Programs & Examples On #Rfc5322

RFC5322 specifies the Internet Message Format (IMF), a syntax for text messages that are sent between computer users, within the framework of "electronic mail" messages.

Uncaught TypeError: Cannot read property 'toLowerCase' of undefined

When you call loadTeachers() on DOMReady the context of this will not be the #CourseSelect element.

You can fix this by triggering a change() event on the #CourseSelect element on load of the DOM:

$("#CourseSelect").change(loadTeachers).change(); // or .trigger('change');

Alternatively can use $.proxy to change the context the function runs under:

$("#CourseSelect").change(loadTeachers);
$.proxy(loadTeachers, $('#CourseSelect'))();

Or the vanilla JS equivalent of the above, bind():

$("#CourseSelect").change(loadTeachers);
loadTeachers.bind($('#CourseSelect'));

CSS get height of screen resolution

Adding to @Hendrik Eichler Answer, the n vh uses n% of the viewport's initial containing block.

.element{
    height: 50vh; /* Would mean 50% of Viewport height */
    width:  75vw; /* Would mean 75% of Viewport width*/
}

Also, the viewport height is for devices of any resolution, the view port height, width is one of the best ways (similar to css design using % values but basing it on the device's view port height and width)

vh
Equal to 1% of the height of the viewport's initial containing block.

vw
Equal to 1% of the width of the viewport's initial containing block.

vi
Equal to 1% of the size of the initial containing block, in the direction of the root element’s inline axis.

vb
Equal to 1% of the size of the initial containing block, in the direction of the root element’s block axis.

vmin
Equal to the smaller of vw and vh.

vmax
Equal to the larger of vw and vh.

Ref: https://developer.mozilla.org/en-US/docs/Web/CSS/length#Viewport-percentage_lengths

How to split elements of a list?

myList = [i.split('\t')[0] for i in myList] 

Python idiom to return first item or None

if mylist != []:

       print(mylist[0])

   else:

       print(None)

error running apache after xampp install

After changing main port from 80 to 8080 you have to change the config in XAMPP control panel as I show in the images:

1) enter image description here

2) enter image description here

3) enter image description here

Then restart the service and that's it !

CodeIgniter - File upload required validation

you can solve it by overriding the Run function of CI_Form_Validation

copy this function in a class which extends CI_Form_Validation .

This function will override the parent class function . Here i added only a extra check which can handle file also

/**
 * Run the Validator
 *
 * This function does all the work.
 *
 * @access  public
 * @return  bool
 */
function run($group = '') {
    // Do we even have any data to process?  Mm?
    if (count($_POST) == 0) {
        return FALSE;
    }

    // Does the _field_data array containing the validation rules exist?
    // If not, we look to see if they were assigned via a config file
    if (count($this->_field_data) == 0) {
        // No validation rules?  We're done...
        if (count($this->_config_rules) == 0) {
            return FALSE;
        }

        // Is there a validation rule for the particular URI being accessed?
        $uri = ($group == '') ? trim($this->CI->uri->ruri_string(), '/') : $group;

        if ($uri != '' AND isset($this->_config_rules[$uri])) {
            $this->set_rules($this->_config_rules[$uri]);
        } else {
            $this->set_rules($this->_config_rules);
        }

        // We're we able to set the rules correctly?
        if (count($this->_field_data) == 0) {
            log_message('debug', "Unable to find validation rules");
            return FALSE;
        }
    }

    // Load the language file containing error messages
    $this->CI->lang->load('form_validation');

    // Cycle through the rules for each field, match the
    // corresponding $_POST or $_FILES item and test for errors
    foreach ($this->_field_data as $field => $row) {
        // Fetch the data from the corresponding $_POST or $_FILES array and cache it in the _field_data array.
        // Depending on whether the field name is an array or a string will determine where we get it from.

        if ($row['is_array'] == TRUE) {

            if (isset($_FILES[$field])) {
                $this->_field_data[$field]['postdata'] = $this->_reduce_array($_FILES, $row['keys']);
            } else {
                $this->_field_data[$field]['postdata'] = $this->_reduce_array($_POST, $row['keys']);
            }
        } else {
            if (isset($_POST[$field]) AND $_POST[$field] != "") {
                $this->_field_data[$field]['postdata'] = $_POST[$field];
            } else if (isset($_FILES[$field]) AND $_FILES[$field] != "") {
                $this->_field_data[$field]['postdata'] = $_FILES[$field];
            }
        }

        $this->_execute($row, explode('|', $row['rules']), $this->_field_data[$field]['postdata']);
    }

    // Did we end up with any errors?
    $total_errors = count($this->_error_array);

    if ($total_errors > 0) {
        $this->_safe_form_data = TRUE;
    }

    // Now we need to re-set the POST data with the new, processed data
    $this->_reset_post_array();

    // No errors, validation passes!
    if ($total_errors == 0) {
        return TRUE;
    }

    // Validation fails
    return FALSE;
}

FileSystemWatcher Changed event is raised twice

Alot of these answers are shocking, really. Heres some code from my XanderUI Control library that fixes this.

private void OnChanged(object sender, FilesystemEventArgs e)
{
    if (FSWatcher.IncludeSubdirectories == true)
    {
        if (File.Exists(e.FullPath)) { DO YOUR FILE CHANGE STUFF HERE... }
    }
    else DO YOUR DIRECTORY CHANGE STUFF HERE...
}

SQL Server : trigger how to read value for Insert, Update, Delete

There is no updated dynamic table. There is just inserted and deleted. On an UPDATE command, the old data is stored in the deleted dynamic table, and the new values are stored in the inserted dynamic table.

Think of an UPDATE as a DELETE/INSERT combination.

How to upload & Save Files with Desired name

You can grab the demo source code from here: http://abhinavsingh.com/blog/2008/05/gmail-type-attachment-how-to-make-one/

It is ready to use, or you can modify to suit your application needs. Hope it helps :)

NodeJS - What does "socket hang up" actually mean?

Take a look at the source:

function socketCloseListener() {
  var socket = this;
  var parser = socket.parser;
  var req = socket._httpMessage;
  debug('HTTP socket close');
  req.emit('close');
  if (req.res && req.res.readable) {
    // Socket closed before we emitted 'end' below.
    req.res.emit('aborted');
    var res = req.res;
    res.on('end', function() {
      res.emit('close');
    });
    res.push(null);
  } else if (!req.res && !req._hadError) {
    // This socket error fired before we started to
    // receive a response. The error needs to
    // fire on the request.
    req.emit('error', createHangUpError());
    req._hadError = true;
  }
}

The message is emitted when the server never sends a response.

Set a variable if undefined in JavaScript

If you're a FP (functional programming) fan, Ramda has a neat helper function for this called defaultTo :

usage:

const result = defaultTo(30)(value)

It's more useful when dealing with undefined boolean values:

const result2 = defaultTo(false)(dashboard.someValue)

ImportError: No module named 'MySQL'

Try that out bud

sudo wget http://cdn.mysql.com//Downloads/Connector-Python/mysql-connector-python-2.1.3.tar.gz

gunzip mysql-connector-python-2.1.3.tar.gz

tar xf mysql-connector-python-2.1.3.tar

cd mysql-connector-python-2.1.3

sudo python3 setup.py install

How to make flexbox items the same size?

You could add flex-basis: 100% to achieve this.

Updated Example

.header {
  display: flex;
}

.item {
  flex-basis: 100%;
  text-align: center;
  border: 1px solid black;
}

For what it's worth, you could also use flex: 1 for the same results as well.

The shorthand of flex: 1 is the same as flex: 1 1 0, which is equivalent to:

.item {
  flex-grow: 1;
  flex-shrink: 1;
  flex-basis: 0;
  text-align: center;
  border: 1px solid black;
}

How to delete columns that contain ONLY NAs?

Because performance was really important for me, I benchmarked all the functions above.

NOTE: Data from @Simon O'Hanlon's post. Only with size 15000 instead of 10.

library(tidyverse)
library(microbenchmark)

set.seed(123)
df <- data.frame(id = 1:15000,
                 nas = rep(NA, 15000), 
                 vals = sample(c(1:3, NA), 15000,
                               repl = TRUE))
df

MadSconeF1 <- function(x) x[, colSums(is.na(x)) != nrow(x)]

MadSconeF2 <- function(x) x[colSums(!is.na(x)) > 0]

BradCannell <- function(x) x %>% select_if(~sum(!is.na(.)) > 0)

SimonOHanlon <- function(x) x[ , !apply(x, 2 ,function(y) all(is.na(y)))]

jsta <- function(x) janitor::remove_empty(x)

SiboJiang <- function(x) x %>% dplyr::select_if(~!all(is.na(.)))

akrun <- function(x) Filter(function(y) !all(is.na(y)), x)

mbm <- microbenchmark(
  "MadSconeF1" = {MadSconeF1(df)},
  "MadSconeF2" = {MadSconeF2(df)},
  "BradCannell" = {BradCannell(df)},
  "SimonOHanlon" = {SimonOHanlon(df)},
  "SiboJiang" = {SiboJiang(df)},
  "jsta" = {jsta(df)}, 
  "akrun" = {akrun(df)},
  times = 1000)

mbm

Results:

Unit: microseconds
         expr    min      lq      mean  median      uq      max neval  cld
   MadSconeF1  154.5  178.35  257.9396  196.05  219.25   5001.0  1000 a   
   MadSconeF2  180.4  209.75  281.2541  226.40  251.05   6322.1  1000 a   
  BradCannell 2579.4 2884.90 3330.3700 3059.45 3379.30  33667.3  1000    d
 SimonOHanlon  511.0  565.00  943.3089  586.45  623.65 210338.4  1000  b  
    SiboJiang 2558.1 2853.05 3377.6702 3010.30 3310.00  89718.0  1000    d
         jsta 1544.8 1652.45 2031.5065 1706.05 1872.65  11594.9  1000   c 
        akrun   93.8  111.60  139.9482  121.90  135.45   3851.2  1000 a


autoplot(mbm)

enter image description here

mbm %>% 
  tbl_df() %>%
  ggplot(aes(sample = time)) + 
  stat_qq() + 
  stat_qq_line() +
  facet_wrap(~expr, scales = "free")

enter image description here

Socket File "/var/pgsql_socket/.s.PGSQL.5432" Missing In Mountain Lion (OS X Server)

i make in word by doing this:

dpkg-reconfigure locales

and choose your preferred locales

pg_createcluster 9.5 main --start

(9.5 is my version of postgresql)

/etc/init.d/postgresql start

and then it word!

sudo su - postgres
psql

@JsonProperty annotation on field as well as getter/setter

In addition to existing good answers, note that Jackson 1.9 improved handling by adding "property unification", meaning that ALL annotations from difference parts of a logical property are combined, using (hopefully) intuitive precedence.

In Jackson 1.8 and prior, only field and getter annotations were used when determining what and how to serialize (writing JSON); and only and setter annotations for deserialization (reading JSON). This sometimes required addition of "extra" annotations, like annotating both getter and setter.

With Jackson 1.9 and above these extra annotations are NOT needed. It is still possible to add those; and if different names are used, one can create "split" properties (serializing using one name, deserializing using other): this is occasionally useful for sort of renaming.

What is the difference between map and flatMap and a good use case for each?

RDD.map returns all elements in single array

RDD.flatMap returns elements in Arrays of array

let's assume we have text in text.txt file as

Spark is an expressive framework
This text is to understand map and faltMap functions of Spark RDD

Using map

val text=sc.textFile("text.txt").map(_.split(" ")).collect

output:

text: **Array[Array[String]]** = Array(Array(Spark, is, an, expressive, framework), Array(This, text, is, to, understand, map, and, faltMap, functions, of, Spark, RDD))

Using flatMap

val text=sc.textFile("text.txt").flatMap(_.split(" ")).collect

output:

 text: **Array[String]** = Array(Spark, is, an, expressive, framework, This, text, is, to, understand, map, and, faltMap, functions, of, Spark, RDD)

Modifying Objects within stream in Java8 while iterating

This might be a little late. But here is one of the usage. This to get the count of the number of files.

Create a pointer to memory (a new obj in this case) and have the property of the object modified. Java 8 stream doesn't allow to modify the pointer itself and hence if you declare just count as a variable and try to increment within the stream it will never work and throw a compiler exception in the first place

Path path = Paths.get("/Users/XXXX/static/test.txt");



Count c = new Count();
            c.setCount(0);
            Files.lines(path).forEach(item -> {
                c.setCount(c.getCount()+1);
                System.out.println(item);});
            System.out.println("line count,"+c);

public static class Count{
        private int count;

        public int getCount() {
            return count;
        }

        public void setCount(int count) {
            this.count = count;
        }

        @Override
        public String toString() {
            return "Count [count=" + count + "]";
        }



    }

What is the maximum number of characters that nvarchar(MAX) will hold?

2^31-1 bytes. So, a little less than 2^31-1 characters for varchar(max) and half that for nvarchar(max).

nchar and nvarchar

Registry Key '...' has value '1.7', but '1.6' is required. Java 1.7 is Installed and the Registry is Pointing to it

For my Win7

Paradox was in being java.exe and javaw.exe in System32 folder. Opening that folder I couldn't see them but using search in Start menu I get links to those files, removed them. Next searsh gave me links to files from JAVA_HOME

magic )

How to check if running as root in a bash script

The problem using: id -u, $EUID and whoami is all of them give false positive when I fake the root, for example:

$ fakeroot

id:

$ id -u
0

EUID:

$ echo $EUID
0

whoami:

$ whoami
root

then a reliable and hacking way is verify if the user has access to the /root directory:

 $ ls /root/ &>/dev/null && is_root=true || is_root=false; echo $is_root

Setting network adapter metric priority in Windows 7

I had the same problem on Windows 7 64-bit Pro. I adjusted network adapters binding using Control panel but nothing changed. Also metrics where showing that Win should use Ethernet adapter as primary, but it didn't.

Then a tried to uninstall Ethernet adapter driver and then install it again (without restart) and then I checked metrics for sure.

After this, Windows started prioritize Ethernet adapter.

How to replace unicode characters in string with something else python?

Funny the answer is hidden in among the answers.

str.replace("•", "something") 

would work if you use the right semantics.

str.replace(u"\u2022","something") 

works wonders ;) , thnx to RParadox for the hint.

Eclipse won't compile/run java file

I was also in the same problem, check your build path in eclipse by Right Click on Project > build path > configure build path

Now check for Excluded Files, it should not have your file specified there by any means or by regex.

Cheers!image for error fix view, see Excluded field

Xcode - iPhone - profile doesn't match any valid certificate-/private-key pair in the default keychain

When I tried to select the development provisioning profile in Code Signing Identity is would say "profile doesn't match any valid certificate". So when I followed the two step process below it worked:

1) Under "Code Signing Identity" for Development change to "Don't Code Sign".
2) Then Under "Code Signing Identity" for Development you will be able to select your provisioning profile for Development.

Drove me nuts, but stumbled upon the solution.

How do I set ANDROID_SDK_HOME environment variable?

ANDROID_HOME

Deprecated (in Android Studio), use ANDROID_SDK_ROOT instead.

ANDROID_SDK_ROOT

Installation directory of Android SDK package.

Example: C:\AndroidSDK or /usr/local/android-sdk/

ANDROID_NDK_ROOT

Installation directory of Android NDK package. (WITHOUT ANY SPACE)

Example: C:\AndroidNDK or /usr/local/android-ndk/

ANDROID_SDK_HOME

Location of SDK related data/user files.

Example: C:\Users\<USERNAME>\.android\ or ~/.android/

ANDROID_EMULATOR_HOME

Location of emulator-specific data files.

Example: C:\Users\<USERNAME>\.android\ or ~/.android/

ANDROID_AVD_HOME

Location of AVD-specific data files.

Example: C:\Users\<USERNAME>\.android\avd\ or ~/.android/avd/

JDK_HOME and JAVA_HOME

Installation directory of JDK (aka Java SDK) package.

Note: This is used to run Android Studio(and other Java-based applications). Actually when you run Android Studio, it checks for JDK_HOME then JAVA_HOME environment variables to use.

What processes are using which ports on unix?

Given (almost) everything on unix is a file, and lsof lists open files...

Linux : netstat -putan or lsof | grep TCP

OSX : lsof | grep TCP

Other Unixen : lsof way...

Access a URL and read Data with R

scan can read from a web page automatically; you don't necessarily have to mess with connections.

How to discard all changes made to a branch?

If you don't want any changes in design and definitely want it to just match a remote's branch, you can also just delete the branch and recreate it:

# Switch to some branch other than design
$ git br -D design
$ git co -b design origin/design            # Will set up design to track origin's design branch

How to update Ruby to 1.9.x on Mac?

I'll make a strong suggestion for rvm.

It's a great way to manage multiple Rubies and gems sets without colliding with the system version.


I'll add that now (4/2/2013), I use rbenv a lot, because my needs are simple. RVM is great, but it's got a lot of capability I never need, so I have it on some machines and rbenv on my desktop and laptop. It's worth checking out both and seeing which works best for your needs.

Why my $.ajax showing "preflight is invalid redirect error"?

Please set http content type in header and also make sure the server is authenticating CORS. This is how to do it in PHP:

//NOT A TESTED CODE
header('Content-Type: application/json;charset=UTF-8');
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: DELETE, HEAD, GET, OPTIONS, POST, PUT');
header('Access-Control-Allow-Headers: Content-Type, Content-Range, Content-Disposition, Content-Description');
header('Access-Control-Max-Age: 1728000');

Please refer to:

http://www.w3.org/TR/cors/#cross-origin-request-with-preflight-0

How does Access-Control-Allow-Origin header work?

Variable declaration in a header file

You should declare the variable in a header file:

extern int x;

and then define it in one C file:

int x;

In C, the difference between a definition and a declaration is that the definition reserves space for the variable, whereas the declaration merely introduces the variable into the symbol table (and will cause the linker to go looking for it when it comes to link time).

How to insert multiple rows from array using CodeIgniter framework?

Although it is too late to answer this question. Here are my answer on the same.

If you are using CodeIgniter then you can use inbuilt methods defined in query_builder class.

$this->db->insert_batch()

Generates an insert string based on the data you supply, and runs the query. You can either pass an array or an object to the function. Here is an example using an array:

$data = array(
    array(
            'title' => 'My title',
            'name' => 'My Name',
            'date' => 'My date'
    ),
    array(
            'title' => 'Another title',
            'name' => 'Another Name',
            'date' => 'Another date'
    )
);

$this->db->insert_batch('mytable', $data);
// Produces: INSERT INTO mytable (title, name, date) VALUES ('My title', 'My name', 'My date'),  ('Another title', 'Another name', 'Another date')

The first parameter will contain the table name, the second is an associative array of values.

You can find more details about query_builder here

what is the basic difference between stack and queue?

To try and over-simplify the description of a stack and a queue, They are both dynamic chains of information elements that can be accessed from one end of the chain and the only real difference between them is the fact that:

when working with a stack

  • you insert elements at one end of the chain and
  • you retrieve and/or remove elements from the same end of the chain

while with a queue

  • you insert elements at one end of the chain and
  • you retrieve/remove them from the other end

NOTE: I am using the abstract wording of retrieve/remove in this context because there are instances when you just retrieve the element from the chain or in a sense just read it or access its value, but there also instances when you remove the element from the chain and finally there are instances when you do both actions with the same call.

Also the word element is purposely used in order to abstract the imaginary chain as much as possible and decouple it from specific programming language terms. This abstract information entity called element could be anything, from a pointer, a value, a string or characters, an object,... depending on the language.

In most cases, though it is actually either a value or a memory location (i.e. a pointer). And the rest are just hiding this fact behind the language jargon<

A queue can be helpful when the order of the elements is important and needs to be exactly the same as when the elements first came into your program. For instance when you process an audio stream or when you buffer network data. Or when you do any type of store and forward processing. In all of these cases you need the sequence of the elements to be output in the same order as they came into your program, otherwise the information may stop making sense. So, you could break your program in a part that reads data from some input, does some processing and writes them in a queue and a part that retrieves data from the queue processes them and stores them in another queue for further processing or transmitting the data.

A stack can be helpful when you need to temporarily store an element that is going to be used in the immediate step(s) of your program. For instance, programming languages usually use a stack structure to pass variables to functions. What they actually do is store (or push) the function arguments in the stack and then jump to the function where they remove and retrieve (or pop) the same number of elements from the stack. That way the size of the stack is dependent of the number of nested calls of functions. Additionally, after a function has been called and finished what it was doing, it leaves the stack in the exact same condition as before it has being called! That way any function can operate with the stack ignoring how other functions operate with it.

Lastly, you should know that there are other terms used out-there for the same of similar concepts. For instance a stack could be called a heap. There are also hybrid versions of these concepts, for instance a double-ended queue can behave at the same time as a stack and as a queue, because it can be accessed by both ends simultaneously. Additionally, the fact that a data structure is provided to you as a stack or as a queue it does not necessarily mean that it is implemented as such, there are instances in which a data structure can be implemented as anything and be provided as a specific data structure simply because it can be made to behave like such. In other words, if you provide a push and pop method to any data structure, they magically become stacks!

Show/Hide the console window of a C# console application

Why do you need a console application if you want to hide console itself? =)

I recommend setting Project Output type to Windows Application instead of Console application. It will not show you console window, but execute all actions, like Console application do.

Posting raw image data as multipart/form-data in curl

As of PHP 5.6 @$filePath will not work in CURLOPT_POSTFIELDS without CURLOPT_SAFE_UPLOAD being set and it is completely removed in PHP 7. You will need to use a CurlFile object, RFC here.

$fields = [
    'name' => new \CurlFile($filePath, 'image/png', 'filename.png')
];
curl_setopt($resource, CURLOPT_POSTFIELDS, $fields);

Password encryption/decryption code in .NET

This question will answer how to encrypt/decrypt: Encrypt and decrypt a string in C#?

You didn't specify a database, but you will want to base-64 encode it, using Convert.toBase64String. For an example you can use: http://www.opinionatedgeek.com/Blog/blogentry=000361/BlogEntry.aspx

You'll then either save it in a varchar or a blob, depending on how long your encrypted message is, but for a password varchar should work.

The examples above will also cover decryption after decoding the base64.

UPDATE:

In actuality you may not need to use base64 encoding, but I found it helpful, in case I wanted to print it, or send it over the web. If the message is long enough it's best to compress it first, then encrypt, as it is harder to use brute-force when the message was already in a binary form, so it would be hard to tell when you successfully broke the encryption.

How to create cron job using PHP?

Create a cronjob like this to work on every minute

*       *       *       *       *       /usr/bin/php path/to/cron.php &> /dev/null

How to find all occurrences of an element in a list

If you need to search for all element's positions between certain indices, you can state them:

[i for i,x in enumerate([1,2,3,2]) if x==2 & 2<= i <=3] # -> [3]

Returning a boolean from a Bash function

Following up on @Bruno Bronosky and @mrteatime, I offer the suggestion that you just write your boolean return "backwards". This is what I mean:

foo()
{
    if [ "$1" == "bar" ]; then
        true; return
    else
        false; return
    fi;
}

That eliminates the ugly two line requirement for every return statement.

Get difference between two lists

In [5]: list(set(temp1) - set(temp2))
Out[5]: ['Four', 'Three']

Beware that

In [5]: set([1, 2]) - set([2, 3])
Out[5]: set([1]) 

where you might expect/want it to equal set([1, 3]). If you do want set([1, 3]) as your answer, you'll need to use set([1, 2]).symmetric_difference(set([2, 3])).

How to add button in ActionBar(Android)?

you have to create an entry inside res/menu,override onCreateOptionsMenu and inflate it

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.yourentry, menu);
    return true;
}

an entry for the menu could be:

<menu xmlns:android="http://schemas.android.com/apk/res/android" >
    <item
        android:id="@+id/action_cart"
        android:icon="@drawable/cart"
        android:orderInCategory="100"
        android:showAsAction="always"/> 
</menu>

How to change Bootstrap's global default font size?

I just solved this type of problem. I was trying to increase

font-size to h4 size. I do not want to use h4 tag. I added my css after bootstrap.css it didn't work. The easiest way is this: On the HTML doc, type

<p class="h4">

You do not need to add anything to your css sheet. It works fine Question is suppose I want a size between h4 and h5? Answer why? Is this the only way to please your viewers? I will prefer this method to tampering with standard docs like bootstrap.

Insert a string at a specific index

Take the solution. I have written this code in an easy format:

const insertWord = (sentence,word,index) => {
    var sliceWord = word.slice(""),output = [],join; // Slicing the input word and declaring other variables
    var sliceSentence = sentence.slice(""); // Slicing the input sentence into each alphabets
    for (var i = 0; i < sliceSentence.length; i++) 
           {
        if (i === index) 
               { // checking if index of array === input index
            for (var j = 0; j < word.length; j++) 
                       {   // if yes we'll insert the word
                output.push(sliceWord[j]); // Condition is true we are inserting the word
                       }
            output.push(" "); // providing a single space at the end of the word
                 }
        output.push(sliceSentence[i]);  // pushing the remaining elements present in an array
            }
    join = output.join(""); // converting an array to string
    console.log(join)
    return join;
}

How can I get dictionary key as variable directly in Python (not by searching from value)?

easily change the position of your keys and values,then use values to get key, in dictionary keys can have same value but they(keys) should be different. for instance if you have a list and the first value of it is a key for your problem and other values are the specs of the first value:

list1=["Name",'ID=13736','Phone:1313','Dep:pyhton']

you can save and use the data easily in Dictionary by this loop:

data_dict={}
for i in range(1, len(list1)):
     data_dict[list1[i]]=list1[0]
print(data_dict)
{'ID=13736': 'Name', 'Phone:1313': 'Name', 'Dep:pyhton': 'Name'}

then you can find the key(name) base on any input value.

PSQLException: current transaction is aborted, commands ignored until end of transaction block

Check the output before the statement that caused current transaction is aborted. This typically means that database threw an exception that your code had ignored and now expecting next queries to return some data.

So you now have a state mismatch between your application, which considers things are fine, and database, that requires you to rollback and re-start your transaction from the beginning.

You should catch all exceptions and rollback transactions in such cases.

Here's a similar issue.

IIS Express gives Access Denied error when debugging ASP.NET MVC

Hosting on IIS Express: 1. Click on your project in the Solution Explorer to select the project. 2. If the Properties pane is not open, open it (F4). 3. In the Properties pane for your project: a) Set "Anonymous Authentication" to "Disabled". b) Set "Windows Authentication" to "Enabled".

TypeError: unsupported operand type(s) for -: 'list' and 'list'

The operations needed to be performed, require numpy arrays either created via

np.array()

or can be converted from list to an array via

np.stack()

As in the above mentioned case, 2 lists are inputted as operands it triggers the error.

How can I find the number of arguments of a Python function?

inspect.getargspec()

Get the names and default values of a function’s arguments. A tuple of four things is returned: (args, varargs, varkw, defaults). args is a list of the argument names (it may contain nested lists). varargs and varkw are the names of the * and ** arguments or None. defaults is a tuple of default argument values or None if there are no default arguments; if this tuple has n elements, they correspond to the last n elements listed in args.

Changed in version 2.6: Returns a named tuple ArgSpec(args, varargs, keywords, defaults).

See can-you-list-the-keyword-arguments-a-python-function-receives.

Displaying the Error Messages in Laravel after being Redirected from controller

{!! Form::text('firstname', null !!}

@if($errors->has('firstname')) 
    {{ $errors->first('firstname') }} 
@endif

Dynamically Changing log4j log level

File Watchdog

Log4j is able to watch the log4j.xml file for configuration changes. If you change the log4j file, log4j will automatically refresh the log levels according to your changes. See the documentation of org.apache.log4j.xml.DOMConfigurator.configureAndWatch(String,long) for details. The default wait time between checks is 60 seconds. These changes would be persistent, since you directly change the configuration file on the filesystem. All you need to do is to invoke DOMConfigurator.configureAndWatch() once.

Caution: configureAndWatch method is unsafe for use in J2EE environments due to a Thread leak

JMX

Another way to set the log level (or reconfiguring in general) log4j is by using JMX. Log4j registers its loggers as JMX MBeans. Using the application servers MBeanServer consoles (or JDK's jconsole.exe) you can reconfigure each individual loggers. These changes are not persistent and would be reset to the config as set in the configuration file after you restart your application (server).

Self-Made

As described by Aaron, you can set the log level programmatically. You can implement it in your application in the way you would like it to happen. For example, you could have a GUI where the user or admin changes the log level and then call the setLevel() methods on the logger. Whether you persist the settings somewhere or not is up to you.

How to set array length in c# dynamically

You could use List inside the method and transform it to an array at the end. But i think if we talk about an max-value of 20, your code is faster.

    private Update BuildMetaData(MetaData[] nvPairs)
    {
        Update update = new Update();
        List<InputProperty> ip = new List<InputProperty>();
        for (int i = 0; i < nvPairs.Length; i++)
        {
            if (nvPairs[i] == null) break;
            ip[i] = new InputProperty();
            ip[i].Name = "udf:" + nvPairs[i].Name;
            ip[i].Val = nvPairs[i].Value;
        }
        update.Items = ip.ToArray();
        return update;
    }

No Spring WebApplicationInitializer types detected on classpath

In my case it also turned into a multi-hour debugging session. Trying to set up a more verbose logging turned out to be completely futile because the problem was that my application did not even start. Here's my context.xml:

<?xml version='1.0' encoding='utf-8'?>
<Context path="/rc2" docBase="rc2" antiResourceLocking="false" >
    <JarScanner>
        <JarScanFilter
            tldScan="spring-webmvc*.jar, spring-security-taglibs*.jar, jakarta.servlet.jsp.jstl*.jar"
            tldSkip="*.jar"
            <!-- my-own-app*.jar on the following line was missing! -->
            pluggabilityScan="${tomcat.util.scan.StandardJarScanFilter.jarsToScan}, my-own-app*.jar"
            pluggabilitySkip="*.jar"/>
    </JarScanner>
</Context>

The problem was that to speed up the application startup, I started skipping scanning of many JARs, unfortunately including my own application.

Android Studio suddenly cannot resolve symbols

Android Studio 1.3

  1. Open Module Settings
  2. Click on your module under Modules menu
  3. In the properties tab, set the Source Compatibility and Target Compatibility to your java version.

I did nothing else and it worked for me.

Download Excel file via AJAX MVC

The accepted answer didn't quite work for me as I got a 502 Bad Gateway result from the ajax call even though everything seemed to be returning fine from the controller.

Perhaps I was hitting a limit with TempData - not sure, but I found that if I used IMemoryCache instead of TempData, it worked fine, so here is my adapted version of the code in the accepted answer:

public ActionResult PostReportPartial(ReportVM model){

   // Validate the Model is correct and contains valid data
   // Generate your report output based on the model parameters
   // This can be an Excel, PDF, Word file - whatever you need.

   // As an example lets assume we've generated an EPPlus ExcelPackage

   ExcelPackage workbook = new ExcelPackage();
   // Do something to populate your workbook

   // Generate a new unique identifier against which the file can be stored
   string handle = Guid.NewGuid().ToString();

   using(MemoryStream memoryStream = new MemoryStream()){
        workbook.SaveAs(memoryStream);
        memoryStream.Position = 0;
        //TempData[handle] = memoryStream.ToArray();

        //This is an equivalent to tempdata, but requires manual cleanup
        _cache.Set(handle, memoryStream.ToArray(), 
                    new MemoryCacheEntryOptions().SetSlidingExpiration(TimeSpan.FromMinutes(10))); 
                    //(I'd recommend you revise the expiration specifics to suit your application)

   }      

   // Note we are returning a filename as well as the handle
   return new JsonResult() { 
         Data = new { FileGuid = handle, FileName = "TestReportOutput.xlsx" }
   };

}

AJAX call remains as with the accepted answer (I made no changes):

$ajax({
    cache: false,
    url: '/Report/PostReportPartial',
    data: _form.serialize(), 
    success: function (data){
         var response = JSON.parse(data);
         window.location = '/Report/Download?fileGuid=' + response.FileGuid 
                           + '&filename=' + response.FileName;
    }
})

The controller action to handle the downloading of the file:

[HttpGet]
public virtual ActionResult Download(string fileGuid, string fileName)
{   
    if (_cache.Get<byte[]>(fileGuid) != null)
    {
        byte[] data = _cache.Get<byte[]>(fileGuid);
        _cache.Remove(fileGuid); //cleanup here as we don't need it in cache anymore
        return File(data, "application/vnd.ms-excel", fileName);
    }
    else
    {
        // Something has gone wrong...
        return View("Error"); // or whatever/wherever you want to return the user
    }
}

...

Now there is some extra code for setting up MemoryCache...

In order to use "_cache" I injected in the constructor for the controller like so:

using Microsoft.Extensions.Caching.Memory;
namespace MySolution.Project.Controllers
{
 public class MyController : Controller
 {
     private readonly IMemoryCache _cache;

     public LogController(IMemoryCache cache)
     {
        _cache = cache;
     }

     //rest of controller code here
  }
 }

And make sure you have the following in ConfigureServices in Startup.cs:

services.AddDistributedMemoryCache();

How to plot data from multiple two column text files with legends in Matplotlib?

Assume your file looks like this and is named test.txt (space delimited):

1 2
3 4
5 6
7 8

Then:

#!/usr/bin/python

import numpy as np
import matplotlib.pyplot as plt

with open("test.txt") as f:
    data = f.read()

data = data.split('\n')

x = [row.split(' ')[0] for row in data]
y = [row.split(' ')[1] for row in data]

fig = plt.figure()

ax1 = fig.add_subplot(111)

ax1.set_title("Plot title...")    
ax1.set_xlabel('your x label..')
ax1.set_ylabel('your y label...')

ax1.plot(x,y, c='r', label='the data')

leg = ax1.legend()

plt.show()

Example plot:

I find that browsing the gallery of plots on the matplotlib site helpful for figuring out legends and axes labels.

Run Python script at startup in Ubuntu

Instructions

  • Copy the python file to /bin:

    sudo cp -i /path/to/your_script.py /bin

  • Add A New Cron Job:

    sudo crontab -e

    Scroll to the bottom and add the following line (after all the #'s):

    @reboot python /bin/your_script.py &

    The “&” at the end of the line means the command is run in the background and it won’t stop the system booting up.

  • Test it:

    sudo reboot

Practical example:

  • Add this file to your Desktop: test_code.py (run it to check that it works for you)

    from os.path import expanduser
    import datetime
    
    file = open(expanduser("~") + '/Desktop/HERE.txt', 'w')
    file.write("It worked!\n" + str(datetime.datetime.now()))
    file.close()
    
  • Run the following commands:

    sudo cp -i ~/Desktop/test_code.py /bin

    sudo crontab -e

  • Add the following line and save it:

    @reboot python /bin/test_code.py &

  • Now reboot your computer and you should find a new file on your Desktop: HERE.txt

Xcode stops working after set "xcode-select -switch"

You should be pointing it towards the Developer directory, not the Xcode application bundle. Run this:

sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer

With recent versions of Xcode, you can go to Xcode ? Preferences… ? Locations and pick one of the options for Command Line Tools to set the location.

Import functions from another js file. Javascript

The following works for me in Firefox and Chrome. In Firefox it even works from file:///

models/course.js

export function Course() {
    this.id = '';
    this.name = '';
};

models/student.js

import { Course } from './course.js';

export function Student() {
    this.firstName = '';
    this.lastName = '';
    this.course = new Course();
};

index.html

<div id="myDiv">
</div>
<script type="module">
    import { Student } from './models/student.js';

    window.onload = function () {
        var x = new Student();
        x.course.id = 1;
        document.getElementById('myDiv').innerHTML = x.course.id;
    }
</script>

Variable length (Dynamic) Arrays in Java

How about using a List instead? For example, ArrayList<integer>

TypeScript sorting an array

Great answer Sohnee. Would like to add that if you have an array of objects and you wish to sort by key then its almost the same, this is an example of one that can sort by both date(number) or title(string):

    if (sortBy === 'date') {
        return n1.date - n2.date
    } else {
        if (n1.title > n2.title) {
           return 1;
        }
        if (n1.title < n2.title) {
            return -1;
        }
        return 0;
    }

Could also make the values inside as variables n1[field] vs n2[field] if its more dynamic, just keep the diff between strings and numbers.

Escape regex special characters in a Python string

Use repr()[1:-1]. In this case, the double quotes don't need to be escaped. The [-1:1] slice is to remove the single quote from the beginning and the end.

>>> x = raw_input()
I'm "stuck" :\
>>> print x
I'm "stuck" :\
>>> print repr(x)[1:-1]
I\'m "stuck" :\\

Or maybe you just want to escape a phrase to paste into your program? If so, do this:

>>> raw_input()
I'm "stuck" :\
'I\'m "stuck" :\\'

Java String encoding (UTF-8)

How is this different from the following?

This line of code here:

String newString = new String(oldString.getBytes("UTF-8"), "UTF-8"));

constructs a new String object (i.e. a copy of oldString), while this line of code:

String newString = oldString;

declares a new variable of type java.lang.String and initializes it to refer to the same String object as the variable oldString.

Is there any scenario in which the two lines will have different outputs?

Absolutely:

String newString = oldString;
boolean isSameInstance = newString == oldString; // isSameInstance == true

vs.

String newString = new String(oldString.getBytes("UTF-8"), "UTF-8"));
 // isSameInstance == false (in most cases)    
boolean isSameInstance = newString == oldString;

a_horse_with_no_name (see comment) is right of course. The equivalent of

String newString = new String(oldString.getBytes("UTF-8"), "UTF-8"));

is

String newString = new String(oldString);

minus the subtle difference wrt the encoding that Peter Lawrey explains in his answer.

Search File And Find Exact Match And Print Line?

num = raw_input ("Type Number : ")
search = open("file.txt","r")
for line in search.readlines():
    for digit in num:
        # Check if any of the digits provided by the user are in the line.
        if digit in line:
            print line
            continue

Calling Javascript from a html form

Pretty example by Miquel (#32) should be refilled:

<html>
 <head>
  <script type="text/javascript">
   function handleIt(txt) {   // txt == content of form input
    alert("Entered value: " + txt);
   }
  </script>
 </head>
 <body>
 <!-- javascript function in form action must have a parameter. This 
    parameter contains a value of named input -->
  <form name="myform" action="javascript:handleIt(lastname.value)">  
   <input type="text" name="lastname" id="lastname" maxlength="40"> 
   <input name="Submit"  type="submit" value="Update"/>
  </form>
 </body>
</html>

And the form should have:

<form name="myform" action="javascript:handleIt(lastname.value)"> 

Error: could not find function "%>%"

On Windows: if you use %>% inside a %dopar% loop, you have to add a reference to load package dplyr (or magrittr, which dplyr loads).

Example:

plots <- foreach(myInput=iterators::iter(plotCount), .packages=c("RODBC", "dplyr")) %dopar%
{
    return(getPlot(myInput))
}

If you omit the .packages command, and use %do% instead to make it all run in a single process, then works fine. The reason is that it all runs in one process, so it doesn't need to specifically load new packages.

Getting all selected checkboxes in an array

_x000D_
_x000D_
function selectedValues(ele){_x000D_
  var arr = [];_x000D_
  for(var i = 0; i < ele.length; i++){_x000D_
    if(ele[i].type == 'checkbox' && ele[i].checked){_x000D_
      arr.push(ele[i].value);_x000D_
    }_x000D_
  }_x000D_
  return arr;_x000D_
}
_x000D_
_x000D_
_x000D_

jQuery $.ajax request of dataType json will not retrieve data from PHP script

If you are using a newer version (over 1.3.x) you should learn more about the function parseJSON! I experienced the same problem. Use an old version or change your code

success=function(data){
  //something like this
  jQuery.parseJSON(data)
}

Run AVD Emulator without Android Studio

For Linux/Ubuntu

Create a new File from Terminal as

gedit emulator.sh (Use any Name for file here i have used "emulator")

now write following lines in this file

cd /home/userName/Android/Sdk/tools/

./emulator @your created Android device Name

(here after @ write the name of your AVD e.g

./emulator @Nexus_5X_API_27 )

Now save the file and run your emulator using following commands

./emulator.sh

In case of Permission denied use following command before above command

chmod +x emulator.sh

All set Go..

Correct way to pass multiple values for same parameter name in GET request

there is no standard, but most frameworks support both, you can see for example for java spring that it accepts both here

@GetMapping("/api/foos")
@ResponseBody
public String getFoos(@RequestParam List<String> id) {
    return "IDs are " + id;
}

And Spring MVC will map a comma-delimited id parameter:

http://localhost:8080/api/foos?id=1,2,3
----
IDs are [1,2,3]

Or a list of separate id parameters:

http://localhost:8080/api/foos?id=1&id=2
----
IDs are [1,2]

How to get client IP address in Laravel 5+

Looking at the Laravel API:

Request::ip();

Internally, it uses the getClientIps method from the Symfony Request Object:

public function getClientIps()
{
    $clientIps = array();
    $ip = $this->server->get('REMOTE_ADDR');
    if (!$this->isFromTrustedProxy()) {
        return array($ip);
    }
    if (self::$trustedHeaders[self::HEADER_FORWARDED] && $this->headers->has(self::$trustedHeaders[self::HEADER_FORWARDED])) {
        $forwardedHeader = $this->headers->get(self::$trustedHeaders[self::HEADER_FORWARDED]);
        preg_match_all('{(for)=("?\[?)([a-z0-9\.:_\-/]*)}', $forwardedHeader, $matches);
        $clientIps = $matches[3];
    } elseif (self::$trustedHeaders[self::HEADER_CLIENT_IP] && $this->headers->has(self::$trustedHeaders[self::HEADER_CLIENT_IP])) {
        $clientIps = array_map('trim', explode(',', $this->headers->get(self::$trustedHeaders[self::HEADER_CLIENT_IP])));
    }
    $clientIps[] = $ip; // Complete the IP chain with the IP the request actually came from
    $ip = $clientIps[0]; // Fallback to this when the client IP falls into the range of trusted proxies
    foreach ($clientIps as $key => $clientIp) {
        // Remove port (unfortunately, it does happen)
        if (preg_match('{((?:\d+\.){3}\d+)\:\d+}', $clientIp, $match)) {
            $clientIps[$key] = $clientIp = $match[1];
        }
        if (IpUtils::checkIp($clientIp, self::$trustedProxies)) {
            unset($clientIps[$key]);
        }
    }
    // Now the IP chain contains only untrusted proxies and the client IP
    return $clientIps ? array_reverse($clientIps) : array($ip);
} 

How do you convert a JavaScript date to UTC?

Here's my method:

var now = new Date();
var utc = new Date(now.getTime() + now.getTimezoneOffset() * 60000);

The resulting utc object isn't really a UTC date, but a local date shifted to match the UTC time (see comments). However, in practice it does the job.

Xcode 6.1 Missing required architecture X86_64 in file

  • The first thing you should make sure is that your static library has all architectures. When you do a lipo -info myStaticLibrary.a on terminal - you should see armv7 armv7s i386 x86_64 arm64 architectures for your fat binary.

  • To accomplish that, I am assuming that you're making a universal binary - add the following to your architecture settings of static library project -

enter image description here

  • So, you can see that I have to manually set the Standard architectures (including 64-bit) (armv7, armv7s, arm64) of the static library project.

enter image description here

  • Alternatively, since the normal $ARCHS_STANDARD now includes 64-bit. You can also do $(ARCHS_STANDARD) and armv7s. Check lipo -info without it, and you'll figure out the missing architectures. Here's the screenshot for all architectures -

enter image description here

  • For your reference implementation (project using static library). The default settings should work fine -

    enter image description here

Update 12/03/14 Xcode 6 Standard architectures exclude armv7s.

So, armv7s is not needed? Yes. It seems that the general differences between armv7 and armv7s instruction sets are minor. So if you choose not to include armv7s, the targeted armv7 machine code still runs fine on 32 bit A6 devices, and hardly one will notice performance gap. Source

If there is a smarter way for Xcode 6.1+ (iOS 8.1 and above) - please share.

JQuery: detect change in input field

You can use jQuery change() function

$('input').change(function(){
  //your codes
});

There are examples on how to use it on the API Page: http://api.jquery.com/change/

SyntaxError: cannot assign to operator

Instead of ((t[1])/length) * t[1] += string, you should use string += ((t[1])/length) * t[1]. (The other syntax issue - int is not iterable - will be your exercise to figure out.)

Converting EditText to int? (Android)

First, find your EditText in the resource of the android studio by using this code:

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

Then convert EditText value into a string and then parse the value to an int.

int number = Integer.parseInt(x.getText().toString());

This will work

how to customize `show processlist` in mysql?

You can just capture the output and pass it through a filter, something like:

mysql show processlist
    | grep -v '^\+\-\-'
    | grep -v '^| Id'
    | sort -n -k12

The two greps strip out the header and trailer lines (others may be needed if there are other lines not containing useful information) and the sort is done based on the numeric field number 12 (I think that's right).

This one works for your immediate output:

mysql show processlist
    | grep -v '^\+\-\-'
    | grep -v '^| Id'
    | grep -v  '^[0-9][0-9]* rows in set '
    | grep -v '^ '
    | sort -n -k12

How to prevent Screen Capture in Android

I saw all of the answers which are appropriate only for a single activity but there is my solution which will block screenshot for all of the activities without adding any code to the activity. First of all make an Custom Application class and add a registerActivityLifecycleCallbacks.Then register it in your manifest.

MyApplicationContext.class

public class MyApplicationContext extends Application {
    private  Context context;
    public void onCreate() {
        super.onCreate();
        context = getApplicationContext();
        setupActivityListener();
    }

    private void setupActivityListener() {
        registerActivityLifecycleCallbacks(new ActivityLifecycleCallbacks() {
            @Override
            public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
                activity.getWindow().setFlags(WindowManager.LayoutParams.FLAG_SECURE, WindowManager.LayoutParams.FLAG_SECURE);            }
            @Override
            public void onActivityStarted(Activity activity) {
            }
            @Override
            public void onActivityResumed(Activity activity) {

            }
            @Override
            public void onActivityPaused(Activity activity) {

            }
            @Override
            public void onActivityStopped(Activity activity) {
            }
            @Override
            public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
            }
            @Override
            public void onActivityDestroyed(Activity activity) {
            }
        });
    }



}

Manifest

 <application
        android:name=".MyApplicationContext"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

Access blocked by CORS policy: Response to preflight request doesn't pass access control check

Since the originating port 4200 is different than 8080,So before angular sends a create (PUT) request,it will send an OPTIONS request to the server to check what all methods and what all access-controls are in place. Server has to respond to that OPTIONS request with list of allowed methods and allowed origins.

Since you are using spring boot, the simple solution is to add ".allowedOrigins("http://localhost:4200");"

In your spring config,class

@Configuration
@EnableWebMvc
public class SpringConfig implements WebMvcConfigurer {

    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**").allowedOrigins("http://localhost:4200");
    }
}

However a better approach will be to write a Filter(interceptor) which adds the necessary headers to each response.

Android Studio how to run gradle sync manually?

In Android Studio 3.3 it is here:

enter image description here

According to the answer https://stackoverflow.com/a/49576954/2914140 in Android Studio 3.1 it is here:

enter image description here

This command is moved to File > Sync Project with Gradle Files.

enter image description here

Dismissing a Presented View Controller

I think Apple are covering their backs a little here for a potentially kludgy piece of API.

  [self dismissViewControllerAnimated:NO completion:nil]

Is actually a bit of a fiddle. Although you can - legitimately - call this on the presented view controller, all it does is forward the message on to the presenting view controller. If you want to do anything over and above just dismissing the VC, you will need to know this, and you need to treat it much the same way as a delegate method - as that's pretty much what it is, a baked-in somewhat inflexible delegate method.

Perhaps they've come across loads of bad code by people not really understanding how this is put together, hence their caution.

But of course, if all you need to do is dismiss the thing, go ahead.

My own approach is a compromise, at least it reminds me what is going on:

  [[self presentingViewController] dismissViewControllerAnimated:NO completion:nil]

[Swift]

  self.presentingViewController?.dismiss(animated: false, completion:nil)

Efficiently getting all divisors of a given number

for (int i = 1; i*i <= num; ++i)
{
    if (num % i == 0)
    cout << i << endl;
    if (num/i!=i)
    cout << num/i << endl;
}

Concatenating strings in C, which method is more efficient?

Here's some madness for you, I actually went and measured it. Bloody hell, imagine that. I think I got some meaningful results.

I used a dual core P4, running Windows, using mingw gcc 4.4, building with "gcc foo.c -o foo.exe -std=c99 -Wall -O2".

I tested method 1 and method 2 from the original post. Initially kept the malloc outside the benchmark loop. Method 1 was 48 times faster than method 2. Bizarrely, removing -O2 from the build command made the resulting exe 30% faster (haven't investigated why yet).

Then I added a malloc and free inside the loop. That slowed down method 1 by a factor of 4.4. Method 2 slowed down by a factor of 1.1.

So, malloc + strlen + free DO NOT dominate the profile enough to make avoiding sprintf worth while.

Here's the code I used (apart from the loops were implemented with < instead of != but that broke the HTML rendering of this post):

void a(char *first, char *second, char *both)
{
    for (int i = 0; i != 1000000 * 48; i++)
    {
        strcpy(both, first);
        strcat(both, " ");
        strcat(both, second);
    }
}

void b(char *first, char *second, char *both)
{
    for (int i = 0; i != 1000000 * 1; i++)
        sprintf(both, "%s %s", first, second);
}

int main(void)
{
    char* first= "First";
    char* second = "Second";
    char* both = (char*) malloc((strlen(first) + strlen(second) + 2) * sizeof(char));

    // Takes 3.7 sec with optimisations, 2.7 sec WITHOUT optimisations!
    a(first, second, both);

    // Takes 3.7 sec with or without optimisations
    //b(first, second, both);

    return 0;
}

what do <form action="#"> and <form method="post" action="#"> do?

The # tag lets you send your data to the same file. I see it as a three step process:

  1. Query a DB to populate a from
  2. Allow the user to change data in the form
  3. Resubmit the data to the DB via the php script

With the method='#' you can do all of this in the same file.

After the submit query is executed the page will reload with the updated data from the DB.

Change the bullet color of list

Example JS Fiddle

Bullets take the color property of the list:

.listStyle {
    color: red;
}

Note if you want your list text to be a different colour, you have to wrap it in say, a p, for example:

.listStyle p {
    color: black;
}

Example HTML:

<ul class="listStyle">
    <li>
        <p><strong>View :</strong> blah blah.</p>
    </li>
    <li>
        <p><strong>View :</strong> blah blah.</p>
    </li>
</ul>

Cannot uninstall angular-cli

If you are facing issue with angular/cli then use the following commands:
npm uninstall -g angular-cli to uninstall the angular/cli.
npm cache clean to clean your npm cache from app data folder under your username.
use npm cache verify to verify your cache whether it is corrupted or not.
use npm cache verify --force to clean your entire cache from your system.

Note:
You can also delete by the following the paths
C:\Users\"Your_syste_User_name"\AppData\Roaming\npm and
C:\Users\"Your_syste_User_name"\AppData\Roaming\npm-cache
Then use the following command to install latest angular/cli version globally in your system.
npm install -g @angular/cli@latest
To get more information visit github angular-cli update.

How do I check if a list is empty?

if not a:
  print("List is empty")

Using the implicit booleanness of the empty list is quite pythonic.

How to use JavaScript source maps (.map files)?

  • How can a developer use it?

I didn't find answer for this in the comments, here is how can be used:

  1. Don't link your js.map file in your index.html file (no need for that)
  2. Minifiacation tools (good ones) add a comment to your .min.js file:

    //# sourceMappingURL=yourFileName.min.js.map

which will connect your .map file.

When the min.js and js.map files are ready...

  1. Chrome: Open dev-tools, navigate to Sources tab, You will see sources folder, where un-minified applications files are kept.

Handling ExecuteScalar() when no results are returned

private static string GetUserNameById(string sId, string connStr)
    {
        System.Data.SqlClient.SqlConnection conn = new System.Data.SqlClient.SqlConnection(connStr);
        System.Data.SqlClient.SqlCommand command;

        try
        {
            // To be Assigned with Return value from DB
            object getusername;

            command = new System.Data.SqlClient.SqlCommand();

            command.CommandText = "Select userName from [User] where userid = @userid";

            command.Parameters.AddWithValue("@userid", sId);

            command.CommandType = CommandType.Text;

            conn.Open();

            command.Connection = conn;

            //Execute
            getusername = command.ExecuteScalar();

            //check for null due to non existent value in db and return default empty string
            string UserName = getusername == null ? string.Empty : getusername.ToString();

            return UserName;


        }
        catch (Exception ex)
        {

            throw new Exception("Could not get username", ex);
        }
        finally
        {
            conn.Close();
        }

    }

SQL Server: Best way to concatenate multiple columns?

Blockquote

Using concatenation in Oracle SQL is very easy and interesting. But don't know much about MS-SQL.

Blockquote

Here we go for Oracle : Syntax: SQL> select First_name||Last_Name as Employee from employees;

Result: EMPLOYEE

EllenAbel SundarAnde MozheAtkinson

Here AS: keyword used as alias. We can concatenate with NULL values. e.g. : columnm1||Null

Suppose any of your columns contains a NULL value then the result will show only the value of that column which has value.

You can also use literal character string in concatenation.

e.g. select column1||' is a '||column2 from tableName; Result: column1 is a column2. in between literal should be encolsed in single quotation. you cna exclude numbers.

NOTE: This is only for oracle server//SQL.

Can't connect to MySQL server on 'localhost' (10061)

To resolve this problem:

  1. go to the task manager
  2. select Services tab
  3. find MySql service
  4. Running

That's all.

What is the use of hashCode in Java?

From the Javadoc:

Returns a hash code value for the object. This method is supported for the benefit of hashtables such as those provided by java.util.Hashtable.

The general contract of hashCode is:

  • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.

  • If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.

  • It is not required that if two objects are unequal according to the equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hashtables.

As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the Java programming language.)

Create Carriage Return in PHP String?

Fragment PHP (in console Cloud9):

echo "\n";
echo "1: first_srt=1\nsecnd_srt=2\n";
echo "\n";
echo '2: first_srt=1\nsecnd_srt=2\n';
echo "\n";
echo "==============\n";
echo "\n";

resulting output:

  1: first_srt=1
  secnd_srt=2

  2: first_srt=1\nsecnd_srt=2\n
  ==============

Difference between 1 and 2: " versus '

Add space between HTML elements only using CSS

A good way to do it is this:

span + span {
    margin-left: 10px;
}

Every span preceded by a span (so, every span except the first) will have margin-left: 10px.

Here's a more detailed answer to a similar question: Separators between elements without hacks

TypeError: unhashable type: 'list' when using built-in set function

Sets require their items to be hashable. Out of types predefined by Python only the immutable ones, such as strings, numbers, and tuples, are hashable. Mutable types, such as lists and dicts, are not hashable because a change of their contents would change the hash and break the lookup code.

Since you're sorting the list anyway, just place the duplicate removal after the list is already sorted. This is easy to implement, doesn't increase algorithmic complexity of the operation, and doesn't require changing sublists to tuples:

def uniq(lst):
    last = object()
    for item in lst:
        if item == last:
            continue
        yield item
        last = item

def sort_and_deduplicate(l):
    return list(uniq(sorted(l, reverse=True)))

How to check db2 version

In z/OS while on version 10, use of CURRENT APPLICATION COMPATIBILITY is not allowed. You will have to resort to:

SELECT GETVARIABLE('SYSIBM.VERSION') AS VERSION,
       GETVARIABLE('SYSIBM.NEWFUN')  AS COMPATIBILITY
FROM SYSIBM.SYSDUMMY1;

Here is a link to all the variables available: https://www.ibm.com/support/knowledgecenter/SSEPEK_12.0.0/sqlref/src/tpc/db2z_refs2builtinsessionvars.html#db2z_refs2builtinsessionvars

Plotting a 2D heatmap with Matplotlib

The imshow() function with parameters interpolation='nearest' and cmap='hot' should do what you want.

import matplotlib.pyplot as plt
import numpy as np

a = np.random.random((16, 16))
plt.imshow(a, cmap='hot', interpolation='nearest')
plt.show()

enter image description here

addClass and removeClass in jQuery - not removing class

why not simplify it?

jquery

$('.clickable').on('click', function() {//on parent click
    $(this).removeClass('spot').addClass('grown');//use remove/add Class here because it needs to perform the same action every time, you don't want a toggle
}).children('.close_button').on('click', function(e) {//on close click
    e.stopPropagation();//stops click from triggering on parent
    $(this).parent().toggleClass('spot grown');//since this only appears when .grown is present, toggling will work great instead of add/remove Class and save some space
});

This way it's much easier to maintain.

made a fiddle: http://jsfiddle.net/filever10/3SmaV/

POST an array from an HTML form without javascript

check this one out.

<input type="text" name="firstname">
<input type="text" name="lastname">
<input type="text" name="email">
<input type="text" name="address">

<input type="text" name="tree[tree1][fruit]">
<input type="text" name="tree[tree1][height]">

<input type="text" name="tree[tree2][fruit]">
<input type="text" name="tree[tree2][height]">

<input type="text" name="tree[tree3][fruit]">
<input type="text" name="tree[tree3][height]">

it should end up like this in the $_POST[] array (PHP format for easy visualization)

$_POST[] = array(
    'firstname'=>'value',
    'lastname'=>'value',
    'email'=>'value',
    'address'=>'value',
    'tree' => array(
        'tree1'=>array(
            'fruit'=>'value',
            'height'=>'value'
        ),
        'tree2'=>array(
            'fruit'=>'value',
            'height'=>'value'
        ),
        'tree3'=>array(
            'fruit'=>'value',
            'height'=>'value'
        )
    )
)

center aligning a fixed position div

<div class="container-div">
  <div class="center-div">

  </div>
</div>

.container-div {position:fixed; left: 0; bottom: 0; width: 100%; margin: 0;}
.center-div {width: 200px; margin: 0 auto;}

This should do the same.

How do I bind Twitter Bootstrap tooltips to dynamically created elements?

Rather than search it in full Body. One could just use dynamic title option already available in such scenarios I think:

$btn.tooltip({
  title: function(){
    return $(this).attr('title');
  }
});

Change font color and background in html on mouseover

It would be great if you use :hover pseudo class over the onmouseover event

td:hover
{
   background-color:white
}

and for the default styling just use

td
{
  background-color:black
}

As you want to use these styling not over all the td elements then you need to specify the class to those elements and add styling to that class like this

.customTD
{
   background-color:black
}
.customTD:hover
{
  background-color:white;
}

You can also use :nth-child selector to select the td elements

How to change color in markdown cells ipython/jupyter notebook?

<p style="font-family: Arial; font-size:1.4em;color:gold;"> Golden </p>

or

Text <span style="font-family: Arial; font-size:1.4em;color:gold;"> Golden </p> Text

How to sort an array of ints using a custom comparator?

If you can't change the type of your input array the following will work:

final int[] data = new int[] { 5, 4, 2, 1, 3 };
final Integer[] sorted = ArrayUtils.toObject(data);
Arrays.sort(sorted, new Comparator<Integer>() {
    public int compare(Integer o1, Integer o2) {
        // Intentional: Reverse order for this demo
        return o2.compareTo(o1);
    }
});
System.arraycopy(ArrayUtils.toPrimitive(sorted), 0, data, 0, sorted.length);

This uses ArrayUtils from the commons-lang project to easily convert between int[] and Integer[], creates a copy of the array, does the sort, and then copies the sorted data over the original.

How to make my font bold using css?

You can use the strong element in html, which is great semantically (also good for screen readers etc.), which typically renders as bold text:

_x000D_
_x000D_
See here, some <strong>emphasized text</strong>.
_x000D_
_x000D_
_x000D_

Or you can use the font-weight css property to style any element's text as bold:

_x000D_
_x000D_
span { font-weight: bold; }
_x000D_
<p>This is a paragraph of <span>bold text</span>.</p>
_x000D_
_x000D_
_x000D_

Get current AUTO_INCREMENT value for any table

You can get all of the table data by using this query:

SHOW TABLE STATUS FROM `DatabaseName` WHERE `name` LIKE 'TableName' ;

You can get exactly this information by using this query:

SELECT `AUTO_INCREMENT`
FROM  INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = 'DatabaseName'
AND   TABLE_NAME   = 'TableName';

Updating PartialView mvc 4

Thanks all for your help! Finally I used JQuery/AJAX as you suggested, passing the parameter using model.

So, in JS:

$('#divPoints').load('/Schedule/UpdatePoints', UpdatePointsAction);
var points= $('#newpoints').val();
$element.find('PointsDiv').html("You have" + points+ " points");

In Controller:

var model = _newPoints;
return PartialView(model);

In View

<div id="divPoints"></div>
@Html.Hidden("newpoints", Model)

Vim autocomplete for Python

Try Jedi! There's a Vim plugin at https://github.com/davidhalter/jedi-vim.

It works just much better than anything else for Python in Vim. It even has support for renaming, goto, etc. The best part is probably that it really tries to understand your code (decorators, generators, etc. Just look at the feature list).

How do I remove javascript validation from my eclipse project?

I removed the tag in the .project .

    <buildCommand>
        <name>org.eclipse.wst.jsdt.core.javascriptValidator</name>
        <arguments>
        </arguments>
    </buildCommand>

It's worked very well for me.

CSS background image URL failing to load

source URL for image can be a URL on a website like http://www.google.co.il/images/srpr/nav_logo73.png or https://https.openbsd.org/images/tshirt-26_front.gif or if you want to use a local file try this: url("file:///MacintoshHDOriginal/Users/lowri/Desktop/acgnx/image s/images/acgn-site-background-X_07.jpg")

How can I move a tag on a git branch to a different commit?

More precisely, you have to force the addition of the tag, then push with option --tags and -f:

git tag -f -a <tagname>
git push -f --tags

Alternative for PHP_excel

For Writing Excel

  • PEAR's PHP_Excel_Writer (xls only)
  • php_writeexcel from Bettina Attack (xls only)
  • XLS File Generator commercial and xls only
  • Excel Writer for PHP from Sourceforge (spreadsheetML only)
  • Ilia Alshanetsky's Excel extension now on github (xls and xlsx, and requires commercial libXL component)
  • PHP's COM extension (requires a COM enabled spreadsheet program such as MS Excel or OpenOffice Calc running on the server)
  • The Open Office alternative to COM (PUNO) (requires Open Office installed on the server with Java support enabled)
  • PHP-Export-Data by Eli Dickinson (Writes SpreadsheetML - the Excel 2003 XML format, and CSV)
  • Oliver Schwarz's php-excel (SpreadsheetML)
  • Oliver Schwarz's original version of php-excel (SpreadsheetML)
  • excel_xml (SpreadsheetML, despite its name)... link reported as broken
  • The tiny-but-strong (tbs) project includes the OpenTBS tool for creating OfficeOpenXML documents (OpenDocument and OfficeOpenXML formats)
  • SimpleExcel Claims to read and write Microsoft Excel XML / CSV / TSV / HTML / JSON / etc formats
  • KoolGrid xls spreadsheets only, but also doc and pdf
  • PHP_XLSXWriter OfficeOpenXML
  • PHP_XLSXWriter_plus OfficeOpenXML, fork of PHP_XLSXWriter
  • php_writeexcel xls only (looks like it's based on PEAR SEW)
  • spout OfficeOpenXML (xlsx) and CSV
  • Slamdunk/php-excel (xls only) looks like an updated version of the old PEAR Spreadsheet Writer

For Reading Excel

A new C++ Excel extension for PHP, though you'll need to build it yourself, and the docs are pretty sparse when it comes to trying to find out what functionality (I can't even find out from the site what formats it supports, or whether it reads or writes or both.... I'm guessing both) it offers is phpexcellib from SIMITGROUP.

All claim to be faster than PHPExcel from codeplex or from github, but (with the exception of COM, PUNO Ilia's wrapper around libXl and spout) they don't offer both reading and writing, or both xls and xlsx; may no longer be supported; and (while I haven't tested Ilia's extension) only COM and PUNO offers the same degree of control over the created workbook.

How to make war file in Eclipse

File -> Export -> Web -> WAR file

OR in Kepler follow as shown below :

enter image description here

Use of PUT vs PATCH methods in REST API real life scenarios

Let me quote and comment more closely the RFC 7231 section 4.2.2, already cited in earlier comments :

A request method is considered "idempotent" if the intended effect on the server of multiple identical requests with that method is the same as the effect for a single such request. Of the request methods defined by this specification, PUT, DELETE, and safe request methods are idempotent.

(...)

Idempotent methods are distinguished because the request can be repeated automatically if a communication failure occurs before the client is able to read the server's response. For example, if a client sends a PUT request and the underlying connection is closed before any response is received, then the client can establish a new connection and retry the idempotent request. It knows that repeating the request will have the same intended effect, even if the original request succeeded, though the response might differ.

So, what should be "the same" after a repeated request of an idempotent method? Not the server state, nor the server response, but the intended effect. In particular, the method should be idempotent "from the point of view of the client". Now, I think that this point of view shows that the last example in Dan Lowe's answer, which I don't want to plagiarize here, indeed shows that a PATCH request can be non-idempotent (in a more natural way than the example in Jason Hoetger's answer).

Indeed, let's make the example slightly more precise by making explicit one possible intend for the first client. Let's say that this client goes through the list of users with the project to check their emails and zip codes. He starts with user 1, notices that the zip is right but the email is wrong. He decides to correct this with a PATCH request, which is fully legitimate, and sends only

PATCH /users/1
{"email": "[email protected]"}

since this is the only correction. Now, the request fails because of some network issue and is re-submitted automatically a couple of hours later. In the meanwhile, another client has (erroneously) modified the zip of user 1. Then, sending the same PATCH request a second time does not achieve the intended effect of the client, since we end up with an incorrect zip. Hence the method is not idempotent in the sense of the RFC.

If instead the client uses a PUT request to correct the email, sending to the server all properties of user 1 along with the email, his intended effect will be achieved even if the request has to be re-sent later and user 1 has been modified in the meanwhile --- since the second PUT request will overwrite all changes since the first request.

Notepad++ Regular expression find and delete a line

If it supports standard regex...

find:
^.*#RedirectMatch Permanent.*$

replace:

Replace with nothing.

Reloading submodules in IPython

For some reason, neither %autoreload, nor dreload seem to work for the situation when you import code from one notebook to another. Only plain Python reload works:

reload(module)

Based on [1].

How would you implement an LRU cache in Java?

Android offers an implementation of an LRU Cache. The code is clean and straightforward.

Install php-mcrypt on CentOS 6

If you want to recompile PHP with mcrypt enable.

1. Insatll mcrypt. libmcrypt-devel is from Third Party Repositories EPEL, so you should:

yum --enablerepo=extras install epel-release
yum install libmcrypt-devel

2. Append --with-mcrypt to your ./configure arguments:

./configure --with-mcrypt

3. Build and install:

make & make install

How to drop a PostgreSQL database if there are active connections to it?

Nothing worked for me except, I loggined using pgAdmin4 and on the Dashboard I disconnected all connections except pgAdmin4 and then was able to rename by right lick on the database and properties and typed new name.

Creating multiple log files of different content with log4j

Demo link: https://github.com/RazvanSebastian/spring_multiple_log_files_demo.git

My solution is based on XML configuration using spring-boot-starter-log4j. The example is a basic example using spring-boot-starter and the two Loggers writes into different log files.

Disable dragging an image from an HTML page

You may consider my solution the best. Most of answers are not compatible with old browsers like IE8 since e.preventDefault() wont be supported as well as ondragstart event. To do it cross browser compatible you have to block mousemove event for this image. See example below:

jQuery

$("#my_image").mousemove( function(e) { return false } ); // fix for IE
$("#my_image").attr("draggable", false); // disable dragging from attribute

without jQuery

var my_image = document.getElementById("my_image");
my_image.setAttribute("draggable", false);

if (my_image.addEventListener) {
   my_image.addEventListener("mousemove", function(e) { return false });
} else if (my_image.attachEvent) {
   my_image.attachEvent("onmousemove", function(e) { return false });
}

tested and worked even for IE8

How to extract base URL from a string in JavaScript?

If you are extracting information from window.location.href (the address bar), then use this code to get http://www.sitename.com/:

var loc = location;
var url = loc.protocol + "//" + loc.host + "/";

If you have a string, str, that is an arbitrary URL (not window.location.href), then use regular expressions:

var url = str.match(/^(([a-z]+:)?(\/\/)?[^\/]+\/).*$/)[1];

I, like everyone in the Universe, hate reading regular expressions, so I'll break it down in English:

  • Find zero or more alpha characters followed by a colon (the protocol, which can be omitted)
  • Followed by // (can also be omitted)
  • Followed by any characters except / (the hostname and port)
  • Followed by /
  • Followed by whatever (the path, less the beginning /).

No need to create DOM elements or do anything crazy.

Stripping non printable characters from a string in python

Yet another option in python 3:

re.sub(f'[^{re.escape(string.printable)}]', '', my_string)

What are POD types in C++?

Very informally:

A POD is a type (including classes) where the C++ compiler guarantees that there will be no "magic" going on in the structure: for example hidden pointers to vtables, offsets that get applied to the address when it is cast to other types (at least if the target's POD too), constructors, or destructors. Roughly speaking, a type is a POD when the only things in it are built-in types and combinations of them. The result is something that "acts like" a C type.

Less informally:

  • int, char, wchar_t, bool, float, double are PODs, as are long/short and signed/unsigned versions of them.
  • pointers (including pointer-to-function and pointer-to-member) are PODs,
  • enums are PODs
  • a const or volatile POD is a POD.
  • a class, struct or union of PODs is a POD provided that all non-static data members are public, and it has no base class and no constructors, destructors, or virtual methods. Static members don't stop something being a POD under this rule. This rule has changed in C++11 and certain private members are allowed: Can a class with all private members be a POD class?
  • Wikipedia is wrong to say that a POD cannot have members of type pointer-to-member. Or rather, it's correct for the C++98 wording, but TC1 made explicit that pointers-to-member are POD.

Formally (C++03 Standard):

3.9(10): "Arithmetic types (3.9.1), enumeration types, pointer types, and pointer to member types (3.9.2) and cv-qualified versions of these types (3.9.3) are collectively caller scalar types. Scalar types, POD-struct types, POD-union types (clause 9), arrays of such types and cv-qualified versions of these types (3.9.3) are collectively called POD types"

9(4): "A POD-struct is an aggregate class that has no non-static data members of type non-POD-struct, non-POD-union (or array of such types) or reference, and has no user-define copy operator and no user-defined destructor. Similarly a POD-union is an aggregate union that has no non-static data members of type non-POD-struct, non-POD-union (or array of such types) or reference, and has no user-define copy operator and no user-defined destructor.

8.5.1(1): "An aggregate is an array or class (clause 9) with no user-declared constructors (12.1), no private or protected non-static data members (clause 11), no base classes (clause 10) and no virtual functions (10.3)."

failed to resolve com.android.support:appcompat-v7:22 and com.android.support:recyclerview-v7:21.1.2

Go to Messages Gradle Sync, and Click on Install Repository and sync project. This is will install needed file in Android SDK and after syncing you will be able to create gradle or run your project.

How do I print to the debug output window in a Win32 app?

You can also use WriteConsole method to print on console.

AllocConsole();
LPSTR lpBuff = "Hello Win32 API";
DWORD dwSize = 0;
WriteConsole(GetStdHandle(STD_OUTPUT_HANDLE), lpBuff, lstrlen(lpBuff), &dwSize, NULL);

How to get current timestamp in string format in Java? "yyyy.MM.dd.HH.mm.ss"

A more appropriate approach is to specify a Locale region as a parameter in the constructor. The example below uses a US Locale region. Date formatting is locale-sensitive and uses the Locale to tailor information relative to the customs and conventions of the user's region Locale (Java Platform SE 7)

String timeStamp = new SimpleDateFormat("yyyy.MM.dd.HH.mm.ss", Locale.US).format(new Date());

C# : Converting Base Class to Child Class

As long as the object is actually a SkyfilterClient, then a cast should work. Here is a contrived example to prove this:

using System;

class Program
{
    static void Main()
    {
        NetworkClient net = new SkyfilterClient();
        var sky = (SkyfilterClient)net;
    }
}

public class NetworkClient{}
public class SkyfilterClient : NetworkClient{}

However, if it is actually a NetworkClient, then you cannot magically make it become the subclass. Here is an example of that:

using System;

class Program
{
    static void Main()
    {
        NetworkClient net = new NetworkClient();
        var sky = (SkyfilterClient)net;
    }
}

public class NetworkClient{}
public class SkyfilterClient : NetworkClient{}

HOWEVER, you could create a converter class. Here is an example of that, also:

using System;

class Program
{
    static void Main()
    {
        NetworkClient net = new NetworkClient();
        var sky = SkyFilterClient.CopyToSkyfilterClient(net);
    }
}

public class NetworkClient
{  
  public int SomeVal {get;set;}
}

public class SkyfilterClient : NetworkClient
{
    public int NewSomeVal {get;set;}
    public static SkyfilterClient CopyToSkyfilterClient(NetworkClient networkClient)
    {
        return new SkyfilterClient{NewSomeVal = networkClient.SomeVal};
    }
}

But, keep in mind that there is a reason you cannot convert this way. You may be missing key information that the subclass needs.

Finally, if you just want to see if the attempted cast will work, then you can use is:

if(client is SkyfilterClient)
    cast

How do I change the figure size with subplots?

If you already have the figure object use:

f.set_figheight(15)
f.set_figwidth(15)

But if you use the .subplots() command (as in the examples you're showing) to create a new figure you can also use:

f, axs = plt.subplots(2,2,figsize=(15,15))

jquery stop child triggering parent event

Or, rather than having an extra event handler to prevent another handler, you can use the Event Object argument passed to your click event handler to determine whether a child was clicked. target will be the clicked element and currentTarget will be the .header div:

$(".header").click(function(e){
     //Do nothing if .header was not directly clicked
     if(e.target !== e.currentTarget) return;

     $(this).children(".children").toggle();
});

fork() child and parent processes

This is the correct way for getting the correct output.... However, childs parent id maybe sometimes printed as 1 because parent process gets terminated and the root process with pid = 1 controls this orphan process.

 pid_t  pid;
 pid = fork();
 if (pid == 0) 
    printf("This is the child process. My pid is %d and my parent's id 
      is %d.\n", getpid(), getppid());
 else 
     printf("This is the parent process. My pid is %d and my parent's 
         id is %d.\n", getpid(), pid);

What is the difference between java and core java?

I think when you see the phrase "core Java," they are talking about the basics of the language and maybe some knowledge of Java SE. I don't know why they would bother to put the "core" on there.

How do I compare two string variables in an 'if' statement in Bash?

I would suggest:

#!/bin/bash

s1="hi"
s2="hi"

if [ $s1 = $s2 ]
then
  echo match
fi

Without the double quotes and with only one equals.

Flutter: Setting the height of the AppBar

If you are in Visual Code, Ctrl + Click on AppBar function.

Widget demoPage() {
  AppBar appBar = AppBar(
    title: Text('Demo'),
  );
  return Scaffold(
    appBar: appBar,
    body: /*
    page body
    */,
  );
}

And edit this piece.

app_bar.dart will open and you can find 
    preferredSize = new Size.fromHeight(kToolbarHeight + (bottom?.preferredSize?.height ?? 0.0)),

Difference of height!

sample image

sample image

Reading a string with spaces with sscanf

The following line will start reading a number (%d) followed by anything different from tabs or newlines (%[^\t\n]).

sscanf("19 cool kid", "%d %[^\t\n]", &age, buffer);

When is TCP option SO_LINGER (0) required?

In servers, you may like to send RST instead of FIN when disconnecting misbehaving clients. That skips FIN-WAIT followed by TIME-WAIT socket states in the server, which prevents from depleting server resources, and, hence, protects from this kind of denial-of-service attack.

How to create a new variable in a data.frame based on a condition?

If you have a very limited number of levels, you could try converting y into factor and change its levels.

> xy <- data.frame(x = c(1, 2, 4), y = c(1, 4, 5))
> xy$w <- as.factor(xy$y)
> levels(xy$w) <- c("good", "fair", "bad")
> xy
  x y    w
1 1 1 good
2 2 4 fair
3 4 5  bad

How to initialize log4j properly?

Find a log4j.properties or log4j.xml online that has a root appender, and put it on your classpath.

### direct log messages to stdout ###
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.SimpleLayout
log4j.rootLogger=debug, stdout

will log to the console. I prefer logging to a file so you can investigate afterwards.

log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.maxFileSize=100KB
log4j.appender.file.maxBackupIndex=5
log4j.appender.file.File=test.log
log4j.appender.file.threshold=debug
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n
log4j.rootLogger=debug,file

although for verbose logging applications 100KB usually needs to be increased to 1MB or 10MB, especially for debug.

Personally I set up multiple loggers, and set the root logger to warn or error level instead of debug.

Is there a way to check if a file is in use?

You can suffer from a thread race condition on this which there are documented examples of this being used as a security vulnerability. If you check that the file is available, but then try and use it you could throw at that point, which a malicious user could use to force and exploit in your code.

Your best bet is a try catch / finally which tries to get the file handle.

try
{
   using (Stream stream = new FileStream("MyFilename.txt", FileMode.Open))
   {
        // File/Stream manipulating code here
   }
} catch {
  //check here why it failed and ask user to retry if the file is in use.
}

iterating through Enumeration of hastable keys throws NoSuchElementException error

You are calling nextElement twice. Refactor like this:

while(e.hasMoreElements()){


String param = (String) e.nextElement();
System.out.println(param);
}

jQuery: keyPress Backspace won't fire?

Use keyup instead of keypress. This gets all the key codes when the user presses something

How do I export an Android Studio project?

It seems as if Android Studio is missing some features Eclipse has (which is surprising considering the choice to make Android Studio official IDE).

Eclipse had the ability to export zip files which could be sent over email for example. If you zip the folder from your workspace, and try to send it over Gmail for example, Gmail will refuse because the folder contains executable. Obviously you can delete files but that is inefficient if you do that frequently going back and forth from work.

Here's a solution though: You can use source control. Android Studio supports that. Your code will be stored online. A git will do the trick. Look under "VCS" in the top menu in Android Studio. It has many other benefits as well. One of the downsides though, is that if you use GitHub for free, your code is open source and everyone can see it.

Python pandas: how to specify data types when reading an Excel file?

If you don't know the column names and you want to specify str data type to all columns:

table = pd.read_excel("path_to_filename")
cols = table.columns
conv = dict(zip(cols ,[str] * len(cols)))
table = pd.read_excel("path_to_filename", converters=conv)

Factorial using Recursion in Java

What happens is that the recursive call itself results in further recursive behaviour. If you were to write it out you get:

 fact(4)
 fact(3) * 4;
 (fact(2) * 3) * 4;
 ((fact(1) * 2) * 3) * 4;
 ((1 * 2) * 3) * 4;

How can I get the current page's full URL on a Windows/IIS server?

I have used the following code, and I am getting the right result...

<?php
    function currentPageURL() {
        $curpageURL = 'http';
        if ($_SERVER["HTTPS"] == "on") {
            $curpageURL.= "s";
        }
        $curpageURL.= "://";
        if ($_SERVER["SERVER_PORT"] != "80") {
            $curpageURL.= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
        } 
        else {
            $curpageURL.= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];
        }
        return $curpageURL;
    }
    echo currentPageURL();
?>

How to print the full NumPy array, without truncation?

Use numpy.set_printoptions:

import sys
import numpy
numpy.set_printoptions(threshold=sys.maxsize)

Why is using "for...in" for array iteration a bad idea?

Short answer: It's just not worth it.


Longer answer: It's just not worth it, even if sequential element order and optimal performance aren't required.


Long answer: It's just not worth it...

  • Using for (var property in array) will cause array to be iterated over as an object, traversing the object prototype chain and ultimately performing slower than an index-based for loop.
  • for (... in ...) is not guaranteed to return the object properties in sequential order, as one might expect.
  • Using hasOwnProperty() and !isNaN() checks to filter the object properties is an additional overhead causing it to perform even slower and negates the key reason for using it in the first place, i.e. because of the more concise format.

For these reasons an acceptable trade-off between performance and convenience doesn't even exist. There's really no benefit unless the intent is to handle the array as an object and perform operations on the object properties of the array.

HTML input fields does not get focus when clicked

This will also happen anytime a div ends up positioned over controls in another div; like using bootstrap for layout, and having a "col-lg-4" followed by a "col-lg=8" misspelling... the right orphaned/misnamed div covers the left, and captures the mouse events. Easy to blow by that misspelling, - and = next to each other on keyboard. So, pays to examine with inspector and look for 'surprises' to uncover these wild divs.

Is there an unseen window covering the controls and blocking events, and how can that happen? Turns out, fatfingering = for - with bootstrap classnames is one way...

jQuery-UI datepicker default date

You can try with the code that is below.

It will make the default date become the date you are looking for.

$('#birthdate').datepicker("setDate", new Date(1985,01,01) );

What's the best way to share data between activities?

Well I have a few ideas, but I don't know if they are what your looking for.

You could use a service that holds all of the data and then just bind your activities to the service for data retrival.

Or package your data into a serializable or parcelable and attach them to a bundle and pass the bundle between activities.

This one may not be at all what your looking for, but you could also try using a SharedPreferences or a preference in general.

Either way let me know what you decide.

Google Maps Api v3 - find nearest markers

Use computeDistanceBetween() Google map API method to calculate near marker between your location and markers list on google map.

Steps:-

  1. Create marker on google map.
    function addMarker(location) { var marker = new google.maps.Marker({ title: 'User added marker', icon: { path: google.maps.SymbolPath.BACKWARD_CLOSED_ARROW, scale: 5 }, position: location, map: map }); }

  2. On Mouse click create event for getting lat, long of your location and pass that to find_closest_marker().

    function find_closest_marker(event) {
          var distances = [];
          var closest = -1;
          for (i = 0; i < markers.length; i++) {
            var d = google.maps.geometry.spherical.computeDistanceBetween(markers[i].position, event.latLng);
            distances[i] = d;
            if (closest == -1 || d < distances[closest]) {
              closest = i;
            }
          }
          alert('Closest marker is: ' + markers[closest].getTitle());
        }
    

visit this link follow the steps. You will able to get nearer marker to your location.

Hibernate: best practice to pull all lazy collections

It's probably not anywhere approaching a best practice, but I usually call a SIZE on the collection to load the children in the same transaction, like you have suggested. It's clean, immune to any changes in the structure of the child elements, and yields SQL with low overhead.

Typescript: Type X is missing the following properties from type Y length, pop, push, concat, and 26 more. [2740]

This error could also be because you are not subscribing to the Observable.

Example, instead of:

this.products = this.productService.getProducts();

do this:

   this.productService.getProducts().subscribe({
    next: products=>this.products = products,
    error: err=>this.errorMessage = err
   });

Changing all files' extensions in a folder with one command on Windows

I know this is so old, but i've landed on it , and the provided answers didn't works for me on powershell so after searching found this solution

to do it in powershell

Get-ChildItem -Path C:\Demo -Filter *.txt | Rename-Item -NewName {[System.IO.Path]::ChangeExtension($_.Name, ".old")}

credit goes to http://powershell-guru.com/powershell-tip-108-bulk-rename-extensions-of-files/

Represent space and tab in XML tag

I had the same issue and none of the above answers solved the problem, so I tried something very straight-forward: I just putted in my strings.xml \n\t

The complete String looks like this <string name="premium_features_listing_3">- Automatische Aktualisierung der\n\tDatenbank</string>

Results in:

  • Automatische Aktualisierung der

    Datenbank

(with no extra line in between)

Maybe it will help others. Regards

Sql connection-string for localhost server

When using SQL Express, you need to specify \SQLExpress instance in your connection string:

string str = "Data Source=HARIHARAN-PC\\SQLEXPRESS;Initial Catalog=master;Integrated Security=True" ;

Switch statement for string matching in JavaScript

You can't do it in a switch unless you're doing full string matching; that's doing substring matching. (This isn't quite true, as Sean points out in the comments. See note at the end.)

If you're happy that your regex at the top is stripping away everything that you don't want to compare in your match, you don't need a substring match, and could do:

switch (base_url_string) {
    case "xxx.local":
        // Blah
        break;
    case "xxx.dev.yyy.com":
        // Blah
        break;
}

...but again, that only works if that's the complete string you're matching. It would fail if base_url_string were, say, "yyy.xxx.local" whereas your current code would match that in the "xxx.local" branch.


Update: Okay, so technically you can use a switch for substring matching, but I wouldn't recommend it in most situations. Here's how (live example):

function test(str) {
    switch (true) {
      case /xyz/.test(str):
        display("• Matched 'xyz' test");
        break;
      case /test/.test(str):
        display("• Matched 'test' test");
        break;
      case /ing/.test(str):
        display("• Matched 'ing' test");
        break;
      default:
        display("• Didn't match any test");
        break;
    }
}

That works because of the way JavaScript switch statements work, in particular two key aspects: First, that the cases are considered in source text order, and second that the selector expressions (the bits after the keyword case) are expressions that are evaluated as that case is evaluated (not constants as in some other languages). So since our test expression is true, the first case expression that results in true will be the one that gets used.

Use space as a delimiter with cut command

I just discovered that you can also use "-d ":

cut "-d "

Test

$ cat a
hello how are you
I am fine
$ cut "-d " -f2 a
how
am

git push >> fatal: no configured push destination

I have faced this error, Previous I had push in root directory, and now I have push another directory, so I could be remove this error and run below commands.

git add .
git commit -m "some comments"
git push --set-upstream origin master

python capitalize first letter only

Only because no one else has mentioned it:

>>> 'bob'.title()
'Bob'
>>> 'sandy'.title()
'Sandy'
>>> '1bob'.title()
'1Bob'
>>> '1sandy'.title()
'1Sandy'

However, this would also give

>>> '1bob sandy'.title()
'1Bob Sandy'
>>> '1JoeBob'.title()
'1Joebob'

i.e. it doesn't just capitalize the first alphabetic character. But then .capitalize() has the same issue, at least in that 'joe Bob'.capitalize() == 'Joe bob', so meh.

Removing a list of characters in string

Also an interesting topic on removal UTF-8 accent form a string converting char to their standard non-accentuated char:

What is the best way to remove accents in a python unicode string?

code extract from the topic:

import unicodedata

def remove_accents(input_str):
    nkfd_form = unicodedata.normalize('NFKD', input_str)
    return u"".join([c for c in nkfd_form if not unicodedata.combining(c)])

Difference between a View's Padding and Margin

In addition to all the correct answers above, one other difference is that padding increases the clickable area of a view, whereas margins do not. This is useful if you have a smallish clickable image but want to make the click handler forgiving.

For eg, see this image of my layout with an ImageView (the Android icon) where I set the paddingBotton to be 100dp (the image is the stock launcher mipmap ic_launcher). With the attached click handler I was able to click way outside and below the image and still register a click.

enter image description here

phpMyAdmin ERROR: mysqli_real_connect(): (HY000/1045): Access denied for user 'pma'@'localhost' (using password: NO)

This error is caused by a line of code in /usr/share/phpmyadmin/libraries/sql.lib.php.

It seems when I installed phpMyAdmin using apt, the version in the repository (phpMyAdmin v4.6.6) is not fully compatible with PHP 7.2. There is a newer version available on the official website (v4.8 as of writing), which fixes these compatibility issues with PHP 7.2.

You can download the latest version and install it manually or wait for the repositories to update with the newer version.

Alternatively, you can make a small change to sql.lib.php to fix the error.

Firstly, backup sql.lib.php before editing.

1-interminal:

sudo cp /usr/share/phpmyadmin/libraries/sql.lib.php /usr/share/phpmyadmin/libraries/sql.lib.php.bak

2-Edit sql.lib.php. Using vi:

sudo vi /usr/share/phpmyadmin/libraries/sql.lib.php

OR Using nano:

sudo nano /usr/share/phpmyadmin/libraries/sql.lib.php

Press CTRL + W (for nano) or ? (for vi/vim) and search for (count($analyzed_sql_results['select_expr'] == 1)

Replace it with ((count($analyzed_sql_results['select_expr']) == 1)

Save file and exit. (Press CTRL + X, press Y and then press ENTER for nano users / (for vi/vim) hit ESC then type :wq and press ENTER)

Java Array, Finding Duplicates

To check for duplicates you need to compare distinct pairs.

Angular 2 router.navigate

If the first segment doesn't start with / it is a relative route. router.navigate needs a relativeTo parameter for relative navigation

Either you make the route absolute:

this.router.navigate(['/foo-content', 'bar-contents', 'baz-content', 'page'], this.params.queryParams)

or you pass relativeTo

this.router.navigate(['../foo-content', 'bar-contents', 'baz-content', 'page'], {queryParams: this.params.queryParams, relativeTo: this.currentActivatedRoute})

See also

Using Jquery AJAX function with datatype HTML

var datos = $("#id_formulario").serialize();
$.ajax({         
    url: "url.php",      
    type: "POST",                   
    dataType: "html",                 
    data: datos,                 
    success: function (prueba) { 
        alert("funciona!");
    }//FIN SUCCES

});//FIN  AJAX

Vue.js : How to set a unique ID for each component instance?

Use this: this.$options._scopeId - is the same identifier used in 'style scoped' section:

this.$options._scopeId

How to get past the login page with Wget?

I wanted a one-liner that didn't download any files; here is an example of piping the cookie output into the next request. I only tested the following on Gentoo, but it should work in most *nix environments:

wget -q -O /dev/null --save-cookies /dev/stdout --post-data 'u=user&p=pass' 'http://example.com/login' | wget -q -O - --load-cookies /dev/stdin 'http://example.com/private/page'

(This is one line, though it likely wraps on your browser)

If you want the output saved to a file, change -O - to -O /some/file/name.ext

How to create a temporary table in SSIS control flow task and then use it in data flow task?

Solution:

Set the property RetainSameConnection on the Connection Manager to True so that temporary table created in one Control Flow task can be retained in another task.

Here is a sample SSIS package written in SSIS 2008 R2 that illustrates using temporary tables.

Walkthrough:

Create a stored procedure that will create a temporary table named ##tmpStateProvince and populate with few records. The sample SSIS package will first call the stored procedure and then will fetch the temporary table data to populate the records into another database table. The sample package will use the database named Sora Use the below create stored procedure script.

USE Sora;
GO

CREATE PROCEDURE dbo.PopulateTempTable
AS
BEGIN
    
    SET NOCOUNT ON;

    IF OBJECT_ID('TempDB..##tmpStateProvince') IS NOT NULL
        DROP TABLE ##tmpStateProvince;

    CREATE TABLE ##tmpStateProvince
    (
            CountryCode     nvarchar(3)         NOT NULL
        ,   StateCode       nvarchar(3)         NOT NULL
        ,   Name            nvarchar(30)        NOT NULL
    );

    INSERT INTO ##tmpStateProvince 
        (CountryCode, StateCode, Name)
    VALUES
        ('CA', 'AB', 'Alberta'),
        ('US', 'CA', 'California'),
        ('DE', 'HH', 'Hamburg'),
        ('FR', '86', 'Vienne'),
        ('AU', 'SA', 'South Australia'),
        ('VI', 'VI', 'Virgin Islands');
END
GO

Create a table named dbo.StateProvince that will be used as the destination table to populate the records from temporary table. Use the below create table script to create the destination table.

USE Sora;
GO

CREATE TABLE dbo.StateProvince
(
        StateProvinceID int IDENTITY(1,1)   NOT NULL
    ,   CountryCode     nvarchar(3)         NOT NULL
    ,   StateCode       nvarchar(3)         NOT NULL
    ,   Name            nvarchar(30)        NOT NULL
    CONSTRAINT [PK_StateProvinceID] PRIMARY KEY CLUSTERED
        ([StateProvinceID] ASC)
) ON [PRIMARY];
GO

Create an SSIS package using Business Intelligence Development Studio (BIDS). Right-click on the Connection Managers tab at the bottom of the package and click New OLE DB Connection... to create a new connection to access SQL Server 2008 R2 database.

Connection Managers - New OLE DB Connection

Click New... on Configure OLE DB Connection Manager.

Configure OLE DB Connection Manager - New

Perform the following actions on the Connection Manager dialog.

  • Select Native OLE DB\SQL Server Native Client 10.0 from Provider since the package will connect to SQL Server 2008 R2 database
  • Enter the Server name, like MACHINENAME\INSTANCE
  • Select Use Windows Authentication from Log on to the server section or whichever you prefer.
  • Select the database from Select or enter a database name, the sample uses the database name Sora.
  • Click Test Connection
  • Click OK on the Test connection succeeded message.
  • Click OK on Connection Manager

Connection Manager

The newly created data connection will appear on Configure OLE DB Connection Manager. Click OK.

Configure OLE DB Connection Manager - Created

OLE DB connection manager KIWI\SQLSERVER2008R2.Sora will appear under the Connection Manager tab at the bottom of the package. Right-click the connection manager and click Properties

Connection Manager Properties

Set the property RetainSameConnection on the connection KIWI\SQLSERVER2008R2.Sora to the value True.

RetainSameConnection Property on Connection Manager

Right-click anywhere inside the package and then click Variables to view the variables pane. Create the following variables.

  • A new variable named PopulateTempTable of data type String in the package scope SO_5631010 and set the variable with the value EXEC dbo.PopulateTempTable.

  • A new variable named FetchTempData of data type String in the package scope SO_5631010 and set the variable with the value SELECT CountryCode, StateCode, Name FROM ##tmpStateProvince

Variables

Drag and drop an Execute SQL Task on to the Control Flow tab. Double-click the Execute SQL Task to view the Execute SQL Task Editor.

On the General page of the Execute SQL Task Editor, perform the following actions.

  • Set the Name to Create and populate temp table
  • Set the Connection Type to OLE DB
  • Set the Connection to KIWI\SQLSERVER2008R2.Sora
  • Select Variable from SQLSourceType
  • Select User::PopulateTempTable from SourceVariable
  • Click OK

Execute SQL Task Editor

Drag and drop a Data Flow Task onto the Control Flow tab. Rename the Data Flow Task as Transfer temp data to database table. Connect the green arrow from the Execute SQL Task to the Data Flow Task.

Control Flow Tab

Double-click the Data Flow Task to switch to Data Flow tab. Drag and drop an OLE DB Source onto the Data Flow tab. Double-click OLE DB Source to view the OLE DB Source Editor.

On the Connection Manager page of the OLE DB Source Editor, perform the following actions.

  • Select KIWI\SQLSERVER2008R2.Sora from OLE DB Connection Manager
  • Select SQL command from variable from Data access mode
  • Select User::FetchTempData from Variable name
  • Click Columns page

OLE DB Source Editor - Connection Manager

Clicking Columns page on OLE DB Source Editor will display the following error because the table ##tmpStateProvince specified in the source command variable does not exist and SSIS is unable to read the column definition.

Error message

To fix the error, execute the statement EXEC dbo.PopulateTempTable using SQL Server Management Studio (SSMS) on the database Sora so that the stored procedure will create the temporary table. After executing the stored procedure, click Columns page on OLE DB Source Editor, you will see the column information. Click OK.

OLE DB Source Editor - Columns

Drag and drop OLE DB Destination onto the Data Flow tab. Connect the green arrow from OLE DB Source to OLE DB Destination. Double-click OLE DB Destination to open OLE DB Destination Editor.

On the Connection Manager page of the OLE DB Destination Editor, perform the following actions.

  • Select KIWI\SQLSERVER2008R2.Sora from OLE DB Connection Manager
  • Select Table or view - fast load from Data access mode
  • Select [dbo].[StateProvince] from Name of the table or the view
  • Click Mappings page

OLE DB Destination Editor - Connection Manager

Click Mappings page on the OLE DB Destination Editor would automatically map the columns if the input and output column names are same. Click OK. Column StateProvinceID does not have a matching input column and it is defined as an IDENTITY column in database. Hence, no mapping is required.

OLE DB Destination Editor - Mappings

Data Flow tab should look something like this after configuring all the components.

Data Flow tab

Click the OLE DB Source on Data Flow tab and press F4 to view Properties. Set the property ValidateExternalMetadata to False so that SSIS would not try to check for the existence of the temporary table during validation phase of the package execution.

Set ValidateExternalMetadata

Execute the query select * from dbo.StateProvince in the SQL Server Management Studio (SSMS) to find the number of rows in the table. It should be empty before executing the package.

Rows in table before package execution

Execute the package. Control Flow shows successful execution.

Package Execution  - Control Flow tab

In Data Flow tab, you will notice that the package successfully processed 6 rows. The stored procedure created early in this posted inserted 6 rows into the temporary table.

Package Execution  - Data Flow tab

Execute the query select * from dbo.StateProvince in the SQL Server Management Studio (SSMS) to find the 6 rows successfully inserted into the table. The data should match with rows founds in the stored procedure.

Rows in table after package execution

The above example illustrated how to create and use temporary table within a package.

Select All as default value for Multivalue parameter

Does not work if you have nulls.

You can get around this by modifying your select statement to plop something into nulls:

phonenumber = CASE
  WHEN (isnull(phonenumber, '')='') THEN '(blank)'
  ELSE phonenumber
END

What is the difference between Cygwin and MinGW?

Other answers already hit the target. I just want to add an illustration for a quick catch.

enter image description here

Wait .5 seconds before continuing code VB.net

Another way is to use System.Threading.ManualResetEvent

dim SecondsToWait as integer = 5
Dim Waiter As New ManualResetEvent(False)
Waiter.WaitOne(SecondsToWait * 1000) 'to get it into milliseconds

How to get jSON response into variable from a jquery script

Here's the script, rewritten to use the suggestions above and a change to your no-cache method.

<?php
// Simpler way of making sure all no-cache headers get sent
// and understood by all browsers, including IE.
session_cache_limiter('nocache');
header('Expires: ' . gmdate('r', 0));

header('Content-type: application/json');

// set to return response=error
$arr = array ('response'=>'error','comment'=>'test comment here');
echo json_encode($arr);
?>

//the script above returns this:
{"response":"error","comment":"test comment here"}

<script type="text/javascript">
$.ajax({
    type: "POST",
    url: "process.php",
    data: dataString,
    dataType: "json",
    success: function (data) {
        if (data.response == 'captcha') {
            alert('captcha');
        } else if (data.response == 'success') {
            alert('success');
        } else {
            alert('sorry there was an error');
        }
    }

}); // Semi-colons after all declarations, IE is picky on these things.
</script>

The main issue here was that you had a typo in the JSON you were returning ("resonse" instead of "response". This meant that you were looking for the wrong property in the JavaScript code. One way of catching these problems in the future is to console.log the value of data and make sure the property you are looking for is there.

Learning how to use the Chrome debugger tools (or similar tools in Firefox/Safari/Opera/etc.) will also be invaluable.

Now() function with time trim

DateValue(CStr(Now()))

That's the best I've found. If you have the date as a string already you can just do:

DateValue("12/04/2012 04:56:15")

or

DateValue(*DateStringHere*)

Hope this helps someone...

Short description of the scoping rules?

The Python name resolution only knows the following kinds of scope:

  1. builtins scope which provides the Builtin Functions, such as print, int, or zip,
  2. module global scope which is always the top-level of the current module,
  3. three user-defined scopes that can be nested into each other, namely
    1. function closure scope, from any enclosing def block, lambda expression or comprehension.
    2. function local scope, inside a def block, lambda expression or comprehension,
    3. class scope, inside a class block.

Notably, other constructs such as if, for, or with statements do not have their own scope.

The scoping TLDR: The lookup of a name begins at the scope in which the name is used, then any enclosing scopes (excluding class scopes), to the module globals, and finally the builtins – the first match in this search order is used. The assignment to a scope is by default to the current scope – the special forms nonlocal and global must be used to assign to a name from an outer scope.

Finally, comprehensions and generator expressions as well as := asignment expressions have one special rule when combined.


Nested Scopes and Name Resolution

These different scopes build a hierarchy, with builtins then global always forming the base, and closures, locals and class scope being nested as lexically defined. That is, only the nesting in the source code matters, not for example the call stack.

print("builtins are available without definition")

some_global = "1"  # global variables are at module scope

def outer_function():
    some_closure = "3.1"  # locals and closure are defined the same, at function scope
    some_local = "3.2"    # a variable becomes a closure if a nested scope uses it

    class InnerClass:
         some_classvar = "3.3"   # class variables exist *only* at class scope

         def nested_function(self):
             some_local = "3.2"   # locals can replace outer names
             print(some_closure)  # closures are always readable
    return InnerClass

Even though class creates a scope and may have nested classes, functions and comprehensions, the names of the class scope are not visible to enclosed scopes. This creates the following hierarchy:

? builtins           [print, ...]
??? globals            [some_global]
  ??? outer_function     [some_local, some_closure]
    ??? InnerClass         [some_classvar]
    ??? inner_function     [some_local]

Name resolution always starts at the current scope in which a name is accessed, then goes up the hierarchy until a match is found. For example, looking up some_local inside outer_function and inner_function starts at the respective function - and immediately finds the some_local defined in outer_function and inner_function, respectively. When a name is not local, it is fetched from the nearest enclosing scope that defines it – looking up some_closure and print inside inner_function searches until outer_function and builtins, respectively.


Scope Declarations and Name Binding

By default, a name belongs to any scope in which it is bound to a value. Binding the same name again in an inner scope creates a new variable with the same name - for example, some_local exists separately in both outer_function and inner_function. As far as scoping is concerned, binding includes any statement that sets the value of a name – assignment statements, but also the iteration variable of a for loop, or the name of a with context manager. Notably, del also counts as name binding.

When a name must refer to an outer variable and be bound in an inner scope, the name must be declared as not local. Separate declarations exists for the different kinds of enclosing scopes: nonlocal always refers to the nearest closure, and global always refers to a global name. Notably, nonlocal never refers to a global name and global ignores all closures of the same name. There is no declaration to refer to the builtin scope.


some_global = "1"

def outer_function():
    some_closure = "3.2"
    some_global = "this is ignored by a nested global declaration"
    
    def inner_function():
        global some_global     # declare variable from global scope
        nonlocal some_closure  # declare variable from enclosing scope
        message = " bound by an inner scope"
        some_global = some_global + message
        some_closure = some_closure + message
    return inner_function

Of note is that function local and nonlocal are resolved at compile time. A nonlocal name must exist in some outer scope. In contrast, a global name can be defined dynamically and may be added or removed from the global scope at any time.


Comprehensions and Assignment Expressions

The scoping rules of list, set and dict comprehensions and generator expressions are almost the same as for functions. Likewise, the scoping rules for assignment expressions are almost the same as for regular name binding.

The scope of comprehensions and generator expressions is of the same kind as function scope. All names bound in the scope, namely the iteration variables, are locals or closures to the comprehensions/generator and nested scopes. All names, including iterables, are resolved using name resolution as applicable inside functions.

some_global = "global"

def outer_function():
    some_closure = "closure"
    return [            # new function-like scope started by comprehension
        comp_local      # names resolved using regular name resolution
        for comp_local  # iteration targets are local
        in "iterable"
        if comp_local in some_global and comp_local in some_global
    ]

An := assignment expression works on the nearest function, class or global scope. Notably, if the target of an assignment expression has been declared nonlocal or global in the nearest scope, the assignment expression honors this like a regular assignment.

print(some_global := "global")

def outer_function():
    print(some_closure := "closure")

However, an assignment expression inside a comprehension/generator works on the nearest enclosing scope of the comprehension/generator, not the scope of the comprehension/generator itself. When several comprehensions/generators are nested, the nearest function or global scope is used. Since the comprehension/generator scope can read closures and global variables, the assignment variable is readable in the comprehension as well. Assigning from a comprehension to a class scope is not valid.

print(some_global := "global")

def outer_function():
    print(some_closure := "closure")
    steps = [
        # v write to variable in containing scope
        (some_closure := some_closure + comp_local)
        #                 ^ read from variable in containing scope
        for comp_local in some_global
    ]
    return some_closure, steps

While the iteration variable is local to the comprehension in which it is bound, the target of the assignment expression does not create a local variable and is read from the outer scope:

? builtins           [print, ...]
??? globals            [some_global]
  ??? outer_function     [some_closure]
    ??? <listcomp>         [comp_local]

Adding class to element using Angular JS

For Angular 7 users:

Here I show you that you can activate or deactivate a simple class attribute named "blurred" with just a boolean. Therefore u need to use [ngClass].

TS class

blurredStatus = true

HTML

<div class="inner-wrapper" [ngClass]="{'blurred':blurredStatus}"></div>

What is the difference between exit(0) and exit(1) in C?

exit(0) indicates that the program terminated without errors. exit(1) indicates that there were an error.

You can use different values other than 1 to differentiate between different kind of errors.

How do I center this form in css?

Another solution (without a wrapper) would be to set the form to display: table, which would make it act like a table so it would have the width of its largest child, and then apply margin: 0 auto to center it.

form {
    display: table;
    margin: 0 auto;
}

Credit goes to: https://stackoverflow.com/a/49378738/7841955

How can I set the request header for curl?

Just use the -H parameter several times:

curl -H "Accept-Charset: utf-8" -H "Content-Type: application/x-www-form-urlencoded" http://www.some-domain.com

Most efficient way to create a zero filled JavaScript array?

Recursive solutions

As noted by several others, utilizing .concat() generally provides fast solutions. Here is a simple recursive solution:

_x000D_
_x000D_
function zeroFill(len, a){_x000D_
  return len <= (a || (a = [0])).length ?_x000D_
    a.slice(0, len) :_x000D_
    zeroFill(len, a.concat(a))_x000D_
}_x000D_
_x000D_
console.log(zeroFill(5));
_x000D_
_x000D_
_x000D_

And a general-purpose recursive array fill function:

_x000D_
_x000D_
function fill(len, v){_x000D_
  return len <= (v = [].concat(v, v)).length ?_x000D_
    v.slice(0, len) : fill(len, v)_x000D_
}_x000D_
_x000D_
console.log(fill(5, 'abc'));
_x000D_
_x000D_
_x000D_

Disable Copy or Paste action for text box?

Try This

 $( "#email,#confirmEmail " ).on( "copy cut paste drop", function() {
                return false;
        });

How to get Database Name from Connection String using SqlConnectionStringBuilder

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

Bulk Insertion in Laravel using eloquent ORM

We can update GTF answer to update timestamps easily

$data = array(
    array(
        'name'=>'Coder 1', 'rep'=>'4096',
        'created_at'=>date('Y-m-d H:i:s'),
        'modified_at'=> date('Y-m-d H:i:s')
       ),
    array(
         'name'=>'Coder 2', 'rep'=>'2048',
         'created_at'=>date('Y-m-d H:i:s'),
         'modified_at'=> date('Y-m-d H:i:s')
       ),
    //...
);

Coder::insert($data);

Update: to simplify the date we can use carbon as @Pedro Moreira suggested

$now = Carbon::now('utc')->toDateTimeString();
$data = array(
    array(
        'name'=>'Coder 1', 'rep'=>'4096',
        'created_at'=> $now,
        'modified_at'=> $now
       ),
    array(
         'name'=>'Coder 2', 'rep'=>'2048',
         'created_at'=> $now,
         'modified_at'=> $now
       ),
    //...
);

Coder::insert($data);

UPDATE2: for laravel 5 , use updated_at instead of modified_at

$now = Carbon::now('utc')->toDateTimeString();
$data = array(
    array(
        'name'=>'Coder 1', 'rep'=>'4096',
        'created_at'=> $now,
        'updated_at'=> $now
       ),
    array(
         'name'=>'Coder 2', 'rep'=>'2048',
         'created_at'=> $now,
         'updated_at'=> $now
       ),
    //...
);

Coder::insert($data);

Convert an integer to a byte array

I agree with Brainstorm's approach: assuming that you're passing a machine-friendly binary representation, use the encoding/binary library. The OP suggests that binary.Write() might have some overhead. Looking at the source for the implementation of Write(), I see that it does some runtime decisions for maximum flexibility.

func Write(w io.Writer, order ByteOrder, data interface{}) error {
    // Fast path for basic types.
    var b [8]byte
    var bs []byte
    switch v := data.(type) {
    case *int8:
        bs = b[:1]
        b[0] = byte(*v)
    case int8:
        bs = b[:1]
        b[0] = byte(v)
    case *uint8:
        bs = b[:1]
        b[0] = *v
    ...

Right? Write() takes in a very generic data third argument, and that's imposing some overhead as the Go runtime then is forced into encoding type information. Since Write() is doing some runtime decisions here that you simply don't need in your situation, maybe you can just directly call the encoding functions and see if it performs better.

Something like this:

package main

import (
    "encoding/binary"
    "fmt"
)

func main() {
    bs := make([]byte, 4)
    binary.LittleEndian.PutUint32(bs, 31415926)
    fmt.Println(bs)
}

Let us know how this performs.

Otherwise, if you're just trying to get an ASCII representation of the integer, you can get the string representation (probably with strconv.Itoa) and cast that string to the []byte type.

package main

import (
    "fmt"
    "strconv"
)

func main() {
    bs := []byte(strconv.Itoa(31415926))
    fmt.Println(bs)
}

How to Make A Chevron Arrow Using CSS?

> itself is very wonderful arrow! Just prepend a div with it and style it.

_x000D_
_x000D_
div{_x000D_
  font-size:50px;_x000D_
}_x000D_
div::before{_x000D_
  content:">";_x000D_
  font: 50px 'Consolas';_x000D_
  font-weight:900;_x000D_
}
_x000D_
<div class="arrowed">Hatz!</div>
_x000D_
_x000D_
_x000D_

Why does cURL return error "(23) Failed writing body"?

So it was a problem of encoding. Iconv solves the problem

curl 'http://www.multitran.ru/c/m.exe?CL=1&s=hello&l1=1' | iconv -f windows-1251 | tr -dc '[:print:]' | ...

TSQL CASE with if comparison in SELECT statement

Please select the same in the outer select. You can't access the alias name in the same query.

SELECT *, (CASE
        WHEN articleNumber < 2 THEN 'Ama'
        WHEN articleNumber < 5 THEN 'SemiAma' 
        WHEN articleNumber < 7 THEN 'Good'  
        WHEN articleNumber < 9 THEN 'Better' 
        WHEN articleNumber < 12 THEN 'Best'
        ELSE 'Outstanding'
        END) AS ranking 
FROM(
    SELECT registrationDate, (SELECT COUNT(*) FROM Articles WHERE Articles.userId = Users.userId) as articleNumber, 
    hobbies, etc...
    FROM USERS
)x

What is the difference between os.path.basename() and os.path.dirname()?

To summarize what was mentioned by Breno above

Say you have a variable with a path to a file

path = '/home/User/Desktop/myfile.py'

os.path.basename(path) returns the string 'myfile.py'

and

os.path.dirname(path) returns the string '/home/User/Desktop' (without a trailing slash '/')

These functions are used when you have to get the filename/directory name given a full path name.

In case the file path is just the file name (e.g. instead of path = '/home/User/Desktop/myfile.py' you just have myfile.py), os.path.dirname(path) returns an empty string.

How to increase an array's length

Arrays in Java are of fixed size that is specified when they are declared. To increase the size of the array you have to create a new array with a larger size and copy all of the old values into the new array.

ex:

char[] copyFrom  = { 'a', 'b', 'c', 'd', 'e' };
char[] copyTo    = new char[7];

System.out.println(Arrays.toString(copyFrom));
System.arraycopy(copyFrom, 0, copyTo, 0, copyFrom.length);
System.out.println(Arrays.toString(copyTo));

Alternatively you could use a dynamic data structure like a List.

mongo - couldn't connect to server 127.0.0.1:27017

I also have the same problem then I got fixed by these two lines of code. Hope, it helps

systemctl start mongod
systemctl enable mongod

Excel Macro : How can I get the timestamp in "yyyy-MM-dd hh:mm:ss" format?

DateTime.Now returns a value of data type Date. Date variables display dates according to the short date format and time format set on your computer.

They may be formatted as a string for display in any valid date format by the Format function as mentioned in aother answers

Format(DateTime.Now, "yyyy-MM-dd hh:mm:ss")

CSS - Make divs align horizontally

Float: left, display: inline-block will both fail to align the elements horizontally if they exceed the width of the container.

It's important to note that the container should not wrap if the elements MUST display horizontally: white-space: nowrap

Numpy first occurrence of value greater than existing value

I was also interested in this and I've compared all the suggested answers with perfplot. (Disclaimer: I'm the author of perfplot.)

If you know that the array you're looking through is already sorted, then

numpy.searchsorted(a, alpha)

is for you. It's O(log(n)) operation, i.e., the speed hardly depends on the size of the array. You can't get faster than that.

If you don't know anything about your array, you're not going wrong with

numpy.argmax(a > alpha)

Already sorted:

enter image description here

Unsorted:

enter image description here

Code to reproduce the plot:

import numpy
import perfplot


alpha = 0.5
numpy.random.seed(0)


def argmax(data):
    return numpy.argmax(data > alpha)


def where(data):
    return numpy.where(data > alpha)[0][0]


def nonzero(data):
    return numpy.nonzero(data > alpha)[0][0]


def searchsorted(data):
    return numpy.searchsorted(data, alpha)


perfplot.save(
    "out.png",
    # setup=numpy.random.rand,
    setup=lambda n: numpy.sort(numpy.random.rand(n)),
    kernels=[argmax, where, nonzero, searchsorted],
    n_range=[2 ** k for k in range(2, 23)],
    xlabel="len(array)",
)

psql: server closed the connection unexepectedly

Solved by setting a password for the user first.

In terminal

sudo -u <username> psql

ALTER USER <username> PASSWORD 'SetPassword';
# ALTER ROLE

\q

In pgAdmin

**Connection**

Host name/address: 127.0.0.1
Port: 5432
Maintenance database: postgres
username: postgres
password: XXXXXX

Export javascript data to CSV file without server interaction

There's always the HTML5 download attribute :

This attribute, if present, indicates that the author intends the hyperlink to be used for downloading a resource so that when the user clicks on the link they will be prompted to save it as a local file.

If the attribute has a value, the value will be used as the pre-filled file name in the Save prompt that opens when the user clicks on the link.

var A = [['n','sqrt(n)']];

for(var j=1; j<10; ++j){ 
    A.push([j, Math.sqrt(j)]);
}

var csvRows = [];

for(var i=0, l=A.length; i<l; ++i){
    csvRows.push(A[i].join(','));
}

var csvString = csvRows.join("%0A");
var a         = document.createElement('a');
a.href        = 'data:attachment/csv,' +  encodeURIComponent(csvString);
a.target      = '_blank';
a.download    = 'myFile.csv';

document.body.appendChild(a);
a.click();

FIDDLE

Tested in Chrome and Firefox, works fine in the newest versions (as of July 2013).
Works in Opera as well, but does not set the filename (as of July 2013).
Does not seem to work in IE9 (big suprise) (as of July 2013).

An overview over what browsers support the download attribute can be found Here
For non-supporting browsers, one has to set the appropriate headers on the serverside.


Apparently there is a hack for IE10 and IE11, which doesn't support the download attribute (Edge does however).

var A = [['n','sqrt(n)']];

for(var j=1; j<10; ++j){ 
    A.push([j, Math.sqrt(j)]);
}

var csvRows = [];

for(var i=0, l=A.length; i<l; ++i){
    csvRows.push(A[i].join(','));
}

var csvString = csvRows.join("%0A");

if (window.navigator.msSaveOrOpenBlob) {
    var blob = new Blob([csvString]);
    window.navigator.msSaveOrOpenBlob(blob, 'myFile.csv');
} else {
    var a         = document.createElement('a');
    a.href        = 'data:attachment/csv,' +  encodeURIComponent(csvString);
    a.target      = '_blank';
    a.download    = 'myFile.csv';
    document.body.appendChild(a);
    a.click();
}

Determine if variable is defined in Python

try:
    a # does a exist in the current namespace
except NameError:
    a = 10 # nope

Change primary key column in SQL Server

Assuming that your current primary key constraint is called pk_history, you can replace the following lines:

ALTER TABLE history ADD PRIMARY KEY (id)

ALTER TABLE history
DROP CONSTRAINT userId
DROP CONSTRAINT name

with these:

ALTER TABLE history DROP CONSTRAINT pk_history

ALTER TABLE history ADD CONSTRAINT pk_history PRIMARY KEY (id)

If you don't know what the name of the PK is, you can find it with the following query:

SELECT * 
  FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS 
 WHERE TABLE_NAME = 'history'

CSS Margin: 0 is not setting to 0

After reading this and troubleshooting the same issues, I agree that it is related to headings (h1 for sure, havent played with any others), also browser styles adding margins and paddings with clever rules that are hard to find and over-ride.

I have adapted a technique used to apply the box-sizing property properly to margins and paddings. the original article for box-sizing is located at CSS-Tricks :

html {
margin: 0;
padding: 0;
}
*, *:before, *:after {
margin: inherit;
padding: inherit;
}

So far it is exactly the trick for not using complex resets and makes applying a design much easier for myself anyways. Hope it helps.