Programs & Examples On #Visual c++ 2005

The November 2005 release of Microsoft Visual C++, a C and C++ compiler for Windows, also known as the VC8 compiler.

Set CFLAGS and CXXFLAGS options using CMake

You need to set the flags after the project command in your CMakeLists.txt.

Also, if you're calling include(${QT_USE_FILE}) or add_definitions(${QT_DEFINITIONS}), you should include these set commands after the Qt ones since these would append further flags. If that is the case, you maybe just want to append your flags to the Qt ones, so change to e.g.

set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O0 -ggdb")

How do I bind onchange event of a TextBox using JQuery?

You must change the event name from "change" to "onchange":

$(document).ready(function(){
        $("input#tags").bind("onchange", autoFill);
          });

or use the shortcut binder method change:

$(document).ready(function(){
        $("input#tags").change(autoFill);
          });

Note that the onchange event usually fires when the user leave the input, so for auto-complete you better use the keydown event.

ERROR:'keytool' is not recognized as an internal or external command, operable program or batch file

On windows 8, go to C:\Program Files\Java\jre7\bin and in the address bar, type "cmd" without the quotes. This will launch the terminal. Then type in string as describe here.

Getting the source of a specific image element with jQuery

To select and element where you know only the attribute value you can use the below jQuery script

var src = $('.conversation_img[alt="example"]').attr('src');

Please refer the jQuery Documentation for attribute equals selectors

Please also refer to the example in Demo

Following is the code incase you are not able to access the demo..

HTML

<div>
    <img alt="example" src="\images\show.jpg" />
    <img  alt="exampleAll" src="\images\showAll.jpg" />  

</div>

SCRIPT JQUERY

var src = $('img[alt="example"]').attr('src');
alert("source of image with alternate text = example - " + src);


var srcAll = $('img[alt="exampleAll"]').attr('src');
alert("source of image with alternate text = exampleAll - " + srcAll );

Output will be

Two Alert messages each having values

  1. source of image with alternate text = example - \images\show.jpg
  2. source of image with alternate text = exampleAll - \images\showAll.jpg

Does IMDB provide an API?

that deanclatworthy still seems to work and there's another one: http://imdbapi.poromenos.org/

MySQL timestamp select date range

SELECT * FROM table WHERE col >= '2010-10-01' AND col <= '2010-10-31'

How can I add a new column and data to a datatable that already contains data?

Only you want to set default value parameter. This calling third overloading method.

dt.Columns.Add("MyRow", type(System.Int32),0);

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

The difference is the value returned to the environment is 0 in the former case and 1 in the latter case:

$ ./prog_with_exit_0
$ echo $?
0
$

and

$ ./prog_with_exit_1
$ echo $?
1
$

Also note that the macros value EXIT_SUCCESS and EXIT_FAILURE used as an argument to exit function are implementation defined but are usually set to respectively 0 and a non-zero number. (POSIX requires EXIT_SUCCESS to be 0). So usually exit(0) means a success and exit(1) a failure.

An exit function call with an argument in main function is equivalent to the statement return with the same argument.

JQuery show/hide when hover

jquery:

$('div.animalcontent').hide();
$('div').hide();
$('p.animal').bind('mouseover', function() {
    $('div.animalcontent').fadeOut();
    $('#'+$(this).attr('id')+'content').fadeIn();
});  

html:

<p class='animal' id='dog'>dog url</p><div id='dogcontent' class='animalcontent'>Doggiecontent!</div>
<p class='animal' id='cat'>cat url</p><div id='catcontent' class='animalcontent'>Pussiecontent!</div>
<p class='animal' id='snake'>snake url</p><div id='snakecontent'class='animalcontent'>Snakecontent!</div>

-edit-

yeah sure, here you go -- JSFiddle

Pressed <button> selector

Maybe :active over :focus with :hover will help! Try

button {
background:lime;
}

button:hover {
background:green;
}

button:focus {
background:gray;
}

button:active {
background:red;
}

Then:

<button onkeydown="alerted_of_key_pressed()" id="button" title="Test button" href="#button">Demo</button>

Then:

<!--JAVASCRIPT-->
<script>
function alerted_of_key_pressed() { alert("You pressed a key when hovering over this button.") }
</script>
 Sorry about that last one. :) I was just showing you a cool function! 
Wait... did I just emphasize a code block? This is cool!!!

iOS 7 - Failing to instantiate default view controller

1st option

if you want to set your custom storyboard instead of a default view controller.

Change this attribute from info.plist file

<key>UISceneStoryboardFile</key> <string>Onboarding</string>

Onboarding would be your storyboard name

to open this right-click on info.plist file and open as a source code

2nd option

1- Click on your project

2- Select your project from the target section

3- Move to Deployment interface section

4- Change your storyboard section from Main Interface field

Please remember set your storyboard initial view controller

How to update (append to) an href in jquery?

$("a.directions-link").attr("href", $("a.directions-link").attr("href")+"...your additions...");

How to fix 'android.os.NetworkOnMainThreadException'?

Android Jetpack introduced WorkManager,which fixes the problem of background service restriction in Oreo and use of Alarm Manager below Lolipop and JobScheduler above Lolipop.

Please use WorkManager to run tasks on background thread and it's continue to run even after user closes the app.

Batch file FOR /f tokens

for /f "tokens=* delims= " %%f in (myfile) do

This reads a file line-by-line, removing leading spaces (thanks, jeb).

set line=%%f

sets then the line variable to the line just read and

call :procesToken

calls a subroutine that does something with the line

:processToken

is the start of the subroutine mentioned above.

for /f "tokens=1* delims=/" %%a in ("%line%") do

will then split the line at /, but stopping tokenization after the first token.

echo Got one token: %%a

will output that first token and

set line=%%b

will set the line variable to the rest of the line.

if not "%line%" == "" goto :processToken

And if line isn't yet empty (i.e. all tokens processed), it returns to the start, continuing with the rest of the line.

trying to align html button at the center of the my page

I've really taken recently to display: table to give things a fixed size such as to enable margin: 0 auto to work. Has made my life a lot easier. You just need to get past the fact that 'table' display doesn't mean table html.

It's especially useful for responsive design where things just get hairy and crazy 50% left this and -50% that just become unmanageable.

style
{
   display: table;
   margin: 0 auto
}

JsFiddle

In addition if you've got two buttons and you want them the same width you don't even need to know the size of each to get them to be the same width - because the table will magically collapse them for you.

enter image description here

JsFiddle

(this also works if they're inline and you want to center two buttons side to side - try doing that with percentages!).

Android Relative Layout Align Center

Use this in your RelativeLayout

android:gravity="center_vertical"

Cannot attach the file *.mdf as database

I didn't read all the responses, but if your .mdf file is NOT part of the SQL installation path, like C:\Temp, then the SQL Database Engine service account(s) will not have permission to create and write to the .ldf file or even read the .mdf file.

The solution is you have to give file system permissions to the SQL Server database engine service account that runs the SQL instance service. So for me, I gave permissions full control via Windows Explorer to my C:\Temp path that contained my .mdf file for the NT Service\MSSQL$SQLEXPRESS01 and NT Service\MSSQL$MSSQL2016 accounts.

Here is a Microsoft article that details this very issue.

Dynamically allocating an array of objects

Why not have a setSize method.

A* arrayOfAs = new A[5];
for (int i = 0; i < 5; ++i)
{
    arrayOfAs[i].SetSize(3);
}

I like the "copy" but in this case the default constructor isn't really doing anything. The SetSize could copy the data out of the original m_array (if it exists).. You'd have to store the size of the array within the class to do that.
OR
The SetSize could delete the original m_array.

void SetSize(unsigned int p_newSize)
{
    //I don't care if it's null because delete is smart enough to deal with that.
    delete myArray;
    myArray = new int[p_newSize];
    ASSERT(myArray);
}

Set Windows process (or user) memory limit

No way to do this that I know of, although I'm very curious to read if anyone has a good answer. I have been thinking about adding something like this to one of the apps my company builds, but have found no good way to do it.

The one thing I can think of (although not directly on point) is that I believe you can limit the total memory usage for a COM+ application in Windows. It would require the app to be written to run in COM+, of course, but it's the closest way I know of.

The working set stuff is good (Job Objects also control working sets), but that's not total memory usage, only real memory usage (paged in) at any one time. It may work for what you want, but afaik it doesn't limit total allocated memory.

Meaning of Open hashing and Closed hashing

The use of "closed" vs. "open" reflects whether or not we are locked in to using a certain position or data structure (this is an extremely vague description, but hopefully the rest helps).

For instance, the "open" in "open addressing" tells us the index (aka. address) at which an object will be stored in the hash table is not completely determined by its hash code. Instead, the index may vary depending on what's already in the hash table.

The "closed" in "closed hashing" refers to the fact that we never leave the hash table; every object is stored directly at an index in the hash table's internal array. Note that this is only possible by using some sort of open addressing strategy. This explains why "closed hashing" and "open addressing" are synonyms.

Contrast this with open hashing - in this strategy, none of the objects are actually stored in the hash table's array; instead once an object is hashed, it is stored in a list which is separate from the hash table's internal array. "open" refers to the freedom we get by leaving the hash table, and using a separate list. By the way, "separate list" hints at why open hashing is also known as "separate chaining".

In short, "closed" always refers to some sort of strict guarantee, like when we guarantee that objects are always stored directly within the hash table (closed hashing). Then, the opposite of "closed" is "open", so if you don't have such guarantees, the strategy is considered "open".

How can I open Windows Explorer to a certain directory from within a WPF app?

This should work:

Process.Start(@"<directory goes here>")

Or if you'd like a method to run programs/open files and/or folders:

private void StartProcess(string path)
{
    ProcessStartInfo StartInformation = new ProcessStartInfo();

    StartInformation.FileName = path;

    Process process = Process.Start(StartInformation);

    process.EnableRaisingEvents = true;
}

And then call the method and in the parenthesis put either the directory of the file and/or folder there or the name of the application. Hope this helped!

How do I convert certain columns of a data frame to become factors?

Here's an example:

#Create a data frame
> d<- data.frame(a=1:3, b=2:4)
> d
  a b
1 1 2
2 2 3
3 3 4

#currently, there are no levels in the `a` column, since it's numeric as you point out.
> levels(d$a)
NULL

#Convert that column to a factor
> d$a <- factor(d$a)
> d
  a b
1 1 2
2 2 3
3 3 4

#Now it has levels.
> levels(d$a)
[1] "1" "2" "3"

You can also handle this when reading in your data. See the colClasses and stringsAsFactors parameters in e.g. readCSV().

Note that, computationally, factoring such columns won't help you much, and may actually slow down your program (albeit negligibly). Using a factor will require that all values are mapped to IDs behind the scenes, so any print of your data.frame requires a lookup on those levels -- an extra step which takes time.

Factors are great when storing strings which you don't want to store repeatedly, but would rather reference by their ID. Consider storing a more friendly name in such columns to fully benefit from factors.

Is the 'as' keyword required in Oracle to define an alias?

There is no difference between both, AS is just a more explicit way of mentioning the alias which is good because some dependent libraries depends on this small keyword. e.g. JDBC 4.0. Depend on use of it, different behaviour can be observed.

See this. I would always suggest to use the full form of semantic to avoid such issues.

What's the difference between event.stopPropagation and event.preventDefault?

Terminology

From quirksmode.org:

Event capturing

When you use event capturing

               | |
---------------| |-----------------
| element1     | |                |
|   -----------| |-----------     |
|   |element2  \ /          |     |
|   -------------------------     |
|        Event CAPTURING          |
-----------------------------------

the event handler of element1 fires first, the event handler of element2 fires last.

Event bubbling

When you use event bubbling

               / \
---------------| |-----------------
| element1     | |                |
|   -----------| |-----------     |
|   |element2  | |          |     |
|   -------------------------     |
|        Event BUBBLING           |
-----------------------------------

the event handler of element2 fires first, the event handler of element1 fires last.

Any event taking place in the W3C event model is first captured until it reaches the target element and then bubbles up again.

                 | |  / \
-----------------| |--| |-----------------
| element1       | |  | |                |
|   -------------| |--| |-----------     |
|   |element2    \ /  | |          |     |
|   --------------------------------     |
|        W3C event model                 |
------------------------------------------

Interface

From w3.org, for event capture:

If the capturing EventListener wishes to prevent further processing of the event from occurring it may call the stopPropagation method of the Event interface. This will prevent further dispatch of the event, although additional EventListeners registered at the same hierarchy level will still receive the event. Once an event's stopPropagation method has been called, further calls to that method have no additional effect. If no additional capturers exist and stopPropagation has not been called, the event triggers the appropriate EventListeners on the target itself.

For event bubbling:

Any event handler may choose to prevent further event propagation by calling the stopPropagation method of the Event interface. If any EventListener calls this method, all additional EventListeners on the current EventTarget will be triggered but bubbling will cease at that level. Only one call to stopPropagation is required to prevent further bubbling.

For event cancelation:

Cancelation is accomplished by calling the Event's preventDefault method. If one or more EventListeners call preventDefault during any phase of event flow the default action will be canceled.

Examples

In the following examples, a click on the hyperlink in the web browser triggers the event's flow (the event listeners are executed) and the event target's default action (a new tab is opened).

HTML:

<div id="a">
  <a id="b" href="http://www.google.com/" target="_blank">Google</a>
</div>
<p id="c"></p>

JavaScript:

var el = document.getElementById("c");

function capturingOnClick1(ev) {
    el.innerHTML += "DIV event capture<br>";
}

function capturingOnClick2(ev) {
    el.innerHTML += "A event capture<br>";
}

function bubblingOnClick1(ev) {
    el.innerHTML += "DIV event bubbling<br>";
}

function bubblingOnClick2(ev) {
    el.innerHTML += "A event bubbling<br>";
}

// The 3rd parameter useCapture makes the event listener capturing (false by default)
document.getElementById("a").addEventListener("click", capturingOnClick1, true);
document.getElementById("b").addEventListener("click", capturingOnClick2, true);
document.getElementById("a").addEventListener("click", bubblingOnClick1, false);
document.getElementById("b").addEventListener("click", bubblingOnClick2, false);

Example 1: it results in the output

DIV event capture
A event capture
A event bubbling
DIV event bubbling

Example 2: adding stopPropagation() to the function

function capturingOnClick1(ev) {
    el.innerHTML += "DIV event capture<br>";
    ev.stopPropagation();
}

results in the output

DIV event capture

The event listener prevented further downward and upward propagation of the event. However it did not prevent the default action (a new tab opening).

Example 3: adding stopPropagation() to the function

function capturingOnClick2(ev) {
    el.innerHTML += "A event capture<br>";
    ev.stopPropagation();
}

or the function

function bubblingOnClick2(ev) {
    el.innerHTML += "A event bubbling<br>";
    ev.stopPropagation();
}

results in the output

DIV event capture
A event capture
A event bubbling

This is because both event listeners are registered on the same event target. The event listeners prevented further upward propagation of the event. However they did not prevent the default action (a new tab opening).

Example 4: adding preventDefault() to any function, for instance

function capturingOnClick1(ev) {
    el.innerHTML += "DIV event capture<br>";
    ev.preventDefault();
}

prevents a new tab from opening.

How to revert multiple git commits?

The easy way to revert a group of commits on shared repository (that people use and you want to preserve the history) is to use git revert in conjunction with git rev-list. The latter one will provide you with a list of commits, the former will do the revert itself.

There are two ways to do that. If you want the revert multiple commits in a single commit use:

for i in `git rev-list <first-commit-sha>^..<last-commit-sha>`; do git revert --no-commit $i; done

this will revert a group of commits you need, but leave all the changes on your working tree, you should commit them all as usual afterward.

Another option is to have a single commit per reverted change:

for i in `git rev-list <first-commit-sha>^..<last-commit-sha>`; do git revert --no-edit -s $i; done

For instance, if you have a commit tree like

 o---o---o---o---o---o--->    
fff eee ddd ccc bbb aaa

to revert the changes from eee to bbb, run

for i in `git rev-list eee^..bbb`; do git revert --no-edit -s $i; done

How do I "decompile" Java class files?

With AndroChef Java Decompiler you can decompile apk, dex, jar and java class-files. It's simple and easy. AndroChef JD is based on FernFlower. You can evaluate it in 10 free uses.

AndroChef supports Java language features like generics, enums and annotations. According to some studies, AndroChef Java Decompiler is able to decompile 98.04% of Java applications generated with traditional Java compilers - a very high recovery rate. It is simple but powerful tool that allows you to decompile Java and Dalvik bytecode (DEX, APK) into readable Java source.

Git pull till a particular commit

First, fetch the latest commits from the remote repo. This will not affect your local branch.

git fetch origin

Then checkout the remote tracking branch and do a git log to see the commits

git checkout origin/master
git log

Grab the commit hash of the commit you want to merge up to (or just the first ~5 chars of it) and merge that commit into master

git checkout master
git merge <commit hash>

How to check version of python modules?

Assuming we are using Jupyter Notebook (if using Terminal, drop the exclamation marks):

1) if the package (e.g. xgboost) was installed with pip:

!pip show xgboost
!pip freeze | grep xgboost
!pip list | grep xgboost

2) if the package (e.g. caffe) was installed with conda:

!conda list caffe

Use .htaccess to redirect HTTP to HTTPs

Just add or replace this code in your .htaccess file in wordpress

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /

RewriteCond %{HTTPS} !=on
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

Convert a String of Hex into ASCII in Java

Check out Convert a string representation of a hex dump to a byte array using Java?

Disregarding encoding, etc. you can do new String (hexStringToByteArray("75546..."));

CSS content property: is it possible to insert HTML instead of Text?

As almost noted in comments to @BoltClock's answer, in modern browsers, you can actually add some html markup to pseudo-elements using the (url()) in combination with svg's <foreignObject> element.

You can either specify an URL pointing to an actual svg file, or create it with a dataURI version (data:image/svg+xml; charset=utf8, + encodeURIComponent(yourSvgMarkup))

But note that it is mostly a hack and that there are a lot of limitations :

  • You can not load any external resources from this markup (no CSS, no images, no media etc.).
  • You can not execute script.
  • Since this won't be part of the DOM, the only way to alter it, is to pass the markup as a dataURI, and edit this dataURI in document.styleSheets. for this part, DOMParser and XMLSerializer may help.
  • While the same operation allows us to load url-encoded media in <img> tags, this won't work in pseudo-elements (at least as of today, I don't know if it is specified anywhere that it shouldn't, so it may be a not-yet implemented feature).

Now, a small demo of some html markup in a pseudo element :

_x000D_
_x000D_
/* _x000D_
**  original svg code :_x000D_
*_x000D_
*<svg width="200" height="60"_x000D_
*     xmlns="http://www.w3.org/2000/svg">_x000D_
*_x000D_
* <foreignObject width="100%" height="100%" x="0" y="0">_x000D_
* <div xmlns="http://www.w3.org/1999/xhtml" style="color: blue">_x000D_
*  I am <pre>HTML</pre>_x000D_
* </div>_x000D_
* </foreignObject>_x000D_
*</svg>_x000D_
*_x000D_
*/
_x000D_
#log::after {_x000D_
  content: url('data:image/svg+xml;%20charset=utf8,%20%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20height%3D%2260%22%20width%3D%22200%22%3E%0A%0A%20%20%3CforeignObject%20y%3D%220%22%20x%3D%220%22%20height%3D%22100%25%22%20width%3D%22100%25%22%3E%0A%09%3Cdiv%20style%3D%22color%3A%20blue%22%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1999%2Fxhtml%22%3E%0A%09%09I%20am%20%3Cpre%3EHTML%3C%2Fpre%3E%0A%09%3C%2Fdiv%3E%0A%20%20%3C%2FforeignObject%3E%0A%3C%2Fsvg%3E');_x000D_
}
_x000D_
<p id="log">hi</p>
_x000D_
_x000D_
_x000D_

Removing all empty elements from a hash / YAML?

This one would delete empty hashes too:

swoop = Proc.new { |k, v| v.delete_if(&swoop) if v.kind_of?(Hash);  v.empty? }
hsh.delete_if &swoop

iOS application: how to clear notifications?

Maybe in case there are scheduled alarms and uncleared app icon badges.

NSArray *scheduledLocalNotifications = [application scheduledLocalNotifications];
NSInteger applicationIconBadgeNumber = [application applicationIconBadgeNumber];

[application cancelAllLocalNotifications];
[application setApplicationIconBadgeNumber:0];

for (UILocalNotification* scheduledLocalNotification in scheduledLocalNotifications) {
    [application scheduleLocalNotification:scheduledLocalNotification];
}
[application setApplicationIconBadgeNumber:applicationIconBadgeNumber];

How to install Ruby 2.1.4 on Ubuntu 14.04

Use RVM (Ruby Version Manager) to install and manage any versions of Ruby. You can have multiple versions of Ruby installed on the machine and you can easily select the one you want.

To install RVM type into terminal:

\curl -sSL https://get.rvm.io | bash -s stable

And let it work. After that you will have RVM along with Ruby installed.

Source: RVM Site

Using form input to access camera and immediately upload photos using web app

It's really easy to do this, simply send the file via an XHR request inside of the file input's onchange handler.

<input id="myFileInput" type="file" accept="image/*;capture=camera">

var myInput = document.getElementById('myFileInput');

function sendPic() {
    var file = myInput.files[0];

    // Send file here either by adding it to a `FormData` object 
    // and sending that via XHR, or by simply passing the file into 
    // the `send` method of an XHR instance.
}

myInput.addEventListener('change', sendPic, false);

How to add text inside the doughnut chart using Chart.js?

First of all, kudos on choosing Chart.js! I'm using it on one of my current projects and I absolutely love it - it does the job perfectly.

Although labels/tooltips are not part of the library yet, you may want to take a look at these three pull requests:

And, as Cracker0dks mentioned, Chart.js uses canvas for rendering so you may as well just implement your own tooltips by interacting with it directly.

Hope this helps.

Describe table structure

This depends on your database vendor. Mostly it's the "information schema" you should Google for (applies to MySQL, MSSQL and perhaps others).

The opposite of Intersect()

As stated, if you want to get 4 as the result, you can do like this:

var nonintersect = array2.Except(array1);

If you want the real non-intersection (also both 1 and 4), then this should do the trick:

var nonintersect = array1.Except(array2).Union( array2.Except(array1));

This will not be the most performant solution, but for small lists it should work just fine.

Github permission denied: ssh add agent has no identities

I have been stucked a while on the same problem, which I eventually resolved.

My problem: I could not execute any push. I could check & see my remote (using git remote -v), but when I executed git push origin master, it returned : Permission denied (publickey). fatal: Could not read from remote repository. and so.

How I solved it :

  • I generated a key using ssh-keygen -t rsa. Entering a name for the key file (when asked) was useless.
  • I could then add the key (to git): ssh-add /Users/federico/.ssh/id_rsa , which successfully returned Identity added: /Users/myname/.ssh/id_rsa (/Users/myname/.ssh/id_rsa)
  • I added the SSH key to github using this help page.
  • Having tried all the commands in Github's 'Permission denied publickey' help page, only the ssh-add -l command worked / seemed useful (after having ran the previous steps), it successfully returned my key. The last step shows you where to check your public key on your GitHub page. And this command will help you check all your keys : ls -al ~/.ssh.

Then the push command eventually worked !

I hope this will help ! Best luck to all.

Showing the same file in both columns of a Sublime Text window

I regularly work on the same file in 2 different positions. I solved this in Sublime Text 3 using origami and chain with some additional config.

My workflow is Ctrl + k + 2 splits the view of the file in two (horizontal) panes with the lower one active. Use Ctrl + k + o to toggle between the panes. When done ensure the lower pane is the active and press Ctrl + F4 to close the duplicated view and the pane.

In sublime global settings (not origami settings!) add

"origami_auto_close_empty_panes": true,

Add the following shortcuts

  { "keys": ["ctrl+k", "2"], 
    "command": "chain", 
    "args": {
      "commands": [
        ["create_pane", {"direction": "down"}],
        ["clone_file_to_pane", {"direction": "down"}],
      ],
    }
  },

  { "keys": ["ctrl+k", "o"], "command": "focus_neighboring_group" },

How to change default format at created_at and updated_at value laravel

In laravel 6 the latest one can easily add in the "APP/user.php" model:

/**
 * The storage format of the model's date columns.
 *
 * @var string
 */
protected $dateFormat = 'U';

And in schema one can add

    $table->integer('created_at')->nullable();
    $table->integer('updated_at')->nullable();

How to get the last characters in a String in Java, regardless of String size

org.apache.commons.lang3.StringUtils.substring(s, -7) 

gives you the answer. It returns the input if it is shorter than 7, and null if s == null. It never throws an exception.

See https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/StringUtils.html#substring-java.lang.String-int-int-

Insert new column into table in sqlite?

I was facing the same problem and the second method proposed in the accepted answer, as noted in the comments, can be problematic when dealing with foreign keys.

My workaround is to export the database to a sql file making sure that the INSERT statements include column names. I do it using DB Browser for SQLite which has an handy feature for that. After that you just have to edit the create table statement and insert the new column where you want it and recreate the db.

In *nix like systems is just something along the lines of

cat db.sql | sqlite3 database.db

I don't know how feasible this is with very big databases, but it worked in my case.

Min/Max of dates in an array?

This is a particularly great way to do this (you can get max of an array of objects using one of the object properties): Math.max.apply(Math,array.map(function(o){return o.y;}))

This is the accepted answer for this page: Finding the max value of an attribute in an array of objects

Is it possible to interactively delete matching search pattern in Vim?

http://vim.wikia.com/wiki/Search_and_replace

Try this search and replace:

:%s/foo/bar/gc

Change each 'foo' to 'bar', but ask for confirmation first.

Press y or n to change or keep your text.

Simple example of threading in C++

Unless one want a separate function in global namespacs, we can use lambda functions for creating threads.

One of the major advantage of creating thread using lambda is that we don't need to pass local parameters as an argument list. We can use capture list for the same and the closure property of lambda will take care of the lifecycle.

Here is a sample code

int main() {
    int localVariable = 100;

    thread th { [=](){
        cout<<"The Value of local variable => "<<localVariable<<endl;
    }};

    th.join();

    return 0;
}

By far, I've found C++ lambdas to be the best way of creating threads especially for simpler thread functions

How to try convert a string to a Guid

This will get you pretty close, and I use it in production and have never had a collision. However, if you look at the constructor for a guid in reflector, you will see all of the checks it makes.

 public static bool GuidTryParse(string s, out Guid result)
    {
        if (!String.IsNullOrEmpty(s) && guidRegEx.IsMatch(s))
        {
            result = new Guid(s);
            return true;
        }

        result = default(Guid);
        return false;
    }

    static Regex guidRegEx = new Regex("^[A-Fa-f0-9]{32}$|" +
                          "^({|\\()?[A-Fa-f0-9]{8}-([A-Fa-f0-9]{4}-){3}[A-Fa-f0-9]{12}(}|\\))?$|" +
                          "^({)?[0xA-Fa-f0-9]{3,10}(, {0,1}[0xA-Fa-f0-9]{3,6}){2}, {0,1}({)([0xA-Fa-f0-9]{3,4}, {0,1}){7}[0xA-Fa-f0-9]{3,4}(}})$", RegexOptions.Compiled);

How do I pipe a subprocess call to a text file?

If you want to write the output to a file you can use the stdout-argument of subprocess.call.

It takes None, subprocess.PIPE, a file object or a file descriptor. The first is the default, stdout is inherited from the parent (your script). The second allows you to pipe from one command/process to another. The third and fourth are what you want, to have the output written to a file.

You need to open a file with something like open and pass the object or file descriptor integer to call:

f = open("blah.txt", "w")
subprocess.call(["/home/myuser/run.sh", "/tmp/ad_xml",  "/tmp/video_xml"], stdout=f)

I'm guessing any valid file-like object would work, like a socket (gasp :)), but I've never tried.

As marcog mentions in the comments you might want to redirect stderr as well, you can redirect this to the same location as stdout with stderr=subprocess.STDOUT. Any of the above mentioned values works as well, you can redirect to different places.

Raw SQL Query without DbSet - Entity Framework Core

In Core 2.1 you can do something like this:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
       modelBuilder.Query<Ranks>();
}

and then define you SQL Procedure, like:

public async Task<List<Ranks>> GetRanks(string value1, Nullable<decimal> value2)
{
    SqlParameter value1Input = new SqlParameter("@Param1", value1?? (object)DBNull.Value);
    SqlParameter value2Input = new SqlParameter("@Param2", value2?? (object)DBNull.Value);

    List<Ranks> getRanks = await this.Query<Ranks>().FromSql("STORED_PROCEDURE @Param1, @Param2", value1Input, value2Input).ToListAsync();

    return getRanks;
}

This way Ranks model will not be created in your DB.

Now in your controller/action you can call:

List<Ranks> gettingRanks = _DbContext.GetRanks(value1,value2).Result.ToListAsync();

This way you can call Raw SQL Procedures.

How to highlight a current menu item?

Here is yet another directive to highlight active links.

Key features:

  • Works fine with href that contains dynamic angular expressions
  • Compatible with hash-bang navigation
  • Compatible with Bootstrap where active class should be applied to parent li not the link itself
  • Allows make link active if any nested path is active
  • Allows make link disabled if it is not active

Code:

.directive('activeLink', ['$location', 
function($location) {
    return {
        restrict: 'A',
        link: function(scope, elem, attrs) {
            var path = attrs.activeLink ? 'activeLink' : 'href';
            var target = angular.isDefined(attrs.activeLinkParent) ? elem.parent() : elem;
            var disabled = angular.isDefined(attrs.activeLinkDisabled) ? true : false;
            var nested = angular.isDefined(attrs.activeLinkNested) ? true : false;

            function inPath(needle, haystack) {
                var current = (haystack == needle);
                if (nested) {
                    current |= (haystack.indexOf(needle + '/') == 0);
                }

                return current;
            }

            function toggleClass(linkPath, locationPath) {
                // remove hash prefix and trailing slashes
                linkPath = linkPath ? linkPath.replace(/^#!/, '').replace(/\/+$/, '') : '';
                locationPath = locationPath.replace(/\/+$/, '');

                if (linkPath && inPath(linkPath, locationPath)) {
                    target.addClass('active');
                    if (disabled) {
                        target.removeClass('disabled');
                    }
                } else {
                    target.removeClass('active');
                    if (disabled) {
                        target.addClass('disabled');
                    }
                }
            }

            // watch if attribute value changes / evaluated
            attrs.$observe(path, function(linkPath) {
                toggleClass(linkPath, $location.path());
            });

            // watch if location changes
            scope.$watch(
                function() {
                    return $location.path(); 
                }, 
                function(newPath) {
                    toggleClass(attrs[path], newPath);
                }
            );
        }
    };
}
]);

Usage:

Simple example with angular expression, lets say $scope.var = 2, then link will be active if location is /url/2 :

<a href="#!/url/{{var}}" active-link>

Bootstrap example, parent li will get active class:

<li>
    <a href="#!/url" active-link active-link-parent>
</li>

Example with nested urls, link will be active if any nested url is active (i.e. /url/1, /url/2, url/1/2/...)

<a href="#!/url" active-link active-link-nested>

Complex example, link points to one url (/url1) but will be active if another is selected (/url2):

<a href="#!/url1" active-link="#!/url2" active-link-nested>

Example with disabled link, if it is not active it will have 'disabled' class:

<a href="#!/url" active-link active-link-disabled>

All active-link-* attributes can be used in any combination, so very complex conditions could be implemented.

Type converting slices of interfaces

In case you need more shorting your code, you can creating new type for helper

type Strings []string

func (ss Strings) ToInterfaceSlice() []interface{} {
    iface := make([]interface{}, len(ss))
    for i := range ss {
        iface[i] = ss[i]
    }
    return iface
}

then

a := []strings{"a", "b", "c", "d"}
sliceIFace := Strings(a).ToInterfaceSlice()

How to load a jar file at runtime

I googled a bit, and found this code here:

File file = getJarFileToLoadFrom();   
String lcStr = getNameOfClassToLoad();   
URL jarfile = new URL("jar", "","file:" + file.getAbsolutePath()+"!/");    
URLClassLoader cl = URLClassLoader.newInstance(new URL[] {jarfile });   
Class loadedClass = cl.loadClass(lcStr);   

Can anyone share opinions/comments/answers regarding this approach?

How to format a QString?

You can use QString.arg like this

QString my_formatted_string = QString("%1/%2-%3.txt").arg("~", "Tom", "Jane");
// You get "~/Tom-Jane.txt"

This method is preferred over sprintf because:

Changing the position of the string without having to change the ordering of substitution, e.g.

// To get "~/Jane-Tom.txt"
QString my_formatted_string = QString("%1/%3-%2.txt").arg("~", "Tom", "Jane");

Or, changing the type of the arguments doesn't require changing the format string, e.g.

// To get "~/Tom-1.txt"
QString my_formatted_string = QString("%1/%2-%3.txt").arg("~", "Tom", QString::number(1));

As you can see, the change is minimal. Of course, you generally do not need to care about the type that is passed into QString::arg() since most types are correctly overloaded.

One drawback though: QString::arg() doesn't handle std::string. You will need to call: QString::fromStdString() on your std::string to make it into a QString before passing it to QString::arg(). Try to separate the classes that use QString from the classes that use std::string. Or if you can, switch to QString altogether.

UPDATE: Examples are updated thanks to Frank Osterfeld.

UPDATE: Examples are updated thanks to alexisdm.

How to get first element in a list of tuples?

Those are tuples, not sets. You can do this:

l1 = [(1, u'abc'), (2, u'def')]
l2 = [(tup[0],) for tup in l1]
l2
>>> [(1,), (2,)]

console.log not working in Angular2 Component (Typescript)

The console.log should be wrapped in a function , the "default" function for every class is its constructor so it should be declared there.

import { Component } from '@angular/core';
console.log("Hello1");

 @Component({
  selector: 'hello-console',
})
    export class App {
     s: string = "Hello2";
    constructor(){
     console.log(s); 
    }

}

Trim leading and trailing spaces from a string in awk

If it is safe to assume only one set of spaces in column two (which is the original example):

awk '{print $1$2}' /tmp/input.txt

Adding another field, e.g. awk '{print $1$2$3}' /tmp/input.txt will catch two sets of spaces (up to three words in column two), and won't break if there are fewer.

If you have an indeterminate (large) number of space delimited words, I'd use one of the previous suggestions, otherwise this solution is the easiest you'll find using awk.

.NET HashTable Vs Dictionary - Can the Dictionary be as fast?

Dictionaries have the advantage of being a generic type, which makes it type safe and a bit faster due to lack of need for boxing. The following comparison table (constructed using the answers found in a similar SO question post) illustrates some of the other reasons that support dictionaries over hash tables (or vice versa).

Generic deep diff between two objects

Here is a JavaScript library which you can use for finding diff between two JavaScript objects:

Github URL: https://github.com/cosmicanant/recursive-diff

Npmjs url: https://www.npmjs.com/package/recursive-diff

You can use recursive-diff library in browser as well as Node.js. For browser, do the following:

<script type="text" src="https://unpkg.com/recursive-diff@latest/dist/recursive-diff.min.js"/>
<script type="text/javascript">
     const ob1 = {a:1, b: [2,3]};
     const ob2 = {a:2, b: [3,3,1]};
     const delta = recursiveDiff.getDiff(ob1,ob2); 
     /* console.log(delta) will dump following data 
     [
         {path: ['a'], op: 'update', val: 2}
         {path: ['b', '0'], op: 'update',val: 3},
         {path: ['b',2], op: 'add', val: 1 },
     ]
      */
     const ob3 = recursiveDiff.applyDiff(ob1, delta); //expect ob3 is deep equal to ob2
 </script>

Whereas in node.js you can require 'recursive-diff' module and use it like below:

const diff = require('recursive-diff');
const ob1 = {a: 1}, ob2: {b:2};
const diff = diff.getDiff(ob1, ob2);

Post request in Laravel - Error - 419 Sorry, your session/ 419 your page has expired

If you already have the csrf directive, you might have changed the way sessions runs.

In config/session.php, check the 'secure' field. It should be on false if https isn't available on your server.

You can also put SESSION_SECURE_COOKIE=FALSE on your .env file (root directory).

How to Generate a random number of fixed length using JavaScript?

I would go with this solution:

Math.floor(Math.random() * 899999 + 100000)

Plotting a python dict in order of key values

Python dictionaries are unordered. If you want an ordered dictionary, use collections.OrderedDict

In your case, sort the dict by key before plotting,

import matplotlib.pylab as plt

lists = sorted(d.items()) # sorted by key, return a list of tuples

x, y = zip(*lists) # unpack a list of pairs into two tuples

plt.plot(x, y)
plt.show()

Here is the result. enter image description here

Load properties file in JAR?

The problem is that you are using getSystemResourceAsStream. Use simply getResourceAsStream. System resources load from the system classloader, which is almost certainly not the class loader that your jar is loaded into when run as a webapp.

It works in Eclipse because when launching an application, the system classloader is configured with your jar as part of its classpath. (E.g. java -jar my.jar will load my.jar in the system class loader.) This is not the case with web applications - application servers use complex class loading to isolate webapplications from each other and from the internals of the application server. For example, see the tomcat classloader how-to, and the diagram of the classloader hierarchy used.

EDIT: Normally, you would call getClass().getResourceAsStream() to retrieve a resource in the classpath, but as you are fetching the resource in a static initializer, you will need to explicitly name a class that is in the classloader you want to load from. The simplest approach is to use the class containing the static initializer, e.g.

[public] class MyClass {
  static
  {
    ...
    props.load(MyClass.class.getResourceAsStream("/someProps.properties"));
  }
}

What's the difference between %s and %d in Python string formatting?

They are format specifiers. They are used when you want to include the value of your Python expressions into strings, with a specific format enforced.

See Dive into Python for a relatively detailed introduction.

Managing SSH keys within Jenkins for Git

It looks like the github.com host which jenkins tries to connect to is not listed under the Jenkins user's $HOME/.ssh/known_hosts. Jenkins runs on most distros as the user jenkins and hence has its own .ssh directory to store the list of public keys and known_hosts.

The easiest solution I can think of to fix this problem is:

# Login as the jenkins user and specify shell explicity,
# since the default shell is /bin/false for most
# jenkins installations.
sudo su jenkins -s /bin/bash

cd SOME_TMP_DIR
# git clone YOUR_GITHUB_URL

# Allow adding the SSH host key to your known_hosts

# Exit from su
exit

to_string not declared in scope

You need to make some changes in the compiler. In Dev C++ Compiler: 1. Go to compiler settings/compiler Options. 2. Click on General Tab 3. Check the checkbox (Add the following commands when calling the compiler. 4. write -std=c++11 5. click Ok

How to check not in array element

Try with array_intersect method

$id = $access_data['Privilege']['id']; 

if(count(array_intersect($id,$user_access_arr)) == 0){

$this->Session->setFlash(__('Access Denied! You are not eligible to access this.'), 'flash_custom_success');
return $this->redirect(array('controller'=>'Dashboard','action'=>'index'));
}

Java array reflection: isArray vs. instanceof

In the latter case, if obj is null you won't get a NullPointerException but a false.

Color different parts of a RichTextBox string

Here is an extension method that overloads the AppendText method with a color parameter:

public static class RichTextBoxExtensions
{
    public static void AppendText(this RichTextBox box, string text, Color color)
    {
        box.SelectionStart = box.TextLength;
        box.SelectionLength = 0;

        box.SelectionColor = color;
        box.AppendText(text);
        box.SelectionColor = box.ForeColor;
    }
}

And this is how you would use it:

var userid = "USER0001";
var message = "Access denied";
var box = new RichTextBox
              {
                  Dock = DockStyle.Fill,
                  Font = new Font("Courier New", 10)
              };

box.AppendText("[" + DateTime.Now.ToShortTimeString() + "]", Color.Red);
box.AppendText(" ");
box.AppendText(userid, Color.Green);
box.AppendText(": ");
box.AppendText(message, Color.Blue);
box.AppendText(Environment.NewLine);

new Form {Controls = {box}}.ShowDialog();

Note that you may notice some flickering if you're outputting a lot of messages. See this C# Corner article for ideas on how to reduce RichTextBox flicker.

How to tell CRAN to install package dependencies automatically?

On your own system, try

install.packages("foo", dependencies=...)

with the dependencies= argument is documented as

dependencies: logical indicating to also install uninstalled packages
      which these packages depend on/link to/import/suggest (and so
      on recursively).  Not used if ‘repos = NULL’.  Can also be a
      character vector, a subset of ‘c("Depends", "Imports",
      "LinkingTo", "Suggests", "Enhances")’.

      Only supported if ‘lib’ is of length one (or missing), so it
      is unambiguous where to install the dependent packages.  If
      this is not the case it is ignored, with a warning.

      The default, ‘NA’, means ‘c("Depends", "Imports",
      "LinkingTo")’.

      ‘TRUE’ means (as from R 2.15.0) to use ‘c("Depends",
      "Imports", "LinkingTo", "Suggests")’ for ‘pkgs’ and
      ‘c("Depends", "Imports", "LinkingTo")’ for added
      dependencies: this installs all the packages needed to run
      ‘pkgs’, their examples, tests and vignettes (if the package
      author specified them correctly).

so you probably want a value TRUE.

In your package, list what is needed in Depends:, see the Writing R Extensions manual which is pretty clear on this.

Readably print out a python dict() sorted by key

I had the same problem you had. I used a for loop with the sorted function passing in the dictionary like so:

for item in sorted(mydict):
    print(item)

PostgreSQL return result set as JSON array?

Also if you want selected field from table and aggregated then as array .

SELECT json_agg(json_build_object('data_a',a,
                                  'data_b',b,
))  from t;

The result will come .

 [{'data_a':1,'data_b':'value1'}
  {'data_a':2,'data_b':'value2'}]

All ASP.NET Web API controllers return 404

I have solved similar problem by attaching with debugger to application init. Just start webserver (for example, access localhost), attach to w3wp and see, if app initialization finished correctly. In my case there was exception, and controllers was not registered.

MySQL - Meaning of "PRIMARY KEY", "UNIQUE KEY" and "KEY" when used together while creating a table

Just to add to the other answers, the documentation gives this explanation:

  • KEY is normally a synonym for INDEX. The key attribute PRIMARY KEY can also be specified as just KEY when given in a column definition. This was implemented for compatibility with other database systems.

  • A UNIQUE index creates a constraint such that all values in the index must be distinct. An error occurs if you try to add a new row with a key value that matches an existing row. For all engines, a UNIQUE index permits multiple NULL values for columns that can contain NULL.

  • A PRIMARY KEY is a unique index where all key columns must be defined as NOT NULL. If they are not explicitly declared as NOT NULL, MySQL declares them so implicitly (and silently). A table can have only one PRIMARY KEY. The name of a PRIMARY KEY is always PRIMARY, which thus cannot be used as the name for any other kind of index.

Creating a UIImage from a UIColor to use as a background image for UIButton

Add the dots to all values:

[[UIColor colorWithRed:222./255. green:227./255. blue: 229./255. alpha:1] CGColor]) ;

Otherwise, you are dividing float by int.

Remove the newline character in a list read from a file

You want the String.strip(s[, chars]) function, which will strip out whitespace characters or whatever characters (such as '\n') you specify in the chars argument.

See http://docs.python.org/release/2.3/lib/module-string.html

Create an Android GPS tracking application

The source code for the Android mobile application open-gpstracker which you appreciated is available here.

You can checkout the code using SVN client application or via Git:

Debugging the source code will surely help you.

Export to xls using angularjs

When I needed something alike, ng-csv and other solutions here didn't completely help. My data was in $scope and there were no tables showing it. So, I built a directive to export given data to Excel using Sheet.js (xslsx.js) and FileSaver.js.

Here is my solution packed.

For example, the data is:

$scope.jsonToExport = [
    {
      "col1data": "1",
      "col2data": "Fight Club",
      "col3data": "Brad Pitt"
    },
    {
      "col1data": "2",
      "col2data": "Matrix Series",
      "col3data": "Keanu Reeves"
    },
    {
      "col1data": "3",
      "col2data": "V for Vendetta",
      "col3data": "Hugo Weaving"
    }
];

I had to prepare data as array of arrays for my directive in my controller:

$scope.exportData = [];
// Headers:
$scope.exportData.push(["#", "Movie", "Actor"]);
// Data:
angular.forEach($scope.jsonToExport, function(value, key) {
  $scope.exportData.push([value.col1data, value.col2data, value.col3data]);
});

Finally, add directive to my template. It shows a button. (See the fiddle).

<div excel-export export-data="exportData" file-name="{{fileName}}"></div>

Angular2: Cannot read property 'name' of undefined

This worked for me:

export class Hero{
   id: number;
   name: string;

   public Hero(i: number, n: string){
     this.id = 0;
     this.name = '';
   }
 }

and make sure you initialize as well selectedHero

selectedHero: Hero = new Hero();

How to know/change current directory in Python shell?

You can try this:

import os

current_dir = os.path.dirname(os.path.abspath(__file__))   # Can also use os.getcwd()
print(current_dir)                                         # prints(say)- D:\abc\def\ghi\jkl\mno"
new_dir = os.chdir('..\\..\\..\\')                         
print(new_dir)                                             # prints "D:\abc\def\ghi"


HTML5 pattern for formatting input box to take date mm/dd/yyyy?

I've converted the http://html5pattern.com/Dates Full Date Validation (YYYY-MM-DD) to DD/MM/YYYY Brazilian format:

pattern='(?:((?:0[1-9]|1[0-9]|2[0-9])\/(?:0[1-9]|1[0-2])|(?:30)\/(?!02)(?:0[1-9]|1[0-2])|31\/(?:0[13578]|1[02]))\/(?:19|20)[0-9]{2})'

Windows ignores JAVA_HOME: how to set JDK as default?

On Windows, the java executable uses the Windows Registry to locate the default version of Java to run.

The copy of java.exe to run is found by using the PATH environment variable. Unless you take steps to change this, by default a copy will be found in the Windows directory. Since this copy isn't in a Java runtime directory, it locates one by looking at the registry.

So, you either need to modify the registry, or put the version of Java you want before the Windows directory in your PATH.

Convert multiple rows into one with comma as separator

This should work for you. Tested all the way back to SQL 2000.

create table #user (username varchar(25))

insert into #user (username) values ('Paul')
insert into #user (username) values ('John')
insert into #user (username) values ('Mary')

declare @tmp varchar(250)
SET @tmp = ''
select @tmp = @tmp + username + ', ' from #user

select SUBSTRING(@tmp, 0, LEN(@tmp))

Python safe method to get value of nested dictionary

A solution I've used that is similar to the double get but with the additional ability to avoid a TypeError using if else logic:

    value = example_dict['key1']['key2'] if example_dict.get('key1') and example_dict['key1'].get('key2') else default_value

However, the more nested the dictionary the more cumbersome this becomes.

Daemon Threads Explanation

Let's say you're making some kind of dashboard widget. As part of this, you want it to display the unread message count in your email box. So you make a little thread that will:

  1. Connect to the mail server and ask how many unread messages you have.
  2. Signal the GUI with the updated count.
  3. Sleep for a little while.

When your widget starts up, it would create this thread, designate it a daemon, and start it. Because it's a daemon, you don't have to think about it; when your widget exits, the thread will stop automatically.

How to programmatically set style attribute in a view

You can do style attributes like so:

Button myButton = new Button(this, null,android.R.attr.buttonBarButtonStyle);

in place of:

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/btn"
    style="?android:attr/buttonBarButtonStyle"

    />

Determine file creation date in Java

I've solved this problem using JDK 7 with this code:

package FileCreationDate;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.Date;
import java.util.concurrent.TimeUnit;

public class Main
{
    public static void main(String[] args) {

        File file = new File("c:\\1.txt");
        Path filePath = file.toPath();

        BasicFileAttributes attributes = null;
        try
        {
            attributes =
                    Files.readAttributes(filePath, BasicFileAttributes.class);
        }
        catch (IOException exception)
        {
            System.out.println("Exception handled when trying to get file " +
                    "attributes: " + exception.getMessage());
        }
        long milliseconds = attributes.creationTime().to(TimeUnit.MILLISECONDS);
        if((milliseconds > Long.MIN_VALUE) && (milliseconds < Long.MAX_VALUE))
        {
            Date creationDate =
                    new Date(attributes.creationTime().to(TimeUnit.MILLISECONDS));

            System.out.println("File " + filePath.toString() + " created " +
                    creationDate.getDate() + "/" +
                    (creationDate.getMonth() + 1) + "/" +
                    (creationDate.getYear() + 1900));
        }
    }
}

What does $1 mean in Perl?

Since you asked about the capture groups, you might want to know about $+ too... Pretty useful...

use Data::Dumper;
$text = "hiabc ihabc ads byexx eybxx";
while ($text =~ /(hi|ih)abc|(bye|eyb)xx/igs)
{
    print Dumper $+;
}

OUTPUT:
$VAR1 = 'hi';
$VAR1 = 'ih';
$VAR1 = 'bye';
$VAR1 = 'eyb';

Collections sort(List<T>,Comparator<? super T>) method example

This might be simplest way -

Collections.sort(listOfStudent,new Comparator<Student>(){
                     public int compare(Student s1,Student s2){
                           // Write your logic here.
                     }});

Using Java 8(lambda expression) -

listOfStudent.sort((s1, s2) -> s1.age - s2.age); 

Finding first and last index of some value in a list in Python

If you are searching for the index of the last occurrence of myvalue in mylist:

len(mylist) - mylist[::-1].index(myvalue) - 1

Add a default value to a column through a migration

**Rails 4.X +**

As of Rails 4 you can't generate a migration to add a column to a table with a default value, The following steps add a new column to an existing table with default value true or false.

1. Run the migration from command line to add the new column

$ rails generate migration add_columnname_to_tablename columnname:boolean

The above command will add a new column in your table.

2. Set the new column value to TRUE/FALSE by editing the new migration file created.

class AddColumnnameToTablename < ActiveRecord::Migration
  def change
    add_column :table_name, :column_name, :boolean, default: false
  end
end

**3. To make the changes into your application database table, run the following command in terminal**

$ rake db:migrate

React Error: Target Container is not a DOM Element

Also you can do something like that:

document.addEventListener("DOMContentLoaded", function(event) {
  React.renderComponent(
    CardBox({url: "/cards/?format=json", pollInterval: 2000}),
    document.getElementById("content")
  );
})

The DOMContentLoaded event fires when the initial HTML document has been completely loaded and parsed, without waiting for stylesheets, images, and subframes to finish loading.

Python vs Bash - In which kind of tasks each one outruns the other performance-wise?

I don't know if this is accurate, but I have found that python/ruby works much better for scripts that have a lot of mathematical computations. Otherwise you have to use dc or some other "arbitrary precision calculator". It just becomes a very big pain. With python you have much more control over floats vs ints and it is much easier to perform a lot of computations and sometimes.

In particular, I would never work with a bash script to handle binary information or bytes. Instead I would use something like python (maybe) or C++ or even Node.JS.

How do I create a table based on another table

select * into newtable from oldtable

How can I use UserDefaults in Swift?

Swift 5 and above:

let defaults = UserDefaults.standard

defaults.set(25, forKey: "Age")
let savedInteger = defaults.integer(forKey: "Age")

defaults.set(true, forKey: "UseFaceID")
let savedBoolean = defaults.bool(forKey: "UseFaceID")

defaults.set(CGFloat.pi, forKey: "Pi")
defaults.set("Your Name", forKey: "Name")
defaults.set(Date(), forKey: "LastRun")


let array = ["Hello", "World"]
defaults.set(array, forKey: "SavedArray")


let savedArray = defaults.object(forKey: "SavedArray") as? [String] ?? [String()

let dict = ["Name": "Your", "Country": "YourCountry"]
defaults.set(dict, forKey: "SavedDict")

let savedDictionary = defaults.object(forKey: "SavedDictionary") as? [String: String] ?? [String: String]()

:)

How can I clear previous output in Terminal in Mac OS X?

clear && printf '\e[3J'

clears out everything, and it works well on OS X as well. Very neat.

Why SpringMVC Request method 'GET' not supported?

Change

@RequestMapping(value = "/test", method = RequestMethod.POST)

To

@RequestMapping(value = "/test", method = RequestMethod.GET)

Converting Python dict to kwargs?

Use the double-star (aka double-splat?) operator:

func(**{'type':'Event'})

is equivalent to

func(type='Event')

Python: Best way to add to sys.path relative to the current running script

This one works best for me. Use:

os.path.abspath('')

On mac it should print something like:

'/Users/<your username>/<path_to_where_you_at>'

To get the abs path to the current wd, this one is better because now you can go up if you want, like this:

os.path.abspath('../')

And now:

 '/Users/<your username>/'

So if you wanna import utils from here '/Users/<your username>/'
All you've got left to do is:

import sys
sys.path.append(os.path.abspath('../'))

How to get video duration, dimension and size in PHP?

https://github.com/JamesHeinrich/getID3 download getid3 zip and than only getid3 named folder copy paste in project folder and use it as below show...

<?php
        require_once('/fire/scripts/lib/getid3/getid3/getid3.php');
        $getID3 = new getID3();
        $filename="/fire/My Documents/video/ferrari1.mpg";
        $fileinfo = $getID3->analyze($filename);

        $width=$fileinfo['video']['resolution_x'];
        $height=$fileinfo['video']['resolution_y'];

        echo $fileinfo['video']['resolution_x']. 'x'. $fileinfo['video']['resolution_y'];
        echo '<pre>';print_r($fileinfo);echo '</pre>';
?>

How to Delete a topic in apache kafka

Deletion of a topic has been supported since 0.8.2.x version. You have to enable topic deletion (setting delete.topic.enable to true) on all brokers first.

Note: Ever since 1.0.x, the functionality being stable, delete.topic.enable is by default true.

Follow this step by step process for manual deletion of topics

  1. Stop Kafka server
  2. Delete the topic directory, on each broker (as defined in the logs.dirs and log.dir properties) with rm -rf command
  3. Connect to Zookeeper instance: zookeeper-shell.sh host:port
  4. From within the Zookeeper instance:
    1. List the topics using: ls /brokers/topics
    2. Remove the topic folder from ZooKeeper using: rmr /brokers/topics/yourtopic
    3. Exit the Zookeeper instance (Ctrl+C)
  5. Restart Kafka server
  6. Confirm if it was deleted or not by using this command kafka-topics.sh --list --zookeeper host:port

How to send parameters with jquery $.get()

Try this:

$.ajax({
    type: 'get',
    url: 'manageproducts.do',
    data: 'option=1',
    success: function(data) {

        availableProductNames = data.split(",");

        alert(availableProductNames);

    }
});

Also You have a few errors in your sample code, not sure if that was causing the error or it was just a typo upon entering the question.

WMI "installed" query different from add/remove programs list?

Installed products consist of installed software elements and features so it's worth checking wmic alias's for PRODUCT as well as checking SOFTWAREELEMENT and SOFTWAREFEATURE:

wmic product get name,version

wmic softwareelement get name,version

wmic softwarefeature get name,version

What is the difference between i++ & ++i in a for loop?

JLS§14.14.1, The basic for Statement, makes it clear that the ForUpdate expression(s) are evaluated and the value(s) are discarded. The effect is to make the two forms identical in the context of a for statement.

Redirect parent window from an iframe action

This will solve the misery.

<script>parent.location='http://google.com';</script>

ExecuteReader requires an open and available Connection. The connection's current state is Connecting

Sorry for only commenting in the first place, but i'm posting almost every day a similar comment since many people think that it would be smart to encapsulate ADO.NET functionality into a DB-Class(me too 10 years ago). Mostly they decide to use static/shared objects since it seems to be faster than to create a new object for any action.

That is neither a good idea in terms of peformance nor in terms of fail-safety.

Don't poach on the Connection-Pool's territory

There's a good reason why ADO.NET internally manages the underlying Connections to the DBMS in the ADO-NET Connection-Pool:

In practice, most applications use only one or a few different configurations for connections. This means that during application execution, many identical connections will be repeatedly opened and closed. To minimize the cost of opening connections, ADO.NET uses an optimization technique called connection pooling.

Connection pooling reduces the number of times that new connections must be opened. The pooler maintains ownership of the physical connection. It manages connections by keeping alive a set of active connections for each given connection configuration. Whenever a user calls Open on a connection, the pooler looks for an available connection in the pool. If a pooled connection is available, it returns it to the caller instead of opening a new connection. When the application calls Close on the connection, the pooler returns it to the pooled set of active connections instead of closing it. Once the connection is returned to the pool, it is ready to be reused on the next Open call.

So obviously there's no reason to avoid creating,opening or closing connections since actually they aren't created,opened and closed at all. This is "only" a flag for the connection pool to know when a connection can be reused or not. But it's a very important flag, because if a connection is "in use"(the connection pool assumes), a new physical connection must be openend to the DBMS what is very expensive.

So you're gaining no performance improvement but the opposite. If the maximum pool size specified (100 is the default) is reached, you would even get exceptions(too many open connections ...). So this will not only impact the performance tremendously but also be a source for nasty errors and (without using Transactions) a data-dumping-area.

If you're even using static connections you're creating a lock for every thread trying to access this object. ASP.NET is a multithreading environment by nature. So theres a great chance for these locks which causes performance issues at best. Actually sooner or later you'll get many different exceptions(like your ExecuteReader requires an open and available Connection).

Conclusion:

  • Don't reuse connections or any ADO.NET objects at all.
  • Don't make them static/shared(in VB.NET)
  • Always create, open(in case of Connections), use, close and dispose them where you need them(f.e. in a method)
  • use the using-statement to dispose and close(in case of Connections) implicitely

That's true not only for Connections(although most noticable). Every object implementing IDisposable should be disposed(simplest by using-statement), all the more in the System.Data.SqlClient namespace.

All the above speaks against a custom DB-Class which encapsulates and reuse all objects. That's the reason why i commented to trash it. That's only a problem source.


Edit: Here's a possible implementation of your retrievePromotion-method:

public Promotion retrievePromotion(int promotionID)
{
    Promotion promo = null;
    var connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["MainConnStr"].ConnectionString;
    using (SqlConnection connection = new SqlConnection(connectionString))
    {
        var queryString = "SELECT PromotionID, PromotionTitle, PromotionURL FROM Promotion WHERE PromotionID=@PromotionID";
        using (var da = new SqlDataAdapter(queryString, connection))
        {
            // you could also use a SqlDataReader instead
            // note that a DataTable does not need to be disposed since it does not implement IDisposable
            var tblPromotion = new DataTable();
            // avoid SQL-Injection
            da.SelectCommand.Parameters.Add("@PromotionID", SqlDbType.Int);
            da.SelectCommand.Parameters["@PromotionID"].Value = promotionID;
            try
            {
                connection.Open(); // not necessarily needed in this case because DataAdapter.Fill does it otherwise 
                da.Fill(tblPromotion);
                if (tblPromotion.Rows.Count != 0)
                {
                    var promoRow = tblPromotion.Rows[0];
                    promo = new Promotion()
                    {
                        promotionID    = promotionID,
                        promotionTitle = promoRow.Field<String>("PromotionTitle"),
                        promotionUrl   = promoRow.Field<String>("PromotionURL")
                    };
                }
            }
            catch (Exception ex)
            {
                // log this exception or throw it up the StackTrace
                // we do not need a finally-block to close the connection since it will be closed implicitely in an using-statement
                throw;
            }
        }
    }
    return promo;
}

Javascript to set hidden form value on drop down change

This is with jQuery.

$('#selectFormElement').change( function() {
    $('#hiddenFormElement').val('newValue');
} );

In the html

<select id="selectFormElement" name="..."> ... </select>
<input type="hidden" name="..." id="hiddenFormElement" />

Handle Guzzle exception and get HTTP body

None of the above responses are working for error that has no body but still has some describing text. For me, it was SSL certificate problem: unable to get local issuer certificate error. So I looked right into the code, because doc does't really say much, and did this (in Guzzle 7.1):

try {
    // call here
} catch (\GuzzleHttp\Exception\RequestException $e) {
    if ($e->hasResponse()) {
        $response = $e->getResponse();
        // message is in $response->getReasonPhrase()
    } else {
        $response = $e->getHandlerContext();
        if (isset($response['error'])) {
            // message is in $response['error']
        } else {
            // Unknown error occured!
        }
    }
}

How to print all session variables currently set?

session_start();
echo '<pre>';var_dump($_SESSION);echo '</pre>';
// or
echo '<pre>';print_r($_SESSION);echo '</pre>';

NOTE: session_start(); line is must then only you will able to print the value $_SESSION

C++ STL Vectors: Get iterator from index?

Also; auto it = std::next(v.begin(), index);

Update: Needs a C++11x compliant compiler

Convert date to day name e.g. Mon, Tue, Wed

For other language use day of week to recognize day name

For example for Persian use below code

$dayName = getDayName(date('w', strtotime('2019-11-14')));

    function getDayName($dayOfWeek) {

        switch ($dayOfWeek){
            case 6:
                return '????';
            case 0:
                return '?? ????';
            case 1:
                return '?? ????';
            case 2:
                return '?? ????';
            case 3:
                return '???? ????';
            case 4:
                return '??? ????';
            case 5:
                return '????';
            default:
                return '';
        }

    }

More info : https://www.php.net/manual/en/function.date.php

Extract value of attribute node via XPath

As answered above:

//Parent[@id='1']/Children/child/@name 

will only output the name attribute of the 4 child nodes belonging to the Parent specified by its predicate [@id=1]. You'll then need to change the predicate to [@id=2] to get the set of child nodes for the next Parent.

However, if you ignore the Parent node altogether and use:

//child/@name

you can select name attribute of all child nodes in one go.

name="Child_2"
name="Child_4"
name="Child_1"
name="Child_3"
name="Child_1"
name="Child_2"
name="Child_4"
name="Child_3"

Given a class, see if instance has method (Ruby)

Try Foo.instance_methods.include? :bar

Failed to resolve: com.google.firebase:firebase-core:9.0.0

Need to Update

Android SDK : SDK Tools -> Support Repository -> Google Repository

After updating the Android SDK need to sync gradle build in Android studio.

Compare a date string to datetime in SQL Server?

Just compare the year, month and day values.

Declare @DateToSearch DateTime
Set @DateToSearch = '14 AUG 2008'

SELECT * 
FROM table1
WHERE Year(column_datetime) = Year(@DateToSearch)
      AND Month(column_datetime) = Month(@DateToSearch)
      AND Day(column_datetime) = Day(@DateToSearch)

How to compare LocalDate instances Java 8

LocalDate ld ....;
LocalDateTime ldtime ...;

ld.isEqual(LocalDate.from(ldtime));

How to hide column of DataGridView when using custom DataSource?

You have to hide the column at the grid view control rather than at the data source. Hiding it at the data source it will not render to the grid view at all, therefore you won't be able to access the value in the grid view. Doing it the way you're suggesting, you would have to access the column value through the data source as opposed to the grid view.

To hide the column on the grid view control, you can use code like this:

dataGridView1.Columns[0].Visible = false;

To access the column from the data source, you could try something like this:

object colValue = ((DataTable)dataGridView.DataSource).Rows[dataSetIndex]["ColumnName"];

Format number to always show 2 decimal places

_x000D_
_x000D_
function number_format(string,decimals=2,decimal=',',thousands='.',pre='R$ ',pos=' Reais'){_x000D_
  var numbers = string.toString().match(/\d+/g).join([]);_x000D_
  numbers = numbers.padStart(decimals+1, "0");_x000D_
  var splitNumbers = numbers.split("").reverse();_x000D_
  var mask = '';_x000D_
  splitNumbers.forEach(function(d,i){_x000D_
    if (i == decimals) { mask = decimal + mask; }_x000D_
    if (i>(decimals+1) && ((i-2)%(decimals+1))==0) { mask = thousands + mask; }_x000D_
    mask = d + mask;_x000D_
  });_x000D_
  return pre + mask + pos;_x000D_
}_x000D_
var element = document.getElementById("format");_x000D_
var money= number_format("10987654321",2,',','.');_x000D_
element.innerHTML = money;
_x000D_
#format{_x000D_
display:inline-block;_x000D_
padding:10px;_x000D_
border:1px solid #ddd;_x000D_
background:#f5f5f5;_x000D_
}
_x000D_
<div id='format'>Test 123456789</div>
_x000D_
_x000D_
_x000D_

How to escape special characters in building a JSON string?

Everyone is talking about how to escape ' in a '-quoted string literal. There's a much bigger issue here: single-quoted string literals aren't valid JSON. JSON is based on JavaScript, but it's not the same thing. If you're writing an object literal inside JavaScript code, fine; if you actually need JSON, you need to use ".

With double-quoted strings, you won't need to escape the '. (And if you did want a literal " in the string, you'd use \".)

cannot convert 'std::basic_string<char>' to 'const char*' for argument '1' to 'int system(const char*)'

The addition of a string literal with an std::string yields another std::string. system expects a const char*. You can use std::string::c_str() for that:

string name = "john";
string tmp = " quickscan.exe resolution 300 selectscanner jpg showui showprogress filename '"+name+".jpg'"
system(tmp.c_str());

Clear a terminal screen for real

tput reset

That will do the trick!

Android Gallery on Android 4.4 (KitKat) returns different URI for Intent.ACTION_GET_CONTENT

Please try to avoid using takePersistableUriPermission method because it raised runtime exception for me. /** * Select from gallery. */

public void selectFromGallery() {
    if (Build.VERSION.SDK_INT < AppConstants.KITKAT_API_VERSION) {

        Intent intent = new Intent(); 
        intent.setType("image/*");
        intent.setAction(Intent.ACTION_GET_CONTENT);
        ((Activity)mCalledContext).startActivityForResult(intent,AppConstants.GALLERY_INTENT_CALLED);

    } else {

        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.setType("image/*");
        ((Activity)mCalledContext).startActivityForResult(intent, AppConstants.GALLERY_AFTER_KITKAT_INTENT_CALLED);
    }
}

OnActivity for result to handle the image data:

@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    //gallery intent result handling before kit-kat version
    if(requestCode==AppConstants.GALLERY_INTENT_CALLED 
            && resultCode == RESULT_OK) {

        Uri selectedImage = data.getData();
        String[] filePathColumn = {MediaStore.Images.Media.DATA};
        Cursor cursor = getContentResolver().query(selectedImage,filePathColumn, null, null, null);
        cursor.moveToFirst();
        int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
        String filePath = cursor.getString(columnIndex);
        cursor.close();
        photoFile = new File(filePath);
        mImgCropping.startCropImage(photoFile,AppConstants.REQUEST_IMAGE_CROP);

    }
    //gallery intent result handling after kit-kat version
    else if (requestCode == AppConstants.GALLERY_AFTER_KITKAT_INTENT_CALLED 
            && resultCode == RESULT_OK) {

        Uri selectedImage = data.getData();
        InputStream input = null;
        OutputStream output = null;

        try {
            //converting the input stream into file to crop the 
            //selected image from sd-card.
            input = getApplicationContext().getContentResolver().openInputStream(selectedImage);
            try {
                photoFile = mImgCropping.createImageFile();
            } catch (IOException e) {
                e.printStackTrace();
            }catch(Exception e) {
                e.printStackTrace();
            }
            output = new FileOutputStream(photoFile);

            int read = 0;
            byte[] bytes = new byte[1024];

            while ((read = input.read(bytes)) != -1) {
                try {
                    output.write(bytes, 0, read);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }


    }

Spark DataFrame TimestampType - how to get Year, Month, Day values from field?

Since Spark 1.5 you can use a number of date processing functions:

import datetime
from pyspark.sql.functions import year, month, dayofmonth

elevDF = sc.parallelize([
    (datetime.datetime(1984, 1, 1, 0, 0), 1, 638.55),
    (datetime.datetime(1984, 1, 1, 0, 0), 2, 638.55),
    (datetime.datetime(1984, 1, 1, 0, 0), 3, 638.55),
    (datetime.datetime(1984, 1, 1, 0, 0), 4, 638.55),
    (datetime.datetime(1984, 1, 1, 0, 0), 5, 638.55)
]).toDF(["date", "hour", "value"])

elevDF.select(
    year("date").alias('year'), 
    month("date").alias('month'), 
    dayofmonth("date").alias('day')
).show()
# +----+-----+---+
# |year|month|day|
# +----+-----+---+
# |1984|    1|  1|
# |1984|    1|  1|
# |1984|    1|  1|
# |1984|    1|  1|
# |1984|    1|  1|
# +----+-----+---+

You can use simple map as with any other RDD:

elevDF = sqlContext.createDataFrame(sc.parallelize([
        Row(date=datetime.datetime(1984, 1, 1, 0, 0), hour=1, value=638.55),
        Row(date=datetime.datetime(1984, 1, 1, 0, 0), hour=2, value=638.55),
        Row(date=datetime.datetime(1984, 1, 1, 0, 0), hour=3, value=638.55),
        Row(date=datetime.datetime(1984, 1, 1, 0, 0), hour=4, value=638.55),
        Row(date=datetime.datetime(1984, 1, 1, 0, 0), hour=5, value=638.55)]))

(elevDF
 .map(lambda (date, hour, value): (date.year, date.month, date.day))
 .collect())

and the result is:

[(1984, 1, 1), (1984, 1, 1), (1984, 1, 1), (1984, 1, 1), (1984, 1, 1)]

Btw: datetime.datetime stores an hour anyway so keeping it separately seems to be a waste of memory.

How to execute AngularJS controller function on page load?

Another alternative:

var myInit = function () {
    //...
};
angular.element(document).ready(myInit);

(via https://stackoverflow.com/a/30258904/148412)

Select top 2 rows in Hive

Here I think it's worth mentioning SORT BY and ORDER BY both clauses and why they different,

SELECT * FROM <table_name> SORT BY <column_name> DESC LIMIT 2

If you are using SORT BY clause it sort data per reducer which means if you have more than one MapReduce task it will result partially ordered data. On the other hand, the ORDER BY clause will result in ordered data for the final Reduce task. To understand more please refer to this link.

SELECT * FROM <table_name> ORDER BY <column_name> DESC LIMIT 2

Note: Finally, Even though the accepted answer contains SORT BY clause, I mostly prefer to use ORDER BY clause for the general use case to avoid any data loss.

Select query with date condition

select Qty, vajan, Rate,Amt,nhamali,ncommission,ntolai from SalesDtl,SalesMSt where SalesDtl.PurEntryNo=1 and SalesMST.SaleDate=  (22/03/2014) and SalesMST.SaleNo= SalesDtl.SaleNo;

That should work.

EditText onClickListener in Android

I had this same problem. The code is fine but make sure you change the focusable value of the EditText to false.

<EditText
android:id="@+id/date"
android:focusable="false"/>

I hope this helps anyone who has had a similar problem!

Bulk Record Update with SQL

Or you can simply update without using join like this:

Update t1 set  t1.Description = t2.Description from @tbl2 t2,tbl1 t1
where t1.ID= t2.ID

How to display special characters in PHP

This works for me:

Create/edit .htaccess file with these lines:

AddDefaultCharset UTF-8
AddCharset UTF-8 .php

If you prefer create/edit php.ini:

default_charset = "utf-8"

Sources:

MySQL error 2006: mysql server has gone away

For Vagrant Box, make sure you allocate enough memory to the box

config.vm.provider "virtualbox" do |vb|
  vb.memory = "4096"
end

Karma: Running a single test file from command line

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

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

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

Then in CLI:

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

How do you use script variables in psql?

Variables in psql suck. If you want to declare an integer, you have to enter the integer, then do a carriage return, then end the statement in a semicolon. Observe:

Let's say I want to declare an integer variable my_var and insert it into a table test:

Example table test:

thedatabase=# \d test;
                         Table "public.test"
 Column |  Type   |                     Modifiers                     
--------+---------+---------------------------------------------------
 id     | integer | not null default nextval('test_id_seq'::regclass)
Indexes:
    "test_pkey" PRIMARY KEY, btree (id)

Clearly, nothing in this table yet:

thedatabase=# select * from test;
 id 
----
(0 rows)

We declare a variable. Notice how the semicolon is on the next line!

thedatabase=# \set my_var 999
thedatabase=# ;

Now we can insert. We have to use this weird ":''" looking syntax:

thedatabase=# insert into test(id) values (:'my_var');
INSERT 0 1

It worked!

thedatabase=# select * from test;
 id  
-----
 999
(1 row)

Explanation:

So... what happens if we don't have the semicolon on the next line? The variable? Have a look:

We declare my_var without the new line.

thedatabase=# \set my_var 999;

Let's select my_var.

thedatabase=# select :'my_var';
 ?column? 
----------
 999;
(1 row)

WTF is that? It's not an integer, it's a string 999;!

thedatabase=# select 999;
 ?column? 
----------
      999
(1 row)

How can I make Visual Studio wrap lines at 80 characters?

Unless someone can recommend a free tool to do this, you can achieve this with ReSharper:

ReSharper >> Options... >> Languages/C# >> Line Breaks and Wrapping

  • Check "Wrap long lines"
  • Set "Right Margin (columns)" to the required value (default is 120)

Hope that helps.

How long to brute force a salted SHA-512 hash? (salt provided)

I want to know the time to brute force for when the password is a dictionary word and also when it is not a dictionary word.

Dictionary password

Ballpark figure: there are about 1,000,000 English words, and if a hacker can compute about 10,000 SHA-512 hashes a second (update: see comment by CodesInChaos, this estimate is very low), 1,000,000 / 10,000 = 100 seconds. So it would take just over a minute to crack a single-word dictionary password for a single user. If the user concatenates two dictionary words, you're in the area of a few days, but still very possible if the attacker is cares enough. More than that and it starts getting tough.

Random password

If the password is a truly random sequence of alpha-numeric characters, upper and lower case, then the number of possible passwords of length N is 60^N (there are 60 possible characters). We'll do the calculation the other direction this time; we'll ask: What length of password could we crack given a specific length of time? Just use this formula:

N = Log60(t * 10,000) where t is the time spent calculating hashes in seconds (again assuming 10,000 hashes a second).

1 minute:    3.2
5 minute:    3.6
30 minutes:  4.1
2 hours:     4.4
3 days:      5.2

So given a 3 days we'd be able to crack the password if it's 5 characters long.

This is all very ball-park, but you get the idea. Update: see comment below, it's actually possible to crack much longer passwords than this.

What's going on here?

Let's clear up some misconceptions:

  • The salt doesn't make it slower to calculate hashes, it just means they have to crack each user's password individually, and pre-computed hash tables (buzz-word: rainbow tables) are made completely useless. If you don't have a precomputed hash-table, and you're only cracking one password hash, salting doesn't make any difference.

  • SHA-512 isn't designed to be hard to brute-force. Better hashing algorithms like BCrypt, PBKDF2 or SCrypt can be configured to take much longer to compute, and an average computer might only be able to compute 10-20 hashes a second. Read This excellent answer about password hashing if you haven't already.

  • update: As written in the comment by CodesInChaos, even high entropy passwords (around 10 characters) could be bruteforced if using the right hardware to calculate SHA-512 hashes.


Notes on accepted answer:

The accepted answer as of September 2014 is incorrect and dangerously wrong:

In your case, breaking the hash algorithm is equivalent to finding a collision in the hash algorithm. That means you don't need to find the password itself (which would be a preimage attack)... Finding a collision using a birthday attack takes O(2^n/2) time, where n is the output length of the hash function in bits.

The birthday attack is completely irrelevant to cracking a given hash. And this is in fact a perfect example of a preimage attack. That formula and the next couple of paragraphs result in dangerously high and completely meaningless values for an attack time. As demonstrated above it's perfectly possible to crack salted dictionary passwords in minutes.

The low entropy of typical passwords makes it possible that there is a relatively high chance of one of your users using a password from a relatively small database of common passwords...

That's why generally hashing and salting alone is not enough, you need to install other safety mechanisms as well. You should use an artificially slowed down entropy-enducing method such as PBKDF2 described in PKCS#5...

Yes, please use an algorithm that is slow to compute, but what is "entropy-enducing"? Putting a low entropy password through a hash doesn't increase entropy. It should preserve entropy, but you can't make a rubbish password better with a hash, it doesn't work like that. A weak password put through PBKDF2 is still a weak password.

enum - getting value of enum on string conversion

I implemented access using the following

class D(Enum):
    x = 1
    y = 2

    def __str__(self):
        return '%s' % self.value

now I can just do

print(D.x) to get 1 as result.

You can also use self.name in case you wanted to print x instead of 1.

Oracle to_date, from mm/dd/yyyy to dd-mm-yyyy

I suggest you use TO_CHAR() when converting to string. In order to do that, you need to build a date first.

SELECT TO_CHAR(TO_DATE(DAY||'-'||MONTH||'-'||YEAR, 'dd-mm-yyyy'), 'dd-mm-yyyy') AS FORMATTED_DATE
FROM
    (SELECT EXTRACT( DAY FROM
        (SELECT TO_DATE('1/21/2000', 'mm/dd/yyyy')
        FROM DUAL
        )) AS DAY, TO_NUMBER(EXTRACT( MONTH FROM
        (SELECT TO_DATE('1/21/2000', 'mm/dd/yyyy') FROM DUAL
        )), 09) AS MONTH, EXTRACT(YEAR FROM
        (SELECT TO_DATE('1/21/2000', 'mm/dd/yyyy') FROM DUAL
        )) AS YEAR
    FROM DUAL
    );

Accessing localhost of PC from USB connected Android mobile device

How to Easily access LocalHost in Actual Android Device -> Connect your pc with the android device via USB

  1. Go to Chrome inspection click 'f12' or Control+Shift+C

Chrome Inspection tool

  1. Check the bottom of the chrome inspection tool.

  2. Now go to settings in Remote Device Tab.

Remote Devices Tab

  1. check on "Discover USB Device" option as well as check on "Port Forwarding" option.

  2. Now Click on Add Rules, Enter Any Device Port e.g(4880) and in Local Address Enter the Actual Address of the local host in my case e.g (127.0.0.1:480)

  3. After Adding the Rule go to your android studio -> inside your code URL(http://127.0.0.1:4880). Remember to change the port from 480 -> 4880.

  4. Go to Remote Device Tab in Chrome and Click on your connected Device. Add New URL(127.0.0.1:4880) Inspect the Android Device Chrome Browser

Check your Actual Device Chrome Browser and start Debugging the code on Actual Android device.

Parsing JSON in Java without knowing JSON format

Take a look at Jacksons built-in tree model feature.

And your code will be:

public void parse(String json)  {
       JsonFactory factory = new JsonFactory();

       ObjectMapper mapper = new ObjectMapper(factory);
       JsonNode rootNode = mapper.readTree(json);  

       Iterator<Map.Entry<String,JsonNode>> fieldsIterator = rootNode.fields();
       while (fieldsIterator.hasNext()) {

           Map.Entry<String,JsonNode> field = fieldsIterator.next();
           System.out.println("Key: " + field.getKey() + "\tValue:" + field.getValue());
       }
}

What does axis in pandas mean?

Arrays are designed with so-called axis=0 and rows positioned vertically versus axis=1 and columns positioned horizontally. Axis refers to the dimension of the array. Illustration

Xcode variables

Here's a list of the environment variables. I think you might want CURRENT_VARIANT. See also BUILD_VARIANTS.

Detecting iOS / Android Operating system

You also can create Firbase Dynamic links which will work as per your requirement. It supports multiple platforms. This link can be created, manually as well as via programming. You can then embed this link in QR code.

If the target app is installed, the link will redirect user to app. If its not installed it will redirect to Play Store/App store/Any other configured website.

Cannot find firefox binary in PATH. Make sure firefox is installed. OS appears to be: VISTA

For some reason, adding the environment variable didn't work for me.

I was able to specify a path to Firefox in the command line node configuration, as described on this page (grid2).

-browser “browserName=firefox,version=3.6,firefox_binary=c:\Program Files\Mozilla Firefox\firefox.exe ,maxInstances=3, platform=WINDOWS”

Migration: Cannot add foreign key constraint

We cannot add relations, unless related tables gets created. Laravel run migrations order by date of migration files. So if you want to create a relation with a table that exists in 2nd migration file it fails.

I faced the same problem, so I created one more migration file at last to specify all relations.

Schema::table('properties', function(Blueprint $table) {
        $table->foreign('user')->references('id')->on('users')->onDelete('cascade');
        $table->foreign('area')->references('id')->on('areas')->onDelete('cascade');
        $table->foreign('city')->references('id')->on('cities')->onDelete('cascade');
        $table->foreign('type')->references('id')->on('property_types')->onDelete('cascade');
    });

    Schema::table('areas', function(Blueprint $table) {
        $table->foreign('city_id')->references('id')->on('cities')->onDelete('cascade');
    });

Apply global variable to Vuejs

You can use a Global Mixin to affect every Vue instance. You can add data to this mixin, making a value/values available to all vue components.

To make that value Read Only, you can use the method described in this Stack Overflow answer.

Here is an example:

_x000D_
_x000D_
// This is a global mixin, it is applied to every vue instance. 
// Mixins must be instantiated *before* your call to new Vue(...)
Vue.mixin({
  data: function() {
    return {
      get globalReadOnlyProperty() {
        return "Can't change me!";
      }
    }
  }
})

Vue.component('child', {
  template: "<div>In Child: {{globalReadOnlyProperty}}</div>"
});

new Vue({
  el: '#app',
  created: function() {
    this.globalReadOnlyProperty = "This won't change it";
  }
});
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.1.3/vue.js"></script>
<div id="app">
  In Root: {{globalReadOnlyProperty}}
  <child></child>
</div>
_x000D_
_x000D_
_x000D_

Show data on mouseover of circle

I assume that what you want is a tooltip. The easiest way to do this is to append an svg:title element to each circle, as the browser will take care of showing the tooltip and you don't need the mousehandler. The code would be something like

vis.selectAll("circle")
   .data(datafiltered).enter().append("svg:circle")
   ...
   .append("svg:title")
   .text(function(d) { return d.x; });

If you want fancier tooltips, you could use tipsy for example. See here for an example.

How to make div same height as parent (displayed as table-cell)

You have to set the height for the parents (container and child) explicitly, here is another work-around (if you don't want to set that height explicitly):

.child {
  width: 30px;
  background-color: red;
  display: table-cell;
  vertical-align: top;
  position:relative;
}

.content {
  position:absolute;
  top:0;
  bottom:0;
  width:100%;
  background-color: blue;
}

Fiddle

What is the best way to update the entity in JPA

Using executeUpdate() on the Query API is faster because it bypasses the persistent context .However , by-passing persistent context would cause the state of instance in the memory and the actual values of that record in the DB are not synchronized.

Consider the following example :

 Employee employee= (Employee)entityManager.find(Employee.class , 1);
 entityManager
     .createQuery("update Employee set name = \'xxxx\' where id=1")
     .executeUpdate();

After flushing, the name in the DB is updated to the new value but the employee instance in the memory still keeps the original value .You have to call entityManager.refresh(employee) to reload the updated name from the DB to the employee instance.It sounds strange if your codes still have to manipulate the employee instance after flushing but you forget to refresh() the employee instance as the employee instance still contains the original values.

Normally , executeUpdate() is used in the bulk update process as it is faster due to bypassing the persistent context

The right way to update an entity is that you just set the properties you want to updated through the setters and let the JPA to generate the update SQL for you during flushing instead of writing it manually.

   Employee employee= (Employee)entityManager.find(Employee.class ,1);
   employee.setName("Updated Name");

Less than or equal to

There is no => for if.
Use if %energy% GEQ %m2enc%

See if /? for some other details.

How should I set the default proxy to use default credentials?

Seems like in some newer Application the Configuration is different, as i've seen on this Question How to authenticate against a proxy when using the HttpClient class?

<system.net>
    <defaultProxy enabled="true" useDefaultCredentials="true">
         <proxy usesystemdefault="True" />
    </defaultProxy>
</system.net>

Also documented on https://msdn.microsoft.com/en-us/library/dkwyc043.aspx

client denied by server configuration

The error "client denied by server configuration" generally means that somewhere in your configuration are Allow from and Deny from directives that are preventing access. Read the mod_authz_host documentation for more details.

You should be able to solve this in your VirtualHost by adding something like:

<Location />
  Allow from all
  Order Deny,Allow
</Location>

Or alternatively with a Directory directive:

<Directory "D:/Devel/matysart/matysart_dev1">
  Allow from all
  Order Deny,Allow
</Directory>

Some investigation of your Apache configuration files will probably turn up default restrictions on the default DocumentRoot.

How to set up java logging using a properties file? (java.util.logging)

Okay, first intuition is here:

handlers = java.util.logging.FileHandler, java.util.logging.ConsoleHandler
.level = ALL

The Java prop file parser isn't all that smart, I'm not sure it'll handle this. But I'll go look at the docs again....

In the mean time, try:

handlers = java.util.logging.FileHandler
java.util.logging.ConsoleHandler.level = ALL

Update

No, duh, needed more coffee. Nevermind.

While I think more, note that you can use the methods in Properties to load and print a prop-file: it might be worth writing a minimal program to see what java thinks it reads in that file.


Another update

This line:

    FileInputStream configFile = new FileInputStream("/path/to/app.properties"));

has an extra end-paren. It won't compile. Make sure you're working with the class file you think you are.

In C++, what is a virtual base class?

In addition to what has already been said about multiple and virtual inheritance(s), there is a very interesting article on Dr Dobb's Journal: Multiple Inheritance Considered Useful

PHP array delete by value (not key)

Borrowed the logic of underscore.JS _.reject and created two functions (people prefer functions!!)

array_reject_value: This function is simply rejecting the value specified (also works for PHP4,5,7)

function array_reject_value(array &$arrayToFilter, $deleteValue) {
    $filteredArray = array();

    foreach ($arrayToFilter as $key => $value) {
        if ($value !== $deleteValue) {
            $filteredArray[] = $value;
        }
    }

    return $filteredArray;
}

array_reject: This function is simply rejecting the callable method (works for PHP >=5.3)

function array_reject(array &$arrayToFilter, callable $rejectCallback) {

    $filteredArray = array();

    foreach ($arrayToFilter as $key => $value) {
        if (!$rejectCallback($value, $key)) {
            $filteredArray[] = $value;
        }
    }

    return $filteredArray;
}

So in our current example we can use the above functions as follows:

$messages = [312, 401, 1599, 3, 6];
$messages = array_reject_value($messages, 401);

or even better: (as this give us a better syntax to use like the array_filter one)

$messages = [312, 401, 1599, 3, 6];
$messages = array_reject($messages, function ($value) {
    return $value === 401;
});

The above can be used for more complicated stuff like let's say we would like to remove all the values that are greater or equal to 401 we could simply do this:

$messages = [312, 401, 1599, 3, 6];
$greaterOrEqualThan = 401;
$messages = array_reject($messages, function ($value) use $greaterOrEqualThan {
    return $value >= $greaterOrEqualThan;
});

Pull is not possible because you have unmerged files, git stash doesn't work. Don't want to commit

I've had the same error and I solve it with: git merge -s recursive -X theirs origin/master

How to dismiss keyboard for UITextView with return key?

Swift answer:

override func viewDidLoad() {
    super.viewDidLoad()
    let tapGestureReconizer = UITapGestureRecognizer(target: self, action: "tap:")
    view.addGestureRecognizer(tapGestureReconizer)
}

func tap(sender: UITapGestureRecognizer) {
    view.endEditing(true)
}

Finding out the name of the original repository you cloned from in Git

I stumbled on this question trying to get the organization/repo string from a git host like github or gitlab.

This is working for me:

git config --get remote.origin.url | sed -e 's/^git@.*:\([[:graph:]]*\).git/\1/'

It uses sed to replace the output of the git config command with just the organization and repo name.

Something like github/scientist would be matched by the character class [[:graph:]] in the regular expression.

The \1 tells sed to replace everything with just the matched characters.

Real time data graphing on a line chart with html5

In order to complete this thread, I would suggest you to look into:

d3.js

This is a library that helps with tons of javascript visualizations. However the learning curve is quite steep.

nvd3.js

A library that makes it easy to create some d3.js visualizations (with limitations, of course).

Echo newline in Bash prints literal \n

Are you sure you are in bash? Works for me, all four ways:

echo -e "Hello\nworld"
echo -e 'Hello\nworld'
echo Hello$'\n'world
echo Hello ; echo world

Keytool is not recognized as an internal or external command

Execute following command:

set PATH="C:\Program Files (x86)\Java\jre7"

(whichever JRE exists in case of 64bit).

Because your Java Path is not set so you can just do this at command line and then execute the keytool import command.

How do I POST JSON data with cURL?

I know, a lot has been answered to this question but wanted to share where I had the issue of:

curl -X POST http://your-server-end-point -H "Content-Type: application/json" -d @path-of-your-json-file.json

See, I did everything right, Only one thing - "@" I missed before the JSON file path.

I found one relevant go-to document on internet - https://gist.github.com/subfuzion/08c5d85437d5d4f00e58

Hope that might help the few. thanks

How do you uninstall a python package that was installed using distutils?

For Windows 7,

Control Panel --> Programs --> Uninstall

, then

choose the python package to remove.

How to redirect to Login page when Session is expired in Java web application?

How to redirect to Login page when Session is expired in Java web application?

This is a wrong question. You should differentiate between the cases "User is not logged in" and "Session is expired". You basically want to redirect to login page when user is not logged in. Not when session is expired. The currently accepted answer only checks HttpSession#isNew(). But this obviously fails when the user has sent more than one request in the same session when the session is implicitly created by the JSP or what not. E.g. when just pressing F5 on the login page.

As said, you should instead be checking if the user is logged in or not. Given the fact that you're asking this kind of question while standard authentication frameworks like j_security_check, Shiro, Spring Security, etc already transparently manage this (and thus there would be no need to ask this kind of question on them), that can only mean that you're using a homegrown authentication approach.

Assuming that you're storing the logged-in user in the session in some login servlet like below:

@WebServlet("/login")
public class LoginServlet extends HttpServlet {

    @EJB
    private UserService userService;

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.getRequestDispatcher("/WEB-INF/login.jsp").forward(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        User user = userService.find(username, password);

        if (user != null) {
            request.getSession().setAttribute("user", user);
            response.sendRedirect(request.getContextPath() + "/home");
        } else {
            request.setAttribute("error", "Unknown login, try again");
            doGet(request, response);
        }
    }

}

Then you can check for that in a login filter like below:

@WebFilter("/*")
public class LoginFilter implements Filter {

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws ServletException, IOException {    
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;
        HttpSession session = request.getSession(false);
        String loginURI = request.getContextPath() + "/login";

        boolean loggedIn = session != null && session.getAttribute("user") != null;
        boolean loginRequest = request.getRequestURI().equals(loginURI);

        if (loggedIn || loginRequest) {
            chain.doFilter(request, response);
        } else {
            response.sendRedirect(loginURI);
        }
    }

    // ...
}

No need to fiddle around with brittle HttpSession#isNew() checks.

When you use 'badidea' or 'thisisunsafe' to bypass a Chrome certificate/HSTS error, does it only apply for the current site?

This is specific for each site. So if you type that once, you will only get through that site and all other sites will need a similar type-through.

It is also remembered for that site and you have to click on the padlock to reset it (so you can type it again):

enter image description here

Needless to say use of this "feature" is a bad idea and is unsafe - hence the name.

You should find out why the site is showing the error and/or stop using it until they fix it. HSTS specifically adds protections for bad certs to prevent you clicking through them. The fact it's needed suggests there is something wrong with the https connection - like the site or your connection to it has been hacked.

The chrome developers also do change this periodically. They changed it recently from badidea to thisisunsafe so everyone using badidea, suddenly stopped being able to use it. You should not depend on it. As Steffen pointed out in the comments below, it is available in the code should it change again though they now base64 encode it to make it more obscure. The last time they changed they put this comment in the commit:

Rotate the interstitial bypass keyword

The security interstitial bypass keyword hasn't changed in two years and awareness of the bypass has been increased in blogs and social media. Rotate the keyword to help prevent misuse.

I think the message from the Chrome team is clear - you should not use it. It would not surprise me if they removed it completely in future.

If you are using this when using a self-signed certificate for local testing then why not just add your self-signed certificate certificate to your computer's certificate store so you get a green padlock and do not have to type this? Note Chrome insists on a SAN field in certificates now so if just using the old subject field then even adding it to the certificate store will not result in a green padlock.

If you leave the certificate untrusted then certain things do not work. Caching for example is completely ignored for untrusted certificates. As is HTTP/2 Push.

HTTPS is here to stay and we need to get used to using it properly - and not bypassing the warnings with a hack that is liable to change and doesn't work the same as a full HTTPS solution.

How to rename files and folder in Amazon S3?

There is one software where you can play with the s3 bucket for performing different kinds of operation.

Software Name: S3 Browser

S3 Browser is a freeware Windows client for Amazon S3 and Amazon CloudFront. Amazon S3 provides a simple web services interface that can be used to store and retrieve any amount of data, at any time, from anywhere on the web. Amazon CloudFront is a content delivery network (CDN). It can be used to deliver your files using a global network of edge locations.


If it's only single time then you can use the command line to perform these operations:

(1) Rename the folder in the same bucket:

s3cmd --access_key={access_key} --secret_key={secret_key} mv s3://bucket/folder1/* s3://bucket/folder2/

(2) Rename the Bucket:

s3cmd --access_key={access_key} --secret_key={secret_key} mv s3://bucket1/folder/* s3://bucket2/folder/

Where,

{access_key} = Your valid access key for s3 client

{secret_key} = Your valid scret key for s3 client

It's working fine without any problem.

Thanks

How can I disable a tab inside a TabControl?

I could not find an appropriate answer to the question. There looks to be no solution to disable the specific tab. What I did is to pass the specific tab to a variable and in SelectedIndexChanged event put it back to SelectedIndex:

//variable for your specific tab 
int _TAB = 0;

//here you specify your tab that you want to expose
_TAB = 1;
tabHolder.SelectedIndex = _TAB;

private void tabHolder_SelectedIndexChanged(object sender, EventArgs e)
{
    if (_TAB != 0) tabHolder.SelectedIndex = _TAB;
}

So, you don't actually disable the tab, but when another tab is clicked it always returns you to the selected tab.

Call a VBA Function into a Sub Procedure

Here are some of the different ways you can call things in Microsoft Access:

To call a form sub or function from a module

The sub in the form you are calling MUST be public, as in:

Public Sub DoSomething()
  MsgBox "Foo"
End Sub

Call the sub like this:

Call Forms("form1").DoSomething

The form must be open before you make the call.

To call an event procedure, you should call a public procedure within the form, and call the event procedure within this public procedure.

To call a subroutine in a module from a form

Public Sub DoSomethingElse()
  MsgBox "Bar"
End Sub

...just call it directly from your event procedure:

Call DoSomethingElse

To call a subroutine from a form without using an event procedure

If you want, you can actually bind the function to the form control's event without having to create an event procedure under the control. To do this, you first need a public function in the module instead of a sub, like this:

Public Function DoSomethingElse()
  MsgBox "Bar"
End Function

Then, if you have a button on the form, instead of putting [Event Procedure] in the OnClick event of the property window, put this:

=DoSomethingElse()

When you click the button, it will call the public function in the module.

To call a function instead of a procedure

If calling a sub looks like this:

Call MySub(MyParameter)

Then calling a function looks like this:

Result=MyFunction(MyFarameter)

where Result is a variable of type returned by the function.

NOTE: You don't always need the Call keyword. Most of the time, you can just call the sub like this:

MySub(MyParameter)

Execute a batch file on a remote PC using a batch file on local PC

While I would recommend against this.

But you can use shutdown as client if the target machine has remote shutdown enabled and is in the same workgroup.

Example:

shutdown.exe /s /m \\<target-computer-name> /t 00

replacing <target-computer-name> with the URI for the target machine,

Otherwise, if you want to trigger this through Apache, you'll need to configure the batch script as a CGI script by putting AddHandler cgi-script .bat and Options +ExecCGI into either a local .htaccess file or in the main configuration for your Apache install.

Then you can just call the .bat file containing the shutdown.exe command from your browser.

Subtract minute from DateTime in SQL Server 2005

Have you tried

SELECT DATEADD(mi, -15,'2000-01-01 08:30:00')

DATEDIFF is the difference between 2 dates.

PHP - Check if the page run on Mobile or Desktop browser

You can do it manually if you want.

Reference: http://php.net/manual/en/function.get-browser.php

preg_match('/windows|win32/i', $_SERVER['HTTP_USER_AGENT'])

preg_match('/iPhone|iPod|iPad/', $_SERVER['HTTP_USER_AGENT'])

You can even make it a script

$device = 'Blackberry'

preg_match("/$device/", $_SERVER['HTTP_USER_AGENT'])

Here is somewhat of a small list

                        '/windows nt 6.2/i'     =>  'Windows 8',
                        '/windows nt 6.1/i'     =>  'Windows 7',
                        '/windows nt 6.0/i'     =>  'Windows Vista',
                        '/windows nt 5.2/i'     =>  'Windows Server 2003/XP x64',
                        '/windows nt 5.1/i'     =>  'Windows XP',
                        '/windows xp/i'         =>  'Windows XP',
                        '/windows nt 5.0/i'     =>  'Windows 2000',
                        '/windows me/i'         =>  'Windows ME',
                        '/win98/i'              =>  'Windows 98',
                        '/win95/i'              =>  'Windows 95',
                        '/win16/i'              =>  'Windows 3.11',
                        '/macintosh|mac os x/i' =>  'Mac OS X',
                        '/mac_powerpc/i'        =>  'Mac OS 9',
                        '/linux/i'              =>  'Linux',
                        '/ubuntu/i'             =>  'Ubuntu',
                        '/iphone/i'             =>  'iPhone',
                        '/ipod/i'               =>  'iPod',
                        '/ipad/i'               =>  'iPad',
                        '/android/i'            =>  'Android',
                        '/blackberry/i'         =>  'BlackBerry',
                        '/webos/i'              =>  'Mobile'

Browsers

                        '/msie/i'       =>  'Internet Explorer',
                        '/firefox/i'    =>  'Firefox',
                        '/safari/i'     =>  'Safari',
                        '/chrome/i'     =>  'Chrome',
                        '/opera/i'      =>  'Opera',
                        '/netscape/i'   =>  'Netscape',
                        '/maxthon/i'    =>  'Maxthon',
                        '/konqueror/i'  =>  'Konqueror',
                        '/mobile/i'     =>  'Handheld Browser'

C++11 introduced a standardized memory model. What does it mean? And how is it going to affect C++ programming?

This is now a multiple-year old question, but being very popular, it's worth mentioning a fantastic resource for learning about the C++11 memory model. I see no point in summing up his talk in order to make this yet another full answer, but given this is the guy who actually wrote the standard, I think it's well worth watching the talk.

Herb Sutter has a three hour long talk about the C++11 memory model titled "atomic<> Weapons", available on the Channel9 site - part 1 and part 2. The talk is pretty technical, and covers the following topics:

  1. Optimizations, Races, and the Memory Model
  2. Ordering – What: Acquire and Release
  3. Ordering – How: Mutexes, Atomics, and/or Fences
  4. Other Restrictions on Compilers and Hardware
  5. Code Gen & Performance: x86/x64, IA64, POWER, ARM
  6. Relaxed Atomics

The talk doesn't elaborate on the API, but rather on the reasoning, background, under the hood and behind the scenes (did you know relaxed semantics were added to the standard only because POWER and ARM do not support synchronized load efficiently?).

Multiple input in JOptionPane.showInputDialog

this is my solution

JTextField username = new JTextField();
JTextField password = new JPasswordField();
Object[] message = {
    "Username:", username,
    "Password:", password
};

int option = JOptionPane.showConfirmDialog(null, message, "Login", JOptionPane.OK_CANCEL_OPTION);
if (option == JOptionPane.OK_OPTION) {
    if (username.getText().equals("h") && password.getText().equals("h")) {
        System.out.println("Login successful");
    } else {
        System.out.println("login failed");
    }
} else {
    System.out.println("Login canceled");
}

Submitting form and pass data to controller method of type FileStreamResult

When in doubt, follow MVC conventions.

Create a viewModel if you haven't already that contains a property for JobID

public class Model
{
     public string JobId {get; set;}
     public IEnumerable<MyCurrentModel> myCurrentModel { get; set; }
     //...any other properties you may need
}

Strongly type your view

@model Fully.Qualified.Path.To.Model

Add a hidden field for JobId to the form

using (@Html.BeginForm("myMethod", "Home", FormMethod.Post))
{   
    //...    
    @Html.HiddenFor(m => m.JobId)
}

And accept the model as the parameter in your controller action:

[HttpPost]
public FileStreamResult myMethod(Model model)
{
    sting str = model.JobId;
}

How to add to the end of lines containing a pattern with sed or awk?

Solution with awk:

awk '{if ($1 ~ /^all/) print $0, "anotherthing"; else print $0}' file

Simply: if the row starts with all print the row plus "anotherthing", else print just the row.

Change HTML email body font type and size in VBA

I did a little research and was able to write this code:

strbody = "<BODY style=font-size:11pt;font-family:Calibri>Good Morning;<p>We have completed our main aliasing process for today.  All assigned firms are complete.  Please feel free to respond with any questions.<p>Thank you.</BODY>"

apparently by setting the "font-size=11pt" instead of setting the font size <font size=5>, It allows you to select a specific font size like you normally would in a text editor, as opposed to selecting a value from 1-7 like my code was originally.

This link from simpLE MAn gave me some good info.

How to set default values in Go structs

From https://golang.org/doc/effective_go.html#composite_literals:

Sometimes the zero value isn't good enough and an initializing constructor is necessary, as in this example derived from package os.

    func NewFile(fd int, name string) *File {
      if fd < 0 {
        return nil
      }
      f := new(File)
      f.fd = fd
      f.name = name
      f.dirinfo = nil
      f.nepipe = 0
      return f
}

Format in kotlin string templates

Unfortunately, there's no built-in support for formatting in string templates yet, as a workaround, you can use something like:

"pi = ${pi.format(2)}"

the .format(n) function you'd need to define yourself as

fun Double.format(digits: Int) = "%.${digits}f".format(this)

There's clearly a piece of functionality here that is missing from Kotlin at the moment, we'll fix it.

How can I get the full object in Node.js's console.log(), rather than '[Object]'?

perhaps console.dir is all you need.

http://nodejs.org/api/console.html#console_console_dir_obj

Uses util.inspect on obj and prints resulting string to stdout.

use util option if you need more control.

Postman Chrome: What is the difference between form-data, x-www-form-urlencoded and raw

multipart/form-data

Note. Please consult RFC2388 for additional information about file uploads, including backwards compatibility issues, the relationship between "multipart/form-data" and other content types, performance issues, etc.

Please consult the appendix for information about security issues for forms.

The content type "application/x-www-form-urlencoded" is inefficient for sending large quantities of binary data or text containing non-ASCII characters. The content type "multipart/form-data" should be used for submitting forms that contain files, non-ASCII data, and binary data.

The content type "multipart/form-data" follows the rules of all multipart MIME data streams as outlined in RFC2045. The definition of "multipart/form-data" is available at the [IANA] registry.

A "multipart/form-data" message contains a series of parts, each representing a successful control. The parts are sent to the processing agent in the same order the corresponding controls appear in the document stream. Part boundaries should not occur in any of the data; how this is done lies outside the scope of this specification.

As with all multipart MIME types, each part has an optional "Content-Type" header that defaults to "text/plain". User agents should supply the "Content-Type" header, accompanied by a "charset" parameter.

application/x-www-form-urlencoded

This is the default content type. Forms submitted with this content type must be encoded as follows:

Control names and values are escaped. Space characters are replaced by +', and then reserved characters are escaped as described in [RFC1738], section 2.2: Non-alphanumeric characters are replaced by%HH', a percent sign and two hexadecimal digits representing the ASCII code of the character. Line breaks are represented as "CR LF" pairs (i.e., %0D%0A'). The control names/values are listed in the order they appear in the document. The name is separated from the value by=' and name/value pairs are separated from each other by `&'.

application/x-www-form-urlencoded the body of the HTTP message sent to the server is essentially one giant query string -- name/value pairs are separated by the ampersand (&), and names are separated from values by the equals symbol (=). An example of this would be:

MyVariableOne=ValueOne&MyVariableTwo=ValueTwo

The content type "application/x-www-form-urlencoded" is inefficient for sending large quantities of binary data or text containing non-ASCII characters. The content type "multipart/form-data" should be used for submitting forms that contain files, non-ASCII data, and binary data.

Filter spark DataFrame on string contains

In pyspark,SparkSql syntax:

where column_n like 'xyz%'

might not work.

Use:

where column_n RLIKE '^xyz' 

This works perfectly fine.

bootstrap initially collapsed element

I just added class hide to the div before "card-body" and it hidden by default.

<div id="collapseOne" class="collapse hide" aria-labelledby="headingOne" data-parent="#accordion">

Why .NET String is immutable?

Just to throw this in, an often forgotten view is of security, picture this scenario if strings were mutable:

string dir = "C:\SomePlainFolder";

//Kick off another thread
GetDirectoryContents(dir);

void GetDirectoryContents(string directory)
{
  if(HasAccess(directory) {
    //Here the other thread changed the string to "C:\AllYourPasswords\"
    return Contents(directory);
  }
  return null;
}

You see how it could be very, very bad if you were allowed to mutate strings once they were passed.

Javascript how to parse JSON array

Not sure if my data matched exactly but I had an array of arrays of JSON objects, that got exported from jQuery FormBuilder when using pages.

Hopefully my answer can help anyone who stumbles onto this question looking for an answer to a problem similar to what I had.

The data looked somewhat like this:

var allData = 
[
    [
        {
            "type":"text",
            "label":"Text Field"
        }, 
        {
            "type":"text",
            "label":"Text Field"
        }
    ],
    [
        {
            "type":"text",
            "label":"Text Field"
        }, 
        {
            "type":"text",
            "label":"Text Field"
        }
    ]
]

What I did to parse this was to simply do the following:

JSON.parse("["+allData.toString()+"]")

PHP call Class method / function

You need to create Object for the class.

$obj = new Functions();
$var = $obj->filter($_GET['params']);

MySQL - How to parse a string value to DATETIME format inside an INSERT statement?

Use MySQL's STR_TO_DATE() function to parse the string that you're attempting to insert:

INSERT INTO tblInquiry (fldInquiryReceivedDateTime) VALUES
  (STR_TO_DATE('5/15/2012 8:06:26 AM', '%c/%e/%Y %r'))

“Unable to find manifest signing certificate in the certificate store” - even when add new key

Go to your project's "Properties" within visual studio. Then go to signing tab.

Then make sure Sign the Click Once manifests is turned off.


Updated Instructions:

Within your Solution Explorer:

  1. right click on your project
  2. click on properties
  3. usually on the left-hand side, select the "Signing" tab
  4. check off the Sign the ClickOnce manifests
  5. Make sure you save!

enter image description here

How to replace ${} placeholders in a text file?

template.txt

Variable 1 value: ${var1}
Variable 2 value: ${var2}

data.sh

#!/usr/bin/env bash
declare var1="value 1"
declare var2="value 2"

parser.sh

#!/usr/bin/env bash

# args
declare file_data=$1
declare file_input=$2
declare file_output=$3

source $file_data
eval "echo \"$(< $file_input)\"" > $file_output

./parser.sh data.sh template.txt parsed_file.txt

parsed_file.txt

Variable 1 value: value 1
Variable 2 value: value 2

JSON date to Java date?

That DateTime format is actually ISO 8601 DateTime. JSON does not specify any particular format for dates/times. If you Google a bit, you will find plenty of implementations to parse it in Java.

Here's one

If you are open to using something other than Java's built-in Date/Time/Calendar classes, I would also suggest Joda Time. They offer (among many things) a ISODateTimeFormat to parse these kinds of strings.

How can Bash execute a command in a different directory context?

(cd /path/to/your/special/place;/bin/your-special-command ARGS)

jQuery 1.9 .live() is not a function

The jQuery API documentation lists live() as deprecated as of version 1.7 and removed as of version 1.9: link.

version deprecated: 1.7, removed: 1.9

Furthermore it states:

As of jQuery 1.7, the .live() method is deprecated. Use .on() to attach event handlers. Users of older versions of jQuery should use .delegate() in preference to .live()

SQL Server Convert Varchar to Datetime

You could do it this way but it leaves it as a varchar

declare @s varchar(50)

set @s = '2011-09-28 18:01:00'

select convert(varchar, cast(@s as datetime), 105) + RIGHT(@s, 9)

or

select convert(varchar(20), @s, 105)

CSS align images and text on same line

You can simply center the image and text in the parent tag by setting

div {
     text-align: center;
}

vertical center the img and span

img {
     vertical-align:middle;
}
span {
     vertical-align:middle;
}

You can just add second set below, and one thing to mention is that h4 has block display attribute, so you might want to set

h4 {
    display: inline-block
}

to set the h4 "inline".

The full example is shown here.

_x000D_
_x000D_
<div id="photo" style="text-align: center">_x000D_
  <img style="vertical-align:middle" src="https://via.placeholder.com/22x22" alt="">_x000D_
  <span style="vertical-align:middle">Take a photo</span>_x000D_
</div>
_x000D_
_x000D_
_x000D_

CSS hexadecimal RGBA?

Charming Prince:

Only internet explorer allows the 4 byte hex color in the format of ARGB, where A is the Alpha channel. It can be used in gradient filters for example:

filter  : ~"progid:DXImageTransform.Microsoft.Gradient(GradientType=@{dir},startColorstr=@{color1},endColorstr=@{color2})";

Where dir can be: 1(horizontal) or 0(vertical) And the color strings can be hex colors(#FFAAD3) or argb hex colors(#88FFAAD3).

Creating and Update Laravel Eloquent

Here's a full example of what "lu cip" was talking about:

$user = User::firstOrNew(array('name' => Input::get('name')));
$user->foo = Input::get('foo');
$user->save();

Below is the updated link of the docs which is on the latest version of Laravel

Docs here: Updated link

How to remove outliers in boxplot in R?

See ?boxplot for all the help you need.

 outline: if ‘outline’ is not true, the outliers are not drawn (as
          points whereas S+ uses lines).

boxplot(x,horizontal=TRUE,axes=FALSE,outline=FALSE)

And for extending the range of the whiskers and suppressing the outliers inside this range:

   range: this determines how far the plot whiskers extend out from the
          box.  If ‘range’ is positive, the whiskers extend to the most
          extreme data point which is no more than ‘range’ times the
          interquartile range from the box. A value of zero causes the
          whiskers to extend to the data extremes.

# change the value of range to change the whisker length
boxplot(x,horizontal=TRUE,axes=FALSE,range=2)

How do I get PHP errors to display?

Use:

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

This is the best way to write it, but a syntax error gives blank output, so use the console to check for syntax errors. The best way to debug PHP code is to use the console; run the following:

php -l phpfilename.php

PHP how to get value from array if key is in a variable

$value = ( array_key_exists($key, $array) && !empty($array[$key]) ) 
         ? $array[$key] 
         : 'non-existant or empty value key';