Programs & Examples On #Multi user

Setting up an MS-Access DB for multi-user access

I have found the SMB2 protocol introduced in Vista to lock the access databases. It can be disabled by the following regedit:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\LanmanServer\Parameters] "Smb2"=dword:00000000

Remove local git tags that are no longer on the remote repository

Show the difference between local and remote tags:

diff <(git tag | sort) <( git ls-remote --tags origin | cut -f2 | grep -v '\^' | sed 's#refs/tags/##' | sort)
  • git tag gives the list of local tags
  • git ls-remote --tags gives the list of full paths to remote tags
  • cut -f2 | grep -v '\^' | sed 's#refs/tags/##' parses out just the tag name from list of remote tag paths
  • Finally we sort each of the two lists and diff them

The lines starting with "< " are your local tags that are no longer in the remote repo. If they are few, you can remove them manually one by one, if they are many, you do more grep-ing and piping to automate it.

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

I encountered the same problem on windows 10. My very specific issue is due to my installation of Anaconda. I installed Anaconda and under the path Path/to/Anaconda3/, there comes the python.exe. Thus, I didn't install python at all because Anaconda includes python. When using pip to install packages, I found the same error report, pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available..

The solution was the following:

1) you can download python again on the official website;

2) Navigate to the directory where "Python 3.7 (64-bit).lnk"is located

3) import ssl and exit()

4) type in cmd, "Python 3.7 (64-bit).lnk" -m pip install tensorflow for instance.

Here, you're all set.

T-SQL: Export to new Excel file

Use PowerShell:

$Server = "TestServer"
$Database = "TestDatabase"
$Query = "select * from TestTable"
$FilePath = "C:\OutputFile.csv"

# This will overwrite the file if it already exists.
Invoke-Sqlcmd -Query $Query -Database $Database -ServerInstance $Server | Export-Csv $FilePath

In my usual cases, all I really need is a CSV file that can be read by Excel. However, if you need an actual Excel file, then tack on some code to convert the CSV file to an Excel file. This answer gives a solution for this, but I've not tested it.

optional parameters in SQL Server stored proc?

2014 and above at least you can set a default and it will take that and NOT error when you do not pass that parameter. Partial Example: the 3rd parameter is added as optional. exec of the actual procedure with only the first two parameters worked fine

exec getlist 47,1,0

create procedure getlist
   @convId int,
   @SortOrder int,
   @contestantsOnly bit = 0
as

how to cancel/abort ajax request in axios

https://github.com/axios/axios#cancellation

const CancelToken = axios.CancelToken;
                const source = CancelToken.source();
                let url = 'www.url.com'


                axios.get(url, {
                    progress: false,
                    cancelToken: source.token
                })
                    .then(resp => {

                        alert('done')

                    })

                setTimeout(() => {
                    source.cancel('Operation canceled by the user.');
                },'1000')

How can I check if an argument is defined when starting/calling a batch file?

IF "%1"=="" GOTO :Continue
.....
.....
:Continue
IF "%1"=="" echo No Parameter given

XPath - Difference between node() and text()

text() and node() are node tests, in XPath terminology (compare).

Node tests operate on a set (on an axis, to be exact) of nodes and return the ones that are of a certain type. When no axis is mentioned, the child axis is assumed by default.

There are all kinds of node tests:

  • node() matches any node (the least specific node test of them all)
  • text() matches text nodes only
  • comment() matches comment nodes
  • * matches any element node
  • foo matches any element node named "foo"
  • processing-instruction() matches PI nodes (they look like <?name value?>).
  • Side note: The * also matches attribute nodes, but only along the attribute axis. @* is a shorthand for attribute::*. Attributes are not part of the child axis, that's why a normal * does not select them.

This XML document:

<produce>
    <item>apple</item>
    <item>banana</item>
    <item>pepper</item>
</produce>

represents the following DOM (simplified):

root node
   element node (name="produce")
      text node (value="\n    ")
      element node (name="item")
         text node (value="apple")
      text node (value="\n    ")
      element node (name="item")
         text node (value="banana")
      text node (value="\n    ")
      element node (name="item")
         text node (value="pepper")
      text node (value="\n")

So with XPath:

  • / selects the root node
  • /produce selects a child element of the root node if it has the name "produce" (This is called the document element; it represents the document itself. Document element and root node are often confused, but they are not the same thing.)
  • /produce/node() selects any type of child node beneath /produce/ (i.e. all 7 children)
  • /produce/text() selects the 4 (!) whitespace-only text nodes
  • /produce/item[1] selects the first child element named "item"
  • /produce/item[1]/text() selects all child text nodes (there's only one - "apple" - in this case)

And so on.

So, your questions

  • "Select the text of all items under produce" /produce/item/text() (3 nodes selected)
  • "Select all the manager nodes in all departments" //department/manager (1 node selected)

Notes

  • The default axis in XPath is the child axis. You can change the axis by prefixing a different axis name. For example: //item/ancestor::produce
  • Element nodes have text values. When you evaluate an element node, its textual contents will be returned. In case of this example, /produce/item[1]/text() and string(/produce/item[1]) will be the same.
  • Also see this answer where I outline the individual parts of an XPath expression graphically.

'sprintf': double precision in C

You need to write it like sprintf(aa, "%9.7lf", a)

Check out http://en.wikipedia.org/wiki/Printf for some more details on format codes.

Null pointer Exception on .setOnClickListener

android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference

Because Submit button is inside login_modal so you need to use loginDialog view to access button:

Submit = (Button)loginDialog.findViewById(R.id.Submit);

CMake error at CMakeLists.txt:30 (project): No CMAKE_C_COMPILER could be found

I had the same errors with CMake. In my case, I have used the wrong Visual Studio version in the initial CMake dialog where we have to select the Visual Studio compiler.

Then I changed it to "Visual Studio 11 2012" and things worked. (I have Visual Studio Ultimate 2012 version on my PC). In general, try to input an older version of Visual Studio version in the initial CMake configuration dialog.

Referring to a Column Alias in a WHERE Clause

SELECT
   logcount, logUserID, maxlogtm,
   DATEDIFF(day, maxlogtm, GETDATE()) AS daysdiff
FROM statslogsummary
WHERE ( DATEDIFF(day, maxlogtm, GETDATE() > 120)

Normally you can't refer to field aliases in the WHERE clause. (Think of it as the entire SELECT including aliases, is applied after the WHERE clause.)

But, as mentioned in other answers, you can force SQL to treat SELECT to be handled before the WHERE clause. This is usually done with parenthesis to force logical order of operation or with a Common Table Expression (CTE):

Parenthesis/Subselect:

SELECT
   *
FROM
(
   SELECT
      logcount, logUserID, maxlogtm,
      DATEDIFF(day, maxlogtm, GETDATE()) AS daysdiff
   FROM statslogsummary   
) as innerTable
WHERE daysdiff > 120

Or see Adam's answer for a CTE version of the same.

Convert an enum to List<string>

Use Enum's static method, GetNames. It returns a string[], like so:

Enum.GetNames(typeof(DataSourceTypes))

If you want to create a method that does only this for only one type of enum, and also converts that array to a List, you can write something like this:

public List<string> GetDataSourceTypes()
{
    return Enum.GetNames(typeof(DataSourceTypes)).ToList();
}

You will need Using System.Linq; at the top of your class to use .ToList()

How to expand and compute log(a + b)?

In general, one doesn't expand out log(a + b); you just deal with it as is. That said, there are occasionally circumstances where it makes sense to use the following identity:

log(a + b) = log(a * (1 + b/a)) = log a + log(1 + b/a)

(In fact, this identity is often used when implementing log in math libraries).

Viewing root access files/folders of android on windows

Obviously, you'll need a rooted android device. Then set up an FTP server and transfer the files.

Laravel 4 Eloquent Query Using WHERE with OR AND OR?

Incase you're looping the OR conditions, you don't need the the second $query->where from the other posts (actually I don't think you need in general, you can just use orWhere in the nested where if easier)

$attributes = ['first'=>'a','second'=>'b'];

$query->where(function ($query) use ($attributes) 
{
    foreach ($attributes as $key=>value)
    {
        //you can use orWhere the first time, doesn't need to be ->where
        $query->orWhere($key,$value);
    }
});

What is "Signal 15 received"

This indicates the linux has delivered a SIGTERM to your process. This is usually at the request of some other process (via kill()) but could also be sent by your process to itself (using raise()). This signal requests an orderly shutdown of your process.

If you need a quick cheatsheet of signal numbers, open a bash shell and:

$ kill -l
 1) SIGHUP   2) SIGINT   3) SIGQUIT  4) SIGILL
 5) SIGTRAP  6) SIGABRT  7) SIGBUS   8) SIGFPE
 9) SIGKILL 10) SIGUSR1 11) SIGSEGV 12) SIGUSR2
13) SIGPIPE 14) SIGALRM 15) SIGTERM 16) SIGSTKFLT
17) SIGCHLD 18) SIGCONT 19) SIGSTOP 20) SIGTSTP
21) SIGTTIN 22) SIGTTOU 23) SIGURG  24) SIGXCPU
25) SIGXFSZ 26) SIGVTALRM   27) SIGPROF 28) SIGWINCH
29) SIGIO   30) SIGPWR  31) SIGSYS  34) SIGRTMIN
35) SIGRTMIN+1  36) SIGRTMIN+2  37) SIGRTMIN+3  38) SIGRTMIN+4
39) SIGRTMIN+5  40) SIGRTMIN+6  41) SIGRTMIN+7  42) SIGRTMIN+8
43) SIGRTMIN+9  44) SIGRTMIN+10 45) SIGRTMIN+11 46) SIGRTMIN+12
47) SIGRTMIN+13 48) SIGRTMIN+14 49) SIGRTMIN+15 50) SIGRTMAX-14
51) SIGRTMAX-13 52) SIGRTMAX-12 53) SIGRTMAX-11 54) SIGRTMAX-10
55) SIGRTMAX-9  56) SIGRTMAX-8  57) SIGRTMAX-7  58) SIGRTMAX-6
59) SIGRTMAX-5  60) SIGRTMAX-4  61) SIGRTMAX-3  62) SIGRTMAX-2
63) SIGRTMAX-1  64) SIGRTMAX    

You can determine the sender by using an appropriate signal handler like:

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

void sigterm_handler(int signal, siginfo_t *info, void *_unused)
{
  fprintf(stderr, "Received SIGTERM from process with pid = %u\n",
      info->si_pid);
  exit(0);
}

int main (void)
{
  struct sigaction action = {
    .sa_handler = NULL,
    .sa_sigaction = sigterm_handler,
    .sa_mask = 0,
    .sa_flags = SA_SIGINFO,
    .sa_restorer = NULL
  };

  sigaction(SIGTERM, &action, NULL);
  sleep(60);

  return 0;
}

Notice that the signal handler also includes a call to exit(). It's also possible for your program to continue to execute by ignoring the signal, but this isn't recommended in general (if it's a user doing it there's a good chance it will be followed by a SIGKILL if your process doesn't exit, and you lost your opportunity to do any cleanup then).

Angular 2 / 4 / 5 - Set base href dynamically

Here's what we ended up doing.

Add this to index.html. It should be the first thing in the <head> section

<base href="/">
<script>
  (function() {
    window['_app_base'] = '/' + window.location.pathname.split('/')[1];
  })();
</script>

Then in the app.module.ts file, add { provide: APP_BASE_HREF, useValue: window['_app_base'] || '/' } to the list of providers, like so:

import { NgModule, enableProdMode, provide } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { APP_BASE_HREF, Location } from '@angular/common';


import { AppComponent, routing, appRoutingProviders, environment } from './';

if (environment.production) {
  enableProdMode();
}

@NgModule({
  declarations: [AppComponent],
  imports: [
    BrowserModule,
    HttpModule,
    routing],
  bootstrap: [AppComponent],
  providers: [
    appRoutingProviders,
    { provide: APP_BASE_HREF, useValue: window['_app_base'] || '/' },
  ]
})
export class AppModule { }

Calling Scalar-valued Functions in SQL

Make sure you have the correct database selected. You may have the master database selected if you are trying to run it in a new query window.

How should I copy Strings in Java?

Your second version is less efficient because it creates an extra string object when there is simply no need to do so.

Immutability means that your first version behaves the way you expect and is thus the approach to be preferred.

Changing width property of a :before css selector using JQuery

Pseudo elements are part of the shadow DOM and can not be modified (but can have their values queried).

However, sometimes you can get around that by using classes, for example.

jQuery

$('#element').addClass('some-class');

CSS

.some-class:before {
    /* change your properties here */
}

This may not be suitable for your query, but it does demonstrate you can achieve this pattern sometimes.

To get a pseudo element's value, try some code like...

var pseudoElementContent = window.getComputedStyle($('#element')[0], ':before')
  .getPropertyValue('content')

Why is it string.join(list) instead of list.join(string)?

Primarily because the result of a someString.join() is a string.

The sequence (list or tuple or whatever) doesn't appear in the result, just a string. Because the result is a string, it makes sense as a method of a string.

How to convert number to words in java

I tried to make the code more readable. This works for numbers within integer range

import java.util.HashMap;
import java.util.LinkedList;
import java.util.Map;
import java.util.Scanner;

public class Solution2 {

    static Map<Integer, String> numberMap = new HashMap<Integer, String>();
    static Map<Integer, String> tensMap = new HashMap<Integer, String>();
    static Map<Integer, String> exponentsMap = new HashMap<Integer, String>();
    
    public static void main(String[] args) {

        LinkedList<String> wordList = new LinkedList<String>();
        Scanner scan = new Scanner(System.in);
        int input = scan.nextInt();
        scan.close();

        exponentsMap.put(3, "thousand");
        exponentsMap.put(6, "million");
        exponentsMap.put(9, "billion");

        tensMap.put(2, "twenty");
        tensMap.put(3, "thirty");
        tensMap.put(4, "forty");
        tensMap.put(5, "fifty");
        tensMap.put(6, "sixty");
        tensMap.put(7, "seventy");
        tensMap.put(8, "eighty");
        tensMap.put(9, "ninety");

        numberMap.put(1, "one");
        numberMap.put(2, "two");
        numberMap.put(3, "three");
        numberMap.put(4, "four");
        numberMap.put(5, "five");
        numberMap.put(6, "six");
        numberMap.put(7, "seven");
        numberMap.put(8, "eight");
        numberMap.put(9, "nine");
        numberMap.put(10, "ten");
        numberMap.put(11, "eleven");
        numberMap.put(12, "twelve");
        numberMap.put(13, "thirteen");
        numberMap.put(14, "fourteen");
        numberMap.put(15, "fifteen");
        numberMap.put(16, "sixteen");
        numberMap.put(17, "seventeen");
        numberMap.put(18, "eighteen");
        numberMap.put(19, "nineteen");

        int temp = input;
        
        int exponentCounter =0;
        while(temp>0) {
            // words from 1 to 99
            addLastTwo(temp%100,wordList);
            temp=temp/100;
            
            // add hundreds before exponents
            if(temp!=0) {
                wordList.addFirst("hundred");
                wordList.addFirst(numberMap.getOrDefault(temp%10,""));
                temp = temp/10;
            }
            
            // words for exponents
            if(temp!=0) {
                exponentCounter+=3;
                wordList.addFirst(exponentsMap.getOrDefault(exponentCounter,""));
            }
        }
        wordList.stream().filter(word -> !word.contentEquals("")).forEach(word -> System.out.print(word + " "));
    }

    private static void addLastTwo(int num, LinkedList<String> wordList) {
        if (num > 19) {
            wordList.addFirst(numberMap.getOrDefault(num % 10,""));
            wordList.addFirst(tensMap.getOrDefault(num / 10,""));
            
        } else {
            wordList.addFirst(numberMap.getOrDefault(num,""));
        }
    }
}

Why is using the JavaScript eval function a bad idea?

Unless you are 100% sure that the code being evaluated is from a trusted source (usually your own application) then it's a surefire way of exposing your system to a cross-site scripting attack.

Is it possible to indent JavaScript code in Notepad++?

Try the notepad++ plugin JSMinNpp(Changed name to JSTool since 1.15)

http://www.sunjw.us/jsminnpp/

Pseudo-terminal will not be allocated because stdin is not a terminal

I'm adding this answer because it solved a related problem that I was having with the same error message.

Problem: I had installed cygwin under Windows and was getting this error: Pseudo-terminal will not be allocated because stdin is not a terminal

Resolution: It turns out that I had not installed the openssh client program and utilities. Because of that cygwin was using the Windows implementation of ssh, not the cygwin version. The solution was to install the openssh cygwin package.

How to prevent colliders from passing through each other?

Try setting the models to environment and static. That fix my issue.

Better way to check if a Path is a File or a Directory?

This was the best I could come up with given the behavior of the Exists and Attributes properties:

using System.IO;

public static class FileSystemInfoExtensions
{
    /// <summary>
    /// Checks whether a FileInfo or DirectoryInfo object is a directory, or intended to be a directory.
    /// </summary>
    /// <param name="fileSystemInfo"></param>
    /// <returns></returns>
    public static bool IsDirectory(this FileSystemInfo fileSystemInfo)
    {
        if (fileSystemInfo == null)
        {
            return false;
        }

        if ((int)fileSystemInfo.Attributes != -1)
        {
            // if attributes are initialized check the directory flag
            return fileSystemInfo.Attributes.HasFlag(FileAttributes.Directory);
        }

        // If we get here the file probably doesn't exist yet.  The best we can do is 
        // try to judge intent.  Because directories can have extensions and files
        // can lack them, we can't rely on filename.
        // 
        // We can reasonably assume that if the path doesn't exist yet and 
        // FileSystemInfo is a DirectoryInfo, a directory is intended.  FileInfo can 
        // make a directory, but it would be a bizarre code path.

        return fileSystemInfo is DirectoryInfo;
    }
}

Here's how it tests out:

    [TestMethod]
    public void IsDirectoryTest()
    {
        // non-existing file, FileAttributes not conclusive, rely on type of FileSystemInfo
        const string nonExistentFile = @"C:\TotallyFakeFile.exe";

        var nonExistentFileDirectoryInfo = new DirectoryInfo(nonExistentFile);
        Assert.IsTrue(nonExistentFileDirectoryInfo.IsDirectory());

        var nonExistentFileFileInfo = new FileInfo(nonExistentFile);
        Assert.IsFalse(nonExistentFileFileInfo.IsDirectory());

        // non-existing directory, FileAttributes not conclusive, rely on type of FileSystemInfo
        const string nonExistentDirectory = @"C:\FakeDirectory";

        var nonExistentDirectoryInfo = new DirectoryInfo(nonExistentDirectory);
        Assert.IsTrue(nonExistentDirectoryInfo.IsDirectory());

        var nonExistentFileInfo = new FileInfo(nonExistentDirectory);
        Assert.IsFalse(nonExistentFileInfo.IsDirectory());

        // Existing, rely on FileAttributes
        const string existingDirectory = @"C:\Windows";

        var existingDirectoryInfo = new DirectoryInfo(existingDirectory);
        Assert.IsTrue(existingDirectoryInfo.IsDirectory());

        var existingDirectoryFileInfo = new FileInfo(existingDirectory);
        Assert.IsTrue(existingDirectoryFileInfo.IsDirectory());

        // Existing, rely on FileAttributes
        const string existingFile = @"C:\Windows\notepad.exe";

        var existingFileDirectoryInfo = new DirectoryInfo(existingFile);
        Assert.IsFalse(existingFileDirectoryInfo.IsDirectory());

        var existingFileFileInfo = new FileInfo(existingFile);
        Assert.IsFalse(existingFileFileInfo.IsDirectory());
    }

How to delete last character in a string in C#?

paramstr.Remove((paramstr.Length-1),1);

This does work to remove a single character from the end of a string. But if I use it to remove, say, 4 characters, this doesn't work:

paramstr.Remove((paramstr.Length-4),1);

As an alternative, I have used this approach instead:

DateFrom = DateFrom.Substring(0, DateFrom.Length-4);

.NET HttpClient. How to POST string value?

You could do something like this

HttpWebRequest req = (HttpWebRequest)WebRequest.Create("http://localhost:6740/api/Membership/exist");

req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";         
req.ContentLength = 6;

StreamWriter streamOut = new StreamWriter(req.GetRequestStream(), System.Text.Encoding.ASCII);
streamOut.Write(strRequest);
streamOut.Close();
StreamReader streamIn = new StreamReader(req.GetResponse().GetResponseStream());
string strResponse = streamIn.ReadToEnd();
streamIn.Close();

And then strReponse should contain the values returned by your webservice

Sockets - How to find out what port and address I'm assigned

The comment in your code is wrong. INADDR_ANY doesn't put server's IP automatically'. It essentially puts 0.0.0.0, for the reasons explained in mark4o's answer.

Bulk load data conversion error (type mismatch or invalid character for the specified codepage) for row 1, column 4 (Year)

Try using a format file since your data file only has 4 columns. Otherwise, try OPENROWSET or use a staging table.

myTestFormatFiles.Fmt may look like:

9.0
4
1       SQLINT        0       3       ","      1     StudentNo      ""
2       SQLCHAR       0       100     ","      2     FirstName      SQL_Latin1_General_CP1_CI_AS
3       SQLCHAR       0       100     ","      3     LastName       SQL_Latin1_General_CP1_CI_AS
4       SQLINT        0       4       "\r\n"   4     Year           "


(source: microsoft.com)

This tutorial on skipping a column with BULK INSERT may also help.

Your statement then would look like:

USE xta9354
GO
BULK INSERT xta9354.dbo.Students
    FROM 'd:\userdata\xta9_Students.txt' 
    WITH (FORMATFILE = 'C:\myTestFormatFiles.Fmt')

How do I execute code AFTER a form has loaded?

I had the same problem, and solved it as follows:

Actually I want to show Message and close it automatically after 2 second. For that I had to generate (dynamically) simple form and one label showing message, stop message for 1500 ms so user read it. And Close dynamically created form. Shown event occur After load event. So code is

Form MessageForm = new Form();
MessageForm.Shown += (s, e1) => { 
    Thread t = new Thread(() => Thread.Sleep(1500)); 
    t.Start(); 
    t.Join(); 
    MessageForm.Close(); 
};

Application.WorksheetFunction.Match method

You are getting this error because the value cannot be found in the range. String or integer doesn't matter. Best thing to do in my experience is to do a check first to see if the value exists.

I used CountIf below, but there is lots of different ways to check existence of a value in a range.

Public Sub test()

Dim rng As Range
Dim aNumber As Long

aNumber = 666

Set rng = Sheet5.Range("B16:B615")

    If Application.WorksheetFunction.CountIf(rng, aNumber) > 0 Then

        rowNum = Application.WorksheetFunction.Match(aNumber, rng, 0)

    Else
        MsgBox aNumber & " does not exist in range " & rng.Address
    End If

End Sub

ALTERNATIVE WAY

Public Sub test()
    Dim rng As Range
    Dim aNumber As Variant
    Dim rowNum As Long

    aNumber = "2gg"

    Set rng = Sheet5.Range("B1:B20")

    If Not IsError(Application.Match(aNumber, rng, 0)) Then
        rowNum = Application.Match(aNumber, rng, 0)
        MsgBox rowNum
    Else
        MsgBox "error"
    End If
End Sub

OR

Public Sub test()
    Dim rng As Range
    Dim aNumber As Variant
    Dim rowNum As Variant

    aNumber = "2gg"

    Set rng = Sheet5.Range("B1:B20")

    rowNum = Application.Match(aNumber, rng, 0)

    If Not IsError(rowNum) Then
        MsgBox rowNum
    Else
        MsgBox "error"
    End If
End Sub

strdup() - what does it do in C?

strdup and strndup are defined in POSIX compliant systems as:

char *strdup(const char *str);
char *strndup(const char *str, size_t len);

The strdup() function allocates sufficient memory for a copy of the string str, does the copy, and returns a pointer to it.

The pointer may subsequently be used as an argument to the function free.

If insufficient memory is available, NULL is returned and errno is set to ENOMEM.

The strndup() function copies at most len characters from the string str always null terminating the copied string.

Saving numpy array to txt file row wise

I know this is old, but none of these answers solved the root problem of numpy not saving the array row-wise. I found that this one liner did the trick for me:

b = np.matrix(a)
np.savetxt("file", b)

Change limit for "Mysql Row size too large"

I would like to share an awesome answer, it might be helpful. Credits Bill Karwin see here https://dba.stackexchange.com/questions/6598/innodb-create-table-error-row-size-too-large

They vary by InnoDB file format.At present there are 2 formats called Antelope and Barracuda.

The central tablespace file (ibdata1) is always in Antelope format. If you use file-per-table, you can make the individual files use Barracuda format by setting innodb_file_format=Barracuda in my.cnf.

Basic points:

  1. One 16KB page of InnoDB data must hold at least two rows of data. Plus each page has a header and a footer containing page checksums and log sequence number and so on. That's where you get your limit of a bit less than 8KB per row.

  2. Fixed-size data types like INTEGER, DATE, FLOAT, CHAR are stored on this primary data page and count toward the row size limit.

  3. Variable-sized data types like VARCHAR, TEXT, BLOB are stored on overflow pages, so they don't count fully toward the row size limit. In Antelope, up to 768 bytes of such columns are stored on the primary data page in addition to being stored on the overflow page. Barracuda supports a dynamic row format, so it may store only a 20-byte pointer on the primary data page.

  4. Variable-size data types are also prefixed with 1 or more bytes to encode the length. And InnoDB row format also has an array of field offsets. So there's an internal structure more or less documented in their wiki.

Barracuda also supports a ROW_FORMAT=COMPRESSED to gain further storage efficiency for overflow data.

I also have to comment that I've never seen a well-designed table exceed the row size limit. It's a strong "code smell" that you're violating the repeating groups condition of First Normal Form.

When to use StringBuilder in Java

Ralph's answer is fabulous. I would rather use StringBuilder class to build/decorate the String because the usage of it is more look like Builder pattern.

public String decorateTheString(String orgStr){
            StringBuilder builder = new StringBuilder();
            builder.append(orgStr);
            builder.deleteCharAt(orgStr.length()-1);
            builder.insert(0,builder.hashCode());
            return builder.toString();
}

It can be use as a helper/builder to build the String, not the String itself.

What's the difference between '$(this)' and 'this'?

Yes, you need $(this) for jQuery functions, but when you want to access basic javascript methods of the element that don't use jQuery, you can just use this.

Display a float with two decimal places in Python

Using python string formatting.

>>> "%0.2f" % 3
'3.00'

PHP cURL vs file_get_contents

In addition to this, due to some recent website hacks we had to secure our sites more. In doing so, we discovered that file_get_contents failed to work, where curl still would work.

Not 100%, but I believe that this php.ini setting may have been blocking the file_get_contents request.

; Disable allow_url_fopen for security reasons
allow_url_fopen = 0

Either way, our code now works with curl.

How to make a div with a circular shape?

.circle {
    border-radius: 50%;
    width: 500px;
    height: 500px;
    background: red;
}

<div class="circle"></div>

see this FIDDLE

What is the instanceof operator in JavaScript?

The other answers here are correct, but they don't get into how instanceof actually works, which may be of interest to some language lawyers out there.

Every object in JavaScript has a prototype, accessible through the __proto__ property. Functions also have a prototype property, which is the initial __proto__ for any objects created by them. When a function is created, it is given a unique object for prototype. The instanceof operator uses this uniqueness to give you an answer. Here's what instanceof might look like if you wrote it as a function.

function instance_of(V, F) {
  var O = F.prototype;
  V = V.__proto__;
  while (true) {
    if (V === null)
      return false;
    if (O === V)
      return true;
    V = V.__proto__;
  }
}

This is basically paraphrasing ECMA-262 edition 5.1 (also known as ES5), section 15.3.5.3.

Note that you can reassign any object to a function's prototype property, and you can reassign an object's __proto__ property after it is constructed. This will give you some interesting results:

function F() { }
function G() { }
var p = {};
F.prototype = p;
G.prototype = p;
var f = new F();
var g = new G();

f instanceof F;   // returns true
f instanceof G;   // returns true
g instanceof F;   // returns true
g instanceof G;   // returns true

F.prototype = {};
f instanceof F;   // returns false
g.__proto__ = {};
g instanceof G;   // returns false

How to get AIC from Conway–Maxwell-Poisson regression via COM-poisson package in R?

I figured out myself.

cmp calls ComputeBetasAndNuHat which returns a list which has objective as minusloglik

So I can change the function cmp to get this value.

Is it safe to clean docker/overlay2/

Docker uses /var/lib/docker to store your images, containers, and local named volumes. Deleting this can result in data loss and possibly stop the engine from running. The overlay2 subdirectory specifically contains the various filesystem layers for images and containers.

To cleanup unused containers and images, see docker system prune. There are also options to remove volumes and even tagged images, but they aren't enabled by default due to the possibility of data loss.

How do I set combobox read-only or user cannot write in a combo box only can select the given items?

I think you want to change the setting called "DropDownStyle" to be "DropDownList".

Powershell 2 copy-item which creates a folder if doesn't exist

In PowerShell 2.0, it is still not possible to get the Copy-Item cmdlet to create the destination folder, you'll need code like this:

$destinationFolder = "C:\My Stuff\Subdir"

if (!(Test-Path -path $destinationFolder)) {New-Item $destinationFolder -Type Directory}
Copy-Item "\\server1\Upgrade.exe" -Destination $destinationFolder

If you use -Recurse in the Copy-Item it will create all the subfolders of the source structure in the destination but it won't create the actual destination folder, even with -Force.

JQuery: if div is visible

You can use .is(':visible')

Selects all elements that are visible.

For example:

if($('#selectDiv').is(':visible')){

Also, you can get the div which is visible by:

$('div:visible').callYourFunction();

Live example:

_x000D_
_x000D_
console.log($('#selectDiv').is(':visible'));_x000D_
console.log($('#visibleDiv').is(':visible'));
_x000D_
#selectDiv {_x000D_
  display: none;  _x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div id="selectDiv"></div>_x000D_
<div id="visibleDiv"></div>
_x000D_
_x000D_
_x000D_

Downloading a picture via urllib and python

Python 2

Using urllib.urlretrieve

import urllib
urllib.urlretrieve("http://www.gunnerkrigg.com//comics/00000001.jpg", "00000001.jpg")

Python 3

Using urllib.request.urlretrieve (part of Python 3's legacy interface, works exactly the same)

import urllib.request
urllib.request.urlretrieve("http://www.gunnerkrigg.com//comics/00000001.jpg", "00000001.jpg")

How to flush output after each `echo` call?

Try this:

while (@ob_end_flush());      
ob_implicit_flush(true);

echo "first line visible to the browser";
echo "<br />";

sleep(5);

echo "second line visible to the browser after 5 secs";

Just notice that this way you're actually disabling the output buffer for your current script. I guess you can reenable it with ob_start() (i'm not sure).

Important thing is that by disabling your output buffer like above, you will not be able to redirect your php script anymore using the header() function, because php can sent only once per script execution http headers. You can however redirect using javascript. Just let your php script echo following lines when it comes to that:

        echo '<script type="text/javascript">';
        echo 'window.location.href="'.$url.'";';
        echo '</script>';
        echo '<noscript>';
        echo '<meta http-equiv="refresh" content="0;url='.$url.'" />';
        echo '</noscript>'; 
        exit;

Using lodash to compare jagged arrays (items existence without order)

By 'the same' I mean that there are is no item in array1 that is not contained in array2.

You could use flatten() and difference() for this, which works well if you don't care if there are items in array2 that aren't in array1. It sounds like you're asking is array1 a subset of array2?

var array1 = [['a', 'b'], ['b', 'c']];
var array2 = [['b', 'c'], ['a', 'b']];

function isSubset(source, target) {
    return !_.difference(_.flatten(source), _.flatten(target)).length;
}

isSubset(array1, array2); // ? true
array1.push('d');
isSubset(array1, array2); // ? false
isSubset(array2, array1); // ? true

what is the basic difference between stack and queue?

You can think of both as an ordered list of things (ordered by the time at which they were added to the list). The main difference between the two is how new elements enter the list and old elements leave the list.

For a stack, if I have a list a, b, c, and I add d, it gets tacked on the end, so I end up with a,b,c,d. If I want to pop an element of the list, I remove the last element I added, which is d. After a pop, my list is now a,b,c again

For a queue, I add new elements in the same way. a,b,c becomes a,b,c,d after adding d. But, now when I pop, I have to take an element from the front of the list, so it becomes b,c,d.

It's very simple!

Bootstrap navbar Active State not working

All you need to do is simply add data-toggle="tab" to your link inside bootstrap navbar like this:

<ul class="nav navbar-nav">
  <li class="active"><a data-toggle="tab" href="#">Home</a></li>
  <li><a data-toggle="tab" href="#">Test</a></li>
  <li><a data-toggle="tab" href="#">Test2</a></li>
</ul>

How can I INSERT data into two tables simultaneously in SQL Server?

You could write a stored procedure that iterates over the transaction that you have proposed. The iterator would be the cursor for the table that contains the source data.

A good Sorted List for Java

To test the efficiancy of earlier awnser by Konrad Holl, I did a quick comparison with what I thought would be the slow way of doing it:

package util.collections;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;

/**
 *
 * @author Earl Bosch
 * @param <E> Comparable Element
 *
 */
public class SortedList<E extends Comparable> implements List<E> {

    /**
     * The list of elements
     */
    private final List<E> list = new ArrayList();

    public E first() {
        return list.get(0);
    }

    public E last() {
        return list.get(list.size() - 1);
    }

    public E mid() {
        return list.get(list.size() >>> 1);
    }

    @Override
    public void clear() {
        list.clear();
    }

    @Override
    public boolean add(E e) {
        list.add(e);
        Collections.sort(list);
        return true;
    }

    @Override
    public int size() {
        return list.size();
    }

    @Override
    public boolean isEmpty() {
        return list.isEmpty();
    }

    @Override
    public boolean contains(Object obj) {
        return list.contains((E) obj);
    }

    @Override
    public Iterator<E> iterator() {
        return list.iterator();
    }

    @Override
    public Object[] toArray() {
        return list.toArray();
    }

    @Override
    public <T> T[] toArray(T[] arg0) {
        return list.toArray(arg0);
    }

    @Override
    public boolean remove(Object obj) {
        return list.remove((E) obj);
    }

    @Override
    public boolean containsAll(Collection<?> c) {
        return list.containsAll(c);
    }

    @Override
    public boolean addAll(Collection<? extends E> c) {

        list.addAll(c);
        Collections.sort(list);
        return true;
    }

    @Override
    public boolean addAll(int index, Collection<? extends E> c) {
        throw new UnsupportedOperationException("Not supported.");
    }

    @Override
    public boolean removeAll(Collection<?> c) {
        return list.removeAll(c);
    }

    @Override
    public boolean retainAll(Collection<?> c) {
        return list.retainAll(c);
    }

    @Override
    public E get(int index) {
        return list.get(index);
    }

    @Override
    public E set(int index, E element) {
        throw new UnsupportedOperationException("Not supported.");
    }

    @Override
    public void add(int index, E element) {
        throw new UnsupportedOperationException("Not supported.");
    }

    @Override
    public E remove(int index) {
        return list.remove(index);
    }

    @Override
    public int indexOf(Object obj) {
        return list.indexOf((E) obj);
    }

    @Override
    public int lastIndexOf(Object obj) {
        return list.lastIndexOf((E) obj);
    }

    @Override
    public ListIterator<E> listIterator() {
        return list.listIterator();
    }

    @Override
    public ListIterator<E> listIterator(int index) {
        return list.listIterator(index);
    }

    @Override
    public List<E> subList(int fromIndex, int toIndex) {
        throw new UnsupportedOperationException("Not supported.");
    }

}

Turns out its about twice as fast! I think its because of SortedLinkList slow get - which make's it not a good choice for a list.

Compared times for same random list:

  • SortedLinkList : 15731.460
  • SortedList : 6895.494
  • ca.odell.glazedlists.SortedList : 712.460
  • org.apache.commons.collections4.TreeList : 3226.546

Seems glazedlists.SortedList is really fast...

Redirecting to a page after submitting form in HTML

For anyone else having the same problem, I figured it out myself.

_x000D_
_x000D_
    <html>_x000D_
      <body>_x000D_
        <form target="_blank" action="https://website.com/action.php" method="POST">_x000D_
          <input type="hidden" name="fullname" value="Sam" />_x000D_
          <input type="hidden" name="city" value="Dubai&#32;" />_x000D_
          <input onclick="window.location.href = 'https://website.com/my-account';" type="submit" value="Submit request" />_x000D_
        </form>_x000D_
      </body>_x000D_
    </html>
_x000D_
_x000D_
_x000D_

All I had to do was add the target="_blank" attribute to inline on form to open the response in a new page and redirect the other page using onclick on the submit button.

How to add a new row to datagridview programmatically

Like this:

 dataGridView1.Columns[0].Name = "column2";
 dataGridView1.Columns[1].Name = "column6";

 string[] row1 = new string[] { "column2 value", "column6 value" };
 dataGridView1.Rows.Add(row1);

Or you need to set there values individually use the propery .Rows(), like this:

 dataGridView1.Rows[1].Cells[0].Value = "cell value";

How to install plugins to Sublime Text 2 editor?

According to John Day's answer

You should have a Data/Packages folder in your Sublime Text 2 install directory. All you need to do is download the plugin and put the plugin folder in the Packages folder.

In case if you are searching for Data/Packages folder you can find it here

Windows: %APPDATA%\Sublime Text 2

OS X: ~/Library/Application Support/Sublime Text 2

Linux: ~/.Sublime Text 2

Portable Installation: Sublime Text 2/Data

How to get the input from the Tkinter Text Widget?

I did come also in search of how to get input data from the Text widget. Regarding the problem with a new line on the end of the string. You can just use .strip() since it is a Text widget that is always a string.

Also, I'm sharing code where you can see how you can create multiply Text widgets and save them in the dictionary as form data, and then by clicking the submit button get that form data and do whatever you want with it. I hope it helps others. It should work in any 3.x python and probably will work in 2.7 also.

from tkinter import *
from functools import partial

class SimpleTkForm(object):
    def __init__(self):
        self.root = Tk()

    def myform(self):
        self.root.title('My form')
        frame = Frame(self.root, pady=10)
        form_data = dict()
        form_fields = ['username', 'password', 'server name', 'database name']
        cnt = 0
        for form_field in form_fields:
            Label(frame, text=form_field, anchor=NW).grid(row=cnt,column=1, pady=5, padx=(10, 1), sticky="W")
            textbox = Text(frame, height=1, width=15)
            form_data.update({form_field: textbox})
            textbox.grid(row=cnt,column=2, pady=5, padx=(3,20))
            cnt += 1

        conn_test = partial(self.test_db_conn, form_data=form_data)
        Button(frame, text='Submit', width=15, command=conn_test).grid(row=cnt,column=2, pady=5, padx=(3,20))
        frame.pack()
        self.root.mainloop()

    def test_db_conn(self, form_data):
        data = {k:v.get('1.0', END).strip() for k,v in form_data.items()}
        # validate data or do anything you want with it
        print(data)


if __name__ == '__main__':
    api = SimpleTkForm()
    api.myform()

jQuery attr() change img src

  1. Function imageMorph will create a new img element therefore the id is removed. Changed to

    $("#wrapper > img")

  2. You should use live() function for click event if you want you rocket lanch again.

Updated demo: http://jsfiddle.net/ynhat/QQRsW/4/

How do I simulate a hover with a touch in touch enabled browsers?

Try this:

<script>
document.addEventListener("touchstart", function(){}, true);
</script>

And in your CSS:

element:hover, element:active {
-webkit-tap-highlight-color: rgba(0,0,0,0);
-webkit-user-select: none;
-webkit-touch-callout: none /*only to disable context menu on long press*/
}

With this code you don't need an extra .hover class!

Get $_POST from multiple checkboxes

Edit To reflect what @Marc said in the comment below.

You can do a loop through all the posted values.

HTML:

<input type="checkbox" name="check_list[]" value="<?=$rowid?>" />
<input type="checkbox" name="check_list[]" value="<?=$rowid?>" />
<input type="checkbox" name="check_list[]" value="<?=$rowid?>" />

PHP:

foreach($_POST['check_list'] as $item){
  // query to delete where item = $item
}

How to construct a WebSocket URI relative to the page URI?

Dead easy solution, ws and port, tested:

var ws = new WebSocket("ws://" + window.location.host + ":6666");

ws.onopen = function() { ws.send( .. etc

Filling a List with all enum values in Java

There is a constructor for ArrayList which is

ArrayList(Collection<? extends E> c) 

Now, EnumSet extends AbstractCollection so you can just do

ArrayList<Something> all = new ArrayList<Something>(enumSet)

mkdir -p functionality in Python

With Pathlib from python3 standard library:

Path(mypath).mkdir(parents=True, exist_ok=True)

If parents is true, any missing parents of this path are created as needed; they are created with the default permissions without taking mode into account (mimicking the POSIX mkdir -p command). If exist_ok is false (the default), an FileExistsError is raised if the target directory already exists.

If exist_ok is true, FileExistsError exceptions will be ignored (same behavior as the POSIX mkdir -p command), but only if the last path component is not an existing non-directory file.

Changed in version 3.5: The exist_ok parameter was added.

sqlite3.ProgrammingError: Incorrect number of bindings supplied. The current statement uses 1, and there are 74 supplied

cursor.execute(sql,array)

Only takes two arguments.
It will iterate the "array"-object and match ? in the sql-string.
(with sanity checks to avoid sql-injection)

Vagrant ssh authentication failure

If you experience this issue on vagrant 1.8.5, then check out this thread on github:

https://github.com/mitchellh/vagrant/issues/7610

It's caused basically by a permission issue, the workaround is just

vagrant ssh 
password: vagrant 
chmod 0600 ~/.ssh/authorized_keys
exit

then

vagrant reload 

FYI: this issue only affects CentOS, Ubuntu works fine.

How do I open the "front camera" on the Android platform?

All older answers' methods are deprecated by Google (supposedly because of troubles like this), since API 21 you need to use the Camera 2 API:

This class was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications.

In the newer API you have almost complete power over the Android device camera and documentation explicitly advice to

String[] getCameraIdList()

and then use obtained CameraId to open the camera:

void openCamera(String cameraId, CameraDevice.StateCallback callback, Handler handler)

99% of the frontal cameras have id = "1", and the back camera id = "0" according to this:

Non-removable cameras use integers starting at 0 for their identifiers, while removable cameras have a unique identifier for each individual device, even if they are the same model.

However, this means if device situation is rare like just 1-frontal -camera tablet you need to count how many embedded cameras you have, and place the order of the camera by its importance ("0"). So CAMERA_FACING_FRONT == 1 CAMERA_FACING_BACK == 0, which implies that the back camera is more important than frontal.

I don't know about a uniform method to identify the frontal camera on all Android devices. Simply said, the Android OS inside the device can't really find out which camera is exactly where for some reasons: maybe the only camera hardcoded id is an integer representing its importance or maybe on some devices whichever side you turn will be .. "back".

Documentation: https://developer.android.com/reference/android/hardware/camera2/package-summary.html

Explicit Examples: https://github.com/googlesamples/android-Camera2Basic


For the older API (it is not recommended, because it will not work on modern phones newer Android version and transfer is a pain-in-the-arse). Just use the same Integer CameraID (1) to open frontal camera like in this answer:

cam = Camera.open(1);

If you trust OpenCV to do the camera part:

Inside

    <org.opencv.android.JavaCameraView
    ../>

use the following for the frontal camera:

        opencv:camera_id="1"

How to install PyQt4 in anaconda?

FYI

PyQt is now available on all platforms via conda!
Use conda install pyqt to get these #Python bindings for the Qt framework. @ 1:02 PM - 1 May 2014

https://twitter.com/ContinuumIO/status/461958764451880960

Where to place the 'assets' folder in Android Studio?

In Android Studio 4.1.1

Right Click on your module (app for example) -> New -> Folder -> Assets Folder

enter image description here

Error:(1, 0) Plugin with id 'com.android.application' not found

In this case of issues check below code

dependencies {
    classpath 'com.android.tools.build:gradle:**1.5.0**'
}

and gradle-wrapper.properties inside your project directory check below disctributionUrl:

distributionUrl=https\://services.gradle.org/distributions/gradle-2.9-all.zip

If these are not compatible with each other then you end up in this issue.

For com.android.tools.build:gradle:1.5. you need a version at least 2.8 but if you switch to a higher version like com.android.tools.build:gradle:2.1.0 then you need to update your gradle to 2.9 and above this can be done by changing distributionUrl in gradle-wrapper.properties to 2.9 or higher as below

distributionUrl=https\://services.gradle.org/distributions/gradle-2.10-all.zip

Transparent color of Bootstrap-3 Navbar

you can use this for your css , mainly use css3 rgba as your background in order to control the opacity and use a background fallback for older browser , either using a solid color or a transparent .png image.

.navbar {
   background:rgba(0,0,0,0.5);   /* for latest browsers */
   background: #000;  /* fallback for older browsers */
}

More info: http://css-tricks.com/rgba-browser-support/

How to get screen width without (minus) scrollbar?

Here are some examples which assume $element is a jQuery element:

// Element width including overflow (scrollbar)
$element[0].offsetWidth; // 1280 in your case

// Element width excluding overflow (scrollbar)
$element[0].clientWidth; // 1280 - scrollbarWidth

// Scrollbar width
$element[0].offsetWidth - $element[0].clientWidth; // 0 if no scrollbar

How to represent a DateTime in Excel

You can do the following:

=Datevalue(text)+timevalue(text) .

Go into different types of date formats and choose:

dd-mm-yyyy mm:ss am/pm .

How can I draw vertical text with CSS cross-browser?

Another solution is to use an SVG text node which is supported by most browsers.

<svg width="50" height="300">
    <text x="28" y="150" transform="rotate(-90, 28, 150)" style="text-anchor:middle; font-size:14px">This text is vertical</text>
</svg>

Demo: https://jsfiddle.net/bkymb5kr/

More on SVG text: http://tutorials.jenkov.com/svg/text-element.html

React prevent event bubbling in nested components on click

React uses event delegation with a single event listener on document for events that bubble, like 'click' in this example, which means stopping propagation is not possible; the real event has already propagated by the time you interact with it in React. stopPropagation on React's synthetic event is possible because React handles propagation of synthetic events internally.

stopPropagation: function(e){
    e.stopPropagation();
    e.nativeEvent.stopImmediatePropagation();
}

SQL SELECT everything after a certain character

Try this in MySQL.

right(field,((CHAR_LENGTH(field))-(InStr(field,','))))

Setting the filter to an OpenFileDialog to allow the typical image formats?

In order to match a list of different categories of file, you can use the filter like this:

        var dlg = new Microsoft.Win32.OpenFileDialog()
        {
            DefaultExt = ".xlsx",
            Filter = "Excel Files (*.xls, *.xlsx)|*.xls;*.xlsx|CSV Files (*.csv)|*.csv"
        };

What's the difference between getPath(), getAbsolutePath(), and getCanonicalPath() in Java?

The best way I have found to get a feel for things like this is to try them out:

import java.io.File;
public class PathTesting {
    public static void main(String [] args) {
        File f = new File("test/.././file.txt");
        System.out.println(f.getPath());
        System.out.println(f.getAbsolutePath());
        try {
            System.out.println(f.getCanonicalPath());
        }
        catch(Exception e) {}
    }
}

Your output will be something like:

test\..\.\file.txt
C:\projects\sandbox\trunk\test\..\.\file.txt
C:\projects\sandbox\trunk\file.txt

So, getPath() gives you the path based on the File object, which may or may not be relative; getAbsolutePath() gives you an absolute path to the file; and getCanonicalPath() gives you the unique absolute path to the file. Notice that there are a huge number of absolute paths that point to the same file, but only one canonical path.

When to use each? Depends on what you're trying to accomplish, but if you were trying to see if two Files are pointing at the same file on disk, you could compare their canonical paths. Just one example.

Responsive design with media query : screen size?

Here is media queries for common device breakpoints.

    /* Smartphones (portrait and landscape) ----------- */
@media only screen and (min-device-width : 320px) and (max-device-width : 480px) {
/* Styles */
}

/* Smartphones (landscape) ----------- */
@media only screen and (min-width : 321px) {
/* Styles */
}

/* Smartphones (portrait) ----------- */
@media only screen and (max-width : 320px) {
/* Styles */
}

/* iPads (portrait and landscape) ----------- */
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) {
/* Styles */
}

/* iPads (landscape) ----------- */
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) and (orientation : landscape) {
/* Styles */
}

/* iPads (portrait) ----------- */
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) and (orientation : portrait) {
/* Styles */
}
/**********
iPad 3
**********/
@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) and (orientation : landscape) and (-webkit-min-device-pixel-ratio : 2) {
/* Styles */
}

@media only screen and (min-device-width : 768px) and (max-device-width : 1024px) and (orientation : portrait) and (-webkit-min-device-pixel-ratio : 2) {
/* Styles */
}
/* Desktops and laptops ----------- */
@media only screen  and (min-width : 1224px) {
/* Styles */
}

/* Large screens ----------- */
@media only screen  and (min-width : 1824px) {
/* Styles */
}

/* iPhone 4 ----------- */
@media only screen and (min-device-width : 320px) and (max-device-width : 480px) and (orientation : landscape) and (-webkit-min-device-pixel-ratio : 2) {
/* Styles */
}

@media only screen and (min-device-width : 320px) and (max-device-width : 480px) and (orientation : portrait) and (-webkit-min-device-pixel-ratio : 2) {
/* Styles */
}

error opening trace file: No such file or directory (2)

I think this is the problem

A little background

Traceview is a graphical viewer for execution logs that you create by using the Debug class to log tracing information in your code. Traceview can help you debug your application and profile its performance. Enabling it creates a .trace file in the sdcard root folder which can then be extracted by ADB and processed by traceview bat file for processing. It also can get added by the DDMS.

It is a system used internally by the logger. In general unless you are using traceview to extract the trace file this error shouldnt bother you. You should look at error/logs directly related to your application

How do I enable it:

There are two ways to generate trace logs:

  1. Include the Debug class in your code and call its methods such as startMethodTracing() and stopMethodTracing(), to start and stop logging of trace information to disk. This option is very precise because you can specify exactly where to start and stop logging trace data in your code.

  2. Use the method profiling feature of DDMS to generate trace logs. This option is less precise because you do not modify code, but rather specify when to start and stop logging with DDMS. Although you have less control on exactly where logging starts and stops, this option is useful if you don't have access to the application's code, or if you do not need precise log timing.

But the following restrictions exist for the above

If you are using the Debug class, your application must have permission to write to external storage (WRITE_EXTERNAL_STORAGE).

If you are using DDMS: Android 2.1 and earlier devices must have an SD card present and your application must have permission to write to the SD card. Android 2.2 and later devices do not need an SD card. The trace log files are streamed directly to your development machine.

So in essence the traceFile access requires two things

1.) Permission to write a trace log file i.e. WRITE_EXTERNAL_STORAGE and READ_EXTERNAL_STORAGE for good measure

2.) An emulator with an SDCard attached with sufficient space. The doc doesnt say if this is only for DDMS but also for debug, so I am assuming this is also true for debugging via the application.

What do I do with this error:

Now the error is essentially a fall out of either not having the sdcard path to create a tracefile or not having permission to access it. This is an old thread, but the dev behind the bounty, check if are meeting the two prerequisites. You can then go search for the .trace file in the sdcard folder in your emulator. If it exists it shouldn't be giving you this problem, if it doesnt try creating it by adding the startMethodTracing to your app.
I'm not sure why it automatically looks for this file when the logger kicks in. I think when an error/log event occurs , the logger internally tries to write to trace file and does not find it, in which case it throws the error.Having scoured through the docs, I don't find too many references to why this is automatically on. But in general this doesn't affect you directly, you should check direct application logs/errors. Also as an aside Android 2.2 and later devices do not need an SD card for DDMS trace logging. The trace log files are streamed directly to your development machine.

Additional information on Traceview:

Copying Trace Files to a Host Machine

After your application has run and the system has created your trace files .trace on a device or emulator, you must copy those files to your development computer. You can use adb pull to copy the files. Here's an example that shows how to copy an example file, calc.trace, from the default location on the emulator to the /tmp directory on the emulator host machine:

adb pull /sdcard/calc.trace /tmp Viewing Trace Files in Traceview To run Traceview and view the trace files, enter traceview . For example, to run Traceview on the example files copied in the previous section, use:

traceview /tmp/calc Note: If you are trying to view the trace logs of an application that is built with ProGuard enabled (release mode build), some method and member names might be obfuscated. You can use the Proguard mapping.txt file to figure out the original unobfuscated names. For more information on this file, see the Proguard documentation.

I think any other answer regarding positioning of oncreate statements or removing uses-sdk are not related, but this is Android and I could be wrong. Would be useful to redirect this question to an android engineer or post it as a bug

More in the docs

Assigning strings to arrays of characters

There is no such thing as a "string" in C. In C, strings are one-dimensional array of char, terminated by a null character \0. Since you can't assign arrays in C, you can't assign strings either. The literal "hello" is syntactic sugar for const char x[] = {'h','e','l','l','o','\0'};

The correct way would be:

char s[100];
strncpy(s, "hello", 100);

or better yet:

#define STRMAX 100
char    s[STRMAX];
size_t  len;
len = strncpy(s, "hello", STRMAX);

PDF to byte array and vice versa

Calling toString() on an InputStream doesn't do what you think it does. Even if it did, a PDF contains binary data, so you wouldn't want to convert it to a string first.

What you need to do is read from the stream, write the results into a ByteArrayOutputStream, then convert the ByteArrayOutputStream into an actual byte array by calling toByteArray():

InputStream inputStream = new FileInputStream(sourcePath);
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();

int data;
while( (data = inputStream.read()) >= 0 ) {
    outputStream.write(data);
}

inputStream.close();
return outputStream.toByteArray();

How to quickly test some javascript code?

If you want to edit some complex javascript I suggest you use JsFiddle. Alternatively, for smaller pieces of javascript you can just run it through your browser URL bar, here's an example:

javascript:alert("hello world");

And, as it was already suggested both Firebug and Chrome developer tools have Javascript console, in which you can type in your javascript to execute. So do Internet Explorer 8+, Opera, Safari and potentially other modern browsers.

How to reset all checkboxes using jQuery or pure JS?

As said in Tatu Ulmanen's answer using the follow script will do the job

$('input:checkbox').removeAttr('checked');

But, as Blakomen's comment said, after version 1.6 it's better to use jQuery.prop() instead

Note that in jQuery v1.6 and higher, you should be using .prop('checked', false) instead for greater cross-browser compatibility

$('input:checkbox').prop('checked', false);

Be careful when using jQuery.each() it may cause performance issues. (also, avoid jQuery.find() in those case. Use each instead)

$('input[type=checkbox]').each(function() 
{ 
    $(this).prop('checked', false); 
});

Could not load file or assembly ... The parameter is incorrect

Just clear this folder: (only windows x64)

C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files

what is the difference between ajax and jquery and which one is better?

It's really not an 'either/or' situation. AJAX stands for Asynchronous JavaScript and XML, and JQuery is a JavaScript library that takes the pain out of writing common JavaScript routines.

It's the difference between a thing (jQuery) and a process (AJAX). To compare them would be to compare apples and oranges.

error: the details of the application error from being viewed remotely

This can be the message you receive even when custom errors is turned off in web.config file. It can mean you have run out of free space on the drive that hosts the application. Clean your log files if you have no other space to gain on the drive.

Data truncation: Data too long for column 'logo' at row 1

You are trying to insert data that is larger than allowed for the column logo.

Use following data types as per your need

TINYBLOB   :     maximum length of 255 bytes  
BLOB       :     maximum length of 65,535 bytes  
MEDIUMBLOB :     maximum length of 16,777,215 bytes  
LONGBLOB   :     maximum length of 4,294,967,295 bytes  

Use LONGBLOB to avoid this exception.

jQuery or JavaScript auto click

First i tried with this sample code:

$(document).ready(function(){ 
     $('#upload-file').click(); 
});

It didn't work for me. Then after, tried with this

$(document).ready(function(){ 
     $('#upload-file')[0].click(); 
});

No change. At last, tried with this

$(document).ready(function(){ 
     $('#upload-file')[0].click(function(){
     }); 
});

Solved my problem. Helpful for anyone.

Adding a rule in iptables in debian to open a new port

About your command line:

root@debian:/# sudo iptables -A INPUT -p tcp --dport 3306 --jump ACCEPT
root@debian:/# iptables-save
  • You are already authenticated as root so sudo is redundant there.

  • You are missing the -j or --jump just before the ACCEPT parameter (just tought that was a typo and you are inserting it correctly).

About yout question:

If you are inserting the iptables rule correctly as you pointed it in the question, maybe the issue is related to the hypervisor (virtual machine provider) you are using.

If you provide the hypervisor name (VirtualBox, VMWare?) I can further guide you on this but here are some suggestions you can try first:

check your vmachine network settings and:

  • if it is set to NAT, then you won't be able to connect from your base machine to the vmachine.

  • if it is set to Hosted, you have to configure first its network settings, it is usually to provide them an IP in the range 192.168.56.0/24, since is the default the hypervisors use for this.

  • if it is set to Bridge, same as Hosted but you can configure it whenever IP range makes sense for you configuration.

Hope this helps.

Differences between hard real-time, soft real-time, and firm real-time?

Hard Real-Time

The hard real-time definition considers any missed deadline to be a system failure. This scheduling is used extensively in mission critical systems where failure to conform to timing constraints results in a loss of life or property.

Examples:

  • Air France Flight 447 crashed into the ocean after a sensor malfunction caused a series of system errors. The pilots stalled the aircraft while responding to outdated instrument readings. All 12 crew and 216 passengers were killed.

  • Mars Pathfinder spacecraft was nearly lost when a priority inversion caused system restarts. A higher priority task was not completed on time due to being blocked by a lower priority task. The problem was corrected and the spacecraft landed successfully.

  • An Inkjet printer has a print head with control software for depositing the correct amount of ink onto a specific part of the paper. If a deadline is missed then the print job is ruined.


Firm Real-Time

The firm real-time definition allows for infrequently missed deadlines. In these applications the system can survive task failures so long as they are adequately spaced, however the value of the task's completion drops to zero or becomes impossible.

Examples:

  • Manufacturing systems with robot assembly lines where missing a deadline results in improperly assembling a part. As long as ruined parts are infrequent enough to be caught by quality control and not too costly, then production continues.

  • A digital cable set-top box decodes time stamps for when frames must appear on the screen. Since the frames are time order sensitive a missed deadline causes jitter, diminishing quality of service. If the missed frame later becomes available it will only cause more jitter to display it, so it's useless. The viewer can still enjoy the program if jitter doesn't occur too often.


Soft Real-Time

The soft real-time definition allows for frequently missed deadlines, and as long as tasks are timely executed their results continue to have value. Completed tasks may have increasing value up to the deadline and decreasing value past it.

Examples:

  • Weather stations have many sensors for reading temperature, humidity, wind speed, etc. The readings should be taken and transmitted at regular intervals, however the sensors are not synchronized. Even though a sensor reading may be early or late compared with the others it can still be relevant as long as it is close enough.

  • A video game console runs software for a game engine. There are many resources that must be shared between its tasks. At the same time tasks need to be completed according to the schedule for the game to play correctly. As long as tasks are being completely relatively on time the game will be enjoyable, and if not it may only lag a little.


Siewert: Real-Time Embedded Systems and Components.
Liu & Layland: Scheduling Algorithms for Multiprogramming in a Hard Real-Time Environment.
Marchand & Silly-Chetto: Dynamic Scheduling of Soft Aperiodic Tasks and Periodic Tasks with Skips.

Top 5 time-consuming SQL queries in Oracle

You could take the average buffer gets per execution during a period of activity of the instance:

SELECT username,
       buffer_gets,
       disk_reads,
       executions,
       buffer_get_per_exec,
       parse_calls,
       sorts,
       rows_processed,
       hit_ratio,
       module,
       sql_text
       -- elapsed_time, cpu_time, user_io_wait_time, ,
  FROM (SELECT sql_text,
               b.username,
               a.disk_reads,
               a.buffer_gets,
               trunc(a.buffer_gets / a.executions) buffer_get_per_exec,
               a.parse_calls,
               a.sorts,
               a.executions,
               a.rows_processed,
               100 - ROUND (100 * a.disk_reads / a.buffer_gets, 2) hit_ratio,
               module
               -- cpu_time, elapsed_time, user_io_wait_time
          FROM v$sqlarea a, dba_users b
         WHERE a.parsing_user_id = b.user_id
           AND b.username NOT IN ('SYS', 'SYSTEM', 'RMAN','SYSMAN')
           AND a.buffer_gets > 10000
         ORDER BY buffer_get_per_exec DESC)
 WHERE ROWNUM <= 20

How can I make git accept a self signed certificate?

I keep coming across this problem, so have written a script to download the self signed certificate from the server and install it to ~/.gitcerts, then update git-config to point to these certificates. It is stored in global config, so you only need to run it once per remote.

https://github.com/iwonbigbro/tools/blob/master/bin/git-remote-install-cert.sh

understanding private setters

I don't understand the need of having private setters which started with C# 2.

Use case example:

I have an instance of an application object 'UserInfo' that contains a property SessionTokenIDV1 that I don't wish to expose to consumers of my class.

I also need the ability to set that value from my class.

My solution was to encapsulate the property as shown and make the setter private so that I can set the value of the session token without allowing instantiating code to also set it (or even see it in my case)

public class UserInfo
{
   public String SessionTokenIDV1 { get; set; }

}


public class Example
{
  // Private vars
  private UserInfo _userInfo = new UserInfo();

  public string SessionValidV1
  {
    get { return ((_userInfo.SessionTokenIDV1 != null) && (_userInfo.SessionTokenIDV1.Length > 0)) ? "set" : "unset"; }
    private set { _userInfo.SessionTokenIDV1 = value; }
  }
}

Edit: Fixed Code Tag Edit: Example had errors which have been corrected

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

Here is an updated version of Dan Grossman's answer which will cater for multidimensional arrays (what I was after):

function find_key_value($array, $key, $val)
{
    foreach ($array as $item)
    {
        if (is_array($item) && find_key_value($item, $key, $val)) return true;

        if (isset($item[$key]) && $item[$key] == $val) return true;
    }

    return false;
}

How can I schedule a daily backup with SQL Server Express?

Eduardo Molteni had a great answer:

Using Windows Scheduled Tasks:

In the batch file

"C:\Program Files\Microsoft SQL Server\100\Tools\Binn\SQLCMD.EXE" -S 
(local)\SQLExpress -i D:\dbbackups\SQLExpressBackups.sql

In SQLExpressBackups.sql

BACKUP DATABASE MyDataBase1 TO  DISK = N'D:\DBbackups\MyDataBase1.bak' 
WITH NOFORMAT, INIT,  NAME = N'MyDataBase1 Backup', SKIP, NOREWIND, NOUNLOAD,  STATS = 10

BACKUP DATABASE MyDataBase2 TO  DISK = N'D:\DBbackups\MyDataBase2.bak' 
WITH NOFORMAT, INIT,  NAME = N'MyDataBase2 Backup', SKIP, NOREWIND, NOUNLOAD,  STATS = 10

GO

Get the index of the object inside an array, matching a condition

Another easy way is :

 function getIndex(items) {
        for (const [index, item] of items.entries()) {
            if (item.prop2 === 'yutu') {
                return index;
            }
        }
    }

const myIndex = getIndex(myArray);

script to map network drive

Why not map the network drive but deselect "Reconnect at logon"? The drive will only connect when you try to access it. Note that some applications will fail if they point to it, but if you're accessing files directly through Windows Explorer this works great.

Python: finding an element in a list

Here is another way using list comprehension (some people might find it debatable). It is very approachable for simple tests, e.g. comparisons on object attributes (which I need a lot):

el = [x for x in mylist if x.attr == "foo"][0]

Of course this assumes the existence (and, actually, uniqueness) of a suitable element in the list.

How do you create vectors with specific intervals in R?

In R the equivalent function is seq and you can use it with the option by:

seq(from = 5, to = 100, by = 5)
# [1]   5  10  15  20  25  30  35  40  45  50  55  60  65  70  75  80  85  90  95 100

In addition to by you can also have other options such as length.out and along.with.

length.out: If you want to get a total of 10 numbers between 0 and 1, for example:

seq(0, 1, length.out = 10)
# gives 10 equally spaced numbers from 0 to 1

along.with: It takes the length of the vector you supply as input and provides a vector from 1:length(input).

seq(along.with=c(10,20,30))
# [1] 1 2 3

Although, instead of using the along.with option, it is recommended to use seq_along in this case. From the documentation for ?seq

seq is generic, and only the default method is described here. Note that it dispatches on the class of the first argument irrespective of argument names. This can have unintended consequences if it is called with just one argument intending this to be taken as along.with: it is much better to use seq_along in that case.

seq_along: Instead of seq(along.with(.))

seq_along(c(10,20,30))
# [1] 1 2 3

Hope this helps.

Java: How to Indent XML Generated by Transformer

import com.sun.org.apache.xml.internal.serializer.OutputPropertiesFactory

transformer.setOutputProperty(OutputPropertiesFactory.S_KEY_INDENT_AMOUNT, "2");

What operator is <> in VBA

This is an Inequality operator.

Also,this might be helpful for future: Operators listed by Functionality

C# password TextBox in a ASP.net website

Simply select texbox property 'TextMode' and select password...

<asp:TextBox ID="TextBox1" TextMode="Password" runat="server" />

Add a pipe separator after items in an unordered list unless that item is the last on a line

I know I'm a bit late to the party, but if you can put up with having the lines left-justified, one hack is to put the pipes before the items and then put a mask over the left edge, basically like so:

li::before {
  content: " | ";
  white-space: nowrap;
}

ul, li {
  display: inline;
}

.mask {
  width:4px;
  position: absolute;
  top:8px; //position as needed
}

more complete example: http://jsbin.com/hoyaduxi/1/edit

docker error - 'name is already in use by container'

Cause

A container with the same name is still existing.

Solution

To reuse the same container name, delete the existing container by:

docker rm <container name>

Explanation

Containers can exist in following states, during which the container name can't be used for another container:

  • created
  • restarting
  • running
  • paused
  • exited
  • dead

You can see containers in running state by using :

docker ps

To show containers in all states and find out if a container name is taken, use:

docker ps -a

What is 0x10 in decimal?

It's a hex number and is 16 decimal.

How to right align widget in horizontal linear layout Android?

setting the view's layout_weight="1" would do the trick.!

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">

<TextView
    android:id="@+id/textView1"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_weight="1" />

<RadioButton
    android:id="@+id/radioButton1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"/>

Foreign key referring to primary keys across multiple tables?

I know this is long stagnant topic, but in case anyone searches here is how I deal with multi table foreign keys. With this technique you do not have any DBA enforced cascade operations, so please make sure you deal with DELETE and such in your code.

Table 1 Fruit
pk_fruitid, name
1, apple
2, pear

Table 2 Meat
Pk_meatid, name
1, beef
2, chicken

Table 3 Entity's
PK_entityid, anme
1, fruit
2, meat
3, desert

Table 4 Basket (Table using fk_s)
PK_basketid, fk_entityid, pseudo_entityrow
1, 2, 2 (Chicken - entity denotes meat table, pseudokey denotes row in indictaed table)
2, 1, 1 (Apple)
3, 1, 2 (pear)
4, 3, 1 (cheesecake)

SO Op's Example would look like this

deductions
--------------
type    id      name
1      khce1   gold
2      khsn1   silver

types
---------------------
1 employees_ce
2 employees_sn

ant build.xml file doesn't exist

If you couldn't find the build.xml file in your project then you have to build it to be able to debug it and get your .apk

you can use this command-line to build:

android update project -p "project full path"

where "Project full path" -- Give your full path of your project location

after this you will find the build.xml then you can debug it.

Java command not found on Linux

I use the following script to update the default alternative after install jdk.

#!/bin/bash
export JAVA_BIN_DIR=/usr/java/default/bin # replace with your installed directory
cd ${JAVA_BIN_DIR}
a=(java javac javadoc javah javap javaws)
for exe in ${a[@]}; do
    sudo update-alternatives --install "/usr/bin/${exe}" "${exe}" "${JAVA_BIN_DIR}/${exe}" 1
    sudo update-alternatives --set ${exe} ${JAVA_BIN_DIR}/${exe}
done

SQL Query for Selecting Multiple Records

You're looking for the IN() clause:

SELECT * FROM `Buses` WHERE `BusID` IN (1,2,3,5,7,9,11,44,88,etc...);

What are MVP and MVC and what is the difference?

The simplest answer is how the view interacts with the model. In MVP the view is updated by the presenter, which acts as as intermediary between the view and the model. The presenter takes the input from the view, which retrieves the data from the model and then performs any business logic required and then updates the view. In MVC the model updates the view directly rather than going back through the controller.

How is a non-breaking space represented in a JavaScript string?

&nbsp; is a HTML entity. When doing .text(), all HTML entities are decoded to their character values.

Instead of comparing using the entity, compare using the actual raw character:

var x = td.text();
if (x == '\xa0') { // Non-breakable space is char 0xa0 (160 dec)
  x = '';
}

Or you can also create the character from the character code manually it in its Javascript escaped form:

var x = td.text();
if (x == String.fromCharCode(160)) { // Non-breakable space is char 160
  x = '';
}

More information about String.fromCharCode is available here:

fromCharCode - MDC Doc Center

More information about character codes for different charsets are available here:

Windows-1252 Charset
UTF-8 Charset

How to call URL action in MVC with javascript function?

try:

var url = '/Home/Index/' + e.value;
 window.location = window.location.host + url; 

That should get you where you want.

How to create Temp table with SELECT * INTO tempTable FROM CTE Query

Really the format can be quite simple - sometimes there's no need to predefine a temp table - it will be created from results of the select.

Select FieldA...FieldN 
into #MyTempTable 
from MyTable

So unless you want different types or are very strict on definition, keep things simple. Note also that any temporary table created inside a stored procedure is automatically dropped when the stored procedure finishes executing. If stored procedure A creates a temp table and calls stored procedure B, then B will be able to use the temporary table that A created.

However, it's generally considered good coding practice to explicitly drop every temporary table you create anyway.

What is the difference between "mvn deploy" to a local repo and "mvn install"?

Ken, good question. I should be more explicit in the The Definitive Guide about the difference. "install" and "deploy" serve two different purposes in a build. "install" refers to the process of installing an artifact in your local repository. "deploy" refers to the process of deploying an artifact to a remote repository.

Example:

  1. When I run a large multi-module project on a my machine, I'm going to usually run "mvn install". This is going to install all of the generated binary software artifacts (usually JARs) in my local repository. Then when I build individual modules in the build, Maven is going to retrieve the dependencies from the local repository.

  2. When it comes time to deploy snapshots or releases, I'm going to run "mvn deploy". Running this is going to attempt to deploy the files to a remote repository or server. Usually I'm going to be deploying to a repository manager such as Nexus

It is true that running "deploy" is going to require some extra configuration, you are going to have to supply a distributionManagement section in your POM.

Difference between Big-O and Little-O Notation

The big-O notation has a companion called small-o notation. The big-O notation says the one function is asymptotical no more than another. To say that one function is asymptotically less than another, we use small-o notation. The difference between the big-O and small-o notations is analogous to the difference between <= (less than equal) and < (less than).

How to draw a line in android

Simple one

 <TextView
    android:layout_width="match_parent"
    android:layout_height="1dp"
    android:background="#c0c0c0"
    android:id="@+id/your_id"
    android:layout_marginTop="160dp" />

Reload a DIV without reloading the whole page

Your html is not updated every 15 seconds. The cause could be browser caching. Add Math.random() to avoid browser caching, and it's better to wait until the DOM is fully loaded as pointed out by @shadow. But I think the main cause is the caching

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.0/jquery.min.js" />
<script type="text/javascript">
$(document).ready(function(){
    var auto_refresh = setInterval(
    function ()
    {
       $('.View').load('Small.php?' + Math.random()).fadeIn("slow");
    }, 15000); // refresh every 15000 milliseconds
});
</script>

Scanner vs. BufferedReader

Scanner is used for parsing tokens from the contents of the stream while BufferedReader just reads the stream and does not do any special parsing.

In fact you can pass a BufferedReader to a scanner as the source of characters to parse.

Pure CSS to make font-size responsive based on dynamic amount of characters

For reference, a non-CSS solution:

Below is some JS that re-sizes a font depending on the text length within a container.

Codepen with slightly modified code, but same idea as below:

function scaleFontSize(element) {
    var container = document.getElementById(element);

    // Reset font-size to 100% to begin
    container.style.fontSize = "100%";

    // Check if the text is wider than its container,
    // if so then reduce font-size
    if (container.scrollWidth > container.clientWidth) {
        container.style.fontSize = "70%";
    }
}

For me, I call this function when a user makes a selection in a drop-down, and then a div in my menu gets populated (this is where I have dynamic text occurring).

    scaleFontSize("my_container_div");

In addition, I also use CSS ellipses ("...") to truncate yet even longer text too, like so:

#my_container_div {
    width: 200px; /* width required for text-overflow to work */
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

So, ultimately:

  • Short text: e.g. "APPLES"

    Fully rendered, nice big letters.

  • Long text: e.g. "APPLES & ORANGES"

    Gets scaled down 70%, via the above JS scaling function.

  • Super long text: e.g. "APPLES & ORANGES & BANAN..."

    Gets scaled down 70% AND gets truncated with a "..." ellipses, via the above JS scaling function together with the CSS rule.

You could also explore playing with CSS letter-spacing to make text narrower while keeping the same font size.

hide/show a image in jquery

<script>
function show_image(id)
{
    if(id =='band')
    {
       $("#upload").hide();
       $("#bandwith").show();
    }
    else if(id =='up')
    {
        $("#upload").show();
        $("#bandwith").hide();
    }
} 
</script>

<a href="#" onclick="javascript:show_image('bandwidth');">Bandwidth</a>
<a href="#" onclick="javascript:show_image('upload');">Upload</a>

<img src="img/im.png" id="band" style="visibility: hidden;" />
<img src="img/im1.png" id="up" style="visibility: hidden;" />

Fixed Table Cell Width

Now in HTML5/CSS3 we have better solution for the problem. In my opinion this purely CSS solution is recommended:

_x000D_
_x000D_
table.fixed {table-layout:fixed; width:90px;}/*Setting the table width is important!*/_x000D_
table.fixed td {overflow:hidden;}/*Hide text outside the cell.*/_x000D_
table.fixed td:nth-of-type(1) {width:20px;}/*Setting the width of column 1.*/_x000D_
table.fixed td:nth-of-type(2) {width:30px;}/*Setting the width of column 2.*/_x000D_
table.fixed td:nth-of-type(3) {width:40px;}/*Setting the width of column 3.*/
_x000D_
<table class="fixed">_x000D_
    <tr>_x000D_
        <td>Veryverylongtext</td>_x000D_
        <td>Actuallythistextismuchlongeeeeeer</td>_x000D_
        <td>We should use spaces tooooooooooooo</td>_x000D_
    </tr>_x000D_
</table>
_x000D_
_x000D_
_x000D_

You need to set the table's width even in haunter's solution. Otherwise it doesn't work.
Also a new CSS3 feature that vsync suggested is: word-break:break-all;. This will break the words without spaces in them to multiple lines too. Just modify the code like this:

table.fixed { table-layout:fixed; width:90px; word-break:break-all;}

Final result

Rendered table

Protect .NET code from reverse engineering?

Well, you cannot FULLY protect your product from being cracked, but you can maximize/enhance the security levels and make it a little bit too difficult to be cracked by newbies and intermediate crackers.

But bear in mind nothing is uncrackable, only the software on server side is well protected and cannot be cracked. Anyway, to enhance the security levels in your application, you can do some simple steps to prevent some crackers "not all" from cracking your applications. These steps will make these crackers go nuts and maybe desperate:

  • Obfuscate your source code, obviously this will make your source code look like a mess and unreadable.
  • Trigger several random checking routines inside your application like every two hours, 24 hours, one day, week, etc. or maybe after every action the user take.
  • Save your released application's MD5 checksum on your server and implement a routine that can check the current file MD5 checksum with the real one on you server side and make it randomly triggered. If the MD5 checksum has been changed that means this copy has been pirated. Now you can just block it or release an update to block it, etc.
  • Try to make a routine that can check if some of your codes (functions, classes, or specific routines) are actually have been modified or altered or even removed. I call it (code integrity check).
  • Use free unknown packers to pack your application. Or, if you have the money, go for commercial solutions such as Thamida or .NET Reactor. Those applications get updated regularly and once a cracker unpack your application, you can just get a new update from those companies and once you get the new update, you just pack your program and release a new update.
  • Release updates regularly and force your customer to download the latest update.
  • Finally make your application very cheap. Don't make it too expensive. Believe me, you will get more happy customers and crackers will just leave your application, because it isn't worth their time to crack a very cheap application.

Those are just simple methods to prevent newbies and intermediate crackers from cracking your application. If you have more ideas to protect your application just don't be shy to implement them. It will just make crackers lives hard, and they will get frustrated, and eventually they will leave your application, because it's just doesn't worth their time.

Lastly, you also need to consider spending your time on coding a good and quality applications. Don't waste your time on coding complicated security layers. If a good cracker wants to crack your application he/she will do no matter what you do...

Now go and implement some toys for the crackers...

How do I get list of all tables in a database using TSQL?

SELECT * FROM information_schema.tables
where TABLE_TYPE = 'BASE TABLE'

SQL Server 2012

How to resolve git stash conflict without commit?

It seems that this may be the answer you're looking for, I haven't tried this personally yet, but it seems like it may do the trick. With this command GIT will try to apply the changes as they were before, without trying to add all of them for commit.

git stash apply --index

here is the full explanation:

http://git-scm.com/book/en/Git-Tools-Stashing

How to retrieve a single file from a specific revision in Git?

This will help you get all deleted files between commits without specifying the path, useful if there are a lot of files deleted.

git diff --name-only --diff-filter=D $commit~1 $commit | xargs git checkout $commit~1

How can I get a channel ID from YouTube?

To obtain the channel id you can do the following request which gives you the channel id and playlist id.

https://www.googleapis.com/youtube/v3/channels?part=contentDetails%2C+statistics%2Csnippet&mine=true&key={YOUR_API_KEY}

mine parameter means the current authorized user

as u said channel id is perfixed with UC+{your account id} which you get while login, you can use this one also without requesting the above url you can directly call the channel api with your google id and just prefix with UC

https://www.googleapis.com/youtube/v3/channels?part=contentDetails%2C+statistics%2Csnippet&id=UC{your account id}&key={YOUR_API_KEY}

Can you style an html radio button to look like a checkbox?

In CSS3:

input[type=radio] {content:url(mycheckbox.png)}
input[type=radio]:checked {content:url(mycheckbox-checked.png)}

In reality:

<span class=fakecheckbox><input type=radio><img src="checkbox.png" alt=""></span>

@media screen {.fakecheckbox img {display:none}}
@media print {.fakecheckbox input {display:none;}}

and you'll need Javascript to keep <img> and radios in sync (and ideally insert them there in a first place).

I've used <img>, because browsers are usually configured not to print background-image. It's better to use image than another control, because image is non-interactive and less likely to cause problems.

Customizing Bootstrap CSS template

I think the officially preferred way is now to use Less, and either dynamically override the bootstrap.css (using less.js), or recompile bootstrap.css (using Node or the Less compiler).

From the Bootstrap docs, here's how to override bootstrap.css styles dynamically:

Download the latest Less.js and include the path to it (and Bootstrap) in the <head>.

 <link rel="stylesheet/less" href="/path/to/bootstrap.less">
    <script src="/path/to/less.js"></script>

To recompile the .less files, just save them and reload your page. Less.js compiles them and stores them in local storage.

Or if you prefer to statically compile a new bootstrap.css with your custom styles (for production environments):

Install the LESS command line tool via Node and run the following command:

$ lessc ./less/bootstrap.less > bootstrap.css

Disable copy constructor

Make SymbolIndexer( const SymbolIndexer& ) private. If you're assigning to a reference, you're not copying.

How to find all the subclasses of a class given its name?

The simplest solution in general form:

def get_subclasses(cls):
    for subclass in cls.__subclasses__():
        yield from get_subclasses(subclass)
        yield subclass

And a classmethod in case you have a single class where you inherit from:

@classmethod
def get_subclasses(cls):
    for subclass in cls.__subclasses__():
        yield from subclass.get_subclasses()
        yield subclass

Why use pointers?

The need for pointers in C language is described here

The basic idea is that many limitations in the language (like using arrays, strings and modifying multiple variables in functions) could be removed by manipulating with the memory location of the data. To overcome these limitations, pointers were introduced in C.

Further, it is also seen that using pointers, you can run your code faster and save memory in cases where you are passing big data types (like a structure with many fields) to a function. Making a copy of such data types before passing would take time and would consume memory. This is another reason why programmers prefer pointers for big data types.

PS: Please refer the link provided for detailed explanation with sample code.

JavaScript CSS how to add and remove multiple CSS classes to an element

Here's a simpler method to add multiple classes via classList (supported by all modern browsers, as noted in other answers here):

div.classList.add('foo', 'bar'); // add multiple classes

From: https://developer.mozilla.org/en-US/docs/Web/API/Element/classList#Examples

If you have an array of class names to add to an element, you can use the ES6 spread operator to pass them all into classList.add() via this one-liner:

let classesToAdd = [ 'foo', 'bar', 'baz' ];
div.classList.add(...classesToAdd);

Note that not all browsers support ES6 natively yet, so as with any other ES6 answer you'll probably want to use a transpiler like Babel, or just stick with ES5 and use a solution like @LayZee's above.

What is causing ImportError: No module named pkg_resources after upgrade of Python on os X?

I realize this is not related to OSX, but on an embedded system (Beagle Bone Angstrom) I had the exact same error message. Installing the following ipk packages solved it.

opkg install python-setuptools
opkg install python-pip

Flexbox not working in Internet Explorer 11

I have tested a full layout using flexbox it contains header, footer, main body with left, center and right panels and the panels can contain menu items or footer and headers that should scroll. Pretty complex

IE11 and even IE EDGE have some problems displaying the flex content but it can be overcome. I have tested it in most browsers and it seems to work.

Some fixed i have applies are IE11 height bug, Adding height:100vh and min-height:100% to the html/body. this also helps to not have to set height on container in the dom. Also make the body/html a flex container. Otherwise IE11 will compress the view.

html,body {
    display: flex;
    flex-flow:column nowrap;
    height:100vh; /* fix IE11 */
    min-height:100%; /* fix IE11 */  
}

A fix for IE EDGE that overflows the flex container: overflow:hidden on main flex container. if you remove the overflow, IE EDGE wil push the content out of the viewport instead of containing it inside the flex main container.

main{
    flex:1 1 auto;
    overflow:hidden; /* IE EDGE overflow fix */  
}

enter image description here

You can see my testing and example on my codepen page. I remarked the important css parts with the fixes i have applied and hope someone finds it useful.

How to check whether a int is not null or empty?

public class Demo {
    private static int i;
    private static Integer j;
    private static int k = -1;

    public static void main(String[] args) {
        System.out.println(i+" "+j+" "+k);
    }
}

OutPut: 0 null -1

show dbs gives "Not Authorized to execute command" error

Copy of answer OP posted in question:

Solution

After the update from the previous edit, I looked a bit about the connection between client and server and I found out that even when mongod.exe was not running, there was still something listening on port 27017 with netstat -a

So I tried to launch the server with a random port using

[dir]mongod.exe --port 2000

Then the shell with

[dir]mongo.exe --port 2000

And this time, the server printed a message saying there is a new connection. I typed few commands and everything was working perfectly fine, I started the basic tutorial from the documentation to check if it was ok and for now it is.

AngularJS For Loop with Numbers & Ranges

I tried the following and it worked just fine for me:

<md-radio-button ng-repeat="position in formInput.arrayOfChoices.slice(0,6)" value="{{position}}">{{position}}</md-radio-button>

Angular 1.3.6

Unit testing with mockito for constructors

I have used "Pattern 2 - the "factory helper pattern"

Pattern 2 - the factory helper pattern

One case where this pattern won't work is if MyClass is final. Most of the Mockito framework doesn't play particularly well with final classes; and this includes the use of spy(). Another case is where MyClass uses getClass() somewhere, and requires the resulting value to be MyClass. This won't work, because the class of a spy is actually a Mockito-generated subclass of the original class.

In either of these cases, you'll need the slightly more robust factory helper pattern, as follows.

public class MyClass{
  static class FactoryHelper{
      Foo makeFoo( A a, B b, C c ){
          return new Foo( a, b, c );
      }
  }

  //...

  private FactoryHelper helper;
  public MyClass( X x, Y y ){
      this( x, y, new FactoryHelper());
  } 

  MyClass( X x, Y, y, FactoryHelper helper ){

      //...

      this.helper = helper;
  } 

  //...

  Foo foo = helper.makeFoo( a, b, c );
}

So, you have a special constructor, just for testing, that has an additional argument. This is used from your test class, when creating the object that you're going to test. In your test class, you mock the FactoryHelper class, as well as the object that you want to create.

@Mock private MyClass.FactoryHelper mockFactoryHelper;
@Mock private Foo mockFoo;
private MyClass toTest;

and you can use it like this

toTest = new MyClass( x, y, mockFactoryHelper ); 
when( mockFactoryHelper.makeFoo( 
  any( A.class ), any( B.class ), any( C.class )))
  .thenReturn( mockFoo ); 

Source: http://web.archive.org/web/20160322155004/http://code.google.com/p/mockito/wiki/MockingObjectCreation

Javascript switch vs. if...else if...else

Sometimes it's better to use neither. For example, in a "dispatch" situation, Javascript lets you do things in a completely different way:

function dispatch(funCode) {
  var map = {
    'explode': function() {
      prepExplosive();
      if (flammable()) issueWarning();
      doExplode();
    },

    'hibernate': function() {
      if (status() == 'sleeping') return;
      // ... I can't keep making this stuff up
    },
    // ...
  };

  var thisFun = map[funCode];
  if (thisFun) thisFun();
}

Setting up multi-way branching by creating an object has a lot of advantages. You can add and remove functionality dynamically. You can create the dispatch table from data. You can examine it programmatically. You can build the handlers with other functions.

There's the added overhead of a function call to get to the equivalent of a "case", but the advantage (when there are lots of cases) of a hash lookup to find the function for a particular key.

C# Parsing JSON array of objects

Though this is an old question, I thought I'd post my answer anyway, if that helps someone in future

 JArray array = JArray.Parse(jsonString);
 foreach (JObject obj in array.Children<JObject>())
 {
     foreach (JProperty singleProp in obj.Properties())
     {
         string name = singleProp.Name;
         string value = singleProp.Value.ToString();
         //Do something with name and value
         //System.Windows.MessageBox.Show("name is "+name+" and value is "+value);
      }
 }

This solution uses Newtonsoft library, don't forget to include using Newtonsoft.Json.Linq;

Cannot open include file with Visual Studio

You need to set the path for the preprocessor to search for these include files, if they are not in the project folder.

You can set the path in VC++ Directories, or in Additional Include Directories. Both are found in project settings.

How to write a cron that will run a script every day at midnight?

from the man page

linux$ man -S 5 crontab

   cron(8) examines cron entries once every minute.

   The time and date fields are:

          field          allowed values
          -----          --------------
          minute         0-59
          hour           0-23
          day of month   1-31
          month          1-12 (or names, see below)
          day of week    0-7 (0 or 7 is Sun, or use names)
   ...
   # run five minutes after midnight, every day
   5 0 * * *       $HOME/bin/daily.job >> $HOME/tmp/out 2>&1
   ...

It is good to note the special "nicknames" that can be used (documented in the man page), particularly "@reboot" which has no time and date alternative.

   # Run once after reboot.
   @reboot         /usr/local/sbin/run_only_once_after_reboot.sh

You can also use this trick to run your cron job multiple times per minute.

   # Run every minute at 0, 20, and 40 second intervals
   * * * * *       sleep 00; /usr/local/sbin/run_3times_per_minute.sh
   * * * * *       sleep 20; /usr/local/sbin/run_3times_per_minute.sh
   * * * * *       sleep 40; /usr/local/sbin/run_3times_per_minute.sh

To add a cron job, you can do one of three things:

  1. add a command to a user's crontab, as shown above (and from the crontab, section 5, man page).

    • edit a user's crontab as root with crontab -e -u <username>
    • or edit the current user's crontab with just crontab -e
    • You can set the editor with the EDITOR environment variable
      • env EDITOR=nano crontab -e -u <username>
      • or set the value of EDITOR for your entire shell session
        1. export EDITOR=vim
        2. crontab -e
    • Make scripts executable with chmod a+x <file>


  1. create a script/program as a cron job, and add it to the system's anacron /etc/cron.*ly directories

    • anacron /etc/cron.*ly directories:
      • /etc/cron.daily
      • /etc/cron.hourly
      • /etc/cron.monthly
      • /etc/cron.weekly
    • as in:
      • /etc/cron.daily/script_runs_daily.sh
      • chmod a+x /etc/cron.daily/script_runs_daily.sh -- make it executable
    • See also the anacron man page: man anacron
    • Make scripts executable with chmod a+x <file>
    • When do these cron.*ly script run?
      • For RHEL/CentOS 5.x, they are configured in /etc/crontab or /etc/anacrontab to run at a set time
      • RHEL/CentOS 6.x+ and Fedora 17+ Linux systems only define this in /etc/anacrontab, and define cron.hourly in /etc/cron.d/0hourly


  1. Or, One can create system crontables in /etc/cron.d.

    • The previously described crontab syntax (with additionally providing a user to execute each job as) is put into a file, and the file is dropped into the /etc/cron.d directory.
    • These are easy to manage in system packaging (e.g. RPM packages), so may usually be application specific.
    • The syntax difference is that a user must be specified for the cron job after the time/date fields and before the command to execute.
    • The files added to /etc/cron.d do not need to be executable.
    • Here is an example job that is executed as the user someuser, and the use of /bin/bash as the shell is forced.


   File: /etc/cron.d/myapp-cron
   # use /bin/bash to run commands, no matter what /etc/passwd says
   SHELL=/bin/bash
   # Execute a nightly (11:00pm) cron job to scrub application records
   00 23 * * * someuser /opt/myapp/bin/scrubrecords.php

Bundler: Command not found

For rbenv users:

$ rbenv versions
2.6.0
$ rbenv global 2.6.0
$ ruby -v
ruby 2.6.0p0
$ gem install bundler
$ rbenv rehash
$ bundle
$ rails -v
Command 'rails' not found
$ rbenv rehash
$ rails -v
Rails 4.2.11.1

Implementing multiple interfaces with Java - is there a way to delegate?

There is one way to implement multiple interface.

Just extend one interface from another or create interface that extends predefined interface Ex:

public interface PlnRow_CallBack extends OnDateSetListener {
    public void Plan_Removed();
    public BaseDB getDB();
}

now we have interface that extends another interface to use in out class just use this new interface who implements two or more interfaces

public class Calculator extends FragmentActivity implements PlnRow_CallBack {

    @Override
    public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {

    }

    @Override
    public void Plan_Removed() {

    }

    @Override
    public BaseDB getDB() {

    }
}

hope this helps

How to align an image dead center with bootstrap

You should use

<div class="row fluid-img">
  <img class="col-lg-12 col-xs-12" src="src.png">
</div>

.fluid-img {
    margin: 60px auto;
}

@media( min-width: 768px ){
        .fluid-img {
            max-width: 768px;
        }
}
@media screen and (min-width: 768px) {
        .fluid-img {
            padding-left: 0;
            padding-right: 0;
        }
}

DB2 Date format

One more solution REPLACE (CHAR(current date, ISO),'-','')

Effect of using sys.path.insert(0, path) and sys.path(append) when loading modules

I'm quite a beginner in Python and I found the answer of Anand was very good but quite complicated to me, so I try to reformulate :

1) insert and append methods are not specific to sys.path and as in other languages they add an item into a list or array and :
* append(item) add item to the end of the list,
* insert(n, item) inserts the item at the nth position in the list (0 at the beginning, 1 after the first element, etc ...).

2) As Anand said, python search the import files in each directory of the path in the order of the path, so :
* If you have no file name collisions, the order of the path has no impact,
* If you look after a function already defined in the path and you use append to add your path, you will not get your function but the predefined one.

But I think that it is better to use append and not insert to not overload the standard behaviour of Python, and use non-ambiguous names for your files and methods.

What's the difference between window.location and document.location in JavaScript?

Actually I notice a difference in chrome between both , For example if you want to do a navigation to a sandboxed frame from a child frame then you can do this just with document.location but not with window.location

How to upload file to server with HTTP POST multipart/form-data?

You can use this class:

using System.Collections.Specialized;
class Post_File
{
    public static void HttpUploadFile(string url, string file, string paramName, string contentType, NameValueCollection nvc)
    {
        string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x");
        byte[] boundarybytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n");
        byte[] boundarybytesF = System.Text.Encoding.ASCII.GetBytes("--" + boundary + "\r\n");  // the first time it itereates, you need to make sure it doesn't put too many new paragraphs down or it completely messes up poor webbrick.  


        HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(url);
        wr.Method = "POST";
        wr.KeepAlive = true;
        wr.Credentials = System.Net.CredentialCache.DefaultCredentials;
        wr.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
        var nvc2 = new NameValueCollection();
        nvc2.Add("Accepts-Language", "en-us,en;q=0.5");
        wr.Headers.Add(nvc2);
        wr.ContentType = "multipart/form-data; boundary=" + boundary;


        Stream rs = wr.GetRequestStream();

        bool firstLoop = true;
        string formdataTemplate = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}";
        foreach (string key in nvc.Keys)
        {
            if (firstLoop)
            {
                rs.Write(boundarybytesF, 0, boundarybytesF.Length);
                firstLoop = false;
            }
            else
            {
                rs.Write(boundarybytes, 0, boundarybytes.Length);
            }
            string formitem = string.Format(formdataTemplate, key, nvc[key]);
            byte[] formitembytes = System.Text.Encoding.UTF8.GetBytes(formitem);
            rs.Write(formitembytes, 0, formitembytes.Length);
        }
        rs.Write(boundarybytes, 0, boundarybytes.Length);

        string headerTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n";
        string header = string.Format(headerTemplate, paramName, new FileInfo(file).Name, contentType);
        byte[] headerbytes = System.Text.Encoding.UTF8.GetBytes(header);
        rs.Write(headerbytes, 0, headerbytes.Length);

        FileStream fileStream = new FileStream(file, FileMode.Open, FileAccess.Read);
        byte[] buffer = new byte[4096];
        int bytesRead = 0;
        while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
        {
            rs.Write(buffer, 0, bytesRead);
        }
        fileStream.Close();

        byte[] trailer = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n");
        rs.Write(trailer, 0, trailer.Length);
        rs.Close();

        WebResponse wresp = null;
        try
        {
            wresp = wr.GetResponse();
            Stream stream2 = wresp.GetResponseStream();
            StreamReader reader2 = new StreamReader(stream2);
        }
        catch (Exception ex)
        {
            if (wresp != null)
            {
                wresp.Close();
                wresp = null;
            }
        }
        finally
        {
            wr = null;
        }
    }
}

use it:

NameValueCollection nvc = new NameValueCollection();
//nvc.Add("id", "TTR");
nvc.Add("table_name", "uploadfile");
nvc.Add("commit", "uploadfile");
Post_File.HttpUploadFile("http://example/upload_file.php", @"C:\user\yourfile.docx", "uploadfile", "application/vnd.ms-excel", nvc);

example server upload_file.php:

m('File upload '.(@copy($_FILES['uploadfile']['tmp_name'],getcwd().'\\'.'/'.$_FILES['uploadfile']['name']) ? 'success' : 'failed'));
function m($msg) {
    echo '<div style="background:#f1f1f1;border:1px solid #ddd;padding:15px;font:14px;text-align:center;font-weight:bold;">';
    echo $msg;
    echo '</div>';
}

Indentation Error in Python

In Notepad++

View --->Show Symbols --->Show White Spaces and Tabs(select)

replace all tabs with spaces.

Use and meaning of "in" in an if statement?

You are used to using the javascript if, and I assume you know how it works.

in is a Pythonic way of implementing iteration. It's supposed to be easier for non-programmatic thinkers to adopt, but that can sometimes make it harder for programmatic thinkers, ironically.

When you say if x in y, you are literally saying:

"if x is in y", which assumes that y has an index. In that if statement then, each object at each index in y is checked against the condition.

Similarly,

for x in y

iterates through x's in y, where y is that indexable set of items.

Think of the if situation this way (pseudo-code):

for i in next:
    if i == "0" || i == "1":
        how_much = int(next)

It takes care of the iteration over next for you.

Happy coding!

How to add hamburger menu in bootstrap

To create icon you can use Glyphicon in Bootstrap:

<a href="#" class="btn btn-info btn-sm">
    <span class="glyphicon glyphicon-menu-hamburger"></span>
</a>

And then control size of icon in css:

.glyphicon-menu-hamburger {
  font-size: npx;
}

Connect to mysql on Amazon EC2 from a remote server

I went through all the previous answers (and answers to similar questions) without success, so here is what finally worked for me. The key step was to explicitly grant privileges on the mysql server to a local user (for the server), but with my local IP appended to it (myuser@*.*.*.*). The complete step by step solution is as follows:

  1. Comment out the bind_address line in /etc/mysql/my.cnf at the server (i.e. the EC2 Instance). I suppose bind_address=0.0.0.0 would also work, but it's not needed as others have mentioned.

  2. Add a rule (as others have mentioned too) for MYSQL to the EC2 instance's security group with port 3306 and either My IP or Anywhere as Source. Both work fine after following all the steps.

  3. Create a new user myuser with limited privileges to one particular database mydb (basically following the instructions in this Amazon tutorial):

    $EC2prompt> mysql -u root -p
    [...omitted output...]
    mysql>  CREATE USER 'myuser'@'localhost' IDENTIFIED BY 'your_strong_password';
    mysql>  GRANT ALL PRIVILEGES ON 'mydb'.* TO 'myuser'@'localhost';`
    
  4. Here's the key step, without which my local address was refused when attempting a remote connection (ERROR 1130 (HY000): Host '*.*.*.23' is not allowed to connect to this MySQL server):

    mysql> GRANT ALL PRIVILEGES ON 'mydb'.* TO 'myuser'@'*.*.*.23';
    mysql> FLUSH PRIVILEGES;`
    

    (replace '*.*.*.23' by your local IP address)

  5. For good measure, I exited mysql to the shell and restarted the msyql server:

    $EC2prompt> sudo service mysql restart

  6. After these steps, I was able to happily connect from my computer with:

    $localprompt> mysql -h myinstancename.amazonaws.com -P 3306 -u myuser -p

    (replace myinstancename.amazonaws.com by the public address of your EC2 instance)

How to detect simple geometric shapes using OpenCV

You can also use template matching to detect shapes inside an image.

Why is "cursor:pointer" effect in CSS not working

I found a solution: use :hover with cursor: pointer if nothing else helps.

How does paintComponent work?

Two things you can do here:

  1. Read Painting in AWT and Swing
  2. Use a debugger and put a breakpoint in the paintComponent method. Then travel up the stacktrace and see how provides the Graphics parameter.

Just for info, here is the stacktrace that I got from the example of code I posted at the end:

Thread [AWT-EventQueue-0] (Suspended (breakpoint at line 15 in TestPaint))  
    TestPaint.paintComponent(Graphics) line: 15 
    TestPaint(JComponent).paint(Graphics) line: 1054    
    JPanel(JComponent).paintChildren(Graphics) line: 887    
    JPanel(JComponent).paint(Graphics) line: 1063   
    JLayeredPane(JComponent).paintChildren(Graphics) line: 887  
    JLayeredPane(JComponent).paint(Graphics) line: 1063 
    JLayeredPane.paint(Graphics) line: 585  
    JRootPane(JComponent).paintChildren(Graphics) line: 887 
    JRootPane(JComponent).paintToOffscreen(Graphics, int, int, int, int, int, int) line: 5228   
    RepaintManager$PaintManager.paintDoubleBuffered(JComponent, Image, Graphics, int, int, int, int) line: 1482 
    RepaintManager$PaintManager.paint(JComponent, JComponent, Graphics, int, int, int, int) line: 1413  
    RepaintManager.paint(JComponent, JComponent, Graphics, int, int, int, int) line: 1206   
    JRootPane(JComponent).paint(Graphics) line: 1040    
    GraphicsCallback$PaintCallback.run(Component, Graphics) line: 39    
    GraphicsCallback$PaintCallback(SunGraphicsCallback).runOneComponent(Component, Rectangle, Graphics, Shape, int) line: 78    
    GraphicsCallback$PaintCallback(SunGraphicsCallback).runComponents(Component[], Graphics, int) line: 115 
    JFrame(Container).paint(Graphics) line: 1967    
    JFrame(Window).paint(Graphics) line: 3867   
    RepaintManager.paintDirtyRegions(Map<Component,Rectangle>) line: 781    
    RepaintManager.paintDirtyRegions() line: 728    
    RepaintManager.prePaintDirtyRegions() line: 677 
    RepaintManager.access$700(RepaintManager) line: 59  
    RepaintManager$ProcessingRunnable.run() line: 1621  
    InvocationEvent.dispatch() line: 251    
    EventQueue.dispatchEventImpl(AWTEvent, Object) line: 705    
    EventQueue.access$000(EventQueue, AWTEvent, Object) line: 101   
    EventQueue$3.run() line: 666    
    EventQueue$3.run() line: 664    
    AccessController.doPrivileged(PrivilegedAction<T>, AccessControlContext) line: not available [native method]    
    ProtectionDomain$1.doIntersectionPrivilege(PrivilegedAction<T>, AccessControlContext, AccessControlContext) line: 76    
    EventQueue.dispatchEvent(AWTEvent) line: 675    
    EventDispatchThread.pumpOneEventForFilters(int) line: 211   
    EventDispatchThread.pumpEventsForFilter(int, Conditional, EventFilter) line: 128    
    EventDispatchThread.pumpEventsForHierarchy(int, Conditional, Component) line: 117   
    EventDispatchThread.pumpEvents(int, Conditional) line: 113  
    EventDispatchThread.pumpEvents(Conditional) line: 105   
    EventDispatchThread.run() line: 90  

The Graphics parameter comes from here:

RepaintManager.paintDirtyRegions(Map) line: 781 

The snippet involved is the following:

Graphics g = JComponent.safelyGetGraphics(
                        dirtyComponent, dirtyComponent);
                // If the Graphics goes away, it means someone disposed of
                // the window, don't do anything.
                if (g != null) {
                    g.setClip(rect.x, rect.y, rect.width, rect.height);
                    try {
                        dirtyComponent.paint(g); // This will eventually call paintComponent()
                    } finally {
                        g.dispose();
                    }
                }

If you take a look at it, you will see that it retrieve the graphics from the JComponent itself (indirectly with javax.swing.JComponent.safelyGetGraphics(Component, Component)) which itself takes it eventually from its first "Heavyweight parent" (clipped to the component bounds) which it self takes it from its corresponding native resource.

Regarding the fact that you have to cast the Graphics to a Graphics2D, it just happens that when working with the Window Toolkit, the Graphics actually extends Graphics2D, yet you could use other Graphics which do "not have to" extends Graphics2D (it does not happen very often but AWT/Swing allows you to do that).

import java.awt.Color;
import java.awt.Graphics;

import javax.swing.JFrame;
import javax.swing.JPanel;

class TestPaint extends JPanel {

    public TestPaint() {
        setBackground(Color.WHITE);
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.drawOval(0, 0, getWidth(), getHeight());
    }

    public static void main(String[] args) {
        JFrame jFrame = new JFrame();
        jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jFrame.setSize(300, 300);
        jFrame.add(new TestPaint());
        jFrame.setVisible(true);
    }
}

Expand a div to fill the remaining width

You can use W3's CSS library that contains a class called rest that does just that:

_x000D_
_x000D_
<link rel="stylesheet" href="https://www.w3schools.com/w3css/4/w3.css">_x000D_
_x000D_
<div class="w3-row">_x000D_
  <div class="w3-col " style="width:150px">_x000D_
    <p>150px</p>_x000D_
  </div>_x000D_
  <div class="w3-rest w3-green">_x000D_
    <p>w3-rest</p>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Don't forget to link the CSS library in the page's header:

<link rel="stylesheet" href="https://www.w3schools.com/w3css/4/w3.css">

Here's the official demo: W3 School Tryit Editor

How to get current user who's accessing an ASP.NET application?

The general consensus answer above seems to have have a compatibility issue with CORS support. In order to use the HttpContext.Current.User.Identity.Name attribute you must disable anonymous authentication in order to force Windows authentication to provide the authenticated user information. Unfortunately, I believe you must have anonymous authentication enabled in order to process the pre-flight OPTIONS request in a CORS scenario.

You can get around this by leaving anonymous authentication enabled and using the HttpContext.Current.Request.LogonUserIdentity attribute instead. This will return the authenticated user information (assuming you are in an intranet scenario) even with anonymous authentication enabled. The attribute returns a WindowsUser data structure and both are defined in the System.Web namespace

        using System.Web;
        WindowsIdentity user;
        user  = HttpContext.Current.Request.LogonUserIdentity;

Android: How to stretch an image to the screen width while maintaining aspect ratio?

I've been struggling with this problem in one form or another for AGES, thank you, Thank You, THANK YOU.... :)

I just wanted to point out that you can get a generalizable solution from what Bob Lee's done by just extending View and overriding onMeasure. That way you can use this with any drawable you want, and it won't break if there's no image:

    public class CardImageView extends View {
        public CardImageView(Context context, AttributeSet attrs, int defStyle) {
            super(context, attrs, defStyle);
        }

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

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

        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            Drawable bg = getBackground();
            if (bg != null) {
                int width = MeasureSpec.getSize(widthMeasureSpec);
                int height = width * bg.getIntrinsicHeight() / bg.getIntrinsicWidth();
                setMeasuredDimension(width,height);
            }
            else {
                super.onMeasure(widthMeasureSpec, heightMeasureSpec);
            }
        }
    }

An error occurred while executing the command definition. See the inner exception for details

In my case, I messed up the connectionString property in a publish profile, trying to access the wrong database (Initial Catalog). Entity Framework then complains that the entities do not match the database, and rightly so.

How do I get the day month and year from a Windows cmd.exe script?

To get the year, month, and day you can use the %date% environment variable and the :~ operator. %date% expands to something like Thu 08/12/2010 and :~ allows you to pick up specific characters out of a variable:

set year=%date:~10,4%
set month=%date:~4,2%
set day=%date:~7,2%
set filename=%year%_%month%_%day%

Use %time% in similar fashion to get what you need from the current time.

set /? will give you more information on using special operators with variables.

How to get all properties values of a JavaScript Object (without knowing the keys)?

If you really want an array of Values, I find this cleaner than building an array with a for ... in loop.

ECMA 5.1+

function values(o) { return Object.keys(o).map(function(k){return o[k]}) }

It's worth noting that in most cases you don't really need an array of values, it will be faster to do this:

for(var k in o) something(o[k]);

This iterates over the keys of the Object o. In each iteration k is set to a key of o.

Appending a vector to a vector

While saying "the compiler can reserve", why rely on it? And what about automatic detection of move semantics? And what about all that repeating of the container name with the begins and ends?

Wouldn't you want something, you know, simpler?

(Scroll down to main for the punchline)

#include <type_traits>
#include <vector>
#include <iterator>
#include <iostream>

template<typename C,typename=void> struct can_reserve: std::false_type {};

template<typename T, typename A>
struct can_reserve<std::vector<T,A>,void>:
    std::true_type
{};

template<int n> struct secret_enum { enum class type {}; };
template<int n>
using SecretEnum = typename secret_enum<n>::type;

template<bool b, int override_num=1>
using EnableFuncIf = typename std::enable_if< b, SecretEnum<override_num> >::type;
template<bool b, int override_num=1>
using DisableFuncIf = EnableFuncIf< !b, -override_num >;

template<typename C, EnableFuncIf< can_reserve<C>::value >... >
void try_reserve( C& c, std::size_t n ) {
  c.reserve(n);
}
template<typename C, DisableFuncIf< can_reserve<C>::value >... >
void try_reserve( C& c, std::size_t ) { } // do nothing

template<typename C,typename=void>
struct has_size_method:std::false_type {};
template<typename C>
struct has_size_method<C, typename std::enable_if<std::is_same<
  decltype( std::declval<C>().size() ),
  decltype( std::declval<C>().size() )
>::value>::type>:std::true_type {};

namespace adl_aux {
  using std::begin; using std::end;
  template<typename C>
  auto adl_begin(C&&c)->decltype( begin(std::forward<C>(c)) );
  template<typename C>
  auto adl_end(C&&c)->decltype( end(std::forward<C>(c)) );
}
template<typename C>
struct iterable_traits {
    typedef decltype( adl_aux::adl_begin(std::declval<C&>()) ) iterator;
    typedef decltype( adl_aux::adl_begin(std::declval<C const&>()) ) const_iterator;
};
template<typename C> using Iterator = typename iterable_traits<C>::iterator;
template<typename C> using ConstIterator = typename iterable_traits<C>::const_iterator;
template<typename I> using IteratorCategory = typename std::iterator_traits<I>::iterator_category;

template<typename C, EnableFuncIf< has_size_method<C>::value, 1>... >
std::size_t size_at_least( C&& c ) {
    return c.size();
}

template<typename C, EnableFuncIf< !has_size_method<C>::value &&
  std::is_base_of< std::random_access_iterator_tag, IteratorCategory<Iterator<C>> >::value, 2>... >
std::size_t size_at_least( C&& c ) {
    using std::begin; using std::end;
  return end(c)-begin(c);
};
template<typename C, EnableFuncIf< !has_size_method<C>::value &&
  !std::is_base_of< std::random_access_iterator_tag, IteratorCategory<Iterator<C>> >::value, 3>... >
std::size_t size_at_least( C&& c ) {
  return 0;
};

template < typename It >
auto try_make_move_iterator(It i, std::true_type)
-> decltype(make_move_iterator(i))
{
    return make_move_iterator(i);
}
template < typename It >
It try_make_move_iterator(It i, ...)
{
    return i;
}


#include <iostream>
template<typename C1, typename C2>
C1&& append_containers( C1&& c1, C2&& c2 )
{
  using std::begin; using std::end;
  try_reserve( c1, size_at_least(c1) + size_at_least(c2) );

  using is_rvref = std::is_rvalue_reference<C2&&>;
  c1.insert( end(c1),
             try_make_move_iterator(begin(c2), is_rvref{}),
             try_make_move_iterator(end(c2), is_rvref{}) );

  return std::forward<C1>(c1);
}

struct append_infix_op {} append;
template<typename LHS>
struct append_on_right_op {
  LHS lhs;
  template<typename RHS>
  LHS&& operator=( RHS&& rhs ) {
    return append_containers( std::forward<LHS>(lhs), std::forward<RHS>(rhs) );
  }
};

template<typename LHS>
append_on_right_op<LHS> operator+( LHS&& lhs, append_infix_op ) {
  return { std::forward<LHS>(lhs) };
}
template<typename LHS,typename RHS>
typename std::remove_reference<LHS>::type operator+( append_on_right_op<LHS>&& lhs, RHS&& rhs ) {
  typename std::decay<LHS>::type retval = std::forward<LHS>(lhs.lhs);
  return append_containers( std::move(retval), std::forward<RHS>(rhs) );
}

template<typename C>
void print_container( C&& c ) {
  for( auto&& x:c )
    std::cout << x << ",";
  std::cout << "\n";
};

int main() {
  std::vector<int> a = {0,1,2};
  std::vector<int> b = {3,4,5};
  print_container(a);
  print_container(b);
  a +append= b;
  const int arr[] = {6,7,8};
  a +append= arr;
  print_container(a);
  print_container(b);
  std::vector<double> d = ( std::vector<double>{-3.14, -2, -1} +append= a );
  print_container(d);
  std::vector<double> c = std::move(d) +append+ a;
  print_container(c);
  print_container(d);
  std::vector<double> e = c +append+ std::move(a);
  print_container(e);
  print_container(a);
}

hehe.

Now with move-data-from-rhs, append-array-to-container, append forward_list-to-container, move-container-from-lhs, thanks to @DyP's help.

Note that the above does not compile in clang thanks to the EnableFunctionIf<>... technique. In clang this workaround works.

How to quickly clear a JavaScript Object?

The short answer to your question, I think, is no (you can just create a new object).

  1. In this example, I believe setting the length to 0 still leaves all of the elements for garbage collection.

  2. You could add this to Object.prototype if it's something you'd frequently use. Yes it's linear in complexity, but anything that doesn't do garbage collection later will be.

  3. This is the best solution. I know it's not related to your question - but for how long do we need to continue supporting IE6? There are many campaigns to discontinue the usage of it.

Feel free to correct me if there's anything incorrect above.

.prop() vs .attr()

attributes -> HTML

properties -> DOM

How to concatenate strings with padding in sqlite

SQLite has a printf function which does exactly that:

SELECT printf('%s-%.2d-%.4d', col1, col2, col3) FROM mytable

Checking if a number is an Integer in Java

    if((number%1)!=0)
    {
        System.out.println("not a integer");
    }
    else
    {
        System.out.println("integer");
    }

What is a Maven artifact?

Maven organizes its build in projects.

An artifact in maven is a resource generated by a maven project. Each maven project can have exactly one artifact like a jar, war, ear, etc.
The project's configuration file "pom.xml" describes how the artifact is build, how unit tests are run, etc. Commonly a software project build with maven consists of many maven-projects that build artifacts (e.g. jars) that constitute the product.
E.g.

Root-Project   // produces no artifact, simply triggers the build of the other projects
  App-Project  // The application, that uses the libraries
  Lib1-Project // A project that creates a library (jar)
  Lib2-Project // Another library
  Doc-Project  // A project that generates the user documentation from some resources

Maven artifacts are not limited to java resources. You can generate whatever resource you need. E.g. documentation, project-site, zip-archives, native-libraries, etc.

Each maven project has a unique identifier consiting of [groupId, artifactId, version]. When a maven project requires resources of another project a dependency is configured in it's pom.xml using the above-mentioned identifier. Maven then automatically resolves the dependencies when a build is triggered. The artifacts of the required projects are then loaded either from the local repository, which is a simple directory in your user's home, or from other (remote) repositories specified in you pom.xml.

How to run ~/.bash_profile in mac terminal

On MacOS: add source ~/.bash_profile to the end of ~/.zshrc. Then this profile will be in effect when you open zsh.

How to rotate the background image in the container?

Very easy method, you rotate one way, and the contents the other. Requires a square though

#element{
    background : url('someImage.jpg');
}
#element:hover{
    transform: rotate(-30deg);
}
#element:hover >*{
    transform: rotate(30deg);
}

Why does C++ compilation take so long?

A compiled language is always going to require a bigger initial overhead than an interpreted language. In addition, perhaps you didn't structure your C++ code very well. For example:

#include "BigClass.h"

class SmallClass
{
   BigClass m_bigClass;
}

Compiles a lot slower than:

class BigClass;

class SmallClass
{
   BigClass* m_bigClass;
}

CURL Command Line URL Parameters

The application/x-www-form-urlencoded Content-type header is not needed. Unless the request handler expects the parameters coming from request body. Try it out:

curl -X DELETE "http://localhost:5000/locations?id=3"

or

curl -X GET "http://localhost:5000/locations?id=3"

Create multiple threads and wait all of them to complete

If you don't want to use the Task class (for instance, in .NET 3.5) you can just start all your threads, and then add them to the list and join them in a foreach loop.

Example:

List<Thread> threads = new List<Thread>();


// Start threads
for(int i = 0; i<10; i++)
{
    int tmp = i; // Copy value for closure
    Thread t = new Thread(() => Console.WriteLine(tmp));
    t.Start;
    threads.Add(t);
}

// Await threads
foreach(Thread thread in threads)
{
    thread.Join();
}

Restart node upon changing a file

You can also try nodemon

To Install Nodemon

npm install -g nodemon

To use Nodemon

Normally we start node program like:

node server.js

But here you have to do like:

nodemon server.js

Saving an Object (Data persistence)

You can use anycache to do the job for you. It considers all the details:

  • It uses dill as backend, which extends the python pickle module to handle lambda and all the nice python features.
  • It stores different objects to different files and reloads them properly.
  • Limits cache size
  • Allows cache clearing
  • Allows sharing of objects between multiple runs
  • Allows respect of input files which influence the result

Assuming you have a function myfunc which creates the instance:

from anycache import anycache

class Company(object):
    def __init__(self, name, value):
        self.name = name
        self.value = value

@anycache(cachedir='/path/to/your/cache')    
def myfunc(name, value)
    return Company(name, value)

Anycache calls myfunc at the first time and pickles the result to a file in cachedir using an unique identifier (depending on the function name and its arguments) as filename. On any consecutive run, the pickled object is loaded. If the cachedir is preserved between python runs, the pickled object is taken from the previous python run.

For any further details see the documentation

Undo a merge by pull request?

If the pull was the last thing he did then

git reset --hard HEAD~1

Use async await with Array.map

If you map to an array of Promises, you can then resolve them all to an array of numbers. See Promise.all.

_tkinter.TclError: no display name and no $DISPLAY environment variable

I want to add an answer here that noone has explicitly stated with implementation.

This is a great resource to refer to for this failure: https://matplotlib.org/faq/usage_faq.html

In my case, using matplotlib.use did not work because it was somehow already set somewhere else. However, I was able to get beyond the error by defining an environment variable:

export MPLBACKEND=Agg

This takes care of the issue.

My error was in a CircleCI flow specifically, and this resolved the failing tests. One wierd thing was, my tests would pass when run using pytest, however would fail when using parallelism along with circleci tests split feature. However, declaring this env variable resolved the issue.

Calling a php function by onclick event

Use this html code it will surely help you

<input type="button" value="NEXT"  onclick="document.write('<?php //call a function here ex- 'fun();' ?>');" />

one limitation is that it is taking more time to run so wait for few seconds it will work

remove double quotes from Json return data using Jquery

I also had this question, but in my case I didn't want to use a regex, because my JSON value may contain quotation marks. Hopefully my answer will help others in the future.

I solved this issue by using a standard string slice to remove the first and last characters. This works for me, because I used JSON.stringify() on the textarea that produced it and as a result, I know that I'm always going to have the "s at each end of the string.

In this generalized example, response is the JSON object my AJAX returns, and key is the name of my JSON key.

response.key.slice(1, response.key.length-1)

I used it like this with a regex replace to preserve the line breaks and write the content of that key to a paragraph block in my HTML:

$('#description').html(studyData.description.slice(1, studyData.description.length-1).replace(/\\n/g, '<br/>'));

In this case, $('#description') is the paragraph tag I'm writing to. studyData is my JSON object, and description is my key with a multi-line value.

Setting Margin Properties in code

To use Thickness you need to create/change your project .NET framework platform version to 4.5. becaus this method available only in version 4.5. (Also you can just download PresentationFramework.dll and give referense to this dll, without create/change your .NET framework version to 4.5.)

But if you want to do this simple, You can use this code:

MyControl.Margin = new Padding(int left, int top, int right, int bottom);

also

MyControl.Margin = new Padding(int all);

This is simple and no needs any changes to your project

How to split a String by space

Try this one

    String str = "This is String";
    String[] splited = str.split("\\s+");

    String split_one=splited[0];
    String split_second=splited[1];
    String split_three=splited[2];

   Log.d("Splited String ", "Splited String" + split_one+split_second+split_three);

Failed to execute 'postMessage' on 'DOMWindow': https://www.youtube.com !== http://localhost:9000

Make sure you are loading from a URL such as:

https://www.youtube.com/embed/HIbAz29L-FA?modestbranding=1&playsinline=0&showinfo=0&enablejsapi=1&origin=https%3A%2F%2Fintercoin.org&widgetid=1

Note the "origin" component, as well as "enablejsapi=1". The origin must match what your domain is, and then it will be whitelisted and work.

How to compute the sum and average of elements in an array?

    var scores =[90, 98, 89, 100, 100, 86, 94];
        var sum = 0;
        var avg = 0;
        for(var i = 0; i < scores.length;i++){
  //Taking sum of all the arraylist
            sum = sum + scores[i];   
                }
  //Taking average     
             avg = sum/scores.length;        
  //this is the function to round a decimal no    
             var round = avg.toFixed();
             console.log(round);

Classpath resource not found when running as jar

Regarding to the originally error message

cannot be resolved to absolute file path because it does not reside in the file system

The following code could be helpful, to find the solution for the path problem:

Paths.get("message.txt").toAbsolutePath().toString();

With this you can determine, where the application expects the missing file. You can execute this in the main method of your application.

Simple way to understand Encapsulation and Abstraction

An example using C#

//abstraction - exposing only the relevant behavior
public interface IMakeFire
{
     void LightFire();
}

//encapsulation - hiding things that the rest of the world doesn't need to see
public class Caveman: IMakeFire
{
     //exposed information  
     public string Name {get;set;}

     // exposed but unchangeable information
     public byte Age {get; private set;}

     //internal i.e hidden object detail. This can be changed freely, the outside world
     // doesn't know about it
     private bool CanMakeFire()
     {  
         return Age >7;
     }

     //implementation of a relevant feature
     public void LightFire()
     {
        if (!CanMakeFire())
        {
           throw new UnableToLightFireException("Too young");
        }
        GatherWood();
        GetFireStone();
        //light the fire

     }

     private GatherWood() {};
     private GetFireStone();
}

public class PersonWithMatch:IMakeFire
{
      //implementation
 }

Any caveman can make a fire, because it implements the IMakeFire 'feature'. Having a group of fire makers (List) this means that both Caveman and PersonWithMatch are valid choises.

This means that

  //this method (and class) isn't coupled to a Caveman or a PersonWithMatch
  // it can work with ANY object implementing IMakeFire
  public void FireStarter(IMakeFire starter)
  {
        starter.LightFire();
    }

So you can have lots of implementors with plenty of details (properties) and behavior(methods), but in this scenario what matters is their ability to make fire. This is abstraction.

Since making a fire requires some steps (GetWood etc), these are hidden from the view as they are an internal concern of the class. The caveman has many other public behaviors which can be called by the outside world. But some details will be always hidden because are related to internal working. They're private and exist only for the object, they are never exposed. This is encapsulation

downcast and upcast

Answer 1 : Yes it called upcasting but the way you do it is not modern way. Upcasting can be performed implicitly you don't need any conversion. So just writing Employee emp = mgr; is enough for upcasting.

Answer 2 : If you create object of Manager class we can say that manager is an employee. Because class Manager : Employee depicts Is-A relationship between Employee Class and Manager Class. So we can say that every manager is an employee.

But if we create object of Employee class we can not say that this employee is manager because class Employee is a class which is not inheriting any other class. So you can not directly downcast that Employee Class object to Manager Class object.

So answer is, if you want to downcast from Employee Class object to Manager Class object, first you must have object of Manager Class first then you can upcast it and then you can downcast it.

wp-admin shows blank page, how to fix it?

All your problem is solved right now just follow this instruction:

  1. go to your themes then de activate your current theme, just put "x" in the the first letter of your theme name.

for example this is your theme folder name: "mytheme" just put "x" in the first letter like this "xmytheme" tho di activate.

  1. Then after that go back to your wp-admin panel then BOOM! wp-admin accessable.

  2. When you access your wp-admin panel or you are on your dashboard, again activate your theme again, but before that. REMOVE THE "X" letter you putted in your theme name. example: "xmytheme" just remove "x", output like this: "mytheme"

  3. then activate it in your dashboard.

hope this help!.

How to search for a string in an arraylist

 List <String> list = new ArrayList();  
           list.add("behold"); 
           list.add("bend"); 
           list.add("bet"); 
           list.add("bear"); 
           list.add("beat"); 
           list.add("become"); 
           list.add("begin");

           List <String> listClone = new ArrayList<String>(); 
           for (String string : list) {
               if(string.matches("(?i)(bea).*")){
                   listClone.add(string);
               }
           }
        System.out.println(listClone);

Using the RUN instruction in a Dockerfile with 'source' does not work

If you are using Docker 1.12 or newer, just use SHELL !

Short Answer:

general:

SHELL ["/bin/bash", "-c"] 

for python vituralenv:

SHELL ["/bin/bash", "-c", "source /usr/local/bin/virtualenvwrapper.sh"]

Long Answer:

from https://docs.docker.com/engine/reference/builder/#shell

SHELL ["executable", "parameters"]

The SHELL instruction allows the default shell used for the shell form of commands to be overridden. The default shell on Linux is ["/bin/sh", "-c"], and on Windows is ["cmd", "/S", "/C"]. The SHELL instruction must be written in JSON form in a Dockerfile.

The SHELL instruction is particularly useful on Windows where there are two commonly used and quite different native shells: cmd and powershell, as well as alternate shells available including sh.

The SHELL instruction can appear multiple times. Each SHELL instruction overrides all previous SHELL instructions, and affects all subsequent instructions. For example:

FROM microsoft/windowsservercore

# Executed as cmd /S /C echo default
RUN echo default

# Executed as cmd /S /C powershell -command Write-Host default
RUN powershell -command Write-Host default

# Executed as powershell -command Write-Host hello
SHELL ["powershell", "-command"]
RUN Write-Host hello

# Executed as cmd /S /C echo hello
SHELL ["cmd", "/S"", "/C"]
RUN echo hello

The following instructions can be affected by the SHELL instruction when the shell form of them is used in a Dockerfile: RUN, CMD and ENTRYPOINT.

The following example is a common pattern found on Windows which can be streamlined by using the SHELL instruction:

...
RUN powershell -command Execute-MyCmdlet -param1 "c:\foo.txt"
...

The command invoked by docker will be:

cmd /S /C powershell -command Execute-MyCmdlet -param1 "c:\foo.txt"

This is inefficient for two reasons. First, there is an un-necessary cmd.exe command processor (aka shell) being invoked. Second, each RUN instruction in the shell form requires an extra powershell -command prefixing the command.

To make this more efficient, one of two mechanisms can be employed. One is to use the JSON form of the RUN command such as:

...
RUN ["powershell", "-command", "Execute-MyCmdlet", "-param1 \"c:\\foo.txt\""]
...

While the JSON form is unambiguous and does not use the un-necessary cmd.exe, it does require more verbosity through double-quoting and escaping. The alternate mechanism is to use the SHELL instruction and the shell form, making a more natural syntax for Windows users, especially when combined with the escape parser directive:

# escape=`

FROM microsoft/nanoserver
SHELL ["powershell","-command"]
RUN New-Item -ItemType Directory C:\Example
ADD Execute-MyCmdlet.ps1 c:\example\
RUN c:\example\Execute-MyCmdlet -sample 'hello world'

Resulting in:

PS E:\docker\build\shell> docker build -t shell .
Sending build context to Docker daemon 4.096 kB
Step 1/5 : FROM microsoft/nanoserver
 ---> 22738ff49c6d
Step 2/5 : SHELL powershell -command
 ---> Running in 6fcdb6855ae2
 ---> 6331462d4300
Removing intermediate container 6fcdb6855ae2
Step 3/5 : RUN New-Item -ItemType Directory C:\Example
 ---> Running in d0eef8386e97


    Directory: C:\


Mode                LastWriteTime         Length Name
----                -------------         ------ ----
d-----       10/28/2016  11:26 AM                Example


 ---> 3f2fbf1395d9
Removing intermediate container d0eef8386e97
Step 4/5 : ADD Execute-MyCmdlet.ps1 c:\example\
 ---> a955b2621c31
Removing intermediate container b825593d39fc
Step 5/5 : RUN c:\example\Execute-MyCmdlet 'hello world'
 ---> Running in be6d8e63fe75
hello world
 ---> 8e559e9bf424
Removing intermediate container be6d8e63fe75
Successfully built 8e559e9bf424
PS E:\docker\build\shell>

The SHELL instruction could also be used to modify the way in which a shell operates. For example, using SHELL cmd /S /C /V:ON|OFF on Windows, delayed environment variable expansion semantics could be modified.

The SHELL instruction can also be used on Linux should an alternate shell be required such as zsh, csh, tcsh and others.

The SHELL feature was added in Docker 1.12.

How to delete shared preferences data from App in Android

Try this code:

SharedPreferences sharedPreferences = getSharedPreferences("fake", Context.MODE_PRIVATE);
SharedPreferences.Editor edit = sharedPreferences.edit();
edit.clear().commit();

can not find module "@angular/material"

Found this post: "Breaking changes" in angular 9. All modules must be imported separately. Also a fine module available there, thanks to @jeff-gilliland: https://stackoverflow.com/a/60111086/824622

How to set dialog to show in full screen?

The easiest way I found

Dialog dialog=new Dialog(this,android.R.style.Theme_Black_NoTitleBar_Fullscreen);
        dialog.setContentView(R.layout.frame_help);
        dialog.show();

Merge r brings error "'by' must specify uniquely valid columns"

Rather give names of the column on which you want to merge:

exporttab <- merge(x=dwd_nogap, y=dwd_gap, by.x='x1', by.y='x2', fill=-9999)

Loop through each cell in a range of cells when given a Range object

I'm resurrecting the dead here, but because a range can be defined as "A:A", using a for each loop ends up with a potential infinite loop. The solution, as far as I know, is to use the Do Until loop.

Do Until Selection.Value = ""
  Rem Do things here...
Loop