Show SOME invisible/whitespace characters in Eclipse

I would prefer to keep the "Show Whitespace" button on the toolbar, so that in one click you can toggle it.

Go to Window -> Perspective -> Customize Perspective and enable to show the button on toolbar.

Best way to combine two or more byte arrays in C#

All you need to pass list of Byte Arrays and this function will return you the Array of Bytes (Merged). This is the best solution i think :).

public static byte[] CombineMultipleByteArrays(List<byte[]> lstByteArray)
        {
            using (var ms = new MemoryStream())
            {
                using (var doc = new iTextSharp.text.Document())
                {
                    using (var copy = new PdfSmartCopy(doc, ms))
                    {
                        doc.Open();
                        foreach (var p in lstByteArray)
                        {
                            using (var reader = new PdfReader(p))
                            {
                                copy.AddDocument(reader);
                            }
                        }

                        doc.Close();
                    }
                }
                return ms.ToArray();
            }
        }

My Routes are Returning a 404, How can I Fix Them?

Have you tried to check if

http://localhost/mysite/public/index.php/user

was working? If so then make sure all your path's folders don't have any uppercase letters. I had the same situation and converting letters to lower case helped.

Environment variable substitution in sed

I had similar problem, I had a list and I have to build a SQL script based on template (that contained @INPUT@ as element to replace):

for i in LIST 
do
    awk "sub(/\@INPUT\@/,\"${i}\");" template.sql >> output
done

How do you save/store objects in SharedPreferences on Android?

If you want to store the whole Object that you get in response, It can achieve by doing something like,

First Create a method that converts your JSON into a string in your util class as below.

 public static <T> T fromJson(String jsonString, Class<T> theClass) {
    return new Gson().fromJson(jsonString, theClass);
}

Then In Shared Preferences Class Do something like,

 public void storeLoginResponse(yourResponseClass objName) {

    String loginJSON = UtilClass.toJson(customer);
    if (!TextUtils.isEmpty(customerJSON)) {
        editor.putString(AppConst.PREF_CUSTOMER, customerJSON);
        editor.commit();
    }
}

and then create a method for getPreferences

public Customer getCustomerDetails() {
    String customerDetail = pref.getString(AppConst.PREF_CUSTOMER, null);
    if (!TextUtils.isEmpty(customerDetail)) {
        return GSONConverter.fromJson(customerDetail, Customer.class);
    } else {
        return new Customer();
    }
}

Then Just call the First method when you get response and second when you need to get data from share preferences like

String token = SharedPrefHelper.get().getCustomerDetails().getAccessToken();

that's all.

Hope it will help you.

Happy Coding();

Postgres: How to do Composite keys?

The error you are getting is in line 3. i.e. it is not in

CONSTRAINT no_duplicate_tag UNIQUE (question_id, tag_id)

but earlier:

CREATE TABLE tags
     (
              (question_id, tag_id) NOT NULL,

Correct table definition is like pilcrow showed.

And if you want to add unique on tag1, tag2, tag3 (which sounds very suspicious), then the syntax is:

CREATE TABLE tags (
    question_id INTEGER NOT NULL,
    tag_id SERIAL NOT NULL,
    tag1 VARCHAR(20),
    tag2 VARCHAR(20),
    tag3 VARCHAR(20),
    PRIMARY KEY(question_id, tag_id),
    UNIQUE (tag1, tag2, tag3)
);

or, if you want to have the constraint named according to your wish:

CREATE TABLE tags (
    question_id INTEGER NOT NULL,
    tag_id SERIAL NOT NULL,
    tag1 VARCHAR(20),
    tag2 VARCHAR(20),
    tag3 VARCHAR(20),
    PRIMARY KEY(question_id, tag_id),
    CONSTRAINT some_name UNIQUE (tag1, tag2, tag3)
);

How to show form input fields based on select value?

<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<script>
function myfun(){
$(document).ready(function(){

    $("#select").click(
    function(){
    var data=$("#select").val();
        $("#disp").val(data);
                     });
});
}
</script>
</head>
<body>

<p>id <input type="text" name="user" id="disp"></p>

<select id="select" onclick="myfun()">
<option name="1"value="1">first</option>
<option name="2"value="2">second</option>
</select>

</body>
</html>

Run function from the command line

I wrote a quick little Python script that is callable from a bash command line. It takes the name of the module, class and method you want to call and the parameters you want to pass. I call it PyRun and left off the .py extension and made it executable with chmod +x PyRun so that I can just call it quickly as follow:

./PyRun PyTest.ClassName.Method1 Param1

Save this in a file called PyRun

#!/usr/bin/env python
#make executable in bash chmod +x PyRun

import sys
import inspect
import importlib
import os

if __name__ == "__main__":
    cmd_folder = os.path.realpath(os.path.abspath(os.path.split(inspect.getfile( inspect.currentframe() ))[0]))
    if cmd_folder not in sys.path:
        sys.path.insert(0, cmd_folder)

    # get the second argument from the command line      
    methodname = sys.argv[1]

    # split this into module, class and function name
    modulename, classname, funcname = methodname.split(".")

    # get pointers to the objects based on the string names
    themodule = importlib.import_module(modulename)
    theclass = getattr(themodule, classname)
    thefunc = getattr(theclass, funcname)

    # pass all the parameters from the third until the end of 
    # what the function needs & ignore the rest
    args = inspect.getargspec(thefunc)
    z = len(args[0]) + 2
    params=sys.argv[2:z]
    thefunc(*params)

Here is a sample module to show how it works. This is saved in a file called PyTest.py:

class SomeClass:
 @staticmethod
 def First():
     print "First"

 @staticmethod
 def Second(x):
    print(x)
    # for x1 in x:
    #     print x1

 @staticmethod
 def Third(x, y):
     print x
     print y

class OtherClass:
    @staticmethod
    def Uno():
        print("Uno")

Try running these examples:

./PyRun PyTest.SomeClass.First
./PyRun PyTest.SomeClass.Second Hello
./PyRun PyTest.SomeClass.Third Hello World
./PyRun PyTest.OtherClass.Uno
./PyRun PyTest.SomeClass.Second "Hello"
./PyRun PyTest.SomeClass.Second \(Hello, World\)

Note the last example of escaping the parentheses to pass in a tuple as the only parameter to the Second method.

If you pass too few parameters for what the method needs you get an error. If you pass too many, it ignores the extras. The module must be in the current working folder, put PyRun can be anywhere in your path.

ImproperlyConfigured: You must either define the environment variable DJANGO_SETTINGS_MODULE or call settings.configure() before accessing settings

Create a .env file that will hold your credentials at the root of your project and leave it out of versioning:

$ echo ".env" >> .gitignore

In the .env file, add the variables (adapt them according to your installation):

$ echo "DJANGO_SETTINGS_MODULE=myproject.settings.production"> .env
#50 caracter random key
$ echo "SECRET_KEY='####'">> .env

To use them, put this on top of your production.py settings file:

import os

env = os.environ.copy()
SECRET_KEY = env['SECRET_KEY']

Publish it to Heroku using this gem: http://github.com/ddollar/heroku-config.git

$ heroku plugins:install git://github.com/ddollar/heroku-config.git
$ heroku config:push

This way you avoid to change virtualenv files.

*Based on this tutorial

VirtualBox Cannot register the hard disk already exists

The solution that worked for me is as follows:

Make sure VirtualBox Manager is not running.
Back up the files ~\.VirtualBox\VirtualBox.xml and ~\.VirtualBox\VirtualBox.xml-prev.
Edit these files to modify the <HardDisks>...</HardDisks> section to remove the duplicate entry of <HardDisk />.
Now run VirtualBox Manager.

Example:

  <HardDisks>
    <HardDisk uuid="{38f266bd-0959-4caf-a0de-27ac9d52e3663}" location="~/VirtualBox VMs/VM1/box-disk001.vmdk" format="VMDK" type="Normal"/>
    <HardDisk uuid="{a6708d79-7393-4d96-89da-2539f75c5465e}" location="~/VirtualBox VMs/VM2/box-disk001.vmdk" format="VMDK" type="Normal"/>
    <HardDisk uuid="{bdce5d4e-9a1c-4f57-acfd-e2acfc8920552}" location="~/VirtualBox VMs/VM2/box-disk001.vmdk" format="VMDK" type="Normal"/>
  </HardDisks>

Note in the above fragment that the last two entries refer to the same VM but have different uuid's. One of them is invalid and should be removed. Which one is invalid can be found out by hit and trial -- first remove the second entry and try; if it doesn't work, remove the third entry.

How to get Exception Error Code in C#

You should look at the members of the thrown exception, particularly .Message and .InnerException.

I would also see whether or not the documentation for InvokeMethod tells you whether it throws some more specialized Exception class than Exception - such as the Win32Exception suggested by @Preet. Catching and just looking at the Exception base class may not be particularly useful.

insert multiple rows into DB2 database

I disagree on the comment posted by Hogan. Those instructions will work for IBM DB2 Mini, but it's not the case of DB2 Z/OS.

Here is an example:

Exception data: org.apache.ibatis.exceptions.PersistenceException:
The error occurred while setting parameters

SQL: INSERT INTO TABLENAME(ID_, F1_, F2_, F3_, F4_, F5_) VALUES
 (?,          1,          ?,          ?,          ?,          ?),          
 (?,          1,          ?,          ?,          ?,          ?)


Cause: com.ibm.db2.jcc.am.SqlSyntaxErrorException: 
ILLEGAL SYMBOL ",". SOME SYMBOLS THAT MIGHT BE LEGAL ARE: FOR <END-OF-STATEMENT> NOT ATOMIC. SQLCODE=-104, SQLSTATE=42601, DRIVER=4.25.17

So I can confirm that inline comma separated bulk inserts are not working on DB2 Z/OS (maybe you could feed it some props to get it working...)

PHP: if !empty & empty

if(!empty($youtube) && empty($link)) {

}
else if(empty($youtube) && !empty($link)) {

}
else if(empty($youtube) && empty($link)) {
}

fstream won't create a file

You should add fstream::out to open method like this:

file.open("test.txt",fstream::out);

More information about fstream flags, check out this link: http://www.cplusplus.com/reference/fstream/fstream/open/

How to completely uninstall Android Studio from windows(v10)?

.android

check this folder in

C:\Users\user

its have an issue and fix it then restart android studio.

What's the best way to determine the location of the current PowerShell script?

I always use this little snippet which works for PowerShell and ISE the same way:

# Set active path to script-location:
$path = $MyInvocation.MyCommand.Path
if (!$path) {
    $path = $psISE.CurrentFile.Fullpath
}
if ($path) {
    $path = Split-Path $path -Parent
}
Set-Location $path

how to modify the size of a column

Regardless of what error Oracle SQL Developer may indicate in the syntax highlighting, actually running your alter statement exactly the way you originally had it works perfectly:

ALTER TABLE TEST_PROJECT2 MODIFY proj_name VARCHAR2(300);

You only need to add parenthesis if you need to alter more than one column at once, such as:

ALTER TABLE TEST_PROJECT2 MODIFY (proj_name VARCHAR2(400), proj_desc VARCHAR2(400));

calculate the mean for each column of a matrix in R

You can try this:

mean(as.matrix(cluster1))

How to stop java process gracefully?

Signalling in Linux can be done with "kill" (man kill for the available signals), you'd need the process ID to do that. (ps ax | grep java) or something like that, or store the process id when the process gets created (this is used in most linux startup files, see /etc/init.d)

Portable signalling can be done by integrating a SocketServer in your java application. It's not that difficult and gives you the freedom to send any command you want.

If you meant finally clauses in stead of finalizers; they do not get extecuted when System.exit() is called. Finalizers should work, but shouldn't really do anything more significant but print a debug statement. They're dangerous.

What HTTP status response code should I use if the request is missing a required parameter?

Status 422 seems most appropiate based on the spec.

The 422 (Unprocessable Entity) status code means the server understands the content type of the request entity (hence a 415(Unsupported Media Type) status code is inappropriate), and the syntax of the request entity is correct (thus a 400 (Bad Request) status code is inappropriate) but was unable to process the contained instructions. For example, this error condition may occur if an XML request body contains well-formed (i.e., syntactically correct), but semantically erroneous, XML instructions.

They state that malformed xml is an example of bad syntax (calling for a 400). A malformed query string seems analogous to this, so 400 doesn't seem appropriate for a well-formed query-string which is missing a param.

UPDATE @DavidV correctly points out that this spec is for WebDAV, not core HTTP. But some popular non-WebDAV APIs are using 422 anyway, for lack of a better status code (see this).

Python: One Try Multiple Except

Yes, it is possible.

try:
   ...
except FirstException:
   handle_first_one()

except SecondException:
   handle_second_one()

except (ThirdException, FourthException, FifthException) as e:
   handle_either_of_3rd_4th_or_5th()

except Exception:
   handle_all_other_exceptions()

See: http://docs.python.org/tutorial/errors.html

The "as" keyword is used to assign the error to a variable so that the error can be investigated more thoroughly later on in the code. Also note that the parentheses for the triple exception case are needed in python 3. This page has more info: Catch multiple exceptions in one line (except block)

How to deserialize a JObject to .NET object

From the documentation I found this

JObject o = new JObject(
   new JProperty("Name", "John Smith"),
   new JProperty("BirthDate", new DateTime(1983, 3, 20))
);

JsonSerializer serializer = new JsonSerializer();
Person p = (Person)serializer.Deserialize(new JTokenReader(o), typeof(Person));

Console.WriteLine(p.Name);

The class definition for Person should be compatible to the following:

class Person {
    public string Name { get; internal set; }
    public DateTime BirthDate { get; internal set; }
}

Edit

If you are using a recent version of JSON.net and don't need custom serialization, please see TienDo's answer above (or below if you upvote me :P ), which is more concise.

Filter output in logcat by tagname

use this:

adb logcat -s "TAGNAME"

Sass Variable in CSS calc() function

Here is a really simple solution using SASS/SCSS and a math formula style:

/* frame circle */
.container {
    position: relative;
    border-radius: 50%;
    background-color: white;
    overflow: hidden;
    width: 400px;
    height: 400px; }

/* circle sectors */
.menu-frame-sector {
    position: absolute;
    width: 50%;
    height: 50%;
    z-index: 10000;
    transform-origin: 100% 100%;
  }

$sector_count: 8;
$sector_width: 360deg / $sector_count;

.sec0 {
    transform: rotate(0 * $sector_width) skew($sector_width);
    background-color: red; }
.sec1 {
    transform: rotate(1 * $sector_width) skew($sector_width);
    background-color: blue; }
.sec2 {
    transform: rotate(2 * $sector_width) skew($sector_width);
    background-color: red; }
.sec3 {
    transform: rotate(3 * $sector_width) skew($sector_width);
    background-color: blue; }
.sec4 {
    transform: rotate(4 * $sector_width) skew($sector_width);
    background-color: red; }
.sec5 {
    transform: rotate(5 * $sector_width) skew($sector_width);
    background-color: blue; }
.sec6 {
    transform: rotate(6 * $sector_width) skew($sector_width);
    background-color: red; }
.sec7 {
    transform: rotate(7 * $sector_width) skew($sector_width);
    background-color: blue; }

To conclude, I strongly suggest you to understand transform-origin, rotate() and skew():

https://tympanus.net/codrops/2013/08/09/building-a-circular-navigation-with-css-transforms/

MySQL Removing Some Foreign keys

Here's a way to drop foreign key constraint, it will work. ALTER TABLE location.location_id DROP FOREIGN KEY location_ibfk_1;

SELECT COUNT in LINQ to SQL C#

Like that

var purchCount = (from purchase in myBlaContext.purchases select purchase).Count();

or even easier

var purchCount = myBlaContext.purchases.Count()

add commas to a number in jQuery

Here is my coffeescript version of @baacke's fiddle provided in a comment to @Timothy Perez

class Helpers
    @intComma: (number) ->
        # remove any existing commas
        comma = /,/g
        val = number.toString().replace comma, ''

        # separate the decimals
        valSplit = val.split '.'

        integer = valSplit[0].toString()
        expression = /(\d+)(\d{3})/
        while expression.test(integer)
            withComma = "$1,$2"
            integer = integer.toString().replace expression, withComma

        # recombine with decimals if any
        val = integer
        if valSplit.length == 2
            val = "#{val}.#{valSplit[1]}"

        return val

Click in OK button inside an Alert (Selenium IDE)

The new Selenium IDE (released in 2019) has a much broader API and new documentation.

I believe this is the command you'll want to try:

webdriver choose ok on visible confirmation

Described at:

https://www.seleniumhq.org/selenium-ide/docs/en/api/commands/#webdriver-choose-ok-on-visible-confirmation

There are other alert-related API calls; just search that page for alert

Convert Dictionary to JSON in Swift

Sometimes it's necessary to print out server's response for debugging purposes. Here's a function I use:

extension Dictionary {

    var json: String {
        let invalidJson = "Not a valid JSON"
        do {
            let jsonData = try JSONSerialization.data(withJSONObject: self, options: .prettyPrinted)
            return String(bytes: jsonData, encoding: String.Encoding.utf8) ?? invalidJson
        } catch {
            return invalidJson
        }
    }

    func printJson() {
        print(json)
    }

}

Example of use:

(lldb) po dictionary.printJson()
{
  "InviteId" : 2,
  "EventId" : 13591,
  "Messages" : [
    {
      "SenderUserId" : 9514,
      "MessageText" : "test",
      "RecipientUserId" : 9470
    },
    {
      "SenderUserId" : 9514,
      "MessageText" : "test",
      "RecipientUserId" : 9470
    }
  ],
  "TargetUserId" : 9470,
  "InvitedUsers" : [
    9470
  ],
  "InvitingUserId" : 9514,
  "WillGo" : true,
  "DateCreated" : "2016-08-24 14:01:08 +00:00"
}

How to get all the values of input array element jquery

By Using map

var values = $("input[name='pname[]']")
              .map(function(){return $(this).val();}).get();

How to change heatmap.2 color range in R?

Here's another option for those not using heatmap.2 (aheatmap is good!)

Make a sequential vector of 100 values from min to max of your input matrix, find value closest to 0 in that, make two vector of colours to and from desired midpoint, combine and use them:

breaks <- seq(from=min(range(inputMatrix)), to=max(range(inputMatrix)), length.out=100)
midpoint <- which.min(abs(breaks - 0))
rampCol1 <- colorRampPalette(c("forestgreen", "darkgreen", "black"))(midpoint)
rampCol2 <- colorRampPalette(c("black", "darkred", "red"))(100-(midpoint+1))
rampCols <- c(rampCol1,rampCol2)

CodeIgniter Select Query

Here is the example of the code:

public function getItemName()
{
    $this->db->select('Id,Name');
    $this->db->from('item');
    $this->db->where(array('Active' => 1));
    return $this->db->get()->result();
}

Ruby class instance variable vs. class variable

Official Ruby FAQ: What is the difference between class variables and class instance variables?

The main difference is the behavior concerning inheritance: class variables are shared between a class and all its subclasses, while class instance variables only belong to one specific class.

Class variables in some way can be seen as global variables within the context of an inheritance hierarchy, with all the problems that come with global variables. For instance, a class variable might (accidentally) be reassigned by any of its subclasses, affecting all other classes:

class Woof

  @@sound = "woof"

  def self.sound
    @@sound
  end
end

Woof.sound  # => "woof"

class LoudWoof < Woof
  @@sound = "WOOF"
end

LoudWoof.sound  # => "WOOF"
Woof.sound      # => "WOOF" (!)

Or, an ancestor class might later be reopened and changed, with possibly surprising effects:

class Foo

  @@var = "foo"

  def self.var
    @@var
  end
end

Foo.var  # => "foo" (as expected)

class Object
  @@var = "object"
end

Foo.var  # => "object" (!)

So, unless you exactly know what you are doing and explicitly need this kind of behavior, you better should use class instance variables.

Convert a JSON string to object in Java ME?

Use google GSON library for this

public static <T> T getObject(final String jsonString, final Class<T> objectClass) {  
    Gson gson = new Gson();  
    return gson.fromJson(jsonString, objectClass);  
}

http://iandjava.blogspot.in/2014/01/java-object-to-json-and-json-to-java.html

How to test code dependent on environment variables using JUnit?

A lot of focus in the suggestions above on inventing ways in runtime to pass in variables, set them and clear them and so on..? But to test things 'structurally', I guess you want to have different test suites for different scenarios? Pretty much like when you want to run your 'heavier' integration test builds, whereas in most cases you just want to skip them. But then you don't try and 'invent ways to set stuff in runtime', rather you just tell maven what you want? It used to be a lot of work telling maven to run specific tests via profiles and such, if you google around people would suggest doing it via springboot (but if you haven't dragged in the springboot monstrum into your project, it seems a horrendous footprint for 'just running JUnits', right?). Or else it would imply loads of more or less inconvenient POM XML juggling which is also tiresome and, let's just say it, 'a nineties move', as inconvenient as still insisting on making 'spring beans out of XML', showing off your ultimate 600 line logback.xml or whatnot...?

Nowadays, you can just use Junit 5 (this example is for maven, more details can be found here JUnit 5 User Guide 5)

 <dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.junit</groupId>
            <artifactId>junit-bom</artifactId>
            <version>5.7.0</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

and then

    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter</artifactId>
        <scope>test</scope>
    </dependency>

and then in your favourite utility lib create a simple nifty annotation class such as

@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
@EnabledIfEnvironmentVariable(named = "MAVEN_CMD_LINE_ARGS", matches = "(.*)integration-testing(.*)")
public @interface IntegrationTest {}

so then whenever your cmdline options contain -Pintegration-testing for instance, then and only then will your @IntegrationTest annotated test-class/method fire. Or, if you don't want to use (and setup) a specific maven profile but rather just pass in 'trigger' system properties by means of

mvn <cmds> -DmySystemPop=mySystemPropValue

and adjust your annotation interface to trigger on that (yes, there is also a @EnabledIfSystemProperty). Or making sure your shell is set up to contain 'whatever you need' or, as is suggested above, actually going through 'the pain' adding system env via your POM XML.

Having your code internally in runtime fiddle with env or mocking env, setting it up and then possibly 'clearing' runtime env to change itself during execution just seems like a bad, perhaps even dangerous, approach - it's easy to imagine someone will always sooner or later make a 'hidden' internal mistake that will go unnoticed for a while, just to arise suddenly and bite you hard in production later..? You usually prefer an approach entailing that 'given input' gives 'expected output', something that is easy to grasp and maintain over time, your fellow coders will just see it 'immediately'.

Well long 'answer' or maybe rather just an opinion on why you'd prefer this approach (yes, at first I just read the heading for this question and went ahead to answer that, ie 'How to test code dependent on environment variables using JUnit').

Saving a select count(*) value to an integer (SQL Server)

If @myInt is zero it means no rows in the table: it would be NULL if never set at all.

COUNT will always return a row, even for no rows in a table.

Edit, Apr 2012: the rules for this are described in my answer here:Does COUNT(*) always return a result?

Your count/assign is correct but could be either way:

select @myInt = COUNT(*) from myTable
set @myInt = (select COUNT(*) from myTable)

However, if you are just looking for the existence of rows, (NOT) EXISTS is more efficient:

IF NOT EXISTS (SELECT * FROM myTable)

Why are only a few video games written in Java?

Java is slow, most of the heavy lifting is not handled by the GPU. There's still animation, physics, and AI hitting the CPU, all of which are very time-consuming.
Java doesn't exist on consoles, and consoles are a major target for commercial games. If you use Java on PC, you're eliminating your ability to port to consoles within reasonable time and budget.
Many of the more experienced coders in the game industry have been using C and C++ long before Java became popular. The two points above may contribute to this, but I expect that many professional game coders just don't really know Java all that well.
Someone else's point about middleware above was a good one, so I'm adding it to my answer. There's a lot of legacy code and middleware written specifically to link with C/C++, and last I checked Java doesn't have good interoperability. Using Java for most companies would involve throwing out a lot of code, much of which has been paid for in one way or another.

document.all vs. document.getElementById

document.all is a proprietary Microsoft extension to the W3C standard.

getElementById() is standard - use that.

However, consider if using a js library like jQuery would come in handy. For example, $("#id") is the jQuery equivalent for getElementById(). Plus, you can use more than just CSS3 selectors.

Print array elements on separate lines in Bash?

Try doing this :

$ printf '%s\n' "${my_array[@]}"

The difference between $@ and $*:

Unquoted, the results are unspecified. In Bash, both expand to separate args and then wordsplit and globbed.
Quoted, "$@" expands each element as a separate argument, while "$*" expands to the args merged into one argument: "$1c$2c..." (where c is the first char of IFS).

You almost always want "$@". Same goes for "${arr[@]}".

Always quote them!

Push eclipse project to GitHub with EGit

The key lies in when you create the project in eclipse.

First step, you create the Java project in eclipse. Right click on the project and choose Team > Share>Git.

In the Configure Git Repository dialog, ensure that you select the option to create the Repository in the parent folder of the project.. enter image description here Then you can push to github.

N.B: Eclipse will give you a warning about putting git repositories in your workspace. So when you create your project, set your project directory outside the default workspace.

Is it possible to specify the schema when connecting to postgres with JDBC?

I submitted an updated version of a patch to the PostgreSQL JDBC driver to enable this a few years back. You'll have to build the PostreSQL JDBC driver from source (after adding in the patch) to use it:

http://archives.postgresql.org/pgsql-jdbc/2008-07/msg00012.php

http://jdbc.postgresql.org/

Angular 2 Checkbox Two Way Data Binding

Unfortunately solution provided by @hakani is not two-way binding. It just handles One-way changing model from UI/FrontEnd part.

Instead the simple:

<input [(ngModel)]="checkboxFlag" type="checkbox"/>

will do two-way binding for checkbox.

Afterwards, when Model checkboxFlag is changed from Backend or UI part - voila, checkboxFlag stores actual checkbox state.

To be sure I've prepared Plunker code to present the result : https://plnkr.co/edit/OdEAPWRoqaj0T6Yp0Mfk

Just to complete this answer you should include the import { FormsModule } from '@angular/forms' into app.module.ts and add to imports array i.e

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

[...]

@NgModule({
  imports: [
    [...]
    FormsModule
  ],
  [...]
})

ORA-00904: invalid identifier

Also make sure the user issuing the query has been granted the necessary permissions.

For queries on tables you need to grant SELECT permission.
For queries on other object types (e.g. stored procedures) you need to grant EXECUTE permission.

CSS Div stretch 100% page height

* {
margin: 0;
}
html, body {
height: 90%;
}
.content {
min-height: 100%;
height: auto !important;
height: 100%;
margin: 0 auto ;
}

JSF(Primefaces) ajax update of several elements by ID's

If the to-be-updated component is not inside the same NamingContainer component (ui:repeat, h:form, h:dataTable, etc), then you need to specify the "absolute" client ID. Prefix with : (the default NamingContainer separator character) to start from root.

<p:ajax process="@this" update="count :subTotal"/>

To be sure, check the client ID of the subTotal component in the generated HTML for the actual value. If it's inside for example a h:form as well, then it's prefixed with its client ID as well and you would need to fix it accordingly.

<p:ajax process="@this" update="count :formId:subTotal"/>

Space separation of IDs is more recommended as <f:ajax> doesn't support comma separation and starters would otherwise get confused.

ORA-01034: ORACLE not available ORA-27101: shared memory realm does not exist

I hope you have resolved your issue. If you still got issue then double check again if you install this Oracle under a domain account. I found a thread that says Oracle XE giving same error when installing under domain account. Please use a local account instead.

Source:

https://community.oracle.com/thread/2141735?start=0&tstart=0

Error to run Android Studio

On ubuntu I have tried all the methods that are described here but none worked.

What I did in the end was to:

download JDK from oracle, extract the archive
edit android-studio/bin/studio.sh and add at the top

export JAVA_HOME=/path/to/jdk
save the file and cd android-studio/bin and launch Android Studio: ./studio.sh

Is There a Better Way of Checking Nil or Length == 0 of a String in Ruby?

I like to do this as follows (in a non Rails/ActiveSupport environment):

variable.to_s.empty?

this works because:

nil.to_s == ""
"".to_s == ""

How to set the text/value/content of an `Entry` widget using a button in tkinter

You can choose between the following two methods to set the text of an Entry widget. For the examples, assume imported library import tkinter as tk and root window root = tk.Tk().

Method A: Use delete and insert

Widget Entry provides methods delete and insert which can be used to set its text to a new value. First, you'll have to remove any former, old text from Entry with delete which needs the positions where to start and end the deletion. Since we want to remove the full old text, we start at 0 and end at wherever the end currently is. We can access that value via END. Afterwards the Entry is empty and we can insert new_text at position 0.
```
entry = tk.Entry(root)
new_text = "Example text"
entry.delete(0, tk.END)
entry.insert(0, new_text)
```

Method B: Use StringVar

You have to create a new StringVar object called entry_text in the example. Also, your Entry widget has to be created with keyword argument textvariable. Afterwards, every time you change entry_text with set, the text will automatically show up in the Entry widget.
```
entry_text = tk.StringVar()
entry = tk.Entry(root, textvariable=entry_text)
new_text = "Example text"
entry_text.set(new_text)
```

Complete working example which contains both methods to set the text via Button:

This window

is generated by the following complete working example:

import tkinter as tk

def button_1_click():
    # define new text (you can modify this to your needs!)
    new_text = "Button 1 clicked!"
    # delete content from position 0 to end
    entry.delete(0, tk.END)
    # insert new_text at position 0
    entry.insert(0, new_text)

def button_2_click():
    # define new text (you can modify this to your needs!)
    new_text = "Button 2 clicked!"
    # set connected text variable to new_text
    entry_text.set(new_text)

root = tk.Tk()

entry_text = tk.StringVar()
entry = tk.Entry(root, textvariable=entry_text)

button_1 = tk.Button(root, text="Button 1", command=button_1_click)
button_2 = tk.Button(root, text="Button 2", command=button_2_click)

entry.pack(side=tk.TOP)
button_1.pack(side=tk.LEFT)
button_2.pack(side=tk.LEFT)

root.mainloop()

api-ms-win-crt-runtime-l1-1-0.dll is missing when opening Microsoft Office file

The default solution is to install KB2999226 of Microsoft.

Fixed positioning in Mobile Safari

This fixed position div can be achieved in just 2 lines of code which moves the div on scroll to the bottom of the page.

window.onscroll = function() {
  document.getElementById('fixedDiv').style.top =
     (window.pageYOffset + window.innerHeight - 25) + 'px';
};

How to set null value to int in c#?

int ? index = null;

public int Index
        {
            get
            {
                if (index.HasValue) // Check for value
                    return index.Value; //Return value if index is not "null"
                else return 777; // If value is "null" return 777 or any other value
            }
            set { index = value; }
        }

Why is Java Vector (and Stack) class considered obsolete or deprecated?

java.util.Stack inherits the synchronization overhead of java.util.Vector, which is usually not justified.

It inherits a lot more than that, though. The fact that java.util.Stack extends java.util.Vector is a mistake in object-oriented design. Purists will note that it also offers a lot of methods beyond the operations traditionally associated with a stack (namely: push, pop, peek, size). It's also possible to do search, elementAt, setElementAt, remove, and many other random-access operations. It's basically up to the user to refrain from using the non-stack operations of Stack.

For these performance and OOP design reasons, the JavaDoc for java.util.Stack recommends ArrayDeque as the natural replacement. (A deque is more than a stack, but at least it's restricted to manipulating the two ends, rather than offering random access to everything.)

React.js: Identifying different inputs with one onChange handler

The key of your state should be the same as the name of your input field. Then you can do this in the handleEvent method;

this.setState({
        [event.target.name]: event.target.value
});

Make Vim show ALL white spaces as a character

Adding this to my .vimrc works for me. Just make sure you don't have anything else conflicting..

autocmd VimEnter * :syn match space /\s/
autocmd VimEnter * :hi space ctermbg=lightgray ctermfg=black guibg=lightgray guifg=black

Signed to unsigned conversion in C - is it always safe?

What implicit conversions are going on here,

i will be converted to an unsigned integer.

and is this code safe for all values of u and i?

Safe in the sense of being well-defined yes (see https://stackoverflow.com/a/50632/5083516 ).

The rules are written in typically hard to read standards-speak but essentially whatever representation was used in the signed integer the unsigned integer will contain a 2's complement representation of the number.

Addition, subtraction and multiplication will work correctly on these numbers resulting in another unsigned integer containing a twos complement number representing the "real result".

division and casting to larger unsigned integer types will have well-defined results but those results will not be 2's complement representations of the "real result".

(Safe, in the sense that even though result in this example will overflow to some huge positive number, I could cast it back to an int and get the real result.)

While conversions from signed to unsigned are defined by the standard the reverse is implementation-defined both gcc and msvc define the conversion such that you will get the "real result" when converting a 2's complement number stored in an unsigned integer back to a signed integer. I expect you will only find any other behaviour on obscure systems that don't use 2's complement for signed integers.

https://gcc.gnu.org/onlinedocs/gcc/Integers-implementation.html#Integers-implementation https://msdn.microsoft.com/en-us/library/0eex498h.aspx

Echoing the last command run in Bash?

There is a racecondition between the last command ($_) and last error ( $?) variables. If you try to store one of them in an own variable, both encountered new values already because of the set command. Actually, last command hasn't got any value at all in this case.

Here is what i did to store (nearly) both informations in own variables, so my bash script can determine if there was any error AND setting the title with the last run command:

   # This construct is needed, because of a racecondition when trying to obtain
   # both of last command and error. With this the information of last error is
   # implied by the corresponding case while command is retrieved.

   if   [[ "${?}" == 0 && "${_}" != "" ]] ; then
    # Last command MUST be retrieved first.
      LASTCOMMAND="${_}" ;
      RETURNSTATUS='?' ;
   elif [[ "${?}" == 0 && "${_}" == "" ]] ; then
      LASTCOMMAND='unknown' ;
      RETURNSTATUS='?' ;
   elif [[ "${?}" != 0 && "${_}" != "" ]] ; then
    # Last command MUST be retrieved first.
      LASTCOMMAND="${_}" ;
      RETURNSTATUS='?' ;
      # Fixme: "$?" not changing state until command executed.
   elif [[ "${?}" != 0 && "${_}" == "" ]] ; then
      LASTCOMMAND='unknown' ;
      RETURNSTATUS='?' ;
      # Fixme: "$?" not changing state until command executed.
   fi

This script will retain the information, if an error occured and will obtain the last run command. Because of the racecondition i can not store the actual value. Besides, most commands actually don't even care for error noumbers, they just return something different from '0'. You'll notice that, if you use the errono extention of bash.

It should be possible with something like a "intern" script for bash, like in bash extention, but i'm not familiar with something like that and it wouldn't be compatible as well.

CORRECTION

I didn't think, that it was possible to retrieve both variables at the same time. Although i like the style of the code, i assumed it would be interpreted as two commands. This was wrong, so my answer devides down to:

   # Because of a racecondition, both MUST be retrieved at the same time.
   declare RETURNSTATUS="${?}" LASTCOMMAND="${_}" ;

   if [[ "${RETURNSTATUS}" == 0 ]] ; then
      declare RETURNSYMBOL='?' ;
   else
      declare RETURNSYMBOL='?' ;
   fi

Although my post might not get any positive rating, i solved my problem myself, finally. And this seems appropriate regarding the intial post. :)

How to run a script as root on Mac OS X?

As in any unix-based environment, you can use the sudo command:

$ sudo script-name

It will ask for your password (your own, not a separate root password).

Remove from the beginning of std::vector

Given

std::vector<Rule>& topPriorityRules;

The correct way to remove the first element of the referenced vector is

topPriorityRules.erase(topPriorityRules.begin());

which is exactly what you suggested.

Looks like i need to do iterator overloading.

There is no need to overload an iterator in order to erase first element of std::vector.

P.S. Vector (dynamic array) is probably a wrong choice of data structure if you intend to erase from the front.

How to compute the sum and average of elements in an array?

I am just building on Abdennour TOUMI's answer. here are the reasons why:

1.) I agree with Brad, I do not think it is a good idea to extend object that we did not create.

2.) array.length is exactly reliable in javascript, I prefer Array.reduce beacuse a=[1,3];a[1000]=5; , now a.length would return 1001.

function getAverage(arry){
    // check if array
    if(!(Object.prototype.toString.call(arry) === '[object Array]')){
        return 0;
    }
    var sum = 0, count = 0; 
    sum = arry.reduce(function(previousValue, currentValue, index, array) {
        if(isFinite(currentValue)){
            count++;
            return previousValue+ parseFloat(currentValue);
        }
        return previousValue;
    }, sum);
    return count ? sum / count : 0; 
};

Writing to an Excel spreadsheet

The xlsxwriter library is great for creating .xlsx files. The following snippet generates an .xlsx file from a list of dicts while stating the order and the displayed names:

from xlsxwriter import Workbook


def create_xlsx_file(file_path: str, headers: dict, items: list):
    with Workbook(file_path) as workbook:
        worksheet = workbook.add_worksheet()
        worksheet.write_row(row=0, col=0, data=headers.values())
        header_keys = list(headers.keys())
        for index, item in enumerate(items):
            row = map(lambda field_id: item.get(field_id, ''), header_keys)
            worksheet.write_row(row=index + 1, col=0, data=row)


headers = {
    'id': 'User Id',
    'name': 'Full Name',
    'rating': 'Rating',
}

items = [
    {'id': 1, 'name': "Ilir Meta", 'rating': 0.06},
    {'id': 2, 'name': "Abdelmadjid Tebboune", 'rating': 4.0},
    {'id': 3, 'name': "Alexander Lukashenko", 'rating': 3.1},
    {'id': 4, 'name': "Miguel Díaz-Canel", 'rating': 0.32}
]

create_xlsx_file("my-xlsx-file.xlsx", headers, items)

Note 1 - I'm purposely not answering to the exact case the OP presented. Instead, I'm presenting a more generic solution IMHO most visitors seek. This question's title is well-indexed in search engines and tracks lots of traffic

Note 2 - If you're not using Python3.6 or newer, consider using OrderedDict in headers. Before Python3.6 the order in dict was not preserved.

Is there a Pattern Matching Utility like GREP in Windows?

It has been a while since I've used them, but Borland (Embarcadero now) included a command line grep with their C/C++ compiler. For some time, they have made available their 5.5 version as a free download after registering.

How to convert all text to lowercase in Vim

Usually Vu (or VU for uppercase) is enough to turn the whole line into lowercase as V already selects the whole line to apply the action against.

Tilda (~) changes the case of the individual letter, resulting in camel case or the similar.

It is really great how Vim has many many different modes to deal with various occasions and how those modes are neatly organized.

For instance, v - the true visual mode, and the related V - visual line, and Ctrl+Q - visual block modes (what allows you to select blocks, a great feature some other advanced editors also offer usually by holding the Alt key and selecting the text).

How to debug Spring Boot application with Eclipse?

Why don't you just right click on the main() method and choose "Debug As... Java Application"?

How to create an on/off switch with Javascript/CSS?

Outline: Create two elements: a slider/switch and a trough as a parent of the slider. To toggle the state, switch the slider element between an "on" and an "off" class. In the style for one class, set "left" to 0 and leave "right" the default; for the other class, do the opposite:

<style type="text/css">
.toggleSwitch {
    width: ...;
    height: ...;
    /* add other styling as appropriate to position element */
    position: relative;
}
.slider {
    background-image: url(...);
    position: absolute;
    width: ...;
    height: ...;
}
.slider.on {
    right: 0;
}
.slider.off {
    left: 0;
}
</style>
<script type="text/javascript">
function replaceClass(elt, oldClass, newClass) {
    var oldRE = RegExp('\\b'+oldClass+'\\b');
    elt.className = elt.className.replace(oldRE, newClass);
}
function toggle(elt, on, off) {
    var onRE = RegExp('\\b'+on+'\\b');
    if (onRE.test(elt.className)) {
        elt.className = elt.className.replace(onRE, off);
    } else {
        replaceClass(elt, off, on);
    }
}
</script>
...
<div class="toggleSwitch" onclick="toggle(this.firstChild, 'on', 'off');"><div class="slider off" /></div>

Alternatively, just set the background image for the "on" and "off" states, which is a much easier approach than mucking about with positioning.

How to import classes defined in init.py

'lib/'s parent directory must be in sys.path.

Your 'lib/__init__.py' might look like this:

from . import settings # or just 'import settings' on old Python versions
class Helper(object):
      pass

Then the following example should work:

from lib.settings import Values
from lib import Helper

Answer to the edited version of the question:

__init__.py defines how your package looks from outside. If you need to use Helper in settings.py then define Helper in a different file e.g., 'lib/helper.py'.

.
|   `-- import_submodule.py
    `-- lib
    |-- __init__.py
    |-- foo
    |   |-- __init__.py
    |   `-- someobject.py
    |-- helper.py
    `-- settings.py

2 directories, 6 files

The command:

$ python import_submodule.py

Output:

settings
helper
Helper in lib.settings
someobject
Helper in lib.foo.someobject

# ./import_submodule.py
import fnmatch, os
from lib.settings import Values
from lib import Helper

print
for root, dirs, files in os.walk('.'):
    for f in fnmatch.filter(files, '*.py'):
        print "# %s/%s" % (os.path.basename(root), f)
        print open(os.path.join(root, f)).read()
        print


# lib/helper.py
print 'helper'
class Helper(object):
    def __init__(self, module_name):
        print "Helper in", module_name


# lib/settings.py
print "settings"
import helper

class Values(object):
    pass

helper.Helper(__name__)


# lib/__init__.py
#from __future__ import absolute_import
import settings, foo.someobject, helper

Helper = helper.Helper


# foo/someobject.py
print "someobject"
from .. import helper

helper.Helper(__name__)


# foo/__init__.py
import someobject

Determine whether an array contains a value

You can use _.indexOf method or if you don't want to include whole Underscore.js library in your app, you can have a look how they did it and extract necessary code.

    _.indexOf = function(array, item, isSorted) {
    if (array == null) return -1;
    var i = 0, l = array.length;
    if (isSorted) {
      if (typeof isSorted == 'number') {
        i = (isSorted < 0 ? Math.max(0, l + isSorted) : isSorted);
      } else {
        i = _.sortedIndex(array, item);
        return array[i] === item ? i : -1;
      }
    }
    if (nativeIndexOf && array.indexOf === nativeIndexOf) return array.indexOf(item, isSorted);
    for (; i < l; i++) if (array[i] === item) return i;
    return -1;
  };

WHILE LOOP with IF STATEMENT MYSQL

I have discovered that you cannot have conditionals outside of the stored procedure in mysql. This is why the syntax error. As soon as I put the code that I needed between

   BEGIN
   SELECT MONTH(CURDATE()) INTO @curmonth;
   SELECT MONTHNAME(CURDATE()) INTO @curmonthname;
   SELECT DAY(LAST_DAY(CURDATE())) INTO @totaldays;
   SELECT FIRST_DAY(CURDATE()) INTO @checkweekday;
   SELECT DAY(@checkweekday) INTO @checkday;
   SET @daycount = 0;
   SET @workdays = 0;

     WHILE(@daycount < @totaldays) DO
       IF (WEEKDAY(@checkweekday) < 5) THEN
         SET @workdays = @workdays+1;
       END IF;
       SET @daycount = @daycount+1;
       SELECT ADDDATE(@checkweekday, INTERVAL 1 DAY) INTO @checkweekday;
     END WHILE;
   END

Just for others:

If you are not sure how to create a routine in phpmyadmin you can put this in the SQL query

    delimiter ;;
    drop procedure if exists test2;;
    create procedure test2()
    begin
    select ‘Hello World’;
    end
    ;;

Run the query. This will create a stored procedure or stored routine named test2. Now go to the routines tab and edit the stored procedure to be what you want. I also suggest reading http://net.tutsplus.com/tutorials/an-introduction-to-stored-procedures/ if you are beginning with stored procedures.

The first_day function you need is: How to get first day of every corresponding month in mysql?

Showing the Procedure is working Simply add the following line below END WHILE and above END

    SELECT @curmonth,@curmonthname,@totaldays,@daycount,@workdays,@checkweekday,@checkday;

Then use the following code in the SQL Query Window.

    call test2 /* or whatever you changed the name of the stored procedure to */

NOTE: If you use this please keep in mind that this code does not take in to account nationally observed holidays (or any holidays for that matter).

Why does calling sumr on a stream with 50 tuples not complete

sumr is implemented in terms of foldRight:

 final def sumr(implicit A: Monoid[A]): A = F.foldRight(self, A.zero)(A.append)

foldRight is not always tail recursive, so you can overflow the stack if the collection is too long. See Why foldRight and reduceRight are NOT tail recursive? for some more discussion of when this is or isn't true.

Convert a SQL query result table to an HTML table for email

JustinStolle's answer in a different way. A few notes:

The print statement may truncate the string to 4000 characters, but my test string for example was 9520 characters in length.
The [tr/th] indicates hierarchy, e.g., <tr><th>...</th></tr>.
The [@name] adds fields as XML attributes.
MS SQL XML concatenates fields of the same name, so null in between fields prevents that.

declare @body nvarchar(max)

select @body = cast((
    select N'2' [@cellpadding], N'2' [@cellspacing], N'1' [@border],
           N'Database Table' [tr/th], null [tr/td],
           N'Entity Count' [tr/th], null [tr/td],
           N'Total Rows' [tr/th], null,
           (select  object_name( object_id ) [td], null,
                    count( distinct name ) [td], null,
                    count( * )  [td], null
             from sys.columns
             group by object_name( object_id )
             for xml path('tr'), type)
        for xml path('table'), type
        ) as nvarchar(max))

print @body  -- only shows up to 4000 characters depending

How to install both Python 2.x and Python 3.x in Windows

I use a simple solution to switch from a version to another version of python, you can install all version you want. All you have to do is creating some variable environment. In my case, I have installed python 2.7 and python 3.8.1, so I have created this environment variables:

PYTHON_HOME_2.7=<path_python_2.7> PYTHON_HOME_3.8.1=<path_python_3.8.1> PYTHON_HOME=%PYTHON_HOME_2.7%

then in my PATH environment variable I put only %PYTHON_HOME% and %PYTHON_HOME%\Scripts. In the example above I'm using the version 2.7, when I want to switch to the other version I have only to set the PYTHON_HOME=%PYTHON_HOME_3.8.1%. I use this method to switch quickly from a version to another also for JAVA, MAVEN, GRADLE,ANT, and so on.

How can I get a list of all open named pipes in Windows?

In the Windows Powershell console, type

[System.IO.Directory]::GetFiles("\\.\\pipe\\")

If your OS version is greater than Windows 7, you can also type

get-childitem \\.\pipe\

This returns a list of objects. If you want the name only:

(get-childitem \\.\pipe\).FullName

(The second example \\.\pipe\ does not work in Powershell 7, but the first example does)

Pretty Printing a pandas dataframe

I used Ofer's answer for a while and found it great in most cases. Unfortunately, due to inconsistencies between pandas's to_csv and prettytable's from_csv, I had to use prettytable in a different way.

One failure case is a dataframe containing commas:

pd.DataFrame({'A': [1, 2], 'B': ['a,', 'b']})

Prettytable raises an error of the form:

Error: Could not determine delimiter

The following function handles this case:

def format_for_print(df):    
    table = PrettyTable([''] + list(df.columns))
    for row in df.itertuples():
        table.add_row(row)
    return str(table)

If you don't care about the index, use:

def format_for_print2(df):    
    table = PrettyTable(list(df.columns))
    for row in df.itertuples():
        table.add_row(row[1:])
    return str(table)

Disable browsers vertical and horizontal scrollbars

In modern versions of IE (IE10 and above), scrollbars can be hidden using the -ms-overflow-style property.

html {
     -ms-overflow-style: none;
}

In Chrome, scrollbars can be styled:

::-webkit-scrollbar {
    display: none;
}

This is very useful if you want to use the 'default' body scrolling in a web application, which is considerably faster than overflow-y: scroll.

Untrack files from git temporarily

Use following command to untrack files

git rm --cached <file path>

How to calculate combination and permutation in R?

If you don't want your code to depend on other packages, you can always just write these functions:

perm = function(n, x) {
  factorial(n) / factorial(n-x)
}

comb = function(n, x) {
  factorial(n) / factorial(n-x) / factorial(x)
}

How to set default values in Rails?

If you are referring to ActiveRecord objects, you have (more than) two ways of doing this:

1. Use a :default parameter in the DB

E.G.

class AddSsl < ActiveRecord::Migration
  def self.up
    add_column :accounts, :ssl_enabled, :boolean, :default => true
  end

  def self.down
    remove_column :accounts, :ssl_enabled
  end
end

More info here: http://api.rubyonrails.org/classes/ActiveRecord/Migration.html

2. Use a callback

E.G. before_validation_on_create

More info here: http://api.rubyonrails.org/classes/ActiveRecord/Callbacks.html#M002147

How can I issue a single command from the command line through sql plus?

This is how I solved the problem:

<target name="executeSQLScript">
    <exec executable="sqlplus" failonerror="true" errorproperty="exit.status">
        <arg value="${dbUser}/${dbPass}@<DBHOST>:<DBPORT>/<SID>"/>
        <arg value="@${basedir}/db/scripttoexecute.sql"/>
    </exec>
</target>

Running bash script from within python

Making sleep.sh executable and adding shell=True to the parameter list (as suggested in previous answers) works ok. Depending on the search path, you may also need to add ./ or some other appropriate path. (Ie, change "sleep.sh" to "./sleep.sh".)

The shell=True parameter is not needed (under a Posix system like Linux) if the first line of the bash script is a path to a shell; for example, #!/bin/bash.

How to loop an object in React?

You can use it in a more compact way as:

var tifs = {1: 'Joe', 2: 'Jane'};
...

return (
   <select id="tif" name="tif" onChange={this.handleChange}>  
      { Object.entries(tifs).map((t,k) => <option key={k} value={t[0]}>{t[1]}</option>) }          
   </select>
)

And another slightly different flavour:

 Object.entries(tifs).map(([key,value],i) => <option key={i} value={key}>{value}</option>)

Break statement in javascript array map method

That's not possible using the built-in Array.prototype.map. However, you could use a simple for-loop instead, if you do not intend to map any values:

var hasValueLessThanTen = false;
for (var i = 0; i < myArray.length; i++) {
  if (myArray[i] < 10) {
    hasValueLessThanTen = true;
    break;
  }
}

Or, as suggested by @RobW, use Array.prototype.some to test if there exists at least one element that is less than 10. It will stop looping when some element that matches your function is found:

var hasValueLessThanTen = myArray.some(function (val) { 
  return val < 10;
});

How do I do a multi-line string in node.js?

Take a look at CoffeeScript: http://coffeescript.org

It supports multi-line strings, interpolation, array comprehensions and lots of other nice stuff.

How to read data from java properties file using Spring Boot

i would suggest the following way:

@PropertySource(ignoreResourceNotFound = true, value = "classpath:otherprops.properties")
@Controller
public class ClassA {
    @Value("${myName}")
    private String name;

    @RequestMapping(value = "/xyz")
    @ResponseBody
    public void getName(){
        System.out.println(name);
    }
}

Here your new properties file name is "otherprops.properties" and the property name is "myName". This is the simplest implementation to access properties file in spring boot version 1.5.8.

VBA - Select columns using numbers?

You can use resize like this:

For n = 1 To 5
    Columns(n).Resize(, 5).Select
    '~~> rest of your code
Next

In any Range Manipulation that you do, always keep at the back of your mind Resize and Offset property.

How to change the color of winform DataGridview header?

The way to do this is to set the EnableHeadersVisualStyles flag for the data grid view to False, and set the background colour via the ColumnHeadersDefaultCellStyle.BackColor property. For example, to set the background colour to blue, use the following (or set in the designer if you prefer):

_dataGridView.ColumnHeadersDefaultCellStyle.BackColor = Color.Blue;
_dataGridView.EnableHeadersVisualStyles = false;

If you do not set the EnableHeadersVisualStyles flag to False, then the changes you make to the style of the header will not take effect, as the grid will use the style from the current users default theme. The MSDN documentation for this property is here.

How to update json file with python

The issue here is that you've opened a file and read its contents so the cursor is at the end of the file. By writing to the same file handle, you're essentially appending to the file.

The easiest solution would be to close the file after you've read it in, then reopen it for writing.

with open("replayScript.json", "r") as jsonFile:
    data = json.load(jsonFile)

data["location"] = "NewPath"

with open("replayScript.json", "w") as jsonFile:
    json.dump(data, jsonFile)

Alternatively, you can use seek() to move the cursor back to the beginning of the file then start writing, followed by a truncate() to deal with the case where the new data is smaller than the previous.

with open("replayScript.json", "r+") as jsonFile:
    data = json.load(jsonFile)

    data["location"] = "NewPath"

    jsonFile.seek(0)  # rewind
    json.dump(data, jsonFile)
    jsonFile.truncate()

Getting the folder name from a path

DirectoryInfo does the job to strip directory name

string my_path = @"C:\Windows\System32";
DirectoryInfo dir_info = new DirectoryInfo(my_path);
string directory = dir_info.Name;  // System32

How can I create a simple index.html file which lists all files/directories?

Did you try to allow it for this directory via .htaccess?

Options +Indexes

I use this for some of my directories where directory listing is disabled by my provider

How to change the status bar background color and text color on iOS 7?

Swift code

            let statusBarView = UIView(frame: CGRect(x: 0, y: 0, width: view.width, height: 20.0))
            statusBarView.backgroundColor = UIColor.red
            self.navigationController?.view.addSubview(statusBarView)

How to get an Android WakeLock to work?

You just have to write this:

 private PowerManager.WakeLock wl;

    protected void onCreate(Bundle savedInstanceState) {
               super.onCreate(savedInstanceState);
            setContentView(R.layout.main);

            PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
            wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK, "DoNjfdhotDimScreen");
    }//End of onCreate

            @Override
        protected void onPause() {
            super.onPause();
            wl.release();
        }//End of onPause

        @Override
        protected void onResume() {
            super.onResume();
            wl.acquire();
        }//End of onResume

and then add permission in the manifest file

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

Now your activity will always be awake. You can do other things like w1.release() as per your requirement.

How to clone an InputStream?

Cloning an input stream might not be a good idea, because this requires deep knowledge about the details of the input stream being cloned. A workaround for this is to create a new input stream that reads from the same source again.

So using some Java 8 features this would look like this:

public class Foo {

    private Supplier<InputStream> inputStreamSupplier;

    public void bar() {
        procesDataThisWay(inputStreamSupplier.get());
        procesDataTheOtherWay(inputStreamSupplier.get());
    }

    private void procesDataThisWay(InputStream) {
        // ...
    }

    private void procesDataTheOtherWay(InputStream) {
        // ...
    }
}

This method has the positive effect that it will reuse code that is already in place - the creation of the input stream encapsulated in inputStreamSupplier. And there is no need to maintain a second code path for the cloning of the stream.

On the other hand, if reading from the stream is expensive (because a it's done over a low bandwith connection), then this method will double the costs. This could be circumvented by using a specific supplier that will store the stream content locally first and provide an InputStream for that now local resource.

MAC addresses in JavaScript

I concur with all the previous answers that it would be a privacy/security vulnerability if you would be able to do this directly from Javascript. There are two things I can think of:

Using Java (with a signed applet)
Using signed Javascript, which in FF (and Mozilla in general) gets higher privileges than normal JS (but it is fairly complicated to set up)

The 'Access-Control-Allow-Origin' header contains multiple values

I added

config.EnableCors(new EnableCorsAttribute(Properties.Settings.Default.Cors, "", ""))

as well as

app.UseCors(CorsOptions.AllowAll);

on the server. This results in two header entries. Just use the latter one and it works.

How do I calculate the percentage of a number?

$percentage = 50;
$totalWidth = 350;

$new_width = ($percentage / 100) * $totalWidth;

How to find the serial port number on Mac OS X?

I was able to screen using the device's name anyway so that wasn't the issue. I was actually just trying to find the port number, i.e. 5331, 5332 etc. I managed to find this by a trial and error process using an app called TCP2Serial from the app store on Mac OS X. It isn't free but that's fine as long as I know it works!

Worth the 99c :) http://itunes.apple.com/us/app/tcp2serial/id506186902?mt=12

How to remove listview all items

ListView operates based on the underlying data in the Adapter. In order to clear the ListView you need to do two things:

Clear the data that you set from adapter.
Refresh the view by calling notifyDataSetChanged

For example, see the skeleton of SampleAdapter below that extends the BaseAdapter


public class SampleAdapter extends BaseAdapter {

    ArrayList<String> data;

    public SampleAdapter() {
        this.data = new ArrayList<String>();
    }

    public int getCount() {
        return data.size();
    }

    public Object getItem(int position) {
        return data.get(position);
    }

    public long getItemId(int position) {
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        // your View
        return null;
    }
}

Here you have the ArrayList<String> data as the data for your Adapter. While you might not necessary use ArrayList, you will have something similar in your code to represent the data in your ListView

Next you provide a method to clear this data, the implementation of this method is to clear the underlying data structure


public void clearData() {
    // clear the data
    data.clear();
}

If you are using any subclass of Collection, they will have clear() method that you could use as above.

Once you have this method, you want to call clearData and notifyDataSetChanged on your onClick thus the code for onClick will look something like:


// listView is your instance of your ListView
SampleAdapter sampleAdapter = (SampleAdapter)listView.getAdapter();
sampleAdapter.clearData();

// refresh the View
sampleAdapter.notifyDataSetChanged();

How to get the last char of a string in PHP?

As of PHP 7.1.0, negative string offsets are also supported. So, if you keep up with the times, you can access the last character in the string like this:

$str[-1]

DEMO

At the request of a @mickmackusa, I supplement my answer with possible ways of application:

<?php

$str='abcdef';
var_dump($str[-2]); // => string(1) "e"

$str[-3]='.';
var_dump($str);     // => string(6) "abc.ef"

var_dump(isset($str[-4]));  // => bool(true)

var_dump(isset($str[-10])); // => bool(false)

PHP Using RegEx to get substring of a string

Unfortunately, you have a malformed url query string, so a regex technique is most appropriate. See what I mean.

There is no need for capture groups. Just match id= then forget those characters with \K, then isolate the following one or more digital characters.

Code (Demo)

$str = 'producturl.php?id=736375493?=tm';
echo preg_match('~id=\K\d+~', $str, $out) ? $out[0] : 'no match';

Output:

736375493

Adding options to a <select> using jQuery?

You can append and set the Value attribute with text:

$("#id").append($('<option></option>').attr("value", '').text(''));
$("#id").append($('<option></option>').attr("value", '4').text('Financial Institutions'));

How do I show running processes in Oracle DB?

This one shows SQL that is currently "ACTIVE":-

select S.USERNAME, s.sid, s.osuser, t.sql_id, sql_text
from v$sqltext_with_newlines t,V$SESSION s
where t.address =s.sql_address
and t.hash_value = s.sql_hash_value
and s.status = 'ACTIVE'
and s.username <> 'SYSTEM'
order by s.sid,t.piece
/

This shows locks. Sometimes things are going slow, but it's because it is blocked waiting for a lock:

select
  object_name, 
  object_type, 
  session_id, 
  type,         -- Type or system/user lock
  lmode,        -- lock mode in which session holds lock
  request, 
  block, 
  ctime         -- Time since current mode was granted
from
  v$locked_object, all_objects, v$lock
where
  v$locked_object.object_id = all_objects.object_id AND
  v$lock.id1 = all_objects.object_id AND
  v$lock.sid = v$locked_object.session_id
order by
  session_id, ctime desc, object_name
/

This is a good one for finding long operations (e.g. full table scans). If it is because of lots of short operations, nothing will show up.

COLUMN percent FORMAT 999.99 

SELECT sid, to_char(start_time,'hh24:mi:ss') stime, 
message,( sofar/totalwork)* 100 percent 
FROM v$session_longops
WHERE sofar/totalwork < 1
/

Allow only numbers to be typed in a textbox

With HTML5 you can do

<input type="number">

You can also use a regex pattern to limit the input text.

<input type="text" pattern="^[0-9]*$" />

What is the meaning of CTOR?

To expand a little more, there are two kinds of constructors: instance initializers (.ctor), type initializers (.cctor). Build the code below, and explore the IL code in ildasm.exe. You will notice that the static field 'b' will be initialized through .cctor() whereas the instance field will be initialized through .ctor()

internal sealed class CtorExplorer
{
   protected int a = 0;
   protected static int b = 0;
}

C# Convert string from UTF-8 to ISO-8859-1 (Latin1) H

Seems bit strange code. To get string from Utf8 byte stream all you need to do is:

string str = Encoding.UTF8.GetString(utf8ByteArray);

If you need to save iso-8859-1 byte stream to somewhere then just use: additional line of code for previous:

byte[] iso88591data = Encoding.GetEncoding("ISO-8859-1").GetBytes(str);

Updating an object with setState in React

You can try with this: (Note: name of input tag === field of object)

<input name="myField" type="text" 
      value={this.state.myObject.myField} 
     onChange={this.handleChangeInpForm}>
</input>

-----------------------------------------------------------
handleChangeInpForm = (e) => {
   let newObject = this.state.myObject;
   newObject[e.target.name] = e.target.value;
   this.setState({
     myObject: newObject 
   })
}

Getting attribute using XPath

Here is the snippet of getting the attribute value of "lang" with XPath and VTD-XML.

import com.ximpleware.*;
public class getAttrVal {
    public static void main(String s[]) throws VTDException{
        VTDGen vg = new VTDGen();
        if (!vg.parseFile("input.xml", false)){
            return ;
        }
        VTDNav vn = vg.getNav();
        AutoPilot ap = new AutoPilot(vn);
        ap.selectXPath("/bookstore/book/title/@lang");
        System.out.println(" lang's value is ===>"+ap.evalXPathToString());
    }
}

How to monitor Java memory usage?

You can take a look at stagemonitor. It is a open source java (web) application performance monitor. It captures response time metrics, JVM metrics, request details (including a call stack captured by the request profiler) and more. The overhead is very low.

Optionally, you can use the great timeseries database graphite with it to store a long history of datapoints that you can look at with fancy dashboards.

Example: JVM Memory Dashboard

Take a look at the project website to see screenshots, feature descriptions and documentation.

Note: I am the developer of stagemonitor

Capturing URL parameters in request.GET

These queries are currently done in two ways. If you want to access the query parameters (GET) you can query the following:

http://myserver:port/resource/?status=1

request.query_params.get('status', None) => 1

If you want to access the parameters passed by POST, you need to access this way:

request.data.get('role', None)

Accessing the dictionary (QueryDict) with 'get()', you can set a default value. In the cases above, if 'status' or 'role' are not informed, the values ??are None.

Save and load weights in keras

Since this question is quite old, but still comes up in google searches, I thought it would be good to point out the newer (and recommended) way to save Keras models. Instead of saving them using the older h5 format like has been shown before, it is now advised to use the SavedModel format, which is actually a dictionary that contains both the model configuration and the weights.

More information can be found here: https://www.tensorflow.org/guide/keras/save_and_serialize

The snippets to save & load can be found below:

model.fit(test_input, test_target)
# Calling save('my_model') creates a SavedModel folder 'my_model'.
model.save('my_model')

# It can be used to reconstruct the model identically.
reconstructed_model = keras.models.load_model('my_model')

A sample output of this :

How to insert date values into table

Since dob is DATE data type, you need to convert the literal to DATE using TO_DATE and the proper format model. The syntax is:

TO_DATE('<date_literal>', '<format_model>')

For example,

SQL> CREATE TABLE t(dob DATE);

Table created.

SQL> INSERT INTO t(dob) VALUES(TO_DATE('17/12/2015', 'DD/MM/YYYY'));

1 row created.

SQL> COMMIT;

Commit complete.

SQL> SELECT * FROM t;

DOB
----------
17/12/2015

A DATE data type contains both date and time elements. If you are not concerned about the time portion, then you could also use the ANSI Date literal which uses a fixed format 'YYYY-MM-DD' and is NLS independent.

For example,

SQL> INSERT INTO t(dob) VALUES(DATE '2015-12-17');

1 row created.

How schedule build in Jenkins?

H H(5-21)/2 * * 1-5

MON-FRI build every 2 hour between

Laravel use same form for create and edit

Another clean method with a small controller, two views and a partial view :

UsersController.php

public function create()
{
    return View::('create');
}    

public function edit($id)
{
    $user = User::find($id);
    return View::('edit')->with(compact('user'));
}

create.blade.php

{{ Form::open( array( 'route' => ['users.index'], 'role' => 'form' ) ) }}
    @include('_fields')
{{ Form::close() }}

edit.blade.php

{{ Form::model( $user, ['route' => ['users.update', $user->id], 'method' => 'put', 'role' => 'form'] ) }}
    @include('_fields')
{{ Form::close() }}

_fields.blade.php

{{ Form::text('fieldname1') }}
{{ Form::text('fieldname2') }}
{{ Form::button('Save', ['type' => 'submit']) }}

How do I make this file.sh executable via double click?

You can just tell Finder to open the .sh file in Terminal:

Select the file
Get Info (cmd-i) on it
In the "Open with" section, choose "Other…" in the popup menu
Choose Terminal as the application

This will have the exact same effect as renaming it to .command except… you don't have to rename it :)

java.lang.OutOfMemoryError: bitmap size exceeds VM budget - Android

I too am frustrated by the outofmemory bug. And yes, I too found that this error pops up a lot when scaling images. At first I tried creating image sizes for all densities, but I found this substantially increased the size of my app. So I'm now just using one image for all densities and scaling my images.

My application would throw an outofmemory error whenever the user went from one activity to another. Setting my drawables to null and calling System.gc() didn't work, neither did recycling my bitmapDrawables with getBitMap().recycle(). Android would continue to throw the outofmemory error with the first approach, and it would throw a canvas error message whenever it tried using a recycled bitmap with the second approach.

I took an even third approach. I set all views to null and the background to black. I do this cleanup in my onStop() method. This is the method that gets called as soon as the activity is no longer visible. If you do it in the onPause() method, users will see a black background. Not ideal. As for doing it in the onDestroy() method, there is no guarantee that it will get called.

To prevent a black screen from occurring if the user presses the back button on the device, I reload the activity in the onRestart() method by calling the startActivity(getIntent()) and then finish() methods.

Note: it's not really necessary to change the background to black.

How to put a div in center of browser using CSS?

.center {
  margin: auto;
  margin-top: 15vh;
}

Should do the trick

How to automatically convert strongly typed enum into int?

No. There is no natural way.

In fact, one of the motivations behind having strongly typed enum class in C++11 is to prevent their silent conversion to int.

Resolving require paths with webpack

In case anyone else runs into this problem, I was able to get it working like this:

var path = require('path');
// ...
resolve: {
  root: [path.resolve(__dirname, 'src'), path.resolve(__dirname, 'node_modules')],
  extensions: ['', '.js']
};

where my directory structure is:

.
+-- dist
+-- node_modules
+-- package.json
+-- README.md
+-- src
¦   +-- components
¦   +-- index.html
¦   +-- main.js
¦   +-- styles
+-- webpack.config.js

Then from anywhere in the src directory I can call:

import MyComponent from 'components/MyComponent';

How to get content body from a httpclient call?

If you are not wanting to use async you can add .Result to force the code to execute synchronously:

private string GetResponseString(string text)
{
    var httpClient = new HttpClient();

    var parameters = new Dictionary<string, string>();
    parameters["text"] = text;

    var response = httpClient.PostAsync(BaseUri, new FormUrlEncodedContent(parameters)).Result;
    var contents = response.Content.ReadAsStringAsync().Result;

    return contents;
 }

Sending event when AngularJS finished loading

If you don't use ngRoute module, i.e. you don't have $viewContentLoaded event.

You can use another directive method:

    angular.module('someModule')
        .directive('someDirective', someDirective);

    someDirective.$inject = ['$rootScope', '$timeout']; //Inject services

    function someDirective($rootScope, $timeout){
        return {
            restrict: "A",
            priority: Number.MIN_SAFE_INTEGER, //Lowest priority
            link    : function(scope, element, attr){
                $timeout(
                    function(){
                        $rootScope.$emit("Some:event");
                    }
                );
            }
        };
    }

Accordingly to trusktr's answer it has lowest priority. Plus $timeout will cause Angular to run through an entire event loop before callback execution.

$rootScope used, because it allow to place directive in any scope of the application and notify only necessary listeners.

$rootScope.$emit will fire an event for all $rootScope.$on listeners only. The interesting part is that $rootScope.$broadcast will notify all $rootScope.$on as well as $scope.$on listeners Source

Skip the headers when editing a csv file using Python

Inspired by Martijn Pieters' response.

In case you only need to delete the header from the csv file, you can work more efficiently if you write using the standard Python file I/O library, avoiding writing with the CSV Python library:

with open("tmob_notcleaned.csv", "rb") as infile, open("tmob_cleaned.csv", "wb") as outfile:
   next(infile)  # skip the headers
   outfile.write(infile.read())

Remove pattern from string with gsub

as.numeric(gsub(pattern=".*_", replacement = '', a)
[1] 5 7

How to correctly use Html.ActionLink with ASP.NET MVC 4 Areas

How I redirect to an area is add it as a parameter

@Html.Action("Action", "Controller", new { area = "AreaName" })

for the href portion of a link I use

@Url.Action("Action", "Controller", new { area = "AreaName" })

What is the size of ActionBar in pixels?

To retrieve the height of the ActionBar in XML, just use

?android:attr/actionBarSize

or if you're an ActionBarSherlock or AppCompat user, use this

?attr/actionBarSize

If you need this value at runtime, use this

final TypedArray styledAttributes = getContext().getTheme().obtainStyledAttributes(
                    new int[] { android.R.attr.actionBarSize });
mActionBarSize = (int) styledAttributes.getDimension(0, 0);
styledAttributes.recycle();

If you need to understand where this is defined:

The attribute name itself is defined in the platform's /res/values/attrs.xml
The platform's themes.xml picks this attribute and assigns a value to it.
The value assigned in step 2 depends on different device sizes, which are defined in various dimens.xml files in the platform, ie. core/res/res/values-sw600dp/dimens.xml

While loop in batch

It was very useful for me i have used in the following way to add user in active directory:

:: This file is used to automatically add list of user to activedirectory
:: First ask for username,pwd,dc details and run in loop
:: dsadd user cn=jai,cn=users,dc=mandrac,dc=com -pwd `1q`1q`1q`1q

@echo off
setlocal enableextensions enabledelayedexpansion
set /a "x = 1"
set /p lent="Enter how many Users you want to create : "
set /p Uname="Enter the user name which will be rotated with number ex:ram then ram1 ..etc : "
set /p DcName="Enter the DC name ex:mandrac : "
set /p Paswd="Enter the password you want to give to all the users : "

cls

:while1

if %x% leq %lent% (

    dsadd user cn=%Uname%%x%,cn=users,dc=%DcName%,dc=com -pwd %Paswd%
    echo User %Uname%%x% with DC %DcName% is created
    set /a "x = x + 1"
    goto :while1
)

endlocal

Check if number is decimal

the easy way to find either posted value is integer and float so this will help you

$postedValue = $this->input->post('value');
if(is_numeric( $postedValue ) && floor( $postedValue ))
{
    echo 'success';
}
else
{
   echo 'unsuccess';
}

if you give 10 or 10.5 or 10.0 the result will be success if you define any character or specail character without dot it will give unsuccess

Display Image On Text Link Hover CSS Only

It can be done using CSS alone. It works perfect on my machine in Firefox, Chrome and Opera browser under Ubuntu 12.04.

CSS :

.hover_img a { position:relative; }
.hover_img a span { position:absolute; display:none; z-index:99; }
.hover_img a:hover span { display:block; }

HTML :

<div class="hover_img">
     <a href="#">Show Image<span><img src="images/01.png" alt="image" height="100" /></span></a>
</div>

Reading a binary input stream into a single byte array in Java

Max value for array index is Integer.MAX_INT - it's around 2Gb (2^31 / 2 147 483 647). Your input stream can be bigger than 2Gb, so you have to process data in chunks, sorry.

        InputStream is;
        final byte[] buffer = new byte[512 * 1024 * 1024]; // 512Mb
        while(true) {
            final int read = is.read(buffer);
            if ( read < 0 ) {
                break;
            }
            // do processing 
        }

The maximum recursion 100 has been exhausted before statement completion

it is just a sample to avoid max recursion error. we have to use option (maxrecursion 365); or option (maxrecursion 0);

DECLARE @STARTDATE datetime; 
DECLARE @EntDt datetime; 
set @STARTDATE = '01/01/2009';  
set @EntDt = '12/31/2009'; 
declare @dcnt int; 
;with DateList as   
 (   
    select @STARTDATE DateValue   
    union all   
    select DateValue + 1 from    DateList      
    where   DateValue + 1 < convert(VARCHAR(15),@EntDt,101)   
 )   
  select count(*) as DayCnt from (   
  select DateValue,DATENAME(WEEKDAY, DateValue ) as WEEKDAY from DateList
  where DATENAME(WEEKDAY, DateValue ) not IN ( 'Saturday','Sunday' )     
  )a
option (maxrecursion 365);

How can my iphone app detect its own version number?

Read the info.plist file of your app and get the value for key CFBundleShortVersionString. Reading info.plist will give you an NSDictionary object

How to keep :active css style after clicking an element

Combine JS & CSS :

button{
  /* 1st state */
}

button:hover{
  /* hover state */
}

button:active{
  /* click state */
}

button.active{
  /* after click state */
}


jQuery('button').click(function(){
   jQuery(this).toggleClass('active');
});

How can I get a file's size in C++?

While not necessarily the most popular method, I've heard that the ftell, fseek method may not always give accurate results in some circumstances. Specifically, if an already opened file is used and the size needs to be worked out on that and it happens to be opened as a text file, then it's going to give out wrong answers.

The following methods should always work as stat is part of the c runtime library on Windows, Mac and Linux.

long GetFileSize(std::string filename)
{
    struct stat stat_buf;
    int rc = stat(filename.c_str(), &stat_buf);
    return rc == 0 ? stat_buf.st_size : -1;
}

or 

long FdGetFileSize(int fd)
{
    struct stat stat_buf;
    int rc = fstat(fd, &stat_buf);
    return rc == 0 ? stat_buf.st_size : -1;
}

On some systems there is also a stat64/fstat64. So if you need this for very large files you may want to look at using those.

What's the difference between echo, print, and print_r in PHP?

echo : echo is a language construct where there is not required to use parentheses with it and it can take any number of parameters and return void.

   void echo (param1,param2,param3.....);

   Example: echo "test1","test2,test3";

print : it is a language construct where there is not required to use parentheses it just take one parameter and return

    1 always.

           int print(param1);

           print "test1";
           print "test1","test2"; // It will give syntax error

prinf : It is a function which takes atleast one string and format style and returns length of output string.

    int printf($string,$s);

    $s= "Shailesh";
    $i= printf("Hello %s how are you?",$s);    
    echo $i;

    Output : Hello Shailesh how are you?
             27



   echo returns void so its execution is faster than print and printf

Set folder browser dialog start location

Just set the SelectedPath property before calling ShowDialog.

fdbLocation.SelectedPath = myFolder;

Stretch image to fit full container width bootstrap

First of all if the size of the image is smaller than the container, then only "img-fluid" class will not solve your problem. you have to set the width of image to 100%, for that you can use Bootstrap class "w-100". keep in mind that "container-fluid" and "col-12" class sets left and right padding to 15px and "row" class sets left and right margin to "-15px" by default. make sure to set them to 0.

Note: "px-0" is a bootstrap class which sets left and right padding to 0 and
"mx-0" is a bootstrap class which sets left and right margin to 0

P.S. i am using Bootstrap 4.0 version.

 <div class="container-fluid px-0">
        <div class="row mx-0">
            <div class="col-12 px-0">
            <img src="images/top.jpg" class="img-fluid w-100">
            </div>
        </div>
    </div>

Solve error javax.mail.AuthenticationFailedException

https://www.google.com/settings/security/lesssecureapps
go to your account and turn on the security it will work

Query grants for a table in postgres

Adding on to @shruti's answer

To query grants for all tables in a schema for a given user

select a.tablename, 
       b.usename, 
       HAS_TABLE_PRIVILEGE(usename,tablename, 'select') as select,
       HAS_TABLE_PRIVILEGE(usename,tablename, 'insert') as insert, 
       HAS_TABLE_PRIVILEGE(usename,tablename, 'update') as update, 
       HAS_TABLE_PRIVILEGE(usename,tablename, 'delete') as delete, 
       HAS_TABLE_PRIVILEGE(usename,tablename, 'references') as references 
from pg_tables a, 
     pg_user b 
where schemaname='your_schema_name' 
      and b.usename='your_user_name' 
order by tablename;

How do you serialize a model instance in Django?

There is a good answer for this and I'm surprised it hasn't been mentioned. With a few lines you can handle dates, models, and everything else.

Make a custom encoder that can handle models:

from django.forms import model_to_dict
from django.core.serializers.json import DjangoJSONEncoder
from django.db.models import Model

class ExtendedEncoder(DjangoJSONEncoder):

    def default(self, o):

        if isinstance(o, Model):
            return model_to_dict(o)

        return super().default(o)

Now use it when you use json.dumps

json.dumps(data, cls=ExtendedEncoder)

Now models, dates and everything can be serialized and it doesn't have to be in an array or serialized and unserialized. Anything you have that is custom can just be added to the default method.

You can even use Django's native JsonResponse this way:

from django.http import JsonResponse

JsonResponse(data, encoder=ExtendedEncoder)

How do I flush the cin buffer?

I would prefer the C++ size constraints over the C versions:

// Ignore to the end of file
cin.ignore(std::numeric_limits<std::streamsize>::max())

// Ignore to the end of line
cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n')

How to make inactive content inside a div?

Without using an overlay, you can use pointer-events: none on the div in CSS, but this does not work in IE or Opera.

div.disabled
{
  pointer-events: none;

  /* for "disabled" effect */
  opacity: 0.5;
  background: #CCC;
}

Reference

window.onload vs document.onload

window.onload and onunload are shortcuts to document.body.onload and document.body.onunload

document.onload and onload handler on all html tag seems to be reserved however never triggered

'onload' in document -> true

Can I add jars to maven 2 build classpath without installing them?

Problems of popular approaches

Most of the answers you'll find around the internet will suggest you to either install the dependency to your local repository or specify a "system" scope in the pom and distribute the dependency with the source of your project. But both of these solutions are actually flawed.

Why you shouldn't apply the "Install to Local Repo" approach

When you install a dependency to your local repository it remains there. Your distribution artifact will do fine as long as it has access to this repository. The problem is in most cases this repository will reside on your local machine, so there'll be no way to resolve this dependency on any other machine. Clearly making your artifact depend on a specific machine is not a way to handle things. Otherwise this dependency will have to be locally installed on every machine working with that project which is not any better.

Why you shouldn't apply the "System Scope" approach

The jars you depend on with the "System Scope" approach neither get installed to any repository or attached to your target packages. That's why your distribution package won't have a way to resolve that dependency when used. That I believe was the reason why the use of system scope even got deprecated. Anyway you don't want to rely on a deprecated feature.

The static in-project repository solution

After putting this in your pom:

<repository>
    <id>repo</id>
    <releases>
        <enabled>true</enabled>
        <checksumPolicy>ignore</checksumPolicy>
    </releases>
    <snapshots>
        <enabled>false</enabled>
    </snapshots>
    <url>file://${project.basedir}/repo</url>
</repository>

for each artifact with a group id of form x.y.z Maven will include the following location inside your project dir in its search for artifacts:

repo/
| - x/
|   | - y/
|   |   | - z/
|   |   |   | - ${artifactId}/
|   |   |   |   | - ${version}/
|   |   |   |   |   | - ${artifactId}-${version}.jar

To elaborate more on this you can read this blog post.

Use Maven to install to project repo

Instead of creating this structure by hand I recommend to use a Maven plugin to install your jars as artifacts. So, to install an artifact to an in-project repository under repo folder execute:

mvn install:install-file -DlocalRepositoryPath=repo -DcreateChecksum=true -Dpackaging=jar -Dfile=[your-jar] -DgroupId=[...] -DartifactId=[...] -Dversion=[...]

If you'll choose this approach you'll be able to simplify the repository declaration in pom to:

<repository>
    <id>repo</id>
    <url>file://${project.basedir}/repo</url>
</repository>

A helper script

Since executing installation command for each lib is kinda annoying and definitely error prone, I've created a utility script which automatically installs all the jars from a lib folder to a project repository, while automatically resolving all metadata (groupId, artifactId and etc.) from names of files. The script also prints out the dependencies xml for you to copy-paste in your pom.

Include the dependencies in your target package

When you'll have your in-project repository created you'll have solved a problem of distributing the dependencies of the project with its source, but since then your project's target artifact will depend on non-published jars, so when you'll install it to a repository it will have unresolvable dependencies.

To beat this problem I suggest to include these dependencies in your target package. This you can do with either the Assembly Plugin or better with the OneJar Plugin. The official documentaion on OneJar is easy to grasp.

How to rename files and folder in Amazon S3?

You can either use AWS CLI or s3cmd command to rename the files and folders in AWS S3 bucket.

Using S3cmd, use the following syntax to rename a folder,

s3cmd --recursive mv s3://<s3_bucketname>/<old_foldername>/ s3://<s3_bucketname>/<new_folder_name>

Using AWS CLI, use the following syntax to rename a folder,

aws s3 --recursive mv s3://<s3_bucketname>/<old_foldername>/ s3://<s3_bucketname>/<new_folder_name>

Footnotes for tables in LaTeX

In tables I have used \footnotetext.

specifying goal in pom.xml

Add the goal like -

 <build>
        <defaultGoal>install</defaultGoal>
        <!-- Source directory configuration -->
        <sourceDirectory>src</sourceDirectory>
</build>

This will solve the issue

How can VBA connect to MySQL database in Excel?

This piece of vba worked for me:

Sub connect()
    Dim Password As String
    Dim SQLStr As String
    'OMIT Dim Cn statement
    Dim Server_Name As String
    Dim User_ID As String
    Dim Database_Name As String
    'OMIT Dim rs statement

    Set rs = CreateObject("ADODB.Recordset") 'EBGen-Daily
    Server_Name = Range("b2").Value
    Database_name = Range("b3").Value ' Name of database
    User_ID = Range("b4").Value 'id user or username
    Password = Range("b5").Value 'Password

    SQLStr = "SELECT * FROM ComputingNotesTable"

    Set Cn = CreateObject("ADODB.Connection") 'NEW STATEMENT
    Cn.Open "Driver={MySQL ODBC 5.2.2 Driver};Server=" & _ 
            Server_Name & ";Database=" & Database_Name & _
            ";Uid=" & User_ID & ";Pwd=" & Password & ";"

    rs.Open SQLStr, Cn, adOpenStatic

    Dim myArray()

    myArray = rs.GetRows()

    kolumner = UBound(myArray, 1)
    rader = UBound(myArray, 2)

    For K = 0 To kolumner ' Using For loop data are displayed
        Range("a5").Offset(0, K).Value = rs.Fields(K).Name
        For R = 0 To rader
           Range("A5").Offset(R + 1, K).Value = myArray(K, R)
        Next
    Next

    rs.Close
    Set rs = Nothing
    Cn.Close
    Set Cn = Nothing
End Sub

"No resource identifier found for attribute 'showAsAction' in package 'android'"

go to gradle and then to app.buildgradle then set compileSDKVersion to 21 and then if necessary the android studio will download some files

What is the difference between ndarray and array in numpy?

numpy.ndarray() is a class, while numpy.array() is a method / function to create ndarray.

In numpy docs if you want to create an array from ndarray class you can do it with 2 ways as quoted:

1- using array(), zeros() or empty() methods: Arrays should be constructed using array, zeros or empty (refer to the See Also section below). The parameters given here refer to a low-level method (ndarray(…)) for instantiating an array.

2- from ndarray class directly: There are two modes of creating an array using __new__: If buffer is None, then only shape, dtype, and order are used. If buffer is an object exposing the buffer interface, then all keywords are interpreted.

The example below gives a random array because we didn't assign buffer value:

np.ndarray(shape=(2,2), dtype=float, order='F', buffer=None)

array([[ -1.13698227e+002,   4.25087011e-303],
       [  2.88528414e-306,   3.27025015e-309]])         #random

another example is to assign array object to the buffer example:

>>> np.ndarray((2,), buffer=np.array([1,2,3]),
...            offset=np.int_().itemsize,
...            dtype=int) # offset = 1*itemsize, i.e. skip first element
array([2, 3])

from above example we notice that we can't assign a list to "buffer" and we had to use numpy.array() to return ndarray object for the buffer

Conclusion: use numpy.array() if you want to make a numpy.ndarray() object"

How to destroy a JavaScript object?

You could put all of your code under one namespace like this:

var namespace = {};

namespace.someClassObj = {};

delete namespace.someClassObj;

Using the delete keyword will delete the reference to the property, but on the low level the JavaScript garbage collector (GC) will get more information about which objects to be reclaimed.

You could also use Chrome Developer Tools to get a memory profile of your app, and which objects in your app are needing to be scaled down.

What's the best way to parse a JSON response from the requests library?

You can use json.loads:

import json
import requests

response = requests.get(...)
json_data = json.loads(response.text)

This converts a given string into a dictionary which allows you to access your JSON data easily within your code.

Or you can use @Martijn's helpful suggestion, and the higher voted answer, response.json().

Get time of specific timezone

before you get too excited this was written in 2011

if I were to do this these days I would use Intl.DateTimeFormat. Here is a link to give you an idea of what type of support this had in 2011

original answer now (very) outdated

Date.getTimezoneOffset()

The getTimezoneOffset() method returns the time difference between Greenwich Mean Time (GMT) and local time, in minutes.

For example, If your time zone is GMT+2, -120 will be returned.

Note: This method is always used in conjunction with a Date object.

var d = new Date()
var gmtHours = -d.getTimezoneOffset()/60;
document.write("The local time zone is: GMT " + gmtHours);
//output:The local time zone is: GMT 11

Check if string contains only digits

This is what you want

function isANumber(str){
  return !/\D/.test(str);
}

Google Maps API v3: InfoWindow not sizing correctly

After losing time and reading for a while, I just wanted something simple, this css worked for my requirements.

.gm-style-iw > div { overflow: hidden !important; }

Also is not an instant solution but starring/commenting on the issue might make them fix it, as they believe it is fixed: http://code.google.com/p/gmaps-api-issues/issues/detail?id=5713

Example using Hyperlink in WPF

IMHO the simplest way is to use new control inherited from Hyperlink:

/// <summary>
/// Opens <see cref="Hyperlink.NavigateUri"/> in a default system browser
/// </summary>
public class ExternalBrowserHyperlink : Hyperlink
{
    public ExternalBrowserHyperlink()
    {
        RequestNavigate += OnRequestNavigate;
    }

    private void OnRequestNavigate(object sender, RequestNavigateEventArgs e)
    {
        Process.Start(new ProcessStartInfo(e.Uri.AbsoluteUri));
        e.Handled = true;
    }
}

HighCharts Hide Series Name from the Legend

Set showInLegend to false.

series: [{
            showInLegend: false,
            name: 'Series',
            data: value                
        }]

Max parallel http connections in a browser?

The 2 concurrent requests is an intentional part of the design of many browsers. There is a standard out there that "good http clients" adhere to on purpose. Check out this RFC to see why.

How to check if command line tools is installed

From a programmatic perspective the Homebrew folks have a check for the existence of various files to determine if the command line tools are installed. Currently it always checks for /Library/Developer/CommandLineTools/usr/bin/git and will also check for /usr/include/iconv.h if the OS version is 10.13 or below.

Rails: How does the respond_to block work?

What type of variable is format?

From a java POV, format is an implemtation of an anonymous interface. This interface has one method named for each mime type. When you invoke one of those methods (passing it a block), then if rails feels that the user wants that content type, then it will invoke your block.

The twist, of course, is that this anonymous glue object doesn't actually implement an interface - it catches the method calls dynamically and works out if its the name of a mime type that it knows about.

Personally, I think it looks weird: the block that you pass in is executed. It would make more sense to me to pass in a hash of format labels and blocks. But - that's how its done in RoR, it seems.

invalid target release: 1.7

Other than setting JAVA_HOME environment variable, you got to make sure you are using the correct JDK in your Maven run configuration. Go to Run -> Run Configuration, select your Maven Build configuration, go to JRE tab and set the correct Runtime JRE.

Maven run configuration

ASP.NET Core Web API Authentication

To use this only for specific controllers for example use this:

app.UseWhen(x => (x.Request.Path.StartsWithSegments("/api", StringComparison.OrdinalIgnoreCase)), 
            builder =>
            {
                builder.UseMiddleware<AuthenticationMiddleware>();
            });

Address validation using Google Maps API

Google's geocoding api does what want you want. As Xerus points out, as long as you are not using the geocoded points on a non-google Map, you should be good (terms of service). Specifically,

3.1 Use without a Google Map. Customer may use Google Maps Content from the Geocoding API in Customer Applications without a corresponding Google Map.


3.3 No use with a non-Google map.  Customer must not use Google Maps Content from the Geocoding API in conjunction with a non-Google map.

How do I get the SharedPreferences from a PreferenceActivity in Android?

if you have a checkbox and you would like to fetch it's value ie true / false in any java file--

Use--

Context mContext;
boolean checkFlag;

checkFlag=PreferenceManager.getDefaultSharedPreferences(mContext).getBoolean(KEY,DEFAULT_VALUE);`

Finding median of list in Python

import numpy as np
def get_median(xs):
        mid = len(xs) // 2  # Take the mid of the list
        if len(xs) % 2 == 1: # check if the len of list is odd
            return sorted(xs)[mid] #if true then mid will be median after sorting
        else:
            #return 0.5 * sum(sorted(xs)[mid - 1:mid + 1])
            return 0.5 * np.sum(sorted(xs)[mid - 1:mid + 1]) #if false take the avg of mid
print(get_median([7, 7, 3, 1, 4, 5]))
print(get_median([1,2,3, 4,5]))

How do you do block comments in YAML?

In Azure Devops browser(pipeline yaml editor),

Ctrl + K + C Comment Block

Ctrl + K + U Uncomment Block

There also a 'Toggle Block Comment' option but this did not work for me.

There are other 'wierd' ways too: right click to see 'Command Palette' or F1

Then choose a cursor option.

Now it is just a matter of #

or even smarter [Ctrl + k] + [Ctrl + c]

Adding a css class to select using @Html.DropDownList()

You can simply do this:

@Html.DropDownList("PriorityID", null, new { @class="form-control"})

How do I check if a number is a palindrome?

For any given number:

n = num;
rev = 0;
while (num > 0)
{
    dig = num % 10;
    rev = rev * 10 + dig;
    num = num / 10;
}

If n == rev then num is a palindrome:

cout << "Number " << (n == rev ? "IS" : "IS NOT") << " a palindrome" << endl;

setting JAVA_HOME & CLASSPATH in CentOS 6

Search here for centos jre install all users:

The easiest way to set an environment variable in CentOS is to use export as in

$> export JAVA_HOME=/usr/java/jdk.1.5.0_12

$> export PATH=$PATH:$JAVA_HOME

However, variables set in such a manner are transient i.e. they will disappear the moment you exit the shell. Obviously this is not helpful when setting environment variables that need to persist even when the system reboots. In such cases, you need to set the variables within the system wide profile. In CentOS (I’m using v5.2), the folder /etc/profile.d/ is the recommended place to add customizations to the system profile. For example, when installing the Sun JDK, you might need to set the JAVA_HOME and JRE_HOME environment variables. In this case: Create a new file called java.sh

vim /etc/profile.d/java.sh

Within this file, initialize the necessary environment variables

export JRE_HOME=/usr/java/jdk1.5.0_12/jre
export PATH=$PATH:$JRE_HOME/bin

export JAVA_HOME=/usr/java/jdk1.5.0_12
export JAVA_PATH=$JAVA_HOME

export PATH=$PATH:$JAVA_HOME/bin

Now when you restart your machine, the environment variables within java.sh will be automatically initialized (checkout /etc/profile if you are curious how the files in /etc/profile.d/ are loaded).

PS: If you want to load the environment variables within java.sh without having to restart the machine, you can use the source command as in:

$> source java.sh

Python unicode equal comparison failed

You may use the == operator to compare unicode objects for equality.

>>> s1 = u'Hello'
>>> s2 = unicode("Hello")
>>> type(s1), type(s2)
(<type 'unicode'>, <type 'unicode'>)
>>> s1==s2
True
>>> 
>>> s3='Hello'.decode('utf-8')
>>> type(s3)
<type 'unicode'>
>>> s1==s3
True
>>>

But, your error message indicates that you aren't comparing unicode objects. You are probably comparing a unicode object to a str object, like so:

>>> u'Hello' == 'Hello'
True
>>> u'Hello' == '\x81\x01'
__main__:1: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal
False

See how I have attempted to compare a unicode object against a string which does not represent a valid UTF8 encoding.

Your program, I suppose, is comparing unicode objects with str objects, and the contents of a str object is not a valid UTF8 encoding. This seems likely the result of you (the programmer) not knowing which variable holds unicide, which variable holds UTF8 and which variable holds the bytes read in from a file.

I recommend http://nedbatchelder.com/text/unipain.html, especially the advice to create a "Unicode Sandwich."

Create a date time with month and day only, no year

There is no such thing like a DateTime without a year!

From what I gather your design is a bit strange:

I would recommend storing a "start" (DateTime including year for the FIRST occurence) and a value which designates how to calculate the next event... this could be for example a TimeSpan or some custom structure esp. since "every year" can mean that the event occurs on a specific date and would not automatically be the same as saysing that it occurs in +365 days.

After the event occurs you calculate the next and store that etc.

Jquery UI datepicker. Disable array of Dates

If you also want to block Sundays (or other days) as well as the array of dates, I use this code:

jQuery(function($){

    var disabledDays = [
       "27-4-2016", "25-12-2016", "26-12-2016",
       "4-4-2017", "5-4-2017", "6-4-2017", "6-4-2016", "7-4-2017", "8-4-2017", "9-4-2017"
    ];

   //replace these with the id's of your datepickers
   $("#id-of-first-datepicker,#id-of-second-datepicker").datepicker({
      beforeShowDay: function(date){
         var day = date.getDay();
         var string = jQuery.datepicker.formatDate('d-m-yy', date);
         var isDisabled = ($.inArray(string, disabledDays) != -1);

         //day != 0 disables all Sundays
         return [day != 0 && !isDisabled];
      }
   });
});

array filter in python?

No, there is no build in function in python to do this, because simply:

set(A)- set(subset_of_A)

will provide you the answer.

std::queue iteration

you can save the original queue to a temporary queue. Then you simply do your normal pop on the temporary queue to go through the original one, for example:

queue tmp_q = original_q; //copy the original queue to the temporary queue

while (!tmp_q.empty())
{
    q_element = tmp_q.front();
    std::cout << q_element <<"\n";
    tmp_q.pop();
}

At the end, the tmp_q will be empty but the original queue is untouched.

Blocking device rotation on mobile web pages

New API's are developing (and are currently available)!

screen.orientation.lock();   // webkit only

and

screen.lockOrientation("orientation");

Where "orientation" can be any of the following:

portrait-primary - It represents the orientation of the screen when it is in its primary portrait mode. A screen is considered in its primary portrait mode if the device is held in its normal position and that position is in portrait, or if the normal position of the device is in landscape and the device held turned by 90° clockwise. The normal position is device dependant.

portrait-secondary - It represents the orientation of the screen when it is in its secondary portrait mode. A screen is considered in its secondary portrait mode if the device is held 180° from its normal position and that position is in portrait, or if the normal position of the device is in landscape and the device held is turned by 90° anticlockwise. The normal position is device dependant.

landscape-primary - It represents the orientation of the screen when it is in its primary landscape mode. A screen is considered in its primary landscape mode if the device is held in its normal position and that position is in landscape, or if the normal position of the device is in portrait and the device held is turned by 90° clockwise. The normal position is device dependant.

landscape-secondary - It represents the orientation of the screen when it is in its secondary landscape mode. A screen is considered in its secondary landscape mode if the device held is 180° from its normal position and that position is in landscape, or if the normal position of the device is in portrait and the device held is turned by 90° anticlockwise. The normal position is device dependant.

portrait - It represents both portrait-primary and portrait-secondary.

landscape - It represents both landscape-primary and landscape-secondary.

default - It represents either portrait-primary and landscape-primary depends on natural orientation of devices. For example, if the panel resolution is 1280*800, default will make it landscape, if the resolution is 800*1280, default will make it to portrait.

Mozilla recommends adding a lockOrientationUniversal to screen to make it more cross-browser compatible.

screen.lockOrientationUniversal = screen.lockOrientation || screen.mozLockOrientation || screen.msLockOrientation;

Go here for more info: https://developer.mozilla.org/en-US/docs/Web/API/Screen/lockOrientation

Message Queue vs. Web Services?

Message queues are ideal for requests which may take a long time to process. Requests are queued and can be processed offline without blocking the client. If the client needs to be notified of completion, you can provide a way for the client to periodically check the status of the request.

Message queues also allow you to scale better across time. It improves your ability to handle bursts of heavy activity, because the actual processing can be distributed across time.

Note that message queues and web services are orthogonal concepts, i.e. they are not mutually exclusive. E.g. you can have a XML based web service which acts as an interface to a message queue. I think the distinction your looking for is Message Queues versus Request/Response, the latter is when the request is processed synchronously.

Disable eslint rules for folder

YAML version :

overrides:
  - files: *-tests.js
    rules:
      no-param-reassign: 0

Example of specific rules for mocha tests :

You can also set a specific env for a folder, like this :

overrides:
  - files: test/*-tests.js
    env:
      mocha: true

This configuration will fix error message about describe and it not defined, only for your test folder:

/myproject/test/init-tests.js
6:1 error 'describe' is not defined no-undef
9:3 error 'it' is not defined no-undef

IntelliJ: Working on multiple projects

Yes, your intuition was good. You shouldn't use three instances of intellij. You can open one Project and add other 'parts' of application as Modules. Add them via project browser, default hotkey is alt+1

How to determine whether a given Linux is 32 bit or 64 bit?

If you have a 64-bit OS, instead of i686, you have x86_64 or ia64 in the output of uname -a. In that you do not have any of these two strings; you have a 32-bit OS (note that this does not mean that your CPU is not 64-bit).

Table is marked as crashed and should be repaired

I had the same issue when my server free disk space available was 0

You can use the command (there must be ample space for the mysql files)

REPAIR TABLE `<table name>`;

for repairing individual tables

Maven plugin not using Eclipse's proxy settings

<?xml version="1.0" encoding="UTF-8"?>
<settings xmlns="http://maven.apache.org/SETTINGS/1.1.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.1.0 http://maven.apache.org/xsd/settings-1.1.0.xsd">

     <proxies>
       <proxy>
          <active>true</active>
          <protocol>http</protocol>
          <host>proxy.somewhere.com</host>
          <port>8080</port>
          <username>proxyuser</username>
          <password>somepassword</password>
          <nonProxyHosts>www.google.com|*.somewhere.com</nonProxyHosts>
        </proxy>
      </proxies>

    </settings>

Window > Preferences > Maven > User Settings

enter image description here

Linux Shell Script For Each File in a Directory Grab the filename and execute a program

for i in *.xls ; do 
  [[ -f "$i" ]] || continue
  xls2csv "$i" "${i%.xls}.csv"
done

The first line in the do checks if the "matching" file really exists, because in case nothing matches in your for, the do will be executed with "*.xls" as $i. This could be horrible for your xls2csv.

How to write a bash script that takes optional input arguments?

MySQL select all rows from last month until (now() - 1 month), for comparative purposes

SELECT *
FROM table
WHERE myDtate BETWEEN now()
    , DATE_SUB(NOW()
    , INTERVAL 1 MONTH)

Unable to start MySQL server

In my case I had to go to the MySQL installer, then configuration button for the MySQL server, then next until the option to "create the server as a windows service" ticked that, gave it a service name as MySQL8.0, next and then finish, that solved the issue and started a new service

Got a NumberFormatException while trying to parse a text file for objects

The problem might be your split() call. Try just split(" ") without the square brackets.

How to give credentials in a batch script that copies files to a network location?

You can also map the share to a local drive as follows:

net use X: "\\servername\share" /user:morgan password

How to use the COLLATE in a JOIN in SQL Server?

Correct syntax looks like this. See MSDN.

SELECT *
  FROM [FAEB].[dbo].[ExportaComisiones] AS f
  JOIN [zCredifiel].[dbo].[optPerson] AS p

  ON p.vTreasuryId COLLATE Latin1_General_CI_AS = f.RFC COLLATE Latin1_General_CI_AS

Check if current date is between two dates Oracle SQL

TSQL: Dates- need to look for gaps in dates between Two Date

select
distinct
e1.enddate,
e3.startdate,
DATEDIFF(DAY,e1.enddate,e3.startdate)-1 as [Datediff]
from #temp e1 
   join #temp e3 on e1.enddate < e3.startdate          
       /* Finds the next start Time */
and e3.startdate = (select min(startdate) from #temp e5
where e5.startdate > e1.enddate)
and not exists (select *  /* Eliminates e1 rows if it is overlapped */
from #temp e5 
where e5.startdate < e1.enddate and e5.enddate > e1.enddate);

change <audio> src with javascript

change this

audio.src='audio/ogg/' + document.getElementById(song1.ogg);

audio.src='audio/ogg/' + document.getElementById('song1');

How to form a correct MySQL connection string?

Here is an example:

MySqlConnection con = new MySqlConnection(
    "Server=ServerName;Database=DataBaseName;UID=username;Password=password");

MySqlCommand cmd = new MySqlCommand(
    " INSERT Into Test (lat, long) VALUES ('"+OSGconv.deciLat+"','"+
    OSGconv.deciLon+"')", con);

con.Open();
cmd.ExecuteNonQuery();
con.Close();

Service Reference Error: Failed to generate code for the service reference

I have encountered this problem when upgrading a VS2010 WCF+Silverlight solution in VS2015 Professional. Besides automatically upgrading from Silverlight 4 to Silverlight 5, the service reference reuse checkbox value was changed and generation failed.

Using group by and having clause

First of all, you should use the JOIN syntax rather than FROM table1, table2, and you should always limit the grouping to as little fields as you need.

Altought I haven't tested, your first query seems fine to me, but could be re-written as:

SELECT s.sid, s.name
FROM 
    Supplier s
    INNER JOIN (
       SELECT su.sid
       FROM Supplies su
       GROUP BY su.sid
       HAVING COUNT(DISTINCT su.jid) > 1
    ) g
        ON g.sid = s.sid

Or simplified as:

SELECT sid, name
FROM Supplier s
WHERE (
    SELECT COUNT(DISTINCT su.jid)
    FROM Supplies su
    WHERE su.sid = s.sid
) > 1

However, your second query seems wrong to me, because you should also GROUP BY pid.

 SELECT s.sid, s.name
    FROM 
        Supplier s
        INNER JOIN (
            SELECT su.sid
            FROM Supplies su
            GROUP BY su.sid, su.pid
            HAVING COUNT(DISTINCT su.jid) > 1
        ) g
            ON g.sid = s.sid

As you may have noticed in the query above, I used the INNER JOIN syntax to perform the filtering, however it can be also written as:

SELECT s.sid, s.name
FROM Supplier s
WHERE (
     SELECT COUNT(DISTINCT su.jid)
     FROM Supplies su
     WHERE su.sid = s.sid
     GROUP BY su.sid, su.pid
) > 1

How to while loop until the end of a file in Python without checking for empty line?

Find end position of file:

f = open("file.txt","r")
f.seek(0,2) #Jumps to the end
f.tell()    #Give you the end location (characters from start)
f.seek(0)   #Jump to the beginning of the file again

Then you can to:

if line == '' and f.tell() == endLocation:
   break

How does the @property decorator work in Python?

Let's start with Python decorators.

A Python decorator is a function that helps to add some additional functionalities to an already defined function.

In Python, everything is an object. Functions in Python are first-class objects which means that they can be referenced by a variable, added in the lists, passed as arguments to another function etc.

Consider the following code snippet.

def decorator_func(fun):
    def wrapper_func():
        print("Wrapper function started")
        fun()
        print("Given function decorated")
        # Wrapper function add something to the passed function and decorator 
        # returns the wrapper function
    return wrapper_func

def say_bye():
    print("bye!!")

say_bye = decorator_func(say_bye)
say_bye()

# Output:
#  Wrapper function started
#  bye
#  Given function decorated

Here, we can say that decorator function modified our say_hello function and added some extra lines of code in it.

Python syntax for decorator

def decorator_func(fun):
    def wrapper_func():
        print("Wrapper function started")
        fun()
        print("Given function decorated")
        # Wrapper function add something to the passed function and decorator 
        # returns the wrapper function
    return wrapper_func

@decorator_func
def say_bye():
    print("bye!!")

say_bye()

Let's Concluded everything than with a case scenario, but before that let's talk about some oops priniciples.

Getters and setters are used in many object oriented programming languages to ensure the principle of data encapsulation(is seen as the bundling of data with the methods that operate on these data.)

These methods are of course the getter for retrieving the data and the setter for changing the data.

According to this principle, the attributes of a class are made private to hide and protect them from other code.

Yup, @property is basically a pythonic way to use getters and setters.

Python has a great concept called property which makes the life of an object-oriented programmer much simpler.

Let us assume that you decide to make a class that could store the temperature in degree Celsius.

class Celsius:
def __init__(self, temperature = 0):
    self.set_temperature(temperature)

def to_fahrenheit(self):
    return (self.get_temperature() * 1.8) + 32

def get_temperature(self):
    return self._temperature

def set_temperature(self, value):
    if value < -273:
        raise ValueError("Temperature below -273 is not possible")
    self._temperature = value

Refactored Code, Here is how we could have achieved it with property.

In Python, property() is a built-in function that creates and returns a property object.

A property object has three methods, getter(), setter(), and delete().

class Celsius:
def __init__(self, temperature = 0):
    self.temperature = temperature

def to_fahrenheit(self):
    return (self.temperature * 1.8) + 32

def get_temperature(self):
    print("Getting value")
    return self.temperature

def set_temperature(self, value):
    if value < -273:
        raise ValueError("Temperature below -273 is not possible")
    print("Setting value")
    self.temperature = value

temperature = property(get_temperature,set_temperature)

Here,

temperature = property(get_temperature,set_temperature)

could have been broken down as,

# make empty property
temperature = property()
# assign fget
temperature = temperature.getter(get_temperature)
# assign fset
temperature = temperature.setter(set_temperature)

Point To Note:

get_temperature remains a property instead of a method.

Now you can access the value of temperature by writing.

C = Celsius()
C.temperature
# instead of writing C.get_temperature()

We can further go on and not define names get_temperature and set_temperature as they are unnecessary and pollute the class namespace.

The pythonic way to deal with the above problem is to use @property.

class Celsius:
    def __init__(self, temperature = 0):
        self.temperature = temperature

    def to_fahrenheit(self):
        return (self.temperature * 1.8) + 32

    @property
    def temperature(self):
        print("Getting value")
        return self.temperature

    @temperature.setter
    def temperature(self, value):
        if value < -273:
            raise ValueError("Temperature below -273 is not possible")
        print("Setting value")
        self.temperature = value

Points to Note -

A method which is used for getting a value is decorated with "@property".
The method which has to function as the setter is decorated with "@temperature.setter", If the function had been called "x", we would have to decorate it with "@x.setter".
We wrote "two" methods with the same name and a different number of parameters "def temperature(self)" and "def temperature(self,x)".

As you can see, the code is definitely less elegant.

Now,let's talk about one real-life practical scenerio.

Let's say you have designed a class as follows:

class OurClass:

    def __init__(self, a):
        self.x = a


y = OurClass(10)
print(y.x)

Now, let's further assume that our class got popular among clients and they started using it in their programs, They did all kinds of assignments to the object.

And One fateful day, a trusted client came to us and suggested that "x" has to be a value between 0 and 1000, this is really a horrible scenario!

Due to properties it's easy: We create a property version of "x".

class OurClass:

    def __init__(self,x):
        self.x = x

    @property
    def x(self):
        return self.__x

    @x.setter
    def x(self, x):
        if x < 0:
            self.__x = 0
        elif x > 1000:
            self.__x = 1000
        else:
            self.__x = x

This is great, isn't it: You can start with the simplest implementation imaginable, and you are free to later migrate to a property version without having to change the interface! So properties are not just a replacement for getters and setter!

You can check this Implementation here

How to Scroll Down - JQuery

Try This:

window.scrollBy(0,180); // horizontal and vertical scroll increments

Is there a way to represent a directory tree in a Github README.md?

If you are working on windows write tree /f inside the directory you want to achieve that in command prompt. This should do your job. you can copy and paste the output on markdown surrounded my triple back ticks i.e. '''{tree structure here}'''

How to open existing project in Eclipse

Window->Show View->Navigator, should pop up the navigator panel on the left hand side, showing the projects list.

It's probably already open in the workspace, but you may have closed the navigator panel, so it looks like you don't have the project open.

Eclipse using ADT Build v22.0.0-675183 on Linux.

Are there any SHA-256 javascript implementations that are generally considered trustworthy?

On https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/digest I found this snippet that uses internal js module:

async function sha256(message) {
    // encode as UTF-8
    const msgBuffer = new TextEncoder().encode(message);                    

    // hash the message
    const hashBuffer = await crypto.subtle.digest('SHA-256', msgBuffer);

    // convert ArrayBuffer to Array
    const hashArray = Array.from(new Uint8Array(hashBuffer));

    // convert bytes to hex string                  
    const hashHex = hashArray.map(b => ('00' + b.toString(16)).slice(-2)).join('');
    return hashHex;
}

Note that crypto.subtle in only available on https or localhost - for example for your local development with python3 -m http.server you need to add this line to your /etc/hosts: 0.0.0.0 localhost

Reboot - and you can open localhost:8000 with working crypto.subtle.

How do I write to the console from a Laravel Controller?

You can use echo and prefix "\033", simple:

Artisan::command('mycommand', function () {
   echo "\033======== Start ========\n";
});

And change color text:

if (App::environment() === 'production') {
    echo "\033[0;33m======== WARNING ========\033[0m\n";
}

How to run function of parent window when child window closes?

Check following link. This would be helpful too..

In Parent Window:

function OpenChildAsPopup() {
        var childWindow = window.open("ChildWindow.aspx", "_blank",
        "width=200px,height=350px,left=200,top=100");
        childWindow.focus();
 }

function ChangeBackgroudColor() {
        var para = document.getElementById('samplePara');
        if (para !="undefied") {
            para.style.backgroundColor = '#6CDBF5';
        }
 }

Parent Window HTML Markup:

<div>
  <p id="samplePara" style="width: 350px;">
            Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
  </p><br />
 <asp:Button ID="Button1" Text="Open Child Window" 
         runat="server" OnClientClick="OpenChildAsPopup();"/>
</div>

In Child Window:

// This will be called when the child window is closed.     
  window.onunload = function (e) {
        opener.ChangeBackgroudColor();
        //or you can do
        //var para = opener.document.getElementById('samplePara');
        //if (para != "undefied") {
        //    para.style.backgroundColor = '#6CDBF5';
        //}
    };

How to force a component's re-rendering in Angular 2?

ChangeDetectorRef approach

import { Component, OnInit, ChangeDetectorRef } from '@angular/core';

export class MyComponent {

    constructor(private cdr: ChangeDetectorRef) { }

    selected(item: any) {
        if (item == 'Department')
            this.isDepartment = true;
        else
            this.isDepartment = false;
        this.cdr.detectChanges();
    }

}

How can I compare two dates in PHP?

Just to compliment the already given answers, see the following example:

$today = new DateTime('');
$expireDate = new DateTime($row->expireDate); //from database



if($today->format("Y-m-d") < $expireDate->format("Y-m-d")) { 
    //do something; 
}

Update: Or simple use old-school date() function:

if(date('Y-m-d') < date('Y-m-d', strtotime($expire_date))){
    //echo not yet expired! 
}

Re-order columns of table in Oracle

It's sad that Oracle doesn't allow this, I get asked to do this by developers all the time..

Here's a slightly dangerous, somewhat quick and dirty method:

Ensure you have enough space to copy the Table
Note any Constraints, Grants, Indexes, Synonyms, Triggers, um.. maybe some other stuff - that belongs to a Table - that I haven't thought about?
CREATE TABLE table_right_columns AS SELECT column1 column3, column2 FROM table_wrong_columns; -- Notice how we correct the position of the columns :)
DROP TABLE table_wrong_columns;
'ALTER TABLE table_right_columns RENAME TO table_wrong_columns;`
Now the yucky part: recreate all those items you noted in step 2 above
Check what code is now invalid, and recompile to check for errors

And next time you create a table, please consider the future requirements! ;)

Difference between InvariantCulture and Ordinal string comparison

InvariantCulture

Uses a "standard" set of character orderings (a,b,c, ... etc.). This is in contrast to some specific locales, which may sort characters in different orders ('a-with-acute' may be before or after 'a', depending on the locale, and so on).

Ordinal

On the other hand, looks purely at the values of the raw byte(s) that represent the character.

There's a great sample at http://msdn.microsoft.com/en-us/library/e6883c06.aspx that shows the results of the various StringComparison values. All the way at the end, it shows (excerpted):

StringComparison.InvariantCulture:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.Ordinal:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is greater than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

You can see that where InvariantCulture yields (U+0069, U+0049, U+00131), Ordinal yields (U+0049, U+0069, U+00131).

Programs & Examples On #Bbedit