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Some Of The Best Answers From Latest Asked Questions

Creating layout constraints programmatically

Regarding your second question about properties, you can use self.myView only if you declared it as a property in class. Since myView is a local variable, you can not use it that way. For more details on this, I would recommend you to go through the apple documentation on Declared Properties,

Printing 2D array in matrix format

Here is how to do it in Unity:

(Modified answer from @markmuetz so be sure to upvote his answer)

int[,] rawNodes = new int[,]
{
    { 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0 }
};

private void Start()
{
    int rowLength = rawNodes.GetLength(0);
    int colLength = rawNodes.GetLength(1);
    string arrayString = "";
    for (int i = 0; i < rowLength; i++)
    {
        for (int j = 0; j < colLength; j++)
        {
            arrayString += string.Format("{0} ", rawNodes[i, j]);
        }
        arrayString += System.Environment.NewLine + System.Environment.NewLine;
    }

    Debug.Log(arrayString);
}

ORA-12154: TNS:could not resolve the connect identifier specified (PLSQL Developer)

  • It did not work so i switched to oracle sql developer and it worked with no problems (making connection under 1 minute).
  • This link gave me an idea connect to MS Access so i created a user in oracle sql developer and the tried to connect to it in Toad and it worked.

Or second solution

you can try to connect using Direct not TNS by providing host and port in the connect screen of Toad

Undefined reference to pow( ) in C, despite including math.h

You need to link with the math library:

gcc -o sphere sphere.c -lm

The error you are seeing: error: ld returned 1 exit status is from the linker ld (part of gcc that combines the object files) because it is unable to find where the function pow is defined.

Including math.h brings in the declaration of the various functions and not their definition. The def is present in the math library libm.a. You need to link your program with this library so that the calls to functions like pow() are resolved.

DataColumn Name from DataRow (not DataTable)

You can make it easier in your code (if you're doing this a lot anyway) by using an extension on the DataRow object, like:

static class Extensions
{
    public static string GetColumn(this DataRow Row, int Ordinal)
    {
        return Row.Table.Columns[Ordinal].ColumnName;
    }
}

Then call it using:

string MyColumnName = MyRow.GetColumn(5);

Convert string into integer in bash script - "Leading Zero" number error

In Short: In order to deal with "Leading Zero" numbers (any 0 digit that comes before the first non-zero) in bash - Use bc An arbitrary precision calculator language

Example:

a="000001"
b=$(echo $a | bc)
echo $b

Output: 1

From Bash manual:

"bc is a language that supports arbitrary precision numbers with interactive execution of statements. There are some similarities in the syntax to the C programming lan- guage. A standard math library is available by command line option. If requested, the math library is defined before processing any files. bc starts by processing code from all the files listed on the command line in the order listed. After all files have been processed, bc reads from the standard input. All code is executed as it is read. (If a file contains a command to halt the processor, bc will never read from the standard input.)"

int to string in MySQL

Try it using CONCAT

CONCAT('site.com/path/','%', CAST(t1.id AS CHAR(25)), '%','/more')

What is the functionality of setSoTimeout and how it works?

This example made everything clear for me:
As you can see setSoTimeout prevent the program to hang! It wait for SO_TIMEOUT time! if it does not get any signal it throw exception! It means that time expired!

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketTimeoutException;

public class SocketTest extends Thread {
  private ServerSocket serverSocket;

  public SocketTest() throws IOException {
    serverSocket = new ServerSocket(8008);
    serverSocket.setSoTimeout(10000);
  }

  public void run() {
    while (true) {
      try {
        System.out.println("Waiting for client on port " + serverSocket.getLocalPort() + "...");
        Socket client = serverSocket.accept();

        System.out.println("Just connected to " + client.getRemoteSocketAddress());
        client.close();
      } catch (SocketTimeoutException s) {
        System.out.println("Socket timed out!");
        break;
      } catch (IOException e) {
        e.printStackTrace();
        break;
      }
    }
  }

  public static void main(String[] args) {
    try {
      Thread t = new SocketTest();
      t.start();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}

How to get Device Information in Android

You may want to take a look at those pages : http://developer.android.com/reference/android/os/Build.html and http://developer.android.com/reference/java/lang/System.html (the getProperty() method might do the job).

For instance :

System.getProperty("os.version"); // OS version
android.os.Build.VERSION.SDK      // API Level
android.os.Build.DEVICE           // Device
android.os.Build.MODEL            // Model 
android.os.Build.PRODUCT          // Product

Etc...

Using Composer's Autoload

The autoload config does start below the vendor dir. So you might want change the vendor dir, e.g.

{
    "config": {
        "vendor-dir": "../vendor/"
    },
    "autoload": {
        "psr-0": {"AppName": "src/"}
    }
}

Or isn't this possible in your project?

Export specific rows from a PostgreSQL table as INSERT SQL script

This is an easy and fast way to export a table to a script with pgAdmin manually without extra installations:

  1. Right click on target table and select "Backup".
  2. Select a file path to store the backup. As Format choose "Plain".
  3. Open the tab "Dump Options #2" at the bottom and check "Use Column Inserts".
  4. Click the Backup-button.
  5. If you open the resulting file with a text reader (e.g. notepad++) you get a script to create the whole table. From there you can simply copy the generated INSERT-Statements.

This method also works with the technique of making an export_table as demonstrated in @Clodoaldo Neto's answer.

Click right on target table and choose "Backup"

Choose a destination path and change the format to "Plain"

Open the tab "Dump Options #2" at the bottom and check "Use Column Inserts"

You can copy the INSERT Statements from there.

How to get last month/year in java?

Here's the code snippet.I think it works.

      Calendar cal = Calendar.getInstance();
      SimpleDateFormat simpleMonth=new SimpleDateFormat("MMMM YYYY");
      cal.add(Calendar.MONTH, -1);
      System.out.println(simpleMonth.format(prevcal.getTime()));

Get Folder Size from Windows Command Line

If you have git installed in your computer (getting more and more common) just open MINGW32 and type: du folder

How to assert two list contain the same elements in Python?

As of Python 3.2 unittest.TestCase.assertItemsEqual(doc) has been replaced by unittest.TestCase.assertCountEqual(doc) which does exactly what you are looking for, as you can read from the python standard library documentation. The method is somewhat misleadingly named but it does exactly what you are looking for.

a and b have the same elements in the same number, regardless of their order

Here a simple example which compares two lists having the same elements but in a different order.

  • using assertCountEqual the test will succeed
  • using assertListEqual the test will fail due to the order difference of the two lists

Here a little example script.

import unittest


class TestListElements(unittest.TestCase):
    def setUp(self):
        self.expected = ['foo', 'bar', 'baz']
        self.result = ['baz', 'foo', 'bar']

    def test_count_eq(self):
        """Will succeed"""
        self.assertCountEqual(self.result, self.expected)

    def test_list_eq(self):
        """Will fail"""
        self.assertListEqual(self.result, self.expected)

if __name__ == "__main__":
    unittest.main()

Side Note : Please make sure that the elements in the lists you are comparing are sortable.

What is the difference between a candidate key and a primary key?

A primary key is a column (or columns) in a table that uniquely identifies the rows in that table.

CUSTOMERS


CustomerNo  FirstName   LastName
1   Sally   Thompson
2   Sally   Henderson
3   Harry   Henderson
4   Sandra  Wellington

For example, in the table above, CustomerNo is the primary key.

The values placed in primary key columns must be unique for each row: no duplicates can be tolerated. In addition, nulls are not allowed in primary key columns.

So, having told you that it is possible to use one or more columns as a primary key, how do you decide which columns (and how many) to choose?

Well there are times when it is advisable or essential to use multiple columns. However, if you cannot see an immediate reason to use multiple columns, then use one. This isn't an absolute rule, it is simply advice. However, primary keys made up of single columns are generally easier to maintain and faster in operation. This means that if you query the database, you will usually get the answer back faster if the tables have single column primary keys.

Next question — which column should you pick? The easiest way to choose a column as a primary key (and a method that is reasonably commonly employed) is to get the database itself to automatically allocate a unique number to each row.

In a table of employees, clearly any column like FirstName is a poor choice since you cannot control employee's first names. Often there is only one choice for the primary key, as in the case above. However, if there is more than one, these can be described as 'candidate keys' — the name reflects that they are candidates for the responsible job of primary key.

Passing 'this' to an onclick event

Yeah first method will work on any element called from elsewhere since it will always take the target element irrespective of id.

check this fiddle

http://jsfiddle.net/8cvBM/

Google Play error "Error while retrieving information from server [DF-DFERH-01]"

Nothing above made it work for me. The thing for me is that I was testing a subscription and i forgot SkuType.SUBS, changing it to INAPP for the reserved google test product fixed it.

How to instantiate a javascript class in another js file?

It is saying the value is undefined because it is a constructor function, not a class with a constructor. In order to use it, you would need to use Customer() or customer().

First, you need to load file1.js before file2.js, like slebetman said:

<script defer src="file1.js" type="module"></script>
<script defer src="file2.js" type="module"></script>

Then, you could change your file1.js as follows:

export default class Customer(){
    constructor(){
        this.name="Jhon";
        this.getName=function(){
            return this.name;
        };
    }
}

And the file2.js as follows:

import { Customer } from "./file1";
var customer=new Customer();

Please correct me if I am wrong.

How do I use .woff fonts for my website?

You need to declare @font-face like this in your stylesheet

@font-face {
  font-family: 'Awesome-Font';
  font-style: normal;
  font-weight: 400;
  src: local('Awesome-Font'), local('Awesome-Font-Regular'), url(path/Awesome-Font.woff) format('woff');
}

Now if you want to apply this font to a paragraph simply use it like this..

p {
font-family: 'Awesome-Font', Arial;
}

More Reference

JOptionPane - input dialog box program

One solution is to actually use an integer array instead of separate test strings:

You could loop parse the response from JOptionPane.showInputDialog into the individual elements of the array.

Arrays.sort could be used to sort them to allow you to pick out the 2 highest values.

The average can be easily calculated then by adding these 2 values & dividing by 2.

int[] testScore = new int[3];

for (int i = 0; i < testScore.length; i++) {
   testScore[i] = Integer.parseInt(JOptionPane.showInputDialog("Please input mark for test " + i + ": "));
}

Arrays.sort(testScore);
System.out.println("Average: " + (testScore[1] + testScore[2])/2.0);

Can a for loop increment/decrement by more than one?

Andrew Whitaker's answer is true, but you can use any expression for any part.
Just remember the second (middle) expression should evaluate so it can be compared to a boolean true or false.

When I use a for loop, I think of it as

for (var i = 0; i < 10; ++i) {
    /* expression */
}

as being

var i = 0;
while( i < 10 ) {
    /* expression */
    ++i;
}

HTTP Get with 204 No Content: Is that normal

Your current combination of a POST with an HTTP 204 response is fine.

Using a POST as a universal replacement for a GET is not supported by the RFC, as each has its own specific purpose and semantics.

The purpose of a GET is to retrieve a resource. Therefore, while allowed, an HTTP 204 wouldn't be the best choice since content IS expected in the response. An HTTP 404 Not Found or an HTTP 410 Gone would be better choices if the server was unable to provide the requested resource.

The RFC also specifically calls out an HTTP 204 as an appropriate response for PUT, POST and DELETE, but omits it for GET.

See the RFC for the semantics of GET.

There are other response codes that could also be returned, indicating no content, that would be more appropriate than an HTTP 204.

For example, for a conditional GET you could receive an HTTP 304 Not Modified response which would contain no body content.

Use nginx to serve static files from subdirectories of a given directory

It should work, however http://nginx.org/en/docs/http/ngx_http_core_module.html#alias says:

When location matches the last part of the directive’s value: it is better to use the root directive instead:

which would yield:

server {
  listen        8080;
  server_name   www.mysite.com mysite.com;
  error_log     /home/www-data/logs/nginx_www.error.log;
  error_page    404    /404.html;

  location /public/doc/ {
    autoindex on;
    root  /home/www-data/mysite;
  } 

  location = /404.html {
    root /home/www-data/mysite/static/html;
  }       
}

Is there any standard for JSON API response format?

I will not be as arrogant to claim that this is a standard so I will use the "I prefer" form.

I prefer terse response (when requesting a list of /articles I want a JSON array of articles).

In my designs I use HTTP for status report, a 200 returns just the payload.

400 returns a message of what was wrong with request:

{"message" : "Missing parameter: 'param'"}

Return 404 if the model/controler/URI doesn't exist

If there was error with processing on my side, I return 501 with a message:

{"message" : "Could not connect to data store."}

From what I've seen quite a few REST-ish frameworks tend to be along these lines.

Rationale:

JSON is supposed to be a payload format, it's not a session protocol. The whole idea of verbose session-ish payloads comes from the XML/SOAP world and various misguided choices that created those bloated designs. After we realized all of it was a massive headache, the whole point of REST/JSON was to KISS it, and adhere to HTTP. I don't think that there is anything remotely standard in either JSend and especially not with the more verbose among them. XHR will react to HTTP response, if you use jQuery for your AJAX (like most do) you can use try/catch and done()/fail() callbacks to capture errors. I can't see how encapsulating status reports in JSON is any more useful than that.

Double decimal formatting in Java

You can use any one of the below methods

  1. If you are using java.text.DecimalFormat

    DecimalFormat decimalFormat = NumberFormat.getCurrencyInstance(); 
    decimalFormat.setMinimumFractionDigits(2); 
    System.out.println(decimalFormat.format(4.0));
    

    OR

    DecimalFormat decimalFormat =  new DecimalFormat("#0.00"); 
    System.out.println(decimalFormat.format(4.0)); 
    
  2. If you want to convert it into simple string format

    System.out.println(String.format("%.2f", 4.0)); 
    

All the above code will print 4.00

CSS text-decoration underline color

(for fellow googlers, copied from duplicate question) This answer is outdated since text-decoration-color is now supported by most modern browsers.

You can do this via the following CSS rule as an example:

text-decoration-color:green


If this rule isn't supported by an older browser, you can use the following solution:

Setting your word with a border-bottom:

a:link {
  color: red;
  text-decoration: none;
  border-bottom: 1px solid blue;
}
a:hover {
 border-bottom-color: green;
}

PivotTable to show values, not sum of values

I fear this might turn out to BE the long way round but could depend on how big your data set is – presumably more than four months for example.

Assuming your data is in ColumnA:C and has column labels in Row 1, also that Month is formatted mmm(this last for ease of sorting):

  1. Sort the data by Name then Month
  2. Enter in D2 =IF(AND(A2=A1,C2=C1),D1+1,1) (One way to deal with what is the tricky issue of multiple entries for the same person for the same month).
  3. Create a pivot table from A1:D(last occupied row no.)
  4. Say insert in F1.
  5. Layout as in screenshot.

SO12803305 example

I’m hoping this would be adequate for your needs because pivot table should automatically update (provided range is appropriate) in response to additional data with refresh. If not (you hard taskmaster), continue but beware that the following steps would need to be repeated each time the source data changes.

  1. Copy pivot table and Paste Special/Values to, say, L1.
  2. Delete top row of copied range with shift cells up.
  3. Insert new cell at L1 and shift down.
  4. Key 'Name' into L1.
  5. Filter copied range and for ColumnL, select Row Labels and numeric values.
  6. Delete contents of L2:L(last selected cell)
  7. Delete blank rows in copied range with shift cells up (may best via adding a column that counts all 12 months). Hopefully result should be as highlighted in yellow.

Happy to explain further/try again (I've not really tested this) if does not suit.

EDIT (To avoid second block of steps above and facilitate updating for source data changes)

.0. Before first step 2. add a blank row at the very top and move A2:D2 up.
.2. Adjust cell references accordingly (in D3 =IF(AND(A3=A2,C3=C2),D2+1,1).
.3. Create pivot table from A:D

.6. Overwrite Row Labels with Name.
.7. PivotTable Tools, Design, Report Layout, Show in Tabular Form and sort rows and columns A>Z.
.8. Hide Row1, ColumnG and rows and columns that show (blank).

additional example

Steps .0. and .2. in the edit are not required if the pivot table is in a different sheet from the source data (recommended).

Step .3. in the edit is a change to simplify the consequences of expanding the source data set. However introduces (blank) into pivot table that if to be hidden may need adjustment on refresh. So may be better to adjust source data range each time that changes instead: PivotTable Tools, Options, Change Data Source, Change Data Source, Select a table or range). In which case copy rather than move in .0.

How to List All Redis Databases?

There is no command to do it (like you would do it with MySQL for instance). The number of Redis databases is fixed, and set in the configuration file. By default, you have 16 databases. Each database is identified by a number (not a name).

You can use the following command to know the number of databases:

CONFIG GET databases
1) "databases"
2) "16"

You can use the following command to list the databases for which some keys are defined:

INFO keyspace
# Keyspace
db0:keys=10,expires=0
db1:keys=1,expires=0
db3:keys=1,expires=0

Please note that you are supposed to use the "redis-cli" client to run these commands, not telnet. If you want to use telnet, then you need to run these commands formatted using the Redis protocol.

For instance:

*2
$4
INFO
$8
keyspace

$79
# Keyspace
db0:keys=10,expires=0
db1:keys=1,expires=0
db3:keys=1,expires=0

You can find the description of the Redis protocol here: http://redis.io/topics/protocol

JavaScript onclick redirect

Just do

onclick="SubmitFrm"

The javascript: prefix is only required for link URLs.

Count how many files in directory PHP

The best answer in my opinion:

$num = count(glob("/exact/path/to/files/" . "*"));
echo $num;
  • It doesnt counts . and ..
  • Its a one liner
  • Im proud of it

How to upload a project to Github

Since I wrote this answer, github released a native windows client which makes all the below steps redundant.

You can also use sourcetree to get both git and mercurial setup on Windows.


Here is how you would do it in Windows:

  1. If you don't have git installed, see this article on how to set it up.
  2. Open up a Windows command prompt.
  3. Change into the directory where your source code is located in the command prompt.
  4. First, create a new repository in this directory git init. This will say "Initialized empty git repository in ....git" (... is the path).
  5. Now you need to tell git about your files by adding them to your repository. Do this with git add filename. If you want to add all your files, you can do git add .
  6. Now that you have added your files and made your changes, you need to commit your changes so git can track them. Type git commit -m "adding files". -m lets you add the commit message in line.

So far, the above steps is what you would do even if you were not using github. They are the normal steps to start a git repository. Remember that git is distributed (decentralized), means you don't need to have a "central server" (or even a network connection), to use git.

Now you want to push the changes to your git repository hosted with github. To you this by telling git to add a remote location, and you do that with this command:

git remote add origin https://github.com/yourusername/your-repo-name.git

*Note: your-repo-name should be created in GitHub before you do a git remote add origin ... Once you have done that, git now knows about your remote repository. You can then tell it to push (which is "upload") your commited files:

git push -u origin master

How to watch and compile all TypeScript sources?

you can watch all files like this

tsc *.ts --watch

Box shadow for bottom side only

You have to specify negative spread in the box shadow to remove side shadow

-webkit-box-shadow: 0 10px 10px -10px #000000;
   -moz-box-shadow: 0 10px 10px -10px #000000;
        box-shadow: 0 10px 10px -10px #000000;

Check out http://dabblet.com/gist/9532817 and try changing properties and know how it behaves

JQuery: detect change in input field

Same functionality i recently achieved using below function.

I wanted to enable SAVE button on edit.

  1. Change event is NOT advisable as it will ONLY be fired if after editing, mouse is clicked somewhere else on the page before clicking SAVE button.
  2. Key Press doesnt handle Backspace, Delete and Paste options.
  3. Key Up handles everything including tab, Shift key.

Hence i wrote below function combining keypress, keyup (for backspace, delete) and paste event for text fields.

Hope it helps you.

function checkAnyFormFieldEdited() {
    /*
     * If any field is edited,then only it will enable Save button
     */
    $(':text').keypress(function(e) { // text written
        enableSaveBtn();
    });

    $(':text').keyup(function(e) {
        if (e.keyCode == 8 || e.keyCode == 46) { //backspace and delete key
            enableSaveBtn();
        } else { // rest ignore
            e.preventDefault();
        }
    });
    $(':text').bind('paste', function(e) { // text pasted
        enableSaveBtn();
    });

    $('select').change(function(e) { // select element changed
        enableSaveBtn();
    });

    $(':radio').change(function(e) { // radio changed
        enableSaveBtn();
    });

    $(':password').keypress(function(e) { // password written
        enableSaveBtn();
    });
    $(':password').bind('paste', function(e) { // password pasted
        enableSaveBtn();
    });


}

Command-line Tool to find Java Heap Size and Memory Used (Linux)?

Try this it worked in Ubuntu and RedHat:

java -XX:+PrintFlagsFinal -version | grep -iE 'HeapSize|PermSize|ThreadStackSize'

For Windows:

java -XX:+PrintFlagsFinal -version | findstr /i "HeapSize PermSize ThreadStackSize"

For Mac

java -XX:+PrintFlagsFinal -version | grep -iE 'heapsize|permsize|threadstacksize'

The output of all this commands resembles the output below:

uintx InitialHeapSize                          := 20655360        {product}
uintx MaxHeapSize                              := 331350016       {product}
uintx PermSize                                  = 21757952        {pd product}
uintx MaxPermSize                               = 85983232        {pd product}
intx ThreadStackSize                           = 1024            {pd product}
java version "1.7.0_05"
Java(TM) SE Runtime Environment (build 1.7.0_05-b05)
Java HotSpot(TM) 64-Bit Server VM (build 23.1-b03, mixed mode)

To find the size in MB, divide the value with (1024*1024).

How can I declare optional function parameters in JavaScript?

With ES6: This is now part of the language:

function myFunc(a, b = 0) {
   // function body
}

Please keep in mind that ES6 checks the values against undefined and not against truthy-ness (so only real undefined values get the default value - falsy values like null will not default).


With ES5:

function myFunc(a,b) {
  b = b || 0;

  // b will be set either to b or to 0.
}

This works as long as all values you explicitly pass in are truthy. Values that are not truthy as per MiniGod's comment: null, undefined, 0, false, ''

It's pretty common to see JavaScript libraries to do a bunch of checks on optional inputs before the function actually starts.

Function to convert column number to letter?

This is a function based on @DamienFennelly's answer above. If you give me a thumbs up, give him a thumbs up too! :P

Function outColLetterFromNumber(iCol as Integer) as String
    sAddr = Cells(1, iCol).Address
    aSplit = Split(sAddr, "$")
    outColLetterFromNumber = aSplit(1)
End Function

is there any PHP function for open page in new tab

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

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

Or you can simply use a javascript for onload

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

System.Threading.Timer in C# it seems to be not working. It runs very fast every 3 second

I would just do:

private static Timer timer;
 private static void Main()
 {
   timer = new Timer(_ => OnCallBack(), null, 1000 * 10,Timeout.Infinite); //in 10 seconds
   Console.ReadLine();
 }

  private static void OnCallBack()
  {
    timer.Dispose();
    Thread.Sleep(3000); //doing some long operation
    timer = new Timer(_ => OnCallBack(), null, 1000 * 10,Timeout.Infinite); //in 10 seconds
  }

And ignore the period parameter, since you're attempting to control the periodicy yourself.


Your original code is running as fast as possible, since you keep specifying 0 for the dueTime parameter. From Timer.Change:

If dueTime is zero (0), the callback method is invoked immediately.

Quickest way to compare two generic lists for differences

I think this is a simple and easy way to compare two lists element by element

x=[1,2,3,5,4,8,7,11,12,45,96,25]
y=[2,4,5,6,8,7,88,9,6,55,44,23]

tmp = []


for i in range(len(x)) and range(len(y)):
    if x[i]>y[i]:
        tmp.append(1)
    else:
        tmp.append(0)
print(tmp)

How to configure Git post commit hook

Hope this helps: http://nrecursions.blogspot.in/2014/02/how-to-trigger-jenkins-build-on-git.html

It's just a matter of using curl to trigger a Jenkins job using the git hooks provided by git.
The command

curl http://localhost:8080/job/someJob/build?delay=0sec

can run a Jenkins job, where someJob is the name of the Jenkins job.

Search for the hooks folder in your hidden .git folder. Rename the post-commit.sample file to post-commit. Open it with Notepad, remove the : Nothing line and paste the above command into it.

That's it. Whenever you do a commit, Git will trigger the post-commit commands defined in the file.

How to print strings with line breaks in java

String newline = System.getProperty("line.separator");
System.out.println("First line" + newline);
System.out.println("Second line" + newline);
System.out.println("Third line");

What ports does RabbitMQ use?

To find out what ports rabbitmq uses:

$ epmd -names

Outputs:

epmd: up and running on port 4369 with data:
name rabbit at port 25672

Run these as root:

lsof -i :4369
lsof -i :25672

More about epmd options.

Unable to open debugger port in IntelliJ

This one worked for me-- If the issue still persists (in case you are not using a glassFish server), then close your JIdea and stop the server. This will disable the ports connectivity. Then start your server and JIdea, this will start fresh connectivity with the ports, resolving the issue.

Need to find a max of three numbers in java

It would help if you provided the error you are seeing. Look at http://docs.oracle.com/javase/7/docs/api/java/lang/Math.html and you will see that max only returns the max between two numbers, so likely you code is not even compiling.

Solve all your compilation errors first.

Then your homework will consist of finding the max of three numbers by comparing the first two together, and comparing that max result with the third value. You should have enough to find your answer now.

How to declare a constant in Java

  1. You can use an enum type in Java 5 and onwards for the purpose you have described. It is type safe.
  2. A is an instance variable. (If it has the static modifier, then it becomes a static variable.) Constants just means the value doesn't change.
  3. Instance variables are data members belonging to the object and not the class. Instance variable = Instance field.

If you are talking about the difference between instance variable and class variable, instance variable exist per object created. While class variable has only one copy per class loader regardless of the number of objects created.

Java 5 and up enum type

public enum Color{
 RED("Red"), GREEN("Green");

 private Color(String color){
    this.color = color;
  }

  private String color;

  public String getColor(){
    return this.color;
  }

  public String toString(){
    return this.color;
  }
}

If you wish to change the value of the enum you have created, provide a mutator method.

public enum Color{
 RED("Red"), GREEN("Green");

 private Color(String color){
    this.color = color;
  }

  private String color;

  public String getColor(){
    return this.color;
  }

  public void setColor(String color){
    this.color = color;
  }

  public String toString(){
    return this.color;
  }
}

Example of accessing:

public static void main(String args[]){
  System.out.println(Color.RED.getColor());

  // or

  System.out.println(Color.GREEN);
}

C program to check little vs. big endian

In short, yes.

Suppose we are on a 32-bit machine.

If it is little endian, the x in the memory will be something like:

       higher memory
          ----->
    +----+----+----+----+
    |0x01|0x00|0x00|0x00|
    +----+----+----+----+
    A
    |
   &x

so (char*)(&x) == 1, and *y+48 == '1'.

If it is big endian, it will be:

    +----+----+----+----+
    |0x00|0x00|0x00|0x01|
    +----+----+----+----+
    A
    |
   &x

so this one will be '0'.

remove inner shadow of text input

I'm working on firefox. and I was having the same issue, input type text are auto defined something looks like boxshadow inset, but it's not. the you want to change is border... just setting border:0; and you're done.

How to maintain aspect ratio using HTML IMG tag

Try this:

<img src="Runtime Path to photo" border="1" height="64" width="64" object-fit="cover">

Adding object-fit="cover" will force the image to take up the space without losing the aspect ratio.

How to catch all exceptions in c# using try and catch?

Both ways are correct.

If you need to do something with the Exception object in the catch block then you should use

try {
    // code....
}
catch (Exception ex){}

and then use ex in the catch block.

Anyway, it is not always a good practice to catch the Exception class, it is a better practice to catch a more specific exception - an exception which you expect.

Switch: Multiple values in one case?

you can try this.

switch (Valor)
            {
                case (Valor1 & Valor2):

                    break;               
            }

Read .csv file in C

A complete example which leaves the fields as NULL-terminated strings in the original input buffer and provides access to them via an array of char pointers. The CSV processor has been confirmed to work with fields enclosed in "double quotes", ignoring any delimiter chars within them.

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

// adjust BUFFER_SIZE to suit longest line 
#define BUFFER_SIZE 1024 * 1024
#define NUM_FIELDS 10
#define MAXERRS 5
#define RET_OK 0
#define RET_FAIL 1
#define FALSE 0
#define TRUE 1

// char* array will point to fields
char *pFields[NUM_FIELDS];
// field offsets into pFields array:
#define LP          0
#define IMIE        1
#define NAZWISKo    2
#define ULICA       3
#define NUMER       4
#define KOD         5
#define MIEJSCOw    6
#define TELEFON     7
#define EMAIL       8
#define DATA_UR     9

long loadFile(FILE *pFile, long *errcount);
static int  loadValues(char *line, long lineno);
static char delim;

long loadFile(FILE *pFile, long *errcount){

    char sInputBuf [BUFFER_SIZE];
    long lineno = 0L;

    if(pFile == NULL)
        return RET_FAIL;

    while (!feof(pFile)) {

        // load line into static buffer
        if(fgets(sInputBuf, BUFFER_SIZE-1, pFile)==NULL)
            break;

        // skip first line (headers)
        if(++lineno==1)
            continue;

        // jump over empty lines
        if(strlen(sInputBuf)==0)
            continue;
        // set pFields array pointers to null-terminated string fields in sInputBuf
        if(loadValues(sInputBuf,lineno)==RET_FAIL){
           (*errcount)++;
            if(*errcount > MAXERRS)
                break;
        } else {    
            // On return pFields array pointers point to loaded fields ready for load into DB or whatever
            // Fields can be accessed via pFields, e.g.
            printf("lp=%s, imie=%s, data_ur=%s\n", pFields[LP], pFields[IMIE], pFields[DATA_UR]);
        }
    }
    return lineno;
}


static int  loadValues(char *line, long lineno){
    if(line == NULL)
        return RET_FAIL;

    // chop of last char of input if it is a CR or LF (e.g.Windows file loading in Unix env.)
    // can be removed if sure fgets has removed both CR and LF from end of line
    if(*(line + strlen(line)-1) == '\r' || *(line + strlen(line)-1) == '\n')
        *(line + strlen(line)-1) = '\0';
    if(*(line + strlen(line)-1) == '\r' || *(line + strlen(line)-1 )== '\n')
        *(line + strlen(line)-1) = '\0';

    char *cptr = line;
    int fld = 0;
    int inquote = FALSE;
    char ch;

    pFields[fld]=cptr;
    while((ch=*cptr) != '\0' && fld < NUM_FIELDS){
        if(ch == '"') {
            if(! inquote)
                pFields[fld]=cptr+1;
            else {
                *cptr = '\0';               // zero out " and jump over it
            }
            inquote = ! inquote;
        } else if(ch == delim && ! inquote){
            *cptr = '\0';                   // end of field, null terminate it
            pFields[++fld]=cptr+1;
        }
        cptr++;
    }   
    if(fld > NUM_FIELDS-1){
        fprintf(stderr, "Expected field count (%d) exceeded on line %ld\n", NUM_FIELDS, lineno);
        return RET_FAIL;
    } else if (fld < NUM_FIELDS-1){
        fprintf(stderr, "Expected field count (%d) not reached on line %ld\n", NUM_FIELDS, lineno);
        return RET_FAIL;    
    }
    return RET_OK;
}

int main(int argc, char **argv)
{
   FILE *fp;
   long errcount = 0L;
   long lines = 0L;

   if(argc!=3){
       printf("Usage: %s csvfilepath delimiter\n", basename(argv[0]));
       return (RET_FAIL);
   }   
   if((delim=argv[2][0])=='\0'){
       fprintf(stderr,"delimiter must be specified\n");
       return (RET_FAIL);
   }
   fp = fopen(argv[1] , "r");
   if(fp == NULL) {
      fprintf(stderr,"Error opening file: %d\n",errno);
      return(RET_FAIL);
   }
   lines=loadFile(fp,&errcount);
   fclose(fp);
   printf("Processed %ld lines, encountered %ld error(s)\n", lines, errcount);
   if(errcount>0)
        return(RET_FAIL);
    return(RET_OK); 
}

Read file As String

Reworked the method set originating from -> the accepted answer

@JaredRummler An answer to your comment:

Read file As String

Won't this add an extra new line at the end of the string?

To prevent having a newline added at the end you can use a Boolean value set during the first loop as you will in the code example Boolean firstLine

public static String convertStreamToString(InputStream is) throws IOException {
   // http://www.java2s.com/Code/Java/File-Input-Output/ConvertInputStreamtoString.htm
    BufferedReader reader = new BufferedReader(new InputStreamReader(is));
    StringBuilder sb = new StringBuilder();
    String line = null;
    Boolean firstLine = true;
    while ((line = reader.readLine()) != null) {
        if(firstLine){
            sb.append(line);
            firstLine = false;
        } else {
            sb.append("\n").append(line);
        }
    }
    reader.close();
    return sb.toString();
}

public static String getStringFromFile (String filePath) throws IOException {
    File fl = new File(filePath);
    FileInputStream fin = new FileInputStream(fl);
    String ret = convertStreamToString(fin);
    //Make sure you close all streams.
    fin.close();
    return ret;
}

Saving image to file

You can try with this code

Image.Save("myfile.png", ImageFormat.Png)

Link : http://msdn.microsoft.com/en-us/library/ms142147.aspx

How to Logout of an Application Where I Used OAuth2 To Login With Google?

I hope we can achieve this by storing the token in session while logging in and access the token when he clicked on logout.

    String _accessToken=(String)session.getAttribute("ACCESS_TOKEN");
    if(_accessToken!=null)
    {
        StringBuffer path=httpRequest.getRequestURL();
        reDirectPage="https://www.google.com/accounts/Logout?
        continue=https://appengine.google.com/_ah/logout?
        continue="+path;
    }
    response.sendRedirect(reDirectPage);

What is Cache-Control: private?

RFC 2616, section 14.9.1:

Indicates that all or part of the response message is intended for a single user and MUST NOT be cached by a shared cache...A private (non-shared) cache MAY cache the response.


Browsers could use this information. Of course, the current "user" may mean many things: OS user, a browser user (e.g. Chrome's profiles), etc. It's not specified.

For me, a more concrete example of Cache-Control: private is that proxy servers (which typically have many users) won't cache it. It is meant for the end user, and no one else.


FYI, the RFC makes clear that this does not provide security. It is about showing the correct content, not securing content.

This usage of the word private only controls where the response may be cached, and cannot ensure the privacy of the message content.

Print "hello world" every X seconds

Try doing this:

Timer t = new Timer();
t.schedule(new TimerTask() {
    @Override
    public void run() {
       System.out.println("Hello World");
    }
}, 0, 5000);

This code will run print to console Hello World every 5000 milliseconds (5 seconds). For more info, read https://docs.oracle.com/javase/1.5.0/docs/api/java/util/Timer.html

How to change language of app when user selects language?

Kotlin solution using context extension

fun Context.applyNewLocale(locale: Locale): Context {
    val config = this.resources.configuration
    val sysLocale = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
        config.locales.get(0)
    } else {
        //Legacy
        config.locale
    }
    if (sysLocale.language != locale.language) {
        Locale.setDefault(locale)
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            config.setLocale(locale)
        } else {
            //Legacy
            config.locale = locale
        }
        resources.updateConfiguration(config, resources.displayMetrics)
    }
    return this
}

Usage

override fun attachBaseContext(newBase: Context?) {
    super.attachBaseContext(newBase?.applyNewLocale(Locale("es", "MX")))
}

How eliminate the tab space in the column in SQL Server 2008

Try this code

SELECT REPLACE([Column], char(9), '') From [dbo.Table] 

char(9) is the TAB character

Preventing an image from being draggable or selectable without using JS

I created a div element which has the same size as the image and is positioned on top of the image. Then, the mouse events do not go to the image element.

type object 'datetime.datetime' has no attribute 'datetime'

If you have used:

from datetime import datetime

Then simply write the code as:

date = datetime(int(year), int(month), 1)

But if you have used:

import datetime

then only you can write:

date = datetime.datetime(int(2005), int(5), 1)

ImportError: No module named psycopg2

Try installing

psycopg2-binary

with pip install psycopg2-binary --user

Python dict how to create key or append an element to key?

Use dict.setdefault():

dic.setdefault(key,[]).append(value)

help(dict.setdefault):

    setdefault(...)
        D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D

How to use UIScrollView in Storyboard

Here are the steps that worked for me on iOS 7 and XCode 5.

  1. Drag a ViewController (it comes with UIView "View").

    1.1 Select "View Controller" and select "File Inspector" and uncheck "Auto layout".

  2. Drag a ScrollView (as child of ViewController's UIView "View")
  3. Select ScrollView and open "Identity Inspector".
  4. Enter "contentSize" for keyPath. Select "Size" for Type. And Enter {320, 1000} for value.

    Note: Step 4 is simply saying that the scroller contains some content whose size is 320x1000 units. So setting contentSize will make scroller work.

  5. Select View Controller, Select "Attributes Inspector" then select Freeform from Size.

    Note: step 5 will allow us to change the size of "View" that the view controller comes with.

  6. Select "View" and then select "Size Inspector".

  7. Set Width to 320 and height to 1000.

Note: 5, 6 & 7 is purely for us to see stretched or entire expanded view inside StoryBoard. Note: Make sure to unselect "Auto Layout" on View Controller.

Your View hierarchy should look like: hierarchy

What is a faster alternative to Python's http.server (or SimpleHTTPServer)?

I found python -m http.server unreliable—some responses would take seconds.

Now I use a server called Ran https://github.com/m3ng9i/ran

Ran: a simple static web server written in Go

At least one JAR was scanned for TLDs yet contained no TLDs

(tomcat 7.0.32) I had problems to see debug messages althought was enabling TldLocationsCache row in tomcat/conf/logging.properties file. All I could see was a warning but not what libs were scanned. Changed every loglevel tried everything no luck. Then I went rogue debug mode (=remove one by one, clean install etc..) and finally found a reason.

My webapp had a customized tomcat/webapps/mywebapp/WEB-INF/classes/logging.properties file. I copied TldLocationsCache row to this file, finally I could see jars filenames.

# To see debug messages in TldLocationsCache, uncomment the following line: org.apache.jasper.compiler.TldLocationsCache.level = FINE

how to set "camera position" for 3d plots using python/matplotlib?

What would be handy would be to apply the Camera position to a new plot. So I plot, then move the plot around with the mouse changing the distance. Then try to replicate the view including the distance on another plot. I find that axx.ax.get_axes() gets me an object with the old .azim and .elev.

IN PYTHON...

axx=ax1.get_axes()
azm=axx.azim
ele=axx.elev
dst=axx.dist       # ALWAYS GIVES 10
#dst=ax1.axes.dist # ALWAYS GIVES 10
#dst=ax1.dist      # ALWAYS GIVES 10

Later 3d graph...

ax2.view_init(elev=ele, azim=azm) #Works!
ax2.dist=dst                       # works but always 10 from axx

EDIT 1... OK, Camera position is the wrong way of thinking concerning the .dist value. It rides on top of everything as a kind of hackey scalar multiplier for the whole graph.

This works for the magnification/zoom of the view:

xlm=ax1.get_xlim3d() #These are two tupples
ylm=ax1.get_ylim3d() #we use them in the next
zlm=ax1.get_zlim3d() #graph to reproduce the magnification from mousing
axx=ax1.get_axes()
azm=axx.azim
ele=axx.elev

Later Graph...

ax2.view_init(elev=ele, azim=azm) #Reproduce view
ax2.set_xlim3d(xlm[0],xlm[1])     #Reproduce magnification
ax2.set_ylim3d(ylm[0],ylm[1])     #...
ax2.set_zlim3d(zlm[0],zlm[1])     #...

How do I run a program from command prompt as a different user and as an admin

All of these answers unfortunately miss the point.

There are 2 security context nuances here, and we need them to overlap. - "Run as administrator" - changing your execution level on your local machine - "Run as different user" - selects what user credentials you run the process under.

When UAC is enabled on a workstation, there are processes which refuse to run unless elevated - simply being a member of the local "Administrators" group isn't enough. If your requirement also dictates that you use alternate credentials to those you are signed in with, we need a method to invoke the process both as the alternate credentials AND elevated.

What I found can be used, though a bit of a hassle, is:

  • run a CMD prompt as administrator
  • use the Sysinternals psexec utility as follows:

    psexec \\localworkstation -h -i -u domain\otheruser exetorun.exe

The first elevation is needed to be able to push the psexec service. The -h runs the new "remote" (local) process elevated, and -i lets it interact with the desktop.

Perhaps there are easier ways than this?

OraOLEDB.Oracle provider is not registered on the local machine

If you are getting this in a C# projet, check if you are running in 64-bit or 32-bit mode with the following code:

        if (IntPtr.Size == 4)
        {
            Console.WriteLine("This is 32-Bit!");
        }
        else if (IntPtr.Size == 8)
        {
            Console.WriteLine("This is 64 Bit!");
        }

If you find that you are running in 64-Bit mode, you may want to try switching to 32-Bit (or vice versa). You can follow this guide to force your application to run as 64 or 32 bit (X64 and X86 respectively). You have to make sure that Platform Target in your project properties is not set to Any CPU and that it is explicitley set.

enter image description here

Switching that option from Any CPU to X86 resolved my error and I was able to connect to the Oracle provider.

How to clone object in C++ ? Or Is there another solution?

If your object is not polymorphic (and a stack implementation likely isn't), then as per other answers here, what you want is the copy constructor. Please note that there are differences between copy construction and assignment in C++; if you want both behaviors (and the default versions don't fit your needs), you'll have to implement both functions.

If your object is polymorphic, then slicing can be an issue and you might need to jump through some extra hoops to do proper copying. Sometimes people use as virtual method called clone() as a helper for polymorphic copying.

Finally, note that getting copying and assignment right, if you need to replace the default versions, is actually quite difficult. It is usually better to set up your objects (via RAII) in such a way that the default versions of copy/assign do what you want them to do. I highly recommend you look at Meyer's Effective C++, especially at items 10,11,12.

Read from a gzip file in python

python: read lines from compressed text files

Using gzip.GzipFile:

import gzip

with gzip.open('input.gz','r') as fin:        
    for line in fin:        
        print('got line', line)

How to input a path with a white space?

If the file contains only parameter assignments, you can use the following loop in place of sourcing it:

# Instead of source file.txt
while IFS="=" read name value; do
    declare "$name=$value"
done < file.txt

This saves you having to quote anything in the file, and is also more secure, as you don't risk executing arbitrary code from file.txt.

Bulk Insert Correctly Quoted CSV File in SQL Server

There is another solution for this.

Consider the quotes as part of the fields delimiter, by editing the fmt file.

You can check this out for more information:

http://blogs.msdn.com/b/sqlserverfaq/archive/2010/02/04/how-to-remove-unwanted-quotation-marks-while-importing-a-data-file.aspx

An extract of the link above:

The only way to remove the quotation marks would be to modify the column delimiters specified during the import operation. The only drawback here is that if you inspect the data to be inserted, you will very quickly realize that the column delimiters are different for each column (Delimiters highlighted above).

So to specify different column delimiters for each column, you would need to use a format file if you plan to use Bulk Insert or BCP. If you generate a format file for the above table structure, it would be as follows:

9.0
3
1       SQLCHAR       0       5       "\t"     1     FName              SQL_Latin1_General_CP1_CI_AS
2       SQLCHAR       0       5       "\t"     2     LName              SQL_Latin1_General_CP1_CI_AS
3       SQLCHAR       0       50      "\r\n"   3     Company            SQL_Latin1_General_CP1_CI_AS

Modify the format file to represent the correct column delimiters for each column. The new format file to be used will look like this:

9.0
4
1       SQLCHAR       0       0     "\""      0     FIRST_QUOTE      SQL_Latin1_General_CP1_CI_AS
2       SQLCHAR       0       5     "\",\""   1     FNAME               SQL_Latin1_General_CP1_CI_AS
3       SQLCHAR       0       5     "\",\""   2     LNAME            SQL_Latin1_General_CP1_CI_AS
4       SQLCHAR       0       50    "\"\r\n"  3     COMPANY          SQL_Latin1_General_CP1_CI_AS

twitter bootstrap autocomplete dropdown / combobox with Knockoutjs

Does the basic HTML5 datalist work? It's clean and you don't have to play around with the messy third party code. W3SCHOOL tutorial

The MDN Documentation is very eloquent and features examples.

SQL select statements with multiple tables

Like that:

SELECT p.*, a.street, a.city FROM persons AS p
JOIN address AS a ON p.id = a.person_id
WHERE a.zip = '97299'

Fastest way to tell if two files have the same contents in Unix/Linux?

You can compare by checksum algorithm like sha256

sha256sum oldFile > oldFile.sha256

echo "$(cat oldFile.sha256) newFile" | sha256sum --check

newFile: OK

if the files are distinct the result will be

newFile: FAILED
sha256sum: WARNING: 1 computed checksum did NOT match

IDEA: javac: source release 1.7 requires target release 1.7

I've hit this after just minor upgrade from IntelliJ IDEA 14 to v14.1. For me changing an edit of top/parent pom helped and then clicked re-import Maven (if it is not automatic).

But it maybe just enough to Right Click on module(s)/aggregated/parent module and Maven -> Reimport.

In Java, how to append a string more efficiently?

You should use the StringBuilder class.

StringBuilder stringBuilder = new StringBuilder();

stringBuilder.append("Some text");
stringBuilder.append("Some text");
stringBuilder.append("Some text");

String finalString = stringBuilder.toString();

In addition, please visit:

Spring: Why do we autowire the interface and not the implemented class?

How does spring know which polymorphic type to use.

As long as there is only a single implementation of the interface and that implementation is annotated with @Component with Spring's component scan enabled, Spring framework can find out the (interface, implementation) pair. If component scan is not enabled, then you have to define the bean explicitly in your application-config.xml (or equivalent spring configuration file).

Do I need @Qualifier or @Resource?

Once you have more than one implementation, then you need to qualify each of them and during auto-wiring, you would need to use the @Qualifier annotation to inject the right implementation, along with @Autowired annotation. If you are using @Resource (J2EE semantics), then you should specify the bean name using the name attribute of this annotation.

Why do we autowire the interface and not the implemented class?

Firstly, it is always a good practice to code to interfaces in general. Secondly, in case of spring, you can inject any implementation at runtime. A typical use case is to inject mock implementation during testing stage.

interface IA
{
  public void someFunction();
}


class B implements IA
{
  public void someFunction()
  {
    //busy code block
  }
  public void someBfunc()
  {
     //doing b things
  }
}


class C implements IA
{
  public void someFunction()
  {
    //busy code block
  }
  public void someCfunc()
  {
     //doing C things
  }
}

class MyRunner
{
     @Autowire
     @Qualifier("b") 
     IA worker;

     ....
     worker.someFunction();
}

Your bean configuration should look like this:

<bean id="b" class="B" />
<bean id="c" class="C" />
<bean id="runner" class="MyRunner" />

Alternatively, if you enabled component scan on the package where these are present, then you should qualify each class with @Component as follows:

interface IA
{
  public void someFunction();
}

@Component(value="b")
class B implements IA
{
  public void someFunction()
  {
    //busy code block
  }
  public void someBfunc()
  {
     //doing b things
  }
}


@Component(value="c")
class C implements IA
{
  public void someFunction()
  {
    //busy code block
  }
  public void someCfunc()
  {
     //doing C things
  }
}

@Component    
class MyRunner
{
     @Autowire
     @Qualifier("b") 
     IA worker;

     ....
     worker.someFunction();
}

Then worker in MyRunner will be injected with an instance of type B.

Creating a file only if it doesn't exist in Node.js

As your intuition correctly guessed, the naive solution with a pair of exists / writeFile calls is wrong. Asynchronous code runs in unpredictable ways. And in given case it is

  • Is there a file a.txt? — No.
  • (File a.txt gets created by another program)
  • Write to a.txt if it's possible. — Okay.

But yes, we can do that in a single call. We're working with file system so it's a good idea to read developer manual on fs. And hey, here's an interesting part.

'w' - Open file for writing. The file is created (if it does not exist) or truncated (if it exists).

'wx' - Like 'w' but fails if path exists.

So all we have to do is just add wx to the fs.open call. But hey, we don't like fopen-like IO. Let's read on fs.writeFile a bit more.

fs.readFile(filename[, options], callback)#

filename String

options Object

encoding String | Null default = null

flag String default = 'r'

callback Function

That options.flag looks promising. So we try

fs.writeFile(path, data, { flag: 'wx' }, function (err) {
    if (err) throw err;
    console.log("It's saved!");
});

And it works perfectly for a single write. I guess this code will fail in some more bizarre ways yet if you try to solve your task with it. You have an atomary "check for a_#.jpg existence, and write there if it's empty" operation, but all the other fs state is not locked, and a_1.jpg file may spontaneously disappear while you're already checking a_5.jpg. Most* file systems are no ACID databases, and the fact that you're able to do at least some atomic operations is miraculous. It's very likely that wx code won't work on some platform. So for the sake of your sanity, use database, finally.

Some more info for the suffering

Imagine we're writing something like memoize-fs that caches results of function calls to the file system to save us some network/cpu time. Could we open the file for reading if it exists, and for writing if it doesn't, all in the single call? Let's take a funny look on those flags. After a while of mental exercises we can see that a+ does what we want: if the file doesn't exist, it creates one and opens it both for reading and writing, and if the file exists it does so without clearing the file (as w+ would). But now we cannot use it neither in (smth)File, nor in create(Smth)Stream functions. And that seems like a missing feature.

So feel free to file it as a feature request (or even a bug) to Node.js github, as lack of atomic asynchronous file system API is a drawback of Node. Though don't expect changes any time soon.

Edit. I would like to link to articles by Linus and by Dan Luu on why exactly you don't want to do anything smart with your fs calls, because the claim was left mostly not based on anything.

Issue with adding common code as git submodule: "already exists in the index"

You need to remove your submodule git repository (projectfolder in this case) first for git path.

rm -rf projectfolder

git rm -r projectfolder

and then add submodule

git submodule add <git_submodule_repository> projectfolder

Find all special characters in a column in SQL Server 2008

select count(*) from dbo.tablename where address_line_1 LIKE '%[\'']%' {eSCAPE'\'}

Get unique values from a list in python

By using basic property of Python Dictionary:

inp=[u'nowplaying', u'PBS', u'PBS', u'nowplaying', u'job', u'debate', u'thenandnow']
d={i for i in inp}
print d

Output will be:

set([u'nowplaying', u'job', u'debate', u'PBS', u'thenandnow'])

redistributable offline .NET Framework 3.5 installer for Windows 8

You don't have to copy everything to C:\dotnet35. Usually all the files are already copied to the folder C:\Windows\WinSxS. Then the command becomes (assuming Windows was installed to C:): "Dism.exe /online /enable-feature /featurename:NetFX3 /All /Source:C:\Windows\WinSxS /LimitAccess" If not you can also point the command to the DVD directly. Then the command becomes (assuming DVD is mounted to D:): "Dism.exe /online /enable-feature /featurename:NetFX3 /All /Source:D:\sources\sxs /LimitAccess".

Passing the argument to CMAKE via command prompt

In the CMakeLists.txt file, create a cache variable, as documented here:

SET(FAB "po" CACHE STRING "Some user-specified option")

Source: http://cmake.org/cmake/help/v2.8.8/cmake.html#command:set

Then, either use the GUI (ccmake or cmake-gui) to set the cache variable, or specify the value of the variable on the cmake command line:

cmake -DFAB:STRING=po

Source: http://cmake.org/cmake/help/v2.8.8/cmake.html#opt:-Dvar:typevalue

Modify your cache variable to a boolean if, in fact, your option is boolean.

Should composer.lock be committed to version control?

You then commit the composer.json to your project and everyone else on your team can run composer install to install your project dependencies.

The point of the lock file is to record the exact versions that are installed so they can be re-installed. This means that if you have a version spec of 1.* and your co-worker runs composer update which installs 1.2.4, and then commits the composer.lock file, when you composer install, you will also get 1.2.4, even if 1.3.0 has been released. This ensures everybody working on the project has the same exact version.

This means that if anything has been committed since the last time a composer install was done, then, without a lock file, you will get new third-party code being pulled down.

Again, this is a problem if you’re concerned about your code breaking. And it’s one of the reasons why it’s important to think about Composer as being centered around the composer.lock file.

Source: Composer: It’s All About the Lock File.


Commit your application's composer.lock (along with composer.json) into version control. This is important because the install command checks if a lock file is present, and if it is, it downloads the versions specified there (regardless of what composer.json says). This means that anyone who sets up the project will download the exact same version of the dependencies. Your CI server, production machines, other developers in your team, everything and everyone runs on the same dependencies, which mitigates the potential for bugs affecting only some parts of the deployments. Even if you develop alone, in six months when reinstalling the project you can feel confident the dependencies installed are still working even if your dependencies released many new versions since then.

Source: Composer - Basic Usage.

Can I pass variable to select statement as column name in SQL Server

You can't use variable names to bind columns or other system objects, you need dynamic sql

DECLARE @value varchar(10)  
SET @value = 'intStep'  
DECLARE @sqlText nvarchar(1000); 

SET @sqlText = N'SELECT ' + @value + ' FROM dbo.tblBatchDetail'
Exec (@sqlText)

appending list but error 'NoneType' object has no attribute 'append'

I think what you want is this:

last_list=[]
if p.last_name != None and p.last_name != "":
    last_list.append(p.last_name)
print last_list

Your current if statement:

if p.last_name == None or p.last_name == "":
    pass

Effectively never does anything. If p.last_name is none or the empty string, it does nothing inside the loop. If p.last_name is something else, the body of the if statement is skipped.

Also, it looks like your statement pan_list.append(p.last) is a typo, because I see neither pan_list nor p.last getting used anywhere else in the code you have posted.

How to check certificate name and alias in keystore files?

This will list all certificates:

keytool -list -keystore "$JAVA_HOME/jre/lib/security/cacerts"

Spring cannot find bean xml configuration file when it does exist

In Spring all source files are inside src/main/java. Similarly, the resources are generally kept inside src/main/resources. So keep your spring configuration file inside resources folder.

Make sure you have the ClassPath entry for your files inside src/main/resources as well.

In .classpath check for the following 2 lines. If they are missing add them.

<classpathentry path="src/main/java" kind="src"/>
<classpathentry path="src/main/resources" kind="src" />

So, if you have everything in place the below code should work.

ApplicationContext ctx = new ClassPathXmlApplicationContext("Spring-Module.xml");

Passing multiple variables in @RequestBody to a Spring MVC controller using Ajax

The easy solution is to create a payload class that has the str1 and the str2 as attributes:

@Getter
@Setter
public class ObjHolder{

String str1;
String str2;

}

And after you can pass

@RequestMapping(value = "/Test", method = RequestMethod.POST)
@ResponseBody
public boolean getTest(@RequestBody ObjHolder Str) {}

and the body of your request is:

{
    "str1": "test one",
    "str2": "two test"
}

How to set the height of an input (text) field in CSS?

You use this style code

.heighttext{
 float:right;
 height:30px;
 width:70px;
 }

403 - Forbidden: Access is denied. You do not have permission to view this directory or page using the credentials that you supplied

I had the same problem. It turned out that I didn't specify a default page and I didn't have any page that is named after the default page convention (default.html, defult.aspx etc). As a result, ASP.NET doesn't allow the user to browse the directory (not a problem in Visual Studio built-in web server that allows you to view the directory) and shows the error message. To fix it, I added one default page in Web.Config and it worked.

<system.webServer>
    <defaultDocument>
        <files>
            <add value="myDefault.aspx"/>
        </files>
    </defaultDocument>
</system.webServer>

correct quoting for cmd.exe for multiple arguments

Note the "" at the beginning and at the end!

Run a program and pass a Long Filename

cmd /c write.exe "c:\sample documents\sample.txt"

Spaces in Program Path

cmd /c ""c:\Program Files\Microsoft Office\Office\Winword.exe""

Spaces in Program Path + parameters

cmd /c ""c:\Program Files\demo.cmd"" Parameter1 Param2

Spaces in Program Path + parameters with spaces

cmd /k ""c:\batch files\demo.cmd" "Parameter 1 with space" "Parameter2 with space""

Launch Demo1 and then Launch Demo2

cmd /c ""c:\Program Files\demo1.cmd" & "c:\Program Files\demo2.cmd""

CMD.exe (Command Shell)

SELECT * FROM multiple tables. MySQL

What you do here is called a JOIN (although you do it implicitly because you select from multiple tables). This means, if you didn't put any conditions in your WHERE clause, you had all combinations of those tables. Only with your condition you restrict your join to those rows where the drink id matches.

But there are still X multiple rows in the result for every drink, if there are X photos with this particular drinks_id. Your statement doesn't restrict which photo(s) you want to have!

If you only want one row per drink, you have to tell SQL what you want to do if there are multiple rows with a particular drinks_id. For this you need grouping and an aggregate function. You tell SQL which entries you want to group together (for example all equal drinks_ids) and in the SELECT, you have to tell which of the distinct entries for each grouped result row should be taken. For numbers, this can be average, minimum, maximum (to name some).

In your case, I can't see the sense to query the photos for drinks if you only want one row. You probably thought you could have an array of photos in your result for each drink, but SQL can't do this. If you only want any photo and you don't care which you'll get, just group by the drinks_id (in order to get only one row per drink):

SELECT name, price, photo
FROM drinks, drinks_photos
WHERE drinks.id = drinks_id 
GROUP BY drinks_id

name     price   photo
fanta    5       ./images/fanta-1.jpg
dew      4       ./images/dew-1.jpg

In MySQL, we also have GROUP_CONCAT, if you want the file names to be concatenated to one single string:

SELECT name, price, GROUP_CONCAT(photo, ',')
FROM drinks, drinks_photos
WHERE drinks.id = drinks_id 
GROUP BY drinks_id

name     price   photo
fanta    5       ./images/fanta-1.jpg,./images/fanta-2.jpg,./images/fanta-3.jpg
dew      4       ./images/dew-1.jpg,./images/dew-2.jpg

However, this can get dangerous if you have , within the field values, since most likely you want to split this again on the client side. It is also not a standard SQL aggregate function.

How to Set Selected value in Multi-Value Select in Jquery-Select2.?

no need to do so many things. for set value using multiple select2 var selectedvalue="1,2,3"; //if first 3 products are selected. $('#ddlProduct').val(selectedvalue);

What is the difference between id and class in CSS, and when should I use them?

  • Use a class when you want to consistently style multiple elements throughout the page/site. Classes are useful when you have, or possibly will have in the future, more than one element that shares the same style. An example may be a div of "comments" or a certain list style to use for related links.

    Additionally, a given element can have more than one class associated with it, while an element can only have one id. For example, you can give a div two classes whose styles will both take effect.

    Furthermore, note that classes are often used to define behavioral styles in addition to visual ones. For example, the jQuery form validator plugin heavily uses classes to define the validation behavior of elements (e.g. required or not, or defining the type of input format)

    Examples of class names are: tag, comment, toolbar-button, warning-message, or email.

  • Use the ID when you have a single element on the page that will take the style. Remember that IDs must be unique. In your case this may be the correct option, as there presumably will only be one "main" div on the page.

    Examples of ids are: main-content, header, footer, or left-sidebar.

A good way to remember this is a class is a type of item and the id is the unique name of an item on the page.

Get Selected value from Multi-Value Select Boxes by jquery-select2?

alert("Selected value is: "+$(".leaderMultiSelctdropdown").select2("val"));

alternatively, if you used a regular selectbox as base, you should be able to use the normal jquery call, too:

alert("Selected value is: "+$(".leaderMultiSelctdropdown").val());

both return an array of the selected keys.

How to create exe of a console application

The following steps are necessary to create .exe i.e. executable files which are as 1) Open visual studio framework 2) Then, create a new project or application 3) Build or execute your application by pressing F5