Programs & Examples On #Cassini

The Cassini Web Server is an open-source lightweight web server distributed with ASP.NET as an example of an ASP.NET web server written in C#.

Visual Studio debugging/loading very slow

The problem for me was the "Browser Link" feature that is very heavy when you have several tabs open for the same project !

Because every time we launched the project, it opens a new tab with browser link communications.

Just close all tabs associated with the project and keep only one open !

This free instantaneously visual studio ! It’s magic ! ;-)

“Browser Link is a feature since Visual Studio 2013 that creates a communication channel between the development environment and one or more web browsers. You can use Browser Link to refresh your web application in several browsers at once, which is useful for cross-browser testing.”

How can I open an Excel file in Python?

This code worked for me with Python 3.5.2. It opens and saves and excel. I am currently working on how to save data into the file but this is the code:

import csv
excel = csv.writer(open("file1.csv", "wb"))

 

Getting Date or Time only from a DateTime Object

You can also use DateTime.Now.ToString("yyyy-MM-dd") for the date, and DateTime.Now.ToString("hh:mm:ss") for the time.

Change Color of Fonts in DIV (CSS)

To do links, you can do

.social h2 a:link {
  color: pink;
  font-size: 14px;   
}

You can change the hover, visited, and active link styling too. Just replace "link" with what you want to style. You can learn more at the w3schools page CSS Links.

how to delete all commit history in github?

If you are sure you want to remove all commit history, simply delete the .git directory in your project root (note that it's hidden). Then initialize a new repository in the same folder and link it to the GitHub repository:

git init
git remote add origin [email protected]:user/repo

now commit your current version of code

git add *
git commit -am 'message'

and finally force the update to GitHub:

git push -f origin master

However, I suggest backing up the history (the .git folder in the repository) before taking these steps!

Choose Git merge strategy for specific files ("ours", "mine", "theirs")

Note that git checkout --ours|--theirs will overwrite the files entirely, by choosing either theirs or ours version, which might be or might not be what you want to do (if you have any non-conflicted changes coming from the other side, they will be lost).

If instead you want to perform a three-way merge on the file, and only resolve the conflicted hunks using --ours|--theirs, while keeping non-conflicted hunks from both sides in place, you may want to resort to git merge-file; see details in this answer.

How to throw std::exceptions with variable messages?

A really nicer way would be creating a class (or classes) for the exceptions.

Something like:

class ConfigurationError : public std::exception {
public:
    ConfigurationError();
};

class ConfigurationLoadError : public ConfigurationError {
public:
    ConfigurationLoadError(std::string & filename);
};

The reason is that exceptions are much more preferable than just transferring a string. Providing different classes for the errors, you give developers a chance to handle a particular error in a corresponded way (not just display an error message). People catching your exception can be as specific as they need if you use a hierarchy.

a) One may need to know the specific reason

} catch (const ConfigurationLoadError & ex) {
// ...
} catch (const ConfigurationError & ex) {

a) another does not want to know details

} catch (const std::exception & ex) {

You can find some inspiration on this topic in https://books.google.ru/books?id=6tjfmnKhT24C Chapter 9

Also, you can provide a custom message too, but be careful - it is not safe to compose a message with either std::string or std::stringstream or any other way which can cause an exception.

Generally, there is no difference whether you allocate memory (work with strings in C++ manner) in the constructor of the exception or just before throwing - std::bad_alloc exception can be thrown before the one which you really want.

So, a buffer allocated on the stack (like in Maxim's answer) is a safer way.

It is explained very well at http://www.boost.org/community/error_handling.html

So, the nicer way would be a specific type of the exception and be avoiding composing the formatted string (at least when throwing).

Visual Studio Code: format is not using indent settings

For myself, this problem was caused by using the prettier VSCode plugin without having a prettier config file in the workspace.

Disabling the plugin fixed the problem. It could have also probably been fixed by relying on the prettier config.

Plotting multiple lines, in different colors, with pandas dataframe

You could use groupby to split the DataFrame into subgroups according to the color:

for key, grp in df.groupby(['color']):

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

df = pd.read_table('data', sep='\s+')
fig, ax = plt.subplots()

for key, grp in df.groupby(['color']):
    ax = grp.plot(ax=ax, kind='line', x='x', y='y', c=key, label=key)

plt.legend(loc='best')
plt.show()

yields enter image description here

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

Taking up @ZF007's answer, this is not answering your question as a whole, but can be the solution for the same error. I post it here since I have not found a direct solution as an answer to this error message elsewhere on Stack Overflow.

The error appears when you check whether an array was empty or not.

  • if np.array([1,2]): print(1) --> ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all().

  • if np.array([1,2])[0]: print(1) --> no ValueError, but: if np.array([])[0]: print(1) --> IndexError: index 0 is out of bounds for axis 0 with size 0.

  • if np.array([1]): print(1) --> no ValueError, but again will not help at an array with many elements.

  • if np.array([]): print(1) --> DeprecationWarning: The truth value of an empty array is ambiguous. Returning False, but in future this will result in an error. Use 'array.size > 0' to check that an array is not empty.

Doing so:

  • if np.array([]).size: print(1) solved the error.

What are the sizes used for the iOS application splash screen?

With iOS 7+, static Launch Images are now deprecated.

You should create a custom view that composes slices of images, which sizes to all screens like a normal UIViewController view.

https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/MobileHIG/LaunchImages.html

Error:Conflict with dependency 'com.google.code.findbugs:jsr305'

METHOD 1: I deleted the androidTestCompile on espresso-core line which was automatically included in a new project. Then my Android Studio compiles clean.

The androidTestCompile is in "build.gradle (Module:app)":

dependencies {
    ...
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    ...
}

I don't know whether this deletion will have any problem down the road, but it surely works for my current project now.

METHOD 2: Adding an exclude on findbugs works too:

dependencies {
    ...
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
        exclude group: 'com.google.code.findbugs'
    })
    ...
}

METHOD 3: Forcing compiling with a specific version:

(In the following I force it to compile with the higher version.)

dependencies {
    ...
    androidTestCompile 'com.google.code.findbugs:jsr305:3.0.0'
    ...
}

Mongoose, update values in array of objects

There is one thing to remember, when you are searching the object in array on the basis of more than one condition then use $elemMatch

Person.update(
   {
     _id: 5,
     grades: { $elemMatch: { grade: { $lte: 90 }, mean: { $gt: 80 } } }
   },
   { $set: { "grades.$.std" : 6 } }
)

here is the docs

jQuery.click() vs onClick

<whatever onclick="doStuff();" onmouseover="in()" onmouseout="out()" />

onclick, onmouseover, onmouseout, etc. events are actually bad for performance (in Internet Explorer mainly, go figure). If you code using Visual Studio, when you run a page with these, every single one of these will create a separate SCRIPT block taking up memory, and thus slowing down performance.

Not to mention you should have a separation of concerns: JavaScript and layouts should be separated!

It is always better to create evenHandlers for any of these events, one event can capture hundreds/thousands of items, instead of creating thousands of separate script blocks for each one!

(Also, everything everyone else is saying.)

Bootstrap datetimepicker is not a function

Below is the right code. Include JS files in following manner:

_x000D_
_x000D_
$(document).ready(function() {_x000D_
  $(function() {_x000D_
    $('#datetimepicker6').datetimepicker();_x000D_
    $('#datetimepicker7').datetimepicker({_x000D_
      useCurrent: false //Important! See issue #1075_x000D_
    });_x000D_
    $("#datetimepicker6").on("dp.change", function(e) {_x000D_
      $('#datetimepicker7').data("DateTimePicker").minDate(e.date);_x000D_
    });_x000D_
    $("#datetimepicker7").on("dp.change", function(e) {_x000D_
      $('#datetimepicker6').data("DateTimePicker").maxDate(e.date);_x000D_
    });_x000D_
  });_x000D_
});
_x000D_
<html>_x000D_
_x000D_
<!-- Latest compiled and minified CSS -->_x000D_
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">_x000D_
_x000D_
<!-- Optional theme -->_x000D_
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap-theme.min.css">_x000D_
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-datetimepicker/4.17.37/css/bootstrap-datetimepicker.min.css" />_x000D_
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.10.6/moment.min.js"></script>_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>_x000D_
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>_x000D_
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-datetimepicker/4.17.37/js/bootstrap-datetimepicker.min.js"></script>_x000D_
_x000D_
<body>_x000D_
_x000D_
_x000D_
_x000D_
  <div class="container">_x000D_
    <div class='col-md-5'>_x000D_
      <div class="form-group">_x000D_
        <div class='input-group date' id='datetimepicker6'>_x000D_
          <input type='text' class="form-control" />_x000D_
          <span class="input-group-addon">_x000D_
                        <span class="glyphicon glyphicon-calendar"></span>_x000D_
          </span>_x000D_
        </div>_x000D_
      </div>_x000D_
    </div>_x000D_
    <div class='col-md-5'>_x000D_
      <div class="form-group">_x000D_
        <div class='input-group date' id='datetimepicker7'>_x000D_
          <input type='text' class="form-control" />_x000D_
          <span class="input-group-addon">_x000D_
                        <span class="glyphicon glyphicon-calendar"></span>_x000D_
          </span>_x000D_
        </div>_x000D_
      </div>_x000D_
    </div>_x000D_
  </div>_x000D_
_x000D_
_x000D_
_x000D_
</body>_x000D_
_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_

Deploying just HTML, CSS webpage to Tomcat

Here's my step in Ubuntu 16.04 and Tomcat 8.

  1. Copy folder /var/lib/tomcat8/webapps/ROOT to your folder.

    cp -r /var/lib/tomcat8/webapps/ROOT /var/lib/tomcat8/webapps/{yourfolder}

  2. Add your html, css, js, to your folder.

  3. Open "http://localhost:8080/{yourfolder}" in browser

Notes:

  1. If you using chrome web browser and did wrong folder before, then clean web browser's cache(or change another name) otherwise (sometimes) it always 404.

  2. The folder META-INF with context.xml is needed.

Pandas How to filter a Series

If you like a chained operation, you can also use compress function:

test = pd.Series({
383:    3.000000,
663:    1.000000,
726:    1.000000,
737:    9.000000,
833:    8.166667
})

test.compress(lambda x: x != 1)

# 383    3.000000
# 737    9.000000
# 833    8.166667
# dtype: float64

How to change workspace and build record Root Directory on Jenkins?

By default, Jenkins stores all of its data in this directory on the file system.

There are a few ways to change the Jenkins home directory:

  • Edit the JENKINS_HOME variable in your Jenkins configuration file (e.g. /etc/sysconfig/jenkins on Red Hat Linux).
  • Use your web container's admin tool to set the JENKINS_HOME environment variable.
  • Set the environment variable JENKINS_HOME before launching your web container, or before launching Jenkins directly from the WAR file.
  • Set the JENKINS_HOME Java system property when launching your web container, or when launching Jenkins directly from the WAR file.
  • Modify web.xml in jenkins.war (or its expanded image in your web container). This is not recommended. This value cannot be changed while Jenkins is running. It is shown here to help you ensure that your configuration is taking effect.

SQL Sum Multiple rows into one

Thank you for your responses. Turns out my problem was a database issue with duplicate entries, not with my logic. A quick table sync fixed that and the SUM feature worked as expected. This is all still useful knowledge for the SUM feature and is worth reading if you are having trouble using it.

H.264 file size for 1 hr of HD video

I'm a friend of keeping the original files, so that you can still use the archived original ones and do new encodes from these fresh ones when the old transcodes are out of date. eg. migrating them from previously transocded mpeg2-hd to mpeg4-hd (and perhaps from mpeg4-hd to its successor in sometime). but all of these should be done from the original. any compression step will followed by a loss of quality. it will need some time to redo this again, but in my opinion it's worth the effort.

so, if you want to keep the originals, you can use the running time in seconds of you tapes times the maximum datarate of hdv (constants 27mbit/s I think) to get your needed storage capacity

Python not working in the command line of git bash

I am using MINGW64 via Visual Studio Code on Windows 10 and trying to install node-sass (which requires python2). I followed felixrieseberg/windows-build-tools #56 on Github which solved my issue.

This is a special case, but I'm posting in case someone has the same problem:

npm --add-python-to-path='true' --debug install --global windows-build-tools

This installs python and other required build tools to %USERPROFILE%\.windows-build-tools\python27.

How to read and write INI file with Python3?

contents in my backup_settings.ini file

[Settings]
year = 2020

python code for reading

import configparser
config = configparser.ConfigParser()
config.read('backup_settings.ini') #path of your .ini file
year = config.get("Settings","year") 
print(year)

for writing or updating

from pathlib import Path
import configparser
myfile = Path('backup_settings.ini')  #Path of your .ini file
config.read(myfile)
config.set('Settings', 'year','2050') #Updating existing entry 
config.set('Settings', 'day','sunday') #Writing new entry
config.write(myfile.open("w"))

output

[Settings]
year = 2050
day = sunday

How to do this in Laravel, subquery where in

The script is tested in Laravel 5.x and 6.x. The static closure can improve performance in some cases.

Product::select(['id', 'name', 'img', 'safe_name', 'sku', 'productstatusid'])
            ->whereIn('id', static function ($query) {
                $query->select(['product_id'])
                    ->from((new ProductCategory)->getTable())
                    ->whereIn('category_id', [15, 223]);
            })
            ->where('active', 1)
            ->get();

generates the SQL

SELECT `id`, `name`, `img`, `safe_name`, `sku`, `productstatusid` FROM `products` 
WHERE `id` IN (SELECT `product_id` FROM `product_category` WHERE 
`category_id` IN (?, ?)) AND `active` = ?

Confirmation before closing of tab/browser

If you want to ask based on condition:

var ask = true
window.onbeforeunload = function (e) {
    if(!ask) return null
    e = e || window.event;
    //old browsers
    if (e) {e.returnValue = 'Sure?';}
    //safari, chrome(chrome ignores text)
    return 'Sure?';
};

how to make a full screen div, and prevent size to be changed by content?

Notice how most of these can only be used WITHOUT a DOCTYPE. I'm looking for the same answer, but I have a DOCTYPE. There is one way to do it with a DOCTYPE however, although it doesn't apply to the style of my site, but it will work on the type of page you want to create:

div#full-size{
    position: absolute;
    top:0;
    bottom:0;
    right:0;
    left:0;
    overflow:hidden;

Now, this was mentioned earlier but I just wanted to clarify that this is normally used with a DOCTYPE, height:100%; only works without a DOCTYPE

Writing/outputting HTML strings unescaped

Supposing your content is inside a string named mystring...

You can use:

@Html.Raw(mystring)

Alternatively you can convert your string to HtmlString or any other type that implements IHtmlString in model or directly inline and use regular @:

@{ var myHtmlString = new HtmlString(mystring);}
@myHtmlString

jQuery select change event get selected option

Another and short way to get value of selected value,

$('#selectElement').on('change',function(){
   var selectedVal = $(this).val();
                       ^^^^  ^^^^ -> presents #selectElement selected value 
                         |
                         v
               presents #selectElement, 
});

Java Mouse Event Right Click

I've seen

anEvent.isPopupTrigger() 

be used before. I'm fairly new to Java so I'm happy to hear thoughts about this approach :)

How do I run a Python program?

Navigate your file location just press Shift button and click file name. Click tab Open command window here and write in your command prompt python file_name.py

Read specific columns with pandas or other python module

According to the latest pandas documentation you can read a csv file selecting only the columns which you want to read.

import pandas as pd

df = pd.read_csv('some_data.csv', usecols = ['col1','col2'], low_memory = True)

Here we use usecols which reads only selected columns in a dataframe.

We are using low_memory so that we Internally process the file in chunks.

How to remove files and directories quickly via terminal (bash shell)

rm -rf some_dir

-r "recursive" -f "force" (suppress confirmation messages)

Be careful!

How to save a Python interactive session?

In IPython, I first use

In [2]: %hist

to view my past code. I select the chunk I want to save and then paste it into file my_file.py using the %%file magic (short for %%writefile)

In [3]: %%file my_file.py
   ...: # paste code here 
   ...:  
   ...:  

hitting return two times in the end.

To append to file use the option -a: %%file -a my_file.py.

If needed, I can list, edit, etc. the file in the underlying command line using the exclamation mark

In [5]: !ls -l my_file.py
In [6]: !vi my_file.py

Watch multiple $scope attributes

$watch first parameter can also be a function.

$scope.$watch(function watchBothItems() {
  return itemsCombinedValue();
}, function whenItemsChange() {
  //stuff
});

If your two combined values are simple, the first parameter is just an angular expression normally. For example, firstName and lastName:

$scope.$watch('firstName + lastName', function() {
  //stuff
});

How to create a DataFrame from a text file in Spark

val df = spark.read.textFile("abc.txt")

case class Abc (amount:Int, types: String, id:Int)  //columns and data types

val df2 = df.map(rec=>Amount(rec(0).toInt, rec(1), rec(2).toInt))
rdd2.printSchema

root
 |-- amount: integer (nullable = true)
 |-- types: string (nullable = true)
 |-- id: integer (nullable = true)

Postgres: SQL to list table foreign keys

Note: Do not forget column's order while reading constraint columns!

SELECT conname, attname
  FROM pg_catalog.pg_constraint c 
  JOIN pg_catalog.pg_attribute a ON a.attrelid = c.conrelid AND a.attnum = ANY (c.conkey)
 WHERE attrelid = 'schema.table_name'::regclass
 ORDER BY conname, array_position(c.conkey, a.attnum)

javascript - pass selected value from popup window to parent window input box

If you want a popup window rather than a <div />, I would suggest the following approach.

In your parent page, you call a small helper method to show the popup window:

<input type="button" name="choice" onClick="selectValue('sku1')" value="?">

Add the following JS methods:

function selectValue(id)
{
    // open popup window and pass field id
    window.open('sku.php?id=' + encodeURIComponent(id),'popuppage',
      'width=400,toolbar=1,resizable=1,scrollbars=yes,height=400,top=100,left=100');
}

function updateValue(id, value)
{
    // this gets called from the popup window and updates the field with a new value
    document.getElementById(id).value = value;
}

Your sku.php receives the selected field via $_GET['id'] and uses it to construct the parent callback function:

?>
<script type="text/javascript">
function sendValue(value)
{
    var parentId = <?php echo json_encode($_GET['id']); ?>;
    window.opener.updateValue(parentId, value);
    window.close();
}
</script>

For each row in your popup, change code to this:

<td><input type=button value="Select" onClick="sendValue('<?php echo $rows['packcode']; ?>')" /></td>

Following this approach, the popup window doesn't need to know how to update fields in the parent form.

How to uninstall a windows service and delete its files without rebooting

As noted by StingyJack and mcbala, and in reference to comments made by Mike L, my experience is that on a Windows 2000 machine, when uninstalling / reinstalling .Net services, "installutil /u" does require a reboot, even when the service was previously stopped. "sc /delete", on the other hand, does not require a reboot - it deletes the service right away (as long as it is stopped).

I have often wondered, actually, whether there is a good reason "installutil /u" requires a reboot... Is "sc /delete" actually doing something wrong / leaving something hanging?

How to manually set an authenticated user in Spring Security / SpringMVC

I had the same problem as you a while back. I can't remember the details but the following code got things working for me. This code is used within a Spring Webflow flow, hence the RequestContext and ExternalContext classes. But the part that is most relevant to you is the doAutoLogin method.

public String registerUser(UserRegistrationFormBean userRegistrationFormBean,
                           RequestContext requestContext,
                           ExternalContext externalContext) {

    try {
        Locale userLocale = requestContext.getExternalContext().getLocale();
        this.userService.createNewUser(userRegistrationFormBean, userLocale, Constants.SYSTEM_USER_ID);
        String emailAddress = userRegistrationFormBean.getChooseEmailAddressFormBean().getEmailAddress();
        String password = userRegistrationFormBean.getChoosePasswordFormBean().getPassword();
        doAutoLogin(emailAddress, password, (HttpServletRequest) externalContext.getNativeRequest());
        return "success";

    } catch (EmailAddressNotUniqueException e) {
        MessageResolver messageResolvable 
                = new MessageBuilder().error()
                                      .source(UserRegistrationFormBean.PROPERTYNAME_EMAIL_ADDRESS)
                                      .code("userRegistration.emailAddress.not.unique")
                                      .build();
        requestContext.getMessageContext().addMessage(messageResolvable);
        return "error";
    }

}


private void doAutoLogin(String username, String password, HttpServletRequest request) {

    try {
        // Must be called from request filtered by Spring Security, otherwise SecurityContextHolder is not updated
        UsernamePasswordAuthenticationToken token = new UsernamePasswordAuthenticationToken(username, password);
        token.setDetails(new WebAuthenticationDetails(request));
        Authentication authentication = this.authenticationProvider.authenticate(token);
        logger.debug("Logging in with [{}]", authentication.getPrincipal());
        SecurityContextHolder.getContext().setAuthentication(authentication);
    } catch (Exception e) {
        SecurityContextHolder.getContext().setAuthentication(null);
        logger.error("Failure in autoLogin", e);
    }

}

Adb install failure: INSTALL_CANCELED_BY_USER

I had the same problem before. Here was my solution:

  1. Go to Setting ? find Developer options in System, and click.
  2. TURN ON install via USB in the Debuging section.
  3. Try Run app in Android Studio again!

How to display errors on laravel 4?

Following the good advice by @The Shift Exchange I looked at the error_log and indeed managed to solve to problem. it was simply a permissions issue:

Tue Feb 26 11:22:20 2013] [error] [client 127.0.0.1] PHP Fatal error:  Uncaught exception 'UnexpectedValueException' with message 'The stream or file "/Users/matanya/Sites/indgo/app/start/../storage/logs/log-apache2handler-2013-02-26.txt" could not be opened: failed to open stream: Permission denied' in /Users/matanya/Sites/indgo/vendor/monolog/monolog/src/Monolog/Handler/StreamHandler.php:71\nStack trace:\n#0 /Users/matanya/Sites/indgo/vendor/monolog/monolog/src/Monolog/Handler/RotatingFileHandler.php(77): Monolog\\Handler\\StreamHandler->write(Array)\n#1 /Users/matanya/Sites/indgo/vendor/monolog/monolog/src/Monolog/Handler/AbstractProcessingHandler.php(37): Monolog\\Handler\\RotatingFileHandler->write(Array)\n#2 /Users/matanya/Sites/indgo/vendor/monolog/monolog/src/Monolog/Logger.php(217): Monolog\\Handler\\AbstractProcessingHandler->handle(Array)\n#3 /Users/matanya/Sites/indgo/vendor/monolog/monolog/src/Monolog/Logger.php(281): Monolog\\Logger->addRecord(400, Object(ErrorException), Array)\n#4 [internal function]: Monolog\\Logger->addError(Object(ErrorException))\n#5 /Users/matanya/Sites/in in /Users/matanya/Sites/indgo/vendor/monolog/monolog/src/Monolog/Handler/StreamHandler.php on line 71

Once I used chmod to apply less stringent permissions, all went back to normal.

However, I'm not sure that it answers the OP's question, as he was getting a blank screen rather than a server error.

How to show empty data message in Datatables

Later versions of dataTables have the following language settings (taken from here):

  • "infoEmpty" - displayed when there are no records in the table
  • "zeroRecords" - displayed when there no records matching the filtering

e.g.

$('#example').DataTable( {
    "language": {
        "infoEmpty": "No records available - Got it?",
    }
});

Note: As the property names do not contain any special characters you can remove the quotes:

$('#example').DataTable( {
    language: {
        infoEmpty: "No records available - Got it?",
    }
});

curl Failed to connect to localhost port 80

In my case, the file ~/.curlrc had a wrong proxy configured.

init-param and context-param

<context-param> 
    <param-name>contextConfigLocation</param-name>
    <param-value>
        classpath*:/META-INF/PersistenceContext.xml
    </param-value>
</context-param>

I have initialized my PersistenceContext.xml within <context-param> because all my servlets will be interacting with database in MVC framework.

Howerver,

<servlet>
    <servlet-name>jersey-servlet</servlet-name>
    <servlet-class>com.sun.jersey.spi.spring.container.servlet.SpringServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            classpath:ApplicationContext.xml
        </param-value>
    </init-param>
    <init-param>
        <param-name>com.sun.jersey.config.property.packages</param-name>
        <param-value>com.organisation.project.rest</param-value>
    </init-param>
</servlet>

in the aforementioned code, I am configuring jersey and the ApplicationContext.xml only to rest layer. For the same I am using </init-param>

How to align entire html body to the center?

Try this

body {
max-width: max-content;
margin: auto;
}

Selecting multiple columns with linq query and lambda expression

        Object AccountObject = _dbContext.Accounts
                                   .Join(_dbContext.Users, acc => acc.AccountId, usr => usr.AccountId, (acc, usr) => new { acc, usr })
                                   .Where(x => x.usr.EmailAddress == key1)
                                   .Where(x => x.usr.Hash == key2)
                                   .Select(x => new { AccountId = x.acc.AccountId, Name = x.acc.Name })
                                   .SingleOrDefault();

Mocking a class: Mock() or patch()?

I've got a YouTube video on this.

Short answer: Use mock when you're passing in the thing that you want mocked, and patch if you're not. Of the two, mock is strongly preferred because it means you're writing code with proper dependency injection.

Silly example:

# Use a mock to test this.
my_custom_tweeter(twitter_api, sentence):
    sentence.replace('cks','x')   # We're cool and hip.
    twitter_api.send(sentence)

# Use a patch to mock out twitter_api. You have to patch the Twitter() module/class 
# and have it return a mock. Much uglier, but sometimes necessary.
my_badly_written_tweeter(sentence):
    twitter_api = Twitter(user="XXX", password="YYY")
    sentence.replace('cks','x') 
    twitter_api.send(sentence)

Java: how to convert HashMap<String, Object> to array

Map<String, String> map = new HashMap<String, String>();
map.put("key1", "value1");
map.put("key2", "value2");

Object[][] twoDarray = new Object[map.size()][2];

Object[] keys = map.keySet().toArray();
Object[] values = map.values().toArray();

for (int row = 0; row < twoDarray.length; row++) {
    twoDarray[row][0] = keys[row];
    twoDarray[row][1] = values[row];
}

// Print out the new 2D array
for (int i = 0; i < twoDarray.length; i++) {
    for (int j = 0; j < twoDarray[i].length; j++) {
        System.out.println(twoDarray[i][j]);
    }
}

How to use __DATE__ and __TIME__ predefined macros in as two integers, then stringify?

Short answer (asked version): (format 3.33.20150710.182906)

Please, simple use a makefile with:

MAJOR = 3
MINOR = 33
BUILD = $(shell date +"%Y%m%d.%H%M%S")
VERSION = "\"$(MAJOR).$(MINOR).$(BUILD)\""
CPPFLAGS = -DVERSION=$(VERSION)

program.x : source.c
       gcc $(CPPFLAGS) source.c -o program.x

and if you don't want a makefile, shorter yet, just compile with:

gcc source.c -o program.x -DVERSION=\"2.22.$(date +"%Y%m%d.%H%M%S")\"

Short answer (suggested version): (format 150710.182906)

Use a double for version number:

MakeFile:

VERSION = $(shell date +"%g%m%d.%H%M%S")
CPPFLAGS = -DVERSION=$(VERSION)
program.x : source.c
      gcc $(CPPFLAGS) source.c -o program.x

Or a simple bash command:

$ gcc source.c -o program.x -DVERSION=$(date +"%g%m%d.%H%M%S")

Tip: Still don't like makefile or is it just for a not-so-small test program? Add this line:

 export CPPFLAGS='-DVERSION='$(date +"%g%m%d.%H%M%S")

to your ~/.profile, and remember compile with gcc $CPPFLAGS ...


Long answer:

I know this question is older, but I have a small contribution to make. Best practice is always automatize what otherwise can became a source of error (or oblivion).

I was used to a function that created the version number for me. But I prefer this function to return a float. My version number can be printed by: printf("%13.6f\n", version()); which issues something like: 150710.150411 (being Year (2 digits) month day DOT hour minute seconds).

But, well, the question is yours. If you prefer "major.minor.date.time", it will have to be a string. (Trust me, double is better. If you insist in a major, you can still use double if you set the major and let the decimals to be date+time, like: major.datetime = 1.150710150411

Lets get to business. The example bellow will work if you compile as usual, forgetting to set it, or use -DVERSION to set the version directly from shell, but better of all, I recommend the third option: use a makefile.


Three forms of compiling and the results:

Using make:

beco> make program.x
gcc -Wall -Wextra -g -O0 -ansi -pedantic-errors -c -DVERSION="\"3.33.20150710.045829\"" program.c -o program.o
gcc  program.o -o program.x

Running:

__DATE__: 'Jul 10 2015'
__TIME__: '04:58:29'
VERSION: '3.33.20150710.045829'

Using -DVERSION:

beco> gcc program.c -o program.x -Wall -Wextra -g -O0 -ansi -pedantic-errors -DVERSION=\"2.22.$(date +"%Y%m%d.%H%M%S")\"

Running:

__DATE__: 'Jul 10 2015'
__TIME__: '04:58:37'
VERSION: '2.22.20150710.045837'

Using the build-in function:

beco> gcc program.c -o program.x -Wall -Wextra -g -O0 -ansi -pedantic-errors

Running:

__DATE__: 'Jul 10 2015'
__TIME__: '04:58:43'
VERSION(): '1.11.20150710.045843'

Source code

  1 #include <stdio.h>
  2 #include <stdlib.h>
  3 #include <string.h>
  4 
  5 #define FUNC_VERSION (0)
  6 #ifndef VERSION
  7   #define MAJOR 1
  8   #define MINOR 11
  9   #define VERSION version()
 10   #undef FUNC_VERSION
 11   #define FUNC_VERSION (1)
 12   char sversion[]="9999.9999.20150710.045535";
 13 #endif
 14 
 15 #if(FUNC_VERSION)
 16 char *version(void);
 17 #endif
 18 
 19 int main(void)
 20 {
 21 
 22   printf("__DATE__: '%s'\n", __DATE__);
 23   printf("__TIME__: '%s'\n", __TIME__);
 24 
 25   printf("VERSION%s: '%s'\n", (FUNC_VERSION?"()":""), VERSION);
 26   return 0;
 27 }
 28 
 29 /* String format: */
 30 /* __DATE__="Oct  8 2013" */
 31 /*  __TIME__="00:13:39" */
 32
 33 /* Version Function: returns the version string */
 34 #if(FUNC_VERSION)
 35 char *version(void)
 36 {
 37   const char data[]=__DATE__;
 38   const char tempo[]=__TIME__;
 39   const char nomes[] = "JanFebMarAprMayJunJulAugSepOctNovDec";
 40   char omes[4];
 41   int ano, mes, dia, hora, min, seg;
 42 
 43   if(strcmp(sversion,"9999.9999.20150710.045535"))
 44     return sversion;
 45 
 46   if(strlen(data)!=11||strlen(tempo)!=8)
 47     return NULL;
 48 
 49   sscanf(data, "%s %d %d", omes, &dia, &ano);
 50   sscanf(tempo, "%d:%d:%d", &hora, &min, &seg);
 51   mes=(strstr(nomes, omes)-nomes)/3+1;
 52   sprintf(sversion,"%d.%d.%04d%02d%02d.%02d%02d%02d", MAJOR, MINOR, ano, mes, dia, hora, min, seg);
 53 
 54   return sversion;
 55 }
 56 #endif

Please note that the string is limited by MAJOR<=9999 and MINOR<=9999. Of course, I set this high value that will hopefully never overflow. But using double is still better (plus, it's completely automatic, no need to set MAJOR and MINOR by hand).

Now, the program above is a bit too much. Better is to remove the function completely, and guarantee that the macro VERSION is defined, either by -DVERSION directly into GCC command line (or an alias that automatically add it so you can't forget), or the recommended solution, to include this process into a makefile.

Here it is the makefile I use:


MakeFile source:

  1   MAJOR = 3
  2   MINOR = 33
  3   BUILD = $(shell date +"%Y%m%d.%H%M%S")
  4   VERSION = "\"$(MAJOR).$(MINOR).$(BUILD)\""
  5   CC = gcc
  6   CFLAGS = -Wall -Wextra -g -O0 -ansi -pedantic-errors
  7   CPPFLAGS = -DVERSION=$(VERSION)
  8   LDLIBS =
  9   
 10    %.x : %.c
 11          $(CC) $(CFLAGS) $(CPPFLAGS) $(LDLIBS) $^ -o $@

A better version with DOUBLE

Now that I presented you "your" preferred solution, here it is my solution:

Compile with (a) makefile or (b) gcc directly:

(a) MakeFile:

   VERSION = $(shell date +"%g%m%d.%H%M%S")
   CC = gcc
   CFLAGS = -Wall -Wextra -g -O0 -ansi -pedantic-errors 
   CPPFLAGS = -DVERSION=$(VERSION)
   LDLIBS =
   %.x : %.c
         $(CC) $(CFLAGS) $(CPPFLAGS) $(LDLIBS) $^ -o $@

(b) Or a simple bash command:

 $ gcc program.c -o program.x -Wall -Wextra -g -O0 -ansi -pedantic-errors -DVERSION=$(date +"%g%m%d.%H%M%S")

Source code (double version):

#ifndef VERSION
  #define VERSION version()
#endif

double version(void);

int main(void)
{
  printf("VERSION%s: '%13.6f'\n", (FUNC_VERSION?"()":""), VERSION);
  return 0;
}

double version(void)
{
  const char data[]=__DATE__;
  const char tempo[]=__TIME__;
  const char nomes[] = "JanFebMarAprMayJunJulAugSepOctNovDec";
  char omes[4];
  int ano, mes, dia, hora, min, seg;
  char sversion[]="130910.001339";
  double fv;

  if(strlen(data)!=11||strlen(tempo)!=8)
    return -1.0;

  sscanf(data, "%s %d %d", omes, &dia, &ano);
  sscanf(tempo, "%d:%d:%d", &hora, &min, &seg);
  mes=(strstr(nomes, omes)-nomes)/3+1;
  sprintf(sversion,"%04d%02d%02d.%02d%02d%02d", ano, mes, dia, hora, min, seg);
  fv=atof(sversion);

  return fv;
}

Note: this double function is there only in case you forget to define macro VERSION. If you use a makefile or set an alias gcc gcc -DVERSION=$(date +"%g%m%d.%H%M%S"), you can safely delete this function completely.


Well, that's it. A very neat and easy way to setup your version control and never worry about it again!

How to implement debounce in Vue2?

In case you need to apply a dynamic delay with the lodash's debounce function:

props: {
  delay: String
},

data: () => ({
  search: null
}),

created () {
     this.valueChanged = debounce(function (event) {
      // Here you have access to `this`
      this.makeAPIrequest(event.target.value)
    }.bind(this), this.delay)

},

methods: {
  makeAPIrequest (newVal) {
    // ...
  }
}

And the template:

<template>
  //...

   <input type="text" v-model="search" @input="valueChanged" />

  //...
</template>

NOTE: in the example above I made an example of search input which can call the API with a custom delay which is provided in props

How to properly seed random number generator

If your aim is just to generate a sting of random number then I think it's unnecessary to complicate it with multiple function calls or resetting seed every time.

The most important step is to call seed function just once before actually running rand.Init(x). Seed uses the provided seed value to initialize the default Source to a deterministic state. So, It would be suggested to call it once before the actual function call to pseudo-random number generator.

Here is a sample code creating a string of random numbers

package main 
import (
    "fmt"
    "math/rand"
    "time"
)



func main(){
    rand.Seed(time.Now().UnixNano())

    var s string
    for i:=0;i<10;i++{
    s+=fmt.Sprintf("%d ",rand.Intn(7))
    }
    fmt.Printf(s)
}

The reason I used Sprintf is because it allows simple string formatting.

Also, In rand.Intn(7) Intn returns, as an int, a non-negative pseudo-random number in [0,7).

how to open a page in new tab on button click in asp.net?

Use JavaScript for the main form / Button click event. An example is:

Context.Response.Write("<script language='javascript'>window.open('AccountsStmt.aspx?showledger=" & sledgerGrp & "','_newtab');</script>")

SOAP client in .NET - references or examples?

Take a look at "using WCF Services with PHP". It explains the basics of what you need.

As a theory summary:

WCF or Windows Communication Foundation is a technology that allow to define services abstracted from the way - the underlying communication method - they'll be invoked.

The idea is that you define a contract about what the service does and what the service offers and also define another contract about which communication method is used to actually consume the service, be it TCP, HTTP or SOAP.

You have the first part of the article here, explaining how to create a very basic WCF Service.

More resources:

Using WCF with PHP5.

Aslo take a look to NuSOAP. If you now NuSphere this is a toolkit to let you connect from PHP to an WCF service.

C++ catching all exceptions

This is how you can reverse-engineer the exception type from within catch(...) should you need to (may be useful when catching unknown from a third party library) with GCC:

#include <iostream>

#include <exception>
#include <typeinfo>
#include <stdexcept>

int main()
{
    try {
        throw ...; // throw something
    }
    catch(...)
    {
        std::exception_ptr p = std::current_exception();
        std::clog <<(p ? p.__cxa_exception_type()->name() : "null") << std::endl;
    }
    return 1;
}

and if you can afford using Boost you can make your catch section even simpler (on the outside) and potentially cross-platform

catch (...)
{
    std::clog << boost::current_exception_diagnostic_information() << std::endl;
}

RedirectToAction with parameter

....

int parameter = Convert.ToInt32(Session["Id"].ToString());

....

return RedirectToAction("ActionName", new { Id = parameter });

Generating combinations in c++

A simple way using std::next_permutation:

#include <iostream>
#include <algorithm>
#include <vector>

int main() {
    int n, r;
    std::cin >> n;
    std::cin >> r;

    std::vector<bool> v(n);
    std::fill(v.end() - r, v.end(), true);

    do {
        for (int i = 0; i < n; ++i) {
            if (v[i]) {
                std::cout << (i + 1) << " ";
            }
        }
        std::cout << "\n";
    } while (std::next_permutation(v.begin(), v.end()));
    return 0;
}

or a slight variation that outputs the results in an easier to follow order:

#include <iostream>
#include <algorithm>
#include <vector>

int main() {
   int n, r;
   std::cin >> n;
   std::cin >> r;

   std::vector<bool> v(n);
   std::fill(v.begin(), v.begin() + r, true);

   do {
       for (int i = 0; i < n; ++i) {
           if (v[i]) {
               std::cout << (i + 1) << " ";
           }
       }
       std::cout << "\n";
   } while (std::prev_permutation(v.begin(), v.end()));
   return 0;
}

A bit of explanation:

It works by creating a "selection array" (v), where we place r selectors, then we create all permutations of these selectors, and print the corresponding set member if it is selected in in the current permutation of v.


You can implement it if you note that for each level r you select a number from 1 to n.

In C++, we need to 'manually' keep the state between calls that produces results (a combination): so, we build a class that on construction initialize the state, and has a member that on each call returns the combination while there are solutions: for instance

#include <iostream>
#include <iterator>
#include <vector>
#include <cstdlib>

using namespace std;

struct combinations
{
    typedef vector<int> combination_t;

    // initialize status
   combinations(int N, int R) :
       completed(N < 1 || R > N),
       generated(0),
       N(N), R(R)
   {
       for (int c = 1; c <= R; ++c)
           curr.push_back(c);
   }

   // true while there are more solutions
   bool completed;

   // count how many generated
   int generated;

   // get current and compute next combination
   combination_t next()
   {
       combination_t ret = curr;

       // find what to increment
       completed = true;
       for (int i = R - 1; i >= 0; --i)
           if (curr[i] < N - R + i + 1)
           {
               int j = curr[i] + 1;
               while (i <= R-1)
                   curr[i++] = j++;
               completed = false;
               ++generated;
               break;
           }

       return ret;
   }

private:

   int N, R;
   combination_t curr;
};

int main(int argc, char **argv)
{
    int N = argc >= 2 ? atoi(argv[1]) : 5;
    int R = argc >= 3 ? atoi(argv[2]) : 2;
    combinations cs(N, R);
    while (!cs.completed)
    {
        combinations::combination_t c = cs.next();
        copy(c.begin(), c.end(), ostream_iterator<int>(cout, ","));
        cout << endl;
    }
    return cs.generated;
}

test output:

1,2,
1,3,
1,4,
1,5,
2,3,
2,4,
2,5,
3,4,
3,5,
4,5,

UnicodeEncodeError: 'latin-1' codec can't encode character

You are trying to store a Unicode codepoint \u201c using an encoding ISO-8859-1 / Latin-1 that can't describe that codepoint. Either you might need to alter the database to use utf-8, and store the string data using an appropriate encoding, or you might want to sanitise your inputs prior to storing the content; i.e. using something like Sam Ruby's excellent i18n guide. That talks about the issues that windows-1252 can cause, and suggests how to process it, plus links to sample code!

What does "use strict" do in JavaScript, and what is the reasoning behind it?

JavaScript “strict” mode was introduced in ECMAScript 5.

(function() {
  "use strict";
  your code...
})();

Writing "use strict"; at the very top of your JS file turns on strict syntax checking. It does the following tasks for us:

  1. shows an error if you try to assign to an undeclared variable

  2. stops you from overwriting key JS system libraries

  3. forbids some unsafe or error-prone language features

use strict also works inside of individual functions. It is always a better practice to include use strict in your code.

Browser compatibility issue: The "use" directives are meant to be backwards-compatible. Browsers that do not support them will just see a string literal that isn't referenced further. So, they will pass over it and move on.

Array[n] vs Array[10] - Initializing array with variable vs real number

In C++, variable length arrays are not legal. G++ allows this as an "extension" (because C allows it), so in G++ (without being -pedantic about following the C++ standard), you can do:

int n = 10;
double a[n]; // Legal in g++ (with extensions), illegal in proper C++

If you want a "variable length array" (better called a "dynamically sized array" in C++, since proper variable length arrays aren't allowed), you either have to dynamically allocate memory yourself:

int n = 10;
double* a = new double[n]; // Don't forget to delete [] a; when you're done!

Or, better yet, use a standard container:

int n = 10;
std::vector<double> a(n); // Don't forget to #include <vector>

If you still want a proper array, you can use a constant, not a variable, when creating it:

const int n = 10;
double a[n]; // now valid, since n isn't a variable (it's a compile time constant)

Similarly, if you want to get the size from a function in C++11, you can use a constexpr:

constexpr int n()
{
    return 10;
}

double a[n()]; // n() is a compile time constant expression

Tests not running in Test Explorer

Had the same symptoms, in my case it was the dotnet core SDK version that was the problem.

The projects was targeting 2.2, and was able to build using 3.0. After installing newest 2.2 SDK version they were able to run.

how to get value of selected item in autocomplete

$(document).ready(function () {
    $('#tags').on('change', function () {
        $('#tagsname').html('You selected: ' + this.value);
    }).change();
    $('#tags').on('blur', function (e, ui) {
        $('#tagsname').html('You selected: ' + ui.item.value);
    });
});

Create multiple threads and wait all of them to complete

I don't know if there is a better way, but the following describes how I did it with a counter and background worker thread.

private object _lock = new object();
private int _runningThreads = 0;

private int Counter{
    get{
        lock(_lock)
            return _runningThreads;
    }
    set{
        lock(_lock)
            _runningThreads = value;
    }
}

Now whenever you create a worker thread, increment the counter:

var t = new BackgroundWorker();
// Add RunWorkerCompleted handler

// Start thread
Counter++;

In work completed, decrement the counter:

private void RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
    Counter--;
}

Now you can check for the counter anytime to see if any thread is running:

if(Couonter>0){
    // Some thread is yet to finish.
}

How to update large table with millions of rows in SQL Server?

First of all, thank you all for your inputs. I tweak my Query - 1 and got my desired result. Gordon Linoff is right, PRINT was messing up my query so I modified it as following:

Modified Query - 1:

SET ROWCOUNT 5
WHILE (1 = 1)
  BEGIN
    BEGIN TRANSACTION

        UPDATE TableName 
        SET Value = 'abc1' 
        WHERE Parameter1 = 'abc' AND Parameter2 = 123

        IF @@ROWCOUNT = 0
          BEGIN
                COMMIT TRANSACTION
                BREAK
          END
    COMMIT TRANSACTION
  END
SET ROWCOUNT  0

Output:

(5 row(s) affected)

(5 row(s) affected)

(4 row(s) affected)

(0 row(s) affected)

Calling a function of a module by using its name (a string)

Patrick's solution is probably the cleanest. If you need to dynamically pick up the module as well, you can import it like:

module = __import__('foo')
func = getattr(module, 'bar')
func()

Is there a good Valgrind substitute for Windows?

More or less all Profilers include checking for memory leaks and show you the stack when the memory was allocated.

I can recommend Intels Parallel Inspector. Simple to use and no recompilation needed. The trial version runs for 30 days.

GlowCode and AtromatedQA also include such capabilites. They all offer free trials.

Compuware DevPartner (aka BoundsChecker) in Contrast needs a slowed down "instrumentation" recompile and the application also runs slower when checking for errors. And BoundsChecker can not work with 64 Bit evsrions at all. We gave up on that tool.

Validate fields after user has left a field

Angular 1.3 now has ng-model-options, and you can set the option to { 'updateOn': 'blur'} for example, and you can even debounce, when the use is either typing too fast, or you want to save a few expensive DOM operations (like a model writing to multiple DOM places and you don't want a $digest cycle happening on every key down)

https://docs.angularjs.org/guide/forms#custom-triggers and https://docs.angularjs.org/guide/forms#non-immediate-debounced-model-updates

By default, any change to the content will trigger a model update and form validation. You can override this behavior using the ngModelOptions directive to bind only to specified list of events. I.e. ng-model-options="{ updateOn: 'blur' }" will update and validate only after the control loses focus. You can set several events using a space delimited list. I.e. ng-model-options="{ updateOn: 'mousedown blur' }"

And debounce

You can delay the model update/validation by using the debounce key with the ngModelOptions directive. This delay will also apply to parsers, validators and model flags like $dirty or $pristine.

I.e. ng-model-options="{ debounce: 500 }" will wait for half a second since the last content change before triggering the model update and form validation.

get and set in TypeScript

I think I probably get why is it so confusing. In your example, we wanted getters and setters for _name. But we achieve that by creating getters and setters for an unrelated class variable Name.

Consider this:

class Car{
    private tiresCount = 4;
    get yourCarTiresCount(){
        return this.tiresCount ;
    }
    set yourCarTiresCount(count) {
        alert('You shouldn't change car tire count')
    }
}

Above code does following:

  1. get and set create getter and setter for yourCarTiresCount (not for tiresCount).

The getter is :

function() {
    return this.tiresCount ;
}

and the setter is :

function(count) {
    alert('You shouldn't change car tire count');
}

Meaning, every time we do new Car().yourCarTiresCount, getter runs. And for every new Car().yourCarTiresCount('7') setter runs.

  1. Indirectly create getter, but not the setter, for private tireCount.

Curl to return http status code along with the response

I was able to get a solution by looking at the curl doc which specifies to use - for the output to get the output to stdout.

curl -o - http://localhost

To get the response with just the http return code, I could just do

curl -o /dev/null -s -w "%{http_code}\n" http://localhost

How to import data from text file to mysql database

The LOAD DATA INFILE statement reads rows from a text file into a table at a very high speed.

LOAD DATA INFILE '/tmp/test.txt' 
INTO TABLE test
FIELDS TERMINATED BY ','
LINES STARTING BY 'xxx';

If the data file looks like this:

xxx"abc",1
something xxx"def",2
"ghi",3

The resulting rows will be ("abc",1) and ("def",2). The third row in the file is skipped because it does not contain the prefix.

LOAD DATA INFILE 'data.txt'
INTO TABLE tbl_name
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY '\r\n'

You can also load data files by using the mysqlimport utility; it operates by sending a LOAD DATA INFILE statement to the server

mysqlimport -u root -ptmppassword --local test employee.txt

test.employee: Records: 3  Deleted: 0  Skipped: 0  Warnings: 0

How to use the start command in a batch file?

An extra pair of rabbits' ears should do the trick.

start "" "C:\Program...

START regards the first quoted parameter as the window-title, unless it's the only parameter - and any switches up until the executable name are regarded as START switches.

How to install and run phpize

For ubuntu with Plesk installed run apt-get install plesk-php56-dev, for other versions just change XX in phpXX (without the dot)

Resizing an Image without losing any quality

Unless you're doing vector graphics, there's no way to resize an image without potentially losing some image quality.

Multiple submit buttons in an HTML form

Instead of struggling with multiple submits, JavaScript or anything like that to do some previous/next stuff, an alternative would be to use a carousel to simulate the different pages. Doing this :

  • You don't need multiple buttons, inputs or submits to do the previous/next thing, you have only one input type="submit" in only one form.
  • The values in the whole form are there until the form is submitted.
  • The user can go to any previous page and any next page flawlessly to modify the values.

Example using Bootstrap 5.0.0 :

<div id="carousel" class="carousel slide" data-ride="carousel">
    <form action="index.php" method="post" class="carousel-inner">
        <div class="carousel-item active">
            <input type="text" name="lastname" placeholder="Lastname"/>
        </div>
        <div class="carousel-item">
            <input type="text" name="firstname" placeholder="Firstname"/>
        </div>
        <div class="carousel-item">
            <input type="submit" name="submit" value="Submit"/>
        </div>
    </form>
    <a class="btn-secondary" href="#carousel" role="button" data-slide="prev">Previous page</a>
    <a class="btn-primary" href="#carousel" role="button" data-slide="next">Next page</a>
</div>

CSS How to set div height 100% minus nPx

great one... now i have stopped using % he he he... except for the main container as shown below:

<div id="divContainer">
    <div id="divHeader">
    </div>
    <div id="divContentArea">
        <div id="divContentLeft">
        </div>
        <div id="divContentRight">
        </div>
    </div>
    <div id="divFooter">
    </div>
</div>

and here is the css:

#divContainer {
    width: 100%;
    height: 100%;
}
#divHeader {
    position: absolute;
    left: 0px;
    top: 0px;
    right: 0px;
    height: 28px;
}
#divContentArea {
    position: absolute;
    left: 0px;
    top: 30px;
    right: 0px;
    bottom: 30px;
}
#divContentLeft {
    position: absolute;
    top: 0px;
    left: 0px;
    width: 250px;
    bottom: 0px;
}
#divContentRight {
    position: absolute;
    top: 0px;
    left: 254px;
    right: 0px;
    bottom: 0px;
}
#divFooter {
    position: absolute;
    height: 28px;
    left: 0px;
    bottom: 0px;
    right: 0px;
}

i tested this in all known browsers and is working fine. Are there any drawbacks using this way?

How to install latest version of Node using Brew

I had to do brew link --overwrite node after brew install node to update from 0.4 to 0.8.18

How to count duplicate rows in pandas dataframe?

I use:

used_features =[
    "one",
    "two",
    "three"
]

df['is_duplicated'] = df.duplicated(used_features)
df['is_duplicated'].sum()

which gives count of duplicated rows, and then you can analyse them by a new column. I didn't see such solution here.

Text editor to open big (giant, huge, large) text files

Free read-only viewers:

  • Large Text File Viewer (Windows) – Fully customizable theming (colors, fonts, word wrap, tab size). Supports horizontal and vertical split view. Also support file following and regex search. Very fast, simple, and has small executable size.
  • klogg (Windows, macOS, Linux) – A maintained fork of glogg, its main feature is regular expression search. It can also watch files, allows the user to mark lines, and has serious optimizations built in. But from a UI standpoint, it's ugly and clunky.
  • LogExpert (Windows) – "A GUI replacement for tail." It's really a log file analyzer, not a large file viewer, and in one test it required 10 seconds and 700 MB of RAM to load a 250 MB file. But its killer features are the columnizer (parse logs that are in CSV, JSONL, etc. and display in a spreadsheet format) and the highlighter (show lines with certain words in certain colors). Also supports file following, tabs, multifiles, bookmarks, search, plugins, and external tools.
  • Lister (Windows) – Very small and minimalist. It's one executable, barely 500 KB, but it still supports searching (with regexes), printing, a hex editor mode, and settings.
  • loxx (Windows) – Supports file following, highlighting, line numbers, huge files, regex, multiple files and views, and much more. The free version can not: process regex, filter files, synchronize timestamps, and save changed files.

Free editors:

  • Your regular editor or IDE. Modern editors can handle surprisingly large files. In particular, Vim (Windows, macOS, Linux), Emacs (Windows, macOS, Linux), Notepad++ (Windows), Sublime Text (Windows, macOS, Linux), and VS Code (Windows, macOS, Linux) support large (~4 GB) files, assuming you have the RAM.
  • Large File Editor (Windows) – Opens and edits TB+ files, supports Unicode, uses little memory, has XML-specific features, and includes a binary mode.
  • GigaEdit (Windows) – Supports searching, character statistics, and font customization. But it's buggy – with large files, it only allows overwriting characters, not inserting them; it doesn't respect LF as a line terminator, only CRLF; and it's slow.

Builtin programs (no installation required):

  • less (macOS, Linux) – The traditional Unix command-line pager tool. Lets you view text files of practically any size. Can be installed on Windows, too.
  • Notepad (Windows) – Decent with large files, especially with word wrap turned off.
  • MORE (Windows) – This refers to the Windows MORE, not the Unix more. A console program that allows you to view a file, one screen at a time.

Web viewers:

Paid editors:

  • 010 Editor (Windows, macOS, Linux) – Opens giant (as large as 50 GB) files.
  • SlickEdit (Windows, macOS, Linux) – Opens large files.
  • UltraEdit (Windows, macOS, Linux) – Opens files of more than 6 GB, but the configuration must be changed for this to be practical: Menu » Advanced » Configuration » File Handling » Temporary Files » Open file without temp file...
  • EmEditor (Windows) – Handles very large text files nicely (officially up to 248 GB, but as much as 900 GB according to one report).
  • BssEditor (Windows) – Handles large files and very long lines. Don’t require an installation. Free for non commercial use.

How to get a cookie from an AJAX response?

xhr.getResponseHeader('Set-Cookie');

It won't work for me.

I use this

function getCookie(cname) {
    var name = cname + "=";
    var ca = document.cookie.split(';');
    for(var i=0; i<ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1);
        if (c.indexOf(name) != -1) return c.substring(name.length,c.length);
    }
    return "";
} 

success: function(output, status, xhr) {
    alert(getCookie("MyCookie"));
},

http://www.w3schools.com/js/js_cookies.asp

List Directories and get the name of the Directory

Listing the entries in the current directory (for directories in os.listdir(os.getcwd()):) and then interpreting those entries as subdirectories of an entirely different directory (dir = os.path.join('/home/user/workspace', directories)) is one thing that looks fishy.

Using a BOOL property

Apple recommends for stylistic purposes.If you write this code:

@property (nonatomic,assign) BOOL working;

Then you can not use [object isWorking].
It will show an error. But if you use below code means

@property (assign,getter=isWorking) BOOL working;

So you can use [object isWorking] .

How to check for the type of a template parameter?

std::is_same() is only available since C++11. For pre-C++11 you can use typeid():

template <typename T>
void foo()
{
    if (typeid(T) == typeid(animal)) { /* ... */ }
}

How to insert current datetime in postgresql insert query

For current datetime, you can use now() function in postgresql insert query.

You can also refer following link.

insert statement in postgres for data type timestamp without time zone NOT NULL,.

c# regex matches example

Regex regex = new Regex("%download#(\\d+?)%", RegexOptions.SingleLine);
Matches m = regex.Matches(input);

I think will do the trick (not tested).

What is “2's Complement”?

Two complement is found out by adding one to 1'st complement of the given number. Lets say we have to find out twos complement of 10101 then find its ones complement, that is, 01010 add 1 to this result, that is, 01010+1=01011, which is the final answer.

Mean Squared Error in Numpy?

Another alternative to the accepted answer that avoids any issues with matrix multiplication:

 def MSE(Y, YH):
     return np.square(Y - YH).mean()

From the documents for np.square: "Return the element-wise square of the input."

What does it mean when MySQL is in the state "Sending data"?

This is quite a misleading status. It should be called "reading and filtering data".

This means that MySQL has some data stored on the disk (or in memory) which is yet to be read and sent over. It may be the table itself, an index, a temporary table, a sorted output etc.

If you have a 1M records table (without an index) of which you need only one record, MySQL will still output the status as "sending data" while scanning the table, despite the fact it has not sent anything yet.

The 'json' native gem requires installed build tools

I would like to add that you should make sure that the generated config.yml file when doing ruby dk.rb init contains the path to the ruby installation you want to use DevKit with. In my case, I had the Heroku Toolbelt installed on my system, which provided its own ruby installation, located at a different place. The config.yml file used that particular installation, and that's not what I wanted. I had to manually edit the file to point it to the correct one, then continue with ruby dk.rb review, etc.

How do I get the scroll position of a document?

To get the actual scrollable height of the areas scrolled by the window scrollbar, I used $('body').prop('scrollHeight'). This seems to be the simplest working solution, but I haven't checked extensively for compatibility. Emanuele Del Grande notes on another solution that this probably won't work for IE below 8.

Most of the other solutions work fine for scrollable elements, but this works for the whole window. Notably, I had the same issue as Michael for Ankit's solution, namely, that $(document).prop('scrollHeight') is returning undefined.

Getting file names without extensions

if file name contains directory and you need to not lose directory:

fileName.Remove(fileName.LastIndexOf("."))

Format decimal for percentage values?

This code may help you:

double d = double.Parse(input_value);
string output= d.ToString("F2", CultureInfo.InvariantCulture) + "%";

Fit Image into PictureBox

Use the following lines of codes and you will find the solution...

pictureBox1.ImageLocation = @"C:\Users\Desktop\mypicture.jpg";
pictureBox1.SizeMode =PictureBoxSizeMode.StretchImage;

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

Basically both suggested solutions work fine in most cases. My main negative experience with ngOnChange() is the lack of type safety.

In one of my projects I did some renaming, following which some of the magic strings remained unchanged, and the bug of course took some time to surface.

Setters do not have that issue: your IDE or compiler will let you know of any mismatch.

Hide separator line on one UITableViewCell

Using Swift 3 and adopting the fastest hacking-method, you can improve code using extensions:

extension UITableViewCell {

    var isSeparatorHidden: Bool {
        get {
            return self.separatorInset.right != 0
        }
        set {
            if newValue {
                self.separatorInset = UIEdgeInsetsMake(0, self.bounds.size.width, 0, 0)
            } else {
                self.separatorInset = UIEdgeInsetsMake(0, 0, 0, 0)
            }
        }
    }

}

Then, when you configure cell:

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "identifier", for: indexPath)
    switch indexPath.row {
       case 3:
          cell.isSeparatorHidden = true
       default:
          cell.isSeparatorHidden = false
    }
    return cell
}

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    let cell = tableView.cellForRow(at: indexPath)
    if cell.isSeparatorHidden { 
       // do stuff
    }
}

Get date from input form within PHP

    <?php
if (isset($_POST['birthdate'])) {
    $timestamp = strtotime($_POST['birthdate']); 
    $date=date('d',$timestamp);
    $month=date('m',$timestamp);
    $year=date('Y',$timestamp);
}
?>  

Python conversion from binary string to hexadecimal

This overview can be useful for someone: bin, dec, hex in python to convert between bin, dec, hex in python.

I would do:

dec_str = format(int('0000010010001101', 2),'x')
dec_str.rjust(4,'0')

Result: '048d'

What is the significance of load factor in HashMap?

For HashMap DEFAULT_INITIAL_CAPACITY = 16 and DEFAULT_LOAD_FACTOR = 0.75f it means that MAX number of ALL Entries in the HashMap = 16 * 0.75 = 12. When the thirteenth element will be added capacity (array size) of HashMap will be doubled! Perfect illustration answered this question: enter image description here image is taken from here:

https://javabypatel.blogspot.com/2015/10/what-is-load-factor-and-rehashing-in-hashmap.html

how to pass parameter from @Url.Action to controller function

should you pass it in this way :

public ActionResult CreatePerson(int id) //controller 
window.location.href = "@Url.Action("CreatePerson", "Person",new { @id = 1});

How to check if a file exists from inside a batch file

Try something like the following example, quoted from the output of IF /? on Windows XP:

IF EXIST filename. (
    del filename.
) ELSE (
    echo filename. missing.
)

You can also check for a missing file with IF NOT EXIST.

The IF command is quite powerful. The output of IF /? will reward careful reading. For that matter, try the /? option on many of the other built-in commands for lots of hidden gems.  

Equivalent of varchar(max) in MySQL?

The max length of a varchar is subject to the max row size in MySQL, which is 64KB (not counting BLOBs):

VARCHAR(65535)

However, note that the limit is lower if you use a multi-byte character set:

VARCHAR(21844) CHARACTER SET utf8

Here are some examples:

The maximum row size is 65535, but a varchar also includes a byte or two to encode the length of a given string. So you actually can't declare a varchar of the maximum row size, even if it's the only column in the table.

mysql> CREATE TABLE foo ( v VARCHAR(65534) );
ERROR 1118 (42000): Row size too large. The maximum row size for the used table type, not counting BLOBs, is 65535. This includes storage overhead, check the manual. You have to change some columns to TEXT or BLOBs

But if we try decreasing lengths, we find the greatest length that works:

mysql> CREATE TABLE foo ( v VARCHAR(65532) );
Query OK, 0 rows affected (0.01 sec)

Now if we try to use a multibyte charset at the table level, we find that it counts each character as multiple bytes. UTF8 strings don't necessarily use multiple bytes per string, but MySQL can't assume you'll restrict all your future inserts to single-byte characters.

mysql> CREATE TABLE foo ( v VARCHAR(65532) ) CHARSET=utf8;
ERROR 1074 (42000): Column length too big for column 'v' (max = 21845); use BLOB or TEXT instead

In spite of what the last error told us, InnoDB still doesn't like a length of 21845.

mysql> CREATE TABLE foo ( v VARCHAR(21845) ) CHARSET=utf8;
ERROR 1118 (42000): Row size too large. The maximum row size for the used table type, not counting BLOBs, is 65535. This includes storage overhead, check the manual. You have to change some columns to TEXT or BLOBs

This makes perfect sense, if you calculate that 21845*3 = 65535, which wouldn't have worked anyway. Whereas 21844*3 = 65532, which does work.

mysql> CREATE TABLE foo ( v VARCHAR(21844) ) CHARSET=utf8;
Query OK, 0 rows affected (0.32 sec)

How to convert current date to epoch timestamp?

from time import time
>>> int(time())
1542449530


>>> time()
1542449527.6991141
>>> int(time())
1542449530
>>> str(time()).replace(".","")
'154244967282'

But Should it not return ?

'15424495276991141'

Babel command not found

This worked for me inside package.json as an npm script but it does seem to take to long grabbing the packages even though I have them as dev dependancies. It also seems too long.

"babel": "npx -p @babel/cli -p @babel/core babel --version"

What end up solving it was much simpler but funny too

npm install

I thought I ran that already but I guess somethings needed to be rebuilt. Then just:

"babel": "babel --version"

How to use bootstrap datepicker

man you can use the basic Bootstrap Datepicker this way:

<!DOCTYPE html>
<head runat="server">
<title>Test Zone</title>
<link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css"/>
<link rel="stylesheet" type="text/css" href="Css/datepicker.css" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.2/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
<script src="../Js/bootstrap-datepicker.js"></script>
<script type="text/javascript">
    $(document).ready(function () {
        $('#pickyDate').datepicker({
            format: "dd/mm/yyyy"
        });
    });
</script>

and inside body:

<body>
<div id="testDIV">
    <div class="container">
        <div class="hero-unit">
            <input  type="text" placeholder="click to show datepicker"  id="pickyDate"/>
        </div>
    </div>
</div>

datepicker.css and bootstrap-datepicker.js you can download from here on the Download button below "About" on the left side. Hope this help someone, greetings.

Using lodash to compare jagged arrays (items existence without order)

PURE JS (works also when arrays and subarrays has more than 2 elements with arbitrary order). If strings contains , use as join('-') parametr character (can be utf) which is not used in strings

array1.map(x=>x.sort()).sort().join() === array2.map(x=>x.sort()).sort().join()

_x000D_
_x000D_
var array1 = [['a', 'b'], ['b', 'c']];_x000D_
var array2 = [['b', 'c'], ['b', 'a']];_x000D_
_x000D_
var r = array1.map(x=>x.sort()).sort().join() === array2.map(x=>x.sort()).sort().join();_x000D_
_x000D_
console.log(r);
_x000D_
_x000D_
_x000D_

SQL - The conversion of a varchar data type to a datetime data type resulted in an out-of-range value

You can make use of

Set dateformat <date-format> ;

in you sp function or stored procedure to get things done.

Scroll to bottom of Div on page load (jQuery)

Scroll window to the bottom of target div.

function scrollToBottom(id){
  div_height = $("#"+id).height();
  div_offset = $("#"+id).offset().top;
  window_height = $(window).height();
  $('html,body').animate({
    scrollTop: div_offset-window_height+div_height
  },'slow');
}

scrollToBottom('call_div_id');

How can I convert a string to upper- or lower-case with XSLT?

In XSLT 1.0 the upper-case() and lower-case() functions are not available. If you're using a 1.0 stylesheet the common method of case conversion is translate():

<xsl:variable name="lowercase" select="'abcdefghijklmnopqrstuvwxyz'" />
<xsl:variable name="uppercase" select="'ABCDEFGHIJKLMNOPQRSTUVWXYZ'" />


<xsl:template match="/">
  <xsl:value-of select="translate(doc, $lowercase, $uppercase)" />
</xsl:template>

document.getElementById().value and document.getElementById().checked not working for IE

Have a look at jQuery, a cross-browser library that will make your life a lot easier.

var msg = 'abc';
$('#msg').val(msg);
$('#sp_100').attr('checked', 'checked');

assign value using linq

You can create a extension method:

public static IEnumerable<T> Do<T>(this IEnumerable<T> self, Action<T> action) {
    foreach(var item in self) {
        action(item);
        yield return item;
    }
}

And then use it in code:

listofCompany.Do(d=>d.Id = 1);
listofCompany.Where(d=>d.Name.Contains("Inc")).Do(d=>d.Id = 1);

FB OpenGraph og:image not pulling images (possibly https?)

Similar symptoms (Facebook et al not correctly fetching og:image and other assets over https) can occur when the site's https certificate is not fully compliant.

Your site's https cert may seem valid (green key in the browser and all), but it will not scrape correctly if it's missing an intermediate or chain certificate. This can lead to many wasted hours checking and rechecking all the various caches and meta tags.

Might not have been your problem, but could be other's with similar symptoms (like mine). There's many ways to check your cert - the one I happened to use: https://www.sslshopper.com/ssl-checker.html

jquery AJAX and json format

I never had any luck with that approach. I always do this (hope this helps):

var obj = {};

obj.first_name = $("#namec").val();
obj.last_name = $("#surnamec").val();
obj.email = $("#emailc").val();
obj.mobile = $("#numberc").val();
obj.password = $("#passwordc").val();

Then in your ajax:

$.ajax({
        type: "POST",
        url: hb_base_url + "consumer",
        contentType: "application/json",
        dataType: "json",
        data: JSON.stringify(obj),
        success: function(response) {
            console.log(response);
        },
        error: function(response) {
            console.log(response);
        }
    });

Why is semicolon allowed in this python snippet?

http://docs.python.org/reference/compound_stmts.html

Compound statements consist of one or more ‘clauses.’ A clause consists of a header and a ‘suite.’ The clause headers of a particular compound statement are all at the same indentation level. Each clause header begins with a uniquely identifying keyword and ends with a colon. A suite is a group of statements controlled by a clause. A suite can be one or more semicolon-separated simple statements on the same line as the header, following the header’s colon, or it can be one or more indented statements on subsequent lines. Only the latter form of suite can contain nested compound statements; the following is illegal, mostly because it wouldn’t be clear to which if clause a following else clause would belong:

if test1: if test2: print x

Also note that the semicolon binds tighter than the colon in this context, so that in the following example, either all or none of the print statements are executed:

if x < y < z: print x; print y; print z 

Summarizing:

compound_stmt ::=  if_stmt
                   | while_stmt
                   | for_stmt
                   | try_stmt
                   | with_stmt
                   | funcdef
                   | classdef
                   | decorated
suite         ::=  stmt_list NEWLINE | NEWLINE INDENT statement+ DEDENT
statement     ::=  stmt_list NEWLINE | compound_stmt
stmt_list     ::=  simple_stmt (";" simple_stmt)* [";"]

Is there a way to create key-value pairs in Bash script?

In bash, we use

declare -A name_of_dictonary_variable

so that Bash understands it is a dictionary.

For e.g. you want to create sounds dictionary then,

declare -A sounds

sounds[dog]="Bark"

sounds[wolf]="Howl"

where dog and wolf are "keys", and Bark and Howl are "values".

You can access all values using : echo ${sounds[@]} OR echo ${sounds[*]}

You can access all keys only using: echo ${!sounds[@]}

And if you want any value for a particular key, you can use:

${sounds[dog]}

this will give you value (Bark) for key (Dog).

Nested Recycler view height doesn't wrap its content

UPDATE March 2016

By Android Support Library 23.2.1 of a support library version. So all WRAP_CONTENT should work correctly.

Please update version of a library in gradle file.

compile 'com.android.support:recyclerview-v7:23.2.1'

This allows a RecyclerView to size itself based on the size of its contents. This means that previously unavailable scenarios, such as using WRAP_CONTENT for a dimension of the RecyclerView, are now possible.

you’ll be required to call setAutoMeasureEnabled(true)

Fixed bugs related to various measure-spec methods in update

Check https://developer.android.com/topic/libraries/support-library/features.html

How to clear a notification in Android

 Notification mNotification = new Notification.Builder(this)

                .setContentTitle("A message from: " + fromUser)
                .setContentText(msg)
                .setAutoCancel(true)
                .setSmallIcon(R.drawable.app_icon)
                .setContentIntent(pIntent)
                .build();

.setAutoCancel(true)

when you click on notification, open corresponding activity and remove notification from notification bar

Can You Get A Users Local LAN IP Address Via JavaScript?

Chrome 76+

Last year I used Linblow's answer (2018-Oct-19) to successfully discover my local IP via javascript. However, recent Chrome updates (76?) have wonked this method so that it now returns an obfuscated IP, such as: 1f4712db-ea17-4bcf-a596-105139dfd8bf.local

If you have full control over your browser, you can undo this behavior by turning it off in Chrome Flags, by typing this into your address bar:

chrome://flags

and DISABLING the flag Anonymize local IPs exposed by WebRTC

In my case, I require the IP for a TamperMonkey script to determine my present location and do different things based on my location. I also have full control over my own browser settings (no Corporate Policies, etc). So for me, changing the chrome://flags setting does the trick.

Sources:

https://groups.google.com/forum/#!topic/discuss-webrtc/6stQXi72BEU

https://codelabs.developers.google.com/codelabs/webrtc-web/index.html

How do I convert 2018-04-10T04:00:00.000Z string to DateTime?

Update: Using DateTimeFormat, introduced in java 8:

The idea is to define two formats: one for the input format, and one for the output format. Parse with the input formatter, then format with the output formatter.

Your input format looks quite standard, except the trailing Z. Anyway, let's deal with this: "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'". The trailing 'Z' is the interesting part. Usually there's time zone data here, like -0700. So the pattern would be ...Z, i.e. without apostrophes.

The output format is way more simple: "dd-MM-yyyy". Mind the small y -s.

Here is the example code:

DateTimeFormatter inputFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.ENGLISH);
DateTimeFormatter outputFormatter = DateTimeFormatter.ofPattern("dd-MM-yyy", Locale.ENGLISH);
LocalDate date = LocalDate.parse("2018-04-10T04:00:00.000Z", inputFormatter);
String formattedDate = outputFormatter.format(date);
System.out.println(formattedDate); // prints 10-04-2018

Original answer - with old API SimpleDateFormat

SimpleDateFormat inputFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
SimpleDateFormat outputFormat = new SimpleDateFormat("dd-MM-yyyy");
Date date = inputFormat.parse("2018-04-10T04:00:00.000Z");
String formattedDate = outputFormat.format(date);
System.out.println(formattedDate); // prints 10-04-2018

How to printf long long

    // acos(0.0) will return value of pi/2, inverse of cos(0) is pi/2 
    double pi = 2 * acos(0.0);
    int n; // upto 6 digit
    scanf("%d",&n); //precision with which you want the value of pi
    printf("%.*lf\n",n,pi); // * will get replaced by n which is the required precision

event Action<> vs event EventHandler<>

I realize that this question is over 10 years old, but it appears to me that not only has the most obvious answer not been addressed, but that maybe its not really clear from the question a good understanding of what goes on under the covers. In addition, there are other questions about late binding and what that means with regards to delegates and lambdas (more on that later).

First to address the 800 lb elephant/gorilla in the room, when to choose event vs Action<T>/Func<T>:

  • Use a lambda to execute one statement or method. Use event when you want more of a pub/sub model with multiple statements/lambdas/functions that will execute (this is a major difference right off the bat).
  • Use a lambda when you want to compile statements/functions to expression trees. Use delegates/events when you want to participate in more traditional late binding such as used in reflection and COM interop.

As an example of an event, lets wire up a simple and 'standard' set of events using a small console application as follows:

public delegate void FireEvent(int num);

public delegate void FireNiceEvent(object sender, SomeStandardArgs args);

public class SomeStandardArgs : EventArgs
{
    public SomeStandardArgs(string id)
    {
        ID = id;
    }

    public string ID { get; set; }
}

class Program
{
    public static event FireEvent OnFireEvent;

    public static event FireNiceEvent OnFireNiceEvent;


    static void Main(string[] args)
    {
        OnFireEvent += SomeSimpleEvent1;
        OnFireEvent += SomeSimpleEvent2;

        OnFireNiceEvent += SomeStandardEvent1;
        OnFireNiceEvent += SomeStandardEvent2;


        Console.WriteLine("Firing events.....");
        OnFireEvent?.Invoke(3);
        OnFireNiceEvent?.Invoke(null, new SomeStandardArgs("Fred"));

        //Console.WriteLine($"{HeightSensorTypes.Keyence_IL030}:{(int)HeightSensorTypes.Keyence_IL030}");
        Console.ReadLine();
    }

    private static void SomeSimpleEvent1(int num)
    {
        Console.WriteLine($"{nameof(SomeSimpleEvent1)}:{num}");
    }
    private static void SomeSimpleEvent2(int num)
    {
        Console.WriteLine($"{nameof(SomeSimpleEvent2)}:{num}");
    }

    private static void SomeStandardEvent1(object sender, SomeStandardArgs args)
    {

        Console.WriteLine($"{nameof(SomeStandardEvent1)}:{args.ID}");
    }
    private static void SomeStandardEvent2(object sender, SomeStandardArgs args)
    {
        Console.WriteLine($"{nameof(SomeStandardEvent2)}:{args.ID}");
    }
}

The output will look as follows:

enter image description here

If you did the same with Action<int> or Action<object, SomeStandardArgs>, you would only see SomeSimpleEvent2 and SomeStandardEvent2.

So whats going on inside of event?

If we expand out FireNiceEvent, the compiler is actually generating the following (I have omitted some details with respect to thread synchronization that isn't relevant to this discussion):

   private EventHandler<SomeStandardArgs> _OnFireNiceEvent;

    public void add_OnFireNiceEvent(EventHandler<SomeStandardArgs> handler)
    {
        Delegate.Combine(_OnFireNiceEvent, handler);
    }

    public void remove_OnFireNiceEvent(EventHandler<SomeStandardArgs> handler)
    {
        Delegate.Remove(_OnFireNiceEvent, handler);
    }

    public event EventHandler<SomeStandardArgs> OnFireNiceEvent
    {
        add
        {
            add_OnFireNiceEvent(value)
        }
        remove
        {
            remove_OnFireNiceEvent(value)

        }
    }

The compiler generates a private delegate variable which is not visible to the class namespace in which it is generated. That delegate is what is used for subscription management and late binding participation, and the public facing interface is the familiar += and -= operators we have all come to know and love : )

You can customize the code for the add/remove handlers by changing the scope of the FireNiceEvent delegate to protected. This now allows developers to add custom hooks to the hooks, such as logging or security hooks. This really makes for some very powerful features that now allows for customized accessibility to subscription based on user roles, etc. Can you do that with lambdas? (Actually you can by custom compiling expression trees, but that's beyond the scope of this response).

To address a couple of points from some of the responses here:

  • There really is no difference in the 'brittleness' between changing the args list in Action<T> and changing the properties in a class derived from EventArgs. Either will not only require a compile change, they will both change a public interface and will require versioning. No difference.

  • With respect to which is an industry standard, that depends on where this is being used and why. Action<T> and such is often used in IoC and DI, and event is often used in message routing such as GUI and MQ type frameworks. Note that I said often, not always.

  • Delegates have different lifetimes than lambdas. One also has to be aware of capture... not just with closure, but also with the notion of 'look what the cat dragged in'. This does affect memory footprint/lifetime as well as management a.k.a. leaks.

One more thing, something I referenced earlier... the notion of late binding. You will often see this when using framework like LINQ, regarding when a lambda becomes 'live'. That is very different than late binding of a delegate, which can happen more than once (i.e. the lambda is always there, but binding occurs on demand as often as is needed), as opposed to a lambda, which once it occurs, its done -- the magic is gone, and the method(s)/property(ies) will always bind. Something to keep in mind.

Stratified Train/Test-split in scikit-learn

TL;DR : Use StratifiedShuffleSplit with test_size=0.25

Scikit-learn provides two modules for Stratified Splitting:

  1. StratifiedKFold : This module is useful as a direct k-fold cross-validation operator: as in it will set up n_folds training/testing sets such that classes are equally balanced in both.

Heres some code(directly from above documentation)

>>> skf = cross_validation.StratifiedKFold(y, n_folds=2) #2-fold cross validation
>>> len(skf)
2
>>> for train_index, test_index in skf:
...    print("TRAIN:", train_index, "TEST:", test_index)
...    X_train, X_test = X[train_index], X[test_index]
...    y_train, y_test = y[train_index], y[test_index]
...    #fit and predict with X_train/test. Use accuracy metrics to check validation performance
  1. StratifiedShuffleSplit : This module creates a single training/testing set having equally balanced(stratified) classes. Essentially this is what you want with the n_iter=1. You can mention the test-size here same as in train_test_split

Code:

>>> sss = StratifiedShuffleSplit(y, n_iter=1, test_size=0.5, random_state=0)
>>> len(sss)
1
>>> for train_index, test_index in sss:
...    print("TRAIN:", train_index, "TEST:", test_index)
...    X_train, X_test = X[train_index], X[test_index]
...    y_train, y_test = y[train_index], y[test_index]
>>> # fit and predict with your classifier using the above X/y train/test

What are the main performance differences between varchar and nvarchar SQL Server data types?

For that last few years all of our projects have used NVARCHAR for everything, since all of these projects are multilingual. Imported data from external sources (e.g. an ASCII file, etc.) is up-converted to Unicode before being inserted into the database.

I've yet to encounter any performance-related issues from the larger indexes, etc. The indexes do use more memory, but memory is cheap.

Whether you use stored procedures or construct SQL on the fly ensure that all string constants are prefixed with N (e.g. SET @foo = N'Hello world.';) so the constant is also Unicode. This avoids any string type conversion at runtime.

YMMV.

500 internal server error, how to debug

Try writing all the errors to a file.

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

Something like that.

Detect if HTML5 Video element is playing

Here is what we are using at http://www.develop.com/webcasts to keep people from accidentally leaving the page while a video is playing or paused.

$(document).ready(function() {

    var video = $("video#webcast_video");
    if (video.length <= 0) {
        return;
    }

    window.onbeforeunload = function () {
        var htmlVideo = video[0];
        if (htmlVideo.currentTime < 0.01 || htmlVideo.ended) {
            return null;
        }

        return "Leaving this page will stop your video.";
    };
}

How to print like printf in Python3?

A simpler one.

def printf(format, *values):
    print(format % values )

Then:

printf("Hello, this is my name %s and my age %d", "Martin", 20)

Simplest way to merge ES6 Maps/Sets?

merge to Map

 let merge = {...map1,...map2};

Inserting string at position x of another string

try

a.slice(0,position) + b + a.slice(position)

_x000D_
_x000D_
var a = "I want apple";_x000D_
var b = " an";_x000D_
var position = 6;_x000D_
_x000D_
var r= a.slice(0,position) + b + a.slice(position);_x000D_
_x000D_
console.log(r);
_x000D_
_x000D_
_x000D_

or regexp solution

"I want apple".replace(/^(.{6})/,"$1 an")

_x000D_
_x000D_
var a = "I want apple";_x000D_
var b = " an";_x000D_
var position = 6;_x000D_
_x000D_
var r= a.replace(new RegExp(`^(.{${position}})`),"$1"+b);_x000D_
_x000D_
console.log(r);_x000D_
console.log("I want apple".replace(/^(.{6})/,"$1 an"));
_x000D_
_x000D_
_x000D_

How to filter JSON Data in JavaScript or jQuery?

No need for jQuery unless you target old browsers and don't want to use shims.

var yahooOnly = JSON.parse(jsondata).filter(function (entry) {
    return entry.website === 'yahoo';
});

In ES2015:

const yahooOnly = JSON.parse(jsondata).filter(({website}) => website === 'yahoo');

Difference between OData and REST web services

REST stands for REpresentational State Transfer which is a resource based architectural style. Resource based means that data and functionalities are considered as resources.

OData is a web based protocol that defines a set of best practices for building and consuming RESTful web services. OData is a way to create RESTful web services thus an implementation of REST.

How to update/refresh specific item in RecyclerView

you just have to add following code in alert dialog box on save click

          recyclerData.add(position, updateText.getText().toString());
          recyclerAdapter.notifyItemChanged(position);

jquery save json data object in cookie

Now there is already no need to use JSON.stringify explicitly. Just execute this line of code

$.cookie.json = true;

After that you can save any object in cookie, which will be automatically converted to JSON and back from JSON when reading cookie.

var user = { name: "name", age: 25 }
$.cookie('user', user);
...

var currentUser = $.cookie('user');
alert('User name is ' + currentUser.name);

But JSON library does not come with jquery.cookie, so you have to download it by yourself and include into html page before jquery.cookie.js

How can I make a list of lists in R?

Using your example::

list1 <- list()
list1[1] = 1
list1[2] = 2
list2 <- list()
list2[1] = 'a'
list2[2] = 'b'
list_all <- list(list1, list2)

Use '[[' to retrieve an element of a list:

b = list_all[[1]]
 b
[[1]]
[1] 1

[[2]]
[1] 2

class(b)
[1] "list"

TypeError: window.initMap is not a function

In my case there was a formatting issue earlier on, so the error was a consequence of something else. My server was rendering the lat/lon values with commas instead of periods, because of different regional settings.

Cannot set property 'innerHTML' of null

Let us first try to understand the root cause as to why it is happening in first place.

Why do I get an error or Uncaught TypeError: Cannot set property 'innerHTML' of null?

The browser always loads the entire HTML DOM from top to bottom. Any JavaScript code written inside the script tags (present in head section of your HTML file) gets executed by the browser rendering engine even before your whole DOM (various HTML element tags present within body tag) is loaded. The scripts present in head tag are trying to access an element having id hello even before it has actually been rendered in the DOM. So obviously, JavaScript failed to see the element and hence you end up seeing the null reference error.

How can you make it work as before?

You want to show the "hi" message on the page as soon as the user lands on your page for the first time. So you need to hook up your code at a point when you are completely sure of the fact that DOM is fully loaded and the hello id element is accessible/available. It is achievable in two ways:

  1. Reorder your scripts: This way your scripts get fired only after the DOM containing your hello id element is already loaded. You can achieve it by simply moving the script tag after all the DOM elements i.e. at the bottom where body tag is ending. Since rendering happens from top to bottom so your scripts get executed in the end and you face no error.

_x000D_
_x000D_
    <!DOCTYPE HTML>_x000D_
    <html>_x000D_
    <head>_x000D_
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">_x000D_
    <title>Untitled Document</title>_x000D_
    </head>_x000D_
    _x000D_
    <body>_x000D_
    <div id="hello"></div>_x000D_
    _x000D_
    <script type ="text/javascript">_x000D_
        what();_x000D_
        function what(){_x000D_
            document.getElementById('hello').innerHTML = 'hi';_x000D_
        };_x000D_
    </script>_x000D_
    </body>_x000D_
    </html>
_x000D_
_x000D_
_x000D_

  1. Use event hooking: Browser's rendering engine provides an event based hook through window.onload event which gives you the hint that browser has finished loading the DOM. So by the time when this event gets fired, you can be rest assured that your element with hello id already loaded in the DOM and any JavaScript fired thereafter which tries to access this element will not fail. So you do something like below code snippet. Please note that in this case, your script works even though it is present at the top of your HTML document inside the head tag.

_x000D_
_x000D_
<!DOCTYPE HTML>_x000D_
        <html>_x000D_
        <head>_x000D_
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">_x000D_
        <title>Untitled Document</title>_x000D_
        <script type ="text/javascript">_x000D_
            window.onload = function() {_x000D_
            what();_x000D_
            function what(){_x000D_
                document.getElementById('hello').innerHTML = 'hi';_x000D_
            };_x000D_
        }_x000D_
        </script>_x000D_
        </head>_x000D_
        _x000D_
        <body>_x000D_
        <div id="hello"></div>_x000D_
        </body>_x000D_
        </html>
_x000D_
_x000D_
_x000D_

How to get english language word database?

I do not see http://wordlist.sourceforge.net/ mentioned here, but that is where I would start if I were looking for something like this (and I was, when I stumbled over this question).

If you cannot find what you want there, and what you want is a list of english words, then you should probably spend some extra time describing how to recognize what it is that you want.

Group by in LINQ

An alternative way to do this could be select distinct PersonId and group join with persons:

var result = 
    from id in persons.Select(x => x.PersonId).Distinct()
    join p2 in persons on id equals p2.PersonId into gr // apply group join here
    select new 
    {
        PersonId = id,
        Cars = gr.Select(x => x.Car).ToList(),
    };

Or the same with fluent API syntax:

var result = persons.Select(x => x.PersonId).Distinct()
    .GroupJoin(persons, id => id, p => p.PersonId, (id, gr) => new
    {
        PersonId = id,
        Cars = gr.Select(x => x.Car).ToList(),
    });

GroupJoin produces a list of entries in the first list ( list of PersonId in our case), each with a group of joined entries in the second list (list of persons).

Does C# have an equivalent to JavaScript's encodeURIComponent()?

You can use the Server object in the System.Web namespace

Server.UrlEncode, Server.UrlDecode, Server.HtmlEncode, and Server.HtmlDecode.

Edit: poster added that this was a windows application and not a web one as one would believe. The items listed above would be available from the HttpUtility class inside System.Web which must be added as a reference to the project.

How to add new column to an dataframe (to the front not end)?

df <- data.frame(b = c(1, 1, 1), c = c(2, 2, 2), d = c(3, 3, 3))
df
##   b c d
## 1 1 2 3
## 2 1 2 3
## 3 1 2 3

df <- data.frame(a = c(0, 0, 0), df)
df
##   a b c d
## 1 0 1 2 3
## 2 0 1 2 3
## 3 0 1 2 3

Trying to include a library, but keep getting 'undefined reference to' messages

The trick here is to put the library AFTER the module you are compiling. The problem is a reference thing. The linker resolves references in order, so when the library is BEFORE the module being compiled, the linker gets confused and does not think that any of the functions in the library are needed. By putting the library AFTER the module, the references to the library in the module are resolved by the linker.

Parse DateTime string in JavaScript

Use Date object:

var time = Date.parse('02.02.1999');
document.writeln(time);

Give: 917902800000

Double decimal formatting in Java

One of the way would be using NumberFormat.

NumberFormat formatter = new DecimalFormat("#0.00");     
System.out.println(formatter.format(4.0));

Output:

4.00

Install a .NET windows service without InstallUtil.exe

In the case of trying to install a command line application as a Windows service try the 'NSSM' utility. Related ServerFault details found here.

MySQL - How to increase varchar size of an existing column in a database without breaking existing data?

I'd like explain the different alter table syntaxes - See the MySQL documentation

For adding/removing defaults on a column:

ALTER TABLE table_name
ALTER COLUMN col_name {SET DEFAULT literal | DROP DEFAULT}

For renaming a column, changing it's data type and optionally changing the column order:

ALTER TABLE table_name
CHANGE [COLUMN] old_col_name new_col_name column_definition
[FIRST|AFTER col_name]

For changing a column's data type and optionally changing the column order:

ALTER TABLE table_name
MODIFY [COLUMN] col_name column_definition
[FIRST | AFTER col_name]

Set left margin for a paragraph in html

<p style="margin-left:5em;">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut lacinia vestibulum quam sit amet aliquet. Phasellus tempor nisi eget tellus venenatis tempus. Aliquam dapibus porttitor convallis. Praesent pretium luctus orci, quis ullamcorper lacus lacinia a. Integer eget molestie purus. Vestibulum porta mollis tempus. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. </p>

That'll do it, there's a few improvements obviously, but that's the basics. And I use 'em' as the measurement, you may want to use other units, like 'px'.

EDIT: What they're describing above is a way of associating groups of styles, or classes, with elements on a web page. You can implement that in a few ways, here's one which may suit you:

In your HTML page, containing the <p> tagged content from your DB add in a new 'style' node and wrap the styles you want to declare in a class like so:

<head>
  <style type="text/css">
    p { margin-left:5em; /* Or another measurement unit, like px */ }
  </style>
</head>
<body>
  <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut lacinia vestibulum quam sit amet aliquet.</p>
</body>

So above, all <p> elements in your document will have that style rule applied. Perhaps you are pumping your paragraph content into a container of some sort? Try this:

<head>
  <style type="text/css">
    .container p { margin-left:5em; /* Or another measurement unit, like px */ }
  </style>
</head>
<body>
  <div class="container">
    <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut lacinia vestibulum quam sit amet aliquet.</p>
  </div>
  <p>Vestibulum porta mollis tempus. Class aptent taciti sociosqu ad litora torquent per conubia nostra.</p>
</body>

In the example above, only the <p> element inside the div, whose class name is 'container', will have the styles applied - and not the <p> element outside the container.

In addition to the above, you can collect your styles together and remove the style element from the <head> tag, replacing it with a <link> tag, which points to an external CSS file. This external file is where you'd now put your <p> tag styles. This concept is known as 'seperating content from style' and is considered good practice, and is also an extendible way to create styles, and can help with low maintenance.

ImportError: No module named 'Queue'

Queue is in the multiprocessing module so:

from multiprocessing import Queue

Get total number of items on Json object?

In addition to kieran's answer, apparently, modern browsers have an Object.keys function. In this case, you could do this:

Object.keys(jsonArray).length;

More details in this answer on How to list the properties of a javascript object

UTF-8 encoding in JSP page

I had the same problem using special characters as delimiters on JSP. When the special characters got posted to the servlet, they all got messed up. I solved the issue by using the following conversion:

String str = new String (request.getParameter("string").getBytes ("iso-8859-1"), "UTF-8");

Creating a new column based on if-elif-else condition

For this particular relationship, you could use np.sign:

>>> df["C"] = np.sign(df.A - df.B)
>>> df
   A  B  C
a  2  2  0
b  3  1  1
c  1  3 -1

How to emulate a do-while loop in Python?

Python 3.8 has the answer.

It's called assignment expressions. from the documentation:

# Loop over fixed length blocks
while (block := f.read(256)) != '':
    process(block)

Change background color of R plot

I use abline() with extremely wide vertical lines to fill the plot space:

abline(v = xpoints, col = "grey90", lwd = 80)

You have to create the frame, then the ablines, and then plot the points so they are visible on top. You can even use a second abline() statement to put thin white or black lines over the grey, if desired.

Example:

xpoints = 1:20
y = rnorm(20)
plot(NULL,ylim=c(-3,3),xlim=xpoints)
abline(v=xpoints,col="gray90",lwd=80)
abline(v=xpoints,col="white")
abline(h = 0, lty = 2) 
points(xpoints, y, pch = 16, cex = 1.2, col = "red")

Simple PHP calculator

You also need to put the [== 'add'] math operation into quotes

if($_POST['group1'] == 'add') {
echo $first + $second;
}

complete code schould look like that :

<?php
$first = $_POST['first'];
$second= $_POST['second'];
if($_POST['group1'] == 'add') {
echo $first + $second;
}
else if($_POST['group1'] == 'subtract') {
echo $first - $second;
}
else if($_POST['group1'] == 'times') {
echo $first * $second;
} 
else if($_POST['group1'] == 'divide') {
echo $first / $second;
}
?>

How to Set the Background Color of a JButton on the Mac OS

If you are not required to use Apple's look and feel, a simple fix is to put the following code in your application or applet, before you add any GUI components to your JFrame or JApplet:

 try {
    UIManager.setLookAndFeel( UIManager.getCrossPlatformLookAndFeelClassName() );
 } catch (Exception e) {
            e.printStackTrace();
 }

That will set the look and feel to the cross-platform look and feel, and the setBackground() method will then work to change a JButton's background color.

jQuery's jquery-1.10.2.min.map is triggering a 404 (Not Found)

If Chrome DevTools is reporting a 404 for a .map file (maybe jquery-1.10.2.min.map, jquery.min.map or jquery-2.0.3.min.map, but can happen with anything) first thing to know is this is only requested when using the DevTools. Your users will not be hitting this 404.

Now you can fix this or disable the sourcemap functionality.

Fix: get the files

Next, it's an easy fix. Head to http://jquery.com/download/ and click the Download the map file link for your version, and you'll want the uncompressed file downloaded as well.

enter image description here

Having the map file in place allows you do debug your minified jQuery via the original sources, which will save a lot of time and frustration if you don't like dealing with variable names like a and c.

More about sourcemaps here: An Introduction to JavaScript Source Maps

Dodge: disable sourcemaps

Instead of getting the files, you can alternatively disable JavaScript source maps completely for now, in your settings. This is a fine choice if you never plan on debugging JavaScript on this page. Use the cog icon in the bottom right of the DevTools, to open settings, then: enter image description here

Adding an image to a PDF using iTextSharp and scale it properly

You can try something like this:

      Image logo = Image.GetInstance("pathToTheImage")
      logo.ScaleAbsolute(500, 300)

Run a command over SSH with JSch

Usage:

String remoteCommandOutput = exec("ssh://user:pass@host/work/dir/path", "ls -t | head -n1");
String remoteShellOutput = shell("ssh://user:pass@host/work/dir/path", "ls");
shell("ssh://user:pass@host/work/dir/path", "ls", System.out);
shell("ssh://user:pass@host", System.in, System.out);
sftp("file:/C:/home/file.txt", "ssh://user:pass@host/home");
sftp("ssh://user:pass@host/home/file.txt", "file:/C:/home");

Implementation:

import static com.google.common.base.Preconditions.checkState;
import static java.lang.Thread.sleep;
import static org.apache.commons.io.FilenameUtils.getFullPath;
import static org.apache.commons.io.FilenameUtils.getName;
import static org.apache.commons.lang3.StringUtils.trim;

import com.google.common.collect.ImmutableMap;
import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.ChannelShell;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.Session;
import com.jcraft.jsch.UIKeyboardInteractive;
import com.jcraft.jsch.UserInfo;
import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import java.io.PrintWriter;
import java.net.URI;
import java.util.Map;
import java.util.Properties;

public final class SshUtils {

    private static final Logger LOG = LoggerFactory.getLogger(SshUtils.class);
    private static final String SSH = "ssh";
    private static final String FILE = "file";

    private SshUtils() {
    }

    /**
     * <pre>
     * <code>
     * sftp("file:/C:/home/file.txt", "ssh://user:pass@host/home");
     * sftp("ssh://user:pass@host/home/file.txt", "file:/C:/home");
     * </code>
     *
     * <pre>
     *
     * @param fromUri
     *            file
     * @param toUri
     *            directory
     */
    public static void sftp(String fromUri, String toUri) {
        URI from = URI.create(fromUri);
        URI to = URI.create(toUri);

        if (SSH.equals(to.getScheme()) && FILE.equals(from.getScheme()))
            upload(from, to);
        else if (SSH.equals(from.getScheme()) && FILE.equals(to.getScheme()))
            download(from, to);
        else
            throw new IllegalArgumentException();
    }

    private static void upload(URI from, URI to) {
        try (SessionHolder<ChannelSftp> session = new SessionHolder<>("sftp", to);
                FileInputStream fis = new FileInputStream(new File(from))) {

            LOG.info("Uploading {} --> {}", from, session.getMaskedUri());
            ChannelSftp channel = session.getChannel();
            channel.connect();
            channel.cd(to.getPath());
            channel.put(fis, getName(from.getPath()));

        } catch (Exception e) {
            throw new RuntimeException("Cannot upload file", e);
        }
    }

    private static void download(URI from, URI to) {
        File out = new File(new File(to), getName(from.getPath()));
        try (SessionHolder<ChannelSftp> session = new SessionHolder<>("sftp", from);
                OutputStream os = new FileOutputStream(out);
                BufferedOutputStream bos = new BufferedOutputStream(os)) {

            LOG.info("Downloading {} --> {}", session.getMaskedUri(), to);
            ChannelSftp channel = session.getChannel();
            channel.connect();
            channel.cd(getFullPath(from.getPath()));
            channel.get(getName(from.getPath()), bos);

        } catch (Exception e) {
            throw new RuntimeException("Cannot download file", e);
        }
    }

    /**
     * <pre>
     * <code>
     * shell("ssh://user:pass@host", System.in, System.out);
     * </code>
     * </pre>
     */
    public static void shell(String connectUri, InputStream is, OutputStream os) {
        try (SessionHolder<ChannelShell> session = new SessionHolder<>("shell", URI.create(connectUri))) {
            shell(session, is, os);
        }
    }

    /**
     * <pre>
     * <code>
     * String remoteOutput = shell("ssh://user:pass@host/work/dir/path", "ls")
     * </code>
     * </pre>
     */
    public static String shell(String connectUri, String command) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try {
            shell(connectUri, command, baos);
            return baos.toString();
        } catch (RuntimeException e) {
            LOG.warn(baos.toString());
            throw e;
        }
    }

    /**
     * <pre>
     * <code>
     * shell("ssh://user:pass@host/work/dir/path", "ls", System.out)
     * </code>
     * </pre>
     */
    public static void shell(String connectUri, String script, OutputStream out) {
        try (SessionHolder<ChannelShell> session = new SessionHolder<>("shell", URI.create(connectUri));
                PipedOutputStream pipe = new PipedOutputStream();
                PipedInputStream in = new PipedInputStream(pipe);
                PrintWriter pw = new PrintWriter(pipe)) {

            if (session.getWorkDir() != null)
                pw.println("cd " + session.getWorkDir());
            pw.println(script);
            pw.println("exit");
            pw.flush();

            shell(session, in, out);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    private static void shell(SessionHolder<ChannelShell> session, InputStream is, OutputStream os) {
        try {
            ChannelShell channel = session.getChannel();
            channel.setInputStream(is, true);
            channel.setOutputStream(os, true);

            LOG.info("Starting shell for " + session.getMaskedUri());
            session.execute();
            session.assertExitStatus("Check shell output for error details.");
        } catch (InterruptedException | JSchException e) {
            throw new RuntimeException("Cannot execute script", e);
        }
    }

    /**
     * <pre>
     * <code>
     * System.out.println(exec("ssh://user:pass@host/work/dir/path", "ls -t | head -n1"));
     * </code>
     * 
     * <pre>
     * 
     * @param connectUri
     * @param command
     * @return
     */
    public static String exec(String connectUri, String command) {
        try (SessionHolder<ChannelExec> session = new SessionHolder<>("exec", URI.create(connectUri))) {
            String scriptToExecute = session.getWorkDir() == null
                    ? command
                    : "cd " + session.getWorkDir() + "\n" + command;
            return exec(session, scriptToExecute);
        }
    }

    private static String exec(SessionHolder<ChannelExec> session, String command) {
        try (PipedOutputStream errPipe = new PipedOutputStream();
                PipedInputStream errIs = new PipedInputStream(errPipe);
                InputStream is = session.getChannel().getInputStream()) {

            ChannelExec channel = session.getChannel();
            channel.setInputStream(null);
            channel.setErrStream(errPipe);
            channel.setCommand(command);

            LOG.info("Starting exec for " + session.getMaskedUri());
            session.execute();
            String output = IOUtils.toString(is);
            session.assertExitStatus(IOUtils.toString(errIs));

            return trim(output);
        } catch (InterruptedException | JSchException | IOException e) {
            throw new RuntimeException("Cannot execute command", e);
        }
    }

    public static class SessionHolder<C extends Channel> implements Closeable {

        private static final int DEFAULT_CONNECT_TIMEOUT = 5000;
        private static final int DEFAULT_PORT = 22;
        private static final int TERMINAL_HEIGHT = 1000;
        private static final int TERMINAL_WIDTH = 1000;
        private static final int TERMINAL_WIDTH_IN_PIXELS = 1000;
        private static final int TERMINAL_HEIGHT_IN_PIXELS = 1000;
        private static final int DEFAULT_WAIT_TIMEOUT = 100;

        private String channelType;
        private URI uri;
        private Session session;
        private C channel;

        public SessionHolder(String channelType, URI uri) {
            this(channelType, uri, ImmutableMap.of("StrictHostKeyChecking", "no"));
        }

        public SessionHolder(String channelType, URI uri, Map<String, String> props) {
            this.channelType = channelType;
            this.uri = uri;
            this.session = newSession(props);
            this.channel = newChannel(session);
        }

        private Session newSession(Map<String, String> props) {
            try {
                Properties config = new Properties();
                config.putAll(props);

                JSch jsch = new JSch();
                Session newSession = jsch.getSession(getUser(), uri.getHost(), getPort());
                newSession.setPassword(getPass());
                newSession.setUserInfo(new User(getUser(), getPass()));
                newSession.setDaemonThread(true);
                newSession.setConfig(config);
                newSession.connect(DEFAULT_CONNECT_TIMEOUT);
                return newSession;
            } catch (JSchException e) {
                throw new RuntimeException("Cannot create session for " + getMaskedUri(), e);
            }
        }

        @SuppressWarnings("unchecked")
        private C newChannel(Session session) {
            try {
                Channel newChannel = session.openChannel(channelType);
                if (newChannel instanceof ChannelShell) {
                    ChannelShell channelShell = (ChannelShell) newChannel;
                    channelShell.setPtyType("ANSI", TERMINAL_WIDTH, TERMINAL_HEIGHT, TERMINAL_WIDTH_IN_PIXELS, TERMINAL_HEIGHT_IN_PIXELS);
                }
                return (C) newChannel;
            } catch (JSchException e) {
                throw new RuntimeException("Cannot create " + channelType + " channel for " + getMaskedUri(), e);
            }
        }

        public void assertExitStatus(String failMessage) {
            checkState(channel.getExitStatus() == 0, "Exit status %s for %s\n%s", channel.getExitStatus(), getMaskedUri(), failMessage);
        }

        public void execute() throws JSchException, InterruptedException {
            channel.connect();
            channel.start();
            while (!channel.isEOF())
                sleep(DEFAULT_WAIT_TIMEOUT);
        }

        public Session getSession() {
            return session;
        }

        public C getChannel() {
            return channel;
        }

        @Override
        public void close() {
            if (channel != null)
                channel.disconnect();
            if (session != null)
                session.disconnect();
        }

        public String getMaskedUri() {
            return uri.toString().replaceFirst(":[^:]*?@", "@");
        }

        public int getPort() {
            return uri.getPort() < 0 ? DEFAULT_PORT : uri.getPort();
        }

        public String getUser() {
            return uri.getUserInfo().split(":")[0];
        }

        public String getPass() {
            return uri.getUserInfo().split(":")[1];
        }

        public String getWorkDir() {
            return uri.getPath();
        }
    }

    private static class User implements UserInfo, UIKeyboardInteractive {

        private String user;
        private String pass;

        public User(String user, String pass) {
            this.user = user;
            this.pass = pass;
        }

        @Override
        public String getPassword() {
            return pass;
        }

        @Override
        public boolean promptYesNo(String str) {
            return false;
        }

        @Override
        public String getPassphrase() {
            return user;
        }

        @Override
        public boolean promptPassphrase(String message) {
            return true;
        }

        @Override
        public boolean promptPassword(String message) {
            return true;
        }

        @Override
        public void showMessage(String message) {
            // do nothing
        }

        @Override
        public String[] promptKeyboardInteractive(String destination, String name, String instruction, String[] prompt, boolean[] echo) {
            return null;
        }
    }
}

'dict' object has no attribute 'has_key'

has_key has been deprecated in Python 3.0. Alternatively you can use 'in'

graph={'A':['B','C'],
   'B':['C','D']}

print('A' in graph)
>> True

print('E' in graph)
>> False

Efficient way to remove keys with empty strings from a dict

Here is an option if you are using pandas:

import pandas as pd

d = dict.fromkeys(['a', 'b', 'c', 'd'])
d['b'] = 'not null'
d['c'] = ''  # empty string

print(d)

# convert `dict` to `Series` and replace any blank strings with `None`;
# use the `.dropna()` method and
# then convert back to a `dict`
d_ = pd.Series(d).replace('', None).dropna().to_dict()

print(d_)

Remove file extension from a file name string

    /// <summary>
    /// Get the extension from the given filename
    /// </summary>
    /// <param name="fileName">the given filename ie:abc.123.txt</param>
    /// <returns>the extension ie:txt</returns>
    public static string GetFileExtension(this string fileName)
    {
        string ext = string.Empty;
        int fileExtPos = fileName.LastIndexOf(".", StringComparison.Ordinal);
        if (fileExtPos >= 0)
            ext = fileName.Substring(fileExtPos, fileName.Length - fileExtPos);

        return ext;
    }

What's the difference between subprocess Popen and call (how can I use them)?

There are two ways to do the redirect. Both apply to either subprocess.Popen or subprocess.call.

  1. Set the keyword argument shell = True or executable = /path/to/the/shell and specify the command just as you have it there.

  2. Since you're just redirecting the output to a file, set the keyword argument

    stdout = an_open_writeable_file_object
    

    where the object points to the output file.

subprocess.Popen is more general than subprocess.call.

Popen doesn't block, allowing you to interact with the process while it's running, or continue with other things in your Python program. The call to Popen returns a Popen object.

call does block. While it supports all the same arguments as the Popen constructor, so you can still set the process' output, environmental variables, etc., your script waits for the program to complete, and call returns a code representing the process' exit status.

returncode = call(*args, **kwargs) 

is basically the same as calling

returncode = Popen(*args, **kwargs).wait()

call is just a convenience function. It's implementation in CPython is in subprocess.py:

def call(*popenargs, timeout=None, **kwargs):
    """Run command with arguments.  Wait for command to complete or
    timeout, then return the returncode attribute.

    The arguments are the same as for the Popen constructor.  Example:

    retcode = call(["ls", "-l"])
    """
    with Popen(*popenargs, **kwargs) as p:
        try:
            return p.wait(timeout=timeout)
        except:
            p.kill()
            p.wait()
            raise

As you can see, it's a thin wrapper around Popen.

How to get all privileges back to the root user in MySQL?

Log in as root, then run the following MySQL commands:

GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost';
FLUSH PRIVILEGES;

A connection was successfully established with the server, but then an error occurred during the login process. (Error Number: 233)

From here:

Root Cause: Maximum connection has been exceeded on your SQL Server Instance.

How to fix it...!

  1. F8 or Object Explorer
  2. Right click on Instance --> Click Properties...
  3. Select "Connections" on "Select a page" area at left
  4. Chenge the value to 0 (Zero) for "Maximum number of concurrent connections(0 = Unlimited)"
  5. Restart the SQL Server Instance once.

Apart from that also ensure that below are enabled:

  • Shared Memory protocol is enabled
  • Named Pipes protocol is enabled
  • TCP/IP is enabled

Filename too long in Git for Windows

In a windows Machine

Run Command Prompt as administrator then run below command

git config --system core.longpaths true

ClientScript.RegisterClientScriptBlock?

The method System.Web.UI.Page.RegisterClientScriptBlock has been deprecated for some time (along with the other Page.Register* methods), ever since .NET 2.0 as shown by MSDN.

Instead use the .NET 2.0 Page.ClientScript.Register* methods. - (The ClientScript property expresses an instance of the ClientScriptManager class )

Guessing the problem

If you are saying your JavaScript alert box occurs before the page's content is visibly rendered, and therefore the page remains white (or still unrendered) when the alert box is dismissed by the user, then try using the Page.ClientScript.RegisterStartupScript(..) method instead because it runs the given client-side code when the page finishes loading - and its arguments are similar to what you're using already.

Also check for general JavaScript errors in the page - this is often seen by an error icon in the browser's status bar. Sometimes a JavaScript error will hold up or disturb unrelated elements on the page.

document.getElementById(id).focus() is not working for firefox or chrome

I suspect the reason this works is the browser rendering runs on the same thread as javascript, and setTimeout(function(){},0); queues the javascript function inside setTimeout to execute when the browser becomes idle. If anyone has a more in-depth explanation please share it.

setTimeout(function(){ 
 if(document.getElementById('mobileno')){
  document.getElementById('mobileno').focus();
 } 
},0);

Input type=password, don't let browser remember the password

<input type="password" autocomplete="off" />

I'd just like to add that as a user I think this is very annoying and a hassle to overcome. I strongly recommend against using this as it will more than likely aggravate your users.

Passwords are already not stored in the MRU, and correctly configured public machines will not even save the username.

How can I get around MySQL Errcode 13 with SELECT INTO OUTFILE?

In my case, the solution was to make every directory in the directory path readable and accessible by mysql (chmod a+rx). The directory was still specified by its relative path in the command line.

chmod a+rx /tmp
chmod a+rx /tmp/migration
etc.

Rails: Adding an index after adding column

Add in the generated migration after creating the column the following (example)

add_index :photographers, :email, :unique => true

How do I remove a submodule?

I just found the .submodule (forgot exact name) hidden file, it has a list... you can erase them individually that way. I just had one, so I deleted it. Simple, but it might mess up Git, since I don't know if anything's attached to the submodule. Seems ok so far, aside from libetpan's usual upgrade issue, but that's (hopefully) unrelated.

Noticed nobody posted manual erasing, so added

How do I find the location of my Python site-packages directory?

Answer to old question. But use ipython for this.

pip install ipython
ipython 
import imaplib
imaplib?

This will give the following output about imaplib package -

Type:        module
String form: <module 'imaplib' from '/usr/lib/python2.7/imaplib.py'>
File:        /usr/lib/python2.7/imaplib.py
Docstring:  
IMAP4 client.

Based on RFC 2060.

Public class:           IMAP4
Public variable:        Debug
Public functions:       Internaldate2tuple
                        Int2AP
                        ParseFlags
                        Time2Internaldate

Purpose of #!/usr/bin/python3 shebang

This line helps find the program executable that will run the script. This shebang notation is fairly standard across most scripting languages (at least as used on grown-up operating systems).

An important aspect of this line is specifying which interpreter will be used. On many development-centered Linux distributions, for example, it is normal to have several versions of python installed at the same time.

Python 2.x and Python 3 are not 100% compatible, so this difference can be very important. So #! /usr/bin/python and #! /usr/bin/python3 are not the same (and neither are quite the same as #! /usr/bin/env python3 as noted elsewhere on this page.

How to add a where clause in a MySQL Insert statement?

I think you are looking for UPDATE and not insert?

UPDATE `users`
SET `username` = 'Jack', `password` = '123'
WHERE `id` = 1

EC2 instance has no public DNS

I had the same problem an solved it. Have a look at the step-by-step instructions:

  • Go to console.aws.amazon.com
  • Go To Services -> VPC
  • Open Your VPCs
  • select your VPC connected to your EC2 and
  • select Actions => Edit DNS Hostnames ---> Change DNS hostnames: to YES

Hope this helps!

Cheers

Error: [$resource:badcfg] Error in resource configuration. Expected response to contain an array but got an object?

First of all you should configure $resource in different manner: without query params in the URL. Default query parameters may be passed as properties of the second parameter in resource(url, paramDefaults, actions). It is also to be mentioned that you configure get method of resource and using query instead.

Service

angular.module('admin.services', ['ngResource'])       
  // GET TASK LIST ACTIVITY
  .factory('getTaskService', function($resource) {
    return $resource(
      '../rest/api.php',
      { method: 'getTask', q: '*' }, // Query parameters
      {'query': { method: 'GET' }}
    );
  })

Documentation

http://docs.angularjs.org/api/ngResource.$resource

how to remove pagination in datatable

Here is an alternative that is an incremental improvement on several other answers. Assuming settings.aLengthMenu is not multi-dimensional (it can be when DataTables has row lengths and labels) and the data will not change after page load (for simple DOM-loaded DataTables), this function can be inserted to eliminate paging. It hides several paging-related classes.

Perhaps more robust would be setting paging to false inside the function below, however I don't see an API call for that off-hand.

$('#myTable').on('init.dt', function(evt, settings) {
    if (settings && settings.aLengthMenu && settings.fnRecordsTotal && settings.fnRecordsTotal() < settings.aLengthMenu[0]) {
        // hide pagination controls, fewer records than minimum length
        $(settings.nTableWrapper).find('.dataTables_paginate, .dataTables_length, .dataTables_info').hide();
    }
}).DataTable();

SSH -L connection successful, but localhost port forwarding not working "channel 3: open failed: connect failed: Connection refused"

Just replace localhost with 127.0.0.1.

(The answer is based on answers of other people on this page.)

How to update Python?

I have always just installed the new version on top and never had any issues. Do make sure that your path is updated to point to the new version though.

Naming threads and thread-pools of ExecutorService

The home-grown core Java solution that I use to decorate existing factories:

public class ThreadFactoryNameDecorator implements ThreadFactory {
    private final ThreadFactory defaultThreadFactory;
    private final String suffix;

    public ThreadFactoryNameDecorator(String suffix) {
        this(Executors.defaultThreadFactory(), suffix);
    }

    public ThreadFactoryNameDecorator(ThreadFactory threadFactory, String suffix) {
        this.defaultThreadFactory = threadFactory;
        this.suffix = suffix;
    }

    @Override
    public Thread newThread(Runnable task) {
        Thread thread = defaultThreadFactory.newThread(task);
        thread.setName(thread.getName() + "-" + suffix);
        return thread;
    }
}

In action:

Executors.newSingleThreadExecutor(new ThreadFactoryNameDecorator("foo"));

AngularJS sorting by property

according to http://docs.angularjs.org/api/ng.filter:orderBy , orderBy sorts an array. In your case you're passing an object, so You'll have to implement Your own sorting function.

or pass an array -

$scope.testData = {
    C: {name:"CData", order: 1},
    B: {name:"BData", order: 2},
    A: {name:"AData", order: 3},
}

take a look at http://jsfiddle.net/qaK56/

How to check if a value exists in an object using JavaScript

var obj = {"a": "test1", "b": "test2"};
var getValuesOfObject = Object.values(obj)
for(index = 0; index < getValuesOfObject.length; index++){
    return Boolean(getValuesOfObject[index] === "test1")
}

The Object.values() method returned an array (assigned to getValuesOfObject) containing the given object's (obj) own enumerable property values. The array was iterated using the for loop to retrieve each value (values in the getValuesfromObject) and returns a Boolean() function to find out if the expression ("text1" is a value in the looping array) is true.

How to change the default browser to debug with in Visual Studio 2008?

  • (In the Project Solution window) Right click a page (.aspx, or on a folder)
  • Select Browse With...
  • Choose your browser
  • Click Set as Default
  • Click Browse

context menu screenshot

versionCode vs versionName in Android Manifest

versionCode

A positive integer used as an internal version number. This number is used only to determine whether one version is more recent than another, with higher numbers indicating more recent versions. This is not the version number shown to users; that number is set by the versionName setting, below. The Android system uses the versionCode value to protect against downgrades by preventing users from installing an APK with a lower versionCode than the version currently installed on their device.

The value is a positive integer so that other apps can programmatically evaluate it, for example to check an upgrade or downgrade relationship. You can set the value to any positive integer you want, however you should make sure that each successive release of your app uses a greater value. You cannot upload an APK to the Play Store with a versionCode you have already used for a previous version.

versionName

A string used as the version number shown to users. This setting can be specified as a raw string or as a reference to a string resource.

The value is a string so that you can describe the app version as a .. string, or as any other type of absolute or relative version identifier. The versionName has no purpose other than to be displayed to users.

Combine two tables for one output

In your expected output, you've got the second last row sum incorrect, it should be 40 according to the data in your tables, but here is the query:

Select  ChargeNum, CategoryId, Sum(Hours)
From    (
    Select  ChargeNum, CategoryId, Hours
    From    KnownHours
    Union
    Select  ChargeNum, 'Unknown' As CategoryId, Hours
    From    UnknownHours
) As a
Group By ChargeNum, CategoryId
Order By ChargeNum, CategoryId

And here is the output:

ChargeNum  CategoryId 
---------- ---------- ----------------------
111111     1          40
111111     2          50
111111     Unknown    70
222222     1          40
222222     Unknown    25.5

Trying to SSH into an Amazon Ec2 instance - permission error

The problem is having wrong mod on the file.

Easily solved by executing -

chmod 400 mykey.pem

Taken from Amazon's instructions -

Your key file must not be publicly viewable for SSH to work. Use this command if needed: chmod 400 mykey.pem

400 protects it by making it read only and only for the owner.

How to select ALL children (in any level) from a parent in jQuery?

Use jQuery.find() to find children more than one level deep.

The .find() and .children() methods are similar, except that the latter only travels a single level down the DOM tree.

$('#google_translate_element').find('*').unbind('click');

You need the '*' in find():

Unlike in the rest of the tree traversal methods, the selector expression is required in a call to .find(). If we need to retrieve all of the descendant elements, we can pass in the universal selector '*' to accomplish this.

Importing Pandas gives error AttributeError: module 'pandas' has no attribute 'core' in iPython Notebook

I face similar issue while importing TensorFlow. If you are using Tensorflow which uses Pandas library, I suggest restarting your kernel of Anaconda. This works for me.

jQuery datepicker set selected date, on the fly

This works for me:

$("#dateselector").datepicker("option", "defaultDate", new Date(2008,9,3));

Android SDK is missing, out of date, or is missing templates. Please ensure you are using SDK version 22 or later

I had same issue in Android Studio 3. (the project was open) so I closed the current project and the IDE automatically prompted to download the latest components. once its done everything was working correctly.

The remote host closed the connection. The error code is 0x800704CD

One can reproduce the error with the code below:

public ActionResult ClosingTheConnectionAction(){
   try
   {
      //we need to set buffer to false to
      //make sure data is written in chunks
      Response.Buffer = false;  
      var someText = "Some text here to make things happen ;-)";
      var content = GetBytes( someText );

      for(var i=0; i < 100; i++)
      {
         Response.OutputStream.Write(content, 0, content.Length);
      }

      return View();
   }
   catch(HttpException hex)
   {
      if (hex.Message.StartsWith("The remote host closed the connection. The error code is 0x800704CD."))
            {
                //react on remote host closed the connection exception.
                var msg = hex.Message;
            }  
   }
   catch(Exception somethingElseHappened)
   {
      //handle it with some other code
   }

   return View();
} 

Now run the website in debug mode. Put a breakpoint in the loop that writes to the output stream. Go to that action method and after the first iteration passed close the tab of the browser. Hit F10 to continue the loop. After it hit the next iteration you will see the exception. Enjoy your exception :-)

spring autowiring with unique beans: Spring expected single matching bean but found 2

If you have 2 beans of the same class autowired to one class you shoud use @Qualifier (Spring Autowiring @Qualifier example).

But it seems like your problem comes from incorrect Java Syntax.

Your object should start with lower case letter

SuggestionService suggestion;

Your setter should start with lower case as well and object name should be with Upper case

public void setSuggestion(final Suggestion suggestion) {
    this.suggestion = suggestion;
}

Sort array by firstname (alphabetically) in Javascript

Nice little ES6 one liner:

users.sort((a, b) => a.firstname !== b.firstname ? a.firstname < b.firstname ? -1 : 1 : 0);

Visual Studio: ContextSwitchDeadlock

You can solve this by unchecking contextswitchdeadlock from

Debug->Exceptions ... -> Expand MDA node -> uncheck -> contextswitchdeadlock

UITableViewCell Selected Background Color on Multiple Selection

Swift 4.2

For multiple selections you need to set the UITableView property allowsMultipleSelection to true.

myTableView.allowsMultipleSelection = true

In case you subclassed the UITableViewCell, you override setSelected(_ selected: Bool, animated: Bool) method in your custom cell class.

 override func setSelected(_ selected: Bool, animated: Bool) {
     super.setSelected(selected, animated: animated)

     if selected {
         contentView.backgroundColor = UIColor.green
     } else {
         contentView.backgroundColor = UIColor.blue
     }
 }

Storing an object in state of a React component?

Even though it can be done via immutability-helper or similar I do not wan't to add external dependencies to my code unless I really have to. When I need to do it I use Object.assign. Code:

this.setState({ abc : Object.assign({}, this.state.abc , {xyz: 'new value'})})

Can be used on HTML Event Attributes as well, example:

onChange={e => this.setState({ abc : Object.assign({}, this.state.abc, {xyz : 'new value'})})}

How do I create and access the global variables in Groovy?

def iamnotglobal=100 // This will not be accessible inside the function

iamglobal=200 // this is global and will be even available inside the 

def func()
{
    log.info "My value is 200. Here you see " + iamglobal
    iamglobal=400
    //log.info "if you uncomment me you will get error. Since iamnotglobal cant be printed here " + iamnotglobal
}
def func2()
{
   log.info "My value was changed inside func to 400 . Here it is = " + iamglobal
}
func()
func2()

here iamglobal variable is a global variable used by func and then again available to func2

if you declare variable with def it will be local, if you don't use def its global

htaccess redirect if URL contains a certain string

RewriteCond %{REQUEST_URI} foobar
RewriteRule .* index.php

or some variant thereof.

How to fix the session_register() deprecated issue?

To complement Felix Kling's answer, I was studying a codebase that used to have the following code:

if (is_array($start_vars)) {
    foreach ($start_vars as $var) {
        session_register($var);
    }
} else if (!(empty($start_vars))) {
    session_register($start_vars);
}

In order to not use session_register they made the following adjustments:

if (is_array($start_vars)) {
    foreach ($start_vars as $var) {
        $_SESSION[$var] =  $GLOBALS[$var];
    }
} else if (!(empty($start_vars))) {
    $_SESSION[$start_vars] =  $GLOBALS[$start_vars];
}

Rounded corner for textview in android

Since your top level view already has android:background property set, you can use a <layer-list> (link) to create a new XML drawable that combines both your old background and your new rounded corners background.

Each <item> element in the list is drawn over the next, so the last item in the list is the one that ends up on top.

<?xml version="1.0" encoding="utf-8"?>
<layer-list
    xmlns:android="http://schemas.android.com/apk/res/android" >
    <item>
        <bitmap android:src="@drawable/mydialogbox" />
    </item>
    <item>
        <shape>
            <stroke
                android:width="1dp"
                android:color="@color/common_border_color" />

            <solid android:color="#ffffff" />

            <padding
                    android:left="1dp"
                    android:right="1dp"
                    android:top="1dp" />

            <corners android:radius="5dp" />
        </shape>
    </item>
</layer-list>

How do I use Ruby for shell scripting?

This might also be helpful: http://rush.heroku.com/

I haven't used it much, but looks pretty cool

From the site:

rush is a replacement for the unix shell (bash, zsh, etc) which uses pure Ruby syntax. Grep through files, find and kill processes, copy files - everything you do in the shell, now in Ruby