Programs & Examples On #Nautilus

Nautilus is the official file manager and desktop shell for the GNOME desktop. Nautilus is is extensible via C and Python.

How do I change file permissions in Ubuntu

Add -R for recursive:

sudo chmod -R 666 /var/www

What does set -e mean in a bash script?

Script 1: without setting -e
decho "hi"
echo "hello"
This will throw error in decho and program continuous to next line

Script 2: With setting -e
set -e
decho "hi" 
echo "hello"
# Up to decho "hi" shell will process and program exit, it will not proceed further

Display current path in terminal only

If you just want to get the information of current directory, you can type:


and you don't need to use the Nautilus, or you can use a teamviewer software to remote connect to the computer, you can get everything you want.

Understanding the Linux oom-killer's logs

Memory management in Linux is a bit tricky to understand, and I can't say I fully understand it yet, but I'll try to share a little bit of my experience and knowledge.

Short answer to your question: Yes there are other stuff included than whats in the list.

What's being shown in your list is applications run in userspace. The kernel uses memory for itself and modules, on top of that it also has a lower limit of free memory that you can't go under. When you've reached that level it will try to free up resources, and when it can't do that anymore, you end up with an OOM problem.

From the last line of your list you can read that the kernel reports a total-vm usage of: 1498536kB (1,5GB), where the total-vm includes both your physical RAM and swap space. You stated you don't have any swap but the kernel seems to think otherwise since your swap space is reported to be full (Total swap = 524284kB, Free swap = 0kB) and it reports a total vmem size of 1,5GB.

Another thing that can complicate things further is memory fragmentation. You can hit the OOM killer when the kernel tries to allocate lets say 4096kB of continous memory, but there are no free ones availible.

Now that alone probably won't help you solve the actual problem. I don't know if it's normal for your program to require that amount of memory, but I would recommend to try a static code analyzer like cppcheck to check for memory leaks or file descriptor leaks. You could also try to run it through Valgrind to get a bit more information out about memory usage.

Insertion Sort vs. Selection Sort

Insertion sort do not swap things. Even though it make use of a temp variable, The point of making use of temp var is when we found a value at an index to be less compared to the value to its previous index, we shift the greater value to the place of lesser value's index which would over write things. Then we use the temp var to be substituted at the previous index. Example: 10, 20, 30, 50, 40. iteration 1: 10, 20, 30, 50, 50. [temp = 40] iteration 2: 10,20, 30, 40(temp's value), 50. So, we just insert a value at the desired position from some variable.

But When we consider selection sort, We first find the index having lower value and swap that value with the value from first index and keep on repeatedly swapping till all the indices get sorted. This is exactly same as traditional swapping of two numbers. Example: 30, 20 ,10, 40, 50. Iteration 1: 10, 20, 30, 40, 50. Here temp var is used exclusively for swapping.

How do I change the default application icon in Java? url = ClassLoader.getSystemResource("com/xyz/resources/camera.png");

May or may not require a '/' at the front of the path.

How to get value at a specific index of array In JavaScript?

You can use [];

var indexValue = Index[1];

In Bash, how do I add a string after each line in a file?

I prefer using awk. If there is only one column, use $0, else replace it with the last column.

One way,

awk '{print $0, "string to append after each line"}' file > new_file

or this,

awk '$0=$0"string to append after each line"' file > new_file

Pandas Split Dataframe into two Dataframes at a specific row

use np.split(..., axis=1):


In [255]: df = pd.DataFrame(np.random.rand(5, 6), columns=list('abcdef'))

In [256]: df
          a         b         c         d         e         f
0  0.823638  0.767999  0.460358  0.034578  0.592420  0.776803
1  0.344320  0.754412  0.274944  0.545039  0.031752  0.784564
2  0.238826  0.610893  0.861127  0.189441  0.294646  0.557034
3  0.478562  0.571750  0.116209  0.534039  0.869545  0.855520
4  0.130601  0.678583  0.157052  0.899672  0.093976  0.268974

In [257]: dfs = np.split(df, [4], axis=1)

In [258]: dfs[0]
          a         b         c         d
0  0.823638  0.767999  0.460358  0.034578
1  0.344320  0.754412  0.274944  0.545039
2  0.238826  0.610893  0.861127  0.189441
3  0.478562  0.571750  0.116209  0.534039
4  0.130601  0.678583  0.157052  0.899672

In [259]: dfs[1]
          e         f
0  0.592420  0.776803
1  0.031752  0.784564
2  0.294646  0.557034
3  0.869545  0.855520
4  0.093976  0.268974

np.split() is pretty flexible - let's split an original DF into 3 DFs at columns with indexes [2,3]:

In [260]: dfs = np.split(df, [2,3], axis=1)

In [261]: dfs[0]
          a         b
0  0.823638  0.767999
1  0.344320  0.754412
2  0.238826  0.610893
3  0.478562  0.571750
4  0.130601  0.678583

In [262]: dfs[1]
0  0.460358
1  0.274944
2  0.861127
3  0.116209
4  0.157052

In [263]: dfs[2]
          d         e         f
0  0.034578  0.592420  0.776803
1  0.545039  0.031752  0.784564
2  0.189441  0.294646  0.557034
3  0.534039  0.869545  0.855520
4  0.899672  0.093976  0.268974

How do I increase memory on Tomcat 7 when running as a Windows Service?

Assuming that you've downloaded and installed Tomcat as Windows Service Installer exe file from the Tomcat homepage, then check the Apache feather icon in the systray (or when absent, run Monitor Tomcat from the start menu). Doubleclick the feather icon and go to the Java tab. There you can configure the memory.

enter image description here

Restart the service to let the changes take effect.

Barcode scanner for mobile phone for Website in form

There's a JS QrCode scanner, that works on mobile sites with a camera:

I have worked with it for one of my project and it works pretty good !

MySQL Where DateTime is greater than today

FROM customer 
WHERE joiningdate >= NOW();

Download file inside WebView

Try using download manager, which can help you download everything you want and save you time.

Check those to options:

Option 1 ->

 mWebView.setDownloadListener(new DownloadListener() {
        public void onDownloadStart(String url, String userAgent,
                String contentDisposition, String mimetype,
                long contentLength) {
 Request request = new Request(
                    request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, "download"); 
                    DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);


Option 2 ->

if(mWebview.getUrl().contains(".mp3") {
 Request request = new Request(
                request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, "download"); 
// You can change the name of the downloads, by changing "download" to everything you want, such as the mWebview title...
                DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);


Rewrite left outer join involving multiple tables from Informix to Oracle

I'm guessing that you want something like

SELECT tab1.a, tab2.b, tab3.c, tab4.d
  FROM table1 tab1 
       JOIN table2 tab2 ON (tab1.fg = tab2.fg)
       LEFT OUTER JOIN table4 tab4 ON ( =
       LEFT OUTER JOIN table3 tab3 ON (tab4.xya = tab3.xya and tab3.desc = 'XYZ')
       LEFT OUTER JOIN table5 tab5 on (tab4.kk = tab5.kk AND
                                       tab3.dd = tab5.dd)

How do I return a char array from a function?

With Boost:

boost::array<char, 10> testfunc()
    boost::array<char, 10> str;

    return str;

A normal char[10] (or any other array) can't be returned from a function.

How to import a csv file into MySQL workbench?

It seems a little tricky since it really had bothered me for a long time.

You just need to open the table (right click the "Select Rows- Limit 10000") and you will open a new window. In this new window, you will find "import icon".

Converting string to number in javascript/jQuery

You can use parseInt(string, radix) to convert string value to integer like this code below

var votevalue = parseInt($('button').data('votevalue'));


How to run a .jar in mac?

You don't need JDK to run Java based programs. JDK is for development which stands for Java Development Kit.

You need JRE which should be there in Mac.

Try: java -jar Myjar_file.jar

EDIT: According to this article, for Mac OS 10

The Java runtime is no longer installed automatically as part of the OS installation.

Then, you need to install JRE to your machine.

Getting the client IP address: REMOTE_ADDR, HTTP_X_FORWARDED_FOR, what else could be useful?

In addition to REMOTE_ADDR and HTTP_X_FORWARDED_FOR there are some other headers that can be set such as:

  • HTTP_X_FORWARDED_FOR can be comma delimited list of IPs

I found the code on the following site useful:

Animate the transition between fragments

Nurik's answer was very helpful, but I couldn't get it to work until I found this. In short, if you're using the compatibility library (eg SupportFragmentManager instead of FragmentManager), the syntax of the XML animation files will be different.

Search for value in DataGridView in a column

"MyTable".DefaultView.RowFilter = " LIKE '%" + textBox1.Text + "%'"; this.dataGridView1.DataSource = "MyTable".DefaultView;

How about the relation to the database connections and the Datatable? And how should i set the DefaultView correct?

I use this code to get the data out:

con = new System.Data.SqlServerCe.SqlCeConnection();
con.ConnectionString = "Data Source=C:\\Users\\mhadj\\Documents\\Visual Studio 2015\\Projects\\data_base_test_2\\Sample.sdf";

DataTable dt = new DataTable();

adapt = new System.Data.SqlServerCe.SqlCeDataAdapter("select * from tbl_Record", con);        
dataGridView1.DataSource = dt;

How to view user privileges using windows cmd?

Mark Russinovich wrote a terrific tool called AccessChk that lets you get this information from the command line. No installation is necessary.

For example:

accesschk.exe /accepteula -q -a SeServiceLogonRight

Returns this for me:

IIS APPPOOL\DefaultAppPool
IIS APPPOOL\Classic .NET AppPool

By contrast, whoami /priv and whoami /all were missing some entries for me, like SeServiceLogonRight.

Test if element is present using Selenium WebDriver?

Giving my snippet of code. So, the below method checks if a random web element 'Create New Application' button exists on a page or not. Note that I have used the wait period as 0 seconds.

public boolean isCreateNewApplicationButtonVisible(){
    WebDriverWait zeroWait = new WebDriverWait(driver, 0);
    ExpectedCondition<WebElement> c = ExpectedConditions.presenceOfElementLocated(By.xpath("//input[@value='Create New Application']"));
    try {
        logger.debug("Create New Application button is visible");
        return true;
    } catch (TimeoutException e) {
        logger.debug("Create New Application button is not visible");
        return false;

How to sort a list/tuple of lists/tuples by the element at a given index?

itemgetter() is somewhat faster than lambda tup: tup[1], but the increase is relatively modest (around 10 to 25 percent).

(IPython session)

>>> from operator import itemgetter
>>> from numpy.random import randint
>>> values = randint(0, 9, 30000).reshape((10000,3))
>>> tpls = [tuple(values[i,:]) for i in range(len(values))]

>>> tpls[:5]    # display sample from list
[(1, 0, 0), 
 (8, 5, 5), 
 (5, 4, 0), 
 (5, 7, 7), 
 (4, 2, 1)]

>>> sorted(tpls[:5], key=itemgetter(1))    # example sort
[(1, 0, 0), 
 (4, 2, 1), 
 (5, 4, 0), 
 (8, 5, 5), 
 (5, 7, 7)]

>>> %timeit sorted(tpls, key=itemgetter(1))
100 loops, best of 3: 4.89 ms per loop

>>> %timeit sorted(tpls, key=lambda tup: tup[1])
100 loops, best of 3: 6.39 ms per loop

>>> %timeit sorted(tpls, key=(itemgetter(1,0)))
100 loops, best of 3: 16.1 ms per loop

>>> %timeit sorted(tpls, key=lambda tup: (tup[1], tup[0]))
100 loops, best of 3: 17.1 ms per loop

Difference between float and decimal data type

This is what I found when I had this doubt.

mysql> create table numbers (a decimal(10,2), b float);
mysql> insert into numbers values (100, 100);
mysql> select @a := (a/3), @b := (b/3), @a * 3, @b * 3 from numbers \G
*************************** 1. row ***************************
  @a := (a/3): 33.333333333
  @b := (b/3): 33.333333333333
@a + @a + @a: 99.999999999000000000000000000000
@b + @b + @b: 100

The decimal did exactly what's supposed to do on this cases, it truncated the rest, thus losing the 1/3 part.

So for sums the decimal is better, but for divisions the float is better, up to some point, of course. I mean, using DECIMAL will not give you a "fail proof arithmetic" in any means.

Hope this helps.

AngularJS access scope from outside js function

Another way to do that is:

var extScope;
var app = angular.module('myApp', []);
app.controller('myController',function($scope, $http){
    extScope = $scope;
//below you do what you want to do with $scope as extScope
    extScope.test = 'Hello world';

Check if a string is a valid date using DateTime.TryParse

So this question has been answered but to me the code used is not simple enough or complete. To me this bit here is what I was looking for and possibly some other people will like this as well.

string dateString = "198101";

if (DateTime.TryParse(dateString, out DateTime Temp) == true)
     //do stuff

The output is stored in Temp and not needed afterwards, datestring is the input string to be tested.

Java 8 stream's .min() and .max(): why does this compile?

Let me explain what is happening here, because it isn't obvious!

First, Stream.max() accepts an instance of Comparator so that items in the stream can be compared against each other to find the minimum or maximum, in some optimal order that you don't need to worry too much about.

So the question is, of course, why is Integer::max accepted? After all it's not a comparator!

The answer is in the way that the new lambda functionality works in Java 8. It relies on a concept which is informally known as "single abstract method" interfaces, or "SAM" interfaces. The idea is that any interface with one abstract method can be automatically implemented by any lambda - or method reference - whose method signature is a match for the one method on the interface. So examining the Comparator interface (simple version):

public Comparator<T> {
    T compare(T o1, T o2);

If a method is looking for a Comparator<Integer>, then it's essentially looking for this signature:

int xxx(Integer o1, Integer o2);

I use "xxx" because the method name is not used for matching purposes.

Therefore, both Integer.min(int a, int b) and Integer.max(int a, int b) are close enough that autoboxing will allow this to appear as a Comparator<Integer> in a method context.

How can one change the timestamp of an old commit in Git?

Here is a convenient alias that changes both commit and author times of the last commit to a time accepted by date --date:

    cd = "!d=\"$(date -d \"$1\")\" && shift && GIT_COMMITTER_DATE=\"$d\" \
            git commit --amend --date \"$d\""

Usage: git cd <date_arg>


git cd now  # update the last commit time to current time
git cd '1 hour ago'  # set time to 1 hour ago

Edit: Here is a more-automated version which checks that the index is clean (no uncommitted changes) and reuses the last commit message, or fails otherwise (fool-proof):

    cd = "!d=\"$(date -d \"$1\")\" && shift && \
        git diff-index --cached --quiet HEAD --ignore-submodules -- && \
        GIT_COMMITTER_DATE=\"$d\" git commit --amend -C HEAD --date \"$d\"" \
        || echo >&2 "error: date change failed: index not clean!"

R: "Unary operator error" from multiline ggplot2 command

Try to consolidate the syntax in a single line. this will clear the error

How do I check if a Socket is currently connected in Java?

Assuming you have some level of control over the protocol, I'm a big fan of sending heartbeats to verify that a connection is active. It's proven to be the most fail proof method and will often give you the quickest notification when a connection has been broken.

TCP keepalives will work, but what if the remote host is suddenly powered off? TCP can take a long time to timeout. On the other hand, if you have logic in your app that expects a heartbeat reply every x seconds, the first time you don't get them you know the connection no longer works, either by a network or a server issue on the remote side.

See Do I need to heartbeat to keep a TCP connection open? for more discussion.

Get the value of a dropdown in jQuery

$('#Crd').val() will give you the selected value of the drop down element. Use this to get the selected options text.

$('#Crd option:selected').text();

Generate fixed length Strings filled with whitespaces

This simple function works for me:

public static String leftPad(String string, int length, String pad) {
      return pad.repeat(length - string.length()) + string;


String s = leftPad(myString, 10, "0");

Corrupt jar file

The problem might be that there are more than 65536 files in your JAR: Why java complains about jar files with lots of entries? The fix is described in this question's answer.

How to get a pixel's x,y coordinate color from an image?

The two previous answers demonstrate how to use Canvas and ImageData. I would like to propose an answer with runnable example and using an image processing framework, so you don't need to handle the pixel data manually.

MarvinJ provides the method image.getAlphaComponent(x,y) which simply returns the transparency value for the pixel in x,y coordinate. If this value is 0, pixel is totally transparent, values between 1 and 254 are transparency levels, finally 255 is opaque.

For demonstrating I've used the image below (300x300) with transparent background and two pixels at coordinates (0,0) and (150,150).

enter image description here

Console output:


image = new MarvinImage();_x000D_
image.load("", imageLoaded);_x000D_
function imageLoaded(){_x000D_
  console.log("(0,0): "+(image.getAlphaComponent(0,0) > 0 ? "NOT_TRANSPARENT" : "TRANSPARENT"));_x000D_
  console.log("(150,150): "+(image.getAlphaComponent(150,150) > 0 ? "NOT_TRANSPARENT" : "TRANSPARENT"));_x000D_
<script src=""></script>

configure Git to accept a particular self-signed server certificate for a particular https remote


  1. Get the self signed certificate
  2. Put it into some (e.g. ~/git-certs/cert.pem) file
  3. Set git to trust this certificate using http.sslCAInfo parameter

In more details:

Get self signed certificate of remote server

Assuming, the server URL is and you want to access it over port 443.

There are multiple options, how to get it.

Get certificate using openssl

$ openssl s_client -connect

Catch the output into a file cert.pem and delete all but part between (and including) -BEGIN CERTIFICATE- and -END CERTIFICATE-

Content of resulting file ~/git-certs/cert.pem may look like this:


Get certificate using your web browser

I use Redmine with Git repositories and I access the same URL for web UI and for git command line access. This way, I had to add exception for that domain into my web browser.

Using Firefox, I went to Options -> Advanced -> Certificates -> View Certificates -> Servers, found there the selfsigned host, selected it and using Export button I got exactly the same file, as created using openssl.

Note: I was a bit surprised, there is no name of the authority visibly mentioned. This is fine.

Having the trusted certificate in dedicated file

Previous steps shall result in having the certificate in some file. It does not matter, what file it is as long as it is visible to your git when accessing that domain. I used ~/git-certs/cert.pem

Note: If you need more trusted selfsigned certificates, put them into the same file:


This shall work (but I tested it only with single certificate).

Configure git to trust this certificate

$ git config --global http.sslCAInfo /home/javl/git-certs/cert.pem

You may also try to do that system wide, using --system instead of --global.

And test it: You shall now be able communicating with your server without resorting to:

$ git config --global http.sslVerify false #NO NEED TO USE THIS

If you already set your git to ignorance of ssl certificates, unset it:

$ git config --global --unset http.sslVerify

and you may also check, that you did it all correctly, without spelling errors:

$ git config --global --list

what should list all variables, you have set globally. (I mispelled http to htt).

Split string with string as delimiter

I've found two older scripts that use an indefinite or even a specific string to split. As an approach, these are always helpful.

@echo off
if "%~1" neq "" goto :nohelp
echo Gibt eine Ausgabe bis zur angebenen Zeichenfolge&echo(
echo %~n0 ist mit Eingabeumleitung zu nutzen
echo %~n0 "Zeichenfolge" ^<Quelldatei [^>Zieldatei]&echo(
echo    Zeichenfolge    die zu suchende Zeichenfolge wird mit FIND bestimmt
echo            ohne AusgabeUmleitung Ausgabe im CMD Fenster
exit /b
setlocal disabledelayedexpansion
set "intemp=%temp%%time::=%"
set "string=%~1"
set "stringlength=0"
:Laenge string bestimmen
for /f eol^=^

^ delims^= %%i in (' cmd /u /von /c "echo(!string!"^|find /v "" ') do set /a Stringlength += 1

:Eingabe temporär speichern
>"%intemp%" find /n /v ""

:suchen der Zeichenfolge und Zeile bestimmen und speichen
set "NRout="
for /f "tokens=*delims=" %%a in (' find "%string%"^<"%intemp%" ') do if not defined NRout (set "LineStr=%%a"
  for /f "delims=[]" %%b in ("%%a") do set "NRout=%%b"
if not defined NRout >&2 echo Zeichenfolge nicht gefunden.& set /a xcode=1 &goto :end
if %NRout% gtr 1 call :Line
call :LineStr

del "%intemp%"
exit /b %xcode%

:LineStr Suche nur jeden ersten Buchstaben des Strings in der Treffer-Zeile dann Ausgabe bis dahin
for /f eol^=^

^ delims^= %%a in ('cmd /u /von /c "echo(!String!"^|findstr .') do (
  for /f "delims=[]" %%i in (' cmd /u /von /c "echo(!LineStr!"^|find /n "%%a" ') do (
    setlocal enabledelayedexpansion
    for /f %%n in ('set /a %%i-1') do if !LineStr:^~%%n^,%stringlength%! equ !string! (
      set "Lineout=!LineStr:~0,%%n!!string!"
      exit /b
) )
exit /b 

:Line vorige Zeilen ausgeben
for /f "usebackq tokens=* delims=" %%i in ("%intemp%") do (
  for /f "tokens=1*delims=[]" %%n in ("%%i") do if %%n EQU %NRout%  exit /b
  set "Line=%%i"
  setlocal enabledelayedexpansion 
exit /b

@echo off
:: CUTwithWildcards.cmd
if "%~1" neq "" goto :nohelp
echo Gibt eine Ausgabe ohne die angebene Zeichenfolge.
echo Der Rest wird abgeschnitten.&echo(
echo %~n0 "Zeichenfolge" B n E [/i] &echo(
echo    Zeichenfolge    String zum Durchsuchen
echo    B   Zeichen Wonach am Anfang gesucht wird
echo    n   Auszulassende Zeichenanzahl
echo    E   Zeichen was das Ende der Zeichen Bestimmt
echo    /i  Case intensive
exit /b
setlocal disabledelayedexpansion
set  "Original=%~1"
set     "Begin=%~2"
set /a    Excl=%~3 ||echo Syntaxfehler.>&2 &&exit /b 1
set       "End=%~4"
if not defined end echo Syntaxfehler.>&2 &exit /b 1
set   "CaseInt=%~5"
:: end Setting Input Param
set       "out="
set      "more="
call :read Original
if errorlevel 1 echo Zeichenfolge nicht gefunden.>&2
exit /b
:read VarName B # E [/i]
for /f "delims=[]" %%a in (' cmd /u /von /c "echo  !%~1!"^|find /n %CaseInt% "%Begin%" ') do (
  if defined out exit /b 0
  for /f "delims=[]" %%b in (' cmd /u /von /c "echo !%1!"^|more +%Excl%^|find /n %CaseInt% "%End%"^|find "[%%a]" ') do (
    set "out=1"
    setlocal enabledelayedexpansion
    set "In=  !Original!"
    set "In=!In:~,%%a!"
    echo !In:^~2!
) )
if not defined out exit /b 1 
exit /b

::oneliner for CMDLine
set "Dq=""
for %i in ("*S??E*") do @set "out=1" &for /f "delims=[]" %a in ('cmd/u/c "echo  %i"^|find /n "S"') do @if defined out for /f "delims=[]" %b in ('cmd/u/c "echo %i"^|more +2^|find /n "E"^|find "[%a]"') do @if %a equ %b set "out=" & set in= "%i" &cmd /v/c echo ren "%i" !in:^~0^,%a!!Dq!)

One line if-condition-assignment

If you wish to invoke a method if some boolean is true, you can put else None to terminate the trinary.

>>> a=1
>>> print(a) if a==1 else None
>>> print(a) if a==2 else None
>>> a=2
>>> print(a) if a==2 else None
>>> print(a) if a==1 else None

SQL Server Pivot Table with multiple column aggregates

The least complicated, most straight-forward way of doing this is by simply wrapping your main query with the pivot in a common table expression, then grouping/aggregating.

    select * from  mytransactions
    pivot (sum (totalcount) for country in ([Australia], [Austria])) as pvt
    SUM(totalamount) AS totalamount,
    SUM(ISNULL(Australia, 0)) AS Australia,
    SUM(ISNULL(Austria, 0)) Austria
GROUP BY numericmonth, chardate

The ISNULL is to stop a NULL value from nullifying the sum (because NULL + any value = NULL)

Why does .json() return a promise?

Also, what helped me understand this particular scenario that you described is the Promise API documentation, specifically where it explains how the promised returned by the then method will be resolved differently depending on what the handler fn returns:

if the handler function:

  • returns a value, the promise returned by then gets resolved with the returned value as its value;
  • throws an error, the promise returned by then gets rejected with the thrown error as its value;
  • returns an already resolved promise, the promise returned by then gets resolved with that promise's value as its value;
  • returns an already rejected promise, the promise returned by then gets rejected with that promise's value as its value.
  • returns another pending promise object, the resolution/rejection of the promise returned by then will be subsequent to the resolution/rejection of the promise returned by the handler. Also, the value of the promise returned by then will be the same as the value of the promise returned by the handler.

Yes or No confirm box using jQuery

Try This... It's very simple just use confirm dialog box for alert with YES|NO.

if(confirm("Do you want to upgrade?")){ Your code }

Remove duplicates from a List<T> in C#

A simple intuitive implementation:

public static List<PointF> RemoveDuplicates(List<PointF> listPoints)
    List<PointF> result = new List<PointF>();

    for (int i = 0; i < listPoints.Count; i++)
        if (!result.Contains(listPoints[i]))

        return result;

gridview data export to excel in

The Best way is to use closedxml. Below is the link for reference

and you can simple use

    var wb = new ClosedXML.Excel.XLWorkbook();
DataTable dt = GeDataTable();//refer documentaion


Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
Response.AddHeader("content-disposition", "attachment;filename=\"FileName.xlsx\"");

using (var ms = new System.IO.MemoryStream()) {


change directory in batch file using variable

The set statement doesn't treat spaces the way you expect; your variable is really named Pathname[space] and is equal to [space]C:\Program Files.

Remove the spaces from both sides of the = sign, and put the value in double quotes:

set Pathname="C:\Program Files"

Also, if your command prompt is not open to C:\, then using cd alone can't change drives.


cd /d %Pathname%


pushd %Pathname%


Converting Milliseconds to Minutes and Seconds?

To convert time in millis directly to minutes: second format you can use this

String durationText = DateUtils.formatElapsedTime(timeInMillis / 1000));

This will return a string with time in proper formatting. It worked for me.

How can I get double quotes into a string literal?

Escape the quotes with backslashes:

printf("She said \"time flies like an arrow, but fruit flies like a banana\"."); 

There are special escape characters that you can use in string literals, and these are denoted with a leading backslash.

Set selected option of select box

I know there are several iterations of answers but now this doesn't require jquery or any other external library and can be accomplished pretty easy just with the following.

document.querySelector("#gate option[value='Gateway 2']").setAttribute('selected',true);
<select id="gate">_x000D_
    <option value='null'>- choose -</option>_x000D_
    <option value='Gateway 1'>Gateway 1</option>_x000D_
    <option value='Gateway 2'>Gateway 2</option>_x000D_

Detecting request type in PHP (GET, POST, PUT or DELETE)

It is valuable to additionally note, that PHP will populate all the $_GET parameters even when you send a proper request of other type.

Methods in above replies are completely correct, however if you want to additionaly check for GET parameters while handling POST, DELETE, PUT, etc. request, you need to check the size of $_GET array.

SQL Statement using Where clause with multiple values

SELECT PersonName, songName, status
FROM table
WHERE name IN ('Holly', 'Ryan')

If you are using parametrized Stored procedure:

  1. Pass in comma separated string
  2. Use special function to split comma separated string into table value variable
  3. Use INNER JOIN ON t.PersonName = newTable.PersonName using a table variable which contains passed in names

syntaxerror: "unexpected character after line continuation character in python" math

The backslash \ is the line continuation character the error message is talking about, and after it, only newline characters/whitespace are allowed (before the next non-whitespace continues the "interrupted" line.

print "This is a very long string that doesn't fit" + \
      "on a single line"

Outside of a string, a backslash can only appear in this way. For division, you want a slash: /.

If you want to write a verbatim backslash in a string, escape it by doubling it: "\\"

In your code, you're using it twice:

 print("Length between sides: " + str((length*length)*2.6) +
       " \ 1.5 = " +                   # inside a string; treated as literal
       str(((length*length)*2.6)\1.5)+ # outside a string, treated as line cont
                                       # character, but no newline follows -> Fail
       " Units")

selenium get current url after loading a page

Page 2 is in a new tab/window ? If it's this, use the code bellow :

try {

    String winHandleBefore = driver.getWindowHandle();

    for(String winHandle : driver.getWindowHandles()){
        String act = driver.getCurrentUrl();
    }catch(Exception e){

Regular expression for matching HH:MM time format

You can try the following

^\d{1,2}([:.]?\d{1,2})?([ ]?[a|p]m)?$

It can detect the following patterns :

4 am 
4 pm
04:30 pm 
4:30 pm
04.30 pm
4.30 pm

How to change facebook login button with my custom image

It is actually possible only using CSS, however, the image you use to replace must be the same size as the original facebook log in button. Fortunately Facebook delivers the button in different sizes.

From facebook:

size - Different sized buttons: small, medium, large, xlarge - the default is medium.

Set the login iframe opacity to 0 and show a background image in the parent div

.fb_iframe_widget iframe {
    opacity: 0;

.fb_iframe_widget {
  background-image: url(another-button.png);
  background-repeat: no-repeat; 

If you use an image that is bigger than the original facebook button, the part of the image that is outside the width and height of the original button will not be clickable.

Cannot bulk load. Operating system error code 5 (Access is denied.)

I don't think reinstalling SQL Server is going to fix this, it's just going to kill some time.

  1. Confirm that your user account has read privileges to the folder in question.
  2. Use a tool like Process Monitor to see what user is actually trying to access the file.
  3. My guess is that it is not Michael-PC\Michael that is trying to access the file, but rather the SQL Server service account. If this is the case, then you have at least three options (but probably others):

    a. Set the SQL Server service to run as you.
    b. Grant the SQL Server service account explicit access to that folder.
    c. Put the files somewhere more logical where SQL Server has access, or can be made to have access (e.g. C:\bulk\).

I suggest these things assuming that this is a contained, local workstation. There are definitely more serious security concerns around local filesystem access from SQL Server when we're talking about a production machine, of course this can still be largely mitigated by using c. above - and only giving the service account access to the folders you want it to be able to touch.

How do you format a Date/Time in TypeScript?

Here is another option for Angular (using own formatting function) - this one is for format:

YYYY-mm-dd hh:nn:ss

-you can adjust to your formats, just re-order the lines and change separators

dateAsYYYYMMDDHHNNSS(date): string {
  return date.getFullYear()
            + '-' + this.leftpad(date.getMonth() + 1, 2)
            + '-' + this.leftpad(date.getDate(), 2)
            + ' ' + this.leftpad(date.getHours(), 2)
            + ':' + this.leftpad(date.getMinutes(), 2)
            + ':' + this.leftpad(date.getSeconds(), 2);

leftpad(val, resultLength = 2, leftpadChar = '0'): string {
  return (String(leftpadChar).repeat(resultLength)
        + String(val)).slice(String(val).length);

For current time stamp use like this:

const curTime = this.dateAsYYYYMMDDHHNNSS(new Date());

Will output e.g: 2018-12-31 23:00:01

Get to UIViewController from UIView?

My solution would probably be considered kind of bogus but I had a similar situation as mayoneez (I wanted to switch views in response to a gesture in an EAGLView), and I got the EAGL's view controller this way:

EAGLViewController *vc = ((EAGLAppDelegate*)[[UIApplication sharedApplication] delegate]).viewController;

Is it possible to execute multiple _addItem calls asynchronously using Google Analytics?

From the docs:

_trackTrans() Sends both the transaction and item data to the Google Analytics server. This method should be called after _trackPageview(), and used in conjunction with the _addItem() and addTrans() methods. It should be called after items and transaction elements have been set up.

So, according to the docs, the items get sent when you call trackTrans(). Until you do, you can add items, but the transaction will not be sent.

Edit: Further reading led me here:

Where it clearly says you can start another transaction with an existing ID. When you commit it, the new items you listed will be added to that transaction.

How do I put an already-running process under nohup?

The command to separate a running job from the shell ( = makes it nohup) is disown and a basic shell-command.

From bash-manpage (man bash):

disown [-ar] [-h] [jobspec ...]

Without options, each jobspec is removed from the table of active jobs. If the -h option is given, each jobspec is not removed from the table, but is marked so that SIGHUP is not sent to the job if the shell receives a SIGHUP. If no jobspec is present, and neither the -a nor the -r option is supplied, the current job is used. If no jobspec is supplied, the -a option means to remove or mark all jobs; the -r option without a jobspec argument restricts operation to running jobs. The return value is 0 unless a jobspec does not specify a valid job.

That means, that a simple

disown -a

will remove all jobs from the job-table and makes them nohup

Fill an array with random numbers

I tried to make this as simple as possible in Java. This makes an integer array of 100 variables and fill it with integers between 0 and 10 using only three lines of code. You can easily change the bounds of the random number too!

int RandNumbers[]=new int[100];
for (int i=0;i<RandNumbers.length;i++)

MySQLi prepared statements error reporting

Each method of mysqli can fail. You should test each return value. If one fails, think about whether it makes sense to continue with an object that is not in the state you expect it to be. (Potentially not in a "safe" state, but I think that's not an issue here.)

Since only the error message for the last operation is stored per connection/statement you might lose information about what caused the error if you continue after something went wrong. You might want to use that information to let the script decide whether to try again (only a temporary issue), change something or to bail out completely (and report a bug). And it makes debugging a lot easier.

$stmt = $mysqli->prepare("INSERT INTO testtable VALUES (?,?,?)");
// prepare() can fail because of syntax errors, missing privileges, ....
if ( false===$stmt ) {
  // and since all the following operations need a valid/ready statement object
  // it doesn't make sense to go on
  // you might want to use a more sophisticated mechanism than die()
  // but's it's only an example
  die('prepare() failed: ' . htmlspecialchars($mysqli->error));

$rc = $stmt->bind_param('iii', $x, $y, $z);
// bind_param() can fail because the number of parameter doesn't match the placeholders in the statement
// or there's a type conflict(?), or ....
if ( false===$rc ) {
  // again execute() is useless if you can't bind the parameters. Bail out somehow.
  die('bind_param() failed: ' . htmlspecialchars($stmt->error));

$rc = $stmt->execute();
// execute() can fail for various reasons. And may it be as stupid as someone tripping over the network cable
// 2006 "server gone away" is always an option
if ( false===$rc ) {
  die('execute() failed: ' . htmlspecialchars($stmt->error));


Just a few notes six years later...

The mysqli extension is perfectly capable of reporting operations that result in an (mysqli) error code other than 0 via exceptions, see mysqli_driver::$report_mode.
die() is really, really crude and I wouldn't use it even for examples like this one anymore.
So please, only take away the fact that each and every (mysql) operation can fail for a number of reasons; even if the exact same thing went well a thousand times before....

how to open a jar file in Eclipse

Since the jar file 'executes' then it contains compiled java files known as .class files. You cannot import it to eclipse and modify the code. You should ask the supplier of the "demo" for the "source code". (or check the page you got the demo from for the source code)

Unless, you want to decompile the .class files and import to Eclipse. That may not be the case for starters.

Ruby: character to ascii from a string

Ruby String provides the codepoints method after 1.9.1.

str = 'hello world'
=> [104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100] 

str = "????"
=> [20320, 22909, 19990, 30028]

Change background of LinearLayout in Android

If your using a background resource and wish to change the resource out you can use setBackgroundResource() function.


A background resource in XML would look like:


How to get the current time as datetime

You can try this

func getTime() -> (hour:Int, min:Int, sec:Int) {
        let currentDateTime = NSDate()
        let calendar = NSCalendar.currentCalendar()
        let components = calendar.components([.Hour,.Minute,.Second], fromDate: currentDateTime)
        let hour = components.hour
        let min = components.minute
        let sec = components.second
        return (hour,min,sec)

Now call that method and receive the date with hour,min and second

    let currentTime = self.getTime()
    print("Hour: \(currentTime.hour) Min: \(currentTime.min) Sec: \(currentTime.sec))")

Forbidden You don't have permission to access / on this server

Found my solution thanks to Error with .htaccess and mod_rewrite
For Apache 2.4 and in all *.conf files (e.g. httpd-vhosts.conf, http.conf, httpd-autoindex.conf ..etc) use

Require all granted

instead of

Order allow,deny
Allow from all

The Order and Allow directives are deprecated in Apache 2.4.

Getting a HeadlessException: No X11 DISPLAY variable was set

I assume you're trying to tunnel into some unix box.

Make sure X11 forwarding is enabled in your PuTTY settings.

enter image description here

JPA: difference between @JoinColumn and @PrimaryKeyJoinColumn?

What happens if I promote the column to be a/the PK, too (a.k.a. identifying relationship)? As the column is now the PK, I must tag it with @Id (...).

This enhanced support of derived identifiers is actually part of the new stuff in JPA 2.0 (see the section 2.4.1 Primary Keys Corresponding to Derived Identities in the JPA 2.0 specification), JPA 1.0 doesn't allow Id on a OneToOne or ManyToOne. With JPA 1.0, you'd have to use PrimaryKeyJoinColumn and also define a Basic Id mapping for the foreign key column.

Now the question is: are @Id + @JoinColumn the same as just @PrimaryKeyJoinColumn?

You can obtain a similar result but using an Id on OneToOne or ManyToOne is much simpler and is the preferred way to map derived identifiers with JPA 2.0. PrimaryKeyJoinColumn might still be used in a JOINED inheritance strategy. Below the relevant section from the JPA 2.0 specification:

11.1.40 PrimaryKeyJoinColumn Annotation

The PrimaryKeyJoinColumn annotation specifies a primary key column that is used as a foreign key to join to another table.

The PrimaryKeyJoinColumn annotation is used to join the primary table of an entity subclass in the JOINED mapping strategy to the primary table of its superclass; it is used within a SecondaryTable annotation to join a secondary table to a primary table; and it may be used in a OneToOne mapping in which the primary key of the referencing entity is used as a foreign key to the referenced entity[108].


If no PrimaryKeyJoinColumn annotation is specified for a subclass in the JOINED mapping strategy, the foreign key columns are assumed to have the same names as the primary key columns of the primary table of the superclass.


Example: Customer and ValuedCustomer subclass

public class Customer { ... }

public class ValuedCustomer extends Customer { ... }

[108] The derived id mechanisms described in section are now to be preferred over PrimaryKeyJoinColumn for the OneToOne mapping case.

See also

This source states that using @ManyToOne and @Id works with JPA 1.x. Who's correct now?

The author is using a pre release JPA 2.0 compliant version of EclipseLink (version 2.0.0-M7 at the time of the article) to write an article about JPA 1.0(!). This article is misleading, the author is using something that is NOT part of JPA 1.0.

For the record, support of Id on OneToOne and ManyToOne has been added in EclipseLink 1.1 (see this message from James Sutherland, EclipseLink comitter and main contributor of the Java Persistence wiki book). But let me insist, this is NOT part of JPA 1.0.

Finding the number of non-blank columns in an Excel sheet using VBA

Result is shown in the following code as column number (8,9 etc.):

Dim lastColumn As Long
lastColumn = Sheet1.Cells(1, Columns.Count).End(xlToLeft).Column
MsgBox lastColumn

Result is shown in the following code as letter (H,I etc.):

Dim lastColumn As Long
lastColumn = Sheet1.Cells(1, Columns.Count).End(xlToLeft).Column
MsgBox Split(Sheet1.Cells(1, lastColumn).Address, "$")(1)

How to hide reference counts in VS2013?

In VSCode for Mac (0.10.6) I opened "Preferences -> User Settings" and placed the following code in the settings.json file

enter image description here

"editor.referenceInfos": false

enter image description here

User and Workspace Settings

How to return a dictionary | Python

def query(id):
    for line in file:
        table = line.split(";")
        if id == int(table[0]):
             yield table

id = int(input("Enter the ID of the user: "))
for id_, name, city in query(id):
  print("ID: " + id_)
  print("Name: " + name)
  print("City: " + city)

Using yield..

Show and hide a View with a slide up/down animation

Easiest solution: set android:animateLayoutChanges="true" on the container holding your views.

To put it into some context: If you have a layout like below, all visibility changes to the views in this container will be animated automatically.

<LinearLayout android:id="@+id/container"



You can find more details about this on Animating Layout Changes - Android Developer

How to get an input text value in JavaScript

function subadd(){
subadd= parseFloat(document.forms[0][0].value) + parseFloat(document.forms[0][1].value) 

<input type="text" >+
<input type="text" >
<input type="button" value="add" onclick="subadd()">

405 method not allowed Web API

I could NOT solve this. I had CORS enabled and working as long as the POST returned void (ASP.NET 4.0 - WEBAPI 1). When I tried to return a HttpResponseMessage, I started getting the HTTP 405 response.

Based on Llad's response above, I took a look at my own references.

I had the attribute [System.Web.Mvc.HttpPost] listed above my POST method.

I changed this to use:

public HttpResponseMessage Post(object json)        
    return new HttpResponseMessage { StatusCode = HttpStatusCode.OK };

This fixed my woes. I hope this helps someone else.

For the sake of completeness, I had the following in my web.config:

        <clear />
        <add name="Access-Control-Expose-Headers " value="WWW-Authenticate"/>
        <add name="Access-Control-Allow-Origin" value="*" />
        <add name="Access-Control-Allow-Methods" value="GET, POST, OPTIONS, PUT, PATCH, DELETE" />
        <add name="Access-Control-Allow-Headers" value="accept, authorization, Content-Type" />
        <remove name="X-Powered-By" />

Pandas: Setting no. of max rows

As @hanleyhansen noted in a comment, as of version 0.18.1, the display.height option is deprecated, and says "use display.max_rows instead". So you just have to configure it like this:

pd.set_option('display.max_rows', 500)

See the Release Notes — pandas 0.18.1 documentation:

Deprecated display.height, display.width is now only a formatting option does not control triggering of summary, similar to < 0.11.0.

Parse a URI String into Name-Value Collection

Just an update to the Java 8 version

public Map<String, List<String>> splitQuery(URL url) {
    if (Strings.isNullOrEmpty(url.getQuery())) {
        return Collections.emptyMap();
            .collect(Collectors.groupingBy(SimpleImmutableEntry::getKey, LinkedHashMap::new, **Collectors**.mapping(Map.Entry::getValue, **Collectors**.toList())));

mapping and toList() methods have to be used with Collectors which was not mentioned in the top answer. Otherwise it would throw compilation error in IDE

How do a send an HTTPS request through a proxy in Java?

Try the Apache Commons HttpClient library instead of trying to roll your own:

From their sample code:

  HttpClient httpclient = new HttpClient();
  httpclient.getHostConfiguration().setProxy("myproxyhost", 8080);

  /* Optional if authentication is required.
  httpclient.getState().setProxyCredentials("my-proxy-realm", " myproxyhost",
   new UsernamePasswordCredentials("my-proxy-username", "my-proxy-password"));

  PostMethod post = new PostMethod("https://someurl");
  NameValuePair[] data = {
     new NameValuePair("user", "joe"),
     new NameValuePair("password", "bloggs")
  // execute method and handle any error responses.
  // ...
  InputStream in = post.getResponseBodyAsStream();
  // handle response.

  /* Example for a GET reqeust
  GetMethod httpget = new GetMethod("https://someurl");
  try { 
  } finally {

Create an array of integers property in Objective-C

This should work:

@interface MyClass
    int _doubleDigits[10]; 

@property(readonly) int *doubleDigits;


@implementation MyClass

- (int *)doubleDigits
    return _doubleDigits;


Where can I read the Console output in Visual Studio 2015

in the "Ouput Window". you can usually do CTRL-ALT-O to make it visible. Or through menus using View->Output.

Subset a dataframe by multiple factor levels

Here's another:

data[data$Code == "A" | data$Code == "B", ]

It's also worth mentioning that the subsetting factor doesn't have to be part of the data frame if it matches the data frame rows in length and order. In this case we made our data frame from this factor anyway. So,

data[Code == "A" | Code == "B", ]

also works, which is one of the really useful things about R.

Auto Scale TextView Text to Fit within Bounds

Extend TextView and override onDraw with the code below. It will keep text aspect ratio but size it to fill the space. You could easily modify code to stretch if necessary.

  protected void onDraw(@NonNull Canvas canvas) {
    TextPaint textPaint = getPaint();
    textPaint.drawableState = getDrawableState();

    String text = getText().toString();
    float desiredWidth = getMeasuredWidth() - getPaddingLeft() - getPaddingRight() - 2;
    float desiredHeight = getMeasuredHeight() - getPaddingTop() - getPaddingBottom() - 2;
    float textSize = textPaint.getTextSize();

    for (int i = 0; i < 10; i++) {
      textPaint.getTextBounds(text, 0, text.length(), rect);
      float width = rect.width();
      float height = rect.height();

      float deltaWidth = width - desiredWidth;
      float deltaHeight = height - desiredHeight;

      boolean fitsWidth = deltaWidth <= 0;
      boolean fitsHeight = deltaHeight <= 0;

      if ((fitsWidth && Math.abs(deltaHeight) < 1.0)
          || (fitsHeight && Math.abs(deltaWidth) < 1.0)) {
        // close enough

      float adjustX = desiredWidth / width;
      float adjustY = desiredHeight / height;

      textSize = textSize * (adjustY < adjustX ? adjustY : adjustX);

      // adjust text size
    float x = desiredWidth / 2f;
    float y = desiredHeight / 2f - - rect.height() / 2f;
    canvas.drawText(text, x, y, textPaint);

IDENTITY_INSERT is set to OFF - How to turn it ON?

The Reference:

My table is named Genre with the 3 columns of Id, Name and SortOrder

The code that I used is as:


INSERT INTO Genre(Id, Name, SortOrder)VALUES (12,'Moody Blues', 20) 

Is it possible to capture a Ctrl+C signal and run a cleanup function, in a "defer" fashion?

This is another version which work in case you have some tasks to cleanup. Code will leave clean up process in their method.

package main

import (


func main() {


    //do main thread

    println("wait for finish")
    fmt.Print("clean up done, can exit safely")


func doSomething1() (error, chan bool) {
    //do something
    done:=make(chan bool)
    c := make(chan os.Signal, 2)
    signal.Notify(c, os.Interrupt, syscall.SIGTERM)
    go func() {
        //cleanup of something1
    return nil,done

func doSomething2() (error, chan bool) {
    //do something
    done:=make(chan bool)
    c := make(chan os.Signal, 2)
    signal.Notify(c, os.Interrupt, syscall.SIGTERM)
    go func() {
        //cleanup of something2
    return nil,done

in case you need to clean main function you need to capture signal in main thread using go func() as well.

How to round 0.745 to 0.75 using BigDecimal.ROUND_HALF_UP?

This will maybe give you a hint on what went wrong.

import java.math.BigDecimal;

public class Main {
    public static void main(String[] args) {
        BigDecimal bdTest = new BigDecimal(0.745);
        BigDecimal bdTest1 = new BigDecimal("0.745");
        bdTest = bdTest.setScale(2, BigDecimal.ROUND_HALF_UP);
        bdTest1 = bdTest1.setScale(2, BigDecimal.ROUND_HALF_UP);
        System.out.println("bdTest:" + bdTest); // prints "bdTest:0.74"
        System.out.println("bdTest1:" + bdTest1); // prints "bdTest:0.75"

The problem is, that your input (a double x=0.745;) can not represent 0.745 exactly. It actually saves a value slightly lower. For BigDecimals, this is already below 0.745, so it rounds down...

Try not to use the BigDecimal(double/float) constructors.

Mysql database sync between two databases

SymmetricDS is the answer. It supports multiple subscribers with one direction or bi-directional asynchronous data replication. It uses web and database technologies to replicate tables between relational databases, in near real time if desired.

Comprehensive and robust Java API to suit your needs.

How can I mimic the bottom sheet from the Maps app?

I wrote my own library to achieve the intended behaviour in ios Maps app. It is a protocol oriented solution. So you don't need to inherit any base class instead create a sheet controller and configure as you wish. It also supports inner navigation/presentation with or without UINavigationController.

See below link for more details.

ubottom sheet

Truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all()

I encountered the same error and got stalled with a pyspark dataframe for few days, I was able to resolve it successfully by filling na values with 0 since I was comparing integer values from 2 fields.

svn cleanup: sqlite: database disk image is malformed

During app development I found that the messages come from the frequent and massive INSERT and UPDATE operations. Make sure to INSERT and UPDATE multiple rows or data in one single operation.

var updateStatementString : String! = ""

for item in cardids {

let newstring = "UPDATE "+TABLE_NAME+" SET pendingImages = '\(pendingImage)\' WHERE cardId = '\(item)\';"


        let results = dbManager.sharedInstance.update(updateStatementString: updateStatementString)

        return Int64(results)

Why does JPA have a @Transient annotation?

Java's transient keyword is used to denote that a field is not to be serialized, whereas JPA's @Transient annotation is used to indicate that a field is not to be persisted in the database, i.e. their semantics are different.

Explanation of JSONB introduced by PostgreSQL

Regarding the differences between json and jsonb datatypes, it worth mentioning the official explanation:

PostgreSQL offers two types for storing JSON data: json and jsonb. To implement efficient query mechanisms for these data types, PostgreSQL also provides the jsonpath data type described in Section 8.14.6.

The json and jsonb data types accept almost identical sets of values as input. The major practical difference is one of efficiency. The json data type stores an exact copy of the input text, which processing functions must reparse on each execution; while jsonb data is stored in a decomposed binary format that makes it slightly slower to input due to added conversion overhead, but significantly faster to process, since no reparsing is needed. jsonb also supports indexing, which can be a significant advantage.

Because the json type stores an exact copy of the input text, it will preserve semantically-insignificant white space between tokens, as well as the order of keys within JSON objects. Also, if a JSON object within the value contains the same key more than once, all the key/value pairs are kept. (The processing functions consider the last value as the operative one.) By contrast, jsonb does not preserve white space, does not preserve the order of object keys, and does not keep duplicate object keys. If duplicate keys are specified in the input, only the last value is kept.

In general, most applications should prefer to store JSON data as jsonb, unless there are quite specialized needs, such as legacy assumptions about ordering of object keys.

PostgreSQL allows only one character set encoding per database. It is therefore not possible for the JSON types to conform rigidly to the JSON specification unless the database encoding is UTF8. Attempts to directly include characters that cannot be represented in the database encoding will fail; conversely, characters that can be represented in the database encoding but not in UTF8 will be allowed.


Get size of all tables in database

I found this query to be easy to use & quick.

select schema_name(tab.schema_id) + '.' + as [table], 
cast(sum(spc.used_pages * 8)/1024.00 as numeric(36, 2)) as used_mb,
cast(sum(spc.total_pages * 8)/1024.00 as numeric(36, 2)) as allocated_mb
from sys.tables (nolock) tab
inner join sys.indexes (nolock) ind 
    on tab.object_id = ind.object_id
inner join sys.partitions  (nolock) part 
    on ind.object_id = part.object_id and ind.index_id = part.index_id
inner join sys.allocation_units (nolock) spc
    on part.partition_id = spc.container_id
group by schema_name(tab.schema_id) + '.' +
order by sum(spc.used_pages) desc

Powershell Active Directory - Limiting my get-aduser search to a specific OU [and sub OUs]

If I understand you correctly, you need to use -SearchBase:

Get-ADUser -SearchBase "OU=Accounts,OU=RootOU,DC=ChildDomain,DC=RootDomain,DC=com" -Filter *

Note that Get-ADUser defaults to using

 -SearchScope Subtree

so you don't need to specify it. It's this that gives you all sub-OUs (and sub-sub-OUs, etc.).

Best way to overlay an ESRI shapefile on google maps?

I would not use KML. Instead, use GeoJSON which you can natively consume in Google Maps API now. It is a newer feature that didn't exist from the original responses.

In any case, simply open the SHP file in Quantum GIS, and then you can output it in any format you like (KML, GeoJSON).

If you are using Google Maps for Work, I found a premium extension that handles loading shapefiles directly where you can just connect direct to the shapefile that you generate from ESRI. I did a search on the CMaps site and found this snippet which loaded US by state shapefile:

var cMap = new centigon.locationIntelligence.MapView();

    cMap.layerNames(["Basic Shapes"]);
    cMap.dbfKeys([['Alabama','Alaska','Arizona','Arkansas','California','Colorado','Connecticut','Delaware','District of Columbia','Florida','Georgia','Hawaii','Idaho','Illinois','Indiana','Iowa','Kansas','Kentucky','Louisiana','Maine','Maryland','Massachusetts','Michigan','Minnesota','Mississippi','Missouri','Montana','Nebraska','Nevada','New Hampshire','New Jersey','New Mexico','New York','North Carolina','North Dakota','Ohio','Oklahoma','Oregon','Pennsylvania','Rhode Island','South Carolina','South Dakota','Tennessee','Texas','Utah','Vermont','Virginia','Washington','West Virginia','Wisconsin','Wyoming']]);
    cMap.userShapeKeys([['Massachusetts','Minnesota','Montana','North Dakota','Hawaii','Idaho','Washington','Arizona','California','Colorado','Nevada','New Mexico','Oregon','Utah','Wyoming','Arkansas','Iowa','Kansas','Missouri','Nebraska','Oklahoma','South Dakota','Louisiana','Texas','Connecticut','New Hampshire','Rhode Island','Vermont','Alabama','Florida','Georgia','Mississippi','South Carolina','Illinois','Indiana','Kentucky','North Carolina','Ohio','Tennessee','Virginia','Wisconsin','West Virginia','Delaware','District of Columbia','Maryland','New Jersey','New York','Pennsylvania','Maine','Michigan','Alaska']]); 
    cMap.labels([['Massachusetts','Minnesota','Montana','North Dakota','Hawaii','Idaho','Washington','Arizona','California','Colorado','Nevada','New Mexico','Oregon','Utah','Wyoming','Arkansas','Iowa','Kansas','Missouri','Nebraska','Oklahoma','South Dakota','Louisiana','Texas','Connecticut','New Hampshire','Rhode Island','Vermont','Alabama','Florida','Georgia','Mississippi','South Carolina','Illinois','Indiana','Kentucky','North Carolina','Ohio','Tennessee','Virginia','Wisconsin','West Virginia','Delaware','District of Columbia','Maryland','New Jersey','New York','Pennsylvania','Maine','Michigan','Alaska']]); 



git pull error :error: remote ref is at but expected

I know this is old, but I have my own fix. Because I'm using source tree, this error happens because someone create a new branch. The source tree is confused about this. After I press "Refresh" button beside the "remote branch to pull" combobox, it seems that sourcetree has updated the branch list, and now I can pull successfully.

How to use adb pull command?

I don't think adb pull handles wildcards for multiple files. I ran into the same problem and did this by moving the files to a folder and then pulling the folder.

I found a link doing the same thing. Try following these steps.

How to copy selected files from Android with adb pull

MongoDB and "joins"

If you use mongoose, you can just use(assuming you're using subdocuments and population):

Profile.findById profileId
  .select 'friends'
  .exec (err, profile) ->
    if err or not profile
      handleError err, profile, res
      Status.find { profile: { $in: profile.friends } }, (err, statuses) ->
        if err
          handleErr err, statuses, res
          res.json createJSON statuses

It retrieves Statuses which belong to one of Profile (profileId) friends. Friends is array of references to other Profiles. Profile schema with friends defined:

schema = new mongoose.Schema
  # ...

  friends: [
    type: mongoose.Schema.Types.ObjectId
    ref: 'Profile'
    unique: true
    index: true

Python Remove last 3 characters of a string

What's wrong with this?

foo.replace(" ", "")[:-3].upper()

Connect to Amazon EC2 file directory using Filezilla and SFTP

Just one minor note to the well explained accepted answer of Yasitha Chinthaka:

Note: FileZilla automatically figures out which key to use. You do not need to specify the key after importing it as described above.

In my case I already had other 5 ppks from other instances that I was using in the past (with the ppk of the new instance being at the bottom of that list). I added the new ppk of my new instance, and it wouldn't let me connect to it. The error message: too many tries / attempts.

After I deleted the unused ppks, I was finally able to login to the instance.

So no, Filezilla is not that smart ;-)

How to downgrade tensorflow, multiple versions possible?

If you have anaconda, you can just install desired version and conda will automatically downgrade the current package for you.

For example:

conda install tensorflow=1.1

Difference between StringBuilder and StringBuffer

A simple program illustrating the difference between StringBuffer and StringBuilder:

 * Run this program a couple of times. We see that the StringBuilder does not
 * give us reliable results because its methods are not thread-safe as compared
 * to StringBuffer.
 * For example, the single append in StringBuffer is thread-safe, i.e.
 * only one thread can call append() at any time and would finish writing
 * back to memory one at a time. In contrast, the append() in the StringBuilder 
 * class can be called concurrently by many threads, so the final size of the 
 * StringBuilder is sometimes less than expected.
public class StringBufferVSStringBuilder {

    public static void main(String[] args) throws InterruptedException {

        int n = 10; 

        //*************************String Builder Test*******************************//
        StringBuilder sb = new StringBuilder();
        StringBuilderTest[] builderThreads = new StringBuilderTest[n];
        for (int i = 0; i < n; i++) {
            builderThreads[i] = new StringBuilderTest(sb);
        for (int i = 0; i < n; i++) {
        for (int i = 0; i < n; i++) {
        System.out.println("StringBuilderTest: Expected result is 1000; got " + sb.length());

        //*************************String Buffer Test*******************************//

        StringBuffer sb2 = new StringBuffer();
        StringBufferTest[] bufferThreads = new StringBufferTest[n];
        for (int i = 0; i < n; i++) {
            bufferThreads[i] = new StringBufferTest(sb2);
        for (int i = 0; i < n; i++) {
        for (int i = 0; i < n; i++) {
        System.out.println("StringBufferTest: Expected result is 1000; got " + sb2.length());



// Every run would attempt to append 100 "A"s to the StringBuilder.
class StringBuilderTest extends Thread {

    StringBuilder sb;

    public StringBuilderTest (StringBuilder sb) { = sb;

    public void run() {
        for (int i = 0; i < 100; i++) {


//Every run would attempt to append 100 "A"s to the StringBuffer.
class StringBufferTest extends Thread {

    StringBuffer sb2;

    public StringBufferTest (StringBuffer sb2) {
        this.sb2 = sb2;

    public void run() {
        for (int i = 0; i < 100; i++) {


Regular expression \p{L} and \p{N}

\p{L} matches a single code point in the category "letter".
\p{N} matches any kind of numeric character in any script.


If you're going to work with regular expressions a lot, I'd suggest bookmarking that site, it's very useful.

jQuery's .click - pass parameters to user function

Yes, this is an old post. Regardless, someone may find it useful. Here is another way to send parameters to event handlers.

//click handler
function add_event(event, paramA, paramB)
    //do something with your parameters
    alert(paramA ? 'paramA:' + paramA : '' + paramB ? '  paramB:' + paramB : '');

//bind handler to click event
//once you've processed some data and know your parameters, trigger a click event.
//In this case, we will send 'myfirst' and 'mysecond' as parameters
$('.leadtoscore').trigger('click', {'myfirst', 'mysecond'});

//or use variables
var a = 'first',
    b = 'second';

$('.leadtoscore').trigger('click', {a, b});
$('.leadtoscore').trigger('click', {a});

How to convert NSDate into unix timestamp iphone sdk?

If you need time stamp as a string.

time_t result = time(NULL);                
NSString *timeStampString = [@(result) stringValue];

Detect if a NumPy array contains at least one non-numeric value?

With numpy 1.3 or svn you can do this

In [1]: a = arange(10000.).reshape(100,100)

In [3]: isnan(a.max())
Out[3]: False

In [4]: a[50,50] = nan

In [5]: isnan(a.max())
Out[5]: True

In [6]: timeit isnan(a.max())
10000 loops, best of 3: 66.3 µs per loop

The treatment of nans in comparisons was not consistent in earlier versions.

How can I get a list of all values in select box?

It looks like placing the click event directly on the button is causing the problem. For some reason it can't find the function. Not sure why...

If you attach the event handler in the javascript, it does work however.

See it here:

<button id="display-text" type="button">Display text of all options</button>

document.getElementById('display-text').onclick = function () {
    var x = document.getElementById("mySelect");
    var txt = "All options: ";
    var i;
    for (i = 0; i < x.length; i++) {
        txt = txt + "\n" + x.options[i].value;

__init__() missing 1 required positional argument

Your constructor is expecting one parameter (data). You're not passing it in the call. I guess you wanted to initialise a field in the object. That would look like this:

class DHT:
    def __init__(self): = {}['one'] = '1'['two'] = '2'['three'] = '3'
    def showData(self):

if __name__ == '__main__':

Or even just:

class DHT:
    def __init__(self): = {'one': '1', 'two': '2', 'three': '3'}
    def showData(self):

Why am I getting "undefined reference to sqrt" error even though I include math.h header?

The math library must be linked in when building the executable. How to do this varies by environment, but in Linux/Unix, just add -lm to the command:

gcc test.c -o test -lm

The math library is named, and the -l command option assumes a lib prefix and .a or .so suffix.

C# DataTable.Select() - How do I format the filter criteria to include null?

Try out Following:

DataRow rows = DataTable.Select("[Name]<>'n/a'")

For Null check in This:

DataRow rows =  DataTable.Select("[Name] <> 'n/a' OR [Name] is NULL" )

How do I find the width & height of a terminal window?

To do this in Windows CLI environment, the best way I can find is to use the mode command and parse the output.

function getTerminalSizeOnWindows() {
  $output = array();
  $size = array('width'=>0,'height'=>0);
  foreach($output as $line) {
    $matches = array();
    $w = preg_match('/^\s*columns\:?\s*(\d+)\s*$/i',$line,$matches);
    if($w) {
      $size['width'] = intval($matches[1]);
    } else {
      $h = preg_match('/^\s*lines\:?\s*(\d+)\s*$/i',$line,$matches);
      if($h) {
        $size['height'] = intval($matches[1]);
    if($size['width'] AND $size['height']) {
  return $size;

I hope it's useful!

NOTE: The height returned is the number of lines in the buffer, it is not the number of lines that are visible within the window. Any better options out there?

Fastest way to find second (third...) highest/lowest value in vector or column

topn = function(vector, n){
  for (i in 1:n){
    biggest=match(max(vector), vector)
  mat=cbind(maxs, ind)

this function will return a matrix with the top n values and their indices. hope it helps VDevi-Chou

Javascript: Fetch DELETE and PUT requests

Here is a fetch POST example. You can do the same for DELETE.

function createNewProfile(profile) {
    const formData = new FormData();
    formData.append('first_name', profile.firstName);
    formData.append('last_name', profile.lastName);

    return fetch('', {
        method: 'POST',
        body: formData
    }).then(response => response.json())

   .then((json) => {
       // handle success
   .catch(error => error);

How many threads is too many?

If your threads are performing any kind of resource-intensive work (CPU/Disk) then you'll rarely see benefits beyond one or two, and too many will kill performance very quickly.

The 'best-case' is that your later threads will stall while the first ones complete, or some will have low-overhead blocks on resources with low contention. Worst-case is that you start thrashing the cache/disk/network and your overall throughput drops through the floor.

A good solution is to place requests in a pool that are then dispatched to worker threads from a thread-pool (and yes, avoiding continuous thread creation/destruction is a great first step).

The number of active threads in this pool can then be tweaked and scaled based on the findings of your profiling, the hardware you are running on, and other things that may be occurring on the machine.

How to get video duration, dimension and size in PHP? download getid3 zip and than only getid3 named folder copy paste in project folder and use it as below show...

        $getID3 = new getID3();
        $filename="/fire/My Documents/video/ferrari1.mpg";
        $fileinfo = $getID3->analyze($filename);


        echo $fileinfo['video']['resolution_x']. 'x'. $fileinfo['video']['resolution_y'];
        echo '<pre>';print_r($fileinfo);echo '</pre>';

How to add parameters into a WebRequest?

If these are the parameters of url-string then you need to add them through '?' and '&' chars, for example

If these are the parameters of POST request, then you need to create POST data and write it to request stream. Here is sample method:

private static string doRequestWithBytesPostData(string requestUri, string method, byte[] postData,
                                        CookieContainer cookieContainer,
                                        string userAgent, string acceptHeaderString,
                                        string referer,
                                        string contentType, out string responseUri)
            var result = "";
            if (!string.IsNullOrEmpty(requestUri))
                var request = WebRequest.Create(requestUri) as HttpWebRequest;
                if (request != null)
                    request.KeepAlive = true;
                    var cachePolicy = new RequestCachePolicy(RequestCacheLevel.BypassCache);
                    request.CachePolicy = cachePolicy;
                    request.Expect = null;
                    if (!string.IsNullOrEmpty(method))
                        request.Method = method;
                    if (!string.IsNullOrEmpty(acceptHeaderString))
                        request.Accept = acceptHeaderString;
                    if (!string.IsNullOrEmpty(referer))
                        request.Referer = referer;
                    if (!string.IsNullOrEmpty(contentType))
                        request.ContentType = contentType;
                    if (!string.IsNullOrEmpty(userAgent))
                        request.UserAgent = userAgent;
                    if (cookieContainer != null)
                        request.CookieContainer = cookieContainer;

                    request.Timeout = Constants.RequestTimeOut;

                    if (request.Method == "POST")
                        if (postData != null)
                            request.ContentLength = postData.Length;
                            using (var dataStream = request.GetRequestStream())
                                dataStream.Write(postData, 0, postData.Length);

                    using (var httpWebResponse = request.GetResponse() as HttpWebResponse)
                        if (httpWebResponse != null)
                            responseUri = httpWebResponse.ResponseUri.AbsoluteUri;
                            using (var streamReader = new StreamReader(httpWebResponse.GetResponseStream()))
                                result = streamReader.ReadToEnd();
                            return result;
            responseUri = null;
            return null;

How to get the title of HTML page with JavaScript?

Can use getElementsByTagName

var x = document.getElementsByTagName("title")[0];


// or


// or


Edits as suggested by Paul

Is calling destructor manually always a sign of bad design?

I have another situation where I think it is perfectly reasonable to call the destructor.

When writing a "Reset" type of method to restore an object to its initial state, it is perfectly reasonable to call the Destructor to delete the old data that is being reset.

class Widget
    char* pDataText { NULL  }; 
    int   idNumber  { 0     };

    void Setup() { pDataText = new char[100]; }
    ~Widget()    { delete pDataText;          }

    void Reset()
        Widget blankWidget;
        this->~Widget();     // Manually delete the current object using the dtor
        *this = blankObject; // Copy a blank object to the this-object.

Can I have multiple primary keys in a single table?

Some people use the term "primary key" to mean exactly an integer column that gets its values generated by some automatic mechanism. For example AUTO_INCREMENT in MySQL or IDENTITY in Microsoft SQL Server. Are you using primary key in this sense?

If so, the answer depends on the brand of database you're using. In MySQL, you can't do this, you get an error:

mysql> create table foo (
  id int primary key auto_increment, 
  id2 int auto_increment
ERROR 1075 (42000): Incorrect table definition; 
there can be only one auto column and it must be defined as a key

In some other brands of database, you are able to define more than one auto-generating column in a table.

How do I revert all local changes in Git managed project to previous state?

simply execute -

git stash

it will remove all your local changes. and you can also use it later by executing -

git stash apply 

Can you write nested functions in JavaScript?

Not only can you return a function which you have passed into another function as a variable, you can also use it for calculation inside but defining it outside. See this example:

    function calculate(a,b,fn) {
      var c = a * 3 + b + fn(a,b);
      return  c;

    function sum(a,b) {
      return a+b;

    function product(a,b) {
      return a*b;

    document.write(calculate (10,20,sum)); //80
    document.write(calculate (10,20,product)); //250

Best way to store date/time in mongodb

The best way is to store native JavaScript Date objects, which map onto BSON native Date objects.

> db.test.insert({date: ISODate()})
> db.test.insert({date: new Date()})
> db.test.find()
{ "_id" : ObjectId("..."), "date" : ISODate("2014-02-10T10:50:42.389Z") }
{ "_id" : ObjectId("..."), "date" : ISODate("2014-02-10T10:50:57.240Z") }

The native type supports a whole range of useful methods out of the box, which you can use in your map-reduce jobs, for example.

If you need to, you can easily convert Date objects to and from Unix timestamps1), using the getTime() method and Date(milliseconds) constructor, respectively.

1) Strictly speaking, the Unix timestamp is measured in seconds. The JavaScript Date object measures in milliseconds since the Unix epoch.

Can't use method return value in write context

empty() needs to access the value by reference (in order to check whether that reference points to something that exists), and PHP before 5.5 didn't support references to temporary values returned from functions.

However, the real problem you have is that you use empty() at all, mistakenly believing that "empty" value is any different from "false".

Empty is just an alias for !isset($thing) || !$thing. When the thing you're checking always exists (in PHP results of function calls always exist), the empty() function is nothing but a negation operator.

PHP doesn't have concept of emptyness. Values that evaluate to false are empty, values that evaluate to true are non-empty. It's the same thing. This code:

$x = something();
if (empty($x)) …

and this:

$x = something();
if (!$x) …

has always the same result, in all cases, for all datatypes (because $x is defined empty() is redundant).

Return value from the method always exists (even if you don't have return statement, return value exists and contains null). Therefore:

if (!empty($r->getError()))

is logically equivalent to:

if ($r->getError())

How can I change the default credentials used to connect to Visual Studio Online (TFSPreview) when loading Visual Studio up?

I had a very similiar problem as I was not able to connect to TFS with my own credentials. Turned out that the user who had created the image (I was using Hyper-V) stored his account in Credential Manager. There was no way to change this in Visual Studio. To solve the issue, I opened Credential Manager in Control Panel and edited the Generic Credentials to be my own account. I closed and opened Visual Studio 2012, and reconnected to TFS. It prompted me for my credentials, but it connected with my account from then on.

hope this helps, sivilian

Angular: Cannot Get /

Check if in index.html base is set

  <base href="/">

input checkbox true or checked or yes

Accordingly to W3C checked input's attribute can be absent/ommited or have "checked" as its value. This does not invalidate other values because there's no restriction to the browser implementation to allow values like "true", "on", "yes" and so on. To guarantee that you'll write a cross-browser checkbox/radio use checked="checked", as recommended by W3C.

disabled, readonly and ismap input's attributes go on the same way.


empty is not a valid value for checked, disabled, readonly and ismap input's attributes, as warned by @Quentin

jQuery load first 3 elements, click "load more" to display next 5 elements

The expression $(document).ready(function() deprecated in jQuery3.

See working fiddle with jQuery 3 here

Take into account I didn't include the showless button.

Here's the code:


$(function () {
    $('#myList li').slice(0, 3).show();
    $('#loadMore').on('click', function (e) {
        x = x+5;
        $('#myList li').slice(0, x).slideDown();


#myList li{display:none;
#loadMore {
#loadMore:hover {

Laravel - Route::resource vs Route::controller

For route controller method we have to define only one route. In get or post method we have to define the route separately.

And the resources method is used to creates multiple routes to handle a variety of Restful actions.

Here the Laravel documentation about this.

PHPDoc type hinting for array of objects?

I've found something which is working, it can save lives !

private $userList = array();
$userList = User::fetchAll(); // now $userList is an array of User objects
foreach ($userList as $user) {
   $user instanceof User;
   echo $user->getName();

What's the simplest way of detecting keyboard input in a script from the terminal?

These functions, based on the above, seem to work well for getting characters from the keyboard (blocking and non-blocking):

import termios, fcntl, sys, os

def get_char_keyboard():
  fd = sys.stdin.fileno()

  oldterm = termios.tcgetattr(fd)
  newattr = termios.tcgetattr(fd)
  newattr[3] = newattr[3] & ~termios.ICANON & ~termios.ECHO
  termios.tcsetattr(fd, termios.TCSANOW, newattr)

  c = None
    c =
  except IOError: pass

  termios.tcsetattr(fd, termios.TCSAFLUSH, oldterm)

  return c

def get_char_keyboard_nonblock():
  fd = sys.stdin.fileno()

  oldterm = termios.tcgetattr(fd)
  newattr = termios.tcgetattr(fd)
  newattr[3] = newattr[3] & ~termios.ICANON & ~termios.ECHO
  termios.tcsetattr(fd, termios.TCSANOW, newattr)

  oldflags = fcntl.fcntl(fd, fcntl.F_GETFL)
  fcntl.fcntl(fd, fcntl.F_SETFL, oldflags | os.O_NONBLOCK)

  c = None

    c =
  except IOError: pass

  termios.tcsetattr(fd, termios.TCSAFLUSH, oldterm)
  fcntl.fcntl(fd, fcntl.F_SETFL, oldflags)

  return c

What is the difference between jQuery: text() and html() ?

The text() method entity-escapes any HTML that is passed into it. Use text() when you want to insert HTML code that will be visible to people who view the page.

Technically, your second example produces:

&lt;a href="example.html"&gt;Link&lt;/a&gt;&lt;b&gt;hello&lt;/b&gt;

which would be rendered in the browser as:

<a href="example.html">Link</a><b>hello</b>

Your first example will be rendered as an actual link and some bold text.

Do you (really) write exception safe code?

Leaving aside the confusion between SEH and C++ exceptions, you need to be aware that exceptions can be thrown at any time, and write your code with that in mind. The need for exception-safety is largely what drives the use of RAII, smart pointers, and other modern C++ techniques.

If you follow the well-established patterns, writing exception-safe code is not particularly hard, and in fact it's easier than writing code that handles error returns properly in all cases.

How can I replace a regex substring match in Javascript?

using str.replace(regex, $1);:

var str   = 'asd-0.testing';
var regex = /(asd-)\d(\.\w+)/;

if (str.match(regex)) {
    str = str.replace(regex, "$1" + "1" + "$2");

Edit: adaptation regarding the comment

Bizarre Error in Chrome Developer Console - Failed to load resource: net::ERR_CACHE_MISS

I had issues getting through a form because of this error.

I used Ctrl+Click to click the submit button and navigate through the form as usual.

Maven: Non-resolvable parent POM

It was fixed when I removed settings.xml from .m2 folder.

Operation must use an updatable query. (Error 3073) Microsoft Access

The answer given above by iDevlop worked for me. Note that I wasn't able to find the RecordsetType property in my update query. However, I was able to find that property by changing my query to a select query, setting that property as iDevlop noted and then changing my query to an update query. This worked, no need for a temp table.

I'd have liked for this to just be a comment to what iDevlop posted so that it flowed from his solution, but I don't have a high enough score.

What is the OR operator in an IF statement

In the format for if

if (this OR that) 

this and that are expression not values. title == "aaaaa" is a valid expression. Also OR is not a valid construct in C#, you have to use ||.

SQL: Insert all records from one table to another table without specific the columns

All the answers above, for some reason or another, did not work for me on SQL Server 2012. My situation was I accidently deleted all rows instead of just one row. After our DBA restored the table to dbo.foo_bak, I used the below to restore. NOTE: This only works if the backup table (represented by dbo.foo_bak) and the table that you are writing to ( have the exact same column names.

This is what worked for me using a hybrid of a bunch of different answers:

USE [database_name];
INSERT INTO [dbo].[foo]
     SELECT * FROM [dbo].[foo_bak];

This version of my answer is helpful if you have primary and foreign keys.

can we use xpath with BeautifulSoup?

Maybe you can try the following without XPath

from simplified_scrapy.simplified_doc import SimplifiedDoc 
html = '''
    <h1>Example Domain</h1>
    <p>This domain is for use in illustrative examples in documents. You may use this
    domain in literature without prior coordination or asking for permission.</p>
    <p><a href="">More information...</a></p>
# What XPath can do, so can it
doc = SimplifiedDoc(html)
# The result is the same as doc.getElementByTag('body').getElementByTag('div').getElementByTag('h1').text
print (doc.body.div.h1.text)
print (doc.div.h1.text)
print (doc.h1.text) # Shorter paths will be faster
print (doc.div.getChildren())
print (doc.div.getChildren('p'))


Since vars passed through url are $_GET vars, you can use filter_input() function:

$id = filter_input(INPUT_GET, 'id', FILTER_SANITIZE_NUMBER_INT);
$othervar = filter_input(INPUT_GET, 'othervar', FILTER_SANITIZE_FULL_SPECIAL_CHARS);

It would store the values of each var and sanitize/validate them too.

Url decode UTF-8 in Python

If you are using Python 3, you can use urllib.parse

url = """"""

import urllib.parse



Angular 2 - Using 'this' inside setTimeout

You need to use Arrow function ()=> ES6 feature to preserve this context within setTimeout.

// var that = this;                             // no need of this line
this.messageSuccess = true;

setTimeout(()=>{                           //<<<---using ()=> syntax
      this.messageSuccess = false;
 }, 3000);

getting a checkbox array value from POST

Your $_POST array contains the invite array, so reading it out as

  $invite = $_POST['invite'];
  echo $invite;

won't work since it's an array. You have to loop through the array to get all of the values.

  if (is_array($_POST['invite'])) {
    foreach($_POST['invite'] as $value){
      echo $value;
  } else {
    $value = $_POST['invite'];
    echo $value;

React.js create loop through Array

In CurrentGame component you need to change initial state because you are trying use loop for participants but this property is undefined that's why you get error.,

getInitialState: function(){
    return {
       data: {
          participants: [] 

also, as player in .map is Object you should get properties from it {
   return <li key={player.championId}>{player.summonerName}</li>
   // -------------------^^^^^^^^^^^---------^^^^^^^^^^^^^^


Append an empty row in dataframe using pandas

The code below worked for me.

df.append(pd.Series([np.nan]), ignore_index = True)

UILabel with text of two different colors

There is a Swift 3.0 solution

extension UILabel{

    func setSubTextColor(pSubString : String, pColor : UIColor){
        let attributedString: NSMutableAttributedString = NSMutableAttributedString(string: self.text!);
        let range = attributedString.mutableString.range(of: pSubString, options:NSString.CompareOptions.caseInsensitive)
        if range.location != NSNotFound {
            attributedString.addAttribute(NSForegroundColorAttributeName, value: pColor, range: range);
        self.attributedText = attributedString


And there is an example of call :

let colorString = " (string in red)"
self.mLabel.text = "classic color" + colorString
self.mLabel.setSubTextColor(pSubString: colorString, pColor:

Eclipse keyboard shortcut to indent source code to the left?

In any version of Eclipse IDE for source code indentation.

Select the source code and use the following keys

  1. For default java indentation Ctrl + I

  2. For right indentation Tab

  3. For left indentation Shift + Tab

How to convert int to string on Arduino?

This simply work for me:

int bpm = 60;
char text[256];
sprintf(text, "Pulso: %d     ", bpm);
//now use text as string

Include another HTML file in a HTML file

I came to this topic looking for something similar, but a bit different from the problem posed by lolo. I wanted to construct an HTML page holding an alphabetical menu of links to other pages, and each of the other pages might or might not exist, and the order in which they were created might not be alphabetical (nor even numerical). Also, like Tafkadasoh, I did not want to bloat the web page with jQuery. After researching the problem and experimenting for several hours, here is what worked for me, with relevant remarks added:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
  <meta http-equiv="Content-Type" content="text/application/html; charset=iso-8859-1">
  <meta name="Author" content="me">
  <meta copyright="Copyright" content= "(C) 2013-present by me" />

<script type="text/javascript">
var F000, F001, F002, F003, F004, F005, F006, F007, F008, F009,
    F010, F011, F012, F013, F014, F015, F016, F017, F018, F019;
var dat = new Array();
var form, script, write, str, tmp, dtno, indx, unde;

The "F000" and similar variables need to exist/be-declared.
Each one will be associated with a different menu item,
so decide on how many items maximum you are likely to need,
when constructing that listing of them.  Here, there are 20.

function initialize()
  form = document.getElementById('MENU');
  for(indx=0; indx<20; indx++)
  { str = "00" + indx;
    tmp = str.length - 3;
    str = str.substr(tmp);
    script = document.createElement('script');
    script.type = 'text/javascript';
    script.src = str + ".js";

The for() loop constructs some <script> objects
and associates each one with a different simple file name,
starting with "000.js" and, here, going up to "019.js".
It won't matter which of those files exist or not.
However, for each menu item you want to display on this
page, you will need to ensure that its .js file does exist.

The short function below (inside HTML comment-block) is,
generically, what the content of each one of the .js files looks like:
function F000()
{ return ["Menu Item Name", "./URLofFile.htm", "Description string"];

(Continuing the remarks in the main menu.htm file)
It happens that each call of the form.appendChild() function
will cause the specified .js script-file to be loaded at that time.
However, it takes a bit of time for the JavaScript in the file
to be fully integrated into the web page, so one thing that I tried,
but it didn't work, was to write an "onload" event handler.
The handler was apparently being called before the just-loaded
JavaScript had actually become accessible.

Note that the name of the function in the .js file is the same as one
of the pre-defined variables like "F000".  When I tried to access
that function without declaring the variable, attempting to use an
"onload" event handler, the JavaScript debugger claimed that the item
was "not available".  This is not something that can be tested-for!
However, "undefined" IS something that CAN be tested-for.  Simply
declaring them to exist automatically makes all of them "undefined".
When the system finishes integrating a just-loaded .js script file,
the appropriate variable, like "F000", will become something other
than "undefined".  Thus it doesn't matter which .js files exist or
not, because we can simply test all the "F000"-type variables, and
ignore the ones that are "undefined".  More on that later.

The line below specifies a delay of 2 seconds, before any attempt
is made to access the scripts that were loaded.  That DOES give the
system enough time to fully integrate them into the web page.
(If you have a really long list of menu items, or expect the page
to be loaded by an old/slow computer, a longer delay may be needed.)

  window.setTimeout("BuildMenu();", 2000);

//So here is the function that gets called after the 2-second delay  
function BuildMenu()
{ dtno = 0;    //index-counter for the "dat" array
  for(indx=0; indx<20; indx++)
  { str = "00" + indx;
    tmp = str.length - 3;
    str = "F" + str.substr(tmp);
    tmp = eval(str);
    if(tmp != unde) // "unde" is deliberately undefined, for this test
      dat[dtno++] = eval(str + "()");

The loop above simply tests each one of the "F000"-type variables, to
see if it is "undefined" or not.  Any actually-defined variable holds
a short function (from the ".js" script-file as previously indicated).
We call the function to get some data for one menu item, and put that
data into an array named "dat".

Below, the array is sorted alphabetically (the default), and the
"dtno" variable lets us know exactly how many menu items we will
be working with.  The loop that follows creates some "<span>" tags,
and the the "innerHTML" property of each one is set to become an
"anchor" or "<a>" tag, for a link to some other web page.  A description
and a "<br />" tag gets included for each link.  Finally, each new
<span> object is appended to the menu-page's "form" object, and thereby
ends up being inserted into the middle of the overall text on the page.
(For finer control of where you want to put text in a page, consider
placing something like this in the web page at an appropriate place,
as preparation:
<div id="InsertHere"></div>
You could then use document.getElementById("InsertHere") to get it into
a variable, for appending of <span> elements, the way a variable named
"form" was used in this example menu page.

Note: You don't have to specify the link in the same way I did
(the type of link specified here only works if JavaScript is enabled).
You are free to use the more-standard "<a>" tag with the "href"
property defined, if you wish.  But whichever way you go,
you need to make sure that any pages being linked actually exist!

  for(indx=0; indx<dtno; indx++)
  { write = document.createElement('span');
    write.innerHTML = "<a onclick=\"'" + dat[indx][1] +
                      "', 'Menu');\" style=\"color:#0000ff;" + 
                      "text-decoration:underline;cursor:pointer;\">" +
                      dat[indx][0] + "</a> " + dat[indx][2] + "<br />";

// -->

<body onload="initialize();" style="background-color:#a0a0a0; color:#000000; 

font-family:sans-serif; font-size:11pt;">
<h2>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;MENU
<noscript><br /><span style="color:#ff0000;">
Links here only work if<br />
your browser's JavaScript<br />
support is enabled.</span><br /></noscript></h2>
These are the menu items you currently have available:<br />
<br />
<form id="MENU" action="" onsubmit="return false;">
<!-- Yes, the <form> object starts out completely empty -->
Click any link, and enjoy it as much as you like.<br />
Then use your browser's BACK button to return to this Menu,<br />
so you can click a different link for a different thing.<br />
<br />
<br />
<small>This file (web page) Copyright (c) 2013-present by me</small>

Measuring the distance between two coordinates in PHP

Try this function out to calculate distance between to points of latitude and longitude

function calculateDistanceBetweenTwoPoints($latitudeOne='', $longitudeOne='', $latitudeTwo='', $longitudeTwo='',$distanceUnit ='',$round=false,$decimalPoints='')
        if (empty($decimalPoints)) 
            $decimalPoints = '3';
        if (empty($distanceUnit)) {
            $distanceUnit = 'KM';
        $distanceUnit = strtolower($distanceUnit);
        $pointDifference = $longitudeOne - $longitudeTwo;
        $toSin = (sin(deg2rad($latitudeOne)) * sin(deg2rad($latitudeTwo))) + (cos(deg2rad($latitudeOne)) * cos(deg2rad($latitudeTwo)) * cos(deg2rad($pointDifference)));
        $toAcos = acos($toSin);
        $toRad2Deg = rad2deg($toAcos);

        $toMiles  =  $toRad2Deg * 60 * 1.1515;
        $toKilometers = $toMiles * 1.609344;
        $toNauticalMiles = $toMiles * 0.8684;
        $toMeters = $toKilometers * 1000;
        $toFeets = $toMiles * 5280;
        $toYards = $toFeets / 3;

              switch (strtoupper($distanceUnit)) 
                  case 'ML'://miles
                         $toMiles  = ($round == true ? round($toMiles) : round($toMiles, $decimalPoints));
                         return $toMiles;
                  case 'KM'://Kilometers
                        $toKilometers  = ($round == true ? round($toKilometers) : round($toKilometers, $decimalPoints));
                        return $toKilometers;
                  case 'MT'://Meters
                        $toMeters  = ($round == true ? round($toMeters) : round($toMeters, $decimalPoints));
                        return $toMeters;
                  case 'FT'://feets
                        $toFeets  = ($round == true ? round($toFeets) : round($toFeets, $decimalPoints));
                        return $toFeets;
                  case 'YD'://yards
                        $toYards  = ($round == true ? round($toYards) : round($toYards, $decimalPoints));
                        return $toYards;
                  case 'NM'://Nautical miles
                        $toNauticalMiles  = ($round == true ? round($toNauticalMiles) : round($toNauticalMiles, $decimalPoints));
                        return $toNauticalMiles;


Then use the fucntion as

echo calculateDistanceBetweenTwoPoints('11.657740','77.766270','11.074820','77.002160','ML',true,5);

Hope it helps

Is there any way to call a function periodically in JavaScript?

Please note that setInterval() is often not the best solution for periodic execution - It really depends on what javascript you're actually calling periodically.

eg. If you use setInterval() with a period of 1000ms and in the periodic function you make an ajax call that occasionally takes 2 seconds to return you will be making another ajax call before the first response gets back. This is usually undesirable.

Many libraries have periodic methods that protect against the pitfalls of using setInterval naively such as the Prototype example given by Nelson.

To achieve more robust periodic execution with a function that has a jQuery ajax call in it, consider something like this:

function myPeriodicMethod() {
    url: ..., 
    success: function(data) {
    complete: function() {
      // schedule the next request *only* when the current one is complete:
      setTimeout(myPeriodicMethod, 1000);

// schedule the first invocation:
setTimeout(myPeriodicMethod, 1000);

Another approach is to use setTimeout but track elapsed time in a variable and then set the timeout delay on each invocation dynamically to execute a function as close to the desired interval as possible but never faster than you can get responses back.

How to get a cookie from an AJAX response?

Similar to yebmouxing I could not the


method to work. It would only return null even if I had set HTTPOnly to false on my server.

I too wrote a simple js helper function to grab the cookies from the document. This function is very basic and only works if you know the additional info (lifespan, domain, path, etc. etc.) to add yourself:

function getCookie(cookieName){
  var cookieArray = document.cookie.split(';');
  for(var i=0; i<cookieArray.length; i++){
    var cookie = cookieArray[i];
    while (cookie.charAt(0)==' '){
      cookie = cookie.substring(1);
    cookieHalves = cookie.split('=');
    if(cookieHalves[0]== cookieName){
      return cookieHalves[1];
  return "";

Python: Assign print output to a variable

Please note, I wrote this answer based on Python 3.x. No worries you can assign print() statement to the variable like this.

>>> var = print('some text')
some text
>>> var
>>> type(var)
<class 'NoneType'>

According to the documentation,

All non-keyword arguments are converted to strings like str() does and written to the stream, separated by sep and followed by end. Both sep and end must be strings; they can also be None, which means to use the default values. If no objects are given, print() will just write end.

The file argument must be an object with a write(string) method; if it is not present or None, sys.stdout will be used. Since printed arguments are converted to text strings, print() cannot be used with binary mode file objects. For these, use file.write(...) instead.

That's why we cannot assign print() statement values to the variable. In this question you have ask (or any function). So print() also a function with the return value with None. So the return value of python function is None. But you can call the function(with parenthesis ()) and save the return value in this way.

>>> var = some_function()

So the var variable has the return value of some_function() or the default value None. According to the documentation about print(), All non-keyword arguments are converted to strings like str() does and written to the stream. Lets look what happen inside the str().

Return a string version of object. If object is not provided, returns the empty string. Otherwise, the behavior of str() depends on whether encoding or errors is given, as follows.

So we get a string object, then you can modify the below code line as follows,

>>> var = str(some_function())

or you can use str.join() if you really have a string object.

Return a string which is the concatenation of the strings in iterable. A TypeError will be raised if there are any non-string values in iterable, including bytes objects. The separator between elements is the string providing this method.

change can be as follows,

>>> var = ''.join(some_function())  # you can use this if some_function() really returns a string value

How do I change the color of radio buttons?

A clever way to do it would be to create a separate div with a height and width of -for example- 50px and then a radius of 50px lay this over your radio buttons...

Excel: macro to export worksheet as CSV file without leaving my current Excel sheet

Almost what I wanted @Ralph, but here is the best answer. It'll solve your code problems:

  1. it exports just the hardcoded sheet named "Sheet1";
  2. it always exports to the same temp file, overwriting it;
  3. it ignores the locale separation char.

To solve these problems, and meet all my requirements, I've adapted the code from here. I've cleaned it a little to make it more readable.

Option Explicit
Sub ExportAsCSV()
    Dim MyFileName As String
    Dim CurrentWB As Workbook, TempWB As Workbook
    Set CurrentWB = ActiveWorkbook
    Set TempWB = Application.Workbooks.Add(1)
    With TempWB.Sheets(1).Range("A1")
      .PasteSpecial xlPasteValues
      .PasteSpecial xlPasteFormats
    End With        

    Dim Change below to "- 4"  to become compatible with .xls files
    MyFileName = CurrentWB.Path & "\" & Left(CurrentWB.Name, Len(CurrentWB.Name) - 5) & ".csv"
    Application.DisplayAlerts = False
    TempWB.SaveAs Filename:=MyFileName, FileFormat:=xlCSV, CreateBackup:=False, Local:=True
    TempWB.Close SaveChanges:=False
    Application.DisplayAlerts = True
End Sub

There are still some small thing with the code above that you should notice:

  1. .Close and DisplayAlerts=True should be in a finally clause, but I don't know how to do it in VBA
  2. It works just if the current filename has 4 letters, like .xlsm. Wouldn't work in .xls excel old files. For file extensions of 3 chars, you must change the - 5 to - 4 when setting MyFileName.
  3. As a collateral effect, your clipboard will be substituted with current sheet contents.

Edit: put Local:=True to save with my locale CSV delimiter.

Make Https call using HttpClient

I had the same problem when connecting to GitHub, which requires a user agent. Thus it is sufficient to provide this rather than generating a certificate

var client = new HttpClient();

client.BaseAddress = new Uri("");
    "token 123456789307d8c1d138ddb0848ede028ed30567");
    new MediaTypeWithQualityHeaderValue("application/json"));
    "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36");

Smooth scrolling with just pure css

You can do this with pure CSS but you will need to hard code the offset scroll amounts, which may not be ideal should you be changing page content- or should dimensions of your content change on say window resize.

You're likely best placed to use e.g. jQuery, specifically:

$('html, body').stop().animate({
   scrollTop: element.offset().top
}, 1000);

A complete implementation may be:

$('#up, #down').on('click', function(e){
    var target= $(this).get(0).id == 'up' ? $('#down') : $('#up');
    $('html, body').stop().animate({
       scrollTop: target.offset().top
    }, 1000);

Where element is the target element to scroll to and 1000 is the delay in ms before completion.

Demo Fiddle

The benefit being, no matter what changes to your content dimensions, the function will not need to be altered.

Full Screen DialogFragment in Android

Try switching to a LinearLayout instead of RelativeLayout. I was targeting the 3.0 Honeycomb api when testing.

public class FragmentDialog extends Activity {

protected void onCreate(Bundle savedInstanceState) {

    Button button = (Button) findViewById(;
    button.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {

public void onSaveInstanceState(Bundle outState) {

void showDialog() {
    FragmentTransaction ft = getFragmentManager().beginTransaction();
    DialogFragment newFragment = MyDialogFragment.newInstance();, "dialog");

public static class MyDialogFragment extends DialogFragment {

    static MyDialogFragment newInstance() {
        MyDialogFragment f = new MyDialogFragment();
        return f;

    public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.fragment_dialog, container, false);
        return v;


and the layouts: fragment_dialog.xml

<?xml version="1.0" encoding="utf-8"?>


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android=""
    <Button android:id="@+id/show"

How to customise the Jackson JSON mapper implicitly used by Spring Boot?

You can add a following method inside your bootstrap class which is annotated with @SpringBootApplication

    public ObjectMapper objectMapper(Jackson2ObjectMapperBuilder builder) {
    ObjectMapper objectMapper = builder.createXmlMapper(false).build();
    objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
    objectMapper.configure(SerializationFeature.WRITE_DATE_TIMESTAMPS_AS_NANOSECONDS, false);

    objectMapper.registerModule(new JodaModule());

    return objectMapper;

HTML5 Canvas background image

Canvas does not using .png file as background image. changing to other file extensions like gif or jpg works fine.

Function or sub to add new row and data to table

Is this what you are looking for?

Option Explicit

Public Sub addDataToTable(ByVal strTableName As String, ByVal strData As String, ByVal col As Integer)
    Dim lLastRow As Long
    Dim iHeader As Integer

    With ActiveSheet.ListObjects(strTableName)
        'find the last row of the list
        lLastRow = ActiveSheet.ListObjects(strTableName).ListRows.Count
        'shift from an extra row if list has header
        If .Sort.Header = xlYes Then
            iHeader = 1
            iHeader = 0
        End If
    End With
    'add the data a row after the end of the list
    ActiveSheet.Cells(lLastRow + 1 + iHeader, col).Value = strData
End Sub

It handles both cases whether you have header or not.

How to convert const char* to char* in C?

A const to a pointer indicates a "read-only" memory location. Whereas the ones without const are a read-write memory areas. So, you "cannot" convert a const(read-only location) to a normal(read-write) location.

The alternate is to copy the data to a different read-write location and pass this pointer to the required function. You may use strdup() to perform this action.

SQL Server IIF vs CASE

IIF is a non-standard T-SQL function. It was added to SQL SERVER 2012, so that Access could migrate to SQL Server without refactoring the IIF's to CASE before hand. Once the Access db is fully migrated into SQL Server, you can refactor.

Resize command prompt through commands

If you want to run a .bat file in full screen, right click on the "example.bat" and click create shortcut, then right click on the shortcut and click properties, then click layout, in layout you can adjust your file to the screen manually, however you can only run it this way if you use the shortcut. You can also change font size by clicking font instead of layout, select lucida and adjust the font size then click apply

How do I remove a specific element from a JSONArray?

To Remove some element from Listview in android then it will remove your specific element and Bind it to listview.



Cannot change version of project facet Dynamic Web Module to 3.0?

updating maven worked for me

select project then press ALT+F5 then select project click ok

Rotate image with javascript

CSS can be applied and you will have to set transform-origin correctly to get the applied transformation in the way you want

See the fiddle:

Main code:

/* assuming that the image's height is 70px */

img.rotated {
    transform: rotate(90deg);
    -webkit-transform: rotate(90deg);
    -moz-transform: rotate(90deg);
    -ms-transform: rotate(90deg);

    transform-origin: 35px 35px;
    -webkit-transform-origin: 35px 35px;
    -moz-transform-origin: 35px 35px;
    -ms-transform-origin: 35px 35px;

jQuery and JS:

    .css('transform-origin-x', imgWidth / 2)
    .css('transform-origin-y', imgHeight / 2);

// By calculating the height and width of the image in the load function

// $(img).css('transform-origin', (imgWidth / 2) + ' ' + (imgHeight / 2) );


Divide the image's height by 2. The transform-x and transform-y values should be this value


transform-origin at CSS | MDN

Read a plain text file with php

W3Schools is your friend:

And here: has more info on fopen including what the modes are.

What W3Schools says:

$file = fopen("test.txt","r");

while(! feof($file))
  echo fgets($file). "<br />";


fopen opens the file (in this case test.txt with mode 'r' which means read-only and places the pointer at the beginning of the file)

The while loop tests to check if it's at the end of file (feof) and while it isn't it calls fgets which gets the current line where the pointer is.

Continues doing this until it is the end of file, and then closes the file.

Generate random password string with requirements in javascript

Based on @Ryan Shillington answer above you may find this enhancment helpfull too. Think this is more secured then what was requeted on the original request in the question above.

  1. Password generated with at least 1 number, 1 upper case character, 1 lower case character and 1 Special character
  2. Password length is dynamic

//Password generated with at least 1 number, 1 upper case character, 1 lower case character and 1 Special character
function generatePassword() 
      var passwordLength = randomIntFromInterval(10,20);    
      var numberChars = "0123456789";
      var lowerChars = "abcdefghijklmnopqrstuvwxyz";
      var specialChars = "~!#$%&*-+|";
      var allChars = numberChars + upperChars + lowerChars + specialChars;
      var randPasswordArray = Array(passwordLength);
      randPasswordArray[0] = numberChars;
      randPasswordArray[1] = upperChars;
      randPasswordArray[2] = lowerChars;
      randPasswordArray[3] = specialChars;
      randPasswordArray = randPasswordArray.fill(allChars, 4);
      if(window.crypto && window.crypto.getRandomValues)
          return shuffleArray( { return x[Math.floor(window.crypto.getRandomValues(new Uint32Array(1))[0] / (0xffffffff + 1) * x.length)] })).join('');  
      else if(window.msCrypto && window.msCrypto.getRandomValues) 
          return shuffleArray( { return x[Math.floor(window.msCrypto.getRandomValues(new Uint32Array(1))[0] / (0xffffffff + 1) * x.length)] })).join('');
          return shuffleArray( { return x[Math.floor(Math.random() * x.length)] })).join('');

    function shuffleArray(array) 
      for (var i = array.length - 1; i > 0; i--) {
        var j = Math.floor(Math.random() * (i + 1));
        var temp = array[i];
        array[i] = array[j];
        array[j] = temp;
     return array;

//generate random number in the range (min and max included)
function randomIntFromInterval(min, max) {
      return Math.floor(Math.random() * (max - min + 1) + min);
<input type='text' id='p9'/>
<input type='button' value ='pass generator' onclick='document.getElementById("p9").value = generatePassword()'>

Fixing Sublime Text 2 line endings?

to chnage line endings from LF to CRLF:

open Sublime and follow the steps:-

1 press Ctrl+shift+p then install package name line unify endings

then again press Ctrl+shift+p

2 in the blank input box type "Line unify ending "

3 Hit enter twice

Sublime may freeze for sometimes and as a result will change the line endings from LF to CRLF

SQL Server: use CASE with LIKE

Add an END at last before alias name.

CASE WHEN countries LIKE '%'+@selCountry+'%' 
     THEN 'national' ELSE 'regional' 
END AS validity

For example:

SELECT CASE WHEN countries LIKE '%'+@selCountry+'%' 
       THEN 'national' ELSE 'regional' 
       END AS validity
FROM TableName

Version vs build in Xcode

Another way is to set the version number in appDelegate didFinishLaunchingWithOptions:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
     NSString * ver = [self myVersion];
     NSLog(@"version: %@",ver);

     NSUserDefaults* userDefaults = [NSUserDefaults standardUserDefaults];
     [userDefaults setObject:ver forKey:@"version"];
     return YES;

- (NSString *) myVersion {
    NSString *version = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleShortVersionString"];
    NSString *build = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleVersion"];
    return [NSString stringWithFormat:@"%@ build %@", version, build];

Detecting an "invalid date" Date instance in JavaScript

You can check the validity of a Date object d via

d instanceof Date && isFinite(d)

To avoid cross-frame issues, one could replace the instanceof check with === '[object Date]'

A call to getTime() as in Borgar's answer is unnecessary as isNaN() and isFinite() both implicitly convert to number.

UIImage: Resize, then Crop

This is a version of Jane Sales' answer in Swift. Cheers!

public func resizeImage(image: UIImage, size: CGSize) -> UIImage? {
    var returnImage: UIImage?

    var scaleFactor: CGFloat = 1.0
    var scaledWidth = size.width
    var scaledHeight = size.height
    var thumbnailPoint = CGPointMake(0, 0)

    if !CGSizeEqualToSize(image.size, size) {
        let widthFactor = size.width / image.size.width
        let heightFactor = size.height / image.size.height

        if widthFactor > heightFactor {
            scaleFactor = widthFactor
        } else {
            scaleFactor = heightFactor

        scaledWidth = image.size.width * scaleFactor
        scaledHeight = image.size.height * scaleFactor

        if widthFactor > heightFactor {
            thumbnailPoint.y = (size.height - scaledHeight) * 0.5
        } else if widthFactor < heightFactor {
            thumbnailPoint.x = (size.width - scaledWidth) * 0.5

    UIGraphicsBeginImageContextWithOptions(size, true, 0)

    var thumbnailRect = CGRectZero
    thumbnailRect.origin = thumbnailPoint
    thumbnailRect.size.width = scaledWidth
    thumbnailRect.size.height = scaledHeight

    returnImage = UIGraphicsGetImageFromCurrentImageContext()


    return returnImage

Remove/ truncate leading zeros by javascript/jquery

Since you said "any string", I'm assuming this is a string you want to handle, too.

"00012  34 0000432    0035"

So, regex is the way to go:

var trimmed = s.replace(/\b0+/g, "");

And this will prevent loss of a "000000" value.

var trimmed = s.replace(/\b(0(?!\b))+/g, "")

You can see a working example here

Datatables - Setting column width

for who still having issues with 1.9.4 change

//oSettings.aoColumns[i] = _fnStringToCss(oSettings.aoColumns[i].sWidth);
oSettings.aoColumns[i] = _fnStringToCss(oSettings.aoColumns[i].sWidth);

Android Studio: Plugin with id 'android-library' not found


apply plugin: ''

to convert an app module to a library module. More info here:

How can I create numbered map markers in Google Maps V3?

This has now been added to the Mapping documentation and requires no third party code.

You can combine these two samples:

To get code like this:

var labelIndex = 0;

function initialize() {
  var bangalore = { lat: 12.97, lng: 77.59 };
  var map = new google.maps.Map(document.getElementById('map-canvas'), {
    zoom: 12,
    center: bangalore

  // This event listener calls addMarker() when the map is clicked.
  google.maps.event.addListener(map, 'click', function(event) {
    addMarker(event.latLng, map);

  // Add a marker at the center of the map.
  addMarker(bangalore, map);

// Adds a marker to the map.
function addMarker(location, map) {
  // Add the marker at the clicked location, and add the next-available label
  // from the array of alphabetical characters.
  var marker = new google.maps.Marker({
    position: location,
    label: labels[labelIndex],
    map: map,
    icon: 'image.png'

google.maps.event.addDomListener(window, 'load', initialize);

Note that if you have more than 35 markers, this method will not work as the label only shows the first character (using A-Z and 0-9 makes 35). Please vote for this Google Maps Issue to request that this restriction be lifted.

How to import keras from tf.keras in Tensorflow?

I had the same problem with Tensorflow 2.0.0 in PyCharm. PyCharm did not recognize tensorflow.keras; I updated my PyCharm and the problem was resolved!

Android Studio: Unable to start the daemon process

You need to install all necessary packages with Android SDK Manager:

  • Android SDK Tools

  • Android SDK Platform-tools

  • Android SDK Build-tools

  • SDK Platform

  • ARM\Intel System Image

  • Android Support Repository

  • Android Support Library

Bootstrap number validation

You should use jquery validation because if you use type="number" then you can also enter "E" character in input type, which is not correct.



<input class="form-control floatNumber" name="energy1_total_power_generated" type="text" required="" > 


//integer value validation
$('input.floatNumber').on('input', function() {
    this.value = this.value.replace(/[^0-9.]/g,'').replace(/(\..*)\./g, '$1');

How to detect if user select cancel InputBox VBA Excel

Following example uses InputBox method to validate user entry to unhide sheets: Important thing here is to use wrap InputBox variable inside StrPtr so it could be compared to '0' when user chose to click 'x' icon on the InputBox.

Sub unhidesheet()

Dim ws As Worksheet
Dim pw As String

pw = InputBox("Enter Password to Unhide Sheets:", "Unhide Data Sheets")
If StrPtr(pw) = 0 Then

   Exit Sub
ElseIf pw = NullString Then
   Exit Sub
ElseIf pw = 123456 Then
    For Each ws In ThisWorkbook.Worksheets
        ws.Visible = xlSheetVisible
End If
End Sub

How can I manually set an Angular form field as invalid?

Here is an example that works:

MatchPassword(AC: FormControl) {
  let dataForm = AC.parent;
  if(!dataForm) return null;

  var newPasswordRepeat = dataForm.get('newPasswordRepeat');
  let password = dataForm.get('newPassword').value;
  let confirmPassword = newPasswordRepeat.value;

  if(password != confirmPassword) {
    /* for newPasswordRepeat from current field "newPassword" */
    dataForm.controls["newPasswordRepeat"].setErrors( {MatchPassword: true} );
    if( newPasswordRepeat == AC ) {
      /* for current field "newPasswordRepeat" */
      return {newPasswordRepeat: {MatchPassword: true} };
  } else {
    dataForm.controls["newPasswordRepeat"].setErrors( null );
  return null;

createForm() {
  this.dataForm ={
    password: [ "", Validators.required ],
    newPassword: [ "", [ Validators.required, Validators.minLength(6), this.MatchPassword] ],
    newPasswordRepeat: [ "", [Validators.required, this.MatchPassword] ]

Set up git to pull and push all branches

The simplest way is to do:

git push --all origin

This will push tags and branches.

C# Version Of SQL LIKE

public static bool Like(this string value, string pattern)
    if (string.IsNullOrEmpty(value) || string.IsNullOrEmpty(pattern))
        return false;

    bool valid = true;
    string[] words = pattern.Split("*");
    int counter = words.Count();

    for (int i = 0; i < counter; i++)
        valid = valid && value.StartsWith(words[i]);                
        value = value.Substring(words[i].Length);
    return valid;

php implode (101) with quotes

$id = array(2222,3333,4444,5555,6666);
$ids = "'".implode("','",$id)."'";


$ids = sprintf("'%s'", implode("','", $id ) );

Stuck at ".android/repositories.cfg could not be loaded."

For Windows 7 and above go to C:\Users\USERNAME\.android folder and follow below steps:

  1. Right click > create a new txt file with name repositories.txt
  2. Open the file and go to File > Save As.. > select Save as type: All Files
  3. Rename repositories.txt to repositories.cfg

error_log per Virtual Host?

If somebody comes looking it should look like this:

<VirtualHost *:80>
    DocumentRoot /var/www/domains/
    ErrorLog /var/www/domains/
    CustomLog /var/www/domains/ common
    php_flag log_errors on
    php_flag display_errors on
    php_value error_reporting 2147483647
    php_value error_log /var/www/domains/

This is for development only since display_error is turned on. You will notice that the Apache error log is separate from the PHP error log. The good stuff is in php.error.log.

Take a look here for the error_reporting key

Read Numeric Data from a Text File in C++

you could read and write to a seperately like others. But if you want to write into the same one, you could try with this:

#include <iostream>
#include <fstream>

using namespace std;

int main() {

    double data[size of your data];

    std::ifstream input("file.txt");

    for (int i = 0; i < size of your data; i++) {
        input >> data[i];
        std::cout<< data[i]<<std::endl;


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

Check "Virtualization" status under performance option in your task manager. If you already have enabled it in your BIOS and still status is "Disabled", then go to bios, disable it and save & exit. Restart or shut down again. Enable it in BIOS again and save & exit. This time you'll see the status changed to "Enabled", It took me 3 attempts (don't know why it took that much time, but finally it worked).

How do you reindex an array in PHP but with indexes starting from 1?

I just found out you can also do a

array_splice($ar, 0, 0);

That does the re-indexing inplace, so you don't end up with a copy of the original array.

Can anybody tell me details about hs_err_pid.log file generated when Tomcat crashes?

A very very good document regarding this topic is Troubleshooting Guide for Java from (originally) Sun. See the chapter "Troubleshooting System Crashes" for information about hs_err_pid* Files.

See Appendix C - Fatal Error Log

Per the guide, by default the file will be created in the working directory of the process if possible, or in the system temporary directory otherwise. A specific location can be chosen by passing in the -XX:ErrorFile product flag. It says:

If the -XX:ErrorFile= file flag is not specified, the system attempts to create the file in the working directory of the process. In the event that the file cannot be created in the working directory (insufficient space, permission problem, or other issue), the file is created in the temporary directory for the operating system.

How to access nested elements of json object using getJSONArray method

This is for Nikola.

    public static JSONObject setProperty(JSONObject js1, String keys, String valueNew) throws JSONException {
    String[] keyMain = keys.split("\\.");
    for (String keym : keyMain) {
        Iterator iterator = js1.keys();
        String key = null;
        while (iterator.hasNext()) {
            key = (String);
            if ((js1.optJSONArray(key) == null) && (js1.optJSONObject(key) == null)) {
                if ((key.equals(keym)) && (js1.get(key).toString().equals(valueMain))) {
                    js1.put(key, valueNew);
                    return js1;
            if (js1.optJSONObject(key) != null) {
                if ((key.equals(keym))) {
                    js1 = js1.getJSONObject(key);
            if (js1.optJSONArray(key) != null) {
                JSONArray jArray = js1.getJSONArray(key);
                JSONObject j;
                for (int i = 0; i < jArray.length(); i++) {
                    js1 = jArray.getJSONObject(i);
    return js1;

public static void main(String[] args) throws IOException, JSONException {
    String text = "{ "key1":{ "key2":{ "key3":{ "key4":[ { "fieldValue":"Empty", "fieldName":"Enter Field Name 1" }, { "fieldValue":"Empty", "fieldName":"Enter Field Name 2" } ] } } } }";
    JSONObject json = new JSONObject(text);
    setProperty(json, "ke1.key2.key3.key4.fieldValue", "nikola");


If it's help bro,Do not forget to up for my reputation)))

How to change the decimal separator of DecimalFormat from comma to dot/point?

public String getGermanCurrencyFormat(double value) {
    NumberFormat nf = NumberFormat.getNumberInstance(Locale.GERMAN);
    return "€ " + nf.format(value);

How to open a different activity on recyclerView item onclick

Simply you can do it easy... You just need to get the context of your activity, here, from your View.

//Create intent getting the context of your View and the class where you want to go
Intent intent = new Intent(view.getContext(), YourClass.class);

//start the activity from the view/context
view.getContext().startActivity(intent); //If you are inside activity, otherwise pass context to this funtion

Remember that you need to modify AndroidManifest.xml and place the activity...

        android:label="Label for your activity"></activity>

How can I programmatically freeze the top row of an Excel worksheet in Excel 2007 VBA?

To expand this question into the realm of use outside of Excel s own VBA, the ActiveWindow property must be addressed as a child of the Excel.Application object.

Example for creating an Excel workbook from Access:

Using the Excel.Application object in another Office application's VBA project will require you to add Microsoft Excel 15.0 Object library (or equivalent for your own version).

Option Explicit

Sub xls_Build__Report()
    Dim xlApp As Excel.Application, ws As Worksheet, wb As Workbook
    Dim fn As String

    Set xlApp = CreateObject("Excel.Application")
    xlApp.DisplayAlerts = False
    xlApp.Visible = True

    Set wb = xlApp.Workbooks.Add
    With wb
        .Sheets(1).Name = "Report"
        With .Sheets("Report")

            'report generation here

        End With

        'This is where the Freeze Pane is dealt with
        'Freezes top row
        With xlApp.ActiveWindow
            .SplitColumn = 0
            .SplitRow = 1
            .FreezePanes = True
        End With

        fn = CurrentProject.Path & "\Reports\Report_" & Format(Date, "yyyymmdd") & ".xlsx"
        If CBool(Len(Dir(fn, vbNormal))) Then Kill fn
        .SaveAs FileName:=fn, FileFormat:=xlOpenXMLWorkbook
    End With

    wb.Close False
End Sub

The core process is really just a reiteration of previously submitted answers but I thought it was important to demonstrate how to deal with ActiveWindow when you are not within Excel's own VBA. While the code here is VBA, it should be directly transcribable to other languages and platforms.

How to create full compressed tar file using Python?

In this tar.gz file compress in open view directory In solve use os.path.basename(file_directory)

      for file in ["a.txt","b.log","c.png"]:

its use in tar.gz file compress in directory

Getting json body in aws Lambda via API gateway

There are two different Lambda integrations you can configure in API Gateway, such as Lambda integration and Lambda proxy integration. For Lambda integration, you can customise what you are going to pass to Lambda in the payload that you don't need to parse the body, but when you are using Lambda Proxy integration in API Gateway, API Gateway will proxy everything to Lambda in payload like this,

    "message": "Hello me!",
    "input": {
        "path": "/test/hello",
        "headers": {
            "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
            "Accept-Encoding": "gzip, deflate, lzma, sdch, br",
            "Accept-Language": "en-US,en;q=0.8",
            "CloudFront-Forwarded-Proto": "https",
            "CloudFront-Is-Desktop-Viewer": "true",
            "CloudFront-Is-Mobile-Viewer": "false",
            "CloudFront-Is-SmartTV-Viewer": "false",
            "CloudFront-Is-Tablet-Viewer": "false",
            "CloudFront-Viewer-Country": "US",
            "Host": "",
            "Upgrade-Insecure-Requests": "1",
            "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.82 Safari/537.36 OPR/39.0.2256.48",
            "Via": "1.1 (CloudFront)",
            "X-Amz-Cf-Id": "nBsWBOrSHMgnaROZJK1wGCZ9PcRcSpq_oSXZNQwQ10OTZL4cimZo3g==",
            "X-Forwarded-For": ",",
            "X-Forwarded-Port": "443",
            "X-Forwarded-Proto": "https"
        "pathParameters": {"proxy": "hello"},
        "requestContext": {
            "accountId": "123456789012",
            "resourceId": "us4z18",
            "stage": "test",
            "requestId": "41b45ea3-70b5-11e6-b7bd-69b5aaebc7d9",
            "identity": {
                "cognitoIdentityPoolId": "",
                "accountId": "",
                "cognitoIdentityId": "",
                "caller": "",
                "apiKey": "",
                "sourceIp": "",
                "cognitoAuthenticationType": "",
                "cognitoAuthenticationProvider": "",
                "userArn": "",
                "userAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.82 Safari/537.36 OPR/39.0.2256.48",
                "user": ""
            "resourcePath": "/{proxy+}",
            "httpMethod": "GET",
            "apiId": "wt6mne2s9k"
        "resource": "/{proxy+}",
        "httpMethod": "GET",
        "queryStringParameters": {"name": "me"},
        "stageVariables": {"stageVarName": "stageVarValue"},
        "body": "{\"foo\":\"bar\"}",
        "isBase64Encoded": false

For the example you are referencing, it is not getting the body from the original request. It is constructing the response body back to API Gateway. It should be in this format,

    "statusCode": httpStatusCode,
    "headers": { "headerName": "headerValue", ... },
    "body": "...",
    "isBase64Encoded": false

Change event on select with knockout binding, how can I know if it is a real change?

If you are working using Knockout, use the key functionality of observable functionality knockout.
Use ko.computed() method and do and trigger ajax call within that function.

centos: Another MySQL daemon already running with the same unix socket

It's just happen because of abnormal termination of mysql service. delete or take backup of /var/lib/mysql/mysql.sock file and restart mysql.

Please let me know if in case any issue..

how to install Lex and Yacc in Ubuntu?

Use the synaptic packet manager in order to install yacc / lex. If you are feeling more comfortable doing this on the console just do:

sudo apt-get install bison flex

There are some very nice articles on the net on how to get started with those tools. I found the article from CodeProject to be quite good and helpful (see here). But you should just try and search for "introduction to lex", there are plenty of good articles showing up.

What difference does .AsNoTracking() make?

The difference is that in the first case the retrieved user is not tracked by the context so when you are going to save the user back to database you must attach it and set correctly state of the user so that EF knows that it should update existing user instead of inserting a new one. In the second case you don't need to do that if you load and save the user with the same context instance because the tracking mechanism handles that for you.

sql searching multiple words in a string

Oracle SQL:

There is the "IN" Operator in Oracle SQL which can be used for that:

    namet.customerfirstname,, addrt.postalcode
from schemax.nametable namet
join schemax.addresstable addrt on addrt.adtid = namet.natadtid
where namet.customerfirstname in ('David', 'Moses', 'Robi');