Programs & Examples On #Epollet

Could not find module FindOpenCV.cmake ( Error in configuration process)

I am using Windows and get the same error message. I find another problem which is relevant. I defined OpenCV_DIR in my path at the end of the line. However when I typed "path" in the command line, my OpenCV_DIR was not shown. I found because Windows probably has a limit on how long the path can be, it cut my OpenCV_DIR to be only part of what I defined. So I removed some other part of the path, now it works.

Using Google Text-To-Speech in Javascript

Very easy with responsive voice. Just include the js and voila!

<script src='https://code.responsivevoice.org/responsivevoice.js'></script>

<input onclick="responsiveVoice.speak('This is the text you want to speak');" type='button' value=' Play' />

IndexError: index 1 is out of bounds for axis 0 with size 1/ForwardEuler

The problem is with your line

x=np.array ([x0*n])

Here you define x as a single-item array of -200.0. You could do this:

x=np.array ([x0,]*n)

or this:

x=np.zeros((n,)) + x0

Note: your imports are quite confused. You import numpy modules three times in the header, and then later import pylab (that already contains all numpy modules). If you want to go easy, with one single

from pylab import *

line in the top you could use all the modules you need.

Jackson JSON custom serialization for certain fields

In case you don't want to pollute your model with annotations and want to perform some custom operations, you could use mixins.

ObjectMapper mapper = new ObjectMapper();
SimpleModule simpleModule = new SimpleModule();
simpleModule.setMixInAnnotation(Person.class, PersonMixin.class);
mapper.registerModule(simpleModule);

Override age:

public abstract class PersonMixin {
    @JsonSerialize(using = PersonAgeSerializer.class)
    public String age;
}

Do whatever you need with the age:

public class PersonAgeSerializer extends JsonSerializer<Integer> {
    @Override
    public void serialize(Integer integer, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
        jsonGenerator.writeString(String.valueOf(integer * 52) + " months");
    }
}

Outline effect to text

_x000D_
_x000D_
h1 {_x000D_
   color: black;_x000D_
   -webkit-text-fill-color: white; /* Will override color (regardless of order) */_x000D_
   -webkit-text-stroke-width: 1px;_x000D_
   -webkit-text-stroke-color: black;_x000D_
}
_x000D_
<h1>Properly stroked!</h1>
_x000D_
_x000D_
_x000D_

pandas unique values multiple columns

pd.unique returns the unique values from an input array, or DataFrame column or index.

The input to this function needs to be one-dimensional, so multiple columns will need to be combined. The simplest way is to select the columns you want and then view the values in a flattened NumPy array. The whole operation looks like this:

>>> pd.unique(df[['Col1', 'Col2']].values.ravel('K'))
array(['Bob', 'Joe', 'Bill', 'Mary', 'Steve'], dtype=object)

Note that ravel() is an array method that returns a view (if possible) of a multidimensional array. The argument 'K' tells the method to flatten the array in the order the elements are stored in the memory (pandas typically stores underlying arrays in Fortran-contiguous order; columns before rows). This can be significantly faster than using the method's default 'C' order.


An alternative way is to select the columns and pass them to np.unique:

>>> np.unique(df[['Col1', 'Col2']].values)
array(['Bill', 'Bob', 'Joe', 'Mary', 'Steve'], dtype=object)

There is no need to use ravel() here as the method handles multidimensional arrays. Even so, this is likely to be slower than pd.unique as it uses a sort-based algorithm rather than a hashtable to identify unique values.

The difference in speed is significant for larger DataFrames (especially if there are only a handful of unique values):

>>> df1 = pd.concat([df]*100000, ignore_index=True) # DataFrame with 500000 rows
>>> %timeit np.unique(df1[['Col1', 'Col2']].values)
1 loop, best of 3: 1.12 s per loop

>>> %timeit pd.unique(df1[['Col1', 'Col2']].values.ravel('K'))
10 loops, best of 3: 38.9 ms per loop

>>> %timeit pd.unique(df1[['Col1', 'Col2']].values.ravel()) # ravel using C order
10 loops, best of 3: 49.9 ms per loop

Can a PDF file's print dialog be opened with Javascript?

If you know how PDF files are structured (or are willing to spend a little while reading the spec), you can do it this way.

Use the Named Action "Print" in the OpenAction field of the Catalog object; the "Print" action is undocumented, but Acrobat Reader and most of the other major readers understand it. A nice benefit of this approach is that you don't get any JavaScript warnings. See here for details: http://www.gnostice.com/nl_article.asp?id=157

To make it even shinier, I added a second Action, URI, directing the reader to go back to the page that originated the request. Then I attached this Action to the first Named action using its Next field. With content disposition set to "inline", this makes it so that when the user clicks on the print link:

  1. It opens up Adobe Reader in the same tab and loads the file
  2. It immediately shows the print dialog
  3. As soon as the Print dialog is closed (whether they hit "OK" or "cancel"), the browser tab goes back to the webpage

I was able to do all these changes in Ruby easily enough using only the File and IO modules; I opened the PDF I had generated with an external tool, followed the xref to the existing Catalog section, then appended a new section onto the PDF with an updated Catalog object containing my special OpenAction line, and also the new Action objects.

Because of PDF's incremental revision features, you don't have to make any changes to the existing data to do this, just append an additional section to the end.

Operator overloading ==, !=, Equals

In fact, this is a "how to" subject. So, here is the reference implementation:

    public class BOX
    {
        double height, length, breadth;

        public static bool operator == (BOX b1, BOX b2)
        {
            if ((object)b1 == null)
                return (object)b2 == null;

            return b1.Equals(b2);
        }

        public static bool operator != (BOX b1, BOX b2)
        {
            return !(b1 == b2);
        }

        public override bool Equals(object obj)
        {
            if (obj == null || GetType() != obj.GetType())
                return false;

            var b2 = (BOX)obj;
            return (length == b2.length && breadth == b2.breadth && height == b2.height);
        }

        public override int GetHashCode()
        {
            return height.GetHashCode() ^ length.GetHashCode() ^ breadth.GetHashCode();
        }
    }

REF: https://msdn.microsoft.com/en-us/library/336aedhh(v=vs.100).aspx#Examples

UPDATE: the cast to (object) in the operator == implementation is important, otherwise, it would re-execute the operator == overload, leading to a stackoverflow. Credits to @grek40.

This (object) cast trick is from Microsoft String == implementaiton. SRC: https://github.com/Microsoft/referencesource/blob/master/mscorlib/system/string.cs#L643

COALESCE Function in TSQL

I've been told that COALESCE is less costly than ISNULL, but research doesn't indicate that. ISNULL takes only two parameters, the field being evaluated for NULL, and the result you want if it is evaluated as NULL. COALESCE will take any number of parameters, and return the first value encountered that isn't NULL.

There's a much more thorough description of the details here http://www.mssqltips.com/sqlservertip/2689/deciding-between-coalesce-and-isnull-in-sql-server/

Catch multiple exceptions at once?

It is worth mentioning here. You can respond to the multiple combinations (Exception error and exception.message).

I ran into a use case scenario when trying to cast control object in a datagrid, with either content as TextBox, TextBlock or CheckBox. In this case the returned Exception was the same, but the message varied.

try
{
 //do something
}
catch (Exception ex) when (ex.Message.Equals("the_error_message1_here"))
{
//do whatever you like
} 
catch (Exception ex) when (ex.Message.Equals("the_error_message2_here"))
{
//do whatever you like
} 

How to get a substring between two strings in PHP?

It can be easily done using this small function:

function getString($string, $from, $to) {
    $str = explode($from, $string);
    $str = explode($to, $str[1]);
    return $s[0];
}
$myString = "<html>Some code</html>";
print getString($myString, '<html>', '</html>');

// Prints: Some code

Highlight Bash/shell code in Markdown files

If I need only to highlight the first word as a command, I often use properties:

```properties
npm run build
```  

I obtain something like:

npm run build

Setting the User-Agent header for a WebClient request

This worked for me:

var message = new HttpRequestMessage(method, url);
message.Headers.TryAddWithoutValidation("user-agent", "<user agent header value>");
var client = new HttpClient();
var response = await client.SendAsync(message);

Here you can find the documentation for TryAddWithoutValidation

How to use a App.config file in WPF applications?

You have to add the reference to System.configuration in your solution. Also, include using System.Configuration;. Once you do that, you'll have access to all the configuration settings.

Django TemplateDoesNotExist?

Find this tuple:

    import os
    SETTINGS_PATH = os.path.dirname(os.path.dirname(__file__))

    TEMPLATES = [
        {
            'BACKEND': 'django.template.backends.django.DjangoTemplates',
            'DIRS': [],
            'APP_DIRS': True,
            'OPTIONS': {
                'context_processors': [
                    'django.template.context_processors.debug',
                    'django.template.context_processors.request',
                    'django.contrib.auth.context_processors.auth',
                    'django.contrib.messages.context_processors.messages',
                ],
            },
        },
    ]

You need to add to 'DIRS' the string

"os.path.join(SETTINGS_PATH, 'templates')"

So altogether you need:

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [os.path.join(SETTINGS_PATH, 'templates')],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

Find index of last occurrence of a substring in a string

Use .rfind():

>>> s = 'hello'
>>> s.rfind('l')
3

Also don't use str as variable name or you'll shadow the built-in str().

IIS7 Settings File Locations

It sounds like you're looking for applicationHost.config, which is located in C:\Windows\System32\inetsrv\config.

Yes, it's an XML file, and yes, editing the file by hand will affect the IIS config after a restart. You can think of IIS Manager as a GUI front-end for editing applicationHost.config and web.config.

A Generic error occurred in GDI+ in Bitmap.Save method

I always check/test these:

  • Does the path + filename contain illegal characters for the given filesystem?
  • Does the file already exist? (Bad)
  • Does the path already exist? (Good)
  • If the path is relative: am I expecting it in the right parent directory (mostly bin/Debug ;-) )?
  • Is the path writable for the program and as which user does it run? (Services can be tricky here!)
  • Does the full path really, really not contain illegal chars? (some unicode chars are close to invisible)

I never had any problems with Bitmap.Save() apart from this list.

How can I style even and odd elements?

The :nth-child(n) selector matches every element that is the nth child, regardless of type, of its parent. Odd and even are keywords that can be used to match child elements whose index is odd or even (the index of the first child is 1).

this is what you want:

<html>
    <head>
        <style>
            li { color: blue }<br>
            li:nth-child(even) { color:red }
            li:nth-child(odd) { color:green}
        </style>
    </head>
    <body>
        <ul>
            <li>ho</li>
            <li>ho</li>
            <li>ho</li>
            <li>ho</li>
            <li>ho</li>
        </ul>
    </body>
</html>

How to run SQL in shell script

Maybe it's too late for answering but, there's a working code:

sqlplus -s "/ as sysdba" << EOF
    SET HEADING OFF
    SET FEEDBACK OFF
    SET LINESIZE 3800
    SET TRIMSPOOL ON
    SET TERMOUT OFF
    SET SPACE 0
    SET PAGESIZE 0
    select (select instance_name from v\$instance) as DB_NAME,
           file_name
      from dba_data_files
     order by 2;

How can I execute a python script from an html button?

Using a UI Framework would be a lot cleaner (and involve fewer components). Here is an example using wxPython:

import wx
import os
class MyForm(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, None, wx.ID_ANY, "Launch Scripts")
        panel = wx.Panel(self, wx.ID_ANY)
        sizer = wx.BoxSizer(wx.VERTICAL)
        buttonA = wx.Button(panel, id=wx.ID_ANY, label="App A", name="MYSCRIPT")
        buttonB = wx.Button(panel, id=wx.ID_ANY, label="App B", name="MYOtherSCRIPT")
        buttonC = wx.Button(panel, id=wx.ID_ANY, label="App C", name="SomeDifferentScript")
        buttons = [buttonA, buttonB, buttonC]

        for button in buttons:
            self.buildButtons(button, sizer)

        panel.SetSizer(sizer)

    def buildButtons(self, btn, sizer):
        btn.Bind(wx.EVT_BUTTON, self.onButton)
        sizer.Add(btn, 0, wx.ALL, 5)

    def onButton(self, event):
        """
        This method is fired when its corresponding button is pressed, taking the script from it's name
        """
        button = event.GetEventObject()

        os.system('python {}.py'.format(button.GetName()))

        button_id = event.GetId()
        button_by_id = self.FindWindowById(button_id)
        print "The button you pressed was labeled: " + button_by_id.GetLabel()
        print "The button's name is " + button_by_id.GetName()

# Run the program
if __name__ == "__main__":
    app = wx.App(False)
    frame = MyForm()
    frame.Show()
    app.MainLoop()

I haven't tested this yet, and I'm sure there are cleaner ways of launching a python script form a python script, but the idea I think will still hold. Good luck!

How to run SQL script in MySQL?

I came here searching for this answer as well, and here is what I found works the best for me: Note I am using Ubuntu 16.x.x

  1. Access mysql using:

mysql -u <your_user> - p

  1. At the mysql prompt, enter:

source file_name.sql

Hope this helps.

can you add HTTPS functionality to a python flask web server?

The top-scoring answer has the right idea, but the API seems to have evolved so that it no longer works as when it was first written, in 2015.

In place of this:

from OpenSSL import SSL
context = SSL.Context(SSL.PROTOCOL_TLSv1_2)
context.use_privatekey_file('server.key')
context.use_certificate_file('server.crt')

I used this, with Python 3.7.5:

import ssl
context = ssl.SSLContext()
context.load_cert_chain('fullchain.pem', 'privkey.pem')

and then supplied the SSL context in the Flask.run call as it said:

app.run(…, ssl_context=context)

(My server.crt file is called fullchain.pem and my server.key is called privkey.pem. These files were supplied to me by my LetsEncrypt Certbot.)

When and how should I use a ThreadLocal variable?

  1. ThreadLocal in Java had been introduced on JDK 1.2 but was later generified in JDK 1.5 to introduce type safety on ThreadLocal variable.

  2. ThreadLocal can be associated with Thread scope, all the code which is executed by Thread has access to ThreadLocal variables but two thread can not see each others ThreadLocal variable.

  3. Each thread holds an exclusive copy of ThreadLocal variable which becomes eligible to Garbage collection after thread finished or died, normally or due to any Exception, Given those ThreadLocal variable doesn't have any other live references.

  4. ThreadLocal variables in Java are generally private static fields in Classes and maintain its state inside Thread.

Read more: ThreadLocal in Java - Example Program and Tutorial

How to debug Apache mod_rewrite

For basic URL resolution, use a command line fetcher like wget or curl to do the testing, rather than a manual browser. Then you don't have to clear any cache; just up arrow and Enter in a shell to re-run your test fetches.

How can I add comments in MySQL?

You can use single line comments:

-- this is a comment
# this is also a comment

Or a multiline comment:

/*
   multiline
   comment
*/

How to remove elements from a generic list while iterating over it?

Using Remove or RemoveAt on a list while iterating over that list has intentionally been made difficult, because it is almost always the wrong thing to do. You might be able to get it working with some clever trick, but it would be extremely slow. Every time you call Remove it has to scan through the entire list to find the element you want to remove. Every time you call RemoveAt it has to move subsequent elements 1 position to the left. As such, any solution using Remove or RemoveAt, would require quadratic time, O(n²).

Use RemoveAll if you can. Otherwise, the following pattern will filter the list in-place in linear time, O(n).

// Create a list to be filtered
IList<int> elements = new List<int>(new int[] {1, 2, 3, 4, 5, 6, 7, 8, 9, 10});
// Filter the list
int kept = 0;
for (int i = 0; i < elements.Count; i++) {
    // Test whether this is an element that we want to keep.
    if (elements[i] % 3 > 0) {
        // Add it to the list of kept elements.
        elements[kept] = elements[i];
        kept++;
    }
}
// Unfortunately IList has no Resize method. So instead we
// remove the last element of the list until: elements.Count == kept.
while (kept < elements.Count) elements.RemoveAt(elements.Count-1);

How to build x86 and/or x64 on Windows from command line with CMAKE?

Besides CMAKE_GENERATOR_PLATFORM variable, there is also the -A switch

cmake -G "Visual Studio 16 2019" -A Win32
cmake -G "Visual Studio 16 2019" -A x64

https://cmake.org/cmake/help/v3.16/generator/Visual%20Studio%2016%202019.html#platform-selection

  -A <platform-name>           = Specify platform name if supported by
                                 generator.

Google reCAPTCHA: How to get user response and validate in the server side?

A method I use in my login servlet to verify reCaptcha responses. Uses classes from the java.json package. Returns the API response in a JsonObject.

Check the success field for true or false

private JsonObject validateCaptcha(String secret, String response, String remoteip)
{
    JsonObject jsonObject = null;
    URLConnection connection = null;
    InputStream is = null;
    String charset = java.nio.charset.StandardCharsets.UTF_8.name();

    String url = "https://www.google.com/recaptcha/api/siteverify";
    try {            
        String query = String.format("secret=%s&response=%s&remoteip=%s", 
        URLEncoder.encode(secret, charset), 
        URLEncoder.encode(response, charset),
        URLEncoder.encode(remoteip, charset));

        connection = new URL(url + "?" + query).openConnection();
        is = connection.getInputStream();
        JsonReader rdr = Json.createReader(is);
        jsonObject = rdr.readObject();

    } catch (IOException ex) {
        Logger.getLogger(Login.class.getName()).log(Level.SEVERE, null, ex);
    }
    finally {
        if (is != null) {
            try {
                is.close();
            } catch (IOException e) {
            }

        }
    }
    return jsonObject;
}

<code> vs <pre> vs <samp> for inline and block code snippets

Consider TextArea

People finding this via Google and looking for a better way to manage the display of their snippets should also consider <textarea> which gives a lot of control over width/height, scrolling etc. Noting that @vsync mentioned the deprecated tag <xmp>, I find <textarea readonly> is an excellent substitute for displaying HTML without the need to escape anything inside it (except where </textarea> might appear within).

For example, to display a single line with controlled line wrapping, consider <textarea rows=1 cols=100 readonly> your html or etc with any characters including tabs and CrLf's </textarea>.

_x000D_
_x000D_
<textarea rows=5 cols=100 readonly>Example text with Newlines,_x000D_
tabs & space,_x000D_
  html tags etc <b>displayed</b>._x000D_
    However, note that &amp; still acts as an escape char.._x000D_
      Eg: &lt;u&gt;(text)&lt;/u&gt;_x000D_
</textarea>
_x000D_
_x000D_
_x000D_

To compare all...

_x000D_
_x000D_
<h2>Compared: TEXTAREA, XMP, PRE, SAMP, CODE</h2>_x000D_
<p>Note that CSS can be used to override default fixed space fonts in each or all these.</p>_x000D_
    _x000D_
    _x000D_
<textarea rows=5 cols=100 readonly>TEXTAREA: Example text with Newlines,_x000D_
tabs & space,_x000D_
  html tags etc <b>displayed natively</b>._x000D_
    However, note that &amp; still acts as an escape char.._x000D_
      Eg: &lt;u&gt;(text)&lt;/u&gt;</textarea>_x000D_
_x000D_
<xmp>XMP: Example text with Newlines,_x000D_
tabs & space,_x000D_
  html tags etc <b>displayed natively</b>._x000D_
    However, note that &amp; (&) will not act as an escape char.._x000D_
      Eg: &lt;u&gt;(text)&lt;/u&gt;_x000D_
</xmp>_x000D_
_x000D_
<pre>PRE: Example text with Newlines,_x000D_
tabs & space,_x000D_
  html tags etc <b>are interpreted, not displayed</b>._x000D_
    However, note that &amp; still acts as an escape char.._x000D_
      Eg: &lt;u&gt;(text)&lt;/u&gt;_x000D_
</pre>_x000D_
_x000D_
<samp>SAMP: Example text with Newlines,_x000D_
tabs & space,_x000D_
  html tags etc <b>are interpreted, not displayed</b>._x000D_
    However, note that &amp; still acts as an escape char.._x000D_
      Eg: &lt;u&gt;(text)&lt;/u&gt;_x000D_
</samp>_x000D_
_x000D_
<code>CODE: Example text with Newlines,_x000D_
tabs & space,_x000D_
  html tags etc <b>are interpreted, not displayed</b>._x000D_
    However, note that &amp; still acts as an escape char.._x000D_
      Eg: &lt;u&gt;(text)&lt;/u&gt;_x000D_
</code>
_x000D_
_x000D_
_x000D_

Get an array of list element contents in jQuery

And in clean javascript:

var texts = [], lis = document.getElementsByTagName("li");
for(var i=0, im=lis.length; im>i; i++)
  texts.push(lis[i].firstChild.nodeValue);

alert(texts);

How generate unique Integers based on GUIDs

In a static class, keep a static const integer, then add 1 to it before every single access (using a public get property). This will ensure you cycle the whole int range before you get a non-unique value.

    /// <summary>
    /// The command id to use. This is a thread-safe id, that is unique over the lifetime of the process. It changes
    /// at each access.
    /// </summary>
    internal static int NextCommandId
    {
        get
        {
            return _nextCommandId++;
        }
    }       
    private static int _nextCommandId = 0;

This will produce a unique integer value within a running process. Since you do not explicitly define how unique your integer should be, this will probably fit.

How to force a view refresh without having it trigger automatically from an observable?

In some circumstances it might be useful to simply remove the bindings and then re-apply:

ko.cleanNode(document.getElementById(element_id))
ko.applyBindings(viewModel, document.getElementById(element_id))

Import SQL dump into PostgreSQL database

Postgresql12

from sql file: pg_restore -d database < file.sql

from custom format file: pg_restore -Fc database < file.dump

jQuery multiple events to trigger the same function

You can use bind method to attach function to several events. Just pass the event names and the handler function as in this code:

$('#foo').bind('mouseenter mouseleave', function() {
  $(this).toggleClass('entered');
});

Another option is to use chaining support of jquery api.

TypeError: 'builtin_function_or_method' object is not subscriptable

I think you want

listb.pop()[0]

The expression listb.pop is a valid python expression which results in a reference to the pop method, but doesn't actually call that method. You need to add the open and close parentheses to call the method.

Should I URL-encode POST data?

General Answer

The general answer to your question is that it depends. And you get to decide by specifying what your "Content-Type" is in the HTTP headers.

A value of "application/x-www-form-urlencoded" means that your POST body will need to be URL encoded just like a GET parameter string. A value of "multipart/form-data" means that you'll be using content delimiters and NOT url encoding the content.

This answer has a much more thorough explanation if you'd like more information.


Specific Answer

For an answer specific to the PHP libraries you're using (CURL), you should read the documentation here.

Here's the relevant information:

CURLOPT_POST

TRUE to do a regular HTTP POST. This POST is the normal application/x-www-form-urlencoded kind, most commonly used by HTML forms.

CURLOPT_POSTFIELDS

The full data to post in a HTTP "POST" operation. To post a file, prepend a filename with @ and use the full path. The filetype can be explicitly specified by following the filename with the type in the format ';type=mimetype'. This parameter can either be passed as a urlencoded string like 'para1=val1&para2=val2&...' or as an array with the field name as key and field data as value. If value is an array, the Content-Type header will be set to multipart/form-data. As of PHP 5.2.0, value must be an array if files are passed to this option with the @ prefix.

What does "both" mean in <div style="clear:both">

Clear:both gives you that space between them.

For example your code:

  <div style="float:left">Hello</div>
  <div style="float:right">Howdy dere pardner</div>

Will currently display as :

Hello  ...................   Howdy dere pardner

If you add the following to above snippet,

  <div style="clear:both"></div>

In between them it will display as:

Hello ................ 
                       Howdy dere pardner

giving you that space between hello and Howdy dere pardner.

Js fiiddle http://jsfiddle.net/Qk5vR/1/

Using %s in C correctly - very basic level

%s will get all the values until it gets NULL i.e. '\0'.

char str1[] = "This is the end\0";
printf("%s",str1);

will give

This is the end

char str2[] = "this is\0 the end\0";
printf("%s",str2);

will give

this is

Likelihood of collision using most significant bits of a UUID in Java

According to the documentation, the static method UUID.randomUUID() generates a type 4 UUID.

This means that six bits are used for some type information and the remaining 122 bits are assigned randomly.

The six non-random bits are distributed with four in the most significant half of the UUID and two in the least significant half. So the most significant half of your UUID contains 60 bits of randomness, which means you on average need to generate 2^30 UUIDs to get a collision (compared to 2^61 for the full UUID).

So I would say that you are rather safe. Note, however that this is absolutely not true for other types of UUIDs, as Carl Seleborg mentions.

Incidentally, you would be slightly better off by using the least significant half of the UUID (or just generating a random long using SecureRandom).

Reference jars inside a jar

if you do not want to create a custom class loader. You can read the jar file stream. And transfer it to a File object. Then you can get the url of the File. Send it to the URLClassLoader, you can load the jar file as you want. sample:

InputStream resourceAsStream = this.getClass().getClassLoader().getResourceAsStream("example"+ ".jar");
final File tempFile = File.createTempFile("temp", ".jar");
tempFile.deleteOnExit();  // you can delete the temp file or not
try (FileOutputStream out = new FileOutputStream(tempFile)) {
    IOUtils.copy(resourceAsStream, out);
}
IOUtils.closeQuietly(resourceAsStream);
URL url = tempFile.toURI().toURL();
URLClassLoader urlClassLoader = new URLClassLoader(new URL[]{url});
urlClassLoader.loadClass()
...

SQL Developer with JDK (64 bit) cannot find JVM

I know that people may frown on a youtube example but this worked for me and I was getting the same issue https://www.youtube.com/watch?v=ex1dyu0Px8U

It will direct you to add the correct Environmental Variables for the JDK.

System Properties>Advanced>Environment Variables>Path> \sqldeveloper\jdk\bin AND \sqldeveloper\jdk\bin\server

Calculate a MD5 hash from a string

Idk anything about 16 character hex strings....

using System;
using System.Security.Cryptography;
using System.Text;

But here is mine for creating MD5 hash in one line.

string hash = BitConverter.ToString(MD5.Create().ComputeHash(Encoding.ASCII.GetBytes("THIS STRING TO MD5"))).Replace("-","");

Getting Excel to refresh data on sheet from within VBA

This should do the trick...

'recalculate all open workbooks
Application.Calculate

'recalculate a specific worksheet
Worksheets(1).Calculate

' recalculate a specific range
Worksheets(1).Columns(1).Calculate

Appending an id to a list if not already present in a string

If you really don't want to change your structure, or at least create a copy of it containing the same data (e.g. make a class property with a setter and getter that read from/write to that string behind the scenes), then you can use a regular expression to check if an item is in that "list" at any given time, and if not, append it to the "list" as a separate element.

if not re.match("\b{}\b".format(348521), some_list[0]): some_list.append(348521)

This is probably faster than converting it to a set every time you want to check if an item is in it. But using set as others have suggested here is a million times better.

jQuery Ajax simple call

You could also make the ajax call more generic, reusable, so you can call it from different CRUD(create, read, update, delete) tasks for example and treat the success cases from those calls.

makePostCall = function (url, data) { // here the data and url are not hardcoded anymore
   var json_data = JSON.stringify(data);

    return $.ajax({
        type: "POST",
        url: url,
        data: json_data,
        dataType: "json",
        contentType: "application/json;charset=utf-8"
    });
}

// and here a call example
makePostCall("index.php?action=READUSERS", {'city' : 'Tokio'})
    .success(function(data){
               // treat the READUSERS data returned
   })
    .fail(function(sender, message, details){
           alert("Sorry, something went wrong!");
  });

How do I create and store md5 passwords in mysql

you have to reason in terms of hased password:

store the password as md5('bob123'); when bob is register to your app

$query = "INSERT INTO users (username,password) VALUES('bob','".md5('bob123')."');

then, when bob is logging-in:

$query = "SELECT * FROM users WHERE username = 'bob' AND password = '".md5('bob123')."';

obvioulsy use variables for username and password, these queries are generated by php and then you can execute them on mysql

How to access Session variables and set them in javascript?

Possibly some mileage with this approach. This seems to get the date back to a session variable. The string it returns displays the javascript date but when I try to manipulate the string it displays the javascript code.

ob_start();
?>
<script type="text/javascript">
    var d = new Date();
    document.write(d);
</script>
<?
$_SESSION["date"]  = ob_get_contents();
ob_end_clean();
echo $_SESSION["date"]; // displays the date
echo substr($_SESSION["date"],28); 
// displays 'script"> var d = new Date(); document.write(d);'

What is the best open-source java charting library? (other than jfreechart)

There is JChart which is all open source. I'm not sure exactly what you are graphing and how you are graphing it (servlets, swing, etc) so I would say just look at a couple different ones and see which works for you.

http://sourceforge.net/projects/jchart/

I've also used JGraph but I've only used their commercial version. They do offer an open source version however:

http://www.jgraph.com/jgraph.html

Defining Z order of views of RelativeLayout in Android

Thought I'd add an answer since the introduction of the

android:translationZ

XML field changed things a tad. The other answers that suggest running

childView1.bringToFront();

parentView.invalidate();

are totally spot on EXCEPT for that this code will NOT bring childView1 in front of any view with a hardcoded android:translationZ in the XML file. I was having problems with this, and once I removed this field from the other views, bringToFront() worked just fine.

Allow only numbers to be typed in a textbox

You could subscribe for the onkeypress event:

<input type="text" class="textfield" value="" id="extra7" name="extra7" onkeypress="return isNumber(event)" />

and then define the isNumber function:

function isNumber(evt) {
    evt = (evt) ? evt : window.event;
    var charCode = (evt.which) ? evt.which : evt.keyCode;
    if (charCode > 31 && (charCode < 48 || charCode > 57)) {
        return false;
    }
    return true;
}

You can see it in action here.

Postgresql Windows, is there a default password?

Try this:

Open PgAdmin -> Files -> Open pgpass.conf

You would get the path of pgpass.conf at the bottom of the window. Go to that location and open this file, you can find your password there.

Reference

If the above does not work, you may consider trying this:

 1. edit pg_hba.conf to allow trust authorization temporarily
 2. Reload the config file (pg_ctl reload)
 3. Connect and issue ALTER ROLE / PASSWORD to set the new password
 4. edit pg_hba.conf again and restore the previous settings
 5. Reload the config file again

I can’t find the Android keytool

I never installed Java, but when you install Android Studio it has its own version within the Android directory. Here is where mine is located. Your path may be similar. After that you can either put the keytool into your path, or just run it from that directory.

C:\Program Files\Android\Android Studio\jre\bin

Passing an array by reference

It is a syntax. In the function arguments int (&myArray)[100] parenthesis that enclose the &myArray are necessary. if you don't use them, you will be passing an array of references and that is because the subscript operator [] has higher precedence over the & operator.

E.g. int &myArray[100] // array of references

So, by using type construction () you tell the compiler that you want a reference to an array of 100 integers.

E.g int (&myArray)[100] // reference of an array of 100 ints

HTTP POST with URL query parameters -- good idea or not?

You want reasons? Here's one:

A web form can't be used to send a request to a page that uses a mix of GET and POST. If you set the form's method to GET, all the parameters are in the query string. If you set the form's method to POST, all the parameters are in the request body.

Source: HTML 4.01 standard, section 17.13 Form Submission

CSS: How to position two elements on top of each other, without specifying a height?

Here's some reusable css that will preserve the height of each element without using position: absolute:

.stack {
    display: grid;
}
.stack > * {
    grid-row: 1;
    grid-column: 1;
}

The first element in your stack is the background, and the second is the foreground.

AngularJS : Factory and Service?

Factory and Service is a just wrapper of a provider.

Factory

Factory can return anything which can be a class(constructor function), instance of class, string, number or boolean. If you return a constructor function, you can instantiate in your controller.

 myApp.factory('myFactory', function () {

  // any logic here..

  // Return any thing. Here it is object
  return {
    name: 'Joe'
  }
}

Service

Service does not need to return anything. But you have to assign everything in this variable. Because service will create instance by default and use that as a base object.

myApp.service('myService', function () {

  // any logic here..

  this.name = 'Joe';
}

Actual angularjs code behind the service

function service(name, constructor) {
    return factory(name, ['$injector', function($injector) {
        return $injector.instantiate(constructor);
    }]);
}

It just a wrapper around the factory. If you return something from service, then it will behave like Factory.

IMPORTANT: The return result from Factory and Service will be cache and same will be returned for all controllers.

When should i use them?

Factory is mostly preferable in all cases. It can be used when you have constructor function which needs to be instantiated in different controllers.

Service is a kind of Singleton Object. The Object return from Service will be same for all controller. It can be used when you want to have single object for entire application. Eg: Authenticated user details.

For further understanding, read

http://iffycan.blogspot.in/2013/05/angular-service-or-factory.html

http://viralpatel.net/blogs/angularjs-service-factory-tutorial/

How do I test if a recordSet is empty? isNull?

If Not temp_rst1 Is Nothing Then ...

How to plot a function curve in R

I did some searching on the web, and this are some ways that I found:

The easiest way is using curve without predefined function

curve(x^2, from=1, to=50, , xlab="x", ylab="y")

enter image description here

You can also use curve when you have a predfined function

eq = function(x){x*x}
curve(eq, from=1, to=50, xlab="x", ylab="y")

enter image description here

If you want to use ggplot,

library("ggplot2")
eq = function(x){x*x}
ggplot(data.frame(x=c(1, 50)), aes(x=x)) + 
  stat_function(fun=eq)

enter image description here

setOnItemClickListener on custom ListView

If in the listener you get the root layout of the item (say itemLayout), and you gave some id's to the textviews, you can then get them with something like itemLayout.findViewById(R.id.textView1).

Twig for loop for arrays with keys

I found the answer :

{% for key,value in array_path %}
    Key : {{ key }}
    Value : {{ value }}
{% endfor %}

How to detect if multiple keys are pressed at once using JavaScript?

This is not a universal method, but it's usefull in some cases. It's usefull for combinations like CTRL + something or Shift + something or CTRL + Shift + something, etc.

Example: When you want to print a page using CTRL + P, first key pressed is always CTRL followed by P. Same with CTRL + S, CTRL + U and other combinations.

_x000D_
_x000D_
document.addEventListener('keydown',function(e){
      
    //SHIFT + something
    if(e.shiftKey){
        switch(e.code){

            case 'KeyS':
                console.log('Shift + S');
                break;

        }
    }

    //CTRL + SHIFT + something
    if(e.ctrlKey && e.shiftKey){
        switch(e.code){

            case 'KeyS':
                console.log('CTRL + Shift + S');
                break;

        }
    }

});
_x000D_
_x000D_
_x000D_

forEach is not a function error with JavaScript array

parent.children is a HTMLCollection which is array-like object. First, you have to convert it to a real Array to use Array.prototype methods.

const parent = this.el.parentElement
console.log(parent.children)
[].slice.call(parent.children).forEach(child => {
  console.log(child)
})

Replace spaces with dashes and make all letters lower-case

_x000D_
_x000D_
var str = "Tatwerat Development Team";_x000D_
str = str.replace(/\s+/g, '-');_x000D_
console.log(str);_x000D_
console.log(str.toLowerCase())
_x000D_
_x000D_
_x000D_

Bootstrap - Removing padding or margin when screen size is smaller

.container-fluid {
    margin-right: auto;
    margin-left: auto;
    padding-left:0px;
    padding-right:0px;
}

How to add hours to current time in python

Import datetime and timedelta:

>>> from datetime import datetime, timedelta
>>> str(datetime.now() + timedelta(hours=9))[11:19]
'01:41:44'

But the better way is:

>>> (datetime.now() + timedelta(hours=9)).strftime('%H:%M:%S')
'01:42:05'

You can refer strptime and strftime behavior to better understand how python processes dates and time field

Why are my PowerShell scripts not running?

I was able to bypass this error by invoking PowerShell like this:

powershell -executionpolicy bypass -File .\MYSCRIPT.ps1

That is, I added the -executionpolicy bypass to the way I invoked the script.

This worked on Windows 7 Service Pack 1. I am new to PowerShell, so there could be caveats to doing that that I am not aware of.

[Edit 2017-06-26] I have continued to use this technique on other systems including Windows 10 and Windows 2012 R2 without issue.

Here is what I am using now. This keeps me from accidentally running the script by clicking on it. When I run it in the scheduler I add one argument: "scheduler" and that bypasses the prompt.

This also pauses the window at the end so I can see the output of PowerShell.

if NOT "%1" == "scheduler" (
   @echo looks like you started the script by clicking on it.
   @echo press space to continue or control C to exit.
   pause
)

C:
cd \Scripts

powershell -executionpolicy bypass -File .\rundps.ps1

set psexitcode=%errorlevel%

if NOT "%1" == "scheduler" (
   @echo Powershell finished.  Press space to exit.
   pause
)

exit /b %psexitcode%

Using "&times" word in html changes to ×

You need to escape:

<div class="test">&amp;times</div>

And then read the value using text() to get the unescaped value:

alert($(".test").text()); // outputs: &times

Deleting an element from an array in PHP

I came here because I wanted to see if there was a more elegant solution to this problem than using unset($arr[$i]). To my disappointment these answers are either wrong or do not cover every edge case.

Here is why array_diff() does not work. Keys are unique in the array, while elements are not always unique.

$arr = [1,2,2,3];

foreach($arr as $i => $n){
    $b = array_diff($arr,[$n]);
    echo "\n".json_encode($b);
}

Results...

[2,2,3]
[1,3]
[1,2,2] 

If two elements are the same they will be remove. This also applies for array_search() and array_flip().

I saw a lot of answers with array_slice() and array_splice(), but these functions only work with numeric arrays. All the answers I am aware if here does not answer the question, and so here is a solution that will work.

$arr = [1,2,3];

foreach($arr as $i => $n){
    $b = array_merge(array_slice($arr,0,$i),array_slice($arr,$i+1));
    echo "\n".json_encode($b);
}

Results...

[2,3];
[1,3];
[1,2];

Since unset($arr[$i]) will work on both associative array and numeric arrays this still does not answer the question.

This solution is to compare the keys and with a tool that will handle both numeric and associative arrays. I use array_diff_uassoc() for this. This function compares the keys in a call back function.

$arr = [1,2,2,3];
//$arr = ['a'=>'z','b'=>'y','c'=>'x','d'=>'w'];
foreach($arr as $key => $n){
    $b = array_diff_uassoc($arr, [$key=>$n], function($a,$b) {
        if($a != $b){
            return 1;
        }
    });
    echo "\n".json_encode($b);
}    

Results.....

[2,2,3];
[1,2,3];
[1,2,2];

['b'=>'y','c'=>'x','d'=>'w'];
['a'=>'z','c'=>'x','d'=>'w'];
['a'=>'z','b'=>'y','d'=>'w'];
['a'=>'z','b'=>'y','c'=>'x'];

Adding an arbitrary line to a matplotlib plot in ipython notebook

Matplolib now allows for 'annotation lines' as the OP was seeking. The annotate() function allows several forms of connecting paths and a headless and tailess arrow, i.e., a simple line, is one of them.

ax.annotate("",
            xy=(0.2, 0.2), xycoords='data',
            xytext=(0.8, 0.8), textcoords='data',
            arrowprops=dict(arrowstyle="-",
                      connectionstyle="arc3, rad=0"),
            )

In the documentation it says you can draw only an arrow with an empty string as the first argument.

From the OP's example:

%matplotlib notebook
import numpy as np
import matplotlib.pyplot as plt

np.random.seed(5)
x = np.arange(1, 101)
y = 20 + 3 * x + np.random.normal(0, 60, 100)
plt.plot(x, y, "o")


# draw vertical line from (70,100) to (70, 250)
plt.annotate("",
              xy=(70, 100), xycoords='data',
              xytext=(70, 250), textcoords='data',
              arrowprops=dict(arrowstyle="-",
                              connectionstyle="arc3,rad=0."), 
              )

# draw diagonal line from (70, 90) to (90, 200)
plt.annotate("",
              xy=(70, 90), xycoords='data',
              xytext=(90, 200), textcoords='data',
              arrowprops=dict(arrowstyle="-",
                              connectionstyle="arc3,rad=0."), 
              )

plt.show()

Example inline image

Just as in the approach in gcalmettes's answer, you can choose the color, line width, line style, etc..

Here is an alteration to a portion of the code that would make one of the two example lines red, wider, and not 100% opaque.

# draw vertical line from (70,100) to (70, 250)
plt.annotate("",
              xy=(70, 100), xycoords='data',
              xytext=(70, 250), textcoords='data',
              arrowprops=dict(arrowstyle="-",
                              edgecolor = "red",
                              linewidth=5,
                              alpha=0.65,
                              connectionstyle="arc3,rad=0."), 
              )

You can also add curve to the connecting line by adjusting the connectionstyle.

What is “2's Complement”?

Many of the answers so far nicely explain why two's complement is used to represent negative number, but do not tell us what two's complement number is, particularly not why a '1' is added, and in fact often added in a wrong way.

The confusion comes from a poor understanding of the definition of a complement number. A complement is the missing part that would make something complete.

The radix complement of an n digit number x in radix b is, by definition, b^n-x. In binary 4 is represent by 100, which has 3 digits (n=3) and a radix of 2 (b=2). So its radix complement is b^n-x = 2^3-4=8-4=4 (or 100 in binary).

However, in binary obtaining a radix's complement is not as easy as getting its diminished radix complement, which is defined as (b^n-1)-y, just 1 less than that of radix complement. To get a diminished radix complement, you simply flip all the digits.

100 -> 011 (diminished (one's) radix complement)

to obtain the radix (two's) complement, we simply add 1, as the definition defined.

011 +1 ->100 (two's complement).

Now with this new understanding, let's take a look of the example given by Vincent Ramdhanie (see above second response)

/* start of Vincent

Converting 1111 to decimal:

The number starts with 1, so it's negative, so we find the complement of 1111, which is 0000. Add 1 to 0000, and we obtain 0001. Convert 0001 to decimal, which is 1. Apply the sign = -1. Tada!

end of Vincent */

Should be understood as

The number starts with 1, so it's negative. So we know it is a two's complement of some value x. To find the x represented by its two's complement, we first need find its 1's complement.

two's complement of x: 1111 one's complement of x: 1111-1 ->1110; x = 0001, (flip all digits)

apply the sign -, and the answer =-x =-1.

How do you perform a left outer join using linq extension methods

Group Join method is unnecessary to achieve joining of two data sets.

Inner Join:

var qry = Foos.SelectMany
            (
                foo => Bars.Where (bar => foo.Foo_id == bar.Foo_id),
                (foo, bar) => new
                    {
                    Foo = foo,
                    Bar = bar
                    }
            );

For Left Join just add DefaultIfEmpty()

var qry = Foos.SelectMany
            (
                foo => Bars.Where (bar => foo.Foo_id == bar.Foo_id).DefaultIfEmpty(),
                (foo, bar) => new
                    {
                    Foo = foo,
                    Bar = bar
                    }
            );

EF and LINQ to SQL correctly transform to SQL. For LINQ to Objects it is beter to join using GroupJoin as it internally uses Lookup. But if you are querying DB then skipping of GroupJoin is AFAIK as performant.

Personlay for me this way is more readable compared to GroupJoin().SelectMany()

Finding rows containing a value (or values) in any column

How about

apply(df, 1, function(r) any(r %in% c("M017", "M018")))

The ith element will be TRUE if the ith row contains one of the values, and FALSE otherwise. Or, if you want just the row numbers, enclose the above statement in which(...).

Search text in fields in every table of a MySQL database

I modified the PHP answer of Olivier a bit to:

  • print out the results in which the string was found
  • omit tables without results
  • also show output if column names match the search input
  • show total number of results

    function searchAllDB($search){
        global $mysqli;
    
        $out = "";
        $total = 0;
        $sql = "SHOW TABLES";
        $rs = $mysqli->query($sql);
        if($rs->num_rows > 0){
            while($r = $rs->fetch_array()){
                $table = $r[0];
                $sql_search = "select * from ".$table." where ";
                $sql_search_fields = Array();
                $sql2 = "SHOW COLUMNS FROM ".$table;
                $rs2 = $mysqli->query($sql2);
                if($rs2->num_rows > 0){
                    while($r2 = $rs2->fetch_array()){
                        $colum = $r2[0];
                        $sql_search_fields[] = $colum." like('%".$search."%')";
                        if(strpos($colum,$search))
                        {
                            echo "FIELD NAME: ".$colum."\n";
                        }
                    }
                    $rs2->close();
                }
                $sql_search .= implode(" OR ", $sql_search_fields);
                $rs3 = $mysqli->query($sql_search);
                if($rs3 && $rs3->num_rows > 0)
                {
                    $out .= $table.": ".$rs3->num_rows."\n";
                    if($rs3->num_rows > 0){
                        $total += $rs3->num_rows;
                        $out.= print_r($rs3->fetch_all(),1);
                        $rs3->close();
                    }
                }
            }
            $out .= "\n\nTotal results:".$total;
            $rs->close();
        }
        return $out;
    }
    

How to write an inline IF statement in JavaScript?

<div id="ABLAHALAHOO">8008</div>
<div id="WABOOLAWADO">1110</div>

parseInt( $( '#ABLAHALAHOO' ).text()) > parseInt( $( '#WABOOLAWADO ).text()) ? alert( 'Eat potato' ) : alert( 'You starve' );

How to Consume WCF Service with Android

From my recent experience i would recommend ksoap library to consume a Soap WCF Service, its actually really easy, this anddev thread migh help you out too.

Java String to Date object of the format "yyyy-mm-dd HH:mm:ss"

its work for me SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); sdf.format(new Date));

PHP - cannot use a scalar as an array warning

Also make sure that you don't declare it an array and then try to assign something else to the array like a string, float, integer. I had that problem. If you do some echos of output I was seeing what I wanted the first time, but not after another pass of the same code.

I do not understand how execlp() works in Linux

this prototype:

  int execlp(const char *file, const char *arg, ...);

Says that execlp ìs a variable argument function. It takes 2 const char *. The rest of the arguments, if any, are the additional arguments to hand over to program we want to run - also char * - all these are C strings (and the last argument must be a NULL pointer)

So, the file argument is the path name of an executable file to be executed. arg is the string we want to appear as argv[0] in the executable. By convention, argv[0] is just the file name of the executable, normally it's set to the same as file.

The ... are now the additional arguments to give to the executable.

Say you run this from a commandline/shell:

$ ls

That'd be execlp("ls", "ls", (char *)NULL); Or if you run

$ ls -l /

That'd be execlp("ls", "ls", "-l", "/", (char *)NULL);

So on to execlp("/bin/sh", ..., "ls -l /bin/??", ...);

Here you are going to the shell, /bin/sh , and you're giving the shell a command to execute. That command is "ls -l /bin/??". You can run that manually from a commandline/shell:

 $ ls -l /bin/??

Now, how do you run a shell and tell it to execute a command ? You open up the documentation/man page for your shell and read it.

What you want to run is:

$ /bin/sh -c "ls -l /bin/??"

This becomes

  execlp("/bin/sh","/bin/sh", "-c", "ls -l /bin/??", (char *)NULL);

Side note: The /bin/?? is doing pattern matching, this pattern matching is done by the shell, and it expands to all files under /bin/ with 2 characters. If you simply did

  execlp("ls","ls", "-l", "/bin/??", (char *)NULL);

Probably nothing would happen (unless there's a file actually named /bin/??) as there's no shell that interprets and expands /bin/??

How to compare DateTime in C#?

MuSTaNG's answer says it all, but I am still adding it to make it a little more elaborate, with links and all.


The conventional operators

are available for DateTime since .NET Framework 1.1. Also, addition and subtraction of DateTime objects are also possible using conventional operators + and -.

One example from MSDN:

Equality:
System.DateTime april19 = new DateTime(2001, 4, 19);
System.DateTime otherDate = new DateTime(1991, 6, 5);

// areEqual gets false.
bool areEqual = april19 == otherDate;

otherDate = new DateTime(2001, 4, 19);
// areEqual gets true.
areEqual = april19 == otherDate;

Other operators can be used likewise.

Here is the list all operators available for DateTime.

Stop node.js program from command line

if you are using VS Code and terminal select node from the right side dropdown first and then do Ctrl + C. Then It will work

enter image description here

Press y when you are prompted.

enter image description here

Thanks

MySQL Orderby a number, Nulls last

I found this to be a good solution for the most part:

SELECT * FROM table ORDER BY ISNULL(field), field ASC;

Looking for simple Java in-memory cache

Try Ehcache? It allows you to plug in your own caching expiry algorithms so you could control your peek functionality.

You can serialize to disk, database, across a cluster etc...

How to use a class object in C++ as a function parameter

I was asking the same too. Another solution is you could overload your method:

void remove_id(EmployeeClass);
void remove_id(ProductClass);
void remove_id(DepartmentClass);

in the call the argument will fit accordingly the object you pass. but then you will have to repeat yourself

void remove_id(EmployeeClass _obj) {
    int saveId = _obj->id;
    ...
};

void remove_id(ProductClass _obj) {
    int saveId = _obj->id;
    ...
};

void remove_id(DepartmentClass _obj) {
    int saveId = _obj->id;
    ...
};

What are the differences between LDAP and Active Directory?

LDAP sits on top of the TCP/IP stack and controls internet directory access. It is environment agnostic.

AD & ADSI is a COM wrapper around the LDAP layer, and is Windows specific.

You can see Microsoft's explanation here.

Getting an element from a Set

There would be no point of getting the element if it is equal. A Map is better suited for this usecase.


If you still want to find the element you have no other option but to use the iterator:

public static void main(String[] args) {

    Set<Foo> set = new HashSet<Foo>();
    set.add(new Foo("Hello"));

    for (Iterator<Foo> it = set.iterator(); it.hasNext(); ) {
        Foo f = it.next();
        if (f.equals(new Foo("Hello")))
            System.out.println("foo found");
    }
}

static class Foo {
    String string;
    Foo(String string) {
        this.string = string;
    }
    @Override
    public int hashCode() { 
        return string.hashCode(); 
    }
    @Override
    public boolean equals(Object obj) {
        return string.equals(((Foo) obj).string);
    }
}

Python element-wise tuple operations like sum

In case someone need to average a list of tuples:

import operator 
from functools import reduce
tuple(reduce(lambda x, y: tuple(map(operator.add, x, y)),list_of_tuples))

How to concatenate int values in java?

just to not forget the format method

String s = String.format("%s%s%s%s%s", a, b, c, d, e);

(%1.1s%1.1s%1.1s%1.1s%1.1s if you only want the first digit of each number...)

python to arduino serial read & write

First you have to install a module call Serial. To do that go to the folder call Scripts which is located in python installed folder. If you are using Python 3 version it's normally located in location below,

C:\Python34\Scripts  

Once you open that folder right click on that folder with shift key. Then click on 'open command window here'. After that cmd will pop up. Write the below code in that cmd window,

pip install PySerial

and press enter.after that PySerial module will be installed. Remember to install the module u must have an INTERNET connection.


after successfully installed the module open python IDLE and write down the bellow code and run it.

import serial
# "COM11" is the port that your Arduino board is connected.set it to port that your are using        
ser = serial.Serial("COM11", 9600)
while True:
    cc=str(ser.readline())
    print(cc[2:][:-5])   

Javascript to check whether a checkbox is being checked or unchecked

To toggle a checkbox or you can use

element.checked = !element.checked;

so you could use

if (attribute == elementName)
{
    arrChecks[i].checked = !arrChecks[i].checked;
} else {
    arrChecks[i].checked = false;
}

mssql convert varchar to float

You can convert varchars to floats, and you can do it in the manner you have expressed. Your varchar must not be a numeric value. There must be something else in it. You can use IsNumeric to test it. See this:

declare @thing varchar(100)

select @thing = '122.332'

--This returns 1 since it is numeric.
select isnumeric(@thing)

--This converts just fine.
select convert(float,@thing)

select @thing = '122.332.'

--This returns 0 since it is not numeric.
select isnumeric(@thing)

--This convert throws.
select convert(float,@thing)

SQL Server 2008: how do I grant privileges to a username?

Like the following. It will make the user database owner.

EXEC sp_addrolemember N'db_owner', N'USerNAme'

Error 415 Unsupported Media Type: POST not reaching REST if JSON, but it does if XML

I had similar problem while using in postman. for POST request under header section add these as

key:valuepair

Content-Type:application/json Accept:application/json

i hope it will work.

Update Android SDK Tool to 22.0.4(Latest Version) from 22.0.1

run Android SDK Manager as administrator. that solved my problem

sudo android

How can I find the current OS in Python?

Something along the lines:

import os
if os.name == "posix":
    print(os.system("uname -a"))
# insert other possible OSes here
# ...
else:
    print("unknown OS")

ORA-01652: unable to extend temp segment by 128 in tablespace SYSTEM: How to extend?

Each tablespace has one or more datafiles that it uses to store data.

The max size of a datafile depends on the block size of the database. I believe that, by default, that leaves with you with a max of 32gb per datafile.

To find out if the actual limit is 32gb, run the following:

select value from v$parameter where name = 'db_block_size';

Compare the result you get with the first column below, and that will indicate what your max datafile size is.

I have Oracle Personal Edition 11g r2 and in a default install it had an 8,192 block size (32gb per data file).

Block Sz   Max Datafile Sz (Gb)   Max DB Sz (Tb)

--------   --------------------   --------------

   2,048                  8,192          524,264

   4,096                 16,384        1,048,528

   8,192                 32,768        2,097,056

  16,384                 65,536        4,194,112

  32,768                131,072        8,388,224

You can run this query to find what datafiles you have, what tablespaces they are associated with, and what you've currrently set the max file size to (which cannot exceed the aforementioned 32gb):

select bytes/1024/1024 as mb_size,
       maxbytes/1024/1024 as maxsize_set,
       x.*
from   dba_data_files x

MAXSIZE_SET is the maximum size you've set the datafile to. Also relevant is whether you've set the AUTOEXTEND option to ON (its name does what it implies).

If your datafile has a low max size or autoextend is not on you could simply run:

alter database datafile 'path_to_your_file\that_file.DBF' autoextend on maxsize unlimited;

However if its size is at/near 32gb an autoextend is on, then yes, you do need another datafile for the tablespace:

alter tablespace system add datafile 'path_to_your_datafiles_folder\name_of_df_you_want.dbf' size 10m autoextend on maxsize unlimited;

How to insert element as a first child?

Required here

<div class="outer">Outer Text <div class="inner"> Inner Text</div> </div>

added by

$(document).ready(function(){ $('.inner').prepend('<div class="middle">New Text Middle</div>'); });

Checking on a thread / remove from list

mythreads = threading.enumerate()

Enumerate returns a list of all Thread objects still alive. https://docs.python.org/3.6/library/threading.html

Where are Magento's log files located?

These code lines can help you quickly enable log setting in your magento site.

INSERT INTO `core_config_data` (`config_id`, `scope`, `scope_id`, `path`, `value`) VALUES
('', 'default', 0, 'dev/log/active', '1'),
('', 'default', 0, 'dev/log/file', 'system.log'),
('', 'default', 0, 'dev/log/exception_file', 'exception.log');

Then you can see them inside the folder: /var/log under root installation.

More detail in this blog

C# Linq Where Date Between 2 Dates

If you have date interval filter condition and you need to select all records which falls partly into this filter range. Assumption: records has ValidFrom and ValidTo property.

DateTime intervalDateFrom = new DateTime(1990, 01, 01);
DateTime intervalDateTo = new DateTime(2000, 01, 01);

var itemsFiltered = allItems.Where(x=> 
    (x.ValidFrom >= intervalDateFrom && x.ValidFrom <= intervalDateTo) ||
    (x.ValidTo >= intervalDateFrom && x.ValidTo <= intervalDateTo) ||
    (intervalDateFrom >= x.ValidFrom && intervalDateFrom <= x.ValidTo) ||
    (intervalDateTo >= x.ValidFrom && intervalDateTo <= x.ValidTo)
);

How can I get the session object if I have the entity-manager?

'entityManager.unwrap(Session.class)' is used to get session from EntityManager.

@Repository
@Transactional
public class EmployeeRepository {

  @PersistenceContext
  private EntityManager entityManager;

  public Session getSession() {
    Session session = entityManager.unwrap(Session.class);
    return session;
  }

  ......
  ......

}

Demo Application link.

Issue with adding common code as git submodule: "already exists in the index"

if there exists a folder named x under git control, you want add a same name submodule , you should delete folder x and commit it first.

Updated by @ujjwal-singh:

Committing is not needed, staging suffices.. git add / git rm -r

Twitter Bootstrap - full width navbar

Put your <nav>element out from the <div class='container-fluid'>. Ex :-

_x000D_
_x000D_
<nav>_x000D_
 ......nav content goes here_x000D_
<nav>_x000D_
_x000D_
<div class="container-fluid">_x000D_
  <div>_x000D_
   ........ other content goes here_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Jenkins vs Travis-CI. Which one would you use for a Open Source project?

I worked on both Travis and Jenkins: I will list down some of the features of both:

Setup CI for a project

Travis comes in first place. It's very easy to setup. Takes less than a minute to setup with GitHub.

  1. Login to GitHub
  2. Create Web Hook for Travis.
  3. Return to Travis, and login with your GitHub credentials
  4. Sync your GitHub repo and enable Push and Pull requests.

Jenkins:

  1. Create an Environment (Master Jenkins)
  2. Create web hooks
  3. Configure each job (takes time compare to Travis)

Re-running builds

Travis: Anyone with write access on GitHub can re-run the build by clicking on `restart build

Jenkins: Re-run builds based on a phrase. You provide phrase text in PR/commit description, like reverify jenkins.

Controlling environment

Travis: Travis provides hosted environment. It installs required software for every build. It’s a time-consuming process.

Jenkins: One-time setup. Installs all required software on a node/slave machine, and then builds/tests on a pre-installed environment.

Build Logs:

Travis: Supports build logs to place in Amazon S3.

Jenkins: Easy to setup with build artifacts plugin.

How do I lowercase a string in C?

to convert to lower case is equivalent to rise bit 0x60 if you restrict yourself to ASCII:

for(char *p = pstr; *p; ++p)
    *p = *p > 0x40 && *p < 0x5b ? *p | 0x60 : *p;

Twitter Bootstrap and ASP.NET GridView

You need to set useaccessibleheader attribute of the gridview to true and also then also specify a TableSection to be a header after calling the DataBind() method on you GridView object. So if your grid view is mygv

mygv.UseAccessibleHeader = True
mygv.HeaderRow.TableSection = TableRowSection.TableHeader

This should result in a proper formatted grid with thead and tbody tags

How to place the ~/.composer/vendor/bin directory in your PATH?

To put this folder on the PATH environment variable type

export PATH="$PATH:$HOME/.composer/vendor/bin"

This appends the folder to your existing PATH, however, it is only active for your current terminal session.

If you want it to be automatically set, it depends on the shell you are using. For bash, you can append this line to $HOME/.bashrc using your favorite editor or type the following on the shell

echo 'export PATH="$PATH:$HOME/.composer/vendor/bin"' >> ~/.bashrc

In order to check if it worked, logout and login again or execute

source ~/.bashrc

on the shell.

PS: For other systems where there is no ~/.bashrc, you can also put this into ~/.bash_profile

PSS: For more recent laravel you need to put $HOME/.config/composer/vendor/bin on the PATH.

PSSS: If you want to put this folder on the path also for other shells or on the GUI, you should append the said export command to ~/.profile (cf. https://help.ubuntu.com/community/EnvironmentVariables).

An "and" operator for an "if" statement in Bash

Try this:

if [ $STATUS -ne 200 -a "$STRING" != "$VALUE" ]; then

Evaluate a string with a switch in C++

You can only use switch-case on types castable to an int.

You could, however, define a std::map<std::string, std::function> dispatcher and use it like dispatcher[str]() to achieve same effect.

Random number c++ in some range

You can use the random functionality included within the additions to the standard library (TR1). Or you can use the same old technique that works in plain C:

25 + ( std::rand() % ( 63 - 25 + 1 ) )

How do I launch a program from command line without opening a new cmd window?

Just remove the double quote, this works in Windows 7:

start C:\ProgramFiles\folderName\app.exe

If you want to maximize the window, try this:

start /MAX C:\ProgramFiles\folderName\app.exe


Your command START "filepath" will start a command prompt and change the command prompt title to filepath.

Try to run start /? in windows command prompt and you will get more info.

How to install requests module in Python 3.4, instead of 2.7

i just reinstalled the pip and it works, but I still wanna know why it happened...

i used the apt-get remove --purge python-pip after I just apt-get install pyhton-pip and it works, but don't ask me why...

How to deal with INSTALL_PARSE_FAILED_INCONSISTENT_CERTIFICATES without uninstall?

This is the command to uninstall the app from device using adb:

adb uninstall <package name>

DISABLE the Horizontal Scroll

.name 
  { 
      max-width: 100%; 
       overflow-x: hidden; 
   }

You apply the above style or you can create function in javaScript to solve that problem

Comparing Dates in Oracle SQL

Single quote must be there, since date converted to character.

Select employee_id, count(*)
From Employee
Where to_char(employee_date_hired, 'DD-MON-YY') > '31-DEC-95';

bash string equality

There's no difference, == is a synonym for = (for the C/C++ people, I assume). See here, for example.

You could double-check just to be really sure or just for your interest by looking at the bash source code, should be somewhere in the parsing code there, but I couldn't find it straightaway.

How to set web.config file to show full error message

not sure if it'll work in your scenario, but try adding the following to your web.config under <system.web>:

  <system.web>
    <customErrors mode="Off" />
  ...
  </system.web>

works in my instance.

also see:

CustomErrors mode="Off"

Enable the display of line numbers in Visual Studio

Are you talking about seeing the line numbers or knowing the total number of lines in a project? Here is the 1st one

How to get the selected item of a combo box to a string variable in c#

You can use as below:

string selected = cmbbox.Text;
MessageBox.Show(selected);

Stack smashing detected

Stack Smashing here is actually caused due to a protection mechanism used by gcc to detect buffer overflow errors. For example in the following snippet:

#include <stdio.h>

void func()
{
    char array[10];
    gets(array);
}

int main(int argc, char **argv)
{
    func();
}

The compiler, (in this case gcc) adds protection variables (called canaries) which have known values. An input string of size greater than 10 causes corruption of this variable resulting in SIGABRT to terminate the program.

To get some insight, you can try disabling this protection of gcc using option -fno-stack-protector while compiling. In that case you will get a different error, most likely a segmentation fault as you are trying to access an illegal memory location. Note that -fstack-protector should always be turned on for release builds as it is a security feature.

You can get some information about the point of overflow by running the program with a debugger. Valgrind doesn't work well with stack-related errors, but like a debugger, it may help you pin-point the location and reason for the crash.

How do I view / replay a chrome network debugger har file saved with content?

HAR import works seamlessly in Firefox: Open Web Developer -> Network Tab -> HAR -> Import ... (Top-right corner of web developer tool)

HAR Import Option

The application has stopped unexpectedly: How to Debug?

  1. From the Home screen, press the Menu key.
  2. List item
  3. Touch Settings.
  4. Touch Applications.
  5. Touch Manage Applications.
  6. Touch All.
  7. Select the application that is having issues.
  8. Touch Clear data and Clear cache if they are available. This resets the app as if it was new, and may delete personal data stored in the app.

Scrolling a flexbox with overflowing content

The following CSS changes in bold (plus a bunch of content in the columns to test scrolling) will work. See the result in this Pen.

.content { flex: 1; display: flex; height: 1px; }

.column { padding: 20px; border-right: 1px solid #999; overflow: auto; }

The trick seems to be that a scrollable panel needs to have a height literally set somewhere (in this case, via its parent), not just determined by flexbox. So even height: 1px works. The flex-grow:1 will still size the panel to fit properly.

How to copy folders to docker image from Dockerfile?

Suppose you want to copy the contents from a folder where you have docker file into your container. Use ADD:

RUN mkdir /temp
ADD folder /temp/Newfolder  

it will add to your container with temp/newfolder

folder is the folder/directory where you have the dockerfile, more concretely, where you put your content and want to copy that.

Now can you check your copied/added folder by runining container and see the content using ls

How to redirect user's browser URL to a different page in Nodejs?

OP: "I would love if there were a way to do it where I didn't have to know the host address..."

response.writeHead(301, {
  Location: "http" + (request.socket.encrypted ? "s" : "") + "://" + 
    request.headers.host + newRoom
});
response.end();

How to write/update data into cells of existing XLSX workbook using xlsxwriter in python

You can do by xlwings as well

import xlwings as xw
for book in xlwings.books:
    print(book)

How to fast get Hardware-ID in C#?

Here is a DLL that shows:
* Hard drive ID (unique hardware serial number written in drive's IDE electronic chip)
* Partition ID (volume serial number)
* CPU ID (unique hardware ID)
* CPU vendor
* CPU running speed
* CPU theoretic speed
* Memory Load ( Total memory used in percentage (%) )
* Total Physical ( Total physical memory in bytes )
* Avail Physical ( Physical memory left in bytes )
* Total PageFile ( Total page file in bytes )
* Available PageFile( Page file left in bytes )
* Total Virtual( Total virtual memory in bytes )
* Available Virtual ( Virtual memory left in bytes )
* Bios unique identification numberBiosDate
* Bios unique identification numberBiosVersion
* Bios unique identification numberBiosProductID
* Bios unique identification numberBiosVideo

(text grabbed from original web site)
It works with C#.

How to define Singleton in TypeScript

This is probably the longest process to make a singleton in typescript, but in larger applications is the one that has worked better for me.

First you need a Singleton class in, let's say, "./utils/Singleton.ts":

module utils {
    export class Singleton {
        private _initialized: boolean;

        private _setSingleton(): void {
            if (this._initialized) throw Error('Singleton is already initialized.');
            this._initialized = true;
        }

        get setSingleton() { return this._setSingleton; }
    }
}

Now imagine you need a Router singleton "./navigation/Router.ts":

/// <reference path="../utils/Singleton.ts" />

module navigation {
    class RouterClass extends utils.Singleton {
        // NOTICE RouterClass extends from utils.Singleton
        // and that it isn't exportable.

        private _init(): void {
            // This method will be your "construtor" now,
            // to avoid double initialization, don't forget
            // the parent class setSingleton method!.
            this.setSingleton();

            // Initialization stuff.
        }

        // Expose _init method.
        get init { return this.init; }
    }

    // THIS IS IT!! Export a new RouterClass, that no
    // one can instantiate ever again!.
    export var Router: RouterClass = new RouterClass();
}

Nice!, now initialize or import wherever you need:

/// <reference path="./navigation/Router.ts" />

import router = navigation.Router;

router.init();
router.init(); // Throws error!.

The nice thing about doing singletons this way is that you still use all the beauty of typescript classes, it gives you nice intellisense, the singleton logic keeps someway separated and it's easy to remove if needed.

jQuery - Fancybox: But I don't want scrollbars!

Add iframe: { scrolling : 'no' } as option

example

$.fancybox({
href: 'yourUrl.html',
width: 800,
height: 415,
autoSize: false,
type : 'iframe',
iframe: {
scrolling : 'no',
preload   : true
}});

Is there a pure CSS way to make an input transparent?

input[type="text"]
{
    background: transparent;
    border: none;
}

Nobody will even know it's there.

How to access command line arguments of the caller inside a function?

My reading of the Bash Reference Manual says this stuff is captured in BASH_ARGV, although it talks about "the stack" a lot.

#!/bin/bash

function argv {
    for a in ${BASH_ARGV[*]} ; do
      echo -n "$a "
    done
    echo
}

function f {
    echo f $1 $2 $3
    echo -n f ; argv
}

function g {
    echo g $1 $2 $3
    echo -n g; argv
    f
}

f boo bar baz
g goo gar gaz

Save in f.sh

$ ./f.sh arg0 arg1 arg2
f boo bar baz
farg2 arg1 arg0 
g goo gar gaz
garg2 arg1 arg0 
f
farg2 arg1 arg0 

Why are iframes considered dangerous and a security risk?

I'm assuming cross-domain iFrame since presumably the risk would be lower if you controlled it yourself.

  • Clickjacking is a problem if your site is included as an iframe
  • A compromised iFrame could display malicious content (imagine the iFrame displaying a login box instead of an ad)
  • An included iframe can make certain JS calls like alert and prompt which could annoy your user
  • An included iframe can redirect via location.href (yikes, imagine a 3p frame redirecting the customer from bankofamerica.com to bankofamerica.fake.com)
  • Malware inside the 3p frame (java/flash/activeX) could infect your user

How do you set a default value for a MySQL Datetime column?

I'm running MySql Server 5.7.11 and this sentence:

ALTER TABLE table_name CHANGE date_column datetime NOT NULL DEFAULT '0000-00-00 00:00:00'

is not working. But the following:

ALTER TABLE table_name CHANGE date_column datetime NOT NULL DEFAULT '1000-01-01 00:00:00'

just works.

As a sidenote, it is mentioned in the mysql docs:

The DATE type is used for values with a date part but no time part. MySQL retrieves and displays DATE values in 'YYYY-MM-DD' format. The supported range is '1000-01-01' to '9999-12-31'.

even if they also say:

Invalid DATE, DATETIME, or TIMESTAMP values are converted to the “zero” value of the appropriate type ('0000-00-00' or '0000-00-00 00:00:00').

How to use sed to replace only the first occurrence in a file?

sed '0,/pattern/s/pattern/replacement/' filename

this worked for me.

example

sed '0,/<Menu>/s/<Menu>/<Menu><Menu>Sub menu<\/Menu>/' try.txt > abc.txt

Editor's note: both work with GNU sed only.

How do I use raw_input in Python 3

A reliable way to address this is

from six.moves import input

six is a module which patches over many of the 2/3 common code base pain points.

Python3 integer division

Try this:

a = 1
b = 2
int_div  = a // b

Define an <img>'s src attribute in CSS

#divID {
    background-image: url("http://imageurlhere.com");
    background-repeat: no-repeat;
    width: auto; /*or your image's width*/
    height: auto; /*or your image's height*/
    margin: 0;
    padding: 0;
}

Constructors in JavaScript objects

In most cases you have to somehow declare the property you need before you can call a method that passes in this information. If you do not have to initially set a property you can just call a method within the object like so. Probably not the most pretty way of doing this but this still works.

var objectA = {
    color: ''; 
    callColor : function(){
        console.log(this.color);
    }
    this.callColor(); 
}
var newObject = new objectA(); 

Open Source Javascript PDF viewer

There is an open source HTML5/javascript reader available called Trapeze though its still in its early stages.

Demo site: https://brendandahl.github.io/trapeze-reader/demos/

Github page: https://github.com/brendandahl/trapeze-reader

Disclaimer: I'm the author.

Regex to replace multiple spaces with a single space

We can use the following regex explained with the help of sed system command. The similar regex can be used in other languages and platforms.

Add the text into some file say test

manjeet-laptop:Desktop manjeet$ cat test
"The dog      has a long   tail, and it     is RED!"

We can use the following regex to replace all white spaces with single space

manjeet-laptop:Desktop manjeet$ sed 's/ \{1,\}/ /g' test
"The dog has a long tail, and it is RED!"

Hope this serves the purpose

position fixed is not working

Another cause could be a parent container that contains the CSS animation property. That's what it was for me.

Could not load file or assembly 'Microsoft.ReportViewer.WebForms'

You need to reference both Microsoft.ReportViewer.WebForms and Microsoft.ReportViewer.Common and set the CopyLocal property to true. This will result in the dll's being copied to our bin directory (both are necessary).

When to use Task.Delay, when to use Thread.Sleep?

Use Thread.Sleep when you want to block the current thread.

Use Task.Delay when you want a logical delay without blocking the current thread.

Efficiency should not be a paramount concern with these methods. Their primary real-world use is as retry timers for I/O operations, which are on the order of seconds rather than milliseconds.

How to do SVN Update on my project using the command line

svn update /path/to/working/copy

If subversion is not in your PATH, then of course

/path/to/subversion/svn update /path/to/working/copy

or if you are in the current root directory of your svn repo (it contains a .svn subfolder), it's as simple as

svn update

What is the difference between C and embedded C?

In the C standard, a standalone implementation doesn't have to provide all of the library functions that a hosted implementation has to provide. The C standard doesn't care about embedded, but vendors of embedded systems usually provide standalone implementations with whatever amount of libraries they're willing to provide.

C is a widely used general purpose high level programming language mainly intended for system programming.

Embedded C is an extension to C programming language that provides support for developing efficient programs for embedded devices.It is not a part of the C language

You can also refer to the articles below:

Database, Table and Column Naming Conventions?

My opinions on these are:

1) No, table names should be singular.

While it appears to make sense for the simple selection (select * from Orders) it makes less sense for the OO equivalent (Orders x = new Orders).

A table in a DB is really the set of that entity, it makes more sense once you're using set-logic:

select Orders.*
from Orders inner join Products
    on Orders.Key = Products.Key

That last line, the actual logic of the join, looks confusing with plural table names.

I'm not sure about always using an alias (as Matt suggests) clears that up.

2) They should be singular as they only hold 1 property

3) Never, if the column name is ambiguous (as above where they both have a column called [Key]) the name of the table (or its alias) can distinguish them well enough. You want queries to be quick to type and simple - prefixes add unnecessary complexity.

4) Whatever you want, I'd suggest CapitalCase

I don't think there's one set of absolute guidelines on any of these.

As long as whatever you pick is consistent across the application or DB I don't think it really matters.

How to remove line breaks from a file in Java?

You can use apache commons IOUtils to iterate through the line and append each line to StringBuilder. And don't forget to close the InputStream

StringBuilder sb = new StringBuilder();
FileInputStream fin=new FileInputStream("textfile.txt");
LineIterator lt=IOUtils.lineIterator(fin, "utf-8");
while(lt.hasNext())
{
  sb.append(lt.nextLine());
}
String text = sb.toString();
IOUtils.closeQuitely(fin);

How can I check if a date is the same day as datetime.today()?

You can set the hours, minutes, seconds and microseconds to whatever you like

datetime.datetime.today().replace(hour=0, minute=0, second=0, microsecond=0)

but trutheality's answer is probably best when they are all to be zero and you can just compare the .date()s of the times

Maybe it is faster though if you have to compare hundreds of datetimes because you only need to do the replace() once vs hundreds of calls to date()

Push JSON Objects to array in localStorage

One thing I can suggest you is to extend the storage object to handle objects and arrays.

LocalStorage can handle only strings so you can achieve that using these methods

Storage.prototype.setObj = function(key, obj) {
    return this.setItem(key, JSON.stringify(obj))
}
Storage.prototype.getObj = function(key) {
    return JSON.parse(this.getItem(key))
}

Using it every values will be converted to json string on set and parsed on get

How to write DataFrame to postgres table?

Starting from pandas 0.14 (released end of May 2014), postgresql is supported. The sql module now uses sqlalchemy to support different database flavors. You can pass a sqlalchemy engine for a postgresql database (see docs). E.g.:

from sqlalchemy import create_engine
engine = create_engine('postgresql://username:password@localhost:5432/mydatabase')
df.to_sql('table_name', engine)

You are correct that in pandas up to version 0.13.1 postgresql was not supported. If you need to use an older version of pandas, here is a patched version of pandas.io.sql: https://gist.github.com/jorisvandenbossche/10841234.
I wrote this a time ago, so cannot fully guarantee that it always works, buth the basis should be there). If you put that file in your working directory and import it, then you should be able to do (where con is a postgresql connection):

import sql  # the patched version (file is named sql.py)
sql.write_frame(df, 'table_name', con, flavor='postgresql')

Add a CSS border on hover without moving the element

Try this it might solve your problem.

Css:

.item{padding-top:1px;}

.jobs .item:hover {
    background: #e1e1e1;
    border-top: 1px solid #d0d0d0;
    padding-top:0;
}

HTML:

<div class="jobs">
    <div class="item">
        content goes here
    </div>
</div>

See fiddle for output: http://jsfiddle.net/dLDNA/

Using RegEX To Prefix And Append In Notepad++

Use a Macro.

Macro>Start Recording

Use the keyboard to make your changes in a repeatable manner e.g.

home>type "able">end>down arrow>home

Then go back to the menu and click stop recording then run a macro multiple times.

That should do it and no regex based complications!

What is http multipart request?

A HTTP multipart request is a HTTP request that HTTP clients construct to send files and data over to a HTTP Server. It is commonly used by browsers and HTTP clients to upload files to the server.

Set Encoding of File to UTF8 With BOM in Sublime Text 3

I can't set "UTF-8 with BOM" in the corner button either, but I can change it from the menu bar.

"File"->"Save with encoding"->"UTF-8 with BOM"

How do you get the logical xor of two variables in Python?

def xor(*args):
    return sum(bool(arg) for arg in args)%2

if you want only one true:

def onlyOne(*args):
    return sum(bool(arg) for arg in args)==1

excel formula to subtract number of days from a date

Here is what worked for me (Excel 14.0 - aka MS Office Pro Plus 2010):

=DATE(YEAR(A1), MONTH(A1), DAY(A1) - 16)

This takes the date (format mm/dd/yyyy) in cell A1 and subtracts 16 days with output in format of mm/dd/yyyy.

Delaying a jquery script until everything else has loaded

You can have $(document).ready() multiple times in a page. The code gets run in the sequence in which it appears.

You can use the $(window).load() event for your code since this happens after the page is fully loaded and all the code in the various $(document).ready() handlers have finished running.

$(window).load(function(){
  //your code here
});

Error 1053 the service did not respond to the start or control request in a timely fashion

In the case I ran into this morning, the culprit was a malformed config file. The config file had an close comment tag without the open comment tag. So, double check your config files for errors.

android: how to change layout on button click?

I know I'm coming to this late, but what the heck.

I've got almost the exact same code as Kris, using just one Activity but with 2 different layouts/views, and I want to switch between the layouts at will.

As a test, I added 2 menu options, each one switches the view:

public boolean onOptionsItemSelected(MenuItem item) {

        switch (item.getItemId()) {
            case R.id.item1:
                setContentView(R.layout.main);
                return true;
            case R.id.item2:
                setContentView(R.layout.alternate);
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

Note, I've got one Activity class. This works perfectly. So I have no idea why people are suggesting using different Activities / Intents. Maybe someone can explain why my code works and Kris's didn't.

CSS last-child selector: select last-element of specific class, not last child inside of parent?

Something that I think should be commented here that worked for me:

Use :last-child multiple times in the places needed so that it always gets the last of the last.

Take this for example:

_x000D_
_x000D_
.page.one .page-container .comment:last-child {_x000D_
  color: red;_x000D_
}_x000D_
.page.two .page-container:last-child .comment:last-child {_x000D_
  color: blue;_x000D_
}
_x000D_
<p> When you use .comment:last-child </p>_x000D_
<p> you only get the last comment in both parents </p>_x000D_
_x000D_
<div class="page one">_x000D_
  <div class="page-container">_x000D_
    <p class="comment"> Something </p>_x000D_
    <p class="comment"> Something </p>_x000D_
  </div>_x000D_
_x000D_
  <div class="page-container">_x000D_
    <p class="comment"> Something </p>_x000D_
    <p class="comment"> Something </p>_x000D_
  </div>_x000D_
</div>_x000D_
_x000D_
<p> When you use .page-container:last-child .comment:last-child </p>_x000D_
<p> you get the last page-container's, last comment </p>_x000D_
_x000D_
<div class="page two">_x000D_
  <div class="page-container">_x000D_
    <p class="comment"> Something </p>_x000D_
    <p class="comment"> Something </p>_x000D_
  </div>_x000D_
_x000D_
  <div class="page-container">_x000D_
    <p class="comment"> Something </p>_x000D_
    <p class="comment"> Something </p>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Tracking changes in Windows registry

I concur with Franci, all Sysinternals utilities are worth taking a look (Autoruns is a must too), and Process Monitor, which replaces the good old Filemon and Regmon is precious.

Beside the usage you want, it is very useful to see why a process fails (like trying to access a file or a registry key that doesn't exist), etc.

Prevent jQuery UI dialog from setting focus to first textbox

I was looking around for a different issue but same cause. The issue is that the dialog set focus to the first <a href="">.</a> it finds. So if you have a lot of text in your dialog and scroll bars appear you could have the situation where the scroll bar will be scrolled to the bottom. I believe this also fixes the first persons question. Although the others do as well.

The simple easy to understand fix. <a id="someid" href="#">.</a> as the first line in your dialog div.

EXAMPLE:

 <div id="dialogdiv" title="some title">
    <a id="someid" href="#">.</a>
    <p>
        //the rest of your stuff
    </p>
</div>

Where your dialog is initiated

$(somediv).dialog({
        modal: true,
        open: function () { $("#someid").hide(); otherstuff or function },
        close: function () { $("#someid").show(); otherstuff or function }
    });

The above will have nothing focused and the scroll bars will remain at the top where it belongs. The <a> gets focus but is then hidden. So the overall effect is the desired effect.

I know this is an old thread but as for as the UI docs there is no fix to this. This does not require blur or focus to work. Not sure if it is the most elegant. But it just makes sense and easy to explain to anyone.

Verilog generate/genvar in an always block

for verilog just do

parameter ROWBITS = 4;
reg [ROWBITS-1:0] temp;
always @(posedge sysclk) begin
  temp <= {ROWBITS{1'b0}}; // fill with 0
end

Looping through JSON with node.js

A little late but I believe some further clarification is given below.

You can iterate through a JSON array with a simple loop as well, like:

for(var i = 0; i < jsonArray.length; i++)
{
    console.log(jsonArray[i].attributename);
}

If you have a JSON object and you want to loop through all of its inner objects, then you first need to get all the keys in an array and loop through the keys to retrieve objects using the key names, like:

var keys = Object.keys(jsonObject);
for(var i = 0; i < keys.length; i++) 
{
    var key = keys[i];
    console.log(jsonObject.key.attributename);
}

Python: Importing urllib.quote

This is how I handle this, without using exceptions.

import sys
if sys.version_info.major > 2:  # Python 3 or later
    from urllib.parse import quote
else:  # Python 2
    from urllib import quote

Make a negative number positive

Just call Math.abs. For example:

int x = Math.abs(-5);

Which will set x to 5.

Note that if you pass Integer.MIN_VALUE, the same value (still negative) will be returned, as the range of int does not allow the positive equivalent to be represented.

Opening Chrome From Command Line

Have a look into the start command. It should do what you're trying to achieve.

Also, you might be able to leave out path to chrome. The following works on Windows 7:

start chrome "site1.com" "site2.com"

SQL - Rounding off to 2 decimal places

Declare @number float = 35.44987665;
Select round(@number,2) 

How to use LogonUser properly to impersonate domain user from workgroup client

I have been successfull at impersonating users in another domain, but only with a trust set up between the 2 domains.

var token = IntPtr.Zero;
var result = LogonUser(userID, domain, password, LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT, ref token);
if (result)
{
    return WindowsIdentity.Impersonate(token);
}

Select objects based on value of variable in object using jq

Adapted from this post on Processing JSON with jq, you can use the select(bool) like this:

$ jq '.[] | select(.location=="Stockholm")' json
{
  "location": "Stockholm",
  "name": "Walt"
}
{
  "location": "Stockholm",
  "name": "Donald"
}

How can I import Swift code to Objective-C?

Importing Swift file inside Objective-c can cause this error, if it doesn't import properly.

NOTE: You don't have to import Swift files externally, you just have to import one file which takes care of swift files.

When you Created/Copied Swift file inside Objective-C project. It would've created a bridging header automatically.

Check Objective-C Generated Interface Header Name at Targets -> Build Settings.

enter image description here

Based on above, I will import KJExpandable-Swift.h as it is.

Your's will be TargetName-Swift.h, Where TargetName differs based on your project name or another target your might have added and running on it.

As below my target is KJExpandable, so it's KJExpandable-Swift.h
enter image description here

Logging request/response messages when using HttpClient

See http://mikehadlow.blogspot.com/2012/07/tracing-systemnet-to-debug-http-clients.html

To configure a System.Net listener to output to both the console and a log file, add the following to your assembly configuration file:

<system.diagnostics>
  <trace autoflush="true" />
  <sources>
    <source name="System.Net">
      <listeners>
        <add name="MyTraceFile"/>
        <add name="MyConsole"/>
      </listeners>
    </source>
  </sources>
  <sharedListeners>
    <add
      name="MyTraceFile"
      type="System.Diagnostics.TextWriterTraceListener"
      initializeData="System.Net.trace.log" />
    <add name="MyConsole" type="System.Diagnostics.ConsoleTraceListener" />
  </sharedListeners>
  <switches>
    <add name="System.Net" value="Verbose" />
  </switches>
</system.diagnostics>

vim - How to delete a large block of text without counting the lines?

Go to the starting line and type ma (mark "a"). Then go to the last line and enter d'a (delete to mark "a").

That will delete all lines from the current to the marked one (inclusive). It's also compatible with vi as well as vim, on the off chance that your environment is not blessed with the latter.

What is ANSI format?

ASCII just defines a 7 bit code page with 128 symbols. ANSI extends this to 8 bit and there are several different code pages for the symbols 128 to 255.

The naming ANSI is not correct because it is actually the ISO/IEC 8859 norm that defines this code pages. See ISO/IEC 8859 for reference. There are 16 code pages ISO/IEC 8859-1 to ISO/IEC 8859-16.

Windows-1252 is again based on ISO/IEC 8859-1 with some modification mainly in the range of the C1 control set in the range 128 to 159. Wikipedia states that Windows-1252 is also refered as ISO-8859-1 with a second hyphen between ISO and 8859. (Unbelievable! Who does something like that?!?)

How to get the current time in Python

Use:

>>> import datetime
>>> datetime.datetime.now()
datetime.datetime(2009, 1, 6, 15, 8, 24, 78915)

>>> print(datetime.datetime.now())
2009-01-06 15:08:24.789150

And just the time:

>>> datetime.datetime.now().time()
datetime.time(15, 8, 24, 78915)

>>> print(datetime.datetime.now().time())
15:08:24.789150

See the documentation for more information.

To save typing, you can import the datetime object from the datetime module:

>>> from datetime import datetime

Then remove the leading datetime. from all of the above.

Clicking a button within a form causes page refresh

You can try to prevent default handler:

html:

<button ng-click="saveUser($event)">

js:

$scope.saveUser = function (event) {
  event.preventDefault();
  // your code
}

Difference between UTF-8 and UTF-16?

Security: Use only UTF-8

Difference between UTF-8 and UTF-16? Why do we need these?

There have been at least a couple of security vulnerabilities in implementations of UTF-16. See Wikipedia for details.

WHATWG and W3C have now declared that only UTF-8 is to be used on the Web.

The [security] problems outlined here go away when exclusively using UTF-8, which is one of the many reasons that is now the mandatory encoding for all things.

Other groups are saying the same.

So while UTF-16 may continue being used internally by some systems such as Java and Windows, what little use of UTF-16 you may have seen in the past for data files, data exchange, and such, will likely fade away entirely.

How do I find the MySQL my.cnf location

For Ubuntu 16: /etc/mysql/mysql.conf.d/mysqld.cnf

Parsing JSON array into java.util.List with Gson

Below code is using com.google.gson.JsonArray. I have printed the number of element in list as well as the elements in List

import java.util.ArrayList;

import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;


public class Test {

    static String str = "{ "+ 
            "\"client\":\"127.0.0.1\"," + 
            "\"servers\":[" + 
            "    \"8.8.8.8\"," + 
            "    \"8.8.4.4\"," + 
            "    \"156.154.70.1\"," + 
            "    \"156.154.71.1\" " + 
            "    ]" + 
            "}";

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        try {

            JsonParser jsonParser = new JsonParser();
            JsonObject jo = (JsonObject)jsonParser.parse(str);
            JsonArray jsonArr = jo.getAsJsonArray("servers");
            //jsonArr.
            Gson googleJson = new Gson();
            ArrayList jsonObjList = googleJson.fromJson(jsonArr, ArrayList.class);
            System.out.println("List size is : "+jsonObjList.size());
                    System.out.println("List Elements are  : "+jsonObjList.toString());


        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}

OUTPUT

List size is : 4

List Elements are  : [8.8.8.8, 8.8.4.4, 156.154.70.1, 156.154.71.1]

What is the difference between 'java', 'javaw', and 'javaws'?

java.exe is associated with the console, whereas javaw.exe doesn't have any such association. So, when java.exe is run, it automatically opens a command prompt window where output and error streams are shown.

Convert a String to int?

So basically you want to convert a String into an Integer right! here is what I mostly use and that is also mentioned in official documentation..

fn main() {

    let char = "23";
    let char : i32 = char.trim().parse().unwrap();
    println!("{}", char + 1);

}

This works for both String and &str Hope this will help too.

Argument of type 'X' is not assignable to parameter of type 'X'

you just use variable type any and remove these types of problem.

error code :

  let accessToken = res;
  localStorage.setItem(LocalStorageConstants.TOKEN_KEY, accessToken);

given error Argument of type '{}' is not assignable to parameter of type 'string'.

success Code :

  var accessToken:any = res;
  localStorage.setItem(LocalStorageConstants.TOKEN_KEY, accessToken);

we create var type variable then use variable type any and resolve this issue.

any = handle any type of value so that remove error.

Pandas convert string to int

You need add parameter errors='coerce' to function to_numeric:

ID = pd.to_numeric(ID, errors='coerce')

If ID is column:

df.ID = pd.to_numeric(df.ID, errors='coerce')

but non numeric are converted to NaN, so all values are float.

For int need convert NaN to some value e.g. 0 and then cast to int:

df.ID = pd.to_numeric(df.ID, errors='coerce').fillna(0).astype(np.int64)

Sample:

df = pd.DataFrame({'ID':['4806105017087','4806105017087','CN414149']})
print (df)
              ID
0  4806105017087
1  4806105017087
2       CN414149

print (pd.to_numeric(df.ID, errors='coerce'))
0    4.806105e+12
1    4.806105e+12
2             NaN
Name: ID, dtype: float64

df.ID = pd.to_numeric(df.ID, errors='coerce').fillna(0).astype(np.int64)
print (df)
              ID
0  4806105017087
1  4806105017087
2              0

EDIT: If use pandas 0.25+ then is possible use integer_na:

df.ID = pd.to_numeric(df.ID, errors='coerce').astype('Int64')
print (df)
              ID
0  4806105017087
1  4806105017087
2            NaN

What are static factory methods?

The static factory method pattern is a way to encapsulate object creation. Without a factory method, you would simply call the class's constructor directly: Foo x = new Foo(). With this pattern, you would instead call the factory method: Foo x = Foo.create(). The constructors are marked private, so they cannot be called except from inside the class, and the factory method is marked as static so that it can be called without first having an object.

There are a few advantages to this pattern. One is that the factory can choose from many subclasses (or implementers of an interface) and return that. This way the caller can specify the behavior desired via parameters, without having to know or understand a potentially complex class hierarchy.

Another advantage is, as Matthew and James have pointed out, controlling access to a limited resource such as connections. This a way to implement pools of reusable objects - instead of building, using, and tearing down an object, if the construction and destruction are expensive processes it might make more sense to build them once and recycle them. The factory method can return an existing, unused instantiated object if it has one, or construct one if the object count is below some lower threshold, or throw an exception or return null if it's above the upper threshold.

As per the article on Wikipedia, multiple factory methods also allow different interpretations of similar argument types. Normally the constructor has the same name as the class, which means that you can only have one constructor with a given signature. Factories are not so constrained, which means you can have two different methods that accept the same argument types:

Coordinate c = Coordinate.createFromCartesian(double x, double y)

and

Coordinate c = Coordinate.createFromPolar(double distance, double angle)

This can also be used to improve readability, as Rasmus notes.

How can I create a blank/hardcoded column in a sql query?

For varchars, you may need to do something like this:

select convert(varchar(25), NULL) as abc_column into xyz_table

If you try

select '' as abc_column into xyz_table

you may get errors related to truncation, or an issue with null values, once you populate.

Using an HTML button to call a JavaScript function

I would say it would be better to add the javascript in an un-obtrusive manner...

if using jQuery you could do something like:

<script>
  $(document).ready(function(){
    $('#MyButton').click(function(){
       CapacityChart();
    });
  });
</script>

<input type="button" value="Capacity Chart" id="MyButton" >

How to iterate over a std::map full of strings in C++

iter->first and iter->second are variables, you are attempting to call them as methods.

How to bind list to dataGridView?

I know this is old, but this hung me up for awhile. The properties of the object in your list must be actual "properties", not just public members.

public class FileName
{        
     public string ThisFieldWorks {get;set;}
     public string ThisFieldDoesNot;
}

Explain the concept of a stack frame in a nutshell

A quick wrap up. Maybe someone has a better explanation.

A call stack is composed of 1 or many several stack frames. Each stack frame corresponds to a call to a function or procedure which has not yet terminated with a return.

To use a stack frame, a thread keeps two pointers, one is called the Stack Pointer (SP), and the other is called the Frame Pointer (FP). SP always points to the "top" of the stack, and FP always points to the "top" of the frame. Additionally, the thread also maintains a program counter (PC) which points to the next instruction to be executed.

The following are stored on the stack: local variables and temporaries, actual parameters of the current instruction (procedure, function, etc.)

There are different calling conventions regarding the cleaning of the stack.

Check if list is empty in C#

    If (list.Count==0){
      //you can show your error messages here
    } else {
      //here comes your datagridview databind 
    }

You can make your datagrid visible false and make it visible on the else section.

Getting the thread ID from a thread

To find the current thread Id use - `Thread.CurrentThread.ManagedThreadId'. But in this case you might need the current win32 thread id - use pInvoke to get it with this function:

[DllImport("Kernel32", EntryPoint = "GetCurrentThreadId", ExactSpelling = true)]
public static extern Int32 GetCurrentWin32ThreadId();

First you'll need to save the managed thread id and win32 thread id connection - use a dictionary that maps a win32 id to managed thread.

Then to find a thread by it's id iterate over the process's thread using Process.GetCurrentProcess().Threads and find the thread with that id:

foreach (ProcessThread thread in Process.GetCurrentProcess().Threads)
{
     var managedThread = win32ToManagedThread[thread.id];
     if((managedThread.ManagedThreadId == threadId)
     {
         return managedThread;
     }
}

How to handle static content in Spring MVC?

The Problem is with URLPattern

Change your URL pattern on your servlet mapping from "/" to "/*"

Error handling in C code

Use setjmp.

http://en.wikipedia.org/wiki/Setjmp.h

http://aszt.inf.elte.hu/~gsd/halado_cpp/ch02s03.html

http://www.di.unipi.it/~nids/docs/longjump_try_trow_catch.html

#include <setjmp.h>
#include <stdio.h>

jmp_buf x;

void f()
{
    longjmp(x,5); // throw 5;
}

int main()
{
    // output of this program is 5.

    int i = 0;

    if ( (i = setjmp(x)) == 0 )// try{
    {
        f();
    } // } --> end of try{
    else // catch(i){
    {
        switch( i )
        {
        case  1:
        case  2:
        default: fprintf( stdout, "error code = %d\n", i); break;
        }
    } // } --> end of catch(i){
    return 0;
}

#include <stdio.h>
#include <setjmp.h>

#define TRY do{ jmp_buf ex_buf__; if( !setjmp(ex_buf__) ){
#define CATCH } else {
#define ETRY } }while(0)
#define THROW longjmp(ex_buf__, 1)

int
main(int argc, char** argv)
{
   TRY
   {
      printf("In Try Statement\n");
      THROW;
      printf("I do not appear\n");
   }
   CATCH
   {
      printf("Got Exception!\n");
   }
   ETRY;

   return 0;
}

"element.dispatchEvent is not a function" js error caught in firebug of FF3.0

check for this by calling the library jquery after the noconflict.js or that this calling more than once jquery library after the noconflict.js

Common xlabel/ylabel for matplotlib subplots

I ran into a similar problem while plotting a grid of graphs. The graphs consisted of two parts (top and bottom). The y-label was supposed to be centered over both parts.

I did not want to use a solution that depends on knowing the position in the outer figure (like fig.text()), so I manipulated the y-position of the set_ylabel() function. It is usually 0.5, the middle of the plot it is added to. As the padding between the parts (hspace) in my code was zero, I could calculate the middle of the two parts relative to the upper part.

import matplotlib.pyplot as plt
import matplotlib.gridspec as gridspec

# Create outer and inner grid
outerGrid = gridspec.GridSpec(2, 3, width_ratios=[1,1,1], height_ratios=[1,1])
somePlot = gridspec.GridSpecFromSubplotSpec(2, 1,
               subplot_spec=outerGrid[3], height_ratios=[1,3], hspace = 0)

# Add two partial plots
partA = plt.subplot(somePlot[0])
partB = plt.subplot(somePlot[1])

# No x-ticks for the upper plot
plt.setp(partA.get_xticklabels(), visible=False)

# The center is (height(top)-height(bottom))/(2*height(top))
# Simplified to 0.5 - height(bottom)/(2*height(top))
mid = 0.5-somePlot.get_height_ratios()[1]/(2.*somePlot.get_height_ratios()[0])
# Place the y-label
partA.set_ylabel('shared label', y = mid)

plt.show()

picture

Downsides:

  • The horizontal distance to the plot is based on the top part, the bottom ticks might extend into the label.

  • The formula does not take space between the parts into account.

  • Throws an exception when the height of the top part is 0.

There is probably a general solution that takes padding between figures into account.