Programs & Examples On #Dynamic pivot

The PIVOT syntax converts row data into columnar data. A dynamic PIVOT is needed when there are an unknown number of row values that need to be converted to columns.

Download data url file

If you also want to give a suggested name to the file (instead of the default 'download') you can use the following in Chrome, Firefox and some IE versions:

function downloadURI(uri, name) {
  var link = document.createElement("a");
  link.download = name;
  link.href = uri;
  document.body.appendChild(link);
  link.click();
  document.body.removeChild(link);
  delete link;
}

And the following example shows it's use:

downloadURI("data:text/html,HelloWorld!", "helloWorld.txt");

How to trigger a click on a link using jQuery

With the code you provided, you cannot expect anything to happen. I second @mashappslabs : first add an event handler :

$("selector").click(function() {
    console.log("element was clicked"); // or alert("click");
});

then trigger your event :

$("selector").click(); //or
$("selector").trigger("click");

and you should see the message in your console.

How to initialize an array of custom objects

The simplest way to initialize an array

Create array

$array = @()

Create your header

$line = "" | select name,age,phone

Fill the line

$line.name = "Leandro"
$line.age = "39"
$line.phone = "555-555555"

Add line to $array

$array += $line

Result

$array

name                                                     age                                                      phone
----                                                     ---                                                      -----
Leandro                                                  39                                                       555-555555

scp or sftp copy multiple files with single command

NOTE: I apologize in advance for answering only a portion of the above question. However, I found these commands to be useful for my current unix needs.

Uploading specific files from a local machine to a remote machine:

~/Desktop/dump_files$ scp file1.txt file2.txt lab1.cpp etc.ext [email protected]:Folder1/DestinationFolderForFiles/

Uploading an entire directory from a local machine to a remote machine:

~$ scp -r Desktop/dump_files [email protected]:Folder1/DestinationFolderForFiles/

Downloading an entire directory from a remote machine to a local machine:

~/Desktop$ scp -r [email protected]:Public/web/ Desktop/

find vs find_by vs where

Suppose I have a model User

  1. User.find(id)

Returns a row where primary key = id. The return type will be User object.

  1. User.find_by(email:"[email protected]")

Returns first row with matching attribute or email in this case. Return type will be User object again.

Note :- User.find_by(email: "[email protected]") is similar to User.find_by_email("[email protected]")

  1. User.where(project_id:1)

Returns all users in users table where attribute matches.

Here return type will be ActiveRecord::Relation object. ActiveRecord::Relation class includes Ruby's Enumerable module so you can use it's object like an array and traverse on it.

Sort ObservableCollection<string> through C#

I looked at these, I was getting it sorted, and then it broke the binding, as above. Came up with this solution, though simpler than most of yours, it appears to do what I want to,,,

public static ObservableCollection<string> OrderThoseGroups( ObservableCollection<string> orderThoseGroups)
    {
        ObservableCollection<string> temp;
        temp =  new ObservableCollection<string>(orderThoseGroups.OrderBy(p => p));
        orderThoseGroups.Clear();
        foreach (string j in temp) orderThoseGroups.Add(j);
        return orderThoseGroups;



    }

How to compile a c++ program in Linux?

  1. To Compile your C++ code use:-

g++ file_name.cpp -o executable_file_name

(i) -o option is used to show error in the code (ii) if there is no error in the code_file, then it will generate an executable file.

  1. Now execute the generated executable file:

./executable_file_name

android layout with visibility GONE

Kotlin Style way to do this more simple (example):

    isVisible = false

Complete example:

    if (some_data_array.details == null){
                holder.view.some_data_array.isVisible = false}

What is the simplest and most robust way to get the user's current location on Android?

EDIT: Updated with the latest Location Service API from Google Play Services library (July 2014)

I would recommend you to use the new Location Service API, available from the Google Play Services library, which provides a more powerful, high-level framework that automates tasks such as location provider choice and power management. According to the official documentation: "... Location API make it easy for you to build location-aware applications, without needing to focus on the details of the underlying location technology. They also let you minimize power consumption by using all of the capabilities of the device hardware."

For further information visit: Making Your App Location-Aware

To see a full example using the latest Location Service API visit: Android LocationClient class is deprecated but used in documentation

Error "There is already an open DataReader associated with this Command which must be closed first" when using 2 distinct commands

I bet the problem is being shown in this line

SqlDataReader dr3 = com2.ExecuteReader();

I suggest that you execute the first reader and do a dr.Close(); and the iterate historicos, with another loop, performing the com2.ExecuteReader().

public List<string[]> get_dados_historico_verificacao_email_WEB(string email)
    {

        List<string[]> historicos = new List<string[]>();
        conecta();
        sql = "SELECT * FROM historico_verificacao_email WHERE nm_email = '" + email + "' ORDER BY  dt_verificacao_email DESC, hr_verificacao_email DESC"; 
        com = new SqlCommand(sql, conexao);
        SqlDataReader dr = com.ExecuteReader();

        if (dr.HasRows)
        {
            while (dr.Read())
            {
                string[] dados_historico = new string[6];
                dados_historico[0] = dr["nm_email"].ToString();
                dados_historico[1] = dr["dt_verificacao_email"].ToString();
                dados_historico[1] = dados_historico[1].Substring(0, 10);
                //System.Windows.Forms.MessageBox.Show(dados_historico[1]);
                dados_historico[2] = dr["hr_verificacao_email"].ToString();
                dados_historico[3] = dr["ds_tipo_verificacao"].ToString();
                dados_historico[5] = dr["cd_login_usuario"].ToString();
                historicos.Add(dados_historico);
            }

            dr.Close();

            sql = "SELECT COUNT(e.cd_historico_verificacao_email) QT FROM emails_lidos e WHERE e.cd_historico_verificacao_email = '" + dr["cd_historico_verificacao_email"].ToString() + "'";
            tipo_sql = "seleção";
            com2 = new SqlCommand(sql, conexao);

            for(int i = 0 ; i < historicos.Count() ; i++)
            {
                SqlDataReader dr3 = com2.ExecuteReader();
                while (dr3.Read())
                {
                    historicos[i][4] = dr3["QT"].ToString(); //quantidade de emails lidos naquela verificação
                }
                dr3.Close();
            }

        }

        return historicos;

Insert into ... values ( SELECT ... FROM ... )

Just use parenthesis for SELECT clause into INSERT. For example like this :

INSERT INTO Table1 (col1, col2, your_desired_value_from_select_clause, col3)
VALUES (
   'col1_value', 
   'col2_value',
   (SELECT col_Table2 FROM Table2 WHERE IdTable2 = 'your_satisfied_value_for_col_Table2_selected'),
   'col3_value'
);

How to call Android contacts list?

I do it this way for Android 2.2 Froyo release: basically use eclipse to create a class like: public class SomePickContactName extends Activity

then insert this code. Remember to add the private class variables and CONSTANTS referenced in my version of the code:

protected void onCreate(Bundle savedInstanceState) 
{
  super.onCreate(savedInstanceState);       
  Intent intentContact = new Intent(Intent.ACTION_PICK, ContactsContract.Contacts.CONTENT_URI); 
  startActivityForResult(intentContact, PICK_CONTACT);
}//onCreate

public void onActivityResult(int requestCode, int resultCode, Intent intent) 
{

  if (requestCode == PICK_CONTACT)
  {         
    getContactInfo(intent);         
    // Your class variables now have the data, so do something with it. 
  }
}//onActivityResult

protected void getContactInfo(Intent intent)
{

   Cursor cursor =  managedQuery(intent.getData(), null, null, null, null);      
   while (cursor.moveToNext()) 
   {           
       String contactId = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts._ID));
       name = cursor.getString(cursor.getColumnIndexOrThrow(ContactsContract.Contacts.DISPLAY_NAME)); 

       String hasPhone = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER));

       if ( hasPhone.equalsIgnoreCase("1"))
           hasPhone = "true";
       else
           hasPhone = "false" ;

       if (Boolean.parseBoolean(hasPhone)) 
       {
        Cursor phones = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,ContactsContract.CommonDataKinds.Phone.CONTACT_ID +" = "+ contactId,null, null);
        while (phones.moveToNext()) 
        {
          phoneNumber = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
        }
        phones.close();
       }

       // Find Email Addresses
       Cursor emails = getContentResolver().query(ContactsContract.CommonDataKinds.Email.CONTENT_URI,null,ContactsContract.CommonDataKinds.Email.CONTACT_ID + " = " + contactId,null, null);
       while (emails.moveToNext()) 
       {
        emailAddress = emails.getString(emails.getColumnIndex(ContactsContract.CommonDataKinds.Email.DATA));
       }
       emails.close();

    Cursor address = getContentResolver().query(
                ContactsContract.CommonDataKinds.StructuredPostal.CONTENT_URI,
                null,
                ContactsContract.CommonDataKinds.StructuredPostal.CONTACT_ID + " = " + contactId,
                null, null);
    while (address.moveToNext()) 
    { 
      // These are all private class variables, don't forget to create them.
      poBox      = address.getString(address.getColumnIndex(ContactsContract.CommonDataKinds.StructuredPostal.POBOX));
      street     = address.getString(address.getColumnIndex(ContactsContract.CommonDataKinds.StructuredPostal.STREET));
      city       = address.getString(address.getColumnIndex(ContactsContract.CommonDataKinds.StructuredPostal.CITY));
      state      = address.getString(address.getColumnIndex(ContactsContract.CommonDataKinds.StructuredPostal.REGION));
      postalCode = address.getString(address.getColumnIndex(ContactsContract.CommonDataKinds.StructuredPostal.POSTCODE));
      country    = address.getString(address.getColumnIndex(ContactsContract.CommonDataKinds.StructuredPostal.COUNTRY));
      type       = address.getString(address.getColumnIndex(ContactsContract.CommonDataKinds.StructuredPostal.TYPE));
    }  //address.moveToNext()   
  }  //while (cursor.moveToNext())        
   cursor.close();
}//getContactInfo

Retrieving the COM class factory for component failed

I had the same error when I deployed my app. I've got solution from this site: Component with CLSID XXX failed due to the following error: 80070005 Access is denied

Here is this solution:

  1. In DCOMCNFG, right click on the My Computer and select properties.

  2. Choose the COM Securities tab.

  3. In Access Permissions, click Edit Defaults and add Network Service to it and give it Allow local access permission. Do the same for < Machine_name >\Users.

  4. In Launch and Activation Permissions, click Edit Defaults and add Network Service to it and give it Local launch and Local Activation permission. Do the same for < Machine_name >\Users.

*I used forms authentication.

mysqli or PDO - what are the pros and cons?

In my benchmark script, each method is tested 10000 times and the difference of the total time for each method is printed. You should this on your own configuration, I'm sure results will vary!

These are my results:

  • "SELECT NULL" -> PGO() faster by ~ 0.35 seconds
  • "SHOW TABLE STATUS" -> mysqli() faster by ~ 2.3 seconds
  • "SELECT * FROM users" -> mysqli() faster by ~ 33 seconds

Note: by using ->fetch_row() for mysqli, the column names are not added to the array, I didn't find a way to do that in PGO. But even if I use ->fetch_array() , mysqli is slightly slower but still faster than PGO (except for SELECT NULL).

How do I get the directory of the PowerShell script I execute?

PowerShell 3 has the $PSScriptRoot automatic variable:

Contains the directory from which a script is being run.

In Windows PowerShell 2.0, this variable is valid only in script modules (.psm1). Beginning in Windows PowerShell 3.0, it is valid in all scripts.

Don't be fooled by the poor wording. PSScriptRoot is the directory of the current file.

In PowerShell 2, you can calculate the value of $PSScriptRoot yourself:

# PowerShell v2
$PSScriptRoot = Split-Path -Parent -Path $MyInvocation.MyCommand.Definition

Unable to find the wrapper "https" - did you forget to enable it when you configured PHP?

In my case, the issue was due to WAMP using a different php.ini for CLI than Apache, so your settings made through the WAMP menu don't apply to CLI. Just modify the CLI php.ini and it works.

Setting width as a percentage using jQuery

Using the width function:

$('div#somediv').width('70%');

will turn:

<div id="somediv" />

into:

<div id="somediv" style="width: 70%;"/>

Reading binary file and looping over each byte

Python 3, read all of the file at once:

with open("filename", "rb") as binary_file:
    # Read the whole file at once
    data = binary_file.read()
    print(data)

You can iterate whatever you want using data variable.

How can I retrieve Id of inserted entity using Entity framework?

There are two strategies:

  1. Use Database-generated ID (int or GUID)

    Cons:

    You should perform SaveChanges() to get the ID for just saved entities.

    Pros:

    Can use int identity.

  2. Use client generated ID - GUID only.

    Pros: Minification of SaveChanges operations. Able to insert a big graph of new objects per one operation.

    Cons:

    Allowed only for GUID

Using regular expressions to do mass replace in Notepad++ and Vim

Notepad ++ : Search Mode = Regular expression

Find what: (.*>)(.)

Replace with: \2

Use a.empty, a.bool(), a.item(), a.any() or a.all()

As user2357112 mentioned in the comments, you cannot use chained comparisons here. For elementwise comparison you need to use &. That also requires using parentheses so that & wouldn't take precedence.

It would go something like this:

mask = ((50  < df['heart rate']) & (101 > df['heart rate']) & (140 < df['systolic...

In order to avoid that, you can build series for lower and upper limits:

low_limit = pd.Series([90, 50, 95, 11, 140, 35], index=df.columns)
high_limit = pd.Series([160, 101, 100, 19, 160, 39], index=df.columns)

Now you can slice it as follows:

mask = ((df < high_limit) & (df > low_limit)).all(axis=1)
df[mask]
Out: 
     dyastolic blood pressure  heart rate  pulse oximetry  respiratory rate  \
17                        136          62              97                15   
69                        110          85              96                18   
72                        105          85              97                16   
161                       126          57              99                16   
286                       127          84              99                12   
435                        92          67              96                13   
499                       110          66              97                15   

     systolic blood pressure  temperature  
17                       141           37  
69                       155           38  
72                       154           36  
161                      153           36  
286                      156           37  
435                      155           36  
499                      149           36  

And for assignment you can use np.where:

df['class'] = np.where(mask, 'excellent', 'critical')

ComboBox.SelectedText doesn't give me the SelectedText

All of the previous answers explain what the OP 'should' do. I am explaining what the .SelectedText property is.

The .SelectedText property is not the text in the combobox. It is the text that is highlighted. It is the same as .SelectedText property for a textbox.

The following picture shows that the .SelectedText property would be equal to "ort".

enter image description here

Convert blob URL to normal URL

Found this answer here and wanted to reference it as it appear much cleaner than the accepted answer:

function blobToDataURL(blob, callback) {
  var fileReader = new FileReader();
  fileReader.onload = function(e) {callback(e.target.result);}
  fileReader.readAsDataURL(blob);
}

Current date without time

If you need exact your example, you should add format to ToString()

    string test = DateTime.ParseExact(DateTime.Now.ToString("dd.MM.yyyy"), "dd.MM.yyyy", CultureInfo.InvariantCulture).ToString("yyyy-MM-dd");

But it's better to use straight formatting:

    string test = DateTime.Now.ToString("yyyy-MM-dd")

How to add a margin to a table row <tr>

Another possibility is to use a pseudo selector :after or :before

tr.highlight td:last-child:after
{
  content: "\0a0";
  line-height: 3em;
}

That might avoid issues with browser that don't understand the pseudo selectors, plus background-colors are not an issue.

The downside is however, that it adds some extra whitespace after the last cell.

ORA-00060: deadlock detected while waiting for resource

I ran into this issue as well. I don't know the technical details of what was actually happening. However, in my situation, the root cause was that there was cascading deletes setup in the Oracle database and my JPA/Hibernate code was also trying to do the cascading delete calls. So my advice is to make sure that you know exactly what is happening.

Execute a command in command prompt using excel VBA

The S parameter does not do anything on its own.

/S      Modifies the treatment of string after /C or /K (see below) 
/C      Carries out the command specified by string and then terminates  
/K      Carries out the command specified by string but remains  

Try something like this instead

Call Shell("cmd.exe /S /K" & "perl a.pl c:\temp", vbNormalFocus)

You may not even need to add "cmd.exe" to this command unless you want a command window to open up when this is run. Shell should execute the command on its own.

Shell("perl a.pl c:\temp")



-Edit-
To wait for the command to finish you will have to do something like @Nate Hekman shows in his answer here

Dim wsh As Object
Set wsh = VBA.CreateObject("WScript.Shell")
Dim waitOnReturn As Boolean: waitOnReturn = True
Dim windowStyle As Integer: windowStyle = 1

wsh.Run "cmd.exe /S /C perl a.pl c:\temp", windowStyle, waitOnReturn

How to change DatePicker dialog color for Android 5.0

try this, work for me

Put the two options, colorAccent and android:colorAccent

<style name="AppTheme" parent="@style/Theme.AppCompat.Light.NoActionBar">
    <!-- Customize your theme here. -->
   ....
    <item name="android:dialogTheme">@style/AppTheme.DialogTheme</item>
    <item name="android:datePickerDialogTheme">@style/Dialog.Theme</item>
</style>

<style name="AppTheme.DialogTheme" parent="Theme.AppCompat.Light.Dialog">

<!-- Put the two options, colorAccent and android:colorAccent. -->
    <item name="colorAccent">@color/colorPrimary</item>
    <item name="android:colorPrimary">@color/colorPrimary</item>
    <item name="android:colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="android:colorAccent">@color/colorPrimary</item>
 </style>

Can HTML checkboxes be set to readonly?

Latest jQuery has this feature

$("#txtname").prop('readonly', false);

Returning JSON from PHP to JavaScript?

Here are a couple of things missing in the previous answers:

  1. Set header in your PHP:

    header('Content-type: application/json');
    echo json_encode($array);
    
  2. json_encode() can return a JavaScript array instead of JavaScript object, see:
    Returning JSON from a PHP Script
    This could be important to know in some cases as arrays and objects are not the same.

define() vs. const

Most of these answers are wrong or are only telling half the story.

  1. You can scope your constants by using namespaces.
  2. You can use the "const" keyword outside of class definitions. However, just like in classes the values assigned using the "const" keyword must be constant expressions.

For example:

const AWESOME = 'Bob'; // Valid

Bad example:

const AWESOME = whatIsMyName(); // Invalid (Function call)
const WEAKNESS = 4+5+6; // Invalid (Arithmetic) 
const FOO = BAR . OF . SOAP; // Invalid (Concatenation)

To create variable constants use define() like so:

define('AWESOME', whatIsMyName()); // Valid
define('WEAKNESS', 4 + 5 + 6); // Valid
define('FOO', BAR . OF . SOAP); // Valid

Checking whether a String contains a number value in Java

Shef's answer doesn't compile for me. It looks like he's using RegEx in String.contains(). If you want to use RegEx use this:

String strWithNumber = "This string has a 1 number";
String strWithoutNumber = "This string has a number";

System.out.println(strWithNumber.matches(".*\\d.*"));
System.out.println(strWithoutNumber.matches(".*\\d.*"));

Does IMDB provide an API?

Yes, but not for free.

.....annual fees ranging from $15,000 to higher depending on the audience for the data and which data are being licensed.

URL :- http://www.imdb.com/licensing/

Force Intellij IDEA to reread all maven dependencies

To remove all dependencies you can simply delete your local maven repo: ~/.m2 folder by default. Then rebuild your projects one-by-one:

mvn clean
mvn package

How to view UTF-8 Characters in VIM or Gvim

On Microsoft Windows, gvim wouldn't allow you to select non-monospaced fonts. Unfortunately Latha is a non-monospaced font.

There is a hack way to make it happen: Using FontForge (you can download Windows binary from http://www.geocities.jp/meir000/fontforge/) to edit the Latha.ttf and mark it as a monospaced font. Doing like this:

  1. Load fontforge, select latha.ttf.
  2. Menu: Element -> Font Info
  3. Select "OS/2" from left-hand list on Font Info dialog
  4. Select "Panose" tab
  5. Set Proportion = Monospaced
  6. Save new TTF version of this font, try it out!

Good luck!

How can I obtain the element-wise logical NOT of a pandas Series?

NumPy is slower because it casts the input to boolean values (so None and 0 becomes False and everything else becomes True).

import pandas as pd
import numpy as np
s = pd.Series([True, None, False, True])
np.logical_not(s)

gives you

0    False
1     True
2     True
3    False
dtype: object

whereas ~s would crash. In most cases tilde would be a safer choice than NumPy.

Pandas 0.25, NumPy 1.17

Extract every nth element of a vector

a <- 1:120
b <- a[seq(1, length(a), 6)]

Connect to external server by using phpMyAdmin

To set up an external DB and still use your local DB, you need to edit the config.inc.php file:

On Ubuntu: sudo gedit /etc/phpmyadmin/config.inc.php

The file is roughly set up like this:

if (!empty($dbname)) {

    //Your local db setup

     $i++;
}

What you need to do is duplicate the "your local db setup" by copying and pasting it outside of the IF statement I've shown in the code below, and change the host to you external IP. Mine for example is:

$cfg['Servers'][$i]['host'] = '10.10.1.90:23306';

You can leave the defaults (unless you know you need to change them)

Save and refresh your PHPMYADMIN login page and a new dropdown should appear. You should be good to go.


EDIT: if you want to give the server a name to select at login page, rather than having just the IP address to select, add this to the server setup:

$cfg['Servers'][$i]['verbose'] = 'Name to show when selecting your server'; 

It's good if you have multiple server configs.

How to set Internet options for Android emulator?

On a slightly different note, I had to make a virtual device without GSM Modem Support so that the internet on my emulator would work.

How to find the foreach index?

You can create $i outside the loop and do $i++ at the bottom of the loop.

Drop multiple tables in one shot in MySQL

Example:

Let's say table A has two children B and C. Then we can use the following syntax to drop all tables.

DROP TABLE IF EXISTS B,C,A;

This can be placed in the beginning of the script instead of individually dropping each table.

How to draw interactive Polyline on route google maps v2 android

You should use options.addAll(allPoints); instead of options.add(point);

Using an array from Observable Object with ngFor and Async Pipe Angular 2

Here's an example

// in the service
getVehicles(){
    return Observable.interval(2200).map(i=> [{name: 'car 1'},{name: 'car 2'}])
}

// in the controller
vehicles: Observable<Array<any>>
ngOnInit() {
    this.vehicles = this._vehicleService.getVehicles();
}

// in template
<div *ngFor='let vehicle of vehicles | async'>
    {{vehicle.name}}
</div>

How to align a div to the top of its parent but keeping its inline-block behaviour?

As others have said, vertical-align: top is your friend.

As a bonus here is a forked fiddle with added enhancements that make it work in Internet Explorer 6 and Internet Explorer 7 too ;)

Example: here

Rename all files in a folder with a prefix in a single command

With rnm (you will need to install it):

rnm -ns 'Unix_/fn/' *

Or

rnm -rs '/^/Unix_/' *

P.S : I am the author of this tool.

Extract public/private key from PKCS12 file for later use in SSH-PK-Authentication

The accepted answer is the correct command, I just want to add one additional thing, when extracting the key if you leave the PEM password("Enter PEM pass phrase:") blank then the complete key will not be extracted but only the localKeyID will be extracted. To get the complete key you must specify a PEM password whem running the following command.

Please note that when it comes to Import password, you can specify the actual password for "Enter Import Password:" or can leave this password blank:

openssl pkcs12 -in yourP12File.pfx -nocerts -out privateKey.pem

Git push/clone to new server

There are many ways to move repositories around, git bundle is a nice way if you have insufficient network availability. Since a Git repository is really just a directory full of files, you can "clone" a repository by making a copy of the .git directory in whatever way suits you best.

The most efficient way is to use an external repository somewhere (use GitHub or set up Gitosis), and then git push.

How can I remove an element from a list?

There's the rlist package (http://cran.r-project.org/web/packages/rlist/index.html) to deal with various kinds of list operations.

Example (http://cran.r-project.org/web/packages/rlist/vignettes/Filtering.html):

library(rlist)
devs <- 
  list(
    p1=list(name="Ken",age=24,
      interest=c("reading","music","movies"),
      lang=list(r=2,csharp=4,python=3)),
    p2=list(name="James",age=25,
      interest=c("sports","music"),
      lang=list(r=3,java=2,cpp=5)),
    p3=list(name="Penny",age=24,
      interest=c("movies","reading"),
      lang=list(r=1,cpp=4,python=2)))

list.remove(devs, c("p1","p2"))

Results in:

# $p3
# $p3$name
# [1] "Penny"
# 
# $p3$age
# [1] 24
# 
# $p3$interest
# [1] "movies"  "reading"
# 
# $p3$lang
# $p3$lang$r
# [1] 1
# 
# $p3$lang$cpp
# [1] 4
# 
# $p3$lang$python
# [1] 2

Automatic HTTPS connection/redirect with node.js/express

Thanks to this guy: https://www.tonyerwin.com/2014/09/redirecting-http-to-https-with-nodejs.html

app.use (function (req, res, next) {
        if (req.secure) {
                // request was via https, so do no special handling
                next();
        } else {
                // request was via http, so redirect to https
                res.redirect('https://' + req.headers.host + req.url);
        }
});

Char array in a struct - incompatible assignment?

You can also initialise it like this:

struct name sara = { "Sara", "Black" };

Since (as a special case) you're allowed to initialise char arrays from string constants.

Now, as for what a struct actually is - it's a compound type composed of other values. What sara actually looks like in memory is a block of 20 consecutive char values (which can be referred to using sara.first, followed by 0 or more padding bytes, followed by another block of 20 consecutive char values (which can be referred to using sara.last). All other instances of the struct name type are laid out in the same way.

In this case, it is very unlikely that there is any padding, so a struct name is just a block of 40 characters, for which you have a name for the first 20 and the last 20.

You can find out how big a block of memory a struct name takes using sizeof(struct name), and you can find out where within that block of memory each member of the structure is placed at using offsetof(struct name, first) and offsetof(struct name, last).

Full examples of using pySerial package

http://web.archive.org/web/20131107050923/http://www.roman10.net/serial-port-communication-in-python/comment-page-1/

#!/usr/bin/python

import serial, time
#initialization and open the port

#possible timeout values:
#    1. None: wait forever, block call
#    2. 0: non-blocking mode, return immediately
#    3. x, x is bigger than 0, float allowed, timeout block call

ser = serial.Serial()
#ser.port = "/dev/ttyUSB0"
ser.port = "/dev/ttyUSB7"
#ser.port = "/dev/ttyS2"
ser.baudrate = 9600
ser.bytesize = serial.EIGHTBITS #number of bits per bytes
ser.parity = serial.PARITY_NONE #set parity check: no parity
ser.stopbits = serial.STOPBITS_ONE #number of stop bits
#ser.timeout = None          #block read
ser.timeout = 1            #non-block read
#ser.timeout = 2              #timeout block read
ser.xonxoff = False     #disable software flow control
ser.rtscts = False     #disable hardware (RTS/CTS) flow control
ser.dsrdtr = False       #disable hardware (DSR/DTR) flow control
ser.writeTimeout = 2     #timeout for write

try: 
    ser.open()
except Exception, e:
    print "error open serial port: " + str(e)
    exit()

if ser.isOpen():

    try:
        ser.flushInput() #flush input buffer, discarding all its contents
        ser.flushOutput()#flush output buffer, aborting current output 
                 #and discard all that is in buffer

        #write data
        ser.write("AT+CSQ")
        print("write data: AT+CSQ")

       time.sleep(0.5)  #give the serial port sometime to receive the data

       numOfLines = 0

       while True:
          response = ser.readline()
          print("read data: " + response)

        numOfLines = numOfLines + 1

        if (numOfLines >= 5):
            break

        ser.close()
    except Exception, e1:
        print "error communicating...: " + str(e1)

else:
    print "cannot open serial port "

openssl s_client using a proxy

You can use proxytunnel:

proxytunnel -p yourproxy:8080 -d www.google.com:443 -a 7000

and then you can do this:

openssl s_client -connect localhost:7000 -showcerts

Hope this can help you!

Installing tkinter on ubuntu 14.04

If you're using Python 3 then you must install as follows:

sudo apt-get update
sudo apt-get install python3-tk

Tkinter for Python 2 (python-tk) is different from Python 3's (python3-tk).

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

The following code simulates an array ('params') - takes the parameters received by the script and stores them in the variables params_1 .. params_n, where n=params_0=the number of elements of the array:

@echo off

rem Storing the program parameters into the array 'params':
rem Delayed expansion is left disabled in order not to interpret "!" in program parameters' values;
rem however, if a parameter is not quoted, special characters in it (like "^", "&", "|") get interpreted at program launch
set /a count=0
:repeat
    set /a count+=1
    set "params_%count%=%~1"
    shift
    if defined params_%count% (
        goto :repeat
    ) else (
        set /a count-=1
    )    
set /a params_0=count

rem Printing the program parameters stored in the array 'params':
rem After the variables params_1 .. params_n are set with the program parameters' values, delayed expansion can
rem be enabled and "!" are not interpreted in the variables params_1 .. params_n values
setlocal enabledelayedexpansion
    for /l %%i in (1,1,!params_0!) do (
        echo params_%%i: "!params_%%i!"
    )
endlocal

pause
goto :eof

How to convert String to Date value in SAS?

This code helps:

data final; set final;

first_date = INPUT(compress(char_date),date9.); format first_date date9.;

run;

I personally have tried it on SAS

Select element based on multiple classes

You can use these solutions :

CSS rules applies to all tags that have following two classes :

.left.ui-class-selector {
    /*style here*/
}

CSS rules applies to all tags that have <li> with following two classes :

li.left.ui-class-selector {
   /*style here*/
}

jQuery solution :

$("li.left.ui-class-selector").css("color", "red");

Javascript solution :

document.querySelector("li.left.ui-class-selector").style.color = "red";

Progress during large file copy (Copy-Item & Write-Progress?)

Hate to be the one to bump an old subject, but I found this post extremely useful. After running performance tests on the snippets by stej and it's refinement by Graham Gold, plus the BITS suggestion by Nacht, I have decuded that:

  1. I really liked Graham's command with time estimations and speed readings.
  2. I also really liked the significant speed increase of using BITS as my transfer method.

Faced with the decision between the two... I found that Start-BitsTransfer supported Asynchronous mode. So here is the result of my merging the two.

function Copy-File {
    # ref: https://stackoverflow.com/a/55527732/3626361
    param([string]$From, [string]$To)

    try {
        $job = Start-BitsTransfer -Source $From -Destination $To `
            -Description "Moving: $From => $To" `
            -DisplayName "Backup" -Asynchronous

        # Start stopwatch
        $sw = [System.Diagnostics.Stopwatch]::StartNew()
        Write-Progress -Activity "Connecting..."

        while ($job.JobState.ToString() -ne "Transferred") {
            switch ($job.JobState.ToString()) {
                "Connecting" {
                    break
                }
                "Transferring" {
                    $pctcomp = ($job.BytesTransferred / $job.BytesTotal) * 100
                    $elapsed = ($sw.elapsedmilliseconds.ToString()) / 1000

                    if ($elapsed -eq 0) {
                        $xferrate = 0.0
                    }
                    else {
                        $xferrate = (($job.BytesTransferred / $elapsed) / 1mb);
                    }

                    if ($job.BytesTransferred % 1mb -eq 0) {
                        if ($pctcomp -gt 0) {
                            $secsleft = ((($elapsed / $pctcomp) * 100) - $elapsed)
                        }
                        else {
                            $secsleft = 0
                        }

                        Write-Progress -Activity ("Copying file '" + ($From.Split("\") | Select-Object -last 1) + "' @ " + "{0:n2}" -f $xferrate + "MB/s") `
                            -PercentComplete $pctcomp `
                            -SecondsRemaining $secsleft
                    }
                    break
                }
                "Transferred" {
                    break
                }
                Default {
                    throw $job.JobState.ToString() + " unexpected BITS state."
                }
            }
        }

        $sw.Stop()
        $sw.Reset()
    }
    finally {
        Complete-BitsTransfer -BitsJob $job
        Write-Progress -Activity "Completed" -Completed
    }
}

Attach event to dynamic elements in javascript

The difference is in how you create and append elements in the DOM.

If you create an element via document.createElement, add an event listener, and append it to the DOM. Your events will fire.

If you create an element as a string like this: html += "<li>test</li>"`, the elment is technically just a string. Strings cannot have event listeners.

One solution is to create each element with document.createElement and then add those to a DOM element directly.

// Sample
let li = document.createElement('li')
document.querySelector('ul').appendChild(li)

Rewrite all requests to index.php with nginx

To pass get variables as well use $args:

location / {
    try_files $uri $uri/ /index.php?$args;
}

What's the fastest way to delete a large folder in Windows?

use fastcopy, a free tool. it has a delete option that is a lot faster then the way windows deletes files.

server error:405 - HTTP verb used to access this page is not allowed

I've been pulling my hair out over this one for a couple of hours also. fakeartist appears correct though - I changed the file extension from .htm to .php and I can now see my page in Facebook! It also works if you change the extension to .aspx - perhaps it just needs to be a server side extension (I've not tried with .jsp).

Finding the index of an item in a list

a = ["foo","bar","baz",'bar','any','much']

indexes = [index for index in range(len(a)) if a[index] == 'bar']

HTTP Status 405 - Method Not Allowed Error for Rest API

In above code variable "ver" is assign to null, print "ver" before returning and see the value. As this "ver" having null service is send status as "204 No Content".

And about status code "405 - Method Not Allowed" will get this status code when rest controller or service only supporting GET method but from client side your trying with POST with valid uri request, during such scenario get status as "405 - Method Not Allowed"

Environment variable in Jenkins Pipeline

To avoid problems of side effects after changing env, especially using multiple nodes, it is better to set a temporary context.

One safe way to alter the environment is:

 withEnv(['MYTOOL_HOME=/usr/local/mytool']) {
    sh '$MYTOOL_HOME/bin/start'
 }

This approach does not poison the env after the command execution.

Find a private field with Reflection?

Yes, however you will need to set your Binding flags to search for private fields (if your looking for the member outside of the class instance).

The binding flag you will need is: System.Reflection.BindingFlags.NonPublic

How to initialize/instantiate a custom UIView class with a XIB file in Swift

As of Swift 2.0, you can add a protocol extension. In my opinion, this is a better approach because the return type is Self rather than UIView, so the caller doesn't need to cast to the view class.

import UIKit

protocol UIViewLoading {}
extension UIView : UIViewLoading {}

extension UIViewLoading where Self : UIView {

  // note that this method returns an instance of type `Self`, rather than UIView
  static func loadFromNib() -> Self {
    let nibName = "\(self)".characters.split{$0 == "."}.map(String.init).last!
    let nib = UINib(nibName: nibName, bundle: nil)
    return nib.instantiateWithOwner(self, options: nil).first as! Self
  }

}

Add text at the end of each line

sed 's/.*/&:80/'  abcd.txt >abcde.txt

How do I make a transparent canvas in html5?

Can't comment the last answer but the fix is relatively easy. Just set the background color of your opaque canvas:

#canvas1 { background-color: black; } //opaque canvas
#canvas2 { ... } //transparent canvas

I'm not sure but it looks like that the background-color is inherited as transparent from the body.

Error:Failed to open zip file. Gradle's dependency cache may be corrupt

just remove and reDownload wrapper gradle.

Mac Home/.gradle/wrapper/dists/

remove gradle version and sync gradle in project and run project.

enter image description here

How to remove line breaks (no characters!) from the string?

You should be able to replace it with a preg that removes all newlines and carriage returns. The code is:

preg_replace( "/\r|\n/", "", $yourString );

Even though the \n characters are not appearing, if you are getting carriage returns there is an invisible character there. The preg replace should grab and fix those.

How can I trigger another job from a jenkins pipeline (jenkinsfile) with GitHub Org Plugin?

Use build job plugin for that task in order to trigger other jobs from jenkins file. You can add variety of logic to your execution such as parallel ,node and agents options and steps for triggering external jobs. I gave some easy-to-read cookbook example for that.

1.example for triggering external job from jenkins file with conditional example:

if (env.BRANCH_NAME == 'master') {
  build job:'exactJobName' , parameters:[
    string(name: 'keyNameOfParam1',value: 'valueOfParam1')
    booleanParam(name: 'keyNameOfParam2',value:'valueOfParam2')
 ]
}

2.example triggering multiple jobs from jenkins file with conditionals example:

 def jobs =[
    'job1Title'{
    if (env.BRANCH_NAME == 'master') {
      build job:'exactJobName' , parameters:[
        string(name: 'keyNameOfParam1',value: 'valueNameOfParam1')
        booleanParam(name: 'keyNameOfParam2',value:'valueNameOfParam2')
     ]
    }
},
    'job2Title'{
    if (env.GIT_COMMIT == 'someCommitHashToPerformAdditionalTest') {
      build job:'exactJobName' , parameters:[
        string(name: 'keyNameOfParam3',value: 'valueOfParam3')
        booleanParam(name: 'keyNameOfParam4',value:'valueNameOfParam4')
        booleanParam(name: 'keyNameOfParam5',value:'valueNameOfParam5')
     ]
    }
}

"for" vs "each" in Ruby

(1..4).each { |i| 


  a = 9 if i==3

  puts a 


}
#nil
#nil
#9
#nil

for i in 1..4

  a = 9 if i==3

  puts a

end
#nil
#nil
#9
#9

In 'for' loop, local variable is still lives after each loop. In 'each' loop, local variable refreshes after each loop.

Redirect with CodeIgniter

If your directory structure is like this,

site
  application
         controller
                folder_1
                   first_controller.php
                   second_controller.php
                folder_2
                   first_controller.php
                   second_controller.php

And when you are going to redirect it in same controller in which you are working then just write the following code.

 $this->load->helper('url');
    if ($some_value === FALSE/TRUE) //You may give 0/1 as well,its up to your logic
    {
         redirect('same_controller/method', 'refresh');
    }

And if you want to redirect to another control then use the following code.

$this->load->helper('url');
if ($some_value === FALSE/TRUE) //You may give 0/1 as well,its up to your logic
{
     redirect('folder_name/any_controller_name/method', 'refresh');
}

Run reg command in cmd (bat file)?

You will probably get an UAC prompt when importing the reg file. If you accept that, you have more rights.

Since you are writing to the 'policies' key, you need to have elevated rights. This part of the registry protected, because it contains settings that are administered by your system administrator.

Alternatively, you may try to run regedit.exe from the command prompt.

regedit.exe /S yourfile.reg

.. should silently import the reg file. See RegEdit Command Line Options Syntax for more command line options.

What are the most widely used C++ vector/matrix math/linear algebra libraries, and their cost and benefit tradeoffs?

There are quite a few projects that have settled on the Generic Graphics Toolkit for this. The GMTL in there is nice - it's quite small, very functional, and been used widely enough to be very reliable. OpenSG, VRJuggler, and other projects have all switched to using this instead of their own hand-rolled vertor/matrix math.

I've found it quite nice - it does everything via templates, so it's very flexible, and very fast.


Edit:

After the comments discussion, and edits, I thought I'd throw out some more information about the benefits and downsides to specific implementations, and why you might choose one over the other, given your situation.

GMTL -

Benefits: Simple API, specifically designed for graphics engines. Includes many primitive types geared towards rendering (such as planes, AABB, quatenrions with multiple interpolation, etc) that aren't in any other packages. Very low memory overhead, quite fast, easy to use.

Downsides: API is very focused specifically on rendering and graphics. Doesn't include general purpose (NxM) matrices, matrix decomposition and solving, etc, since these are outside the realm of traditional graphics/geometry applications.

Eigen -

Benefits: Clean API, fairly easy to use. Includes a Geometry module with quaternions and geometric transforms. Low memory overhead. Full, highly performant solving of large NxN matrices and other general purpose mathematical routines.

Downsides: May be a bit larger scope than you are wanting (?). Fewer geometric/rendering specific routines when compared to GMTL (ie: Euler angle definitions, etc).

IMSL -

Benefits: Very complete numeric library. Very, very fast (supposedly the fastest solver). By far the largest, most complete mathematical API. Commercially supported, mature, and stable.

Downsides: Cost - not inexpensive. Very few geometric/rendering specific methods, so you'll need to roll your own on top of their linear algebra classes.

NT2 -

Benefits: Provides syntax that is more familiar if you're used to MATLAB. Provides full decomposition and solving for large matrices, etc.

Downsides: Mathematical, not rendering focused. Probably not as performant as Eigen.

LAPACK -

Benefits: Very stable, proven algorithms. Been around for a long time. Complete matrix solving, etc. Many options for obscure mathematics.

Downsides: Not as highly performant in some cases. Ported from Fortran, with odd API for usage.

Personally, for me, it comes down to a single question - how are you planning to use this. If you're focus is just on rendering and graphics, I like Generic Graphics Toolkit, since it performs well, and supports many useful rendering operations out of the box without having to implement your own. If you need general purpose matrix solving (ie: SVD or LU decomposition of large matrices), I'd go with Eigen, since it handles that, provides some geometric operations, and is very performant with large matrix solutions. You may need to write more of your own graphics/geometric operations (on top of their matrices/vectors), but that's not horrible.

Apache Name Virtual Host with SSL

You MUST add below part to enable NameVirtualHost functionality with given IP.

NameVirtualHost IP_Address:443

Excel formula to reference 'CELL TO THE LEFT'

Why not just use:

=ADDRESS(ROW(),COLUMN()-1)

instanceof Vs getClass( )

The reason that the performance of instanceof and getClass() == ... is different is that they are doing different things.

  • instanceof tests whether the object reference on the left-hand side (LHS) is an instance of the type on the right-hand side (RHS) or some subtype.

  • getClass() == ... tests whether the types are identical.

So the recommendation is to ignore the performance issue and use the alternative that gives you the answer that you need.

Is using the instanceOf operator bad practice ?

Not necessarily. Overuse of either instanceOf or getClass() may be "design smell". If you are not careful, you end up with a design where the addition of new subclasses results in a significant amount of code reworking. In most situations, the preferred approach is to use polymorphism.

However, there are cases where these are NOT "design smell". For example, in equals(Object) you need to test the actual type of the argument, and return false if it doesn't match. This is best done using getClass().


Terms like "best practice", "bad practice", "design smell", "antipattern" and so on should be used sparingly and treated with suspicion. They encourage black-or-white thinking. It is better to make your judgements in context, rather than based purely on dogma; e.g. something that someone said is "best practice". I recommend that everyone read No Best Practices if they haven't already done so.

Global variable Python classes

What you have is correct, though you will not call it global, it is a class attribute and can be accessed via class e.g Shape.lolwut or via an instance e.g. shape.lolwut but be careful while setting it as it will set an instance level attribute not class attribute

class Shape(object):
    lolwut = 1

shape = Shape()

print Shape.lolwut,  # 1
print shape.lolwut,  # 1

# setting shape.lolwut would not change class attribute lolwut 
# but will create it in the instance
shape.lolwut = 2

print Shape.lolwut,  # 1
print shape.lolwut,  # 2

# to change class attribute access it via class
Shape.lolwut = 3

print Shape.lolwut,  # 3
print shape.lolwut   # 2 

output:

1 1 1 2 3 2

Somebody may expect output to be 1 1 2 2 3 3 but it would be incorrect

How to insert a new line in strings in Android

I would personally prefer using "\n". This just puts a line break in Linux or Android.

For example,

String str = "I am the first part of the info being emailed.\nI am the second part.\n\nI am the third part.";

Output

I am the first part of the info being emailed.
I am the second part.

I am the third part.

A more generalized way would be to use,

System.getProperty("line.separator")

For example,

String str = "I am the first part of the info being emailed." + System.getProperty("line.separator") + "I am the second part." + System.getProperty("line.separator") + System.getProperty("line.separator") + "I am the third part.";

brings the same output as above. Here, the static getProperty() method of the System class can be used to get the "line.seperator" for the particular OS.

But this is not necessary at all, as the OS here is fixed, that is, Android. So, calling a method every time is a heavy and unnecessary operation.

Moreover, this also increases your code length and makes it look kind of messy. A "\n" is sweet and simple.

How to detect the end of loading of UITableView

here is how I do it in Swift 3

let threshold: CGFloat = 76.0 // threshold from bottom of tableView

internal func scrollViewDidScroll(_ scrollView: UIScrollView) {

    let contentOffset = scrollView.contentOffset.y
    let maximumOffset = scrollView.contentSize.height - scrollView.frame.size.height;

    if  (!isLoadingMore) &&  (maximumOffset - contentOffset <= threshold) {
        self.loadVideosList()
    }
}

How to temporarily exit Vim and go back

If you are on a Unix system, Ctrl + Z will suspend Vim and give you a shell.

Type fg to go back. Note that Vim creates a swap file while editing, and suspending Vim wouldn't delete that file (you aren't exiting Vim after all). On dumb terminals, this method was pretty standard for edit-compile-edit cycles using vi. I just found out that for me, gVim minimizes on typing Z.

How to pass multiple parameters from ajax to mvc controller?

Try this;

function X (id,parameter1,parameter2,...) {
    $.ajax({

            url: '@Url.Action("Actionre", "controller")',+ id,
            type: "Get",
            data: { parameter1: parameter1, parameter2: parameter2,...}

    }).done(function(result) {

        your code...
    });
}

So controller method would looks like :

public ActionResult ActionName(id,parameter1, parameter2,...)
{
   Your Code .......
}

How to have multiple colors in a Windows batch file?

Without external tools.This is a self-compiled bat/.net hybrid (should be saved as .BAT) that can be used on any system that have installed .net framework (it's a rare thing to see an windows without .NET framework even for the oldest XP/2003 installations) . It uses jscript.net compiler to create an exe capable to print strings with different background/foreground color only for the current line.

@if (@X)==(@Y) @end /* JScript comment
@echo off
setlocal

for /f "tokens=* delims=" %%v in ('dir /b /s /a:-d  /o:-n "%SystemRoot%\Microsoft.NET\Framework\*jsc.exe"') do (
   set "jsc=%%v"
)

if not exist "%~n0.exe" (
    "%jsc%" /nologo /out:"%~n0.exe" "%~dpsfnx0"
)

%~n0.exe %*

endlocal & exit /b %errorlevel%

*/

import System;

var arguments:String[] = Environment.GetCommandLineArgs();

var newLine = false;
var output = "";
var foregroundColor = Console.ForegroundColor;
var backgroundColor = Console.BackgroundColor;
var evaluate = false;
var currentBackground=Console.BackgroundColor;
var currentForeground=Console.ForegroundColor;


//http://stackoverflow.com/a/24294348/388389
var jsEscapes = {
  'n': '\n',
  'r': '\r',
  't': '\t',
  'f': '\f',
  'v': '\v',
  'b': '\b'
};

function decodeJsEscape(_, hex0, hex1, octal, other) {
  var hex = hex0 || hex1;
  if (hex) { return String.fromCharCode(parseInt(hex, 16)); }
  if (octal) { return String.fromCharCode(parseInt(octal, 8)); }
  return jsEscapes[other] || other;
}

function decodeJsString(s) {
  return s.replace(
      // Matches an escape sequence with UTF-16 in group 1, single byte hex in group 2,
      // octal in group 3, and arbitrary other single-character escapes in group 4.
      /\\(?:u([0-9A-Fa-f]{4})|x([0-9A-Fa-f]{2})|([0-3][0-7]{0,2}|[4-7][0-7]?)|(.))/g,
      decodeJsEscape);
}


function printHelp( ) {
   print( arguments[0] + "  -s string [-f foreground] [-b background] [-n] [-e]" );
   print( " " );
   print( " string          String to be printed" );
   print( " foreground      Foreground color - a " );
   print( "                 number between 0 and 15." );
   print( " background      Background color - a " );
   print( "                 number between 0 and 15." );
   print( " -n              Indicates if a new line should" );
   print( "                 be written at the end of the ");
   print( "                 string(by default - no)." );
   print( " -e              Evaluates special character " );
   print( "                 sequences like \\n\\b\\r and etc ");
   print( "" );
   print( "Colors :" );
   for ( var c = 0 ; c < 16 ; c++ ) {

        Console.BackgroundColor = c;
        Console.Write( " " );
        Console.BackgroundColor=currentBackground;
        Console.Write( "-"+c );
        Console.WriteLine( "" );
   }
   Console.BackgroundColor=currentBackground;



}

function errorChecker( e:Error ) {
        if ( e.message == "Input string was not in a correct format." ) {
            print( "the color parameters should be numbers between 0 and 15" );
            Environment.Exit( 1 );
        } else if (e.message == "Index was outside the bounds of the array.") {
            print( "invalid arguments" );
            Environment.Exit( 2 );
        } else {
            print ( "Error Message: " + e.message );
            print ( "Error Code: " + ( e.number & 0xFFFF ) );
            print ( "Error Name: " + e.name );
            Environment.Exit( 666 );
        }
}

function numberChecker( i:Int32 ){
    if( i > 15 || i < 0 ) {
        print("the color parameters should be numbers between 0 and 15");
        Environment.Exit(1);
    }
}


if ( arguments.length == 1 || arguments[1].toLowerCase() == "-help" || arguments[1].toLowerCase() == "-help"   ) {
    printHelp();
    Environment.Exit(0);
}

for (var arg = 1; arg <= arguments.length-1; arg++ ) {
    if ( arguments[arg].toLowerCase() == "-n" ) {
        newLine=true;
    }

    if ( arguments[arg].toLowerCase() == "-e" ) {
        evaluate=true;
    }

    if ( arguments[arg].toLowerCase() == "-s" ) {
        output=arguments[arg+1];
    }


    if ( arguments[arg].toLowerCase() == "-b" ) {

        try {
            backgroundColor=Int32.Parse( arguments[arg+1] );
        } catch(e) {
            errorChecker(e);
        }
    }

    if ( arguments[arg].toLowerCase() == "-f" ) {
        try {
            foregroundColor=Int32.Parse(arguments[arg+1]);
        } catch(e) {
            errorChecker(e);
        }
    }
}

Console.BackgroundColor = backgroundColor ;
Console.ForegroundColor = foregroundColor ;

if ( evaluate ) {
    output=decodeJsString(output);
}

if ( newLine ) {
    Console.WriteLine(output);  
} else {
    Console.Write(output);

}

Console.BackgroundColor = currentBackground;
Console.ForegroundColor = currentForeground;

Example coloroutput.bat -s "aa\nbb\n\u0025cc" -b 10 -f 3 -n -e

You can also check carlos' color function -> http://www.dostips.com/forum/viewtopic.php?f=3&t=4453

Root user/sudo equivalent in Cygwin?

What I usually do is have a registry "Open Here" helper in order to open a cygwin shell with administrative privileges quite easy from anywhere in my computer.

Be aware you have to have the cygwin "chere" package installed, use "chere -i -m" from an elevated cygwin shell first.

Assuming your cygwin installation is in C:\cygwin...

Here's the registry code:

Windows Registry Editor Version 5.00

[-HKEY_CLASSES_ROOT\Directory\shell\cygwin_bash]

[HKEY_CLASSES_ROOT\Directory\shell\cygwin_bash]
@="Open Cygwin Here as Root"
"HasLUAShield"=""

[HKEY_CLASSES_ROOT\Directory\shell\cygwin_bash\command]
@="c:\\cygwin\\bin\\mintty.exe -i /Cygwin-Terminal.ico -e /bin/xhere /bin/bash.exe"

[-HKEY_CLASSES_ROOT\Directory\Background\shell\cygwin_bash]

[HKEY_CLASSES_ROOT\Directory\Background\shell\cygwin_bash]
@="Open Cygwin Here as Root"
"HasLUAShield"=""

[HKEY_CLASSES_ROOT\Directory\Background\shell\cygwin_bash\command]
@="c:\\cygwin\\bin\\mintty.exe -i /Cygwin-Terminal.ico -e /bin/xhere /bin/bash.exe"

[-HKEY_CLASSES_ROOT\Drive\shell\cygwin_bash]

[HKEY_CLASSES_ROOT\Drive\shell\cygwin_bash]
@="Open Cygwin Here as Root"
"HasLUAShield"=""

[HKEY_CLASSES_ROOT\Drive\shell\cygwin_bash\command]
@="c:\\cygwin\\bin\\mintty.exe -i /Cygwin-Terminal.ico -e /bin/xhere /bin/bash.exe"

Hope this helps. Let me know if it works for you. Thanks.

PS: You can grab this code, copy and paste it and save it in a name.reg file to run it... or you can manually add the values.

How to use refs in React with Typescript

To use the callback style (https://facebook.github.io/react/docs/refs-and-the-dom.html) as recommended on React's documentation you can add a definition for a property on the class:

export class Foo extends React.Component<{}, {}> {
// You don't need to use 'references' as the name
references: {
    // If you are using other components be more specific than HTMLInputElement
    myRef: HTMLInputElement;
} = {
    myRef: null
}
...
 myFunction() {
    // Use like this
    this.references.myRef.focus();
}
...
render() {
    return(<input ref={(i: any) => { this.references.myRef = i; }}/>)
}

How to change background color of cell in table using java script

Try this:

function btnClick() {
    var x = document.getElementById("mytable").getElementsByTagName("td");
    x[0].innerHTML = "i want to change my cell color";
    x[0].style.backgroundColor = "yellow";            
}

Set from JS, backgroundColor is the equivalent of background-color in your style-sheet.

Note also that the .cells collection belongs to a table row, not to the table itself. To get all the cells from all rows you can instead use getElementsByTagName().

Demo: http://jsbin.com/ekituv/edit#preview

Short circuit Array.forEach like calling break

Found this solution on another site. You can wrap the forEach in a try / catch scenario.

if(typeof StopIteration == "undefined") {
 StopIteration = new Error("StopIteration");
}

try {
  [1,2,3].forEach(function(el){
    alert(el);
    if(el === 1) throw StopIteration;
  });
} catch(error) { if(error != StopIteration) throw error; }

More details here: http://dean.edwards.name/weblog/2006/07/enum/

How do I select an element in jQuery by using a variable for the ID?

row = $("body").find('#' + row_id);

More importantly doing the additional body.find has no impact on performance. The proper way to do this is simply:

row = $('#' + row_id);

Call external javascript functions from java code

Let us say your jsfunctions.js file has a function "display" and this file is stored in C:/Scripts/Jsfunctions.js

jsfunctions.js

var display = function(name) {
print("Hello, I am a Javascript display function",name);
return "display function return"
}

Now, in your java code, I would recommend you to use Java8 Nashorn. In your java class,

import java.io.FileNotFoundException;
import java.io.FileReader;

import javax.script.Invocable;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

class Test {
public void runDisplay() {
ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");
try {
  engine.eval(new FileReader("C:/Scripts/Jsfunctions.js"));
  Invocable invocable = (Invocable) engine;
  Object result;
  result = invocable.invokeFunction("display", helloWorld);
  System.out.println(result);
  System.out.println(result.getClass());
  } catch (FileNotFoundException | NoSuchMethodException | ScriptException e) {
    e.printStackTrace();
    }
  }
}

Note: Get the absolute path of your javascript file and replace in FileReader() and run the java code. It should work.

Convert String[] to comma separated string in java

Extention for prior Java 8 solution

String result = String.join(",", name);

If you need prefix or/ and suffix for array values

 StringJoiner joiner = new StringJoiner(",");
 for (CharSequence cs: name) {
     joiner.add("'" + cs + "'");
 }
 return joiner.toString();

Or simple method concept

  public static String genInValues(String delimiter, String prefix, String suffix, String[] name) {
    StringJoiner joiner = new StringJoiner(delimiter);
    for (CharSequence cs: name) {
      joiner.add(prefix + cs + suffix);
    }
    return joiner.toString();
  }

For example

For Oracle i need "id in (1,2,3,4,5)" 
then use genInValues(",", "", "", name);
But for Postgres i need "id in (values (1),(2),(3),(4),(5))"
then use genInValues(",", "(", ")", name);

How do I resolve a HTTP 414 "Request URI too long" error?

An excerpt from the RFC 2616: Hypertext Transfer Protocol -- HTTP/1.1:

The POST method is used to request that the origin server accept the entity enclosed in the request as a new subordinate of the resource identified by the Request-URI in the Request-Line. POST is designed to allow a uniform method to cover the following functions:

  • Annotation of existing resources;
  • Posting a message to a bulletin board, newsgroup, mailing list, or similar group of articles;
  • Providing a block of data, such as the result of submitting a form, to a data-handling process;
  • Extending a database through an append operation.

How can I specify a display?

When you are connecting to another machine over SSH, you can enable X-Forwarding in SSH, so that X windows are forwarded encrypted through the SSH tunnel back to your machine. You can enable X forwarding by appending -X to the ssh command line or setting ForwardX11 yes in your SSH config file.

To check if the X-Forwarding was set up successfully (the server might not allow it), just try if echo $DISPLAY outputs something like localhost:10.0.

How do you create a hidden div that doesn't create a line break or horizontal space?

Use style="display: none;". Also, you probably don't need to have the DIV, just setting the style to display: none on the checkbox would probably be sufficient.

Ruby 2.0.0p0 IRB warning: "DL is deprecated, please use Fiddle"

I got this resolution at openshift.com.

Resolution:

This error occurs only on Windows machine with Ruby 2.0.0 version. Until we officially support Ruby 2.0 please downgrade to Ruby 1.9.

On Windows, you can install Ruby 1.9.3 alongside 2.0. Change your %PATH% to c:\ruby193\ or whatever directory you installed to prior to installing the gem.

Unable to find velocity template resources

While using embedded jetty the property webapp.resource.loader.path should starts with slash:

webapp.resource.loader.path=/templates

otherwise templates will not be found in ../webapp/templates

How to tell if homebrew is installed on Mac OS X

Another one possible way:

# Check if Ninja is installed
if ! which ninja > /dev/null
then
echo 'Ninja installation...'
brew install ninja
fi

CodeIgniter removing index.php from url

you can go to application\config\config.php file and remove index.php


 $config['index_page'] = 'index.php';   // delete index.php

Change to


 $config['index_page'] = '';

Use of 'const' for function parameters

If the parameter is passed by value (and is not a reference), usually there is not much difference whether the parameter is declared as const or not (unless it contains a reference member -- not a problem for built-in types). If the parameter is a reference or pointer, it is usually better to protect the referenced/pointed-to memory, not the pointer itself (I think you cannot make the reference itself const, not that it matters much as you cannot change the referee). It seems a good idea to protect everything you can as const. You can omit it without fear of making a mistake if the parameters are just PODs (including built-in types) and there is no chance of them changing further along the road (e.g. in your example the bool parameter).

I didn't know about the .h/.cpp file declaration difference, but it does make some sense. At the machine code level, nothing is "const", so if you declare a function (in the .h) as non-const, the code is the same as if you declare it as const (optimizations aside). However, it helps you to enlist the compiler that you will not change the value of the variable inside the implementation of the function (.ccp). It might come handy in the case when you're inheriting from an interface that allows change, but you don't need to change to parameter to achieve the required functionality.

Calculate the date yesterday in JavaScript

//Create a date object using the current time
var now = new Date();

//Subtract one day from it
now.setDate(now.getDate()-1);

Error: org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'text/plain;charset=UTF-8' not supported

For me it turned out that I had a @JsonManagedReferece in one entity without a @JsonBackReference in the other referenced entity. This caused the marshaller to throw an error.

Display Two <div>s Side-by-Side

I removed the float from the second div to make it work.

http://jsfiddle.net/rhEyM/2/

'Incomplete final line' warning when trying to read a .csv file into R

Use readLines() (with warn = FALSE) to read the file into a character vector first.

After that use the text = option to read the vector into a data frame with read.table()

    pheasant <- read.table( 
        text = readLines(file.choose(), warn = FALSE), 
        header = TRUE,  
        sep = "," 
    )

How to get rid of `deprecated conversion from string constant to ‘char*’` warnings in GCC?

Why don't you use the -Wno-deprecated option to ignore deprecated warning messages?

Vertically aligning a checkbox

_x000D_
_x000D_
Add CSS:_x000D_
_x000D_
_x000D_
li {_x000D_
  display: table-row;_x000D_
 _x000D_
 }_x000D_
li div {_x000D_
   display: table-cell;_x000D_
   vertical-align: middle;_x000D_
_x000D_
  }_x000D_
.check{_x000D_
  width:20px;_x000D_
_x000D_
  }_x000D_
ul{_x000D_
   list-style: none;_x000D_
  }_x000D_
  
_x000D_
 <ul>_x000D_
       <li>_x000D_
_x000D_
           <div><label for="myid1">Subject1</label></div>_x000D_
            <div class="check"><input type="checkbox" value="1"name="subject" class="subject-list" id="myid1"></div>_x000D_
       </li>_x000D_
       <li>_x000D_
_x000D_
           <div><label for="myid2">Subject2</label></div>_x000D_
              <div class="check" ><input type="checkbox" value="2"  class="subject-list" name="subjct" id="myid2"></div>_x000D_
       </li>_x000D_
   </ul>
_x000D_
_x000D_
_x000D_

Converting a PDF to PNG

You can use one commandline with two commands (gs, convert) connected through a pipe, if the first command can write its output to stdout, and if the second one can read its input from stdin.

  1. Luckily, gs can write to stdout (... -o %stdout ...).
  2. Luckily, convert can read from stdin (convert -background transparent - output.png).

Problem solved:

  • GS used for alpha channel handling a special image,
  • convert used for creating transparent background,
  • pipe used to avoid writing out a temp file on disk.

Complete solution:

gs -sDEVICE=pngalpha       \
   -o %stdout              \
   -r144 cover.pdf         \
   |                       \
convert                    \
   -background transparent \
   -                       \
    cover.png

Update

If you want to have a separate PNG per PDF page, you can use the %d syntax:

gs -sDEVICE=pngalpha -o file-%03d.png -r144 cover.pdf

This will create PNG files named page-000.png, page-001.png, ... (Note that the %d-counting is zero-based -- file-000.png corresponds to page 1 of the PDF, 001 to page 2...

Or, if you want to keep your transparent background, for a 100-page PDF, do

for i in {1..100}; do        \
                             \
  gs -sDEVICE=pngalpha       \
     -dFirstPage="${i}"      \
     -dLastPage="${i}"       \
     -o %stdout              \
     -r144 input.pdf         \
     |                       \
  convert                    \
     -background transparent \
     -                       \
      page-${i}.png ;        \
                             \
done

nginx- duplicate default server error

Execute this at the terminal to see conflicting configurations listening to the same port:

grep -R default_server /etc/nginx

DateDiff to output hours and minutes

Try this query

select
    *,
    Days          = datediff(dd,0,DateDif),
    Hours         = datepart(hour,DateDif),
    Minutes       = datepart(minute,DateDif),
    Seconds       = datepart(second,DateDif),
    MS            = datepart(ms,DateDif)
from
    (select
         DateDif = EndDate-StartDate,
         aa.*
     from
         (  -- Test Data
          Select
              StartDate = convert(datetime,'20090213 02:44:37.923'),
              EndDate   = convert(datetime,'20090715 13:24:45.837')) aa
    ) a

Output

DateDif                  StartDate                EndDate                 Days Hours Minutes Seconds MS
-----------------------  -----------------------  ----------------------- ---- ----- ------- ------- ---
1900-06-02 10:40:07.913  2009-02-13 02:44:37.923  2009-07-15 13:24:45.837 152  10    40      7       913

(1 row(s) affected)

How do I make an HTML button not reload the page

In HTML:

<form onsubmit="return false">
</form>

in order to avoid refresh at all "buttons", even with onclick assigned.

A message body writer for Java type, class myPackage.B, and MIME media type, application/octet-stream, was not found

You need to specify the @Provider that @Produces(MediaType.APPLICATION_XML) from B.class
An add the package of your MessageBodyWriter<B.class> to your /WEB_INF/web.xml as:

<init-param>
<param-name>com.sun.jersey.config.property.packages</param-name>
<param-value>
your.providers.package
</param-value>
</init-param>

getting exception "IllegalStateException: Can not perform this action after onSaveInstanceState"

you can use FragmentActivity.onStart before popBackStackImmediate

like this:

public void backStackFragment() {
    this.start();
    getFragmentManager().popBackStackImmediate();
}

public void start(){
    FragmentActivity a = getActivity();
    if(a instanceof DepositPlanPadActivity){
      ((DepositPlanPadActivity)a).onStart();
    }
    if(a instanceof SmallChangePlanPad){
            ((SmallChangePlanPad)a).onStart();
        }
        if(a instanceof UserCenterActivity){
            ((UserCenterActivity)a).onStart();
        }
    }

http://jorryliu.blogspot.com/2014/09/illegalstateexception-can-not-perform.html

iPad browser WIDTH & HEIGHT standard

The pixel width and height of your page will depend on orientation as well as the meta viewport tag, if specified. Here are the results of running jquery's $(window).width() and $(window).height() on iPad 1 browser.

When page has no meta viewport tag:

  • Portrait: 980x1208
  • Landscape: 980x661

When page has either of these two meta tags:

<meta name="viewport" content="initial-scale=1,user-scalable=no,maximum-scale=1,width=device-width">

<meta name="viewport" content="initial-scale=1,user-scalable=no,maximum-scale=1">

  • Portrait: 768x946
  • Landscape: 1024x690

With <meta name="viewport" content="width=device-width">:

  • Portrait: 768x946
  • Landscape: 768x518

With <meta name="viewport" content="height=device-height">:

  • Portrait: 980x1024
  • Landscape: 980x1024

With <meta name="viewport" content="height=device-height,width=device-width">:

  • Portrait: 768x1024
  • Landscape: 768x1024

With <meta name="viewport" content="initial-scale=1,user-scalable=no,maximum-scale=1,width=device-width,height=device-height">

  • Portrait: 768x1024
  • Landscape: 1024x1024

With <meta name="viewport" content="initial-scale=1,user-scalable=no,maximum-scale=1,height=device-height">

  • Portrait: 831x1024
  • Landscape: 1520x1024

nginx: connect() failed (111: Connection refused) while connecting to upstream

I had the same problem when I wrote two upstreams in NGINX conf

upstream php_upstream {
    server unix:/var/run/php/my.site.sock;
    server 127.0.0.1:9000;
}

...

fastcgi_pass php_upstream;

but in /etc/php/7.3/fpm/pool.d/www.conf I listened the socket only

listen = /var/run/php/my.site.sock

So I need just socket, no any 127.0.0.1:9000, and I just removed IP+port upstream

upstream php_upstream {
    server unix:/var/run/php/my.site.sock;
}

This could be rewritten without an upstream

fastcgi_pass unix:/var/run/php/my.site.sock;

COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better?

Bottom Line

Use either COUNT(field) or COUNT(*), and stick with it consistently, and if your database allows COUNT(tableHere) or COUNT(tableHere.*), use that.

In short, don't use COUNT(1) for anything. It's a one-trick pony, which rarely does what you want, and in those rare cases is equivalent to count(*)

Use count(*) for counting

Use * for all your queries that need to count everything, even for joins, use *

SELECT boss.boss_id, COUNT(subordinate.*)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

But don't use COUNT(*) for LEFT joins, as that will return 1 even if the subordinate table doesn't match anything from parent table

SELECT boss.boss_id, COUNT(*)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

Don't be fooled by those advising that when using * in COUNT, it fetches entire row from your table, saying that * is slow. The * on SELECT COUNT(*) and SELECT * has no bearing to each other, they are entirely different thing, they just share a common token, i.e. *.

An alternate syntax

In fact, if it is not permitted to name a field as same as its table name, RDBMS language designer could give COUNT(tableNameHere) the same semantics as COUNT(*). Example:

For counting rows we could have this:

SELECT COUNT(emp) FROM emp

And they could make it simpler:

SELECT COUNT() FROM emp

And for LEFT JOINs, we could have this:

SELECT boss.boss_id, COUNT(subordinate)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

But they cannot do that (COUNT(tableNameHere)) since SQL standard permits naming a field with the same name as its table name:

CREATE TABLE fruit -- ORM-friendly name
(
fruit_id int NOT NULL,
fruit varchar(50), /* same name as table name, 
                and let's say, someone forgot to put NOT NULL */
shape varchar(50) NOT NULL,
color varchar(50) NOT NULL
)

Counting with null

And also, it is not a good practice to make a field nullable if its name matches the table name. Say you have values 'Banana', 'Apple', NULL, 'Pears' on fruit field. This will not count all rows, it will only yield 3, not 4

SELECT count(fruit) FROM fruit

Though some RDBMS do that sort of principle (for counting the table's rows, it accepts table name as COUNT's parameter), this will work in Postgresql (if there is no subordinate field in any of the two tables below, i.e. as long as there is no name conflict between field name and table name):

SELECT boss.boss_id, COUNT(subordinate)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

But that could cause confusion later if we will add a subordinate field in the table, as it will count the field(which could be nullable), not the table rows.

So to be on the safe side, use:

SELECT boss.boss_id, COUNT(subordinate.*)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

count(1): The one-trick pony

In particular to COUNT(1), it is a one-trick pony, it works well only on one table query:

SELECT COUNT(1) FROM tbl

But when you use joins, that trick won't work on multi-table queries without its semantics being confused, and in particular you cannot write:

-- count the subordinates that belongs to boss
SELECT boss.boss_id, COUNT(subordinate.1)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

So what's the meaning of COUNT(1) here?

SELECT boss.boss_id, COUNT(1)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

Is it this...?

-- counting all the subordinates only
SELECT boss.boss_id, COUNT(subordinate.boss_id)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

Or this...?

-- or is that COUNT(1) will also count 1 for boss regardless if boss has a subordinate
SELECT boss.boss_id, COUNT(*)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

By careful thought, you can infer that COUNT(1) is the same as COUNT(*), regardless of type of join. But for LEFT JOINs result, we cannot mold COUNT(1) to work as: COUNT(subordinate.boss_id), COUNT(subordinate.*)

So just use either of the following:

-- count the subordinates that belongs to boss
SELECT boss.boss_id, COUNT(subordinate.boss_id)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

Works on Postgresql, it's clear that you want to count the cardinality of the set

-- count the subordinates that belongs to boss
SELECT boss.boss_id, COUNT(subordinate.*)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

Another way to count the cardinality of the set, very English-like (just don't make a column with a name same as its table name) : http://www.sqlfiddle.com/#!1/98515/7

select boss.boss_name, count(subordinate)
from boss
left join subordinate on subordinate.boss_code = boss.boss_code
group by boss.boss_name

You cannot do this: http://www.sqlfiddle.com/#!1/98515/8

select boss.boss_name, count(subordinate.1)
from boss
left join subordinate on subordinate.boss_code = boss.boss_code
group by boss.boss_name

You can do this, but this produces wrong result: http://www.sqlfiddle.com/#!1/98515/9

select boss.boss_name, count(1)
from boss
left join subordinate on subordinate.boss_code = boss.boss_code
group by boss.boss_name

jquery disable form submit on enter

The overkill of having to capture and test every keystroke for the ENTER key really bugs me, so my solution relies on the following browser behavior:

Pressing ENTER will trigger a click event on the submit button (tested in IE11, Chrome 38, FF 31) ** (ref: http://mattsnider.com/how-forms-submit-when-pressing-enter/ )

So my solution is to remove the standard submit button (i.e. <input type="submit">) so that the above behavior fails because there's no submit button to magically click when ENTER is pressed. Instead, I use a jQuery click handler on a regular button to submit the form via jQuery's .submit() method.

<form id="myform" method="post">
  <input name="fav_color" type="text">
  <input name="fav_color_2" type="text">
<button type="button" id="form-button-submit">DO IT!</button>
</form>

<script>
 $('#form-button-submit').click(function(){
    $('#myform').submit();
  });
</script>

Demo: http://codepen.io/anon/pen/fxeyv?editors=101

** this behavior is not applicable if the form has only 1 input field and that field is a 'text' input; in this case the form will be submitted upon ENTER key even if no submit button is present in the HTML markup (e.g. a search field). This has been standard browser behavior since the 90s.

How many socket connections possible?

I achieved 1600k concurrent idle socket connections, and at the same time 57k req/s on a Linux desktop (16G RAM, I7 2600 CPU). It's a single thread http server written in C with epoll. Source code is on github, a blog here.

Edit:

I did 600k concurrent HTTP connections (client & server) on both the same computer, with JAVA/Clojure . detail info post, HN discussion: http://news.ycombinator.com/item?id=5127251

The cost of a connection(with epoll):

  • application need some RAM per connection
  • TCP buffer 2 * 4k ~ 10k, or more
  • epoll need some memory for a file descriptor, from epoll(7)

Each registered file descriptor costs roughly 90 bytes on a 32-bit kernel, and roughly 160 bytes on a 64-bit kernel.

Bash script plugin for Eclipse?

There exists now a dedicated bash script plugin called "Bash editor". It's available at eclipse market place:

Bash editor log

You can find it at https://marketplace.eclipse.org/content/bash-editor or by marketplace client when searching for "bash".

The plugin does also provide a debugger. Inisde official Bash Editor YouTube playlist you can find some tutorials about usage etc.

PS: I am the author of the mentioned plugin.

Get to UIViewController from UIView?

There is no way.

What I do is pass the UIViewController pointer to the UIView (or an appropriate inheritance). I'm sorry I can't help with the IB approach to the problem because I don't believe in IB.

To answer the first commenter: sometimes you do need to know who called you because it determines what you can do. For example with a database you might have read access only or read/write ...

Oracle PL Sql Developer cannot find my tnsnames.ora file

I had the same problema, but as described in the manual.pdf, you have to:

You are using an Oracle Instant Client but have not set all required environment variables:

  • PATH: Needs to include the Instant Client directory where oci.dll is located
  • TNS_ADMIN: Needs to point to the directory where tnsnames.ora is located.
  • NLS_LANG: Defines the language, territory, and character set for the client.

Regards

ipynb import another ipynb file

The issue is that a notebooks is not a plain python file. The steps to import the .ipynb file are outlined in the following: Importing notebook

I am pasting the code, so if you need it...you can just do a quick copy and paste. Notice that at the end I have the import primes statement. You'll have to change that of course. The name of my file is primes.ipynb. From this point on you can use the content inside that file as you would do regularly.

Wish there was a simpler method, but this is straight from the docs.
Note: I am using jupyter not ipython.

import io, os, sys, types
from IPython import get_ipython
from nbformat import current
from IPython.core.interactiveshell import InteractiveShell


def find_notebook(fullname, path=None):
    """find a notebook, given its fully qualified name and an optional path

    This turns "foo.bar" into "foo/bar.ipynb"
    and tries turning "Foo_Bar" into "Foo Bar" if Foo_Bar
    does not exist.
    """
    name = fullname.rsplit('.', 1)[-1]
    if not path:
        path = ['']
    for d in path:
        nb_path = os.path.join(d, name + ".ipynb")
        if os.path.isfile(nb_path):
            return nb_path
        # let import Notebook_Name find "Notebook Name.ipynb"
        nb_path = nb_path.replace("_", " ")
        if os.path.isfile(nb_path):
            return nb_path


class NotebookLoader(object):
    """Module Loader for Jupyter Notebooks"""
    def __init__(self, path=None):
        self.shell = InteractiveShell.instance()
        self.path = path

    def load_module(self, fullname):
        """import a notebook as a module"""
        path = find_notebook(fullname, self.path)

        print ("importing Jupyter notebook from %s" % path)

        # load the notebook object
        with io.open(path, 'r', encoding='utf-8') as f:
            nb = current.read(f, 'json')


        # create the module and add it to sys.modules
        # if name in sys.modules:
        #    return sys.modules[name]
        mod = types.ModuleType(fullname)
        mod.__file__ = path
        mod.__loader__ = self
        mod.__dict__['get_ipython'] = get_ipython
        sys.modules[fullname] = mod

        # extra work to ensure that magics that would affect the user_ns
        # actually affect the notebook module's ns
        save_user_ns = self.shell.user_ns
        self.shell.user_ns = mod.__dict__

        try:
        for cell in nb.worksheets[0].cells:
            if cell.cell_type == 'code' and cell.language == 'python':
                # transform the input to executable Python
                code = self.shell.input_transformer_manager.transform_cell(cell.input)
                # run the code in themodule
                exec(code, mod.__dict__)
        finally:
            self.shell.user_ns = save_user_ns
        return mod


class NotebookFinder(object):
    """Module finder that locates Jupyter Notebooks"""
    def __init__(self):
        self.loaders = {}

    def find_module(self, fullname, path=None):
        nb_path = find_notebook(fullname, path)
        if not nb_path:
            return

        key = path
        if path:
            # lists aren't hashable
            key = os.path.sep.join(path)

        if key not in self.loaders:
            self.loaders[key] = NotebookLoader(path)
        return self.loaders[key]

sys.meta_path.append(NotebookFinder())

import primes

How to extend an existing JavaScript array with another array, without creating a new array

Use Array.extend instead of Array.push for > 150,000 records.

if (!Array.prototype.extend) {
  Array.prototype.extend = function(arr) {
    if (!Array.isArray(arr)) {
      return this;
    }

    for (let record of arr) {
      this.push(record);
    }

    return this;
  };
}

How to get input text value on click in ReactJS

First of all, you can't pass to alert second argument, use concatenation instead

alert("Input is " + inputValue);

Example

However in order to get values from input better to use states like this

_x000D_
_x000D_
var MyComponent = React.createClass({_x000D_
  getInitialState: function () {_x000D_
    return { input: '' };_x000D_
  },_x000D_
_x000D_
  handleChange: function(e) {_x000D_
    this.setState({ input: e.target.value });_x000D_
  },_x000D_
_x000D_
  handleClick: function() {_x000D_
    console.log(this.state.input);_x000D_
  },_x000D_
_x000D_
  render: function() {_x000D_
    return (_x000D_
      <div>_x000D_
        <input type="text" onChange={ this.handleChange } />_x000D_
        <input_x000D_
          type="button"_x000D_
          value="Alert the text input"_x000D_
          onClick={this.handleClick}_x000D_
        />_x000D_
      </div>_x000D_
    );_x000D_
  }_x000D_
});_x000D_
_x000D_
ReactDOM.render(_x000D_
  <MyComponent />,_x000D_
  document.getElementById('container')_x000D_
);
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>_x000D_
<div id="container"></div>
_x000D_
_x000D_
_x000D_

Python Create unix timestamp five minutes in the future

Now in Python >= 3.3 you can just call the timestamp() method to get the timestamp as a float.

import datetime
current_time = datetime.datetime.now(datetime.timezone.utc)
unix_timestamp = current_time.timestamp() # works if Python >= 3.3

unix_timestamp_plus_5_min = unix_timestamp + (5 * 60)  # 5 min * 60 seconds

Search and replace in bash using regular expressions

This actually can be done in pure bash:

hello=ho02123ware38384you443d34o3434ingtod38384day
re='(.*)[0-9]+(.*)'
while [[ $hello =~ $re ]]; do
  hello=${BASH_REMATCH[1]}${BASH_REMATCH[2]}
done
echo "$hello"

...yields...

howareyoudoingtodday

Rails 4 Authenticity Token

If you're using jQuery with rails, be wary of allowing entry to methods without verifying the authenticity token.

jquery-ujs can manage the tokens for you

You should have it already as part of the jquery-rails gem, but you might need to include it in application.js with

//= require jquery_ujs

That's all you need - your ajax call should now work

For more information, see: https://github.com/rails/jquery-ujs

Define css class in django Forms

Answered my own question. Sigh

http://docs.djangoproject.com/en/dev/ref/forms/widgets/#django.forms.Widget.attrs

I didn't realize it was passed into the widget constructor.

Git clone without .git directory

Use

git clone --depth=1 --branch=master git://someserver/somerepo dirformynewrepo
rm -rf ./dirformynewrepo/.git
  • The depth option will make sure to copy the least bit of history possible to get that repo.
  • The branch option is optional and if not specified would get master.
  • The second line will make your directory dirformynewrepo not a Git repository any more.
  • If you're doing recursive submodule clone, the depth and branch parameter don't apply to the submodules.

react-router getting this.props.location in child components

If the above solution didn't work for you, you can use import { withRouter } from 'react-router-dom';


Using this you can export your child class as -

class MyApp extends Component{
    // your code
}

export default withRouter(MyApp);

And your class with Router -

// your code
<Router>
      ...
      <Route path="/myapp" component={MyApp} />
      // or if you are sending additional fields
      <Route path="/myapp" component={() =><MyApp process={...} />} />
<Router>

Convert a tensor to numpy array in Tensorflow?

A simple example could be,

    import tensorflow as tf
    import numpy as np
    a=tf.random_normal([2,3],0.0,1.0,dtype=tf.float32)  #sampling from a std normal
    print(type(a))
    #<class 'tensorflow.python.framework.ops.Tensor'>
    tf.InteractiveSession()  # run an interactive session in Tf.

n now if we want this tensor a to be converted into a numpy array

    a_np=a.eval()
    print(type(a_np))
    #<class 'numpy.ndarray'>

As simple as that!

Keyboard shortcuts in WPF

Although the top answers are correct, I personally like to work with attached properties to enable the solution to be applied to any UIElement, especially when the Window is not aware of the element that should be focused. In my experience I often see a composition of several view models and user controls, where the window is often nothing more that the root container.

Snippet

public sealed class AttachedProperties
{
    // Define the key gesture type converter
    [System.ComponentModel.TypeConverter(typeof(System.Windows.Input.KeyGestureConverter))]
    public static KeyGesture GetFocusShortcut(DependencyObject dependencyObject)
    {
        return (KeyGesture)dependencyObject?.GetValue(FocusShortcutProperty);
    }

    public static void SetFocusShortcut(DependencyObject dependencyObject, KeyGesture value)
    {
        dependencyObject?.SetValue(FocusShortcutProperty, value);
    }

    /// <summary>
    /// Enables window-wide focus shortcut for an <see cref="UIElement"/>.
    /// </summary>
    // Using a DependencyProperty as the backing store for FocusShortcut.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty FocusShortcutProperty =
        DependencyProperty.RegisterAttached("FocusShortcut", typeof(KeyGesture), typeof(AttachedProperties), new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.None, new PropertyChangedCallback(OnFocusShortcutChanged)));

    private static void OnFocusShortcutChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if (!(d is UIElement element) || e.NewValue == e.OldValue)
            return;

        var window = FindParentWindow(d);
        if (window == null)
            return;

        var gesture = GetFocusShortcut(d);
        if (gesture == null)
        {
            // Remove previous added input binding.
            for (int i = 0; i < window.InputBindings.Count; i++)
            {
                if (window.InputBindings[i].Gesture == e.OldValue && window.InputBindings[i].Command is FocusElementCommand)
                    window.InputBindings.RemoveAt(i--);
            }
        }
        else
        {
            // Add new input binding with the dedicated FocusElementCommand.
            // see: https://gist.github.com/shuebner20/349d044ed5236a7f2568cb17f3ed713d
            var command = new FocusElementCommand(element);
            window.InputBindings.Add(new InputBinding(command, gesture));
        }
    }
}

With this attached property you can define a focus shortcut for any UIElement. It will automatically register the input binding at the window containing the element.

Usage (XAML)

<TextBox x:Name="SearchTextBox"
         Text={Binding Path=SearchText}
         local:AttachedProperties.FocusShortcutKey="Ctrl+Q"/>

Source code

The full sample including the FocusElementCommand implementation is available as gist: https://gist.github.com/shuebner20/c6a5191be23da549d5004ee56bcc352d

Disclaimer: You may use this code everywhere and free of charge. Please keep in mind, that this is a sample that is not suitable for heavy usage. For example, there is no garbage collection of removed elements because the Command will hold a strong reference to the element.

How do you normalize a file path in Bash?

I made a builtin-only function to handle this with a focus on highest possible performance (for fun). It does not resolve symlinks, so it is basically the same as realpath -sm.

## A bash-only mimic of `realpath -sm`. 
## Give it path[s] as argument[s] and it will convert them to clean absolute paths
abspath () { 
  ${*+false} && { >&2 echo $FUNCNAME: missing operand; return 1; };
  local c s p IFS='/';  ## path chunk, absolute path, input path, IFS for splitting paths into chunks
  local -i r=0;         ## return value

  for p in "$@"; do
    case "$p" in        ## Check for leading backslashes, identify relative/absolute path
    '') ((r|=1)); continue;;
    //[!/]*)  >&2 echo "paths =~ ^//[^/]* are impl-defined; not my problem"; ((r|=2)); continue;;
    /*) ;;
    *)  p="$PWD/$p";;   ## Prepend the current directory to form an absolute path
    esac

    s='';
    for c in $p; do     ## Let IFS split the path at '/'s
      case $c in        ### NOTE: IFS is '/'; so no quotes needed here
      ''|.) ;;          ## Skip duplicate '/'s and '/./'s
      ..) s="${s%/*}";; ## Trim the previous addition to the absolute path string
      *)  s+=/$c;;      ### NOTE: No quotes here intentionally. They make no difference, it seems
      esac;
    done;

    echo "${s:-/}";     ## If xpg_echo is set, use `echo -E` or `printf $'%s\n'` instead
  done
  return $r;
}

Note: This function does not handle paths starting with //, as exactly two double slashes at the start of a path are implementation-defined behavior. However, it handles /, ///, and so on just fine.

This function seems to handle all edge cases properly, but there might still be some out there that I haven't dealt with.

Performance Note: when called with thousands of arguments, abspath runs about 10x slower than realpath -sm; when called with a single argument, abspath runs >110x faster than realpath -sm on my machine, mostly due to not needing to execute a new program every time.

Hibernate Union alternatives

I have a solution for one critical scenario (for which I struggled a lot )with union in HQL .

e.g. Instead of not working :-

select i , j from A a  , (select i , j from B union select i , j from C) d where a.i = d.i 

OR

select i , j from A a  JOIN (select i , j from B union select i , j from C) d on a.i = d.i 

YOU could do in Hibernate HQL ->

Query q1 =session.createQuery(select i , j from A a JOIN B b on a.i = b.i)
List l1 = q1.list();

Query q2 = session.createQuery(select i , j from A a JOIN C b on a.i = b.i)
List l2 = q2.list();

then u can add both list ->

l1.addAll(l2);

jQuery UI themes and HTML tables

Why noy just use the theme styles in the table? i.e.

<table>
  <thead class="ui-widget-header">
    <tr>
      <th>Id</th>
      <th>Description</th>
    </td>
  </thead>
  <tbody class="ui-widget-content">
    <tr>
      <td>...</td>
      <td>...</td>
    </tr>
      .
      .
      .
  </tbody>
</table>

And you don't need to use any code...

Array of strings in groovy

Most of the time you would create a list in groovy rather than an array. You could do it like this:

names = ["lucas", "Fred", "Mary"]

Alternately, if you did not want to quote everything like you did in the ruby example, you could do this:

names = "lucas Fred Mary".split()

Where is git.exe located?

For me on Windows 10: C:\Users\Paul\AppData\Local\GitHub\PortableGit_624c8416ee51e205b3f892d1d904e06e6f3c57c8\mingw32\bin\git.exe

How to count lines in a document?

If you want to check the total line of all the files in a directory ,you can use find and wc:

find . -type f -exec wc -l {} +

How to get access to job parameters from ItemReader, in Spring Batch?

Complement with an additional example, you can access all job parameters in JavaConfig class:

@Bean
@StepScope
public ItemStreamReader<GenericMessage> reader(@Value("#{jobParameters}") Map<String,Object> jobParameters){
          ....
}

Sending private messages to user

This is pretty simple here is an example

Add your command code here like:

if (cmd === `!dm`) {
 let dUser =
  message.guild.member(message.mentions.users.first()) ||
  message.guild.members.get(args[0]);
 if (!dUser) return message.channel.send("Can't find user!");
 if (!message.member.hasPermission('ADMINISTRATOR'))
  return message.reply("You can't you that command!");
 let dMessage = args.join(' ').slice(22);
 if (dMessage.length < 1) return message.reply('You must supply a message!');

 dUser.send(`${dUser} A moderator from WP Coding Club sent you: ${dMessage}`);

 message.author.send(
  `${message.author} You have sent your message to ${dUser}`
 );
}

error while loading shared libraries: libncurses.so.5:

If libncurses is not installed then install it and try again. sudo apt-get install libncurses5:i386

or sudo apt-get install libncurses5 for 64 bit binaries

Also install the collection of libraries by using this command sudo apt-get install ia32-libs

Custom header to HttpClient request

I have found the answer to my question.

client.DefaultRequestHeaders.Add("X-Version","1");

That should add a custom header to your request

How to convert a string to character array in c (or) how to extract a single char form string?

In C, there's no (real, distinct type of) strings. Every C "string" is an array of chars, zero terminated.

Therefore, to extract a character c at index i from string your_string, just use

char c = your_string[i];

Index is base 0 (first character is your_string[0], second is your_string[1]...).

Converting a JToken (or string) to a given Type

I was able to convert using below method for my WebAPI:

[HttpPost]
public HttpResponseMessage Post(dynamic item) // Passing parameter as dynamic
{
JArray itemArray = item["Region"]; // You need to add JSON.NET library
JObject obj = itemArray[0] as JObject;  // Converting from JArray to JObject
Region objRegion = obj.ToObject<Region>(); // Converting to Region object
}

Select2 open dropdown on focus

I've tried a pretty ugly solution but it fixed my problem.

    var tabPressed = false;

    $(document).keydown(function (e) {
        // Listening tab button.
        if (e.which == 9) {
            tabPressed = true;
        }
    });

    $(document).on('focus', '.select2', function() {
        if (tabPressed) {
            tabPressed = false;
            $(this).siblings('select').select2('open');
        }
    });

Java 'file.delete()' Is not Deleting Specified File

I made the mistake of opening a BufferedReader like:

File f = new File("somefile.txt");
BufferedReader br = new BufferedReader(new FileReader(f));

...and of course I could not execute the f.delete() because I wrapped the FileReader instead of instantiating its own variable where I could explicitly close it. Duh...

Once I coded:

File f = new File("somefile.txt");
FileReader fread = new FileReader(f);
BufferedReader br = new BufferedReader(fread);

I could issue a br.close(); br=null; fread.close(); fread=null; and the f.delete() worked fine.

jQuery Data vs Attr?

The main difference between the two is where it is stored and how it is accessed.

$.fn.attr stores the information directly on the element in attributes which are publicly visible upon inspection, and also which are available from the element's native API.

$.fn.data stores the information in a ridiculously obscure place. It is located in a closed over local variable called data_user which is an instance of a locally defined function Data. This variable is not accessible from outside of jQuery directly.

Data set with attr()

  • accessible from $(element).attr('data-name')
  • accessible from element.getAttribute('data-name'),
  • if the value was in the form of data-name also accessible from $(element).data(name) and element.dataset['name'] and element.dataset.name
  • visible on the element upon inspection
  • cannot be objects

Data set with .data()

  • accessible only from .data(name)
  • not accessible from .attr() or anywhere else
  • not publicly visible on the element upon inspection
  • can be objects

Which browsers support <script async="async" />?

A comprehensive list of browser versions supporting the async parameter is available here

How can I change the Java Runtime Version on Windows (7)?

If you are using windows 10 or windows server 2012, the steps to change the java runtime version is this:

  1. Open regedit using 'Run'
  2. Navigate to HKEY_LOCAL_MACHINE -> SOFTWARE -> JavaSoft -> Java Runtime Environment
  3. Here you will see all the versions of java you installed on your PC. For me I have several versions of java 1.8 installed, so the folder displayed here are 1.8, 1.8.0_162 and 1.8.0_171
  4. Click the '1.8' folder, then double click the JavaHome and RuntimeLib keys, Change the version number inside to whichever Java version you want your PC to run on. For example, if the Value data of the key is 'C:\Program Files\Java\jre1.8.0_171', you can change this to 'C:\Program Files\Java\jre1.8.0_162'.
  5. You can then verify the version change by typing 'java -version' on the command line.

Implementing autocomplete

Update: This answer has led to the development of ng2-completer an Angular2 autocomplete component. This is the list of existing autocomplete components for Angular2:

  1. ng2-completer
  2. ng2-auto-complete
  3. ng2-typeahead

Credit goes to @dan-cancro for coming up with the idea

Keeping the original answer for those who wish to create their own directive:

To display autocomplete list we first need an attribute directive that will return the list of suggestions based on the input text and then display them in a dropdown. The directive has 2 options to display the list:

  1. Obtain a reference to the nativeElement and manipulate the DOM directly
  2. Dynamically load a list component using DynamicComponentLoader

It looks to me that 2nd way is a better choice as it uses angular 2 core mechanisms instead of bypassing them by working directly with the DOM and therefore I'll use this method.

This is the directive code:

"use strict";
import {Directive, DynamicComponentLoader, Input, ComponentRef, Output, EventEmitter, OnInit, ViewContainerRef} from "@angular/core";
import {Promise} from "es6-promise";
import {AutocompleteList} from "./autocomplete-list";

@Directive({
    selector: "[ng2-autocomplete]", // The attribute for the template that uses this directive
    host: {
        "(keyup)": "onKey($event)" // Liten to keyup events on the host component
    }
})
export class AutocompleteDirective implements OnInit {
    // The search function should be passed as an input
    @Input("ng2-autocomplete") public search: (term: string) => Promise<Array<{ text: string, data: any }>>;
    // The directive emits ng2AutocompleteOnSelect event when an item from the list is selected
    @Output("ng2AutocompleteOnSelect") public selected = new EventEmitter();

    private term = "";
    private listCmp: ComponentRef<AutocompleteList> = undefined;
    private refreshTimer: any = undefined;
    private searchInProgress = false;
    private searchRequired = false;

    constructor( private viewRef: ViewContainerRef, private dcl: DynamicComponentLoader) { }
    /**
     * On key event is triggered when a key is released on the host component
     * the event starts a timer to prevent concurrent requests
     */
    public onKey(event: any) {
        if (!this.refreshTimer) {
            this.refreshTimer = setTimeout(
            () => {
                if (!this.searchInProgress) {
                    this.doSearch();
                } else {
                    // If a request is in progress mark that a new search is required
                    this.searchRequired = true;
                }
            },
            200);
        }
        this.term = event.target.value;
        if (this.term === "" && this.listCmp) {
            // clean the list if the search term is empty
            this.removeList();
        }
    }

    public ngOnInit() {
        // When an item is selected remove the list
        this.selected.subscribe(() => {
            this.removeList();
        });
    }

    /**
     * Call the search function and handle the results
     */
    private doSearch() {
        this.refreshTimer = undefined;
        // if we have a search function and a valid search term call the search
        if (this.search && this.term !== "") {
            this.searchInProgress = true;
            this.search(this.term)
            .then((res) => {
                this.searchInProgress = false;
                // if the term has changed during our search do another search
                if (this.searchRequired) {
                    this.searchRequired = false;
                    this.doSearch();
                } else {
                    // display the list of results
                    this.displayList(res);
                }
            })
            .catch(err => {
                console.log("search error:", err);
                this.removeList();
            });
        }
    }

    /**
     * Display the list of results
     * Dynamically load the list component if it doesn't exist yet and update the suggestions list
     */
    private displayList(list: Array<{ text: string, data: any }>) {
        if (!this.listCmp) {
            this.dcl.loadNextToLocation(AutocompleteList, this.viewRef)
            .then(cmp => {
                // The component is loaded
                this.listCmp = cmp;
                this.updateList(list);
                // Emit the selectd event when the component fires its selected event
                (<AutocompleteList>(this.listCmp.instance)).selected
                    .subscribe(selectedItem => {

                    this.selected.emit(selectedItem);
                });
            });
        } else {
            this.updateList(list);
        }
    }

    /**
     * Update the suggestions list in the list component
     */
    private updateList(list: Array<{ text: string, data: any }>) {
        if (this.listCmp) {
            (<AutocompleteList>(this.listCmp.instance)).list = list;
        }
    }

    /**
     * remove the list component
     */
    private removeList() {
        this.searchInProgress = false;
        this.searchRequired = false;
        if (this.listCmp) {
            this.listCmp.destroy();
            this.listCmp = undefined;
        }
    }
}

The directive dynamically loads a dropdown component, this is a sample of such a component using bootstrap 4:

"use strict";
import {Component, Output, EventEmitter} from "@angular/core";

@Component({
    selector: "autocomplete-list",
    template: `<div class="dropdown-menu  search-results">
                    <a *ngFor="let item of list" class="dropdown-item" (click)="onClick(item)">{{item.text}}</a>
               </div>`, // Use a bootstrap 4 dropdown-menu to display the list
    styles: [".search-results { position: relative; right: 0; display: block; padding: 0; overflow: hidden; font-size: .9rem;}"]
})
export class AutocompleteList  {
    // Emit a selected event when an item in the list is selected
    @Output() public selected = new EventEmitter();

    public list;

    /**
     * Listen for a click event on the list
     */
    public onClick(item: {text: string, data: any}) {
        this.selected.emit(item);
    }
}

To use the directive in another component you need to import the directive, include it in the components directives and provide it with a search function and event handler for the selection:

 "use strict";
import {Component} from "@angular/core";

import {AutocompleteDirective} from "../component/ng2-autocomplete/autocomplete";

@Component({
    selector: "my-cmp",
    directives: [AutocompleteDirective],
    template: `<input class="form-control" type="text" [ng2-autocomplete]="search()" (ng2AutocompleteOnSelect)="onItemSelected($event)" autocomplete="off">`
})
export class MyComponent  {

    /**
     * generate a search function that returns a Promise that resolves to array of text and optionally additional data
     */  
    public search() {
        return (filter: string): Promise<Array<{ text: string, data: any }>> => {
            // do the search
            resolve({text: "one item", data: null});
        };
    }

    /**
     * handle item selection
     */  
    public onItemSelected(selected: { text: string, data: any }) {
        console.log("selected: ", selected.text);
    }
}

Update: code compatible with angular2 rc.1

How do I grant read access for a user to a database in SQL Server?

This is a two-step process:

  1. you need to create a login to SQL Server for that user, based on its Windows account

    CREATE LOGIN [<domainName>\<loginName>] FROM WINDOWS;
    
  2. you need to grant this login permission to access a database:

    USE (your database)
    CREATE USER (username) FOR LOGIN (your login name)
    

Once you have that user in your database, you can give it any rights you want, e.g. you could assign it the db_datareader database role to read all tables.

USE (your database)
EXEC sp_addrolemember 'db_datareader', '(your user name)'

react router v^4.0.0 Uncaught TypeError: Cannot read property 'location' of undefined

I've tried everything suggested here but didn't work for me. So in case I can help anyone with a similar issue, every single tutorial I've checked is not updated to work with version 4.

Here is what I've done to make it work

import React from 'react';
import App from './App';

import ReactDOM from 'react-dom';
import {
    HashRouter,
    Route
} from 'react-router-dom';


 ReactDOM.render((
        <HashRouter>
            <div>
                <Route path="/" render={()=><App items={temasArray}/>}/>
            </div>
        </HashRouter >
    ), document.getElementById('root'));

That's the only way I have managed to make it work without any errors or warnings.

In case you want to pass props to your component for me the easiest way is this one:

 <Route path="/" render={()=><App items={temasArray}/>}/>

How to sort an array of objects in Java?

public class Student implements Comparable<Student> {

    private int sid;
    private String sname;

    public Student(int sid, String sname) {
        super();
        this.sid = sid;
        this.sname = sname;
    }

    public int getSid() {
        return sid;
    }

    public void setSid(int sid) {
        this.sid = sid;
    }

    public String getSname() {
        return sname;
    }

    public void setSname(String sname) {
        this.sname = sname;
    }

    @Override
    public String toString() {
        return "Student [sid=" + sid + ", sname=" + sname + "]";
    }

    public int compareTo(Student o) {
        if (this.getSname().compareTo(o.getSname()) > 1) {
            return toString().compareTo(o.getSname());
        } else if (this.getSname().compareTo(o.getSname()) < 1) {
            return toString().compareTo(o.getSname());
        }
        return 0;
    }

}

How to retrieve a module's path?

When you import a module, yo have access to plenty of information. Check out dir(a_module). As for the path, there is a dunder for that: a_module.__path__. You can also just print the module itself.

>>> import a_module
>>> print(dir(a_module))
['__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__path__', '__spec__']
>>> print(a_module.__path__)
['/.../.../a_module']
>>> print(a_module)
<module 'a_module' from '/.../.../a_module/__init__.py'>

Java constructor/method with optional parameters?

You can't have optional arguments that default to a certain value in Java. The nearest thing to what you are talking about is java varargs whereby you can pass an arbitrary number of arguments (of the same type) to a method.

How to select a CRAN mirror in R

If you need to set the mirror in a non-interactive way (for example doing an rbundler install in a deploy script) you can do it in this way:

First manually run:

chooseCRANmirror()

Pick the mirror number that is best for you and remember it. Then to automate the selection:

R -e 'chooseCRANmirror(graphics=FALSE, ind=87);library(rbundler);bundle()'

Where 87 is the number of the mirror you would like to use. This snippet also installs the rbundle for you. You can omit that if you like.

No Multiline Lambda in Python: Why not?

Look at the following:

map(multilambda x:
      y=x+1
      return y
   , [1,2,3])

Is this a lambda returning (y, [1,2,3]) (thus map only gets one parameter, resulting in an error)? Or does it return y? Or is it a syntax error, because the comma on the new line is misplaced? How would Python know what you want?

Within the parens, indentation doesn't matter to python, so you can't unambiguously work with multilines.

This is just a simple one, there's probably more examples.

How to replace all special character into a string using C#

Yes, you can use regular expressions in C#.

Using regular expressions with C#:

using System.Text.RegularExpressions;

string your_String = "Hello@Hello&Hello(Hello)";
string my_String =  Regex.Replace(your_String, @"[^0-9a-zA-Z]+", ",");

How to use Google App Engine with my own naked domain (not subdomain)?

[update 2015-09-28] Now Google lets you add custom domains (including naked domains) and setup SSL without the need of Google Apps. For details refer to here: https://cloud.google.com/appengine/docs/using-custom-domains-and-ssl?hl=en

I just discovered today (as of 2014-04-11) a new custom domain settings page is available from Google Developers Console:

1. Go to https://console.developers.google.com/project 2. Click on your project 3. On the left click "App Engine" 4. Click "Settings"

There you go! You can configure custom domain without the need of Google App account!

How to write specific CSS for mozilla, chrome and IE

For that

  • You can scan user Agent and find out which browser, its version. Including the OS for OS specific styles
  • You can use various CSS Hacks for specific browser
  • Or Scripts or Plugins to indentify the browser and apply various classes to the elements

Using PHP

See

Then then create the dynamic CSS file as per the detected browser

Here is a CSS Hacks list

/***** Selector Hacks ******/

/* IE6 and below */
* html #uno  { color: red }

/* IE7 */
*:first-child+html #dos { color: red } 

/* IE7, FF, Saf, Opera  */
html>body #tres { color: red }

/* IE8, FF, Saf, Opera (Everything but IE 6,7) */
html>/**/body #cuatro { color: red }

/* Opera 9.27 and below, safari 2 */
html:first-child #cinco { color: red }

/* Safari 2-3 */
html[xmlns*=""] body:last-child #seis { color: red }

/* safari 3+, chrome 1+, opera9+, ff 3.5+ */
body:nth-of-type(1) #siete { color: red }

/* safari 3+, chrome 1+, opera9+, ff 3.5+ */
body:first-of-type #ocho {  color: red }

/* saf3+, chrome1+ */
@media screen and (-webkit-min-device-pixel-ratio:0) {
 #diez  { color: red  }
}

/* iPhone / mobile webkit */
@media screen and (max-device-width: 480px) {
 #veintiseis { color: red  }
}


/* Safari 2 - 3.1 */
html[xmlns*=""]:root #trece  { color: red  }

/* Safari 2 - 3.1, Opera 9.25 */
*|html[xmlns*=""] #catorce { color: red  }

/* Everything but IE6-8 */
:root *> #quince { color: red  }

/* IE7 */
*+html #dieciocho {  color: red }

/* Firefox only. 1+ */
#veinticuatro,  x:-moz-any-link  { color: red }

/* Firefox 3.0+ */
#veinticinco,  x:-moz-any-link, x:default  { color: red  }



/***** Attribute Hacks ******/

/* IE6 */
#once { _color: blue }

/* IE6, IE7 */
#doce { *color: blue; /* or #color: blue */ }

/* Everything but IE6 */
#diecisiete { color/**/: blue }

/* IE6, IE7, IE8 */
#diecinueve { color: blue\9; }

/* IE7, IE8 */
#veinte { color/*\**/: blue\9; }

/* IE6, IE7 -- acts as an !important */
#veintesiete { color: blue !ie; } /* string after ! can be anything */

Source: http://paulirish.com/2009/browser-specific-css-hacks/

If you want to use Plugin then here is one

http://rafael.adm.br/css_browser_selector/

What does "for" attribute do in HTML <label> tag?

The for attribute of the <label> tag should be equal to the id attribute of the related element to bind them together.

javax.net.ssl.SSLHandshakeException: Received fatal alert: handshake_failure

Issue resolved.!!! Below are the solutions.

For Java 6: Add below jars into {JAVA_HOME}/jre/lib/ext. 1. bcprov-ext-jdk15on-154.jar 2. bcprov-jdk15on-154.jar

Add property into {JAVA_HOME}/jre/lib/security/java.security security.provider.1=org.bouncycastle.jce.provider.BouncyCastleProvider

Java 7:download jar from below link and add to {JAVA_HOME}/jre/lib/security http://www.oracle.com/technetwork/java/javase/downloads/jce-7-download-432124.html

Java 8:download jar from below link and add to {JAVA_HOME}/jre/lib/security http://www.oracle.com/technetwork/java/javase/downloads/jce8-download-2133166.html

Issue is that it is failed to decrypt 256 bits of encryption.

Should I use past or present tense in git commit messages?

does it matter? people are generally smart enough to interpret messages correctly, if they aren't you probably shouldn't let them access your repository anyway!

SQL Server - NOT IN

It's because of the way NOT IN works.

To avoid these headaches (and for a faster query in many cases), I always prefer NOT EXISTS:

SELECT  *  
FROM Table1 t1 
WHERE NOT EXISTS (
    SELECT * 
    FROM Table2 t2 
    WHERE t1.MAKE = t2.MAKE
    AND   t1.MODEL = t2.MODEL
    AND   t1.[Serial Number] = t2.[serial number]);

Why when I transfer a file through SFTP, it takes longer than FTP?

Yes, encryption add some load to your cpu, but if your cpu is not ancient that should not affect as much as you say.

If you enable compression for SSH, SCP is actually faster than FTP despite the SSH encryption (if I remember, twice as fast as FTP for the files I tried). I haven't actually used SFTP, but I believe it uses SCP for the actual file transfer. So please try this and let us know :-)

Android java.exe finished with non-zero exit value 1

This is likely due to your app exceeding the 65k method count, thus causing a dex error. There is no solution, other than enabling multidexing in your app.

Merging two arrayLists into a new arrayList, with no duplicates and in order, in Java

your nested for loop

 for(int j = 0; j < array2.size(); i++){

is infinite as j will always equal to zero, on the other hand, i will be increased at will in this loop. You get OutOfBoundaryException when i is larger than plusArray.size()

grabbing first row in a mysql query only

To return only one row use LIMIT 1:

SELECT *
FROM tbl_foo
WHERE name = 'sarmen'
LIMIT 1

It doesn't make sense to say 'first row' or 'last row' unless you have an ORDER BY clause. Assuming you add an ORDER BY clause then you can use LIMIT in the following ways:

  • To get the first row use LIMIT 1.
  • To get the 2nd row you can use limit with an offset: LIMIT 1, 1.
  • To get the last row invert the order (change ASC to DESC or vice versa) then use LIMIT 1.

Asynchronous file upload (AJAX file upload) using jsp and javascript

The latest dwr (http://directwebremoting.org/dwr/index.html) has ajax file uploads, complete with examples and nice stuff for users (like progress indicators and such).

It looks pretty nifty and dwr is fairly easy to use in general so this will be pretty good as well.

How to force a line break on a Javascript concatenated string?

You need to use \n inside quotes.

document.getElementById("address_box").value = (title + "\n" + address + "\n" + address2 + "\n" + address3 + "\n" + address4)

\n is called a EOL or line-break, \n is a common EOL marker and is commonly refereed to as LF or line-feed, it is a special ASCII character

EF Code First "Invalid column name 'Discriminator'" but no inheritance

I get the error in another situation, and here are the problem and the solution:

I have 2 classes derived from a same base class named LevledItem:

public partial class Team : LeveledItem
{
   //Everything is ok here!
}
public partial class Story : LeveledItem
{
   //Everything is ok here!
}

But in their DbContext, I copied some code but forget to change one of the class name:

public class MFCTeamDbContext : DbContext
{
    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        //Other codes here
        modelBuilder.Entity<LeveledItem>()
            .Map<Team>(m => m.Requires("Type").HasValue(ItemType.Team));
    }

public class ProductBacklogDbContext : DbContext
{
    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        //Other codes here
        modelBuilder.Entity<LeveledItem>()
            .Map<Team>(m => m.Requires("Type").HasValue(ItemType.Story));
    }

Yes, the second Map< Team> should be Map< Story>. And it cost me half a day to figure it out!

What exactly is \r in C language?

' \r ' means carriage return.

The \r means nothing special as a consequence.For character-mode terminals (typically emulating even-older printing ones as above), in raw mode, \r and \n act similarly (except both in terms of the cursor, as there is no carriage or roller . Historically a \n was used to move the carriage down, while the \r was used to move the carriage back to the left side of the screen.

Content Security Policy: The page's settings blocked the loading of a resource

You can disable them in your browser.

Firefox

Type about:config in the Firefox address bar and find security.csp.enable and set it to false.

Chrome

You can install the extension called Disable Content-Security-Policy to disable CSP.

PHP mail not working for some reason

Check your SMTP settings in your php.ini file. Your host should have some documentation about what credentials to use. Perhaps you can check your error log file, it might have more information available.

SELECT *, COUNT(*) in SQLite

SELECT *, COUNT(*) FROM my_table is not what you want, and it's not really valid SQL, you have to group by all the columns that's not an aggregate.

You'd want something like

SELECT somecolumn,someothercolumn, COUNT(*) 
   FROM my_table 
GROUP BY somecolumn,someothercolumn

Checking if date is weekend PHP

If you're using PHP 5.5 or PHP 7 above, you may want to use:

function isTodayWeekend() {
    return in_array(date("l"), ["Saturday", "Sunday"]);
}

and it will return "true" if today is weekend and "false" if not.

VBA EXCEL Multiple Nested FOR Loops that Set two variable for expression

I can't get to your google docs file at the moment but there are some issues with your code that I will try to address while answering

Sub stituterangersNEW()
Dim t As Range
Dim x As Range
Dim dify As Boolean
Dim difx As Boolean
Dim time2 As Date
Dim time1 As Date

    'You said time1 doesn't change, so I left it in a singe cell.
    'If that is not correct, you will have to play with this some more.
    time1 = Range("A6").Value

    'Looping through each of our output cells.
    For Each t In Range("B7:E9") 'Change these to match your real ranges.

        'Looping through each departure date/time.
        '(Only one row in your example. This can be adjusted if needed.)
        For Each x In Range("B2:E2") 'Change these to match your real ranges.
            'Check to see if our dep time corresponds to
            'the matching column in our output
            If t.Column = x.Column Then
                'If it does, then check to see what our time value is
                If x > 0 Then
                    time2 = x.Value
                    'Apply the change to the output cell.
                    t.Value = time1 - time2
                    'Exit out of this loop and move to the next output cell.
                    Exit For
                End If
            End If
            'If the columns don't match, or the x value is not a time
            'then we'll move to the next dep time (x)
        Next x
    Next t

End Sub

EDIT

I changed you worksheet to play with (see above for the new Sub). This probably does not suite your needs directly, but hopefully it will demonstrate the conept behind what I think you want to do. Please keep in mind that this code does not follow all the coding best preactices I would recommend (e.g. validating the time is actually a TIME and not some random other data type).

     A                      B                   C                   D                  E
1    LOAD_NUMBER            1                   2                   3                  4
2    DEPARTURE_TIME_DATE    11/12/2011 19:30    11/12/2011 19:30    11/12/2011 19:30    11/12/2011 20:00                
4    Dry_Refrig 7585.1  0   10099.8 16700
6    1/4/2012 19:30

Using the sub I got this output:

    A           B             C             D             E
7   Friday      1272:00:00    1272:00:00    1272:00:00    1271:30:00
8   Saturday    1272:00:00    1272:00:00    1272:00:00    1271:30:00
9   Thursday    1272:00:00    1272:00:00    1272:00:00    1271:30:00

Correct format specifier to print pointer or address?

The simplest answer, assuming you don't mind the vagaries and variations in format between different platforms, is the standard %p notation.

The C99 standard (ISO/IEC 9899:1999) says in §7.19.6.1 ¶8:

p The argument shall be a pointer to void. The value of the pointer is converted to a sequence of printing characters, in an implementation-defined manner.

(In C11 — ISO/IEC 9899:2011 — the information is in §7.21.6.1 ¶8.)

On some platforms, that will include a leading 0x and on others it won't, and the letters could be in lower-case or upper-case, and the C standard doesn't even define that it shall be hexadecimal output though I know of no implementation where it is not.

It is somewhat open to debate whether you should explicitly convert the pointers with a (void *) cast. It is being explicit, which is usually good (so it is what I do), and the standard says 'the argument shall be a pointer to void'. On most machines, you would get away with omitting an explicit cast. However, it would matter on a machine where the bit representation of a char * address for a given memory location is different from the 'anything else pointer' address for the same memory location. This would be a word-addressed, instead of byte-addressed, machine. Such machines are not common (probably not available) these days, but the first machine I worked on after university was one such (ICL Perq).

If you aren't happy with the implementation-defined behaviour of %p, then use C99 <inttypes.h> and uintptr_t instead:

printf("0x%" PRIXPTR "\n", (uintptr_t)your_pointer);

This allows you to fine-tune the representation to suit yourself. I chose to have the hex digits in upper-case so that the number is uniformly the same height and the characteristic dip at the start of 0xA1B2CDEF appears thus, not like 0xa1b2cdef which dips up and down along the number too. Your choice though, within very broad limits. The (uintptr_t) cast is unambiguously recommended by GCC when it can read the format string at compile time. I think it is correct to request the cast, though I'm sure there are some who would ignore the warning and get away with it most of the time.


Kerrek asks in the comments:

I'm a bit confused about standard promotions and variadic arguments. Do all pointers get standard-promoted to void*? Otherwise, if int* were, say, two bytes, and void* were 4 bytes, then it'd clearly be an error to read four bytes from the argument, non?

I was under the illusion that the C standard says that all object pointers must be the same size, so void * and int * cannot be different sizes. However, what I think is the relevant section of the C99 standard is not so emphatic (though I don't know of an implementation where what I suggested is true is actually false):

§6.2.5 Types

¶26 A pointer to void shall have the same representation and alignment requirements as a pointer to a character type.39) Similarly, pointers to qualified or unqualified versions of compatible types shall have the same representation and alignment requirements. All pointers to structure types shall have the same representation and alignment requirements as each other. All pointers to union types shall have the same representation and alignment requirements as each other. Pointers to other types need not have the same representation or alignment requirements.

39) The same representation and alignment requirements are meant to imply interchangeability as arguments to functions, return values from functions, and members of unions.

(C11 says exactly the same in the section §6.2.5, ¶28, and footnote 48.)

So, all pointers to structures must be the same size as each other, and must share the same alignment requirements, even though the structures the pointers point at may have different alignment requirements. Similarly for unions. Character pointers and void pointers must have the same size and alignment requirements. Pointers to variations on int (meaning unsigned int and signed int) must have the same size and alignment requirements as each other; similarly for other types. But the C standard doesn't formally say that sizeof(int *) == sizeof(void *). Oh well, SO is good for making you inspect your assumptions.

The C standard definitively does not require function pointers to be the same size as object pointers. That was necessary not to break the different memory models on DOS-like systems. There you could have 16-bit data pointers but 32-bit function pointers, or vice versa. This is why the C standard does not mandate that function pointers can be converted to object pointers and vice versa.

Fortunately (for programmers targetting POSIX), POSIX steps into the breach and does mandate that function pointers and data pointers are the same size:

§2.12.3 Pointer Types

All function pointer types shall have the same representation as the type pointer to void. Conversion of a function pointer to void * shall not alter the representation. A void * value resulting from such a conversion can be converted back to the original function pointer type, using an explicit cast, without loss of information.

Note: The ISO C standard does not require this, but it is required for POSIX conformance.

So, it does seem that explicit casts to void * are strongly advisable for maximum reliability in the code when passing a pointer to a variadic function such as printf(). On POSIX systems, it is safe to cast a function pointer to a void pointer for printing. On other systems, it is not necessarily safe to do that, nor is it necessarily safe to pass pointers other than void * without a cast.

apache redirect from non www to www

This works for me:

RewriteCond %{HTTP_HOST} ^(?!www.domain.com).*$ [NC]
RewriteRule ^(.*)$  http://www.domain.com$1  [R=301,L]

I use the look-ahead pattern (?!www.domain.com) to exclude the www subdomain when redirecting all domains to the www subdomain in order to avoid an infinite redirect loop in Apache.

how does array[100] = {0} set the entire array to 0?

It depends where you put this initialisation.

If the array is static as in

char array[100] = {0};

int main(void)
{
...
}

then it is the compiler that reserves the 100 0 bytes in the data segement of the program. In this case you could have omitted the initialiser.

If your array is auto, then it is another story.

int foo(void)
{
char array[100] = {0};
...
}

In this case at every call of the function foo you will have a hidden memset.

The code above is equivalent to

int foo(void)
{ 
char array[100];

memset(array, 0, sizeof(array));
....
}

and if you omit the initializer your array will contain random data (the data of the stack).

If your local array is declared static like in

int foo(void)
{ 
static char array[100] = {0};
...
}

then it is technically the same case as the first one.

ToString() function in Go

Another example with a struct :

package types

import "fmt"

type MyType struct {
    Id   int    
    Name string
}

func (t MyType) String() string {
    return fmt.Sprintf(
    "[%d : %s]",
    t.Id, 
    t.Name)
}

Be careful when using it,
concatenation with '+' doesn't compile :

t := types.MyType{ 12, "Blabla" }

fmt.Println(t) // OK
fmt.Printf("t : %s \n", t) // OK
//fmt.Println("t : " + t) // Compiler error !!!
fmt.Println("t : " + t.String()) // OK if calling the function explicitly

How to hash some string with sha256 in Java?

private static String getMessageDigest(String message, String algorithm) {
 MessageDigest digest;
 try {
  digest = MessageDigest.getInstance(algorithm);
  byte data[] = digest.digest(message.getBytes("UTF-8"));
  return convertByteArrayToHexString(data);
 } catch (NoSuchAlgorithmException | UnsupportedEncodingException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
 }
 return null;
}

You can call above method with different algorithms like below.

getMessageDigest(message, "MD5");
getMessageDigest(message, "SHA-256");
getMessageDigest(message, "SHA-1");

You can refer this link for complete application.

Spring boot: Unable to start embedded Tomcat servlet container

You need to Tomcat Dependency and also extend your Application Class from extends SpringBootServletInitializer

@SpringBootApplication  
public class App extend SpringBootServletInitializer
{
    public static void main( String[] args )
    {
        SpringApplication.run(App.class, "hello");
    }
}

jQuery: How to capture the TAB keypress within a Textbox

An important part of using a key down on tab is knowing that tab will always try to do something already, don't forget to "return false" at the end.

Here is what I did. I have a function that runs on .blur and a function that swaps where my form focus is. Basically it adds an input to the end of the form and goes there while running calculations on blur.

$(this).children('input[type=text]').blur(timeEntered).keydown(function (e) {
        var code = e.keyCode || e.which;
        if (code == "9") {
            window.tabPressed = true;
            // Here is the external function you want to call, let your external
            // function handle all your custom code, then return false to
            // prevent the tab button from doing whatever it would naturally do.
            focusShift($(this));
            return false;
        } else {
            window.tabPressed = false;
        }
        // This is the code i want to execute, it might be different than yours
        function focusShift(trigger) {
            var focalPoint = false;
            if (tabPressed == true) {
                console.log($(trigger).parents("td").next("td"));
                focalPoint = $(trigger).parents("td").next("td");

            }
            if (focalPoint) {
                $(focalPoint).trigger("click");
            }
        }
    });

How can I find the number of arguments of a Python function?

inspect.getargspec()

Get the names and default values of a function’s arguments. A tuple of four things is returned: (args, varargs, varkw, defaults). args is a list of the argument names (it may contain nested lists). varargs and varkw are the names of the * and ** arguments or None. defaults is a tuple of default argument values or None if there are no default arguments; if this tuple has n elements, they correspond to the last n elements listed in args.

Changed in version 2.6: Returns a named tuple ArgSpec(args, varargs, keywords, defaults).

See can-you-list-the-keyword-arguments-a-python-function-receives.

Navigation drawer: How do I set the selected item at startup?

You have to call 2 functions for this:

First: for excuting the commands you have implemented in onNavigationItemSelected listener:

onNavigationItemSelected(navigationView.getMenu().getItem(R.id.nav_camera));

Second: for changing the state of the navigation drawer menu item to selected (or checked):

navigationView.setCheckedItem(R.id.nav_camera);

I called both functions and it worked for me.

How to use HTML Agility pack

try this

string htmlBody = ParseHmlBody(dtViewDetails.Rows[0]["Body"].ToString());

private string ParseHmlBody(string html)
        {
            string body = string.Empty;
            try
            {
                var htmlDoc = new HtmlDocument();
                htmlDoc.LoadHtml(html);
                var htmlBody = htmlDoc.DocumentNode.SelectSingleNode("//body");
                body = htmlBody.OuterHtml;
            }
            catch (Exception ex)
            {

                dalPendingOrders.LogMessage("Error in ParseHmlBody" + ex.Message);
            }
            return body;
        }

Deploy a project using Git push

I found this script on this site and it seems to work quite well.

  1. Copy over your .git directory to your web server
  2. On your local copy, modify your .git/config file and add your web server as a remote:

    [remote "production"]
        url = username@webserver:/path/to/htdocs/.git
    
  3. On the server, replace .git/hooks/post-update with this file (in the answer below)

  4. Add execute access to the file (again, on the server):

    chmod +x .git/hooks/post-update
    
  5. Now, just locally push to your web server and it should automatically update the working copy:

    git push production
    

changing source on html5 video tag

This is my solution:

<video id="playVideo" width="680" height="400" controls="controls">
    <source id="sourceVideo" src="{{video.videoHigh}}" type="video/mp4">
</video>
    <br />
<button class="btn btn-warning" id="{{video.videoHigh}}" onclick="changeSource(this)">HD</button>
<button class="btn btn-warning" id="{{video.videoLow}}" onclick="changeSource(this)">Regular</button>

<script type="text/javascript">
    var getVideo = document.getElementById("playVideo");
    var getSource = document.getElementById("sourceVideo");
    function changeSource(vid) {
        var geturl = vid.id;
        getSource .setAttribute("src", geturl);
        getVideo .load()
        getVideo .play();
        getVideo .volume = 0.5;
    }
</script>

Clear variable in python

  • If want to totally delete it use del:

    del your_variable
    
  • Or otherwise, to make the value None:

    your_variable = None
    
  • If it's a mutable iterable (lists, sets, dictionaries, etc, but not tuples because they're immutable), you can make it empty like:

    your_variable.clear()
    

Then your_variable will be empty

How to make a Python script run like a service or daemon in Linux

Assuming that you would really want your loop to run 24/7 as a background service

For a solution that doesn't involve injecting your code with libraries, you can simply create a service template, since you are using linux:

[Unit]
Description = <Your service description here>
After = network.target # Assuming you want to start after network interfaces are made available
 
[Service]
Type = simple
ExecStart = python <Path of the script you want to run>
User = # User to run the script as
Group = # Group to run the script as
Restart = on-failure # Restart when there are errors
SyslogIdentifier = <Name of logs for the service>
RestartSec = 5
TimeoutStartSec = infinity
 
[Install]
WantedBy = multi-user.target # Make it accessible to other users

Place that file in your daemon service folder (usually /etc/systemd/system/), in a *.service file, and install it using the following systemctl commands (will likely require sudo privileges):

systemctl enable <service file name without .service extension>

systemctl daemon-reload

systemctl start <service file name without .service extension>

You can then check that your service is running by using the command:

systemctl | grep running

How do I download and save a file locally on iOS using objective C?

NSURLSession introduced in iOS 7, is the recommended SDK way of downloading a file. No need to import 3rd party libraries.

NSURL *url = [NSURL URLWithString:@"http://www.something.com/file"];
NSURLRequest *downloadRequest = [NSURLRequest requestWithURL:url];
NSURLSessionConfiguration *sessionConfig = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *urlSession = [NSURLSession sessionWithConfiguration:sessionConfig delegate:self delegateQueue:nil];
self.downloadTask = [self.urlSession downloadTaskWithRequest:downloadRequest];
[self.downloadTask resume];

You can then use the NSURLSessionDownloadDelegate delegate methods to monitor errors, download completion, download progress etc... There are inline block completion handler callback methods too if you prefer. Apples docs explain when you need to use one over the other.

Have a read of these articles:

objc.io NSURLConnection to NSURLSession

URL Loading System Programming Guide

MySQL error - #1062 - Duplicate entry ' ' for key 2

Error 'Duplicate entry '338620-7' for key 2' on query. Default database

For this error :

set global sql_slave_skip_counter=1; 
start slave; 
show slave status\G

This worked for me

Initialise numpy array of unknown length

For posterity, I think this is quicker:

a = np.array([np.array(list()) for _ in y])

You might even be able to pass in a generator (i.e. [] -> ()), in which case the inner list is never fully stored in memory.


Responding to comment below:

>>> import numpy as np
>>> y = range(10)
>>> a = np.array([np.array(list) for _ in y])
>>> a
array([array(<type 'list'>, dtype=object),
       array(<type 'list'>, dtype=object),
       array(<type 'list'>, dtype=object),
       array(<type 'list'>, dtype=object),
       array(<type 'list'>, dtype=object),
       array(<type 'list'>, dtype=object),
       array(<type 'list'>, dtype=object),
       array(<type 'list'>, dtype=object),
       array(<type 'list'>, dtype=object),
       array(<type 'list'>, dtype=object)], dtype=object)

How do I build a graphical user interface in C++?

Since I've already been where you are right now, I think I can "answer" you.

The fact is there is no easy way to make a GUI. GUI's are highly dependent on platform and OS specific code, that's why you should start reading your target platform/OS documentation on window management APIs. The good thing is: there are plenty of libraries that address these limitations and abstract architecture differences into a single multi-platform API. Those suggested before, GTK and Qt, are some of these libraries.

But even these are a little too complicated, since lots of new concepts, data types, namespaces and classes are introduced, all at once. For this reason, they use to come bundled with some GUI WYSIWYG editor. They pretty much make programming software with GUIs possible.

To sum it up, there are also non free "environments" for GUI development such as Visual Studio from Microsoft. For those with Delphi experience backgrounds, Visual Studio may be more familiar. There are also free alternatives to the full Visual Studio environment supplied from Microsoft: Visual Studio Express, which is more than enough for starting on GUI development.

update to python 3.7 using anaconda

This can be installed via conda with the command conda install -c anaconda python=3.7 as per https://anaconda.org/anaconda/python.

Though not all packages support 3.7 yet, running conda update --all may resolve some dependency failures.

How to discard local commits in Git?

You need to run

git fetch

To get all changes and then you will not receive message with "your branch is ahead".

How do you migrate an IIS 7 site to another server?

In my case, the files were already copied, I found the easiest way to follow the steps in this guide: https://www.ryadel.com/en/exporting-importing-app-pools-and-websites-configuration-between-multiple-iis-instances/

I exported AppPools/Websites, copied the xml files to the destination server and Imported AppPools then Websites. Worked very well. This is also another excellent option for this question.