Programs & Examples On #Redirectstandardoutput

UTF-8 output from PowerShell

Not an expert on encoding, but after reading these...

... it seems fairly clear that the $OutputEncoding variable only affects data piped to native applications.

If sending to a file from withing PowerShell, the encoding can be controlled by the -encoding parameter on the out-file cmdlet e.g.

write-output "hello" | out-file "enctest.txt" -encoding utf8

Nothing else you can do on the PowerShell front then, but the following post may well help you:.

Redirection of standard and error output appending to the same log file

Maybe it is not quite as elegant, but the following might also work. I suspect asynchronously this would not be a good solution.

$p = Start-Process myjob.bat -redirectstandardoutput $logtempfile -redirecterroroutput $logtempfile -wait
add-content $logfile (get-content $logtempfile)

Capturing standard out and error with Start-Process

That's how Start-Process was designed for some reason. Here's a way to get it without sending to file:

$pinfo = New-Object System.Diagnostics.ProcessStartInfo
$pinfo.FileName = "ping.exe"
$pinfo.RedirectStandardError = $true
$pinfo.RedirectStandardOutput = $true
$pinfo.UseShellExecute = $false
$pinfo.Arguments = "localhost"
$p = New-Object System.Diagnostics.Process
$p.StartInfo = $pinfo
$p.Start() | Out-Null
$p.WaitForExit()
$stdout = $p.StandardOutput.ReadToEnd()
$stderr = $p.StandardError.ReadToEnd()
Write-Host "stdout: $stdout"
Write-Host "stderr: $stderr"
Write-Host "exit code: " + $p.ExitCode

Hide console window from Process.Start C#

I had a similar issue when attempting to start a process without showing the console window. I tested with several different combinations of property values until I found one that exhibited the behavior I wanted.

Here is a page detailing why the UseShellExecute property must be set to false.
http://msdn.microsoft.com/en-us/library/system.diagnostics.processstartinfo.createnowindow.aspx

Under Remarks section on page:

If the UseShellExecute property is true or the UserName and Password properties are not null, the CreateNoWindow property value is ignored and a new window is created.

ProcessStartInfo startInfo = new ProcessStartInfo();
startInfo.FileName = fullPath;
startInfo.Arguments = args;
startInfo.RedirectStandardOutput = true;
startInfo.RedirectStandardError = true;
startInfo.UseShellExecute = false;
startInfo.CreateNoWindow = true;

Process processTemp = new Process();
processTemp.StartInfo = startInfo;
processTemp.EnableRaisingEvents = true;
try
{
    processTemp.Start();
}
catch (Exception e)
{
    throw;
}

How to start a Process as administrator mode in C#

First of all you need to include in your project

using System.Diagnostics;

After that you could write a general method that you could use for different .exe files that you want to use. It would be like below:

public void ExecuteAsAdmin(string fileName)
{
    Process proc = new Process();
    proc.StartInfo.FileName = fileName;
    proc.StartInfo.UseShellExecute = true;
    proc.StartInfo.Verb = "runas";
    proc.Start();
}

If you want to for example execute notepad.exe then all you do is you call this method:

ExecuteAsAdmin("notepad.exe");

Error in Process.Start() -- The system cannot find the file specified

I had the same problem, but none of the solutions worked for me, because the message The system cannot find the file specified can be misleading in some special cases.

In my case, I use Notepad++ in combination with the registry redirect for notepad.exe. Unfortunately my path to Notepad++ in the registry was wrong.

So in fact the message The system cannot find the file specified was telling me, that it cannot find the application (Notepad++) associated with the file type(*.txt), not the file itself.

How can I Convert HTML to Text in C#?

I don't know C#, but there is a fairly small & easy to read python html2txt script here: http://www.aaronsw.com/2002/html2text/

How to execute an .SQL script file using c#

This Works on Framework 4.0 or Higher. Supports "GO". Also show the error message, line, and sql command.

using System.Data.SqlClient;

        private bool runSqlScriptFile(string pathStoreProceduresFile, string connectionString)
    {
        try
        {
            string script = File.ReadAllText(pathStoreProceduresFile);

            // split script on GO command
            System.Collections.Generic.IEnumerable<string> commandStrings = Regex.Split(script, @"^\s*GO\s*$",
                                     RegexOptions.Multiline | RegexOptions.IgnoreCase);
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                foreach (string commandString in commandStrings)
                {
                    if (commandString.Trim() != "")
                    {
                        using (var command = new SqlCommand(commandString, connection))
                        {
                        try
                        {
                            command.ExecuteNonQuery();
                        }
                        catch (SqlException ex)
                        {
                            string spError = commandString.Length > 100 ? commandString.Substring(0, 100) + " ...\n..." : commandString;
                            MessageBox.Show(string.Format("Please check the SqlServer script.\nFile: {0} \nLine: {1} \nError: {2} \nSQL Command: \n{3}", pathStoreProceduresFile, ex.LineNumber, ex.Message, spError), "Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                            return false;
                        }
                    }
                    }
                }
                connection.Close();
            }
        return true;
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message, "Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            return false;
        }
    }

How to execute a .bat file from a C# windows form app?

For the problem you're having about the batch file asking the user if the destination is a folder or file, if you know the answer in advance, you can do as such:

If destination is a file: echo f | [batch file path]

If folder: echo d | [batch file path]

It will essentially just pipe the letter after "echo" to the input of the batch file.

How to spawn a process and capture its STDOUT in .NET?

I needed to capture both stdout and stderr and have it timeout if the process didn't exit when expected. I came up with this:

Process process = new Process();
StringBuilder outputStringBuilder = new StringBuilder();

try
{
process.StartInfo.FileName = exeFileName;
process.StartInfo.WorkingDirectory = args.ExeDirectory;
process.StartInfo.Arguments = args;
process.StartInfo.RedirectStandardError = true;
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
process.StartInfo.CreateNoWindow = true;
process.StartInfo.UseShellExecute = false;
process.EnableRaisingEvents = false;
process.OutputDataReceived += (sender, eventArgs) => outputStringBuilder.AppendLine(eventArgs.Data);
process.ErrorDataReceived += (sender, eventArgs) => outputStringBuilder.AppendLine(eventArgs.Data);
process.Start();
process.BeginOutputReadLine();
process.BeginErrorReadLine();
var processExited = process.WaitForExit(PROCESS_TIMEOUT);

if (processExited == false) // we timed out...
{
    process.Kill();
    throw new Exception("ERROR: Process took too long to finish");
}
else if (process.ExitCode != 0)
{
    var output = outputStringBuilder.ToString();
    var prefixMessage = "";

    throw new Exception("Process exited with non-zero exit code of: " + process.ExitCode + Environment.NewLine + 
    "Output from process: " + outputStringBuilder.ToString());
}
}
finally
{                
process.Close();
}

I am piping the stdout and stderr into the same string, but you could keep it separate if needed. It uses events, so it should handle them as they come (I believe). I have run this successfully, and will be volume testing it soon.

ProcessStartInfo hanging on "WaitForExit"? Why?

Mark Byers' answer is excellent, but I would just add the following:

The OutputDataReceived and ErrorDataReceived delegates need to be removed before the outputWaitHandle and errorWaitHandle get disposed. If the process continues to output data after the timeout has been exceeded and then terminates, the outputWaitHandle and errorWaitHandle variables will be accessed after being disposed.

(FYI I had to add this caveat as an answer as I couldn't comment on his post.)

difference between primary key and unique key

Difference between Primary Key and Unique Key

+-----------------------------------------+-----------------------------------------------+
|                Primary Key              |                    Unique Key                 |
+-----------------------------------------+-----------------------------------------------+
| Primary Key can't accept null values.   | Unique key can accept only one null value.    |
+-----------------------------------------+-----------------------------------------------+
| By default, Primary key is clustered    | By default, Unique key is a unique            |
| index and data in the database table is | non-clustered index.                          |
| physically organized in the sequence of |                                               |
| clustered index.                        |                                               |
+-----------------------------------------+-----------------------------------------------+
| We can have only one Primary key in a   | We can have more than one unique key in a     |
| table.                                  | table.                                        |
+-----------------------------------------+-----------------------------------------------+
| Primary key can be made foreign key     | In SQL Server, Unique key can be made foreign |
| into another table.                     | key into another table.                       |
+-----------------------------------------+-----------------------------------------------+

You can find detailed information from:
http://www.dotnet-tricks.com/Tutorial/sqlserver/V2bS260912-Difference-between-Primary-Key-and-Unique-Key.html

Bootstrap: Position of dropdown menu relative to navbar item

If you wants to center the dropdown, this is the solution.

<ul class="dropdown-menu" style="right:auto; left: auto;">

Checking if float is an integer

stdlib float modf (float x, float *ipart) splits into two parts, check if return value (fractional part) == 0.

How to get the mysql table columns data type?

ResultSet rs = Sstatement.executeQuery("SELECT * FROM Table Name");

ResultSetMetaData rsMetaData = rs.getMetaData();

int numberOfColumns = rsMetaData.getColumnCount();
System.out.println("resultSet MetaData column Count=" + numberOfColumns);

for (int i = 1; i <= numberOfColumns; i++) {
 System.out.println("column number " + i);

  System.out.println(rsMetaData.getColumnTypeName(i));
}

Debug assertion failed. C++ vector subscript out of range

Regardless of how do you index the pushbacks your vector contains 10 elements indexed from 0 (0, 1, ..., 9). So in your second loop v[j] is invalid, when j is 10.

This will fix the error:

for(int j = 9;j >= 0;--j)
{
    cout << v[j];
}

In general it's better to think about indexes as 0 based, so I suggest you change also your first loop to this:

for(int i = 0;i < 10;++i)
{
    v.push_back(i);
}

Also, to access the elements of a container, the idiomatic approach is to use iterators (in this case: a reverse iterator):

for (vector<int>::reverse_iterator i = v.rbegin(); i != v.rend(); ++i)
{
    std::cout << *i << std::endl;
}

Curl error: Operation timed out

Your curl gets timed out. Probably the url you are trying that requires more that 30 seconds.

If you are running the script through browser, then set the set_time_limit to zero for infinite seconds.

set_time_limit(0);

Increase the curl's operation time limit using this option CURLOPT_TIMEOUT

curl_setopt($ch, CURLOPT_TIMEOUT,500); // 500 seconds

It can also happen for infinite redirection from the server. To halt this try to run the script with follow location disabled.

curl_setopt($ch, CURLOPT_FOLLOWLOCATION, false);

Saving the PuTTY session logging

To set permanent PuTTY session parameters do:

  1. Create sessions in PuTTY. Name it as "MyskinPROD"

  2. Configure the path for this session to point to "C:\dir\&Y&M&D&T_&H_putty.log".

  3. Create a Windows "Shortcut" to C:...\Putty.exe.

  4. Open "Shortcut" Properties and append "Target" line with parameters as shown below:

    "C:\Program Files (x86)\UTL\putty.exe" -ssh -load MyskinPROD user@ServerIP -pw password
    

Now, your PuTTY shortcut will bring in the "MyskinPROD" configuration every time you open the shortcut.

Check the screenshots and details on how I did it in my environment:

http://www.evernote.com/shard/s184/sh/93ebf08f-fde2-4dad-bccf-961c98fb614b/983d2ff8f2d1e6184318825d68b0b829

How to create my json string by using C#?

To convert any object or object list into JSON, we have to use the function JsonConvert.SerializeObject.

The below code demonstrates the use of JSON in an ASP.NET environment:

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using Newtonsoft.Json;
using System.Collections.Generic;

namespace JSONFromCS
{
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e1)
        {
            List<Employee> eList = new List<Employee>();
            Employee e = new Employee();
            e.Name = "Minal";
            e.Age = 24;

            eList.Add(e);

            e = new Employee();
            e.Name = "Santosh";
            e.Age = 24;

            eList.Add(e);

            string ans = JsonConvert.SerializeObject(eList, Formatting.Indented);

            string script = "var employeeList = {\"Employee\": " + ans+"};";
            script += "for(i = 0;i<employeeList.Employee.length;i++)";
            script += "{";
            script += "alert ('Name : ='+employeeList.Employee[i].Name+' 
            Age : = '+employeeList.Employee[i].Age);";
            script += "}";

            ClientScriptManager cs = Page.ClientScript;
            cs.RegisterStartupScript(Page.GetType(), "JSON", script, true);
        }
    }
    public class Employee
    {
        public string Name;
        public int Age;
    }
}  

After running this program, you will get two alerts

In the above example, we have created a list of Employee object and passed it to function "JsonConvert.SerializeObject". This function (JSON library) will convert the object list into JSON format. The actual format of JSON can be viewed in the below code snippet:

{ "Maths" : [ {"Name"     : "Minal",        // First element
                             "Marks"     : 84,
                             "age"       : 23 },
                             {
                             "Name"      : "Santosh",    // Second element
                             "Marks"     : 91,
                             "age"       : 24 }
                           ],                       
              "Science" :  [ 
                             {
                             "Name"      : "Sahoo",     // First Element
                             "Marks"     : 74,
                             "age"       : 27 }, 
                             {                           
                             "Name"      : "Santosh",    // Second Element
                             "Marks"     : 78,
                             "age"       : 41 }
                           ] 
            } 

Syntax:

  • {} - acts as 'containers'

  • [] - holds arrays

  • : - Names and values are separated by a colon

  • , - Array elements are separated by commas

This code is meant for intermediate programmers, who want to use C# 2.0 to create JSON and use in ASPX pages.

You can create JSON from JavaScript end, but what would you do to convert the list of object into equivalent JSON string from C#. That's why I have written this article.

In C# 3.5, there is an inbuilt class used to create JSON named JavaScriptSerializer.

The following code demonstrates how to use that class to convert into JSON in C#3.5.

JavaScriptSerializer serializer = new JavaScriptSerializer()
return serializer.Serialize(YOURLIST);   

So, try to create a List of arrays with Questions and then serialize this list into JSON

How to wait for a process to terminate to execute another process in batch file

I liked the "START /W" answer, though for my situation I found something even more basic. My processes were console applications. And in my ignorance I thought I would need something special in BAT syntax to make sure that the 1st one completed before the 2nd one started. However BAT appears to make a distinction between console apps and windows apps, and it executes them a little differently. The OP shows that window apps will get launched as an asynchronous call from BAT. But for console apps, that are invoked synchronously, inside the same command window as the BAT itself is running in.

For me it was actually better not to use "START /W", because everything could run inside one command window. The annoying thing about "START /W" is that it will spawn a new command window to execute your console application in.

presentViewController and displaying navigation bar

If you didn't set the modalPresentationStyle property (like to UIModalPresentationFormSheet), the navigation bar will be displayed always. To ensure, always do

[[self.navigationController topViewController] presentViewController:vieController 
                                                            animated:YES 
                                                          completion:nil];

This will show the navigation bar always.

Something better than .NET Reflector?

Instead of using the autoupdater, we just set the properties of the EXE file to read-only. That way it doesn’t delete the file.

Another git process seems to be running in this repository

It is similar to above methods but in my case I had several of those

.git/refs/heads/<branch_name>.lock

and was able to remove all at once by this way

find -name "*.lock" -exec xargs rm {} \;

Delete all files in directory (but not directory) - one liner solution

public class DeleteFile {
    public static void main(String[] args) {
        String path="D:\test"; 
        File file = new File(path);
        File[] files = file.listFiles(); 
        for (File f:files) 
        {if (f.isFile() && f.exists) 
            { f.delete();
system.out.println("successfully deleted");
            }else{
system.out.println("cant delete a file due to open or error");
} }  }}

How to get the last five characters of a string using Substring() in C#?

string input = "OneTwoThree";
(if input.length >5)
{
string str=input.substring(input.length-5,5);
}

How to prevent robots from automatically filling up a form?

The best solution I've found to avoid getting spammed by bots is using a very trivial question or field on your form.

Try adding a field like these :

  • Copy "hello" in the box aside
  • 1+1 = ?
  • Copy the website name in the box

These tricks require the user to understant what must be input on the form, thus making it much harder to be the target of massive bot form-filling.

EDIT

The backside of this method, as you stated in your question, is the extra step for the user to validate its form. But, in my opinion, it is far simpler than a captcha and the overhead when filling the form is not more than 5 seconds, which seems acceptable from the user point of view.

SQL query for finding records where count > 1

Use the HAVING clause and GROUP By the fields that make the row unique

The below will find

all users that have more than one payment per day with the same account number

SELECT 
 user_id ,
 COUNT(*) count
FROM 
 PAYMENT
GROUP BY
 account,
 user_id ,
 date
HAVING
COUNT(*) > 1

Update If you want to only include those that have a distinct ZIP you can get a distinct set first and then perform you HAVING/GROUP BY

 SELECT 
    user_id,
    account_no , 
    date,
        COUNT(*)
 FROM
    (SELECT DISTINCT
            user_id,
            account_no , 
            zip, 
            date
         FROM
            payment 
    
        ) 
        payment
 GROUP BY
    
    user_id,
    account_no , 
    
    date
HAVING COUNT(*) > 1

How to determine whether an object has a given property in JavaScript

If you want to know if the object physically contains the property @gnarf's answer using hasOwnProperty will do the work.

If you're want to know if the property exists anywhere, either on the object itself or up in the prototype chain, you can use the in operator.

if ('prop' in obj) {
  // ...
}

Eg.:

var obj = {};

'toString' in obj == true; // inherited from Object.prototype
obj.hasOwnProperty('toString') == false; // doesn't contains it physically

PHP Unset Array value effect on other indexes

They are as they were. That one key is JUST DELETED

How to convert JSONObjects to JSONArray?

To deserialize the response need to use HashMap:

String resp = ...//String output from your source

Gson gson = new GsonBuilder().create();
gson.fromJson(resp,TheResponse.class);

class TheResponse{
 HashMap<String,Song> songs;
}

class Song{
  String id;
  String pos;
}

How to use export with Python on Linux

Kind of a hack because it's not really python doing anything special here, but if you run the export command in the same sub-shell, you will probably get the result you want.

import os

cmd = "export MY_DATA='1234'; echo $MY_DATA" # or whatever command
os.system(cmd)

webpack command not working

npm i webpack -g

installs webpack globally on your system, that makes it available in terminal window.

R solve:system is exactly singular

Lapack is a Linear Algebra package which is used by R (actually it's used everywhere) underneath solve(), dgesv spits this kind of error when the matrix you passed as a parameter is singular.

As an addendum: dgesv performs LU decomposition, which, when using your matrix, forces a division by 0, since this is ill-defined, it throws this error. This only happens when matrix is singular or when it's singular on your machine (due to approximation you can have a really small number be considered 0)

I'd suggest you check its determinant if the matrix you're using contains mostly integers and is not big. If it's big, then take a look at this link.

HTML text-overflow ellipsis detection

This sample show tooltip on cell table with text truncated. Is dynamic based on table width:

$.expr[':'].truncated = function (obj) {
    var element = $(obj);

    return (element[0].scrollHeight > (element.innerHeight() + 1)) || (element[0].scrollWidth > (element.innerWidth() + 1));
};

$(document).ready(function () {
    $("td").mouseenter(function () {
        var cella = $(this);
        var isTruncated = cella.filter(":truncated").length > 0;
        if (isTruncated) 
            cella.attr("title", cella.text());
        else 
            cella.attr("title", null);
    });
});

Demo: https://jsfiddle.net/t4qs3tqs/

It works on all version of jQuery

How can I convert bigint (UNIX timestamp) to datetime in SQL Server?

Solution can be the following:

DECLARE @UnixTimeStamp bigint = 1564646400000 /*2019-08-01 11:00 AM*/

DECLARE @LocalTimeOffset bigint = DATEDIFF(MILLISECOND, GETDATE(), GETUTCDATE());
DECLARE @AdjustedTimeStamp bigint = @UnixTimeStamp - @LocalTimeOffset;
SELECT [DateTime] = DATEADD(SECOND, @AdjustedTimeStamp % 1000, DATEADD(SECOND, @AdjustedTimeStamp / 1000, '19700101'));

Change the fill color of a cell based on a selection from a Drop Down List in an adjacent cell

This works with me :
1- select the cells which shall be be affected by the drop down list .
2- home -> conditional formating -> new rule .
3- format only cells that contain .
4- in format only cells with ... select specific text , in formatting rule "= select Elementary from your drop down list"
if drop list in another sheet then when select Elementary we see "=Sheet3!$F$2" in the new rule , with your own sheet and cell number.
5- format -> fill -> select color -> ok.
6-ok .
do the same for each element in drop down list then you will see the magic !

Passing arguments to C# generic new() of templated type

You need to add where T: new() to let the compiler know that T is guaranteed to provide a default constructor.

public static string GetAllItems<T>(...) where T: new()

Add image to layout in ruby on rails

It's working for me:

<%= image_tag( root_url + "images/rss.jpg", size: "50x50", :alt => "rss feed") -%>

How do we determine the number of days for a given month in python

Just for the sake of academic interest, I did it this way...

(dt.replace(month = dt.month % 12 +1, day = 1)-timedelta(days=1)).day

How to save/restore serializable object to/from file?

You'll need to serialize to something: that is, pick binary, or xml (for default serializers) or write custom serialization code to serialize to some other text form.

Once you've picked that, your serialization will (normally) call a Stream that is writing to some kind of file.

So, with your code, if I were using XML Serialization:

var path = @"C:\Test\myserializationtest.xml";
using(FileStream fs = new FileStream(path, FileMode.Create))
{
    XmlSerializer xSer = new XmlSerializer(typeof(SomeClass));

    xSer.Serialize(fs, serializableObject);
}

Then, to deserialize:

using(FileStream fs = new FileStream(path, FileMode.Open)) //double check that...
{
    XmlSerializer _xSer = new XmlSerializer(typeof(SomeClass));

    var myObject = _xSer.Deserialize(fs);
}

NOTE: This code hasn't been compiled, let alone run- there may be some errors. Also, this assumes completely out-of-the-box serialization/deserialization. If you need custom behavior, you'll need to do additional work.

Change button background color using swift language

Try this, you need to add the 255 like so:

button.backgroundColor = UIColor(red: 102/255, green: 250/255, blue: 51/255, alpha: 0.5)

Eclipse add Tomcat 7 blank server name

I faced the same issue, and I changed the workspace to new location, and it worked. I hope this helps :)

Checkbox Check Event Listener

Short answer: Use the change event. Here's a couple of practical examples. Since I misread the question, I'll include jQuery examples along with plain JavaScript. You're not gaining much, if anything, by using jQuery though.

Single checkbox

Using querySelector.

_x000D_
_x000D_
var checkbox = document.querySelector("input[name=checkbox]");

checkbox.addEventListener('change', function() {
  if (this.checked) {
    console.log("Checkbox is checked..");
  } else {
    console.log("Checkbox is not checked..");
  }
});
_x000D_
<input type="checkbox" name="checkbox" />
_x000D_
_x000D_
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Single checkbox with jQuery

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$('input[name=checkbox]').change(function() {
  if ($(this).is(':checked')) {
    console.log("Checkbox is checked..")
  } else {
    console.log("Checkbox is not checked..")
  }
});
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<input type="checkbox" name="checkbox" />
_x000D_
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Multiple checkboxes

Here's an example of a list of checkboxes. To select multiple elements we use querySelectorAll instead of querySelector. Then use Array.filter and Array.map to extract checked values.

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// Select all checkboxes with the name 'settings' using querySelectorAll.
var checkboxes = document.querySelectorAll("input[type=checkbox][name=settings]");
let enabledSettings = []

/*
For IE11 support, replace arrow functions with normal functions and
use a polyfill for Array.forEach:
https://vanillajstoolkit.com/polyfills/arrayforeach/
*/

// Use Array.forEach to add an event listener to each checkbox.
checkboxes.forEach(function(checkbox) {
  checkbox.addEventListener('change', function() {
    enabledSettings = 
      Array.from(checkboxes) // Convert checkboxes to an array to use filter and map.
      .filter(i => i.checked) // Use Array.filter to remove unchecked checkboxes.
      .map(i => i.value) // Use Array.map to extract only the checkbox values from the array of objects.
      
    console.log(enabledSettings)
  })
});
_x000D_
<label>
   <input type="checkbox" name="settings" value="forcefield">
   Enable forcefield
</label>
<label>
  <input type="checkbox" name="settings" value="invisibilitycloak">
  Enable invisibility cloak
</label>
<label>
  <input type="checkbox" name="settings" value="warpspeed">
  Enable warp speed
</label>
_x000D_
_x000D_
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Multiple checkboxes with jQuery

_x000D_
_x000D_
let checkboxes = $("input[type=checkbox][name=settings]")
let enabledSettings = [];

// Attach a change event handler to the checkboxes.
checkboxes.change(function() {
  enabledSettings = checkboxes
    .filter(":checked") // Filter out unchecked boxes.
    .map(function() { // Extract values using jQuery map.
      return this.value;
    }) 
    .get() // Get array.
    
  console.log(enabledSettings);
});
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<label>
   <input type="checkbox" name="settings" value="forcefield">
   Enable forcefield
</label>
<label>
  <input type="checkbox" name="settings" value="invisibilitycloak">
  Enable invisibility cloak
</label>
<label>
  <input type="checkbox" name="settings" value="warpspeed">
  Enable warp speed
</label>
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How to post data in PHP using file_get_contents?

Sending an HTTP POST request using file_get_contents is not that hard, actually : as you guessed, you have to use the $context parameter.


There's an example given in the PHP manual, at this page : HTTP context options (quoting) :

$postdata = http_build_query(
    array(
        'var1' => 'some content',
        'var2' => 'doh'
    )
);

$opts = array('http' =>
    array(
        'method'  => 'POST',
        'header'  => 'Content-Type: application/x-www-form-urlencoded',
        'content' => $postdata
    )
);

$context  = stream_context_create($opts);

$result = file_get_contents('http://example.com/submit.php', false, $context);

Basically, you have to create a stream, with the right options (there is a full list on that page), and use it as the third parameter to file_get_contents -- nothing more ;-)


As a sidenote : generally speaking, to send HTTP POST requests, we tend to use curl, which provides a lot of options an all -- but streams are one of the nice things of PHP that nobody knows about... too bad...

Excel VBA - How to Redim a 2D array?

A small update to what @control freak and @skatun wrote previously (sorry I don't have enough reputation to just make a comment). I used skatun's code and it worked well for me except that it was creating a larger array than what I needed. Therefore, I changed:

ReDim aPreservedArray(nNewFirstUBound, nNewLastUBound)

to:

ReDim aPreservedArray(LBound(aArrayToPreserve, 1) To nNewFirstUBound, LBound(aArrayToPreserve, 2) To nNewLastUBound)

This will maintain whatever the original array's lower bounds were (either 0, 1, or whatever; the original code assumes 0) for both dimensions.

How to return a boolean method in java?

You're allowed to have more than one return statement, so it's legal to write

if (some_condition) {
  return true;
}
return false;

It's also unnecessary to compare boolean values to true or false, so you can write

if (verifyPwd())  {
  // do_task
}

Edit: Sometimes you can't return early because there's more work to be done. In that case you can declare a boolean variable and set it appropriately inside the conditional blocks.

boolean success = true;

if (some_condition) {
  // Handle the condition.
  success = false;
} else if (some_other_condition) {
  // Handle the other condition.
  success = false;
}
if (another_condition) {
  // Handle the third condition.
}

// Do some more critical things.

return success;

Where is `%p` useful with printf?

x is Unsigned hexadecimal integer ( 32 Bit )

p is Pointer address

See printf on the C++ Reference. Even if both of them would write the same, I would use %p to print a pointer.

Measure execution time for a Java method

You can take timestamp snapshots before and after, then repeat the experiments several times to average to results. There are also profilers that can do this for you.


From "Java Platform Performance: Strategies and Tactics" book:

With System.currentTimeMillis()

class TimeTest1 {
   public static void main(String[] args) {

      long startTime = System.currentTimeMillis();

      long total = 0;
      for (int i = 0; i < 10000000; i++) {
         total += i;
      }

      long stopTime = System.currentTimeMillis();
      long elapsedTime = stopTime - startTime;
      System.out.println(elapsedTime);
   }
}

With a StopWatch class

You can use this StopWatch class, and call start() and stop before and after the method.

class TimeTest2 {
   public static void main(String[] args) {

      Stopwatch timer = new Stopwatch().start();

      long total = 0;
      for (int i = 0; i < 10000000; i++) {
         total += i;
      }

      timer.stop();
      System.out.println(timer.getElapsedTime());
   }
}

See here (archived).


NetBeans Profiler:

Application Performance Application

Performance profiles method-level CPU performance (execution time). You can choose to profile the entire application or a part of the application.

See here.

Multiple Updates in MySQL

UPDATE `your_table` SET 

`something` = IF(`id`="1","new_value1",`something`), `smth2` = IF(`id`="1", "nv1",`smth2`),
`something` = IF(`id`="2","new_value2",`something`), `smth2` = IF(`id`="2", "nv2",`smth2`),
`something` = IF(`id`="4","new_value3",`something`), `smth2` = IF(`id`="4", "nv3",`smth2`),
`something` = IF(`id`="6","new_value4",`something`), `smth2` = IF(`id`="6", "nv4",`smth2`),
`something` = IF(`id`="3","new_value5",`something`), `smth2` = IF(`id`="3", "nv5",`smth2`),
`something` = IF(`id`="5","new_value6",`something`), `smth2` = IF(`id`="5", "nv6",`smth2`) 

// You just building it in php like

$q = 'UPDATE `your_table` SET ';

foreach($data as $dat){

  $q .= '

       `something` = IF(`id`="'.$dat->id.'","'.$dat->value.'",`something`), 
       `smth2` = IF(`id`="'.$dat->id.'", "'.$dat->value2.'",`smth2`),';

}

$q = substr($q,0,-1);

So you can update hole table with one query

Remove leading and trailing spaces?

Should be noted that strip() method would trim any leading and trailing whitespace characters from the string (if there is no passed-in argument). If you want to trim space character(s), while keeping the others (like newline), this answer might be helpful:

sample = '  some string\n'
sample_modified = sample.strip(' ')

print(sample_modified)  # will print 'some string\n'

strip([chars]): You can pass in optional characters to strip([chars]) method. Python will look for occurrences of these characters and trim the given string accordingly.

How to display an error message in an ASP.NET Web Application

The errors in ASP.Net are saved on the Server.GetLastError property,

Or i would put a label on the asp.net page for displaying the error.

try
{
    do something
}
catch (YourException ex)
{
    errorLabel.Text = ex.Message;
    errorLabel.Visible = true;
}

How can I get the height and width of an uiimage?

Some of the anwsers above, don't work well when rotating device.

Try:

CGRect imageContent = self.myUIImage.bounds;
CGFloat imageWidth = imageContent.size.width;
CGFloat imageHeight = imageContent.size.height;

How to pass values between Fragments

You can achieve your goal by ViewModel and Live Data which is cleared by Arnav Rao. Now I put an example to clear it more neatly.

First, the assumed ViewModel is named SharedViewModel.java.

public class SharedViewModel extends ViewModel {
    private final MutableLiveData<Item> selected = new MutableLiveData<Item>();

    public void select(Item item) {
        selected.setValue(item);
    }
    public LiveData<Item> getSelected() {
        return selected;
    }
}

Then the source fragment is the MasterFragment.java from where we want to send a data.

public class MasterFragment extends Fragment {
    private SharedViewModel model;

    public void onViewCreated(@NonNull View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        model = new ViewModelProvider(requireActivity()).get(SharedViewModel.class);
        itemSelector.setOnClickListener(item -> {

            // Data is sent

            model.select(item);
        });
    }
}

And finally the destination fragment is the DetailFragment.java to where we want to receive the data.

public class DetailFragment extends Fragment {

    public void onViewCreated(@NonNull View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        SharedViewModel model = new ViewModelProvider(requireActivity()).get(SharedViewModel.class);
        model.getSelected().observe(getViewLifecycleOwner(), { item ->

           // Data is received 

        });
    }
}

phpmyadmin "Not Found" after install on Apache, Ubuntu

sudo ln -s /etc/phpmyadmin/apache.conf /etc/apache2/conf-available/phpmyadmin.conf

sudo ln -s /usr/share/phpmyadmin /var/www/html/phpmyadmin

sudo service apache2 restart

Run above commands issue will be resolved.

Generate a random letter in Python

import random
def guess_letter():
    return random.choice('abcdefghijklmnopqrstuvwxyz')

Inputting a default image in case the src attribute of an html <img> is not valid?

<style type="text/css">
img {
   background-image: url('/images/default.png')
}
</style>

Be sure to enter dimensions of image and whether you want the image to tile or not.

Apache is downloading php files instead of displaying them

this solved the problem for me (I have php7 installed):

sudo apt-get install libapache2-mod-php7.0

sudo service apache2 restart

Granting DBA privileges to user in Oracle

You need only to write:

GRANT DBA TO NewDBA;

Because this already makes the user a DB Administrator

img src SVG changing the styles with CSS

for that matters you have to use your SVG as an inline HTML.

say here's your logo.svg code (when you open it on textEditor):

Logo.SVG

<svg width="139" height="100" xmlns="http://www.w3.org/2000/svg">
    <!-- Note that I've Added Class Attribute 'logo-img' Here -->
    <g transform="translate(-22 -45)" fill="none" fill-rule="evenodd">
        <path
            d="M158.023 48.118a7.625 7.625 0 01-.266 10.78l-88.11 83.875a7.625 7.625 0 01-10.995-.5l-33.89-38.712a7.625 7.625 0 0111.475-10.045l28.653 32.73 82.353-78.394a7.625 7.625 0 0110.78.266z"
            fill="#00000" />
    </g>
</svg>

add your desired Class/ID to it (i've added 'logo-img'):

Edited Svg

<svg class="logo-img" width="139" height="100" xmlns="http://www.w3.org/2000/svg">
    <!-- Note that I've Added Class Attribute 'logo-img' Here -->
    ...
</svg>

Now apply Your Css Rules:

CSS

.logo-img path {
   fill: #000;
}

Pro

  • With this way you can animate on user's actions (hover, selected,...)

Con

  • Your HTML File would be a mess.

Heres a Stack Snippet

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<style>
        body {
            display: flex;
            justify-content: center;
        }
        .logo-img path {
            transition: .5s all linear;
        }
        .logo-img path {
            fill: coral;
        }
        .logo-img:hover path{
            fill: darkblue;
        }
        
    </style>
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<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    
</head>

<body>
    <svg class="logo-img" width="139" height="100" xmlns="http://www.w3.org/2000/svg">
        <!-- Note that I've Added Class Attribute 'logo-img' Here -->
        <g transform="translate(-22 -45)" fill="none" fill-rule="evenodd">
            <path
                d="M158.023 48.118a7.625 7.625 0 01-.266 10.78l-88.11 83.875a7.625 7.625 0 01-10.995-.5l-33.89-38.712a7.625 7.625 0 0111.475-10.045l28.653 32.73 82.353-78.394a7.625 7.625 0 0110.78.266z"
                fill="#00000" />
        </g>
    </svg>
</body>

</html>
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Android Drawing Separator/Divider Line in Layout?

It adds a horizontal divider to anywhere in your layout.

    <TextView
       style="?android:listSeparatorTextViewStyle"
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"/>

How to deselect all selected rows in a DataGridView control?

Set

dgv.CurrentCell = null;

when user clicks on a blank part of the dgv.

converting json to string in python

json.dumps() is much more than just making a string out of a Python object, it would always produce a valid JSON string (assuming everything inside the object is serializable) following the Type Conversion Table.

For instance, if one of the values is None, the str() would produce an invalid JSON which cannot be loaded:

>>> data = {'jsonKey': None}
>>> str(data)
"{'jsonKey': None}"
>>> json.loads(str(data))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/__init__.py", line 338, in loads
    return _default_decoder.decode(s)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/decoder.py", line 366, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/decoder.py", line 382, in raw_decode
    obj, end = self.scan_once(s, idx)
ValueError: Expecting property name: line 1 column 2 (char 1)

But the dumps() would convert None into null making a valid JSON string that can be loaded:

>>> import json
>>> data = {'jsonKey': None}
>>> json.dumps(data)
'{"jsonKey": null}'
>>> json.loads(json.dumps(data))
{u'jsonKey': None}

Convert between UIImage and Base64 string

In Swift 3.0 and Xcode 8.0

Encoding :

let userImage:UIImage = UIImage(named: "Your-Image_name")!
let imageData:NSData = UIImagePNGRepresentation(userImage)! as NSData
let dataImage = imageData.base64EncodedString(options: .lineLength64Characters)

Decoding :

let imageData = dataImage
let dataDecode:NSData = NSData(base64Encoded: imageData!, options:.ignoreUnknownCharacters)!
let avatarImage:UIImage = UIImage(data: dataDecode as Data)!
yourImageView.image = avatarImage

Configuring ObjectMapper in Spring

It may be because I'm using Spring 3.1 (instead of Spring 3.0.5 as your question specified), but Steve Eastwood's answer didn't work for me. This solution works for Spring 3.1:

In your spring xml context:

<mvc:annotation-driven>
    <mvc:message-converters>
        <bean class="org.springframework.http.converter.StringHttpMessageConverter"/>
        <bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter"/>
        <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">
            <property name="objectMapper" ref="jacksonObjectMapper" />
        </bean>        
    </mvc:message-converters>
</mvc:annotation-driven>

<bean id="jacksonObjectMapper" class="de.Company.backend.web.CompanyObjectMapper" />

How to check whether the user uploaded a file in PHP?

I checked your code and think you should try this:

if(!file_exists($_FILES['fileupload']['tmp_name']) || !is_uploaded_file($_FILES['fileupload']['tmp_name'])) 
    {
        echo 'No upload';
    }   
    else
        echo 'upload';

How to pass an array into a function, and return the results with an array

You seem to be looking for pass-by-reference, to do that make your function look this way (note the ampersand):

function foo(&$array)
{
    $array[3]=$array[0]+$array[1]+$array[2];
}

Alternately, you can assign the return value of the function to a variable:

function foo($array)
{
    $array[3]=$array[0]+$array[1]+$array[2];
    return $array;
}

$waffles = foo($waffles)

Create unique constraint with null columns

Create two partial indexes:

CREATE UNIQUE INDEX favo_3col_uni_idx ON favorites (user_id, menu_id, recipe_id)
WHERE menu_id IS NOT NULL;

CREATE UNIQUE INDEX favo_2col_uni_idx ON favorites (user_id, recipe_id)
WHERE menu_id IS NULL;

This way, there can only be one combination of (user_id, recipe_id) where menu_id IS NULL, effectively implementing the desired constraint.

Possible drawbacks: you cannot have a foreign key referencing (user_id, menu_id, recipe_id), you cannot base CLUSTER on a partial index, and queries without a matching WHERE condition cannot use the partial index. (It seems unlikely you'd want a FK reference three columns wide - use the PK column instead).

If you need a complete index, you can alternatively drop the WHERE condition from favo_3col_uni_idx and your requirements are still enforced.
The index, now comprising the whole table, overlaps with the other one and gets bigger. Depending on typical queries and the percentage of NULL values, this may or may not be useful. In extreme situations it might even help to maintain all three indexes (the two partial ones and a total on top).

Aside: I advise not to use mixed case identifiers in PostgreSQL.

Create URL from a String

URL url = new URL(yourUrl, "/api/v1/status.xml");

According to the javadocs this constructor just appends whatever resource to the end of your domain, so you would want to create 2 urls:

URL domain = new URL("http://example.com");
URL url = new URL(domain + "/files/resource.xml");

Sources: http://docs.oracle.com/javase/6/docs/api/java/net/URL.html

Go Back to Previous Page

Try this:

$previous = "javascript:history.go(-1)";
if(isset($_SERVER['HTTP_REFERER'])) {
    $previous = $_SERVER['HTTP_REFERER'];
}

in html:

<a href="<?= $previous ?>">Back</a>

The JavaScript code is initialize as fallback for HTTP_REFERER variable sometimes not work.

Regex Last occurrence?

You can try anchoring it to the end of the string, something like \\[^\\]*$. Though I'm not sure if one absolutely has to use regexp for the task.

how to use json file in html code

You can use JavaScript like... Just give the proper path of your json file...

<!doctype html>
<html>
    <head>
        <script type="text/javascript" src="abc.json"></script>
        <script type="text/javascript" >
            function load() {
                var mydata = JSON.parse(data);
                alert(mydata.length);

                var div = document.getElementById('data');

                for(var i = 0;i < mydata.length; i++)
                {
                    div.innerHTML = div.innerHTML + "<p class='inner' id="+i+">"+ mydata[i].name +"</p>" + "<br>";
                }
            }
        </script>
    </head>
    <body onload="load()">
        <div id="data">

        </div>
    </body>
</html>

Simply getting the data and appending it to a div... Initially printing the length in alert.

Here is my Json file: abc.json

data = '[{"name" : "Riyaz"},{"name" : "Javed"},{"name" : "Arun"},{"name" : "Sunil"},{"name" : "Rahul"},{"name" : "Anita"}]';

make arrayList.toArray() return more specific types

A shorter version of converting List to Array of specific type (for example Long):

Long[] myArray = myList.toArray(Long[]::new);

Check if Internet Connection Exists with jQuery?

I wrote a jQuery plugin for doing this. By default it checks the current URL (because that's already loaded once from the Web) or you can specify a URL to use as an argument. Always doing a request to Google isn't the best idea because it's blocked in different countries at different times. Also you might be at the mercy of what the connection across a particular ocean/weather front/political climate might be like that day.

http://tomriley.net/blog/archives/111

PHP code to remove everything but numbers

This is for future developers, you can also try this. Simple too

echo preg_replace('/\D/', '', '604-619-5135');

Regular expression for a hexadecimal number?

Another example: Hexadecimal values for css colors start with a pound sign, or hash (#), then six characters that can either be a numeral or a letter between A and F, inclusive.

^#[0-9a-fA-F]{6}

How do I remove a file from the FileList

Since JavaScript FileList is readonly and cannot be manipulated directly,

BEST METHOD

You will have to loop through the input.files while comparing it with the index of the file you want to remove. At the same time, you will use new DataTransfer() to set a new list of files excluding the file you want to remove from the file list.

With this approach, the value of the input.files itself is changed.

removeFileFromFileList(index) {
  const dt = new DataTransfer()
  const input = document.getElementById('files')
  const { files } = input
  for (let i = 0; i < files.length; i++) {
    const file = files[i]
    if (index !== i) dt.items.add(file) // here you exclude the file. thus removing it.
    input.files = dt.files
  }
}

ALTERNATIVE METHOD

Another simple method is to convert the FileList into an array and then splice it.

But this approach will not change the input.files

const input = document.getElementById('files')
// as an array, u have more freedom to transform the file list using array functions.
const fileListArr = Array.from(input.files)
fileListArr.splice(index, 1) // here u remove the file
console.log(fileListArr)

Programmatically set TextBlock Foreground Color

Foreground needs a Brush, so you can use

textBlock.Foreground = Brushes.Navy;

If you want to use the color from RGB or ARGB then

textBlock.Foreground = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromArgb(100, 255, 125, 35)); 

or

textBlock.Foreground = new System.Windows.Media.SolidColorBrush(Colors.Navy); 

To get the Color from Hex

textBlock.Foreground = new System.Windows.Media.SolidColorBrush((Color)ColorConverter.ConvertFromString("#FFDFD991")); 

Reading values from DataTable

I think it will work

for (int i = 1; i <= broj_ds; i++ ) 
  { 

     QuantityInIssueUnit_value = dr_art_line_2[i]["Column"];
     QuantityInIssueUnit_uom  = dr_art_line_2[i]["Column"];

  }

How to insert date values into table

insert into run(id,name,dob)values(&id,'&name',[what should I write here?]);

insert into run(id,name,dob)values(&id,'&name',TO_DATE('&dob','YYYY-MM-DD'));

LaTeX Optional Arguments

The general idea behind creating "optional arguments" is to first define an intermediate command that scans ahead to detect what characters are coming up next in the token stream and then inserts the relevant macros to process the argument(s) coming up as appropriate. This can be quite tedious (although not difficult) using generic TeX programming. LaTeX's \@ifnextchar is quite useful for such things.

The best answer for your question is to use the new xparse package. It is part of the LaTeX3 programming suite and contains extensive features for defining commands with quite arbitrary optional arguments.

In your example you have a \sec macro that either takes one or two braced arguments. This would be implemented using xparse with the following:

\documentclass{article}
\usepackage{xparse}
\begin{document}
\DeclareDocumentCommand\sec{ m g }{%
    {#1%
        \IfNoValueF {#2} { and #2}%
    }%
}
(\sec{Hello})
(\sec{Hello}{Hi})
\end{document}

The argument { m g } defines the arguments of \sec; m means "mandatory argument" and g is "optional braced argument". \IfNoValue(T)(F) can then be used to check whether the second argument was indeed present or not. See the documentation for the other types of optional arguments that are allowed.

Simple int to char[] conversion

If you want to convert an int which is in the range 0-9 to a char, you may usually write something like this:

int x;
char c = '0' + x;

Now, if you want a character string, just add a terminating '\0' char:

char s[] = {'0' + x, '\0'};

Note that:

  1. You must be sure that the int is in the 0-9 range, otherwise it will fail,
  2. It works only if character codes for digits are consecutive. This is true in the vast majority of systems, that are ASCII-based, but this is not guaranteed to be true in all cases.

jQuery click event on radio button doesn't get fired

It fires. Check demo http://jsfiddle.net/yeyene/kbAk3/

$("#inline_content input[name='type']").click(function(){
    alert('You clicked radio!');
    if($('input:radio[name=type]:checked').val() == "walk_in"){
        alert($('input:radio[name=type]:checked').val());
        //$('#select-table > .roomNumber').attr('enabled',false);
    }
});

How to increase size of DOSBox window?

For using DOSBox with SDL, you will need to set or change the following:

[sdl]
windowresolution=1280x960
output=opengl

Here is three options to put those settings:

  1. Edit user's default configuration, for example, using vi:

    $ dosbox -printconf
    /home/USERNAME/.dosbox/dosbox-0.74.conf
    $ vi "$(dosbox -printconf)"
    $ dosbox
    
  2. For temporary resize, create a new configuration with the three lines above, say newsize.conf:

    $ dosbox -conf newsize.conf
    

    You can use -conf to load multiple configuration and/or with -userconf for default configuration, for example:

    $ dosbox -userconf -conf newsize.conf 
    [snip]
    ---
    CONFIG:Loading primary settings from config file /home/USERNAME/.dosbox/dosbox-0.74.conf
    CONFIG:Loading additional settings from config file newsize.conf
    [snip]
    
  3. Create a dosbox.conf under current directory, DOSBox loads it as default.

DOSBox should start up and resize to 1280x960 in this case.

Note that you probably would not get any size you desired, for instance, I set 1280x720 and I got 1152x720.

What is the difference between null=True and blank=True in Django?

Here, is the main difference of null=True and blank=True:

The default value of both null and blank is False. Both of these values work at field level i.e., whether we want to keep a field null or blank.

null=True will set the field’s value to NULL i.e., no data. It is basically for the databases column value.

date = models.DateTimeField(null=True)

blank=True determines whether the field will be required in forms. This includes the admin and your own custom forms.

title = models.CharField(blank=True) // title can be kept blank. In the database ("") will be stored. null=True blank=True This means that the field is optional in all circumstances.

epic = models.ForeignKey(null=True, blank=True)
// The exception is CharFields() and TextFields(), which in Django are never saved as NULL. Blank values a

Python Inverse of a Matrix

You could calculate the determinant of the matrix which is recursive and then form the adjoined matrix

Here is a short tutorial

I think this only works for square matrices

Another way of computing these involves gram-schmidt orthogonalization and then transposing the matrix, the transpose of an orthogonalized matrix is its inverse!

ASP.NET document.getElementById('<%=Control.ClientID%>'); returns null

Gotcha!

You have to use RegisterStartupScript instead of RegisterClientScriptBlock

Here My Example.

MasterPage:

<%@ Master Language="C#" AutoEventWireup="true" CodeBehind="MasterPage.master.cs"
    Inherits="prueba.MasterPage" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>

    <script type="text/javascript">

        function confirmCallBack() {
            var a = document.getElementById('<%= Page.Master.FindControl("ContentPlaceHolder1").FindControl("Button1").ClientID %>');

            alert(a.value);

        }

    </script>

    <asp:ContentPlaceHolder ID="head" runat="server">
    </asp:ContentPlaceHolder>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">
        </asp:ContentPlaceHolder>
    </div>
    </form>
</body>
</html>

WebForm1.aspx

<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPage.Master" AutoEventWireup="true"
    CodeBehind="WebForm1.aspx.cs" Inherits="prueba.WebForm1" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">

</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
<asp:Button ID="Button1" runat="server" Text="Button" />
</asp:Content>

WebForm1.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace prueba
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            ClientScript.RegisterStartupScript(this.GetType(), "js", "confirmCallBack();", true);

        }
    }
}

How to call multiple JavaScript functions in onclick event?

A link with 1 function defined

<a href="#" onclick="someFunc()">Click me To fire some functions</a>

Firing multiple functions from someFunc()

function someFunc() {
    showAlert();
    validate();
    anotherFunction();
    YetAnotherFunction();
}

How to remove the character at a given index from a string in C?

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 50
void dele_char(char s[],char ch)
{
    int i,j;

    for(i=0;s[i]!='\0';i++)
    {
        if(s[i]==ch)
        {
            for(j=i;s[j]!='\0';j++)
            s[j]=s[j+1];
            i--;
        }
    }
}

int main()
{
    char s[MAX],ch;
    printf("Enter the string\n");
    gets(s);
    printf("Enter The char to be deleted\n");
    scanf("%c",&ch);
    dele_char(s,ch);
    printf("After Deletion:= %s\n",s);
    return 0;
}

PostgreSQL: days/months/years between two dates

SELECT date_part ('year', f) * 12
     + date_part ('month', f)
FROM age ('2015-06-12'::DATE, '2014-12-01'::DATE) f

Result: 6

How to make a gui in python

Tkinter is the "standard" GUI for Python, meaning it should be available with every Python installation.

In terms of learning it, and particularly learning how to use recent versions of Tkinter (which have improved a lot), I very highly recommend the TkDocs tutorial that I put together a while back - see http://www.tkdocs.com

Loaded with examples, covers basic concepts and all of the core widgets.

What is the best way to conditionally apply a class?

Here is another option that works well when ng-class can't be used (for example when styling SVG):

ng-attr-class="{{someBoolean && 'class-when-true' || 'class-when-false' }}"

(I think you need to be on latest unstable Angular to use ng-attr-, I'm currently on 1.1.4)

CSS opacity only to background color, not the text on it?

For anyone coming across this thread, here's a script called thatsNotYoChild.js that I just wrote that solves this problem automatically:

http://www.impressivewebs.com/fixing-parent-child-opacity/

Basically, it separates children from the parent element, but keeps the element in the same physical location on the page.

Pythonically add header to a csv file

You just add one additional row before you execute the loop. This row contains your CSV file header name.

schema = ['a','b','c','b']
row = 4
generators = ['A','B','C','D']
with open('test.csv','wb') as csvfile:    
     writer = csv.writer(csvfile, delimiter=delimiter)
# Gives the header name row into csv
     writer.writerow([g for g in schema])   
#Data add in csv file       
     for x in xrange(rows):
         writer.writerow([g() for g in generators])

Using sed, Insert a line above or below the pattern?

More portable to use ed; some systems don't support \n in sed

printf "/^lorem ipsum dolor sit amet/a\nconsectetur adipiscing elit\n.\nw\nq\n" |\
    /bin/ed $filename

Laravel Soft Delete posts

Just an update for Laravel 5:

In Laravel 4.2:

use Illuminate\Database\Eloquent\SoftDeletingTrait;    
class Post extends Eloquent {

    use SoftDeletingTrait;

    protected $dates = ['deleted_at'];

}

becomes in Laravel 5:

use Illuminate\Database\Eloquent\SoftDeletes;

class User extends Model {

    use SoftDeletes;
    protected $dates = ['deleted_at'];

How do I get the value of a textbox using jQuery?

Noticed your comment about using it for email validation and needing a plugin, the validation plugin may help you, its located at http://bassistance.de/jquery-plugins/jquery-plugin-validation/, it comes with a e-mail rule as well.

How to Validate a DateTime in C#?

Don't use exceptions for flow control. Use DateTime.TryParse and DateTime.TryParseExact. Personally I prefer TryParseExact with a specific format, but I guess there are times when TryParse is better. Example use based on your original code:

DateTime value;
if (!DateTime.TryParse(startDateTextBox.Text, out value))
{
    startDateTextox.Text = DateTime.Today.ToShortDateString();
}

Reasons for preferring this approach:

  • Clearer code (it says what it wants to do)
  • Better performance than catching and swallowing exceptions
  • This doesn't catch exceptions inappropriately - e.g. OutOfMemoryException, ThreadInterruptedException. (Your current code could be fixed to avoid this by just catching the relevant exception, but using TryParse would still be better.)

Docker - a way to give access to a host USB or serial device?

It's hard for us to bind a specific USB device to a docker container which is also specific. As you can see, the recommended way to achieve is:

docker run -t -i --privileged -v /dev/bus/usb:/dev/bus/usb ubuntu bash

It will bind all the devices to this container. It's unsafe. Every containers were granted to operate all of them.

Another way is binding devices by devpath. It may looks like:

docker run -t -i --privileged -v /dev/bus/usb/001/002:/dev/bus/usb/001/002 ubuntu bash

or --device (better, no privileged):

docker run -t -i --device /dev/bus/usb/001/002 ubuntu bash

Much safer. But actually it is hard to know what the devpath of a specific device is.

I have wrote this repo to solve this problem.

https://github.com/williamfzc/usb2container

After deploying this server, you can easily get all the connected devices' information via HTTP request:

curl 127.0.0.1:9410/api/device

and get:

{
    "/devices/pci0000:00/0000:00:14.0/usb1/1-13": {
        "ACTION": "add",
        "DEVPATH": "/devices/pci0000:00/0000:00:14.0/usb1/1-13",
        "DEVTYPE": "usb_device",
        "DRIVER": "usb",
        "ID_BUS": "usb",
        "ID_FOR_SEAT": "xxxxx",
        "ID_MODEL": "xxxxx",
        "ID_MODEL_ID": "xxxxx",
        "ID_PATH": "xxxxx",
        "ID_PATH_TAG": "xxxxx",
        "ID_REVISION": "xxxxx",
        "ID_SERIAL": "xxxxx",
        "ID_SERIAL_SHORT": "xxxxx",
        "ID_USB_INTERFACES": "xxxxx",
        "ID_VENDOR": "xxxxx",
        "ID_VENDOR_ENC": "xxxxx",
        "ID_VENDOR_FROM_DATABASE": "",
        "ID_VENDOR_ID": "xxxxx",
        "INTERFACE": "",
        "MAJOR": "189",
        "MINOR": "119",
        "MODALIAS": "",
        "PRODUCT": "xxxxx",
        "SEQNUM": "xxxxx",
        "SUBSYSTEM": "usb",
        "TAGS": "",
        "TYPE": "0/0/0",
        "USEC_INITIALIZED": "xxxxx",
        "adb_user": "",
        "_empty": false,
        "DEVNAME": "/dev/bus/usb/001/120",
        "BUSNUM": "001",
        "DEVNUM": "120",
        "ID_MODEL_ENC": "xxxxx"
    },
    ...
}

and bind them to your containers. For example, you can see the DEVNAME of this device is /dev/bus/usb/001/120:

docker run -t -i --device /dev/bus/usb/001/120 ubuntu bash

Maybe it will help.

new DateTime() vs default(DateTime)

No, they are identical.

default(), for any value type (DateTime is a value type) will always call the parameterless constructor.

How can I read command line parameters from an R script?

If you need to specify options with flags, (like -h, --help, --number=42, etc) you can use the R package optparse (inspired from Python): http://cran.r-project.org/web/packages/optparse/vignettes/optparse.pdf.

At least this how I understand your question, because I found this post when looking for an equivalent of the bash getopt, or perl Getopt, or python argparse and optparse.

A python class that acts like dict

I really don't see the right answer to this anywhere

class MyClass(dict):
    
    def __init__(self, a_property):
        self[a_property] = a_property

All you are really having to do is define your own __init__ - that really is all that there is too it.

Another example (little more complex):

class MyClass(dict):

    def __init__(self, planet):
        self[planet] = planet
        info = self.do_something_that_returns_a_dict()
        if info:
            for k, v in info.items():
                self[k] = v

    def do_something_that_returns_a_dict(self):
        return {"mercury": "venus", "mars": "jupiter"}

This last example is handy when you want to embed some kind of logic.

Anyway... in short class GiveYourClassAName(dict) is enough to make your class act like a dict. Any dict operation you do on self will be just like a regular dict.

How to check if an email address is real or valid using PHP

You should check with SMTP.

That means you have to connect to that email's SMTP server.

After connecting to the SMTP server you should send these commands:

HELO somehostname.com
MAIL FROM: <[email protected]>
RCPT TO: <[email protected]>

If you get "<[email protected]> Relay access denied" that means this email is Invalid.

There is a simple PHP class. You can use it:

http://www.phpclasses.org/package/6650-PHP-Check-if-an-e-mail-is-valid-using-SMTP.html

SQLAlchemy insert or update example

assuming certain column names...

INSERT one

newToner = Toner(toner_id = 1,
                    toner_color = 'blue',
                    toner_hex = '#0F85FF')

dbsession.add(newToner)   
dbsession.commit()

INSERT multiple

newToner1 = Toner(toner_id = 1,
                    toner_color = 'blue',
                    toner_hex = '#0F85FF')

newToner2 = Toner(toner_id = 2,
                    toner_color = 'red',
                    toner_hex = '#F01731')

dbsession.add_all([newToner1, newToner2])   
dbsession.commit()

UPDATE

q = dbsession.query(Toner)
q = q.filter(Toner.toner_id==1)
record = q.one()
record.toner_color = 'Azure Radiance'

dbsession.commit()

or using a fancy one-liner using MERGE

record = dbsession.merge(Toner( **kwargs))

How can I tell when HttpClient has timed out?

Basically, you need to catch the OperationCanceledException and check the state of the cancellation token that was passed to SendAsync (or GetAsync, or whatever HttpClient method you're using):

  • if it was canceled (IsCancellationRequested is true), it means the request really was canceled
  • if not, it means the request timed out

Of course, this isn't very convenient... it would be better to receive a TimeoutException in case of timeout. I propose a solution here based on a custom HTTP message handler: Better timeout handling with HttpClient

Generating 8-character only UUIDs

Not a UUID, but this works for me:

UUID.randomUUID().toString().replace("-","").substring(0,8)

How to use continue in jQuery each() loop?

We can break the $.each() loop at a particular iteration by making the callback function return false. Returning non-false is the same as a continue statement in a for loop; it will skip immediately to the next iteration. -- jQuery.each() | jQuery API Documentation

jQuery access input hidden value

There is nothing special about <input type="hidden">:

$('input[type="hidden"]').val()

How do I delete everything below row X in VBA/Excel?

Any Reference to 'Row' should use 'long' not 'integer' else it will overflow if the spreadsheet has a lot of data.

Permutation of array

Here is how you can print all permutations in 10 lines of code:

public class Permute{
    static void permute(java.util.List<Integer> arr, int k){
        for(int i = k; i < arr.size(); i++){
            java.util.Collections.swap(arr, i, k);
            permute(arr, k+1);
            java.util.Collections.swap(arr, k, i);
        }
        if (k == arr.size() -1){
            System.out.println(java.util.Arrays.toString(arr.toArray()));
        }
    }
    public static void main(String[] args){
        Permute.permute(java.util.Arrays.asList(3,4,6,2,1), 0);
    }
}

You take first element of an array (k=0) and exchange it with any element (i) of the array. Then you recursively apply permutation on array starting with second element. This way you get all permutations starting with i-th element. The tricky part is that after recursive call you must swap i-th element with first element back, otherwise you could get repeated values at the first spot. By swapping it back we restore order of elements (basically you do backtracking).

Iterators and Extension to the case of repeated values

The drawback of previous algorithm is that it is recursive, and does not play nicely with iterators. Another issue is that if you allow repeated elements in your input, then it won't work as is.

For example, given input [3,3,4,4] all possible permutations (without repetitions) are

[3, 3, 4, 4]
[3, 4, 3, 4]
[3, 4, 4, 3]
[4, 3, 3, 4]
[4, 3, 4, 3]
[4, 4, 3, 3]

(if you simply apply permute function from above you will get [3,3,4,4] four times, and this is not what you naturally want to see in this case; and the number of such permutations is 4!/(2!*2!)=6)

It is possible to modify the above algorithm to handle this case, but it won't look nice. Luckily, there is a better algorithm (I found it here) which handles repeated values and is not recursive.

First note, that permutation of array of any objects can be reduced to permutations of integers by enumerating them in any order.

To get permutations of an integer array, you start with an array sorted in ascending order. You 'goal' is to make it descending. To generate next permutation you are trying to find the first index from the bottom where sequence fails to be descending, and improves value in that index while switching order of the rest of the tail from descending to ascending in this case.

Here is the core of the algorithm:

//ind is an array of integers
for(int tail = ind.length - 1;tail > 0;tail--){
    if (ind[tail - 1] < ind[tail]){//still increasing

        //find last element which does not exceed ind[tail-1]
        int s = ind.length - 1;
        while(ind[tail-1] >= ind[s])
            s--;

        swap(ind, tail-1, s);

        //reverse order of elements in the tail
        for(int i = tail, j = ind.length - 1; i < j; i++, j--){
            swap(ind, i, j);
        }
        break;
    }
}

Here is the full code of iterator. Constructor accepts an array of objects, and maps them into an array of integers using HashMap.

import java.lang.reflect.Array;
import java.util.*;
class Permutations<E> implements  Iterator<E[]>{

    private E[] arr;
    private int[] ind;
    private boolean has_next;

    public E[] output;//next() returns this array, make it public

    Permutations(E[] arr){
        this.arr = arr.clone();
        ind = new int[arr.length];
        //convert an array of any elements into array of integers - first occurrence is used to enumerate
        Map<E, Integer> hm = new HashMap<E, Integer>();
        for(int i = 0; i < arr.length; i++){
            Integer n = hm.get(arr[i]);
            if (n == null){
                hm.put(arr[i], i);
                n = i;
            }
            ind[i] = n.intValue();
        }
        Arrays.sort(ind);//start with ascending sequence of integers


        //output = new E[arr.length]; <-- cannot do in Java with generics, so use reflection
        output = (E[]) Array.newInstance(arr.getClass().getComponentType(), arr.length);
        has_next = true;
    }

    public boolean hasNext() {
        return has_next;
    }

    /**
     * Computes next permutations. Same array instance is returned every time!
     * @return
     */
    public E[] next() {
        if (!has_next)
            throw new NoSuchElementException();

        for(int i = 0; i < ind.length; i++){
            output[i] = arr[ind[i]];
        }


        //get next permutation
        has_next = false;
        for(int tail = ind.length - 1;tail > 0;tail--){
            if (ind[tail - 1] < ind[tail]){//still increasing

                //find last element which does not exceed ind[tail-1]
                int s = ind.length - 1;
                while(ind[tail-1] >= ind[s])
                    s--;

                swap(ind, tail-1, s);

                //reverse order of elements in the tail
                for(int i = tail, j = ind.length - 1; i < j; i++, j--){
                    swap(ind, i, j);
                }
                has_next = true;
                break;
            }

        }
        return output;
    }

    private void swap(int[] arr, int i, int j){
        int t = arr[i];
        arr[i] = arr[j];
        arr[j] = t;
    }

    public void remove() {

    }
}

Usage/test:

    TCMath.Permutations<Integer> perm = new TCMath.Permutations<Integer>(new Integer[]{3,3,4,4,4,5,5});
    int count = 0;
    while(perm.hasNext()){
        System.out.println(Arrays.toString(perm.next()));
        count++;
    }
    System.out.println("total: " + count);

Prints out all 7!/(2!*3!*2!)=210 permutations.

Should I learn C before learning C++?

I think you should learn C first, because I learned C first. C gave me a good grasp of the syntax and gotchas with things like pointers, all of which flow into C++.

I think C++ makes it easy to wrap up all those gotchas (need an array that won't overflow when you use the [] operator and a dodgy index? Sure, make an array class that does bounds checking) but you need to know what they are and get bitten by them before you understand why things are done in certain ways.

When all is said and done, the way C++ is usually taught is "C++ is C with objects, here's the C stuff and here's how all this OO stuff works", so you're likely to learn basic C before any real C++ if you follow most texts anyway.

Sending mail attachment using Java

This worked for me.

Here I assume my attachment is of a PDF type format.

Comments are made to understand it clearly.

public class MailAttachmentTester {
    public static void main(String[] args) {
        // Recipient's email ID needs to be mentioned.
        String to = "[email protected]";
        // Sender's email ID needs to be mentioned
        String from = "[email protected]";
        final String username = "[email protected]";//change accordingly
        final String password = "test";//change accordingly
        // Assuming you are sending email through relay.jangosmtp.net
        Properties props = new Properties();
        props.put("mail.smtp.host", "smtp.gmail.com");
        props.put("mail.smtp.socketFactory.port", "465");
        props.put("mail.smtp.socketFactory.class",
                "javax.net.ssl.SSLSocketFactory");
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.port", "465");
        // Get the Session object.
        Session session = Session.getInstance(props,
                new javax.mail.Authenticator() {
                    protected PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication(username, password);
                    }
                });
        try {
            // Create a default MimeMessage object.
            Message message = new MimeMessage(session);
            // Set From: header field of the header.
            message.setFrom(new InternetAddress(from));
            // Set To: header field of the header.
            message.setRecipients(Message.RecipientType.TO,
                    InternetAddress.parse(to));
            // Set Subject: header field
            message.setSubject("Attachment");
            // Create the message part
            BodyPart messageBodyPart = new MimeBodyPart();
            // Now set the actual message
            messageBodyPart.setText("Please find the attachment below");
            // Create a multipar message
            Multipart multipart = new MimeMultipart();
            // Set text message part
            multipart.addBodyPart(messageBodyPart);
            // Part two is attachment
            messageBodyPart = new MimeBodyPart();
            String filename = "D:/test.PDF";
            DataSource source = new FileDataSource(filename);
            messageBodyPart.setDataHandler(new DataHandler(source));
            messageBodyPart.setFileName(filename);
            multipart.addBodyPart(messageBodyPart);
            // Send the complete message parts
            message.setContent(multipart);
            // Send message
            Transport.send(message);
            System.out.println("Email Sent Successfully !!");
        } catch (MessagingException e) {
            throw new RuntimeException(e);
        }
    }

} 

Delete commits from a branch in Git

If you didn't publish changes, to remove latest commit, you can do

$ git reset --hard HEAD^

(note that this would also remove all uncommitted changes; use with care).

If you already published to-be-deleted commit, use git revert

$ git revert HEAD

How to auto import the necessary classes in Android Studio with shortcut?

On Windows with Android Studio 1.5.1 : File --> Settings --> Editor --> General --> Auto Import

enter image description here

How do I redirect users after submit button click?

use

window.location.replace("login.php");

or simply window.location("login.php");

It is better than using window.location.href =, because replace() does not put the originating page in the session history, meaning the user won't get stuck in a never-ending back-button fiasco. If you want to simulate someone clicking on a link, use location.href. If you want to simulate an HTTP redirect, use location.replace.

Gradle failed to resolve library in Android Studio

For me follwing steps helped.

It seems to be bug of Android Studio 3.4/3.5 and it was "fixed" by disabling:

File ? Settings ? Experimental ? Gradle ? Only sync the active variant

Alter SQL table - allow NULL column value

The following MySQL statement should modify your column to accept NULLs.

ALTER TABLE `MyTable`
ALTER COLUMN `Col3` varchar(20) DEFAULT NULL

How do I use DrawerLayout to display over the ActionBar/Toolbar and under the status bar?

I am Using Design Support Library. And just by using custom theme I achived transparent Status Bar when Opened Navigation Drawer.

enter image description here

enter image description here

<style name="NavigationStyle" parent="Theme.AppCompat.Light.NoActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/primaryColor</item>
    <item name="colorPrimaryDark">@color/primaryColorDark</item>

    <!-- To Make Navigation Drawer Fill Status Bar and become Transparent Too -->
    <item name="android:windowDrawsSystemBarBackgrounds">true</item>
    <item name="android:statusBarColor">@android:color/transparent</item>

</style>

Finally add theme in Manifest File

<activity
  ........
  ........
 android:theme="@style/NavigationStyle"> 
</activity>

Do not forget to use the property, android:fitsSystemWindows="true" in "DrawerLayout"

htaccess remove index.php from url

The original answer is actually correct, but lacks explanation. I would like to add some explanations and modifications.

I suggest reading this short introduction https://httpd.apache.org/docs/2.4/rewrite/intro.html (15mins) and reference these 2 pages while reading.

https://httpd.apache.org/docs/2.4/mod/mod_rewrite.html https://httpd.apache.org/docs/2.4/rewrite/flags.html


This is the basic rule to hide index.php from the URL. Put this in your root .htaccess file.

mod_rewrite must be enabled with PHP and this will work for the PHP version higher than 5.2.6.

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule (.*) /index.php/$1 [L]

Think %{REQUEST_FILENAME} as the the path after host.

E.g. https://www.example.com/index.html, %{REQUEST_FILENAME} is /index.html

So the last 3 lines means, if it's not a regular file !-f and not a directory !-d, then do the RewriteRule.

As for RewriteRule formats:

enter image description here

So RewriteRule (.*) /index.php/$1 [L] means, if the 2 RewriteCond are satisfied, it (.*) would match everything after the hostname. . matches any single character , .* matches any characters and (.*) makes this a variables can be references with $1, then replace with /index.php/$1. The final effect is to add a preceding index.php to the whole URL path.

E.g. for https://www.example.com/hello, it would produce, https://www.example.com/index.php/hello internally.

Another key problem is that this indeed solve the question. Internally, (I guess) it always need https://www.example.com/index.php/hello, but with rewriting, you could visit the site without index.php, apache adds that for you internally.


Btw, making an extra .htaccess file is not very recommended by the Apache doc.

Rewriting is typically configured in the main server configuration setting (outside any <Directory> section) or inside <VirtualHost> containers. This is the easiest way to do rewriting and is recommended

ASP.NET MVC 3 Razor - Adding class to EditorFor

You could also do it via jQuery:

$('#x_Created').addClass(date);

Non-conformable arrays error in code

The problem is that omega in your case is matrix of dimensions 1 * 1. You should convert it to a vector if you wish to multiply t(X) %*% X by a scalar (that is omega)

In particular, you'll have to replace this line:

omega   = rgamma(1,a0,1) / L0

with:

omega   = as.vector(rgamma(1,a0,1) / L0)

everywhere in your code. It happens in two places (once inside the loop and once outside). You can substitute as.vector(.) or c(t(.)). Both are equivalent.

Here's the modified code that should work:

gibbs = function(data, m01 = 0, m02 = 0, k01 = 0.1, k02 = 0.1, 
                     a0 = 0.1, L0 = 0.1, nburn = 0, ndraw = 5000) {
    m0      = c(m01, m02) 
    C0      = matrix(nrow = 2, ncol = 2) 
    C0[1,1] = 1 / k01 
    C0[1,2] = 0 
    C0[2,1] = 0 
    C0[2,2] = 1 / k02 
    beta    = mvrnorm(1,m0,C0) 
    omega   = as.vector(rgamma(1,a0,1) / L0)
    draws   = matrix(ncol = 3,nrow = ndraw) 
    it      = -nburn 

    while (it < ndraw) {
        it    = it + 1 
        C1    = solve(solve(C0) + omega * t(X) %*% X) 
        m1    = C1 %*% (solve(C0) %*% m0 + omega * t(X) %*% y)
        beta  = mvrnorm(1, m1, C1) 
        a1    = a0 + n / 2 
        L1    = L0 + t(y - X %*% beta) %*% (y - X %*% beta) / 2 
        omega = as.vector(rgamma(1, a1, 1) / L1)
        if (it > 0) { 
            draws[it,1] = beta[1]
            draws[it,2] = beta[2]
            draws[it,3] = omega
        }
    }
    return(draws)
}

This action could not be completed. Try Again (-22421)

My problem was with the provisional profiles.

So for me it worked:

Go to Xcode preferences -> Accounts -> In my ID Apple Account -> Select "Download All"

I checked too, in member center and delete all invalid provisionals profiles and:

1 - Close Xcode

2 - Open Xcode, do clean and build of my project.

3 - Archive my code again.

Modular multiplicative inverse function in Python

from the cpython implementation source code:

def invmod(a, n):
    b, c = 1, 0
    while n:
        q, r = divmod(a, n)
        a, b, c, n = n, c, b - q*c, r
    # at this point a is the gcd of the original inputs
    if a == 1:
        return b
    raise ValueError("Not invertible")

according to the comment above this code, it can return small negative values, so you could potentially check if negative and add n when negative before returning b.

Why is an OPTIONS request sent and can I disable it?

Yes it's possible to avoid options request. Options request is a preflight request when you send (post) any data to another domain. It's a browser security issue. But we can use another technology: iframe transport layer. I strongly recommend you forget about any CORS configuration and use readymade solution and it will work anywhere.

Take a look here: https://github.com/jpillora/xdomain

And working example: http://jpillora.com/xdomain/

Appending to an existing string

Can I ask why this is important?

I know that this is not a direct answer to your question, but the fact that you are trying to preserve the object ID of a string might indicate that you should look again at what you are trying to do.

You might find, for instance, that relying on the object ID of a string will lead to bugs that are quite hard to track down.

Use Conditional formatting to turn a cell Red, yellow or green depending on 3 values in another sheet

  1. Highlight the range in question.
  2. On the Home tab, in the Styles Group, Click "Conditional Formatting".
  3. Click "Highlight cell rules"

For the first rule,

Click "greater than", then in the value option box, click on the cell criteria you want it to be less than, than use the format drop-down to select your color.

For the second,

Click "less than", then in the value option box, type "=.9*" and then click the cell criteria, then use the formatting just like step 1.

For the third,

Same as the second, except your formula is =".8*" rather than .9.

How to validate a form with multiple checkboxes to have atleast one checked

This script below should put you on the right track perhaps?

You can keep this html the same (though I changed the method to POST):

<form method="POST" id="subscribeForm">
    <fieldset id="cbgroup">
        <div><input name="list" id="list0" type="checkbox"  value="newsletter0" >zero</div>
        <div><input name="list" id="list1" type="checkbox"  value="newsletter1" >one</div>
        <div><input name="list" id="list2" type="checkbox"  value="newsletter2" >two</div>
    </fieldset>
    <input name="submit" type="submit"  value="submit">
</form>

and this javascript validates

function onSubmit() 
{ 
    var fields = $("input[name='list']").serializeArray(); 
    if (fields.length === 0) 
    { 
        alert('nothing selected'); 
        // cancel submit
        return false;
    } 
    else 
    { 
        alert(fields.length + " items selected"); 
    }
}

// register event on form, not submit button
$('#subscribeForm').submit(onSubmit)

and you can find a working example of it here

UPDATE (Oct 2012)
Additionally it should be noted that the checkboxes must have a "name" property, or else they will not be added to the array. Only having "id" will not work.

UPDATE (May 2013)
Moved the submit registration to javascript and registered the submit onto the form (as it should have been originally)

UPDATE (June 2016)
Changes == to ===

Adding author name in Eclipse automatically to existing files

To old files I don't know how to do it... I think you will need a script to go thru all files and add the header.

To change the new ones you can do this.

Go to Eclipse menu bar

  1. Window menu.
  2. Preferences
  3. search for Templates
  4. go to Code templates
  5. click on +code
  6. Click on New Java files
  7. Click Edit
  8. add

/**
${user}
*/

And it's done every new File will have your name on it !

SQL Server Insert Example

To insert a single row of data:

INSERT INTO USERS
VALUES (1, 'Mike', 'Jones');

To do an insert on specific columns (as opposed to all of them) you must specify the columns you want to update.

INSERT INTO USERS (FIRST_NAME, LAST_NAME)
VALUES ('Stephen', 'Jiang');

To insert multiple rows of data in SQL Server 2008 or later:

INSERT INTO USERS VALUES
(2, 'Michael', 'Blythe'),
(3, 'Linda', 'Mitchell'),
(4, 'Jillian', 'Carson'),
(5, 'Garrett', 'Vargas');

To insert multiple rows of data in earlier versions of SQL Server, use "UNION ALL" like so:

INSERT INTO USERS (FIRST_NAME, LAST_NAME)
SELECT 'James', 'Bond' UNION ALL
SELECT 'Miss', 'Moneypenny' UNION ALL
SELECT 'Raoul', 'Silva'

Note, the "INTO" keyword is optional in INSERT queries. Source and more advanced querying can be found here.

How to specify test directory for mocha?

As @jeff-dickey suggested, in the root of your project, make a folder called test. In that folder, make a file called mocha.opts. Now where I try to improve on Jeff's answer, what worked for me was instead of specifying the name of just one test folder, I specified a pattern to find all tests to run in my project by adding this line:

*/tests/*.js --recursive in mocha.opts

If you instead want to specify the exact folders to look for tests in, I did something like this:

shared/tests/*.js --recursive
server/tests/graph/*.js --recursive

I hope this helps anyone who needed more than what the other answers provide

How to have Java method return generic list of any type?

Let us have List<Object> objectList which we want to cast to List<T>

public <T> List<T> list(Class<T> c, List<Object> objectList){        
    List<T> list = new ArrayList<>();       
    for (Object o : objectList){
        T t = c.cast(o);
        list.add(t);
    }
    return list;
}

Get file name from URI string in C#

The accepted answer is problematic for http urls. Moreover Uri.LocalPath does Windows specific conversions, and as someone pointed out leaves query strings in there. A better way is to use Uri.AbsolutePath

The correct way to do this for http urls is:

Uri uri = new Uri(hreflink);
string filename = System.IO.Path.GetFileName(uri.AbsolutePath);

How do you read scanf until EOF in C?

Scanf is pretty much always more trouble than it's worth. Here are two better ways to do what you're trying to do. This first one is a more-or-less direct translation of your code. It's longer, but you can look at it and see clearly what it does, unlike with scanf.

#include <stdio.h>
#include <ctype.h>
int main(void)
{
    char buf[1024], *p, *q;
    while (fgets(buf, 1024, stdin))
    {
        p = buf;
        while (*p)
        {
            while (*p && isspace(*p)) p++;
            q = p;
            while (*q && !isspace(*q)) q++;
            *q = '\0';
            if (p != q)
                puts(p);
            p = q;
        }
    }
    return 0;
}

And here's another version. It's a little harder to see what this does by inspection, but it does not break if a line is longer than 1024 characters, so it's the code I would use in production. (Well, really what I would use in production is tr -s '[:space:]' '\n', but this is how you implement something like that.)

#include <stdio.h>
#include <ctype.h>
int main(void)
{
    int ch, lastch = '\0';
    while ((ch = getchar()) != EOF)
    {
        if (!isspace(ch))
            putchar(ch);
        if (!isspace(lastch))
            putchar('\n');
        lastch = ch;
    }
    if (lastch != '\0' && !isspace(lastch))
        putchar('\n');
    return 0;
}

Struct like objects in Java

I frequently use this pattern when building private inner classes to simplify my code, but I would not recommend exposing such objects in a public API. In general, the more frequently you can make objects in your public API immutable the better, and it is not possible to construct your 'struct-like' object in an immutable fashion.

As an aside, even if I were writing this object as a private inner class I would still provide a constructor to simplify the code to initialize the object. Having to have 3 lines of code to get a usable object when one will do is just messy.

How to check that Request.QueryString has a specific value or not in ASP.NET?

You can just check for null:

if(Request.QueryString["aspxerrorpath"]!=null)
{
   //your code that depends on aspxerrorpath here
}

How to concatenate characters in java?

System.out.print(a + "" + b + "" + c);

How to specify more spaces for the delimiter using cut?

I still like the way Perl handles fields with white space.
First field is $F[0].

$ ps axu | grep dbus | perl -lane 'print $F[4]'

How do I create a dictionary with keys from a list and values defaulting to (say) zero?

In addition to Tim's answer, which is very appropriate to your specific example, it's worth mentioning collections.defaultdict, which lets you do stuff like this:

>>> d = defaultdict(int)
>>> d[0] += 1
>>> d
{0: 1}
>>> d[4] += 1
>>> d
{0: 1, 4: 1}

For mapping [1, 2, 3, 4] as in your example, it's a fish out of water. But depending on the reason you asked the question, this may end up being a more appropriate technique.

Android App Not Install. An existing package by the same name with a conflicting signature is already installed

If you are using the debug apk, the key that is used to sign it is in

C:\Users\<user>\.android\debug.keystore

If you use that same key, there should not be a conflict when installing.

XAMPP Apache Webserver localhost not working on MAC OS

In my case, Web Sharing was running, which blocked XAMPP.

'Untick' Web Sharing in the Bluetooth Settings (or Network), which causes HTTPD to show in activity log.

Apache should now run and be available!

event Action<> vs event EventHandler<>

Looking at Standard .NET event patterns we find

The standard signature for a .NET event delegate is:

void OnEventRaised(object sender, EventArgs args);

[...]

The argument list contains two arguments: the sender, and the event arguments. The compile time type of sender is System.Object, even though you likely know a more derived type that would always be correct. By convention, use object.

Below on same page we find an example of the typical event definition which is something like

public event EventHandler<EventArgs> EventName;

Had we defined

class MyClass
{
  public event Action<MyClass, EventArgs> EventName;
}

the handler could have been

void OnEventRaised(MyClass sender, EventArgs args);

where sender has the correct (more derived) type.

React - Display loading screen while DOM is rendering?

The workaround for this is:

In your render function do something like this:

constructor() {
    this.state = { isLoading: true }
}

componentDidMount() {
    this.setState({isLoading: false})
}

render() {
    return(
        this.state.isLoading ? *showLoadingScreen* : *yourPage()*
    )
}

Initialize isLoading as true in the constructor and false on componentDidMount

java.lang.NoClassDefFoundError:failed resolution of :Lorg/apache/http/ProtocolVersion

According to this SO answer, it occurs due to an AWS SDK bug that appears to be solved in version 2.6.30 of the SDK, so updating the version to a newer, can help you fixing the problem.

Using the "start" command with parameters passed to the started program

None of these answers worked for me.

Instead, I had to use the Call command:

Call "\\Path To Program\Program.exe" <parameters>

I'm not sure this actually waits for completion... the C++ Redistributable I was installing went fast enough that it didn't matter

How do you revert to a specific tag in Git?

Use git reset:

git reset --hard "Version 1.0 Revision 1.5"

(assuming that the specified string is the tag).

How to get the filename without the extension from a path in Python?

If you want to keep the path to the file and just remove the extension

>>> file = '/root/dir/sub.exten/file.data.1.2.dat'
>>> print ('.').join(file.split('.')[:-1])
/root/dir/sub.exten/file.data.1.2

conversion from string to json object android

Remove the slashes:

String json = {"phonetype":"N95","cat":"WP"};

try {

    JSONObject obj = new JSONObject(json);

    Log.d("My App", obj.toString());

} catch (Throwable t) {
    Log.e("My App", "Could not parse malformed JSON: \"" + json + "\"");
}

How to execute .sql file using powershell?

Here is a function that I have in my PowerShell profile for loading SQL snapins:

function Load-SQL-Server-Snap-Ins
{
    try 
    {
        $sqlpsreg="HKLM:\SOFTWARE\Microsoft\PowerShell\1\ShellIds\Microsoft.SqlServer.Management.PowerShell.sqlps"

        if (!(Test-Path $sqlpsreg -ErrorAction "SilentlyContinue"))
        {
            throw "SQL Server Powershell is not installed yet (part of SQLServer installation)."
        }

        $item = Get-ItemProperty $sqlpsreg
        $sqlpsPath = [System.IO.Path]::GetDirectoryName($item.Path)

        $assemblyList = @(
            "Microsoft.SqlServer.Smo",
            "Microsoft.SqlServer.SmoExtended",
            "Microsoft.SqlServer.Dmf",
            "Microsoft.SqlServer.WmiEnum",
            "Microsoft.SqlServer.SqlWmiManagement",
            "Microsoft.SqlServer.ConnectionInfo ",
            "Microsoft.SqlServer.Management.RegisteredServers",
            "Microsoft.SqlServer.Management.Sdk.Sfc",
            "Microsoft.SqlServer.SqlEnum",
            "Microsoft.SqlServer.RegSvrEnum",
            "Microsoft.SqlServer.ServiceBrokerEnum",
            "Microsoft.SqlServer.ConnectionInfoExtended",
            "Microsoft.SqlServer.Management.Collector",
            "Microsoft.SqlServer.Management.CollectorEnum"
        )

        foreach ($assembly in $assemblyList)
        { 
            $assembly = [System.Reflection.Assembly]::LoadWithPartialName($assembly) 
            if ($assembly -eq $null)
                { Write-Host "`t`t($MyInvocation.InvocationName): Could not load $assembly" }
        }

        Set-Variable -scope Global -name SqlServerMaximumChildItems -Value 0
        Set-Variable -scope Global -name SqlServerConnectionTimeout -Value 30
        Set-Variable -scope Global -name SqlServerIncludeSystemObjects -Value $false
        Set-Variable -scope Global -name SqlServerMaximumTabCompletion -Value 1000

        Push-Location

         if ((Get-PSSnapin -Name SqlServerProviderSnapin100 -ErrorAction SilentlyContinue) -eq $null) 
        { 
            cd $sqlpsPath

            Add-PsSnapin SqlServerProviderSnapin100 -ErrorAction Stop
            Add-PsSnapin SqlServerCmdletSnapin100 -ErrorAction Stop
            Update-TypeData -PrependPath SQLProvider.Types.ps1xml
            Update-FormatData -PrependPath SQLProvider.Format.ps1xml
        }
    } 

    catch 
    {
        Write-Host "`t`t$($MyInvocation.InvocationName): $_" 
    }

    finally
    {
        Pop-Location
    }
}

How do I exit from the text window in Git?

On windows, simply pressing 'q' on the keyboard quits this screen. I got it when I was reading help using '!help' or simply 'help' and 'enter', from the DOS prompt.

Happy Coding :-)

How do I stop a web page from scrolling to the top when a link is clicked that triggers JavaScript?

An easy approach is to leverage this code:

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

This approach doesn't force a page refresh, so the scrollbar stays in place. Also, it allows you to programmatically change the onclick event and handle client side event binding using jQuery.

For these reasons, the above solution is better than:

<a href="javascript:myClickHandler();">Link Title</a>
<a href="#" onclick="myClickHandler(); return false;">Link Title</a>

where the last solution will avoid the scroll-jump issue if and only if the myClickHandler method doesn't fail.

Converting a Date object to a calendar object

it's so easy...converting a date to calendar like this:

Calendar cal=Calendar.getInstance();
DateFormat format=new SimpleDateFormat("yyyy/mm/dd");
format.format(date);
cal=format.getCalendar();

Get size of a View in React Native

This is the only thing that worked for me:

import React, { Component } from 'react';
import {
  AppRegistry,
  StyleSheet,
  Text,
  View,
  Image
} from 'react-native';

export default class Comp extends Component {

  find_dimesions(layout){
    const {x, y, width, height} = layout;
    console.warn(x);
    console.warn(y);
    console.warn(width);
    console.warn(height);
  }
  render() {
    return (
      <View onLayout={(event) => { this.find_dimesions(event.nativeEvent.layout) }} style={styles.container}>
        <Text style={styles.welcome}>
          Welcome to React Native!
        </Text>
        <Text style={styles.instructions}>
          To get started, edit index.android.js
        </Text>
        <Text style={styles.instructions}>
          Double tap R on your keyboard to reload,{'\n'}
          Shake or press menu button for dev menu
        </Text>
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#F5FCFF',
  },
  welcome: {
    fontSize: 20,
    textAlign: 'center',
    margin: 10,
  },
  instructions: {
    textAlign: 'center',
    color: '#333333',
    marginBottom: 5,
  },
});

AppRegistry.registerComponent('Comp', () => Comp);

Clearing <input type='file' /> using jQuery

I was able to get mine working with the following code:

var input = $("#control");    
input.replaceWith(input.val('').clone(true));

How to convert POJO to JSON and vice versa?

We can also make use of below given dependency and plugin in your pom file - I make use of maven. With the use of these you can generate POJO's as per your JSON Schema and then make use of code given below to populate request JSON object via src object specified as parameter to gson.toJson(Object src) or vice-versa. Look at the code below:

Gson gson = new GsonBuilder().create();
String payloadStr = gson.toJson(data.getMerchant().getStakeholder_list());

Gson gson2 = new Gson();
Error expectederr = gson2.fromJson(payloadStr, Error.class);

And the Maven settings:

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>1.7.1</version>
</dependency>

<plugin>
    <groupId>com.googlecode.jsonschema2pojo</groupId>
    <artifactId>jsonschema2pojo-maven-plugin</artifactId>
    <version>0.3.7</version>
    <configuration>
        <sourceDirectory>${basedir}/src/main/resources/schema</sourceDirectory>
        <targetPackage>com.example.types</targetPackage>
    </configuration>
    <executions>
        <execution>
            <phase>generate-sources</phase>
            <goals>
                <goal>generate</goal>
            </goals>
        </execution>
    </executions>
</plugin>

mongo - couldn't connect to server 127.0.0.1:27017

if u install by brew (on osx) first run sudo mkdir /data/db start mondoDB Daemon by typing mongod (leave it open) and then run mongo by typing mongo in new terminal tab

Load local javascript file in chrome for testing?

The easiest workaround I have found is to use Firefox. Not only does it work with no extra steps (drag and drop - no muss no fuss), but blackboxing works better than Chrome.

Finding the second highest number in array

import java.util.*;
public class SecondLargestNew
{
    public static void main(String args[])
    {
        int[] array = {0,12,74,26,82,3,89,8,94,3};  

    int highest = Integer.MIN_VALUE;
    int secondHighest = Integer.MIN_VALUE;


    for (int i = 0; i < array.length; i++) 
    {
        if (array[i] > highest) 
        {
            // ...shift the current highest number to second highest
            secondHighest = highest;
            // ...and set the new highest.
            highest = array[i];
        } else if (array[i] > secondHighest)
            {
            // Just replace the second highest
            secondHighest = array[i];
            }
    }
    System.out.println("second largest is "+secondHighest );
    System.out.println("largest is "+ highest);
        }
}

enter image description here

Type converting slices of interfaces

The thing you are missing is that T and interface{} which holds a value of T have different representations in memory so can't be trivially converted.

A variable of type T is just its value in memory. There is no associated type information (in Go every variable has a single type known at compile time not at run time). It is represented in memory like this:

  • value

An interface{} holding a variable of type T is represented in memory like this

  • pointer to type T
  • value

So coming back to your original question: why go does't implicitly convert []T to []interface{}?

Converting []T to []interface{} would involve creating a new slice of interface {} values which is a non-trivial operation since the in-memory layout is completely different.

How to force the browser to reload cached CSS and JavaScript files

You can just put ?foo=1234 at the end of your CSS / JavaScript import, changing 1234 to be whatever you like. Have a look at the Stack Overflow HTML source for an example.

The idea there being that the ? parameters are discarded / ignored on the request anyway and you can change that number when you roll out a new version.


Note: There is some argument with regard to exactly how this affects caching. I believe the general gist of it is that GET requests, with or without parameters should be cachable, so the above solution should work.

However, it is down to both the web server to decide if it wants to adhere to that part of the spec and the browser the user uses, as it can just go right ahead and ask for a fresh version anyway.

Check if list<t> contains any of another list

You could use a nested Any() for this check which is available on any Enumerable:

bool hasMatch = myStrings.Any(x => parameters.Any(y => y.source == x));

Faster performing on larger collections would be to project parameters to source and then use Intersect which internally uses a HashSet<T> so instead of O(n^2) for the first approach (the equivalent of two nested loops) you can do the check in O(n) :

bool hasMatch = parameters.Select(x => x.source)
                          .Intersect(myStrings)
                          .Any(); 

Also as a side comment you should capitalize your class names and property names to conform with the C# style guidelines.

JavaScript require() on client side

I've been using browserify for that. It also lets me integrate Node.js modules into my client-side code.

I blogged about it here: Add node.js/CommonJS style require() to client-side JavaScript with browserify

Importing project into Netbeans

From Netbeans 8.1 - there is an "Import from ZIP" option.

Go to Main Menu -> File -> Import Project -> from ZIP.

Browse your .ZIP file's location via Browse button.

If you have Java project depending on external Libraries, Netbeans will highlight & ask for "Resolving problems" in project, click on resolve, provide location in your file system containing required library files .e.g JARs etc & you will be good to go.

Is there a "do ... until" in Python?

There is no do-while loop in Python.

This is a similar construct, taken from the link above.

 while True:
     do_something()
     if condition():
        break

Could not complete the operation due to error 80020101. IE

I dont know why but it worked for me. If you have comments like

//Comment

Then it gives this error. To fix this do

/*Comment*/

Doesn't make sense but it worked for me.

How to get all checked checkboxes

In IE9+, Chrome or Firefox you can do:

var checkedBoxes = document.querySelectorAll('input[name=mycheckboxes]:checked');

How can I change the color of a Google Maps marker?

MapIconMaker: a library for Google Maps v2

One way is to use the MapIconMaker(deadlink). There's an example here(deadlink). Google Maps default icons are 20px width and 34px height, so you could use something like this to emulate:

var newIcon = MapIconMaker.createMarkerIcon({width: 20, height: 34, primaryColor: "#0000FF", cornercolor:"#0000FF"});
var marker = new GMarker(map.getCenter(), {icon: newIcon});

You could even wrap it in some function to make things even easier on yourself:

function getIcon(color) {
    return MapIconMaker.createMarkerIcon({width: 20, height: 34, primaryColor: color, cornercolor:color});
}

That's what I personally use for all markers I create. I prefer to have the option to change colors of a whim.

Update: The Hex color of the default icon is "#FE7569". Also, you can setImage on a Marker rather than creating a new Marker with a new icon. So if you want a function to highlight you could go with something like this, using the function above:

function highlightMarker(marker, highlight) {
    var color = "#FE7569";
    if (highlight) {
        color = "#0000FF";
    }
    marker.setImage(getIcon(color).image);
}

StyledMarker: a library for Google Maps v3

Since V2 was replaced by V3 sometime ago I thought I should update this answer. I created a library for custom markers that can be found on the V3 Utility Library here(deadlink). It allows for different colors and shapes, and you can place text on the marker as well. It works by using the Google Charts API which has methods for creating Google Maps type markers. Feel free to look at the source code if you'd rather use the Google Charts API directly.

The thing about that library, however, is that it takes care of defining the clickable regions of these marker images for you, so, for instance, the longer bubble with text will have the clickable regions one expects, like this example(deadlink).

Select every Nth element in CSS

Try this

div:nth-child(4n+4)

What do the result codes in SVN mean?

I usually use svn through a gui, either my IDE or a client. Because of that, I can never remember the codes when I do have to resort to the command line.

I find this cheat sheet a great help: Subversion Cheat Sheet

Java replace issues with ' (apostrophe/single quote) and \ (backslash) together

Example :

String teste = " 'Bauru '";

teste = teste.replaceAll("  '  ","");
JOptionPane.showMessageDialog(null,teste);

How do I check if a variable exists?

A way that often works well for handling this kind of situation is to not explicitly check if the variable exists but just go ahead and wrap the first usage of the possibly non-existing variable in a try/except NameError:

# Search for entry.
for x in y:
  if x == 3:
    found = x

# Work with found entry.
try:
  print('Found: {0}'.format(found))
except NameError:
  print('Not found')
else:
  # Handle rest of Found case here
  ...

Can curl make a connection to any TCP ports, not just HTTP/HTTPS?

Of course:

curl http://example.com:11740
curl https://example.com:11740

Port 80 and 443 are just default port numbers.

How do I delete an item or object from an array using ng-click?

In case you're inside an ng-repeat

you could use a one liner option

    <div ng-repeat="key in keywords"> 
        <button ng-click="keywords.splice($index, 1)">

            {{key.name}}
        </button>
    </div>

$index is used by angular to show current index of the array inside ng-repeat

How to make div's percentage width relative to parent div and not viewport

Use position: relative on the parent element.

Also note that had you not added any position attributes to any of the divs you wouldn't have seen this behavior. Juan explains further.

How to push files to an emulator instance using Android Studio

You can use the ADB via a terminal to pass the file From Desktop to Emulator.

adb push <file-source-local> <destination-path-remote>

You can also copy file from emulator to Desktop

adb pull <file-source-remote> <destination-path>

How ever you can also use the Android Device Monitor to access files. Click on the Android Icon which can be found in the toolbar itself. It'll take few seconds to load. Once it's loaded, you can see a tab named "File Explorer". Now you could pull/push files from there.

Javascript, viewing [object HTMLInputElement]

<input type="text" />
<script>
$("input:text").change(function() {
    var value=$("input:text").val();
    alert(value);
});
</script>

use .val() to get value of the element (jquery method), $("input:text") this selector to select your input, .change() to bind an event handler to the "change" JavaScript event.

Call to a member function on a non-object

you can use 'use' in function like bellow example

function page_properties($objPortal) use($objPage){    
    $objPage->set_page_title($myrow['title']);
}

Loading custom functions in PowerShell

I kept using this all this time

Import-module .\build_functions.ps1 -Force

Checking if any elements in one list are in another

You could solve this many ways. One that is pretty simple to understand is to just use a loop.

def comp(list1, list2):
    for val in list1:
        if val in list2:
            return True
    return False

A more compact way you can do it is to use map and reduce:

reduce(lambda v1,v2: v1 or v2, map(lambda v: v in list2, list1))

Even better, the reduce can be replaced with any:

any(map(lambda v: v in list2, list1))

You could also use sets:

len(set(list1).intersection(list2)) > 0

How do I 'foreach' through a two-dimensional array?

If you define your array like this:

string[][] table = new string[][] {
                       new string[] { "aa", "aaa" },
                       new string[]{ "bb", "bbb" }
};

Then you can use a foreach loop on it.

Log all queries in mysql

For the record, general_log and slow_log were introduced in 5.1.6:

http://dev.mysql.com/doc/refman/5.1/en/log-destinations.html

5.2.1. Selecting General Query and Slow Query Log Output Destinations

As of MySQL 5.1.6, MySQL Server provides flexible control over the destination of output to the general query log and the slow query log, if those logs are enabled. Possible destinations for log entries are log files or the general_log and slow_log tables in the mysql database

Fit image to table cell [Pure HTML]

It's all about display: block :)

Updated:

Ok so you have the table, tr and td tags:

<table>
  <tr>
    <td>
      <!-- your image goes here -->
    </td>
  </tr>
</table>

Lets say your table or td (whatever define your width) has property width: 360px;. Now, when you try to replace the html comment with the actual image and set that image property for example width: 100%; which should fully fill out the td cell you will face the problem.

The problem is that your table cell (td) isn't properly filled with the image. You'll notice the space at the bottom of the cell which your image doesn't cover (it's like 5px of padding).

How to solve this in a simpliest way?

You are working with the tables, right? You just need to add the display property to your image so that it has the following:

img {
  width: 100%;
  display: block;
}

How to use variables in a command in sed?

Say:

sed "s|\$ROOT|${HOME}|" abc.sh

Note:

  • Use double quotes so that the shell would expand variables.
  • Use a separator different than / since the replacement contains /
  • Escape the $ in the pattern since you don't want to expand it.

EDIT: In order to replace all occurrences of $ROOT, say

sed "s|\$ROOT|${HOME}|g" abc.sh

How to create a DateTime equal to 15 minutes ago?

I have provide two methods for doing so for minutes as well as for years and hours if you want to see more examples:

import datetime
print(datetime.datetime.now())
print(datetime.datetime.now() - datetime.timedelta(minutes = 15))
print(datetime.datetime.now() + datetime.timedelta(minutes = -15))
print(datetime.timedelta(hours = 5))
print(datetime.datetime.now() + datetime.timedelta(days = 3))
print(datetime.datetime.now() + datetime.timedelta(days = -9))
print(datetime.datetime.now() - datetime.timedelta(days = 9))

I get the following results:

2016-06-03 16:04:03.706615
2016-06-03 15:49:03.706622
2016-06-03 15:49:03.706642
5:00:00
2016-06-06 16:04:03.706665
2016-05-25 16:04:03.706676
2016-05-25 16:04:03.706687
2016-06-03
16:04:03.706716

Rotate label text in seaborn factorplot

Aman is correct that you can use normal matplotlib commands, but this is also built into the FacetGrid:

import seaborn as sns
planets = sns.load_dataset("planets")
g = sns.factorplot("year", data=planets, aspect=1.5, kind="count", color="b")
g.set_xticklabels(rotation=30)

enter image description here

There are some comments and another answer claiming this "doesn't work", however, anyone can run the code as written here and see that it does work. The other answer does not provide a reproducible example of what isn't working, making it very difficult to address, but my guess is that people are trying to apply this solution to the output of functions that return an Axes object instead of a Facet Grid. These are different things, and the Axes.set_xticklabels() method does indeed require a list of labels and cannot simply change the properties of the existing labels on the Axes. The lesson is that it's important to pay attention to what kind of objects you are working with.

Parenthesis/Brackets Matching using Stack algorithm

I have seen answers here and almost all did well. However, I have written my own version that utilizes a Dictionary for managing the bracket pairs and a stack to monitor the order of detected braces. I have also written a blog post for this.

Here is my class

public class FormulaValidator
{
    // Question: Check if a string is balanced. Every opening bracket is matched by a closing bracket in a correct position.
    // { [ ( } ] )

    // Example: "()" is balanced
    // Example: "{ ]" is not balanced.
    // Examples: "()[]{}" is balanced.
    // "{([])}" is balanced
    // "{ ( [ ) ] }" is _not_ balanced

    // Input: string, containing the bracket symbols only
    // Output: true or false
    public bool IsBalanced(string input)
    {
        var brackets = BuildBracketMap();
        var openingBraces = new Stack<char>();
        var inputCharacters = input.ToCharArray();

        foreach (char character in inputCharacters)
        {
            if (brackets.ContainsKey(character))
            {
                openingBraces.Push(character);
            }

            if (brackets.ContainsValue(character))
            {
                var closingBracket = character;
                var openingBracket = brackets.FirstOrDefault(x => x.Value == closingBracket).Key;

                if (openingBraces.Peek() == openingBracket)
                    openingBraces.Pop();
                else
                    return false;
            }
        }

        return openingBraces.Count == 0;
    }

    private Dictionary<char, char> BuildBracketMap()
    {
        return new Dictionary<char, char>()
        {
            {'[', ']'},
            {'(', ')'},
            {'{', '}'}
        };
    }
}

How to replace space with comma using sed?

Try the following command and it should work out for you.

sed "s/\s/,/g" orignalFive.csv > editedFinal.csv

Turn off display errors using file "php.ini"

You should consider not displaying your error messages instead!

Set ini_set('display_errors', 'Off'); in your PHP code (or directly into your ini file if possible), and leave error_reporting on E_ALL or whatever kind of messages you would like to find in your logs.

This way you can handle errors later, while your users still don't see them.

Full example:

define('DEBUG', true);
error_reporting(E_ALL);

if (DEBUG)
{
    ini_set('display_errors', 'On');
}
else
{
    ini_set('display_errors', 'Off');
}

Or simply (same effect):

define('DEBUG', true);

error_reporting(E_ALL);
ini_set('display_errors', DEBUG ? 'On' : 'Off');

Is there a function to split a string in PL/SQL?

You can use regexp_substr(). Example:

create or replace type splitTable_Type is table of varchar2(100);

declare
    l_split_table splitTable_Type;
begin
  select
      regexp_substr('SMITH,ALLEN,WARD,JONES','[^,]+', 1, level)
  bulk collect into
      l_split_table
  from dual
  connect by
      regexp_substr('SMITH,ALLEN,WARD,JONES', '[^,]+', 1, level) is not null;
end;

The query iterates through the comma separated string, searches for the comma (,) and then splits the string by treating the comma as delimiter. It returns the string as a row, whenever it hits a delimiter.

level in statement regexp_substr('SMITH,ALLEN,WARD,JONES','[^,]+', 1, level) refers to a pseudocolumn in Oracle which is used in a hierarchical query to identify the hierarchy level in numeric format: level in connect by

Find nginx version?

Make sure that you have permissions to run the following commands.

If you check the man page of nginx from a terminal

man nginx

you can find this:

-V             Print the nginx version, compiler version, and configure script parameters.

-v             Print the nginx version.

Then type in terminal

nginx -v
nginx version: nginx/1.14.0

nginx -V
nginx version: nginx/1.14.0
built with OpenSSL 1.1.0g  2 Nov 2017
TLS SNI support enabled

If nginx is not installed in your system man nginx command can not find man page, so make sure you have installed nginx.

You can also find the version using this command:

Use one of the command to find the path of nginx

ps aux | grep nginx
ps -ef | grep nginx

root       883  0.0  0.3  44524  3388 ?        Ss   Dec07   0:00 nginx: master process /usr/sbin/nginx -g daemon on; master_process on

Then run from terminal:

/usr/sbin/nginx -v

nginx version: nginx/1.14.0

Reading an integer from user input

Better way is to use TryParse:

Int32 _userInput;
if(Int32.TryParse (Console.Readline(), out _userInput) {// do the stuff on userInput}

Javascript - Get Image height

Try this:

var curHeight;
var curWidth;

function getImgSize(imgSrc)
{
var newImg = new Image();
newImg.src = imgSrc;
curHeight = newImg.height;
curWidth = newImg.width;

}

CSS selectors ul li a {...} vs ul > li > a {...}

to answer to your second question - performance IS affected - if you are using those selectors with a single (no nested) ul:

<ul>
    <li>jjj</li>
    <li>jjj</li>    
    <li>jjj</li>
</ul>

the child selector ul > li is more performant than ul li because it is more specific. the browser traverse the dom "right to left", so when it finds a li it then looks for a any ul as a parent in the case of a child selector, while it has to traverse the whole dom tree to find any ul ancestors in case of the descendant selector

onCreateOptionsMenu inside Fragments

Set setHasMenuOptions(true) works if application has a theme with Actionbar such as Theme.MaterialComponents.DayNight.DarkActionBar or Activity has it's own Toolbar, otherwise onCreateOptionsMenu in fragment does not get called.

If you want to use standalone Toolbar you either need to get activity and set your Toolbar as support action bar with

(requireActivity() as? MainActivity)?.setSupportActionBar(toolbar)

which lets your fragment onCreateOptionsMenu to be called.

Other alternative is, you can inflate your Toolbar's own menu with toolbar.inflateMenu(R.menu.YOUR_MENU) and item listener with

toolbar.setOnMenuItemClickListener {
   // do something
   true
}

Android webview & localStorage

setDatabasePath() method was deprecated in API level 19. I advise you to use storage locale like this:

webView.getSettings().setDomStorageEnabled(true);
webView.getSettings().setDatabaseEnabled(true);
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
    webView.getSettings().setDatabasePath("/data/data/" + webView.getContext().getPackageName() + "/databases/");
}

In Visual Studio C++, what are the memory allocation representations?

There's actually quite a bit of useful information added to debug allocations. This table is more complete:

http://www.nobugs.org/developer/win32/debug_crt_heap.html#table

Address  Offset After HeapAlloc() After malloc() During free() After HeapFree() Comments
0x00320FD8  -40    0x01090009    0x01090009     0x01090009    0x0109005A     Win32 heap info
0x00320FDC  -36    0x01090009    0x00180700     0x01090009    0x00180400     Win32 heap info
0x00320FE0  -32    0xBAADF00D    0x00320798     0xDDDDDDDD    0x00320448     Ptr to next CRT heap block (allocated earlier in time)
0x00320FE4  -28    0xBAADF00D    0x00000000     0xDDDDDDDD    0x00320448     Ptr to prev CRT heap block (allocated later in time)
0x00320FE8  -24    0xBAADF00D    0x00000000     0xDDDDDDDD    0xFEEEFEEE     Filename of malloc() call
0x00320FEC  -20    0xBAADF00D    0x00000000     0xDDDDDDDD    0xFEEEFEEE     Line number of malloc() call
0x00320FF0  -16    0xBAADF00D    0x00000008     0xDDDDDDDD    0xFEEEFEEE     Number of bytes to malloc()
0x00320FF4  -12    0xBAADF00D    0x00000001     0xDDDDDDDD    0xFEEEFEEE     Type (0=Freed, 1=Normal, 2=CRT use, etc)
0x00320FF8  -8     0xBAADF00D    0x00000031     0xDDDDDDDD    0xFEEEFEEE     Request #, increases from 0
0x00320FFC  -4     0xBAADF00D    0xFDFDFDFD     0xDDDDDDDD    0xFEEEFEEE     No mans land
0x00321000  +0     0xBAADF00D    0xCDCDCDCD     0xDDDDDDDD    0xFEEEFEEE     The 8 bytes you wanted
0x00321004  +4     0xBAADF00D    0xCDCDCDCD     0xDDDDDDDD    0xFEEEFEEE     The 8 bytes you wanted
0x00321008  +8     0xBAADF00D    0xFDFDFDFD     0xDDDDDDDD    0xFEEEFEEE     No mans land
0x0032100C  +12    0xBAADF00D    0xBAADF00D     0xDDDDDDDD    0xFEEEFEEE     Win32 heap allocations are rounded up to 16 bytes
0x00321010  +16    0xABABABAB    0xABABABAB     0xABABABAB    0xFEEEFEEE     Win32 heap bookkeeping
0x00321014  +20    0xABABABAB    0xABABABAB     0xABABABAB    0xFEEEFEEE     Win32 heap bookkeeping
0x00321018  +24    0x00000010    0x00000010     0x00000010    0xFEEEFEEE     Win32 heap bookkeeping
0x0032101C  +28    0x00000000    0x00000000     0x00000000    0xFEEEFEEE     Win32 heap bookkeeping
0x00321020  +32    0x00090051    0x00090051     0x00090051    0xFEEEFEEE     Win32 heap bookkeeping
0x00321024  +36    0xFEEE0400    0xFEEE0400     0xFEEE0400    0xFEEEFEEE     Win32 heap bookkeeping
0x00321028  +40    0x00320400    0x00320400     0x00320400    0xFEEEFEEE     Win32 heap bookkeeping
0x0032102C  +44    0x00320400    0x00320400     0x00320400    0xFEEEFEEE     Win32 heap bookkeeping

Run javascript script (.js file) in mongodb including another file inside js

To call external file you can use :

load ("path\file")

Exemple: if your file.js file is on your "Documents" file (on windows OS), you can type:

load ("C:\users\user_name\Documents\file.js")

How can I change the version of npm using nvm?

I'm on Windows and I couldn't get any of this stuff to work. I kept getting errors about files being in the way. This worked though:

cd %APPDATA%\nvm\v8.10.0           # or whatever version you're using
mv npm npm-old
mv npm.cmd npm-old.cmd
cd node_modules\
mv npm npm-old
cd npm-old\bin
node npm-cli.js i -g npm@latest

cd %APPDATA%\nvm\v8.10.0 # or whatever version you're using
rm npm-old
rm npm-old.cmd
cd node_modules\
rm -rf npm-old

And boom, I'm back in business.

Hibernate vs JPA vs JDO - pros and cons of each?

I made a sample WebApp in May 2012 that uses JDO 3.0 & DataNucleus 3.0 - take a look how clean it is: https://github.com/TorbenVesterager/BadAssWebApp

Okay maybe it's a little bit too clean, because I use the POJOs both for the database and the JSON client, but it's fun :)

PS: Contains a few SuppressWarnings annotations (developed in IntelliJ 11)

Ruby optional parameters

You could do this with partial application, although using named variables definitely leads to more readable code. John Resig wrote a blog article in 2008 about how to do it in JavaScript: http://ejohn.org/blog/partial-functions-in-javascript/

Function.prototype.partial = function(){
  var fn = this, args = Array.prototype.slice.call(arguments);
  return function(){
    var arg = 0;
    for ( var i = 0; i < args.length && arg < arguments.length; i++ )
      if ( args[i] === undefined )
        args[i] = arguments[arg++];
    return fn.apply(this, args);
  };
};

It would probably be possible to apply the same principle in Ruby (except for the prototypal inheritance).

When to use RSpec let()?

let is functional as its essentially a Proc. Also its cached.

One gotcha I found right away with let... In a Spec block that is evaluating a change.

let(:object) {FactoryGirl.create :object}

expect {
  post :destroy, id: review.id
}.to change(Object, :count).by(-1)

You'll need to be sure to call let outside of your expect block. i.e. you're calling FactoryGirl.create in your let block. I usually do this by verifying the object is persisted.

object.persisted?.should eq true

Otherwise when the let block is called the first time a change in the database will actually happen due to the lazy instantiation.

Update

Just adding a note. Be careful playing code golf or in this case rspec golf with this answer.

In this case, I just have to call some method to which the object responds. So I invoke the _.persisted?_ method on the object as its truthy. All I'm trying to do is instantiate the object. You could call empty? or nil? too. The point isn't the test but bringing the object ot life by calling it.

So you can't refactor

object.persisted?.should eq true

to be

object.should be_persisted 

as the object hasn't been instantiated... its lazy. :)

Update 2

leverage the let! syntax for instant object creation, which should avoid this issue altogether. Note though it will defeat a lot of the purpose of the laziness of the non banged let.

Also in some instances you might actually want to leverage the subject syntax instead of let as it may give you additional options.

subject(:object) {FactoryGirl.create :object}

How do I update the GUI from another thread?

The simplest way is an anonymous method passed into Label.Invoke:

// Running on the worker thread
string newText = "abc";
form.Label.Invoke((MethodInvoker)delegate {
    // Running on the UI thread
    form.Label.Text = newText;
});
// Back on the worker thread

Notice that Invoke blocks execution until it completes--this is synchronous code. The question doesn't ask about asynchronous code, but there is lots of content on Stack Overflow about writing asynchronous code when you want to learn about it.

Sanitizing strings to make them URL and filename safe?

This is a good function:

public function getFriendlyURL($string) {
    setlocale(LC_CTYPE, 'en_US.UTF8');
    $string = iconv('UTF-8', 'ASCII//TRANSLIT//IGNORE', $string);
    $string = preg_replace('~[^\-\pL\pN\s]+~u', '-', $string);
    $string = str_replace(' ', '-', $string);
    $string = trim($string, "-");
    $string = strtolower($string);
    return $string;
} 

Vue-router redirect on page not found (404)

@mani's Original answer is all you want, but if you'd also like to read it in official way, here's

Reference to Vue's official page:

https://router.vuejs.org/guide/essentials/history-mode.html#caveat

php delete a single file in directory

The script you downloaded lists the content of a specified folder. You probably put the unlink - call in one of the while-loops that list the files.

EDIT - Now that you posted your code:

echo '<a href="'.unlink($FileLink).'"><img src="images/icons/delete.gif"></a></td>';

Doing this calls the unlink-function each time the line is written, deleting your file. You have to write a link to a script that contains a delete function and pass some parameter that tells your script what to delete.

Example:

<a href="/path/to/script.php?delete='. $FileLink .'">delete</a>

You should not pass the path to a file this script and just delete it though, because malevolent being might use it to just delete everything or do other evil things.

Scroll / Jump to id without jQuery

on anchor tag use href and not onclick

<a href="#target1">asdf<a>

And div:

<div id="target1">some content</div>

join on multiple columns

tableB.col1 = tableA.col1 
OR tableB.col2 = tableA.col1  
OR tableB.col1 = tableA.col2  
OR tableB.col1 = tableA.col2

What is the difference between pip and conda?

I may have found one further difference of a minor nature. I have my python environments under /usr rather than /home or whatever. In order to install to it, I would have to use sudo install pip. For me, the undesired side effect of sudo install pip was slightly different than what are widely reported elsewhere: after doing so, I had to run python with sudo in order to import any of the sudo-installed packages. I gave up on that and eventually found I could use sudo conda to install packages to an environment under /usr which then imported normally without needing sudo permission for python. I even used sudo conda to fix a broken pip rather than using sudo pip uninstall pip or sudo pip --upgrade install pip.

.NET HashTable Vs Dictionary - Can the Dictionary be as fast?

I guess it doesn't mean anything to you now. But just for reference for people stopping by

Performance Test - SortedList vs. SortedDictionary vs. Dictionary vs. Hashtable

Memory allocation:

Memory usage performance test

Time used for inserting:

Time used for inserting

Time for searching an item:

Time for searching an item

How to delete Tkinter widgets from a window?

You can call pack_forget to remove a widget (if you use pack to add it to the window).

Example:

from tkinter import *

root = Tk()

b = Button(root, text="Delete me", command=lambda: b.pack_forget())
b.pack()

root.mainloop()

If you use pack_forget, you can later show the widget again calling pack again. If you want to permanently delete it, call destroy on the widget (then you won't be able to re-add it).

If you use the grid method, you can use grid_forget or grid_remove to hide the widget.

Python: TypeError: cannot concatenate 'str' and 'int' objects

There are two ways to fix the problem which is caused by the last print statement.

You can assign the result of the str(c) call to c as correctly shown by @jamylak and then concatenate all of the strings, or you can replace the last print simply with this:

print "a + b as integers: ", c  # note the comma here

in which case

str(c)

isn't necessary and can be deleted.

Output of sample run:

Enter a: 3
Enter b: 7
a + b as strings:  37
a + b as integers:  10

with:

a = raw_input("Enter a: ")
b = raw_input("Enter b: ")
print "a + b as strings: " + a + b  # + everywhere is ok since all are strings
a = int(a)
b = int(b)
c = a + b
print "a + b as integers: ", c

Skip rows during csv import pandas

Also be sure that your file is actually a CSV file. For example, if you had an .xls file, and simply changed the file extension to .csv, the file won't import and will give the error above. To check to see if this is your problem open the file in excel and it will likely say:

"The file format and extension of 'Filename.csv' don't match. The file could be corrupted or unsafe. Unless you trust its source, don't open it. Do you want to open it anyway?"

To fix the file: open the file in Excel, click "Save As", Choose the file format to save as (use .cvs), then replace the existing file.

This was my problem, and fixed the error for me.