Programs & Examples On #Wingdings

Tick symbol in HTML/XHTML

although sets browser encoding to UTF-8

(If you're using numeric character references of course it doesn't matter what encoding is being used, browsers will get the correct Unicode codepoint directly from the number.)

<span style="font-family: wingdings; font-size: 200%;">&#252;</span>

I would appreciate if someone could check under FF on Windows. I am pretty sure it won't work on a non Windows box.

Fails for me in Firefox 3, Opera, and Safari. Curiously, works in the other Webkit browser, Chrome. Also fails on Linux (obviously, as Wingdings isn't installed there; it is installed on Macs, but that doesn't help you if Safari's not having it).

Also it's a pretty nasty hack — that character is to all intents and purposes “ü” and will appear that way to things like search engines, or if the text is copy-and-pasted. Proper Unicode code points are the way to go unless you really have no alternative.

The problem is that no font bundled with Windows supplies U+2713 CHECK MARK (‘?’). The only one that you're at all likely to find on a Windows machine is “Arial Unicode MS”, which is not really to be relied upon. So in the end I think you'll have to either:

  • use a different character which is better supported (eg. ‘?’ — bullet, as used by SO), or
  • use an image, with ‘?’ as the alt text.

Check if my SSL Certificate is SHA1 or SHA2

openssl s_client -connect api.cscglobal.com:443 < /dev/null 2>/dev/null  | openssl x509 -text -in /dev/stdin | grep "Signature Algorithm" | cut -d ":" -f2 | uniq | sed '/^$/d' | sed -e 's/^[ \t]*//'

How to get file extension from string in C++

This is a solution I came up with. Then, I noticed that it is similar to what @serengeor posted.

It works with std::string and find_last_of, but the basic idea will also work if modified to use char arrays and strrchr. It handles hidden files, and extra dots representing the current directory. It is platform independent.

string PathGetExtension( string const & path )
{
  string ext;

  // Find the last dot, if any.
  size_t dotIdx = path.find_last_of( "." );
  if ( dotIdx != string::npos )
  {
    // Find the last directory separator, if any.
    size_t dirSepIdx = path.find_last_of( "/\\" );

    // If the dot is at the beginning of the file name, do not treat it as a file extension.
    // e.g., a hidden file:  ".alpha".
    // This test also incidentally avoids a dot that is really a current directory indicator.
    // e.g.:  "alpha/./bravo"
    if ( dotIdx > dirSepIdx + 1 )
    {
      ext = path.substr( dotIdx );
    }
  }

  return ext;
}

Unit test:

int TestPathGetExtension( void )
{
  int errCount = 0;

  string tests[][2] = 
  {
    { "/alpha/bravo.txt", ".txt" },
    { "/alpha/.bravo", "" },
    { ".alpha", "" },
    { "./alpha.txt", ".txt" },
    { "alpha/./bravo", "" },
    { "alpha/./bravo.txt", ".txt" },
    { "./alpha", "" },
    { "c:\\alpha\\bravo.net\\charlie.txt", ".txt" },
  };

  int n = sizeof( tests ) / sizeof( tests[0] );

  for ( int i = 0; i < n; ++i )
  {
    string ext = PathGetExtension( tests[i][0] );
    if ( ext != tests[i][1] )
    {
      ++errCount;
    }
  }

  return errCount;
}

What is the fastest way to create a checksum for large files in C#

As Anton Gogolev noted, FileStream reads 4096 bytes at a time by default, But you can specify any other value using the FileStream constructor:

new FileStream(file, FileMode.Open, FileAccess.Read, FileShare.ReadWrite, 16 * 1024 * 1024)

Note that Brad Abrams from Microsoft wrote in 2004:

there is zero benefit from wrapping a BufferedStream around a FileStream. We copied BufferedStream’s buffering logic into FileStream about 4 years ago to encourage better default performance

source

How do I write a "tab" in Python?

This is the code:

f = open(filename, 'w')
f.write("hello\talex")

The \t inside the string is the escape sequence for the horizontal tabulation.

Write bytes to file

Try this:

private byte[] Hex2Bin(string hex) 
{
 if ((hex == null) || (hex.Length < 1)) {
  return new byte[0];
 }
 int num = hex.Length / 2;
 byte[] buffer = new byte[num];
 num *= 2;
 for (int i = 0; i < num; i++) {
  int num3 = int.Parse(hex.Substring(i, 2), NumberStyles.HexNumber);
  buffer[i / 2] = (byte) num3;
  i++;
 }
 return buffer;
}

private string Bin2Hex(byte[] binary) 
{
 StringBuilder builder = new StringBuilder();
 foreach(byte num in binary) {
  if (num > 15) {
   builder.AppendFormat("{0:X}", num);
  } else {
   builder.AppendFormat("0{0:X}", num); /////// ?? 15 ???? 0
  }
 }
 return builder.ToString();
}

C++ getters/setters coding style

Using a getter method is a better design choice for a long-lived class as it allows you to replace the getter method with something more complicated in the future. Although this seems less likely to be needed for a const value, the cost is low and the possible benefits are large.

As an aside, in C++, it's an especially good idea to give both the getter and setter for a member the same name, since in the future you can then actually change the the pair of methods:

class Foo {
public:
    std::string const& name() const;          // Getter
    void name(std::string const& newName);    // Setter
    ...
};

Into a single, public member variable that defines an operator()() for each:

// This class encapsulates a fancier type of name
class fancy_name {
public:
    // Getter
    std::string const& operator()() const {
        return _compute_fancy_name();    // Does some internal work
    }

    // Setter
    void operator()(std::string const& newName) {
        _set_fancy_name(newName);        // Does some internal work
    }
    ...
};

class Foo {
public:
    fancy_name name;
    ...
};

The client code will need to be recompiled of course, but no syntax changes are required! Obviously, this transformation works just as well for const values, in which only a getter is needed.

Import Android volley to Android Studio

So Volley has been updated to Android studio build style which makes it harder create a jar. But the recommended way for eclipse was using it as a library project and this goes for android studio as well, but when working in android studio we call this a module. So here is a guide to how do it the way Google wants us to do it. Guide is based on this nice tutorial.

  1. First get latest volley with git (git clone https://android.googlesource.com/platform/frameworks/volley).

  2. In your current project (android studio) click [File] --> [New] -->[Import Module].

  3. Now select the directory where you downloaded Volley to.

  4. Now Android studio might guide you to do the rest but continue guide to verify that everything works correct

  5. Open settings.gradle (find in root) and add (or verify this is included):

    include ':app', ':volley'

  6. Now go to your build.gradle in your project and add the dependency:

    compile project(":volley")

Thats all there is to it, much simpler and easier than compiling a jar and safer than relying on third parties jars or maven uploads.

How to create .ipa file using Xcode?

In addition to kus answer.

There are some changes in Xcode 8.0

Step 1: Change scheme destination to Generic IOS device.

Step 2: Click Product > Archive > once this is complete open up the Organiser and click the latest version.

Step 3: Click on Export... option from right side of organiser window.

Step 4: Select a method for export > Choose correct signing > Save to Destination.


Xcode 10.0

Step 3: From Right Side Panel Click on Distribute App.

Step 4: Select Method of distribution and click next.

Step 5: It Opens up distribution option window. Select All compatible device variants and click next.

Step 6: Choose signing certificate.

Step 7: It will open up Preparing archive for distribution window. it takes few min.

Step 8: It will open up Archives window. Click on export and save it.


Determine .NET Framework version for dll

Use ILSpy http://ilspy.net/

open source, free, definitely an option since now reflector is paid.

OrderBy pipe issue

Component template:
todos| sort: ‘property’:’asc|desc’

Pipe code:

import { Pipe,PipeTransform  } from "angular/core";
import {Todo} from './todo';

@Pipe({
  name: "sort"
})
export class TodosSortPipe implements PipeTransform {
  transform(array: Array<Todo>, args: string): Array<Todo> {
    array.sort((a: any, b: any) => {
      if (a < b) {
        return -1;
      } else if (a > b) {
        return 1;
      } else {`enter code here`
        return 0;
      }
    });
    return array;
  }
}

How to print variable addresses in C?

You want to use %p to print a pointer. From the spec:

p The argument shall be a pointer to void. The value of the pointer is converted to a sequence of printing characters, in an implementation-defined manner.

And don't forget the cast, e.g.

printf("%p\n",(void*)&a);

How to extract the hostname portion of a URL in JavaScript

Use document.location object and its host or hostname properties.

alert(document.location.hostname); // alerts "stackoverflow.com"

Is there a way to specify a max height or width for an image?

You can try this one

img{
    max-height:500px;
    max-width:500px;
    height:auto;
    width:auto;
}

This keeps the aspect ratio of the image and prevents either the two dimensions exceed 500px

You can check this post

Starting a shell in the Docker Alpine container

ole@T:~$ docker run -it --rm alpine /bin/ash
(inside container) / # 

Options used above:

  • /bin/ash is Ash (Almquist Shell) provided by BusyBox
  • --rm Automatically remove the container when it exits (docker run --help)
  • -i Interactive mode (Keep STDIN open even if not attached)
  • -t Allocate a pseudo-TTY

libxml/tree.h no such file or directory

Form the link of @Matt Ball,

I found following helpful to me.

You need to add libxml2.dylib to your project (don't put it in the Frameworks section). On the Mac, you'll find it at /usr/lib/libxml2.dylib and for the iPhone, you'll want the /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS2.0.sdk/usr/lib/libxml2.dylib version.

Since libxml2 is a .dylib (not a nice friendly .framework) we still have one more thing to do. Go to the Project build settings (Project->Edit Project Settings->Build) and find the "Search Paths". In "Header Search Paths" add the following path on the Mac:

 /usr/include/libxml2 

Remove spaces from a string in VB.NET

This will remove spaces only, matches the SQL functionality of rtrim(ltrim(myString))

Dim charstotrim() As Char = {" "c}
myString = myString .Trim(charstotrim) 

Facebook share link without JavaScript

In case you want to share on more forums, here is the solution.. https://github.com/bradvin/social-share-urls

Android Studio with Google Play Services

All those answers are wrong, since the release of gradle plugin v0.4.2 the setup of google play services under android studio is straight forward. You don't need to import any jar or add any project library nor add any new module under android studio. What you have to do is to add the correct dependencies into the build.gradle file. Please take a look to those links: Gradle plugin v0.4.2 update, New Build System, and this sample

The Correct way to do so is as follows:

First of all you have to launch the sdk manager and download and install the following files located under "extras": Android support repository, Google play services, Google repository.

Restart android studio and open the build gradle file. You must modify your build.gradle file to look like this under dependencies:

dependencies {
    compile 'com.google.android.gms:play-services:6.5.87' 
 }

And finally syncronise your project (the button to the left of the AVD manager).

Since version 6.5 you can include the complete library (very large) or just the modules that you need (Best Option). I.e if you only need Google Maps and Analytics you can replace the previous example with the following one:

dependencies {  
    compile 'com.google.android.gms:play-services-base:6.5.87'    
    compile 'com.google.android.gms:play-services-maps:6.5.87'  
}

You can find the complete dependency list here

Some side notes:

  • Use the latest play services library version. If it's an old version, android studio will highlight it. As of today (February 5th is 6.5.87) but you can check the latest version at Gradle Please
  • After a major update of Android Studio, clean an rebuild your project by following the next instructions as suggested in the comments by @user123321

    cd to your project folder
    ./gradlew clean
    ./gradlew build

Angular: Cannot find a differ supporting object '[object Object]'

Explanation: You can *ngFor on the arrays. You have your users declared as the array. But, the response from the Get returns you an object. You cannot ngFor on the object. You should have an array for that. You can explicitly cast the object to array and that will solve the issue. data to [data]

Solution

getusers() {
    this.http.get(`https://api.github.com/
search/users?q=${this.input1.value}`)
        .map(response => response.json())
        .subscribe(
        data => this.users = [data], //Cast your object to array. that will do it.
        error => console.log(error)
        )

MAX() and MAX() OVER PARTITION BY produces error 3504 in Teradata Query

Logically OLAP functions are calculated after GROUP BY/HAVING, so you can only access columns in GROUP BY or columns with an aggregate function. Following looks strange, but is Standard SQL:

SELECT employee_number,
       MAX(MAX(course_completion_date)) 
           OVER (PARTITION BY course_code) AS max_course_date,
       MAX(course_completion_date) AS max_date
FROM employee_course_completion
WHERE course_code IN ('M910303', 'M91301R', 'M91301P')
GROUP BY employee_number, course_code

And as Teradata allows re-using an alias this also works:

SELECT employee_number,
       MAX(max_date) 
           OVER (PARTITION BY course_code) AS max_course_date,
       MAX(course_completion_date) AS max_date
FROM employee_course_completion
WHERE course_code IN ('M910303', 'M91301R', 'M91301P')
GROUP BY employee_number, course_code

PostgreSQL create table if not exists

There is no CREATE TABLE IF NOT EXISTS... but you can write a simple procedure for that, something like:

CREATE OR REPLACE FUNCTION execute(TEXT) RETURNS VOID AS $$
BEGIN
  EXECUTE $1;
END; $$ LANGUAGE plpgsql;


SELECT 
  execute($$
      CREATE TABLE sch.foo 
      (
        i integer
      )
  $$) 
WHERE 
  NOT exists 
  (
    SELECT * 
    FROM information_schema.tables 
    WHERE table_name = 'foo'
      AND table_schema = 'sch'
  );

How to Display Multiple Google Maps per page with API V3

Take a Look at this Bundle for Laravel that I Made Recently !


https://github.com/Maghrooni/googlemap

it helps you to create one or multiple maps in your page !

you can find the class on

src/googlemap.php

Pls Read the readme file first and don't forget to pass different ID if you want to have multiple Maps in one page

indexOf Case Sensitive?

The first question has already been answered many times. Yes, the String.indexOf() methods are all case-sensitive.

If you need a locale-sensitive indexOf() you could use the Collator. Depending on the strength value you set you can get case insensitive comparison, and also treat accented letters as the same as the non-accented ones, etc. Here is an example of how to do this:

private int indexOf(String original, String search) {
    Collator collator = Collator.getInstance();
    collator.setStrength(Collator.PRIMARY);
    for (int i = 0; i <= original.length() - search.length(); i++) {
        if (collator.equals(search, original.substring(i, i + search.length()))) {
            return i;
        }
    }
    return -1;
}

jwt check if token expired

This is for react-native, but login will work for all types.

isTokenExpired = async () => {
    try {
        const LoginTokenValue = await AsyncStorage.getItem('LoginTokenValue');
        if (JSON.parse(LoginTokenValue).RememberMe) {
            const { exp } = JwtDecode(LoginTokenValue);
            if (exp < (new Date().getTime() + 1) / 1000) {
                this.handleSetTimeout();
                return false;
            } else {
                //Navigate inside the application
                return true;
            }
        } else {
            //Navigate to the login page
        }
    } catch (err) {
        console.log('Spalsh -> isTokenExpired -> err', err);
        //Navigate to the login page
        return false;
    }
}

including parameters in OPENQUERY

Simple example based off of @Tuan Zaidi's example above which seemed the easiest. Didn't know you can do the filter on the outside of OPENQUERY... so much easier!

However in my case I needed to stuff it in a variable so I created an additional Sub Query Level to return a single value.

SET @SFID = (SELECT T.Id FROM (SELECT Id,  Contact_ID_SQL__c  FROM OPENQUERY([TR-SF-PROD], 'SELECT Id,  Contact_ID_SQL__c FROM Contact') WHERE Contact_ID_SQL__c = @ContactID) T)

Jquery UI datepicker. Disable array of Dates

For DD-MM-YY use this code:

var array = ["03-03-2017', '03-10-2017', '03-25-2017"]

$('#datepicker').datepicker({
    beforeShowDay: function(date){
    var string = jQuery.datepicker.formatDate('dd-mm-yy', date);
    return [ array.indexOf(string) == -1 ]
    }
});

function highlightDays(date) {
    for (var i = 0; i < dates.length; i++) {
    if (new Date(dates[i]).toString() == date.toString()) {
        return [true, 'highlight'];
    }
}
return [true, ''];
}

Java: How to insert CLOB into oracle database

passing the xml content as string.

table1 

ID   int
XML  CLOB



import oracle.jdbc.OraclePreparedStatement;
/*
Your Code
*/
 void insert(int id, String xml){
    try {
        String sql = "INSERT INTO table1(ID,XML) VALUES ("
                + id
                + "', ? )";
        PreparedStatement ps = conn.prepareStatement(sql);
        ((OraclePreparedStatement) ps).setStringForClob(1, xml);
        ps.execute();
        result = true;
        } catch (Exception e) {
        e.printStackTrace();
    }
  }

Eclipse/Maven error: "No compiler is provided in this environment"

Screen_shot Add 'tools.jar' to installed JRE.

  1. Eclipse -> window -> preference.
  2. Select installed JREs -> Edit
  3. Add External Jars
  4. select tools.jar from java/JDKx.x/lib folder.
  5. Click Finish

C++ error : terminate called after throwing an instance of 'std::bad_alloc'

The problem in your code is that you can't store the memory address of a local variable (local to a function, for example) in a globlar variable:

RectInvoice rect(vect,im,x, y, w ,h);
this->rectInvoiceVector.push_back(&rect);

There, &rect is a temporary address (stored in the function's activation registry) and will be destroyed when that function end.

The code should create a dynamic variable:

RectInvoice *rect =  new RectInvoice(vect,im,x, y, w ,h);
this->rectInvoiceVector.push_back(rect);

There you are using a heap address that will not be destroyed in the end of the function's execution. Tell me if it worked for you.

Cheers

Full path from file input using jQuery

You can't: It's a security feature in all modern browsers.

For IE8, it's off by default, but can be reactivated using a security setting:

When a file is selected by using the input type=file object, the value of the value property depends on the value of the "Include local directory path when uploading files to a server" security setting for the security zone used to display the Web page containing the input object.

The fully qualified filename of the selected file is returned only when this setting is enabled. When the setting is disabled, Internet Explorer 8 replaces the local drive and directory path with the string C:\fakepath\ in order to prevent inappropriate information disclosure.

In all other current mainstream browsers I know of, it is also turned off. The file name is the best you can get.

More detailed info and good links in this question. It refers to getting the value server-side, but the issue is the same in JavaScript before the form's submission.

convert iso date to milliseconds in javascript

Yes, you can do this in a single line

let ms = Date.parse('2019-05-15 07:11:10.673Z');
console.log(ms);//1557904270673

How to escape braces (curly brackets) in a format string in .NET

My objective:

I needed to assign the value "{CR}{LF}" to a string variable delimiter.

Code c#:

string delimiter= "{{CR}}{{LF}}";

Note: To escape special characters normally you have to use . For opening curly bracket {, use one extra like {{. For closing curly bracket }, use one extra }}.

PYODBC--Data source name not found and no default driver specified

I'm using

Django 2.2

and got the same error while connecting to sql-server 2012. Spent lot of time to solve this issue and finally this worked.

I changed

'driver': 'ODBC Driver 13 for SQL Server'

to

'driver': 'SQL Server Native Client 11.0'

and it worked.

Paste in insert mode?

Just add map:

" ~/.vimrc
inoremap <c-p> <c-r>*

restart vim and when press Crtl+p in insert mode, copied text will be pasted

Error 80040154 (Class not registered exception) when initializing VCProjectEngineObject (Microsoft.VisualStudio.VCProjectEngine.dll)

There are not many good reasons this would fail, especially the regsvr32 step. Run dumpbin /exports on that dll. If you don't see DllRegisterServer then you've got a corrupt install. It should have more side-effects, you wouldn't be able to build C/C++ projects anymore.

One standard failure mode is running this on a 64-bit operating system. This is 32-bit unmanaged code, you would indeed get the 'class not registered' exception. Project + Properties, Build tab, change Platform Target to x86.

seek() function?

When you open a file, the system points to the beginning of the file. Any read or write you do will happen from the beginning. A seek() operation moves that pointer to some other part of the file so you can read or write at that place.

So, if you want to read the whole file but skip the first 20 bytes, open the file, seek(20) to move to where you want to start reading, then continue with reading the file.

Or say you want to read every 10th byte, you could write a loop that does seek(9, 1) (moves 9 bytes forward relative to the current positions), read(1) (reads one byte), repeat.

Remove all occurrences of a value from a list?

No one has posted an optimal answer for time and space complexity, so I thought I would give it a shot. Here is a solution that removes all occurrences of a specific value without creating a new array and at an efficient time complexity. The drawback is that the elements do not maintain order.

Time complexity: O(n)
Additional space complexity: O(1)

def main():
    test_case([1, 2, 3, 4, 2, 2, 3], 2)     # [1, 3, 3, 4]
    test_case([3, 3, 3], 3)                 # []
    test_case([1, 1, 1], 3)                 # [1, 1, 1]


def test_case(test_val, remove_val):
    remove_element_in_place(test_val, remove_val)
    print(test_val)


def remove_element_in_place(my_list, remove_value):
    length_my_list = len(my_list)
    swap_idx = length_my_list - 1

    for idx in range(length_my_list - 1, -1, -1):
        if my_list[idx] == remove_value:
            my_list[idx], my_list[swap_idx] = my_list[swap_idx], my_list[idx]
            swap_idx -= 1

    for pop_idx in range(length_my_list - swap_idx - 1):
        my_list.pop() # O(1) operation


if __name__ == '__main__':
    main()

Get the last item in an array

The "cleanest" ES6 way (IMO) would be:

const foo = [1,2,3,4];
const bar = [...foo].pop();

This avoids mutating foo, as .pop() would had, if we didn't used the spread operator.
That said, I like aswell the foo.slice(-1)[0] solution.

How to do paging in AngularJS?

Below solution quite simple.

<pagination  
        total-items="totalItems" 
        items-per-page= "itemsPerPage"
        ng-model="currentPage" 
        class="pagination-sm">
</pagination>

<tr ng-repeat="country in countries.slice((currentPage -1) * itemsPerPage, currentPage * itemsPerPage) "> 

Here is sample jsfiddle

What's the difference between disabled="disabled" and readonly="readonly" for HTML form input fields?

No events get triggered when the element is having disabled attribute.

None of the below will get triggered.

$("[disabled]").click( function(){ console.log("clicked") });//No Impact
$("[disabled]").hover( function(){ console.log("hovered") });//No Impact
$("[disabled]").dblclick( function(){ console.log("double clicked") });//No Impact

While readonly will be triggered.

$("[readonly]").click( function(){ console.log("clicked") });//log - clicked
$("[readonly]").hover( function(){ console.log("hovered") });//log - hovered
$("[readonly]").dblclick( function(){ console.log("double clicked") });//log - double clicked

Rails Root directory path?

You can use:

Rails.root

But to to join the assets you can use:

Rails.root.join(*%w( app assets))

Hopefully this helps you.

In Git, how do I figure out what my current revision is?

This gives you just the revision.

git rev-parse HEAD

Rails: FATAL - Peer authentication failed for user (PG::Error)

This is the most foolproof way to get your rails app working with postgres in the development environment in Ubuntu 13.10.

1) Create rails app with postgres YAML and 'pg' gem in the Gemfile:

$ rails new my_application -d postgresql

2) Give it some CRUD functionality. If you're just seeing if postgres works, create a scaffold:

$ rails g scaffold cats name:string age:integer colour:string

3) As of rails 4.0.1 the -d postgresql option generates a YAML that doesn't include a host parameter. I found I needed this. Edit the development section and create the following parameters:

encoding: UTF-8
host: localhost
database: my_application_development
username: thisismynewusername
password: thisismynewpassword 

Note the database parameter is for a database that doesn't exit yet, and the username and password are credentials for a role that doesn't exist either. We'll create those later on!

This is how config/database.yml should look (no shame in copypasting :D ):

development:
  adapter: postgresql
  pool: 5
  # these are our new parameters
  encoding: UTF-8
  database: my_application_development
  host: localhost
  username: thisismynewusername
  password: thisismynewpassword

test:
  # this won't work 
  adapter: postgresql
  encoding: unicode
  database: my_application_test
  pool: 5
  username: my_application
  password:

production:
  # this won't work 
  adapter: postgresql
  encoding: unicode
  database: my_application_production
  pool: 5
  username: my_application
  password:

4) Start the postgres shell with this command:

$ psql

4a) You may get this error if your current user (as in your computer user) doesn't have a corresponding administration postgres role.

psql: FATAL:  role "your_username" does not exist

Now I've only installed postgres once, so I may be wrong here, but I think postgres automatically creates an administration role with the same credentials as the user you installed postgres as.

4b) So this means you need to change to the user that installed postgres to use the psql command and start the shell:

$ sudo su postgres

And then run

$ psql

5) You'll know you're in the postgres shell because your terminal will look like this:

$ psql
psql (9.1.10)
Type "help" for help.

postgres=# 

6) Using the postgresql syntax, let's create the user we specified in config/database.yml's development section:

postgres=# CREATE ROLE thisismynewusername WITH LOGIN PASSWORD 'thisismynewpassword';

Now, there's some subtleties here so let's go over them.

  • The role's username, thisismynewusername, does not have quotes of any kind around it
  • Specify the keyword LOGIN after the WITH. If you don't, the role will still be created, but it won't be able to log in to the database!
  • The role's password, thisismynewpassword, needs to be in single quotes. Not double quotes.
  • Add a semi colon on the end ;)

You should see this in your terminal:

postgres=#
CREATE ROLE
postgres=#

That means, "ROLE CREATED", but postgres' alerts seem to adopt the same imperative conventions of git hub.

7) Now, still in the postgres shell, we need to create the database with the name we set in the YAML. Make the user we created in step 6 its owner:

postgres=# CREATE DATABASE my_application_development OWNER thisismynewusername;

You'll know if you were successful because you'll get the output:

CREATE DATABASE

8) Quit the postgres shell:

\q

9) Now the moment of truth:

$ RAILS_ENV=development rake db:migrate

If you get this:

==  CreateCats: migrating =================================================
-- create_table(:cats)
   -> 0.0028s
==  CreateCats: migrated (0.0028s) ========================================

Congratulations, postgres is working perfectly with your app.

9a) On my local machine, I kept getting a permission error. I can't remember it exactly, but it was an error along the lines of

Can't access the files. Change permissions to 666.

Though I'd advise thinking very carefully about recursively setting write privaledges on a production machine, locally, I gave my whole app read write privileges like this:

9b) Climb up one directory level:

$ cd ..

9c) Set the permissions of the my_application directory and all its contents to 666:

$ chmod -R 0666 my_application

9d) And run the migration again:

$ RAILS_ENV=development rake db:migrate

==  CreateCats: migrating =================================================
-- create_table(:cats)
   -> 0.0028s
==  CreateCats: migrated (0.0028s) ========================================

Some tips and tricks if you muck up

Try these before restarting all of these steps:

The mynewusername user doesn't have privileges to CRUD to the my_app_development database? Drop the database and create it again with mynewusername as the owner:

1) Start the postgres shell:

$ psql

2) Drop the my_app_development database. Be careful! Drop means utterly delete!

postgres=# DROP DATABASE my_app_development;

3) Recreate another my_app_development and make mynewusername the owner:

postgres=# CREATE DATABASE my_application_development OWNER mynewusername;

4) Quit the shell:

postgres=# \q

The mynewusername user can't log into the database? Think you wrote the wrong password in the YAML and can't quite remember the password you entered using the postgres shell? Simply alter the role with the YAML password:

1) Open up your YAML, and copy the password to your clipboard:

 development:
      adapter: postgresql
      pool: 5
      # these are our new parameters
      encoding: UTF-8
      database: my_application_development
      host: localhost
      username: thisismynewusername
      password: musthavebeenverydrunkwheniwrotethis

2) Start the postgres shell:

$ psql    

3) Update mynewusername's password. Paste in the password, and remember to put single quotes around it:

postgres=# ALTER ROLE mynewusername PASSWORD `musthavebeenverydrunkwheniwrotethis`;

4) Quit the shell:

postgres=# \q

Trying to connect to localhost via a database viewer such as Dbeaver, and don't know what your postgres user's password is? Change it like this:

1) Run passwd as a superuser:

$ sudo passwd postgres

2) Enter your accounts password for sudo (nothing to do with postgres):

[sudo] password for starkers: myaccountpassword

3) Create the postgres account's new passwod:

Enter new UNIX password: databasesarefun
Retype new UNIX password: databasesarefun
passwd: password updated successfully

Getting this error message?:

Run `$ bin/rake db:create db:migrate` to create your database
$ rake db:create db:migrate
PG::InsufficientPrivilege: ERROR:  permission denied to create database

4) You need to give your user the ability to create databases. From the psql shell:

ALTER ROLE thisismynewusername WITH CREATEDB

iPhone Safari Web App opens links in new window

One workaround i used for an iOS web app was that I made all links (which were buttons by CSS) form submit buttons. So I opened a form which posted to the destination link, then input type="submit" Not the best way, but it's what I figured out before I found this page.

How to filter a RecyclerView with a SearchView

simply create two list in adapter one orignal and one temp and implements Filterable.

    @Override
    public Filter getFilter() {
        return new Filter() {
            @Override
            protected FilterResults performFiltering(CharSequence constraint) {
                final FilterResults oReturn = new FilterResults();
                final ArrayList<T> results = new ArrayList<>();
                if (origList == null)
                    origList = new ArrayList<>(itemList);
                if (constraint != null && constraint.length() > 0) {
                    if (origList != null && origList.size() > 0) {
                        for (final T cd : origList) {
                            if (cd.getAttributeToSearch().toLowerCase()
                                    .contains(constraint.toString().toLowerCase()))
                                results.add(cd);
                        }
                    }
                    oReturn.values = results;
                    oReturn.count = results.size();//newly Aded by ZA
                } else {
                    oReturn.values = origList;
                    oReturn.count = origList.size();//newly added by ZA
                }
                return oReturn;
            }

            @SuppressWarnings("unchecked")
            @Override
            protected void publishResults(final CharSequence constraint,
                                          FilterResults results) {
                itemList = new ArrayList<>((ArrayList<T>) results.values);
                // FIXME: 8/16/2017 implement Comparable with sort below
                ///Collections.sort(itemList);
                notifyDataSetChanged();
            }
        };
    }

where

public GenericBaseAdapter(Context mContext, List<T> itemList) {
        this.mContext = mContext;
        this.itemList = itemList;
        this.origList = itemList;
    }

How to extract the decimal part from a floating point number in C?

Suppose A is your integer then (int)A, means casting the number to an integer and will be the integer part, the other is (A - (int)A)*10^n, here n is the number of decimals to keep.

Switching to landscape mode in Android Emulator

for windows try left Ctrl key with F11 or F12 or Num off 7

Implement division with bit-wise operator

Division of two numbers using bitwise operators.

#include <stdio.h>

int remainder, divisor;

int division(int tempdividend, int tempdivisor) {
    int quotient = 1;

    if (tempdivisor == tempdividend) {
        remainder = 0;
        return 1;
    } else if (tempdividend < tempdivisor) {
        remainder = tempdividend;
        return 0;
    }   

    do{

        tempdivisor = tempdivisor << 1;
        quotient = quotient << 1;

     } while (tempdivisor <= tempdividend);


     /* Call division recursively */
    quotient = quotient + division(tempdividend - tempdivisor, divisor);

    return quotient;
} 


int main() {
    int dividend;

    printf ("\nEnter the Dividend: ");
    scanf("%d", &dividend);
    printf("\nEnter the Divisor: ");
    scanf("%d", &divisor);   

    printf("\n%d / %d: quotient = %d", dividend, divisor, division(dividend, divisor));
    printf("\n%d / %d: remainder = %d", dividend, divisor, remainder);
    getch();
}

How to build splash screen in windows forms application?

First you should create a form with or without Border (border-less is preferred for these things)

public class SplashForm : Form
{
    Form _Parent;
    BackgroundWorker worker;
    public SplashForm(Form parent)
    {
         InitializeComponent();
         BackgroundWorker worker = new BackgroundWorker();
         this.worker.DoWork += new System.ComponentModel.DoWorkEventHandler(this.worker _DoWork);
         backgroundWorker1.RunWorkerAsync();
         _Parent = parent;
    }
    private void worker _DoWork(object sender, DoWorkEventArgs e)
    {
         Thread.sleep(500);
         this.hide();
         _Parent.show();
    }     
}

At Main you should use that

   static class Program
        {
            [STAThread]
            static void Main()
            {
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                Application.Run(new SplashForm());
            }
        }

How to get my project path?

This gives you the root folder:

System.AppDomain.CurrentDomain.BaseDirectory

You can navigate from here using .. or ./ etc.. , Appending .. takes you to folder where .sln file can be found

For .NET framework (thanks to Adiono comment)

Path.GetFullPath(Path.Combine(AppDomain.CurrentDomain.BaseDirectory,"..\\..\\"))

For .NET core here is a way to do it (thanks to nopara73 comment)

Path.GetFullPath(Path.Combine(AppContext.BaseDirectory, "..\\..\\..\\")) ;

Check if an array is empty or exists

How about (ECMA 5.1):

if(Array.isArray(image_array) && image_array.length){
  // array exists and is not empty
}

How to get the class of the clicked element?

$("li").click(function(){
    alert($(this).attr("class"));
});

Assign a login to a user created without login (SQL Server)

sp_change_users_login is deprecated.

Much easier is:

ALTER USER usr1 WITH LOGIN = login1;

Finding square root without using sqrt function?

if you need to find square root without using sqrt(),use root=pow(x,0.5).

Where x is value whose square root you need to find.

CentOS: Enabling GD Support in PHP Installation

CentOs 6.5+ & PHP 5.6:

sudo yum install php56-gd

service httpd restart

How to find files recursively by file type and copy them to a directory while in ssh?

Try this:

find . -name "*.pdf" -type f -exec cp {} ./pdfsfolder \;

How to get parameters from a URL string?

In Laravel, I'm use:

private function getValueFromString(string $string, string $key)
{
    parse_str(parse_url($string, PHP_URL_QUERY), $result);

    return isset($result[$key]) ? $result[$key] : null;
}

Turning error reporting off php

Tried this yet?

error_reporting(0);
@ini_set('display_errors', 0);

VSCode cannot find module '@angular/core' or any other modules

I tried a lot of stuff the guys informed here, without success. After, I just realized I was using the Deno Support for VSCode extension. I uninstalled it and a restart was required. After restart the problem was solved.

CSS container div not getting height

I ran into this same issue, and I have come up with four total viable solutions:

  1. Make the container display: flex; (this is my favorite solution)
  2. Add overflow: auto; or overflow: hidden; to the container
  3. Add the following CSS for the container:
.c:after {
    clear: both;
    content: "";
    display: block;
}
  1. Make the following the last item inside the container:
<div style="clear: both;"></div>

Fuzzy matching using T-SQL

Since the first release of Master Data Services, you've got access to more advanced fuzzy logic algorithms than what SOUNDEX implements. So provided that you've got MDS installed, you'll be able to find a function called Similarity() in the mdq schema (MDS database).

More info on how it works: http://blog.hoegaerden.be/2011/02/05/finding-similar-strings-with-fuzzy-logic-functions-built-into-mds/

Can I avoid the native fullscreen video player with HTML5 on iPhone or android?

According to this page https://developer.apple.com/library/archive/documentation/AppleApplications/Reference/SafariHTMLRef/Articles/Attributes.html it is only available if (Enabled only in a UIWebView with the allowsInlineMediaPlayback property set to YES.) I understand in Mobile Safari this is YES on iPad and NO on iPhone and iPod Touch.

Python Requests throwing SSLError

In case you have a library that relies on requests and you cannot modify the verify path (like with pyvmomi) then you'll have to find the cacert.pem bundled with requests and append your CA there. Here's a generic approach to find the cacert.pem location:

windows

C:\>python -c "import requests; print requests.certs.where()"
c:\Python27\lib\site-packages\requests-2.8.1-py2.7.egg\requests\cacert.pem

linux

#  (py2.7.5,requests 2.7.0, verify not enforced)
root@host:~/# python -c "import requests; print requests.certs.where()"
/usr/lib/python2.7/dist-packages/certifi/cacert.pem

#  (py2.7.10, verify enforced)
root@host:~/# python -c "import requests; print requests.certs.where()"
/usr/local/lib/python2.7/dist-packages/requests/cacert.pem

btw. @requests-devs, bundling your own cacerts with request is really, really annoying... especially the fact that you do not seem to use the system ca store first and this is not documented anywhere.

update

in situations, where you're using a library and have no control over the ca-bundle location you could also explicitly set the ca-bundle location to be your host-wide ca-bundle:

REQUESTS_CA_BUNDLE=/etc/ssl/certs/ca-bundle.crt python -c "import requests; requests.get('https://somesite.com';)"

git add, commit and push commands in one?

Since the question doesn't specify which shell, here's the eshell version based on the earlier answers. This goes in the eshell alias file, which might be in ~/.emacs.d/eshell/alias I've added the first part z https://github.com/rupa/z/ which let's you quickly cd to a directory, so that this can be run no matter what your current directory is.

alias census z cens; git add .; git commit -m "fast"; git push

What throws an IOException in Java?

Java documentation is helpful to know the root cause of a particular IOException.

Just have a look at the direct known sub-interfaces of IOException from the documentation page:

ChangedCharSetException, CharacterCodingException, CharConversionException, ClosedChannelException, EOFException, FileLockInterruptionException, FileNotFoundException, FilerException, FileSystemException, HttpRetryException, IIOException, InterruptedByTimeoutException, InterruptedIOException, InvalidPropertiesFormatException, JMXProviderException, JMXServerErrorException, MalformedURLException, ObjectStreamException, ProtocolException, RemoteException, SaslException, SocketException, SSLException, SyncFailedException, UnknownHostException, UnknownServiceException, UnsupportedDataTypeException, UnsupportedEncodingException, UserPrincipalNotFoundException, UTFDataFormatException, ZipException

Most of these exceptions are self-explanatory.

A few IOExceptions with root causes:

EOFException: Signals that an end of file or end of stream has been reached unexpectedly during input. This exception is mainly used by data input streams to signal the end of the stream.

SocketException: Thrown to indicate that there is an error creating or accessing a Socket.

RemoteException: A RemoteException is the common superclass for a number of communication-related exceptions that may occur during the execution of a remote method call. Each method of a remote interface, an interface that extends java.rmi.Remote, must list RemoteException in its throws clause.

UnknownHostException: Thrown to indicate that the IP address of a host could not be determined (you may not be connected to Internet).

MalformedURLException: Thrown to indicate that a malformed URL has occurred. Either no legal protocol could be found in a specification string or the string could not be parsed.

nuget 'packages' element is not declared warning

The problem is, you need a xsd schema for packages.config.

This is how you can create a schema (I found it here):

Open your Config file -> XML -> Create Schema

enter image description here

This would create a packages.xsd for you, and opens it in Visual Studio:

enter image description here

In my case, packages.xsd was created under this path:

C:\Users\MyUserName\AppData\Local\Temp

Now I don't want to reference the packages.xsd from a Temp folder, but I want it to be added to my solution and added to source control, so other users can get it... so I copied packages.xsd and pasted it into my solution folder. Then I added the file to my solution:

1. Copy packages.xsd in the same folder as your solution

2. From VS, right click on solution -> Add -> Existing Item... and then add packages.xsd

enter image description here

So, now we have created packages.xsd and added it to the Solution. All we need to do is to tell the config file to use this schema.

Open the config file, then from the top menu select:

XML -> Schemas...

Add your packages.xsd, and select Use this schema (see below)

enter image description here

String isNullOrEmpty in Java?

No, which is why so many other libraries have their own copy :)

How to get primary key column in Oracle?

Save the following script as something like findPK.sql.

set verify off
accept TABLE_NAME char prompt 'Table name>'

SELECT cols.column_name
FROM all_constraints cons NATURAL JOIN all_cons_columns cols
WHERE cons.constraint_type = 'P' AND table_name = UPPER('&TABLE_NAME');

It can then be called using

@findPK

Which versions of SSL/TLS does System.Net.WebRequest support?

I also put an answer there, but the article @Colonel Panic's update refers to suggests forcing TLS 1.2. In the future, when TLS 1.2 is compromised or just superceded, having your code stuck to TLS 1.2 will be considered a deficiency. Negotiation to TLS1.2 is enabled in .Net 4.6 by default. If you have the option to upgrade your source to .Net 4.6, I would highly recommend that change over forcing TLS 1.2.

If you do force TLS 1.2, strongly consider leaving some type of breadcrumb that will remove that force if you do upgrade to the 4.6 or higher framework.

GET and POST methods with the same Action name in the same Controller

Since you cannot have two methods with the same name and signature you have to use the ActionName attribute:

[HttpGet]
public ActionResult Index()
{
  // your code
  return View();
}

[HttpPost]
[ActionName("Index")]
public ActionResult IndexPost()
{
  // your code
  return View();
}

Also see "How a Method Becomes An Action"

Error: free(): invalid next size (fast):

It means that you have a memory error. You may be trying to free a pointer that wasn't allocated by malloc (or delete an object that wasn't created by new) or you may be trying to free/delete such an object more than once. You may be overflowing a buffer or otherwise writing to memory to which you shouldn't be writing, causing heap corruption.

Any number of programming errors can cause this problem. You need to use a debugger, get a backtrace, and see what your program is doing when the error occurs. If that fails and you determine you have corrupted the heap at some previous point in time, you may be in for some painful debugging (it may not be too painful if the project is small enough that you can tackle it piece by piece).

Proper indentation for Python multiline strings

You can use this function trim_indent.

import re


def trim_indent(s: str):
    s = re.sub(r'^\n+', '', s)
    s = re.sub(r'\n+$', '', s)
    spaces = re.findall(r'^ +', s, flags=re.MULTILINE)
    if len(spaces) > 0 and len(re.findall(r'^[^\s]', s, flags=re.MULTILINE)) == 0:
        s = re.sub(r'^%s' % (min(spaces)), '', s, flags=re.MULTILINE)
    return s


print(trim_indent("""


        line one
            line two
                line three
            line two
        line one


"""))

Result:

"""
line one
    line two
        line three
    line two
line one
"""

How can I switch to another branch in git?

If another_branch already exists locally and you are not on this branch, then git checkout another_branch switches to the branch.

If another_branch does not exist but origin/another_branch does, then git checkout another_branch is equivalent to git checkout -b another_branch origin/another_branch; git branch -u origin/another_branch. That's to create another_branch from origin/another_branch and set origin/another_branch as the upstream of another_branch.

If neither exists, git checkout another_branch returns error.

git checkout origin another_branch returns error in most cases. If origin is a revision and another_branch is a file, then it checks out the file of that revision but most probably that's not what you expect. origin is mostly used in git fetch, git pull and git push as a remote, an alias of the url to the remote repository.

git checkout origin/another_branch succeeds if origin/another_branch exists. It leads to be in detached HEAD state, not on any branch. If you make new commits, the new commits are not reachable from any existing branches and none of the branches will be updated.

UPDATE:

As 2.23.0 has been released, with it we can also use git switch to create and switch branches.

If foo exists, try to switch to foo:

git switch foo

If foo does not exist and origin/foo exists, try to create foo from origin/foo and then switch to foo:

git switch -c foo origin/foo
# or simply
git switch foo

More generally, if foo does not exist, try to create foo from a known ref or commit and then switch to foo:

git switch -c foo <ref>
git switch -c foo <commit>

If we maintain a repository in Gitlab and Github at the same time, the local repository may have two remotes, for example, origin for Gitlab and github for Github. In this case the repository has origin/foo and github/foo. git switch foo will complain fatal: invalid reference: foo, because it does not known from which ref, origin/foo or github/foo, to create foo. We need to specify it with git switch -c foo origin/foo or git switch -c foo github/foo according to the need. If we want to create branches from both remote branches, it's better to use distinguishing names for the new branches:

git switch -c gitlab_foo origin/foo
git switch -c github_foo github/foo

If foo exists, try to recreate/force-create foo from (or reset foo to) a known ref or commit and then switch to foo:

git switch -C foo <ref>
git switch -C foo <commit>

which are equivalent to:

git switch foo
git reset [<ref>|<commit>] --hard

Try to switch to a detached HEAD of a known ref or commit:

git switch -d <ref>
git switch -d <commit>

If you just want to create a branch but not switch to it, use git branch instead. Try to create a branch from a known ref or commit:

git branch foo <ref>
git branch foo <commit>

Difference between Eclipse Europa, Helios, Galileo

The Eclipse (software) page on Wikipedia summarizes it pretty well:

Releases

Since 2006, the Eclipse Foundation has coordinated an annual Simultaneous Release. Each release includes the Eclipse Platform as well as a number of other Eclipse projects. Until the Galileo release, releases were named after the moons of the solar system.

So far, each Simultaneous Release has occurred at the end of June.

Release         Main Release   Platform version      Projects
Photon          27 June 2018     4.8
Oxygen          28 June 2017     4.7                 
Neon            22 June 2016     4.6                 
Mars            24 June 2015     4.5                 Mars Projects
Luna            25 June 2014     4.4                 Luna Projects
Kepler          26 June 2013     4.3                 Kepler Projects
Juno            27 June 2012     4.2                 Juno Projects
Indigo          22 June 2011     3.7                 Indigo projects
Helios          23 June 2010     3.6                 Helios projects
Galileo         24 June 2009     3.5                 Galileo projects
Ganymede        25 June 2008     3.4                 Ganymede projects
Europa          29 June 2007     3.3                 Europa projects
Callisto        30 June 2006     3.2                 Callisto projects
Eclipse 3.1     28 June 2005     3.1  
Eclipse 3.0     28 June 2004     3.0  

To summarize, Helios, Galileo, Ganymede, etc are just code names for versions of the Eclipse platform (personally, I'd prefer Eclipse to use traditional version numbers instead of code names, it would make things clearer and easier). My suggestion would be to use the latest version, i.e. Eclipse Oxygen (4.7) (in the original version of this answer, it said "Helios (3.6.1)").

On top of the "platform", Eclipse then distributes various Packages (i.e. the "platform" with a default set of plugins to achieve specialized tasks), such as Eclipse IDE for Java Developers, Eclipse IDE for Java EE Developers, Eclipse IDE for C/C++ Developers, etc (see this link for a comparison of their content).

To develop Java Desktop applications, the Helios release of Eclipse IDE for Java Developers should suffice (you can always install "additional plugins" if required).

How to get process ID of background process?

An even simpler way to kill all child process of a bash script:

pkill -P $$

The -P flag works the same way with pkill and pgrep - it gets child processes, only with pkill the child processes get killed and with pgrep child PIDs are printed to stdout.

Check if a row exists, otherwise insert

I assume a single row for each flight? If so:

IF EXISTS (SELECT * FROM Bookings WHERE FLightID = @Id)
BEGIN
    --UPDATE HERE
END
ELSE
BEGIN
   -- INSERT HERE
END

I assume what I said, as your way of doing things can overbook a flight, as it will insert a new row when there are 10 tickets max and you are booking 20.

Any way to generate ant build.xml file automatically from Eclipse?

Take a look at the .classpath file in your project, which probably contains most of the information that you want. The easiest option may be to roll your own "build.xml export", i.e. process .classpath into a new build.xml during the build itself, and then call it with an ant subtask.

Parsing a little XML sounds much easier to me than to hook into Eclipse JDT.

Insert multiple rows into single column

I believe this should work for inserting multiple rows:

INSERT INTO Data ( Col1 ) VALUES
('Hello'), ('World'),...

Avoiding NullPointerException in Java

If you are using java8 or later go for the isNull(yourObject) from java.util.Objects.

Example:-

String myObject = null;

Objects.isNull(myObject); //will return true

Usage: The below code returns a non null value (if the name is not null then that value will be returned else the default value will be returned).

final String name = "Jobin";
String nonNullValue = Optional.ofNullable(name).filter(Objects::nonNull).orElse("DefaultName");

SSL Error: unable to get local issuer certificate

jww is right — you're referencing the wrong intermediate certificate.

As you have been issued with a SHA256 certificate, you will need the SHA256 intermediate. You can grab it from here: http://secure2.alphassl.com/cacert/gsalphasha2g2r1.crt

Chrome & Safari Error::Not allowed to load local resource: file:///D:/CSS/Style.css

I know this post is old but here is what I found. It doesn't work when I link it this way(with / before css/style.csson the href attribute.

<link rel="stylesheet" media="all" href="/CSS/Style.css" type="text/css" />

However, when I removed / I'm able to link properly with the css file It should be like this(without /).

<link rel="stylesheet" media="all" href="CSS/Style.css" type="text/css" />

This was giving me trouble on my project. Hope it will help somebody else.

How do I check if a file exists in Java?

Using Java 8:

if(Files.exists(Paths.get(filePathString))) { 
    // do something
}

How can I beautify JSON programmatically?

Programmatic formatting solution:

The JSON.stringify method supported by many modern browsers (including IE8) can output a beautified JSON string:

JSON.stringify(jsObj, null, "\t"); // stringify with tabs inserted at each level
JSON.stringify(jsObj, null, 4);    // stringify with 4 spaces at each level
Demo: http://jsfiddle.net/AndyE/HZPVL/

This method is also included with json2.js, for supporting older browsers.

Manual formatting solution

If you don't need to do it programmatically, Try JSON Lint. Not only will it prettify your JSON, it will validate it at the same time.

Calculating the sum of two variables in a batch script

You need to use the property /a on the set command.

For example,

set /a "c=%a%+%b%"

This allows you to use arithmetic expressions in the set command, rather than simple concatenation.

Your code would then be:

@set a=3
@set b=4
@set /a "c=%a%+%b%"
echo %c%
@set /a "d=%c%+1"
echo %d%

and would output:

7
8

How can I catch a ctrl-c event?

signal isn't the most reliable way as it differs in implementations. I would recommend using sigaction. Tom's code would now look like this :

#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>

void my_handler(int s){
           printf("Caught signal %d\n",s);
           exit(1); 

}

int main(int argc,char** argv)
{

   struct sigaction sigIntHandler;

   sigIntHandler.sa_handler = my_handler;
   sigemptyset(&sigIntHandler.sa_mask);
   sigIntHandler.sa_flags = 0;

   sigaction(SIGINT, &sigIntHandler, NULL);

   pause();

   return 0;    
}

Official reasons for "Software caused connection abort: socket write error"

For anyone using simple Client Server programms and getting this error, it is a problem of unclosed (or closed to early) Input or Output Streams.

Remove characters except digits from string using Python?

You can easily do it using Regex

>>> import re
>>> re.sub("\D","","£70,000")
70000

CUSTOM_ELEMENTS_SCHEMA added to NgModule.schemas still showing Error

I'd like to add one additional piece of information since the accepted answer above didn't fix my errors completely.

In my scenario, I have a parent component, which holds a child component. And that child component also contains another component.

So, my parent component's spec file need to have the declaration of the child component, AS WELL AS THE CHILD'S CHILD COMPONENT. That finally fixed the issue for me.

How to escape indicator characters (i.e. : or - ) in YAML

I came here trying to get my Azure DevOps Command Line task working. The thing that worked for me was using the pipe (|) character. Using > did not work.

Example:

steps:
- task: CmdLine@2
  inputs:
    script: |
      echo "Selecting Mono version..."
      /bin/bash -c "sudo $AGENT_HOMEDIRECTORY/scripts/select-xamarin-sdk.sh 5_18_1"
      echo "Selecting Xcode version..."
      /bin/bash -c "echo '##vso[task.setvariable variable=MD_APPLE_SDK_ROOT;]'/Applications/Xcode_10.2.1.app;sudo xcode-select --switch /Applications/Xcode_10.2.1.app/Contents/Developer"

Create controller for partial view in ASP.NET MVC

Why not use Html.RenderAction()?

Then you could put the following into any controller (even creating a new controller for it):

[ChildActionOnly]
public ActionResult MyActionThatGeneratesAPartial(string parameter1)
{
    var model = repository.GetThingByParameter(parameter1);
    var partialViewModel = new PartialViewModel(model);
    return PartialView(partialViewModel); 
}

Then you could create a new partial view and have your PartialViewModel be what it inherits from.

For Razor, the code block in the view would look like this:

@{ Html.RenderAction("Index", "Home"); }

For the WebFormsViewEngine, it would look like this:

<% Html.RenderAction("Index", "Home"); %>

Java 8 Streams FlatMap method example

This method takes one Function as an argument, this function accepts one parameter T as an input argument and return one stream of parameter R as a return value. When this function is applied on each element of this stream, it produces a stream of new values. All the elements of these new streams generated by each element are then copied to a new stream, which will be a return value of this method.

http://codedestine.com/java-8-stream-flatmap-method/

MySql: Tinyint (2) vs tinyint(1) - what is the difference?

mysql> CREATE TABLE tin3(id int PRIMARY KEY,val TINYINT(10) ZEROFILL);
Query OK, 0 rows affected (0.04 sec)

mysql> INSERT INTO tin3 VALUES(1,12),(2,7),(4,101);
Query OK, 3 rows affected (0.02 sec)
Records: 3  Duplicates: 0  Warnings: 0

mysql> SELECT * FROM tin3;
+----+------------+
| id | val        |
+----+------------+
|  1 | 0000000012 |
|  2 | 0000000007 |
|  4 | 0000000101 |
+----+------------+
3 rows in set (0.00 sec)

mysql>

mysql> SELECT LENGTH(val) FROM tin3 WHERE id=2;
+-------------+
| LENGTH(val) |
+-------------+
|          10 |
+-------------+
1 row in set (0.01 sec)


mysql> SELECT val+1 FROM tin3 WHERE id=2;
+-------+
| val+1 |
+-------+
|     8 |
+-------+
1 row in set (0.00 sec)

Could not find a base address that matches scheme https for the endpoint with binding WebHttpBinding. Registered base address schemes are [http]

To make it work you have to replace a run this line of code serviceMetadata httpGetEnabled="true"/> http instead of https and security mode="None" />

What do <o:p> elements do anyway?

Couldn't find any official documentation (no surprise there) but according to this interesting article, those elements are injected in order to enable Word to convert the HTML back to fully compatible Word document, with everything preserved.

The relevant paragraph:

Microsoft added the special tags to Word's HTML with an eye toward backward compatibility. Microsoft wanted you to be able to save files in HTML complete with all of the tracking, comments, formatting, and other special Word features found in traditional DOC files. If you save a file in HTML and then reload it in Word, theoretically you don't loose anything at all.

This makes lots of sense.

For your specific question.. the o in the <o:p> means "Office namespace" so anything following the o: in a tag means "I'm part of Office namespace" - in case of <o:p> it just means paragraph, the equivalent of the ordinary <p> tag.

I assume that every HTML tag has its Office "equivalent" and they have more.

Converting NSString to NSDate (and back again)

UPDATE 2019 (Swift 4):

Made a Date extension for that. It uses NSDataDetector instead of NSDateFormatter.

// Just throw at it without any format.
var date: Date? = Date.FromString("02-14-2019 17:05:05")

Pretty enjoyable, it even recognizes things like "Tomorrow at 5".

XCTAssertEqual(Date.FromString("2019-02-14"),                    Date.FromCalendar(2019, 2, 14))
XCTAssertEqual(Date.FromString("2019.02.14"),                    Date.FromCalendar(2019, 2, 14))
XCTAssertEqual(Date.FromString("2019/02/14"),                    Date.FromCalendar(2019, 2, 14))
XCTAssertEqual(Date.FromString("2019 Feb 14"),                   Date.FromCalendar(2019, 2, 14))
XCTAssertEqual(Date.FromString("2019 Feb 14th"),                 Date.FromCalendar(2019, 2, 14))
XCTAssertEqual(Date.FromString("20190214"),                      Date.FromCalendar(2019, 2, 14))
XCTAssertEqual(Date.FromString("02-14-2019"),                    Date.FromCalendar(2019, 2, 14))
XCTAssertEqual(Date.FromString("02.14.2019 5:00 PM"),            Date.FromCalendar(2019, 2, 14, 17))
XCTAssertEqual(Date.FromString("02/14/2019 17:00"),              Date.FromCalendar(2019, 2, 14, 17))
XCTAssertEqual(Date.FromString("14 February 2019 at 5 hour"),    Date.FromCalendar(2019, 2, 14, 17))
XCTAssertEqual(Date.FromString("02-14-2019 17:05:05"),           Date.FromCalendar(2019, 2, 14, 17, 05, 05))
XCTAssertEqual(Date.FromString("17:05, 14 February 2019 (UTC)"), Date.FromCalendar(2019, 2, 14, 17, 05))
XCTAssertEqual(Date.FromString("02-14-2019 17:05:05 GMT"),       Date.FromCalendar(2019, 2, 14, 17, 05, 05))
XCTAssertEqual(Date.FromString("02-13-2019 Tomorrow"),           Date.FromCalendar(2019, 2, 14))
XCTAssertEqual(Date.FromString("2019 Feb 14th Tomorrow at 5"),   Date.FromCalendar(2019, 2, 14, 17))

Goes like:

extension Date
{


    public static func FromString(_ dateString: String) -> Date?
    {
        // Date detector.
        let detector = try! NSDataDetector(types: NSTextCheckingResult.CheckingType.date.rawValue)

        // Enumerate matches.
        var matchedDate: Date?
        var matchedTimeZone: TimeZone?
        detector.enumerateMatches(
            in: dateString,
            options: [],
            range: NSRange(location: 0, length: dateString.utf16.count),
            using:
            {
                (eachResult, _, _) in

                // Lookup matches.
                matchedDate = eachResult?.date
                matchedTimeZone = eachResult?.timeZone

                // Convert to GMT (!) if no timezone detected.
                if matchedTimeZone == nil, let detectedDate = matchedDate
                { matchedDate = Calendar.current.date(byAdding: .second, value: TimeZone.current.secondsFromGMT(), to: detectedDate)! }
        })

        // Result.
        return matchedDate
    }
}

UPDATE 2014:

Made an NSString extension for that.

// Simple as this.   
date = dateString.dateValue;

Thanks to NSDataDetector, it recognizes a whole lot of format.

'2014-01-16' dateValue is <2014-01-16 11:00:00 +0000>
'2014.01.16' dateValue is <2014-01-16 11:00:00 +0000>
'2014/01/16' dateValue is <2014-01-16 11:00:00 +0000>
'2014 Jan 16' dateValue is <2014-01-16 11:00:00 +0000>
'2014 Jan 16th' dateValue is <2014-01-16 11:00:00 +0000>
'20140116' dateValue is <2014-01-16 11:00:00 +0000>
'01-16-2014' dateValue is <2014-01-16 11:00:00 +0000>
'01.16.2014' dateValue is <2014-01-16 11:00:00 +0000>
'01/16/2014' dateValue is <2014-01-16 11:00:00 +0000>
'16 January 2014' dateValue is <2014-01-16 11:00:00 +0000>
'01-16-2014 17:05:05' dateValue is <2014-01-16 16:05:05 +0000>
'01-16-2014 T 17:05:05 UTC' dateValue is <2014-01-16 17:05:05 +0000>
'17:05, 1 January 2014 (UTC)' dateValue is <2014-01-01 16:05:00 +0000>

Part of eppz!kit, grab the category NSString+EPPZKit.h from GitHub.


ORIGINAL ANSWER 2013:

Whether you're not sure (or don't care) about the date format contained in the string, use NSDataDetector for parsing date.

//Role players.
NSString *dateString = @"Wed, 03 Jul 2013 02:16:02 -0700";
__block NSDate *detectedDate;

//Detect.
NSDataDetector *detector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingAllTypes error:nil];
[detector enumerateMatchesInString:dateString
                           options:kNilOptions
                             range:NSMakeRange(0, [dateString length])
                        usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop)
{ detectedDate = result.date; }];

Last segment of URL in jquery

// Store original location in loc like: http://test.com/one/ (ending slash)
var loc = location.href; 
// If the last char is a slash trim it, otherwise return the original loc
loc = loc.lastIndexOf('/') == (loc.length -1) ? loc.substr(0,loc.length-1) : loc.substr(0,loc.lastIndexOf('/'));
var targetValue = loc.substr(loc.lastIndexOf('/') + 1);

targetValue = one

If your url looks like:

http://test.com/one/

or

http://test.com/one

or

http://test.com/one/index.htm

Then loc ends up looking like: http://test.com/one

Now, since you want the last item, run the next step to load the value (targetValue) you originally wanted.

var targetValue = loc.substr(loc.lastIndexOf('/') + 1);

I want to show all tables that have specified column name

Pretty simple on a per database level

Use DatabaseName
Select * From INFORMATION_SCHEMA.COLUMNS Where column_name = 'ColName'

How to remove last n characters from a string in Bash?

First, it's usually better to be explicit about your intent. So if you know the string ends in .rtf, and you want to remove that .rtf, you can just use var2=${var%.rtf}. One potentially-useful aspect of this approach is that if the string doesn't end in .rtf, it is not changed at all; var2 will contain an unmodified copy of var.

If you want to remove a filename suffix but don't know or care exactly what it is, you can use var2=${var%.*} to remove everything starting with the last .. Or, if you only want to keep everything up to but not including the first ., you can use var2=${var%%.*}. Those options have the same result if there's only one ., but if there might be more than one, you get to pick which end of the string to work from. On the other hand, if there's no . in the string at all, var2 will again be an unchanged copy of var.

If you really want to always remove a specific number of characters, here are some options.

You tagged this bash specifically, so we'll start with bash builtins. The one which has worked the longest is the same suffix-removal syntax I used above: to remove four characters, use var2=${var%????}. Or to remove four characters only if the first one is a dot, use var2=${var%.???}, which is like var2=${var%.*} but only removes the suffix if the part after the dot is exactly three characters. As you can see, to count characters this way, you need one question mark per unknown character removed, so this approach gets unwieldy for larger substring lengths.

An option in newer shell versions is substring extraction: var2=${var:0:${#var}-4}. Here you can put any number in place of the 4 to remove a different number of characters. The ${#var} is replaced by the length of the string, so this is actually asking to extract and keep (length - 4) characters starting with the first one (at index 0). With this approach, you lose the option to make the change only if the string matches a pattern; no matter what the actual value of the string is, the copy will include all but its last four characters.

Bash lets you leave the start index out; it defaults to 0, so you can shorten that to just var2=${var::${#var}-4}. In fact, newer versions of bash (specifically 4+, which means the one that ships with MacOS won't work) recognize negative lengths as end indexes counting back from the end of the string, so you can get rid of the string-length expression, too: var2=${var::-4}.

If you're not actually using bash but some other POSIX-type shell, the pattern-based suffix removal with % will still work – even in plain old dash, where the index-based substring extraction won't. Ksh and zsh do both support substring extraction, but require the explicit 0 start index; zsh also supports the negative end index, while ksh requires the length expression. Note that zsh, which indexes arrays starting at 1, nonetheless indexes strings starting at 0 if you use this bash-compatible syntax; but you can also treat parameters as arrays of characters, in which case it uses a 1-based count and expects a start and inclusive end position in brackets: var2=$var[1,-5].

Instead of using built-in shell parameter expansion, you can of course run some utility program to modify the string and capture its output with command substitution. There are several commands that will work; one is var2=$(sed 's/.\{4\}$//' <<<"$var").

How to apply a function to two columns of Pandas dataframe

There is a clean, one-line way of doing this in Pandas:

df['col_3'] = df.apply(lambda x: f(x.col_1, x.col_2), axis=1)

This allows f to be a user-defined function with multiple input values, and uses (safe) column names rather than (unsafe) numeric indices to access the columns.

Example with data (based on original question):

import pandas as pd

df = pd.DataFrame({'ID':['1', '2', '3'], 'col_1': [0, 2, 3], 'col_2':[1, 4, 5]})
mylist = ['a', 'b', 'c', 'd', 'e', 'f']

def get_sublist(sta,end):
    return mylist[sta:end+1]

df['col_3'] = df.apply(lambda x: get_sublist(x.col_1, x.col_2), axis=1)

Output of print(df):

  ID  col_1  col_2      col_3
0  1      0      1     [a, b]
1  2      2      4  [c, d, e]
2  3      3      5  [d, e, f]

If your column names contain spaces or share a name with an existing dataframe attribute, you can index with square brackets:

df['col_3'] = df.apply(lambda x: f(x['col 1'], x['col 2']), axis=1)

In PHP, how can I add an object element to an array?

Here is a clean method I've discovered:

$myArray = [];

array_push($myArray, (object)[
        'key1' => 'someValue',
        'key2' => 'someValue2',
        'key3' => 'someValue3',
]);

return $myArray;

Set value for particular cell in pandas DataFrame using index

If you want to change values not for whole row, but only for some columns:

x = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]})
x.iloc[1] = dict(A=10, B=-10)

Loading state button in Bootstrap 3

You need to detect the click from js side, your HTML remaining same. Note: this method is deprecated since v3.5.5 and removed in v4.

$("button").click(function() {
    var $btn = $(this);
    $btn.button('loading');
    // simulating a timeout
    setTimeout(function () {
        $btn.button('reset');
    }, 1000);
});

Also, don't forget to load jQuery and Bootstrap js (based on jQuery) file in your page.

JSFIDDLE

Official Documentation

how to remove json object key and value.?

Follow this, it can be like what you are looking:

_x000D_
_x000D_
var obj = {_x000D_
    Objone: 'one',_x000D_
    Objtwo: 'two'_x000D_
};_x000D_
_x000D_
var key = "Objone";_x000D_
delete obj[key];_x000D_
console.log(obj); // prints { "objtwo": two}
_x000D_
_x000D_
_x000D_

Copy rows from one Datatable to another DataTable?

As a result of the other posts, this is the shortest I could get:

DataTable destTable = sourceTable.Clone();
sourceTable.AsEnumerable().Where(row => /* condition */ ).ToList().ForEach(row => destTable.ImportRow(row));

Configuring user and password with Git Bash

From Git Bash I prefer to run the command:

git config --global credential.helper wincred

At that point running a command like git pull and entering your credentials one time should have it stored for future use. Git has a built-in credentials system that works in different OS environments. You can get more details here: 7.14 Git Tools - Credential Storage

How to clean old dependencies from maven repositories?

I wanted to remove old dependencies from my Maven repository as well. I thought about just running Florian's answer, but I wanted something that I could run over and over without remembering a long linux snippet, and I wanted something with a little bit of configurability -- more of a program, less of a chain of unix commands, so I took the base idea and made it into a (relatively small) Ruby program, which removes old dependencies based on their last access time.

It doesn't remove "old versions" but since you might actually have two different active projects with two different versions of a dependency, that wouldn't have done what I wanted anyway. Instead, like Florian's answer, it removes dependencies that haven't been accessed recently.

If you want to try it out, you can:

  1. Visit the GitHub repository
  2. Clone the repository, or download the source
  3. Optionally inspect the code to make sure it's not malicious
  4. Run bin/mvnclean

There are options to override the default Maven repository, ignore files, set the threshold date, but you can read those in the README on GitHub.

I'll probably package it as a Ruby gem at some point after I've done a little more work on it, which will simplify matters (gem install mvnclean; mvnclean) if you already have Ruby installed and operational.

Is it safe to store a JWT in localStorage with ReactJS?

Localstorage is designed to be accessible by javascript, so it doesn't provide any XSS protection. As mentioned in other answers, there is a bunch of possible ways to do an XSS attack, from which localstorage is not protected by default.

However, cookies have security flags which protect from XSS and CSRF attacks. HttpOnly flag prevents client side javascript from accessing the cookie, Secure flag only allows the browser to transfer the cookie through ssl, and SameSite flag ensures that the cookie is sent only to the origin. Although I just checked and SameSite is currently supported only in Opera and Chrome, so to protect from CSRF it's better to use other strategies. For example, sending an encrypted token in another cookie with some public user data.

So cookies are a more secure choice for storing authentication data.

Best way to extract a subvector from a vector?

These days, we use spans! So you would write:

#include <gsl/span>

...
auto start_pos = 100000;
auto length = 1000;
auto span_of_myvec = gsl::make_span(myvec);
auto my_subspan = span_of_myvec.subspan(start_pos, length);

to get a span of 1000 elements of the same type as myvec's. Or a more terse form:

auto my_subspan = gsl::make_span(myvec).subspan(1000000, 1000);

(but I don't like this as much, since the meaning of each numeric argument is not entirely clear; and it gets worse if the length and start_pos are of the same order of magnitude.)

Anyway, remember that this is not a copy, it's just a view of the data in the vector, so be careful. If you want an actual copy, you could do:

std::vector<T> new_vec(my_subspan.cbegin(), my_subspan.cend());

Notes:

How to use global variable in node.js?

May be following is better to avoid the if statement:

global.logger || (global.logger = require('my_logger'));

How can I assign the output of a function to a variable using bash?

You may use bash functions in commands/pipelines as you would otherwise use regular programs. The functions are also available to subshells and transitively, Command Substitution:

VAR=$(scan)

Is the straighforward way to achieve the result you want in most cases. I will outline special cases below.

Preserving trailing Newlines:

One of the (usually helpful) side effects of Command Substitution is that it will strip any number of trailing newlines. If one wishes to preserve trailing newlines, one can append a dummy character to output of the subshell, and subsequently strip it with parameter expansion.

function scan2 () {
    local nl=$'\x0a';  # that's just \n
    echo "output${nl}${nl}" # 2 in the string + 1 by echo
}

# append a character to the total output.
# and strip it with %% parameter expansion.
VAR=$(scan2; echo "x"); VAR="${VAR%%x}"

echo "${VAR}---"

prints (3 newlines kept):

output


---

Use an output parameter: avoiding the subshell (and preserving newlines)

If what the function tries to achieve is to "return" a string into a variable , with bash v4.3 and up, one can use what's called a nameref. Namerefs allows a function to take the name of one or more variables output parameters. You can assign things to a nameref variable, and it is as if you changed the variable it 'points to/references'.

function scan3() {
    local -n outvar=$1    # -n makes it a nameref.
    local nl=$'\x0a'
    outvar="output${nl}${nl}"  # two total. quotes preserve newlines
}

VAR="some prior value which will get overwritten"

# you pass the name of the variable. VAR will be modified.
scan3 VAR

# newlines are also preserved.
echo "${VAR}==="

prints:

output

===

This form has a few advantages. Namely, it allows your function to modify the environment of the caller without using global variables everywhere.

Note: using namerefs can improve the performance of your program greatly if your functions rely heavily on bash builtins, because it avoids the creation of a subshell that is thrown away just after. This generally makes more sense for small functions reused often, e.g. functions ending in echo "$returnstring"

This is relevant. https://stackoverflow.com/a/38997681/5556676

How can I initialize a C# List in the same line I declare it. (IEnumerable string Collection Example)

This is one way.

List<int> list = new List<int>{ 1, 2, 3, 4, 5 };

This is another way.

List<int> list2 = new List<int>();

list2.Add(1);

list2.Add(2);

Same goes with strings.

Eg:

List<string> list3 = new List<string> { "Hello", "World" };

Removing empty lines in Notepad++

  1. Press ctrl + h (Shortcut for replace).
  2. In the Find what zone, type ^\R ( for exact empty lines) or ^\h*\R ( for empty lines with blanks, only).
  3. Leave the Replace with zone empty.
  4. Check the Wrap around option.
  5. Select the Regular expression search mode.
  6. Click on the Replace All button.

enter image description here

Where to place $PATH variable assertions in zsh?

Here is the docs from the zsh man pages under STARTUP/SHUTDOWN FILES section.

   Commands  are  first  read from /etc/zshenv this cannot be overridden.
   Subsequent behaviour is modified by the RCS and GLOBAL_RCS options; the
   former  affects all startup files, while the second only affects global
   startup files (those shown here with an path starting with  a  /).   If
   one  of  the  options  is  unset  at  any point, any subsequent startup
   file(s) of the corresponding type will not be read.  It is also  possi-
   ble  for  a  file  in  $ZDOTDIR  to  re-enable GLOBAL_RCS. Both RCS and
   GLOBAL_RCS are set by default.

   Commands are then read from $ZDOTDIR/.zshenv.  If the shell is a  login
   shell,  commands  are  read from /etc/zprofile and then $ZDOTDIR/.zpro-
   file.  Then, if the  shell  is  interactive,  commands  are  read  from
   /etc/zshrc  and then $ZDOTDIR/.zshrc.  Finally, if the shell is a login
   shell, /etc/zlogin and $ZDOTDIR/.zlogin are read.

From this we can see the order files are read is:

/etc/zshenv    # Read for every shell
~/.zshenv      # Read for every shell except ones started with -f
/etc/zprofile  # Global config for login shells, read before zshrc
~/.zprofile    # User config for login shells
/etc/zshrc     # Global config for interactive shells
~/.zshrc       # User config for interactive shells
/etc/zlogin    # Global config for login shells, read after zshrc
~/.zlogin      # User config for login shells
~/.zlogout     # User config for login shells, read upon logout
/etc/zlogout   # Global config for login shells, read after user logout file

You can get more information here.

OnChange event using React JS for drop down

The change event is triggered on the <select> element, not the <option> element. However, that's not the only problem. The way you defined the change function won't cause a rerender of the component. It seems like you might not have fully grasped the concept of React yet, so maybe "Thinking in React" helps.

You have to store the selected value as state and update the state when the value changes. Updating the state will trigger a rerender of the component.

var MySelect = React.createClass({
     getInitialState: function() {
         return {
             value: 'select'
         }
     },
     change: function(event){
         this.setState({value: event.target.value});
     },
     render: function(){
        return(
           <div>
               <select id="lang" onChange={this.change} value={this.state.value}>
                  <option value="select">Select</option>
                  <option value="Java">Java</option>
                  <option value="C++">C++</option>
               </select>
               <p></p>
               <p>{this.state.value}</p>
           </div>
        );
     }
});

React.render(<MySelect />, document.body);

Also note that <p> elements don't have a value attribute. React/JSX simply replicates the well-known HTML syntax, it doesn't introduce custom attributes (with the exception of key and ref). If you want the selected value to be the content of the <p> element then simply put inside of it, like you would do with any static content.

Learn more about event handling, state and form controls:

What is the Java equivalent for LINQ?

There are many LINQ equivalents for Java, see here for a comparison.

For a typesafe Quaere/LINQ style framework, consider using Querydsl. Querydsl supports JPA/Hibernate, JDO, SQL and Java Collections.

I am the maintainer of Querydsl, so this answer is biased.

Execute script after specific delay using JavaScript

why can't you put the code behind a promise? (typed in off the top of my head)

_x000D_
_x000D_
new Promise(function(resolve, reject) {_x000D_
  setTimeout(resolve, 2000);_x000D_
}).then(function() {_x000D_
  console.log('do whatever you wanted to hold off on');_x000D_
});
_x000D_
_x000D_
_x000D_

Why can't variables be declared in a switch statement?

I just wanted to emphasize slim's point. A switch construct creates a whole, first-class-citizen scope. So it is posible to declare (and initialize) a variable in a switch statement before the first case label, without an additional bracket pair:

switch (val) {  
  /* This *will* work, even in C89 */
  int newVal = 42;  
case VAL:
  newVal = 1984; 
  break;
case ANOTHER_VAL:  
  newVal = 2001;
  break;
}

Colors in JavaScript console

There are a series of inbuilt functions for coloring the console log:

//For pink background and red text
console.error("Hello World");  

//For yellow background and brown text
console.warn("Hello World");  

//For just a INFO symbol at the beginning of the text
console.info("Hello World");  

//for custom colored text
console.log('%cHello World','color:blue');
//here blue could be replaced by any color code

//for custom colored text with custom background text
console.log('%cHello World','background:red;color:#fff')

ViewBag, ViewData and TempData

TempData

Basically it's like a DataReader, once read, data will be lost.

Check this Video

Example

public class HomeController : Controller
{
    public ActionResult Index()
    {
        ViewBag.Message = "Welcome to ASP.NET MVC!";
        TempData["T"] = "T";
        return RedirectToAction("About");
    }

    public ActionResult About()
    {
        return RedirectToAction("Test1");
    }

    public ActionResult Test1()
    {
        String str = TempData["T"]; //Output - T
        return View();
    }
}

If you pay attention to the above code, RedirectToAction has no impact over the TempData until TempData is read. So, once TempData is read, values will be lost.

How can i keep the TempData after reading?

Check the output in Action Method Test 1 and Test 2

public class HomeController : Controller
{
    public ActionResult Index()
    {
        ViewBag.Message = "Welcome to ASP.NET MVC!";
        TempData["T"] = "T";
        return RedirectToAction("About");
    }

    public ActionResult About()
    {
        return RedirectToAction("Test1");
    }

    public ActionResult Test1()
    {
        string Str = Convert.ToString(TempData["T"]);
        TempData.Keep(); // Keep TempData
        return RedirectToAction("Test2");
    }

    public ActionResult Test2()
    {
        string Str = Convert.ToString(TempData["T"]); //OutPut - T
        return View();
    }
}

If you pay attention to the above code, data is not lost after RedirectToAction as well as after Reading the Data and the reason is, We are using TempData.Keep(). is that

In this way you can make it persist as long as you wish in other controllers also.

ViewBag/ViewData

The Data will persist to the corresponding View

How to get HttpContext.Current in ASP.NET Core?

Necromancing.
YES YOU CAN, and this is how.
A secret tip for those migrating large junks chunks of code:
The following method is an evil carbuncle of a hack which is actively engaged in carrying out the express work of satan (in the eyes of .NET Core framework developers), but it works:

In public class Startup

add a property

public IConfigurationRoot Configuration { get; }

And then add a singleton IHttpContextAccessor to DI in ConfigureServices.

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddSingleton<Microsoft.AspNetCore.Http.IHttpContextAccessor, Microsoft.AspNetCore.Http.HttpContextAccessor>();

Then in Configure

    public void Configure(
              IApplicationBuilder app
             ,IHostingEnvironment env
             ,ILoggerFactory loggerFactory
    )
    {

add the DI Parameter IServiceProvider svp, so the method looks like:

    public void Configure(
           IApplicationBuilder app
          ,IHostingEnvironment env
          ,ILoggerFactory loggerFactory
          ,IServiceProvider svp)
    {

Next, create a replacement class for System.Web:

namespace System.Web
{

    namespace Hosting
    {
        public static class HostingEnvironment 
        {
            public static bool m_IsHosted;

            static HostingEnvironment()
            {
                m_IsHosted = false;
            }

            public static bool IsHosted
            {
                get
                {
                    return m_IsHosted;
                }
            }
        }
    }


    public static class HttpContext
    {
        public static IServiceProvider ServiceProvider;

        static HttpContext()
        { }


        public static Microsoft.AspNetCore.Http.HttpContext Current
        {
            get
            {
                // var factory2 = ServiceProvider.GetService<Microsoft.AspNetCore.Http.IHttpContextAccessor>();
                object factory = ServiceProvider.GetService(typeof(Microsoft.AspNetCore.Http.IHttpContextAccessor));

                // Microsoft.AspNetCore.Http.HttpContextAccessor fac =(Microsoft.AspNetCore.Http.HttpContextAccessor)factory;
                Microsoft.AspNetCore.Http.HttpContext context = ((Microsoft.AspNetCore.Http.HttpContextAccessor)factory).HttpContext;
                // context.Response.WriteAsync("Test");

                return context;
            }
        }


    } // End Class HttpContext 


}

Now in Configure, where you added the IServiceProvider svp, save this service provider into the static variable "ServiceProvider" in the just created dummy class System.Web.HttpContext (System.Web.HttpContext.ServiceProvider)

and set HostingEnvironment.IsHosted to true

System.Web.Hosting.HostingEnvironment.m_IsHosted = true;

this is essentially what System.Web did, just that you never saw it (I guess the variable was declared as internal instead of public).

// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IServiceProvider svp)
{
    loggerFactory.AddConsole(Configuration.GetSection("Logging"));
    loggerFactory.AddDebug();

    ServiceProvider = svp;
    System.Web.HttpContext.ServiceProvider = svp;
    System.Web.Hosting.HostingEnvironment.m_IsHosted = true;


    app.UseCookieAuthentication(new CookieAuthenticationOptions()
    {
        AuthenticationScheme = "MyCookieMiddlewareInstance",
        LoginPath = new Microsoft.AspNetCore.Http.PathString("/Account/Unauthorized/"),
        AccessDeniedPath = new Microsoft.AspNetCore.Http.PathString("/Account/Forbidden/"),
        AutomaticAuthenticate = true,
        AutomaticChallenge = true,
        CookieSecure = Microsoft.AspNetCore.Http.CookieSecurePolicy.SameAsRequest

       , CookieHttpOnly=false

    });

Like in ASP.NET Web-Forms, you'll get a NullReference when you're trying to access a HttpContext when there is none, such as it used to be in Application_Start in global.asax.

I stress again, this only works if you actually added

services.AddSingleton<Microsoft.AspNetCore.Http.IHttpContextAccessor, Microsoft.AspNetCore.Http.HttpContextAccessor>();

like I wrote you should.
Welcome to the ServiceLocator pattern within the DI pattern ;)
For risks and side effects, ask your resident doctor or pharmacist - or study the sources of .NET Core at github.com/aspnet, and do some testing.


Perhaps a more maintainable method would be adding this helper class

namespace System.Web
{

    public static class HttpContext
    {
        private static Microsoft.AspNetCore.Http.IHttpContextAccessor m_httpContextAccessor;


        public static void Configure(Microsoft.AspNetCore.Http.IHttpContextAccessor httpContextAccessor)
        {
            m_httpContextAccessor = httpContextAccessor;
        }


        public static Microsoft.AspNetCore.Http.HttpContext Current
        {
            get
            {
                return m_httpContextAccessor.HttpContext;
            }
        }


    }


}

And then calling HttpContext.Configure in Startup->Configure

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IServiceProvider svp)
{
    loggerFactory.AddConsole(Configuration.GetSection("Logging"));
    loggerFactory.AddDebug();


    System.Web.HttpContext.Configure(app.ApplicationServices.
        GetRequiredService<Microsoft.AspNetCore.Http.IHttpContextAccessor>()
    );

How do I change Eclipse to use spaces instead of tabs?

Eclipse IDE for C/C++ Developers, Version: Helios Service Release 2

You need to create new profile by pressing New button inside "Window->Preferences->Code Style"

Go to Indentation tab and select "Tab policy = Space only"


Eclipse IDE for C/C++ Developers, Version: Kepler Service Release 1

Follow the path below to create new profile: "Window > Preferences > C/C++ > Code Style > Formatter"

Go to Indentation tab and select "Tab policy = Space only"

Converting VS2012 Solution to VS2010

Simple solution which worked for me.

  1. Install Vim editor for windows.
  2. Open VS 2012 project solution using Vim editor and modify the version targetting Visual studio solution 10.
  3. Open solution with Visual studio 2010.. and continue with your work ;)

MySQL: Enable LOAD DATA LOCAL INFILE

All: Evidently this is working as designed. Please see new ref man dated 2019-7-23, Section 6.1.6, Security Issues with LOAD DATA LOCAL.

AngularJS format JSON string output

If you want to format the JSON and also do some syntax highlighting, you can use the ng-prettyjson directive. See the npm package.

Here is how to use it: <pre pretty-json="jsonObject"></pre>

What is the better API to Reading Excel sheets in java - JXL or Apache POI

I have used POI.

If you use that, keep on eye those cell formatters: create one and use it several times instead of creating each time for cell, it isa huge memory consumption difference or large data.

How to program a fractal?

Here is a codepen that I wrote for the Mandelbrot fractal using plain javascript and HTML.

Hopefully it is easy to understand the code.

The most complicated part is scale and translate the coordinate systems. Also complicated is making the rainbow palette.

function mandel(x,y) {
  var a=0; var b=0;
  for (i = 0; i<250; ++i) {
    // Complex z = z^2 + c
    var t = a*a - b*b;
    b = 2*a*b;
    a = t;
    a = a + x;
    b = b + y;
    var m = a*a + b*b;
    if (m > 10)  return i;
  }
  return 250;
}

enter image description here

Android SQLite Example

The DBHelper class is what handles the opening and closing of sqlite databases as well sa creation and updating, and a decent article on how it all works is here. When I started android it was very useful (however I've been objective-c lately, and forgotten most of it to be any use.

append new row to old csv file python

# I like using the codecs opening in a with 
field_names = ['latitude', 'longitude', 'date', 'user', 'text']
with codecs.open(filename,"ab", encoding='utf-8') as logfile:
    logger = csv.DictWriter(logfile, fieldnames=field_names)
    logger.writeheader()

# some more code stuff 

    for video in aList:
        video_result = {}                                     
        video_result['date'] = video['snippet']['publishedAt']
        video_result['user'] = video['id']
        video_result['text'] = video['snippet']['description'].encode('utf8')
        logger.writerow(video_result) 

Convert javascript object or array to json for ajax data

I'm not entirely sure but I think you are probably surprised at how arrays are serialized in JSON. Let's isolate the problem. Consider following code:

var display = Array();
display[0] = "none";
display[1] = "block";
display[2] = "none";

console.log( JSON.stringify(display) );

This will print:

["none","block","none"]

This is how JSON actually serializes array. However what you want to see is something like:

{"0":"none","1":"block","2":"none"}

To get this format you want to serialize object, not array. So let's rewrite above code like this:

var display2 = {};
display2["0"] = "none";
display2["1"] = "block";
display2["2"] = "none";

console.log( JSON.stringify(display2) );

This will print in the format you want.

You can play around with this here: http://jsbin.com/oDuhINAG/1/edit?js,console

Firing events on CSS class changes in jQuery

If you want to detect class change, best way is to use Mutation Observers, which gives you complete control over any attribute change. However you need to define listener yourself, and append it to element you are listening. Good thing is that you don't need to trigger anything manually once listener is appended.

$(function() {
(function($) {
    var MutationObserver = window.MutationObserver || window.WebKitMutationObserver || window.MozMutationObserver;

    $.fn.attrchange = function(callback) {
        if (MutationObserver) {
            var options = {
                subtree: false,
                attributes: true
            };

            var observer = new MutationObserver(function(mutations) {
                mutations.forEach(function(e) {
                    callback.call(e.target, e.attributeName);
                });
            });

            return this.each(function() {
                observer.observe(this, options);
            });

        }
    }
})(jQuery);

//Now you need to append event listener
$('body *').attrchange(function(attrName) {

    if(attrName=='class'){
            alert('class changed');
    }else if(attrName=='id'){
            alert('id changed');
    }else{
        //OTHER ATTR CHANGED
    }

});
});

In this example event listener is appended to every element, but you don't want that in most cases (save memory). Append this "attrchange" listener to element you want observe.

.NET Global exception handler in console application

I just inherited an old VB.NET console application and needed to set up a Global Exception Handler. Since this question mentions VB.NET a few times and is tagged with VB.NET, but all the other answers here are in C#, I thought I would add the exact syntax for a VB.NET application as well.

Public Sub Main()
    REM Set up Global Unhandled Exception Handler.
    AddHandler System.AppDomain.CurrentDomain.UnhandledException, AddressOf MyUnhandledExceptionEvent

    REM Do other stuff
End Sub

Public Sub MyUnhandledExceptionEvent(ByVal sender As Object, ByVal e As UnhandledExceptionEventArgs)
    REM Log Exception here and do whatever else is needed
End Sub

I used the REM comment marker instead of the single quote here because Stack Overflow seemed to handle the syntax highlighting a bit better with REM.

How can I declare optional function parameters in JavaScript?

Update

With ES6, this is possible in exactly the manner you have described; a detailed description can be found in the documentation.

Old answer

Default parameters in JavaScript can be implemented in mainly two ways:

function myfunc(a, b)
{
    // use this if you specifically want to know if b was passed
    if (b === undefined) {
        // b was not passed
    }
    // use this if you know that a truthy value comparison will be enough
    if (b) {
        // b was passed and has truthy value
    } else {
        // b was not passed or has falsy value
    }
    // use this to set b to a default value (using truthy comparison)
    b = b || "default value";
}

The expression b || "default value" evaluates the value AND existence of b and returns the value of "default value" if b either doesn't exist or is falsy.

Alternative declaration:

function myfunc(a)
{
    var b;

    // use this to determine whether b was passed or not
    if (arguments.length == 1) {
        // b was not passed
    } else {
        b = arguments[1]; // take second argument
    }
}

The special "array" arguments is available inside the function; it contains all the arguments, starting from index 0 to N - 1 (where N is the number of arguments passed).

This is typically used to support an unknown number of optional parameters (of the same type); however, stating the expected arguments is preferred!

Further considerations

Although undefined is not writable since ES5, some browsers are known to not enforce this. There are two alternatives you could use if you're worried about this:

b === void 0;
typeof b === 'undefined'; // also works for undeclared variables

How to read data from excel file using c#

CSharpJExcel for reading Excel 97-2003 files (XLS), ExcelPackage for reading Excel 2007/2010 files (Office Open XML format, XLSX), and ExcelDataReader that seems to have the ability to handle both formats

Good luck!

Avoid dropdown menu close on click inside

Like for instance Bootstrap 4 Alpha has this Menu Event. Why not use?

// PREVENT INSIDE MEGA DROPDOWN
$('.dropdown-menu').on("click.bs.dropdown", function (e) {
    e.stopPropagation();
    e.preventDefault();                
});

How to force reloading php.ini file?

TL;DR; If you're still having trouble after restarting apache or nginx, also try restarting the php-fpm service.

The answers here don't always satisfy the requirement to force a reload of the php.ini file. On numerous occasions I've taken these steps to be rewarded with no update, only to find the solution I need after also restarting the php-fpm service. So if restarting apache or nginx doesn't trigger a php.ini update although you know the files are updated, try restarting php-fpm as well.

To restart the service:

Note: prepend sudo if not root

Using SysV Init scripts directly:

/etc/init.d/php-fpm restart        # typical
/etc/init.d/php5-fpm restart       # debian-style
/etc/init.d/php7.0-fpm restart     # debian-style PHP 7

Using service wrapper script

service php-fpm restart        # typical
service php5-fpm restart       # debian-style
service php7.0-fpm restart.    # debian-style PHP 7

Using Upstart (e.g. ubuntu):

restart php7.0-fpm         # typical (ubuntu is debian-based) PHP 7
restart php5-fpm           # typical (ubuntu is debian-based)
restart php-fpm            # uncommon

Using systemd (newer servers):

systemctl restart php-fpm.service        # typical
systemctl restart php5-fpm.service       # uncommon
systemctl restart php7.0-fpm.service     # uncommon PHP 7

Or whatever the equivalent is on your system.

The above commands taken directly from this server fault answer

PHP: How to remove specific element from an array?

foreach ($get_dept as $key5 => $dept_value) {
                if ($request->role_id == 5 || $request->role_id == 6){
                    array_splice($get_dept, $key5, 1);
                }
            }

How to validate an email address in PHP

After reading the answers here, this is what I ended up with:

public static function isValidEmail(string $email) : bool
{
    if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
        return false;
    }

    //Get host name from email and check if it is valid
    $email_host = array_slice(explode("@", $email), -1)[0];

    // Check if valid IP (v4 or v6). If it is we can't do a DNS lookup
    if (!filter_var($email_host,FILTER_VALIDATE_IP, [
        'flags' => FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE,
    ])) {
        //Add a dot to the end of the host name to make a fully qualified domain name
        // and get last array element because an escaped @ is allowed in the local part (RFC 5322)
        // Then convert to ascii (http://us.php.net/manual/en/function.idn-to-ascii.php)
        $email_host = idn_to_ascii($email_host.'.');

        //Check for MX pointers in DNS (if there are no MX pointers the domain cannot receive emails)
        if (!checkdnsrr($email_host, "MX")) {
            return false;
        }
    }

    return true;
}

Arithmetic overflow error converting numeric to data type numeric

If you want to reduce the size to decimal(7,2) from decimal(9,2) you will have to account for the existing data with values greater to fit into decimal(7,2). Either you will have to delete those numbers are truncate it down to fit into your new size. If there was no data for the field you are trying to update it will do it automatically without issues

How to revert initial git commit?

All what you have to do is to revert the commit.

git revert {commit_id}'

Then push it

git push origin -f

How do you run a single query through mysql from the command line?

echo "select * from users;" | mysql -uroot -p -hslavedb.mydomain.com mydb_production

Adding a caption to an equation in LaTeX

The \caption command is restricted to floats: you will need to place the equation in a figure or table environment (or a new kind of floating environment). For example:

\begin{figure}
\[ E = m c^2 \]
\caption{A famous equation}
\end{figure}

The point of floats is that you let LaTeX determine their placement. If you want to equation to appear in a fixed position, don't use a float. The \captionof command of the caption package can be used to place a caption outside of a floating environment. It is used like this:

\[ E = m c^2 \]
\captionof{figure}{A famous equation}

This will also produce an entry for the \listoffigures, if your document has one.

To align parts of an equation, take a look at the eqnarray environment, or some of the environments of the amsmath package: align, gather, multiline,...

Removing black dots from li and ul

There you go, this is what I used to fix your problem:

CSS CODE

nav ul { list-style-type: none; }

HTML CODE

<nav>
<ul>
<li><a href="#">Milk</a>
   <ul>
   <li><a href="#">Goat</a></li>
   <li><a href="#">Cow</a></li>
   </ul>
</li>
<li><a href="#">Eggs</a>
   <ul>
   <li><a href="#">Free-range</a></li>
   <li><a href="#">Other</a></li>
   </ul>
</li>
<li><a href="#">Cheese</a>
   <ul>
   <li><a href="#">Smelly</a></li>
   <li><a href="#">Extra smelly</a></li>
   </ul>
</li>
</ul>
</nav>

Remove the last character from a string

First, I try without a space, rtrim($arraynama, ","); and get an error result.

Then I add a space and get a good result:

$newarraynama = rtrim($arraynama, ", ");

Is it possible to start activity through adb shell?

eg:

MyPackageName is com.example.demo

MyActivityName is com.example.test.MainActivity

adb shell am start -n com.example.demo/com.example.test.MainActivity

how to query LIST using linq

I would also suggest LinqPad as a convenient way to tackle with Linq for both advanced and beginners.

Example:
enter image description here

How to convert DateTime? to DateTime

DateTime UpdatedTime = _objHotelPackageOrder.HasValue ? _objHotelPackageOrder.UpdatedDate.Value : DateTime.Now;

Center div on the middle of screen

This should work with any div or screen size:

_x000D_
_x000D_
.center-screen {_x000D_
  display: flex;_x000D_
  flex-direction: column;_x000D_
  justify-content: center;_x000D_
  align-items: center;_x000D_
  text-align: center;_x000D_
  min-height: 100vh;_x000D_
}
_x000D_
 <html>_x000D_
 <head>_x000D_
 </head>_x000D_
 <body>_x000D_
 <div class="center-screen">_x000D_
 I'm in the center_x000D_
 </div>_x000D_
 </body>_x000D_
 </html>
_x000D_
_x000D_
_x000D_

See more details about flex here. This should work on most of the browsers, see compatibility matrix here.

Update: If you don't want the scroll bar, make min-height smaller, for example min-height: 95vh;

dropping rows from dataframe based on a "not in" condition

You can use Series.isin:

df = df[~df.datecolumn.isin(a)]

While the error message suggests that all() or any() can be used, they are useful only when you want to reduce the result into a single Boolean value. That is however not what you are trying to do now, which is to test the membership of every values in the Series against the external list, and keep the results intact (i.e., a Boolean Series which will then be used to slice the original DataFrame).

You can read more about this in the Gotchas.

How to check the version of scipy

In [95]: import scipy

In [96]: scipy.__version__
Out[96]: '0.12.0'

In [104]: scipy.version.*version?
scipy.version.full_version
scipy.version.short_version
scipy.version.version

In [105]: scipy.version.full_version
Out[105]: '0.12.0'

In [106]: scipy.version.git_revision
Out[106]: 'cdd6b32233bbecc3e8cbc82531905b74f3ea66eb'

In [107]: scipy.version.release
Out[107]: True

In [108]: scipy.version.short_version
Out[108]: '0.12.0'

In [109]: scipy.version.version
Out[109]: '0.12.0'

See SciPy doveloper documentation for reference.

How to read data From *.CSV file using javascript?

function CSVParse(csvFile)
{
    this.rows = [];

    var fieldRegEx = new RegExp('(?:\s*"((?:""|[^"])*)"\s*|\s*((?:""|[^",\r\n])*(?:""|[^"\s,\r\n]))?\s*)(,|[\r\n]+|$)', "g");   
    var row = [];
    var currMatch = null;

    while (currMatch = fieldRegEx.exec(this.csvFile))
    {
        row.push([currMatch[1], currMatch[2]].join('')); // concatenate with potential nulls

        if (currMatch[3] != ',')
        {
            this.rows.push(row);
            row = [];
        }

        if (currMatch[3].length == 0)
            break;
    }
}

I like to have the regex do as much as possible. This regex treats all items as either quoted or unquoted, followed by either a column delimiter, or a row delimiter. Or the end of text.

Which is why that last condition -- without it it would be an infinite loop since the pattern can match a zero length field (totally valid in csv). But since $ is a zero length assertion, it won't progress to a non match and end the loop.

And FYI, I had to make the second alternative exclude quotes surrounding the value; seems like it was executing before the first alternative on my javascript engine and considering the quotes as part of the unquoted value. I won't ask -- just got it to work.

How can I add spaces between two <input> lines using CSS?

You don't need to wrap everything in a DIV to achieve basic styling on inputs.

input[type="text"] {margin: 0 0 10px 0;}

will do the trick in most cases.

Semantically, one <br/> tag is okay between elements to position them. When you find yourself using multiple <br/>'s (which are semantic elements) to achieve cosmetic effects, that's a flag that you're mixing responsibilities, and you should consider getting back to basics.

Detect all changes to a <input type="text"> (immediately) using JQuery

Unfortunately, I think setInterval wins the prize:

<input type=text id=input_id />
<script>
setInterval(function() { ObserveInputValue($('#input_id').val()); }, 100);
</script>

It's the cleanest solution, at only 1 line of code. It's also the most robust, since you don't have to worry about all the different events/ways an input can get a value.

The downsides of using 'setInterval' don't seem to apply in this case:

  • The 100ms latency? For many applications, 100ms is fast enough.
  • Added load on the browser? In general, adding lots of heavy-weight setIntervals on your page is bad. But in this particular case, the added page load is undetectable.
  • It doesn't scale to many inputs? Most pages don't have more than a handful of inputs, which you can sniff all in the same setInterval.

Iterating through array - java

You can import the lib org.apache.commons.lang.ArrayUtils

There is a static method where you can pass in an int array and a value to check for.

contains(int[] array, int valueToFind) Checks if the value is in the given array.

ArrayUtils.contains(intArray, valueToFind);

ArrayUtils API

How to increase dbms_output buffer?

You can Enable DBMS_OUTPUT and set the buffer size. The buffer size can be between 1 and 1,000,000.

dbms_output.enable(buffer_size IN INTEGER DEFAULT 20000);
exec dbms_output.enable(1000000);

Check this

EDIT

As per the comment posted by Frank and Mat, you can also enable it with Null

exec dbms_output.enable(NULL);

buffer_size : Upper limit, in bytes, the amount of buffered information. Setting buffer_size to NULL specifies that there should be no limit. The maximum size is 1,000,000, and the minimum is 2,000 when the user specifies buffer_size (NOT NULL).

How to define unidirectional OneToMany relationship in JPA

My bible for JPA work is the Java Persistence wikibook. It has a section on unidirectional OneToMany which explains how to do this with a @JoinColumn annotation. In your case, i think you would want:

@OneToMany
@JoinColumn(name="TXTHEAD_CODE")
private Set<Text> text;

I've used a Set rather than a List, because the data itself is not ordered.

The above is using a defaulted referencedColumnName, unlike the example in the wikibook. If that doesn't work, try an explicit one:

@OneToMany
@JoinColumn(name="TXTHEAD_CODE", referencedColumnName="DATREG_META_CODE")
private Set<Text> text;

How do I set a path in Visual Studio?

Set the PATH variable, like you're doing. If you're running the program from the IDE, you can modify environment variables by adjusting the Debugging options in the project properties.

If the DLLs are named such that you don't need different paths for the different configuration types, you can add the path to the system PATH variable or to Visual Studio's global one in Tools | Options.

How do I convert a Swift Array to a String?

let arrayTemp :[String] = ["Mani","Singh","iOS Developer"]
    let stringAfterCombining = arrayTemp.componentsJoinedByString(" ")
   print("Result will be >>>  \(stringAfterCombining)")

Result will be >>> Mani Singh iOS Developer

How to get first element in a list of tuples?

when I ran (as suggested above):

>>> a = [(1, u'abc'), (2, u'def')]
>>> import operator
>>> b = map(operator.itemgetter(0), a)
>>> b

instead of returning:

[1, 2]

I received this as the return:

<map at 0xb387eb8>

I found I had to use list():

>>> b = list(map(operator.itemgetter(0), a))

to successfully return a list using this suggestion. That said, I'm happy with this solution, thanks. (tested/run using Spyder, iPython console, Python v3.6)

Can't subtract offset-naive and offset-aware datetimes

I've found timezone.make_aware(datetime.datetime.now()) is helpful in django (I'm on 1.9.1). Unfortunately you can't simply make a datetime object offset-aware, then timetz() it. You have to make a datetime and make comparisons based on that.

Getting a list of all subdirectories in the current directory

This will list all subdirectories right down the file tree.

import pathlib


def list_dir(dir):
    path = pathlib.Path(dir)
    dir = []
    try:
        for item in path.iterdir():
            if item.is_dir():
                dir.append(item)
                dir = dir + list_dir(item)
        return dir
    except FileNotFoundError:
        print('Invalid directory')

pathlib is new in version 3.4

Error: org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'text/plain;charset=UTF-8' not supported

Ok - for me the source of the problem was in serialisation/deserialisation. The object that was being sent and received was as follows where the code is submitted and the code and maskedPhoneNumber is returned.

@ApiObject(description = "What the object is for.")
@JsonIgnoreProperties(ignoreUnknown = true)
public class CodeVerification {

    @ApiObjectField(description = "The code which is to be verified.")
    @NotBlank(message = "mandatory")
    private final String code;

    @ApiObjectField(description = "The masked mobile phone number to which the code was verfied against.")
    private final String maskedMobileNumber;

    public codeVerification(@JsonProperty("code") String code, String maskedMobileNumber) {
        this.code = code;
        this.maskedMobileNumber = maskedMobileNumber;
    }

    public String getcode() {
        return code;
    }

    public String getMaskedMobileNumber() {
        return maskedMobileNumber;
    }
}

The problem was that I didn't have a JsonProperty defined for the maskedMobileNumber in the constructor. i.e. Constructor should have been

public codeVerification(@JsonProperty("code") String code, @JsonProperty("maskedMobileNumber") String maskedMobileNumber) {
    this.code = code;
    this.maskedMobileNumber = maskedMobileNumber;
}

error MSB6006: "cmd.exe" exited with code 1

Simple and better solution : %WINDIR%\Microsoft.NET\Framework\v4.0.30319\MSBuild.exe MyProject.sln I make a bat file like this %WINDIR%\Microsoft.NET\Framework\v4.0.30319\MSBuild.exe D:\GESTION-SOMECOPA\GestionCommercial\GestionCommercial.sln pause

Then I can see all errors and correct them. Because when you change the folder name (without spaces as seen above) you will have another problems. Visual Studio 2015 works fine after this.

How to extract text from a string using sed?

The pattern \d might not be supported by your sed. Try [0-9] or [[:digit:]] instead.

To only print the actual match (not the entire matching line), use a substitution.

sed -n 's/.*\([0-9][0-9]*G[0-9][0-9]*\).*/\1/p'

What __init__ and self do in Python?

# Source: Class and Instance Variables
# https://docs.python.org/2/tutorial/classes.html#class-and-instance-variables

class MyClass(object):
    # class variable
    my_CLS_var = 10

    # sets "init'ial" state to objects/instances, use self argument
    def __init__(self):
        # self usage => instance variable (per object)
        self.my_OBJ_var = 15

        # also possible, class name is used => init class variable
        MyClass.my_CLS_var = 20


def run_example_func():
    # PRINTS    10    (class variable)
    print MyClass.my_CLS_var

    # executes __init__ for obj1 instance
    # NOTE: __init__ changes class variable above
    obj1 = MyClass()

    # PRINTS    15    (instance variable)
    print obj1.my_OBJ_var

    # PRINTS    20    (class variable, changed value)
    print MyClass.my_CLS_var


run_example_func()

EF LINQ include multiple and nested entities

Have you tried just adding another Include:

Course course = db.Courses
                .Include(i => i.Modules.Select(s => s.Chapters))
                .Include(i => i.Lab)
                .Single(x => x.Id == id);

Your solution fails because Include doesn't take a boolean operator

Include(i => i.Modules.Select(s => s.Chapters) &&          i.Lab)
                           ^^^                  ^             ^ 
                          list           bool operator    other list

Update To learn more, download LinqPad and look through the samples. I think it is the quickest way to get familiar with Linq and Lambda.

As a start - the difference between Select and Include is that that with a Select you decide what you want to return (aka projection). The Include is a Eager Loading function, that tells Entity Framework that you want it to include data from other tables.

The Include syntax can also be in string. Like this:

           db.Courses
            .Include("Module.Chapter")
            .Include("Lab")
            .Single(x => x.Id == id);

But the samples in LinqPad explains this better.

How to schedule a periodic task in Java?

Try this way ->

Firstly create a class TimeTask that run your task, it looks like:

public class CustomTask extends TimerTask  {

   public CustomTask(){

     //Constructor

   }

   public void run() {
       try {

         // Your task process

       } catch (Exception ex) {
           System.out.println("error running thread " + ex.getMessage());
       }
    }
}

then in main class you instantiate the task and run it periodically started by a specified date:

 public void runTask() {

        Calendar calendar = Calendar.getInstance();
        calendar.set(
           Calendar.DAY_OF_WEEK,
           Calendar.MONDAY
        );
        calendar.set(Calendar.HOUR_OF_DAY, 15);
        calendar.set(Calendar.MINUTE, 40);
        calendar.set(Calendar.SECOND, 0);
        calendar.set(Calendar.MILLISECOND, 0);



        Timer time = new Timer(); // Instantiate Timer Object

        // Start running the task on Monday at 15:40:00, period is set to 8 hours
        // if you want to run the task immediately, set the 2nd parameter to 0
        time.schedule(new CustomTask(), calendar.getTime(), TimeUnit.HOURS.toMillis(8));
}

How can I remove the decimal part from JavaScript number?

If you don't care about rouding, just convert the number to a string, then remove everything after the period including the period. This works whether there is a decimal or not.

const sEpoch = ((+new Date()) / 1000).toString();
const formattedEpoch = sEpoch.split('.')[0];

How to show another window from mainwindow in QT

  1. Implement a slot in your QMainWindow where you will open your new Window,
  2. Place a widget on your QMainWindow,
  3. Connect a signal from this widget to a slot from the QMainWindow (for example: if the widget is a QPushButton connect the signal click() to the QMainWindow custom slot you have created).

Code example:

MainWindow.h

// ...
include "newwindow.h"
// ...
public slots:
   void openNewWindow();
// ...
private:
   NewWindow *mMyNewWindow;
// ...
}

MainWindow.cpp

// ...
   MainWindow::MainWindow()
   {
      // ...
      connect(mMyButton, SIGNAL(click()), this, SLOT(openNewWindow()));
      // ...
   }
// ...
void MainWindow::openNewWindow()
{
   mMyNewWindow = new NewWindow(); // Be sure to destroy your window somewhere
   mMyNewWindow->show();
   // ...
}

This is an example on how display a custom new window. There are a lot of ways to do this.

Sequence contains more than one element

As @Mehmet is pointing out, if your result is returning more then 1 elerment then you need to look into you data as i suspect that its not by design that you have customers sharing a customernumber.

But to the point i wanted to give you a quick overview.

//success on 0 or 1 in the list, returns dafault() of whats in the list if 0
list.SingleOrDefault();
//success on 1 and only 1 in the list
list.Single();

//success on 0-n, returns first element in the list or default() if 0 
list.FirstOrDefault();
//success 1-n, returns the first element in the list
list.First();

//success on 0-n, returns first element in the list or default() if 0 
list.LastOrDefault();
//success 1-n, returns the last element in the list
list.Last();

for more Linq expressions have a look at System.Linq.Expressions

How can I Insert data into SQL Server using VBNet

Function ExtSql(ByVal sql As String) As Boolean
    Dim cnn As SqlConnection
    Dim cmd As SqlCommand
    cnn = New SqlConnection(My.Settings.mySqlConnectionString)
    Try
        cnn.Open()
        cmd = New SqlCommand
        cmd.Connection = cnn
        cmd.CommandType = CommandType.Text
        cmd.CommandText = sql
        cmd.ExecuteNonQuery()
        cnn.Close()
        cmd.Dispose()
    Catch ex As Exception
        cnn.Close()
        Return False
    End Try
    Return True
End Function

Django MEDIA_URL and MEDIA_ROOT

Here are the changes I had to make to deliver PDFs for the django-publications app, using Django 1.10.6:

Used the same definitions for media directories as you, in settings.py:

MEDIA_ROOT = '/home/user/mysite/media/'

MEDIA_URL = '/media/'

As provided by @thisisashwanipandey, in the project's main urls.py:

from django.conf import settings
from django.conf.urls.static import static

urlpatterns = [
    # ... the rest of your URLconf goes here ...
] + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

and a modification of the answer provided by @r-allela, in settings.py:

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [os.path.join(BASE_DIR, 'templates')],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                # ... the rest of your context_processors goes here ...
                'django.template.context_processors.media',
            ],
         },
    },
]

Change background position with jQuery

rebellion's answer above won't actually work, because to CSS, 'background-position' is actually shorthand for 'background-position-x' and 'background-position-y' so the correct version of his code would be:

$(document).ready(function(){
    $('#submenu li').hover(function(){
        $('#carousel').css('background-position-x', newValueX);
        $('#carousel').css('background-position-y', newValue);
    }, function(){
        $('#carousel').css('background-position-x', oldValueX);
        $('#carousel').css('background-position-y', oldValueY);
    });
});

It took about 4 hours of banging my head against it to come to that aggravating realization.

How do I use ROW_NUMBER()?

Though I agree with others that you could use count() to get the total number of rows, here is how you can use the row_count():

  1. To get the total no of rows:

    with temp as (
        select row_number() over (order by id) as rownum
        from table_name 
    )
    select max(rownum) from temp
  2. To get the row numbers where name is Matt:

    with temp as (
        select name, row_number() over (order by id) as rownum
        from table_name
    )
    select rownum from temp where name like 'Matt'

You can further use min(rownum) or max(rownum) to get the first or last row for Matt respectively.

These were very simple implementations of row_number(). You can use it for more complex grouping. Check out my response on Advanced grouping without using a sub query

List of lists into numpy array

>>> numpy.array([[1, 2], [3, 4]]) 
array([[1, 2], [3, 4]])

How to install JRE 1.7 on Mac OS X and use it with Eclipse?

You need to tell Eclipse which JDK/JRE's you have installed and where they are located.

This is somewhat burried in the Eclipse preferences: In the Window-Menu select "Preferences". In the Preferences Tree, open the Node "Java" and select "Installed JRE's". Then click on the "Add"-Button in the Panel and select "Standard VM", "Next" and for "JRE Home" click on the "Directory"-Button and select the top level folder of the JDK you want to add.

Its easier than the description may make it look.

Read and write a String from text file

For my txt file works this way:

let myFileURL = NSBundle.mainBundle().URLForResource("listacomuni", withExtension: "txt")!
let myText = try! String(contentsOfURL: myFileURL, encoding: NSISOLatin1StringEncoding)
print(String(myText))

Connect with SSH through a proxy

Here's how to do Richard Christensen's answer as a one-liner, no file editing required (replace capitalized with your own settings, PROXYPORT is frequently 80):

 ssh USER@FINAL_DEST -o "ProxyCommand=nc -X connect -x PROXYHOST:PROXYPORT %h %p"

You can use the same -o ... option for scp as well, see https://superuser.com/a/752621/39364

If you get this in OS X:

 nc: invalid option -- X
 Try `nc --help' for more information.

it may be that you're accidentally using the homebrew version of netcat (you can see by doing a which -a nc command--/usr/bin/nc should be listed first). If there are two then one workaround is to specify the full path to the nc you want, like ProxyCommand=/usr/bin/nc ...

For CentOS nc has the same problem of invalid option --X. connect-proxy is an alternative, easy to install using yum and works --

ssh -o ProxyCommand="connect-proxy -S PROXYHOST:PROXYPORT %h %p" USER@FINAL_DEST

How do I add 1 day to an NSDate?

NSDate *now = [NSDate date];
int daysToAdd = 1;
NSDate *tomorrowDate = [now dateByAddingTimeInterval:60*60*24*daysToAdd];

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"EEEE, dd MMM yyyy"];
NSLog(@"%@", [dateFormatter stringFromDate:tomorrowDate]);

What's the best way to select the minimum value from several columns?

You can use the "brute force" approach with a twist:

SELECT CASE
    WHEN Col1 <= Col2 AND Col1 <= Col3 THEN Col1
    WHEN                  Col2 <= Col3 THEN Col2
    ELSE                                    Col3
END AS [Min Value] FROM [Your Table]

When the first when condition fails it guarantees that Col1 is not the smallest value therefore you can eliminate it from rest of the conditions. Likewise for subsequent conditions. For five columns your query becomes:

SELECT CASE
    WHEN Col1 <= Col2 AND Col1 <= Col3 AND Col1 <= Col4 AND Col1 <= Col5 THEN Col1
    WHEN                  Col2 <= Col3 AND Col2 <= Col4 AND Col2 <= Col5 THEN Col2
    WHEN                                   Col3 <= Col4 AND Col3 <= Col5 THEN Col3
    WHEN                                                    Col4 <= Col5 THEN Col4
    ELSE                                                                      Col5
END AS [Min Value] FROM [Your Table]

Note that if there is a tie between two or more columns then <= ensures that we exit the CASE statement as early as possible.

How can I load Partial view inside the view?

For me this worked after I downloaded AJAX Unobtrusive library via NuGet :

 Search and install via NuGet Packages:   Microsoft.jQuery.Unobtrusive.Ajax

Than add in the view the references to jquery and AJAX Unobtrusive:

@Scripts.Render("~/bundles/jquery")
<script src="~/Scripts/jquery.unobtrusive-ajax.min.js"> </script>

Next the Ajax ActionLink and the div were we want to render the results:

@Ajax.ActionLink(
    "Click Here to Load the Partial View", 
    "ActionName", 
    null, 
    new AjaxOptions { UpdateTargetId = "toUpdate" }
)

<div id="toUpdate"></div>

Update Item to Revision vs Revert to Revision

Update your working copy to the selected revision. Useful if you want to have your working copy reflect a time in the past, or if there have been further commits to the repository and you want to update your working copy one step at a time. It is best to update a whole directory in your working copy, not just one file, otherwise your working copy could be inconsistent. This is used to test a specific rev purpose, if your test has done, you can use this command to test another rev or use SVN Update to get HEAD

If you want to undo an earlier change permanently, use Revert to this revision instead.

-- from TSVN help doc

If you Update your working copy to an earlier rev, this is only affect your own working copy, after you do some change, and want to commit, you will fail,TSVN will alert you to update your WC to latest revision first If you Revert to a rev, you can commit to repository.everyone will back to the rev after they do an update.

malloc for struct and pointer in C

In principle you're doing it correct already. For what you want you do need two malloc()s.

Just some comments:

struct Vector y = (struct Vector*)malloc(sizeof(struct Vector));
y->x = (double*)malloc(10*sizeof(double));

should be

struct Vector *y = malloc(sizeof *y); /* Note the pointer */
y->x = calloc(10, sizeof *y->x);

In the first line, you allocate memory for a Vector object. malloc() returns a pointer to the allocated memory, so y must be a Vector pointer. In the second line you allocate memory for an array of 10 doubles.

In C you don't need the explicit casts, and writing sizeof *y instead of sizeof(struct Vector) is better for type safety, and besides, it saves on typing.

You can rearrange your struct and do a single malloc() like so:

struct Vector{    
    int n;
    double x[];
};
struct Vector *y = malloc(sizeof *y + 10 * sizeof(double));

Delete statement in SQL is very slow

I read this article it was really helpful for troubleshooting any kind of inconveniences

https://support.microsoft.com/en-us/kb/224453

this is a case of waitresource KEY: 16:72057595075231744 (ab74b4daaf17)

-- First SQL Provider to find the SPID (Session ID)

-- Second Identify problem, check Status, Open_tran, Lastwaittype, waittype, and waittime
-- iMPORTANT Waitresource select * from sys.sysprocesses where spid = 57

select * from sys.databases where database_id=16

-- with Waitresource check this to obtain object id 
select * from sys.partitions where hobt_id=72057595075231744

select * from sys.objects where object_id=2105058535

getting error HTTP Status 405 - HTTP method GET is not supported by this URL but not used `get` ever?

The problem is that you mapped your servlet to /register.html and it expects POST method, because you implemented only doPost() method. So when you open register.html page, it will not open html page with the form but servlet that handles the form data.

Alternatively when you submit POST form to non-existing URL, web container will display 405 error (method not allowed) instead of 404 (not found).

To fix:

<servlet-mapping>
    <servlet-name>Register</servlet-name>
    <url-pattern>/Register</url-pattern>
</servlet-mapping>

Pandas (python): How to add column to dataframe for index?

How about:

df['new_col'] = range(1, len(df) + 1)

Alternatively if you want the index to be the ranks and store the original index as a column:

df = df.reset_index()

How to Animate Addition or Removal of Android ListView Rows

I have done something similar to this. One approach is to interpolate over the animation time the height of the view over time inside the rows onMeasure while issuing requestLayout() for the listView. Yes it may be be better to do inside the listView code directly but it was a quick solution (that looked good!)

The object 'DF__*' is dependent on column '*' - Changing int to double

Try this:

Remove the constraint DF_Movies_Rating__48CFD27E before changing your field type.

The constraint is typically created automatically by the DBMS (SQL Server).

To see the constraint associated with the table, expand the table attributes in Object explorer, followed by the category Constraints as shown below:

Tree of your table

You must remove the constraint before changing the field type.

Differences between git pull origin master & git pull origin/master

git pull = git fetch + git merge origin/branch

git pull and git pull origin branch only differ in that the latter will only "update" origin/branch and not all origin/* as git pull does.

git pull origin/branch will just not work because it's trying to do a git fetch origin/branch which is invalid.

Question related: git fetch + git merge origin/master vs git pull origin/master

How can I fill a column with random numbers in SQL? I get the same value in every row

Instead of rand(), use newid(), which is recalculated for each row in the result. The usual way is to use the modulo of the checksum. Note that checksum(newid()) can produce -2,147,483,648 and cause integer overflow on abs(), so we need to use modulo on the checksum return value before converting it to absolute value.

UPDATE CattleProds
SET    SheepTherapy = abs(checksum(NewId()) % 10000)
WHERE  SheepTherapy IS NULL

This generates a random number between 0 and 9999.

How to split a delimited string in Ruby and convert it to an array?

"1,2,3,4".split(",") as strings

"1,2,3,4".split(",").map { |s| s.to_i } as integers

Intellij idea cannot resolve anything in maven

In IntelliJ 12.1.4 I went through Settings --> Maven --> Importing and made sure the following was selected:

  1. Import Maven projects automatically
  2. Create IDEA modules for aggregator projects
  3. Keep source...
  4. Exclude build dir...
  5. Use Maven output...
  6. Generated souces folders: "detect automatically"
  7. Phase to be...: "process-resources"
  8. Automatically download: "sources" & "documentation"
  9. Use Maven3 to import project
    • VM options for importer: -Xmx512m

This took me from having a lot of unresolved import statements to having everything resolved. I think the key here was using Maven3 to import project... Hopefully this helps.

Deleting all files from a folder using PHP?

This code from http://php.net/unlink:

/**
 * Delete a file or recursively delete a directory
 *
 * @param string $str Path to file or directory
 */
function recursiveDelete($str) {
    if (is_file($str)) {
        return @unlink($str);
    }
    elseif (is_dir($str)) {
        $scan = glob(rtrim($str,'/').'/*');
        foreach($scan as $index=>$path) {
            recursiveDelete($path);
        }
        return @rmdir($str);
    }
}

What is the most efficient/elegant way to parse a flat table into a tree?

To Extend Bill's SQL solution you can basically do the same using a flat array. Further more if your strings all have the same lenght and your maximum number of children are known (say in a binary tree) you can do it using a single string (character array). If you have arbitrary number of children this complicates things a bit... I would have to check my old notes to see what can be done.

Then, sacrificing a bit of memory, especially if your tree is sparse and/or unballanced, you can, with a bit of index math, access all the strings randomly by storing your tree, width first in the array like so (for a binary tree):

String[] nodeArray = [L0root, L1child1, L1child2, L2Child1, L2Child2, L2Child3, L2Child4] ...

yo know your string length, you know it

I'm at work now so cannot spend much time on it but with interest I can fetch a bit of code to do this.

We use to do it to search in binary trees made of DNA codons, a process built the tree, then we flattened it to search text patterns and when found, though index math (revers from above) we get the node back... very fast and efficient, tough our tree rarely had empty nodes, but we could searh gigabytes of data in a jiffy.

Removing duplicate rows in Notepad++

If you don't care about row order (which I don't think you do), then you can use a Linux/FreeBSD/Mac OS X/Cygwin box and do:

$ cat yourfile | sort | uniq > yourfile_nodups

Then open the file again in Notepad++.

Sql query to insert datetime in SQL Server

No need to use convert. Simply list it as a quoted date in ISO 8601 format.
Like so:

select * from table1 where somedate between '2000/01/01' and '2099/12/31'

The separator needs to be a / and it needs to be surrounded by single ' quotes.

Options for HTML scraping?

'Simple HTML DOM Parser' is a good option for PHP, if your familiar with jQuery or JavaScript selectors then you will find yourself at home.

Find it here

There is also a blog post about it here.