Programs & Examples On #Oracle text

a tool for building text query applications and document classification applications on top of Oracle databases. Oracle Text provides indexing, word and theme searching, as well as highlighting capabilities for text.

MySQL with Node.js

Imo, you should try MySQL Connector/Node.js which is the official Node.js driver for MySQL. See ref-1 and ref-2 for detailed explanation. I have tried mysqljs/mysql which is available here, but I don't find detailed documentation on classes, methods, properties of this library.

So I switched to the standard MySQL Connector/Node.js with X DevAPI, since it is an asynchronous Promise-based client library and provides good documentation. Take a look at the following code snippet :

const mysqlx = require('@mysql/xdevapi');
const rows = [];

mysqlx.getSession('mysqlx://localhost:33060')
.then(session => {
    const table = session.getSchema('testSchema').getTable('testTable');

    // The criteria is defined through the expression.
    return table.update().where('name = "bar"').set('age', 50)
        .execute()
        .then(() => {
            return table.select().orderBy('name ASC')
                .execute(row => rows.push(row));
        });
})
.then(() => {
    console.log(rows);
});

Change select box option background color

Here it goes what I've learned about the subject!

The CSS 2 specification did not address the problem of how form elements should be presented to users period!

Read here: smashing magazine

Eventually, you will never find any technical article from w3c or other addressed to this topic. Styling form elements in particular select boxes is not fully supported however, you can drive around... with some effort!

Styling HTML Form Elements

Building Custom Widgets

Don't waste time with hacks e such read the links and learn how pros get the job done!

Run local java applet in browser (chrome/firefox) "Your security settings have blocked a local application from running"

In my case, this has been resolved by going to control panel > java > security > then add url in the exception site list. Then apply. Test again the site and it should now allow you to run the local java.

Difference in boto3 between resource, client, and session?

Here's some more detailed information on what Client, Resource, and Session are all about.

Client:

  • low-level AWS service access
  • generated from AWS service description
  • exposes botocore client to the developer
  • typically maps 1:1 with the AWS service API
  • all AWS service operations are supported by clients
  • snake-cased method names (e.g. ListBuckets API => list_buckets method)

Here's an example of client-level access to an S3 bucket's objects (at most 1000**):

import boto3

client = boto3.client('s3')
response = client.list_objects_v2(Bucket='mybucket')
for content in response['Contents']:
    obj_dict = client.get_object(Bucket='mybucket', Key=content['Key'])
    print(content['Key'], obj_dict['LastModified'])

** you would have to use a paginator, or implement your own loop, calling list_objects() repeatedly with a continuation marker if there were more than 1000.

Resource:

  • higher-level, object-oriented API
  • generated from resource description
  • uses identifiers and attributes
  • has actions (operations on resources)
  • exposes subresources and collections of AWS resources
  • does not provide 100% API coverage of AWS services

Here's the equivalent example using resource-level access to an S3 bucket's objects (all):

import boto3

s3 = boto3.resource('s3')
bucket = s3.Bucket('mybucket')
for obj in bucket.objects.all():
    print(obj.key, obj.last_modified)

Note that in this case you do not have to make a second API call to get the objects; they're available to you as a collection on the bucket. These collections of subresources are lazily-loaded.

You can see that the Resource version of the code is much simpler, more compact, and has more capability (it does pagination for you). The Client version of the code would actually be more complicated than shown above if you wanted to include pagination.

Session:

  • stores configuration information (primarily credentials and selected region)
  • allows you to create service clients and resources
  • boto3 creates a default session for you when needed

A useful resource to learn more about these boto3 concepts is the introductory re:Invent video.

EditText non editable

android:editable="false" should work, but it is deprecated, you should be using android:inputType="none" instead.

Alternatively, if you want to do it in the code you could do this :

EditText mEdit = (EditText) findViewById(R.id.yourid);
mEdit.setEnabled(false);

This is also a viable alternative :

EditText mEdit = (EditText) findViewById(R.id.yourid);
mEdit.setKeyListener(null);

If you're going to make your EditText non-editable, may I suggest using the TextView widget instead of the EditText, since using a EditText seems kind of pointless in that case.

EDIT: Altered some information since I've found that android:editable is deprecated, and you should use android:inputType="none", but there is a bug about it on android code; So please check this.

What does '<?=' mean in PHP?

=> is the separator for associative arrays. In the context of that foreach loop, it assigns the key of the array to $user and the value to $pass.

Example:

$user_list = array(
    'dave' => 'apassword',
    'steve' => 'secr3t'
);

foreach ($user_list as $user => $pass) {
    echo "{$user}'s pass is: {$pass}\n";
}
// Prints: 
// "dave's pass is: apassword"
// "steve's pass is: secr3t"

Note that this can be used for numerically indexed arrays too.

Example:

$foo = array('car', 'truck', 'van', 'bike', 'rickshaw');
foreach ($foo as $i => $type) {
    echo "{$i}: {$type}\n";
}
// prints:
// 0: car
// 1: truck
// 2: van
// 3: bike
// 4: rickshaw

Android, getting resource ID from string?

Since you said you only wanted to pass one parameter and it did not seem to matter which, you could pass the resource identifier in and then find out the string name for it, thus:

String name = getResources().getResourceEntryName(id);

This might be the most efficient way of obtaining both values. You don't have to mess around finding just the "icon" part from a longer string.

How to declare and add items to an array in Python?

Arrays (called list in python) use the [] notation. {} is for dict (also called hash tables, associated arrays, etc in other languages) so you won't have 'append' for a dict.

If you actually want an array (list), use:

array = []
array.append(valueToBeInserted)

JavaScript single line 'if' statement - best syntax, this alternative?

This one line is much cleaner.

if(dog) alert('bark bark');

I prefer this. hope it helps someone

Excel Reference To Current Cell

Without INDIRECT(): =CELL("width", OFFSET($A$1,ROW()-1,COLUMN()-1) )

Right HTTP status code to wrong input

409 Conflict could be an acceptable solution.

According to: https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html

The request could not be completed due to a conflict with the current state of the resource. This code is only allowed in situations where it is expected that the user might be able to resolve the conflict and resubmit the request. The response body SHOULD include enough information for the user to recognize the source of the conflict. Ideally, the response entity would include enough information for the user or user agent to fix the problem; however, that might not be possible and is not required.

The doc continues with an example:

Conflicts are most likely to occur in response to a PUT request. For example, if versioning were being used and the entity being PUT included changes to a resource which conflict with those made by an earlier (third-party) request, the server might use the 409 response to indicate that it can't complete the request. In this case, the response entity would likely contain a list of the differences between the two versions in a format defined by the response Content-Type.


In my case, I would like to PUT a string, that must be unique, to a database via an API. Before adding it to the database, I am checking that it is not already in the database.

If it is, I will return "Error: The string is already in the database", 409.

I believe this is what the OP wanted: an error code suitable for when the data does not pass the server's criteria.

How to enable authentication on MongoDB through Docker?

I want to comment but don't have enough reputation.

The user-adding executable script shown above has to be modified with --authenticationDatabase admin and NEWDATABASENAME.

mongo --authenticationDatabase admin --host localhost -u USER_PREVIOUSLY_DEFINED -p PASS_YOU_PREVIOUSLY_DEFINED NEWDATABASENAME --eval "db.createUser({user: 'NEWUSERNAME', pwd: 'PASSWORD', roles: [{role: 'readWrite', db: 'NEWDATABASENAME'}]});"

https://i.stack.imgur.com/MdyXo.png

GIT: Checkout to a specific folder

The above solutions didn't work for me because I needed to check out a specific tagged version of the tree. That's how cvs export is meant to be used, by the way. git checkout-index doesn't take the tag argument, as it checks out files from index. git checkout <tag> would change the index regardless of the work tree, so I would need to reset the original tree. The solution that worked for me was to clone the repository. Shared clone is quite fast and doesn't take much extra space. The .git directory can be removed if desired.

git clone --shared --no-checkout <repository> <destination>
cd <destination>
git checkout <tag>
rm -rf .git

Newer versions of git should support git clone --branch <tag> to check out the specified tag automatically:

git clone --shared --branch <tag> <repository> <destination>
rm -rf <destination>/.git

How to Find Item in Dictionary Collection?

It's possible to find the element in Dictionary collection by using ContainsKey or TryGetValue as follows:

class Program
{
    protected static Dictionary<string, string> _tags = new Dictionary<string,string>();

    static void Main(string[] args)
    {
        string strValue;

        _tags.Add("101", "C#");
        _tags.Add("102", "ASP.NET");

        if (_tags.ContainsKey("101"))
        {
            strValue = _tags["101"];
            Console.WriteLine(strValue);
        }

        if (_tags.TryGetValue("101", out strValue))
        {
            Console.WriteLine(strValue);
        }
    }
}

Preferred way to create a Scala list

To create a list of string, use the following:

val l = List("is", "am", "are", "if")

How to write UTF-8 in a CSV file

From your shell run:

pip2 install unicodecsv

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

Is it better to use std::memcpy() or std::copy() in terms to performance?

Profiling shows that statement: std::copy() is always as fast as memcpy() or faster is false.

My system:

HP-Compaq-dx7500-Microtower 3.13.0-24-generic #47-Ubuntu SMP Fri May 2 23:30:00 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux.

gcc (Ubuntu 4.8.2-19ubuntu1) 4.8.2

The code (language: c++):

    const uint32_t arr_size = (1080 * 720 * 3); //HD image in rgb24
    const uint32_t iterations = 100000;
    uint8_t arr1[arr_size];
    uint8_t arr2[arr_size];
    std::vector<uint8_t> v;

    main(){
        {
            DPROFILE;
            memcpy(arr1, arr2, sizeof(arr1));
            printf("memcpy()\n");
        }

        v.reserve(sizeof(arr1));
        {
            DPROFILE;
            std::copy(arr1, arr1 + sizeof(arr1), v.begin());
            printf("std::copy()\n");
        }

        {
            time_t t = time(NULL);
            for(uint32_t i = 0; i < iterations; ++i)
                memcpy(arr1, arr2, sizeof(arr1));
            printf("memcpy()    elapsed %d s\n", time(NULL) - t);
        }

        {
            time_t t = time(NULL);
            for(uint32_t i = 0; i < iterations; ++i)
                std::copy(arr1, arr1 + sizeof(arr1), v.begin());
            printf("std::copy() elapsed %d s\n", time(NULL) - t);
        }
    }

g++ -O0 -o test_stdcopy test_stdcopy.cpp

memcpy() profile: main:21: now:1422969084:04859 elapsed:2650 us
std::copy() profile: main:27: now:1422969084:04862 elapsed:2745 us
memcpy() elapsed 44 s std::copy() elapsed 45 s

g++ -O3 -o test_stdcopy test_stdcopy.cpp

memcpy() profile: main:21: now:1422969601:04939 elapsed:2385 us
std::copy() profile: main:28: now:1422969601:04941 elapsed:2690 us
memcpy() elapsed 27 s std::copy() elapsed 43 s

Red Alert pointed out that the code uses memcpy from array to array and std::copy from array to vector. That coud be a reason for faster memcpy.

Since there is

v.reserve(sizeof(arr1));

there shall be no difference in copy to vector or array.

The code is fixed to use array for both cases. memcpy still faster:

{
    time_t t = time(NULL);
    for(uint32_t i = 0; i < iterations; ++i)
        memcpy(arr1, arr2, sizeof(arr1));
    printf("memcpy()    elapsed %ld s\n", time(NULL) - t);
}

{
    time_t t = time(NULL);
    for(uint32_t i = 0; i < iterations; ++i)
        std::copy(arr1, arr1 + sizeof(arr1), arr2);
    printf("std::copy() elapsed %ld s\n", time(NULL) - t);
}

memcpy()    elapsed 44 s
std::copy() elapsed 48 s 

How do I assign ls to an array in Linux Bash?

This would print the files in those directories line by line.

array=(ww/* ee/* qq/*)
printf "%s\n" "${array[@]}"

float:left; vs display:inline; vs display:inline-block; vs display:table-cell;

For the record only, to add to Spudley's answer, there is also the possibility to use position: absolute and margins if you know the column widths.

For me, the main issue when chossing a method is whether you need the columns to fill the whole height (equal heights), where table-cell is the easiest method (if you don't care much for older browsers).

Get the cartesian product of a series of lists?

For Python 2.5 and older:

>>> [(a, b, c) for a in [1,2,3] for b in ['a','b'] for c in [4,5]]
[(1, 'a', 4), (1, 'a', 5), (1, 'b', 4), (1, 'b', 5), (2, 'a', 4), 
 (2, 'a', 5), (2, 'b', 4), (2, 'b', 5), (3, 'a', 4), (3, 'a', 5), 
 (3, 'b', 4), (3, 'b', 5)]

Here's a recursive version of product() (just an illustration):

def product(*args):
    if not args:
        return iter(((),)) # yield tuple()
    return (items + (item,) 
            for items in product(*args[:-1]) for item in args[-1])

Example:

>>> list(product([1,2,3], ['a','b'], [4,5])) 
[(1, 'a', 4), (1, 'a', 5), (1, 'b', 4), (1, 'b', 5), (2, 'a', 4), 
 (2, 'a', 5), (2, 'b', 4), (2, 'b', 5), (3, 'a', 4), (3, 'a', 5), 
 (3, 'b', 4), (3, 'b', 5)]
>>> list(product([1,2,3]))
[(1,), (2,), (3,)]
>>> list(product([]))
[]
>>> list(product())
[()]

How do I put a variable inside a string?

With the introduction of formatted string literals ("f-strings" for short) in Python 3.6, it is now possible to write this with a briefer syntax:

>>> name = "Fred"
>>> f"He said his name is {name}."
'He said his name is Fred.'

With the example given in the question, it would look like this

plot.savefig(f'hanning{num}.pdf')

How to solve SyntaxError on autogenerated manage.py?

What am I wondering is though the django is installed to the container it may not be in the host machine where you are running the command. Then how will the command run. So since no above solutions worked for me.

I found out the running container and get into the running container using docker exec -it <container> bash then ran the command inside docker container. As we have the volumed container the changes done will also reflect locally. What ever command is to be run can be run inside the running container

Python:Efficient way to check if dictionary is empty or not

Here is another way to do it:

isempty = (dict1 and True) or False

if dict1 is empty then dict1 and True will give {} and this when resolved with False gives False.

if dict1 is non-empty then dict1 and True gives True and this resolved with False gives True

HTML anchor tag with Javascript onclick event

If your onclick function returns false the default browser behaviour is cancelled. As such:

<a href='http://www.google.com' onclick='return check()'>check</a>

<script type='text/javascript'>

function check()
{
    return false;
}

</script>

Either way, whether google does it or not isn't of much importance. It's cleaner to bind your onclick functions within javascript - this way you separate your HTML from other code.

How can I find the number of years between two dates?

If you don't want to calculate it using java's Calendar you can use Androids Time class It is supposed to be faster but I didn't notice much difference when i switched.

I could not find any pre-defined functions to determine time between 2 dates for an age in Android. There are some nice helper functions to get formatted time between dates in the DateUtils but that's probably not what you want.

Android: Rotate image in imageview by an angle

try this on a custom view

public class DrawView extends View {


    public DrawView(Context context,AttributeSet attributeSet){
        super(context, attributeSet);
    }

    @Override
    public void onDraw(Canvas canvas) {
        /*Canvas c=new Canvas(BitmapFactory.decodeResource(getResources(), R.drawable.new_minute1)    );

        c.rotate(45);*/

        canvas.drawBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.new_minute1), 0, 0, null);
        canvas.rotate(45);
    }
}

Batch file to perform start, run, %TEMP% and delete all

del won't trigger any dialogs or message boxes. You have a few problems, though:

  1. start will just open Explorer which would be useless. You need cd to change the working directory of your batch file (the /D is there so it also works when run from a different drive):

    cd /D %temp%
    
  2. You may want to delete directories as well:

    for /d %%D in (*) do rd /s /q "%%D"
    
  3. You need to skip the question for del and remove read-only files too:

    del /f /q *
    

so you arrive at:

@echo off
cd /D %temp%
for /d %%D in (*) do rd /s /q "%%D"
del /f /q *

Where will log4net create this log file?

if you want to choose dynamically the path to the log file use the method written in this link: method to dynamic choose the log file path.

if you want you can set the path to where your app EXE file exists like this -

var logFileLocation = System.IO.Path.GetDirectoryName
(System.Reflection.Assembly.GetEntryAssembly().Location);

and then send this 'logFileLocation' to the method written in the link above like this:

Initialize(logFileLocation);

and you are ready to go! :)

Uncaught TypeError: undefined is not a function on loading jquery-min.js

I had this problem recently with the jQuery Validation plug-in, using Squishit, also getting the js error:

"undefined is not a function"

I fixed it by changing the reference to the unminified jquery.validate.js file, rather than jquery.validate.min.js.

@MvcHtmlString.Create(
    @SquishIt.Framework.Bundle.JavaScript()
        .Add("~/Scripts/Libraries/jquery-1.8.2.min.js")
        .Add("~/Scripts/Libraries/jquery-ui-1.9.1.custom.min.js")
        .Add("~/Scripts/Libraries/jquery.unobtrusive-ajax.min.js")
        .Add("~/Scripts/Libraries/jquery.validate.js")
        .Add("~/Scripts/Libraries/jquery.validate.unobtrusive.js")
         ... more files

I think that the minified version of certain files, when further compressed using Squishit, for example, might in some cases not deal with missing semi-colons and the like, as @Dustin suggests, so you might have to experiment with which files you can doubly compress, and which you just leave to Squishit or whatever you're bundling with.

Python find min max and average of a list (array)

Return min and max value in tuple:

def side_values(num_list):
    results_list = sorted(num_list)
    return results_list[0], results_list[-1]


somelist = side_values([1,12,2,53,23,6,17])
print(somelist)

No Multiline Lambda in Python: Why not?

You can simply use slash (\) if you have multiple lines for your lambda function

Example:

mx = lambda x, y: x if x > y \
     else y
print(mx(30, 20))

Output: 30

How can I tell where mongoDB is storing data? (its not in the default /data/db!)

For windows Go inside MongoDB\Server\4.0\bin folder and open mongod.cfg file in any text editor. Then locate the line that specifies the dbPath param. The line looks something similar

dbPath: D:\Program Files\MongoDB\Server\4.0\data

How to access SOAP services from iPhone

One word: Don't.

OK obviously that isn't a real answer. But still SOAP should be avoided at all costs. ;-) Is it possible to add a proxy server between the iPhone and the web service? Perhaps something that converts REST into SOAP for you?

You could try CSOAP, a SOAP library that depends on libxml2 (which is included in the iPhone SDK).

I've written my own SOAP framework for OSX. However it is not actively maintained and will require some time to port to the iPhone (you'll need to replace NSXML with TouchXML for a start)

How do I convert Int/Decimal to float in C#?

You don't even need to cast, it is implicit.

int i = 3;

float f = i;

A full list/table of implicit numeric conversions can be seen here http://msdn.microsoft.com/en-us/library/y5b434w4.aspx

How can I add raw data body to an axios request?

Here is my solution:

axios({
  method: "POST",
  url: "https://URL.com/api/services/fetchQuizList",
  headers: {
    "x-access-key": data,
    "x-access-token": token,
  },
  data: {
    quiz_name: quizname,
  },
})
.then(res => {
  console.log("res", res.data.message);
})
.catch(err => {
  console.log("error in request", err);
});

This should help

Apache Spark: map vs mapPartitions?

Map :

  1. It processes one row at a time , very similar to map() method of MapReduce.
  2. You return from the transformation after every row.

MapPartitions

  1. It processes the complete partition in one go.
  2. You can return from the function only once after processing the whole partition.
  3. All intermediate results needs to be held in memory till you process the whole partition.
  4. Provides you like setup() map() and cleanup() function of MapReduce

Map Vs mapPartitions http://bytepadding.com/big-data/spark/spark-map-vs-mappartitions/

Spark Map http://bytepadding.com/big-data/spark/spark-map/

Spark mapPartitions http://bytepadding.com/big-data/spark/spark-mappartitions/

SQL 'LIKE' query using '%' where the search criteria contains '%'

Escape the percent sign \% to make it part of your comparison value.

How can I auto increment the C# assembly version via our CI platform (Hudson)?

A simple alternative is to let the C# environment increment the assembly version for you by setting the version attribute to major.minor.* (as described in the AssemblyInfo file template.)

You may be looking for a more comprehensive solution, though.

EDIT (Response to the question in a comment):

From AssemblyInfo.cs:

// Version information for an assembly consists of the following four values:
//
//      Major Version
//      Minor Version 
//      Build Number
//      Revision
//
// You can specify all the values or you can default the Build and Revision Numbers 
// by using the '*' as shown below:
// [assembly: AssemblyVersion("1.0.*")]

How to update the value of a key in a dictionary in Python?

n = eval(input('Num books: '))
books = {}
for i in range(n):
    titlez = input("Enter Title: ")
    copy = eval(input("Num of copies: "))
    books[titlez] = copy

prob = input('Sell a book; enter YES or NO: ')
if prob == 'YES' or 'yes':
    choice = input('Enter book title: ')
    if choice in books:
        init_num = books[choice]
        init_num -= 1
        books[choice] = init_num
        print(books)

Convert list to tuple in Python

Expanding on eumiro's comment, normally tuple(l) will convert a list l into a tuple:

In [1]: l = [4,5,6]

In [2]: tuple
Out[2]: <type 'tuple'>

In [3]: tuple(l)
Out[3]: (4, 5, 6)

However, if you've redefined tuple to be a tuple rather than the type tuple:

In [4]: tuple = tuple(l)

In [5]: tuple
Out[5]: (4, 5, 6)

then you get a TypeError since the tuple itself is not callable:

In [6]: tuple(l)
TypeError: 'tuple' object is not callable

You can recover the original definition for tuple by quitting and restarting your interpreter, or (thanks to @glglgl):

In [6]: del tuple

In [7]: tuple
Out[7]: <type 'tuple'>

CSS Select box arrow style

Try to replace the

padding: 2px 30px 2px 2px;

with

padding: 2px 2px 2px 2px;

It should work.

location.host vs location.hostname and cross-browser compatibility?

Your primary question has been answered above. I just wanted to point out that the regex you're using has a bug. It will also succeed on foo-domain.com which is not a subdomain of domain.com

What you really want is this:

/(^|\.)domain\.com$/

Background color of text in SVG

No, you can not add background color to SVG elements. You can do it programmatically with d3.

var text = d3.select("text");
var bbox = text.node().getBBox();
var padding = 2;
var rect = self.svg.insert("rect", "text")
    .attr("x", bbox.x - padding)
    .attr("y", bbox.y - padding)
    .attr("width", bbox.width + (padding*2))
    .attr("height", bbox.height + (padding*2))
    .style("fill", "red");

Make the current commit the only (initial) commit in a Git repository?

I solved a similar issue by just deleting the .git folder from my project and reintegrating with version control through IntelliJ. Note: The .git folder is hidden. You can view it in the terminal with ls -a , and then remove it using rm -rf .git .

Insert multiple rows WITHOUT repeating the "INSERT INTO ..." part of the statement?

You can use a union:

INSERT INTO dbo.MyTable (ID, Name) 
SELECT ID, Name FROM (
    SELECT 123, 'Timmy'
    UNION ALL
    SELECT 124, 'Jonny'
    UNION ALL
    SELECT 125, 'Sally'
) AS X (ID, Name)

Convert String to SecureString

Here is a cheap linq trick.

            SecureString sec = new SecureString();
            string pwd = "abc123"; /* Not Secure! */
            pwd.ToCharArray().ToList().ForEach(sec.AppendChar);
            /* and now : seal the deal */
            sec.MakeReadOnly();

notifyDataSetChange not working from custom adapter

Maybe try to refresh your ListView:

receiptsListView.invalidate().

EDIT: Another thought came into my mind. Just for the record, try to disable list view cache:

<ListView
    ...
    android:scrollingCache="false"
    android:cacheColorHint="@android:color/transparent"
    ... />

Java error: Comparison method violates its general contract

It also has something to do with the version of JDK. If it does well in JDK6, maybe it will have the problem in JDK 7 described by you, because the implementation method in jdk 7 has been changed.

Look at this:

Description: The sorting algorithm used by java.util.Arrays.sort and (indirectly) by java.util.Collections.sort has been replaced. The new sort implementation may throw an IllegalArgumentException if it detects a Comparable that violates the Comparable contract. The previous implementation silently ignored such a situation. If the previous behavior is desired, you can use the new system property, java.util.Arrays.useLegacyMergeSort, to restore previous mergesort behaviour.

I don't know the exact reason. However, if you add the code before you use sort. It will be OK.

System.setProperty("java.util.Arrays.useLegacyMergeSort", "true");

How to handle-escape both single and double quotes in an SQL-Update statement

Depending on what language you are programming in, you can use a function to replace double quotes with two double quotes.

For example in PHP that would be:

str_replace('"', '""', $string);

If you are trying to do that using SQL only, maybe REPLACE() is what you are looking for.

So your query would look something like this:

"UPDATE Table SET columnname = '" & REPLACE(@wstring, '"', '""') & "' where ... blah ... blah "

Passing html values into javascript functions

Simply put id attribute in your input text field -

<input type="text" maxlength="3" name="value" id="value" />

validate a dropdownlist in asp.net mvc

I just can't believe that there are people still using ViewData/ViewBag in ASP.NET MVC 3 instead of having strongly typed views and view models:

public class MyViewModel
{
    [Required]
    public string CategoryId { get; set; }

    public IEnumerable<Category> Categories { get; set; }
}

and in your controller:

public class HomeController: Controller
{
    public ActionResult Index()
    {
        var model = new MyViewModel
        {
            Categories = Repository.GetCategories()
        }
        return View(model);
    }

    [HttpPost]
    public ActionResult Index(MyViewModel model)
    {
        if (!ModelState.IsValid)
        {
            // there was a validation error =>
            // rebind categories and redisplay view
            model.Categories = Repository.GetCategories();
            return View(model);
        }
        // At this stage the model is OK => do something with the selected category
        return RedirectToAction("Success");
    }
}

and then in your strongly typed view:

@Html.DropDownListFor(
    x => x.CategoryId, 
    new SelectList(Model.Categories, "ID", "CategoryName"), 
    "-- Please select a category --"
)
@Html.ValidationMessageFor(x => x.CategoryId)

Also if you want client side validation don't forget to reference the necessary scripts:

<script src="@Url.Content("~/Scripts/jquery.validate.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.js")" type="text/javascript"></script>

MySQL GROUP BY two columns

First, let's make some test data:

create table client (client_id integer not null primary key auto_increment,
                     name varchar(64));
create table portfolio (portfolio_id integer not null primary key auto_increment,
                        client_id integer references client.id,
                        cash decimal(10,2),
                        stocks decimal(10,2));
insert into client (name) values ('John Doe'), ('Jane Doe');
insert into portfolio (client_id, cash, stocks) values (1, 11.11, 22.22),
                                                       (1, 10.11, 23.22),
                                                       (2, 30.30, 40.40),
                                                       (2, 40.40, 50.50);

If you didn't need the portfolio ID, it would be easy:

select client_id, name, max(cash + stocks)
from client join portfolio using (client_id)
group by client_id

+-----------+----------+--------------------+
| client_id | name     | max(cash + stocks) |
+-----------+----------+--------------------+
|         1 | John Doe |              33.33 | 
|         2 | Jane Doe |              90.90 | 
+-----------+----------+--------------------+

Since you need the portfolio ID, things get more complicated. Let's do it in steps. First, we'll write a subquery that returns the maximal portfolio value for each client:

select client_id, max(cash + stocks) as maxtotal
from portfolio
group by client_id

+-----------+----------+
| client_id | maxtotal |
+-----------+----------+
|         1 |    33.33 | 
|         2 |    90.90 | 
+-----------+----------+

Then we'll query the portfolio table, but use a join to the previous subquery in order to keep only those portfolios the total value of which is the maximal for the client:

 select portfolio_id, cash + stocks from portfolio 
 join (select client_id, max(cash + stocks) as maxtotal 
       from portfolio
       group by client_id) as maxima
 using (client_id)
 where cash + stocks = maxtotal

+--------------+---------------+
| portfolio_id | cash + stocks |
+--------------+---------------+
|            5 |         33.33 | 
|            6 |         33.33 | 
|            8 |         90.90 | 
+--------------+---------------+

Finally, we can join to the client table (as you did) in order to include the name of each client:

select client_id, name, portfolio_id, cash + stocks
from client
join portfolio using (client_id)
join (select client_id, max(cash + stocks) as maxtotal
      from portfolio 
      group by client_id) as maxima
using (client_id)
where cash + stocks = maxtotal

+-----------+----------+--------------+---------------+
| client_id | name     | portfolio_id | cash + stocks |
+-----------+----------+--------------+---------------+
|         1 | John Doe |            5 |         33.33 | 
|         1 | John Doe |            6 |         33.33 | 
|         2 | Jane Doe |            8 |         90.90 | 
+-----------+----------+--------------+---------------+

Note that this returns two rows for John Doe because he has two portfolios with the exact same total value. To avoid this and pick an arbitrary top portfolio, tag on a GROUP BY clause:

select client_id, name, portfolio_id, cash + stocks
from client
join portfolio using (client_id)
join (select client_id, max(cash + stocks) as maxtotal
      from portfolio 
      group by client_id) as maxima
using (client_id)
where cash + stocks = maxtotal
group by client_id, cash + stocks

+-----------+----------+--------------+---------------+
| client_id | name     | portfolio_id | cash + stocks |
+-----------+----------+--------------+---------------+
|         1 | John Doe |            5 |         33.33 | 
|         2 | Jane Doe |            8 |         90.90 | 
+-----------+----------+--------------+---------------+

How do you remove columns from a data.frame?

For the kinds of large files I tend to get, I generally wouldn't even do this in R. I would use the cut command in Linux to process data before it gets to R. This isn't a critique of R, just a preference for using some very basic Linux tools like grep, tr, cut, sort, uniq, and occasionally sed & awk (or Perl) when there's something to be done about regular expressions.

Another reason to use standard GNU commands is that I can pass them back to the source of the data and ask that they prefilter the data so that I don't get extraneous data. Most of my colleagues are competent with Linux, fewer know R.

(Updated) A method that I would like to use before long is to pair mmap with a text file and examine the data in situ, rather than read it at all into RAM. I have done this with C, and it can be blisteringly fast.

Batch File; List files in directory, only filenames?

You can also try this:

for %%a in (*) do echo %%a

Using a for loop, you can echo out all the file names of the current directory.

To print them directly from the console:

for %a in (*) do @echo %a

How to get all the AD groups for a particular user?

If you have a LDAP connection with a username and password to connect to Active Directory, here is the code I used to connect properly:

using System.DirectoryServices.AccountManagement;

// ...

// Connection information
var connectionString = "LDAP://domain.com/DC=domain,DC=com";
var connectionUsername = "your_ad_username";
var connectionPassword = "your_ad_password";

// Get groups for this user
var username = "myusername";

// Split the LDAP Uri
var uri = new Uri(connectionString);
var host = uri.Host;
var container = uri.Segments.Count() >=1 ? uri.Segments[1] : "";

// Create context to connect to AD
var princContext = new PrincipalContext(ContextType.Domain, host, container, connectionUsername, connectionPassword);

// Get User
UserPrincipal user = UserPrincipal.FindByIdentity(princContext, IdentityType.SamAccountName, username);

// Browse user's groups
foreach (GroupPrincipal group in user.GetGroups())
{
    Console.Out.WriteLine(group.Name);
}

Different ways of clearing lists

Clearing a list in place will affect all other references of the same list.

For example, this method doesn't affect other references:

>>> a = [1, 2, 3]
>>> b = a
>>> a = []
>>> print(a)
[]
>>> print(b)
[1, 2, 3]

But this one does:

>>> a = [1, 2, 3]
>>> b = a
>>> del a[:]      # equivalent to   del a[0:len(a)]
>>> print(a)
[]
>>> print(b)
[]
>>> a is b
True

You could also do:

>>> a[:] = []

JavaScript alert box with timer

If you are looking for an alert that dissapears after an interval you could try the jQuery UI Dialog widget.

TypeError: worker() takes 0 positional arguments but 1 was given

class KeyStatisticCollection(DataDownloadUtilities.DataDownloadCollection):
def GenerateAddressStrings(self):
    pass    
def worker(self):
    pass
def DownloadProc(self):
    pass

How to check if running in Cygwin, Mac or Linux?

# This script fragment emits Cygwin rulez under bash/cygwin
if [[ $(uname -s) == CYGWIN* ]];then
    echo Cygwin rulez
else 
    echo Unix is king
fi

If the 6 first chars of uname -s command is "CYGWIN", a cygwin system is assumed

Go / golang time.Now().UnixNano() convert to milliseconds?

As @Jono points out in @OneOfOne's answer, the correct answer should take into account the duration of a nanosecond. Eg:

func makeTimestamp() int64 {
    return time.Now().UnixNano() / (int64(time.Millisecond)/int64(time.Nanosecond))
}

OneOfOne's answer works because time.Nanosecond happens to be 1, and dividing by 1 has no effect. I don't know enough about go to know how likely this is to change in the future, but for the strictly correct answer I would use this function, not OneOfOne's answer. I doubt there is any performance disadvantage as the compiler should be able to optimize this perfectly well.

See https://en.wikipedia.org/wiki/Dimensional_analysis

Another way of looking at this is that both time.Now().UnixNano() and time.Millisecond use the same units (Nanoseconds). As long as that is true, OneOfOne's answer should work perfectly well.

how to use json file in html code

use jQuery's $.getJSON

$.getJSON('mydata.json', function(data) {
    //do stuff with your data here
});

Set selected option of select box

My problem

get_courses(); //// To load the course list
$("#course").val(course); //// Setting default value of the list

I had the same issue . The Only difference from your code is that I was loading the select box through an ajax call and soon as the ajax call was executed I had set the default value of the select box

The Solution

get_courses();
   setTimeout(function() {
     $("#course").val(course);
  }, 10);

Converting a pointer into an integer

Since uintptr_t is not guaranteed to be there in C++/C++11, if this is a one way conversion you can consider uintmax_t, always defined in <cstdint>.

auto real_param = reinterpret_cast<uintmax_t>(param);

To play safe, one could add anywhere in the code an assertion:

static_assert(sizeof (uintmax_t) >= sizeof (void *) ,
              "No suitable integer type for conversion from pointer type");

Using LIMIT within GROUP BY to get N results per group?

Took some working, but I thougth my solution would be something to share as it is seems elegant as well as quite fast.

SELECT h.year, h.id, h.rate 
  FROM (
    SELECT id, 
      SUBSTRING_INDEX(GROUP_CONCAT(CONCAT(id, '-', year) ORDER BY rate DESC), ',' , 5) AS l
      FROM h
      WHERE year BETWEEN 2000 AND 2009
      GROUP BY id
      ORDER BY id
  ) AS h_temp
    LEFT JOIN h ON h.id = h_temp.id 
      AND SUBSTRING_INDEX(h_temp.l, CONCAT(h.id, '-', h.year), 1) != h_temp.l

Note that this example is specified for the purpose of the question and can be modified quite easily for other similar purposes.

ImportError: No module named requests

I solved this problem.You can try this method. In this file '.bash_profile', Add codes like alias python=/Library/Frameworks/Python.framework/Versions/2.7/bin/python2.7

How to find memory leak in a C++ code/project?

Answering the second part of your question,

Is there any standard or procedure one should follow to ensure there is no memory leak in the program.

Yes, there is. And this is one of the key differences between C and C++.

In C++, you should never call new or delete in your user code. RAII is a very commonly used technique, which pretty much solves the resource management problem. Every resource in your program (a resource is anything that has to be acquired, and then later on, released: file handles, network sockets, database connections, but also plain memory allocations, and in some cases, pairs of API calls (BeginX()/EndX(), LockY(), UnlockY()), should be wrapped in a class, where:

  • the constructor acquires the resource (by calling new if the resource is a memroy allocation)
  • the destructor releases the resource,
  • copying and assignment is either prevented (by making the copy constructor and assignment operators private), or are implemented to work correctly (for example by cloning the underlying resource)

This class is then instantiated locally, on the stack, or as a class member, and not by calling new and storing a pointer.

You often don't need to define these classes yourself. The standard library containers behave in this way as well, so that any object stored into a std::vector gets freed when the vector is destroyed. So again, don't store a pointer into the container (which would require you to call new and delete), but rather the object itself (which gives you memory management for free). Likewise, smart pointer classes can be used to easily wrap objects that just have to be allocated with new, and control their lifetimes.

This means that when the object goes out of scope, it is automatically destroyed, and its resource released and cleaned up.

If you do this consistently throughout your code, you simply won't have any memory leaks. Everything that could get leaked is tied to a destructor which is guaranteed to be called when control leaves the scope in which the object was declared.

How to terminate a thread when main program ends?

If you spawn a Thread like so - myThread = Thread(target = function) - and then do myThread.start(); myThread.join(). When CTRL-C is initiated, the main thread doesn't exit because it is waiting on that blocking myThread.join() call. To fix this, simply put in a timeout on the .join() call. The timeout can be as long as you wish. If you want it to wait indefinitely, just put in a really long timeout, like 99999. It's also good practice to do myThread.daemon = True so all the threads exit when the main thread(non-daemon) exits.

convert month from name to number

With PHP 5.4, you can turn Matthew's answer into a one-liner:

$date = sprintf('%d-%d-01', $year, date_parse('may')['month']);

Remove Trailing Spaces and Update in Columns in SQL Server

To just trim trailing spaces you should use

UPDATE
    TableName
SET
    ColumnName = RTRIM(ColumnName)

However, if you want to trim all leading and trailing spaces then use this

UPDATE
    TableName
SET
    ColumnName = LTRIM(RTRIM(ColumnName))

How to convert DateTime to/from specific string format (both ways, e.g. given Format is "yyyyMMdd")?

Based on the property names it looks like you are trying to convert a string to a date by assignment:

claimantAuxillaryRecord.TPOCDate2 = tpoc2[0].ToString();

It is probably due to the current UI culture and therefore it cannot interpret the date string correctly when assigned.

Get the ID of a drawable in ImageView

Digging StackOverflow for answers on the similar issue I found people usually suggesting 2 approaches:

  • Load a drawable into memory and compare ConstantState or bitmap itself to other one.
  • Set a tag with drawable id into a view and compare tags when you need that.

Personally, I like the second approach for performance reason but tagging bunch of views with appropriate tags is painful and time consuming. This could be very frustrating in a big project. In my case I need to write a lot of Espresso tests which require comparing TextView drawables, ImageView resources, View background and foreground. A lot of work.

So I eventually came up with a solution to delegate a 'dirty' work to the custom inflater. In every inflated view I search for a specific attributes and and set a tag to the view with a resource id if any is found. This approach is pretty much the same guys from Calligraphy used. I wrote a simple library for that: TagView

If you use it, you can retrieve any of predefined tags, containing drawable resource id that was set in xml layout file:

TagViewUtils.getTag(view, ViewTag.IMAGEVIEW_SRC.id)
TagViewUtils.getTag(view, ViewTag.TEXTVIEW_DRAWABLE_LEFT.id)
TagViewUtils.getTag(view, ViewTag.TEXTVIEW_DRAWABLE_TOP.id)
TagViewUtils.getTag(view, ViewTag.TEXTVIEW_DRAWABLE_RIGHT.id)
TagViewUtils.getTag(view, ViewTag.TEXTVIEW_DRAWABLE_BOTTOM.id)
TagViewUtils.getTag(view, ViewTag.VIEW_BACKGROUND.id)
TagViewUtils.getTag(view, ViewTag.VIEW_FOREGROUND.id)

The library supports any attribute, actually. You can add them manually, just look into the Custom attributes section on Github. If you set a drawable in runtime you can use convenient library methods:

setImageViewResource(ImageView view, int id)

In this case tagging is done for you internally. If you use Kotlin you can write a handy extensions to call view itself. Something like this:

fun ImageView.setImageResourceWithTag(@DrawableRes int id) {
    TagViewUtils.setImageViewResource(this, id)
}

You can find additional info in Tagging in runtime

Downloading a large file using curl

I use this handy function:

By downloading it with a 4094 byte step it will not full your memory

function download($file_source, $file_target) {
    $rh = fopen($file_source, 'rb');
    $wh = fopen($file_target, 'w+b');
    if (!$rh || !$wh) {
        return false;
    }

    while (!feof($rh)) {
        if (fwrite($wh, fread($rh, 4096)) === FALSE) {
            return false;
        }
        echo ' ';
        flush();
    }

    fclose($rh);
    fclose($wh);

    return true;
}

Usage:

     $result = download('http://url','path/local/file');

You can then check if everything is ok with:

     if (!$result)
         throw new Exception('Download error...');

Node.js: Difference between req.query[] and req.params

I want to mention one important note regarding req.query , because currently I am working on pagination functionality based on req.query and I have one interesting example to demonstrate to you...

Example:

// Fetching patients from the database
exports.getPatients = (req, res, next) => {

const pageSize = +req.query.pageSize;
const currentPage = +req.query.currentPage;

const patientQuery = Patient.find();
let fetchedPatients;

// If pageSize and currentPage are not undefined (if they are both set and contain valid values)
if(pageSize && currentPage) {
    /**
     * Construct two different queries 
     * - Fetch all patients 
     * - Adjusted one to only fetch a selected slice of patients for a given page
     */
    patientQuery
        /**
         * This means I will not retrieve all patients I find, but I will skip the first "n" patients
         * For example, if I am on page 2, then I want to skip all patients that were displayed on page 1,
         * 
         * Another example: if I am displaying 7 patients per page , I want to skip 7 items because I am on page 2,
         * so I want to skip (7 * (2 - 1)) => 7 items
         */
        .skip(pageSize * (currentPage - 1))

        /**
         * Narrow dont the amound documents I retreive for the current page
         * Limits the amount of returned documents
         * 
         * For example: If I got 7 items per page, then I want to limit the query to only
         * return 7 items. 
         */
        .limit(pageSize);
}
patientQuery.then(documents => {
    res.status(200).json({
        message: 'Patients fetched successfully',
        patients: documents
    });
  });
};

You will noticed + sign in front of req.query.pageSize and req.query.currentPage

Why? If you delete + in this case, you will get an error, and that error will be thrown because we will use invalid type (with error message 'limit' field must be numeric).

Important: By default if you extracting something from these query parameters, it will always be a string, because it's coming the URL and it's treated as a text.

If we need to work with numbers, and convert query statements from text to number, we can simply add a plus sign in front of statement.

How to convert an image to base64 encoding?

Just in case you are (for whatever reason) unable to use curl nor file_get_contents, you can work around:

$img = imagecreatefrompng('...');
ob_start();
imagepng($img);
$bin = ob_get_clean();
$b64 = base64_encode($bin);

Is there a better way to run a command N times in bash?

Yet another answer: Use parameter expansion on empty parameters:

# calls curl 4 times 
curl -s -w "\n" -X GET "http:{,,,}//www.google.com"

Tested on Centos 7 and MacOS.

Enable tcp\ip remote connections to sql server express already installed database with code or script(query)

I recommend to use SMO (Enable TCP/IP Network Protocol for SQL Server). However, it was not available in my case.

I rewrote the WMI commands from Krzysztof Kozielczyk to PowerShell.

# Enable TCP/IP

Get-CimInstance -Namespace root/Microsoft/SqlServer/ComputerManagement10 -ClassName ServerNetworkProtocol -Filter "InstanceName = 'SQLEXPRESS' and ProtocolName = 'Tcp'" |
Invoke-CimMethod -Name SetEnable

# Open the right ports in the firewall
New-NetFirewallRule -DisplayName 'MSSQL$SQLEXPRESS' -Direction Inbound -Action Allow -Protocol TCP -LocalPort 1433

# Modify TCP/IP properties to enable an IP address

$properties = Get-CimInstance -Namespace root/Microsoft/SqlServer/ComputerManagement10 -ClassName ServerNetworkProtocolProperty -Filter "InstanceName='SQLEXPRESS' and ProtocolName = 'Tcp' and IPAddressName='IPAll'"
$properties | ? { $_.PropertyName -eq 'TcpPort' } | Invoke-CimMethod -Name SetStringValue -Arguments @{ StrValue = '1433' }
$properties | ? { $_.PropertyName -eq 'TcpPortDynamic' } | Invoke-CimMethod -Name SetStringValue -Arguments @{ StrValue = '' }

# Restart SQL Server

Restart-Service 'MSSQL$SQLEXPRESS'

Text not wrapping in p tag

To anyone still struggling, be sure to check and see if you've set a line-height value on the font in question: it could be overriding the word wrap.

Flutter command not found

If your are facing this issue from a Windows 10, that's how i solved this

first of all, find your flutter path, and than your bin folder under de flutter path

e.g. "C:\flutter\bin"

copy it, then pres the windows button, type: environment, and press "Edit the system environment variable"

press "environment variable" button

double click on "Path" menu

Add a new path, using the bin address

e.g ""C:\flutter\bin"

this should work

Read int values from a text file in C

How about this?

fscanf(file,"%d %d %d %d %d %d %d",&line1_1,&line1_2, &line1_3, &line2_1, &line2_2, &line3_1, &line3_2); 

In this case spaces in fscanf match multiple occurrences of any whitespace until the next token in found.

Regular expression to detect semi-colon terminated C++ for & while loops

A little late to the party, but I think regular expressions are not the right tool for the job.

The problem is that you'll come across edge cases which would add extranous complexity to the regular expression. @est mentioned an example line:

for (int i = 0; i < 10; doSomethingTo("("));

This string literal contains an (unbalanced!) parenthesis, which breaks the logic. Apparently, you must ignore contents of string literals. In order to do this, you must take the double quotes into account. But string literals itself can contain double quotes. For instance, try this:

for (int i = 0; i < 10; doSomethingTo("\"(\\"));

If you address this using regular expressions, it'll add even more complexity to your pattern.

I think you are better off parsing the language. You could, for instance, use a language recognition tool like ANTLR. ANTLR is a parser generator tool, which can also generate a parser in Python. You must provide a grammar defining the target language, in your case C++. There are already numerous grammars for many languages out there, so you can just grab the C++ grammar.

Then you can easily walk the parser tree, searching for empty statements as while or for loop body.

A required class was missing while executing org.apache.maven.plugins:maven-war-plugin:2.1.1:war

My solution below is for cases when default maven repositories are not accessible (e.g. due to firewalls).

In case the default repository is not accessible appropriate local <pluginRepository> has to be specified in the settings.xml. If it's the same as your local artifact repository it still needs to be added to the <pluginRepositories> section for plugin jars to be found. Regular <repositories> section is not used to fetch plugin jars.

In my case, however, the issue was caused by the fact that there were multiple plugin repositories defined in that section.

The first repository in the list did not contain the required maven-filtering jar.

I had to change the order of <pluginRepository> definitions to ensure the first one contains maven-filtering.

Changing of repository definitions typically requires to clean ~/.m2/repository and start fresh.

Import-Module : The specified module 'activedirectory' was not loaded because no valid module file was found in any module directory

Even better use implicit remoting to use a module from another Machine!

$s = New-PSSession Server-Name
Invoke-Command -Session $s -ScriptBlock {Import-Module ActiveDirectory}
Import-PSSession -Session $s -Module ActiveDirectory -Prefix REM

This will allow you to use the module off a remote PC for as long as the PSSession is connected.

More Information: https://technet.microsoft.com/en-us/library/ff720181.aspx

Removing elements from an array in C

Interestingly array is randomly accessible by the index. And removing randomly an element may impact the indexes of other elements as well.

    int remove_element(int*from, int total, int index) {
            if((total - index - 1) > 0) {
                      memmove(from+i, from+i+1, sizeof(int)*(total-index-1));
            }
            return total-1; // return the new array size
    }

Note that memcpy will not work in this case because of the overlapping memory.

One of the efficient way (better than memory move) to remove one random element is swapping with the last element.

    int remove_element(int*from, int total, int index) {
            if(index != (total-1))
                    from[index] = from[total-1];
            return total; // **DO NOT DECREASE** the total here
    }

But the order is changed after the removal.

Again if the removal is done in loop operation then the reordering may impact processing. Memory move is one expensive alternative to keep the order while removing an array element. Another of the way to keep the order while in a loop is to defer the removal. It can be done by validity array of the same size.

    int remove_element(int*from, int total, int*is_valid, int index) {
            is_valid[index] = 0;
            return total-1; // return the number of elements
    }

It will create a sparse array. Finally, the sparse array can be made compact(that contains no two valid elements that contain invalid element between them) by doing some reordering.

    int sparse_to_compact(int*arr, int total, int*is_valid) {
            int i = 0;
            int last = total - 1;
            // trim the last invalid elements
            for(; last >= 0 && !is_valid[last]; last--); // trim invalid elements from last

            // now we keep swapping the invalid with last valid element
            for(i=0; i < last; i++) {
                    if(is_valid[i])
                            continue;
                    arr[i] = arr[last]; // swap invalid with the last valid
                    last--;
                    for(; last >= 0 && !is_valid[last]; last--); // trim invalid elements
            }
            return last+1; // return the compact length of the array
    }

How to get a password from a shell script without echoing

One liner:

read -s -p "Password: " password

Under Linux (and cygwin) this form works in bash and sh. It may not be standard Unix sh, though.

For more info and options, in bash, type "help read".

$ help read
read: read [-ers] [-a array] [-d delim] [-i text] [-n nchars] [-N nchars] [-p prompt] [-t timeout] [-u fd] [name ...]
Read a line from the standard input and split it into fields.
  ...
  -p prompt output the string PROMPT without a trailing newline before
            attempting to read
  ...
  -s                do not echo input coming from a terminal

How to see if a directory exists or not in Perl?

Use -d (full list of file tests)

if (-d "cgi-bin") {
    # directory called cgi-bin exists
}
elsif (-e "cgi-bin") {
    # cgi-bin exists but is not a directory
}
else {
    # nothing called cgi-bin exists
}

As a note, -e doesn't distinguish between files and directories. To check if something exists and is a plain file, use -f.

What's the best way to loop through a set of elements in JavaScript?

I know this question is old -- but here's another, extremely simple solution ...

var elements = Array.from(document.querySelectorAll("div"));

Then it can be used like any, standard array.

Using jQuery to programmatically click an <a> link

window.location = document.getElementById('myAnchor').href

How to disable HTML button using JavaScript?

It's still an attribute. Setting it to:

<input type="button" name=myButton value="disable" disabled="disabled">

... is valid.

CSS force image resize and keep aspect ratio

The solutions below will allow scaling up and scaling down of the image, depending on the parent box width.

All images have a parent container with a fixed width for demonstration purposes only. In production, this will be the width of the parent box.

Best Practice (2018):

This solution tells the browser to render the image with max available width and adjust the height as a percentage of that width.

_x000D_
_x000D_
.parent {_x000D_
  width: 100px;_x000D_
}_x000D_
_x000D_
img {_x000D_
  display: block;_x000D_
  width: 100%;_x000D_
  height: auto;_x000D_
}
_x000D_
<p>This image is originally 400x400 pixels, but should get resized by the CSS:</p>_x000D_
<div class="parent">_x000D_
  <img width="400" height="400" src="https://placehold.it/400x400">_x000D_
</div>
_x000D_
_x000D_
_x000D_

Fancier Solution:

With the fancier solution, you'll be able to crop the image regardless of its size and add a background color to compensate for the cropping.

_x000D_
_x000D_
.parent {_x000D_
  width: 100px;_x000D_
}_x000D_
_x000D_
.container {_x000D_
  display: block;_x000D_
  width: 100%;_x000D_
  height: auto;_x000D_
  position: relative;_x000D_
  overflow: hidden;_x000D_
  padding: 34.37% 0 0 0; /* 34.37% = 100 / (w / h) = 100 / (640 / 220) */_x000D_
}_x000D_
_x000D_
.container img {_x000D_
  display: block;_x000D_
  max-width: 100%;_x000D_
  max-height: 100%;_x000D_
  position: absolute;_x000D_
  top: 0;_x000D_
  bottom: 0;_x000D_
  left: 0;_x000D_
  right: 0;_x000D_
}
_x000D_
<p>This image is originally 640x220, but should get resized by the CSS:</p>_x000D_
<div class="parent">_x000D_
  <div class="container">_x000D_
    <img width="640" height="220" src="https://placehold.it/640x220">_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

For the line specifying padding, you need to calculate the aspect ratio of the image, for example:

640px (w) = 100%
220px (h) = ?

640/220 = 2.909
100/2.909 = 34.37%

So, top padding = 34.37%.

Why is it bad style to `rescue Exception => e` in Ruby?

This blog post explains it perfectly: Ruby's Exception vs StandardError: What's the difference?

Why you shouldn't rescue Exception

The problem with rescuing Exception is that it actually rescues every exception that inherits from Exception. Which is....all of them!

That's a problem because there are some exceptions that are used internally by Ruby. They don't have anything to do with your app, and swallowing them will cause bad things to happen.

Here are a few of the big ones:

  • SignalException::Interrupt - If you rescue this, you can't exit your app by hitting control-c.

  • ScriptError::SyntaxError - Swallowing syntax errors means that things like puts("Forgot something) will fail silently.

  • NoMemoryError - Wanna know what happens when your program keeps running after it uses up all the RAM? Me neither.

begin
  do_something()
rescue Exception => e
  # Don't do this. This will swallow every single exception. Nothing gets past it. 
end

I'm guessing that you don't really want to swallow any of these system-level exceptions. You only want to catch all of your application level errors. The exceptions caused YOUR code.

Luckily, there's an easy way to to this.

Rescue StandardError Instead

All of the exceptions that you should care about inherit from StandardError. These are our old friends:

NoMethodError - raised when you try to invoke a method that doesn't exist

TypeError - caused by things like 1 + ""

RuntimeError - who could forget good old RuntimeError?

To rescue errors like these, you'll want to rescue StandardError. You COULD do it by writing something like this:

begin
  do_something()
rescue StandardError => e
  # Only your app's exceptions are swallowed. Things like SyntaxErrror are left alone. 
end

But Ruby has made it much easier for use.

When you don't specify an exception class at all, ruby assumes you mean StandardError. So the code below is identical to the above code:

begin
  do_something()
rescue => e
  # This is the same as rescuing StandardError
end

Is there a simple way that I can sort characters in a string in alphabetical order

You can use this

string x = "ABCGH"

char[] charX = x.ToCharArray();

Array.Sort(charX);

This will sort your string.

Printing to the console in Google Apps Script?

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

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

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

enter image description here

Compare with viewing Logs:

enter image description here

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

Two inline-block, width 50% elements wrap to second line

It is because display:inline-block takes into account white-space in the html. If you remove the white-space between the div's it works as expected. Live Example: http://jsfiddle.net/XCDsu/4/

<div id="col1">content</div><div id="col2">content</div>

Access Google's Traffic Data through a Web Service

It is possible to get traffic data. Below is my implementation in python. The API has some quota & is not fully free, but good enough for small projects

import requests
import time
import json


while True:

    url = "https://maps.googleapis.com/maps/api/distancematrix/json"

    querystring = {"units":"metric","departure_time":str(int(time.time())),"traffic_model":"best_guess","origins":"ITPL,Bangalore","destinations":"Tin Factory,Bangalore","key":"GetYourKeyHere"}

    headers = {
        'cache-control': "no-cache",
        'postman-token': "something"
        }

    response = requests.request("GET", url, headers=headers, params=querystring)
    d = json.loads(response.text)
    print("On", time.strftime("%I:%M:%S"),"time duration is",d['rows'][0]['elements'][0]['duration']['text'], " & traffic time is ",d['rows'][0]['elements'][0]['duration_in_traffic']['text'])
    time.sleep(1800)
    print(response.text)

Response is :-

{
    "destination_addresses": [
        "Tin Factory, Swamy Vivekananda Rd, Krishna Reddy Industrial Estate, Dooravani Nagar, Bengaluru, Karnataka 560016, India"
    ],
    "origin_addresses": [
        "Whitefield Main Rd, Pattandur Agrahara, Whitefield, Bengaluru, Karnataka 560066, India"
    ],
    "rows": [
        {
            "elements": [
                {
                    "distance": {
                        "text": "10.5 km",
                        "value": 10505
                    },
                    "duration": {
                        "text": "35 mins",
                        "value": 2120
                    },
                    "duration_in_traffic": {
                        "text": "45 mins",
                        "value": 2713
                    },
                    "status": "OK"
                }
            ]
        }
    ],
    "status": "OK"
}

You need to pass "departure_time":str(int(time.time())) is a required query string parameter for traffic information.

Your traffic information would be present in duration_in_traffic.

Refer this documentation for more info.

https://developers.google.com/maps/documentation/distance-matrix/intro#traffic-model

How to convert an IPv4 address into a integer in C#?

If you were interested in the function not just the answer here is how it is done:

int ipToInt(int first, int second, 
    int third, int fourth)
{
    return Convert.ToInt32((first * Math.Pow(256, 3))
        + (second * Math.Pow(256, 2)) + (third * 256) + fourth);
}

with first through fourth being the segments of the IPv4 address.

RabbitMQ / AMQP: single queue, multiple consumers for same message?

Yes each consumer can receive the same messages. have a look at http://www.rabbitmq.com/tutorials/tutorial-three-python.html http://www.rabbitmq.com/tutorials/tutorial-four-python.html http://www.rabbitmq.com/tutorials/tutorial-five-python.html

for different ways to route messages. I know they are for python and java but its good to understand the principles, decide what you are doing and then find how to do it in JS. Its sounds like you want to do a simple fanout (tutorial 3), which sends the messages to all queues connected to the exchange.

The difference with what you are doing and what you want to do is basically that you are going to set up and exchange or type fanout. Fanout excahnges send all messages to all connected queues. Each queue will have a consumer that will have access to all the messages separately.

Yes this is commonly done, it is one of the features of AMPQ.

How to change css property using javascript

var hello = $('.right') // or var hello = document.getElementByClassName('right')
var bye = $('.right1')
hello.onmouseover = function()
{
    bye.style.visibility = 'visible'
}
hello.onmouseout = function()
{
    bye.style.visibility = 'hidden'
}

how to create a Java Date object of midnight today and midnight tomorrow?

Date todayMidnightUTC = java.sql.Date.valueOf(LocalDate.now());
Date tomorrowMidnightUTC = java.sql.Date.valueOf(LocalDate.now().plusDays(1));
Date anyMidnightLocal = java.sql.Date.valueOf(LocalDate.from(dateTime.toInstant().atZone(ZoneId.systemDefault())));

But beware that java.sql.Date.toInstant() always throws UnsupportedOperationException.

Via LocalDate to java.util.Date and vice versa simpliest conversion?

How to implement Rate It feature in Android App

Kotlin version of Raghav Sood's answer

Rater.kt

    class Rater {
      companion object {
        private const val APP_TITLE = "App Name"
        private const val APP_NAME = "com.example.name"

        private const val RATER_KEY = "rater_key"
        private const val LAUNCH_COUNTER_KEY = "launch_counter_key"
        private const val DO_NOT_SHOW_AGAIN_KEY = "do_not_show_again_key"
        private const val FIRST_LAUNCH_KEY = "first_launch_key"

        private const val DAYS_UNTIL_PROMPT: Int = 3
        private const val LAUNCHES_UNTIL_PROMPT: Int = 3

        fun start(mContext: Context) {
            val prefs: SharedPreferences = mContext.getSharedPreferences(RATER_KEY, 0)
            if (prefs.getBoolean(DO_NOT_SHOW_AGAIN_KEY, false)) {
                return
            }

            val editor: Editor = prefs.edit()

            val launchesCounter: Long = prefs.getLong(LAUNCH_COUNTER_KEY, 0) + 1;
            editor.putLong(LAUNCH_COUNTER_KEY, launchesCounter)

            var firstLaunch: Long = prefs.getLong(FIRST_LAUNCH_KEY, 0)
            if (firstLaunch == 0L) {
                firstLaunch = System.currentTimeMillis()
                editor.putLong(FIRST_LAUNCH_KEY, firstLaunch)
            }

            if (launchesCounter >= LAUNCHES_UNTIL_PROMPT) {
                if (System.currentTimeMillis() >= firstLaunch +
                    (DAYS_UNTIL_PROMPT * 24 * 60 * 60 * 1000)
                ) {
                    showRateDialog(mContext, editor)
                }
            }

            editor.apply()
        }

        fun showRateDialog(mContext: Context, editor: Editor) {
            Dialog(mContext).apply {
                setTitle("Rate $APP_TITLE")

                val ll = LinearLayout(mContext)
                ll.orientation = LinearLayout.VERTICAL

                TextView(mContext).apply {
                    text =
                        "If you enjoy using $APP_TITLE, please take a moment to rate it. Thanks for your support!"

                    width = 240
                    setPadding(4, 0, 4, 10)
                    ll.addView(this)
                }

                Button(mContext).apply {
                    text = "Rate $APP_TITLE"
                    setOnClickListener {
                        mContext.startActivity(
                            Intent(
                                Intent.ACTION_VIEW,
                                Uri.parse("market://details?id=$APP_NAME")
                            )
                        );
                        dismiss()
                    }
                    ll.addView(this)
                }

                Button(mContext).apply {
                    text = "Remind me later"
                    setOnClickListener {
                        dismiss()
                    };
                    ll.addView(this)
                }

                Button(mContext).apply {
                    text = "No, thanks"
                    setOnClickListener {
                        editor.putBoolean(DO_NOT_SHOW_AGAIN_KEY, true);
                        editor.commit()
                        dismiss()
                    };
                    ll.addView(this)
                }

                setContentView(ll)
                show()
            }
        }
    }
}

Optimized answer

Rater.kt

class Rater {
    companion object {
        fun start(context: Context) {
            val prefs: SharedPreferences = context.getSharedPreferences(RATER_KEY, 0)
            if (prefs.getBoolean(DO_NOT_SHOW_AGAIN_KEY, false)) {
                return
            }

            val editor: Editor = prefs.edit()

            val launchesCounter: Long = prefs.getLong(LAUNCH_COUNTER_KEY, 0) + 1;
            editor.putLong(LAUNCH_COUNTER_KEY, launchesCounter)

            var firstLaunch: Long = prefs.getLong(FIRST_LAUNCH_KEY, 0)
            if (firstLaunch == 0L) {
                firstLaunch = System.currentTimeMillis()
                editor.putLong(FIRST_LAUNCH_KEY, firstLaunch)
            }

            if (launchesCounter >= LAUNCHES_UNTIL_PROMPT) {
                if (System.currentTimeMillis() >= firstLaunch +
                    (DAYS_UNTIL_PROMPT * 24 * 60 * 60 * 1000)
                ) {
                    showRateDialog(context, editor)
                }
            }

            editor.apply()
        }

        fun showRateDialog(context: Context, editor: Editor) {
            Dialog(context).apply {
                setTitle("Rate $APP_TITLE")
                LinearLayout(context).let { layout ->
                    layout.orientation = LinearLayout.VERTICAL
                    setDescription(context, layout)
                    setPositiveAnswer(context, layout)
                    setNeutralAnswer(context, layout)
                    setNegativeAnswer(context, editor, layout)
                    setContentView(layout)
                    show()       
                }
            }
        }

        private fun setDescription(context: Context, layout: LinearLayout) {
            TextView(context).apply {
                text = context.getString(R.string.rate_description, APP_TITLE)
                width = 240
                setPadding(4, 0, 4, 10)
                layout.addView(this)
            }
        }

        private fun Dialog.setPositiveAnswer(
            context: Context,
            layout: LinearLayout
        ) {
            Button(context).apply {
                text = context.getString(R.string.rate_now)
                setOnClickListener {
                    context.startActivity(
                        Intent(
                            Intent.ACTION_VIEW,
                            Uri.parse(context.getString(R.string.market_uri, APP_NAME))
                        )
                    );
                    dismiss()
                }
                layout.addView(this)
            }
        }

        private fun Dialog.setNeutralAnswer(
            context: Context,
            layout: LinearLayout
        ) {
            Button(context).apply {
                text = context.getString(R.string.remind_later)
                setOnClickListener {
                    dismiss()
                };
                layout.addView(this)
            }
        }

        private fun Dialog.setNegativeAnswer(
            context: Context,
            editor: Editor,
            layout: LinearLayout
        ) {
            Button(context).apply {
                text = context.getString(R.string.no_thanks)
                setOnClickListener {
                    editor.putBoolean(DO_NOT_SHOW_AGAIN_KEY, true);
                    editor.commit()
                    dismiss()
                };
                layout.addView(this)
            }
        }
    }
}

Constants.kt

object Constants {

    const val APP_TITLE = "App Name"
    const val APP_NAME = "com.example.name"

    const val RATER_KEY = "rater_key"
    const val LAUNCH_COUNTER_KEY = "launch_counter_key"
    const val DO_NOT_SHOW_AGAIN_KEY = "do_not_show_again_key"
    const val FIRST_LAUNCH_KEY = "first_launch_key"

    const val DAYS_UNTIL_PROMPT: Int = 3
    const val LAUNCHES_UNTIL_PROMPT: Int = 3

}

strings.xml

<resources>
    <string name="rate_description">If you enjoy using %1$s, please take a moment to rate it. Thanks for your support!</string>
    <string name="rate_now">Rate now</string>
    <string name="no_thanks">No, thanks</string>
    <string name="remind_later">Remind me later</string>
    <string name="market_uri">market://details?id=%1$s</string>
</resources>

How to move the cursor word by word in the OS X Terminal

As of Mac OS X Lion 10.7, Terminal maps Option-Left/Right Arrow to Esc-b/f by default, so this is now built-in for bash and other programs that use these emacs-compatible keybindings.

What is the "continue" keyword and how does it work in Java?

If you think of the body of a loop as a subroutine, continue is sort of like return. The same keyword exists in C, and serves the same purpose. Here's a contrived example:

for(int i=0; i < 10; ++i) {
  if (i % 2 == 0) {
    continue;
  }
  System.out.println(i);
}

This will print out only the odd numbers.

How to destroy an object?

I would go with unset because it might give the garbage collector a better hint so that the memory can be available again sooner. Be careful that any things the object points to either have other references or get unset first or you really will have to wait on the garbage collector since there would then be no handles to them.

submit the form using ajax

I would suggest to use jquery for this type of requirement . Give this a try

<div id="commentList"></div>
<div id="addCommentContainer">
    <p>Add a Comment</p> <br/> <br/>
    <form id="addCommentForm" method="post" action="">
        <div>
            Your Name <br/>
            <input type="text" name="name" id="name" />


            <br/> <br/>
            Comment Body <br/>
            <textarea name="body" id="body" cols="20" rows="5"></textarea>

            <input type="submit" id="submit" value="Submit" />
        </div>
    </form>
</div>?

$(document).ready(function(){
    /* The following code is executed once the DOM is loaded */

    /* This flag will prevent multiple comment submits: */
    var working = false;
    $("#submit").click(function(){
    $.ajax({
         type: 'POST',
         url: "mysubmitpage.php",
         data: $('#addCommentForm').serialize(), 
         success: function(response) {
            alert("Submitted comment"); 
             $("#commentList").append("Name:" + $("#name").val() + "<br/>comment:" + $("#body").val());
         },
        error: function() {
             //$("#commentList").append($("#name").val() + "<br/>" + $("#body").val());
            alert("There was an error submitting comment");
        }
     });
});
});?

What does the "~" (tilde/squiggle/twiddle) CSS selector mean?

Note that in an attribute selector (e.g., [attr~=value]), the tilde

Represents an element with an attribute name of attr whose value is a whitespace-separated list of words, one of which is exactly value.

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

How can I change image tintColor in iOS and WatchKit

Take benefit of Extension in Swift :-

extension UIImageView {
    func changeImageColor( color:UIColor) -> UIImage
    {
        image = image!.withRenderingMode(.alwaysTemplate)
        tintColor = color
        return image!
    }
}

   //Change color of logo 
   logoImage.image =  logoImage.changeImageColor(color: .red)

enter image description here

Check whether there is an Internet connection available on Flutter app

I found that just using the connectivity package was not enough to tell if the internet was available or not. In Android it only checks if there is WIFI or if mobile data is turned on, it does not check for an actual internet connection . During my testing, even with no mobile signal ConnectivityResult.mobile would return true.

With IOS my testing found that the connectivity plugin does correctly detect if there is an internet connection when the phone has no signal, the issue was only with Android.

The solution I found was to use the data_connection_checker package along with the connectivity package. This just makes sure there is an internet connection by making requests to a few reliable addresses, the default timeout for the check is around 10 seconds.

My finished isInternet function looked a bit like this:

  Future<bool> isInternet() async {
    var connectivityResult = await (Connectivity().checkConnectivity());
    if (connectivityResult == ConnectivityResult.mobile) {
      // I am connected to a mobile network, make sure there is actually a net connection.
      if (await DataConnectionChecker().hasConnection) {
        // Mobile data detected & internet connection confirmed.
        return true;
      } else {
        // Mobile data detected but no internet connection found.
        return false;
      }
    } else if (connectivityResult == ConnectivityResult.wifi) {
      // I am connected to a WIFI network, make sure there is actually a net connection.
      if (await DataConnectionChecker().hasConnection) {
        // Wifi detected & internet connection confirmed.
        return true;
      } else {
        // Wifi detected but no internet connection found.
        return false;
      }
    } else {
      // Neither mobile data or WIFI detected, not internet connection found.
      return false;
    }
  }

The if (await DataConnectionChecker().hasConnection) part is the same for both mobile and wifi connections and should probably be moved to a separate function. I've not done that here to leave it more readable.

This is my first Stack Overflow answer, hope it helps someone.

How to run Tensorflow on CPU

You can also set the environment variable to

CUDA_VISIBLE_DEVICES=""

without having to modify the source code.

Python nonlocal statement

In short, it lets you assign values to a variable in an outer (but non-global) scope. See PEP 3104 for all the gory details.

How to return first 5 objects of Array in Swift?

Swift 4 with saving array types

extension Array {
    func take(_ elementsCount: Int) -> [Element] {
        let min = Swift.min(elementsCount, count)
        return Array(self[0..<min])
    }
}

Convert from ASCII string encoded in Hex to plain ASCII?

No need to import any library:

>>> bytearray.fromhex("7061756c").decode()
'paul'

Disable PHP in directory (including all sub-directories) with .htaccess

<Directory /your/directorypath/>
     php_admin_value engine Off
</Directory>

How to add an image in the title bar using html?

Try the following:

<link rel="icon" type="image/png" href="img/iconimg.png" />

NB: The href is the directory to your image example. Your image is in a folder called "img" and your image name is "iconimg" and if it is a png use .png, if it is a jpg then .jpg. Remember to do this in the head of your file and not in the body.

How to create unit tests easily in eclipse

You can use my plug-in to create tests easily:

  1. highlight the method
  2. press Ctrl+Alt+Shift+U
  3. it will create the unit test for it.

The plug-in is available here. Hope this helps.

NUnit Unit tests not showing in Test Explorer with Test Adapter installed

I started a new solution with a test project in it, and compared it against my original, problem project. The original, for some reason, had an app.config in it. I excluded that file from the project and saw my tests reappear in the test explorer.

List method to delete last element in list as well as all elements

you can use lst.pop() or del lst[-1]

pop() removes and returns the item, in case you don't want have a return use del

How to import local packages without gopath

There's no such thing as "local package". The organization of packages on a disk is orthogonal to any parent/child relations of packages. The only real hierarchy formed by packages is the dependency tree, which in the general case does not reflect the directory tree.

Just use

import "myproject/packageN"

and don't fight the build system for no good reason. Saving a dozen of characters per import in any non trivial program is not a good reason, because, for example, projects with relative import paths are not go-gettable.

The concept of import paths have some important properties:

  • Import paths can be be globally unique.
  • In conjunction with GOPATH, import path can be translated unambiguously to a directory path.
  • Any directory path under GOPATH can be unambiguously translated to an import path.

All of the above is ruined by using relative import paths. Do not do it.

PS: There are few places in the legacy code in Go compiler tests which use relative imports. ATM, this is the only reason why relative imports are supported at all.

Cross field validation with Hibernate Validator (JSR 303)

I have tried Alberthoven's example (hibernate-validator 4.0.2.GA) and i get an ValidationException: „Annotated methods must follow the JavaBeans naming convention. match() does not.“ too. After I renamed the method from „match“ to "isValid" it works.

public class Password {

    private String password;

    private String retypedPassword;

    public Password(String password, String retypedPassword) {
        super();
        this.password = password;
        this.retypedPassword = retypedPassword;
    }

    @AssertTrue(message="password should match retyped password")
    private boolean isValid(){
        if (password == null) {
            return retypedPassword == null;
        } else {
            return password.equals(retypedPassword);
        }
    }

    public String getPassword() {
        return password;
    }

    public String getRetypedPassword() {
        return retypedPassword;
    }

}

javascript set cookie with expire time

I'd like to second Polin's answer and just add one thing in case you are still stuck. This code certainly does work to set a specific cookie expiration time. One issue you may be having is that if you are using Chrome and accessing your page via "http://localhost..." or "file://", Chrome will not store cookies. The easy fix for this is to use a simple http server (like node's http-server if you haven't already) and navigate to your page explicitly as "http://127.0.0.1" in which case Chrome WILL store cookies for local development. This had me hung up for a bit as, if you don't do this, your expires key will simply have the value of "session" when you investigate it in the console or in Dev Tools.

What is a "bundle" in an Android application

First activity:

String food = (String)((Spinner)findViewById(R.id.food)).getSelectedItem();
RadioButton rb = (RadioButton) findViewById(R.id.rb);
Intent i = new Intent(this,secondActivity.class);
i.putExtra("food",food);
i.putExtra("rb",rb.isChecked());

Second activity:

String food = getIntent().getExtras().getString("food");
Boolean rb = getIntent().getExtras().getBoolean("rb");

What does operator "dot" (.) mean?

There is a whole page in the MATLAB documentation dedicated to this topic: Array vs. Matrix Operations. The gist of it is below:

MATLAB® has two different types of arithmetic operations: array operations and matrix operations. You can use these arithmetic operations to perform numeric computations, for example, adding two numbers, raising the elements of an array to a given power, or multiplying two matrices.

Matrix operations follow the rules of linear algebra. By contrast, array operations execute element by element operations and support multidimensional arrays. The period character (.) distinguishes the array operations from the matrix operations. However, since the matrix and array operations are the same for addition and subtraction, the character pairs .+ and .- are unnecessary.

Group By Multiple Columns

Procedural sample

.GroupBy(x => new { x.Column1, x.Column2 })

set environment variable in python script

There are many good answers here but you should avoid at all cost to pass untrusted variables to subprocess using shell=True as this is a security risk. The variables can escape to the shell and run arbitrary commands! If you just can't avoid it at least use python3's shlex.quote() to escape the string (if you have multiple space-separated arguments, quote each split instead of the full string).

shell=False is always the default where you pass an argument array.

Now the safe solutions...

Method #1

Change your own process's environment - the new environment will apply to python itself and all subprocesses.

os.environ['LD_LIBRARY_PATH'] = 'my_path'
command = ['sqsub', '-np', var1, '/homedir/anotherdir/executable']
subprocess.check_call(command)

Method #2

Make a copy of the environment and pass is to the childen. You have total control over the children environment and won't affect python's own environment.

myenv = os.environ.copy()
myenv['LD_LIBRARY_PATH'] = 'my_path'
command = ['sqsub', '-np', var1, '/homedir/anotherdir/executable']
subprocess.check_call(command, env=myenv)

Method #3

Unix only: Execute env to set the environment variable. More cumbersome if you have many variables to modify and not portabe, but like #2 you retain full control over python and children environments.

command = ['env', 'LD_LIBRARY_PATH=my_path', 'sqsub', '-np', var1, '/homedir/anotherdir/executable']
subprocess.check_call(command)

Of course if var1 contain multiple space-separated argument they will now be passed as a single argument with spaces. To retain original behavior with shell=True you must compose a command array that contain the splitted string:

command = ['sqsub', '-np'] + var1.split() + ['/homedir/anotherdir/executable']

How to copy from CSV file to PostgreSQL table with headers in CSV file?

With the Python library pandas, you can easily create column names and infer data types from a csv file.

from sqlalchemy import create_engine
import pandas as pd

engine = create_engine('postgresql://user:pass@localhost/db_name')
df = pd.read_csv('/path/to/csv_file')
df.to_sql('pandas_db', engine)

The if_exists parameter can be set to replace or append to an existing table, e.g. df.to_sql('pandas_db', engine, if_exists='replace'). This works for additional input file types as well, docs here and here.

How to make use of ng-if , ng-else in angularJS

Use ng-switch with expression and ng-switch-when for matching expression value:

<div ng-switch="data.id">
  <div ng-switch-when="5">...</div>
  <div ng-switch-default>...</div>
</div>

Example is here

Angular2 example

Display a angular variable in my html page

In your template, you have access to all the variables that are members of the current $scope. So, tobedone should be $scope.tobedone, and then you can display it with {{tobedone}}, or [[tobedone]] in your case.

How can I output a UTF-8 CSV in PHP that Excel will read properly?

In my case following works very nice to make CSV file with UTF-8 chars displayed correctly in Excel.

$out = fopen('php://output', 'w');
fprintf($out, chr(0xEF).chr(0xBB).chr(0xBF));
fputcsv($out, $some_csv_strings);

The 0xEF 0xBB 0xBF BOM header will let Excel know the correct encoding.

java.sql.SQLException: Missing IN or OUT parameter at index:: 1

This is not how SQL works:

INSERT INTO employee(hans,germany) values(?,?)

The values (hans,germany) should use column names (emp_name, emp_address). The values are provided by your program by using the Statement.setString(pos,value) methods. It is complaining because you said there were two parameters (the question marks) but didn't provide values.

You should be creating a PreparedStatement and then setting parameter values as in:

String insert= "INSERT INTO employee(emp_name,emp_address) values(?,?)";
PreparedStatement stmt = con.prepareStatement(insert);
stmt.setString(1,"hans");
stmt.setString(2,"germany");
stmt.execute();

Is there any way of configuring Eclipse IDE proxy settings via an autoproxy configuration script?

In Netbeans, we can use Tools->Options-> General Tab - > Under proxy settings, select Use system proxy settings.

This way, it uses the proxy settings provided in Settings -> Control Panel -> Internet Options -> Connections -> Lan Settings -> use automatic configuration scripts.

If you are using maven, make sure the proxy settings are not provided there, so that it uses Netbeans settings provided above for proxy.

Hope this helps.

Shreedevi

DropdownList DataSource

Refer to example at this link. It may be help to you.

http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.dropdownlist.aspx

void Page_Load(Object sender, EventArgs e)
  {

     // Load data for the DropDownList control only once, when the 
     // page is first loaded.
     if(!IsPostBack)
     {

        // Specify the data source and field names for the Text 
        // and Value properties of the items (ListItem objects) 
        // in the DropDownList control.
        ColorList.DataSource = CreateDataSource();
        ColorList.DataTextField = "ColorTextField";
        ColorList.DataValueField = "ColorValueField";

        // Bind the data to the control.
        ColorList.DataBind();

        // Set the default selected item, if desired.
        ColorList.SelectedIndex = 0;

     }

  }

void Selection_Change(Object sender, EventArgs e)
  {

     // Set the background color for days in the Calendar control
     // based on the value selected by the user from the 
     // DropDownList control.
     Calendar1.DayStyle.BackColor = 
         System.Drawing.Color.FromName(ColorList.SelectedItem.Value);

  }

Sending emails with Javascript

You can add the following to the <head> of your HTML file:

<script src="https://smtpjs.com/v3/smtp.js"></script>

<script type="text/javascript">
    function sendEmail() {
        Email.send({
            SecureToken: "security token of your smtp",
            To: "[email protected]",
            From: "[email protected]",
            Subject: "Subject...",
            Body: document.getElementById('text').value
        }).then( 
            message => alert("mail sent successfully")
        );
    }
</script>

and below is the HMTL part:

<textarea id="text">write text here...</textarea>
<input type="button" value="Send Email" onclick="sendEmail()">

So the sendEmail() function gets the inputs using:

document.getElementById('id_of_the_element').value

For example, you can add another HTML element such as the subject (with id="subject"):

<textarea id="subject">write text here...</textarea>

and get its value in the sendEmail() function:

Subject: document.getElementById('subject').value

And you are done!

Note: If you do not have a SMTP server you can create one for free here. And then encrypt your SMTP credentials here (the SecureToken attribute in sendEmail() corresponds to the encrypted credentials generated there).

Ignoring NaNs with str.contains

import folium
import pandas

data= pandas.read_csv("maps.txt")

lat = list(data["latitude"])
lon = list(data["longitude"])

map= folium.Map(location=[31.5204, 74.3587], zoom_start=6, tiles="Mapbox Bright")

fg = folium.FeatureGroup(name="My Map")

for lt, ln in zip(lat, lon):
c1 = fg.add_child(folium.Marker(location=[lt, ln], popup="Hi i am a Country",icon=folium.Icon(color='green')))

child = fg.add_child(folium.Marker(location=[31.5204, 74.5387], popup="Welcome to Lahore", icon= folium.Icon(color='green')))

map.add_child(fg)

map.save("Lahore.html")


Traceback (most recent call last):
  File "C:\Users\Ryan\AppData\Local\Programs\Python\Python36-32\check2.py", line 14, in <module>
    c1 = fg.add_child(folium.Marker(location=[lt, ln], popup="Hi i am a Country",icon=folium.Icon(color='green')))
  File "C:\Users\Ryan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\folium\map.py", line 647, in __init__
    self.location = _validate_coordinates(location)
  File "C:\Users\Ryan\AppData\Local\Programs\Python\Python36-32\lib\site-packages\folium\utilities.py", line 48, in _validate_coordinates
    'got:\n{!r}'.format(coordinates))
ValueError: Location values cannot contain NaNs, got:
[nan, nan]

NameError: global name 'unicode' is not defined - in Python 3

You can use the six library to support both Python 2 and 3:

import six
if isinstance(value, six.string_types):
    handle_string(value)

Why do I get "Cannot redirect after HTTP headers have been sent" when I call Response.Redirect()?

I solved the problem using: Response.RedirectToRoute("CultureEnabled", RouteData.Values); instead of Response.Redirect.

How to create a DataFrame from a text file in Spark

You will not able to convert it into data frame until you use implicit conversion.

val sqlContext = new SqlContext(new SparkContext())

import sqlContext.implicits._

After this only you can convert this to data frame

case class Test(id:String,filed2:String)

val myFile = sc.textFile("file.txt")

val df= myFile.map( x => x.split(";") ).map( x=> Test(x(0),x(1)) ).toDF()

C pointers and arrays: [Warning] assignment makes pointer from integer without a cast

In this case a[4] is the 5th integer in the array a, ap is a pointer to integer, so you are assigning an integer to a pointer and that's the warning.
So ap now holds 45 and when you try to de-reference it (by doing *ap) you are trying to access a memory at address 45, which is an invalid address, so your program crashes.

You should do ap = &(a[4]); or ap = a + 4;

In c array names decays to pointer, so a points to the 1st element of the array.
In this way, a is equivalent to &(a[0]).

insert a NOT NULL column to an existing table

Alter TABLE 'TARGET' add 'ShouldAddColumn' Integer Not Null default "0"

SELECT with a Replace()

This will work:

SELECT Replace(Postcode, ' ', '') AS P
FROM Contacts
WHERE Replace(Postcode, ' ', '') LIKE 'NW101%'

How to convert string to integer in UNIX

Use this:

#include <stdlib.h>
#include <string.h>

int main()
{
    const char *d1 = "11";
    int d1int = atoi(d1);
    printf("d1 = %d\n", d1);
    return 0;
}

etc.

ReactJS map through Object

I use the below Object.entries to easily output the key and the value:

{Object.entries(someObject).map(([key, val], i) => (
    <p key={i}>
        {key}: {val}
    </p>
))}

Convert dictionary to list collection in C#

To convert the Keys to a List of their own:

listNumber = dicNumber.Select(kvp => kvp.Key).ToList();

Or you can shorten it up and not even bother using select:

listNumber = dicNumber.Keys.ToList();

Reading a single char in Java

Here is a class 'getJ' with a static function 'chr()'. This function reads one char.

import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.IOException;

class getJ {
    static char  chr()throws IOException{  
        BufferedReader bufferReader =new BufferedReader(new InputStreamReader(System.in));
        return bufferReader.readLine().charAt(0);
    }
}

In order to read a char use this:

anyFunc()throws IOException{
...
...
char c=getJ.chr();
}

Because of 'chr()' is static, you don't have to create 'getJ' by 'new' ; I mean you don't need to do:

getJ ob = new getJ;
c=ob.chr();

You should remember to add 'throws IOException' to the function's head. If it's impossible, use try / catch as follows:

anyFunc(){// if it's impossible to add 'throws IOException' here
...
try
{
char c=getJ.chr(); //reads a char into c
} 
catch(IOException e)
{
System.out.println("IOException has been caught");
}

Credit to: tutorialspoint.com

See also: geeksforgeeks.

How to change the background color on a Java panel?

I am assuming that we are dealing with a JFrame? The visible portion in the content pane - you have to use jframe.getContentPane().setBackground(...);

Replacing column values in a pandas DataFrame

w.replace({'female':{'female':1, 'male':0}}, inplace = True)

The above code will replace 'female' with 1 and 'male' with 0, only in the column 'female'

ERROR Source option 1.5 is no longer supported. Use 1.6 or later

For me the solution was to set the version of the maven compiler plugin to 3.8.0 and specify the release (9 for in your case, 11 in mine)

    <plugin>
      <artifactId>maven-compiler-plugin</artifactId>
      <version>3.8.0</version>
      <configuration>
        <release>11</release>
      </configuration>
    </plugin>

Browser/HTML Force download of image from src="data:image/jpeg;base64..."

Simply replace image/jpeg with application/octet-stream. The client would not recognise the URL as an inline-able resource, and prompt a download dialog.

A simple JavaScript solution would be:

//var img = reference to image
var url = img.src.replace(/^data:image\/[^;]+/, 'data:application/octet-stream');
window.open(url);
// Or perhaps: location.href = url;
// Or even setting the location of an <iframe> element, 

Another method is to use a blob: URI:

var img = document.images[0];
img.onclick = function() {
    // atob to base64_decode the data-URI
    var image_data = atob(img.src.split(',')[1]);
    // Use typed arrays to convert the binary data to a Blob
    var arraybuffer = new ArrayBuffer(image_data.length);
    var view = new Uint8Array(arraybuffer);
    for (var i=0; i<image_data.length; i++) {
        view[i] = image_data.charCodeAt(i) & 0xff;
    }
    try {
        // This is the recommended method:
        var blob = new Blob([arraybuffer], {type: 'application/octet-stream'});
    } catch (e) {
        // The BlobBuilder API has been deprecated in favour of Blob, but older
        // browsers don't know about the Blob constructor
        // IE10 also supports BlobBuilder, but since the `Blob` constructor
        //  also works, there's no need to add `MSBlobBuilder`.
        var bb = new (window.WebKitBlobBuilder || window.MozBlobBuilder);
        bb.append(arraybuffer);
        var blob = bb.getBlob('application/octet-stream'); // <-- Here's the Blob
    }

    // Use the URL object to create a temporary URL
    var url = (window.webkitURL || window.URL).createObjectURL(blob);
    location.href = url; // <-- Download!
};

Relevant documentation

Regular expression to match DNS hostname or IP Address?

how about this?

([0-9]{1,3}\.){3}[0-9]{1,3}

Jenkins pipeline if else not working

It requires a bit of rearranging, but when does a good job to replace conditionals above. Here's the example from above written using the declarative syntax. Note that test3 stage is now two different stages. One that runs on the master branch and one that runs on anything else.

stage ('Test 3: Master') {
    when { branch 'master' }
    steps { 
        echo 'I only execute on the master branch.' 
    }
}

stage ('Test 3: Dev') {
    when { not { branch 'master' } }
    steps {
        echo 'I execute on non-master branches.'
    }
}

How to verify if a file exists in a batch file?

Type IF /? to get help about if, it clearly explains how to use IF EXIST.

To delete a complete tree except some folders, see the answer of this question: Windows batch script to delete everything in a folder except one

Finally copying just means calling COPY and calling another bat file can be done like this:

MYOTHERBATFILE.BAT sync.bat myprogram.ini

How to do multiple conditions for single If statement

Use the 'And' keyword for a logical and. Like this:

If Not ((filename = testFileName) And (fileName <> "")) Then

<input type="file"> limit selectable files by extensions

NOTE: This answer is from 2011. It was a really good answer back then, but as of 2015, native HTML properties are supported by most browsers, so there's (usually) no need to implement such custom logic in JS. See Edi's answer and the docs.


Before the file is uploaded, you can check the file's extension using Javascript, and prevent the form being submitted if it doesn't match. The name of the file to be uploaded is stored in the "value" field of the form element.

Here's a simple example that only allows files that end in ".gif" to be uploaded:

<script type="text/javascript">
    function checkFile() {
        var fileElement = document.getElementById("uploadFile");
        var fileExtension = "";
        if (fileElement.value.lastIndexOf(".") > 0) {
            fileExtension = fileElement.value.substring(fileElement.value.lastIndexOf(".") + 1, fileElement.value.length);
        }
        if (fileExtension.toLowerCase() == "gif") {
            return true;
        }
        else {
            alert("You must select a GIF file for upload");
            return false;
        }
    }
</script>

<form action="upload.aspx" enctype="multipart/form-data" onsubmit="return checkFile();">
    <input name="uploadFile" id="uploadFile" type="file" />

    <input type="submit" />
</form>

However, this method is not foolproof. Sean Haddy is correct that you always want to check on the server side, because users can defeat your Javascript checking by turning off javascript, or editing your code after it arrives in their browser. Definitely check server-side in addition to the client-side check. Also I recommend checking for size server-side too, so that users don't crash your server with a 2 GB file (there's no way that I know of to check file size on the client side without using Flash or a Java applet or something).

However, checking client side before hand using the method I've given here is still useful, because it can prevent mistakes and is a minor deterrent to non-serious mischief.

How to pass payload via JSON file for curl?

curl sends POST requests with the default content type of application/x-www-form-urlencoded. If you want to send a JSON request, you will have to specify the correct content type header:

$ curl -vX POST http://server/api/v1/places.json -d @testplace.json \
--header "Content-Type: application/json"

But that will only work if the server accepts json input. The .json at the end of the url may only indicate that the output is json, it doesn't necessarily mean that it also will handle json input. The API documentation should give you a hint on whether it does or not.

The reason you get a 401 and not some other error is probably because the server can't extract the auth_token from your request.

"A referral was returned from the server" exception when accessing AD from C#

I know this might sound silly, but I recently came across this myself, Make sure the domain controller is not read-only.

Resetting a multi-stage form with jQuery

I was having the same problem and the post of Paolo helped me out, but I needed to adjust one thing. My form with id advancedindexsearch only contained input fields and gets the values from a session. For some reason the following did not work for me:

$("#advancedindexsearch").find("input:text").val("");

If I put an alert after this, I saw the values where removed correctly but afterwards they where replaced again. I still don't know how or why but the following line did do the trick for me:

$("#advancedindexsearch").find("input:text").attr("value","");

Function to check if a string is a date

if (strtotime($date)>strtotime(0)) { echo 'it is a date' }

Python method for reading keypress?

from msvcrt import getch

pos = [0, 0]

def fright():
    global pos
    pos[0] += 1

def fleft():
    global pos 
    pos[0] -= 1

def fup():
    global pos
    pos[1] += 1

def fdown():
    global pos
    pos[1] -= 1

while True:
    print'Distance from zero: ', pos
    key = ord(getch())
    if key == 27: #ESC
        break
    elif key == 13: #Enter
        print('selected')
    elif key == 32: #Space
        print('jump')
    elif key == 224: #Special keys (arrows, f keys, ins, del, etc.)
        key = ord(getch())
        if key == 80: #Down arrow
            print('down')
            fdown
        elif key == 72: #Up arrow
            print('up')
            fup()
        elif key == 75: #Left arrow
            print('left')
            fleft()
        elif key == 77: #Right arrow
            print('right')
            fright()

How does Tomcat find the HOME PAGE of my Web App?

I already had index.html in the WebContent folder but it was not showing up , finally i added the following piece of code in my projects web.xml and it started showing up

  <servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping> 

How to bind WPF button to a command in ViewModelBase?

 <Grid >
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*"/>
    </Grid.ColumnDefinitions>
    <Button Command="{Binding ClickCommand}" Width="100" Height="100" Content="wefwfwef"/>
</Grid>

the code behind for the window:

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        DataContext = new ViewModelBase();
    }
}

The ViewModel:

public class ViewModelBase
{
    private ICommand _clickCommand;
    public ICommand ClickCommand
    {
        get
        {
            return _clickCommand ?? (_clickCommand = new CommandHandler(() => MyAction(), ()=> CanExecute));
        }
    }
     public bool CanExecute
     {
        get
        {
            // check if executing is allowed, i.e., validate, check if a process is running, etc. 
            return true/false;
        }
     }

    public void MyAction()
    {

    }
}

Command Handler:

 public class CommandHandler : ICommand
{
    private Action _action;
    private Func<bool> _canExecute;

    /// <summary>
    /// Creates instance of the command handler
    /// </summary>
    /// <param name="action">Action to be executed by the command</param>
    /// <param name="canExecute">A bolean property to containing current permissions to execute the command</param>
    public CommandHandler(Action action, Func<bool> canExecute)
    {
        _action = action;
        _canExecute = canExecute;
    }

    /// <summary>
    /// Wires CanExecuteChanged event 
    /// </summary>
    public event EventHandler CanExecuteChanged
    {
        add { CommandManager.RequerySuggested += value; }
        remove { CommandManager.RequerySuggested -= value; }
    }

    /// <summary>
    /// Forcess checking if execute is allowed
    /// </summary>
    /// <param name="parameter"></param>
    /// <returns></returns>
    public bool CanExecute(object parameter)
    {
        return _canExecute.Invoke();
    }

    public void Execute(object parameter)
    {
        _action();
    }
}

I hope this will give you the idea.

How can I get the timezone name in JavaScript?

This gets the timezone code (e.g., GMT) in older javascript (I'm using google app script with old engine):

function getTimezoneName() {
  return new Date().toString().get(/\((.+)\)/);
}

I'm just putting this here in case someone needs it.

Get top n records for each group of grouped results

In other databases you can do this using ROW_NUMBER. MySQL doesn't support ROW_NUMBER but you can use variables to emulate it:

SELECT
    person,
    groupname,
    age
FROM
(
    SELECT
        person,
        groupname,
        age,
        @rn := IF(@prev = groupname, @rn + 1, 1) AS rn,
        @prev := groupname
    FROM mytable
    JOIN (SELECT @prev := NULL, @rn := 0) AS vars
    ORDER BY groupname, age DESC, person
) AS T1
WHERE rn <= 2

See it working online: sqlfiddle


Edit I just noticed that bluefeet posted a very similar answer: +1 to him. However this answer has two small advantages:

  1. It it is a single query. The variables are initialized inside the SELECT statement.
  2. It handles ties as described in the question (alphabetical order by name).

So I'll leave it here in case it can help someone.

Get local href value from anchor (a) tag

document.getElementById("link").getAttribute("href"); If you have more than one <a> tag, for example:

_x000D_
_x000D_
<ul>_x000D_
  <li>_x000D_
    <a href="1"></a>_x000D_
  </li>_x000D_
  <li>_x000D_
    <a href="2"></a>_x000D_
  </li>_x000D_
  <li>_x000D_
    <a href="3"></a>_x000D_
  </li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

You can do it like this: document.getElementById("link")[0].getAttribute("href"); to access the first array of <a> tags, or depends on the condition you make.

What is the difference between const and readonly in C#?

Const and readonly are similar, but they are not exactly the same. A const field is a compile-time constant, meaning that that value can be computed at compile-time. A readonly field enables additional scenarios in which some code must be run during construction of the type. After construction, a readonly field cannot be changed.

For instance, const members can be used to define members like:

struct Test
{
    public const double Pi = 3.14;
    public const int Zero = 0;
}

since values like 3.14 and 0 are compile-time constants. However, consider the case where you define a type and want to provide some pre-fab instances of it. E.g., you might want to define a Color class and provide "constants" for common colors like Black, White, etc. It isn't possible to do this with const members, as the right hand sides are not compile-time constants. One could do this with regular static members:

public class Color
{
    public static Color Black = new Color(0, 0, 0);
    public static Color White = new Color(255, 255, 255);
    public static Color Red = new Color(255, 0, 0);
    public static Color Green = new Color(0, 255, 0);
    public static Color Blue = new Color(0, 0, 255);
    private byte red, green, blue;

    public Color(byte r, byte g, byte b) {
        red = r;
        green = g;
        blue = b;
    }
}

but then there is nothing to keep a client of Color from mucking with it, perhaps by swapping the Black and White values. Needless to say, this would cause consternation for other clients of the Color class. The "readonly" feature addresses this scenario. By simply introducing the readonly keyword in the declarations, we preserve the flexible initialization while preventing client code from mucking around.

public class Color
{
    public static readonly Color Black = new Color(0, 0, 0);
    public static readonly Color White = new Color(255, 255, 255);
    public static readonly Color Red = new Color(255, 0, 0);
    public static readonly Color Green = new Color(0, 255, 0);
    public static readonly Color Blue = new Color(0, 0, 255);
    private byte red, green, blue;

    public Color(byte r, byte g, byte b) {
        red = r;
        green = g;
        blue = b;
    }
}

It is interesting to note that const members are always static, whereas a readonly member can be either static or not, just like a regular field.

It is possible to use a single keyword for these two purposes, but this leads to either versioning problems or performance problems. Assume for a moment that we used a single keyword for this (const) and a developer wrote:

public class A
{
    public static const C = 0;
}

and a different developer wrote code that relied on A:

public class B
{
    static void Main() {
        Console.WriteLine(A.C);
    }
}

Now, can the code that is generated rely on the fact that A.C is a compile-time constant? I.e., can the use of A.C simply be replaced by the value 0? If you say "yes" to this, then that means that the developer of A cannot change the way that A.C is initialized -- this ties the hands of the developer of A without permission. If you say "no" to this question then an important optimization is missed. Perhaps the author of A is positive that A.C will always be zero. The use of both const and readonly allows the developer of A to specify the intent. This makes for better versioning behavior and also better performance.

Opening XML page shows "This XML file does not appear to have any style information associated with it."

This XML file does not appear to have any style information associated with it. The document tree is shown below.

You will get this error in the client side when the client (the webbrowser) for some reason interprets the HTTP response content as text/xml instead of text/html and the parsed XML tree doesn't have any XML-stylesheet. In other words, the webbrowser incorrectly parsed the retrieved HTTP response content as XML instead of as HTML due to the wrong or missing HTTP response content type.

In case of JSF/Facelets files which have the default extension of .xhtml, that can in turn happen if the HTTP request hasn't invoked the FacesServlet and thus it wasn't able to parse the Facelets file and generate the desired HTML output based on the XHTML source code. Firefox is then merely guessing the HTTP response content type based on the .xhtml file extension which is in your Firefox configuration apparently by default interpreted as text/xml.

You need to make sure that the HTTP request URL, as you see in browser's address bar, matches the <url-pattern> of the FacesServlet as registered in webapp's web.xml, so that it will be invoked and be able to generate the desired HTML output based on the XHTML source code. If it's for example *.jsf, then you need to open the page by /some.jsf instead of /some.xhtml. Alternatively, you can also just change the <url-pattern> to *.xhtml. This way you never need to fiddle with virtual URLs.

See also:


Note thus that you don't actually need a XML stylesheet. This all was just misinterpretation by the webbrowser while trying to do its best to make something presentable out of the retrieved HTTP response content. It should actually have retrieved the properly generated HTML output, Firefox surely knows precisely how to deal with HTML content.

How to remove the first Item from a list?

If you are working with numpy you need to use the delete method:

import numpy as np

a = np.array([1, 2, 3, 4, 5])

a = np.delete(a, 0)

print(a) # [2 3 4 5]

Count number of records returned by group by

I was trying to achieve the same without subquery and was able to get the required result as below

SELECT DISTINCT COUNT(*) OVER () AS TotalRecords
FROM temptable
GROUP BY column_1, column_2, column_3, column_4

ng-options with simple array init

<select ng-model="option" ng-options="o for o in options">

$scope.option will be equal to 'var1' after change, even you see value="0" in generated html

plunker

How many concurrent AJAX (XmlHttpRequest) requests are allowed in popular browsers?

With IE6 / IE7 one can tweak the number of concurrent requests in the registry. Here's how to set it to four each.

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"MaxConnectionsPerServer"=dword:00000004
"MaxConnectionsPer1_0Server"=dword:00000004

Finding and removing non ascii characters from an Oracle Varchar2

Do this, it will work.

trim(replace(ntwk_slctor_key_txt, chr(0), ''))

How to merge many PDF files into a single one?

You can use http://www.mergepdf.net/ for example

Or:

PDFTK http://www.pdflabs.com/tools/pdftk-the-pdf-toolkit/

If you are NOT on Ubuntu and you have the same problem (and you wanted to start a new topic on SO and SO suggested to have a look at this question) you can also do it like this:

Things You'll Need:

* Full Version of Adobe Acrobat
  1. Open all the .pdf files you wish to merge. These can be minimized on your desktop as individual tabs.

  2. Pull up what you wish to be the first page of your merged document.

  3. Click the 'Combine Files' icon on the top left portion of the screen.

  4. The 'Combine Files' window that pops up is divided into three sections. The first section is titled, 'Choose the files you wish to combine'. Select the 'Add Open Files' option.

  5. Select the other open .pdf documents on your desktop when prompted.

  6. Rearrange the documents as you wish in the second window, titled, 'Arrange the files in the order you want them to appear in the new PDF'

  7. The final window, titled, 'Choose a file size and conversion setting' allows you to control the size of your merged PDF document. Consider the purpose of your new document. If its to be sent as an e-mail attachment, use a low size setting. If the PDF contains images or is to be used for presentation, choose a high setting. When finished, select 'Next'.

  8. A final choice: choose between either a single PDF document, or a PDF package, which comes with the option of creating a specialized cover sheet. When finished, hit 'Create', and save to your preferred location.

    • Tips & Warnings

Double check the PDF documents prior to merging to make sure all pertinent information is included. Its much easier to re-create a single PDF page than a multi-page document.

Check if a time is between two times (time DataType)

WITH CTE as
(
SELECT CAST(ShiftStart AS DATETIME) AS ShiftStart, 
CASE WHEN ShiftStart > ShiftEnd THEN CAST(ShiftEnd AS DATETIME) +1
ELSE CAST(ShiftEnd AS DATETIME) END AS ShiftEnd
FROM **TABLE_NAME**
)
SELECT * FROM CTE
WHERE 
CAST('11:00:00' AS DATETIME) BETWEEN ShiftStart AND ShiftEnd -- Start of Shift
OR CAST('23:00:00' AS DATETIME) BETWEEN ShiftStart AND ShiftEnd -- End of Shift

Event binding on dynamically created elements?

You could simply wrap your event binding call up into a function and then invoke it twice: once on document ready and once after your event that adds the new DOM elements. If you do that you'll want to avoid binding the same event twice on the existing elements so you'll need either unbind the existing events or (better) only bind to the DOM elements that are newly created. The code would look something like this:

function addCallbacks(eles){
    eles.hover(function(){alert("gotcha!")});
}

$(document).ready(function(){
    addCallbacks($(".myEles"))
});

// ... add elements ...
addCallbacks($(".myNewElements"))

A non well formed numeric value encountered

You need to set the time zone using date_default_timezone_set().

CodeIgniter query: How to move a column value to another column in the same row and save the current time in the original column?

Try like this:

$data = array('current_login' => date('Y-m-d H:i:s'));
$this->db->set('last_login', 'current_login', false);
$this->db->where('id', 'some_id');
$this->db->update('login_table', $data);

Pay particular attention to the set() call's 3rd parameter. false prevents CodeIgniter from quoting the 2nd parameter -- this allows the value to be treated as a table column and not a string value. For any data that doesn't need to special treatment, you can lump all of those declarations into the $data array.

The query generated by above code:

UPDATE `login_table`
SET last_login = current_login, `current_login` = '2018-01-18 15:24:13'
WHERE `id` = 'some_id'

ByRef argument type mismatch in Excel VBA

I changed a few things to work with Option Explicit, and the code ran fine against a cell containing "abc.123", which returned "abc.12,". There were no compile errors.

Option Explicit ' This is new

Public Function ProcessString(input_string As String) As String
    ' The temp string used throughout the function
    Dim temp_string As String
    Dim i As Integer ' This is new
    Dim return_string As String ' This is new
    For i = 1 To Len(input_string)
        temp_string = Mid(input_string, i, 1)
        If temp_string Like "[A-Z, a-z, 0-9, :, -]" Then
            return_string = return_string & temp_string
        End If
    Next i
    return_string = Mid(return_string, 1, (Len(return_string) - 1))
    ProcessString = return_string & ", "
End Function

I'll suggest you post more of your relevant code (that calls this function). You've stated that last_name is a String, but it appears that may not be the case. Step through your code line by line and ensure that this is actually the case.

jQuery .scrollTop(); + animation

for this you can use callback method

body.animate({
      scrollTop:0
    }, 500, 
    function(){} // callback method use this space how you like
);

How to get folder directory from HTML input type "file" or any other way?

Eventhough it is an old question, this may help someone.

We can choose multiple files while browsing for a file using "multiple"

<input type="file" name="datafile" size="40"  multiple> 

MySQL: Error Code: 1118 Row size too large (> 8126). Changing some columns to TEXT or BLOB

I had the issue when importing SQL-dumps (from MySQL 8) to MariaDB on MacOS (with Brew).

Start by editing your my.cnf.
If you use Brew, it's usually store at /usr/local/etc/:

pico /usr/local/etc/my.cnf

Add this to the config:

[mysqld]
innodb_log_file_size = 1024M
innodb_strict_mode = 0

Then restart MariaDB:

brew services restart mariadb

Please notice that this in a workaround and not a fix since turning of strict mode in not fixing the problem, but since it's my local environment and not a production environment i'm ok with that.

How to write to a JSON file in the correct format

This question is for ruby 1.8 but it still comes on top when googling.

in ruby >= 1.9 you can use

File.write("public/temp.json",tempHash.to_json)

other than what mentioned in other answers, in ruby 1.8 you can also use one liner form

File.open("public/temp.json","w"){ |f| f.write tempHash.to_json }

Git merge is not possible because I have unmerged files

Another potential cause for this (Intellij was involved in my case, not sure that mattered though): trying to merge in changes from a main branch into a branch off of a feature branch.

In other words, merging "main" into "current" in the following arrangement:

main
  |
  --feature
      |
      --current

I resolved all conflicts and GiT reported unmerged files and I was stuck until I merged from main into feature, then feature into current.

Update multiple columns in SQL

I did this in MySql and it updated multiple columns in a single record, so try this if you are using MySql as your server:

"UPDATE creditor_tb SET credit_amount='" & CDbl(cur_amount) & "'
                   , totalamount_to_pay='" & current_total & "',   
        WHERE credit_id='" & lbcreditId.Text & "'". 

However, I was coding in vb.net using MySql server, but you can take it to your favorite programming language as far as you are using MySql as your server.

Vagrant ssh authentication failure

For general information: by default to ssh-connect you may simply use

user: vagrant password: vagrant

https://www.vagrantup.com/docs/boxes/base.html#quot-vagrant-quot-user

First, try: to see what vagrant insecure_private_key is in your machine config

$ vagrant ssh-config

Example:

$ vagrant ssh-config
Host default
  HostName 127.0.0.1
  User vagrant
  Port 2222
  UserKnownHostsFile /dev/null
  StrictHostKeyChecking no
  PasswordAuthentication no
  IdentityFile C:/Users/konst/.vagrant.d/insecure_private_key
  IdentitiesOnly yes
  LogLevel FATAL

http://docs.vagrantup.com/v2/cli/ssh_config.html

Second, do: Change the contents of file insecure_private_key with the contents of your personal system private key

Or use: Add it to the Vagrantfile:

Vagrant.configure("2") do |config|
  config.ssh.private_key_path = "~/.ssh/id_rsa"
  config.ssh.forward_agent = true
end
  1. config.ssh.private_key_path is your local private key
  2. Your private key must be available to the local ssh-agent. You can check with ssh-add -L. If it's not listed, add it with ssh-add ~/.ssh/id_rsa
  3. Don't forget to add your public key to ~/.ssh/authorized_keys on the Vagrant VM. You can do it by copy-and-pasting or using a tool like ssh-copy-id (user: root password: vagrant port: 2222) ssh-copy-id '-p 2222 [email protected]'

If still does not work try this:

  1. Remove insecure_private_key file from c:\Users\USERNAME\.vagrant.d\insecure_private_key

  2. Run vagrant up (vagrant will be generate a new insecure_private_key file)

In other cases, it is helpful to just set forward_agent in Vagrantfile:

Vagrant::Config.run do |config|
   config.ssh.forward_agent = true
end

Useful:

Configurating git may be with git-scm.com

After setup this program and creating personal system private key will be in yours profile path: c:\users\USERNAME\.ssh\id_rsa.pub

PS: Finally - suggest you look at Ubuntu on Windows 10

Sorting hashmap based on keys

Just use a TreeMap. It implements the SortedMap interface, and thus automatically sorts the keys it contains. Your keys can just be sorted alphabetically to get the desired result, so you don't even need to provide a comparator.

HashMaps are never sorted. The only thing you coulkd do with a HashMap is get all the keys, and store them in a sorted set or in a List and sort the List.

Create table with jQuery - append

Following is done for multiple file uploads using jquery:

File input button:

<div>
 <input type="file" name="uploadFiles" id="uploadFiles" multiple="multiple" class="input-xlarge" onchange="getFileSizeandName(this);"/> 
</div>

Displaying File name and File size in a table:

<div id="uploadMultipleFilediv">
<table id="uploadTable" class="table table-striped table-bordered table-condensed"></table></div>

Javascript for getting the file name and file size:

function getFileSizeandName(input)
{
    var select = $('#uploadTable');
    //select.empty();
    var totalsizeOfUploadFiles = "";
    for(var i =0; i<input.files.length; i++)
    {
        var filesizeInBytes = input.files[i].size; // file size in bytes
        var filesizeInMB = (filesizeInBytes / (1024*1024)).toFixed(2); // convert the file size from bytes to mb
        var filename = input.files[i].name;
        select.append($('<tr><td>'+filename+'</td><td>'+filesizeInMB+'</td></tr>'));
        totalsizeOfUploadFiles = totalsizeOfUploadFiles+filesizeInMB;
        //alert("File name is : "+filename+" || size : "+filesizeInMB+" MB || size : "+filesizeInBytes+" Bytes");               
    }           
}

.gitignore exclude folder but include specific subfolder

Just another example of walking down the directory structure to get exactly what you want. Note: I didn't exclude Library/ but Library/**/*

# .gitignore file
Library/**/*
!Library/Application Support/
!Library/Application Support/Sublime Text 3/
!Library/Application Support/Sublime Text 3/Packages/
!Library/Application Support/Sublime Text 3/Packages/User/
!Library/Application Support/Sublime Text 3/Packages/User/*macro
!Library/Application Support/Sublime Text 3/Packages/User/*snippet
!Library/Application Support/Sublime Text 3/Packages/User/*settings
!Library/Application Support/Sublime Text 3/Packages/User/*keymap
!Library/Application Support/Sublime Text 3/Packages/User/*theme
!Library/Application Support/Sublime Text 3/Packages/User/**/
!Library/Application Support/Sublime Text 3/Packages/User/**/*macro
!Library/Application Support/Sublime Text 3/Packages/User/**/*snippet
!Library/Application Support/Sublime Text 3/Packages/User/**/*settings
!Library/Application Support/Sublime Text 3/Packages/User/**/*keymap
!Library/Application Support/Sublime Text 3/Packages/User/**/*theme

> git add Library

> git status

On branch master
Your branch is up-to-date with 'origin/master'.
Changes to be committed:
  (use "git reset HEAD <file>..." to unstage)

    new file:   Library/Application Support/Sublime Text 3/Packages/User/Default (OSX).sublime-keymap
    new file:   Library/Application Support/Sublime Text 3/Packages/User/ElixirSublime.sublime-settings
    new file:   Library/Application Support/Sublime Text 3/Packages/User/Package Control.sublime-settings
    new file:   Library/Application Support/Sublime Text 3/Packages/User/Preferences.sublime-settings
    new file:   Library/Application Support/Sublime Text 3/Packages/User/RESTer.sublime-settings
    new file:   Library/Application Support/Sublime Text 3/Packages/User/SublimeLinter/Monokai (SL).tmTheme
    new file:   Library/Application Support/Sublime Text 3/Packages/User/TextPastryHistory.sublime-settings
    new file:   Library/Application Support/Sublime Text 3/Packages/User/ZenTabs.sublime-settings
    new file:   Library/Application Support/Sublime Text 3/Packages/User/adrian-comment.sublime-macro
    new file:   Library/Application Support/Sublime Text 3/Packages/User/json-pretty-generate.sublime-snippet
    new file:   Library/Application Support/Sublime Text 3/Packages/User/raise-exception.sublime-snippet
    new file:   Library/Application Support/Sublime Text 3/Packages/User/trailing_spaces.sublime-settings

How can I access a hover state in reactjs?

ReactJs defines the following synthetic events for mouse events:

onClick onContextMenu onDoubleClick onDrag onDragEnd onDragEnter onDragExit
onDragLeave onDragOver onDragStart onDrop onMouseDown onMouseEnter onMouseLeave
onMouseMove onMouseOut onMouseOver onMouseUp

As you can see there is no hover event, because browsers do not define a hover event natively.

You will want to add handlers for onMouseEnter and onMouseLeave for hover behavior.

ReactJS Docs - Events

How to avoid 'cannot read property of undefined' errors?

I use undefsafe religiously. It tests each level down into your object until it either gets the value you asked for, or it returns "undefined". But never errors.

How can I set / change DNS using the command-prompt at windows 8

There are little difference in command of adding AND changing DNS-IPs:

To Add:

Syntax:
   netsh interface ipv4 add dnsserver "Network Interface Name" dns.server.ip index=1(for primary)2(for secondary)
Eg:
   netsh interface ipv4 add dnsserver "Ethernet" 8.8.8.8 index=1
  • Here, to know "Network Interface Name", type command netsh interface show interface
  • 8.8.8.8 is Google's recursive DNS server, use it, if your's not working

To Set/Change: (as OP asked this)

Syntax:
   netsh interface ipv4 set dnsservers "Network Interface Name" static dns.server.ip primary
Eg:
   netsh interface ipv4 set dnsservers "Wi-Fi" static 8.8.4.4 primary
   netsh interface ipv4 set dnsservers "Wi-Fi" dhcp
  • Last parameter can be none:disable DNS, both:set for primary and secondary DNS both, primary: for primary DNS only. You can notice here we are not using index-parameter as we did in adding DNS.

  • In the place of static you can type dhcp to make DNS setting automatic, but further parameter will not be required.


Note: Tested in windows 8,8.1 & 10.

Learning Ruby on Rails

Fantastic decision! It is extremely useful to get a grounding in Ruby before going to Rails so here is my take on the best path to Rails:

Aside from books the most important thing is to get feedback on what you are doing. To do this I recommend spending time in irc.freenode.net #ruby and #rubyonrails. It is also extremely helpful to post things you are working on or having trouble with here on stackoverflow as the comments, explanations and different way of thinking about things that people provide are invaluable.

You should also definitely check out the Ruby Rogues podcast, they provide invaluable information and the commentators are all extremely respected people in the Ruby community. And for your viewing and reading pleasure (in that order,) head over to Ryan Bates's Railscasts and then Eifion Bedford's Asciicasts.

Finally, I recommend looking into different gems on github, reading the code and then contributing to them. You don't have to get overly ambitious and do massive recodes, especially at first. Just start with small things like editing and making the README files a little easier to read.

I don't use an IDE but at Railsconf I saw a demo of Rubymine from Jetbrains and it seemed pretty amazing.

How to run a single test with Mocha?

For those who are looking to run a single file but they cannot make it work, what worked for me was that I needed to wrap my test cases in a describe suite as below and then use the describe title e.g. 'My Test Description' as pattern.

describe('My Test Description', () => {
  it('test case 1', () => {
    // My test code
  })
  it('test case 2', () => {
  // My test code
  })
})

then run

yarn test -g "My Test Description"

or

npm run test -g "My Test Description"

How do I restrict an input to only accept numbers?

Basic HTML

<input type="number" />

Basic bootstrap

<input class="form-control" type="number" value="42" id="my-id">

Bash script prints "Command Not Found" on empty lines

Add the current directory ( . ) to PATH to be able to execute a script, just by typing in its name, that resides in the current directory:

PATH=.:$PATH

What is the equivalent of ngShow and ngHide in Angular 2+?

If you are using Bootstrap is as simple as this:

<div [class.hidden]="myBooleanValue"></div>

INNER JOIN vs LEFT JOIN performance in SQL Server

From my comparisons, I find that they have the exact same execution plan. There're three scenarios:

  1. If and when they return the same results, they have the same speed. However, we must keep in mind that they are not the same queries, and that LEFT JOIN will possibly return more results (when some ON conditions aren't met) --- this is why it's usually slower.

  2. When the main table (first non-const one in the execution plan) has a restrictive condition (WHERE id = ?) and the corresponding ON condition is on a NULL value, the "right" table is not joined --- this is when LEFT JOIN is faster.

  3. As discussed in Point 1, usually INNER JOIN is more restrictive and returns fewer results and is therefore faster.

Both use (the same) indices.

How can I exclude directories from grep -R?

This one works for me:

grep <stuff> -R --exclude-dir=<your_dir>

Command line tool to dump Windows DLL version?

This function returns the ntfs Windows file details for any file using Cygwin bash (actual r-click-properties-info) to the term

Pass the files path to finfo(), can be unix path, dos path, relative or absolute. The file is converted into an absolute nix path, then checked to see if it is in-fact a regular/existing file. Then converted into an absolute windows path and sent to "wmic". Then magic, you have windows file details right in the terminal. Uses: cygwin, cygpath, sed, and awk. Needs Windows WMI "wmic.exe" to be operational. The output is corrected for easy...

$ finfo notepad.exe
$ finfo "C:\windows\system32\notepad.exe" 
$ finfo /cygdrive/c/Windows/System32/notepad.exe 
$ finfo "/cygdrive/c/Program Files/notepad.exe"
$ finfo ../notepad.exe

finfo() {
    [[ -e "$(cygpath -wa "$@")" ]] || { echo "bad-file"; return 1; }
    echo "$(wmic datafile where name=\""$(echo "$(cygpath -wa "$@")" | sed 's/\\/\\\\/g')"\" get /value)" |\
    sed 's/\r//g;s/^M$//;/^$/d' | awk -F"=" '{print $1"=""\033[1m"$2"\033[0m" }'
}

Add views below toolbar in CoordinatorLayout

To use collapsing top ToolBar or using ScrollFlags of your own choice we can do this way:From Material Design get rid of FrameLayout

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">

<androidx.coordinatorlayout.widget.CoordinatorLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.google.android.material.appbar.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <com.google.android.material.appbar.CollapsingToolbarLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:contentScrim="?attr/colorPrimary"
            app:expandedTitleGravity="top"
            app:layout_scrollFlags="scroll|enterAlways">


        <androidx.appcompat.widget.Toolbar
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:layout_collapseMode="pin">

            <ImageView
                android:id="@+id/ic_back"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:src="@drawable/ic_arrow_back" />

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="back"
                android:textSize="16sp"
                android:textStyle="bold" />

        </androidx.appcompat.widget.Toolbar>


        </com.google.android.material.appbar.CollapsingToolbarLayout>
    </com.google.android.material.appbar.AppBarLayout>

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/post_details_recycler"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical"
            android:padding="5dp"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            />

</androidx.coordinatorlayout.widget.CoordinatorLayout>

jQuery: Change button text on click

This should work for you:

    $('.SeeMore2').click(function(){
        var $this = $(this);
        $this.toggleClass('SeeMore2');
        if($this.hasClass('SeeMore2')){
            $this.text('See More');         
        } else {
            $this.text('See Less');
        }
});

Rails get index of "each" loop

The two answers are good. And I also suggest you a similar method:

<% @images.each.with_index do |page, index| %>
<% end %>

You might not see the difference between this and the accepted answer. Let me direct your eyes to these method calls: .each.with_index see how it's .each and then .with_index.

Get current date in milliseconds

You can use following methods to get current date in milliseconds.

[[NSDate date] timeIntervalSince1970];

OR

double CurrentTime = CACurrentMediaTime(); 

Source: iPhone: How to get current milliseconds?