Programs & Examples On #Jailbreak

Questions related to the process of gaining root access to a mobile device for the purpose of software and OS modification. This term is generally used in association with iOS devices, but can be used to describe the rooting process for other devices.

How to fix itunes could not connect to the iphone because an invalid response was received from the device?

Try resetting your network settings

Settings -> General -> Reset -> Reset Network Settings

And try deleting the contents of your mac/pc lockdown folder. Here's the link, follow the steps on "Reset the Lockdown folder".

http://support.apple.com/kb/ts2529

This one worked for me.

Min and max value of input in angular4 application

If you are looking to validate length use minLength and maxLength instead.

querySelector, wildcard element match?

There is a way by saying what is is not. Just make the not something it never will be. A good css selector reference: https://www.w3schools.com/cssref/css_selectors.asp which shows the :not selector as follows:

:not(selector)  :not(p) Selects every element that is not a <p> element

Here is an example: a div followed by something (anything but a z tag)

div > :not(z){
 border:1px solid pink;
}

How to select a div element in the code-behind page?

@CarlosLanderas is correct depending on where you've placed the DIV control. The DIV by the way is not technically an ASP control, which is why you cannot find it directly like other controls. But the best way around this is to turn it into an ASP control.

Use asp:Panel instead. It is rendered into a <div> tag anyway...

<asp:Panel id="divSubmitted" runat="server" style="text-align:center" visible="false">
   <asp:Label ID="labSubmitted" runat="server" Text="Roll Call Submitted"></asp:Label>
</asp:Panel>

And in code behind, simply find the Panel control as per normal...

Panel DivCtl1 = (Panel)gvRollCall.FooterRow.FindControl("divSubmitted");
if (DivCtl1 != null)
    DivCtl1.Visible = true;

Please note that I've used FooterRow, as my "psuedo div" is inside the footer row of a Gridview control.

Good coding!

How does C compute sin() and other math functions?

There's nothing like hitting the source and seeing how someone has actually done it in a library in common use; let's look at one C library implementation in particular. I chose uLibC.

Here's the sin function:

http://git.uclibc.org/uClibc/tree/libm/s_sin.c

which looks like it handles a few special cases, and then carries out some argument reduction to map the input to the range [-pi/4,pi/4], (splitting the argument into two parts, a big part and a tail) before calling

http://git.uclibc.org/uClibc/tree/libm/k_sin.c

which then operates on those two parts. If there is no tail, an approximate answer is generated using a polynomial of degree 13. If there is a tail, you get a small corrective addition based on the principle that sin(x+y) = sin(x) + sin'(x')y

Calculate time difference in Windows batch file

Aacini's latest code showcases an awesome variable substitution method.
It's a shame it's not Regional format proof - it fails on so many levels.
Here's a short fix that keeps the substitution+math method intact:

@echo off
setlocal EnableDelayedExpansion

set "startTime=%time: =0%" & rem AveYo: fix single digit hour

set /P "=Any process here..."

set "endTime=%time: =0%" & rem AveYo: fix single digit hour

rem Aveyo: Regional format fix with just one aditional line
for /f "tokens=1-3 delims=0123456789" %%i in ("%endTime%") do set "COLON=%%i" & set "DOT=%%k" 

rem Get elapsed time:
set "end=!endTime:%DOT%=%%100)*100+1!" & set "start=!startTime:%DOT%=%%100)*100+1!"
set /A "elap=((((10!end:%COLON%=%%100)*60+1!%%100)-((((10!start:%COLON%=%%100)*60+1!%%100)"

rem Aveyo: Fix 24 hours 
set /A "elap=!elap:-=8640000-!"

rem Convert elapsed time to HH:MM:SS:CC format:
set /A "cc=elap%%100+100,elap/=100,ss=elap%%60+100,elap/=60,mm=elap%%60+100,hh=elap/60+100"

echo Start:    %startTime%
echo End:      %endTime%
echo Elapsed:  %hh:~1%%COLON%%mm:~1%%COLON%%ss:~1%%DOT%%cc:~1% & rem AveYo: display as regional
pause

*

"Lean and Mean" TIMER with Regional format, 24h and mixed input support
Adapting Aacini's substitution method body, no IF's, just one FOR (my regional fix)

1: File timer.bat placed somewhere in %PATH% or the current dir

@echo off & rem :AveYo: compact timer function with Regional format, 24-hours and mixed input support
if not defined timer_set (if not "%~1"=="" (call set "timer_set=%~1") else set "timer_set=%TIME: =0%") & goto :eof
(if not "%~1"=="" (call set "timer_end=%~1") else set "timer_end=%TIME: =0%") & setlocal EnableDelayedExpansion
for /f "tokens=1-6 delims=0123456789" %%i in ("%timer_end%%timer_set%") do (set CE=%%i&set DE=%%k&set CS=%%l&set DS=%%n)
set "TE=!timer_end:%DE%=%%100)*100+1!"     & set "TS=!timer_set:%DS%=%%100)*100+1!"
set/A "T=((((10!TE:%CE%=%%100)*60+1!%%100)-((((10!TS:%CS%=%%100)*60+1!%%100)" & set/A "T=!T:-=8640000-!"
set/A "cc=T%%100+100,T/=100,ss=T%%60+100,T/=60,mm=T%%60+100,hh=T/60+100"
set "value=!hh:~1!%CE%!mm:~1!%CE%!ss:~1!%DE%!cc:~1!" & if "%~2"=="" echo/!value!
endlocal & set "timer_end=%value%" & set "timer_set=" & goto :eof

Usage:
timer & echo start_cmds & timeout /t 3 & echo end_cmds & timer
timer & timer "23:23:23,00"
timer "23:23:23,00" & timer
timer "13.23.23,00" & timer "03:03:03.00"
timer & timer "0:00:00.00" no & cmd /v:on /c echo until midnight=!timer_end!
Input can now be mixed, for those unlikely, but possible time format changes during execution

2: Function :timer bundled with the batch script (sample usage below):

@echo off
set "TIMER=call :timer" & rem short macro
echo.
echo EXAMPLE:
call :timer
timeout /t 3 >nul & rem Any process here..
call :timer
echo.
echo SHORT MACRO:
%TIMER% & timeout /t 1 & %TIMER% 
echo.
echo TEST INPUT:
set "start=22:04:04.58"
set "end=04.22.44,22"
echo %start% ~ start & echo %end% ~ end
call :timer "%start%"
call :timer "%end%"
echo.
%TIMER% & %TIMER% "00:00:00.00" no 
echo UNTIL MIDNIGHT: %timer_end%
echo.
pause 
exit /b

:: to test it, copy-paste both above and below code sections

rem :AveYo: compact timer function with Regional format, 24-hours and mixed input support 
:timer Usage " call :timer [input - optional] [no - optional]" :i Result printed on second call, saved to timer_end 
if not defined timer_set (if not "%~1"=="" (call set "timer_set=%~1") else set "timer_set=%TIME: =0%") & goto :eof
(if not "%~1"=="" (call set "timer_end=%~1") else set "timer_end=%TIME: =0%") & setlocal EnableDelayedExpansion
for /f "tokens=1-6 delims=0123456789" %%i in ("%timer_end%%timer_set%") do (set CE=%%i&set DE=%%k&set CS=%%l&set DS=%%n)
set "TE=!timer_end:%DE%=%%100)*100+1!"     & set "TS=!timer_set:%DS%=%%100)*100+1!"
set/A "T=((((10!TE:%CE%=%%100)*60+1!%%100)-((((10!TS:%CS%=%%100)*60+1!%%100)" & set/A "T=!T:-=8640000-!"
set/A "cc=T%%100+100,T/=100,ss=T%%60+100,T/=60,mm=T%%60+100,hh=T/60+100"
set "value=!hh:~1!%CE%!mm:~1!%CE%!ss:~1!%DE%!cc:~1!" & if "%~2"=="" echo/!value!
endlocal & set "timer_end=%value%" & set "timer_set=" & goto :eof

How to scroll to top of long ScrollView layout?

Had the same issue, probably some kind of bug.

Even the fullScroll(ScrollView.FOCUS_UP) from the other answer didn't work.
Only thing that worked for me was calling scroll_view.smoothScrollTo(0,0) right after the dialog is shown.

How do I correct the character encoding of a file?

On OS X Synalyze It! lets you display parts of your file in different encodings (all which are supported by the ICU library). Once you know what's the source encoding you can copy the whole file (bytes) via clipboard and insert into a new document where the target encoding (UTF-8 or whatever you like) is selected.

Very helpful when working with UTF-8 or other Unicode representations is UnicodeChecker

#define macro for debug printing in C?

So, when using gcc, I like:

#define DBGI(expr) ({int g2rE3=expr; fprintf(stderr, "%s:%d:%s(): ""%s->%i\n", __FILE__,  __LINE__, __func__, #expr, g2rE3); g2rE3;})

Because it can be inserted into code.

Suppose you're trying to debug

printf("%i\n", (1*2*3*4*5*6));

720

Then you can change it to:

printf("%i\n", DBGI(1*2*3*4*5*6));

hello.c:86:main(): 1*2*3*4*5*6->720
720

And you can get an analysis of what expression was evaluated to what.

It's protected against the double-evaluation problem, but the absence of gensyms does leave it open to name-collisions.

However it does nest:

DBGI(printf("%i\n", DBGI(1*2*3*4*5*6)));

hello.c:86:main(): 1*2*3*4*5*6->720
720
hello.c:86:main(): printf("%i\n", DBGI(1*2*3*4*5*6))->4

So I think that as long as you avoid using g2rE3 as a variable name, you'll be OK.

Certainly I've found it (and allied versions for strings, and versions for debug levels etc) invaluable.

Multiple line comment in Python

Try this

'''
This is a multiline
comment. I can type here whatever I want.
'''

Python does have a multiline string/comment syntax in the sense that unless used as docstrings, multiline strings generate no bytecode -- just like #-prepended comments. In effect, it acts exactly like a comment.

On the other hand, if you say this behavior must be documented in the official docs to be a true comment syntax, then yes, you would be right to say it is not guaranteed as part of the language specification.

In any case your editor should also be able to easily comment-out a selected region (by placing a # in front of each line individually). If not, switch to an editor that does.

Programming in Python without certain text editing features can be a painful experience. Finding the right editor (and knowing how to use it) can make a big difference in how the Python programming experience is perceived.

Not only should the editor be able to comment-out selected regions, it should also be able to shift blocks of code to the left and right easily, and should automatically place the cursor at the current indentation level when you press Enter. Code folding can also be useful.

HorizontalScrollView within ScrollView Touch Handling

Neevek's solution works better than Joel's on devices running 3.2 and above. There is a bug in Android that will cause java.lang.IllegalArgumentException: pointerIndex out of range if a gesture detector is used inside a scollview. To duplicate the issue, implement a custom scollview as Joel suggested and put a view pager inside. If you drag (don't lift you figure) to one direction (left/right) and then to the opposite, you will see the crash. Also in Joel's solution, if you drag the view pager by moving your finger diagonally, once your finger leave the view pager's content view area, the pager will spring back to its previous position. All these issues are more to do with Android's internal design or lack of it than Joel's implementation, which itself is a piece of smart and concise code.

http://code.google.com/p/android/issues/detail?id=18990

Unable to load config info from /usr/local/ssl/openssl.cnf on Windows

With the GnuWin32 tools I found the openssl.cnf under C:\gnuwin32\share

set OPENSSL_CONF=C:\gnuwin32\share\openssl.cnf

How can two strings be concatenated?

As others have pointed out, paste() is the way to go. But it can get annoying to have to type paste(str1, str2, str3, sep='') everytime you want the non-default separator.

You can very easily create wrapper functions that make life much simpler. For instance, if you find yourself concatenating strings with no separator really often, you can do:

p <- function(..., sep='') {
    paste(..., sep=sep, collapse=sep)
}

or if you often want to join strings from a vector (like implode() from PHP):

implode <- function(..., sep='') {
     paste(..., collapse=sep)
}

Allows you do do this:

p('a', 'b', 'c')
#[1] "abc"
vec <- c('a', 'b', 'c')
implode(vec)
#[1] "abc"
implode(vec, sep=', ')
#[1] "a, b, c"

Also, there is the built-in paste0, which does the same thing as my implode, but without allowing custom separators. It's slightly more efficient than paste().

How do I change an HTML selected option using JavaScript?

mySelect.value = myValue;

Where mySelect is your selection box, and myValue is the value you want to change it to.

Understanding dispatch_async

All of the DISPATCH_QUEUE_PRIORITY_X queues are concurrent queues (meaning they can execute multiple tasks at once), and are FIFO in the sense that tasks within a given queue will begin executing using "first in, first out" order. This is in comparison to the main queue (from dispatch_get_main_queue()), which is a serial queue (tasks will begin executing and finish executing in the order in which they are received).

So, if you send 1000 dispatch_async() blocks to DISPATCH_QUEUE_PRIORITY_DEFAULT, those tasks will start executing in the order you sent them into the queue. Likewise for the HIGH, LOW, and BACKGROUND queues. Anything you send into any of these queues is executed in the background on alternate threads, away from your main application thread. Therefore, these queues are suitable for executing tasks such as background downloading, compression, computation, etc.

Note that the order of execution is FIFO on a per-queue basis. So if you send 1000 dispatch_async() tasks to the four different concurrent queues, evenly splitting them and sending them to BACKGROUND, LOW, DEFAULT and HIGH in order (ie you schedule the last 250 tasks on the HIGH queue), it's very likely that the first tasks you see starting will be on that HIGH queue as the system has taken your implication that those tasks need to get to the CPU as quickly as possible.

Note also that I say "will begin executing in order", but keep in mind that as concurrent queues things won't necessarily FINISH executing in order depending on length of time for each task.

As per Apple:

https://developer.apple.com/library/content/documentation/General/Conceptual/ConcurrencyProgrammingGuide/OperationQueues/OperationQueues.html

A concurrent dispatch queue is useful when you have multiple tasks that can run in parallel. A concurrent queue is still a queue in that it dequeues tasks in a first-in, first-out order; however, a concurrent queue may dequeue additional tasks before any previous tasks finish. The actual number of tasks executed by a concurrent queue at any given moment is variable and can change dynamically as conditions in your application change. Many factors affect the number of tasks executed by the concurrent queues, including the number of available cores, the amount of work being done by other processes, and the number and priority of tasks in other serial dispatch queues.

Basically, if you send those 1000 dispatch_async() blocks to a DEFAULT, HIGH, LOW, or BACKGROUND queue they will all start executing in the order you send them. However, shorter tasks may finish before longer ones. Reasons behind this are if there are available CPU cores or if the current queue tasks are performing computationally non-intensive work (thus making the system think it can dispatch additional tasks in parallel regardless of core count).

The level of concurrency is handled entirely by the system and is based on system load and other internally determined factors. This is the beauty of Grand Central Dispatch (the dispatch_async() system) - you just make your work units as code blocks, set a priority for them (based on the queue you choose) and let the system handle the rest.

So to answer your above question: you are partially correct. You are "asking that code" to perform concurrent tasks on a global concurrent queue at the specified priority level. The code in the block will execute in the background and any additional (similar) code will execute potentially in parallel depending on the system's assessment of available resources.

The "main" queue on the other hand (from dispatch_get_main_queue()) is a serial queue (not concurrent). Tasks sent to the main queue will always execute in order and will always finish in order. These tasks will also be executed on the UI Thread so it's suitable for updating your UI with progress messages, completion notifications, etc.

How to check a string for specific characters?

Quick comparison of timings in response to the post by Abbafei:

import timeit

def func1():
    phrase = 'Lucky Dog'
    return any(i in 'LD' for i in phrase)

def func2():
    phrase = 'Lucky Dog'
    if ('L' in phrase) or ('D' in phrase):
        return True
    else:
        return False

if __name__ == '__main__': 
    func1_time = timeit.timeit(func1, number=100000)
    func2_time = timeit.timeit(func2, number=100000)
    print('Func1 Time: {0}\nFunc2 Time: {1}'.format(func1_time, func2_time))

Output:

Func1 Time: 0.0737484362111
Func2 Time: 0.0125144964371

So the code is more compact with any, but faster with the conditional.


EDIT : TL;DR -- For long strings, if-then is still much faster than any!

I decided to compare the timing for a long random string based on some of the valid points raised in the comments:

# Tested in Python 2.7.14

import timeit
from string import ascii_letters
from random import choice

def create_random_string(length=1000):
    random_list = [choice(ascii_letters) for x in range(length)]
    return ''.join(random_list)

def function_using_any(phrase):
    return any(i in 'LD' for i in phrase)

def function_using_if_then(phrase):
    if ('L' in phrase) or ('D' in phrase):
        return True
    else:
        return False

if __name__ == '__main__':
    random_string = create_random_string(length=2000)
    func1_time = timeit.timeit(stmt="function_using_any(random_string)",
                               setup="from __main__ import function_using_any, random_string",
                               number=200000)
    func2_time = timeit.timeit(stmt="function_using_if_then(random_string)",
                               setup="from __main__ import function_using_if_then, random_string",
                               number=200000)
    print('Time for function using any: {0}\nTime for function using if-then: {1}'.format(func1_time, func2_time))

Output:

Time for function using any: 0.1342546
Time for function using if-then: 0.0201827

If-then is almost an order of magnitude faster than any!

Changing website favicon dynamically

There is a single line solution for those who use jQuery:

$("link[rel*='icon']").prop("href",'https://www.stackoverflow.com/favicon.ico');

pinpointing "conditional jump or move depends on uninitialized value(s)" valgrind message

What this means is that you are trying to print out/output a value which is at least partially uninitialized. Can you narrow it down so that you know exactly what value that is? After that, trace through your code to see where it is being initialized. Chances are, you will see that it is not being fully initialized.

If you need more help, posting the relevant sections of source code might allow someone to offer more guidance.

EDIT

I see you've found the problem. Note that valgrind watches for Conditional jump or move based on unitialized variables. What that means is that it will only give out a warning if the execution of the program is altered due to the uninitialized value (ie. the program takes a different branch in an if statement, for example). Since the actual arithmetic did not involve a conditional jump or move, valgrind did not warn you of that. Instead, it propagated the "uninitialized" status to the result of the statement that used it.

It may seem counterintuitive that it does not warn you immediately, but as mark4o pointed out, it does this because uninitialized values get used in C all the time (examples: padding in structures, the realloc() call, etc.) so those warnings would not be very useful due to the false positive frequency.

UIImage: Resize, then Crop

An older post contains code for a method to resize your UIImage. The relevant portion is as follows:

+ (UIImage*)imageWithImage:(UIImage*)image 
               scaledToSize:(CGSize)newSize;
{
   UIGraphicsBeginImageContext( newSize );
   [image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];
   UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
   UIGraphicsEndImageContext();

   return newImage;
}

As far as cropping goes, I believe that if you alter the method to use a different size for the scaling than for the context, your resulting image should be clipped to the bounds of the context.

What is TypeScript and why would I use it in place of JavaScript?

I originally wrote this answer when TypeScript was still hot-off-the-presses. Five years later, this is an OK overview, but look at Lodewijk's answer below for more depth

1000ft view...

TypeScript is a superset of JavaScript which primarily provides optional static typing, classes and interfaces. One of the big benefits is to enable IDEs to provide a richer environment for spotting common errors as you type the code.

To get an idea of what I mean, watch Microsoft's introductory video on the language.

For a large JavaScript project, adopting TypeScript might result in more robust software, while still being deployable where a regular JavaScript application would run.

It is open source, but you only get the clever Intellisense as you type if you use a supported IDE. Initially, this was only Microsoft's Visual Studio (also noted in blog post from Miguel de Icaza). These days, other IDEs offer TypeScript support too.

Are there other technologies like it?

There's CoffeeScript, but that really serves a different purpose. IMHO, CoffeeScript provides readability for humans, but TypeScript also provides deep readability for tools through its optional static typing (see this recent blog post for a little more critique). There's also Dart but that's a full on replacement for JavaScript (though it can produce JavaScript code)

Example

As an example, here's some TypeScript (you can play with this in the TypeScript Playground)

class Greeter {
    greeting: string;
    constructor (message: string) {
        this.greeting = message;
    }
    greet() {
        return "Hello, " + this.greeting;
    }
}  

And here's the JavaScript it would produce

var Greeter = (function () {
    function Greeter(message) {
        this.greeting = message;
    }
    Greeter.prototype.greet = function () {
        return "Hello, " + this.greeting;
    };
    return Greeter;
})();

Notice how the TypeScript defines the type of member variables and class method parameters. This is removed when translating to JavaScript, but used by the IDE and compiler to spot errors, like passing a numeric type to the constructor.

It's also capable of inferring types which aren't explicitly declared, for example, it would determine the greet() method returns a string.

Debugging TypeScript

Many browsers and IDEs offer direct debugging support through sourcemaps. See this Stack Overflow question for more details: Debugging TypeScript code with Visual Studio

Want to know more?

I originally wrote this answer when TypeScript was still hot-off-the-presses. Check out Lodewijk's answer to this question for some more current detail.

Matplotlib discrete colorbar

I think you'd want to look at colors.ListedColormap to generate your colormap, or if you just need a static colormap I've been working on an app that might help.

Attaching click event to a JQuery object not yet added to the DOM

Try this.... Replace body with parent selector

$('body').on('click', '#my-button', function () {
    console.log("yeahhhh!!! but this doesn't work for me :(");
});

How do I convert a String to a BigInteger?

Using the constructor

BigInteger(String val)

Translates the decimal String representation of a BigInteger into a BigInteger.

Javadoc

How to delete duplicate rows in SQL Server?

Deleting duplicates from a huge(several millions of records) table might take long time . I suggest that you do a bulk insert into a temp table of the selected rows rather than deleting.

--REWRITING YOUR CODE(TAKE NOTE OF THE 3RD LINE) WITH CTE AS(SELECT NAME,ROW_NUMBER() 
OVER (PARTITION BY NAME ORDER BY NAME) ID FROM @TB) SELECT * INTO #unique_records FROM 
CTE WHERE ID =1;

How to use log levels in java

The use of levels is really up tp you. You need to decide what is severe in your application, what is a warning and what is just information. You need to split your logging so that your users can easily set up a level of logging that doesn't kill the system with excessing IO but which will report serious errors so you can fix them.

How to remove word wrap from textarea?

This question seems to be the most popular one for disabling textarea wrap. However, as of April 2017 I find that IE 11 (11.0.9600) will not disable word wrap with any of the above solutions.

The only solution which does work for IE 11 is wrap="off". wrap="soft" and/or the various CSS attributes like white-space: pre alter where IE 11 chooses to wrap but it still wraps somewhere. Note that I have tested this with or without Compatibility View. IE 11 is pretty HTML 5 compatible, but not in this case.

Thus, to achieve lines which retain their whitespace and go off the right-hand side I am using:

<textarea style="white-space: pre; overflow: scroll;" wrap="off">

Fortuitously this does seem to work in Chrome & Firefox too. I am not defending the use of pre-HTML 5 wrap="off", just saying that it seems to be required for IE 11.

JSON Post with Customized HTTPHeader Field

I tried as you mentioned, but only first parameter is going through and rest all are appearing in the server as undefined. I am passing JSONWebToken as part of header.

.ajax({
    url: 'api/outletadd',
    type: 'post',
    data: { outletname:outletname , addressA:addressA , addressB:addressB, city:city , postcode:postcode , state:state , country:country , menuid:menuid },
    headers: {
        authorization: storedJWT
    },
    dataType: 'json',
    success: function (data){
        alert("Outlet Created");
    },
    error: function (data){
        alert("Outlet Creation Failed, please try again.");        
    }

    });

database vs. flat files

SQL ad hoc query abilities are enough of a reason for me. With a good schema and indexing on the tables, this is fast and effective and will have good performance.

How to len(generator())

You can use len(list(generator_function()). However, this consumes the generator, but that's the only way you can find out how many elements are generated. So you may want to save the list somewhere if you also want to use the items.

a = list(generator_function())
print(len(a))
print(a[0])

Round up to Second Decimal Place in Python

The round funtion stated does not works for definate integers like :

a=8
round(a,3)
8.0
a=8.00
round(a,3)
8.0
a=8.000000000000000000000000
round(a,3)
8.0

but , works for :

r=400/3.0
r
133.33333333333334
round(r,3)
133.333

Morever the decimals like 2.675 are rounded as 2.67 not 2.68.
Better use the other method provided above.

What is a good regular expression to match a URL?

Another possible solution, above solution failed for me in parsing query string params.

var regex = new RegExp("^(http[s]?:\\/\\/(www\\.)?|ftp:\\/\\/(www\\.)?|www\\.){1}([0-9A-Za-z-\\.@:%_\+~#=]+)+((\\.[a-zA-Z]{2,3})+)(/(.)*)?(\\?(.)*)?");

if(regex.test("http://google.com")){
  alert("Successful match");
}else{
  alert("No match");
}

In this solution please feel free to modify [-0-9A-Za-z\.@:%_\+~#=, to match the domain/sub domain name. In this solution query string parameters are also taken care.

If you are not using RegEx, then from the expression replace \\ by \.

Hope this helps.

Should import statements always be at the top of a module?

Curt makes a good point: the second version is clearer and will fail at load time rather than later, and unexpectedly.

Normally I don't worry about the efficiency of loading modules, since it's (a) pretty fast, and (b) mostly only happens at startup.

If you have to load heavyweight modules at unexpected times, it probably makes more sense to load them dynamically with the __import__ function, and be sure to catch ImportError exceptions, and handle them in a reasonable manner.

What exactly is RESTful programming?

RESTful programming is about:

  • resources being identified by a persistent identifier: URIs are the ubiquitous choice of identifier these days
  • resources being manipulated using a common set of verbs: HTTP methods are the commonly seen case - the venerable Create, Retrieve, Update, Delete becomes POST, GET, PUT, and DELETE. But REST is not limited to HTTP, it is just the most commonly used transport right now.
  • the actual representation retrieved for a resource is dependent on the request and not the identifier: use Accept headers to control whether you want XML, HTTP, or even a Java Object representing the resource
  • maintaining the state in the object and representing the state in the representation
  • representing the relationships between resources in the representation of the resource: the links between objects are embedded directly in the representation
  • resource representations describe how the representation can be used and under what circumstances it should be discarded/refetched in a consistent manner: usage of HTTP Cache-Control headers

The last one is probably the most important in terms of consequences and overall effectiveness of REST. Overall, most of the RESTful discussions seem to center on HTTP and its usage from a browser and what not. I understand that R. Fielding coined the term when he described the architecture and decisions that lead to HTTP. His thesis is more about the architecture and cache-ability of resources than it is about HTTP.

If you are really interested in what a RESTful architecture is and why it works, read his thesis a few times and read the whole thing not just Chapter 5! Next look into why DNS works. Read about the hierarchical organization of DNS and how referrals work. Then read and consider how DNS caching works. Finally, read the HTTP specifications (RFC2616 and RFC3040 in particular) and consider how and why the caching works the way that it does. Eventually, it will just click. The final revelation for me was when I saw the similarity between DNS and HTTP. After this, understanding why SOA and Message Passing Interfaces are scalable starts to click.

I think that the most important trick to understanding the architectural importance and performance implications of a RESTful and Shared Nothing architectures is to avoid getting hung up on the technology and implementation details. Concentrate on who owns resources, who is responsible for creating/maintaining them, etc. Then think about the representations, protocols, and technologies.

How do I clear all variables in the middle of a Python script?

The following sequence of commands does remove every name from the current module:

>>> import sys
>>> sys.modules[__name__].__dict__.clear()

I doubt you actually DO want to do this, because "every name" includes all built-ins, so there's not much you can do after such a total wipe-out. Remember, in Python there is really no such thing as a "variable" -- there are objects, of many kinds (including modules, functions, class, numbers, strings, ...), and there are names, bound to objects; what the sequence does is remove every name from a module (the corresponding objects go away if and only if every reference to them has just been removed).

Maybe you want to be more selective, but it's hard to guess exactly what you mean unless you want to be more specific. But, just to give an example:

>>> import sys
>>> this = sys.modules[__name__]
>>> for n in dir():
...   if n[0]!='_': delattr(this, n)
... 
>>>

This sequence leaves alone names that are private or magical, including the __builtins__ special name which houses all built-in names. So, built-ins still work -- for example:

>>> dir()
['__builtins__', '__doc__', '__name__', '__package__', 'n']
>>> 

As you see, name n (the control variable in that for) also happens to stick around (as it's re-bound in the for clause every time through), so it might be better to name that control variable _, for example, to clearly show "it's special" (plus, in the interactive interpreter, name _ is re-bound anyway after every complete expression entered at the prompt, to the value of that expression, so it won't stick around for long;-).

Anyway, once you have determined exactly what it is you want to do, it's not hard to define a function for the purpose and put it in your start-up file (if you want it only in interactive sessions) or site-customize file (if you want it in every script).

Why is the <center> tag deprecated in HTML?

According to W3Schools.com,

The center element was deprecated in HTML 4.01, and is not supported in XHTML 1.0 Strict DTD.

The HTML 4.01 spec gives this reason for deprecating the tag:

The CENTER element is exactly equivalent to specifying the DIV element with the align attribute set to "center".

How to get the index with the key in Python dictionary?

Use OrderedDicts: http://docs.python.org/2/library/collections.html#collections.OrderedDict

>>> x = OrderedDict((("a", "1"), ("c", '3'), ("b", "2")))
>>> x["d"] = 4
>>> x.keys().index("d")
3
>>> x.keys().index("c")
1

For those using Python 3

>>> list(x.keys()).index("c")
1

Bind TextBox on Enter-key press

Answered here quite elegantly using attached behaviors, my preferred method for almost anything.

WPF how to make textbox lose focus after hitting enter

String method cannot be found in a main class method

It seem like your Resort method doesn't declare a compareTo method. This method typically belongs to the Comparable interface. Make sure your class implements it.

Additionally, the compareTo method is typically implemented as accepting an argument of the same type as the object the method gets invoked on. As such, you shouldn't be passing a String argument, but rather a Resort.

Alternatively, you can compare the names of the resorts. For example

if (resortList[mid].getResortName().compareTo(resortName)>0)  

How to increase editor font size?

You can try to search in preferences (android studio IDE > preferences). In aptana studio it works like this making smaller: CMD and -, use CMD shift and =. Works?

Writing BMP image in pure c/c++ without other libraries

Here is a C++ variant of the code that works for me. Note I had to change the size computation to account for the line padding.

// mimeType = "image/bmp";

unsigned char file[14] = {
    'B','M', // magic
    0,0,0,0, // size in bytes
    0,0, // app data
    0,0, // app data
    40+14,0,0,0 // start of data offset
};
unsigned char info[40] = {
    40,0,0,0, // info hd size
    0,0,0,0, // width
    0,0,0,0, // heigth
    1,0, // number color planes
    24,0, // bits per pixel
    0,0,0,0, // compression is none
    0,0,0,0, // image bits size
    0x13,0x0B,0,0, // horz resoluition in pixel / m
    0x13,0x0B,0,0, // vert resolutions (0x03C3 = 96 dpi, 0x0B13 = 72 dpi)
    0,0,0,0, // #colors in pallete
    0,0,0,0, // #important colors
    };

int w=waterfallWidth;
int h=waterfallHeight;

int padSize  = (4-(w*3)%4)%4;
int sizeData = w*h*3 + h*padSize;
int sizeAll  = sizeData + sizeof(file) + sizeof(info);

file[ 2] = (unsigned char)( sizeAll    );
file[ 3] = (unsigned char)( sizeAll>> 8);
file[ 4] = (unsigned char)( sizeAll>>16);
file[ 5] = (unsigned char)( sizeAll>>24);

info[ 4] = (unsigned char)( w   );
info[ 5] = (unsigned char)( w>> 8);
info[ 6] = (unsigned char)( w>>16);
info[ 7] = (unsigned char)( w>>24);

info[ 8] = (unsigned char)( h    );
info[ 9] = (unsigned char)( h>> 8);
info[10] = (unsigned char)( h>>16);
info[11] = (unsigned char)( h>>24);

info[20] = (unsigned char)( sizeData    );
info[21] = (unsigned char)( sizeData>> 8);
info[22] = (unsigned char)( sizeData>>16);
info[23] = (unsigned char)( sizeData>>24);

stream.write( (char*)file, sizeof(file) );
stream.write( (char*)info, sizeof(info) );

unsigned char pad[3] = {0,0,0};

for ( int y=0; y<h; y++ )
{
    for ( int x=0; x<w; x++ )
    {
        long red = lround( 255.0 * waterfall[x][y] );
        if ( red < 0 ) red=0;
        if ( red > 255 ) red=255;
        long green = red;
        long blue = red;

        unsigned char pixel[3];
        pixel[0] = blue;
        pixel[1] = green;
        pixel[2] = red;

        stream.write( (char*)pixel, 3 );
    }
    stream.write( (char*)pad, padSize );
}

Get the current year in JavaScript

You can simply use javascript like this. Otherwise you can use momentJs Plugin which helps in large application.

new Date().getDate()          // Get the day as a number (1-31)
new Date().getDay()           // Get the weekday as a number (0-6)
new Date().getFullYear()      // Get the four digit year (yyyy)
new Date().getHours()         // Get the hour (0-23)
new Date().getMilliseconds()  // Get the milliseconds (0-999)
new Date().getMinutes()       // Get the minutes (0-59)
new Date().getMonth()         // Get the month (0-11)
new Date().getSeconds()       // Get the seconds (0-59)
new Date().getTime()          // Get the time (milliseconds since January 1, 1970)

_x000D_
_x000D_
function generate(type,element)_x000D_
{_x000D_
 var value = "";_x000D_
 var date = new Date();_x000D_
 switch (type) {_x000D_
  case "Date":_x000D_
   value = date.getDate();  // Get the day as a number (1-31)_x000D_
   break;_x000D_
  case "Day":_x000D_
   value = date.getDay();  // Get the weekday as a number (0-6)_x000D_
   break;_x000D_
  case "FullYear":_x000D_
   value = date.getFullYear(); // Get the four digit year (yyyy)_x000D_
   break;_x000D_
  case "Hours":_x000D_
   value = date.getHours(); // Get the hour (0-23)_x000D_
   break;_x000D_
  case "Milliseconds":_x000D_
   value = date.getMilliseconds(); // Get the milliseconds (0-999)_x000D_
   break;_x000D_
  case "Minutes":_x000D_
   value = date.getMinutes();     // Get the minutes (0-59)_x000D_
   break;_x000D_
  case "Month":_x000D_
   value = date.getMonth(); // Get the month (0-11)_x000D_
   break;_x000D_
  case "Seconds":_x000D_
   value = date.getSeconds(); // Get the seconds (0-59)_x000D_
   break;_x000D_
  case "Time":_x000D_
   value = date.getTime();  // Get the time (milliseconds since January 1, 1970)_x000D_
   break;_x000D_
 }_x000D_
_x000D_
 $(element).siblings('span').text(value);_x000D_
}
_x000D_
li{_x000D_
  list-style-type: none;_x000D_
  padding: 5px;_x000D_
}_x000D_
_x000D_
button{_x000D_
  width: 150px;_x000D_
}_x000D_
_x000D_
span{_x000D_
  margin-left: 100px;_x000D_
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
_x000D_
_x000D_
<ul>_x000D_
 <li>_x000D_
  <button type="button" onclick="generate('Date',this)">Get Date</button>_x000D_
  <span></span>_x000D_
 </li>_x000D_
 <li>_x000D_
  <button type="button" onclick="generate('Day',this)">Get Day</button>_x000D_
  <span></span>_x000D_
 </li>_x000D_
 <li>_x000D_
  <button type="button" onclick="generate('FullYear',this)">Get Full Year</button>_x000D_
  <span></span>_x000D_
 </li>_x000D_
 <li>_x000D_
  <button type="button" onclick="generate('Hours',this)">Get Hours</button>_x000D_
  <span></span>_x000D_
 </li>_x000D_
 <li>_x000D_
  <button type="button" onclick="generate('Milliseconds',this)">Get Milliseconds</button>_x000D_
  <span></span>_x000D_
 </li>_x000D_
_x000D_
 <li>_x000D_
  <button type="button" onclick="generate('Minutes',this)">Get Minutes</button>_x000D_
  <span></span>_x000D_
 </li>_x000D_
 <li>_x000D_
  <button type="button" onclick="generate('Month',this)">Get Month</button>_x000D_
  <span></span>_x000D_
 </li>_x000D_
 <li>_x000D_
  <button type="button" onclick="generate('Seconds',this)">Get Seconds</button>_x000D_
  <span></span>_x000D_
 </li>_x000D_
 <li>_x000D_
  <button type="button" onclick="generate('Time',this)">Get Time</button>_x000D_
  <span></span>_x000D_
 </li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

text box input height

If you want to increase the height of the input field, you can specify line-height css property for the input field.

input {
    line-height: 2em; // 2em is (2 * default line height)
}

No resource found that matches the given name '@style/ Theme.Holo.Light.DarkActionBar'

You can change this one parent attribute ="android:style/Theme.Holo.Light.DarkActionBar"

Run script with rc.local: script works, but not at boot

if you are using linux on cloud, then usually you don't have chance to touch the real hardware using your hands. so you don't see the configuration interface when booting for the first time, and of course cannot configure it. As a result, the firstboot service will always be in the way to rc.local. The solution is to disable firstboot by doing:

sudo chkconfig firstboot off

if you are not sure why your rc.local does not run, you can always check from /etc/rc.d/rc file because this file will always run and call other subsystems (e.g. rc.local).

How to format Joda-Time DateTime to only mm/dd/yyyy?

I am adding this here even though the other answers are completely acceptable. JodaTime has parsers pre built in DateTimeFormat:

dateTime.toString(DateTimeFormat.longDate());

This is most of the options printed out with their format:

shortDate:         11/3/16
shortDateTime:     11/3/16 4:25 AM
mediumDate:        Nov 3, 2016
mediumDateTime:    Nov 3, 2016 4:25:35 AM
longDate:          November 3, 2016
longDateTime:      November 3, 2016 4:25:35 AM MDT
fullDate:          Thursday, November 3, 2016
fullDateTime:      Thursday, November 3, 2016 4:25:35 AM Mountain Daylight Time

Split a string into an array of strings based on a delimiter

You can use StrUtils.SplitString.

function SplitString(const S, Delimiters: string): TStringDynArray;

Its description from the documentation:

Splits a string into different parts delimited by the specified delimiter characters.

SplitString splits a string into different parts delimited by the specified delimiter characters. S is the string to be split. Delimiters is a string containing the characters defined as delimiters.

SplitString returns an array of strings of type System.Types.TStringDynArray that contains the split parts of the original string.

SQL JOIN, GROUP BY on three tables to get totals

I know this is late, but it does answer your original question.

/*Read the comments the same way that SQL runs the query
    1) FROM 
    2) GROUP 
    3) SELECT 
    4) My final notes at the bottom 
*/
SELECT 
        list.invoiceid
    ,   cust.customernumber 
    ,   MAX(list.inv_amount) AS invoice_amount/* we select the max because it will be the same for each payment to that invoice (presumably invoice amounts do not vary based on payment) */
    ,   MAX(list.inv_amount) - SUM(list.pay_amount)  AS [amount_due]
FROM 
Customers AS cust 
    INNER JOIN 
Payments  AS pay 
    ON 
        pay.customerid = cust.customerid
INNER JOIN  (   /* generate a list of payment_ids, their amounts, and the totals of the invoices they billed to*/
    SELECT 
            inpay.paymentid AS paymentid
        ,   inv.invoiceid AS invoiceid 
        ,   inv.amount  AS inv_amount 
        ,   pay.amount AS pay_amount 
    FROM 
    InvoicePayments AS inpay
        INNER JOIN 
    Invoices AS inv 
        ON  inv.invoiceid = inpay.invoiceid 
        INNER JOIN 
    Payments AS pay 
        ON pay.paymentid = inpay.paymentid
    )  AS list
ON 
    list.paymentid = pay.paymentid
    /* so at this point my result set would look like: 
    -- All my customers (crossed by) every paymentid they are associated to (I'll call this A)
    -- Every invoice payment and its association to: its own ammount, the total invoice ammount, its own paymentid (what I call list) 
    -- Filter out all records in A that do not have a paymentid matching in (list)
     -- we filter the result because there may be payments that did not go towards invoices!
 */
GROUP BY
    /* we want a record line for each customer and invoice ( or basically each invoice but i believe this makes more sense logically */ 
        cust.customernumber 
    ,   list.invoiceid 
/*
    -- we can improve this query by only hitting the Payments table once by moving it inside of our list subquery, 
    -- but this is what made sense to me when I was planning. 
    -- Hopefully it makes it clearer how the thought process works to leave it in there
    -- as several people have already pointed out, the data structure of the DB prevents us from looking at customers with invoices that have no payments towards them.
*/

How to generate the "create table" sql statement for an existing table in postgreSQL

My solution is to log in to the postgres db using psql with the -E option as follows:

psql -E -U username -d database   

In psql, run the following commands to see the sql that postgres uses to generate
the describe table statement:

-- List all tables in the schema (my example schema name is public)
\dt public.*
-- Choose a table name from above
-- For create table of one public.tablename
\d+ public.tablename  

Based on the sql echoed out after running these describe commands, I was able to put together
the following plpgsql function:

CREATE OR REPLACE FUNCTION generate_create_table_statement(p_table_name varchar)
  RETURNS text AS
$BODY$
DECLARE
    v_table_ddl   text;
    column_record record;
BEGIN
    FOR column_record IN 
        SELECT 
            b.nspname as schema_name,
            b.relname as table_name,
            a.attname as column_name,
            pg_catalog.format_type(a.atttypid, a.atttypmod) as column_type,
            CASE WHEN 
                (SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)
                 FROM pg_catalog.pg_attrdef d
                 WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef) IS NOT NULL THEN
                'DEFAULT '|| (SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)
                              FROM pg_catalog.pg_attrdef d
                              WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef)
            ELSE
                ''
            END as column_default_value,
            CASE WHEN a.attnotnull = true THEN 
                'NOT NULL'
            ELSE
                'NULL'
            END as column_not_null,
            a.attnum as attnum,
            e.max_attnum as max_attnum
        FROM 
            pg_catalog.pg_attribute a
            INNER JOIN 
             (SELECT c.oid,
                n.nspname,
                c.relname
              FROM pg_catalog.pg_class c
                   LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
              WHERE c.relname ~ ('^('||p_table_name||')$')
                AND pg_catalog.pg_table_is_visible(c.oid)
              ORDER BY 2, 3) b
            ON a.attrelid = b.oid
            INNER JOIN 
             (SELECT 
                  a.attrelid,
                  max(a.attnum) as max_attnum
              FROM pg_catalog.pg_attribute a
              WHERE a.attnum > 0 
                AND NOT a.attisdropped
              GROUP BY a.attrelid) e
            ON a.attrelid=e.attrelid
        WHERE a.attnum > 0 
          AND NOT a.attisdropped
        ORDER BY a.attnum
    LOOP
        IF column_record.attnum = 1 THEN
            v_table_ddl:='CREATE TABLE '||column_record.schema_name||'.'||column_record.table_name||' (';
        ELSE
            v_table_ddl:=v_table_ddl||',';
        END IF;

        IF column_record.attnum <= column_record.max_attnum THEN
            v_table_ddl:=v_table_ddl||chr(10)||
                     '    '||column_record.column_name||' '||column_record.column_type||' '||column_record.column_default_value||' '||column_record.column_not_null;
        END IF;
    END LOOP;

    v_table_ddl:=v_table_ddl||');';
    RETURN v_table_ddl;
END;
$BODY$
  LANGUAGE 'plpgsql' COST 100.0 SECURITY INVOKER;

Here is the function usage:

SELECT generate_create_table_statement('tablename');

And here is the drop statement if you don't want this function to persist permanently:

DROP FUNCTION generate_create_table_statement(p_table_name varchar);

How can I use JavaScript in Java?

I just wanted to answer something new for this question - J2V8.

Author Ian Bull says "Rhino and Nashorn are two common JavaScript runtimes, but these did not meet our requirements in a number of areas:

Neither support ‘Primitives‘. All interactions with these platforms require wrapper classes such as Integer, Double or Boolean. Nashorn is not supported on Android. Rhino compiler optimizations are not supported on Android. Neither engines support remote debugging on Android.""

Highly Efficient Java & JavaScript Integration

Github link

Compiler warning - suggest parentheses around assignment used as truth value

While that particular idiom is common, even more common is for people to use = when they mean ==. The convention when you really mean the = is to use an extra layer of parentheses:

while ((list = list->next)) { // yes, it's an assignment

xcode-select active developer directory error

  1. Download Xcode from App Store.

  2. Go to Xcode preferences/Locations/CommandlineTools

    You just have to set it to the Xcode version. It automatically points to '/Application/Xcode.app'

Mocking a function to raise an Exception to test an except block

Your mock is raising the exception just fine, but the error.resp.status value is missing. Rather than use return_value, just tell Mock that status is an attribute:

barMock.side_effect = HttpError(mock.Mock(status=404), 'not found')

Additional keyword arguments to Mock() are set as attributes on the resulting object.

I put your foo and bar definitions in a my_tests module, added in the HttpError class so I could use it too, and your test then can be ran to success:

>>> from my_tests import foo, HttpError
>>> import mock
>>> with mock.patch('my_tests.bar') as barMock:
...     barMock.side_effect = HttpError(mock.Mock(status=404), 'not found')
...     result = my_test.foo()
... 
404 - 
>>> result is None
True

You can even see the print '404 - %s' % error.message line run, but I think you wanted to use error.content there instead; that's the attribute HttpError() sets from the second argument, at any rate.

How to delete file from public folder in laravel 5.1

Update working for Laravel 8.x:

Deleting an image for example ->

First of all add the File Facade at the top of the controller:

use Illuminate\Support\Facades\File;

Then use delete function. If the file is in 'public/' you have to specify the path using public_path() function:

File::delete(public_path("images/filename.png"));

Install NuGet via PowerShell script

This also seems to do it. PS Example:

Install-PackageProvider -Name NuGet -MinimumVersion 2.8.5.201 -Force

Hash string in c#

The fastest way, to get a hash string for password store purposes, is a following code:

    internal static string GetStringSha256Hash(string text)
    {
        if (String.IsNullOrEmpty(text))
            return String.Empty;

        using (var sha = new System.Security.Cryptography.SHA256Managed())
        {
            byte[] textData = System.Text.Encoding.UTF8.GetBytes(text);
            byte[] hash = sha.ComputeHash(textData);
            return BitConverter.ToString(hash).Replace("-", String.Empty);
        }
    }

Remarks:

  • if the method is invoked often, the creation of sha variable should be refactored into a class field;
  • output is presented as encoded hex string;

In Angular, I need to search objects in an array

Your solutions are correct but unnecessary complicated. You can use pure javascript filter function. This is your model:

     $scope.fishes = [{category:'freshwater', id:'1', name: 'trout', more:'false'},  {category:'freshwater', id:'2', name:'bass', more:'false'}];

And this is your function:

     $scope.showdetails = function(fish_id){
         var found = $scope.fishes.filter({id : fish_id});
         return found;
     };

You can also use expression:

     $scope.showdetails = function(fish_id){
         var found = $scope.fishes.filter(function(fish){ return fish.id === fish_id });
         return found;
     };

More about this function: LINK

How to remove border of drop down list : CSS

select#xyz {
  border:0px;
  outline:0px;
}

Exact solution.

unable to set private key file: './cert.pem' type PEM

After reading cURL documentation on the options you used, it looks like the private key of certificate is not in the same file. If it is in different file, you need to mention it using --key file and supply passphrase.

So, please make sure that either cert.pem has private key (along with the certificate) or supply it using --key option.

Also, this documentation mentions that Note that this option assumes a "certificate" file that is the private key and the private certificate concatenated!

How they are concatenated? It is quite easy. Put them one after another in the same file.

You can get more help on this here.

I believe this might help you.

How to make a vertical line in HTML

In the Previous element after which you want to apply the vertical row , You can set CSS ...

border-right-width: thin;
border-right-color: black;
border-right-style: solid;

How to pass data to view in Laravel?

You can pass data to the view using the with method.

return View::make('blog')->with('posts', $posts);

video as site background? HTML 5

Take a look at my jquery videoBG plugin

http://syddev.com/jquery.videoBG/

Make any HTML5 video a site background... has an image fallback for browsers that don't support html5

Really easy to use

Let me know if you need any help.

Google MAP API v3: Center & Zoom on displayed markers

I've also find this fix that zooms to fit all markers

LatLngList: an array of instances of latLng, for example:

// "map" is an instance of GMap3

var LatLngList = [
                     new google.maps.LatLng (52.537,-2.061), 
                     new google.maps.LatLng (52.564,-2.017)
                 ],
    latlngbounds = new google.maps.LatLngBounds();

LatLngList.forEach(function(latLng){
   latlngbounds.extend(latLng);
});

// or with ES6:
// for( var latLng of LatLngList)
//    latlngbounds.extend(latLng);

map.setCenter(latlngbounds.getCenter());
map.fitBounds(latlngbounds); 

Incrementing in C++ - When to use x++ or ++x?

I just want to notice that the geneated code is offen the same if you use pre/post incrementation where the semantic (of pre/post) doesn't matter.

example:

pre.cpp:

#include <iostream>

int main()
{
  int i = 13;
  i++;
  for (; i < 42; i++)
    {
      std::cout << i << std::endl;
    }
}

post.cpp:

#include <iostream>

int main()
{

  int i = 13;
  ++i;
  for (; i < 42; ++i)
    {
      std::cout << i << std::endl;
    }
}

_

$> g++ -S pre.cpp
$> g++ -S post.cpp
$> diff pre.s post.s   
1c1
<   .file   "pre.cpp"
---
>   .file   "post.cpp"

Android: ProgressDialog.show() crashes with getApplicationContext

A dialog is always created and displayed as a part of an Activity. You need to pass in an Activity context instead of the Application context.

http://developer.android.com/guide/topics/ui/dialogs.html#ShowingADialog

outline on only one border

I like to give my input field a border, remove the outline on focus, and "outline" the border instead:

input {
  border: 1px solid grey;

  &:focus {
    outline: none;
    border-left: 1px solid violet;
  }
 }

You can also do it with a transparent border:

input {
  border: 1px solid transparent;

  &:focus {
    outline: none;
    border-left: 1px solid violet;
  }
 }

Dynamically load a JavaScript file

An absurd one-liner, for those who think that loading a js library shouldn't take more than one line of code :P

await new Promise((resolve, reject) => {let js = document.createElement("script"); js.src="mylibrary.js"; js.onload=resolve; js.onerror=reject; document.body.appendChild(js)});

Obviously if the script you want to import is a module, you can use the import(...) function.

How to solve "sign_and_send_pubkey: signing failed: agent refused operation"?

I need to share, as I spent too much time looking for a solution

Here was the solution : https://unix.stackexchange.com/a/351742/215375

I was using this command :

ssh-keygen -o -t rsa -b 4096 -C "[email protected]"

gnome-keyring does not support the generated key.

Removing the -o argument solved the problem.

Initialize array of strings

There is no right way, but you can initialize an array of literals:

char **values = (char *[]){"a", "b", "c"};

or you can allocate each and initialize it:

char **values = malloc(sizeof(char*) * s);
for(...)
{
    values[i] = malloc(sizeof(char) * l);
    //or
    values[i] = "hello";
}

pandas: best way to select all columns whose names start with X

Just perform a list comprehension to create your columns:

In [28]:

filter_col = [col for col in df if col.startswith('foo')]
filter_col
Out[28]:
['foo.aa', 'foo.bars', 'foo.fighters', 'foo.fox', 'foo.manchu']
In [29]:

df[filter_col]
Out[29]:
   foo.aa  foo.bars  foo.fighters  foo.fox foo.manchu
0     1.0         0             0        2         NA
1     2.1         0             1        4          0
2     NaN         0           NaN        1          0
3     4.7         0             0        0          0
4     5.6         0             0        0          0
5     6.8         1             0        5          0

Another method is to create a series from the columns and use the vectorised str method startswith:

In [33]:

df[df.columns[pd.Series(df.columns).str.startswith('foo')]]
Out[33]:
   foo.aa  foo.bars  foo.fighters  foo.fox foo.manchu
0     1.0         0             0        2         NA
1     2.1         0             1        4          0
2     NaN         0           NaN        1          0
3     4.7         0             0        0          0
4     5.6         0             0        0          0
5     6.8         1             0        5          0

In order to achieve what you want you need to add the following to filter the values that don't meet your ==1 criteria:

In [36]:

df[df[df.columns[pd.Series(df.columns).str.startswith('foo')]]==1]
Out[36]:
   bar.baz  foo.aa  foo.bars  foo.fighters  foo.fox foo.manchu nas.foo
0      NaN       1       NaN           NaN      NaN        NaN     NaN
1      NaN     NaN       NaN             1      NaN        NaN     NaN
2      NaN     NaN       NaN           NaN        1        NaN     NaN
3      NaN     NaN       NaN           NaN      NaN        NaN     NaN
4      NaN     NaN       NaN           NaN      NaN        NaN     NaN
5      NaN     NaN         1           NaN      NaN        NaN     NaN

EDIT

OK after seeing what you want the convoluted answer is this:

In [72]:

df.loc[df[df[df.columns[pd.Series(df.columns).str.startswith('foo')]] == 1].dropna(how='all', axis=0).index]
Out[72]:
   bar.baz  foo.aa  foo.bars  foo.fighters  foo.fox foo.manchu nas.foo
0      5.0     1.0         0             0        2         NA      NA
1      5.0     2.1         0             1        4          0       0
2      6.0     NaN         0           NaN        1          0       1
5      6.8     6.8         1             0        5          0       0

No resource identifier found for attribute '...' in package 'com.app....'

I just changed:

xmlns:app="http://schemas.android.com/apk/res-auto" 

to:

xmlns:app="http://schemas.android.com/apk/lib/com.app.chasebank"

and it stopped generating the errors, com.app.chasebank is the name of the package. It should work according to this Stack Overflow : No resource identifier found for attribute 'adSize' in package 'com.google.example' main.xml

How to quickly drop a user with existing privileges

I faced the same problem and now found a way to solve it. First you have to delete the database of the user that you wish to drop. Then the user can be easily deleted.

I created an user named "msf" and struggled a while to delete the user and recreate it. I followed the below steps and Got succeeded.

1) Drop the database

dropdb msf

2) drop the user

dropuser msf

Now I got the user successfully dropped.

How to validate phone number in laravel 5.2?

Use required|numeric|size:11 Instead of required|min:11|numeric

Does hosts file exist on the iPhone? How to change it?

In case anybody else falls onto this page, you can also solve this by using the Ip address in the URL request instead of the domain:

NSURL *myURL = [NSURL URLWithString:@"http://10.0.0.2/mypage.php"];

Then you specify the Host manually:

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:myURL];
[request setAllHTTPHeaderFields:[NSDictionary dictionaryWithObjectAndKeys:@"myserver",@"Host"]];

As far as the server is concerned, it will behave the exact same way as if you had used http://myserver/mypage.php, except that the iPhone will not have to do a DNS lookup.

100% Public API.

Base64 PNG data to HTML5 canvas

By the looks of it you need to actually pass drawImage an image object like so

_x000D_
_x000D_
var canvas = document.getElementById("c");_x000D_
var ctx = canvas.getContext("2d");_x000D_
_x000D_
var image = new Image();_x000D_
image.onload = function() {_x000D_
  ctx.drawImage(image, 0, 0);_x000D_
};_x000D_
image.src = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAIAAAACDbGyAAAAAXNSR0IArs4c6QAAAAlwSFlzAAALEwAACxMBAJqcGAAAAAd0SU1FB9oMCRUiMrIBQVkAAAAZdEVYdENvbW1lbnQAQ3JlYXRlZCB3aXRoIEdJTVBXgQ4XAAAADElEQVQI12NgoC4AAABQAAEiE+h1AAAAAElFTkSuQmCC";
_x000D_
<canvas id="c"></canvas>
_x000D_
_x000D_
_x000D_

I've tried it in chrome and it works fine.

How do I convert Long to byte[] and back in java

I find this method to be most friendly.

var b = BigInteger.valueOf(x).toByteArray();

var l = new BigInteger(b);

Metadata file '.dll' could not be found

Removing the packages folder containing NuGet in the solution folder worked for me. After rebuilding everything worked again. Check References in the solution and check for references that have a yellow triangle.

Example picture:

Enter image description here

Java: Literal percent sign in printf statement

Escaped percent sign is double percent (%%):

System.out.printf("2 out of 10 is %d%%", 20);

Can't access to HttpContext.Current

Have you included the System.Web assembly in the application?

using System.Web;

If not, try specifying the System.Web namespace, for example:

 System.Web.HttpContext.Current

Foreach Control in form, how can I do something to all the TextBoxes in my Form?

The trick here is that Controls is not a List<> or IEnumerable but a ControlCollection.

I recommend using an extension of Control that will return something more..queriyable ;)

public static IEnumerable<Control> All(this ControlCollection controls)
    {
        foreach (Control control in controls)
        {
            foreach (Control grandChild in control.Controls.All())
                yield return grandChild;

            yield return control;
        }
    }

Then you can do :

foreach(var textbox in this.Controls.All().OfType<TextBox>)
{
    // Apply logic to the textbox here
}

Swift how to sort array of custom objects by property value

If you are going to be sorting this array in more than one place, it may make sense to make your array type Comparable.

class MyImageType: Comparable, Printable {
    var fileID: Int

    // For Printable
    var description: String {
        get {
            return "ID: \(fileID)"
        }
    }

    init(fileID: Int) {
        self.fileID = fileID
    }
}

// For Comparable
func <(left: MyImageType, right: MyImageType) -> Bool {
    return left.fileID < right.fileID
}

// For Comparable
func ==(left: MyImageType, right: MyImageType) -> Bool {
    return left.fileID == right.fileID
}

let one = MyImageType(fileID: 1)
let two = MyImageType(fileID: 2)
let twoA = MyImageType(fileID: 2)
let three = MyImageType(fileID: 3)

let a1 = [one, three, two]

// return a sorted array
println(sorted(a1)) // "[ID: 1, ID: 2, ID: 3]"

var a2 = [two, one, twoA, three]

// sort the array 'in place'
sort(&a2)
println(a2) // "[ID: 1, ID: 2, ID: 2, ID: 3]"

Count cells that contain any text

COUNTIF function can count cell which specific condition where as COUNTA will count all cell which contain any value

Example: Function in A7: =COUNTA(A1:A6)

Range:

A1| a

A2| b

A3| banana

A4| 42

A5|

A6|

A7| 4 (result)

How do I stop Notepad++ from showing autocomplete for all words in the file

Notepad++ provides 2 types of features:

  • Auto-completion that read the open file and provide suggestion of words and/or functions within the file
  • Suggestion with the arguments of functions (specific to the language)

Based on what you write, it seems what you want is auto-completion on function only + suggestion on arguments.

To do that, you just need to change a setting.

  1. Go to Settings > Preferences... > Auto-completion
  2. Check Enable Auto-completion on each input
  3. Select Function completion and not Word completion
  4. Check Function parameter hint on input (if you have this option)

On version 6.5.5 of Notepad++, I have this setting settings

Some documentation about auto-completion is available in Notepad++ Wiki.

how to display employee names starting with a and then b in sql

select name_last, name_first
from employees
where name_last like 'A%' or name_last like 'B%'
order by name_last, name_first asc

Remove all multiple spaces in Javascript and replace with single space

you all forget about quantifier n{X,} http://www.w3schools.com/jsref/jsref_regexp_nxcomma.asp

here best solution

str = str.replace(/\s{2,}/g, ' ');

Align div right in Bootstrap 3

Add offset8 to your class, for example:

<div class="offset8">aligns to the right</div>

How to generate a Dockerfile from an image?

How to generate or reverse a Dockerfile from an image?

You can.

alias dfimage="docker run -v /var/run/docker.sock:/var/run/docker.sock --rm alpine/dfimage"
dfimage -sV=1.36 nginx:latest

It will pull the target docker image automaticlaly and export Dockerfile. Parameter -sV=1.36 is not always required.

Reference: https://hub.docker.com/repository/docker/alpine/dfimage

below is the old answer, it doesn't work any more.

$ docker pull centurylink/dockerfile-from-image
$ alias dfimage="docker run -v /var/run/docker.sock:/var/run/docker.sock --rm centurylink/dockerfile-from-image"
$ dfimage --help
Usage: dockerfile-from-image.rb [options] <image_id>
    -f, --full-tree                  Generate Dockerfile for all parent layers
    -h, --help                       Show this message

Why does scanf() need "%lf" for doubles, when printf() is okay with just "%f"?

scanf needs to know the size of the data being pointed at by &d to fill it properly, whereas variadic functions promote floats to doubles (not entirely sure why), so printf is always getting a double.

Positioning background image, adding padding

In case anyone else needs to add padding to something with background-image and background-size: contain or cover, I used the following which is a nice way of doing it. You can replace the border-width with 10% or 2vw or whatever you like.

.bg-image {
    background: url("/image/logo.png") no-repeat center #ffffff / contain;
    border: inset 10px transparent;
    box-sizing: border-box;
}

This means you don't have to define a width.

Double precision - decimal places

It is because it's being converted from a binary representation. Just because it has printed all those decimal digits doesn't mean it can represent all decimal values to that precision. Take, for example, this in Python:

>>> 0.14285714285714285
0.14285714285714285
>>> 0.14285714285714286
0.14285714285714285

Notice how I changed the last digit, but it printed out the same number anyway.

Actual meaning of 'shell=True' in subprocess

The benefit of not calling via the shell is that you are not invoking a 'mystery program.' On POSIX, the environment variable SHELL controls which binary is invoked as the "shell." On Windows, there is no bourne shell descendent, only cmd.exe.

So invoking the shell invokes a program of the user's choosing and is platform-dependent. Generally speaking, avoid invocations via the shell.

Invoking via the shell does allow you to expand environment variables and file globs according to the shell's usual mechanism. On POSIX systems, the shell expands file globs to a list of files. On Windows, a file glob (e.g., "*.*") is not expanded by the shell, anyway (but environment variables on a command line are expanded by cmd.exe).

If you think you want environment variable expansions and file globs, research the ILS attacks of 1992-ish on network services which performed subprogram invocations via the shell. Examples include the various sendmail backdoors involving ILS.

In summary, use shell=False.

Set a DateTime database field to "Now"

In SQL you need to use GETDATE():

UPDATE table SET date = GETDATE();

There is no NOW() function.


To answer your question:

In a large table, since the function is evaluated for each row, you will end up getting different values for the updated field.

So, if your requirement is to set it all to the same date I would do something like this (untested):

DECLARE @currDate DATETIME;
SET @currDate = GETDATE();

UPDATE table SET date = @currDate;

How do I view executed queries within SQL Server Management Studio?

Run the following query from Management Studio on a running process:

DBCC inputbuffer( spid# )

This will return the SQL currently being run against the database for the SPID provided. Note that you need appropriate permissions to run this command.

This is better than running a trace since it targets a specific SPID. You can see if it's long running based on its CPUTime and DiskIO.

Example to get details of SPID 64:

DBCC inputbuffer(64)

Angular 2 Show and Hide an element

Just add bind(this) in your setTimeout function it will start working

setTimeout(function() {
       this.edited = false;
       console.log(this.edited);
   }.bind(this), 3000);

and in HTML change

<div *ngIf="edited==true" class="alert alert-success alert-dismissible fade in" role="alert">
        <strong>List Saved!</strong> Your changes has been saved.
</div>

To

<div *ngIf="edited" class="alert alert-success alert-dismissible fade in" role="alert">
        <strong>List Saved!</strong> Your changes has been saved.
</div>

Turning off eslint rule for a specific file

Based on the number of rules you want to ignore (All, or Some), and the scope of disabling it (Line(s), File(s), Everywhere), we have 2 × 3 = 6 cases.


1) Disabling "All rules"


Case 1.1: You want to disable "All Rules" for "One or more Lines"

Two ways you can do this:

  1. Put /* eslint-disable-line */ at the end of the line(s),
  2. or /* eslint-disable-next-line */ right before the line.

Case 1.2: You want to disable "All Rules" for "One File"

  • Put the comment of /* eslint-disable */ at the top of the file.

Case 1.3: You want to disable "All rules" for "Some Files"

There are 3 ways you can do this:

  1. You can go with 1.2 and add /* eslint-disable */ on top of the files, one by one.
  2. You can put the file name(s) in .eslintignore. This works well especially if you have a path that you want to be ignored. (e.g. apidoc/**)
  3. Alternatively, if you don't want to have a separate .eslintignore file, you can add "eslintIgnore": ["file1.js", "file2.js"] in package.json as instructed here.

2) Disabling "Some Rules"


Case 2.1: You want to disable "Some Rules" for "One or more Lines"

Two ways you can do this:

  1. You can put /* eslint-disable-line quotes */ (replace quotes with your rules) at the end of the line(s),

  2. or /* eslint-disable-next-line no-alert, quotes, semi */ before the line.


Case 2.2: You want to disable "Some Rules" for "One File"

  • Put the /* eslint-disable no-use-before-define */ comment at the top of the file.

More examples here.


Case 2.3: You want to disable "Some Rules" for "Some files"

  • This is less straight-forward. You should put them in "excludedFiles" object of "overrides" section of your .eslintrc as instructed here.

Trying to pull files from my Github repository: "refusing to merge unrelated histories"

git checkout master
git merge origin/master --allow-unrelated-histories

Resolve conflict, then

git add -A .
git commit -m "Upload"
git push

What is the purpose of "pip install --user ..."?

Just a warning:

According to this issue, --user is currently not valid inside a virtual env's pip, since a user location doesn't really make sense for a virtual environment.

So do not use pip install --user some_pkg inside a virtual environment, otherwise, virtual environment's pip will be confused. See this answer for more details.

Adjust table column width to content size

The problem was the table width. I had used width: 100% for the table. The table columns are adjusted automatically after removing the width tag.

ByRef argument type mismatch in Excel VBA

Something is wrong with that string try like this:

Worksheets(data_sheet).Range("C2").Value = ProcessString(CStr(last_name))

How to ensure that there is a delay before a service is started in systemd?

You can create a .timer systemd unit file to control the execution of your .service unit file.

So for example, to wait for 1 minute after boot-up before starting your foo.service, create a foo.timer file in the same directory with the contents:

[Timer]
OnBootSec=1min

It is important that the service is disabled (so it doesn't start at boot), and the timer enabled, for all this to work (thanks to user tride for this):

systemctl disable foo.service
systemctl enable foo.timer

You can find quite a few more options and all information needed here: https://wiki.archlinux.org/index.php/Systemd/Timers

The name 'controlname' does not exist in the current context

exclude any other pages that reference the same code-behind file, for example an older page that you copied and pasted.

Default SQL Server Port

The default port of SQL server is 1433.

How to convert buffered image to image and vice-versa?

BufferedImage is a subclass of Image. You don't need to do any conversion.

Should I always use a parallel stream when possible?

Never parallelize an infinite stream with a limit. Here is what happens:

    public static void main(String[] args) {
        // let's count to 1 in parallel
        System.out.println(
            IntStream.iterate(0, i -> i + 1)
                .parallel()
                .skip(1)
                .findFirst()
                .getAsInt());
    }

Result

    Exception in thread "main" java.lang.OutOfMemoryError
        at ...
        at java.base/java.util.stream.IntPipeline.findFirst(IntPipeline.java:528)
        at InfiniteTest.main(InfiniteTest.java:24)
    Caused by: java.lang.OutOfMemoryError: Java heap space
        at java.base/java.util.stream.SpinedBuffer$OfInt.newArray(SpinedBuffer.java:750)
        at ...

Same if you use .limit(...)

Explanation here: Java 8, using .parallel in a stream causes OOM error

Similarly, don't use parallel if the stream is ordered and has much more elements than you want to process, e.g.

public static void main(String[] args) {
    // let's count to 1 in parallel
    System.out.println(
            IntStream.range(1, 1000_000_000)
                    .parallel()
                    .skip(100)
                    .findFirst()
                    .getAsInt());
}

This may run much longer because the parallel threads may work on plenty of number ranges instead of the crucial one 0-100, causing this to take very long time.

How find out which process is using a file in Linux?

You can use the fuser command, like:

fuser file_name

You will receive a list of processes using the file.

You can use different flags with it, in order to receive a more detailed output.

You can find more info in the fuser's Wikipedia article, or in the man pages.

Bootstrap 4: responsive sidebar menu to top navbar

It could be done in Bootstrap 4 using the responsive grid columns. One column for the sidebar and one for the main content.

Bootstrap 4 Sidebar switch to Top Navbar on mobile

<div class="container-fluid h-100">
    <div class="row h-100">
        <aside class="col-12 col-md-2 p-0 bg-dark">
            <nav class="navbar navbar-expand navbar-dark bg-dark flex-md-column flex-row align-items-start">
                <div class="collapse navbar-collapse">
                    <ul class="flex-md-column flex-row navbar-nav w-100 justify-content-between">
                        <li class="nav-item">
                            <a class="nav-link pl-0" href="#">Link</a>
                        </li>
                        ..
                    </ul>
                </div>
            </nav>
        </aside>
        <main class="col">
            ..
        </main>
    </div>
</div>

Alternate sidebar to top
Fixed sidebar to top

For the reverse (Top Navbar that becomes a Sidebar), can be done like this example

File Upload in WebView

In KitKat you can use the Storage Access Framework.

Storage Access Framework / Writing a Client App

What's the difference between the atomic and nonatomic attributes?

If you are using your property in multi-threaded code then you would be able to see the difference between nonatomic and atomic attributes. Nonatomic is faster than atomic and atomic is thread-safe, not nonatomic.

Vijayendra Tripathi has already given an example for a multi-threaded environment.

AttributeError: 'str' object has no attribute

The problem is in your playerMovement method. You are creating the string name of your room variables (ID1, ID2, ID3):

letsago = "ID" + str(self.dirDesc.values())

However, what you create is just a str. It is not the variable. Plus, I do not think it is doing what you think its doing:

>>>str({'a':1}.values())
'dict_values([1])'

If you REALLY needed to find the variable this way, you could use the eval function:

>>>foo = 'Hello World!'
>>>eval('foo')
'Hello World!'

or the globals function:

class Foo(object):
    def __init__(self):
        super(Foo, self).__init__()
    def test(self, name):
        print(globals()[name])

foo = Foo()
bar = 'Hello World!'
foo.text('bar')

However, instead I would strongly recommend you rethink you class(es). Your userInterface class is essentially a Room. It shouldn't handle player movement. This should be within another class, maybe GameManager or something like that.

How to count duplicate rows in pandas dataframe?

df.groupby(df.columns.tolist()).size().reset_index().\
    rename(columns={0:'records'})

   one  two  records
0    1    1        2
1    1    2        1

Bypass popup blocker on window.open when JQuery event.preventDefault() is set

Popup blockers will typically only allow window.open if used during the processing of a user event (like a click). In your case, you're calling window.open later, not during the event, because $.getJSON is asynchronous.

You have two options:

  1. Do something else, rather than window.open.

  2. Make the ajax call synchronous, which is something you should normally avoid like the plague as it locks up the UI of the browser. $.getJSON is equivalent to:

    $.ajax({
      url: url,
      dataType: 'json',
      data: data,
      success: callback
    });
    

    ...and so you can make your $.getJSON call synchronous by mapping your params to the above and adding async: false:

    $.ajax({
        url:      "redirect/" + pageId,
        async:    false,
        dataType: "json",
        data:     {},
        success:  function(status) {
            if (status == null) {
                alert("Error in verifying the status.");
            } else if(!status) {
                $("#agreement").dialog("open");
            } else {
                window.open(redirectionURL);
            }
        }
    });
    

    Again, I don't advocate synchronous ajax calls if you can find any other way to achieve your goal. But if you can't, there you go.

    Here's an example of code that fails the test because of the asynchronous call:

    Live example | Live source (The live links no longer work because of changes to JSBin)

    jQuery(function($) {
      // This version doesn't work, because the window.open is
      // not during the event processing
      $("#theButton").click(function(e) {
        e.preventDefault();
        $.getJSON("http://jsbin.com/uriyip", function() {
          window.open("http://jsbin.com/ubiqev");
        });
      });
    });
    

    And here's an example that does work, using a synchronous call:

    Live example | Live source (The live links no longer work because of changes to JSBin)

    jQuery(function($) {
      // This version does work, because the window.open is
      // during the event processing. But it uses a synchronous
      // ajax call, locking up the browser UI while the call is
      // in progress.
      $("#theButton").click(function(e) {
        e.preventDefault();
        $.ajax({
          url:      "http://jsbin.com/uriyip",
          async:    false,
          dataType: "json",
          success:  function() {
            window.open("http://jsbin.com/ubiqev");
          }
        });
      });
    });
    

Eclipse "cannot find the tag library descriptor" for custom tags (not JSTL!)

I was having the same problem using Tomcat 6.0 and Eclipse and I tried out something which my friend suggested and it worked for me. The link for the question I asked and my reply commented can be found here:

JSTL Tomcat 6.0 Cannot find the taglib descriptor Error

Let me know if this solves your "Cannot find the taglibrary descriptor" problem.

How do I execute a command and get the output of the command within C++ using POSIX?

#include <cstdio>
#include <iostream>
#include <memory>
#include <stdexcept>
#include <string>
#include <array>

std::string exec(const char* cmd) {
    std::array<char, 128> buffer;
    std::string result;
    std::unique_ptr<FILE, decltype(&pclose)> pipe(popen(cmd, "r"), pclose);
    if (!pipe) {
        throw std::runtime_error("popen() failed!");
    }
    while (fgets(buffer.data(), buffer.size(), pipe.get()) != nullptr) {
        result += buffer.data();
    }
    return result;
}

Pre-C++11 version:

#include <iostream>
#include <stdexcept>
#include <stdio.h>
#include <string>

std::string exec(const char* cmd) {
    char buffer[128];
    std::string result = "";
    FILE* pipe = popen(cmd, "r");
    if (!pipe) throw std::runtime_error("popen() failed!");
    try {
        while (fgets(buffer, sizeof buffer, pipe) != NULL) {
            result += buffer;
        }
    } catch (...) {
        pclose(pipe);
        throw;
    }
    pclose(pipe);
    return result;
}

Replace popen and pclose with _popen and _pclose for Windows.

"if not exist" command in batch file

if not exist "%USERPROFILE%\.qgis-custom\" (
    mkdir "%USERPROFILE%\.qgis-custom" 2>nul
    if not errorlevel 1 (
        xcopy "%OSGEO4W_ROOT%\qgisconfig" "%USERPROFILE%\.qgis-custom" /s /v /e
    )
)

You have it almost done. The logic is correct, just some little changes.

This code checks for the existence of the folder (see the ending backslash, just to differentiate a folder from a file with the same name).

If it does not exist then it is created and creation status is checked. If a file with the same name exists or you have no rights to create the folder, it will fail.

If everyting is ok, files are copied.

All paths are quoted to avoid problems with spaces.

It can be simplified (just less code, it does not mean it is better). Another option is to always try to create the folder. If there are no errors, then copy the files

mkdir "%USERPROFILE%\.qgis-custom" 2>nul 
if not errorlevel 1 (
    xcopy "%OSGEO4W_ROOT%\qgisconfig" "%USERPROFILE%\.qgis-custom" /s /v /e
)

In both code samples, files are not copied if the folder is not being created during the script execution.

EDITED - As dbenham comments, the same code can be written as a single line

md "%USERPROFILE%\.qgis-custom" 2>nul && xcopy "%OSGEO4W_ROOT%\qgisconfig" "%USERPROFILE%\.qgis-custom" /s /v /e

The code after the && will only be executed if the previous command does not set errorlevel. If mkdir fails, xcopy is not executed.

Syntax for if/else condition in SCSS mixin

You can assign default parameter values inline when you first create the mixin:

@mixin clearfix($width: 'auto') {

  @if $width == 'auto' {

    // if width is not passed, or empty do this

  } @else {

    display: inline-block;
    width: $width;

  }
}

PHP append one array to another (not array_push or +)

foreach loop is faster than array_merge to append values to an existing array, so choose the loop instead if you want to add an array to the end of another.

// Create an array of arrays
$chars = [];
for ($i = 0; $i < 15000; $i++) {
    $chars[] = array_fill(0, 10, 'a');
}

// test array_merge
$new = [];
$start = microtime(TRUE);
foreach ($chars as $splitArray) {
    $new = array_merge($new, $splitArray);
}
echo microtime(true) - $start; // => 14.61776 sec

// test foreach
$new = [];
$start = microtime(TRUE);
foreach ($chars as $splitArray) {
    foreach ($splitArray as $value) {
        $new[] = $value;
    }
}
echo microtime(true) - $start; // => 0.00900101 sec
// ==> 1600 times faster

What is code coverage and how do YOU measure it?

Code coverage is a measurement of how many lines/blocks/arcs of your code are executed while the automated tests are running.

Code coverage is collected by using a specialized tool to instrument the binaries to add tracing calls and run a full set of automated tests against the instrumented product. A good tool will give you not only the percentage of the code that is executed, but also will allow you to drill into the data and see exactly which lines of code were executed during a particular test.

Our team uses Magellan - an in-house set of code coverage tools. If you are a .NET shop, Visual Studio has integrated tools to collect code coverage. You can also roll some custom tools, like this article describes.

If you are a C++ shop, Intel has some tools that run for Windows and Linux, though I haven't used them. I've also heard there's the gcov tool for GCC, but I don't know anything about it and can't give you a link.

As to how we use it - code coverage is one of our exit criteria for each milestone. We have actually three code coverage metrics - coverage from unit tests (from the development team), scenario tests (from the test team) and combined coverage.

BTW, while code coverage is a good metric of how much testing you are doing, it is not necessarily a good metric of how well you are testing your product. There are other metrics you should use along with code coverage to ensure the quality.

MongoDB relationships: embed or reference?

I know this is quite old but if you are looking for the answer to the OP's question on how to return only specified comment, you can use the $ (query) operator like this:

db.question.update({'comments.content': 'xxx'}, {'comments.$': true})

good postgresql client for windows?

I heartily recommended dbVis. The client runs on Mac, Windows and Linux and supports a variety of database servers, including PostgreSQL.

How to convert "Mon Jun 18 00:00:00 IST 2012" to 18/06/2012?

I hope following program will solve your problem

String dateStr = "Mon Jun 18 00:00:00 IST 2012";
DateFormat formatter = new SimpleDateFormat("E MMM dd HH:mm:ss Z yyyy");
Date date = (Date)formatter.parse(dateStr);
System.out.println(date);        

Calendar cal = Calendar.getInstance();
cal.setTime(date);
String formatedDate = cal.get(Calendar.DATE) + "/" + (cal.get(Calendar.MONTH) + 1) + "/" +         cal.get(Calendar.YEAR);
System.out.println("formatedDate : " + formatedDate);    

The cast to value type 'Int32' failed because the materialized value is null

I was also facing the same problem and solved through making column as nullable using "?" operator.

Sequnce = db.mstquestionbanks.Where(x => x.IsDeleted == false && x.OrignalFormID == OriginalFormIDint).Select(x=><b>(int?)x.Sequence</b>).Max().ToString();

Sometimes null is returned.

HashMap allows duplicates?

m.put(null,null); // here key=null, value=null
m.put(null,a);    // here also key=null, and value=a

Duplicate keys are not allowed in hashmap.
However,value can be duplicated.

How to do multiple arguments to map function where one remains the same in python?

Sometimes I resolved similar situations (such as using pandas.apply method) using closures

In order to use them, you define a function which dynamically defines and returns a wrapper for your function, effectively making one of the parameters a constant.

Something like this:

def add(x, y):
   return x + y

def add_constant(y):
    def f(x):
        return add(x, y)
    return f

Then, add_constant(y) returns a function which can be used to add y to any given value:

>>> add_constant(2)(3)
5

Which allows you to use it in any situation where parameters are given one at a time:

>>> map(add_constant(2), [1,2,3])
[3, 4, 5]

edit

If you do not want to have to write the closure function somewhere else, you always have the possibility to build it on the fly using a lambda function:

>>> map(lambda x: add(x, 2), [1, 2, 3])
[3, 4, 5]

Image inside div has extra space below the image

I used line-height:0 and it works fine for me.

Python-equivalent of short-form "if" in C++

While a = 'foo' if True else 'bar' is the more modern way of doing the ternary if statement (python 2.5+), a 1-to-1 equivalent of your version might be:

a = (b == True and "123" or "456" )

... which in python should be shortened to:

a = b is True and "123" or "456"

... or if you simply want to test the truthfulness of b's value in general...

a = b and "123" or "456"

? : can literally be swapped out for and or

How to downgrade or install an older version of Cocoapods

PROMPT> gem uninstall cocoapods

Select gem to uninstall:
 1. cocoapods-0.32.1
 2. cocoapods-0.33.1
 3. cocoapods-0.36.0.beta.2
 4. cocoapods-0.38.2
 5. cocoapods-0.39.0
 6. cocoapods-1.0.0
 7. All versions
> 6
Successfully uninstalled cocoapods-1.0.0
PROMPT> gem install cocoapods -v 0.39.0
Successfully installed cocoapods-0.39.0
Parsing documentation for cocoapods-0.39.0
Done installing documentation for cocoapods after 1 seconds
1 gem installed
PROMPT> pod --version
0.39.0
PROMPT>

How to access pandas groupby dataframe by key

Rather than

gb.get_group('foo')

I prefer using gb.groups

df.loc[gb.groups['foo']]

Because in this way you can choose multiple columns as well. for example:

df.loc[gb.groups['foo'],('A','B')]

C# - Insert a variable number of spaces into a string? (Formatting an output file)

I agree with Justin, and the WhiteSpace CHAR can be referenced using ASCII codes here Character number 32 represents a white space, Therefore:

string.Empty.PadRight(totalLength, (char)32);

An alternative approach: Create all spaces manually within a custom method and call it:

private static string GetSpaces(int totalLength)
    {
        string result = string.Empty;
        for (int i = 0; i < totalLength; i++)
        {
            result += " ";
        }
        return result;
    }

And call it in your code to create white spaces: GetSpaces(14);

RESTful API methods; HEAD & OPTIONS

As per: http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html

9.2 OPTIONS

The OPTIONS method represents a request for information about the communication options available on the request/response chain identified by the Request-URI. This method allows the client to determine the options and/or requirements associated with a resource, or the capabilities of a server, without implying a resource action or initiating a resource retrieval.

Responses to this method are not cacheable.

If the OPTIONS request includes an entity-body (as indicated by the presence of Content-Length or Transfer-Encoding), then the media type MUST be indicated by a Content-Type field. Although this specification does not define any use for such a body, future extensions to HTTP might use the OPTIONS body to make more detailed queries on the server. A server that does not support such an extension MAY discard the request body.

If the Request-URI is an asterisk ("*"), the OPTIONS request is intended to apply to the server in general rather than to a specific resource. Since a server's communication options typically depend on the resource, the "*" request is only useful as a "ping" or "no-op" type of method; it does nothing beyond allowing the client to test the capabilities of the server. For example, this can be used to test a proxy for HTTP/1.1 compliance (or lack thereof).

If the Request-URI is not an asterisk, the OPTIONS request applies only to the options that are available when communicating with that resource.

A 200 response SHOULD include any header fields that indicate optional features implemented by the server and applicable to that resource (e.g., Allow), possibly including extensions not defined by this specification. The response body, if any, SHOULD also include information about the communication options. The format for such a body is not defined by this specification, but might be defined by future extensions to HTTP. Content negotiation MAY be used to select the appropriate response format. If no response body is included, the response MUST include a Content-Length field with a field-value of "0".

The Max-Forwards request-header field MAY be used to target a specific proxy in the request chain. When a proxy receives an OPTIONS request on an absoluteURI for which request forwarding is permitted, the proxy MUST check for a Max-Forwards field. If the Max-Forwards field-value is zero ("0"), the proxy MUST NOT forward the message; instead, the proxy SHOULD respond with its own communication options. If the Max-Forwards field-value is an integer greater than zero, the proxy MUST decrement the field-value when it forwards the request. If no Max-Forwards field is present in the request, then the forwarded request MUST NOT include a Max-Forwards field.

9.4 HEAD

The HEAD method is identical to GET except that the server MUST NOT return a message-body in the response. The metainformation contained in the HTTP headers in response to a HEAD request SHOULD be identical to the information sent in response to a GET request. This method can be used for obtaining metainformation about the entity implied by the request without transferring the entity-body itself. This method is often used for testing hypertext links for validity, accessibility, and recent modification.

The response to a HEAD request MAY be cacheable in the sense that the information contained in the response MAY be used to update a previously cached entity from that resource. If the new field values indicate that the cached entity differs from the current entity (as would be indicated by a change in Content-Length, Content-MD5, ETag or Last-Modified), then the cache MUST treat the cache entry as stale.

how to remove css property using javascript?

element.style.height = null;

output:

<div style="height:100px;"> 
// results: 
<div style="">

How to show alert message in mvc 4 controller?

You cannot show an alert from a controller. There is one way communication from the client to the server.The server can therefore not tell the client to do anything. The client requests and the server gives a response.

You therefore need to use javascript when the response returns to show a messagebox of some sort.

OR

using jquery on the button that calls the controller action

<script>
 $(document).ready(function(){
  $("#submitButton").on("click",function()
  {
   alert('Your Message');
  });

});
<script>

How to create a HTML Cancel button that redirects to a URL

cancel is not a valid value for a type attribute, so the button is probably defaulting to submit and continuing to submit the form. You probably mean type="button".

(The javascript: should be removed though, while it doesn't do any harm, it is an entirely useless label)

You don't have any button-like functionality though, so would be better off with:

<a href="http://stackoverflow.com"> Cancel </a>

… possibly with some CSS to make it look like a button.

SaveFileDialog setting default path and file type?

Environment.GetSystemVariable("%SystemDrive%"); will provide the drive OS installed, and you can set filters to savedialog Obtain file path of C# save dialog box

How to uninstall Ruby from /usr/local?

Edit: As suggested in comments. This solution is for Linux OS. That too if you have installed ruby manually from package-manager.

If you want to have multiple ruby versions, better to have RVM. In that case you don't need to remove ruby older version.

Still if want to remove then follow the steps below:

First you should find where Ruby is:

whereis ruby

will list all the places where it exists on your system, then you can remove all them explicitly. Or you can use something like this:

rm -rf /usr/local/lib/ruby
rm -rf /usr/lib/ruby
rm -f /usr/local/bin/ruby
rm -f /usr/bin/ruby
rm -f /usr/local/bin/irb
rm -f /usr/bin/irb
rm -f /usr/local/bin/gem
rm -f /usr/bin/gem

Subtract days, months, years from a date in JavaScript

This is a pure-function which takes a passed-in starting date, building on Phil's answer:

function deltaDate(input, days, months, years) {
    return new Date(
      input.getFullYear() + years, 
      input.getMonth() + months, 
      Math.min(
        input.getDate() + days,
        new Date(input.getFullYear() + years, input.getMonth() + months + 1, 0).getDate()
      )
    );
}

e.g. writes the date one month ago to the console log:

console.log(deltaDate(new Date(), 0, -1, 0));

e.g. subtracts a month from March 30, 2020:

console.log(deltaDate(new Date(2020, 2, 30), 0, -1, 0)); // Feb 29, 2020

Note that this works even if you go past the end of the month or year.

Update: As the example above shows, this has been updated to handle variances in the number of days in a month.

How to convert String into Hashmap in java

You can do it in single line, for any object type not just Map.

(Since I use Gson quite liberally, I am sharing a Gson based approach)

Gson gson = new Gson();    
Map<Object,Object> attributes = gson.fromJson(gson.toJson(value),Map.class);

What it does is:

  1. gson.toJson(value) will serialize your object into its equivalent Json representation.
  2. gson.fromJson will convert the Json string to specified object. (in this example - Map)

There are 2 advantages with this approach:

  1. The flexibility to pass an Object instead of String to toJson method.
  2. You can use this single line to convert to any object even your own declared objects.

How to do a num_rows() on COUNT query in codeigniter?

In CI it's really simple actually, all you need is

$this->db->where('account_status', $i);
$num_rows = $this->db->count_all_results('users');
var_dump($num_rows); // prints the number of rows in table users with account status $i

Replacement for deprecated sizeWithFont: in iOS 7?

- (CGSize) sizeWithMyFont:(UIFont *)fontToUse
{
    if ([self respondsToSelector:@selector(sizeWithAttributes:)])
    {
        NSDictionary* attribs = @{NSFontAttributeName:fontToUse};
        return ([self sizeWithAttributes:attribs]);
    }
    return ([self sizeWithFont:fontToUse]);
}

What is the equivalent of bigint in C#?

I was handling a bigint datatype to be shown in a DataGridView and made it like this

something = (int)(Int64)data_reader[0];

How to draw a filled circle in Java?

public void paintComponent(Graphics g) {
   super.paintComponent(g);
   Graphics2D g2d = (Graphics2D)g;
   // Assume x, y, and diameter are instance variables.
   Ellipse2D.Double circle = new Ellipse2D.Double(x, y, diameter, diameter);
   g2d.fill(circle);
   ...
}

Here are some docs about paintComponent (link).

You should override that method in your JPanel and do something similar to the code snippet above.

In your ActionListener you should specify x, y, diameter and call repaint().

Java HTTP Client Request with defined timeout

If you are using Http Client version 4.3 and above you should be using this:

RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(30 * 1000).build();
HttpClient httpClient = HttpClientBuilder.create().setDefaultRequestConfig(requestConfig).build();

What does "res.render" do, and what does the html file look like?

What does res.render do and what does the html file look like?

res.render() function compiles your template (please don't use ejs), inserts locals there, and creates html output out of those two things.


Answering Edit 2 part.

// here you set that all templates are located in `/views` directory
app.set('views', __dirname + '/views');

// here you set that you're using `ejs` template engine, and the
// default extension is `ejs`
app.set('view engine', 'ejs');

// here you render `orders` template
response.render("orders", {orders: orders_json});

So, the template path is views/ (first part) + orders (second part) + .ejs (third part) === views/orders.ejs


Anyway, express.js documentation is good for what it does. It is API reference, not a "how to use node.js" book.

Fitting a density curve to a histogram in R

Here's the way I do it:

foo <- rnorm(100, mean=1, sd=2)
hist(foo, prob=TRUE)
curve(dnorm(x, mean=mean(foo), sd=sd(foo)), add=TRUE)

A bonus exercise is to do this with ggplot2 package ...

How to NodeJS require inside TypeScript file?

The correct syntax is:

import sampleModule = require('modulename');

or

import * as sampleModule from 'modulename';

Then compile your TypeScript with --module commonjs.

If the package doesn't come with an index.d.ts file and its package.json doesn't have a "typings" property, tsc will bark that it doesn't know what 'modulename' refers to. For this purpose you need to find a .d.ts file for it on http://definitelytyped.org/, or write one yourself.

If you are writing code for Node.js you will also want the node.d.ts file from http://definitelytyped.org/.

Recover sa password

The best way is to simply reset the password by connecting with a domain/local admin (so you may need help from your system administrators), but this only works if SQL Server was set up to allow local admins (these are now left off the default admin group during setup).

If you can't use this or other existing methods to recover / reset the SA password, some of which are explained here:

Then you could always backup your important databases, uninstall SQL Server, and install a fresh instance.

You can also search for less scrupulous ways to do it (e.g. there are password crackers that I am not enthusiastic about sharing).

As an aside, the login properties for sa would never say Windows Authentication. This is by design as this is a SQL Authentication account. This does not mean that Windows Authentication is disabled at the instance level (in fact it is not possible to do so), it just doesn't apply for a SQL auth account.

I wrote a tip on using PSExec to connect to an instance using the NT AUTHORITY\SYSTEM account (which works < SQL Server 2012), and a follow-up that shows how to hack the SqlWriter service (which can work on more modern versions):

And some other resources:

What does "#include <iostream>" do?

In order to read or write to the standard input/output streams you need to include it.

int main( int argc, char * argv[] )
{
    std::cout << "Hello World!" << std::endl;
    return 0;
}

That program will not compile unless you add #include <iostream>

The second line isn't necessary

using namespace std;

What that does is tell the compiler that symbol names defined in the std namespace are to be brought into your program's scope, so you can omit the namespace qualifier, and write for example

#include <iostream>
using namespace std;
int main( int argc, char * argv[] )
{
    cout << "Hello World!" << endl;
    return 0;
}

Notice you no longer need to refer to the output stream with the fully qualified name std::cout and can use the shorter name cout.

I personally don't like bringing in all symbols in the namespace of a header file... I'll individually select the symbols I want to be shorter... so I would do this:

#include <iostream>
using std::cout;
using std::endl;

int main( int argc, char * argv[] )
{
    cout << "Hello World!" << endl;
    return 0;
}

But that is a matter of personal preference.

How can I make a TextArea 100% width without overflowing when padding is present in CSS?

I came across another solution here that is so simple: add padding-right to the textarea's container. This keeps the margin, border, and padding on the textarea, which avoids the problem that Beck pointed out about the focus highlight that chrome and safari put around the textarea.

The container's padding-right should be the sum of the effective margin, border, and padding on both sides of the textarea, plus any padding you may otherwise want for the container. So, for the case in the original question:

textarea{
    border:1px solid #999999;
    width:100%;
    margin:5px 0;
    padding:3px;
}
.textareacontainer{
    padding-right: 8px; /* 1 + 3 + 3 + 1 */
}

<div class="textareacontainer">
    <textarea></textarea>
</div>

CSS flexbox vertically/horizontally center image WITHOUT explicitely defining parent height

Without explicitly defining the height I determined I need to apply the flex value to the parent and grandparent div elements...

<div style="display: flex;">
<div style="display: flex;">
 <img alt="No, he'll be an engineer." src="theknack.png" style="margin: auto;" />
</div>
</div>

If you're using a single element (e.g. dead-centered text in a single flex element) use the following:

align-items: center;
display: flex;
justify-content: center;

How to get values and keys from HashMap?

Map is internally made up of Map.Entry objects. Each Entry contains key and value. To get key and value from the entry you use accessor and modifier methods.

If you want to get values with given key, use get() method and to insert value, use put() method.

#Define and initialize map;
Map map = new HashMap();
map.put("USA",1)
map.put("Japan",3)
map.put("China",2)
map.put("India",5)
map.put("Germany",4)

map.get("Germany") // returns 4

If you want to get the set of keys from map, you can use keySet() method

Set keys = map.keySet();
System.out.println("All keys are: " + keys);
// To get all key: value
for(String key: keys){
    System.out.println(key + ": " + map.get(key));
}

Generally, To get all keys and values from the map, you have to follow the sequence in the following order:

  • Convert Hashmap to MapSet to get set of entries in Map with entryset() method.:
    Set st = map.entrySet();
  • Get the iterator of this set:
    Iterator it = st.iterator();
  • Get Map.Entry from the iterator:
    Map.Entry entry = it.next();
  • use getKey() and getValue() methods of the Map.Entry to get keys and values.
// Now access it
Set st = (Set) map.entrySet();
Iterator it = st.iterator();
while(it.hasNext()){
    Map.Entry entry = mapIterator.next();
    System.out.print(entry.getKey() + " : " + entry.getValue());
}

In short, use iterator directly in for

for(Map.Entry entry:map.entrySet()){
    System.out.print(entry.getKey() + " : " + entry.getValue());
}

Python sys.argv lists and indexes

In a nutshell, sys.argv is a list of the words that appear in the command used to run the program. The first word (first element of the list) is the name of the program, and the rest of the elements of the list are any arguments provided. In most computer languages (including Python), lists are indexed from zero, meaning that the first element in the list (in this case, the program name) is sys.argv[0], and the second element (first argument, if there is one) is sys.argv[1], etc.

The test len(sys.argv) >= 2 simply checks wither the list has a length greater than or equal to 2, which will be the case if there was at least one argument provided to the program.

How do you grep a file and get the next 5 lines

Some awk version.

awk '/19:55/{c=5} c-->0'
awk '/19:55/{c=5} c && c--'

When pattern found, set c=5
If c is true, print and decrease number of c

System.Security.SecurityException when writing to Event Log

FYI...my problem was that accidently selected "Local Service" as the Account on properties of the ProcessInstaller instead of "Local System". Just mentioning for anyone else who followed the MSDN tutorial as the Local Service selection shows first and I wasn't paying close attention....

Convert an ArrayList to an object array

Convert an ArrayList to an object array

ArrayList has a constructor that takes a Collection, so the common idiom is:

List<T> list = new ArrayList<T>(Arrays.asList(array));

Which constructs a copy of the list created by the array.

now, Arrays.asList(array) will wrap the array, so changes to the list will affect the array, and visa versa. Although you can't add or remove

elements from such a list.

Best database field type for a URL

  1. Lowest common denominator max URL length among popular web browsers: 2,083 (Internet Explorer)
  1. http://dev.mysql.com/doc/refman/5.0/en/char.html
    Values in VARCHAR columns are variable-length strings. The length can be specified as a value from 0 to 255 before MySQL 5.0.3, and 0 to 65,535 in 5.0.3 and later versions. The effective maximum length of a VARCHAR in MySQL 5.0.3 and later is subject to the maximum row size (65,535 bytes, which is shared among all columns) and the character set used.
  1. So ...
    < MySQL 5.0.3 use TEXT
    or
    >= MySQL 5.0.3 use VARCHAR(2083)

Change File Extension Using C#

You should do a move of the file to rename it. In your example code you are only changing the string, not the file:

myfile= "c:/my documents/my images/cars/a.jpg";
string extension = Path.GetExtension(myffile); 
myfile.replace(extension,".Jpeg");

you are only changing myfile (which is a string). To move the actual file, you should do

FileInfo f = new FileInfo(myfile);
f.MoveTo(Path.ChangeExtension(myfile, ".Jpeg"));

See FileInfo.MoveTo

How do you find all subclasses of a given class in Java?

This is not possible to do using only the built-in Java Reflections API.

A project exists that does the necessary scanning and indexing of your classpath so you can get access this information...

Reflections

A Java runtime metadata analysis, in the spirit of Scannotations

Reflections scans your classpath, indexes the metadata, allows you to query it on runtime and may save and collect that information for many modules within your project.

Using Reflections you can query your metadata for:

  • get all subtypes of some type
  • get all types annotated with some annotation
  • get all types annotated with some annotation, including annotation parameters matching
  • get all methods annotated with some

(disclaimer: I have not used it, but the project's description seems to be an exact fit for your needs.)

What do the terms "CPU bound" and "I/O bound" mean?

An application is CPU-bound when the arithmetic/logical/floating-point (A/L/FP) performance during the execution is mostly near the theoretical peak-performance of the processor (data provided by the manufacturer and determined by the characteristics of the processor: number of cores, frequency, registers, ALUs, FPUs, etc.).

The peek performance is very difficult to be achieved in real-world applications, for not saying impossible. Most of the applications access memory in different parts of the execution and the processor is not doing A/L/FP operations during several cycles. This is called Von Neumann Limitation due to the distance that exists between the memory and the processor.

If you want to be near the CPU peak-performance a strategy could be to try to reuse most of the data in the cache memory in order to avoid requiring data from the main memory. An algorithm that exploits this feature is the matrix-matrix multiplication (if both matrices can be stored in the cache memory). This happens because if the matrices are size n x n then you need to do about 2 n^3 operations using only 2 n^2 FP numbers of data. On the other hand matrix addition, for example, is a less CPU-bound or a more memory-bound application than the matrix multiplication since it requires only n^2 FLOPs with the same data.

In the following figure the FLOPs obtained with a naive algorithms for the matrix addition and the matrix multiplication in an Intel i5-9300H, is shown:

FLOPs comparison between Matrix Addition and Matrix Multiplication

Note that as expected the performance of the matrix multiplication in bigger than the matrix addition. These results can be reproduced by running test/gemm and test/matadd available in this repository.

I suggest also to see the video given by J. Dongarra about this effect.

How can I get the CheckBoxList selected values, what I have doesn't seem to work C#.NET/VisualWebPart

An elegant way to implement this would be to make an extension method, like this:

public static class Extensions
{
    public static List<string> GetSelectedItems(this CheckBoxList cbl)
    {
        var result = new List<string>();

        foreach (ListItem item in cbl.Items)
            if (item.Selected)
                result.Add(item.Value);

        return result;
    }
}

I can then use something like this to compose a string will all values separated by ';':

string.Join(";", cbl.GetSelectedItems());

$date + 1 year?

Try This

$nextyear  = date("M d,Y",mktime(0, 0, 0, date("m",strtotime($startDate)),   date("d",strtotime($startDate)),   date("Y",strtotime($startDate))+1));

How can I initialize a MySQL database with schema in a Docker container?

I had this same issue where I wanted to initialize my MySQL Docker instance's schema, but I ran into difficulty getting this working after doing some Googling and following others' examples. Here's how I solved it.

1) Dump your MySQL schema to a file.

mysqldump -h <your_mysql_host> -u <user_name> -p --no-data <schema_name> > schema.sql

2) Use the ADD command to add your schema file to the /docker-entrypoint-initdb.d directory in the Docker container. The docker-entrypoint.sh file will run any files in this directory ending with ".sql" against the MySQL database.

Dockerfile:

FROM mysql:5.7.15

MAINTAINER me

ENV MYSQL_DATABASE=<schema_name> \
    MYSQL_ROOT_PASSWORD=<password>

ADD schema.sql /docker-entrypoint-initdb.d

EXPOSE 3306

3) Start up the Docker MySQL instance.

docker-compose build
docker-compose up

Thanks to Setting up MySQL and importing dump within Dockerfile for clueing me in on the docker-entrypoint.sh and the fact that it runs both SQL and shell scripts!

Docker container not starting (docker start)

What I need is to use Docker with MariaDb on different port /3301/ on my Ubuntu machine because I already had MySql installed and running on 3306.

To do this after half day searching did it using:

docker run -it -d -p 3301:3306 -v ~/mdbdata/mariaDb:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=root --name mariaDb mariadb

This pulls the image with latest MariaDb, creates container called mariaDb, and run mysql on port 3301. All data of which is located in home directory in /mdbdata/mariaDb.

To login in mysql after that can use:

mysql -u root -proot -h 127.0.0.1 -P3301

Used sources are:

The answer of Iarks in this article /using -it -d was the key :) /

how-to-install-and-use-docker-on-ubuntu-16-04

installing-and-using-mariadb-via-docker

mariadb-and-docker-use-cases-part-1

Good luck all!

Reset MySQL root password using ALTER USER statement after install on Mac

If you use MySQL 5.7.6 and later:

ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass';

If you use MySQL 5.7.5 and earlier:

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

MySQL Documentation

How to disable auto-play for local video in iframe

Try This Code for disable auto play video.

Its Working . Please Vote if your are done with this

<div class="embed-responsive embed-responsive-16by9">
    <video controls="true" class="embed-responsive-item">
      <source src="example.mp4" type="video/mp4" />
    </video>
</div>

How to define two angular apps / modules in one page?

You can bootstrap multiple angular applications, but:

1) You need to manually bootstrap them

2) You should not use "document" as the root, but the node where the angular interface is contained to:

var todoRootNode = jQuery('[ng-controller=TodoController]');
angular.bootstrap(todoRootNode, ['TodoApp']);

This would be safe.

How to list all the files in a commit?

Preferred Way (because it's a plumbing command; meant to be programmatic):

$ git diff-tree --no-commit-id --name-only -r bd61ad98
index.html
javascript/application.js
javascript/ie6.js

Another Way (less preferred for scripts, because it's a porcelain command; meant to be user-facing)

$ git show --pretty="" --name-only bd61ad98    
index.html
javascript/application.js
javascript/ie6.js

  • The --no-commit-id suppresses the commit ID output.
  • The --pretty argument specifies an empty format string to avoid the cruft at the beginning.
  • The --name-only argument shows only the file names that were affected (Thanks Hank). Use --name-status instead, if you want to see what happened to each file (Deleted, Modified, Added)
  • The -r argument is to recurse into sub-trees

LINQ: Select where object does not contain items from list

I have not tried this, so I am not guarantueeing anything, however

foreach Bar f in filterBars
{
     search(f)
}
Foo search(Bar b)
{
    fooSelect = (from f in fooBunch
                 where !(from b in f.BarList select b.BarId).Contains(b.ID)
                 select f).ToList();

    return fooSelect;
}

Hide div if screen is smaller than a certain width

Use media queries. Your CSS code would be:

@media screen and (max-width: 1024px) {
    .yourClass {
        display: none !important;
    }
}

Is an entity body allowed for an HTTP DELETE request?

It seems ElasticSearch uses this: https://www.elastic.co/guide/en/elasticsearch/reference/5.x/search-request-scroll.html#_clear_scroll_api

Which means Netty support this.

Like mentionned in comments it may not be the case anymore

Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (default-compile)

I had the same problem, check the installed jre used by Maven in your Run Configuration...

In your case, I think that the maven-compiler-plugin:jar:2.3.2 needs a jdk1.6

To do this : Run Configuration > YOUR_MAVEN_BUILD > JRE > Alternate JREenter image description here

Hope this helps.

Firefox "ssl_error_no_cypher_overlap" error

If you review the process of SSL negotiation at Wikipedia, you will know that at the beginning ClientHello and ServerHello messages are sent between the browser and the server.

Only if the cyphers provided in ClientHello have overlapping items on the server, ServerHello message will contain a cypher that both sides support. Otherwise, SSL connection will not be initiated as there is no common cypher.

To resolve the problem, you need to install cyphers (usually at OS level), instead of trying hard on the browser (usually the browser relies on the OS). I am familiar with Windows and IE, but I know little about Linux and Firefox, so I can only point out what's wrong but cannot deliver you a solution.

Understanding .get() method in Python

Start here http://docs.python.org/tutorial/datastructures.html#dictionaries

Then here http://docs.python.org/library/stdtypes.html#mapping-types-dict

Then here http://docs.python.org/library/stdtypes.html#dict.get

characters.get( key, default )

key is a character

default is 0

If the character is in the dictionary, characters, you get the dictionary object.

If not, you get 0.


Syntax:

get(key[, default])

Return the value for key if key is in the dictionary, else default. If default is not given, it defaults to None, so that this method never raises a KeyError.

Best way to format multiple 'or' conditions in an if statement (Java)

With Java 8, you could use a primitive stream:

if (IntStream.of(12, 16, 19).anyMatch(i -> i == x))

but this may have a slight overhead (or not), depending on the number of comparisons.

Problems installing the devtools package

CentOS 7:

I tried solutions in this post

sudo yum -y install libcurl libcurl-devel
sudo yum -y install openssl-devel

but wasn't enough.

Checking R error in Console gave me the anwser. In my case it was lacking libxml-2.0 below (and Console printed an explanation with package name to different Linux versions and other possible R configs)

sudo yum -y install libxml2-devel

Datatables on-the-fly resizing

Have you tried capturing the div resize event and doing .fnDraw() on the datatable? fnDraw should resize the table for you

node.js shell command execution

A simplified version of the accepted answer (third point), just worked for me.

function run_cmd(cmd, args, callBack ) {
    var spawn = require('child_process').spawn;
    var child = spawn(cmd, args);
    var resp = "";

    child.stdout.on('data', function (buffer) { resp += buffer.toString() });
    child.stdout.on('end', function() { callBack (resp) });
} // ()

Usage:

run_cmd( "ls", ["-l"], function(text) { console.log (text) });

run_cmd( "hostname", [], function(text) { console.log (text) });

Return anonymous type results?

No you cannot return anonymous types without going through some trickery.

If you were not using C#, what you would be looking for (returning multiple data without a concrete type) is called a Tuple.

There are alot of C# tuple implementations, using the one shown here, your code would work like this.

public IEnumerable<Tuple<Dog,Breed>> GetDogsWithBreedNames()
{
    var db = new DogDataContext(ConnectString);
    var result = from d in db.Dogs
                 join b in db.Breeds on d.BreedId equals b.BreedId
                 select new Tuple<Dog,Breed>(d, b);

    return result;
}

And on the calling site:

void main() {
    IEnumerable<Tuple<Dog,Breed>> dogs = GetDogsWithBreedNames();
    foreach(Tuple<Dog,Breed> tdog in dogs)
    {
        Console.WriteLine("Dog {0} {1}", tdog.param1.Name, tdog.param2.BreedName);
    }
}

Regular expression for decimal number

\d{1}(\.\d{1,3})?

Match a single digit 0..9 «\d{1}»
   Exactly 1 times «{1}»
Match the regular expression below and capture its match into backreference number 1 «(\.\d{1,3})?»
   Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
   Match the character “.” literally «\.»
   Match a single digit 0..9 «\d{1,3}»
      Between one and 3 times, as many times as possible, giving back as needed (greedy) «{1,3}»


Created with RegexBuddy

Matches:
1
1.2
1.23
1.234

SQL: How to perform string does not equal

The strcomp function may be appropriate here (returns 0 when strings are identical):

 SELECT * from table WHERE Strcmp(user, testername) <> 0;

Radio/checkbox alignment in HTML/CSS

I wouldn't use tables for this at all. CSS can easily do this.

I would do something like this:

   <p class="clearfix">
      <input id="option1" type="radio" name="opt" />
      <label for="option1">Option 1</label>
   </p>

p { margin: 0px 0px 10px 0px; }
input { float: left; width: 50px; }
label { margin: 0px 0px 0px 10px; float: left; }

Note: I have used the clearfix class from : http://www.positioniseverything.net/easyclearing.html

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

.clearfix {display: inline-block;}

/* Hides from IE-mac \*/
* html .clearfix {height: 1%;}
.clearfix {display: block;}
/* End hide from IE-mac */

How to mount a single file in a volume

For those who use Docker Desktop for Mac: If the file is present in your local filesystem but it's mounted as a directory inside the container, probably, you didn't share the file/directory with Docker Desktop. You need to check Docker Desktop file-sharing settings:

  1. Go to "Preferences" -> "Resources" -> "File sharing".
  2. If the directory with the desired file is missing, add a path to the directory containing your file.

Note! Do not add your root directory or any system directory to the file-sharing settings as it will load your CPU. The issue is described in Github, and this comment gives a workaround.

Storing SHA1 hash values in MySQL

So the length is between 10 16-bit chars, and 40 hex digits.

In any case decide the format you are going to store, and make the field a fixed size based on that format. That way you won't have any wasted space.

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

This is my response to the problem. My underscore version was 1.7 hence I could not use .findIndex.

So I manually got the index of item and replaced it. Here is the code for the same.

 var students = [ 
{id:1,fName:"Ajay", lName:"Singh", age:20, sex:"M" },
{id:2,fName:"Raj", lName:"Sharma", age:21, sex:"M" },
{id:3,fName:"Amar", lName:"Verma", age:22, sex:"M" },
{id:4,fName:"Shiv", lName:"Singh", age:22, sex:"M" }
               ]

Below method will replace the student with id:4 with more attributes in the object

function updateStudent(id) {
 var indexOfRequiredStudent = -1;
    _.each(students,function(student,index) {                    
      if(student.id === id) {                        
           indexOfRequiredStudent = index; return;      
      }});
 students[indexOfRequiredStudent] = _.extend(students[indexOfRequiredStudent],{class:"First Year",branch:"CSE"});           

}

With underscore 1.8 it will be simplified as we have methods _.findIndexOf.

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

Tomalak already gave you a correct answer, but I would like to add that most of the times when you would like to know the VBA code needed to do a certain action in the user interface it is a good idea to record a macro.

In this case click Record Macro on the developer tab of the Ribbon, freeze the top row and then stop recording. Excel will have the following macro recorded for you which also does the job:

With ActiveWindow
    .SplitColumn = 0
    .SplitRow = 1
End With
ActiveWindow.FreezePanes = True

make sounds (beep) with c++

cout << "\a";

In Xcode, After compiling, you have to run the executable by hand to hear the beep.

C# Copy a file to another location with a different name

File.Copy(@"C:\oldFile.txt", @"C:\newFile.txt", true);

Please do not forget to overwrite the previous file! Make sure you add the third param., by adding the third param, you allow the file to be overwritten. Else you could use a try catch for the exception.

Regards, G

How to open an existing project in Eclipse?

In Eclipse, try Project > Open Project and select the projects to be opened.

ERROR in Cannot find module 'node-sass'

In my case I had to also had to perform:

npm install sass-loader

To fix the problem

How to check if a string contains a specific text

You can use strpos() or stripos() to check if the string contain the given needle. It will return the position where it was found, otherwise will return FALSE.

Use the operators === or `!== to differ FALSE from 0 in PHP.

Spring MVC: Complex object as GET @RequestParam

I will add some short example from me.

The DTO class:

public class SearchDTO {
    private Long id[];

    public Long[] getId() {
        return id;
    }

    public void setId(Long[] id) {
        this.id = id;
    }
    // reflection toString from apache commons
    @Override
    public String toString() {
        return ReflectionToStringBuilder.toString(this, ToStringStyle.SHORT_PREFIX_STYLE);
    }
}

Request mapping inside controller class:

@RequestMapping(value="/handle", method=RequestMethod.GET)
@ResponseBody
public String handleRequest(SearchDTO search) {
    LOG.info("criteria: {}", search);
    return "OK";
}

Query:

http://localhost:8080/app/handle?id=353,234

Result:

[http-apr-8080-exec-7] INFO  c.g.g.r.f.w.ExampleController.handleRequest:59 - criteria: SearchDTO[id={353,234}]

I hope it helps :)

UPDATE / KOTLIN

Because currently I'm working a lot of with Kotlin if someone wants to define similar DTO the class in Kotlin should have the following form:

class SearchDTO {
    var id: Array<Long>? = arrayOf()

    override fun toString(): String {
        // to string implementation
    }
}

With the data class like this one:

data class SearchDTO(var id: Array<Long> = arrayOf())

the Spring (tested in Boot) returns the following error for request mentioned in answer:

"Failed to convert value of type 'java.lang.String[]' to required type 'java.lang.Long[]'; nested exception is java.lang.NumberFormatException: For input string: \"353,234\""

The data class will work only for the following request params form:

http://localhost:8080/handle?id=353&id=234

Be aware of this!

How to get child element by ID in JavaScript?

If jQuery is okay, you can use find(). It's basically equivalent to the way you are doing it right now.

$('#note').find('#textid');

You can also use jQuery selectors to basically achieve the same thing:

$('#note #textid');

Using these methods to get something that already has an ID is kind of strange, but I'm supplying these assuming it's not really how you plan on using it.

On a side note, you should know ID's should be unique in your webpage. If you plan on having multiple elements with the same "ID" consider using a specific class name.

Update 2020.03.10

It's a breeze to use native JS for this:

document.querySelector('#note #textid');

If you want to first find #note then #textid you have to check the first querySelector result. If it fails to match, chaining is no longer possible :(

var parent = document.querySelector('#note');
var child = parent ? parent.querySelector('#textid') : null;

How to find if element with specific id exists or not

You need to specify which object you're calling getElementById from. In this case you can use document. You also can't just call .value on any element directly. For example if the element is textbox .value will return the value, but if it's a div it will not have a value.

You also have a wrong condition, you're checking

if (myEle == null)

which you should change to

if (myEle != null)

var myEle = document.getElementById("myElement");
if(myEle != null) { 
    var myEleValue= myEle.value; 
}

How to add items to array in nodejs

Here is example which can give you some hints to iterate through existing array and add items to new array. I use UnderscoreJS Module to use as my utility file.

You can download from (https://npmjs.org/package/underscore)

$ npm install underscore

Here is small snippet to demonstrate how you can do it.

var _ = require("underscore");
var calendars = [1, "String", {}, 1.1, true],
    newArray = [];

_.each(calendars, function (item, index) {
    newArray.push(item);
});

console.log(newArray);

Is mongodb running?

Correct, closing the shell will stop MongoDB. Try using the --fork command line arg for the mongod process which makes it run as a daemon instead. I'm no Unix guru, but I'm sure there must be a way to then get it to auto start when the machine boots up.

e.g.

mongod --fork --logpath /var/log/mongodb.log --logappend

Check out the full documentation on Starting and Stopping Mongo.

Difference between "\n" and Environment.NewLine

Depends on the platform. On Windows it is actually "\r\n".

From MSDN:

A string containing "\r\n" for non-Unix platforms, or a string containing "\n" for Unix platforms.

Regex to accept alphanumeric and some special character in Javascript?

use:

/^[ A-Za-z0-9_@./#&+-]*$/

You can also use the character class \w to replace A-Za-z0-9_

Twitter Bootstrap 3, vertically center content

Option 1 is to use display:table-cell. You need to unfloat the Bootstrap col-* using float:none..

.center {
    display:table-cell;
    vertical-align:middle;
    float:none;
}

http://bootply.com/94394


Option 2 is display:flex to vertical align the row with flexbox:

.row.center {
   display: flex;
   align-items: center;
}

http://www.bootply.com/7rAuLpMCwr


Vertical centering is very different in Bootstrap 4. See this answer for Bootstrap 4 https://stackoverflow.com/a/41464397/171456

SASS - use variables across multiple files

How about writing some color-based class in a global sass file, thus we don't need to care where variables are. Just like the following:

// base.scss 
@import "./_variables.scss";

.background-color{
    background: $bg-color;
}

and then, we can use the background-color class in any file. My point is that I don't need to import variable.scss in any file, just use it.

How to create a dump with Oracle PL/SQL Developer?

EXP (export) and IMP (import) are the two tools you need. It's is better to try to run these on the command line and on the same machine.

It can be run from remote, you just need to setup you TNSNAMES.ORA correctly and install all the developer tools with the same version as the database. Without knowing the error message you are experiencing then I can't help you to get exp/imp to work.

The command to export a single user:

exp userid=dba/dbapassword OWNER=username DIRECT=Y FILE=filename.dmp

This will create the export dump file.

To import the dump file into a different user schema, first create the newuser in SQLPLUS:

SQL> create user newuser identified by 'password' quota unlimited users;

Then import the data:

imp userid=dba/dbapassword FILE=filename.dmp FROMUSER=username TOUSER=newusername

If there is a lot of data then investigate increasing the BUFFERS or look into expdp/impdp

Most common errors for exp and imp are setup. Check your PATH includes $ORACLE_HOME/bin, check $ORACLE_HOME is set correctly and check $ORACLE_SID is set

Symfony2 : How to get form validation errors after binding the request to the form

Translated Form Error Messages (Symfony2.1)

I have been struggling a lot to find this information so I think it's definitely worth adding a note on translation of form errors.

@Icode4food answer will return all errors of a form. However, the array that is returned does not take into account either message pluralization or translation.

You can modify the foreach loop of @Icode4food answer to have a combo:

  • Get all errors of a particular form
  • Return a translated error
  • Take pluralization into account if necessary

Here it is:

foreach ($form->getErrors() as $key => $error) {

   //If the message requires pluralization
    if($error->getMessagePluralization() !== null) {
        $errors[] = $this->container->get('translator')->transChoice(
            $error->getMessage(), 
            $error->getMessagePluralization(), 
            $error->getMessageParameters(), 
            'validators'
            );
    } 
    //Otherwise, we do a classic translation
    else {
        $errors[] = $this->container->get('translator')->trans(
            $error->getMessage(), 
            array(), 
            'validators'
            );
    }
}

This answer has been put together from 3 different posts:

How to change value of a request parameter in laravel

Use merge():

$request->merge([
    'user_id' => $modified_user_id_here,
]);

Simple! No need to transfer the entire $request->all() to another variable.