Programs & Examples On #Config

Config files configure the initial settings for some computer programs

How to create multiple output paths in Webpack config

u can do lik

var config = {
    // TODO: Add common Configuration
    module: {},
};

var x= Object.assign({}, config, {
    name: "x",
    entry: "./public/x/js/x.js",
    output: {
       path: __dirname+"/public/x/jsbuild",
       filename: "xbundle.js"
    },
});
var y= Object.assign({}, config, {
    name: "y",
    entry: "./public/y/js/FBRscript.js",
    output: {
       path: __dirname+"/public/fbr/jsbuild",
       filename: "ybundle.js"
    },
});

let list=[x,y];

for(item of list){
    module.exports =item;
}

Most Pythonic way to provide global configuration variables in config.py?

How about just using the built-in types like this:

config = {
    "mysql": {
        "user": "root",
        "pass": "secret",
        "tables": {
            "users": "tb_users"
        }
        # etc
    }
}

You'd access the values as follows:

config["mysql"]["tables"]["users"]

If you are willing to sacrifice the potential to compute expressions inside your config tree, you could use YAML and end up with a more readable config file like this:

mysql:
  - user: root
  - pass: secret
  - tables:
    - users: tb_users

and use a library like PyYAML to conventiently parse and access the config file

Where is the user's Subversion config file stored on the major operating systems?

~/.subversion/config or /etc/subversion/config

for Mac/Linux

and

%appdata%\subversion\config

for Windows

Python: How would you save a simple settings/config file?

Configuration files in python

There are several ways to do this depending on the file format required.

ConfigParser [.ini format]

I would use the standard configparser approach unless there were compelling reasons to use a different format.

Write a file like so:

# python 2.x
# from ConfigParser import SafeConfigParser
# config = SafeConfigParser()

# python 3.x
from configparser import ConfigParser
config = ConfigParser()

config.read('config.ini')
config.add_section('main')
config.set('main', 'key1', 'value1')
config.set('main', 'key2', 'value2')
config.set('main', 'key3', 'value3')

with open('config.ini', 'w') as f:
    config.write(f)

The file format is very simple with sections marked out in square brackets:

[main]
key1 = value1
key2 = value2
key3 = value3

Values can be extracted from the file like so:

# python 2.x
# from ConfigParser import SafeConfigParser
# config = SafeConfigParser()

# python 3.x
from configparser import ConfigParser
config = ConfigParser()

config.read('config.ini')

print config.get('main', 'key1') # -> "value1"
print config.get('main', 'key2') # -> "value2"
print config.get('main', 'key3') # -> "value3"

# getfloat() raises an exception if the value is not a float
a_float = config.getfloat('main', 'a_float')

# getint() and getboolean() also do this for their respective types
an_int = config.getint('main', 'an_int')

JSON [.json format]

JSON data can be very complex and has the advantage of being highly portable.

Write data to a file:

import json

config = {"key1": "value1", "key2": "value2"}

with open('config1.json', 'w') as f:
    json.dump(config, f)

Read data from a file:

import json

with open('config.json', 'r') as f:
    config = json.load(f)

#edit the data
config['key3'] = 'value3'

#write it back to the file
with open('config.json', 'w') as f:
    json.dump(config, f)

YAML

A basic YAML example is provided in this answer. More details can be found on the pyYAML website.

How do I grab an INI value within a shell script?

Just include your .ini file into bash body:

File example.ini:

DBNAME=test
DBUSER=scott
DBPASSWORD=tiger

File example.sh

#!/bin/bash
#Including .ini file
. example.ini
#Test
echo "${DBNAME}   ${DBUSER}  ${DBPASSWORD}"

How change default SVN username and password to commit changes?

In TortiseSVN settings

right-click menu >> settings >> Saved data >> Authentication data [Clear]

The side effect is that it clears out all authentication data and you have to re-enter your own username/password.

Where does git config --global get written to?

On *nixes, it's in ~/.gitconfig. Is there a corresponding file in your home?

On Windows you can type in git bash

notepad ~/.gitconfig

Why Git is not allowing me to commit even after configuration?

I had this problem even after setting the config properly. git config

My scenario was issuing git command through supervisor (in Linux). On further debugging, supervisor was not reading the git config from home folder. Hence, I had to set the environment HOME variable in the supervisor config so that it can locate the git config correctly. It's strange that supervisor was not able to locate the git config just from the username configured in supervisor's config (/etc/supervisor/conf.d).

How to make nginx to listen to server_name:port

The server_namedocs directive is used to identify virtual hosts, they're not used to set the binding.

netstat tells you that nginx listens on 0.0.0.0:80 which means that it will accept connections from any IP.

If you want to change the IP nginx binds on, you have to change the listendocs rule.
So, if you want to set nginx to bind to localhost, you'd change that to:

listen 127.0.0.1:80;

In this way, requests that are not coming from localhost are discarded (they don't even hit nginx).

Using logging in multiple modules

Best practice is, in each module, to have a logger defined like this:

import logging
logger = logging.getLogger(__name__)

near the top of the module, and then in other code in the module do e.g.

logger.debug('My message with %s', 'variable data')

If you need to subdivide logging activity inside a module, use e.g.

loggerA = logging.getLogger(__name__ + '.A')
loggerB = logging.getLogger(__name__ + '.B')

and log to loggerA and loggerB as appropriate.

In your main program or programs, do e.g.:

def main():
    "your program code"

if __name__ == '__main__':
    import logging.config
    logging.config.fileConfig('/path/to/logging.conf')
    main()

or

def main():
    import logging.config
    logging.config.fileConfig('/path/to/logging.conf')
    # your program code

if __name__ == '__main__':
    main()

See here for logging from multiple modules, and here for logging configuration for code which will be used as a library module by other code.

Update: When calling fileConfig(), you may want to specify disable_existing_loggers=False if you're using Python 2.6 or later (see the docs for more information). The default value is True for backward compatibility, which causes all existing loggers to be disabled by fileConfig() unless they or their ancestor are explicitly named in the configuration. With the value set to False, existing loggers are left alone. If using Python 2.7/Python 3.2 or later, you may wish to consider the dictConfig() API which is better than fileConfig() as it gives more control over the configuration.

Spring Boot and multiple external configuration files

Take a look at the PropertyPlaceholderConfigurer, I find it clearer to use than annotation.

e.g.

@Configuration
public class PropertiesConfiguration {


    @Bean
    public PropertyPlaceholderConfigurer properties() {
        final PropertyPlaceholderConfigurer ppc = new PropertyPlaceholderConfigurer();
//        ppc.setIgnoreUnresolvablePlaceholders(true);
        ppc.setIgnoreResourceNotFound(true);

        final List<Resource> resourceLst = new ArrayList<Resource>();

        resourceLst.add(new ClassPathResource("myapp_base.properties"));
        resourceLst.add(new FileSystemResource("/etc/myapp/overriding.propertie"));
        resourceLst.add(new ClassPathResource("myapp_test.properties"));
        resourceLst.add(new ClassPathResource("myapp_developer_overrides.properties")); // for Developer debugging.

        ppc.setLocations(resourceLst.toArray(new Resource[]{}));

        return ppc;
    }

How to check if ZooKeeper is running or up from command prompt?

echo stat | nc localhost 2181 | grep Mode
echo srvr | nc localhost 2181 | grep Mode #(From 3.3.0 onwards)

Above will work in whichever modes Zookeeper is running (standalone or embedded).

Another way

If zookeeper is running in standalone mode, its a JVM process. so -

jps | grep Quorum

will display list of jvm processes; something like this for zookeeper with process ID

HQuorumPeer

How to get the values of a ConfigurationSection of type NameValueSectionHandler

Here's a good post that shows how to do it.

If you want to read the values from a file other than the app.config, you need to load it into the ConfigurationManager.

Try this method: ConfigurationManager.OpenMappedExeConfiguration()

There's an example of how to use it in the MSDN article.

How to use ConfigurationManager

I found some answers, but I don't know if it is the right way.This is my solution for now. Fortunatelly it didn´t broke my design mode.

    `
    /// <summary>
    /// set config, if key is not in file, create
    /// </summary>
    /// <param name="key">Nome do parâmetro</param>
    /// <param name="value">Valor do parâmetro</param>
    public static void SetConfig(string key, string value)
    {
        var configFile = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
        var settings = configFile.AppSettings.Settings;
        if (settings[key] == null)
        {
            settings.Add(key, value);
        }
        else
        {
            settings[key].Value = value;
        }
        configFile.Save(ConfigurationSaveMode.Modified);
        ConfigurationManager.RefreshSection(configFile.AppSettings.SectionInformation.Name);
    }

    /// <summary>
    /// Get key value, if not found, return null
    /// </summary>
    /// <param name="key"></param>
    /// <returns>null if key is not found, else string with value</returns>
    public static string GetConfig(string key)
    {
        return ConfigurationManager.AppSettings[key];
    }`

Is it possible to get the current spark context settings in PySpark?

For Spark 2+ you can also use when using scala

spark.conf.getAll; //spark as spark session 

Get environment value in controller

You can use with this format (tested on Laravel 5.5). In my case I used it for gettting the data of database connections and use on Controller:

$User = env('DB_USERNAMEchild','');
$Pass = env('DB_PASSWORDchild','');

The second parameter can be null, or set any default in case of DB_USERNAMEchild is null.

Your .env file can be the same:

DB_HOST=localhost
DB_DATABASE=FATHERBD
DB_USERNAME=root
DB_PASSWORD=password

DB_DATABASEchild=ZTEST
DB_USERNAMEchild=root
DB_PASSWORDchild=passwordofchild

How to install .MSI using PowerShell

#Variables
$computername = Get-Content 'M:\Applications\Powershell\comp list\Test.txt'
$sourcefile = "\\server\Apps\LanSchool 7.7\Windows\Student.msi"
#This section will install the software 
foreach ($computer in $computername) 
{
    $destinationFolder = "\\$computer\C$\download\LanSchool"
    #This section will copy the $sourcefile to the $destinationfolder. If the Folder does not exist it will create it.
    if (!(Test-Path -path $destinationFolder))
    {
        New-Item $destinationFolder -Type Directory
    }
    Copy-Item -Path $sourcefile -Destination $destinationFolder
    Invoke-Command -ComputerName $computer -ScriptBlock { & cmd /c "msiexec.exe /i c:\download\LanSchool\Student.msi" /qn ADVANCED_OPTIONS=1 CHANNEL=100}
}

I've searched all over for this myself and came up with zilch but have finally cobbled this working script together. It's working great! Thought I'd post here hopefully someone else can benefit. It pulls in a list of computers, copies the files down to the local machines and runs it. :) party on!

Can I add and remove elements of enumeration at runtime in Java

Behind the curtain, enums are POJOs with a private constructor and a bunch of public static final values of the enum's type (see here for an example). In fact, up until Java5, it was considered best-practice to build your own enumeration this way, and Java5 introduced the enum keyword as a shorthand. See the source for Enum<T> to learn more.

So it should be no problem to write your own 'TypeSafeEnum' with a public static final array of constants, that are read by the constructor or passed to it.

Also, do yourself a favor and override equals, hashCode and toString, and if possible create a values method

The question is how to use such a dynamic enumeration... you can't read the value "PI=3.14" from a file to create enum MathConstants and then go ahead and use MathConstants.PI wherever you want...

Boolean vs boolean in Java

You can use the Boolean constants - Boolean.TRUE and Boolean.FALSE instead of 0 and 1. You can create your variable as of type boolean if primitive is what you are after. This way you won't have to create new Boolean objects.

What is the easiest way to remove all packages installed by pip?

I wanted to elevate this answer out of a comment section because it's one of the most elegant solutions in the thread. Full credit for this answer goes to @joeb.

pip uninstall -y -r <(pip freeze)

This worked great for me for the use case of clearing my user packages folder outside the context of a virtualenv which many of the above answers don't handle.

Edit: Anyone know how to make this command work in a Makefile?

Bonus: A bash alias

I add this to my bash profile for convenience:

alias pipuninstallall="pip uninstall -y -r <(pip freeze)"

Then run:

pipuninstallall

Alternative for pipenv

If you happen to be using pipenv you can just run:

pipenv uninstall --all

Win32Exception (0x80004005): The wait operation timed out

We encountered this error after an upgrade from 2008 to 2014 SQL Server where our some of our previous connection strings for local development had a Data Source=./ like this

        <add name="MyLocalDatabase" connectionString="Data Source=./;Initial Catalog=SomeCatalog;Integrated Security=SSPI;Application Name=MyApplication;"/>

Changing that from ./ to either (local) or localhost fixed the problem.

<add name="MyLocalDatabase" connectionString="Data Source=(local);Initial Catalog=SomeCatalog;Integrated Security=SSPI;Application Name=MyApplication;"/>

add maven repository to build.gradle

You will need to define the repository outside of buildscript. The buildscript configuration block only sets up the repositories and dependencies for the classpath of your build script but not your application.

How do I return to an older version of our code in Subversion?

Most of the previous answers have been using a reverse merge, and that's usually the right answer. However, there's one situation (which just happened to me) where it's not.

I accidentally changed a file with Unix line endings to DOS line endings when making a small change, and committed it. This is easily undone, either by changing the line endings and committing again, or by a reverse merge, but it has the effect of making svn blame list my edit as the source of every line of the file. (Interestingly, TortoiseSVN on Windows doesn't get affected by this; only the command line svn blame.)

If you want to maintain the history as reported by svn blame, I think you need to do the following:

  • Delete the file and commit.
  • In the repository, copy the previous good copy of the file into the head, and commit.
  • Restore any edits that you do want to keep.

The deletion is a little scary, but remember you always have the file saved in the repository, so restoring it is not a big deal. Here's some code to illustrate the steps. Assume that xxx is the revision number of the last good copy.

svn rm svn+ssh://path/to/file
svn copy svn+ssh://path/to/file@xxx svn+ssh://path/to -m"Restore good copy"
svn update
<restore the edits>
svn commit -m"Restore edits"

Note that for a copy in the repository, the destination needs to be a directory, not a filename.

How do you create a foreign key relationship in a SQL Server CE (Compact Edition) Database?

create table employee
(
   empid int,
   empname varchar(40),
   designation varchar(30),
   hiredate datetime, 
   Bsalary int,
   depno constraint emp_m foreign key references department(depno)
)

We should have an primary key to create foreign key or relationship between two or more table .

How to reset a form using jQuery with .reset() method

According to this post here, jQuery has no reset() method; but native JavaScript does. So, convert the jQuery element to a JavaScript object by either using :

$("#formId")[0].reset()
// or
$("#formId").get(0).reset()

DataGrid get selected rows' column values

I used a similar way to solve this problem using the animescm sugestion, indeed we can obtain the specific cells values from a group of selected cells using an auxiliar list:

private void dataGridCase_SelectionChanged(object sender, SelectedCellsChangedEventArgs e)
    {
        foreach (var item in e.AddedCells)
        {
            var col = item.Column as DataGridColumn;
            var fc = col.GetCellContent(item.Item);
            lstTxns.Items.Add((fc as TextBlock).Text);
        }
    }

Use of ~ (tilde) in R programming Language

R defines a ~ (tilde) operator for use in formulas. Formulas have all sorts of uses, but perhaps the most common is for regression:

library(datasets)
lm( myFormula, data=iris)

help("~") or help("formula") will teach you more.

@Spacedman has covered the basics. Let's discuss how it works.

First, being an operator, note that it is essentially a shortcut to a function (with two arguments):

> `~`(lhs,rhs)
lhs ~ rhs
> lhs ~ rhs
lhs ~ rhs

That can be helpful to know for use in e.g. apply family commands.

Second, you can manipulate the formula as text:

oldform <- as.character(myFormula) # Get components
myFormula <- as.formula( paste( oldform[2], "Sepal.Length", sep="~" ) )

Third, you can manipulate it as a list:

myFormula[[2]]
myFormula[[3]]

Finally, there are some helpful tricks with formulae (see help("formula") for more):

myFormula <- Species ~ . 

For example, the version above is the same as the original version, since the dot means "all variables not yet used." This looks at the data.frame you use in your eventual model call, sees which variables exist in the data.frame but aren't explicitly mentioned in your formula, and replaces the dot with those missing variables.

Purpose of __repr__ method?

Implement repr for every class you implement. There should be no excuse. Implement str for classes which you think readability is more important of non-ambiguity.

Refer this link: https://www.pythoncentral.io/what-is-the-difference-between-str-and-repr-in-python/

Quickest way to convert a base 10 number to any base in .NET?

Very late to the party on this one, but I wrote the following helper class recently for a project at work. It was designed to convert short strings into numbers and back again (a simplistic perfect hash function), however it will also perform number conversion between arbitrary bases. The Base10ToString method implementation answers the question that was originally posted.

The shouldSupportRoundTripping flag passed to the class constructor is needed to prevent the loss of leading digits from the number string during conversion to base-10 and back again (crucial, given my requirements!). Most of the time the loss of leading 0s from the number string probably won't be an issue.

Anyway, here's the code:

using System;
using System.Collections.Generic;
using System.Linq;

namespace StackOverflow
{
    /// <summary>
    /// Contains methods used to convert numbers between base-10 and another numbering system.
    /// </summary>
    /// <remarks>
    /// <para>
    /// This conversion class makes use of a set of characters that represent the digits used by the target
    /// numbering system. For example, binary would use the digits 0 and 1, whereas hex would use the digits
    /// 0 through 9 plus A through F. The digits do not have to be numerals.
    /// </para>
    /// <para>
    /// The first digit in the sequence has special significance. If the number passed to the
    /// <see cref="StringToBase10"/> method has leading digits that match the first digit, then those leading
    /// digits will effectively be 'lost' during conversion. Much of the time this won't matter. For example,
    /// "0F" hex will be converted to 15 decimal, but when converted back to hex it will become simply "F",
    /// losing the leading "0". However, if the set of digits was A through Z, and the number "ABC" was
    /// converted to base-10 and back again, then the leading "A" would be lost. The <see cref="System.Boolean"/>
    /// flag passed to the constructor allows 'round-tripping' behaviour to be supported, which will prevent
    /// leading digits from being lost during conversion.
    /// </para>
    /// <para>
    /// Note that numeric overflow is probable when using longer strings and larger digit sets.
    /// </para>
    /// </remarks>
    public class Base10Converter
    {
        const char NullDigit = '\0';

        public Base10Converter(string digits, bool shouldSupportRoundTripping = false)
            : this(digits.ToCharArray(), shouldSupportRoundTripping)
        {
        }

        public Base10Converter(IEnumerable<char> digits, bool shouldSupportRoundTripping = false)
        {
            if (digits == null)
            {
                throw new ArgumentNullException("digits");
            }

            if (digits.Count() == 0)
            {
                throw new ArgumentException(
                    message: "The sequence is empty.",
                    paramName: "digits"
                    );
            }

            if (!digits.Distinct().SequenceEqual(digits))
            {
                throw new ArgumentException(
                    message: "There are duplicate characters in the sequence.",
                    paramName: "digits"
                    );
            }

            if (shouldSupportRoundTripping)
            {
                digits = (new[] { NullDigit }).Concat(digits);
            }

            _digitToIndexMap =
                digits
                .Select((digit, index) => new { digit, index })
                .ToDictionary(keySelector: x => x.digit, elementSelector: x => x.index);

            _radix = _digitToIndexMap.Count;

            _indexToDigitMap =
                _digitToIndexMap
                .ToDictionary(keySelector: x => x.Value, elementSelector: x => x.Key);
        }

        readonly Dictionary<char, int> _digitToIndexMap;
        readonly Dictionary<int, char> _indexToDigitMap;
        readonly int _radix;

        public long StringToBase10(string number)
        {
            Func<char, int, long> selector =
                (c, i) =>
                {
                    int power = number.Length - i - 1;

                    int digitIndex;
                    if (!_digitToIndexMap.TryGetValue(c, out digitIndex))
                    {
                        throw new ArgumentException(
                            message: String.Format("Number contains an invalid digit '{0}' at position {1}.", c, i),
                            paramName: "number"
                            );
                    }

                    return Convert.ToInt64(digitIndex * Math.Pow(_radix, power));
                };

            return number.Select(selector).Sum();
        }

        public string Base10ToString(long number)
        {
            if (number < 0)
            {
                throw new ArgumentOutOfRangeException(
                    message: "Value cannot be negative.",
                    paramName: "number"
                    );
            }

            string text = string.Empty;

            long remainder;
            do
            {
                number = Math.DivRem(number, _radix, out remainder);

                char digit;
                if (!_indexToDigitMap.TryGetValue((int) remainder, out digit) || digit == NullDigit)
                {
                    throw new ArgumentException(
                        message: "Value cannot be converted given the set of digits used by this converter.",
                        paramName: "number"
                        );
                }

                text = digit + text;
            }
            while (number > 0);

            return text;
        }
    }
}

This can also be subclassed to derive custom number converters:

namespace StackOverflow
{
    public sealed class BinaryNumberConverter : Base10Converter
    {
        public BinaryNumberConverter()
            : base(digits: "01", shouldSupportRoundTripping: false)
        {
        }
    }

    public sealed class HexNumberConverter : Base10Converter
    {
        public HexNumberConverter()
            : base(digits: "0123456789ABCDEF", shouldSupportRoundTripping: false)
        {
        }
    }
}

And the code would be used like this:

using System.Diagnostics;

namespace StackOverflow
{
    class Program
    {
        static void Main(string[] args)
        {
            {
                var converter = new Base10Converter(
                    digits: "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz",
                    shouldSupportRoundTripping: true
                    );

                long number = converter.StringToBase10("Atoz");
                string text = converter.Base10ToString(number);
                Debug.Assert(text == "Atoz");
            }

            {
                var converter = new HexNumberConverter();

                string text = converter.Base10ToString(255);
                long number = converter.StringToBase10(text);
                Debug.Assert(number == 255);
            }
        }
    }
}

Skip first entry in for loop in python?

An alternative method:

for idx, car in enumerate(cars):
    # Skip first line.
    if not idx:
        continue
    # Skip last line.
    if idx + 1 == len(cars):
        continue
    # Real code here.
    print car

MySQL: ALTER TABLE if column not exists

$sql="SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'Your_Table_Name' AND COLUMN_NAME = 'Your_New_Column_Name'";
$RESULT = mysqli_query($conn,$sql);

The abobe query return 0 if the column is not present in your table then you need to run alter query like below

if($RESULT){
    $sqll="ALTER TABLE Your_table_Name ADD COLUMN Your_New_Column_Name varchar(20) NOT NULL DEFAULT 0";
}

How can I quantify difference between two images?

I think you could simply compute the euclidean distance (i.e. sqrt(sum of squares of differences, pixel by pixel)) between the luminance of the two images, and consider them equal if this falls under some empirical threshold. And you would better do it wrapping a C function.

Kendo grid date column not formatting

The option I use is as follows:

columns.Bound(p => p.OrderDate).Format("{0:d}").ClientTemplate("#=formatDate(OrderDate)#");

function formatDate(OrderDate) {
    var formatedOrderDate = kendo.format("{0:d}", OrderDate);

    return formatedOrderDate;
}

PHP: HTTP or HTTPS?

If your request is sent by HTTPS you will have an extra server variable named 'HTTPS'

if (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] != 'off') { //HTTPS } 

How to remove all characters after a specific character in python?

import re
test = "This is a test...we should not be able to see this"
res = re.sub(r'\.\.\..*',"",test)
print(res)

Output: "This is a test"

execJs: 'Could not find a JavaScript runtime' but execjs AND therubyracer are in Gemfile

add in your gemfile which is in the folder you have created: gem 'execjs' gem 'therubyracer'

Intellij Cannot resolve symbol on import

File -> Invalidate Caches/Restart or rebuilding the project did not work wor me.

What worked for my Gradle project was to "Refresh all Gradle projects" from the Gradle tab on top-right corner of IntelliJ v2017, using the yellow marked button shown below:

enter image description here

How to prepare a Unity project for git?

On the Unity Editor open your project and:

  1. Enable External option in Unity ? Preferences ? Packages ? Repository (only if Unity ver < 4.5)
  2. Switch to Visible Meta Files in Edit ? Project Settings ? Editor ? Version Control Mode
  3. Switch to Force Text in Edit ? Project Settings ? Editor ? Asset Serialization Mode
  4. Save Scene and Project from File menu.
  5. Quit Unity and then you can delete the Library and Temp directory in the project directory. You can delete everything but keep the Assets and ProjectSettings directory.

If you already created your empty git repo on-line (eg. github.com) now it's time to upload your code. Open a command prompt and follow the next steps:

cd to/your/unity/project/folder

git init

git add *

git commit -m "First commit"

git remote add origin [email protected]:username/project.git

git push -u origin master

You should now open your Unity project while holding down the Option or the Left Alt key. This will force Unity to recreate the Library directory (this step might not be necessary since I've seen Unity recreating the Library directory even if you don't hold down any key).

Finally have git ignore the Library and Temp directories so that they won’t be pushed to the server. Add them to the .gitignore file and push the ignore to the server. Remember that you'll only commit the Assets and ProjectSettings directories.

And here's my own .gitignore recipe for my Unity projects:

# =============== #
# Unity generated #
# =============== #
Temp/
Obj/
UnityGenerated/
Library/
Assets/AssetStoreTools*

# ===================================== #
# Visual Studio / MonoDevelop generated #
# ===================================== #
ExportedObj/
*.svd
*.userprefs
*.csproj
*.pidb
*.suo
*.sln
*.user
*.unityproj
*.booproj

# ============ #
# OS generated #
# ============ #
.DS_Store
.DS_Store?
._*
.Spotlight-V100
.Trashes
Icon?
ehthumbs.db
Thumbs.db

What's the difference between IFrame and Frame?

iframes are used a lot to include complete pages. When those pages are hosted on another domain you get problems with cross side scripting and stuff. There are ways to fix this.

Frames were used to divide your page into multiple parts (for example, a navigation menu on the left). Using them is no longer recommended.

How do we determine the number of days for a given month in python

Just for the sake of academic interest, I did it this way...

(dt.replace(month = dt.month % 12 +1, day = 1)-timedelta(days=1)).day

What is the exact meaning of Git Bash?

I think the question asker is (was) thinking that git bash is a command like git init or git checkout. Git bash is not a command, it is an interface. I will also assume the asker is not a linux user because bash is very popular the unix/linux world. The name "bash" is an acronym for "Bourne Again SHell". Bash is a text-only command interface that has features which allow automated scripts to be run. A good analogy would be to compare bash to the new PowerShell interface in Windows7/8. A poor analogy (but one likely to be more readily understood by more people) is the combination of the command prompt and .BAT (batch) command files from the days of DOS and early versions of Windows.

REFERENCES:

Subtract two dates in SQL and get days of the result

SELECT DATEDIFF(day,'2014-06-05','2014-08-05') AS DiffDate

diffdate is column name.

result:

DiffDate

23

Node Express sending image files as API response

a proper solution with streams and error handling is below:

const fs = require('fs')
const stream = require('stream')

app.get('/report/:chart_id/:user_id',(req, res) => {
  const r = fs.createReadStream('path to file') // or any other way to get a readable stream
  const ps = new stream.PassThrough() // <---- this makes a trick with stream error handling
  stream.pipeline(
   r,
   ps, // <---- this makes a trick with stream error handling
   (err) => {
    if (err) {
      console.log(err) // No such file or any other kind of error
      return res.sendStatus(400); 
    }
  })
  ps.pipe(res) // <---- this makes a trick with stream error handling
})

with Node older then 10 you will need to use pump instead of pipeline.

How to access /storage/emulated/0/

As Hiren stated, you'll need a file explorer to see your directory. If you're rooted I highly suggest root explorer, otherwise ES File Explorer is a good choice.

How to get a time zone from a location using latitude and longitude coordinates?

_x000D_
_x000D_
  function jsonpRequest(url, data)_x000D_
{_x000D_
    let params = "";_x000D_
    for (let key in data)_x000D_
    {_x000D_
        if (data.hasOwnProperty(key))_x000D_
        {_x000D_
            if (params.length == 0)_x000D_
            {_x000D_
                params += "?";_x000D_
            }_x000D_
            else_x000D_
            {_x000D_
                params += "&";_x000D_
            }_x000D_
            let encodedKey = encodeURIComponent(key);_x000D_
            let encodedValue = encodeURIComponent(data[key]);_x000D_
            params += encodedKey + "=" + encodedValue;_x000D_
         }_x000D_
    }_x000D_
    let script = document.createElement('script');_x000D_
    script.src = url + params;_x000D_
    document.body.appendChild(script);_x000D_
}_x000D_
_x000D_
function getLocation() {_x000D_
  if (navigator.geolocation) {_x000D_
    navigator.geolocation.getCurrentPosition(showPosition);_x000D_
  } else {_x000D_
    x.innerHTML = "Geolocation is not supported by this browser.";_x000D_
  }_x000D_
}_x000D_
let lat_ini=[]; let lon_ini=[];_x000D_
function showPosition(position) {_x000D_
  lat_ini= position.coords.latitude;_x000D_
  lon_ini= position.coords.longitude;_x000D_
}_x000D_
////delay time between lines_x000D_
function sleep(ms) {_x000D_
  return new Promise(resolve => setTimeout(resolve, ms));_x000D_
}_x000D_
///////_x000D_
function getGMT()_x000D_
{_x000D_
  getfinalGMT()_x000D_
  getLocation()_x000D_
  async function sample() {_x000D_
    await sleep(2000);_x000D_
let lat_str=lat_ini.toString();_x000D_
let lng_str=" "+lon_ini.toString();_x000D_
_x000D_
  let url = "https://api.opencagedata.com/geocode/v1/json";_x000D_
  let data = {_x000D_
    callback: "displayGMT",_x000D_
    q: lat_str + lng_str,_x000D_
    key: "fac4471073a347019196c1291e6a97d7"_x000D_
  }_x000D_
  jsonpRequest(url, data)_x000D_
}_x000D_
 sample();_x000D_
 }_x000D_
let your_GMT=[];_x000D_
function displayGMT(data)_x000D_
{_x000D_
your_GMT=(Number(data.results[0].annotations.timezone.offset_string))_x000D_
console.log(your_GMT)_x000D_
}_x000D_
/////_x000D_
function getfinalGMT()_x000D_
{_x000D_
let lat=document.getElementById("lat_id").value; let lng=document.getElementById("lng_id").value;_x000D_
let lat_str=lat.toString();_x000D_
let lng_str=" "+lng.toString();_x000D_
_x000D_
  let url = "https://api.opencagedata.com/geocode/v1/json";_x000D_
  let data = {_x000D_
    callback: "displayfinalGMT",_x000D_
    q: lat + lng_str,_x000D_
    key: "fac4471073a347019196c1291e6a97d7"_x000D_
  }_x000D_
  jsonpRequest(url, data)_x000D_
 }_x000D_
let final_GMT=[];_x000D_
function displayfinalGMT(data)_x000D_
{_x000D_
final_GMT=(Number(data.results[0].annotations.timezone.offset_string))_x000D_
console.log(final_GMT)_x000D_
}_x000D_
/////clock_x000D_
_x000D_
_x000D_
const hourHand = document.querySelector('[data-hour-hand]')_x000D_
const minuteHand = document.querySelector('[data-minute-hand]')_x000D_
const secondHand = document.querySelector('[data-second-hand]')_x000D_
  let dif_overall=[];_x000D_
function setClock() {_x000D_
   let gmt_diff=Number(your_GMT-final_GMT)/100_x000D_
   if (gmt_diff>12){_x000D_
      dif_overall=gmt_diff-12_x000D_
   }_x000D_
   else{_x000D_
     dif_overall=gmt_diff_x000D_
   }_x000D_
    console.log(dif_overall)_x000D_
  const currentDate = new Date()_x000D_
  const secondsRatio = currentDate.getSeconds() / 60_x000D_
  const minutesRatio = (secondsRatio + currentDate.getMinutes()) / 60_x000D_
  const hoursRatio = (minutesRatio + currentDate.getHours() - dif_overall ) / 12_x000D_
  setRotation(secondHand, secondsRatio)_x000D_
  setRotation(minuteHand, minutesRatio)_x000D_
  setRotation(hourHand, hoursRatio)_x000D_
}_x000D_
_x000D_
function setRotation(element, rotationRatio) {_x000D_
  element.style.setProperty('--rotation', rotationRatio * 360)_x000D_
}_x000D_
function activate_clock(){_x000D_
setClock()_x000D_
setInterval(setClock, 1000)_x000D_
}
_x000D_
*, *::after, *::before {_x000D_
  box-sizing: border-box;_x000D_
}_x000D_
_x000D_
body {_x000D_
  background: linear-gradient(to right, hsl(200, 100%, 50%), hsl(175, 100%, 50%));_x000D_
  display: flex;_x000D_
  justify-content: center;_x000D_
  align-items: center;_x000D_
  min-height: 100vh;_x000D_
  overflow: hidden;_x000D_
}_x000D_
_x000D_
.clock {_x000D_
  width: 200px;_x000D_
  height: 200px;_x000D_
  background-color: rgba(255, 255, 255, .8);_x000D_
  border-radius: 50%;_x000D_
  border: 2px solid black;_x000D_
  position: relative;_x000D_
}_x000D_
_x000D_
.clock .number {_x000D_
  --rotation: 0;_x000D_
  position: absolute;_x000D_
  width: 100%;_x000D_
  height: 100%;_x000D_
  text-align: center;_x000D_
  transform: rotate(var(--rotation));_x000D_
  font-size: 1.5rem;_x000D_
}_x000D_
_x000D_
.clock .number1 { --rotation: 30deg; }_x000D_
.clock .number2 { --rotation: 60deg; }_x000D_
.clock .number3 { --rotation: 90deg; }_x000D_
.clock .number4 { --rotation: 120deg; }_x000D_
.clock .number5 { --rotation: 150deg; }_x000D_
.clock .number6 { --rotation: 180deg; }_x000D_
.clock .number7 { --rotation: 210deg; }_x000D_
.clock .number8 { --rotation: 240deg; }_x000D_
.clock .number9 { --rotation: 270deg; }_x000D_
.clock .number10 { --rotation: 300deg; }_x000D_
.clock .number11 { --rotation: 330deg; }_x000D_
_x000D_
.clock .hand {_x000D_
  --rotation: 0;_x000D_
  position: absolute;_x000D_
  bottom: 50%;_x000D_
  left: 50%;_x000D_
  border: 1px solid white;_x000D_
  border-top-left-radius: 10px;_x000D_
  border-top-right-radius: 10px;_x000D_
  transform-origin: bottom;_x000D_
  z-index: 10;_x000D_
  transform: translateX(-50%) rotate(calc(var(--rotation) * 1deg));_x000D_
}_x000D_
_x000D_
.clock::after {_x000D_
  content: '';_x000D_
  position: absolute;_x000D_
  background-color: black;_x000D_
  z-index: 11;_x000D_
  width: 15px;_x000D_
  height: 15px;_x000D_
  top: 50%;_x000D_
  left: 50%;_x000D_
  transform: translate(-50%, -50%);_x000D_
  border-radius: 50%;_x000D_
}_x000D_
_x000D_
.clock .hand.second {_x000D_
  width: 3px;_x000D_
  height: 45%;_x000D_
  background-color: red;_x000D_
}_x000D_
_x000D_
.clock .hand.minute {_x000D_
  width: 7px;_x000D_
  height: 40%;_x000D_
  background-color: black;_x000D_
}_x000D_
_x000D_
.clock .hand.hour {_x000D_
  width: 10px;_x000D_
  height: 35%;_x000D_
  background-color: black;_x000D_
}_x000D_
_x000D_
_x000D_
_x000D_
_x000D_
_x000D_
_x000D_
_x000D_
_x000D_
_x000D_
_x000D_
_x000D_
_x000D_
_x000D_
_x000D_
/* Background Styles Only */_x000D_
_x000D_
@import url('https://fonts.googleapis.com/css?family=Raleway');_x000D_
_x000D_
* {_x000D_
    font-family: Raleway;_x000D_
}_x000D_
_x000D_
.side-links {_x000D_
  position: absolute;_x000D_
  top: 15px;_x000D_
  right: 15px;_x000D_
}_x000D_
_x000D_
.side-link {_x000D_
  display: flex;_x000D_
  align-items: center;_x000D_
  justify-content: center;_x000D_
  text-decoration: none;_x000D_
  margin-bottom: 10px;_x000D_
  color: white;_x000D_
  width: 180px;_x000D_
  padding: 10px 0;_x000D_
  border-radius: 10px;_x000D_
}_x000D_
_x000D_
.side-link-youtube {_x000D_
  background-color: red;_x000D_
}_x000D_
_x000D_
.side-link-twitter {_x000D_
  background-color: #1DA1F2;_x000D_
}_x000D_
_x000D_
.side-link-github {_x000D_
  background-color: #6e5494;_x000D_
}_x000D_
_x000D_
.side-link-text {_x000D_
  margin-left: 10px;_x000D_
  font-size: 18px;_x000D_
}_x000D_
_x000D_
.side-link-icon {_x000D_
  color: white;_x000D_
  font-size: 30px;_x000D_
}
_x000D_
   <input type="text" id="lat_id" placeholder="lat"><br><br>_x000D_
  <input type="text" id="lng_id" placeholder="lng"><br><br>_x000D_
<button class="text" onClick="getLocation()">Location</button>_x000D_
<button class="text" onClick="getGMT()"> GMT</button>_x000D_
<button class="text" onClick="activate_clock()"> Activate</button>_x000D_
<div class="clock">_x000D_
  <div class="hand hour" data-hour-hand></div>_x000D_
  <div class="hand minute" data-minute-hand></div>_x000D_
  <div class="hand second" data-second-hand></div>_x000D_
  <div class="number number1">1</div>_x000D_
  <div class="number number2">2</div>_x000D_
  <div class="number number3">3</div>_x000D_
  <div class="number number4">4</div>_x000D_
  <div class="number number5">5</div>_x000D_
  <div class="number number6">6</div>_x000D_
  <div class="number number7">7</div>_x000D_
  <div class="number number8">8</div>_x000D_
  <div class="number number9">9</div>_x000D_
  <div class="number number10">10</div>_x000D_
  <div class="number number11">11</div>_x000D_
  <div class="number number12">12</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How do I get git to default to ssh and not https for new repositories

  • GitHub

    git config --global url.ssh://[email protected]/.insteadOf https://github.com/
    
  • BitBucket

    git config --global url.ssh://[email protected]/.insteadOf https://bitbucket.org/
    

That tells git to always use SSH instead of HTTPS when connecting to GitHub/BitBucket, so you'll authenticate by certificate by default, instead of being prompted for a password.

How can I convert a hex string to a byte array?

Here's a nice fun LINQ example.

public static byte[] StringToByteArray(string hex) {
    return Enumerable.Range(0, hex.Length)
                     .Where(x => x % 2 == 0)
                     .Select(x => Convert.ToByte(hex.Substring(x, 2), 16))
                     .ToArray();
}

Set element width or height in Standards Mode

The style property lets you specify values for CSS properties.

The CSS width property takes a length as its value.

Lengths require units. In quirks mode, browsers tend to assume pixels if provided with an integer instead of a length. Specify units.

e1.style.width = "400px";

how to delete a specific row in codeigniter?

My controller

public function delete_category()   //Created a controller class //
    {      
         $this->load->model('Managecat'); //Load model Managecat here 
         $id=$this->input->get('id');     //  get the requested in a variable
         $sql_del=$this->Managecat->deleteRecord($id); //send the parameter $id in Managecat  there I have created a function name deleteRecord

         if($sql_del){

               $data['success'] = "Category Have been deleted Successfully!!";  //success message goes here 

         }

    }

My Model

public function deleteRecord($id) {

    $this->db->where('cat_id', $id);
    $del=$this->db->delete('category');   
    return $del;

}

Vue v-on:click does not work on component

It's the @Neps' answer but with details.


Note: @Saurabh's answer is more suitable if you don't want to modify your component or don't have access to it.


Why can't @click just work?

Components are complicated. One component can be a small fancy button wrapper, and another one can be an entire table with bunch of logic inside. Vue doesn't know what exactly you expect when bind v-model or use v-on so all of that should be processed by component's creator.

How to handle click event

According to Vue docs, $emit passes events to parent. Example from docs:

Main file

<blog-post
  @enlarge-text="onEnlargeText"
/>

Component

<button @click="$emit('enlarge-text')">
  Enlarge text
</button>

(@ is the v-on shorthand)

Component handles native click event and emits parent's @enlarge-text="..."

enlarge-text can be replaced with click to make it look like we're handling a native click event:

<blog-post
  @click="onEnlargeText"
></blog-post>
<button @click="$emit('click')">
  Enlarge text
</button>

But that's not all. $emit allows to pass a specific value with an event. In the case of native click, the value is MouseEvent (JS event that has nothing to do with Vue).

Vue stores that event in a $event variable. So, it'd the best to emit $event with an event to create the impression of native event usage:

<button v-on:click="$emit('click', $event)">
  Enlarge text
</button>

Android Studio Run/Debug configuration error: Module not specified

I struggled with this because I'm developing a library, and every now and then want to run it as an application.

From app/build.gradle, check that you have apply plugin: 'com.android.application' instead of apply plugin: 'com.android.library'.

You should also have this in app/build.gradle:

defaultConfig { applicationId "com.your_company.your_application" ... }

Finally run Gradle sync.

How to check if an array element exists?

You can use either the language construct isset, or the function array_key_exists.

isset should be a bit faster (as it's not a function), but will return false if the element exists and has the value NULL.


For example, considering this array :

$a = array(
    123 => 'glop', 
    456 => null, 
);

And those three tests, relying on isset :

var_dump(isset($a[123]));
var_dump(isset($a[456]));
var_dump(isset($a[789]));

The first one will get you (the element exists, and is not null) :

boolean true

While the second one will get you (the element exists, but is null) :

boolean false

And the last one will get you (the element doesn't exist) :

boolean false


On the other hand, using array_key_exists like this :

var_dump(array_key_exists(123, $a));
var_dump(array_key_exists(456, $a));
var_dump(array_key_exists(789, $a));

You'd get those outputs :

boolean true
boolean true
boolean false

Because, in the two first cases, the element exists -- even if it's null in the second case. And, of course, in the third case, it doesn't exist.


For situations such as yours, I generally use isset, considering I'm never in the second case... But choosing which one to use is now up to you ;-)

For instance, your code could become something like this :

if (!isset(self::$instances[$instanceKey])) {
    $instances[$instanceKey] = $theInstance;
}

comparing 2 strings alphabetically for sorting purposes

"a".localeCompare("b") should actually return -1 since a sorts before b

http://www.w3schools.com/jsref/jsref_localecompare.asp

how to read all files inside particular folder

If you are looking to copy all the text files in one folder to merge and copy to another folder, you can do this to achieve that:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace HowToCopyTextFiles
{
  class Program
  {
    static void Main(string[] args)
    {
      string mydocpath=Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);     
      StringBuilder sb = new StringBuilder();
      foreach (string txtName in Directory.GetFiles(@"D:\Links","*.txt"))
      {
        using (StreamReader sr = new StreamReader(txtName))
        {
          sb.AppendLine(txtName.ToString());
          sb.AppendLine("= = = = = =");
          sb.Append(sr.ReadToEnd());
          sb.AppendLine();
          sb.AppendLine();   
        }
      }
      using (StreamWriter outfile=new StreamWriter(mydocpath + @"\AllTxtFiles.txt"))
      {    
        outfile.Write(sb.ToString());
      }   
    }
  }
}

How I can check if an object is null in ruby on rails 2?

You can check if an object is nil (null) by calling present? or blank? .

@object.present?

this will return false if the project is an empty string or nil .

or you can use

@object.blank?

this is the same as present? with a bang and you can use it if you don't like 'unless'. this will return true for an empty string or nil .

PHP Function with Optional Parameters

If you are commonly just passing in the 8th value, you can reorder your parameters so it is first. You only need to specify parameters up until the last one you want to set.

If you are using different values, you have 2 options.

One would be to create a set of wrapper functions that take different parameters and set the defaults on the others. This is useful if you only use a few combinations, but can get very messy quickly.

The other option is to pass an array where the keys are the names of the parameters. You can then just check if there is a value in the array with a key, and if not use the default. But again, this can get messy and add a lot of extra code if you have a lot of parameters.

Ranges of floating point datatype in C?

As dasblinkenlight already answered, the numbers come from the way that floating point numbers are represented in IEEE-754, and Andreas has a nice breakdown of the maths.

However - be careful that the precision of floating point numbers isn't exactly 6 or 15 significant decimal digits as the table suggests, since the precision of IEEE-754 numbers depends on the number of significant binary digits.

  • float has 24 significant binary digits - which depending on the number represented translates to 6-8 decimal digits of precision.

  • double has 53 significant binary digits, which is approximately 15 decimal digits.

Another answer of mine has further explanation if you're interested.

Is it possible to focus on a <div> using JavaScript focus() function?

document.getElementById('tries').scrollIntoView() works. This works better than window.location.hash when you have fixed positioning.

How can I get the intersection, union, and subset of arrays in Ruby?

If Multiset extends from the Array class

x = [1, 1, 2, 4, 7]
y = [1, 2, 2, 2]
z = [1, 1, 3, 7]

UNION

x.union(y)           # => [1, 2, 4, 7]      (ONLY IN RUBY 2.6)
x.union(y, z)        # => [1, 2, 4, 7, 3]   (ONLY IN RUBY 2.6)
x | y                # => [1, 2, 4, 7]

DIFFERENCE

x.difference(y)      # => [4, 7] (ONLY IN RUBY 2.6)
x.difference(y, z)   # => [4] (ONLY IN RUBY 2.6)
x - y                # => [4, 7]

INTERSECTION

x & y                # => [1, 2]

For more info about the new methods in Ruby 2.6, you can check this blog post about its new features

Can I change the name of `nohup.out`?

my start.sh file:

#/bin/bash

nohup forever -c php artisan your:command >>storage/logs/yourcommand.log 2>&1 &

There is one important thing only. FIRST COMMAND MUST BE "nohup", second command must be "forever" and "-c" parameter is forever's param, "2>&1 &" area is for "nohup". After running this line then you can logout from your terminal, relogin and run "forever restartall" voilaa... You can restart and you can be sure that if script halts then forever will restart it.

I <3 forever

Unable to set variables in bash script

Five problems:

  1. Don't put a space before or after the equal sign.
  2. Use "$(...)" to get the output of a command as text.
  3. [ is a command. Put a space between it and the arguments.
  4. Commands are case-sensitive. You want echo.
  5. Use double quotes around variables. rm "$folderToBeMoved"

What is the result of % in Python?

% Modulo operator can be also used for printing strings (Just like in C) as defined on Google https://developers.google.com/edu/python/strings.

      # % operator
  text = "%d little pigs come out or I'll %s and %s and %s" % (3, 'huff', 'puff', 'blow down')

This seems to bit off topic but It will certainly help someone.

How to initialize static variables

best way is to create an accessor like this:

/**
* @var object $db : map to database connection.
*/
public static $db= null; 

/**
* db Function for initializing variable.   
* @return object
*/
public static function db(){
 if( !isset(static::$db) ){
  static::$db= new \Helpers\MySQL( array(
    "hostname"=> "localhost",
    "username"=> "root",
    "password"=> "password",
    "database"=> "db_name"
    )
  );
 }
 return static::$db;
}

then you can do static::db(); or self::db(); from anywhere.

How to resize Image in Android?

BitmapFactory.Options options=new BitmapFactory.Options();
            options.inSampleSize = 10;
            FixBitmap = BitmapFactory.decodeFile(ImagePath, options);
            //FixBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.gv);

           byteArrayOutputStream = new ByteArrayOutputStream();
           FixBitmap.compress(Bitmap.CompressFormat.JPEG, 80, byteArrayOutputStream); //compress to 50% of original image quality
           byteArray = byteArrayOutputStream.toByteArray();

           ConvertImage = Base64.encodeToString(byteArray, Base64.DEFAULT);

How to convert image into byte array and byte array to base64 String in android?

Try this simple solution to convert file to base64 string

String base64String = imageFileToByte(file);

public String imageFileToByte(File file){

    Bitmap bm = BitmapFactory.decodeFile(file.getAbsolutePath());
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    bm.compress(Bitmap.CompressFormat.JPEG, 100, baos); //bm is the bitmap object
    byte[] b = baos.toByteArray();
    return Base64.encodeToString(b, Base64.DEFAULT);
}

Make a link use POST instead of GET

Check this it will help you

$().redirect('test.php', {'a': 'value1', 'b': 'value2'});

How do I make a https post in Node Js without any third party module?

For example, like this:

const querystring = require('querystring');
const https = require('https');

var postData = querystring.stringify({
    'msg' : 'Hello World!'
});

var options = {
  hostname: 'posttestserver.com',
  port: 443,
  path: '/post.php',
  method: 'POST',
  headers: {
       'Content-Type': 'application/x-www-form-urlencoded',
       'Content-Length': postData.length
     }
};

var req = https.request(options, (res) => {
  console.log('statusCode:', res.statusCode);
  console.log('headers:', res.headers);

  res.on('data', (d) => {
    process.stdout.write(d);
  });
});

req.on('error', (e) => {
  console.error(e);
});

req.write(postData);
req.end();

.prop('checked',false) or .removeAttr('checked')?

use checked : true, false property of the checkbox.

jQuery:

if($('input[type=checkbox]').is(':checked')) {
    $(this).prop('checked',true);
} else {
    $(this).prop('checked',false);
}

Character reading from file in Python

This is Pythons way do show you unicode encoded strings. But i think you should be able to print the string on the screen or write it into a new file without any problems.

>>> test = u"I don\u2018t like this"
>>> test
u'I don\u2018t like this'
>>> print test
I don‘t like this

Getting error: ISO C++ forbids declaration of with no type

Your declaration is int ttTreeInsert(int value);

However, your definition/implementation is

ttTree::ttTreeInsert(int value)
{
}

Notice that the return type int is missing in the implementation. Instead it should be

int ttTree::ttTreeInsert(int value)
{
    return 1; // or some valid int
}

Best way to compare 2 XML documents in Java

Since you say "semantically equivalent" I assume you mean that you want to do more than just literally verify that the xml outputs are (string) equals, and that you'd want something like

<foo> some stuff here</foo></code>

and

<foo>some stuff here</foo></code>

do read as equivalent. Ultimately it's going to matter how you're defining "semantically equivalent" on whatever object you're reconstituting the message from. Simply build that object from the messages and use a custom equals() to define what you're looking for.

How to stop tracking and ignore changes to a file in Git?

after search a long time , find a way do this . alias a git command in .gitconfig.like in android studio project,before checkout branch revert config file and then skip it ,after checkout branch use sed change config file to my local config. checkoutandmodifylocalproperties = !git update-index --no-skip-worktree local.properties && git checkout local.properties && git checkout $1 && git update-index --skip-worktree local.properties && sed -i '' 's/.*sdk.dir.*/sdk.dir=\\/Users\\/run\\/Library\\/Android\\/sdk/g' local.properties && :

What evaluates to True/False in R?

If you think about it, comparing numbers to logical statements doesn't make much sense. However, since 0 is often associated with "Off" or "False" and 1 with "On" or "True", R has decided to allow 1 == TRUE and 0 == FALSE to both be true. Any other numeric-to-boolean comparison should yield false, unless it's something like 3 - 2 == TRUE.

How to disable right-click context-menu in JavaScript

If you don't care about alerting the user with a message every time they try to right click, try adding this to your body tag

<body oncontextmenu="return false;">

This will block all access to the context menu (not just from the right mouse button but from the keyboard as well)

However, there really is no point adding a right click disabler. Anyone with basic browser knowledge can view the source and extract the information they need.

How to style a select tag's option element?

Since version 49+, Chrome has supported styling <option> elements with font-weight. Source: https://code.google.com/p/chromium/issues/detail?id=44917#c22

New SELECT Popup: font-weight style should be applied.

This CL removes themeChromiumSkia.css. |!important| in it prevented to apply font-weight. Now html.css has |font-weight:normal|, and |!important| should be unnecessary.

There was a Chrome stylesheet, themeChromiumSkia.css, that used font-weight: normal !important; in it all this time. It was introduced to the stable Chrome channel in version 49.0.

How do I crop an image in Java?

There are two potentially major problem with the leading answer to this question. First, as per the docs:

public BufferedImage getSubimage(int x, int y, int w, int h)

Returns a subimage defined by a specified rectangular region. The returned BufferedImage shares the same data array as the original image.

Essentially, what this means is that result from getSubimage acts as a pointer which points at a subsection of the original image.

Why is this important? Well, if you are planning to edit the subimage for any reason, the edits will also happen to the original image. For example, I ran into this problem when I was using the smaller image in a separate window to zoom in on the original image. (kind of like a magnifying glass). I made it possible to invert the colors to see certain details more easily, but the area that was "zoomed" also got inverted in the original image! So there was a small section of the original image that had inverted colors while the rest of it remained normal. In many cases, this won't matter, but if you want to edit the image, or if you just want a copy of the cropped section, you might want to consider a method.

Which brings us to the second problem. Fortunately, it is not as big a problem as the first. getSubImage shares the same data array as the original image. That means that the entire original image is still stored in memory. Assuming that by "crop" the image you actually want a smaller image, you will need to redraw it as a new image rather than just get the subimage.

Try this:

BufferedImage img = image.getSubimage(startX, startY, endX, endY); //fill in the corners of the desired crop location here
BufferedImage copyOfImage = new BufferedImage(img.getWidth(), img.getHeight(), BufferedImage.TYPE_INT_RGB);
Graphics g = copyOfImage.createGraphics();
g.drawImage(img, 0, 0, null);
return copyOfImage; //or use it however you want

This technique will give you the cropped image you are looking for by itself, without the link back to the original image. This will preserve the integrity of the original image as well as save you the memory overhead of storing the larger image. (If you do dump the original image later)

Escaping single quotes in JavaScript string for JavaScript evaluation

Only this worked for me:

searchKeyword.replace(/'/g, "\\\'");//searchKeyword contains "d'av"

So, the result variable will contain "d\'av".

I don't know why with the RegEx didn't work, maybe because of the JS framework that I'm using (Backbone.js)

How do I filter an array with AngularJS and use a property of the filtered object as the ng-model attribute?

Applying same filter in HTML with multiple columns, just example:

 variable = (array | filter : {Lookup1Id : subject.Lookup1Id, Lookup2Id : subject.Lookup2Id} : true)

Returning Month Name in SQL Server Query

Have you tried DATENAME(MONTH, S0.OrderDateTime) ?

Chrome, Javascript, window.open in new tab

Clear mini-solution $('<form action="http://samedomainurl.com/" target="_blank"></form>').submit()

Laravel 5 Class 'form' not found

I have tried everything, but only this helped:

php artisan route:clear
php artisan cache:clear

Concatenate two char* strings in a C program

strcat(str1, str2) appends str2 after str1. It requires str1 to have enough space to hold str2. In you code, str1 and str2 are all string constants, so it should not work. You may try this way:

char str1[1024];
char *str2 = "kkkk";
strcpy(str1, "ssssss");
strcat(str1, str2);
printf("%s", str1);

Save range to variable

My use case was to save range to variable and then select it later on

Dim targetRange As Range
Set targetRange = Sheets("Sheet").Range("Name")
Application.Goto targetRange
Set targetRangeQ = Nothing ' reset

Android Device Chooser -- device not showing up

If none of the options work, I change the port and then enable USB debugging and it works fine.

What happened to the .pull-left and .pull-right classes in Bootstrap 4?

For anyone else and just an addition to Robert, If your nav has flex display value, you can float the element that you need to the right, by adding this to its css

{
    margin-left: auto;
}

JQuery Event for user pressing enter in a textbox?

Here is a plugin for you: (Fiddle: http://jsfiddle.net/maniator/CjrJ7/)

$.fn.pressEnter = function(fn) {  

    return this.each(function() {  
        $(this).bind('enterPress', fn);
        $(this).keyup(function(e){
            if(e.keyCode == 13)
            {
              $(this).trigger("enterPress");
            }
        })
    });  
 }; 

//use it:
$('textarea').pressEnter(function(){alert('here')})

Weblogic Transaction Timeout : how to set in admin console in WebLogic AS 8.1

After logging in, on the home page of the Server Console you should see 3 sections:

  • Information and Resources
  • Domain Configurations
  • Services Configurations

Under Services Configurations there is subsection Other Services. Click the JTA Configuration link under Other Services. The transaction timeout should be the top setting on the page displayed, labelled Timeout Seconds.

Weblogic Console screenshot

Why does SSL handshake give 'Could not generate DH keypair' exception?

We got the same exact exception error returned, to fix it was easy after hours surfing the internet.

We downloaded the highest version of jdk we could find on oracle.com, installed it and pointed Jboss application server to the directory of the installed new jdk.

Restarted Jboss, reprocessed, problemo fixed!!!

When should I use Memcache instead of Memcached?

Memcached client library was just recently released as stable. It is being used by digg ( was developed for digg by Andrei Zmievski, now no longer with digg) and implements much more of the memcached protocol than the older memcache client. The most important features that memcached has are:

  1. Cas tokens. This made my life much easier and is an easy preventive system for stale data. Whenever you pull something from the cache, you can receive with it a cas token (a double number). You can than use that token to save your updated object. If no one else updated the value while your thread was running, the swap will succeed. Otherwise a newer cas token was created and you are forced to reload the data and save it again with the new token.
  2. Read through callbacks are the best thing since sliced bread. It has simplified much of my code.
  3. getDelayed() is a nice feature that can reduce the time your script has to wait for the results to come back from the server.
  4. While the memcached server is supposed to be very stable, it is not the fastest. You can use binary protocol instead of ASCII with the newer client.
  5. Whenever you save complex data into memcached the client used to always do serialization of the value (which is slow), but now with memcached client you have the option of using igbinary. So far I haven't had the chance to test how much of a performance gain this can be.

All of this points were enough for me to switch to the newest client, and can tell you that it works like a charm. There is that external dependency on the libmemcached library, but have managed to install it nonetheless on Ubuntu and Mac OSX, so no problems there so far.

If you decide to update to the newer library, I suggest you update to the latest server version as well as it has some nice features as well. You will need to install libevent for it to compile, but on Ubuntu it wasn't much trouble.

I haven't seen any frameworks pick up the new memcached client thus far (although I don't keep track of them), but I presume Zend will get on board shortly.

UPDATE

Zend Framework 2 has an adapter for Memcached which can be found here

Android Studio - ADB Error - "...device unauthorized. Please check the confirmation dialog on your device."

Seems strange the intricate cable&restart solution steps ... The first time I've plugged the Android device to my Ubuntu (15.10) I've got Connect as: multimedia or camera options and in my Android Studio the device status was unauthorized. It wasn't until I choose between one of the options that I got in the Android device the PC authorization option. When you give the proper permissions in Android then the device status changed to online in Android Studio. Cheers

UIView background color in Swift

You can use this extension as an alternative if you're dealing with RGB value.

extension UIColor {
    static func rgb(red: CGFloat, green: CGFloat, blue: CGFloat) -> UIColor {
        return UIColor(red: red/255, green: green/255, blue: blue/255, alpha: 1)
      }
    }

Change Oracle port from port 8080

Login in with System Admin User Account and execute below SQL Procedure.

begin
dbms_xdb.sethttpport('Your Port Number');
end;

Then open the Browser and access the below URL

http://127.0.0.1:YourPortNumber/apex/

How do I hide the bullets on my list for the sidebar?

its on you ul in the file http://ratest4.com/wp-content/themes/HarnettArts-BP-2010/style.css on line 252

add this to your css

ul{
     list-style:none;
}

Can I use CASE statement in a JOIN condition?

This seems nice

https://bytes.com/topic/sql-server/answers/881862-joining-different-tables-based-condition

FROM YourMainTable
LEFT JOIN AirportCity DepCity ON @TravelType = 'A' and DepFrom =  DepCity.Code
LEFT JOIN AirportCity DepCity ON @TravelType = 'B' and SomeOtherColumn = SomeOtherColumnFromSomeOtherTable

Is Safari on iOS 6 caching $.ajax results?

For those that use Struts 1, here is how I fixed the issue.

web.xml

<filter>
    <filter-name>SetCacheControl</filter-name>
    <filter-class>com.example.struts.filters.CacheControlFilter</filter-class>
</filter>

<filter-mapping>
    <filter-name>SetCacheControl</filter-name>
    <url-pattern>*.do</url-pattern>
    <http-method>POST</http-method>
</filter-mapping>

com.example.struts.filters.CacheControlFilter.js

package com.example.struts.filters;

import java.io.IOException;
import java.util.Date;
import javax.servlet.*;
import javax.servlet.http.HttpServletResponse;

public class CacheControlFilter implements Filter {

        public void doFilter(ServletRequest request, ServletResponse response,
                     FilterChain chain) throws IOException, ServletException {

        HttpServletResponse resp = (HttpServletResponse) response;
        resp.setHeader("Expires", "Mon, 18 Jun 1973 18:00:00 GMT");
        resp.setHeader("Last-Modified", new Date().toString());
        resp.setHeader("Cache-Control", "no-store, no-cache, must-revalidate, max-age=0, post-check=0, pre-check=0");
        resp.setHeader("Pragma", "no-cache");

        chain.doFilter(request, response);
    }

    public void init(FilterConfig filterConfig) throws ServletException {
    }

    public void destroy() {
    }

}

How to Maximize a firefox browser window using Selenium WebDriver with node.js

The statement :: driver.manage().window.maximize(); Works perfectly, but the window maximizes only after loading the page on browser, it does not maximizes at the time of initializing the browser.

here : (driver) is called object of Firefox driver, it may be any thing depending on the initializing of Firefox object by you only.

Swift 2: Call can throw, but it is not marked with 'try' and the error is not handled

You have to catch the error just as you're already doing for your save() call and since you're handling multiple errors here, you can try multiple calls sequentially in a single do-catch block, like so:

func deleteAccountDetail() {
    let entityDescription = NSEntityDescription.entityForName("AccountDetail", inManagedObjectContext: Context!)
    let request = NSFetchRequest()
    request.entity = entityDescription

    do {
        let fetchedEntities = try self.Context!.executeFetchRequest(request) as! [AccountDetail]

        for entity in fetchedEntities {
            self.Context!.deleteObject(entity)
        }

        try self.Context!.save()
    } catch {
        print(error)
    }
}

Or as @bames53 pointed out in the comments below, it is often better practice not to catch the error where it was thrown. You can mark the method as throws then try to call the method. For example:

func deleteAccountDetail() throws {
    let entityDescription = NSEntityDescription.entityForName("AccountDetail", inManagedObjectContext: Context!)
    let request = NSFetchRequest()

    request.entity = entityDescription

    let fetchedEntities = try Context.executeFetchRequest(request) as! [AccountDetail]

    for entity in fetchedEntities {
        self.Context!.deleteObject(entity)
    }

    try self.Context!.save()
}

How to modify a specified commit?

For me it was for removing some credentials from a repo. I tried rebasing and ran into a ton of seemingly unrelated conflicts along the way when trying to rebase --continue. Don't bother attempting to rebase yourself, use the tool called BFG (brew install bfg) on mac.

Get month name from date in Oracle

If you are trying to pull the value from a field, you could use:

select extract(month from [field_name])
from [table_name]

You can also insert day or year for the "month" extraction value above.

How to validate domain name in PHP?

If you can run shell commands, following is the best way to determine if a domain is registered.

This function returns false, if domain name isn't registered else returns domain name.

function get_domain_name($domain) { 
    //Step 1 - Return false if any shell sensitive chars or space/tab were found
    if(escapeshellcmd($domain)!=$domain || count(explode(".", $domain))<2 || preg_match("/[\s\t]/", $domain)) {
            return false;
    }

    //Step 2 - Get the root domain in-case of subdomain
    $domain = (count(explode(".", $domain))>2 ? strtolower(explode(".", $domain)[count(explode(".", $domain))-2].".".explode(".", $domain)[count(explode(".", $domain))-1]) : strtolower($domain));

    //Step 3 - Run shell command 'dig' to get SOA servers for the domain extension
    $ns = shell_exec(escapeshellcmd("dig +short SOA ".escapeshellarg(explode(".", $domain)[count(explode(".", $domain))-1]))); 

    //Step 4 - Return false if invalid extension (returns NULL), or take the first server address out of output
    if($ns===NULL) {
            return false;
    }
    $ns = (((preg_split('/\s+/', $ns)[0])[strlen(preg_split('/\s+/', $ns)[0])-1]==".") ? substr(preg_split('/\s+/', $ns)[0], 0, strlen(preg_split('/\s+/', $ns)[0])-1) : preg_split('/\s+/', $ns)[0]);

    //Step 5 - Run another dig using the obtained address for our domain, and return false if returned NULL else return the domain name. This assumes an authoritative NS is assigned when a domain is registered, can be improved to filter more accurately.
    $ans = shell_exec(escapeshellcmd("dig +noall +authority ".escapeshellarg("@".$ns)." ".escapeshellarg($domain))); 
    return (($ans===NULL) ? false : ((strpos($ans, $ns)>-1) ? false : $domain));
}

Pros

  1. Works on any domain, while php dns functions may fail on some domains. (my .pro domain failed on php dns)
  2. Works on fresh domains without any dns (like A) records
  3. Unicode friendly

Cons

  1. Usage of shell execution, probably

SQL distinct for 2 fields in a database

How about simply:

select distinct c1, c2 from t

or

select c1, c2, count(*)
from t
group by c1, c2

How should I validate an e-mail address?

Kotlin Extension Function

fun EditText.isValidEmail() : Boolean{
    return if(Pattern
            .compile("^[_A-Za-z0-9-]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$")
            .matcher(text.toString()).matches()){
        true
    }else {
        hint = context.getString(R.string.invalid_email_adress)
        false
    }
}

Use

if(!emailEt.isValidEmail()){
    return
}

What is considered a good response time for a dynamic, personalized web application?

Our company has a 5 second response time standard limit, and we aim for 2-3 seconds in general. This accounts for 98% of page loads. A few particular tasks are allowed to go up to 15 seconds, but we then mitigate that time by putting up a page and refreshing every 5 seconds telling the user that we are still trying to process the request. That way the user sees that something is happening and doesn't just leave. Although, considering that I work on a website whose users are forced to use for business reasons, they aren't going to leave, but they are capable of complaining quite loudly.

In general, if the processing is going to take more than 5 seconds, put up a temporary page so that the user doesn't lose interest.

correct PHP headers for pdf file download

I had the same problem recently and this helped me:

    header('Content-Description: File Transfer'); 
    header('Content-Type: application/octet-stream'); 
    header('Content-Disposition: attachment; filename="FILENAME"'); 
    header('Content-Transfer-Encoding: binary'); 
    header('Expires: 0'); 
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0'); 
    header('Pragma: public'); 
    header('Content-Length: ' . filesize("PATH/TO/FILE")); 
    ob_clean(); 
    flush(); 
    readfile(PATH/TO/FILE);      
    exit();

I found this answer here

/** and /* in Java Comments

The first form is called Javadoc. You use this when you're writing formal APIs for your code, which are generated by the javadoc tool. For an example, the Java 7 API page uses Javadoc and was generated by that tool.

Some common elements you'd see in Javadoc include:

  • @param: this is used to indicate what parameters are being passed to a method, and what value they're expected to have

  • @return: this is used to indicate what result the method is going to give back

  • @throws: this is used to indicate that a method throws an exception or error in case of certain input

  • @since: this is used to indicate the earliest Java version this class or function was available in

As an example, here's Javadoc for the compare method of Integer:

/**
 * Compares two {@code int} values numerically.
 * The value returned is identical to what would be returned by:
 * <pre>
 *    Integer.valueOf(x).compareTo(Integer.valueOf(y))
 * </pre>
 *
 * @param  x the first {@code int} to compare
 * @param  y the second {@code int} to compare
 * @return the value {@code 0} if {@code x == y};
 *         a value less than {@code 0} if {@code x < y}; and
 *         a value greater than {@code 0} if {@code x > y}
 * @since 1.7
 */
public static int compare(int x, int y) {
    return (x < y) ? -1 : ((x == y) ? 0 : 1);
}

The second form is a block (multi-line) comment. You use this if you want to have multiple lines in a comment.

I will say that you'd only want to use the latter form sparingly; that is, you don't want to overburden your code with block comments that don't describe what behaviors the method/complex function is supposed to have.

Since Javadoc is the more descriptive of the two, and you can generate actual documentation as a result of using it, using Javadoc would be more preferable to simple block comments.

Visual Studio Code: Auto-refresh file changes

VSCode will never refresh the file if you have changes in that file that are not saved to disk. However, if the file is open and does not have changes, it will replace with the changes on disk, that is true.

There is currently no way to disable this behaviour.

character count using jquery

For length including white-space:

$("#id").val().length

For length without white-space:

$("#id").val().replace(/ /g,'').length

For removing only beginning and trailing white-space:

$.trim($("#test").val()).length

For example, the string " t e s t " would evaluate as:

//" t e s t "
$("#id").val(); 

//Example 1
$("#id").val().length; //Returns 9
//Example 2
$("#id").val().replace(/ /g,'').length; //Returns 4
//Example 3
$.trim($("#test").val()).length; //Returns 7

Here is a demo using all of them.

Keytool is not recognized as an internal or external command

Run the cmd as run as administrator this worked for me

How Do I 'git fetch' and 'git merge' from a Remote Tracking Branch (like 'git pull')

Git pull is actually a combo tool: it runs git fetch (getting the changes) and git merge (merging them with your current copy)

Are you sure you are on the correct branch?

Remove empty array elements

You can use array_filter to remove empty elements:

$emptyRemoved = array_filter($linksArray);

If you have (int) 0 in your array, you may use the following:

$emptyRemoved = remove_empty($linksArray);

function remove_empty($array) {
  return array_filter($array, '_remove_empty_internal');
}

function _remove_empty_internal($value) {
  return !empty($value) || $value === 0;
}

EDIT: Maybe your elements are not empty per se but contain one or more spaces... You can use the following before using array_filter

$trimmedArray = array_map('trim', $linksArray);

Does JavaScript have a built in stringbuilder class?

No, there is no built-in support for building strings. You have to use concatenation instead.

You can, of course, make an array of different parts of your string and then call join() on that array, but it then depends on how the join is implemented in the JavaScript interpreter you are using.

I made an experiment to compare the speed of str1+str2 method versus array.push(str1, str2).join() method. The code was simple:

var iIterations =800000;
var d1 = (new Date()).valueOf();
str1 = "";
for (var i = 0; i<iIterations; i++)
    str1 = str1 + Math.random().toString();
var d2 = (new Date()).valueOf();
log("Time (strings): " + (d2-d1));

var d3 = (new Date()).valueOf();
arr1 = [];
for (var i = 0; i<iIterations; i++)
    arr1.push(Math.random().toString());
var str2 = arr1.join("");
var d4 = (new Date()).valueOf();
log("Time (arrays): " + (d4-d3));

I tested it in Internet Explorer 8 and Firefox 3.5.5, both on a Windows 7 x64.

In the beginning I tested on small number of iterations (some hundred, some thousand items). The results were unpredictable (sometimes string concatenation took 0 milliseconds, sometimes it took 16 milliseconds, the same for array joining).

When I increased the count to 50,000, the results were different in different browsers - in Internet Explorer the string concatenation was faster (94 milliseconds) and join was slower(125 milliseconds), while in Firefox the array join was faster (113 milliseconds) than string joining (117 milliseconds).

Then I increased the count to 500'000. Now the array.join() was slower than string concatenation in both browsers: string concatenation was 937 ms in Internet Explorer, 1155 ms in Firefox, array join 1265 in Internet Explorer, and 1207 ms in Firefox.

The maximum iteration count I could test in Internet Explorer without having "the script is taking too long to execute" was 850,000. Then Internet Explorer was 1593 for string concatenation and 2046 for array join, and Firefox had 2101 for string concatenation and 2249 for array join.

Results - if the number of iterations is small, you can try to use array.join(), as it might be faster in Firefox. When the number increases, the string1+string2 method is faster.

UPDATE

I performed the test on Internet Explorer 6 (Windows XP). The process stopped to respond immediately and never ended, if I tried the test on more than 100,000 iterations. On 40,000 iterations the results were

Time (strings): 59175 ms
Time (arrays): 220 ms

This means - if you need to support Internet Explorer 6, choose array.join() which is way faster than string concatenation.

What is the equivalent of Java's final in C#?

The final keyword has several usages in Java. It corresponds to both the sealed and readonly keywords in C#, depending on the context in which it is used.

Classes

To prevent subclassing (inheritance from the defined class):

Java

public final class MyFinalClass {...}

C#

public sealed class MyFinalClass {...}

Methods

Prevent overriding of a virtual method.

Java

public class MyClass
{
    public final void myFinalMethod() {...}
}

C#

public class MyClass : MyBaseClass
{
    public sealed override void MyFinalMethod() {...}
}

As Joachim Sauer points out, a notable difference between the two languages here is that Java by default marks all non-static methods as virtual, whereas C# marks them as sealed. Hence, you only need to use the sealed keyword in C# if you want to stop further overriding of a method that has been explicitly marked virtual in the base class.

Variables

To only allow a variable to be assigned once:

Java

public final double pi = 3.14; // essentially a constant

C#

public readonly double pi = 3.14; // essentially a constant

As a side note, the effect of the readonly keyword differs from that of the const keyword in that the readonly expression is evaluated at runtime rather than compile-time, hence allowing arbitrary expressions.

Is it possible to view RabbitMQ message contents directly from the command line?

If you want multiple messages from a queue, say 10 messages, the command to use is:

rabbitmqadmin get queue=<QueueName> ackmode=ack_requeue_true count=10

If you don't want the messages requeued, just change ackmode to ack_requeue_false.

bootstrap 4 row height

Use the sizing utility classes...

  • h-50 = height 50%
  • h-100 = height 100%

http://www.codeply.com/go/Y3nG0io2uE

 <div class="container">
        <div class="row">
            <div class="col-md-8 col-lg-6 B">
                <div class="card card-inverse card-primary">
                    <img src="http://lorempicsum.com/rio/800/500/4" class="img-fluid" alt="Responsive image">
                </div>
            </div>
            <div class="col-md-4 col-lg-3 G">
                <div class="row h-100">
                    <div class="col-md-6 col-lg-6 B h-50 pb-3">
                        <div class="card card-inverse card-success h-100">

                        </div>
                    </div>
                    <div class="col-md-6 col-lg-6 B h-50 pb-3">
                        <div class="card card-inverse bg-success h-100">

                        </div>
                    </div>
                    <div class="col-md-12 h-50">
                        <div class="card card-inverse bg-danger h-100">

                        </div>
                    </div>
                </div>
            </div>
        </div>
    </div>

Or, for an unknown number of child columns, use flexbox and the cols will fill height. See the d-flex flex-column on the row, and h-100 on the child cols.

<div class="container">
    <div class="row">
        <div class="col-md-8 col-lg-6 B">
            <div class="card card-inverse card-primary">
                <img src="http://lorempicsum.com/rio/800/500/4" class="img-fluid" alt="Responsive image">
            </div>
        </div>
        <div class="col-md-4 col-lg-3 G ">
            <div class="row d-flex flex-column h-100">
                <div class="col-md-6 col-lg-6 B h-100">
                    <div class="card bg-success h-100">

                    </div>
                </div>
                <div class="col-md-6 col-lg-6 B h-100">
                    <div class="card bg-success h-100">

                    </div>
                </div>
                <div class="col-md-12 h-100">
                    <div class="card bg-danger h-100">

                    </div>
                </div>
            </div>
        </div>
    </div>
</div>

https://www.codeply.com/go/tgzFAH8vaW

Git command to display HEAD commit id?

You can use

git log -g branchname

to see git reflog information formatted like the git log output

Where is Python's sys.path initialized from?

"Initialized from the environment variable PYTHONPATH, plus an installation-dependent default"

-- http://docs.python.org/library/sys.html#sys.path

How to convert the ^M linebreak to 'normal' linebreak in a file opened in vim?

A file I had created with BBEdit seen in MacVim was displaying a bunch of ^M line returns instead of regular ones. The following string replace solved the issue - hope this helps:

:%s/\r/\r/g

It's interesting because I'm replacing line breaks with the same character, but I suppose Vim just needs to get a fresh \r to display correctly. I'd be interested to know the underlying mechanics of why this works.

Get the element with the highest occurrence in an array

Time for another solution:

function getMaxOccurrence(arr) {
    var o = {}, maxCount = 0, maxValue, m;
    for (var i=0, iLen=arr.length; i<iLen; i++) {
        m = arr[i];

        if (!o.hasOwnProperty(m)) {
            o[m] = 0;
        }
        ++o[m];

        if (o[m] > maxCount) {
            maxCount = o[m];
            maxValue = m;
        }
    }
    return maxValue;
}

If brevity matters (it doesn't), then:

function getMaxOccurrence(a) {
    var o = {}, mC = 0, mV, m;
    for (var i=0, iL=a.length; i<iL; i++) {
        m = a[i];
        o.hasOwnProperty(m)? ++o[m] : o[m] = 1;
        if (o[m] > mC) mC = o[m], mV = m;
    }
    return mV;
}

If non–existent members are to be avoided (e.g. sparse array), an additional hasOwnProperty test is required:

function getMaxOccurrence(a) {
    var o = {}, mC = 0, mV, m;
    for (var i=0, iL=a.length; i<iL; i++) {
        if (a.hasOwnProperty(i)) {
            m = a[i];
            o.hasOwnProperty(m)? ++o[m] : o[m] = 1;
            if (o[m] > mC) mC = o[m], mV = m;
        }
    }
    return mV;
}

getMaxOccurrence([,,,,,1,1]); // 1

Other answers here will return undefined.

Oracle "Partition By" Keyword

It is the SQL extension called analytics. The "over" in the select statement tells oracle that the function is a analytical function, not a group by function. The advantage to using analytics is that you can collect sums, counts, and a lot more with just one pass through of the data instead of looping through the data with sub selects or worse, PL/SQL.

It does look confusing at first but this will be second nature quickly. No one explains it better then Tom Kyte. So the link above is great.

Of course, reading the documentation is a must.

Case-insensitive search in Rails model

Find_or_create is now deprecated, you should use an AR Relation instead plus first_or_create, like so:

TombolaEntry.where("lower(name) = ?", self.name.downcase).first_or_create(name: self.name)

This will return the first matched object, or create one for you if none exists.

How to remove not null constraint in sql server using query

 ALTER TABLE YourTable ALTER COLUMN YourColumn columnType NULL

How to attach a file using mail command on Linux?

On Linux I would suggest,

# FILE_TO_BE_ATTACHED=abc.gz

uuencode abc.gz abc.gz > abc.gz.enc # This is optional, but good to have
                                    # to prevent binary file corruption.
                                    # also it make sure to get original 
                                    # file on other system, w/o worry of endianness

# Sending Mail, multiple attachments, and multiple receivers.
echo "Body Part of Mail" | mailx -s "Subject Line" -a attachment1 -a abc.gz.enc "[email protected] [email protected]"

Upon receiving mail attachment, if you have used uuencode, you would need uudecode

uudecode abc.gz.enc

# This will generate file as original with name as same as the 2nd argument for uuencode.

HTML - Change\Update page contents without refreshing\reloading the page

You've got the right idea, so here's how to go ahead: the onclick handlers run on the client side, in the browser, so you cannot call a PHP function directly. Instead, you need to add a JavaScript function that (as you mentioned) uses AJAX to call a PHP script and retrieve the data. Using jQuery, you can do something like this:

<script type="text/javascript">
function recp(id) {
  $('#myStyle').load('data.php?id=' + id);
}
</script>

<a href="#" onClick="recp('1')" > One   </a>
<a href="#" onClick="recp('2')" > Two   </a>
<a href="#" onClick="recp('3')" > Three </a>

<div id='myStyle'>
</div>

Then you put your PHP code into a separate file: (I've called it data.php in the above example)

<?php
  require ('myConnect.php');     
  $id = $_GET['id'];
  $results = mysql_query("SELECT para FROM content WHERE  para_ID='$id'");   
  if( mysql_num_rows($results) > 0 )
  {
   $row = mysql_fetch_array( $results );
   echo $row['para'];
  }
?>

How do I kill a process using Vb.NET or C#?

I opened one Word file, 2. Now I open another word file through vb.net runtime programmatically. 3. I want to kill the second process alone through programmatically. 4. Do not kill first process

How do I indent multiple lines at once in Notepad++?

in Notepad++v6.1.8 (Unicode) it works after removing the QuickText plugin.

array.select() in javascript

yo can extend your JS with a select method like this

Array.prototype.select = function(closure){
    for(var n = 0; n < this.length; n++) {
        if(closure(this[n])){
            return this[n];
        }
    }

    return null;
};

now you can use this:

var x = [1,2,3,4];

var a = x.select(function(v) {
    return v == 2;
});

console.log(a);

or for objects in a array

var x = [{id: 1, a: true},
    {id: 2, a: true},
    {id: 3, a: true},
    {id: 4, a: true}];

var a = x.select(function(obj) {
    return obj.id = 2;
});

console.log(a);

How to loop and render elements in React-native?

For initial array, better use object instead of array, as then you won't be worrying about the indexes and it will be much more clear what is what:

const initialArr = [{
    color: "blue",
    text: "text1"
}, {
    color: "red",
    text: "text2"
}];

For actual mapping, use JS Array map instead of for loop - for loop should be used in cases when there's no actual array defined, like displaying something a certain number of times:

onPress = () => {
    ...
};

renderButtons() {
    return initialArr.map((item) => {
        return (
            <Button 
                style={{ borderColor: item.color }}
                onPress={this.onPress}
            >
                {item.text}
            </Button>
        );
    });
}

...

render() {
    return (
        <View style={...}>
            {
                this.renderButtons()
            }
        </View>
    )
}

I moved the mapping to separate function outside of render method for more readable code. There are many other ways to loop through list of elements in react native, and which way you'll use depends on what do you need to do. Most of these ways are covered in this article about React JSX loops, and although it's using React examples, everything from it can be used in React Native. Please check it out if you're interested in this topic!

Also, not on the topic on the looping, but as you're already using the array syntax for defining the onPress function, there's no need to bind it again. This, again, applies only if the function is defined using this syntax within the component, as the arrow syntax auto binds the function.

BSTR to std::string (std::wstring) and vice versa

Simply pass the BSTR directly to the wstring constructor, it is compatible with a wchar_t*:

BSTR btest = SysAllocString(L"Test");
assert(btest != NULL);
std::wstring wtest(btest);
assert(0 == wcscmp(wtest.c_str(), btest));

Converting BSTR to std::string requires a conversion to char* first. That's lossy since BSTR stores a utf-16 encoded Unicode string. Unless you want to encode in utf-8. You'll find helper methods to do this, as well as manipulate the resulting string, in the ICU library.

Android - save/restore fragment state

Android fragment has some advantages and some disadvantages. The most disadvantage of the fragment is that when you want to use a fragment you create it ones. When you use it, onCreateView of the fragment is called for each time. If you want to keep state of the components in the fragment you must save fragment state and yout must load its state in the next shown. This make fragment view a bit slow and weird.

I have found a solution and I have used this solution: "Everything is great. Every body can try".

When first time onCreateView is being run, create view as a global variable. When second time you call this fragment onCreateView is called again you can return this global view. The fragment component state will be kept.

View view;

@Override
public View onCreateView(LayoutInflater inflater,
        @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    setActionBar(null);
    if (view != null) {
        if ((ViewGroup)view.getParent() != null)
            ((ViewGroup)view.getParent()).removeView(view);
        return view; 
    }
    view = inflater.inflate(R.layout.mylayout, container, false);
}

"Strict Standards: Only variables should be passed by reference" error

I had a similar problem.

I think the problem is that when you try to enclose two or more functions that deals with an array type of variable, php will return an error.

Let's say for example this one.

$data = array('key1' => 'Robert', 'key2' => 'Pedro', 'key3' => 'Jose');

// This function returns the last key of an array (in this case it's $data)
$lastKey = array_pop(array_keys($data));

// Output is "key3" which is the last array.
// But php will return “Strict Standards: Only variables should 
// be passed by reference” error.
// So, In order to solve this one... is that you try to cut 
// down the process one by one like this.

$data1  = array_keys($data);
$lastkey = array_pop($data1);

echo $lastkey;

There you go!

How do I add a project as a dependency of another project?

Assuming the MyEjbProject is not another Maven Project you own or want to build with maven, you could use system dependencies to link to the existing jar file of the project like so

<project>
   ...
   <dependencies>
      <dependency>
         <groupId>yourgroup</groupId>
         <artifactId>myejbproject</artifactId>
         <version>2.0</version>
         <scope>system</scope>
         <systemPath>path/to/myejbproject.jar</systemPath>
      </dependency>
   </dependencies>
   ...
</project>

That said it is usually the better (and preferred way) to install the package to the repository either by making it a maven project and building it or installing it the way you already seem to do.


If they are, however, dependent on each other, you can always create a separate parent project (has to be a "pom" project) declaring the two other projects as its "modules". (The child projects would not have to declare the third project as their parent). As a consequence you'd get a new directory for the new parent project, where you'd also quite probably put the two independent projects like this:

parent
|- pom.xml
|- MyEJBProject
|   `- pom.xml
`- MyWarProject
    `- pom.xml

The parent project would get a "modules" section to name all the child modules. The aggregator would then use the dependencies in the child modules to actually find out the order in which the projects are to be built)

<project>
   ...
   <artifactId>myparentproject</artifactId>
   <groupId>...</groupId>
   <version>...</version>

   <packaging>pom</packaging>
   ...
   <modules>
     <module>MyEJBModule</module>
     <module>MyWarModule</module>
   </modules>
   ...
</project>

That way the projects can relate to each other but (once they are installed in the local repository) still be used independently as artifacts in other projects


Finally, if your projects are not in related directories, you might try to give them as relative modules:

filesystem
 |- mywarproject
 |   `pom.xml
 |- myejbproject
 |   `pom.xml
 `- parent
     `pom.xml

now you could just do this (worked in maven 2, just tried it):

<!--parent-->
<project>
  <modules>
    <module>../mywarproject</module>
    <module>../myejbproject</module>
  </modules>
</project>

XMLHttpRequest cannot load file. Cross origin requests are only supported for HTTP

Simple Solution

If you are working with pure html/js/css files.

Install this small server(link) app in chrome. Open the app and point the file location to your project directory.

Goto the url shown in the app.

Edit: Smarter solution using Gulp

Step 1: To install Gulp. Run following command in your terminal.

npm install gulp-cli -g
npm install gulp -D

Step 2: Inside your project directory create a file named gulpfile.js. Copy the following content inside it.

var gulp        = require('gulp');
var bs          = require('browser-sync').create();   

gulp.task('serve', [], () => {
        bs.init({
            server: {
               baseDir: "./",
            },
            port: 5000,
            reloadOnRestart: true,
            browser: "google chrome"
        });
        gulp.watch('./**/*', ['', bs.reload]);
});

Step 3: Install browser sync gulp plugin. Inside the same directory where gulpfile.js is present, run the following command

npm install browser-sync gulp --save-dev

Step 4: Start the server. Inside the same directory where gulpfile.js is present, run the following command

gulp serve

How to remove an element from an array in Swift

Few Operation relates to Array in Swift

Create Array

var stringArray = ["One", "Two", "Three", "Four"]

Add Object in Array

stringArray = stringArray + ["Five"]

Get Value from Index object

let x = stringArray[1]

Append Object

stringArray.append("At last position")

Insert Object at Index

stringArray.insert("Going", at: 1)

Remove Object

stringArray.remove(at: 3)

Concat Object value

var string = "Concate Two object of Array \(stringArray[1]) + \(stringArray[2])"

How to add an extra source directory for maven to compile and include in the build jar?

NOTE: This solution will just move the java source files to the target/classes directory and will not compile the sources.

Update the pom.xml as -

<project>   
 ....
    <build>
      <resources>
        <resource>
          <directory>src/main/config</directory>
        </resource>
      </resources>
     ...
    </build>
...
</project>

Scrolling to an Anchor using Transition/CSS3

Here is a pure css solution using viewport units and variables that automatically scales to the device (and works on window resize). I added the following to Alex's solution:

        html,body {
            width: 100%;
            height: 100%;
            position: fixed;/* prevents scrolling */
            --innerheight: 100vh;/* variable 100% of viewport height */
        }

        body {
            overflow: hidden; /* prevents scrolling */
        }

        .panel {
            width: 100%;
            height: var(--innerheight); /* viewport height */

        a[ id= "galeria" ]:target ~ #main article.panel {
            -webkit-transform: translateY( calc(-1*var(--innerheight)) );
            transform: translateY( calc(-1*var(--innerheight)) );
        }

        a[ id= "contacto" ]:target ~ #main article.panel {
            -webkit-transform: translateY( calc(-2*var(--innerheight)) );
            transform: translateY( calc(-2*var(--innerheight)) );

Double precision floating values in Python?

Python's built-in float type has double precision (it's a C double in CPython, a Java double in Jython). If you need more precision, get NumPy and use its numpy.float128.

Difference in make_shared and normal shared_ptr in C++

There is another case where the two possibilities differ, on top of those already mentioned: if you need to call a non-public constructor (protected or private), make_shared might not be able to access it, while the variant with the new works fine.

class A
{
public:

    A(): val(0){}

    std::shared_ptr<A> createNext(){ return std::make_shared<A>(val+1); }
    // Invalid because make_shared needs to call A(int) **internally**

    std::shared_ptr<A> createNext(){ return std::shared_ptr<A>(new A(val+1)); }
    // Works fine because A(int) is called explicitly

private:

    int val;

    A(int v): val(v){}
};

What is key=lambda

In Python, lambda is a keyword used to define anonymous functions(functions with no name) and that's why they are known as lambda functions.

Basically it is used for defining anonymous functions that can/can't take argument(s) and returns value of data/expression. Let's see an example.

>>> # Defining a lambda function that takes 2 parameters(as integer) and returns their sum
... 
>>> lambda num1, num2: num1 + num2 
<function <lambda> at 0x1004b5de8>
>>> 
>>> # Let's store the returned value in variable & call it(1st way to call)
... 
>>> addition = lambda num1, num2: num1 + num2
>>> addition(62, 5)
67
>>> addition(1700, 29)
1729
>>> 
>>> # Let's call it in other way(2nd way to call, one line call )
... 
>>> (lambda num1, num2: num1 + num2)(120, 1)
121
>>> (lambda num1, num2: num1 + num2)(-68, 2)
-66
>>> (lambda num1, num2: num1 + num2)(-68, 2**3)
-60
>>> 

Now let me give an answer of your 2nd question. The 1st answer is also great. This is my own way to explain with another example.

Suppose we have a list of items(integers and strings with numeric contents) as follows,

nums = ["2", 1, 3, 4, "5", "8", "-1", "-10"]

and I want to sort it using sorted() function, lets see what happens.

>>> nums = ["2", 1, 3, 4, "5", "8", "-1", "-10"]
>>> sorted(nums)
[1, 3, 4, '-1', '-10', '2', '5', '8']
>>>

It didn't give me what I expected as I wanted like below,

['-10', '-1', 1, '2', 3, 4, '5', '8']

It means we need some strategy(so that sorted could treat our string items as an ints) to achieve this. This is why the key keyword argument is used. Please look at the below one.

>>> nums = ["2", 1, 3, 4, "5", "8", "-1", "-10"]
>>> sorted(nums, key=int)
['-10', '-1', 1, '2', 3, 4, '5', '8']
>>> 

Lets use lambda function as a value of key

>>> names = ["Rishikesh", "aman", "Ajay", "Hemkesh", "sandeep", "Darshan", "Virendra", "Shwetabh"]
>>> names2 = sorted(names)
>>> names2
['Ajay', 'Darshan', 'Hemkesh', 'Rishikesh', 'Shwetabh', 'Virendra', 'aman', 'sandeep']
>>> # But I don't want this o/p(here our intention is to treat 'a' same as 'A')
...
>>> names3 = sorted(names, key=lambda name:name.lower())
>>> names3
['Ajay', 'aman', 'Darshan', 'Hemkesh', 'Rishikesh', 'sandeep', 'Shwetabh', 'Virendra']
>>>

You can define your own function(callable) and provide it as value of key.

Dear programers, I have written the below code for you, just try to understand it and comment your explanation. I would be glad to see your explanation(it's simple).

>>> def validator(item):
...     try:
...         return int(item)
...     except:
...         return 0
... 
>>> sorted(['gurmit', "0", 5, 2, 1, "front", -2, "great"], key=validator)
[-2, 'gurmit', '0', 'front', 'great', 1, 2, 5]
>>>

I hope it would be useful.

Drop-down menu that opens up/upward with pure css

If we are use chosen dropdown list, then we can use below css(No JS/JQuery require)

<select chosen="{width: '100%'}" ng- 
   model="modelName" class="form-control input- 
   sm"
   ng- 
   options="persons.persons as 
   persons.persons for persons in 
   jsonData"
   ng- 
   change="anyFunction(anyParam)" 
   required>
   <option value=""> </option>
</select>
<style>   
.chosen-container .chosen-drop {
    border-bottom: 0;
    border-top: 1px solid #aaa;
    top: auto;
    bottom: 40px;
}

.chosen-container.chosen-with-drop .chosen-single {
    border-top-left-radius: 0px;
    border-top-right-radius: 0px;

    border-bottom-left-radius: 5px;
    border-bottom-right-radius: 5px;

    background-image: none;
}

.chosen-container.chosen-with-drop .chosen-drop {
    border-bottom-left-radius: 0px;
    border-bottom-right-radius: 0px;

    border-top-left-radius: 5px;
    border-top-right-radius: 5px;

    box-shadow: none;

    margin-bottom: -16px;
}
</style>

wait until all threads finish their work in java

An executor service can be used to manage multiple threads including status and completion. See http://programmingexamples.wikidot.com/executorservice

How to implement an android:background that doesn't stretch?

Here's a version of Santosh's answer for programmatically-created buttons, without the need for a separate XML configuration:

Button button = new Button(getContext());
Bitmap backgroundBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.my_button);
BitmapDrawable backgroundDrawable = new BitmapDrawable(getResources(), backgroundBitmap);
backgroundDrawable.setGravity(Gravity.CENTER); // also LEFT, CENTER_VERTICAL, etc.
backgroundDrawable.setColorFilter(new PorterDuffColorFilter(Color.RED, PorterDuff.Mode.SRC_ATOP));
button.setBackground(backgroundDrawable);

I included the ColorFilter line since that works a little differently from buttons with a normal background image.

WSDL vs REST Pros and Cons

The two protocols have very different uses in the real world.

SOAP(using WSDL) is a heavy-weight XML standard that is centered around document passing. The advantage with this is that your requests and responses can be very well structured, and can even use a DTD. The downside is it is XML, and is very verbose. However, this is good if two parties need to have a strict contract(say for inter-bank communication). SOAP also lets you layer things like WS-Security on your documents. SOAP is generally transport-agnostic, meaning you don't necessarily need to use HTTP.

REST is very lightweight, and relies upon the HTTP standard to do it's work. It is great to get a useful web service up and running quickly. If you don't need a strict API definition, this is the way to go. Most web services fall into this category. You can version your API so that updates to the API do not break it for people using old versions(as long as they specify a version). REST essentially requires HTTP, and is format-agnostic(meaning you can use XML, JSON, HTML, whatever).

Generally I use REST, because I don't need fancy WS-* features. SOAP is good though if you want computers to understand your webservice using a WSDL. REST specifications are generally human-readable only.

How to detect when an @Input() value changes in Angular?

This solution uses a proxy class and offers the following advantages:

  • Allows the consumer to leverage the power of RXJS
  • More compact than other solutions proposed so far
  • More typesafe than using ngOnChanges()

Example usage:

@Input()
public num: number;
numChanges$ = observeProperty(this as MyComponent, 'num');

Utility function:

export function observeProperty<T, K extends keyof T>(target: T, key: K) {
  const subject = new BehaviorSubject<T[K]>(target[key]);
  Object.defineProperty(target, key, {
    get(): T[K] { return subject.getValue(); },
    set(newValue: T[K]): void {
      if (newValue !== subject.getValue()) {
        subject.next(newValue);
      }
    }
  });
  return subject;
}

How to enable Bootstrap tooltip on disabled button?

Simply add the disabled class to the button instead of the disabled attribute to make it visibly disabled instead.

<button class="btn disabled" rel="tooltip" data-title="Dieser Link führt zu Google">button disabled</button>

Note: this button only appears to be disabled, but it still triggers events, and you just have to be mindful of that.

How can I output a UTF-8 CSV in PHP that Excel will read properly?

In my case following works very nice to make CSV file with UTF-8 chars displayed correctly in Excel.

$out = fopen('php://output', 'w');
fprintf($out, chr(0xEF).chr(0xBB).chr(0xBF));
fputcsv($out, $some_csv_strings);

The 0xEF 0xBB 0xBF BOM header will let Excel know the correct encoding.

How to quickly form groups (quartiles, deciles, etc) by ordering column(s) in a data frame

There is possibly a quicker way, but I would do:

a <- rnorm(100) # Our data
q <- quantile(a) # You can supply your own breaks, see ?quantile

# Define a simple function that checks in which quantile a number falls
getQuant <- function(x)
   {
   for (i in 1:(length(q)-1))
       {
       if (x>=q[i] && x<q[i+1])
          break;
       }
   i
   }

# Apply the function to the data
res <- unlist(lapply(as.matrix(a), getQuant))

What is Bit Masking?

A mask defines which bits you want to keep, and which bits you want to clear.

Masking is the act of applying a mask to a value. This is accomplished by doing:

  • Bitwise ANDing in order to extract a subset of the bits in the value
  • Bitwise ORing in order to set a subset of the bits in the value
  • Bitwise XORing in order to toggle a subset of the bits in the value

Below is an example of extracting a subset of the bits in the value:

Mask:   00001111b
Value:  01010101b

Applying the mask to the value means that we want to clear the first (higher) 4 bits, and keep the last (lower) 4 bits. Thus we have extracted the lower 4 bits. The result is:

Mask:   00001111b
Value:  01010101b
Result: 00000101b

Masking is implemented using AND, so in C we get:

uint8_t stuff(...) {
  uint8_t mask = 0x0f;   // 00001111b
  uint8_t value = 0x55;  // 01010101b
  return mask & value;
}

Here is a fairly common use-case: Extracting individual bytes from a larger word. We define the high-order bits in the word as the first byte. We use two operators for this, &, and >> (shift right). This is how we can extract the four bytes from a 32-bit integer:

void more_stuff(uint32_t value) {             // Example value: 0x01020304
    uint32_t byte1 = (value >> 24);           // 0x01020304 >> 24 is 0x01 so
                                              // no masking is necessary
    uint32_t byte2 = (value >> 16) & 0xff;    // 0x01020304 >> 16 is 0x0102 so
                                              // we must mask to get 0x02
    uint32_t byte3 = (value >> 8)  & 0xff;    // 0x01020304 >> 8 is 0x010203 so
                                              // we must mask to get 0x03
    uint32_t byte4 = value & 0xff;            // here we only mask, no shifting
                                              // is necessary
    ...
}

Notice that you could switch the order of the operators above, you could first do the mask, then the shift. The results are the same, but now you would have to use a different mask:

uint32_t byte3 = (value & 0xff00) >> 8;

Access key value from Web.config in Razor View-MVC3 ASP.NET

@System.Configuration.ConfigurationManager.AppSettings["myKey"]

VARCHAR to DECIMAL

In case you need to ROUND the result, not truncate, can use this:

select convert(decimal(38,4), round(convert(decimal(38,10), '123456789.1234567'),4))

This will return the following:

'123456789.1235' for '123456789.1234567'
'123456789.1234' for '123456789.1234467'

Parsing JSON object in PHP using json_decode

You have to make sure first that your server allow remote connection so that the function file_get_contents($url) works fine , most server disable this feature for security reason.

Add a user control to a wpf window

You probably need to add the namespace:

<Window x:Class="UserControlTest.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:UserControlTest"
    Title="User Control Test" Height="300" Width="300">
    <local:UserControl1 />
</Window>

Hidden Features of C#?

Two of my personal favourites, which I see rarely used:

  1. Snippets (particularly for properties, which was made even better for Visual Studio 2008)
  2. The ObsoleteAttribute

-didSelectRowAtIndexPath: not being called

Ok, updating here as I just ran into this problem, and my issue was slightly different than found here.

I looked in IB and saw that my delegate WAS set, but it was set incorrectly to VIEW instead of File's Owner (right click on table view to see where delegate is pointing to).

Hope that helps someone

How to convert JSON string into List of Java object?

use below simple code, no need to use any library

String list = "your_json_string";
Gson gson = new Gson();                         
Type listType = new TypeToken<ArrayList<YourClassObject>>() {}.getType();
ArrayList<YourClassObject> users = new Gson().fromJson(list , listType);

cancelling a handler.postdelayed process

I do this to post a delayed runnable:

myHandler.postDelayed(myRunnable, SPLASH_DISPLAY_LENGTH); 

And this to remove it: myHandler.removeCallbacks(myRunnable);

Setting Short Value Java

In Java, integer literals are of type int by default. For some other types, you may suffix the literal with a case-insensitive letter like L, D, F to specify a long, double, or float, respectively. Note it is common practice to use uppercase letters for better readability.

The Java Language Specification does not provide the same syntactic sugar for byte or short types. Instead, you may declare it as such using explicit casting:

byte foo = (byte)0;
short bar = (short)0;

In your setLongValue(100L) method call, you don't have to necessarily include the L suffix because in this case the int literal is automatically widened to a long. This is called widening primitive conversion in the Java Language Specification.

Return anonymous type results?

You could do something like this:


public System.Collections.IEnumerable GetDogsWithBreedNames()
{
    var db = new DogDataContext(ConnectString);
    var result = from d in db.Dogs
                 join b in db.Breeds on d.BreedId equals b.BreedId
                 select new
                        {
                            Name = d.Name,
                            BreedName = b.BreedName
                        };
    return result.ToList();
}

jquery how to catch enter key and change event to tab

Here is what I've been using:

$("[tabindex]").addClass("TabOnEnter");
$(document).on("keypress", ".TabOnEnter", function (e) {
 //Only do something when the user presses enter
     if (e.keyCode == 13) {
          var nextElement = $('[tabindex="' + (this.tabIndex + 1) + '"]');
          console.log(this, nextElement);
           if (nextElement.length)
                nextElement.focus()
           else
                $('[tabindex="1"]').focus();
      }
});

Pays attention to the tabindex and is not specific to the form but to the whole page.

Note live has been obsoleted by jQuery, now you should be using on

How do I remove repeated elements from ArrayList?

you can use nested loop in follow :

ArrayList<Class1> l1 = new ArrayList<Class1>();
ArrayList<Class1> l2 = new ArrayList<Class1>();

        Iterator iterator1 = l1.iterator();
        boolean repeated = false;

        while (iterator1.hasNext())
        {
            Class1 c1 = (Class1) iterator1.next();
            for (Class1 _c: l2) {
                if(_c.getId() == c1.getId())
                    repeated = true;
            }
            if(!repeated)
                l2.add(c1);
        }

Convert base-2 binary number string to int

Just type 0b11111111 in python interactive interface:

>>> 0b11111111
    255

nginx: send all requests to a single html page

Using just try_files didn't work for me - it caused a rewrite or internal redirection cycle error in my logs.

The Nginx docs had some additional details:

http://nginx.org/en/docs/http/ngx_http_core_module.html#try_files

So I ended up using the following:

root /var/www/mysite;

location / {
    try_files $uri /base.html;
}

location = /base.html {
    expires 30s;
}

Setting up PostgreSQL ODBC on Windows

Installing psqlODBC on 64bit Windows

Though you can install 32 bit ODBC drivers on Win X64 as usual, you can't configure 32-bit DSNs via ordinary control panel or ODBC datasource administrator.

How to configure 32 bit ODBC drivers on Win x64

Configure ODBC DSN from %SystemRoot%\syswow64\odbcad32.exe

  1. Start > Run
  2. Enter: %SystemRoot%\syswow64\odbcad32.exe
  3. Hit return.
  4. Open up ODBC and select under the System DSN tab.
  5. Select PostgreSQL Unicode

You may have to play with it and try different scenarios, think outside-the-box, remember this is open source.

Why should I prefer to use member initialization lists?

Just to add some additional info to demonstrate how much difference the member initialization list can mak. In the leetcode 303 Range Sum Query - Immutable, https://leetcode.com/problems/range-sum-query-immutable/, where you need to construct and initialize to zero a vector with certain size. Here is two different implementation and speed comparison.

Without member initialization list, to get AC it cost me about 212 ms.

class NumArray {
public:
vector<int> preSum;
NumArray(vector<int> nums) {
    preSum = vector<int>(nums.size()+1, 0);
    int ps = 0;
    for (int i = 0; i < nums.size(); i++)
    {
        ps += nums[i];
        preSum[i+1] = ps;
    }
}

int sumRange(int i, int j) {
    return preSum[j+1] - preSum[i];
}
};

Now using member initialization list, the time to get AC is about 108 ms. With this simple example, it is quite obvious that, member initialization list is way more efficient. All the measurement is from the running time from LC.

class NumArray {
public:
vector<int> preSum;
NumArray(vector<int> nums) : preSum(nums.size()+1, 0) { 
    int ps = 0;
    for (int i = 0; i < nums.size(); i++)
    {
        ps += nums[i];
        preSum[i+1] = ps;
    }
}

int sumRange(int i, int j) {
    return preSum[j+1] - preSum[i];
}
};

What's a concise way to check that environment variables are set in a Unix shell script?

Rather than using external shell scripts I tend to load in functions in my login shell. I use something like this as a helper function to check for environment variables rather than any set variable:

is_this_an_env_variable ()
    local var="$1"
    if env |grep -q "^$var"; then
       return 0
    else
       return 1
    fi
 }

Numpy matrix to array

Or you could try to avoid some temps with

A = M.view(np.ndarray)
A.shape = -1

SQL Server Jobs with SSIS packages - Failed to decrypt protected XML node "DTS:Password" with error 0x8009000B

Little late to the game but i found a way to fix this for me that i had not seen anywhere else. Select your connection from Connection Managers. On the right you should see properties. Check to see if there are any expressions there if not add one. In your package explorer add a variable called connection to sql or whatever. Set the variable as a string and set the value as your connection string and include the User Id and password. Back to the connection manager properties and expression. From the drop down select ConnectionString and set the second box as the name of your variable. It should look like this

enter image description here

I could not for the life of me find another solution but this worked!

How to use PrintWriter and File classes in Java?

Well I think firstly keep whole main into try catch(or you can use as public static void main(String arg[]) throws IOException ) and then also use full path of file in which you are writing as

PrintWriter printWriter = new PrintWriter ("C:/Users/Me/Desktop/directory/file.txt");

all those directies like users,Me,Desktop,directory should be user made. java wont make directories own its own. it should be as

import java.io.*;
public class PrintWriterClass {

public static void main(String arg[]) throws IOException{
    PrintWriter pw = new PrintWriter("C:/Users/Me/Desktop/directory/file.txt");
    pw.println("hiiiiiii");
    pw.close();
}   

}

Duplicate ID, tag null, or parent id with another fragment for com.google.android.gms.maps.MapFragment

I had this in viewPager and the crash was because any fragment had to have its own tag, duplicate tags or ids for same fragment are not allowed.

Append values to query string

I've wrapped Darin's answer into a nicely reusable extension method.

public static class UriExtensions
{
    /// <summary>
    /// Adds the specified parameter to the Query String.
    /// </summary>
    /// <param name="url"></param>
    /// <param name="paramName">Name of the parameter to add.</param>
    /// <param name="paramValue">Value for the parameter to add.</param>
    /// <returns>Url with added parameter.</returns>
    public static Uri AddParameter(this Uri url, string paramName, string paramValue)
    {
        var uriBuilder = new UriBuilder(url);
        var query = HttpUtility.ParseQueryString(uriBuilder.Query);
        query[paramName] = paramValue;
        uriBuilder.Query = query.ToString();

        return uriBuilder.Uri;
    }
}

I hope this helps!

"Retrieving the COM class factory for component.... error: 80070005 Access is denied." (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))

This looks like a permission problem. I suggest running processMonitor to determine what permissions are needed.

How do I update Node.js?

Use Node Version Manager (NVM)

It's a Bash script that lets you download and manage different versions of node. Full source code is here.

There is a separate project for nvm for Windows: github.com/coreybutler/nvm-windows

Below are the full steps to use NVM for multiple version of node on windows

  1. download nvm-setup.zip extract and install it.
  2. execute command nvm list available from cmd or gitbash or powershell, this will list all available version of node enter image description here
  3. use command nvm install version e.g. nvm install 12.14.0 to install on the machine
  4. last once installed use nvm use version to use newer version e.g. nvm use 12.14.0

How to merge two json string in Python?

To append key-value pairs to a json string, you can use dict.update: dictA.update(dictB).

For your case, this will look like this:

dictA = json.loads(jsonStringA)
dictB = json.loads('{"error_1395952167":"Error Occured on machine h1 in datacenter dc3 on the step2 of process test"}')

dictA.update(dictB)
jsonStringA = json.dumps(dictA)

Note that key collisions will cause values in dictB overriding dictA.

Get human readable version of file size?

You should use "humanize".

>>> humanize.naturalsize(1000000)
'1.0 MB'
>>> humanize.naturalsize(1000000, binary=True)
'976.6 KiB'
>>> humanize.naturalsize(1000000, gnu=True)
'976.6K'

Reference:

https://pypi.org/project/humanize/

Passing $_POST values with cURL

Another simple PHP example of using cURL:

<?php
    $ch = curl_init();                    // Initiate cURL
    $url = "http://www.somesite.com/curl_example.php"; // Where you want to post data
    curl_setopt($ch, CURLOPT_URL,$url);
    curl_setopt($ch, CURLOPT_POST, true);  // Tell cURL you want to post something
    curl_setopt($ch, CURLOPT_POSTFIELDS, "var1=value1&var2=value2&var_n=value_n"); // Define what you want to post
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); // Return the output in string format
    $output = curl_exec ($ch); // Execute

    curl_close ($ch); // Close cURL handle

    var_dump($output); // Show output
?>

Example found here: http://devzone.co.in/post-data-using-curl-in-php-a-simple-example/

Instead of using curl_setopt you can use curl_setopt_array.

http://php.net/manual/en/function.curl-setopt-array.php

How to use setArguments() and getArguments() methods in Fragments?

If you are using navigation components and navigation graph create a bundle like this

val bundle = bundleOf(KEY to VALUE) // or whatever you would like to create the bundle

then when navigating to the other fragment use this:

findNavController().navigate(
        R.id.action_navigate_from_frag1_to_frag2,
        bundle
    )

and when you land the destination fragment u can access that bundle using

Bundle b = getArguments()// in Java

or

val b = arguments// in kotlin

An error occurred while signing: SignTool.exe not found

Please Click Once application --> Properties --> Signing -> Unchecked the Sign the ClickOnce manifests.

Problem will be solved.

Note: Be aware that this solution removes security from your project. Seek assitance from a more learned colleague before doing so.

Jump to function definition in vim

Another common technique is to place the function name in the first column. This allows the definition to be found with a simple search.

int
main(int argc, char *argv[])
{
    ...
}

The above function could then be found with /^main inside the file or with :grep -r '^main' *.c in a directory. As long as code is properly indented the only time the identifier will occur at the beginning of a line is at the function definition.

Of course, if you aren't using ctags from this point on you should be ashamed of yourself! However, I find this coding standard a helpful addition as well.

ViewPager and fragments — what's the right way to store fragment's state?

A bit different opinion instead of storing the Fragments yourself just leave it to the FragmentManager and when you need to do something with the fragments look for them in the FragmentManager:

//make sure you have the right FragmentManager 
//getSupportFragmentManager or getChildFragmentManager depending on what you are using to manage this stack of fragments
List<Fragment> fragments = fragmentManager.getFragments();
if(fragments != null) {
   int count = fragments.size();
   for (int x = 0; x < count; x++) {
       Fragment fragment = fragments.get(x);
       //check if this is the fragment we want, 
       //it may be some other inspection, tag etc.
       if (fragment instanceof MyFragment) {
           //do whatever we need to do with it
       }
   }
}

If you have a lot of Fragments and the cost of instanceof check may be not what you want, but it is good thing to have in mind that the FragmentManager already keeps account of Fragments.

Set div height equal to screen size

try this

$(document).ready(function(){
    $('#content').height($(window).height());
});

incompatible character encodings: ASCII-8BIT and UTF-8

Try to find the exact line which causing this problem and then enforce UTF8 coding, this solution worked for me.

title.to_s.force_encoding("UTF-8")

ASP.NET MVC: What is the purpose of @section?

A good example is Javascript. You want this to be at the bottom of the page that is rendered in the browser because this is best practice.

How would you do this from a View based on a Layout/Masterpage where you can only access the middle of the page?

You do this by declaring a Scripts section at the bottom of the Layout page. Then you can add content, in this case Javascript includes (I hope!), from your View page to the bottom of your layout page.

How do I get an apk file from an Android device?

All these answers require multiple steps for each apk file retrieved from the device. 1. determine package name, 2. find the file, and 3. download it. I built a simple apk_grabber python script to do this for any app that matches a given regex, and then decompiles those apks into jar files.

Delete all local git branches

The below command will delete all the local branches except master branch.

git branch | grep -v "master" | xargs git branch -D

The above command

  1. list all the branches
  2. From the list ignore the master branch and take the rest of the branches
  3. delete the branch

grep for special characters in Unix

Try vi with the -b option, this will show special end of line characters (I typically use it to see windows line endings in a txt file on a unix OS)

But if you want a scripted solution obviously vi wont work so you can try the -f or -e options with grep and pipe the result into sed or awk. From grep man page:

Matcher Selection -E, --extended-regexp Interpret PATTERN as an extended regular expression (ERE, see below). (-E is specified by POSIX.)

   -F, --fixed-strings
          Interpret PATTERN as a list of fixed strings, separated by newlines, any of which is to be matched.  (-F is specified
          by POSIX.)

java.io.IOException: Could not locate executable null\bin\winutils.exe in the Hadoop binaries. spark Eclipse on windows 7

Here is a good explanation of your problem with the solution.

  1. Download winutils.exe from http://public-repo-1.hortonworks.com/hdp-win-alpha/winutils.exe.
  2. SetUp your HADOOP_HOME environment variable on the OS level or programmatically:

    System.setProperty("hadoop.home.dir", "full path to the folder with winutils");

  3. Enjoy

jQuery move to anchor location on page load

Description

You can do this using jQuery's .scrollTop() and .offset() method

Check out my sample and this jsFiddle Demonstration

Sample

$(function() {
    $(document).scrollTop( $("#header").offset().top );  
});

More Information

"Unknown class <MyClass> in Interface Builder file" error at runtime

I added the file Under Build Phase in Targets and the issue got resolved. For the steps to add the file, see my answer at:

Apple Mach-O Linker error (APActivityIcon)

Python NameError: name is not defined

Note that sometimes you will want to use the class type name inside its own definition, for example when using Python Typing module, e.g.

class Tree:
    def __init__(self, left: Tree, right: Tree):
        self.left = left
        self.right = right

This will also result in

NameError: name 'Tree' is not defined

That's because the class has not been defined yet at this point. The workaround is using so called Forward Reference, i.e. wrapping a class name in a string, i.e.

class Tree:
    def __init__(self, left: 'Tree', right: 'Tree'):
        self.left = left
        self.right = right

How to start new activity on button click

Take Button in xml first.

  <Button
        android:id="@+id/pre"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@mipmap/ic_launcher"
        android:text="Your Text"
        />

Make listner of button.

 pre.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(MainActivity.this, SecondActivity.class);
            startActivity(intent);
        }
    });

Change the background color in a twitter bootstrap modal?

For Bootstrap 4 you may have to use .modal-backdrop.show and play around with !important flag on both background-color and opacity.

E.g.

.modal-backdrop.show {
   background-color: #f00;
   opacity: 0.75;
}

How to add a margin to a table row <tr>

You can't style the <tr>s themselves, but you can give the <td>s inside the "highlight" <tr>s a style, like this

tr.highlight td {padding-top: 10px; padding-bottom:10px}

How do you set, clear, and toggle a single bit?

A templated version (put in a header file) with support for changing multiple bits (works on AVR microcontrollers btw):

namespace bit {
  template <typename T1, typename T2>
  constexpr inline T1 bitmask(T2 bit) 
  {return (T1)1 << bit;}
  template <typename T1, typename T3, typename ...T2>
  constexpr inline T1 bitmask(T3 bit, T2 ...bits) 
  {return ((T1)1 << bit) | bitmask<T1>(bits...);}

  /** Set these bits (others retain their state) */
  template <typename T1, typename ...T2>
  constexpr inline void set (T1 &variable, T2 ...bits) 
  {variable |= bitmask<T1>(bits...);}
  /** Set only these bits (others will be cleared) */
  template <typename T1, typename ...T2>
  constexpr inline void setOnly (T1 &variable, T2 ...bits) 
  {variable = bitmask<T1>(bits...);}
  /** Clear these bits (others retain their state) */
  template <typename T1, typename ...T2>
  constexpr inline void clear (T1 &variable, T2 ...bits) 
  {variable &= ~bitmask<T1>(bits...);}
  /** Flip these bits (others retain their state) */
  template <typename T1, typename ...T2>
  constexpr inline void flip (T1 &variable, T2 ...bits) 
  {variable ^= bitmask<T1>(bits...);}
  /** Check if any of these bits are set */
  template <typename T1, typename ...T2>
  constexpr inline bool isAnySet(const T1 &variable, T2 ...bits) 
  {return variable & bitmask<T1>(bits...);}
  /** Check if all these bits are set */
  template <typename T1, typename ...T2>
  constexpr inline bool isSet (const T1 &variable, T2 ...bits) 
  {return ((variable & bitmask<T1>(bits...)) == bitmask<T1>(bits...));}
  /** Check if all these bits are not set */
  template <typename T1, typename ...T2>
  constexpr inline bool isNotSet (const T1 &variable, T2 ...bits) 
  {return ((variable & bitmask<T1>(bits...)) != bitmask<T1>(bits...));}
}

Example of use:

#include <iostream>
#include <bitset> // for console output of binary values

// and include the code above of course

using namespace std;

int main() {
  uint8_t v = 0b1111'1100;
  bit::set(v, 0);
  cout << bitset<8>(v) << endl;

  bit::clear(v, 0,1);
  cout << bitset<8>(v) << endl;

  bit::flip(v, 0,1);
  cout << bitset<8>(v) << endl;

  bit::clear(v, 0,1,2,3,4,5,6,7);
  cout << bitset<8>(v) << endl;

  bit::flip(v, 0,7);
  cout << bitset<8>(v) << endl;
}

BTW: It turns out that constexpr and inline is not used if not sending the optimizer argument (e.g.: -O3) to the compiler. Feel free to try the code at https://godbolt.org/ and look at the ASM output.

How to access a mobile's camera from a web app?

Just to update this, the standard now is:

<input type="file" name="image" accept="image/*" capture="environment">

to access the environment-facing (rear) camera, and

<input type="file" name="image" accept="image/*" capture="user">

for user-facing (front) camera. To access video, substitute "video" for "image" in name.

Tested on iPhone 5c, running iOS 10.3.3, firmware 760, works fine.

https://www.w3.org/TR/html-media-capture/

Trying to get property of non-object - Laravel 5

If you working with or loops (for, foreach, etc.) or relationships (one to many, many to many, etc.), this may mean that one of the queries is returning a null variable or a null relationship member.

For example: In a table, you may want to list users with their roles.

<table>
    <tr>
        <th>Name</th>
        <th>Role</th>
    </tr>
    @foreach ($users as $user)
    <tr>
        <td>{{ $user->name }}</td>
        <td>{{ $user->role->name }}</td>
    </tr>
    @endforeach
</table>

In the above case, you may receive this error if there is even one User who does not have a Role. You should replace {{ $user->role->name }} with {{ !empty($user->role) ? $user->role->name:'' }}, like this:

<table>
    <tr>
        <th>Name</th>
        <th>Role</th>
    </tr>
    @foreach ($users as $user)
    <tr>
        <td>{{ $user->name }}</td>
        <td>{{ !empty($user->role) ? $user->role->name:'' }}</td>
    </tr>
    @endforeach
</table>

Edit: You can use Laravel's the optional method to avoid errors (more information). For example:

<table>
    <tr>
        <th>Name</th>
        <th>Role</th>
    </tr>
    @foreach ($users as $user)
    <tr>
        <td>{{ $user->name }}</td>
        <td>{{ optional($user->role)->name }}</td>
    </tr>
    @endforeach
</table>

If you are using PHP 8, you can use the null safe operator:

<table>
    <tr>
        <th>Name</th>
        <th>Role</th>
    </tr>
    @foreach ($users as $user)
    <tr>
        <td>{{ $user?->name }}</td>
        <td>{{ $user?->role?->name }}</td>
    </tr>
    @endforeach
</table>

How do I create the small icon next to the website tab for my site?

It is called favicon.ico and you can generate it from this site.

http://www.favicon.cc/

How to determine programmatically the current active profile using Spring boot

It doesn't matter is your app Boot or just raw Spring. There is just enough to inject org.springframework.core.env.Environment to your bean.

@Autowired
private Environment environment;
....

this.environment.getActiveProfiles();

Div Background Image Z-Index Issue

For z-index to work, you also need to give it a position:

header {
    width: 100%;
    height: 100px;
    background: url(../img/top.png) repeat-x;
    z-index: 110;
    position: relative;
}

Regex in JavaScript for validating decimal numbers

Numbers with at most 2 decimal places:

/^\d+(?:\.\d{1,2})?$/

This should work fine. Please try out :)

How to Navigate from one View Controller to another using Swift

SWIFT 3.01

let secondViewController = self.storyboard?.instantiateViewController(withIdentifier: "Conversation_VC") as! Conversation_VC
self.navigationController?.pushViewController(secondViewController, animated: true)

How can I check MySQL engine type for a specific table?

SHOW CREATE TABLE <tablename>\G

will format it much nicer compared to the output of

SHOW CREATE TABLE <tablename>;

The \G trick is also useful to remember for many other queries/commands.

How to convert a Kotlin source file to a Java source file

  1. open kotlin file in android studio
  2. go to tools -> kotlin ->kotlin bytecode
  3. in the new window that open beside your kotlin file , click the decompile button . it will create java equivalent of your kotlin file .

bootstrap button shows blue outline when clicked

Try the below

.bootstrap-select .dropdown-toggle:focus 
 {
          outline: 0 !important;
 }

Editing the date formatting of x-axis tick labels in matplotlib

From the package matplotlib.dates as shown in this example the date format can be applied to the axis label and ticks for plot.

Below I have given an example for labeling axis ticks for multiplots

import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import pandas as pd

df = pd.read_csv('US_temp.csv')
plt.plot(df['Date'],df_f['MINT'],label='Min Temp.')
plt.plot(df['Date'],df_f['MAXT'],label='Max Temp.')
plt.legend()
####### Use the below functions #######
dtFmt = mdates.DateFormatter('%b') # define the formatting
plt.gca().xaxis.set_major_formatter(dtFmt) # apply the format to the desired axis
plt.show()

As simple as that

When is the init() function run?

Take for example a framework or a library you're designing for other users, these users eventually will have a main function in their code in order to execute their app. If the user directly imports a sub-package of your library's project then the init of that sub-package will be called(once) first of all. The same for the root package of the library, etc...

There are many times when you may want a code block to be executed without the existence of a main func, directly or not.

If you, as the developer of the imaginary library, import your library's sub-package that has an init function, it will be called first and once, you don't have a main func but you need to make sure that some variables, or a table, will be initialized before the calls of other functions.

A good thing to remember and not to worry about, is that: the init always execute once per application.

init execution happens:

  1. right before the init function of the "caller" package,
  2. before the, optionally, main func,
  3. but after the package-level variables, var = [...] or cost = [...],

When you import a package it will run all of its init functions, by order.

I'll will give a very good example of an init function. It will add mime types to a standard go's library named mime and a package-level function will use the mime standard package directly to get the custom mime types that are already be initialized at its init function:

package mime

import (
    "mime"
    "path/filepath"
)

var types = map[string]string{
    ".3dm":       "x-world/x-3dmf",
    ".3dmf":      "x-world/x-3dmf",
    ".7z":        "application/x-7z-compressed",
    ".a":         "application/octet-stream",
    ".aab":       "application/x-authorware-bin",
    ".aam":       "application/x-authorware-map",
    ".aas":       "application/x-authorware-seg",
    ".abc":       "text/vndabc",
    ".ace":       "application/x-ace-compressed",
    ".acgi":      "text/html",
    ".afl":       "video/animaflex",
    ".ai":        "application/postscript",
    ".aif":       "audio/aiff",
    ".aifc":      "audio/aiff",
    ".aiff":      "audio/aiff",
    ".aim":       "application/x-aim",
    ".aip":       "text/x-audiosoft-intra",
    ".alz":       "application/x-alz-compressed",
    ".ani":       "application/x-navi-animation",
    ".aos":       "application/x-nokia-9000-communicator-add-on-software",
    ".aps":       "application/mime",
    ".apk":       "application/vnd.android.package-archive",
    ".arc":       "application/x-arc-compressed",
    ".arj":       "application/arj",
    ".art":       "image/x-jg",
    ".asf":       "video/x-ms-asf",
    ".asm":       "text/x-asm",
    ".asp":       "text/asp",
    ".asx":       "application/x-mplayer2",
    ".au":        "audio/basic",
    ".avi":       "video/x-msvideo",
    ".avs":       "video/avs-video",
    ".bcpio":     "application/x-bcpio",
    ".bin":       "application/mac-binary",
    ".bmp":       "image/bmp",
    ".boo":       "application/book",
    ".book":      "application/book",
    ".boz":       "application/x-bzip2",
    ".bsh":       "application/x-bsh",
    ".bz2":       "application/x-bzip2",
    ".bz":        "application/x-bzip",
    ".c++":       "text/plain",
    ".c":         "text/x-c",
    ".cab":       "application/vnd.ms-cab-compressed",
    ".cat":       "application/vndms-pkiseccat",
    ".cc":        "text/x-c",
    ".ccad":      "application/clariscad",
    ".cco":       "application/x-cocoa",
    ".cdf":       "application/cdf",
    ".cer":       "application/pkix-cert",
    ".cha":       "application/x-chat",
    ".chat":      "application/x-chat",
    ".chrt":      "application/vnd.kde.kchart",
    ".class":     "application/java",
    ".com":       "text/plain",
    ".conf":      "text/plain",
    ".cpio":      "application/x-cpio",
    ".cpp":       "text/x-c",
    ".cpt":       "application/mac-compactpro",
    ".crl":       "application/pkcs-crl",
    ".crt":       "application/pkix-cert",
    ".crx":       "application/x-chrome-extension",
    ".csh":       "text/x-scriptcsh",
    ".css":       "text/css",
    ".csv":       "text/csv",
    ".cxx":       "text/plain",
    ".dar":       "application/x-dar",
    ".dcr":       "application/x-director",
    ".deb":       "application/x-debian-package",
    ".deepv":     "application/x-deepv",
    ".def":       "text/plain",
    ".der":       "application/x-x509-ca-cert",
    ".dif":       "video/x-dv",
    ".dir":       "application/x-director",
    ".divx":      "video/divx",
    ".dl":        "video/dl",
    ".dmg":       "application/x-apple-diskimage",
    ".doc":       "application/msword",
    ".dot":       "application/msword",
    ".dp":        "application/commonground",
    ".drw":       "application/drafting",
    ".dump":      "application/octet-stream",
    ".dv":        "video/x-dv",
    ".dvi":       "application/x-dvi",
    ".dwf":       "drawing/x-dwf=(old)",
    ".dwg":       "application/acad",
    ".dxf":       "application/dxf",
    ".dxr":       "application/x-director",
    ".el":        "text/x-scriptelisp",
    ".elc":       "application/x-bytecodeelisp=(compiled=elisp)",
    ".eml":       "message/rfc822",
    ".env":       "application/x-envoy",
    ".eps":       "application/postscript",
    ".es":        "application/x-esrehber",
    ".etx":       "text/x-setext",
    ".evy":       "application/envoy",
    ".exe":       "application/octet-stream",
    ".f77":       "text/x-fortran",
    ".f90":       "text/x-fortran",
    ".f":         "text/x-fortran",
    ".fdf":       "application/vndfdf",
    ".fif":       "application/fractals",
    ".fli":       "video/fli",
    ".flo":       "image/florian",
    ".flv":       "video/x-flv",
    ".flx":       "text/vndfmiflexstor",
    ".fmf":       "video/x-atomic3d-feature",
    ".for":       "text/x-fortran",
    ".fpx":       "image/vndfpx",
    ".frl":       "application/freeloader",
    ".funk":      "audio/make",
    ".g3":        "image/g3fax",
    ".g":         "text/plain",
    ".gif":       "image/gif",
    ".gl":        "video/gl",
    ".gsd":       "audio/x-gsm",
    ".gsm":       "audio/x-gsm",
    ".gsp":       "application/x-gsp",
    ".gss":       "application/x-gss",
    ".gtar":      "application/x-gtar",
    ".gz":        "application/x-compressed",
    ".gzip":      "application/x-gzip",
    ".h":         "text/x-h",
    ".hdf":       "application/x-hdf",
    ".help":      "application/x-helpfile",
    ".hgl":       "application/vndhp-hpgl",
    ".hh":        "text/x-h",
    ".hlb":       "text/x-script",
    ".hlp":       "application/hlp",
    ".hpg":       "application/vndhp-hpgl",
    ".hpgl":      "application/vndhp-hpgl",
    ".hqx":       "application/binhex",
    ".hta":       "application/hta",
    ".htc":       "text/x-component",
    ".htm":       "text/html",
    ".html":      "text/html",
    ".htmls":     "text/html",
    ".htt":       "text/webviewhtml",
    ".htx":       "text/html",
    ".ice":       "x-conference/x-cooltalk",
    ".ico":       "image/x-icon",
    ".ics":       "text/calendar",
    ".icz":       "text/calendar",
    ".idc":       "text/plain",
    ".ief":       "image/ief",
    ".iefs":      "image/ief",
    ".iges":      "application/iges",
    ".igs":       "application/iges",
    ".ima":       "application/x-ima",
    ".imap":      "application/x-httpd-imap",
    ".inf":       "application/inf",
    ".ins":       "application/x-internett-signup",
    ".ip":        "application/x-ip2",
    ".isu":       "video/x-isvideo",
    ".it":        "audio/it",
    ".iv":        "application/x-inventor",
    ".ivr":       "i-world/i-vrml",
    ".ivy":       "application/x-livescreen",
    ".jam":       "audio/x-jam",
    ".jav":       "text/x-java-source",
    ".java":      "text/x-java-source",
    ".jcm":       "application/x-java-commerce",
    ".jfif-tbnl": "image/jpeg",
    ".jfif":      "image/jpeg",
    ".jnlp":      "application/x-java-jnlp-file",
    ".jpe":       "image/jpeg",
    ".jpeg":      "image/jpeg",
    ".jpg":       "image/jpeg",
    ".jps":       "image/x-jps",
    ".js":        "application/javascript",
    ".json":      "application/json",
    ".jut":       "image/jutvision",
    ".kar":       "audio/midi",
    ".karbon":    "application/vnd.kde.karbon",
    ".kfo":       "application/vnd.kde.kformula",
    ".flw":       "application/vnd.kde.kivio",
    ".kml":       "application/vnd.google-earth.kml+xml",
    ".kmz":       "application/vnd.google-earth.kmz",
    ".kon":       "application/vnd.kde.kontour",
    ".kpr":       "application/vnd.kde.kpresenter",
    ".kpt":       "application/vnd.kde.kpresenter",
    ".ksp":       "application/vnd.kde.kspread",
    ".kwd":       "application/vnd.kde.kword",
    ".kwt":       "application/vnd.kde.kword",
    ".ksh":       "text/x-scriptksh",
    ".la":        "audio/nspaudio",
    ".lam":       "audio/x-liveaudio",
    ".latex":     "application/x-latex",
    ".lha":       "application/lha",
    ".lhx":       "application/octet-stream",
    ".list":      "text/plain",
    ".lma":       "audio/nspaudio",
    ".log":       "text/plain",
    ".lsp":       "text/x-scriptlisp",
    ".lst":       "text/plain",
    ".lsx":       "text/x-la-asf",
    ".ltx":       "application/x-latex",
    ".lzh":       "application/octet-stream",
    ".lzx":       "application/lzx",
    ".m1v":       "video/mpeg",
    ".m2a":       "audio/mpeg",
    ".m2v":       "video/mpeg",
    ".m3u":       "audio/x-mpegurl",
    ".m":         "text/x-m",
    ".man":       "application/x-troff-man",
    ".manifest":  "text/cache-manifest",
    ".map":       "application/x-navimap",
    ".mar":       "text/plain",
    ".mbd":       "application/mbedlet",
    ".mc$":       "application/x-magic-cap-package-10",
    ".mcd":       "application/mcad",
    ".mcf":       "text/mcf",
    ".mcp":       "application/netmc",
    ".me":        "application/x-troff-me",
    ".mht":       "message/rfc822",
    ".mhtml":     "message/rfc822",
    ".mid":       "application/x-midi",
    ".midi":      "application/x-midi",
    ".mif":       "application/x-frame",
    ".mime":      "message/rfc822",
    ".mjf":       "audio/x-vndaudioexplosionmjuicemediafile",
    ".mjpg":      "video/x-motion-jpeg",
    ".mm":        "application/base64",
    ".mme":       "application/base64",
    ".mod":       "audio/mod",
    ".moov":      "video/quicktime",
    ".mov":       "video/quicktime",
    ".movie":     "video/x-sgi-movie",
    ".mp2":       "audio/mpeg",
    ".mp3":       "audio/mpeg3",
    ".mp4":       "video/mp4",
    ".mpa":       "audio/mpeg",
    ".mpc":       "application/x-project",
    ".mpe":       "video/mpeg",
    ".mpeg":      "video/mpeg",
    ".mpg":       "video/mpeg",
    ".mpga":      "audio/mpeg",
    ".mpp":       "application/vndms-project",
    ".mpt":       "application/x-project",
    ".mpv":       "application/x-project",
    ".mpx":       "application/x-project",
    ".mrc":       "application/marc",
    ".ms":        "application/x-troff-ms",
    ".mv":        "video/x-sgi-movie",
    ".my":        "audio/make",
    ".mzz":       "application/x-vndaudioexplosionmzz",
    ".nap":       "image/naplps",
    ".naplps":    "image/naplps",
    ".nc":        "application/x-netcdf",
    ".ncm":       "application/vndnokiaconfiguration-message",
    ".nif":       "image/x-niff",
    ".niff":      "image/x-niff",
    ".nix":       "application/x-mix-transfer",
    ".nsc":       "application/x-conference",
    ".nvd":       "application/x-navidoc",
    ".o":         "application/octet-stream",
    ".oda":       "application/oda",
    ".odb":       "application/vnd.oasis.opendocument.database",
    ".odc":       "application/vnd.oasis.opendocument.chart",
    ".odf":       "application/vnd.oasis.opendocument.formula",
    ".odg":       "application/vnd.oasis.opendocument.graphics",
    ".odi":       "application/vnd.oasis.opendocument.image",
    ".odm":       "application/vnd.oasis.opendocument.text-master",
    ".odp":       "application/vnd.oasis.opendocument.presentation",
    ".ods":       "application/vnd.oasis.opendocument.spreadsheet",
    ".odt":       "application/vnd.oasis.opendocument.text",
    ".oga":       "audio/ogg",
    ".ogg":       "audio/ogg",
    ".ogv":       "video/ogg",
    ".omc":       "application/x-omc",
    ".omcd":      "application/x-omcdatamaker",
    ".omcr":      "application/x-omcregerator",
    ".otc":       "application/vnd.oasis.opendocument.chart-template",
    ".otf":       "application/vnd.oasis.opendocument.formula-template",
    ".otg":       "application/vnd.oasis.opendocument.graphics-template",
    ".oth":       "application/vnd.oasis.opendocument.text-web",
    ".oti":       "application/vnd.oasis.opendocument.image-template",
    ".otm":       "application/vnd.oasis.opendocument.text-master",
    ".otp":       "application/vnd.oasis.opendocument.presentation-template",
    ".ots":       "application/vnd.oasis.opendocument.spreadsheet-template",
    ".ott":       "application/vnd.oasis.opendocument.text-template",
    ".p10":       "application/pkcs10",
    ".p12":       "application/pkcs-12",
    ".p7a":       "application/x-pkcs7-signature",
    ".p7c":       "application/pkcs7-mime",
    ".p7m":       "application/pkcs7-mime",
    ".p7r":       "application/x-pkcs7-certreqresp",
    ".p7s":       "application/pkcs7-signature",
    ".p":         "text/x-pascal",
    ".part":      "application/pro_eng",
    ".pas":       "text/pascal",
    ".pbm":       "image/x-portable-bitmap",
    ".pcl":       "application/vndhp-pcl",
    ".pct":       "image/x-pict",
    ".pcx":       "image/x-pcx",
    ".pdb":       "chemical/x-pdb",
    ".pdf":       "application/pdf",
    ".pfunk":     "audio/make",
    ".pgm":       "image/x-portable-graymap",
    ".pic":       "image/pict",
    ".pict":      "image/pict",
    ".pkg":       "application/x-newton-compatible-pkg",
    ".pko":       "application/vndms-pkipko",
    ".pl":        "text/x-scriptperl",
    ".plx":       "application/x-pixclscript",
    ".pm4":       "application/x-pagemaker",
    ".pm5":       "application/x-pagemaker",
    ".pm":        "text/x-scriptperl-module",
    ".png":       "image/png",
    ".pnm":       "application/x-portable-anymap",
    ".pot":       "application/mspowerpoint",
    ".pov":       "model/x-pov",
    ".ppa":       "application/vndms-powerpoint",
    ".ppm":       "image/x-portable-pixmap",
    ".pps":       "application/mspowerpoint",
    ".ppt":       "application/mspowerpoint",
    ".ppz":       "application/mspowerpoint",
    ".pre":       "application/x-freelance",
    ".prt":       "application/pro_eng",
    ".ps":        "application/postscript",
    ".psd":       "application/octet-stream",
    ".pvu":       "paleovu/x-pv",
    ".pwz":       "application/vndms-powerpoint",
    ".py":        "text/x-scriptphyton",
    ".pyc":       "application/x-bytecodepython",
    ".qcp":       "audio/vndqcelp",
    ".qd3":       "x-world/x-3dmf",
    ".qd3d":      "x-world/x-3dmf",
    ".qif":       "image/x-quicktime",
    ".qt":        "video/quicktime",
    ".qtc":       "video/x-qtc",
    ".qti":       "image/x-quicktime",
    ".qtif":      "image/x-quicktime",
    ".ra":        "audio/x-pn-realaudio",
    ".ram":       "audio/x-pn-realaudio",
    ".rar":       "application/x-rar-compressed",
    ".ras":       "application/x-cmu-raster",
    ".rast":      "image/cmu-raster",
    ".rexx":      "text/x-scriptrexx",
    ".rf":        "image/vndrn-realflash",
    ".rgb":       "image/x-rgb",
    ".rm":        "application/vndrn-realmedia",
    ".rmi":       "audio/mid",
    ".rmm":       "audio/x-pn-realaudio",
    ".rmp":       "audio/x-pn-realaudio",
    ".rng":       "application/ringing-tones",
    ".rnx":       "application/vndrn-realplayer",
    ".roff":      "application/x-troff",
    ".rp":        "image/vndrn-realpix",
    ".rpm":       "audio/x-pn-realaudio-plugin",
    ".rt":        "text/vndrn-realtext",
    ".rtf":       "text/richtext",
    ".rtx":       "text/richtext",
    ".rv":        "video/vndrn-realvideo",
    ".s":         "text/x-asm",
    ".s3m":       "audio/s3m",
    ".s7z":       "application/x-7z-compressed",
    ".saveme":    "application/octet-stream",
    ".sbk":       "application/x-tbook",
    ".scm":       "text/x-scriptscheme",
    ".sdml":      "text/plain",
    ".sdp":       "application/sdp",
    ".sdr":       "application/sounder",
    ".sea":       "application/sea",
    ".set":       "application/set",
    ".sgm":       "text/x-sgml",
    ".sgml":      "text/x-sgml",
    ".sh":        "text/x-scriptsh",
    ".shar":      "application/x-bsh",
    ".shtml":     "text/x-server-parsed-html",
    ".sid":       "audio/x-psid",
    ".skd":       "application/x-koan",
    ".skm":       "application/x-koan",
    ".skp":       "application/x-koan",
    ".skt":       "application/x-koan",
    ".sit":       "application/x-stuffit",
    ".sitx":      "application/x-stuffitx",
    ".sl":        "application/x-seelogo",
    ".smi":       "application/smil",
    ".smil":      "application/smil",
    ".snd":       "audio/basic",
    ".sol":       "application/solids",
    ".spc":       "text/x-speech",
    ".spl":       "application/futuresplash",
    ".spr":       "application/x-sprite",
    ".sprite":    "application/x-sprite",
    ".spx":       "audio/ogg",
    ".src":       "application/x-wais-source",
    ".ssi":       "text/x-server-parsed-html",
    ".ssm":       "application/streamingmedia",
    ".sst":       "application/vndms-pkicertstore",
    ".step":      "application/step",
    ".stl":       "application/sla",
    ".stp":       "application/step",
    ".sv4cpio":   "application/x-sv4cpio",
    ".sv4crc":    "application/x-sv4crc",
    ".svf":       "image/vnddwg",
    ".svg":       "image/svg+xml",
    ".svr":       "application/x-world",
    ".swf":       "application/x-shockwave-flash",
    ".t":         "application/x-troff",
    ".talk":      "text/x-speech",
    ".tar":       "application/x-tar",
    ".tbk":       "application/toolbook",
    ".tcl":       "text/x-scripttcl",
    ".tcsh":      "text/x-scripttcsh",
    ".tex":       "application/x-tex",
    ".texi":      "application/x-texinfo",
    ".texinfo":   "application/x-texinfo",
    ".text":      "text/plain",
    ".tgz":       "application/gnutar",
    ".tif":       "image/tiff",
    ".tiff":      "image/tiff",
    ".tr":        "application/x-troff",
    ".tsi":       "audio/tsp-audio",
    ".tsp":       "application/dsptype",
    ".tsv":       "text/tab-separated-values",
    ".turbot":    "image/florian",
    ".txt":       "text/plain",
    ".uil":       "text/x-uil",
    ".uni":       "text/uri-list",
    ".unis":      "text/uri-list",
    ".unv":       "application/i-deas",
    ".uri":       "text/uri-list",
    ".uris":      "text/uri-list",
    ".ustar":     "application/x-ustar",
    ".uu":        "text/x-uuencode",
    ".uue":       "text/x-uuencode",
    ".vcd":       "application/x-cdlink",
    ".vcf":       "text/x-vcard",
    ".vcard":     "text/x-vcard",
    ".vcs":       "text/x-vcalendar",
    ".vda":       "application/vda",
    ".vdo":       "video/vdo",
    ".vew":       "application/groupwise",
    ".viv":       "video/vivo",
    ".vivo":      "video/vivo",
    ".vmd":       "application/vocaltec-media-desc",
    ".vmf":       "application/vocaltec-media-file",
    ".voc":       "audio/voc",
    ".vos":       "video/vosaic",
    ".vox":       "audio/voxware",
    ".vqe":       "audio/x-twinvq-plugin",
    ".vqf":       "audio/x-twinvq",
    ".vql":       "audio/x-twinvq-plugin",
    ".vrml":      "application/x-vrml",
    ".vrt":       "x-world/x-vrt",
    ".vsd":       "application/x-visio",
    ".vst":       "application/x-visio",
    ".vsw":       "application/x-visio",
    ".w60":       "application/wordperfect60",
    ".w61":       "application/wordperfect61",
    ".w6w":       "application/msword",
    ".wav":       "audio/wav",
    ".wb1":       "application/x-qpro",
    ".wbmp":      "image/vnd.wap.wbmp",
    ".web":       "application/vndxara",
    ".wiz":       "application/msword",
    ".wk1":       "application/x-123",
    ".wmf":       "windows/metafile",
    ".wml":       "text/vnd.wap.wml",
    ".wmlc":      "application/vnd.wap.wmlc",
    ".wmls":      "text/vnd.wap.wmlscript",
    ".wmlsc":     "application/vnd.wap.wmlscriptc",
    ".word":      "application/msword",
    ".wp5":       "application/wordperfect",
    ".wp6":       "application/wordperfect",
    ".wp":        "application/wordperfect",
    ".wpd":       "application/wordperfect",
    ".wq1":       "application/x-lotus",
    ".wri":       "application/mswrite",
    ".wrl":       "application/x-world",
    ".wrz":       "model/vrml",
    ".wsc":       "text/scriplet",
    ".wsrc":      "application/x-wais-source",
    ".wtk":       "application/x-wintalk",
    ".x-png":     "image/png",
    ".xbm":       "image/x-xbitmap",
    ".xdr":       "video/x-amt-demorun",
    ".xgz":       "xgl/drawing",
    ".xif":       "image/vndxiff",
    ".xl":        "application/excel",
    ".xla":       "application/excel",
    ".xlb":       "application/excel",
    ".xlc":       "application/excel",
    ".xld":       "application/excel",
    ".xlk":       "application/excel",
    ".xll":       "application/excel",
    ".xlm":       "application/excel",
    ".xls":       "application/excel",
    ".xlt":       "application/excel",
    ".xlv":       "application/excel",
    ".xlw":       "application/excel",
    ".xm":        "audio/xm",
    ".xml":       "text/xml",
    ".xmz":       "xgl/movie",
    ".xpix":      "application/x-vndls-xpix",
    ".xpm":       "image/x-xpixmap",
    ".xsr":       "video/x-amt-showrun",
    ".xwd":       "image/x-xwd",
    ".xyz":       "chemical/x-pdb",
    ".z":         "application/x-compress",
    ".zip":       "application/zip",
    ".zoo":       "application/octet-stream",
    ".zsh":       "text/x-scriptzsh",
    ".docx":      "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
    ".docm":      "application/vnd.ms-word.document.macroEnabled.12",
    ".dotx":      "application/vnd.openxmlformats-officedocument.wordprocessingml.template",
    ".dotm":      "application/vnd.ms-word.template.macroEnabled.12",
    ".xlsx":      "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
    ".xlsm":      "application/vnd.ms-excel.sheet.macroEnabled.12",
    ".xltx":      "application/vnd.openxmlformats-officedocument.spreadsheetml.template",
    ".xltm":      "application/vnd.ms-excel.template.macroEnabled.12",
    ".xlsb":      "application/vnd.ms-excel.sheet.binary.macroEnabled.12",
    ".xlam":      "application/vnd.ms-excel.addin.macroEnabled.12",
    ".pptx":      "application/vnd.openxmlformats-officedocument.presentationml.presentation",
    ".pptm":      "application/vnd.ms-powerpoint.presentation.macroEnabled.12",
    ".ppsx":      "application/vnd.openxmlformats-officedocument.presentationml.slideshow",
    ".ppsm":      "application/vnd.ms-powerpoint.slideshow.macroEnabled.12",
    ".potx":      "application/vnd.openxmlformats-officedocument.presentationml.template",
    ".potm":      "application/vnd.ms-powerpoint.template.macroEnabled.12",
    ".ppam":      "application/vnd.ms-powerpoint.addin.macroEnabled.12",
    ".sldx":      "application/vnd.openxmlformats-officedocument.presentationml.slide",
    ".sldm":      "application/vnd.ms-powerpoint.slide.macroEnabled.12",
    ".thmx":      "application/vnd.ms-officetheme",
    ".onetoc":    "application/onenote",
    ".onetoc2":   "application/onenote",
    ".onetmp":    "application/onenote",
    ".onepkg":    "application/onenote",
    ".xpi":       "application/x-xpinstall",
}

func init() {
    for ext, typ := range types {
        // skip errors
        mime.AddExtensionType(ext, typ)
    }
}

// typeByExtension returns the MIME type associated with the file extension ext.
// The extension ext should begin with a leading dot, as in ".html".
// When ext has no associated type, typeByExtension returns "".
//
// Extensions are looked up first case-sensitively, then case-insensitively.
//
// The built-in table is small but on unix it is augmented by the local
// system's mime.types file(s) if available under one or more of these
// names:
//
//   /etc/mime.types
//   /etc/apache2/mime.types
//   /etc/apache/mime.types
//
// On Windows, MIME types are extracted from the registry.
//
// Text types have the charset parameter set to "utf-8" by default.
func TypeByExtension(fullfilename string) string {
    ext := filepath.Ext(fullfilename)
    typ := mime.TypeByExtension(ext)

    // mime.TypeByExtension returns as text/plain; | charset=utf-8 the static .js (not always)
    if ext == ".js" && (typ == "text/plain" || typ == "text/plain; charset=utf-8") {

        if ext == ".js" {
            typ = "application/javascript"
        }
    }
    return typ
}

Hope that helped you and other users, don't hesitate to post again if you have more questions!

JavaScript - cannot set property of undefined

In javascript almost everything is an object, null and undefined are exception.

Instances of Array is an object. so you can set property of an array, for the same reason,you can't set property of a undefined, because its NOT an object

Merge two array of objects based on a key

This is a version when you have an object and an array and you want to merge them and give the array a key value so it fits into the object nicely.

_x000D_
_x000D_
var fileData = [_x000D_
    { "id" : "1", "filename" : "myfile1", "score" : 33.1 }, _x000D_
    { "id" : "2", "filename" : "myfile2", "score" : 31.4 }, _x000D_
    { "id" : "3", "filename" : "myfile3", "score" : 36.3 }, _x000D_
    { "id" : "4", "filename" : "myfile4", "score" : 23.9 }_x000D_
];_x000D_
_x000D_
var fileQuality = [0.23456543,0.13413131,0.1941344,0.7854522];_x000D_
_x000D_
var newOjbect = fileData.map((item, i) => Object.assign({}, item, {fileQuality:fileQuality[i]}));_x000D_
_x000D_
console.log(newOjbect);
_x000D_
_x000D_
_x000D_

What does the servlet <load-on-startup> value signify

If the value is <0, the serlet is instantiated when the request comes, else >=0 the container will load in the increasing order of the values. if 2 or more servlets have the same value, then the order of the servlets declared in the web.xml.

YouTube embedded video: set different thumbnail

This solution will play the video upon clicking. You'll need to edit your picture to add a button image yourself.

You're going to need the URL of your picture and the YouTube video ID. The YouTube video id is the part of the URL after the v= parameter, so for https://www.youtube.com/watch?v=DODLEX4zzLQ the ID would be DODLEX4zzLQ.

<div width="560px" height="315px" style="position: static; clear: both; width: 560px; height: 315px;">&nbsp;<div style="position: relative"><img id="vidimg" width="560px" height="315px" src="URL_TO_PICTURE" style="position: absolute; top: 0; left: 0; cursor: pointer; pointer-events: none; z-index: 2;" /><iframe id="unlocked-video" style="position: absolute; top: 0; left: 0; z-index: 1;" src="https://www.youtube.com/embed/YOUTUBE_VIDEO_ID" width="560" height="315" frameborder="0" allowfullscreen="allowfullscreen"></iframe></div></div>
<script type="application/javascript">
  // Adapted from https://stackoverflow.com/a/32138108
  var monitor = setInterval(function(){
    var elem = document.activeElement;
    if(elem && elem.id == 'unlocked-video'){
      document.getElementById('vidimg').style.display='none';
      clearInterval(monitor);
    }
  }, 100);
</script>

Be sure to replace URL_TO_PICTURE and YOUTUBE_VIDEO_ID in the above snippet.

To clarify what's going on here, this displays the image on top of the video, but allows clicks to pass through the image. The script monitors for clicks in the video iframe, and then hides the image if a click occurs. You may not need the float: clear.

I haven't compared this to the other answers here, but this is what I have used.

How to use string.substr() function?

If I am correct, the second parameter of substr() should be the length of the substring. How about

b = a.substr(i,2);

?

Receiving JSON data back from HTTP request

What I normally do, similar to answer one:

var response = await httpClient.GetAsync(completeURL); // http://192.168.0.1:915/api/Controller/Object

if (response.IsSuccessStatusCode == true)
    {
        string res = await response.Content.ReadAsStringAsync();
        var content = Json.Deserialize<Model>(res);

// do whatever you need with the JSON which is in 'content'
// ex: int id = content.Id;

        Navigate();
        return true;
    }
    else
    {
        await JSRuntime.Current.InvokeAsync<string>("alert", "Warning, the credentials you have entered are incorrect.");
        return false;
    }

Where 'model' is your C# model class.

SQLite add Primary Key

I tried to add the primary key afterwards by changing the sqlite_master table directly. This trick seems to work. It is a hack solution of course.

In short: create a regular (unique) index on the table, then make the schema writable and change the name of the index to the form reserved by sqlite to identify a primary key index, (i.e. sqlite_autoindex_XXX_1, where XXX is the table name) and set the sql string to NULL. At last change the table definition itself. One pittfal: sqlite does not see the index name change until the database is reopened. This seems like a bug, but not a severe one (even without reopening the database, you can still use it).

Suppose the table looks like:

CREATE TABLE tab1(i INTEGER, j INTEGER, t TEXT);

Then I did the following:

BEGIN;
CREATE INDEX pk_tab1 ON tab1(i,j);
pragma writable_schema=1;
UPDATE sqlite_master SET name='sqlite_autoindex_tab1_1',sql=null WHERE name='pk_tab1';
UPDATE sqlite_master SET sql='CREATE TABLE tab1(i integer,j integer,t text,primary key(i,j))' WHERE name='tab1';
COMMIT;

Some tests (in sqlite shell):

sqlite> explain query plan select * from tab1 order by i,j;
0|0|0|SCAN TABLE tab1 USING INDEX sqlite_autoindex_tab1_1
sqlite> drop index sqlite_autoindex_tab1_1;
Error: index associated with UNIQUE or PRIMARY KEY constraint cannot be dropped    

PHP page redirect

I would probably set the message as a session variable, redirect the user to another page which displays the message and destroy the session.