Programs & Examples On #Codec

Codec is an implementation of compression and decompression of digital data streams and signals in different scales. Digital data like audio, video and electronic documents are been compressed and decompressed using codecs.

FlutterError: Unable to load asset

I ran into this issue and very nearly gave up on Flutter until I stumbled upon the cause. In my case what I was doing was along the following lines

static Future<String> resourceText(String resName) async
{
 try
 { 
  ZLibCodec zlc = new ZLibCodec(gzip:false,raw:true,level:9);
  var data= await rootBundle.load('assets/path/to/$resName');
  String result = new 
  String.fromCharCodes(zlc.decode(puzzleData.buffer.asUint8List()));
  return puzzle;
 } catch(e)
 {
  debugPrint('Resource Error $resName $e');
  return ''; 
 } 
}

static Future<String> fallBackText(String textName) async
{
 if (testCondtion) return 'Some Required Text';
 else return resourceText('default');
} 

where Some Required Text was a text string sent back if the testCondition was being met. Failing that I was trying to pick up default text from the app resources and send that back instead. My mistake was in the line return resourceText('default');. After changing it to read return await resourceText('default') things worked just as expected.

This issue arises from the fact that rootBundle.load operates asynchronously. In order to return its results correctly we need to await their availability which I had failed to do. It strikes me as slightly surprising that neither the Flutter VSCode plugin nor the Flutter build process flag up this as an error. While there may well be other reasons why rootBundle.load fails this answer will, hopefully, help others who are running into mysterious asset load failures in Flutter.

TypeError: Object of type 'bytes' is not JSON serializable

You are creating those bytes objects yourself:

item['title'] = [t.encode('utf-8') for t in title]
item['link'] = [l.encode('utf-8') for l in link]
item['desc'] = [d.encode('utf-8') for d in desc]
items.append(item)

Each of those t.encode(), l.encode() and d.encode() calls creates a bytes string. Do not do this, leave it to the JSON format to serialise these.

Next, you are making several other errors; you are encoding too much where there is no need to. Leave it to the json module and the standard file object returned by the open() call to handle encoding.

You also don't need to convert your items list to a dictionary; it'll already be an object that can be JSON encoded directly:

class W3SchoolPipeline(object):    
    def __init__(self):
        self.file = open('w3school_data_utf8.json', 'w', encoding='utf-8')

    def process_item(self, item, spider):
        line = json.dumps(item) + '\n'
        self.file.write(line)
        return item

I'm guessing you followed a tutorial that assumed Python 2, you are using Python 3 instead. I strongly suggest you find a different tutorial; not only is it written for an outdated version of Python, if it is advocating line.decode('unicode_escape') it is teaching some extremely bad habits that'll lead to hard-to-track bugs. I can recommend you look at Think Python, 2nd edition for a good, free, book on learning Python 3.

Load local images in React.js

In order to load local images to your React.js application, you need to add require parameter in media sections like or Image tags, as below:

image={require('./../uploads/temp.jpg')}

error UnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 0: invalid start byte

Use this solution it will strip out (ignore) the characters and return the string without them. Only use this if your need is to strip them not convert them.

with open(path, encoding="utf8", errors='ignore') as f:

Using errors='ignore' You'll just lose some characters. but if your don't care about them as they seem to be extra characters originating from a the bad formatting and programming of the clients connecting to my socket server. Then its a easy direct solution. reference

Vertical Align Center in Bootstrap 4

Because none of the above worked for me, I am adding another answer.

Goal: To vertically and horizontally align a div on a page using bootstrap 4 flexbox classes.

Step 1: Set your outermost div to a height of 100vh. This sets the height to 100% of the Veiwport Height. If you don't do this, nothing else will work. Setting it to a height of 100% is only relative to the parent, so if the parent is not the full height of the viewport, nothing will work. In the example below, I set the Body to 100vh.

Step 2: Set the container div to be the flexbox container with the d-flex class.

Step 3: Center div horizontally with the justify-content-center class.

Step 4: Center div vertically with the align-items-center

Step 5: Run page, view your vertically and horizontally centered div.

Note that there is no special class that needs to be set on the centered div itself (the child div)

<body style="background-color:#f2f2f2; height:100vh;">

<div class="h-100 d-flex justify-content-center align-items-center">
    <div style="height:600px; background-color:white; width:600px;">
</div>

</div>

</body>

How do I get rid of the b-prefix in a string in python?

****How to remove b' ' chars which is decoded string in python ****

import base64
a='cm9vdA=='
b=base64.b64decode(a).decode('utf-8')
print(b)

(unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape

As per String literals:

String literals can be enclosed within single quotes (i.e. '...') or double quotes (i.e. "..."). They can also be enclosed in matching groups of three single or double quotes (these are generally referred to as triple-quoted strings).

The backslash character (i.e. \) is used to escape characters which otherwise will have a special meaning, such as newline, backslash itself, or the quote character. String literals may optionally be prefixed with a letter r or R. Such strings are called raw strings and use different rules for backslash escape sequences.

In triple-quoted strings, unescaped newlines and quotes are allowed, except that the three unescaped quotes in a row terminate the string.

Unless an r or R prefix is present, escape sequences in strings are interpreted according to rules similar to those used by Standard C.

So ideally you need to replace the line:

data = open("C:\Users\miche\Documents\school\jaar2\MIK\2.6\vektis_agb_zorgverlener")

To any one of the following characters:

  • Using raw prefix and single quotes (i.e. '...'):

      data = open(r'C:\Users\miche\Documents\school\jaar2\MIK\2.6\vektis_agb_zorgverlener')
    
  • Using double quotes (i.e. "...") and escaping backslash character (i.e. \):

      data = open("C:\\Users\\miche\\Documents\\school\\jaar2\\MIK\\2.6\\vektis_agb_zorgverlener")
    
  • Using double quotes (i.e. "...") and forwardslash character (i.e. /):

      data = open("C:/Users/miche/Documents/school/jaar2/MIK/2.6/vektis_agb_zorgverlener")
    

Django - Did you forget to register or load this tag?

In gameprofile.html please change the tag {% endblock content %} to {% endblock %} then it works otherwise django will not load the endblock and give error.

HTML 5 Video "autoplay" not automatically starting in CHROME

I was just reading this article, and it says:

Important: the order of the video files is vital; Chrome currently has a bug in which it will not autoplay a .webm video if it comes after anything else.

So it looks like your problem would be solved if you put the .webm first in your list of sources. Hope that helps.

Download and save PDF file with Python requests module

In Python 3, I find pathlib is the easiest way to do this. Request's response.content marries up nicely with pathlib's write_bytes.

from pathlib import Path
import requests
filename = Path('metadata.pdf')
url = 'http://www.hrecos.org//images/Data/forweb/HRTVBSH.Metadata.pdf'
response = requests.get(url)
filename.write_bytes(response.content)

Call to undefined function App\Http\Controllers\ [ function name ]

say you define the static getFactorial function inside a CodeController

then this is the way you need to call a static function, because static properties and methods exists with in the class, not in the objects created using the class.

CodeController::getFactorial($index);

----------------UPDATE----------------

To best practice I think you can put this kind of functions inside a separate file so you can maintain with more easily.

to do that

create a folder inside app directory and name it as lib (you can put a name you like).

this folder to needs to be autoload to do that add app/lib to composer.json as below. and run the composer dumpautoload command.

"autoload": {
    "classmap": [
                "app/commands",
                "app/controllers",
                ............
                "app/lib"
    ]
},

then files inside lib will autoloaded.

then create a file inside lib, i name it helperFunctions.php

inside that define the function.

if ( ! function_exists('getFactorial'))
{

    /**
     * return the factorial of a number
     *
     * @param $number
     * @return string
     */
    function getFactorial($date)
    {
        $fact = 1;

        for($i = 1; $i <= $num ;$i++)
            $fact = $fact * $i;

        return $fact;

     }
}

and call it anywhere within the app as

$fatorial_value = getFactorial(225);

FFMPEG mp4 from http live streaming m3u8 file?

Your command is completely incorrect. The output format is not rawvideo and you don't need the bitstream filter h264_mp4toannexb which is used when you want to convert the h264 contained in an mp4 to the Annex B format used by MPEG-TS for example. What you want to use instead is the aac_adtstoasc for the AAC streams.

ffmpeg -i http://.../playlist.m3u8 -c copy -bsf:a aac_adtstoasc output.mp4

Significance of ios_base::sync_with_stdio(false); cin.tie(NULL);

Lot's of great answer. I just want to add a small note about decoupling the stream.

cin.tie(NULL);

I have faced an issue while decoupling the stream with CodeChef platform. When I submitted my code, the platform response was "Wrong Answer" but after tying the stream and testing the submission. It worked.

So, If anyone wants to untie the stream, the output stream must be flushed.

Edit: I am not familiar with all the platform but this is what I have experienced.

UnicodeEncodeError: 'ascii' codec can't encode character at special name

You really want to do this

flog.write("\nCompany Name: "+ pCompanyName.encode('utf-8'))

This is the "encode late" strategy described in this unicode presentation (slides 32 through 35).

Writing an mp4 video using python opencv

This is the default code given to save a video captured by camera

import numpy as np
import cv2

cap = cv2.VideoCapture(0)

# Define the codec and create VideoWriter object
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi',fourcc, 20.0, (640,480))

while(cap.isOpened()):
    ret, frame = cap.read()
    if ret==True:
        frame = cv2.flip(frame,0)

        # write the flipped frame
        out.write(frame)

        cv2.imshow('frame',frame)
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break
    else:
        break

# Release everything if job is finished
cap.release()
out.release()
cv2.destroyAllWindows()

For about two minutes of a clip captured that FULL HD

Using

cap = cv2.VideoCapture(0,cv2.CAP_DSHOW)
cap.set(3,1920)
cap.set(4,1080)
out = cv2.VideoWriter('output.avi',fourcc, 20.0, (1920,1080))

The file saved was more than 150MB

Then had to use ffmpeg to reduce the size of the file saved, between 30MB to 60MB based on the quality of the video that is required changed using crf lower the crf better the quality of the video and larger the file size generated. You can also change the format avi,mp4,mkv,etc

Then i found ffmpeg-python

Here a code to save numpy array of each frame as video using ffmpeg-python

import numpy as np
import cv2
import ffmpeg

def save_video(cap,saving_file_name,fps=33.0):

    while cap.isOpened():
        ret, frame = cap.read()
        if ret:
            i_width,i_height = frame.shape[1],frame.shape[0]
            break

    process = (
    ffmpeg
        .input('pipe:',format='rawvideo', pix_fmt='rgb24',s='{}x{}'.format(i_width,i_height))
        .output(saved_video_file_name,pix_fmt='yuv420p',vcodec='libx264',r=fps,crf=37)
        .overwrite_output()
        .run_async(pipe_stdin=True)
    )

    return process

if __name__=='__main__':

    cap = cv2.VideoCapture(0,cv2.CAP_DSHOW)
    cap.set(3,1920)
    cap.set(4,1080)
    saved_video_file_name = 'output.avi'
    process = save_video(cap,saved_video_file_name)

    while(cap.isOpened()):
        ret, frame = cap.read()
        if ret==True:
            frame = cv2.flip(frame,0)
            process.stdin.write(
                cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
                    .astype(np.uint8)
                    .tobytes()
                    )

            cv2.imshow('frame',frame)
            if cv2.waitKey(1) & 0xFF == ord('q'):
                process.stdin.close()
                process.wait()
                cap.release()
                cv2.destroyAllWindows()
                break
        else:
            process.stdin.close()
            process.wait()
            cap.release()
            cv2.destroyAllWindows()
            break

Encoding Error in Panda read_csv

This works in Mac as well you can use

df= pd.read_csv('Region_count.csv', encoding ='latin1')

Deserialize JSON with Jackson into Polymorphic Types - A Complete Example is giving me a compile error

If using the fasterxml then,

these changes might be needed

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.Version;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.node.ObjectNode;

in main method--

use

SimpleModule module =
  new SimpleModule("PolymorphicAnimalDeserializerModule");

instead of

new SimpleModule("PolymorphicAnimalDeserializerModule",
      new Version(1, 0, 0, null));

and in Animal deserialize() function, make below changes

//Iterator<Entry<String, JsonNode>> elementsIterator =  root.getFields();
Iterator<Entry<String, JsonNode>> elementsIterator = root.fields();

//return mapper.readValue(root, animalClass);
return  mapper.convertValue(root, animalClass); 

This works for fasterxml.jackson. If it still complains of the class fields. Use the same format as in the json for the field names (with "_" -underscore). as this
//mapper.setPropertyNamingStrategy(new CamelCaseNamingStrategy()); might not be supported.

abstract class Animal
{
  public String name;
}

class Dog extends Animal
{
  public String breed;
  public String leash_color;
}

class Cat extends Animal
{
  public String favorite_toy;
}

class Bird extends Animal
{
  public String wing_span;
  public String preferred_food;
}

How to open html file?

CODE:

import codecs

path="D:\\Users\\html\\abc.html" 
file=codecs.open(path,"rb")
file1=file.read()
file1=str(file1)

UnicodeEncodeError: 'charmap' codec can't encode characters

In Python 3.7, and running Windows 10 this worked (I am not sure whether it will work on other platforms and/or other versions of Python)

Replacing this line:

with open('filename', 'w') as f:

With this:

with open('filename', 'w', encoding='utf-8') as f:

The reason why it is working is because the encoding is changed to UTF-8 when using the file, so characters in UTF-8 are able to be converted to text, instead of returning an error when it encounters a UTF-8 character that is not suppord by the current encoding.

Gradle DSL method not found: 'runProguard'

If you are migrating to 1.0.0 you need to change the following properties.

In the Project's build.gradle file you need to replace minifyEnabled.

Hence your new build type should be

buildTypes {
    release {
        minifyEnabled true
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'        
    }
}

Also make sure that gradle version is 1.0.0 like

classpath 'com.android.tools.build:gradle:1.0.0'

in the build.gradle file.

This should solve the problem.

Source: http://tools.android.com/tech-docs/new-build-system/migrating-to-1-0-0

What steps are needed to stream RTSP from FFmpeg?

You can use FFserver to stream a video using RTSP.

Just change console syntax to something like this:

ffmpeg -i space.mp4 -vcodec libx264 -tune zerolatency -crf 18 http://localhost:1234/feed1.ffm

Create a ffserver.config file (sample) where you declare HTTPPort, RTSPPort and SDP stream. Your config file could look like this (some important stuff might be missing):

HTTPPort 1234
RTSPPort 1235

<Feed feed1.ffm>
        File /tmp/feed1.ffm
        FileMaxSize 2M
        ACL allow 127.0.0.1
</Feed>

<Stream test1.sdp>
    Feed feed1.ffm
    Format rtp
    Noaudio
    VideoCodec libx264
    AVOptionVideo flags +global_header
    AVOptionVideo me_range 16
    AVOptionVideo qdiff 4
    AVOptionVideo qmin 10
    AVOptionVideo qmax 51
    ACL allow 192.168.0.0 192.168.255.255
</Stream>

With such setup you can watch the stream with i.e. VLC by typing:

rtsp://192.168.0.xxx:1235/test1.sdp

Here is the FFserver documentation.

Python NLTK: SyntaxError: Non-ASCII character '\xc3' in file (Sentiment Analysis -NLP)

Add the following to the top of your file # coding=utf-8

If you go to the link in the error you can seen the reason why:

Defining the Encoding

Python will default to ASCII as standard encoding if no other encoding hints are given. To define a source code encoding, a magic comment must be placed into the source files either as first or second line in the file, such as: # coding=

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 23: ordinal not in range(128)

You are encoding to UTF-8, then re-encoding to UTF-8. Python can only do this if it first decodes again to Unicode, but it has to use the default ASCII codec:

>>> u'ñ'
u'\xf1'
>>> u'ñ'.encode('utf8')
'\xc3\xb1'
>>> u'ñ'.encode('utf8').encode('utf8')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 0: ordinal not in range(128)

Don't keep encoding; leave encoding to UTF-8 to the last possible moment instead. Concatenate Unicode values instead.

You can use str.join() (or, rather, unicode.join()) here to concatenate the three values with dashes in between:

nombre = u'-'.join(fabrica, sector, unidad)
return nombre.encode('utf-8')

but even encoding here might be too early.

Rule of thumb: decode the moment you receive the value (if not Unicode values supplied by an API already), encode only when you have to (if the destination API does not handle Unicode values directly).

How to encode text to base64 in python

Remember to import base64 and that b64encode takes bytes as an argument.

import base64
base64.b64encode(bytes('your string', 'utf-8'))

gcc: undefined reference to

However, avpicture_get_size is defined.

No, as the header (<libavcodec/avcodec.h>) just declares it.

The definition is in the library itself.

So you might like to add the linker option to link libavcodec when invoking gcc:

-lavcodec

Please also note that libraries need to be specified on the command line after the files needing them:

gcc -I$HOME/ffmpeg/include program.c -lavcodec

Not like this:

gcc -lavcodec -I$HOME/ffmpeg/include program.c

Referring to Wyzard's comment, the complete command might look like this:

gcc -I$HOME/ffmpeg/include program.c -L$HOME/ffmpeg/lib -lavcodec

For libraries not stored in the linkers standard location the option -L specifies an additional search path to lookup libraries specified using the -l option, that is libavcodec.x.y.z in this case.


For a detailed reference on GCC's linker option, please read here.

PhoneGap Eclipse Issue - eglCodecCommon glUtilsParamSize: unknow param errors

This is caused if you use the "Use host GPU" setting of the emulator and it will disappear after you uncheck this option. If you still need "Use host GPU", you can just filter out the errors by customizing the Logcat Filter. Enter ^(?!eglCodecCommon) into the "by Log Tag (regex)" field in order to strip out the unwanted lines from the Logcat output.

UnicodeDecodeError: 'utf8' codec can't decode byte 0xa5 in position 0: invalid start byte

After trying all the aforementioned workarounds, if it still throws the same error, you can try exporting the file as CSV (a second time if you already have). Especially if you're using scikit learn, it is best to import the dataset as a CSV file.

I spent hours together, whereas the solution was this simple. Export the file as a CSV to the directory where Anaconda or your classifier tools are installed and try.

Best approach to real time http streaming to HTML5 video client

Thanks everyone especially szatmary as this is a complex question and has many layers to it, all which have to be working before you can stream live video. To clarify my original question and HTML5 video use vs flash - my use case has a strong preference for HTML5 because it is generic, easy to implement on the client and the future. Flash is a distant second best so lets stick with HTML5 for this question.

I learnt a lot through this exercise and agree live streaming is much harder than VOD (which works well with HTML5 video). But I did get this to work satisfactorily for my use case and the solution worked out to be very simple, after chasing down more complex options like MSE, flash, elaborate buffering schemes in Node. The problem was that FFMPEG was corrupting the fragmented MP4 and I had to tune the FFMPEG parameters, and the standard node stream pipe redirection over http that I used originally was all that was needed.

In MP4 there is a 'fragmentation' option that breaks the mp4 into much smaller fragments which has its own index and makes the mp4 live streaming option viable. But not possible to seek back into the stream (OK for my use case), and later versions of FFMPEG support fragmentation.

Note timing can be a problem, and with my solution I have a lag of between 2 and 6 seconds caused by a combination of the remuxing (effectively FFMPEG has to receive the live stream, remux it then send it to node for serving over HTTP). Not much can be done about this, however in Chrome the video does try to catch up as much as it can which makes the video a bit jumpy but more current than IE11 (my preferred client).

Rather than explaining how the code works in this post, check out the GIST with comments (the client code isn't included, it is a standard HTML5 video tag with the node http server address). GIST is here: https://gist.github.com/deandob/9240090

I have not been able to find similar examples of this use case, so I hope the above explanation and code helps others, especially as I have learnt so much from this site and still consider myself a beginner!

Although this is the answer to my specific question, I have selected szatmary's answer as the accepted one as it is the most comprehensive.

How to deploy correctly when using Composer's develop / production switch?

Actually, I would highly recommend AGAINST installing dependencies on the production server.

My recommendation is to checkout the code on a deployment machine, install dependencies as needed (this includes NOT installing dev dependencies if the code goes to production), and then move all the files to the target machine.

Why?

  • on shared hosting, you might not be able to get to a command line
  • even if you did, PHP might be restricted there in terms of commands, memory or network access
  • repository CLI tools (Git, Svn) are likely to not be installed, which would fail if your lock file has recorded a dependency to checkout a certain commit instead of downloading that commit as ZIP (you used --prefer-source, or Composer had no other way to get that version)
  • if your production machine is more like a small test server (think Amazon EC2 micro instance) there is probably not even enough memory installed to execute composer install
  • while composer tries to no break things, how do you feel about ending with a partially broken production website because some random dependency could not be loaded during Composers install phase

Long story short: Use Composer in an environment you can control. Your development machine does qualify because you already have all the things that are needed to operate Composer.

What's the correct way to deploy this without installing the -dev dependencies?

The command to use is

composer install --no-dev

This will work in any environment, be it the production server itself, or a deployment machine, or the development machine that is supposed to do a last check to find whether any dev requirement is incorrectly used for the real software.

The command will not install, or actively uninstall, the dev requirements declared in the composer.lock file.

If you don't mind deploying development software components on a production server, running composer install would do the same job, but simply increase the amount of bytes moved around, and also create a bigger autoloader declaration.

How to playback MKV video in web browser?

To use video extensions that are MKV. You should use video, not source

For example :

_x000D_
_x000D_
  <!-- mkv -->
  <video width="320" height="240" controls src="assets/animation.mkv"></video>
<!-- mp4 -->
  <video width="320" height="240" controls>
    <source src="assets/animation.mp4" type="video/mp4" />
  </video>
_x000D_
_x000D_
_x000D_ My answer may be incomprehensible to you, so if you do not understand, click on this

How to fix: "UnicodeDecodeError: 'ascii' codec can't decode byte"

Encode converts a unicode object in to a string object. I think you are trying to encode a string object. first convert your result into unicode object and then encode that unicode object into 'utf-8'. for example

    result = yourFunction()
    result.decode().encode('utf-8')

HTML5 Video not working in IE 11

It was due to IE Document-mode version too low. Press 'F12' and using higher version( My case, above version 9 is OK)

Multiple dex files define Landroid/support/v4/accessibilityservice/AccessibilityServiceInfoCompat

Since A picture is worth a thousand words

To make it easier and faster to get this task done with beginners like me. this is the screenshots that shows the answer posted by @edsappfactory.com that worked for me:

First open the Gradle view on the right side of Androidstudio, in your app's item go to Tasks then Android then right-click androidDependencies then choose Run:

step 1

Second you will see something like this :

Step 2

The main reason i posted this that it was not easy to know where to execute a gradle task or the commands posted above. So this is where to excute them as well.

SO, to execute gradle command:

First:

first

Second:

second

Easy as it is.

Thats it.

Thank you.

ImportError: No module named dateutil.parser

I had the similar problem. This is the stack trace:

Traceback (most recent call last):
File "/usr/local/bin/aws", line 19, in <module> import awscli.clidriver
File "/usr/local/lib/python2.7/dist-packages/awscli/clidriver.py", line 17, in <module> import botocore.session
File "/usr/local/lib/python2.7/dist-packages/botocore/session.py", line 30, in <module> import botocore.credentials
File "/usr/local/lib/python2.7/dist-packages/botocore/credentials.py", line 27, in <module> from dateutil.parser import parse
ImportError: No module named dateutil.parser

I tried to (re-)install dateutil.parser through all possible ways. It was unsuccessful.

I solved it with

pip3 uninstall awscli
pip3 install awscli

Android Gradle plugin 0.7.0: "duplicate files during packaging of APK"

Have a look at Sakiboy's comment!


Outdated answer

From Gradle 0.9.1 the following is supported:

android.packagingOptions {
    pickFirst 'META-INF/LICENSE.txt'
}

More information in the Gradle release notes.

Javascript: console.log to html

Create an ouput

<div id="output"></div>

Write to it using JavaScript

var output = document.getElementById("output");
output.innerHTML = "hello world";

If you would like it to handle more complex output values, you can use JSON.stringify

var myObj = {foo: "bar"};
output.innerHTML = JSON.stringify(myObj);

UnicodeEncodeError: 'ascii' codec can't encode character u'\xe9' in position 7: ordinal not in range(128)

You need to encode Unicode explicitly before writing to a file, otherwise Python does it for you with the default ASCII codec.

Pick an encoding and stick with it:

f.write(printinfo.encode('utf8') + '\n')

or use io.open() to create a file object that'll encode for you as you write to the file:

import io

f = io.open(filename, 'w', encoding='utf8')

You may want to read:

before continuing.

Playing m3u8 Files with HTML Video Tag

In normally html5 video player will support mp4, WebM, 3gp and OGV format directly.

    <video controls>
      <source src=http://techslides.com/demos/sample-videos/small.webm type=video/webm>
      <source src=http://techslides.com/demos/sample-videos/small.ogv type=video/ogg>
      <source src=http://techslides.com/demos/sample-videos/small.mp4 type=video/mp4>
      <source src=http://techslides.com/demos/sample-videos/small.3gp type=video/3gp>
    </video>

We can add an external HLS js script in web application.

    <!DOCTYPE html>
    <html>
    <head>
    <meta charset=utf-8 />
    <title>Your title</title>
      
    
      <link href="https://unpkg.com/video.js/dist/video-js.css" rel="stylesheet">
      <script src="https://unpkg.com/video.js/dist/video.js"></script>
      <script src="https://unpkg.com/videojs-contrib-hls/dist/videojs-contrib-hls.js"></script>
       
    </head>
    <body>
      <video id="my_video_1" class="video-js vjs-fluid vjs-default-skin" controls preload="auto"
      data-setup='{}'>
        <source src="https://cdn3.wowza.com/1/ejBGVnFIOW9yNlZv/cithRSsv/hls/live/playlist.m3u8" type="application/x-mpegURL">
      </video>
      
    <script>
    var player = videojs('my_video_1');
    player.play();
    </script>
      
    </body>
    </html>

"for line in..." results in UnicodeDecodeError: 'utf-8' codec can't decode byte

The following also worked for me. ISO 8859-1 is going to save a lot, hahaha - mainly if using Speech Recognition APIs.

Example:

file = open('../Resources/' + filename, 'r', encoding="ISO-8859-1");

How to write UTF-8 in a CSV file

From your shell run:

pip2 install unicodecsv

And (unlike the original question) presuming you're using Python's built in csv module, turn
import csv into
import unicodecsv as csv in your code.

Reverse a string without using reversed() or [::-1]?

Inspired by Jon's answer, how about this one

word = 'hello'
q = deque(word)
''.join(q.pop() for _ in range(len(word)))

UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 13: ordinal not in range(128)

This works fine for me.

f = open(file_path, 'r+', encoding="utf-8")

You can add a third parameter encoding to ensure the encoding type is 'utf-8'

Note: this method works fine in Python3, I did not try it in Python2.7.

Cutting the videos based on start and end time using ffmpeg

You probably do not have a keyframe at the 3 second mark. Because non-keyframes encode differences from other frames, they require all of the data starting with the previous keyframe.

With the mp4 container it is possible to cut at a non-keyframe without re-encoding using an edit list. In other words, if the closest keyframe before 3s is at 0s then it will copy the video starting at 0s and use an edit list to tell the player to start playing 3 seconds in.

If you are using the latest ffmpeg from git master it will do this using an edit list when invoked using the command that you provided. If this is not working for you then you are probably either using an older version of ffmpeg, or your player does not support edit lists. Some players will ignore the edit list and always play all of the media in the file from beginning to end.

If you want to cut precisely starting at a non-keyframe and want it to play starting at the desired point on a player that does not support edit lists, or want to ensure that the cut portion is not actually in the output file (for example if it contains confidential information), then you can do that by re-encoding so that there will be a keyframe precisely at the desired start time. Re-encoding is the default if you do not specify copy. For example:

ffmpeg -i movie.mp4 -ss 00:00:03 -t 00:00:08 -async 1 cut.mp4

When re-encoding you may also wish to include additional quality-related options or a particular AAC encoder. For details, see ffmpeg's x264 Encoding Guide for video and AAC Encoding Guide for audio.

Also, the -t option specifies a duration, not an end time. The above command will encode 8s of video starting at 3s. To start at 3s and end at 8s use -t 5. If you are using a current version of ffmpeg you can also replace -t with -to in the above command to end at the specified time.

Python unicode equal comparison failed

You may use the == operator to compare unicode objects for equality.

>>> s1 = u'Hello'
>>> s2 = unicode("Hello")
>>> type(s1), type(s2)
(<type 'unicode'>, <type 'unicode'>)
>>> s1==s2
True
>>> 
>>> s3='Hello'.decode('utf-8')
>>> type(s3)
<type 'unicode'>
>>> s1==s3
True
>>> 

But, your error message indicates that you aren't comparing unicode objects. You are probably comparing a unicode object to a str object, like so:

>>> u'Hello' == 'Hello'
True
>>> u'Hello' == '\x81\x01'
__main__:1: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal
False

See how I have attempted to compare a unicode object against a string which does not represent a valid UTF8 encoding.

Your program, I suppose, is comparing unicode objects with str objects, and the contents of a str object is not a valid UTF8 encoding. This seems likely the result of you (the programmer) not knowing which variable holds unicide, which variable holds UTF8 and which variable holds the bytes read in from a file.

I recommend http://nedbatchelder.com/text/unipain.html, especially the advice to create a "Unicode Sandwich."

UnicodeDecodeError when reading CSV file in Pandas with Python

read_csv takes an encoding option to deal with files in different formats. I mostly use read_csv('file', encoding = "ISO-8859-1"), or alternatively encoding = "utf-8" for reading, and generally utf-8 for to_csv.

You can also use one of several alias options like 'latin' instead of 'ISO-8859-1' (see python docs, also for numerous other encodings you may encounter).

See relevant Pandas documentation, python docs examples on csv files, and plenty of related questions here on SO. A good background resource is What every developer should know about unicode and character sets.

To detect the encoding (assuming the file contains non-ascii characters), you can use enca (see man page) or file -i (linux) or file -I (osx) (see man page).

Why do I get a SyntaxError for a Unicode escape in my file path?

C:\\Users\\expoperialed\\Desktop\\Python This syntax worked for me.

u'\ufeff' in Python string

Here is based on the answer from Mark Tolonen. The string included different languages of the word 'test' that's separated by '|', so you can see the difference.

u = u'ABCtestß???másbêta|test|??????|??|??|???|???????|???????|????????|ki?m tra|Ölçek|'
e8 = u.encode('utf-8')        # encode without BOM
e8s = u.encode('utf-8-sig')   # encode with BOM
e16 = u.encode('utf-16')      # encode with BOM
e16le = u.encode('utf-16le')  # encode without BOM
e16be = u.encode('utf-16be')  # encode without BOM
print('utf-8     %r' % e8)
print('utf-8-sig %r' % e8s)
print('utf-16    %r' % e16)
print('utf-16le  %r' % e16le)
print('utf-16be  %r' % e16be)
print()
print('utf-8  w/ BOM decoded with utf-8     %r' % e8s.decode('utf-8'))
print('utf-8  w/ BOM decoded with utf-8-sig %r' % e8s.decode('utf-8-sig'))
print('utf-16 w/ BOM decoded with utf-16    %r' % e16.decode('utf-16'))
print('utf-16 w/ BOM decoded with utf-16le  %r' % e16.decode('utf-16le'))

Here is a test run:

>>> u = u'ABCtestß???másbêta|test|??????|??|??|???|???????|???????|????????|ki?m tra|Ölçek|'
>>> e8 = u.encode('utf-8')        # encode without BOM
>>> e8s = u.encode('utf-8-sig')   # encode with BOM
>>> e16 = u.encode('utf-16')      # encode with BOM
>>> e16le = u.encode('utf-16le')  # encode without BOM
>>> e16be = u.encode('utf-16be')  # encode without BOM
>>> print('utf-8     %r' % e8)
utf-8     b'ABCtest\xce\xb2\xe8\xb2\x9d\xe5\xa1\x94\xec\x9c\x84m\xc3\xa1sb\xc3\xaata|test|\xd8\xa7\xd8\xae\xd8\xaa\xd8\xa8\xd8\xa7\xd8\xb1|\xe6\xb5\x8b\xe8\xaf\x95|\xe6\xb8\xac\xe8\xa9\xa6|\xe3\x83\x86\xe3\x82\xb9\xe3\x83\x88|\xe0\xa4\xaa\xe0\xa4\xb0\xe0\xa5\x80\xe0\xa4\x95\xe0\xa5\x8d\xe0\xa4\xb7\xe0\xa4\xbe|\xe0\xb4\xaa\xe0\xb4\xb0\xe0\xb4\xbf\xe0\xb4\xb6\xe0\xb5\x8b\xe0\xb4\xa7\xe0\xb4\xa8|\xd7\xa4\xd6\xbc\xd7\xa8\xd7\x95\xd7\x91\xd7\x99\xd7\xa8\xd7\x9f|ki\xe1\xbb\x83m tra|\xc3\x96l\xc3\xa7ek|'
>>> print('utf-8-sig %r' % e8s)
utf-8-sig b'\xef\xbb\xbfABCtest\xce\xb2\xe8\xb2\x9d\xe5\xa1\x94\xec\x9c\x84m\xc3\xa1sb\xc3\xaata|test|\xd8\xa7\xd8\xae\xd8\xaa\xd8\xa8\xd8\xa7\xd8\xb1|\xe6\xb5\x8b\xe8\xaf\x95|\xe6\xb8\xac\xe8\xa9\xa6|\xe3\x83\x86\xe3\x82\xb9\xe3\x83\x88|\xe0\xa4\xaa\xe0\xa4\xb0\xe0\xa5\x80\xe0\xa4\x95\xe0\xa5\x8d\xe0\xa4\xb7\xe0\xa4\xbe|\xe0\xb4\xaa\xe0\xb4\xb0\xe0\xb4\xbf\xe0\xb4\xb6\xe0\xb5\x8b\xe0\xb4\xa7\xe0\xb4\xa8|\xd7\xa4\xd6\xbc\xd7\xa8\xd7\x95\xd7\x91\xd7\x99\xd7\xa8\xd7\x9f|ki\xe1\xbb\x83m tra|\xc3\x96l\xc3\xa7ek|'
>>> print('utf-16    %r' % e16)
utf-16    b"\xff\xfeA\x00B\x00C\x00t\x00e\x00s\x00t\x00\xb2\x03\x9d\x8cTX\x04\xc7m\x00\xe1\x00s\x00b\x00\xea\x00t\x00a\x00|\x00t\x00e\x00s\x00t\x00|\x00'\x06.\x06*\x06(\x06'\x061\x06|\x00Km\xd5\x8b|\x00,nf\x8a|\x00\xc60\xb90\xc80|\x00*\t0\t@\t\x15\tM\t7\t>\t|\x00*\r0\r?\r6\rK\r'\r(\r|\x00\xe4\x05\xbc\x05\xe8\x05\xd5\x05\xd1\x05\xd9\x05\xe8\x05\xdf\x05|\x00k\x00i\x00\xc3\x1em\x00 \x00t\x00r\x00a\x00|\x00\xd6\x00l\x00\xe7\x00e\x00k\x00|\x00"
>>> print('utf-16le  %r' % e16le)
utf-16le  b"A\x00B\x00C\x00t\x00e\x00s\x00t\x00\xb2\x03\x9d\x8cTX\x04\xc7m\x00\xe1\x00s\x00b\x00\xea\x00t\x00a\x00|\x00t\x00e\x00s\x00t\x00|\x00'\x06.\x06*\x06(\x06'\x061\x06|\x00Km\xd5\x8b|\x00,nf\x8a|\x00\xc60\xb90\xc80|\x00*\t0\t@\t\x15\tM\t7\t>\t|\x00*\r0\r?\r6\rK\r'\r(\r|\x00\xe4\x05\xbc\x05\xe8\x05\xd5\x05\xd1\x05\xd9\x05\xe8\x05\xdf\x05|\x00k\x00i\x00\xc3\x1em\x00 \x00t\x00r\x00a\x00|\x00\xd6\x00l\x00\xe7\x00e\x00k\x00|\x00"
>>> print('utf-16be  %r' % e16be)
utf-16be  b"\x00A\x00B\x00C\x00t\x00e\x00s\x00t\x03\xb2\x8c\x9dXT\xc7\x04\x00m\x00\xe1\x00s\x00b\x00\xea\x00t\x00a\x00|\x00t\x00e\x00s\x00t\x00|\x06'\x06.\x06*\x06(\x06'\x061\x00|mK\x8b\xd5\x00|n,\x8af\x00|0\xc60\xb90\xc8\x00|\t*\t0\t@\t\x15\tM\t7\t>\x00|\r*\r0\r?\r6\rK\r'\r(\x00|\x05\xe4\x05\xbc\x05\xe8\x05\xd5\x05\xd1\x05\xd9\x05\xe8\x05\xdf\x00|\x00k\x00i\x1e\xc3\x00m\x00 \x00t\x00r\x00a\x00|\x00\xd6\x00l\x00\xe7\x00e\x00k\x00|"
>>> print()

>>> print('utf-8  w/ BOM decoded with utf-8     %r' % e8s.decode('utf-8'))
utf-8  w/ BOM decoded with utf-8     '\ufeffABCtestß???másbêta|test|??????|??|??|???|???????|???????|????????|ki?m tra|Ölçek|'
>>> print('utf-8  w/ BOM decoded with utf-8-sig %r' % e8s.decode('utf-8-sig'))
utf-8  w/ BOM decoded with utf-8-sig 'ABCtestß???másbêta|test|??????|??|??|???|???????|???????|????????|ki?m tra|Ölçek|'
>>> print('utf-16 w/ BOM decoded with utf-16    %r' % e16.decode('utf-16'))
utf-16 w/ BOM decoded with utf-16    'ABCtestß???másbêta|test|??????|??|??|???|???????|???????|????????|ki?m tra|Ölçek|'
>>> print('utf-16 w/ BOM decoded with utf-16le  %r' % e16.decode('utf-16le'))
utf-16 w/ BOM decoded with utf-16le  '\ufeffABCtestß???másbêta|test|??????|??|??|???|???????|???????|????????|ki?m tra|Ölçek|'

It's worth to know that only both utf-8-sig and utf-16 get back the original string after both encode and decode.

The type List is not generic; it cannot be parameterized with arguments [HTTPClient]

Your import has a subtle error:

import java.awt.List;

It should be:

import java.util.List;

The problem is that both awt and Java's util package provide a class called List. The former is a display element, the latter is a generic type used with collections. Furthermore, java.util.ArrayList extends java.util.List, not java.awt.List so if it wasn't for the generics, it would have still been a problem.

Edit: (to address further questions given by OP) As an answer to your comment, it seems that there is anther subtle import issue.

import org.omg.DynamicAny.NameValuePair;

should be

import org.apache.http.NameValuePair

nameValuePairs now uses the correct generic type parameter, the generic argument for new UrlEncodedFormEntity, which is List<? extends NameValuePair>, becomes valid, since your NameValuePair is now the same as their NameValuePair. Before, org.omg.DynamicAny.NameValuePair did not extend org.apache.http.NameValuePair and the shortened type name NameValuePair evaluated to org.omg... in your file, but org.apache... in their code.

Technically what is the main difference between Oracle JDK and OpenJDK?

Technical differences are a consequence of the goal of each one (OpenJDK is meant to be the reference implementation, open to the community, while Oracle is meant to be a commercial one)

They both have "almost" the same code of the classes in the Java API; but the code for the virtual machine itself is actually different, and when it comes to libraries, OpenJDK tends to use open libraries while Oracle tends to use closed ones; for instance, the font library.

Writing a pandas DataFrame to CSV file

When you are storing a DataFrame object into a csv file using the to_csv method, you probably wont be needing to store the preceding indices of each row of the DataFrame object.

You can avoid that by passing a False boolean value to index parameter.

Somewhat like:

df.to_csv(file_name, encoding='utf-8', index=False)

So if your DataFrame object is something like:

  Color  Number
0   red     22
1  blue     10

The csv file will store:

Color,Number
red,22
blue,10

instead of (the case when the default value True was passed)

,Color,Number
0,red,22
1,blue,10

Include .so library in apk in android studio

I've tried the solution presented in the accepted answer and it did not work for me. I wanted to share what DID work for me as it might help someone else. I've found this solution here.

Basically what you need to do is put your .so files inside a a folder named lib (Note: it is not libs and this is not a mistake). It should be in the same structure it should be in the APK file.

In my case it was:
Project:
|--lib:
|--|--armeabi:
|--|--|--.so files.

So I've made a lib folder and inside it an armeabi folder where I've inserted all the needed .so files. I then zipped the folder into a .zip (the structure inside the zip file is now lib/armeabi/*.so) I renamed the .zip file into armeabi.jar and added the line compile fileTree(dir: 'libs', include: '*.jar') into dependencies {} in the gradle's build file.

This solved my problem in a rather clean way.

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2

#!/usr/bin/python

# encoding=utf8

Try This to starting of python file

python 3.2 UnicodeEncodeError: 'charmap' codec can't encode character '\u2013' in position 9629: character maps to <undefined>

Maybe a little late to reply. I happen to run into the same problem today. I find that on Windows you can change the console encoder to utf-8 or other encoder that can represent your data. Then you can print it to sys.stdout.

First, run following code in the console:

chcp 65001
set PYTHONIOENCODING=utf-8

Then, start python do anything you want.

fatal error LNK1169: one or more multiply defined symbols found in game programming

You can't put variable definitions in header files, as these will then be a part of all source file you include the header into.

The #pragma once is just to protect against multiple inclusions in the same source file, not against multiple inclusions in multiple source files.

You could declare the variables as extern in the header file, and then define them in a single source file. Or you could declare the variables as const in the header file and then the compiler and linker will manage it.

Maven Java EE Configuration Marker with Java Server Faces 1.2

The below steps should be the simple fix to your problem

  1. Project->Properties->ProjectFacet-->Uncheck jsf apply and OK.
  2. Project->Maven->UpdateProject-->This will solve the issue.

Here while on Updating Project Maven will automatically chooses the Dynamic web module

python encoding utf-8

Unfortunately, the string.encode() method is not always reliable. Check out this thread for more information: What is the fool proof way to convert some string (utf-8 or else) to a simple ASCII string in python

Convert Python dictionary to JSON array

ensure_ascii=False really only defers the issue to the decoding stage:

>>> dict2 = {'LeafTemps': '\xff\xff\xff\xff',}
>>> json1 = json.dumps(dict2, ensure_ascii=False)
>>> print(json1)
{"LeafTemps": "????"}
>>> json.loads(json1)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/json/__init__.py", line 328, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python2.7/json/decoder.py", line 365, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib/python2.7/json/decoder.py", line 381, in raw_decode
    obj, end = self.scan_once(s, idx)
UnicodeDecodeError: 'utf8' codec can't decode byte 0xff in position 0: invalid start byte

Ultimately you can't store raw bytes in a JSON document, so you'll want to use some means of unambiguously encoding a sequence of arbitrary bytes as an ASCII string - such as base64.

>>> import json
>>> from base64 import b64encode, b64decode
>>> my_dict = {'LeafTemps': '\xff\xff\xff\xff',} 
>>> my_dict['LeafTemps'] = b64encode(my_dict['LeafTemps'])
>>> json.dumps(my_dict)
'{"LeafTemps": "/////w=="}'
>>> json.loads(json.dumps(my_dict))
{u'LeafTemps': u'/////w=='}
>>> new_dict = json.loads(json.dumps(my_dict))
>>> new_dict['LeafTemps'] = b64decode(new_dict['LeafTemps'])
>>> print new_dict
{u'LeafTemps': '\xff\xff\xff\xff'}

UnicodeEncodeError: 'charmap' codec can't encode - character maps to <undefined>, print function

Based on Dirk Stöcker's answer, here's a neat wrapper function for Python 3's print function. Use it just like you would use print.

As an added bonus, compared to the other answers, this won't print your text as a bytearray ('b"content"'), but as normal strings ('content'), because of the last decode step.

def uprint(*objects, sep=' ', end='\n', file=sys.stdout):
    enc = file.encoding
    if enc == 'UTF-8':
        print(*objects, sep=sep, end=end, file=file)
    else:
        f = lambda obj: str(obj).encode(enc, errors='backslashreplace').decode(enc)
        print(*map(f, objects), sep=sep, end=end, file=file)

uprint('foo')
uprint(u'Antonín Dvorák')
uprint('foo', 'bar', u'Antonín Dvorák')

How to recompile with -fPIC

Briefly, the error means that you can't use a static library to be linked w/ a dynamic one. The correct way is to have a libavcodec compiled into a .so instead of .a, so the other .so library you are trying to build will link well.

The shortest way to do so is to add --enable-shared at ./configure options. Or even you may try to disable shared (or static) libraries at all... you choose what is suitable for you!

How to increase IDE memory limit in IntelliJ IDEA on Mac?

I use Mac and Idea 14.1.7. Found idea.vmoptions file here: /Applications/IntelliJ IDEA 14.app/Contents/bin

details

Matplotlib-Animation "No MovieWriters Available"

(be sure to follow JPH feedback above about the proper ffmpeg download) Not sure why, but in my case here is the one that worked (in my case was on windows).

Initialize a writer:

import matplotlib.pyplot as plt
import matplotlib.animation as animation
Writer = animation.FFMpegWriter(fps=30, codec='libx264')  #or 
Writer = animation.FFMpegWriter(fps=20, metadata=dict(artist='Me'), bitrate=1800) ==> This is WORKED FINE ^_^

Writer = animation.writers['ffmpeg'] ==> GIVES ERROR ""RuntimeError: Requested MovieWriter (ffmpeg) not available""

Encoding as Base64 in Java

Google Guava is another choice to encode and decode Base64 data:

POM configuration:

<dependency>
   <artifactId>guava</artifactId>
   <groupId>com.google.guava</groupId>
   <type>jar</type>
   <version>14.0.1</version>
</dependency>

Sample code:

String inputContent = "Hello Vi?t Nam";
String base64String = BaseEncoding.base64().encode(inputContent.getBytes("UTF-8"));

// Decode
System.out.println("Base64:" + base64String); // SGVsbG8gVmnhu4d0IE5hbQ==
byte[] contentInBytes = BaseEncoding.base64().decode(base64String);
System.out.println("Source content: " + new String(contentInBytes, "UTF-8")); // Hello Vi?t Nam

Execute jar file with multiple classpath libraries from command prompt

I was running into the same issue but was able to package all dependencies into my jar file using the Maven Shade Plugin

Visual Studio debugging/loading very slow

There is also complications in partial views where there is an error on the page that is not recognized immediately. Like Model.SomeValue instead of Model.ThisValue. It might not underline and cause problems in debugging. This can be a real pain to catch.

UnicodeDecodeError: 'utf8' codec can't decode byte 0x9c

This type of issue crops up for me now that I've moved to Python 3. I had no idea Python 2 was simply steam rolling any issues with file encoding.

I found this nice explanation of the differences and how to find a solution after none of the above worked for me.

http://python-notes.curiousefficiency.org/en/latest/python3/text_file_processing.html

In short, to make Python 3 behave as similarly as possible to Python 2 use:

with open(filename, encoding="latin-1") as datafile:
    # work on datafile here

However, read the article, there is no one size fits all solution.

Printing to the console in Google Apps Script?

Even though Logger.log() is technically the correct way to output something to the console, it has a few annoyances:

  1. The output can be an unstructured mess and hard to quickly digest.
  2. You have to first run the script, then click View / Logs, which is two extra clicks (one if you remember the Ctrl+Enter keyboard shortcut).
  3. You have to insert Logger.log(playerArray), and then after debugging you'd probably want to remove Logger.log(playerArray), hence an additional 1-2 more steps.
  4. You have to click on OK to close the overlay (yet another extra click).

Instead, whenever I want to debug something I add breakpoints (click on line number) and press the Debug button (bug icon). Breakpoints work well when you are assigning something to a variable, but not so well when you are initiating a variable and want to peek inside of it at a later point, which is similar to what the op is trying to do. In this case, I would force a break condition by entering "x" (x marks the spot!) to throw a run-time error:

enter image description here

Compare with viewing Logs:

enter image description here

The Debug console contains more information and is a lot easier to read than the Logs overlay. One minor benefit with this method is that you never have to worry about polluting your code with a bunch of logging commands if keeping clean code is your thing. Even if you enter "x", you are forced to remember to remove it as part of the debugging process or else your code won't run (built-in cleanup measure, yay).

JavaScript: function returning an object

I would take those directions to mean:

  function makeGamePlayer(name,totalScore,gamesPlayed) {
        //should return an object with three keys:
        // name
        // totalScore
        // gamesPlayed

         var obj = {  //note you don't use = in an object definition
             "name": name,
             "totalScore": totalScore,
             "gamesPlayed": gamesPlayed
          }
         return obj;
    }

The module was expected to contain an assembly manifest

I found that, I am using a different InstallUtil from my target .NET Framework. I am building a .NET Framework 4.5, meanwhile the error occured if I am using the .NET Framework 2.0 release. Having use the right InstallUtil for my target .NET Framework, solved this problem!

How to make Sonar ignore some classes for codeCoverage metric?

Sometimes, Clover is configured to provide code coverage reports for all non-test code. If you wish to override these preferences, you may use configuration elements to exclude and include source files from being instrumented:

<plugin>
    <groupId>com.atlassian.maven.plugins</groupId>
    <artifactId>maven-clover2-plugin</artifactId>
    <version>${clover-version}</version>
    <configuration> 
        <excludes> 
            <exclude>**/*Dull.java</exclude> 
        </excludes> 
    </configuration>
</plugin>

Also, you can include the following Sonar configuration:

<properties>
    <sonar.exclusions>
        **/domain/*.java,
        **/transfer/*.java
    </sonar.exclusions>
</properties> 

ffmpeg - Converting MOV files to MP4

The command to just stream it to a new container (mp4) needed by some applications like Adobe Premiere Pro without encoding (fast) is:

ffmpeg -i input.mov -qscale 0 output.mp4

Alternative as mentioned in the comments, which re-encodes with best quaility (-qscale 0):

ffmpeg -i input.mov -q:v 0 output.mp4

How to add a new audio (not mixing) into a video using ffmpeg?

If you are using an old version of FFMPEG and you cant upgrade you can do the following:

ffmpeg -i PATH/VIDEO_FILE_NAME.mp4 -i PATH/AUDIO_FILE_NAME.mp3 -vcodec copy -shortest DESTINATION_PATH/NEW_VIDEO_FILE_NAME.mp4

Notice that I used -vcodec

Decoding a Base64 string in Java

If you don't want to use apache, you can use Java8:

byte[] decodedBytes = Base64.getDecoder().decode("YWJjZGVmZw=="); 
System.out.println(new String(decodedBytes) + "\n");

how to create insert new nodes in JsonNode?

I've recently found even more interesting way to create any ValueNode or ContainerNode (Jackson v2.3).

ObjectNode node = JsonNodeFactory.instance.objectNode();

Setting Camera Parameters in OpenCV/Python

I wasn't able to fix the problem OpenCV either, but a video4linux (V4L2) workaround does work with OpenCV when using Linux. At least, it does on my Raspberry Pi with Rasbian and my cheap webcam. This is not as solid, light and portable as you'd like it to be, but for some situations it might be very useful nevertheless.

Make sure you have the v4l2-ctl application installed, e.g. from the Debian v4l-utils package. Than run (before running the python application, or from within) the command:

v4l2-ctl -d /dev/video1 -c exposure_auto=1 -c exposure_auto_priority=0 -c exposure_absolute=10

It overwrites your camera shutter time to manual settings and changes the shutter time (in ms?) with the last parameter to (in this example) 10. The lower this value, the darker the image.

string encoding and decoding?

Guessing at all the things omitted from the original question, but, assuming Python 2.x the key is to read the error messages carefully: in particular where you call 'encode' but the message says 'decode' and vice versa, but also the types of the values included in the messages.

In the first example string is of type unicode and you attempted to decode it which is an operation converting a byte string to unicode. Python helpfully attempted to convert the unicode value to str using the default 'ascii' encoding but since your string contained a non-ascii character you got the error which says that Python was unable to encode a unicode value. Here's an example which shows the type of the input string:

>>> u"\xa0".decode("ascii", "ignore")

Traceback (most recent call last):
  File "<pyshell#7>", line 1, in <module>
    u"\xa0".decode("ascii", "ignore")
UnicodeEncodeError: 'ascii' codec can't encode character u'\xa0' in position 0: ordinal not in range(128)

In the second case you do the reverse attempting to encode a byte string. Encoding is an operation that converts unicode to a byte string so Python helpfully attempts to convert your byte string to unicode first and, since you didn't give it an ascii string the default ascii decoder fails:

>>> "\xc2".encode("ascii", "ignore")

Traceback (most recent call last):
  File "<pyshell#6>", line 1, in <module>
    "\xc2".encode("ascii", "ignore")
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2 in position 0: ordinal not in range(128)

UnicodeDecodeError: 'ascii' codec can't decode byte 0xef in position 1

This is to do with the encoding of your terminal not being set to UTF-8. Here is my terminal

$ echo $LANG
en_GB.UTF-8
$ python
Python 2.7.3 (default, Apr 20 2012, 22:39:59) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> s = '(\xef\xbd\xa1\xef\xbd\xa5\xcf\x89\xef\xbd\xa5\xef\xbd\xa1)\xef\xbe\x89'
>>> s1 = s.decode('utf-8')
>>> print s1
(?????)?
>>> 

On my terminal the example works with the above, but if I get rid of the LANG setting then it won't work

$ unset LANG
$ python
Python 2.7.3 (default, Apr 20 2012, 22:39:59) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> s = '(\xef\xbd\xa1\xef\xbd\xa5\xcf\x89\xef\xbd\xa5\xef\xbd\xa1)\xef\xbe\x89'
>>> s1 = s.decode('utf-8')
>>> print s1
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeEncodeError: 'ascii' codec can't encode characters in position 1-5: ordinal not in range(128)
>>> 

Consult the docs for your linux variant to discover how to make this change permanent.

What is the difference between H.264 video and MPEG-4 video?

They are names for the same standard from two different industries with different naming methods, the guys who make & sell movies and the guys who transfer the movies over the internet. Since 2003: "MPEG 4 Part 10" = "H.264" = "AVC". Before that the relationship was a little looser in that they are not equal but an "MPEG 4 Part 2" decoder can render a stream that's "H.263". The Next standard is "MPEG H Part 2" = "H.265" = "HEVC"

UnicodeDecodeError: 'ascii' codec can't decode byte 0xd1 in position 2: ordinal not in range(128)

if you get this issue while running certbot while creating or renewing certificate, Please use the following method

grep -r -P '[^\x00-\x7f]' /etc/apache2 /etc/letsencrypt /etc/nginx

That command found the offending character "´" in one .conf file in the comment. After removing it (you can edit comments as you wish) and reloading nginx, everything worked again.

Source :https://github.com/certbot/certbot/issues/5236

Usage of unicode() and encode() functions in Python

Make sure you've set your locale settings right before running the script from the shell, e.g.

$ locale -a | grep "^en_.\+UTF-8"
en_GB.UTF-8
en_US.UTF-8
$ export LC_ALL=en_GB.UTF-8
$ export LANG=en_GB.UTF-8

Docs: man locale, man setlocale.

How to play a notification sound on websites?

Play cross browser compatible notifications

As adviced by @Tim Tisdall from this post , Check Howler.js Plugin.

Browsers like chrome disables javascript execution when minimized or inactive for performance improvements. But This plays notification sounds even if browser is inactive or minimized by the user.

  var sound =new Howl({
                     src: ['../sounds/rings.mp3','../sounds/rings.wav','../sounds/rings.ogg',
                           '../sounds/rings.aiff'],
                     autoplay: true,
                     loop: true
                    });

               sound.play();

Hope helps someone.

UnicodeEncodeError: 'ascii' codec can't encode character u'\xa0' in position 20: ordinal not in range(128)

I just used the following:

import unicodedata
message = unicodedata.normalize("NFKD", message)

Check what documentation says about it:

unicodedata.normalize(form, unistr) Return the normal form form for the Unicode string unistr. Valid values for form are ‘NFC’, ‘NFKC’, ‘NFD’, and ‘NFKD’.

The Unicode standard defines various normalization forms of a Unicode string, based on the definition of canonical equivalence and compatibility equivalence. In Unicode, several characters can be expressed in various way. For example, the character U+00C7 (LATIN CAPITAL LETTER C WITH CEDILLA) can also be expressed as the sequence U+0043 (LATIN CAPITAL LETTER C) U+0327 (COMBINING CEDILLA).

For each character, there are two normal forms: normal form C and normal form D. Normal form D (NFD) is also known as canonical decomposition, and translates each character into its decomposed form. Normal form C (NFC) first applies a canonical decomposition, then composes pre-combined characters again.

In addition to these two forms, there are two additional normal forms based on compatibility equivalence. In Unicode, certain characters are supported which normally would be unified with other characters. For example, U+2160 (ROMAN NUMERAL ONE) is really the same thing as U+0049 (LATIN CAPITAL LETTER I). However, it is supported in Unicode for compatibility with existing character sets (e.g. gb2312).

The normal form KD (NFKD) will apply the compatibility decomposition, i.e. replace all compatibility characters with their equivalents. The normal form KC (NFKC) first applies the compatibility decomposition, followed by the canonical composition.

Even if two unicode strings are normalized and look the same to a human reader, if one has combining characters and the other doesn’t, they may not compare equal.

Solves it for me. Simple and easy.

How can I extract audio from video with ffmpeg?

ffmpeg -i sample.avi will give you the audio/video format info for your file. Make sure you have the proper libraries configured to parse the input streams. Also, make sure that the file isn't corrupt.

Python - 'ascii' codec can't decode byte

"??".encode('utf-8')

encode converts a unicode object to a string object. But here you have invoked it on a string object (because you don't have the u). So python has to convert the string to a unicode object first. So it does the equivalent of

"??".decode().encode('utf-8')

But the decode fails because the string isn't valid ascii. That's why you get a complaint about not being able to decode.

UnicodeDecodeError: 'charmap' codec can't decode byte X in position Y: character maps to <undefined>

As an extension to @LennartRegebro's answer:

If you can't tell what encoding your file uses and the solution above does not work (it's not utf8) and you found yourself merely guessing - there are online tools that you could use to identify what encoding that is. They aren't perfect but usually work just fine. After you figure out the encoding you should be able to use solution above.

EDIT: (Copied from comment)

A quite popular text editor Sublime Text has a command to display encoding if it has been set...

  1. Go to View -> Show Console (or Ctrl+`)

enter image description here

  1. Type into field at the bottom view.encoding() and hope for the best (I was unable to get anything but Undefined but maybe you will have better luck...)

enter image description here

How to autoplay HTML5 mp4 video on Android?

Autoplay only works the second time through. on android 4.1+ you have to have some kind of user event to get the first play() to work. Once that has happened then autostart works.

This is so that the user is acknowledging that they are using bandwidth.

There is another question that answers this . Autostart html5 video using android 4 browser

Convert UTF-8 with BOM to UTF-8 with no BOM in Python

In Python 3 it's quite easy: read the file and rewrite it with utf-8 encoding:

s = open(bom_file, mode='r', encoding='utf-8-sig').read()
open(bom_file, mode='w', encoding='utf-8').write(s)

Use ffmpeg to add text subtitles

You are trying to mux subtitles as a subtitle stream. It is easy but different syntax is used for MP4 (or M4V) and MKV. In both cases you must specify video and audio codec, or just copy stream if you just want to add subtitle.

MP4:

ffmpeg -i input.mp4 -f srt -i input.srt \
-map 0:0 -map 0:1 -map 1:0 -c:v copy -c:a copy \
-c:s mov_text output.mp4

MKV:

ffmpeg -i input.mp4 -f srt -i input.srt \
-map 0:0 -map 0:1 -map 1:0 -c:v copy -c:a copy \
-c:s srt  output.mkv

How can I give the Intellij compiler more heap space?

I was facing "java.lang.OutOfMemoryError: Java heap space" error while building my project using maven install command.

I was able to get rid of it by changing maven runner settings.

Settings | Build, Execution, Deployment | Build Tools | Maven | Runner | VM options to -Xmx512m

How to concatenate two MP4 files using FFmpeg?

FFmpeg has three concatenation methods:

1. concat video filter

Use this method if your inputs do not have the same parameters (width, height, etc), or are not the same formats/codecs, or if you want to perform any filtering.

Note that this method performs a re-encode of all inputs. If you want to avoid the re-encode, you could re-encode just the inputs that don't match so they share the same codec and other parameters, then use the concat demuxer to avoid re-encoding everything.

ffmpeg -i opening.mkv -i episode.mkv -i ending.mkv \
       -filter_complex "[0:v] [0:a] [1:v] [1:a] [2:v] [2:a] 
                        concat=n=3:v=1:a=1 [v] [a]" \
       -map "[v]" -map "[a]" output.mkv

2. concat demuxer

Use this method when you want to avoid a re-encode and your format does not support file-level concatenation (most files used by general users do not support file-level concatenation).

$ cat mylist.txt
file '/path/to/file1'
file '/path/to/file2'
file '/path/to/file3'
    
$ ffmpeg -f concat -safe 0 -i mylist.txt -c copy output.mp4

For Windows:

(echo file 'first file.mp4' & echo file 'second file.mp4' )>list.txt
ffmpeg -safe 0 -f concat -i list.txt -c copy output.mp4

3. concat protocol

Use this method with formats that support file-level concatenation (MPEG-1, MPEG-2 PS, DV). Do not use with MP4.

ffmpeg -i "concat:input1|input2" -codec copy output.mkv

This method does not work for many formats, including MP4, due to the nature of these formats and the simplistic concatenation performed by this method.


If in doubt about which method to use, try the concat demuxer.

Also see

What's the correct way to convert bytes to a hex string in Python 3?

it can been used the format specifier %x02 that format and output a hex value. For example:

>>> foo = b"tC\xfc}\x05i\x8d\x86\x05\xa5\xb4\xd3]Vd\x9cZ\x92~'6"
>>> res = ""
>>> for b in foo:
...     res += "%02x" % b
... 
>>> print(res)
7443fc7d05698d8605a5b4d35d56649c5a927e2736

Python: Converting from ISO-8859-1/latin1 to UTF-8

Try decoding it first, then encoding:

apple.decode('iso-8859-1').encode('utf8')

UnicodeDecodeError: 'utf8' codec can't decode bytes in position 3-6: invalid data

The solution to change the encoding to Latin1 / ISO-8859-1 solves an issue I observed with html2text.py as invoked on an output of tex4ht. I use that for an automated word count on LaTeX documents: tex4ht converts them to HTML, and then html2text.py strips them down to pure text for further counting through wc -w. Now, if, for example, a German "Umlaut" comes in through a literature database entry, that process would fail as html2text.py would complain e.g.

UnicodeDecodeError: 'utf8' codec can't decode bytes in position 32243-32245: invalid data

Now these errors would then subsequently be particularly hard to track down, and essentially you want to have the Umlaut in your references section. A simple change inside html2text.py from

data = data.decode(encoding)

to

data = data.decode("ISO-8859-1")

solves that issue; if you're calling the script using the HTML file as first parameter, you can also pass the encoding as second parameter and spare the modification.

Maven2: Missing artifact but jars are in place

I used the below code in pom.xml to download the jar

<dependency>
            <groupId>javax.validation</groupId>
            <artifactId>validation-api</artifactId>
            <version>1.1.0.FINAL</version>
</dependency>

But in the .m2 folder under validation folder...the jar didnt get downloaded. I am not sure about the issue. But i downloaded the same jar from maven official website and placed in the .m2 folder under respective folder and cleaned the project. The error gone and it started working now.

Writing Unicode text to a text file?

Unicode string handling is already standardized in Python 3.

  1. char's are already stored in Unicode (32-bit) in memory
  2. You only need to open file in utf-8
    (32-bit Unicode to variable-byte-length utf-8 conversion is automatically performed from memory to file.)

    out1 = "(???? ??? ??´ ??` ???` )"
    fobj = open("t1.txt", "w", encoding="utf-8")
    fobj.write(out1)
    fobj.close()
    

HTML5 live streaming

Firstly you need to setup a media streaming server. You can use Wowza, red5 or nginx-rtmp-module. Read their documentation and setup on OS you want. All the engine are support HLS (Http Live Stream protocol that was developed by Apple). You should read documentation for config. Example with nginx-rtmp-module:

rtmp {
    server {
        listen 1935; # Listen on standard RTMP port
        chunk_size 4000;

        application show {
            live on;
            # Turn on HLS
            hls on;
            hls_path /mnt/hls/;
            hls_fragment 3;
            hls_playlist_length 60;
            # disable consuming the stream from nginx as rtmp
            deny play all;
        }
    }
} 

server {
    listen 8080;

    location /hls {
        # Disable cache
        add_header Cache-Control no-cache;

        # CORS setup
        add_header 'Access-Control-Allow-Origin' '*' always;
        add_header 'Access-Control-Expose-Headers' 'Content-Length,Content-Range';
        add_header 'Access-Control-Allow-Headers' 'Range';

        # allow CORS preflight requests
        if ($request_method = 'OPTIONS') {
            add_header 'Access-Control-Allow-Origin' '*';
            add_header 'Access-Control-Allow-Headers' 'Range';
            add_header 'Access-Control-Max-Age' 1728000;
            add_header 'Content-Type' 'text/plain charset=UTF-8';
            add_header 'Content-Length' 0;
            return 204;
        }

        types {
            application/vnd.apple.mpegurl m3u8;
            video/mp2t ts;
        }

        root /mnt/;
    }
}

After server was setup and configuration successful. you must use some rtmp encoder software (OBS, wirecast ...) for start streaming like youtube or twitchtv.

In client side (browser in your case) you can use Videojs or JWplayer to play video for end user. You can do something like below for Videojs:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Live Streaming</title>
    <link href="//vjs.zencdn.net/5.8/video-js.min.css" rel="stylesheet">
    <script src="//vjs.zencdn.net/5.8/video.min.js"></script>
</head>
<body>
<video id="player" class="video-js vjs-default-skin" height="360" width="640" controls preload="none">
    <source src="http://localhost:8080/hls/stream.m3u8" type="application/x-mpegURL" />
</video>
<script>
    var player = videojs('#player');
</script>
</body>
</html>

You don't need to add others plugin like flash (because we use HLS not rtmp). This player can work well cross browser with out flash.

Py_Initialize fails - unable to load the file system codec

In my cases, for windows, if you have multiple python versions installed, if PYTHONPATH is pointing to one version the other ones didn't work. I found that if you just remove PYTHONPATH, they all work fine

ffmpeg usage to encode a video to H264 codec format

I believe you have libx264 installed and configured with ffmpeg to convert video to h264... Then you can try with -vcodec libx264... The -format option is for showing available formats, this is not a conversion option I think...

FFmpeg: How to split video efficiently?

In my experience, don't use ffmpeg for splitting/join. MP4Box, is faster and light than ffmpeg. Please tryit. Eg if you want to split a 1400mb MP4 file into two parts a 700mb you can use the following cmdl: MP4Box -splits 716800 input.mp4 eg for concatenating two files you can use:

MP4Box -cat file1.mp4 -cat file2.mp4 output.mp4

Or if you need split by time, use -splitx StartTime:EndTime:

MP4Box -add input.mp4 -splitx 0:15 -new split.mp4

UnicodeDecodeError, invalid continuation byte

In binary, 0xE9 looks like 1110 1001. If you read about UTF-8 on Wikipedia, you’ll see that such a byte must be followed by two of the form 10xx xxxx. So, for example:

>>> b'\xe9\x80\x80'.decode('utf-8')
u'\u9000'

But that’s just the mechanical cause of the exception. In this case, you have a string that is almost certainly encoded in latin 1. You can see how UTF-8 and latin 1 look different:

>>> u'\xe9'.encode('utf-8')
b'\xc3\xa9'
>>> u'\xe9'.encode('latin-1')
b'\xe9'

(Note, I'm using a mix of Python 2 and 3 representation here. The input is valid in any version of Python, but your Python interpreter is unlikely to actually show both unicode and byte strings in this way.)

fatal: git-write-tree: error building trees

This worked for me:

Do

$ git status

And check if you have Unmerged paths

# Unmerged paths:
#   (use "git reset HEAD <file>..." to unstage)
#   (use "git add <file>..." to mark resolution)
#
#   both modified:      app/assets/images/logo.png
#   both modified:      app/models/laundry.rb

Fix them with git add to each of them and try git stash again.

git add app/assets/images/logo.png

UnicodeEncodeError: 'ascii' codec can't encode character u'\u2013' in position 3 2: ordinal not in range(128)

I had the same problem. This work fine for me:

str(objdata).encode('utf-8')

UnicodeEncodeError: 'ascii' codec can't encode character u'\xef' in position 0: ordinal not in range(128)

An easy solution to overcome this problem is to set your default encoding to utf8. Follow is an example

import sys

reload(sys)
sys.setdefaultencoding('utf8')

C++ error: "Array must be initialized with a brace enclosed initializer"

The syntax to statically initialize an array uses curly braces, like this:

int array[10] = { 0 };

This will zero-initialize the array.

For multi-dimensional arrays, you need nested curly braces, like this:

int cipher[Array_size][Array_size]= { { 0 } };

Note that Array_size must be a compile-time constant for this to work. If Array_size is not known at compile-time, you must use dynamic initialization. (Preferably, an std::vector).

Python script to convert from UTF-8 to ASCII

data="UTF-8 DATA"
udata=data.decode("utf-8")
asciidata=udata.encode("ascii","ignore")

UnicodeEncodeError: 'latin-1' codec can't encode character

I ran into this same issue when using the Python MySQLdb module. Since MySQL will let you store just about any binary data you want in a text field regardless of character set, I found my solution here:

Using UTF8 with Python MySQLdb

Edit: Quote from the above URL to satisfy the request in the first comment...

"UnicodeEncodeError:'latin-1' codec can't encode character ..."

This is because MySQLdb normally tries to encode everythin to latin-1. This can be fixed by executing the following commands right after you've etablished the connection:

db.set_character_set('utf8')
dbc.execute('SET NAMES utf8;')
dbc.execute('SET CHARACTER SET utf8;')
dbc.execute('SET character_set_connection=utf8;')

"db" is the result of MySQLdb.connect(), and "dbc" is the result of db.cursor().

How to parse a JSON string into JsonNode in Jackson?

New approach to old question. A solution that works from java 9+

ObjectNode agencyNode = new ObjectMapper().valueToTree(Map.of("key", "value"));

is more readable and maintainable for complex objects. Ej

Map<String, Object> agencyMap = Map.of(
        "name", "Agencia Prueba",
        "phone1", "1198788373",
        "address", "Larrea 45 e/ calligaris y paris",
        "number", 267,
        "enable", true,
        "location", Map.of("id", 54),
        "responsible", Set.of(Map.of("id", 405)),
        "sellers", List.of(Map.of("id", 605))
);
ObjectNode agencyNode = new ObjectMapper().valueToTree(agencyMap);

What are all codecs and formats supported by FFmpeg?

You can see the list of supported codecs in the official documentation:

Supported video codecs

Supported audio codecs

A connection was successfully established with the server, but then an error occurred during the pre-login handshake

I experienced this error when running some very memory-expensive processes. When the system started to run short of memory, I begun to notice this kind of error. I had to change the algorithm in order to make a better use of RAM.

To be noted that while some threads threw this exception, some other threw:

System.Data.SqlClient.SqlException (0x80131904): Connection Timeout Expired. The timeout period elapsed while attempting to consume the pre-login handshake acknowledgement. This could be because the pre-login handshake failed or the server was unable to respond back in time. The duration spent while attempting to connect to this server was - [Pre-Login] initialization=43606; handshake=560; ---> System.ComponentModel.Win32Exception (0x80004005): The wait operation timed out

Both problems disappeared after the system was changed so that it could run using less RAM.

process.start() arguments

Try fully qualifying the filenames in the arguments - I notice you're specifying the path in the FileName part, so it's possible that the process is being started elsewhere, then not finding the arguments and causing an error.

If that works, then setting the WorkingDirectory property on the StartInfo may be of use.

Actually, according to the link

The WorkingDirectory property must be set if UserName and Password are provided. If the property is not set, the default working directory is %SYSTEMROOT%\system32.

Convert audio files to mp3 using ffmpeg

https://trac.ffmpeg.org/wiki/Encode/MP3

VBR Encoding:

ffmpeg -vn -ar 44100 -ac 2 -q:a 1 -codec:a libmp3lame output.mp3

Python Unicode Encode Error

Don't hardcode the character encoding of your environment inside your script; print Unicode text directly instead:

assert isinstance(text, unicode) # or str on Python 3
print(text)

If your output is redirected to a file (or a pipe); you could use PYTHONIOENCODING envvar, to specify the character encoding:

$ PYTHONIOENCODING=utf-8 python your_script.py >output.utf8

Otherwise, python your_script.py should work as is -- your locale settings are used to encode the text (on POSIX check: LC_ALL, LC_CTYPE, LANG envvars -- set LANG to a utf-8 locale if necessary).

To print Unicode on Windows, see this answer that shows how to print Unicode to Windows console, to a file, or using IDLE.

Python "string_escape" vs "unicode_escape"

According to my interpretation of the implementation of unicode-escape and the unicode repr in the CPython 2.6.5 source, yes; the only difference between repr(unicode_string) and unicode_string.encode('unicode-escape') is the inclusion of wrapping quotes and escaping whichever quote was used.

They are both driven by the same function, unicodeescape_string. This function takes a parameter whose sole function is to toggle the addition of the wrapping quotes and escaping of that quote.

Return multiple values in JavaScript?

Other than returning an array or an object as others have recommended, you can also use a collector function (similar to the one found in The Little Schemer):

function a(collector){
  collector(12,13);
}

var x,y;
a(function(a,b){
  x=a;
  y=b;
});

I made a jsperf test to see which one of the three methods is faster. Array is fastest and collector is slowest.

http://jsperf.com/returning-multiple-values-2

HTML5 video (mp4 and ogv) problems in Safari and Firefox - but Chrome is all good

Add these lines in your .htaccess file and it will work for all browsers. Works for me.

AddType video/ogg .ogv
AddType video/mp4 .mp4
AddType video/webm .webm

If you dun have .htaccess file in your site then create new one :) its obvious i guess.

Using FFmpeg in .net?

The original question is now more than 5 years old. In the meantime there is now a solution for a WinRT solution from ffmpeg and an integration sample from Microsoft.

Convert Unicode to ASCII without errors in Python

>>> u'a?ä'.encode('ascii', 'ignore')
'a'

Decode the string you get back, using either the charset in the the appropriate meta tag in the response or in the Content-Type header, then encode.

The method encode(encoding, errors) accepts custom handlers for errors. The default values, besides ignore, are:

>>> u'a?ä'.encode('ascii', 'replace')
b'a??'
>>> u'a?ä'.encode('ascii', 'xmlcharrefreplace')
b'a&#12354;&#228;'
>>> u'a?ä'.encode('ascii', 'backslashreplace')
b'a\\u3042\\xe4'

See https://docs.python.org/3/library/stdtypes.html#str.encode

c# Image resizing to different size while preserving aspect ratio

I created a extension method that is much simpiler than the answers that are posted. and the aspect ratio is applied without cropping the image.

public static Image Resize(this Image image, int width, int height) {
     var scale = Math.Min(height / (float)image.Height, width / (float)image.Width);
     return image.GetThumbnailImage((int)(image.Width * scale), (int)(image.Height * scale), () => false, IntPtr.Zero);
}

Example usage:

using (var img = Image.FromFile(pathToOriginalImage)) {
    using (var thumbnail = img.Resize(60, 60)){
        // Here you can do whatever you need to do with thumnail
    }
}

Convert a video to MP4 (H.264/AAC) with ffmpeg

You need to recompile ffmpeg (from source) so that it supports x264. If you follow the instructions in this page, then you will be able to peform any kind of conversion you want.

How can I make a multipart/form-data POST request using Java?

We have a pure java implementation of multipart-form submit without using any external dependencies or libraries outside jdk. Refer https://github.com/atulsm/https-multipart-purejava/blob/master/src/main/java/com/atul/MultipartPure.java

private static String body = "{\"key1\":\"val1\", \"key2\":\"val2\"}";
private static String subdata1 = "@@ -2,3 +2,4 @@\r\n";
private static String subdata2 = "<data>subdata2</data>";

public static void main(String[] args) throws Exception{        
    String url = "https://" + ip + ":" + port + "/dataupload";
    String token = "Basic "+ Base64.getEncoder().encodeToString((userName+":"+password).getBytes());

    MultipartBuilder multipart = new MultipartBuilder(url,token);       
    multipart.addFormField("entity", "main", "application/json",body);
    multipart.addFormField("attachment", "subdata1", "application/octet-stream",subdata1);
    multipart.addFormField("attachment", "subdata2", "application/octet-stream",subdata2);        
    List<String> response = multipart.finish();         
    for (String line : response) {
        System.out.println(line);
    }
}

Qt jpg image display

You could attach the image (as a pixmap) to a label then add that to your layout...

...

QPixmap image("blah.jpg");

QLabel *imageLabel = new QLabel();
imageLabel->setPixmap(image);

mainLayout.addWidget(imageLabel);

...

Apologies, this is using Jambi (Qt for Java) so the syntax is different, but the theory is the same.

"Unicode Error "unicodeescape" codec can't decode bytes... Cannot open text files in Python 3

I had this error. I have a main python script which calls in functions from another, 2nd, python script. At the end of the first script I had a comment block designated with ''' '''. I was getting this error because of this commenting code block. I repeated the error multiple times once I found it to ensure this was the error, & it was. I am still unsure why.

A generic error occurred in GDI+, JPEG Image to MemoryStream

OK I seem to have found the cause just by sheer luck and its nothing wrong with that particular method, it's further back up the call stack.

Earlier I resize the image and as part of that method I return the resized object as follows. I have inserted two calls to the above method and a direct save to a file.

// At this point the new bitmap has no MimeType
// Need to output to memory stream
using (var m = new MemoryStream())
{
       dst.Save(m, format);

       var img = Image.FromStream(m);

       //TEST
       img.Save("C:\\test.jpg");
       var bytes = PhotoEditor.ConvertImageToByteArray(img);


       return img;
 }

It appears that the memory stream that the object was created on has to be open at the time the object is saved. I am not sure why this is. Is anyone able to enlighten me and how I can get around this.

I only return from a stream because after using the resize code similar to this the destination file has an unknown mime type (img.RawFormat.Guid) and Id like the Mime type to be correct on all image objects as it makes it hard write generic handling code otherwise.

EDIT

This didn't come up in my initial search but here's the answer from Jon Skeet

Write to UTF-8 file in Python

@S-Lott gives the right procedure, but expanding on the Unicode issues, the Python interpreter can provide more insights.

Jon Skeet is right (unusual) about the codecs module - it contains byte strings:

>>> import codecs
>>> codecs.BOM
'\xff\xfe'
>>> codecs.BOM_UTF8
'\xef\xbb\xbf'
>>> 

Picking another nit, the BOM has a standard Unicode name, and it can be entered as:

>>> bom= u"\N{ZERO WIDTH NO-BREAK SPACE}"
>>> bom
u'\ufeff'

It is also accessible via unicodedata:

>>> import unicodedata
>>> unicodedata.lookup('ZERO WIDTH NO-BREAK SPACE')
u'\ufeff'
>>> 

Reading a UTF8 CSV file with Python

Python 2.X

There is a unicode-csv library which should solve your problems, with added benefit of not naving to write any new csv-related code.

Here is a example from their readme:

>>> import unicodecsv
>>> from cStringIO import StringIO
>>> f = StringIO()
>>> w = unicodecsv.writer(f, encoding='utf-8')
>>> w.writerow((u'é', u'ñ'))
>>> f.seek(0)
>>> r = unicodecsv.reader(f, encoding='utf-8')
>>> row = r.next()
>>> print row[0], row[1]
é ñ

Python 3.X

In python 3 this is supported out of the box by the build-in csv module. See this example:

import csv
with open('some.csv', newline='', encoding='utf-8') as f:
    reader = csv.reader(f)
    for row in reader:
        print(row)

How to create a thread?

public class ThreadParameter
        {
            public int Port { get; set; }
            public string Path { get; set; }
        }


Thread t = new Thread(new ParameterizedThreadStart(Startup));
t.Start(new ThreadParameter() { Port = port, Path = path});

Create an object with the port and path objects and pass it to the Startup method.

Converting from a string to boolean in Python?

Yet another option

from ansible.module_utils.parsing.convert_bool import boolean
boolean('no')
# False
boolean('yEs')
# True
boolean('true')
# True

How to get image height and width using java?

To get size of emf file without EMF Image Reader you can use code:

Dimension getImageDimForEmf(final String path) throws IOException {

    ImageInputStream inputStream = new FileImageInputStream(new File(path));

    inputStream.setByteOrder(ByteOrder.LITTLE_ENDIAN);

    // Skip magic number and file size
    inputStream.skipBytes(6*4);

    int left   = inputStream.readInt();
    int top    = inputStream.readInt();
    int right  = inputStream.readInt();
    int bottom = inputStream.readInt();

    // Skip other headers
    inputStream.skipBytes(30);

    int deviceSizeInPixelX = inputStream.readInt();
    int deviceSizeInPixelY = inputStream.readInt();

    int deviceSizeInMlmX = inputStream.readInt();
    int deviceSizeInMlmY = inputStream.readInt();

    int widthInPixel = (int) Math.round(0.5 + ((right - left + 1.0) * deviceSizeInPixelX / deviceSizeInMlmX) / 100.0);
    int heightInPixel = (int) Math.round(0.5 + ((bottom-top + 1.0) * deviceSizeInPixelY / deviceSizeInMlmY) / 100.0);

    inputStream.close();

    return new Dimension(widthInPixel, heightInPixel);
}

Setting the correct encoding when piping stdout in Python

I ran into this problem in a legacy application, and it was difficult to identify where what was printed. I helped myself with this hack:

# encoding_utf8.py
import codecs
import builtins


def print_utf8(text, **kwargs):
    print(str(text).encode('utf-8'), **kwargs)


def print_utf8(fn):
    def print_fn(*args, **kwargs):
        return fn(str(*args).encode('utf-8'), **kwargs)
    return print_fn


builtins.print = print_utf8(print)

On top of my script, test.py:

import encoding_utf8
string = 'Axwell ? Ingrosso'
print(string)

Note that this changes ALL calls to print to use an encoding, so your console will print this:

$ python test.py
b'Axwell \xce\x9b Ingrosso'

How do you embed binary data in XML?

You could encode the binary data using base64 and put it into a Base64 element; the below article is a pretty good one on the subject.

Handling Binary Data in XML Documents

Python, Unicode, and the Windows console

If you're not interested in getting a reliable representation of the bad character(s) you might use something like this (working with python >= 2.6, including 3.x):

from __future__ import print_function
import sys

def safeprint(s):
    try:
        print(s)
    except UnicodeEncodeError:
        if sys.version_info >= (3,):
            print(s.encode('utf8').decode(sys.stdout.encoding))
        else:
            print(s.encode('utf8'))

safeprint(u"\N{EM DASH}")

The bad character(s) in the string will be converted in a representation which is printable by the Windows console.

How to tell PowerShell to wait for each command to end before starting the next?

If you use Start-Process <path to exe> -NoNewWindow -Wait

You can also use the -PassThru option to echo output.

Remove all classes that begin with a certain string

I also use hyphen'-' and digits for class name. So my version include '\d-'

$('#a')[0].className = $('#a')[0].className.replace(/\bbg.\d-*?\b/g, '');

How to parse a date?

The problem is that you have a date formatted like this:

Thu Jun 18 20:56:02 EDT 2009

But are using a SimpleDateFormat that is:

yyyy-MM-dd

The two formats don't agree. You need to construct a SimpleDateFormat that matches the layout of the string you're trying to parse into a Date. Lining things up to make it easy to see, you want a SimpleDateFormat like this:

EEE MMM dd HH:mm:ss zzz yyyy
Thu Jun 18 20:56:02 EDT 2009

Check the JavaDoc page I linked to and see how the characters are used.

How to use the gecko executable with Selenium

It is important to remember that the driver(file) must have execution permission (linux chmod +x geckodriver).

To sum up:

  1. Download gecko driver
  2. Add execution permission
  3. Add system property:

    System.setProperty("webdriver.gecko.driver", "FILE PATH");

  4. Instantiate and use the class

    WebDriver driver = new FirefoxDriver();

  5. Do whatever you want

  6. Close the driver

    driver.close;

Can I use git diff on untracked files?

For one file:

git diff --no-index /dev/null new_file

For all new files:

for next in $( git ls-files --others --exclude-standard ) ; do git --no-pager diff --no-index /dev/null $next; done;

As alias:

alias gdnew="for next in \$( git ls-files --others --exclude-standard ) ; do git --no-pager diff --no-index /dev/null \$next; done;"

For all modified and new files combined as one command:

{ git --no-pager diff; gdnew }

How To Format A Block of Code Within a Presentation?

If you're using Visual Studio (this might work in Eclipse also, but I never tried) and you copy & paste into Microsoft Word (or any other microsoft product) it will paste the code in whatever color your IDE had. Then you just need to copy the text out of word and into your desired application and it will paste as rich text.

I've only seen this work across Visual Studio to other Microsoft products though so I don't know if it will be any help.

Unable to get spring boot to automatically create database schema

Did you try running it with:

spring.jpa.generate-ddl=true

and then

spring.jpa.hibernate.ddl-auto = create

By default the DDL execution (or validation) is deferred until the ApplicationContext has started. There is also a spring.jpa.generate-ddl flag, but it is not used if Hibernate autoconfig is active because the ddl-auto settings are more fine-grained.

see spring-boot-features

Convert Iterator to ArrayList

You can also use IteratorUtils from Apache commons-collections, although it doesn't support generics:

List list = IteratorUtils.toList(iterator);

How does an SSL certificate chain bundle work?

The original order is in fact backwards. Certs should be followed by the issuing cert until the last cert is issued by a known root per IETF's RFC 5246 Section 7.4.2

This is a sequence (chain) of certificates. The sender's certificate MUST come first in the list. Each following certificate MUST directly certify the one preceding it.

See also SSL: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch for troubleshooting techniques.

But I still don't know why they wrote the spec so that the order matters.

AJAX POST and Plus Sign ( + ) -- How to Encode?

Use encodeURIComponent() in JS and in PHP you should receive the correct values.

Note: When you access $_GET, $_POST or $_REQUEST in PHP, you are retrieving values that have already been decoded.

Example:

In your JS:

// url encode your string
var string = encodeURIComponent('+'); // "%2B"
// send it to your server
window.location = 'http://example.com/?string='+string; // http://example.com/?string=%2B

On your server:

echo $_GET['string']; // "+"

It is only the raw HTTP request that contains the url encoded data.

For a GET request you can retrieve this from the URI. $_SERVER['REQUEST_URI'] or $_SERVER['QUERY_STRING']. For a urlencoded POST, file_get_contents('php://stdin')

NB:

decode() only works for single byte encoded characters. It will not work for the full UTF-8 range.

eg:

text = "\u0100"; // A
// incorrect
escape(text); // %u0100 
// correct
encodeURIComponent(text); // "%C4%80"

Note: "%C4%80" is equivalent to: escape('\xc4\x80')

Which is the byte sequence (\xc4\x80) that represents A in UTF-8. So if you use encodeURIComponent() your server side must know that it is receiving UTF-8. Otherwise PHP will mangle the encoding.

Send raw ZPL to Zebra printer via USB

You haven't mentioned a language, so I'm going to give you some some hints how to do it with the straight Windows API in C.

First, open a connection to the printer with OpenPrinter. Next, start a document with StartDocPrinter having the pDatatype field of the DOC_INFO_1 structure set to "RAW" - this tells the printer driver not to encode anything going to the printer, but to pass it along unchanged. Use StartPagePrinter to indicate the first page, WritePrinter to send the data to the printer, and close it with EndPagePrinter, EndDocPrinter and ClosePrinter when done.

Where can I find "make" program for Mac OS X Lion?

After upgrading to Mountain Lion using the NDK, I had the following error:

Cannot find 'make' program. Please install Cygwin make package or define the GNUMAKE variable to point to it

Error was fixed by downloading and using the latest NDK

How to change the remote a branch is tracking?

I've found @critikaster's post helpful, except that I had to perform these commands with GIT 2.21:

$ git remote set-url origin https://some_url/some_repo
$ git push --set-upstream origin master

How to truncate a foreign key constrained table?

While this question was asked I didn't know about it, but now if you use phpMyAdmin you can simply open the database and select the table(s) you want to truncate.

  • At the bottom there is a drop down with many options. Open it and select Empty option under the heading Delete data or table.
  • It takes you to the next page automatically where there is an option in checkbox called Enable foreign key checks. Just unselect it and press the Yes button and the selected table(s) will be truncated.

Maybe it internally runs the query suggested in user447951's answer, but it is very convenient to use from phpMyAdmin interface.

Reload .profile in bash shell script (in unix)?

The bash script runs in a separate subshell. In order to make this work you will need to source this other script as well.

Unable to send email using Gmail SMTP server through PHPMailer, getting error: SMTP AUTH is required for message submission on port 587. How to fix?

If you are using cPanel you should just click the wee box that allows you to send to external servers by SMTP.

Login to CPanel > Tweak Settings > All> "Restrict outgoing SMTP to root, exim, and mailman (FKA SMTP Tweak)"

As answered here:

"Password not accepted from server: 535 Incorrect authentication data" when sending with GMail and phpMailer

Configuring user and password with Git Bash

If the git bash is not working properly due to recently changed password.

You could open the Git GUI, and clone from there. It will ask for password, once entered, you can close the GIT GUI window.

Now the git bash will work perfectly.

Eclipse error: "Editor does not contain a main type"

private int user_movie_matrix[][];Th. should be `private int user_movie_matrix[][];.

private int user_movie_matrix[][]; should be private static int user_movie_matrix[][];

cfiltering(numberOfUsers, numberOfMovies); should be new cfiltering(numberOfUsers, numberOfMovies);

Whether or not the code works as intended after these changes is beyond the scope of this answer; there were several syntax/scoping errors.

The Use of Multiple JFrames: Good or Bad Practice?

It's been a while since the last time i touch swing but in general is a bad practice to do this. Some of the main disadvantages that comes to mind:

  • It's more expensive: you will have to allocate way more resources to draw a JFrame that other kind of window container, such as Dialog or JInternalFrame.

  • Not user friendly: It is not easy to navigate into a bunch of JFrame stuck together, it will look like your application is a set of applications inconsistent and poorly design.

  • It's easy to use JInternalFrame This is kind of retorical, now it's way easier and other people smarter ( or with more spare time) than us have already think through the Desktop and JInternalFrame pattern, so I would recommend to use it.

angular2 submit form by pressing enter without submit button

add this inside your input tag

<input type="text" (keyup.enter)="yourMethod()" />

How to enable file sharing for my app?

If you editing info.plist directly, below should help you, don't key in "YES" as string below:

<key>UIFileSharingEnabled</key>
<string>YES</string>

You should use this:

<key>UIFileSharingEnabled</key>
<true/>

How to insert element into arrays at specific position?

try this one ===

$key_pos=0;
$a1=array("a"=>"red", "b"=>"green", "c"=>"blue", "d"=>"yellow");
$arrkey=array_keys($a1);
array_walk($arrkey,function($val,$key) use(&$key_pos) {
  if($val=='b')
    {
        $key_pos=$key;
    }
  });
$a2=array("e"=>"purple");
$newArray = array_slice($a1, 0, $key_pos, true) + $a2 +
        array_slice($a1, $key_pos, NULL, true);
print_r($newArray);

Output

Array (
      [a] => red
      [e] => purple
      [b] => green
      [c] => blue
      [d] => yellow )

return, return None, and no return at all?

As other have answered, the result is exactly the same, None is returned in all cases.

The difference is stylistic, but please note that PEP8 requires the use to be consistent:

Be consistent in return statements. Either all return statements in a function should return an expression, or none of them should. If any return statement returns an expression, any return statements where no value is returned should explicitly state this as return None, and an explicit return statement should be present at the end of the function (if reachable).

Yes:

def foo(x):
    if x >= 0:
        return math.sqrt(x)
    else:
        return None

def bar(x):
    if x < 0:
        return None
    return math.sqrt(x)

No:

def foo(x):
    if x >= 0:
        return math.sqrt(x)

def bar(x):
    if x < 0:
        return
    return math.sqrt(x)

https://www.python.org/dev/peps/pep-0008/#programming-recommendations


Basically, if you ever return non-None value in a function, it means the return value has meaning and is meant to be caught by callers. So when you return None, it must also be explicit, to convey None in this case has meaning, it is one of the possible return values.

If you don't need return at all, you function basically works as a procedure instead of a function, so just don't include the return statement.

If you are writing a procedure-like function and there is an opportunity to return earlier (i.e. you are already done at that point and don't need to execute the remaining of the function) you may use empty an returns to signal for the reader it is just an early finish of execution and the None value returned implicitly doesn't have any meaning and is not meant to be caught (the procedure-like function always returns None anyway).

How to turn a String into a JavaScript function call?

I wanted to be able to take a function name as a string, call it, AND pass an argument to the function. I couldn't get the selected answer for this question to do that, but this answer explained it exactly, and here is a short demo.

function test_function(argument)    {
    alert('This function ' + argument); 
}

functionName = 'test_function';

window[functionName]('works!');

This also works with multiple arguments.

Determining type of an object in ruby

you could also try: instance_of?

p 1.instance_of? Fixnum    #=> True
p "1".instance_of? String  #=> True
p [1,2].instance_of? Array #=> True

How to view an HTML file in the browser with Visual Studio Code

In linux, you can use the xdg-open command to open the file with the default browser:

{
    "version": "0.1.0",
    "linux": {
        "command": "xdg-open"
    },
    "isShellCommand": true,
    "showOutput": "never",
    "args": ["${file}"]
}

SVN - Checksum mismatch while updating

I had a simllar problem. Main provider was antivirus "FortiClient" (antivirus + VPN CLient). When I disabled it - all update/checkout was made correctly

Using an array as needles in strpos

The question, is the provided example just an "example" or exact what you looking for? There are many mixed answers here, and I dont understand the complexibility of the accepted one.

To find out if ANY content of the array of needles exists in the string, and quickly return true or false:

$string = 'abcdefg';

if(str_replace(array('a', 'c', 'd'), '', $string) != $string){
    echo 'at least one of the needles where found';
};

If, so, please give @Leon credit for that.

To find out if ALL values of the array of needles exists in the string, as in this case, all three 'a', 'b' and 'c' MUST be present, like you mention as your "for example"

echo 'All the letters are found in the string!';

Many answers here is out of that context, but I doubt that the intension of the question as you marked as resolved. E.g. The accepted answer is a needle of

$array  = array('burger', 'melon', 'cheese', 'milk');

What if all those words MUST be found in the string?

Then you try out some "not accepted answers" on this page.

How to change root logging level programmatically for logback

using logback 1.1.3 I had to do the following (Scala code):

import ch.qos.logback.classic.Logger
import org.slf4j.LoggerFactory    
...
val root: Logger = LoggerFactory.getLogger(org.slf4j.Logger.ROOT_LOGGER_NAME).asInstanceOf[Logger]

call a static method inside a class?

This is a very late response, but adds some detail on the previous answers

When it comes to calling static methods in PHP from another static method on the same class, it is important to differentiate between self and the class name.

Take for instance this code:

class static_test_class {
    public static function test() {
        echo "Original class\n";
    }

    public static function run($use_self) {
        if($use_self) {
            self::test();
        } else {
            $class = get_called_class();
            $class::test(); 
        }
    }
}

class extended_static_test_class extends static_test_class {
    public static function test() {
        echo "Extended class\n";
    }
}

extended_static_test_class::run(true);
extended_static_test_class::run(false);

The output of this code is:

Original class

Extended class

This is because self refers to the class the code is in, rather than the class of the code it is being called from.

If you want to use a method defined on a class which inherits the original class, you need to use something like:

$class = get_called_class();
$class::function_name(); 

.NET 4.0 has a new GAC, why?

It doesn't make a lot of sense, the original GAC was already quite capable of storing different versions of assemblies. And there's little reason to assume a program will ever accidentally reference the wrong assembly, all the .NET 4 assemblies got the [AssemblyVersion] bumped up to 4.0.0.0. The new in-process side-by-side feature should not change this.

My guess: there were already too many .NET projects out there that broke the "never reference anything in the GAC directly" rule. I've seen it done on this site several times.

Only one way to avoid breaking those projects: move the GAC. Back-compat is sacred at Microsoft.

How do I select a random value from an enumeration?

You can also cast a random value:

using System;

enum Test {
  Value1,
  Value2,
  Value3
}

class Program {
  public static void Main (string[] args) {
    var max = Enum.GetValues(typeof(Test)).Length;
    var value = (Test)new Random().Next(0, max - 1);
    Console.WriteLine(value);
  }
}

But you should use a better randomizer like the one in this library of mine.

Only variable references should be returned by reference - Codeigniter

It's not a better idea to override the core.common file of codeigniter. Because that's the more tested and system files....

I make a solution for this problem. In your ckeditor_helper.php file line- 65

if($k !== end (array_keys($data['config']))) {
       $return .= ",";
}

Change this to-->

 $segment = array_keys($data['config']);
    if($k !== end($segment)) {
           $return .= ",";
    }

I think this is the best solution and then your problem notice will dissappear.

Deactivate or remove the scrollbar on HTML

If you really need it...

html { overflow-y: hidden; }

How can I install the VS2017 version of msbuild on a build server without installing the IDE?

The Visual Studio Build tools are a different download than the IDE. They appear to be a pretty small subset, and they're called Build Tools for Visual Studio 2019 (download).

You can use the GUI to do the installation, or you can script the installation of msbuild:

vs_buildtools.exe --add Microsoft.VisualStudio.Workload.MSBuildTools --quiet

Microsoft.VisualStudio.Workload.MSBuildTools is a "wrapper" ID for the three subcomponents you need:

  • Microsoft.Component.MSBuild
  • Microsoft.VisualStudio.Component.CoreBuildTools
  • Microsoft.VisualStudio.Component.Roslyn.Compiler

You can find documentation about the other available CLI switches here.

The build tools installation is much quicker than the full IDE. In my test, it took 5-10 seconds. With --quiet there is no progress indicator other than a brief cursor change. If the installation was successful, you should be able to see the build tools in %programfiles(x86)%\Microsoft Visual Studio\2019\BuildTools\MSBuild\Current\Bin.

If you don't see them there, try running without --quiet to see any error messages that may occur during installation.

Is it possible to modify a registry entry via a .bat/.cmd script?

Yes, you can script using the reg command. Example:

reg add HKCU\Software\SomeProduct
reg add HKCU\Software\SomeProduct /v Version /t REG_SZ /d v2.4.6

This would create key HKEY_CURRENT_USER\Software\SomeProduct, and add a String value "v2.4.6" named "Version" to that key.

reg /? has the details.

What is a superfast way to read large files line-by-line in VBA?

I would think , in a large file scenario using a stream would be far more efficient, because memory consumption would be very small.

But your algorithm could alternate between using a stream and loading the entire thing in memory based on the file size. I wouldn't be surprised if one is only better than the other under certain criteria.

Is Python faster and lighter than C++?

I think those stats show that Python is much slower and uses more memory for those benchmarks - are you sure you're reading them the right way up?

In my experience, which is mostly with writing network- and file-system-bound programs in Python, Python isn't significantly slower in any way that matters. For that kind of work, its benefits outweigh its costs.

Android Image View Pinch Zooming

Custom zoom view in Kotlin

 import android.content.Context
 import android.graphics.Matrix
 import android.graphics.PointF
 import android.util.AttributeSet
 import android.util.Log
 import android.view.MotionEvent
 import android.view.ScaleGestureDetector
 import android.view.ScaleGestureDetector.SimpleOnScaleGestureListener
 import androidx.appcompat.widget.AppCompatImageView

 class ZoomImageview : AppCompatImageView {
var matri: Matrix? = null
var mode = NONE

// Remember some things for zooming
var last = PointF()
var start = PointF()
var minScale = 1f
var maxScale = 3f
lateinit var m: FloatArray
var viewWidth = 0
var viewHeight = 0
var saveScale = 1f
protected var origWidth = 0f
protected var origHeight = 0f
var oldMeasuredWidth = 0
var oldMeasuredHeight = 0
var mScaleDetector: ScaleGestureDetector? = null
var contex: Context? = null

constructor(context: Context) : super(context) {
    sharedConstructing(context)
}

constructor(context: Context, attrs: AttributeSet?) : super(context, attrs) {
    sharedConstructing(context)
}

private fun sharedConstructing(context: Context) {
    super.setClickable(true)
    this.contex= context
    mScaleDetector = ScaleGestureDetector(context, ScaleListener())
    matri = Matrix()
    m = FloatArray(9)
    imageMatrix = matri
    scaleType = ScaleType.MATRIX
    setOnTouchListener { v, event ->
        mScaleDetector!!.onTouchEvent(event)
        val curr = PointF(event.x, event.y)
        when (event.action) {
            MotionEvent.ACTION_DOWN -> {
                last.set(curr)
                start.set(last)
                mode = DRAG
            }
            MotionEvent.ACTION_MOVE -> if (mode == DRAG) {
                val deltaX = curr.x - last.x
                val deltaY = curr.y - last.y
                val fixTransX = getFixDragTrans(deltaX, viewWidth.toFloat(), origWidth * saveScale)
                val fixTransY = getFixDragTrans(deltaY, viewHeight.toFloat(), origHeight * saveScale)
                matri!!.postTranslate(fixTransX, fixTransY)
                fixTrans()
                last[curr.x] = curr.y
            }
            MotionEvent.ACTION_UP -> {
                mode = NONE
                val xDiff = Math.abs(curr.x - start.x).toInt()
                val yDiff = Math.abs(curr.y - start.y).toInt()
                if (xDiff < CLICK && yDiff < CLICK) performClick()
            }
            MotionEvent.ACTION_POINTER_UP -> mode = NONE
        }
        imageMatrix = matri
        invalidate()
        true // indicate event was handled
    }
}

fun setMaxZoom(x: Float) {
    maxScale = x
}

private inner class ScaleListener : SimpleOnScaleGestureListener() {
    override fun onScaleBegin(detector: ScaleGestureDetector): Boolean {
        mode = ZOOM
        return true
    }

    override fun onScale(detector: ScaleGestureDetector): Boolean {
        var mScaleFactor = detector.scaleFactor
        val origScale = saveScale
        saveScale *= mScaleFactor
        if (saveScale > maxScale) {
            saveScale = maxScale
            mScaleFactor = maxScale / origScale
        } else if (saveScale < minScale) {
            saveScale = minScale
            mScaleFactor = minScale / origScale
        }
        if (origWidth * saveScale <= viewWidth || origHeight * saveScale <= viewHeight) matri!!.postScale(mScaleFactor, mScaleFactor, viewWidth / 2.toFloat(), viewHeight / 2.toFloat()) else matri!!.postScale(mScaleFactor, mScaleFactor, detector.focusX, detector.focusY)
        fixTrans()
        return true
    }
}

fun fixTrans() {
    matri!!.getValues(m)
    val transX = m[Matrix.MTRANS_X]
    val transY = m[Matrix.MTRANS_Y]
    val fixTransX = getFixTrans(transX, viewWidth.toFloat(), origWidth * saveScale)
    val fixTransY = getFixTrans(transY, viewHeight.toFloat(), origHeight * saveScale)
    if (fixTransX != 0f || fixTransY != 0f) matri!!.postTranslate(fixTransX, fixTransY)
}

fun getFixTrans(trans: Float, viewSize: Float, contentSize: Float): Float {
    val minTrans: Float
    val maxTrans: Float
    if (contentSize <= viewSize) {
        minTrans = 0f
        maxTrans = viewSize - contentSize
    } else {
        minTrans = viewSize - contentSize
        maxTrans = 0f
    }
    if (trans < minTrans) return -trans + minTrans
    if (trans > maxTrans) return -trans + maxTrans
    return 0f
}

fun getFixDragTrans(delta: Float, viewSize: Float, contentSize: Float): Float {
    if (contentSize <= viewSize) {
        return 0f
    } else {
        return delta
    }
}

override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec)
    viewWidth = MeasureSpec.getSize(widthMeasureSpec)
    viewHeight = MeasureSpec.getSize(heightMeasureSpec)
    //
    // Rescales image on rotation
    //
    if (oldMeasuredHeight == viewWidth && oldMeasuredHeight == viewHeight || viewWidth == 0 || viewHeight == 0) return
    oldMeasuredHeight = viewHeight
    oldMeasuredWidth = viewWidth
    if (saveScale == 1f) {
        //Fit to screen.
        val scale: Float
        val drawable = drawable
        if (drawable == null || drawable.intrinsicWidth == 0 || drawable.intrinsicHeight == 0) return
        val bmWidth = drawable.intrinsicWidth
        val bmHeight = drawable.intrinsicHeight
        Log.d("bmSize", "bmWidth: $bmWidth bmHeight : $bmHeight")
        val scaleX = viewWidth.toFloat() / bmWidth.toFloat()
        val scaleY = viewHeight.toFloat() / bmHeight.toFloat()
        scale = Math.min(scaleX, scaleY)
        matri!!.setScale(scale, scale)
        // Center the image
        var redundantYSpace = viewHeight.toFloat() - scale * bmHeight.toFloat()
        var redundantXSpace = viewWidth.toFloat() - scale * bmWidth.toFloat()
        redundantYSpace /= 2.toFloat()
        redundantXSpace /= 2.toFloat()
        matri!!.postTranslate(redundantXSpace, redundantYSpace)
        origWidth = viewWidth - 2 * redundantXSpace
        origHeight = viewHeight - 2 * redundantYSpace
        imageMatrix = matri
    }
    fixTrans()
}

companion object {
    // We can be in one of these 3 states
    const val NONE = 0
    const val DRAG = 1
    const val ZOOM = 2
    const val CLICK = 3
}
 }

How to set default text for a Tkinter Entry widget

Use Entry.insert. For example:

try:
    from tkinter import *  # Python 3.x
except Import Error:
    from Tkinter import *  # Python 2.x

root = Tk()
e = Entry(root)
e.insert(END, 'default text')
e.pack()
root.mainloop()

Or use textvariable option:

try:
    from tkinter import *  # Python 3.x
except Import Error:
    from Tkinter import *  # Python 2.x

root = Tk()
v = StringVar(root, value='default text')
e = Entry(root, textvariable=v)
e.pack()
root.mainloop()

How to insert the current timestamp into MySQL database using a PHP insert query

Instead of NOW() you can use UNIX_TIMESTAMP() also:

$update_query = "UPDATE db.tablename 
                 SET insert_time=UNIX_TIMESTAMP()
                 WHERE username='$somename'";

Difference between UNIX_TIMESTAMP and NOW() in MySQL

How does setTimeout work in Node.JS?

The semantics of setTimeout are roughly the same as in a web browser: the timeout arg is a minimum number of ms to wait before executing, not a guarantee. Furthermore, passing 0, a non-number, or a negative number, will cause it to wait a minimum number of ms. In Node, this is 1ms, but in browsers it can be as much as 50ms.

The reason for this is that there is no preemption of JavaScript by JavaScript. Consider this example:

setTimeout(function () {
  console.log('boo')
}, 100)
var end = Date.now() + 5000
while (Date.now() < end) ;
console.log('imma let you finish but blocking the event loop is the best bug of all TIME')

The flow here is:

  1. schedule the timeout for 100ms.
  2. busywait for 5000ms.
  3. return to the event loop. check for pending timers and execute.

If this was not the case, then you could have one bit of JavaScript "interrupt" another. We'd have to set up mutexes and semaphors and such, to prevent code like this from being extremely hard to reason about:

var a = 100;
setTimeout(function () {
  a = 0;
}, 0);
var b = a; // 100 or 0?

The single-threadedness of Node's JavaScript execution makes it much simpler to work with than most other styles of concurrency. Of course, the trade-off is that it's possible for a badly-behaved part of the program to block the whole thing with an infinite loop.

Is this a better demon to battle than the complexity of preemption? That depends.

JSLint is suddenly reporting: Use the function form of "use strict"

There's nothing innately wrong with the string form.

Rather than avoid the "global" strict form for worry of concatenating non-strict javascript, it's probably better to just fix the damn non-strict javascript to be strict.

How to get the row number from a datatable?

ArrayList check = new ArrayList();            

for (int i = 0; i < oDS.Tables[0].Rows.Count; i++)
{
    int iValue = Convert.ToInt32(oDS.Tables[0].Rows[i][3].ToString());
    check.Add(iValue);

}

Is a LINQ statement faster than a 'foreach' loop?

It should probably be noted that the for loop is faster than the foreach. So for the original post, if you are worried about performance on a critical component like a renderer, use a for loop.

Reference: In .NET, which loop runs faster, 'for' or 'foreach'?

How to check type of variable in Java?

I wasn't happy with any of these answers, and the one that's right has no explanation and negative votes so I searched around, found some stuff and edited it so that it is easy to understand. Have a play with it, not as straight forward as one would hope.

//move your variable into an Object type
Object obj=whatYouAreChecking;
System.out.println(obj);

// moving the class type into a Class variable
Class cls=obj.getClass();
System.out.println(cls);

// convert that Class Variable to a neat String
String answer = cls.getSimpleName();
System.out.println(answer);

Here is a method:

public static void checkClass (Object obj) {
    Class cls = obj.getClass();
    System.out.println("The type of the object is: " + cls.getSimpleName());       
}

How to commit and rollback transaction in sql server?

Don't use @@ERROR, use BEGIN TRY/BEGIN CATCH instead. See this article: Exception handling and nested transactions for a sample procedure:

create procedure [usp_my_procedure_name]
as
begin
    set nocount on;
    declare @trancount int;
    set @trancount = @@trancount;
    begin try
        if @trancount = 0
            begin transaction
        else
            save transaction usp_my_procedure_name;

        -- Do the actual work here

lbexit:
        if @trancount = 0   
            commit;
    end try
    begin catch
        declare @error int, @message varchar(4000), @xstate int;
        select @error = ERROR_NUMBER(), @message = ERROR_MESSAGE(), @xstate = XACT_STATE();
        if @xstate = -1
            rollback;
        if @xstate = 1 and @trancount = 0
            rollback
        if @xstate = 1 and @trancount > 0
            rollback transaction usp_my_procedure_name;

        raiserror ('usp_my_procedure_name: %d: %s', 16, 1, @error, @message) ;
        return;
    end catch   
end

Add one day to date in javascript

There is issue of 31st and 28th Feb with getDate() I use this function getTime and 24*60*60*1000 = 86400000

_x000D_
_x000D_
var dateWith31 = new Date("2017-08-31");_x000D_
var dateWith29 = new Date("2016-02-29");_x000D_
_x000D_
var amountToIncreaseWith = 1; //Edit this number to required input_x000D_
_x000D_
console.log(incrementDate(dateWith31,amountToIncreaseWith));_x000D_
console.log(incrementDate(dateWith29,amountToIncreaseWith));_x000D_
_x000D_
function incrementDate(dateInput,increment) {_x000D_
        var dateFormatTotime = new Date(dateInput);_x000D_
        var increasedDate = new Date(dateFormatTotime.getTime() +(increment *86400000));_x000D_
        return increasedDate;_x000D_
    }
_x000D_
_x000D_
_x000D_

How do I make a newline after a twitter bootstrap element?

You're using span6 and span2. Both of these classes are "float:left" meaning, if possible they will always try to sit next to each other. Twitter bootstrap is based on a 12 grid system. So you should generally always get the span**#** to add up to 12.

E.g.: span4 + span4 + span4 OR span6 + span6 OR span4 + span3 + span5.

To force a span down though, without listening to the previous float you can use twitter bootstraps clearfix class. To do this, your code should look like this:

<ul class="nav nav-tabs span2">
  <li><a href="./index.html"><i class="icon-black icon-music"></i></a></li>
  <li><a href="./about.html"><i class="icon-black icon-eye-open"></i></a></li>
  <li><a href="./team.html"><i class="icon-black icon-user"></i></a></li>
  <li><a href="./contact.html"><i class="icon-black icon-envelope"></i></a></li>
</ul>
<!-- Notice this following line -->
<div class="clearfix"></div>
<div class="well span6">
  <h3>I wish this appeared on the next line without having to gratuitously use BR!</h3>
</div>

Version of Apache installed on a Debian machine

Try apachectl -V:

$ apachectl -V
Server version: Apache/2.2.9 (Unix)
Server built:   Sep 18 2008 21:54:05
Server's Module Magic Number: 20051115:15
Server loaded:  APR 1.2.7, APR-Util 1.2.7
Compiled using: APR 1.2.7, APR-Util 1.2.7
... etc ...

If it does not work for you, run the command with sudo.

Execute method on startup in Spring

If you want to configure a bean before your application is running fully, you can use @Autowired:

@Autowired
private void configureBean(MyBean: bean) {
    bean.setConfiguration(myConfiguration);
}

Trouble setting up git with my GitHub Account error: could not lock config file

For me, the problem was not git config, but .git directory at my current repo was created by root and I was trying to do something with my other user. I changed the perm

What is aria-label and how should I use it?

In the example you give, you're perfectly right, you have to set the title attribute.

If the aria-label is one tool used by assistive technologies (like screen readers), it is not natively supported on browsers and has no effect on them. It won't be of any help to most of the people targetted by the WCAG (except screen reader users), for instance a person with intellectal disabilities.

The "X" is not sufficient enough to give information to the action led by the button (think about someone with no computer knowledge). It might mean "close", "delete", "cancel", "reduce", a strange cross, a doodle, nothing.

Despite the fact that the W3C seems to promote the aria-label rather that the title attribute here: http://www.w3.org/TR/2014/NOTE-WCAG20-TECHS-20140916/ARIA14 in a similar example, you can see that the technology support does not include standard browsers : http://www.w3.org/WAI/WCAG20/Techniques/ua-notes/aria#ARIA14

In fact aria-label, in this exact situation might be used to give more context to an action:

For instance, blind people do not perceive popups like those of us with good vision, it's like a change of context. "Back to the page" will be a more convenient alternative for a screen reader, when "Close" is more significant for someone with no screen reader.

  <button
      aria-label="Back to the page"
      title="Close" onclick="myDialog.close()">X</button>

How to retrieve absolute path given relative

The best solution, imho, is the one posted here: https://stackoverflow.com/a/3373298/9724628.

It does require python to work, but it seems to cover all or most of the edge cases and be very portable solution.

  1. With resolving symlinks:
python -c "import os,sys; print(os.path.realpath(sys.argv[1]))" path/to/file
  1. or without it:
python -c "import os,sys; print(os.path.abspath(sys.argv[1]))" path/to/file

Java: method to get position of a match in a String?

If you're going to scan for 'n' matches of the search string, I'd recommend using regular expressions. They have a steep learning curve, but they'll save you hours when it comes to complex searches.

How to append a jQuery variable value inside the .html tag

See this Link

HTML

<div id="products"></div>

JS

var someone = {
"name":"Mahmoude Elghandour",
"price":"174 SR",
"desc":"WE Will BE WITH YOU"
 };
 var name = $("<div/>",{"text":someone.name,"class":"name"
});

var price = $("<div/>",{"text":someone.price,"class":"price"});
var desc = $("<div />", {   
"text": someone.desc,
"class": "desc"
});
$("#products").fadeIn(1500);
$("#products").append(name).append(price).append(desc);

Recover unsaved SQL query scripts

For SSMS 18, I found the files at:

C:\Users\YourUserName\Documents\Visual Studio 2017\Backup Files\Solution1

For SSMS 17, It was used to be at:

C:\Users\YourUserName\Documents\Visual Studio 2015\Backup Files\Solution1

android get all contacts

Improving on the answer of @Adiii - It Will Cleanup The Phone Number and Remove All Duplicates

Declare a Global Variable

// Hash Maps
Map<String, String> namePhoneMap = new HashMap<String, String>();

Then Use The Function Below

private void getPhoneNumbers() {

        Cursor phones = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, null, null, null);

        // Loop Through All The Numbers
        while (phones.moveToNext()) {

            String name = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
            String phoneNumber = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));

            // Cleanup the phone number
            phoneNumber = phoneNumber.replaceAll("[()\\s-]+", "");

            // Enter Into Hash Map
            namePhoneMap.put(phoneNumber, name);

        }

        // Get The Contents of Hash Map in Log
        for (Map.Entry<String, String> entry : namePhoneMap.entrySet()) {
            String key = entry.getKey();
            Log.d(TAG, "Phone :" + key);
            String value = entry.getValue();
            Log.d(TAG, "Name :" + value);
        }

        phones.close();

    }

Remember in the above example the key is phone number and value is a name so read your contents like 998xxxxx282->Mahatma Gandhi instead of Mahatma Gandhi->998xxxxx282

Getting Lat/Lng from Google marker

There are a lot of answers to this question, which never worked for me (including suggesting getPosition() which doesn't seem to be a method available for markers objects). The only method that worked for me in maps V3 is (simply) :

var lat = marker.lat();
var long = marker.lng();

How to loop an object in React?

you could also just have a return div like the one below and use the built in template literals of Javascript :

const tifs = {1: 'Joe', 2: 'Jane'};

return(

        <div>
            {Object.keys(tifOptions).map((key)=>(
                <p>{paragraphs[`${key}`]}</p>
            ))}
        </div>
    )

How to give a time delay of less than one second in excel vba?

I found this on another site not sure if it works or not.

Application.Wait Now + 1/(24*60*60.0*2)

the numerical value 1 = 1 day

1/24 is one hour

1/(24*60) is one minute

so 1/(24*60*60*2) is 1/2 second

You need to use a decimal point somewhere to force a floating point number

Source

Not sure if this will work worth a shot for milliseconds

Application.Wait (Now + 0.000001) 

Bootstrap: how do I change the width of the container?

Go to the Customize section on Bootstrap site and choose the size you prefer. You'll have to set @gridColumnWidth and @gridGutterWidth variables.

For example: @gridColumnWidth = 65px and @gridGutterWidth = 20px results on a 1000px layout.

Then download it.

Node.js project naming conventions for files & folders

After some years with node, I can say that there are no conventions for the directory/file structure. However most (professional) express applications use a setup like:

/
  /bin - scripts, helpers, binaries
  /lib - your application
  /config - your configuration
  /public - your public files
  /test - your tests

An example which uses this setup is nodejs-starter.

I personally changed this setup to:

/
  /etc - contains configuration
  /app - front-end javascript files
    /config - loads config
    /models - loads models
  /bin - helper scripts
  /lib - back-end express files
    /config - loads config to app.settings
    /models - loads mongoose models
    /routes - sets up app.get('..')...
  /srv - contains public files
  /usr - contains templates
  /test - contains test files

In my opinion, the latter matches better with the Unix-style directory structure (whereas the former mixes this up a bit).

I also like this pattern to separate files:

lib/index.js

var http = require('http');
var express = require('express');

var app = express();

app.server = http.createServer(app);

require('./config')(app);

require('./models')(app);

require('./routes')(app);

app.server.listen(app.settings.port);

module.exports = app;

lib/static/index.js

var express = require('express');

module.exports = function(app) {

  app.use(express.static(app.settings.static.path));

};

This allows decoupling neatly all source code without having to bother dependencies. A really good solution for fighting nasty Javascript. A real-world example is nearby which uses this setup.

Update (filenames):

Regarding filenames most common are short, lowercase filenames. If your file can only be described with two words most JavaScript projects use an underscore as the delimiter.

Update (variables):

Regarding variables, the same "rules" apply as for filenames. Prototypes or classes, however, should use camelCase.

Update (styleguides):

How to replace all occurrences of a string in Javascript?

I would suggest adding a global method for string class by appending it to prototype chain.

String.prototype.replaceAll = function(fromReplace, toReplace, {ignoreCasing} = {}) { return this.replace(new RegExp(fromReplace, ignoreCasing ? 'ig': 'g'), toReplace);}

and it can be used like

'stringwithpattern'.replaceAll('pattern','new-pattern')

appcompat-v7:21.0.0': No resource found that matches the given name: attr 'android:actionModeShareDrawable'

This is likely because you haven't set your compileSdkVersion to 21 in your build.gradle file. You also probably want to change your targetSdkVersion to 21.

android {
    //...
    compileSdkVersion 21

    defaultConfig {
        targetSdkVersion 21
    }
    //...
}

This requires you to have downloaded the latest SDK updates to begin with.

Android Studio SDK Manager

Once you've downloaded all the updates (don't forget to also update the Android Support Library/Repository, too!) and updated your compileSdkVersion, re-sync your Gradle project.

Edit: For Eclipse or general IntelliJ users

See reVerse's answer. He has a very thorough walk through!

Get file size before uploading

you need to do an ajax HEAD request to get the filesize. with jquery it's something like this

  var req = $.ajax({
    type: "HEAD",
    url: yoururl,
    success: function () {
      alert("Size is " + request.getResponseHeader("Content-Length"));
    }
  });

How to run a bash script from C++ program

Since this is a pretty old question, and this method hasn't been added (aside from the system() call function) I guess it would be useful to include creating the shell script with the C binary itself. The shell code will be housed inside the file.c source file. Here is an example of code:

#include <stdio.h>
#include <stdlib.h>

#define SHELLSCRIPT "\
#/bin/bash \n\
echo -e \"\" \n\
echo -e \"This is a test shell script inside C code!!\" \n\
read -p \"press <enter> to continue\" \n\
clear\
"

int main() {

system(SHELLSCRIPT);
return 0;
}

Basically, in a nutshell (pun intended), we are defining the script name, fleshing out the script, enclosing them in double quotes (while inserting proper escapes to ignore double quotes in the shell code), and then calling that script's name, which in this example is SHELLSCRIPT using the system() function in main().

React - changing an uncontrolled input

An update for this. For React Hooks use const [name, setName] = useState(" ")

Passing a method as a parameter in Ruby

I would recommend to use ampersand to have an access to named blocks within a function. Following the recommendations given in this article you can write something like this (this is a real scrap from my working program):

  # Returns a valid hash for html form select element, combined of all entities
  # for the given +model+, where only id and name attributes are taken as
  # values and keys correspondingly. Provide block returning boolean if you
  # need to select only specific entities.
  #
  # * *Args*    :
  #   - +model+ -> ORM interface for specific entities'
  #   - +&cond+ -> block {|x| boolean}, filtering entities upon iterations
  # * *Returns* :
  #   - hash of {entity.id => entity.name}
  #
  def make_select_list( model, &cond )
    cond ||= proc { true } # cond defaults to proc { true }
    # Entities filtered by cond, followed by filtration by (id, name)
    model.all.map do |x|
      cond.( x ) ? { x.id => x.name } : {}
    end.reduce Hash.new do |memo, e| memo.merge( e ) end
  end

Afterwerds, you can call this function like this:

@contests = make_select_list Contest do |contest|
  logged_admin? or contest.organizer == @current_user
end

If you don't need to filter your selection, you simply omit the block:

@categories = make_select_list( Category ) # selects all categories

So much for the power of Ruby blocks.

How to convert HTML file to word?

When doing this I found it easiest to:

  1. Visit the page in a web browser
  2. Save the page using the web browser with .htm extension (and maybe a folder with support files)
  3. Start Word and open the saved htmfile (Word will open it correctly)
  4. Make any edits if needed
  5. Select Save As and then choose the extension you would like doc, docx, etc.

How can I get the error message for the mail() function?

There is no error message associated with the mail() function. There is only a true or false returned on whether the email was accepted for delivery. Not whether it ultimately gets delivered, but basically whether the domain exists and the address is a validly formatted email address.

Exclude subpackages from Spring autowiring?

For Spring 4 I use the following
(I am posting it as the question is 4 years old and more people use Spring 4 than Spring 3.1):

@Configuration
@ComponentScan(basePackages = "com.example", 
  excludeFilters = @Filter(type=FilterType.REGEX,pattern="com\\.example\\.ignore\\..*")) 
public class RootConfig {
    // ...
}

TokenMismatchException in VerifyCsrfToken.php Line 67

try changing the session lifetime on config/session.php like this :

'lifetime' => 120, to 'lifetime' => 360,

Here I set lifetime to 360, hope this help.

Best JavaScript compressor

If you use Packer, just go far the 'shrink variables' option and gzip the resulting code. The base62 option is only for if your server cannot send gzipped files. Packer with 'shrink vars' achieves better compression the YUI, but can introduce bugs if you've skipped a semicolon somewhere.

base62 is basically a poor man's gzip, which is why gzipping base62-ed code gives you bigger files than gzipping shrink-var-ed code.

Jquery Hide table rows

$('inputFile').parent().parent().children('td > label').hide();

can help you navigate two levels up ( to TD, to TR ) moving two levels back down ( all TD's in that TR and their LABEL tags ), applying the hide() function there.

if you want to stay at the TR level and hide them:

$('inputFile').parent().parent().hide();

… is sufficient.

you can navigate very easily through the elements using the jquery selectors.

parent is documented here: http://api.jquery.com/parent/

hide is documented here: http://api.jquery.com/hide/

Installing a dependency with Bower from URL and specify version

Use a git endpoint instead of a package name:

bower install https://github.com/jquery/jquery.git#2.0.3

How to know if two arrays have the same values

Another one line solution:

array1.concat(array2).filter((item, index, currentArr) => currentArr.lastIndexOf(item) == currentArr.indexOf(item)).length == 0;

or

[...array1, ...array2].filter((item, index, currentArr) => currentArr.lastIndexOf(item) == currentArr.indexOf(item)).length == 0;

Is it possible to write to the console in colour in .NET?

Above comments are both solid responses, however note that they aren't thread safe. If you are writing to the console with multiple threads, changing colors will add a race condition that can create some strange looking output. It is simple to fix though:

public class ConsoleWriter
{
    private static object _MessageLock= new object();

    public void WriteMessage(string message)
    {
        lock (_MessageLock)
        {
            Console.BackgroundColor = ConsoleColor.Red;
            Console.WriteLine(message);
            Console.ResetColor();
        }
    }
}

How can I convert a string to a float in mysql?

It turns out I was just missing DECIMAL on the CAST() description:

DECIMAL[(M[,D])]

Converts a value to DECIMAL data type. The optional arguments M and D specify the precision (M specifies the total number of digits) and the scale (D specifies the number of digits after the decimal point) of the decimal value. The default precision is two digits after the decimal point.

Thus, the following query worked:

UPDATE table SET
latitude = CAST(old_latitude AS DECIMAL(10,6)),
longitude = CAST(old_longitude AS DECIMAL(10,6));

What is the purpose of the single underscore "_" variable in Python?

There are 5 cases for using the underscore in Python.

  1. For storing the value of last expression in interpreter.

  2. For ignoring the specific values. (so-called “I don’t care”)

  3. To give special meanings and functions to name of variables or functions.

  4. To use as ‘internationalization (i18n)’ or ‘localization (l10n)’ functions.

  5. To separate the digits of number literal value.

Here is a nice article with examples by mingrammer.

Does bootstrap 4 have a built in horizontal divider?

You can use the mt and mb spacing utilities to add extra margins to the <hr>, for example:

<hr class="mt-5 mb-5">

https://getbootstrap.com/docs/4.3/utilities/spacing/

How to get param from url in angular 4?

Hope this helps someone. In case that u get undefined while doing this with something that's not "id", check if u are passing right parameter:

If your route in parent-component.ts is:

 onSelect(elem) {
    this.router.navigateByUrl(`/element/${elem.type}`);
  }

And in child-component.ts

  type: string;
  elem: ElemModel;

  constructor(
    private elemService: ElemService,
    private route: ActivatedRoute
  ) {}

  ngOnInit() {
    this.route.params.subscribe((data) => {

      console.log(data);  // 'data' will give u an object with the type inside, check the 
      name of that type inside console of devTool, as u will put that name inside 
      data[HERE] down below.

      this.type = data["elem-type-maybe"]; // Don't do this.type = data["type"], do 
      data[NAME] as said above.

      this.elem = this.elemService.getElem(this.type); // getElem is method in service 
      which returns that specific type.
    });

Running script upon login mac

  1. Create your shell script as login.sh in your $HOME folder.

  2. Paste the following one-line script into Script Editor:

    do shell script "$HOME/login.sh"

  3. Then save it as an application.

  4. Finally add the application to your login items.

If you want to make the script output visual, you can swap step 2 for this:

tell application "Terminal"
  activate
  do script "$HOME/login.sh"
end tell

If multiple commands are needed something like this can be used:

tell application "Terminal"
  activate
  do script "cd $HOME"
  do script "./login.sh" in window 1
end tell

String comparison - Android

In Java we don't compare string as you are doing above... Here is String comparison...

    if (gender.equalsIgnoreCase("Male")) {
        salutation = "Mr.";
    } else if (gender.equalsIgnoreCase("Female")) {
        salutation = "Ms.";
    }

I am receiving warning in Facebook Application using PHP SDK

You need to ensure that any code that modifies the HTTP headers is executed before the headers are sent. This includes statements like session_start(). The headers will be sent automatically when any HTML is output.

Your problem here is that you're sending the HTML ouput at the top of your page before you've executed any PHP at all.

Move the session_start() to the top of your document :

<?php    session_start(); ?> <html> <head> <title>PHP SDK</title> </head> <body> <?php require_once 'src/facebook.php';    // more PHP code here. 

oracle sql: update if exists else insert

You could use the SQL%ROWCOUNT Oracle variable:

UPDATE table1
  SET field2 = value2, 
      field3 = value3 
WHERE field1 = value1; 

IF (SQL%ROWCOUNT = 0) THEN 

  INSERT INTO table (field1, field2, field3)
  VALUES (value1, value2, value3);

END IF; 

It would be easier just to determine if your primary key (i.e. field1) has a value and then perform an insert or update accordingly. That is, if you use said values as parameters for a stored procedure.

Download file from an ASP.NET Web API method using AngularJS

I have gone through array of solutions and this is what I found to have worked great for me.

In my case I needed to send a post request with some credentials. Small overhead was to add jquery inside the script. But was worth it.

var printPDF = function () {
        //prevent double sending
        var sendz = {};
        sendz.action = "Print";
        sendz.url = "api/Print";
        jQuery('<form action="' + sendz.url + '" method="POST">' +
            '<input type="hidden" name="action" value="Print" />'+
            '<input type="hidden" name="userID" value="'+$scope.user.userID+'" />'+
            '<input type="hidden" name="ApiKey" value="' + $scope.user.ApiKey+'" />'+
            '</form>').appendTo('body').submit().remove();

    }

sendKeys() in Selenium web driver

I have found that creating a var to hold the WebElement and the call the sendKeys() works for me.

WebElement speedCurrentCell = driver.findElement(By.id("Speed_current"));
speedCurrentCell.sendKeys("1300");

ssh remote host identification has changed

Remove that the entry from known_hosts using:

ssh-keygen -R *ip_address_or_hostname*

This will remove the problematic IP or hostname from known_hosts file and try to connect again.

From the man pages:

-R hostname
Removes all keys belonging to hostname from a known_hosts file. This option is useful to delete hashed hosts (see the -H option above).

How to make correct date format when writing data to Excel

Expanding slightly on @Assaf answer, to apply formatting correctly I also had to convert the DateTime via the .ToOADate() function before the formatting took effect. You can do this on a cell by cell basis:

xlWorkSheet.Cells[Row, Col].NumberFormat = "<Required Format>"; // e.g. dd-MMM-yyyy
xlWorkSheet.Cells[Row, Col] = DateTimeObject.ToOADate();

Or you can apply the formatting to the entire column:

xlWorkSheet.Cells[Row, Col].EntireColumn.NumberFormat = "<Required Format>"; // e.g. dd-MMM-yyyy
xlWorkSheet.Cells[Row, Col] = DateTimeObject.ToOADate();

How does Access-Control-Allow-Origin header work?

Nginx and Appache

As addition to apsillers answer I would like to add wiki graph which shows when request is simple or not (and OPTIONS pre-flight request is send or not)

Enter image description here

For simple request (e.g. hotlinking images) you don't need to change your server configuration files but you can add headers in application (hosted on server, e.g. in php) like Melvin Guerrero mention in his answer - but remember: if you add full cors headers in you server (config) and at same time you allow simple cors on application (e.g. php) this will not work at all.

And here are configurations for two popular servers

  • turn on CORS on Nginx (nginx.conf file)

    _x000D_
    _x000D_
    location ~ ^/index\.php(/|$) {
       ...
        add_header 'Access-Control-Allow-Origin' "$http_origin" always; # if you change "$http_origin" to "*" you shoud get same result - allow all domain to CORS (but better change it to your particular domain)
        add_header 'Access-Control-Allow-Credentials' 'true' always;
        if ($request_method = OPTIONS) {
            add_header 'Access-Control-Allow-Origin' "$http_origin"; # DO NOT remove THIS LINES (doubled with outside 'if' above)
            add_header 'Access-Control-Allow-Credentials' 'true';
            add_header 'Access-Control-Max-Age' 1728000; # cache preflight value for 20 days
            add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';  # arbitrary methods
            add_header 'Access-Control-Allow-Headers' 'My-First-Header,My-Second-Header,Authorization,Content-Type,Accept,Origin'; # arbitrary headers
            add_header 'Content-Length' 0;
            add_header 'Content-Type' 'text/plain charset=UTF-8';
            return 204;
        }
    }
    _x000D_
    _x000D_
    _x000D_

  • turn on CORS on Appache (.htaccess file)

    _x000D_
    _x000D_
    # ------------------------------------------------------------------------------
    # | Cross-domain Ajax requests                                                 |
    # ------------------------------------------------------------------------------
    
    # Enable cross-origin Ajax requests.
    # http://code.google.com/p/html5security/wiki/CrossOriginRequestSecurity
    # http://enable-cors.org/
    
    # change * (allow any domain) below to your domain
    Header set Access-Control-Allow-Origin "*"
    Header always set Access-Control-Allow-Methods "POST, GET, OPTIONS, DELETE, PUT"
    Header always set Access-Control-Allow-Headers "My-First-Header,My-Second-Header,Authorization, content-type, csrf-token"
    Header always set Access-Control-Allow-Credentials "true"
    _x000D_
    _x000D_
    _x000D_

ERROR 1064 (42000): You have an error in your SQL syntax; Want to configure a password as root being the user

On MySQL 8.0.15 (maybe earlier than this too): the PASSWORD() function does not work anymore, so you have to do:

Make sure you have stopped MySQL first (Go to: 'System Preferences' >> 'MySQL' and stop MySQL).

Run the server in safe mode with privilege bypass:

sudo mysqld_safe --skip-grant-tables
mysql -u root
UPDATE mysql.user SET authentication_string=null WHERE User='root';
FLUSH PRIVILEGES;
exit;

Then

mysql -u root
ALTER USER 'root'@'localhost' IDENTIFIED WITH caching_sha2_password BY 'yourpasswd';

Finally, start your MySQL again.

Enlighten by @OlatunjiYso in this GitHub issue.

UPDATE with CASE and IN - Oracle

Got a solution that runs. Don't know if it is optimal though. What I do is to split the string according to http://blogs.oracle.com/aramamoo/2010/05/how_to_split_comma_separated_string_and_pass_to_in_clause_of_select_statement.html

Using:
select regexp_substr(' 1, 2 , 3 ','[^,]+', 1, level) from dual
connect by regexp_substr('1 , 2 , 3 ', '[^,]+', 1, level) is not null;

So my final code looks like this ($bp_gr1' are strings like 1,2,3):

UPDATE TAB1
SET    BUDGPOST_GR1 =
          CASE
             WHEN ( BUDGPOST IN (SELECT     REGEXP_SUBSTR ( '$BP_GR1',
                                                            '[^,]+',
                                                            1,
                                                            LEVEL )
                                 FROM       DUAL
                                 CONNECT BY REGEXP_SUBSTR ( '$BP_GR1',
                                                            '[^,]+',
                                                            1,
                                                            LEVEL )
                                               IS NOT NULL) )
             THEN
                'BP_GR1'
             WHEN ( BUDGPOST IN (SELECT     REGEXP_SUBSTR ( ' $BP_GR2',
                                                            '[^,]+',
                                                            1,
                                                            LEVEL )
                                 FROM       DUAL
                                 CONNECT BY REGEXP_SUBSTR ( '$BP_GR2',
                                                            '[^,]+',
                                                            1,
                                                            LEVEL )
                                               IS NOT NULL) )
             THEN
                'BP_GR2'
             WHEN ( BUDGPOST IN (SELECT     REGEXP_SUBSTR ( ' $BP_GR3',
                                                            '[^,]+',
                                                            1,
                                                            LEVEL )
                                 FROM       DUAL
                                 CONNECT BY REGEXP_SUBSTR ( '$BP_GR3',
                                                            '[^,]+',
                                                            1,
                                                            LEVEL )
                                               IS NOT NULL) )
             THEN
                'BP_GR3'
             WHEN ( BUDGPOST IN (SELECT     REGEXP_SUBSTR ( '$BP_GR4',
                                                            '[^,]+',
                                                            1,
                                                            LEVEL )
                                 FROM       DUAL
                                 CONNECT BY REGEXP_SUBSTR ( '$BP_GR4',
                                                            '[^,]+',
                                                            1,
                                                            LEVEL )
                                               IS NOT NULL) )
             THEN
                'BP_GR4'
             ELSE
                'SAKNAR BUDGETGRUPP'
          END;

Is there a way to make it run faster?

How do I update a Tomcat webapp without restarting the entire service?

Have you tried to use Tomcat's Manager application? It allows you to undeploy / deploy war files with out shutting Tomcat down.

If you don't want to use the Manager application, you can also delete the war file from the webapps directory, Tomcat will undeploy the application after a short period of time. You can then copy a war file back into the directory, and Tomcat will deploy the war file.

If you are running Tomcat on Windows, you may need to configure your Context to not lock various files.

If you absolutely can't have any downtime, you may want to look at Tomcat 7's Parallel deployments You may deploy multiple versions of a web application with the same context path at the same time. The rules used to match requests to a context version are as follows:

  • If no session information is present in the request, use the latest version.
  • If session information is present in the request, check the session manager of each version for a matching session and if one is found, use that version.
  • If session information is present in the request but no matching session can be found, use the latest version.

Xcode - iPhone - profile doesn't match any valid certificate-/private-key pair in the default keychain

your Apple developer certificate might have expired or else ur system date is greater than your account expiry date

Why can't DateTime.Parse parse UTC date

It's not a valid format, however "Tue, 1 Jan 2008 00:00:00 GMT" is.

The documentation says like this:

A string that includes time zone information and conforms to ISO 8601. For example, the first of the following two strings designates the Coordinated Universal Time (UTC); the second designates the time in a time zone seven hours earlier than UTC:

2008-11-01T19:35:00.0000000Z

A string that includes the GMT designator and conforms to the RFC 1123 time format. For example:

Sat, 01 Nov 2008 19:35:00 GMT

A string that includes the date and time along with time zone offset information. For example:

03/01/2009 05:42:00 -5:00

How to launch an application from a browser?

Some applications launches themselves by protocols. like itunes with "itms://" links. I don't know however how you can register that with windows.

Connecting to local SQL Server database using C#

In Data Source (on the left of Visual Studio) right click on the database, then Configure Data Source With Wizard. A new window will appear, expand the Connection string, you can find the connection string in there

dropping a global temporary table

  1. Down the apache server by running below in putty cd $ADMIN_SCRIPTS_HOME ./adstpall.sh
  2. Drop the Global temporary tables drop table t;

This will workout..

UIView's frame, bounds, center, origin, when to use what?

The properties center, bounds and frame are interlocked: changing one will update the others, so use them however you want. For example, instead of modifying the x/y params of frame to recenter a view, just update the center property.

jquery $(window).height() is returning the document height

I think your document must be having enough space in the window to display its contents. That means there is no need to scroll down to see any more part of the document. In that case, document height would be equal to the window height.

How to convert int[] into List<Integer> in Java?

give a try to this class:

class PrimitiveWrapper<T> extends AbstractList<T> {

    private final T[] data;

    private PrimitiveWrapper(T[] data) {
        this.data = data; // you can clone this array for preventing aliasing
    }

    public static <T> List<T> ofIntegers(int... data) {
        return new PrimitiveWrapper(toBoxedArray(Integer.class, data));
    }

    public static <T> List<T> ofCharacters(char... data) {
        return new PrimitiveWrapper(toBoxedArray(Character.class, data));
    }

    public static <T> List<T> ofDoubles(double... data) {
        return new PrimitiveWrapper(toBoxedArray(Double.class, data));
    }  

    // ditto for byte, float, boolean, long

    private static <T> T[] toBoxedArray(Class<T> boxClass, Object components) {
        final int length = Array.getLength(components);
        Object res = Array.newInstance(boxClass, length);

        for (int i = 0; i < length; i++) {
            Array.set(res, i, Array.get(components, i));
        }

        return (T[]) res;
    }

    @Override
    public T get(int index) {
        return data[index];
    }

    @Override
    public int size() {
        return data.length;
    }
}

testcase:

List<Integer> ints = PrimitiveWrapper.ofIntegers(10, 20);
List<Double> doubles = PrimitiveWrapper.ofDoubles(10, 20);
// etc

What is Turing Complete?

Here is the simplest explanation

Alan Turing created a machine that can take a program, run that program, and show some result. But then he had to create different machines for different programs. So he created "Universal Turing Machine" that can take ANY program and run it.

Programming languages are similar to those machines (although virtual). They take programs and run them. Now, a programing language is called "Turing complete", if it can run any program (irrespective of the language) that a Turing machine can run given enough time and memory.

For example: Let's say there is a program that takes 10 numbers and adds them. A Turing machine can easily run this program. But now imagine that for some reason your programming language can't perform the same addition. This would make it "Turing incomplete" (so to speak). On the other hand, if it can run any program that the universal Turing machine can run, then it's Turing complete.

Most modern programming languages (e.g. Java, JavaScript, Perl, etc.) are all Turing complete because they each implement all the features required to run programs like addition, multiplication, if-else condition, return statements, ways to store/retrieve/erase data and so on.

Update: You can learn more on my blog post: "JavaScript Is Turing Complete" — Explained

Windows batch: sleep

I don't know why those commands are not working for you, but you can also try timeout

timeout <delay in seconds>

How do I convert an integer to binary in JavaScript?

This is how I manage to handle it:

const decbin = nbr => {
  if(nbr < 0){
     nbr = 0xFFFFFFFF + nbr + 1
  }
  return parseInt(nbr, 10).toString(2)
};

got it from this link: https://locutus.io/php/math/decbin/

Select value if condition in SQL Server

Try Case

SELECT   stock.name,
      CASE 
         WHEN stock.quantity <20 THEN 'Buy urgent'
         ELSE 'There is enough'
      END
FROM stock

Text file in VBA: Open/Find Replace/SaveAs/Close File

Guess I'm too late...

Came across the same problem today; here is my solution using FileSystemObject:

Dim objFSO
Const ForReading = 1
Const ForWriting = 2
Dim objTS 'define a TextStream object
Dim strContents As String
Dim fileSpec As String

fileSpec = "C:\Temp\test.txt"
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objTS = objFSO.OpenTextFile(fileSpec, ForReading)
strContents = objTS.ReadAll
strContents = Replace(strContents, "XXXXX", "YYYY")
objTS.Close

Set objTS = objFSO.OpenTextFile(fileSpec, ForWriting)
objTS.Write strContents
objTS.Close

keytool error Keystore was tampered with, or password was incorrect

In my case with Xamarin Forms 4.7 and Visual Studio 2019 16.7.0 Preview 3.1, the problem was version mismatch of lately updated Android Build tools (apksigner) and JDK. Updated JDK to latest and pointed the new JDK path on Tools->Options->Xamarin->Android Settings, and it works.

Have nginx access_log and error_log log to STDOUT and STDERR of master process

Edit: it seems nginx now supports error_log stderr; as mentioned in Anon's answer.

You can send the logs to /dev/stdout. In nginx.conf:

daemon off;
error_log /dev/stdout info;

http {
  access_log /dev/stdout;
  ...
}

edit: May need to run ln -sf /proc/self/fd /dev/ if using running certain docker containers, then use /dev/fd/1 or /dev/fd/2

Show Console in Windows Application?

This is a tad old (OK, it's VERY old), but I'm doing the exact same thing right now. Here's a very simple solution that's working for me:

[DllImport("kernel32.dll", SetLastError = true)]
static extern bool AllocConsole();

[DllImport("kernel32.dll")]
static extern IntPtr GetConsoleWindow();

[DllImport("user32.dll")]
static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);

const int SW_HIDE = 0;
const int SW_SHOW = 5;

public static void ShowConsoleWindow()
{
    var handle = GetConsoleWindow();

    if (handle == IntPtr.Zero)
    {
        AllocConsole();
    }
    else
    {
        ShowWindow(handle, SW_SHOW);
    }
}

public static void HideConsoleWindow()
{
    var handle = GetConsoleWindow();
    ShowWindow(handle, SW_HIDE);
}

Two values from one input in python?

I tried this in Python 3 , seems to work fine .

a, b = map(int,input().split())

print(a)

print(b)

Input : 3 44

Output :

3

44

Android: How to add R.raw to project?

The R class is written when you build the project in gradle. You should add the raw folder, then build the project. After that, the R class will be able to identify R.raw.*.

HTTP Error 503, the service is unavailable

I had the same issue for the longest time and I thought there was an issue with my code. Turns out, in the IIS server, my application pool for that particular project was stopped. I turned it back on and that fixed the issue. Error 503 is most likely related to the Application Pool

Php multiple delimiters in explode

function multiexplode ($delimiters,$string) {

    $ready = str_replace($delimiters, $delimiters[0], $string);
    $launch = explode($delimiters[0], $ready);
    return  $launch;
}

$text = "here is a sample: this text, and this will be exploded. this also | this one too :)";


$exploded = multiexplode(array(",",".","|",":"),$text);

print_r($exploded);

//And output will be like this:
// Array
// (
//    [0] => here is a sample
//    [1] =>  this text
//    [2] =>  and this will be exploded
//    [3] =>  this also 
//    [4] =>  this one too 
//    [5] => )
// )

Source: php@metehanarslan at php.net

Converting a string to a date in DB2

You can use:

select VARCHAR_FORMAT(creationdate, 'MM/DD/YYYY') from table name

Html table with button on each row

Put a single listener on the table. When it gets a click from an input with a button that has a name of "edit" and value "edit", change its value to "modify". Get rid of the input's id (they aren't used for anything here), or make them all unique.

<script type="text/javascript">

function handleClick(evt) {
  var node = evt.target || evt.srcElement;
  if (node.name == 'edit') {
    node.value = "Modify";
  }
}

</script>

<table id="table1" border="1" onclick="handleClick(event);">
    <thead>
      <tr>
          <th>Select
    </thead>
    <tbody>
       <tr> 
           <td>
               <form name="f1" action="#" >
                <input id="edit1" type="submit" name="edit" value="Edit">
               </form>
       <tr> 
           <td>
               <form name="f2" action="#" >
                <input id="edit2" type="submit" name="edit" value="Edit">
               </form>
       <tr> 
           <td>
               <form name="f3" action="#" >
                <input id="edit3" type="submit" name="edit" value="Edit">
               </form>

   </tbody>
</table>

ReactJS SyntheticEvent stopPropagation() only works with React events?

I ran into this problem yesterday, so I created a React-friendly solution.

Check out react-native-listener. It's working very well so far. Feedback appreciated.

Installing a pip package from within a Jupyter Notebook not working

Alternative option : you can also create a bash cell in jupyter using bash kernel and then pip install geocoder. That should work

JQuery Parsing JSON array

with parse.JSON

var obj = jQuery.parseJSON( '{ "name": "John" }' );
alert( obj.name === "John" );

Angular 2 Date Input not binding to date value

Angular 2 completely ignores type=date. If you change type to text you'll see that your input has two-way binding.

<input type='text' #myDate [(ngModel)]='demoUser.date'/><br>

Here is pretty bad advise with better one to follow:

My project originally used jQuery. So, I'm using jQuery datepicker for now, hoping that angular team will fix the original issue. Also it's a better replacement because it has cross-browser support. FYI, input=date doesn't work in Firefox.

Good advise: There are few pretty good Angular2 datepickers:

How to move screen without moving cursor in Vim?

Vim requires the cursor to be in the current screen at all times, however, you could bookmark the current position scroll around and then return to where you were.

mg  # This book marks the current position as g (this can be any letter)
<scroll around>
`g  # return to g

Equivalent of jQuery .hide() to set visibility: hidden

An even simpler way to do this is to use jQuery's toggleClass() method

CSS

.newClass{visibility: hidden}

HTML

<a href="#" class=trigger>Trigger Element </a>
<div class="hidden_element">Some Content</div>

JS

$(document).ready(function(){
    $(".trigger").click(function(){
        $(".hidden_element").toggleClass("newClass");
    });
});

Java Switch Statement - Is "or"/"and" possible?

You can use switch-case fall through by omitting the break; statement.

char c = /* whatever */;

switch(c) {
    case 'a':
    case 'A':
        //get the 'A' image;
        break;
    case 'b':
    case 'B':
        //get the 'B' image;
        break;
    // (...)
    case 'z':
    case 'Z':
        //get the 'Z' image;
        break;
}

...or you could just normalize to lower case or upper case before switching.

char c = Character.toUpperCase(/* whatever */);

switch(c) {
    case 'A':
        //get the 'A' image;
        break;
    case 'B':
        //get the 'B' image;
        break;
    // (...)
    case 'Z':
        //get the 'Z' image;
        break;
}

Is there a "theirs" version of "git merge -s ours"?

I used the answer from Paul Pladijs since now. I found out, you can do a "normal" merge, conflicts occur, so you do

git checkout --theirs <file>

to resolve the conflict by using the revision from the other branch. If you do this for each file, you have the same behaviour as you would expect from

git merge <branch> -s theirs

Anyway, the effort is more than it would be with the merge-strategy! (This was tested with git version 1.8.0)

How do you split a list into evenly sized chunks?

def chunk(input, size):
    return map(None, *([iter(input)] * size))

dyld: Library not loaded: /usr/local/lib/libpng16.16.dylib with anything php related

I got this problem after updating MAMP, and the custom $PATH I had set was wrong because of the new php version, so the wrong version of php was loaded first, and it was that version of php that triggered the error.

Updating the path in my .bash_profile fixed my issue.

How can I wait for set of asynchronous callback functions?

Checking in from 2015: We now have native promises in most recent browser (Edge 12, Firefox 40, Chrome 43, Safari 8, Opera 32 and Android browser 4.4.4 and iOS Safari 8.4, but not Internet Explorer, Opera Mini and older versions of Android).

If we want to perform 10 async actions and get notified when they've all finished, we can use the native Promise.all, without any external libraries:

function asyncAction(i) {
    return new Promise(function(resolve, reject) {
        var result = calculateResult();
        if (result.hasError()) {
            return reject(result.error);
        }
        return resolve(result);
    });
}

var promises = [];
for (var i=0; i < 10; i++) {
    promises.push(asyncAction(i));
}

Promise.all(promises).then(function AcceptHandler(results) {
    handleResults(results),
}, function ErrorHandler(error) {
    handleError(error);
});

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

I would recommend doing it like this to keep things in line with HTML5.

<meta charset="UTF-8">

EG:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
</body>
</html>

How to compile and run C files from within Notepad++ using NppExec plugin?

Here is the code for compling and running java source code: - Open Notepadd++ - Hit F6 - Paste this code

npp_save <-- Saves the current document
CD $(CURRENT_DIRECTORY) <-- Moves to the current directory
javac "$(FILE_NAME)" <-- compiles your file named *.java
java "$(NAME_PART)" <-- executes the program

The Java Classpath variable has to be set for this...

Another useful site: http://www.scribd.com/doc/52238931/Notepad-Tutorial-Compile-and-Run-Java-Program

PHP Foreach Arrays and objects

Recursive traverse object or array with array or objects elements:

function traverse(&$objOrArray)
{
    foreach ($objOrArray as $key => &$value)
    {
        if (is_array($value) || is_object($value))
        {
            traverse($value);
        }
        else
        {
            // DO SOMETHING
        }
    }
}

Adding values to Arraylist

in the first you don't define the type that will be held and linked within your arraylist construct

this is the preferred method to do so, you define the type of list and the ide will handle the rest

in the third one you will better just define List for shorter code

How to delete files older than X hours

If you do not have "-mmin" in your version of "find", then "-mtime -0.041667" gets pretty close to "within the last hour", so in your case, use:

-mtime +(X * 0.041667)

so, if X means 6 hours, then:

find . -mtime +0.25 -ls

works because 24 hours * 0.25 = 6 hours

Rotating and spacing axis labels in ggplot2

I'd like to provide an alternate solution, a robust solution similar to what I am about to propose was required in the latest version of ggtern, since introducing the canvas rotation feature.

Basically, you need to determine the relative positions using trigonometry, by building a function which returns an element_text object, given angle (ie degrees) and positioning (ie one of x,y,top or right) information.

#Load Required Libraries
library(ggplot2)
library(gridExtra)

#Build Function to Return Element Text Object
rotatedAxisElementText = function(angle,position='x'){
  angle     = angle[1]; 
  position  = position[1]
  positions = list(x=0,y=90,top=180,right=270)
  if(!position %in% names(positions))
    stop(sprintf("'position' must be one of [%s]",paste(names(positions),collapse=", ")),call.=FALSE)
  if(!is.numeric(angle))
    stop("'angle' must be numeric",call.=FALSE)
  rads  = (angle - positions[[ position ]])*pi/180
  hjust = 0.5*(1 - sin(rads))
  vjust = 0.5*(1 + cos(rads))
  element_text(angle=angle,vjust=vjust,hjust=hjust)
}

Frankly, in my opinion, I think that an 'auto' option should be made available in ggplot2 for the hjust and vjust arguments, when specifying the angle, anyway, lets demonstrate how the above works.

#Demonstrate Usage for a Variety of Rotations
df    = data.frame(x=0.5,y=0.5)
plots = lapply(seq(0,90,length.out=4),function(a){
  ggplot(df,aes(x,y)) + 
    geom_point() + 
    theme(axis.text.x = rotatedAxisElementText(a,'x'),
          axis.text.y = rotatedAxisElementText(a,'y')) +
    labs(title = sprintf("Rotated %s",a))
})
grid.arrange(grobs=plots)

Which produces the following:

Example

MySQL vs MySQLi when using PHP

What is better is PDO; it's a less crufty interface and also provides the same features as MySQLi.

Using prepared statements is good because it eliminates SQL injection possibilities; using server-side prepared statements is bad because it increases the number of round-trips.

What does 'public static void' mean in Java?

It means three things.

First public means that any other object can access it.

static means that the class in which it resides doesn't have to be instantiated first before the function can be called.

void means that the function does not return a value.

Since you are just learning, don't worry about the first two too much until you learn about classes, and the third won't matter much until you start writing functions (other than main that is).

Best piece of advice I got when learning to program, and which I pass along to you, is don't worry about the little details you don't understand right away. Get a broad overview of the fundamentals, then go back and worry about the details. The reason is that you have to use some things (like public static void) in your first programs which can't really be explained well without teaching you about a bunch of other stuff first. So, for the moment, just accept that that's the way it's done, and move on. You will understand them shortly.

JUNIT testing void methods

You can still unit test a void method by asserting that it had the appropriate side effect. In your method1 example, your unit test might look something like:

public void checkIfValidElementsWithDollarSign() {
    checkIfValidElement("$",19);
    assert ErrorFile.errorMessages.contains("There is a dollar sign in the specified parameter");
}

Nesting optgroups in a dropdownlist/select

I think if you have something that structured and complex, you might consider something other than a single drop-down box.

How to detect browser using angularjs?

There is a library ng-device-detector which makes detecting entities like browser, os easy.

Here is tutorial that explains how to use this library. Detect OS, browser and device in AngularJS

ngDeviceDetector

You need to add re-tree.js and ng-device-detector.js scripts into your html

Inject "ng.deviceDetector" as dependency in your module.

Then inject "deviceDetector" service provided by the library into your controller or factory where ever you want the data.

"deviceDetector" contains all data regarding browser, os and device.

How to launch an EXE from Web page (asp.net)

Are you saying that you are having trouble inserting into a web page a link to a file that happens to have a .exe extension?

If that is the case, then take one step back. Imagine the file has a .htm extension, or a .css extension. How can you make that downloadable? If it is a static link, then the answer is clear: the file needs to be in the docroot for the ASP.NET app. IIS + ASP.NET serves up many kinds of content: .htm files, .css files, .js files, image files, implicitly. All these files are somewhere under the docroot, which by default is c:\inetpub\wwwroot, but for your webapp is surely something different. The fact that the file you want to expose has an .exe extension does not change the basic laws of IIS physics. The exe has to live under the docroot. The network share thing might work for some browsers.

The alternative of course is to dynamically write the content of the file directly to the Response.OutputStream. This way you don't need the .exe to be in your docroot, but it is not a direct download link. In this scenario, the file might be downloaded by a button click.

Something like this:

    Response.Clear(); 
    string FullPathFilename = "\\\\server\\share\\CorpApp1.exe";
    string archiveName= System.IO.Path.GetFileName(FullPathFilename);
    Response.ContentType = "application/octet-stream";
    Response.AddHeader("content-disposition", "filename=" + archiveName);
    Response.TransmitFile(FullPathFilename);
    Response.End();

Can't clone a github repo on Linux via HTTPS

The answer was simple but not obvious:

Instead of:

git clone https://github.com/org/project.git

do:

git clone https://[email protected]/org/project.git

or (insecure)

git clone https://username:[email protected]/org/project.git

(Note that in the later case, your password will may be visible by other users on your machine by running ps u -u $you and will appear cleartext in your shell's history by default)

All 3 ways work on my Mac, but only the last 2 worked on the remote Linux box. (Thinking back on this, it's probably because I had a global git username set up on my Mac, whereas on the remote box I did not? That might have been the case, but the lack of prompt for a username tripped me up... )

Haven't seen this documented anywhere, so here it is.

Angles between two n-dimensional vectors in Python

Using numpy and taking care of BandGap's rounding errors:

from numpy.linalg import norm
from numpy import dot
import math

def angle_between(a,b):
  arccosInput = dot(a,b)/norm(a)/norm(b)
  arccosInput = 1.0 if arccosInput > 1.0 else arccosInput
  arccosInput = -1.0 if arccosInput < -1.0 else arccosInput
  return math.acos(arccosInput)

Note, this function will throw an exception if one of the vectors has zero magnitude (divide by 0).

How to convert JSON to XML or XML to JSON?

I searched for a long time to find alternative code to the accepted solution in the hopes of not using an external assembly/project. I came up with the following thanks to the source code of the DynamicJson project:

public XmlDocument JsonToXML(string json)
{
    XmlDocument doc = new XmlDocument();

    using (var reader = JsonReaderWriterFactory.CreateJsonReader(Encoding.UTF8.GetBytes(json), XmlDictionaryReaderQuotas.Max))
    {
        XElement xml = XElement.Load(reader);
        doc.LoadXml(xml.ToString());
    }

    return doc;
}

Note: I wanted an XmlDocument rather than an XElement for xPath purposes. Also, this code obviously only goes from JSON to XML, there are various ways to do the opposite.

Javascript array value is undefined ... how do I test for that

predQuery[preId]=='undefined'

You're testing against the string 'undefined'; you've confused this test with the typeof test which would return a string. You probably mean to be testing against the special value undefined:

predQuery[preId]===undefined

Note the strict-equality operator to avoid the generally-unwanted match null==undefined.

However there are two ways you can get an undefined value: either preId isn't a member of predQuery, or it is a member but has a value set to the special undefined value. Often, you only want to check whether it's present or not; in that case the in operator is more appropriate:

!(preId in predQuery)

unknown error: Chrome failed to start: exited abnormally (Driver info: chromedriver=2.9

I finally managed to get Selenium tests starting the Chrome Driver on my laptop (server).

The important bit is to use Xvfb. Don't ask me why but once you accept this fact follow these steps (more detailed than @Anon answer)

  • In you Jenkins settings add a global property

    key : DISPLAY
    value:0:0
    
  • On your server start Xvfb in the background:

     Xvfb :0 -ac -screen 0 1024x768x24 &
    

Maven command to determine which settings.xml file Maven is using

Start maven with -X option (debug) and examine the beginning of the output. There should be something like this:

...
[INFO] Error stacktraces are turned on.
[DEBUG] Reading global settings from c:\....\apache-maven-3.0.3\conf\settings.xml
[DEBUG] Reading user settings from c:\....\.m2\settings.xml
[DEBUG] Using local repository at C:\....\repository
...

(Original directory names are removed by me)

How can I ping a server port with PHP?

Try this :

echo exec('ping -n 1 -w 1 72.10.169.28');

Removing multiple classes (jQuery)

There are many ways can do that!

jQuery

  1. remove all class
    $("element").removeClass();
    OR
    $("#item").removeAttr('class');
    OR
    $("#item").attr('class', '');
    OR
    $('#item')[0].className = '';

  2. remove multi class
    $("element").removeClass("class1 ... classn");
    OR
    $("element").removeClass("class1").removeClass("...").removeClass("classn");

Vanilla Javascript

  1. remove all class

_x000D_
_x000D_
// remove all items all class  _x000D_
const items = document.querySelectorAll('item');_x000D_
for (let i = 0; i < items.length; i++) {_x000D_
    items[i].className = '';_x000D_
}
_x000D_
_x000D_
_x000D_

  1. remove multi class

_x000D_
_x000D_
// only remove all class of first item_x000D_
const item1 = document.querySelector('item');_x000D_
item1.className = '';
_x000D_
_x000D_
_x000D_

Count length of array and return 1 if it only contains one element

Instead of writing echo $cars.length write echo @($cars).length

Regular Expression: Any character that is NOT a letter or number

This regular expression matches anything that isn't a letter, digit, or an underscore (_) character.

\W

For example in JavaScript:

"(,,@,£,() asdf 345345".replace(/\W/g, ' '); // Output: "          asdf 345345"

Selecting distinct values from a JSON

Use Jquery Method unique.

var UniqueNames= $.unique(data.DATA.map(function (d) {return d.name;}));

alert($.unique(names));

JSFiddle

Notepad++ change text color?

You can Change it from:

Menu Settings -> Style Configurator

See on screenshot:

enter image description here

How to create NSIndexPath for TableView

Use [NSIndexPath indexPathForRow:inSection:] to quickly create an index path.

Edit: In Swift 3:

let indexPath = IndexPath(row: rowIndex, section: sectionIndex)

Swift 5

IndexPath(row: 0, section: 0)

Convert javascript object or array to json for ajax data

I'm not entirely sure but I think you are probably surprised at how arrays are serialized in JSON. Let's isolate the problem. Consider following code:

var display = Array();
display[0] = "none";
display[1] = "block";
display[2] = "none";

console.log( JSON.stringify(display) );

This will print:

["none","block","none"]

This is how JSON actually serializes array. However what you want to see is something like:

{"0":"none","1":"block","2":"none"}

To get this format you want to serialize object, not array. So let's rewrite above code like this:

var display2 = {};
display2["0"] = "none";
display2["1"] = "block";
display2["2"] = "none";

console.log( JSON.stringify(display2) );

This will print in the format you want.

You can play around with this here: http://jsbin.com/oDuhINAG/1/edit?js,console

CSS div element - how to show horizontal scroll bars only?

To show both:

<div style="height:250px; width:550px; overflow-x:scroll ; overflow-y: scroll; padding-bottom:10px;">      </div>

Hide X Axis:

<div style="height:250px; width:550px; overflow-x:hidden; overflow-y: scroll; padding-bottom:10px;">      </div>

Hide Y Axis:

<div style="height:250px; width:550px; overflow-x:scroll ; overflow-y: hidden; padding-bottom:10px;">      </div>

How do I check if a C++ std::string starts with a certain string, and convert a substring to an int?

With C++17 you can use std::basic_string_view & with C++20 std::basic_string::starts_with or std::basic_string_view::starts_with.

The benefit of std::string_view in comparison to std::string - regarding memory management - is that it only holds a pointer to a "string" (contiguous sequence of char-like objects) and knows its size. Example without moving/copying the source strings just to get the integer value:

#include <exception>
#include <iostream>
#include <string>
#include <string_view>

int main()
{
    constexpr auto argument = "--foo=42"; // Emulating command argument.
    constexpr auto prefix = "--foo=";
    auto inputValue = 0;

    constexpr auto argumentView = std::string_view(argument);
    if (argumentView.starts_with(prefix))
    {
        constexpr auto prefixSize = std::string_view(prefix).size();
        try
        {
            // The underlying data of argumentView is nul-terminated, therefore we can use data().
            inputValue = std::stoi(argumentView.substr(prefixSize).data());
        }
        catch (std::exception & e)
        {
            std::cerr << e.what();
        }
    }
    std::cout << inputValue; // 42
}

How do you dynamically allocate a matrix?

or you can just allocate a 1D array but reference elements in a 2D fashion:

to address row 2, column 3 (top left corner is row 0, column 0):

arr[2 * MATRIX_WIDTH + 3]

where MATRIX_WIDTH is the number of elements in a row.

Scraping html tables into R data frames using the XML package

Another option using Xpath.

library(RCurl)
library(XML)

theurl <- "http://en.wikipedia.org/wiki/Brazil_national_football_team"
webpage <- getURL(theurl)
webpage <- readLines(tc <- textConnection(webpage)); close(tc)

pagetree <- htmlTreeParse(webpage, error=function(...){}, useInternalNodes = TRUE)

# Extract table header and contents
tablehead <- xpathSApply(pagetree, "//*/table[@class='wikitable sortable']/tr/th", xmlValue)
results <- xpathSApply(pagetree, "//*/table[@class='wikitable sortable']/tr/td", xmlValue)

# Convert character vector to dataframe
content <- as.data.frame(matrix(results, ncol = 8, byrow = TRUE))

# Clean up the results
content[,1] <- gsub(" ", "", content[,1])
tablehead <- gsub(" ", "", tablehead)
names(content) <- tablehead

Produces this result

> head(content)
   Opponent Played Won Drawn Lost Goals for Goals against % Won
1 Argentina     94  36    24   34       148           150 38.3%
2  Paraguay     72  44    17   11       160            61 61.1%
3   Uruguay     72  33    19   20       127            93 45.8%
4     Chile     64  45    12    7       147            53 70.3%
5      Peru     39  27     9    3        83            27 69.2%
6    Mexico     36  21     6    9        69            34 58.3%

Replace one substring for another string in shell script

echo [string] | sed "s/[original]/[target]/g"
  • "s" means "substitute"
  • "g" means "global, all matching occurrences"

how to set value of a input hidden field through javascript?

Your code for setting value for hidden input is correct. Here is the example. Maybe you have some conditions in your if statements that are not allowing your scripts to execute.

PostgreSQL: insert from another table

You could use coalesce:

insert into destination select coalesce(field1,'somedata'),... from source;

Android device chooser - My device seems offline

I had a similar problem in Android Studio 0.2.2 (IntelliJ). On Windows 7 my Nexus 7 did not appear in device chooser although it was fine on my Mac. I could also browse my Nexus 7 in Windows Explorer.

In the end I needed to install the Asus USB drivers for the Nexus 7 (link):

After that ADB detected my Nexus and everything worked as expected.

C++ Returning reference to local variable

This code snippet:

int& func1()
{
    int i;
    i = 1;
    return i;
}

will not work because you're returning an alias (a reference) to an object with a lifetime limited to the scope of the function call. That means once func1() returns, int i dies, making the reference returned from the function worthless because it now refers to an object that doesn't exist.

int main()
{
    int& p = func1();
    /* p is garbage */
}

The second version does work because the variable is allocated on the free store, which is not bound to the lifetime of the function call. However, you are responsible for deleteing the allocated int.

int* func2()
{
    int* p;
    p = new int;
    *p = 1;
    return p;
}

int main()
{
    int* p = func2();
    /* pointee still exists */
    delete p; // get rid of it
}

Typically you would wrap the pointer in some RAII class and/or a factory function so you don't have to delete it yourself.

In either case, you can just return the value itself (although I realize the example you provided was probably contrived):

int func3()
{
    return 1;
}

int main()
{
    int v = func3();
    // do whatever you want with the returned value
}

Note that it's perfectly fine to return big objects the same way func3() returns primitive values because just about every compiler nowadays implements some form of return value optimization:

class big_object 
{ 
public:
    big_object(/* constructor arguments */);
    ~big_object();
    big_object(const big_object& rhs);
    big_object& operator=(const big_object& rhs);
    /* public methods */
private:
    /* data members */
};

big_object func4()
{
    return big_object(/* constructor arguments */);
}

int main()
{
     // no copy is actually made, if your compiler supports RVO
    big_object o = func4();    
}

Interestingly, binding a temporary to a const reference is perfectly legal C++.

int main()
{
    // This works! The returned temporary will last as long as the reference exists
    const big_object& o = func4();    
    // This does *not* work! It's not legal C++ because reference is not const.
    // big_object& o = func4();  
}

ASP.NET Web Site or ASP.NET Web Application?

Web Site is what you deploy to an ASP.NET web server such as IIS. Just a bunch of files and folders. There’s nothing in a Web Site that ties you to Visual Studio (there’s no project file). Code-generation and compilation of web pages (such as .aspx, .ascx, .master) is done dynamically at runtime, and changes to these files are detected by the framework and automatically re-compiled. You can put code that you want to share between pages in the special App_Code folder, or you can pre-compile it and put the assembly in the Bin folder.

Web Application is a special Visual Studio project. The main difference with Web Sites is that when you build the project all the code files are compiled into a single assembly, which is placed in the bin directory. You don’t deploy code files to the web server. Instead of having a special folder for shared code files you can put them anywhere, just like you would do in class library. Because Web Applications contains files that are not meant to be deployed, such as project and code files, there’s a Publish command in Visual Studio to output a Web Site to a specified location.

App_Code vs Bin

Deploying shared code files is generally a bad idea, but that doesn’t mean you have to choose Web Application. You can have a Web Site that references a class library project that holds all the code for the Web Site. Web Applications is just a convenient way to do it.

CodeBehind

This topic is specific to .aspx and .ascx files. This topic is decreasingly relevant in new application frameworks such as ASP.NET MVC and ASP.NET Web Pages which do not use codebehind files.

By having all code files compiled into a single assembly, including codebehind files of .aspx pages and .ascx controls, in Web Applications you have to re-build for every little change, and you cannot make live changes. This can be a real pain during development, since you have to keep re-building to see the changes, while with Web Sites changes are detected by the runtime and pages/controls are automatically recompiled.

Having the runtime manage the codebehind assemblies is less work for you, since you don't need to worry about giving pages/controls unique names, or organizing them into different namespaces.

I’m not saying deploying code files is always a good idea (specially not in the case of shared code files), but codebehind files should only contain code that perform UI specific tasks, wire-up events handlers, etc. Your application should be layered so that important code always end up in the Bin folder. If that is the case then deploying codebehind files shouldn't be considered harmful.

Another limitation of Web Applications is that you can only use the language of the project. In Web Sites you can have some pages in C#, some in VB, etc. No need for special Visual Studio support. That’s the beauty of the build provider extensibility.

Also, in Web Applications you don't get error detection in pages/controls as the compiler only compiles your codebehind classes and not the markup code (in MVC you can fix this using the MvcBuildViews option), which is compiled at runtime.

Visual Studio

Because Web Applications are Visual Studio projects you get some features not available in Web Sites. For instance, you can use build events to perform a variety of tasks, e.g. minify and/or combine Javascript files.

Another nice feature introduced in Visual Studio 2010 is Web.config transformation. This is also not available in Web Sites. Now works with Web Sites in VS 2013.

Building a Web Application is faster than building a Web Site, specially for large sites. This is mainly because Web Applications do not compile the markup code. In MVC if you set MvcBuildViews to true then it compiles the markup code and you get error detection, which is very useful. The down side is that every time you build the solution it builds the complete site, which can be slow and inefficient, specially if you are not editing the site. l find myself turning MvcBuildViews on and off (which requires a project unload). On the other hand, with Web Sites you can choose if you want to build the site as part of the solution or not. If you choose not to, then building the solution is very fast, and you can always click on the Web Site node and select Build, if you’ve made changes.

In an MVC Web Application project you have extra commands and dialogs for common tasks, like ‘Add View’, ‘Go To View’, ‘Add Controller’, etc. These are not available in an MVC Web Site.

If you use IIS Express as the development server, in Web Sites you can add virtual directories. This option is not available in Web Applications.

NuGet Package Restore does not work on Web Sites, you have to manually install packages listed on packages.config Package Restore now works with Web Sites starting NuGet 2.7

How to create a drop shadow only on one side of an element?

How about just using a containing div which has overflow set to hidden and some padding at the bottom? This seems like much the simplest solution.

Sorry to say I didn't think of this myself but saw it somewhere else.

Using an element to wrap the element getting the box-shadow and a overflow: hidden on the wrapper you could make the extra box-shadow disappear and still have a usable border. This also fixes the problem where the element is smaller as it seems, because of the spread.

Like this:

#wrapper { padding-bottom: 10px; overflow: hidden; }
#elem { box-shadow: 0 0 10px black; }

Content goes here

Still a clever solution when it has to be done in pure CSS!

As said by Jorgen Evens.

how can I enable scrollbars on the WPF Datagrid?

Adding MaxHeight and VerticalScrollBarVisibility="Auto" on the DataGrid solved my problem.

multiple figure in latex with captions

Below is an example of multiple figures that I used recently in Latex. You need to call these packages

\usepackage{graphicx}
\usepackage{subfig})


\begin{figure}[H]%

    \centering

    \subfloat[Row1]{{\includegraphics[scale=.36]{1.png} }}%

    \subfloat[Row2]{{\includegraphics[scale=.36]{2.png} }}%

    \subfloat[Row3]{{\includegraphics[scale=.36]{3.png} }}%
    \hfill
    \subfloat[Row4]{{\includegraphics[scale=0.37]{4.png} }}%

    \subfloat[Row5]{{\includegraphics[scale=0.37]{5.png} }}%

    \caption{Multiple figures in latex.}%

    \label{fig:MFL}%

\end{figure}

How do I convert seconds to hours, minutes and seconds?

If you need to get datetime.time value, you can use this trick:

my_time = (datetime(1970,1,1) + timedelta(seconds=my_seconds)).time()

You cannot add timedelta to time, but can add it to datetime.

UPD: Yet another variation of the same technique:

my_time = (datetime.fromordinal(1) + timedelta(seconds=my_seconds)).time()

Instead of 1 you can use any number greater than 0. Here we use the fact that datetime.fromordinal will always return datetime object with time component being zero.

How to undo last commit

Warning: Don't do this if you've already pushed

You want to do:

git reset HEAD~

If you don't want the changes and blow everything away:

git reset --hard HEAD~

jQuery same click event for multiple elements

I have a link to an object containig many input fields, which requires to be handled by the same event. So I simply use find() to get all the inside objects, that need to have the event

var form = $('<form></form>');
// ... apending several input fields

form.find('input').on('change', onInputChange);

In case your objects are one level down the link children() instead find() method can be used.

Set value to currency in <input type="number" />

You guys are completely right numbers can only go in the numeric field. I use the exact same thing as already listed with a bit of css styling on a span tag:

<span>$</span><input type="number" min="0.01" step="0.01" max="2500" value="25.67">

Then add a bit of styling magic:

span{
  position:relative;
  margin-right:-20px
}
input[type='number']{
  padding-left:20px;
  text-align:left;
}

What bitrate is used for each of the youtube video qualities (360p - 1080p), in regards to flowplayer?

Looking at this official google link: Youtube Live encoder settings, bitrates and resolutions they have this table:

                   240p       360p        480p        720p        1080p
Resolution      426 x 240   640 x 360   854x480     1280x720    1920x1080
Video Bitrates                   
Maximum         700 Kbps    1000 Kbps   2000 Kbps   4000 Kbps   6000 Kbps
Recommended     400 Kbps    750 Kbps    1000 Kbps   2500 Kbps   4500 Kbps
Minimum         300 Kbps    400 Kbps    500 Kbps    1500 Kbps   3000 Kbps

It would appear as though this is the case, although the numbers dont sync up to the google table above:

// the bitrates, video width and file names for this clip
      bitrates: [
        { url: "bbb-800.mp4", width: 480, bitrate: 800 }, //360p video
        { url: "bbb-1200.mp4", width: 720, bitrate: 1200 }, //480p video
        { url: "bbb-1600.mp4", width: 1080, bitrate: 1600 } //720p video
      ],

How to start/stop/restart a thread in Java?

You can't restart a thread so your best option is to save the current state of the object at the time the thread was stopped and when operations need to continue on that object you can recreate that object using the saved and then start the new thread.

These two articles Swing Worker and Concurrency may help you determine the best solution for your problem.

Calculate time difference in Windows batch file

CMD doesn't have time arithmetic. The following code, however gives a workaround:

set vid_time=11:07:48
set srt_time=11:16:58

REM Get time difference
set length=%vid_time%
for /f "tokens=1-3 delims=:" %i in ("%length%") do (
set /a h=%i*3600
set /a m=%j*60
set /a s=%k
)
set /a t1=!h!+!m!+!s!

set length=%srt_time%
for /f "tokens=1-3 delims=:" %i in ("%length%") do (
set /a h=%i*3600
set /a m=%j*60
set /a s=%k
)
set /a t2=!h!+!m!+!s!
cls
set /a diff=!t2!-!t1!

Above code gives difference in seconds. To display in hh:mm:ss format, code below:

set ss=!diff!
set /a hh=!ss!/3600 >nul
set /a mm="(!ss!-3600*!hh!)/60" >nul
set /a ss="(!ss!-3600*!hh!)-!mm!*60" >nul
set "hh=0!hh!" & set "mm=0!mm!" & set "ss=0!ss!"
echo|set /p=!hh:~-2!:!mm:~-2!:!ss:~-2! 

background-size in shorthand background property (CSS3)

  1. Your jsfiddle uses background-image instead of background
  2. It seems to be a case of "not supported by this browser yet".

This works in Opera : http://jsfiddle.net/ZNsbU/5/
But it doesn't work in FF5 nor IE8. (yay for outdated browsers :D )

Code :

body {
  background:url(http://www.google.com/intl/en_com/images/srpr/logo3w.png) 400px 200px / 600px 400px no-repeat;
}

You could do it like this :

body {
    background:url(http://www.google.com/intl/en_com/images/srpr/logo3w.png) 400px 400px no-repeat;
    background-size:20px 20px
}

Which works in FF5 and Opera but not in IE8.

Label axes on Seaborn Barplot

You can also set the title of your chart by adding the title parameter as follows

ax.set(xlabel='common xlabel', ylabel='common ylabel', title='some title')

What is size_t in C?

The manpage for types.h says:

size_t shall be an unsigned integer type

Math constant PI value in C

In C Pi is defined in math.h: #define M_PI 3.14159265358979323846

selecting rows with id from another table

SELECT terms.*
FROM terms JOIN terms_relation ON id=term_id
WHERE taxonomy='categ'

How to loop backwards in python?

All of these three solutions give the same results if the input is a string:

1.

def reverse(text):
    result = ""
    for i in range(len(text),0,-1):
        result += text[i-1]
    return (result)

2.

text[::-1]

3.

"".join(reversed(text))

Cannot access a disposed object - How to fix?

because the solution folder was inside OneDrive folder.

If you moving the solution folders out of the one drive folder made the errors go away.

best

ByRef argument type mismatch in Excel VBA

It looks like ByRef needs to know the size of the parameter. A declaration of Dim last_name as string doesn't specify the size of the string so it takes it as an error. Before using Worksheets(data_sheet).Range("C2").Value = ProcessString(last_name) The last_name has to be declared as Dim last_name as string *10 ' size of string is up to you but must be a fix length

No need to change the function. Function doesn't take a fix length declaration.

Python Serial: How to use the read or readline function to read more than 1 character at a time

I was reciving some date from my arduino uno (0-1023 numbers). Using code from 1337holiday, jwygralak67 and some tips from other sources:

import serial
import time

ser = serial.Serial(
    port='COM4',\
    baudrate=9600,\
    parity=serial.PARITY_NONE,\
    stopbits=serial.STOPBITS_ONE,\
    bytesize=serial.EIGHTBITS,\
        timeout=0)

print("connected to: " + ser.portstr)

#this will store the line
seq = []
count = 1

while True:
    for c in ser.read():
        seq.append(chr(c)) #convert from ANSII
        joined_seq = ''.join(str(v) for v in seq) #Make a string from array

        if chr(c) == '\n':
            print("Line " + str(count) + ': ' + joined_seq)
            seq = []
            count += 1
            break


ser.close()

Set width to match constraints in ConstraintLayout

For making your view as match_parent is not possible directly, but we can do it in a little different way, but don't forget to use Left and Right attribute with Start and End, coz if you use RTL support, it will be needed.

    <Button
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"/>

Display all dataframe columns in a Jupyter Python Notebook

you can use pandas.set_option(), for column, you can specify any of these options

pd.set_option("display.max_rows", 200)
pd.set_option("display.max_columns", 100)
pd.set_option("display.max_colwidth", 200)

For full print column, you can use like this

import pandas as pd
pd.set_option('display.max_colwidth', -1)
print(words.head())

enter image description here

How to convert An NSInteger to an int?

Ta da:

NSInteger myInteger = 42;
int myInt = (int) myInteger;

NSInteger is nothing more than a 32/64 bit int. (it will use the appropriate size based on what OS/platform you're running)

How to convert 'binary string' to normal string in Python3?

If the answer from falsetru didn't work you could also try:

>>> b'a string'.decode('utf-8')
'a string'

How to get file extension from string in C++

I've stumbled onto this question today myself, even though I already had a working code I figured out that it wouldn't work in some cases.

While some people already suggested using some external libraries, I prefer to write my own code for learning purposes.

Some answers included the method I was using in the first place (looking for the last "."), but I remembered that on linux hidden files/folders start with ".". So if file file is hidden and has no extension, the whole file name would be taken for extension. To avoid that I wrote this piece of code:

bool getFileExtension(const char * dir_separator, const std::string & file, std::string & ext)
{
    std::size_t ext_pos = file.rfind(".");
    std::size_t dir_pos = file.rfind(dir_separator);

    if(ext_pos>dir_pos+1)
    {
        ext.append(file.begin()+ext_pos,file.end());
        return true;
    }

    return false;
}

I haven't tested this fully, but I think that it should work.

Vue.js redirection to another page

When inside a component script tag you can use the router and do something like this

this.$router.push('/url-path')

How to add a custom HTTP header to every WCF call?

If I understand your requirement correctly, the simple answer is: you can't.

That's because the client of the WCF service may be generated by any third party that uses your service.

IF you have control of the clients of your service, you can create a base client class that add the desired header and inherit the behavior on the worker classes.

Trigger Change event when the Input value changed programmatically?

You are using jQuery, right? Separate JavaScript from HTML.

You can use trigger or triggerHandler.

var $myInput = $('#changeProgramatic').on('change', ChangeValue);

var anotherFunction = function() {
  $myInput.val('Another value');
  $myInput.trigger('change');
};

Angular2 @Input to a property with get/set

You could set the @Input on the setter directly, as described below:

_allowDay: boolean;
get allowDay(): boolean {
    return this._allowDay;
}
@Input() set allowDay(value: boolean) {
    this._allowDay = value;
    this.updatePeriodTypes();
}

See this Plunkr: https://plnkr.co/edit/6miSutgTe9sfEMCb8N4p?p=preview.

How to read/write arbitrary bits in C/C++

Some 2+ years after I asked this question I'd like to explain it the way I'd want it explained back when I was still a complete newb and would be most beneficial to people who want to understand the process.

First of all, forget the "11111111" example value, which is not really all that suited for the visual explanation of the process. So let the initial value be 10111011 (187 decimal) which will be a little more illustrative of the process.

1 - how to read a 3 bit value starting from the second bit:

    ___  <- those 3 bits
10111011 

The value is 101, or 5 in decimal, there are 2 possible ways to get it:

  • mask and shift

In this approach, the needed bits are first masked with the value 00001110 (14 decimal) after which it is shifted in place:

    ___
10111011 AND
00001110 =
00001010 >> 1 =
     ___
00000101

The expression for this would be: (value & 14) >> 1

  • shift and mask

This approach is similar, but the order of operations is reversed, meaning the original value is shifted and then masked with 00000111 (7) to only leave the last 3 bits:

    ___
10111011 >> 1
     ___
01011101 AND
00000111
00000101

The expression for this would be: (value >> 1) & 7

Both approaches involve the same amount of complexity, and therefore will not differ in performance.

2 - how to write a 3 bit value starting from the second bit:

In this case, the initial value is known, and when this is the case in code, you may be able to come up with a way to set the known value to another known value which uses less operations, but in reality this is rarely the case, most of the time the code will know neither the initial value, nor the one which is to be written.

This means that in order for the new value to be successfully "spliced" into byte, the target bits must be set to zero, after which the shifted value is "spliced" in place, which is the first step:

    ___ 
10111011 AND
11110001 (241) =
10110001 (masked original value)

The second step is to shift the value we want to write in the 3 bits, say we want to change that from 101 (5) to 110 (6)

     ___
00000110 << 1 =
    ___
00001100 (shifted "splice" value)

The third and final step is to splice the masked original value with the shifted "splice" value:

10110001 OR
00001100 =
    ___
10111101

The expression for the whole process would be: (value & 241) | (6 << 1)

Bonus - how to generate the read and write masks:

Naturally, using a binary to decimal converter is far from elegant, especially in the case of 32 and 64 bit containers - decimal values get crazy big. It is possible to easily generate the masks with expressions, which the compiler can efficiently resolve during compilation:

  • read mask for "mask and shift": ((1 << fieldLength) - 1) << (fieldIndex - 1), assuming that the index at the first bit is 1 (not zero)
  • read mask for "shift and mask": (1 << fieldLength) - 1 (index does not play a role here since it is always shifted to the first bit
  • write mask : just invert the "mask and shift" mask expression with the ~ operator

How does it work (with the 3bit field beginning at the second bit from the examples above)?

00000001 << 3
00001000  - 1
00000111 << 1
00001110  ~ (read mask)
11110001    (write mask)

The same examples apply to wider integers and arbitrary bit width and position of the fields, with the shift and mask values varying accordingly.

Also note that the examples assume unsigned integer, which is what you want to use in order to use integers as portable bit-field alternative (regular bit-fields are in no way guaranteed by the standard to be portable), both left and right shift insert a padding 0, which is not the case with right shifting a signed integer.

Even easier:

Using this set of macros (but only in C++ since it relies on the generation of member functions):

#define GETMASK(index, size) ((((size_t)1 << (size)) - 1) << (index))
#define READFROM(data, index, size) (((data) & GETMASK((index), (size))) >> (index))
#define WRITETO(data, index, size, value) ((data) = (((data) & (~GETMASK((index), (size)))) | (((value) << (index)) & (GETMASK((index), (size))))))
#define FIELD(data, name, index, size) \
  inline decltype(data) name() const { return READFROM(data, index, size); } \
  inline void set_##name(decltype(data) value) { WRITETO(data, index, size, value); }

You could go for something as simple as:

struct A {
  uint bitData;
  FIELD(bitData, one, 0, 1)
  FIELD(bitData, two, 1, 2)
};

And have the bit fields implemented as properties you can easily access:

A a;
a.set_two(3);
cout << a.two();

Replace decltype with gcc's typeof pre-C++11.

How do you convert an entire directory with ffmpeg?

@Linux To convert a bunch, my one liner is this, as example (.avi to .mkv) in same directory:

for f in *.avi; do ffmpeg -i "${f}" "${f%%.*}.mkv"; done

please observe the double "%%" in the output statement. It gives you not only the first word or the input filename, but everything before the last dot.

How to write a switch statement in Ruby

Many programming languages, especially those derived from C, have support for the so-called Switch Fallthrough. I was searching for the best way to do the same in Ruby and thought it might be useful to others:

In C-like languages fallthrough typically looks like this:

switch (expression) {
    case 'a':
    case 'b':
    case 'c':
        // Do something for a, b or c
        break;
    case 'd':
    case 'e':
        // Do something else for d or e
        break;
}

In Ruby, the same can be achieved in the following way:

case expression
when 'a', 'b', 'c'
  # Do something for a, b or c
when 'd', 'e'
  # Do something else for d or e
end

This is not strictly equivalent, because it's not possible to let 'a' execute a block of code before falling through to 'b' or 'c', but for the most part I find it similar enough to be useful in the same way.

JavaScript equivalent to printf/String.Format

I started porting the Java String.format (actually new Formatter().format()) to javascript. The initial version is available at:

https://github.com/RobAu/javascript.string.format

You can simple add the javscript and call StringFormat.format("%.2f", [2.4]); etc.

Please note it is NOT finished yet, but feedback is welcome :)

How to check if MySQL returns null/empty?

select FOUND_ROWS();

will return no. of records selected by select query.

Resizing Images in VB.NET

Here is an article with full details on how to do this.

Private Sub btnScale_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles btnScale.Click
    ' Get the scale factor.
    Dim scale_factor As Single = Single.Parse(txtScale.Text)

    ' Get the source bitmap.
    Dim bm_source As New Bitmap(picSource.Image)

    ' Make a bitmap for the result.
    Dim bm_dest As New Bitmap( _
        CInt(bm_source.Width * scale_factor), _
        CInt(bm_source.Height * scale_factor))

    ' Make a Graphics object for the result Bitmap.
    Dim gr_dest As Graphics = Graphics.FromImage(bm_dest)

    ' Copy the source image into the destination bitmap.
    gr_dest.DrawImage(bm_source, 0, 0, _
        bm_dest.Width + 1, _
        bm_dest.Height + 1)

    ' Display the result.
    picDest.Image = bm_dest
End Sub

[Edit]
One more on the similar lines.

Simple way to query connected USB devices info in Python?

If you are working on windows, you can use pywin32 (old link: see update below).

I found an example here:

import win32com.client

wmi = win32com.client.GetObject ("winmgmts:")
for usb in wmi.InstancesOf ("Win32_USBHub"):
    print usb.DeviceID

Update Apr 2020:

'pywin32' release versions from 218 and up can be found here at github. Current version 227.