Programs & Examples On #Substance

Substance is a modern, customizable and high-performing look & feel for Java applications that use the Swing UI toolkit. This look & feel is available for Java 8+ and is being developed by Kirill Grouchnikov.

#1292 - Incorrect date value: '0000-00-00'

After reviewing MySQL 5.7 changes, MySql stopped supporting zero values in date / datetime.

It's incorrect to use zeros in date or in datetime, just put null instead of zeros.

long long int vs. long int vs. int64_t in C++

Do you want to know if a type is the same type as int64_t or do you want to know if something is 64 bits? Based on your proposed solution, I think you're asking about the latter. In that case, I would do something like

template<typename T>
bool is_64bits() { return sizeof(T) * CHAR_BIT == 64; } // or >= 64

CSS: 100% width or height while keeping aspect ratio?

Nowadays one can use vw and vh units, which represent 1% of the viewport's width and height respectively.

https://css-tricks.com/fun-viewport-units/

So, for example:

img {
  max-width: 100vw;
  max-height: 100vh;
}

... will make the image as wide as tall as possible, maintaining aspect ratio, but without being wider or higher than 100% of the viewport.

How to find difference between two Joda-Time DateTimes in minutes

Something like...

Minutes.minutesBetween(getStart(), getEnd()).getMinutes();

Android: Bitmaps loaded from gallery are rotated in ImageView

The cursor should be closed after opening it.

Here is an example.

 public static int getOrientation(Context context, Uri selectedImage)
{
    int orientation = -1;
    Cursor cursor = context.getContentResolver().query(selectedImage,
            new String[] { MediaStore.Images.ImageColumns.ORIENTATION }, null, null, null);
    if (cursor.getCount() != 1)
       return orientation;

    cursor.moveToFirst();
    orientation = cursor.getInt(0);
    cursor.close(); // ADD THIS LINE
   return orientation;
}

@Autowired - No qualifying bean of type found for dependency

  • One reason BeanB may not exist in the context
  • Another cause for the exception is the existence of two bean
  • Or definitions in the context bean that isn’t defined is requested by name from the Spring context

see more this url:

http://www.baeldung.com/spring-nosuchbeandefinitionexception

How can I find the current OS in Python?

If you want user readable data but still detailed, you can use platform.platform()

>>> import platform
>>> platform.platform()
'Linux-3.3.0-8.fc16.x86_64-x86_64-with-fedora-16-Verne'

platform also has some other useful methods:

>>> platform.system()
'Windows'
>>> platform.release()
'XP'
>>> platform.version()
'5.1.2600'

Here's a few different possible calls you can make to identify where you are

import platform
import sys

def linux_distribution():
  try:
    return platform.linux_distribution()
  except:
    return "N/A"

print("""Python version: %s
dist: %s
linux_distribution: %s
system: %s
machine: %s
platform: %s
uname: %s
version: %s
mac_ver: %s
""" % (
sys.version.split('\n'),
str(platform.dist()),
linux_distribution(),
platform.system(),
platform.machine(),
platform.platform(),
platform.uname(),
platform.version(),
platform.mac_ver(),
))

The outputs of this script ran on a few different systems (Linux, Windows, Solaris, MacOS) and architectures (x86, x64, Itanium, power pc, sparc) is available here: https://github.com/hpcugent/easybuild/wiki/OS_flavor_name_version

e.g. Solaris on sparc gave:

Python version: ['2.6.4 (r264:75706, Aug  4 2010, 16:53:32) [C]']
dist: ('', '', '')
linux_distribution: ('', '', '')
system: SunOS
machine: sun4u
platform: SunOS-5.9-sun4u-sparc-32bit-ELF
uname: ('SunOS', 'xxx', '5.9', 'Generic_122300-60', 'sun4u', 'sparc')
version: Generic_122300-60
mac_ver: ('', ('', '', ''), '')

Extension exists but uuid_generate_v4 fails

#1 Re-install uuid-ossp extention in an exact schema:

SET search_path TO public;
DROP EXTENSION IF EXISTS "uuid-ossp";

CREATE EXTENSION "uuid-ossp" SCHEMA public;

If this is a fresh installation you can skip SET and DROP. Credits to @atomCode (details)

After this, you should see uuid_generate_v4() function IN THE RIGHT SCHEMA (when execute \df query in psql command-line prompt).

#2 Use fully-qualified names (with schemaname. qualifier):

CREATE TABLE public.my_table (
    id uuid DEFAULT public.uuid_generate_v4() NOT NULL,

Python strip() multiple characters?

Because strip() only strips trailing and leading characters, based on what you provided. I suggest:

>>> import re
>>> name = "Barack (of Washington)"
>>> name = re.sub('[\(\)\{\}<>]', '', name)
>>> print(name)
Barack of Washington

Close window automatically after printing dialog closes

Just wrap window.close by onafterprint event handler, it worked for me

printWindow.print();
printWindow.onafterprint = () => printWindow.close();

How can you tell if a value is not numeric in Oracle?

The best answer I found on internet:

SELECT case when trim(TRANSLATE(col1, '0123456789-,.', ' ')) is null
            then 'numeric'
            else 'alpha'
       end
FROM tab1;

How to set HTML5 required attribute in Javascript?

Short version

element.setAttribute("required", "");    //turns required on
element.required = true;                 //turns required on through reflected attribute
jQuery(element).attr('required', '');    //turns required on
$("#elementId").attr('required', '');    //turns required on

element.removeAttribute("required");     //turns required off
element.required = false;                //turns required off through reflected attribute
jQuery(element).removeAttr('required');  //turns required off
$("#elementId").removeAttr('required');  //turns required off

if (edName.hasAttribute("required")) { }  //check if required
if (edName.required) { }                 //check if required using reflected attribute

Long Version

Once T.J. Crowder managed to point out reflected properties, i learned that following syntax is wrong:

element.attributes["name"] = value; //bad! Overwrites the HtmlAttribute object
element.attributes.name = value;    //bad! Overwrites the HtmlAttribute object
value = element.attributes.name;    //bad! Returns the HtmlAttribute object, not its value
value = element.attributes["name"]; //bad! Returns the HtmlAttribute object, not its value

You must go through element.getAttribute and element.setAttribute:

element.getAttribute("foo");         //correct
element.setAttribute("foo", "test"); //correct

This is because the attribute actually contains a special HtmlAttribute object:

element.attributes["foo"];           //returns HtmlAttribute object, not the value of the attribute
element.attributes.foo;              //returns HtmlAttribute object, not the value of the attribute

By setting an attribute value to "true", you are mistakenly setting it to a String object, rather than the HtmlAttribute object it requires:

element.attributes["foo"] = "true";  //error because "true" is not a HtmlAttribute object
element.setAttribute("foo", "true"); //error because "true" is not an HtmlAttribute object

Conceptually the correct idea (expressed in a typed language), is:

HtmlAttribute attribute = new HtmlAttribute();
attribute.value = "";
element.attributes["required"] = attribute;

This is why:

  • getAttribute(name)
  • setAttribute(name, value)

exist. They do the work on assigning the value to the HtmlAttribute object inside.

On top of this, some attribute are reflected. This means that you can access them more nicely from Javascript:

//Set the required attribute
//element.setAttribute("required", ""); 
element.required = true;

//Check the attribute
//if (element.getAttribute("required")) {...}
if (element.required) {...}

//Remove the required attribute
//element.removeAttribute("required");
element.required = false;

What you don't want to do is mistakenly use the .attributes collection:

element.attributes.required = true;     //WRONG!
if (element.attributes.required) {...}  //WRONG!
element.attributes.required = false;    //WRONG!

Testing Cases

This led to testing around the use of a required attribute, comparing the values returned through the attribute, and the reflected property

document.getElementById("name").required;
document.getElementById("name").getAttribute("required");

with results:

HTML                         .required        .getAttribute("required")
==========================   ===============  =========================
<input>                      false (Boolean)  null (Object)
<input required>             true  (Boolean)  "" (String)
<input required="">          true  (Boolean)  "" (String)
<input required="required">  true  (Boolean)  "required" (String)
<input required="true">      true  (Boolean)  "true" (String)
<input required="false">     true  (Boolean)  "false" (String)
<input required="0">         true  (Boolean)  "0" (String)

Trying to access the .attributes collection directly is wrong. It returns the object that represents the DOM attribute:

edName.attributes["required"] => [object Attr]
edName.attributes.required    => [object Attr]

This explains why you should never talk to the .attributes collect directly. You're not manipulating the values of the attributes, but the objects that represent the attributes themselves.

How to set required?

What's the correct way to set required on an attribute? You have two choices, either the reflected property, or through correctly setting the attribute:

element.setAttribute("required", "");         //Correct
edName.required = true;                       //Correct

Strictly speaking, any other value will "set" the attribute. But the definition of Boolean attributes dictate that it should only be set to the empty string "" to indicate true. The following methods all work to set the required Boolean attribute,

but do not use them:

element.setAttribute("required", "required"); //valid, but not preferred
element.setAttribute("required", "foo");      //works, but silly
element.setAttribute("required", "true");     //Works, but don't do it, because:
element.setAttribute("required", "false");    //also sets required boolean to true
element.setAttribute("required", false);      //also sets required boolean to true
element.setAttribute("required", 0);          //also sets required boolean to true

We already learned that trying to set the attribute directly is wrong:

edName.attributes["required"] = true;       //wrong
edName.attributes["required"] = "";         //wrong
edName.attributes["required"] = "required"; //wrong
edName.attributes.required = true;          //wrong
edName.attributes.required = "";            //wrong
edName.attributes.required = "required";    //wrong

How to clear required?

The trick when trying to remove the required attribute is that it's easy to accidentally turn it on:

edName.removeAttribute("required");     //Correct
edName.required = false;                //Correct

With the invalid ways:

edName.setAttribute("required", null);    //WRONG! Actually turns required on!
edName.setAttribute("required", "");      //WRONG! Actually turns required on!
edName.setAttribute("required", "false"); //WRONG! Actually turns required on!
edName.setAttribute("required", false);   //WRONG! Actually turns required on!
edName.setAttribute("required", 0);       //WRONG! Actually turns required on!

When using the reflected .required property, you can also use any "falsey" values to turn it off, and truthy values to turn it on. But just stick to true and false for clarity.

How to check for required?

Check for the presence of the attribute through the .hasAttribute("required") method:

if (edName.hasAttribute("required"))
{
}

You can also check it through the Boolean reflected .required property:

if (edName.required)
{
}

Remove characters after specific character in string, then remove substring?

you can use .NET's built in method to remove the QueryString. i.e., Request.QueryString.Remove["whatever"];

here whatever in the [ ] is name of the querystring which you want to remove.

Try this... I hope this will help.

How to insert date values into table

Since dob is DATE data type, you need to convert the literal to DATE using TO_DATE and the proper format model. The syntax is:

TO_DATE('<date_literal>', '<format_model>')

For example,

SQL> CREATE TABLE t(dob DATE);

Table created.

SQL> INSERT INTO t(dob) VALUES(TO_DATE('17/12/2015', 'DD/MM/YYYY'));

1 row created.

SQL> COMMIT;

Commit complete.

SQL> SELECT * FROM t;

DOB
----------
17/12/2015

A DATE data type contains both date and time elements. If you are not concerned about the time portion, then you could also use the ANSI Date literal which uses a fixed format 'YYYY-MM-DD' and is NLS independent.

For example,

SQL> INSERT INTO t(dob) VALUES(DATE '2015-12-17');

1 row created.

Use 'import module' or 'from module import'?

I would like to add to this, there are somethings to consider during the import calls:

I have the following structure:

mod/
    __init__.py
    main.py
    a.py
    b.py
    c.py
    d.py

main.py:

import mod.a
import mod.b as b
from mod import c
import d

dis.dis shows the difference:

  1           0 LOAD_CONST               0 (-1)
              3 LOAD_CONST               1 (None)
              6 IMPORT_NAME              0 (mod.a)
              9 STORE_NAME               1 (mod)

  2          12 LOAD_CONST               0 (-1)
             15 LOAD_CONST               1 (None)
             18 IMPORT_NAME              2 (b)
             21 STORE_NAME               2 (b)

  3          24 LOAD_CONST               0 (-1)
             27 LOAD_CONST               2 (('c',))
             30 IMPORT_NAME              1 (mod)
             33 IMPORT_FROM              3 (c)
             36 STORE_NAME               3 (c)
             39 POP_TOP

  4          40 LOAD_CONST               0 (-1)
             43 LOAD_CONST               1 (None)
             46 IMPORT_NAME              4 (mod.d)
             49 LOAD_ATTR                5 (d)
             52 STORE_NAME               5 (d)
             55 LOAD_CONST               1 (None)

In the end they look the same (STORE_NAME is result in each example), but this is worth noting if you need to consider the following four circular imports:

example1

foo/
   __init__.py
   a.py
   b.py
a.py:
import foo.b 
b.py:
import foo.a
>>> import foo.a
>>>

This works

example2

bar/
   __init__.py
   a.py
   b.py
a.py:
import bar.b as b
b.py:
import bar.a as a
>>> import bar.a
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "bar\a.py", line 1, in <module>
    import bar.b as b
  File "bar\b.py", line 1, in <module>
    import bar.a as a
AttributeError: 'module' object has no attribute 'a'

No dice

example3

baz/
   __init__.py
   a.py
   b.py
a.py:
from baz import b
b.py:
from baz import a
>>> import baz.a
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "baz\a.py", line 1, in <module>
    from baz import b
  File "baz\b.py", line 1, in <module>
    from baz import a
ImportError: cannot import name a

Similar issue... but clearly from x import y is not the same as import import x.y as y

example4

qux/
   __init__.py
   a.py
   b.py
a.py:
import b 
b.py:
import a
>>> import qux.a
>>>

This one also works

Using python's mock patch.object to change the return value of a method called within another method

Let me clarify what you're talking about: you want to test Foo in a testcase, which calls external method uses_some_other_method. Instead of calling the actual method, you want to mock the return value.

class Foo:
    def method_1():
       results = uses_some_other_method()
    def method_n():
       results = uses_some_other_method()

Suppose the above code is in foo.py and uses_some_other_method is defined in module bar.py. Here is the unittest:

import unittest
import mock

from foo import Foo


class TestFoo(unittest.TestCase):

    def setup(self):
        self.foo = Foo()

    @mock.patch('foo.uses_some_other_method')
    def test_method_1(self, mock_method):
        mock_method.return_value = 3
        self.foo.method_1(*args, **kwargs)

        mock_method.assert_called_with(*args, **kwargs)

If you want to change the return value every time you passed in different arguments, mock provides side_effect.

MySQL load NULL values from CSV data

This will do what you want. It reads the fourth field into a local variable, and then sets the actual field value to NULL, if the local variable ends up containing an empty string:

LOAD DATA INFILE '/tmp/testdata.txt'
INTO TABLE moo
FIELDS TERMINATED BY ","
LINES TERMINATED BY "\n"
(one, two, three, @vfour, five)
SET four = NULLIF(@vfour,'')
;

If they're all possibly empty, then you'd read them all into variables and have multiple SET statements, like this:

LOAD DATA INFILE '/tmp/testdata.txt'
INTO TABLE moo
FIELDS TERMINATED BY ","
LINES TERMINATED BY "\n"
(@vone, @vtwo, @vthree, @vfour, @vfive)
SET
one = NULLIF(@vone,''),
two = NULLIF(@vtwo,''),
three = NULLIF(@vthree,''),
four = NULLIF(@vfour,'')
;

Error 6 (net::ERR_FILE_NOT_FOUND): The files c or directory could not be found

If this is an HTML file where you are using file://FileName then using a CDN like src="//cdnjs.cloudflare.com/ajax/libs/angular.js/1.2.1/angular.min.js" will not work.

You will have to include the .js file in your code.

adding x and y axis labels in ggplot2

[Note: edited to modernize ggplot syntax]

Your example is not reproducible since there is no ex1221new (there is an ex1221 in Sleuth2, so I guess that is what you meant). Also, you don't need (and shouldn't) pull columns out to send to ggplot. One advantage is that ggplot works with data.frames directly.

You can set the labels with xlab() and ylab(), or make it part of the scale_*.* call.

library("Sleuth2")
library("ggplot2")
ggplot(ex1221, aes(Discharge, Area)) +
  geom_point(aes(size=NO3)) + 
  scale_size_area() + 
  xlab("My x label") +
  ylab("My y label") +
  ggtitle("Weighted Scatterplot of Watershed Area vs. Discharge and Nitrogen Levels (PPM)")

enter image description here

ggplot(ex1221, aes(Discharge, Area)) +
  geom_point(aes(size=NO3)) + 
  scale_size_area("Nitrogen") + 
  scale_x_continuous("My x label") +
  scale_y_continuous("My y label") +
  ggtitle("Weighted Scatterplot of Watershed Area vs. Discharge and Nitrogen Levels (PPM)")

enter image description here

An alternate way to specify just labels (handy if you are not changing any other aspects of the scales) is using the labs function

ggplot(ex1221, aes(Discharge, Area)) +
  geom_point(aes(size=NO3)) + 
  scale_size_area() + 
  labs(size= "Nitrogen",
       x = "My x label",
       y = "My y label",
       title = "Weighted Scatterplot of Watershed Area vs. Discharge and Nitrogen Levels (PPM)")

which gives an identical figure to the one above.

Angular, content type is not being sent with $http

         $http({
                method: 'GET',
                url:'/http://localhost:8080/example/test' + toto,
                data: '',
                headers: {
                    'Content-Type': 'application/json'
                }
            }).then(
                function(response) {
                    return response.data;
                }, 
                function(errResponse) {
                    console.error('Error !!');
                    return $q.reject(errResponse);
                }

How can I scan barcodes on iOS?

As with the release of iOS7 you no longer need to use an external framework or library. The iOS ecosystem with AVFoundation now fully supports scanning almost every code from QR over EAN to UPC.

Just have a look at the Tech Note and the AVFoundation programming guide. AVMetadataObjectTypeQRCode is your friend.

Here is a nice tutorial which shows it step by step: iPhone QR code scan library iOS7

Just a little example on how to set it up:

#pragma mark -
#pragma mark AVFoundationScanSetup

- (void) setupScanner;
{
    self.device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    self.input = [AVCaptureDeviceInput deviceInputWithDevice:self.device error:nil];

    self.session = [[AVCaptureSession alloc] init];

    self.output = [[AVCaptureMetadataOutput alloc] init];
    [self.session addOutput:self.output];
    [self.session addInput:self.input];

    [self.output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
    self.output.metadataObjectTypes = @[AVMetadataObjectTypeQRCode];

    self.preview = [AVCaptureVideoPreviewLayer layerWithSession:self.session];
    self.preview.videoGravity = AVLayerVideoGravityResizeAspectFill;
    self.preview.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);

    AVCaptureConnection *con = self.preview.connection;

    con.videoOrientation = AVCaptureVideoOrientationLandscapeLeft;

    [self.view.layer insertSublayer:self.preview atIndex:0];
}

Windows 7 SDK installation failure

One of the things to also keep in mind is that when you have Visual Studio 2010 SP1 installed some C++ compilers and libraries may have been removed. There's been an update made available by Microsoft to make sure those are brought back to your system.

Install this update to restore the Visual C++ compilers and libraries that may have been removed when Visual Studio 2010 Service Pack 1 (SP1) was installed. The compilers and libraries are part of the Microsoft Windows Software Development Kit for Windows 7 and the .NET Framework 4 (later referred to as the Windows SDK 7.1).

Also, when you read the VS2010 SP1 README you'll also notice that some notes have been made in regards to the Windows 7 SDK (See section 2.2.1) installation. It may be that one of these conditions may apply to you and therefore may need to uncheck the C++ compiler-checkbox as the SDK installer will attempt to install an older version of compilers ÓR you may need to uninstall VS2010 SP1 and re-run the SDK 7.1 installation, repair or modification.

Condition 1: If the Visual C++ Compilers checkbox is selected when the Windows SDK 7.1 is installed, repaired, or modified after Visual Studio 2010 SP1 has been installed, the error may be encountered and some selected components may not be installed.

Workaround: Clear the Visual C++ Compilers checkbox before you run the Windows SDK 7.1 installation, repair, or modification.

Condition 2: If the Visual C++ Compilers checkbox is selected when the Windows SDK 7.1 is installed, repaired, or modified after Visual Studio 2010 has been installed but Visual Studio 2010 SP1 has not been uninstalled, the error may be encountered.

Workaround: Uninstall Visual Studio 2010 SP1 and then rerun the Windows SDK 7.1 installation, repair, or modification.

However, even then I found that I still needed to uninstall any existing Visual C++ 2010 redistributables, as has been suggested by mgrandi.

Python: Open file in zip without temporarily extracting it

import io, pygame, zipfile
archive = zipfile.ZipFile('images.zip', 'r')

# read bytes from archive
img_data = archive.read('img_01.png')

# create a pygame-compatible file-like object from the bytes
bytes_io = io.BytesIO(img_data)

img = pygame.image.load(bytes_io)

I was trying to figure this out for myself just now and thought this might be useful for anyone who comes across this question in the future.

Parsing a comma-delimited std::string

Input one number at a time, and check whether the following character is ,. If so, discard it.

#include <vector>
#include <string>
#include <sstream>
#include <iostream>

int main()
{
    std::string str = "1,2,3,4,5,6";
    std::vector<int> vect;

    std::stringstream ss(str);

    for (int i; ss >> i;) {
        vect.push_back(i);    
        if (ss.peek() == ',')
            ss.ignore();
    }

    for (std::size_t i = 0; i < vect.size(); i++)
        std::cout << vect[i] << std::endl;
}

Git/GitHub can't push to master

Mark Longair's solution using git remote set-url... is quite clear. You can also get the same behavior by directly editing this section of the .git/config file:

before:

[remote "origin"]
    fetch = +refs/heads/*:refs/remotes/origin/*
    url = git://github.com/my_user_name/my_repo.git

after:

[remote "origin"]
    fetch = +refs/heads/*:refs/remotes/origin/*
    url = [email protected]:my_user_name/my_repo.git

(And conversely, the git remote set-url... invocation produces the above change.)

Registering for Push Notifications in Xcode 8/Swift 3.0?

The answer from ast1 is very simple and useful. It works for me, thank you so much. I just want to poin it out here, so people who need this answer can find it easily. So, here is my code from registering local and remote (push) notification.

    //1. In Appdelegate: didFinishLaunchingWithOptions add these line of codes
    let mynotif = UNUserNotificationCenter.current()
    mynotif.requestAuthorization(options: [.alert, .sound, .badge]) {(granted, error) in }//register and ask user's permission for local notification

    //2. Add these functions at the bottom of your AppDelegate before the last "}"
    func application(_ application: UIApplication, didRegister notificationSettings: UNNotificationSettings) {
        application.registerForRemoteNotifications()//register for push notif after users granted their permission for showing notification
}
    func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
    let tokenString = deviceToken.reduce("", {$0 + String(format: "%02X", $1)})
    print("Device Token: \(tokenString)")//print device token in debugger console
}
    func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
    print("Failed to register: \(error)")//print error in debugger console
}

Copy folder recursively, excluding some folders

EXCLUDE="foo bar blah jah"                                                                             
DEST=$1

for i in *
do
    for x in $EXCLUDE
    do  
        if [ $x != $i ]; then
            cp -a $i $DEST
        fi  
    done
done

Untested...

Truncate all tables in a MySQL database in one command?

No. There is no single command to truncate all mysql tables at once. You will have to create a small script to truncate the tables one by one.

ref: http://dev.mysql.com/doc/refman/5.0/en/truncate-table.html

How can I add the sqlite3 module to Python?

Normally, it is included. However, as @ngn999 said, if your python has been built from source manually, you'll have to add it.

Here is an example of a script that will setup an encapsulated version (virtual environment) of Python3 in your user directory with an encapsulated version of sqlite3.

INSTALL_BASE_PATH="$HOME/local"
cd ~
mkdir build
cd build
[ -f Python-3.6.2.tgz ] || wget https://www.python.org/ftp/python/3.6.2/Python-3.6.2.tgz
tar -zxvf Python-3.6.2.tgz

[ -f sqlite-autoconf-3240000.tar.gz ] || wget https://www.sqlite.org/2018/sqlite-autoconf-3240000.tar.gz
tar -zxvf sqlite-autoconf-3240000.tar.gz

cd sqlite-autoconf-3240000
./configure --prefix=${INSTALL_BASE_PATH}
make
make install

cd ../Python-3.6.2
LD_RUN_PATH=${INSTALL_BASE_PATH}/lib configure
LDFLAGS="-L ${INSTALL_BASE_PATH}/lib"
CPPFLAGS="-I ${INSTALL_BASE_PATH}/include"
LD_RUN_PATH=${INSTALL_BASE_PATH}/lib make
./configure --prefix=${INSTALL_BASE_PATH}
make
make install

cd ~
LINE_TO_ADD="export PATH=${INSTALL_BASE_PATH}/bin:\$PATH"
if grep -q -v "${LINE_TO_ADD}" $HOME/.bash_profile; then echo "${LINE_TO_ADD}" >> $HOME/.bash_profile; fi
source $HOME/.bash_profile

Why do this? You might want a modular python environment that you can completely destroy and rebuild without affecting your managed package installation. This would give you an independent development environment. In this case, the solution is to install sqlite3 modularly too.

Selenium and xPath - locating a link by containing text

Use this

//*[@id='popover-search']/div/div/ul/li[1]/a/span[contains(text(),'Some text')]

OR

//*[@id='popover-search']/div/div/ul/li[1]/a/span[contains(.,'Some text')]

What's the difference between fill_parent and wrap_content?

Either attribute can be applied to View's (visual control) horizontal or vertical size. It's used to set a View or Layouts size based on either it's contents or the size of it's parent layout rather than explicitly specifying a dimension.

fill_parent (deprecated and renamed MATCH_PARENT in API Level 8 and higher)

Setting the layout of a widget to fill_parent will force it to expand to take up as much space as is available within the layout element it's been placed in. It's roughly equivalent of setting the dockstyle of a Windows Form Control to Fill.

Setting a top level layout or control to fill_parent will force it to take up the whole screen.

wrap_content

Setting a View's size to wrap_content will force it to expand only far enough to contain the values (or child controls) it contains. For controls -- like text boxes (TextView) or images (ImageView) -- this will wrap the text or image being shown. For layout elements it will resize the layout to fit the controls / layouts added as its children.

It's roughly the equivalent of setting a Windows Form Control's Autosize property to True.

Online Documentation

There's some details in the Android code documentation here.

How to add an onchange event to a select box via javascript?

yourSelect.setAttribute( "onchange", "yourFunction()" );

Bootstrap date and time picker

If you are still interested in a javascript api to select both date and time data, have a look at these projects which are forks of bootstrap datepicker:

The first fork is a big refactor on the parsing/formatting codebase and besides providing all views to select date/time using mouse/touch, it also has a mask option (by default) which lets the user to quickly type the date/time based on a pre-specified format.

How to Select Columns in Editors (Atom,Notepad++, Kate, VIM, Sublime, Textpad,etc) and IDEs (NetBeans, IntelliJ IDEA, Eclipse, Visual Studio, etc)

In Flash Builder (v 4.5 and up), and Aptana Studio (at least v 2.0.5) there is a toolbar button to toggle block select. It is between the 'mark occurrences' and 'show whitespace characters' buttons. There is also a Alt + Shift + A shortcut. Not surprisingly, this is basically the same as for Eclipse, but I'm including here for completeness.

Syntax for async arrow function

Async arrow functions look like this:

const foo = async () => {
  // do something
}

Async arrow functions look like this for a single argument passed to it:

const foo = async evt => {
  // do something with evt
}

Async arrow functions look like this for multiple arguments passed to it:

const foo = async (evt, callback) => {
  // do something with evt
  // return response with callback
}

The anonymous form works as well:

const foo = async function() {
  // do something
}

An async function declaration looks like this:

async function foo() {
  // do something
}

Using async function in a callback:

const foo = event.onCall(async () => {
  // do something
})

Shell script to set environment variables

Please show us more parts of the script and tell us what commands you had to individually execute and want to simply.

Meanwhile you have to use double quotes not single quote to expand variables:

export PATH="/home/linux/Practise/linux-devkit/bin/:$PATH"

Semicolons at the end of a single command are also unnecessary.

So far:

#!/bin/sh
echo "Perform Operation in su mode"
export ARCH=arm
echo "Export ARCH=arm Executed"
export PATH="/home/linux/Practise/linux-devkit/bin/:$PATH"
echo "Export path done"
export CROSS_COMPILE='/home/linux/Practise/linux-devkit/bin/arm-arago-linux-gnueabi-' ## What's next to -?
echo "Export CROSS_COMPILE done"
# continue your compilation commands here
...

For su you can run it with:

su -c 'sh /path/to/script.sh'

Note: The OP was not explicitly asking for steps on how to create export variables in an interactive shell using a shell script. He only asked his script to be assessed at most. He didn't mention details on how his script would be used. It could have been by using . or source from the interactive shell. It could have been a standalone scipt, or it could have been source'd from another script. Environment variables are not specific to interactive shells. This answer solved his problem.

Working with TIFFs (import, export) in Python using numpy

In case of image stacks, I find it easier to use scikit-image to read, and matplotlib to show or save. I have handled 16-bit TIFF image stacks with the following code.

from skimage import io
import matplotlib.pyplot as plt

# read the image stack
img = io.imread('a_image.tif')
# show the image
plt.imshow(mol,cmap='gray')
plt.axis('off')
# save the image
plt.savefig('output.tif', transparent=True, dpi=300, bbox_inches="tight", pad_inches=0.0)

Forgot Oracle username and password, how to retrieve?

The usernames are shown in the dba_users's username column, there is a script you can run called:

alter user username identified by password

You can get more information here - https://community.oracle.com/thread/632617?tstart=0

How to find event listeners on a DOM node when debugging or from the JavaScript code?

If you have Firebug, you can use console.dir(object or array) to print a nice tree in the console log of any JavaScript scalar, array, or object.

Try:

console.dir(clickEvents);

or

console.dir(window);

sys.stdin.readline() reads without prompt, returning 'nothing in between'

If you need just one character and you don't want to keep things in the buffer, you can simply read a whole line and drop everything that isn't needed.

Replace:

stdin.read(1)

with

stdin.readline().strip()[:1]

This will read a line, remove spaces and newlines and just keep the first character.

Volatile vs Static in Java

Difference Between Static and Volatile :

Static Variable: If two Threads(suppose t1 and t2) are accessing the same object and updating a variable which is declared as static then it means t1 and t2 can make their own local copy of the same object(including static variables) in their respective cache, so update made by t1 to the static variable in its local cache wont reflect in the static variable for t2 cache .

Static variables are used in the context of Object where update made by one object would reflect in all the other objects of the same class but not in the context of Thread where update of one thread to the static variable will reflect the changes immediately to all the threads (in their local cache).

Volatile variable: If two Threads(suppose t1 and t2) are accessing the same object and updating a variable which is declared as volatile then it means t1 and t2 can make their own local cache of the Object except the variable which is declared as a volatile . So the volatile variable will have only one main copy which will be updated by different threads and update made by one thread to the volatile variable will immediately reflect to the other Thread.

Difference between | and || or & and && for comparison

The & and | are usually bitwise operations.

Where as && and || are usually logical operations.

For comparison purposes, it's perfectly fine provided that everything returns either a 1 or a 0. Otherwise, it can return false positives. You should avoid this though to prevent hard to read bugs.

Wait for async task to finish

How about calling a function from within your callback instead of returning a value in sync_call()?

function sync_call(input) {
    var value;

    // Assume the async call always succeed
    async_call(input, function(result) {
        value = result;
        use_value(value);
    } );
}

What is href="#" and why is it used?

It's a link that links to nowhere essentially (it just adds "#" onto the URL). It's used for a number of different reasons. For instance, if you're using some sort of JavaScript/jQuery and don't want the actual HTML to link anywhere.

It's also used for page anchors, which is used to redirect to a different part of the page.

Why was the name 'let' chosen for block-scoped variable declarations in JavaScript?

It does exactly what the var does with a scope difference. Now it can not take the name var since that is already taken.

So it looks that it has taken the next best name which has a semantic in an interesting English language construct.

let myPet = 'dog';

In English it says "Let my pet be a dog"

OpenCV - Saving images to a particular folder of choice

Thank you everyone. Your ways are perfect. I would like to share another way I used to fix the problem. I used the function os.chdir(path) to change local directory to path. After which I saved image normally.

Error "The goal you specified requires a project to execute but there is no POM in this directory" after executing maven command

Check for the name of the file, i.e pom.xml file is spelled correctly with proper file extension .xml.

Example for this error are

pom.ml pm.xl

iOS 8 UITableView separator inset 0 not working

Just add below code can solve this program.

Good luck to you!

-(void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {

       if ([cell respondsToSelector:@selector(setSeparatorInset:)]) {
           [cell setSeparatorInset:UIEdgeInsetsZero];
       }

       if ([cell respondsToSelector:@selector(setLayoutMargins:)]) {
           [cell setLayoutMargins:UIEdgeInsetsZero];
       }

}

MySQL Cannot Add Foreign Key Constraint

In my case, there was a syntax error which was not explicitly notified by MySQL console upon running the query. However, SHOW ENGINE INNODB STATUS command's LATEST FOREIGN KEY ERROR section reported,

  Syntax error close to:

  REFERENCES`role`(`id`) ON DELETE CASCADE) ENGINE = InnoDB DEFAULT CHARSET = utf8

I had to leave a whitespace between REFERENCES and role to make it work.

Inserting HTML elements with JavaScript

You want this

document.body.insertAdjacentHTML( 'afterbegin', '<div id="myID">...</div>' );

How to find the remainder of a division in C?

All the above answers are correct. Just providing with your dataset to find perfect divisor:

#include <stdio.h>

int main() 
{

int arr[7] = {3,5,7,8,9,17,19};
int j = 51;
int i = 0;

for (i=0 ; i < 7; i++) {
    if (j % arr[i] == 0)
        printf("%d is the perfect divisor of %d\n", arr[i], j);
}

return 0;
}

How to submit a form with JavaScript by clicking a link?

If you use jQuery and would need an inline solution, this would work very well;

<a href="#" onclick="$(this).closest('form').submit();">submit form</a>

Also, you might want to replace

<a href="#">text</a>

with

<a href="javascript:void(0);">text</a>

so the user does not scroll to the top of your page when clicking the link.

Visual Studio Code - Target of URI doesn't exist 'package:flutter/material.dart'

Simple thing I did after Someone said here to restart the VSCode and I did that, and now everything works fine.

For me it was because just when I was creating project I got an notification for updating my dart(or related) extension and for that I did it and boom as my project started, it just gave me around 30 errors which do scared but the simple FIX was to RESTART THE EDITOR.

arranging div one below the other

The default behaviour of divs is to take the full width available in their parent container.
This is the same as if you'd give the inner divs a width of 100%.

By floating the divs, they ignore their default and size their width to fit the content. Everything behind it (in the HTML), is placed under the div (on the rendered page).
This is the reason that they align theirselves next to each other.

The float CSS property specifies that an element should be taken from the normal flow and placed along the left or right side of its container, where text and inline elements will wrap around it. A floating element is one where the computed value of float is not none.

Source: https://developer.mozilla.org/en-US/docs/Web/CSS/float

Get rid of the float, and the divs will be aligned under each other.
If this does not happen, you'll have some other css on divs or children of wrapper defining a floating behaviour or an inline display.

If you want to keep the float, for whatever reason, you can use clear on the 2nd div to reset the floating properties of elements before that element.
clear has 5 valid values: none | left | right | both | inherit. Clearing no floats (used to override inherited properties), left or right floats or both floats. Inherit means it'll inherit the behaviour of the parent element

Also, because of the default behaviour, you don't need to set the width and height on auto.
You only need this is you want to set a hardcoded height/width. E.g. 80% / 800px / 500em / ...

<div id="wrapper">
    <div id="inner1"></div>
    <div id="inner2"></div>
</div>

CSS is

#wrapper{
    margin-left:auto;
    margin-right:auto;
    height:auto; // this is not needed, as parent container, this div will size automaticly
    width:auto; // this is not needed, as parent container, this div will size automaticly
}

/*
You can get rid of the inner divs in the css, unless you want to style them.
If you want to style them identicly, you can use concatenation
*/
#inner1, #inner2 {
    border: 1px solid black;
}

Is there a short contains function for lists?

In addition to what other have said, you may also be interested to know that what in does is to call the list.__contains__ method, that you can define on any class you write and can get extremely handy to use python at his full extent.  

A dumb use may be:

>>> class ContainsEverything:
    def __init__(self):
        return None
    def __contains__(self, *elem, **k):
        return True


>>> a = ContainsEverything()
>>> 3 in a
True
>>> a in a
True
>>> False in a
True
>>> False not in a
False
>>>         

Android ListView Selector Color

TO ADD: @Christopher's answer does not work on API 7/8 (as per @Jonny's correct comment) IF you are using colours, instead of drawables. (In my testing, using drawables as per Christopher works fine)

Here is the FIX for 2.3 and below when using colours:

As per @Charles Harley, there is a bug in 2.3 and below where filling the list item with a colour causes the colour to flow out over the whole list. His fix is to define a shape drawable containing the colour you want, and to use that instead of the colour.

I suggest looking at this link if you want to just use a colour as selector, and are targeting Android 2 (or at least allow for Android 2).

Get file size before uploading

_x000D_
_x000D_
$(document).ready(function() {_x000D_
  $('#openFile').on('change', function(evt) {_x000D_
    console.log(this.files[0].size);_x000D_
  });_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<form action="upload.php" enctype="multipart/form-data" method="POST" id="uploadform">_x000D_
  <input id="openFile" name="img" type="file" />_x000D_
</form>
_x000D_
_x000D_
_x000D_

How to check if a row exists in MySQL? (i.e. check if an email exists in MySQL)

You have to execute your query and add single quote to $email in the query beacuse it's a string, and remove the is_resource($query) $query is a string, the $result will be the resource

$query = "SELECT `email` FROM `tblUser` WHERE `email` = '$email'";
$result = mysqli_query($link,$query); //$link is the connection

if(mysqli_num_rows($result) > 0 ){....}

UPDATE

Base in your edit just change:

if(is_resource($query) && mysqli_num_rows($query) > 0 ){
        $query = mysqli_fetch_assoc($query);
        echo $email . " email exists " .  $query["email"] . "\n";

By

if(is_resource($result) && mysqli_num_rows($result) == 1 ){
        $row = mysqli_fetch_assoc($result);
         echo $email . " email exists " .  $row["email"] . "\n";

and you will be fine

UPDATE 2

A better way should be have a Store Procedure that execute the following SQL passing the Email as Parameter

SELECT IF( EXISTS (
                  SELECT *
                  FROM `Table`
                  WHERE `email` = @Email)
          , 1, 0) as `Exist`

and retrieve the value in php

Pseudocodigo:

 $query = Call MYSQL_SP($EMAIL);
 $result = mysqli_query($conn,$query);
 $row = mysqli_fetch_array($result)
 $exist = ($row['Exist']==1)? 'the email exist' : 'the email doesnt exist';

How to check if function exists in JavaScript?

I always check like this:

if(!myFunction){return false;}

just place it before any code that uses this function

DataTables warning: Requested unknown parameter '0' from the data source for row '0'

I face this issue because I messed return keyword in custom rendering in Columns section

columns: [
    {....
        'data': function(row, type, val, meta) {
            if (row.LetterStatus)
                 return '@CultureHelper.GetCurrentCulture()' == 'ar'? row.LetterStatus.NameInArabic: row.LetterStatus.NameInEnglish;
            else row.LetterStatusID.toString();// here is the problem because I messed the Return key keyword
          },
     ......
    }

the problem in my code is because I messed the Return keyword in the else clause

so I changed it to

....
else return row.LetterStatusID.toString();// messed return keyword added
.....

How to add empty spaces into MD markdown readme on GitHub?

As a workaround, you can use a code block to render the code literally. Just surround your text with triple backticks ```. It will look like this:

2018-07-20 Wrote this answer Can format it without &nbsp; Also don't need <br /> for new line

Note that using <pre> and <code> you get slightly different behaviour: &nbsp and <br /> will be parsed rather than inserted literally.

<pre>:

2018-07-20 Wrote this answer
           Can format it without  
    Also don't need 
for new line

<code>: 2018-07-20 Wrote this answer Can format it without   Also don't need
for new line

Select max value of each group

SELECT
  b.name,
  MAX(b.value) as MaxValue,
  MAX(b.Anothercolumn) as AnotherColumn
FROM out_pumptabl
INNER JOIN (SELECT 
              name,
              MAX(value) as MaxValue
            FROM out_pumptabl
            GROUP BY Name) a ON 
  a.name = b.name AND a.maxValue = b.value
GROUP BY b.Name

Note this would be far easier if you had a primary key. Here is an Example

SELECT * FROM out_pumptabl c
WHERE PK in 
    (SELECT
      MAX(PK) as MaxPK
    FROM out_pumptabl b
    INNER JOIN (SELECT 
                  name,
                  MAX(value) as MaxValue
                FROM out_pumptabl
                GROUP BY Name) a ON 
      a.name = b.name AND a.maxValue = b.value) 

How do you install Boost on MacOS?

Fink appears to have a full set of Boost packages...

With fink installed and running just do

fink install boost1.35.nopython

at the terminal and accept the dependencies it insists on. Or use

fink list boost

to get a list of different packages that are availible.

When to use %r instead of %s in Python?

Use the %r for debugging, since it displays the "raw" data of the variable, but the others are used for displaying to users.

That's how %r formatting works; it prints it the way you wrote it (or close to it). It's the "raw" format for debugging. Here \n used to display to users doesn't work. %r shows the representation if the raw data of the variable.

months = "\nJan\nFeb\nMar\nApr\nMay\nJun\nJul\nAug"
print "Here are the months: %r" % months

Output:

Here are the months: '\nJan\nFeb\nMar\nApr\nMay\nJun\nJul\nAug'

Check this example from Learn Python the Hard Way.

How to insert double and float values to sqlite?

actually I think your code is just fine.. you can save those values as strings (TEXT) just like you did.. (if you want to)

and you probably get the error for the System.currentTimeMillis() that might be too big for INTEGER

Batch file to delete files older than N days

I think e.James's answer is good since it works with unmodified versions of Windows as early as Windows 2000 SP4 (and possibly earlier), but it required writing to an external file. Here is a modified version that does not create an external text file while maintaining the compatibility:

REM del_old.cmd
REM usage: del_old MM-DD-YYYY
setlocal enabledelayedexpansion
for /f "tokens=*" %%a IN ('xcopy *.* /d:%1 /L /I null') do @if exist "%%~nxa" set "excludefiles=!excludefiles!;;%%~nxa;;"
for /f "tokens=*" %%a IN ('dir /b') do @(@echo "%excludefiles%"|FINDSTR /C:";;%%a;;">nul || if exist "%%~nxa" DEL /F /Q "%%a">nul 2>&1)

To be true to the original question, here it is in a script that does ALL the math for you if you call it with the number of days as the parameter:

REM del_old_compute.cmd
REM usage: del_old_compute N
setlocal enabledelayedexpansion
set /a days=%1&set cur_y=%DATE:~10,4%&set cur_m=%DATE:~4,2%&set cur_d=%DATE:~7,2%
for /f "tokens=1 delims==" %%a in ('set cur_') do if "!%%a:~0,1!"=="0" set /a %%a=!%%a:~1,1!+0
set mo_2=28&set /a leapyear=cur_y*10/4
if %leapyear:~-1% equ 0 set mo_2=29
set mo_1=31&set mo_3=31&set mo_4=30&set mo_5=31
set mo_6=30&set mo_7=31&set mo_8=31&set mo_9=30
set mo_10=31&set mo_11=30&set mo_12=31
set /a past_y=(days/365)
set /a monthdays=days-((past_y*365)+((past_y/4)*1))&&set /a past_y=cur_y-past_y&set months=0
:setmonth
set /a minusmonth=(cur_m-1)-months
if %minusmonth% leq 0 set /a minusmonth+=12
set /a checkdays=(mo_%minusmonth%)
if %monthdays% geq %checkdays% set /a months+=1&set /a monthdays-=checkdays&goto :setmonth
set /a past_m=cur_m-months
set /a lastmonth=cur_m-1
if %lastmonth% leq 0 set /a lastmonth+=12
set /a lastmonth=mo_%lastmonth%
set /a past_d=cur_d-monthdays&set adddays=::
if %past_d% leq 0 (set /a past_m-=1&set adddays=)
if %past_m% leq 0 (set /a past_m+=12&set /a past_y-=1)
set mo_2=28&set /a leapyear=past_y*10/4
if %leapyear:~-1% equ 0 set mo_2=29
%adddays%set /a past_d+=mo_%past_m%
set d=%past_m%-%past_d%-%past_y%
for /f "tokens=*" %%a IN ('xcopy *.* /d:%d% /L /I null') do @if exist "%%~nxa" set "excludefiles=!excludefiles!;;%%~nxa;;"
for /f "tokens=*" %%a IN ('dir /b') do @(@echo "%excludefiles%"|FINDSTR /C:";;%%a;;">nul || if exist "%%~nxa" DEL /F /Q "%%a">nul 2>&1)

NOTE: The code above takes into account leap years, as well as the exact number of days in each month. The only maximum is the total number of days there have been since 0/0/0 (after that it returns negative years).

NOTE: The math only goes one way; it cannot correctly get future dates from negative input (it will try, but will likely go past the last day of the month).

java.time.format.DateTimeParseException: Text could not be parsed at index 21

Your original problem was wrong pattern symbol "h" which stands for the clock hour (range 1-12). In this case, the am-pm-information is missing. Better, use the pattern symbol "H" instead (hour of day in range 0-23). So the pattern should rather have been like:

uuuu-MM-dd'T'HH:mm:ss.SSSX (best pattern also suitable for strict mode)

The intel x86 emulator accelerator (HAXM installer) revision 6.0.5 is showing not compatible with windows

Try the following

  1. download HAXM from Intel https://software.intel.com/en-us/android/articles/intel-hardware-accelerated-execution-manager.

  2. Unzip the file and Run intelhaxm-android.exe.

  3. Run silent_install.bat.

In my computer Win10 x64 - VS2015 it worked

Is it possible to use argsort in descending order?

With your example:

avgDists = np.array([1, 8, 6, 9, 4])

Obtain indexes of n maximal values:

ids = np.argpartition(avgDists, -n)[-n:]

Sort them in descending order:

ids = ids[np.argsort(avgDists[ids])[::-1]]

Obtain results (for n=4):

>>> avgDists[ids]
array([9, 8, 6, 4])

PHP send mail to multiple email addresses

Programmatically sending an submitted form to multiple email address is a possible thing, however the best practice for this is by creating a mailing list. On the code the list address will be place and any change or update on email addresses to the recipients list can be done without changing in the code.

Catch error if iframe src fails to load . Error :-"Refused to display 'http://www.google.co.in/' in a frame.."

This is a slight modification to Edens answer - which for me in chrome didn't catch the error. Although you'll still get an error in the console: "Refused to display 'https://www.google.ca/' in a frame because it set 'X-Frame-Options' to 'sameorigin'." At least this will catch the error message and then you can deal with it.

 <iframe id="myframe" src="https://google.ca"></iframe>

 <script>
 myframe.onload = function(){
 var that = document.getElementById('myframe');

 try{
    (that.contentWindow||that.contentDocument).location.href;
 }
 catch(err){
    //err:SecurityError: Blocked a frame with origin "http://*********" from accessing a cross-origin frame.
    console.log('err:'+err);
}
}
</script>

How do you POST to a page using the PHP header() function?

In addition to what Salaryman said, take a look at the classes in PEAR, there are HTTP request classes there that you can use even if you do not have the cURL extension installed in your PHP distribution.

Visual Studio 2013 License Product Key

I solved this, without having to completely reinstall Visual Studio 2013.

For those who may come across this in the future, the following steps worked for me:

  1. Run the ISO (or vs_professional.exe).
  2. If you get the error below, you need to update the Windows Registry to trick the installer into thinking you still have the base version. If you don't get this error, skip to step 3 "The product version that you are trying to set up is earlier than the version already installed on this computer."

    • Click the link for 'examine the log file' and look near the bottom of the log, for this line: Detected related bundle ... operation: Downgrade

    • open regedit.exe and do an Edit > Find... for that GUID. In my case it was {6dff50d0-3bc3-4a92-b724-bf6d6a99de4f}. This was found in:

      HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall{6dff50d0-3bc3-4a92-b724-bf6d6a99de4f}

    • Edit the BundleVersion value and change it to a lower version. I changed mine from 12.0.21005.13 to 12.0.21000.13: BundleVersion for Visual Studio lower the version for BundleVersion

    • Exit the registry

  3. Run the ISO (or vs_professional.exe) again. If it has a repair button like the image below, you can skip to step 4.

    Visual Studio Repair button

    • Otherwise you have to let the installer fix the registry. I did this by "installing" at least one feature, even though I think I already had all features (they were not detected). This took about 20 minutes.
  4. Run the ISO (or vs_professional.exe) again. This time repair should be visible.

  5. Click Repair and let it update your installation and apply its embedded license key. This took about 20 minutes.


Now when you run Visual Studio 2013, it should indicate that a license key was applied, under Help > Register Product:

License: Product key applied

Hope this helps somebody in the future!

Reference blog 'story'

Deploying my application at the root in Tomcat

Adding to @Dima's answer, if you're using maven to build your package, you can tell it to set your WAR file name to ROOT in pom.xml:

<build>
    <finalName>ROOT</finalName>
</build>

By default, tomcat will deploy ROOT.war webapp into root context (/).

Question mark and colon in statement. What does it mean?

This is the conditional operator expression.

(condition) ? [true path] : [false path];

For example

 string value = someBooleanExpression ? "Alpha" : "Beta";

So if the boolean expression is true, value will hold "Alpha", otherwise, it holds "Beta".

For a common pitfall that people fall into, see this question in the C# tag wiki.

How to set min-height for bootstrap container

Two things are happening here.

  1. You are not using the container class properly.
  2. You are trying to override Bootstrap's CSS for the container class

Bootstrap uses a grid system and the .container class is defined in its own CSS. The grid has to exist within a container class DIV. The container DIV is just an indication to Bootstrap that the grid within has that parent. Therefore, you cannot set the height of a container.

What you want to do is the following:

<div class="container-fluid"> <!-- this is to make it responsive to your screen width -->
    <div class="row">
        <div class="col-md-4 myClassName">  <!-- myClassName is defined in my CSS as you defined your container -->
            <img src="#.jpg" height="200px" width="300px">
        </div>
    </div>
</div>

Here you can find more info on the Bootstrap grid system.

That being said, if you absolutely MUST override the Bootstrap CSS then I would try using the "!important" clause to my CSS definition as such...

.container {
   padding-right: 15px;
   padding-left: 15px;
   margin-right: auto;
   margin-left: auto;
   max-width: 900px;
   overflow:hidden;
   min-height:0px !important;
}

But I have always found that the "!important" clause just makes for messy CSS.

how to set start value as "0" in chartjs?

For Chart.js 2.*, the option for the scale to begin at zero is listed under the configuration options of the linear scale. This is used for numerical data, which should most probably be the case for your y-axis. So, you need to use this:

options: {
    scales: {
        yAxes: [{
            ticks: {
                beginAtZero: true
            }
        }]
    }
}

A sample line chart is also available here where the option is used for the y-axis. If your numerical data is on the x-axis, use xAxes instead of yAxes. Note that an array (and plural) is used for yAxes (or xAxes), because you may as well have multiple axes.

Using PUT method in HTML form

I wrote an npm package called 'html-form-enhancer'. By dropping it into your HTML source, it takes over submission of forms with methods aside from GET and POST, and also adds application/json serialization.

<script type=module" src="html-form-enhancer.js"></script>

<form method="PUT">
...
</form>

How do I import a Swift file from another Swift file?

I had the same problem, also in my XCTestCase files, but not in the regular project files.

To get rid of the:

Use of unresolved identifier 'PrimeNumberModel'

I needed to import the base module in the test file. In my case, my target is called 'myproject' and I added import myproject and the class was recognised.

Using curl POST with variables defined in bash script functions

We can assign a variable for curl using single quote ' and wrap some other variables in double-single-double quote "'" for substitution inside curl-variable. Then easily we can use that curl-variable which here is MERGE.

Example:

# other variables ... 
REF_NAME="new-branch";

# variable for curl using single quote => ' not double "
MERGE='{
    "repository": "tmp",
    "command": "git",
    "args": [
        "pull",
        "origin",
        "'"$REF_NAME"'"
    ],
    "options": {
        "cwd": "/home/git/tmp"
    }
}';

notice this line:

    "'"$REF_NAME"'"

and then calling curl as usual:

curl -s -X POST localhost:1365/M -H 'Content-Type: application/json' --data "$MERGE" 

jQuery keypress() event not firing?

With jQuery, I've done it this way:

function checkKey(e){
     switch (e.keyCode) {
        case 40:
            alert('down');
            break;
        case 38:
            alert('up');
            break;
        case 37:
            alert('left');
            break;
        case 39:
            alert('right');
            break;
        default:
            alert('???');  
            }      
}

if ($.browser.mozilla) {
    $(document).keypress (checkKey);
} else {
    $(document).keydown (checkKey);
}

Also, try these plugins, which looks like they do all that work for you:

http://www.openjs.com/scripts/events/keyboard_shortcuts

http://www.webappers.com/2008/07/31/bind-a-hot-key-combination-with-jquery-hotkeys/

Loop through an array php

You can use also this without creating additional variables nor copying the data in the memory like foreach() does.

while (false !== (list($item, $values) = each($array)))
{
    ...
}

Docker is installed but Docker Compose is not ? why?

You also need to install Docker Compose. See the manual. Here are the commands you need to execute

sudo curl -L "https://github.com/docker/compose/releases/download/1.26.0/docker-compose-$(uname -s)-$(uname -m)"  -o /usr/local/bin/docker-compose
sudo mv /usr/local/bin/docker-compose /usr/bin/docker-compose
sudo chmod +x /usr/bin/docker-compose

What is mapDispatchToProps?

mapStateToProps, mapDispatchToProps and connect from react-redux library provides a convenient way to access your state and dispatch function of your store. So basically connect is a higher order component, you can also think as a wrapper if this make sense for you. So every time your state is changed mapStateToProps will be called with your new state and subsequently as you props update component will run render function to render your component in browser. mapDispatchToProps also stores key-values on the props of your component, usually they take a form of a function. In such way you can trigger state change from your component onClick, onChange events.

From docs:

const TodoListComponent = ({ todos, onTodoClick }) => (
  <ul>
    {todos.map(todo =>
      <Todo
        key={todo.id}
        {...todo}
        onClick={() => onTodoClick(todo.id)}
      />
    )}
  </ul>
)

const mapStateToProps = (state) => {
  return {
    todos: getVisibleTodos(state.todos, state.visibilityFilter)
  }
}

const mapDispatchToProps = (dispatch) => {
  return {
    onTodoClick: (id) => {
      dispatch(toggleTodo(id))
    }
  }
}

function toggleTodo(index) {
  return { type: TOGGLE_TODO, index }
}

const TodoList = connect(
  mapStateToProps,
  mapDispatchToProps
)(TodoList) 

Also make sure that you are familiar with React stateless functions and Higher-Order Components

Is there a way to take a screenshot using Java and save it to some sort of image?

If you'd like to capture all monitors, you can use the following code:

GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice[] screens = ge.getScreenDevices();

Rectangle allScreenBounds = new Rectangle();
for (GraphicsDevice screen : screens) {
    Rectangle screenBounds = screen.getDefaultConfiguration().getBounds();

    allScreenBounds.width += screenBounds.width;
    allScreenBounds.height = Math.max(allScreenBounds.height, screenBounds.height);
}

Robot robot = new Robot();
BufferedImage screenShot = robot.createScreenCapture(allScreenBounds);

mkdir -p functionality in Python

I think Asa's answer is essentially correct, but you could extend it a little to act more like mkdir -p, either:

import os

def mkdir_path(path):
    if not os.access(path, os.F_OK):
        os.mkdirs(path)

or

import os
import errno

def mkdir_path(path):
    try:
        os.mkdirs(path)
    except os.error, e:
        if e.errno != errno.EEXIST:
            raise

These both handle the case where the path already exists silently but let other errors bubble up.

Has Facebook sharer.php changed to no longer accept detailed parameters?

Your problem is caused by the lack of markers OpenGraph, as you say it is not possible that you implement for some reason.

For you, the only solution is to use the PHP Facebook API.

  1. First you must create the application in your facebook account.
  2. When creating the application you will have two key data for your code:

    YOUR_APP_ID 
    YOUR_APP_SECRET
    
  3. Download the Facebook PHP SDK from here.

  4. You can start with this code for share content from your site:

    <?php
      // Remember to copy files from the SDK's src/ directory to a
      // directory in your application on the server, such as php-sdk/
      require_once('php-sdk/facebook.php');
    
      $config = array(
        'appId' => 'YOUR_APP_ID',
        'secret' => 'YOUR_APP_SECRET',
        'allowSignedRequest' => false // optional but should be set to false for non-canvas apps
      );
    
      $facebook = new Facebook($config);
      $user_id = $facebook->getUser();
    ?>
    <html>
      <head></head>
      <body>
    
      <?php
        if($user_id) {
    
          // We have a user ID, so probably a logged in user.
          // If not, we'll get an exception, which we handle below.
          try {
            $ret_obj = $facebook->api('/me/feed', 'POST',
                                        array(
                                          'link' => 'www.example.com',
                                          'message' => 'Posting with the PHP SDK!'
                                     ));
            echo '<pre>Post ID: ' . $ret_obj['id'] . '</pre>';
    
            // Give the user a logout link 
            echo '<br /><a href="' . $facebook->getLogoutUrl() . '">logout</a>';
          } catch(FacebookApiException $e) {
            // If the user is logged out, you can have a 
            // user ID even though the access token is invalid.
            // In this case, we'll get an exception, so we'll
            // just ask the user to login again here.
            $login_url = $facebook->getLoginUrl( array(
                           'scope' => 'publish_stream'
                           )); 
            echo 'Please <a href="' . $login_url . '">login.</a>';
            error_log($e->getType());
            error_log($e->getMessage());
          }   
        } else {
    
          // No user, so print a link for the user to login
          // To post to a user's wall, we need publish_stream permission
          // We'll use the current URL as the redirect_uri, so we don't
          // need to specify it here.
          $login_url = $facebook->getLoginUrl( array( 'scope' => 'publish_stream' ) );
          echo 'Please <a href="' . $login_url . '">login.</a>';
    
        } 
    
      ?>      
    
      </body> 
    </html>
    

You can find more examples in the Facebook Developers site:

https://developers.facebook.com/docs/reference/php

Check for column name in a SqlDataReader object

Hashtable ht = new Hashtable();
    Hashtable CreateColumnHash(SqlDataReader dr)
    {
        ht = new Hashtable();
        for (int i = 0; i < dr.FieldCount; i++)
        {
            ht.Add(dr.GetName(i), dr.GetName(i));
        }
        return ht;
    }

    bool ValidateColumn(string ColumnName)
    {
        return ht.Contains(ColumnName);
    }

vagrant login as root by default

Solution:
Add the following to your Vagrantfile:

config.ssh.username = 'root'
config.ssh.password = 'vagrant'
config.ssh.insert_key = 'true'

When you vagrant ssh henceforth, you will login as root and should expect the following:

==> mybox: Waiting for machine to boot. This may take a few minutes...
    mybox: SSH address: 127.0.0.1:2222
    mybox: SSH username: root
    mybox: SSH auth method: password
    mybox: Warning: Connection timeout. Retrying...
    mybox: Warning: Remote connection disconnect. Retrying...
==> mybox: Inserting Vagrant public key within guest...
==> mybox: Key inserted! Disconnecting and reconnecting using new SSH key...
==> mybox: Machine booted and ready!

Update 23-Jun-2015: This works for version 1.7.2 as well. Keying security has improved since 1.7.0; this technique overrides back to the previous method which uses a known private key. This solution is not intended to be used for a box that is accessible publicly without proper security measures done prior to publishing.

Reference:

How do I get rid of an element's offset using CSS?

You can apply a reset css to get rid of those 'defaults'. Here is an example of a reset css http://meyerweb.com/eric/tools/css/reset/ . Just apply the reset styles BEFORE your own styles.

Python creating a dictionary of lists

You can use defaultdict:

>>> from collections import defaultdict
>>> d = defaultdict(list)
>>> a = ['1', '2']
>>> for i in a:
...   for j in range(int(i), int(i) + 2):
...     d[j].append(i)
...
>>> d
defaultdict(<type 'list'>, {1: ['1'], 2: ['1', '2'], 3: ['2']})
>>> d.items()
[(1, ['1']), (2, ['1', '2']), (3, ['2'])]

How to implement onBackPressed() in Fragments?

According to the AndroidX release notes, androidx.activity 1.0.0-alpha01 is released and introduces ComponentActivity, a new base class of the existing FragmentActivity and AppCompatActivity. And this release brings us a new feature:

You can now register an OnBackPressedCallback via addOnBackPressedCallback to receive onBackPressed() callbacks without needing to override the method in your activity.

What is an example of the Liskov Substitution Principle?

LSP is necessary where some code thinks it is calling the methods of a type T, and may unknowingly call the methods of a type S, where S extends T (i.e. S inherits, derives from, or is a subtype of, the supertype T).

For example, this occurs where a function with an input parameter of type T, is called (i.e. invoked) with an argument value of type S. Or, where an identifier of type T, is assigned a value of type S.

val id : T = new S() // id thinks it's a T, but is a S

LSP requires the expectations (i.e. invariants) for methods of type T (e.g. Rectangle), not be violated when the methods of type S (e.g. Square) are called instead.

val rect : Rectangle = new Square(5) // thinks it's a Rectangle, but is a Square
val rect2 : Rectangle = rect.setWidth(10) // height is 10, LSP violation

Even a type with immutable fields still has invariants, e.g. the immutable Rectangle setters expect dimensions to be independently modified, but the immutable Square setters violate this expectation.

class Rectangle( val width : Int, val height : Int )
{
   def setWidth( w : Int ) = new Rectangle(w, height)
   def setHeight( h : Int ) = new Rectangle(width, h)
}

class Square( val side : Int ) extends Rectangle(side, side)
{
   override def setWidth( s : Int ) = new Square(s)
   override def setHeight( s : Int ) = new Square(s)
}

LSP requires that each method of the subtype S must have contravariant input parameter(s) and a covariant output.

Contravariant means the variance is contrary to the direction of the inheritance, i.e. the type Si, of each input parameter of each method of the subtype S, must be the same or a supertype of the type Ti of the corresponding input parameter of the corresponding method of the supertype T.

Covariance means the variance is in the same direction of the inheritance, i.e. the type So, of the output of each method of the subtype S, must be the same or a subtype of the type To of the corresponding output of the corresponding method of the supertype T.

This is because if the caller thinks it has a type T, thinks it is calling a method of T, then it supplies argument(s) of type Ti and assigns the output to the type To. When it is actually calling the corresponding method of S, then each Ti input argument is assigned to a Si input parameter, and the So output is assigned to the type To. Thus if Si were not contravariant w.r.t. to Ti, then a subtype Xi—which would not be a subtype of Si—could be assigned to Ti.

Additionally, for languages (e.g. Scala or Ceylon) which have definition-site variance annotations on type polymorphism parameters (i.e. generics), the co- or contra- direction of the variance annotation for each type parameter of the type T must be opposite or same direction respectively to every input parameter or output (of every method of T) that has the type of the type parameter.

Additionally, for each input parameter or output that has a function type, the variance direction required is reversed. This rule is applied recursively.


Subtyping is appropriate where the invariants can be enumerated.

There is much ongoing research on how to model invariants, so that they are enforced by the compiler.

Typestate (see page 3) declares and enforces state invariants orthogonal to type. Alternatively, invariants can be enforced by converting assertions to types. For example, to assert that a file is open before closing it, then File.open() could return an OpenFile type, which contains a close() method that is not available in File. A tic-tac-toe API can be another example of employing typing to enforce invariants at compile-time. The type system may even be Turing-complete, e.g. Scala. Dependently-typed languages and theorem provers formalize the models of higher-order typing.

Because of the need for semantics to abstract over extension, I expect that employing typing to model invariants, i.e. unified higher-order denotational semantics, is superior to the Typestate. ‘Extension’ means the unbounded, permuted composition of uncoordinated, modular development. Because it seems to me to be the antithesis of unification and thus degrees-of-freedom, to have two mutually-dependent models (e.g. types and Typestate) for expressing the shared semantics, which can't be unified with each other for extensible composition. For example, Expression Problem-like extension was unified in the subtyping, function overloading, and parametric typing domains.

My theoretical position is that for knowledge to exist (see section “Centralization is blind and unfit”), there will never be a general model that can enforce 100% coverage of all possible invariants in a Turing-complete computer language. For knowledge to exist, unexpected possibilities much exist, i.e. disorder and entropy must always be increasing. This is the entropic force. To prove all possible computations of a potential extension, is to compute a priori all possible extension.

This is why the Halting Theorem exists, i.e. it is undecidable whether every possible program in a Turing-complete programming language terminates. It can be proven that some specific program terminates (one which all possibilities have been defined and computed). But it is impossible to prove that all possible extension of that program terminates, unless the possibilities for extension of that program is not Turing complete (e.g. via dependent-typing). Since the fundamental requirement for Turing-completeness is unbounded recursion, it is intuitive to understand how Gödel's incompleteness theorems and Russell's paradox apply to extension.

An interpretation of these theorems incorporates them in a generalized conceptual understanding of the entropic force:

  • Gödel's incompleteness theorems: any formal theory, in which all arithmetic truths can be proved, is inconsistent.
  • Russell's paradox: every membership rule for a set that can contain a set, either enumerates the specific type of each member or contains itself. Thus sets either cannot be extended or they are unbounded recursion. For example, the set of everything that is not a teapot, includes itself, which includes itself, which includes itself, etc…. Thus a rule is inconsistent if it (may contain a set and) does not enumerate the specific types (i.e. allows all unspecified types) and does not allow unbounded extension. This is the set of sets that are not members of themselves. This inability to be both consistent and completely enumerated over all possible extension, is Gödel's incompleteness theorems.
  • Liskov Substition Principle: generally it is an undecidable problem whether any set is the subset of another, i.e. inheritance is generally undecidable.
  • Linsky Referencing: it is undecidable what the computation of something is, when it is described or perceived, i.e. perception (reality) has no absolute point of reference.
  • Coase's theorem: there is no external reference point, thus any barrier to unbounded external possibilities will fail.
  • Second law of thermodynamics: the entire universe (a closed system, i.e. everything) trends to maximum disorder, i.e. maximum independent possibilities.

How can I delete a newline if it is the last character in a file?

POSIX SED:

'${/^$/d}'

$ - match last line


{ COMMANDS } - A group of commands may be enclosed between { and } characters. This is particularly useful when you want a group of commands to be triggered by a single address (or address-range) match.

Evenly distributing n points on a sphere

OR... to place 20 points, compute the centers of the icosahedronal faces. For 12 points, find the vertices of the icosahedron. For 30 points, the mid point of the edges of the icosahedron. you can do the same thing with the tetrahedron, cube, dodecahedron and octahedrons: one set of points is on the vertices, another on the center of the face and another on the center of the edges. They cannot be mixed, however.

How do you convert a time.struct_time object into a datetime object?

Use time.mktime() to convert the time tuple (in localtime) into seconds since the Epoch, then use datetime.fromtimestamp() to get the datetime object.

from datetime import datetime
from time import mktime

dt = datetime.fromtimestamp(mktime(struct))

A fast way to delete all rows of a datatable at once

If you are running your code against a sqlserver database then
use this command

string sqlTrunc = "TRUNCATE TABLE " + yourTableName
SqlCommand cmd = new SqlCommand(sqlTrunc, conn);
cmd.ExecuteNonQuery();

this will be the fastest method and will delete everything from your table and reset the identity counter to zero.

The TRUNCATE keyword is supported also by other RDBMS.

5 years later:
Looking back at this answer I need to add something. The answer above is good only if you are absolutely sure about the source of the value in the yourTableName variable. This means that you shouldn't get this value from your user because he can type anything and this leads to Sql Injection problems well described in this famous comic strip. Always present your user a choice between hard coded names (tables or other symbolic values) using a non editable UI.

How can you float: right in React Native?

<View style={{ flex: 1, flexDirection: 'row', justifyContent: 'flex-end' }}>
  <Text>
  Some Text
  </Text>
</View>

flexDirection: If you want to move horizontally (row) or vertically (column)

justifyContent: the direction you want to move.

sed whole word search and replace

\b in regular expressions match word boundaries (i.e. the location between the first word character and non-word character):

$ echo "bar embarassment" | sed "s/\bbar\b/no bar/g"
no bar embarassment

How to use Session attributes in Spring-mvc

Isn't it easiest and shortest that way? I knew it and just tested it - working perfect here:

@GetMapping
public String hello(HttpSession session) {
    session.setAttribute("name","value");
    return "hello";
}

p.s. I came here searching for an answer of "How to use Session attributes in Spring-mvc", but read so many without seeing the most obvious that I had written in my code. I didn't see it, so I thought its wrong, but no it was not. So lets share that knowledge with the easiest solution for the main question.

How to get a date in YYYY-MM-DD format from a TSQL datetime field?

 IFormatProvider culture = new System.Globalization.CultureInfo("fr-FR", true);

cmdGetPaymentStatement.Parameters.AddWithValue("@pStartDate", DateTime.Parse("22/12/2017", culture, System.Globalization.DateTimeStyles.AssumeLocal)).IsNullable = true;

javascript multiple OR conditions in IF statement

With an OR (||) operation, if any one of the conditions are true, the result is true.

I think you want an AND (&&) operation here.

Changing the sign of a number in PHP?

re the edit: "Also i need a way to do the reverse If the float is a negative, make it a positive"

$number = -$number;

changes the number to its opposite.

Which method performs better: .Any() vs .Count() > 0?

The exact details differ a bit in .NET Framework vs .NET Core, but it also somewhat depends on what you're doing: if you're using an ICollection or ICollection<T> type (such as with List<T>) there is a .Count property that's cheap to access, whereas other types might require enumeration.

TL;DR:

Use .Count > 0 if the property exists, and otherwise .Any().

Using .Count() > 0 is never the best option, and in some cases could be dramatically slower.

This applies to both .NET Framework and .NET Core.


Now we can dive into the details..

Lists and Collections

Let's start with a very common case: using List<T> (which is also ICollection<T>).

The .Count property is implemented as:

    private int _size;

    public int Count {
        get {
            Contract.Ensures(Contract.Result<int>() >= 0);
            return _size; 
        }
    }

What this is saying is _size is maintained by Add(),Remove() etc, and since it's just accessing a field this is an extremely cheap operation -- we don't need to iterate over values.

ICollection and ICollection<T> both have .Count and most types that implement them are likely to do so in a similar way.

Other IEnumerables

Any other IEnumerable types that aren't also ICollection require starting enumeration to determine if they're empty or not. The key factor affecting performance is if we end up enumerating a single item (ideal) or the entire collection (relatively expensive).

If the collection is actually causing I/O such as by reading from a database or disk, this could be a big performance hit.


.NET Framework .Any()

In .NET Framework (4.8), the Any() implementation is:

public static bool Any<TSource>(this IEnumerable<TSource> source) {
    if (source == null) throw Error.ArgumentNull("source");
    using (IEnumerator<TSource> e = source.GetEnumerator()) {
        if (e.MoveNext()) return true;
    }
    return false;
}

This means no matter what, it's going to get a new enumerator object and try iterating once. This is more expensive than calling the List<T>.Count property, but at least it's not iterating the entire list.

.NET Framework .Count()

In .NET Framework (4.8), the Count() implementation is (basically):

public static int Count<TSource>(this IEnumerable<TSource> source)
{
    ICollection<TSource> collection = source as ICollection<TSource>;
    if (collection != null)
    { 
        return collection.Count;
    }
    int num = 0;
    using (IEnumerator<TSource> enumerator = source.GetEnumerator())
    {
        while (enumerator.MoveNext())
        {
            num = checked(num + 1);
        }
        return num;
    }
}

If available, ICollection.Count is used, but otherwise the collection is enumerated.


.NET Core .Any()

The LINQ Any() implementation in .NET Core is much smarter. You can see the complete source here but the relevant bits to this discussion:

    public static bool Any<TSource>(this IEnumerable<TSource> source)
    {
        //..snip..
        
        if (source is ICollection<TSource> collectionoft)
        {
            return collectionoft.Count != 0;
        }
        
        //..snip..

        using (IEnumerator<TSource> e = source.GetEnumerator())
        {
            return e.MoveNext();
        }
    }

Because a List<T> is an ICollection<T>, this will call the Count property (and though it calls another method, there's no extra allocations).

.NET Core .Count()

The .NET Core implementation (source) is basically the same as .NET Framework (see above), and so it will use ICollection.Count if available, and otherwise enumerates the collection.


Summary

.NET Framework

  • With ICollection:

    • .Count > 0 is best
    • .Count() > 0 is fine, but ultimately just calls ICollection.Count
    • .Any() is going to be slower, as it enumerates a single item
  • With non-ICollection (no .Count property)

    • .Any() is best, as it only enumerates a single item
    • .Count() > 0 is bad as it causes complete enumeration

.NET Core

  • .Count > 0 is best, if available (ICollection)
  • .Any() is fine, and will either do ICollection.Count > 0 or enumerate a single item
  • .Count() > 0 is bad as it causes complete enumeration

Windows 7 - Add Path

Another method that worked for me on Windows 7 that did not require administrative privileges:

Click on the Start menu, search for "environment," click "Edit environment variables for your account."

In the window that opens, select "PATH" under "User variables for username" and click the "Edit..." button. Add your new path to the end of the existing Path, separated by a semi-colon (%PATH%;C:\Python27;...;C:\NewPath). Click OK on all the windows, open a new CMD window, and test the new variable.

How can I use numpy.correlate to do autocorrelation?

Using Fourier transformation and the convolution theorem

The time complexicity is N*log(N)

def autocorr1(x):
    r2=np.fft.ifft(np.abs(np.fft.fft(x))**2).real
    return r2[:len(x)//2]

Here is a normalized and unbiased version, it is also N*log(N)

def autocorr2(x):
    r2=np.fft.ifft(np.abs(np.fft.fft(x))**2).real
    c=(r2/x.shape-np.mean(x)**2)/np.std(x)**2
    return c[:len(x)//2]

The method provided by A. Levy works, but I tested it in my PC, its time complexicity seems to be N*N

def autocorr(x):
    result = numpy.correlate(x, x, mode='full')
    return result[result.size/2:]

Elegant way to report missing values in a data.frame

If you want to do it for particular column, then you can also use this

length(which(is.na(airquality[1])==T))

How can I show line numbers in Eclipse?

Slight variation on Mac OSX:
Eclipse ? Preferences ? General ? Editors ? Text Editors ? Show line numbers

How can the size of an input text box be defined in HTML?

You can set the width in pixels via inline styling:

<input type="text" name="text" style="width: 195px;">

You can also set the width with a visible character length:

<input type="text" name="text" size="35">

Displaying a 3D model in JavaScript/HTML5

I also needed what you've been searching for and did some research.

I found JSC3D (https://code.google.com/p/jsc3d/). It's a project written entirely in Javascript and uses the HTML canvas. It has been tested for Opera, Chrome, Firefox, Safari, IE9 and more.

Then you have services as p3d.in and Sketchfab that give you a nice reader to view 3D models on a web page: they use HTML5 and WebGL. They both have a free version.

Keyboard shortcut to change font size in Eclipse?

Eclipse Neon (4.6)

Zoom In

Ctrl++

or

Ctrl+=

Zoom Out

Ctrl+-

This feature is described here:

In text editors, you can now use Zoom In (Ctrl++ or Ctrl+=) and Zoom Out (Ctrl+-) commands to increase and decrease the font size. Like a change in the General > Appearance > Colors and Fonts preference page, the commands persistently change the font size in all editors of the same type. If the editor type's font is configured to use a default font, then that default font will be zoomed.

So, the font size change is not limited to the current file and the new value of the font size is available here Window > Preferences > General > Appearance > Colors and Fonts.

How to use Visual Studio Code as Default Editor for Git

In the most recent release (v1.0, released in March 2016), you are now able to use VS Code as the default git commit/diff tool. Quoted from the documentations:

  1. Make sure you can run code --help from the command line and you get help.

    • if you do not see help, please follow these steps:

      • Mac: Select Shell Command: Install 'Code' command in path from the Command Palette.

        • Command Palette is what pops up when you press shift + ? + P while inside VS Code. (shift + ctrl + P in Windows)
      • Windows: Make sure you selected Add to PATH during the installation.
      • Linux: Make sure you installed Code via our new .deb or .rpm packages.
  2. From the command line, run git config --global core.editor "code --wait"

Now you can run git config --global -e and use VS Code as editor for configuring Git. enter image description here Add the following to enable support for using VS Code as diff tool:

[diff]
    tool = default-difftool
[difftool "default-difftool"]
    cmd = code --wait --diff $LOCAL $REMOTE

This leverages the new --diff option you can pass to VS Code to compare two files side by side.

To summarize, here are some examples of where you can use Git with VS Code:

  • git rebase HEAD~3 -i allows to interactive rebase using VS Code
  • git commit allows to use VS Code for the commit message
  • git add -p followed by e for interactive add
  • git difftool <commit>^ <commit> allows to use VS Code as diff editor for changes

PHP - Check if two arrays are equal

Short solution that works even with arrays which keys are given in different order:

public static function arrays_are_equal($array1, $array2)
{
    array_multisort($array1);
    array_multisort($array2);
    return ( serialize($array1) === serialize($array2) );
}

How to serve an image using nodejs

I like using Restify for REST services. In my case, I had created a REST service to serve up images and then if an image source returned 404/403, I wanted to return an alternative image. Here's what I came up with combining some of the stuff here:

function processRequest(req, res, next, url) {
    var httpOptions = {
        hostname: host,
        path: url,
        port: port,
        method: 'GET'
    };

    var reqGet = http.request(httpOptions, function (response) {
        var statusCode = response.statusCode;

        // Many images come back as 404/403 so check explicitly
        if (statusCode === 404 || statusCode === 403) {
            // Send default image if error
            var file = 'img/user.png';
            fs.stat(file, function (err, stat) {
                var img = fs.readFileSync(file);
                res.contentType = 'image/png';
                res.contentLength = stat.size;
                res.end(img, 'binary');
            });

        } else {
            var idx = 0;
            var len = parseInt(response.header("Content-Length"));
            var body = new Buffer(len);

            response.setEncoding('binary');

            response.on('data', function (chunk) {
                body.write(chunk, idx, "binary");
                idx += chunk.length;
            });

            response.on('end', function () {
                res.contentType = 'image/jpg';
                res.send(body);
            });

        }
    });

    reqGet.on('error', function (e) {
        // Send default image if error
        var file = 'img/user.png';
        fs.stat(file, function (err, stat) {
            var img = fs.readFileSync(file);
            res.contentType = 'image/png';
            res.contentLength = stat.size;
            res.end(img, 'binary');
        });
    });

    reqGet.end();

    return next();
}

How to fix a Div to top of page with CSS only

Yes, there are a number of ways that you can do this. The "fastest" way would be to add CSS to the div similar to the following

#term-defs {
height: 300px;
overflow: scroll; }

This will force the div to be scrollable, but this might not get the best effect. Another route would be to absolute fix the position of the items at the top, you can play with this by doing something like this.

#top {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 999;
  width: 100%;
  height: 23px;
}

This will fix it to the top, on top of other content with a height of 23px.

The final implementation will depend on what effect you really want.

How to use if-else option in JSTL

I got away with simply using two if tags, thought I'd add an answer in case it's of use to anyone else:

<c:if test="${condition}">
  ...
</c:if>
<c:if test="${!condition}">
  ...
</c:if>

whilst technically not an if-else per se, the behaviour is the same and avoids the clunky approach of using the choose tag, so depending on how complex your requirement is this might be preferable.

Open S3 object as a string with Boto3

I had a problem to read/parse the object from S3 because of .get() using Python 2.7 inside an AWS Lambda.

I added json to the example to show it became parsable :)

import boto3
import json

s3 = boto3.client('s3')

obj = s3.get_object(Bucket=bucket, Key=key)
j = json.loads(obj['Body'].read())

NOTE (for python 2.7): My object is all ascii, so I don't need .decode('utf-8')

NOTE (for python 3.6+): We moved to python 3.6 and discovered that read() now returns bytes so if you want to get a string out of it, you must use:

j = json.loads(obj['Body'].read().decode('utf-8'))

Cancel a UIView animation?

To cancel an animation you simply need to set the property that is currently being animated, outside of the UIView animation. That will stop the animation wherever it is, and the UIView will jump to the setting you just defined.

Git: how to reverse-merge a commit?

To revert a merge commit, you need to use: git revert -m <parent number>. So for example, to revert the recent most merge commit using the parent with number 1 you would use:

git revert -m 1 HEAD

To revert a merge commit before the last commit, you would do:

git revert -m 1 HEAD^

Use git show <merge commit SHA1> to see the parents, the numbering is the order they appear e.g. Merge: e4c54b3 4725ad2

git merge documentation: http://schacon.github.com/git/git-merge.html

git merge discussion (confusing but very detailed): http://schacon.github.com/git/howto/revert-a-faulty-merge.txt

error: package javax.servlet does not exist

The answer provided by @Matthias Herlitzius is mostly correct. Just for further clarity.

The servlet-api jar is best left up to the server to manage see here for detail

With that said, the dependency to add may vary according to your server/container. For example in Wildfly the dependency would be

<dependency>
    <groupId>org.jboss.spec.javax.servlet</groupId>
    <artifactId>jboss-servlet-api_3.1_spec</artifactId>
    <scope>provided</scope>
</dependency>

So becareful to check how your container has provided the servlet implementation.

Run an OLS regression with Pandas Data Frame

This would require me to reformat the data into lists inside lists, which seems to defeat the purpose of using pandas in the first place.

No it doesn't, just convert to a NumPy array:

>>> data = np.asarray(df)

This takes constant time because it just creates a view on your data. Then feed it to scikit-learn:

>>> from sklearn.linear_model import LinearRegression
>>> lr = LinearRegression()
>>> X, y = data[:, 1:], data[:, 0]
>>> lr.fit(X, y)
LinearRegression(copy_X=True, fit_intercept=True, normalize=False)
>>> lr.coef_
array([  4.01182386e-01,   3.51587361e-04])
>>> lr.intercept_
14.952479503953672

JavaScript: Create and save file

For latest browser, like Chrome, you can use the File API as in this tutorial:

window.requestFileSystem  = window.requestFileSystem || window.webkitRequestFileSystem;
window.requestFileSystem(window.PERSISTENT, 5*1024*1024 /*5MB*/, saveFile, errorHandler);

Why are exclamation marks used in Ruby methods?

Simple explanation:

foo = "BEST DAY EVER" #assign a string to variable foo.

=> foo.downcase #call method downcase, this is without any exclamation.

"best day ever"  #returns the result in downcase, but no change in value of foo.

=> foo #call the variable foo now.

"BEST DAY EVER" #variable is unchanged.

=> foo.downcase! #call destructive version.

=> foo #call the variable foo now.

"best day ever" #variable has been mutated in place.

But if you ever called a method downcase! in the explanation above, foo would change to downcase permanently. downcase! would not return a new string object but replace the string in place, totally changing the foo to downcase. I suggest you don't use downcase! unless it is totally necessary.

How to upload images into MySQL database using PHP code

Firstly, you should check if your image column is BLOB type!

I don't know anything about your SQL table, but if I'll try to make my own as an example.

We got fields id (int), image (blob) and image_name (varchar(64)).

So the code should look like this (assume ID is always '1' and let's use this mysql_query):

$image = addslashes(file_get_contents($_FILES['image']['tmp_name'])); //SQL Injection defence!
$image_name = addslashes($_FILES['image']['name']);
$sql = "INSERT INTO `product_images` (`id`, `image`, `image_name`) VALUES ('1', '{$image}', '{$image_name}')";
if (!mysql_query($sql)) { // Error handling
    echo "Something went wrong! :("; 
}

You are doing it wrong in many ways. Don't use mysql functions - they are deprecated! Use PDO or MySQLi. You should also think about storing files locations on disk. Using MySQL for storing images is thought to be Bad Idea™. Handling SQL table with big data like images can be problematic.

Also your HTML form is out of standards. It should look like this:

<form action="insert_product.php" method="POST" enctype="multipart/form-data">
    <label>File: </label><input type="file" name="image" />
    <input type="submit" />
</form>

Sidenote:

When dealing with files and storing them as a BLOB, the data must be escaped using mysql_real_escape_string(), otherwise it will result in a syntax error.

Which port we can use to run IIS other than 80?

Also remember, when running on alternate ports, you need to specify the port on the URL:

http://www.example.com:8080

There may be firewalls or proxy servers to consider depending on your environment.

What does "control reaches end of non-void function" mean?

add to your code:

"#include < stdlib.h>"

return EXIT_SUCCESS;

at the end of main()

Linux c++ error: undefined reference to 'dlopen'

I was using CMake to compile my project and I've found the same problem.

The solution described here works like a charm, simply add ${CMAKE_DL_LIBS} to the target_link_libraries() call

Changing text color of menu item in navigation drawer

Use app:itemIconTint in your NavigationView, ej:

<android.support.design.widget.NavigationView
    android:id="@+id/nav_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    app:itemTextColor="@color/customColor"
    app:itemIconTint="@color/customColor"
    android:fitsSystemWindows="true"
    app:headerLayout="@layout/nav_header_home"
    app:menu="@menu/activity_home_drawer" />

How to mount the android img file under linux?

Another option would be to use the File Explorer in DDMS (Eclipse SDK), you can see the whole file system there and download/upload files to the desired place. That way you don't have to mount and deal with images. Just remember to set your device as USB debuggable (from Developer Tools)

how to get program files x86 env variable?

On a 64-bit machine running in 64-bit mode:

  • echo %programfiles% ==> C:\Program Files
  • echo %programfiles(x86)% ==> C:\Program Files (x86)

On a 64-bit machine running in 32-bit (WOW64) mode:

  • echo %programfiles% ==> C:\Program Files (x86)
  • echo %programfiles(x86)% ==> C:\Program Files (x86)

On a 32-bit machine running in 32-bit mode:

  • echo %programfiles% ==> C:\Program Files
  • echo %programfiles(x86)% ==> %programfiles(x86)%

is there any PHP function for open page in new tab

You can simply use target="_blank" to open a page in a new tab

<a href="whatever.php" target="_blank">Opens On Another Tab</a>

Or you can simply use a javascript for onload

<body onload="window.open(url, '_blank');">

How to parse a string to an int in C++?

In C, you can use int atoi (const char * str),

Parses the C-string str interpreting its content as an integral number, which is returned as a value of type int.

How can I exclude $(this) from a jQuery selector?

You can also use the jQuery .siblings() method:

HTML

<div class="content">
  <a href="#">A</a>
  <a href="#">B</a>
  <a href="#">C</a>
</div>

Javascript

$(".content").on('click', 'a', function(e) {
  e.preventDefault();
  $(this).siblings().hide('slow');
});

Working demo: http://jsfiddle.net/wTm5f/

How to fire a button click event from JavaScript in ASP.NET

I used the below JavaScript code and it works...

var clickButton = document.getElementById("<%= btnClearSession.ClientID %>");
clickButton.click();

Get size of an Iterable in Java

I would go for it.next() for the simple reason that next() is guaranteed to be implemented, while remove() is an optional operation.

E next()

Returns the next element in the iteration.

void remove()

Removes from the underlying collection the last element returned by the iterator (optional operation).

phpMyAdmin is throwing a #2002 cannot log in to the mysql server phpmyadmin

I have also experienced the same thing, hopefully a this helps.

cd /etc/init.d
./mysql start

please login to access mysql and phpmyadmin

Importing two classes with same name. How to handle?

I just had the same problem, what I did, I arranged the library order in sequence, for example there were java.lang.NullPointerException and javacard.lang.NullPointerException. I made the first one as default library and if you needed to use the other you can explicitly specify the full qualified class name.

How can I convert a datetime object to milliseconds since epoch (unix time) in Python?

from datetime import datetime
from calendar import timegm

# Note: if you pass in a naive dttm object it's assumed to already be in UTC
def unix_time(dttm=None):
    if dttm is None:
       dttm = datetime.utcnow()

    return timegm(dttm.utctimetuple())

print "Unix time now: %d" % unix_time()
print "Unix timestamp from an existing dttm: %d" % unix_time(datetime(2014, 12, 30, 12, 0))

How to run SQL in shell script

Maybe it's too late for answering but, there's a working code:

sqlplus -s "/ as sysdba" << EOF
    SET HEADING OFF
    SET FEEDBACK OFF
    SET LINESIZE 3800
    SET TRIMSPOOL ON
    SET TERMOUT OFF
    SET SPACE 0
    SET PAGESIZE 0
    select (select instance_name from v\$instance) as DB_NAME,
           file_name
      from dba_data_files
     order by 2;

What are the differences between LinearLayout, RelativeLayout, and AbsoluteLayout?

Definitions:

  • Frame Layout: This is designed to block out an area on the screen to display a single item.
  • Linear Layout: A layout that arranges its children in a single column or a single row.
  • Relative Layout: This layout is a view group that displays child views in relative positions.
  • Table Layout: A layout that arranges its children into rows and columns.

More Information:

FrameLayout

FrameLayout is designed to block out an area on the screen to display a single item. Generally, FrameLayout should be used to hold a single child view, because it can be difficult to organize child views in a way that's scalable to different screen sizes without the children overlapping each other. You can, however, add multiple children to a FrameLayout and control their position within the FrameLayout by assigning gravity to each child, using the android:layout_gravity attribute.

Child views are drawn in a stack, with the most recently added child on top. The size of the FrameLayout is the size of its largest child (plus padding), visible or not (if the FrameLayout's parent permits).

RelativeLayout

A RelativeLayout is a very powerful utility for designing a user interface because it can eliminate nested view groups and keep your layout hierarchy flat, which improves performance. If you find yourself using several nested LinearLayout groups, you may be able to replace them with a single RelativeLayout.

(Current docs here)

TableLayout

A TableLayout consists of a number of TableRow objects, each defining a row (actually, you can have other children, which will be explained below). TableLayout containers do not display border lines for their rows, columns, or cells. Each row has zero or more cells; each cell can hold one View object. The table has as many columns as the row with the most cells. A table can leave cells empty. Cells can span columns, as they can in HTML.

The width of a column is defined by the row with the widest cell in that column.


Note: Absolute Layout is deprecated.

How do I convert a single character into it's hex ascii value in python

This might help

import binascii

x = b'test'
x = binascii.hexlify(x)
y = str(x,'ascii')

print(x) # Outputs b'74657374' (hex encoding of "test")
print(y) # Outputs 74657374

x_unhexed = binascii.unhexlify(x)
print(x_unhexed) # Outputs b'test'

x_ascii = str(x_unhexed,'ascii')
print(x_ascii) # Outputs test

This code contains examples for converting ASCII characters to and from hexadecimal. In your situation, the line you'd want to use is str(binascii.hexlify(c),'ascii').

Constructor overloading in Java - best practice

Constructor overloading is like method overloading. Constructors can be overloaded to create objects in different ways.

The compiler differentiates constructors based on how many arguments are present in the constructor and other parameters like the order in which the arguments are passed.

For further details about java constructor, please visit https://tecloger.com/constructor-in-java/

alternatives to REPLACE on a text or ntext datatype

Assuming SQL Server 2000, the following StackOverflow question should address your problem.

If using SQL Server 2005/2008, you can use the following code (taken from here):

select cast(replace(cast(myntext as nvarchar(max)),'find','replace') as ntext)
from myntexttable

Warning: "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"?

@aimme's answer should be accepted!

I would extend his answer with @david-baucum's comment because his explanation is clear!

I would also extend his answer that you can run multiple PHP versions at the same time using ppa:ondrej/php.

Then you don't need to change the PHP version simple call the composer like this: /usr/bin/php7.2 /usr/local/bin/composer install

Combining INSERT INTO and WITH/CTE

Yep:

WITH tab (
  bla bla
)

INSERT INTO dbo.prf_BatchItemAdditionalAPartyNos (  BatchID,                                                        AccountNo,
APartyNo,
SourceRowID)    

SELECT * FROM tab

Note that this is for SQL Server, which supports multiple CTEs:

WITH x AS (), y AS () INSERT INTO z (a, b, c) SELECT a, b, c FROM y

Teradata allows only one CTE and the syntax is as your example.

Using number as "index" (JSON)

JSON only allows key names to be strings. Those strings can consist of numerical values.

You aren't using JSON though. You have a JavaScript object literal. You can use identifiers for keys, but an identifier can't start with a number. You can still use strings though.

var Game={
    "status": [
        {
            "0": "val",
            "1": "val",
            "2": "val"
        },
        {
            "0": "val",
            "1": "val",
            "2": "val"
        }
    ]
}

If you access the properties with dot-notation, then you have to use identifiers. Use square bracket notation instead: Game.status[0][0].

But given that data, an array would seem to make more sense.

var Game={
    "status": [
        [
            "val",
            "val",
            "val"
        ],
        [
            "val",
            "val",
            "val"
        ]
    ]
}

How to re-render flatlist?

Just use:

onRefresh={true}

inside your flatList component.

Kotlin's List missing "add", "remove", Map missing "put", etc?

Unlike many languages, Kotlin distinguishes between mutable and immutable collections (lists, sets, maps, etc). Precise control over exactly when collections can be edited is useful for eliminating bugs, and for designing good APIs.

https://kotlinlang.org/docs/reference/collections.html

You'll need to use a MutableList list.

class TempClass {
    var myList: MutableList<Int> = mutableListOf<Int>()
    fun doSomething() {
        // myList = ArrayList<Int>() // initializer is redundant
        myList.add(10)
        myList.remove(10)
    }
}

MutableList<Int> = arrayListOf() should also work.

Shortest way to print current year in a website

It's not a good practice to use document.write. You can learn more about document.write by pressing here. Don't use document.write unless if you have to. Here's a somewhat friendly javascript/html solution. And yes, there is studies on how InnerHTML is bad, working on a more friendly soultion.

document.getElementById("year").innerHTML=(new Date).getFullYear();

? javascript

? html

<span id="year"></span>

You can place the javascript code in your html, but it would look best in a javascript file. Very clean answer. Personally, I recommend writing the current year with PHP. Probably the safest answer.

If you want to write the current year with PHP, you can do so with this small code.

<?php echo date("Y"); ?>

Remember in order to apply this PHP code, your webpage file has to be PHP.

Instantiating a generic class in Java

And this is the Factory implementation, as Jon Skeet suggested:

interface Factory<T> {
    T factory();
}

class Araba {
    //static inner class for Factory<T> implementation
    public static class ArabaFactory implements Factory<Araba> {
        public Araba factory() {
            return new Araba();
        }
    }
    public String toString() { return "Abubeee"; }
}

class Generic<T> {
    private T var;

    Generic(Factory<T> fact) {
        System.out.println("Constructor with Factory<T> parameter");
        var = fact.factory();
    }
    Generic(T var) {
        System.out.println("Constructor with T parameter");
        this.var = var;
    }
    T get() { return var; }
}

public class Main {
    public static void main(String[] string) {
        Generic<Araba> gen = new Generic<Araba>(new Araba.ArabaFactory());
        System.out.print(gen.get());
    }
}

Output:

Constructor with Factory<T> parameter
Abubeee

Could not load file or assembly '' or one of its dependencies

I kept getting this error on my web forms project in visual studio 2015. I shutdown Visual Studio and I killed the ScriptedSandbox64.exe, Microsoft.VsHub.Server.HttpHostx64.exe, Microsoft.VsHub.Server.HttpHostx.exe *32, Microsoft.VisualStudio.Web.Host.exe *32 processes and it seemed to help fix the issue.

How to format a numeric column as phone number in SQL

If you want to just format the output no need to create a new table or a function. In this scenario the area code was on a separate fields. I use field1, field2 just to illustrate you can select other fields in the same query:

area  phone
213   8962102

Select statement:

Select field1, field2,areacode,phone,SUBSTR(tablename.areacode,1,3) + '-' + SUBSTR(tablename.phone,1,3) + '-' + SUBSTR(tablename.areacode,4,4) as Formatted Phone from tablename

Sample OUTPUT:

columns: FIELD1, FIELD2, AREA, PHONE, FORMATTED PHONE
data:    Field1, Field2, 213,  8962102,  213-896-2102

Where are static variables stored in C and C++?

How to find it yourself with objdump -Sr

To actually understand what is going on, you must understand linker relocation. If you've never touched that, consider reading this post first.

Let's analyze a Linux x86-64 ELF example to see it ourselves:

#include <stdio.h>

int f() {
    static int i = 1;
    i++;
    return i;
}

int main() {
    printf("%d\n", f());
    printf("%d\n", f());
    return 0;
}

Compile with:

gcc -ggdb -c main.c

Decompile the code with:

objdump -Sr main.o
  • -S decompiles the code with the original source intermingled
  • -r shows relocation information

Inside the decompilation of f we see:

 static int i = 1;
 i++;
4:  8b 05 00 00 00 00       mov    0x0(%rip),%eax        # a <f+0xa>
        6: R_X86_64_PC32    .data-0x4

and the .data-0x4 says that it will go to the first byte of the .data segment.

The -0x4 is there because we are using RIP relative addressing, thus the %rip in the instruction and R_X86_64_PC32.

It is required because RIP points to the following instruction, which starts 4 bytes after 00 00 00 00 which is what will get relocated. I have explained this in more detail at: https://stackoverflow.com/a/30515926/895245

Then, if we modify the source to i = 1 and do the same analysis, we conclude that:

  • static int i = 0 goes on .bss
  • static int i = 1 goes on .data

How can I combine flexbox and vertical scroll in a full-height app?

Thanks to https://stackoverflow.com/users/1652962/cimmanon that gave me the answer.

The solution is setting a height to the vertical scrollable element. For example:

#container article {
    flex: 1 1 auto;
    overflow-y: auto;
    height: 0px;
}

The element will have height because flexbox recalculates it unless you want a min-height so you can use height: 100px; that it is exactly the same as: min-height: 100px;

#container article {
    flex: 1 1 auto;
    overflow-y: auto;
    height: 100px; /* == min-height: 100px*/
}

So the best solution if you want a min-height in the vertical scroll:

#container article {
    flex: 1 1 auto;
    overflow-y: auto;
    min-height: 100px;
}

If you just want full vertical scroll in case there is no enough space to see the article:

#container article {
    flex: 1 1 auto;
    overflow-y: auto;
    min-height: 0px;
}

The final code: http://jsfiddle.net/ch7n6/867/

JavaScript onclick redirect

Remove 'javascript:' from your code and it should work.

Do you happen to use FireFox? I have learned from someone else that FireFox no longer accepts the 'javascript:' string. However, for the life of me, I cannot find the original source (though I believe it was somewhere in FF update notes).

What's the fastest algorithm for sorting a linked list?

As I know, the best sorting algorithm is O(n*log n), whatever the container - it's been proved that sorting in the broad sense of the word (mergesort/quicksort etc style) can't go lower. Using a linked list will not give you a better run time.

The only one algorithm which runs in O(n) is a "hack" algorithm which relies on counting values rather than actually sorting.

Can I hide/show asp:Menu items based on role?

I prefer to use the FindItem method and use the value path for locating the item. Make sure your PathSeparator property on the menu matches what you're using in FindItem parameter.

    protected void Page_Load(object sender, EventArgs e)
    {

        // remove manage user accounts menu item for non-admin users.
        if (!Page.User.IsInRole("Admin"))
        {
            MenuItem item = NavigationMenu.FindItem("Users/Manage Accounts");
            item.Parent.ChildItems.Remove(item);  
        }

    }

How do I auto-submit an upload form when a file is selected?

<form action="http://example.com">
    <input type="file" onchange="Submit()" />
</form>

 <script>
     // it will submit form 0 or you have to select particular form
     document.getElementsByTagName("form")[0].submit();       
 </script>

How can I find a file/directory that could be anywhere on linux command line?

If need to find nested in some dirs:

find / -type f -wholename "*dirname/filename"

Or connected dirs:

find / -type d -wholename "*foo/bar"

Postgresql - change the size of a varchar column to lower length

Here's the cache of the page described by Greg Smith. In case that dies as well, the alter statement looks like this:

UPDATE pg_attribute SET atttypmod = 35+4
WHERE attrelid = 'TABLE1'::regclass
AND attname = 'COL1';

Where your table is TABLE1, the column is COL1 and you want to set it to 35 characters (the +4 is needed for legacy purposes according to the link, possibly the overhead referred to by A.H. in the comments).

How to open a new form from another form

ok so I used this:

public partial class Form1 : Form
{
    private void Button_Click(object sender, EventArgs e)
    {
        Form2 myForm = new Form2();
        this.Hide();
        myForm.ShowDialog();
        this.Close();
    }
}

This seems to be working fine but the first form is just hidden and it can still generate events. the "this.Close()" is needed to close the first form but if you still want your form to run (and not act like a launcher) you MUST replace it with

this.Show();

Best of luck!

When using Spring Security, what is the proper way to obtain current username (i.e. SecurityContext) information in a bean?

The best solution if you are using Spring 3 and need the authenticated principal in your controller is to do something like this:

import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.userdetails.User;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;

    @Controller
    public class KnoteController {
        @RequestMapping(method = RequestMethod.GET)
        public java.lang.String list(Model uiModel, UsernamePasswordAuthenticationToken authToken) {

            if (authToken instanceof UsernamePasswordAuthenticationToken) {
                user = (User) authToken.getPrincipal();
            }
            ...

    }

How to watch for array changes?

Not sure if this covers absolutely everything, but I use something like this (especially when debugging) to detect when an array has an element added:

var array = [1,2,3,4];
array = new Proxy(array, {
    set: function(target, key, value) {
        if (Number.isInteger(Number(key)) || key === 'length') {
            debugger; //or other code
        }
        target[key] = value;
        return true;
    }
});

What's the right way to decode a string that has special HTML entities in it?

Don’t use the DOM to do this. Using the DOM to decode HTML entities (as suggested in the currently accepted answer) leads to differences in cross-browser results.

For a robust & deterministic solution that decodes character references according to the algorithm in the HTML Standard, use the he library. From its README:

he (for “HTML entities”) is a robust HTML entity encoder/decoder written in JavaScript. It supports all standardized named character references as per HTML, handles ambiguous ampersands and other edge cases just like a browser would, has an extensive test suite, and — contrary to many other JavaScript solutions — he handles astral Unicode symbols just fine. An online demo is available.

Here’s how you’d use it:

he.decode("We&#39;re unable to complete your request at this time.");
? "We're unable to complete your request at this time."

Disclaimer: I'm the author of the he library.

See this Stack Overflow answer for some more info.

Creating all possible k combinations of n items in C++

Behind the link below is a generic C# answer to this problem: How to format all combinations out of a list of objects. You can limit the results only to the length of k pretty easily.

https://stackoverflow.com/a/40417765/2613458

How do I print colored output with Python 3?

Since Python is interpreted and run in C, it is possible to set colors without a module.

You can define a class for colors like this:

class color:
   PURPLE = '\033[1;35;48m'
   CYAN = '\033[1;36;48m'
   BOLD = '\033[1;37;48m'
   BLUE = '\033[1;34;48m'
   GREEN = '\033[1;32;48m'
   YELLOW = '\033[1;33;48m'
   RED = '\033[1;31;48m'
   BLACK = '\033[1;30;48m'
   UNDERLINE = '\033[4;37;48m'
   END = '\033[1;37;0m'

When writing code, you can simply write:

print(color.BLUE + "hello friends" + color.END)

Note that the color you choose will have to be capitalized like your class definition, and that these are color choices that I personally find satisfying. For a fuller array of color choices and, indeed, background choices as well, please see: https://gist.github.com/RabaDabaDoba/145049536f815903c79944599c6f952a.

This is code for C, but can easily be adapted to Python once you realize how the code is written.

Take BLUE for example, since that is what you are wanting to display.

BLUE = '033[1;37;48m'

\033 tells Python to break and pay attention to the following formatting.

1 informs the code to be bold. (I prefer 1 to 0 because it pops more.)

34 is the actual color code. It chooses blue.

48m is the background color. 48m is the same shade as the console window, so it seems there is no background.

c++ compile error: ISO C++ forbids comparison between pointer and integer

You must remember to use single quotes for char constants. So use

if (answer == 'y') return true;

Rather than

if (answer == "y") return true;

I tested this and it works

Print all properties of a Python Class

In this simple case you can use vars():

an = Animal()
attrs = vars(an)
# {'kids': 0, 'name': 'Dog', 'color': 'Spotted', 'age': 10, 'legs': 2, 'smell': 'Alot'}
# now dump this in some way or another
print(', '.join("%s: %s" % item for item in attrs.items()))

If you want to store Python objects on the disk you should look at shelve — Python object persistence.

Convert A String (like testing123) To Binary In Java

The usual way is to use String#getBytes() to get the underlying bytes and then present those bytes in some other form (hex, binary whatever).

Note that getBytes() uses the default charset, so if you want the string converted to some specific character encoding, you should use getBytes(String encoding) instead, but many times (esp when dealing with ASCII) getBytes() is enough (and has the advantage of not throwing a checked exception).

For specific conversion to binary, here is an example:

  String s = "foo";
  byte[] bytes = s.getBytes();
  StringBuilder binary = new StringBuilder();
  for (byte b : bytes)
  {
     int val = b;
     for (int i = 0; i < 8; i++)
     {
        binary.append((val & 128) == 0 ? 0 : 1);
        val <<= 1;
     }
     binary.append(' ');
  }
  System.out.println("'" + s + "' to binary: " + binary);

Running this example will yield:

'foo' to binary: 01100110 01101111 01101111 

spacing between form fields

In your CSS file:

input { margin-bottom: 10px; }

Reordering Chart Data Series

This function gets the series names, puts them into an array, sorts the array and based on that defines the plotting order which will give the desired output.

Function Increasing_Legend_Sort(mychart As Chart)


    Dim Arr()
    ReDim Arr(1 To mychart.FullSeriesCollection.Count)

        'Assigning Series names to an array
        For i = LBound(Arr) To UBound(Arr)
        Arr(i) = mychart.FullSeriesCollection(i).Name
        Next i

        'Bubble-Sort (Sort the array in increasing order)
        For r1 = LBound(Arr) To UBound(Arr)
            rval = Arr(r1)
                For r2 = LBound(Arr) To UBound(Arr)
                    If Arr(r2) > rval Then 'Change ">" to "<" to make it decreasing
                        Arr(r1) = Arr(r2)
                        Arr(r2) = rval
                        rval = Arr(r1)
                    End If
                Next r2
        Next r1

    'Defining the PlotOrder
    For i = LBound(Arr) To UBound(Arr)
    mychart.FullSeriesCollection(Arr(i)).PlotOrder = i
    Next i

End Function

How do I resize a Google Map with JavaScript after it has loaded?

This is best it will do the Job done. It will re-size your Map. No need to inspect element anymore to re-size your Map. What it does it will automatically trigger re-size event .

    google.maps.event.addListener(map, "idle", function()
        {
            google.maps.event.trigger(map, 'resize');
        });

        map_array[Next].setZoom( map.getZoom() - 1 );
    map_array[Next].setZoom( map.getZoom() + 1 );

Fixed positioning in Mobile Safari

<meta name="viewport" content="width=320, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no"/> 

Also making sure height=device-height is not present in this meta tag helps prevent additional footer padding that normally would not exist on the page. The menubar height adds to the viewport height causing a fixed background to become scrollable.

"ssl module in Python is not available" when installing package with pip3

Step by step guide to install Python 3.6 and pip3 in Ubuntu

  1. Install the necessary packages for Python and ssl: $ sudo apt-get install libreadline-gplv2-dev libncursesw5-dev libssl-dev libsqlite3-dev tk-dev libgdbm-dev libc6-dev libbz2-dev

  2. Download and unzip "Python-3.6.8.tar.xz" from https://www.python.org/ftp/python/ into your home directory.

  3. Open terminal in that directory and run: $ ./configure

  4. Build and install: $ make && sudo make install

  5. Install packages with: $ pip3 install package_name

Disclaimer: The above commands are not tested in Ubuntu 20.04 LTS.

jQuery get mouse position within an element

This solution supports all major browsers including IE. It also takes care of scrolling. First, it retrieves the position of the element relative to the page efficiently, and without using a recursive function. Then it gets the x and y of the mouse click relative to the page and does the subtraction to get the answer which is the position relative to the element (the element can be an image or div for example):

function getXY(evt) {
    var element = document.getElementById('elementId');  //replace elementId with your element's Id.
    var rect = element.getBoundingClientRect();
    var scrollTop = document.documentElement.scrollTop?
                    document.documentElement.scrollTop:document.body.scrollTop;
    var scrollLeft = document.documentElement.scrollLeft?                   
                    document.documentElement.scrollLeft:document.body.scrollLeft;
    var elementLeft = rect.left+scrollLeft;  
    var elementTop = rect.top+scrollTop;

        if (document.all){ //detects using IE   
            x = event.clientX+scrollLeft-elementLeft; //event not evt because of IE
            y = event.clientY+scrollTop-elementTop;
        }
        else{
            x = evt.pageX-elementLeft;
            y = evt.pageY-elementTop;
    }

Can "git pull --all" update all my local branches?

As of git 2.9:

git pull --rebase --autostash

See https://git-scm.com/docs/git-rebase

Automatically create a temporary stash before the operation begins, and apply it after the operation ends. This means that you can run rebase on a dirty worktree. However, use with care: the final stash application after a successful rebase might result in non-trivial conflicts.

callback to handle completion of pipe

I found an a bit different solution of my problem regarding this context. Thought worth sharing.

Most of the example create readStreams from file. But in my case readStream has to be created from JSON string coming from a message pool.

var jsonStream = through2.obj(function(chunk, encoding, callback) {
                    this.push(JSON.stringify(chunk, null, 4) + '\n');
                    callback();
                });
// message.value --> value/text to write in write.txt 
jsonStream.write(JSON.parse(message.value));
var writeStream = sftp.createWriteStream("/path/to/write/write.txt");

//"close" event didn't work for me!
writeStream.on( 'close', function () {
    console.log( "- done!" );
    sftp.end();
    }
);

//"finish" event didn't work for me either!
writeStream.on( 'close', function () {
    console.log( "- done!"
        sftp.end();
        }
);

// finally this worked for me!
jsonStream.on('data', function(data) {
    var toString = Object.prototype.toString.call(data);
    console.log('type of data:', toString);
    console.log( "- file transferred" );
});

jsonStream.pipe( writeStream );

what do these symbolic strings mean: %02d %01d?

They are formatting String. The Java specific syntax is given in java.util.Formatter.

The general syntax is as follows:

   %[argument_index$][flags][width][.precision]conversion

%02d performs decimal integer conversion d, formatted with zero padding (0 flag), with width 2. Thus, an int argument whose value is say 7, will be formatted into "07" as a String.

You may also see this formatting string in e.g. String.format.


Commonly used formats

These are just some commonly used formats and doesn't cover the syntax exhaustively.

Zero padding for numbers

System.out.printf("Agent %03d to the rescue!", 7);
// Agent 007 to the rescue!

Width for justification

You can use the - flag for left justification; otherwise it'll be right justification.

for (Map.Entry<Object,Object> prop : System.getProperties().entrySet()) {
    System.out.printf("%-30s : %50s%n", prop.getKey(), prop.getValue());
}

This prints something like:

java.version                   :                                 1.6.0_07
java.vm.name                   :               Java HotSpot(TM) Client VM
java.vm.vendor                 :                    Sun Microsystems Inc.
java.vm.specification.name     :       Java Virtual Machine Specification
java.runtime.name              :          Java(TM) SE Runtime Environment
java.vendor.url                :                     http://java.sun.com/

For more powerful message formatting, you can use java.text.MessageFormat. %n is the newline conversion (see below).

Hexadecimal conversion

System.out.println(Integer.toHexString(255));
// ff

System.out.printf("%d is %<08X", 255);
// 255 is 000000FF

Note that this also uses the < relative indexing (see below).

Floating point formatting

System.out.printf("%+,010.2f%n", 1234.567);
System.out.printf("%+,010.2f%n", -66.6666);
// +01,234.57
// -000066.67

For more powerful floating point formatting, use DecimalFormat instead.

%n for platform-specific line separator

System.out.printf("%s,%n%s%n", "Hello", "World");
// Hello,
// World

%% for an actual %-sign

System.out.printf("It's %s%% guaranteed!", 99.99);
// It's 99.99% guaranteed!

Note that the double literal 99.99 is autoboxed to Double, on which a string conversion using toString() is defined.

n$ for explicit argument indexing

System.out.printf("%1$s! %1$s %2$s! %1$s %2$s %3$s!",
    "Du", "hast", "mich"
);
// Du! Du hast! Du hast mich!

< for relative indexing

System.out.format("%s?! %<S?!?!?", "Who's your daddy");
// Who's your daddy?! WHO'S YOUR DADDY?!?!?

Related questions

Find Facebook user (url to profile page) by known email address

Maybe things changed, but I recall rapleaf had a service where you enter an email address and you could receive a facebook id.
https://www.rapleaf.com/

If something was not in there, one could "sign up" with the email, and it should have a chance to get the data after a while.

I came across this when using a search tool called Maltego a few years back.
The app uses many types of "transforms", and a few where related to facebook and twitter etc..

..or find some new sqli's on fb and fb apps, hehe. :)

How can I run Tensorboard on a remote server?

This is not a proper answer but a troubleshooter, hopefully helps other less seasoned networkers like me.

In my case (firefox+ubuntu16) the browser was connecting, but showing a blank page (with the tensorboard logo on the tab), and no log activity at all was shown. I still don't know what could be the reason for that (didn't look much into it but if anybody knows please let know!), but I solved it switching to ubuntu's default browser. Here the exact steps, pretty much the same as in @Olivier Moindrot's answer:

  1. On the server, start tensorboard: tensorboard --logdir=. --host=localhost --port=6006
  2. On the client, open the ssh tunnel ssh -p 23 <USER>@<SERVER> -N -f -L localhost:16006:localhost:6006
  3. Open ubuntu's Browser and visit localhost:16006. The tensorboard page should load without much delay.

To check that the SSH tunnel is effectively working, a simple echo server like this python script can help:

  1. Put the script into an <ECHO>.py file in the server and run it with python <ECHO>.py. Now the server will have the echo script listening on 0.0.0.0:5555.
  2. On the client, open the ssh tunnel ssh -p <SSH_PORT> <USER>@<SERVER> -N -f -L localhost:12345:localhost:5555
  3. On the client, in the same terminal used to open the tunnel (step 2.), issuing telnet localhost 12345 will connect to the echo script running in the server. Typing hello and pressing enter should print hello back. If that is the case, your SSH tunnel is working. This was my case, and lead me to the conclusion that the problem involved the browser. Trying to connect from a different terminal caused the terminal to freeze.

As I said, hope it helps!
Cheers,
Andres

jQuery vs. javascript?

Jquery VS javascript, I am completely against the OP in this question. Comparison happens with two similar things, not in such case.

Jquery is Javascript. A javascript library to reduce vague coding, collection commonly used javascript functions which has proven to help in efficient and fast coding.

Javascript is the source, the actual scripts that browser responds to.

Detect if value is number in MySQL

SELECT * FROM myTable
WHERE col1 REGEXP '^[+-]?[0-9]*([0-9]\\.|[0-9]|\\.[0-9])[0-9]*(e[+-]?[0-9]+)?$'

Will also match signed decimals (like -1.2, +0.2, 6., 2e9, 1.2e-10).

Test:

drop table if exists myTable;
create table myTable (col1 varchar(50));
insert into myTable (col1) 
  values ('00.00'),('+1'),('.123'),('-.23e4'),('12.e-5'),('3.5e+6'),('a'),('e6'),('+e0');

select 
  col1,
  col1 + 0 as casted,
  col1 REGEXP '^[+-]?[0-9]*([0-9]\\.|[0-9]|\\.[0-9])[0-9]*(e[+-]?[0-9]+)?$' as isNumeric
from myTable;

Result:

col1   |  casted | isNumeric
-------|---------|----------
00.00  |       0 |         1
+1     |       1 |         1
.123   |   0.123 |         1
-.23e4 |   -2300 |         1
12.e-5 | 0.00012 |         1
3.5e+6 | 3500000 |         1
a      |       0 |         0
e6     |       0 |         0
+e0    |       0 |         0

Demo

input type="submit" Vs button tag are they interchangeable?

If you are talking about <input type=button>, it won't automatically submit the form

if you are talking about the <button> tag, that's newer and doesn't automatically submit in all browsers.

Bottom line, if you want the form to submit on click in all browsers, use <input type="submit">

How to model type-safe enum types?

just discovered enumeratum. it's pretty amazing and equally amazing it's not more well known!

In CSS how do you change font size of h1 and h2

What have you tried? This should work.

h1 { font-size: 20pt; }
h2 { font-size: 16pt; }

How to filter an array of objects based on values in an inner array with jq?

Here is another solution which uses any/2

map(select(any(.Names[]; contains("data"))|not)|.Id)[]

with the sample data and the -r option it produces

cb94e7a42732b598ad18a8f27454a886c1aa8bbba6167646d8f064cd86191e2b
a4b7e6f5752d8dcb906a5901f7ab82e403b9dff4eaaeebea767a04bac4aada19

Getting the docstring from a function

Interactively, you can display it with

help(my_func)

Or from code you can retrieve it with

my_func.__doc__

Detect click outside element

You can register two event listeners for click event like this

document.getElementById("some-area")
        .addEventListener("click", function(e){
        alert("You clicked on the area!");
        e.stopPropagation();// this will stop propagation of this event to upper level
     }
);

document.body.addEventListener("click", 
   function(e) {
           alert("You clicked outside the area!");
         }
);

How to make a deep copy of Java ArrayList

Cloning the objects before adding them. For example, instead of newList.addAll(oldList);

for(Person p : oldList) {
    newList.add(p.clone());
}

Assuming clone is correctly overriden inPerson.

What is code coverage and how do YOU measure it?

For Perl there's the excellent Devel::Cover module which I regularly use on my modules.

If the build and installation is managed by Module::Build you can simply run ./Build testcover to get a nice HTML site that tells you the coverage per sub, line and condition, with nice colors making it easy to see which code path has not been covered.

How to plot ROC curve in Python

The previous answers assume that you indeed calculated TP/Sens yourself. It's a bad idea to do this manually, it's easy to make mistakes with the calculations, rather use a library function for all of this.

the plot_roc function in scikit_lean does exactly what you need: http://scikit-learn.org/stable/auto_examples/model_selection/plot_roc.html

The essential part of the code is:

  for i in range(n_classes):
      fpr[i], tpr[i], _ = roc_curve(y_test[:, i], y_score[:, i])
      roc_auc[i] = auc(fpr[i], tpr[i])

Checking if a variable is an integer

Probably you are looking for something like this:

Accept "2.0 or 2.0 as an INT but reject 2.1 and "2.1"

num = 2.0

if num.is_a? String num = Float(num) rescue false end

new_num = Integer(num) rescue false

puts num

puts new_num

puts num == new_num

php how to go one level up on dirname(__FILE__)

One level up, I have used:

str_replace(basename(__DIR__) . '/' . basename(__FILE__), '', realpath(__FILE__)) . '/required.php';

or for php < 5.3:

str_replace(basename(dirname(__FILE__)) . '/' . basename(__FILE__), '', realpath(__FILE__)) . '/required.php';

CSS for grabbing cursors (drag & drop)

I may be late, but you can try the following code, which worked for me for Drag and Drop.

.dndclass{
    cursor: url('../images/grab1.png'), auto; 

}

.dndclass:active {
    cursor: url('../images/grabbing1.png'), auto;
}

You can use the images below in the URL above. Make sure it is a PNG transparent image. If not, download one from google.

enter image description here enter image description here

Sending HTML mail using a shell script

Another option is using msmtp.

What you need is to set up your .msmtprc with something like this (example is using gmail):

account default
host smtp.gmail.com
port 587
from [email protected]
tls on
tls_starttls on
tls_trust_file ~/.certs/equifax.pem
auth on
user [email protected]
password <password>
logfile ~/.msmtp.log

Then just call:

(echo "Subject: <subject>"; echo; echo "<message>") | msmtp <[email protected]>

in your script

Update: For HTML mail you have to put the headers as well, so you might want to make a file like this:

From: [email protected]
To: [email protected]
Subject: Important message
Mime-Version: 1.0
Content-Type: text/html

<h1>Mail body will be here</h1>
The mail body <b>should</b> start after one blank line from the header.

And mail it like

cat email-template | msmtp [email protected]

The same can be done via command line as well, but it might be easier using a file.

How do I force a favicon refresh?

I recently restored my bookmarks and was looking for a way to restore the FavIcons without visiting each page. My search brought me to this thread.

For those in a similar circumstance merely download the FAVICON RELOADER addon. Once installed you will find the "reload favorite icons" command in your BOOKMARKS dropdown menu.

https://addons.mozilla.org/en-US/firefox/addon/faviconreloader/?src=api

How to change indentation in Visual Studio Code?

You might also want to set the editor.detectIndentation to false, in addition to Elliot-J's answer.

VSCode will overwrite your editor.tabSize and editor.insertSpaces settings per file if it detects that a file has a different tab or spaces indentation pattern. You can run into this issue if you add existing files to your project, or if you add files using code generators like Angular Cli. The above setting prevents VSCode from doing this.

How to tell if a connection is dead in python

From the link Jweede posted:

exception socket.timeout:

This exception is raised when a timeout occurs on a socket
which has had timeouts enabled via a prior call to settimeout().
The accompanying value is a string whose value is currently
always “timed out”.

Here are the demo server and client programs for the socket module from the python docs

# Echo server program
import socket

HOST = ''                 # Symbolic name meaning all available interfaces
PORT = 50007              # Arbitrary non-privileged port
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
print 'Connected by', addr
while 1:
    data = conn.recv(1024)
    if not data: break
    conn.send(data)
conn.close()

And the client:

# Echo client program
import socket

HOST = 'daring.cwi.nl'    # The remote host
PORT = 50007              # The same port as used by the server
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
s.send('Hello, world')
data = s.recv(1024)
s.close()
print 'Received', repr(data)

On the docs example page I pulled these from, there are more complex examples that employ this idea, but here is the simple answer:

Assuming you're writing the client program, just put all your code that uses the socket when it is at risk of being dropped, inside a try block...

try:
    s.connect((HOST, PORT))
    s.send("Hello, World!")
    ...
except socket.timeout:
    # whatever you need to do when the connection is dropped

Tools: replace not replacing in Android manifest

My problem is multi modules project with base module, app module and feature module. Each module has AndroidManifest of its own, and I implemented build variant for debug and main. So we must sure that "android:name" just declared in Manifest of debug and main only, and do not set it in any of Manifest in child module. Ex: Manifest in main:

 <application
        android:name=".App"/>

Manifest in debug:

<application
        tools:replace="android:name"
        android:name=".DebugApp"
        />

Do not set "android:name" in other Manifest files like this:

<application android:name=".App">

Just define in feature module like this and it will merged fine

<application> 

2 "style" inline css img tags?

if use Inline CSS you use

<img src="http://img705.imageshack.us/img705/119/original120x75.png" style="height:100px;width:100px;" alt="705"/>

Otherwise you can use class properties which related with a separate css file (styling your website) as like In CSS File

.imgSize {height:100px;width:100px;}

In HTML File

<img src="http://img705.imageshack.us/img705/119/original120x75.png" style="height:100px;width:100px;" alt="705"/>

How to play ringtone/alarm sound in Android

Your example is basically what I'm using. It never works on the emulator, however, because the emulator doesn't have any ringtones by default, and content://settings/system/ringtone doesn't resolve to anything playable. It works fine on my actual phone.