Could not load file or assembly System.Web.Http.WebHost after published to Azure web site

I was missing several DLLs. Even if I manually copied them to the directory the next time I published they would disappear. Each one was already set to Copy Locally in VS. The fix for me was to set each one to Copy Locally false, save, build then set each one to copy locally true. This time when I published all of the DLLs published correctly. Strange

What is Haskell used for in the real world?

From Haskell:

Haskell is a standardized, general-purpose purely functional programming language, with non-strict semantics and strong static typing. It is named after logician Haskell Curry.

Basically Haskell can be used to create pretty much anything you would normally create using other general-purpose languages (e.g. C#, Java, C, C++, etc.).

How to set Oracle's Java as the default Java in Ubuntu?

If you're doing any sort of development you need to point to the JDK (Java Development Kit). Otherwise, you can point to the JRE (Java Runtime Environment).

The JDK contains everything the JRE has and more. If you're just executing Java programs, you can point to either the JRE or the JDK.

You should set JAVA_HOME based on current Java you are using. readlink will print value of a symbolic link for current Java and sed will adjust it to JRE directory:

export JAVA_HOME=$(readlink -f /usr/bin/java | sed "s:bin/java::")

If you want to set up JAVA_HOME to JDK you should go up one folder more:

export JAVA_HOME=$(readlink -f /usr/bin/java | sed "s:jre/bin/java::")

Parse error: Syntax error, unexpected end of file in my PHP code

You can't divide IF/ELSE instructions into two separate blocks. If you need HTML code to be printed, use echo.

<html>
    <?php
        function login()
        {
            // Login function code
        }
        if (login())
        {
            echo "<h2>Welcome Administrator</h2>
            <a href=\"upload.php\">Upload Files</a>
            <br />
            <a href=\"points.php\">Edit Points Tally</a>";
        }
        else
        {
            echo "Incorrect login details. Please login";
        }
    ?>
    Some more HTML code
</html>

Android Gradle 5.0 Update:Cause: org.jetbrains.plugins.gradle.tooling.util

Issue has been resolved after updating Android studio version to 3.3-rc2 or latest released version.

cr: @shadowsheep

have to change version under /gradle/wrapper/gradle-wrapper.properties. refer below url https://stackoverflow.com/a/56412795/7532946

Change table header color using bootstrap

Try This:

table.table tr th{background-color:blue !important; font-color:white !important;}

hope this helps..

JavaScript: Upload file

Pure JS

You can use fetch optionally with await-try-catch

let photo = document.getElementById("image-file").files[0];
let formData = new FormData();
     
formData.append("photo", photo);
fetch('/upload/image', {method: "POST", body: formData});

_x000D_

async function SavePhoto(inp) 
{
    let user = { name:'john', age:34 };
    let formData = new FormData();
    let photo = inp.files[0];      
         
    formData.append("photo", photo);
    formData.append("user", JSON.stringify(user)); 
    
    const ctrl = new AbortController()    // timeout
    setTimeout(() => ctrl.abort(), 5000);
    
    try {
       let r = await fetch('/upload/image', 
         {method: "POST", body: formData, signal: ctrl.signal}); 
       console.log('HTTP response code:',r.status); 
    } catch(e) {
       console.log('Huston we have problem...:', e);
    }
    
}

_x000D_

<input id="image-file" type="file" onchange="SavePhoto(this)" >
<br><br>
Before selecting the file open chrome console > network tab to see the request details.
<br><br>
<small>Because in this example we send request to https://stacksnippets.net/upload/image the response code will be 404 ofcourse...</small>

<br><br>
(in stack overflow snippets there is problem with error handling, however in <a href="https://jsfiddle.net/Lamik/b8ed5x3y/5/">jsfiddle version</a> for 404 errors 4xx/5xx are <a href="https://stackoverflow.com/a/33355142/860099">not throwing</a> at all but we can read response status which contains code)

_x000D_

Old school approach - xhr

let photo = document.getElementById("image-file").files[0];  // file from input
let req = new XMLHttpRequest();
let formData = new FormData();

formData.append("photo", photo);                                
req.open("POST", '/upload/image');
req.send(formData);

_x000D_

function SavePhoto(e) 
{
    let user = { name:'john', age:34 };
    let xhr = new XMLHttpRequest();
    let formData = new FormData();
    let photo = e.files[0];      
    
    formData.append("user", JSON.stringify(user));   
    formData.append("photo", photo);
    
    xhr.onreadystatechange = state => { console.log(xhr.status); } // err handling
    xhr.timeout = 5000;
    xhr.open("POST", '/upload/image'); 
    xhr.send(formData);
}

_x000D_

<input id="image-file" type="file" onchange="SavePhoto(this)" >
<br><br>
Choose file and open chrome console > network tab to see the request details.
<br><br>
<small>Because in this example we send request to https://stacksnippets.net/upload/image the response code will be 404 ofcourse...</small>

<br><br>
(the stack overflow snippets, has some problem with error handling - the xhr.status is zero (instead of 404) which is similar to situation when we run script from file on <a href="https://stackoverflow.com/a/10173639/860099">local disc</a> - so I provide also js fiddle version which shows proper http error code <a href="https://jsfiddle.net/Lamik/k6jtq3uh/2/">here</a>)

_x000D_

SUMMARY

In server side you can read original file name (and other info) which is automatically included to request by browser in filename formData parameter.
You do NOT need to set request header Content-Type to multipart/form-data - this will be set automatically by browser.
Instead of /upload/image you can use full address like http://.../upload/image.
If you want to send many files in single request use multiple attribute: <input multiple type=... />, and attach all chosen files to formData in similar way (e.g. photo2=...files[2];... formData.append("photo2", photo2);)
You can include additional data (json) to request e.g. let user = {name:'john', age:34} in this way: formData.append("user", JSON.stringify(user));
You can set timeout: for fetch using AbortController, for old approach by xhr.timeout= milisec
This solutions should work on all major browsers.

MySQL Delete all rows from table and reset ID to zero

if you want to use truncate use this:

SET FOREIGN_KEY_CHECKS = 0; 
TRUNCATE table $table_name; 
SET FOREIGN_KEY_CHECKS = 1;

How do I export (and then import) a Subversion repository?

You can also use the svnadmin hotcopy command:

svnadmin hotcopy OLD_REPOS_PATH NEW_REPOS_PATH

It takes a full backup from repository, including all hooks, configuration files, etc.

More at SVN Book

Convert string to int array using LINQ

You can shorten JSprangs solution a bit by using a method group instead:

string s1 = "1;2;3;4;5;6;7;8;9;10;11;12";
int[] ints = s1.Split(';').Select(int.Parse).ToArray();

Syncing Android Studio project with Gradle files

EDIT

Starting with Android Studio 3.1, you should go to:

File -> Sync Project with Gradle Files

OLD

Clicking the button 'Sync Project With Gradle Files' should do the trick:

Tools -> Android -> Sync Project with Gradle Files

If that fails, try running 'Rebuild project':

Build -> Rebuild Project

How do you extract a JAR in a UNIX filesystem with a single command and specify its target directory using the JAR command?

If this is a personal script, rather than one you're planning on distributing, it might be simpler to write a shell function for this:

function warextract { jar xf $1 $2 && mv $2 $3 }

which you could then call from python like so:

warextract /home/foo/bar/Portal.ear Binaries.war /home/foo/bar/baz/

If you really feel like it, you could use sed to parse out the filename from the path, so that you'd be able to call it with

warextract /home/foo/bar/Portal.ear /home/foo/bar/baz/Binaries.war

I'll leave that as an excercise to the reader, though.

Of course, since this will extract the .war out into the current directory first, and then move it, it has the possibility of overwriting something with the same name where you are.

Changing directory, extracting it, and cd-ing back is a bit cleaner, but I find myself using little one-line shell functions like this all the time when I want to reduce code clutter.

Does the 'mutable' keyword have any purpose other than allowing the variable to be modified by a const function?

mutable does exist as you infer to allow one to modify data in an otherwise constant function.

The intent is that you might have a function that "does nothing" to the internal state of the object, and so you mark the function const, but you might really need to modify some of the objects state in ways that don't affect its correct functionality.

The keyword may act as a hint to the compiler -- a theoretical compiler could place a constant object (such as a global) in memory that was marked read-only. The presence of mutable hints that this should not be done.

Here are some valid reasons to declare and use mutable data:

Thread safety. Declaring a mutable boost::mutex is perfectly reasonable.
Statistics. Counting the number of calls to a function, given some or all of its arguments.
Memoization. Computing some expensive answer, and then storing it for future reference rather than recomputing it again.

REST response code for invalid data

It is amusing to return 418 I'm a teapot to requests that are obviously crafted or malicious and "can't happen", such as failing CSRF check or missing request properties.

2.3.2 418 I'm a teapot

Any attempt to brew coffee with a teapot should result in the error code "418 I'm a teapot". The resulting entity body MAY be short and stout.

To keep it reasonably serious, I restrict usage of funny error codes to RESTful endpoints that are not directly exposed to the user.

Adding the "Clear" Button to an iPhone UITextField

This button is a built-in overlay that is provided by the UITextField class, but as of the iOS 2.2 SDK, there isn't any way to set it via Interface Builder. You have to enable it programmatically.

Add this line of code somewhere (viewDidLoad, for example):

Objective-C

myUITextField.clearButtonMode = UITextFieldViewModeWhileEditing;

Swift 5.0

myUITextField.clearButtonMode = .whileEditing

Circle-Rectangle collision detection (intersection)

Works, just figured this out a week ago, and just now got to testing it.

double theta = Math.atan2(cir.getX()-sqr.getX()*1.0,
                          cir.getY()-sqr.getY()*1.0); //radians of the angle
double dBox; //distance from box to edge of box in direction of the circle

if((theta >  Math.PI/4 && theta <  3*Math.PI / 4) ||
   (theta < -Math.PI/4 && theta > -3*Math.PI / 4)) {
    dBox = sqr.getS() / (2*Math.sin(theta));
} else {
    dBox = sqr.getS() / (2*Math.cos(theta));
}
boolean touching = (Math.abs(dBox) >=
                    Math.sqrt(Math.pow(sqr.getX()-cir.getX(), 2) +
                              Math.pow(sqr.getY()-cir.getY(), 2)));

Pass a data.frame column name to a function

If you are trying to build this function within an R package or simply want to reduce complexity, you can do the following:

test_func <- function(df, column) {
  if (column %in% colnames(df)) {
    return(max(df[, column, with=FALSE])) 
  } else {
    stop(cat(column, "not in data.frame columns."))
  }
}

The argument with=FALSE "disables the ability to refer to columns as if they are variables, thereby restoring the “data.frame mode” (per CRAN documentation). The if statement is a quick way to catch if the column name provided is within the data.frame. Could also use tryCatch error handling here.

Python 2: AttributeError: 'list' object has no attribute 'strip'

strip() is a method for strings, you are calling it on a list, hence the error.

>>> 'strip' in dir(str)
True
>>> 'strip' in dir(list)
False

To do what you want, just do

>>> l = ['Facebook;Google+;MySpace', 'Apple;Android']
>>> l1 = [elem.strip().split(';') for elem in l]
>>> print l1
[['Facebook', 'Google+', 'MySpace'], ['Apple', 'Android']]

Since, you want the elements to be in a single list (and not a list of lists), you have two options.

Create an empty list and append elements to it.
Flatten the list.

To do the first, follow the code:

>>> l1 = []
>>> for elem in l:
        l1.extend(elem.strip().split(';'))  
>>> l1
['Facebook', 'Google+', 'MySpace', 'Apple', 'Android']

To do the second, use itertools.chain

>>> l1 = [elem.strip().split(';') for elem in l]
>>> print l1
[['Facebook', 'Google+', 'MySpace'], ['Apple', 'Android']]
>>> from itertools import chain
>>> list(chain(*l1))
['Facebook', 'Google+', 'MySpace', 'Apple', 'Android']

ORA-06502: PL/SQL: numeric or value error: character string buffer too small

PL/SQL: numeric or value error: character string buffer too small

is due to the fact that you declare a string to be of a fixed length (say 20), and at some point in your code you assign it a value whose length exceeds what you declared.

for example:

myString VARCHAR2(20);
myString :='abcdefghijklmnopqrstuvwxyz'; --length 26

will fire such an error

How to equalize the scales of x-axis and y-axis in Python matplotlib?

See the documentation on plt.axis(). This:

plt.axis('equal')

doesn't work because it changes the limits of the axis to make circles appear circular. What you want is:

plt.axis('square')

This creates a square plot with equal axes.

How to Clear Console in Java?

If your terminal supports ANSI escape codes, this clears the screen and moves the cursor to the first row, first column:

System.out.print("\033[H\033[2J");
System.out.flush();

This works on almost all UNIX terminals and terminal emulators. The Windows cmd.exe does not interprete ANSI escape codes.

Real time data graphing on a line chart with html5

You get the data from server, update your previously available datasetand then probably use one of the freely available libraries to draw the graph (eg: http://www.rgraph.net)

Things you might want to considering : If your chart is represents a state , get only the new data with xhr , update data on client and draw .

Docker: Multiple Dockerfiles in project

In newer versions(>=1.8.0) of docker, you can do this

docker build -f Dockerfile.db .
docker build -f Dockerfile.web .

A big save.

EDIT: update versions per raksja's comment

EDIT: comment from @vsevolod: it's possible to get syntax highlighting in VS code by giving files .Dockerfile extension(instead of name) e.g. Prod.Dockerfile, Test.Dockerfile etc.

UnicodeDecodeError, invalid continuation byte

Because UTF-8 is multibyte and there is no char corresponding to your combination of \xe9 plus following space.

Why should it succeed in both utf-8 and latin-1?

Here how the same sentence should be in utf-8:

>>> o.decode('latin-1').encode("utf-8")
'a test of \xc3\xa9 char'

How do I solve this error, "error while trying to deserialize parameter"

In our case the problem was that we change the default root namespace name.

Project Configuration screen

This is the Project Configuration screen

We finally decided to back to the original name and the problem was solved.

The problem actually was the dots in the Root namespace. With two dots (Name.Child.Child) it doesnt work. But with one (Name.ChidChild) works.

How do you refresh the MySQL configuration file without restarting?

You were so close! The kill -HUP method wasn't working for me either.

You were calling:

select @@global.max_connections;

All you needed was to set instead of select:

set @@global.max_connections = 400;

See:

http://www.netadmintools.com/art573.html

http://www.electrictoolbox.com/update-max-connections-mysql/

Running multiple async tasks and waiting for them all to complete

Both answers didn't mention the awaitable Task.WhenAll:

var task1 = DoWorkAsync();
var task2 = DoMoreWorkAsync();

await Task.WhenAll(task1, task2);

The main difference between Task.WaitAll and Task.WhenAll is that the former will block (similar to using Wait on a single task) while the latter will not and can be awaited, yielding control back to the caller until all tasks finish.

More so, exception handling differs:

Task.WaitAll:

At least one of the Task instances was canceled -or- an exception was thrown during the execution of at least one of the Task instances. If a task was canceled, the AggregateException contains an OperationCanceledException in its InnerExceptions collection.

Task.WhenAll:

If any of the supplied tasks completes in a faulted state, the returned task will also complete in a Faulted state, where its exceptions will contain the aggregation of the set of unwrapped exceptions from each of the supplied tasks.

If none of the supplied tasks faulted but at least one of them was canceled, the returned task will end in the Canceled state.

If none of the tasks faulted and none of the tasks were canceled, the resulting task will end in the RanToCompletion state. If the supplied array/enumerable contains no tasks, the returned task will immediately transition to a RanToCompletion state before it's returned to the caller.

Multiple models in a view

I'd recommend using Html.RenderAction and PartialViewResults to accomplish this; it will allow you to display the same data, but each partial view would still have a single view model and removes the need for a BigViewModel

So your view contain something like the following:

@Html.RenderAction("Login")
@Html.RenderAction("Register")

Where Login & Register are both actions in your controller defined like the following:

public PartialViewResult Login( )
{
    return PartialView( "Login", new LoginViewModel() );
}

public PartialViewResult Register( )
{
    return PartialView( "Register", new RegisterViewModel() );
}

The Login & Register would then be user controls residing in either the current View folder, or in the Shared folder and would like something like this:

/Views/Shared/Login.cshtml: (or /Views/MyView/Login.cshtml)

@model LoginViewModel
@using (Html.BeginForm("Login", "Auth", FormMethod.Post))
{
    @Html.TextBoxFor(model => model.Email)
    @Html.PasswordFor(model => model.Password)
}

/Views/Shared/Register.cshtml: (or /Views/MyView/Register.cshtml)

@model ViewModel.RegisterViewModel
@using (Html.BeginForm("Login", "Auth", FormMethod.Post))
{
    @Html.TextBoxFor(model => model.Name)
    @Html.TextBoxFor(model => model.Email)
    @Html.PasswordFor(model => model.Password)
}

And there you have a single controller action, view and view file for each action with each totally distinct and not reliant upon one another for anything.

Converting Java file:// URL to File(...) path, platform independent, including UNC paths

Based on the hint and link provided in Simone Giannis answer, this is my hack to fix this.

I am testing on uri.getAuthority(), because UNC path will report an Authority. This is a bug - so I rely on the existence of a bug, which is evil, but it apears as if this will stay forever (since Java 7 solves the problem in java.nio.Paths).

Note: In my context I will receive absolute paths. I have tested this on Windows and OS X.

(Still looking for a better way to do it)

package com.christianfries.test;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;

public class UNCPathTest {

    public static void main(String[] args) throws MalformedURLException, URISyntaxException {
        UNCPathTest upt = new UNCPathTest();

        upt.testURL("file://server/dir/file.txt");  // Windows UNC Path

        upt.testURL("file:///Z:/dir/file.txt");     // Windows drive letter path

        upt.testURL("file:///dir/file.txt");        // Unix (absolute) path
    }

    private void testURL(String urlString) throws MalformedURLException, URISyntaxException {
        URL url = new URL(urlString);
        System.out.println("URL is: " + url.toString());

        URI uri = url.toURI();
        System.out.println("URI is: " + uri.toString());

        if(uri.getAuthority() != null && uri.getAuthority().length() > 0) {
            // Hack for UNC Path
            uri = (new URL("file://" + urlString.substring("file:".length()))).toURI();
        }

        File file = new File(uri);
        System.out.println("File is: " + file.toString());

        String parent = file.getParent();
        System.out.println("Parent is: " + parent);

        System.out.println("____________________________________________________________");
    }

}

Recursively list all files in a directory including files in symlink directories

in case you would like to print all file contents: find . -type f -exec cat {} +

Move branch pointer to different commit without checkout

Honestly, I'm surprised how nobody thought about the git push command:

git push -f . <destination>:<branch>

The dot ( . ) refers the local repository, and you may need the -f option because the destination could be "behind its remote counterpart".

Although this command is used to save your changes in your server, the result is exactly the same as if moving the remote branch (<branch>) to the same commit as the local branch (<destination>)

Cron job every three days

I don't think you have what you need with:

0 0 */3 * * ## <<< WARNING!!! CAUSES UNEVEN INTERVALS AT END OF MONTH!!

Unfortunately, the */3 is setting the interval on every n day of the month and not every n days. See: explanation here. At the end of the month there is recurring issue guaranteed.

1st  at 2019-02-01 00:00:00
then at 2019-02-04 00:00:00 << 3 days, etc. OK
then at 2019-02-07 00:00:00
...
then at 2019-02-25 00:00:00
then at 2019-01-28 00:00:00
then at 2019-03-01 00:00:00 << 1 day WRONG
then at 2019-03-04 00:00:00
...

According to this article, you need to add some modulo math to the command being executed to get a TRUE "every N days". For example:

0 0 * * *  bash -c '(( $(date +\%s) / 86400 \% 3 == 0 )) && runmyjob.sh

In this example, the job will be checked daily at 12:00 AM, but will only execute when the number of days since 01-01-1970 modulo 3 is 0.

If you want it to be every 3 days from a specific date, use the following format:

0 0 * * *  bash -c '(( $(date +\%s -d "2019-01-01") / 86400 \% 3 == 0 )) && runmyjob.sh

How to connect to my http://localhost web server from Android Emulator

Try http://10.0.2.2:8080/ where 8080 is your port number. It worked perfectly. If you just try 10.0.2.2 it won't work. You need to add port number to it. Also if Microsoft IIS has been installed try turning off that feature from control panel (if using any windows os) and then try as given above.

how to find all indexes and their columns for tables, views and synonyms in oracle

Your query should work for synonyms as well as the tables. However, you seem to expect indexes on views where there are not. Maybe is it materialized views ?

SQL Insert Query Using C#

Try

String query = "INSERT INTO dbo.SMS_PW (id,username,password,email) VALUES (@id,@username, @password, @email)";
using(SqlConnection connection = new SqlConnection(connectionString))
using(SqlCommand command = new SqlCommand(query, connection))
{
    //a shorter syntax to adding parameters
    command.Parameters.Add("@id", SqlDbType.NChar).Value = "abc";

    command.Parameters.Add("@username", SqlDbType.NChar).Value = "abc";

    //a longer syntax for adding parameters
    command.Parameters.Add("@password", SqlDbType.NChar).Value = "abc";

    command.Parameters.Add("@email", SqlDbType.NChar).Value = "abc";

    //make sure you open and close(after executing) the connection
    connection.Open();
    command.ExecuteNonQuery();
}

Using an image caption in Markdown Jekyll

A slight riff on the top voted answer that I found to be a little more explicit is to use the jekyll syntax for adding a class to something and then style it that way.

So in the post you would have:

![My image](/images/my-image.png)

{:.image-caption}
*The caption for my image*

And then in your CSS file you can do something like this:

.image-caption {
  text-align: center;
  font-size: .8rem;
  color: light-grey;

Comes out looking good!

How to keep a Python script output window open?

You can open PowerShell and type "python". After Python has been imported, you can copy paste the source code from your favourite text-editor to run the code.

The window won't close.

How do I correct the character encoding of a file?

If you see question marks in the file or if the accents are already lost, going back to utf8 will not help your cause. e.g. if café became cafe - changing encoding alone will not help (and you'll need original data).

Can you paste some text here, that'll help us answer for sure.

Creating a new user and password with Ansible

This is the easy way:

---
- name: Create user
  user: name=user shell=/bin/bash home=/srv/user groups=admin,sudo generate_ssh_key=yes ssh_key_bits=2048
- name: Set password to user
  shell: echo user:plain_text_password | sudo chpasswd
  no_log: True

Difference between Pragma and Cache-Control headers?

Stop using (HTTP 1.0)	Replaced with (HTTP 1.1 since 1999)
Expires: [date]	Cache-Control: max-age=[seconds]
Pragma: no-cache	Cache-Control: no-cache

If it's after 1999, and you're still using Expires or Pragma, you're doing it wrong.

I'm looking at you Stackoverflow:

200 OK
Pragma: no-cache
Content-Type: application/json
X-Frame-Options: SAMEORIGIN
X-Request-Guid: a3433194-4a03-4206-91ea-6a40f9bfd824
Strict-Transport-Security: max-age=15552000
Content-Length: 54
Accept-Ranges: bytes
Date: Tue, 03 Apr 2018 19:03:12 GMT
Via: 1.1 varnish
Connection: keep-alive
X-Served-By: cache-yyz8333-YYZ
X-Cache: MISS
X-Cache-Hits: 0
X-Timer: S1522782193.766958,VS0,VE30
Vary: Fastly-SSL
X-DNS-Prefetch-Control: off
Cache-Control: private

tl;dr: Pragma is a legacy of HTTP/1.0 and hasn't been needed since Internet Explorer 5, or Netscape 4.7. Unless you expect some of your users to be using IE5: it's safe to stop using it.

Expires: [date] (deprecated - HTTP 1.0)
Pragma: no-cache (deprecated - HTTP 1.0)
Cache-Control: max-age=[seconds]
Cache-Control: no-cache (must re-validate the cached copy every time)

And the conditional requests:

Etag (entity tag) based conditional requests
- Server: Etag: W/“1d2e7–1648e509289”
- Client: If-None-Match: W/“1d2e7–1648e509289”
- Server: 304 Not Modified
Modified date based conditional requests
- Server: last-modified: Thu, 09 May 2019 19:15:47 GMT
- Client: If-Modified-Since: Fri, 13 Jul 2018 10:49:23 GMT
- Server: 304 Not Modified

last-modified: Thu, 09 May 2019 19:15:47 GMT

How to sum up elements of a C++ vector?

Why perform the summation forwards when you can do it backwards? Given:

std::vector<int> v;     // vector to be summed
int sum_of_elements(0); // result of the summation

We can use subscripting, counting backwards:

for (int i(v.size()); i > 0; --i)
    sum_of_elements += v[i-1];

We can use range-checked "subscripting," counting backwards (just in case):

for (int i(v.size()); i > 0; --i)
    sum_of_elements += v.at(i-1);

We can use reverse iterators in a for loop:

for(std::vector<int>::const_reverse_iterator i(v.rbegin()); i != v.rend(); ++i)
    sum_of_elements += *i;

We can use forward iterators, iterating backwards, in a for loop (oooh, tricky!):

for(std::vector<int>::const_iterator i(v.end()); i != v.begin(); --i)
    sum_of_elements += *(i - 1);

We can use accumulate with reverse iterators:

sum_of_elems = std::accumulate(v.rbegin(), v.rend(), 0);

We can use for_each with a lambda expression using reverse iterators:

std::for_each(v.rbegin(), v.rend(), [&](int n) { sum_of_elements += n; });

So, as you can see, there are just as many ways to sum the vector backwards as there are to sum the vector forwards, and some of these are much more exciting and offer far greater opportunity for off-by-one errors.

ng-change get new value and original value

Also you can use

<select ng-change="updateValue(user, oldValue)"     
       ng-init="oldValue=0"
       ng-focus="oldValue=user.id"
       ng-model="user.id" ng-options="user.id as user.name for user in users">
</select>

Java optional parameters

varargs could do that (in a way). Other than that, all variables in the declaration of the method must be supplied. If you want a variable to be optional, you can overload the method using a signature which doesn't require the parameter.

private boolean defaultOptionalFlagValue = true;

public void doSomething(boolean optionalFlag) {
    ...
}

public void doSomething() {
    doSomething(defaultOptionalFlagValue);
}

Django set field value after a form is initialized

Something like Nigel Cohen's would work if you were adding data to a copy of the collected set of form data:

form = FormType(request.POST)
if request.method == "POST":
    formcopy = form(request.POST.copy())
    formcopy.data['Email'] = GetEmailString()

Is there an addHeaderView equivalent for RecyclerView?

There is one more solution that covers all the use cases above: CompoundAdapter: https://github.com/negusoft/CompoundAdapter-android

You can create a AdapterGroup that holds your Adapter as it is, along with an adapter with a single item to represent the header. The code is easy and readable:

AdapterGroup adapterGroup = new AdapterGroup();
adapterGroup.addAdapter(SingleAdapter.create(R.layout.header));
adapterGroup.addAdapter(new CommentAdapter(...));

recyclerView.setAdapter(adapterGroup);

AdapterGroup allows nesting too, so for a adapter with sections, you may create a AdapterGroup per section. Then put all the sections in a root AdapterGroup.

iOS how to set app icon and launch images

To save a bit time:

1) You can mark your app icon images all in finder and drag them into your Assets catalog all at once by dragging into one of the empty slots of the app icon imageset. When you hold your drag over the slot, several of the other slots look selected and when you drop those all will be filled up at once. Note that this works in XCode 8 (I haven't tried XCode 7), but in XCode 9 beta not yet.

Dragging into app icon Asset catalog imageset

2) The "Technical Q&A QA1686" apple documentation site has the sizes per app icon slot already calculated for you in a nice image and also contains the correct image names conventions.

Want to download a Git repository, what do I need (windows machine)?

Install mysysgit. (Same as Greg Hewgill's answer.)

Install Tortoisegit. (Tortoisegit requires mysysgit or something similiar like Cygwin.)

After TortoiseGit is installed, right-click on a folder, select Git Clone..., then enter the Url of the repository, then click Ok.

This answer is not any better than just installing mysysgit, but you can avoid the dreaded command line. :)

Is there a way to include commas in CSV columns without breaking the formatting?

In addition to the points in other answers: one thing to note if you are using quotes in Excel is the placement of your spaces. If you have a line of code like this:

print '%s, "%s", "%s", "%s"' % (value_1, value_2, value_3, value_4)

Excel will treat the initial quote as a literal quote instead of using it to escape commas. Your code will need to change to

print '%s,"%s","%s","%s"' % (value_1, value_2, value_3, value_4)

It was this subtlety that brought me here.

How to give a Linux user sudo access?

You need run visudo and in the editor that it opens write:

igor    ALL=(ALL) ALL

That line grants all permissions to user igor.

If you want permit to run only some commands, you need to list them in the line:

igor    ALL=(ALL) /bin/kill, /bin/ps

PHP Converting Integer to Date, reverse of strtotime

I guess you are asking why is 1388516401 equal to 2014-01-01...?

There is an historical reason for that. There is a 32-bit integer variable, called time_t, that keeps the count of the time elapsed since 1970-01-01 00:00:00. Its value expresses time in seconds. This means that in 2014-01-01 00:00:01 time_t will be equal to 1388516401.

This leads us for sure to another interesting fact... In 2038-01-19 03:14:07 time_t will reach 2147485547, the maximum value for a 32-bit number. Ever heard about John Titor and the Year 2038 problem? :D

Powershell Get-ChildItem most recent file in directory

If you want the latest file in the directory and you are using only the LastWriteTime to determine the latest file, you can do something like below:

gci path | sort LastWriteTime | select -last 1

On the other hand, if you want to only rely on the names that have the dates in them, you should be able to something similar

gci path | select -last 1

Also, if there are directories in the directory, you might want to add a ?{-not $_.PsIsContainer}

Two models in one view in ASP MVC 3

you can't declare two model on one view, try to use Html.Action("Person", "[YourController]") & Html.Action("Order", "[YourController]").

Good luck.

ECMAScript 6 arrow function that returns an object

If the body of the arrow function is wrapped in curly braces, it is not implicitly returned. Wrap the object in parentheses. It would look something like this.

p => ({ foo: 'bar' })

By wrapping the body in parens, the function will return { foo: 'bar }.

Hopefully, that solves your problem. If not, I recently wrote an article about Arrow functions which covers it in more detail. I hope you find it useful. Javascript Arrow Functions

PDF Parsing Using Python - extracting formatted and plain texts

That's a difficult problem to solve since visually similar PDFs may have a wildly differing structure depending on how they were produced. In the worst case the library would need to basically act like an OCR. On the other hand, the PDF may contain sufficient structure and metadata for easy removal of tables and figures, which the library can be tailored to take advantage of.

I'm pretty sure there are no open source tools which solve your problem for a wide variety of PDFs, but I remember having heard of commercial software claiming to do exactly what you ask for. I'm sure you'll run into them while googling.

How can I make the Android emulator show the soft keyboard?

I found out how to do this on the Android emulator itself (Menu, "Settings" App - not the settings of the emulator outside). All you need to do is:

open settings app -> Language & Input -> Go to the "Keyboard & Input Methods -> click Default

This will bring up a Dialog in which case you can then disable the Hardware Keyboard by switching the hardware keyboard from on to off. This will disable the Hardware keyboard and enable the softkeyboard.

Reading in double values with scanf in c

Use this line of code when scanning the second value: scanf(" %lf", &b); also replace all %ld with %lf.

It's a problem related with input stream buffer. You can also use fflush(stdin); after the first scanning to clear the input buffer and then the second scanf will work as expected. An alternate way is place a getch(); or getchar(); function after the first scanf line.

What is setContentView(R.layout.main)?

public void onCreate(Bundle savedinstanceState) {
            super.onCreate(savedinstanceState);

            Button testButon = new Button(this);

            setContentView(testButon);

            show();

}

How to create a self-signed certificate for a domain name for development?

Another easy way to generate a self signed certificate is to use Jexus Manager,

Jexus Manager

Choose a server node in the Connections panel.
In the middle panel, click Server Certificates icon to open the management page.
Under Actions panel, click “Generate Self-Signed Certificate...” menu item.

https://www.jexusmanager.com/en/latest/tutorials/self-signed.html

What to do with "Unexpected indent" in python?

Indentation in Python is important and this is just not for code readability, unlike many other programming languages. If there is any white space or tab in your code between consecutive commands, python will give this error as Python is sensitive to this. We are likely to get this error when we do copy and paste of code to any Python. Make sure to identify and remove these spaces using a text editor like Notepad++ or manually remove the whitespace from the line of code where you are getting an error.

Step1 :Gives error 
L = [[1, 2, 3], [4, 5, 6], [7, 8, 9, 10]]
print(L[2: ])

Step2: L = [[1, 2, 3], [4, 5, 6], [7, 8, 9, 10]]print(L[2: ])

Step3: No error after space was removed
L = [[1, 2, 3], [4, 5, 6], [7, 8, 9, 10]]
print(L[2: ])
OUTPUT: [[7, 8, 9, 10]]

Thanks!

how to read certain columns from Excel using Pandas - Python

You can use column indices (letters) like this:

import pandas as pd
import numpy as np
file_loc = "path.xlsx"
df = pd.read_excel(file_loc, index_col=None, na_values=['NA'], usecols = "A,C:AA")
print(df)

[Corresponding documentation][1]:

usecolsint, str, list-like, or callable default None

If None, then parse all columns.

If str, then indicates comma separated list of Excel column letters and column ranges (e.g. “A:E” or “A,C,E:F”). Ranges are inclusive of both sides.

If list of int, then indicates list of column numbers to be parsed.

If list of string, then indicates list of column names to be parsed.

New in version 0.24.0.

If callable, then evaluate each column name against it and parse the column if the callable returns True.

Returns a subset of the columns according to behavior above.

New in version 0.24.0.

Wordpress 403/404 Errors: You don't have permission to access /wp-admin/themes.php on this server

Hopefully people will find this answer as there are many, many posts about this on the web. Many people suggested it was an .htaccess problem, and for me it was. However, I had been looking in the .htaccess in the root, not in the .htaccess in the wp-admin folder. Normally, I work on this site in particular through terminal services, so when it booted me and I couldn't log back in, I was trying to access it from my home computer (and it's IP).

Silly me forgot the IP restriction I had placed in the wp-admin .htaccess file.

AuthName "Protected"
AuthType Basic
<Limit GET POST>
order deny,allow
deny from all
allow from 11.11.11.11
</Limit>

If you have something like this in your wp-admin .htaccess files, that would easily explain why all the sites you work on ceased to function at the same time. Internet providers occasionally rotate IPs so that nobody is running a server from home without paying for it.

SQL Server: convert ((int)year,(int)month,(int)day) to Datetime

You could convert your values into a 'Decimal' datetime and convert it then to a real datetime column:

select cast(rtrim(year *10000+ month *100+ day) as datetime) as Date from DateTable

See here as well for more info.

Git cli: get user info from username

Try this

git config user.name

git config command stores and gives all the information.

git config -l

This commands gives you all the required info that you want.

You can change the information using

git config --global user.name "<Your-name>"

Similarly you can change many info shown to you using -l option.

Simplest way to append data to a SQL Column

How to install and use "make" in Windows?

Download make.exe from their official site GnuWin32

In the Download session, click Complete package, except sources.
Follow the installation instructions.
Once finished, add the <installation directory>/bin/ to the PATH variable.

Now you will be able to use make in cmd.

SQL UPDATE all values in a field with appended string CONCAT not working

convert the NULL values with empty string by wrapping it in COALESCE

"UPDATE table SET data = CONCAT(COALESCE(`data`,''), 'a')"

Use CONCAT_WS instead:

"UPDATE table SET data = CONCAT_WS(',',data, 'a')"

Merging dictionaries in C#

I'm very late to the party and perhaps missing something, but if either there are no duplicate keys or, as the OP says, "In case of collision, it doesn't matter which value is saved to the dict as long as it's consistent," what's wrong with this one (merging D2 into D1)?

foreach (KeyValuePair<string,int> item in D2)
            {
                 D1[item.Key] = item.Value;
            }

It seems simple enough, maybe too simple, I wonder if I'm missing something. This is what I'm using in some code where I know there are no duplicate keys. I'm still in testing, though, so I'd love to know now if I'm overlooking something, instead of finding out later.

Bootstrap row class contains margin-left and margin-right which creates problems

To remove the margins on all rows:

.row {
    margin: 0px !important;
}

Is there a way to detect if an image is blurry?

Yes, it is. Compute the Fast Fourier Transform and analyse the result. The Fourier transform tells you which frequencies are present in the image. If there is a low amount of high frequencies, then the image is blurry.

Defining the terms 'low' and 'high' is up to you.

Edit:

As stated in the comments, if you want a single float representing the blurryness of a given image, you have to work out a suitable metric.

nikie's answer provide such a metric. Convolve the image with a Laplacian kernel:

   1
1 -4  1
   1

And use a robust maximum metric on the output to get a number which you can use for thresholding. Try to avoid smoothing too much the images before computing the Laplacian, because you will only find out that a smoothed image is indeed blurry :-).

C# DateTime to "YYYYMMDDHHMMSS" format

If you use ReSharper, get help with ':' (see image)

This Row already belongs to another table error when trying to add rows?

yourTable.ImportRow(dataRow);

It's because the row you're copying doesn't have the same TableName:

For example, try:

Table1.TableName = "Table1";
Table2.TableName = "Table2";

java.util.Date format conversion yyyy-mm-dd to mm-dd-yyyy

It is simple use below codes.

final Date todayDate = new Date();

System.out.println(todayDate);

System.out.println(new SimpleDateFormat("MM-dd-yyyy").format(todayDate));

System.out.println(new SimpleDateFormat("yyyy-MM-dd").format(todayDate));

System.out.println(todayDate);

When to use RDLC over RDL reports?

Q: What is the difference between RDL and RDLC formats?

A: RDL files are created by the SQL Server 2005 version of Report Designer. RDLC files are created by the Visual Studio 2008 version of Report Designer.

RDL and RDLC formats have the same XML schema. However, in RDLC files, some values (such as query text) are allowed to be empty, which means that they are not immediately ready to be published to a Report Server. The missing values can be entered by opening the RDLC file using the SQL Server 2005 version of Report Designer. (You have to rename .rdlc to .rdl first.)

RDL files are fully compatible with the ReportViewer control runtime. However, RDL files do not contain some information that the design-time of the ReportViewer control depends on for automatically generating data-binding code. By manually binding data, RDL files can be used in the ReportViewer control. New! See also the RDL Viewer sample program.

Note that the ReportViewer control does not contain any logic for connecting to databases or executing queries. By separating out such logic, the ReportViewer has been made compatible with all data sources, including non-database data sources. However this means that when an RDL file is used by the ReportViewer control, the SQL related information in the RDL file is simply ignored by the control. It is the host application's responsibility to connect to databases, execute queries and supply data to the ReportViewer control in the form of ADO.NET DataTables.

http://www.gotreportviewer.com/

How to post ASP.NET MVC Ajax form using JavaScript rather than submit button

I've tried a few times to get the ajax form submit working nicely, but always met with either complete failure or too many compromises. Here's an example of page that uses the jQuery Form plug-in inside of a MVC page to update a list of projects (using a partially rendered control) as the user types in an input box:

<div class="searchBar">
    <form action="<%= Url.Action ("SearchByName") %>" method="get" class="searchSubmitForm">
        <label for="projectName">Search:</label>
        <%= Html.TextBox ("projectName") %>
        <input class="submit" type="submit" value="Search" />
    </form>
</div>
<div id="projectList">
    <% Html.RenderPartial ("ProjectList", Model); %>
</div>

<script type="text/javascript">
    jQuery(document).ready(function() {
        jQuery("#projectName").keyup(function() {
            jQuery(".searchSubmitForm").submit();
        });

        jQuery(".searchSubmitForm").submit(function() {
            var options = {
                target : '#projectList'
            }

            jQuery(this).ajaxSubmit(options);

            return false;
        });

        // We remove the submit button here - good Javascript depreciation technique
        jQuery(".submit").remove();
    });
</script>

And on the controller side:

public ActionResult SearchByName (string projectName)
{
    var service = Factory.GetService<IProjectService> ();
    var result = service.GetProjects (projectName);

    if (Request.IsAjaxRequest ())
        return PartialView ("ProjectList", result);
    else
    {
        TempData["Result"] = result;
        TempData["SearchCriteria"] = projectName;

        return RedirectToAction ("Index");
    }
}

public ActionResult Index ()
{
    IQueryable<Project> projects;
    if (TempData["Result"] != null)
        projects = (IQueryable<Project>)TempData["Result"];
    else
    {
        var service = Factory.GetService<IProjectService> ();
        projects = service.GetProjects ();
    }

    ViewData["projectName"] = TempData["SearchCriteria"];

    return View (projects);
}

Property getters and setters

Update for Swift 5.1

As of Swift 5.1 you can now get your variable without using get keyword. For example:

var helloWorld: String {
"Hello World"
}

How can I debug a HTTP POST in Chrome?

It has a tricky situation: If you submit a post form, then Chrome will open a new tab to send the request. It's right until now, but if it triggers an event to download file(s), this tab will close immediately so that you cannot capture this request in the Dev Tool.

Solution: Before submitting the post form, you need to cut off your network, which makes the request cannot send successfully so that the tab will not be closed. And then you can capture the request message in the Chrome Devtool(Refreshing the new tab if necessary)

How to get current domain name in ASP.NET

the Request.ServerVariables object works for me. I don't know of any reason not to use it.

ServerVariables["SERVER_NAME"] and ServerVariables["HTTP_URL"] should get what you're looking for

How to upgrade Git on Windows to the latest version?

Git Bash

Note, if you are instead looking to find out what version of Git Bash you are running, or want to see if you need to update Git Bash, it is part of Git for Windows.

So your Git Bash version is:

git --version

git version 2.23.0.windows.1

Note that it is technically different from Bash. On my same machine when I run:

echo $BASH_VERSION

4.4.23(1)-release

Git for Windows installer

To update to the latest version of Git and Git Bash, you can download and install the latest version of git for Windows. As per FAQ, settings/customizations should be preserved if they were installed in the appropriate configuration folders.

Note: Their installer is actually intelligently designed to do the right thing (except for telling you that it's doing the right thing automatically). If you are doing an update, then every screen on the installer is pre-marked with the settings from your current (soon to be previous) install.

It is not showing you generic default settings. You do not need to look any of them up, or fear for breaking your carefully honed setup. Just leave everything as is, to retain your previous choices.

In fact, they made it even easier (if only it was clear that they did so).
There is a checkbox at the bottom [] Show only new settings (I don't remember the exact wording). Since nothing on the first screen changes when you mark the box, it is not exactly obvious what it is for. If you mark the box, then all of your current settings will be retained, and it will skip showing those subsequent settings screens to you. Only screens with newly introduced settings will be shown.

git update-git-for-windows

Alternatively, as others have noted, you can also update Git Bash and Git (by definition, both are always updated at the same time) from the Git Bash command line, via:

git update-git-for-windows

If you type git update, git kindly reminds you that the command has been updated to git update-git-for-windows:

Warning! git update has been deprecated;
Please use git update-git-for-windows instead.
Git for Windows 2.26.0.windows.1 (64bit)
Up to date

How to make a website secured with https

I think you are getting confused with your site Authentication and SSL.

If you need to get your site into SSL, then you would need to install a SSL certificate into your web server. You can buy a certificate for yourself from one of the places like Symantec etc. The certificate would contain your public/private key pair, along with other things.

You wont need to do anything in your source code, and you can still continue to use your Form Authntication (or any other) in your site. Its just that, any data communication that takes place between the web server and the client will encrypted and signed using your certificate. People would use secure-HTTP (https://) to access your site.

View this for more info --> http://en.wikipedia.org/wiki/Transport_Layer_Security

Should have subtitle controller already set Mediaplayer error Android

A developer recently added subtitle support to VideoView.

When the MediaPlayer starts playing a music (or other source), it checks if there is a SubtitleController and shows this message if it's not set. It doesn't seem to care about if the source you want to play is a music or video. Not sure why he did that.

Short answer: Don't care about this "Exception".

Edit :

Still present in Lollipop,

If MediaPlayer is only used to play audio files and you really want to remove these errors in the logcat, the code bellow set an empty SubtitleController to the MediaPlayer.

It should not be used in production environment and may have some side effects.

static MediaPlayer getMediaPlayer(Context context){

    MediaPlayer mediaplayer = new MediaPlayer();

    if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.KITKAT) {
        return mediaplayer;
    }

    try {
        Class<?> cMediaTimeProvider = Class.forName( "android.media.MediaTimeProvider" );
        Class<?> cSubtitleController = Class.forName( "android.media.SubtitleController" );
        Class<?> iSubtitleControllerAnchor = Class.forName( "android.media.SubtitleController$Anchor" );
        Class<?> iSubtitleControllerListener = Class.forName( "android.media.SubtitleController$Listener" );

        Constructor constructor = cSubtitleController.getConstructor(new Class[]{Context.class, cMediaTimeProvider, iSubtitleControllerListener});

        Object subtitleInstance = constructor.newInstance(context, null, null);

        Field f = cSubtitleController.getDeclaredField("mHandler");

        f.setAccessible(true);
        try {
            f.set(subtitleInstance, new Handler());
        }
        catch (IllegalAccessException e) {return mediaplayer;}
        finally {
            f.setAccessible(false);
        }

        Method setsubtitleanchor = mediaplayer.getClass().getMethod("setSubtitleAnchor", cSubtitleController, iSubtitleControllerAnchor);

        setsubtitleanchor.invoke(mediaplayer, subtitleInstance, null);
        //Log.e("", "subtitle is setted :p");
    } catch (Exception e) {}

    return mediaplayer;
}

This code is trying to do the following from the hidden API

SubtitleController sc = new SubtitleController(context, null, null);
sc.mHandler = new Handler();
mediaplayer.setSubtitleAnchor(sc, null)

Combining COUNT IF AND VLOOK UP EXCEL

This is trivial when you use SUMPRODUCT. Por ejemplo:

=SUMPRODUCT((worksheet2!A:A=A3)*1)

You could put the above formula in cell B3, where A3 is the name you want to find in worksheet2.

Maximum and minimum values in a textbox

Here's a simple function that does what you need:

<script type="text/javascript">
function minmax(value, min, max) 
{
    if(parseInt(value) < min || isNaN(parseInt(value))) 
        return min; 
    else if(parseInt(value) > max) 
        return max; 
    else return value;
}
</script>
<input type="text" name="textWeight" id="txtWeight" maxlength="5" onkeyup="this.value = minmax(this.value, 0, 100)"/>

If the input is not numeric it replaces it with a zero

Styling the last td in a table with css

You can use the col element as specified in HTML 4.0 (link). It works in every browser. You can give it an ID or a class or an inline style. only caveat is that it affects the whole column across all rows. Example:

<table>
    <col />
    <col width="50" />
    <col id="anId" />
    <col class="whatever" />
    <col style="border:1px solid #000;" />
    <tbody>
        <tr>
            <td>One</td>
            <td>Two</td>
            <td>Three</td>
            <td>Four</td>
            <td>Five</td>
        </tr>
    </tbody>
</table>

iTunes Connect Screenshots Sizes for all iOS (iPhone/iPad/Apple Watch) devices

For iPhone 5.5" display you need to change the simulator to "Physical Size" on iPhone 8 Plus

What is the Gradle artifact dependency graph command?

Ah, since I had no dependencies in my master project, "gradle dependencies" only lists those and not subproject dependencies so the correct command ended up being

 gradle :<subproject>:dependencies

so for me this was

 gradle :master:dependencies

file path Windows format to java format

String path = "C:\\Documents and Settings\\someDir";
path = path.replaceAll("\\\\", "/");

In Windows you should use four backslash but not two.

What is parsing in terms that a new programmer would understand?

Parsing to me is breaking down something into meaningful parts... using a definable or predefined known, common set of part "definitions".

For programming languages there would be keyword parts, usable punctuation sequences...

For pumpkin pie it might be something like the crust, filling and toppings.

For written languages there might be what a word is, a sentence, what a verb is...

For spoken languages it might be tone, volume, mood, implication, emotion, context

Syntax analysis (as well as common sense after all) would tell if what your are parsing is a pumpkinpie or a programming language. Does it have crust? well maybe it's pumpkin pudding or perhaps a spoken language !

One thing to note about parsing stuff is there are usually many ways to break things into parts.

For example you could break up a pumpkin pie by cutting it from the center to the edge or from the bottom to the top or with a scoop to get the filling out or by using a sledge hammer or eating it.

And how you parse things would determine if doing something with those parts will be easy or hard.

In the "computer languages" world, there are common ways to parse text source code. These common methods (algorithims) have titles or names. Search the Internet for common methods/names for ways to parse languages. Wikipedia can help in this regard.

How to convert a list of numbers to jsonarray in Python

Use the json module to produce JSON output:

import json

with open(outputfilename, 'wb') as outfile:
    json.dump(row, outfile)

This writes the JSON result directly to the file (replacing any previous content if the file already existed).

If you need the JSON result string in Python itself, use json.dumps() (added s, for 'string'):

json_string = json.dumps(row)

The L is just Python syntax for a long integer value; the json library knows how to handle those values, no L will be written.

Demo string output:

>>> import json
>>> row = [1L,[0.1,0.2],[[1234L,1],[134L,2]]]
>>> json.dumps(row)
'[1, [0.1, 0.2], [[1234, 1], [134, 2]]]'

How to save .xlsx data to file as a blob

try FileSaver.js library. it might help.

https://github.com/eligrey/FileSaver.js/

Right way to convert data.frame to a numeric matrix, when df also contains strings?

Another way of doing it is by using the read.table() argument colClasses to specify the column type by making colClasses=c(*column class types*). If there are 6 columns whose members you want as numeric, you need to repeat the character string "numeric" six times separated by commas, importing the data frame, and as.matrix() the data frame. P.S. looks like you have headers, so I put header=T.

as.matrix(read.table(SFI.matrix,header=T,
colClasses=c("numeric","numeric","numeric","numeric","numeric","numeric"),
sep=","))

Why does my Eclipse keep not responding?

This may help

In your eclipse,

1) Go to Help

2) Click Eclipse marketplace

3) search - optimizer

install "optimizer for eclipse"

enter image description here

How to get all subsets of a set? (powerset)

TL;DR (go directly to Simplification)

I know I have previously added an answer, but I really like my new implementation. I am taking a set as input, but it actually could be any iterable, and I am returning a set of sets which is the power set of the input. I like this approach because it is more aligned with the mathematical definition of power set (set of all subsets).

def power_set(A):
    """A is an iterable (list, tuple, set, str, etc)
    returns a set which is the power set of A."""
    length = len(A)
    l = [a for a in A]
    ps = set()

    for i in range(2 ** length):
        selector = f'{i:0{length}b}'
        subset = {l[j] for j, bit in enumerate(selector) if bit == '1'}
        ps.add(frozenset(subset))

    return ps

If you want exactly the output you posted in your answer use this:

>>> [set(s) for s in power_set({1, 2, 3, 4})]
[{3, 4},
 {2},
 {1, 4},
 {2, 3, 4},
 {2, 3},
 {1, 2, 4},
 {1, 2},
 {1, 2, 3},
 {3},
 {2, 4},
 {1},
 {1, 2, 3, 4},
 set(),
 {1, 3},
 {1, 3, 4},
 {4}]

Explanation

It is known that the number of elements of the power set is 2 ** len(A), so that could clearly be seen in the for loop.

I need to convert the input (ideally a set) into a list because by a set is a data structure of unique unordered elements, and the order will be crucial to generate the subsets.

selector is key in this algorithm. Note that selector has the same length as the input set, and to make this possible it is using an f-string with padding. Basically, this allows me to select the elements that will be added to each subset during each iteration. Let's say the input set has 3 elements {0, 1, 2}, so selector will take values between 0 and 7 (inclusive), which in binary are:

So, each bit could serve as an indicator if an element of the original set should be added or not. Look at the binary numbers, and just think of each number as an element of the super set in which 1 means that an element at index j should be added, and 0 means that this element should not be added.

I am using a set comprehension to generate a subset at each iteration, and I convert this subset into a frozenset so I can add it to ps (power set). Otherwise, I won't be able to add it because a set in Python consists only of immutable objects.

Simplification

You can simplify the code using some python comprehensions, so you can get rid of those for loops. You can also use zip to avoid using j index and the code will end up as the following:

def power_set(A):
    length = len(A)
    return {
        frozenset({e for e, b in zip(A, f'{i:{length}b}') if b == '1'})
        for i in range(2 ** length)
    }

That's it. What I like of this algorithm is that is clearer and more intuitive than others because it looks quite magical to rely on itertools even though it works as expected.

Delete a row in DataGridView Control in VB.NET

Assuming you are using Windows forms, you could allow the user to select a row and in the delete key click event. It is recommended that you allow the user to select 1 row only and not a group of rows (myDataGridView.MultiSelect = false)

Private Sub pbtnDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDelete.Click

        If myDataGridView.SelectedRows.Count > 0 Then
            'you may want to add a confirmation message, and if the user confirms delete
            myDataGridView.Rows.Remove(myDataGridView.SelectedRows(0))
        Else
            MessageBox.Show("Select 1 row before you hit Delete")
        End If

    End Sub

Note that this will not delete the row form the database until you perform the delete in the database.

How to align two divs side by side using the float, clear, and overflow elements with a fixed position div/

This answer may have to be modified depending on what you were trying to achieve with position: fixed;. If all you want is two columns side by side then do the following:

http://jsfiddle.net/8weSA/1/

I floated both columns to the left.

Note: I added min-height to each column for illustrative purposes and I simplified your CSS.

_x000D_

body {_x000D_
  background-color: #444;_x000D_
  margin: 0;_x000D_
}_x000D_
_x000D_
#wrapper {_x000D_
  width: 1005px;_x000D_
  margin: 0 auto;_x000D_
}_x000D_
_x000D_
#leftcolumn,_x000D_
#rightcolumn {_x000D_
  border: 1px solid white;_x000D_
  float: left;_x000D_
  min-height: 450px;_x000D_
  color: white;_x000D_
}_x000D_
_x000D_
#leftcolumn {_x000D_
  width: 250px;_x000D_
  background-color: #111;_x000D_
}_x000D_
_x000D_
#rightcolumn {_x000D_
  width: 750px;_x000D_
  background-color: #777;_x000D_
}

_x000D_

<div id="wrapper">_x000D_
  <div id="leftcolumn">_x000D_
    Left_x000D_
  </div>_x000D_
  <div id="rightcolumn">_x000D_
    Right_x000D_
  </div>_x000D_
</div>

_x000D_

If you would like the left column to stay in place as you scroll do the following:

http://jsfiddle.net/8weSA/2/

Here we float the right column to the right while adding position: relative; to #wrapper and position: fixed; to #leftcolumn.

Note: I again used min-height for illustrative purposes and can be removed for your needs.

_x000D_

body {_x000D_
  background-color: #444;_x000D_
  margin: 0;_x000D_
}_x000D_
_x000D_
#wrapper {_x000D_
  width: 1005px;_x000D_
  margin: 0 auto;_x000D_
  position: relative;_x000D_
}_x000D_
_x000D_
#leftcolumn,_x000D_
#rightcolumn {_x000D_
  border: 1px solid white;_x000D_
  min-height: 750px;_x000D_
  color: white;_x000D_
}_x000D_
_x000D_
#leftcolumn {_x000D_
  width: 250px;_x000D_
  background-color: #111;_x000D_
  min-height: 100px;_x000D_
  position: fixed;_x000D_
}_x000D_
_x000D_
#rightcolumn {_x000D_
  width: 750px;_x000D_
  background-color: #777;_x000D_
  float: right;_x000D_
}

_x000D_

<div id="wrapper">_x000D_
  <div id="leftcolumn">_x000D_
    Left_x000D_
  </div>_x000D_
  <div id="rightcolumn">_x000D_
    Right_x000D_
  </div>_x000D_
</div>

_x000D_

javascript find and remove object in array based on key value

I can grep the array for the id, but how can I delete the entire object where id == 88

Simply filter by the opposite predicate:

var data = $.grep(data, function(e){ 
     return e.id != id; 
});

Origin http://localhost is not allowed by Access-Control-Allow-Origin

By localhost you have to use the null origin. I recommend you to create a list of allowed hosts and check the request's Host header. If it is contained by the list, then by localhost send back an

res.header('Access-Control-Allow-Origin', "null");

by any other domain an

res.header('Access-Control-Allow-Origin', hostSentByTheRequestHeader);

If it is not contained by the list, then send back the servers host name, so the browser will hide the response by those requests.

This is much more secure, because by allow origin * and allow credentials everybody will be capable of for example stealing profile data of a logged in user, etc...

So to summarize something like this:

if (reqHost in allowedHosts)
    if (reqHost == "http://localhost")
        res.header('Access-Control-Allow-Origin', "null");
    else
        res.header('Access-Control-Allow-Origin', reqHost);
else
    res.header('Access-Control-Allow-Origin', serverHost);

is the most secure solution if you want to allow multiple other domains to access your page. (I guess you can figure out how the get the host request header and the server host by node.js.)

Using LINQ to find item in a List but get "Value cannot be null. Parameter name: source"

Here are more code examples that will produce the argument null exception:

List<Myobj> myList = null;
//from this point on, any linq statement you perform on myList will throw an argument null exception
myList.ToList();
myList.GroupBy(m => m.Id);
myList.Count();
myList.Where(m => m.Id == 0);
myList.Select(m => m.Id == 0);
//etc...

How to write a:hover in inline CSS?

So this isn't quite what the user was looking for, but I found this question searching for an answer and came up with something sort of related. I had a bunch of repeating elements that needed a new color/hover for a tab within them. I use handlebars, which is key to my solution, but other templateing languages may also work.

I defined some colors and passed them into the handlebars template for each element. At the top of the template I defined a style tag, and put in my custom class and hover color.

<style type="text/css">
    .{{chart.type}}-tab-hover:hover {
        background-color: {{chart.chartPrimaryHighlight}} !important;
    }
</style>

Then I used the style in the template:

<span class="financial-aid-details-header-text {{chart.type}}-tab-hover">
   Payouts
</span>

You may not need the !important

How to test if a dictionary contains a specific key?

'a' in x

and a quick search reveals some nice information about it: http://docs.python.org/3/tutorial/datastructures.html#dictionaries

Classpath resource not found when running as jar

Regarding to the originally error message

cannot be resolved to absolute file path because it does not reside in the file system

The following code could be helpful, to find the solution for the path problem:

Paths.get("message.txt").toAbsolutePath().toString();

With this you can determine, where the application expects the missing file. You can execute this in the main method of your application.

How can I use Timer (formerly NSTimer) in Swift?

Repeated event

You can use a timer to do an action multiple times, as seen in the following example. The timer calls a method to update a label every half second.

enter image description here

Here is the code for that:

import UIKit

class ViewController: UIViewController {

    var counter = 0
    var timer = Timer()

    @IBOutlet weak var label: UILabel!

    // start timer
    @IBAction func startTimerButtonTapped(sender: UIButton) {
        timer.invalidate() // just in case this button is tapped multiple times

        // start the timer
        timer = Timer.scheduledTimer(timeInterval: 0.5, target: self, selector: #selector(timerAction), userInfo: nil, repeats: true)
    }

    // stop timer
    @IBAction func cancelTimerButtonTapped(sender: UIButton) {
        timer.invalidate()
    }

    // called every time interval from the timer
    func timerAction() {
        counter += 1
        label.text = "\(counter)"
    }
}

Delayed event

You can also use a timer to schedule a one time event for some time in the future. The main difference from the above example is that you use repeats: false instead of true.

timer = Timer.scheduledTimer(timeInterval: 2.0, target: self, selector: #selector(delayedAction), userInfo: nil, repeats: false)

The above example calls a method named delayedAction two seconds after the timer is set. It is not repeated, but you can still call timer.invalidate() if you need to cancel the event before it ever happens.

Notes

If there is any chance of starting your timer instance multiple times, be sure that you invalidate the old timer instance first. Otherwise you lose the reference to the timer and you can't stop it anymore. (see this Q&A)
Don't use timers when they aren't needed. See the timers section of the Energy Efficiency Guide for iOS Apps.

How to work with dates and time in Swift

"Invalid JSON primitive" in Ajax processing

Using

data : JSON.stringify(obj)

in the above situation would have worked I believe.

Note: You should add json2.js library all browsers don't support that JSON object (IE7-) Difference between json.js and json2.js

Bash: Strip trailing linebreak from output

printf already crops the trailing newline for you:

$ printf '%s' $(wc -l < log.txt)

Detail:

printf will print your content in place of the %s string place holder.
If you do not tell it to print a newline (%s\n), it won't.

how to open popup window using jsp or jquery?

<a href="javaScript:{openPopUp();}"></a>
<form action="actionName">
<div id="divId" style="display:none;">
UsreName:<input type="text" name="userName"/>
</div>
</form>

function openPopUp()
{
  $('#divId').css('display','block');
$('#divId').dialog();
}

C Macro definition to determine big endian or little endian machine?

Use an inline function rather than a macro. Besides, you need to store something in memory which is a not-so-nice side effect of a macro.

You could convert it to a short macro using a static or global variable, like this:

static int s_endianess = 0;
#define ENDIANESS() ((s_endianess = 1), (*(unsigned char*) &s_endianess) == 0)

Exception: Unexpected end of ZLIB input stream

You have to call close() on the GZIPOutputStream before you attempt to read it. The final bytes of the file will only be written when the file is actually closed. (This is irrespective of any explicit buffering in the output stack. The stream only knows to compress and write the last bytes when you tell it to close. A flush() probably won't help ... though calling finish() instead of close() should work. Look at the javadocs.)

Here's the correct code (in Java);

package test;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

public class GZipTest {

    public static void main(String[] args) throws
                FileNotFoundException, IOException {
        String name = "/tmp/test";
        GZIPOutputStream gz = new GZIPOutputStream(new FileOutputStream(name));
        gz.write(10);
        gz.close();       // Remove this to reproduce the reported bug
        System.out.println(new GZIPInputStream(new FileInputStream(name)).read());
    }
}

(I've not implemented resource management or exception handling / reporting properly as they are not relevant to the purpose of this code. Don't treat this as an example of "good code".)

Printing leading 0's in C

You place a zero before the minimum field width:

printf("%05d", zipcode);

How do you get a string from a MemoryStream?

use a StreamReader, then you can use the ReadToEnd method that returns a string.

C# '@' before a String

It means to interpret the string literally (that is, you cannot escape any characters within the string if you use the @ prefix). It enhances readability in cases where it can be used.

For example, if you were working with a UNC path, this:

@"\\servername\share\folder"

is nicer than this:

"\\\\servername\\share\\folder"

Dropping connected users in Oracle database

Issue has been fixed using below procedure :

DECLARE
  v_user_exists NUMBER;
  user_name CONSTANT varchar2(20) := 'SCOTT';
BEGIN
  LOOP
    FOR c IN (SELECT s.sid, s.serial# FROM v$session s WHERE upper(s.username) = user_name)
    LOOP
      EXECUTE IMMEDIATE
        'alter system kill session ''' || c.sid || ',' || c.serial# || ''' IMMEDIATE';
    END LOOP;
    BEGIN
      EXECUTE IMMEDIATE 'drop user ' || user_name || ' cascade';
      EXCEPTION WHEN OTHERS THEN
      IF (SQLCODE = -1940) THEN
        NULL;
      ELSE
        RAISE;
      END IF;
    END;
    BEGIN
      SELECT COUNT(*) INTO v_user_exists FROM dba_users WHERE username = user_name;
      EXIT WHEN v_user_exists = 0;
    END;
  END LOOP;
END;
/

c# razor url parameter from view

@(ViewContext.RouteData.Values["parameterName"])

worked with ROUTE PARAM.

Request.Params["paramName"]

did not work with ROUTE PARAM.

Rename a column in MySQL

https://dev.mysql.com/doc/refman/8.0/en/alter-table.html

For MySQL 8

alter table creditReportXml_temp change column applicationID applicantID int(11);

destination path already exists and is not an empty directory

This just means that the git clone copied the files down from github and placed them into a folder. If you try to do it again it will not let you because it can't clone into a folder that has files into it. So if you think the git clone did not complete properly, just delete the folder and do the git clone again. The clone creates a folder the same name as the git repo.

Remove CSS class from element with JavaScript (no jQuery)

Edit

Okay, complete re-write. It's been a while, I've learned a bit and the comments have helped.

Node.prototype.hasClass = function (className) {
    if (this.classList) {
        return this.classList.contains(className);
    } else {
        return (-1 < this.className.indexOf(className));
    }
};

Node.prototype.addClass = function (className) {
    if (this.classList) {
        this.classList.add(className);
    } else if (!this.hasClass(className)) {
        var classes = this.className.split(" ");
        classes.push(className);
        this.className = classes.join(" ");
    }
    return this;
};

Node.prototype.removeClass = function (className) {
    if (this.classList) {
        this.classList.remove(className);
    } else {
        var classes = this.className.split(" ");
        classes.splice(classes.indexOf(className), 1);
        this.className = classes.join(" ");
    }
    return this;
};

Old Post

I was just working with something like this. Here's a solution I came up with...

// Some browsers don't have a native trim() function
if(!String.prototype.trim) {
    Object.defineProperty(String.prototype,'trim', {
        value: function() {
            return this.replace(/^\s+|\s+$/g,'');
        },
        writable:false,
        enumerable:false,
        configurable:false
    });
}
// addClass()
// first checks if the class name already exists, if not, it adds the class.
Object.defineProperty(Node.prototype,'addClass', {
    value: function(c) {
        if(this.className.indexOf(c)<0) {
            this.className=this.className+=' '+c;
        }
        return this;
    },
    writable:false,
    enumerable:false,
    configurable:false
});
// removeClass()
// removes the class and cleans up the className value by changing double 
// spacing to single spacing and trimming any leading or trailing spaces
Object.defineProperty(Node.prototype,'removeClass', {
    value: function(c) {
        this.className=this.className.replace(c,'').replace('  ',' ').trim();
        return this;
    },
    writable:false,
    enumerable:false,
    configurable:false
});

Now you can call myElement.removeClass('myClass')

or chain it: myElement.removeClass("oldClass").addClass("newClass");

How do you remove the title text from the Android ActionBar?

I'm very new to Android so correct me if I'm wrong, but I think if you decide to use navigation tabs on the Action Bar, they seemed to not be completely left aligned because the title text color is only transparent and hasn't gone away.

<style name="CustomActionBarStyle" parent="@android:style/Widget.Holo.ActionBar">
     <item name="android:displayOptions">useLogo|showHome</item>
</style>

worked for me.

JQuery .each() backwards

I prefer creating a reverse plug-in eg

jQuery.fn.reverse = function(fn) {       
   var i = this.length;

   while(i--) {
       fn.call(this[i], i, this[i])
   }
};

Usage eg:

$('#product-panel > div').reverse(function(i, e) {
    alert(i);
    alert(e);
});

PHP using Gettext inside <<<EOF string

As far as I can see in the manual, it is not possible to call functions inside HEREDOC strings. A cumbersome way would be to prepare the words beforehand:

<?php

    $world = _("World");

    $str = <<<EOF
    <p>Hello</p>
    <p>$world</p>
EOF;
    echo $str;
?>

a workaround idea that comes to mind is building a class with a magic getter method.

You would declare a class like this:

class Translator
{
 public function __get($name) {
  return _($name); // Does the gettext lookup
  }
 }

Initialize an object of the class at some point:

  $translate = new Translator();

You can then use the following syntax to do a gettext lookup inside a HEREDOC block:

    $str = <<<EOF
    <p>Hello</p>
    <p>{$translate->World}</p>
EOF;
    echo $str;
?>

$translate->World will automatically be translated to the gettext lookup thanks to the magic getter method.

To use this method for words with spaces or special characters (e.g. a gettext entry named Hello World!!!!!!, you will have to use the following notation:

 $translate->{"Hello World!!!!!!"}

This is all untested but should work.

Update: As @mario found out, it is possible to call functions from HEREDOC strings after all. I think using getters like this is a sleek solution, but using a direct function call may be easier. See the comments on how to do this.

Find a string by searching all tables in SQL Server Management Studio 2008

This was very helpful. I wanted to import this function to a Postgre SQL database. Thought i would share it with anyone who is interested. Will have them a few hours. Note: this function creates a list of SQL statements that can be copied and executed on the Postgre database. Maybe someone smarter then me can get Postgre to create and execute the statements all in one function.

CREATE OR REPLACE FUNCTION SearchAllTables(_search text) RETURNS TABLE( txt text ) as $funct$
    DECLARE __COUNT int;
    __SQL text;
BEGIN
    EXECUTE 'SELECT COUNT(0) FROM INFORMATION_SCHEMA.COLUMNS
                    WHERE    DATA_TYPE = ''text'' 
                    AND          table_schema = ''public'' ' INTO __COUNT;

    RETURN QUERY 
        SELECT CASE WHEN ROW_NUMBER() OVER (ORDER BY table_name) < __COUNT THEN 
            'SELECT ''' || table_name ||'.'|| column_name || ''' AS tbl, "'  || column_name || '" AS col FROM "public"."' || "table_name" || '" WHERE "'|| "column_name" || '" ILIKE ''%' || _search  || '%'' UNION ALL' 
            ELSE 
            'SELECT ''' || table_name ||'.'|| column_name || ''' AS tbl, "'  || column_name || '" AS col FROM "public"."' || "table_name" || '" WHERE "'|| "column_name" || '" ILIKE ''%' || _search  || '%'''
        END AS txt

                    FROM     INFORMATION_SCHEMA.COLUMNS
                    WHERE    DATA_TYPE = 'text' 
                    AND          table_schema = 'public';
END
$funct$ LANGUAGE plpgsql;

Android Starting Service at Boot Time , How to restart service class after device Reboot?

Most the solutions posted here are missing an important piece: doing it without a wake lock runs the risk of your Service getting killed before it is finished processing. Saw this solution in another thread, answering here as well.

Since WakefulBroadcastReceiver is deprecated in api 26 it is recommended for API Levels below 26

You need to obtain a wake lock . Luckily, the Support library gives us a class to do this:

public class SimpleWakefulReceiver extends WakefulBroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        // This is the Intent to deliver to our service.
        Intent service = new Intent(context, SimpleWakefulService.class);

        // Start the service, keeping the device awake while it is launching.
        Log.i("SimpleWakefulReceiver", "Starting service @ " + SystemClock.elapsedRealtime());
        startWakefulService(context, service);
    }
}

then, in your Service, make sure to release the wake lock:

    @Override
    protected void onHandleIntent(Intent intent) {
        // At this point SimpleWakefulReceiver is still holding a wake lock
        // for us.  We can do whatever we need to here and then tell it that
        // it can release the wakelock.

...
        Log.i("SimpleWakefulReceiver", "Completed service @ " + SystemClock.elapsedRealtime());
        SimpleWakefulReceiver.completeWakefulIntent(intent);
    }

Don't forget to add the WAKE_LOCK permission and register your receiver in the manifest:

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

...

<service android:name=".SimpleWakefulReceiver">
    <intent-filter>
        <action android:name="com.example.SimpleWakefulReceiver"/>
    </intent-filter>
</service>

Gradle store on local file system

On my windows machine with "Buildship 2.0.2" plugin installed in eclipse, dependencies are stored :

$USER_HOME.gradle\caches\modules-2\files-2.1

How do I download a binary file over HTTP?

Expanding on Dejw's answer (edit2):

File.open(filename,'w'){ |f|
  uri = URI.parse(url)
  Net::HTTP.start(uri.host,uri.port){ |http| 
    http.request_get(uri.path){ |res| 
      res.read_body{ |seg|
        f << seg
#hack -- adjust to suit:
        sleep 0.005 
      }
    }
  }
}

where filename and url are strings.

The sleep command is a hack that can dramatically reduce CPU usage when the network is the limiting factor. Net::HTTP doesn't wait for the buffer (16kB in v1.9.2) to fill before yielding, so the CPU busies itself moving small chunks around. Sleeping for a moment gives the buffer a chance to fill between writes, and CPU usage is comparable to a curl solution, 4-5x difference in my application. A more robust solution might examine progress of f.pos and adjust the timeout to target, say, 95% of the buffer size -- in fact that's how I got the 0.005 number in my example.

Sorry, but I don't know a more elegant way of having Ruby wait for the buffer to fill.

Edit:

This is a version that automatically adjusts itself to keep the buffer just at or below capacity. It's an inelegant solution, but it seems to be just as fast, and to use as little CPU time, as it's calling out to curl.

It works in three stages. A brief learning period with a deliberately long sleep time establishes the size of a full buffer. The drop period reduces the sleep time quickly with each iteration, by multiplying it by a larger factor, until it finds an under-filled buffer. Then, during the normal period, it adjusts up and down by a smaller factor.

My Ruby's a little rusty, so I'm sure this can be improved upon. First of all, there's no error handling. Also, maybe it could be separated into an object, away from the downloading itself, so that you'd just call autosleep.sleep(f.pos) in your loop? Even better, Net::HTTP could be changed to wait for a full buffer before yielding :-)

def http_to_file(filename,url,opt={})
  opt = {
    :init_pause => 0.1,    #start by waiting this long each time
                           # it's deliberately long so we can see 
                           # what a full buffer looks like
    :learn_period => 0.3,  #keep the initial pause for at least this many seconds
    :drop => 1.5,          #fast reducing factor to find roughly optimized pause time
    :adjust => 1.05        #during the normal period, adjust up or down by this factor
  }.merge(opt)
  pause = opt[:init_pause]
  learn = 1 + (opt[:learn_period]/pause).to_i
  drop_period = true
  delta = 0
  max_delta = 0
  last_pos = 0
  File.open(filename,'w'){ |f|
    uri = URI.parse(url)
    Net::HTTP.start(uri.host,uri.port){ |http|
      http.request_get(uri.path){ |res|
        res.read_body{ |seg|
          f << seg
          delta = f.pos - last_pos
          last_pos += delta
          if delta > max_delta then max_delta = delta end
          if learn <= 0 then
            learn -= 1
          elsif delta == max_delta then
            if drop_period then
              pause /= opt[:drop_factor]
            else
              pause /= opt[:adjust]
            end
          elsif delta < max_delta then
            drop_period = false
            pause *= opt[:adjust]
          end
          sleep(pause)
        }
      }
    }
  }
end

How to get content body from a httpclient call?

If you are not wanting to use async you can add .Result to force the code to execute synchronously:

private string GetResponseString(string text)
{
    var httpClient = new HttpClient();

    var parameters = new Dictionary<string, string>();
    parameters["text"] = text;

    var response = httpClient.PostAsync(BaseUri, new FormUrlEncodedContent(parameters)).Result;
    var contents = response.Content.ReadAsStringAsync().Result;

    return contents;
 }

When are static variables initialized?

static variable

It is a variable which belongs to the class and not to object(instance)
Static variables are initialized only once , at the start of the execution(when the Classloader load the class for the first time) .
These variables will be initialized first, before the initialization of any instance variables
A single copy to be shared by all instances of the class
A static variable can be accessed directly by the class name and doesn’t need any object

How to get ID of the last updated row in MySQL?

This is officially simple but remarkably counter-intuitive. If you're doing:

update users set status = 'processing' where status = 'pending'
limit 1

Change it to this:

update users set status = 'processing' where status = 'pending'
and last_insert_id(user_id) 
limit 1

The addition of last_insert_id(user_id) in the where clause is telling MySQL to set its internal variable to the ID of the found row. When you pass a value to last_insert_id(expr) like this, it ends up returning that value, which in the case of IDs like here is always a positive integer and therefore always evaluates to true, never interfering with the where clause. This only works if some row was actually found, so remember to check affected rows. You can then get the ID in multiple ways.

MySQL last_insert_id()

You can generate sequences without calling LAST_INSERT_ID(), but the utility of using the function this way is that the ID value is maintained in the server as the last automatically generated value. It is multi-user safe because multiple clients can issue the UPDATE statement and get their own sequence value with the SELECT statement (or mysql_insert_id()), without affecting or being affected by other clients that generate their own sequence values.

MySQL mysql_insert_id()

Returns the value generated for an AUTO_INCREMENT column by the previous INSERT or UPDATE statement. Use this function after you have performed an INSERT statement into a table that contains an AUTO_INCREMENT field, or have used INSERT or UPDATE to set a column value with LAST_INSERT_ID(expr).

The reason for the differences between LAST_INSERT_ID() and mysql_insert_id() is that LAST_INSERT_ID() is made easy to use in scripts while mysql_insert_id() tries to provide more exact information about what happens to the AUTO_INCREMENT column.

PHP mysqli_insert_id()

Performing an INSERT or UPDATE statement using the LAST_INSERT_ID() function will also modify the value returned by the mysqli_insert_id() function.

Putting it all together:

$affected_rows = DB::getAffectedRows("
    update users set status = 'processing' 
    where status = 'pending' and last_insert_id(user_id) 
    limit 1"
);
if ($affected_rows) {
    $user_id = DB::getInsertId();
}

(FYI that DB class is here.)

How to get request url in a jQuery $.get/ajax request

Since jQuery.get is just a shorthand for jQuery.ajax, another way would be to use the latter one's context option, as stated in the documentation:

The this reference within all callbacks is the object in the context option passed to $.ajax in the settings; if context is not specified, this is a reference to the Ajax settings themselves.

So you would use

$.ajax('http://www.example.org', {
  dataType: 'xml',
  data: {'a':1,'b':2,'c':3},
  context: {
    url: 'http://www.example.org'
  }
}).done(function(xml) {alert(this.url});

Constructor of an abstract class in C#

Normally constructors involve initializing the members of an object being created. In concept of inheritance, typically each class constructor in the inheritance hierarchy, is responsible for instantiating its own member variables. This makes sense because instantiation has to be done where the variables are defined.

Since an abstract class is not completely abstract (unlike interfaces), it is mix of both abstract and concrete members, and the members which are not abstract are needed to be initialized, which is done in abstract class's constructors, it is necessary to have constructors in the abstract class. Off course the abstract class's constructors can only be called from the constructors of derived class.

Oracle REPLACE() function isn't handling carriage-returns & line-feeds

Are you sure your newline is not CHR(13) + CHR(10), in which case, you are ending up with CHR(13) + '_', which might still look like a newline?

Try REPLACE(col_name, CHR(13) + CHR(10), '')

Multidimensional arrays in Swift

For future readers, here is an elegant solution(5x5):

var matrix = [[Int]](repeating: [Int](repeating: 0, count: 5), count: 5)

and a dynamic approach:

var matrix = [[Int]]() // creates an empty matrix
var row = [Int]() // fill this row
matrix.append(row) // add this row

Location of GlassFish Server Logs

In general the logs are in /YOUR_GLASSFISH_INSTALL/glassfish/domains/domain1/logs/.

In NetBeans go to the "Services" tab open "Servers", right-click on your Glassfish instance and click "View Domain Server Log".

If this doesn't work right-click on the Glassfish instance and click "Properties", you can see the folder with the domains under "Domains folder". Go to this folder -> your-domain -> logs

If the server is already running you should see an Output tab in NetBeans which is named similar to GlassFish Server x.x.x

You can also use cat or tail -F on /YOUR_GLASSFISH_INSTALL/glassfish/domains/domain1/logs/server.log. If you are using a different domain then domain1 you have to adjust the path for that.

onchange event on input type=range is not triggering in firefox while dragging

Yet another approach - just set a flag on an element signaling which type of event should be handled:

function setRangeValueChangeHandler(rangeElement, handler) {
    rangeElement.oninput = (event) => {
        handler(event);
        // Save flag that we are using onInput in current browser
        event.target.onInputHasBeenCalled = true;
    };

    rangeElement.onchange = (event) => {
        // Call only if we are not using onInput in current browser
        if (!event.target.onInputHasBeenCalled) {
            handler(event);
        }
    };
}

php_network_getaddresses: getaddrinfo failed: Name or service not known

$url = "http://user:[email protected]/abc.php?var1=def";
$contents = file_get_contents($url);
echo $contents;

Does JavaScript have a method like "range()" to generate a range within the supplied bounds?

Here's my 2 cents:

function range(start, count) {
  return Array.apply(0, Array(count))
    .map((element, index) => index + start);
}

Given URL is not allowed by the Application configuration Facebook application error

I have a website with facebook login.
It has been stable and working for months. No code change has happened for weeks. Then, suddenly, the facebook login gives an error message:

Error
Given URL is not allowed by the Application configuration.: One or more of the given URLs is not allowed by the App's settings. It must match the Website URL or Canvas URL, or the domain must be a subdomain of one of the App's domains.

After debugging "for awhile", I reset my facebook app secret and it started to work again!

Pro JavaScript programmer interview questions (with answers)

Ask them how they ensure their pages continue to be usable when the user has JavaScript turned off or JavaScript isn't available.

There's no One True Answer, but you're fishing for an answer talking about some strategies for Progressive Enhancement.

Progressive Enhancement consists of the following core principles:

basic content should be accessible to all browsers

basic functionality should be accessible to all browsers

sparse, semantic markup contains all content

enhanced layout is provided by externally linked CSS

enhanced behavior is provided by [[Unobtrusive JavaScript|unobtrusive]], externally linked JavaScript

end user browser preferences are respected

Java Read Large Text File With 70million line of text

I actually did a research in this topic for months in my free time and came up with a benchmark and here is a code to benchmark all the different ways to read a File line by line.The individual performance may vary based on the underlying system. I ran on a windows 10 Java 8 Intel i5 HP laptop:Here is the code.

import java.io.*;
import java.nio.channels.Channels;
import java.nio.channels.FileChannel;
import java.nio.file.Files;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.regex.Pattern;
import java.util.stream.Stream;

public class ReadComplexDelimitedFile {
    private static long total = 0;
    private static final Pattern FIELD_DELIMITER_PATTERN = Pattern.compile("\\^\\|\\^");

    @SuppressWarnings("unused")
    private void readFileUsingScanner() {

        String s;
        try (Scanner stdin = new Scanner(new File(this.getClass().getResource("input.txt").getPath()))) {
            while (stdin.hasNextLine()) {
                s = stdin.nextLine();
                String[] fields = FIELD_DELIMITER_PATTERN.split(s, 0);
                total = total + fields.length;
            }
        } catch (Exception e) {
            System.err.println("Error");
        }

    }

    //Winner
    private void readFileUsingCustomBufferedReader() {

        try (CustomBufferedReader stdin = new CustomBufferedReader(new FileReader(new File(this.getClass().getResource("input.txt").getPath())))) {
            String s;
            while ((s = stdin.readLine()) != null) {
                String[] fields = FIELD_DELIMITER_PATTERN.split(s, 0);
                total += fields.length;
            }
        } catch (Exception e) {
            System.err.println("Error");
        }

    }


    private void readFileUsingBufferedReader() {

        try (BufferedReader stdin = new BufferedReader(new FileReader(new File(this.getClass().getResource("input.txt").getPath())))) {
            String s;
            while ((s = stdin.readLine()) != null) {
                String[] fields = FIELD_DELIMITER_PATTERN.split(s, 0);
                total += fields.length;
            }
        } catch (Exception e) {
            System.err.println("Error");
        }
    }

    private void readFileUsingLineReader() {

        try (LineNumberReader stdin = new LineNumberReader(new FileReader(new File(this.getClass().getResource("input.txt").getPath())))) {
            String s;
            while ((s = stdin.readLine()) != null) {
                String[] fields = FIELD_DELIMITER_PATTERN.split(s, 0);
                total += fields.length;
            }
        } catch (Exception e) {
            System.err.println("Error");
        }
    }

    private void readFileUsingStreams() {

        try (Stream<String> stream = Files.lines((new File(this.getClass().getResource("input.txt").getPath())).toPath())) {
            total += stream.mapToInt(s -> FIELD_DELIMITER_PATTERN.split(s, 0).length).sum();
        } catch (IOException e1) {
            e1.printStackTrace();
        }
    }


    private void readFileUsingBufferedReaderFileChannel() {
        try (FileInputStream fis = new FileInputStream(this.getClass().getResource("input.txt").getPath())) {
            try (FileChannel inputChannel = fis.getChannel()) {
                try (CustomBufferedReader stdin = new CustomBufferedReader(Channels.newReader(inputChannel, "UTF-8"))) {
                    String s;
                    while ((s = stdin.readLine()) != null) {
                        String[] fields = FIELD_DELIMITER_PATTERN.split(s, 0);
                        total = total + fields.length;
                    }
                }
            } catch (Exception e) {
                System.err.println("Error");
            }
        } catch (Exception e) {
            System.err.println("Error");
        }

    }


    public static void main(String args[]) {
        //JVM wamrup
        for (int i = 0; i < 100000; i++) {
            total += i;
        }
        // We know scanner is slow-Still warming up
        ReadComplexDelimitedFile readComplexDelimitedFile = new ReadComplexDelimitedFile();
        List<Long> longList = new ArrayList<>(50);
        for (int i = 0; i < 50; i++) {
            total = 0;
            long startTime = System.nanoTime();
            //readComplexDelimitedFile.readFileUsingScanner();
            long stopTime = System.nanoTime();
            long timeDifference = stopTime - startTime;
            longList.add(timeDifference);

        }
        System.out.println("Time taken for readFileUsingScanner");
        longList.forEach(System.out::println);
        // Actual performance test starts here

        longList = new ArrayList<>(10);
        for (int i = 0; i < 10; i++) {
            total = 0;
            long startTime = System.nanoTime();
            readComplexDelimitedFile.readFileUsingBufferedReaderFileChannel();
            long stopTime = System.nanoTime();
            long timeDifference = stopTime - startTime;
            longList.add(timeDifference);

        }
        System.out.println("Time taken for readFileUsingBufferedReaderFileChannel");
        longList.forEach(System.out::println);
        longList.clear();
        for (int i = 0; i < 10; i++) {
            total = 0;
            long startTime = System.nanoTime();
            readComplexDelimitedFile.readFileUsingBufferedReader();
            long stopTime = System.nanoTime();
            long timeDifference = stopTime - startTime;
            longList.add(timeDifference);

        }
        System.out.println("Time taken for readFileUsingBufferedReader");
        longList.forEach(System.out::println);
        longList.clear();
        for (int i = 0; i < 10; i++) {
            total = 0;
            long startTime = System.nanoTime();
            readComplexDelimitedFile.readFileUsingStreams();
            long stopTime = System.nanoTime();
            long timeDifference = stopTime - startTime;
            longList.add(timeDifference);

        }
        System.out.println("Time taken for readFileUsingStreams");
        longList.forEach(System.out::println);
        longList.clear();
        for (int i = 0; i < 10; i++) {
            total = 0;
            long startTime = System.nanoTime();
            readComplexDelimitedFile.readFileUsingCustomBufferedReader();
            long stopTime = System.nanoTime();
            long timeDifference = stopTime - startTime;
            longList.add(timeDifference);

        }
        System.out.println("Time taken for readFileUsingCustomBufferedReader");
        longList.forEach(System.out::println);
        longList.clear();
        for (int i = 0; i < 10; i++) {
            total = 0;
            long startTime = System.nanoTime();
            readComplexDelimitedFile.readFileUsingLineReader();
            long stopTime = System.nanoTime();
            long timeDifference = stopTime - startTime;
            longList.add(timeDifference);

        }
        System.out.println("Time taken for readFileUsingLineReader");
        longList.forEach(System.out::println);

    }
}

I had to rewrite BufferedReader to avoid synchronized and a couple of boundary conditions that is not needed.(Atleast that's what I felt.It is not unit tested so use it at your own risk.)

import com.sun.istack.internal.NotNull;

import java.io.*;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;

/**
 * Reads text from a character-input stream, buffering characters so as to
 * provide for the efficient reading of characters, arrays, and lines.
 * <p>
 * <p> The buffer size may be specified, or the default size may be used.  The
 * default is large enough for most purposes.
 * <p>
 * <p> In general, each read request made of a Reader causes a corresponding
 * read request to be made of the underlying character or byte stream.  It is
 * therefore advisable to wrap a CustomBufferedReader around any Reader whose read()
 * operations may be costly, such as FileReaders and InputStreamReaders.  For
 * example,
 * <p>
 * <pre>
 * CustomBufferedReader in
 *   = new CustomBufferedReader(new FileReader("foo.in"));
 * </pre>
 * <p>
 * will buffer the input from the specified file.  Without buffering, each
 * invocation of read() or readLine() could cause bytes to be read from the
 * file, converted into characters, and then returned, which can be very
 * inefficient.
 * <p>
 * <p> Programs that use DataInputStreams for textual input can be localized by
 * replacing each DataInputStream with an appropriate CustomBufferedReader.
 *
 * @author Mark Reinhold
 * @see FileReader
 * @see InputStreamReader
 * @see java.nio.file.Files#newBufferedReader
 * @since JDK1.1
 */

public class CustomBufferedReader extends Reader {

    private final Reader in;

    private char cb[];
    private int nChars, nextChar;

    private static final int INVALIDATED = -2;
    private static final int UNMARKED = -1;
    private int markedChar = UNMARKED;
    private int readAheadLimit = 0; /* Valid only when markedChar > 0 */

    /**
     * If the next character is a line feed, skip it
     */
    private boolean skipLF = false;

    /**
     * The skipLF flag when the mark was set
     */
    private boolean markedSkipLF = false;

    private static int defaultCharBufferSize = 8192;
    private static int defaultExpectedLineLength = 80;
    private ReadWriteLock rwlock;


    /**
     * Creates a buffering character-input stream that uses an input buffer of
     * the specified size.
     *
     * @param in A Reader
     * @param sz Input-buffer size
     * @throws IllegalArgumentException If {@code sz <= 0}
     */
    public CustomBufferedReader(@NotNull final Reader in, int sz) {
        super(in);
        if (sz <= 0)
            throw new IllegalArgumentException("Buffer size <= 0");
        this.in = in;
        cb = new char[sz];
        nextChar = nChars = 0;
        rwlock = new ReentrantReadWriteLock();
    }

    /**
     * Creates a buffering character-input stream that uses a default-sized
     * input buffer.
     *
     * @param in A Reader
     */
    public CustomBufferedReader(@NotNull final Reader in) {
        this(in, defaultCharBufferSize);
    }


    /**
     * Fills the input buffer, taking the mark into account if it is valid.
     */
    private void fill() throws IOException {
        int dst;
        if (markedChar <= UNMARKED) {
            /* No mark */
            dst = 0;
        } else {
            /* Marked */
            int delta = nextChar - markedChar;
            if (delta >= readAheadLimit) {
                /* Gone past read-ahead limit: Invalidate mark */
                markedChar = INVALIDATED;
                readAheadLimit = 0;
                dst = 0;
            } else {
                if (readAheadLimit <= cb.length) {
                    /* Shuffle in the current buffer */
                    System.arraycopy(cb, markedChar, cb, 0, delta);
                    markedChar = 0;
                    dst = delta;
                } else {
                    /* Reallocate buffer to accommodate read-ahead limit */
                    char ncb[] = new char[readAheadLimit];
                    System.arraycopy(cb, markedChar, ncb, 0, delta);
                    cb = ncb;
                    markedChar = 0;
                    dst = delta;
                }
                nextChar = nChars = delta;
            }
        }

        int n;
        do {
            n = in.read(cb, dst, cb.length - dst);
        } while (n == 0);
        if (n > 0) {
            nChars = dst + n;
            nextChar = dst;
        }
    }

    /**
     * Reads a single character.
     *
     * @return The character read, as an integer in the range
     * 0 to 65535 (<tt>0x00-0xffff</tt>), or -1 if the
     * end of the stream has been reached
     * @throws IOException If an I/O error occurs
     */
    public char readChar() throws IOException {
        for (; ; ) {
            if (nextChar >= nChars) {
                fill();
                if (nextChar >= nChars)
                    return (char) -1;
            }
            return cb[nextChar++];
        }
    }

    /**
     * Reads characters into a portion of an array, reading from the underlying
     * stream if necessary.
     */
    private int read1(char[] cbuf, int off, int len) throws IOException {
        if (nextChar >= nChars) {
            /* If the requested length is at least as large as the buffer, and
               if there is no mark/reset activity, and if line feeds are not
               being skipped, do not bother to copy the characters into the
               local buffer.  In this way buffered streams will cascade
               harmlessly. */
            if (len >= cb.length && markedChar <= UNMARKED && !skipLF) {
                return in.read(cbuf, off, len);
            }
            fill();
        }
        if (nextChar >= nChars) return -1;
        int n = Math.min(len, nChars - nextChar);
        System.arraycopy(cb, nextChar, cbuf, off, n);
        nextChar += n;
        return n;
    }

    /**
     * Reads characters into a portion of an array.
     * <p>
     * <p> This method implements the general contract of the corresponding
     * <code>{@link Reader#read(char[], int, int) read}</code> method of the
     * <code>{@link Reader}</code> class.  As an additional convenience, it
     * attempts to read as many characters as possible by repeatedly invoking
     * the <code>read</code> method of the underlying stream.  This iterated
     * <code>read</code> continues until one of the following conditions becomes
     * true: <ul>
     * <p>
     * <li> The specified number of characters have been read,
     * <p>
     * <li> The <code>read</code> method of the underlying stream returns
     * <code>-1</code>, indicating end-of-file, or
     * <p>
     * <li> The <code>ready</code> method of the underlying stream
     * returns <code>false</code>, indicating that further input requests
     * would block.
     * <p>
     * </ul> If the first <code>read</code> on the underlying stream returns
     * <code>-1</code> to indicate end-of-file then this method returns
     * <code>-1</code>.  Otherwise this method returns the number of characters
     * actually read.
     * <p>
     * <p> Subclasses of this class are encouraged, but not required, to
     * attempt to read as many characters as possible in the same fashion.
     * <p>
     * <p> Ordinarily this method takes characters from this stream's character
     * buffer, filling it from the underlying stream as necessary.  If,
     * however, the buffer is empty, the mark is not valid, and the requested
     * length is at least as large as the buffer, then this method will read
     * characters directly from the underlying stream into the given array.
     * Thus redundant <code>CustomBufferedReader</code>s will not copy data
     * unnecessarily.
     *
     * @param cbuf Destination buffer
     * @param off  Offset at which to start storing characters
     * @param len  Maximum number of characters to read
     * @return The number of characters read, or -1 if the end of the
     * stream has been reached
     * @throws IOException If an I/O error occurs
     */
    public int read(char cbuf[], int off, int len) throws IOException {
        int n = read1(cbuf, off, len);
        if (n <= 0) return n;
        while ((n < len) && in.ready()) {
            int n1 = read1(cbuf, off + n, len - n);
            if (n1 <= 0) break;
            n += n1;
        }
        return n;
    }

    /**
     * Reads a line of text.  A line is considered to be terminated by any one
     * of a line feed ('\n'), a carriage return ('\r'), or a carriage return
     * followed immediately by a linefeed.
     *
     * @param ignoreLF If true, the next '\n' will be skipped
     * @return A String containing the contents of the line, not including
     * any line-termination characters, or null if the end of the
     * stream has been reached
     * @throws IOException If an I/O error occurs
     * @see java.io.LineNumberReader#readLine()
     */
    String readLine(boolean ignoreLF) throws IOException {
        StringBuilder s = null;
        int startChar;



        bufferLoop:
        for (; ; ) {

            if (nextChar >= nChars)
                fill();
            if (nextChar >= nChars) { /* EOF */
                if (s != null && s.length() > 0)
                    return s.toString();
                else
                    return null;
            }
            boolean eol = false;
            char c = 0;
            int i;

            /* Skip a leftover '\n', if necessary */



            charLoop:
            for (i = nextChar; i < nChars; i++) {
                c = cb[i];
                if ((c == '\n')) {
                    eol = true;
                    break charLoop;
                }
            }

            startChar = nextChar;
            nextChar = i;

            if (eol) {
                String str;
                if (s == null) {
                    str = new String(cb, startChar, i - startChar);
                } else {
                    s.append(cb, startChar, i - startChar);
                    str = s.toString();
                }
                nextChar++;
                return str;
            }

            if (s == null)
                s = new StringBuilder(defaultExpectedLineLength);
            s.append(cb, startChar, i - startChar);
        }
    }

    /**
     * Reads a line of text.  A line is considered to be terminated by any one
     * of a line feed ('\n'), a carriage return ('\r'), or a carriage return
     * followed immediately by a linefeed.
     *
     * @return A String containing the contents of the line, not including
     * any line-termination characters, or null if the end of the
     * stream has been reached
     * @throws IOException If an I/O error occurs
     * @see java.nio.file.Files#readAllLines
     */
    public String readLine() throws IOException {
        return readLine(false);
    }

    /**
     * Skips characters.
     *
     * @param n The number of characters to skip
     * @return The number of characters actually skipped
     * @throws IllegalArgumentException If <code>n</code> is negative.
     * @throws IOException              If an I/O error occurs
     */
    public long skip(long n) throws IOException {
        if (n < 0L) {
            throw new IllegalArgumentException("skip value is negative");
        }
        rwlock.readLock().lock();
            long r = n;
            try{
            while (r > 0) {
                if (nextChar >= nChars)
                    fill();
                if (nextChar >= nChars) /* EOF */
                    break;
                if (skipLF) {
                    skipLF = false;
                    if (cb[nextChar] == '\n') {
                        nextChar++;
                    }
                }
                long d = nChars - nextChar;
                if (r <= d) {
                    nextChar += r;
                    r = 0;
                    break;
                } else {
                    r -= d;
                    nextChar = nChars;
                }
            }
        } finally {
            rwlock.readLock().unlock();
        }
        return n - r;
    }

    /**
     * Tells whether this stream is ready to be read.  A buffered character
     * stream is ready if the buffer is not empty, or if the underlying
     * character stream is ready.
     *
     * @throws IOException If an I/O error occurs
     */
    public boolean ready() throws IOException {
        rwlock.readLock().lock();
        try {
            /*
             * If newline needs to be skipped and the next char to be read
             * is a newline character, then just skip it right away.
             */
            if (skipLF) {
                /* Note that in.ready() will return true if and only if the next
                 * read on the stream will not block.
                 */
                if (nextChar >= nChars && in.ready()) {
                    fill();
                }
                if (nextChar < nChars) {
                    if (cb[nextChar] == '\n')
                        nextChar++;
                    skipLF = false;
                }
            }
        } finally {
            rwlock.readLock().unlock();
        }
        return (nextChar < nChars) || in.ready();

    }

    /**
     * Tells whether this stream supports the mark() operation, which it does.
     */
    public boolean markSupported() {
        return true;
    }

    /**
     * Marks the present position in the stream.  Subsequent calls to reset()
     * will attempt to reposition the stream to this point.
     *
     * @param readAheadLimit Limit on the number of characters that may be
     *                       read while still preserving the mark. An attempt
     *                       to reset the stream after reading characters
     *                       up to this limit or beyond may fail.
     *                       A limit value larger than the size of the input
     *                       buffer will cause a new buffer to be allocated
     *                       whose size is no smaller than limit.
     *                       Therefore large values should be used with care.
     * @throws IllegalArgumentException If {@code readAheadLimit < 0}
     * @throws IOException              If an I/O error occurs
     */
    public void mark(int readAheadLimit) throws IOException {
        if (readAheadLimit < 0) {
            throw new IllegalArgumentException("Read-ahead limit < 0");
        }
        rwlock.readLock().lock();
        try {
            this.readAheadLimit = readAheadLimit;
            markedChar = nextChar;
            markedSkipLF = skipLF;
        } finally {
            rwlock.readLock().unlock();
        }
    }

    /**
     * Resets the stream to the most recent mark.
     *
     * @throws IOException If the stream has never been marked,
     *                     or if the mark has been invalidated
     */
    public void reset() throws IOException {
        rwlock.readLock().lock();
        try {
            if (markedChar < 0)
                throw new IOException((markedChar == INVALIDATED)
                        ? "Mark invalid"
                        : "Stream not marked");
            nextChar = markedChar;
            skipLF = markedSkipLF;
        } finally {
            rwlock.readLock().unlock();
        }
    }

    public void close() throws IOException {
        rwlock.readLock().lock();
        try {
            in.close();
        } finally {
            cb = null;
            rwlock.readLock().unlock();
        }

    }

    public Stream<String> lines() {
        Iterator<String> iter = new Iterator<String>() {
            String nextLine = null;

            @Override
            public boolean hasNext() {
                if (nextLine != null) {
                    return true;
                } else {
                    try {
                        nextLine = readLine();
                        return (nextLine != null);
                    } catch (IOException e) {
                        throw new UncheckedIOException(e);
                    }
                }
            }

            @Override
            public String next() {
                if (nextLine != null || hasNext()) {
                    String line = nextLine;
                    nextLine = null;
                    return line;
                } else {
                    throw new NoSuchElementException();
                }
            }
        };
        return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
                iter, Spliterator.ORDERED | Spliterator.NONNULL), false);
    }
}

And now the results:

Time taken for readFileUsingBufferedReaderFileChannel 2902690903 1845190694 1894071377 1815161868 1861056735 1867693540 1857521371 1794176251 1768008762 1853089582

Time taken for readFileUsingBufferedReader 2022837353 1925901163 1802266711 1842689572 1899984555 1843101306 1998642345 1821242301 1820168806 1830375108

Time taken for readFileUsingStreams 1992855461 1930827034 1850876033 1843402533 1800378283 1863581324 1810857226 1798497108 1809531144 1796345853

Time taken for readFileUsingCustomBufferedReader 1759732702 1765987214 1776997357 1772999486 1768559162 1755248431 1744434555 1750349867 1740582606 1751390934

Time taken for readFileUsingLineReader 1845307174 1830950256 1829847321 1828125293 1827936280 1836947487 1832186310 1820276327 1830157935 1829171481

Process finished with exit code 0

Inference: The test was run on a 200 MB file. The test was repeated several times. The data looked like this

Start Date^|^Start Time^|^End Date^|^End Time^|^Event Title ^|^All Day Event^|^No End Time^|^Event Description^|^Contact ^|^Contact Email^|^Contact Phone^|^Location^|^Category^|^Mandatory^|^Registration^|^Maximum^|^Last Date To Register
9/5/2011^|^3:00:00 PM^|^9/5/2011^|^^|^Social Studies Dept. Meeting^|^N^|^Y^|^Department meeting^|^Chris Gallagher^|^[email protected]^|^814-555-5179^|^High School^|^2^|^N^|^N^|^25^|^9/2/2011

Bottomline not much difference between BufferedReader and my CustomReader and it is very miniscule and hence you can use this to read your file.

Trust me you don't have to break your head.use BufferedReader with readLine,it is properly tested.At worst if you feel you can improve it just override and change it to StringBuilder instead of StringBuffer just to shave off half a second

Leave only two decimal places after the dot

// just two decimal places
String.Format("{0:0.00}", 123.4567);      // "123.46"
String.Format("{0:0.00}", 123.4);         // "123.40"
String.Format("{0:0.00}", 123.0);         // "123.00"

http://www.csharp-examples.net/string-format-double/

edit

No idea why they used "String" instead of "string", but the rest is correct.

How to create XML file with specific structure in Java

You can use the JDOM library in Java. Define your tags as Element objects, document your elements with Document Class, and build your xml file with SAXBuilder. Try this example:

//Root Element
Element root=new Element("CONFIGURATION");
Document doc=new Document();
//Element 1
Element child1=new Element("BROWSER");
//Element 1 Content
child1.addContent("chrome");
//Element 2
Element child2=new Element("BASE");
//Element 2 Content
child2.addContent("http:fut");
//Element 3
Element child3=new Element("EMPLOYEE");
//Element 3 --> In this case this element has another element with Content
child3.addContent(new Element("EMP_NAME").addContent("Anhorn, Irene"));

//Add it in the root Element
root.addContent(child1);
root.addContent(child2);
root.addContent(child3);
//Define root element like root
doc.setRootElement(root);
//Create the XML
XMLOutputter outter=new XMLOutputter();
outter.setFormat(Format.getPrettyFormat());
outter.output(doc, new FileWriter(new File("myxml.xml")));

Case vs If Else If: Which is more efficient?

I believe because cases must be constant values, the switch statement does the equivelent of a goto, so based on the value of the variable it jumps to the right case, whereas in the if/then statement it must evaluate each expression.

How to "flatten" a multi-dimensional array to simple one in PHP?

// $array = your multidimensional array

$flat_array = array();

foreach(new RecursiveIteratorIterator(new RecursiveArrayIterator($array)) as $k=>$v){

$flat_array[$k] = $v;

}

Also documented: http://www.phpro.org/examples/Flatten-Array.html

Command to get latest Git commit hash from a branch

Note that when using "git log -n 1 [branch_name]" option. -n returns only one line of log but order in which this is returned is not guaranteed. Following is extract from git-log man page

.....
.....
Commit Limiting

Besides specifying a range of commits that should be listed using the special notations explained in the     description, additional commit limiting may be applied.

Using more options generally further limits the output (e.g. --since=<date1> limits to commits newer than <date1>, and using it with --grep=<pattern> further limits to commits whose log message has a line that matches <pattern>), unless otherwise noted.

Note that these are applied before commit ordering and formatting options, such as --reverse.

-<number>
-n <number>
.....
.....

How to display image from database using php

put you $image in img tag of html

try this

echo '<img src="your_path_to_image/'.$image.'" />';

instead of

print $image;

your_path_to_image would be absolute path of your image folder like eg: /home/son/public_html/images/ or as your folder structure on server.

Update 2 :

if your image is resides in the same folder where this page file is exists
you can user this

echo '<img src="'.$image.'" />';

Import Script from a Parent Directory

From the docs:

from .. import scriptA

You can do this in packages, but not in scripts you run directly. From the link above:

Note that both explicit and implicit relative imports are based on the name of the current module. Since the name of the main module is always "__main__", modules intended for use as the main module of a Python application should always use absolute imports.

If you create a script that imports A.B.B, you won't receive the ValueError.

The difference between "require(x)" and "import x"

Let me give an example for Including express module with require & import

-require

var express = require('express');

-import

import * as  express from 'express';

So after using any of the above statement we will have a variable called as 'express' with us. Now we can define 'app' variable as,

var app = express();

So we use 'require' with 'CommonJS' and 'import' with 'ES6'.

For more info on 'require' & 'import', read through below links.

require - Requiring modules in Node.js: Everything you need to know

import - An Update on ES6 Modules in Node.js

Paused in debugger in chrome?

And there is some options below ,if you have checked some,when the condition is active,the breakpoint debugger also active

og:type and valid values : constantly being parsed as og:type=website

Make sure your article:author data is a Facebook author URL. Unfortunately, that conflicts with what Pinterest is expecting. It's the best thing about standards, there are so many ways to implement them!

<meta property="article:author" content="https://www.facebook.com/mpatnode76">

But Pinterest wants to see something like this:

<meta property="article:author" content="Mike Patnode">

We ended up swapping the formats depending upon the user agent. Hopefully, that doesn't screw up your page cache. That fixed it for us.

Full disclosure. Found this here: https://surniaulula.com/2014/03/01/pinterest-articleauthor-incompatible-with-open-graph/

How to include a sub-view in Blade templates?

You can use the blade template engine:

@include('view.name')

'view.name' would live in your main views folder:

// for laravel 4.X
app/views/view/name.blade.php  

// for laravel 5.X
resources/views/view/name.blade.php

Another example

@include('hello.world');

would display the following view

// for laravel 4.X
app/views/hello/world.blade.php

// for laravel 5.X
resources/views/hello/world.blade.php

Another example

@include('some.directory.structure.foo');

would display the following view

// for Laravel 4.X
app/views/some/directory/structure/foo.blade.php

// for Laravel 5.X
resources/views/some/directory/structure/foo.blade.php

So basically the dot notation defines the directory hierarchy that your view is in, followed by the view name, relative to app/views folder for laravel 4.x or your resources/views folder in laravel 5.x

ADDITIONAL

If you want to pass parameters: @include('view.name', array('paramName' => 'value'))

You can then use the value in your views like so {{$paramName}}

How do I implement JQuery.noConflict() ?

It allows for you to give the jQuery variable a different name, and still use it:

<script type="text/javascript">
  $jq = $.noConflict();
  // Code that uses other library's $ can follow here.
  //use $jq for all calls to jQuery:
  $jq.ajax(...)
  $jq('selector')
</script>

How to run an awk commands in Windows?

Go to command windows (cmd) then type:

"c:\Progam Files(x86)\GnuWin32\bin\awk"

Count number of cells with any value (string or number) in a column in Google Docs Spreadsheet

An additional trick beside using =COUNTIF(...) and =COUNTA(...) is:

=COUNTBLANK(A2:C100)

That will count all the empty cells.

This is useful for:

empty cells that doesn't contain data
formula that return blank or null
survey with missing answer fields which can be used for diff criterias

How to tell whether a point is to the right or left side of a line

Here's a version, again using the cross product logic, written in Clojure.

(defn is-left? [line point]
  (let [[[x1 y1] [x2 y2]] (sort line)
        [x-pt y-pt] point]
    (> (* (- x2 x1) (- y-pt y1)) (* (- y2 y1) (- x-pt x1)))))

Example usage:

(is-left? [[-3 -1] [3 1]] [0 10])
true

Which is to say that the point (0, 10) is to the left of the line determined by (-3, -1) and (3, 1).

NOTE: This implementation solves a problem that none of the others (so far) does! Order matters when giving the points that determine the line. I.e., it's a "directed line", in a certain sense. So with the above code, this invocation also produces the result of true:

(is-left? [[3 1] [-3 -1]] [0 10])
true

That's because of this snippet of code:

(sort line)

Finally, as with the other cross product based solutions, this solution returns a boolean, and does not give a third result for collinearity. But it will give a result that makes sense, e.g.:

(is-left? [[1 1] [3 1]] [10 1])
false

IPC performance: Named Pipe vs Socket

One problem with sockets is that they do not have a way to flush the buffer. There is something called the Nagle algorithm which collects all data and flushes it after 40ms. So if it is responsiveness and not bandwidth you might be better off with a pipe.

You can disable the Nagle with the socket option TCP_NODELAY but then the reading end will never receive two short messages in one single read call.

So test it, i ended up with none of this and implemented memory mapped based queues with pthread mutex and semaphore in shared memory, avoiding a lot of kernel system calls (but today they aren't very slow anymore).

TypeError: p.easing[this.easing] is not a function

use the latest one for bootstrap 4 and above, this won't affect your UI

React.js create loop through Array

In CurrentGame component you need to change initial state because you are trying use loop for participants but this property is undefined that's why you get error.,

getInitialState: function(){
    return {
       data: {
          participants: [] 
       }
    };
},

also, as player in .map is Object you should get properties from it

this.props.data.participants.map(function(player) {
   return <li key={player.championId}>{player.summonerName}</li>
   // -------------------^^^^^^^^^^^---------^^^^^^^^^^^^^^
})

Example

How to get all elements by class name?

How to lose margin/padding in UITextView?

I would definitely avoid any answers involving hard-coded values, as the actual margins may change with user font-size settings, etc.

Here is @user1687195's answer, written without modifying the textContainer.lineFragmentPadding (because the docs state this is not the intended usage).

This works great for iOS 7 and later.

self.textView.textContainerInset = UIEdgeInsetsMake(
                                      0, 
                                      -self.textView.textContainer.lineFragmentPadding, 
                                      0, 
                                      -self.textView.textContainer.lineFragmentPadding);

This is effectively the same outcome, just a bit cleaner in that it doesn't misuse the lineFragmentPadding property.

How does the "view" method work in PyTorch?

I figured it out that x.view(-1, 16 * 5 * 5) is equivalent to x.flatten(1), where the parameter 1 indicates the flatten process starts from the 1st dimension(not flattening the 'sample' dimension) As you can see, the latter usage is semantically more clear and easier to use, so I prefer flatten().

Select the values of one property on all objects of an array in PowerShell

I think you might be able to use the ExpandProperty parameter of Select-Object.

For example, to get the list of the current directory and just have the Name property displayed, one would do the following:

ls | select -Property Name

This is still returning DirectoryInfo or FileInfo objects. You can always inspect the type coming through the pipeline by piping to Get-Member (alias gm).

ls | select -Property Name | gm

So, to expand the object to be that of the type of property you're looking at, you can do the following:

ls | select -ExpandProperty Name

In your case, you can just do the following to have a variable be an array of strings, where the strings are the Name property:

$objects = ls | select -ExpandProperty Name

Gridview row editing - dynamic binding to a DropDownList

You can use SelectedValue:

<EditItemTemplate>
    <asp:DropDownList ID="ddlPBXTypeNS"
                      runat="server"
                      Width="200px"
                      DataSourceID="YDS"
                      DataTextField="CaptionValue"
                      DataValueField="OID"
                      SelectedValue='<%# Bind("YourForeignKey") %>' />
    <asp:YourDataSource ID="YDS" ...../>
</EditItemTemplate>

How to get the server path to the web directory in Symfony2 from inside the controller?

For Symfony3 In your controller try

$request->server->get('DOCUMENT_ROOT').$request->getBasePath()

php timeout - set_time_limit(0); - don't work

I usually use set_time_limit(30) within the main loop (so each loop iteration is limited to 30 seconds rather than the whole script).

I do this in multiple database update scripts, which routinely take several minutes to complete but less than a second for each iteration - keeping the 30 second limit means the script won't get stuck in an infinite loop if I am stupid enough to create one.

I must admit that my choice of 30 seconds for the limit is somewhat arbitrary - my scripts could actually get away with 2 seconds instead, but I feel more comfortable with 30 seconds given the actual application - of course you could use whatever value you feel is suitable.

Hope this helps!

Reading serial data in realtime in Python

From the manual:

Possible values for the parameter timeout: … x set timeout to x seconds

and

readlines(sizehint=None, eol='\n') Read a list of lines, until timeout. sizehint is ignored and only present for API compatibility with built-in File objects.

Note that this function only returns on a timeout.

So your readlines will return at most every 2 seconds. Use read() as Tim suggested.

Initialize 2D array

How about something like this:

for (int row = 0; row < 3; row ++)
    for (int col = 0; col < 3; col++)
        table[row][col] = (char) ('1' + row * 3 + col);

The following complete Java program:

class Test {
    public static void main(String[] args) {
        char[][] table = new char[3][3];
        for (int row = 0; row < 3; row ++)
            for (int col = 0; col < 3; col++)
                table[row][col] = (char) ('1' + row * 3 + col);

        for (int row = 0; row < 3; row ++)
            for (int col = 0; col < 3; col++)
                System.out.println (table[row][col]);
    }
}

outputs:

This works because the digits in Unicode are consecutive starting at \u0030 (which is what you get from '0').

The expression '1' + row * 3 + col (where you vary row and col between 0 and 2 inclusive) simply gives you a character from 1 to 9.

Obviously, this won't give you the character 10 (since that's two characters) if you go further but it works just fine for the 3x3 case. You would have to change the method of generating the array contents at that point such as with something like:

String[][] table = new String[5][5];
for (int row = 0; row < 5; row ++)
    for (int col = 0; col < 5; col++)
        table[row][col] = String.format("%d", row * 5 + col + 1);

How to place a div on the right side with absolute position

Can you try the following:

float: right;

How to change default JRE for all Eclipse workspaces?

I have faced with the same issue. The resolve: - Window-->Preferences-->Java-->Installed JREs-->Add... - Right click on your project-->Build Path-->Configure Build Path-->Add library-->JRE system library-->next-->WorkSpace Default JRE

How to set DataGrid's row Background, based on a property value using data bindings

The same can be done without DataTrigger too:

 <DataGrid.RowStyle>
     <Style TargetType="DataGridRow">
         <Setter Property="Background" >
             <Setter.Value>
                 <Binding Path="State" Converter="{StaticResource BooleanToBrushConverter}">
                     <Binding.ConverterParameter>
                         <x:Array Type="SolidColorBrush">
                             <SolidColorBrush Color="{StaticResource RedColor}"/>
                             <SolidColorBrush Color="{StaticResource TransparentColor}"/>
                         </x:Array>
                     </Binding.ConverterParameter>
                 </Binding>
             </Setter.Value>
         </Setter>
     </Style>
 </DataGrid.RowStyle>

Where BooleanToBrushConverter is the following class:

public class BooleanToBrushConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        if (value == null)
            return Brushes.Transparent;

        Brush[] brushes = parameter as Brush[];
        if (brushes == null)
            return Brushes.Transparent;

        bool isTrue;
        bool.TryParse(value.ToString(), out isTrue);

        if (isTrue)
        {
            var brush =  (SolidColorBrush)brushes[0];
            return brush ?? Brushes.Transparent;
        }
        else
        {
            var brush = (SolidColorBrush)brushes[1];
            return brush ?? Brushes.Transparent;
        }
    }

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

how to run two commands in sudo?

If you know the root password, you can try

su -c "<command1> ; <command2>"

How to clear cache of Eclipse Indigo

I think you can find the answer you want in these two posts. They are mentioning Flash Builder, but essentially, the talk is about its Eclipse base.

Clear improperly cached compile errors in FlexBuilder: http://blog.aherrman.com/2010/05/clear-improperly-cached-compile-errors.html

How to fix Flash Builder broken workspace: http://va.lent.in/how-to-fix-flash-builder-broken-workspace/

Target Unreachable, identifier resolved to null in JSF 2.2

I solved this problem.

My Java version was the 1.6 and I found that was using 1.7 with CDI however after that I changed the Java version to 1.7 and import the package javax.faces.bean.ManagedBean and everything worked.

Thanks @PM77-1

How to Serialize a list in java?

List is just an interface. The question is: is your actual List implementation serializable? Speaking about the standard List implementations (ArrayList, LinkedList) from the Java run-time, most of them actually are already.

Hash Table/Associative Array in VBA

I think you are looking for the Dictionary object, found in the Microsoft Scripting Runtime library. (Add a reference to your project from the Tools...References menu in the VBE.)

It pretty much works with any simple value that can fit in a variant (Keys can't be arrays, and trying to make them objects doesn't make much sense. See comment from @Nile below.):

Dim d As dictionary
Set d = New dictionary

d("x") = 42
d(42) = "forty-two"
d(CVErr(xlErrValue)) = "Excel #VALUE!"
Set d(101) = New Collection

You can also use the VBA Collection object if your needs are simpler and you just want string keys.

I don't know if either actually hashes on anything, so you might want to dig further if you need hashtable-like performance. (EDIT: Scripting.Dictionary does use a hash table internally.)

Split string into array of characters?

the problem is that there is no built in method (or at least none of us could find one) to do this in vb. However, there is one to split a string on the spaces, so I just rebuild the string and added in spaces....

Private Function characterArray(ByVal my_string As String) As String()
  'create a temporary string to store a new string of the same characters with spaces
  Dim tempString As String = ""
  'cycle through the characters and rebuild my_string as a string with spaces 
  'and assign the result to tempString.  
  For Each c In my_string
     tempString &= c & " "
  Next
  'return return tempString as a character array.  
  Return tempString.Split()
End Function

Consider defining a bean of type 'service' in your configuration [Spring boot]

Even after doing all the method suggested, i was getting the same error. After trying hard, i got to know that hibernate's maven dependency was added in my pom.xml, as i removed it, application started successfully.

I removed this dependency:

<dependency> <groupId>org.hibernate.javax.persistence</groupId>
 <artifactId>hibernate-jpa-2.0-api</artifactId>
             <version>1.0.1.Final</version>
         </dependency>

Uncaught Error: SECURITY_ERR: DOM Exception 18 when I try to set a cookie

Faced with the same situation playing with Javascript webworkers. Unfortunately Chrome doesn't allow to access javascript workers stored in a local file.

One kind of workaround below using a local storage is to running Chrome with --allow-file-access-from-files (with s at the end), but only one instance of Chrome is allowed, which is not too convenient for me. For this reason i'm using Chrome Canary, with file access allowed.

BTW in Firefox there is no such an issue.

How to trigger event in JavaScript?

I searched for firing click, mousedown and mouseup event on mouseover using JavaScript. I found an answer provided by Juan Mendes. For the answer click here.

Click here is the live demo and below is the code:

function fireEvent(node, eventName) {
    // Make sure we use the ownerDocument from the provided node to avoid cross-window problems
    var doc;
    if (node.ownerDocument) {
        doc = node.ownerDocument;
    } else if (node.nodeType == 9) {
        // the node may be the document itself, nodeType 9 = DOCUMENT_NODE
        doc = node;
    } else {
        throw new Error("Invalid node passed to fireEvent: " + node.id);
    }

    if (node.dispatchEvent) {
        // Gecko-style approach (now the standard) takes more work
        var eventClass = "";

        // Different events have different event classes.
        // If this switch statement can't map an eventName to an eventClass,
        // the event firing is going to fail.
        switch (eventName) {
        case "click": // Dispatching of 'click' appears to not work correctly in Safari. Use 'mousedown' or 'mouseup' instead.
        case "mousedown":
        case "mouseup":
            eventClass = "MouseEvents";
            break;

        case "focus":
        case "change":
        case "blur":
        case "select":
            eventClass = "HTMLEvents";
            break;

        default:
            throw "fireEvent: Couldn't find an event class for event '" + eventName + "'.";
            break;
        }
        var event = doc.createEvent(eventClass);

        var bubbles = eventName == "change" ? false : true;
        event.initEvent(eventName, bubbles, true); // All events created as bubbling and cancelable.

        event.synthetic = true; // allow detection of synthetic events
        // The second parameter says go ahead with the default action
        node.dispatchEvent(event, true);
    } else if (node.fireEvent) {
        // IE-old school style
        var event = doc.createEventObject();
        event.synthetic = true; // allow detection of synthetic events
        node.fireEvent("on" + eventName, event);
    }
};

Command-line tool for finding out who is locking a file

Download Handle.

https://technet.microsoft.com/en-us/sysinternals/bb896655.aspx

If you want to find what program has a handle on a certain file, run this from the directory that Handle.exe is extracted to. Unless you've added Handle.exe to the PATH environment variable. And the file path is C:\path\path\file.txt", run this:

handle "C:\path\path\file.txt"

This will tell you what process(es) have the file (or folder) locked.

New lines inside paragraph in README.md

You can use a backslash at the end of a line.
So this:

a\
b\
c

will then look like:

a
b
c

Notice that there is no backslash at the end of the last line (after the 'c' character).

Best way to change font colour halfway through paragraph?

 will allow you to style text, but it adds no semantic content.

As you're emphasizing some text, it sounds like you'd be better served by wrapping the text in  and using CSS to change the color of the  element. For example:

CSS

.description {
  color: #fff;
}

.description em {
  color: #ffa500;
}

Markup

<p class="description">Lorem ipsum dolor sit amet, consectetur 
adipiscing elit. Sed hendrerit mollis varius. Etiam ornare placerat 
massa, <em>eget vulputate tellus fermentum.</em></p>

In fact, I'd go to great pains to avoid the  element, as it's completely meaningless to everything that doesn't render your style sheet (bots, screen readers, luddites who disable styles, parsers, etc.) or renders it in unexpected ways (personal style sheets). In many ways, it's no better than using the  element.

_x000D_

.description {_x000D_
  color: #000;_x000D_
}_x000D_
_x000D_
.description em {_x000D_
  color: #ffa500;_x000D_
}

_x000D_

<p class="description">Lorem ipsum dolor sit amet, consectetur _x000D_
adipiscing elit. Sed hendrerit mollis varius. Etiam ornare placerat _x000D_
massa, <em>eget vulputate tellus fermentum.</em></p>

_x000D_

heroku - how to see all the logs

You need to have some logs draining implemented and should be draining your logs there, to see all of the logs (manage historical logs as well):

First option - Splunk can be used: you can drain all your logs like:

heroku drains:add syslog+tls://splunk-server.com:514 -a app_name

And then login into your splunk server and search for any number of logs. I am using Splunk and this is working perfectly fine for me.

Second option - You can purchase add on to your App, like given below: (I haven't used these options, however these are the available ones).
- Timber.io
- Sumo Logic
- LogEnteries
- Log DNA
- Papertrail

You can also have a look at below options: If you want to have your logs in JSON format, as it will help if your are pushing your logs to external system like Splunk/ELK, it would become easy (performance wise also) to search in JSON.

https://github.com/goodeggs/heroku-log-normalizer

It is not having Readme.md, but some explanation is given at https://github.com/goodeggs/bites/issues/20

Lastly

And you can always use below command as mentioned by other users already:

The following command will tail the generating logs on heroku

heroku logs -t -a <app_name>

The following comand will show the 1000 number of lines of logs from heroku

heroku logs -n 1000 -a <app_name>

Note only 1500 latest lines of logs are available and rest of them gets deleted from heroku dyno.

How can I move HEAD back to a previous location? (Detached head) & Undo commits

The question can be read as:

I was in detached-state with HEAD at 23b6772 and typed git reset origin/master (because I wanted to squash). Now I've changed my mind, how do I go back to HEAD being at 23b6772?

The straightforward answer being: git reset 23b6772

But I hit this question because I got sick of typing (copy & pasting) commit hashes or its abbreviation each time I wanted to reference the previous HEAD and was Googling to see if there were any kind of shorthand.

It turns out there is!

git reset - (or in my case git cherry-pick -)

Which incidentally was the same as cd - to return to the previous current directory in *nix! So hurrah, I learned two things with one stone.

Android camera intent

I found a pretty simple way to do this. Use a button to open it using an on click listener to start the function openc(), like this:

String fileloc;
private void openc()
{
    Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    File f = null;
    try 
    {
        f = File.createTempFile("temppic",".jpg",getApplicationContext().getCacheDir());
        if (takePictureIntent.resolveActivity(getPackageManager()) != null)
        {               
            takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT,FileProvider.getUriForFile(profile.this, BuildConfig.APPLICATION_ID+".provider",f));
            fileloc = Uri.fromFile(f)+"";
            Log.d("texts", "openc: "+fileloc);
            startActivityForResult(takePictureIntent, 3);
        }
    } 
    catch (IOException e) 
    {
        e.printStackTrace();
    }
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) 
{
    super.onActivityResult(requestCode, resultCode, data);
    if(requestCode == 3 && resultCode == RESULT_OK) {
        Log.d("texts", "onActivityResult: "+fileloc);
        // fileloc is the uri of the file so do whatever with it
    }
}

You can do whatever you want with the uri location string. For instance, I send it to an image cropper to crop the image.

how to check for null with a ng-if values in a view with angularjs?

You can also use ng-template, I think that would be more efficient while run time :)

<div ng-if="!test.view; else somethingElse">1</div>
<ng-template #somethingElse>
    <div>2</div>
</ng-template>

Cheers

How to make "if not true condition"?

On Unix systems that supports it (not macOS it seems):

if getent passwd "$username" >/dev/null; then
    printf 'User %s exists\n' "$username"
else
    printf 'User %s does not exist\n' "$username"
fi

This has the advantage that it will query any directory service that may be in use (YP/NIS or LDAP etc.) and the local password database file.

The issue with grep -q "$username" /etc/passwd is that it will give a false positive when there is no such user, but something else matches the pattern. This could happen if there is a partial or exact match somewhere else in the file.

For example, in my passwd file, there is a line saying

build:*:21:21:base and xenocara build:/var/empty:/bin/ksh

This would provoke a valid match on things like cara and enoc etc., even though there are no such users on my system.

For a grep solution to be correct, you will need to properly parse the /etc/passwd file:

if cut -d ':' -f 1 /etc/passwd | grep -qxF "$username"; then
    # found
else
    # not found
fi

... or any other similar test against the first of the :-delimited fields.

Show values from a MySQL database table inside a HTML table on a webpage

First, connect to the database:

$conn=mysql_connect("hostname","username","password");
mysql_select_db("databasename",$conn);

You can use this to display a single record:

For example, if the URL was /index.php?sequence=123, the code below would select from the table, where the sequence = 123.

<?php
$sql="SELECT * from table where sequence = '".$_GET["sequence"]."' ";
$rs=mysql_query($sql,$conn) or die(mysql_error());
$result=mysql_fetch_array($rs);

echo '<table>
<tr>
<td>Forename</td>
<td>Surname</td>
</tr>
<tr>
<td>'.$result["forename"].'</td>
<td>'.$result["surname"].'</td>
</tr>
</table>';
?>

Or, if you want to list all values that match the criteria in a table:

<?php
echo '<table>
<tr>
<td>Forename</td>
<td>Surname</td>
</tr>';
$sql="SELECT * from table where sequence = '".$_GET["sequence"]."' ";
$rs=mysql_query($sql,$conn) or die(mysql_error());
while($result=mysql_fetch_array($rs))
{
echo '<tr>
<td>'.$result["forename"].'</td>
<td>'.$result["surname"].'</td>
</tr>';
}
echo '</table>';
?>

Generate 'n' unique random numbers within a range

You could use the random.sample function from the standard library to select k elements from a population:

import random
random.sample(range(low, high), n)

In case of a rather large range of possible numbers, you could use itertools.islice with an infinite random generator:

import itertools
import random

def random_gen(low, high):
    while True:
        yield random.randrange(low, high)

gen = random_gen(1, 100)
items = list(itertools.islice(gen, 10))  # Take first 10 random elements

After the question update it is now clear that you need n distinct (unique) numbers.

import itertools
import random

def random_gen(low, high):
    while True:
        yield random.randrange(low, high)

gen = random_gen(1, 100)

items = set()

# Try to add elem to set until set length is less than 10
for x in itertools.takewhile(lambda x: len(items) < 10, gen):
    items.add(x)

telnet to port 8089 correct command

I believe telnet 74.255.12.25 8089 . Why don't u try both

HTML table headers always visible at top of window when viewing a large table

If you're targeting modern css3 compliant browsers (Browser support: https://caniuse.com/#feat=css-sticky) you can use position:sticky, which doesn't require JS and won't break the table layout miss-aligning th and td of the same column. Nor does it require fixed column width to work properly.

Example for a single header row:

thead th
{
    position: sticky;
    top: 0px;
}

For theads with 1 or 2 rows, you can use something like this:

thead > :last-child th
{
    position: sticky;
    top: 30px; /* This is for all the the "th" elements in the second row, (in this casa is the last child element into the thead) */
}

thead > :first-child th
{
    position: sticky;
    top: 0px; /* This is for all the the "th" elements in the first child row */
}

You might need to play a bit with the top property of the last child changing the number of pixels to match the height of the first row (+ the margin + the border + the padding, if any), so the second row sticks just down bellow the first one.

Also both solutions work even if you have more than one table in the same page: the th element of each one starts to be sticky when its top position is the one indicated into the css definition and just disappear when all the table scrolls down. So if there are more tables all work beautifully the same way.

Why to use last-child before and first-child after in the css?

Because css rules are rendered by the browser in the same order as you write them into the css file and because of this if you have just 1 row into the thead element the first row is simultaneously the last row too and the first-child rule need to override the last-child one. If not you will have an offset of the row 30 px from the top margin which I suppose you don't want to.

A known problem of position: sticky is that it doesn't work on thead elements or table rows: you must target th elements. Hopping this issue will be solved on future browser versions.

Getting specified Node values from XML document

Just like you do for getting something from the CNode you also need to do for the ANode

XmlNodeList xnList = xml.SelectNodes("/Element[@*]");
foreach (XmlNode xn in xnList)
{
  XmlNode anode = xn.SelectSingleNode("ANode");
    if (anode!= null)
    {
        string id = anode["ID"].InnerText;
        string date = anode["Date"].InnerText;
        XmlNodeList CNodes = xn.SelectNodes("ANode/BNode/CNode");
        foreach (XmlNode node in CNodes)
        {
         XmlNode example = node.SelectSingleNode("Example");
         if (example != null)
         {
            string na = example["Name"].InnerText;
            string no = example["NO"].InnerText;
         }
        }
    }
}

Python: Writing to and Reading from serial port

a piece of code who work with python to read rs232 just in case somedoby else need it

ser = serial.Serial('/dev/tty.usbserial', 9600, timeout=0.5)
ser.write('*99C\r\n')
time.sleep(0.1)
ser.close()

Compare two objects with .equals() and == operator

Your class might implement the Comparable interface to achieve the same functionality. Your class should implement the compareTo() method declared in the interface.

public class MyClass implements Comparable<MyClass>{

    String a;

    public MyClass(String ab){
        a = ab;
    }

    // returns an int not a boolean
    public int compareTo(MyClass someMyClass){ 

        /* The String class implements a compareTo method, returning a 0 
           if the two strings are identical, instead of a boolean.
           Since 'a' is a string, it has the compareTo method which we call
           in MyClass's compareTo method.
        */

        return this.a.compareTo(someMyClass.a);

    }

    public static void main(String[] args){

        MyClass object1 = new MyClass("test");
        MyClass object2 = new MyClass("test");

        if(object1.compareTo(object2) == 0){
            System.out.println("true");
        }
        else{
            System.out.println("false");
        }
    }
}

Join two data frames, select all columns from one and some columns from the other

Not sure if the most efficient way, but this worked for me:

from pyspark.sql.functions import col

df1.alias('a').join(df2.alias('b'),col('b.id') == col('a.id')).select([col('a.'+xx) for xx in a.columns] + [col('b.other1'),col('b.other2')])

The trick is in:

[col('a.'+xx) for xx in a.columns] : all columns in a

[col('b.other1'),col('b.other2')] : some columns of b

How to set a session variable when clicking a <a> link

I had the same problem - i wanted to pass a parameter to another page by clicking a hyperlink and get the value to go to the next page (without using GET because the parameter is stored in the URL).

to those who don't understand why you would want to do this the answer is you dont want the user to see sensitive information or you dont want someone editing the GET.

well after scouring the internet it seemed it wasnt possible to make a normal hyperlink using the POST method.

And then i had a eureka moment!!!! why not just use CSS to make the submit button look like a normal hyperlink??? ...and put the value i want to pass in a hidden field

i tried it and it works. you can see an exaple here http://paulyouthed.com/test/css-button-that-looks-like-hyperlink.php

the basic code for the form is:

    <form enctype="multipart/form-data" action="page-to-pass-to.php" method="post">
                        <input type="hidden" name="post-variable-name" value="value-you-want-pass"/>
                        <input type="submit" name="whatever" value="text-to-display" id="hyperlink-style-button"/>
                </form>

the basic css is:

    #hyperlink-style-button{
      background:none;
      border:0;
      color:#666;
      text-decoration:underline;
    }

    #hyperlink-style-button:hover{
      background:none;
      border:0;
      color:#666;
      text-decoration:none;
      cursor:pointer;
      cursor:hand;
    }

How can I deploy an iPhone application from Xcode to a real iPhone device?

Free Provisioning after Xcode 7

In order to test your app on a real device rather than pay the Apple Developer fee (or jailbreak your device), you can use the new free provisioning that Xcode 7 and iOS 9 supports.

Here are the steps taken more or less from the documentation (which is pretty good, so give it a read):

1. Add your Apple ID in Xcode

Go to XCode > Preferences > Accounts tab > Add button (+) > Add Apple ID. See the docs for more help.

2. Click the General tab in the Project Navigator

3. Choose your Apple ID from the Team popup menu.

4. Connect your device and choose it in the scheme menu.

5. Click the Fix Issues button

If you get an error about the bundle name being invalid, change it to something unique.

6. Run your app

In Xcode, click the Build and run button.

7. Trust the app developer in the device settings

After running your app, you will get a security error because the app you want to run is not from the App Store.

On your device, go to Settings > General > Profile > your-Apple-ID-name > Trust your-Apple-ID-name > Trust.

8. Run your app on your device again.

That's it. You can now run your own (or any other apps that you have the source code for) without having to dish out the $99 dollars. Thank you, Apple, for finally allowing this.

How do I uniquely identify computers visiting my web site?

The suggestions to use cookies aside, the only comprehensive set of identifying attributes available to interrogate are contained in the HTTP request header. So it is possible to use some subset of these to create a pseudo-unique identifier for a user agent (i.e., browser). Further, most of this information is possibly already being logged in the so-called "access log" of your web server software by default and, if not, can be easily configured to do so. Then, a utlity could be developed that simply scans the content of this log, creating fingerprints of each request comprised of, say, the IP address and User Agent string, etc. The more data available, even including the contents of specific cookies, adds to the quality of the uniqueness of this fingerprint. Though, as many others have stated already, the HTTP protocol doesn't make this 100% foolproof - at best it can only be a fairly good indicator.

Struct like objects in Java

It appears that many Java people are not familiar with the Sun Java Coding Guidelines which say it is quite appropriate to use public instance variable when the class is essentially a "Struct", if Java supported "struct" (when there is no behavior).

People tend to think getters and setters are the Java way, as if they are at the heart of Java. This is not so. If you follow the Sun Java Coding Guidelines, using public instance variables in appropriate situations, you are actually writing better code than cluttering it with needless getters and setters.

Java Code Conventions from 1999 and still unchanged.

10.1 Providing Access to Instance and Class Variables

Don't make any instance or class variable public without good reason. Often, instance variables don't need to be explicitly set or gotten-often that happens as a side effect of method calls.

One example of appropriate public instance variables is the case where the class is essentially a data structure, with no behavior. In other words, if you would have used a struct instead of a class (if Java supported struct), then it's appropriate to make the class's instance variables public.

http://www.oracle.com/technetwork/java/javase/documentation/codeconventions-137265.html#177

http://en.wikipedia.org/wiki/Plain_old_data_structure

http://docs.oracle.com/javase/1.3/docs/guide/collections/designfaq.html#28

Simple JavaScript Checkbox Validation

You could use:

 if(!this.form.checkbox.checked)
{
    alert('You must agree to the terms first.');
    return false;
}

(demo page).

<input type="checkbox" name="checkbox" value="check"  />
<input type="submit" name="email_submit" value="submit" onclick="if(!this.form.checkbox.checked){alert('You must agree to the terms first.');return false}"  />

Returning false from an inline event handler will prevent the default action from taking place (in this case, submitting the form).
! is the Boolean NOT operator.
this is the submit button because it is the element the event handler is attached to.
.form is the form the submit button is in.
.checkbox is the control named "checkbox" in that form.
.checked is true if the checkbox is checked and false if the checkbox is unchecked.

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

How to use subprocess popen Python

subprocess.Popen takes a list of arguments:

from subprocess import Popen, PIPE

process = Popen(['swfdump', '/tmp/filename.swf', '-d'], stdout=PIPE, stderr=PIPE)
stdout, stderr = process.communicate()

There's even a section of the documentation devoted to helping users migrate from os.popen to subprocess.

Return the most recent record from ElasticSearch index

the _timestamp didn't work out for me,

this query does work for me:

(as in mconlin's answer)

{
  "query": {
    "match_all": {}
  },
  "size": "1",
  "sort": [
    {
      "@timestamp": {
        "order": "desc"
      }
    }
  ]
}

Could be trivial but the _timestamp answer didn't gave an error but not a good result either...

Hope to help someone...

(kibana/elastic 5.0.4)

Programs & Examples On #Accelerated c++

Could not load file or assembly System.Web.Http.WebHost after published to Azure web site

What is Haskell used for in the real world?

How to set Oracle's Java as the default Java in Ubuntu?

Parse error: Syntax error, unexpected end of file in my PHP code

Android Gradle 5.0 Update:Cause: org.jetbrains.plugins.gradle.tooling.util

Change table header color using bootstrap

JavaScript: Upload file

Pure JS

MySQL Delete all rows from table and reset ID to zero

How do I export (and then import) a Subversion repository?

Convert string to int array using LINQ

Syncing Android Studio project with Gradle files

How do you extract a JAR in a UNIX filesystem with a single command and specify its target directory using the JAR command?

Does the 'mutable' keyword have any purpose other than allowing the variable to be modified by a const function?

REST response code for invalid data

2.3.2 418 I'm a teapot

Adding the "Clear" Button to an iPhone UITextField

Circle-Rectangle collision detection (intersection)

Pass a data.frame column name to a function

Python 2: AttributeError: 'list' object has no attribute 'strip'

ORA-06502: PL/SQL: numeric or value error: character string buffer too small

How to equalize the scales of x-axis and y-axis in Python matplotlib?

How to Clear Console in Java?

Real time data graphing on a line chart with html5

Docker: Multiple Dockerfiles in project

UnicodeDecodeError, invalid continuation byte

How do I solve this error, "error while trying to deserialize parameter"

How do you refresh the MySQL configuration file without restarting?

Running multiple async tasks and waiting for them all to complete

Multiple models in a view

Converting Java file:// URL to File(...) path, platform independent, including UNC paths

Recursively list all files in a directory including files in symlink directories

Move branch pointer to different commit without checkout

Cron job every three days

How to connect to my http://localhost web server from Android Emulator

how to find all indexes and their columns for tables, views and synonyms in oracle

SQL Insert Query Using C#

Using an image caption in Markdown Jekyll

How to keep a Python script output window open?

How do I correct the character encoding of a file?

Creating a new user and password with Ansible

Difference between Pragma and Cache-Control headers?

How to sum up elements of a C++ vector?

ng-change get new value and original value

Java optional parameters

Django set field value after a form is initialized

Is there an addHeaderView equivalent for RecyclerView?

iOS how to set app icon and launch images

Want to download a Git repository, what do I need (windows machine)?

Is there a way to include commas in CSV columns without breaking the formatting?

How to give a Linux user sudo access?

PHP Converting Integer to Date, reverse of strtotime

Powershell Get-ChildItem most recent file in directory

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ECMAScript 6 arrow function that returns an object

PDF Parsing Using Python - extracting formatted and plain texts

How can I make the Android emulator show the soft keyboard?

Reading in double values with scanf in c

What is setContentView(R.layout.main)?

How to create a self-signed certificate for a domain name for development?

What to do with "Unexpected indent" in python?

how to read certain columns from Excel using Pandas - Python

Wordpress 403/404 Errors: You don't have permission to access /wp-admin/themes.php on this server

SQL Server: convert ((int)year,(int)month,(int)day) to Datetime

Git cli: get user info from username

Simplest way to append data to a SQL Column

How to install and use "make" in Windows?

SQL UPDATE all values in a field with appended string CONCAT not working

Merging dictionaries in C#

Bootstrap row class contains margin-left and margin-right which creates problems

Is there a way to detect if an image is blurry?

C# DateTime to "YYYYMMDDHHMMSS" format

This Row already belongs to another table error when trying to add rows?

java.util.Date format conversion yyyy-mm-dd to mm-dd-yyyy

When to use RDLC over RDL reports?

Q: What is the difference between RDL and RDLC formats?

How to post ASP.NET MVC Ajax form using JavaScript rather than submit button

Property getters and setters

How can I debug a HTTP POST in Chrome?