be done.

Has anyone ever got a remote JMX JConsole to work?

I have a solution for this:

If your Java process is running on Linux behind a firewall and you want to start JConsole / Java VisualVM / Java Mission Control on Windows on your local machine to connect it to the JMX Port of your Java process.

You need access to your linux machine via SSH login. All Communication will be tunneled over the SSH connection.

TIP: This Solution works no matter if there is a firewall or not.

Disadvantage: Everytime you restart your java process, you will need to do all steps from 4 - 9 again.


1. You need the putty-suite for your Windows machine from here:

http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html

At least the putty.exe


2. Define one free Port on your linux machine:

<jmx-remote-port>

Example:

jmx-remote-port = 15666      


3. Add arguments to java process on the linux machine

This must be done exactly like this. If its done like below, it works for linux Machines behind firewalls (It works cause of the -Djava.rmi.server.hostname=localhost argument).

-Dcom.sun.management.jmxremote
-Dcom.sun.management.jmxremote.port=<jmx-remote-port>
-Dcom.sun.management.jmxremote.ssl=false
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.local.only=false
-Djava.rmi.server.hostname=localhost

Example:

java -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=15666 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.local.only=false -Djava.rmi.server.hostname=localhost ch.sushicutta.jmxremote.Main


4. Get Process-Id of your Java Process

ps -ef | grep <java-processname>

result ---> <process-id>

Example:

ps -ef | grep ch.sushicutta.jmxremote.Main

result ---> 24321


5. Find arbitrary Port for RMIServer stubs download

The java process opens a new TCP Port on the linux machine, where the RMI Server-Stubs will be available for download. This port also needs to be available via SSH Tunnel to get a connection to the Java Virtual Machine.

With netstat -lp this port can be found also the lsof -i gives hints what port has been opened form the java process.

NOTE: This port always changes when java process is started.

netstat -lp | grep <process-id>

tcp        0      0 *:<jmx-remote-port>     *:*     LISTEN      24321/java
tcp        0      0 *:<rmi-server-port>     *:*     LISTEN      24321/java


result ---> <rmi-server-port>

Example:

netstat -lp | grep 24321

tcp        0      0 *:15666     *:*     LISTEN      24321/java
tcp        0      0 *:37123     *:*     LISTEN      24321/java


result ---> 37123


6. Enable two SSH-Tunnels from your Windows machine with putty

Source port: <jmx-remote-port>
Destination: localhost:<jmx-remote-port>
[x] Local       
[x] Auto       

Source port: <rmi-server-port>
Destination: localhost:<rmi-server-port>
[x] Local       
[x] Auto

Example:

Source port: 15666
Destination: localhost:15666
[x] Local       
[x] Auto       

Source port: 37123
Destination: localhost:37123
[x] Local       
[x] Auto


Settings to open an SSL tunnel via Putty


7. Login to your Linux machine with Putty with this SSH-Tunnel enabled.

Leave the putty session open.

When you are logged in, Putty will tunnel all TCP-Connections to the linux machine over the SSH port 22.

JMX-Port:

Windows machine: localhost:15666   >>> SSH >>>   linux machine: localhost:15666

RMIServer-Stub-Port:

Windows Machine: localhost:37123   >>> SSH >>>   linux machine: localhost:37123


8. Start JConsole / Java VisualVM / Java Mission Control to connect to your Java Process using the following URL

This works, cause JConsole / Java VisualVM / Java Mission Control thinks you connect to a Port on your local Windows machine. but Putty send all payload to the port 15666 to your linux machine.

On the linux machine first the java process gives answer and send back the RMIServer Port. In this example 37123.

Then JConsole / Java VisualVM / Java Mission Control thinks it connects to localhost:37123 and putty will send the whole payload forward to the linux machine

The java Process answers and the connection is open.

[x] Remote Process:
service:jmx:rmi:///jndi/rmi://localhost:<jndi-remote-port>/jmxrmi

Example:

[x] Remote Process:
service:jmx:rmi:///jndi/rmi://localhost:15666/jmxrmi


Connect via jmx service url


9. ENJOY #8-]

Can't install gems on OS X "El Capitan"

I had to rm -rf ./vendor then run bundle install again.

Is there a better way to iterate over two lists, getting one element from each list for each iteration?

Another way to do this would be to by using map.

>>> a
[1, 2, 3]
>>> b
[4, 5, 6]
>>> for i,j in map(None,a,b):
    ...   print i,j
    ...
1 4
2 5
3 6

One difference in using map compared to zip is, with zip the length of new list is
same as the length of shortest list. For example:

>>> a
[1, 2, 3, 9]
>>> b
[4, 5, 6]
>>> for i,j in zip(a,b):
    ...   print i,j
    ...
1 4
2 5
3 6

Using map on same data:

>>> for i,j in map(None,a,b):
    ...   print i,j
    ...

    1 4
    2 5
    3 6
    9 None

How do I disable text selection with CSS or JavaScript?

Try this CSS code for cross-browser compatibility.

-webkit-user-select: none;
-khtml-user-select: none;
-moz-user-select: none;
-o-user-select: none;
user-select: none;

Reading/writing an INI file

Here is my class, works like a charm :

public static class IniFileManager
{


    [DllImport("kernel32")]
    private static extern long WritePrivateProfileString(string section,
        string key, string val, string filePath);
    [DllImport("kernel32")]
    private static extern int GetPrivateProfileString(string section,
             string key, string def, StringBuilder retVal,
        int size, string filePath);
    [DllImport("kernel32.dll")]
    private static extern int GetPrivateProfileSection(string lpAppName,
             byte[] lpszReturnBuffer, int nSize, string lpFileName);


    /// <summary>
    /// Write Data to the INI File
    /// </summary>
    /// <PARAM name="Section"></PARAM>
    /// Section name
    /// <PARAM name="Key"></PARAM>
    /// Key Name
    /// <PARAM name="Value"></PARAM>
    /// Value Name
    public static void IniWriteValue(string sPath,string Section, string Key, string Value)
    {
        WritePrivateProfileString(Section, Key, Value, sPath);
    }

    /// <summary>
    /// Read Data Value From the Ini File
    /// </summary>
    /// <PARAM name="Section"></PARAM>
    /// <PARAM name="Key"></PARAM>
    /// <PARAM name="Path"></PARAM>
    /// <returns></returns>
    public static string IniReadValue(string sPath,string Section, string Key)
    {
        StringBuilder temp = new StringBuilder(255);
        int i = GetPrivateProfileString(Section, Key, "", temp,
                                        255, sPath);
        return temp.ToString();

    }

}

The use is obviouse since its a static class, just call IniFileManager.IniWriteValue for readsing a section or IniFileManager.IniReadValue for reading a section.

Failed to find Build Tools revision 23.0.1

I faced the same problem and I solved it doing the following:

Go to /home/[USER]/Android/Sdk/tools and execute:

$android list sdk -a

Which will show a list like:

  1. Android SDK Tools, revision 24.0.2
  2. Android SDK Platform-tools, revision 23.0.2
  3. Android SDK Platform-tools, revision 23.0.1

... and many more

Then, execute the command (attention! at your computer the third option may be different):

$android update sdk -a -u -t 3

It will install the 23.0.1 SDK Platform-tools components.

Try to build your project again.

What is a superfast way to read large files line-by-line in VBA?

'you can modify above and read full file in one go and then display each line as shown below

Option Explicit

Public Function QuickRead(FName As String) As Variant
    Dim i As Integer
    Dim res As String
    Dim l As Long
    Dim v As Variant

    i = FreeFile
    l = FileLen(FName)
    res = Space(l)
    Open FName For Binary Access Read As #i
    Get #i, , res
    Close i
    'split the file with vbcrlf
    QuickRead = Split(res, vbCrLf)
End Function

Sub Test()
    ' you can replace file for "c:\writename.txt to any file name you desire
    Dim strFilePathName As String: strFilePathName = "C:\writename.txt"
    Dim strFileLine As String
    Dim v As Variant
    Dim i As Long
    v = QuickRead(strFilePathName)
    For i = 0 To UBound(v)
        MsgBox v(i)
    Next
End Sub

How to change the font size on a matplotlib plot

If you are a control freak like me, you may want to explicitly set all your font sizes:

import matplotlib.pyplot as plt

SMALL_SIZE = 8
MEDIUM_SIZE = 10
BIGGER_SIZE = 12

plt.rc('font', size=SMALL_SIZE)          # controls default text sizes
plt.rc('axes', titlesize=SMALL_SIZE)     # fontsize of the axes title
plt.rc('axes', labelsize=MEDIUM_SIZE)    # fontsize of the x and y labels
plt.rc('xtick', labelsize=SMALL_SIZE)    # fontsize of the tick labels
plt.rc('ytick', labelsize=SMALL_SIZE)    # fontsize of the tick labels
plt.rc('legend', fontsize=SMALL_SIZE)    # legend fontsize
plt.rc('figure', titlesize=BIGGER_SIZE)  # fontsize of the figure title

Note that you can also set the sizes calling the rc method on matplotlib:

import matplotlib

SMALL_SIZE = 8
matplotlib.rc('font', size=SMALL_SIZE)
matplotlib.rc('axes', titlesize=SMALL_SIZE)

# and so on ...

R dplyr: Drop multiple columns

If you have a special character in the column names, either select or select_may not work as expected. This property of dplyr of using ".". To refer to the data set in the question, the following line can be used to solve this problem:

drop.cols <- c('Sepal.Length', 'Sepal.Width')
  iris %>% .[,setdiff(names(.),drop.cols)]

Java Wait for thread to finish

Generally, when you want to wait for a thread to finish, you should call join() on it.

Duplicating a MySQL table, indices, and data

MySQL way:

CREATE TABLE recipes_new LIKE production.recipes;
INSERT recipes_new SELECT * FROM production.recipes;

How do I convert a String to an int in Java?

Kindly use NumberUtils to parse integers from a string.

  • This function could also handle the exception when the given string is too long.
  • We could also give default values.

Here is the example code.

NumberUtils.toInt("00450");
NumberUtils.toInt("45464646545645400000");
NumberUtils.toInt("45464646545645400000", 0); // Where 0 is the default value.

output:
450
0
0

VB.NET - Remove a characters from a String

The string class's Replace method can also be used to remove multiple characters from a string:

Dim newstring As String
newstring = oldstring.Replace(",", "").Replace(";", "")

Case statement with multiple values in each 'when' block

In a case statement, a , is the equivalent of || in an if statement.

case car
   when 'toyota', 'lexus'
      # code
end

Some other things you can do with a Ruby case statement

Declaring a custom android UI element using XML

It seems that Google has updated its developer page and added various trainings there.

One of them deals with the creation of custom views and can be found here

Get the short Git version hash

Branch with short hash and last comment:

git branch -v

  develop      717c2f9 [ahead 42] blabla
* master       2722bbe [ahead 1] bla

TCP: can two different sockets share a port?

A connected socket is assigned to a new (dedicated) port

That's a common intuition, but it's incorrect. A connected socket is not assigned to a new/dedicated port. The only actual constraint that the TCP stack must satisfy is that the tuple of (local_address, local_port, remote_address, remote_port) must be unique for each socket connection. Thus the server can have many TCP sockets using the same local port, as long as each of the sockets on the port is connected to a different remote location.

See the "Socket Pair" paragraph at: http://books.google.com/books?id=ptSC4LpwGA0C&lpg=PA52&dq=socket%20pair%20tuple&pg=PA52#v=onepage&q=socket%20pair%20tuple&f=false

What is the best way to get the count/length/size of an iterator?

iterator object contains the same number of elements what your collection contained.

List<E> a =...;
Iterator<E> i = a.iterator();
int size = a.size();//Because iterators size is equal to list a's size.

But instead of getting the size of iterator and iterating through index 0 to that size, it is better to iterate through the method next() of the iterator.

HTML Upload MAX_FILE_SIZE does not appear to work

To anyone who had been wonderstruck about some files being easily uploaded and some not, it could be a size issue. I'm sharing this as I was stuck with my PHP code not uploading large files and I kept assuming it wasn't uploading any Excel files. So, if you are using PHP and you want to increase the file upload limit, go to the php.ini file and make the following modifications:

  • upload_max_filesize = 2M

to be changed to

  • upload_max_filesize = 10M

  • post_max_size = 10M

or the size required. Then restart the Apache server and the upload will start magically working. Hope this will be of help to someone.

Where does Hive store files in HDFS?

In Hive terminal type:

hive> set hive.metastore.warehouse.dir;

(it will print the path)

Change PictureBox's image to image from my resources?

try the following:

 myPictureBox.Image = global::mynamespace.Properties.Resources.photo1;

and replace namespace with your project namespace

redirect to current page in ASP.Net

Why Server.Transfer? Response.Redirect(Request.RawUrl) would get you what you need.

How to get share counts using graph API

The facebook like button does two things that the API does not do. This might create confusion when you compare the two.

  1. If the URL you use in your like button has a redirect the button will actually show the count of the redirect URL versus the count of the URL you are using.

  2. If the page has a og:url property the like button will show the likes of that url instead of the url in the browser.

Hope this helps someone

Default session timeout for Apache Tomcat applications

Open $CATALINA_BASE/conf/web.xml and find this

<!-- ==================== Default Session Configuration ================= -->
<!-- You can set the default session timeout (in minutes) for all newly   -->
<!-- created sessions by modifying the value below.                       -->

<session-config>
  <session-timeout>30</session-timeout>
</session-config>

all webapps implicitly inherit from this default web descriptor. You can override session-config as well as other settings defined there in your web.xml.

This is actually from my Tomcat 7 (Windows) but I think 5.5 conf is not very different

Execution order of events when pressing PrimeFaces p:commandButton

I just love getting information like BalusC gives here - and he is kind enough to help SO many people with such GOOD information that I regard his words as gospel, but I was not able to use that order of events to solve this same kind of timing issue in my project. Since BalusC put a great general reference here that I even bookmarked, I thought I would donate my solution for some advanced timing issues in the same place since it does solve the original poster's timing issues as well. I hope this code helps someone:

        <p:pickList id="formPickList" 
                    value="#{mediaDetail.availableMedia}" 
                    converter="MediaPicklistConverter" 
                    widgetVar="formsPicklistWidget" 
                    var="mediaFiles" 
                    itemLabel="#{mediaFiles.mediaTitle}" 
                    itemValue="#{mediaFiles}" >
            <f:facet name="sourceCaption">Available Media</f:facet>
            <f:facet name="targetCaption">Chosen Media</f:facet>
        </p:pickList>

        <p:commandButton id="viewStream_btn" 
                         value="Stream chosen media" 
                         icon="fa fa-download"
                         ajax="true"
                         action="#{mediaDetail.prepareStreams}"                                              
                         update=":streamDialogPanel"
                         oncomplete="PF('streamingDialog').show()"
                         styleClass="ui-priority-primary"
                         style="margin-top:5px" >
            <p:ajax process="formPickList"  />
        </p:commandButton>

The dialog is at the top of the XHTML outside this form and it has a form of its own embedded in the dialog along with a datatable which holds additional commands for streaming the media that all needed to be primed and ready to go when the dialog is presented. You can use this same technique to do things like download customized documents that need to be prepared before they are streamed to the user's computer via fileDownload buttons in the dialog box as well.

As I said, this is a more complicated example, but it hits all the high points of your problem and mine. When the command button is clicked, the result is to first insure the backing bean is updated with the results of the pickList, then tell the backing bean to prepare streams for the user based on their selections in the pick list, then update the controls in the dynamic dialog with an update, then show the dialog box ready for the user to start streaming their content.

The trick to it was to use BalusC's order of events for the main commandButton and then to add the <p:ajax process="formPickList" /> bit to ensure it was executed first - because nothing happens correctly unless the pickList updated the backing bean first (something that was not happening for me before I added it). So, yea, that commandButton rocks because you can affect previous, pending and current components as well as the backing beans - but the timing to interrelate all of them is not easy to get a handle on sometimes.

Happy coding!

Reset identity seed after deleting records in SQL Server

DBCC CHECKIDENT (<TableName>, reseed, 0)

This will set the current identity value to 0.

On inserting the next value, the identity value get incremented to 1.

Android Location Providers - GPS or Network Provider?

There are some great answers mentioned here. Another approach you could take would be to use some free SDKs available online like Atooma, tranql and Neura, that can be integrated with your Android application (it takes less than 20 min to integrate). Along with giving you the accurate location of your user, it can also give you good insights about your user’s activities. Also, some of them consume less than 1% of your battery

Alternative to a goto statement in Java

While some commenters and downvoters argue that this isn't goto, the generated bytecode from the below Java statements really suggests that these statements really do express goto semantics.

Specifically, the do {...} while(true); loop in the second example is optimised by Java compilers in order not to evaluate the loop condition.

Jumping forward

label: {
  // do stuff
  if (check) break label;
  // do more stuff
}

In bytecode:

2  iload_1 [check]
3  ifeq 6          // Jumping forward
6  ..

Jumping backward

label: do {
  // do stuff
  if (check) continue label;
  // do more stuff
  break label;
} while(true);

In bytecode:

 2  iload_1 [check]
 3  ifeq 9
 6  goto 2          // Jumping backward
 9  ..

Display JSON as HTML

First take the JSON string and make real objects out of it. Loop though all of the properties of the object, placing the items in an unordered list. Every time you get to a new object, make a new list.

Apache redirect to another port

Just use a Reverse Proxy in your apache configuration (directly):

ProxyPass /foo http://foo.example.com/bar
ProxyPassReverse /foo http://foo.example.com/bar

Look here for apache documentation of how to use the mod

Shell script to delete directories older than n days

This will do it recursively for you:

find /path/to/base/dir/* -type d -ctime +10 -exec rm -rf {} \;

Explanation:

  • find: the unix command for finding files / directories / links etc.
  • /path/to/base/dir: the directory to start your search in.
  • -type d: only find directories
  • -ctime +10: only consider the ones with modification time older than 10 days
  • -exec ... \;: for each such result found, do the following command in ...
  • rm -rf {}: recursively force remove the directory; the {} part is where the find result gets substituted into from the previous part.

Alternatively, use:

find /path/to/base/dir/* -type d -ctime +10 | xargs rm -rf

Which is a bit more efficient, because it amounts to:

rm -rf dir1 dir2 dir3 ...

as opposed to:

rm -rf dir1; rm -rf dir2; rm -rf dir3; ...

as in the -exec method.


With modern versions of find, you can replace the ; with + and it will do the equivalent of the xargs call for you, passing as many files as will fit on each exec system call:

find . -type d -ctime +10 -exec rm -rf {} +

how to fetch data from database in Hibernate

Query query = session.createQuery("from Employee");

Note: from Employee. here Employee is not your table name it's POJO name.

How can you remove all documents from a collection with Mongoose?

.remove() is deprecated. instead we can use deleteMany

DateTime.deleteMany({}, callback).

Getting only Month and Year from SQL DATE

Get Month & Year From Date

DECLARE @lcMonth nvarchar(10)
DECLARE @lcYear nvarchar(10)

SET @lcYear=(SELECT  DATEPART(YEAR,@Date))
SET @lcMonth=(SELECT  DATEPART(MONTH,@Date))

Fixing Sublime Text 2 line endings?

The EditorConfig project (Github link) is another very viable solution. Similar to sftp-config.json and .sublime-project/workspace sort of file, once you set up a .editorconfig file, either in project folder or in a parent folder, every time you save a file within that directory structure the plugin will automatically apply the settings in the dot file and automate a few different things for you. Some of which are saving Unix-style line endings, adding end-of-file newline, removing whitespace, and adjusting your indent tab/space settings.


QUICK EXAMPLE

Install the EditorConfig plugin in Sublime using Package Control; then place a file named .editorconfig in a parent directory (even your home or the root if you like), with the following content:

[*]
end_of_line = lf

That's it. This setting will automatically apply Unix-style line endings whenever you save a file within that directory structure. You can do more cool stuff, ex. trim unwanted trailing white-spaces or add a trailing newline at the end of each file. For more detail, refer to the example file at https://github.com/sindresorhus/editorconfig-sublime, that is:

# editorconfig.org
root = true

[*]
indent_style = tab
end_of_line = lf
charset = utf-8
trim_trailing_whitespace = true
insert_final_newline = true

[*.md]
trim_trailing_whitespace = false

The root = true line means that EditorConfig won't look for other .editorconfig files in the upper levels of the directory structure.

Angular: conditional class with *ngClass

Additionally, you can add with method function:

In HTML

<div [ngClass]="setClasses()">...</div>

In component.ts

// Set Dynamic Classes
  setClasses() {
    let classes = {
      constantClass: true,
      'conditional-class': this.item.id === 1
    }

    return classes;
  }

Downloading MySQL dump from command line

If you are running the MySQL other than default port:

mysqldump.exe -u username -p -P PORT_NO database > backup.sql

error 1265. Data truncated for column when trying to load data from txt file

The reason is that mysql expecting end of the row symbol in the text file after last specified column, and this symbol is char(10) or '\n'. Depends on operation system where text file created or if you created your text file yourself, it can be other combination (Windows uses '\r\n' (chr(13)+chr(10)) as rows separator). Thus, if you use Windows generated text file, add following suffix to your LOAD command: “ LINES TERMINATED BY '\r\n' ”. Otherwise, check how rows are separated in your text file. On default mysql expecting char(10) as rows separator.

Selector on background color of TextView

The problem here is that you cannot define the background color using a color selector, you need a drawable selector. So, the necessary changes would look like this:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:state_pressed="true"
        android:drawable="@drawable/selected_state" />
</selector>

You would also need to move that resource to the drawable directory where it would make more sense since it's not a color selector per se.

Then you would have to create the res/drawable/selected_state.xml file like this:

<?xml version="1.0" encoding="UTF-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" 
    android:shape="rectangle">
    <solid android:color="@color/semitransparent_white" />
</shape>

and finally, you would use it like this:

android:background="@drawable/selector"

Note: the reason why the OP was getting an image resource drawn is probably because he tried to just reference his resource that was still in the color directory but using @drawable so he ended up with an ID collision, selecting the wrong resource.

Hope this can still help someone even if the OP probably has, I hope, solved his problem by now.

How to move a marker in Google Maps API

use panTo(x,y).This will help u

Plain Old CLR Object vs Data Transfer Object

A POCO follows the rules of OOP. It should (but doesn't have to) have state and behavior. POCO comes from POJO, coined by Martin Fowler [anecdote here]. He used the term POJO as a way to make it more sexy to reject the framework heavy EJB implementations. POCO should be used in the same context in .Net. Don't let frameworks dictate your object's design.

A DTO's only purpose is to transfer state, and should have no behavior. See Martin Fowler's explanation of a DTO for an example of the use of this pattern.

Here's the difference: POCO describes an approach to programming (good old fashioned object oriented programming), where DTO is a pattern that is used to "transfer data" using objects.

While you can treat POCOs like DTOs, you run the risk of creating an anemic domain model if you do so. Additionally, there's a mismatch in structure, since DTOs should be designed to transfer data, not to represent the true structure of the business domain. The result of this is that DTOs tend to be more flat than your actual domain.

In a domain of any reasonable complexity, you're almost always better off creating separate domain POCOs and translating them to DTOs. DDD (domain driven design) defines the anti-corruption layer (another link here, but best thing to do is buy the book), which is a good structure that makes the segregation clear.

ImportError: No module named xlsxwriter

I have the same issue. It seems that pip is the problem. Try

pip uninstall xlsxwriter
easy_install xlsxwriter

Share cookie between subdomain and domain

Here is an example using the DOM cookie API (https://developer.mozilla.org/en-US/docs/Web/API/Document/cookie), so we can see for ourselves the behavior.

If we execute the following JavaScript:

document.cookie = "key=value"

It appears to be the same as executing:

document.cookie = "key=value;domain=mydomain.com"

The cookie key becomes available (only) on the domain mydomain.com.


Now, if you execute the following JavaScript on mydomain.com:

document.cookie = "key=value;domain=.mydomain.com"

The cookie key becomes available to mydomain.com as well as subdomain.mydomain.com.


Finally, if you were to try and execute the following on subdomain.mydomain.com:

document.cookie = "key=value;domain=.mydomain.com"

Does the cookie key become available to subdomain.mydomain.com? I was a bit surprised that this is allowed; I had assumed it would be a security violation for a subdomain to be able to set a cookie on a parent domain.

How to run script as another user without password?

try running:

su -c "Your command right here" -s /bin/sh username

This will run the command as username given that you have permissions to sudo as that user.

Why is enum class preferred over plain enum?

Enumerations are used to represent a set of integer values.

The class keyword after the enum specifies that the enumeration is strongly typed and its enumerators are scoped. This way enum classes prevents accidental misuse of constants.

For Example:

enum class Animal{Dog, Cat, Tiger};
enum class Pets{Dog, Parrot};

Here we can not mix Animal and Pets values.

Animal a = Dog;       // Error: which DOG?    
Animal a = Pets::Dog  // Pets::Dog is not an Animal

Count number of lines in a git repository

: | git mktree | git diff --shortstat --stdin

Or:

git ls-tree @ | sed '1i\\' | git mktree --batch | xargs | git diff-tree --shortstat --stdin

Execute action when back bar button of UINavigationController is pressed

For Swift 5, we can check it in view will disappear

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)

    if self.isMovingFromParent {
        delegate?.passValue(clickedImage: selectedImage)
    }
}

Where's the DateTime 'Z' format specifier?

Label1.Text = dt.ToString("dd MMM yyyy | hh:mm | ff | zzz | zz | z");

will output:

07 Mai 2009 | 08:16 | 13 | +02:00 | +02 | +2

I'm in Denmark, my Offset from GMT is +2 hours, witch is correct.

if you need to get the CLIENT Offset, I recommend that you check a little trick that I did. The Page is in a Server in UK where GMT is +00:00 and, as you can see you will get your local GMT Offset.


Regarding you comment, I did:

DateTime dt1 = DateTime.Now;
DateTime dt2 = dt1.ToUniversalTime();

Label1.Text = dt1.ToString("dd MMM yyyy | hh:mm | ff | zzz | zz | z");
Label2.Text = dt2.ToString("dd MMM yyyy | hh:mm | FF | ZZZ | ZZ | Z");

and I get this:

07 Mai 2009 | 08:24 | 14 | +02:00 | +02 | +2
07 Mai 2009 | 06:24 | 14 | ZZZ | ZZ | Z 

I get no Exception, just ... it does nothing with capital Z :(

I'm sorry, but am I missing something?


Reading carefully the MSDN on Custom Date and Time Format Strings

there is no support for uppercase 'Z'.

How can I print out all possible letter combinations a given phone number can represent?

In Java using recursion:

import java.util.LinkedList;
import java.util.List;

public class Main {  
    // Number-to-letter mappings in order from zero to nine
    public static String mappings[][] = {
        {"0"}, {"1"}, {"A", "B", "C"}, {"D", "E", "F"}, {"G", "H", "I"},
        {"J", "K", "L"}, {"M", "N", "O"}, {"P", "Q", "R", "S"}, 
        {"T", "U", "V"}, {"W", "X", "Y", "Z"}
    };

    public static void generateCombosHelper(List<String> combos, 
            String prefix, String remaining) {
        // The current digit we are working with
        int digit = Integer.parseInt(remaining.substring(0, 1));

        if (remaining.length() == 1) {
            // We have reached the last digit in the phone number, so add 
            // all possible prefix-digit combinations to the list
            for (int i = 0; i < mappings[digit].length; i++) {
                combos.add(prefix + mappings[digit][i]);
            }
        } else {
            // Recursively call this method with each possible new 
            // prefix and the remaining part of the phone number.
            for (int i = 0; i < mappings[digit].length; i++) {
                generateCombosHelper(combos, prefix + mappings[digit][i], 
                        remaining.substring(1));
            }
        }
    }

    public static List<String> generateCombos(String phoneNumber) {
        // This will hold the final list of combinations
        List<String> combos = new LinkedList<String>();

        // Call the helper method with an empty prefix and the entire 
        // phone number as the remaining part.
        generateCombosHelper(combos, "", phoneNumber);

        return combos;
    }

    public static void main(String[] args) {
        String phone = "3456789";
        List<String> combos = generateCombos(phone);

        for (String s : combos) {
            System.out.println(s);
        }
    }
}

Undefined symbols for architecture i386

Add the framework required for the method used in the project target in the "Link Binaries With Libraries" list of Build Phases, it will work easily. Like I have imported to my project

QuartzCore.framework

For the bug

Undefined symbols for architecture i386:

How to always show scrollbar

Simple and easy. Add this attribute to the ScrollBar:

android:fadeScrollbars="false"

Or you can do this in :

scrollView.setScrollbarFadingEnabled(false);

Or in :

scrollView.isScrollbarFadingEnabled = false

Image UriSource and Data Binding

WPF has built-in converters for certain types. If you bind the Image's Source property to a string or Uri value, under the hood WPF will use an ImageSourceConverter to convert the value to an ImageSource.

So

<Image Source="{Binding ImageSource}"/>

would work if the ImageSource property was a string representation of a valid URI to an image.

You can of course roll your own Binding converter:

public class ImageConverter : IValueConverter
{
    public object Convert(
        object value, Type targetType, object parameter, CultureInfo culture)
    {
        return new BitmapImage(new Uri(value.ToString()));
    }

    public object ConvertBack(
        object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotSupportedException();
    }
}

and use it like this:

<Image Source="{Binding ImageSource, Converter={StaticResource ImageConverter}}"/>

In STL maps, is it better to use map::insert than []?

One note is that you can also use Boost.Assign:

using namespace std;
using namespace boost::assign; // bring 'map_list_of()' into scope

void something()
{
    map<int,int> my_map = map_list_of(1,2)(2,3)(3,4)(4,5)(5,6);
}

Make flex items take content width, not width of parent container

Use align-items: flex-start on the container, or align-self: flex-start on the flex items.

No need for display: inline-flex.


An initial setting of a flex container is align-items: stretch. This means that flex items will expand to cover the full length of the container along the cross axis.

The align-self property does the same thing as align-items, except that align-self applies to flex items while align-items applies to the flex container.

By default, align-self inherits the value of align-items.

Since your container is flex-direction: column, the cross axis is horizontal, and align-items: stretch is expanding the child element's width as much as it can.

You can override the default with align-items: flex-start on the container (which is inherited by all flex items) or align-self: flex-start on the item (which is confined to the single item).


Learn more about flex alignment along the cross axis here:

Learn more about flex alignment along the main axis here:

What browsers support HTML5 WebSocket API?

Client side

  • Hixie-75:
    • Chrome 4.0 + 5.0
    • Safari 5.0.0
  • HyBi-00/Hixie-76:
  • HyBi-07+:
  • HyBi-10:
    • Chrome 14.0 + 15.0
    • Firefox 7.0 + 8.0 + 9.0 + 10.0 - prefixed: MozWebSocket
    • IE 10 (from Windows 8 developer preview)
  • HyBi-17/RFC 6455
    • Chrome 16
    • Firefox 11
    • Opera 12.10 / Opera Mobile 12.1

Any browser with Flash can support WebSocket using the web-socket-js shim/polyfill.

See caniuse for the current status of WebSockets support in desktop and mobile browsers.

See the test reports from the WS testsuite included in Autobahn WebSockets for feature/protocol conformance tests.


Server side

It depends on which language you use.

In Java/Java EE:

Some other Java implementations:

In C#:

In PHP:

In Python:

In C:

In Node.js:

  • Socket.io : Socket.io also has serverside ports for Python, Java, Google GO, Rack
  • sockjs : sockjs also has serverside ports for Python, Java, Erlang and Lua
  • WebSocket-Node - Pure JavaScript Client & Server implementation of HyBi-10.

Vert.x (also known as Node.x) : A node like polyglot implementation running on a Java 7 JVM and based on Netty with :

  • Support for Ruby(JRuby), Java, Groovy, Javascript(Rhino/Nashorn), Scala, ...
  • True threading. (unlike Node.js)
  • Understands multiple network protocols out of the box including: TCP, SSL, UDP, HTTP, HTTPS, Websockets, SockJS as fallback for WebSockets

Pusher.com is a Websocket cloud service accessible through a REST API.

DotCloud cloud platform supports Websockets, and Java (Jetty Servlet Container), NodeJS, Python, Ruby, PHP and Perl programming languages.

Openshift cloud platform supports websockets, and Java (Jboss, Spring, Tomcat & Vertx), PHP (ZendServer & CodeIgniter), Ruby (ROR), Node.js, Python (Django & Flask) plateforms.

For other language implementations, see the Wikipedia article for more information.

The RFC for Websockets : RFC6455

Linux cmd to search for a class file among jars irrespective of jar path

Just go to the directory which contains jars and insert below command:

find *.jar | xargs grep className.class

Hope this helps!

Resource interpreted as Document but transferred with MIME type application/json warning in Chrome Developer Tools

you can simply use JSON.stringify(options) convert JSON object to string before submit, then warning dismiss and works fine

"Mixed content blocked" when running an HTTP AJAX operation in an HTTPS page

If you are just visiting a webpage that you trust and you want to move forward fast, just:

1- Click the shield icon in the far right of the address bar.

Allow mixed content in Google Chrome

2- In the pop-up window, click "Load anyway" or "Load unsafe script" (depending on your Chrome version).


If you want to set your Chrome browser to ALWAYS(in all webpages) allow mixed content:

1- In an open Chrome browser, press Ctrl+Shift+Q on your keyboard to force close Chrome. Chrome must be fully closed before the next steps.

2- Right-click the Google Chrome desktop icon (or Start Menu link). Select Properties.

3- At the end of the existing information in the Target field, add: " --allow-running-insecure-content" (There is a space before the first dash.)

4- Click OK.

5- Open Chrome and try to launch the content that was blocked earlier. It should work now.

What does the fpermissive flag do?

If you want a real-world use case for this, try compiling a very old version of X Windows-- say, either XFree86 or XOrg from aboout 2004, right around the split-- using a "modern" (cough) version of gcc, such as 4.9.3.

You'll notice the build CFLAGS specify both "-ansi" and "-pedantic". In theory, this means, "blow up if anything even slightly violates the language spec". In practice, the 3.x series of gcc didn't catch very much of that kind of stuff, and building it with 4.9.3 will leave a smoking hole in the ground unless you set CFLAGS and BOOTSTRAPCFLAGS to "-fpermissive".

Using that flag, most of those C files will actually build, leaving you free to move on to the version-dependent wreckage the lexer will generate. =]

Python map object is not subscriptable

In Python 3, map returns an iterable object of type map, and not a subscriptible list, which would allow you to write map[i]. To force a list result, write

payIntList = list(map(int,payList))

However, in many cases, you can write out your code way nicer by not using indices. For example, with list comprehensions:

payIntList = [pi + 1000 for pi in payList]
for pi in payIntList:
    print(pi)

How do I send a POST request with PHP?

Another alternative of the curl-less method above is to use the native stream functions:

  • stream_context_create():

    Creates and returns a stream context with any options supplied in options preset.

  • stream_get_contents():

    Identical to file_get_contents(), except that stream_get_contents() operates on an already open stream resource and returns the remaining contents in a string, up to maxlength bytes and starting at the specified offset.

A POST function with these can simply be like this:

<?php

function post_request($url, array $params) {
  $query_content = http_build_query($params);
  $fp = fopen($url, 'r', FALSE, // do not use_include_path
    stream_context_create([
    'http' => [
      'header'  => [ // header array does not need '\r\n'
        'Content-type: application/x-www-form-urlencoded',
        'Content-Length: ' . strlen($query_content)
      ],
      'method'  => 'POST',
      'content' => $query_content
    ]
  ]));
  if ($fp === FALSE) {
    return json_encode(['error' => 'Failed to get contents...']);
  }
  $result = stream_get_contents($fp); // no maxlength/offset
  fclose($fp);
  return $result;
}

How can I use mySQL replace() to replace strings in multiple records?

This will help you.

UPDATE play_school_data SET title= REPLACE(title, "&#39;", "'") WHERE title = "Elmer&#39;s Parade";

Result:

title = Elmer's Parade

How to remove the Flutter debug banner?

There is also another way for removing the "debug" banner from the flutter app. Now after new release there is no "debugShowCheckedModeBanner: false," code line in main .dart file. So I think these methods are effective:

  1. If you are using VS Code, then install "Dart DevTools" from extensions. After installation, you can easily find "Dart DevTools" text icon at the bottom of the VS Code. When you click on that text icon, a link will be open in google chrome. From that link page, you can easily remove the banner by just tapping on the banner icon as shown in this screenshot.

NOTE:-- Dart DevTools is a dart language debugger extension in VS Code

  1. If Dart DevTools is already installed in your VS Code, then you can directly open the google chrome and open this URL = "127.0.0.1: ZZZZZ/?hide=debugger&port=XXXXX"

NOTE:-- In this link replace "XXXXX" by 5 digit port-id (on which your flutter app is running) which will vary whenever you use "flutter run" command and replace "ZZZZZ" by your global(unchangeable) 5 digit debugger-id

NOTE:-- these dart dev tools are only for "Google Chrome Browser"

How to change the remote repository for a git submodule?

git config --file=.gitmodules -e opens the default editor in which you can update the path

Soft hyphen in HTML (<wbr> vs. &shy;)

Unfortunately, &shy's support is so inconsistent between browsers that it can't really be used.

QuirksMode is right -- there's no good way to use soft hyphens in HTML right now. See what you can do to go without them.

2013 edit: According to QuirksMode, &shy; now works/is supported on all major browsers.

How does the "final" keyword in Java work? (I can still modify an object.)

First of all, the place in your code where you are initializing (i.e. assigning for the first time) foo is here:

foo = new ArrayList();

foo is an object (with type List) so it is a reference type, not a value type (like int). As such, it holds a reference to a memory location (e.g. 0xA7D2A834) where your List elements are stored. Lines like this

foo.add("foo"); // Modification-1

do not change the value of foo (which, again, is just a reference to a memory location). Instead, they just add elements into that referenced memory location. To violate the final keyword, you would have to try to re-assign foo as follows again:

foo = new ArrayList();

That would give you a compilation error.


Now, with that out of the way, think about what happens when you add the static keyword.

When you do NOT have the static keyword, each object that instantiates the class has its own copy of foo. Therefore, the constructor assigns a value to a blank, fresh copy of the foo variable, which is perfectly fine.

However, when you DO have the static keyword, only one foo exists in memory that is associated with the class. If you were to create two or more objects, the constructor would be attempting to re-assign that one foo each time, violating the final keyword.

How do I push a local repo to Bitbucket using SourceTree without creating a repo on bitbucket first?

As this video illustrates, creating a repo online first is the usual way to go.

The SourceTree Release Notes do mention for SourceTree 1.5+:

Support creating new repositories under team / organisation accounts in Bitbucket.

So while there is no "publishing" feature, you could create your online repo from SourceTree.

The blog post "SourceTree for Windows 1.2 is here" (Sept 2013) also mention:

Now you can configure your Bitbucket, Stash and GitHub accounts in SourceTree and instantly see all your repositories on those services. Easily clone them, open the project on the web, and even create new repositories on the remote service without ever leaving SourceTree.
You’ll find it in the menu under View > Show Hosted Repositories, or using the new button at the bottom right of the bookmarks panel.

http://blog.sourcetreeapp.com/files/2013/09/hostedrepowindow.png

Read files from a Folder present in project

string myFile= File.ReadAllLines(Application.StartupPath.ToString() + @"..\..\..\Data\myTxtFile.txt")

How to make a custom LinkedIn share button

LinkedIn revised their site recently, so there are a ton of old links just redirecting to the developer support homepage. Here is an updated link to the relevant page on LinkedIn's support site (as of Feb 16, 2015): https://developer.linkedin.com/docs/share-on-linkedin

How to construct a std::string from a std::vector<char>?

I think you can just do

std::string s( MyVector.begin(), MyVector.end() );

where MyVector is your std::vector.

Remove the last character in a string in T-SQL?

If you want to do this in two steps, rather than the three of REVERSE-STUFF-REVERSE, you can have your list separator be one or two spaces. Then use RTRIM to trim the trailing spaces, and REPLACE to replace the double spaces with ','

select REPLACE(RTRIM('a  b  c  d  '),'  ', ', ')

However, this is not a good idea if your original string can contain internal spaces.

Not sure about performance. Each REVERSE creates a new copy of the string, but STUFF is a third faster than REPLACE.

also see this

submit the form using ajax

It's much easier to just use jQuery, since this is just a task for university and you do not need to save code.

So, your code will look like:

function sendMyComment() {
    $('#addComment').append('<input type="hidden" name="video_id" id="video_id" value="' + $('#video_id').text() + '"/><input type="hidden" name="video_time" id="video_time" value="' + $('#time').text() +'"/>');
    $.ajax({
        type: 'POST',
        url: $('#addComment').attr('action'),
        data: $('form').serialize(), 
        success: function(response) { ... },
    });

}

Convert string to hex-string in C#

In .NET 5.0 and later you can use the Convert.ToHexString() method.

using System;
using System.Text;

string value = "Hello world";

byte[] bytes = Encoding.UTF8.GetBytes(value);

string hexString = Convert.ToHexString(bytes);

Console.WriteLine($"String value: \"{value}\"");
Console.WriteLine($"   Hex value: \"{hexString}\"");

Running the above example code, you would get the following output:

String value: "Hello world"
   Hex value: "48656C6C6F20776F726C64"

How to run the sftp command with a password from Bash script?

Another way would be to use lftp:

lftp sftp://user:password@host  -e "put local-file.name; bye"

The disadvantage of this method is that other users on the computer can read the password from tools like ps and that the password can become part of your shell history.

A more secure alternative which is available since LFTP 4.5.0 is setting the LFTP_PASSWORDenvironment variable and executing lftp with --env-password. Here's a full example:

LFTP_PASSWORD="just_an_example"
lftp --env-password sftp://user@host  -e "put local-file.name; bye"

LFTP also includes a cool mirroring feature (can include delete after confirmed transfer --Remove-source-files):

lftp -e 'mirror -R /local/log/path/ /remote/path/' --env-password -u user sftp.foo.com

Python Function to test ping

It looks like you want the return keyword

def check_ping():
    hostname = "taylor"
    response = os.system("ping -c 1 " + hostname)
    # and then check the response...
    if response == 0:
        pingstatus = "Network Active"
    else:
        pingstatus = "Network Error"

    return pingstatus

You need to capture/'receive' the return value of the function(pingstatus) in a variable with something like:

pingstatus = check_ping()

NOTE: ping -c is for Linux, for Windows use ping -n

Some info on python functions:

http://www.tutorialspoint.com/python/python_functions.htm

http://www.learnpython.org/en/Functions

It's probably worth going through a good introductory tutorial to Python, which will cover all the fundamentals. I recommend investigating Udacity.com and codeacademy.com

How to create websockets server in PHP

I was in the same boat as you recently, and here is what I did:

  1. I used the phpwebsockets code as a reference for how to structure the server-side code. (You seem to already be doing this, and as you noted, the code doesn't actually work for a variety of reasons.)

  2. I used PHP.net to read the details about every socket function used in the phpwebsockets code. By doing this, I was finally able to understand how the whole system works conceptually. This was a pretty big hurdle.

  3. I read the actual WebSocket draft. I had to read this thing a bunch of times before it finally started to sink in. You will likely have to go back to this document again and again throughout the process, as it is the one definitive resource with correct, up-to-date information about the WebSocket API.

  4. I coded the proper handshake procedure based on the instructions in the draft in #3. This wasn't too bad.

  5. I kept getting a bunch of garbled text sent from the clients to the server after the handshake and I couldn't figure out why until I realized that the data is encoded and must be unmasked. The following link helped me a lot here: (original link broken) Archived copy.

    Please note that the code available at this link has a number of problems and won't work properly without further modification.

  6. I then came across the following SO thread, which clearly explains how to properly encode and decode messages being sent back and forth: How can I send and receive WebSocket messages on the server side?

    This link was really helpful. I recommend consulting it while looking at the WebSocket draft. It'll help make more sense out of what the draft is saying.

  7. I was almost done at this point, but had some issues with a WebRTC app I was making using WebSocket, so I ended up asking my own question on SO, which I eventually solved: What is this data at the end of WebRTC candidate info?

  8. At this point, I pretty much had it all working. I just had to add some additional logic for handling the closing of connections, and I was done.

That process took me about two weeks total. The good news is that I understand WebSocket really well now and I was able to make my own client and server scripts from scratch that work great. Hopefully the culmination of all that information will give you enough guidance and information to code your own WebSocket PHP script.

Good luck!


Edit: This edit is a couple of years after my original answer, and while I do still have a working solution, it's not really ready for sharing. Luckily, someone else on GitHub has almost identical code to mine (but much cleaner), so I recommend using the following code for a working PHP WebSocket solution:
https://github.com/ghedipunk/PHP-Websockets/blob/master/websockets.php


Edit #2: While I still enjoy using PHP for a lot of server-side related things, I have to admit that I've really warmed up to Node.js a lot recently, and the main reason is because it's better designed from the ground up to handle WebSocket than PHP (or any other server-side language). As such, I've found recently that it's a lot easier to set up both Apache/PHP and Node.js on your server and use Node.js for running the WebSocket server and Apache/PHP for everything else. And in the case where you're on a shared hosting environment in which you can't install/use Node.js for WebSocket, you can use a free service like Heroku to set up a Node.js WebSocket server and make cross-domain requests to it from your server. Just make sure if you do that to set your WebSocket server up to be able to handle cross-origin requests.

What is a practical, real world example of the Linked List?

Best and straight forward example of doubly linked list is Train!

enter image description here

Here Each coach is connected to its previous and next coach(Except first and last)

In terms of programming consider coach body as data(value) node and connector as reference node.

How can I combine two commits into one commit?

Lazy simple version for forgetfuls like me:

git rebase -i HEAD~3 or however many commits instead of 3.

Turn this

pick YourCommitMessageWhatever
pick YouGetThePoint
pick IdkManItsACommitMessage

into this

pick YourCommitMessageWhatever
s YouGetThePoint
s IdkManItsACommitMessage

and do some action where you hit esc then enter to save the changes. [1]

When the next screen comes up, get rid of those garbage # lines [2] and create a new commit message or something, and do the same escape enter action. [1]

Wowee, you have fewer commits. Or you just broke everything.


[1] - or whatever works with your git configuration. This is just a sequence that's efficient given my setup.

[2] - you'll see some stuff like # this is your n'th commit a few times, with your original commits right below these message. You want to remove these lines, and create a commit message to reflect the intentions of the n commits that you're combining into 1.

Inserting a tab character into text using C#

Hazar is right with his \t. Here's the full list of escape characters for C#:

\' for a single quote.

\" for a double quote.

\\ for a backslash.

\0 for a null character.

\a for an alert character.

\b for a backspace.

\f for a form feed.

\n for a new line.

\r for a carriage return.

\t for a horizontal tab.

\v for a vertical tab.

\uxxxx for a unicode character hex value (e.g. \u0020).

\x is the same as \u, but you don't need leading zeroes (e.g. \x20).

\Uxxxxxxxx for a unicode character hex value (longer form needed for generating surrogates).

Get Base64 encode file-data from Input Form

I've started to think that using the 'iframe' for Ajax style upload might be a much better choice for my situation until HTML5 comes full circle and I don't have to support legacy browsers in my app!

How to Compare a long value is equal to Long value

Since Java 7 you can use java.util.Objects.equals(Object a, Object b):

These utilities include null-safe or null-tolerant methods

Long id1 = null;
Long id2 = 0l;
Objects.equals(id1, id2));

How to know Laravel version and where is it defined?

CASE - 1

Run this command in your project..

php artisan --version  

You will get version of laravel installed in your system like this..

enter image description here

CASE - 2

Also you can check laravel version in the composer.json file in root directory.

enter image description here

Jest spyOn function called

In your test code your are trying to pass App to the spyOn function, but spyOn will only work with objects, not classes. Generally you need to use one of two approaches here:

1) Where the click handler calls a function passed as a prop, e.g.

class App extends Component {

  myClickFunc = () => {
      console.log('clickity clickcty');
      this.props.someCallback();
  }
  render() {
    return (
      <div className="App">
        <div className="App-header">
          <img src={logo} className="App-logo" alt="logo" />
          <h2>Welcome to React</h2>
        </div>
        <p className="App-intro" onClick={this.myClickFunc}>
          To get started, edit <code>src/App.js</code> and save to reload.
        </p>
      </div>
    );
  }
}

You can now pass in a spy function as a prop to the component, and assert that it is called:

describe('my sweet test', () => {
 it('clicks it', () => {
    const spy = jest.fn();
    const app = shallow(<App someCallback={spy} />)
    const p = app.find('.App-intro')
    p.simulate('click')
    expect(spy).toHaveBeenCalled()
 })
})

2) Where the click handler sets some state on the component, e.g.

class App extends Component {
  state = {
      aProperty: 'first'
  }

  myClickFunc = () => {
      console.log('clickity clickcty');
      this.setState({
          aProperty: 'second'
      });
  }
  render() {
    return (
      <div className="App">
        <div className="App-header">
          <img src={logo} className="App-logo" alt="logo" />
          <h2>Welcome to React</h2>
        </div>
        <p className="App-intro" onClick={this.myClickFunc}>
          To get started, edit <code>src/App.js</code> and save to reload.
        </p>
      </div>
    );
  }
}

You can now make assertions about the state of the component, i.e.

describe('my sweet test', () => {
 it('clicks it', () => {
    const app = shallow(<App />)
    const p = app.find('.App-intro')
    p.simulate('click')
    expect(app.state('aProperty')).toEqual('second');
 })
})

What's the best way to do a backwards loop in C/C#/C++?

NOTE: This post ended up being far more detailed and therefore off topic, I apologize.

That being said my peers read it and believe it is valuable 'somewhere'. This thread is not the place. I would appreciate your feedback on where this should go (I am new to the site).


Anyway this is the C# version in .NET 3.5 which is amazing in that it works on any collection type using the defined semantics. This is a default measure (reuse!) not performance or CPU cycle minimization in most common dev scenario although that never seems to be what happens in the real world (premature optimization).

*** Extension method working over any collection type and taking an action delegate expecting a single value of the type, all executed over each item in reverse **

Requres 3.5:

public static void PerformOverReversed<T>(this IEnumerable<T> sequenceToReverse, Action<T> doForEachReversed)
      {
          foreach (var contextItem in sequenceToReverse.Reverse())
              doForEachReversed(contextItem);
      }

Older .NET versions or do you want to understand Linq internals better? Read on.. Or not..

ASSUMPTION: In the .NET type system the Array type inherits from the IEnumerable interface (not the generic IEnumerable only IEnumerable).

This is all you need to iterate from beginning to end, however you want to move in the opposite direction. As IEnumerable works on Array of type 'object' any type is valid,

CRITICAL MEASURE: We assume if you can process any sequence in reverse order that is 'better' then only being able to do it on integers.

Solution a for .NET CLR 2.0-3.0:

Description: We will accept any IEnumerable implementing instance with the mandate that each instance it contains is of the same type. So if we recieve an array the entire array contains instances of type X. If any other instances are of a type !=X an exception is thrown:

A singleton service:

public class ReverserService { private ReverserService() { }

    /// <summary>
    /// Most importantly uses yield command for efficiency
    /// </summary>
    /// <param name="enumerableInstance"></param>
    /// <returns></returns>
    public static IEnumerable ToReveresed(IEnumerable enumerableInstance)
    {
        if (enumerableInstance == null)
        {
            throw new ArgumentNullException("enumerableInstance");
        }

        // First we need to move forwarad and create a temp
        // copy of a type that allows us to move backwards
        // We can use ArrayList for this as the concrete
        // type

        IList reversedEnumerable = new ArrayList();
        IEnumerator tempEnumerator = enumerableInstance.GetEnumerator();

        while (tempEnumerator.MoveNext())
        {
            reversedEnumerable.Add(tempEnumerator.Current);
        }

        // Now we do the standard reverse over this using yield to return
        // the result
        // NOTE: This is an immutable result by design. That is 
        // a design goal for this simple question as well as most other set related 
        // requirements, which is why Linq results are immutable for example
        // In fact this is foundational code to understand Linq

        for (var i = reversedEnumerable.Count - 1; i >= 0; i--)
        {
            yield return reversedEnumerable[i];
        }
    }
}



public static class ExtensionMethods
{

      public static IEnumerable ToReveresed(this IEnumerable enumerableInstance)
      {
          return ReverserService.ToReveresed(enumerableInstance);
      }
 }

[TestFixture] public class Testing123 {

    /// <summary>
    /// .NET 1.1 CLR
    /// </summary>
    [Test]
    public void Tester_fornet_1_dot_1()
    {
        const int initialSize = 1000;

        // Create the baseline data
        int[] myArray = new int[initialSize];

        for (var i = 0; i < initialSize; i++)
        {
            myArray[i] = i + 1;
        }

        IEnumerable _revered = ReverserService.ToReveresed(myArray);

        Assert.IsTrue(TestAndGetResult(_revered).Equals(1000));
    }

    [Test]
    public void tester_why_this_is_good()
    {

        ArrayList names = new ArrayList();
        names.Add("Jim");
        names.Add("Bob");
        names.Add("Eric");
        names.Add("Sam");

        IEnumerable _revered = ReverserService.ToReveresed(names);

        Assert.IsTrue(TestAndGetResult(_revered).Equals("Sam"));


    }

    [Test]
    public void tester_extension_method()
  {

        // Extension Methods No Linq (Linq does this for you as I will show)
        var enumerableOfInt = Enumerable.Range(1, 1000);

        // Use Extension Method - which simply wraps older clr code
        IEnumerable _revered = enumerableOfInt.ToReveresed();

        Assert.IsTrue(TestAndGetResult(_revered).Equals(1000));


    }


    [Test]
    public void tester_linq_3_dot_5_clr()
    {

        // Extension Methods No Linq (Linq does this for you as I will show)
        IEnumerable enumerableOfInt = Enumerable.Range(1, 1000);

        // Reverse is Linq (which is are extension methods off IEnumerable<T>
        // Note you must case IEnumerable (non generic) using OfType or Cast
        IEnumerable _revered = enumerableOfInt.Cast<int>().Reverse();

        Assert.IsTrue(TestAndGetResult(_revered).Equals(1000));


    }



    [Test]
    public void tester_final_and_recommended_colution()
    {

        var enumerableOfInt = Enumerable.Range(1, 1000);
        enumerableOfInt.PerformOverReversed(i => Debug.WriteLine(i));

    }



    private static object TestAndGetResult(IEnumerable enumerableIn)
    {
      //  IEnumerable x = ReverserService.ToReveresed(names);

        Assert.IsTrue(enumerableIn != null);
        IEnumerator _test = enumerableIn.GetEnumerator();

        // Move to first
        Assert.IsTrue(_test.MoveNext());
        return _test.Current;
    }
}

How do I set the background color of Excel cells using VBA?

It doesn't work if you use Function, but works if you Sub. However, you cannot call a sub from a cell using formula.

Karma: Running a single test file from command line

Even though --files is no longer supported, you can use an env variable to provide a list of files:

// karma.conf.js
function getSpecs(specList) {
  if (specList) {
    return specList.split(',')
  } else {
    return ['**/*_spec.js'] // whatever your default glob is
  }
}

module.exports = function(config) {
  config.set({
    //...
    files: ['app.js'].concat(getSpecs(process.env.KARMA_SPECS))
  });
});

Then in CLI:

$ env KARMA_SPECS="spec1.js,spec2.js" karma start karma.conf.js --single-run

How to convert timestamp to datetime in MySQL?

You can use

select from_unixtime(1300464000,"%Y-%m-%d %h %i %s") from table;

For in details description about

  1. from_unixtime()
  2. unix_timestamp()

Set NOW() as Default Value for datetime datatype?

On versions mysql 5.6.5 and newer, you can use precise datetimes and set default values as well. There is a subtle bit though, which is to pass in the precision value to both the datetime and the NOW() function call.

This Example Works:

    ALTER TABLE my_table MODIFY created datetime(6) NOT NULL DEFAULT NOW(6);

This Example Does not Work:

    ALTER TABLE my_table MODIFY created datetime(6) NOT NULL DEFAULT NOW();

intellij idea - Error: java: invalid source release 1.9

intellij-invalid-source

You've to set the JAVA SDK and appropriate language level in the project settings. Click to enlarge.

Python datetime - setting fixed hour and minute after using strptime to get day,month,year

Use datetime.replace:

from datetime import datetime
dt = datetime.strptime('26 Sep 2012', '%d %b %Y')
newdatetime = dt.replace(hour=11, minute=59)

Use dynamic variable names in `dplyr`

I am also adding an answer that augments this a little bit because I came to this entry when searching for an answer, and this had almost what I needed, but I needed a bit more, which I got via @MrFlik 's answer and the R lazyeval vignettes.

I wanted to make a function that could take a dataframe and a vector of column names (as strings) that I want to be converted from a string to a Date object. I couldn't figure out how to make as.Date() take an argument that is a string and convert it to a column, so I did it as shown below.

Below is how I did this via SE mutate (mutate_()) and the .dots argument. Criticisms that make this better are welcome.

library(dplyr)

dat <- data.frame(a="leave alone",
                  dt="2015-08-03 00:00:00",
                  dt2="2015-01-20 00:00:00")

# This function takes a dataframe and list of column names
# that have strings that need to be
# converted to dates in the data frame
convertSelectDates <- function(df, dtnames=character(0)) {
    for (col in dtnames) {
        varval <- sprintf("as.Date(%s)", col)
        df <- df %>% mutate_(.dots= setNames(list(varval), col))
    }
    return(df)
}

dat <- convertSelectDates(dat, c("dt", "dt2"))
dat %>% str

What is the difference between Builder Design pattern and Factory Design pattern?

In my opinion Builder pattern is used when you want to create an object from a bunch of other objects and creation of part needs to be independent of the object you want to create. It helps to hide the creation of part from the client to make builder and client independent. It is used for complex objects creation (objects which may consists of complicated properties)

While factory pattern specifies that you want to create objects of a common family and you want it to be cerated at once. It is used for simpler objects.

Clicking submit button of an HTML form by a Javascript code

You can do :

document.forms["loginForm"].submit()

But this won't call the onclick action of your button, so you will need to call it by hand.

Be aware that you must use the name of your form and not the id to access it.

XSL xsl:template match="/"

It's worth noting, since it's confusing for people new to XML, that the root (or document node) of an XML document is not the top-level element. It's the parent of the top-level element. This is confusing because it doesn't seem like the top-level element can have a parent. Isn't it the top level?

But look at this, a well-formed XML document:

<?xml-stylesheet href="my_transform.xsl" type="text/xsl"?>
<!-- Comments and processing instructions are XML nodes too, remember. -->
<TopLevelElement/>

The root of this document has three children: a processing instruction, a comment, and an element.

So, for example, if you wanted to write a transform that got rid of that comment, but left in any comments appearing anywhere else in the document, you'd add this to the identity transform:

<xsl:template match="/comment()"/>

Even simpler (and more commonly useful), here's an XPath pattern that matches the document's top-level element irrespective of its name: /*.

How to get the last character of a string in a shell?

Every answer so far implies the word "shell" in the question equates to Bash.

This is how one could do that in a standard Bourne shell:

printf $str | tail -c 1

How to access POST form fields

Given some form:

<form action='/somepath' method='post'>
   <input type='text' name='name'></input>
</form>

Using express

app.post('/somepath', function(req, res) {

    console.log(JSON.stringify(req.body));

    console.log('req.body.name', req.body['name']);
});

Output:

{"name":"x","description":"x"}
req.param.name x

IFrame: This content cannot be displayed in a frame

The X-Frame-Options is defined in the Http Header and not in the <head> section of the page you want to use in the iframe.

Accepted values are: DENY, SAMEORIGIN and ALLOW-FROM "url"

Adding a new line/break tag in XML

The solution to this question is:

<?xml version="1.0" encoding="utf-8"?>
<?xml-stylesheet type="text/xsl" href="dummy.xsl"?>
  <item>
     <summary>
        <![CDATA[Tootsie roll tiramisu macaroon wafer carrot cake. <br />      
                 Danish topping sugar plum tart bonbon caramels cake.]]>
     </summary>
  </item>

by adding the <br /> inside the the <![CDATA]]> this allows the line to break, thus creating a new line!

Open web in new tab Selenium + Python

This is a common code adapted from another examples:

from selenium import webdriver
from selenium.webdriver.common.keys import Keys

driver = webdriver.Firefox()
driver.get("http://www.google.com/")

#open tab
# ... take the code from the options below

# Load a page 
driver.get('http://bings.com')
# Make the tests...

# close the tab
driver.quit()

the possible ways were:

  1. Sending <CTRL> + <T> to one element

    #open tab
    driver.find_element_by_tag_name('body').send_keys(Keys.CONTROL + 't')
    
  2. Sending <CTRL> + <T> via Action chains

    ActionChains(driver).key_down(Keys.CONTROL).send_keys('t').key_up(Keys.CONTROL).perform()
    
  3. Execute a javascript snippet

    driver.execute_script('''window.open("http://bings.com","_blank");''')
    

    In order to achieve this you need to ensure that the preferences browser.link.open_newwindow and browser.link.open_newwindow.restriction are properly set. The default values in the last versions are ok, otherwise you supposedly need:

    fp = webdriver.FirefoxProfile()
    fp.set_preference("browser.link.open_newwindow", 3)
    fp.set_preference("browser.link.open_newwindow.restriction", 2)
    
    driver = webdriver.Firefox(browser_profile=fp)
    

    the problem is that those preferences preset to other values and are frozen at least selenium 3.4.0. When you use the profile to set them with the java binding there comes an exception and with the python binding the new values are ignored.

    In Java there is a way to set those preferences without specifying a profile object when talking to geckodriver, but it seem to be not implemented yet in the python binding:

    FirefoxOptions options = new FirefoxOptions().setProfile(fp);
    options.addPreference("browser.link.open_newwindow", 3);
    options.addPreference("browser.link.open_newwindow.restriction", 2);
    FirefoxDriver driver = new FirefoxDriver(options);
    

The third option did stop working for python in selenium 3.4.0.

The first two options also did seem to stop working in selenium 3.4.0. They do depend on sending CTRL key event to an element. At first glance it seem that is a problem of the CTRL key, but it is failing because of the new multiprocess feature of Firefox. It might be that this new architecture impose new ways of doing that, or maybe is a temporary implementation problem. Anyway we can disable it via:

fp = webdriver.FirefoxProfile()
fp.set_preference("browser.tabs.remote.autostart", False)
fp.set_preference("browser.tabs.remote.autostart.1", False)
fp.set_preference("browser.tabs.remote.autostart.2", False)

driver = webdriver.Firefox(browser_profile=fp)

... and then you can use successfully the first way.

XMLHttpRequest (Ajax) Error

The problem is likely to lie with the line:

window.onload = onPageLoad();

By including the brackets you are saying onload should equal the return value of onPageLoad(). For example:

/*Example function*/
function onPageLoad()
{
    return "science";
}
/*Set on load*/
window.onload = onPageLoad()

If you print out the value of window.onload to the console it will be:

science

The solution is remove the brackets:

window.onload = onPageLoad;

So, you're using onPageLoad as a reference to the so-named function.

Finally, in order to get the response value you'll need a readystatechange listener for your XMLHttpRequest object, since it's asynchronous:

xmlDoc = xmlhttp.responseXML;
parser = new DOMParser(); // This code is untested as it doesn't run this far.

Here you add the listener:

xmlHttp.onreadystatechange = function() {
    if(this.readyState == 4) {
        // Do something
    }
}

Jquery to get SelectedText from dropdown

    <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication1.WebForm1" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script src="jquery-3.1.0.js"></script>
    <script>
        $(function () {
            $('#selectnumber').change(function(){
                alert('.val() = ' + $('#selectnumber').val() + '  AND  html() = ' + $('#selectnumber option:selected').html() + '  AND .text() = ' + $('#selectnumber option:selected').text());
            })
        });
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <select id="selectnumber">
            <option value="1">one</option>
            <option value="2">two</option>
            <option value="3">three</option>
            <option value="4">four</option>
        </select>

    </div>
    </form>
</body>
</html>

Click to see Output Screen

Thanks...:)

Initializing ArrayList with some predefined values

I use a generic class that inherit from ArrayList and implement a constructor with a parameter with variable number or arguments :

public class MyArrayList<T> extends ArrayList<T> {
    public MyArrayList(T...items){
        for (T item : items) {
            this.add(item);
        }
    }
}

Example:

MyArrayList<String>myArrayList=new MyArrayList<String>("s1","s2","s2");

Center an element in Bootstrap 4 Navbar

I had a similar problem; the anchor text in my Bootstrap4 navbar wasn't centered. Simply added text-center in the anchor's class.

How to use JavaScript regex over multiple lines?

[.\n] does not work because . has no special meaning inside of [], it just means a literal .. (.|\n) would be a way to specify "any character, including a newline". If you want to match all newlines, you would need to add \r as well to include Windows and classic Mac OS style line endings: (.|[\r\n]).

That turns out to be somewhat cumbersome, as well as slow, (see KrisWebDev's answer for details), so a better approach would be to match all whitespace characters and all non-whitespace characters, with [\s\S], which will match everything, and is faster and simpler.

In general, you shouldn't try to use a regexp to match the actual HTML tags. See, for instance, these questions for more information on why.

Instead, try actually searching the DOM for the tag you need (using jQuery makes this easier, but you can always do document.getElementsByTagName("pre") with the standard DOM), and then search the text content of those results with a regexp if you need to match against the contents.

How do you specify a debugger program in Code::Blocks 12.11?

  1. Go to settings >> Debugger.
  2. Now as you can see in the image below. There's a tree. Common->GDB/CDB Debugger -> Default. enter image description here

  3. Click on executable path (on the right) to find the address to gdb32.exe .

  4. Click gdb32.exe >> OK.

THATS IT!! This worked for me.

How to display items side-by-side without using tables?

The negative margin would help a lot!

The html DOM looks like below:

<div class="main">
  <div class="main_body">Main content</div>
</div>
<div class="left">Left Images or something else</div>

And the CSS:

.main {
  float:left;
  width:100%;
}

.main_body{
  margin-left:210px;
  height:200px;
}
.left{
  float:left;
  width:200px;
  height:200px;
  margin-left:-100%;
}

The main_body will responsive it's with, may it helps you!

Convert unsigned int to signed int C

It seems like you are expecting int and unsigned int to be a 16-bit integer. That's apparently not the case. Most likely, it's a 32-bit integer - which is large enough to avoid the wrap-around that you're expecting.

Note that there is no fully C-compliant way to do this because casting between signed/unsigned for values out of range is implementation-defined. But this will still work in most cases:

unsigned int x = 65529;
int y = (short) x;      //  If short is a 16-bit integer.

or alternatively:

unsigned int x = 65529;
int y = (int16_t) x;    //  This is defined in <stdint.h>

Simple jQuery, PHP and JSONP example?

More Suggestion

JavaScript:

$.ajax({
        url: "http://FullUrl",
        dataType: 'jsonp',
        success: function (data) {

            //Data from the server in the in the variable "data"
            //In the form of an array

        }

});

PHP CallBack:

<?php

$array = array(
     '0' => array('fullName' => 'Meni Samet', 'fullAdress' => 'New York, NY'),
     '1' => array('fullName' => 'Test 2', 'fullAdress' => 'Paris'),
);

if(isset ($_GET['callback']))
{
    header("Content-Type: application/json");

    echo $_GET['callback']."(".json_encode($array).")";

}
?>

Change multiple files

Better yet:

for i in xa*; do
    sed -i 's/asd/dfg/g' $i
done

because nobody knows how many files are there, and it's easy to break command line limits.

Here's what happens when there are too many files:

# grep -c aaa *
-bash: /bin/grep: Argument list too long
# for i in *; do grep -c aaa $i; done
0
... (output skipped)
#

ASP.NET Temporary files cleanup

Just an update on more current OS's (Vista, Win7, etc.) - the temp file path has changed may be different based on several variables. The items below are not definitive, however, they are a few I have encountered:

"temp" environment variable setting - then it would be:

%temp%\Temporary ASP.NET Files

Permissions and what application/process (VS, IIS, IIS Express) is running the .Net compiler. Accessing the C:\WINDOWS\Microsoft.NET\Framework folders requires elevated permissions and if you are not developing under an account with sufficient permissions then this folder might be used:

c:\Users\[youruserid]\AppData\Local\Temp\Temporary ASP.NET Files

There are also cases where the temp folder can be set via config for a machine or site specific using this:

<compilation tempDirectory="d:\MyTempPlace" />

I even have a funky setup at work where we don't run Admin by default, plus the IT guys have login scripts that set %temp% and I get temp files in 3 different locations depending on what is compiling things! And I'm still not certain about how these paths get picked....sigh.

Still, dthrasher is correct, you can just delete these and VS and IIS will just recompile them as needed.

Does not contain a definition for and no extension method accepting a first argument of type could be found

There are two cases in which this error is raised.

  1. You didn't declare the variable which is used
  2. You didn't create the instances of the class

jQuery append() - return appended elements

var newElementsAppended = $(newHtml).appendTo("#myDiv");
newElementsAppended.effects("highlight", {}, 2000);

Convert string to decimal number with 2 decimal places in Java

litersOfPetrol = Float.parseFloat(df.format(litersOfPetrol));

System.out.println("liters of petrol before putting in editor : "+litersOfPetrol);

You print Float here, that has no format at all.

To print formatted float, just use

String formatted = df.format(litersOfPetrol);
System.out.println("liters of petrol before putting in editor : " + formatted);

Using an Alias in a WHERE clause

 SELECT A.identifier
 , A.name
 , TO_NUMBER(DECODE( A.month_no
         , 1, 200803 
         , 2, 200804 
         , 3, 200805 
         , 4, 200806 
         , 5, 200807 
         , 6, 200808 
         , 7, 200809 
         , 8, 200810 
         , 9, 200811 
         , 10, 200812 
         , 11, 200701 
         , 12, 200702
         , NULL)) as MONTH_NO
 , TO_NUMBER(TO_CHAR(B.last_update_date, 'YYYYMM')) as UPD_DATE
FROM table_a A, table_b B
WHERE .identifier = B.identifier
HAVING MONTH_NO > UPD_DATE

EF LINQ include multiple and nested entities

You can also try

db.Courses.Include("Modules.Chapters").Single(c => c.Id == id);

Python causing: IOError: [Errno 28] No space left on device: '../results/32766.html' on disk with lots of space

The ENOSPC ("No space left on device") error will be triggered in any situation in which the data or the metadata associated with an I/O operation can't be written down anywhere because of lack of space. This doesn't always mean disk space – it could mean physical disk space, logical space (e.g. maximum file length), space in a certain data structure or address space. For example you can get it if there isn't space in the directory table (vfat) or there aren't any inodes left. It roughly means “I can't find where to write this down”.

Particularly in Python, this can happen on any write I/O operation. It can happen during f.write, but it can also happen on open, on f.flush and even on f.close. Where it happened provides a vital clue for the reason that it did – if it happened on open there wasn't enough space to write the metadata for the entry, if it happened during f.write, f.flush or f.close there wasn't enough disk space left or you've exceeded the maximum file size.

If the filesystem in the given directory is vfat you'd hit the maximum file limit at about the same time that you did. The limit is supposed to be 2^16 directory entries, but if I recall correctly some other factors can affect it (e.g. some files require more than one entry).

It would be best to avoid creating so many files in a directory. Few filesystems handle so many directory entries with ease. Unless you're certain that your filesystem deals well with many files in a directory, you can consider another strategy (e.g. create more directories).

P.S. Also do not trust the remaining disk space – some file systems reserve some space for root and others miscalculate the free space and give you a number that just isn't true.

Restarting cron after changing crontab file?

Depending on distribution, using "cron reload" might do nothing. To paste a snippet out of init.d/cron (debian squeeze):

reload|force-reload) log_daemon_msg "Reloading configuration files for periodic command scheduler" "cron"
    # cron reloads automatically
    log_end_msg 0
    ;;

Some developer/maintainer relied on it reloading, but doesn't, and in this case there's not a way to force reload. I'm generating my crontab files as part of a deploy, and unless somehow the length of the file changes, the changes are not reloaded.

react-native :app:installDebug FAILED

In my case, I had the app downloaded from PlayStore and I was trying to debug the APK with the same name. I just uninstalled the app and debugged successfully.

How can I count occurrences with groupBy?

List<String> list = new ArrayList<>();

list.add("Hello");
list.add("Hello");
list.add("World");

Map<String, List<String>> collect = list.stream()
                                        .collect(Collectors.groupingBy(o -> o));
collect.entrySet()
       .forEach(e -> System.out.println(e.getKey() + " - " + e.getValue().size()));

Should I use != or <> for not equal in T-SQL?

One alternative would be to use the NULLIF operator other than <> or != which returns NULL if the two arguments are equal NULLIF in Microsoft Docs. So I believe WHERE clause can be modified for <> and != as follows:

NULLIF(arg1, arg2) IS NOT NULL

As I found that, using <> and != doesn't work for date in some cases. Hence using the above expression does the needful.

iterating over and removing from a map

Maybe you can iterate over the map looking for the keys to remove and storing them in a separate collection. Then remove the collection of keys from the map. Modifying the map while iterating is usually frowned upon. This idea may be suspect if the map is very large.

Creating a pandas DataFrame from columns of other DataFrames with similar indexes

What you ask for is the join operation. With the how argument, you can define how unique indices are handled. Here, some article, which looks helpful concerning this point. In the example below, I left out cosmetics (like renaming columns) for simplicity.

Code

import numpy as np
import pandas as pd
df1 = pd.DataFrame(np.random.randn(5,3), index=pd.date_range('01/02/2014',periods=5,freq='D'), columns=['a','b','c'] )
df2 = pd.DataFrame(np.random.randn(8,3), index=pd.date_range('01/01/2014',periods=8,freq='D'), columns=['a','b','c'] )

df3 = df1.join(df2, how='outer', lsuffix='_df1', rsuffix='_df2')
print(df3)

Output

               a_df1     b_df1     c_df1     a_df2     b_df2     c_df2
2014-01-01       NaN       NaN       NaN  0.109898  1.107033 -1.045376
2014-01-02  0.573754  0.169476 -0.580504 -0.664921 -0.364891 -1.215334
2014-01-03 -0.766361 -0.739894 -1.096252  0.962381 -0.860382 -0.703269
2014-01-04  0.083959 -0.123795 -1.405974  1.825832 -0.580343  0.923202
2014-01-05  1.019080 -0.086650  0.126950 -0.021402 -1.686640  0.870779
2014-01-06 -1.036227 -1.103963 -0.821523 -0.943848 -0.905348  0.430739
2014-01-07       NaN       NaN       NaN  0.312005  0.586585  1.531492
2014-01-08       NaN       NaN       NaN -0.077951 -1.189960  0.995123