Programs & Examples On #Css parsing

CSS is the abbreviation of Cascading Style Sheets

'NOT NULL constraint failed' after adding to models.py

if the zipcode field is not a required field then add null=True and blank=True, then run makemigrations and migrate command to successfully reflect the changes in the database.

How to debug Ruby scripts

  1. In Ruby:

    ruby -rdebug myscript.rb 
    

    then,

    • b <line>: put break-point
    • and n(ext) or s(tep) and c(ontinue)
    • p(uts) for display

    (like perl debug)

  2. In Rails: Launch the server with

    script/server --debugger
    

    and add debugger in the code.

Obtain smallest value from array in Javascript?

function tinyFriends() {
    let myFriends = ["Mukit", "Ali", "Umor", "sabbir"]
    let smallestFridend = myFriends[0];
    for (i = 0; i < myFriends.length; i++) {
        if (myFriends[i] < smallestFridend) {
            smallestFridend = myFriends[i];
        }
    }
    return smallestFridend   
}

Two values from one input in python?

You have to use the split() method which splits the input into two different inputs. Whatever you pass into the split is looked for and the input is split from there. In most cases its the white space.

For example, You give the input 23 24 25. You expect 3 different inputs like

num1 = 23
num2 = 24
num3 = 25

So in Python, You can do

num1,num2,num3 = input().split(" ")

Set title background color

There is another way to change the background color, however it is a hack and might fail on future versions of Android if the View hierarchy of the Window and its title is changed. However, the code won't crash, just miss setting the wanted color, in such a case.

In your Activity, like onCreate, do:

View titleView = getWindow().findViewById(android.R.id.title);
if (titleView != null) {
  ViewParent parent = titleView.getParent();
  if (parent != null && (parent instanceof View)) {
    View parentView = (View)parent;
    parentView.setBackgroundColor(Color.rgb(0x88, 0x33, 0x33));
  }
}

when I run mockito test occurs WrongTypeOfReturnValue Exception

I got this issue WrongTypeOfReturnValue because I mocked a method returning a java.util.Optional; with a com.google.common.base.Optional; due to my formatter automatically adding missing imports.

Mockito was just saying me that "method something() should return Optional"...

How Can I Override Style Info from a CSS Class in the Body of a Page?

Either use the style attribute to add CSS inline on your divs, e.g.:

<div style="color:red"> ... </div>

... or create your own style sheet and reference it after the existing stylesheet then your style sheet should take precedence.

... or add a <style> element in the <head> of your HTML with the CSS you need, this will take precedence over an external style sheet.

You can also add !important after your style values to override other styles on the same element.

Update

Use one of my suggestions above and target the span of class style21, rather than the containing div. The style you are applying on the containing div will not be inherited by the span as it's color is set in the style sheet.

Does MS Access support "CASE WHEN" clause if connect with ODBC?

I have had to use a multiple IIF statement to create a similar result in ACCESS SQL.

IIf([refi type] Like "FHA ST*","F",IIf([refi type]="VA IRRL","V"))

All remaining will stay Null.

How can I delete all Git branches which have been merged?

You can use git-del-br tool.

git-del-br -a

You can install it via pip using

pip install git-del-br

P.S: I am the author of the tool. Any suggestions/feedback are welcome.

initializing a boolean array in java

The main difference is that Boolean is an object and boolean is an primitive.

  • Object default value is null;
  • boolean default value is false;

Python Array with String Indices

Even better, try an OrderedDict (assuming you want something like a list). Closer to a list than a regular dict since the keys have an order just like list elements have an order. With a regular dict, the keys have an arbitrary order.

Note that this is available in Python 3 and 2.7. If you want to use with an earlier version of Python you can find installable modules to do that.

@RequestBody and @ResponseBody annotations in Spring

@RequestBody : Annotation indicating a method parameter should be bound to the body of the HTTP request.

For example:

@RequestMapping(path = "/something", method = RequestMethod.PUT)
public void handle(@RequestBody String body, Writer writer) throws IOException {
    writer.write(body);
}

@ResponseBody annotation can be put on a method and indicates that the return type should be written straight to the HTTP response body (and not placed in a Model, or interpreted as a view name).

For example:

@RequestMapping(path = "/something", method = RequestMethod.PUT)
public  @ResponseBody String helloWorld() {
    return "Hello World";
}  

Alternatively, we can use @RestController annotation in place of @Controller annotation. This will remove the need to using @ResponseBody.

for more details

How to trigger SIGUSR1 and SIGUSR2?

They are user-defined signals, so they aren't triggered by any particular action. You can explicitly send them programmatically:

#include <signal.h>

kill(pid, SIGUSR1);

where pid is the process id of the receiving process. At the receiving end, you can register a signal handler for them:

#include <signal.h>

void my_handler(int signum)
{
    if (signum == SIGUSR1)
    {
        printf("Received SIGUSR1!\n");
    }
}

signal(SIGUSR1, my_handler);

How to get the exact local time of client?

Nowadays you can get correct timezone of a user having just one line of code:

const timezone = Intl.DateTimeFormat().resolvedOptions().timeZone;

source: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DateTimeFormat/resolvedOptions

You can then use moment-timezone to parse timezone like:

const currentTime = moment().tz(timezone).format();

How to continue a Docker container which has exited

docker start `docker ps -a | awk '{print $1}'`

This will start up all the containers that are in the 'Exited' state

Convert absolute path into relative path given a current directory using Bash

Using realpath from GNU coreutils 8.23 is the simplest, I think:

$ realpath --relative-to="$file1" "$file2"

For example:

$ realpath --relative-to=/usr/bin/nmap /tmp/testing
../../../tmp/testing

.NET data structures: ArrayList, List, HashTable, Dictionary, SortedList, SortedDictionary -- Speed, memory, and when to use each?

Here are a few general tips for you:

  • You can use foreach on types that implement IEnumerable. IList is essentially an IEnumberable with Count and Item (accessing items using a zero-based index) properties. IDictionary on the other hand means you can access items by any-hashable index.

  • Array, ArrayList and List all implement IList. Dictionary, SortedDictionary, and Hashtable implement IDictionary.

  • If you are using .NET 2.0 or higher, it is recommended that you use generic counterparts of mentioned types.

  • For time and space complexity of various operations on these types, you should consult their documentation.

  • .NET data structures are in System.Collections namespace. There are type libraries such as PowerCollections which offer additional data structures.

  • To get a thorough understanding of data structures, consult resources such as CLRS.

MySQL: Large VARCHAR vs. TEXT?

Disclaimer: I'm not a MySQL expert ... but this is my understanding of the issues.

I think TEXT is stored outside the mysql row, while I think VARCHAR is stored as part of the row. There is a maximum row length for mysql rows .. so you can limit how much other data you can store in a row by using the VARCHAR.

Also due to VARCHAR forming part of the row, I suspect that queries looking at that field will be slightly faster than those using a TEXT chunk.

How to create a fix size list in python?

Note also that when you used arrays in C++ you might have had somewhat different needs, which are solved in different ways in Python:

  1. You might have needed just a collection of items; Python lists deal with this usecase just perfectly.
  2. You might have needed a proper array of homogenous items. Python lists are not a good way to store arrays.

Python solves the need in arrays by NumPy, which, among other neat things, has a way to create an array of known size:

from numpy import *

l = zeros(10)

Find something in column A then show the value of B for that row in Excel 2010

Guys Its very interesting to know that many of us face the problem of replication of lookup value while using the Vlookup/Index with Match or Hlookup.... If we have duplicate value in a cell we all know, Vlookup will pick up against the first item would be matching in loopkup array....So here is solution for you all...

e.g.

in Column A we have field called company....

Column A                             Column B            Column C

Company_Name                         Value        
Monster                              25000                              
Naukri                               30000  
WNS                                  80000  
American Express                     40000  
Bank of America                      50000  
Alcatel Lucent                       35000  
Google                               75000  
Microsoft                            60000  
Monster                              35000  
Bank of America                      15000 

Now if you lookup the above dataset, you would see the duplicity is in Company Name at Row No# 10 & 11. So if you put the vlookup, the data will be picking up which comes first..But if you use the below formula, you can make your lookup value Unique and can pick any data easily without having any dispute or facing any problem

Put the formula in C2.........A2&"_"&COUNTIF(A2:$A$2,A2)..........Result will be Monster_1 for first line item and for row no 10 & 11.....Monster_2, Bank of America_2 respectively....Here you go now you have the unique value so now you can pick any data easily now..

Cheers!!! Anil Dhawan

Import existing source code to GitHub

I had a bit of trouble with merging when trying to do Pete's steps. These are the steps I ended up with.

  1. Use your OS to delete the .git folder inside of the project folder that you want to commit. This will give you a clean slate to work with. This is also a good time to make a .gitignore file inside the project folder. This can be a copy of the .gitignore created when you created the repository on github.com. Doing this copy will avoid deleting it when you update the github.com repository.

  2. Open Git Bash and navigate to the folder you just deleted the .git folder from.

  3. Run git init. This sets up a local repository in the folder you're in.

  4. Run git remote add [alias] https://github.com/[gitUserName]/[RepoName].git. [alias] can be anything you want. The [alias] is meant to tie to the local repository, so the machine name works well for an [alias]. The URL can be found on github.com, along the top ensure that the HTTP button out of HTTP|SSH|Git Read-Only is clicked. The git:// URL didn't work for me.

  5. Run git pull [alias] master. This will update your local repository and avoid some merging conflicts.

  6. Run git add .

  7. Run git commit -m 'first code commit'

  8. Run git push [alias] master

Change table header color using bootstrap

Here is another way to separate your table header and table body:

thead th {
    background-color: #006DCC;
    color: white;
}

tbody td {
    background-color: #EEEEEE;
}

Have a look at this example for separation of head and body of table. JsFiddleLink

How do I apply a CSS class to Html.ActionLink in ASP.NET MVC?

@ewomack has a great answer for C#, unless you don't need extra object values. In my case, I ended up using something similar to:

@Html.ActionLink("Delete", "DeleteList", "List", new object { },
new { @class = "delete"})

Parse an HTML string with JS

1 Way

Use document.cloneNode()

Performance is:

Call to document.cloneNode() took ~0.22499999977299012 milliseconds.

and maybe will be more.

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_x000D_
var t0, t1, html;

t0 = performance.now();
   html = document.cloneNode(true);
t1 = performance.now();

console.log("Call to doSomething took " + (t1 - t0) + " milliseconds.")

html.documentElement.innerHTML = '<!DOCTYPE html><html><head><title>Test</title></head><body><div id="test1">test1</div></body></html>';

console.log(html.getElementById("test1"));
_x000D_
_x000D_
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2 Way

Use document.implementation.createHTMLDocument()

Performance is:

Call to document.implementation.createHTMLDocument() took ~0.14000000010128133 milliseconds.

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_x000D_
var t0, t1, html;

t0 = performance.now();
html = document.implementation.createHTMLDocument("test");
t1 = performance.now();

console.log("Call to doSomething took " + (t1 - t0) + " milliseconds.")

html.documentElement.innerHTML = '<!DOCTYPE html><html><head><title>Test</title></head><body><div id="test1">test1</div></body></html>';

console.log(html.getElementById("test1"));
_x000D_
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3 Way

Use document.implementation.createDocument()

Performance is:

Call to document.implementation.createHTMLDocument() took ~0.14000000010128133 milliseconds.

var t0 = performance.now();
  html = document.implementation.createDocument('', 'html', 
             document.implementation.createDocumentType('html', '', '')
         );
var t1 = performance.now();

console.log("Call to doSomething took " + (t1 - t0) + " milliseconds.")

html.documentElement.innerHTML = '<html><head><title>Test</title></head><body><div id="test1">test</div></body></html>';

console.log(html.getElementById("test1"));

4 Way

Use new Document()

Performance is:

Call to document.implementation.createHTMLDocument() took ~0.13499999840860255 milliseconds.

  • Note

ParentNode.append is experimental technology in 2020 year.

var t0, t1, html;

t0 = performance.now();
//---------------
html = new Document();

html.append(
  html.implementation.createDocumentType('html', '', '')
);
    
html.append(
  html.createElement('html')
);
//---------------
t1 = performance.now();

console.log("Call to doSomething took " + (t1 - t0) + " milliseconds.")

html.documentElement.innerHTML = '<html><head><title>Test</title></head><body><div id="test1">test1</div></body></html>';

console.log(html.getElementById("test1"));

Error in file(file, "rt") : cannot open the connection

Error in file(file, "rt")

Created a .r file and saved it in Desktop together with a sample_10000.csv file.

Once trying to read it

heisenberg <- read.csv(file="sample_100000.csv")

was getting the same error as you

heisenberg <- read.csv(file="sample_10000") Error in file(file, "rt") : cannot open the connection In addition: Warning message: In file(file, "rt") : cannot open file 'sample_10000': No such file or directory


I knew at least two ways to fix this, one using the absolute path and the other changing the working directory.

Absolute path

I fixed it adding the absolute path to the file, more precisely

heisenberg <- read.csv(file="C:/Users/tiago/Desktop/sample_100000.csv")

Working directory

This error shows up because RStudio has a specific working directory defined which isn't necessarily the place the .r file is at.

So, to fix using this approach I've gone to Session > Set Working Directory > Chose Directory (CTRL + Shift + H) and selected Desktop, where the .csv file was at. That way running the following command also worked

heisenberg <- read.csv(file="sample_100000.csv")

Using comma as list separator with AngularJS

I think it's better to use ng-if. ng-show creates an element in the dom and sets it's display:none. The more dom elements you have the more resource hungry your app becomes, and on devices with lower resources the less dom elements the better.

TBH <span ng-if="!$last">, </span> seems like a great way to do it. It's simple.

Get the value of input text when enter key pressed

Something like this (not tested, but should work)

Pass this as parameter in Html:

<input type="text" placeholder="some text" class="search" onkeydown="search(this)"/>

And alert the value of the parameter passed into the search function:

function search(e){
  alert(e.value);
}

get next sequence value from database using hibernate

You can use Hibernate Dialect API for Database independence as follow

class SequenceValueGetter {
    private SessionFactory sessionFactory;

    // For Hibernate 3
    public Long getId(final String sequenceName) {
        final List<Long> ids = new ArrayList<Long>(1);

        sessionFactory.getCurrentSession().doWork(new Work() {
            public void execute(Connection connection) throws SQLException {
                DialectResolver dialectResolver = new StandardDialectResolver();
                Dialect dialect =  dialectResolver.resolveDialect(connection.getMetaData());
                PreparedStatement preparedStatement = null;
                ResultSet resultSet = null;
                try {
                    preparedStatement = connection.prepareStatement( dialect.getSequenceNextValString(sequenceName));
                    resultSet = preparedStatement.executeQuery();
                    resultSet.next();
                    ids.add(resultSet.getLong(1));
                }catch (SQLException e) {
                    throw e;
                } finally {
                    if(preparedStatement != null) {
                        preparedStatement.close();
                    }
                    if(resultSet != null) {
                        resultSet.close();
                    }
                }
            }
        });
        return ids.get(0);
    }

    // For Hibernate 4
    public Long getID(final String sequenceName) {
        ReturningWork<Long> maxReturningWork = new ReturningWork<Long>() {
            @Override
            public Long execute(Connection connection) throws SQLException {
                DialectResolver dialectResolver = new StandardDialectResolver();
                Dialect dialect =  dialectResolver.resolveDialect(connection.getMetaData());
                PreparedStatement preparedStatement = null;
                ResultSet resultSet = null;
                try {
                    preparedStatement = connection.prepareStatement( dialect.getSequenceNextValString(sequenceName));
                    resultSet = preparedStatement.executeQuery();
                    resultSet.next();
                    return resultSet.getLong(1);
                }catch (SQLException e) {
                    throw e;
                } finally {
                    if(preparedStatement != null) {
                        preparedStatement.close();
                    }
                    if(resultSet != null) {
                        resultSet.close();
                    }
                }

            }
        };
        Long maxRecord = sessionFactory.getCurrentSession().doReturningWork(maxReturningWork);
        return maxRecord;
    }

}

Best Java obfuscator?

As said elsewhere on here, proguard is good, but what might not be known is that there is also a third-party maven plugin for it here http://pyx4me.com/pyx4me-maven-plugins/proguard-maven-plugin/...I've used them both together and they're very good.

Qt - reading from a text file

You have to replace string line

QString line = in.readLine();

into while:

QFile file("/home/hamad/lesson11.txt");
if(!file.open(QIODevice::ReadOnly)) {
    QMessageBox::information(0, "error", file.errorString());
}

QTextStream in(&file);

while(!in.atEnd()) {
    QString line = in.readLine();    
    QStringList fields = line.split(",");    
    model->appendRow(fields);    
}

file.close();

Unable to find velocity template resources

Just a simple velocity standalone app based on maven structure. Here is the code snippet written in Scala to render the template helloworld.vm in

${basedir}/src/main/resources folder:

SQLAlchemy insert or update example

I try lots of ways and finally try this:

def db_persist(func):
    def persist(*args, **kwargs):
        func(*args, **kwargs)
        try:
            session.commit()
            logger.info("success calling db func: " + func.__name__)
            return True
        except SQLAlchemyError as e:
            logger.error(e.args)
            session.rollback()
            return False

    return persist

and :

@db_persist
def insert_or_update(table_object):
    return session.merge(table_object)

What is the best way to trigger onchange event in react js

Expanding on the answer from Grin/Dan Abramov, this works across multiple input types. Tested in React >= 15.5

const inputTypes = [
    window.HTMLInputElement,
    window.HTMLSelectElement,
    window.HTMLTextAreaElement,
];

export const triggerInputChange = (node, value = '') => {

    // only process the change on elements we know have a value setter in their constructor
    if ( inputTypes.indexOf(node.__proto__.constructor) >-1 ) {

        const setValue = Object.getOwnPropertyDescriptor(node.__proto__, 'value').set;
        const event = new Event('input', { bubbles: true });

        setValue.call(node, value);
        node.dispatchEvent(event);

    }

};

How to set the JSTL variable value in javascript?

<script ...
  function(){
   var someJsVar = "<c:out value='${someJstLVarFromBackend}'/>";

  }
</script>

This works even if you dont have a hidden/non-hidden input field set somewhere in the jsp.

How to use log levels in java

Generally, you don't need all those levels, SEVERE, WARNING, INFO, FINE might be enough. We're using Log4J (not java.util.logging directly) and the following levels (which might differ in name from other logging frameworks):

  • ERROR: Any error/exception that is or might be critical. Our Logger automatically sends an email for each such message on our servers (usage: logger.error("message"); )

  • WARN: Any message that might warn us of potential problems, e.g. when a user tried to log in with wrong credentials - which might indicate an attack if that happens often or in short periods of time (usage: logger.warn("message"); )

  • INFO: Anything that we want to know when looking at the log files, e.g. when a scheduled job started/ended (usage: logger.info("message"); )

  • DEBUG: As the name says, debug messages that we only rarely turn on. (usage: logger.debug("message"); )

The beauty of this is that if you set the log level to WARN, info and debug messages have next to no performance impact. If you need to get additional information from a production system you just can lower the level to INFO or DEBUG for a short period of time (since you'd get much more log entries which make your log files bigger and harder to read). Adjusting log levels etc. can normally be done at runtime (our JBoss instance checks for changes in that config every minute or so).

Getting time difference between two times in PHP

You can also use DateTime class:

$time1 = new DateTime('09:00:59');
$time2 = new DateTime('09:01:00');
$interval = $time1->diff($time2);
echo $interval->format('%s second(s)');

Result:

1 second(s)

matplotlib: plot multiple columns of pandas data frame on the bar chart

You can plot several columns at once by supplying a list of column names to the plot's y argument.

df.plot(x="X", y=["A", "B", "C"], kind="bar")

enter image description here

This will produce a graph where bars are sitting next to each other.

In order to have them overlapping, you would need to call plot several times, and supplying the axes to plot to as an argument ax to the plot.

import pandas as pd
import matplotlib.pyplot as plt
import numpy as np

y = np.random.rand(10,4)
y[:,0]= np.arange(10)
df = pd.DataFrame(y, columns=["X", "A", "B", "C"])

ax = df.plot(x="X", y="A", kind="bar")
df.plot(x="X", y="B", kind="bar", ax=ax, color="C2")
df.plot(x="X", y="C", kind="bar", ax=ax, color="C3")

plt.show()

enter image description here

How big can a MySQL database get before performance starts to degrade

No it doesnt really matter. The MySQL speed is about 7 Million rows per second. So you can scale it quite a bit

Writing sqlplus output to a file

Make sure you have the access to the directory you are trying to spool. I tried to spool to root and it did not created the file (e.g c:\test.txt). You can check where you are spooling by issuing spool command.

Remove file extension from a file name string

The Path.GetFileNameWithoutExtension method gives you the filename you pass as an argument without the extension, as should be obvious from the name.

Is there an XSL "contains" directive?

<xsl:if test="not contains(hhref,'1234')">

How to copy a row and insert in same table with a autoincrement field in MySQL?

For a quick, clean solution that doesn't require you to name columns, you can use a prepared statement as described here: https://stackoverflow.com/a/23964285/292677

If you need a complex solution so you can do this often, you can use this procedure:

DELIMITER $$

CREATE PROCEDURE `duplicateRows`(_schemaName text, _tableName text, _whereClause text, _omitColumns text)
SQL SECURITY INVOKER
BEGIN
  SELECT IF(TRIM(_omitColumns) <> '', CONCAT('id', ',', TRIM(_omitColumns)), 'id') INTO @omitColumns;

  SELECT GROUP_CONCAT(COLUMN_NAME) FROM information_schema.columns 
  WHERE table_schema = _schemaName AND table_name = _tableName AND FIND_IN_SET(COLUMN_NAME,@omitColumns) = 0 ORDER BY ORDINAL_POSITION INTO @columns;

  SET @sql = CONCAT('INSERT INTO ', _tableName, '(', @columns, ')',
  'SELECT ', @columns, 
  ' FROM ', _schemaName, '.', _tableName, ' ',  _whereClause);

  PREPARE stmt1 FROM @sql;
  EXECUTE stmt1;
END

You can run it with:

CALL duplicateRows('database', 'table', 'WHERE condition = optional', 'omit_columns_optional');

Examples

duplicateRows('acl', 'users', 'WHERE id = 200'); -- will duplicate the row for the user with id 200
duplicateRows('acl', 'users', 'WHERE id = 200', 'created_ts'); -- same as above but will not copy the created_ts column value    
duplicateRows('acl', 'users', 'WHERE id = 200', 'created_ts,updated_ts'); -- same as above but also omits the updated_ts column
duplicateRows('acl', 'users'); -- will duplicate all records in the table

DISCLAIMER: This solution is only for someone who will be repeatedly duplicating rows in many tables, often. It could be dangerous in the hands of a rogue user.

std::string to char*

For completeness' sake, don't forget std::string::copy().

std::string str = "string";
const size_t MAX = 80;
char chrs[MAX];

str.copy(chrs, MAX);

std::string::copy() doesn't NUL terminate. If you need to ensure a NUL terminator for use in C string functions:

std::string str = "string";
const size_t MAX = 80;
char chrs[MAX];

memset(chrs, '\0', MAX);
str.copy(chrs, MAX-1);

Which UUID version to use?

If you want a random number, use a random number library. If you want a unique identifier with effectively 0.00...many more 0s here...001% chance of collision, you should use UUIDv1. See Nick's post for UUIDv3 and v5.

UUIDv1 is NOT secure. It isn't meant to be. It is meant to be UNIQUE, not un-guessable. UUIDv1 uses the current timestamp, plus a machine identifier, plus some random-ish stuff to make a number that will never be generated by that algorithm again. This is appropriate for a transaction ID (even if everyone is doing millions of transactions/s).

To be honest, I don't understand why UUIDv4 exists... from reading RFC4122, it looks like that version does NOT eliminate possibility of collisions. It is just a random number generator. If that is true, than you have a very GOOD chance of two machines in the world eventually creating the same "UUID"v4 (quotes because there isn't a mechanism for guaranteeing U.niversal U.niqueness). In that situation, I don't think that algorithm belongs in a RFC describing methods for generating unique values. It would belong in a RFC about generating randomness. For a set of random numbers:

chance_of_collision = 1 - (set_size! / (set_size - tries)!) / (set_size ^ tries)

What does the ^ (XOR) operator do?

The (^) XOR operator generates 1 when it is applied on two different bits (0 and 1). It generates 0 when it is applied on two same bits (0 and 0 or 1 and 1).

How to write lists inside a markdown table?

Not that I know of, because all markdown references I am aware of, like this one, mention:

Cell content must be on one line only

You can try it with that Markdown Tables Generator (whose example looks like the one you mention in your question, so you may be aware of it already).

Pandoc

If you are using Pandoc’s markdown (which extends John Gruber’s markdown syntax on which the GitHub Flavored Markdown is based) you can use either grid_tables:

+---------------+---------------+--------------------+
| Fruit         | Price         | Advantages         |
+===============+===============+====================+
| Bananas       | $1.34         | - built-in wrapper |
|               |               | - bright color     |
+---------------+---------------+--------------------+
| Oranges       | $2.10         | - cures scurvy     |
|               |               | - tasty            |
+---------------+---------------+--------------------+

or multiline_tables.

-------------------------------------------------------------
 Centered   Default           Right Left
  Header    Aligned         Aligned Aligned
----------- ------- --------------- -------------------------
   First    row                12.0 Example of a row that
                                    spans multiple lines.

  Second    row                 5.0 Here's another one. Note
                                    the blank line between
                                    rows.
-------------------------------------------------------------

How to trigger a phone call when clicking a link in a web page on mobile phone

The proper URL scheme is tel:[number] so you would do

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<a href="tel:5551234567"><img src="callme.jpg" /></a>
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Convert a Pandas DataFrame to a dictionary

Should a dictionary like:

{'red': '0.500', 'yellow': '0.250, 'blue': '0.125'}

be required out of a dataframe like:

        a      b
0     red  0.500
1  yellow  0.250
2    blue  0.125

simplest way would be to do:

dict(df.values)

working snippet below:

import pandas as pd
df = pd.DataFrame({'a': ['red', 'yellow', 'blue'], 'b': [0.5, 0.25, 0.125]})
dict(df.values)

How to get just numeric part of CSS property with jQuery?

This will clean up all non-digits, non-dots, and not-minus-sign from the string:

$(this).css('marginBottom').replace(/[^-\d\.]/g, '');

UPDATED for negative values

sqlite copy data from one table to another

If you have data already present in both the tables and you want to update a table column values based on some condition then use this

UPDATE Table1 set Name=(select t2.Name from Table2 t2 where t2.id=Table1.id)

How to config routeProvider and locationProvider in angularJS?

Try this

If you are deploying your app into the root context (e.g. https://myapp.com/), set the base URL to /:

<head>
  <base href="/">
  ...
</head>

Angular Documentation

IE11 meta element Breaks SVG

Check if the Browser is IE -

  $ua = htmlentities($_SERVER['HTTP_USER_AGENT'], ENT_QUOTES, 'UTF-8');
  if (preg_match('~MSIE|Internet Explorer~i', $ua) || (strpos($ua, 'Trident/7.0') !== false && strpos($ua, 'rv:11.0') !== false)) {
    // do stuff for IE Here
  }

Limit Decimal Places in Android EditText

I improved on the solution that uses a regex by Pinhassi so it also handles the edge cases correctly. Before checking if the input is correct, first the final string is constructed as described by the android docs.

public class DecimalDigitsInputFilter implements InputFilter {

    private Pattern mPattern;

    private static final Pattern mFormatPattern = Pattern.compile("\\d+\\.\\d+");

    public DecimalDigitsInputFilter(int digitsBeforeDecimal, int digitsAfterDecimal) {
        mPattern = Pattern.compile(
            "^\\d{0," + digitsBeforeDecimal + "}([\\.,](\\d{0," + digitsAfterDecimal +
                "})?)?$");
    }

    @Override
    public CharSequence filter(CharSequence source, int start, int end, Spanned dest, 
                               int dstart, int dend) {

        String newString =
            dest.toString().substring(0, dstart) + source.toString().substring(start, end) 
            + dest.toString().substring(dend, dest.toString().length());

        Matcher matcher = mPattern.matcher(newString);
        if (!matcher.matches()) {
            return "";
        }
        return null;
    }
}

Usage:

editText.setFilters(new InputFilter[] {new DecimalDigitsInputFilter(5,2)});

How can I make a Python script standalone executable to run without ANY dependency?

Using PyInstaller, I found a better method using shortcut to the .exe rather than making --onefile. Anyway, there are probably some data files around and if you're running a site-based app then your program depends on HTML, JavaScript, and CSS files too. There isn't any point in moving all these files somewhere... Instead what if we move the working path up?

Make a shortcut to the EXE file, move it at top and set the target and start-in paths as specified, to have relative paths going to dist\folder:

Target: %windir%\system32\cmd.exe /c start dist\web_wrapper\web_wrapper.exe
Start in: "%windir%\system32\cmd.exe /c start dist\web_wrapper\"

We can rename the shortcut to anything, so renaming to "GTFS-Manager". Now when I double-click the shortcut, it's as if I python-ran the file! I found this approach better than the --onefile one as:

  1. In onefile's case, there's a problem with a .dll missing for the Windows 7 OS which needs some prior installation, etc. Yawn. With the usual build with multiple files, no such issues.
  2. All the files that my Python script uses (it's deploying a tornado web server and needs a whole freakin' website worth of files to be there!) don't need to be moved anywhere: I simply create the shortcut at top.
  3. I can actually use this exact same folder on Ubuntu (run python3 myfile.py) and Windows (double-click the shortcut).
  4. I don't need to bother with the overly complicated hacking of .spec file to include data files, etc.

Oh, remember to delete off the build folder after building. It will save on size.

using nth-child in tables tr td

table tr td:nth-child(2) {
    background: #ccc;
}

Working example: http://jsfiddle.net/gqr3J/

How to display raw JSON data on a HTML page

JSON in any HTML tag except <script> tag would be a mere text. Thus it's like you add a story to your HTML page.

However, about formatting, that's another matter. I guess you should change the title of your question.

Take a look at this question. Also see this page.

"Comparison method violates its general contract!"

Just because this is what I got when I Googled this error, my problem was that I had

if (value < other.value)
  return -1;
else if (value >= other.value)
  return 1;
else
  return 0;

the value >= other.value should (obviously) actually be value > other.value so that you can actually return 0 with equal objects.

Task not serializable: java.io.NotSerializableException when calling function outside closure only on classes not objects

I had a similar experience.

The error was triggered when I initialize a variable on the driver (master), but then tried to use it on one of the workers. When that happens, Spark Streaming will try to serialize the object to send it over to the worker, and fail if the object is not serializable.

I solved the error by making the variable static.

Previous non-working code

  private final PhoneNumberUtil phoneUtil = PhoneNumberUtil.getInstance();

Working code

  private static final PhoneNumberUtil phoneUtil = PhoneNumberUtil.getInstance();

Credits:

  1. https://docs.microsoft.com/en-us/answers/questions/35812/sparkexception-job-aborted-due-to-stage-failure-ta.html ( The answer of pradeepcheekatla-msft)
  2. https://databricks.gitbooks.io/databricks-spark-knowledge-base/content/troubleshooting/javaionotserializableexception.html

How to display Woocommerce Category image?

To prevent full size category images slowing page down, you can use smaller images with wp_get_attachment_image_src():

<?php 

$thumbnail_id = get_woocommerce_term_meta( $term->term_id, 'thumbnail_id', true );

// get the medium-sized image url
$image = wp_get_attachment_image_src( $thumbnail_id, 'medium' );

// Output in img tag
echo '<img src="' . $image[0] . '" alt="" />'; 

// Or as a background for a div
echo '<div class="image" style="background-image: url("' . $image[0] .'")"></div>';

?>

EDIT: Fixed variable name and missing quote

What is the iOS 5.0 user agent string?

This site seems to keep a complete list that's still maintained

iPhone, iPod Touch, and iPad from iOS 2.0 - 5.1.1 (to date).

You do need to assemble the full user-agent string out of the information listed in the page's columns.

When should we use Observer and Observable?

Since Java9, both interfaces are deprecated, meaning you should not use them anymore. See Observer is deprecated in Java 9. What should we use instead of it?

However, you might still get interview questions about them...

How to get data from Magento System Configuration

you should you use following code

$configValue = Mage::getStoreConfig(
                   'sectionName/groupName/fieldName',
                   Mage::app()->getStore()
               ); 

Mage::app()->getStore() this will add store code in fetch values so that you can get correct configuration values for current store this will avoid incorrect store's values because magento is also use for multiple store/views so must add store code to fetch anything in magento.

if we have more then one store or multiple views configured then this will insure that we are getting values for current store

JRE 1.7 - java version - returns: java/lang/NoClassDefFoundError: java/lang/Object

Go to control panel, uninstall the java related stuff(close eclipse if opened), then re-install java and open eclipse, clean projects.

How to remove all options from a dropdown using jQuery / JavaScript

You can either use .remove() on option elements:

.remove() : Remove the set of matched elements from the DOM.

 $('#models option').remove(); or $('#models').remove('option');

or use .empty() on select:

.empty() : Remove all child nodes of the set of matched elements from the DOM.

 $('#models').empty();

however to repopulate deleted options, you need to store the option while deleting.

You can also achieve the same using show/hide:

$("#models option").hide();

and later on to show them:

$("#models option").show();

ValueError: unconverted data remains: 02:05

Well it was very simple. I was missing the format of the date in the json file, so I should write :

st = datetime.strptime(st, '%A %d %B %H %M')

because in the json file the date was like :

"start": "Friday 06 December 02:05",

Is it better in C++ to pass by value or pass by constant reference?

As it has been pointed out, it depends on the type. For built-in data types, it is best to pass by value. Even some very small structures, such as a pair of ints can perform better by passing by value.

Here is an example, assume you have an integer value and you want pass it to another routine. If that value has been optimized to be stored in a register, then if you want to pass it be reference, it first must be stored in memory and then a pointer to that memory placed on the stack to perform the call. If it was being passed by value, all that is required is the register pushed onto the stack. (The details are a bit more complicated than that given different calling systems and CPUs).

If you are doing template programming, you are usually forced to always pass by const ref since you don't know the types being passed in. Passing penalties for passing something bad by value are much worse than the penalties of passing a built-in type by const ref.

How do I close an open port from the terminal on the Mac?

  1. First find out the Procees id (pid) which has occupied the required port.(e.g 5434)

    ps aux | grep 5434

2.kill that process

   kill -9 <pid>

npm ERR! network getaddrinfo ENOTFOUND

Take a look at your HTTP_PROXY and HTTPS_PROXY environment variables.

I thought mine were set correctly, as http://username:password@proxyhost:proxyport, but it turned out that they were actually causing the problem! After deleting those variables, and restarting the commant prompt, the npm commands worked again.

Returning pointer from a function

Although returning a pointer to a local object is bad practice, it didn't cause the kaboom here. Here's why you got a segfault:

int *fun()
{
    int *point;
    *point=12;  <<<<<<  your program crashed here.
    return point;
}

The local pointer goes out of scope, but the real issue is dereferencing a pointer that was never initialized. What is the value of point? Who knows. If the value did not map to a valid memory location, you will get a SEGFAULT. If by luck it mapped to something valid, then you just corrupted memory by overwriting that place with your assignment to 12.

Since the pointer returned was immediately used, in this case you could get away with returning a local pointer. However, it is bad practice because if that pointer was reused after another function call reused that memory in the stack, the behavior of the program would be undefined.

int *fun()
{
    int point;
    point = 12;
    return (&point);
}

or almost identically:

int *fun()
{
    int point;
    int *point_ptr;
    point_ptr = &point;
    *point_ptr = 12;
    return (point_ptr);
}

Another bad practice but safer method would be to declare the integer value as a static variable, and it would then not be on the stack and would be safe from being used by another function:

int *fun()
{
    static int point;
    int *point_ptr;
    point_ptr = &point;
    *point_ptr = 12;
    return (point_ptr);
}

or

int *fun()
{
    static int point;
    point = 12;
    return (&point);
}

As others have mentioned, the "right" way to do this would be to allocate memory on the heap, via malloc.

How is a CSS "display: table-column" supposed to work?

The "table-column" display type means it acts like the <col> tag in HTML - i.e. an invisible element whose width* governs the width of the corresponding physical column of the enclosing table.

See the W3C standard for more information about the CSS table model.

* And a few other properties like borders, backgrounds.

How Can I Resolve:"can not open 'git-upload-pack' " error in eclipse?

I had the same problem when my network config was incorrect and DNS was not resolving. In other words the issue could arise when there is no Network Access.

How to reference a .css file on a razor view?

layout works the same as an master page. any css reference that layout has, any child pages will have.

Scott Gu has an excellent explanation here

Angular ui-grid dynamically calculate height of the grid

following @tony's approach, changed the getTableHeight() function to

<div id="grid1" ui-grid="$ctrl.gridOptions" class="grid" ui-grid-auto-resize style="{{$ctrl.getTableHeight()}}"></div>

getTableHeight() {
    var offsetValue = 365;
    return "height: " + parseInt(window.innerHeight - offsetValue ) + "px!important";
}

the grid would have a dynamic height with regards to window height as well.

How to use moment.js library in angular 2 typescript app?

Not sure if this is still an issue for people, however... Using SystemJS and MomentJS as library, this solved it for me

/*
 * Import Custom Components
 */
import * as moment from 'moment/moment'; // please use path to moment.js file, extension is set in system.config

// under systemjs, moment is actually exported as the default export, so we account for that
const momentConstructor: (value?: any) => moment.Moment = (<any>moment).default || moment;

Works fine from there for me.

String.Format alternative in C++

In addition to options suggested by others I can recommend the fmt library which implements string formatting similar to str.format in Python and String.Format in C#. Here's an example:

std::string a = "test";
std::string b = "text.txt";
std::string c = "text1.txt";
std::string result = fmt::format("{0} {1} > {2}", a, b, c);

Disclaimer: I'm the author of this library.

How to change permissions for a folder and its subfolders/files in one step?

To set to all subfolders (recursively) use -R

chmod 755 /folder -R

And use umask to set the default to new folders/files cd /folder umask 755

Print in one line dynamically

Another answer that I'm using on 2.7 where I'm just printing out a "." every time a loop runs (to indicate to the user that things are still running) is this:

print "\b.",

It prints the "." characters without spaces between each. It looks a little better and works pretty well. The \b is a backspace character for those wondering.

jQuery get input value after keypress

please use this code for input text

$('#search').on("input",function (e) {});

if you use .on("change",function (e) {}); then you need to blur input

if you use .on("keyup",function (e) {}); then you get value before the last character you typed

How to use a calculated column to calculate another column in the same view

In Sql Server

You can do this using cross apply

Select
  ColumnA,
  ColumnB,
  c.calccolumn1 As calccolumn1,
  c.calccolumn1 / ColumnC As calccolumn2
from t42
cross apply (select (ColumnA + ColumnB) as calccolumn1) as c

How does a Java HashMap handle different objects with the same hash code?

You're mistaken on point three. Two entries can have the same hash code but not be equal. Take a look at the implementation of HashMap.get from the OpenJdk. You can see that it checks that the hashes are equal and the keys are equal. Were point three true, then it would be unnecessary to check that the keys are equal. The hash code is compared before the key because the former is a more efficient comparison.

If you're interested in learning a little more about this, take a look at the Wikipedia article on Open Addressing collision resolution, which I believe is the mechanism that the OpenJdk implementation uses. That mechanism is subtly different than the "bucket" approach one of the other answers mentions.

Add Expires headers

In ASP.NET there is similar object, you can use Caching Portions in WebFormsUserControls in order to cache objects of a page for a period of time and save server resources. This is also known as fragment caching.
If you include this code to top of your user control, a version of the control stored in the output cache for 150 seconds. You can create your own control that would contain expire header for a specific resource you want.

<%@ OutputCache Duration="150" VaryByParam="None" %>

This article explain it completely: Caching Portions of an ASP.NET Page

500 internal server error, how to debug

Try writing all the errors to a file.

error_reporting(-1); // reports all errors
ini_set("display_errors", "1"); // shows all errors
ini_set("log_errors", 1);
ini_set("error_log", "/tmp/php-error.log");

Something like that.

Correct use for angular-translate in controllers

Recommended: don't translate in the controller, translate in your view

I'd recommend to keep your controller free from translation logic and translate your strings directly inside your view like this:

<h1>{{ 'TITLE.HELLO_WORLD' | translate }}</h1>

Using the provided service

Angular Translate provides the $translate service which you can use in your Controllers.

An example usage of the $translate service can be:

.controller('TranslateMe', ['$scope', '$translate', function ($scope, $translate) {
    $translate('PAGE.TITLE')
        .then(function (translatedValue) {
            $scope.pageTitle = translatedValue;
        });
});

The translate service also has a method for directly translating strings without the need to handle a promise, using $translate.instant():

.controller('TranslateMe', ['$scope', '$translate', function ($scope, $translate) {
    $scope.pageTitle = $translate.instant('TITLE.DASHBOARD'); // Assuming TITLE.DASHBOARD is defined
});

The downside with using $translate.instant() could be that the language file isn't loaded yet if you are loading it async.

Using the provided filter

This is my preferred way since I don't have to handle promises this way. The output of the filter can be directly set to a scope variable.

.controller('TranslateMe', ['$scope', '$filter', function ($scope, $filter) {
    var $translate = $filter('translate');

    $scope.pageTitle = $translate('TITLE.DASHBOARD'); // Assuming TITLE.DASHBOARD is defined
});

Using the provided directive

Since @PascalPrecht is the creator of this awesome library, I'd recommend going with his advise (see his answer below) and use the provided directive which seems to handle translations very intelligent.

The directive takes care of asynchronous execution and is also clever enough to unwatch translation ids on the scope if the translation has no dynamic values.

Oracle PL Sql Developer cannot find my tnsnames.ora file

I had the same problema, but as described in the manual.pdf, you have to:

You are using an Oracle Instant Client but have not set all required environment variables:

  • PATH: Needs to include the Instant Client directory where oci.dll is located
  • TNS_ADMIN: Needs to point to the directory where tnsnames.ora is located.
  • NLS_LANG: Defines the language, territory, and character set for the client.

Regards

cURL error 60: SSL certificate: unable to get local issuer certificate

Attention Wamp/Wordpress/windows users. I had this issue for hours and not even the correct answer was doing it for me, because i was editing the wrong php.ini file because the question was answered to XAMPP and not for WAMP users, even though the question was for WAMP.

here's what i did

Download the certificate bundle.

Put it inside of C:\wamp64\bin\php\your php version\extras\ssl

Make sure the file mod_ssl.so is inside of C:\wamp64\bin\apache\apache(version)\modules

Enable mod_ssl in httpd.conf inside of Apache directory C:\wamp64\bin\apache\apache2.4.27\conf

Enable php_openssl.dll in php.ini. Be aware my problem was that I had two php.ini files and I need to do this in both of them. First one can be located inside of your WAMP taskbar icon here.

enter image description here

and the other one is located in C:\wamp64\bin\php\php(Version)

find the location for both of the php.ini files and find the line curl.cainfo = and give it a path like this

curl.cainfo = "C:\wamp64\bin\php\php(Version)\extras\ssl\cacert.pem"

Now save the files and restart your server and you should be good to go

Convert Map to JSON using Jackson

Using jackson, you can do it as follows:

    ObjectMapper mapper = new ObjectMapper();
    String clientFilterJson = "";
    try {
        clientFilterJson = mapper.writeValueAsString(filterSaveModel);
    } catch (IOException e) {
        e.printStackTrace();
    }

Android device is not connected to USB for debugging (Android studio)

After you put your phone on developer mode, restart it. That worked for me, maybe it will work for you also. After restarting it, the phone was recognized, drivers were automatically installed. Note - I'm running on Windows 7.

android.content.res.Resources$NotFoundException: String resource ID Fatal Exception in Main

You are trying to set int value to TextView so you are getting this issue. To solve this try below one option

option 1:

tv.setText(no+"");

Option2:

tv.setText(String.valueOf(no));

How can I convert a zero-terminated byte array to string?

Though not extremely performant, the only readable solution is:

  // Split by separator and pick the first one.
  // This has all the characters till null, excluding null itself.
  retByteArray := bytes.Split(byteArray[:], []byte{0}) [0]

  // OR

  // If you want a true C-like string, including the null character
  retByteArray := bytes.SplitAfter(byteArray[:], []byte{0}) [0]

A full example to have a C-style byte array:

package main

import (
    "bytes"
    "fmt"
)

func main() {
    var byteArray = [6]byte{97,98,0,100,0,99}

    cStyleString := bytes.SplitAfter(byteArray[:], []byte{0}) [0]
    fmt.Println(cStyleString)
}

A full example to have a Go style string excluding the nulls:

package main

import (
    "bytes"
    "fmt"
)

func main() {
    var byteArray = [6]byte{97, 98, 0, 100, 0, 99}

    goStyleString := string(bytes.Split(byteArray[:], []byte{0}) [0])
    fmt.Println(goStyleString)
}

This allocates a slice of slice of bytes. So keep an eye on performance if it is used heavily or repeatedly.

No module named serial

You must have the pyserial library installed. You do not need the serial library.Therefore, if the serial library is pre-installed, uninstall it. Install the pyserial libray. There are many methods of installing:-

  1. pip install pyserial
  2. Download zip from pyserial and save extracted library in Lib>>site-packages folder of Python.
  3. Download wheel and install wheel using command: pip install <wheelname>

Link: https://github.com/pyserial/pyserial/releases

After installing Pyserial, Navigate to the location where pyserial is installed. You will see a "setup.py" file. Open Power Shell or CMD in the same directory and run command "python setup.py install". Now you can use all functionalities of pyserial library without any error.

python filter list of dictionaries based on key value

You can try a list comp

>>> exampleSet = [{'type':'type1'},{'type':'type2'},{'type':'type2'}, {'type':'type3'}]
>>> keyValList = ['type2','type3']
>>> expectedResult = [d for d in exampleSet if d['type'] in keyValList]
>>> expectedResult
[{'type': 'type2'}, {'type': 'type2'}, {'type': 'type3'}]

Another way is by using filter

>>> list(filter(lambda d: d['type'] in keyValList, exampleSet))
[{'type': 'type2'}, {'type': 'type2'}, {'type': 'type3'}]

Write bytes to file

If I understand you correctly, this should do the trick. You'll need add using System.IO at the top of your file if you don't already have it.

public bool ByteArrayToFile(string fileName, byte[] byteArray)
{
    try
    {
        using (var fs = new FileStream(fileName, FileMode.Create, FileAccess.Write))
        {
            fs.Write(byteArray, 0, byteArray.Length);
            return true;
        }
    }
    catch (Exception ex)
    {
        Console.WriteLine("Exception caught in process: {0}", ex);
        return false;
    }
}

Create a custom View by inflating a layout?

Yes you can do this. RelativeLayout, LinearLayout, etc are Views so a custom layout is a custom view. Just something to consider because if you wanted to create a custom layout you could.

What you want to do is create a Compound Control. You'll create a subclass of RelativeLayout, add all our your components in code (TextView, etc), and in your constructor you can read the attributes passed in from the XML. You can then pass that attribute to your title TextView.

http://developer.android.com/guide/topics/ui/custom-components.html

Easy way to dismiss keyboard?

You can send a nil targeted action to the application, it'll resign first responder at any time without having to worry about which view currently has first responder status.

Objective-C:

[[UIApplication sharedApplication] sendAction:@selector(resignFirstResponder) to:nil from:nil forEvent:nil];

Swift 3.0:

UIApplication.shared.sendAction(#selector(resignFirstResponder), to: nil, from: nil, for: nil)

Nil targeted actions are common on Mac OS X for menu commands, and here's a use for them on iOS.

how does int main() and void main() work

If you really want to understand ANSI C 89, I need to correct you in one thing; In ANSI C 89 the difference between the following functions:

int main()
int main(void)
int main(int argc, char* argv[])

is:

int main()

  • a function that expects unknown number of arguments of unknown types. Returns an integer representing the application software status.

int main(void)

  • a function that expects no arguments. Returns an integer representing the application software status.

int main(int argc, char * argv[])

  • a function that expects argc number of arguments and argv[] arguments. Returns an integer representing the application software status.

About when using each of the functions

int main(void)

  • you need to use this function when your program needs no initial parameters to run/ load (parameters received from the OS - out of the program it self).

int main(int argc, char * argv[])

  • you need to use this function when your program needs initial parameters to load (parameters received from the OS - out of the program it self).

About void main()

In ANSI C 89, when using void main and compiling the project AS -ansi -pedantic (in Ubuntu, e.g) you will receive a warning indicating that your main function is of type void and not of type int, but you will be able to run the project. Most C developers tend to use int main() on all of its variants, though void main() will also compile.

How to replace captured groups only?

A solution is to add captures for the preceding and following text:

str.replace(/(.*name="\w+)(\d+)(\w+".*)/, "$1!NEW_ID!$3")

How to repeat a string a variable number of times in C++?

As Commodore Jaeger alluded to, I don't think any of the other answers actually answer this question; the question asks how to repeat a string, not a character.

While the answer given by Commodore is correct, it is quite inefficient. Here is a faster implementation, the idea is to minimise copying operations and memory allocations by first exponentially growing the string:

#include <string>
#include <cstddef>

std::string repeat(std::string str, const std::size_t n)
{
    if (n == 0) {
        str.clear();
        str.shrink_to_fit();
        return str;
    } else if (n == 1 || str.empty()) {
        return str;
    }
    const auto period = str.size();
    if (period == 1) {
        str.append(n - 1, str.front());
        return str;
    }
    str.reserve(period * n);
    std::size_t m {2};
    for (; m < n; m *= 2) str += str;
    str.append(str.c_str(), (n - (m / 2)) * period);
    return str;
}

We can also define an operator* to get something closer to the Python version:

#include <utility>

std::string operator*(std::string str, std::size_t n)
{
    return repeat(std::move(str), n);
}

On my machine this is around 10x faster than the implementation given by Commodore, and about 2x faster than a naive 'append n - 1 times' solution.

Rename multiple files by replacing a particular pattern in the filenames using a shell script

An example to help you get off the ground.

for f in *.jpg; do mv "$f" "$(echo "$f" | sed s/IMG/VACATION/)"; done

In this example, I am assuming that all your image files contain the string IMG and you want to replace IMG with VACATION.

The shell automatically evaluates *.jpg to all the matching files.

The second argument of mv (the new name of the file) is the output of the sed command that replaces IMG with VACATION.

If your filenames include whitespace pay careful attention to the "$f" notation. You need the double-quotes to preserve the whitespace.

How to wait for a number of threads to complete?

One way would be to make a List of Threads, create and launch each thread, while adding it to the list. Once everything is launched, loop back through the list and call join() on each one. It doesn't matter what order the threads finish executing in, all you need to know is that by the time that second loop finishes executing, every thread will have completed.

A better approach is to use an ExecutorService and its associated methods:

List<Callable> callables = ... // assemble list of Callables here
                               // Like Runnable but can return a value
ExecutorService execSvc = Executors.newCachedThreadPool();
List<Future<?>> results = execSvc.invokeAll(callables);
// Note: You may not care about the return values, in which case don't
//       bother saving them

Using an ExecutorService (and all of the new stuff from Java 5's concurrency utilities) is incredibly flexible, and the above example barely even scratches the surface.

"Cannot send session cache limiter - headers already sent"

"Headers already sent" means that your PHP script already sent the HTTP headers, and as such it can't make modifications to them now.

Check that you don't send ANY content before calling session_start. Better yet, just make session_start the first thing you do in your PHP file (so put it at the absolute beginning, before all HTML etc).

Add click event on div tag using javascript

Recommend you to use Id, as Id is associated to only one element while class name may link to more than one element causing confusion to add event to element.

try if you really want to use class:

 document.getElementsByClassName('drill_cursor')[0].onclick = function(){alert('1');};

or you may assign function in html itself:

<div class="drill_cursor" onclick='alert("1");'>
</div>

How to redirect output of an entire shell script within the script itself?

You can make the whole script a function like this:

main_function() {
  do_things_here
}

then at the end of the script have this:

if [ -z $TERM ]; then
  # if not run via terminal, log everything into a log file
  main_function 2>&1 >> /var/log/my_uber_script.log
else
  # run via terminal, only output to screen
  main_function
fi

Alternatively, you may log everything into logfile each run and still output it to stdout by simply doing:

# log everything, but also output to stdout
main_function 2>&1 | tee -a /var/log/my_uber_script.log

Python Requests package: Handling xml response

requests does not handle parsing XML responses, no. XML responses are much more complex in nature than JSON responses, how you'd serialize XML data into Python structures is not nearly as straightforward.

Python comes with built-in XML parsers. I recommend you use the ElementTree API:

import requests
from xml.etree import ElementTree

response = requests.get(url)

tree = ElementTree.fromstring(response.content)

or, if the response is particularly large, use an incremental approach:

    response = requests.get(url, stream=True)
    # if the server sent a Gzip or Deflate compressed response, decompress
    # as we read the raw stream:
    response.raw.decode_content = True

    events = ElementTree.iterparse(response.raw)
    for event, elem in events:
        # do something with `elem`

The external lxml project builds on the same API to give you more features and power still.

Converting unix timestamp string to readable date

There are two parts:

  1. Convert the unix timestamp ("seconds since epoch") to the local time
  2. Display the local time in the desired format.

A portable way to get the local time that works even if the local time zone had a different utc offset in the past and python has no access to the tz database is to use a pytz timezone:

#!/usr/bin/env python
from datetime import datetime
import tzlocal  # $ pip install tzlocal

unix_timestamp = float("1284101485")
local_timezone = tzlocal.get_localzone() # get pytz timezone
local_time = datetime.fromtimestamp(unix_timestamp, local_timezone)

To display it, you could use any time format that is supported by your system e.g.:

print(local_time.strftime("%Y-%m-%d %H:%M:%S.%f%z (%Z)"))
print(local_time.strftime("%B %d %Y"))  # print date in your format

If you do not need a local time, to get a readable UTC time instead:

utc_time = datetime.utcfromtimestamp(unix_timestamp)
print(utc_time.strftime("%Y-%m-%d %H:%M:%S.%f+00:00 (UTC)"))

If you don't care about the timezone issues that might affect what date is returned or if python has access to the tz database on your system:

local_time = datetime.fromtimestamp(unix_timestamp)
print(local_time.strftime("%Y-%m-%d %H:%M:%S.%f"))

On Python 3, you could get a timezone-aware datetime using only stdlib (the UTC offset may be wrong if python has no access to the tz database on your system e.g., on Windows):

#!/usr/bin/env python3
from datetime import datetime, timezone

utc_time = datetime.fromtimestamp(unix_timestamp, timezone.utc)
local_time = utc_time.astimezone()
print(local_time.strftime("%Y-%m-%d %H:%M:%S.%f%z (%Z)"))

Functions from the time module are thin wrappers around the corresponding C API and therefore they may be less portable than the corresponding datetime methods otherwise you could use them too:

#!/usr/bin/env python
import time

unix_timestamp  = int("1284101485")
utc_time = time.gmtime(unix_timestamp)
local_time = time.localtime(unix_timestamp)
print(time.strftime("%Y-%m-%d %H:%M:%S", local_time)) 
print(time.strftime("%Y-%m-%d %H:%M:%S+00:00 (UTC)", utc_time))  

How to save a base64 image to user's disk using JavaScript?

This Works

function saveBase64AsFile(base64, fileName) {
    var link = document.createElement("a");
    document.body.appendChild(link);
    link.setAttribute("type", "hidden");
    link.href = "data:text/plain;base64," + base64;
    link.download = fileName;
    link.click();  
    document.body.removeChild(link);
}

Based on the answer above but with some changes

The property 'value' does not exist on value of type 'HTMLElement'

We could assert

const inputElement: HTMLInputElement = document.getElementById('greet')

Or with as-syntax

const inputElement = document.getElementById('greet') as HTMLInputElement

Giving

const inputValue = inputElement.value // now inferred to be string

Add an element to an array in Swift

In Swift 4.1 and Xcode 9.4.1

We can add objects to Array basically in Two ways

let stringOne = "One"
let strigTwo = "Two"
let stringThree = "Three"
var array:[String] = []//If your array is string type

Type 1)

//To append elements at the end
array.append(stringOne)
array.append(stringThree)

Type 2)

//To add elements at specific index
array.insert(strigTwo, at: 1)

If you want to add two arrays

var array1 = [1,2,3,4,5]
let array2 = [6,7,8,9]

let array3 = array1+array2
print(array3)
array1.append(contentsOf: array2)
print(array1)

Generating random, unique values C#

Same as @Habib's answer, but as a function:

List<int> randomList = new List<int>();
int UniqueRandomInt(int min, int max)
{
    var rand = new Random();
    int myNumber;
    do
    {
       myNumber = rand.Next(min, max);
    } while (randomList.Contains(myNumber));
    return myNumber;
}

If randomList is a class property, UniqueRandomInt will return unique integers in the context of the same instance of that class. If you want it to be unique globally, you will need to make randomList static.

Multiline TextView in Android?

Below code can work for Single line and Multi-line textview

isMultiLine = If true then Textview showing with Multi-line otherwise single line

    if (isMultiLine) {
        textView.setElegantTextHeight(true);
        textView.setInputType(InputType.TYPE_TEXT_FLAG_MULTI_LINE);
        textView.setSingleLine(false);
        
    } else {
        textView.setSingleLine(true);
        textView.setEllipsize(TextUtils.TruncateAt.END);
    }

Java 8 List<V> into Map<K, V>

Map<String, Set<String>> collect = Arrays.asList(Locale.getAvailableLocales()).stream().collect(Collectors
                .toMap(l -> l.getDisplayCountry(), l -> Collections.singleton(l.getDisplayLanguage())));

How to read a .xlsx file using the pandas Library in iPython?

I usually create a dictionary containing a DataFrame for every sheet:

xl_file = pd.ExcelFile(file_name)

dfs = {sheet_name: xl_file.parse(sheet_name) 
          for sheet_name in xl_file.sheet_names}

Update: In pandas version 0.21.0+ you will get this behavior more cleanly by passing sheet_name=None to read_excel:

dfs = pd.read_excel(file_name, sheet_name=None)

In 0.20 and prior, this was sheetname rather than sheet_name (this is now deprecated in favor of the above):

dfs = pd.read_excel(file_name, sheetname=None)

How to create a XML object from String in Java?

try something like

public static Document loadXML(String xml) throws Exception
{
   DocumentBuilderFactory fctr = DocumentBuilderFactory.newInstance();
   DocumentBuilder bldr = fctr.newDocumentBuilder();
   InputSource insrc = new InputSource(new StringReader(xml));
   return bldr.parse(insrc);
}

What is the difference between procedural programming and functional programming?

Konrad said:

As a consequence, a purely functional program always yields the same value for an input, and the order of evaluation is not well-defined; which means that uncertain values like user input or random values are hard to model in purely functional languages.

The order of evaluation in a purely functional program may be hard(er) to reason about (especially with laziness) or even unimportant but I think that saying it is not well defined makes it sound like you can't tell if your program is going to work at all!

Perhaps a better explanation would be that control flow in functional programs is based on when the value of a function's arguments are needed. The Good Thing about this that in well written programs, state becomes explicit: each function lists its inputs as parameters instead of arbitrarily munging global state. So on some level, it is easier to reason about order of evaluation with respect to one function at a time. Each function can ignore the rest of the universe and focus on what it needs to do. When combined, functions are guaranteed to work the same[1] as they would in isolation.

... uncertain values like user input or random values are hard to model in purely functional languages.

The solution to the input problem in purely functional programs is to embed an imperative language as a DSL using a sufficiently powerful abstraction. In imperative (or non-pure functional) languages this is not needed because you can "cheat" and pass state implicitly and order of evaluation is explicit (whether you like it or not). Because of this "cheating" and forced evaluation of all parameters to every function, in imperative languages 1) you lose the ability to create your own control flow mechanisms (without macros), 2) code isn't inherently thread safe and/or parallelizable by default, 3) and implementing something like undo (time travel) takes careful work (imperative programmer must store a recipe for getting the old value(s) back!), whereas pure functional programming buys you all these things—and a few more I may have forgotten—"for free".

I hope this doesn't sound like zealotry, I just wanted to add some perspective. Imperative programming and especially mixed paradigm programming in powerful languages like C# 3.0 are still totally effective ways to get things done and there is no silver bullet.

[1] ... except possibly with respect memory usage (cf. foldl and foldl' in Haskell).

Convert JSON string to dict using Python

When I started using json, I was confused and unable to figure it out for some time, but finally I got what I wanted
Here is the simple solution

import json
m = {'id': 2, 'name': 'hussain'}
n = json.dumps(m)
o = json.loads(n)
print(o['id'], o['name'])

Explaining Python's '__enter__' and '__exit__'

Using these magic methods (__enter__, __exit__) allows you to implement objects which can be used easily with the with statement.

The idea is that it makes it easy to build code which needs some 'cleandown' code executed (think of it as a try-finally block). Some more explanation here.

A useful example could be a database connection object (which then automagically closes the connection once the corresponding 'with'-statement goes out of scope):

class DatabaseConnection(object):

    def __enter__(self):
        # make a database connection and return it
        ...
        return self.dbconn

    def __exit__(self, exc_type, exc_val, exc_tb):
        # make sure the dbconnection gets closed
        self.dbconn.close()
        ...

As explained above, use this object with the with statement (you may need to do from __future__ import with_statement at the top of the file if you're on Python 2.5).

with DatabaseConnection() as mydbconn:
    # do stuff

PEP343 -- The 'with' statement' has a nice writeup as well.

How to convert milliseconds into a readable date?

You can use datejs and convert in different formate. I have tested some formate and working fine.

var d = new Date(1469433907836);

d.toLocaleString()     // 7/25/2016, 1:35:07 PM
d.toLocaleDateString() // 7/25/2016
d.toDateString()       // Mon Jul 25 2016
d.toTimeString()       // 13:35:07 GMT+0530 (India Standard Time)
d.toLocaleTimeString() // 1:35:07 PM
d.toISOString();       // 2016-07-25T08:05:07.836Z
d.toJSON();            // 2016-07-25T08:05:07.836Z
d.toString();          // Mon Jul 25 2016 13:35:07 GMT+0530 (India Standard Time)
d.toUTCString();       // Mon, 25 Jul 2016 08:05:07 GMT

The program can't start because api-ms-win-crt-runtime-l1-1-0.dll is missing while starting Apache server on my computer

I was facing the same issue. After many tries below solution worked for me.

Before installing VC++ install your windows updates. 1. Go to Start - Control Panel - Windows Update 2. Check for the updates. 3. Install all updates. 4. Restart your system.

After that you can follow the below steps.

@ABHI KUMAR

Download the Visual C++ Redistributable 2015

Visual C++ Redistributable for Visual Studio 2015 (64-bit)

Visual C++ Redistributable for Visual Studio 2015 (32-bit)

(Reinstal if already installed) then restart your computer or use windows updates for download auto.

For link download https://www.microsoft.com/de-de/download/details.aspx?id=48145.

SOAP client in .NET - references or examples?

Here you can find a nice tutorial for calling a NuSOAP-based web-service from a .NET client application. But IMO, you should also consider the WSO2 Web Services Framework for PHP (WSO2 WSF/PHP) for servicing. See WSO2 Web Services Framework for PHP 2.0 Significantly Enhances Industry’s Only PHP Library for Creating Both SOAP and REST Services. There is also a webminar about it.

Now, in .NET world I also encourage the use of WCF, taking into account the interoperability issues. An interoperability example can be found here, but this example uses a PHP-client + WCF-service instead of the opposite. Feel free to implement the PHP-service & WFC-client.

There are some WCF's related open source projects on codeplex.com that I found very productive. These projects are very useful to design & implement Win Forms and Windows Presentation Foundation applications: Smart Client, Web Client and Mobile Client. They can be used in combination with WCF to wisely call any kind of Web services.

Generally speaking, the patterns & practices team summarize good practices & designs in various open source projects that dealing with the .NET platform, specially for the web. So I think it's a good starting point for any design decision related to .NET clients.

How can I go back/route-back on vue-router?

You can use Programmatic Navigation.In order to go back, you use this:

router.go(n) 

Where n can be positive or negative (to go back). This is the same as history.back().So you can have your element like this:

<a @click="$router.go(-1)">back</a>

How to add an ORDER BY clause using CodeIgniter's Active Record methods?

Simple and easy:

$this->db->order_by("name", "asc");
$query = $this->db->get($this->table_name);
return $query->result();

Easy way to password-protect php page

A simple way to protect a file with no requirement for a separate login page - just add this to the top of the page:

Change secretuser and secretpassword to your user/password.

$user = $_POST['user'];
$pass = $_POST['pass'];

if(!($user == "secretuser" && $pass == "secretpassword"))
{
    echo '<html><body><form method="POST" action="'.$_SERVER['REQUEST_URI'].'">
            Username: <input type="text" name="user"></input><br/>
            Password: <input type="password" name="pass"></input><br/>
            <input type="submit" name="submit" value="Login"></input>
            </form></body></html>';
    exit();
}

SQL-Server: Is there a SQL script that I can use to determine the progress of a SQL Server backup or restore process?

For anyone running SQL Server on RDS (AWS), there's a built-in procedure callable in the msdb database which provides comprehensive information for all backup and restore tasks:

exec msdb.dbo.rds_task_status;

This will give a full rundown of each task, its configuration, details about execution (such as completed percentage and total duration), and a task_info column which is immensely helpful when trying to figure out what's wrong with a backup or restore.

How can I extract a number from a string in JavaScript?

For a string such as #box2, this should work:

var thenum = thestring.replace(/^.*?(\d+).*/,'$1');

jsFiddle:

Alternative to mysql_real_escape_string without connecting to DB

From further research, I've found:

http://dev.mysql.com/doc/refman/5.1/en/news-5-1-11.html

Security Fix:

An SQL-injection security hole has been found in multi-byte encoding processing. The bug was in the server, incorrectly parsing the string escaped with the mysql_real_escape_string() C API function.

This vulnerability was discovered and reported by Josh Berkus and Tom Lane as part of the inter-project security collaboration of the OSDB consortium. For more information about SQL injection, please see the following text.

Discussion. An SQL injection security hole has been found in multi-byte encoding processing. An SQL injection security hole can include a situation whereby when a user supplied data to be inserted into a database, the user might inject SQL statements into the data that the server will execute. With regards to this vulnerability, when character set-unaware escaping is used (for example, addslashes() in PHP), it is possible to bypass the escaping in some multi-byte character sets (for example, SJIS, BIG5 and GBK). As a result, a function such as addslashes() is not able to prevent SQL-injection attacks. It is impossible to fix this on the server side. The best solution is for applications to use character set-aware escaping offered by a function such mysql_real_escape_string().

However, a bug was detected in how the MySQL server parses the output of mysql_real_escape_string(). As a result, even when the character set-aware function mysql_real_escape_string() was used, SQL injection was possible. This bug has been fixed.

Workarounds. If you are unable to upgrade MySQL to a version that includes the fix for the bug in mysql_real_escape_string() parsing, but run MySQL 5.0.1 or higher, you can use the NO_BACKSLASH_ESCAPES SQL mode as a workaround. (This mode was introduced in MySQL 5.0.1.) NO_BACKSLASH_ESCAPES enables an SQL standard compatibility mode, where backslash is not considered a special character. The result will be that queries will fail.

To set this mode for the current connection, enter the following SQL statement:

SET sql_mode='NO_BACKSLASH_ESCAPES';

You can also set the mode globally for all clients:

SET GLOBAL sql_mode='NO_BACKSLASH_ESCAPES';

This SQL mode also can be enabled automatically when the server starts by using the command-line option --sql-mode=NO_BACKSLASH_ESCAPES or by setting sql-mode=NO_BACKSLASH_ESCAPES in the server option file (for example, my.cnf or my.ini, depending on your system). (Bug#8378, CVE-2006-2753)

See also Bug#8303.

Algorithm for solving Sudoku

I know I'm late, but this is my version:

from time import perf_counter

board = [
    [8, 0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 3, 6, 0, 0, 0, 0, 0],
    [0, 7, 0, 0, 9, 0, 2, 0, 0],
    [0, 5, 0, 0, 0, 7, 0, 0, 0],
    [0, 0, 0, 0, 4, 5, 7, 0, 0],
    [0, 0, 0, 1, 0, 0, 0, 3, 0],
    [0, 0, 1, 0, 0, 0, 0, 6, 8],
    [0, 0, 8, 5, 0, 0, 0, 1, 0],
    [0, 9, 0, 0, 0, 0, 4, 0, 0]
]


def solve(bo):
    find = find_empty(bo)
    if not find:  # if find is None or False
        return True
    else:
        row, col = find

    for num in range(1, 10):
        if valid(bo, num, (row, col)):
            bo[row][col] = num

            if solve(bo):
                return True

            bo[row][col] = 0

    return False


def valid(bo, num, pos):

    # Check row
    for i in range(len(bo[0])):
        if bo[pos[0]][i] == num and pos[1] != i:
            return False

    # Check column
    for i in range(len(bo)):
        if bo[i][pos[1]] == num and pos[0] != i:
            return False

    # Check box
    box_x = pos[1] // 3
    box_y = pos[0] // 3

    for i in range(box_y*3, box_y*3 + 3):
        for j in range(box_x*3, box_x*3 + 3):
            if bo[i][j] == num and (i, j) != pos:
                return False

    return True


def print_board(bo):
    for i in range(len(bo)):
        if i % 3 == 0:
            if i == 0:
                print(" ?-------------------------?")
            else:
                print(" ?-------------------------?")

        for j in range(len(bo[0])):
            if j % 3 == 0:
                print(" ? ", end=" ")

            if j == 8:
                print(bo[i][j], " ?")
            else:
                print(bo[i][j], end=" ")

    print(" ?-------------------------?")


def find_empty(bo):
    for i in range(len(bo)):
        for j in range(len(bo[0])):
            if bo[i][j] == 0:
                return i, j  # row, column

    return None

print('\n--------------------------------------\n')

print('× Unsolved Suduku :-')
print_board(board)

print('\n--------------------------------------\n')

t1 = perf_counter()
solve(board)
t2 = perf_counter()
print('× Solved Suduku :-')
print_board(board)

print('\n--------------------------------------\n')

print(f' TIME TAKEN = {round(t2-t1,3)} SECONDS')

print('\n--------------------------------------\n')

It uses backtracking. But is not coded by me, it's Tech With Tim's. That list contains the world hardest sudoku, and by implementing the timing function, the time is:

===========================
[Finished in 2.838 seconds]
===========================

But with a simple sudoku puzzle like:

board = [
    [7, 8, 0, 4, 0, 0, 1, 2, 0],
    [6, 0, 0, 0, 7, 5, 0, 0, 9],
    [0, 0, 0, 6, 0, 1, 0, 7, 8],
    [0, 0, 7, 0, 4, 0, 2, 6, 0],
    [0, 0, 1, 0, 5, 0, 9, 3, 0],
    [9, 0, 4, 0, 6, 0, 0, 0, 5],
    [0, 7, 0, 3, 0, 0, 0, 1, 2],
    [1, 2, 0, 0, 0, 7, 4, 0, 0],
    [0, 4, 9, 2, 0, 6, 0, 0, 7]
]

The result is :

===========================
[Finished in 0.011 seconds]
===========================

Pretty fast I can say.

Embed website into my site

Put content from other site in iframe

<iframe src="/othersiteurl" width="100%" height="300">
  <p>Your browser does not support iframes.</p>
</iframe>

Replace text inside td using jQuery having td containing other elements

Using text nodes in jquery is a particularly delicate endeavour and most operations are made to skip them altogether.

Instead of going through the trouble of carefully avoiding the wrong nodes, why not just wrap whatever you need to replace inside a <span> for instance:

<td><span class="replaceme">8: Tap on APN and Enter <B>www</B>.</span></td>

Then:

$('.replaceme').html('Whatever <b>HTML</b> you want here.');

How do I add FTP support to Eclipse?

have you checked RSE (Remote System Explorer) ? I think it's pretty close to what you want to achieve.

a blog post about it, with screenshots

How to create a JavaScript callback for knowing when an image is loaded?

Image.onload() will often work.

To use it, you'll need to be sure to bind the event handler before you set the src attribute.

Related Links:

Example Usage:

_x000D_
_x000D_
    window.onload = function () {_x000D_
_x000D_
        var logo = document.getElementById('sologo');_x000D_
_x000D_
        logo.onload = function () {_x000D_
            alert ("The image has loaded!");  _x000D_
        };_x000D_
_x000D_
        setTimeout(function(){_x000D_
            logo.src = 'https://edmullen.net/test/rc.jpg';         _x000D_
        }, 5000);_x000D_
    };
_x000D_
 <html>_x000D_
    <head>_x000D_
    <title>Image onload()</title>_x000D_
    </head>_x000D_
    <body>_x000D_
_x000D_
    <img src="#" alt="This image is going to load" id="sologo"/>_x000D_
_x000D_
    <script type="text/javascript">_x000D_
_x000D_
    </script>_x000D_
    </body>_x000D_
    </html>
_x000D_
_x000D_
_x000D_

Drop data frame columns by name

If you want remove the columns by reference and avoid the internal copying associated with data.frames then you can use the data.table package and the function :=

You can pass a character vector names to the left hand side of the := operator, and NULL as the RHS.

library(data.table)

df <- data.frame(a=1:10, b=1:10, c=1:10, d=1:10)
DT <- data.table(df)
# or more simply  DT <- data.table(a=1:10, b=1:10, c=1:10, d=1:10) #

DT[, c('a','b') := NULL]

If you want to predefine the names as as character vector outside the call to [, wrap the name of the object in () or {} to force the LHS to be evaluated in the calling scope not as a name within the scope of DT.

del <- c('a','b')
DT <- data.table(a=1:10, b=1:10, c=1:10, d=1:10)
DT[, (del) := NULL]
DT <-  <- data.table(a=1:10, b=1:10, c=1:10, d=1:10)
DT[, {del} := NULL]
# force or `c` would also work.   

You can also use set, which avoids the overhead of [.data.table, and also works for data.frames!

df <- data.frame(a=1:10, b=1:10, c=1:10, d=1:10)
DT <- data.table(df)

# drop `a` from df (no copying involved)

set(df, j = 'a', value = NULL)
# drop `b` from DT (no copying involved)
set(DT, j = 'b', value = NULL)

This project references NuGet package(s) that are missing on this computer

In my case, I had to remove the following from the .csproj file:

<Import Project="$(SolutionDir)\.nuget\NuGet.targets" Condition="Exists('$(SolutionDir)\.nuget\NuGet.targets')" />
<Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
  <PropertyGroup>
    <ErrorText>This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
  </PropertyGroup>
  <Error Condition="!Exists('$(SolutionDir)\.nuget\NuGet.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\.nuget\NuGet.targets'))" />
</Target>

In fact, in this snippet you can see where the error message is coming from.

I was converting from MSBuild-Integrated Package Restore to Automatic Package Restore (http://docs.nuget.org/docs/workflows/migrating-to-automatic-package-restore)

Jest spyOn function called

You're almost there. Although I agree with @Alex Young answer about using props for that, you simply need a reference to the instance before trying to spy on the method.

describe('my sweet test', () => {
 it('clicks it', () => {
    const app = shallow(<App />)
    const instance = app.instance()
    const spy = jest.spyOn(instance, 'myClickFunc')

    instance.forceUpdate();    

    const p = app.find('.App-intro')
    p.simulate('click')
    expect(spy).toHaveBeenCalled()
 })
})

Docs: http://airbnb.io/enzyme/docs/api/ShallowWrapper/instance.html

Batch file: Find if substring is in string (not in a file)

If you are detecting for presence, here's the easiest solution:

SET STRING=F00BAH
SET SUBSTRING=F00
ECHO %STRING% | FINDSTR /C:"%SUBSTRING%" >nul & IF ERRORLEVEL 1 (ECHO CASE TRUE) else (ECHO CASE FALSE)

This works great for dropping the output of windows commands into a boolean variable. Just replace the echo with the command you want to run. You can also string Findstr's together to further qualify a statement using pipes. E.G. for Service Control (SC.exe)

SC QUERY WUAUSERV | findstr /C:"STATE" | FINDSTR /C:"RUNNING" & IF ERRORLEVEL 1 (ECHO case True) else (ECHO CASE FALSE)

That one evaluates the output of SC Query for windows update services which comes out as a multiline text, finds the line containing "state" then finds if the word "running" occurs on that line, and sets the errorlevel accordingly.

Facebook share link - can you customize the message body text?

Facebook does not allow you to change the "What's on your mind?" text box, unless of course you're developing an application for use on Facebook.

How do I exit from a function?

return; // Prematurely return from the method (same keword works in VB, by the way)

Get year, month or day from numpy datetime64

Anon's answer works great for me, but I just need to modify the statement for days

from:

days = dates - dates.astype('datetime64[M]') + 1

to:

days = dates.astype('datetime64[D]') - dates.astype('datetime64[M]') + 1

Android custom dropdown/popup menu

Update: To create a popup menu in android with Kotlin refer my answer here.

To create a popup menu in android with Java:

Create a layout file activity_main.xml under res/layout directory which contains only one button.

Filename: activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    xmlns:tools="http://schemas.android.com/tools"  
    android:layout_width="match_parent"  
    android:layout_height="match_parent"  
    android:paddingBottom="@dimen/activity_vertical_margin"  
    android:paddingLeft="@dimen/activity_horizontal_margin"  
    android:paddingRight="@dimen/activity_horizontal_margin"  
    android:paddingTop="@dimen/activity_vertical_margin"  
    tools:context=".MainActivity" >  

    <Button  
        android:id="@+id/button1"  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:layout_alignParentLeft="true"  
        android:layout_alignParentTop="true"  
        android:layout_marginLeft="62dp"  
        android:layout_marginTop="50dp"  
        android:text="Show Popup" />  

</RelativeLayout>  

Create a file popup_menu.xml under res/menu directory

It contains three items as shown below.

Filename: poupup_menu.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android" >  

    <item  
        android:id="@+id/one"  
        android:title="One"/>  

    <item  
        android:id="@+id/two"  
        android:title="Two"/>  

    <item  
        android:id="@+id/three"  
        android:title="Three"/>  

</menu>  

MainActivity class which displays the popup menu on button click.

Filename: MainActivity.java

public class MainActivity extends Activity {  
    private Button button1;  

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

        button1 = (Button) findViewById(R.id.button1);
        button1.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                //Creating the instance of PopupMenu
                PopupMenu popup = new PopupMenu(MainActivity.this, button1);
                //Inflating the Popup using xml file
                popup.getMenuInflater()
                    .inflate(R.menu.popup_menu, popup.getMenu());

                //registering popup with OnMenuItemClickListener
                popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                    public boolean onMenuItemClick(MenuItem item) {
                        Toast.makeText(
                            MainActivity.this,
                            "You Clicked : " + item.getTitle(),
                            Toast.LENGTH_SHORT
                        ).show();
                        return true;
                    }
                });

                popup.show(); //showing popup menu
            }
        }); //closing the setOnClickListener method
    }
}

To add programmatically:

PopupMenu menu = new PopupMenu(this, view);

menu.getMenu().add("One");
menu.getMenu().add("Two");
menu.getMenu().add("Three");

menu.show();

Follow this link for creating menu programmatically.

How do I configure the proxy settings so that Eclipse can download new plugins?

For me, I go to \eclipse\configuration.settings\org.eclipse.core.net.prefs set the property systemProxiesEnabled to true manually and restart eclipse.

How to debug a bash script?

I think you can try this Bash debugger: http://bashdb.sourceforge.net/.

How to turn NaN from parseInt into 0 for an empty string?

var value = isNaN(parseInt(tbb)) ? 0 : parseInt(tbb);

CSS Animation and Display None

I had the same problem, because as soon as display: x; is in animation, it won't animate.

I ended up in creating custom keyframes, first changing the display value then the other values. May give a better solution.

Or, instead of using display: none; use position: absolute; visibility: hidden; It should work.

How can you float: right in React Native?

You are not supposed to use floats in React Native. React Native leverages the flexbox to handle all that stuff.

In your case, you will probably want the container to have an attribute

justifyContent: 'flex-end'

And about the text taking the whole space, again, you need to take a look at your container.

Here is a link to really great guide on flexbox: A Complete Guide to Flexbox

Getting data posted in between two dates

if your date filed is timestamp into database then this is the easy way to get record

$this->db->where('DATE(RecordDate) >=', date('Y-m-d',strtotime($startDate)));
$this->db->where('DATE(RecordDate) <=', date('Y-m-d',strtotime($endDate)));

How to make a JSONP request from Javascript without JQuery?

Please find below JavaScript example to make a JSONP call without JQuery:

Also, you can refer my GitHub repository for reference.

https://github.com/shedagemayur/JavaScriptCode/tree/master/jsonp

_x000D_
_x000D_
window.onload = function(){_x000D_
    var callbackMethod = 'callback_' + new Date().getTime();_x000D_
_x000D_
    var script = document.createElement('script');_x000D_
    script.src = 'https://jsonplaceholder.typicode.com/users/1?callback='+callbackMethod;_x000D_
_x000D_
    document.body.appendChild(script);_x000D_
_x000D_
    window[callbackMethod] = function(data){_x000D_
        delete window[callbackMethod];_x000D_
        document.body.removeChild(script);_x000D_
        console.log(data);_x000D_
    }_x000D_
}
_x000D_
_x000D_
_x000D_

iText - add content to existing PDF file

Document document = new Document();
    PdfWriter writer = PdfWriter.getInstance(document, 
        new FileOutputStream("E:/TextFieldForm.pdf"));
    document.open();

    PdfPTable table = new PdfPTable(2);
    table.getDefaultCell().setPadding(5f); // Code 1
    table.setHorizontalAlignment(Element.ALIGN_LEFT);
    PdfPCell cell;      

    // Code 2, add name TextField       
    table.addCell("Name"); 
    TextField nameField = new TextField(writer, 
        new Rectangle(0,0,200,10), "nameField");
    nameField.setBackgroundColor(Color.WHITE);
    nameField.setBorderColor(Color.BLACK);
    nameField.setBorderWidth(1);
    nameField.setBorderStyle(PdfBorderDictionary.STYLE_SOLID);
    nameField.setText("");
    nameField.setAlignment(Element.ALIGN_LEFT);
    nameField.setOptions(TextField.REQUIRED);               
    cell = new PdfPCell();
    cell.setMinimumHeight(10);
    cell.setCellEvent(new FieldCell(nameField.getTextField(), 
        200, writer));
    table.addCell(cell);

    // force upper case javascript
    writer.addJavaScript(
        "var nameField = this.getField('nameField');" +
        "nameField.setAction('Keystroke'," +
        "'forceUpperCase()');" +
        "" +
        "function forceUpperCase(){" +
        "if(!event.willCommit)event.change = " +
        "event.change.toUpperCase();" +
        "}");


    // Code 3, add empty row
    table.addCell("");
    table.addCell("");


    // Code 4, add age TextField
    table.addCell("Age");
    TextField ageComb = new TextField(writer, new Rectangle(0,
         0, 30, 10), "ageField");
    ageComb.setBorderColor(Color.BLACK);
    ageComb.setBorderWidth(1);
    ageComb.setBorderStyle(PdfBorderDictionary.STYLE_SOLID);
    ageComb.setText("12");
    ageComb.setAlignment(Element.ALIGN_RIGHT);
    ageComb.setMaxCharacterLength(2);
    ageComb.setOptions(TextField.COMB | 
        TextField.DO_NOT_SCROLL);
    cell = new PdfPCell();
    cell.setMinimumHeight(10);
    cell.setCellEvent(new FieldCell(ageComb.getTextField(), 
        30, writer));
    table.addCell(cell);

    // validate age javascript
    writer.addJavaScript(
        "var ageField = this.getField('ageField');" +
        "ageField.setAction('Validate','checkAge()');" +
        "function checkAge(){" +
        "if(event.value < 12){" +
        "app.alert('Warning! Applicant\\'s age can not" +
        " be younger than 12.');" +
        "event.value = 12;" +
        "}}");      



    // add empty row
    table.addCell("");
    table.addCell("");


    // Code 5, add age TextField
    table.addCell("Comment");
    TextField comment = new TextField(writer, 
        new Rectangle(0, 0,200, 100), "commentField");
    comment.setBorderColor(Color.BLACK);
    comment.setBorderWidth(1);
    comment.setBorderStyle(PdfBorderDictionary.STYLE_SOLID);
    comment.setText("");
    comment.setOptions(TextField.MULTILINE | 
        TextField.DO_NOT_SCROLL);
    cell = new PdfPCell();
    cell.setMinimumHeight(100);
    cell.setCellEvent(new FieldCell(comment.getTextField(), 
        200, writer));
    table.addCell(cell);


    // check comment characters length javascript
    writer.addJavaScript(
        "var commentField = " +
        "this.getField('commentField');" +
        "commentField" +
        ".setAction('Keystroke','checkLength()');" +
        "function checkLength(){" +
        "if(!event.willCommit && " +
        "event.value.length > 100){" +
        "app.alert('Warning! Comment can not " +
        "be more than 100 characters.');" +
        "event.change = '';" +
        "}}");          

    // add empty row
    table.addCell("");
    table.addCell("");


    // Code 6, add submit button    
    PushbuttonField submitBtn = new PushbuttonField(writer,
            new Rectangle(0, 0, 35, 15),"submitPOST");
    submitBtn.setBackgroundColor(Color.GRAY);
    submitBtn.
        setBorderStyle(PdfBorderDictionary.STYLE_BEVELED);
    submitBtn.setText("POST");
    submitBtn.setOptions(PushbuttonField.
        VISIBLE_BUT_DOES_NOT_PRINT);
    PdfFormField submitField = submitBtn.getField();
    submitField.setAction(PdfAction
    .createSubmitForm("",null, PdfAction.SUBMIT_HTML_FORMAT));

    cell = new PdfPCell();
    cell.setMinimumHeight(15);
    cell.setCellEvent(new FieldCell(submitField, 35, writer));
    table.addCell(cell);



    // Code 7, add reset button
    PushbuttonField resetBtn = new PushbuttonField(writer,
            new Rectangle(0, 0, 35, 15), "reset");
    resetBtn.setBackgroundColor(Color.GRAY);
    resetBtn.setBorderStyle(
        PdfBorderDictionary.STYLE_BEVELED);
    resetBtn.setText("RESET");
    resetBtn
    .setOptions(
        PushbuttonField.VISIBLE_BUT_DOES_NOT_PRINT);
    PdfFormField resetField = resetBtn.getField();
    resetField.setAction(PdfAction.createResetForm(null, 0));
    cell = new PdfPCell();
    cell.setMinimumHeight(15);
    cell.setCellEvent(new FieldCell(resetField, 35, writer));
    table.addCell(cell);        

    document.add(table);
    document.close();
}


class FieldCell implements PdfPCellEvent{

    PdfFormField formField;
    PdfWriter writer;
    int width;

    public FieldCell(PdfFormField formField, int width, 
        PdfWriter writer){
        this.formField = formField;
        this.width = width;
        this.writer = writer;
    }

    public void cellLayout(PdfPCell cell, Rectangle rect, 
        PdfContentByte[] canvas){
        try{
            // delete cell border
            PdfContentByte cb = canvas[PdfPTable
                .LINECANVAS];
            cb.reset();

            formField.setWidget(
                new Rectangle(rect.left(), 
                    rect.bottom(), 
                    rect.left()+width, 
                    rect.top()), 
                    PdfAnnotation
                    .HIGHLIGHT_NONE);

            writer.addAnnotation(formField);
        }catch(Exception e){
            System.out.println(e);
        }
    }
}

Correct way to populate an Array with a Range in Ruby

Check this:

a = [*(1..10), :top, *10.downto( 1 )]

Auto height of div

According to this, you need to assign a height to the element in which the div is contained in order for 100% height to work. Does that work for you?

Get all child elements

Yes, you can use find_elements_by_ to retrieve children elements into a list. See the python bindings here: http://selenium-python.readthedocs.io/locating-elements.html

Example HTML:

<ul class="bar">
    <li>one</li>
    <li>two</li>
    <li>three</li>
</ul>

You can use the find_elements_by_ like so:

parentElement = driver.find_element_by_class_name("bar")
elementList = parentElement.find_elements_by_tag_name("li")

If you want help with a specific case, you can edit your post with the HTML you're looking to get parent and children elements from.

Call an activity method from a fragment

Here is how I did this:

first make interface

interface NavigationInterface {
    fun closeActivity()
}

next make sure activity implements interface and overrides interface method(s)

class NotesActivity : AppCompatActivity(), NavigationInterface {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_notes)
        setSupportActionBar(findViewById(R.id.toolbar))
    }

    override fun closeActivity() {
        this.finish()
    }
}

then make sure to create interface listener in fragment

private lateinit var navigationInterface: NavigationInterface

override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
): View? {
    //establish interface communication
    activity?.let {
        instantiateNavigationInterface(it)
    }
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment_notes_info, container, false)
}

private fun instantiateNavigationInterface(context: FragmentActivity) {
    navigationInterface = context as NavigationInterface
}

then you can make calls like such:

view.findViewById<Button>(R.id.button_second).setOnClickListener {
    navigationInterface.closeActivity()
}

Double vs. BigDecimal?

BigDecimal is Oracle's arbitrary-precision numerical library. BigDecimal is part of the Java language and is useful for a variety of applications ranging from the financial to the scientific (that's where sort of am).

There's nothing wrong with using doubles for certain calculations. Suppose, however, you wanted to calculate Math.Pi * Math.Pi / 6, that is, the value of the Riemann Zeta Function for a real argument of two (a project I'm currently working on). Floating-point division presents you with a painful problem of rounding error.

BigDecimal, on the other hand, includes many options for calculating expressions to arbitrary precision. The add, multiply, and divide methods as described in the Oracle documentation below "take the place" of +, *, and / in BigDecimal Java World:

http://docs.oracle.com/javase/7/docs/api/java/math/BigDecimal.html

The compareTo method is especially useful in while and for loops.

Be careful, however, in your use of constructors for BigDecimal. The string constructor is very useful in many cases. For instance, the code

BigDecimal onethird = new BigDecimal("0.33333333333");

utilizes a string representation of 1/3 to represent that infinitely-repeating number to a specified degree of accuracy. The round-off error is most likely somewhere so deep inside the JVM that the round-off errors won't disturb most of your practical calculations. I have, from personal experience, seen round-off creep up, however. The setScale method is important in these regards, as can be seen from the Oracle documentation.

.htaccess: Invalid command 'RewriteEngine', perhaps misspelled or defined by a module not included in the server configuration

or defined by a module not included in the server configuration

Check to make sure you have mod_rewrite enabled.

From: https://webdevdoor.com/php/mod_rewrite-windows-apache-url-rewriting

  1. Find the httpd.conf file (usually you will find it in a folder called conf, config or something along those lines)
  2. Inside the httpd.conf file uncomment the line LoadModule rewrite_module modules/mod_rewrite.so (remove the pound '#' sign from in front of the line)
  3. Also find the line ClearModuleList is uncommented then find and make sure that the line AddModule mod_rewrite.c is not commented out.

If the LoadModule rewrite_module modules/mod_rewrite.so line is missing from the httpd.conf file entirely, just add it.

Sample command

To enable the module in a standard ubuntu do this:

a2enmod rewrite
systemctl restart apache2

SyntaxError: Non-ASCII character '\xa3' in file when function returns '£'

The error message tells you exactly what's wrong. The Python interpreter needs to know the encoding of the non-ASCII character.

If you want to return U+00A3 then you can say

return u'\u00a3'

which represents this character in pure ASCII by way of a Unicode escape sequence. If you want to return a byte string containing the literal byte 0xA3, that's

return b'\xa3'

(where in Python 2 the b is implicit; but explicit is better than implicit).

The linked PEP in the error message instructs you exactly how to tell Python "this file is not pure ASCII; here's the encoding I'm using". If the encoding is UTF-8, that would be

# coding=utf-8

or the Emacs-compatible

# -*- encoding: utf-8 -*-

If you don't know which encoding your editor uses to save this file, examine it with something like a hex editor and some googling. The Stack Overflow tag has a tag info page with more information and some troubleshooting tips.

In so many words, outside of the 7-bit ASCII range (0x00-0x7F), Python can't and mustn't guess what string a sequence of bytes represents. https://tripleee.github.io/8bit#a3 shows 21 possible interpretations for the byte 0xA3 and that's only from the legacy 8-bit encodings; but it could also very well be the first byte of a multi-byte encoding. But in fact, I would guess you are actually using Latin-1, so you should have

# coding: latin-1

as the first or second line of your source file. Anyway, without knowledge of which character the byte is supposed to represent, a human would not be able to guess this, either.

A caveat: coding: latin-1 will definitely remove the error message (because there are no byte sequences which are not technically permitted in this encoding), but might produce completely the wrong result when the code is interpreted if the actual encoding is something else. You really have to know the encoding of the file with complete certainty when you declare the encoding.

Is JavaScript's "new" keyword considered harmful?

I am newbie to Javascript so maybe I am just not too experienced in providing a good view point to this. Yet I want to share my view on this "new" thing.

I have come from the C# world where using the keyword "new" is so natural that it is the factory design pattern that looks weird to me.

When I first code in Javascript, I don't realize that there is the "new" keyword and code like the one in YUI pattern and it doesn't take me long to run into disaster. I lose track of what a particular line is supposed to be doing when looking back the code I've written. More chaotic is that my mind can't really transit between object instances boundaries when I am "dry-running" the code.

Then, I found the "new" keyword which to me, it "separate" things. With the new keyword, it creates things. Without the new keyword, I know I won't confuse it with creating things unless the function I am invoking gives me strong clues of that.

For instance, with var bar=foo(); I have no clues as what bar could possibly be.... Is it a return value or is it a newly created object? But with var bar = new foo(); I know for sure bar is an object.

Get everything after the dash in a string in JavaScript

You can use split method for it. And if you should take string from specific pattern you can use split with req. exp.:

_x000D_
_x000D_
var string = "sometext-20202";
console.log(string.split(/-(.*)/)[1])
_x000D_
_x000D_
_x000D_

How do I fix 'Invalid character value for cast specification' on a date column in flat file?

The proper data type for "2010-12-20 00:00:00.0000000" value is DATETIME2(7) / DT_DBTIME2 ().

But used data type for CYCLE_DATE field is DATETIME - DT_DATE. This means milliseconds precision with accuracy down to every third millisecond (yyyy-mm-ddThh:mi:ss.mmL where L can be 0,3 or 7).

The solution is to change CYCLE_DATE date type to DATETIME2 - DT_DBTIME2.

jquery .live('click') vs .click()

remember that the use of "live" is for "jQuery 1.3" or higher

in version "jQuery 1.4.3" or higher is used "delegate"

and version "jQuery 1.7 +" or higher is used "on"

$( selector ).live( events, data, handler ); // jQuery 1.3+
$( document ).delegate( selector, events, data, handler ); // jQuery 1.4.3+
$( document ).on( events, selector, data, handler ); // jQuery 1.7+

As of jQuery 1.7, the .live() method is deprecated.

check http://api.jquery.com/live/

Regards, Fernando

How do I convert a datetime to date?

From the documentation:

datetime.datetime.date()

Return date object with same year, month and day.

How do I remove time part from JavaScript date?

The previous answers are fine, just adding my preferred way of handling this:

var timePortion = myDate.getTime() % (3600 * 1000 * 24);
var dateOnly = new Date(myDate - timePortion);

If you start with a string, you first need to parse it like so:

var myDate = new Date(dateString);

And if you come across timezone related problems as I have, this should fix it:

var timePortion = (myDate.getTime() - myDate.getTimezoneOffset() * 60 * 1000) % (3600 * 1000 * 24);

Tests not running in Test Explorer

Have tried many options with Visual Studio 2019 Version 16.4.6 and Microsoft.VisualStudio.TestTools.UnitTesting, but for now the only way to run tests successfully was by invoking next command in console

dotnet test

Tests are discovered in Test Explorer but outcome is "Not Run".

Updating Visual Studio did not help.

Have resolved issue with "No test matches the given testcase filter FullyQualifiedName" by running updates to latest version for next packages:

Microsoft.NET.Test.Sdk
MSTest.TestAdapter
MSTest.TestFramework

How to check if std::map contains a key without doing insert?

Use my_map.count( key ); it can only return 0 or 1, which is essentially the Boolean result you want.

Alternately my_map.find( key ) != my_map.end() works too.

How do I draw a set of vertical lines in gnuplot?

You can use the grid feature for the second unused axis x2, which is the most natural way of drawing a set of regular spaced lines.

set grid x2tics
set x2tics 10 format "" scale 0

In general, the grid is drawn at the same position as the tics on the axis. In case the position of the lines does not correspond to the tics position, gnuplot provides an additional set of tics, called x2tics. format "" and scale 0 hides the x2tics so you only see the grid lines.

You can style the lines as usual with linewith, linecolor.

How do I get the Date & Time (VBS)

Here's various date and time information you can pull in vbscript running under Windows Script Host (WSH):

Now   = 2/29/2016 1:02:03 PM
Date  = 2/29/2016
Time  = 1:02:03 PM
Timer = 78826.31     ' seconds since midnight

FormatDateTime(Now)                = 2/29/2016 1:02:03 PM
FormatDateTime(Now, vbGeneralDate) = 2/29/2016 1:02:03 PM
FormatDateTime(Now, vbLongDate)    = Monday, February 29, 2016
FormatDateTime(Now, vbShortDate)   = 2/29/2016
FormatDateTime(Now, vbLongTime)    = 1:02:03 PM
FormatDateTime(Now, vbShortTime)   = 13:02

Year(Now)   = 2016
Month(Now)  = 2
Day(Now)    = 29
Hour(Now)   = 13
Minute(Now) = 2
Second(Now) = 3

Year(Date)   = 2016
Month(Date)  = 2
Day(Date)    = 29

Hour(Time)   = 13
Minute(Time) = 2
Second(Time) = 3

Function LPad (str, pad, length)
    LPad = String(length - Len(str), pad) & str
End Function

LPad(Month(Date), "0", 2)    = 02
LPad(Day(Date), "0", 2)      = 29
LPad(Hour(Time), "0", 2)     = 13
LPad(Minute(Time), "0", 2)   = 02
LPad(Second(Time), "0", 2)   = 03

Weekday(Now)                     = 2
WeekdayName(Weekday(Now), True)  = Mon
WeekdayName(Weekday(Now), False) = Monday
WeekdayName(Weekday(Now))        = Monday

MonthName(Month(Now), True)  = Feb
MonthName(Month(Now), False) = February
MonthName(Month(Now))        = February

Set os = GetObject("winmgmts:root\cimv2:Win32_OperatingSystem=@")
os.LocalDateTime = 20131204215346.562000-300
Left(os.LocalDateTime, 4)    = 2013 ' year
Mid(os.LocalDateTime, 5, 2)  = 12   ' month
Mid(os.LocalDateTime, 7, 2)  = 04   ' day
Mid(os.LocalDateTime, 9, 2)  = 21   ' hour
Mid(os.LocalDateTime, 11, 2) = 53   ' minute
Mid(os.LocalDateTime, 13, 2) = 46   ' second

Dim wmi : Set wmi = GetObject("winmgmts:root\cimv2")
Set timeZones = wmi.ExecQuery("SELECT Bias, Caption FROM Win32_TimeZone")
For Each tz In timeZones
    tz.Bias    = -300
    tz.Caption = (UTC-05:00) Eastern Time (US & Canada)
Next

Source

How to get default gateway in Mac OSX

I would use something along these lines...

 netstat -rn | grep "default" | awk '{print $2}'

How to check if a MySQL query using the legacy API was successful?

If your query failed, you'll receive a FALSE return value. Otherwise you'll receive a resource/TRUE.

$result = mysql_query($query);

if(!$result){
    /* check for error, die, etc */
}

Basically as long as it's not false, you're fine. Afterwards, you can continue your code.

if(!$result)

This part of the code actually runs your query.

RSpec: how to test if a method was called?

In the new rspec expect syntax this would be:

expect(subject).to receive(:bar).with("an argument I want")

Arduino Sketch upload issue - avrdude: stk500_recv(): programmer is not responding

For me it was as simple as setting the right ports.

To set that, go to menu ToolsPort, and change from COM1 to the appropriate port.

After this my program worked correctly.

Fatal error: Maximum execution time of 300 seconds exceeded

WAMP USERS:

1) Go to C:\wamp\apps\phpmyadmin

2) Open config.inc

3) Add $cfg['ExecTimeLimit'] = ’3600'; to the file.

4) Save the file and restart the server.

This file overwrites the php.ini and will work for you!

Get all Attributes from a HTML element with Javascript/jQuery

Simple:

var element = $("span[name='test']");
$(element[0].attributes).each(function() {
console.log(this.nodeName+':'+this.nodeValue);});

Adding headers to requests module

You can also do this to set a header for all future gets for the Session object, where x-test will be in all s.get() calls:

s = requests.Session()
s.auth = ('user', 'pass')
s.headers.update({'x-test': 'true'})

# both 'x-test' and 'x-test2' are sent
s.get('http://httpbin.org/headers', headers={'x-test2': 'true'})

from: http://docs.python-requests.org/en/latest/user/advanced/#session-objects

Reading rather large json files in Python

The issue here is that JSON, as a format, is generally parsed in full and then handled in-memory, which for such a large amount of data is clearly problematic.

The solution to this is to work with the data as a stream - reading part of the file, working with it, and then repeating.

The best option appears to be using something like ijson - a module that will work with JSON as a stream, rather than as a block file.

Edit: Also worth a look - kashif's comment about json-streamer and Henrik Heino's comment about bigjson.

How to open a new form from another form

private void Button1_Click(object sender, EventArgs e)
{
    NewForm newForm = new NewForm();    //Create the New Form Object
    this.Hide();    //Hide the Old Form
    newForm.ShowDialog();    //Show the New Form
    this.Close();    //Close the Old Form
}

How to read keyboard-input?

Non-blocking, multi-threaded example:

As blocking on keyboard input (since the input() function blocks) is frequently not what we want to do (we'd frequently like to keep doing other stuff), here's a very-stripped-down multi-threaded example to demonstrate how to keep running your main application while still reading in keyboard inputs whenever they arrive.

This works by creating one thread to run in the background, continually calling input() and then passing any data it receives to a queue.

In this way, your main thread is left to do anything it wants, receiving the keyboard input data from the first thread whenever there is something in the queue.

1. Bare Python 3 code example (no comments):

import threading
import queue
import time

def read_kbd_input(inputQueue):
    print('Ready for keyboard input:')
    while (True):
        input_str = input()
        inputQueue.put(input_str)

def main():
    EXIT_COMMAND = "exit"
    inputQueue = queue.Queue()

    inputThread = threading.Thread(target=read_kbd_input, args=(inputQueue,), daemon=True)
    inputThread.start()

    while (True):
        if (inputQueue.qsize() > 0):
            input_str = inputQueue.get()
            print("input_str = {}".format(input_str))

            if (input_str == EXIT_COMMAND):
                print("Exiting serial terminal.")
                break
            
            # Insert your code here to do whatever you want with the input_str.

        # The rest of your program goes here.

        time.sleep(0.01) 
    print("End.")

if (__name__ == '__main__'): 
    main()

2. Same Python 3 code as above, but with extensive explanatory comments:

"""
read_keyboard_input.py

Gabriel Staples
www.ElectricRCAircraftGuy.com
14 Nov. 2018

References:
- https://pyserial.readthedocs.io/en/latest/pyserial_api.html
- *****https://www.tutorialspoint.com/python/python_multithreading.htm
- *****https://en.wikibooks.org/wiki/Python_Programming/Threading
- https://stackoverflow.com/questions/1607612/python-how-do-i-make-a-subclass-from-a-superclass
- https://docs.python.org/3/library/queue.html
- https://docs.python.org/3.7/library/threading.html

To install PySerial: `sudo python3 -m pip install pyserial`

To run this program: `python3 this_filename.py`

"""

import threading
import queue
import time

def read_kbd_input(inputQueue):
    print('Ready for keyboard input:')
    while (True):
        # Receive keyboard input from user.
        input_str = input()
        
        # Enqueue this input string.
        # Note: Lock not required here since we are only calling a single Queue method, not a sequence of them 
        # which would otherwise need to be treated as one atomic operation.
        inputQueue.put(input_str)

def main():

    EXIT_COMMAND = "exit" # Command to exit this program

    # The following threading lock is required only if you need to enforce atomic access to a chunk of multiple queue
    # method calls in a row.  Use this if you have such a need, as follows:
    # 1. Pass queueLock as an input parameter to whichever function requires it.
    # 2. Call queueLock.acquire() to obtain the lock.
    # 3. Do your series of queue calls which need to be treated as one big atomic operation, such as calling
    # inputQueue.qsize(), followed by inputQueue.put(), for example.
    # 4. Call queueLock.release() to release the lock.
    # queueLock = threading.Lock() 

    #Keyboard input queue to pass data from the thread reading the keyboard inputs to the main thread.
    inputQueue = queue.Queue()

    # Create & start a thread to read keyboard inputs.
    # Set daemon to True to auto-kill this thread when all other non-daemonic threads are exited. This is desired since
    # this thread has no cleanup to do, which would otherwise require a more graceful approach to clean up then exit.
    inputThread = threading.Thread(target=read_kbd_input, args=(inputQueue,), daemon=True)
    inputThread.start()

    # Main loop
    while (True):

        # Read keyboard inputs
        # Note: if this queue were being read in multiple places we would need to use the queueLock above to ensure
        # multi-method-call atomic access. Since this is the only place we are removing from the queue, however, in this
        # example program, no locks are required.
        if (inputQueue.qsize() > 0):
            input_str = inputQueue.get()
            print("input_str = {}".format(input_str))

            if (input_str == EXIT_COMMAND):
                print("Exiting serial terminal.")
                break # exit the while loop
            
            # Insert your code here to do whatever you want with the input_str.

        # The rest of your program goes here.

        # Sleep for a short time to prevent this thread from sucking up all of your CPU resources on your PC.
        time.sleep(0.01) 
    
    print("End.")

# If you run this Python file directly (ex: via `python3 this_filename.py`), do the following:
if (__name__ == '__main__'): 
    main()

Sample output:

$ python3 read_keyboard_input.py
Ready for keyboard input:
hey
input_str = hey
hello
input_str = hello
7000
input_str = 7000
exit
input_str = exit
Exiting serial terminal.
End.

The Python Queue library is thread-safe:

Note that Queue.put() and Queue.get() and other Queue class methods are thread-safe! That means they implement all the internal locking semantics required for inter-thread operations, so each function call in the queue class can be considered as a single, atomic operation. See the notes at the top of the documentation: https://docs.python.org/3/library/queue.html (emphasis added):

The queue module implements multi-producer, multi-consumer queues. It is especially useful in threaded programming when information must be exchanged safely between multiple threads. The Queue class in this module implements all the required locking semantics.

References:

  1. https://pyserial.readthedocs.io/en/latest/pyserial_api.html
  2. *****https://www.tutorialspoint.com/python/python_multithreading.htm
  3. *****https://en.wikibooks.org/wiki/Python_Programming/Threading
  4. Python: How do I make a subclass from a superclass?
  5. https://docs.python.org/3/library/queue.html
  6. https://docs.python.org/3.7/library/threading.html

Related/Cross-Linked:

  1. PySerial non-blocking read loop

How can I use pointers in Java?

All objects in java are passed to functions by reference copy except primitives.

In effect, this means that you are sending a copy of the pointer to the original object rather than a copy of the object itself.

Please leave a comment if you want an example to understand this.

Two Divs on the same row and center align both of them

I would vote against display: inline-block since its not supported across browsers, IE < 8 specifically.

.wrapper {
    width:500px; /* Adjust to a total width of both .left and .right */
    margin: 0 auto;
}
.left {
    float: left;
    width: 49%; /* Not 50% because of 1px border. */
    border: 1px solid #000;
}
.right {
    float: right;
    width: 49%; /* Not 50% because of 1px border. */
    border: 1px solid #F00;
}

<div class="wrapper">
    <div class="left">Div 1</div>
    <div class="right">Div 2</div>
</div>

EDIT: If no spacing between the cells is desired just change both .left and .right to use float: left;

What's the difference between Unicode and UTF-8?

UTF-16 and UTF-8 are both encodings of Unicode. They are both Unicode; one is not more Unicode than the other.

Don't let an unfortunate historical artifact from Microsoft confuse you.

How to make a window always stay on top in .Net?

Form.TopMost will work unless the other program is creating topmost windows.

There is no way to create a window that is not covered by new topmost windows of another process. Raymond Chen explained why.

JSchException: Algorithm negotiation fail

Make sure that you're using the latest version of JSch. I had this exact same problem when using JSch 0.1.31 and trying to connect to a RedHat 5 server. Updating to the latest version solved the problem.

Cast from VARCHAR to INT - MySQL

As described in Cast Functions and Operators:

The type for the result can be one of the following values:

  • BINARY[(N)]
  • CHAR[(N)]
  • DATE
  • DATETIME
  • DECIMAL[(M[,D])]
  • SIGNED [INTEGER]
  • TIME
  • UNSIGNED [INTEGER]

Therefore, you should use:

SELECT CAST(PROD_CODE AS UNSIGNED) FROM PRODUCT

Node.js fs.readdir recursive directory search

I recommend using node-glob to accomplish that task.

var glob = require( 'glob' );  

glob( 'dirname/**/*.js', function( err, files ) {
  console.log( files );
});

AngularJS ui-router login authentication

I have another solution: that solution works perfectly when you have only content you want to show when you are logged in. Define a rule where you checking if you are logged in and its not path of whitelist routes.

$urlRouterProvider.rule(function ($injector, $location) {
   var UserService = $injector.get('UserService');
   var path = $location.path(), normalized = path.toLowerCase();

   if (!UserService.isLoggedIn() && path.indexOf('login') === -1) {
     $location.path('/login/signin');
   }
});

In my example i ask if i am not logged in and the current route i want to route is not part of `/login', because my whitelist routes are the following

/login/signup // registering new user
/login/signin // login to app

so i have instant access to this two routes and every other route will be checked if you are online.

Here is my whole routing file for the login module

export default (
  $stateProvider,
  $locationProvider,
  $urlRouterProvider
) => {

  $stateProvider.state('login', {
    parent: 'app',
    url: '/login',
    abstract: true,
    template: '<ui-view></ui-view>'
  })

  $stateProvider.state('signin', {
    parent: 'login',
    url: '/signin',
    template: '<login-signin-directive></login-signin-directive>'
  });

  $stateProvider.state('lock', {
    parent: 'login',
    url: '/lock',
    template: '<login-lock-directive></login-lock-directive>'
  });

  $stateProvider.state('signup', {
    parent: 'login',
    url: '/signup',
    template: '<login-signup-directive></login-signup-directive>'
  });

  $urlRouterProvider.rule(function ($injector, $location) {
    var UserService = $injector.get('UserService');
    var path = $location.path();

    if (!UserService.isLoggedIn() && path.indexOf('login') === -1) {
         $location.path('/login/signin');
    }
  });

  $urlRouterProvider.otherwise('/error/not-found');
}

() => { /* code */ } is ES6 syntax, use instead function() { /* code */ }

Codeigniter : calling a method of one controller from other

You can do like

$result= file_get_contents(site_url('[ADDRESS TO CONTROLLER FUNCTION]'));

Replace [ADDRESS TO CONTROLLER FUNCTION] by the way we use in site_url();

You need to echo output in controller function instead of return.

Have log4net use application config file for configuration data

Have you tried adding a configsection handler to your app.config? e.g.

<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>

UIAlertController custom font, size, color

To change the color of one button like CANCEL to the red color you can use this style property called UIAlertActionStyle.destructive :

let prompt = UIAlertController.init(title: "Reset Password", message: "Enter Your E-mail :", preferredStyle: .alert)
        let okAction = UIAlertAction.init(title: "Submit", style: .default) { (action) in
              //your code
}

let cancelAction = UIAlertAction.init(title: "Cancel", style: UIAlertActionStyle.destructive) { (action) in
                //your code
        }
        prompt.addTextField(configurationHandler: nil)
        prompt.addAction(okAction)
        prompt.addAction(cancelAction)
        present(prompt, animated: true, completion: nil);

How do I include inline JavaScript in Haml?

So i tried the above :javascript which works :) However HAML wraps the generated code in CDATA like so:

<script type="text/javascript">
  //<![CDATA[
    $(document).ready( function() {
       $('body').addClass( 'test' );
    } );
  //]]>
</script>

The following HAML will generate the typical tag for including (for example) typekit or google analytics code.

 %script{:type=>"text/javascript"}
  //your code goes here - dont forget the indent!

ionic build Android | error: No installed build tools found. Please install the Android build tools

Please install the Android build tools version 19.1.0 or higher.

The following commands can update Android SDK on Ubuntu quickly and fix the above error:

android list sdk --all
android update sdk -u -a -t 19
android update sdk -u -a -t 20

How to add form validation pattern in Angular 2?

Since version 2.0.0-beta.8 (2016-03-02), Angular now includes a Validators.pattern regex validator.

See the CHANGELOG

Python: TypeError: object of type 'NoneType' has no len()

I was faces this issue but after change object into str, problem solved. str(fname).isalpha():

How to use Git?

To answer your questions directly rather than pointing you at documentation:

1) In order to keep it up to date, do a git pull and that will pull down the latest changes in the repository, on the branch that you're currently using (which is generally master)

2) I don't think there's something (widely available) that'll do this for you. To update them follow 1) for all projects.

Directory Chooser in HTML page

If you do not have too many folders then I suggest you use if statements to choose an upload folder depending on the user input details. E.g.

String user= request.getParameter("username");
if (user=="Alfred"){
//Path A;
}
if (user=="other"){
//Path B;
}

Is there a better way to refresh WebView?

The best solution is to just do webView.loadUrl( "javascript:window.location.reload( true )" );. This should work on all versions and doesn't introduce new history entries.

Any good, visual HTML5 Editor or IDE?

Topstyle 4 is the only one I've com e across with HTML5 (and CSS3) support. Its early stages but it works enough for the most part.

"ImportError: No module named" when trying to run Python script

This is probably caused by different python versions installed on your system, i.e. python2 or python3.

Run command $ pip --version and $ pip3 --version to check which pip is from at Python 3x. E.g. you should see version information like below:

pip 19.0.3 from /usr/local/lib/python3.7/site-packages/pip (python 3.7)

Then run the example.py script with below command

$ python3 example.py

AngularJS ng-if with multiple conditions

HTML code

<div ng-app>
<div ng-controller='ctrl'>
    <div ng-class='whatClassIsIt(call.state[0])'>{{call.state[0]}}</div>
    <div ng-class='whatClassIsIt(call.state[1])'>{{call.state[1]}}</div>
    <div ng-class='whatClassIsIt(call.state[2])'>{{call.state[2]}}</div>
    <div ng-class='whatClassIsIt(call.state[3])'>{{call.state[3]}}</div>
    <div ng-class='whatClassIsIt(call.state[4])'>{{call.state[4]}}</div>
    <div ng-class='whatClassIsIt(call.state[5])'>{{call.state[5]}}</div>
    <div ng-class='whatClassIsIt(call.state[6])'>{{call.state[6]}}</div>
    <div ng-class='whatClassIsIt(call.state[7])'>{{call.state[7]}}</div>
</div>

JavaScript Code

function ctrl($scope){
$scope.call={state:['second','first','nothing','Never', 'Gonna', 'Give', 'You', 'Up']}


$scope.whatClassIsIt= function(someValue){
     if(someValue=="first")
            return "ClassA"
     else if(someValue=="second")
         return "ClassB";
    else
         return "ClassC";
}
}

check if "it's a number" function in Oracle

well, you could create the is_number function to call so your code works.

create or replace function is_number(param varchar2) return boolean
 as
   ret number;
 begin
    ret := to_number(param);
    return true;
 exception
    when others then return false;
 end;

EDIT: Please defer to Justin's answer. Forgot that little detail for a pure SQL call....

Securing a password in a properties file

What about providing a custom N-Factor authentication mechanism?

Before combining available methods, let's assume we can perform the following:

1) Hard-code inside the Java program

2) Store in a .properties file

3) Ask user to type password from command line

4) Ask user to type password from a form

5) Ask user to load a password-file from command line or a form

6) Provide the password through network

7) many alternatives (eg Draw A Secret, Fingerprint, IP-specific, bla bla bla)

1st option: We could make things more complicated for an attacker by using obfuscation, but this is not considered a good countermeasure. A good coder can easily understand how it works if he/she can access the file. We could even export a per-user binary (or just the obfuscation part or key-part), so an attacker must have access to this user-specific file, not another distro. Again, we should find a way to change passwords, eg by recompiling or using reflection to on-the-fly change class behavior.

2nd option: We can store the password in the .properties file in an encrypted format, so it's not directly visible from an attacker (just like jasypt does). If we need a password manager we'll need a master password too which again should be stored somewhere - inside a .class file, the keystore, kernel, another file or even in memory - all have their pros and cons.
But, now users will just edit the .properties file for password change.

3rd option: type the password when running from command line e.g. java -jar /myprogram.jar -p sdflhjkiweHIUHIU8976hyd.

This doesn't require the password to be stored and will stay in memory. However, history commands and OS logs, may be your worst enemy here. To change passwords on-the-fly, you will need to implement some methods (eg listen for console inputs, RMI, sockets, REST bla bla bla), but the password will always stay in memory.

One can even temporarily decrypt it only when required -> then delete the decrypted, but always keep the encrypted password in memory. Unfortunately, the aforementioned method does not increase security against unauthorized in-memory access, because the person who achieves that, will probably have access to the algorithm, salt and any other secrets being used.

4th option: provide the password from a custom form, rather than the command line. This will circumvent the problem of logging exposure.

5th option: provide a file as a password stored previously on a another medium -> then hard delete file. This will again circumvent the problem of logging exposure, plus no typing is required that could be shoulder-surfing stolen. When a change is required, provide another file, then delete again.

6th option: again to avoid shoulder-surfing, one can implement an RMI method call, to provide the password (through an encrypted channel) from another device, eg via a mobile phone. However, you now need to protect your network channel and access to the other device.

I would choose a combination of the above methods to achieve maximum security so one would have to access the .class files, the property file, logs, network channel, shoulder surfing, man in the middle, other files bla bla bla. This can be easily implemented using a XOR operation between all sub_passwords to produce the actual password.

We can't be protected from unauthorized in-memory access though, this can only be achieved by using some access-restricted hardware (eg smartcards, HSMs, SGX), where everything is computed into them, without anyone, even the legitimate owner being able to access decryption keys or algorithms. Again, one can steal this hardware too, there are reported side-channel attacks that may help attackers in key extraction and in some cases you need to trust another party (eg with SGX you trust Intel). Of course, situation may worsen when secure-enclave cloning (de-assembling) will be possible, but I guess this will take some years to be practical.

Also, one may consider a key sharing solution where the full key is split between different servers. However, upon reconstruction, the full key can be stolen. The only way to mitigate the aforementioned issue is by secure multiparty computation.

We should always keep in mind that whatever the input method, we need to ensure we are not vulnerable from network sniffing (MITM attacks) and/or key-loggers.

Get Maven artifact version at runtime

Here's a method for getting the version from the pom.properties, falling back to getting it from the manifest

public synchronized String getVersion() {
    String version = null;

    // try to load from maven properties first
    try {
        Properties p = new Properties();
        InputStream is = getClass().getResourceAsStream("/META-INF/maven/com.my.group/my-artefact/pom.properties");
        if (is != null) {
            p.load(is);
            version = p.getProperty("version", "");
        }
    } catch (Exception e) {
        // ignore
    }

    // fallback to using Java API
    if (version == null) {
        Package aPackage = getClass().getPackage();
        if (aPackage != null) {
            version = aPackage.getImplementationVersion();
            if (version == null) {
                version = aPackage.getSpecificationVersion();
            }
        }
    }

    if (version == null) {
        // we could not compute the version so use a blank
        version = "";
    }

    return version;
} 

How can I display a list view in an Android Alert Dialog?

final CharSequence[] items = {"A", "B", "C"};

AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Make your selection");
builder.setItems(items, new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog, int item) {
        // Do something with the selection
        mDoneButton.setText(items[item]);
    }
});
AlertDialog alert = builder.create();
alert.show();