Programs & Examples On #Gud

Content Security Policy "data" not working for base64 Images in Chrome 28

According to the grammar in the CSP spec, you need to specify schemes as scheme:, not just scheme. So, you need to change the image source directive to:

img-src 'self' data:;

Error LNK2019: Unresolved External Symbol in Visual Studio

I was getting this error after adding the include files and linking the library. It was because the lib was built with non-unicode and my application was unicode. Matching them fixed it.

How to suppress scientific notation when printing float values?

Most of the answers above require you to specify precision. But what if you want to display floats like this, with no unnecessary zeros:

1
0.1
0.01
0.001
0.0001
0.00001
0.000001
0.000000000001

numpy has an answer: np.format_float_positional

import numpy as np

def format_float(num):
    return np.format_float_positional(num, trim='-')

Showing an image from console in Python

If you would like to show it in a new window, you could use Tkinter + PIL library, like so:

import tkinter as tk
from PIL import ImageTk, Image

def show_imge(path):
    image_window = tk.Tk()
    img = ImageTk.PhotoImage(Image.open(path))
    panel = tk.Label(image_window, image=img)
    panel.pack(side="bottom", fill="both", expand="yes")
    image_window.mainloop()

This is a modified example that can be found all over the web.

Removing duplicate elements from an array in Swift

In case you need values sorted, this works (Swift 4)

let sortedValues = Array(Set(array)).sorted()

Removing empty rows of a data file in R

This is similar to some of the above answers, but with this, you can specify if you want to remove rows with a percentage of missing values greater-than or equal-to a given percent (with the argument pct)

drop_rows_all_na <- function(x, pct=1) x[!rowSums(is.na(x)) >= ncol(x)*pct,]

Where x is a dataframe and pct is the threshold of NA-filled data you want to get rid of.

pct = 1 means remove rows that have 100% of its values NA. pct = .5 means remome rows that have at least half its values NA

HTML page disable copy/paste

You can use jquery for this:

$('body').bind('copy paste',function(e) {
    e.preventDefault(); return false; 
});

Using jQuery bind() and specififying your desired eventTypes .

HashMap: One Key, multiple Values

Thinking about a Map with 2 keys immediately compelled me to use a user-defined key, and that would probably be a Class. Following is the key Class:

public class MapKey {
    private Object key1;
    private Object key2;

    public Object getKey1() {
        return key1;
    }

    public void setKey1(Object key1) {
        this.key1 = key1;
    }

    public Object getKey2() {
        return key2;
    }

    public void setKey2(Object key2) {
        this.key2 = key2;
    }
}


// Create first map entry with key <A,B>.
        MapKey mapKey1 = new MapKey();
        mapKey1.setKey1("A");
        mapKey1.setKey2("B");

Purpose of "%matplotlib inline"

To explain it clear:

If you don't like it like this:

enter image description here

add %matplotlib inline

enter image description here

and there you have it in your jupyter notebook.

How to embed a PDF viewer in a page?

using bootstrap you can have a responsive and mobile first embeded file.

<div class="embed-responsive embed-responsive-16by9">
  <iframe class="embed-responsive-item" src="address of your file" allowfullscreen></iframe>
</div>

Aspect ratios can be customized with modifier classes.
<!-- 21:9 aspect ratio -->
<div class="embed-responsive embed-responsive-21by9">
  <iframe class="embed-responsive-item" src="..."></iframe>
</div>

<!-- 16:9 aspect ratio -->
<div class="embed-responsive embed-responsive-16by9">
  <iframe class="embed-responsive-item" src="..."></iframe>
</div>

<!-- 4:3 aspect ratio -->
<div class="embed-responsive embed-responsive-4by3">
  <iframe class="embed-responsive-item" src="..."></iframe>
</div>

<!-- 1:1 aspect ratio -->
<div class="embed-responsive embed-responsive-1by1">
  <iframe class="embed-responsive-item" src="..."></iframe>
</div>

DataRow: Select cell value by a given column name

You can get the column value in VB.net

Dim row As DataRow = fooTable.Rows(0)
Dim temp = Convert.ToString(row("ColumnName"))

And in C# you can use Jimmy's Answer, just be careful while converting it to ToString(). It can throw null exception if the data is null instead Use Convert.ToString(your_expression) to avoid null exception reference

Get name of object or class

Get your object's constructor function and then inspect its name property.

myObj.constructor.name

Returns "myClass".

CSS two div width 50% in one line with line break in file

The problem you run into when setting width to 50% is the rounding of subpixels. If the width of your container is i.e. 99 pixels, a width of 50% can result in 2 containers of 50 pixels each.

Using float is probably easiest, and not such a bad idea. See this question for more details on how to fix the problem then.

If you don't want to use float, try using a width of 49%. This will work cross-browser as far as I know, but is not pixel-perfect..

html:

<div id="a">A</div>
<div id="b">B</div>

css:

#a, #b {
    width: 49%;
    display: inline-block; 
}
#a {background-color: red;}
#b {background-color: blue;}

how to insert datetime into the SQL Database table?

You will need to have a datetime column in a table. Then you can do an insert like the following to insert the current date:

INSERT INTO MyTable (MyDate) Values (GetDate())

If it is not today's date then you should be able to use a string and specify the date format:

INSERT INTO MyTable (MyDate) Values (Convert(DateTime,'19820626',112)) --6/26/1982

You do not always need to convert the string either, often you can just do something like:

INSERT INTO MyTable (MyDate) Values ('06/26/1982') 

And SQL Server will figure it out for you.

android: changing option menu items programmatically

menu.xml

  <item 
    android:id="@+id/item1"
    android:title="your Item">
  </item>

put in your java file

  public void onPrepareOptionsMenu(Menu menu) {

    menu.removeItem(R.id.item1);
}

how to toggle attr() in jquery

If you're feeling fancy:

$('.list-sort').attr('colspan', function(index, attr){
    return attr == 6 ? null : 6;
});

Working Fiddle

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.

How to preserve request url with nginx proxy_pass

for my auth server... this works. i like to have options for /auth for my own humanized readability... or also i have it configured by port/upstream for machine to machine.

.

at the beginning of conf

####################################################
upstream auth {
    server 127.0.0.1:9011 weight=1 fail_timeout=300s;
    keepalive 16;
  }

Inside my 443 server block

          if (-d $request_filename) {
          rewrite [^/]$ $scheme://$http_host$uri/ permanent;
      }

  location /auth {
          proxy_pass http://$http_host:9011;
          proxy_set_header Origin           http://$host;
          proxy_set_header Host             $http_host:9011;
          proxy_set_header X-Forwarded-For  $proxy_add_x_forwarded_for;
          proxy_set_header Upgrade          $http_upgrade;
          proxy_set_header Connection       $http_connection;
          proxy_http_version 1.1;
      }

At the bottom of conf

#####################################################################
#                                                                   #
#     Proxies for all the Other servers on other ports upstream     #
#                                                                   #
#####################################################################


#######################
#        Fusion       #
#######################

server {
    listen 9001 ssl;

#############  Lock it down  ################

# SSL certificate locations
    ssl_certificate /etc/letsencrypt/live/allineed.app/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/allineed.app/privkey.pem;

# Exclusions

    include snippets/exclusions.conf;

# Security

    include snippets/security.conf;
    include snippets/ssl.conf;

# Fastcgi cache rules

    include snippets/fastcgi-cache.conf;
    include snippets/limits.conf;
    include snippets/nginx-cloudflare.conf;

###########  Location upstream ##############

    location  ~ / {
        proxy_pass http://auth;
        proxy_set_header Origin           http://$host;
        proxy_set_header Host             $host:$server_port;
        proxy_set_header X-Forwarded-For  $proxy_add_x_forwarded_for;
        proxy_set_header Upgrade          $http_upgrade;
        proxy_set_header Connection       $http_connection;
        proxy_http_version 1.1;
    }
        if (-d $request_filename) {
        rewrite [^/]$ $scheme://$http_host$uri/ permanent;
    }
}

How to add title to seaborn boxplot

.set_title('') can be used to add title to Seaborn Plot

import seaborn as sb
sb.boxplot().set_title('Title')

Is it possible to make desktop GUI application in .NET Core?

.NET Core 3 will have support for creating Windows desktop applications. I watched a demo of the technology yesterday during the .NET Conference.

This is the only blog post I could find, but it does illustrate the point: .NET Core 3 and Support for Windows Desktop Applications

How can I disable a button in a jQuery dialog from a function?

I think it should work with all,

<script type="text/javascript">
    $(document).ready(function() {
        $('#dialog').dialog('open');
        $(function(){
            $('#dialog').dialog({
                autoOpen: true,
                width: 400,
                modal: true,
                overlay: {
                    opacity: 0.8,
                    background: "black"
                },
                resizable: false,
                show: 'slow',
                buttons: {
                    //"OK":function() {
                    //    window.location="index.php?view=list";
                    //},
                    "Cancel": function() {
                        $(this).dialog("close");
                        $(this).attr("class", "button");
                    }
                }
            });

            var dlgFirstButton = $('.ui-dialog-buttonpane').find('button:first');
            dlgFirstButton.addClass('button');
        });
    });
</script>

How do I make entire div a link?

the html:

 <a class="xyz">your content</a>

the css:

.xyz{
  display: block;
}

This will make the anchor be a block level element like a div.

Get Absolute URL from Relative path (refactored method)

The final version taking care of all previous complaints (ports, logical url, relative url, existing absolute url...etc.) considering the current handler is the page:

public static string ConvertToAbsoluteUrl(string url)
{
    if (!IsAbsoluteUrl(url))
    {
        if (HttpContext.Current != null && HttpContext.Current.Request != null && HttpContext.Current.Handler is System.Web.UI.Page)
        {
            var originalUrl = HttpContext.Current.Request.Url;
            return string.Format("{0}://{1}{2}{3}", originalUrl.Scheme, originalUrl.Host, !originalUrl.IsDefaultPort ? (":" + originalUrl.Port) : string.Empty, ((System.Web.UI.Page)HttpContext.Current.Handler).ResolveUrl(url));
        }
        throw new Exception("Invalid context!");
    }
    else
        return url;
}

private static bool IsAbsoluteUrl(string url)
{
    Uri result;
    return Uri.TryCreate(url, UriKind.Absolute, out result);
}

How do I autoindent in Netbeans?

If you want auto-indent just like Emacs does it on TAB, i.e. indent the current line and move the cursor to the first non-whitespace character, do this:

  1. Go to Tools -> Options -> Editor -> Macros
  2. Create a new macro and call it something like "tabindent"
  3. Insert the following macro code:

    reindent-line caret-line-first-column caret-begin-line

  4. Click "Set Shortcut" and press TAB

Error 1022 - Can't write; duplicate key in table

I just spent the last 4 hours with the same issue. What I did was to simply make sure the constraints had unique names.

You can rename the constraints. I appended a number to mine so I could easily trace the number of occurrences.

Example

If a constraint in a table is named boy with a foreign key X The next constraint with the foreign key X can be called boy1

I'm sure you'd figure out better names than I did.

Are 2 dimensional Lists possible in c#?

As Jon Skeet mentioned you can do it with a List<Track> instead. The Track class would look something like this:

public class Track {
    public int TrackID { get; set; }
    public string Name { get; set; }
    public string Artist { get; set; }
    public string Album { get; set; }
    public int PlayCount { get; set; }
    public int SkipCount { get; set; }
}

And to create a track list as a List<Track> you simply do this:

var trackList = new List<Track>();

Adding tracks can be as simple as this:

trackList.add( new Track {
    TrackID = 1234,
    Name = "I'm Gonna Be (500 Miles)",
    Artist = "The Proclaimers",
    Album = "Finest",
    PlayCount = 10,
    SkipCount = 1
});

Accessing tracks can be done with the indexing operator:

Track firstTrack = trackList[0];

Hope this helps.

Overflow:hidden dots at the end

Yes, via the text-overflow property in CSS 3. Caveat: it is not universally supported yet in browsers.

Genymotion Android emulator - adb access?

My working solution is:

cd /opt/genymobile/genymotion/tools
./adb shell

You have to use its own adb tool.

Android Volley - BasicNetwork.performRequest: Unexpected response code 400

You mean that want to get status codes?

VolleyError has a member variable type of NetworkResponse and it is public.

You can access error.networkResponse.statusCode for http error code.

I hope it is helpful for you.

Failed to load resource: the server responded with a status of 500 (Internal Server Error) in Bind function

The 500 code would normally indicate an error on the server, not anything with your code. Some thoughts

  • Talk to the server developer for more info. You can't get more info directly.
  • Verify your arguments into the call (values). Look for anything you might think could cause a problem for the server process. The process should not die and should return you a better code, but bugs happen there also.
  • Could be intermittent, like if the server database goes down. May be worth trying at another time.

How to extract hours and minutes from a datetime.datetime object?

Don't know how you want to format it, but you can do:

print("Created at %s:%s" % (t1.hour, t1.minute))

for example.

How to replace a character by a newline in Vim

Use \r instead of \n.

Substituting by \n inserts a null character into the text. To get a newline, use \r. When searching for a newline, you’d still use \n, however. This asymmetry is due to the fact that \n and \r do slightly different things:

\n matches an end of line (newline), whereas \r matches a carriage return. On the other hand, in substitutions \n inserts a null character whereas \r inserts a newline (more precisely, it’s treated as the input CR). Here’s a small, non-interactive example to illustrate this, using the Vim command line feature (in other words, you can copy and paste the following into a terminal to run it). xxd shows a hexdump of the resulting file.

echo bar > test
(echo 'Before:'; xxd test) > output.txt
vim test '+s/b/\n/' '+s/a/\r/' +wq
(echo 'After:'; xxd test) >> output.txt
more output.txt
Before:
0000000: 6261 720a                                bar.
After:
0000000: 000a 720a                                ..r.

In other words, \n has inserted the byte 0x00 into the text; \r has inserted the byte 0x0a.

How to select only 1 row from oracle sql?

If you want to get back only the first row of a sorted result with the least subqueries, try this:

select *
  from ( select a.*
              , row_number() over ( order by sysdate_col desc ) as row_num
           from table_name a )
  where row_num = 1;

How to send image to PHP file using Ajax?

Post both multiple text inputs plus multiple files via Ajax in one Ajax request

HTML

<form class="form-horizontal" id="myform" enctype="multipart/form-data">
<input type="text" name="name" class="form-control">
<input type="text" name="email" class="form-control">
<input type="file" name="image" class="form-control">
<input type="file" name="anotherFile" class="form-control">

Jquery Code

$(document).on('click','#btnSendData',function (event) {
    event.preventDefault();
    var form = $('#myform')[0];
    var formData = new FormData(form);
    // Set header if need any otherwise remove setup part
    $.ajaxSetup({
        headers: {
            'X-CSRF-TOKEN': $('meta[name="token"]').attr('value')
        }
    });
    $.ajax({
        url: "{{route('sendFormWithImage')}}",// your request url
        data: formData,
        processData: false,
        contentType: false,
        type: 'POST',
        success: function (data) {
            console.log(data);
        },
        error: function () {

        }
    });

});

Django model "doesn't declare an explicit app_label"

in my case I was able to find a fix and by looking at the everyone else's code it may be the same issue.. I simply just had to add 'django.contrib.sites' to the list of installed apps in the settings.py file.

hope this helps someone. this is my first contribution to the coding community

PHP: convert spaces in string into %20?

Use the rawurlencode function instead.

Java Minimum and Maximum values in Array

//To Find Max and Min value in an array without sorting in java

import java.util.Scanner;
import java.util.*;
public class MaxMin_WoutSort {
 public static void main(String args[])
   {
      int n,max=Integer.MIN_VALUE,min=Integer.MAX_VALUE;
      System.out.println("Enter the number of elements: ");
      Scanner sc = new Scanner(System.in);

      int[] arr = new int[sc.nextInt()]; //U can't say static or dynamic.
                                         //UnWrapping object sc to int value;sc.nextInt()
      System.out.println("Enter the elements: ");
      for(int i=0;i<arr.length;i++)      //Loop for entering values in array
      {
          int next = sc.nextInt();
          arr[i] = next;
      }
      for(int j=0;j<arr.length;j++)
     {
          if(arr[j]>max)               //Maximum Condition
            max = arr[j];
          else if(arr[j]<min)         //Minimum Condition
              min = arr[j];
     }
     System.out.println("Highest Value in array: " +max);
     System.out.println("Smallest Value in array: "+min);

 }
}

How to export data with Oracle SQL Developer?

In SQL Developer, from the top menu choose Tools > Data Export. This launches the Data Export wizard. It's pretty straightforward from there.

There is a tutorial on the OTN site. Find it here.

How to add key,value pair to dictionary?

Add a key, value pair to dictionary

aDict = {}
aDict[key] = value

What do you mean by dynamic addition.

How can I put a database under git (version control)?

I think X-Istence is on the right track, but there are a few more improvements you can make to this strategy. First, use:

$pg_dump --schema ... 

to dump the tables, sequences, etc and place this file under version control. You'll use this to separate the compatibility changes between your branches.

Next, perform a data dump for the set of tables that contain configuration required for your application to operate (should probably skip user data, etc), like form defaults and other data non-user modifiable data. You can do this selectively by using:

$pg_dump --table=.. <or> --exclude-table=..

This is a good idea because the repo can get really clunky when your database gets to 100Mb+ when doing a full data dump. A better idea is to back up a more minimal set of data that you require to test your app. If your default data is very large though, this may still cause problems though.

If you absolutely need to place full backups in the repo, consider doing it in a branch outside of your source tree. An external backup system with some reference to the matching svn rev is likely best for this though.

Also, I suggest using text format dumps over binary for revision purposes (for the schema at least) since these are easier to diff. You can always compress these to save space prior to checking in.

Finally, have a look at the postgres backup documentation if you haven't already. The way you're commenting on backing up 'the database' rather than a dump makes me wonder if you're thinking of file system based backups (see section 23.2 for caveats).

OpenCV TypeError: Expected cv::UMat for argument 'src' - What is this?

I got round thid by writing/reading to a file. I guessed cv.imread would put it into the format it needed. This code for anki Vector SDK program but you get the idea.

tmpImage = robot.camera.latest_image.raw_image.save('temp.png')
pilImage = cv.imread('temp.png')

How do I set headers using python's urllib?

adding HTTP headers using urllib2:

from the docs:

import urllib2
req = urllib2.Request('http://www.example.com/')
req.add_header('Referer', 'http://www.python.org/')
resp = urllib2.urlopen(req)
content = resp.read()

How to combine two lists in R

We can use append

append(l1, l2)

It also has arguments to insert element at a particular location.

JSF rendered multiple combined conditions

Assuming that "a" and "b" are bean properties

rendered="#{bean.a==12 and (bean.b==13 or bean.b==15)}"

You may look at JSF EL operators

Failed to authenticate on SMTP server error using gmail

If you still get this error when sending email: "Failed to authenticate on SMTP server with username "[email protected]" using 3 possible authenticators"

You may try one of these methods:

  1. Go to https://accounts.google.com/UnlockCaptcha, click continue and unlock your account for access through other media/sites.

  2. Using a double quote password: "your password" <-- this one also solved my problem.

How do I add a placeholder on a CharField in Django?

It's undesirable to have to know how to instantiate a widget when you just want to override its placeholder.

    q = forms.CharField(label='search')
    ...
    q.widget.attrs['placeholder'] = "Search"

Convert string into integer in bash script - "Leading Zero" number error

In Short: In order to deal with "Leading Zero" numbers (any 0 digit that comes before the first non-zero) in bash - Use bc An arbitrary precision calculator language

Example:

a="000001"
b=$(echo $a | bc)
echo $b

Output: 1

From Bash manual:

"bc is a language that supports arbitrary precision numbers with interactive execution of statements. There are some similarities in the syntax to the C programming lan- guage. A standard math library is available by command line option. If requested, the math library is defined before processing any files. bc starts by processing code from all the files listed on the command line in the order listed. After all files have been processed, bc reads from the standard input. All code is executed as it is read. (If a file contains a command to halt the processor, bc will never read from the standard input.)"

Button Width Match Parent

For match_parent you can use

SizedBox(
  width: double.infinity, // match_parent
  child: RaisedButton(...)
)

For any particular value you can use

SizedBox(
  width: 100, // specific value
  child: RaisedButton(...)
)

Making a DateTime field in a database automatic?

You need to set the "default value" for the date field to getdate(). Any records inserted into the table will automatically have the insertion date as their value for this field.

The location of the "default value" property is dependent on the version of SQL Server Express you are running, but it should be visible if you select the date field of your table when editing the table.

Add directives from directive in AngularJS

Try storing the state in a attribute on the element itself, such as superDirectiveStatus="true"

For example:

angular.module('app')
  .directive('superDirective', function ($compile, $injector) {
    return {
      restrict: 'A',
      replace: true,
      link: function compile(scope, element, attrs) {
        if (element.attr('datepicker')) { // check
          return;
        }
        var status = element.attr('superDirectiveStatus');
        if( status !== "true" ){
             element.attr('datepicker', 'someValue');
             element.attr('datepicker-language', 'en');
             // some more
             element.attr('superDirectiveStatus','true');
             $compile(element)(scope);

        }

      }
    };
  });

I hope this helps you.

Best XML Parser for PHP

It depends on what you are trying to do with the XML files. If you are just trying to read the XML file (like a configuration file), The Wicked Flea is correct in suggesting SimpleXML since it creates what amounts to nested ArrayObjects. e.g. value will be accessible by $xml->root->child.

If you are looking to manipulate the XML files you're probably best off using DOM XML

What is .htaccess file?

Htaccess is a configuration file of apache which is used to make changes in the configuration on a directory basis. Htaccess file is used to do changes in functions and features of the apache server. Htaccess is used to rewrite the URL. It is used to make site address protected. Also to restrict IP addresses so on particular IP address site will not be opened

bash echo number of lines of file given in a bash variable without the file name

I normally use the 'back tick' feature of bash

export NUM_LINES=`wc -l filename`

Note the 'tick' is the 'back tick' e.g. ` not the normal single quote

Meaning of *& and **& in C++

That's passing a pointer by reference rather than by value. This for example allows altering the pointer (not the pointed-to object) in the function is such way that the calling code sees the change.

Compare:

void nochange( int* pointer ) //passed by value
{
   pointer++; // change will be discarded once function returns
}

void change( int*& pointer ) //passed by reference
{
   pointer++; // change will persist when function returns
}

Iterate a list with indexes in Python

Here it is a solution using map function:

>>> a = [3, 7, 19]
>>> map(lambda x: (x, a[x]), range(len(a)))
[(0, 3), (1, 7), (2, 19)]

And a solution using list comprehensions:

>>> a = [3,7,19]
>>> [(x, a[x]) for x in range(len(a))]
[(0, 3), (1, 7), (2, 19)]

Core dumped, but core file is not in the current directory?

With the launch of systemd, there's another scenario aswell. By default systemd will store core dumps in its journal, being accessible with the systemd-coredumpctl command. Defined in the core_pattern-file:

$ cat /proc/sys/kernel/core_pattern 
|/usr/lib/systemd/systemd-coredump %p %u %g %s %t %e

This behaviour can be disabled with a simple "hack":

$ ln -s /dev/null /etc/sysctl.d/50-coredump.conf
$ sysctl -w kernel.core_pattern=core      # or just reboot

As always, the size of core dumps has to be equal or higher than the size of the core that is being dumped, as done by for example ulimit -c unlimited.

How do I generate random integers within a specific range in Java?

Note that this approach is more biased and less efficient than a nextInt approach, https://stackoverflow.com/a/738651/360211

One standard pattern for accomplishing this is:

Min + (int)(Math.random() * ((Max - Min) + 1))

The Java Math library function Math.random() generates a double value in the range [0,1). Notice this range does not include the 1.

In order to get a specific range of values first, you need to multiply by the magnitude of the range of values you want covered.

Math.random() * ( Max - Min )

This returns a value in the range [0,Max-Min), where 'Max-Min' is not included.

For example, if you want [5,10), you need to cover five integer values so you use

Math.random() * 5

This would return a value in the range [0,5), where 5 is not included.

Now you need to shift this range up to the range that you are targeting. You do this by adding the Min value.

Min + (Math.random() * (Max - Min))

You now will get a value in the range [Min,Max). Following our example, that means [5,10):

5 + (Math.random() * (10 - 5))

But, this still doesn't include Max and you are getting a double value. In order to get the Max value included, you need to add 1 to your range parameter (Max - Min) and then truncate the decimal part by casting to an int. This is accomplished via:

Min + (int)(Math.random() * ((Max - Min) + 1))

And there you have it. A random integer value in the range [Min,Max], or per the example [5,10]:

5 + (int)(Math.random() * ((10 - 5) + 1))

Confirm Password with jQuery Validate

I'm implementing it in Play Framework and for me it worked like this:

1) Notice that I used data-rule-equalTo in input tag for the id inputPassword1. The code section of userform in my Modal:

<div class="form-group">
    <label for="pass1">@Messages("authentication.password")</label>
    <input class="form-control required" id="inputPassword1" placeholder="@Messages("authentication.password")" type="password" name="password" maxlength=10 minlength=5>
</div>
<div class="form-group">
    <label for="pass2">@Messages("authentication.password2")</label>
    <input class="form-control required" data-rule-equalTo="#inputPassword1" id="inputPassword2" placeholder="@Messages("authentication.password")" type="password" name="password2">
</div>

2)Since I used validator within a Modal

$(document).on("click", ".createUserModal", function () {
       $(this).find('#userform').validate({
           rules: {
               firstName: "required",
               lastName: "required",
               nationalId: {
                   required: true,
                   digits:true
               },
               email: {
                   required: true,
                   email: true
               },
               optradio: "required",
               password :{
                   required: true,
                   minlength: 5
               },
               password2: {
                   required: true
               }
           },
           highlight: function (element) {
               $(element).parent().addClass('error')
           },
           unhighlight: function (element) {
               $(element).parent().removeClass('error')
           },
           onsubmit: true
       });

   });

Hope it helps someone :).

how to set cursor style to pointer for links without hrefs

Use CSS cursor: pointer if I remember correctly.

Either in your CSS file:

.link_cursor
{
    cursor: pointer;
}

Then just add the following HTML to any elements you want to have the link cursor: class="link_cursor" (the preferred method.)

Or use inline CSS:

<a style="cursor: pointer;">

What's the difference between Docker Compose vs. Dockerfile

In Microservices world (having a common shared codebase), each Microservice would have a Dockerfile whereas at the root level (generally outside of all Microservices and where your parent POM resides) you would define a docker-compose.yml to group all Microservices into a full-blown app.

In your case "Docker Compose" is preferred over "Dockerfile". Think "App" Think "Compose".

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

Even more modification based on response from @vkkeeper. Added possibility to query table from the specific schema.

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

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

        firstrec := TRUE;
        FOR constraint_rec IN
            SELECT conname, pg_get_constraintdef(c.oid) as constrainddef
                FROM pg_constraint c
                    WHERE conrelid=(
                        SELECT attrelid FROM pg_attribute
                        WHERE attrelid = (
                            SELECT oid FROM pg_class WHERE relname = table_rec.relname
                                AND relnamespace = (SELECT ns.oid FROM pg_namespace ns WHERE ns.nspname = p_schema_name)
                        ) AND attname='tableoid'
                    )
        LOOP
            v_table_ddl:=v_table_ddl||','||chr(10);
            v_table_ddl:=v_table_ddl||'CONSTRAINT '||constraint_rec.conname;
            v_table_ddl:=v_table_ddl||chr(10)||'    '||constraint_rec.constrainddef;
            firstrec := FALSE;
        END LOOP;
        v_table_ddl:=v_table_ddl||');';
        RETURN NEXT v_table_ddl;
    END LOOP;
END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;

Counter increment in Bash loop not working

There were two conditions that caused the expression ((var++)) to fail for me:

  1. If I set bash to strict mode (set -euo pipefail) and if I start my increment at zero (0).

  2. Starting at one (1) is fine but zero causes the increment to return "1" when evaluating "++" which is a non-zero return code failure in strict mode.

I can either use ((var+=1)) or var=$((var+1)) to escape this behavior

Convert timestamp to date in MySQL query

Try:

SELECT strftime("%Y-%d-%m", col_name, 'unixepoch') AS col_name

It will format timestamp in milliseconds to yyyy-mm-dd string.

Android - Best and safe way to stop thread

You should make your thread support interrupts. Basically, you can call yourThread.interrupt() to stop the thread and, in your run() method you'd need to periodically check the status of Thread.interrupted()

There is a good tutorial here.

How to Get the Query Executed in Laravel 5? DB::getQueryLog() Returning Empty Array

Add this function to your helper file and simply call.

function getRawQuery($sql){
        $query = str_replace(array('?'), array('\'%s\''), $sql->toSql());
        $query = vsprintf($query, $sql->getBindings());     
        return $query;
}

Output: "select * from user where status = '1' order by id desc limit 25 offset 0"

What special characters must be escaped in regular expressions?

To know when and what to escape without attempts is necessary to understand precisely the chain of contexts the string pass through. You will specify the string from the farthest side to its final destination which is the memory handled by the regexp parsing code.

Be aware how the string in memory is processed: if can be a plain string inside the code, or a string entered to the command line, but a could be either an interactive command line or a command line stated inside a shell script file, or inside a variable in memory mentioned by the code, or an (string)argument through further evaluation, or a string containing code generated dynamically with any sort of encapsulation...

Each of this context assigned some characters with special functionality.

When you want to pass the character literally without using its special function (local to the context), than that's the case you have to escape it, for the next context... which might need some other escape characters which might additionally need to be escaped in the preceding context(s). Furthermore there can be things like character encoding (the most insidious is utf-8 because it look like ASCII for common characters, but might be optionally interpreted even by the terminal depending on its settings so it might behave differently, then the encoding attribute of HTML/XML, it's necessary to understand the process precisely right.

E.g. A regexp in the command line starting with perl -npe, needs to be transferred to a set of exec system calls connecting as pipe the file handles, each of this exec system calls just has a list of arguments that were separated by (non escaped)spaces, and possibly pipes(|) and redirection (> N> N>&M), parenthesis, interactive expansion of * and ?, $(()) ... (all this are special characters used by the *sh which might appear to interfere with the character of the regular expression in the next context, but they are evaluated in order: before the command line. The command line is read by a program as bash/sh/csh/tcsh/zsh, essentially inside double quote or single quote the escape is simpler but it is not necessary to quote a string in the command line because mostly the space has to be prefixed with backslash and the quote are not necessary leaving available the expand functionality for characters * and ?, but this parse as different context as within quote. Then when the command line is evaluated the regexp obtained in memory (not as written in the command line) receives the same treatment as it would be in a source file. For regexp there is character-set context within square brackets [ ], perl regular expression can be quoted by a large set of non alfa-numeric characters (E.g. m// or m:/better/for/path: ...).

You have more details about characters in other answer, which are very specific to the final regexp context. As I noted you mention that you find the regexp escape with attempts, that's probably because different context has different set of character that confused your memory of attempts (often backslash is the character used in those different context to escape a literal character instead of its function).

Eclipse - Installing a new JRE (Java SE 8 1.8.0)

You can have many java versions in your system.

I think you should add the java 8 in yours JREs installed or edit.

Take a look my screen:

enter image description here

If you click in edit (check your java 8 path):

enter image description here

Integer.toString(int i) vs String.valueOf(int i)

To answer the OPs question, it's simply a helper wrapper to have the other call, and comes down to style choice and that is it. I think there's a lot of misinformation here and the best thing a Java developer can do is look at the implementation for each method, it's one or two clicks away in any IDE. You will clearly see that String.valueOf(int) is simply calling Integer.toString(int) for you.

Therefore, there is absolutely zero difference, in that they both create a char buffer, walk through the digits in the number, then copy that into a new String and return it (therefore each are creating one String object). Only difference is one extra call, which the compiler eliminates to a single call anyway.

So it matters not which you call, other than maybe code-consistency. As to the comments about nulls, it takes a primitive, therefore it can not be null! You will get a compile-time error if you don't initialize the int being passed. So there is no difference in how it handles nulls as they're non-existent in this case.

Visual Studio 2017: Display method references

For anyone who looks at this today after 2 years, Visual Studio 2019 (Community edition as well) shows the references

Merging Cells in Excel using C#

Worksheet["YourRange"].Merge();

Grant Select on all Tables Owned By Specific User

yes, its possible, run this command:

lets say you have user called thoko

grant select any table, insert any table, delete any table, update any table to thoko;

note: worked on oracle database

How to achieve ripple animation using support library?

sometimes will b usable this line on any layout or components.

 android:background="?attr/selectableItemBackground"

Like as.

 <RelativeLayout
                android:id="@+id/relative_ticket_checkin"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:background="?attr/selectableItemBackground">

How to break out or exit a method in Java?

Use the return keyword to exit from a method.

public void someMethod() {
    //... a bunch of code ...
    if (someCondition()) {
        return;
    }
    //... otherwise do the following...
}

Pls note: We may use break statements which are used to break/exit only from a loop, and not the entire program.

To exit from program: System.exit() Method:
System.exit has status code, which tells about the termination, such as:
exit(0) : Indicates successful termination.
exit(1) or exit(-1) or any non-zero value – indicates unsuccessful termination.

CURL alternative in Python

Here's a simple example using urllib2 that does a basic authentication against GitHub's API.

import urllib2

u='username'
p='userpass'
url='https://api.github.com/users/username'

# simple wrapper function to encode the username & pass
def encodeUserData(user, password):
    return "Basic " + (user + ":" + password).encode("base64").rstrip()

# create the request object and set some headers
req = urllib2.Request(url)
req.add_header('Accept', 'application/json')
req.add_header("Content-type", "application/x-www-form-urlencoded")
req.add_header('Authorization', encodeUserData(u, p))
# make the request and print the results
res = urllib2.urlopen(req)
print res.read()

Furthermore if you wrap this in a script and run it from a terminal you can pipe the response string to 'mjson.tool' to enable pretty printing.

>> basicAuth.py | python -mjson.tool

One last thing to note, urllib2 only supports GET & POST requests.
If you need to use other HTTP verbs like DELETE, PUT, etc you'll probably want to take a look at PYCURL

Unable to install Android Studio in Ubuntu

@warsong is right. Installing only lib32stdc++6 solved the problem.

For next uses I rewrite @warsongs comment in answer area.

sudo apt-get install lib32stdc++6

Update :

For Ubuntu 15.04,15.10,16.04 LTS & Debian 8

ggplot2 line chart gives "geom_path: Each group consist of only one observation. Do you need to adjust the group aesthetic?"

I found this can also occur if the most of the data plotted is outside of the axis limits. In that case, adjust the axis scales accordingly.

How can I subset rows in a data frame in R based on a vector of values?

If you really just want to subset each data frame by an index that exists in both data frames, you can do this with the 'match' function, like so:

data_A[match(data_B$index, data_A$index, nomatch=0),]
data_B[match(data_A$index, data_B$index, nomatch=0),]

This is, though, the same as:

data_A[data_A$index %in% data_B$index,]
data_B[data_B$index %in% data_A$index,]

Here is a demo:

# Set seed for reproducibility.
set.seed(1)

# Create two sample data sets.
data_A <- data.frame(index=sample(1:200, 90, rep=FALSE), value=runif(90))
data_B <- data.frame(index=sample(1:200, 120, rep=FALSE), value=runif(120))

# Subset data of each data frame by the index in the other.
t_A <- data_A[match(data_B$index, data_A$index, nomatch=0),]
t_B <- data_B[match(data_A$index, data_B$index, nomatch=0),]

# Make sure they match.
data.frame(t_A[order(t_A$index),], t_B[order(t_B$index),])[1:20,]

#    index     value index.1    value.1
# 27     3 0.7155661       3 0.65887761
# 10    12 0.6049333      12 0.14362694
# 88    14 0.7410786      14 0.42021589
# 56    15 0.4525708      15 0.78101754
# 38    18 0.2075451      18 0.70277874
# 24    23 0.4314737      23 0.78218212
# 34    32 0.1734423      32 0.85508236
# 22    38 0.7317925      38 0.56426384
# 84    39 0.3913593      39 0.09485786
# 5     40 0.7789147      40 0.31248966
# 74    43 0.7799849      43 0.10910096
# 71    45 0.2847905      45 0.26787813
# 57    46 0.1751268      46 0.17719454
# 25    48 0.1482116      48 0.99607737
# 81    53 0.6304141      53 0.26721208
# 60    58 0.8645449      58 0.96920881
# 30    59 0.6401010      59 0.67371223
# 75    61 0.8806190      61 0.69882454
# 63    64 0.3287773      64 0.36918946
# 19    70 0.9240745      70 0.11350771

Convert a python dict to a string and back

Convert dictionary into JSON (string)

import json 

mydict = { "name" : "Don", 
          "surname" : "Mandol", 
          "age" : 43} 

result = json.dumps(mydict)

print(result[0:20])

will get you:

{"name": "Don", "sur

Convert string into dictionary

back_to_mydict = json.loads(result) 

Error "can't use subversion command line client : svn" when opening android project checked out from svn

i was also getting the same Error, if you are using TortoiseSVN-1.9.5 just do two step Process 1:Click on TSVN.exe tool and 2:Select there on Second Window the Command line for Save on Local Drive with giving the path 3:Click ok Now Restart You Android Studio/IntelliJ

How do I toggle an element's class in pure JavaScript?

This one works in earlier versions of IE also.

_x000D_
_x000D_
function toogleClass(ele, class1) {_x000D_
  var classes = ele.className;_x000D_
  var regex = new RegExp('\\b' + class1 + '\\b');_x000D_
  var hasOne = classes.match(regex);_x000D_
  class1 = class1.replace(/\s+/g, '');_x000D_
  if (hasOne)_x000D_
    ele.className = classes.replace(regex, '');_x000D_
  else_x000D_
    ele.className = classes + class1;_x000D_
}
_x000D_
.red {_x000D_
  background-color: red_x000D_
}_x000D_
div {_x000D_
  width: 100px;_x000D_
  height: 100px;_x000D_
  margin-bottom: 10px;_x000D_
  border: 1px solid black;_x000D_
}
_x000D_
<div class="does red redAnother " onclick="toogleClass(this, 'red')"></div>_x000D_
_x000D_
<div class="does collapse navbar-collapse " onclick="toogleClass(this, 'red')"></div>
_x000D_
_x000D_
_x000D_

Use of "this" keyword in formal parameters for static methods in C#

This is an extension method. See here for an explanation.

Extension methods allow developers to add new methods to the public contract of an existing CLR type, without having to sub-class it or recompile the original type. Extension Methods help blend the flexibility of "duck typing" support popular within dynamic languages today with the performance and compile-time validation of strongly-typed languages.

Extension Methods enable a variety of useful scenarios, and help make possible the really powerful LINQ query framework... .

it means that you can call

MyClass myClass = new MyClass();
int i = myClass.Foo();

rather than

MyClass myClass = new MyClass();
int i = Foo(myClass);

This allows the construction of fluent interfaces as stated below.

AddTransient, AddScoped and AddSingleton Services Differences

TL;DR

Transient objects are always different; a new instance is provided to every controller and every service.

Scoped objects are the same within a request, but different across different requests.

Singleton objects are the same for every object and every request.

For more clarification, this example from .NET documentation shows the difference:

To demonstrate the difference between these lifetime and registration options, consider a simple interface that represents one or more tasks as an operation with a unique identifier, OperationId. Depending on how we configure the lifetime for this service, the container will provide either the same or different instances of the service to the requesting class. To make it clear which lifetime is being requested, we will create one type per lifetime option:

using System;

namespace DependencyInjectionSample.Interfaces
{
    public interface IOperation
    {
        Guid OperationId { get; }
    }

    public interface IOperationTransient : IOperation
    {
    }

    public interface IOperationScoped : IOperation
    {
    }

    public interface IOperationSingleton : IOperation
    {
    }

    public interface IOperationSingletonInstance : IOperation
    {
    }
}

We implement these interfaces using a single class, Operation, that accepts a GUID in its constructor, or uses a new GUID if none is provided:

using System;
using DependencyInjectionSample.Interfaces;
namespace DependencyInjectionSample.Classes
{
    public class Operation : IOperationTransient, IOperationScoped, IOperationSingleton, IOperationSingletonInstance
    {
        Guid _guid;
        public Operation() : this(Guid.NewGuid())
        {

        }

        public Operation(Guid guid)
        {
            _guid = guid;
        }

        public Guid OperationId => _guid;
    }
}

Next, in ConfigureServices, each type is added to the container according to its named lifetime:

services.AddTransient<IOperationTransient, Operation>();
services.AddScoped<IOperationScoped, Operation>();
services.AddSingleton<IOperationSingleton, Operation>();
services.AddSingleton<IOperationSingletonInstance>(new Operation(Guid.Empty));
services.AddTransient<OperationService, OperationService>();

Note that the IOperationSingletonInstance service is using a specific instance with a known ID of Guid.Empty, so it will be clear when this type is in use. We have also registered an OperationService that depends on each of the other Operation types, so that it will be clear within a request whether this service is getting the same instance as the controller, or a new one, for each operation type. All this service does is expose its dependencies as properties, so they can be displayed in the view.

using DependencyInjectionSample.Interfaces;

namespace DependencyInjectionSample.Services
{
    public class OperationService
    {
        public IOperationTransient TransientOperation { get; }
        public IOperationScoped ScopedOperation { get; }
        public IOperationSingleton SingletonOperation { get; }
        public IOperationSingletonInstance SingletonInstanceOperation { get; }

        public OperationService(IOperationTransient transientOperation,
            IOperationScoped scopedOperation,
            IOperationSingleton singletonOperation,
            IOperationSingletonInstance instanceOperation)
        {
            TransientOperation = transientOperation;
            ScopedOperation = scopedOperation;
            SingletonOperation = singletonOperation;
            SingletonInstanceOperation = instanceOperation;
        }
    }
}

To demonstrate the object lifetimes within and between separate individual requests to the application, the sample includes an OperationsController that requests each kind of IOperation type as well as an OperationService. The Index action then displays all of the controller’s and service’s OperationId values.

using DependencyInjectionSample.Interfaces;
using DependencyInjectionSample.Services;
using Microsoft.AspNetCore.Mvc;

namespace DependencyInjectionSample.Controllers
{
    public class OperationsController : Controller
    {
        private readonly OperationService _operationService;
        private readonly IOperationTransient _transientOperation;
        private readonly IOperationScoped _scopedOperation;
        private readonly IOperationSingleton _singletonOperation;
        private readonly IOperationSingletonInstance _singletonInstanceOperation;

        public OperationsController(OperationService operationService,
            IOperationTransient transientOperation,
            IOperationScoped scopedOperation,
            IOperationSingleton singletonOperation,
            IOperationSingletonInstance singletonInstanceOperation)
        {
            _operationService = operationService;
            _transientOperation = transientOperation;
            _scopedOperation = scopedOperation;
            _singletonOperation = singletonOperation;
            _singletonInstanceOperation = singletonInstanceOperation;
        }

        public IActionResult Index()
        {
            // ViewBag contains controller-requested services
            ViewBag.Transient = _transientOperation;
            ViewBag.Scoped = _scopedOperation;
            ViewBag.Singleton = _singletonOperation;
            ViewBag.SingletonInstance = _singletonInstanceOperation;

            // Operation service has its own requested services
            ViewBag.Service = _operationService;
            return View();
        }
    }
}

Now two separate requests are made to this controller action:

First Request

Second Request

Observe which of the OperationId values varies within a request, and between requests.

  • Transient objects are always different; a new instance is provided to every controller and every service.

  • Scoped objects are the same within a request, but different across different requests

  • Singleton objects are the same for every object and every request (regardless of whether an instance is provided in ConfigureServices)

How do I edit an incorrect commit message in git ( that I've pushed )?

Suppose you have a tree like this:

dd2e86 - 946992 - 9143a9 - a6fd86 - 5a6057 [master]

First, checkout a temp branch:

git checkout -b temp

On temp branch, reset --hard to a commit that you want to change its message (for example, that commit is 946992):

git reset --hard 946992

Use amend to change the message:

git commit --amend -m "<new_message>"

After that the tree will look like this:

dd2e86 - 946992 - 9143a9 - a6fd86 - 5a6057 [master]
           \
            b886a0 [temp]

Then, cherry-pick all the commit that is ahead of 946992 from master to temp and commit them, use amend if you want to change their messages as well:

git cherry-pick 9143a9
git commit --amend -m "<new_message>
...
git cherry-pick 5a6057
git commit --amend -m "<new_message>

The tree now looks like this:

dd2e86 - 946992 - 9143a9 - a6fd86 - 5a6057 [master]
               \
                b886a0 - 41ab2c - 6c2a3s - 7c88c9 [temp]

Now force push the temp branch to remote:

git push --force origin temp:master

The final step, delete branch master on local, git fetch origin to pull branch master from the server, then switch to branch master and delete branch temp.

Now both your local and remote will have all the messages updated.

Resource blocked due to MIME type mismatch (X-Content-Type-Options: nosniff)

This might be because the browser cannot access a file. I stumbled with this type of error when creating application with node.js. You can try to directly request the script file (copying and pasting url) and see if you can retrieve it. You can see then what the real problem is. It can be because of permission of folder in which the file is located, or browser just cannot find it due to incorrect path to it. In node.js, after specifying route to file, all works.

Timeout a command in bash without unnecessary delay

timeout is probably the first approach to try. You may need notification or another command to execute if it times out. After quite a bit of searching and experimenting, I came up with this bash script:

if 
    timeout 20s COMMAND_YOU_WANT_TO_EXECUTE;
    timeout 20s AS_MANY_COMMANDS_AS_YOU_WANT;
then
    echo 'OK'; #if you want a positive response
else
    echo 'Not OK';
    AND_ALTERNATIVE_COMMANDS
fi

How to hide iOS status bar

iOS 9 onwards :

As statusBarHidden method was Deprecated from iOS9 you need to add two values in plist as below :

<key>UIStatusBarHidden</key>
<true/>
<key>UIViewControllerBasedStatusBarAppearance</key>
<false/>

or by User Interface Please refre below image :

enter image description here

As statusBarHidden is Deprecated from iOS9 :

@property(readwrite, nonatomic,getter=isStatusBarHidden) BOOL statusBarHidden NS_DEPRECATED_IOS(2_0, 9_0, "Use -[UIViewController prefersStatusBarHidden]") __TVOS_PROHIBITED;

What is this Javascript "require"?

I noticed that whilst the other answers explained what require is and that it is used to load modules in Node they did not give a full reply on how to load node modules when working in the Browser.

It is quite simple to do. Install your module using npm as you describe, and the module itself will be located in a folder usually called node_modules.

Now the simplest way to load it into your app is to reference it from your html with a script tag which points at this directory. i.e if your node_modules directory is in the root of the project at the same level as your index.html you would write this in your index.html:

<script src="node_modules/ng"></script>

That whole script will now be loaded into the page - so you can access its variables and methods directly.

There are other approaches which are more widely used in larger projects, such as a module loader like require.js. Of the two, I have not used Require myself, but I think it is considered by many people the way to go.

Maximum number of records in a MySQL database table

In InnoDB, with a limit on table size of 64 terabytes and a MySQL row-size limit of 65,535 there can be 1,073,741,824 rows. That would be minimum number of records utilizing maximum row-size limit. However, more records can be added if the row size is smaller .

Zookeeper connection error

I just have the same situation as you and I have just fixed this problem.

It is the reason that you have configured even number of zookeepers which directly result in this problem,try to change your number of zookeeper node to a odd one.

for example the original status of my zookeeper cluster is consisted of 4 nodes,then just remove one of them which result in the number of node to be 3 well ,now its ok to startup zookeeper cluster

below is the output of successfully connect to zookeeper server

2013-04-22 22:07:05,654 [myid:] - INFO  [main:ZooKeeper@438] - Initiating client connection, connectString=localhost:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@1321ed6
Welcome to ZooKeeper!
2013-04-22 22:07:05,704 [myid:] - INFO  [main-SendThread(localhost:2181):ClientCnxn$SendThread@966] - Opening socket connection to server localhost/127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown error)
JLine support is enabled
2013-04-22 22:07:05,727 [myid:] - INFO  [main-SendThread(localhost:2181):ClientCnxn$SendThread@849] - Socket connection established to localhost/127.0.0.1:2181, initiating session
[zk: localhost:2181(CONNECTING) 0] 2013-04-22 22:07:05,846 [myid:] - INFO  [main-SendThread(localhost:2181):ClientCnxn$SendThread@1207] - Session establishment complete on server localhost/127.0.0.1:2181, sessionid = 0x13e3211c06e0000, negotiated timeout = 30000

The type must be a reference type in order to use it as parameter 'T' in the generic type or method

If you put constrains on a generic class or method, every other generic class or method that is using it need to have "at least" those constrains.

Android widget: How to change the text of a button

This is very easy

Button btn = (Button) findViewById(R.id.btn);
btn.setText("MyText");

Reading data from DataGridView in C#

 private void HighLightGridRows()
 {            
     Debugger.Launch();
     for (int i = 0; i < dtgvAppSettings.Rows.Count; i++)
     {
         String key = dtgvAppSettings.Rows[i].Cells["Key"].Value.ToString();
         if (key.ToLower().Contains("applicationpath") == true)
         {
             dtgvAppSettings.Rows[i].DefaultCellStyle.BackColor = Color.Yellow;
         }
     }
 }

notifyDataSetChanged not working on RecyclerView

In my case, force run #notifyDataSetChanged in main ui thread will fix

public void refresh() {
        clearSelection();
        // notifyDataSetChanged must run in main ui thread, if run in not ui thread, it will not update until manually scroll recyclerview
        ((Activity) ctx).runOnUiThread(new Runnable() {
            @Override
            public void run() {
                adapter.notifyDataSetChanged();
            }
        });
    }

How can I limit the visible options in an HTML <select> dropdown?

I have made a simple solution for this in ReactJS you can use this in Vanilla Javascript aswell.

Javascript code

//props.options = [{value:'123',label:'123'},{value:'321',label:'321'},{value:'432',label:'432'}];
<div>
<div
  className="new-user-input"
  style={{ marginTop: '10px' }}
  onClick={() => {
    this.setState({
      showOptions: !this.state.showOptions,
    });
  }}
>
  {selectedOption ? (
    <span className="txt-black-600-12">
      {' '}
      {selectedOption.label}{' '}
    </span>
  ) : (
    <span className="txt-grey-500-12">
      Select Option
    </span>
  )}

  //Font awesome icons
  <span className="float-right">
    {this.state.showOptions ? (
      <FaAngleUp />
    ) : (
      <FaAngleDown />
    )}
  </span>
  {this.state.showOptions && (
    <div className="custom-select mt-10">
      {this.props.options.map(ele => {
        return (
          <span
            className="custom-select-option"
            onClick={() => {
              this.setState({
                selectedOption: ele,
                showOptions: false,
              });
            }}
          >
            {ele.label}
          </span>
        );
      })}
    </div>
  )}
</div>
</div>

CSS

.new-user-input {
  border: none;
  background-image: none;
  background-color: #ffffff;

  box-shadow: 0px 1px 5px 1px #d1d1d1;
  outline: none;
  display: block;
  margin: 20px auto;
  padding: 10px;
  width: 90%;
  border-radius: 8px;
}

.new-user-input:focus {
  border: none;
  background-image: none;
  background-color: #ffffff;
  outline: none;
}
    .custom-select{
  display: flex;
    flex-direction: column;
    max-height: 100px;
    overflow: auto;
    flex: 1 0;
}
.custom-select-option{
  padding: 10px 0;
  border-bottom: 1px solid #ececec;
  font-size: 10px;
  font-weight: 500;
  color: #413958;
}

Python non-greedy regexes

To start with, I do not suggest using "*" in regexes. Yes, I know, it is the most used multi-character delimiter, but it is nevertheless a bad idea. This is because, while it does match any amount of repetition for that character, "any" includes 0, which is usually something you want to throw a syntax error for, not accept. Instead, I suggest using the + sign, which matches any repetition of length > 1. What's more, from what I can see, you are dealing with fixed-length parenthesized expressions. As a result, you can probably use the {x, y} syntax to specifically specify the desired length.

However, if you really do need non-greedy repetition, I suggest consulting the all-powerful ?. This, when placed after at the end of any regex repetition specifier, will force that part of the regex to find the least amount of text possible.

That being said, I would be very careful with the ? as it, like the Sonic Screwdriver in Dr. Who, has a tendency to do, how should I put it, "slightly" undesired things if not carefully calibrated. For example, to use your example input, it would identify ((1) (note the lack of a second rparen) as a match.

Could not load file or assembly 'System.Web.Http 4.0.0 after update from 2012 to 2013

Or you could do this from NuGet Package Manager Console

 Install-Package Microsoft.AspNet.WebApi -Version 5.0.0

And then you will be able to add the reference to System.Web.Http.WebHost 5.0

In C#, what's the difference between \n and \r\n?

\n is the line break used by Unix(-like) systems, \r\n is used by windows. This has nothing to do with C#.

How to programmatically log out from Facebook SDK 3.0 without using Facebook login/logout button?

Here is snippet that allowed me to log out programmatically from facebook. Let me know if you see anything that I might need to improve.

private void logout(){
    // clear any user information
    mApp.clearUserPrefs();
    // find the active session which can only be facebook in my app
    Session session = Session.getActiveSession();
    // run the closeAndClearTokenInformation which does the following
    // DOCS : Closes the local in-memory Session object and clears any persistent 
    // cache related to the Session.
    session.closeAndClearTokenInformation();
    // return the user to the login screen
    startActivity(new Intent(getApplicationContext(), LoginActivity.class));
    // make sure the user can not access the page after he/she is logged out
    // clear the activity stack
    finish();
}

Multiple variables in a 'with' statement?

Note that if you split the variables into lines, you must use backslashes to wrap the newlines.

with A() as a, \
     B() as b, \
     C() as c:
    doSomething(a,b,c)

Parentheses don't work, since Python creates a tuple instead.

with (A(),
      B(),
      C()):
    doSomething(a,b,c)

Since tuples lack a __enter__ attribute, you get an error (undescriptive and does not identify class type):

AttributeError: __enter__

If you try to use as within parentheses, Python catches the mistake at parse time:

with (A() as a,
      B() as b,
      C() as c):
    doSomething(a,b,c)
SyntaxError: invalid syntax

When will this be fixed?

This issue is tracked in https://bugs.python.org/issue12782.

Recently, Python announced in PEP 617 that they'll be replacing the current parser with a new one. Because Python's current parser is LL(1), it cannot distinguish between "multiple context managers" with (A(), B()): and "tuple of values" with (A(), B())[0]:.

The new parser can properly parse "multiple context managers" surrounded by tuples. The new parser will be enabled in 3.9, but this syntax will still be rejected until the old parser is removed in Python 3.10.

Check if a specific value exists at a specific key in any subarray of a multidimensional array

function checkMultiArrayValue($array) {
        global $test;
        foreach ($array as $key => $item) {

            if(!empty($item) && is_array($item)) {
                checkMultiArrayValue($item);
            }else {
                if($item)
                 $test[$key] = $item;

            }
        }
        return $test;   
    }

 $multiArray = array(    
                0 =>  array(  
                      "country"   => "",  
                      "price"    => 4,  
                      "discount-price" => 0,  
               ),);

$test = checkMultiArrayValue($multiArray);
echo "<pre>"
print_r($test);

Will return array who have index and value

ORA-28040: No matching authentication protocol exception

I was using eclipse and after trying all the other answers it didn't work for me. In the end, what worked for me was moving the ojdb7.jar to top in the Build Path. This occurs when multiple jars have conflicting same classes.

  1. Select project in Project Explorer
  2. Right click on Project -> Build Path -> Configure Build Path
  3. Go to Order and Export tab and select ojdbc.jar
  4. Click button TOP to move it to top

XCOPY: Overwrite all without prompt in BATCH

The solution is the /Y switch:

xcopy "C:\Users\ADMIN\Desktop\*.*" "D:\Backup\" /K /D /H /Y

Find in Files: Search all code in Team Foundation Server

We have set up a solution for Team Foundation Server Source Control (not SourceSafe as you mention) similar to what Grant suggests; scheduled TF Get, Search Server Express. However the IFilter used for C# files (text) was not giving the results we wanted, so we convert source files to .htm files. We can now add additional meta-data to the files such as:

  • Author (we define it as the person that last checked in the file)
  • Color coding (on our todo-list)
  • Number of changes indicating potential design problems (on our todo-list)
  • Integrate with the VSTS IDE like Koders SmartSearch feature
  • etc.

We would however prefer a protocolhandler for TFS Source Control, and a dedicated source code IFilter for a much more targeted solution.

Angular2 QuickStart npm start is not working correctly

This answer is for Windows 10 users only and as you'll see below, I suspect the problem is happening only for those users:

To find out what is happening, you can run the command on PowerShell and it will tell you what is the actual problem:

PS C:\Users\Laurent-Philippe> tsc && concurrently "tsc -w" "lite-server"
At line:1 char:5
+ tsc && concurrently "tsc -w" "lite-server"
+     ~~
The token '&&' is not a valid statement separator in this version.
    + CategoryInfo          : ParserError: (:) [], ParentContainsErrorRecordException
    + FullyQualifiedErrorId : InvalidEndOfLine

Basically, the message explains that the token "&&" is not yet valid with Windows 10. And for those wondering, the same command replacing && with &, informed us that the ampersand operator is reserved for future use:

 (&) character is not allowed. The & operator is reserved for future use; wrap an ampersand in double quotation marks ("&") to pass it as part of a string.

Conclusions:

  • if you want to manually launch this command from the powershell, you can use this instead:

    tsc "&" concurrently "tsc -w" "lite-server"

  • if you want to launch your application with npm start, replace the start line in your package.json by:

    "start": "tsc & concurrently \"tsc -w\" \"lite-server\" "

  • alternatively, the answer of user60108 also works because he is not using the ampersand:

    "start": "concurrently \"npm run tsc:w\" \"npm run lite\" "

batch file Copy files with certain extensions from multiple directories into one directory

Things like these are why I switched to Powershell. Try it out, it's fun:

Get-ChildItem -Recurse -Include *.doc | % {
    Copy-Item $_.FullName -destination x:\destination
}

Killing a process created with Python's subprocess.Popen()

Only use Popen kill method

process = subprocess.Popen(
    task.getExecutable(), 
    stdout=subprocess.PIPE, 
    stderr=subprocess.PIPE, 
    shell=True
)
process.kill()

html cellpadding the left side of a cell

Well, as suggested by Hellfire you can use td width or you could place an element in the td and adjust its width. We could not use

CSS property Padding

as in Microsoft Outlook padding does not work. So what I had to do is,

<table>
    <tr>
        <td><span style="display: inline-block; width: 40px;"></span><span>Content<span></td>
        <td>Content</td>
    </tr>
</table>

With this you can adjust right and left spacing. For top and bottom spacing you could use td's height property. Like,

 <table>
        <tr>
            <td style="vertical-align: top; height: 100px;">Content</td>
            <td>Content</td>
        </tr>
    </table>

This will increase bottom space.

Hope it will work for you guys. :)

How can I programmatically determine if my app is running in the iphone simulator?

I had the same problem, both TARGET_IPHONE_SIMULATOR and TARGET_OS_IPHONE are always defined, and are set to 1. Pete's solution works, of course, but if you ever happen to build on something other than intel (unlikely, but who knows), here's something that's safe as long as the iphone hardware doesn't change (so your code will always work for the iphones currently out there):

#if defined __arm__ || defined __thumb__
#undef TARGET_IPHONE_SIMULATOR
#define TARGET_OS_IPHONE
#else
#define TARGET_IPHONE_SIMULATOR 1
#undef TARGET_OS_IPHONE
#endif

Put that somewhere convenient, and then pretend that the TARGET_* constants were defined correctly.

Error in eval(expr, envir, enclos) : object not found

Don't know why @Janos deleted his answer, but it's correct: your data frame Train doesn't have a column named pre. When you pass a formula and a data frame to a model-fitting function, the names in the formula have to refer to columns in the data frame. Your Train has columns called residual.sugar, total.sulfur, alcohol and quality. You need to change either your formula or your data frame so they're consistent with each other.

And just to clarify: Pre is an object containing a formula. That formula contains a reference to the variable pre. It's the latter that has to be consistent with the data frame.

How to Lazy Load div background images

First you need to think off when you want to swap. For example you could switch everytime when its a div tag thats loaded. In my example i just used a extra data field "background" and whenever its set the image is applied as a background image.

Then you just have to load the Data with the created image tag. And not overwrite the img tag instead apply a css background image.

Here is a example of the code change:

if (settings.appear) {
    var elements_left = elements.length;
    settings.appear.call(self, elements_left, settings);
}
var loadImgUri;
if($self.data("background"))
    loadImgUri = $self.data("background");
else
    loadImgUri  = $self.data(settings.data_attribute);

$("<img />")
    .bind("load", function() {
        $self
            .hide();
        if($self.data("background")){
            $self.css('backgroundImage', 'url('+$self.data("background")+')');
        }else
            $self.attr("src", $self.data(settings.data_attribute))

        $self[settings.effect](settings.effect_speed);

        self.loaded = true;

        /* Remove image from array so it is not looped next time. */
        var temp = $.grep(elements, function(element) {
            return !element.loaded;
        });
        elements = $(temp);

        if (settings.load) {
            var elements_left = elements.length;
            settings.load.call(self, elements_left, settings);
        }
    })
    .attr("src", loadImgUri );
}

the loading stays the same

$("#divToLoad").lazyload();

and in this example you need to modify the html code like this:

<div data-background="http://apod.nasa.gov/apod/image/9712/orionfull_jcc_big.jpg" id="divToLoad" />?

but it would also work if you change the switch to div tags and then you you could work with the "data-original" attribute.

Here's an fiddle example: http://jsfiddle.net/dtm3k/1/

Import / Export database with SQL Server Server Management Studio

Right click the database itself, Tasks -> Generate Scripts...

Then follow the wizard.

For SSMS2008+, if you want to also export the data, on the "Set Scripting Options" step, select the "Advanced" button and change "Types of data to script" from "Schema Only" to "Data Only" or "Schema and Data".

Operand type clash: uniqueidentifier is incompatible with int

If you're accessing this via a View then try sp_recompile or refreshing views.

sp_recompile:

Causes stored procedures, triggers, and user-defined functions to be recompiled the next time that they are run. It does this by dropping the existing plan from the procedure cache forcing a new plan to be created the next time that the procedure or trigger is run. In a SQL Server Profiler collection, the event SP:CacheInsert is logged instead of the event SP:Recompile.

Arguments

[ @objname= ] 'object'

The qualified or unqualified name of a stored procedure, trigger, table, view, or user-defined function in the current database. object is nvarchar(776), with no default. If object is the name of a stored procedure, trigger, or user-defined function, the stored procedure, trigger, or function will be recompiled the next time that it is run. If object is the name of a table or view, all the stored procedures, triggers, or user-defined functions that reference the table or view will be recompiled the next time that they are run.

Return Code Values

0 (success) or a nonzero number (failure)

Remarks

sp_recompile looks for an object in the current database only.

The queries used by stored procedures, or triggers, and user-defined functions are optimized only when they are compiled. As indexes or other changes that affect statistics are made to the database, compiled stored procedures, triggers, and user-defined functions may lose efficiency. By recompiling stored procedures and triggers that act on a table, you can reoptimize the queries.

Typescript empty object for a typed variable

Note that using const user = {} as UserType just provides intellisense but at runtime user is empty object {} and has no property inside. that means user.Email will give undefined instead of ""

type UserType = {
    Username: string;
    Email: string;
}

So, use class with constructor for actually creating objects with default properties.

type UserType = {
  Username: string;
  Email: string;
};

class User implements UserType {
  constructor() {
    this.Username = "";
    this.Email = "";
  }

  Username: string;
  Email: string;
}

const myUser = new User();
console.log(myUser); // output: {Username: "", Email: ""}
console.log("val: "+myUser.Email); // output: ""

You can also use interface instead of type

interface UserType {
  Username: string;
  Email: string;
};

...and rest of code remains same.


Actually, you can even skip the constructor part and use it like this:

class User implements UserType {
      Username = ""; // will be added to new obj
      Email: string; // will not be added
}

const myUser = new User();
console.log(myUser); // output: {Username: ""}

Read connection string from web.config

You need to add a reference to System.Configuration and then use:

System.Configuration.ConfigurationManager.
    ConnectionStrings["connectionStringName"].ConnectionString;

How to print Boolean flag in NSLog?

Apple's FixIt supplied %hhd, which correctly gave me the value of my BOOL.

Android difference between Two Dates

I arranged a little. This works great.

@SuppressLint("SimpleDateFormat") SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd MM yyyy");
    Date date = new Date();
    String dateOfDay = simpleDateFormat.format(date);

    String timeofday = android.text.format.DateFormat.format("HH:mm:ss", new Date().getTime()).toString();

    @SuppressLint("SimpleDateFormat") SimpleDateFormat dateFormat = new SimpleDateFormat("dd MM yyyy hh:mm:ss");
    try {
        Date date1 = dateFormat.parse(06 09 2018 + " " + 10:12:56);
        Date date2 = dateFormat.parse(dateOfDay + " " + timeofday);

        printDifference(date1, date2);

    } catch (ParseException e) {
        e.printStackTrace();
    }

@SuppressLint("SetTextI18n")
private void printDifference(Date startDate, Date endDate) {
    //milliseconds
    long different = endDate.getTime() - startDate.getTime();

    long secondsInMilli = 1000;
    long minutesInMilli = secondsInMilli * 60;
    long hoursInMilli = minutesInMilli * 60;
    long daysInMilli = hoursInMilli * 24;

    long elapsedDays = different / daysInMilli;
    different = different % daysInMilli;

    long elapsedHours = different / hoursInMilli;
    different = different % hoursInMilli;

    long elapsedMinutes = different / minutesInMilli;
    different = different % minutesInMilli;

    long elapsedSeconds = different / secondsInMilli;

Toast.makeText(context, elapsedDays + " " + elapsedHours + " " + elapsedMinutes + " " + elapsedSeconds, Toast.LENGTH_SHORT).show();
}

How to extract code of .apk file which is not working?

Click here this is a good tutorial for both window/ubuntu.

  1. apktool1.5.1.jar download from here.

  2. apktool-install-linux-r05-ibot download from here.

  3. dex2jar-0.0.9.15.zip download from here.

  4. jd-gui-0.3.3.linux.i686.tar.gz (java de-complier) download from here.

  5. framework-res.apk ( Located at your android device /system/framework/)

Procedure:

  1. Rename the .apk file and change the extension to .zip ,

it will become .zip.

  1. Then extract .zip.

  2. Unzip downloaded dex2jar-0.0.9.15.zip file , copy the contents and paste it to unzip folder.

  3. Open terminal and change directory to unzip “dex2jar-0.0.9.15 “

– cd – sh dex2jar.sh classes.dex (result of this command “classes.dex.dex2jar.jar” will be in your extracted folder itself).

  1. Now, create new folder and copy “classes.dex.dex2jar.jar” into it.

  2. Unzip “jd-gui-0.3.3.linux.i686.zip“ and open up the “Java Decompiler” in full screen mode.

  3. Click on open file and select “classes.dex.dex2jar.jar” into the window.

  4. “Java Decompiler” and go to file > save and save the source in a .zip file.

  5. Create “source_code” folder.

  6. Extract the saved .zip and copy the contents to “source_code” folder.

  7. This will be where we keep your source code.

  8. Extract apktool1.5.1.tar.bz2 , you get apktool.jar

  9. Now, unzip “apktool-install-linux-r05-ibot.zip”

  10. Copy “framework-res.apk” , “.apk” and apktool.jar

  11. Paste it to the unzip “apktool-install-linux-r05-ibot” folder (line no 13).

  12. Then open terminal and type:

    – cd

    – chown -R : ‘apktool.jar’

    – chown -R : ‘apktool’

    – chown -R : ‘aapt’

    – sudo chmod +x ‘apktool.jar’

    – sudo chmod +x ‘apktool’

    – sudo chmod +x ‘aapt’

    – sudo mv apktool.jar /usr/local/bin

    – sudo mv apktool /usr/local/bin

    – sudo mv aapt /usr/local/bin

    – apktool if framework-res.apk – apktool d .apk

Plotting dates on the x-axis with Python's matplotlib

I have too low reputation to add comment to @bernie response, with response to @user1506145. I have run in to same issue.

1

The answer to it is a interval parameter which fixes things up

2

import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import numpy as np
import datetime as dt

np.random.seed(1)

N = 100
y = np.random.rand(N)

now = dt.datetime.now()
then = now + dt.timedelta(days=100)
days = mdates.drange(now,then,dt.timedelta(days=1))

plt.gca().xaxis.set_major_formatter(mdates.DateFormatter('%Y-%m-%d'))
plt.gca().xaxis.set_major_locator(mdates.DayLocator(interval=5))
plt.plot(days,y)
plt.gcf().autofmt_xdate()
plt.show()

symbol(s) not found for architecture i386

In my case none of the posted solutions worked. I had to delete the project and make a fresh checkout from the SVN server. Lucky me the project was hosted in a version control system. Don't know what I'd do otherwise.

Ascending and Descending Number Order in java

Just sort the array in ascending order and print it backwards.

Arrays.sort(arr);
for(int i = arr.length-1; i >= 0 ; i--) {
    //print arr[i]
}

How does one reorder columns in a data frame?

Your dataframe has four columns like so df[,c(1,2,3,4)]. Note the first comma means keep all the rows, and the 1,2,3,4 refers to the columns.

To change the order as in the above question do df2[,c(1,3,2,4)]

If you want to output this file as a csv, do write.csv(df2, file="somedf.csv")

How to fix Terminal not loading ~/.bashrc on OS X Lion

Renaming .bashrc to .profile (or soft-linking the latter to the former) should also do the trick. See here.

Check if an element has event listener on it. No jQuery

There is no JavaScript function to achieve this. However, you could set a boolean value to true when you add the listener, and false when you remove it. Then check against this boolean before potentially adding a duplicate event listener.

Possible duplicate: How to check whether dynamically attached event listener exists or not?

python : list index out of range error while iteratively popping elements

What Mark Rushakoff said is true, but if you iterate in the opposite direction, it is possible to remove elements from the list in the for-loop as well. E.g.,

x = [1,2,3,0,0,1]
for i in range(len(x)-1, -1, -1):
    if x[i] == 0:
        x.pop(i)

It's like a tall building that falls from top to bottom: even if it is in the middle of collapse, you still can "enter" into it and visit yet-to-be-collapsed floors.

android: data binding error: cannot find symbol class

You can see Main Answer for complete information about data binding errors and solutions. I will try to tell some important points below.

5 Tips that I use to solve binding issues.

Assuming that you have enabled data binding in build.gradle and you have converted your layout to binding layout.

First of all binding class auto generate when you convert layout to binding layout. Still sometimes it is not generated when background threads are not working. Here are some tips for you to resolve this.

(1) Name of generated class

Layout name is in snake_case activity_main.xml

Data binding class will be in PascalCase like ActivityMainBinding.

(2). Type full name of Binding class

I felt sometimes when you type ActivityMai..., then it does not show suggestion, but that does not mean class is not generated. In that case you should type full name of expected generated class. Like type ActivityMainBinding and it will show import popup. (That's what i faced many times.)

Still not getting import suggestion. Try manual import.

import <yourpackage>databinding.ActivityMainBinding;

(3). Rebuild Project

If still your class is not generated. (Some time when we paste layout file, then it happens). Then Rebuild Project from Build> Rebuild (Not Build or Make project). It will generate your data binding class. (Rebuild does Magic for me all times.)

(4) If you have created an <variable in your layout and it does not show up its setter and getter in data binding class, then follow 4th point.

(5) Still if your class is not generating then you should check if build is not failing due to an error in your layout file. Data binding class will generate with a successful build.

This is all what i do to solve my data binding errors. If you get any further issue, you can comment here.

Source answer

Is it possible to use JS to open an HTML select to show its option list?

<select id="myDropDown">
  <option>html5</option>
  <option>javascript</option>
  <option>jquery</option>
  <option>css</option>
  <option>sencha</option>
</select>

By jQuery:

var myDropDown=$("#myDropDown");
var length = $('#myDropDown> option').length;
//open dropdown
myDropDown.attr('size',length);
//close dropdown
myDropDown.attr('size',0);

By javascript:

var myDropDown=document.getElementById("myDropDown");
var length = myDropDown.options.length;
//open dropdown
myDropDown.size = length;
//close dropdown
myDropDown.size = 0;

Copied from: Open close select

Adding values to an array in java

You always set x to 0 before changing array's value.

You can use:

int[] tall = new int[28123];

for (int j = 0;j<28123;j++){
    // Or whatever value you want to set.
    tall[j] = j + 1;
}

Or just remove the initialization of x (int x=0) before the for loop.

Change button text from Xcode?

If you've got a button that's hooked up to an action in your code, you can change the title without an instance variable.

For example, if the button is set to this action:

-(IBAction)startSomething:(id)sender;

You can simply do this in the method:

-(IBAction)startSomething:(id)sender {
    [sender setTitle:@"Hello" forState:UIControlStateNormal];
}

Or if you're wanting to toggle the name of the button, you can create a BOOL named "buttonToggled" (for example), and toggle the name this way:

-(IBAction)toggleButton:(id)sender {
    if (!buttonToggled) {
        [sender setTitle:@"Something" forState:UIControlStateNormal];
        buttonToggled = YES;
    }
    else {
        [sender setTitle:@"Different" forState:UIControlStateNormal];
        buttonToggled = NO;
    }
}

What is the purpose and use of **kwargs?

  • kwargs in **kwargs is just variable name. You can very well have **anyVariableName
  • kwargs stands for "keyword arguments". But I feel they should better be called as "named arguments", as these are simply arguments passed along with names (I dont find any significance to the word "keyword" in the term "keyword arguments". I guess "keyword" usually means words reserved by programming language and hence not to be used by the programmer for variable names. No such thing is happening here in case of kwargs.). So we give names param1 and param2 to two parameter values passed to the function as follows: func(param1="val1",param2="val2"), instead of passing only values: func(val1,val2). Thus, I feel they should be appropriately called "arbitrary number of named arguments" as we can specify any number of these parameters (that is, arguments) if func has signature func(**kwargs)

So being said that let me explain "named arguments" first and then "arbitrary number of named arguments" kwargs.

Named arguments

  • named args should follow positional args
  • order of named args is not important
  • Example

    def function1(param1,param2="arg2",param3="arg3"):
        print("\n"+str(param1)+" "+str(param2)+" "+str(param3)+"\n")
    
    function1(1)                      #1 arg2 arg3   #1 positional arg
    function1(param1=1)               #1 arg2 arg3   #1 named arg
    function1(1,param2=2)             #1 2 arg3      #1 positional arg, 1 named arg
    function1(param1=1,param2=2)      #1 2 arg3      #2 named args       
    function1(param2=2, param1=1)     #1 2 arg3      #2 named args out of order
    function1(1, param3=3, param2=2)  #1 2 3         #
    
    #function1()                      #invalid: required argument missing
    #function1(param2=2,1)            #invalid: SyntaxError: non-keyword arg after keyword arg
    #function1(1,param1=11)           #invalid: TypeError: function1() got multiple values for argument 'param1'
    #function1(param4=4)              #invalid: TypeError: function1() got an unexpected keyword argument 'param4'
    

Arbitrary number of named arguments kwargs

  • Sequence of function parameters:
    1. positional parameters
    2. formal parameter capturing arbitrary number of arguments (prefixed with *)
    3. named formal parameters
    4. formal parameter capturing arbitrary number of named parameters (prefixed with **)
  • Example

    def function2(param1, *tupleParams, param2, param3, **dictionaryParams):
        print("param1: "+ param1)
        print("param2: "+ param2)
        print("param3: "+ param3)
        print("custom tuple params","-"*10)
        for p in tupleParams:
            print(str(p) + ",")
        print("custom named params","-"*10)
        for k,v in dictionaryParams.items():
            print(str(k)+":"+str(v))
    
    function2("arg1",
              "custom param1",
              "custom param2",
              "custom param3",
              param3="arg3",
              param2="arg2", 
              customNamedParam1 = "val1",
              customNamedParam2 = "val2"
              )
    
    # Output
    #
    #param1: arg1
    #param2: arg2
    #param3: arg3
    #custom tuple params ----------
    #custom param1,
    #custom param2,
    #custom param3,
    #custom named params ----------
    #customNamedParam2:val2
    #customNamedParam1:val1
    

Passing tuple and dict variables for custom args

To finish it up, let me also note that we can pass

  • "formal parameter capturing arbitrary number of arguments" as tuple variable and
  • "formal parameter capturing arbitrary number of named parameters" as dict variable

Thus the same above call can be made as follows:

tupleCustomArgs = ("custom param1", "custom param2", "custom param3")
dictCustomNamedArgs = {"customNamedParam1":"val1", "customNamedParam2":"val2"}

function2("arg1",
      *tupleCustomArgs,    #note *
      param3="arg3",
      param2="arg2", 
      **dictCustomNamedArgs     #note **
      )

Finally note * and ** in function calls above. If we omit them, we may get ill results.

Omitting * in tuple args:

function2("arg1",
      tupleCustomArgs,   #omitting *
      param3="arg3",
      param2="arg2", 
      **dictCustomNamedArgs
      )

prints

param1: arg1
param2: arg2
param3: arg3
custom tuple params ----------
('custom param1', 'custom param2', 'custom param3'),
custom named params ----------
customNamedParam2:val2
customNamedParam1:val1

Above tuple ('custom param1', 'custom param2', 'custom param3') is printed as is.

Omitting dict args:

function2("arg1",
      *tupleCustomArgs,   
      param3="arg3",
      param2="arg2", 
      dictCustomNamedArgs   #omitting **
      )

gives

dictCustomNamedArgs
         ^
SyntaxError: non-keyword arg after keyword arg

Wrap text in <td> tag

table-layout:fixed will resolve the expanding cell problem, but will create a new one. IE by default will hide the overflow but Mozilla will render it outside the box.

Another solution would be to use: overflow:hidden;width:?px

<table style="table-layout:fixed; width:100px">
 <tr>
   <td style="overflow:hidden; width:50px;">fearofthedarkihaveaconstantfearofadark</td>
   <td>
     test
   </td>
 </tr>
</table>

What are ODEX files in Android?

This Blog article explains the internals of ODEX files:

WHAT IS AN ODEX FILE?

In Android file system, applications come in packages with the extension .apk. These application packages, or APKs contain certain .odex files whose supposed function is to save space. These ‘odex’ files are actually collections of parts of an application that are optimized before booting. Doing so speeds up the boot process, as it preloads part of an application. On the other hand, it also makes hacking those applications difficult because a part of the coding has already been extracted to another location before execution.

How do you convert CString and std::string std::wstring to each other?

One interesting approach is to cast CString to CStringA inside a string constructor. Unlike std::string s((LPCTSTR)cs); this will work even if _UNICODE is defined. However, if that is the case, this will perform conversion from Unicode to ANSI, so it is unsafe for higher Unicode values beyond the ASCII character set. Such conversion is subject to the _CSTRING_DISABLE_NARROW_WIDE_CONVERSION preprocessor definition. https://msdn.microsoft.com/en-us/library/5bzxfsea.aspx

        CString s1("SomeString");
        string s2((CStringA)s1);

How should I escape commas and speech marks in CSV files so they work in Excel?

According to Yashu's instructions, I wrote the following function (it's PL/SQL code, but it should be easily adaptable to any other language).

FUNCTION field(str IN VARCHAR2) RETURN VARCHAR2 IS
    C_NEWLINE CONSTANT CHAR(1) := '
'; -- newline is intentional

    v_aux VARCHAR2(32000);
    v_has_double_quotes BOOLEAN;
    v_has_comma BOOLEAN;
    v_has_newline BOOLEAN;
BEGIN
    v_has_double_quotes := instr(str, '"') > 0;
    v_has_comma := instr(str,',') > 0;
    v_has_newline := instr(str, C_NEWLINE) > 0;

    IF v_has_double_quotes OR v_has_comma OR v_has_newline THEN
        IF v_has_double_quotes THEN
            v_aux := replace(str,'"','""');
        ELSE
            v_aux := str;
        END IF;
        return '"'||v_aux||'"';
    ELSE
        return str;
    END IF;
END;

Get selected option text with JavaScript

 <select class="cS" onChange="fSel2(this.value);">
     <option value="0">S?lectionner</option>
     <option value="1">Un</option>
     <option value="2" selected>Deux</option>
     <option value="3">Trois</option>
 </select>

 <select id="iS1" onChange="fSel(options[this.selectedIndex].value);">
     <option value="0">S?lectionner</option>
     <option value="1">Un</option>
     <option value="2" selected>Deux</option>
     <option value="3">Trois</option>
 </select><br>

 <select id="iS2" onChange="fSel3(options[this.selectedIndex].text);">
     <option value="0">S?lectionner</option>
     <option value="1">Un</option>
     <option value="2" selected>Deux</option>
     <option value="3">Trois</option>
 </select>

 <select id="iS3" onChange="fSel3(options[this.selectedIndex].textContent);">
     <option value="0">S?lectionner</option>
     <option value="1">Un</option>
     <option value="2" selected>Deux</option>
     <option value="3">Trois</option>
 </select>

 <select id="iS4" onChange="fSel3(options[this.selectedIndex].label);">
     <option value="0">S?lectionner</option>
     <option value="1">Un</option>
     <option value="2" selected>Deux</option>
     <option value="3">Trois</option>
 </select>

 <select id="iS4" onChange="fSel3(options[this.selectedIndex].innerHTML);">
     <option value="0">S?lectionner</option>
     <option value="1">Un</option>
     <option value="2" selected>Deux</option>
     <option value="3">Trois</option>
 </select>

 <script type="text/javascript"> "use strict";
   const s=document.querySelector(".cS");

 // options[this.selectedIndex].value
 let fSel = (sIdx) => console.log(sIdx,
     s.options[sIdx].text, s.options[sIdx].textContent, s.options[sIdx].label);

 let fSel2= (sIdx) => { // this.value
     console.log(sIdx, s.options[sIdx].text,
         s.options[sIdx].textContent, s.options[sIdx].label);
 }

 // options[this.selectedIndex].text
 // options[this.selectedIndex].textContent
 // options[this.selectedIndex].label
 // options[this.selectedIndex].innerHTML
 let fSel3= (sIdx) => {
     console.log(sIdx);
 }
 </script> // fSel

But :

 <script type="text/javascript"> "use strict";
    const x=document.querySelector(".cS"),
          o=x.options, i=x.selectedIndex;
    console.log(o[i].value,
                o[i].text , o[i].textContent , o[i].label , o[i].innerHTML);
 </script> // .cS"

And also this :

 <select id="iSel" size="3">
     <option value="one">Un</option>
     <option value="two">Deux</option>
     <option value="three">Trois</option>
 </select>


 <script type="text/javascript"> "use strict";
    const i=document.getElementById("iSel");
    for(let k=0;k<i.length;k++) {
        if(k == i.selectedIndex) console.log("Selected ".repeat(3));
        console.log(`${Object.entries(i.options)[k][1].value}`+
                    ` => ` +
                    `${Object.entries(i.options)[k][1].innerHTML}`);
        console.log(Object.values(i.options)[k].value ,
                    " => ",
                    Object.values(i.options)[k].innerHTML);
        console.log("=".repeat(25));
    }
 </script>

event.preventDefault() vs. return false

From my experience event.stopPropagation() is mostly used in CSS effect or animation works, for instance when you have hover effect for both card and button element, when you hover on the button both card and buttons hover effect will be triggered in this case, you can use event.stopPropagation() stop bubbling actions, and event.preventDefault() is for prevent default behaviour of browser actions. For instance, you have form but you only defined click event for the submit action, if the user submits the form by pressing enter, the browser triggered by keypress event, not your click event here you should use event.preventDefault() to avoid inappropriate behavior. I don't know what the hell is return false; sorry.For more clarification visit this link and play around with line #33 https://www.codecademy.com/courses/introduction-to-javascript/lessons/requests-i/exercises/xhr-get-request-iv

What are the differences in die() and exit() in PHP?

From what I know when I look at this question here

It said there that "in PHP, there is a distinct difference in Header output. In the examples below I chose to use a different header but for sake of showing the difference between exit() and die() that doesn't matter", and tested (personally)

Why does the Google Play store say my Android app is incompatible with my own device?

I have experienced this problem too while developing an application for a customer that wanted to have videos offline available from their application. I have written a blogpost about why the app I worked on for months wouldn't show up in the play store for my device (post can be found here). I found the same as @Greg Hewgill found: Cache partition limitations on some devices.

The journey didn't stop for me there. The customer wanted to have these videos in the application and didn't want the quality of the video to be decreased. After some research I figured out that using expansion files was the perfect solution to our problem.

To share my knowledge with the Android community I held a talk at droidconNL 2012 about expansion files. I created a presentation and sample code to illustrate how easy it can be to start using expansion files. For any of you out there wanting to use expansion files to solve this problem feel free to check out the post containing the presentation and the sample code

Is it possible to CONTINUE a loop from an exception?

In the construct you have provided, you don't need a CONTINUE. Once the exception is handled, the statement after the END is performed, assuming your EXCEPTION block doesn't terminate the procedure. In other words, it will continue on to the next iteration of the user_rec loop.

You also need to SELECT INTO a variable inside your BEGIN block:

SELECT attr INTO v_attr FROM attribute_table...

Obviously you must declare v_attr as well...

Barcode scanner for mobile phone for Website in form

You can use the Android app Barcode Scanner Terminal (DISCLAIMER! I'm the developer). It can scan the barcode and send it to the PC and in your case enter it on the web form. More details here.

Python regex findall

you can replace your pattern with

regex = ur"\[P\]([\w\s]+)\[\/P\]"

How do I make Git use the editor of my choice for commits?

Atom as your git editor

git config --global core.editor "atom --wait"

Atom needs to be configured to run from the command line for the above to work:

OS X: install shell commands from Atom: menu bar > Atom > Install Shell Commands

Windows: no action required - atom is configured to run from the command line by default

JavaScript code to stop form submission

Use prevent default

Dojo Toolkit

dojo.connect(form, "onsubmit", function(evt) {
    evt.preventDefault();
    window.history.back();
});

jQuery

$('#form').submit(function (evt) {
    evt.preventDefault();
    window.history.back();
});

Vanilla JavaScript

if (element.addEventListener) {
    element.addEventListener("submit", function(evt) {
        evt.preventDefault();
        window.history.back();
    }, true);
}
else {
    element.attachEvent('onsubmit', function(evt){
        evt.preventDefault();
        window.history.back();
    });
}

Date format in dd/MM/yyyy hh:mm:ss

You could combine 2 formats:

3   dd/mm/yy   (British/French)
8   hh:mm:ss

according to CONVERT() function, and using + operator:

SELECT CONVERT(varchar(10),GETDATE(),3) + ' ' + CONVERT(varchar(10),GETDATE(),8)

Android - implementing startForeground for a service?

I'd start by completely filling in the Notification. Here is a sample project demonstrating the use of startForeground().

Git and nasty "error: cannot lock existing info/refs fatal"

Aside from the many answers already supplied to this question, a simple check on the local repo branches that exist in your machine and those that don't in the remote, will help. In which case you don't use the

git prune

command as many have suggested.

Simply delete the local branch

git branch -d <branch name without a remote tracking branch by the same name>

as shown in the attached screenshot using -D to force delete when you are sure that a local branch does not have a remote branch tracked.

lock ref error git

How to run shell script on host from docker container?

You can use the pipe concept, but use a file on the host and fswatch to accomplish the goal to execute a script on the host machine from a docker container. Like so (Use at your own risk):

#! /bin/bash

touch .command_pipe
chmod +x .command_pipe

# Use fswatch to execute a command on the host machine and log result
fswatch -o --event Updated .command_pipe | \
            xargs -n1 -I "{}"  .command_pipe >> .command_pipe_log  &

 docker run -it --rm  \
   --name alpine  \
   -w /home/test \
   -v $PWD/.command_pipe:/dev/command_pipe \
   alpine:3.7 sh

rm -rf .command_pipe
kill %1

In this example, inside the container send commands to /dev/command_pipe, like so:

/home/test # echo 'docker network create test2.network.com' > /dev/command_pipe

On the host, you can check if the network was created:

$ docker network ls | grep test2
8e029ec83afe        test2.network.com                            bridge              local

How to call loading function with React useEffect only once

TL;DR

useEffect(yourCallback, []) - will trigger the callback only after the first render.

Detailed explanation

useEffect runs by default after every render of the component (thus causing an effect).

When placing useEffect in your component you tell React you want to run the callback as an effect. React will run the effect after rendering and after performing the DOM updates.

If you pass only a callback - the callback will run after each render.

If passing a second argument (array), React will run the callback after the first render and every time one of the elements in the array is changed. for example when placing useEffect(() => console.log('hello'), [someVar, someOtherVar]) - the callback will run after the first render and after any render that one of someVar or someOtherVar are changed.

By passing the second argument an empty array, React will compare after each render the array and will see nothing was changed, thus calling the callback only after the first render.

How to generate the JPA entity Metamodel?

It would be awesome if someone also knows the steps for setting this up in Eclipse (I assume it's as simple as setting up an annotation processor, but you never know)

Yes it is. Here are the implementations and instructions for the various JPA 2.0 implementations:

EclipseLink

Hibernate

OpenJPA

DataNucleus


The latest Hibernate implementation is available at:

An older Hibernate implementation is at:

What is the fastest/most efficient way to find the highest set bit (msb) in an integer in C?

As the answers above point out, there are a number of ways to determine the most significant bit. However, as was also pointed out, the methods are likely to be unique to either 32bit or 64bit registers. The stanford.edu bithacks page provides solutions that work for both 32bit and 64bit computing. With a little work, they can be combined to provide a solid cross-architecture approach to obtaining the MSB. The solution I arrived at that compiled/worked across 64 & 32 bit computers was:

#if defined(__LP64__) || defined(_LP64)
# define BUILD_64   1
#endif

#include <stdio.h>
#include <stdint.h>  /* for uint32_t */

/* CHAR_BIT  (or include limits.h) */
#ifndef CHAR_BIT
#define CHAR_BIT  8
#endif  /* CHAR_BIT */

/* 
 * Find the log base 2 of an integer with the MSB N set in O(N)
 * operations. (on 64bit & 32bit architectures)
 */
int
getmsb (uint32_t word)
{
    int r = 0;
    if (word < 1)
        return 0;
#ifdef BUILD_64
    union { uint32_t u[2]; double d; } t;  // temp
    t.u[__FLOAT_WORD_ORDER==LITTLE_ENDIAN] = 0x43300000;
    t.u[__FLOAT_WORD_ORDER!=LITTLE_ENDIAN] = word;
    t.d -= 4503599627370496.0;
    r = (t.u[__FLOAT_WORD_ORDER==LITTLE_ENDIAN] >> 20) - 0x3FF;
#else
    while (word >>= 1)
    {
        r++;
    }
#endif  /* BUILD_64 */
    return r;
}

Monitoring the Full Disclosure mailinglist

Two generic ways to do the same thing... I'm not aware of any specific open solutions to do this, but it'd be rather trivial to do.

You could write a daily or weekly cron/jenkins job to scrape the previous time period's email from the archive looking for your keyworkds/combinations. Sending a batch digest with what it finds, if anything.

But personally, I'd Setup a specific email account to subscribe to the various security lists you're interested in. Add a simple automated script to parse the new emails for various keywords or combinations of keywords, when it finds a match forward that email on to you/your team. Just be sure to keep the keywords list updated with new products you're using.

You could even do this with a gmail account and custom rules, which is what I currently do, but I have setup an internal inbox in the past with a simple python script to forward emails that were of interest.

Get list of passed arguments in Windows batch script (.bat)

Sometimes I need to extract several command line parameters, but not all of them and not from the first one. Let's assume the following call:

Test.bat uno dos tres cuatro cinco seis siete

Of course, the extension ".bat" is not needed at least you have test.exe in same folder. What we want is to get the output "tres cuatro cinco" (no matter if one line or three). The goal is that only I need three parameters and starting in the third one. In order to have a simple example the action for each one is just "echo", but you can think in some other more complex action over the selected parameters.

I've produced some examples, (options) in order you can see which one you consider better for you. Unfortunately, there is not a nice (or I don't know about) way based on a for loop over the range like "for %%i in (%3, 1, %5)".

@echo off 
setlocal EnableDelayedExpansion

echo Option 1: one by one (same line)
echo %3, %4, %5
echo.

echo Option 2: Loop For one by one
for %%a in (%3, %4, %5) do echo %%a
echo.

echo Option 3: Loop For with check of limits
set i=0
for %%a in (%*) do (
    set /A i=i+1
    If !i! GTR 2 if !i! LSS 6 echo %%a
)
echo.

echo Option 4: Loop For with auxiliary list
for /l %%i in (3,1,5) do  (
    set a=%%i
    set b=echo %%
    set b=!b!!a!
    call !b!
)
echo.

echo Option 5: Assigning to an array of elements previously
set e[0]=%0
set i=0 
for %%a in (%*) do (
    set /A i=i+1
    set e[!i!]=%%a
)
for  /l %%i in (3,1,5) do (
    echo !e[%%i]!
)
echo.

echo Option 6: using shift and goto loop. It doesn't work with for loop
set i=2
:loop6
    set /A i=i+1
    echo %3
    shift
    If %i% LSS 5 goto :loop6

Probably you can find more options or combine several ones. Enjoy them.

Adding Multiple Values in ArrayList at a single index

create simple method to do that for you:

public void addMulti(String[] strings,List list){
    for (int i = 0; i < strings.length; i++) {
        list.add(strings[i]);
    }
}

Then you can create

String[] wrong ={"1","2","3","4","5","6"};

and add it with this method to your list.

Array functions in jQuery

An easy way to get the max and min value in an array is as follows. This has been explained at get max & min values in array

var myarray = [5,8,2,4,11,7,3];
// Function to get the Max value in Array
Array.max = function( array ){
return Math.max.apply( Math, array );
};

// Function to get the Min value in Array
Array.min = function( array ){
return Math.min.apply( Math, array );
};
// Usage 
alert(Array.max(myarray));
alert(Array.min(myarray));

Move all files except one

This could be simpler and easy to remember and it works for me.

mv $(ls ~/folder | grep -v ~/folder/exclude.png) ~/destination

sed edit file in place

On a system where sed does not have the ability to edit files in place, I think the better solution would be to use perl:

perl -pi -e 's/foo/bar/g' file.txt

Although this does create a temporary file, it replaces the original because an empty in place suffix/extension has been supplied.

How to remove docker completely from ubuntu 14.04

Probably your problem is that for Docker that has been installed from default Ubuntu repository, the package name is docker.io

Or package name may be something like docker-ce. Try running

dpkg -l | grep -i docker

to identify what installed package you have

So you need to change package name in commands from https://stackoverflow.com/a/31313851/2340159 to match package name. For example, for docker.io it would be:

sudo apt-get purge -y docker.io
sudo apt-get autoremove -y --purge docker.io
sudo apt-get autoclean

It adds:

The above commands will not remove images, containers, volumes, or user created configuration files on your host. If you wish to delete all images, containers, and volumes run the following command:

sudo rm -rf /var/lib/docker

Remove docker from apparmor.d:

sudo rm /etc/apparmor.d/docker

Remove docker group:

sudo groupdel docker

mongodb group values by multiple fields

TLDR Summary

In modern MongoDB releases you can brute force this with $slice just off the basic aggregation result. For "large" results, run parallel queries instead for each grouping ( a demonstration listing is at the end of the answer ), or wait for SERVER-9377 to resolve, which would allow a "limit" to the number of items to $push to an array.

db.books.aggregate([
    { "$group": {
        "_id": {
            "addr": "$addr",
            "book": "$book"
        },
        "bookCount": { "$sum": 1 }
    }},
    { "$group": {
        "_id": "$_id.addr",
        "books": { 
            "$push": { 
                "book": "$_id.book",
                "count": "$bookCount"
            },
        },
        "count": { "$sum": "$bookCount" }
    }},
    { "$sort": { "count": -1 } },
    { "$limit": 2 },
    { "$project": {
        "books": { "$slice": [ "$books", 2 ] },
        "count": 1
    }}
])

MongoDB 3.6 Preview

Still not resolving SERVER-9377, but in this release $lookup allows a new "non-correlated" option which takes an "pipeline" expression as an argument instead of the "localFields" and "foreignFields" options. This then allows a "self-join" with another pipeline expression, in which we can apply $limit in order to return the "top-n" results.

db.books.aggregate([
  { "$group": {
    "_id": "$addr",
    "count": { "$sum": 1 }
  }},
  { "$sort": { "count": -1 } },
  { "$limit": 2 },
  { "$lookup": {
    "from": "books",
    "let": {
      "addr": "$_id"
    },
    "pipeline": [
      { "$match": { 
        "$expr": { "$eq": [ "$addr", "$$addr"] }
      }},
      { "$group": {
        "_id": "$book",
        "count": { "$sum": 1 }
      }},
      { "$sort": { "count": -1  } },
      { "$limit": 2 }
    ],
    "as": "books"
  }}
])

The other addition here is of course the ability to interpolate the variable through $expr using $match to select the matching items in the "join", but the general premise is a "pipeline within a pipeline" where the inner content can be filtered by matches from the parent. Since they are both "pipelines" themselves we can $limit each result separately.

This would be the next best option to running parallel queries, and actually would be better if the $match were allowed and able to use an index in the "sub-pipeline" processing. So which is does not use the "limit to $push" as the referenced issue asks, it actually delivers something that should work better.


Original Content

You seem have stumbled upon the top "N" problem. In a way your problem is fairly easy to solve though not with the exact limiting that you ask for:

db.books.aggregate([
    { "$group": {
        "_id": {
            "addr": "$addr",
            "book": "$book"
        },
        "bookCount": { "$sum": 1 }
    }},
    { "$group": {
        "_id": "$_id.addr",
        "books": { 
            "$push": { 
                "book": "$_id.book",
                "count": "$bookCount"
            },
        },
        "count": { "$sum": "$bookCount" }
    }},
    { "$sort": { "count": -1 } },
    { "$limit": 2 }
])

Now that will give you a result like this:

{
    "result" : [
            {
                    "_id" : "address1",
                    "books" : [
                            {
                                    "book" : "book4",
                                    "count" : 1
                            },
                            {
                                    "book" : "book5",
                                    "count" : 1
                            },
                            {
                                    "book" : "book1",
                                    "count" : 3
                            }
                    ],
                    "count" : 5
            },
            {
                    "_id" : "address2",
                    "books" : [
                            {
                                    "book" : "book5",
                                    "count" : 1
                            },
                            {
                                    "book" : "book1",
                                    "count" : 2
                            }
                    ],
                    "count" : 3
            }
    ],
    "ok" : 1
}

So this differs from what you are asking in that, while we do get the top results for the address values the underlying "books" selection is not limited to only a required amount of results.

This turns out to be very difficult to do, but it can be done though the complexity just increases with the number of items you need to match. To keep it simple we can keep this at 2 matches at most:

db.books.aggregate([
    { "$group": {
        "_id": {
            "addr": "$addr",
            "book": "$book"
        },
        "bookCount": { "$sum": 1 }
    }},
    { "$group": {
        "_id": "$_id.addr",
        "books": { 
            "$push": { 
                "book": "$_id.book",
                "count": "$bookCount"
            },
        },
        "count": { "$sum": "$bookCount" }
    }},
    { "$sort": { "count": -1 } },
    { "$limit": 2 },
    { "$unwind": "$books" },
    { "$sort": { "count": 1, "books.count": -1 } },
    { "$group": {
        "_id": "$_id",
        "books": { "$push": "$books" },
        "count": { "$first": "$count" }
    }},
    { "$project": {
        "_id": {
            "_id": "$_id",
            "books": "$books",
            "count": "$count"
        },
        "newBooks": "$books"
    }},
    { "$unwind": "$newBooks" },
    { "$group": {
      "_id": "$_id",
      "num1": { "$first": "$newBooks" }
    }},
    { "$project": {
        "_id": "$_id",
        "newBooks": "$_id.books",
        "num1": 1
    }},
    { "$unwind": "$newBooks" },
    { "$project": {
        "_id": "$_id",
        "num1": 1,
        "newBooks": 1,
        "seen": { "$eq": [
            "$num1",
            "$newBooks"
        ]}
    }},
    { "$match": { "seen": false } },
    { "$group":{
        "_id": "$_id._id",
        "num1": { "$first": "$num1" },
        "num2": { "$first": "$newBooks" },
        "count": { "$first": "$_id.count" }
    }},
    { "$project": {
        "num1": 1,
        "num2": 1,
        "count": 1,
        "type": { "$cond": [ 1, [true,false],0 ] }
    }},
    { "$unwind": "$type" },
    { "$project": {
        "books": { "$cond": [
            "$type",
            "$num1",
            "$num2"
        ]},
        "count": 1
    }},
    { "$group": {
        "_id": "$_id",
        "count": { "$first": "$count" },
        "books": { "$push": "$books" }
    }},
    { "$sort": { "count": -1 } }
])

So that will actually give you the top 2 "books" from the top two "address" entries.

But for my money, stay with the first form and then simply "slice" the elements of the array that are returned to take the first "N" elements.


Demonstration Code

The demonstration code is appropriate for usage with current LTS versions of NodeJS from v8.x and v10.x releases. That's mostly for the async/await syntax, but there is nothing really within the general flow that has any such restriction, and adapts with little alteration to plain promises or even back to plain callback implementation.

index.js

const { MongoClient } = require('mongodb');
const fs = require('mz/fs');

const uri = 'mongodb://localhost:27017';

const log = data => console.log(JSON.stringify(data, undefined, 2));

(async function() {

  try {
    const client = await MongoClient.connect(uri);

    const db = client.db('bookDemo');
    const books = db.collection('books');

    let { version } = await db.command({ buildInfo: 1 });
    version = parseFloat(version.match(new RegExp(/(?:(?!-).)*/))[0]);

    // Clear and load books
    await books.deleteMany({});

    await books.insertMany(
      (await fs.readFile('books.json'))
        .toString()
        .replace(/\n$/,"")
        .split("\n")
        .map(JSON.parse)
    );

    if ( version >= 3.6 ) {

    // Non-correlated pipeline with limits
      let result = await books.aggregate([
        { "$group": {
          "_id": "$addr",
          "count": { "$sum": 1 }
        }},
        { "$sort": { "count": -1 } },
        { "$limit": 2 },
        { "$lookup": {
          "from": "books",
          "as": "books",
          "let": { "addr": "$_id" },
          "pipeline": [
            { "$match": {
              "$expr": { "$eq": [ "$addr", "$$addr" ] }
            }},
            { "$group": {
              "_id": "$book",
              "count": { "$sum": 1 },
            }},
            { "$sort": { "count": -1 } },
            { "$limit": 2 }
          ]
        }}
      ]).toArray();

      log({ result });
    }

    // Serial result procesing with parallel fetch

    // First get top addr items
    let topaddr = await books.aggregate([
      { "$group": {
        "_id": "$addr",
        "count": { "$sum": 1 }
      }},
      { "$sort": { "count": -1 } },
      { "$limit": 2 }
    ]).toArray();

    // Run parallel top books for each addr
    let topbooks = await Promise.all(
      topaddr.map(({ _id: addr }) =>
        books.aggregate([
          { "$match": { addr } },
          { "$group": {
            "_id": "$book",
            "count": { "$sum": 1 }
          }},
          { "$sort": { "count": -1 } },
          { "$limit": 2 }
        ]).toArray()
      )
    );

    // Merge output
    topaddr = topaddr.map((d,i) => ({ ...d, books: topbooks[i] }));
    log({ topaddr });

    client.close();

  } catch(e) {
    console.error(e)
  } finally {
    process.exit()
  }

})()

books.json

{ "addr": "address1",  "book": "book1"  }
{ "addr": "address2",  "book": "book1"  }
{ "addr": "address1",  "book": "book5"  }
{ "addr": "address3",  "book": "book9"  }
{ "addr": "address2",  "book": "book5"  }
{ "addr": "address2",  "book": "book1"  }
{ "addr": "address1",  "book": "book1"  }
{ "addr": "address15", "book": "book1"  }
{ "addr": "address9",  "book": "book99" }
{ "addr": "address90", "book": "book33" }
{ "addr": "address4",  "book": "book3"  }
{ "addr": "address5",  "book": "book1"  }
{ "addr": "address77", "book": "book11" }
{ "addr": "address1",  "book": "book1"  }

Twitter API returns error 215, Bad Authentication Data

I'm using HybridAuth and was running into this error connecting to Twitter. I tracked it down to (me) sending Twitter an incorrectly cased request type (get/post instead of GET/POST).

This would cause a 215:

$call = '/search/tweets.json';
$call_type = 'get';
$call_args = array(
    'q'           => 'pancakes',
    'count'       => 5,
);
$response = $provider_api->api( $call, $call_type, $call_args );

This would not:

$call = '/search/tweets.json';
$call_type = 'GET';
$call_args = array(
    'q'           => 'pancakes',
    'count'       => 5,
);
$response = $provider_api->api( $call, $call_type, $call_args );

Side note: In the case of HybridAuth the following also would not (because HA internally provides the correctly-cased value for the request type):

$call = '/search/tweets.json';
$call_args = array(
    'q'           => 'pancakes',
    'count'       => 5,
);
$response = $providers['Twitter']->get( $call, $call_args );

Testing javascript with Mocha - how can I use console.log to debug a test?

I had an issue with node.exe programs like test output with mocha.

In my case, I solved it by removing some default "node.exe" alias.

I'm using Git Bash for Windows(2.29.2) and some default aliases are set from /etc/profile.d/aliases.sh,

  # show me alias related to 'node'
  $ alias|grep node
  alias node='winpty node.exe'`

To remove the alias, update aliases.sh or simply do

unalias node

I don't know why winpty has this side effect on console.info buffered output but with a direct node.exe use, I've no more stdout issue.

Java escape JSON String?

org.json.simple.JSONObject.escape() escapes quotes,, /, \r, \n, \b, \f, \t and other control characters.

import org.json.simple.JSONValue;
JSONValue.escape("test string");

Add pom.xml when using maven

<dependency>
    <groupId>com.googlecode.json-simple</groupId>
    <artifactId>json-simple</artifactId>
    <scope>test</scope>
</dependency>

How do I provide a username and password when running "git clone [email protected]"?

Though there are many answers, myself facing the repeated issue when username or password has special characters in it.

URL encode your username and password for git, then use it as part of URL itself (when there is no security concern).

Say, URL encoded value of username

'user+1' is user%2B1

and URL encoded value of password

'Welcome@1234' is Welcome%401234

Then your GIT Clone URL would look like,

git clone https://user%2B1:Welcome%401234@actual-git-url-for-the-repo works perfectly, whereas,

git clone https://user+1:Welcome@1234@actual-git-url-for-the-repo gives you 403 errors

Hope this helps.

Just in case, want to URL encode online: https://www.urlencoder.org/

VB6 IDE cannot load MSCOMCTL.OCX after update KB 2687323

The problem has been resolved by running the following in elevated command prompt:

command :

cd C:\Windows\System32\
regtlib msdatsrc.tlb

or

cd C:\Windows\SysWOW64\
regtlib msdatsrc.tlb

I hope this helps.

Understanding generators in Python

Generators could be thought of as shorthand for creating an iterator. They behave like a Java Iterator. Example:

>>> g = (x for x in range(10))
>>> g
<generator object <genexpr> at 0x7fac1c1e6aa0>
>>> g.next()
0
>>> g.next()
1
>>> g.next()
2
>>> list(g)   # force iterating the rest
[3, 4, 5, 6, 7, 8, 9]
>>> g.next()  # iterator is at the end; calling next again will throw
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
StopIteration

Hope this helps/is what you are looking for.

Update:

As many other answers are showing, there are different ways to create a generator. You can use the parentheses syntax as in my example above, or you can use yield. Another interesting feature is that generators can be "infinite" -- iterators that don't stop:

>>> def infinite_gen():
...     n = 0
...     while True:
...         yield n
...         n = n + 1
... 
>>> g = infinite_gen()
>>> g.next()
0
>>> g.next()
1
>>> g.next()
2
>>> g.next()
3
...

Alternate table row color using CSS?

can i write my html like this with use css ?

Yes you can but then you will have to use the :nth-child() pseudo selector (which has limited support though):

table.alternate_color tr:nth-child(odd) td{
   /* styles here */
}
table.alternate_color tr:nth-child(even) td{
   /* styles here */
}

Query for documents where array size is greater than 1

db.accommodations.find({"name":{"$exists":true, "$ne":[], "$not":{"$size":1}}})

How can I use async/await at the top level?

Node -
You can run node --experimental-repl-await while in the REPL. I'm not so sure about scripting.

Deno -
Deno already has it built in.

How to confirm RedHat Enterprise Linux version?

That is the release version of RHEL, or at least the release of RHEL from which the package supplying /etc/redhat-release was installed. A file like that is probably the closest you can come; you could also look at /etc/lsb-release.

It is theoretically possible to have packages installed from a mix of versions (e.g. upgrading part of the system to 5.5 while leaving other parts at 5.4), so if you depend on the versions of specific components you will need to check for those individually.

How to disable RecyclerView scrolling?

This a bit hackish workaround but it works; you can enable/disable scrolling in the RecyclerView.

This is an empty RecyclerView.OnItemTouchListener stealing every touch event thus disabling the target RecyclerView.

public class RecyclerViewDisabler implements RecyclerView.OnItemTouchListener {

    @Override
    public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
        return true;
    }

    @Override
    public void onTouchEvent(RecyclerView rv, MotionEvent e) {

    }

    @Override
    public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {

    }
}

Using it:

RecyclerView rv = ...
RecyclerView.OnItemTouchListener disabler = new RecyclerViewDisabler();

rv.addOnItemTouchListener(disabler);        // disables scolling
// do stuff while scrolling is disabled
rv.removeOnItemTouchListener(disabler);     // scrolling is enabled again 

How to overwrite existing files in batch?

You can refer Windows command prompt help using following command : xcopy /?

Maximum Length of Command Line String

In Windows 10, it's still 8191 characters...at least on my machine.

It just cuts off any text after 8191 characters. Well, actually, I got 8196 characters, and after 8196, then it just won't let me type any more.

Here's a script that will test how long of a statement you can use. Well, assuming you have gawk/awk installed.

echo rem this is a test of how long of a line that a .cmd script can generate >testbat.bat
gawk 'BEGIN {printf "echo -----";for (i=10;i^<=100000;i +=10) printf "%%06d----",i;print;print "pause";}' >>testbat.bat
testbat.bat

Difference between onStart() and onResume()

The book "Hello, Android, Introducing Google's Mobile Development Platform" gives a nice explanation of the life cycle of android apps. Luckily they have the particular chapter online as an excerpt. See the graphic on page 39 in http://media.pragprog.com/titles/eband3/concepts.pdf

By the way, this book is highly recommendable for android beginners!

programming a servo thru a barometer

You could define a mapping of air pressure to servo angle, for example:

def calc_angle(pressure, min_p=1000, max_p=1200):     return 360 * ((pressure - min_p) / float(max_p - min_p))  angle = calc_angle(pressure) 

This will linearly convert pressure values between min_p and max_p to angles between 0 and 360 (you could include min_a and max_a to constrain the angle, too).

To pick a data structure, I wouldn't use a list but you could look up values in a dictionary:

d = {1000:0, 1001: 1.8, ...}  angle = d[pressure] 

but this would be rather time-consuming to type out!

Executing multiple SQL queries in one statement with PHP

With mysqli you're able to use multiple statements for real using mysqli_multi_query().

Read more on multiple statements in the PHP Docs.

SELECT inside a COUNT

Use SELECT COUNT(*) FROM t WHERE a = current_a AND c = 'const' ) as d.

How can I pass parameters to a partial view in mvc 4

One of The Shortest method i found for single value while i was searching for myself, is just passing single string and setting string as model in view like this.

In your Partial calling side

@Html.Partial("ParitalAction", "String data to pass to partial")

And then binding the model with Partial View like this

@model string

and the using its value in Partial View like this

@Model

You can also play with other datatypes like array, int or more complex data types like IDictionary or something else.

Hope it helps,

C split a char array into different variables

I came up with this.This seems to work best for me.It converts a string of number and splits it into array of integer:

void splitInput(int arr[], int sizeArr, char num[])
{
    for(int i = 0; i < sizeArr; i++)
        // We are subtracting 48 because the numbers in ASCII starts at 48.
        arr[i] = (int)num[i] - 48;
}

How to part DATE and TIME from DATETIME in MySQL

For only date use
date("Y-m-d");

and for only time use
date("H:i:s");

Recursion in Python? RuntimeError: maximum recursion depth exceeded while calling a Python object

That's the error you get when a function makes too many recursive calls to itself. It might be doing this because the base case is never met (and therefore it gets stuck in an infinite loop) or just by making an large number of calls to itself. You could replace the recursive calls with while loops.

How can I use Oracle SQL developer to run stored procedures?

I am not sure how to see the actual rows/records that come back.

Stored procedures do not return records. They may have a cursor as an output parameter, which is a pointer to a select statement. But it requires additional action to actually bring back rows from that cursor.

In SQL Developer, you can execute a procedure that returns a ref cursor as follows

var rc refcursor
exec proc_name(:rc)

After that, if you execute the following, it will show the results from the cursor:

print rc

How do I restart a service on a remote machine in Windows?

I would suggest you to have a look at RSHD

You do not need to bother for a client, Windows has it by default.

Stash just a single file

I think stash -p is probably the choice you want, but just in case you run into other even more tricky things in the future, remember that:

Stash is really just a very simple alternative to the only slightly more complex branch sets. Stash is very useful for moving things around quickly, but you can accomplish more complex things with branches without that much more headache and work.

# git checkout -b tmpbranch
# git add the_file
# git commit -m "stashing the_file"
# git checkout master

go about and do what you want, and then later simply rebase and/or merge the tmpbranch. It really isn't that much extra work when you need to do more careful tracking than stash will allow.

BACKUP LOG cannot be performed because there is no current database backup

I just deleted the existing DB that i wanted to override with the backup and restored it from backup and it worked without the error.

Fade In on Scroll Down, Fade Out on Scroll Up - based on element position in window

Sorry this is and old thread but some people would still need this I guess,

Note: I achieved this using Animate.css library for animating the fade.

I used your code and just added .hidden class (using bootstrap's hidden class) but you can still just define .hidden { opacity: 0; }

$(document).ready(function() {

/* Every time the window is scrolled ... */

$(window).scroll( function(){

/* Check the location of each desired element */
$('.hideme').each( function(i){

    var bottom_of_object = $(this).position().top + $(this).outerHeight();
    var bottom_of_window = $(window).scrollTop() + $(window).height();


    /* If the object is completely visible in the window, fade it it */
    if( bottom_of_window > bottom_of_object ){

        $(this).removeClass('hidden');
        $(this).addClass('animated fadeInUp');
    }    else {
            $(this).addClass('hidden');
               }

}); 
}); 
});

Another Note: Applying this to containers might cause it to be glitchy.

Get length of array?

Length of an array:

UBound(columns)-LBound(columns)+1

UBound alone is not the best method for getting the length of every array as arrays in VBA can start at different indexes, e.g Dim arr(2 to 10)

UBound will return correct results only if the array is 1-based (starts indexing at 1 e.g. Dim arr(1 to 10). It will return wrong results in any other circumstance e.g. Dim arr(10)

More on the VBA Array in this VBA Array tutorial.

Java naming convention for static final variables

Don't live fanatically with the conventions that SUN have med up, do whats feel right to you and your team.

For example this is how eclipse do it, breaking the convention. Try adding implements Serializable and eclipse will ask to generate this line for you.

Update: There were special cases that was excluded didn't know that. I however withholds to do what you and your team seems fit.

Disable scrolling on `<input type=number>`

Most answers blur the number element even if the cursor isn't hovering over it; the below does not

document.addEventListener("wheel", function(event) {
  if (document.activeElement.type === "number" &&
    document.elementFromPoint(event.x, event.y) == document.activeElement) {
    document.activeElement.blur();
  }
});

https://jsfiddle.net/s06puv3j/1/

Angular.js and HTML5 date input value -- how to get Firefox to show a readable date value in a date input?

You can use this, it works fine:

<input type="date" class="form1"  
  value="{{date | date:MM/dd/yyyy}}"
  ng-model="date" 
  name="id" 
  validatedateformat 
  data-date-format="mm/dd/yyyy"
  maxlength="10" 
  id="id" 
  calendar 
  maxdate="todays"
  ng-click="openCalendar('id')">
    <span class="input-group-addon">
      <span class="glyphicon glyphicon-calendar" ng-click="openCalendar('id')"></span>
    </span>
</input>

How can I view live MySQL queries?

I've been looking to do the same, and have cobbled together a solution from various posts, plus created a small console app to output the live query text as it's written to the log file. This was important in my case as I'm using Entity Framework with MySQL and I need to be able to inspect the generated SQL.

Steps to create the log file (some duplication of other posts, all here for simplicity):

  1. Edit the file located at:

    C:\Program Files (x86)\MySQL\MySQL Server 5.5\my.ini
    

    Add "log=development.log" to the bottom of the file. (Note saving this file required me to run my text editor as an admin).

  2. Use MySql workbench to open a command line, enter the password.

    Run the following to turn on general logging which will record all queries ran:

    SET GLOBAL general_log = 'ON';
    
    To turn off:
    
    SET GLOBAL general_log = 'OFF';
    

    This will cause running queries to be written to a text file at the following location.

    C:\ProgramData\MySQL\MySQL Server 5.5\data\development.log
    
  3. Create / Run a console app that will output the log information in real time:

    Source available to download here

    Source:

    using System;
    using System.Configuration;
    using System.IO;
    using System.Threading;
    
    namespace LiveLogs.ConsoleApp
    {
      class Program
      {
        static void Main(string[] args)
        {
            // Console sizing can cause exceptions if you are using a 
            // small monitor. Change as required.
    
            Console.SetWindowSize(152, 58);
            Console.BufferHeight = 1500;
    
            string filePath = ConfigurationManager.AppSettings["MonitoredTextFilePath"];
    
            Console.Title = string.Format("Live Logs {0}", filePath);
    
            var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);
    
            // Move to the end of the stream so we do not read in existing
            // log text, only watch for new text.
    
            fileStream.Position = fileStream.Length;
    
            StreamReader streamReader;
    
            // Commented lines are for duplicating the log output as it's written to 
            // allow verification via a diff that the contents are the same and all 
            // is being output.
    
            // var fsWrite = new FileStream(@"C:\DuplicateFile.txt", FileMode.Create);
            // var sw = new StreamWriter(fsWrite);
    
            int rowNum = 0;
    
            while (true)
            {
                streamReader = new StreamReader(fileStream);
    
                string line;
                string rowStr;
    
                while (streamReader.Peek() != -1)
                {
                    rowNum++;
    
                    line = streamReader.ReadLine();
                    rowStr = rowNum.ToString();
    
                    string output = String.Format("{0} {1}:\t{2}", rowStr.PadLeft(6, '0'), DateTime.Now.ToLongTimeString(), line);
    
                    Console.WriteLine(output);
    
                    // sw.WriteLine(output);
                }
    
                // sw.Flush();
    
                Thread.Sleep(500);
            }
        }
      }
    }
    

Javascript get the text value of a column from a particular row of an html table

in case if your table has tbody

let tbl = document.getElementById("tbl").getElementsByTagName('tbody')[0];
console.log(tbl.rows[0].cells[0].innerHTML)

How to represent e^(-t^2) in MATLAB?

If t is a matrix, you need to use the element-wise multiplication or exponentiation. Note the dot.

x = exp( -t.^2 )

or

x = exp( -t.*t )

Add marker to Google Map on Click

After much further research, i managed to find a solution.

google.maps.event.addListener(map, 'click', function(event) {
   placeMarker(event.latLng);
});

function placeMarker(location) {
    var marker = new google.maps.Marker({
        position: location, 
        map: map
    });
}

Maximum execution time in phpMyadmin

I faced the same problem while executing a curl. I got it right when I changed the following in the php.ini file:

max_execution_time = 1000 ;

and also

max_input_time = 1000 ;

Probably your problem should be solved by making above two changes and restarting the apache server.

Even after changing the above the problem persists and if you think it's because of some database operation using mysql you can try changing this also:

mysql.connect_timeout = 1000 ; // this is not neccessary

All this should be changed in php.ini file and apache server should be restarted to see the changes.

How to convert string to datetime format in pandas python?

Use to_datetime, there is no need for a format string the parser is man/woman enough to handle it:

In [51]:
pd.to_datetime(df['I_DATE'])

Out[51]:
0   2012-03-28 14:15:00
1   2012-03-28 14:17:28
2   2012-03-28 14:50:50
Name: I_DATE, dtype: datetime64[ns]

To access the date/day/time component use the dt accessor:

In [54]:
df['I_DATE'].dt.date

Out[54]:
0    2012-03-28
1    2012-03-28
2    2012-03-28
dtype: object

In [56]:    
df['I_DATE'].dt.time

Out[56]:
0    14:15:00
1    14:17:28
2    14:50:50
dtype: object

You can use strings to filter as an example:

In [59]:
df = pd.DataFrame({'date':pd.date_range(start = dt.datetime(2015,1,1), end = dt.datetime.now())})
df[(df['date'] > '2015-02-04') & (df['date'] < '2015-02-10')]

Out[59]:
         date
35 2015-02-05
36 2015-02-06
37 2015-02-07
38 2015-02-08
39 2015-02-09

How do I get ruby to print a full backtrace instead of a truncated one?

One liner for callstack:

begin; Whatever.you.want; rescue => e; puts e.message; puts; puts e.backtrace; end

One liner for callstack without all the gems's:

begin; Whatever.you.want; rescue => e; puts e.message; puts; puts e.backtrace.grep_v(/\/gems\//); end

One liner for callstack without all the gems's and relative to current directory

begin; Whatever.you.want; rescue => e; puts e.message; puts; puts e.backtrace.grep_v(/\/gems\//).map { |l| l.gsub(`pwd`.strip + '/', '') }; end

Add one day to date in javascript

If you don't mind using a library, DateJS (https://github.com/abritinthebay/datejs/) would make this fairly easy. You would probably be better off with one of the answers using vanilla JavaScript however, unless you're going to take advantage of some other DateJS features like parsing of unusually-formatted dates.

If you're using DateJS a line like this should do the trick:

Date.parse(startdate).add(1).days();

You could also use MomentJS which has similar features (http://momentjs.com/), however I'm not as familiar with it.

Getting error: Peer authentication failed for user "postgres", when trying to get pgsql working with rails

You need just set METHOD to trust.

#TYPE  DATABASE        USER            ADDRESS                 METHOD
local    all             all                                     trust

And reload postgres server.

# service postgresql-9.5 reload

Changes in pg_hba.conf dont require RESTART postgres server. just RELOAD.

How to adjust an UIButton's imageSize?

you can use imageEdgeInsets property The inset or outset margins for the rectangle around the button’s image.

 [self.btn setImageEdgeInsets:UIEdgeInsetsMake(6, 6, 6, 6)];

A positive value shrinks, or insets, that edge—moving. A negative value expands, or outsets, that edge.