Programs & Examples On #Freemind

Array copy values to keys in PHP

$final_array = array_combine($a, $a);


P.S. Be careful with source array containing duplicated keys like the following:

$a = ['one','two','one'];

Note the duplicated one element.

How to convert .pem into .key?

just as a .crt file is in .pem format, a .key file is also stored in .pem format. Assuming that the cert is the only thing in the .crt file (there may be root certs in there), you can just change the name to .pem. The same goes for a .key file. Which means of course that you can rename the .pem file to .key.

Which makes gtrig's answer the correct one. I just thought I'd explain why.

Difference between if () { } and if () : endif;

There is no technical difference between the two syntaxes. The alternative syntax is not new; it was supported at least as far back as PHP 4, and perhaps even earlier.

You might prefer the alternative form because it explicitly states which control structure is ending: endwhile, for example, can only terminate a while block, whereas if you encounter a brace, it could be closing anything.

You might prefer the traditional syntax, though, if you use an editor that has special support for braces in other C-like syntaxes. Vim, for example, supports several keystrokes for navigating to matching braces and to the starts and ends of brace-delimited blocks. The alternative syntax would break that editor feature.

What does this square bracket and parenthesis bracket notation mean [first1,last1)?

A bracket - [ or ] - means that end of the range is inclusive -- it includes the element listed. A parenthesis - ( or ) - means that end is exclusive and doesn't contain the listed element. So for [first1, last1), the range starts with first1 (and includes it), but ends just before last1.

Assuming integers:

  • (0, 5) = 1, 2, 3, 4
  • (0, 5] = 1, 2, 3, 4, 5
  • [0, 5) = 0, 1, 2, 3, 4
  • [0, 5] = 0, 1, 2, 3, 4, 5

Call external javascript functions from java code

Let us say your jsfunctions.js file has a function "display" and this file is stored in C:/Scripts/Jsfunctions.js


var display = function(name) {
print("Hello, I am a Javascript display function",name);
return "display function return"

Now, in your java code, I would recommend you to use Java8 Nashorn. In your java class,


import javax.script.Invocable;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

class Test {
public void runDisplay() {
ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");
try {
  engine.eval(new FileReader("C:/Scripts/Jsfunctions.js"));
  Invocable invocable = (Invocable) engine;
  Object result;
  result = invocable.invokeFunction("display", helloWorld);
  } catch (FileNotFoundException | NoSuchMethodException | ScriptException e) {

Note: Get the absolute path of your javascript file and replace in FileReader() and run the java code. It should work.

How to get distinct results in hibernate with joins and row-based limiting (paging)?

A small improvement to @FishBoy's suggestion is to use the id projection, so you don't have to hard-code the identifier property name.


What is the difference between parseInt() and Number()?

parseInt() -> Parses a number to specified redix.

Number()-> Converts the specified value to its numeric equivalent or NaN if it fails to do so.

Hence for converting some non-numeric value to number we should always use Number() function.




Number("123ac") //NaN,as it is a non numeric string
parsInt("123ac") //123,it parse decimal number outof string

parseInt(true) //NaN

There are various corner case to parseInt() functions as it does redix conversion, hence we should avoid using parseInt() function for coersion purposes.

Now, to check weather the provided value is Numeric or not,we should use nativeisNaN() function

Multiple HttpPost method in Web API controller

public class Journal : ApiController
    public MyResult Get(journal id)
        return null;

public class Journal : ApiController

    public MyResult Get(journal id, publication id)
        return null;

I am not sure whether overloading get/post method violates the concept of restfull api,but it workds. If anyone could've enlighten on this matter. What if I have a uri as


so as you might seen my journal sort of aggregateroot, though i can define another controller for publication solely and pass id number of publication in my url however this gives much more sense. since my publication would not exist without journal itself.

Grep only the first match and stop

-m 1 means return the first match in any given file. But it will still continue to search in other files. Also, if there are two or more matched in the same line, all of them will be displayed.

You can use head -1 to solve this problem:

grep -o -a -m 1 -h -r "Pulsanti Operietur" /path/to/dir | head -1

explanation of each grep option:

-o, --only-matching, print only the matched part of the line (instead of the entire line)
-a, --text, process a binary file as if it were text
-m 1, --max-count, stop reading a file after 1 matching line
-h, --no-filename, suppress the prefixing of file names on output
-r, --recursive, read all files under a directory recursively

How to move Jenkins from one PC to another

This worked for me to move from Ubuntu 12.04 (Jenkins ver. 1.628) to Ubuntu 16.04 (Jenkins ver. 1.651.2). I first installed Jenkins from the repositories.

  1. Stop both Jenkins servers
  2. Copy JENKINS_HOME (e.g. /var/lib/jenkins) from the old server to the new one. From a console in the new server:

    rsync -av username@old-server-IP:/var/lib/jenkins/ /var/lib/jenkins/

  3. Start your new Jenkins server

You might not need this, but I had to

  • Manage Jenkins and Reload Configuration from Disk.
  • Disconnect and connect all the slaves again.
  • Check that in the Configure System > Jenkins Location, the Jenkins URL is correctly assigned to the new Jenkins server.

How to update only one field using Entity Framework?

I use ValueInjecter nuget to inject Binding Model into database Entity using following:

public async Task<IHttpActionResult> Add(CustomBindingModel model)
   var entity= await db.MyEntities.FindAsync(model.Id);
   if (entity== null) return NotFound();


   await db.SaveChangesAsync();
   return Ok();

Notice the usage of custom convention that doesn't update Properties if they're null from server.

ValueInjecter v3+

public class NoNullsInjection : LoopInjection
    protected override void SetValue(object source, object target, PropertyInfo sp, PropertyInfo tp)
        if (sp.GetValue(source) == null) return;
        base.SetValue(source, target, sp, tp);



Value Injecter V2

Lookup this answer


You won't know whether the property is intentionally cleared to null OR it just didn't have any value it. In other words, the property value can only be replaced with another value but not cleared.

How to add a hook to the application context initialization event?

Spring has some standard events which you can handle.

To do that, you must create and register a bean that implements the ApplicationListener interface, something like this:

package test.pack.age;

import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;

public class ApplicationListenerBean implements ApplicationListener {

    public void onApplicationEvent(ApplicationEvent event) {
        if (event instanceof ContextRefreshedEvent) {
            ApplicationContext applicationContext = ((ContextRefreshedEvent) event).getApplicationContext();
            // now you can do applicationContext.getBean(...)
            // ...

You then register this bean within your servlet.xml or applicationContext.xml file:

<bean id="eventListenerBean" class="test.pack.age.ApplicationListenerBean" />

and Spring will notify it when the application context is initialized.

In Spring 3 (if you are using this version), the ApplicationListener class is generic and you can declare the event type that you are interested in, and the event will be filtered accordingly. You can simplify a bit your bean code like this:

public class ApplicationListenerBean implements ApplicationListener<ContextRefreshedEvent> {

    public void onApplicationEvent(ContextRefreshedEvent event) {
        ApplicationContext applicationContext = event.getApplicationContext();
        // now you can do applicationContext.getBean(...)
        // ...

How do I determine the size of my array in C?

Size of an array in C:

int a[10];
size_t size_of_array = sizeof(a);      // Size of array a
int n = sizeof (a) / sizeof (a[0]);    // Number of elements in array a
size_t size_of_element = sizeof(a[0]); // Size of each element in array a                                          
                                       // Size of each element = size of type

Confirm Password with jQuery Validate

I'm implementing it in Play Framework and for me it worked like this:

1) Notice that I used data-rule-equalTo in input tag for the id inputPassword1. The code section of userform in my Modal:

<div class="form-group">
    <label for="pass1">@Messages("authentication.password")</label>
    <input class="form-control required" id="inputPassword1" placeholder="@Messages("authentication.password")" type="password" name="password" maxlength=10 minlength=5>
<div class="form-group">
    <label for="pass2">@Messages("authentication.password2")</label>
    <input class="form-control required" data-rule-equalTo="#inputPassword1" id="inputPassword2" placeholder="@Messages("authentication.password")" type="password" name="password2">

2)Since I used validator within a Modal

$(document).on("click", ".createUserModal", function () {
           rules: {
               firstName: "required",
               lastName: "required",
               nationalId: {
                   required: true,
               email: {
                   required: true,
                   email: true
               optradio: "required",
               password :{
                   required: true,
                   minlength: 5
               password2: {
                   required: true
           highlight: function (element) {
           unhighlight: function (element) {
           onsubmit: true


Hope it helps someone :).

How to use MySQL DECIMAL?

Although the answers above seems correct, just a simple explanation to give you an idea of how it works.

Suppose that your column is set to be DECIMAL(13,4). This means that the column will have a total size of 13 digits where 4 of these will be used for precision representation.

So, in summary, for that column you would have a max value of: 999999999.9999

iOS8 Beta Ad-Hoc App Download (itms-services)

Specify a 'display-image' and 'full-size-image' as described here:

iOS8 requires these images

multiprocessing.Pool: When to use apply, apply_async or map?

Back in the old days of Python, to call a function with arbitrary arguments, you would use apply:


apply still exists in Python2.7 though not in Python3, and is generally not used anymore. Nowadays,


is preferred. The multiprocessing.Pool modules tries to provide a similar interface.

Pool.apply is like Python apply, except that the function call is performed in a separate process. Pool.apply blocks until the function is completed.

Pool.apply_async is also like Python's built-in apply, except that the call returns immediately instead of waiting for the result. An AsyncResult object is returned. You call its get() method to retrieve the result of the function call. The get() method blocks until the function is completed. Thus, pool.apply(func, args, kwargs) is equivalent to pool.apply_async(func, args, kwargs).get().

In contrast to Pool.apply, the Pool.apply_async method also has a callback which, if supplied, is called when the function is complete. This can be used instead of calling get().

For example:

import multiprocessing as mp
import time

def foo_pool(x):
    return x*x

result_list = []
def log_result(result):
    # This is called whenever foo_pool(i) returns a result.
    # result_list is modified only by the main process, not the pool workers.

def apply_async_with_callback():
    pool = mp.Pool()
    for i in range(10):
        pool.apply_async(foo_pool, args = (i, ), callback = log_result)

if __name__ == '__main__':

may yield a result such as

[1, 0, 4, 9, 25, 16, 49, 36, 81, 64]

Notice, unlike, the order of the results may not correspond to the order in which the pool.apply_async calls were made.

So, if you need to run a function in a separate process, but want the current process to block until that function returns, use Pool.apply. Like Pool.apply, blocks until the complete result is returned.

If you want the Pool of worker processes to perform many function calls asynchronously, use Pool.apply_async. The order of the results is not guaranteed to be the same as the order of the calls to Pool.apply_async.

Notice also that you could call a number of different functions with Pool.apply_async (not all calls need to use the same function).

In contrast, applies the same function to many arguments. However, unlike Pool.apply_async, the results are returned in an order corresponding to the order of the arguments.

Is there a way to access the "previous row" value in a SELECT statement?

select t2.col from (
select col,MAX(ID) id from 
select ROW_NUMBER() over(PARTITION by col order by col) id ,col from testtab t1) as t1
group by col) as t2

What is the --save option for npm install?

You can also use -S, -D or -P which are equivalent of saving the package to an app dependency, a dev dependency or prod dependency. See more NPM shortcuts below:

-v: --version
-h, -?, --help, -H: --usage
-s, --silent: --loglevel silent
-q, --quiet: --loglevel warn
-d: --loglevel info
-dd, --verbose: --loglevel verbose
-ddd: --loglevel silly
-g: --global
-C: --prefix
-l: --long
-m: --message
-p, --porcelain: --parseable
-reg: --registry
-f: --force
-desc: --description
-S: --save
-P: --save-prod
-D: --save-dev
-O: --save-optional
-B: --save-bundle
-E: --save-exact
-y: --yes
-n: --yes false
ll and la commands: ls --long

This list of shortcuts can be obtained by running the following command:

$ npm help 7 config

How do I print debug messages in the Google Chrome JavaScript Console?

Simple Internet Explorer 7 and below shim that preserves line numbering for other browsers:

/* Console shim */
(function () {
    var f = function () {};
    if (!window.console) {
        window.console = {
            log:f, info:f, warn:f, debug:f, error:f

XPath test if node value is number

I've been dealing with 01 - which is a numeric.

string(number($v)) != string($v) makes the segregation

jQuery .val change doesn't change input value

For me the problem was that changing the value for this field didn`t work:


None of the solutions above worked for me so I investigated further and found:

According to DOM Level 2 Event Specification: The change event occurs when a control loses the input focus and its value has been modified since gaining focus. That means that change event is designed to fire on change by user interaction. Programmatic changes do not cause this event to be fired.

The solution was to add the trigger function and cause it to trigger change event like this:


Which SchemaType in Mongoose is Best for Timestamp?

In case you want custom names for your createdAt and updatedAt

const mongoose = require('mongoose');  
const { Schema } = mongoose;

const schemaOptions = {
  timestamps: { createdAt: 'created_at', updatedAt: 'updated_at' },

const mySchema = new Schema({ name: String }, schemaOptions);

C/C++ switch case with string

You can use enumeration and a map, so your string will become the key and enum value is value for that key.

How to initialize List<String> object in Java?

List is an Interface . You cant use List to initialize it.

  List<String> supplierNames = new ArrayList<String>();

These are the some of List impelemented classes,

ArrayList, LinkedList, Vector

You could use any of this as per your requirement. These each classes have its own features.

How to make a Python script run like a service or daemon in Linux

Assuming that you would really want your loop to run 24/7 as a background service

For a solution that doesn't involve injecting your code with libraries, you can simply create a service template, since you are using linux:

Description = <Your service description here>
After = # Assuming you want to start after network interfaces are made available
Type = simple
ExecStart = python <Path of the script you want to run>
User = # User to run the script as
Group = # Group to run the script as
Restart = on-failure # Restart when there are errors
SyslogIdentifier = <Name of logs for the service>
RestartSec = 5
TimeoutStartSec = infinity
WantedBy = # Make it accessible to other users

Place that file in your daemon service folder (usually /etc/systemd/system/), in a *.service file, and install it using the following systemctl commands (will likely require sudo privileges):

systemctl enable <service file name without .service extension>

systemctl daemon-reload

systemctl start <service file name without .service extension>

You can then check that your service is running by using the command:

systemctl | grep running

Support for ES6 in Internet Explorer 11

The statement from Microsoft regarding the end of Internet Explorer 11 support mentions that it will continue to receive security updates, compatibility fixes, and technical support until its end of life. The wording of this statement leads me to believe that Microsoft has no plans to continue adding features to Internet Explorer 11, and instead will be focusing on Edge.

If you require ES6 features in Internet Explorer 11, check out a transpiler such as Babel.

Make Bootstrap Popover Appear/Disappear on Hover instead of Click

Set the trigger option of the popover to hover instead of click, which is the default one.

This can be done using either data-* attributes in the markup:

<a id="popover" data-trigger="hover">Popover</a>

Or with an initialization option:

$("#popover").popover({ trigger: "hover" });

Here's a DEMO.

Is it possible to get a list of files under a directory of a website? How?

Yes, you can, but you need a few tools first. You need to know a little about basic coding, FTP clients, port scanners and brute force tools, if it has a .htaccess file.

If not just try tgp.linkurl.htm or html, ie default.html, www/home/siteurl/web/, or wap /index/ default /includes/ main/ files/ images/ pics/ vids/, could be possible file locations on the server, so try all of them so www/home/siteurl/web/includes/.htaccess or default.html. You'll hit a file after a few tries then work off that. Yahoo has a site file viewer too: you can try to scan sites file indexes.

Alternatively, try brutus aet, trin00, trinity.x, or whiteshark airtool to crack the site's FTP login (but it's illegal and I do not condone that).

java.math.BigInteger cannot be cast to java.lang.Integer

You can use:

Integer grandChildCount = ((BigInteger) result[1]).intValue();

Or perhaps cast to Number to cover both Integer and BigInteger values.

Pytorch tensor to numpy array

There are 4 dimensions of the tensor you want to convert.

[:, ::-1, :, :] 

: means that the first dimension should be copied as it is and converted, same goes for the third and fourth dimension.

::-1 means that for the second axes it reverses the the axes

How to copy from CSV file to PostgreSQL table with headers in CSV file?

I have been using this function for a while with no problems. You just need to provide the number columns there are in the csv file, and it will take the header names from the first row and create the table for you:

create or replace function data.load_csv_file
        target_table  text, -- name of the table that will be created
        csv_file_path text,
        col_count     integer

    returns void

as $$

    iter      integer; -- dummy integer to iterate columns with
    col       text; -- to keep column names in each iteration
    col_first text; -- first column name, e.g., top left corner on a csv file or spreadsheet

    set schema 'data';

    create table temp_table ();

    -- add just enough number of columns
    for iter in 1..col_count
        execute format ('alter table temp_table add column col_%s text;', iter);
    end loop;

    -- copy the data from csv file
    execute format ('copy temp_table from %L with delimiter '','' quote ''"'' csv ', csv_file_path);

    iter := 1;
    col_first := (select col_1
                  from temp_table
                  limit 1);

    -- update the column names based on the first row which has the column names
    for col in execute format ('select unnest(string_to_array(trim(temp_table::text, ''()''), '','')) from temp_table where col_1 = %L', col_first)
        execute format ('alter table temp_table rename column col_%s to %s', iter, col);
        iter := iter + 1;
    end loop;

    -- delete the columns row // using quote_ident or %I does not work here!?
    execute format ('delete from temp_table where %s = %L', col_first, col_first);

    -- change the temp table name to the name given as parameter, if not blank
    if length (target_table) > 0 then
        execute format ('alter table temp_table rename to %I', target_table);
    end if;

$$ language plpgsql;

How does the data-toggle attribute work? (What's its API?)

The data-toggle attribute simple tell Bootstrap what exactly to do by giving it the name of the toggle action it is about to perform on a target element. If you specify collapse. It means bootstrap will collapse or uncollapse the element pointed by data-target of the action you clicked

Note: the target element must have the appropriate class for bootstrap to carry out the action

Source action:
data-toggle = collapse //type of toggle
data-target = #myDiv

class=collapse //I can collapse

This is same for other type of toggle actions like tab, modal, dropdown

jquery live hover

jQuery 1.4.1 now supports "hover" for live() events, but only with one event handler function:

$("table tr").live("hover",

function () {


Alternatively, you can provide two functions, one for mouseenter and one for mouseleave:

$("table tr").live({
    mouseenter: function () {

    mouseleave: function () {


Which is the best Linux C/C++ debugger (or front-end to gdb) to help teaching programming?

You could try using Insight a graphical front-end for gdb written by Red Hat Or if you use GNOME desktop environment, you can also try Nemiver.

How to send a PUT/DELETE request in jQuery?

You could use the ajax method:

    url: '/script.cgi',
    type: 'DELETE',
    success: function(result) {
        // Do something with the result

Flexbox: center horizontally and vertically




<div class="flex-container">
  <div class="rows">

    <div class="row">
      <span class="flex-item">1</span>
    <div class="row">
      <span class="flex-item">2</span>
    <div class="row">
      <span class="flex-item">3</span>
    <div class="row">
      <span class="flex-item">4</span>



html, body {
  height: 100%;  

.flex-container {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100%;

.rows {
  display: flex;
  flex-direction: column;

where flex-container div is used to center vertically and horizontally your rows div, and rows div is used to group your "items" and ordering them in a column based one.

String to char array Java

A string to char array is as simple as

String str = "someString"; 
char[] charArray = str.toCharArray();

Can you explain a little more on what you are trying to do?

* Update *

if I am understanding your new comment, you can use a byte array and example is provided.

byte[] bytes = ByteBuffer.allocate(4).putInt(1695609641).array();

for (byte b : bytes) {
   System.out.format("0x%x ", b);

With the following output

0x65 0x10 0xf3 0x29

Insert a string at a specific index

Here is a method I wrote that behaves like all other programming languages:

String.prototype.insert = function(index, string) {
  if (index > 0) {
    return this.substring(0, index) + string + this.substr(index);

  return string + this;

//Example of use:
var something = "How you?";
something = something.insert(3, " are");


Bash loop ping successful

If you use the -o option, Mac OS X’s ping will exit after receiving one reply packet.

Further reading:

EDIT: paxdiablo makes a very good point about using ping’s exit status to your advantage. I would do something like:

#!/usr/bin/env bash
echo 'Begin ping'
if ping -oc 100000 > /dev/null; then
    echo $(say 'timeout')
    echo $(say 'the Internet is back up')

ping will send up to 100,000 packets and then exit with a failure status—unless it receives one reply packet, in which case it exits with a success status. The if will then execute the appropriate statement.

How do I perform query filtering in django templates

This can be solved with an assignment tag:

from django import template

register = template.Library()

def query(qs, **kwargs):
    """ template tag which allows queryset filtering. Usage:
          {% query books author=author as mybooks %}
          {% for book in mybooks %}
          {% endfor %}
    return qs.filter(**kwargs)

Where's the IE7/8/9/10-emulator in IE11 dev tools?

I posted an answer to this already when someone else asked the same question (see How to bring back "Browser mode" in IE11?).

Read my answer there for a fuller explaination, but in short:

  • They removed it deliberately, because compat mode is not actually really very good for testing compatibility.

  • If you really want to test for compatibility with any given version of IE, you need to test in a real copy of that IE version. MS provide free VMs on for you to use for this purpose.

  • The only way to get compat mode in IE11 is to set the X-UA-Compatible header. When you have this and the site defaults to compat mode, you will be able to set the mode in dev tools, but only between edge or the specified compat mode; other modes will still not be available.

How can I see the current value of my $PATH variable on OS X?

You need to use the command echo $PATH to display the PATH variable or you can just execute set or env to display all of your environment variables.

By typing $PATH you tried to run your PATH variable contents as a command name.

Bash displayed the contents of your path any way. Based on your output the following directories will be searched in the following order:


To me this list appears to be complete.

MySQL JOIN the most recent row only?

It's a good idea that logging actual data into "customer_data" table. With this data you can select all data from "customer_data" table as you wish.

What is the difference between fastcgi and fpm?

FPM is a process manager to manage the FastCGI SAPI (Server API) in PHP.

Basically, it replaces the need for something like SpawnFCGI. It spawns the FastCGI children adaptively (meaning launching more if the current load requires it).

Otherwise, there's not much operating difference between it and FastCGI (The request pipeline from start of request to end is the same). It's just there to make implementing it easier.

Want custom title / image / description in facebook share link from a flash app

You can't, it just doesn't support it.

I have to ask, why those calculations need to happen Only inside the flash app?

You have to be navigating to an URL that clearly relates to the metadata you get from the flash app. Otherwise how would the flash app know to get the values depending on the URL you hit.

Options are:

  • calculate on the page: When serving the page you need to do those same calculations on the server and send the title, etc on the page metadata.
  • send metadata in the query string to your site: If you really must keep the calculation off the server, an alternative trick would be to explicitly set the metadata in the URL the users click to get to your site from Facebook. When processing the page, you just copy it back in the metadata sections (don't forget to encode appropriately). That is clearly limited because of the url size restrictions.
  • send the calculation results in the query string to your site: if those calculations just give you a couple numbers that are used in the metadata, you could include just that in the query string of the URL the users click back to your site. That's more likely to not give you problems with URL sizes.


Why is this upvoted? It's wrong. You CAN - it IS supported to add custom title, description and images to your share. I do it all the time. – Dustin Fineout 3 hours ago

The OP very clearly stated that he already knew you could serve that from a page, but wanted to pass the values directly to facebook (not through the target page).

Besides, note that I gave 3 different options to work around the issue, one of which is what you posted as an answer later. Your option isn't how the OP was trying to do it, its just a workaround because of facebook restrictions.

Finally, just as I did, you should mention that particular solution is flawed because you can easily hit the URL size restriction.

PostgreSQL: export resulting data from SQL query to Excel/CSV

Example with Unix-style file name:

COPY (SELECT * FROM tbl) TO '/var/lib/postgres/myfile1.csv' format csv;

Read the manual about COPY (link to version 8.2).
You have to use an absolute path for the target file. Be sure to double quote file names with spaces. Example for MS Windows:

TO E'"C:\\Documents and Settings\\Tech\Desktop\\myfile1.csv"' format csv;

In PostgreSQL 8.2, with standard_conforming_strings = off per default, you need to double backslashes, because \ is a special character and interpreted by PostgreSQL. Works in any version. It's all in the fine manual:


 The absolute path name of the input or output file. Windows users might need to use an E'' string and double backslashes used as path separators.

Or the modern syntax with standard_conforming_strings = on (default since Postgres 9.1):

COPY tbl  -- short for (SELECT * FROM tbl)
TO '"C:\Documents and Settings\Tech\Desktop\myfile1.csv"' (format csv);

Or you can also use forward slashes for filenames under Windows.

An alternative is to use the meta-command \copy of the default terminal client psql.

You can also use a GUI like pgadmin and copy / paste from the result grid to Excel for small queries.

Closely related answer:

Similar solution for MySQL:

CSS Selector that applies to elements with two classes

Chain both class selectors (without a space in between): {
    /* Styles for element(s) with foo AND bar classes */

If you still have to deal with ancient browsers like IE6, be aware that it doesn't read chained class selectors correctly: it'll only read the last class selector (.bar in this case) instead, regardless of what other classes you list.

To illustrate how other browsers and IE6 interpret this, consider this CSS:

* {
    color: black;
} {
    color: red;

Output on supported browsers is:

<div class="foo">Hello Foo</div>       <!-- Not selected, black text [1] -->
<div class="foo bar">Hello World</div> <!-- Selected, red text [2] -->
<div class="bar">Hello Bar</div>       <!-- Not selected, black text [3] -->

Output on IE6 is:

<div class="foo">Hello Foo</div>       <!-- Not selected, black text [1] -->
<div class="foo bar">Hello World</div> <!-- Selected, red text [2] -->
<div class="bar">Hello Bar</div>       <!-- Selected, red text [2] -->


  • Supported browsers:
    1. Not selected as this element only has class foo.
    2. Selected as this element has both classes foo and bar.
    3. Not selected as this element only has class bar.

  • IE6:
    1. Not selected as this element doesn't have class bar.
    2. Selected as this element has class bar, regardless of any other classes listed.

How do I call a Django function on button click?

The following answer could be helpful for the first part of your question:

Django: How can I call a view function from template?

Reference to a non-shared member requires an object reference occurs when calling public sub

Go to the Declaration of the desired object and mark it Shared.

Friend Shared WithEvents MyGridCustomer As Janus.Windows.GridEX.GridEX

How to get a thread and heap dump of a Java process on Windows that's not running in a console

Maybe jcmd?

Jcmd utility is used to send diagnostic command requests to the JVM, where these requests are useful for controlling Java Flight Recordings, troubleshoot, and diagnose JVM and Java Applications.

The jcmd tool was introduced with Oracle's Java 7 and is particularly useful in troubleshooting issues with JVM applications by using it to identify Java processes' IDs (akin to jps), acquiring heap dumps (akin to jmap), acquiring thread dumps (akin to jstack), viewing virtual machine characteristics such as system properties and command-line flags (akin to jinfo), and acquiring garbage collection statistics (akin to jstat). The jcmd tool has been called "a swiss-army knife for investigating and resolving issues with your JVM application" and a "hidden gem."

Here’s the process you’ll need to use in invoking the jcmd:

  1. Go to jcmd <pid> GC.heap_dump <file-path>
  2. In which
  3. pid: is a Java Process Id, for which the heap dump will be captured Also, the
  4. file-path: is a file path in which the heap dump is be printed.

Check it out for more information about taking Java heap dump.

Ubuntu: Using curl to download an image

For those who don't have nor want to install wget, curl -O (capital "o", not a zero) will do the same thing as wget. E.g. my old netbook doesn't have wget, and is a 2.68 MB install that I don't need.

curl -O

Fastest way to implode an associative array with keys

You can use http_build_query() to do that.

Generates a URL-encoded query string from the associative (or indexed) array provided.

Form inside a form, is that alright?

It's not valid XHTML to have to have nested forms. However, you can use multiple submit buttons and use a serverside script to run different codes depending on which button the users has clicked.

Close all infowindows in Google Maps API v3

I have a sample of my code that maybe can help. I had set only one infowindow object at global scope. Then use setContent() to set the content before show it.

  let map;
  let infowindow;
  let dataArr = [
      pos:{lat: -34.397, lng: 150.644},
      content: 'First marker'
      pos:{lat: -34.340, lng: 150.415},
      content: 'Second marker'

  function initMap() {
    map = new google.maps.Map(document.getElementById('map'), {
      center: {lat: -34.397, lng: 150.644},
      zoom: 8
    // Set infowindow object to global varible
    infowindow = new google.maps.InfoWindow();

  function loadMarker(){
    dataArr.forEach((obj, i)=>{
      let marker = new google.maps.Marker({
        position: obj.pos,
        map: map
      marker.addListener('click', function() {
        infowindow.setContent(`<div> ${obj.content} </div>`), marker);

How to convert 2D float numpy array to 2D int numpy array?

you can use np.int_:

>>> x = np.array([[1.0, 2.3], [1.3, 2.9]])
>>> x
array([[ 1. ,  2.3],
       [ 1.3,  2.9]])
>>> np.int_(x)
array([[1, 2],
       [1, 2]])

Why can't radio buttons be "readonly"?

I've faked readonly on a radio button by disabling only the un-checked radio buttons. It keeps the user from selecting a different value, and the checked value will always post on submit.

Using jQuery to make readonly:

$(':radio:not(:checked)').attr('disabled', true);

This approach also worked for making a select list readonly, except that you'll need to disable each un-selected option.

regular expression for DOT

. matches any character so needs escaping i.e. \., or \\. within a Java string (because \ itself has special meaning within Java strings.)

You can then use \.\. or \.{2} to match exactly 2 dots.

Xcode warning: "Multiple build commands for output file"

This is easily caused when you add git based subprojects. Xcode isn't smart enough to ignore the .git subfolder even though you can't see it from finder, so it will get very confused that there are multiple files named "master" or "exclude", (standard git repo files). With Xcode4, go to the project (root of the left tree) then click your app target and expand "Copy Bundle Resources", then remove all the references to .git, you shouldn't need them baked into your app anyway.

How to take MySQL database backup using MySQL Workbench?

In Window in new version you can export like this

enter image description here enter image description here

enter image description here

How to directly initialize a HashMap (in a literal way)?

You can use Streams In Java 8 (this is exmaple of Set):

public void whenInitializeUnmodifiableSetWithDoubleBrace_containsElements() {
    Set<String> countries = Stream.of("India", "USSR", "USA")
      .collect(collectingAndThen(toSet(), Collections::unmodifiableSet));



How can I show three columns per row?

Even though the above answer appears to be correct, I wanted to add a (hopefully) more readable example that also stays in 3 columns form at different widths:

.flex-row-container {_x000D_
    background: #aaa;_x000D_
    display: flex;_x000D_
    flex-wrap: wrap;_x000D_
    align-items: center;_x000D_
    justify-content: center;_x000D_
.flex-row-container > .flex-row-item {_x000D_
    flex: 1 1 30%; /*grow | shrink | basis */_x000D_
    height: 100px;_x000D_
.flex-row-item {_x000D_
  background-color: #fff4e6;_x000D_
  border: 1px solid #f76707;_x000D_
<div class="flex-row-container">_x000D_
  <div class="flex-row-item">1</div>_x000D_
  <div class="flex-row-item">2</div>_x000D_
  <div class="flex-row-item">3</div>_x000D_
  <div class="flex-row-item">4</div>_x000D_
  <div class="flex-row-item">5</div>_x000D_
  <div class="flex-row-item">6</div>_x000D_

Hope this helps someone else.

Maven Unable to locate the Javac Compiler in:

Had the same problem, but in my case, the directory eclipse pointed the JRE was the JDK. So, i searched for that tools.jar and was there.

I did

  • Java Build Path >> Libraries
  • JRE System Lybrary >> Edit
  • Installed JREs >> click on my jdk >> edit
  • Add External Jars >> tools.jar

And then compiled fine

How to run console application from Windows Service?

Running in Windows Services any application like for example ".exe" is weird to do because the algorithm is not that effective.

Html.DropDownList - Disabled/Readonly

I just do this and call it a day

Model.Id > -1 ? Html.EnumDropDownListFor(m => m.Property, new { disabled = "disabled" }) : Html.EnumDropDownListFor(m => m.Property)

String in function parameter


is similar to

char *s = "MyString";

"MyString" is in both cases a string literal and in both cases the string is unmodifiable.


passes the address of a string literal to function as an argument.

How do you check what version of SQL Server for a database using TSQL?


SELECT @@MICROSOFTVERSION / 0x01000000 AS MajorVersionNumber

For more information see: Querying for version/edition info

How to automatically generate unique id in SQL like UID12345678?

If you want to add the id manually you can use,

PadLeft() or String.Format() method.

string id;
char x='0';
id=id.PadLeft(6, x);
//Six character string id with left 0s e.g 000012

int id;
//Integer length of 6 with the id. e.g 000012

Then you can append this with UID.

Get Date Object In UTC format in Java

In java 8 , It's really easy to get timestamp in UTC by using java 8 java.time.Instant library :;

That few word of code will return the UTC Timestamp.

What does "both" mean in <div style="clear:both">

Both means "every item in a set of two things". The two things being "left" and "right"

How to display an IFRAME inside a jQuery UI dialog

Although this is a old post, I have spent 3 hours to fix my issue and I think this might help someone in future.

Here is my jquery-dialog hack to show html content inside an <iframe> :

let modalProperties = {autoOpen: true, width: 900, height: 600, modal: true, title: 'Modal Title'};
let modalHtmlContent = '<div>My Content First div</div><div>My Content Second div</div>';

// create wrapper iframe
let wrapperIframe = $('<iframe src="" frameborder="0" style="width:100%; height:100%;"></iframe>');

// create jquery dialog by a 'div' with 'iframe' appended

// insert html content to iframe 'body'
let wrapperIframeDocument = wrapperIframe[0].contentDocument;
let wrapperIframeBody = $('body', wrapperIframeDocument);

jsfiddle demo

How do I merge changes to a single file, rather than merging commits?

Here's what I do in these situations. It's a kludge but it works just fine for me.

  1. Create another branch based off of your working branch.
  2. git pull/git merge the revision (SHA1) which contains the file you want to copy. So this will merge all of your changes, but we are only using this branch to grab the one file.
  3. Fix up any Conflicts etc. investigate your file.
  4. checkout your working branch
  5. Checkout the file commited from your merge.
  6. Commit it.

I tried patching and my situation was too ugly for it. So in short it would look like this:

Working Branch: A Experimental Branch: B (contains file.txt which has changes I want to fold in.)

git checkout A

Create new branch based on A:

git checkout -b tempAB

Merge B into tempAB

git merge B

Copy the sha1 hash of the merge:

git log

commit 8dad944210dfb901695975886737dc35614fa94e
Merge: ea3aec1 0f76e61
Author: matthewe <[email protected]>
Date:   Wed Oct 3 15:13:24 2012 -0700

Merge branch 'B' into tempAB

Checkout your working branch:

git checkout A

Checkout your fixed-up file:

git checkout 7e65b5a52e5f8b1979d75dffbbe4f7ee7dad5017 file.txt

And there you should have it. Commit your result.

How do I export html table data as .csv file?

I was able to use the answer outlined here: Export to CSV using jQuery and html and added in a modification to make it work in IE and another modification mentioned in the comments to grab the thead from the table.

function exportTableToCSV($table, filename) {

    var $rows = $table.find('tr:has(td),tr:has(th)'),

        // Temporary delimiter characters unlikely to be typed by keyboard
        // This is to avoid accidentally splitting the actual contents
        tmpColDelim = String.fromCharCode(11), // vertical tab character
        tmpRowDelim = String.fromCharCode(0), // null character

        // actual delimiter characters for CSV format
        colDelim = '","',
        rowDelim = '"\r\n"',

        // Grab text from table into CSV formatted string
        csv = '"' + $ (i, row) {
            var $row = $(row), $cols = $row.find('td,th');

            return $ (j, col) {
                var $col = $(col), text = $col.text();

                return text.replace(/"/g, '""'); // escape double quotes


            .split(tmpColDelim).join(colDelim) + '"',

        // Data URI
        csvData = 'data:application/csv;charset=utf-8,' + encodeURIComponent(csv);


        if (window.navigator.msSaveBlob) { // IE 10+
            //alert('IE' + csv);
            window.navigator.msSaveOrOpenBlob(new Blob([csv], {type: "text/plain;charset=utf-8;"}), "csvname.csv")
        else {
            $(this).attr({ 'download': filename, 'href': csvData, 'target': '_blank' }); 

// This must be a hyperlink
$("#xx").on('click', function (event) {

    exportTableToCSV.apply(this, [$('#projectSpreadsheet'), 'export.csv']);

    // IF CSV, don't do event.preventDefault() or return false
    // We actually need this to be a typical hyperlink

With my link looking like this...

<a href="#" id="xx" style="text-decoration:none;color:#000;background-color:#ddd;border:1px solid #ccc;padding:8px;">Export Table data into Excel</a>


Using Java 8 to convert a list of objects into a string obtained from the toString() method

Just in case anyone is trying to do this without java 8, there is a pretty good trick. List.toString() already returns a collection that looks like this:


Depending on your specific requirements, this can be post-processed to whatever you want as long as your list items don't contain [] or , .

For instance:


or if your data might contain square brackets this:

String s=list.toString();
s = s.substring(1,s.length()-1) 

will get you a pretty reasonable output.

One array item on each line can be created like this:


I used this technique to make html tooltips from a list in a small app, with something like:


If you have an array then start with Arrays.asList(list).toString() instead

I'll totally own the fact that this is not optimal, but it's not as inefficient as you might think and is pretty straightforward to read and understand. It is, however, quite inflexible--in particular don't try to separate the elements with replaceAll if your data might contain commas and use the substring version if you have square brackets in your data, but for an array of numbers it's pretty much perfect.

How to increase time in web.config for executing sql query

I think you can't increase the time for query execution, but you need to increase the timeout for the request.

Execution Timeout Specifies the maximum number of seconds that a request is allowed to execute before being automatically shut down by ASP.NET. (Default time is 110 seconds.)

For Details, please have a look at

You can do in the web.config. e.g

<httpRuntime maxRequestLength="2097152" executionTimeout="600" />

How to compile LEX/YACC files on Windows?

Go for the full installation of Git for windows (with Unix tool), and bison and flex would come with it in the bin folder.

Remove characters from a String in Java

Strings are immutable, so when you manipulate them you need to assign the result to a string:

String id = fileR.getName();
id = id.replace(".xml", ""); // this is the key line

twitter-bootstrap: how to get rid of underlined button text when hovering over a btn-group within an <a>-tag?

just use bootstrap class "btn" in the link it will remove underline on hover

What are the advantages and disadvantages of recursion?

Any algorithm implemented using recursion can also be implemented using iteration.

Why not to use recursion

  1. It is usually slower due to the overhead of maintaining the stack.
  2. It usually uses more memory for the stack.

Why to use recursion

  1. Recursion adds clarity and (sometimes) reduces the time needed to write and debug code (but doesn't necessarily reduce space requirements or speed of execution).
  2. Reduces time complexity.
  3. Performs better in solving problems based on tree structures.

For example, the Tower of Hanoi problem is more easily solved using recursion as opposed to iteration.

How to normalize an array in NumPy to a unit vector?

If you're using scikit-learn you can use sklearn.preprocessing.normalize:

import numpy as np
from sklearn.preprocessing import normalize

x = np.random.rand(1000)*10
norm1 = x / np.linalg.norm(x)
norm2 = normalize(x[:,np.newaxis], axis=0).ravel()
print np.all(norm1 == norm2)
# True

tell pip to install the dependencies of packages listed in a requirement file

simplifily, use:

pip install -r requirement.txt

it can install all listed in requirement file.

jQuery - prevent default, then continue default


Attach a handler to an event for the elements. The handler is executed at most once per element per event type

$('form').one('submit', function(e) {
    // do your things ...

    // and when you done:

The use of one prevent also infinite loop because this custom submit event is detatched after the first submit.

How to configure heroku application DNS to Godaddy Domain?

There are 2 steps you need to perform,

  1. Add the custom domains addon and add the domain your going to use, eg to your application
  2. Go to your domain registrar control panel and set to be a CNAME entry to assuming you are using the CEDAR stack.
  3. There is a third step if you want to use a naked domain, eg when you would have to add the IP addresses of the Heroku load balancers to your DNS for

You can read more about this at

At a guess you've missed out the first step perhaps?

UPDATE: Following the announcement of Bamboo's EOL being retired (September 2014) for Bamboo applications so these should also now use the mapping now as well.

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

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

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

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

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

As simple as that

How to set image button backgroundimage for different state?

@ingsaurabh's answer is the way to go if you are using an onClick even. However, if you are using an onTouch event, you can select the different backgrounds (still the same as @ingsaurabh's example) by using view.setPressed().

See the following for more details: "Press and hold" button on Android needs to change states (custom XML selector) using onTouchListener

AngularJS - Access to child scope

One possible workaround is inject the child controller in the parent controller using a init function.

Possible implementation:

<div ng-controller="ParentController as parentCtrl">

    <div ng-controller="ChildController as childCtrl" 

Where in ChildController you have :

    ['$scope', '$rootScope', function ($scope, $rootScope) {
    this.init = function() {
         $scope.parentCtrl.childCtrl = $scope.childCtrl;
         $scope.childCtrl.test = 'aaaa';


So now in the ParentController you can use :

    ['$scope', '$rootScope', 'service', function ($scope, $rootScope, service) { = function() {{
            a:  $scope.parentCtrl.ChildCtrl.test


To work properly you have to use the directive ng-controller and rename each controller using as like i did in the html eg.

Use the chrome plugin ng-inspector during the process. It's going to help you to understand the tree.

Bootstrap Datepicker - Months and Years Only

I'm using version 2(supports both bootstrap v2 and v3) and for me this works:

$("#datepicker").datepicker( {
    format: "mm/yyyy",
    startView: "year", 
    minView: "year"

How to create a data file for gnuplot?

plot "data.txt" using 1:2 with lines 

works for me. Do you actually have blank lines in your data file? That will cause an empty plot. Can you see a plot without data? Like plot x*x. If not, then your terminal might not be set up correctly.

Operand type clash: int is incompatible with date + The INSERT statement conflicted with the FOREIGN KEY constraint

Try wrapping your dates in single quotes, like this:


It should be able to parse the date this way.

jQuery - Create hidden form element on the fly


To answer your second question:

    type: 'hidden',
    id: 'foo',
    name: 'bar'

How to install numpy on windows using pip install?

As of March 2016, pip install numpy works on Windows without a Fortran compiler. See here.

pip install scipy still tries to use a compiler.

July 2018: mojoken reports pip install scipy working on Windows without a Fortran compiler.

Why would one omit the close tag?

Sending headers earlier than the normal course may have far reaching consequences. Below are just a few of them that happened to come to my mind at the moment:

  1. While current PHP releases may have output buffering on, the actual production servers you will be deploying your code on are far more important than any development or testing machines. And they do not always tend to follow latest PHP trends immediately.

  2. You may have headaches over inexplicable functionality loss. Say, you are implementing some kind payment gateway, and redirect user to a specific URL after successful confirmation by the payment processor. If some kind of PHP error, even a warning, or an excess line ending happens, the payment may remain unprocessed and the user may still seem unbilled. This is also one of the reasons why needless redirection is evil and if redirection is to be used, it must be used with caution.

  3. You may get "Page loading canceled" type of errors in Internet Explorer, even in the most recent versions. This is because an AJAX response/json include contains something that it shouldn't contain, because of the excess line endings in some PHP files, just as I've encountered a few days ago.

  4. If you have some file downloads in your app, they can break too, because of this. And you may not notice it, even after years, since the specific breaking habit of a download depends on the server, the browser, the type and content of the file (and possibly some other factors I don't want to bore you with).

  5. Finally, many PHP frameworks including Symfony, Zend and Laravel (there is no mention of this in the coding guidelines but it follows the suit) and the PSR-2 standard (item 2.2) require omission of the closing tag. PHP manual itself (1,2), Wordpress, Drupal and many other PHP software I guess, advise to do so. If you simply make a habit of following the standard (and setup PHP-CS-Fixer for your code) you can forget the issue. Otherwise you will always need to keep the issue in your mind.

Bonus: a few gotchas (actually currently one) related to these 2 characters:

  1. Even some well-known libraries may contain excess line endings after ?>. An example is Smarty, even the most recent versions of both 2.* and 3.* branch have this. So, as always, watch for third party code. Bonus in bonus: A regex for deleting needless PHP endings: replace (\s*\?>\s*)$ with empty text in all files that contain PHP code.

Java sending and receiving file (byte[]) over sockets

To avoid the limitation of the file size , which can cause the Exception java.lang.OutOfMemoryError to be thrown when creating an array of the file size byte[] bytes = new byte[(int) length];, instead we could do

    byte[] bytearray = new byte[1024*16];
    FileInputStream fis = null;
    try {

        fis = new FileInputStream(file);
        OutputStream output= socket.getOututStream();
        BufferedInputStream bis = new BufferedInputStream(fis);

        int readLength = -1;
        while ((readLength = > 0) {
            output.write(bytearray, 0, readLength);

    catch(Exception ex ){

    } //Excuse the poor exception handling...

vertical & horizontal lines in matplotlib

This may be a common problem for new users of Matplotlib to draw vertical and horizontal lines. In order to understand this problem, you should be aware that different coordinate systems exist in Matplotlib.

The method axhline and axvline are used to draw lines at the axes coordinate. In this coordinate system, coordinate for the bottom left point is (0,0), while the coordinate for the top right point is (1,1), regardless of the data range of your plot. Both the parameter xmin and xmax are in the range [0,1].

On the other hand, method hlines and vlines are used to draw lines at the data coordinate. The range for xmin and xmax are the in the range of data limit of x axis.

Let's take a concrete example,

import matplotlib.pyplot as plt
import numpy as np

x = np.linspace(0, 5, 100)
y = np.sin(x)

fig, ax = plt.subplots()

ax.plot(x, y)
ax.axhline(y=0.5, xmin=0.0, xmax=1.0, color='r')
ax.hlines(y=0.6, xmin=0.0, xmax=1.0, color='b')

It will produce the following plot: enter image description here

The value for xmin and xmax are the same for the axhline and hlines method. But the length of produced line is different.

How to use if statements in LESS

I stumbled over the same question and I've found a solution.

First make sure you upgrade to LESS 1.6 at least. You can use npm for that case.

Now you can use the following mixin:

.if (@condition, @property, @value) when (@condition = true){
     @{property}: @value;

Since LESS 1.6 you are able to pass PropertyNames to Mixins as well. So for example you could just use:

.myHeadline {
   .if(@include-lineHeight,  line-height, '35px');

If @include-lineheight resolves to true LESS will print the line-height: 35px and it will skip the mixin if @include-lineheight is not true.

How to hide TabPage from TabControl

I realize the question is old, and the accepted answer is old, but ...

At least in .NET 4.0 ...

To hide a tab:


To put it back:

tabControl.TabPages.Insert(index, tabPage);

TabPages works so much better than Controls for this.

How to save an image locally using Python whose URL address I already know?

Use a simple python wget module to download the link. Usage below:

import wget'')

Could not load file or assembly 'System.Net.Http.Formatting' or one of its dependencies. The system cannot find the path specified

VS2019: Tools -> Nuget Package Manager -> Package Manager Setting -> in Package Restore section, check 2 options. After that, go to project packages folder and delete all child folders inside (for no longer any error) Then Rebuild solution, Nuget will redownload all packages and project should run without any reference.

How to delete file from public folder in laravel 5.1

Two ways to delete the image from public folder without changing laravel filesystems config file or messing with pure php unlink function:

  1. Using the default local storage you need to specify public subfolder:
  1. Use public storage directly:

I would suggest second way as the best one.

Hope this help other people.

Disable browsers vertical and horizontal scrollbars

IE has some bug with the scrollbars. So if you want either of the two, you must include the following to hide the horizontal scrollbar:

overflow-x: hidden;

and to hide vertical:

overflow-y: hidden;
overflow-x: scroll;

How can I get the "network" time, (from the "Automatic" setting called "Use network-provided values"), NOT the time on the phone?

the time signal is not built into network antennas: you have to use the NTP protocol in order to retrieve the time on a ntp server. there are plenty of ntp clients, available as standalone executables or libraries.

the gps signal does indeed include a precise time signal, which is available with any "fix".

however, if nor the network, nor the gps are available, your only choice is to resort on the time of the phone... your best solution would be to use a system wide setting to synchronize automatically the phone time to the gps or ntp time, then always use the time of the phone.

note that the phone time, if synchronized regularly, should not differ much from the gps or ntp time. also note that forcing a user to synchronize its time may be intrusive, you 'd better ask your user if he accepts synchronizing. at last, are you sure you absolutely need a time that precise ?

What does the SQL Server Error "String Data, Right Truncation" mean and how do I fix it?

I was facing the same issue. So, i created a stored Procedure and defined the size like @FromDate datetime, @ToDate datetime, @BL varchar(50)

After defining the size in @BL varchar(50), i did not face any problem. Now it is working fine

Google maps responsive resize

Move your map variable into a scope where the event listener can use it. You are creating the map inside your initialize() function and nothing else can use it when created that way.

var map; //<-- This is now available to both event listeners and the initialize() function
function initialize() {
  var mapOptions = {
   center: new google.maps.LatLng(40.5472,12.282715),
   zoom: 6,
   mapTypeId: google.maps.MapTypeId.ROADMAP
  map = new google.maps.Map(document.getElementById("map-canvas"),
google.maps.event.addDomListener(window, 'load', initialize);
google.maps.event.addDomListener(window, "resize", function() {
 var center = map.getCenter();
 google.maps.event.trigger(map, "resize");

Found a swap file by the name

More info... Some times .swp files might be holded by vm that was running in backgroung. You may see permission denied message when try to delete the files.

Check and kill process vm

Convert timestamp to string

try this

SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
String string  = dateFormat.format(new Date());

you can create any format see this

Handling the TAB character in Java

Or you could just perform a trim() on the string to handle the case when people use spaces instead of tabs (unless you are reading makefiles)

jquery - Click event not working for dynamically created button

My guess is that the buttons you created are not yet on the page by the time you bind the button. Either bind each button in the $.getJSON function, or use a dynamic binding method like:

$('body').on('click', 'button', function() {

Note you probably don't want to do this on the 'body' tag, but instead wrap the buttons in another div or something and call on on it.

jQuery On Method

Call Jquery function

To call the function on click of some html element (control).


You will need to ensure you bind the event when your html element is ready on which you binding the event. You can put the code in document.ready


You can use anonymous function to bind the event to the html element.

            title:'My Title',  
            msg:'The message content',  

If you want to bind click with many elements you can use class selector


Edit based on comments by OP, If you want to call function under some condition

You can use if for conditional execution, for example,

if(a == 3)

JavaScript URL Decode function


you can get passed parameters by using this bit of code:

//parse URL to get values: var i = getUrlVars()["i"];
function getUrlVars() {
    var vars = [], hash;
    var hashes = window.location.href.slice(window.location.href.indexOf('?') + 1).split('&');
    for (var i = 0; i < hashes.length; i++) {
        hash = hashes[i].split('=');
        vars[hash[0]] = hash[1];
    return vars;

Or this one-liner to get the parameters:"your_parameter=")[1]

How do you print in a Go test using the "testing" package?

The *_test.go file is a Go source like the others, you can initialize a new logger every time if you need to dump complex data structure, here an example:

// initZapLog is delegated to initialize a new 'log manager'
func initZapLog() *zap.Logger {
    config := zap.NewDevelopmentConfig()
    config.EncoderConfig.EncodeLevel = zapcore.CapitalColorLevelEncoder
    config.EncoderConfig.TimeKey = "timestamp"
    config.EncoderConfig.EncodeTime = zapcore.ISO8601TimeEncoder
    logger, _ := config.Build()
    return logger

Then, every time, in every test:

func TestCreateDB(t *testing.T) {
    loggerMgr := initZapLog()
    // Make logger avaible everywhere
    defer loggerMgr.Sync() // flushes buffer, if any
    logger := loggerMgr.Sugar()
    conf := initConf()
    /* Your test here
    if false {

Iterating through a string word by word

Using nltk.

from nltk.tokenize import sent_tokenize, word_tokenize
sentences = sent_tokenize("This is a string.")
words_in_each_sentence = word_tokenize(sentences)

You may use TweetTokenizer for parsing casual text with emoticons and such.

How to find the size of a table in SQL?

Do you by size mean the number of records in the table, by any chance? In that case:

SELECT COUNT(*) FROM your_table_name

Swift - encode URL

Swift 3

In Swift 3 there is addingPercentEncoding

let originalString = "test/test"
let escapedString = originalString.addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)



Swift 1

In iOS 7 and above there is stringByAddingPercentEncodingWithAllowedCharacters

var originalString = "test/test"
var escapedString = originalString.stringByAddingPercentEncodingWithAllowedCharacters(.URLHostAllowedCharacterSet())
println("escapedString: \(escapedString)")



The following are useful (inverted) character sets:

URLFragmentAllowedCharacterSet  "#%<>[\]^`{|}
URLHostAllowedCharacterSet      "#%/<>?@\^`{|}
URLPasswordAllowedCharacterSet  "#%/:<>?@[\]^`{|}
URLPathAllowedCharacterSet      "#%;<>?[\]^`{|}
URLQueryAllowedCharacterSet     "#%<>[\]^`{|}
URLUserAllowedCharacterSet      "#%/:<>?@[\]^`

If you want a different set of characters to be escaped create a set:
Example with added "=" character:

var originalString = "test/test=42"
var customAllowedSet =  NSCharacterSet(charactersInString:"=\"#%/<>?@\\^`{|}").invertedSet
var escapedString = originalString.stringByAddingPercentEncodingWithAllowedCharacters(customAllowedSet)
println("escapedString: \(escapedString)")



Example to verify ascii characters not in the set:

func printCharactersInSet(set: NSCharacterSet) {
    var characters = ""
    let iSet = set.invertedSet
    for i: UInt32 in 32..<127 {
        let c = Character(UnicodeScalar(i))
        if iSet.longCharacterIsMember(i) {
            characters = characters + String(c)
    print("characters not in set: \'\(characters)\'")

Java - Abstract class to contain variables?

I would have thought that something like this would be much better, since you're adding a variable, so why not restrict access and make it cleaner? Your getter/setters should do what they say on the tin.

public abstract class ExternalScript extends Script {

    private String source;

    public void setSource(String file) {
        source = file;

    public String getSource() {
        return source;

Bringing this back to the question, do you ever bother looking at where the getter/setter code is when reading it? If they all do getting and setting then you don't need to worry about what the function 'does' when reading the code. There are a few other reasons to think about too:

  • If source was protected (so accessible by subclasses) then code gets messy: who's changing the variables? When it's an object it then becomes hard when you need to refactor, whereas a method tends to make this step easier.
  • If your getter/setter methods aren't getting and setting, then describe them as something else.

Always think whether your class is really a different thing or not, and that should help decide whether you need anything more.

How do I unload (reload) a Python module?

Another way could be to import the module in a function. This way when the function completes the module gets garbage collected.

HTML5 form validation pattern alphanumeric with spaces?

My solution is to cover all the range of diacritics:


A-z - this is for all latin characters

0-9 - this is for all digits

À-ž - this is for all diacritics

\s - this is for spaces

{2,} - string needs to be at least 2 characters long

Background thread with QThread in PyQt

Based on the Worker objects methods mentioned in other answers, I decided to see if I could expand on the solution to invoke more threads - in this case the optimal number the machine can run and spin up multiple workers with indeterminate completion times. To do this I still need to subclass QThread - but only to assign a thread number and to 'reimplement' the signals 'finished' and 'started' to include their thread number.

I've focused quite a bit on the signals between the main gui, the threads, and the workers.

Similarly, others answers have been a pains to point out not parenting the QThread but I don't think this is a real concern. However, my code also is careful to destroy the QThread objects.

However, I wasn't able to parent the worker objects so it seems desirable to send them the deleteLater() signal, either when the thread function is finished or the GUI is destroyed. I've had my own code hang for not doing this.

Another enhancement I felt was necessary was was reimplement the closeEvent of the GUI (QWidget) such that the threads would be instructed to quit and then the GUI would wait until all the threads were finished. When I played with some of the other answers to this question, I got QThread destroyed errors.

Perhaps it will be useful to others. I certainly found it a useful exercise. Perhaps others will know a better way for a thread to announce it identity.

#!/usr/bin/env python3
# Author:   --<>
# Purpose:  To demonstrate creation of multiple threads and identify the receipt of thread results
# Created: 19/12/15

import sys

from PyQt4.QtCore import QThread, pyqtSlot, pyqtSignal
from PyQt4.QtGui import QApplication, QLabel, QWidget, QGridLayout

import sys
import worker

class Thread(QThread):
    #make new signals to be able to return an id for the thread
    startedx = pyqtSignal(int)
    finishedx = pyqtSignal(int)

    def __init__(self,i,parent=None):
        self.idd = i


    def starttt(self):
        print('started signal from thread emitted')

    def finisheddd(self):
        print('finished signal from thread emitted')

class Form(QWidget):

    def __init__(self):



        #Establish the maximum number of threads the machine can optimally handle
        #Generally relates to the number of processors

        self.threadtest = QThread(self)
        self.idealthreadcount = self.threadtest.idealThreadCount()

        print("This machine can handle {} threads optimally".format(self.idealthreadcount))

        while i <self.idealthreadcount:

        while i<self.idealthreadcount:

        print("Main Gui running in thread {}.".format(self.thread()))

    def setupThread(self,i):

        self.worker[i]= worker.Worker(i)  # no parent!
        #print("Worker object runningt in thread {} prior to movetothread".format(self.worker[i].thread()) )
        self.threadx[i] = Thread(i,parent=self)  #  if parent isn't specified then need to be careful to destroy thread 
        self.threadx[i].setObjectName("python thread{}"+str(i))
        #print("Thread object runningt in thread {} prior to movetothread".format(self.threadx[i].thread()) )


        #The next line is optional, you may want to start the threads again without having to create all the code again.



        #This is the key code that actually get the worker code onto another processor or thread.

    def startThread(self,i):

    def threadStarted(self,i):
        print('Thread {}  started'.format(i))
        print("Thread priority is {}".format(self.threadx[i].priority()))        

    def threadFinished(self,i):
        print('Thread {} finished'.format(i))

    def threadTerminated(self,i):
        print("Thread {} terminated".format(i))

    def workerResultReady(self,j,i):
        print('Worker {} result returned'.format(i))
        if i ==0:
        if i ==1:
        if i ==2:
        if i ==3:

        #print('Thread {} has started'.format(self.threadx[i].currentThreadId()))    

    def workerFinished(self,i):
        print('Worker {} finished'.format(i))

    def initUI(self):
        self.label1 = QLabel("0")
        self.label2= QLabel("0")
        self.label3= QLabel("0")
        self.label4 = QLabel("0")
        grid = QGridLayout(self)
        grid.addWidget(self.label4,0,3) #Layout parents the self.labels

        self.move(300, 150)
        self.setWindowTitle('thread test')

    def closeEvent(self, event):

        #this tells the threads to stop running
        while i <self.idealthreadcount:

         #this ensures window cannot be closed until the threads have finished.
        while i <self.idealthreadcount:


if __name__=='__main__':
    app = QApplication(sys.argv)
    form = Form()

And the worker code below

#!/usr/bin/env python3
# Author:   --<>
# Purpose:  Stack Overflow
# Created: 19/12/15

import sys
import unittest

from PyQt4.QtCore import QThread, QObject, pyqtSignal, pyqtSlot
import time
import random

class Worker(QObject):
    finished = pyqtSignal(int)
    intReady = pyqtSignal(int,int)

    def __init__(self, i=0):
        '''__init__ is called while the worker is still in the Gui thread. Do not put slow or CPU intensive code in the __init__ method'''

        self.idd = i

    def procCounter(self): # This slot takes no params
        for j in range(1, 10):
            random_time = random.weibullvariate(1,2)
            print('Worker {0} in thread {1}'.format(self.idd, self.thread().idd))


if __name__=='__main__':

How do I specify "close existing connections" in sql script

Go to management studio and do everything you describe, only instead of clicking OK, click on Script. It will show the code it will run which you can then incorporate in your scripts.

In this case, you want:


I get "Http failure response for (unknown url): 0 Unknown Error" instead of actual error message in Angular

This error was occurring for me in Firefox but not Chrome while developing locally, and it turned out to be caused by Firefox not trusting my local API's ssl certificate (which is not valid, but I had added it to my local cert store, which let chrome trust it but not ff). Navigating to the API directly and adding an exception in Firefox fixed the issue.

Why check both isset() and !empty()

$a = 0;
if (isset($a)) { //$a is set because it has some value ,eg:0
    echo '$a has value';
if (!empty($a)) { //$a is empty because it has value 0
    echo '$a is not empty';
} else {
    echo '$a is empty';

How to post SOAP Request from PHP

PHP has SOAP support. Just call

$client = new SoapClient($url);

to connect to the SoapServer and then you can get list of functions and call functions simply by doing...


$result = $client->functionName();  

for more

WPF Check box: Check changed handling

I know this is an old question, but how about just binding to Command if using MVVM?


<CheckBox Content="Case Sensitive" Command="{Binding bSearchCaseSensitive}"/>

For me it triggers on both Check and Uncheck.

What does the M stand for in C# Decimal literal notation?

Well, i guess M represent the mantissa. Decimal can be used to save money, but it doesn't mean, decimal only used for money.

How can I parse a YAML file in Python

The easiest and purest method without relying on C headers is PyYaml (documentation), which can be installed via pip install pyyaml:

#!/usr/bin/env python

import yaml

with open("example.yaml", 'r') as stream:
    except yaml.YAMLError as exc:

And that's it. A plain yaml.load() function also exists, but yaml.safe_load() should always be preferred unless you explicitly need the arbitrary object serialization/deserialization provided in order to avoid introducing the possibility for arbitrary code execution.

Note the PyYaml project supports versions up through the YAML 1.1 specification. If YAML 1.2 specification support is needed, see ruamel.yaml as noted in this answer.

Convert 24 Hour time to 12 Hour plus AM/PM indication Oracle SQL

For the 24-hour time, you need to use HH24 instead of HH.

For the 12-hour time, the AM/PM indicator is written as A.M. (if you want periods in the result) or AM (if you don't). For example:

SELECT invoice_date,
       TO_CHAR(invoice_date, 'DD-MM-YYYY HH24:MI:SS') "Date 24Hr",
       TO_CHAR(invoice_date, 'DD-MM-YYYY HH:MI:SS AM') "Date 12Hr"
  FROM invoices

For more information on the format models you can use with TO_CHAR on a date, see

How can I remove an entry in global configuration with git config?

I'm not sure what you mean by "undo" the change. You can remove the core.excludesfile setting like this:

git config --global --unset core.excludesfile

And of course you can simply edit the config file:

git config --global --edit

...and then remove the setting by hand.

String index out of range: 4

You are using the wrong iteration counter, replace inp.charAt(i) with inp.charAt(j).

Force flex item to span full row width

When you want a flex item to occupy an entire row, set it to width: 100% or flex-basis: 100%, and enable wrap on the container.

The item now consumes all available space. Siblings are forced on to other rows.

.parent {
  display: flex;
  flex-wrap: wrap;

#range, #text {
  flex: 1;

.error {
  flex: 0 0 100%; /* flex-grow, flex-shrink, flex-basis */
  border: 1px dashed black;
<div class="parent">
  <input type="range" id="range">
  <input type="text" id="text">
  <label class="error">Error message (takes full width)</label>

More info: The initial value of the flex-wrap property is nowrap, which means that all items will line up in a row. MDN

What is the garbage collector in Java?

It frees memory allocated to objects that are not being used by the program any more - hence the name "garbage". For example:

public static Object otherMethod(Object obj) {
    return new Object();

public static void main(String[] args) {
    Object myObj = new Object();
    myObj = otherMethod(myObj);
    // ... more code ...  

I know this is extremely contrived, but here after you call otherMethod() the original Object created is made unreachable - and that's "garbage" that gets garbage collected.

In Java the GC runs automatically, but you can also call it explicitly with System.gc() and try to force a major garbage collection. As Pascal Thivent points out, you really shouldn't have to do this and it might do more harm than good (see this question).

For more, see the wikipedia entry on Garbage collection and Tuning Garbage Collection (from Oracle)

Open Windows Explorer and select a file

Check out this snippet:

Private Sub openDialog()
    Dim fd As Office.FileDialog

    Set fd = Application.FileDialog(msoFileDialogFilePicker)

   With fd

      .AllowMultiSelect = False

      ' Set the title of the dialog box.
      .Title = "Please select the file."

      ' Clear out the current filters, and add our own.
      .Filters.Add "Excel 2003", "*.xls"
      .Filters.Add "All Files", "*.*"

      ' Show the dialog box. If the .Show method returns True, the
      ' user picked at least one file. If the .Show method returns
      ' False, the user clicked Cancel.
      If .Show = True Then
        txtFileName = .SelectedItems(1) 'replace txtFileName with your textbox

      End If
   End With
End Sub

I think this is what you are asking for.

Finding rows containing a value (or values) in any column

If you want to find the rows that have any of the values in a vector, one option is to loop the vector (lapply(v1,..)), create a logical index of (TRUE/FALSE) with (==). Use Reduce and OR (|) to reduce the list to a single logical matrix by checking the corresponding elements. Sum the rows (rowSums), double negate (!!) to get the rows with any matches.

indx1 <- !!rowSums(Reduce(`|`, lapply(v1, `==`, df)), na.rm=TRUE)

Or vectorise and get the row indices with which with arr.ind=TRUE

indx2 <- unique(which(Vectorize(function(x) x %in% v1)(df),


I didn't use @kristang's solution as it is giving me errors. Based on a 1000x500 matrix, @konvas's solution is the most efficient (so far). But, this may vary if the number of rows are increased

val <- paste0('M0', 1:1000)
df1 <-, NA), 1000*500, 
  replace=TRUE), ncol=500), stringsAsFactors=FALSE) 
v1 <- sample(val, 200, replace=FALSE)

 konvas <- function() {apply(df1, 1, function(r) any(r %in% v1))}
 akrun1 <- function() {!!rowSums(Reduce(`|`, lapply(v1, `==`, df1)),
 akrun2 <- function() {unique(which(Vectorize(function(x) x %in% 

 microbenchmark(konvas(), akrun1(), akrun2(), unit='relative', times=20L)
 #Unit: relative
 #   expr       min         lq       mean     median         uq      max   neval
 # konvas()   1.00000   1.000000   1.000000   1.000000   1.000000  1.00000    20
 # akrun1() 160.08749 147.642721 125.085200 134.491722 151.454441 52.22737    20
 # akrun2()   5.85611   5.641451   4.676836   5.330067   5.269937  2.22255    20
 # cld
 #  a 
 #  b
 #  a 

For ncol = 10, the results are slighjtly different:

expr       min        lq     mean    median        uq       max    neval
 konvas()  3.116722  3.081584  2.90660  2.983618  2.998343  2.394908    20
 akrun1() 27.587827 26.554422 22.91664 23.628950 21.892466 18.305376    20
 akrun2()  1.000000  1.000000  1.00000  1.000000  1.000000  1.000000    20


 v1 <- c('M017', 'M018')
 df <- structure(list(datetime = c("04.10.2009 01:24:51",
"04.10.2009 01:24:53", 
"04.10.2009 01:24:54", "04.10.2009 01:25:06", "04.10.2009 01:25:07", 
"04.10.2009 01:26:07", "04.10.2009 01:26:27", "04.10.2009 01:27:23", 
"04.10.2009 01:27:30", "04.10.2009 01:27:32", "04.10.2009 01:27:34"
), col1 = c("M017", "M018", "M051", "<NA>", "<NA>", "<NA>", "<NA>", 
"<NA>", "<NA>", "M017", "M051"), col2 = c("<NA>", "<NA>", "<NA>", 
"M016", "M015", "M017", "M017", "M017", "M017", "<NA>", "<NA>"
), col3 = c("<NA>", "<NA>", "<NA>", "<NA>", "<NA>", "<NA>", "<NA>", 
"<NA>", "<NA>", "<NA>", "<NA>"), col4 = c(NA, NA, NA, NA, NA, 
NA, NA, NA, NA, NA, NA)), .Names = c("datetime", "col1", "col2", 
"col3", "col4"), class = "data.frame", row.names = c("1", "2", 
"3", "4", "5", "6", "7", "8", "9", "10", "11"))

global variable for all controller and views

There are two options:

  1. Create a php class file inside app/libraries/YourClassFile.php

    a. Any function you create in it would be easily accessible in all the views and controllers.

    b. If it is a static function you can easily access it by the class name.

    c. Make sure you inclued "app/libraries" in autoload classmap in composer file.

  2. In app/config/app.php create a variable and you can reference the same using


Hope this helps.

Edit 1:

Example for my 1st point:

// app/libraries/DefaultFunctions.php

class DefaultFunctions{

    public static function getSomeValue(){
     // Fetch the Site Settings object
     $site_settings = Setting::all();
     return $site_settings; 


"autoload": {
        "classmap": [
        "app/libraries" // add the libraries to access globaly.


   $default_functions  = new DefaultFunctions();

Anybody knows any knowledge base open source?

I have used phpMyFAQ and found it to be very good.

Display all views on oracle database

Open a new worksheet on the related instance (Alt-F10) and run the following query

SELECT view_name, owner
FROM sys.all_views 
ORDER BY owner, view_name

Why doesn't document.addEventListener('load', function) work in a greasemonkey script?

To get the value of my drop down box on page load, I use


Hope this helps some one.

java : non-static variable cannot be referenced from a static context Error

This is an interesting question, i just want to give another angle by adding a little more info.You can understand why an exception is thrown if you see how static methods operate. These methods can manipulate either static data, local data or data that is sent to it as a parameter.why? because static method can be accessed by any object, from anywhere. So, there can be security issues posed or there can be leaks of information if it can use instance variables.Hence the compiler has to throw such a case out of consideration.

How can I send mail from an iPhone application

Below code is used in my application to send email with an attachment here the attachments is an image .You can send any type of file only thing is to keep in mind is that you had to specify the correct 'mimeType'

add this to your .h file

#import <MessageUI/MFMailComposeViewController.h>

Add MessageUI.framework to your project file

NSArray *paths = SSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);

NSString *documentsDirectory = [paths objectAtIndex:0];

NSString *getImagePath = [documentsDirectory stringByAppendingPathComponent:@"myGreenCard.png"];

MFMailComposeViewController* controller = [[MFMailComposeViewController alloc] init];
controller.mailComposeDelegate = self;
[controller setSubject:@"Green card application"];
[controller setMessageBody:@"Hi , <br/>  This is my new latest designed green card." isHTML:YES]; 
[controller addAttachmentData:[NSData dataWithContentsOfFile:getImagePath] mimeType:@"png" fileName:@"My Green Card"];
if (controller)
    [self presentModalViewController:controller animated:YES];
[controller release];

Delegate method is as shown below

  -(void)mailComposeController:(MFMailComposeViewController*)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError*)error;
    if (result == MFMailComposeResultSent) {
        NSLog(@"It's away!");
    [self dismissModalViewControllerAnimated:YES];

Ruby 2.0.0p0 IRB warning: "DL is deprecated, please use Fiddle"

You may want to comment out the DL is deprecated, please use Fiddle warning at


since it’s annoying and you are not the irb/pry or some other gems code owner

PostgreSQL error 'Could not connect to server: No such file or directory'

I had that problem when I upgraded Postgres to 9.3.x. The quick fix for me was to downgrade to whichever 9.2.x version I had before (no need to install a new one).

$ ls /usr/local/Cellar/postgresql/
$ brew switch postgresql 9.2.4
$ launchctl unload ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist
$ launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist
<open a new Terminal tab or window to reload>
$ psql

"Homebrew install specific version of formula?" offers a much more comprehensive explanation along with alternative ways to fix the problem.

How to view an HTML file in the browser with Visual Studio Code

Ctrl + F1 will open the default browser. alternatively you can hit Ctrl + shift + P to open command window and select "View in Browser". The html code must be saved in a file (unsaved code on the editor - without extension, doesn't work)

Count number of rows per group and add result to original data frame

One simple line in base R:

df$count = table(interaction(df[, (c("name", "type"))]))[interaction(df[, (c("name", "type"))])]

Same in two lines, for clarity/efficiency:

fact = interaction(df[, (c("name", "type"))])
df$count = table(fact)[fact]

how do I get eclipse to use a different compiler version for Java?

Eclipse uses it's own internal compiler that can compile to several Java versions.

From Eclipse Help > Java development user guide > Concepts > Java Builder

The Java builder builds Java programs using its own compiler (the Eclipse Compiler for Java) that implements the Java Language Specification.

For Eclipse Mars.1 Release (4.5.1), this can target 1.3 to 1.8 inclusive.

When you configure a project:

[project-name] > Properties > Java Compiler > Compiler compliance level

This configures the Eclipse Java compiler to compile code to the specified Java version, typically 1.8 today.

Host environment variables, eg JAVA_HOME etc, are not used.

The Oracle/Sun JDK compiler is not used.

How to unsubscribe to a broadcast event in angularJS. How to remove function registered via $on

You need to store the returned function and call it to unsubscribe from the event.

var deregisterListener = $scope.$on("onViewUpdated", callMe);
deregisterListener (); // this will deregister that listener

This is found in the source code :) at least in 1.0.4. I'll just post the full code since it's short

  * @param {string} name Event name to listen on.
  * @param {function(event)} listener Function to call when the event is emitted.
  * @returns {function()} Returns a deregistration function for this listener.
$on: function(name, listener) {
    var namedListeners = this.$$listeners[name];
    if (!namedListeners) {
      this.$$listeners[name] = namedListeners = [];

    return function() {
      namedListeners[indexOf(namedListeners, listener)] = null;

Also, see the docs.

stdcall and cdecl

Raymond Chen gives a nice overview of what __stdcall and __cdecl does.

(1) The caller "knows" to clean up the stack after calling a function because the compiler knows the calling convention of that function and generates the necessary code.

void __stdcall StdcallFunc() {}

void __cdecl CdeclFunc()
    // The compiler knows that StdcallFunc() uses the __stdcall
    // convention at this point, so it generates the proper binary
    // for stack cleanup.

It is possible to mismatch the calling convention, like this:

LRESULT MyWndProc(HWND hwnd, UINT msg,
    WPARAM wParam, LPARAM lParam);
// ...
// Compiler usually complains but there's this cast here...
windowClass.lpfnWndProc = reinterpret_cast<WNDPROC>(&MyWndProc);

So many code samples get this wrong it's not even funny. It's supposed to be like this:

// CALLBACK is #define'd as __stdcall
    WPARAM wParam, LPARAM lParam);
// ...
windowClass.lpfnWndProc = &MyWndProc;

However, assuming the programmer doesn't ignore compiler errors, the compiler will generate the code needed to clean up the stack properly since it'll know the calling conventions of the functions involved.

(2) Both ways should work. In fact, this happens quite frequently at least in code that interacts with the Windows API, because __cdecl is the default for C and C++ programs according to the Visual C++ compiler and the WinAPI functions use the __stdcall convention.

(3) There should be no real performance difference between the two.

Encode String to UTF-8

A Java String is internally always encoded in UTF-16 - but you really should think about it like this: an encoding is a way to translate between Strings and bytes.

So if you have an encoding problem, by the time you have String, it's too late to fix. You need to fix the place where you create that String from a file, DB or network connection.

MISCONF Redis is configured to save RDB snapshots

Had encountered this error and was able to figure out from log that the error is because of the disk space not being enough. All the data that was inserted in my case was not needed any longer. So I tried to FLUSHALL. Since redis-rdb-bgsave process was running, it was not allowing to FLUSH the data also. I followed below steps and was able to continue.

  1. Login to redis client
  2. Execute config set stop-writes-on-bgsave-error no
  3. Execute FLUSHALL (Data stored was not needed)
  4. Execute config set stop-writes-on-bgsave-error yes

The process redis-rdb-bgsave was no longer running after the above steps.

Hidden TextArea

Set CSS display to none for textarea

<textarea name="hide" style="display:none;"></textarea>

angular.js ng-repeat li items with html content

You can use NGBindHTML or NGbindHtmlUnsafe this will not escape the html content of your model.

<div ng-app ng-controller="MyCtrl">
    <li ng-repeat=" opt in opts"  ng-bind-html-unsafe="opt.text">
        {{ opt.text }}


This works, anyway you should be very careful when using unsanitized html content, you should really trust the source of the content.

Create a .csv file with values from a Python list

Here is another solution that does not require the csv module.

print ', '.join(['"'+i+'"' for i in myList])

Example :

>>> myList = [u'value 1', u'value 2', u'value 3']
>>> print ', '.join(['"'+i+'"' for i in myList])
"value 1", "value 2", "value 3"

However, if the initial list contains some ", they will not be escaped. If it is required, it is possible to call a function to escape it like that :

print ', '.join(['"'+myFunction(i)+'"' for i in myList])

proper way to logout from a session in PHP

// Initialize the session.
// Unset all of the session variables.
// Finally, destroy the session.    

// Include URL for Login page to login again.
header("Location: login.php");

Format number as percent in MS SQL Server

And for all SQL Server versions

SELECT CAST(0.973684210526315789 * 100 AS DECIMAL(18, 2))

ToString() function in Go

I prefer something like the following:

type StringRef []byte

func (s StringRef) String() string {
        return string(s[:])


// rather silly example, but ...

ssh_exchange_identification: Connection closed by remote host under Git bash

I solved it this way.

ssh -vvv <username> to see github IP.

Then opened browser and opened github via IP to find it was an issue with firewall.

inline if statement java, why is not working

Syntax is Shown below:

"your condition"? "step if true":"step if condition fails"

.NET 4.0 has a new GAC, why?

Yes since there are 2 distinct Global Assembly Cache (GAC), you will have to manage each of them individually.

In .NET Framework 4.0, the GAC went through a few changes. The GAC was split into two, one for each CLR.

The CLR version used for both .NET Framework 2.0 and .NET Framework 3.5 is CLR 2.0. There was no need in the previous two framework releases to split GAC. The problem of breaking older applications in Net Framework 4.0.

To avoid issues between CLR 2.0 and CLR 4.0 , the GAC is now split into private GAC’s for each runtime.The main change is that CLR v2.0 applications now cannot see CLR v4.0 assemblies in the GAC.



It seems to be because there was a CLR change in .NET 4.0 but not in 2.0 to 3.5. The same thing happened with 1.1 to 2.0 CLR. It seems that the GAC has the ability to store different versions of assemblies as long as they are from the same CLR. They do not want to break old applications.

See the following information in MSDN about the GAC changes in 4.0.

For example, if both .NET 1.1 and .NET 2.0 shared the same GAC, then a .NET 1.1 application, loading an assembly from this shared GAC, could get .NET 2.0 assemblies, thereby breaking the .NET 1.1 application

The CLR version used for both .NET Framework 2.0 and .NET Framework 3.5 is CLR 2.0. As a result of this, there was no need in the previous two framework releases to split the GAC. The problem of breaking older (in this case, .NET 2.0) applications resurfaces in Net Framework 4.0 at which point CLR 4.0 released. Hence, to avoid interference issues between CLR 2.0 and CLR 4.0, the GAC is now split into private GACs for each runtime.

As the CLR is updated in future versions you can expect the same thing. If only the language changes then you can use the same GAC.

Convert from MySQL datetime to another format with PHP

If you are using PHP 5, you can also try

$oDate = new DateTime($row->createdate);
$sDate = $oDate->format("Y-m-d H:i:s");

Check if input is number or letter javascript

Use Regular Expression to match for only letters. It's also good to have knowledge about, if you ever need to do something more complicated, like make sure it's a certain count of numbers.

function checkInp()
    var x=document.forms["myForm"]["age"].value;
    var regex=/^[a-zA-Z]+$/;
    if (!x.match(regex))
        alert("Must input string");
        return false;

Even better would be to deny anything but numbers:

function checkInp()
    var x=document.forms["myForm"]["age"].value;
    var regex=/^[0-9]+$/;
    if (x.match(regex))
        alert("Must input numbers");
        return false;

Evaluate list.contains string in JSTL

If you are using EL 3.0+, the best approach in this case is as this other answer explained in another topic:

For a Collection it's easy, just use the Colleciton#contains() method in EL.

<h:panelGroup id="p1" rendered="#{bean.panels.contains('p1')}">...</h:panelGroup>
<h:panelGroup id="p2" rendered="#{bean.panels.contains('p2')}">...</h:panelGroup>
<h:panelGroup id="p3" rendered="#{bean.panels.contains('p3')}">...</h:panelGroup>

For an Object[] (array), you'd need a minimum of EL 3.0 and utilize its new Lambda support.

<h:panelGroup id="p1" rendered="#{ -> v == 'p1').get()}">...</h:panelGroup>
<h:panelGroup id="p2" rendered="#{ -> v == 'p2').get()}">...</h:panelGroup>
<h:panelGroup id="p3" rendered="#{ -> v == 'p3').get()}">...</h:panelGroup>

If you're not on EL 3.0 yet, you'd need to create a custom EL function. [...]

Remove all occurrences of a value from a list?

you can do this

while 2 in x:   

better solution with list comprehension

x = [ i for i in x if i!=2 ]

Laravel Blade html image

Change /img/stuvi-logo.png to img/stuvi-logo.png

{{ HTML::image('img/stuvi-logo.png', 'alt text', array('class' => 'css-class')) }}

Which produces the following HTML.

<img src="http://your.url/img/stuvi-logo.png" class="css-class" alt="alt text">

How to pass multiple values through command argument in

You can try this:

CommandArgument='<%# "scrapid=" + Eval("ScrapId")+"&"+"UserId="+ Eval("UserId")%>'

Git push failed, "Non-fast forward updates were rejected"

You can add --force-with-lease to the command, it will works.

git push --force-with-lease

--force is destructive because it unconditionally overwrites the remote repository with whatever you have locally. But --force-with-lease ensure you don't overwrite other's work.

See more info here.

How do I compile jrxml to get jasper?

For anyone coming across this question who uses Jaspersoft Studio (which, I think, is replacing iReports; it's quite similar, still freeware, just based on eclipse), look for the "Compile Report" icon on top of the editor area of your .jrxml file. Its icon, first in that line of icons, is a file with binary numbers on it (at least in version 5.6.2):

Jaspersoft Studio - compile report

Clicking this icon will generate the .jasper file in the same directory as the .jrxml file.

Combining multiple condition in single case statement in Sql Server

select ROUND(CASE 

WHEN  CONVERT( float, REPLACE( isnull( value1,''),',',''))='' AND CONVERT( float, REPLACE( isnull( value2,''),',',''))='' then  CONVERT( float, REPLACE( isnull( value3,''),',',''))

WHEN  CONVERT( float, REPLACE( isnull( value1,''),',',''))='' AND CONVERT( float, REPLACE( isnull( value2,''),',',''))!='' then  CONVERT( float, REPLACE( isnull( value3,''),',',''))

WHEN  CONVERT( float, REPLACE( isnull( value1,''),',',''))!='' AND CONVERT( float, REPLACE( isnull( value2,''),',',''))='' then  CONVERT( float, REPLACE( isnull( value3,''),',',''))

else CONVERT( float, REPLACE(isnull( value1,''),',','')) end,0)  from Tablename where    ID="123" 

Python: can't assign to literal

1 is a literal. name = value is an assignment. 1 = value is an assignment to a literal, which makes no sense. Why would you want 1 to mean something other than 1?

Find most frequent value in SQL column

One way I like to use is:

select ,COUNT()as VAR1 from Table_Name

group by

order by VAR1 desc

limit 1

Returning a pointer to a vector element in c++

It is not a good idea to return iterators. Iterators become invalid when modifications to the vector (inversion\deletion ) happens. Also, the iterator is a local object created on stack and hence returning the address of the same is not at all safe. I'd suggest you to work with myObject rather than vector iterators.

EDIT: If the object is lightweight then its better you return the object itself. Otheriwise return pointers to myObject stored in the vector.

Read and write a String from text file

You may find this tool useful to not only read from file in Swift but also parse your input:

Just specify the file path and data delimiters like this:

import StreamScanner

if let input = NSFileHandle(forReadingAtPath: "/file/path")
    let scanner = StreamScanner(source: input, delimiters: NSCharacterSet(charactersInString: ":\n"))  //separate data by colons and newlines

    while let field: String =
        //use field

Hope, this helps.

How to find the highest value of a column in a data frame in R?

Try this solution:

Oz<-subset(data, data$Month==5,select=Ozone) # select ozone  value in the month of                 
                                             #May (i.e. Month = 5)
summary(T)                                   #gives caracteristics of table( contains 1 column of Ozone) including max, min ...

Provide password to ssh command inside bash script, Without the usage of public keys and Expect

Install sshpass, then launch the command:

sshpass -p "yourpassword" ssh -o StrictHostKeyChecking=no yourusername@hostname

jQuery UI dialog box not positioned center screen

Just solved the same problem, the issue was that i did not imported some js files, like widget.js :)

How can I remove an element from a list?

You can use which.

#[1] 1 2 3 4 5
#[1] 1 2 3 5

How to copy file from host to container using Dockerfile

Use COPY command like this:

COPY foo.txt /data/foo.txt
# where foo.txt is the relative path on host
# and /data/foo.txt is the absolute path in the image

read more details for COPY in the official documentation

An alternative would be to use ADD but this is not the best practise if you dont want to use some advanced features of ADD like decompression of tar.gz files.If you still want to use ADD command, do it like this:

ADD abc.txt /data/abc.txt
# where abc.txt is the relative path on host
# and /data/abc.txt is the absolute path in the image

read more details for ADD in the official documentation


Well I fond this post because I got a similar error. So I added the top line like in your controller respond_to :html, :json

then I got a different error(see below)

The controller-level respond_to' feature has been extracted to theresponders` gem. Add it to your Gemfile to continue using this feature: gem 'responders', '~> 2.0' Consult the Rails upgrade guide for details. But that had nothing to do with it.

HTML5 Email Validation

Using [a-zA-Z0-9.-_]{1,}@[a-zA-Z.-]{2,}[.]{1}[a-zA-Z]{2,} for [email protected] / [email protected]

How to mention C:\Program Files in batchfile

use this as somethink

"C:/Program Files (x86)/Nox/bin/nox_adb" install -r app.apk


"path_to_executable" commands_argument

Best way to extract a subvector from a vector?

vector<T>::const_iterator first = myVec.begin() + 100000;
vector<T>::const_iterator last = myVec.begin() + 101000;
vector<T> newVec(first, last);

It's an O(N) operation to construct the new vector, but there isn't really a better way.

Showing alert in angularjs when user leaves a page

$scope.rtGo = function(){

$scope.init = function () {

Reload page: using init

How do I make Visual Studio pause after executing a console application in debug mode?

You say you don't want to use the system("pause") hack. Why not?

If it's because you don't want the program to prompt when it's not being debugged, there's a way around that. This works for me:

void pause () {
    system ("pause");

int main (int argc, char ** argv) {
    // If "launched", then don't let the console close at the end until
    // the user has seen the report.
    // (See the MSDN ConGUI sample code)
    do {
        HANDLE hConsoleOutput = ::GetStdHandle (STD_OUTPUT_HANDLE);
        if (INVALID_HANDLE_VALUE == hConsoleOutput)
        if (0 == ::GetConsoleScreenBufferInfo (hConsoleOutput, &csbi))
        if (0 != csbi.dwCursorPosition.X)
        if (0 != csbi.dwCursorPosition.Y)
        if (csbi.dwSize.X <= 0)
        if (csbi.dwSize.Y <= 0)
        atexit (pause);
    } while (0);

I just paste this code into each new console application I'm writing. If the program is being run from a command window, the cursor position won't be <0,0>, and it won't call atexit(). If it has been launched from you debugger (any debugger) the console cursor position will be <0,0> and the atexit() call will be executed.

I got the idea from a sample program that used to be in the MSDN library, but I think it's been deleted.

NOTE: The Microsoft Visual Studio implementation of the system() routine requires the COMSPEC environment variable to identify the command line interpreter. If this environment variable gets messed up -- for example, if you've got a problem in the Visual Studio project's debugging properties so that the environment variables aren't properly passed down when the program is launched -- then it will just fail silently.

How to get a right click mouse event? Changing EventArgs to MouseEventArgs causes an error in Form1Designer?

See the code below, this is the complete code about getting a mouse event(rightclick, leftclick) And you can DIY this code and make it on your own.

using System; 
using System.Drawing; 
using System.Windows.Forms; 
using System.Runtime.InteropServices; 

namespace Demo_mousehook_csdn
    public partial class Form1 : Form
        public Form1()

        MouseHook mh;

        private void Form1_Load(object sender, EventArgs e)
            mh = new MouseHook();
            mh.MouseMoveEvent += mh_MouseMoveEvent;
            mh.MouseClickEvent += mh_MouseClickEvent;
            mh.MouseDownEvent += mh_MouseDownEvent;
            mh.MouseUpEvent += mh_MouseUpEvent;
        private void mh_MouseDownEvent(object sender, MouseEventArgs e)
            if (e.Button == MouseButtons.Left)
                richTextBox1.AppendText("Left Button Press\n");
            if (e.Button == MouseButtons.Right)
                richTextBox1.AppendText("Right Button Press\n");

        private void mh_MouseUpEvent(object sender, MouseEventArgs e)

            if (e.Button == MouseButtons.Left)
                richTextBox1.AppendText("Left Button Release\n");
            if (e.Button == MouseButtons.Right)
                richTextBox1.AppendText("Right Button Release\n");

        private void mh_MouseClickEvent(object sender, MouseEventArgs e)
            //MessageBox.Show(e.X + "-" + e.Y);
            if (e.Button == MouseButtons.Left)
                string sText = "(" + e.X.ToString() + "," + e.Y.ToString() + ")";
                label1.Text = sText;

        private void mh_MouseMoveEvent(object sender, MouseEventArgs e)
            int x = e.Location.X;
            int y = e.Location.Y;
            textBox1.Text = x + "";
            textBox2.Text = y + "";
        private void Form1_FormClosed(object sender, FormClosedEventArgs e)

        private void Form1_FormClosed_1(object sender, FormClosedEventArgs e)

        private void richTextBox1_TextChanged(object sender, EventArgs e)


    public class Win32Api
        public class POINT
            public int x;
            public int y;
        public class MouseHookStruct
            public POINT pt;
            public int hwnd;
            public int wHitTestCode;
            public int dwExtraInfo;
        public delegate int HookProc(int nCode, IntPtr wParam, IntPtr lParam);
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern bool UnhookWindowsHookEx(int idHook);
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern int CallNextHookEx(int idHook, int nCode, IntPtr wParam, IntPtr lParam);

    public class MouseHook
        private Point point;
        private Point Point
            get { return point; }
                if (point != value)
                    point = value;
                    if (MouseMoveEvent != null)
                        var e = new MouseEventArgs(MouseButtons.None, 0, point.X, point.Y, 0);
                        MouseMoveEvent(this, e);
        private int hHook;
        private const int WM_MOUSEMOVE = 0x200;
        private const int WM_LBUTTONDOWN = 0x201;
        private const int WM_RBUTTONDOWN = 0x204;
        private const int WM_MBUTTONDOWN = 0x207;
        private const int WM_LBUTTONUP = 0x202;
        private const int WM_RBUTTONUP = 0x205;
        private const int WM_MBUTTONUP = 0x208;
        private const int WM_LBUTTONDBLCLK = 0x203;
        private const int WM_RBUTTONDBLCLK = 0x206;
        private const int WM_MBUTTONDBLCLK = 0x209;
        public const int WH_MOUSE_LL = 14;
        public Win32Api.HookProc hProc;
        public MouseHook()
            this.Point = new Point();
        public int SetHook()
            hProc = new Win32Api.HookProc(MouseHookProc);
            hHook = Win32Api.SetWindowsHookEx(WH_MOUSE_LL, hProc, IntPtr.Zero, 0);
            return hHook;
        public void UnHook()
        private int MouseHookProc(int nCode, IntPtr wParam, IntPtr lParam)
            Win32Api.MouseHookStruct MyMouseHookStruct = (Win32Api.MouseHookStruct)Marshal.PtrToStructure(lParam, typeof(Win32Api.MouseHookStruct));
            if (nCode < 0)
                return Win32Api.CallNextHookEx(hHook, nCode, wParam, lParam);
                if (MouseClickEvent != null)
                    MouseButtons button = MouseButtons.None;
                    int clickCount = 0;
                    switch ((Int32)wParam)
                        case WM_LBUTTONDOWN:
                            button = MouseButtons.Left;
                            clickCount = 1;
                            MouseDownEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
                        case WM_RBUTTONDOWN:
                            button = MouseButtons.Right;
                            clickCount = 1;
                            MouseDownEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
                        case WM_MBUTTONDOWN:
                            button = MouseButtons.Middle;
                            clickCount = 1;
                            MouseDownEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
                        case WM_LBUTTONUP:
                            button = MouseButtons.Left;
                            clickCount = 1;
                            MouseUpEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
                        case WM_RBUTTONUP:
                            button = MouseButtons.Right;
                            clickCount = 1;
                            MouseUpEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
                        case WM_MBUTTONUP:
                            button = MouseButtons.Middle;
                            clickCount = 1;
                            MouseUpEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));

                    var e = new MouseEventArgs(button, clickCount, point.X, point.Y, 0);
                    MouseClickEvent(this, e);
                this.Point = new Point(,;
                return Win32Api.CallNextHookEx(hHook, nCode, wParam, lParam);

        public delegate void MouseMoveHandler(object sender, MouseEventArgs e);
        public event MouseMoveHandler MouseMoveEvent;

        public delegate void MouseClickHandler(object sender, MouseEventArgs e);
        public event MouseClickHandler MouseClickEvent;

        public delegate void MouseDownHandler(object sender, MouseEventArgs e);
        public event MouseDownHandler MouseDownEvent;

        public delegate void MouseUpHandler(object sender, MouseEventArgs e);
        public event MouseUpHandler MouseUpEvent;


You can download the demo And the tutorial here : C# Mouse Hook Demo

Adb Devices can't find my phone

I have a Samsung Galaxy and I had the same issue as you. Here's how to fix it:

In device manager on your Windows PC, even though it might say the USB drivers are installed correctly, there may exist corruption.

I went into device manager and uninstalled SAMSUNG Android USB Composite Device and made sure to check the box 'delete driver software'. Now the device will have an exclamation mark etc. I right clicked and installed the driver again (refresh copy). This finally made adb acknowledge my phone as an emulator.

As others noted, for Nexus 4, you can also try this fix.

Serialize object to query string in JavaScript/jQuery

Another option might be node-querystring.

It's available in both npm and bower, which is why I have been using it.

Inverse of a matrix using numpy

Inverse of a matrix using python and numpy:

>>> import numpy as np
>>> b = np.array([[2,3],[4,5]])
>>> np.linalg.inv(b)
array([[-2.5,  1.5],
       [ 2. , -1. ]])

Not all matrices can be inverted. For example singular matrices are not Invertable:

>>> import numpy as np
>>> b = np.array([[2,3],[4,6]])
>>> np.linalg.inv(b)

LinAlgError: Singular matrix

Solution to singular matrix problem:

try-catch the Singular Matrix exception and keep going until you find a transform that meets your prior criteria AND is also invertable.

Intuition for why matrix inversion can't always be done; like in singular matrices:

Imagine an old overhead film projector that shines a bright light through film onto a white wall. The pixels in the film are projected to the pixels on the wall.

If I stop the film projection on a single frame, you will see the pixels of the film on the wall and I ask you to regenerate the film based on what you see. That's easy, you say, just take the inverse of the matrix that performed the projection. An Inverse of a matrix is the reversal of the projection.

Now imagine if the projector was corrupted, and I put a distorted lens in front of the film. Now multiple pixels are projected to the same spot on the wall. I asked you again to "undo this operation with the matrix inverse". You say: "I can't because you destroyed information with the lens distortion, I can't get back to where we were, because the matrix is either Singular or Degenerate."

A matrix that can be used to transform some data into other data is invertable only if the process can be reversed with no loss of information. If your matrix can't be inverted, perhaps you are defining your projection using a guess-and-check methodology rather than using a process that guarantees a non-corrupting transform.

If you're using a heuristic or anything less than perfect mathematical precision, then you'll have to define another process to manage and quarantine distortions so that programming by Brownian motion can resume.


How to select distinct rows in a datatable and store into an array

Following works. I have it working for me with .NET 3.5 SP1

// Create the list of columns
String[] szColumns = new String[data.Columns.Count];
for (int index = 0; index < data.Columns.Count; index++)
    szColumns[index] = data.Columns[index].ColumnName;

// Get the distinct records
data = data.DefaultView.ToTable(true, szColumns);

Copy a file from one folder to another using vbscripting

Here's an answer, based on (and I think an improvement on) Tester101's answer, expressed as a subroutine, with the CopyFile line once instead of three times, and prepared to handle changing the file name as the copy is made (no hard-coded destination directory). I also found I had to delete the target file before copying to get this to work, but that might be a Windows 7 thing. The WScript.Echo statements are because I didn't have a debugger and can of course be removed if desired.

Sub CopyFile(SourceFile, DestinationFile)

    Set fso = CreateObject("Scripting.FileSystemObject")

    'Check to see if the file already exists in the destination folder
    Dim wasReadOnly
    wasReadOnly = False
    If fso.FileExists(DestinationFile) Then
        'Check to see if the file is read-only
        If fso.GetFile(DestinationFile).Attributes And 1 Then 
            'The file exists and is read-only.
            WScript.Echo "Removing the read-only attribute"
            'Remove the read-only attribute
            fso.GetFile(DestinationFile).Attributes = fso.GetFile(DestinationFile).Attributes - 1
            wasReadOnly = True
        End If

        WScript.Echo "Deleting the file"
        fso.DeleteFile DestinationFile, True
    End If

    'Copy the file
    WScript.Echo "Copying " & SourceFile & " to " & DestinationFile
    fso.CopyFile SourceFile, DestinationFile, True

    If wasReadOnly Then
        'Reapply the read-only attribute
        fso.GetFile(DestinationFile).Attributes = fso.GetFile(DestinationFile).Attributes + 1
    End If

    Set fso = Nothing

End Sub

java collections - keyset() vs entrySet() in map

Every call to the moves the iterator to the next element. If you want to use the current element in more than one statement or expression, you have to store it in a local variable. Or even better, why don't you simply use a for-each loop?

for (String key : map.keySet()) {
    System.out.println(key + ":" + map.get(key));

Moreover, loop over the entrySet is faster, because you don't query the map twice for each key. Also Map.Entry implementations usually implement the toString() method, so you don't have to print the key-value pair manually.

for (Entry<String, Integer> entry : map.entrySet()) {

Can two or more people edit an Excel document at the same time?

The new version of SharePoint and Office (SharePoint 2010 and Office 2010) respectively are supposed to allow for this. This also includes the web based versions. I have seen Word and Excel in action do this, not sure about other client applications.

I am not sure about the specific implementation features you are asking about in terms of security though. Sorry.,=

Here is a discussion

File upload from <input type="file">

I think that it's not supported. If you have a look at this DefaultValueAccessor directive (see You will see that the value used to update the bound element is $

This doesn't apply in the case of inputs with type file since the file object can be reached $event.srcElement.files instead.

For more details, you can have a look at this plunkr:

  selector: 'my-app',
  template: `
      <input type="file" (change)="onChange($event)"/>
  providers: [ UploadService ]
export class AppComponent {
  onChange(event) {
    var files = event.srcElement.files;

How to get element by innerText

To get the filter method from user1106925 working in <=IE11 if needed

You can replace the spread operator with:


and the includes call with a.textContent.match("your search term")

which works pretty neatly:

   .filter(a => a.textContent.match("your search term"))
   .forEach(a => console.log(a.textContent))

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

This worked for me on Ubuntu:

Stop MySQL server:

/etc/init.d/mysql stop

Start MySQL from the commandline:


In another terminal enter mysql and issue:

grant all privileges on *.* to 'root'@'%' with grant option;

You may also want to add

grant all privileges on *.* to 'root'@'localhost' with grant option;

and optionally use a password as well.

flush privileges;

and then exit your MySQL prompt and then kill the mysqld server running in the foreground. Restart with

/etc/init.d/mysql start  

Passing parameters to a Bash function

Knowledge of high level programming languages (C/C++, Java, PHP, Python, Perl, etc.) would suggest to the layman that Bourne Again Shell (Bash) functions should work like they do in those other languages.

Instead, Bash functions work like shell commands and expect arguments to be passed to them in the same way one might pass an option to a shell command (e.g. ls -l). In effect, function arguments in Bash are treated as positional parameters ($1, $2..$9, ${10}, ${11}, and so on). This is no surprise considering how getopts works. Do not use parentheses to call a function in Bash.

(Note: I happen to be working on OpenSolaris at the moment.)

# Bash style declaration for all you PHP/JavaScript junkies. :-)
# $1 is the directory to archive
# $2 is the name of the tar and zipped file when all is done.
function backupWebRoot ()
    tar -cvf - "$1" | zip -n .jpg:.gif:.png "$2" - 2>> $errorlog &&
        echo -e "\nTarball created!\n"

# sh style declaration for the purist in you. ;-)
# $1 is the directory to archive
# $2 is the name of the tar and zipped file when all is done.
backupWebRoot ()
    tar -cvf - "$1" | zip -n .jpg:.gif:.png "$2" - 2>> $errorlog &&
        echo -e "\nTarball created!\n"

# In the actual shell script
# $0               $1            $2

backupWebRoot ~/public/www/

Want to use names for variables? Just do something this.

local filename=$1 # The keyword declare can be used, but local is semantically more specific.

Be careful, though. If an argument to a function has a space in it, you may want to do this instead! Otherwise, $1 might not be what you think it is.

local filename="$1" # Just to be on the safe side. Although, if $1 was an integer, then what? Is that even possible? Humm.

Want to pass an array to a function?

callingSomeFunction "${someArray[@]}" # Expands to all array elements.

Inside the function, handle the arguments like this.

function callingSomeFunction ()
    for value in "$@" # You want to use "$@" here, not "$*" !!!!!

Need to pass a value and an array, but still use "$@" inside the function?

function linearSearch ()
    local myVar="$1"

    shift 1 # Removes $1 from the parameter list

    for value in "$@" # Represents the remaining parameters.
        if [[ $value == $myVar ]]
            echo -e "Found it!\t... after a while."
            return 0

    return 1

linearSearch $someStringValue "${someArray[@]}"

What can I use for good quality code coverage for C#/.NET?

An alternative to NCover can be PartCover, is an open source code coverage tool for .NET very similar to NCover, it includes a console application, a GUI coverage browser, and XSL transforms for use in CruiseControl.NET.

It is a very interesting product.

OpenCover has replaced PartCover.

How to import set of icons into Android Studio project

Newer versions of Android support vector graphics, which is preferred over PNG icons. Android Studio 2.1.2 (and probably earlier versions) comes with Vector Asset Studio, which will automatically create PNG files for vector graphics that you add.

The Vector Asset Studio supports importing vector icons from the SDK, as well as your own SVG files.

This article describes Vector Asset Studio:

Summary for how to add a vector graphic with PNG files (partially copied from that URL):

  1. In the Project window, select the Android view.
  2. Right-click the res folder and select New > Vector Asset.
  3. The Material Icon radio button should be selected; then click Choose
  4. Select your icon, tweak any settings you need to tweak, and Finish.
  5. Depending on your settings (see article), PNGs are generated during build at the app/build/generated/res/pngs/debug/ folder.

How to declare a global variable in React?

Maybe it's using a sledge-hammer to crack a nut, but using environment variables (with Dotenv you can also provide values throughout your React app. And that without any overhead code where they are used.

I came here because I found that some of the variables defined in my env files where static throughout the different envs, so I searched for a way to move them out of the env files. But honestly I don't like any of the alternatives I found here. I don't want to set up and use a context everytime I need those values.

I am not experienced when it comes to environments, so please, if there is a downside to this approach, let me know.

How to get the current time in milliseconds from C in Linux?

Use gettimeofday() to get the time in seconds and microseconds. Combining and rounding to milliseconds is left as an exercise.

How to split the filename from a full path in batch?

Parse a filename from the fully qualified path name (e.g., c:\temp\my.bat) to any component (e.g., File.ext).

Single line of code:

For %%A in ("C:\Folder1\Folder2\File.ext") do (echo %%~fA)

You can change out "C:\Folder1\Folder2\File.ext" for any full path and change "%%~fA" for any of the other options you will find by running "for /?" at the command prompt.

Elaborated Code

set "filename=C:\Folder1\Folder2\File.ext"
For %%A in ("%filename%") do (
    echo full path: %%~fA
    echo drive: %%~dA
    echo path: %%~pA
    echo file name only: %%~nA
    echo extension only: %%~xA
    echo expanded path with short names: %%~sA
    echo attributes: %%~aA
    echo date and time: %%~tA
    echo size: %%~zA
    echo drive + path: %%~dpA
    echo name.ext: %%~nxA
    echo full path + short name: %%~fsA)

Standalone Batch Script
Save as C:\cmd\ParseFn.cmd.

Add C:\cmd to your PATH environment variable and use it to store all of you reusable batch scripts.

@echo off
@echo ::___________________________________________________________________::
@echo ::                                                                   ::
@echo ::                              ParseFn                              ::
@echo ::                                                                   ::
@echo ::                           Chris Advena                            ::
@echo ::___________________________________________________________________::

:: Process arguements
if "%~1%"=="/?" goto help
if "%~1%"=="" goto help
if "%~2%"=="/?" goto help
if "%~2%"=="" (
    echo !!! Error: ParseFn requires two inputs. !!!
    goto help)

set in=%~1%
set out=%~2%
:: echo "%in:~3,1%"   "%in:~0,1%"
if "%in:~3,1%"=="" (
    if "%in:~0,1%"=="/" (
    set in=%~2%
    set out=%~1%)

:: Parse filename
set "ret="
For %%A in ("%in%") do (
    if "%out%"=="/f" (set ret=%%~fA)
    if "%out%"=="/d" (set ret=%%~dA)
    if "%out%"=="/p" (set ret=%%~pA)
    if "%out%"=="/n" (set ret=%%~nA)
    if "%out%"=="/x" (set ret=%%~xA)
    if "%out%"=="/s" (set ret=%%~sA)
    if "%out%"=="/a" (set ret=%%~aA)
    if "%out%"=="/t" (set ret=%%~tA)
    if "%out%"=="/z" (set ret=%%~zA)
    if "%out%"=="/dp" (set ret=%%~dpA)
    if "%out%"=="/nx" (set ret=%%~nxA)
    if "%out%"=="/fs" (set ret=%%~fsA)
echo ParseFn result: %ret%

goto end
@echo off
:: @echo ::___________________________________________________________________::
:: @echo ::                                                                   ::
:: @echo ::                           ParseFn Help                            ::
:: @echo ::                                                                   ::
:: @echo ::                           Chris Advena                            ::
:: @echo ::___________________________________________________________________::
@echo ParseFn parses a fully qualified path name (e.g., c:\temp\my.bat)
@echo into the requested component, such as drive, path, filename, 
@echo extenstion, etc.
@echo Syntax: /switch filename
@echo where,
@echo   filename is a fully qualified path name including drive, 
@echo   folder(s), file name, and extension
@echo   Select only one switch:
@echo       /f - fully qualified path name
@echo       /d - drive letter only
@echo       /p - path only
@echo       /n - file name only
@echo       /x - extension only
@echo       /s - expanded path contains short names only
@echo       /a - attributes of file
@echo       /t - date/time of file
@echo       /z - size of file
@echo      /dp - drive + path
@echo      /nx - file name + extension
@echo      /fs - full path + short name

:: @echo ::___________________________________________________________________::
:: @echo ::                                                                   ::
:: @echo ::                         ParseFn finished                          ::
:: @echo ::___________________________________________________________________::
:: @echo.

How to set image for bar button with swift?

Only two Lines of code required for this

Swift 3.0

let closeButtonImage = UIImage(named: "ic_close_white")
        navigationItem.rightBarButtonItem = UIBarButtonItem(image: closeButtonImage, style: .plain, target: self, action:  #selector(ResetPasswordViewController.barButtonDidTap(_:)))

func barButtonDidTap(_ sender: UIBarButtonItem)