Programs & Examples On #Nsmenuitem

The NSMenuItem class from AppKit.framework in Mac OS, defines objects that are used as command items in menus.

FileNotFoundException..Classpath resource not found in spring?

Check the contents of SpringExample/target/classes. Is spring-config.xml there? If not, try manually removing the SpringExample/target/ directory, and force a rebuild with Project=>Clean... in Eclipse.

Exit a Script On Error

If you put set -e in a script, the script will terminate as soon as any command inside it fails (i.e. as soon as any command returns a nonzero status). This doesn't let you write your own message, but often the failing command's own messages are enough.

The advantage of this approach is that it's automatic: you don't run the risk of forgetting to deal with an error case.

Commands whose status is tested by a conditional (such as if, && or ||) do not terminate the script (otherwise the conditional would be pointless). An idiom for the occasional command whose failure doesn't matter is command-that-may-fail || true. You can also turn set -e off for a part of the script with set +e.

how to call a function from another function in Jquery

I assume you don't want to rebind the event, but call the handler.

You can use trigger() to trigger events:

$('#billing_state_id').trigger('change');

If your handler doesn't rely on the event context and you don't want to trigger other handlers for the event, you could also name the function:

function someFunction() {
    //do stuff
}

$(document).ready(function(){
    //Load City by State
    $('#billing_state_id').live('change', someFunction);   
    $('#click_me').live('click', function() {
       //do something
       someFunction();
    });
  });

Also note that live() is deprecated, on() is the new hotness.

How to uncommit my last commit in Git

If you haven't pushed your changes yet use git reset --soft [Hash for one commit] to rollback to a specific commit. --soft tells git to keep the changes being rolled back (i.e., mark the files as modified). --hard tells git to delete the changes being rolled back.

How to increase storage for Android Emulator? (INSTALL_FAILED_INSUFFICIENT_STORAGE)

Update

This answer is, as I write this, nearly eight years old, and about five years stale. But it's still (as I write this) the "accepted" answer, because it answered the question when it was asked.

The newer answer, that applies to the newer Android Studio tools, can be found here: https://stackoverflow.com/a/35828035/62 -- it's a great answer with screen shots. If you're using Android Studio, ignore the Eclipse answer below.

Original Eclipse-based Answer

I was searching for the answer to this question, and was unsatisfied with the above answers. But then I found the answer, so here it is for future reference:

To summarize (and clarify), in Eclipse, go to "Debug Configurations". You can find that in the drop-down under the "debug" icon. Select "target", and select a preferred emulator target to launch. Then under "additional emulator command line options," add this:

-partition-size 1024

Then CLOSE the emulator (and remove any devices), and click the debug icon, which will launch the preferred emulator you selected. This is important: Eclipse needs to launch the debugger, not AVD.

That fixed the problem for me.

jQuery Ajax File Upload

If you want to upload file using AJAX here is code which you can use for file uploading.

$(document).ready(function() {
    var options = { 
                beforeSubmit:  showRequest,
        success:       showResponse,
        dataType: 'json' 
        }; 
    $('body').delegate('#image','change', function(){
        $('#upload').ajaxForm(options).submit();        
    }); 
});     
function showRequest(formData, jqForm, options) { 
    $("#validation-errors").hide().empty();
    $("#output").css('display','none');
    return true; 
} 
function showResponse(response, statusText, xhr, $form)  { 
    if(response.success == false)
    {
        var arr = response.errors;
        $.each(arr, function(index, value)
        {
            if (value.length != 0)
            {
                $("#validation-errors").append('<div class="alert alert-error"><strong>'+ value +'</strong><div>');
            }
        });
        $("#validation-errors").show();
    } else {
         $("#output").html("<img src='"+response.file+"' />");
         $("#output").css('display','block');
    }
}

Here is the HTML for Upload the file

<form class="form-horizontal" id="upload" enctype="multipart/form-data" method="post" action="upload/image'" autocomplete="off">
    <input type="file" name="image" id="image" /> 
</form>

PHP Warning: PHP Startup: Unable to load dynamic library

In Windows, it could be a wrong path in "System environment variables". "Path" to the php.exe directory must be the good one.

Changing the selected option of an HTML Select element

I want to change the select element's selected option's both value & textContent (what we see) to 'Mango'.

Simplest code that worked is below:

var newValue1 = 'Mango'

var selectElement = document.getElementById('myselectid');
selectElement.options[selectElement.selectedIndex].value = newValue1;
selectElement.options[selectElement.selectedIndex].textContent = newValue1;

Hope that helps someone. Best of luck.
Up vote if this helped you.

How to download and save a file from Internet using Java?

1st Method using the new channel

ReadableByteChannel aq = Channels.newChannel(new url("https//asd/abc.txt").openStream());
FileOutputStream fileOS = new FileOutputStream("C:Users/local/abc.txt")
FileChannel writech = fileOS.getChannel();

2nd Method using FileUtils

FileUtils.copyURLToFile(new url("https//asd/abc.txt",new local file on system("C":/Users/system/abc.txt"));

3rd Method using

InputStream xy = new ("https//asd/abc.txt").openStream();

This is how we can download file by using basic java code and other third-party libraries. These are just for quick reference. Please google with the above keywords to get detailed information and other options.

Can you delete data from influxdb?

It appears that you can do this in influxdb 0.9. For instance, here's a query that just succeeded for me:

DROP SERIES FROM temperature WHERE machine='zagbar'

(Per generous comment by @MuratCorlu, I'm reposting my earlier comment as an answer...)

IF EXISTS, THEN SELECT ELSE INSERT AND THEN SELECT

DECLARE @t1 TABLE (
    TableID     int         IDENTITY,
    FieldValue  varchar(20)
)

--<< No empty string
IF EXISTS (
    SELECT *
    FROM @t1
    WHERE FieldValue = ''
) BEGIN
    SELECT TableID
    FROM @t1
    WHERE FieldValue=''
END
ELSE BEGIN
    INSERT INTO @t1 (FieldValue) VALUES ('')
    SELECT SCOPE_IDENTITY() AS TableID
END

--<< A record with an empty string already exists
IF EXISTS (
    SELECT *
    FROM @t1
    WHERE FieldValue = ''
) BEGIN
    SELECT TableID
    FROM @t1
    WHERE FieldValue=''
END
ELSE BEGIN
    INSERT INTO @t1 (FieldValue) VALUES ('')
    SELECT SCOPE_IDENTITY() AS TableID
END

Update select2 data without rebuilding the control

Diego's comment on the answer given by SpinyMan is important because the empty() method will remove the select2 instance, so any custom options will no longer be retained. If you want to keep existing select2 options you must save them, destroy the existing select2 instance, and then re-initialize. You can do that like so:

const options = JSON.parse(JSON.stringify(
  $('#inputhidden').data('select2').options.options
));
options.data = data;

$('#inputhidden').empty().select2('destroy').select2(options);

I would recommend to always explicitly pass the select2 options however, because the above only copies over simple options and not any custom callbacks or adapters. Also note that this requires the latest stable release of select2 (4.0.13 at the time of this post).

I wrote generic functions to handle this with a few features:

  • can handle selectors that return multiple instances
  • use the existing select2's instance options (default) or pass in a new set of options
  • keep any already-selected values (default) that are still valid, or clear them entirely
function select2UpdateOptions(
  selector,
  data,
  newOptions = null,
  keepExistingSelected = true
) {
  // loop through all instances of the matching selector and update each instance
  $(selector).each(function() {
    select2InstanceUpdateOptions($(this), data, newOptions, keepExistingSelected);
  });
}

// update an existing select2 instance with new data options
function select2InstanceUpdateOptions(
  instance,
  data,
  newOptions = null,
  keepSelected = true
) {
  // make sure this instance has select2 initialized
  // @link https://select2.org/programmatic-control/methods#checking-if-the-plugin-is-initialized
  if (!instance.hasClass('select2-hidden-accessible')) {
    return;
  }

  // get the currently selected options
  const existingSelected = instance.val();

  // by default use the existing options of the select2 instance unless overridden
  // this will not copy over any callbacks or custom adapters however
  const options = (newOptions)
    ? newOptions
    : JSON.parse(JSON.stringify(instance.data('select2').options.options))
  ;

  // set the new data options that will be used
  options.data = data;
      
  // empty the select and destroy the existing select2 instance
  // then re-initialize the select2 instance with the given options and data
  instance.empty().select2('destroy').select2(options);
      
  // by default keep options that were already selected;
  // any that are now invalid will automatically be cleared
  if (keepSelected) {
    instance.val(existingSelected).trigger('change');
  }
}

Clang vs GCC - which produces faster binaries?

The only way to determine this is to try it. FWIW I have seen some really good improvements using Apple's LLVM gcc 4.2 compared to the regular gcc 4.2 (for x86-64 code with quite a lot of SSE), but YMMV for different code bases. Assuming you're working with x86/x86-64 and that you really do care about the last few percent then you ought to try Intel's ICC too, as this can often beat gcc - you can get a 30 day evaluation license from intel.com and try it.

JPA Hibernate Persistence exception [PersistenceUnit: default] Unable to build Hibernate SessionFactory

The issue is that you are not able to get a connection to MYSQL database and hence it is throwing an error saying that cannot build a session factory.

Please see the error below:

 Caused by: java.sql.SQLException: Access denied for user ''@'localhost' (using password: NO) 

which points to username not getting populated.

Please recheck system properties

dataSource.setUsername(System.getProperty("root"));

some packages seems to be missing as well pointing to a dependency issue:

package org.gjt.mm.mysql does not exist

Please run a mvn dependency:tree command to check for dependencies

AngularJS - $http.post send data as json

i think the most proper way is to use the same piece of code angular use when doing a "get" request using you $httpParamSerializer will have to inject it to your controller so you can simply do the following without having to use Jquery at all , $http.post(url,$httpParamSerializer({param:val}))

app.controller('ctrl',function($scope,$http,$httpParamSerializer){
  $http.post(url,$httpParamSerializer({param:val,secondParam:secondVal}));
}

Compare two dates with JavaScript

In order to create dates from free text in Javascript you need to parse it into the Date() object.

You could use Date.parse() which takes free text tries to convert it into a new date but if you have control over the page I would recommend using HTML select boxes instead or a date picker such as the YUI calendar control or the jQuery UI Datepicker.

Once you have a date as other people have pointed out you can use simple arithmetic to subtract the dates and convert it back into a number of days by dividing the number (in seconds) by the number of seconds in a day (60*60*24 = 86400).

How can I do time/hours arithmetic in Google Spreadsheet?

When the number being returned by your formula is being formatted as a time, and you want it formatted as a plain number, change the format of the cell to a plain number format: click the cell and then click Format, Number, Normal.

Time values in Google spreadsheet are represented as days and parts of days. For example, 36:00:00 is the formatted representation of the number 1.5 (a day and a half).

Suppose you divide 36:00:00 by 3:00:00, as in your example. Google Spreadsheet performs the calculation 1.5 divided by 0.125, which is 12. The result tells you that you have 12 3-hour intervals in a 36-hour time period. 12, of course, is not a time interval. It is a unitless quantity.

Going the other way, it is possible to format any number as a time. If you format 12 as a time, it's reasonable to expect that you will get 288:00:00. 12 days contain 288 hours.

Error in launching AVD with AMD processor

As many other pointed out, Intel HAXM only supports Intel CPUs. Since Windows 1804 you can use Microsoft's Hyper-V instead of HAXM for the emulator. This also helps people who want to use Hyper-V for virtual machines as you need to disable hyper-v to run haxm.

Short version:

  • install Windows Hypervisor Platform feature
  • Update to Android Emulator 27.2.7 or above
  • put WindowsHypervisorPlatform = on into C:\Users\your-username\.android\advancedFeatures.ini or start emulator or command line with -feature WindowsHypervisorPlatform
  • enable IOMMU in your BIOS settings

Long version with more details:

https://blogs.msdn.microsoft.com/visualstudio/2018/05/08/hyper-v-android-emulator-support/

Requirements docs:

https://docs.microsoft.com/en-us/windows-server/virtualization/hyper-v/system-requirements-for-hyper-v-on-windows

CSS rule to apply only if element has BOTH classes

Below applies to all tags with the following two classes

.abc.xyz {  
  width: 200px !important;
}

applies to div tags with the following two classes

div.abc.xyz {  
  width: 200px !important;
}

If you wanted to modify this using jQuery

$(document).ready(function() {
  $("div.abc.xyz").width("200px");
});

How to revert to origin's master branch's version of file

If you didn't commit it to the master branch yet, its easy:

  • get off the master branch (like git checkout -b oops/fluke/dang)
  • commit your changes there (like git add -u; git commit;)
  • go back the master branch (like git checkout master)

Your changes will be saved in branch oops/fluke/dang; master will be as it was.

Create a table without a header in Markdown

You may be able to hide a heading if you can add the following CSS:

<style>
    th {
        display: none;
    }
</style>

This is a bit heavy-handed and doesn’t distinguish between tables, but it may do for a simple task.

Comparing double values in C#

Comparing floating point number can't always be done precisely because of rounding. To compare

(x == .1)

the computer really compares

(x - .1) vs 0

Result of sybtraction can not always be represeted precisely because of how floating point number are represented on the machine. Therefore you get some nonzero value and the condition evaluates to false.

To overcome this compare

Math.Abs(x- .1) vs some very small threshold ( like 1E-9)

Convert generic list to dataset in C#

One option would be to use a System.ComponenetModel.BindingList rather than a list.

This allows you to use it directly within a DataGridView. And unlike a normal System.Collections.Generic.List updates the DataGridView on changes.

File tree view in Notepad++

You can also use you own computer built-in functions:

  • Create a file, write this on it:
tree /a /f >tree.txt
  • Save the file as any_name_you_want.BAT
  • Launch it, it will create a file named tree.txt that contains you directory TREE.

Excel CSV - Number cell format

The Text Import Wizard method does NOT work when the CSV file being imported has line breaks within a cell. This method handles this scenario(at least with tab delimited data):

  1. Create new Excel file
  2. Ctrl+A to select all cells
  3. In Number Format combobox, select Text
  4. Open tab delimited file in text editor
  5. Select all, copy and paste into Excel

Cannot install packages inside docker Ubuntu image

I found that mounting a local volume over /tmp can cause permission issues when the "apt-get update" runs, which prevents the package cache from being populated. Hopefully, this isn't something most people do, but it's something else to look for if you see this issue.

Found conflicts between different versions of the same dependent assembly that could not be resolved

I have uninstalled Microsoft ASP.NET MVC nuget.org from manage NuGet Packagaes and again re-installed it. While re-installing it resolved all the conflicts related to razor version. Try it .

How do I deal with special characters like \^$.?*|+()[{ in my regex?

I think the easiest way to match the characters like

\^$.?*|+()[

are using character classes from within R. Consider the following to clean column headers from a data file, which could contain spaces, and punctuation characters:

> library(stringr)
> colnames(order_table) <- str_replace_all(colnames(order_table),"[:punct:]|[:space:]","")

This approach allows us to string character classes to match punctation characters, in addition to whitespace characters, something you would normally have to escape with \\ to detect. You can learn more about the character classes at this cheatsheet below, and you can also type in ?regexp to see more info about this.

https://www.rstudio.com/wp-content/uploads/2016/09/RegExCheatsheet.pdf

How to execute a bash command stored as a string with quotes and asterisk

To eliminate the need for the cmd variable, you can do this:

eval 'mysql AMORE -u root --password="password" -h localhost -e "select host from amoreconfig"'

JSP tricks to make templating easier?

Based on the same basic idea as in @Will Hartung's answer, here is my magic one-tag extensible template engine. It even includes documentation and an example :-)

WEB-INF/tags/block.tag:

<%--
    The block tag implements a basic but useful extensible template system.

    A base template consists of a block tag without a 'template' attribute.
    The template body is specified in a standard jsp:body tag, which can
    contain EL, JSTL tags, nested block tags and other custom tags, but
    cannot contain scriptlets (scriptlets are allowed in the template file,
    but only outside of the body and attribute tags). Templates can be
    full-page templates, or smaller blocks of markup included within a page.

    The template is customizable by referencing named attributes within
    the body (via EL). Attribute values can then be set either as attributes
    of the block tag element itself (convenient for short values), or by
    using nested jsp:attribute elements (better for entire blocks of markup).

    Rendering a template block or extending it in a child template is then
    just a matter of invoking the block tag with the 'template' attribute set
    to the desired template name, and overriding template-specific attributes
    as necessary to customize it.

    Attribute values set when rendering a tag override those set in the template
    definition, which override those set in its parent template definition, etc.
    The attributes that are set in the base template are thus effectively used
    as defaults. Attributes that are not set anywhere are treated as empty.

    Internally, attributes are passed from child to parent via request-scope
    attributes, which are removed when rendering is complete.

    Here's a contrived example:

    ====== WEB-INF/tags/block.tag (the template engine tag)

    <the file you're looking at right now>

    ====== WEB-INF/templates/base.jsp (base template)

    <%@ page trimDirectiveWhitespaces="true" %>
    <%@ taglib prefix="t" tagdir="/WEB-INF/tags" %>
    <t:block>
        <jsp:attribute name="title">Template Page</jsp:attribute>
        <jsp:attribute name="style">
            .footer { font-size: smaller; color: #aaa; }
            .content { margin: 2em; color: #009; }
            ${moreStyle}
        </jsp:attribute>
        <jsp:attribute name="footer">
            <div class="footer">
                Powered by the block tag
            </div>
        </jsp:attribute>
        <jsp:body>
            <html>
                <head>
                    <title>${title}</title>
                    <style>
                        ${style}
                    </style>
                </head>
                <body>
                    <h1>${title}</h1>
                    <div class="content">
                        ${content}
                    </div>
                    ${footer}
                </body>
            </html>
        </jsp:body>
    </t:block>

    ====== WEB-INF/templates/history.jsp (child template)

    <%@ page trimDirectiveWhitespaces="true" %>
    <%@ taglib prefix="t" tagdir="/WEB-INF/tags" %>
    <t:block template="base" title="History Lesson">
        <jsp:attribute name="content" trim="false">
            <p>${shooter} shot first!</p>
        </jsp:attribute>
    </t:block>

    ====== history-1977.jsp (a page using child template)

    <%@ page trimDirectiveWhitespaces="true" %>
    <%@ taglib prefix="t" tagdir="/WEB-INF/tags" %>
    <t:block template="history" shooter="Han" />

    ====== history-1997.jsp (a page using child template)

    <%@ page trimDirectiveWhitespaces="true" %>
    <%@ taglib prefix="t" tagdir="/WEB-INF/tags" %>
    <t:block template="history" title="Revised History Lesson">
        <jsp:attribute name="moreStyle">.revised { font-style: italic; }</jsp:attribute>
        <jsp:attribute name="shooter"><span class="revised">Greedo</span></jsp:attribute>
    </t:block>

--%>

<%@ tag trimDirectiveWhitespaces="true" %>
<%@ tag import="java.util.HashSet, java.util.Map, java.util.Map.Entry" %>
<%@ tag dynamic-attributes="dynattributes" %>
<%@ attribute name="template" %>
<%
    // get template name (adding default .jsp extension if it does not contain
    // any '.', and /WEB-INF/templates/ prefix if it does not start with a '/')
    String template = (String)jspContext.getAttribute("template");
    if (template != null) {
        if (!template.contains("."))
            template += ".jsp";
        if (!template.startsWith("/"))
            template = "/WEB-INF/templates/" + template;
    }
    // copy dynamic attributes into request scope so they can be accessed from included template page
    // (child is processed before parent template, so only set previously undefined attributes)
    Map<String, String> dynattributes = (Map<String, String>)jspContext.getAttribute("dynattributes");
    HashSet<String> addedAttributes = new HashSet<String>();
    for (Map.Entry<String, String> e : dynattributes.entrySet()) {
        if (jspContext.getAttribute(e.getKey(), PageContext.REQUEST_SCOPE) == null) {
            jspContext.setAttribute(e.getKey(), e.getValue(), PageContext.REQUEST_SCOPE);
            addedAttributes.add(e.getKey());
        }
    }
%>

<% if (template == null) { // this is the base template itself, so render it %>
    <jsp:doBody/>
<% } else { // this is a page using the template, so include the template instead %>
    <jsp:include page="<%= template %>" />
<% } %>

<%
    // clean up the added attributes to prevent side effect outside the current tag
    for (String key : addedAttributes) {
        jspContext.removeAttribute(key, PageContext.REQUEST_SCOPE);
    }
%>

How do I resolve "Please make sure that the file is accessible and that it is a valid assembly or COM component"?

I had the same program, I hope this could help.

I your using Windows 7, open Command Prompt-> run as Administrator. register your <...>.dll.

Why run as Administrator, you can register your <...>.dll using the run at the Windows Start, but still your dll only run as user even your account is administrator.

Now you can add your <...>.dll at the Project->Add Reference->Browse

Thanks

Convert string to symbol-able in ruby

This is not answering the question itself, but I found this question searching for the solution to convert a string to symbol and use it on a hash.

hsh = Hash.new
str_to_symbol = "Book Author Title".downcase.gsub(/\s+/, "_").to_sym
hsh[str_to_symbol] = 10
p hsh
# => {book_author_title: 10}

Hope it helps someone like me!

Select default option value from typescript angular 6

First or all you are using ng-model which is considered to be an angularjs syntax. Use [(ngModel)] instead with the default value

App.component.html

<select [(ngModel)]='nrSelect' class='form-control'>
    <option value='47'>47</option>
    <option value='46'>46</option>
    <option value='45'>45</option>
</select>

App.component.ts

import { Component } from '@angular/core'; 
@Component({ 
    selector: 'my-app', 
    templateUrl: './app.component.html', 
    styleUrls: [ './app.component.css' ] 
}) 

export class AppComponent { 
    nrSelect:string = "47" 
}

INSERT INTO from two different server database

You cannot directly copy a table into a destination server database from a different database if source db is not in your linked servers. But one way is possible that, generate scripts (schema with data) of the desired table into one table temporarily in the source server DB, then execute the script in the destination server DB to create a table with your data. Finally use INSERT INTO [DESTINATION_TABLE] select * from [TEMPORARY_SOURCE_TABLE]. After getting the data into your destination table drop the temporary one.

I found this solution when I faced the same situation. Hope this helps you too.

mysqldump & gzip commands to properly create a compressed file of a MySQL database using crontab

Personally, I have create a file.sh (right 755) in the root directory, file who do this job, on order of the crontab.

Crontab code:

10 2 * * * root /root/backupautomatique.sh

File.sh code:

rm -f /home/mordb-148-251-89-66.sql.gz #(To erase the old one)

mysqldump mor | gzip > /home/mordb-148-251-89-66.sql.gz (what you have done)

scp -P2222 /home/mordb-148-251-89-66.sql.gz root@otherip:/home/mordbexternes/mordb-148-251-89-66.sql.gz

(to send a copy somewhere else if the sending server crashes, because too old, like me ;-))

Select values from XML field in SQL Server 2008

SELECT 
cast(xmlField as xml).value('(/person//firstName/node())[1]', 'nvarchar(max)') as FirstName,
cast(xmlField as xml).value('(/person//lastName/node())[1]', 'nvarchar(max)') as LastName
FROM [myTable]

How to log a method's execution time exactly in milliseconds?

NSDate *methodStart = [NSDate date];

/* ... Do whatever you need to do ... */

NSDate *methodFinish = [NSDate date];
NSTimeInterval executionTime = [methodFinish timeIntervalSinceDate:methodStart];
NSLog(@"executionTime = %f", executionTime);

Swift:

let methodStart = NSDate()

/* ... Do whatever you need to do ... */

let methodFinish = NSDate()
let executionTime = methodFinish.timeIntervalSinceDate(methodStart)
print("Execution time: \(executionTime)")

Swift3:

let methodStart = Date()

/* ... Do whatever you need to do ... */

let methodFinish = Date()
let executionTime = methodFinish.timeIntervalSince(methodStart)
print("Execution time: \(executionTime)")

Easy to use and has sub-millisecond precision.

Java - Convert String to valid URI object

I ended up using the httpclient-4.3.6:

import org.apache.http.client.utils.URIBuilder;
public static void main (String [] args) {
    URIBuilder uri = new URIBuilder();
    uri.setScheme("http")
    .setHost("www.example.com")
    .setPath("/somepage.php")
    .setParameter("username", "Hello Günter")
    .setParameter("p1", "parameter 1");
    System.out.println(uri.toString());
}

Output will be:

http://www.example.com/somepage.php?username=Hello+G%C3%BCnter&p1=paramter+1

How do I set up CLion to compile and run?

I met some problems in Clion and finally, I solved them. Here is some experience.

  1. Download and install MinGW
  2. g++ and gcc package should be installed by default. Use the MinGW installation manager to install mingw32-libz and mingw32-make. You can open MinGW installation manager through C:\MinGW\libexec\mingw-get.exe This step is the most important step. If Clion cannot find make, C compiler and C++ compiler, recheck the MinGW installation manager to make every necessary package is installed.
  3. In Clion, open File->Settings->Build,Execution,Deployment->Toolchains. Set MinGW home as your local MinGW file.
  4. Start your "Hello World"!

Jquery to open Bootstrap v3 modal of remote url

If using @worldofjr answer in jQuery you are getting error:

e.relatedTarget.data is not a function

you should use:

$('#myModal').on('show.bs.modal', function (e) {
    var loadurl = $(e.relatedTarget).data('load-url');
    $(this).find('.modal-body').load(loadurl);
});

Not that e.relatedTarget if wrapped by $(..)

I was getting the error in latest Bootstrap 3 and after using this method it's working without any problem.

jQuery .scrollTop(); + animation

Try this instead:

var body = $("body, html");
var top = body.scrollTop() // Get position of the body
if(top!=0)
{
       body.animate({scrollTop :0}, 500,function(){
         //DO SOMETHING AFTER SCROLL ANIMATION COMPLETED
          alert('Hello');
      });
}

how to configure apache server to talk to HTTPS backend server?

Your server tells you exactly what you need : [Hint: SSLProxyEngine]

You need to add that directive to your VirtualHost before the Proxy directives :

SSLProxyEngine on
ProxyPass /primary/store https://localhost:9763/store/
ProxyPassReverse /primary/store https://localhost:9763/store/

See the doc for more detail.

How do I manually configure a DataSource in Java?

Basically in JDBC most of these properties are not configurable in the API like that, rather they depend on implementation. The way JDBC handles this is by allowing the connection URL to be different per vendor.

So what you do is register the driver so that the JDBC system can know what to do with the URL:

 DriverManager.registerDriver((Driver) Class.forName("com.mysql.jdbc.Driver").newInstance());

Then you form the URL:

 String url = "jdbc:mysql://[host][,failoverhost...][:port]/[database][?propertyName1][=propertyValue1][&propertyName2][=propertyValue2]"

And finally, use it to get a connection:

 Connection c = DriverManager.getConnection(url);

In more sophisticated JDBC, you get involved with connection pools and the like, and application servers often have their own way of registering drivers in JNDI and you look up a DataSource from there, and call getConnection on it.

In terms of what properties MySQL supports, see here.

EDIT: One more thought, technically just having a line of code which does Class.forName("com.mysql.jdbc.Driver") should be enough, as the class should have its own static initializer which registers a version, but sometimes a JDBC driver doesn't, so if you aren't sure, there is little harm in registering a second one, it just creates a duplicate object in memeory.

What happened to Lodash _.pluck?

Ah-ha! The Lodash Changelog says it all...

"Removed _.pluck in favor of _.map with iteratee shorthand"

var objects = [{ 'a': 1 }, { 'a': 2 }];

// in 3.10.1
_.pluck(objects, 'a'); // ? [1, 2]
_.map(objects, 'a'); // ? [1, 2]

// in 4.0.0
_.map(objects, 'a'); // ? [1, 2]

Redirecting to URL in Flask

Flask includes the redirect function for redirecting to any url. Futhermore, you can abort a request early with an error code with abort:

from flask import abort, Flask, redirect, url_for

app = Flask(__name__)

@app.route('/')
def hello():
    return redirect(url_for('hello'))

@app.route('/hello'):
def world:
    abort(401)

By default a black and white error page is shown for each error code.

The redirect method takes by default the code 302. A list for http status codes here.

How to right-align and justify-align in Markdown?

If you want to use justify align in Jupyter Notebook use the following syntax:

<p style='text-align: justify;'> Your Text </p>

For right alignment:

<p style='text-align: right;'> Your Text </p>

process.start() arguments

Try fully qualifying the filenames in the arguments - I notice you're specifying the path in the FileName part, so it's possible that the process is being started elsewhere, then not finding the arguments and causing an error.

If that works, then setting the WorkingDirectory property on the StartInfo may be of use.

Actually, according to the link

The WorkingDirectory property must be set if UserName and Password are provided. If the property is not set, the default working directory is %SYSTEMROOT%\system32.

Use child_process.execSync but keep output in console

Simply:

 try {
    const cmd = 'git rev-parse --is-inside-work-tree';
    execSync(cmd).toString();
 } catch (error) {
    console.log(`Status Code: ${error.status} with '${error.message}'`;
 }

Ref: https://stackoverflow.com/a/43077917/104085

// nodejs
var execSync = require('child_process').execSync;

// typescript
const { execSync } = require("child_process");

 try {
    const cmd = 'git rev-parse --is-inside-work-tree';
    execSync(cmd).toString();
 } catch (error) {
    error.status;  // 0 : successful exit, but here in exception it has to be greater than 0
    error.message; // Holds the message you typically want.
    error.stderr;  // Holds the stderr output. Use `.toString()`.
    error.stdout;  // Holds the stdout output. Use `.toString()`.
 }

enter image description here

enter image description here

When command runs successful: enter image description here

Pure JavaScript Send POST Data Without a Form

The [new-ish at the time of writing in 2017] Fetch API is intended to make GET requests easy, but it is able to POST as well.

let data = {element: "barium"};

fetch("/post/data/here", {
  method: "POST", 
  body: JSON.stringify(data)
}).then(res => {
  console.log("Request complete! response:", res);
});

If you are as lazy as me (or just prefer a shortcut/helper):

window.post = function(url, data) {
  return fetch(url, {method: "POST", body: JSON.stringify(data)});
}

// ...

post("post/data/here", {element: "osmium"});

Simple (non-secure) hash function for JavaScript?

// Simple but unreliable function to create string hash by Sergey.Shuchkin [t] gmail.com
// alert( strhash('http://www.w3schools.com/js/default.asp') ); // 6mn6tf7st333r2q4o134o58888888888
function strhash( str ) {
    if (str.length % 32 > 0) str += Array(33 - str.length % 32).join("z");
    var hash = '', bytes = [], i = j = k = a = 0, dict = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','1','2','3','4','5','6','7','8','9'];
    for (i = 0; i < str.length; i++ ) {
        ch = str.charCodeAt(i);
        bytes[j++] = (ch < 127) ? ch & 0xFF : 127;
    }
    var chunk_len = Math.ceil(bytes.length / 32);   
    for (i=0; i<bytes.length; i++) {
        j += bytes[i];
        k++;
        if ((k == chunk_len) || (i == bytes.length-1)) {
            a = Math.floor( j / k );
            if (a < 32)
                hash += '0';
            else if (a > 126)
                hash += 'z';
            else
                hash += dict[  Math.floor( (a-32) / 2.76) ];
            j = k = 0;
        }
    }
    return hash;
}

whitespaces in the path of windows filepath

path = r"C:\Users\mememe\Google Drive\Programs\Python\file.csv"

Closing the path in r"string" also solved this problem very well.

VBA check if file exists

Maybe it caused by Filename variable

File = TextBox1.Value

It should be

Filename = TextBox1.Value

Missing XML comment for publicly visible type or member

I got that message after attached an attribute to a method

[webMethod]
public void DoSomething()
{
}

But the correct way was this:

[webMethod()] // Note the Parentheses 
public void DoSomething()
{
}

Any way to return PHP `json_encode` with encode UTF-8 and not Unicode?

{"a":"\u00e1"} and {"a":"á"} are different ways to write the same JSON document; The JSON decoder will decode the unicode escape.

In php 5.4+, php's json_encode does have the JSON_UNESCAPED_UNICODE option for plain output. On older php versions, you can roll out your own JSON encoder that does not encode non-ASCII characters, or use Pear's JSON encoder and remove line 349 to 433.

Get root password for Google Cloud Engine VM

I had the same problem. Even after updating the password using sudo passwd it was not working. I had to give "multiple" roles for my user through IAM & Admin Refer Screen Shot on IAM & Admin screen of google cloud

After that i restarted the VM. Then again changed the password and then it worked.

user1@sap-hanaexpress-public-1-vm:~> sudo passwd
New password: 
Retype new password: 
passwd: password updated successfully
user1@sap-hanaexpress-public-1-vm:~> su
Password: 
sap-hanaexpress-public-1-vm:/home/user1 # whoami
root
sap-hanaexpress-public-1-vm:/home/user1 #

Why do many examples use `fig, ax = plt.subplots()` in Matplotlib/pyplot/python

As a supplement to the question and above answers there is also an important difference between plt.subplots() and plt.subplot(), notice the missing 's' at the end.

One can use plt.subplots() to make all their subplots at once and it returns the figure and axes (plural of axis) of the subplots as a tuple. A figure can be understood as a canvas where you paint your sketch.

# create a subplot with 2 rows and 1 columns
fig, ax = plt.subplots(2,1)

Whereas, you can use plt.subplot() if you want to add the subplots separately. It returns only the axis of one subplot.

fig = plt.figure() # create the canvas for plotting
ax1 = plt.subplot(2,1,1) 
# (2,1,1) indicates total number of rows, columns, and figure number respectively
ax2 = plt.subplot(2,1,2)

However, plt.subplots() is preferred because it gives you easier options to directly customize your whole figure

# for example, sharing x-axis, y-axis for all subplots can be specified at once
fig, ax = plt.subplots(2,2, sharex=True, sharey=True)

Shared axes whereas, with plt.subplot(), one will have to specify individually for each axis which can become cumbersome.

Print a list of space-separated elements in Python 3

Joining elements in a list space separated:

word = ["test", "crust", "must", "fest"]
word.reverse()
joined_string = ""
for w in word:
   joined_string = w + joined_string + " "
print(joined_string.rstrim())

Numpy array dimensions

a.shape is just a limited version of np.info(). Check this out:

import numpy as np
a = np.array([[1,2],[1,2]])
np.info(a)

Out

class:  ndarray
shape:  (2, 2)
strides:  (8, 4)
itemsize:  4
aligned:  True
contiguous:  True
fortran:  False
data pointer: 0x27509cf0560
byteorder:  little
byteswap:  False
type: int32

How to prepare a Unity project for git?

On the Unity Editor open your project and:

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

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

cd to/your/unity/project/folder

git init

git add *

git commit -m "First commit"

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

git push -u origin master

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

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

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

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

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

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

How to make Java Set?

Like this:

import java.util.*;
Set<Integer> a = new HashSet<Integer>();
a.add( 1);
a.add( 2);
a.add( 3);

Or adding from an Array/ or multiple literals; wrap to a list, first.

Integer[] array = new Integer[]{ 1, 4, 5};
Set<Integer> b = new HashSet<Integer>();
b.addAll( Arrays.asList( b));         // from an array variable
b.addAll( Arrays.asList( 8, 9, 10));  // from literals

To get the intersection:

// copies all from A;  then removes those not in B.
Set<Integer> r = new HashSet( a);
r.retainAll( b);
// and print;   r.toString() implied.
System.out.println("A intersect B="+r);

Hope this answer helps. Vote for it!

CSS Grid Layout not working in IE11 even with prefixes

The answer has been given by Faisal Khurshid and Michael_B already.
This is just an attempt to make a possible solution more obvious.

For IE11 and below you need to enable grid's older specification in the parent div e.g. body or like here "grid" like so:

.grid-parent{display:-ms-grid;}

then define the amount and width of the columns and rows like e.g. so:

.grid-parent{
  -ms-grid-columns: 1fr 3fr;
  -ms-grid-rows: 4fr;
}

finally you need to explicitly tell the browser where your element (item) should be placed in e.g. like so:

.grid-item-1{
  -ms-grid-column: 1;
  -ms-grid-row: 1;
}

.grid-item-2{
  -ms-grid-column: 2;
  -ms-grid-row: 1;
}

Gulp command not found after install

Not sure why the question was down-voted, but I had the same issue and following the blog post recommended solve the issue. One thing I should add is that in my case, once I ran:

npm config set prefix /usr/local

I confirmed the npm root -g was pointing to /usr/local/lib/node_modules/npm, but in order to install gulp in /usr/local/lib/node_modules, I had to use sudo:

sudo npm install gulp -g

How do I extend a class with c# extension methods?

They provide the capability to extend existing types by adding new methods with no modifications necessary to the type. Calling methods from objects of the extended type within an application using instance method syntax is known as ‘‘extending’’ methods. Extension methods are not instance members on the type. The key point to remember is that extension methods, defined as static methods, are in scope only when the namespace is explicitly imported into your application source code via the using directive. Even though extension methods are defined as static methods, they are still called using instance syntax.

Check the full example here http://www.dotnetreaders.com/articles/Extension_methods_in_C-sharp.net,Methods_in_C_-sharp/201

Example:

class Extension
    {
        static void Main(string[] args)
        {
            string s = "sudhakar";
            Console.WriteLine(s.GetWordCount());
            Console.ReadLine();
        }

    }
    public static class MyMathExtension
    {

        public static int GetWordCount(this System.String mystring)
        {
            return mystring.Length;
        }
    }

Performing Inserts and Updates with Dapper

You can try this:

 string sql = "UPDATE Customer SET City = @City WHERE CustomerId = @CustomerId";             
 conn.Execute(sql, customerEntity);

Warning comparison between pointer and integer

In this line ...

if (*message == "\0") {

... as you can see in the warning ...

warning: comparison between pointer and integer
      ('int' and 'char *')

... you are actually comparing an int with a char *, or more specifically, an int with an address to a char.

To fix this, use one of the following:

if(*message == '\0') ...
if(message[0] == '\0') ...
if(!*message) ...

On a side note, if you'd like to compare strings you should use strcmp or strncmp, found in string.h.

How do I remove a key from a JavaScript object?

It's as easy as:

delete object.keyname;

or

delete object["keyname"];

How to show PIL Image in ipython notebook

Based on other answers and my tries, best experience would be first installing, pillow and scipy, then using the following starting code on your jupyter notebook:

%matplotlib inline
from matplotlib.pyplot import imshow
from scipy.misc import imread

imshow(imread('image.jpg', 1))

Get last key-value pair in PHP array

Like said Gumbo,

<?php

$fruits = array('apple', 'banana', 'cranberry');
echo end($fruits); // cranberry

?>

link_to method and click event in Rails

just use

=link_to "link", "javascript:function()"

Fastest way to reset every value of std::vector<int> to 0

As always when you ask about fastest: Measure! Using the Methods above (on a Mac using Clang):

Method      |  executable size  |  Time Taken (in sec) |
            |  -O0    |  -O3    |  -O0      |  -O3     |  
------------|---------|---------|-----------|----------|
1. memset   | 17 kB   | 8.6 kB  | 0.125     | 0.124    |
2. fill     | 19 kB   | 8.6 kB  | 13.4      | 0.124    |
3. manual   | 19 kB   | 8.6 kB  | 14.5      | 0.124    |
4. assign   | 24 kB   | 9.0 kB  | 1.9       | 0.591    |

using 100000 iterations on an vector of 10000 ints.

Edit: If changeing this numbers plausibly changes the resulting times you can have some confidence (not as good as inspecting the final assembly code) that the artificial benchmark has not been optimized away entirely. Of course it is best to messure the performance under real conditions. end Edit

for reference the used code:

#include <vector>

#define TEST_METHOD 1
const size_t TEST_ITERATIONS = 100000;
const size_t TEST_ARRAY_SIZE = 10000;

int main(int argc, char** argv) {

   std::vector<int> v(TEST_ARRAY_SIZE, 0);

   for(size_t i = 0; i < TEST_ITERATIONS; ++i) {
   #if TEST_METHOD == 1 
      memset(&v[0], 0, v.size() * sizeof v[0]);
   #elif TEST_METHOD == 2
      std::fill(v.begin(), v.end(), 0);
   #elif TEST_METHOD == 3
      for (std::vector<int>::iterator it=v.begin(), end=v.end(); it!=end; ++it) {
         *it = 0;
      }
   #elif TEST_METHOD == 4
      v.assign(v.size(),0);
   #endif
   }

   return EXIT_SUCCESS;
}

Conclusion: use std::fill (because, as others have said its most idiomatic)!

How do I create an Excel chart that pulls data from multiple sheets?

2007 is more powerful with ribbon..:=) To add new series in chart do: Select Chart, then click Design in Chart Tools on the ribbon, On the Design ribbon, select "Select Data" in Data Group, Then you will see the button for Add to add new series.

Hope that will help.

When do we need curly braces around shell variables?

Variables are declared and assigned without $ and without {}. You have to use

var=10

to assign. In order to read from the variable (in other words, 'expand' the variable), you must use $.

$var      # use the variable
${var}    # same as above
${var}bar # expand var, and append "bar" too
$varbar   # same as ${varbar}, i.e expand a variable called varbar, if it exists.

This has confused me sometimes - in other languages we refer to the variable in the same way, regardless of whether it's on the left or right of an assignment. But shell-scripting is different, $var=10 doesn't do what you might think it does!

Pip freeze vs. pip list

To answer the second part of this question, the two packages shown in pip list but not pip freeze are setuptools (which is easy_install) and pip itself.

It looks like pip freeze just doesn't list packages that pip itself depends on. You may use the --all flag to show also those packages.

From the documentation:

--all

Do not skip these packages in the output: pip, setuptools, distribute, wheel

Best way to convert strings to symbols in hash

Here's a way to deep symbolize an object

def symbolize(obj)
    return obj.inject({}){|memo,(k,v)| memo[k.to_sym] =  symbolize(v); memo} if obj.is_a? Hash
    return obj.inject([]){|memo,v    | memo           << symbolize(v); memo} if obj.is_a? Array
    return obj
end

Session 'app': Error Installing APK

Usage of easily changing variable value will often happen in build.gradle(like the Date)

enter image description here

jQuery find element by data attribute value

Use Attribute Equals Selector

$('.slide-link[data-slide="0"]').addClass('active');

Fiddle Demo

.find()

it works down the tree

Get the descendants of each element in the current set of matched elements, filtered by a selector, jQuery object, or element.

window.location.reload with clear cache

i had this problem and i solved it using javascript

 location.reload(true);

you may also use

window.history.forward(1);

to stop the browser back button after user logs out of the application.

jQuery ajax call to REST service

From the use of 8080 I'm assuming you are using a tomcat servlet container to serve your rest api. If this is the case you can also consider to have your webserver proxy the requests to the servlet container.

With apache you would typically use mod_jk (although there are other alternatives) to serve the api trough the web server behind port 80 instead of 8080 which would solve the cross domain issue.

This is common practice, have the 'static' content in the webserver and dynamic content in the container, but both served from behind the same domain.

The url for the rest api would be http://localhost/restws/json/product/get

Here a description on how to use mod_jk to connect apache to tomcat: http://tomcat.apache.org/connectors-doc/webserver_howto/apache.html

Removing rounded corners from a <select> element in Chrome/Webkit

Solution with custom right drop-down arrow, uses only css (no images)

_x000D_
_x000D_
select {_x000D_
  -webkit-appearance: none;_x000D_
  -webkit-border-radius: 0px;_x000D_
  background-image: linear-gradient(45deg, transparent 50%, gray 50%), linear-gradient(135deg, gray 50%, transparent 50%);_x000D_
  background-position: calc(100% - 20px) calc(1em + 2px), calc(100% - 15px) calc(1em + 2px), calc(100% - 2.5em) 0.5em;_x000D_
  background-size: 5px 5px, 5px 5px, 1px 1.5em;_x000D_
  background-repeat: no-repeat;_x000D_
_x000D_
  -moz-appearance: none;_x000D_
  display: block;_x000D_
  padding: 0.3rem;_x000D_
  height: 2rem;_x000D_
  width: 100%;_x000D_
}
_x000D_
<html>_x000D_
_x000D_
<body>_x000D_
  <br/>_x000D_
  <h4>Example</h4>_x000D_
  <select>_x000D_
    <option></option>_x000D_
    <option>Hello</option>_x000D_
    <option>World</option>_x000D_
  </select>_x000D_
</body>_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_

Changing default shell in Linux

You can change the passwd file directly for the particular user or use the below command

chsh -s /usr/local/bin/bash username

Then log out and log in

Purpose of Unions in C and C++

Although this is strictly undefined behaviour, in practice it will work with pretty much any compiler. It is such a widely used paradigm that any self-respecting compiler will need to do "the right thing" in cases such as this. It's certainly to be preferred over type-punning, which may well generate broken code with some compilers.

Python group by

The following function will quickly (no sorting required) group tuples of any length by a key having any index:

# given a sequence of tuples like [(3,'c',6),(7,'a',2),(88,'c',4),(45,'a',0)],
# returns a dict grouping tuples by idx-th element - with idx=1 we have:
# if merge is True {'c':(3,6,88,4),     'a':(7,2,45,0)}
# if merge is False {'c':((3,6),(88,4)), 'a':((7,2),(45,0))}
def group_by(seqs,idx=0,merge=True):
    d = dict()
    for seq in seqs:
        k = seq[idx]
        v = d.get(k,tuple()) + (seq[:idx]+seq[idx+1:] if merge else (seq[:idx]+seq[idx+1:],))
        d.update({k:v})
    return d

In the case of your question, the index of key you want to group by is 1, therefore:

group_by(input,1)

gives

{'ETH': ('5238761','5349618','962142','7795297','7341464','5594916','1550003'),
 'KAT': ('11013331', '9843236'),
 'NOT': ('9085267', '11788544')}

which is not exactly the output you asked for, but might as well suit your needs.

how to get docker-compose to use the latest image from repository

I am using following command to get latest images

sudo docker-compose down -rmi all

sudo docker-compose up -d

Live search through table rows

I took yckart's answer and:

  • spaced it out for readability
  • case insensitive search
  • there was a bug in the comparison that was fixed by adding .trim()

(If you put your scripts at the bottom of your page below the jQuery include you shouldn't need document ready)

jQuery:

 <script>
    $(".card-table-search").keyup(function() {
        var value = this.value.toLowerCase().trim();

        $(".card-table").find("tr").each(function(index) {
            var id = $(this).find("td").first().text().toLowerCase().trim();
            $(this).toggle(id.indexOf(value) !== -1);
        });
    });
 </script>

If you want to extend this have it iterate over each 'td' and do this comparison.

How to my "exe" from PyCharm project

You cannot directly save a Python file as an exe and expect it to work -- the computer cannot automatically understand whatever code you happened to type in a text file. Instead, you need to use another program to transform your Python code into an exe.

I recommend using a program like Pyinstaller. It essentially takes the Python interpreter and bundles it with your script to turn it into a standalone exe that can be run on arbitrary computers that don't have Python installed (typically Windows computers, since Linux tends to come pre-installed with Python).

To install it, you can either download it from the linked website or use the command:

pip install pyinstaller

...from the command line. Then, for the most part, you simply navigate to the folder containing your source code via the command line and run:

pyinstaller myscript.py

You can find more information about how to use Pyinstaller and customize the build process via the documentation.


You don't necessarily have to use Pyinstaller, though. Here's a comparison of different programs that can be used to turn your Python code into an executable.

Any way to make plot points in scatterplot more transparent in R?

Transparency can be coded in the color argument as well. It is just two more hex numbers coding a transparency between 0 (fully transparent) and 255 (fully visible). I once wrote this function to add transparency to a color vector, maybe it is usefull here?

addTrans <- function(color,trans)
{
  # This function adds transparancy to a color.
  # Define transparancy with an integer between 0 and 255
  # 0 being fully transparant and 255 being fully visable
  # Works with either color and trans a vector of equal length,
  # or one of the two of length 1.

  if (length(color)!=length(trans)&!any(c(length(color),length(trans))==1)) stop("Vector lengths not correct")
  if (length(color)==1 & length(trans)>1) color <- rep(color,length(trans))
  if (length(trans)==1 & length(color)>1) trans <- rep(trans,length(color))

  num2hex <- function(x)
  {
    hex <- unlist(strsplit("0123456789ABCDEF",split=""))
    return(paste(hex[(x-x%%16)/16+1],hex[x%%16+1],sep=""))
  }
  rgb <- rbind(col2rgb(color),trans)
  res <- paste("#",apply(apply(rgb,2,num2hex),2,paste,collapse=""),sep="")
  return(res)
}

Some examples:

cols <- sample(c("red","green","pink"),100,TRUE)

# Fully visable:
plot(rnorm(100),rnorm(100),col=cols,pch=16,cex=4)

# Somewhat transparant:
plot(rnorm(100),rnorm(100),col=addTrans(cols,200),pch=16,cex=4)

# Very transparant:
plot(rnorm(100),rnorm(100),col=addTrans(cols,100),pch=16,cex=4)

Mongoose delete array element in document and save

The checked answer does work but officially in MongooseJS latest, you should use pull.

doc.subdocs.push({ _id: 4815162342 }) // added
doc.subdocs.pull({ _id: 4815162342 }) // removed

https://mongoosejs.com/docs/api.html#mongoosearray_MongooseArray-pull

I was just looking that up too.

See Daniel's answer for the correct answer. Much better.

How do you build a Singleton in Dart?

As I'm not very fond of using the new keyword or other constructor like calls on singletons, I would prefer to use a static getter called inst for example:

// the singleton class
class Dao {
    // singleton boilerplate
        Dao._internal() {}
        static final Dao _singleton = new Dao._internal();
        static get inst => _singleton;

    // business logic
        void greet() => print("Hello from singleton");
}

example usage:

Dao.inst.greet();       // call a method

// Dao x = new Dao();   // compiler error: Method not found: 'Dao'

// verify that there only exists one and only one instance
assert(identical(Dao.inst, Dao.inst));

Convert SVG to PNG in Python

I'm using Wand-py (an implementation of the Wand wrapper around ImageMagick) to import some pretty advanced SVGs and so far have seen great results! This is all the code it takes:

    with wand.image.Image( blob=svg_file.read(), format="svg" ) as image:
        png_image = image.make_blob("png")

I just discovered this today, and felt like it was worth sharing for anyone else who might straggle across this answer as it's been a while since most of these questions were answered.

NOTE: Technically in testing I discovered you don't even actually have to pass in the format parameter for ImageMagick, so with wand.image.Image( blob=svg_file.read() ) as image: was all that was really needed.

EDIT: From an attempted edit by qris, here's some helpful code that lets you use ImageMagick with an SVG that has a transparent background:

from wand.api import library
import wand.color
import wand.image

with wand.image.Image() as image:
    with wand.color.Color('transparent') as background_color:
        library.MagickSetBackgroundColor(image.wand, 
                                         background_color.resource) 
    image.read(blob=svg_file.read(), format="svg")
    png_image = image.make_blob("png32")

with open(output_filename, "wb") as out:
    out.write(png_image)

Write HTML to string

You could use some third party open-source libraries to generated strong typed verified (X)HTML, such as CityLizard Framework or Sharp DOM.

Update For example

html
    [head
        [title["Title of the page"]]
        [meta_(
            content: "text/html;charset=UTF-8",
            http_equiv: "Content-Type")
        ]
        [link_(href: "css/style.css", rel: "stylesheet", type: "text/css")]
        [script_(type: "text/javascript", src: "/JavaScript/jquery-1.4.2.min.js")]
    ]
    [body
        [div
            [h1["Test Form to Test"]]
            [form_(action: "post", id: "Form1")
                [div
                    [label["Parameter"]]
                    [input_(type: "text", value: "Enter value")]
                    [input_(type: "submit", value: "Submit!")]
                ]
            ]
            [div
                [p["Textual description of the footer"]]
                [a_(href: "http://google.com/")
                    [span["You can find us here"]]
                ]
                [div["Another nested container"]]
            ]
        ]
    ];

Javascript Audio Play on click

JavaScript

function playAudio(url) {
  new Audio(url).play();
}


HTML

<img src="image.png" onclick="playAudio('mysound.mp3')">


Supported in most modern browsers and easy to embed into HTML elements.

Batch file to restart a service. Windows

net stop <your service> && net start <your service>

No net restart, unfortunately.

Access camera from a browser

The HTML5 spec does allow accessing the webcamera, but last I checked, it is far from finalized, and has very, very little browser support.

This is a link to get you started: http://www.html5rocks.com/en/tutorials/getusermedia/intro/

You'll probably have to use flash if you want it to work cross-browser.

W3 draft

What is causing ERROR: there is no unique constraint matching given keys for referenced table?

when you do UNIQUE as a table level constraint as you have done then what your defining is a bit like a composite primary key see ddl constraints, here is an extract

"This specifies that the *combination* of values in the indicated columns is unique across the whole table, though any one of the columns need not be (and ordinarily isn't) unique."

this means that either field could possibly have a non unique value provided the combination is unique and this does not match your foreign key constraint.

most likely you want the constraint to be at column level. so rather then define them as table level constraints, 'append' UNIQUE to the end of the column definition like name VARCHAR(60) NOT NULL UNIQUE or specify indivdual table level constraints for each field.

How to define partitioning of DataFrame?

So to start with some kind of answer : ) - You can't

I am not an expert, but as far as I understand DataFrames, they are not equal to rdd and DataFrame has no such thing as Partitioner.

Generally DataFrame's idea is to provide another level of abstraction that handles such problems itself. The queries on DataFrame are translated into logical plan that is further translated to operations on RDDs. The partitioning you suggested will probably be applied automatically or at least should be.

If you don't trust SparkSQL that it will provide some kind of optimal job, you can always transform DataFrame to RDD[Row] as suggested in of the comments.

What happens when a duplicate key is put into a HashMap?

To your question whether the map was like a bucket: no.

It's like a list with name=value pairs whereas name doesn't need to be a String (it can, though).

To get an element, you pass your key to the get()-method which gives you the assigned object in return.

And a Hashmap means that if you're trying to retrieve your object using the get-method, it won't compare the real object to the one you provided, because it would need to iterate through its list and compare() the key you provided with the current element.

This would be inefficient. Instead, no matter what your object consists of, it calculates a so called hashcode from both objects and compares those. It's easier to compare two ints instead of two entire (possibly deeply complex) objects. You can imagine the hashcode like a summary having a predefined length (int), therefore it's not unique and has collisions. You find the rules for the hashcode in the documentation to which I've inserted the link.

If you want to know more about this, you might wanna take a look at articles on javapractices.com and technofundo.com

regards

How to add a new object (key-value pair) to an array in javascript?

If you're doing jQuery, and you've got a serializeArray thing going on concerning your form data, such as :

var postData = $('#yourform').serializeArray();

// postData (array with objects) : 
// [{name: "firstname", value: "John"}, {name: "lastname", value: "Doe"}, etc]

...and you need to add a key/value to this array with the same structure, for instance when posting to a PHP ajax request then this :

postData.push({"name": "phone", "value": "1234-123456"});

Result:

// postData : 
// [{name: "firstname", value: "John"}, {name: "lastname", value: "Doe"}, {"name":"phone","value":"1234-123456"}]

Concatenate string with field value in MySQL

Here is a great answer to that:

SET sql_mode='PIPES_AS_CONCAT';

Find more here: https://stackoverflow.com/a/24777235/4120319

Here's the full SQL:

SET sql_mode='PIPES_AS_CONCAT';

SELECT * FROM tableOne 
LEFT JOIN tableTwo
ON tableTwo.query = 'category_id=' || tableOne.category_id;

How to do case insensitive string comparison?

if you are concerned about the direction of the inequality (perhaps you want to sort a list) you pretty-much have to do case-conversion, and as there are more lowercase characters in unicode than uppercase toLowerCase is probably the best conversion to use.

function my_strcasecmp( a, b ) 
{
    if((a+'').toLowerCase() > (b+'').toLowerCase()) return 1  
    if((a+'').toLowerCase() < (b+'').toLowerCase()) return -1
    return 0
}

Javascript seems to use locale "C" for string comparisons so the resulting ordering will be ugly if the strings contain other than ASCII letters. there's not much that can be done about that without doing much more detailed inspection of the strings.

Can't import database through phpmyadmin file size too large

Another option that nobody here has mentioned yet is to do a staggered load of the database using a tool like BigDump to work around the limit. It's a simple PHP script that loads a chunk of the database at a time before restarting itself and moving on the the next chunk.

Code for printf function in C

Here's the GNU version of printf... you can see it passing in stdout to vfprintf:

__printf (const char *format, ...)
{
   va_list arg;
   int done;

   va_start (arg, format);
   done = vfprintf (stdout, format, arg);
   va_end (arg);

   return done;
}

See here.

Here's a link to vfprintf... all the formatting 'magic' happens here.

The only thing that's truly 'different' about these functions is that they use varargs to get at arguments in a variable length argument list. Other than that, they're just traditional C. (This is in contrast to Pascal's printf equivalent, which is implemented with specific support in the compiler... at least it was back in the day.)

document .click function for touch device

To apply it everywhere, you could do something like

$('body').on('click', function() {
   if($('.children').is(':visible')) {
      $('ul.children').slideUp('slow');
   }
});

Switch/toggle div (jQuery)

You could write a simple jQuery plugin to do this. The plugin would look like:

(function($) {
    $.fn.expandcollapse = function() {
        return this.each(function() {
            obj = $(this);
            switch (obj.css("display")) {
                case "block":
                    displayValue = "none";
                    break;

                case "none":
                default:
                    displayValue = "block";
            }

            obj.css("display", displayValue);
        });
    };
} (jQuery));

Then wire the plugin up to the click event for the anchor tag:

$(document).ready(function() {
    $("#mylink").click(function() {
        $("div").expandcollapse();
    });
});

Providing that you set the initial 'display' attributes for each div to be 'block' and 'none' respectively, they should switch to being shown/hidden when the link is clicked.

how to instanceof List<MyType>?

if(!myList.isEmpty() && myList.get(0) instanceof MyType){
    // MyType object
}

Java 32-bit vs 64-bit compatibility

All byte code is 8-bit based. (That's why its called BYTE code) All the instructions are a multiple of 8-bits in size. We develop on 32-bit machines and run our servers with 64-bit JVM.

Could you give some detail of the problem you are facing? Then we might have a chance of helping you. Otherwise we would just be guessing what the problem is you are having.

Java Class.cast() vs. cast operator

It's always problematic and often misleading to try and translate constructs and concepts between languages. Casting is no exception. Particularly because Java is a dynamic language and C++ is somewhat different.

All casting in Java, no matter how you do it, is done at runtime. Type information is held at runtime. C++ is a bit more of a mix. You can cast a struct in C++ to another and it's merely a reinterpretation of the bytes that represent those structs. Java doesn't work that way.

Also generics in Java and C++ are vastly different. Don't concern yourself overly with how you do C++ things in Java. You need to learn how to do things the Java way.

What and where are the stack and heap?

The most important point is that heap and stack are generic terms for ways in which memory can be allocated. They can be implemented in many different ways, and the terms apply to the basic concepts.

  • In a stack of items, items sit one on top of the other in the order they were placed there, and you can only remove the top one (without toppling the whole thing over).

    Stack like a stack of papers

    The simplicity of a stack is that you do not need to maintain a table containing a record of each section of allocated memory; the only state information you need is a single pointer to the end of the stack. To allocate and de-allocate, you just increment and decrement that single pointer. Note: a stack can sometimes be implemented to start at the top of a section of memory and extend downwards rather than growing upwards.

  • In a heap, there is no particular order to the way items are placed. You can reach in and remove items in any order because there is no clear 'top' item.

    Heap like a heap of licorice allsorts

    Heap allocation requires maintaining a full record of what memory is allocated and what isn't, as well as some overhead maintenance to reduce fragmentation, find contiguous memory segments big enough to fit the requested size, and so on. Memory can be deallocated at any time leaving free space. Sometimes a memory allocator will perform maintenance tasks such as defragmenting memory by moving allocated memory around, or garbage collecting - identifying at runtime when memory is no longer in scope and deallocating it.

These images should do a fairly good job of describing the two ways of allocating and freeing memory in a stack and a heap. Yum!

  • To what extent are they controlled by the OS or language runtime?

    As mentioned, heap and stack are general terms, and can be implemented in many ways. Computer programs typically have a stack called a call stack which stores information relevant to the current function such as a pointer to whichever function it was called from, and any local variables. Because functions call other functions and then return, the stack grows and shrinks to hold information from the functions further down the call stack. A program doesn't really have runtime control over it; it's determined by the programming language, OS and even the system architecture.

    A heap is a general term used for any memory that is allocated dynamically and randomly; i.e. out of order. The memory is typically allocated by the OS, with the application calling API functions to do this allocation. There is a fair bit of overhead required in managing dynamically allocated memory, which is usually handled by the runtime code of the programming language or environment used.

  • What is their scope?

    The call stack is such a low level concept that it doesn't relate to 'scope' in the sense of programming. If you disassemble some code you'll see relative pointer style references to portions of the stack, but as far as a higher level language is concerned, the language imposes its own rules of scope. One important aspect of a stack, however, is that once a function returns, anything local to that function is immediately freed from the stack. That works the way you'd expect it to work given how your programming languages work. In a heap, it's also difficult to define. The scope is whatever is exposed by the OS, but your programming language probably adds its rules about what a "scope" is in your application. The processor architecture and the OS use virtual addressing, which the processor translates to physical addresses and there are page faults, etc. They keep track of what pages belong to which applications. You never really need to worry about this, though, because you just use whatever method your programming language uses to allocate and free memory, and check for errors (if the allocation/freeing fails for any reason).

  • What determines the size of each of them?

    Again, it depends on the language, compiler, operating system and architecture. A stack is usually pre-allocated, because by definition it must be contiguous memory. The language compiler or the OS determine its size. You don't store huge chunks of data on the stack, so it'll be big enough that it should never be fully used, except in cases of unwanted endless recursion (hence, "stack overflow") or other unusual programming decisions.

    A heap is a general term for anything that can be dynamically allocated. Depending on which way you look at it, it is constantly changing size. In modern processors and operating systems the exact way it works is very abstracted anyway, so you don't normally need to worry much about how it works deep down, except that (in languages where it lets you) you mustn't use memory that you haven't allocated yet or memory that you have freed.

  • What makes one faster?

    The stack is faster because all free memory is always contiguous. No list needs to be maintained of all the segments of free memory, just a single pointer to the current top of the stack. Compilers usually store this pointer in a special, fast register for this purpose. What's more, subsequent operations on a stack are usually concentrated within very nearby areas of memory, which at a very low level is good for optimization by the processor on-die caches.

How to wrap text in textview in Android

For me this issue only occurred on Android < 4.0

The combination of parameters I used were:

android:layout_weight="1"
android:ellipsize="none"
android:maxLines="100"
android:scrollHorizontally="false"

The maxLines count seemed to be the random final piece that made my TextView wrap.

Get class name using jQuery

use like this:-

$(".myclass").css("color","red");

if you've used this class more than once then use each operator

$(".myclass").each(function (index, value) {
//do you code
}

Changes in import statement python3

To support both Python 2 and Python 3, use explicit relative imports as below. They are relative to the current module. They have been supported starting from 2.5.

from .sister import foo
from . import brother
from ..aunt import bar
from .. import uncle

How to update all MySQL table rows at the same time?

The default null value for a field is "not null". So you must set it to "null" before you can set that field value for any record to null. Then you can:

UPDATE `myTable` SET `myField` = null

Interpreting segfault messages

This is a segfault due to following a null pointer trying to find code to run (that is, during an instruction fetch).

If this were a program, not a shared library

Run addr2line -e yourSegfaultingProgram 00007f9bebcca90d (and repeat for the other instruction pointer values given) to see where the error is happening. Better, get a debug-instrumented build, and reproduce the problem under a debugger such as gdb.

Since it's a shared library

You're hosed, unfortunately; it's not possible to know where the libraries were placed in memory by the dynamic linker after-the-fact. Reproduce the problem under gdb.

What the error means

Here's the breakdown of the fields:

  • address (after the at) - the location in memory the code is trying to access (it's likely that 10 and 11 are offsets from a pointer we expect to be set to a valid value but which is instead pointing to 0)
  • ip - instruction pointer, ie. where the code which is trying to do this lives
  • sp - stack pointer
  • error - An error code for page faults; see below for what this means on x86.

    /*
     * Page fault error code bits:
     *
     *   bit 0 ==    0: no page found       1: protection fault
     *   bit 1 ==    0: read access         1: write access
     *   bit 2 ==    0: kernel-mode access  1: user-mode access
     *   bit 3 ==                           1: use of reserved bit detected
     *   bit 4 ==                           1: fault was an instruction fetch
     */
    

LF will be replaced by CRLF in git - What is that and is it important?

In Unix systems the end of a line is represented with a line feed (LF). In windows a line is represented with a carriage return (CR) and a line feed (LF) thus (CRLF). when you get code from git that was uploaded from a unix system they will only have an LF.

If you are a single developer working on a windows machine, and you don't care that git automatically replaces LFs to CRLFs, you can turn this warning off by typing the following in the git command line

git config core.autocrlf true

If you want to make an intelligent decision how git should handle this, read the documentation

Here is a snippet

Formatting and Whitespace

Formatting and whitespace issues are some of the more frustrating and subtle problems that many developers encounter when collaborating, especially cross-platform. It’s very easy for patches or other collaborated work to introduce subtle whitespace changes because editors silently introduce them, and if your files ever touch a Windows system, their line endings might be replaced. Git has a few configuration options to help with these issues.

core.autocrlf

If you’re programming on Windows and working with people who are not (or vice-versa), you’ll probably run into line-ending issues at some point. This is because Windows uses both a carriage-return character and a linefeed character for newlines in its files, whereas Mac and Linux systems use only the linefeed character. This is a subtle but incredibly annoying fact of cross-platform work; many editors on Windows silently replace existing LF-style line endings with CRLF, or insert both line-ending characters when the user hits the enter key.

Git can handle this by auto-converting CRLF line endings into LF when you add a file to the index, and vice versa when it checks out code onto your filesystem. You can turn on this functionality with the core.autocrlf setting. If you’re on a Windows machine, set it to true – this converts LF endings into CRLF when you check out code:

$ git config --global core.autocrlf true

If you’re on a Linux or Mac system that uses LF line endings, then you don’t want Git to automatically convert them when you check out files; however, if a file with CRLF endings accidentally gets introduced, then you may want Git to fix it. You can tell Git to convert CRLF to LF on commit but not the other way around by setting core.autocrlf to input:

$ git config --global core.autocrlf input

This setup should leave you with CRLF endings in Windows checkouts, but LF endings on Mac and Linux systems and in the repository.

If you’re a Windows programmer doing a Windows-only project, then you can turn off this functionality, recording the carriage returns in the repository by setting the config value to false:

$ git config --global core.autocrlf false

How do I get the month and day with leading 0's in SQL? (e.g. 9 => 09)

select right('0000' + cast(datepart(year, GETDATE()) as varchar(4)), 4) + '-'+ + right('00' + cast(datepart(month, GETDATE()) as varchar(2)), 2) + '-'+ + right('00' + cast(datepart(day, getdate()) as varchar(2)), 2) as YearMonthDay

How to create websockets server in PHP

I was in the same boat as you recently, and here is what I did:

  1. I used the phpwebsockets code as a reference for how to structure the server-side code. (You seem to already be doing this, and as you noted, the code doesn't actually work for a variety of reasons.)

  2. I used PHP.net to read the details about every socket function used in the phpwebsockets code. By doing this, I was finally able to understand how the whole system works conceptually. This was a pretty big hurdle.

  3. I read the actual WebSocket draft. I had to read this thing a bunch of times before it finally started to sink in. You will likely have to go back to this document again and again throughout the process, as it is the one definitive resource with correct, up-to-date information about the WebSocket API.

  4. I coded the proper handshake procedure based on the instructions in the draft in #3. This wasn't too bad.

  5. I kept getting a bunch of garbled text sent from the clients to the server after the handshake and I couldn't figure out why until I realized that the data is encoded and must be unmasked. The following link helped me a lot here: (original link broken) Archived copy.

    Please note that the code available at this link has a number of problems and won't work properly without further modification.

  6. I then came across the following SO thread, which clearly explains how to properly encode and decode messages being sent back and forth: How can I send and receive WebSocket messages on the server side?

    This link was really helpful. I recommend consulting it while looking at the WebSocket draft. It'll help make more sense out of what the draft is saying.

  7. I was almost done at this point, but had some issues with a WebRTC app I was making using WebSocket, so I ended up asking my own question on SO, which I eventually solved: What is this data at the end of WebRTC candidate info?

  8. At this point, I pretty much had it all working. I just had to add some additional logic for handling the closing of connections, and I was done.

That process took me about two weeks total. The good news is that I understand WebSocket really well now and I was able to make my own client and server scripts from scratch that work great. Hopefully the culmination of all that information will give you enough guidance and information to code your own WebSocket PHP script.

Good luck!


Edit: This edit is a couple of years after my original answer, and while I do still have a working solution, it's not really ready for sharing. Luckily, someone else on GitHub has almost identical code to mine (but much cleaner), so I recommend using the following code for a working PHP WebSocket solution:
https://github.com/ghedipunk/PHP-Websockets/blob/master/websockets.php


Edit #2: While I still enjoy using PHP for a lot of server-side related things, I have to admit that I've really warmed up to Node.js a lot recently, and the main reason is because it's better designed from the ground up to handle WebSocket than PHP (or any other server-side language). As such, I've found recently that it's a lot easier to set up both Apache/PHP and Node.js on your server and use Node.js for running the WebSocket server and Apache/PHP for everything else. And in the case where you're on a shared hosting environment in which you can't install/use Node.js for WebSocket, you can use a free service like Heroku to set up a Node.js WebSocket server and make cross-domain requests to it from your server. Just make sure if you do that to set your WebSocket server up to be able to handle cross-origin requests.

When running UPDATE ... datetime = NOW(); will all rows updated have the same date/time?

They should have the same time, the update is supposed to be atomic, meaning that whatever how long it takes to perform, the action is supposed to occurs as if all was done at the same time.

If you're experiencing a different behaviour, it's time to change for another DBMS.

call a static method inside a class?

Let's assume this is your class:

class Test
{
    private $baz = 1;

    public function foo() { ... }

    public function bar() 
    {
        printf("baz = %d\n", $this->baz);
    }

    public static function staticMethod() { echo "static method\n"; }
}

From within the foo() method, let's look at the different options:

$this->staticMethod();

So that calls staticMethod() as an instance method, right? It does not. This is because the method is declared as public static the interpreter will call it as a static method, so it will work as expected. It could be argued that doing so makes it less obvious from the code that a static method call is taking place.

$this::staticMethod();

Since PHP 5.3 you can use $var::method() to mean <class-of-$var>::; this is quite convenient, though the above use-case is still quite unconventional. So that brings us to the most common way of calling a static method:

self::staticMethod();

Now, before you start thinking that the :: is the static call operator, let me give you another example:

self::bar();

This will print baz = 1, which means that $this->bar() and self::bar() do exactly the same thing; that's because :: is just a scope resolution operator. It's there to make parent::, self:: and static:: work and give you access to static variables; how a method is called depends on its signature and how the caller was called.

To see all of this in action, see this 3v4l.org output.

Best way to find os name and version in Unix/Linux platform

The "lsb_release" command provides certain Linux Standard Base and distribution-specific information. So using the below command we can get Operating system name and operating system version.

"lsb_release -a"

What exactly is the difference between Web API and REST API in MVC?

ASP.NET Web API is a framework that makes it easy to build HTTP services that reach a broad range of clients, including browsers and mobile devices. ASP.NET Web API is an ideal platform for building RESTful applications on the .NET Framework.

REST

RESTs sweet spot is when you are exposing a public API over the internet to handle CRUD operations on data. REST is focused on accessing named resources through a single consistent interface.

SOAP

SOAP brings it’s own protocol and focuses on exposing pieces of application logic (not data) as services. SOAP exposes operations. SOAP is focused on accessing named operations, each implement some business logic through different interfaces.

Though SOAP is commonly referred to as “web services” this is a misnomer. SOAP has very little if anything to do with the Web. REST provides true “Web services” based on URIs and HTTP.

Reference: http://spf13.com/post/soap-vs-rest

And finally: What they could be referring to is REST vs. RPC See this: http://encosia.com/rest-vs-rpc-in-asp-net-web-api-who-cares-it-does-both/

How to install Boost on Ubuntu

Actually you don't need "install" or "compile" anything before using Boost in your project. You can just download and extract the Boost library to any location on your machine, which is usually like /usr/local/.

When you compile your code, you can just indicate the compiler where to find the libraries by -I. For example, g++ -I /usr/local/boost_1_59_0 xxx.hpp.

Setting state on componentDidMount()

According to the React Documentation it's perfectly OK to call setState() from within the componentDidMount() function.

It will cause render() to be called twice, which is less efficient than only calling it once, but other than that it's perfectly fine.

You can find the documentation here:

https://reactjs.org/docs/react-component.html#componentdidmount

Here is the excerpt from the documentation:

You may call setState() immediately in componentDidMount(). It will trigger an extra rendering, but it will happen before the browser updates the screen. This guarantees that even though the render() will be called twice in this case, the user won’t see the intermediate state. Use this pattern with caution because it often causes performance issues...

dyld: Library not loaded: /usr/local/lib/libpng16.16.dylib with anything php related

I got this problem after updating MAMP, and the custom $PATH I had set was wrong because of the new php version, so the wrong version of php was loaded first, and it was that version of php that triggered the error.

Updating the path in my .bash_profile fixed my issue.

How to initialize an array's length in JavaScript?

Assuming that Array's length is constant. In Javascript, This is what we do:

const intialArray = new Array(specify the value);

How can I connect to MySQL in Python 3 on Windows?

Summary

Mysqlclient is the best alternative(IMHO) because it works flawlessly with Python 3+, follows expected conventions (unlike mysql connector), uses the object name mysqldb which enables convenient porting of existing software and is used by Django for Python 3 builds

Is there a repository available where the binaries exist for mysqldb?

Yes. mysqlclient allows you to use mysqldb functions. Though, remember this is not a direct port by mysqldb, but a build by mysqlclient

How can I connect to MySQL in Python 3 on Windows?

pip install mysqlclient

Example

#!/Python36/python
#Please change above path to suit your platform.  Am running it on Windows
import MySQLdb
db = MySQLdb.connect(user="my-username",passwd="my-password",host="localhost",db="my-databasename")
cursor = db.cursor()
cursor.execute("SELECT * from my-table-name")
data=cursor.fetchall()
for row in data :
    print (row)
db.close()

I can't find mysqldb for Python 3.

mysqldb has not been ported yet

NGINX - No input file specified. - php Fast/CGI

If someone is still having trouble with it ... I solved it by correcting it this way:

Inside the site conf file (example: /etc/nginx/conf.d/SITEEXAMPLE.conf) I have the following line:

fastcgi_param  SCRIPT_FILENAME  /usr/share/nginx/html$fastcgi_script_name;

The error occurs because my site is NOT in the "/usr/share/nginx/html" folder but in the folder: /var/www/html/SITE/

So, change that part, leaving the code as below. Note: For those who use the site standard in /var/www/html/YOUR_SITE/

fastcgi_param  SCRIPT_FILENAME  /var/www/html/YOUR_SITE/$fastcgi_script_name;

Are there any HTTP/HTTPS interception tools like Fiddler for mac OS X?

I think the possibilities are less, but FireBug (addon of FireFox) has some network analysis tools, too.

Forgot Oracle username and password, how to retrieve?

The usernames are shown in the dba_users's username column, there is a script you can run called:

alter user username identified by password

You can get more information here - https://community.oracle.com/thread/632617?tstart=0

Return JSON response from Flask view

If you want to analyze a file uploaded by the user, the Flask quickstart shows how to get files from users and access them. Get the file from request.files and pass it to the summary function.

from flask import request, jsonify
from werkzeug import secure_filename

@app.route('/summary', methods=['GET', 'POST'])
def summary():
    if request.method == 'POST':
        csv = request.files['data']
        return jsonify(
            summary=make_summary(csv),
            csv_name=secure_filename(csv.filename)
        )

    return render_template('submit_data.html')

Replace the 'data' key for request.files with the name of the file input in your HTML form.

Where does Vagrant download its .box files to?

The actual .box file is deleted by Vagrant once the download and box installation is complete. As mentioned in other answers, whilst downloading, the .box file is stored as:

~/.vagrant.d/tmp/boxXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

where the file name is 'box' followed by a 40 byte hexadecimal hash. A temporary file on my system for example, is:

~/.vagrant.d/tmp/boxc74a85fe4af3197a744851517c6af4d4959db77f

As far as I can tell, this file is never saved with a *.box extension, which explains why the searches above failed to locate it. There are two ways to retrieve the actual box file:

  1. Download the .box file from vagrantcloud.com

    1. Find the box you're interested in on the atlas. For example, https://atlas.hashicorp.com/ubuntu/boxes/trusty64/versions/20150530.0.1
    2. Replace the domain name with vagrantcloud.com. So https://atlas.hashicorp.com/ubuntu/boxes/trusty64/versions/20150530.0.1 becomes https://vagrantcloud.com/ubuntu/boxes/trusty64/versions/20150530.0.1/providers/virtualbox.box.
    3. Add /providers/virtualbox.box to the end of that URL. So https://vagrantcloud.com/ubuntu/boxes/trusty64/versions/20150530.0.1 becomes https://vagrantcloud.com/ubuntu/boxes/trusty64/versions/20150530.0.1/providers/virtualbox.box
    4. Save the .box file
    5. Use the .box as you wish, for example, hosting it yourself and pointing config.vm.box_url to the URL. OR
  2. Get the .box directly from Vagrant

    This requires you to modify the ruby source to prevent Vagrant from deleting the box after successful download.

    1. Locate the box_add.rb file in your Vagrant installation directory. On my system it's located at /Applications/Vagrant/embedded/gems/gems/vagrant-1.5.2/lib/vagrant/action/builtin/box_add.rb
    2. Find the box_add function. Within the box_add function, there is a block that reads:

      ensure # Make sure we delete the temporary file after we add it, # unless we were interrupted, in which case we keep it around # so we can resume the download later. if !@download_interrupted @logger.debug("Deleting temporary box: #{box_url}") begin box_url.delete if box_url rescue Errno::ENOENT # Not a big deal, the temp file may not actually exist end end

    3. Comment this block out.
    4. Add another box using vagrant add box <boxname>.
    5. Wait for it to download. You can watch it save in the ~/.vagrant.d/tmp/ directory as a boxXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX file.
    6. Rename the the file to something more useful. Eg, mv boxXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX trusty64.box.

Why would you want this?

For me, this has been useful to retrieve the .box file so it can be hosted on local, fast infrastructure as opposed to downloading from HashiCorp's Atlas box catalog or another box provider.

This really should be part of the default Vagrant functionality as it has a very definitive use case.

Ascending and Descending Number Order in java

Just sort the array in ascending order and print it backwards.

Arrays.sort(arr);
for(int i = arr.length-1; i >= 0 ; i--) {
    //print arr[i]
}

Extract subset of key-value pairs from Python dictionary object?

Using map (halfdanrump's answer) is best for me, though haven't timed it...

But if you go for a dictionary, and if you have a big_dict:

  1. Make absolutely certain you loop through the the req. This is crucial, and affects the running time of the algorithm (big O, theta, you name it)
  2. Write it generic enough to avoid errors if keys are not there.

so e.g.:

big_dict = {'a':1,'b':2,'c':3,................................................}
req = ['a','c','w']

{k:big_dict.get(k,None) for k in req )
# or 
{k:big_dict[k] for k in req if k in big_dict)

Note that in the converse case, that the req is big, but my_dict is small, you should loop through my_dict instead.

In general, we are doing an intersection and the complexity of the problem is O(min(len(dict)),min(len(req))). Python's own implementation of intersection considers the size of the two sets, so it seems optimal. Also, being in c and part of the core library, is probably faster than most not optimized python statements. Therefore, a solution that I would consider is:

dict = {'a':1,'b':2,'c':3,................................................}
req = ['a','c','w',...................]

{k:dic[k] for k in set(req).intersection(dict.keys())}

It moves the critical operation inside python's c code and will work for all cases.

How to change font size in html?

Or add styles inline:

<p style="font-size:18px">Paragraph 1</p>
<p style="font-size:16px">Paragraph 2</p>

JOIN queries vs multiple queries

Construct both separate queries and joins, then time each of them -- nothing helps more than real-world numbers.

Then even better -- add "EXPLAIN" to the beginning of each query. This will tell you how many subqueries MySQL is using to answer your request for data, and how many rows scanned for each query.

How can I set a custom baud rate on Linux?

For Mac users (possibly also for some Linux distributions)

stty ospeed 999999

stty ispeed 999999

Hash String via SHA-256 in Java

You don't necessarily need the BouncyCastle library. The following code shows how to do so using the Integer.toHexString function

public static String sha256(String base) {
    try{
        MessageDigest digest = MessageDigest.getInstance("SHA-256");
        byte[] hash = digest.digest(base.getBytes("UTF-8"));
        StringBuffer hexString = new StringBuffer();

        for (int i = 0; i < hash.length; i++) {
            String hex = Integer.toHexString(0xff & hash[i]);
            if(hex.length() == 1) hexString.append('0');
            hexString.append(hex);
        }

        return hexString.toString();
    } catch(Exception ex){
       throw new RuntimeException(ex);
    }
}

Special thanks to user1452273 from this post: How to hash some string with sha256 in Java?

Keep up the good work !

How to create a file with a given size in Linux?

For small files:

dd if=/dev/zero of=upload_test bs=file_size count=1

Where file_size is the size of your test file in bytes.

For big files:

dd if=/dev/zero of=upload_test bs=1M count=size_in_megabytes

nginx error "conflicting server name" ignored

There should be only one localhost defined, check sites-enabled or nginx.conf.

How to count occurrences of a column value efficiently in SQL?

and if data in "age" column has similar records (i.e. many people are 25 years old, many others are 32 and so on), it causes confusion in aligning right count to each student. in order to avoid it, I joined the tables on student ID as well.

SELECT S.id, S.age, C.cnt
FROM Students S 
INNER JOIN (SELECT id, age, count(age) as cnt  FROM Students GROUP BY student,age) 
C ON S.age = C.age *AND S.id = C.id*

setState() inside of componentDidUpdate()

If you use setState inside componentDidUpdate it updates the component, resulting in a call to componentDidUpdate which subsequently calls setState again resulting in the infinite loop. You should conditionally call setState and ensure that the condition violating the call occurs eventually e.g:

componentDidUpdate: function() {
    if (condition) {
        this.setState({..})
    } else {
        //do something else
    }
}

In case you are only updating the component by sending props to it(it is not being updated by setState, except for the case inside componentDidUpdate), you can call setState inside componentWillReceiveProps instead of componentDidUpdate.

How to convert an array to object in PHP?

i have done it with quite simple way,

    $list_years         = array();
    $object             = new stdClass();

    $object->year_id   = 1 ;
    $object->year_name = 2001 ;
    $list_years[]       = $object;

How to convert date in to yyyy-MM-dd Format?

Use this.

java.util.Date date = new Date("Sat Dec 01 00:00:00 GMT 2012");
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
String format = formatter.format(date);
System.out.println(format);

you will get the output as

2012-12-01

When is a timestamp (auto) updated?

Give the command SHOW CREATE TABLE whatever

Then look at the table definition.

It probably has a line like this

logtime TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,

in it. DEFAULT CURRENT_TIMESTAMP means that any INSERT without an explicit time stamp setting uses the current time. Likewise, ON UPDATE CURRENT_TIMESTAMP means that any update without an explicit timestamp results in an update to the current timestamp value.

You can control this default behavior when creating your table.

Or, if the timestamp column wasn't created correctly in the first place, you can change it.

ALTER TABLE whatevertable
     CHANGE whatevercolumn 
            whatevercolumn TIMESTAMP NOT NULL
                           DEFAULT CURRENT_TIMESTAMP 
                           ON UPDATE CURRENT_TIMESTAMP;

This will cause both INSERT and UPDATE operations on the table automatically to update your timestamp column. If you want to update whatevertable without changing the timestamp, that is,

To prevent the column from updating when other columns change

then you need to issue this kind of update.

UPDATE whatevertable
   SET something = 'newvalue',
       whatevercolumn = whatevercolumn
 WHERE someindex = 'indexvalue'

This works with TIMESTAMP and DATETIME columns. (Prior to MySQL version 5.6.5 it only worked with TIMESTAMPs) When you use TIMESTAMPs, time zones are accounted for: on a correctly configured server machine, those values are always stored in UTC and translated to local time upon retrieval.

What are "named tuples" in Python?

Try this:

collections.namedtuple()

Basically, namedtuples are easy to create, lightweight object types. They turn tuples into convenient containers for simple tasks. With namedtuples, you don’t have to use integer indices for accessing members of a tuple.

Examples:

Code 1:

>>> from collections import namedtuple

>>> Point = namedtuple('Point','x,y')

>>> pt1 = Point(1,2)

>>> pt2 = Point(3,4)

>>> dot_product = ( pt1.x * pt2.x ) +( pt1.y * pt2.y )

>>> print dot_product
11

Code 2:

>>> from collections import namedtuple

>>> Car = namedtuple('Car','Price Mileage Colour Class')

>>> xyz = Car(Price = 100000, Mileage = 30, Colour = 'Cyan', Class = 'Y')

>>> print xyz

Car(Price=100000, Mileage=30, Colour='Cyan', Class='Y')
>>> print xyz.Class
Y

"Automatic" vs "Automatic (Delayed start)"

In short, services set to Automatic will start during the boot process, while services set to start as Delayed will start shortly after boot.

Starting your service Delayed improves the boot performance of your server and has security benefits which are outlined in the article Adriano linked to in the comments.

Update: "shortly after boot" is actually 2 minutes after the last "automatic" service has started, by default. This can be configured by a registry key, according to Windows Internals and other sources (3,4).

The registry keys of interest (At least in some versions of windows) are:

  • HKLM\SYSTEM\CurrentControlSet\services\<service name>\DelayedAutostart will have the value 1 if delayed, 0 if not.
  • HKLM\SYSTEM\CurrentControlSet\services\AutoStartDelay or HKLM\SYSTEM\CurrentControlSet\Control\AutoStartDelay (on Windows 10): decimal number of seconds to wait, may need to create this one. Applies globally to all Delayed services.

Get time difference between two dates in seconds

Accurate and fast will give output in seconds:

 let startDate = new Date()
 let endDate = new Date("yyyy-MM-dd'T'HH:mm:ssZ");
 let seconds = Math.round((endDate.getTime() - startDate.getTime()) / 1000);

How to install Cmake C compiler and CXX compiler

The approach I use is to start the "Visual Studio Command Prompt" which can be found in the Start menu. E.g. my visual studio 2010 Express install has a shortcute Visual Studio Command Prompt (2010) at Start Menu\Programs\Microsoft Visual Studio 2010\Visual Studio Tools.

This shortcut prepares an environment by calling a script vcvarsall.bat where the compiler, linker, etc. are setup from the right Visual Studio installation.

Alternatively, if you already have a prompt open, you can prepare the environment by calling a similar script:

:: For x86 (using the VS100COMNTOOLS env-var)
call "%VS100COMNTOOLS%"\..\..\VC\bin\vcvars32.bat

or

:: For amd64 (using the full path)
call C:\Program Files\Microsoft Visual Studio 10.0\VC\bin\amd64\vcvars64.bat

However:

Your output (with the '$' prompt) suggests that you are attempting to run CMake from a MSys shell. In that case it might be better to run CMake for MSys or MinGW, by explicitly specifying a makefile generator:

cmake -G"MSYS Makefiles"
cmake -G"MinGW Makefiles"

Run cmake --help to get a list of all possible generators.

Quadratic and cubic regression in Excel

I know that this question is a little old, but I thought that I would provide an alternative which, in my opinion, might be a little easier. If you're willing to add "temporary" columns to a data set, you can use Excel's Analysis ToolPak?Data Analysis?Regression. The secret to doing a quadratic or a cubic regression analysis is defining the Input X Range:.

If you're doing a simple linear regression, all you need are 2 columns, X & Y. If you're doing a quadratic, you'll need X_1, X_2, & Y where X_1 is the x variable and X_2 is x^2; likewise, if you're doing a cubic, you'll need X_1, X_2, X_3, & Y where X_1 is the x variable, X_2 is x^2 and X_3 is x^3. Notice how the Input X Range is from A1 to B22, spanning 2 columns.

Input for Quadratic Regression Analysis in Excel

The following image the output of the regression analysis. I've highlighted the common outputs, including the R-Squared values and all the coefficients.

Coefficients of Quadratic Regression Analysis in Excel

How to set image to UIImage

may be:

UIImage *img = [[UIImage alloc] init];

and when you want to change the image:

img = [UIImage imageNamed:@"nameOfPng.png"];

but the object wasn't in the same place in the memory, but if you use the pointer, the same pointer will be point to the last image loaded.

jQuery "blinking highlight" effect on div?

Try with jquery.blink.js plugin:

https://github.com/webarthur/jquery-blink

<script src="http://code.jquery.com/ui/1.11.4/jquery-ui.js"></script>
<script src="/path/to/jquery.blink.js"></script>

<script>
jQuery('span').blink({color:'white'}, {color:'black'}, 50);
</script>

#enjoy!

Cannot import the keyfile 'blah.pfx' - error 'The keyfile may be password protected'

I had the same problem after moving my Windows installation to an SSD. None of the other solutions worked for me.

My solution was to open the project file in Notepad and remove all references to PFX keys. Once the file is saved, open the solution in Visual Studio. Go to project -> Properties -> Signing. You shouldn't see any keys listed in the 'choose the strong name key file' combo box. In the combo box, browse to the key, select it and your project can now be built.

private constructor

It's common when you want to implement a singleton. The class can have a static "factory method" that checks if the class has already been instantiated, and calls the constructor if it hasn't.

How to change value of object which is inside an array using JavaScript or jQuery?

let thismoth = moment(new Date()).format('MMMM');
months.sort(function (x, y) { return x == thismoth ? -1 : y == thismoth ? 1 : 0; });

Automatically start a Windows Service on install

In your Installer class, add a handler for the AfterInstall event. You can then call the ServiceController in the event handler to start the service.

using System.ServiceProcess;
public ServiceInstaller()
{
    //... Installer code here
    this.AfterInstall += new InstallEventHandler(ServiceInstaller_AfterInstall);
}

void ServiceInstaller_AfterInstall(object sender, InstallEventArgs e)
{
    ServiceInstaller serviceInstaller = (ServiceInstaller)sender;

    using (ServiceController sc = new ServiceController(serviceInstaller.ServiceName))
    {
             sc.Start();
    }
}

Now when you run InstallUtil on your installer, it will install and then start up the service automatically.

Reading text files using read.table

From ?read.table: The number of data columns is determined by looking at the first five lines of input (or the whole file if it has less than five lines), or from the length of col.names if it is specified and is longer. This could conceivably be wrong if fill or blank.lines.skip are true, so specify col.names if necessary.

So, perhaps your data file isn't clean. Being more specific will help the data import:

d = read.table("foobar.txt", 
               sep="\t", 
               col.names=c("id", "name"), 
               fill=FALSE, 
               strip.white=TRUE)

will specify exact columns and fill=FALSE will force a two column data frame.

Several ports (8005, 8080, 8009) required by Tomcat Server at localhost are already in use

In case of windows, I experienced a new stuff... stopping tomcat from /bin folder will immediately not releasing the port 8080. It takes around 5-10 mins to release the port. After 10 mins again if i try to run my project Run-> Run on server .. it allows to run.

I'm unsure whether my understanding is correct!

How do I write a Python dictionary to a csv file?

You are using DictWriter.writerows() which expects a list of dicts, not a dict. You want DictWriter.writerow() to write a single row.

You will also want to use DictWriter.writeheader() if you want a header for you csv file.

You also might want to check out the with statement for opening files. It's not only more pythonic and readable but handles closing for you, even when exceptions occur.

Example with these changes made:

import csv

my_dict = {"test": 1, "testing": 2}

with open('mycsvfile.csv', 'w') as f:  # You will need 'wb' mode in Python 2.x
    w = csv.DictWriter(f, my_dict.keys())
    w.writeheader()
    w.writerow(my_dict)

Which produces:

test,testing
1,2

Start a fragment via Intent within a Fragment

You cannot open new fragments. Fragments need to be always hosted by an activity. If the fragment is in the same activity (eg tabs) then the back key navigation is going to be tricky I am assuming that you want to open a new screen with that fragment.

So you would simply create a new activity and put the new fragment in there. That activity would then react to the intent either explicitly via the activity class or implicitly via intent filters.

Truncate a string straight JavaScript

Use the substring method:

var length = 3;
var myString = "ABCDEFG";
var myTruncatedString = myString.substring(0,length);
// The value of myTruncatedString is "ABC"

So in your case:

var length = 3;  // set to the number of characters you want to keep
var pathname = document.referrer;
var trimmedPathname = pathname.substring(0, Math.min(length,pathname.length));

document.getElementById("foo").innerHTML =
     "<a href='" + pathname +"'>" + trimmedPathname + "</a>"

What is a classpath and how do I set it?

Classpath is an environment variable of system. The setting of this variable is used to provide the root of any package hierarchy to java compiler.

How can I access localhost from another computer in the same network?

You need to find what your local network's IP of that computer is. Then other people can access to your site by that IP.

You can find your local network's IP by go to Command Prompt or press Windows + R then type in ipconfig. It will give out some information and your local IP should look like 192.168.1.x.

How can I print out C++ map values?

If your compiler supports (at least part of) C++11 you could do something like:

for (auto& t : myMap)
    std::cout << t.first << " " 
              << t.second.first << " " 
              << t.second.second << "\n";

For C++03 I'd use std::copy with an insertion operator instead:

typedef std::pair<string, std::pair<string, string> > T;

std::ostream &operator<<(std::ostream &os, T const &t) { 
    return os << t.first << " " << t.second.first << " " << t.second.second;
}

// ...
std:copy(myMap.begin(), myMap.end(), std::ostream_iterator<T>(std::cout, "\n"));

Compare every item to every other item in ArrayList

What's the problem with using for loop inside, just like outside?

for (int j = i + 1; j < list.size(); ++j) {
    ...
}

In general, since Java 5, I used iterators only once or twice.

Copy multiple files in Python

You can use os.listdir() to get the files in the source directory, os.path.isfile() to see if they are regular files (including symbolic links on *nix systems), and shutil.copy to do the copying.

The following code copies only the regular files from the source directory into the destination directory (I'm assuming you don't want any sub-directories copied).

import os
import shutil
src_files = os.listdir(src)
for file_name in src_files:
    full_file_name = os.path.join(src, file_name)
    if os.path.isfile(full_file_name):
        shutil.copy(full_file_name, dest)

JavaScript/jQuery - "$ is not defined- $function()" error

I have solved it as follow.

import $ from 'jquery';

(function () {
    // ... code let script = $(..)
})();

How to add elements of a string array to a string array list?

Arrays.asList is the handy function available in Java to convert an array variable to List or Collection. For better under standing consider the below example:

package com.stackoverflow.works;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class Wetland {
    private String name;
    private List<String> species = new ArrayList<String>();

    public Wetland(String name, String[] speciesArr) {
        this.name = name;
        this.species = Arrays.asList(speciesArr);
    }

    public void display() {
        System.out.println("Name: " + name);
        System.out.println("Elements in the List");
        System.out.println("********************");
        for (String string : species) {
            System.out.println(string);
        }
    }

    /*
     * @Description: Method to test your code
     */
    public static void main(String[] args) {
        String name = "Colors";
        String speciesArr[] = new String [] {"red", "blue", "green"};
        Wetland wetland = new Wetland(name, speciesArr);
        wetland.display();
    }

}

Output:

enter image description here

How to set time to midnight for current day?

Using some of the above recommendations, the following function and code is working for search a date range:

Set date with the time component set to 00:00:00

public static DateTime GetDateZeroTime(DateTime date)
{
    return new DateTime(date.Year, date.Month, date.Day, 0, 0, 0);
}

Usage

var modifieddatebegin = Tools.Utilities.GetDateZeroTime(form.modifieddatebegin);

var modifieddateend = Tools.Utilities.GetDateZeroTime(form.modifieddateend.AddDays(1));

Attach a body onload event with JS

document.body.onload is a cross-browser, but a legacy mechanism that only allows a single callback (you cannot assign multiple functions to it).

The closest "standard" alternative, addEventListener is not supported by Internet Explorer (it uses attachEvent), so you will likely want to use a library (jQuery, MooTools, prototype.js, etc.) to abstract the cross-browser ugliness for you.

How to force C# .net app to run only one instance in Windows?

This is what I use in my application:

static void Main()
{
  bool mutexCreated = false;
  System.Threading.Mutex mutex = new System.Threading.Mutex( true, @"Local\slimCODE.slimKEYS.exe", out mutexCreated );

  if( !mutexCreated )
  {
    if( MessageBox.Show(
      "slimKEYS is already running. Hotkeys cannot be shared between different instances. Are you sure you wish to run this second instance?",
      "slimKEYS already running",
      MessageBoxButtons.YesNo,
      MessageBoxIcon.Question ) != DialogResult.Yes )
    {
      mutex.Close();
      return;
    }
  }

  // The usual stuff with Application.Run()

  mutex.Close();
}

Dynamic classname inside ngClass in angular 2

Is basically duplication of the other answers - but I didn't get it completely. maybe someone will finally understand it with this example now.

[ngClass]="['svg-icon', 'recolor-' + recolor, size ? 'size-' + size : '']"

will result for e.g. in

class="svg-icon recolor-red size-m"

Bootstrap 3: Scroll bars

You need to use overflow option like below:

.nav{
    max-height: 300px;
    overflow-y: scroll; 
}

Change the height according to amount of items you need to show

How to execute powershell commands from a batch file?

This is what the code would look like in a batch file(tested, works):

powershell -Command "& {set-location 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings'; set-location ZoneMap\Domains; new-item SERVERNAME; set-location SERVERNAME; new-itemproperty . -Name http -Value 2 -Type DWORD;}"

Based on the information from:

http://dmitrysotnikov.wordpress.com/2008/06/27/powershell-script-in-a-bat-file/

How to open a file for both reading and writing?

Summarize the I/O behaviors

|          Mode          |  r   |  r+  |  w   |  w+  |  a   |  a+  |
| :--------------------: | :--: | :--: | :--: | :--: | :--: | :--: |
|          Read          |  +   |  +   |      |  +   |      |  +   |
|         Write          |      |  +   |  +   |  +   |  +   |  +   |
|         Create         |      |      |  +   |  +   |  +   |  +   |
|         Cover          |      |      |  +   |  +   |      |      |
| Point in the beginning |  +   |  +   |  +   |  +   |      |      |
|    Point in the end    |      |      |      |      |  +   |  +   |

and the decision branch

enter image description here

How to enable scrolling on website that disabled scrolling?

Select the Body using chrome dev tools (Inspect ) and change in css overflow:visible,

If that doesn't work then check in below css file if html, body is set as overflow:hidden , change it as visible

Git merge master into feature branch

You should be able to rebase your branch on master:

git checkout feature1
git rebase master

Manage all conflicts that arise. When you get to the commits with the bugfixes (already in master), Git will say that there were no changes and that maybe they were already applied. You then continue the rebase (while skipping the commits already in master) with

git rebase --skip

If you perform a git log on your feature branch, you'll see the bugfix commit appear only once, and in the master portion.

For a more detailed discussion, take a look at the Git book documentation on git rebase (https://git-scm.com/docs/git-rebase) which cover this exact use case.

================ Edit for additional context ====================

This answer was provided specifically for the question asked by @theomega, taking his particular situation into account. Note this part:

I want to prevent [...] commits on my feature branch which have no relation to the feature implementation.

Rebasing his private branch on master is exactly what will yield that result. In contrast, merging master into his branch would precisely do what he specifically does not want to happen: adding a commit that is not related to the feature implementation he is working on via his branch.

To address the users that read the question title, skip over the actual content and context of the question, and then only read the top answer blindly assuming it will always apply to their (different) use case, allow me to elaborate:

  • only rebase private branches (i.e. that only exist in your local repository and haven't been shared with others). Rebasing shared branches would "break" the copies other people may have.
  • if you want to integrate changes from a branch (whether it's master or another branch) into a branch that is public (e.g. you've pushed the branch to open a pull request, but there are now conflicts with master, and you need to update your branch to resolve those conflicts) you'll need to merge them in (e.g. with git merge master as in @Sven's answer).
  • you can also merge branches into your local private branches if that's your preference, but be aware that it will result in "foreign" commits in your branch.

Finally, if you're unhappy with the fact that this answer is not the best fit for your situation even though it was for @theomega, adding a comment below won't be particularly helpful: I don't control which answer is selected, only @theomega does.

Replace multiple strings with multiple other strings

This may not meet your exact need in this instance, but I've found this a useful way to replace multiple parameters in strings, as a general solution. It will replace all instances of the parameters, no matter how many times they are referenced:

String.prototype.fmt = function (hash) {
        var string = this, key; for (key in hash) string = string.replace(new RegExp('\\{' + key + '\\}', 'gm'), hash[key]); return string
}

You would invoke it as follows:

var person = '{title} {first} {last}'.fmt({ title: 'Agent', first: 'Jack', last: 'Bauer' });
// person = 'Agent Jack Bauer'

How to place two divs next to each other?

Option 1

Use float:left on both div elements and set a % width for both div elements with a combined total width of 100%.

Use box-sizing: border-box; on the floating div elements. The value border-box forces the padding and borders into the width and height instead of expanding it.

Use clearfix on the <div id="wrapper"> to clear the floating child elements which will make the wrapper div scale to the correct height.

.clearfix:after {
   content: " "; 
   visibility: hidden;
   display: block;
   height: 0;
   clear: both;
}

#first, #second{
  box-sizing: border-box;
  -moz-box-sizing: border-box;
  -webkit-box-sizing: border-box;
}

#wrapper {
    width: 500px;
    border: 1px solid black;
}
#first {
    border: 1px solid red;
    float:left;
    width:50%;
}
#second {
    border: 1px solid green;
    float:left;
    width:50%;
}

http://jsfiddle.net/dqC8t/3381/

Option 2

Use position:absolute on one element and a fixed width on the other element.

Add position:relative to <div id="wrapper"> element to make child elements absolutely position to the <div id="wrapper"> element.

#wrapper {
    width: 500px;
    border: 1px solid black;
    position:relative;
}
#first {
    border: 1px solid red;
    width:100px;
}
#second {
    border: 1px solid green;
    position:absolute;
    top:0;
    left:100px;
    right:0;
}

http://jsfiddle.net/dqC8t/3382/

Option 3

Use display:inline-block on both div elements and set a % width for both div elements with a combined total width of 100%.

And again (same as float:left example) use box-sizing: border-box; on the div elements. The value border-box forces the padding and borders into the width and height instead of expanding it.

NOTE: inline-block elements can have spacing issues as it is affected by spaces in HTML markup. More information here: https://css-tricks.com/fighting-the-space-between-inline-block-elements/

#first, #second{
  box-sizing: border-box;
  -moz-box-sizing: border-box;
  -webkit-box-sizing: border-box;
}

#wrapper {
    width: 500px;
    border: 1px solid black;
    position:relative;
}

#first {
    width:50%;
    border: 1px solid red;
    display:inline-block;
}

#second {
    width:50%;
    border: 1px solid green;
    display:inline-block;
}

http://jsfiddle.net/dqC8t/3383/

A final option would be to use the new display option named flex, but note that browser compatibility might come in to play:

http://caniuse.com/#feat=flexbox

http://www.sketchingwithcss.com/samplechapter/cheatsheet.html

Difference between r+ and w+ in fopen()

w+

#include <stdio.h>
int main()
{
   FILE *fp;
   fp = fopen("test.txt", "w+");  //write and read mode
   fprintf(fp, "This is testing for fprintf...\n"); 

   rewind(fp); //rewind () function moves file pointer position to the beginning of the file.
   char ch;
   while((ch=getc(fp))!=EOF)
   putchar(ch);

   fclose(fp);
}  

output

This is testing for fprintf...

test.txt

This is testing for fprintf...

w and r to form w+

#include <stdio.h>
int main()
{
   FILE *fp;

   fp = fopen("test.txt", "w"); //only write mode
   fprintf(fp, "This is testing for fprintf...\n"); 
   fclose(fp);
   fp = fopen("test.txt", "r");
   char ch;
   while((ch=getc(fp))!=EOF)
   putchar(ch);
   fclose(fp);
}  

output

This is testing for fprintf...

test.txt

This is testing for fprintf...

r+

test.txt

This is testing for fprintf...
#include<stdio.h>
int main()
{
    FILE *fp;
    fp = fopen("test.txt", "r+");  //read and write mode
    char ch;
    while((ch=getc(fp))!=EOF)
    putchar(ch);
    rewind(fp); //rewind () function moves file pointer position to the beginning of the file.
    fprintf(fp, "This is testing for fprintf again...\n");
    fclose(fp);
    return 0;
}

output

This is testing for fprintf...

test.txt

This is testing for fprintf again...

r and w to form r+

test.txt

This is testing for fprintf...
#include<stdio.h>
int main()
{
    FILE *fp;
    fp = fopen("test.txt", "r"); 
    char ch;
    while((ch=getc(fp))!=EOF)
    putchar(ch);
    fclose(fp);

    fp=fopen("test.txt","w");
    fprintf(fp, "This is testing for fprintf again...\n");
    fclose(fp);
    return 0;
}

output

This is testing for fprintf...

test.txt

This is testing for fprintf again...

a+

test.txt

This is testing for fprintf...
#include<stdio.h>
int main()
{
    FILE *fp;
    fp = fopen("test.txt", "a+");  //append and read mode
    char ch;
    while((ch=getc(fp))!=EOF)
    putchar(ch);
    rewind(fp); //rewind () function moves file pointer position to the beginning of the file.
    fprintf(fp, "This is testing for fprintf again...\n");
    fclose(fp);
    return 0;
}

output

This is testing for fprintf...

test.txt

This is testing for fprintf...
This is testing for fprintf again...

a and r to form a+

test.txt

This is testing for fprintf...
#include<stdio.h>
int main()
{
    FILE *fp;
    fp = fopen("test.txt", "a");  //append and read mode
    char ch;
    while((ch=getc(fp))!=EOF)
    putchar(ch);
    fclose(fp);
    fp=fopen("test.txt","r");
    fprintf(fp, "This is testing for fprintf again...\n");
    fclose(fp);
    return 0;
}

output

This is testing for fprintf...

test.txt

This is testing for fprintf...
This is testing for fprintf again...

Converting double to integer in Java

is there a possibility that casting a double created via Math.round() will still result in a truncated down number

No, round() will always round your double to the correct value, and then, it will be cast to an long which will truncate any decimal places. But after rounding, there will not be any fractional parts remaining.

Here are the docs from Math.round(double):

Returns the closest long to the argument. The result is rounded to an integer by adding 1/2, taking the floor of the result, and casting the result to type long. In other words, the result is equal to the value of the expression:

(long)Math.floor(a + 0.5d)

Dividing two integers to produce a float result

Cast the operands to floats:

float ans = (float)a / (float)b;

How do I set log4j level on the command line?

These answers actually dissuaded me from trying the simplest possible thing! Simply specify a threshold for an appender (say, "console") in your log4j.configuration like so:

log4j.appender.console.threshold=${my.logging.threshold}

Then, on the command line, include the system property -Dlog4j.info -Dmy.logging.threshold=INFO. I assume that any other property can be parameterized in this way, but this is the easiest way to raise or lower the logging level globally.

OpenSSL: PEM routines:PEM_read_bio:no start line:pem_lib.c:703:Expecting: TRUSTED CERTIFICATE

My mistake was simply using the CSR file instead of the CERT file.

How to add include and lib paths to configure/make cycle?

You want a config.site file. Try:

$ mkdir -p ~/local/share
$ cat << EOF > ~/local/share/config.site
CPPFLAGS=-I$HOME/local/include
LDFLAGS=-L$HOME/local/lib
...
EOF

Whenever you invoke an autoconf generated configure script with --prefix=$HOME/local, the config.site will be read and all the assignments will be made for you. CPPFLAGS and LDFLAGS should be all you need, but you can make any other desired assignments as well (hence the ... in the sample above). Note that -I flags belong in CPPFLAGS and not in CFLAGS, as -I is intended for the pre-processor and not the compiler.

Understanding the ngRepeat 'track by' expression

You can track by $index if your data source has duplicate identifiers

e.g.: $scope.dataSource: [{id:1,name:'one'}, {id:1,name:'one too'}, {id:2,name:'two'}]

You can't iterate this collection while using 'id' as identifier (duplicate id:1).

WON'T WORK:

<element ng-repeat="item.id as item.name for item in dataSource">
  // something with item ...
</element>

but you can, if using track by $index:

<element ng-repeat="item in dataSource track by $index">
  // something with item ...
</element>

How to create javascript delay function

You do not need to use an anonymous function with setTimeout. You can do something like this:

setTimeout(doSomething, 3000);

function doSomething() {
   //do whatever you want here
}

Batch file to copy files from one folder to another folder

@echo off

rem The * at the end of the destination file is to avoid File/Directory Internal Question.

rem You can do this for each especific file. (Make sure you already have permissions to the path)
xcopy /Y "\\Oldeserver\storage\data\MyFile01.txt" "\\New server\storage\data\MyFile01.txt"*
pause

rem You can use "copy" instead of "xcopy "for this example.

Generating a Random Number between 1 and 10 Java

This will work for generating a number 1 - 10. Make sure you import Random at the top of your code.

import java.util.Random;

If you want to test it out try something like this.

Random rn = new Random();

for(int i =0; i < 100; i++)
{
    int answer = rn.nextInt(10) + 1;
    System.out.println(answer);
}

Also if you change the number in parenthesis it will create a random number from 0 to that number -1 (unless you add one of course like you have then it will be from 1 to the number you've entered).

Import CSV file into SQL Server

I know that there are accepted answer but still, I want to share my scenario that maybe help someone to solve their problem TOOLS

  • ASP.NET
  • EF CODE-FIRST APPROACH
  • SSMS
  • EXCEL

SCENARIO i was loading the dataset which's in CSV format which was later to be shown on the View i tried to use the bulk load but I's unable to load as BULK LOAD was using

FIELDTERMINATOR = ','

and Excel cell was also using , however, I also couldn't use Flat file source directly because I was using Code-First Approach and doing that only made model in SSMS DB, not in the model from which I had to use the properties later.

SOLUTION

  1. I used flat-file source and made DB table from CSV file (Right click DB in SSMS -> Import Flat FIle -> select CSV path and do all the settings as directed)
  2. Made Model Class in Visual Studio (You MUST KEEP all the datatypes and names same as that of CSV file loaded in sql)
  3. use Add-Migration in NuGet package console
  4. Update DB

How do I access my SSH public key?

Copy the key to your clipboard.

$ pbcopy < ~/.ssh/id_rsa.pub
# Copies the contents of the id_rsa.pub file to your clipboard

Warning: it's important to copy the key exactly without adding newlines or whitespace. Thankfully the pbcopy command makes it easy to perform this setup perfectly.

and paste it wherever you need.

More details on the process, check: Generating SSH Keys.

To draw an Underline below the TextView in Android

For anyone still looking at this querstion. This is for a hyperlink but you can modify it for just a plain underline:

Create a drawable (hyperlink_underline.xml):

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:top="-10dp"
        android:left="-10dp"
        android:right="-10dp">
    <shape android:shape="rectangle">
      <solid android:color="@android:color/transparent"/>

      <stroke android:width="2dp"
              android:color="#3498db"/>
    </shape>
  </item>
</layer-list>

Create a new style:

<style name="Hyperlink">
    <item name="android:textColor">#3498db</item>
    <item name="android:background">@drawable/hyperlink_underline</item>
  </style>

Then use this style on your TextView:

<TextView
    android:layout_height="wrap_content"
    android:layout_width="wrap_content"
    local:MvxBind="Text Id; Click ShowJobInfoCommand"
    style="@style/HyperLink"/>

What's the best practice for primary keys in tables?

GUIDs can be used as a primary key, but you need to create the right type of GUID so that it performs well.

You need to generate COMB GUIDs. A good article about it and performance statistics is The Cost of GUIDs as Primary Keys.

Also some code on building COMB GUIDs in SQL is in Uniqueidentifier vs identity(archive).

How do I make the text box bigger in HTML/CSS?

If you want to make them a lot bigger, like for multiple lines of input, you may want to use a textarea tag instead of the input tag. This allows you to put in number of rows and columns you want on your textarea without messing with css (e.g. <textarea rows="2" cols="25"></textarea>).

Text areas are resizable by default. If you want to disable that, just use the resize css rule:

#signin textarea {
    resize: none;
}

A simple solution to your question about default text that disappears when the user clicks is to use the placeholder attribute. This will work for <input> tags as well.

<textarea rows="2" cols="25" placeholder="This is the default text"></textarea>

This text will disappear when the user enters information rather than when they click, but that is common functionality for this kind of thing.

How can I set a UITableView to grouped style

If you are inheriting UITableViewController, you can just init tableView again.

Objective C:

self.tableView = [[UITableView alloc] initWithFrame:CGRectZero style:UITableViewStyleGrouped];

Swift:

self.tableView = UITableView(frame: CGRect.zero, style: .grouped)

How to set height property for SPAN

this is to make display:inline-block work in all browsers:

Quirkly enough, in IE (6/7) , if you trigger hasLayout with "zoom:1" and then set the display to inline, it behaves as an inline block.

.inline-block {
    display: inline-block;
    zoom: 1;
    *display: inline;
}

Filter by Dates in SQL

Well you are trying to compare Date with Nvarchar which is wrong. Should be

Where dates between date1 And date2
-- both date1 & date2 should be date/datetime

If date1,date2 strings; server will convert them to date type before filtering.

SQL query, if value is null then return 1

You can use a CASE statement.

SELECT 
    CASE WHEN currate.currentrate IS NULL THEN 1 ELSE currate.currentrate END
FROM ...