Programs & Examples On #Slowdown

Call async/await functions in parallel


The original answer makes it difficult (and in some cases impossible) to correctly handle promise rejections. The correct solution is to use Promise.all:

const [someResult, anotherResult] = await Promise.all([someCall(), anotherCall()]);

Original answer:

Just make sure you call both functions before you await either one:

// Call both functions
const somePromise = someCall();
const anotherPromise = anotherCall();

// Await both promises    
const someResult = await somePromise;
const anotherResult = await anotherPromise;

Swift Beta performance: sorting arrays

Swift 4.1 introduces new -Osize optimization mode.

In Swift 4.1 the compiler now supports a new optimization mode which enables dedicated optimizations to reduce code size.

The Swift compiler comes with powerful optimizations. When compiling with -O the compiler tries to transform the code so that it executes with maximum performance. However, this improvement in runtime performance can sometimes come with a tradeoff of increased code size. With the new -Osize optimization mode the user has the choice to compile for minimal code size rather than for maximum speed.

To enable the size optimization mode on the command line, use -Osize instead of -O.

Further reading :

Speed up rsync with Simultaneous/Concurrent File Transfers?

There are a number of alternative tools and approaches for doing this listed arround the web. For example:

  • The NCSA Blog has a description of using xargs and find to parallelize rsync without having to install any new software for most *nix systems.

  • And parsync provides a feature rich Perl wrapper for parallel rsync.

Extreme wait-time when taking a SQL Server database offline

execute the stored procedure sp_who2

This will allow you to see if there is any blocking locks.. kill their should fix it.

using batch echo with special characters

You can escape shell metacharacters with ^:

echo ^<?xml version="1.0" encoding="utf-8" ?^> > myfile.xml

Note that since echo is a shell built-in it doesn't follow the usual conventions regarding quoting, so just quoting the argument will output the quotes instead of removing them.

Is the sizeof(some pointer) always equal to four?

In addition to what people have said about 64-bit (or whatever) systems, there are other kinds of pointer than pointer-to-object.

A pointer-to-member might be almost any size, depending how they're implemented by your compiler: they aren't necessarily even all the same size. Try a pointer-to-member of a POD class, and then a pointer-to-member inherited from one of the base classes of a class with multiple bases. What fun.

How to remove \n from a list element?

From Python3 onwards

map no longer returns a list but a mapObject, thus the answer will look something like

>>> map(lambda x:x.strip(),l)
<map object at 0x7f00b1839fd0>

You can read more about it on What’s New In Python 3.0.

map() and filter() return iterators. If you really need a list, a quick fix is e.g. list(map(...))

So now what are the ways of getting trough this?

Case 1 - The list call over map with a lambda

map returns an iterator. list is a function that can convert an iterator to a list. Hence you will need to wrap a list call around map. So the answer now becomes,

>>> l = ['Name1', '7.3', '6.9', '6.6', '6.6', '6.1', '6.4', '7.3\n']
>>> list(map(lambda x:x.strip(),l))
['Name1', '7.3', '6.9', '6.6', '6.6', '6.1', '6.4', '7.3']

Very good, we get the output. Now we check the amount of time it takes for this piece of code to execute.

$ python3 -m timeit "l = ['Name1', '7.3', '6.9', '6.6', '6.6', '6.1', '6.4', '7.3\n'];list(map(lambda x:x.strip(),l))"
100000 loops, best of 3: 2.22 usec per loop

2.22 microseconds. That is not so bad. But are there more efficient ways?

Case 2 - The list call over map withOUT a lambda

lambda is frowned upon by many in the Python community (including Guido). Apart from that it will greatly reduce the speed of the program. Hence we need to avoid that as much as possible. The toplevel function str.strip. Comes to our aid here.

The map can be re-written without using lambda using str.strip as

>>> list(map(str.strip,l))
['Name1', '7.3', '6.9', '6.6', '6.6', '6.1', '6.4', '7.3']

And now for the times.

$ python3 -m timeit "l = ['Name1', '7.3', '6.9', '6.6', '6.6', '6.1', '6.4', '7.3\n'];list(map(str.strip,l))"
1000000 loops, best of 3: 1.38 usec per loop

Fantastic. You can see the efficiency differences between the two ways. It is nearly 60% faster. Thus the approach without using a lambda is a better choice here.

Case 3 - Following Guidelines, The Regular way

Another important point from What’s New In Python 3.0 is that it advices us to avoid map where possible.

Particularly tricky is map() invoked for the side effects of the function; the correct transformation is to use a regular for loop (since creating a list would just be wasteful).

So we can solve this problem without a map by using a regular for loop.

The trivial way of solving (the brute-force) would be:-

>>> l = ['Name1', '7.3', '6.9', '6.6', '6.6', '6.1', '6.4', '7.3\n']
>>> final_list = []
>>> for i in l:
...     final_list.append(i.strip())
>>> final_list
['Name1', '7.3', '6.9', '6.6', '6.6', '6.1', '6.4', '7.3']

The timing setup

def f():
    l = ['Name1', '7.3', '6.9', '6.6', '6.6', '6.1', '6.4', '7.3\n']
    final_list = []
    for i in l:
import timeit
print(min(timeit.repeat("f()","from __main__ import f")))

And the result.


As you can see the brute-force is a bit slower here. But it is definitely more readable to a common programmer than a map clause.

Case 4 - List Comprehensions

A list comprehension here is also possible and is the same as in Python2.

>>> [i.strip() for i in l]
['Name1', '7.3', '6.9', '6.6', '6.6', '6.1', '6.4', '7.3']

Now for the timings:

$ python3 -m timeit "l = ['Name1', '7.3', '6.9', '6.6', '6.6', '6.1', '6.4', '7.3\n'];[i.strip() for i in l]"
1000000 loops, best of 3: 1.28 usec per loop

As you can see the list-comprehension is more effective than map (even that without a lambda). Hence the thumb rule in Python3 is to use a list comprehension instead of map

Case 5 - In-Place mechanisms and Space Efficiency (T-M-T)

A final way is to make the changes in-place within the list itself. This will save a lot of memory space. This can be done using enumerate.

>>> l = ['Name1', '7.3', '6.9', '6.6', '6.6', '6.1', '6.4', '7.3\n']
>>> for i,s in enumerate(l):
...     l[i] = s.strip()
>>> l
['Name1', '7.3', '6.9', '6.6', '6.6', '6.1', '6.4', '7.3']

The timing result would be 1.4806894720022683. But however this way is space effective.


A comparitive list of timings (Both Python 3.4.3 and Python 3.5.0)

|Case| method          | Py3.4 |Place| Py3.5 |Place|
| 1  | map with lambda | 2.22u | 5   | 2.85u | 5   |
| 2  | map w/o lambda  | 1.38u | 2   | 2.00u | 2   |
| 3  | brute-force     | 1.53u | 4   | 2.22u | 4   |
| 4  | list comp       | 1.28u | 1   | 1.25u | 1   |
| 5  | in-place        | 1.48u | 3   | 2.14u | 3   |

Finally note that the list-comprehension is the best way and the map using lambda is the worst. But again --- ONLY IN PYTHON3

What jsf component can render a div tag?

Apart from the <h:panelGroup> component (which comes as a bit of a surprise to me), you could use a <f:verbatim> tag with the escape parameter set to false to generate any mark-up you want. For example:

<f:verbatim escape="true">
    <div id="blah"></div>

Bear in mind it's a little less elegant than the panelGroup solution, as you have to generate this for both the start and end tags if you want to wrap any of your JSF code with the div tag.

Alternatively, all the major UI Frameworks have a div component tag, or you could write your own.

how to change php version in htaccess in server

To switch to PHP 4.4:

AddHandler application/x-httpd-php4 .php

To switch to PHP 5.0:

AddHandler application/x-httpd-php5 .php

To switch to PHP 5.1:

AddHandler application/x-httpd-php51 .php

To switch to PHP 5.2:

AddHandler application/x-httpd-php52 .php

To switch to PHP 5.3:

AddHandler application/x-httpd-php53 .php

To switch to PHP 5.4:

AddHandler application/x-httpd-php54 .php

To switch to PHP 5.5:

AddHandler application/x-httpd-php55 .php

To switch to PHP 5.6:

AddHandler application/x-httpd-php56 .php

To switch to PHP 7:

AddHandler application/x-httpd-php7 .php

To switch to PHP 7.1:

AddHandler application/x-httpd-php71 .php

How to disable/enable a button with a checkbox if checked

You can use onchangeevent of the checkbox to enable/disable button based on checked value

<input type="submit" name="sendNewSms" class="inputButton" id="sendNewSms" value=" Send " />

<input type="checkbox"  onchange="document.getElementById('sendNewSms').disabled = !this.checked;" />

How to remove the hash from window.location (URL) with JavaScript without page refresh?

How about the following?

window.location.hash=' '

Please note that am setting the hash to a single space and not an empty string.

Setting the hash to an invalid anchor does not cause a refresh either. Such as,


But, I find above solution to be misleading. This seems to indicate that there is an anchor on the given position with the given name although there isn't one. At the same time, using an empty string causes page to move to the top which can be unacceptable at times. Using a space also ensures that whenever the URL is copied and bookmarked and visited again, the page will usually be at the top and the space will be ignored.

And, hey, this is my first answer on StackOverflow. Hope someone finds it useful and it matches the community standards.

JQuery - how to select dropdown item based on value


How to generate java classes from WSDL file

You can use the eclipse plugin as suggested by Oscar earlier. Or if you are a command line person, you can use Apache Axis WSDL2Java tool from command prompt. You can find more details here

Core dumped, but core file is not in the current directory?

My efforts in WSL have been unsuccessful.

For those running on Windows Subsystem for Linux (WSL) there seems to be an open issue at this time for missing core dump files.

The comments indicate that

This is a known issue that we are aware of, it is something we are investigating.

Github issue

Windows Developer Feedback

What's the main difference between int.Parse() and Convert.ToInt32

Have a look in reflector:


public static int Parse(string s)
    return System.Number.ParseInt32(s, NumberStyles.Integer, NumberFormatInfo.CurrentInfo);

which is a call to:

internal static unsafe int ParseInt32(string s, NumberStyles style, NumberFormatInfo info)
    byte* stackBuffer = stackalloc byte[1 * 0x72];
    NumberBuffer number = new NumberBuffer(stackBuffer);
    int num = 0;
    StringToNumber(s, style, ref number, info, false);
    if ((style & NumberStyles.AllowHexSpecifier) != NumberStyles.None)
        if (!HexNumberToInt32(ref number, ref num))
            throw new OverflowException(Environment.GetResourceString("Overflow_Int32"));
        return num;
    if (!NumberToInt32(ref number, ref num))
        throw new OverflowException(Environment.GetResourceString("Overflow_Int32"));
    return num;


public static int ToInt32(string value)
    if (value == null)
        return 0;
    return int.Parse(value, CultureInfo.CurrentCulture);

As the first (Dave M's) comment says.

How to import existing Git repository into another?

I wanted to import only some files from the other repository (XXX) in my case. The subtree was too complicated for me and the other solutions didn't work. This is what I did:

ALL_COMMITS=$(git log --reverse --pretty=format:%H -- ZZZ | tr '\n' ' ')

This gives you a space-separated list of all the commits that affect the files I wanted to import (ZZZ) in reverse order (you might have to add --follow to capture renames as well). I then went into the target repository (YYY), added the other repository (XXX) as remote, did a fetch from it and finally:

git cherry-pick $ALL_COMMITS

which adds all the commits to your branch, you'll thus have all the files with their history and can do whatever you want with them as if they've always been in this repository.

Pandas read in table without headers

In order to read a csv in that doesn't have a header and for only certain columns you need to pass params header=None and usecols=[3,6] for the 4th and 7th columns:

df = pd.read_csv(file_path, header=None, usecols=[3,6])

See the docs

How can I append a query parameter to an existing URL?

There are plenty of libraries that can help you with URI building (don't reinvent the wheel). Here are three to get you started:

Java EE 7

return UriBuilder.fromUri(url).queryParam(key, value).build();


import org.apache.http.client.utils.URIBuilder;
return new URIBuilder(url).addParameter(key, value).build();


import org.springframework.web.util.UriComponentsBuilder;
return UriComponentsBuilder.fromUriString(url).queryParam(key, value).build().toUri();

See also: GIST > URI Builder Tests

MySQL Workbench: "Can't connect to MySQL server on' (10061)" error

I was having same issue, way i have resolved is:

opened the MySQL installer. i was having a Reconfigure link on MYSQL Server row. MYSQL Server having Reconfigure Link

Clicked on it, it does reinstalled MySQL Server. after that opened MySQL Workbench, and it was working fine.

Regular expression to remove HTML tags from a string

You could do it with jsoup

Whitelist whitelist = Whitelist.none();
String cleanStr = Jsoup.clean(yourText, whitelist);

Working Copy Locked

I ended up using export command rather than update command. This is the post-commit hook

"C:\Program Files\VisualSVN Server\bin\svn.exe" export "D:\xampp\htdocs\test-lalala" --quiet --non-interactive --force --username myusername --password mypassword

How to add text to an existing div with jquery

$(function () {_x000D_
  $('#Add').click(function () {_x000D_
<script src=""></script>_x000D_
 <div id="Content">_x000D_
    <button id="Add">Add<button>_x000D_

How to combine two byte arrays

Assuming your byteData array is biger than 32 + byteSalt.length()'re going to it's length, not byteSalt.length. You're trying to copy from beyond the array end.

Short IF - ELSE statement


or in your form:


Who sets response content-type in Spring MVC (@ResponseBody)

I found solution for Spring 3.1. with using @ResponseBody annotation. Here is example of controller using Json output:

@RequestMapping(value = "/getDealers", method = RequestMethod.GET, 
produces = "application/json; charset=utf-8")
public String sendMobileData() {


Extracting time from POSIXct

Here's an update for those looking for a tidyverse method to extract hh:mm::ss.sssss from a POSIXct object. Note that time zone is not included in the output.


How to get the id of the element clicked using jQuery

Since you are loading in the spans via ajax you will have to attach delegate handlers to the events to catch them as they bubble up.


you will want to attach the event to the closest static member you can to increase efficiency.


is better than binding to the document for instance.

This question may help you understand

Direct vs. Delegated - jQuery .on()

Reverse Contents in Array

Procedure :

 1.Take an array.

 2.Then by default function reverse(array_name, array_name + size) .
  reverse(array_name, array_name + size) function exits in algorithm.h header file.

 3.Now print the array. 

 N.B  Here we use new and delete for dynamic memory allocation.

C++ implementation :

using namespace std;

int main()
   int n;

   int *arr = new int[n];

   for(int i=0; i<n; i++)  cin>>arr[i];

   reverse(arr, arr+n);

   for(int i=0; i<n; i++)    cout<<arr[i]<<" ";

   delete[] arr;

   return 0;

How to fix a collation conflict in a SQL Server query?

I had problems with collations as I had most of the tables with Modern_Spanish_CI_AS, but a few, which I had inherited or copied from another Database, had SQL_Latin1_General_CP1_CI_AS collation.

In my case, the easiest way to solve the problem has been as follows:

  1. I've created a copy of the tables which were 'Latin American, using script table as...
  2. The new tables have obviously acquired the 'Modern Spanish' collation of my database
  3. I've copied the data of my 'Latin American' table into the new one, deleted the old one and renamed the new one.

I hope this helps other users.

Changing WPF title bar background color

Here's an example on how to achieve this:

    <Grid DockPanel.Dock="Right"

        <StackPanel Orientation="Horizontal"

            <Button x:Name="MinimizeButton"
                Style="{StaticResource MinimizeButton}" 
                Template="{StaticResource MinimizeButtonControlTemplate}" />

            <Button x:Name="MaximizeButton"
                Style="{DynamicResource MaximizeButton}" 
                Template="{DynamicResource MaximizeButtonControlTemplate}" />

            <Button x:Name="CloseButton"
                Command="{Binding ApplicationCommands.Close}"
                Style="{DynamicResource CloseButton}" 
                Template="{DynamicResource CloseButtonControlTemplate}"/>


Handle Click Events in the code-behind.

For MouseDown -


For Minimize Button -

App.Current.MainWindow.WindowState = WindowState.Minimized;

For DoubleClick and MaximizeClick

if (App.Current.MainWindow.WindowState == WindowState.Maximized)
    App.Current.MainWindow.WindowState = WindowState.Normal;
else if (App.Current.MainWindow.WindowState == WindowState.Normal)
    App.Current.MainWindow.WindowState = WindowState.Maximized;

round() for float in C++

There are 2 problems we are looking at:

  1. rounding conversions
  2. type conversion.

Rounding conversions mean rounding ± float/double to nearest floor/ceil float/double. May be your problem ends here. But if you are expected to return Int/Long, you need to perform type conversion, and thus "Overflow" problem might hit your solution. SO, do a check for error in your function

long round(double x) {
   assert(x >= LONG_MIN-0.5);
   assert(x <= LONG_MAX+0.5);
   if (x >= 0)
      return (long) (x+0.5);
   return (long) (x-0.5);

#define round(x) ((x) < LONG_MIN-0.5 || (x) > LONG_MAX+0.5 ?\
      error() : ((x)>=0?(long)((x)+0.5):(long)((x)-0.5))

from :

How to check the version before installing a package using apt-get?

Linux Mint, Debian 9, Ubuntu 16.04 and older:

Short info:

apt policy <package_name>

Detailed info (With Description and Depends):

apt show <package_name>

convert HTML ( having Javascript ) to PDF using JavaScript

Copy and paste this in your site to provide a link which will convert the page to a PDF page.

<a href="javascript:void(''+window.location))">Convert To PDF</a>

How to distinguish mouse "click" and "drag"

I think the difference is that there is a mousemove between mousedown and mouseup in a drag, but not in a click.

You can do something like this:

const element = document.createElement('div')
element.innerHTML = 'test'
let moved
let downListener = () => {
    moved = false
element.addEventListener('mousedown', downListener)
let moveListener = () => {
    moved = true
element.addEventListener('mousemove', moveListener)
let upListener = () => {
    if (moved) {
    } else {
        console.log('not moved')
element.addEventListener('mouseup', upListener)

// release memory
element.removeEventListener('mousedown', downListener)
element.removeEventListener('mousemove', moveListener)
element.removeEventListener('mouseup', upListener)

How to add extension methods to Enums

All answers are great, but they are talking about adding extension method to a specific type of enum.

What if you want to add a method to all enums like returning an int of current value instead of explicit casting?

public static class EnumExtensions
    public static int ToInt<T>(this T soure) where T : IConvertible//enum
        if (!typeof(T).IsEnum)
            throw new ArgumentException("T must be an enumerated type");

        return (int) (IConvertible) soure;

    //ShawnFeatherly funtion (above answer) but as extention method
    public static int Count<T>(this T soure) where T : IConvertible//enum
        if (!typeof(T).IsEnum)
            throw new ArgumentException("T must be an enumerated type");

        return Enum.GetNames(typeof(T)).Length;

The trick behind IConvertible is its Inheritance Hierarchy see MDSN

Thanks to ShawnFeatherly for his answer

Axios Delete request with body and headers?

I encountered the same problem... I solved it by creating a custom axios instance. and using that to make a authenticated delete request..

const token = localStorage.getItem('token');
const request = axios.create({
        headers: {
            Authorization: token

await request.delete('<your route>, { data: { <your data> }});

Calculate age based on date of birth

 $dob = $this->dateOfBirth; //Datetime 
        $currentDate = new \DateTime();
        $dateDiff = $dob->diff($currentDate);
        $years = $dateDiff->y;
        $months = $dateDiff->m;
        $days = $dateDiff->d;
        $age = $years .' Year(s)';

        if($years === 0) {
            $age = $months .' Month(s)';
            if($months === 0) {
                $age = $days .' Day(s)';
        return $age;

Serialize JavaScript object into JSON string

You can use a named function on the constructor.

MyClass1 = function foo(id, member) { = id;
    this.member = member;

var myobject = new MyClass1("5678999", "text");

console.log( myobject.constructor );

//function foo(id, member) {
// = id;
//    this.member = member;

You could use a regex to parse out 'foo' from myobject.constructor and use that to get the name.

JavaScript null check

I think, testing variables for values you do not expect is not a good idea in general. Because the test as your you can consider as writing a blacklist of forbidden values. But what if you forget to list all the forbidden values? Someone, even you, can crack your code with passing an unexpected value. So a more appropriate approach is something like whitelisting - testing variables only for the expected values, not unexpected. For example, if you expect the data value to be a string, instead of this:

function (data) {
  if (data != null && data !== undefined) {
    // some code here
    // but what if data === false?
    // or data === '' - empty string?

do something like this:

function (data) {
  if (typeof data === 'string' && data.length) {
    // consume string here, it is here for sure
    // cleaner, it is obvious what type you expect
    // safer, less error prone due to implicit coercion

How to use bitmask?

Briefly bitmask helps to manipulate position of multiple values. There is a good example here ;

Bitflags are a method of storing multiple values, which are not mutually exclusive, in one variable. You've probably seen them before. Each flag is a bit position which can be set on or off. You then have a bunch of bitmasks #defined for each bit position so you can easily manipulate it:

    #define LOG_ERRORS            1  // 2^0, bit 0
    #define LOG_WARNINGS          2  // 2^1, bit 1
    #define LOG_NOTICES           4  // 2^2, bit 2
    #define LOG_INCOMING          8  // 2^3, bit 3
    #define LOG_OUTGOING         16  // 2^4, bit 4
    #define LOG_LOOPBACK         32  // and so on...

// Only 6 flags/bits used, so a char is fine
unsigned char flags;

// initialising the flags
// note that assigning a value will clobber any other flags, so you
// should generally only use the = operator when initialising vars.
flags = LOG_ERRORS;
// sets to 1 i.e. bit 0

//initialising to multiple values with OR (|)
// sets to 1 + 2 + 8 i.e. bits 0, 1 and 3

// setting one flag on, leaving the rest untouched
// OR bitmask with the current value
flags |= LOG_INCOMING;

// testing for a flag
// AND with the bitmask before testing with ==

// testing for multiple flags
// as above, OR the bitmasks

// removing a flag, leaving the rest untouched
// AND with the inverse (NOT) of the bitmask
flags &= ~LOG_OUTGOING;

// toggling a flag, leaving the rest untouched
flags ^= LOG_LOOPBACK;


WARNING: DO NOT use the equality operator (i.e. bitflags == bitmask) for testing if a flag is set - that expression will only be true if that flag is set and all others are unset. To test for a single flag you need to use & and == :


if (flags == LOG_WARNINGS) //DON'T DO THIS
if ((flags & LOG_WARNINGS) == LOG_WARNINGS) // The right way
if ((flags & (LOG_INCOMING | LOG_OUTGOING)) // Test for multiple flags set

You can also search C++ Triks

Google Forms file upload complete example

As of October 2016, Google has added a file upload question type in native Google Forms, no Google Apps Script needed. See documentation.

Onclick event to remove default value in a text input field

<input name="Name" value="Enter Your Name" onfocus="freez(this)" onblur="freez(this)">

function freez(obj)
   obj.value='Enter Your Name';
 }else if(obj.value=='Enter Your Name')

PHP filesize MB/KB conversion

A complete example.

    $units = explode(' ','B KB MB GB TB PB');
    echo('file size: ' . format_size(filesize("example.txt")));

    function format_size($size) {

        $mod = 1024;

        for ($i = 0; $size > $mod; $i++) {
            $size /= $mod;

        $endIndex = strpos($size, ".")+3;

        return substr( $size, 0, $endIndex).' '.$units[$i];

_csv.Error: field larger than field limit (131072)

Sometimes, a row contain double quote column. When csv reader try read this row, not understood end of column and fire this raise. Solution is below:

reader = csv.reader(cf, quoting=csv.QUOTE_MINIMAL)

Getting the last revision number in SVN?

This should work in Bash, from a working directory. I've used it in Windows with unixutils installed:

svn info |grep Revision: |cut -c11-

Example of SOAP request authenticated with WS-UsernameToken

Check this one (Password should be password):

<wsse:UsernameToken xmlns:wsu="" wsu:Id="SecurityToken-6138db82-5a4c-4bf7-915f-af7a10d9ae96">
  <wsse:Password Type="">CBb7a2itQDgxVkqYnFtggUxtuqk=</wsse:Password>

Copy/duplicate database without using mysqldump

You can duplicate a table without data by running:



You could write a script that takes the output from SHOW TABLES from one database and copies the schema to another. You should be able to reference schema+table names like:

CREATE TABLE x LIKE other_db.y;

As far as the data goes, you can also do it in MySQL, but it's not necessarily fast. After you've created the references, you can run the following to copy the data:


If you're using MyISAM, you're better off to copy the table files; it'll be much faster. You should be able to do the same if you're using INNODB with per table table spaces.

If you do end up doing an INSERT INTO SELECT, be sure to temporarily turn off indexes with ALTER TABLE x DISABLE KEYS!

EDIT Maatkit also has some scripts that may be helpful for syncing data. It may not be faster, but you could probably run their syncing scripts on live data without much locking.

How to get the current time in Google spreadsheet using script editor?

I considered with timezone in my Google Docs like this:

timezone = "GMT+" + new Date().getTimezoneOffset()/60
var date = Utilities.formatDate(new Date(), timezone, "yyyy-MM-dd HH:mm"); // "yyyy-MM-dd'T'HH:mm:ss'Z'"

my script for Google docs

plot legends without border and with white background

As documented in ?legend you do this like so:

plot(1:10,type = "n")
abline(v=seq(1,10,1), col='grey', lty='dotted')
legend(1, 5, "This legend text should not be disturbed by the dotted grey lines,\nbut the plotted dots should still be visible",box.lwd = 0,box.col = "white",bg = "white")

enter image description here

Line breaks are achieved with the new line character \n. Making the points still visible is done simply by changing the order of plotting. Remember that plotting in R is like drawing on a piece of paper: each thing you plot will be placed on top of whatever's currently there.

Note that the legend text is cut off because I made the plot dimensions smaller (windows.options does not exist on all R platforms).


You need to set a constraint on the table to trigger a "conflict" which you then resolve by doing a replace:

CREATE TABLE data   (id INTEGER PRIMARY KEY, event_id INTEGER, track_id INTEGER, value REAL);
CREATE UNIQUE INDEX data_idx ON data(event_id, track_id);

Then you can issue:


The "SELECT * FROM data" will give you:


Note that the is "3" and not "1" because REPLACE does a DELETE and INSERT, not an UPDATE. This also means that you must ensure that you define all necessary columns or you will get unexpected NULL values.

Filtering by Multiple Specific Model Properties in AngularJS (in OR relationship)

I like to keep is simple when possible. I needed to group by International, filter on all the columns, display the count for each group and hide the group if no items existed.

Plus I did not want to add a custom filter just for something simple like this.

            <tr ng-show="fusa.length > 0"><td colspan="8"><h3>USA ({{fusa.length}})</h3></td></tr>
            <tr ng-repeat="t in fusa = (usa = (vm.assignmentLookups | filter: {isInternational: false}) | filter: vm.searchResultText)">
                <td>{{$index + 1}}</td>
                <td ng-bind-html="vm.highlight(t.title, vm.searchResultText)"></td>
                <td ng-bind-html="vm.highlight(t.genericName, vm.searchResultText)"></td>
                <td ng-bind-html="vm.highlight(t.mechanismsOfAction, vm.searchResultText)"></td>
                <td ng-bind-html="vm.highlight(t.diseaseStateIndication, vm.searchResultText)"></td>
                <td ng-bind-html="vm.highlight(t.assignedTo, vm.searchResultText)"></td>
                <td ng-bind-html="t.lastPublished | date:'medium'"></td>
            <tr ng-show="fint.length > 0"><td colspan="8"><h3>International ({{fint.length}})</h3></td></tr>
            <tr ng-repeat="t in fint = (int = (vm.assignmentLookups | filter: {isInternational: true}) | filter: vm.searchResultText)">
                <td>{{$index + 1}}</td>
                <td ng-bind-html="vm.highlight(t.title, vm.searchResultText)"></td>
                <td ng-bind-html="vm.highlight(t.genericName, vm.searchResultText)"></td>
                <td ng-bind-html="vm.highlight(t.mechanismsOfAction, vm.searchResultText)"></td>
                <td ng-bind-html="vm.highlight(t.diseaseStateIndication, vm.searchResultText)"></td>
                <td ng-bind-html="vm.highlight(t.assignedTo, vm.searchResultText)"></td>
                <td ng-bind-html="t.lastPublished | date:'medium'"></td>

'printf' with leading zeros in C

Your format specifier is incorrect. From the printf() man page on my machine:

0 A zero '0' character indicating that zero-padding should be used rather than blank-padding. A '-' overrides a '0' if both are used;

Field Width: An optional digit string specifying a field width; if the output string has fewer characters than the field width it will be blank-padded on the left (or right, if the left-adjustment indicator has been given) to make up the field width (note that a leading zero is a flag, but an embedded zero is part of a field width);

Precision: An optional period, '.', followed by an optional digit string giving a precision which specifies the number of digits to appear after the decimal point, for e and f formats, or the maximum number of characters to be printed from a string; if the digit string is missing, the precision is treated as zero;

For your case, your format would be %09.3f:

#include <stdio.h>

int main(int argc, char **argv)
  printf("%09.3f\n", 4917.24);
  return 0;


$ make testapp
cc     testapp.c   -o testapp
$ ./testapp 

Note that this answer is conditional on your embedded system having a printf() implementation that is standard-compliant for these details - many embedded environments do not have such an implementation.

Writing JSON object to a JSON file with fs.writeFileSync

I don't think you should use the synchronous approach, asynchronously writing data to a file is better also stringify the output if it's an object.

Note: If output is a string, then specify the encoding and remember the flag options as well.:

const fs = require('fs');
const content = JSON.stringify(output);

fs.writeFile('/tmp/phraseFreqs.json', content, 'utf8', function (err) {
    if (err) {
        return console.log(err);

    console.log("The file was saved!");

Added Synchronous method of writing data to a file, but please consider your use case. Asynchronous vs synchronous execution, what does it really mean?

const fs = require('fs');
const content = JSON.stringify(output);

fs.writeFileSync('/tmp/phraseFreqs.json', content);

Open text file and program shortcut in a Windows batch file

I use

@echo off
Start notepad "filename.txt"

to open the file.

Another example is

@echo off
start chrome "filename.html"

How do I load an HTTP URL with App Transport Security enabled in iOS 9?

If you just want to disable App Transport Policy for local dev servers then the following solutions work well. It's useful when you're unable, or it's impractical, to set up HTTPS (e.g. when using the Google App Engine dev server).

As others have said though, ATP should definitely not be turned off for production apps.

1) Use a different plist for Debug

Copy your Plist file and NSAllowsArbitraryLoads. Use this Plist for debugging.

XCode Debug


2) Exclude local servers

Alternatively, you can use a single plist file and exclude specific servers. However, it doesn't look like you can exclude IP 4 addresses so you might need to use the server name instead (found in System Preferences -> Sharing, or configured in your local DNS).


How to test if a double is an integer

Similar to SkonJeet's answer above, but the performance is better (at least in java):

Double zero = 0d;    
zero.longValue() == zero.doubleValue()

How to get the absolute coordinates of a view

Use This code to find exact X and Y cordinates :

int[] array = new int[2];
if (AppConstants.DEBUG)
    Log.d(AppConstants.TAG, "array  X = " + array[0] + ", Y = " + array[1]);
ViewWhichToBeMovedOnFoundLocation.setTranslationX(array[0] + 21);
ViewWhichToBeMovedOnFoundLocation.setTranslationY(array[1] - 165);

I have added/subtracted some values to adjust my view. Please do these lines only after whole view has been inflated.

How can I wait for a thread to finish with .NET?

I took a little different approach. There is a counter option in previous answers, and I just applied it a bit differently. I was spinning off numerous threads and incremented a counter and decremented a counter as a thread started and stopped. Then in the main method I wanted to pause and wait for threads to complete I did.

while (threadCounter > 0)
    Thread.Sleep(500); // Make it pause for half second so that we don’t spin the CPU out of control.

This is documented in my blog post:

phpMyAdmin + CentOS 6.0 - Forbidden

Edit your httpd.conf file as follows:

# nano /etc/httpd/conf/httpd.conf

Add the following lines here:

<Directory "/usr/share/phpmyadmin">
    Order allow,deny
    Allow from all

Issue the following command:

# service httpd restart

If your problem is not solved then disable your SELinux.

What are some good SSH Servers for windows?

copssh - OpenSSH for Windows

Packages essential Cygwin binaries.

Ant is using wrong java version

Build file:

<target name="print-version"> 
   <echo>Java/JVM version: ${}</echo> 
   <echo>Java/JVM detail version: ${java.version}</echo> 


[echo] Java/JVM version: 1.5
[echo] Java/JVM detail version: 1.5.0_08

Using HTML5/JavaScript to generate and save a file

Here is a tutorial to export files as ZIP:

Before getting started, there is a library to save files, the name of library is fileSaver.js, You can find this library here. Let's get started, Now, include the required libraries:

<script src=""  type="text/javascript"></script>
<script type="text/javascript" src="" ></script>

Now copy this code and this code will download a zip file with a file hello.txt having content Hello World. If everything thing works fine, this will download a file.

<script type="text/javascript">
    var zip = new JSZip();
    zip.file("Hello.txt", "Hello World\n");
    .then(function(content) {
        // see FileSaver.js
        saveAs(content, "");

This will download a file called You can read more here: Received fatal alert: protocol_version

This is due to the fact that you send a TLSv1 handshake, but then you send a message using SSLv2 protocol;

xxx, WRITE: TLSv1 Handshake, length = 75
xxx, WRITE: SSLv2 client hello message, length = 101

This means that the server expects the TLSv1 protocol to be used and will not accept the connection. Try specifying which protocol to use, or post some relevant code so we can have a look

How to suppress binary file matching results in grep

This is an old question and its been answered but I thought I'd put the --binary-files=text option here for anyone who wants to use it. The -I option ignores the binary file but if you want the grep to treat the binary file as a text file use --binary-files=text like so:

bash$ grep -i reset mediaLog*
Binary file mediaLog_dc1.txt matches
bash$ grep --binary-files=text -i reset mediaLog*
mediaLog_dc1.txt:2016-06-29 15:46:02,470 - Media [uploadChunk  ,315] - ERROR - ('Connection aborted.', error(104, 'Connection reset by peer'))
mediaLog_dc1.txt:ConnectionError: ('Connection aborted.', error(104, 'Connection reset by peer'))

How to get just one file from another branch

git checkout branch_name file_name


git checkout master

This will not work if your branch name has a period in it.

git checkout "fix.june" alive.html
error: pathspec 'fix.june' did not match any file(s) known to git.

C++ Array Of Pointers

I would do it something along these lines:

class Foo{

int main(){
  Foo* arrayOfFoo[100]; //[1]

  arrayOfFoo[0] = new Foo; //[2]

[1] This makes an array of 100 pointers to Foo-objects. But no Foo-objects are actually created.

[2] This is one possible way to instantiate an object, and at the same time save a pointer to this object in the first position of your array.

Get generic type of java.util.List

Generally impossible, because List<String> and List<Integer> share the same runtime class.

You might be able to reflect on the declared type of the field holding the list, though (if the declared type does not itself refer to a type parameter whose value you don't know).

Get the device width in javascript

Lumia phones give wrong screen.width (at least on emulator). So maybe Math.min(window.innerWidth || Infinity, screen.width) will work on all devices?

Or something crazier:

for (var i = 100; !window.matchMedia('(max-device-width: ' + i + 'px)').matches; i++) {}
var deviceWidth = i;

Input jQuery get old value before onchange and get value after on change

Just put the initial value into a data attribute when you create the textbox, eg


<input id="my-textbox" type="text" data-initial-value="6" value="6" /> 


$("#my-textbox").change(function () {
 var oldValue = $(this).attr("data-initial-value");
 var newValue = $(this).val();

After installation of Gulp: “no command 'gulp' found”

I solved the issue removing gulp and installing gulp-cli again:

rm /usr/local/bin/gulp
npm install -g gulp-cli

C compile error: "Variable-sized object may not be initialized"

This gives error:

int len;
char str[len]="";

This also gives error:

int len=5;
char str[len]="";

But this works fine:

int len=5;
char str[len]; //so the problem lies with assignment not declaration

You need to put value in the following way:

str[1]='b'; //like that; and not like str="ab";

In Python How can I declare a Dynamic Array

Here's a great method I recently found on a different stack overflow post regarding multi-dimensional arrays, but the answer works beautifully for single dimensional arrays as well:

# Create an 8 x 5 matrix of 0's:
w, h = 8, 5;
MyMatrix = [ [0 for x in range( w )] for y in range( h ) ]  

# Create an array of objects:
MyList = [ {} for x in range( n ) ]

I love this because you can specify the contents and size dynamically, in one line!

One more for the road:

# Dynamic content initialization:
MyFunkyArray = [ x * a + b for x in range ( n ) ]

Installing OpenCV for Python on Ubuntu, getting ImportError: No module named

This seemed to work for me on Max OSX:

conda install -c menpo opencv3=3.1.0

I confirmed that you can import cv2 in python using python2.7 and python3

oracle plsql: how to parse XML and insert into table

    (xml IN CLOB)
        ExtractValue(column_value,'/ROOT/EMPID') AS EMPID
       ,ExtractValue(column_value,'/ROOT/EMPNAME') AS EMPNAME
       ,ExtractValue(column_value,'/ROOT/EMPDETAIL') AS EMPDETAIL
       ,ExtractValue(column_value,'/ROOT/CREATEDBY') AS CREATEDBY
       ,ExtractValue(column_value,'/ROOT/CREATEDDATE') AS CREATEDDATE
    FROM   TABLE(XMLSequence( XMLType(xml))) XMLDUMMAY;


How to get first N elements of a list in C#?

var firstFiveItems = myList.Take(5);

Or to slice:

var secondFiveItems = myList.Skip(5).Take(5);

And of course often it's convenient to get the first five items according to some kind of order:

var firstFiveArrivals = myList.OrderBy(i => i.ArrivalTime).Take(5);

Check if a number is int or float

I like @ninjagecko's answer the most.

This would also work:

for Python 2.x

isinstance(n, (int, long, float)) 

Python 3.x doesn't have long

isinstance(n, (int, float))

there is also type complex for complex numbers

How can I tell Moq to return a Task?

Your method doesn't have any callbacks so there is no reason to use .CallBack(). You can simply return a Task with the desired values using .Returns() and Task.FromResult, e.g.:

MyType someValue=...;

Update 2014-06-22

Moq 4.2 has two new extension methods to assist with this.


    .ThrowsAsync(new InvalidOperationException());

Update 2016-05-05

As Seth Flowers mentions in the other answer, ReturnsAsync is only available for methods that return a Task<T>. For methods that return only a Task,


can be used.

As shown in this answer, in .NET 4.6 this is simplified to .Returns(Task.CompletedTask);, e.g.:


React Js: Uncaught (in promise) SyntaxError: Unexpected token < in JSON at position 0

The solution that worked for me is that:- I moved my data.json file from src to public directory. Then used fetch API to fetch the file.

fetch('./data.json').then(response => {
          return response.json();
        }).then(data => {
          // Work with JSON data here
        }).catch(err => {
          // Do something for an error here
          console.log("Error Reading data " + err);

The problem was that after compiling react app the fetch request looks for the file at URL "http://localhost:3000/data.json" which is actually the public directory of my react app. But unfortunately while compiling react app data.json file is not moved from src to public directory. So we have to explicitly move data.json file from src to public directory.

Regular Expression to get a string between parentheses in Javascript

You need to create a set of escaped (with \) parentheses (that match the parentheses) and a group of regular parentheses that create your capturing group:

var regExp = /\(([^)]+)\)/;_x000D_
var matches = regExp.exec("I expect five hundred dollars ($500).");_x000D_
//matches[1] contains the value between the parentheses_x000D_


  • \( : match an opening parentheses
  • ( : begin capturing group
  • [^)]+: match one or more non ) characters
  • ) : end capturing group
  • \) : match closing parentheses

Here is a visual explanation on RegExplained

"Insufficient Storage Available" even there is lot of free space in device memory

I also had this issue while installating an app after I had uninstalled that. I resolved downloading Lucky Patcher and then click on menu - troubleshooting - remove fixes and backups (insufficient storage available). Please notice you need your device to be rooted.

How can I make the browser wait to display the page until it's fully loaded?

You can hide everything using some css:

  display: none;

and then in javascript assign a function to document.onload to remove that div.

jQuery makes things like this very easy.

What is the Swift equivalent of respondsToSelector?

As mentioned, in Swift most of the time you can achieve what you need with the ? optional unwrapper operator. This allows you to call a method on an object if and only if the object exists (not nil) and the method is implemented.

In the case where you still need respondsToSelector:, it is still there as part of the NSObject protocol.

If you are calling respondsToSelector: on an Obj-C type in Swift, then it works the same as you would expect. If you are using it on your own Swift class, you will need to ensure your class derives from NSObject.

Here's an example of a Swift class that you can check if it responds to a selector:

class Worker : NSObject
    func work() { }
    func eat(food: AnyObject) { }
    func sleep(hours: Int, minutes: Int) { }

let worker = Worker()

let canWork = worker.respondsToSelector(Selector("work"))   // true
let canEat = worker.respondsToSelector(Selector("eat:"))    // true
let canSleep = worker.respondsToSelector(Selector("sleep:minutes:"))    // true
let canQuit = worker.respondsToSelector(Selector("quit"))   // false

It is important that you do not leave out the parameter names. In this example, Selector("sleep::") is not the same as Selector("sleep:minutes:").

Serialize an object to XML

All upvoted answers above are correct. This is just simplest version:

private string Serialize(Object o)
    using (var writer = new StringWriter())
        new XmlSerializer(o.GetType()).Serialize(writer, o);
        return writer.ToString();

Greater than and less than in one statement

Several third-party libraries have classes encapsulating the concept of a range, such as Apache commons-lang's Range (and subclasses).

Using classes such as this you could express your constraint similar to:

if (new IntRange(0, 5).contains(orderBean.getFiles().size())
// (though actually Apache's Range is INclusive, so it'd be new Range(1, 4) - meh

with the added bonus that the range object could be defined as a constant value elsewhere in the class.

However, without pulling in other libraries and using their classes, Java's strong syntax means you can't massage the language itself to provide this feature nicely. And (in my own opinion), pulling in a third party library just for this small amount of syntactic sugar isn't worth it.


You can also just change the build variant to Debug and you should be good to goenter image description here

Android Studio - Device is connected but 'offline'

  • Restart adb by issuing these commands in cmd

    adb kill-server to kill existing adb session

    followed by adb start-server to start a new adb session
  • Disable and re-enable USB debugging on the phone and accept RSA fingerprints if asked by phone
  • Rebooting the phone if it still doesn't work.

If all above don't solve your problem, you may try delete environment variable named "ANDROID_SDK_HOME". It really solved my problem. Hope it Help you!

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

The native system packages installed with python installation in Debian based systems can be found at :


In OSX - /Library/Python/2.7/site-packages

by using this small code :

from distutils.sysconfig import get_python_lib
print get_python_lib()

However, the list of packages installed via pip can be found at :


Or one can simply write the following command to list all paths where python packages are.

>>> import site; site.getsitepackages()
['/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages']

Note: the location might vary based on your OS, like in OSX

>>> import site; site.getsitepackages()
['/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/site-python', '/Library/Python/2.7/site-packages']

How to store token in Local or Session Storage in Angular 2?

Save to local storage

localStorage.setItem('currentUser', JSON.stringify({ token: token, name: name }));

Load from local storage

var currentUser = JSON.parse(localStorage.getItem('currentUser'));
var token = currentUser.token; // your token

For more I suggest you go through this tutorial: Angular 2 JWT Authentication Example & Tutorial

How to properly exit a C# application?

I know this is not the problem you had, however another reason this could happen is you have a non background thread open in your application.

using System;
using System.Threading;
using System.Windows.Forms;

namespace Sandbox_Form
    static class Program
        private static Thread thread;

        static void Main()

            thread = new Thread(BusyWorkThread);
            thread.IsBackground = false;

            Application.Run(new Form());


        public static void BusyWorkThread()
            while (true)

When IsBackground is false it will keep your program open till the thread completes, if you set IsBackground to true the thread will not keep the program open. Things like BackgroundWoker, ThreadPool, and Task all internally use a thread with IsBackground set to true.

How can I map "insert='false' update='false'" on a composite-id key-property which is also used in a one-to-many FK?

"Dino TW" has provided the link to the comment Hibernate Mapping Exception : Repeated column in mapping for entity which has the vital information.

The link hints to provide "inverse=true" in the set mapping, I tried it and it actually works. It is such a rare situation wherein a Set and Composite key come together. Make inverse=true, we leave the insert & update of the table with Composite key to be taken care by itself.

Below can be the required mapping,

<class name="com.example.CompanyEntity" table="COMPANY">
    <id name="id" column="COMPANY_ID"/>
    <set name="names" inverse="true" table="COMPANY_NAME" cascade="all-delete-orphan" fetch="join" batch-size="1" lazy="false">
        <key column="COMPANY_ID" not-null="true"/>
        <one-to-many entity-name="vendorName"/>

ReadFile in Base64 Nodejs

I think that the following example demonstrates what you need:

The essence of the article is this code part:

var fs = require('fs');

// function to encode file data to base64 encoded string
function base64_encode(file) {
    // read binary data
    var bitmap = fs.readFileSync(file);
    // convert binary data to base64 encoded string
    return new Buffer(bitmap).toString('base64');

// function to create file from base64 encoded string
function base64_decode(base64str, file) {
    // create buffer object from base64 encoded string, it is important to tell the constructor that the string is base64 encoded
    var bitmap = new Buffer(base64str, 'base64');
    // write buffer to file
    fs.writeFileSync(file, bitmap);
    console.log('******** File created from base64 encoded string ********');

// convert image to base64 encoded string
var base64str = base64_encode('kitten.jpg');
// convert base64 string back to image 
base64_decode(base64str, 'copy.jpg');

Empty brackets '[]' appearing when using .where

You can use the lower function:


As a comment: Work on your question. The title isn't terribly informative, and you drop a big chunk of code at the end that is irrelevant to your question.

Detect whether Office is 32bit or 64bit via the registry

EDIT : Solution without touching RegistryKeys - im Sorry Op.

I found out that there is a solution in C# - the original can be found here :

I modified it a bit for my needs.

just pass the correct outlookPath to GetOutlookBitness()

  public enum BinaryType : uint

        SCS_32BIT_BINARY = 0, // A 32-bit Windows-based application
        SCS_64BIT_BINARY = 6, // A 64-bit Windows-based application.
        SCS_DOS_BINARY = 1, // An MS-DOS – based application
        SCS_OS216_BINARY = 5, // A 16-bit OS/2-based application
        SCS_PIF_BINARY = 3, // A PIF file that executes an MS-DOS – based application
        SCS_POSIX_BINARY = 4, // A POSIX – based application
        SCS_WOW_BINARY = 2 // A 16-bit Windows-based application

    static extern bool GetBinaryType(string lpApplicationName, out BinaryType lpBinaryType);

    public int GetOutlookBitness(string FilePath)
        int bitness = 0;

        if (File.Exists(FilePath))
            BinaryType type;
            GetBinaryType(FilePath, out type);

            switch (type)
                case BinaryType.SCS_32BIT_BINARY:
                    bitness = 32;
                case BinaryType.SCS_64BIT_BINARY:
                    bitness = 64;

        return bitness;


Does Arduino use C or C++?

Arduino doesn't run either C or C++. It runs machine code compiled from either C, C++ or any other language that has a compiler for the Arduino instruction set.

C being a subset of C++, if Arduino can "run" C++ then it can "run" C.

If you don't already know C nor C++, you should probably start with C, just to get used to the whole "pointer" thing. You'll lose all the object inheritance capabilities though.

Python != operation vs "is not"

== is an equality test. It checks whether the right hand side and the left hand side are equal objects (according to their __eq__ or __cmp__ methods.)

is is an identity test. It checks whether the right hand side and the left hand side are the very same object. No methodcalls are done, objects can't influence the is operation.

You use is (and is not) for singletons, like None, where you don't care about objects that might want to pretend to be None or where you want to protect against objects breaking when being compared against None.

Invalid hook call. Hooks can only be called inside of the body of a function component

Yesterday, I shortened the code (just added <Provider store={store}>) and still got this invalid hook call problem. This made me suddenly realized what mistake I did: I didn't install the react-redux software in that folder.

I had installed this software in the other project folder, so I didn't realize this one also needed it. After installing it, the error is gone.

Why is it bad style to `rescue Exception => e` in Ruby?

The real rule is: Don't throw away exceptions. The objectivity of the author of your quote is questionable, as evidenced by the fact that it ends with

or I will stab you

Of course, be aware that signals (by default) throw exceptions, and normally long-running processes are terminated through a signal, so catching Exception and not terminating on signal exceptions will make your program very hard to stop. So don't do this:

#! /usr/bin/ruby

while true do
    line = STDIN.gets
    # heavy processing
  rescue Exception => e
    puts "caught exception #{e}! ohnoes!"

No, really, don't do it. Don't even run that to see if it works.

However, say you have a threaded server and you want all exceptions to not:

  1. be ignored (the default)
  2. stop the server (which happens if you say thread.abort_on_exception = true).

Then this is perfectly acceptable in your connection handling thread:

  # do stuff
rescue Exception => e
  myLogger.error("uncaught #{e} exception while handling connection: #{e.message}")
    myLogger.error("Stack trace: #{ {|l| "  #{l}\n"}.join}")

The above works out to a variation of Ruby's default exception handler, with the advantage that it doesn't also kill your program. Rails does this in its request handler.

Signal exceptions are raised in the main thread. Background threads won't get them, so there is no point in trying to catch them there.

This is particularly useful in a production environment, where you do not want your program to simply stop whenever something goes wrong. Then you can take the stack dumps in your logs and add to your code to deal with specific exception further down the call chain and in a more graceful manner.

Note also that there is another Ruby idiom which has much the same effect:

a = do_something rescue "something else"

In this line, if do_something raises an exception, it is caught by Ruby, thrown away, and a is assigned "something else".

Generally, don't do that, except in special cases where you know you don't need to worry. One example:

debugger rescue nil

The debugger function is a rather nice way to set a breakpoint in your code, but if running outside a debugger, and Rails, it raises an exception. Now theoretically you shouldn't be leaving debug code lying around in your program (pff! nobody does that!) but you might want to keep it there for a while for some reason, but not continually run your debugger.


  1. If you've run someone else's program that catches signal exceptions and ignores them, (say the code above) then:

    • in Linux, in a shell, type pgrep ruby, or ps | grep ruby, look for your offending program's PID, and then run kill -9 <PID>.
    • in Windows, use the Task Manager (CTRL-SHIFT-ESC), go to the "processes" tab, find your process, right click it and select "End process".
  2. If you are working with someone else's program which is, for whatever reason, peppered with these ignore-exception blocks, then putting this at the top of the mainline is one possible cop-out:

    %W/INT QUIT TERM/.each { |sig| trap sig,"SYSTEM_DEFAULT" }

    This causes the program to respond to the normal termination signals by immediately terminating, bypassing exception handlers, with no cleanup. So it could cause data loss or similar. Be careful!

  3. If you need to do this:

    rescue Exception => e

    you can actually do this:


    In the second case, critical cleanup will be called every time, whether or not an exception is thrown.

Example of Mockito's argumentCaptor

I agree with what @fge said, more over. Lets look at example. Consider you have a method:

class A {
    public void foo(OtherClass other) {
        SomeData data = new SomeData("Some inner data");

Now if you want to check the inner data you can use the captor:

// Create a mock of the OtherClass
OtherClass other = mock(OtherClass.class);

// Run the foo method with the mock
new A().foo(other);

// Capture the argument of the doSomething function
ArgumentCaptor<SomeData> captor = ArgumentCaptor.forClass(SomeData.class);
verify(other, times(1)).doSomething(captor.capture());

// Assert the argument
SomeData actual = captor.getValue();
assertEquals("Some inner data", actual.innerData);

How do I "decompile" Java class files?

JAD doesn't work for me (Ubuntu 11.10 issue) so I've moved forward and sopped on JODO. At least it has Open Java source code and been able to decompile my .class properly.

I recommend to check out 'branches/generic' branch first. The trunks is not stable.

WindowsError: [Error 126] The specified module could not be found

NestedCaveats solution worked for me.

Imported my .dll files before importing torch and gpytorch, and all went smoothly.

So I just want to add that its not just importing pytorch but I can confirm that torch and gpytorch have this issue as well. I'd assume it covers any other torch-related libraries.

Select Rows with id having even number

--This is for oracle


How to enter command with password for git pull?

I did not find the answer to my question after searching Google & stackoverflow for a while so I would like to share my solution here.

git config --global credential.helper "/bin/bash /"
echo '#!/bin/bash' > /
echo "sleep 1" >> /
echo "echo username=$SERVICE_USER" >> /
echo "echo password=$SERVICE_PASS" >> /

# to test it
git clone

I did it for Windows too. Full answer here

Add a new column to existing table in a migration

If you're using Laravel 5, the command would be;

php artisan make:migration add_paid_to_users

All of the commands for making things (controllers, models, migrations etc) have been moved under the make: command.

php artisan migrate is still the same though.

How to create a foreign key in phpmyadmin

When you create table than you can give like follows.

CREATE TABLE categories(
cat_id int not null auto_increment primary key,
cat_name varchar(255) not null,
cat_description text

CREATE TABLE products(
   prd_id int not null auto_increment primary key,
   prd_name varchar(355) not null,
   prd_price decimal,
   cat_id int not null,
   FOREIGN KEY fk_cat(cat_id)
   REFERENCES categories(cat_id)

and when after the table create like this

   ALTER table_name
    ADD CONSTRAINT constraint_name
    FOREIGN KEY foreign_key_name(columns)
    REFERENCES parent_table(columns)
    ON DELETE action
    ON UPDATE action;

Following on example for it.

    vdr_id int not null auto_increment primary key,
    vdr_name varchar(255)

ALTER TABLE products 
ADD COLUMN vdr_id int not null AFTER cat_id;

To add a foreign key to the products table, you use the following statement:

ALTER TABLE products
ADD FOREIGN KEY fk_vendor(vdr_id)
REFERENCES vendors(vdr_id)

For drop the key

ALTER TABLE table_name 
DROP FOREIGN KEY constraint_name;

Hope this help to learn FOREIGN keys works

Web Service vs WCF Service

This answer is based on an article that no longer exists:

Summary of article:

"Basically, WCF is a service layer that allows you to build applications that can communicate using a variety of communication mechanisms. With it, you can communicate using Peer to Peer, Named Pipes, Web Services and so on.

You can’t compare them because WCF is a framework for building interoperable applications. If you like, you can think of it as a SOA enabler. What does this mean?

Well, WCF conforms to something known as ABC, where A is the address of the service that you want to communicate with, B stands for the binding and C stands for the contract. This is important because it is possible to change the binding without necessarily changing the code. The contract is much more powerful because it forces the separation of the contract from the implementation. This means that the contract is defined in an interface, and there is a concrete implementation which is bound to by the consumer using the same idea of the contract. The datamodel is abstracted out."

... later ...

"should use WCF when we need to communicate with other communication technologies (e,.g. Peer to Peer, Named Pipes) rather than Web Service"

Find all tables containing column with specified name - MS SQL Server

This should work:

SELECT name 
FROM sysobjects 
              FROM syscolumns 
              WHERE name like '%column_name%' )

What are all the differences between src and data-src attributes?

If you want the image to load and display a particular image, then use .src to load that image URL.

If you want a piece of meta data (on any tag) that can contain a URL, then use data-src or any data-xxx that you want to select.

MDN documentation on data-xxxx attributes:

Example of src on an image tag where the image loads the JPEG for you and displays it:

<img id="myImage" src="">

    var imageUrl = document.getElementById("myImage").src;

Example of 'data-src' on a non-image tag where the image is not loaded yet - it's just a piece of meta data on the div tag:

<div id="myDiv" data-src="">

    // in all browsers
    var imageUrl = document.getElementById("myDiv").getAttribute("data-src");

    // or in modern browsers
    var imageUrl = document.getElementById("myDiv").dataset.src;

Example of data-src on an image tag used as a place to store the URL of an alternate image:

<img id="myImage" src="" data-src="">

    var item = document.getElementById("myImage");
    // switch the image to the URL specified in data-src
    item.src = item.dataset.src;

How can I clear console

For pure C++

You can't. C++ doesn't even have the concept of a console.

The program could be printing to a printer, outputting straight to a file, or being redirected to the input of another program for all it cares. Even if you could clear the console in C++, it would make those cases significantly messier.

See this entry in the comp.lang.c++ FAQ:


If it still makes sense to clear the console in your program, and you are interested in operating system specific solutions, those do exist.

For Windows (as in your tag), check out this link:

Edit: This answer previously mentioned using system("cls");, because Microsoft said to do that. However it has been pointed out in the comments that this is not a safe thing to do. I have removed the link to the Microsoft article because of this problem.

Libraries (somewhat portable)

ncurses is a library that supports console manipulation:

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

If you are using NVARCHAR just because a system stored procedure requires it, the most frequent occurrence being inexplicably sp_executesql, and your dynamic SQL is very long, you would be better off from performance perspective doing all string manipulations (concatenation, replacement etc.) in VARCHAR then converting the end result to NVARCHAR and feeding it into the proc parameter. So no, do not always use NVARCHAR!

Unrecognized attribute 'targetFramework'. Note that attribute names are case-sensitive

If you compile the files and the value of the "targetFramework" is set as being a particular version i.e. 4.0,

Make sure the host is running .net framework as the same version stated.

If not, download the .net framework.

After downloading, if it is not automatic being set in the IIS manager to be using the extension of the newly downloaded version of .net framework,

add the extension manually by going to the folder of the recently downloaded .net framework THROUGH IIS manager:

1.right-click website folder

2.go to "Properties"

3.under "virtual directory" , click "configuration"

4.edit the executable path of extension ".aspx" (of which the path being pointed to version other than the version of the recently downloaded .net framework) to the correct path which is the folder of the NEWLY downloaded version of .net framework and then select the "aspnet_isapi.dll" file. ok!

How to check if a function exists on a SQL database

I've found you can use a very non verbose and straightforward approach to checking for the existence various SQL Server objects this way:

IF OBJECTPROPERTY (object_id('schemaname.scalarfuncname'), 'IsScalarFunction') = 1
IF OBJECTPROPERTY (object_id('schemaname.tablefuncname'), 'IsTableFunction') = 1
IF OBJECTPROPERTY (object_id('schemaname.procname'), 'IsProcedure') = 1

This is based on the OBJECTPROPERTY function which is available in SQL 2005+. The MSDN article can be found here.

The OBJECTPROPERTY function uses the following signature:

OBJECTPROPERTY ( id , property ) 

You pass a literal value into the property parameter, designating the type of object you are looking for. There's a massive list of values you can supply.

Hibernate: Automatically creating/updating the db tables based on entity classes

In support to @thorinkor's answer I would extend my answer to use not only @Table (name = "table_name") annotation for entity, but also every child variable of entity class should be annotated with @Column(name = "col_name"). This results into seamless updation to the table on the go.

For those who are looking for a Java class based hibernate config, the rule applies in java based configurations also(NewHibernateUtil). Hope it helps someone else.

How to store images in mysql database using php

(IF YOU HAVE ANY QUERY CONTACT:[email protected])

CREATE TABLE  `images` (
  `id` int(100) NOT NULL AUTO_INCREMENT,
  `name` varchar(100) NOT NULL,
  `image` longblob NOT NULL,
  PRIMARY KEY (`id`)

<!-- this form is user to store images-->
<form action="index.php" method="post"  enctype="multipart/form-data">
Enter the Image Name:<input type="text" name="image_name" id="" /><br />

<input name="image" id="image" accept="image/JPEG" type="file"><br /><br />
<input type="submit" value="submit" name="submit" />
<br /><br />
<!-- this form is user to display all the images-->
<form action="index.php" method="post"  enctype="multipart/form-data">
Retrive all the images:
<input type="submit" value="submit" name="retrive" />

//connect to database.db name is images
        mysql_connect("", "", "") OR DIE (mysql_error());
        mysql_select_db ("") OR DIE ("Unable to select db".mysql_error());
//to retrive send the page to another page


//to upload
if(isset($_FILES['image'])) {
        $fp=addslashes(file_get_contents($_FILES['image']['tmp_name'])); //will store the image to fp
                // our sql query
                $sql = "INSERT INTO images VALUES('null', '{$name}','{$fp}');";
                            mysql_query($sql) or die("Error in Query insert: " . mysql_error());

    //connect to database.db name = images
         mysql_connect("localhost", "root", "") OR DIE (mysql_error());
        mysql_select_db ("image") OR DIE ("Unable to select db".mysql_error());
//display all the image present in the database

        $sql="select * from images";

                  $msg.= '<a href="search.php?id='.$id.'"><img src="data:image/jpeg;base64,'.base64_encode($row['image']). ' " />   </a>';

            $msg.="Query failed";
echo $msg;

Kill detached screen session

"kill" will only kill one screen window. To "kill" the complete session, use quit.


$ screen -X -S [session # you want to kill] quit

For dead sessions use: $ screen -wipe

.htaccess 301 redirect of single page

If you prefer to use the simplest possible solution to a problem, an alternative to RedirectMatch is, the more basic, Redirect directive.

It does not use pattern matching and so is more explicit and easier for others to understand.


<IfModule mod_alias.c>

#Repoint old contact page to new contact page:
Redirect 301 /contact.php


Query strings should be carried over because the docs say:

Additional path information beyond the matched URL-path will be appended to the target URL.

How do I add a bullet symbol in TextView?

This worked for me:

<string name="text_with_bullet">Text with a \u2022</string>

How do I replace text inside a div element?

function showPanel(fieldName) {
  var fieldNameElement = document.getElementById(field_name);

  var newText = document.createTextNode("New Text");

Enable VT-x in your BIOS security settings (refer to documentation for your computer)

No restart, no BIOS needed in my case. I have downloaded and installed the latest version of HAXM from the releases: HAXM releases

Set and Get Methods in java?

this is the code for set method

public void setAge(int age){
  this.age = age;

Display/Print one column from a DataFrame of Series in Pandas

Not sure what you are really after but if you want to print exactly what you have you can do:

Option 1



Option 2

for v in df['Item']:


How to delete columns in numpy.array

Example from the numpy documentation:

>>> a = numpy.array([[ 0,  1,  2,  3],
               [ 4,  5,  6,  7],
               [ 8,  9, 10, 11],
               [12, 13, 14, 15]])

>>> numpy.delete(a, numpy.s_[1:3], axis=0)                       # remove rows 1 and 2

array([[ 0,  1,  2,  3],
       [12, 13, 14, 15]])

>>> numpy.delete(a, numpy.s_[1:3], axis=1)                       # remove columns 1 and 2

array([[ 0,  3],
       [ 4,  7],
       [ 8, 11],
       [12, 15]])

How can I compare two ordered lists in python?

If you want to just check if they are identical or not, a == b should give you true / false with ordering taken into account.

In case you want to compare elements, you can use numpy for comparison

c = (numpy.array(a) == numpy.array(b))

Here, c will contain an array with 3 elements all of which are true (for your example). In the event elements of a and b don't match, then the corresponding elements in c will be false.

Finding the length of a Character Array in C

You can use strlen


You can code it yourself so you understand how it works

size_t my_strlen(const char *str)
  size_t i;

  for (i = 0; str[i]; i++);
  return i;

if you want the size of the array then you use sizeof

char urarray[255];
printf("%zu", sizeof(urarray));

ERROR 1044 (42000): Access denied for user ''@'localhost' to database 'db'

You might want to try the full login command:

mysql -h host -u root -p 

where host would be

Do this just to make sure cooperation exists.

Using mysql -u root -p allows me to do a a lot of database searching, but refuses any database creation due to a path setting.

Changing the URL in react-router v4 without using Redirect or Link

I'm using this to redirect with React Router v4:


Hope it work for you ;)

Setting a property with an EventTrigger

Just create your own action.

namespace WpfUtil
    using System.Reflection;
    using System.Windows;
    using System.Windows.Interactivity;

    /// <summary>
    /// Sets the designated property to the supplied value. TargetObject
    /// optionally designates the object on which to set the property. If
    /// TargetObject is not supplied then the property is set on the object
    /// to which the trigger is attached.
    /// </summary>
    public class SetPropertyAction : TriggerAction<FrameworkElement>
        // PropertyName DependencyProperty.

        /// <summary>
        /// The property to be executed in response to the trigger.
        /// </summary>
        public string PropertyName
            get { return (string)GetValue(PropertyNameProperty); }
            set { SetValue(PropertyNameProperty, value); }

        public static readonly DependencyProperty PropertyNameProperty
            = DependencyProperty.Register("PropertyName", typeof(string),

        // PropertyValue DependencyProperty.

        /// <summary>
        /// The value to set the property to.
        /// </summary>
        public object PropertyValue
            get { return GetValue(PropertyValueProperty); }
            set { SetValue(PropertyValueProperty, value); }

        public static readonly DependencyProperty PropertyValueProperty
            = DependencyProperty.Register("PropertyValue", typeof(object),

        // TargetObject DependencyProperty.

        /// <summary>
        /// Specifies the object upon which to set the property.
        /// </summary>
        public object TargetObject
            get { return GetValue(TargetObjectProperty); }
            set { SetValue(TargetObjectProperty, value); }

        public static readonly DependencyProperty TargetObjectProperty
            = DependencyProperty.Register("TargetObject", typeof(object),

        // Private Implementation.

        protected override void Invoke(object parameter)
            object target = TargetObject ?? AssociatedObject;
            PropertyInfo propertyInfo = target.GetType().GetProperty(

            propertyInfo.SetValue(target, PropertyValue);

In this case I'm binding to a property called DialogResult on my viewmodel.


            <i:EventTrigger EventName="Click">
                <wpf:SetPropertyAction PropertyName="DialogResult" TargetObject="{Binding}"
                                       PropertyValue="{x:Static mvvm:DialogResult.Cancel}"/>


error: function returns address of local variable

Neither malloc or call by reference are needed. You can declare a pointer within the function and set it to the string/array you'd like to return.

Using @Gewure's code as the basis:

char *getStringNoMalloc(void){
    char string[100] = {};
    char *s_ptr = string;

    strcat(string, "bla");
    strcat(string, "/");
    strcat(string, "blub");
    //INSIDE this function "string" is OK
    printf("string : '%s'\n", string);

    return s_ptr; 

works perfectly.

With a non-loop version of the code in the original question:

char *foo(int x){    
    char a[1000];
    char *a_ptr = a;
    char *b = "blah";       

    strcpy(a, b);

    return a_ptr;

How can I label points in this scatterplot?

You should use labels attribute inside plot function and the value of this attribute should be the vector containing the values that you want for each point to have.

How to convert a JSON string to a Map<String, String> with Jackson JSON

The following works for me:

Map<String, String> propertyMap = getJsonAsMap(json);

where getJsonAsMap is defined like so:

public HashMap<String, String> getJsonAsMap(String json)
        ObjectMapper mapper = new ObjectMapper();
        TypeReference<Map<String,String>> typeRef = new TypeReference<Map<String,String>>() {};
        HashMap<String, String> result = mapper.readValue(json, typeRef);

        return result;
    catch (Exception e)
        throw new RuntimeException("Couldnt parse json:" + json, e);

Note that this will fail if you have child objects in your json (because they're not a String, they're another HashMap), but will work if your json is a key value list of properties like so:

    "client_id": "my super id",
    "exp": 1481918304,
    "iat": "1450382274",
    "url": ""

SQL Server : Columns to Rows

I needed a solution to convert columns to rows in Microsoft SQL Server, without knowing the colum names (used in trigger) and without dynamic sql (dynamic sql is too slow for use in a trigger).

I finally found this solution, which works fine:

    attr.insRow.value('local-name(.)', 'nvarchar(128)') as FieldName,
    attr.insRow.value('.', 'nvarchar(max)') as FieldValue 
FROM ( Select      
          i.ID as PK,
          i.LastModifiedBy as Username,
          convert(xml, (select i.* for xml raw)) as insRowCol
       FROM inserted as i
     ) as insRowTbl
CROSS APPLY insRowTbl.insRowCol.nodes('/row/@*') as attr(insRow)

As you can see, I convert the row into XML (Subquery select i,* for xml raw, this converts all columns into one xml column)

Then I CROSS APPLY a function to each XML attribute of this column, so that I get one row per attribute.

Overall, this converts columns into rows, without knowing the column names and without using dynamic sql. It is fast enough for my purpose.

(Edit: I just saw Roman Pekar answer above, who is doing the same. I used the dynamic sql trigger with cursors first, which was 10 to 100 times slower than this solution, but maybe it was caused by the cursor, not by the dynamic sql. Anyway, this solution is very simple an universal, so its definitively an option).

I am leaving this comment at this place, because I want to reference this explanation in my post about the full audit trigger, that you can find here:

An unhandled exception was generated during the execution of the current web request

In my case, I created a new project and when I ran it the first time, it gave me the following error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

So my solution was to go to the Package Manager Console inside the Visual Studio and run:Update-Package

Problem solved!!

In Javascript, how to conditionally add a member to an object?

Define a var by let and just assign new property

let msg = {
    to: "[email protected]",
    from: "[email protected]",
    subject: "Contact form",    

if (file_uploaded_in_form) { // the condition goes here
    msg.attachments = [ // here 'attachments' is the new property added to msg Javascript object
        content: "attachment",
        filename: "filename",
        type: "mime_type",
        disposition: "attachment",

Now the msg become

    to: "[email protected]",
    from: "[email protected]",
    subject: "Contact form",
    attachments: [
        content: "attachment",
        filename: "filename",
        type: "mime_type",
        disposition: "attachment",

In my opinion this is very simple and easy solution.

How to URL encode a string in Ruby

If you want to "encode" a full URL without having to think about manually splitting it into its different parts, I found the following worked in the same way that I used to use URI.encode:


Angular 4 HttpClient Query Parameters

If you have an object that can be converted to {key: 'stringValue'} pairs, you can use this shortcut to convert it:

this._Http.get(myUrlString, {params: {...myParamsObject}});

I just love the spread syntax!

React - how to pass state to another component

Move all of your state and your handleClick function from Header to your MainWrapper component.

Then pass values as props to all components that need to share this functionality.

class MainWrapper extends React.Component {
    constructor() {
        this.state = {
            sidbarPushCollapsed: false,
            profileCollapsed: false
        this.handleClick = this.handleClick.bind(this);
    handleClick() {
            sidbarPushCollapsed: !this.state.sidbarPushCollapsed,
            profileCollapsed: !this.state.profileCollapsed

    render() {
        return (
               profileCollapsed={this.state.profileCollapsed} />

Then in your Header's render() method, you'd use this.props:

<button type="button" id="sidbarPush" onClick={this.props.handleClick} profile={this.props.profileCollapsed}>

Getting Excel to refresh data on sheet from within VBA

The following lines will do the trick:

ActiveSheet.EnableCalculation = False  
ActiveSheet.EnableCalculation = True  

Edit: The .Calculate() method will not work for all functions. I tested it on a sheet with add-in array functions. The production sheet I'm using is complex enough that I don't want to test the .CalculateFull() method, but it may work.

How to have css3 animation to loop forever

I stumbled upon the same problem: a page with many independent animations, each one with its own parameters, which must be repeated forever.

Merging this clue with this other clue I found an easy solution: after the end of all your animations the wrapping div is restored, forcing the animations to restart.

All you have to do is to add these few lines of Javascript, so easy they don't even need any external library, in the <head> section of your page:

var container = document.getElementById('content');
var tmp = container.innerHTML;
container.innerHTML= tmp;
}, 35000 // length of the whole show in milliseconds

BTW, the closing </head> in your code is misplaced: it must be before the starting <body>.

How do I style appcompat-v7 Toolbar like Theme.AppCompat.Light.DarkActionBar?

The recommended way to style the Toolbar for a Light.DarkActionBar clone would be to use Theme.AppCompat.Light.DarkActionbar as parent/app theme and add the following attributes to the style to hide the default ActionBar:

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <item name="windowActionBar">false</item>
    <item name="windowNoTitle">true</item>

Then use the following as your Toolbar:


        app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

For further modifications, you would create styles extending ThemeOverlay.AppCompat.Dark.ActionBar and ThemeOverlay.AppCompat.Light replacing the ones within AppBarLayout->android:theme and Toolbar->app:popupTheme. Also note that this will pick up your ?attr/colorPrimary if you have set it in your main style so you might get a different background color.

You will find a good example of this is in the current project template with an Empty Activity of Android Studio (1.4+).

How do I use checkboxes in an IF-THEN statement in Excel VBA 2010?

Sub Datainput()
'Checkbox values are 0 (false), 1 (true), 2 (changed or grey)
    If activesheet.CheckBoxes("Check Box 1").value = 1 then
        Msgbox ("Yay")
        Else: Msgbox("Aww")
    End if
End Sub

How I can delete in VIM all text from current line to end of file?

Just add another way , in normal mode , type ctrl+v then G, select the rest, then D, I don't think it is effective , you should do like @Ed Guiness, head -n 20 > filename in linux.

Error during SSL Handshake with remote server

I have 2 servers setup on docker, reverse proxy & web server. This error started happening for all my websites all of a sudden after 1 year. When setting up earlier, I generated a self signed certificate on the web server.

So, I had to generate the SSL certificate again and it started working...

openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ssl.key -out ssl.crt

How do I use .toLocaleTimeString() without displaying seconds?

I've also been looking for solution to this problem, here's what I eventually came up with:

function getTimeStr() {
    var dt = new Date();
    var d = dt.toLocaleDateString();
    var t = dt.toLocaleTimeString();
    t = t.replace(/\u200E/g, '');
    t = t.replace(/^([^\d]*\d{1,2}:\d{1,2}):\d{1,2}([^\d]*)$/, '$1$2');
    var result = d + ' ' + t;
    return result;

You can try it here:

\u200E is some formatting character that I've seen on some IE version (it's unicode left-to-right mark).

I assume that if the formatted time contains something like "XX:XX:XX" then it must be time with seconds and I remove the last part, if I don't find this pattern, nothing is changed. Pretty safe, but there is a risk of leaving seconds in some weird circumstances.

I just hope that there is no locale that would change the order of formatted time parts (e.g. make it ss:mm:hh). This left-to-right mark is making me a bit nervous about that though, that is why I don't remove the right-to-left mark (\u202E) - I prefer to not find a match in this case and leave the time formatted with seconds in such case.

Alphabet range in Python

>>> import string
>>> string.ascii_lowercase

If you really need a list:

>>> list(string.ascii_lowercase)
['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']

And to do it with range

>>> list(map(chr, range(97, 123))) #or list(map(chr, range(ord('a'), ord('z')+1)))
['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']

Other helpful string module features:

>>> help(string) # on Python 3
    ascii_letters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
    ascii_lowercase = 'abcdefghijklmnopqrstuvwxyz'
    digits = '0123456789'
    hexdigits = '0123456789abcdefABCDEF'
    octdigits = '01234567'
    printable = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}~ \t\n\r\x0b\x0c'
    punctuation = '!"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}~'
    whitespace = ' \t\n\r\x0b\x0c'

Read input stream twice

For splitting an InputStream in two, while avoiding to load all data in memory, and then process them independently:

  1. Create a couple of OutputStream, precisely: PipedOutputStream
  2. Connect each PipedOutputStream with a PipedInputStream, these PipedInputStream are the returned InputStream.
  3. Connect the sourcing InputStream with just created OutputStream. So, everything read it from the sourcing InputStream, would be written in both OutputStream. There is not need to implement that, because it is done already in TeeInputStream (
  4. Within a separated thread read the whole sourcing inputStream, and implicitly the input data is transferred to the target inputStreams.

    public static final List<InputStream> splitInputStream(InputStream input) 
        throws IOException 
        PipedOutputStream pipedOut01 = new PipedOutputStream();
        PipedOutputStream pipedOut02 = new PipedOutputStream();
        List<InputStream> inputStreamList = new ArrayList<>();
        inputStreamList.add(new PipedInputStream(pipedOut01));
        inputStreamList.add(new PipedInputStream(pipedOut02));
        TeeOutputStream tout = new TeeOutputStream(pipedOut01, pipedOut02);
        TeeInputStream tin = new TeeInputStream(input, tout, true);
        return Collections.unmodifiableList(inputStreamList);

Be aware to close the inputStreams after being consumed, and close the thread that runs: TeeInputStream.readAllBytes()

In case, you need to split it into multiple InputStream, instead of just two. Replace in the previous fragment of code the class TeeOutputStream for your own implementation, which would encapsulate a List<OutputStream> and override the OutputStream interface:

public final class TeeListOutputStream extends OutputStream {
    private final List<? extends OutputStream> branchList;

    public TeeListOutputStream(final List<? extends OutputStream> branchList) {
        this.branchList = branchList;

    public synchronized void write(final int b) throws IOException {
        for (OutputStream branch : branchList) {

    public void flush() throws IOException {
        for (OutputStream branch : branchList) {

    public void close() throws IOException {
        for (OutputStream branch : branchList) {

Select value from list of tuples where condition

One solution to this would be a list comprehension, with pattern matching inside your tuple:

>>> mylist = [(25,7),(26,9),(55,10)]
>>> [age for (age,person_id) in mylist if person_id == 10]

Another way would be using map and filter:

>>> map( lambda (age,_): age, filter( lambda (_,person_id): person_id == 10, mylist) )

PHP: How can I determine if a variable has a value that is between two distinct constant values?

if (($value > 1 && $value < 10) || ($value > 20 && $value < 40))

Send email by using codeigniter library via localhost

Please check my working code.

function sendMail()
    $config = Array(
  'protocol' => 'smtp',
  'smtp_host' => 'ssl://',
  'smtp_port' => 465,
  'smtp_user' => '[email protected]', // change it to yours
  'smtp_pass' => 'xxx', // change it to yours
  'mailtype' => 'html',
  'charset' => 'iso-8859-1',
  'wordwrap' => TRUE

        $message = '';
        $this->load->library('email', $config);
      $this->email->from('[email protected]'); // change it to yours
      $this->email->to('[email protected]');// change it to yours
      $this->email->subject('Resume from JobsBuddy for your Job posting');
      echo 'Email sent.';


How to append to a file in Node?

When you want to write in a log file, i.e. appending data to the end of a file, never use appendFile. appendFile opens a file handle for each piece of data you add to your file, after a while you get a beautiful EMFILE error.

I can add that appendFile is not easier to use than a WriteStream.

Example with appendFile:

console.log(new Date().toISOString());
[...Array(10000)].forEach( function (item,index) {
    fs.appendFile("append.txt", index+ "\n", function (err) {
        if (err) console.log(err);
console.log(new Date().toISOString());

Up to 8000 on my computer, you can append data to the file, then you obtain this:

{ Error: EMFILE: too many open files, open 'C:\mypath\append.txt'
    at Error (native)
  errno: -4066,
  code: 'EMFILE',
  syscall: 'open',
  path: 'C:\\mypath\\append.txt' }

Moreover, appendFile will write when it is enabled, so your logs will not be written by timestamp. You can test with example, set 1000 in place of 100000, order will be random, depends on access to file.

If you want to append to a file, you must use a writable stream like this:

var stream = fs.createWriteStream("append.txt", {flags:'a'});
console.log(new Date().toISOString());
[...Array(10000)].forEach( function (item,index) {
    stream.write(index + "\n");
console.log(new Date().toISOString());

You end it when you want. You are not even required to use stream.end(), default option is AutoClose:true, so your file will end when your process ends and you avoid opening too many files.

Call of overloaded function is ambiguous

replace p.setval(0); with the following.

const unsigned int param = 0;

That way it knows for sure which type the constant 0 is.

Take n rows from a spark dataframe and pass to toPandas()

Try it:

def showDf(df, count=None, percent=None, maxColumns=0):
    if (df == None): return
    import pandas
    from IPython.display import display
    pandas.set_option('display.encoding', 'UTF-8')
    # Pandas dataframe
    dfp = None
    # maxColumns param
    if (maxColumns >= 0):
        if (maxColumns == 0): maxColumns = len(df.columns)
        pandas.set_option('display.max_columns', maxColumns)
    # count param
    if (count == None and percent == None): count = 10 # Default count
    if (count != None):
        count = int(count)
        if (count == 0): count = df.count()
        pandas.set_option('display.max_rows', count)
        dfp = pandas.DataFrame(df.head(count), columns=df.columns)
    # percent param
    elif (percent != None):
        percent = float(percent)
        if (percent >=0.0 and percent <= 1.0):
            import datetime
            now =
            seed = long(now.strftime("%H%M%S"))
            dfs = df.sample(False, percent, seed)
            count = df.count()
            pandas.set_option('display.max_rows', count)
            dfp = dfs.toPandas()    

Examples of usages are:

# Shows the ten first rows of the Spark dataframe
showDf(df, 10)
showDf(df, count=10)

# Shows a random sample which represents 15% of the Spark dataframe
showDf(df, percent=0.15) 

ContractFilter mismatch at the EndpointDispatcher exception

I had this problem as well. It turned out it was caused by the contract serializer on server's end. It couldn't return my data contract object because some of its datamembers were readonly properties.

Make sure your objects have setters for properties meant to be serialized.

Is it possible that one domain name has multiple corresponding IP addresses?

Yes this is possible, however not convenient as Jens said. Using Next generation load balancers like Alteon, which Uses a proprietary protocol called DSSP(Distributed site state Protocol) which performs regular site checks to make sure that the service is available both Locally or Globally i.e different geographical areas. You need to however in your Master DNS to delegate the URL or Service to the device by configuring it as an Authoritative Name Server for that IP or Service. By doing this, the device answers DNS queries where it will resolve the IP that has a service by Round-Robin or is not congested according to how you have chosen from several metrics.

What does double question mark (??) operator mean in PHP

$myVar = $someVar ?? 42;

Is equivalent to :

$myVar = isset($someVar) ? $someVar : 42;

For constants, the behaviour is the same when using a constant that already exists :

define("FOO", "bar");
define("BAR", null);

$MyVar = FOO ?? "42";
$MyVar2 = BAR ?? "42";

echo $MyVar . PHP_EOL;  // bar
echo $MyVar2 . PHP_EOL; // 42

However, for constants that don't exist, this is different :

$MyVar3 = IDONTEXIST ?? "42"; // Raises a warning
echo $MyVar3 . PHP_EOL;       // IDONTEXIST

Warning: Use of undefined constant IDONTEXIST - assumed 'IDONTEXIST' (this will throw an Error in a future version of PHP)

Php will convert the non-existing constant to a string.

You can use constant("ConstantName") that returns the value of the constant or null if the constant doesn't exist, but it will still raise a warning. You can prepended the function with the error control operator @ to ignore the warning message :

$myVar = @constant("IDONTEXIST") ?? "42"; // No warning displayed anymore
echo $myVar . PHP_EOL; // 42

Check if a String contains a special character

You can use the following code to detect special character from string.

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class DetectSpecial{ 
public int getSpecialCharacterCount(String s) {
     if (s == null || s.trim().isEmpty()) {
         System.out.println("Incorrect format of string");
         return 0;
     Pattern p = Pattern.compile("[^A-Za-z0-9]");
     Matcher m = p.matcher(s);
    // boolean b = m.matches();
     boolean b = m.find();
     if (b)
        System.out.println("There is a special character in my string ");
         System.out.println("There is no special char.");
     return 0;

Background blur with CSS


Since the -moz-element() property doesn't seem to be widely supported by other browsers except to FF, there's an even easier technique to apply blurring without affecting the contents of the container. The use of pseudoelements is ideal in this case in combination with svg blur filter.

Check the demo using pseudo-element

(Demo was tested in FF v49, Chrome v53, Opera 40 - IE doesn't seem to support blur either with css or svg filter)

The only way (so far) of having a blur effect in the background without js plugins, is the use of -moz-element() property in combination with the svg blur filter. With -moz-element() you can define an element as a background image of another element. Then you apply the svg blur filter. OPTIONAL: You can utilize some jQuery for scrolling if your background is in fixed position.

See my demo here

I understand it is a quite complicated solution and limited to FF (element() applies only to Mozilla at the moment with -moz-element() property) but at least there's been some effort in the past to implement in webkit browsers and hopefully it will be implemented in the future.

How can I create basic timestamps or dates? (Python 3.4)

>>> import time
>>> print(time.strftime('%a %H:%M:%S'))
Mon 06:23:14

Set Colorbar Range in matplotlib

Using figure environment and .set_clim()

Could be easier and safer this alternative if you have multiple plots:

import matplotlib as m
import matplotlib.pyplot as plt
import numpy as np

cdict = {
  'red'  :  ( (0.0, 0.25, .25), (0.02, .59, .59), (1., 1., 1.)),
  'green':  ( (0.0, 0.0, 0.0), (0.02, .45, .45), (1., .97, .97)),
  'blue' :  ( (0.0, 1.0, 1.0), (0.02, .75, .75), (1., 0.45, 0.45))

cm = m.colors.LinearSegmentedColormap('my_colormap', cdict, 1024)

x = np.arange(0, 10, .1)
y = np.arange(0, 10, .1)
X, Y = np.meshgrid(x,y)

data = 2*( np.sin(X) + np.sin(3*Y) )
data1 = np.clip(data,0,6)
data2 = np.clip(data,-6,0)
vmin = np.min(np.array([data,data1,data2]))
vmax = np.max(np.array([data,data1,data2]))

fig = plt.figure()
ax = fig.add_subplot(131)
mesh = ax.pcolormesh(data, cmap = cm)
ax1 = fig.add_subplot(132)
mesh1 = ax1.pcolormesh(data1, cmap = cm)
ax2 = fig.add_subplot(133)
mesh2 = ax2.pcolormesh(data2, cmap = cm)
# Visualizing colorbar part -start
# Visualizing colorbar part -end

enter image description here

A single colorbar

The best alternative is then to use a single color bar for the entire plot. There are different ways to do that, this tutorial is very useful for understanding the best option. I prefer this solution that you can simply copy and paste instead of the previous visualizing colorbar part of the code.

fig.subplots_adjust(bottom=0.1, top=0.9, left=0.1, right=0.8,
                    wspace=0.4, hspace=0.1)
cb_ax = fig.add_axes([0.83, 0.1, 0.02, 0.8])
cbar = fig.colorbar(mesh, cax=cb_ax)

enter image description here


I would suggest using pcolormesh instead of pcolor because it is faster (more infos here ).

How do I specify different Layouts in the ASP.NET MVC 3 razor ViewStart file?

This method is the simplest way for beginners to control Layouts rendering in your ASP.NET MVC application. We can identify the controller and render the Layouts as par controller, to do this we can write our code in _ViewStart file in the root directory of the Views folder. Following is an example shows how it can be done.

    var controller = HttpContext.Current.Request.RequestContext.RouteData.Values["Controller"].ToString();
    string cLayout = "";

    if (controller == "Webmaster")
        cLayout = "~/Views/Shared/_WebmasterLayout.cshtml";
        cLayout = "~/Views/Shared/_Layout.cshtml";

    Layout = cLayout;

Read Complete Article here "How to Render different Layout in ASP.NET MVC"

Remove rows with all or some NAs (missing values) in data.frame

This will return the rows that have at least ONE non-NA value.


This will return the rows that have at least TWO non-NA value.


Redirect to specified URL on PHP script completion?

ob_start(); // ensures anything dumped out will be caught

// do stuff here
$url = ''; // this can be set based on whatever

// clear out the output buffer
while (ob_get_status()) 

// no redirect
header( "Location: $url" );

Case Insensitive String comp in C

Additional pitfalls to watch out for when doing case insensitive compares:

Comparing as lower or as upper case? (common enough issue)

Both below will return 0 with strcicmpL("A", "a") and strcicmpU("A", "a").
Yet strcicmpL("A", "_") and strcicmpU("A", "_") can return different signed results as '_' is often between the upper and lower case letters.

This affects the sort order when used with qsort(..., ..., ..., strcicmp). Non-standard library C functions like the commonly available stricmp() or strcasecmp() tend to be well defined and favor comparing via lowercase. Yet variations exist.

int strcicmpL(char const *a, char const *b) {
  while (*b) {
    int d = tolower(*a) - tolower(*b);
    if (d) {
        return d;
  return tolower(*a);

int strcicmpU(char const *a, char const *b) {
  while (*b) {
    int d = toupper(*a) - toupper(*b);
    if (d) {
        return d;
  return toupper(*a);

char can have a negative value. (not rare)

touppper(int) and tolower(int) are specified for unsigned char values and the negative EOF. Further, strcmp() returns results as if each char was converted to unsigned char, regardless if char is signed or unsigned.

tolower(*a); // Potential UB
tolower((unsigned char) *a); // Correct (Almost - see following)

char can have a negative value and not 2's complement. (rare)

The above does not handle -0 nor other negative values properly as the bit pattern should be interpreted as unsigned char. To properly handle all integer encodings, change the pointer type first.

// tolower((unsigned char) *a);
tolower(*(const unsigned char *)a); // Correct

Locale (less common)

Although character sets using ASCII code (0-127) are ubiquitous, the remainder codes tend to have locale specific issues. So strcasecmp("\xE4", "a") might return a 0 on one system and non-zero on another.

Unicode (the way of the future)

If a solution needs to handle more than ASCII consider a unicode_strcicmp(). As C lib does not provide such a function, a pre-coded function from some alternate library is recommended. Writing your own unicode_strcicmp() is a daunting task.

Do all letters map one lower to one upper? (pedantic)

[A-Z] maps one-to-one with [a-z], yet various locales map various lower case chracters to one upper and visa-versa. Further, some uppercase characters may lack a lower case equivalent and again, visa-versa.

This obliges code to covert through both tolower() and tolower().

int d = tolower(toupper(*a)) - tolower(toupper(*b));

Again, potential different results for sorting if code did tolower(toupper(*a)) vs. toupper(tolower(*a)).


@B. Nadolson recommends to avoid rolling your own strcicmp() and this is reasonable, except when code needs high equivalent portable functionality.

Below is an approach that even performed faster than some system provided functions. It does a single compare per loop rather than two by using 2 different tables that differ with '\0'. Your results may vary.

static unsigned char low1[UCHAR_MAX + 1] = {
  0, 1, 2, 3, ...
  '@', 'a', 'b', 'c', ... 'z', `[`, ...  // @ABC... Z[...
  '`', 'a', 'b', 'c', ... 'z', `{`, ...  // `abc... z{...
static unsigned char low2[UCHAR_MAX + 1] = {
// v--- Not zero, but A which matches none in `low1[]`
  'A', 1, 2, 3, ...
  '@', 'a', 'b', 'c', ... 'z', `[`, ...
  '`', 'a', 'b', 'c', ... 'z', `{`, ...

int strcicmp_ch(char const *a, char const *b) {
  // compare using tables that differ slightly.
  while (low1[*(const unsigned char *)a] == low2[*(const unsigned char *)b]) {
  // Either strings differ or null character detected.
  // Perform subtraction using same table.
  return (low1[*(const unsigned char *)a] - low1[*(const unsigned char *)b]);

List file names based on a filename pattern and file content?

find /folder -type f -mtime -90 | grep -E "(.txt|.php|.inc|.root|.gif)" | xargs ls -l > WWWlastActivity.log

Android ListView Selector Color

The list selector drawable is a StateListDrawable — it contains reference to multiple drawables for each state the list can be, like selected, focused, pressed, disabled...

While you can retrieve the drawable using getSelector(), I don't believe you can retrieve a specific Drawable from a StateListDrawable, nor does it seem possible to programmatically retrieve the colour directly from a ColorDrawable anyway.

As for setting the colour, you need a StateListDrawable as described above. You can set this on your list using the android:listSelector attribute, defining the drawable in XML like this:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="">
  <item android:state_enabled="false" android:state_focused="true"
        android:drawable="@drawable/item_disabled" />
  <item android:state_pressed="true"
        android:drawable="@drawable/item_pressed" />
  <item android:state_focused="true"
        android:drawable="@drawable/item_focused" />

ImportError: No module named apiclient.discovery

It only worked with me when I used sudo:

sudo pip install --upgrade google-api-python-client

How to use PHP with Visual Studio

By default VS is not made to run PHP, but you can do it with extensions:

You can install an add-on with the extension manager, PHP Tools for Visual Studio.

If you want to install it inside VS, go to Tools > Extension Manager > Online Gallery > Search for PHP where you will find PHP Tools (the link above) for Visual Studio. Also you have VS.Php for Visual Studio. Both are not free.

You have also a cool PHP compiler called Phalanger: Phalanger PHP Compiler

If I'm not mistaken, the code you wrote above is JavaScript (jQuery) and not PHP.

If you want cool standalone IDE's for PHP: (Free)

MySQL: Can't create/write to file '/tmp/#sql_3c6_0.MYI' (Errcode: 2) - What does it even mean?

it's very easy, you just grant the /tmp folder as 777 permission. just type:

chmod -R 777 /tmp

Are global variables bad?

Absolutely not. Misusing them though... that is bad.

Mindlessly removing them for the sake of is just that... mindless. Unless you know the advanatages and disadvantages, it is best to steer clear and do as you have been taught/learned, but there is nothing implicitly wrong with global variables. When you understand the pros and cons better make your own decision.

Could not load file or assembly or one of its dependencies. Access is denied. The issue is random, but after it happens once, it continues

In my case it was due to the Access Protection feature of my anti-virus (McAfee). It was obviously blocking access to this file, as of such the error.

I disabled it and the solution ran. You might want to check any utility application you might have running that could be affecting access to some files.

Bootstrap-select - how to fire event on change

Simplest solution would be -


Make footer stick to bottom of page correctly

the easiest hack is to set a min-height to your page container at 400px assuming your footer come at the end. you dont even have to put css for the footer or just a width:100% assuming your footer is direct child of your <body>

Running ASP.Net on a Linux based server

dotnet is the official home of .NET on GitHub. It's a great starting point to find many .NET OSS projects from Microsoft and the community, including many that are part of the .NET Foundation.

This may be a great start to support Linux.

Automatically open default email client and pre-populate content

Try this: It will open the default mail directly.

<a href="mailto:[email protected]"><img src="ICON2.png"></a>

Reliable way to convert a file to a byte[]

Others have noted that you can use the built-in File.ReadAllBytes. The built-in method is fine, but it's worth noting that the code you post above is fragile for two reasons:

  1. Stream is IDisposable - you should place the FileStream fs = new FileStream(filename, FileMode.Open,FileAccess.Read) initialization in a using clause to ensure the file is closed. Failure to do this may mean that the stream remains open if a failure occurs, which will mean the file remains locked - and that can cause other problems later on.
  2. fs.Read may read fewer bytes than you request. In general, the .Read method of a Stream instance will read at least one byte, but not necessarily all bytes you ask for. You'll need to write a loop that retries reading until all bytes are read. This page explains this in more detail.

How to make a select with array contains value clause in psql


SELECT * FROM table WHERE arr @> ARRAY['s']::varchar[]

How to check whether a file is empty or not?

if you want to check csv file is empty or not .......try this

with open('file.csv','a',newline='') as f:
        if os.stat('file.csv').st_size > 0:

What are the differences between WCF and ASMX web services?

This is a very old question, but I do not feel that the benefits of ASMX have been fairly portrayed. While not terribly flexible, ASMX web services are very simple to use and understand. While WCF is more flexible, it is also more complex to stand up and configure.

ASMX web services are ready to stand up and add as a webservice reference as soon as you add the file. (assuming your project builds)

For the simple development workflow of create webservice -> run webservice -> add webservice reference, an ASMX webservice has very little that can go wrong, not much that you can misconfigure, and that is it's strength.

In response to those that assert that WCF replaces ASMX, I would reply that WCF would need to add a streamlined K.I.S.S. configuration mode in order to completely replace ASMX.

Example web.config for an ASMX webservice:

<?xml version="1.0" encoding="utf-8"?>
  <appSettings />
    <compilation targetFramework="4.5" />
    <httpRuntime targetFramework="4.5" />

http post - how to send Authorization header?

I had the same issue. This is my solution using angular documentation and firebase Token:

getService()  {

const accessToken=this.afAuth.auth.currentUser.getToken().then(res=>{
  const httpOptions = {
    headers: new HttpHeaders({
      'Content-Type':  'application/json',
      'Authorization': res
  return this.http.get('Url',httpOptions)
    .subscribe(res => console.log(res));
}); }}

How to change the buttons text using javascript

innerText is the current correct answer for this. The other answers are outdated and incorrect.

document.getElementById('ShowButton').innerText = 'Show filter';

innerHTML also works, and can be used to insert HTML.

Moving x-axis to the top of a plot in matplotlib



to place the tick marks at the top of the image. The command

ax.set_xlabel('X LABEL')    

affects the label, not the tick marks.

import matplotlib.pyplot as plt
import numpy as np
column_labels = list('ABCD')
row_labels = list('WXYZ')
data = np.random.rand(4, 4)
fig, ax = plt.subplots()
heatmap = ax.pcolor(data,

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

# want a more natural, table-like display

ax.set_xticklabels(column_labels, minor=False)
ax.set_yticklabels(row_labels, minor=False)

enter image description here

UML diagram shapes missing on Visio 2013

If you don't find Stencils you can locate them in your install location. C:\Program Files\Microsoft Office\Office15\Visio Content\1033 for UML Sequcen Stencies you can open

Git: "Corrupt loose object"

I followed many of the other steps here; Linus' description of how to look at the git tree/objects and find what's missing was especially helpful. git-git recover corrupted blob

But in the end, for me, I had loose/corrupt tree objects caused by a partial disk failure, and tree objects are not so easily recovered/not covered by that doc.

In the end, I moved the conflicting objects/<ha>/<hash> out of the way, and used git unpack-objects with a pack file from a reasonably up to date clone. It was able to restore the missing tree objects.

Still left me with a lot of dangling blobs, which can be a side effect of unpacking previously archived stuff, and addressed in other questions here

Set session variable in laravel

php artisan make:controller SessionController --plain



namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Http\Requests;
use App\Http\Controllers\Controller;

class SessionController extends Controller {
   public function accessSessionData(Request $request) {
         echo $request->session()->get('my_name');
         echo 'No data in the session';
   public function storeSessionData(Request $request) {
      $request->session()->put('my_name','Ajay kumar');
      echo "Data has been added to session";
   public function deleteSessionData(Request $request) {
      echo "Data has been removed from session.";

And all route:


More Help: How To Set Session In Laravel?

When to use HashMap over LinkedList or ArrayList and vice-versa

Lists and Maps are different data structures. Maps are used for when you want to associate a key with a value and Lists are an ordered collection.

Map is an interface in the Java Collection Framework and a HashMap is one implementation of the Map interface. HashMap are efficient for locating a value based on a key and inserting and deleting values based on a key. The entries of a HashMap are not ordered.

ArrayList and LinkedList are an implementation of the List interface. LinkedList provides sequential access and is generally more efficient at inserting and deleting elements in the list, however, it is it less efficient at accessing elements in a list. ArrayList provides random access and is more efficient at accessing elements but is generally slower at inserting and deleting elements.

did you register the component correctly? For recursive components, make sure to provide the "name" option

i ran into this problem and below is a different solution. I were export my components as

export default {

and I imported like this:

import { MyComponent1, MyComponent2} from '@/index'

export default {
  name: 'App',
  components: {

And it gave this error.

The solution is:

Just use export { ... } don't use export default

Simpler way to create dictionary of separate variables?

I wrote the package sorcery to do this kind of magic robustly. You can write:

from sorcery import dict_of

my_dict = dict_of(foo, bar)

Your project path contains non-ASCII characters android studio

I also encountered this problem, and I have to change the folder name from Chinese to English. Pity that current gradle build tool does not support Unicode names.

MySQL - How to parse a string value to DATETIME format inside an INSERT statement?

Use MySQL's STR_TO_DATE() function to parse the string that you're attempting to insert:

INSERT INTO tblInquiry (fldInquiryReceivedDateTime) VALUES
  (STR_TO_DATE('5/15/2012 8:06:26 AM', '%c/%e/%Y %r'))

Disable beep of Linux Bash on Windows 10

Uncommenting set bell-style none in /etc/inputrc and creating a .bash_profile with setterm -blength 0 didn't stop vim from beeping.

What worked for me was creating a .vimrc file in my home directory with set visualbell.


How to initialize a two-dimensional array in Python?

t = [ [0]*10 for i in [0]*10]

for each element a new [0]*10 will be created ..

How to check undefined in Typescript

In Typescript 2 you can use Undefined type to check for undefined values. So if you declare a variable as:

let uemail : string | undefined;

Then you can check if the variable z is undefined as:

if(uemail === undefined)


How can you sort an array without mutating the original array?

Anyone who wants to do a deep copy (e.g. if your array contains objects) can use:

let arrCopy = JSON.parse(JSON.stringify(arr))

Then you can sort arrCopy without changing arr.

arrCopy.sort((obj1, obj2) => >

Please note: this can be slow for very large arrays.

Objective-C: Calling selectors with multiple arguments

Think the class should be defined as:

- (void) myTestWithSomeString:(NSString *) astring{
    NSLog(@"hi, %s", astring);

You only have a single parameter so you should only have a single :

You might want to consider using %@ in your NSLog also - it is just a good habit to get into - will then write out any object - not just strings.

HttpUtility does not exist in the current context

After following the answers above , and did

Project -> Properties -> Application -> Target Framework -> select ".Net Framework 4"

It still didn't work until I went to
Project -> Add Reference
And selected System.web. And everything worked link a charm.

HTML Display Current date

Use Date::toLocaleDateString.

new Date().toLocaleDateString()
= "9/13/2015"

You don't need to set innerHTML, just by writing

<script> document.write(new Date().toLocaleDateString()); </script>

will work.



new Date().toDateString()
= "Sun Sep 13 2015"

How to loop through all the properties of a class?

Here's another way to do it, using a LINQ lambda:


SomeObject.GetType().GetProperties().ToList().ForEach(x => Console.WriteLine($"{x.Name} = {x.GetValue(SomeObject, null)}"));


SomeObject.GetType.GetProperties.ToList.ForEach(Sub(x) Console.WriteLine($"{x.Name} = {x.GetValue(SomeObject, Nothing)}"))

How can you strip non-ASCII characters from a string? (in C#)

I believe MonsCamus meant:

parsememo = Regex.Replace(parsememo, @"[^\u0020-\u007E]", string.Empty);

How to put data containing double-quotes in string variable?

You can escape (this is how this principle is called) the double quotes by prefixing them with another double quote. You can put them in a string as follows:

Dim MyVar as string = "some text ""hello"" "

This will give the MyVar variable a value of some text "hello".

The simplest way to resize an UIImage?

Here's a Swift version of Paul Lynch's answer

func imageWithImage(image:UIImage, scaledToSize newSize:CGSize) -> UIImage{
    UIGraphicsBeginImageContextWithOptions(newSize, false, 0.0);
    image.drawInRect(CGRectMake(0, 0, newSize.width, newSize.height))
    let newImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()
    return newImage

And as an extension:

public extension UIImage {
    func copy(newSize: CGSize, retina: Bool = true) -> UIImage? {
        // In next line, pass 0 to use the current device's pixel scaling factor (and thus account for Retina resolution).
        // Pass 1 to force exact pixel size.
            /* size: */ newSize,
            /* opaque: */ false,
            /* scale: */ retina ? 0 : 1
        defer { UIGraphicsEndImageContext() }

        self.draw(in: CGRect(origin: .zero, size: newSize))
        return UIGraphicsGetImageFromCurrentImageContext()

How to use Google Translate API in my Java application?

You can use Google Translate API v2 Java. It has a core module that you can call from your Java code and also a command line interface module.

Getting Unexpected Token Export

Using ES6 syntax does not work in node, unfortunately, you have to have babel apparently to make the compiler understand syntax such as export or import.

npm install babel-cli --save

Now we need to create a .babelrc file, in the babelrc file, we’ll set babel to use the es2015 preset we installed as its preset when compiling to ES5.

At the root of our app, we’ll create a .babelrc file. $ npm install babel-preset-es2015 --save

At the root of our app, we’ll create a .babelrc file.

{  "presets": ["es2015"] }

Hope it works ... :)