Programs & Examples On #Bzr svn

what's the easiest way to put space between 2 side-by-side buttons in

Try putting the following class on your second button

    margin-left: 20px;


If you want your first button to be spaced from the div as well as from the second button, then apply this class to your first button also.

Getting the docstring from a function

Interactively, you can display it with


Or from code you can retrieve it with


How can I expose more than 1 port with Docker?

if you use docker-compose.ymlfile:

            - 80
            - 6081

You can also specify the host/network port as HOST/NETWORK_PORT:CONTAINER_PORT

        - 81:80
        - 6081:6081

Non greedy (reluctant) regex matching in sed?

@Daniel H (concerning your comment on andcoz' answer, although long time ago): deleting trailing zeros works with


it's about clearly defining the matching conditions ...

Typescript: No index signature with a parameter of type 'string' was found on type '{ "A": string; }

You have two options with simple and idiomatic Typescript:

  1. Use index type
DNATranscriber: { [char: string]: string } = {
  G: "C",
  C: "G",
  T: "A",
  A: "U",

This is the index signature the error message is talking about. Reference

  1. Type each property:
DNATranscriber: { G: string; C: string; T: string; A: string } = {
  G: "C",
  C: "G",
  T: "A",
  A: "U",

angularjs: allows only numbers to be typed into a text box

Simply use HTML5

<input type="number" min="0"/>

How to run vi on docker container?

The command to run depends on what base image you are using.

For Alpine, vi is installed as part of the base OS. Installing vim would be:

apk -U add vim

For Debian and Ubuntu:

apt-get update && apt-get install -y vim

For CentOS, vi is usually installed with the base OS. For vim:

yum install -y vim

This should only be done in early development. Once you get a working container, the changes to files should be made to your image or configs stored outside of your container. Update your Dockerfile and other files it uses to build a new image. This certainly shouldn't be done in production since changes inside the container are by design ephemeral and will be lost when the container is replaced.

500 internal server error, how to debug

Try writing all the errors to a file.

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

Something like that.

javac is not recognized as an internal or external command, operable program or batch file

Run the following from the command prompt: set Path="C:\Program Files\Java\jdk1.7.0_09\bin" or set PATH="C:\Program Files\Java\jdk1.7.0_09\bin"

I have tried this and it works well.

How to sort in mongoose?

Mongoose v5.x.x

sort by ascending order

Post.find({}).sort('field').exec(function(err, docs) { ... });
Post.find({}).sort({ field: 'asc' }).exec(function(err, docs) { ... });
Post.find({}).sort({ field: 'ascending' }).exec(function(err, docs) { ... });
Post.find({}).sort({ field: 1 }).exec(function(err, docs) { ... });

Post.find({}, null, {sort: { field : 'asc' }}), function(err, docs) { ... });
Post.find({}, null, {sort: { field : 'ascending' }}), function(err, docs) { ... });
Post.find({}, null, {sort: { field : 1 }}), function(err, docs) { ... });

sort by descending order

Post.find({}).sort('-field').exec(function(err, docs) { ... });
Post.find({}).sort({ field: 'desc' }).exec(function(err, docs) { ... });
Post.find({}).sort({ field: 'descending' }).exec(function(err, docs) { ... });
Post.find({}).sort({ field: -1 }).exec(function(err, docs) { ... });

Post.find({}, null, {sort: { field : 'desc' }}), function(err, docs) { ... });
Post.find({}, null, {sort: { field : 'descending' }}), function(err, docs) { ... });
Post.find({}, null, {sort: { field : -1 }}), function(err, docs) { ... });

For Details:

How to find out client ID of component for ajax update/render? Cannot find component with expression "foo" referenced from "bar"

I know this already has a great answer by BalusC but here is a little trick I use to get the container to tell me the correct clientId.

  1. Remove the update on your component that is not working
  2. Put a temporary component with a bogus update within the component you were trying to update
  3. hit the page, the servlet exception error will tell you the correct client Id you need to reference.
  4. Remove bogus component and put correct clientId in the original update

Here is code example as my words may not describe it best.

<p:tabView id="tabs">
    <p:tab id="search" title="Search">                        
        <h:form id="insTable">
            <p:dataTable id="table" var="lndInstrument" value="#{instrumentBean.instruments}">
                    <p:commandLink id="select"

Remove the failing update within this component

                        <f:setPropertyActionListener value="#{lndInstrument}" 
                                        target="#{instrumentBean.selectedInstrument}" />
                        <h:outputText value="#{}" />
            <p:dialog id="dlg" modal="true" widgetVar="dlg">
                <h:panelGrid id="display">

Add a component within the component of the id you are trying to update using an update that will fail

   <p:commandButton id="BogusButton" update="BogusUpdate"></p:commandButton>

                    <h:outputText value="Name:" />
                    <h:outputText value="#{}" />

Hit this page and view the error. The error is: javax.servlet.ServletException: Cannot find component for expression "BogusUpdate" referenced from tabs:insTable: BogusButton

So the correct clientId to use would then be the bold plus the id of the target container (display in this case)


only integers, slices (`:`), ellipsis (`...`), numpy.newaxis (`None`) and integer or boolean arrays are valid indices

I believe your problem is this: in your while loop, n is divided by 2, but never cast as an integer again, so it becomes a float at some point. It is then added onto y, which is then a float too, and that gives you the warning.

Query grants for a table in postgres

If you really want one line per user, you can group by grantee (require PG9+ for string_agg)

SELECT grantee, string_agg(privilege_type, ', ') AS privileges
FROM information_schema.role_table_grants 
WHERE table_name='mytable'   
GROUP BY grantee;

This should output something like :

 grantee |   privileges   
 user1   | INSERT, SELECT
 user2   | UPDATE
(2 rows)

Installing SetupTools on 64-bit Windows

Problem: you have 64-bit Python, and a 32-bit installer. This will cause problems for extension modules.

The reasons why the installer doesn't finds Python is the transparent 32-bit emulation from Windows 7. 64-bit and 32-bit programs will write to different parts of the Windows registry.


32-bit: HKLM|HKCU\SOFTWARE\wow6432node\.

This means that the 64-bit Python installer writes to HKLM\SOFTWARE\Python, but the 32-bit setuptools installer looks at HKLM\SOFTWARE\wow6432node\Python (this is handled by windows automatically, programs don't notice). This is expected behavior and not a bug.

Usually, you have these choices:

  • the "clean" way: use 32-bit Python if you have to use 32-bit modules or extensions
  • the other "clean" way: only use 64-bit installers when using 64-bit Python (see below)
  • what the answer above suggests: copy HKLM\SOFTWARE\Python to HKLM\SOFTWARE\wow6432node\Python, but this will cause problems with binary distributions, as 64-bit Python can't load 32-bit compiled modules (do NOT do this!)
  • install pure Python modules with setuptools instead of the distutils installer (easy_install or pip)

For setuptools itself, for example, you can't use a 32-bit installer for 64-bit Python as it includes binary files. But there's a 64-bit installer at (has many installers for other modules too). Nowadays, many packages on PyPi have binary distributions, so you can install them via pip.

Seeing the underlying SQL in the Spring JdbcTemplate?

I use this line for Spring Boot applications: = TRACE

This approach pretty universal and I usually use it for any other classes inside my application.

How do you change video src using jQuery?


<script type="text/javascript">_x000D_
$(document).ready(function() {_x000D_
  var videoID = 'videoclip';_x000D_
  var sourceID = 'mp4video';_x000D_
  var newmp4 = 'media/video2.mp4';_x000D_
  var newposter = 'media/video-poster2.jpg';_x000D_
  $('#videolink1').click(function(event) {_x000D_
    $('#'+sourceID).attr('src', newmp4);_x000D_
     //$('#'+videoID).attr('poster', newposter); //Change video poster_x000D_

Calculate RSA key fingerprint

Run the following command to retrieve the SHA256 fingerprint of your SSH key (-l means "list" instead of create a new key, -f means "filename"):

$ ssh-keygen -lf /path/to/ssh/key

So for example, on my machine the command I ran was (using RSA public key):

$ ssh-keygen -lf ~/.ssh/
2048 00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:ff /Users/username/.ssh/ (RSA)

To get the GitHub (MD5) fingerprint format with newer versions of ssh-keygen, run:

$ ssh-keygen -E md5 -lf <fileName>

Bonus information:

ssh-keygen -lf also works on known_hosts and authorized_keys files.

To find most public keys on Linux/Unix/OS X systems, run

$ find /etc/ssh /home/*/.ssh /Users/*/.ssh -name '*.pub' -o -name 'authorized_keys' -o -name 'known_hosts'

(If you want to see inside other users' homedirs, you'll have to be root or sudo.)

The ssh-add -l is very similar, but lists the fingerprints of keys added to your agent. (OS X users take note that magic passwordless SSH via Keychain is not the same as using ssh-agent.)

How to iterate over a JavaScript object?

<script type="text/javascript">
// method 1
var images = {};
images['name'] = {};
images['family'] = {};
images[1] = {};
images['name'][5] = "Mehdi";
images['family'][8] = "Mohammadpour";
images['family']['ok'] = 123456;
images[1][22] = 2602;
images[1][22] = 2602;
images[1][22] = 2602;
images[1][22] = 2602;
images[1][23] = 2602;

for (const [key1, value1] of Object.entries(images)){
    for (const [key2, value2] of Object.entries(value1)){
        console.log(`${key1} => ${key2}: ${value2}`);


// method 2
var arr = [];
for(var x = 0; x < 5; x++){
     arr[x] = [];    
     for(var y = 0; y < 5; y++){ 
         arr[x][y] = x*y;    

for(var i = 0; i < arr.length; i++) {
    var cube = arr[i];
    for(var j = 0; j < cube.length; j++) {
        console.log("cube[" + i + "][" + j + "] = " + cube[j]);


How to prevent SIGPIPEs (or handle them properly)

I'm super late to the party, but SO_NOSIGPIPE isn't portable, and might not work on your system (it seems to be a BSD thing).

A nice alternative if you're on, say, a Linux system without SO_NOSIGPIPE would be to set the MSG_NOSIGNAL flag on your send(2) call.

Example replacing write(...) by send(...,MSG_NOSIGNAL) (see nobar's comment)

char buf[888];
//write( sockfd, buf, sizeof(buf) );
send(    sockfd, buf, sizeof(buf), MSG_NOSIGNAL );

How to get the absolute path to the public_html folder?

You just need to create an offset bypass to how far you want the backwards reading to go. So, we use getcwd() to get the path and explode (split into array) to fetch the data between $root and the ending of the path.

function getRoot($root = "public_html") {
    return explode($root, getcwd())[0].$root."/";

How can I create a keystore?

Create keystore file from command line :

  1. Open Command line:

    Microsoft Windows [Version 6.1.7601]
    Copyright (c) 2009 Microsoft Corporation.  All rights reserved
    // (if you want to store keystore file at C:/ open command line with RUN AS ADMINISTRATOR)
    C:\Windows\system32> keytool -genkey -v -keystore [your keystore file path]{C:/index.keystore} -alias [your_alias_name]{index} -keyalg RSA -keysize 2048 -validity 10000[in days]
  2. Enter > It will prompt you for password > enter password (it will be invisible)

    Enter keystore password:
    Re-enter new password:
  3. Enter > It will ask your detail.

    What is your first and last name?
     [Unknown]:  {AB} // [Your Name / Name of Signer] 
    What is the name of your organizational unit?
     [Unknown]:  {Self} // [Your Unit Name] 
    What is the name of your organization?
     [Unknown]:  {Self} // [Your Organization Name] 
    What is the name of your City or Locality?
     [Unknown]:  {INDORE} // [Your City Name] 
    What is the name of your State or Province?
     [Unknown]:  {MP} //[Your State] 
    What is the two-letter country code for this unit?
     [Unknown]:  91
  4. Enter > Enter Y

    Is CN=AB, OU=Self, O=Self, L=INDORE, ST=MP, C=91 correct?
    [no]:  Y
  5. Enter > Enter password again.

    Generating 2,048 bit RSA key pair and self-signed certificate    (SHA256withRSA) with a validity of 10,000 days
        for: CN=AB, OU=Self, O=Self, L=INDORE, ST=MP, C=91
    Enter key password for <index> (RETURN if same as keystore password):
    Re-enter new password:

[ Storing C:/index.keystore ]

  1. And your are DONE!!!

Export In Eclipse :

Export your android package to .apk with your created keystore file

  1. Right click on Package you want to export and select export enter image description here

  2. Select Export Android Application > Next enter image description here

  3. Next
    enter image description here

  4. Select Use Existing Keystore > Browse .keystore file > enter password > Next enter image description here

  5. Select Alias > enter password > Next enter image description here

  6. Browse APK Destination > Finish enter image description here

In Android Studio:

Create keystore [.keystore/.jks] in studio...

  1. Click Build (ALT+B) > Generate Signed APK...
    enter image description here

  2. Click Create new..(ALT+C)
    enter image description here

  3. Browse Key store path (SHIFT+ENTER) > Select Path > Enter name > OK enter image description here

  4. Fill the detail about your .jks/keystore file enter image description here

  5. Next
    enter image description here

  6. Your file
    enter image description here

  7. Enter Studio Master Password (You can RESET if you don't know) > OK enter image description here

  8. Select *Destination Folder * > Build Type

    release : for publish on app store
    debug : for debugging your application

    Click Finish

    enter image description here

Done !!!

Getting value from JQUERY datepicker

If your selected elements are not one, you need use this way:

$('[type="date"]').change(function() {
    var date = $(this).datepicker("getDate");

how to customize `show processlist` in mysql?

Another useful tool for this from the command line interface, is the pager command.


pager grep -v Sleep | more; show full processlist;

Then you can page through the results.

You can also look for certain users, IPs or queries with grep or sed in this way.

The pager command is persistent per session.

How to change FontSize By JavaScript? = "25px";

use this

How to set proper codeigniter base url?

$config['base_url'] = "http://".$_SERVER['SERVER_NAME']."/project_name/";

this way you config you base_url , then won't worry about in hosting. both works in localhost and server.

Difference between xcopy and robocopy

Its painful to hear people are still suffering at the hands of *{COPY} whatever the version. I am a seasoned batch and Bash script writer and I recommend rsync , you can run this within cygwin ( or you can locate some binaries floating around . and you can redirect output to 2>&1 to some log file like out.log for later analysing. Good luck people its time to love life again . =M. Kaan=

Importing images from a directory (Python) to list or dictionary

I'd start by using glob:

from PIL import Image
import glob
image_list = []
for filename in glob.glob('yourpath/*.gif'): #assuming gif

then do what you need to do with your list of images (image_list).

Adding integers to an int array

To add an element to an array you need to use the format:

array[index] = element;

Where array is the array you declared, index is the position where the element will be stored, and element is the item you want to store in the array.

In your code, you'd want to do something like this:

int[] num = new int[args.length];
for (int i = 0; i < args.length; i++) {
    int neki = Integer.parseInt(args[i]);
    num[i] = neki;

The add() method is available for Collections like List and Set. You could use it if you were using an ArrayList (see the documentation), for example:

List<Integer> num = new ArrayList<>();
for (String s : args) {
    int neki = Integer.parseInt(s);

jQuery validate Uncaught TypeError: Cannot read property 'nodeName' of null

I found this answer when I was getting a similar error for nodeName after upgrading to Bootstrap 4. The issue was that the tabs didn't have the nav and nav-tab classes; adding those to the <ul> element fixed the issue.

How can I enable cURL for an installed Ubuntu LAMP stack?

For those who are trying to install php-curl on PHP 7, it will result in an error. Actually if you are installing php-curl in PHP 7, the package name should be;

sudo apt-get install php-curl

Not php5-curl or php7-curl, just php-curl.

Generate war file from tomcat webapp folder

There is a way to create war file of your project from eclipse.

First a create an xml file with the following code,

Replace HistoryCheck with your project name.

<?xml version="1.0" encoding="UTF-8"?>
<project name="HistoryCheck" basedir="." default="default">
    <target name="default" depends="buildwar,deploy"></target>
    <target name="buildwar">
        <war basedir="war" destfile="HistoryCheck.war" webxml="war/WEB-INF/web.xml">
            <exclude name="WEB-INF/**" />
            <webinf dir="war/WEB-INF/">
                <include name="**/*.jar" />
    <target name="deploy">
        <copy file="HistoryCheck.war" todir="." />

Now, In project explorer right click on that xml file and Run as-> ant build

You can see the war file of your project in your project folder.

Handling data in a PHP JSON Object

You mean something like this?


$jsonurl = "";
$json = file_get_contents($jsonurl,0,null,null);
$json_output = json_decode($json);

foreach ( $json_output->trends as $trend )
    echo "{$trend->name}\n";

Heatmap in matplotlib with pcolor?

This is late, but here is my python implementation of the flowingdata NBA heatmap.

updated:1/4/2014: thanks everyone

# -*- coding: utf-8 -*-
# <nbformat>3.0</nbformat>

# ------------------------------------------------------------------------
# Filename   :
# Date       : 2013-04-19
# Updated    : 2014-01-04
# Author     : @LotzJoe >> Joe Lotz
# Description: My attempt at reproducing the FlowingData graphic in Python
# Source     :
# Other Links:
# ------------------------------------------------------------------------

import matplotlib.pyplot as plt
import pandas as pd
from urllib2 import urlopen
import numpy as np
%pylab inline

page = urlopen("")
nba = pd.read_csv(page, index_col=0)

# Normalize data columns
nba_norm = (nba - nba.mean()) / (nba.max() - nba.min())

# Sort data according to Points, lowest to highest
# This was just a design choice made by Yau
# inplace=False (default) ->thanks SO user d1337
nba_sort = nba_norm.sort('PTS', ascending=True)


# Plot it out
fig, ax = plt.subplots()
heatmap = ax.pcolor(nba_sort,, alpha=0.8)

# Format
fig = plt.gcf()
fig.set_size_inches(8, 11)

# turn off the frame

# put the major ticks at the middle of each cell
ax.set_yticks(np.arange(nba_sort.shape[0]) + 0.5, minor=False)
ax.set_xticks(np.arange(nba_sort.shape[1]) + 0.5, minor=False)

# want a more natural, table-like display

# Set the labels

# label source:
labels = [
    'Games', 'Minutes', 'Points', 'Field goals made', 'Field goal attempts', 'Field goal percentage', 'Free throws made', 'Free throws attempts', 'Free throws percentage',
    'Three-pointers made', 'Three-point attempt', 'Three-point percentage', 'Offensive rebounds', 'Defensive rebounds', 'Total rebounds', 'Assists', 'Steals', 'Blocks', 'Turnover', 'Personal foul']

# note I could have used nba_sort.columns but made "labels" instead
ax.set_xticklabels(labels, minor=False)
ax.set_yticklabels(nba_sort.index, minor=False)

# rotate the


# Turn off all the ticks
ax = plt.gca()

for t in ax.xaxis.get_major_ticks():
    t.tick1On = False
    t.tick2On = False
for t in ax.yaxis.get_major_ticks():
    t.tick1On = False
    t.tick2On = False

The output looks like this: flowingdata-like nba heatmap

There's an ipython notebook with all this code here. I've learned a lot from 'overflow so hopefully someone will find this useful.


The canonical T-SQL (SqlServer) answer is to use a DELETE with JOIN as such

FROM Orders o
INNER JOIN Customers c
    ON o.CustomerId = c.CustomerId
WHERE c.FirstName = 'sklivvz'

This will delete all orders which have a customer with first name Sklivvz.

Converting a String to Object

String extends Object, which means an Object. Object o = a; If you really want to get as Object, you may do like below.

String s = "Hi";

Object a =s;


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

   SELECT FIRST_DAY(CURDATE()) INTO @checkweekday;
   SELECT DAY(@checkweekday) INTO @checkday;
   SET @daycount = 0;
   SET @workdays = 0;

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

Just for others:

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

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

Run the query. This will create a stored procedure or stored routine named test2. Now go to the routines tab and edit the stored procedure to be what you want. I also suggest reading if you are beginning with stored procedures.

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

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

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

Then use the following code in the SQL Query Window.

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

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

100% Min Height CSS layout

kleolb02's answer looks pretty good. another way would be a combination of the sticky footer and the min-height hack

How can get the text of a div tag using only javascript (no jQuery)

Actually you dont need to call document.getElementById() function to get access to your div.

You can use this object directly by id:

text = test.textContent || test.innerText;

What is the difference between a var and val definition in Scala?

It's as simple as it name.

var means it can vary

val means invariable

Updates were rejected because the tip of your current branch is behind its remote counterpart

You must have added new files in your commits which has not been pushed. Check the file and push that file again and the try pull / push it will work. This worked for me..

Single Line Nested For Loops

You might be interested in itertools.product, which returns an iterable yielding tuples of values from all the iterables you pass it. That is, itertools.product(A, B) yields all values of the form (a, b), where the a values come from A and the b values come from B. For example:

import itertools

A = [50, 60, 70]
B = [0.1, 0.2, 0.3, 0.4]

print [a + b for a, b in itertools.product(A, B)]

This prints:

[50.1, 50.2, 50.3, 50.4, 60.1, 60.2, 60.3, 60.4, 70.1, 70.2, 70.3, 70.4]

Notice how the final argument passed to itertools.product is the "inner" one. Generally, itertools.product(a0, a1, ... an) is equal to [(i0, i1, ... in) for in in an for in-1 in an-1 ... for i0 in a0]

WPF popup window

In WPF there is a control named Popup.

Popup myPopup = new Popup();
myPopup.IsOpen = true;

Android - Back button in the title bar

If you are using the new support library for 5.1 in android studio, you can instead use this on your AppCompatActivity

 ActionBar actionBar = getSupportActionBar();


css ellipsis on second line

I used these css properties for line ellipsis-

overflow: hidden;
text-overflow: ellipsis;
display: -webkit-box;
-webkit-line-clamp: 3; 
-webkit-box-orient: vertical;

here -webkit-line-clamp: 3; is the number of line(3 lines) after which ... shows.

adding multiple entries to a HashMap at once in one statement

You can use the Double Brace Initialization as shown below:

Map<String, Integer> hashMap = new HashMap<String, Integer>()
     put("One", 1);
     put("Two", 2);
     put("Three", 3);

As a piece of warning, please refer to the thread Efficiency of Java “Double Brace Initialization" for the performance implications that it might have.

What is the use of the JavaScript 'bind' method?

From the MDN docs on Function.prototype.bind() :

The bind() method creates a new function that, when called, has its this keyword set to the provided value, with a given sequence of arguments preceding any provided when the new function is called.

So, what does that mean?!

Well, let's take a function that looks like this :

var logProp = function(prop) {

Now, let's take an object that looks like this :

var Obj = {
    x : 5,
    y : 10

We can bind our function to our object like this :

Obj.log = logProp.bind(Obj);

Now, we can run Obj.log anywhere in our code :

Obj.log('x'); // Output : 5
Obj.log('y'); // Output : 10

This works, because we bound the value of this to our object Obj.

Where it really gets interesting, is when you not only bind a value for this, but also for its argument prop :

Obj.logX = logProp.bind(Obj, 'x');
Obj.logY = logProp.bind(Obj, 'y');

We can now do this :

Obj.logX(); // Output : 5
Obj.logY(); // Output : 10

Unlike with Obj.log, we do not have to pass x or y, because we passed those values when we did our binding.

How to kill a child process after a given timeout in Bash?

# Spawn a child process:
(dosmth) & pid=$!
# in the background, sleep for 10 secs then kill that process
(sleep 10 && kill -9 $pid) &

or to get the exit codes as well:

# Spawn a child process:
(dosmth) & pid=$!
# in the background, sleep for 10 secs then kill that process
(sleep 10 && kill -9 $pid) & waiter=$!
# wait on our worker process and return the exitcode
exitcode=$(wait $pid && echo $?)
# kill the waiter subshell, if it still runs
kill -9 $waiter 2>/dev/null
# 0 if we killed the waiter, cause that means the process finished before the waiter

Error in if/while (condition) {: missing Value where TRUE/FALSE needed

this works with "NA" not for NA

comments = c("no","yes","NA")
  for (l in 1:length(comments)) {
    #if (![l])) print(comments[l])
    if (comments[l] != "NA") print(comments[l])

Django development IDE

I use Kate as well. Kate's simplicity is its biggest feature. It doesn't get in your way. (This is of course highly subjective opinion.)

Kate includes a Python code browser plugin. But it isn't useful IMO. No automatic updates when you change the code/view. Also when you update, the whole tree is collapsed, and you have to expand it again yourself. Too many clicks.

Instead, I use the Source Browser plugin that comes with Pâté. It does cause Kate to freeze temporarily sometimes, but no crashes or anything of that sort so far.

Shameless blog plug: more on using Django with Kate (Pâté)

Cannot checkout, file is unmerged

status tell you what to do.

Unmerged paths:
  (use "git reset HEAD <file>..." to unstage)
  (use "git add <file>..." to mark resolution)

you probably applied a stash or something else that cause a conflict.

either add, reset, or rm.

VBA Subscript out of range - error 9

Subscript out of Range error occurs when you try to reference an Index for a collection that is invalid.

Most likely, the index in Windows does not actually include .xls. The index for the window should be the same as the name of the workbook displayed in the title bar of Excel.

As a guess, I would try using this:

Windows("Data Sheet - " & ComboBox_Month.Value & " " & TextBox_Year.Value).Activate

Spring Hibernate - Could not obtain transaction-synchronized Session for current thread

Check your dao class. It must be like this:

Session session = getCurrentSession();
Query query = session.createQuery(GET_ALL);

And annotations:


Ruby: Can I write multi-line string with no concatenation?

Recently with the new features in Ruby 2.3 the new squiggly HEREDOC will let you write our multiline strings in a nice manner with a minimal change so using this combined with the .squish (if you are using rails) will let you write multiline in a nice way! in case of just using ruby, you can do a <<~SQL.split.join(" ") which is almost the same

[1] pry(main)> <<~SQL.squish
[1] pry(main)*   select attr1, attr2, attr3, attr4, attr5, attr6, attr7
[1] pry(main)*   from table1, table2, table3, etc, etc, etc, etc, etc,
[1] pry(main)*   where etc etc etc etc etc etc etc etc etc etc etc etc etc
[1] pry(main)* SQL
=> "select attr1, attr2, attr3, attr4, attr5, attr6, attr7 from table1, table2, table3, etc, etc, etc, etc, etc, where etc etc etc etc etc etc etc etc etc etc etc etc etc"


port 8080 is already in use and no process using 8080 has been listed

If no other process is using the port 8080, Eventhough eclipse shows the port 8080 is used while starting the server in eclipse, first you have to stop the server by hitting the stop button in "Configure Tomcat"(which you can find in your start menu under tomcat folder), then try to start the server in eclipse then it will be started.

If any other process is using the port 8080 and as well as you no need to disturb it. then you can change the port.

Changing Fonts Size in Matlab Plots

If anyone was wondering how to change the font sizes without messing around with the Matlab default fonts, and change every font in a figure, I found this thread where suggests this:

set(findall(fig, '-property', 'FontSize'), 'FontSize', 10, 'fontWeight', 'bold')

findall is a pretty handy command and in the case above it really finds all the children who have a 'FontSize' property: axes lables, axes titles, pushbuttons, etc.

Hope it helps.

what is the size of an enum type data in C++?

With my now ageing Borland C++ Builder compiler enums can be 1,2 or 4 bytes, although it does have a flag you can flip to force it to use ints.

I guess it's compiler specific.

JQuery confirm dialog

Have you tried using the official JQueryUI implementation (not jQuery only) : ?

Redirect stderr and stdout in Bash

In situations when you consider using things like exec 2>&1 I find easier to read if possible rewriting code using bash functions like this:

function myfunc(){

myfunc &>mylog.log

Posting a File and Associated Data to a RESTful WebService preferably as JSON

Please ensure that you have following import. Ofcourse other standard imports


    void uploadzipFiles(String token) {

        RestBuilder rest = new RestBuilder(connectTimeout:10000, readTimeout:20000)

        def zipFile = new File("")
        def Id = "001G00000"
        MultiValueMap<String, String> form = new LinkedMultiValueMap<String, String>()
        form.add("id", id)
        form.add('file',new FileSystemResource(zipFile))
        def urld ='''http://URL''';
        def resp = {
            header('X-Auth-Token', clientSecret)
            contentType "multipart/form-data"
        println "resp::"+resp
        println "resp::"+resp.text
        println "resp::"+resp.headers
        println "resp::"+resp.body
        println "resp::"+resp.status

How to enter in a Docker container already running with a new TTY

You should use Jérôme Petazzoni's tool called 'nsenter' to enter a container without using SSH. See:

Install with simply running: docker run -v /usr/local/bin:/target jpetazzo/nsenter

Then use the command docker-enter <container-id> to enter the container.

Adding onClick event dynamically using jQuery

try this approach if you know your object client name ( it is not important that it is Button or TextBox )

$('#ButtonName').attr('onClick', 'FunctionName(this);');

try this ones if you want add onClick event to a server object with JQuery

$('#' + '<%= ButtonName.ClientID %>').removeAttr('onclick');
$('#' + '<%= ButtonName.ClientID %>').attr('onClick', 'FunctionName(this);');

Redirect pages in JSP?

    String redirectURL = "";

How to generate UML diagrams (especially sequence diagrams) from Java code?

I found Green plugin very simple to use and to generate class diagram from source code. Give it a try :). Just copy the plugin to your plugin dir.

Css Move element from left to right animated

It's because you aren't giving the un-hovered state a right attribute.

right isn't set so it's trying to go from nothing to 0px. Obviously because it has nothing to go to, it just 'warps' over.

If you give the unhovered state a right:90%;, it will transition how you like.

Just as a side note, if you still want it to be on the very left of the page, you can use the calc css function.


right: calc(100% - 100px)
                     ^ width of div

You don't have to use left then.

Also, you can't transition using left or right auto and will give the same 'warp' effect.

div {_x000D_
    right:calc(100% - 100px);_x000D_
div:hover {_x000D_
  <b>Note:</b> This example does not work in Internet Explorer 9 and earlier versions._x000D_
<p>Hover over the red square to see the transition effect.</p>

CanIUse says that the calc() function only works on IE10+

deleting folder from java

I wrote a method for this sometime back. It deletes the specified directory and returns true if the directory deletion was successful.

 * Delets a dir recursively deleting anything inside it.
 * @param dir The dir to delete
 * @return true if the dir was successfully deleted
public static boolean deleteDirectory(File dir) {
    if(! dir.exists() || !dir.isDirectory())    {
        return false;

    String[] files = dir.list();
    for(int i = 0, len = files.length; i < len; i++)    {
        File f = new File(dir, files[i]);
        if(f.isDirectory()) {
        }else   {
    return dir.delete();

Cannot uninstall angular-cli

While uninstalling Angular CLI I got the same message (as it had some permission issues):

Unable to delete .Staging folder

I tried deleting the .staging folder manually, but still got the same error. I logged in from my administrator account and tried deleting the staging folder again manually, but to no avail.

I tried this (run as Administrator):

npm uninstall -g @angular/cli
npm cache verify
npm install -g @angular/cli.

Then I tried creating the project from my normal user account and it worked.

What is difference between @RequestBody and @RequestParam?

@RequestParam annotation tells Spring that it should map a request parameter from the GET/POST request to your method argument. For example:



endpoint code:

public User getUser(@RequestParam(value = "name") String name, 
                    @RequestParam(value = "surname") String surname){ 

So basically, while @RequestBody maps entire user request (even for POST) to a String variable, @RequestParam does so with one (or more - but it is more complicated) request param to your method argument.

Check if input value is empty and display an alert

Better one is here.

    if( !$('#myMessage').val() ) {

And you don't necessarily need .length or see if its >0 since an empty string evaluates to false anyway but if you'd like to for readability purposes:

    if( $('#myMessage').val().length === 0 ) {

If you're sure it will always operate on a textfield element then you can just use this.value.

      if( !document.getElementById('myMessage').value ) {

Also you should take note that $('input:text') grabs multiple elements, specify a context or use the this keyword if you just want a reference to a lone element ( provided theres one textfield in the context's descendants/children ).

Vue v-on:click does not work on component

I think the $emit function works better for what I think you're asking for. It keeps your component separated from the Vue instance so that it is reusable in many contexts.

// Child component
  <div id="app">
    <test @click="$emit('test-click')"></test>

Use it in HTML

// Parent component
<test @test-click="testFunction">

How to get the last row of an Oracle a table

You can do it like this:

SELECT * FROM (SELECT your_table.your_field, versions_starttime
               FROM your_table


SELECT your_field,ora_rowscn,scn_to_timestamp(ora_rowscn) from your_table WHERE ROWNUM = 1;

How do you set the title color for the new Toolbar?

If you can use appcompat-v7 app:titleTextColor="#fff">


How to run (not only install) an android application using .apk file?

First to install your app:

adb install -r path\ProjectName.apk

The great thing about the -r is it works even if it wasn’t already installed.

To launch MainActivity, so you can launch it like:

adb shell am start -n com.other.ProjectName/.MainActivity

How can I use an ES6 import in Node.js?

Back to Jonathan002's original question about

"... what version supports the new ES6 import statements?"

based on the article by Dr. Axel Rauschmayer, there is a plan to have it supported by default (without the experimental command line flag) in Node.js 10.x LTS. According to node.js's release plan as it is on 3/29, 2018, it's likely to become available after Apr 2018, while LTS of it will begin on October 2018.

onclick go full screen

so simple try this

<div dir="ltr" style="text-align: left;" trbidi="on">_x000D_
<!-- begin snippet: js hide: false console: true babel: null -->

Git merge error "commit is not possible because you have unmerged files"

I've had a similar issue which boiled down to removing files under "unmerged paths"

Those files had to be removed using git rm

Constructing pandas DataFrame from values in variables gives "ValueError: If using all scalar values, you must pass an index"

Change your 'a' and 'b' values to a list, as follows:

a = [2]
b = [3]

then execute the same code as follows:

df2 = pd.DataFrame({'A':a,'B':b})

and you'll get:

    A   B
0   2   3

Multidimensional Lists in C#

Please show more of your code.

If that last piece of code declares and initializes the list variable outside the loop you're basically reusing the same list object, thus adding everything into one list.

Also show where .Capacity and .Count comes into play, how did you get those values?

How to generate a QR Code for an Android application?

zxing does not (only) provide a web API; really, that is Google providing the API, from source code that was later open-sourced in the project.

As Rob says here you can use the Java source code for the QR code encoder to create a raw barcode and then render it as a Bitmap.

I can offer an easier way still. You can call Barcode Scanner by Intent to encode a barcode. You need just a few lines of code, and two classes from the project, under android-integration. The main one is IntentIntegrator. Just call shareText().

Capturing TAB key in text box

In Chrome on the Mac, alt-tab inserts a tab character into a <textarea> field.

Here’s one: . Wee!

What method in the String class returns only the first N characters?

public static string TruncateLongString(this string str, int maxLength)
    if (string.IsNullOrEmpty(str)) return str;

    return str.Substring(0, Math.Min(str.Length, maxLength));

Copy file remotely with PowerShell

Just in case that the remote file needs your credential to get accessed, you can generate a System.Net.WebClient object using cmdlet New-Object to "Copy File Remotely", like so

$Source = "\\192.168.x.x\somefile.txt"
$Dest   = "C:\Users\user\somefile.txt"
$Username = "username"
$Password = "password"

$WebClient = New-Object System.Net.WebClient
$WebClient.Credentials = New-Object System.Net.NetworkCredential($Username, $Password)

$WebClient.DownloadFile($Source, $Dest)

Or if you need to upload a file, you can use UploadFile:

$Dest = "\\192.168.x.x\somefile.txt"
$Source   = "C:\Users\user\somefile.txt"

$WebClient.UploadFile($Dest, $Source)

How to decode viewstate

Here is the source code for a ViewState visualizer from Scott Mitchell's article on ViewState (25 pages)

using System;
using System.Collections;
using System.Text;
using System.IO;
using System.Web.UI;

namespace ViewStateArticle.ExtendedPageClasses
    /// <summary>
    /// Parses the view state, constructing a viaully-accessible object graph.
    /// </summary>
    public class ViewStateParser
        // private member variables
        private TextWriter tw;
        private string indentString = "   ";

        #region Constructor
        /// <summary>
        /// Creates a new ViewStateParser instance, specifying the TextWriter to emit the output to.
        /// </summary>
        public ViewStateParser(TextWriter writer)
            tw = writer;

        #region Methods
        #region ParseViewStateGraph Methods
        /// <summary>
        /// Emits a readable version of the view state to the TextWriter passed into the object's constructor.
        /// </summary>
        /// <param name="viewState">The view state object to start parsing at.</param>
        public virtual void ParseViewStateGraph(object viewState)
            ParseViewStateGraph(viewState, 0, string.Empty);    

        /// <summary>
        /// Emits a readable version of the view state to the TextWriter passed into the object's constructor.
        /// </summary>
        /// <param name="viewStateAsString">A base-64 encoded representation of the view state to parse.</param>
        public virtual void ParseViewStateGraph(string viewStateAsString)
            // First, deserialize the string into a Triplet
            LosFormatter los = new LosFormatter();
            object viewState = los.Deserialize(viewStateAsString);

            ParseViewStateGraph(viewState, 0, string.Empty);    

        /// <summary>
        /// Recursively parses the view state.
        /// </summary>
        /// <param name="node">The current view state node.</param>
        /// <param name="depth">The "depth" of the view state tree.</param>
        /// <param name="label">A label to display in the emitted output next to the current node.</param>
        protected virtual void ParseViewStateGraph(object node, int depth, string label)

            if (node == null)
                tw.Write(String.Concat(Indent(depth), label, "NODE IS NULL"));
            else if (node is Triplet)
                tw.Write(String.Concat(Indent(depth), label, "TRIPLET"));
                ParseViewStateGraph(((Triplet) node).First, depth+1, "First: ");
                ParseViewStateGraph(((Triplet) node).Second, depth+1, "Second: ");
                ParseViewStateGraph(((Triplet) node).Third, depth+1, "Third: ");
            else if (node is Pair)
                tw.Write(String.Concat(Indent(depth), label, "PAIR"));
                ParseViewStateGraph(((Pair) node).First, depth+1, "First: ");
                ParseViewStateGraph(((Pair) node).Second, depth+1, "Second: ");
            else if (node is ArrayList)
                tw.Write(String.Concat(Indent(depth), label, "ARRAYLIST"));

                // display array values
                for (int i = 0; i < ((ArrayList) node).Count; i++)
                    ParseViewStateGraph(((ArrayList) node)[i], depth+1, String.Format("({0}) ", i));
            else if (node.GetType().IsArray)
                tw.Write(String.Concat(Indent(depth), label, "ARRAY "));
                tw.Write(String.Concat("(", node.GetType().ToString(), ")"));
                IEnumerator e = ((Array) node).GetEnumerator();
                int count = 0;
                while (e.MoveNext())
                    ParseViewStateGraph(e.Current, depth+1, String.Format("({0}) ", count++));
            else if (node.GetType().IsPrimitive || node is string)
                tw.Write(String.Concat(Indent(depth), label));
                tw.Write(node.ToString() + " (" + node.GetType().ToString() + ")");
                tw.Write(String.Concat(Indent(depth), label, "OTHER - "));

        /// <summary>
        /// Returns a string containing the <see cref="IndentString"/> property value a specified number of times.
        /// </summary>
        /// <param name="depth">The number of times to repeat the <see cref="IndentString"/> property.</param>
        /// <returns>A string containing the <see cref="IndentString"/> property value a specified number of times.</returns>
        protected virtual string Indent(int depth)
            StringBuilder sb = new StringBuilder(IndentString.Length * depth);
            for (int i = 0; i < depth; i++)

            return sb.ToString();

        #region Properties
        /// <summary>
        /// Specifies the indentation to use for each level when displaying the object graph.
        /// </summary>
        /// <value>A string value; the default is three blank spaces.</value>
        public string IndentString
                return indentString;
                indentString = value;

And here's a simple page to read the viewstate from a textbox and graph it using the above code

private void btnParse_Click(object sender, System.EventArgs e)
            // parse the viewState
            StringWriter writer = new StringWriter();
            ViewStateParser p = new ViewStateParser(writer);

            ltlViewState.Text = writer.ToString();

Append to the end of a Char array in C++

If you are not allowed to use C++'s string class (which is terrible teaching C++ imho), a raw, safe array version would look something like this.

#include <cstring>
#include <iostream>

int main()
    char array1[] ="The dog jumps ";
    char array2[] = "over the log";
    char * newArray = new char[std::strlen(array1)+std::strlen(array2)+1];
    std::cout << newArray << std::endl;
    delete [] newArray;
    return 0;

This assures you have enough space in the array you're doing the concatenation to, without assuming some predefined MAX_SIZE. The only requirement is that your strings are null-terminated, which is usually the case unless you're doing some weird fixed-size string hacking.

Edit, a safe version with the "enough buffer space" assumption:

#include <cstring>
#include <iostream>

int main()
    const unsigned BUFFER_SIZE = 50;
    char array1[BUFFER_SIZE];
    std::strncpy(array1, "The dog jumps ", BUFFER_SIZE-1); //-1 for null-termination
    char array2[] = "over the log";
    std::strncat(array1,array2,BUFFER_SIZE-strlen(array1)-1); //-1 for null-termination
    std::cout << array1 << std::endl;
    return 0;

vbscript output to console

This was found on Dragon-IT Scripts and Code Repository.

You can do this with the following and stay away from the cscript/wscript differences and allows you to get the same console output that a batch file would have. This can help if your calling VBS from a batch file and need to make it look seamless.

Set fso = CreateObject ("Scripting.FileSystemObject")
Set stdout = fso.GetStandardStream (1)
Set stderr = fso.GetStandardStream (2)
stdout.WriteLine "This will go to standard output."
stderr.WriteLine "This will go to error output."

Eclipse projects not showing up after placing project files in workspace/projects

For Juno: (With Source in E:\workspace and destination in C:\workspace)

  1. Copy project directory in its entirety to the workspace directory. (e.g. Copy E:\workspace\HelloWorld C:\workspace\helloWorld)

  2. Start Eclipse.

  3. Perform: File --> Import

  4. Select: General -- > "Existing Project into Workspace"

  5. "Next >"

  6. Check "Select root Directory"

  7. Select with "Browse Button"

  8. Select "C:\workspace"

  9. A list of existing projects will appear. Just check the ones that are in Bold (To Be Imported) then press the "Finish" button.

Review the Package Explorer and your copied projects should now be there.

How to echo with different colors in the Windows command line

Setting color to the log statements in powershell is not a big deal friend. you can use -ForegroundColor parameter.

To write a confirmation message.

Write-Host "Process executed Successfully...." -ForegroundColor Magenta

To write an error message.

Write-Host "Sorry an unexpected error occurred.." -ForegroundColor Red

To write a progress message.

Write-Host "Working under pocess..." -ForegroundColor Green

How to pass variable number of arguments to a PHP function

I'm surprised nobody here has mentioned simply passing and extracting an array. E.g:

function add($arr){
    extract($arr, EXTR_REFS);
    return $one+$two;
$one = 1;
$two = 2;
echo add(compact('one', 'two')); // 3

Of course, this does not provide argument validation. For that, anyone can use my expect function:

The maximum message size quota for incoming messages (65536) has been exceeded

As per this question's answer

You will want something like this:

         <binding name="basicHttp" allowCookies="true"
             <readerQuotas maxDepth="32"
     </basicHttpBinding> </bindings>

Please also read comments to the accepted answer there, those contain valuable input.

What does %~dp0 mean, and how does it work?

%~dp0 expands to current directory path of the running batch file.

To get clear understanding, let's create a batch file in a directory.


with contents:

@echo off
echo %~dp0

When you run it from command prompt, you will see this result:


Selecting rows where remainder (modulo) is 1 after division by 2?

MySQL, SQL Server, PostgreSQL, SQLite support using the percent sign as the modulus:

WHERE column % 2 = 1

For Oracle, you have to use the MOD function:

WHERE MOD(column, 2) = 1

C++ Redefinition Header Files (winsock2.h)

#include guards are the standard way of doing this. #pragma once is not, meaning that not all compilers support it.

Fastest way to flatten / un-flatten nested JSON objects

Here's another approach that runs slower (about 1000ms) than the above answer, but has an interesting idea :-)

Instead of iterating through each property chain, it just picks the last property and uses a look-up-table for the rest to store the intermediate results. This look-up-table will be iterated until there are no property chains left and all values reside on uncocatenated properties.

JSON.unflatten = function(data) {
    "use strict";
    if (Object(data) !== data || Array.isArray(data))
        return data;
    var regex = /\.?([^.\[\]]+)$|\[(\d+)\]$/,
        props = Object.keys(data),
        result, p;
    while(p = props.shift()) {
        var m = regex.exec(p),
        if (m.index) {
            var rest = p.slice(0, m.index);
            if (!(rest in data)) {
                data[rest] = m[2] ? [] : {};
            target = data[rest];
        } else {
            target = result || (result = (m[2] ? [] : {}));
        target[m[2] || m[1]] = data[p];
    return result;

It currently uses the data input parameter for the table, and puts lots of properties on it - a non-destructive version should be possible as well. Maybe a clever lastIndexOf usage performs better than the regex (depends on the regex engine).

See it in action here.

Bind class toggle to window scroll event

Why do you all suggest heavy scope operations? I don't see why this is not an "angular" solution:

.directive('changeClassOnScroll', function ($window) {
  return {
    restrict: 'A',
    scope: {
        offset: "@",
        scrollClass: "@"
    link: function(scope, element) {
        angular.element($window).bind("scroll", function() {
            if (this.pageYOffset >= parseInt(scope.offset)) {
            } else {

So you can use it like this:

<navbar change-class-on-scroll offset="500" scroll-class="you-have-scrolled-down"></navbar>


<div change-class-on-scroll offset="500" scroll-class="you-have-scrolled-down"></div>

How do I protect Python code?

"Is there a good way to handle this problem?" No. Nothing can be protected against reverse engineering. Even the firmware on DVD machines has been reverse engineered and the AACS Encryption key exposed. And that's in spite of the DMCA making that a criminal offense.

Since no technical method can stop your customers from reading your code, you have to apply ordinary commercial methods.

  1. Licenses. Contracts. Terms and Conditions. This still works even when people can read the code. Note that some of your Python-based components may require that you pay fees before you sell software using those components. Also, some open-source licenses prohibit you from concealing the source or origins of that component.

  2. Offer significant value. If your stuff is so good -- at a price that is hard to refuse -- there's no incentive to waste time and money reverse engineering anything. Reverse engineering is expensive. Make your product slightly less expensive.

  3. Offer upgrades and enhancements that make any reverse engineering a bad idea. When the next release breaks their reverse engineering, there's no point. This can be carried to absurd extremes, but you should offer new features that make the next release more valuable than reverse engineering.

  4. Offer customization at rates so attractive that they'd rather pay you to build and support the enhancements.

  5. Use a license key which expires. This is cruel, and will give you a bad reputation, but it certainly makes your software stop working.

  6. Offer it as a web service. SaaS involves no downloads to customers.

How to use Simple Ajax Beginform in MVC 4?

Besides the previous post instructions, I had to install the package Microsoft.jQuery.Unobtrusive.Ajax and add to the view the following line

<script src="@Url.Content("~/Scripts/jquery.unobtrusive-ajax.js")" type="text/javascript"></script>

SQL Server Express 2008 Install Side-by-side w/ SQL 2005 Express Fails

Just Remove the the Workstation Components from Add/Remove Programs - SQL Server 2005. Removing Workstation Components, SQL Server 2008 installation goes well.

Difference between DOMContentLoaded and load events

  • domContentLoaded: marks the point when both the DOM is ready and there are no stylesheets that are blocking JavaScript execution - meaning we can now (potentially) construct the render tree. Many JavaScript frameworks wait for this event before they start executing their own logic. For this reason the browser captures the EventStart and EventEnd timestamps to allow us to track how long this execution took.

  • loadEvent: as a final step in every page load the browser fires an “onload” event which can trigger additional application logic.


Getting View's coordinates relative to the root layout

Please use view.getLocationOnScreen(int[] location); (see Javadocs). The answer is in the integer array (x = location[0] and y = location[1]).

How to get a parent element to appear above child

Set a negative z-index for the child, and remove the one set on the parent.

.parent {_x000D_
    position: relative;_x000D_
    width: 350px;_x000D_
    height: 150px;_x000D_
    background: red;_x000D_
    border: solid 1px #000;_x000D_
.parent2 {_x000D_
    position: relative;_x000D_
    width: 350px;_x000D_
    height: 40px;_x000D_
    background: red;_x000D_
    border: solid 1px #000;_x000D_
.child {_x000D_
    position: relative;_x000D_
    background-color: blue;_x000D_
    height: 200px;_x000D_
.wrapper {_x000D_
    position: relative;_x000D_
    background: green;_x000D_
    height: 350px;_x000D_
<div class="wrapper">_x000D_
    <div class="parent">parent 1 parent 1_x000D_
        <div class="child">child child child</div>_x000D_
    <div class="parent2">parent 2 parent 2_x000D_

How to define unidirectional OneToMany relationship in JPA

My bible for JPA work is the Java Persistence wikibook. It has a section on unidirectional OneToMany which explains how to do this with a @JoinColumn annotation. In your case, i think you would want:

private Set<Text> text;

I've used a Set rather than a List, because the data itself is not ordered.

The above is using a defaulted referencedColumnName, unlike the example in the wikibook. If that doesn't work, try an explicit one:

@JoinColumn(name="TXTHEAD_CODE", referencedColumnName="DATREG_META_CODE")
private Set<Text> text;

How can I select an element with multiple classes in jQuery?

The problem you're having, is that you are using a Group Selector, whereas you should be using a Multiples selector! To be more specific, you're using $('.a, .b') whereas you should be using $('.a.b').

For more information, see the overview of the different ways to combine selectors herebelow!

Group Selector : ","

Select all <h1> elements AND all <p> elements AND all <a> elements :

$('h1, p, a')

Multiples selector : "" (no character)

Select all <input> elements of type text, with classes code and red :


Descendant Selector : " " (space)

Select all <i> elements inside <p> elements:

$('p i')

Child Selector : ">"

Select all <ul> elements that are immediate children of a <li> element:

$('li > ul')

Adjacent Sibling Selector : "+"

Select all <a> elements that are placed immediately after <h2> elements:

$('h2 + a')

General Sibling Selector : "~"

Select all <span> elements that are siblings of <div> elements:

$('div ~ span')

How to recover closed output window in netbeans?

If you run the server in normal mode you can recover the log by restarting the main project in debug mode. It seems that NB opens a new server log when the server run mode changes.

How to read a value from the Windows registry

#include <windows.h>
#include <map>
#include <string>
#include <stdio.h>
#include <string.h>
#include <tr1/stdint.h>

using namespace std;

void printerr(DWORD dwerror) {
    LPVOID lpMsgBuf;
        (LPTSTR) &lpMsgBuf,
    // Process any inserts in lpMsgBuf.
    // ...
    // Display the string.
    if (isOut) {
        fprintf(fout, "%s\n", lpMsgBuf);
    } else {
        printf("%s\n", lpMsgBuf);
    // Free the buffer.

bool regreadSZ(string& hkey, string& subkey, string& value, string& returnvalue, string& regValueType) {
    char s[128000];
    map<string,HKEY> keys;
    HKEY mykey;

    map<string,DWORD> valuetypes;
    valuetypes["REG_MULTI_SZ"]=REG_MULTI_SZ; //probably can't use this.

    LONG retval=RegOpenKeyEx(
        keys[hkey],         // handle to open key
        subkey.c_str(),  // subkey name
        0,   // reserved
        KEY_READ, // security access mask
        &mykey    // handle to open key
    if (ERROR_SUCCESS != retval) {printerr(retval); return false;}
    DWORD slen=128000;
    DWORD valuetype = valuetypes[regValueType];
      mykey,            // handle to key
      value.c_str(),  // value name
      NULL,   // reserved
      (LPDWORD) &valuetype,       // type buffer
      (LPBYTE)s,        // data buffer
      (LPDWORD) &slen      // size of data buffer
    switch(retval) {
        case ERROR_SUCCESS:
            //if (isOut) {
            //    fprintf(fout,"RegQueryValueEx():ERROR_SUCCESS:succeeded.\n");
            //} else {
            //    printf("RegQueryValueEx():ERROR_SUCCESS:succeeded.\n");
        case ERROR_MORE_DATA:
            //what do I do now?  data buffer is too small.
            if (isOut) {
                fprintf(fout,"RegQueryValueEx():ERROR_MORE_DATA: need bigger buffer.\n");
            } else {
                printf("RegQueryValueEx():ERROR_MORE_DATA: need bigger buffer.\n");
            return false;
        case ERROR_FILE_NOT_FOUND:
            if (isOut) {
                fprintf(fout,"RegQueryValueEx():ERROR_FILE_NOT_FOUND: registry value does not exist.\n");
            } else {
                printf("RegQueryValueEx():ERROR_FILE_NOT_FOUND: registry value does not exist.\n");
            return false;
            if (isOut) {
                fprintf(fout,"RegQueryValueEx():unknown error type 0x%lx.\n", retval);
            } else {
                printf("RegQueryValueEx():unknown error type 0x%lx.\n", retval);
            return false;

    if (ERROR_SUCCESS != retval) {printerr(retval); return false;}

    returnvalue = s;
    return true;

Sass - Converting Hex to RGBa for background opacity

If you need to mix colour from variable and alpha transparency, and with solutions that include rgba() function you get an error like

      background-color: rgba(#{$color}, 0.3);
      $color: #002366 is not a color.
   ¦       background-color: rgba(#{$color}, 0.3);
   ¦                         ^^^^^^^^^^^^^^^^^^^^

Something like this might be useful.

$meeting-room-colors: (
  Neumann: '#002366',
  Turing: '#FF0000',
  Lovelace: '#00BFFF',
  Shared: '#00FF00',
  Chilling: '#FF1493',
$color-alpha: EE;

@each $name, $color in $meeting-room-colors {

  .#{$name} {

     background-color: #{$color}#{$color-alpha};



How to remove MySQL root password

I have also been through this problem,

First i tried setting my password of root to blank using command :

SET PASSWORD FOR root@localhost=PASSWORD('');

But don't be happy , PHPMYADMIN uses not localhost , i know you would say both are same but that is not the case , use the command mentioned underneath and you are done.

SET PASSWORD FOR [email protected]=PASSWORD('');

Just replace localhost with and you are done .

Entity Framework - Code First - Can't Store List<String>

You can use this ScalarCollection container that confines an array and provides some manipulation options (Gist):


public class Person
    public int Id { get; set; }
    //will be stored in database as single string.
    public SaclarStringCollection Phones { get; set; } = new ScalarStringCollection();


using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;

namespace System.Collections.Specialized
#if NET462
  public abstract class ScalarCollectionBase<T> :
#if NET462
    public virtual string Separator { get; } = "\n";
    public virtual string ReplacementChar { get; } = " ";
    public ScalarCollectionBase(params T[] values)
      if (values != null)
        foreach (var item in Items)

#if NET462
    [Obsolete("Not to be used directly by user, use Items property instead.")]
    public string Data
        var data = Items.Select(item => Serialize(item)
          .Replace(Separator, ReplacementChar.ToString()));
        return string.Join(Separator, data.Where(s => s?.Length > 0));
        if (string.IsNullOrWhiteSpace(value))

        foreach (var item in value
            .Split(new[] { Separator }, 
              StringSplitOptions.RemoveEmptyEntries).Select(item => Deserialize(item)))

    public void AddRange(params T[] items)
      if (items != null)
        foreach (var item in items)

    protected abstract string Serialize(T item);
    protected abstract T Deserialize(string item);

  public class ScalarStringCollection : ScalarCollectionBase<string>
    protected override string Deserialize(string item) => item;
    protected override string Serialize(string item) => item;

  public class ScalarCollection<T> : ScalarCollectionBase<T>
    where T : IConvertible
    protected override T Deserialize(string item) =>
      (T)Convert.ChangeType(item, typeof(T));
    protected override string Serialize(T item) => Convert.ToString(item);

jQuery checkbox checked state changed event

Just another solution

$('.checkbox_class').on('change', function(){ // on change of state
   if(this.checked) // if changed state is "CHECKED"
        // do the magic here

Check if ADODB connection is open

This topic is old but if other people like me search a solution, this is a solution that I have found:

Public Function DBStats() As Boolean
    On Error GoTo errorHandler
        If Not IsNull(myBase.Version) Then 
            DBStats = True
        End If
        Exit Function
        DBStats = False  
End Function

So "myBase" is a Database Object, I have made a class to access to database (class with insert, update etc...) and on the module the class is use declare in an object (obviously) and I can test the connection with "[the Object].DBStats":

Dim BaseAccess As New myClass
BaseAccess.DBOpen 'I open connection
Debug.Print BaseAccess.DBStats ' I test and that tell me true
BaseAccess.DBClose ' I close the connection
Debug.Print BaseAccess.DBStats ' I test and tell me false

Edit : In DBOpen I use "OpenDatabase" and in DBClose I use ".Close" and "set myBase = nothing" Edit 2: In the function, if you are not connect, .version give you an error so if aren't connect, the errorHandler give you false

How to deploy a React App on Apache web server

Ultimately was able to figure it out , i just hope it will help someone like me.
Following is how the web pack config file should look like check the dist dir and output file specified. I was missing the way to specify the path of dist directory

const webpack = require('webpack');
const path = require('path');
var config = {
    entry: './main.js',

    output: {
        path: path.join(__dirname, '/dist'),
        filename: 'index.js',

    devServer: {
        inline: true,
        port: 8080
    resolveLoader: {
        modules: [path.join(__dirname, 'node_modules')]
    module: {
        loaders: [
                test: /\.jsx?$/,
                exclude: /node_modules/,
                loader: 'babel-loader',

                query: {
                    presets: ['es2015', 'react']

module.exports = config;

Then the package json file

  "name": "reactapp",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "webpack --progress",
    "production": "webpack -p --progress"
  "author": "",
  "license": "ISC",
  "dependencies": {
    "react": "^15.4.2",
    "react-dom": "^15.4.2",
    "webpack": "^2.2.1"
  "devDependencies": {
    "babel-core": "^6.0.20",
    "babel-loader": "^6.0.1",
    "babel-preset-es2015": "^6.0.15",
    "babel-preset-react": "^6.0.15",
    "babel-preset-stage-0": "^6.0.15",
    "express": "^4.13.3",
    "webpack": "^1.9.6",
    "webpack-devserver": "0.0.6"

Notice the script section and production section, production section is what gives you the final deployable index.js file ( name can be anything )

Rest fot the things will depend upon your code and components

Execute following sequence of commands

npm install

this should get you all the dependency (node modules)


npm run production

this should get you the final index.js file which will contain all the code bundled

Once done place index.html and index.js files under www/html or the web app root directory and that's all.

React.js: Identifying different inputs with one onChange handler

You can also do it like this:

constructor() {
    this.state = { input1: 0, input2: 0 };
    this.handleChange = this.handleChange.bind(this);

handleChange(input, value) {
        [input]: value

render() {
    const total = this.state.input1 + this.state.input2;
    return (
            {total}<br />
            <input type="text" onChange={e => this.handleChange('input1',} />
            <input type="text" onChange={e => this.handleChange('input2',} />

How do I navigate to another page when PHP script is done?

if ($done)
    header("Location: /url/to/the/other/page");

How to check if a variable is an integer or a string?

In my opinion you have two options:

  • Just try to convert it to an int, but catch the exception:

        value = int(value)
    except ValueError:
        pass  # it was a string, not an int.

    This is the Ask Forgiveness approach.

  • Explicitly test if there are only digits in the string:


    str.isdigit() returns True only if all characters in the string are digits (0-9).

    The unicode / Python 3 str type equivalent is unicode.isdecimal() / str.isdecimal(); only Unicode decimals can be converted to integers, as not all digits have an actual integer value (U+00B2 SUPERSCRIPT 2 is a digit, but not a decimal, for example).

    This is often called the Ask Permission approach, or Look Before You Leap.

The latter will not detect all valid int() values, as whitespace and + and - are also allowed in int() values. The first form will happily accept ' +10 ' as a number, the latter won't.

If your expect that the user normally will input an integer, use the first form. It is easier (and faster) to ask for forgiveness rather than for permission in that case.

How to tell which disk Windows Used to Boot

That depends on your definition of which disk drive Windows used to boot. I can think of 3 different answers on a standard BIOS system (who knows what an EFI system does):

  1. The drive that contains the active MBR
  2. The active partition, with NTLDR (the system partition)
  3. The partition with Windows on it (the boot partition)

2 and 3 should be easy to find - I'm not so sure about 1. Though you can raw disk read to find an MBR, that doesn't mean it's the BIOS boot device this time or even next time (you could have multiple disks with MBRs).

You really can't even be sure that the PC was started from a hard drive - it's perfectly possible to boot Windows from a floppy. In that case, both 1 and 2 would technically be a floppy disk, though 3 would remain C:\Windows.

You might need to be a bit more specific in your requirements or goals.

Meaning of Open hashing and Closed hashing

The use of "closed" vs. "open" reflects whether or not we are locked in to using a certain position or data structure (this is an extremely vague description, but hopefully the rest helps).

For instance, the "open" in "open addressing" tells us the index (aka. address) at which an object will be stored in the hash table is not completely determined by its hash code. Instead, the index may vary depending on what's already in the hash table.

The "closed" in "closed hashing" refers to the fact that we never leave the hash table; every object is stored directly at an index in the hash table's internal array. Note that this is only possible by using some sort of open addressing strategy. This explains why "closed hashing" and "open addressing" are synonyms.

Contrast this with open hashing - in this strategy, none of the objects are actually stored in the hash table's array; instead once an object is hashed, it is stored in a list which is separate from the hash table's internal array. "open" refers to the freedom we get by leaving the hash table, and using a separate list. By the way, "separate list" hints at why open hashing is also known as "separate chaining".

In short, "closed" always refers to some sort of strict guarantee, like when we guarantee that objects are always stored directly within the hash table (closed hashing). Then, the opposite of "closed" is "open", so if you don't have such guarantees, the strategy is considered "open".

SQL Query Where Date = Today Minus 7 Days

You can use the CURDATE() and DATE_SUB() functions to achieve this:

FROM ExternalHits

ASP.NET page life cycle explanation

This acronym might help you to remember the ASP.NET life cycle stages which I wrote about in the below blog post.


  1. Request
  2. Start
  3. Initialization
  4. Load
  5. Validation
  6. Post back handling
  7. Rendering
  8. Unload

From my blog: Understand ASP.NET Page life cycle and remember stages in easy way
18 May 2014

How do I get the APK of an installed app without root access?

List PackageManager.getInstalledApplications() will give you a list of the installed applications, and ApplicationInfo.sourceDir is the path to the .apk file.

// in oncreate
   PackageManager pm = getPackageManager(); 
   for (ApplicationInfo app : pm.getInstalledApplications(0)) {
 Log.d("PackageList", "package: " + app.packageName + ", sourceDir: " + app.sourceDir);

//output is something like
D/PackageList(5010): package: com.example.xmlparse, sourceDir: /data/app   /com.example.xmlparse-2.apk
D/PackageList(5010): package:, sourceDir: /data/app/
D/PackageList(5010): package: com.facebook.katana, sourceDir: /data/app/com.facebook.katana-1.apk
D/PackageList(5010): package: com.facebook.samples.profilepicture, sourceDir: /data/app/com.facebook.samples.profilepicture-1.apk
D/PackageList(5010): package: com.facebook.samples.sessionlogin, sourceDir: /data/app/com.facebook.samples.sessionlogin-1.apk
D/PackageList(5010): package: com.fitworld, sourceDir: /data/app/com.fitworld-2.apk
D/PackageList(5010): package:, sourceDir: /data/app/
D/PackageList(5010): package:, sourceDir: /system/app/FmmDM.apk
D/PackageList(5010): package: com.fmm.ds, sourceDir: /system/app/FmmDS.apk

Laravel 5: Display HTML with Blade

its a simple

{!! $text !!}

laravel compile as a dom element and {{$text}} print as a string

Center a popup window on screen?

(this was posted in 2020)

An extension to CrazyTim's answer

You can also set the width to a percentage (or a ratio) for a dynamic size. Absolute size is still accepted.

function popupWindow(url, title, w='75%', h='16:9', opts){
    // sort options
    let options = [];
    if(typeof opts === 'object'){
        Object.keys(opts).forEach(function(value, key){
            if(value === true){value = 'yes';}else if(value === false){value = 'no';}
        if(options.length){options = ','+options.join(',');}
        else{options = '';}
    }else if(Array.isArray(opts)){
        options = ','+opts.join(',');
    }else if(typeof opts === 'string'){
        options = ','+opts;
    }else{options = '';}

    // add most vars to local object (to shorten names)
    let size = {w: w, h: h};
    let win = {w: {i:, o:}, h: {i:, o:}, x: ||, y: ||}

    // set window size if percent
    if(typeof size.w === 'string' && size.w.endsWith('%')){size.w = Number(size.w.replace(/%$/, ''))*win.w.o/100;}
    if(typeof size.h === 'string' && size.h.endsWith('%')){size.h = Number(size.h.replace(/%$/, ''))*win.h.o/100;}

    // set window size if ratio
    if(typeof size.w === 'string' && size.w.includes(':')){
        size.w = size.w.split(':', 2);
        if(win.w.o < win.h.o){
            // if height is bigger than width, reverse ratio
            size.w = Number(size.h)*Number(size.w[1])/Number(size.w[0]);
        }else{size.w = Number(size.h)*Number(size.w[0])/Number(size.w[1]);}
    if(typeof size.h === 'string' && size.h.includes(':')){
        size.h = size.h.split(':', 2);
        if(win.w.o < win.h.o){
            // if height is bigger than width, reverse ratio
            size.h = Number(size.w)*Number(size.h[0])/Number(size.h[1]);
        }else{size.h = Number(size.w)*Number(size.h[1])/Number(size.h[0]);}

    // force window size to type number
    if(typeof size.w === 'string'){size.w = Number(size.w);}
    if(typeof size.h === 'string'){size.h = Number(size.h);}

    // keep popup window within padding of window size
    if(size.w > win.w.i-50){size.w = win.w.i-50;}
    if(size.h > win.h.i-50){size.h = win.h.i-50;}

    // do math
    const x = win.w.o / 2 + win.x - (size.w / 2);
    const y = win.h.o / 2 + win.y - (size.h / 2);
    return, title, `width=${size.w},height=${size.h},left=${x},top=${y}${options}`);


// width and height are optional (defaults: width = '75%' height = '16:9')
popupWindow('', 'Title', '75%', '16:9', {/* options (optional) */});

// options can be an object, array, or string

// example: object (only in object, true/false get replaced with 'yes'/'no')
const options = {scrollbars: false, resizable: true};

// example: array
const options = ['scrollbars=no', 'resizable=yes'];

// example: string (same as string)
const options = 'scrollbars=no,resizable=yes';

JavaScript alert box with timer

I finished my time alert with a unwanted effect.... Browsers add stuff to windows. My script is an aptated one and I will show after the following text.

I found a CSS script for popups, which doesn't have unwanted browser stuff. This was written by Prakash:- This script I will show after the following text.

This CSS script above looks professional and is alot more tidy. This button could be a clickable company logo image. By suppressing this button/image from running a function, this means you can run this function from inside javascript or call it with CSS, without it being run by clicking it.

This popup alert stays inside the window that popped it up. So if you are a multi-tasker you won't have trouble knowing what alert goes with what window.

The statements above are valid ones.... (Please allow). How these are achieved will be down to experimentation, as my knowledge of CSS is limited at the moment, but I learn fast.

CSS menus/DHTML use mouseover(valid statement).

I have a CSS menu script of my own which is adapted from 'Javascript for dummies' that pops up a menu alert. This works, but text size is limited. This hides under the top window banner. This could be set to be timed alert. This isn't great, but I will show this after the following text.

The Prakash script above I feel could be the answer if you can adapt it.

Scripts that follow:- My adapted timed window alert, Prakash's CSS popup script, my timed menu alert.


            <script language="JavaScript">
        // Variables
            strfiller0='<table border="1" cellspacing="0" width="98%"><tr><td><br>'+'Alert: '+'<br><hr width="98%"><br>'
            strfiller1='&nbsp;&nbsp;&nbsp;&nbsp; This alert is a timed one.'+'<br><br><br></td></tr></table>'
        // Javascript
            // This code belongs to Stephen Mayes Date: 25/07/2016 time:8:32 am

            function preview(){
                            preWindow= open("", "preWindow","status=no,toolbar=no,menubar=yes,width=350,height=180,left="+leftposition+",top=0");

    <input type="button" value=" Open " onclick="preview()">


body {
  font-family: Arial, sans-serif;
  background: url( no-repeat;
  background-size: cover;
  height: 100vh;

h1 {
  text-align: center;
  font-family: Tahoma, Arial, sans-serif;
  color: #06D85F;
  margin: 80px 0;

.box {
  width: 40%;
  margin: 0 auto;
  background: rgba(255,255,255,0.2);
  padding: 35px;
  border: 2px solid #fff;
  border-radius: 20px/50px;
  background-clip: padding-box;
  text-align: center;

.button {
  font-size: 1em;
  padding: 10px;
  color: #fff;
  border: 2px solid #06D85F;
  border-radius: 20px/50px;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.3s ease-out;
.button:hover {
  background: #06D85F;

.overlay {
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0.7);
  transition: opacity 500ms;
  visibility: hidden;
  opacity: 0;
.overlay:target {
  visibility: visible;
  opacity: 1;

.popup {
  margin: 70px auto;
  padding: 20px;
  background: #fff;
  border-radius: 5px;
  width: 30%;
  position: relative;
  transition: all 5s ease-in-out;

.popup h2 {
  margin-top: 0;
  color: #333;
  font-family: Tahoma, Arial, sans-serif;
.popup .close {
  position: absolute;
  top: 20px;
  right: 30px;
  transition: all 200ms;
  font-size: 30px;
  font-weight: bold;
  text-decoration: none;
  color: #333;
.popup .close:hover {
  color: #06D85F;
.popup .content {
  max-height: 30%;
  overflow: auto;

@media screen and (max-width: 700px){
    width: 70%;
    width: 70%;
    // written by Prakash:- 
<h1>Popup/Modal Windows without JavaScript</h1>
<div class="box">
    <a class="button" href="#popup1">Let me Pop up</a>

<div id="popup1" class="overlay">
    <div class="popup">
        <h2>Here i am</h2>
        <a class="close" href="#">&times;</a>
        <div class="content">
            Thank to pop me out of that button, but now i'm done so you can close this window.


<TITLE>Using DHTML to Create Sliding Menus (From JavaScript For Dummies, 4th Edition)</TITLE>
<SCRIPT LANGUAGE="JavaScript" TYPE="text/javascript">
<!-- Hide from older browsers

function displayMenu(currentPosition,nextPosition) {

    // Get the menu object located at the currentPosition on the screen
    var whichMenu = document.getElementById(currentPosition).style;

    if (displayMenu.arguments.length == 1) {
        // Only one argument was sent in, so we need to
        // figure out the value for "nextPosition"

        if (parseInt( == -5) {
            // Only two values are possible: one for mouseover
            // (-5) and one for mouseout (-90). So we want
            // to toggle from the existing position to the
            // other position: i.e., if the position is -5,
            // set nextPosition to -90...
            nextPosition = -90;
        else {
            // Otherwise, set nextPosition to -5
            nextPosition = -5;

    // Redisplay the menu using the value of "nextPosition" = nextPosition + "px";

// End hiding-->

<STYLE TYPE="text/css">

.menu {position:absolute; font:10px arial, helvetica, sans-serif; background-color:#ffffcc; layer-background-color:#ffffcc; top:-90px}
#resMenu {right:10px; width:-130px}
A {text-decoration:none; color:#000000}
A:hover {background-color:pink; color:blue}




<BODY BGCOLOR="white">

<div id="resMenu" class="menu" onmouseover="displayMenu('resMenu',-5)" onmouseout="displayMenu('resMenu',-90)"><br />
<a href="#"> Alert:</a><br>
<a href="#"> </a><br>
<a href="#"> You pushed that button again... Didn't yeah? </a><br>
<a href="#"> </a><br>
<a href="#"> </a><br>
<a href="#"> </a><br>
<input type="button" value="Wake that alert up" onclick="displayMenu('resMenu',-5)">

Getting IPV4 address from a sockaddr structure

Type casting of sockaddr to sockaddr_in and retrieval of ipv4 using inet_ntoa

char * ip = inet_ntoa(((struct sockaddr_in *)sockaddr)->sin_addr);

Is ConfigurationManager.AppSettings available in .NET Core 2.0?

The latest set of guidance is as follows: (from


System.Environment.GetEnvironmentVariable(name, EnvironmentVariableTarget.Process);

From the docs:

public static class EnvironmentVariablesExample
    public static void Run([TimerTrigger("0 */5 * * * *")]TimerInfo myTimer, ILogger log)
        log.LogInformation($"C# Timer trigger function executed at: {DateTime.Now}");

    public static string GetEnvironmentVariable(string name)
        return name + ": " +
            System.Environment.GetEnvironmentVariable(name, EnvironmentVariableTarget.Process);

App settings can be read from environment variables both when developing locally and when running in Azure. When developing locally, app settings come from the Values collection in the local.settings.json file. In both environments, local and Azure, GetEnvironmentVariable("<app setting name>") retrieves the value of the named app setting. For instance, when you're running locally, "My Site Name" would be returned if your local.settings.json file contains { "Values": { "WEBSITE_SITE_NAME": "My Site Name" } }.

The System.Configuration.ConfigurationManager.AppSettings property is an alternative API for getting app setting values, but we recommend that you use GetEnvironmentVariable as shown here.

How to log in to phpMyAdmin with WAMP, what is the username and password?

I installed Bitnami WAMP Stack 7.1.29-0 and it asked for a password during installation. In this case it was

username: root
password: <password set by you during install>

Best practices when running Node.js with port 80 (Ubuntu / Linode)

Port 80

What I do on my cloud instances is I redirect port 80 to port 3000 with this command:

sudo iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3000

Then I launch my Node.js on port 3000. Requests to port 80 will get mapped to port 3000.

You should also edit your /etc/rc.local file and add that line minus the sudo. That will add the redirect when the machine boots up. You don't need sudo in /etc/rc.local because the commands there are run as root when the system boots.


Use the forever module to launch your Node.js with. It will make sure that it restarts if it ever crashes and it will redirect console logs to a file.

Launch on Boot

Add your Node.js start script to the file you edited for port redirection, /etc/rc.local. That will run your Node.js launch script when the system starts.

Digital Ocean & other VPS

This not only applies to Linode, but Digital Ocean, AWS EC2 and other VPS providers as well. However, on RedHat based systems /etc/rc.local is /ect/rc.d/local.

How can I prevent a window from being resized with tkinter?

This is a variant of an existing solution already provided above:

import tkinter as tk

root = tk.Tk()
root.resizable(0, 0)

The advantage is that you type less.

LINQ .Any VS .Exists - What's the difference?

TLDR; Performance-wise Any seems to be slower (if I have set this up properly to evaluate both values at almost same time)

        var list1 = Generate(1000000);
        var forceListEval = list1.SingleOrDefault(o => o == "0123456789012");
        if (forceListEval != "sdsdf")
            var s = string.Empty;
            var start2 = DateTime.Now;
            if (!list1.Exists(o => o == "0123456789012"))
                var end2 = DateTime.Now;
                s += " Exists: " + end2.Subtract(start2);

            var start1 = DateTime.Now;
            if (!list1.Any(o => o == "0123456789012"))
                var end1 = DateTime.Now;
                s +=" Any: " +end1.Subtract(start1);

            if (!s.Contains("sdfsd"))


testing list generator:

private List<string> Generate(int count)
        var list = new List<string>();
        for (int i = 0; i < count; i++)
            list.Add( new string(
            Enumerable.Repeat("ABCDEFGHIJKLMNOPQRSTUVWXYZ", 13)
                .Select(s =>
                    var cryptoResult = new byte[4];
                    new RNGCryptoServiceProvider().GetBytes(cryptoResult);
                    return s[new Random(BitConverter.ToInt32(cryptoResult, 0)).Next(s.Length)];

        return list;

With 10M records

" Any: 00:00:00.3770377 Exists: 00:00:00.2490249"

With 5M records

" Any: 00:00:00.0940094 Exists: 00:00:00.1420142"

With 1M records

" Any: 00:00:00.0180018 Exists: 00:00:00.0090009"

With 500k, (I also flipped around order in which they get evaluated to see if there is no additional operation associated with whichever runs first.)

" Exists: 00:00:00.0050005 Any: 00:00:00.0100010"

With 100k records

" Exists: 00:00:00.0010001 Any: 00:00:00.0020002"

It would seem Any to be slower by magnitude of 2.

Edit: For 5 and 10M records I changed the way it generates the list and Exists suddenly became slower than Any which implies there's something wrong in the way I am testing.

New testing mechanism:

private static IEnumerable<string> Generate(int count)
        var cripto = new RNGCryptoServiceProvider();
        Func<string> getString = () => new string(
            Enumerable.Repeat("ABCDEFGHIJKLMNOPQRSTUVWXYZ", 13)
                .Select(s =>
                    var cryptoResult = new byte[4];
                    return s[new Random(BitConverter.ToInt32(cryptoResult, 0)).Next(s.Length)];

        var list = new ConcurrentBag<string>();
        var x = Parallel.For(0, count, o => list.Add(getString()));
        return list;

    private static void Test()
        var list = Generate(10000000);
        var list1 = list.ToList();
        var forceListEval = list1.SingleOrDefault(o => o == "0123456789012");
        if (forceListEval != "sdsdf")
            var s = string.Empty;

            var start1 = DateTime.Now;
            if (!list1.Any(o => o == "0123456789012"))
                var end1 = DateTime.Now;
                s += " Any: " + end1.Subtract(start1);

            var start2 = DateTime.Now;
            if (!list1.Exists(o => o == "0123456789012"))
                var end2 = DateTime.Now;
                s += " Exists: " + end2.Subtract(start2);

            if (!s.Contains("sdfsd"))


Edit2: Ok so to eliminate any influence from generating test data I wrote it all to file and now read it from there.

 private static void Test()
        var list1 = File.ReadAllLines("test.txt").Take(500000).ToList();
        var forceListEval = list1.SingleOrDefault(o => o == "0123456789012");
        if (forceListEval != "sdsdf")
            var s = string.Empty;
            var start1 = DateTime.Now;
            if (!list1.Any(o => o == "0123456789012"))
                var end1 = DateTime.Now;
                s += " Any: " + end1.Subtract(start1);

            var start2 = DateTime.Now;
            if (!list1.Exists(o => o == "0123456789012"))
                var end2 = DateTime.Now;
                s += " Exists: " + end2.Subtract(start2);

            if (!s.Contains("sdfsd"))


" Any: 00:00:00.1640164 Exists: 00:00:00.0750075"


" Any: 00:00:00.0810081 Exists: 00:00:00.0360036"


" Any: 00:00:00.0190019 Exists: 00:00:00.0070007"


" Any: 00:00:00.0120012 Exists: 00:00:00.0040004"

enter image description here

how to convert java string to Date object

The concise version:

String dateStr = "06/27/2007";
DateFormat formatter = new SimpleDateFormat("MM/dd/yyyy");
Date startDate = (Date)formatter.parse(dateStr);  

Add a try/catch block for a ParseException to ensure the format is a valid date.

Get first and last day of month using threeten, LocalDate

Try this:

LocalDate initial = LocalDate.of(2014, 2, 13);
LocalDate start = initial.withDayOfMonth(1);         
LocalDate end = initial.withDayOfMonth(initial.getMonthOfYear().getLastDayOfMonth(false));

you can find the desire output but need to take care of parameter true/false for getLastDayOfMonth method

that parameter denotes leap year

Get yesterday's date in bash on Linux, DST-safe

you can use

date -d "30 days ago" +"%d/%m/%Y"

to get the date from 30 days ago, similarly you can replace 30 with x amount of days

MaxJsonLength exception in ASP.NET MVC during JavaScriptSerializer

there is a bit other case - data is sent from client to server. when you are using controller method and model is huge :

    public ActionResult AddOrUpdateConsumerFile(FileMetaDataModelView inputModel)
        if (inputModel == null) return null;

system throws exception like this "Error during serialization or deserialization using the JSON JavaScriptSerializer. The length of the string exceeds the value set on the maxJsonLength property. Parameter name: input"

Only changing Web.config settings is not enough to help in this case. You could additionally override mvc json serializer for supporting huge data model sizes or manually deserialize model from Request. Your controller method becomes:

    public ActionResult AddOrUpdateConsumerFile()
        FileMetaDataModelView inputModel = RequestManager.GetModelFromJsonRequest<FileMetaDataModelView>(HttpContext.Request);
        if (inputModel == null) return null;

   public static T GetModelFromJsonRequest<T>(HttpRequestBase request)
        string result = "";
        using (Stream req = request.InputStream)
            req.Seek(0, System.IO.SeekOrigin.Begin);
            result = new StreamReader(req).ReadToEnd();
        return JsonConvert.DeserializeObject<T>(result);

Set "Homepage" in Asp.Net MVC

I tried the answer but it didn't worked for me. This is what i ended up doing:

Create a new controller DefaultController. In index action, i wrote one line redirect:

return Redirect("~/Default.aspx")

In RouteConfig.cs, change controller="Default" for the route.

            name: "Default",
            url: "{controller}/{action}/{id}",
            defaults: new { controller = "Default", action = "Index", id = UrlParameter.Optional }

font size in html code

Try this:

      <td style="padding-left: 5px;
                 padding-bottom: 3px;">
        <strong style="font-size: 35px;">Datum:</strong><br />
        November 2010 

Notice that I also included the table-tag, which you seem to have forgotten. This has to be included if you want this to appear as a table.

Getting Database connection in pure JPA setup

Since the code suggested by @Pascal is deprecated as mentioned by @Jacob, I found this another way that works for me.

import org.hibernate.classic.Session;
import org.hibernate.connection.ConnectionProvider;
import org.hibernate.engine.SessionFactoryImplementor;

Session session = (Session) em.getDelegate();
SessionFactoryImplementor sfi = (SessionFactoryImplementor) session.getSessionFactory();
ConnectionProvider cp = sfi.getConnectionProvider();
Connection connection = cp.getConnection();

How to verify element present or visible in selenium 2 (Selenium WebDriver)

To make sure that an element is present you can do the following:


That will return an array, if that array size is > 0 then the element/s is present.

Also, you need to provide more information, such as language and what have you tried before asking,

Good luck

Casting string to enum

As an extra, you can take the Enum.Parse answers already provided and put them in an easy-to-use static method in a helper class.

public static T ParseEnum<T>(string value)
    return (T)Enum.Parse(typeof(T), value, ignoreCase: true);

And use it like so:

   Content = ParseEnum<ContentEnum>(fileContentMessage);

Especially helpful if you have lots of (different) Enums to parse.

How to call a function, PostgreSQL

The function call still should be a valid SQL statement:

SELECT "saveUser"(3, 'asd','asd','asd','asd','asd');

Display a decimal in scientific notation

Here's an example using the format() function:

>>> "{:.2E}".format(Decimal('40800000000.00000000000000'))

Instead of format, you can also use f-strings:

>>> f"{Decimal('40800000000.00000000000000'):.2E}"

How do I evenly add space between a label and the input field regardless of length of text?

You can also used below code

            float: left;
            width: 113px;
  <form action="yourclassName.jsp">
    <span class="labelClass">First name: </span><input type="text" name="fname"><br>
    <span class="labelClass">Last name: </span><input type="text" name="lname"><br>
    <input type="submit" value="Submit">

How to choose an AES encryption mode (CBC ECB CTR OCB CFB)?

Please consider long and hard if you can't get around implementing your own cryptography

The ugly truth of the matter is that if you are asking this question you will probably not be able to design and implement a secure system.

Let me illustrate my point: Imagine you are building a web application and you need to store some session data. You could assign each user a session ID and store the session data on the server in a hash map mapping session ID to session data. But then you have to deal with this pesky state on the server and if at some point you need more than one server things will get messy. So instead you have the idea to store the session data in a cookie on the client side. You will encrypt it of course so the user cannot read and manipulate the data. So what mode should you use? Coming here you read the top answer (sorry for singling you out myforwik). The first one covered - ECB - is not for you, you want to encrypt more than one block, the next one - CBC - sounds good and you don't need the parallelism of CTR, you don't need random access, so no XTS and patents are a PITA, so no OCB. Using your crypto library you realize that you need some padding because you can only encrypt multiples of the block size. You choose PKCS7 because it was defined in some serious cryptography standards. After reading somewhere that CBC is provably secure if used with a random IV and a secure block cipher, you rest at ease even though you are storing your sensitive data on the client side.

Years later after your service has indeed grown to significant size, an IT security specialist contacts you in a responsible disclosure. She's telling you that she can decrypt all your cookies using a padding oracle attack, because your code produces an error page if the padding is somehow broken.

This is not a hypothetical scenario: Microsoft had this exact flaw in ASP.NET until a few years ago.

The problem is there are a lot of pitfalls regarding cryptography and it is extremely easy to build a system that looks secure for the layman but is trivial to break for a knowledgeable attacker.

What to do if you need to encrypt data

For live connections use TLS (be sure to check the hostname of the certificate and the issuer chain). If you can't use TLS, look for the highest level API your system has to offer for your task and be sure you understand the guarantees it offers and more important what it does not guarantee. For the example above a framework like Play offers client side storage facilities, it does not invalidate the stored data after some time, though, and if you changed the client side state, an attacker can restore a previous state without you noticing.

If there is no high level abstraction available use a high level crypto library. A prominent example is NaCl and a portable implementation with many language bindings is Sodium. Using such a library you do not have to care about encryption modes etc. but you have to be even more careful about the usage details than with a higher level abstraction, like never using a nonce twice. For custom protocol building (say you want something like TLS, but not over TCP or UDP) there are frameworks like Noise and associated implementations that do most of the heavy lifting for you, but their flexibility also means there is a lot of room for error, if you don't understand in depth what all the components do.

If for some reason you cannot use a high level crypto library, for example because you need to interact with existing system in a specific way, there is no way around educating yourself thoroughly. I recommend reading Cryptography Engineering by Ferguson, Kohno and Schneier. Please don't fool yourself into believing you can build a secure system without the necessary background. Cryptography is extremely subtle and it's nigh impossible to test the security of a system.

Comparison of the modes

Encryption only:

  • Modes that require padding: Like in the example, padding can generally be dangerous because it opens up the possibility of padding oracle attacks. The easiest defense is to authenticate every message before decryption. See below.
    • ECB encrypts each block of data independently and the same plaintext block will result in the same ciphertext block. Take a look at the ECB encrypted Tux image on the ECB Wikipedia page to see why this is a serious problem. I don't know of any use case where ECB would be acceptable.
    • CBC has an IV and thus needs randomness every time a message is encrypted, changing a part of the message requires re-encrypting everything after the change, transmission errors in one ciphertext block completely destroy the plaintext and change the decryption of the next block, decryption can be parallelized / encryption can't, the plaintext is malleable to a certain degree - this can be a problem.
  • Stream cipher modes: These modes generate a pseudo random stream of data that may or may not depend the plaintext. Similarly to stream ciphers generally, the generated pseudo random stream is XORed with the plaintext to generate the ciphertext. As you can use as many bits of the random stream as you like you don't need padding at all. Disadvantage of this simplicity is that the encryption is completely malleable, meaning that the decryption can be changed by an attacker in any way he likes as for a plaintext p1, a ciphertext c1 and a pseudo random stream r and attacker can choose a difference d such that the decryption of a ciphertext c2=c1?d is p2 = p1?d, as p2 = c2?r = (c1 ? d) ? r = d ? (c1 ? r). Also the same pseudo random stream must never be used twice as for two ciphertexts c1=p1?r and c2=p2?r, an attacker can compute the xor of the two plaintexts as c1?c2=p1?r?p2?r=p1?p2. That also means that changing the message requires complete reencryption, if the original message could have been obtained by an attacker. All of the following steam cipher modes only need the encryption operation of the block cipher, so depending on the cipher this might save some (silicon or machine code) space in extremely constricted environments.
    • CTR is simple, it creates a pseudo random stream that is independent of the plaintext, different pseudo random streams are obtained by counting up from different nonces/IVs which are multiplied by a maximum message length so that overlap is prevented, using nonces message encryption is possible without per message randomness, decryption and encryption are completed parallelizable, transmission errors only effect the wrong bits and nothing more
    • OFB also creates a pseudo random stream independent of the plaintext, different pseudo random streams are obtained by starting with a different nonce or random IV for every message, neither encryption nor decryption is parallelizable, as with CTR using nonces message encryption is possible without per message randomness, as with CTR transmission errors only effect the wrong bits and nothing more
    • CFB's pseudo random stream depends on the plaintext, a different nonce or random IV is needed for every message, like with CTR and OFB using nonces message encryption is possible without per message randomness, decryption is parallelizable / encryption is not, transmission errors completely destroy the following block, but only effect the wrong bits in the current block
  • Disk encryption modes: These modes are specialized to encrypt data below the file system abstraction. For efficiency reasons changing some data on the disc must only require the rewrite of at most one disc block (512 bytes or 4kib). They are out of scope of this answer as they have vastly different usage scenarios than the other. Don't use them for anything except block level disc encryption. Some members: XEX, XTS, LRW.

Authenticated encryption:

To prevent padding oracle attacks and changes to the ciphertext, one can compute a message authentication code (MAC) on the ciphertext and only decrypt it if it has not been tampered with. This is called encrypt-then-mac and should be preferred to any other order. Except for very few use cases authenticity is as important as confidentiality (the latter of which is the aim of encryption). Authenticated encryption schemes (with associated data (AEAD)) combine the two part process of encryption and authentication into one block cipher mode that also produces an authentication tag in the process. In most cases this results in speed improvement.

  • CCM is a simple combination of CTR mode and a CBC-MAC. Using two block cipher encryptions per block it is very slow.
  • OCB is faster but encumbered by patents. For free (as in freedom) or non-military software the patent holder has granted a free license, though.
  • GCM is a very fast but arguably complex combination of CTR mode and GHASH, a MAC over the Galois field with 2^128 elements. Its wide use in important network standards like TLS 1.2 is reflected by a special instruction Intel has introduced to speed up the calculation of GHASH.


Considering the importance of authentication I would recommend the following two block cipher modes for most use cases (except for disk encryption purposes): If the data is authenticated by an asymmetric signature use CBC, otherwise use GCM.

How to refer to Excel objects in Access VBA?

First you need to set a reference (Menu: Tools->References) to the Microsoft Excel Object Library then you can access all Excel Objects.

After you added the Reference you have full access to all Excel Objects. You need to add Excel in front of everything for example:

Dim xlApp as Excel.Application

Let's say you added an Excel Workbook Object in your Form and named it xLObject.

Here is how you Access a Sheet of this Object and change a Range

Dim sheet As Excel.Worksheet
Set sheet = xlObject.Object.Sheets(1)
sheet.Range("A1") = "Hello World"

(I copied the above from my answer to this question)

Another way to use Excel in Access is to start Excel through a Access Module (the way shahkalpesh described it in his answer)

Convert alphabet letters to number in Python

Something like this

[str(ord(c)&31) for c in text]

How do I make a branch point at a specific commit?

You can make master point at 1258f0d0aae this way:

git checkout master
git reset --hard 1258f0d0aae

But you have to be careful about doing this. It may well rewrite the history of that branch. That would create problems if you have published it and other people are working on the branch.

Also, the git reset --hard command will throw away any uncommitted changes (i.e. those just in your working tree or the index).

You can also force an update to a branch with:

git branch -f master 1258f0d0aae

... but git won't let you do that if you're on master at the time.

Link error "undefined reference to `__gxx_personality_v0'" and g++

It sounds like you're trying to link with your resulting object file with gcc instead of g++:

Note that programs using C++ object files must always be linked with g++, in order to supply the appropriate C++ libraries. Attempting to link a C++ object file with the C compiler gcc will cause "undefined reference" errors for C++ standard library functions:

$ g++ -Wall -c
$ gcc hello.o       (should use g++)
hello.o: In function `main':
hello.o(.text+0x1b): undefined reference to `std::cout'
  undefined reference to `__gxx_personality_v0'

Source: An Introduction to GCC - for the GNU compilers gcc and g++

Can't build create-react-app project with custom PUBLIC_URL

Actually the way of setting environment variables is different between different Operating System.

Windows (cmd.exe)

set PUBLIC_URL= start

(Note: the lack of whitespace is intentional.)

Linux, macOS (Bash)

 PUBLIC_URL= npm start

Recommended: cross-env

  "scripts": {
    "serve": "cross-env PUBLIC_URL= npm start"

ref: create-react-app/ at master · facebookincubator/create-react-app

Submitting a form on 'Enter' with jQuery?

I use now


At first I added an eventhandler to the submit button which produced an error for me.

LEFT JOIN only first row

Version without subselect:

   SELECT f.title,
          MIN(a.artist_name) artist_name
     FROM feeds f
LEFT JOIN feeds_artists fa ON fa.feed_id =
LEFT JOIN artists a ON fa.artist_id = a.artist_id

How to get a JavaScript object's class?

To get the "pseudo class", you can get the constructor function, by


assuming the constructor is set correctly when you do the inheritance -- which is by something like:

Dog.prototype = new Animal();
Dog.prototype.constructor = Dog;

and these two lines, together with:

var woofie = new Dog()

will make woofie.constructor point to Dog. Note that Dog is a constructor function, and is a Function object. But you can do if (woofie.constructor === Dog) { ... }.

If you want to get the class name as a string, I found the following working well:

function getObjectClass(obj) {
    if (obj && obj.constructor && obj.constructor.toString) {
        var arr = obj.constructor.toString().match(

        if (arr && arr.length == 2) {
            return arr[1];

    return undefined;

It gets to the constructor function, converts it to string, and extracts the name of the constructor function.

Note that could have worked well, but it is not standard. It is on Chrome and Firefox, but not on IE, including IE 9 or IE 10 RTM.

What is a good practice to check if an environmental variable exists or not?

I'd recommend the following solution.

It prints the env vars you didn't include, which lets you add them all at once. If you go for the for loop, you're going to have to rerun the program to see each missing var.

from os import environ

REQUIRED_ENV_VARS = {"A", "B", "C", "D"}
diff = REQUIRED_ENV_VARS.difference(environ)
if len(diff) > 0:
    raise EnvironmentError(f'Failed because {diff} are not set')

What exactly is node.js used for?

Node.js is an open source command line tool built for the server side JavaScript code.

Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications.

Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.

The basic philosophy of node.js is:

Non-blocking I/O - every I/O call must take a callback, whether it is to retrieve information from disk, network or another process. Built-in support for the most important protocols (HTTP, DNS, TLS) Low-level. Do not remove functionality present at the POSIX layer. For example, support half-closed TCP connections. Stream everything; never force the buffering of data.

Credit - Simple Overview About Node.js

How can I cast int to enum?

enter image description here

To convert a string to ENUM or int to ENUM constant we need to use Enum.Parse function. Here is a youtube video which actually demonstrate's with string and the same applies for int.

The code goes as shown below where "red" is the string and "MyColors" is the color ENUM which has the color constants.

MyColors EnumColors = (MyColors)Enum.Parse(typeof(MyColors), "Red");

Boolean.parseBoolean("1") = false...?

I know this is an old thread, but what about borrowing from C syntax:

(o.get('uses_votes')).equals("1") ? true : false;

Bootstrap's JavaScript requires jQuery version 1.9.1 or higher

meteor add thelohoadmin:bootstrap@=3.3.7 solves the issue. You get the latest bootstrap and no warning messages.

Is there a simple, elegant way to define singletons?

I don't really see the need, as a module with functions (and not a class) would serve well as a singleton. All its variables would be bound to the module, which could not be instantiated repeatedly anyway.

If you do wish to use a class, there is no way of creating private classes or private constructors in Python, so you can't protect against multiple instantiations, other than just via convention in use of your API. I would still just put methods in a module, and consider the module as the singleton.

Visual Studio 2017 does not have Business Intelligence Integration Services/Projects

SSIS Integration with Visual Studio 2017 available from Aug 2017.

SSIS designer is now available for Visual Studio 2017! ARCHIVE

I installed in July 2018 and appears working fine. See Download link

scrollIntoView Scrolls just too far

If it's about 10px, then I guess you could simply manually adjust the containing div's scroll offset like that:

document.getElementById("containingDiv").scrollTop -= 10;

What I can do to resolve "1 commit behind master"?

If the branch is behind master, then delete the remote branch. Then go to local branch and run :

git pull origin master --rebase

Then, again push the branch to origin:

git push -u origin <branch-name>

Change Name of Import in Java, or import two classes with the same name

It's probably worth noting that Groovy has this feature:

import java.util.Calendar
import com.example.Calendar as MyCalendar

MyCalendar myCalendar = new MyCalendar()

maven compilation failure

The error is pretty clear: "cannot find symbol". Some dependencies can't be resolved (you even have the line and column in the trace of the reference that can't be resolved):

V:/dhs_tss_build_view/dhs_tssproject/tss/tsscommon-server/src/main/java/us/mn/state/dhs/tss/common/oblix/da/wsdl/OblixLoginAc[51,60] cannot find symbol
symbol  : class BusinessException
location: class

ava:[187,14] cannot find symbol
symbol  : class Phone
location: class

ava:[204,14] cannot find symbol
symbol  : class Phone
location: class

Below a couple of things to verify:

  • Check or recheck that these classes are in the jar A (same version as in the pom)
  • Check or recheck the import statement in B sources (should match the package of classes in A)
  • Check or recheck B's pom.xml and especially the declaration of the dependency on A (it's version)
  • Check that the dependency on A is not excluded transitively somewhere in B's pom
  • Is A a SNAPSHOT dependency? If no, delete A from your local repository and rebuild

Maven is working fine, you have a mistake somewhere.

Where is the correct location to put in an Eclipse project?

If you have a library and you want to append the log4j:

  1. Create a folder named "resources" in your projet.
  2. Create a .properties file named log4j
  3. Set properties in file
  4. Push right button in the project and go to properties->Java Build Path and, finally, go to the "Source" tab.
  5. Push Add folder and search the "resources" folder created in step 1.
  6. Finish.

(I have assumed that you have the log4j library added.)

PD: Sorry for my english.

How can I reorder a list?

From what I understand of your question, it appears that you want to apply a permutation that you specify on a list. This is done by specifying another list (lets call it p) that holds the indices of the elements of the original list that should appear in the permuted list. You then use p to make a new list by simply substituting the element at each position by that whose index is in that position in p.

def apply_permutation(lst, p):
    return [lst[x] for x in p]


print apply_permutation(arr,new_order)

This prints ['d', 'c', 'a', 'b', 'e'].

This actually creates a new list, but it can be trivially modified to permute the original "in place".

how to use Spring Boot profiles

Use ",local" in Intellij IDEA. It's working. Its sets 2 profiles "foo and local".

Verified with boot version "2.3.2.RELEASE" & Intellij IDEA CE 2019.3.


Setting profile with "mvn spring-boot:run" enter image description here

Setting environment variable enter image description here

ImportError: DLL load failed: The specified module could not be found

Quick note: Check if you have other Python versions, if you have removed them, make sure you did that right. If you have Miniconda on your system then Python will not be removed easily.

What worked for me: removed other Python versions and the Miniconda, reinstalled Python and the matplotlib library and everything worked great.

How to Convert Int to Unsigned Byte and Back

A byte is always signed in Java. You may get its unsigned value by binary-anding it with 0xFF, though:

int i = 234;
byte b = (byte) i;
System.out.println(b); // -22
int i2 = b & 0xFF;
System.out.println(i2); // 234

How to store and retrieve a dictionary with redis

The redis SET command stores a string, not arbitrary data. You could try using the redis HSET command to store the dict as a redis hash with something like

for k,v in my_dict.iteritems():
    r.hset('my_dict', k, v)

but the redis datatypes and python datatypes don't quite line up. Python dicts can be arbitrarily nested, but a redis hash is going to require that your value is a string. Another approach you can take is to convert your python data to string and store that in redis, something like

r.set('this_dict', str(my_dict))

and then when you get the string out you will need to parse it to recreate the python object.

Scroll Automatically to the Bottom of the Page

A picture is worth a thousand words:

The key is:

  left: 0,
  top: document.documentElement.scrollHeight - document.documentElement.clientHeight,
  behavior: 'smooth'

It is using document.documentElement, which is the <html> element. It is just like using window, but it is just my personal preference to do it this way, because if it is not the whole page but a container, it works just like this except you'd change document.body and document.documentElement to document.querySelector("#container-id").


let cLines = 0;_x000D_
let timerID = setInterval(function() {_x000D_
  let elSomeContent = document.createElement("div");_x000D_
  if (++cLines > 33) {_x000D_
    elSomeContent.innerText = "That's all folks!";_x000D_
  } else {_x000D_
    elSomeContent.innerText = new Date().toLocaleDateString("en", {_x000D_
      dateStyle: "long",_x000D_
      timeStyle: "medium"_x000D_
    left: 0,_x000D_
    top: document.documentElement.scrollHeight - document.documentElement.clientHeight,_x000D_
    behavior: 'smooth'_x000D_
}, 1000);
body {_x000D_
  font: 27px Arial, sans-serif;_x000D_
  background: #ffc;_x000D_
  color: #333;_x000D_

You can compare the difference if there is no scrollTo():

let cLines = 0;_x000D_
let timerID = setInterval(function() {_x000D_
  let elSomeContent = document.createElement("div");_x000D_
  if (++cLines > 33) {_x000D_
    elSomeContent.innerText = "That's all folks!";_x000D_
  } else {_x000D_
    elSomeContent.innerText = new Date().toLocaleDateString("en", {_x000D_
      dateStyle: "long",_x000D_
      timeStyle: "medium"_x000D_
}, 1000);
body {_x000D_
  font: 27px Arial, sans-serif;_x000D_
  background: #ffc;_x000D_
  color: #333;_x000D_

Difference between Xms and Xmx and XX:MaxPermSize

Java objects reside in an area called the heap, while metadata such as class objects and method objects reside in the permanent generation or Perm Gen area. The permanent generation is not part of the heap.

The heap is created when the JVM starts up and may increase or decrease in size while the application runs. When the heap becomes full, garbage is collected. During the garbage collection objects that are no longer used are cleared, thus making space for new objects.

-Xmssize Specifies the initial heap size.

-Xmxsize Specifies the maximum heap size.

-XX:MaxPermSize=size Sets the maximum permanent generation space size. This option was deprecated in JDK 8, and superseded by the -XX:MaxMetaspaceSize option.

Sizes are expressed in bytes. Append the letter k or K to indicate kilobytes, m or M to indicate megabytes, g or G to indicate gigabytes.


How is the java memory pool divided?

What is perm space?

Java (JVM) Memory Model – Memory Management in Java

Java 7 SE Command Line Options

Java 7 HotSpot VM Options

Deleting a local branch with Git

This worked for me...
I have removed the folders there in .git/worktrees folder and then tried "git delete -D branch-name".

Convert an int to ASCII character

Doing college work I gathered the data I found and gave me this result:

"The input consists of a single line with multiple integers, separated by a blank space. The end of the entry is identified by the number -1, which should not be processed."

#include <iostream>
#include <cstdlib>

using namespace std;

int main()
    char numeros[100]; //vetor para armazenar a entrada dos numeros a serem convertidos
    int count = 0, soma = 0;

    cin.getline(numeros, 100);

    system("cls"); // limpa a tela

    for(int i = 0; i < 100; i++)
        if (numeros[i] == '-') // condicao de existencia do for
            i = 100;
            if(numeros[i] == ' ') // condicao que ao encontrar um espaco manda o resultado dos dados lidos e zera a contagem
                if(count == 2) // se contegem for 2 divide por 10 por nao ter casa da centena
                    soma = soma / 10;
                if(count == 1) // se contagem for 1 divide por 100 por nao ter casa da dezena
                    soma = soma / 100;

                cout << (char)soma; // saida das letras do codigo ascii
                count = 0;

                count ++; // contagem aumenta para saber se o numero esta na centena/dezena ou unitaria
                if(count == 1)
                    soma =  ('0' - numeros[i]) * -100; // a ideia é que o resultado de '0' - 'x' = -x (um numero inteiro)
                if(count == 2)
                    soma = soma + ('0' - numeros[i]) * -10; // todos multiplicam por -1 para retornar um valor positivo
                if(count == 3)
                    soma = soma + ('0' - numeros[i]) * -1; /* caso pense em entrada de valores na casa do milhar, deve-se alterar esses 3 if´s
        alem de adicionar mais um para a casa do milhar. */

    return 0;

The comments are in Portuguese but I think you should understand. Any questions send me a message on linkedin:

How to use Python's "easy_install" on Windows ... it's not so easy

One problem is that easy_install is set up to download and install .egg files or source distributions (contained within .tgz, .tar, .tar.gz, .tar.bz2, or .zip files). It doesn't know how to deal with the PyWin32 extensions because they are put within a separate installer executable. You will need to download the appropriate PyWin32 installer file (for Python 2.7) and run it yourself. When you run easy_install again (provided you have it installed right, like in Sergio's instructions), you should see that your winpexpect package has been installed correctly.

Since it's Windows and open source we are talking about, it can often be a messy combination of install methods to get things working properly. However, easy_install is still better than hand-editing configuration files, for sure.

Oracle Trigger ORA-04098: trigger is invalid and failed re-validation

Cause: A trigger was attempted to be retrieved for execution and was found to be invalid. This also means that compilation/authorization failed for the trigger.

Action: Options are to resolve the compilation/authorization errors, disable the trigger, or drop the trigger.




Array initializing in Scala

If you know Array's length but you don't know its content, you can use

val length = 5
val temp = Array.ofDim[String](length)

If you want to have two dimensions array but you don't know its content, you can use

val row = 5
val column = 3
val temp = Array.ofDim[String](row, column)

Of course, you can change String to other type.

If you already know its content, you can use

val temp = Array("a", "b")

Pass parameter to EventHandler

Timer.Elapsed expects method of specific signature (with arguments object and EventArgs). If you want to use your PlayMusicEvent method with additional argument evaluated during event registration, you can use lambda expression as an adapter:

myTimer.Elapsed += new ElapsedEventHandler((sender, e) => PlayMusicEvent(sender, e, musicNote));

Edit: you can also use shorter version:

myTimer.Elapsed += (sender, e) => PlayMusicEvent(sender, e, musicNote);

Python function to convert seconds into minutes, hours, and days

This will convert n seconds into d days, h hours, m minutes, and s seconds.

from datetime import datetime, timedelta

def GetTime():
    sec = timedelta(seconds=int(input('Enter the number of seconds: ')))
    d = datetime(1,1,1) + sec

    print("%d:%d:%d:%d" % (, d.hour, d.minute, d.second))

failed to open stream: No such file or directory in

It's because you have included a leading / in your file path. The / makes it start at the top of your filesystem. Note: filesystem path, not Web site path (you're not accessing it over HTTP). You can use a relative path with include_once (one that doesn't start with a leading /).

You can change it to this:

include_once 'headerSite.php';

That will look first in the same directory as the file that's including it (i.e. C:\xampp\htdocs\PoliticalForum\ in your example.

Maximum number of rows in an MS Access database engine table?

It's been some years since I last worked with Access but larger database files always used to have more problems and be more prone to corruption than smaller files.

Unless the database file is only being accessed by one person or stored on a robust network you may find this is a problem before the 2GB database size limit is reached.

Set timeout for webClient.DownloadFile()

Assuming you wanted to do this synchronously, using the WebClient.OpenRead(...) method and setting the timeout on the Stream that it returns will give you the desired result:

using (var webClient = new WebClient())
using (var stream = webClient.OpenRead(streamingUri))
     if (stream != null)
          stream.ReadTimeout = Timeout.Infinite;
          using (var reader = new StreamReader(stream, Encoding.UTF8, false))
               string line;
               while ((line = reader.ReadLine()) != null)
                    if (line != String.Empty)
                        Console.WriteLine("Count {0}", count++);

Deriving from WebClient and overriding GetWebRequest(...) to set the timeout @Beniamin suggested, didn't work for me as, but this did.

codes for ADD,EDIT,DELETE,SEARCH in vb2010

A good resource start off point would be MSDN as your looking into a microsoft product

Generate a sequence of numbers in Python

Assuming your sequence alternates increments between 1 and 3

numbers = [1]
while numbers[-1] < 100:
    numbers.append(numbers[-1] + 1)
    numbers.append(numbers[-1] + 3)

print ', '.join(map(str, numbers))

This could be easier to modify if your sequence is different but I think poke or BlaXpirit are nicer answers than mine.

Looping over elements in jQuery

Depending on what you need each child for (if you're looking to post it somewhere via AJAX) you can just do...


It creates a string for you with all of the values automatically.

As for looping through objects, you can also do this.

$.each($("input, select, textarea"), function(i,v) {
    var theTag = v.tagName;
    var theElement = $(v);
    var theValue = theElement.val();

How can I backup a Docker-container with its data-volumes?

If you like entering arcane operators from the command line, you’ll love these manual container backup techniques. Keep in mind, there’s a faster and more efficient way to backup containers that’s just as effective. I've written instructions here:

Step 1: Add a Docker Host to Any Cloud As explained in a tutorial on the Morpheus support site, you can add a Docker host to the cloud of your choice in a matter of seconds. Start by choosing Infrastructure on the main Morpheus navigation bar. Select Hosts at the top of the Infrastructure window, and click the “+Container Hosts” button at the top right.

To back up a Docker host to a cloud via Morpheus, navigate to the Infrastructure screen and open the “+Container Hosts” menu.

Choose a container host type on the menu, select a group, and then enter data in the five fields: Name, Description, Visibility, Select a Cloud and Enter Tags (optional). Click Next, and then configure the host options by choosing a service plan. Note that the Volume, Memory, and CPU count fields will be visible only if the plan you select has custom options enabled.

Here is where you add and size volumes, set memory size and CPU count, and choose a network. You can also configure the OS username and password, the domain name, and the hostname, which by default is the container name you entered previously. Click Next, and then add any Automation Workflows (optional).Finally, review your settings and click Complete to save them.

Step 2: Add Docker Registry Integration to Public or Private Clouds Adam Hicks describes in another Morpheus tutorial how simple it is to integrate with a private Docker Registry. (No added configuration is required to use Morpheus to provision images with Docker’s public hub using the public Docker API.)

Select Integrations under the Admin tab of the main navigation bar, and then choose the “+New Integration” button on the right side of the screen. In the Integration window that appears, select Docker Repository in the Type drop-down menu, enter a name and add the private registry API endpoint. Supply a username and password for the registry you’re using, and click the Save Changes button.

Integrate a Docker Registry with a private cloud via the Morpheus “New Integration” dialog box.

To provision the integration you just created, choose Docker under Type in the Create Instance dialog, select the registry in the Docker Registry drop-down menu under the Configure tab, and then continue provisioning as you would any Docker container.

Step 3: Manage Backups Once you’ve added the Docker host and integrated the registry, a backup will be configured and performed automatically for each instance you provision. Morpheus support provides instructions for viewing backups, creating an instance backup, and creating a server backup.

Difference between int32, int, int32_t, int8 and int8_t

Always keep in mind that 'size' is variable if not explicitly specified so if you declare

 int i = 10;

On some systems it may result in 16-bit integer by compiler and on some others it may result in 32-bit integer (or 64-bit integer on newer systems).

In embedded environments this may end up in weird results (especially while handling memory mapped I/O or may be consider a simple array situation), so it is highly recommended to specify fixed size variables. In legacy systems you may come across

 typedef short INT16;
 typedef int INT32;
 typedef long INT64; 

Starting from C99, the designers added stdint.h header file that essentially leverages similar typedefs.

On a windows based system, you may see entries in stdin.h header file as

 typedef signed char       int8_t;
 typedef signed short      int16_t;
 typedef signed int        int32_t;
 typedef unsigned char     uint8_t;

There is quite more to that like minimum width integer or exact width integer types, I think it is not a bad thing to explore stdint.h for a better understanding.

Submit form with Enter key without submit button?

Change #form to your form's ID

$('#form input').keydown(function(e) {
    if (e.keyCode == 13) {

Or alternatively

$('input').keydown(function(e) {
    if (e.keyCode == 13) {

Open a selected file (image, pdf, ...) programmatically from my Android Application?

Try the following code.

File file = new File(path); // path = your file path
lastSlash = file.toString().lastIndexOf('/');

if (lastSlash >= 0)
    fileName = url.toString().substring(lastSlash + 1);

if (fileName.endsWith("pdf"))
    mimeType = "application/pdf";
    mimeType = MimeTypeMap.getSingleton().getMimeTypeFromExtension

Uri uri_path = Uri.fromFile(file);

Intent intent = new Intent(android.content.Intent.ACTION_VIEW);
intent.putExtra(PATH, path);
intent.putExtra(MIMETYPE, mimeType);
intent.setDataAndType(uri_path, mimeType);


Trying to add adb to PATH variable OSX

enter image description here

2nd solution is explained below. But when i close the terminal the change which i made in path variable gets lost. Thus i prefer the first way!

enter image description here

C# - How to add an Excel Worksheet programmatically - Office XP / 2003

Another "Up Tick" for AR..., but if you don't have to use interop I would avoid it altogether. This product is actually quite interesting: and it provides a very intuitive, fully managed, api for manipulation excel files and seems to be free. (at least for the time being) SpreadSheetGear is also excellent but pricey.

my two cents.

'this' is undefined in JavaScript class methods

Use arrow function:

Request.prototype.start = () => {
    if( this.stay_open == true ) {{msg: 'listen'});
    } else {


What is the regex pattern for datetime (2008-09-01 12:35:45 )?

Adding to @Greg Hewgill answer: if you want to be able to match both date-time and only date, you can make the "time" part of the regex optional:

(\d{4})-(\d{2})-(\d{2})( (\d{2}):(\d{2}):(\d{2}))?

this way you will match both 2008-09-01 12:35:42 and 2008-09-01

Is there a way to use SVG as content in a pseudo element :before or :after

Making use of CSS sprites and data uri gives extra interesting benefits like fast loading and less requests AND we get IE8 support by using image/base64:

Codepen sample using SVG


<div class="div1"></div>
<div class="div2"></div>


.div1:after, .div2:after {
  content: '';
  display: block;
  height: 80px;
  width: 80px;
  background-image: url(data:image/svg+xml,;
.div2:after {
  background-position: -80px 0;

For IE8, change to this:

  background-image: url(data:image/png;base64,data......);

What is the purpose of Android's <merge> tag in XML layouts?

Another reason to use merge is when using custom viewgroups in ListViews or GridViews. Instead of using the viewHolder pattern in a list adapter, you can use a custom view. The custom view would inflate an xml whose root is a merge tag. Code for adapter:

public class GridViewAdapter extends BaseAdapter {
     // ... typical Adapter class methods
     public View getView(int position, View convertView, ViewGroup parent) {
        WallpaperView wallpaperView;
        if (convertView == null)
           wallpaperView = new WallpaperView(activity);
            wallpaperView = (WallpaperView) convertView;

        wallpaperView.loadWallpaper(wallpapers.get(position), imageWidth);
        return wallpaperView;

here is the custom viewgroup:

public class WallpaperView extends RelativeLayout {

    public WallpaperView(Context context) {
    // ... typical constructors

    private void init(Context context) {
        View.inflate(context, R.layout.wallpaper_item, this);
        imageLoader = AppController.getInstance().getImageLoader();
        imagePlaceHolder = (ImageView) findViewById(;
        thumbnail = (NetworkImageView) findViewById(;

    public void loadWallpaper(Wallpaper wallpaper, int imageWidth) {
        // ...some logic that sets the views

and here is the XML:

<merge xmlns:android="">

        android:src="@drawable/ico_loader" />

        android:layout_height="wrap_content" />


@RequestParam in Spring MVC handling optional parameters

Create 2 methods which handle the cases. You can instruct the @RequestMapping annotation to take into account certain parameters whilst mapping the request. That way you can nicely split this into 2 methods.

@RequestMapping (value="/submit/id/{id}", method=RequestMethod.GET, 
                 produces="text/xml", params={"logout"})
public String handleLogout(@PathVariable("id") String id, 
        @RequestParam("logout") String logout) { ... }

@RequestMapping (value="/submit/id/{id}", method=RequestMethod.GET, 
                 produces="text/xml", params={"name", "password"})
public String handleLogin(@PathVariable("id") String id, @RequestParam("name") 
        String username, @RequestParam("password") String password, 
        @ModelAttribute("submitModel") SubmitModel model, BindingResult errors) 
        throws LoginException {...}

ERROR 2003 (HY000): Can't connect to MySQL server on '' (111)

You need to change the bind-address parameter to in the mysql config file (my.ini or my.cnf) or use the one that is defined there.

If that doesn't work you should check that the mysql service is actually running.

How to reference static assets within vue javascript

Of course src="@/assets/images/x.jpg works, but better way is: src="~assets/images/x.jpg

Calling a java method from c++ in Android

Solution posted by Denys S. in the question post:

I quite messed it up with c to c++ conversion (basically env variable stuff), but I got it working with the following code for C++:

#include <string.h>
#include <stdio.h>
#include <jni.h>

jstring Java_the_package_MainActivity_getJniString( JNIEnv* env, jobject obj){

    jstring jstr = (*env)->NewStringUTF(env, "This comes from jni.");
    jclass clazz = (*env)->FindClass(env, "com/inceptix/android/t3d/MainActivity");
    jmethodID messageMe = (*env)->GetMethodID(env, clazz, "messageMe", "(Ljava/lang/String;)Ljava/lang/String;");
    jobject result = (*env)->CallObjectMethod(env, obj, messageMe, jstr);

    const char* str = (*env)->GetStringUTFChars(env,(jstring) result, NULL); // should be released but what a heck, it's a tutorial :)
    printf("%s\n", str);

    return (*env)->NewStringUTF(env, str);

And next code for java methods:

    public class MainActivity extends Activity {
    private static String LIB_NAME = "thelib";

    static {

    /** Called when the activity is first created. */
    public void onCreate(Bundle savedInstanceState) {
        TextView tv = (TextView) findViewById(;

    // please, let me live even though I used this dark programming technique
    public String messageMe(String text) {
        return text;

    public native String getJniString();

Find an object in SQL Server (cross-database)

Easiest way is to hit up the information_schemas...

FROM information_schema.Tables
WHERE [Table_Name]='????'

FROM information_schema.Views
WHERE [Table_Name]='????'

FROM information_schema.Routines
WHERE [Routine_Name]='????'