Is there a php echo/print equivalent in javascript

// usage: log('inside coolFunc',this,arguments);
// http://paulirish.com/2009/log-a-lightweight-wrapper-for-consolelog/
window.log = function(){
  log.history = log.history || [];   // store logs to an array for reference
  log.history.push(arguments);
  if(this.console){
    console.log( Array.prototype.slice.call(arguments) );
  }
};

Using window.log will allow you to perform the same action as console.log, but it checks if the browser you are using has the ability to use console.log first, so as not to error out for compatibility reasons (IE 6, etc.).

Multi-line string with extra space (preserved indentation)

Heredoc sounds more convenient for this purpose. It is used to send multiple commands to a command interpreter program like ex or cat

cat << EndOfMessage
This is line 1.
This is line 2.
Line 3.
EndOfMessage

The string after << indicates where to stop.

To send these lines to a file, use:

cat > $FILE <<- EOM
Line 1.
Line 2.
EOM

You could also store these lines to a variable:

read -r -d '' VAR << EOM
This is line 1.
This is line 2.
Line 3.
EOM

This stores the lines to the variable named VAR.

When printing, remember the quotes around the variable otherwise you won't see the newline characters.

echo "$VAR"

Even better, you can use indentation to make it stand out more in your code. This time just add a - after << to stop the tabs from appearing.

read -r -d '' VAR <<- EOM
    This is line 1.
    This is line 2.
    Line 3.
EOM

But then you must use tabs, not spaces, for indentation in your code.

How to use css style in php

I guess you have your css code in a database & you want to render a php file as a CSS. If that is the case...

In your html page:

<html>
<head>
   <!- head elements (Meta, title, etc) -->

   <!-- Link your php/css file -->
   <link rel="stylesheet" href="style.php" media="screen">
<head>

Then, within style.php file:

<?php
/*** set the content type header ***/
/*** Without this header, it wont work ***/
header("Content-type: text/css");


$font_family = 'Arial, Helvetica, sans-serif';
$font_size = '0.7em';
$border = '1px solid';
?>

table {
margin: 8px;
}

th {
font-family: <?=$font_family?>;
font-size: <?=$font_size?>;
background: #666;
color: #FFF;
padding: 2px 6px;
border-collapse: separate;
border: <?=$border?> #000;
}

td {
font-family: <?=$font_family?>;
font-size: <?=$font_size?>;
border: <?=$border?> #DDD;
}

Have fun!

Simplest way to display current month and year like "Aug 2016" in PHP?

Here is a simple and more update format of getting the data:

   $now = new \DateTime('now');
   $month = $now->format('m');
   $year = $now->format('Y');

PHP: How do I display the contents of a textfile on my page?

If you aren't looking to do anything to the stuff in the file, just display it, you can actually just include() it. include works for any file type, but of course it runs any php code it finds inside.

How to flush output after each `echo` call?

One thing that is not often mentionned is gzip compression that keeps turned ON because of details in various hosting environments.

Here is a modern approach, working with PHP-FPM as Fast CGI, which does not need .htaccess rewrite rule or environment variable :

In php.ini or .user.ini :

output_buffering = 0
zlib.output_compression = 0
implicit_flush = true
output_handler =

In PHP script :

header('Content-Encoding: none'); // Disable gzip compression
ob_end_flush(); // Stop buffer
ob_implicit_flush(1); // Implicit flush at each output command

See this comment on official PHP doc for ob_end_flush() need.

How to format font style and color in echo

Are you trying to echo out a style or an inline style? An inline style would be like

echo "<p style=\"font-color: #ff0000;\">text here</p>";

Echo newline in Bash prints literal \n

POSIX 7 on echo

http://pubs.opengroup.org/onlinepubs/9699919799/utilities/echo.html

-e is not defined and backslashes are implementation defined:

If the first operand is -n, or if any of the operands contain a <backslash> character, the results are implementation-defined.

unless you have an optional XSI extension.

So I recommend that you should use printf instead, which is well specified:

format operand shall be used as the format string described in XBD File Format Notation [...]

the File Format Notation:

\n <newline> Move the printing position to the start of the next line.

Also keep in mind that Ubuntu 15.10 and most distros implement echo both as:

a Bash built-in: help echo
a standalone executable: which echo

which can lead to some confusion.

How can I repeat a character in Bash?

Here's two interesting ways:

ubuntu@ubuntu:~$ yes = | head -10 | paste -s -d '' -
==========
ubuntu@ubuntu:~$ yes = | head -10 | tr -d "\n"
==========ubuntu@ubuntu:~$

Note these two are subtly different - The paste method ends in a new line. The tr method does not.

Echo off but messages are displayed

For me this issue was caused by the file encoding format being wrong. I used another editor and it was saved as UTF-8-BOM so the very first line I had was @echo off but there was a hidden character in the front of it.

So I changed the encoding to plain old ANSI text, and then the issue went away.

How to use shell commands in Makefile

With:

FILES = $(shell ls)

indented underneath all like that, it's a build command. So this expands $(shell ls), then tries to run the command FILES ....

If FILES is supposed to be a make variable, these variables need to be assigned outside the recipe portion, e.g.:

FILES = $(shell ls)
all:
        echo $(FILES)

Of course, that means that FILES will be set to "output from ls" before running any of the commands that create the .tgz files. (Though as Kaz notes the variable is re-expanded each time, so eventually it will include the .tgz files; some make variants have FILES := ... to avoid this, for efficiency and/or correctness.¹)

If FILES is supposed to be a shell variable, you can set it but you need to do it in shell-ese, with no spaces, and quoted:

all:
        FILES="$(shell ls)"

However, each line is run by a separate shell, so this variable will not survive to the next line, so you must then use it immediately:

        FILES="$(shell ls)"; echo $$FILES

This is all a bit silly since the shell will expand * (and other shell glob expressions) for you in the first place, so you can just:

        echo *

as your shell command.

Finally, as a general rule (not really applicable to this example): as esperanto notes in comments, using the output from ls is not completely reliable (some details depend on file names and sometimes even the version of ls; some versions of ls attempt to sanitize output in some cases). Thus, as l0b0 and idelic note, if you're using GNU make you can use $(wildcard) and $(subst ...) to accomplish everything inside make itself (avoiding any "weird characters in file name" issues). (In sh scripts, including the recipe portion of makefiles, another method is to use find ... -print0 | xargs -0 to avoid tripping over blanks, newlines, control characters, and so on.)

¹The GNU Make documentation notes further that POSIX make added ::= assignment in 2012. I have not found a quick reference link to a POSIX document for this, nor do I know off-hand which make variants support ::= assignment, although GNU make does today, with the same meaning as :=, i.e., do the assignment right now with expansion.

Note that VAR := $(shell command args...) can also be spelled VAR != command args... in several make variants, including all modern GNU and BSD variants as far as I know. These other variants do not have $(shell) so using VAR != command args... is superior in both being shorter and working in more variants.

Echo tab characters in bash script

Put your string between double quotes:

echo "[$res]"

How to change the output color of echo in Linux

Here there is a simple script to easily manage the text style in bash shell promt:

https://github.com/ferromauro/bash-palette

Import the code using:

source bash-palette.sh

Use the imported variable in echo command (use the -e option!):

echo -e ${PALETTE_GREEN}Color Green${PALETTE_RESET}

It is possible to combine more elements:

echo -e ${PALETTE_GREEN}${PALETTE_BLINK}${PALETTE_RED_U}Green Blinking Text over Red Background${PALETTE_RESET}

PHP Echo text Color

This is an old question, but no one responded to the question regarding centering text in a terminal.

/**
 * Centers a string of text in a terminal window
 *
 * @param string $text The text to center
 * @param string $pad_string If set, the string to pad with (eg. '=' for a nice header)
 *
 * @return string The padded result, ready to echo
 */
function center($text, $pad_string = ' ') {
    $window_size = (int) `tput cols`;
    return str_pad($text, $window_size, $pad_string, STR_PAD_BOTH)."\n";
}

echo center('foo');
echo center('bar baz', '=');

How does one output bold text in Bash?

The most compatible way of doing this is using tput to discover the right sequences to send to the terminal:

bold=$(tput bold)
normal=$(tput sgr0)

then you can use the variables $bold and $normal to format things:

echo "this is ${bold}bold${normal} but this isn't"

gives

this is bold but this isn't

How to echo in PHP, HTML tags

You have a variety of options. One would be to use PHP as the template engine it is:

<?php 
  // Draw the page
?>
<div>
  <h3><a href="#">First</a></h3>
  <div>Lorem ipsum dolor sit amet.</div>
</div>
<?php
  // Done drawing.
?>

Another would be to use single quotes, which let you leave double quotes unquoted and also support newlines in literals:

<?php
  echo '<div>
  <h3><a href="#">First</a></h3>
  <div>Lorem ipsum dolor sit amet.</div>
</div>';
?>

Another would be to use a HEREDOC, which leaves double quotes untouched, supports newlines, and also expands any variables inside:

<?php
  echo <<<EOS
<div>
  <h3><a href="#">First</a></h3>
  <div>Lorem ipsum dolor sit amet.</div>
</div>
EOS;
?>

How can I echo the whole content of a .html file in PHP?

Just use:

<?php
    include("/path/to/file.html");
?>

That will echo it as well. This also has the benefit of executing any PHP in the file.

If you need to do anything with the contents, use file_get_contents(),

For example,

<?php
    $pagecontents = file_get_contents("/path/to/file.html");

    echo str_replace("Banana", "Pineapple", $pagecontents);

?>

This doesn't execute code in that file, so be careful if you expect that to work.

I usually use:

include($_SERVER['DOCUMENT_ROOT']."/path/to/file/as/in/url.html");

as then I can move files without breaking the includes.

php - insert a variable in an echo string

$i = 1;

echo "<p class='paragraph{$i}'></p>"; 

$i++;

using batch echo with special characters

You can escape shell metacharacters with ^:

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

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

PHP to search within txt file and echo the whole line

Do it like this. This approach lets you search a file of any size (big size won't crash the script) and will return ALL lines that match the string you want.

<?php
$searchthis = "mystring";
$matches = array();

$handle = @fopen("path/to/inputfile.txt", "r");
if ($handle)
{
    while (!feof($handle))
    {
        $buffer = fgets($handle);
        if(strpos($buffer, $searchthis) !== FALSE)
            $matches[] = $buffer;
    }
    fclose($handle);
}

//show results:
print_r($matches);
?>

Note the way strpos is used with !== operator.

echo key and value of an array without and with loop

If you must not use a loop (why?), you could use array_walk,

function printer($v, $k) {
   echo "$k is at $v\n";
}

array_walk($page, "printer");

See http://www.ideone.com/aV5X6.

Echo a blank (empty) line to the console from a Windows batch file

Any of the below three options works for you:

echo[

echo(

echo.

For example:

@echo off
echo There will be a blank line below
echo[
echo Above line is blank
echo( 
echo The above line is also blank.
echo. 
echo The above line is also blank.

How can I align the columns of tables in Bash?

It's easier than you wonder.

If you are working with a separated by semicolon file and header too:

$ (head -n1 file.csv && sort file.csv | grep -v <header>) | column -s";" -t

If you are working with array (using tab as separator):

for((i=0;i<array_size;i++));
do

   echo stringarray[$i] $'\t' numberarray[$i] $'\t' anotherfieldarray[$i] >> tmp_file.csv

done;

cat file.csv | column -t

How do I print all POST results when a form is submitted?

How do I make a Windows batch script completely silent?

If you want that all normal output of your Batch script be silent (like in your example), the easiest way to do that is to run the Batch file with a redirection:

C:\Temp> test.bat >nul

This method does not require to modify a single line in the script and it still show error messages in the screen. To supress all the output, including error messages:

C:\Temp> test.bat >nul 2>&1

If your script have lines that produce output you want to appear in screen, perhaps will be simpler to add redirection to those lineas instead of all the lines you want to keep silent:

@ECHO OFF
SET scriptDirectory=%~dp0
COPY %scriptDirectory%test.bat %scriptDirectory%test2.bat
FOR /F %%f IN ('dir /B "%scriptDirectory%*.noext"') DO (
del "%scriptDirectory%%%f"
)
ECHO
REM Next line DO appear in the screen
ECHO Script completed >con

Antonio

How are echo and print different in PHP?

I think print() is slower than echo.

I like to use print() only for situations like:

 echo 'Doing some stuff... ';
 foo() and print("ok.\n") or print("error: " . getError() . ".\n");

Bash: Echoing a echo command with a variable in bash

echo "echo "we are now going to work with ${ser}" " >> $servfile

Escape all " within quotes with \. Do this with variables like \$servicetest too:

echo "echo \"we are now going to work with \${ser}\" " >> $servfile    
echo "read -p \"Please enter a service: \" ser " >> $servfile
echo "if [ \$servicetest > /dev/null ];then " >> $servfile

Add php variable inside echo statement as href link address?

This worked much better in my case.

HTML in PHP: <a href=".$link_address.">Link</a>

How can I echo HTML in PHP?

Try this:

<?php
    echo <<<HTML

    Your HTML tags here

HTML;
?>

How to echo JSON in PHP

Native JSON support has been included in PHP since 5.2 in the form of methods json_encode() and json_decode(). You would use the first to output a PHP variable in JSON.

Double quotes within php script echo

You can just forgo the quotes for alphanumeric attributes:

echo "<font color=red> XHTML is not a thing anymore. </font>";
echo "<div class=editorial-note> There, I said it. </div>";

Is perfectly valid in HTML, and though still shunned, absolutely en vogue since HTML5.

CAVEATS

It's only valid for mostly alphanumeric and dash combinations.
Never ever do this with user input appended to attributes (those need quoting and htmlspecialchars or some whitelisting).
See also: When the attribute value can remain unquoted in HTML5
In other news: <font> specifically is somewhat outdated however.

How can I suppress all output from a command using Bash?

Take a look at this example from The Linux Documentation Project:

3.6 Sample: stderr and stdout 2 file

This will place every output of a program to a file. This is suitable sometimes for cron entries, if you want a command to pass in absolute silence.
     rm -f $(find / -name core) &> /dev/null 

That said, you can use this simple redirection:

/path/to/command &>/dev/null

Better solution without exluding fields from Binding

You should not use your domain models in your views. ViewModels are the correct way to do it.

You need to map your domain model's necessary fields to viewmodel and then use this viewmodel in your controllers. This way you will have the necessery abstraction in your application.

If you never heard of viewmodels, take a look at this.

Bootstrap Modal Backdrop Remaining

The best and simple approach is by using the data-dismiss attribute. Basically the data-dismiss attribute will dismiss the modal and you won't see the backdrop remaining.

How to use data-dismiss attribute

All you need to do is adding the following at the place where you want to close your modal:

data-dismiss="modal"

For example, I have a button and when someone clicks the button it will close the modal.

<button class="btn btn-info float-right" onclick="foo()" data-dismiss="modal">Save changes</button>

You can also handle the JavaScript function on onClick and it will close the modal and also run the JavaScript function.

This is the best approach to do using the data-dismiss attribute.

Stop setInterval

_x000D_

var flasher_icon = function (obj) {_x000D_
    var classToToggle = obj.classToToggle;_x000D_
    var elem = obj.targetElem;_x000D_
    var oneTime = obj.speed;_x000D_
    var halfFlash = oneTime / 2;_x000D_
    var totalTime = obj.flashingTimes * oneTime;_x000D_
_x000D_
    var interval = setInterval(function(){_x000D_
        elem.addClass(classToToggle);_x000D_
        setTimeout(function() {_x000D_
            elem.removeClass(classToToggle);_x000D_
        }, halfFlash);_x000D_
    }, oneTime);_x000D_
_x000D_
    setTimeout(function() {_x000D_
        clearInterval(interval);_x000D_
    }, totalTime);_x000D_
};_x000D_
_x000D_
flasher_icon({_x000D_
    targetElem: $('#icon-step-1-v1'),_x000D_
    flashingTimes: 3,_x000D_
    classToToggle: 'flasher_icon',_x000D_
    speed: 500_x000D_
});

_x000D_

.steps-icon{_x000D_
    background: #d8d8d8;_x000D_
    color: #000;_x000D_
    font-size: 55px;_x000D_
    padding: 15px;_x000D_
    border-radius: 50%;_x000D_
    margin: 5px;_x000D_
    cursor: pointer;_x000D_
}_x000D_
.flasher_icon{_x000D_
  color: #fff;_x000D_
  background: #820000 !important;_x000D_
  padding-bottom: 15px !important;_x000D_
  padding-top: 15px !important;_x000D_
}

_x000D_

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet"> _x000D_
_x000D_
<i class="steps-icon material-icons active" id="icon-step-1-v1" title="" data-toggle="tooltip" data-placement="bottom" data-original-title="Origin Airport">alarm</i>

_x000D_

Server unable to read htaccess file, denying access to be safe

Every public folder makes the permission to 755. Problem solved.

To switch from vertical split to horizontal split fast in Vim

In VIM, take a look at the following to see different alternatives for what you might have done:

:help opening-window

For instance:

Ctrl-W s
Ctrl-W o
Ctrl-W v
Ctrl-W o
Ctrl-W s
...

repaint() in Java

You're doing things in the wrong order.

You need to first add all JComponents to the JFrame, and only then call pack() and then setVisible(true) on the JFrame

If you later added JComponents that could change the GUI's size you will need to call pack() again, and then repaint() on the JFrame after doing so.

Use the auto keyword in C++ STL

auto keyword is intended to use in such situation, it is absolutely safe. But unfortunately it available only in C++0x so you will have portability issues with it.

Get the list of stored procedures created and / or modified on a particular date?

You can try this query in any given SQL Server database:

SELECT 
    name,
    create_date,
    modify_date
FROM sys.procedures
WHERE create_date = '20120927'

which lists out the name, the creation and the last modification date - unfortunately, it doesn't record who created and/or modified the stored procedure in question.

How can I tell jackson to ignore a property for which I don't have control over the source code?

You can use Jackson Mixins. For example:

class YourClass {
  public int ignoreThis() { return 0; }    
}

With this Mixin

abstract class MixIn {
  @JsonIgnore abstract int ignoreThis(); // we don't need it!  
}

With this:

objectMapper.getSerializationConfig().addMixInAnnotations(YourClass.class, MixIn.class);

Edit:

Thanks to the comments, with Jackson 2.5+, the API has changed and should be called with objectMapper.addMixIn(Class<?> target, Class<?> mixinSource)

How to handle :java.util.concurrent.TimeoutException: android.os.BinderProxy.finalize() timed out after 10 seconds errors?

try {
    Class<?> c = Class.forName("java.lang.Daemons");
    Field maxField = c.getDeclaredField("MAX_FINALIZE_NANOS");
    maxField.setAccessible(true);
    maxField.set(null, Long.MAX_VALUE);
} catch (ClassNotFoundException e) {
    e.printStackTrace();
} catch (NoSuchFieldException e) {
    e.printStackTrace();
} catch (IllegalAccessException e) {
    e.printStackTrace();
}

How to subtract/add days from/to a date?

There is of course a lubridate solution for this:

library(lubridate)
date <- "2009-10-01"

ymd(date) - 5
# [1] "2009-09-26"

is the same as

ymd(date) - days(5)
# [1] "2009-09-26"

Other time formats could be:

ymd(date) - months(5)
# [1] "2009-05-01"

ymd(date) - years(5)
# [1] "2004-10-01"

ymd(date) - years(1) - months(2) - days(3)
# [1] "2008-07-29"

JQuery ajax call default timeout value

There doesn't seem to be a standardized default value. I have the feeling the default is 0, and the timeout event left totally dependent on browser and network settings.

For IE, there is a timeout property for XMLHTTPRequests here. It defaults to null, and it says the network stack is likely to be the first to time out (which will not generate an ontimeout event by the way).

How to create json by JavaScript for loop?

If you want a single JavaScript object such as the following:

{ uniqueIDofSelect: "uniqueID", optionValue: "2" }

(where option 2, "Absent", is the current selection) then the following code should produce it:

  var jsObj = null;
  var status = document.getElementsByName("status")[0];
  for (i = 0, i < status.options.length, ++i) {
     if (options[i].selected ) {
        jsObj = { uniqueIDofSelect: status.id, optionValue: options[i].value };
        break;
     }
  }

If you want an array of all such objects (not just the selected one), use michael's code but swap out status.options[i].text for status.id.

If you want a string that contains a JSON representation of the selected object, use this instead:

  var jsonStr = "";
  var status = document.getElementsByName("status")[0];
  for (i = 0, i < status.options.length, ++i) {
     if (options[i].selected ) {
        jsonStr = '{ '
                  + '"uniqueIDofSelect" : '
                  + '"' + status.id + '"'
                  + ", "
                  + '"optionValue" : '
                  + '"'+ options[i].value + '"'
                  + ' }';
        break;
     }
  }

JavaScript: get code to run every minute

You could use setInterval for this.

<script type="text/javascript">
function myFunction () {
    console.log('Executed!');
}

var interval = setInterval(function () { myFunction(); }, 60000);
</script>

Disable the timer by setting clearInterval(interval).

See this Fiddle: http://jsfiddle.net/p6NJt/2/

how to get file path from sd card in android

There are different Names of SD-Cards.

This Code check every possible Name (I don't guarantee that these are all names but the most are included)

It prefers the main storage.

 private String SDPath() {
    String sdcardpath = "";

    //Datas
    if (new File("/data/sdext4/").exists() && new File("/data/sdext4/").canRead()){
        sdcardpath = "/data/sdext4/";
    }
    if (new File("/data/sdext3/").exists() && new File("/data/sdext3/").canRead()){
        sdcardpath = "/data/sdext3/";
    }
    if (new File("/data/sdext2/").exists() && new File("/data/sdext2/").canRead()){
        sdcardpath = "/data/sdext2/";
    }
    if (new File("/data/sdext1/").exists() && new File("/data/sdext1/").canRead()){
        sdcardpath = "/data/sdext1/";
    }
    if (new File("/data/sdext/").exists() && new File("/data/sdext/").canRead()){
        sdcardpath = "/data/sdext/";
    }

    //MNTS

    if (new File("mnt/sdcard/external_sd/").exists() && new File("mnt/sdcard/external_sd/").canRead()){
        sdcardpath = "mnt/sdcard/external_sd/";
    }
    if (new File("mnt/extsdcard/").exists() && new File("mnt/extsdcard/").canRead()){
        sdcardpath = "mnt/extsdcard/";
    }
    if (new File("mnt/external_sd/").exists() && new File("mnt/external_sd/").canRead()){
        sdcardpath = "mnt/external_sd/";
    }
    if (new File("mnt/emmc/").exists() && new File("mnt/emmc/").canRead()){
        sdcardpath = "mnt/emmc/";
    }
    if (new File("mnt/sdcard0/").exists() && new File("mnt/sdcard0/").canRead()){
        sdcardpath = "mnt/sdcard0/";
    }
    if (new File("mnt/sdcard1/").exists() && new File("mnt/sdcard1/").canRead()){
        sdcardpath = "mnt/sdcard1/";
    }
    if (new File("mnt/sdcard/").exists() && new File("mnt/sdcard/").canRead()){
        sdcardpath = "mnt/sdcard/";
    }

    //Storages
    if (new File("/storage/removable/sdcard1/").exists() && new File("/storage/removable/sdcard1/").canRead()){
        sdcardpath = "/storage/removable/sdcard1/";
    }
    if (new File("/storage/external_SD/").exists() && new File("/storage/external_SD/").canRead()){
        sdcardpath = "/storage/external_SD/";
    }
    if (new File("/storage/ext_sd/").exists() && new File("/storage/ext_sd/").canRead()){
        sdcardpath = "/storage/ext_sd/";
    }
    if (new File("/storage/sdcard1/").exists() && new File("/storage/sdcard1/").canRead()){
        sdcardpath = "/storage/sdcard1/";
    }
    if (new File("/storage/sdcard0/").exists() && new File("/storage/sdcard0/").canRead()){
        sdcardpath = "/storage/sdcard0/";
    }
    if (new File("/storage/sdcard/").exists() && new File("/storage/sdcard/").canRead()){
        sdcardpath = "/storage/sdcard/";
    }
    if (sdcardpath.contentEquals("")){
        sdcardpath = Environment.getExternalStorageDirectory().getAbsolutePath();
    }

    Log.v("SDFinder","Path: " + sdcardpath);
    return sdcardpath;
}

Create a root password for PHPMyAdmin

Go tohttp://localhost/security/index.php
Select language, it redirects to http://localhost/security/xamppsecurity.php
You will find an option to change the password here

How to make function decorators and chain them together?

If you are not into long explanations, see Paolo Bergantino’s answer.

Decorator Basics

Python’s functions are objects

To understand decorators, you must first understand that functions are objects in Python. This has important consequences. Let’s see why with a simple example :

def shout(word="yes"):
    return word.capitalize()+"!"

print(shout())
# outputs : 'Yes!'

# As an object, you can assign the function to a variable like any other object 
scream = shout

# Notice we don't use parentheses: we are not calling the function,
# we are putting the function "shout" into the variable "scream".
# It means you can then call "shout" from "scream":

print(scream())
# outputs : 'Yes!'

# More than that, it means you can remove the old name 'shout',
# and the function will still be accessible from 'scream'

del shout
try:
    print(shout())
except NameError as e:
    print(e)
    #outputs: "name 'shout' is not defined"

print(scream())
# outputs: 'Yes!'

Keep this in mind. We’ll circle back to it shortly.

Another interesting property of Python functions is they can be defined inside another function!

def talk():

    # You can define a function on the fly in "talk" ...
    def whisper(word="yes"):
        return word.lower()+"..."

    # ... and use it right away!
    print(whisper())

# You call "talk", that defines "whisper" EVERY TIME you call it, then
# "whisper" is called in "talk". 
talk()
# outputs: 
# "yes..."

# But "whisper" DOES NOT EXIST outside "talk":

try:
    print(whisper())
except NameError as e:
    print(e)
    #outputs : "name 'whisper' is not defined"*
    #Python's functions are objects

Functions references

Okay, still here? Now the fun part...

You’ve seen that functions are objects. Therefore, functions:

can be assigned to a variable
can be defined in another function

That means that a function can return another function.

def getTalk(kind="shout"):

    # We define functions on the fly
    def shout(word="yes"):
        return word.capitalize()+"!"

    def whisper(word="yes") :
        return word.lower()+"...";

    # Then we return one of them
    if kind == "shout":
        # We don't use "()", we are not calling the function,
        # we are returning the function object
        return shout  
    else:
        return whisper

# How do you use this strange beast?

# Get the function and assign it to a variable
talk = getTalk()      

# You can see that "talk" is here a function object:
print(talk)
#outputs : <function shout at 0xb7ea817c>

# The object is the one returned by the function:
print(talk())
#outputs : Yes!

# And you can even use it directly if you feel wild:
print(getTalk("whisper")())
#outputs : yes...

There’s more!

If you can return a function, you can pass one as a parameter:

def doSomethingBefore(func): 
    print("I do something before then I call the function you gave me")
    print(func())

doSomethingBefore(scream)
#outputs: 
#I do something before then I call the function you gave me
#Yes!

Well, you just have everything needed to understand decorators. You see, decorators are “wrappers”, which means that they let you execute code before and after the function they decorate without modifying the function itself.

Handcrafted decorators

How you’d do it manually:

# A decorator is a function that expects ANOTHER function as parameter
def my_shiny_new_decorator(a_function_to_decorate):

    # Inside, the decorator defines a function on the fly: the wrapper.
    # This function is going to be wrapped around the original function
    # so it can execute code before and after it.
    def the_wrapper_around_the_original_function():

        # Put here the code you want to be executed BEFORE the original function is called
        print("Before the function runs")

        # Call the function here (using parentheses)
        a_function_to_decorate()

        # Put here the code you want to be executed AFTER the original function is called
        print("After the function runs")

    # At this point, "a_function_to_decorate" HAS NEVER BEEN EXECUTED.
    # We return the wrapper function we have just created.
    # The wrapper contains the function and the code to execute before and after. It’s ready to use!
    return the_wrapper_around_the_original_function

# Now imagine you create a function you don't want to ever touch again.
def a_stand_alone_function():
    print("I am a stand alone function, don't you dare modify me")

a_stand_alone_function() 
#outputs: I am a stand alone function, don't you dare modify me

# Well, you can decorate it to extend its behavior.
# Just pass it to the decorator, it will wrap it dynamically in 
# any code you want and return you a new function ready to be used:

a_stand_alone_function_decorated = my_shiny_new_decorator(a_stand_alone_function)
a_stand_alone_function_decorated()
#outputs:
#Before the function runs
#I am a stand alone function, don't you dare modify me
#After the function runs

Now, you probably want that every time you call a_stand_alone_function, a_stand_alone_function_decorated is called instead. That’s easy, just overwrite a_stand_alone_function with the function returned by my_shiny_new_decorator:

a_stand_alone_function = my_shiny_new_decorator(a_stand_alone_function)
a_stand_alone_function()
#outputs:
#Before the function runs
#I am a stand alone function, don't you dare modify me
#After the function runs

# That’s EXACTLY what decorators do!

Decorators demystified

The previous example, using the decorator syntax:

@my_shiny_new_decorator
def another_stand_alone_function():
    print("Leave me alone")

another_stand_alone_function()  
#outputs:  
#Before the function runs
#Leave me alone
#After the function runs

Yes, that’s all, it’s that simple. @decorator is just a shortcut to:

another_stand_alone_function = my_shiny_new_decorator(another_stand_alone_function)

Decorators are just a pythonic variant of the decorator design pattern. There are several classic design patterns embedded in Python to ease development (like iterators).

Of course, you can accumulate decorators:

def bread(func):
    def wrapper():
        print("</''''''\>")
        func()
        print("<\______/>")
    return wrapper

def ingredients(func):
    def wrapper():
        print("#tomatoes#")
        func()
        print("~salad~")
    return wrapper

def sandwich(food="--ham--"):
    print(food)

sandwich()
#outputs: --ham--
sandwich = bread(ingredients(sandwich))
sandwich()
#outputs:
#</''''''\>
# #tomatoes#
# --ham--
# ~salad~
#<\______/>

Using the Python decorator syntax:

@bread
@ingredients
def sandwich(food="--ham--"):
    print(food)

sandwich()
#outputs:
#</''''''\>
# #tomatoes#
# --ham--
# ~salad~
#<\______/>

The order you set the decorators MATTERS:

@ingredients
@bread
def strange_sandwich(food="--ham--"):
    print(food)

strange_sandwich()
#outputs:
##tomatoes#
#</''''''\>
# --ham--
#<\______/>
# ~salad~

Now: to answer the question...

As a conclusion, you can easily see how to answer the question:

# The decorator to make it bold
def makebold(fn):
    # The new function the decorator returns
    def wrapper():
        # Insertion of some code before and after
        return "<b>" + fn() + "</b>"
    return wrapper

# The decorator to make it italic
def makeitalic(fn):
    # The new function the decorator returns
    def wrapper():
        # Insertion of some code before and after
        return "<i>" + fn() + "</i>"
    return wrapper

@makebold
@makeitalic
def say():
    return "hello"

print(say())
#outputs: <b><i>hello</i></b>

# This is the exact equivalent to 
def say():
    return "hello"
say = makebold(makeitalic(say))

print(say())
#outputs: <b><i>hello</i></b>

You can now just leave happy, or burn your brain a little bit more and see advanced uses of decorators.

Taking decorators to the next level

Passing arguments to the decorated function

# It’s not black magic, you just have to let the wrapper 
# pass the argument:

def a_decorator_passing_arguments(function_to_decorate):
    def a_wrapper_accepting_arguments(arg1, arg2):
        print("I got args! Look: {0}, {1}".format(arg1, arg2))
        function_to_decorate(arg1, arg2)
    return a_wrapper_accepting_arguments

# Since when you are calling the function returned by the decorator, you are
# calling the wrapper, passing arguments to the wrapper will let it pass them to 
# the decorated function

@a_decorator_passing_arguments
def print_full_name(first_name, last_name):
    print("My name is {0} {1}".format(first_name, last_name))

print_full_name("Peter", "Venkman")
# outputs:
#I got args! Look: Peter Venkman
#My name is Peter Venkman

Decorating methods

One nifty thing about Python is that methods and functions are really the same. The only difference is that methods expect that their first argument is a reference to the current object (self).

That means you can build a decorator for methods the same way! Just remember to take self into consideration:

def method_friendly_decorator(method_to_decorate):
    def wrapper(self, lie):
        lie = lie - 3 # very friendly, decrease age even more :-)
        return method_to_decorate(self, lie)
    return wrapper


class Lucy(object):

    def __init__(self):
        self.age = 32

    @method_friendly_decorator
    def sayYourAge(self, lie):
        print("I am {0}, what did you think?".format(self.age + lie))

l = Lucy()
l.sayYourAge(-3)
#outputs: I am 26, what did you think?

If you’re making general-purpose decorator--one you’ll apply to any function or method, no matter its arguments--then just use *args, **kwargs:

def a_decorator_passing_arbitrary_arguments(function_to_decorate):
    # The wrapper accepts any arguments
    def a_wrapper_accepting_arbitrary_arguments(*args, **kwargs):
        print("Do I have args?:")
        print(args)
        print(kwargs)
        # Then you unpack the arguments, here *args, **kwargs
        # If you are not familiar with unpacking, check:
        # http://www.saltycrane.com/blog/2008/01/how-to-use-args-and-kwargs-in-python/
        function_to_decorate(*args, **kwargs)
    return a_wrapper_accepting_arbitrary_arguments

@a_decorator_passing_arbitrary_arguments
def function_with_no_argument():
    print("Python is cool, no argument here.")

function_with_no_argument()
#outputs
#Do I have args?:
#()
#{}
#Python is cool, no argument here.

@a_decorator_passing_arbitrary_arguments
def function_with_arguments(a, b, c):
    print(a, b, c)

function_with_arguments(1,2,3)
#outputs
#Do I have args?:
#(1, 2, 3)
#{}
#1 2 3 

@a_decorator_passing_arbitrary_arguments
def function_with_named_arguments(a, b, c, platypus="Why not ?"):
    print("Do {0}, {1} and {2} like platypus? {3}".format(a, b, c, platypus))

function_with_named_arguments("Bill", "Linus", "Steve", platypus="Indeed!")
#outputs
#Do I have args ? :
#('Bill', 'Linus', 'Steve')
#{'platypus': 'Indeed!'}
#Do Bill, Linus and Steve like platypus? Indeed!

class Mary(object):

    def __init__(self):
        self.age = 31

    @a_decorator_passing_arbitrary_arguments
    def sayYourAge(self, lie=-3): # You can now add a default value
        print("I am {0}, what did you think?".format(self.age + lie))

m = Mary()
m.sayYourAge()
#outputs
# Do I have args?:
#(<__main__.Mary object at 0xb7d303ac>,)
#{}
#I am 28, what did you think?

Passing arguments to the decorator

Great, now what would you say about passing arguments to the decorator itself?

This can get somewhat twisted, since a decorator must accept a function as an argument. Therefore, you cannot pass the decorated function’s arguments directly to the decorator.

Before rushing to the solution, let’s write a little reminder:

# Decorators are ORDINARY functions
def my_decorator(func):
    print("I am an ordinary function")
    def wrapper():
        print("I am function returned by the decorator")
        func()
    return wrapper

# Therefore, you can call it without any "@"

def lazy_function():
    print("zzzzzzzz")

decorated_function = my_decorator(lazy_function)
#outputs: I am an ordinary function

# It outputs "I am an ordinary function", because that’s just what you do:
# calling a function. Nothing magic.

@my_decorator
def lazy_function():
    print("zzzzzzzz")

#outputs: I am an ordinary function

It’s exactly the same. "my_decorator" is called. So when you @my_decorator, you are telling Python to call the function 'labelled by the variable "my_decorator"'.

This is important! The label you give can point directly to the decorator—or not.

Let’s get evil. ?

def decorator_maker():

    print("I make decorators! I am executed only once: "
          "when you make me create a decorator.")

    def my_decorator(func):

        print("I am a decorator! I am executed only when you decorate a function.")

        def wrapped():
            print("I am the wrapper around the decorated function. "
                  "I am called when you call the decorated function. "
                  "As the wrapper, I return the RESULT of the decorated function.")
            return func()

        print("As the decorator, I return the wrapped function.")

        return wrapped

    print("As a decorator maker, I return a decorator")
    return my_decorator

# Let’s create a decorator. It’s just a new function after all.
new_decorator = decorator_maker()       
#outputs:
#I make decorators! I am executed only once: when you make me create a decorator.
#As a decorator maker, I return a decorator

# Then we decorate the function

def decorated_function():
    print("I am the decorated function.")

decorated_function = new_decorator(decorated_function)
#outputs:
#I am a decorator! I am executed only when you decorate a function.
#As the decorator, I return the wrapped function

# Let’s call the function:
decorated_function()
#outputs:
#I am the wrapper around the decorated function. I am called when you call the decorated function.
#As the wrapper, I return the RESULT of the decorated function.
#I am the decorated function.

No surprise here.

Let’s do EXACTLY the same thing, but skip all the pesky intermediate variables:

def decorated_function():
    print("I am the decorated function.")
decorated_function = decorator_maker()(decorated_function)
#outputs:
#I make decorators! I am executed only once: when you make me create a decorator.
#As a decorator maker, I return a decorator
#I am a decorator! I am executed only when you decorate a function.
#As the decorator, I return the wrapped function.

# Finally:
decorated_function()    
#outputs:
#I am the wrapper around the decorated function. I am called when you call the decorated function.
#As the wrapper, I return the RESULT of the decorated function.
#I am the decorated function.

Let’s make it even shorter:

@decorator_maker()
def decorated_function():
    print("I am the decorated function.")
#outputs:
#I make decorators! I am executed only once: when you make me create a decorator.
#As a decorator maker, I return a decorator
#I am a decorator! I am executed only when you decorate a function.
#As the decorator, I return the wrapped function.

#Eventually: 
decorated_function()    
#outputs:
#I am the wrapper around the decorated function. I am called when you call the decorated function.
#As the wrapper, I return the RESULT of the decorated function.
#I am the decorated function.

Hey, did you see that? We used a function call with the "@" syntax! :-)

So, back to decorators with arguments. If we can use functions to generate the decorator on the fly, we can pass arguments to that function, right?

def decorator_maker_with_arguments(decorator_arg1, decorator_arg2):

    print("I make decorators! And I accept arguments: {0}, {1}".format(decorator_arg1, decorator_arg2))

    def my_decorator(func):
        # The ability to pass arguments here is a gift from closures.
        # If you are not comfortable with closures, you can assume it’s ok,
        # or read: https://stackoverflow.com/questions/13857/can-you-explain-closures-as-they-relate-to-python
        print("I am the decorator. Somehow you passed me arguments: {0}, {1}".format(decorator_arg1, decorator_arg2))

        # Don't confuse decorator arguments and function arguments!
        def wrapped(function_arg1, function_arg2) :
            print("I am the wrapper around the decorated function.\n"
                  "I can access all the variables\n"
                  "\t- from the decorator: {0} {1}\n"
                  "\t- from the function call: {2} {3}\n"
                  "Then I can pass them to the decorated function"
                  .format(decorator_arg1, decorator_arg2,
                          function_arg1, function_arg2))
            return func(function_arg1, function_arg2)

        return wrapped

    return my_decorator

@decorator_maker_with_arguments("Leonard", "Sheldon")
def decorated_function_with_arguments(function_arg1, function_arg2):
    print("I am the decorated function and only knows about my arguments: {0}"
           " {1}".format(function_arg1, function_arg2))

decorated_function_with_arguments("Rajesh", "Howard")
#outputs:
#I make decorators! And I accept arguments: Leonard Sheldon
#I am the decorator. Somehow you passed me arguments: Leonard Sheldon
#I am the wrapper around the decorated function. 
#I can access all the variables 
#   - from the decorator: Leonard Sheldon 
#   - from the function call: Rajesh Howard 
#Then I can pass them to the decorated function
#I am the decorated function and only knows about my arguments: Rajesh Howard

Here it is: a decorator with arguments. Arguments can be set as variable:

c1 = "Penny"
c2 = "Leslie"

@decorator_maker_with_arguments("Leonard", c1)
def decorated_function_with_arguments(function_arg1, function_arg2):
    print("I am the decorated function and only knows about my arguments:"
           " {0} {1}".format(function_arg1, function_arg2))

decorated_function_with_arguments(c2, "Howard")
#outputs:
#I make decorators! And I accept arguments: Leonard Penny
#I am the decorator. Somehow you passed me arguments: Leonard Penny
#I am the wrapper around the decorated function. 
#I can access all the variables 
#   - from the decorator: Leonard Penny 
#   - from the function call: Leslie Howard 
#Then I can pass them to the decorated function
#I am the decorated function and only know about my arguments: Leslie Howard

As you can see, you can pass arguments to the decorator like any function using this trick. You can even use *args, **kwargs if you wish. But remember decorators are called only once. Just when Python imports the script. You can't dynamically set the arguments afterwards. When you do "import x", the function is already decorated, so you can't change anything.

Let’s practice: decorating a decorator

Okay, as a bonus, I'll give you a snippet to make any decorator accept generically any argument. After all, in order to accept arguments, we created our decorator using another function.

We wrapped the decorator.

Anything else we saw recently that wrapped function?

Oh yes, decorators!

Let’s have some fun and write a decorator for the decorators:

def decorator_with_args(decorator_to_enhance):
    """ 
    This function is supposed to be used as a decorator.
    It must decorate an other function, that is intended to be used as a decorator.
    Take a cup of coffee.
    It will allow any decorator to accept an arbitrary number of arguments,
    saving you the headache to remember how to do that every time.
    """

    # We use the same trick we did to pass arguments
    def decorator_maker(*args, **kwargs):

        # We create on the fly a decorator that accepts only a function
        # but keeps the passed arguments from the maker.
        def decorator_wrapper(func):

            # We return the result of the original decorator, which, after all, 
            # IS JUST AN ORDINARY FUNCTION (which returns a function).
            # Only pitfall: the decorator must have this specific signature or it won't work:
            return decorator_to_enhance(func, *args, **kwargs)

        return decorator_wrapper

    return decorator_maker

It can be used as follows:

# You create the function you will use as a decorator. And stick a decorator on it :-)
# Don't forget, the signature is "decorator(func, *args, **kwargs)"
@decorator_with_args 
def decorated_decorator(func, *args, **kwargs): 
    def wrapper(function_arg1, function_arg2):
        print("Decorated with {0} {1}".format(args, kwargs))
        return func(function_arg1, function_arg2)
    return wrapper

# Then you decorate the functions you wish with your brand new decorated decorator.

@decorated_decorator(42, 404, 1024)
def decorated_function(function_arg1, function_arg2):
    print("Hello {0} {1}".format(function_arg1, function_arg2))

decorated_function("Universe and", "everything")
#outputs:
#Decorated with (42, 404, 1024) {}
#Hello Universe and everything

# Whoooot!

I know, the last time you had this feeling, it was after listening a guy saying: "before understanding recursion, you must first understand recursion". But now, don't you feel good about mastering this?

Best practices: decorators

Decorators were introduced in Python 2.4, so be sure your code will be run on >= 2.4.
Decorators slow down the function call. Keep that in mind.
You cannot un-decorate a function. (There are hacks to create decorators that can be removed, but nobody uses them.) So once a function is decorated, it’s decorated for all the code.
Decorators wrap functions, which can make them hard to debug. (This gets better from Python >= 2.5; see below.)

The functools module was introduced in Python 2.5. It includes the function functools.wraps(), which copies the name, module, and docstring of the decorated function to its wrapper.

(Fun fact: functools.wraps() is a decorator! ?)

# For debugging, the stacktrace prints you the function __name__
def foo():
    print("foo")

print(foo.__name__)
#outputs: foo

# With a decorator, it gets messy    
def bar(func):
    def wrapper():
        print("bar")
        return func()
    return wrapper

@bar
def foo():
    print("foo")

print(foo.__name__)
#outputs: wrapper

# "functools" can help for that

import functools

def bar(func):
    # We say that "wrapper", is wrapping "func"
    # and the magic begins
    @functools.wraps(func)
    def wrapper():
        print("bar")
        return func()
    return wrapper

@bar
def foo():
    print("foo")

print(foo.__name__)
#outputs: foo

How can the decorators be useful?

Now the big question: What can I use decorators for?

Seem cool and powerful, but a practical example would be great. Well, there are 1000 possibilities. Classic uses are extending a function behavior from an external lib (you can't modify it), or for debugging (you don't want to modify it because it’s temporary).

You can use them to extend several functions in a DRY’s way, like so:

def benchmark(func):
    """
    A decorator that prints the time a function takes
    to execute.
    """
    import time
    def wrapper(*args, **kwargs):
        t = time.clock()
        res = func(*args, **kwargs)
        print("{0} {1}".format(func.__name__, time.clock()-t))
        return res
    return wrapper


def logging(func):
    """
    A decorator that logs the activity of the script.
    (it actually just prints it, but it could be logging!)
    """
    def wrapper(*args, **kwargs):
        res = func(*args, **kwargs)
        print("{0} {1} {2}".format(func.__name__, args, kwargs))
        return res
    return wrapper


def counter(func):
    """
    A decorator that counts and prints the number of times a function has been executed
    """
    def wrapper(*args, **kwargs):
        wrapper.count = wrapper.count + 1
        res = func(*args, **kwargs)
        print("{0} has been used: {1}x".format(func.__name__, wrapper.count))
        return res
    wrapper.count = 0
    return wrapper

@counter
@benchmark
@logging
def reverse_string(string):
    return str(reversed(string))

print(reverse_string("Able was I ere I saw Elba"))
print(reverse_string("A man, a plan, a canoe, pasta, heros, rajahs, a coloratura, maps, snipe, percale, macaroni, a gag, a banana bag, a tan, a tag, a banana bag again (or a camel), a crepe, pins, Spam, a rut, a Rolo, cash, a jar, sore hats, a peon, a canal: Panama!"))

#outputs:
#reverse_string ('Able was I ere I saw Elba',) {}
#wrapper 0.0
#wrapper has been used: 1x 
#ablE was I ere I saw elbA
#reverse_string ('A man, a plan, a canoe, pasta, heros, rajahs, a coloratura, maps, snipe, percale, macaroni, a gag, a banana bag, a tan, a tag, a banana bag again (or a camel), a crepe, pins, Spam, a rut, a Rolo, cash, a jar, sore hats, a peon, a canal: Panama!',) {}
#wrapper 0.0
#wrapper has been used: 2x
#!amanaP :lanac a ,noep a ,stah eros ,raj a ,hsac ,oloR a ,tur a ,mapS ,snip ,eperc a ,)lemac a ro( niaga gab ananab a ,gat a ,nat a ,gab ananab a ,gag a ,inoracam ,elacrep ,epins ,spam ,arutaroloc a ,shajar ,soreh ,atsap ,eonac a ,nalp a ,nam A

Of course the good thing with decorators is that you can use them right away on almost anything without rewriting. DRY, I said:

@counter
@benchmark
@logging
def get_random_futurama_quote():
    from urllib import urlopen
    result = urlopen("http://subfusion.net/cgi-bin/quote.pl?quote=futurama").read()
    try:
        value = result.split("<br><b><hr><br>")[1].split("<br><br><hr>")[0]
        return value.strip()
    except:
        return "No, I'm ... doesn't!"


print(get_random_futurama_quote())
print(get_random_futurama_quote())

#outputs:
#get_random_futurama_quote () {}
#wrapper 0.02
#wrapper has been used: 1x
#The laws of science be a harsh mistress.
#get_random_futurama_quote () {}
#wrapper 0.01
#wrapper has been used: 2x
#Curse you, merciful Poseidon!

Python itself provides several decorators: property, staticmethod, etc.

Django uses decorators to manage caching and view permissions.
Twisted to fake inlining asynchronous functions calls.

This really is a large playground.

OpenCV NoneType object has no attribute shape

I had this issue with cap = cv2.VideoCapture(0). I changed this to cap = cv2.VideoCapture(1) and then it worked. Since it wasn't linked to the right webcam it was returning nothing. Maybe this will help good luck.

how to set mongod --dbpath

Windows environment, local machine. I had an error

[js] Error: couldn't connect to server 127.0.0.1:27017, connection attempt failed: SocketException: 
Error connecting to 127.0.0.1:27017 :: caused by :: 
No connection could be made because the target machine actively refused it. :

After some back and forth attempts I decided

to check Windows "Task Manager". I noticed that MongoDB process is stopped.
I made it run. Everything starts working as expected.

What is the best way to get the count/length/size of an iterator?

If all you have is the iterator, then no, there is no "better" way. If the iterator comes from a collection you could as that for size.

Keep in mind that Iterator is just an interface for traversing distinct values, you would very well have code such as this

    new Iterator<Long>() {
        final Random r = new Random();
        @Override
        public boolean hasNext() {
            return true;
        }

        @Override
        public Long next() {
            return r.nextLong();
        }

        @Override
        public void remove() {
            throw new IllegalArgumentException("Not implemented");
        }
    };

    new Iterator<BigInteger>() {
        BigInteger next = BigInteger.ZERO;

        @Override
        public boolean hasNext() {
            return true;
        }

        @Override
        public BigInteger next() {
            BigInteger current = next;
            next = next.add(BigInteger.ONE);
            return current;
        }

        @Override
        public void remove() {
            throw new IllegalArgumentException("Not implemented");
        }
    };

How to Get a Specific Column Value from a DataTable?

Datatables have a .Select method, which returns a rows array according to the criteria you specify. Something like this:

Dim oRows() As DataRow

oRows = dtCountries.Select("CountryName = '" & userinput & "'")

If oRows.Count = 0 Then
   ' No rows found
Else
   ' At least one row found. Could be more than one
End If

Of course, if userinput contains ' character, it would raise an exception (like if you query the database). You should escape the ' characters (I use a function to do that).

How should I choose an authentication library for CodeIgniter?

I've come across Flexi Auth (http://haseydesign.com/flexi-auth/). It looks very promising, and I've started using it. It has wonderfful features. Fully integrates with CI, and comes with two different library files, in which one is very heavy loaded with all the functions and the other one contains only the validations.

One of the best is that the newly registered member gets temporary access for a given amount of time on the site, until they click on the link from their email and activate.

How do I include a Perl module that's in a different directory?

'use lib' can also take a single string value...

#!/usr/bin/perl
use lib '<relative-path>';
use <your lib>;

SQL Statement using Where clause with multiple values

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

If you are using parametrized Stored procedure:

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

What is the purpose of Order By 1 in SQL select statement?

This:

ORDER BY 1

...is known as an "Ordinal" - the number stands for the column based on the number of columns defined in the SELECT clause. In the query you provided, it means:

ORDER BY A.PAYMENT_DATE

It's not a recommended practice, because:

It's not obvious/explicit
If the column order changes, the query is still valid so you risk ordering by something you didn't intend

How to skip the first n rows in sql query

In Faircom SQL (which is a pseudo MySQL), i can do this in a super simple SQL Statement, just as follows:

SELECT SKIP 10 * FROM TABLE ORDER BY Id

Obviously you can just replace 10 with any declared variable of your desire.

I don't have access to MS SQL or other platforms, but I'll be really surprised MS SQL doesn't support something like this.

Gson - convert from Json to a typed ArrayList<T>

You have a string like this.

"[{"id":2550,"cityName":"Langkawi","hotelName":"favehotel Cenang Beach - Langkawi","hotelId":"H1266070"},
{"id":2551,"cityName":"Kuala Lumpur","hotelName":"Metro Hotel Bukit Bintang","hotelId":"H835758"}]"

Then you can covert it to ArrayList via Gson like

var hotels = Gson().fromJson(historyItem.hotels, Array<HotelInfo>::class.java).toList()

Your HotelInfo class should like this.

import com.squareup.moshi.Json

data class HotelInfo(

    @Json(name="cityName")
    val cityName: String? = null,

    @Json(name="id")
    val id: Int? = null,

    @Json(name="hotelId")
    val hotelId: String? = null,

    @Json(name="hotelName")
    val hotelName: String? = null
)

Can Android Studio be used to run standard Java projects?

I have been able to do it using following steps:

Open Android Studio and select 'Import Project'.
Browse to your project folder in the browse window and select it.

'uint32_t' identifier not found error

I had to run project in VS2010 and I could not introduce any modifications in the code. My solution was to install vS2013 and in VS2010 point VC++ Directories->IncludeDirectories to Program Files(x86)\Microsoft Visual Studio 12.0\VC\include. Then my project compiled without any issues.

Do I need to pass the full path of a file in another directory to open()?

You have to specify the path that you are working on:

source = '/home/test/py_test/'
for root, dirs, filenames in os.walk(source):
    for f in filenames:
        print f
        fullpath = os.path.join(source, f)
        log = open(fullpath, 'r')

Mac SQLite editor

Razorsql can handle many kinds of databases.

How to pause a YouTube player when hiding the iframe?

A more concise, elegant, and secure answer: add “?enablejsapi=1” to the end of the video URL, then construct and stringify an ordinary object representing the pause command:

const YouTube_pause_video_command_JSON = JSON.stringify(Object.create(null, {
    "event": {
        "value": "command",
        "enumerable": true
    },
    "func": {
        "value": "pauseVideo",
        "enumerable": true
    }
}));

Use the Window.postMessage method to send the resulting JSON string to the embedded video document:

// |iframe_element| is defined elsewhere.
const video_URL = iframe_element.getAttributeNS(null, "src");
iframe_element.contentWindow.postMessage(YouTube_pause_video_command_JSON, video_URL);

Make sure you specify the video URL for the Window.postMessage method’s targetOrigin argument to ensure that your messages won’t be sent to any unintended recipient.

Using PHP with Socket.io

We are now in 2018 and hoola, there is a way to implement WS and WAMPServer on php. It 's Called Ratchet.

Comments in Android Layout xml

click the

ctrl+shift+/

and write anything you and evrything will be in comments

JavaScript replace/regex

In terms of pattern interpretation, there's no difference between the following forms:

/pattern/
new RegExp("pattern")

If you want to replace a literal string using the replace method, I think you can just pass a string instead of a regexp to replace.

Otherwise, you'd have to escape any regexp special characters in the pattern first - maybe like so:

function reEscape(s) {
    return s.replace(/([.*+?^$|(){}\[\]])/mg, "\\$1");
}

// ...

var re = new RegExp(reEscape(pattern), "mg");
this.markup = this.markup.replace(re, value);

Python function attributes - uses and abuses

I was always of the assumption that the only reason this was possible was so there was a logical place to put a doc-string or other such stuff. I know if I used it for any production code it'd confuse most who read it.

How to insert an element after another element in JavaScript without using a library?

referenceNode.parentNode.insertBefore(newNode, referenceNode.nextSibling);

Where referenceNode is the node you want to put newNode after. If referenceNode is the last child within its parent element, that's fine, because referenceNode.nextSibling will be null and insertBefore handles that case by adding to the end of the list.

So:

function insertAfter(newNode, referenceNode) {
    referenceNode.parentNode.insertBefore(newNode, referenceNode.nextSibling);
}

You can test it using the following snippet:

_x000D_

function insertAfter(referenceNode, newNode) {_x000D_
  referenceNode.parentNode.insertBefore(newNode, referenceNode.nextSibling);_x000D_
}_x000D_
_x000D_
var el = document.createElement("span");_x000D_
el.innerHTML = "test";_x000D_
var div = document.getElementById("foo");_x000D_
insertAfter(div, el);

_x000D_

<div id="foo">Hello</div>

_x000D_

Iterate through object properties

Object.keys(obj).forEach(key =>
  console.log(`key=${key} value=${obj[key]}`)
);

How to delete an element from an array in C#

If you want to remove all instances of 4 without needing to know the index:

LINQ: (.NET Framework 3.5)

int[] numbers = { 1, 3, 4, 9, 2 };
int numToRemove = 4;
numbers = numbers.Where(val => val != numToRemove).ToArray();

Non-LINQ: (.NET Framework 2.0)

static bool isNotFour(int n)
{
    return n != 4;
}

int[] numbers = { 1, 3, 4, 9, 2 };
numbers = Array.FindAll(numbers, isNotFour).ToArray();

If you want to remove just the first instance:

LINQ: (.NET Framework 3.5)

int[] numbers = { 1, 3, 4, 9, 2, 4 };
int numToRemove = 4;
int numIndex = Array.IndexOf(numbers, numToRemove);
numbers = numbers.Where((val, idx) => idx != numIndex).ToArray();

Non-LINQ: (.NET Framework 2.0)

int[] numbers = { 1, 3, 4, 9, 2, 4 };
int numToRemove = 4;
int numIdx = Array.IndexOf(numbers, numToRemove);
List<int> tmp = new List<int>(numbers);
tmp.RemoveAt(numIdx);
numbers = tmp.ToArray();

Edit: Just in case you hadn't already figured it out, as Malfist pointed out, you need to be targetting the .NET Framework 3.5 in order for the LINQ code examples to work. If you're targetting 2.0 you need to reference the Non-LINQ examples.

On Selenium WebDriver how to get Text from Span Tag

Pythonic way to get text from Span tags:

driver.find_element_by_xpath("//*[@id='customSelect_3']/.//span[contains(@class,'selectLabel clear')]").text

git pull from master into the development branch

The steps you listed will work, but there's a longer way that gives you more options:

git checkout dmgr2      # gets you "on branch dmgr2"
git fetch origin        # gets you up to date with origin
git merge origin/master

The fetch command can be done at any point before the merge, i.e., you can swap the order of the fetch and the checkout, because fetch just goes over to the named remote (origin) and says to it: "gimme everything you have that I don't", i.e., all commits on all branches. They get copied to your repository, but named origin/branch for any branch named branch on the remote.

At this point you can use any viewer (git log, gitk, etc) to see "what they have" that you don't, and vice versa. Sometimes this is only useful for Warm Fuzzy Feelings ("ah, yes, that is in fact what I want") and sometimes it is useful for changing strategies entirely ("whoa, I don't want THAT stuff yet").

Finally, the merge command takes the given commit, which you can name as origin/master, and does whatever it takes to bring in that commit and its ancestors, to whatever branch you are on when you run the merge. You can insert --no-ff or --ff-only to prevent a fast-forward, or merge only if the result is a fast-forward, if you like.

When you use the sequence:

git checkout dmgr2
git pull origin master

the pull command instructs git to run git fetch, and then the moral equivalent of git merge origin/master. So this is almost the same as doing the two steps by hand, but there are some subtle differences that probably are not too concerning to you. (In particular the fetch step run by pull brings over only origin/master, and it does not update the ref in your repo:¹ any new commits winds up referred-to only by the special FETCH_HEAD reference.)

If you use the more-explicit git fetch origin (then optionally look around) and then git merge origin/master sequence, you can also bring your own local master up to date with the remote, with only one fetch run across the network:

git fetch origin
git checkout master
git merge --ff-only origin/master
git checkout dmgr2
git merge --no-ff origin/master

for instance.

¹This second part has been changed—I say "fixed"—in git 1.8.4, which now updates "remote branch" references opportunistically. (It was, as the release notes say, a deliberate design decision to skip the update, but it turns out that more people prefer that git update it. If you want the old remote-branch SHA-1, it defaults to being saved in, and thus recoverable from, the reflog. This also enables a new git 1.9/2.0 feature for finding upstream rebases.)

How to amend a commit without changing commit message (reusing the previous one)?

git commit -C HEAD --amend will do what you want. The -C option takes the metadata from another commit.

How to unzip a list of tuples into individual lists?

Use zip(*list):

>>> l = [(1,2), (3,4), (8,9)]
>>> list(zip(*l))
[(1, 3, 8), (2, 4, 9)]

The zip() function pairs up the elements from all inputs, starting with the first values, then the second, etc. By using *l you apply all tuples in l as separate arguments to the zip() function, so zip() pairs up 1 with 3 with 8 first, then 2 with 4 and 9. Those happen to correspond nicely with the columns, or the transposition of l.

zip() produces tuples; if you must have mutable list objects, just map() the tuples to lists or use a list comprehension to produce a list of lists:

map(list, zip(*l))          # keep it a generator
[list(t) for t in zip(*l)]  # consume the zip generator into a list of lists

Auto-indent in Notepad++

Try to save the file before, then it will indent.

Replace CRLF using powershell

Alternative solution that won't append a spurious CR-LF:

$original_file ='C:\Users\abc\Desktop\File\abc.txt'
$text = [IO.File]::ReadAllText($original_file) -replace "`r`n", "`n"
[IO.File]::WriteAllText($original_file, $text)

Remove characters from a String in Java

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

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

How to wait for all threads to finish, using ExecutorService?

This is my solution, based in "AdamSkywalker" tip, and it works

package frss.main;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class TestHilos {

    void procesar() {
        ExecutorService es = Executors.newFixedThreadPool(4);
        List<Runnable> tasks = getTasks();
        CompletableFuture<?>[] futures = tasks.stream().map(task -> CompletableFuture.runAsync(task, es)).toArray(CompletableFuture[]::new);
        CompletableFuture.allOf(futures).join();
        es.shutdown();

        System.out.println("FIN DEL PROCESO DE HILOS");
    }

    private List<Runnable> getTasks() {
        List<Runnable> tasks = new ArrayList<Runnable>();

        Hilo01 task1 = new Hilo01();
        tasks.add(task1);

        Hilo02 task2 = new Hilo02();
        tasks.add(task2);
        return tasks;
    }

    private class Hilo01 extends Thread {

        @Override
        public void run() {
            System.out.println("HILO 1");
        }

    }

    private class Hilo02 extends Thread {

        @Override
        public void run() {
            try {
                sleep(2000);
            }
            catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("HILO 2");
        }

    }


    public static void main(String[] args) {
        TestHilos test = new TestHilos();
        test.procesar();
    }
}

Disabled href tag

CSS only: this removes the link from the href.

.disable { 
    pointer-events: none; 
    cursor: default; 
}

Re-enabling window.alert in Chrome

In Chrome Browser go to setting , clear browsing history and then reload the page

Controlling Maven final name of jar artifact

At the package stage, the plugin allows configuration of the imported file names via file mapping:

maven-ear-plugin

http://maven.apache.org/plugins/maven-ear-plugin/examples/customize-file-name-mapping.html

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-ear-plugin</artifactId>
    <version>2.7</version>
    <configuration>
       [...]
        <fileNameMapping>full</fileNameMapping>
    </configuration>
</plugin>

http://maven.apache.org/plugins/maven-war-plugin/war-mojo.html#outputFileNameMapping

If you have configured your version to be 'testing' via a profile or something, this would work for a war package:

maven-war-plugin

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-war-plugin</artifactId>
    <version>2.2</version>
    <configuration>
        <encoding>UTF-8</encoding>                        
        <outputFileNameMapping>@{groupId}@-@{artifactId}@-@{baseVersion}@@{dashClassifier?}@.@{extension}@</outputFileNameMapping>
    </configuration>
</plugin>

Calculate age based on date of birth

There is a simple way to find the date from any birthdate by using substr of PHP

$birth_date = '15.03.2014';
$date = substr($birth_date, 0, 2);
echo $date;

Which will just simply give you the output date of that birth date.

In this case, that will be 15.

See substr of PHP for more...

Find and replace specific text characters across a document with JS

ECMAScript 2015+ approach

Pitfalls when solving this task

This seems like an easy task, but you have to take care of several things:

Simply replacing the entire HTML kills all DOM functionality, like event listeners
Replacing the HTML may also replace <script> or <style> contents, or HTML tags or attributes, which is not always desired
Changing the HTML may result in an xss attack
You may want to replace attributes like title and alt (in a controlled manner) as well

Guarding against xss attacks generally can’t be solved by using the approaches below. E.g. if a fetch call reads a URL from somewhere on the page, then sends a request to that URL, the functions below won’t stop that, since this scenario is inherently unsafe.

Replacing the text contents of all elements

This basically selects all elements that contain normal text, goes through their child nodes — among those are also text nodes —, seeks those text nodes out and replaces their contents.

You can optionally specify a different root target, e.g. replaceOnDocument(/€/g, "$", { target: someElement });; by default, the <body> is chosen.

const replaceOnDocument = (pattern, string, {target = document.body} = {}) => {
  // Handle `string` — see the last section
  [
    target,
    ...target.querySelectorAll("*:not(script):not(noscript):not(style)")
  ].forEach(({childNodes: [...nodes]}) => nodes
    .filter(({nodeType}) => nodeType === document.TEXT_NODE)
    .forEach((textNode) => textNode.textContent = textNode.textContent.replace(pattern, string)));
};

replaceOnDocument(/€/g, "$");

Replacing text nodes, element attributes and properties

Now, this is a little more complex: you need to check three cases: whether a node is a text node, whether it’s an element and its attribute should be replaced, or whether it’s an element and its property should be replaced. A replacer object provides methods for text nodes and for elements.

Before replacing attributes and properties, the replacer needs to check whether the element has a matching attribute; otherwise new attributes get created, undesirably. It also needs to check whether the targeted property is a string, since only strings can be replaced, or whether the matching property to the targeted attribute is not a function, since this may lead to an xss attack.

In the example below, you can see how to use the extended features: in the optional third argument, you may add an attrs property and a props property, which is an iterable (e.g. an array) each, for the attributes to be replaced and the properties to be replaced, respectively.

You’ll also notice that this snippet uses flatMap. If that’s not supported, use a polyfill or replace it by the reduce–concat, or map–reduce–concat construct, as seen in the linked documentation.

const replaceOnDocument = (() => {
    const replacer = {
      [document.TEXT_NODE](node, pattern, string){
        node.textContent = node.textContent.replace(pattern, string);
      },
      [document.ELEMENT_NODE](node, pattern, string, {attrs, props} = {}){
        attrs.forEach((attr) => {
          if(typeof node[attr] !== "function" && node.hasAttribute(attr)){
            node.setAttribute(attr, node.getAttribute(attr).replace(pattern, string));
          }
        });
        props.forEach((prop) => {
          if(typeof node[prop] === "string" && node.hasAttribute(prop)){
            node[prop] = node[prop].replace(pattern, string);
          }
        });
      }
    };

    return (pattern, string, {target = document.body, attrs: [...attrs] = [], props: [...props] = []} = {}) => {
      // Handle `string` — see the last section
      [
        target,
        ...[
          target,
          ...target.querySelectorAll("*:not(script):not(noscript):not(style)")
        ].flatMap(({childNodes: [...nodes]}) => nodes)
      ].filter(({nodeType}) => replacer.hasOwnProperty(nodeType))
        .forEach((node) => replacer[node.nodeType](node, pattern, string, {
          attrs,
          props
        }));
    };
})();

replaceOnDocument(/€/g, "$", {
  attrs: [
    "title",
    "alt",
    "onerror" // This will be ignored
  ],
  props: [
    "value" // Changing an `<input>`’s `value` attribute won’t change its current value, so the property needs to be accessed here
  ]
});

Replacing with HTML entities

If you need to make it work with HTML entities like , the above approaches will just literally produce the string , since that’s an HTML entity and will only work when assigning .innerHTML or using related methods.

So let’s solve it by passing the input string to something that accepts an HTML string: a new, temporary HTMLDocument. This is created by the DOMParser’s parseFromString method; in the end we read its documentElement’s textContent:

string = new DOMParser().parseFromString(string, "text/html").documentElement.textContent;

If you want to use this, choose one of the approaches above, depending on whether or not you want to replace HTML attributes and DOM properties in addition to text; then simply replace the comment // Handle `string` — see the last section by the above line.

Now you can use replaceOnDocument(/Güterzug/g, "Güterzug");.

NB: If you don’t use the string handling code, you may also remove the { } around the arrow function body.

Note that this parses HTML entities but still disallows inserting actual HTML tags, since we’re reading only the textContent. This is also safe against most cases of xss: since we’re using parseFromString and the page’s document isn’t affected, no <script> gets downloaded and no onerror handler gets executed.

You should also consider using \xAD instead of  directly in your JavaScript string, if it turns out to be simpler.

Why Would I Ever Need to Use C# Nested Classes

Maybe this is a good example of when to use nested classes?

// ORIGINAL
class ImageCacheSettings { }
class ImageCacheEntry { }
class ImageCache
{
    ImageCacheSettings mSettings;
    List<ImageCacheEntry> mEntries;
}

And:

// REFACTORED
class ImageCache
{
    Settings mSettings;
    List<Entry> mEntries;

    class Settings {}
    class Entry {}
}

PS: I've not taken into account which access modifiers should be applied (private, protected, public, internal)

How to copy a directory structure but only include certain files (using windows batch files)

An alternate solution that copies one file at a time and does not require ROBOCOPY:

@echo off
setlocal enabledelayedexpansion

set "SOURCE_DIR=C:\Source"
set "DEST_DIR=C:\Destination"
set FILENAMES_TO_COPY=data.zip info.txt

for /R "%SOURCE_DIR%" %%F IN (%FILENAMES_TO_COPY%) do (
    if exist "%%F" (
        set FILE_DIR=%%~dpF
        set FILE_INTERMEDIATE_DIR=!FILE_DIR:%SOURCE_DIR%=!
        xcopy /E /I /Y "%%F" "%DEST_DIR%!FILE_INTERMEDIATE_DIR!"
    )
)

The outer for statement generates any possible path combination of subdirectory in SOURCE_DIR and name in FILENAMES_TO_COPY. For each existing file xcopy is invoked. FILE_INTERMEDIATE_DIR holds the file's subdirectory path within SOURCE_DIR which needs to be created in DEST_DIR.

Registering for Push Notifications in Xcode 8/Swift 3.0?

First, listen to user notification status, i.e., registerForRemoteNotifications() to get APNs device token;
Second, request authorization. When being authorized by the user, deviceToken will be sent to the listener, the AppDelegate;
Third, report the device token to your server.

extension AppDelegate {
    /// 1. ?? deviceToken
    UIApplication.shared.registerForRemoteNotifications()

    /// 2. ???????????(????? token)
    static func registerRemoteNotifications() {
        if #available(iOS 10, *) {
            let uc = UNUserNotificationCenter.current()
            uc.delegate = UIApplication.shared.delegate as? AppDelegate
            uc.requestAuthorization(options: [.alert, .badge, .sound]) { (granted, error) in
                if let error = error { // ???????,????? aps-certificate,? error ??? nil
                    print("UNUserNotificationCenter ??????, \(error)")
                }
                DispatchQueue.main.async {
                    onAuthorization(granted: granted)
                }
            }
        } else {
            let app = UIApplication.shared
            app.registerUserNotificationSettings(UIUserNotificationSettings(types: [.badge, .sound, .alert], categories: nil)) // ??????
        }
    }

    // ? app.registerUserNotificationSettings() ???????????????,????????
    func application(_ app: UIApplication, didRegister notificationSettings: UIUserNotificationSettings) {
        // ???????,????????
        // a ???????,???app????,?????????
        // b ??????????,??????????,???????,??token,?????
        // c ??badge, alert?sound ?,notificationSettings.types.rawValue ?? 0 ? app.isRegisteredForRemoteNotifications ??,????token,??????(?????????????),???types??????
        // ???????,????????,?? isRegisteredForRemoteNotifications ??? false
       onAuthorization(granted: app.isRegisteredForRemoteNotifications)
    }

    static func onAuthorization(granted: Bool) {
        guard granted else { return }
        // do something
    }
}

extension AppDelegate {
    func application(_ app: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
        //
    }

    // ?????? token,??? aps-certificate ??????? token,???????????? token
    func application(_ app: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
        //
    }
}

keytool error Keystore was tampered with, or password was incorrect

I have solve this issue by using default password "changeit".

MySQLDump one INSERT statement for each data row

In newer versions change was made to the flags: from the documentation:

--extended-insert, -e

Write INSERT statements using multiple-row syntax that includes several VALUES lists. This results in a smaller dump file and speeds up inserts when the file is reloaded.

--opt

This option, enabled by default, is shorthand for the combination of --add-drop-table --add-locks --create-options --disable-keys --extended-insert --lock-tables --quick --set-charset. It gives a fast dump operation and produces a dump file that can be reloaded into a MySQL server quickly.

Because the --opt option is enabled by default, you only specify its converse, the --skip-opt to turn off several default settings. See the discussion of mysqldump option groups for information about selectively enabling or disabling a subset of the options affected by --opt.

--skip-extended-insert

Turn off extended-insert

Oracle select most recent date record

i think i'd try with MAX something like this:

SELECT staff_id, max( date ) from owner.table group by staff_id

then link in your other columns:

select staff_id, site_id, pay_level, latest
from owner.table, 
(   SELECT staff_id, max( date ) latest from owner.table group by staff_id ) m
where m.staff_id = staff_id
and m.latest = date

How to read data from excel file using c#

CSharpJExcel for reading Excel 97-2003 files (XLS), ExcelPackage for reading Excel 2007/2010 files (Office Open XML format, XLSX), and ExcelDataReader that seems to have the ability to handle both formats

Good luck!

How do I convert from a string to an integer in Visual Basic?

You can try these:

Dim valueStr as String = "10"

Dim valueIntConverted as Integer = CInt(valueStr)

Another example:

Dim newValueConverted as Integer = Val("100")

How to read the Stock CPU Usage data

More about "load average" showing CPU load over 1 minute, 5 minutes and 15 minutes

Linux, Mac, and other Unix-like systems display “load average” numbers. These numbers tell you how busy your system’s CPU, disk, and other resources are. They’re not self-explanatory at first, but it’s easy to become familiar with them.

WIKI: example, one can interpret a load average of "1.73 0.60 7.98" on a single-CPU system as:

during the last minute, the system was overloaded by 73% on average (1.73 runnable processes, so that 0.73 processes had to wait for a turn for a single CPU system on average).
during the last 5 minutes, the CPU was idling 40% of the time on average.
during the last 15 minutes, the system was overloaded 698% on average (7.98 runnable processes, so that 6.98 processes had to wait for a turn for a single CPU system on average) if dual core mean: 798% - 200% = 598%.

You probably have a system with multiple CPUs or a multi-core CPU. The load average numbers work a bit differently on such a system. For example, if you have a load average of 2 on a single-CPU system, this means your system was overloaded by 100 percent — the entire period of time, one process was using the CPU while one other process was waiting. On a system with two CPUs, this would be complete usage — two different processes were using two different CPUs the entire time. On a system with four CPUs, this would be half usage — two processes were using two CPUs, while two CPUs were sitting idle.

To understand the load average number, you need to know how many CPUs your system has. A load average of 6.03 would indicate a system with a single CPU was massively overloaded, but it would be fine on a computer with 8 CPUs.

more info : Link

When can I use a forward declaration?

Lakos distinguishes between class usage

in-name-only (for which a forward declaration is sufficient) and
in-size (for which the class definition is needed).

I've never seen it pronounced more succinctly :)

"Fade" borders in CSS

You can specify gradients for colours in certain circumstances in CSS3, and of course borders can be set to a colour, so you should be able to use a gradient as a border colour. This would include the option of specifying a transparent colour, which means you should be able to achieve the effect you're after.

However, I've never seen it used, and I don't know how well supported it is by current browsers. You'll certainly need to accept that at least some of your users won't be able to see it.

A quick google turned up these two pages which should help you on your way:

Hope that helps.

<meta charset="utf-8"> vs <meta http-equiv="Content-Type">

<meta charset="utf-8"> was introduced with/for HTML5.

As mentioned in the documentation, both are valid. However, <meta charset="utf-8"> is only for HTML5 (and easier to type/remember).

In due time, the old style is bound to become deprecated in the near future. I'd stick to the new <meta charset="utf-8">.

There's only one way, but up. In tech's case, that's phasing out the old (really, REALLY fast)

Documentation: HTML meta charset Attribute—W3Schools

Best way to represent a fraction in Java?

Please make it an immutable type! The value of a fraction doesn't change - a half doesn't become a third, for example. Instead of setDenominator, you could have withDenominator which returns a new fraction which has the same numerator but the specified denominator.

Life is much easier with immutable types.

Overriding equals and hashcode would be sensible too, so it can be used in maps and sets. Outlaw Programmer's points about arithmetic operators and string formatting are good too.

As a general guide, have a look at BigInteger and BigDecimal. They're not doing the same thing, but they're similar enough to give you good ideas.

What is the default maximum heap size for Sun's JVM from Java SE 6?

With JDK, You can also use jinfo to connect to the JVM for the <PROCESS_ID> in question and get the value for MaxHeapSize:

jinfo -flag MaxHeapSize <PROCESS_ID>

How to handle query parameters in angular 2

In Angular 6, I found this simpler way:

navigate(["/yourpage", { "someParamName": "paramValue"}]);

Then in the constructor or in ngInit you can directly use:

let value = this.route.snapshot.params.someParamName;

Difference between the System.Array.CopyTo() and System.Array.Clone()

object[] myarray = new object[] { "one", 2, "three", 4, "really big number", 2324573984927361 };

//create shallow copy by CopyTo
//You have to instantiate your new array first
object[] myarray2 = new object[myarray.Length];
//but then you can specify how many members of original array you would like to copy 
myarray.CopyTo(myarray2, 0);

//create shallow copy by Clone
object[] myarray1;
//here you don't need to instantiate array, 
//but all elements of the original array will be copied
myarray1 = myarray.Clone() as object[];

//if not sure that we create a shalow copy lets test it
myarray[0] = 0;
Console.WriteLine(myarray[0]);// print 0
Console.WriteLine(myarray1[0]);//print "one"
Console.WriteLine(myarray2[0]);//print "one"

the source

How do you scroll up/down on the console of a Linux VM

Another alternative, that might be already installed on your system is to use GNU screen :

# This starts screen which adds basic window management in terminals
screen

# This starts the copy mode you can use to scroll
<CTRL-A> [

# Now use the arrows to scroll

# To exit copy mode, do
<ESC>

See man screen for much more useful options (multiple windows, ...)...

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

Do you want to switch to this??

switch(x) {
    case 12:
    case 16:
    case 19: 
        //Do something
        break;
    default:
        //Do nothing or something else..
        break;
}

How to change the font on the TextView?

Best practice ever

TextViewPlus.java:

public class TextViewPlus extends TextView {
    private static final String TAG = "TextView";

    public TextViewPlus(Context context) {
        super(context);
    }

    public TextViewPlus(Context context, AttributeSet attrs) {
        super(context, attrs);
        setCustomFont(context, attrs);
    }

    public TextViewPlus(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        setCustomFont(context, attrs);
    }

    private void setCustomFont(Context ctx, AttributeSet attrs) {
        TypedArray a = ctx.obtainStyledAttributes(attrs, R.styleable.TextViewPlus);
        String customFont = a.getString(R.styleable.TextViewPlus_customFont);
        setCustomFont(ctx, customFont);
        a.recycle();
    }

    public boolean setCustomFont(Context ctx, String asset) {
        Typeface typeface = null;
        try {
            typeface = Typeface.createFromAsset(ctx.getAssets(), asset);
        } catch (Exception e) {
            Log.e(TAG, "Unable to load typeface: "+e.getMessage());
            return false;
        }

        setTypeface(typeface);
        return true;
    }
}

attrs.xml: (Where to place res/values)

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="TextViewPlus">
        <attr name="customFont" format="string"/>
    </declare-styleable>
</resources>

How to use:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:foo="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <com.mypackage.TextViewPlus
        android:id="@+id/textViewPlus1"
        android:layout_height="match_parent"
        android:layout_width="match_parent"
        android:text="@string/showingOffTheNewTypeface"
        foo:customFont="my_font_name_regular.otf">
    </com.mypackage.TextViewPlus>
</LinearLayout>

Hope this will help you.

How to get MAC address of client using PHP?

echo GetMAC();

function GetMAC(){
    ob_start();
    system('getmac');
    $Content = ob_get_contents();
    ob_clean();
    return substr($Content, strpos($Content,'\\')-20, 17);
}

Above will basically execute the getmac program and parse its console-output, resulting to MAC-address of the server (and/or where ever PHP is installed and running on).

Difference between getContext() , getApplicationContext() , getBaseContext() and "this"

From this docs

I understood that you should use:

Try using the context-application instead of a context-activity

How to execute a Ruby script in Terminal?

Although its too late to answer this question, but still for those guys who came here to see the solution of same problem just like me and didn't get a satisfactory answer on this page, The reason is that you don't have your file in the form of .rb extension. You most probably have it in simple text mode. Let me elaborate. Binding up the whole solution on the page, here you go (assuming you filename is abc.rb or at least you created abc):

Type in terminal window:

cd ~/to/the/program/location
ruby abc.rb

and you are done

If the following error occurs

ruby: No such file or directory -- abc.rb (LoadError)

Then go to the directory in which you have the abc file, rename it as abc.rb Close gedit and reopen the file abc.rb. Apply the same set of commands and success!

How do I clear a C++ array?

Assuming a C-style array a of size N, with elements of a type implicitly convertible from 0, the following sets all the elements to values constructed from 0.

std::fill(a, a+N, 0);

Note that this is not the same as "emptying" or "clearing".

Edit: Following james Kanze's suggestion, in C++11 you could use the more idiomatic alternative

std::fill( std::begin( a ), std::end( a ), 0 );

In the absence of C++11, you could roll out your own solution along these lines:

template <typename T, std::size_t N> T* end_(T(&arr)[N]) { return arr + N; }

template <typename T, std::size_t N> T* begin_(T(&arr)[N]) { return arr; }

std::fill( begin_( a ), end_( a ), 0 );

How to use MD5 in javascript to transmit a password

You might want to check out this page: http://pajhome.org.uk/crypt/md5/

However, if protecting the password is important, you should really be using something like SHA256 (MD5 is not cryptographically secure iirc). Even more, you might want to consider using TLS and getting a cert so you can use https.

How to force HTTPS using a web.config file

You need URL Rewrite module, preferably v2 (I have no v1 installed, so cannot guarantee that it will work there, but it should).

Here is an example of such web.config -- it will force HTTPS for ALL resources (using 301 Permanent Redirect):

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <rewrite>
            <rules>
                <clear />
                <rule name="Redirect to https" stopProcessing="true">
                    <match url=".*" />
                    <conditions>
                        <add input="{HTTPS}" pattern="off" ignoreCase="true" />
                    </conditions>
                    <action type="Redirect" url="https://{HTTP_HOST}{REQUEST_URI}" redirectType="Permanent" appendQueryString="false" />
                </rule>
            </rules>
        </rewrite>
    </system.webServer>
</configuration>

P.S. This particular solution has nothing to do with ASP.NET/PHP or any other technology as it's done using URL rewriting module only -- it is processed at one of the initial/lower levels -- before request gets to the point where your code gets executed.

How to parse a String containing XML in Java and retrieve the value of the root node?

One of the above answer states to convert XML String to bytes which is not needed. Instead you can can use InputSource and supply it with StringReader.

String xmlStr = "<message>HELLO!</message>";
DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document doc = db.parse(new InputSource(new StringReader(xmlStr)));
System.out.println(doc.getFirstChild().getNodeValue());

java.lang.OutOfMemoryError: bitmap size exceeds VM budget - Android

Following points really helped me a lot. There might be other points too, but these are very crucial:

Use application context(instead of activity.this) where ever possible.
Stop and release your threads in onPause() method of activity
Release your views / callbacks in onDestroy() method of activity

How to get the id of the element clicked using jQuery

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

$(document).on('click','span',function(e){
    console.log(e.target.id)
})

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

$('#main_div').on('click','span',function(e){
    console.log(e.target.id)
})

is better than binding to the document for instance.

This question may help you understand

Direct vs. Delegated - jQuery .on()

Adding a column to a data.frame

If I understand the question correctly, you want to detect when the h_no doesn't increase and then increment the class. (I'm going to walk through how I solved this problem, there is a self-contained function at the end.)

Working

We only care about the h_no column for the moment, so we can extract that from the data frame:

> h_no <- data$h_no

We want to detect when h_no doesn't go up, which we can do by working out when the difference between successive elements is either negative or zero. R provides the diff function which gives us the vector of differences:

> d.h_no <- diff(h_no)
> d.h_no
 [1]  1  1  1 -3  1  1  1  1  1  1 -6  1  1  1

Once we have that, it is a simple matter to find the ones that are non-positive:

> nonpos <- d.h_no <= 0
> nonpos
 [1] FALSE FALSE FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE FALSE
[13] FALSE FALSE

In R, TRUE and FALSE are basically the same as 1 and 0, so if we get the cumulative sum of nonpos, it will increase by 1 in (almost) the appropriate spots. The cumsum function (which is basically the opposite of diff) can do this.

> cumsum(nonpos)
 [1] 0 0 0 1 1 1 1 1 1 1 2 2 2 2

But, there are two problems: the numbers are one too small; and, we are missing the first element (there should be four in the first class).

The first problem is simply solved: 1+cumsum(nonpos). And the second just requires adding a 1 to the front of the vector, since the first element is always in class 1:

 > classes <- c(1, 1 + cumsum(nonpos))
 > classes
  [1] 1 1 1 1 2 2 2 2 2 2 2 3 3 3 3

Now, we can attach it back onto our data frame with cbind (by using the class= syntax, we can give the column the class heading):

 > data_w_classes <- cbind(data, class=classes)

And data_w_classes now contains the result.

Final result

We can compress the lines together and wrap it all up into a function to make it easier to use:

classify <- function(data) {
   cbind(data, class=c(1, 1 + cumsum(diff(data$h_no) <= 0)))
}

Or, since it makes sense for the class to be a factor:

classify <- function(data) {
   cbind(data, class=factor(c(1, 1 + cumsum(diff(data$h_no) <= 0))))
}

You use either function like:

> classified <- classify(data) # doesn't overwrite data
> data <- classify(data) # data now has the "class" column

(This method of solving this problem is good because it avoids explicit iteration, which is generally recommend for R, and avoids generating lots of intermediate vectors and list etc. And also it's kinda neat how it can be written on one line :) )

how to remove pagination in datatable

You should include "bPaginate": false, into the configuration object you pass to your constructor parameters. As seen here: http://datatables.net/release-datatables/examples/basic_init/filter_only.html

Email address validation in C# MVC 4 application: with or without using Regex

Why not just use the EmailAttribute?

[Email(ErrorMessage = "Bad email")]
public string Email { get; set; }

jQuery: Check if special characters exists in string

If you really want to check for all those special characters, it's easier to use a regular expression:

var str = $('#Search').val();
if(/^[a-zA-Z0-9- ]*$/.test(str) == false) {
    alert('Your search string contains illegal characters.');
}

The above will only allow strings consisting entirely of characters on the ranges a-z, A-Z, 0-9, plus the hyphen an space characters. A string containing any other character will cause the alert.

python - if not in list

How about this?

for item in mylist:
    if item in checklist:
        pass
    else:
       # do something
       print item

Get Current date in epoch from Unix shell script

echo $(($(date +%s) / 60 / 60 / 24))

TypeError: document.getElementbyId is not a function

JavaScript is case-sensitive. The b in getElementbyId should be capitalized.

var content = document.getElementById("edit").innerHTML;

How do I get cURL to not show the progress bar?

In curl version 7.22.0 on Ubuntu and 7.24.0 on OSX the solution to not show progress but to show errors is to use both -s (--silent) and -S (--show-error) like so:

curl -sS http://google.com > temp.html

This works for both redirected output > /some/file, piped output | less and outputting directly to the terminal for me.

Update: Since curl 7.67.0 there is a new option --no-progress-meter which does precisely this and nothing else, see clonejo's answer for more details.

Extract parameter value from url using regular expressions

Why dont you take the string and split it

Example on the url

var url = "http://www.youtube.com/watch?p=DB852818BF378DAC&v=1q-k-uN73Gk"

you can do a split as

var params = url.split("?")[1].split("&");

You will get array of strings with params as name value pairs with "=" as the delimiter.

Run cURL commands from Windows console

it should work perfectly fine if you would download it from --http://curl.haxx.se/dlwiz/?type=bin&os=Win64&flav=MinGW64 -- FOR 64BIT Win7/XP OR from http://curl.haxx.se/dlwiz/?type=bin&os=Win32&flav=-&ver=2000%2FXP --- FOR 32BIT Win7/XP just extract the files to c:/Windows and run it from cmd

C:\Users\WaQas>curl -v google.com
* About to connect() to google.com port 80 (#0)
*   Trying 173.194.35.105...
* connected
* Connected to google.com (173.194.35.105) port 80 (#0)
> GET / HTTP/1.1
> User-Agent: curl/7.28.1
> Host: google.com
> Accept: */*
>
* HTTP 1.0, assume close after body
< HTTP/1.0 301 Moved Permanently
< Location: http://www.google.com/
< Content-Type: text/html; charset=UTF-8
< Date: Tue, 05 Feb 2013 00:50:57 GMT
< Expires: Thu, 07 Mar 2013 00:50:57 GMT
< Cache-Control: public, max-age=2592000
< Server: gws
< Content-Length: 219
< X-XSS-Protection: 1; mode=block
< X-Frame-Options: SAMEORIGIN
< X-Cache: MISS from LHR-CacheMARA3
< X-Cache-Lookup: HIT from LHR-CacheMARA3:64003
< Connection: close
<
<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">
<TITLE>301 Moved</TITLE></HEAD><BODY>
<H1>301 Moved</H1>
The document has moved
<A HREF="http://www.google.com/">here</A>.
</BODY></HTML>
* Closing connection #0

Two Divs next to each other, that then stack with responsive change

today this kind of thing can be done by using display:flex;

https://jsfiddle.net/suunyz3e/1435/

html:

  <div class="container flex-direction">
      <div class="div1">
        <span>Div One</span>
      </div>
      <div class="div2">
        <span>Div Two</span>
      </div>
  </div>

css:

.container{
  display:inline-flex;
  flex-wrap:wrap;
  border:1px solid black;
}
.flex-direction{
  flex-direction:row;
}
.div1{
  border-right:1px solid black;
  background-color:#727272;
  width:165px;
  height:132px;
}

.div2{
  background-color:#fff;
  width:314px;
  height:132px;
}

span{
  font-size:16px;
    font-weight:bold;
    display: block;
    line-height: 132px;
    text-align: center;
}

@media screen and (max-width: 500px) {
  .flex-direction{
  flex-direction:column;
  }
.div1{
  width:202px;
  height:131px;
  border-right:none;
  border-bottom:1px solid black;
  }
  .div2{
    width:202px;
    height:107px;
  }
  .div2 span{
    line-height:107px;
  }

}

How can I upgrade specific packages using pip and a requirements file?

First make sure you have checked the most voted answer.

I'm not sure if it's exactly your problem, but in my case, I wasn't able to upgrade Django to 1.2.4 - I was always finishing with 1.2.3 version, so I uninstalled Django with:

<virtualenv>/bin/pip uninstall Django

Then I removed <virtualenv>/build/Django directory and finally I installed the proper version with:

<virtualenv>/bin/pip install Django

SQL Server loop - how do I loop through a set of records

this way we can iterate into table data.

DECLARE @_MinJobID INT
DECLARE @_MaxJobID INT
CREATE  TABLE #Temp (JobID INT)

INSERT INTO #Temp SELECT * FROM DBO.STRINGTOTABLE(@JobID,',')
SELECT @_MinJID = MIN(JobID),@_MaxJID = MAX(JobID)  FROM #Temp

    WHILE @_MinJID <= @_MaxJID
    BEGIN

        INSERT INTO Mytable        
        (        
            JobID,        
        )        

        VALUES        
        (        
            @_MinJobID,        
        ) 

        SET @_MinJID = @_MinJID + 1;
    END

DROP TABLE #Temp

STRINGTOTABLE is user define function which will parse comma separated data and return table. thanks

Android Studio - Failed to notify project evaluation listener error

I've resolved this issue by cleaning all the Gradle cache, stoping the Gradle Daemon process, and created a new build successfully using the following command. Make sure your current directory is android.

rm -rf ~/.gradle/caches && ./gradlew --stop && ./gradlew cleanBuildCache && ./gradlew bundleRelease

I'm using React Native. So I've added following in my scripts in package.json,

"build-android": "rm -rf ~/.gradle/caches && cd android && ./gradlew --stop && ./gradlew cleanBuildCache && ./gradlew bundleRelease && cd ..",

Difference between "\n" and Environment.NewLine

You might get into trouble when you try to display multi-line message separated with "\r\n".

It is always a good practice to do things in a standard way, and use Environment.NewLine

axios post request to send form data

In my case, the problem was that the format of the FormData append operation needed the additional "options" parameter filling in to define the filename thus:

var formData = new FormData();
formData.append(fieldName, fileBuffer, {filename: originalName});

I'm seeing a lot of complaints that axios is broken, but in fact the root cause is not using form-data properly. My versions are:

"axios": "^0.21.1",
"form-data": "^3.0.0",

On the receiving end I am processing this with multer, and the original problem was that the file array was not being filled - I was always getting back a request with no files parsed from the stream.

In addition, it was necessary to pass the form-data header set in the axios request:

        const response = await axios.post(getBackendURL() + '/api/Documents/' + userId + '/createDocument', formData, {
        headers: formData.getHeaders()
    });

My entire function looks like this:

async function uploadDocumentTransaction(userId, fileBuffer, fieldName, originalName) {
    var formData = new FormData();
    formData.append(fieldName, fileBuffer, {filename: originalName});

    try {
        const response = await axios.post(
            getBackendURL() + '/api/Documents/' + userId + '/createDocument',
            formData,
            {
                headers: formData.getHeaders()
            }
        );

        return response;
    } catch (err) {
        // error handling
    }
}

The value of the "fieldName" is not significant, unless you have some receiving end processing that needs it.

How do I find out where login scripts live?

The default location for logon scripts is the netlogon share of a domain controller. On the server this is located:

%SystemRoot%'SYSVOL'sysvol''scripts

It can presumably be changes from this default but I've never met anyone that had a reason to.

To get list of domain controllers programatically see this article: http://www.microsoft.com/technet/scriptcenter/resources/qanda/dec04/hey1216.mspx

How to filter wireshark to see only dns queries that are sent/received from/by my computer?

I would go through the packet capture and see if there are any records that I know I should be seeing to validate that the filter is working properly and to assuage any doubts.

That said, please try the following filter and see if you're getting the entries that you think you should be getting:

dns and ip.dst==159.25.78.7 or dns and ip.src==159.57.78.7

How to add image in a TextView text?

com/xyz/customandroid/ TextViewWithImages .java:

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

import android.content.Context;
import android.text.Spannable;
import android.text.style.ImageSpan;
import android.util.AttributeSet;
import android.util.Log;
import android.widget.TextView;

public class TextViewWithImages extends TextView {

    public TextViewWithImages(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }
    public TextViewWithImages(Context context, AttributeSet attrs) {
        super(context, attrs);
    }
    public TextViewWithImages(Context context) {
        super(context);
    }
    @Override
    public void setText(CharSequence text, BufferType type) {
        Spannable s = getTextWithImages(getContext(), text);
        super.setText(s, BufferType.SPANNABLE);
    }

    private static final Spannable.Factory spannableFactory = Spannable.Factory.getInstance();

    private static boolean addImages(Context context, Spannable spannable) {
        Pattern refImg = Pattern.compile("\\Q[img src=\\E([a-zA-Z0-9_]+?)\\Q/]\\E");
        boolean hasChanges = false;

        Matcher matcher = refImg.matcher(spannable);
    while (matcher.find()) {
        boolean set = true;
        for (ImageSpan span : spannable.getSpans(matcher.start(), matcher.end(), ImageSpan.class)) {
            if (spannable.getSpanStart(span) >= matcher.start()
             && spannable.getSpanEnd(span) <= matcher.end()
               ) {
                spannable.removeSpan(span);
            } else {
                set = false;
                break;
            }
        }
        String resname = spannable.subSequence(matcher.start(1), matcher.end(1)).toString().trim();
        int id = context.getResources().getIdentifier(resname, "drawable", context.getPackageName());
        if (set) {
            hasChanges = true;
            spannable.setSpan(  new ImageSpan(context, id),
                                matcher.start(),
                                matcher.end(),
                                Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
                             );
        }
    }

        return hasChanges;
    }
    private static Spannable getTextWithImages(Context context, CharSequence text) {
        Spannable spannable = spannableFactory.newSpannable(text);
        addImages(context, spannable);
        return spannable;
    }
}

Use:

in res/layout/mylayout.xml:

            <com.xyz.customandroid.TextViewWithImages
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textColor="#FFFFFF00"
                android:text="@string/can_try_again"
                android:textSize="12dip"
                style=...
                />

Note that if you place TextViewWithImages.java in some location other than com/xyz/customandroid/, you also must change the package name, com.xyz.customandroid above.

in res/values/strings.xml:

<string name="can_try_again">Press [img src=ok16/] to accept or [img src=retry16/] to retry</string>

where ok16.png and retry16.png are icons in the res/drawable/ folder

How can I get the latest JRE / JDK as a zip file rather than EXE or MSI installer?

You can download a portable Zulu .zip archive from Azul Systems, which are builds of OpenJDK for Windows, Linux (RHEL, SUSE, Debian, Ubuntu, CentOS) and Mac OS X.

Zulu is a certified build of OpenJDK that is fully compliant with the Java SE standard. Zulu is 100% open source and freely downloadable. Now Java developers, system administrators and end users can enjoy the full benefits of open source Java with deployment flexibility and control over upgrade timing.

More technical information on different JVMs (including Zulu) with their architectures and OS support here.

How can I configure Logback to log different levels for a logger to different destinations?

Solution based on configuration only, with a ThresoldFilter and LevelFilters to keep things really simple to understand :

<configuration>
    <appender name="STDERR" class="ch.qos.logback.core.ConsoleAppender">
        <target>System.err</target>
        <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
          <level>WARN</level>
        </filter>
        <encoder>
            <pattern>%date %level [%thread] %logger %msg%n</pattern>
        </encoder>
    </appender>

    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <target>System.out</target>
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
          <level>DEBUG</level>
          <onMatch>ACCEPT</onMatch>
        </filter>
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
          <level>INFO</level>
          <onMatch>ACCEPT</onMatch>
        </filter>
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
          <level>TRACE</level>
          <onMatch>ACCEPT</onMatch>
        </filter>
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
          <level>WARN</level>
          <onMatch>DENY</onMatch>
        </filter>
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
          <level>ERROR</level>
          <onMatch>DENY</onMatch>
        </filter>
        <encoder>
            <pattern>%date %level [%thread] %logger %msg%n</pattern>
        </encoder>
    </appender>

    <root level="INFO">
        <appender-ref ref="STDOUT" />
        <appender-ref ref="STDERR" />
    </root>
</configuration>

What is the preferred syntax for defining enums in JavaScript?

You could also try to define a new function and therebefore a new namespace, and add variables to it, like this.

function Color () {};  
Color.RED = 1;
Color.YELLOW = 2;

As long anybody uses the namespace granted by the function Color, everything will go fine. If you know Java, this is kind of old enums : where we use a class or interface only to hold static attributes. If a function, in javascript, is a kind of class, this is pretty much the same approach.

I thing is a very simple way to define enums.

Hope it helps!

Greetings.

Victor.

Adjust table column width to content size

If you want the table to still be 100% then set one of the columns to have a width:100%; That will extend that column to fill the extra space and allow the other columns to keep their auto width :)

Is there a date format to display the day of the week in java?

This should display 'Tue':

new SimpleDateFormat("EEE").format(new Date());

This should display 'Tuesday':

new SimpleDateFormat("EEEE").format(new Date());

This should display 'T':

new SimpleDateFormat("EEEEE").format(new Date());

So your specific example would be:

new SimpleDateFormat("yyyy-MM-EEE").format(new Date());

Python one-line "for" expression

Even array2.extend(array1) will work.

How to detect if a browser is Chrome using jQuery?

When I test the answer @IE, I got always "true". The better way is this which works also @IE:

var isChrome = /Chrome/.test(navigator.userAgent) && /Google Inc/.test(navigator.vendor);

As described in this answer: https://stackoverflow.com/a/4565120/1201725

Adding a HTTP header to the Angular HttpClient doesn't send the header, why?

set http headers like below in your http request

return this.http.get(url, { headers: new HttpHeaders({'Authorization': 'Bearer ' + token})
 });

How to animate GIFs in HTML document?

try

_x000D_

<img src="https://cdn.glitch.com/0e4d1ff3-5897-47c5-9711-d026c01539b8%2Fbddfd6e4434f42662b009295c9bab86e.gif?v=1573157191712" alt="this slowpoke moves"  width="250" alt="404 image"/>

_x000D_

and switch the src with your source. If the alt pops up, try a different url. If it doesn't work, restart your computer or switch your browser.

SQL query to get the deadlocks in SQL SERVER 2008

In order to capture deadlock graphs without using a trace (you don't need profiler necessarily), you can enable trace flag 1222. This will write deadlock information to the error log. However, the error log is textual, so you won't get nice deadlock graph pictures - you'll have to read the text of the deadlocks to figure it out.

I would set this as a startup trace flag (in which case you'll need to restart the service). However, you can run it only for the current running instance of the service (which won't require a restart, but which won't resume upon the next restart) using the following global trace flag command:

DBCC TRACEON(1222, -1);

A quick search yielded this tutorial:

http://www.mssqltips.com/sqlservertip/2130/finding-sql-server-deadlocks-using-trace-flag-1222/

Also note that if your system experiences a lot of deadlocks, this can really hammer your error log, and can become quite a lot of noise, drowning out other, important errors.

Have you considered third party monitoring tools? SQL Sentry Performance Advisor, for example, has a much nicer deadlock graph, showing you object / index names as well as the order in which the locks were taken. As a bonus, these are captured for you automatically on monitored servers without having to configure trace flags, run your own traces, etc.:

Disclaimer: I work for SQL Sentry.

How to build & install GLFW 3 and use it in a Linux project

If anyone's getting lazy and maybe perhaps doesn't know how to configure shell for all those libraries and -ls, then I created a python script(you have to have python3, most linux users have it.) that allows you to easily compile scripts and run them without worrying much, it just has regular system calls, just arranged neatly, I created it for my self but maybe it'd be useful: Here it is

How to update a git clone --mirror?

See here: Git doesn't clone all branches on subsequent clones?

If you really want this by pulling branches instead of push --mirror, you can have a look here:

"fetch --all" in a git bare repository doesn't synchronize local branches to the remote ones

This answer provides detailed steps on how to achieve that relatively easily:

no default constructor exists for class

If you define a class without any constructor, the compiler will synthesize a constructor for you (and that will be a default constructor -- i.e., one that doesn't require any arguments). If, however, you do define a constructor, (even if it does take one or more arguments) the compiler will not synthesize a constructor for you -- at that point, you've taken responsibility for constructing objects of that class, so the compiler "steps back", so to speak, and leaves that job to you.

You have two choices. You need to either provide a default constructor, or you need to supply the correct parameter when you define an object. For example, you could change your constructor to look something like:

Blowfish(BlowfishAlgorithm algorithm = CBC);

...so the ctor could be invoked without (explicitly) specifying an algorithm (in which case it would use CBC as the algorithm).

The other alternative would be to explicitly specify the algorithm when you define a Blowfish object:

class GameCryptography { 
    Blowfish blowfish_;
public:
    GameCryptography() : blowfish_(ECB) {}
    // ...
};

In C++ 11 (or later) you have one more option available. You can define your constructor that takes an argument, but then tell the compiler to generate the constructor it would have if you didn't define one:

class GameCryptography { 
public:

    // define our ctor that takes an argument
    GameCryptography(BlofishAlgorithm); 

    // Tell the compiler to do what it would have if we didn't define a ctor:
    GameCryptography() = default;
};

As a final note, I think it's worth mentioning that ECB, CBC, CFB, etc., are modes of operation, not really encryption algorithms themselves. Calling them algorithms won't bother the compiler, but is unreasonably likely to cause a problem for others reading the code.

Uploading Files in ASP.net without using the FileUpload server control

use the HTML control with a runat server attribute

 <input id="FileInput" runat="server" type="file" />

Then in asp.net Codebehind

 FileInput.PostedFile.SaveAs("DestinationPath");

There are also some 3'rd party options that will show progress if you intrested

Finding sum of elements in Swift array

Swift 4 example

class Employee {
    var salary: Int =  0
    init (_ salary: Int){
        self.salary = salary
    }
}

let employees = [Employee(100),Employee(300),Employee(600)]
var sumSalary = employees.reduce(0, {$0 + $1.salary}) //1000

wordpress contactform7 textarea cols and rows change in smaller screens

Add it after Placeholder attribute.

[textarea* message id:message class:form-control 40x7 placeholder "Message"]

pointer to array c++

j[0]; dereferences a pointer to int, so its type is int.

(*j)[0] has no type. *j dereferences a pointer to an int, so it returns an int, and (*j)[0] attempts to dereference an int. It's like attempting int x = 8; x[0];.

PHP AES encrypt / decrypt

For information MCRYPT_MODE_ECB doesn't use the IV (initialization vector). ECB mode divide your message into blocks and each block is encrypted separately. I really don't recommended it.

CBC mode use the IV to make each message unique. CBC is recommended and should be used instead of ECB.

Example :

<?php
$password = "myPassword_!";
$messageClear = "Secret message";

// 32 byte binary blob
$aes256Key = hash("SHA256", $password, true);

// for good entropy (for MCRYPT_RAND)
srand((double) microtime() * 1000000);
// generate random iv
$iv = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_CBC), MCRYPT_RAND);


$crypted = fnEncrypt($messageClear, $aes256Key);

$newClear = fnDecrypt($crypted, $aes256Key);

echo
"IV:        <code>".$iv."</code><br/>".
"Encrypred: <code>".$crypted."</code><br/>".
"Decrypred: <code>".$newClear."</code><br/>";

function fnEncrypt($sValue, $sSecretKey) {
    global $iv;
    return rtrim(base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $sSecretKey, $sValue, MCRYPT_MODE_CBC, $iv)), "\0\3");
}

function fnDecrypt($sValue, $sSecretKey) {
    global $iv;
    return rtrim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $sSecretKey, base64_decode($sValue), MCRYPT_MODE_CBC, $iv), "\0\3");
}

You have to stock the IV to decode each message (IV are not secret). Each message is unique because each message has an unique IV.

More informations about mode of operation (wikipedia).

javascript find and remove object in array based on key value

var items = [
  {"id":"88","name":"Lets go testing"},
  {"id":"99","name":"Have fun boys and girls"},
  {"id":"108","name":"You are awesome!"}
];

If you are using jQuery, use jQuery.grep like this:

items = $.grep(items, function(item) { 
  return item.id !== '88';
});
// items => [{ id: "99" }, { id: "108" }]

Using ES5 Array.prototype.filter:

items = items.filter(function(item) { 
  return item.id !== '88'; 
});
// items => [{ id: "99" }, { id: "108" }]

Android studio Error "Unsupported Modules Detected: Compilation is not supported for following modules"

Delete .idea/modules.xml
Reload All Gradle Projects

You do not want to remove entire .idea directory, because it contains e.g. dictionaries and shelved changes.

MVC - Set selected value of SelectList

A bit late to the party here but here's how simple this is:

ViewBag.Countries = new SelectList(countries.GetCountries(), "id", "countryName", "82");

this uses my method getcountries to populate a model called countries, obviousley you would replace this with whatever your datasource is, a model etc, then sets the id as the value in the selectlist. then just add the last param, in this case "82" to select the default selected item.

[edit] Here's how to use this in Razor:

@Html.DropDownListFor(model => model.CountryId, (IEnumerable<SelectListItem>)ViewBag.Countries, new { @class = "form-control" })

Important: Also, 1 other thing to watch out for, Make sure the model field that you use to store the selected Id (in this case model.CountryId) from the dropdown list is nullable and is set to null on the first page load. This one gets me every time.

Hope this saves someone some time.

Javascript - Open a given URL in a new tab by clicking a button

You can forget about using JavaScript because the browser controls whether or not it opens in a new tab. Your best option is to do something like the following instead:

<form action="http://www.yoursite.com/dosomething" method="get" target="_blank">
    <input name="dynamicParam1" type="text"/>
    <input name="dynamicParam2" type="text" />
    <input type="submit" value="submit" />
</form>

This will always open in a new tab regardless of which browser a client uses due to the target="_blank" attribute.

If all you need is to redirect with no dynamic parameters you can use a link with the target="_blank" attribute as Tim Büthe suggests.

querying WHERE condition to character length?

SELECT *
   FROM   my_table
   WHERE  substr(my_field,1,5) = "abcde";

Writing unit tests in Python: How do I start?

The docs for unittest would be a good place to start.

Also, it is a bit late now, but in the future please consider writing unit tests before or during the project itself. That way you can use them to test as you go along, and (in theory) you can use them as regression tests, to verify that your code changes have not broken any existing code. This would give you the full benefit of writing test cases :)

ALTER TABLE DROP COLUMN failed because one or more objects access this column

I had the same problem and this was the script that worked for me with a table with a two part name separated by a period ".".

USE [DATABASENAME] GO ALTER TABLE [TableNamePart1].[TableNamePart2] DROP CONSTRAINT [DF__ TableNamePart1D__ColumnName__5AEE82B9] GO ALTER TABLE [TableNamePart1].[ TableNamePart1] DROP COLUMN [ColumnName] GO

Activity restart on rotation Android

add this code to your menufests.xml .

this is your activity.

<activity
....
..
android:configChanges="orientation|screenSize"/>

Win32Exception (0x80004005): The wait operation timed out

I had the same issue, and by Running "exec sp_updatestats" the issue solved and works now

How can I access "static" class variables within class methods in Python?

class Foo(object):
     bar = 1
     def bah(self):
         print Foo.bar

f = Foo() 
f.bah()

Passing multiple parameters with $.ajax url

why not just pass an data an object with your key/value pairs then you don't have to worry about encoding

$.ajax({
    type: "Post",
    url: "getdata.php",
    data:{
       timestamp: timestamp,
       uid: id,
       uname: name
    },
    async: true,
    cache: false,
    success: function(data) {


    };
}?);?

Bootstrap carousel width and height

I had the same problem.

My height changed to its original height while my slide was animating to the left, ( in a responsive website )

so I fixed it with CSS only :

.carousel .item.left img{
    width: 100% !important;
}

How does Trello access the user's clipboard?

With the help of raincoat's code on GitHub, I managed to get a running version accessing the clipboard with plain JavaScript.

function TrelloClipboard() {
    var me = this;

    var utils = {
        nodeName: function (node, name) {
            return !!(node.nodeName.toLowerCase() === name)
        }
    }
    var textareaId = 'simulate-trello-clipboard',
        containerId = textareaId + '-container',
        container, textarea

    var createTextarea = function () {
        container = document.querySelector('#' + containerId)
        if (!container) {
            container = document.createElement('div')
            container.id = containerId
            container.setAttribute('style', [, 'position: fixed;', 'left: 0px;', 'top: 0px;', 'width: 0px;', 'height: 0px;', 'z-index: 100;', 'opacity: 0;'].join(''))
            document.body.appendChild(container)
        }
        container.style.display = 'block'
        textarea = document.createElement('textarea')
        textarea.setAttribute('style', [, 'width: 1px;', 'height: 1px;', 'padding: 0px;'].join(''))
        textarea.id = textareaId
        container.innerHTML = ''
        container.appendChild(textarea)

        textarea.appendChild(document.createTextNode(me.value))
        textarea.focus()
        textarea.select()
    }

    var keyDownMonitor = function (e) {
        var code = e.keyCode || e.which;
        if (!(e.ctrlKey || e.metaKey)) {
            return
        }
        var target = e.target
        if (utils.nodeName(target, 'textarea') || utils.nodeName(target, 'input')) {
            return
        }
        if (window.getSelection && window.getSelection() && window.getSelection().toString()) {
            return
        }
        if (document.selection && document.selection.createRange().text) {
            return
        }
        setTimeout(createTextarea, 0)
    }

    var keyUpMonitor = function (e) {
        var code = e.keyCode || e.which;
        if (e.target.id !== textareaId || code !== 67) {
            return
        }
        container.style.display = 'none'
    }

    document.addEventListener('keydown', keyDownMonitor)
    document.addEventListener('keyup', keyUpMonitor)
}

TrelloClipboard.prototype.setValue = function (value) {
    this.value = value;
}

var clip = new TrelloClipboard();
clip.setValue("test");

See a working example: http://jsfiddle.net/AGEf7/

grep for special characters in Unix

The one that worked for me is:

grep -e '->'

The -e means that the next argument is the pattern, and won't be interpreted as an argument.

From: http://www.linuxquestions.org/questions/programming-9/how-to-grep-for-string-769460/

Java - Convert String to valid URI object

I had similar problems for one of my projects to create a URI object from a string. I couldn't find any clean solution either. Here's what I came up with :

public static URI encodeURL(String url) throws MalformedURLException, URISyntaxException  
{
    URI uriFormatted = null; 

    URL urlLink = new URL(url);
    uriFormatted = new URI("http", urlLink.getHost(), urlLink.getPath(), urlLink.getQuery(), urlLink.getRef());

    return uriFormatted;
}

You can use the following URI constructor instead to specify a port if needed:

URI uri = new URI(scheme, userInfo, host, port, path, query, fragment);

How to avoid 'undefined index' errors?

In my case, I get it worked by defining the default value if the submitted data is empty. Here is what I finally did (using PHP7.3.5):

if(empty($_POST['auto'])){ $_POST['auto'] = ""; }

How to convert List<string> to List<int>?

Here is a safe variant that filters out invalid ints:

List<int> ints = strings
    .Select(s => Int32.TryParse(s, out int n) ? n : (int?)null)
    .Where(n => n.HasValue)
    .Select(n => n.Value)
    .ToList();

It uses an out variable introduced with C#7.0.

This other variant returns a list of nullable ints where null entries are inserted for invalid ints (i.e. it preserves the original list count):

List<int?> nullableInts = strings
    .Select(s => Int32.TryParse(s, out int n) ? n : (int?)null)
    .ToList();

Build query string for System.Net.HttpClient get

Or simply using my Uri extension

Code

public static Uri AttachParameters(this Uri uri, NameValueCollection parameters)
{
    var stringBuilder = new StringBuilder();
    string str = "?";
    for (int index = 0; index < parameters.Count; ++index)
    {
        stringBuilder.Append(str + parameters.AllKeys[index] + "=" + parameters[index]);
        str = "&";
    }
    return new Uri(uri + stringBuilder.ToString());
}

Usage

Uri uri = new Uri("http://www.example.com/index.php").AttachParameters(new NameValueCollection
                                                                           {
                                                                               {"Bill", "Gates"},
                                                                               {"Steve", "Jobs"}
                                                                           });

Result

http://www.example.com/index.php?Bill=Gates&Steve=Jobs

Image vs Bitmap class

This is a clarification because I have seen things done in code which are honestly confusing - I think the following example might assist others.

As others have said before - Bitmap inherits from the Abstract Image class

Abstract effectively means you cannot create a New() instance of it.

    Image imgBad1 = new Image();        // Bad - won't compile
    Image imgBad2 = new Image(200,200); // Bad - won't compile

But you can do the following:

    Image imgGood;  // Not instantiated object!
    // Now you can do this
    imgGood = new Bitmap(200, 200);

You can now use imgGood as you would the same bitmap object if you had done the following:

    Bitmap bmpGood = new Bitmap(200,200);

The nice thing here is you can draw the imgGood object using a Graphics object

    Graphics gr = default(Graphics);
    gr = Graphics.FromImage(new Bitmap(1000, 1000));
    Rectangle rect = new Rectangle(50, 50, imgGood.Width, imgGood.Height); // where to draw
    gr.DrawImage(imgGood, rect);

Here imgGood can be any Image object - Bitmap, Metafile, or anything else that inherits from Image!

How should you diagnose the error SEHException - External component has thrown an exception

if you are having a problem as describe in this post:

asp.net mvc debugger throwing SEHException

then the solution is:

if you have any application from Trusteer (like rapport or anything ) just uninstall and reboot your system, it'll work fine ... found this solution here:

http://forums.asp.net/t/1704958.aspx/8/10?Re+SEHException+thrown+when+I+run+the+application

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

Be consistent! JOIN-ing a VARCHAR to NVARCHAR has a big performance hit.

Page redirect with successful Ajax request

I suppose you could attack this in two ways;

1) insert window.location = 'http://www.yourdomain.com into the success function.

2) Use a further ajax call an inject this into an element on your page, further info on which you can find in the jQuery docs at http://api.jquery.com/jQuery.get/

Show special characters in Unix while using 'less' Command

Now, sometimes you already have less open, and you can't use cat on it. For example, you did a | less, and you can't just reopen a file, as that's actually a stream.

If all you need is to identify end of line, one easy way is to search for the last character on the line: /.$. The search will highlight the last character, even if it is a blank, making it easy to identify it.

That will only help with the end of line case. If you need other special characters, you can use the cat -vet solution above with marks and pipe:

mark the top of the text you're interested in: ma
go to the bottom of the text you're interested in and mark it, as well: mb
go back to the mark a: 'a
pipe from a to b through cat -vet and view the result in another less command: |bcat -vet | less

This will open another less process, which shows the result of running cat -vet on the text that lies between marks a and b.

If you want the whole thing, instead, do g|$cat -vet | less, to go to the first line and filter all lines through cat.

The advantage of this method over less options is that it does not mess with the output you see on the screen.

One would think that eight years after this question was originally posted, less would have that feature... But I can't even see a feature request for it on https://github.com/gwsw/less/issues

Arrow operator (->) usage in C

a->b is just short for (*a).b in every way (same for functions: a->b() is short for (*a).b()).

asp.net mvc3 return raw html to view

Give a try to return bootstrap alert message, this worked for me

return Content("<div class='alert alert-success'><a class='close' data-dismiss='alert'>
&times;</a><strong style='width:12px'>Thanks!</strong> updated successfully</div>");

Note: Don't forget to add bootstrap css and js in your view page

hope helps someone.

Asking the user for input until they give a valid response

Functional approach or "look mum no loops!":

from itertools import chain, repeat

prompts = chain(["Enter a number: "], repeat("Not a number! Try again: "))
replies = map(input, prompts)
valid_response = next(filter(str.isdigit, replies))
print(valid_response)

Enter a number:  a
Not a number! Try again:  b
Not a number! Try again:  1
1

or if you want to have a "bad input" message separated from an input prompt as in other answers:

prompt_msg = "Enter a number: "
bad_input_msg = "Sorry, I didn't understand that."
prompts = chain([prompt_msg], repeat('\n'.join([bad_input_msg, prompt_msg])))
replies = map(input, prompts)
valid_response = next(filter(str.isdigit, replies))
print(valid_response)

Enter a number:  a
Sorry, I didn't understand that.
Enter a number:  b
Sorry, I didn't understand that.
Enter a number:  1
1

How does it work?

prompts = chain(["Enter a number: "], repeat("Not a number! Try again: "))

This combination of itertools.chain and itertools.repeat will create an iterator which will yield strings "Enter a number: " once, and "Not a number! Try again: " an infinite number of times:

for prompt in prompts:
    print(prompt)

Enter a number: 
Not a number! Try again: 
Not a number! Try again: 
Not a number! Try again: 
# ... and so on

replies = map(input, prompts) - here map will apply all the prompts strings from the previous step to the input function. E.g.:

for reply in replies:
    print(reply)

Enter a number:  a
a
Not a number! Try again:  1
1
Not a number! Try again:  it doesn't care now
it doesn't care now
# and so on...

We use filter and str.isdigit to filter out those strings that contain only digits:

only_digits = filter(str.isdigit, replies)
for reply in only_digits:
    print(reply)

Enter a number:  a
Not a number! Try again:  1
1
Not a number! Try again:  2
2
Not a number! Try again:  b
Not a number! Try again: # and so on...

And to get only the first digits-only string we use next.

Other validation rules:

String methods: Of course you can use other string methods like str.isalpha to get only alphabetic strings, or str.isupper to get only uppercase. See docs for the full list.

Membership testing:
There are several different ways to perform it. One of them is by using __contains__ method:

from itertools import chain, repeat

fruits = {'apple', 'orange', 'peach'}
prompts = chain(["Enter a fruit: "], repeat("I don't know this one! Try again: "))
replies = map(input, prompts)
valid_response = next(filter(fruits.__contains__, replies))
print(valid_response)

Enter a fruit:  1
I don't know this one! Try again:  foo
I don't know this one! Try again:  apple
apple

Numbers comparison:
There are useful comparison methods which we can use here. For example, for __lt__ (<):

from itertools import chain, repeat

prompts = chain(["Enter a positive number:"], repeat("I need a positive number! Try again:"))
replies = map(input, prompts)
numeric_strings = filter(str.isnumeric, replies)
numbers = map(float, numeric_strings)
is_positive = (0.).__lt__
valid_response = next(filter(is_positive, numbers))
print(valid_response)

Enter a positive number: a
I need a positive number! Try again: -5
I need a positive number! Try again: 0
I need a positive number! Try again: 5
5.0

Or, if you don't like using dunder methods (dunder = double-underscore), you can always define your own function, or use the ones from the operator module.

Path existance:
Here one can use pathlib library and its Path.exists method:

from itertools import chain, repeat
from pathlib import Path

prompts = chain(["Enter a path: "], repeat("This path doesn't exist! Try again: "))
replies = map(input, prompts)
paths = map(Path, replies)
valid_response = next(filter(Path.exists, paths))
print(valid_response)

Enter a path:  a b c
This path doesn't exist! Try again:  1
This path doesn't exist! Try again:  existing_file.txt
existing_file.txt

Limiting number of tries:

If you don't want to torture a user by asking him something an infinite number of times, you can specify a limit in a call of itertools.repeat. This can be combined with providing a default value to the next function:

from itertools import chain, repeat

prompts = chain(["Enter a number:"], repeat("Not a number! Try again:", 2))
replies = map(input, prompts)
valid_response = next(filter(str.isdigit, replies), None)
print("You've failed miserably!" if valid_response is None else 'Well done!')

Enter a number: a
Not a number! Try again: b
Not a number! Try again: c
You've failed miserably!

Preprocessing input data:

Sometimes we don't want to reject an input if the user accidentally supplied it IN CAPS or with a space in the beginning or an end of the string. To take these simple mistakes into account we can preprocess the input data by applying str.lower and str.strip methods. For example, for the case of membership testing the code will look like this:

from itertools import chain, repeat

fruits = {'apple', 'orange', 'peach'}
prompts = chain(["Enter a fruit: "], repeat("I don't know this one! Try again: "))
replies = map(input, prompts)
lowercased_replies = map(str.lower, replies)
stripped_replies = map(str.strip, lowercased_replies)
valid_response = next(filter(fruits.__contains__, stripped_replies))
print(valid_response)

Enter a fruit:  duck
I don't know this one! Try again:     Orange
orange

In the case when you have many functions to use for preprocessing, it might be easier to use a function performing a function composition. For example, using the one from here:

from itertools import chain, repeat

from lz.functional import compose

fruits = {'apple', 'orange', 'peach'}
prompts = chain(["Enter a fruit: "], repeat("I don't know this one! Try again: "))
replies = map(input, prompts)
process = compose(str.strip, str.lower)  # you can add more functions here
processed_replies = map(process, replies)
valid_response = next(filter(fruits.__contains__, processed_replies))
print(valid_response)

Enter a fruit:  potato
I don't know this one! Try again:   PEACH
peach

Combining validation rules:

For a simple case, for example, when the program asks for age between 1 and 120, one can just add another filter:

from itertools import chain, repeat

prompt_msg = "Enter your age (1-120): "
bad_input_msg = "Wrong input."
prompts = chain([prompt_msg], repeat('\n'.join([bad_input_msg, prompt_msg])))
replies = map(input, prompts)
numeric_replies = filter(str.isdigit, replies)
ages = map(int, numeric_replies)
positive_ages = filter((0).__lt__, ages)
not_too_big_ages = filter((120).__ge__, positive_ages)
valid_response = next(not_too_big_ages)
print(valid_response)

But in the case when there are many rules, it's better to implement a function performing a logical conjunction. In the following example I will use a ready one from here:

from functools import partial
from itertools import chain, repeat

from lz.logical import conjoin


def is_one_letter(string: str) -> bool:
    return len(string) == 1


rules = [str.isalpha, str.isupper, is_one_letter, 'C'.__le__, 'P'.__ge__]

prompt_msg = "Enter a letter (C-P): "
bad_input_msg = "Wrong input."
prompts = chain([prompt_msg], repeat('\n'.join([bad_input_msg, prompt_msg])))
replies = map(input, prompts)
valid_response = next(filter(conjoin(*rules), replies))
print(valid_response)

Enter a letter (C-P):  5
Wrong input.
Enter a letter (C-P):  f
Wrong input.
Enter a letter (C-P):  CDE
Wrong input.
Enter a letter (C-P):  Q
Wrong input.
Enter a letter (C-P):  N
N

Unfortunately, if someone needs a custom message for each failed case, then, I'm afraid, there is no pretty functional way. Or, at least, I couldn't find one.

How to know Laravel version and where is it defined?

Run this command in your project folder location in cmd

php artisan --version

What does Python's eval() do?

Datatables - Setting column width

You can define sScrollX : "100%" to force dataTables to keep the column widths :

..
 sScrollX: "100%", //<-- here
 aoColumns : [
      { "sWidth": "100px"},
      { "sWidth": "100px"},
      { "sWidth": "100px"},
      { "sWidth": "100px"},
      { "sWidth": "100px"},
      { "sWidth": "100px"},
      { "sWidth": "100px"},
      { "sWidth": "100px"},
    ],
...

you can play with this fiddle -> http://jsfiddle.net/vuAEx/

Find all stored procedures that reference a specific column in some table

SELECT *
FROM   sys.all_sql_modules
WHERE  definition LIKE '%CreatedDate%'

SELECT with a Replace()

You can reference is that way if you wrap the query, like this:

SELECT P
FROM (SELECT Replace(Postcode, ' ', '') AS P
      FROM Contacts) innertable
WHERE P LIKE 'NW101%'

Be sure to give the wrapped select an alias, even unused (SQL Server doesn't allow it without one IIRC)

Disable click outside of angular material dialog area to close the dialog (With Angular Version 4.0+)

Add

[config]="{backdrop: 'static'}"

to the model code.

How to set a default value with Html.TextBoxFor?

Using @Value is a hack, because it outputs two attributes, e.g.:

<input type="..." Value="foo" value=""/>

You should do this instead:

@Html.TextBox(Html.NameFor(p => p.FirstName).ToString(), "foo")

Get Row Index on Asp.net Rowcommand event

this is answer for your question.

GridViewRow gvr = (GridViewRow)((ImageButton)e.CommandSource).NamingContainer;

int RowIndex = gvr.RowIndex;

Multidimensional arrays in Swift

var array: Int[][] = [[1,2,3],[4,5,6],[7,8,9]]

for first in array {
    for second in first {
        println("value \(second)")
    }
}

To achieve what you're looking for you need to initialize the array to the correct template and then loop to add the row and column arrays:

var NumColumns = 27
var NumRows = 52
var array = Array<Array<Int>>()
var value = 1

for column in 0..NumColumns {
    var columnArray = Array<Int>()
    for row in 0..NumRows {
        columnArray.append(value++)
    }
    array.append(columnArray)
}

println("array \(array)")

C# List of objects, how do I get the sum of a property

And if you need to do it on items that match a specific condition...

double total = myList.Where(item => item.Name == "Eggs").Sum(item => item.Amount);

symbol(s) not found for architecture i386

Another situation that can cause this problem is if your code calls into C++, or is called by C++ code. I had a problem with my own .c file's utility function showing up as "symbol not found" when called from Obj-C. The fix was to change the file type: in Xcode 4, use the extended info pane to set the file type to "Objective-C++ Source"; in Xcode 3, use "Get Info" to change file type to "source.cpp.objcpp".

Using Ansible set_fact to create a dictionary from register results

I think I got there in the end.

The task is like this:

- name: Populate genders
  set_fact:
    genders: "{{ genders|default({}) | combine( {item.item.name: item.stdout} ) }}"
  with_items: "{{ people.results }}"

It loops through each of the dicts (item) in the people.results array, each time creating a new dict like {Bob: "male"}, and combine()s that new dict in the genders array, which ends up like:

{
    "Bob": "male",
    "Thelma": "female"
}

It assumes the keys (the name in this case) will be unique.

I then realised I actually wanted a list of dictionaries, as it seems much easier to loop through using with_items:

- name: Populate genders
  set_fact:
    genders: "{{ genders|default([]) + [ {'name': item.item.name, 'gender': item.stdout} ] }}"
  with_items: "{{ people.results }}"

This keeps combining the existing list with a list containing a single dict. We end up with a genders array like this:

[
    {'name': 'Bob', 'gender': 'male'},
    {'name': 'Thelma', 'gender': 'female'}
]

jQuery get specific option tag text

I needed this answer as I was dealing with a dynamically cast object, and the other methods here did not seem to work:

element.options[element.selectedIndex].text

This of course uses the DOM object instead of parsing its HTML with nodeValue, childNodes, etc.

How can I get the current directory name in Javascript?

complete URL

If you want the complete URL e.g. http://website/basedirectory/workingdirectory/ use:

var location = window.location.href;
var directoryPath = location.substring(0, location.lastIndexOf("/")+1);

local path

If you want the local path without domain e.g. /basedirectory/workingdirectory/ use:

var location = window.location.pathname;
var directoryPath = location.substring(0, location.lastIndexOf("/")+1);

In case you don't need the slash at the end, remove the +1 after location.lastIndexOf("/")+1.

directory name

If you only want the current directory name, where the script is running in, e.g. workingdirectory use:

var location = window.location.pathname;
var path = location.substring(0, location.lastIndexOf("/"));
var directoryName = path.substring(path.lastIndexOf("/")+1);

What's the best way to break from nested loops in JavaScript?

I thought I'd show a functional-programming approach. You can break out of nested Array.prototype.some() and/or Array.prototype.every() functions, as in my solutions. An added benefit of this approach is that Object.keys() enumerates only an object's own enumerable properties, whereas "a for-in loop enumerates properties in the prototype chain as well".

Close to the OP's solution:

    Args.forEach(function (arg) {
        // This guard is not necessary,
        // since writing an empty string to document would not change it.
        if (!getAnchorTag(arg))
            return;

        document.write(getAnchorTag(arg));
    });

    function getAnchorTag (name) {
        var res = '';

        Object.keys(Navigation.Headings).some(function (Heading) {
            return Object.keys(Navigation.Headings[Heading]).some(function (Item) {
                if (name == Navigation.Headings[Heading][Item].Name) {
                    res = ("<a href=\""
                                 + Navigation.Headings[Heading][Item].URL + "\">"
                                 + Navigation.Headings[Heading][Item].Name + "</a> : ");
                    return true;
                }
            });
        });

        return res;
    }

Solution that reduces iterating over the Headings/Items:

    var remainingArgs = Args.slice(0);

    Object.keys(Navigation.Headings).some(function (Heading) {
        return Object.keys(Navigation.Headings[Heading]).some(function (Item) {
            var i = remainingArgs.indexOf(Navigation.Headings[Heading][Item].Name);

            if (i === -1)
                return;

            document.write("<a href=\""
                                         + Navigation.Headings[Heading][Item].URL + "\">"
                                         + Navigation.Headings[Heading][Item].Name + "</a> : ");
            remainingArgs.splice(i, 1);

            if (remainingArgs.length === 0)
                return true;
            }
        });
    });

Show only two digit after decimal

How about String.format("%.2f", i2)?

How do I exclude Weekend days in a SQL Server query?

Calculate Leave working days in a table column as a default value--updated

If you are using SQL here is the query which can help you: http://gallery.technet.microsoft.com/Calculate...

In Perl, how do I create a hash whose keys come from a given array?

@hash{@keys} = undef;

The syntax here where you are referring to the hash with an @ is a hash slice. We're basically saying $hash{$keys[0]} AND $hash{$keys[1]} AND $hash{$keys[2]} ... is a list on the left hand side of the =, an lvalue, and we're assigning to that list, which actually goes into the hash and sets the values for all the named keys. In this case, I only specified one value, so that value goes into $hash{$keys[0]}, and the other hash entries all auto-vivify (come to life) with undefined values. [My original suggestion here was set the expression = 1, which would've set that one key to 1 and the others to undef. I changed it for consistency, but as we'll see below, the exact values do not matter.]

When you realize that the lvalue, the expression on the left hand side of the =, is a list built out of the hash, then it'll start to make some sense why we're using that @. [Except I think this will change in Perl 6.]

The idea here is that you are using the hash as a set. What matters is not the value I am assigning; it's just the existence of the keys. So what you want to do is not something like:

if ($hash{$key} == 1) # then key is in the hash

instead:

if (exists $hash{$key}) # then key is in the set

It's actually more efficient to just run an exists check than to bother with the value in the hash, although to me the important thing here is just the concept that you are representing a set just with the keys of the hash. Also, somebody pointed out that by using undef as the value here, we will consume less storage space than we would assigning a value. (And also generate less confusion, as the value does not matter, and my solution would assign a value only to the first element in the hash and leave the others undef, and some other solutions are turning cartwheels to build an array of values to go into the hash; completely wasted effort).

How to display special characters in PHP

One of the best ways to do this is, change Collation in my SQL database.

step 1: Go to the Mysql database

step 2: Select the Text-based Row you want to get displayed (Eg., post or comments)

step 3: edit the row and select collation as below.

utf8mb4_unicode_ci

Make sure to change the collation of text rows whichever you want to display the special characters.

Sometimes htmlspecialchars_decode() or any other entity() doesn't convert your special chars to normal. So, the above method will definitely help.

What is the command to exit a Console application in C#?

Console applications will exit when the main function has finished running. A "return" will achieve this.

    static void Main(string[] args)
    {
        while (true)
        {
            Console.WriteLine("I'm running!");
            return; //This will exit the console application's running thread
        }
    }

If you're returning an error code you can do it this way, which is accessible from functions outside of the initial thread:

    System.Environment.Exit(-1);

Unresponsive KeyListener for JFrame

You must add your keyListener to every component that you need. Only the component with the focus will send these events. For instance, if you have only one TextBox in your JFrame, that TextBox has the focus. So you must add a KeyListener to this component as well.

The process is the same:

myComponent.addKeyListener(new KeyListener ...);

Note: Some components aren't focusable like JLabel.

For setting them to focusable you need to:

myComponent.setFocusable(true);

remove all special characters in java

Your problem is that the indices returned by match.start() correspond to the position of the character as it appeared in the original string when you matched it; however, as you rewrite the string c every time, these indices become incorrect.

The best approach to solve this is to use replaceAll, for example:

        System.out.println(c.replaceAll("[^a-zA-Z0-9]", ""));

Prevent PDF file from downloading and printing

I wish I had an answer but I only have Part of one. And I cannot take credit for it but the way to get it is below.
This is a more serious issue than it is being given credit for from the sound of the replies. Everyone is automatically assuming that the content that needs protection is for public consumption. This is not always the case. Sometimes there are legal or contractual reasons that require the site owner to take all possible measures to prevent downloading the file. The most obvious one I can think of has already brought up. The “Action Option Bar” presented by the browser to on almost any file you can left click.
Adobe DRM does nothing about that and worse, Adobe Acrobat cannot even have its own abilities to “Save” blocked as part of the “DRM” protection. This option comes up even in Reader no matter what other security selections you have chosen.

In our case, Adobe Acrobat was purchased solely to provide some degree of protection for their own format. It is hard to believe that Adobe will let you prevent printing, prevent editing, prevent even opening without a password or you can really go all out and use a certificate for your encryption. Yet they have no options to prevent saving at any point, anywhere. Instead offering the consolation of telling you “Don’t worry: The copy they download without your permission will also have the same DRM on it as well”. Unfortunately that was not the sole purpose of the purchase and half a solution is no “solution” at all. There are probably 100 programs that are actually sold just to remove the DRM from Adobe documents and even if not, the point was that the client specified that no downloads be allowed even by users who had access to the private site. Therefore the need to prevent the download to start with is not so hard to understand. While conversion to FLASH may give you the download protection, you lose all the rest. Unless I can find a way to prevent opening, saving etc for a Flash File. Next, is it possible to password protect a Flash file from opening when clicked on?

The “partial fix” that I was finally able to get to work as needed still only disables all the “right click” functions but it does include a nice “Warning Box” where I can explain that the User has already agreed NOT to download, print, save and so on just to have access to the page. I am not sure if I could post the code here or whether it is acceptable to paste links either but a Google search for "Maximus right click" will take you to it. And it was one of several examples, it just happened to be the one I could implement the easiest and worked better than the others. Credit where credit is due.

Another option I was given by someone was a product called “Flipping Book”. And the user above suggestions for “Atalasoft” ( I had already found that and have sent a request for more information). Hopefully it will be “The Solution” and I can implement it in time to help. It seems to me that this is a place where there is an obvious need for a one-step packaged solution and usually "The Laws of Nature" take care of such an Imbalance in short order. Yet my research has taken me through many years of posters all asking for the same thing. Looks like someone would be able to make a nice living off a “simple” way to add a little more "protection" to “PDFs” (or other documents, images etc) for the people who obviously are in need of it. If I find it, and it works, I'm buying it. :>)

I wish I had skills as a programmer because I have some pretty good ideas of ways to implement such a product, unfortunately, I do not know how to put these ideas into practical use.

Using Spring 3 autowire in a standalone Java application

For Spring 4, using Spring Boot we can have the following example without using the anti-pattern of getting the Bean from the ApplicationContext directly:

package com.yourproject;

@SpringBootApplication
public class TestBed implements CommandLineRunner {

    private MyService myService;

    @Autowired
    public TestBed(MyService myService){
        this.myService = myService;
    }

    public static void main(String... args) {
        SpringApplication.run(TestBed.class, args);
    }

    @Override
    public void run(String... strings) throws Exception {
        System.out.println("myService: " + MyService );
    }

}

@Service 
public class MyService{
    public String getSomething() {
        return "something";
    }
}

Make sure that all your injected services are under com.yourproject or its subpackages.

Is there a function to split a string in PL/SQL?

There is a simple way folks. Use REPLACE function. Here is an example of comma separated string ready to be passed to IN clause.

In PL/SQL:

StatusString :=   REPLACE('Active,Completed', ',', ''',''');

In SQL Plus:

Select  REPLACE('Active,Completed', ',', ''',''') from dual;

How can I get my Android device country code without using GPS?

Here is a complete example. It tries to get the country code from TelephonyManager (from SIM or CDMA devices), and if not available, tries to get it from the local configuration.

private static String getDeviceCountryCode(Context context) {
    String countryCode;

    // Try to get country code from TelephonyManager service
    TelephonyManager tm = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
    if(tm != null) {
        // Query first getSimCountryIso()
        countryCode = tm.getSimCountryIso();
        if (countryCode != null && countryCode.length() == 2)
            return countryCode.toLowerCase();

        if (tm.getPhoneType() == TelephonyManager.PHONE_TYPE_CDMA) {
            // Special case for CDMA Devices
            countryCode = getCDMACountryIso();
        }
        else {
            // For 3G devices (with SIM) query getNetworkCountryIso()
            countryCode = tm.getNetworkCountryIso();
        }

        if (countryCode != null && countryCode.length() == 2)
            return countryCode.toLowerCase();
    }

    // If network country not available (tablets maybe), get country code from Locale class
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
        countryCode = context.getResources().getConfiguration().getLocales().get(0).getCountry();
    }
    else {
        countryCode = context.getResources().getConfiguration().locale.getCountry();
    }

    if (countryCode != null && countryCode.length() == 2)
        return  countryCode.toLowerCase();

    // General fallback to "us"
    return "us";
}

@SuppressLint("PrivateApi")
private static String getCDMACountryIso() {
    try {
        // Try to get country code from SystemProperties private class
        Class<?> systemProperties = Class.forName("android.os.SystemProperties");
        Method get = systemProperties.getMethod("get", String.class);

        // Get homeOperator that contain MCC + MNC
        String homeOperator = ((String) get.invoke(systemProperties,
                "ro.cdma.home.operator.numeric"));

        // First three characters (MCC) from homeOperator represents the country code
        int mcc = Integer.parseInt(homeOperator.substring(0, 3));

        // Mapping just countries that actually use CDMA networks
        switch (mcc) {
            case 330: return "PR";
            case 310: return "US";
            case 311: return "US";
            case 312: return "US";
            case 316: return "US";
            case 283: return "AM";
            case 460: return "CN";
            case 455: return "MO";
            case 414: return "MM";
            case 619: return "SL";
            case 450: return "KR";
            case 634: return "SD";
            case 434: return "UZ";
            case 232: return "AT";
            case 204: return "NL";
            case 262: return "DE";
            case 247: return "LV";
            case 255: return "UA";
        }
    }
    catch (ClassNotFoundException ignored) {
    }
    catch (NoSuchMethodException ignored) {
    }
    catch (IllegalAccessException ignored) {
    }
    catch (InvocationTargetException ignored) {
    }
    catch (NullPointerException ignored) {
    }

    return null;
}

Also another idea is to try an API request like in this answer.

References are here and here.

How to center the content inside a linear layout?

android:gravity handles the alignment of its children,

android:layout_gravity handles the alignment of itself.

So use one of these.

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#000"
    android:baselineAligned="false"
    android:gravity="center"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".Main" >

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:gravity="center" >

        <ImageView
            android:id="@+id/imageButton_speak"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_speak" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:gravity="center" >

        <ImageView
            android:id="@+id/imageButton_readtext"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_readtext" />
    </LinearLayout>

    ...
</LinearLayout>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#000"
    android:baselineAligned="false"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".Main" >

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1" >

        <ImageView
            android:id="@+id/imageButton_speak"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_speak" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1" >

        <ImageView
            android:id="@+id/imageButton_readtext"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_readtext" />
    </LinearLayout>

    ...
</LinearLayout>

Why does .json() return a promise?

In addition to the above answers here is how you might handle a 500 series response from your api where you receive an error message encoded in json:

function callApi(url) {
  return fetch(url)
    .then(response => {
      if (response.ok) {
        return response.json().then(response => ({ response }));
      }

      return response.json().then(error => ({ error }));
    })
  ;
}

let url = 'http://jsonplaceholder.typicode.com/posts/6';

const { response, error } = callApi(url);
if (response) {
  // handle json decoded response
} else {
  // handle json decoded 500 series response
}

How to view user privileges using windows cmd?

You can use the following commands:

whoami /priv
whoami /all

For more information, check whoami @ technet.

How can I run Tensorboard on a remote server?

Another approach is to use a reverse proxy, which allows you to view Tensorboard from any internet connected device without SSHing. This approach can make it far easier / tractable to view Tensorboard on mobile devices, for example.

Steps:

1) Download reverse proxy Ngrok on your remote machine hosting Tensorboard. See https://ngrok.com/download for instructions (~5 minute setup).

2) Run ngrok http 6006 (assuming you're hosting Tensorboard on port 6006)

3) Save the URL that ngrok outputs:

4) Enter that into any browser to view TensorBoard:

Special thanks to Sam Kirkiles

MySQL select rows where left join is null

Try:

SELECT A.id FROM
(
  SELECT table1.id FROM table1 
  LEFT JOIN table2 ON table1.id = table2.user_one
  WHERE table2.user_one IS NULL
) A
JOIN (
  SELECT table1.id FROM table1 
  LEFT JOIN table2 ON table1.id = table2.user_two
  WHERE table2.user_two IS NULL
) B
ON A.id = B.id

See Demo

Or you could use two LEFT JOINS with aliases like:

SELECT table1.id FROM table1 
 LEFT JOIN table2 A ON table1.id = A.user_one
 LEFT JOIN table2 B ON table1.id = B.user_two
 WHERE A.user_one IS NULL
 AND B.user_two IS NULL

See 2nd Demo

How can I read Chrome Cache files?

I had some luck with this open-source Python project, seemingly inactive: https://github.com/JRBANCEL/Chromagnon

I ran:

python2 Chromagnon/chromagnonCache.py path/to/Chrome/Cache -o browsable_cache/

And I got a locally-browsable extract of all my open tabs cache.

Running two projects at once in Visual Studio

Go to Solution properties ? Common Properties ? Startup Project and select Multiple startup projects.

compare two files in UNIX

I got the solution by using comm

comm -23 file1 file2

will give you the desired output.

The files need to be sorted first anyway.

How do I create a user account for basic authentication?

Right click on Computer and choose "Manage" (or go to Control Panel > Administrative Tools > Computer Management) and under "Local Users and Groups" you can add a new user. Then, give that user permission to read the directory where the site is hosted.

Note: After creating the user, be sure to edit the user and remove all roles.

Syncing Android Studio project with Gradle files

I am using Android Studio 4 developing a Fluter/Dart application. There does not seem to be a Sync project with gradle button or file menu item, there is no clean or rebuild either.

I fixed the problem by removing the .idea folder. The suggestion included removing .gradle as well, but it did not exist.

li:before{ content: "¦"; } How to Encode this Special Character as a Bullit in an Email Stationery?

You ca try this:

ul { list-style: none;}

li { position: relative;}

li:before {
    position: absolute;  
    top: 8px;  
    margin: 8px 0 0 -12px;    
    vertical-align: middle;
    display: inline-block;
    width: 4px;
    height: 4px;
    background: #ccc;
    content: "";
}

It worked for me, thanks to this post.

What is web.xml file and what are all things can I do with it?

What is web.xml file and what all things can I do with it ?

The /WEB-INF/web.xml file is the Web Application Deployment Descriptor of your application. This file is an XML document that defines everything about your application that a server needs to know (except the context path, which is assigned by the Application Deployer and Administrator when the application is deployed): servlets and other components like filters or listeners, initialization parameters, container-managed security constraints, resources, welcome pages, etc.

Note that reference you mentioned is pretty old (Java EE 1.4), there have been few changes in Java EE 5 and even more in Java EE 6 (which makes the web.xml "optional" and introduces Web Fragments).

Is there any configuration parameter which should be avoided like plague?

No.

Any parameters related to performance or memory usage?

No, such things are not configured at the application level but at the container level.

Security related risk due to common mis-configuration ?

Well, if you want to use container-managed security constraints and fail at configuring them properly, resources won't obviously be properly protected. Apart from that, the biggest security risks come from the code you'll deploy IMO.

Add views in UIStackView programmatically

Try below code,

UIView *view1 = [[UIView alloc]init];
view1.backgroundColor = [UIColor blackColor];
[view1 setFrame:CGRectMake(0, 0, 50, 50)];

UIView *view2 =  [[UIView alloc]init];
view2.backgroundColor = [UIColor greenColor];
[view2 setFrame:CGRectMake(0, 100, 100, 100)];

NSArray *subView = [NSArray arrayWithObjects:view1,view2, nil];

[self.stack1 initWithArrangedSubviews:subView];

Hope it works. Please let me know if you need anymore clarification.

$apply already in progress error

I call $scope.$apply like this to ignored call multiple in one times.

      var callApplyTimeout = null;
      function callApply(callback) {
          if (!callback) callback = function () { };
          if (callApplyTimeout) $timeout.cancel(callApplyTimeout);

          callApplyTimeout = $timeout(function () {
              callback();
              $scope.$apply();
              var d = new Date();
              var m = d.getMilliseconds();
              console.log('$scope.$apply(); call ' + d.toString() + ' ' + m);
          }, 300);
      }

simply call

callApply();

How do I compile C++ with Clang?

I do not know why there is no answer directly addressing the problem. When you want to compile C++ program, it is best to use clang++. For example, the following works for me:

clang++ -Wall -std=c++11 test.cc -o test

If compiled correctly, it will produce the executable file test, and you can run the file by using ./test.

Or you can just use clang++ test.cc to compile the program. It will produce a default executable file named a.out. Use ./a.out to run the file.

The whole process is a lot like g++ if you are familiar with g++. See this post to check which warnings are included with -Wall option. This page shows a list of diagnostic flags supported by Clang.

A note on using clang -x c++: Kim Gräsman says that you can also use clang -x c++ to compile cpp programs, but that may not be true. For example, I am having a simple program below:

#include <iostream>
#include <vector>

int main() {
    /* std::vector<int> v = {1, 2, 3, 4, 5}; */
    std::vector<int> v(10, 5);
    int sum = 0;
    for (int i = 0; i < v.size(); i++){
        sum += v[i]*2;
    }
    std::cout << "sum is " << sum << std::endl;
    return 0;
}

clang++ test.cc -o test will compile successfully, but clang -x c++ will not, showing a lot undefined references errors. So I guess they are not exactly equivalent. It is best to use clang++ instead of clang -x c++ when compiling c++ programs to avoid extra troubles.

clang version: 11.0.0
Platform: Ubuntu 16.04

Codeigniter $this->db->get(), how do I return values for a specific row?

Incase you are dynamically getting your data e.g When you need data based on the user logged in by their id use consider the following code example for a No Active Record:

 $this->db->query('SELECT * FROM my_users_table WHERE id = ?', $this->session->userdata('id'));

 return $query->row_array();

This will return a specific row based on your the set session data of user.

TSQL How do you output PRINT in a user defined function?

I got around this by temporarily rewriting my function to something like this:

IF OBJECT_ID ('[dbo].[fx_dosomething]', 'TF') IS NOT NULL
  drop function [dbo].[fx_dosomething];
GO

create FUNCTION dbo.fx_dosomething ( @x numeric )
returns @t table (debug varchar(100), x2 numeric)
as
begin
 declare @debug varchar(100)
 set @debug = 'printme';

 declare @x2 numeric
 set @x2 = 0.123456;

 insert into @t values (@debug, @x2)
 return 
end
go

select * from fx_dosomething(0.1)

How can I solve the error LNK2019: unresolved external symbol - function?

One option would be to include function.cpp in your UnitTest1 project, but that may not be the most ideal solution structure. The short answer to your problem is that when building your UnitTest1 project, the compiler and linker have no idea that function.cpp exists, and also have nothing to link that contains a definition of multiple. A way to fix this is making use of linking libraries.

Since your unit tests are in a different project, I'm assuming your intention is to make that project a standalone unit-testing program. With the functions you are testing located in another project, it's possible to build that project to either a dynamically or statically linked library. Static libraries are linked to other programs at build time, and have the extension .lib, and dynamic libraries are linked at runtime, and have the extension .dll. For my answer I'll prefer static libraries.

You can turn your first program into a static library by changing it in the projects properties. There should be an option under the General tab where the project is set to build to an executable (.exe). You can change this to .lib. The .lib file will build to the same place as the .exe.

In your UnitTest1 project, you can go to its properties, and under the Linker tab in the category Additional Library Directories, add the path to which MyProjectTest builds. Then, for Additional Dependencies under the Linker - Input tab, add the name of your static library, most likely MyProjectTest.lib.

That should allow your project to build. Note that by doing this, MyProjectTest will not be a standalone executable program unless you change its build properties as needed, which would be less than ideal.

jquery .html() vs .append()

Other than the given answers, in the case that you have something like this:

<div id="test">
    <input type="file" name="file0" onchange="changed()">
</div>
<script type="text/javascript">
    var isAllowed = true;
    function changed()
    {
        if (isAllowed)
        {
            var tmpHTML = $('#test').html();
            tmpHTML += "<input type=\"file\" name=\"file1\" onchange=\"changed()\">";
            $('#test').html(tmpHTML);
            isAllowed = false;
        }
    }
</script>

meaning that you want to automatically add one more file upload if any files were uploaded, the mentioned code will not work, because after the file is uploaded, the first file-upload element will be recreated and therefore the uploaded file will be wiped from it. You should use .append() instead:

    function changed()
    {
        if (isAllowed)
        {
            var tmpHTML = "<input type=\"file\" name=\"file1\" onchange=\"changed()\">";
            $('#test').append(tmpHTML);
            isAllowed = false;
        }
    }

npm behind a proxy fails with status 403

If anyone else ends up breaking their proxy config settings go to your .npmrc, to type in the settings. This file is located at your node root folder level.

Here's whats my corrected file looks like:

#proxy = http://proxy.company.com:8080
https-proxy = https://proxy.company.com:8080 
registry = http://registry.npmjs.org/

Passing an array as parameter in JavaScript

It is possible to pass arrays to functions, and there are no special requirements for dealing with them. Are you sure that the array you are passing to to your function actually has an element at [0]?

Get commit list between tags in git

To compare between latest commit of current branch and a tag:

git log --pretty=oneline HEAD...tag

How to escape a while loop in C#

Use break; to escape the first loop:

if (s.Contains("mp4:production/CATCHUP/"))
{
   RemoveEXELog();
   Process p = new Process();
   p.StartInfo.WorkingDirectory = "dump";
   p.StartInfo.FileName = "test.exe"; 
   p.StartInfo.Arguments = s; 
   p.Start();
   break;
}

If you want to also escape the second loop, you might need to use a flag and check in the out loop's guard:

        boolean breakFlag = false;
        while (!breakFlag)
        {
            Thread.Sleep(5000);
            if (!System.IO.File.Exists("Command.bat")) continue;
            using (System.IO.StreamReader sr = System.IO.File.OpenText("Command.bat"))
            {
                string s = "";
                while ((s = sr.ReadLine()) != null)
                {
                    if (s.Contains("mp4:production/CATCHUP/"))
                    {

                        RemoveEXELog();

                        Process p = new Process();
                        p.StartInfo.WorkingDirectory = "dump";
                        p.StartInfo.FileName = "test.exe"; 
                        p.StartInfo.Arguments = s; 
                        p.Start();

                        breakFlag = true;
                        break;
                    }
                }
            }

Or, if you want to just exit the function completely from within the nested loop, put in a return; instead of a break;.

But these aren't really considered best practices. You should find some way to add the necessary Boolean logic into your while guards.

How do I convert a number to a numeric, comma-separated formatted string?

The reason you aren't finding easy examples for how to do this in T-SQL is that it is generally considered bad practice to implement formatting logic in SQL code. RDBMS's simply are not designed for presentation. While it is possible to do some limited formatting, it is almost always better to let the application or user interface handle formatting of this type.

But if you must (and sometimes we must!) use T-SQL, cast your int to money and convert it to varchar, like this:

select convert(varchar,cast(1234567 as money),1)

If you don't want the trailing decimals, do this:

select replace(convert(varchar,cast(1234567 as money),1), '.00','')

Good luck!

Pandas group-by and sum

A variation on the .agg() function; provides the ability to (1) persist type DataFrame, (2) apply averages, counts, summations, etc. and (3) enables groupby on multiple columns while maintaining legibility.

df.groupby(['att1', 'att2']).agg({'att1': "count", 'att3': "sum",'att4': 'mean'})

using your values...

df.groupby(['Name', 'Fruit']).agg({'Number': "sum"})

How to pass values between Fragments

Communicating between fragments is fairly complicated (I find the listeners concept a little challenging to implement).

It is common to use a 'Event Bus" to abstract these communications. This is a 3rd party library that takes care of this communication for you.

'Otto' is one that is used often to do this, and might be worth looking into: http://square.github.io/otto/

What's the difference between Invoke() and BeginInvoke()

The difference between Control.Invoke() and Control.BeginInvoke() is,

BeginInvoke() will schedule the asynchronous action on the GUI thread. When the asynchronous action is scheduled, your code continues. Some time later (you don't know exactly when) your asynchronous action will be executed
Invoke() will execute your asynchronous action (on the GUI thread) and wait until your action has completed.

A logical conclusion is that a delegate you pass to Invoke() can have out-parameters or a return-value, while a delegate you pass to BeginInvoke() cannot (you have to use EndInvoke to retrieve the results).

String to Dictionary in Python

Use ast.literal_eval to evaluate Python literals. However, what you have is JSON (note "true" for example), so use a JSON deserializer.

>>> import json
>>> s = """{"id":"123456789","name":"John Doe","first_name":"John","last_name":"Doe","link":"http:\/\/www.facebook.com\/jdoe","gender":"male","email":"jdoe\u0040gmail.com","timezone":-7,"locale":"en_US","verified":true,"updated_time":"2011-01-12T02:43:35+0000"}"""
>>> json.loads(s)
{u'first_name': u'John', u'last_name': u'Doe', u'verified': True, u'name': u'John Doe', u'locale': u'en_US', u'gender': u'male', u'email': u'[email protected]', u'link': u'http://www.facebook.com/jdoe', u'timezone': -7, u'updated_time': u'2011-01-12T02:43:35+0000', u'id': u'123456789'}

Save child objects automatically using JPA Hibernate

Here are the ways to assign parent object in child object of Bi-directional relations ?

Suppose you have a relation say One-To-Many,then for each parent object,a set of child object exists. In bi-directional relations,each child object will have reference to its parent.

eg : Each Department will have list of Employees and each Employee is part of some department.This is called Bi directional relations.

To achieve this, one way is to assign parent in child object while persisting parent object

Parent parent = new Parent();
...
Child c1 = new Child();
...
c1.setParent(parent);

List<Child> children = new ArrayList<Child>();
children.add(c1);
parent.setChilds(children);

session.save(parent);

Other way is, you can do using hibernate Intercepter,this way helps you not to write above code for all models.

Hibernate interceptor provide apis to do your own work before perform any DB operation.Likewise onSave of object, we can assign parent object in child objects using reflection.

public class CustomEntityInterceptor extends EmptyInterceptor {

    @Override
    public boolean onSave(
            final Object entity, final Serializable id, final Object[] state, final String[] propertyNames,
            final Type[] types) {
        if (types != null) {
            for (int i = 0; i < types.length; i++) {
                if (types[i].isCollectionType()) {
                    String propertyName = propertyNames[i];
                    propertyName = propertyName.substring(0, 1).toUpperCase() + propertyName.substring(1);
                    try {
                        Method method = entity.getClass().getMethod("get" + propertyName);
                        List<Object> objectList = (List<Object>) method.invoke(entity);

                        if (objectList != null) {
                            for (Object object : objectList) {
                                String entityName = entity.getClass().getSimpleName();
                                Method eachMethod = object.getClass().getMethod("set" + entityName, entity.getClass());
                                eachMethod.invoke(object, entity);
                            }
                        }

                    } catch (NoSuchMethodException | InvocationTargetException | IllegalAccessException e) {
                        throw new RuntimeException(e);
                    }
                }
            }
        }
        return true;
    }

}

And you can register Intercepter to configuration as

new Configuration().setInterceptor( new CustomEntityInterceptor() );

Subscript out of bounds - general definition and solution?

Only an addition to the above responses: A possibility in such cases is that you are calling an object, that for some reason is not available to your query. For example you may subset by row names or column names, and you will receive this error message when your requested row or column is not part of the data matrix or data frame anymore. Solution: As a short version of the responses above: you need to find the last working row name or column name, and the next called object should be the one that could not be found. If you run parallel codes like "foreach", then you need to convert your code to a for loop to be able to troubleshoot it.

HTML entity for check mark

HTML and XML entities are just a way of referencing a Unicode code-point in a way that reliably works regardless of the encoding of the actual page, making them useful for using esoteric Unicode characters in a page using 7-bit ASCII or some other encoding scheme, ideally on a one-off basis. They're also used to escape the <, >, " and & characters as these are reserved in SGML.

Anyway, Unicode has a number of tick/check characters, as per Wikipedia ( http://en.wikipedia.org/wiki/Tick_(check_mark) ).

Ideally you should save/store your HTML in a Unicode format like UTF-8 or 16, thus obviating the need to use HTML entities to represent a Unicode character. Nonetheless use: ✔ ✔.

&#x2714;

✔

Is using hex notation and is the same as

$#10004;

(as 2714 in base 16 is the same as 10004 in base 10)

Programs & Examples On #Echo

Is there a php echo/print equivalent in javascript

Multi-line string with extra space (preserved indentation)

How to use css style in php

Simplest way to display current month and year like "Aug 2016" in PHP?

PHP: How do I display the contents of a textfile on my page?

How to flush output after each `echo` call?

How to format font style and color in echo

Echo newline in Bash prints literal \n

How can I repeat a character in Bash?

Echo off but messages are displayed

How to use shell commands in Makefile

Echo tab characters in bash script

How to change the output color of echo in Linux

PHP Echo text Color

How does one output bold text in Bash?

How to echo in PHP, HTML tags

How can I echo the whole content of a .html file in PHP?

php - insert a variable in an echo string

using batch echo with special characters

PHP to search within txt file and echo the whole line

echo key and value of an array without and with loop

Echo a blank (empty) line to the console from a Windows batch file

How can I align the columns of tables in Bash?

How do I print all POST results when a form is submitted?

How do I make a Windows batch script completely silent?

How are echo and print different in PHP?

Bash: Echoing a echo command with a variable in bash

Add php variable inside echo statement as href link address?

How can I echo HTML in PHP?

How to echo JSON in PHP

Double quotes within php script echo

How can I suppress all output from a command using Bash?

Better solution without exluding fields from Binding

Bootstrap Modal Backdrop Remaining

How to use data-dismiss attribute

Stop setInterval

Server unable to read htaccess file, denying access to be safe

To switch from vertical split to horizontal split fast in Vim

repaint() in Java

Use the auto keyword in C++ STL

Get the list of stored procedures created and / or modified on a particular date?

How can I tell jackson to ignore a property for which I don't have control over the source code?

How to handle :java.util.concurrent.TimeoutException: android.os.BinderProxy.finalize() timed out after 10 seconds errors?

How to subtract/add days from/to a date?

JQuery ajax call default timeout value

How to create json by JavaScript for loop?

JavaScript: get code to run every minute

how to get file path from sd card in android

Create a root password for PHPMyAdmin

How to make function decorators and chain them together?

Decorator Basics

Python’s functions are objects

Functions references

Handcrafted decorators

Decorators demystified

Now: to answer the question...

Taking decorators to the next level

Passing arguments to the decorated function

Decorating methods

Passing arguments to the decorator

Let’s practice: decorating a decorator

Best practices: decorators

How can the decorators be useful?

OpenCV NoneType object has no attribute shape

how to set mongod --dbpath

What is the best way to get the count/length/size of an iterator?

How to Get a Specific Column Value from a DataTable?

How should I choose an authentication library for CodeIgniter?

How do I include a Perl module that's in a different directory?

SQL Statement using Where clause with multiple values

What is the purpose of Order By 1 in SQL select statement?

How to skip the first n rows in sql query

Gson - convert from Json to a typed ArrayList<T>

Can Android Studio be used to run standard Java projects?

'uint32_t' identifier not found error

Do I need to pass the full path of a file in another directory to open()?

Mac SQLite editor

How to pause a YouTube player when hiding the iframe?

Using PHP with Socket.io