Programs & Examples On #Language comparisons

Questions comparing two or more programming or markup languages against each other.

equivalent of vbCrLf in c#

You are looking for System.Environment.NewLine.

On Windows, this is equivalent to \r\n though it could be different under another .NET implementation, such as Mono on Linux, for example.

Is there a Python equivalent to Ruby's string interpolation?

import inspect
def s(template, **kwargs):
    "Usage: s(string, **locals())"
    if not kwargs:
        frame = inspect.currentframe()
        try:
            kwargs = frame.f_back.f_locals
        finally:
            del frame
        if not kwargs:
            kwargs = globals()
    return template.format(**kwargs)

Usage:

a = 123
s('{a}', locals()) # print '123'
s('{a}') # it is equal to the above statement: print '123'
s('{b}') # raise an KeyError: b variable not found

PS: performance may be a problem. This is useful for local scripts, not for production logs.

Duplicated:

What is C# equivalent of <map> in C++?

The equivalent would be class SortedDictionary<TKey, TValue> in the System.Collections.Generic namespace.

If you don't care about the order the class Dictionary<TKey, TValue> in the System.Collections.Generic namespace would probably be sufficient.

XSLT equivalent for JSON

XSLT equivalents for JSON - a list of candidates (tools and specs)

Tools

1. XSLT

You can use XSLT for JSON with the aim of fn:json-to-xml.

This section describes facilities allowing JSON data to be processed using XSLT.

2. jq

jq is like sed for JSON data - you can use it to slice and filter and map and transform structured data with the same ease that sed, awk, grep and friends let you play with text. There are install packages for different OS.

3. jj

JJ is a command line utility that provides a fast and simple way to retrieve or update values from JSON documents. It's powered by GJSON and SJSON under the hood.

4. fx

Command-line JSON processing tool - Don't need to learn new syntax - Plain JavaScript - Formatting and highlighting - Standalone binary

5. jl

jl ("JSON lambda") is a tiny functional language for querying and manipulating JSON.

6. JOLT

JSON to JSON transformation library written in Java where the "specification" for the transform is itself a JSON document.

7. gron

Make JSON greppable! gron transforms JSON into discrete assignments to make it easier to grep for what you want and see the absolute 'path' to it. It eases the exploration of APIs that return large blobs of JSON but have terrible documentation.

8. json-e

JSON-e is a data-structure parameterization system for embedding context in JSON objects. The central idea is to treat a data structure as a "template" and transform it, using another data structure as context, to produce an output data structure.

9. JSLT

JSLT is a complete query and transformation language for JSON. The language design is inspired by jq, XPath, and XQuery.

10. JSONata

JSONata is a lightweight query and transformation language for JSON data. Inspired by the 'location path' semantics of XPath 3.1, it allows sophisticated queries to be expressed in a compact and intuitive notation.

11. JSONPath Plus

Analyse, transform, and selectively extract data from JSON documents (and JavaScript objects). jsonpath-plus expands on the original specification to add some additional operators and makes explicit some behaviors the original did not spell out.

12. json-transforms Last Commit Dec 1, 2017

Provides a recursive, pattern-matching approach to transforming JSON data. Transformations are defined as a set of rules which match the structure of a JSON object. When a match occurs, the rule emits the transformed data, optionally recursing to transform child objects.

13. json Last commit Jun 23, 2018

json is a fast CLI tool for working with JSON. It is a single-file node.js script with no external deps (other than node.js itself).

14. jsawk Last commit Mar 4, 2015

Jsawk is like awk, but for JSON. You work with an array of JSON objects read from stdin, filter them using JavaScript to produce a results array that is printed to stdout.

15. yate Last Commit Mar 13, 2017

Tests can be used as docu https://github.com/pasaran/yate/tree/master/tests

16. jsonpath-object-transform Last Commit Jan 18, 2017

Pulls data from an object literal using JSONPath and generate a new objects based on a template.

17. Stapling Last Commit Sep 16, 2013

Stapling is a JavaScript library that enables XSLT formatting for JSON objects. Instead of using a JavaScript templating engine and text/html templates, Stapling gives you the opportunity to use XSLT templates - loaded asynchronously with Ajax and then cached client side - to parse your JSON datasources.

Specs:

JSON Pointer defines a string syntax for identifying a specific value within a JavaScript Object Notation (JSON) document.

JSONPath expressions always refer to a JSON structure in the same way as XPath expression are used in combination with an XML document

JSPath for JSON is like XPath for XML."

The main source of inspiration behind JSONiq is XQuery, which has been proven so far a successful and productive query language for semi-structured data

Python: Assign Value if None Exists

IfLoop's answer (and MatToufoutu's comment) work great for standalone variables, but I wanted to provide an answer for anyone trying to do something similar for individual entries in lists, tuples, or dictionaries.

Dictionaries

existing_dict = {"spam": 1, "eggs": 2}
existing_dict["foo"] = existing_dict["foo"] if "foo" in existing_dict else 3

Returns {"spam": 1, "eggs": 2, "foo": 3}

Lists

existing_list = ["spam","eggs"]
existing_list = existing_list if len(existing_list)==3 else 
                existing_list + ["foo"]

Returns ["spam", "eggs", "foo"]

Tuples

existing_tuple = ("spam","eggs")
existing_tuple = existing_tuple if len(existing_tuple)==3 else 
                 existing_tuple + ("foo",)

Returns ("spam", "eggs", "foo")

(Don't forget the comma in ("foo",) to define a "single" tuple.)

The lists and tuples solution will be more complicated if you want to do more than just check for length and append to the end. Nonetheless, this gives a flavor of what you can do.

Scala vs. Groovy vs. Clojure

I never had time to play with clojure. But for scala vs groovy, this is words from James Strachan - Groovy creator

"Though my tip though for the long term replacement of javac is Scala. I'm very impressed with it! I can honestly say if someone had shown me the Programming in Scala book by Martin Odersky, Lex Spoon & Bill Venners back in 2003 I'd probably have never created Groovy."

You can read the whole story here

How can I get new selection in "select" in Angular 2?

Another option is to store the object in value as a string:

<select [ngModel]="selectedDevice | json" (ngModelChange)="onChange($event)">
    <option [value]="i | json" *ngFor="let i of devices">{{i}}</option>
</select>

component:

onChange(val) {
    this.selectedDevice = JSON.parse(val);
}

This was the only way I could get two way binding working to set the select value on page load. This was because my list that populates the select box was not the exact same object as my select was bound to and it needs to be the same object, not just same property values.

Laravel 5 Application Key

For me the problem was in that I had not yet ran composer update for this new project/fork. The command failed silently, nothing happened.

After running composer update it worked.

How do I handle too long index names in a Ruby on Rails ActiveRecord migration?

create_table :you_table_name do |t| t.references :studant, index: { name: 'name_for_studant_index' } t.references :teacher, index: { name: 'name_for_teacher_index' } end

Getting String value from enum in Java

if status is of type Status enum, status.name() will give you its defined name.

How to find integer array size in java

The length of an array is available as

int l = array.length;

The size of a List is availabe as

int s = list.size();

Typescript es6 import module "File is not a module error"

Above answers are correct. But just in case... Got same error in VS Code. Had to re-save/recompile file that was throwing error.

Assert a function/method was not called using Mock

Though an old question, I would like to add that currently mock library (backport of unittest.mock) supports assert_not_called method.

Just upgrade yours;

pip install mock --upgrade

Validating file types by regular expression

You can embed case insensitity into the regular expression like so:

\.(?i:)(?:jpg|gif|doc|pdf)$

C# : Passing a Generic Object

It doesn't compile because T could be anything, and not everything will have the myvar field.

You could make myvar a property on ITest:

public ITest
{
    string myvar{get;}
}

and implement it on the classes as a property:

public class MyClass1 : ITest
{
    public string myvar{ get { return "hello 1"; } }
}

and then put a generic constraint on your method:

public void PrintGeneric<T>(T test) where T : ITest
{
    Console.WriteLine("Generic : " + test.myvar);
}

but in that case to be honest you are better off just passing in an ITest:

public void PrintGeneric(ITest test)
{
    Console.WriteLine("Generic : " + test.myvar);
}

PHP shorthand for isset()?

Update for PHP 7 (thanks shock_gone_wild)

PHP 7 introduces the so called null coalescing operator which simplifies the below statements to:

$var = $var ?? "default";

Before PHP 7

No, there is no special operator or special syntax for this. However, you could use the ternary operator:

$var = isset($var) ? $var : "default";

Or like this:

isset($var) ?: $var = 'default';

Remove scroll bar track from ScrollView in Android

try this is your activity onCreate:

ScrollView sView = (ScrollView)findViewById(R.id.deal_web_view_holder);
// Hide the Scollbar
sView.setVerticalScrollBarEnabled(false);
sView.setHorizontalScrollBarEnabled(false);

http://developer.android.com/reference/android/view/View.html#setVerticalScrollBarEnabled%28boolean%29

How do I connect C# with Postgres?

Here is a walkthrough, Using PostgreSQL in your C# (.NET) application (An introduction):

In this article, I would like to show you the basics of using a PostgreSQL database in your .NET application. The reason why I'm doing this is the lack of PostgreSQL articles on CodeProject despite the fact that it is a very good RDBMS. I have used PostgreSQL back in the days when PHP was my main programming language, and I thought.... well, why not use it in my C# application.

Other than that you will need to give us some specific problems that you are having so that we can help diagnose the problem.

How to do a LIKE query with linq?

 where c.FullName.Contains("string")

In Tensorflow, get the names of all the Tensors in a graph

tf.all_variables() can get you the information you want.

Also, this commit made today in TensorFlow Learn that provides a function get_variable_names in estimator that you can use to retrieve all variable names easily.

How to change the Spyder editor background to dark?

I think some of the people answering this question don’t actually try to do what they recommend, because there is something wrong with way the Mac OS version handles the windows.

When you choose the new color scheme and click OK, the preferences window looks like it closed, but it is still there behind the main spyder window. You need to switch windows with command ~ or move the main spyder window to expose the preferences window. Then you need to click Apply to get the new color scheme.

jquery - Check for file extension before uploading

The following code allows to upload gif, png, jpg, jpeg and bmp files.

var extension = $('#your_file_id').val().split('.').pop().toLowerCase();

if($.inArray(extension, ['gif','png','jpg','jpeg','bmp']) == -1) {
    alert('Sorry, invalid extension.');
    return false;
}

Mythical man month 10 lines per developer day - how close on large projects?

I think this comes from from the waterfall development days, where the actual development phase of a project could be as little as 20-30% of the total project time. Take the total lines of code and divide by the entire project time and you'll get around 10 lines/day. Divide by just the coding period, and you'll get closer to what people are quoting.

Django optional url parameters

There are several approaches.

One is to use a non-capturing group in the regex: (?:/(?P<title>[a-zA-Z]+)/)?
Making a Regex Django URL Token Optional

Another, easier to follow way is to have multiple rules that matches your needs, all pointing to the same view.

urlpatterns = patterns('',
    url(r'^project_config/$', views.foo),
    url(r'^project_config/(?P<product>\w+)/$', views.foo),
    url(r'^project_config/(?P<product>\w+)/(?P<project_id>\w+)/$', views.foo),
)

Keep in mind that in your view you'll also need to set a default for the optional URL parameter, or you'll get an error:

def foo(request, optional_parameter=''):
    # Your code goes here

Why was the name 'let' chosen for block-scoped variable declarations in JavaScript?

Adding to exebook's response, the mathematics usage of the keyword let also encapsulates well the scoping implications of let when used in Javascript/ES6. Specifically, just as the following ES6 code is not aware of the assignment in braces of toPrint when it prints out the value of 'Hello World',

let toPrint = 'Hello World.';
{
    let toPrint = 'Goodbye World.';
}
console.log(toPrint); // Prints 'Hello World'

let as used in formalized mathematics (especially the writing of proofs) indicates that the current instance of a variable exists only for the scope of that logical idea. In the following example, x immediately gains a new identity upon entering the new idea (usually these are concepts necessary to prove the main idea) and reverts immediately to the old x upon the conclusion of the sub-proof. Of course, just as in coding, this is considered somewhat confusing and so is usually avoided by choosing a different name for the other variable.

Let x be so and so...

  Proof stuff

 New Idea { Let x be something else ... prove something } Conclude New Idea

 Prove main idea with old x

Binding arrow keys in JS/jQuery

You can check wether an arrow key is pressed by:

$(document).keydown(function(e){
    if (e.keyCode > 36 && e.keyCode < 41) { 
       alert( "arrowkey pressed" );
       return false;
    }
});

How to iterate through a DataTable

foreach (DataRow row in myDataTable.Rows)
{
   Console.WriteLine(row["ImagePath"]);
}

I am writing this from memory.
Hope this gives you enough hint to understand the object model.

DataTable -> DataRowCollection -> DataRow (which one can use & look for column contents for that row, either using columnName or ordinal).

-> = contains.

How to get the host name of the current machine as defined in the Ansible hosts file?

This is an alternative:

- name: Install this only for local dev machine
  pip: name=pyramid
  delegate_to: localhost

MySQL command line client for Windows

If you are looking for tools like the the mysql and mysqldump command line client for Windows for versions around mysql Ver 14.14 Distrib 5.6.13, for Win32 (x86) it seems to be in HOMEDRIVE:\Program Files (x86)\MySQL\MySQL Workbench version

This directory is also not placed in the path by default so you will need to add it to your PATH environment variable before you can easily run it from the command prompt.

Also, there is a mysql utilities console but it does not work for my needs. Below is a list of the capabilities on the mysql utilities console in case it works for you:

Utility           Description
----------------  ---------------------------------------------------------
mysqlauditadmin   audit log maintenance utility
mysqlauditgrep    audit log search utility
mysqldbcompare    compare databases for consistency
mysqldbcopy       copy databases from one server to another
mysqldbexport     export metadata and data from databases
mysqldbimport     import metadata and data from files
mysqldiff         compare object definitions among objects where the
                  difference is how db1.obj1 differs from db2.obj2
mysqldiskusage    show disk usage for databases
mysqlfailover     automatic replication health monitoring and failover
mysqlfrm          show CREATE TABLE from .frm files
mysqlindexcheck   check for duplicate or redundant indexes
mysqlmetagrep     search metadata
mysqlprocgrep     search process information
mysqlreplicate    establish replication with a master
mysqlrpladmin     administration utility for MySQL replication
mysqlrplcheck     check replication
mysqlrplshow      show slaves attached to a master
mysqlserverclone  start another instance of a running server
mysqlserverinfo   show server information
mysqluserclone    clone a MySQL user account to one or more new users

See what's in a stash without applying it

From the man git-stash page:

The modifications stashed away by this command can be listed with git stash list, inspected with git stash show

show [<stash>]
       Show the changes recorded in the stash as a diff between the stashed state and
       its original parent. When no <stash> is given, shows the latest one. By default,
       the command shows the diffstat, but it will accept any format known to git diff
       (e.g., git stash show -p stash@{1} to view the second most recent stash in patch
       form).

To list the stashed modifications

git stash list

To show files changed in the last stash

git stash show

So, to view the content of the most recent stash, run

git stash show -p

To view the content of an arbitrary stash, run something like

git stash show -p stash@{1}

What does the ELIFECYCLE Node.js error mean?

While working on a WordPress theme, I got the same ELIFECYCLE error with slightly different output:

npm ERR! Darwin 14.5.0
npm ERR! argv "/usr/local/Cellar/node/7.6.0/bin/node" "/usr/local/bin/npm" "install"
npm ERR! node v7.6.0
npm ERR! npm  v3.7.3
npm ERR! code ELIFECYCLE
npm ERR! [email protected] postinstall: `bower install && gulp build`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the [email protected] postinstall script 'bower install && gulp build'.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the foundationsix package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     bower install && gulp build

After trying npm install one more time with the same result, I tried bower install. When that was successful I tried gulp build and that also worked.

Everything is working just fine now. No idea why running each command separately worked when && failed but maybe someone else will find this answer useful.

Remove array element based on object property

Based on some comments above below is the code how to remove an object based on a key name and key value

 var items = [ 
  { "id": 3.1, "name": "test 3.1"}, 
  { "id": 22, "name": "test 3.1" }, 
  { "id": 23, "name": "changed test 23" } 
  ]

    function removeByKey(array, params){
      array.some(function(item, index) {
        return (array[index][params.key] === params.value) ? !!(array.splice(index, 1)) : false;
      });
      return array;
    }

    var removed = removeByKey(items, {
      key: 'id',
      value: 23
    });

    console.log(removed);

Getting Database connection in pure JPA setup

The word pure doesn't match to the word hibernate.

EclipseLink

It's somewhat straightforward as described in above link.

  • Note that the EntityManager must be joined to a Transaction or the unwrap method will return null. (Not a good move at all.)
  • I'm not sure the responsibility of closing the connection.
// --------------------------------------------------------- EclipseLink
try {
    final Connection connection = manager.unwrap(Connection.class);
    if (connection != null) { // manage is not in any transaction
        return function.apply(connection);
    }
} catch (final PersistenceException pe) {
    logger.log(FINE, pe, () -> "failed to unwrap as a connection");
}

Hibernate

It should be, basically, done with following codes.

// using vendor specific APIs
final Session session = (Session) manager.unwrap(Session.class);
//return session.doReturningWork<R>(function::apply);
return session.doReturningWork(new ReturningWork<R>() {
    @Override public R execute(final Connection connection) {
        return function.apply(connection);
    }
});

Well, we (at least I) might don't want any vendor-specific dependencies. Proxy comes in rescue.

try {
    // See? You shouldn't fire me, ass hole!!!
    final Class<?> sessionClass
            = Class.forName("org.hibernate.Session");
    final Object session = manager.unwrap(sessionClass);
    final Class<?> returningWorkClass
            = Class.forName("org.hibernate.jdbc.ReturningWork");
    final Method executeMethod
            = returningWorkClass.getMethod("execute", Connection.class);
    final Object workProxy = Proxy.newProxyInstance(
            lookup().lookupClass().getClassLoader(),
            new Class[]{returningWorkClass},
            (proxy, method, args) -> {
                if (method.equals(executeMethod)) {
                    final Connection connection = (Connection) args[0];
                    return function.apply(connection);
                }
                return null;
            });
    final Method doReturningWorkMethod = sessionClass.getMethod(
            "doReturningWork", returningWorkClass);
    return (R) doReturningWorkMethod.invoke(session, workProxy);
} catch (final ReflectiveOperationException roe) {
    logger.log(Level.FINE, roe, () -> "failed to work with hibernate");
}

OpenJPA

I'm not sure OpenJPA already serves a way using unwrap(Connection.class) but can be done with the way described in one of above links.

It's not clear the responsibility of closing the connection. The document (one of above links) seems saying clearly but I'm not good at English.

try {
    final Class<?> k = Class.forName(
            "org.apache.openjpa.persistence.OpenJPAEntityManager");
    if (k.isInstance(manager)) {
        final Method m = k.getMethod("getConnection");
        try {
            try (Connection c = (Connection) m.invoke(manager)) {
                return function.apply(c);
            }
        } catch (final SQLException sqle) {
            logger.log(FINE, sqle, () -> "failed to work with openjpa");
        }
    }
} catch (final ReflectiveOperationException roe) {
    logger.log(Level.FINE, roe, () -> "failed to work with openjpa");
}

How to extract a floating number from a string

Another approach that may be more readable is simple type conversion. I've added a replacement function to cover instances where people may enter European decimals:

>>> for possibility in "Current Level: -13.2 db or 14,2 or 3".split():
...     try:
...         str(float(possibility.replace(',', '.')))
...     except ValueError:
...         pass
'-13.2'
'14.2'
'3.0'

This has disadvantages too however. If someone types in "1,000", this will be converted to 1. Also, it assumes that people will be inputting with whitespace between words. This is not the case with other languages, such as Chinese.

How to convert a Java object (bean) to key-value pairs (and vice versa)?

If you do not want to hardcode calls to each getter and setter, reflection is the only way to call these methods (but it is not hard).

Can you refactor the class in question to use a Properties object to hold the actual data, and let each getter and setter just call get/set on it? Then you have a structure well suited for what you want to do. There is even methods to save and load them in the key-value form.

Is there any way to return HTML in a PHP function? (without building the return value as a string)

You can use a heredoc, which supports variable interpolation, making it look fairly neat:

function TestBlockHTML ($replStr) {
return <<<HTML
    <html>
    <body><h1>{$replStr}</h1>
    </body>
    </html>
HTML;
}

Pay close attention to the warning in the manual though - the closing line must not contain any whitespace, so can't be indented.

"A lambda expression with a statement body cannot be converted to an expression tree"

For your specific case, the body is for creating a variable, and switching to IEnumerable will force all the operations to be processed on client-side, I propose the following solution.

Obj[] myArray = objects
.Select(o => new
{
    SomeLocalVar = o.someVar, // You can even use any LINQ statement here
    Info = o,
}).Select(o => new Obj()
{
    Var1 = o.SomeLocalVar,
    Var2 = o.Info.var2,
    Var3 = o.SomeLocalVar.SubValue1,
    Var4 = o.SomeLocalVar.SubValue2,
}).ToArray();

Edit: Rename for C# Coding Convention

DOS: find a string, if found then run another script

@echo off
cls
MD %homedrive%\TEMPBBDVD\
CLS
TIMEOUT /T 1 >NUL
CLS
systeminfo >%homedrive%\TEMPBBDVD\info.txt
cls
timeout /t 3 >nul
cls
find "x64-based PC" %homedrive%\TEMPBBDVD\info.txt >nul
if %errorlevel% equ 1 goto 32bitsok
goto 64bitsok
cls

:commandlineerror
cls
echo error, command failed or you not are using windows OS.
pause >nul
cls
exit

:64bitsok
cls
echo done, system of 64 bits
pause >nul
cls
del /q /f %homedrive%\TEMPBBDVD\info.txt >nul
cls
timeout /t 1 >nul
cls
RD %homedrive%\TEMPBBDVD\ >nul
cls
exit

:32bitsok
cls
echo done, system of 32 bits
pause >nul
cls
del /q /f %homedrive%\TEMPBBDVD\info.txt >nul
cls
timeout /t 1 >nul
cls
RD %homedrive%\TEMPBBDVD\ >nul
cls
exit

Java Best Practices to Prevent Cross Site Scripting

Use both. In fact refer a guide like the OWASP XSS Prevention cheat sheet, on the possible cases for usage of output encoding and input validation.

Input validation helps when you cannot rely on output encoding in certain cases. For instance, you're better off validating inputs appearing in URLs rather than encoding the URLs themselves (Apache will not serve a URL that is url-encoded). Or for that matter, validate inputs that appear in JavaScript expressions.

Ultimately, a simple thumb rule will help - if you do not trust user input enough or if you suspect that certain sources can result in XSS attacks despite output encoding, validate it against a whitelist.

Do take a look at the OWASP ESAPI source code on how the output encoders and input validators are written in a security library.

AttributeError: 'module' object has no attribute 'model'

Searching

AttributeError: 'module' object has no attribute 'BinaryField'

landed me here.

The above answers did not solve the problem, so I'm posting my answer.

BinaryField was added since Django 1.6. If you have an older version, it will give you the above error.

You may want to check the spelling of the attribute first, as suggested in the above answers, and then check to make sure the module in the Django version indeed has the attribute.

MySQL select where column is not empty

Another alternative is to look specifically at the CHAR_LENGTH of the column values. (not to be confused with LENGTH)

Using a criteria where the character length is greater than 0, will avoid false positives when the column values can be falsey, such as in the event of an integer column with a value of 0 or NULL. Behaving more consistently across varying data-types.

Which results in any value that is at least 1 character long, or otherwise not empty.

Example https://www.db-fiddle.com/f/iQvEhY1SH6wfruAvnmWdj5/1

SELECT phone, phone2
FROM users
WHERE phone LIKE '813%'
AND CHAR_LENGTH(phone2) > 0

Table Data

users
phone (varchar 12) | phone2 (int 10)
"813-123-4567"     | NULL
"813-123-4567"     | 1
"813-123-4567"     | 0

users2
phone (varchar 12) | phone2 (varchar 12)
"813-123-4567"     | NULL
"813-123-4567"     | "1"
"813-123-4567"     | "0"
"813-123-4567"     | ""

CHAR_LENGTH(phone2) > 0 Results (same)

users
813-123-4567       | 1
813-123-4567       | 0

users2
813-123-4567       | 1
813-123-4567       | 0

Alternatives

phone2 <> '' Results (different)

users
813-123-4567       | 1

users2
813-123-4567       | 1
813-123-4567       | 0

phone2 > '' Results (different)

users
813-123-4567       | 1

users2
813-123-4567       | 1
813-123-4567       | 0

COALESCE(phone2, '') <> '' Results (same)
Note: the results differ from phone2 IS NOT NULL AND phone2 <> '' which is not expected

users
813-123-4567       | 1
813-123-4567       | 0

users2
813-123-4567       | 1
813-123-4567       | 0

phone2 IS NOT NULL AND phone2 <> '' Results (different)

users
813-123-4567       | 1

users2
813-123-4567       | 1
813-123-4567       | 0

Center Contents of Bootstrap row container

With Bootstrap 4, there is a css class specifically for this. The below will center row content:

<div class="row justify-content-center">
  ...inner divs and content...
</div>

See: https://v4-alpha.getbootstrap.com/layout/grid/#horizontal-alignment, for more information.

Is there a Google Keep API?

No there isn't. If you watch the http traffic and dump the page source you can see that there is an API below the covers, but it's not published nor available for 3rd party apps.

Check this link: https://developers.google.com/gsuite/products for updates.

However, there is an unofficial Python API under active development: https://github.com/kiwiz/gkeepapi

django change default runserver port

Create a subclass of django.core.management.commands.runserver.Command and overwrite the default_port member. Save the file as a management command of your own, e.g. under <app-name>/management/commands/runserver.py:

from django.conf import settings
from django.core.management.commands import runserver

class Command(runserver.Command):
    default_port = settings.RUNSERVER_PORT

I'm loading the default port form settings here (which in turn reads other configuration files), but you could just as well read it from some other file directly.

return query based on date

Find with a specific date:

db.getCollection('CollectionName').find({"DepartureDate" : new ISODate("2019-06-21T00:00:00.000Z")})

Find with greater gte or little lt :

db.getCollection('CollectionName').find({"DepartureDate" : { $gte : new ISODate("2019-06-11T00:00:00.000Z") }})

Find by range:

db.getCollection('CollectionName').find({ 
    "DepartureDate": { 
        $lt: new Date(), 
        $gte: new Date(new Date().setDate(new Date().getDate()-15))
      } 
    })

How do I update a Mongo document after inserting it?

mycollection.find_one_and_update({"_id": mongo_id}, 
                                 {"$set": {"newfield": "abc"}})

should work splendidly for you. If there is no document of id mongo_id, it will fail, unless you also use upsert=True. This returns the old document by default. To get the new one, pass return_document=ReturnDocument.AFTER. All parameters are described in the API.

The method was introduced for MongoDB 3.0. It was extended for 3.2, 3.4, and 3.6.

jQuery Validate Plugin - How to create a simple custom rule?

$(document).ready(function(){
    var response;
    $.validator.addMethod(
        "uniqueUserName", 
        function(value, element) {
            $.ajax({
                type: "POST",
                url: "http://"+location.host+"/checkUser.php",
                data: "checkUsername="+value,
                dataType:"html",
                success: function(msg)
                {
                    //If username exists, set response to true
                    response = ( msg == 'true' ) ? true : false;
                }
             });
            return response;
        },
        "Username is Already Taken"
    );

    $("#regFormPart1").validate({
        username: {
            required: true,
            minlength: 8,
            uniqueUserName: true
        },
        messages: {
            username: {
                required: "Username is required",
                minlength: "Username must be at least 8 characters",
                uniqueUserName: "This Username is taken already"
            }
        }
    });
});

How to read a line from a text file in c/c++?

im not really that good at C , but i believe this code should get you complete single line till the end...

 #include<stdio.h>

 int main()   
{      
  char line[1024];    
  FILE *f=fopen("filename.txt","r");    
  fscanf(*f,"%[^\n]",line);    
  printf("%s",line);    
 }    

Text Editor which shows \r\n?

EmEditor does this. You can also customize what symbols actually display to show them.

The following untracked working tree files would be overwritten by merge, but I don't care

Update - a better version

This tool (https://github.com/mklepaczewski/git-clean-before-merge) will:

  • delete untracked files that are identical to their git pull equivalents,
  • revert changes to modified files who's modified version is identical to their git pull equivalents,
  • report modified/untracked files that differ from their git pull version,
  • the tool has the --pretend option that will not modify any files.

Old version

How this answer differ from other answers?

The method presented here removes only files that would be overwritten by merge. If you have other untracked (possibly ignored) files in the directory this method won't remove them.

The solution

This snippet will extract all untracked files that would be overwritten by git pull and delete them.

git pull 2>&1|grep -E '^\s'|cut -f2-|xargs -I {} rm -rf "{}"

and then just do:

git pull

This is not git porcelain command so always double check what it would do with:

git pull 2>&1|grep -E '^\s'|cut -f2-|xargs -I {} echo "{}"

Explanation - because one liners are scary:

Here's a breakdown of what it does:

  1. git pull 2>&1 - capture git pull output and redirect it all to stdout so we can easily capture it with grep.
  2. grep -E '^\s - the intent is to capture the list of the untracked files that would be overwritten by git pull. The filenames have a bunch of whitespace characters in front of them so we utilize it to get them.
  3. cut -f2- - remove whitespace from the beginning of each line captured in 2.
  4. xargs -I {} rm -rf "{}" - us xargs to iterate over all files, save their name in "{}" and call rm for each of them. We use -rf to force delete and remove untracked directories.

It would be great to replace steps 1-3 with porcelain command, but I'm not aware of any equivalent.

How do I programmatically change file permissions?

If you want to set 777 permission to your created file than you can use the following method:

public void setPermission(File file) throws IOException{
    Set<PosixFilePermission> perms = new HashSet<>();
    perms.add(PosixFilePermission.OWNER_READ);
    perms.add(PosixFilePermission.OWNER_WRITE);
    perms.add(PosixFilePermission.OWNER_EXECUTE);

    perms.add(PosixFilePermission.OTHERS_READ);
    perms.add(PosixFilePermission.OTHERS_WRITE);
    perms.add(PosixFilePermission.OTHERS_EXECUTE);

    perms.add(PosixFilePermission.GROUP_READ);
    perms.add(PosixFilePermission.GROUP_WRITE);
    perms.add(PosixFilePermission.GROUP_EXECUTE);

    Files.setPosixFilePermissions(file.toPath(), perms);
}

Call a VBA Function into a Sub Procedure

To Add a Function To a new Button on your Form: (and avoid using macro to call function)

After you created your Function (Function MyFunctionName()) and you are in form design view:

  1. Add a new button (I don't think you can reassign an old button - not sure though).

  2. When the button Wizard window opens up click Cancel.

  3. Go to the Button properties Event Tab - On Click - field.

  4. At that fields drop down menu select: Event Procedure.

  5. Now click on button beside drop down menu that has ... in it and you will be taken to a new Private Sub in the forms Visual Basic window.

  6. In that Private Sub type: Call MyFunctionName
    It should look something like this:

    Private Sub Command23_Click()
    
        Call MyFunctionName
    
    End Sub
    
  7. Then just save it.

Stopping a thread after a certain amount of time

If you want to use a class:

from datetime import datetime,timedelta

class MyThread(): 

    def __init__(self, name, timeLimit):        
        self.name = name
        self.timeLimit = timeLimit
    def run(self): 
        # get the start time
        startTime = datetime.now()
    
        while True:
           # stop if the time limit is reached :
           if((datetime.now()-startTime)>self.timeLimit):
               break
           print('A')

mt = MyThread('aThread',timedelta(microseconds=20000))
mt.run()

How to convert Varchar to Int in sql server 2008?

That is how you would do it, is it throwing an error? Are you sure the value you are trying to convert is convertible? For obvious reasons you cannot convert abc123 to an int.

UPDATE

Based on your comments I would remove any spaces that are in the values you are trying to convert.

How do you display code snippets in MS Word preserving format and syntax highlighting?

Try defining a style called 'code' and make it use a small fixed width font, it should look better then.

Use CTRL+SPACEBAR to reset style.

Format Date/Time in XAML in Silverlight

C#: try this

  • yyyy(yy/yyy) - years
  • MM - months(like '03'), MMMM - months(like 'March')
  • dd - days(like 09), ddd/dddd - days(Sun/Sunday)
  • hh - hour 12(AM/PM), HH - hour 24
  • mm - minute
  • ss - second

Use some delimeter,like this:

  1. MessageBox.Show(DateValue.ToString("yyyy-MM-dd")); example result: "2014-09-30"
  2. empty format string: MessageBox.Show(DateValue.ToString()); example result: "30.09.2014 0:00:00"

Multiple files upload (Array) with CodeIgniter 2.0

You should use this library for multi upload in CI https://github.com/stvnthomas/CodeIgniter-Multi-Upload

Installation Simply copy the MY_Upload.php file to your applications library directory.

Use: function test_up in controller

public function test_up(){
if($this->input->post('submit')){
    $path = './public/test_upload/';
    $this->load->library('upload');
    $this->upload->initialize(array(
        "upload_path"=>$path,
        "allowed_types"=>"*"
    ));
    if($this->upload->do_multi_upload("myfile")){
        echo '<pre>';
        print_r($this->upload->get_multi_upload_data());
        echo '</pre>';
    }
}else{
    $this->load->view('test/upload_view');
}

}

upload_view.php in applications/view/test folder

<form action="" method="post" enctype="multipart/form-data">
<input type="file" name="myfile[]" id="myfile" multiple>
<input type="submit" name="submit" id="submit" value="submit"/>

Can we pass parameters to a view in SQL?

As already stated you can't.

A possible solution would be to implement a stored function, like:

CREATE FUNCTION v_emp (@pintEno INT)
RETURNS TABLE
AS
RETURN
   SELECT * FROM emp WHERE emp_id=@pintEno;

This allows you to use it as a normal view, with:

SELECT * FROM v_emp(10)

Fastest way to determine if record exists

SELECT CASE WHEN EXISTS (SELECT TOP 1 *
                         FROM dbo.[YourTable] 
                         WHERE [YourColumn] = [YourValue]) 
            THEN CAST (1 AS BIT) 
            ELSE CAST (0 AS BIT) END

This approach returns a boolean for you.

Revert a jQuery draggable object back to its original container on out event of droppable

I'm not sure if this will work for your actual use, but it works in your test case - updated at http://jsfiddle.net/sTD8y/27/ .

I just made it so that the built-in revert is only used if the item has not been dropped before. If it has been dropped, the revert is done manually. You could adjust this to animate to some calculated offset by checking the actual CSS properties, but I'll let you play with that because a lot of it depends on the CSS of the draggable and it's surrounding DOM structure.

$(function() {
    $("#draggable").draggable({
        revert:  function(dropped) {
             var $draggable = $(this),
                 hasBeenDroppedBefore = $draggable.data('hasBeenDropped'),
                 wasJustDropped = dropped && dropped[0].id == "droppable";
             if(wasJustDropped) {
                 // don't revert, it's in the droppable
                 return false;
             } else {
                 if (hasBeenDroppedBefore) {
                     // don't rely on the built in revert, do it yourself
                     $draggable.animate({ top: 0, left: 0 }, 'slow');
                     return false;
                 } else {
                     // just let the built in revert work, although really, you could animate to 0,0 here as well
                     return true;
                 }
             }
        }
    });

    $("#droppable").droppable({
        activeClass: 'ui-state-hover',
        hoverClass: 'ui-state-active',
        drop: function(event, ui) {
            $(this).addClass('ui-state-highlight').find('p').html('Dropped!');
            $(ui.draggable).data('hasBeenDropped', true);
        }
    });
});

How to hide the soft keyboard from inside a fragment?

Nothing but the following line of code worked for me:

getActivity().getWindow().setSoftInputMode(
            WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);

Android emulator: could not get wglGetExtensionsStringARB error

I faced the similar problem. In my case I had created the new virtual device and had enabled the snapshot. I just unchecked the checkbox Go to AVD Manager -> Select the device -> click Edit and uncheck the Enabled checkbox. I hope this works.

How to get the jQuery $.ajax error response text?

This will allow you to see the whole response not just the "responseText" value

error: function(xhr, status, error) {
    var acc = []
    $.each(xhr, function(index, value) {
        acc.push(index + ': ' + value);
    });
    alert(JSON.stringify(acc));
}

Multiple submit buttons in the same form calling different Servlets

If you use jQuery, u can do it like this:

<form action="example" method="post" id="loginform">
  ...
  <input id="btnin" type="button" value="login"/>
  <input id="btnreg" type="button" value="regist"/>
</form>

And js will be:

$("#btnin").click(function(){
   $("#loginform").attr("action", "user_login");
   $("#loginform").submit();
}
$("#btnreg").click(function(){
   $("#loginform").attr("action", "user_regist");
   $("#loginform").submit();
}

How to measure elapsed time in Python?

I like it simple (python 3):

from timeit import timeit

timeit(lambda: print("hello"))

Output is microseconds for a single execution:

2.430883963010274

Explanation: timeit executes the anonymous function 1 million times by default and the result is given in seconds. Therefore the result for 1 single execution is the same amount but in microseconds on average.


For slow operations add a lower number of iterations or you could be waiting forever:

import time

timeit(lambda: time.sleep(1.5), number=1)

Output is always in seconds for the total number of iterations:

1.5015795179999714

How to get MAC address of client using PHP?

Use this function to get the client MAC address:

function GetClientMac(){
    $macAddr=false;
    $arp=`arp -n`;
    $lines=explode("\n", $arp);

    foreach($lines as $line){
        $cols=preg_split('/\s+/', trim($line));

        if ($cols[0]==$_SERVER['REMOTE_ADDR']){
            $macAddr=$cols[2];
        }
    }

    return $macAddr;
}

PHP + MySQL transactions examples

When using PDO connection:

$pdo = new PDO('mysql:host=localhost;dbname=mydb;charset=utf8', $user, $pass, [
    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION, // this is important
]);

I often use the following code for transaction management:

function transaction(Closure $callback)
{
    global $pdo; // let's assume our PDO connection is in a global var

    // start the transaction outside of the try block, because
    // you don't want to rollback a transaction that failed to start
    $pdo->beginTransaction(); 
    try
    {
        $callback();
        $pdo->commit(); 
    }
    catch (Exception $e) // it's better to replace this with Throwable on PHP 7+
    {
        $pdo->rollBack();
        throw $e; // we still have to complain about the exception
    }
}

Usage example:

transaction(function()
{
    global $pdo;

    $pdo->query('first query');
    $pdo->query('second query');
    $pdo->query('third query');
});

This way the transaction-management code is not duplicated across the project. Which is a good thing, because, judging from other PDO-ralated answers in this thread, it's easy to make mistakes in it. The most common ones being forgetting to rethrow the exception and starting the transaction inside the try block.

AngularJS directive does not update on scope variable changes

A simple solution is to make the scope variable object. Then access the content with {{ whatever-object.whatever-property }}. The variable is not updating because JavaScript pass Primitive type by value. Whereas Object are passed by reference which solves the problem.

Setting values of input fields with Angular 6

You should use the following:

       <td><input id="priceInput-{{orderLine.id}}" type="number" [(ngModel)]="orderLine.price"></td>

You will need to add the FormsModule to your app.module in the inputs section as follows:

import { FormsModule } from '@angular/forms';

@NgModule({
  declarations: [
    ...
  ],
  imports: [
    BrowserModule,
    FormsModule
  ],
  ..

The use of the brackets around the ngModel are as follows:

  • The [] show that it is taking an input from your TS file. This input should be a public member variable. A one way binding from TS to HTML.

  • The () show that it is taking output from your HTML file to a variable in the TS file. A one way binding from HTML to TS.

  • The [()] are both (e.g. a two way binding)

See here for more information: https://angular.io/guide/template-syntax

I would also suggest replacing id="priceInput-{{orderLine.id}}" with something like this [id]="getElementId(orderLine)" where getElementId(orderLine) returns the element Id in the TS file and can be used anywere you need to reference the element (to avoid simple bugs like calling it priceInput1 in one place and priceInput-1 in another. (if you still need to access the input by it's Id somewhere else)

Git Server Like GitHub?

If you want pull requests, there are the open source projects of RhodeCode and GitLab and the paid Stash

How to enable mod_rewrite for Apache 2.2

The first time I struggled with mod_rewrite rules ignoring my traffic, I learned (frustratingly) that I had placed them in the wrong <VirtualHost>, which meant that my traffic would ignore all of them no matter how well-written they were. Make sure this isn't happening to you:

# Change the log location to suit your system. RewriteLog /var/log/apache-rw.log RewriteLogLevel 2

These parameters will activate if you perform a graceful restart of Apache, so you can recycle them in and closely monitor the mod_rewrite behavior. Once your problem is fixed, turn the RewriteLogLevel back down and celebrate.

In 100% of my experience, I've found that the RewriteLog has helped me discover the problem with my rewrite rules. I can't recommend this enough. Good luck in your troubleshooting!

Also, this bookmark is your best friend: http://httpd.apache.org/docs/2.2/mod/mod_rewrite.html#rewritelog

Run a single test method with maven

I tried several solutions provided in this thread, however they were not working for module which depends on a different one. In that case I had to run mvn from the root-module with additional parameters: -am (--also-make), which tells maven to built modules which your test module depends on and -DfailIfNoTests=false, otherwise "No tests were executed!" error appears.

mvn test -pl B -Dtest=MyTestClass#myTest -am -DfailIfNoTests=false

pom.xml section in root:

<modules>
    <module>A</module>
    <module>B</module>
<modules>

B depends on A.

jQuery hyperlinks - href value?

I almost had this problem and it was very deceiving. I am providing an answer in case someone winds up in my same position.

  1. I thought I had this problem
  2. But, I was using return false and javascript:void(0);
  3. Then a distinct difference in problem kept surfacing:
  4. I realized it's not going ALL the way to the top - and my problem zone was near the bottom of the page so this jump was strange and annoying.
  5. I realized I was using fadeIn() [jQuery library], which for a short time my content was display:none
  6. And then my content extended the reach of the page! Causing what looks like a jump!
  7. Using visibility hidden toggles now..

Hope this helps the person stuck with jumps!!

How to use `replace` of directive definition?

You are getting confused with transclude: true, which would append the inner content.

replace: true means that the content of the directive template will replace the element that the directive is declared on, in this case the <div myd1> tag.

http://plnkr.co/edit/k9qSx15fhSZRMwgAIMP4?p=preview

For example without replace:true

<div myd1><span class="replaced" myd1="">directive template1</span></div>

and with replace:true

<span class="replaced" myd1="">directive template1</span>

As you can see in the latter example, the div tag is indeed replaced.

init-param and context-param

What is the difference between <init-param> and <context-param> !?

Single servlet versus multiple servlets.

Other Answers give details, but here is the summary:

A web app, that is, a “context”, is made up of one or more servlets.

  • <init-param> defines a value available to a single specific servlet within a context.
  • <context-param> defines a value available to all the servlets within a context.

How to extract a substring using regex

In Scala,

val ticks = "'([^']*)'".r

ticks findFirstIn mydata match {
    case Some(ticks(inside)) => println(inside)
    case _ => println("nothing")
}

for (ticks(inside) <- ticks findAllIn mydata) println(inside) // multiple matches

val Some(ticks(inside)) = ticks findFirstIn mydata // may throw exception

val ticks = ".*'([^']*)'.*".r    
val ticks(inside) = mydata // safe, shorter, only gets the first set of ticks

Javascript loop through object array?

The suggested for loop is quite fine but you have to check the properties with hasOwnProperty. I'd rather suggest using Object.keys() that only returns 'own properties' of the object (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys)

_x000D_
_x000D_
var data = {_x000D_
    "messages": [{_x000D_
        "msgFrom": "13223821242",_x000D_
        "msgBody": "Hi there"_x000D_
    }, {_x000D_
        "msgFrom": "Bill",_x000D_
        "msgBody": "Hello!"_x000D_
    }]_x000D_
};_x000D_
_x000D_
data.messages.forEach(function(message, index) {_x000D_
    console.log('message index '+ index);_x000D_
    Object.keys(message).forEach(function(prop) {    _x000D_
        console.log(prop + " = " + message[prop]);_x000D_
    });_x000D_
});
_x000D_
_x000D_
_x000D_

Sort tuples based on second parameter

    def findMaxSales(listoftuples):
        newlist = []
        tuple = ()
        for item in listoftuples:
             movie = item[0]
             value = (item[1])
             tuple = value, movie

             newlist += [tuple]
             newlist.sort()
             highest = newlist[-1]
             result = highest[1]
       return result

             movieList = [("Finding Dory", 486), ("Captain America: Civil                      

             War", 408), ("Deadpool", 363), ("Zootopia", 341), ("Rogue One", 529), ("The  Secret Life of Pets", 368), ("Batman v Superman", 330), ("Sing", 268), ("Suicide Squad", 325), ("The Jungle Book", 364)]
             print(findMaxSales(movieList))

output --> Rogue One

Excel VBA date formats

To ensure that a cell will return a date value and not just a string that looks like a date, first you must set the NumberFormat property to a Date format, then put a real date into the cell's content.

Sub test_date_or_String()
 Set c = ActiveCell
 c.NumberFormat = "@"
 c.Value = CDate("03/04/2014")
   Debug.Print c.Value & " is a " & TypeName(c.Value) 'C is a String
 c.NumberFormat = "m/d/yyyy"
   Debug.Print c.Value & " is a " & TypeName(c.Value) 'C is still a String
 c.Value = CDate("03/04/2014")
   Debug.Print c.Value & " is a " & TypeName(c.Value) 'C is a date    
End Sub

Defining array with multiple types in TypeScript

My TS lint was complaining about other solutions, so the solution that was working for me was:

item: Array<Type1 | Type2>

if there's only one type, it's fine to use:

item: Type1[]

What browsers support HTML5 WebSocket API?

Client side

  • Hixie-75:
    • Chrome 4.0 + 5.0
    • Safari 5.0.0
  • HyBi-00/Hixie-76:
  • HyBi-07+:
  • HyBi-10:
    • Chrome 14.0 + 15.0
    • Firefox 7.0 + 8.0 + 9.0 + 10.0 - prefixed: MozWebSocket
    • IE 10 (from Windows 8 developer preview)
  • HyBi-17/RFC 6455
    • Chrome 16
    • Firefox 11
    • Opera 12.10 / Opera Mobile 12.1

Any browser with Flash can support WebSocket using the web-socket-js shim/polyfill.

See caniuse for the current status of WebSockets support in desktop and mobile browsers.

See the test reports from the WS testsuite included in Autobahn WebSockets for feature/protocol conformance tests.


Server side

It depends on which language you use.

In Java/Java EE:

Some other Java implementations:

In C#:

In PHP:

In Python:

In C:

In Node.js:

  • Socket.io : Socket.io also has serverside ports for Python, Java, Google GO, Rack
  • sockjs : sockjs also has serverside ports for Python, Java, Erlang and Lua
  • WebSocket-Node - Pure JavaScript Client & Server implementation of HyBi-10.

Vert.x (also known as Node.x) : A node like polyglot implementation running on a Java 7 JVM and based on Netty with :

  • Support for Ruby(JRuby), Java, Groovy, Javascript(Rhino/Nashorn), Scala, ...
  • True threading. (unlike Node.js)
  • Understands multiple network protocols out of the box including: TCP, SSL, UDP, HTTP, HTTPS, Websockets, SockJS as fallback for WebSockets

Pusher.com is a Websocket cloud service accessible through a REST API.

DotCloud cloud platform supports Websockets, and Java (Jetty Servlet Container), NodeJS, Python, Ruby, PHP and Perl programming languages.

Openshift cloud platform supports websockets, and Java (Jboss, Spring, Tomcat & Vertx), PHP (ZendServer & CodeIgniter), Ruby (ROR), Node.js, Python (Django & Flask) plateforms.

For other language implementations, see the Wikipedia article for more information.

The RFC for Websockets : RFC6455

Java Multithreading concept and join() method

The JVM and the underlying OS have considerable freedom when scheduling things. The fact that you get all the way to "Waiting for threads to finish" before you see the output from individual threads may simply mean that thread start-up takes a bit longer (i.e. it takes some time between the moment when a thread becomes "alive" and when the run() method actually starts executing). You could conceivably see thread output sooner but it's not guaranteed either way.

As for join(), it only guarantees that whatever is after it will only happen once the thread you are joining is done. So when you have three join() calls in a row it doesn't mean the threads should end in a particular order. It simply means that you will wait for ob1 first. Once ob1 finishes, ob2 and ob3 may be still running or they may already be finished. If they are finished, your other join() calls will return immediately.

synchronized is used specifically when multiple threads access the same object and make changes to it. A synchronized block is guaranteed never to be executed by two threads simultaneously - i.e. the thread that executes it has the synchronized object all to itself.

Convert to date format dd/mm/yyyy

You can use a regular expression or some manual string fiddling, but I think I prefer:

date("d/m/Y", strtotime($str));

Login failed for user 'DOMAIN\MACHINENAME$'

NETWORK SERVICE and LocalSystem will authenticate themselves always as the correpsonding account locally (builtin\network service and builtin\system) but both will authenticate as the machine account remotely.

If you see a failure like Login failed for user 'DOMAIN\MACHINENAME$' it means that a process running as NETWORK SERVICE or as LocalSystem has accessed a remote resource, has authenticated itself as the machine account and was denied authorization.

Typical example would be an ASP application running in an app pool set to use NETWORK SERVICE credential and connecting to a remote SQL Server: the app pool will authenticate as the machine running the app pool, and is this machine account that needs to be granted access.

When access is denied to a machine account, then access must be granted to the machine account. If the server refuses to login 'DOMAIN\MACHINE$', then you must grant login rights to 'DOMAIN\MACHINE$' not to NETWORK SERVICE. Granting access to NETWORK SERVICE would allow a local process running as NETWORK SERVICE to connect, not a remote one, since the remote one will authenticate as, you guessed, DOMAIN\MACHINE$.

If you expect the asp application to connect to the remote SQL Server as a SQL login and you get exceptions about DOMAIN\MACHINE$ it means you use Integrated Security in the connection string. If this is unexpected, it means you screwed up the connection strings you use.

Printing tuple with string formatting in Python

>>> thetuple = (1, 2, 3)
>>> print "this is a tuple: %s" % (thetuple,)
this is a tuple: (1, 2, 3)

Making a singleton tuple with the tuple of interest as the only item, i.e. the (thetuple,) part, is the key bit here.

How to debug JavaScript / jQuery event bindings with Firebug or similar tools?

jQuery stores events in the following:

$("a#somefoo").data("events")

Doing a console.log($("a#somefoo").data("events")) should list the events attached to that element.

Using intents to pass data between activities

Main Activity

public class MainActivity extends Activity {

    EditText user, password;
    Button login;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        user = (EditText) findViewById(R.id.username_edit);
        password = (EditText) findViewById(R.id.edit_password);
        login = (Button) findViewById(R.id.btnSubmit);
        login.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this,Second.class);

                String uservalue = user.getText().toString();
                String name_value = password.getText().toString();
                String password_value = password.getText().toString();

                intent.putExtra("username", uservalue);
                intent.putExtra("password", password_value);
                startActivity(intent);
            }
        });
    }
}

Second Activity in which you want to receive Data

public class Second extends Activity{

    EditText name, pass;
    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.second_activity);

        name = (EditText) findViewById(R.id.editText1);
        pass = (EditText) findViewById(R.id.editText2);

        String value = getIntent().getStringExtra("username");
        String pass_val = getIntent().getStringExtra("password");
        name.setText(value);
        pass.setText(pass_val);
    }
}

Remove Rows From Data Frame where a Row matches a String

if you wish to using dplyr, for to remove row "Foo":

df %>%
 filter(!C=="Foo")

How to add values in a variable in Unix shell scripting?

 echo "$x"
    x=10
    echo "$y"`enter code here`
    y=10
    echo $[$x+$y]

Answer: 20

What is the right way to check for a null string in Objective-C?

it is just as simple as

if([object length] >0)
{
  // do something
}

remember that in objective C if object is null it returns 0 as the value.

This will get you both a null string and a 0 length string.

ComboBox.SelectedText doesn't give me the SelectedText

All of the previous answers explain what the OP 'should' do. I am explaining what the .SelectedText property is.

The .SelectedText property is not the text in the combobox. It is the text that is highlighted. It is the same as .SelectedText property for a textbox.

The following picture shows that the .SelectedText property would be equal to "ort".

enter image description here

typescript - cloning object

You can also have something like this:

class Entity {
    id: number;

    constructor(id: number) {
        this.id = id;
    }

    clone(): this {
        return new (this.constructor as typeof Entity)(this.id) as this;
    }
}

class Customer extends Entity {
    name: string;

    constructor(id: number, name: string) {
        super(id);
        this.name = name;
    }

    clone(): this {
        return new (this.constructor as typeof Customer)(this.id, this.name) as this;
    }
}

Just make sure that you override the clone method in all Entity subclasses otherwise you'll end up with partial clones.

The return type of this will always match the type of the instance.

VHDL - How should I create a clock in a testbench?

If multiple clock are generated with different frequencies, then clock generation can be simplified if a procedure is called as concurrent procedure call. The time resolution issue, mentioned by Martin Thompson, may be mitigated a little by using different high and low time in the procedure. The test bench with procedure for clock generation is:

library ieee;
use ieee.std_logic_1164.all;

entity tb is
end entity;

architecture sim of tb is

  -- Procedure for clock generation
  procedure clk_gen(signal clk : out std_logic; constant FREQ : real) is
    constant PERIOD    : time := 1 sec / FREQ;        -- Full period
    constant HIGH_TIME : time := PERIOD / 2;          -- High time
    constant LOW_TIME  : time := PERIOD - HIGH_TIME;  -- Low time; always >= HIGH_TIME
  begin
    -- Check the arguments
    assert (HIGH_TIME /= 0 fs) report "clk_plain: High time is zero; time resolution to large for frequency" severity FAILURE;
    -- Generate a clock cycle
    loop
      clk <= '1';
      wait for HIGH_TIME;
      clk <= '0';
      wait for LOW_TIME;
    end loop;
  end procedure;

  -- Clock frequency and signal
  signal clk_166 : std_logic;
  signal clk_125 : std_logic;

begin

  -- Clock generation with concurrent procedure call
  clk_gen(clk_166, 166.667E6);  -- 166.667 MHz clock
  clk_gen(clk_125, 125.000E6);  -- 125.000 MHz clock

  -- Time resolution show
  assert FALSE report "Time resolution: " & time'image(time'succ(0 fs)) severity NOTE;

end architecture;

The time resolution is printed on the terminal for information, using the concurrent assert last in the test bench.

If the clk_gen procedure is placed in a separate package, then reuse from test bench to test bench becomes straight forward.

Waveform for clocks are shown in figure below.

Waveforms for clk_166 and clk_125

An more advanced clock generator can also be created in the procedure, which can adjust the period over time to match the requested frequency despite the limitation by time resolution. This is shown here:

-- Advanced procedure for clock generation, with period adjust to match frequency over time, and run control by signal
procedure clk_gen(signal clk : out std_logic; constant FREQ : real; PHASE : time := 0 fs; signal run : std_logic) is
  constant HIGH_TIME   : time := 0.5 sec / FREQ;  -- High time as fixed value
  variable low_time_v  : time;                    -- Low time calculated per cycle; always >= HIGH_TIME
  variable cycles_v    : real := 0.0;             -- Number of cycles
  variable freq_time_v : time := 0 fs;            -- Time used for generation of cycles
begin
  -- Check the arguments
  assert (HIGH_TIME /= 0 fs) report "clk_gen: High time is zero; time resolution to large for frequency" severity FAILURE;
  -- Initial phase shift
  clk <= '0';
  wait for PHASE;
  -- Generate cycles
  loop
    -- Only high pulse if run is '1' or 'H'
    if (run = '1') or (run = 'H') then
      clk <= run;
    end if;
    wait for HIGH_TIME;
    -- Low part of cycle
    clk <= '0';
    low_time_v := 1 sec * ((cycles_v + 1.0) / FREQ) - freq_time_v - HIGH_TIME;  -- + 1.0 for cycle after current
    wait for low_time_v;
    -- Cycle counter and time passed update
    cycles_v := cycles_v + 1.0;
    freq_time_v := freq_time_v + HIGH_TIME + low_time_v;
  end loop;
end procedure;

Again reuse through a package will be nice.

Move textfield when keyboard appears swift

Just enclose your textbox inside a view and then override inputAccessoryView returning the view. Important: Your view should be created programmatically. Do not use @IBOutlets.

 override var inputAccessoryView: UIView? {
    get {
        return newlyProgramaticallyCreatedView
    }}

SQLDataReader Row Count

This will get you the row count, but will leave the data reader at the end.

dataReader.Cast<object>().Count();

How to use MapView in android using google map V2?

I created dummy sample for Google Maps v2 Android with Kotlin and AndroidX

You can find complete project here: github-link

MainActivity.kt

class MainActivity : AppCompatActivity() {

val position = LatLng(-33.920455, 18.466941)

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    with(mapView) {
        // Initialise the MapView
        onCreate(null)
        // Set the map ready callback to receive the GoogleMap object
        getMapAsync{
            MapsInitializer.initialize(applicationContext)
            setMapLocation(it)
        }
    }
}

private fun setMapLocation(map : GoogleMap) {
    with(map) {
        moveCamera(CameraUpdateFactory.newLatLngZoom(position, 13f))
        addMarker(MarkerOptions().position(position))
        mapType = GoogleMap.MAP_TYPE_NORMAL
        setOnMapClickListener {
            Toast.makeText(this@MainActivity, "Clicked on map", Toast.LENGTH_SHORT).show()
        }
    }
}

override fun onResume() {
    super.onResume()
    mapView.onResume()
}

override fun onPause() {
    super.onPause()
    mapView.onPause()
}

override fun onDestroy() {
    super.onDestroy()
    mapView.onDestroy()
}

override fun onLowMemory() {
    super.onLowMemory()
    mapView.onLowMemory()
 }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools" package="com.murgupluoglu.googlemap">

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

<application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme"
        tools:ignore="GoogleAppIndexingWarning">
    <meta-data
            android:name="com.google.android.geo.API_KEY"
            android:value="API_KEY_HERE" />
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN"/>

            <category android:name="android.intent.category.LAUNCHER"/>
        </intent-filter>
    </activity>
</application>

</manifest>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

<com.google.android.gms.maps.MapView
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:id="@+id/mapView"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"/>

</androidx.constraintlayout.widget.ConstraintLayout>

How do I loop through a date range?

Code from @mquander and @Yogurt The Wise used in extensions:

public static IEnumerable<DateTime> EachDay(DateTime from, DateTime thru)
{
    for (var day = from.Date; day.Date <= thru.Date; day = day.AddDays(1))
        yield return day;
}

public static IEnumerable<DateTime> EachMonth(DateTime from, DateTime thru)
{
    for (var month = from.Date; month.Date <= thru.Date || month.Month == thru.Month; month = month.AddMonths(1))
        yield return month;
}

public static IEnumerable<DateTime> EachDayTo(this DateTime dateFrom, DateTime dateTo)
{
    return EachDay(dateFrom, dateTo);
}

public static IEnumerable<DateTime> EachMonthTo(this DateTime dateFrom, DateTime dateTo)
{
    return EachMonth(dateFrom, dateTo);
}

What is "Linting"?

Interpreted languages like Python and JavaScript benefit greatly from linting, as these languages don’t have a compiling phase to display errors before execution.

Linters are also useful for code formatting and/or adhering to language specific best practices.

Lately I have been using ESLint for JS/React and will occasionally use it with an airbnb-config file.

Detecting which UIButton was pressed in a UITableView

Found a nice solution to this problem elsewhere, no messing around with tags on the button:

- (void)buttonPressedAction:(id)sender {

    NSSet *touches = [event allTouches];
    UITouch *touch = [touches anyObject];
    CGPoint currentTouchPosition = [touch locationInView:self.tableView];
    NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint: currentTouchPosition];

    // do stuff with the indexPath...
}

How to Detect Browser Window /Tab Close Event?

Yes there is! After a lot of headache i found one solution to this.

Monitor.php

This php file will be monitoring the browser close event. Once the browser is closed the connection_aborted will return 1 hence the loop will break.

<?php
// Ignore user aborts and allow the script
// to run forever
ignore_user_abort(true);
set_time_limit(0);

echo connection_aborted();
while(1)
{
echo "Whatever you echo here wont be printed anywhere but it is required in order to work.";
flush();
if(connection_aborted())
{
break;
// Breaks only when browser is closed
}
}

/*
Action you want to take after browser is closed.
Write your code here
*/
?>

Caller.php

This is the file which will call Monitor.php

<?php
Header('Location: monitor.php');
?>

Parent.html

This will be the file which you will actually interact with. On loading this will directly make an AJAX call to Caller.php which will automatically start Monitor.php in background mode.

<script>

 var xmlhttp = new XMLHttpRequest();
        xmlhttp.onreadystatechange = function() {
            if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {

            }
         }

   xmlhttp.open("GET", "Caller.php", true);
        xmlhttp.send();   

</script>

So the final flow is Parent.html----->Caller.php----->Monitor.php

How to read/process command line arguments?

My solution is entrypoint2. Example:

from entrypoint2 import entrypoint
@entrypoint
def add(file, quiet=True): 
    ''' This function writes report.

    :param file: write report to FILE
    :param quiet: don't print status messages to stdout
    '''
    print file,quiet

help text:

usage: report.py [-h] [-q] [--debug] file

This function writes report.

positional arguments:
  file         write report to FILE

optional arguments:
  -h, --help   show this help message and exit
  -q, --quiet  don't print status messages to stdout
  --debug      set logging level to DEBUG

How to sort the letters in a string alphabetically in Python

Sorted() solution can give you some unexpected results with other strings.

List of other solutions:

Sort letters and make them distinct:

>>> s = "Bubble Bobble"
>>> ''.join(sorted(set(s.lower())))
' belou'

Sort letters and make them distinct while keeping caps:

>>> s = "Bubble Bobble"
>>> ''.join(sorted(set(s)))
' Bbelou'

Sort letters and keep duplicates:

>>> s = "Bubble Bobble"
>>> ''.join(sorted(s))
' BBbbbbeellou'

If you want to get rid of the space in the result, add strip() function in any of those mentioned cases:

>>> s = "Bubble Bobble"
>>> ''.join(sorted(set(s.lower()))).strip()
'belou'

How to add background-image using ngStyle (angular2)?

import {BrowserModule, DomSanitizer} from '@angular/platform-browser'

  constructor(private sanitizer:DomSanitizer) {
    this.name = 'Angular!'
    this.backgroundImg = sanitizer.bypassSecurityTrustStyle('url(http://www.freephotos.se/images/photos_medium/white-flower-4.jpg)');
  }
<div [style.background-image]="backgroundImg"></div>

See also

Open a URL without using a browser from a batch file

If all you want is to request the URL and if it needs to be done from batch file, without anything outside of the OS, this can help you:

@if (@This==@IsBatch) @then
@echo off
rem **** batch zone *********************************************************

    setlocal enableextensions disabledelayedexpansion

    rem The batch file will delegate all the work to the script engine
    if not "%~1"=="" (
        wscript //E:JScript "%~dpnx0" %1
    )

    rem End of batch file area. Ensure the batch file ends execution
    rem before reaching the JavaScript zone
    exit /b

@end


// **** JavaScript zone *****************************************************
// Instantiate the needed component to make URL queries
var http = WScript.CreateObject('Msxml2.XMLHTTP.6.0');

// Retrieve the URL parameter
var url = WScript.Arguments.Item(0)

// Make the request

http.open("GET", url, false);
http.send();

// All done. Exit
WScript.Quit(0);

It is just a hybrid batch/JavaScript file and is saved as callurl.cmd and called as callurl "http://www.google.es". It will do what you ask for. No error check, no post, just a skeleton.

If it is possible to use something outside of the OS, wget or curl are available as Windows executables and are the best options available.

If you are limited by some kind of security policy, you can get the Internet Information Services (IIS) 6.0 Resource Kit Tools. It includes tinyget and wfetch tools that can do what you need.

Read CSV with Scanner()

Please stop writing faulty CSV parsers!

I've seen hundreds of CSV parsers and so called tutorials for them online.

Nearly every one of them gets it wrong!

This wouldn't be such a bad thing as it doesn't affect me but people who try to write CSV readers and get it wrong tend to write CSV writers, too. And get them wrong as well. And these ones I have to write parsers for.

Please keep in mind that CSV (in order of increasing not so obviousness):

  1. can have quoting characters around values
  2. can have other quoting characters than "
  3. can even have other quoting characters than " and '
  4. can have no quoting characters at all
  5. can even have quoting characters on some values and none on others
  6. can have other separators than , and ;
  7. can have whitespace between seperators and (quoted) values
  8. can have other charsets than ascii
  9. should have the same number of values in each row, but doesn't always
  10. can contain empty fields, either quoted: "foo","","bar" or not: "foo",,"bar"
  11. can contain newlines in values
  12. can not contain newlines in values if they are not delimited
  13. can not contain newlines between values
  14. can have the delimiting character within the value if properly escaped
  15. does not use backslash to escape delimiters but...
  16. uses the quoting character itself to escape it, e.g. Frodo's Ring will be 'Frodo''s Ring'
  17. can have the quoting character at beginning or end of value, or even as only character ("foo""", """bar", """")
  18. can even have the quoted character within the not quoted value; this one is not escaped

If you think this is obvious not a problem, then think again. I've seen every single one of these items implemented wrongly. Even in major software packages. (e.g. Office-Suites, CRM Systems)

There are good and correctly working out-of-the-box CSV readers and writers out there:

If you insist on writing your own at least read the (very short) RFC for CSV.

Is it possible to program iPhone in C++

You have to use Objective C to interface with the Cocoa API, so there is no choice. Of course, you can use as much C++ as you like behind the scenes (Objective C++ makes this easy).

It is an insane language indeed, but it's also... kind of fun to use once you're a bit used to it. :-)

SQL Server - Case Statement

The query can be written slightly simpler, like this:

DECLARE @T INT = 2 

SELECT CASE 
         WHEN @T < 1 THEN 'less than one' 
         WHEN @T = 1 THEN 'one' 
         ELSE 'greater than one' 
       END T

What is the difference between user variables and system variables?

Environment variables are 'evaluated' (ie. they are attributed) in the following order:

  1. System variables
  2. Variables defined in autoexec.bat
  3. User variables

Every process has an environment block that contains a set of environment variables and their values. There are two types of environment variables: user environment variables (set for each user) and system environment variables (set for everyone). A child process inherits the environment variables of its parent process by default.

Programs started by the command processor inherit the command processor's environment variables.

Environment variables specify search paths for files, directories for temporary files, application-specific options, and other similar information. The system maintains an environment block for each user and one for the computer. The system environment block represents environment variables for all users of the particular computer. A user's environment block represents the environment variables the system maintains for that particular user, including the set of system environment variables.

Seaborn Barplot - Displaying Values

Hope this helps for item #2: a) You can sort by total bill then reset the index to this column b) Use palette="Blue" to use this color to scale your chart from light blue to dark blue (if dark blue to light blue then use palette="Blues_d")

import pandas as pd
import seaborn as sns
%matplotlib inline

df=pd.read_csv("https://raw.githubusercontent.com/wesm/pydata-book/master/ch08/tips.csv", sep=',')
groupedvalues=df.groupby('day').sum().reset_index()
groupedvalues=groupedvalues.sort_values('total_bill').reset_index()
g=sns.barplot(x='day',y='tip',data=groupedvalues, palette="Blues")

Failed to create provisioning profile

Change bundle identifier, Straight solution

Using $_POST to get select option value from HTML

Like this:

<?php
  $option = $_POST['taskOption'];
?>

The index of the $_POST array is always based on the value of the name attribute of any HTML input.

ImportError: No module named pythoncom

If you're on windows you probably want the pywin32 library, which includes pythoncom and a whole lot of other stuff that is pretty standard.

Rebuild Docker container on file changes

Whenever changes are made in dockerfile or compose or requirements , re-Run it using docker-compose up --build . So that images get rebuild and refreshed

"The underlying connection was closed: An unexpected error occurred on a send." With SSL Certificate

For me it was tls12:

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

how to convert long date value to mm/dd/yyyy format

Refer below code for formatting date

long strDate1 = 1346524199000;
Date date=new Date(strDate1);

try {
        SimpleDateFormat format = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss z");
        SimpleDateFormat df2 = new SimpleDateFormat("dd/MM/yy");
        date = df2.format(format.parse("yourdate");
    } catch (java.text.ParseException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

calling parent class method from child class object in java

NOTE calling parent method via super will only work on parent class, If your parent is interface, and wants to call the default methods then need to add interfaceName before super like IfscName.super.method();

interface Vehicle {
    //Non abstract method
    public default void printVehicleTypeName() { //default keyword can be used only in interface.
        System.out.println("Vehicle");
    }
}


class FordFigo extends FordImpl implements Vehicle, Ford {
    @Override
    public void printVehicleTypeName() { 
        System.out.println("Figo");
        Vehicle.super.printVehicleTypeName();
    }
}

Interface name is needed because same default methods can be available in multiple interface name that this class extends. So explicit call to a method is required.

S3 limit to objects in a bucket

It looks like the limit has changed. You can store 5TB for a single object.

The total volume of data and number of objects you can store are unlimited. Individual Amazon S3 objects can range in size from a minimum of 0 bytes to a maximum of 5 terabytes. The largest object that can be uploaded in a single PUT is 5 gigabytes. For objects larger than 100 megabytes, customers should consider using the Multipart Upload capability.

http://aws.amazon.com/s3/faqs/#How_much_data_can_I_store

What is the difference between JDK and JRE?

Here's a simple response directly from Oracle http://docs.oracle.com/javase/7/docs/technotes/guides/

Java SE Runtime Environment (JRE)

The JRE provides the libraries, Java virtual machine, and other components necessary for you to run applets and applications written in the Java programming language. This runtime environment can be redistributed with applications to make them free-standing.

Java SE Development Kit (JDK)

The JDK includes the JRE plus command-line development tools such as compilers and debuggers that are necessary or useful for developing applets and applications.

React.js: Identifying different inputs with one onChange handler

You can use a special React attribute called ref and then match the real DOM nodes in the onChange event using React's getDOMNode() function:

handleClick: function(event) {
  if (event.target === this.refs.prev.getDOMNode()) {
    ...
  }
}

render: function() {
  ...
  <button ref="prev" onClick={this.handleClick}>Previous question</button>
  <button ref="next" onClick={this.handleClick}>Next question</button>
  ...
}

Docker expose all ports or range of ports from 7000 to 8000

For anyone facing this issue and ending up on this post...the issue is still open - https://github.com/moby/moby/issues/11185

Select current element in jQuery

When the jQuery click event calls your event handler, it sets "this" to the object that was clicked on. To turn it into a jQuery object, just pass it to the "$" function: $(this). So, to get, for example, the next sibling element, you would do this inside the click handler:

var nextSibling = $(this).next();

Edit: After reading Kevin's comment, I realized I might be mistaken about what you want. If you want to do what he asked, i.e. select the corresponding link in the other div, you could use $(this).index() to get the clicked link's position. Then you would select the link in the other div by its position, for example with the "eq" method.

var $clicked = $(this);
var linkIndex = $clicked.index();
$clicked.parent().next().children().eq(linkIndex);

If you want to be able to go both ways, you will need some way of determining which div you are in so you know if you need "next()" or "prev()" after "parent()"

strange error in my Animation Drawable

Looks like whatever is in your Animation Drawable definition is too much memory to decode and sequence. The idea is that it loads up all the items and make them in an array and swaps them in and out of the scene according to the timing specified for each frame.

If this all can't fit into memory, it's probably better to either do this on your own with some sort of handler or better yet just encode a movie with the specified frames at the corresponding images and play the animation through a video codec.

Setting the focus to a text field

In a JFrame or JDialog you can always overwrite the setVisible() method, it works well. I haven't tried in a JPanel, but can be an alternative.

@Override
public void setVisible(boolean value) {
    super.setVisible(value);
    control.requestFocusInWindow();
}

What is sharding and why is it important?

Is sharding mostly important in very large scale applications or does it apply to smaller scale ones?

Sharding is a concern if and only if your needs scale past what can be served by a single database server. It's a swell tool if you have shardable data and you have incredibly high scalability and performance requirements. I would guess that in my entire 12 years I've been a software professional, I've encountered one situation that could have benefited from sharding. It's an advanced technique with very limited applicability.

Besides, the future is probably going to be something fun and exciting like a massive object "cloud" that erases all potential performance limitations, right? :)

undefined reference to `WinMain@16'

To summarize the above post by Cheers and hth. - Alf, Make sure you have main() or WinMain() defined and g++ should do the right thing.

My problem was that main() was defined inside of a namespace by accident.

ASP.Net MVC: Calling a method from a view

You should create custom helper for just changing string format except using controller call.

how to put image in center of html page?

Hey now you can give to body background image

and set the background-position:center center;

as like this

body{
background:url('../img/some.jpg') no-repeat center center;
min-height:100%;
}

What is meant by Ems? (Android TextView)

Ems is a typography term, it controls text size, etc. Check here

Parsing PDF files (especially with tables) with PDFBox

There's PDFLayoutTextStripper that was designed to keep the format of the data.

From the README:

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

import org.apache.pdfbox.pdfparser.PDFParser;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.util.PDFTextStripper;

public class Test {

    public static void main(String[] args) {
        String string = null;
        try {
            PDFParser pdfParser = new PDFParser(new FileInputStream("sample.pdf"));
            pdfParser.parse();
            PDDocument pdDocument = new PDDocument(pdfParser.getDocument());
            PDFTextStripper pdfTextStripper = new PDFLayoutTextStripper();
            string = pdfTextStripper.getText(pdDocument);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        };
        System.out.println(string);
    }
}

How to recover MySQL database from .myd, .myi, .frm files

I found a solution for converting the files to a .sql file (you can then import the .sql file to a server and recover the database), without needing to access the /var directory, therefore you do not need to be a server admin to do this either.

It does require XAMPP or MAMP installed on your computer.

  • After you have installed XAMPP, navigate to the install directory (Usually C:\XAMPP), and the the sub-directory mysql\data. The full path should be C:\XAMPP\mysql\data
  • Inside you will see folders of any other databases you have created. Copy & Paste the folder full of .myd, .myi and .frm files into there. The path to that folder should be

    C:\XAMPP\mysql\data\foldername\.mydfiles

  • Then visit localhost/phpmyadmin in a browser. Select the database you have just pasted into the mysql\data folder, and click on Export in the navigation bar. Chooses the export it as a .sql file. It will then pop up asking where the save the file

And that is it! You (should) now have a .sql file containing the database that was originally .myd, .myi and .frm files. You can then import it to another server through phpMyAdmin by creating a new database and pressing 'Import' in the navigation bar, then following the steps to import it

How can I work with command line on synology?

The current windows 10 (Version 1803 (OS Build 17134.1)) has SSH built in. With that, just enable SSH from the Control Panel, Terminal & SNMP, be sure you are using an account in the Administrator's group, and you're all set.

Launch Powershell or CMD, enter ssh yourAccountName@diskstation

The first time it will cache off your certificate.

EDIT:

Further detailed explanations can be found on the synology docs page:

How to login to DSM with root permission via SSH Telnet

Installing python module within code

i added some exception handling to @Aaron's answer.

import subprocess
import sys

try:
    import pandas as pd
except ImportError:
    subprocess.check_call([sys.executable, "-m", "pip", "install", 'pandas'])
finally:
    import pandas as pd

Custom alert and confirm box in jquery

Try using SweetAlert its just simply the best . You will get a lot of customization and flexibility.

Confirm Example

sweetAlert(
  {
    title: "Are you sure?",
    text: "You will not be able to recover this imaginary file!",
    type: "warning",   
    showCancelButton: true,   
    confirmButtonColor: "#DD6B55",
    confirmButtonText: "Yes, delete it!"
  }, 
  deleteIt()
);

Sample Alert

How to SELECT by MAX(date)?

This would work perfectely, if you are using current timestamp

SELECT * FROM reports WHERE date_entered = (SELECT max(date_entered) FROM REPORTS)

This would also work, if you are not using current timestamp but you are using date and time column seperately

SELECT * FROM reports WHERE date_entered = (SELECT max(date_entered) FROM REPORTS) ORDER BY time DESC LIMIT 1

CSS Custom Dropdown Select that works across all browsers IE7+ FF Webkit

I was also having a similar problem. Finally found one solution at https://techmeals.com/fe/questions/htmlcss/4/How-to-customize-the-select-drop-down-in-css-which-works-for-all-the-browsers

Note:

1) For Firefox support there is special CSS handling for SELECT element's parent, please take a closer look.

2) Download the down.png from Down.png

CSS code

        /* For Firefox browser we need to style for SELECT element parent. */

        @-moz-document url-prefix() {

            /* Please note this is the parent of "SELECT" element */

            .select-example {   
                background: url('https://techmeals.com/external/images/down.png');
                background-color: #FFFFFF;
                border: 1px solid #9e9e9e;
                background-size: auto 6px;
                background-repeat: no-repeat;
                background-position: 96% 13px;
            }
        }

        /* IE specific styles */
        @media all and (-ms-high-contrast: none), (-ms-high-contrast: active) 
        {
                select.my-select-box {
                padding: 0 0 0 5px;
            }
        }

        /* IE specific styles */
        @supports (-ms-accelerator:true) {
                select.my-select-box {
                padding: 0 0 0 5px;
            }
        }

        select.my-select-box  {
            outline: none;
            background: #fff;
            -moz-appearance: window;
            -webkit-appearance: none;
            border-radius: 0px;
            text-overflow: "";
            background-image: url('https://techmeals.com/external/images/down.png');
            background-size: auto 6px;
            background-repeat: no-repeat;
            background-position: 96% 13px;
            cursor: pointer;
            height: 30px;
            width: 100%;
            border: 1px solid #9e9e9e;
            padding: 0 15px 0 5px;
            padding-right: 15px\9;      /* This will be apllied only to IE 7, IE 8 and IE 9 as */
            *padding-right: 15px;        /* This will be apllied only to IE 7 and below. */
            _padding-right: 15px;       /* This will be apllied only to IE 6 and below. */
        }

HTML code

    <div class="select-example">
        <select class="my-select-box">
            <option value="1">First Option</option>
            <option value="2">Second Option</option>
            <option value="3">Third Option</option>
            <option value="4">Fourth Option</option>
        </select>
    </div>

How can I copy data from one column to another in the same table?

UPDATE table_name SET
    destination_column_name=orig_column_name
WHERE condition_if_necessary

Replace X-axis with own values

Not sure if it's what you mean, but you can do this:

plot(1:10, xaxt = "n", xlab='Some Letters')
axis(1, at=1:10, labels=letters[1:10])

which then gives you the graph:

enter image description here

How can I check if a directory exists in a Bash shell script?

Using the -e check will check for files and this includes directories.

if [ -e ${FILE_PATH_AND_NAME} ]
then
    echo "The file or directory exists."
fi

how to File.listFiles in alphabetical order?

This is my code:

_x000D_
_x000D_
        try {_x000D_
            String folderPath = "../" + filePath.trim() + "/";_x000D_
            logger.info("Path: " + folderPath);_x000D_
            File folder = new File(folderPath);_x000D_
            File[] listOfFiles = folder.listFiles();_x000D_
            int length = listOfFiles.length;_x000D_
            logger.info("So luong files: " + length);_x000D_
            ArrayList<CdrFileBO> lstFile = new ArrayList< CdrFileBO>();_x000D_
_x000D_
            if (listOfFiles != null && length > 0) {_x000D_
                int count = 0;_x000D_
                for (int i = 0; i < length; i++) {_x000D_
                    if (listOfFiles[i].isFile()) {_x000D_
                        lstFile.add(new CdrFileBO(listOfFiles[i]));_x000D_
                    }_x000D_
                }_x000D_
                Collections.sort(lstFile);_x000D_
                for (CdrFileBO bo : lstFile) {_x000D_
                    //String newName = START_NAME + "_" + getSeq(SEQ_START) + "_" + DateSTR + ".s";_x000D_
                    String newName = START_NAME + DateSTR + getSeq(SEQ_START) + ".DAT";_x000D_
                    SEQ_START = SEQ_START + 1;_x000D_
                    bo.getFile().renameTo(new File(folderPath + newName));_x000D_
                    logger.info("newName: " + newName);_x000D_
                    logger.info("Next file: " + getSeq(SEQ_START));_x000D_
                }_x000D_
_x000D_
            }_x000D_
        } catch (Exception ex) {_x000D_
            logger.error(ex);_x000D_
            ex.printStackTrace();_x000D_
        }
_x000D_
_x000D_
_x000D_

Setting a system environment variable from a Windows batch file?

The XP Support Tools (which can be installed from your XP CD) come with a program called setx.exe:

C:\Program Files\Support Tools>setx /?

SETX: This program is used to set values in the environment
of the machine or currently logged on user using one of three modes.

1) Command Line Mode: setx variable value [-m]
   Optional Switches:
    -m  Set value in the Machine environment. Default is User.

...
For more information and example use: SETX -i

I think Windows 7 actually comes with setx as part of a standard install.

Replacing some characters in a string with another character

Here is a solution with shell parameter expansion that replaces multiple contiguous occurrences with a single _:

$ var=AxxBCyyyDEFzzLMN
$ echo "${var//+([xyz])/_}"
A_BC_DEF_LMN

Notice that the +(pattern) pattern requires extended pattern matching, turned on with

shopt -s extglob

Alternatively, with the -s ("squeeze") option of tr:

$ tr -s xyz _ <<< "$var"
A_BC_DEF_LMN

g++ ld: symbol(s) not found for architecture x86_64

I had a similar warning/error/failure when I was simply trying to make an executable from two different object files (main.o and add.o). I was using the command:

gcc -o exec main.o add.o

But my program is a C++ program. Using the g++ compiler solved my issue:

g++ -o exec main.o add.o

I was always under the impression that gcc could figure these things out on its own. Apparently not. I hope this helps someone else searching for this error.

JDBC connection to MSSQL server in windows authentication mode

If you want to do windows authentication, use the latest MS-JDBC driver and follow the instructions here:

https://msdn.microsoft.com/en-us/library/gg558122(v=sql.110).aspx

Delete rows from multiple tables using a single query (SQL Express 2005) with a WHERE condition

Use this in procedure

declare cu cursor for SELECT [name] FROM sys.Tables where [name] like 'tbl_%'
declare @table varchar(100)
declare @sql nvarchar(1000)

OPEN cu  
FETCH NEXT FROM cu INTO @table 

WHILE @@FETCH_STATUS = 0  
BEGIN  
    set @sql = N'delete from ' + @table
    EXEC sp_executesql @sql
    FETCH NEXT FROM cu INTO @table 
END   
CLOSE cu;  
DEALLOCATE cu;

Error: Execution failed for task ':app:clean'. Unable to delete file

Some times intermediates creates problem so delete it and Rebuild project

OR

simply run cmd command - > gradlew clean

in your project folder in work space (its work for me)

A SQL Query to select a string between two known strings

The problem is that the second part of your substring argument is including the first index. You need to subtract the first index from your second index to make this work.

SELECT SUBSTRING(@Text, CHARINDEX('the dog', @Text)
, CHARINDEX('immediately',@text) - CHARINDEX('the dog', @Text) + Len('immediately'))

Could not load type 'XXX.Global'

I fixed this error by simply switching from Debug to Release, launch program (It worked on release), then switch back to Debug.

I tried just about everything else, including restarting Visual Studio and nothing worked.

Saving an Object (Data persistence)

You could use the pickle module in the standard library. Here's an elementary application of it to your example:

import pickle

class Company(object):
    def __init__(self, name, value):
        self.name = name
        self.value = value

with open('company_data.pkl', 'wb') as output:
    company1 = Company('banana', 40)
    pickle.dump(company1, output, pickle.HIGHEST_PROTOCOL)

    company2 = Company('spam', 42)
    pickle.dump(company2, output, pickle.HIGHEST_PROTOCOL)

del company1
del company2

with open('company_data.pkl', 'rb') as input:
    company1 = pickle.load(input)
    print(company1.name)  # -> banana
    print(company1.value)  # -> 40

    company2 = pickle.load(input)
    print(company2.name) # -> spam
    print(company2.value)  # -> 42

You could also define your own simple utility like the following which opens a file and writes a single object to it:

def save_object(obj, filename):
    with open(filename, 'wb') as output:  # Overwrites any existing file.
        pickle.dump(obj, output, pickle.HIGHEST_PROTOCOL)

# sample usage
save_object(company1, 'company1.pkl')

Update

Since this is such a popular answer, I'd like touch on a few slightly advanced usage topics.

cPickle (or _pickle) vs pickle

It's almost always preferable to actually use the cPickle module rather than pickle because the former is written in C and is much faster. There are some subtle differences between them, but in most situations they're equivalent and the C version will provide greatly superior performance. Switching to it couldn't be easier, just change the import statement to this:

import cPickle as pickle

In Python 3, cPickle was renamed _pickle, but doing this is no longer necessary since the pickle module now does it automatically—see What difference between pickle and _pickle in python 3?.

The rundown is you could use something like the following to ensure that your code will always use the C version when it's available in both Python 2 and 3:

try:
    import cPickle as pickle
except ModuleNotFoundError:
    import pickle

Data stream formats (protocols)

pickle can read and write files in several different, Python-specific, formats, called protocols as described in the documentation, "Protocol version 0" is ASCII and therefore "human-readable". Versions > 0 are binary and the highest one available depends on what version of Python is being used. The default also depends on Python version. In Python 2 the default was Protocol version 0, but in Python 3.8.1, it's Protocol version 4. In Python 3.x the module had a pickle.DEFAULT_PROTOCOL added to it, but that doesn't exist in Python 2.

Fortunately there's shorthand for writing pickle.HIGHEST_PROTOCOL in every call (assuming that's what you want, and you usually do), just use the literal number -1 — similar to referencing the last element of a sequence via a negative index. So, instead of writing:

pickle.dump(obj, output, pickle.HIGHEST_PROTOCOL)

You can just write:

pickle.dump(obj, output, -1)

Either way, you'd only have specify the protocol once if you created a Pickler object for use in multiple pickle operations:

pickler = pickle.Pickler(output, -1)
pickler.dump(obj1)
pickler.dump(obj2)
   etc...

Note: If you're in an environment running different versions of Python, then you'll probably want to explicitly use (i.e. hardcode) a specific protocol number that all of them can read (later versions can generally read files produced by earlier ones).

Multiple Objects

While a pickle file can contain any number of pickled objects, as shown in the above samples, when there's an unknown number of them, it's often easier to store them all in some sort of variably-sized container, like a list, tuple, or dict and write them all to the file in a single call:

tech_companies = [
    Company('Apple', 114.18), Company('Google', 908.60), Company('Microsoft', 69.18)
]
save_object(tech_companies, 'tech_companies.pkl')

and restore the list and everything in it later with:

with open('tech_companies.pkl', 'rb') as input:
    tech_companies = pickle.load(input)

The major advantage is you don't need to know how many object instances are saved in order to load them back later (although doing so without that information is possible, it requires some slightly specialized code). See the answers to the related question Saving and loading multiple objects in pickle file? for details on different ways to do this. Personally I like @Lutz Prechelt's answer the best. Here's it adapted to the examples here:

class Company:
    def __init__(self, name, value):
        self.name = name
        self.value = value

def pickled_items(filename):
    """ Unpickle a file of pickled data. """
    with open(filename, "rb") as f:
        while True:
            try:
                yield pickle.load(f)
            except EOFError:
                break

print('Companies in pickle file:')
for company in pickled_items('company_data.pkl'):
    print('  name: {}, value: {}'.format(company.name, company.value))

How to remove all leading zeroes in a string

Assuming you want a run-on of three or more zeros to be removed and your example is one string:

    $test_str ="0002030050400000234892839000239074";
    $fixed_str = preg_replace('/000+/','',$test_str);

You can make the regex pattern fit what you need if my assumptions are off.

This help?

git stash and git pull

When you have changes on your working copy, from command line do:

git stash 

This will stash your changes and clear your status report

git pull

This will pull changes from upstream branch. Make sure it says fast-forward in the report. If it doesn't, you are probably doing an unintended merge

git stash pop

This will apply stashed changes back to working copy and remove the changes from stash unless you have conflicts. In the case of conflict, they will stay in stash so you can start over if needed.

if you need to see what is in your stash

git stash list

AttributeError: 'list' object has no attribute 'encode'

You need to do encode on tmp[0], not on tmp.

tmp is not a string. It contains a (Unicode) string.

Try running type(tmp) and print dir(tmp) to see it for yourself.

CertPathValidatorException : Trust anchor for certificate path not found - Retrofit Android

 Use the below code to solve the CertPathValidatorException issue.


 Retrofit retrofit = new Retrofit.Builder()
        .baseUrl(YOUR_BASE_URL)
        .client(getUnsafeOkHttpClient().build())
        .build();


  public static OkHttpClient.Builder getUnsafeOkHttpClient() {

    try {
        // Create a trust manager that does not validate certificate chains
        final TrustManager[] trustAllCerts = new TrustManager[]{
                new X509TrustManager() {
                    @Override
                    public void checkClientTrusted(java.security.cert.X509Certificate[] chain, String authType) throws CertificateException {
                    }

                    @Override
                    public void checkServerTrusted(java.security.cert.X509Certificate[] chain, String authType) throws CertificateException {
                    }

                    @Override
                    public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                        return new java.security.cert.X509Certificate[]{};
                    }
                }
        };

        // Install the all-trusting trust manager
        final SSLContext sslContext = SSLContext.getInstance("SSL");
        sslContext.init(null, trustAllCerts, new java.security.SecureRandom());

        // Create an ssl socket factory with our all-trusting manager
        final SSLSocketFactory sslSocketFactory = sslContext.getSocketFactory();

        OkHttpClient.Builder builder = new OkHttpClient.Builder();
        builder.sslSocketFactory(sslSocketFactory, (X509TrustManager) trustAllCerts[0]);
        builder.hostnameVerifier(new HostnameVerifier() {
            @Override
            public boolean verify(String hostname, SSLSession session) {
                return true;
            }
        });
        return builder;
    } catch (Exception e) {
        throw new RuntimeException(e);
    }
}

For more details visit https://mobikul.com/android-retrofit-handling-sslhandshakeexception/

iTerm 2: How to set keyboard shortcuts to jump to beginning/end of line?

I see there's a lot of good answers already, but this should provide the closest to native OSX functionality as possible in more than just your shell. I verified that this works in ZSH, Bash, node, python -i, iex and irb/pry sessions (using rb-readline gem for readline, but should work for all).

Open the iTerm preferences ?+, and navigate to the Profiles tab (the Keys tab can be used, but adding keybinding to your profile allows you to save your profile and sync it to multiple computers) and keys sub-tab and enter the following:

Delete all characters left of the cursor

?+?Delete Send Hex Codes:

0x15 More compatible, but functionality sometimes is to delete the entire line rather than just the characters to the left of the curser. I personally use this and then overwrite my zsh bindkey for ^U to delete only stuff to the left of the cursor (see below).

or

0x18 0x7f Less compatible, doesn't work in node and won't work in zsh by default, see below to fix zsh (bash/irb/pry should be fine), performs desired functionality when it does work.

Delete all characters right of the cursor

?+fn+?Delete or ?+Delete? Send Hex Codes: 0x0b

Delete one word to left of cursor

?+?Delete Send Hex Codes:

0x1b 0x08 Breaks in Elixir's IEX, seems to work fine everywhere else

or

0x17 Works everywhere, but doesn't stop at normal word breaks in IRB and will instead delete until it sees a literal space.

Delete one word to right of cursor

?+fn?Delete or ?+Delete? Send Hex Codes: 0x1b 0x64

Move cursor to the front of line

?+? Send Hex Codes: 0x01

Move cursor to the end of line

?+? Send Hex Codes: 0x05

Move cursor one word left

?+? Send Hex Codes: 0x1b 0x62

Move cursor one word right

?+? Send Hex Codes: 0x1b 0x66

Undo

?+z Send Hex Codes: 0x1f

Redo typically not bound in bash, zsh or readline, so we can set it to a unused hexcode which we can then fix in zsh

?+?+Z or ?+y Send Hex Codes: 0x18 0x1f

Now how to fix any that don't work

For zsh, you can setup binding for the not yet functional ?+?Delete and ?+?+Z/?+y by running:

# changes hex 0x15 to delete everything to the left of the cursor,
# rather than the whole line
$ echo 'bindkey "^U" backward-kill-line' >> ~/.zshrc

# binds hex 0x18 0x7f with deleting everything to the left of the cursor
$ echo 'bindkey "^X\\x7f" backward-kill-line' >> ~/.zshrc

# adds redo
$ echo 'bindkey "^X^_" redo' >> ~/.zshrc

# reload your .zshrc for changes to take effect
$ source ~/.zshrc

I'm unable to find a solution for adding redo in bash or readline, so if anyone know a solution for either of those, please comment below and I'll try to add them in.

For anyone looking for the lookup table on how to convert key sequences to hex, I find this table very helpful.

How do you replace all the occurrences of a certain character in a string?

I would use the translate method without translation table. It deletes the letters in second argument in recent Python versions.

def remove_chars(line):
    line7=line[7].translate(None,'abcd')
    return line[:7]+[line7]+line[8:]

line= ['ad','da','sdf','asd',
        '3424','342sfas','asdfaf','sdfa',
        'afase']
print line[7]
line = remove_chars(line)
print line[7]

IOS 7 Navigation Bar text and arrow color

Behavior from some of the properties of UINavigationBar has changed from iOS 7. You can see in the image shown below :

enter image description here


Two beautiful links I'd like to share with you. For more details you can go through these links :

  1. iOS 7 UI Transition Guide.
  2. How to Update Your App for iOS 7.

Apple Documentation for barTintColor says :

This color is made translucent by default unless you set the translucent property to NO.

Sample Code :

self.navigationController.navigationBar.barTintColor = [UIColor blackColor];
self.navigationController.navigationBar.tintColor = [UIColor whiteColor];
[self.navigationController.navigationBar 
 setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor whiteColor]}];
self.navigationController.navigationBar.translucent = NO;

Understanding Matlab FFT example

There are some misconceptions here.

Frequencies above 500 can be represented in an FFT result of length 1000. Unfortunately these frequencies are all folded together and mixed into the first 500 FFT result bins. So normally you don't want to feed an FFT a signal containing any frequencies at or above half the sampling rate, as the FFT won't care and will just mix the high frequencies together with the low ones (aliasing) making the result pretty much useless. That's why data should be low-pass filtered before being sampled and fed to an FFT.

The FFT returns amplitudes without frequencies because the frequencies depend, not just on the length of the FFT, but also on the sample rate of the data, which isn't part of the FFT itself or it's input. You can feed the same length FFT data at any sample rate, as thus get any range of frequencies out of it.

The reason the result plots ends at 500 is that, for any real data input, the frequencies above half the length of the FFT are just mirrored repeats (complex conjugated) of the data in the first half. Since they are duplicates, most people just ignore them. Why plot duplicates? The FFT calculates the other half of the result for people who feed the FFT complex data (with both real and imaginary components), which does create two different halves.

Detecting request type in PHP (GET, POST, PUT or DELETE)

By using

$_SERVER['REQUEST_METHOD']

Example

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
     // The request is using the POST method
}

For more details please see the documentation for the $_SERVER variable.

How can I write variables inside the tasks file in ansible

In Your example, apache.yml is tasklist, but not playbook

In depends on desired architecture, You can do one of:

  1. Convert apache.yml to role. Then define tasks in roles/apache/tasks/mail.yml and variables in roles/apache/defaults/mail.yml (vars in defaults can be overriden when role applied)

  2. Set vars in play.yml playbook

play.yml

---
- hosts: 127.0.0.1
  connection: local
  sudo: false

  vars:
    url: czxcxz

  tasks:
     - include: apache.yml

apache.yml

- name: Download apache
  shell: wget {{url}} 

How do I flush the cin buffer?

Easiest way:

cin.seekg(0,ios::end);
cin.clear();

It just positions the cin pointer at the end of the stdin stream and cin.clear() clears all error flags such as the EOF flag.

Remove columns from DataTable in C#

To remove all columns after the one you want, below code should work. It will remove at index 10 (remember Columns are 0 based), until the Column count is 10 or less.

DataTable dt;
int desiredSize = 10;

while (dt.Columns.Count > desiredSize)
{
   dt.Columns.RemoveAt(desiredSize);
}

Executing Shell Scripts from the OS X Dock?

I know this is old but in case it is helpful to others:

If you need to run a script and want the terminal to pop up so you can see the results you can do like Abyss Knight said and change the extension to .command. If you double click on it it will open a terminal window and run.

I however needed this to run from automator or appleScript. So to get this to open a new terminal the command I ran from "run shell script" was "open myShellScript.command" and it opened in a new terminal.

MassAssignmentException in Laravel

This is not a good way when you want to seeding database.
Use faker instead of hard coding, and before all this maybe it's better to truncate tables.

Consider this example :

    // Truncate table.  
    DB::table('users')->truncate();

    // Create an instance of faker.
    $faker = Faker::create();

    // define an array for fake data.
    $users = [];

    // Make an array of 500 users with faker.
    foreach (range(1, 500) as $index)
    {
        $users[] = [
            'group_id' => rand(1, 3),
            'name' => $faker->name,
            'company' => $faker->company,
            'email' => $faker->email,
            'phone' => $faker->phoneNumber,
            'address' => "{$faker->streetName} {$faker->postCode} {$faker->city}",
            'about' => $faker->sentence($nbWords = 20, $variableNbWords = true),
            'created_at' => new DateTime,
            'updated_at' => new DateTime,
        ];
    }

    // Insert into database.
    DB::table('users')->insert($users);

Selecting with complex criteria from pandas.DataFrame

You can use pandas it has some built in functions for comparison. So if you want to select values of "A" that are met by the conditions of "B" and "C" (assuming you want back a DataFrame pandas object)

df[['A']][df.B.gt(50) & df.C.ne(900)]

df[['A']] will give you back column A in DataFrame format.

pandas 'gt' function will return the positions of column B that are greater than 50 and 'ne' will return the positions not equal to 900.

Convert InputStream to BufferedReader

BufferedReader can't wrap an InputStream directly. It wraps another Reader. In this case you'd want to do something like:

BufferedReader br = new BufferedReader(new InputStreamReader(is, "UTF-8"));

Latest jQuery version on Google's CDN

Here's an updated link.

There are updated now and then, just keep checking for the latest version.

What is the difference between linear regression and logistic regression?

| Basis                                                           | Linear                                                                         | Logistic                                                                                                            |
|-----------------------------------------------------------------|--------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------|
| Basic                                                           | The data is modelled using a straight line.                                    | The probability of some obtained event is represented as a linear function of a combination of predictor variables. |
| Linear relationship between dependent and independent variables | Is required                                                                    | Not required                                                                                                        |
| The independent variable                                        | Could be correlated with each other. (Specially in multiple linear regression) | Should not be correlated with each other (no multicollinearity exist).                                              |

How to write file in UTF-8 format?

file_get_contents / file_put_contents will not magically convert encoding.

You have to convert the string explicitly; for example with iconv() or mb_convert_encoding().

Try this:

$data = file_get_contents($npath);
$data = mb_convert_encoding($data, 'UTF-8', 'OLD-ENCODING');
file_put_contents('tempfolder/'.$a, $data);

Or alternatively, with PHP's stream filters:

$fd = fopen($file, 'r');
stream_filter_append($fd, 'convert.iconv.UTF-8/OLD-ENCODING');
stream_copy_to_stream($fd, fopen($output, 'w'));

When to use 'npm start' and when to use 'ng serve'?

npm start will run whatever you have defined for the start command of the scripts object in your package.json file.

So if it looks like this:

"scripts": {
  "start": "ng serve"
}

Then npm start will run ng serve.

Forcing to download a file using PHP

This means that your browser can handle this file type.

If you don't like it, the easiest method would be offering ZIP files. Everyone can handle ZIP files, and they are downloadable by default.

How to convert entire dataframe to numeric while preserving decimals?

You might need to do some checking. You cannot safely convert factors directly to numeric. as.character must be applied first. Otherwise, the factors will be converted to their numeric storage values. I would check each column with is.factor then coerce to numeric as necessary.

df1[] <- lapply(df1, function(x) {
    if(is.factor(x)) as.numeric(as.character(x)) else x
})
sapply(df1, class)
#         a         b 
# "numeric" "numeric" 

AngularJS $watch window resize inside directive

You can listen resize event and fire where some dimension change

directive

(function() {
'use strict';

    angular
    .module('myApp.directives')
    .directive('resize', ['$window', function ($window) {
        return {
            link: link,
            restrict: 'A'
        };

        function link(scope, element, attrs){
            scope.width = $window.innerWidth;
            function onResize(){
                // uncomment for only fire when $window.innerWidth change   
                // if (scope.width !== $window.innerWidth)
                {
                    scope.width = $window.innerWidth;
                    scope.$digest();
                }
            };

            function cleanUp() {
                angular.element($window).off('resize', onResize);
            }

            angular.element($window).on('resize', onResize);
            scope.$on('$destroy', cleanUp);
        }
    }]);
})();

In html

<div class="row" resize> ,
    <div class="col-sm-2 col-xs-6" ng-repeat="v in tag.vod"> 
        <h4 ng-bind="::v.known_as"></h4>
    </div> 
</div> 

Controller :

$scope.$watch('width', function(old, newv){
     console.log(old, newv);
 })

Replace \n with <br />

thatLine = thatLine.replace('\n', '<br />')

str.replace() returns a copy of the string, it doesn't modify the string you pass in.

Write to file, but overwrite it if it exists

If you have output that can have errors, you may want to use an ampersand and a greater than, as follows:

my_task &> 'Users/Name/Desktop/task_output.log' this will redirect both stderr and stdout to the log file (instead of stdout only).

Use jQuery to navigate away from page

window.location.href = "/somewhere/else";

Can I rollback a transaction I've already committed? (data loss)

No, you can't undo, rollback or reverse a commit.

STOP THE DATABASE!

(Note: if you deleted the data directory off the filesystem, do NOT stop the database. The following advice applies to an accidental commit of a DELETE or similar, not an rm -rf /data/directory scenario).

If this data was important, STOP YOUR DATABASE NOW and do not restart it. Use pg_ctl stop -m immediate so that no checkpoint is run on shutdown.

You cannot roll back a transaction once it has commited. You will need to restore the data from backups, or use point-in-time recovery, which must have been set up before the accident happened.

If you didn't have any PITR / WAL archiving set up and don't have backups, you're in real trouble.

Urgent mitigation

Once your database is stopped, you should make a file system level copy of the whole data directory - the folder that contains base, pg_clog, etc. Copy all of it to a new location. Do not do anything to the copy in the new location, it is your only hope of recovering your data if you do not have backups. Make another copy on some removable storage if you can, and then unplug that storage from the computer. Remember, you need absolutely every part of the data directory, including pg_xlog etc. No part is unimportant.

Exactly how to make the copy depends on which operating system you're running. Where the data dir is depends on which OS you're running and how you installed PostgreSQL.

Ways some data could've survived

If you stop your DB quickly enough you might have a hope of recovering some data from the tables. That's because PostgreSQL uses multi-version concurrency control (MVCC) to manage concurrent access to its storage. Sometimes it will write new versions of the rows you update to the table, leaving the old ones in place but marked as "deleted". After a while autovaccum comes along and marks the rows as free space, so they can be overwritten by a later INSERT or UPDATE. Thus, the old versions of the UPDATEd rows might still be lying around, present but inaccessible.

Additionally, Pg writes in two phases. First data is written to the write-ahead log (WAL). Only once it's been written to the WAL and hit disk, it's then copied to the "heap" (the main tables), possibly overwriting old data that was there. The WAL content is copied to the main heap by the bgwriter and by periodic checkpoints. By default checkpoints happen every 5 minutes. If you manage to stop the database before a checkpoint has happened and stopped it by hard-killing it, pulling the plug on the machine, or using pg_ctl in immediate mode you might've captured the data from before the checkpoint happened, so your old data is more likely to still be in the heap.

Now that you have made a complete file-system-level copy of the data dir you can start your database back up if you really need to; the data will still be gone, but you've done what you can to give yourself some hope of maybe recovering it. Given the choice I'd probably keep the DB shut down just to be safe.

Recovery

You may now need to hire an expert in PostgreSQL's innards to assist you in a data recovery attempt. Be prepared to pay a professional for their time, possibly quite a bit of time.

I posted about this on the Pg mailing list, and ?????? ?????? linked to depesz's post on pg_dirtyread, which looks like just what you want, though it doesn't recover TOASTed data so it's of limited utility. Give it a try, if you're lucky it might work.

See: pg_dirtyread on GitHub.

I've removed what I'd written in this section as it's obsoleted by that tool.

See also PostgreSQL row storage fundamentals

Prevention

See my blog entry Preventing PostgreSQL database corruption.


On a semi-related side-note, if you were using two phase commit you could ROLLBACK PREPARED for a transction that was prepared for commit but not fully commited. That's about the closest you get to rolling back an already-committed transaction, and does not apply to your situation.

Performance differences between ArrayList and LinkedList

I want to add an additional piece of information her about the difference in performance.

We already know that due to the fact that ArrayList implementation is backed by an Object[] it's supports random access and dynamic resizing and LinkedList implementation uses references to head and tail to navigate it. It has no random access capabilities, but it supports dynamic resizing as well.

The first thing is that with an ArrayList, you can immediately access the index, whereas with a LinkedList, you have iterate down the object chain.

Secondly, inserting into ArrayList is generally slower because it has to grow once you hit its boundaries. It will have to create a new bigger array, and copy data from the original one.

But the interesting thing is that when you create an ArrayList that is already huge enough to fit all your inserts it will obviously not involve any array copying operations. Adding to it will be even faster than with LinkedList because LinkedList will have to deal with its pointers, while huge ArrayList just sets value at given index.

enter image description here

Check out for more ArrayList and LinkedList differences.

Session variables in ASP.NET MVC

Great answers from the guys but I would caution you against always relying on the Session. It is quick and easy to do so, and of course would work but would not be great in all cicrumstances.

For example if you run into a scenario where your hosting doesn't allow session use, or if you are on a web farm, or in the example of a shared SharePoint application.

If you wanted a different solution you could look at using an IOC Container such as Castle Windsor, creating a provider class as a wrapper and then keeping one instance of your class using the per request or session lifestyle depending on your requirements.

The IOC would ensure that the same instance is returned each time.

More complicated yes, if you need a simple solution just use the session.

Here are some implementation examples below out of interest.

Using this method you could create a provider class along the lines of:

public class CustomClassProvider : ICustomClassProvider
{
    public CustomClassProvider(CustomClass customClass)
    { 
        CustomClass = customClass;
    }

    public string CustomClass { get; private set; }
}

And register it something like:

public void Install(IWindsorContainer container, IConfigurationStore store)
{
    container.Register(
            Component.For<ICustomClassProvider>().UsingFactoryMethod(
                () => new CustomClassProvider(new CustomClass())).LifestylePerWebRequest());
    }

AngularJS : How do I switch views from a controller function?

I've got an example working.

Here's how my doc looks:

<html>
<head>
    <link rel="stylesheet" href="css/main.css">
    <script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.0.3/angular.min.js"></script>
    <script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.0.3/angular-resource.min.js"></script>
    <script src="js/app.js"></script>
    <script src="controllers/ctrls.js"></script>
</head>
<body ng-app="app">
    <div id="contnr">
        <ng-view></ng-view>
    </div>
</body>
</html>

Here's what my partial looks like:

<div id="welcome" ng-controller="Index">
    <b>Welcome! Please Login!</b>
    <form ng-submit="auth()">
        <input class="input login username" type="text" placeholder="username" /><br>
        <input class="input login password" type="password" placeholder="password" /><br>
        <input class="input login submit" type="submit" placeholder="login!" />
    </form>
</div>

Here's what my Ctrl looks like:

app.controller('Index', function($scope, $routeParams, $location){
    $scope.auth = function(){
        $location.url('/map');
    };
});

app is my module:

var app = angular.module('app', ['ngResource']).config(function($routeProvider)...

Hope this is helpful!

Mapping US zip code to time zone

If you want, you can also get a feel for the timezone by asking the browser Josh Fraser has a nice write up on it here

var rightNow = new Date();
var jan1 = new Date(rightNow.getFullYear(), 0, 1, 0, 0, 0, 0);
var temp = jan1.toGMTString();
var jan2 = new Date(temp.substring(0, temp.lastIndexOf(" ")-1));
var std_time_offset = (jan1 - jan2) / (1000 * 60 * 60);

The second thing that you need to know is whether the location observes daylight savings time (DST) or not. Since DST is always observed during the summer, we can compare the time offset between two dates in January, to the time offset between two dates in June. If the offsets are different, then we know that the location observes DST. If the offsets are the same, then we know that the location DOES NOT observe DST.

var june1 = new Date(rightNow.getFullYear(), 6, 1, 0, 0, 0, 0);
temp = june1.toGMTString();
var june2 = new Date(temp.substring(0, temp.lastIndexOf(" ")-1));
var daylight_time_offset = (june1 - june2) / (1000 * 60 * 60);
var dst;
if (std_time_offset == daylight_time_offset) {
    dst = "0"; // daylight savings time is NOT observed
} else {
    dst = "1"; // daylight savings time is observed
}

All credit for this goes to Josh Fraser.

This might help you with customers outside the US, and it might complement your zip approach.

Here is a SO questions that touch on getting the timezone from javascript

Linker command failed with exit code 1 - duplicate symbol __TMRbBp

I had similar kind of problem when I added a framework to my project.

I have resolved the issue by removing the framework and again adding the framework to the project by dragging and dropping the framework file to the projects frameworks folder and selecting the Copy items if needed option.enter image description here

VBScript - How to make program wait until process has finished?

strComputer = "."
Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2:Win32_Process")
objWMIService.Create "notepad.exe", null, null, intProcessID
Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
Set colMonitoredProcesses = objWMIService.ExecNotificationQuery _
    ("Select * From __InstanceDeletionEvent Within 1 Where TargetInstance ISA 'Win32_Process'")
Do Until i = 1
    Set objLatestProcess = colMonitoredProcesses.NextEvent
    If objLatestProcess.TargetInstance.ProcessID = intProcessID Then
        i = 1
    End If
Loop
Wscript.Echo "Notepad has been terminated."

Javascript Date: next month

ah, the beauty of ternaries:

const now = new Date();
const expiry = now.getMonth() == 11 ? new Date(now.getFullYear()+1, 0 , 1) : new Date(now.getFullYear(), now.getMonth() + 1, 1);

just a simpler version of the solution provided by @paxdiablo and @Tom

C++: How to round a double to an int?

Casting to an int truncates the value. Adding 0.5 causes it to do proper rounding.

int y = (int)(x + 0.5);

How do I use CREATE OR REPLACE?

CREATE OR REPLACE can only be used on functions, procedures, types, views, or packages - it will not work on tables.

Error HRESULT E_FAIL has been returned from a call to a COM component VS2012 when debugging

I just encountered this same issue. Turned out the Project URL on the Web property sheet was malformed.

I had just removed a port number, forgot to delete the preceding colon and tried running with: http://localhost:/XYZ

Seems like lots of different issues result in this error message.

WPF MVVM: How to close a window

Simple approach is close window on saveComand Implementation. Use below code to close window.

Application.Current.Windows[1].Close();

It will close the child window.

C# how to convert File.ReadLines into string array?

string[] lines = File.ReadLines("c:\\file.txt").ToArray();

Although one wonders why you'll want to do that when ReadAllLines works just fine.

Or perhaps you just want to enumerate with the return value of File.ReadLines:

var lines = File.ReadAllLines("c:\\file.txt");
foreach (var line in lines)
{
    Console.WriteLine("\t" + line);
}

What is the { get; set; } syntax in C#?

That is an Auto-Implemented Property. It's basically a shorthand way of creating properties for a class in C#, without having to define private variables for them. They are normally used when no extra logic is required when getting or setting the value of a variable.

You can read more on MSDN's Auto-Implemented Properties Programming Guide.

Download multiple files as a zip-file using php

Create a zip file, then download the file, by setting the header, read the zip contents and output the file.

http://www.php.net/manual/en/function.ziparchive-addfile.php

http://php.net/manual/en/function.header.php

ojdbc14.jar vs. ojdbc6.jar

Actually, ojdbc14.jar doesn't really say anything about the real version of the driver (see JDBC Driver Downloads), except that it predates Oracle 11g. In such situation, you should provide the exact version.

Anyway, I think you'll find some explanation in What is going on with DATE and TIMESTAMP? In short, they changed the behavior in 9.2 drivers and then again in 11.1 drivers.

This might explain the differences you're experiencing (and I suggest using the most recent version i.e. the 11.2 drivers).

how to convert string into time format and add two hours

Basic program of adding two times:
You can modify hour:min:sec as per your need using if else.
This program shows you how you can add values from two objects and return in another object.

class demo
{private int hour,min,sec;
    void input(int hour,int min,int sec)
    {this.hour=hour;
    this.min=min;
    this.sec=sec;

    }
    demo add(demo d2)//demo  because we are returning object
    {   demo obj=new demo();
    obj.hour=hour+d2.hour;
    obj.min=min+d2.min;
    obj.sec=sec+d2.sec;
    return obj;//Returning object and later on it gets allocated to demo d3                    
    }
    void display()
    {
        System.out.println(hour+":"+min+":"+sec);
    }
    public static  void main(String args[])
    {
        demo d1=new demo();
        demo d2=new demo();
        d1.input(2, 5, 10);
        d2.input(3, 3, 3);
        demo d3=d1.add(d2);//Note another object is created
        d3.display();


    }

}

Modified Time Addition Program

class demo {private int hour,min,sec; void input(int hour,int min,int sec) {this.hour=(hour>12&&hour<24)?(hour-12):hour; this.min=(min>60)?0:min; this.sec=(sec>60)?0:sec; } demo add(demo d2) { demo obj=new demo(); obj.hour=hour+d2.hour; obj.min=min+d2.min; obj.sec=sec+d2.sec; if(obj.sec>60) {obj.sec-=60; obj.min++; } if(obj.min>60) { obj.min-=60; obj.hour++; } return obj; } void display() { System.out.println(hour+":"+min+":"+sec); } public static void main(String args[]) { demo d1=new demo(); demo d2=new demo(); d1.input(12, 55, 55); d2.input(12, 7, 6); demo d3=d1.add(d2); d3.display(); } }

OpenCV NoneType object has no attribute shape

I just meet a same problem. I solve it by updating the newest version of OpenCV. It works well with me. Hope it is also ok with you.

The conversion of the varchar value overflowed an int column

Declare @phoneNumber int

select @phoneNumber=Isnull('08041159620',0);

Give error :

The conversion of the varchar value '8041159620' overflowed an int column.: select cast('8041159620' as int)

AS

Integer is defined as :

Integer (whole number) data from -2^31 (-2,147,483,648) through 2^31 - 1 (2,147,483,647). Storage size is 4 bytes. The SQL-92 synonym for int is integer.

Solution

Declare @phoneNumber bigint

Reference

How can I resize an image dynamically with CSS as the browser width/height changes?

Are you using jQuery?

Because I did a quickly search on the jQuery plugings and they seem to have some plugin to do this, check this one, should work:

http://plugins.jquery.com/project/jquery-afterresize

EDIT:

This is the CSS solution, I just add a style="width: 100%", and works for me at least in chrome and Safari. I dont have ie, so just test there, and let me know, here is the code:

            <div id="gallery" style="width: 100%">
                <img src="images/fullsize.jpg" alt="" id="fullsize" />
                <a href="#" id="prev">prev</a>
                <a href="#" id="next">next</a>
            </div>

Want to make Font Awesome icons clickable

In your css add a class:

.fa-clickable {
    cursor:pointer;
    outline:none;
}

Then add the class to the clickable fontawesome icons (also an id so you can differentiate the clicks):

 <i class="fa fa-dribbble fa-4x fa-clickable" id="epd-dribble"></i>
 <i class="fa fa-behance-square fa-4x fa-clickable" id="epd-behance"></i>
 <i class="fa fa-linkedin-square fa-4x fa-clickable" id="epd-linkedin"></i>
 <i class="fa fa-twitter-square fa-4x fa-clickable" id="epd-twitter"></i>
 <i class="fa fa-facebook-square fa-4x fa-clickable" id="epd-facebook"></i>

Then add a handler in your jQuery

$(document).on("click", "i", function(){
    switch (this.id) {
        case "epd-dribble":
            // do stuff
            break;
        // add additional cases
    }
});

How to fix "Only one expression can be specified in the select list when the subquery is not introduced with EXISTS" error?

Try this:

 Select 
    Id, 
    Salt, 
    Password, 
    BannedEndDate, 
    (Select Count(*) 
        From LoginFails 
        Where username = '" + LoginModel.Username + "' And IP = '" + Request.ServerVariables["REMOTE_ADDR"] + "')
 From Users 
 Where username = '" + LoginModel.Username + "'

And I recommend you strongly to use parameters in your query to avoid security risks with sql injection attacks!

Hope that helps!

Create view with primary key?

I got the error "The table/view 'dbo.vMyView' does not have a primary key defined" after I created a view in SQL server query designer. I solved the problem by using ISNULL on a column to force entity framework to use it as a primary key. You might have to restart visual studio to get the warnings to go away.

CREATE VIEW [dbo].[vMyView]
AS
SELECT ISNULL(Id, -1) AS IdPrimaryKey, Name
FROM  dbo.MyTable

Display XML content in HTML page

If you treat the content as text, not HTML, then DOM operations should cause the data to be properly encoded. Here's how you'd do it in jQuery:

$('#container').text(xmlString);

Here's how you'd do it with standard DOM methods:

document.getElementById('container')
        .appendChild(document.createTextNode(xmlString));

If you're placing the XML inside of HTML through server-side scripting, there are bound to be encoding functions to allow you to do that (if you add what your server-side technology is, we can give you specific examples of how you'd do it).

Optimal way to concatenate/aggregate strings

You can use += to concatenate strings, for example:

declare @test nvarchar(max)
set @test = ''
select @test += name from names

if you select @test, it will give you all names concatenated