Programs & Examples On #Diskspace

Issues relating to availability of disk space.

MacOS Xcode CoreSimulator folder very big. Is it ok to delete content?

That directory is part of your user data and you can delete any user data without affecting Xcode seriously. You can delete the whole CoreSimulator/ directory. Xcode will recreate fresh instances there for you when you do your next simulator run. If you can afford losing any previous simulator data of your apps this is the easy way to get space.

Update: A related useful app is "DevCleaner for Xcode" https://apps.apple.com/app/devcleaner-for-xcode/id1388020431

Get free disk space

Check this out (this is a working solution for me)

public long AvailableFreeSpace()
{
    long longAvailableFreeSpace = 0;
    try{
        DriveInfo[] arrayOfDrives = DriveInfo.GetDrives();
        foreach (var d in arrayOfDrives)
        {
            Console.WriteLine("Drive {0}", d.Name);
            Console.WriteLine("  Drive type: {0}", d.DriveType);
            if (d.IsReady == true && d.Name == "/data")
            {
                Console.WriteLine("Volume label: {0}", d.VolumeLabel);
                Console.WriteLine("File system: {0}", d.DriveFormat);
                Console.WriteLine("AvailableFreeSpace for current user:{0, 15} bytes",d.AvailableFreeSpace);
                Console.WriteLine("TotalFreeSpace {0, 15} bytes",d.TotalFreeSpace);
                Console.WriteLine("Total size of drive: {0, 15} bytes \n",d.TotalSize);
                }
                longAvailableFreeSpaceInMB = d.TotalFreeSpace;
        }
    }
    catch(Exception ex){
        ServiceLocator.GetInsightsProvider()?.LogError(ex);
    }
    return longAvailableFreeSpace;
}

Find size and free space of the filesystem containing a given file

import os

def disk_stat(path):
    disk = os.statvfs(path)
    percent = (disk.f_blocks - disk.f_bfree) * 100 / (disk.f_blocks -disk.f_bfree + disk.f_bavail) + 1
    return percent


print disk_stat('/')
print disk_stat('/data')

What is the unix command to see how much disk space there is and how much is remaining?

I love doing du -sh * | sort -nr | less to sort by the largest files first

How do I monitor the computer's CPU, memory, and disk usage in Java?

In JDK 1.7, you can get system CPU and memory usage via com.sun.management.OperatingSystemMXBean. This is different than java.lang.management.OperatingSystemMXBean.

long    getCommittedVirtualMemorySize()
Returns the amount of virtual memory that is guaranteed to be available to the running process in bytes, or -1 if this operation is not supported.

long    getFreePhysicalMemorySize()
Returns the amount of free physical memory in bytes.

long    getFreeSwapSpaceSize()
Returns the amount of free swap space in bytes.

double  getProcessCpuLoad()
Returns the "recent cpu usage" for the Java Virtual Machine process.

long    getProcessCpuTime()
Returns the CPU time used by the process on which the Java virtual machine is running in nanoseconds.

double  getSystemCpuLoad()
Returns the "recent cpu usage" for the whole system.

long    getTotalPhysicalMemorySize()
Returns the total amount of physical memory in bytes.

long    getTotalSwapSpaceSize()
Returns the total amount of swap space in bytes.

Android SDK folder taking a lot of disk space. Do we need to keep all of the System Images?

In this folder there are all emulator images. If you don't use emulator then you can delete this folder.

Saving a Numpy array as an image

The world probably doesn't need yet another package for writing a numpy array to a PNG file, but for those who can't get enough, I recently put up numpngw on github:

https://github.com/WarrenWeckesser/numpngw

and on pypi: https://pypi.python.org/pypi/numpngw/

The only external dependency is numpy.

Here's the first example from the examples directory of the repository. The essential line is simply

write_png('example1.png', img)

where img is a numpy array. All the code before that line is import statements and code to create img.

import numpy as np
from numpngw import write_png


# Example 1
#
# Create an 8-bit RGB image.

img = np.zeros((80, 128, 3), dtype=np.uint8)

grad = np.linspace(0, 255, img.shape[1])

img[:16, :, :] = 127
img[16:32, :, 0] = grad
img[32:48, :, 1] = grad[::-1]
img[48:64, :, 2] = grad
img[64:, :, :] = 127

write_png('example1.png', img)

Here's the PNG file that it creates:

example1.png

How to color System.out.println output?

System.err.println("Errorrrrrr") it will print text in Red color on console.

Change status bar text color to light in iOS 9 with Objective-C

  1. Add a key in your info.plist file UIViewControllerBasedStatusBarAppearance and set it to YES.

  2. In viewDidLoad method of your ViewController add a method call:

    [self setNeedsStatusBarAppearanceUpdate];
    
  3. Then paste the following method in viewController file:

    - (UIStatusBarStyle)preferredStatusBarStyle
    { 
        return UIStatusBarStyleLightContent; 
    }
    

Creating default object from empty value in PHP?

no you do not .. it will create it when you add the success value to the object.the default class is inherited if you do not specify one.

python: how to send mail with TO, CC and BCC?

Don't add the bcc header.

See this: http://mail.python.org/pipermail/email-sig/2004-September/000151.html

And this: """Notice that the second argument to sendmail(), the recipients, is passed as a list. You can include any number of addresses in the list to have the message delivered to each of them in turn. Since the envelope information is separate from the message headers, you can even BCC someone by including them in the method argument but not in the message header.""" from http://pymotw.com/2/smtplib

toaddr = '[email protected]'
cc = ['[email protected]','[email protected]']
bcc = ['[email protected]']
fromaddr = '[email protected]'
message_subject = "disturbance in sector 7"
message_text = "Three are dead in an attack in the sewers below sector 7."
message = "From: %s\r\n" % fromaddr
    + "To: %s\r\n" % toaddr
    + "CC: %s\r\n" % ",".join(cc)
    # don't add this, otherwise "to and cc" receivers will know who are the bcc receivers
    # + "BCC: %s\r\n" % ",".join(bcc)
    + "Subject: %s\r\n" % message_subject
    + "\r\n" 
    + message_text
toaddrs = [toaddr] + cc + bcc
server = smtplib.SMTP('smtp.sunnydale.k12.ca.us')
server.set_debuglevel(1)
server.sendmail(fromaddr, toaddrs, message)
server.quit()

no operator "<<" matches these operands

You're not including the standard <string> header.

You got [un]lucky that some of its pertinent definitions were accidentally made available by the other standard headers that you did include ... but operator<< was not.

Missing include "bits/c++config.h" when cross compiling 64 bit program on 32 bit in Ubuntu

Seems to be a typo error in that package of gcc. The solution:

mv /usr/include/c++/4.x/i486-linux-gnu /usr/include/c++/4.x/i686-linux-gnu/64

ParseError: not well-formed (invalid token) using cElementTree

I have been in stuck with similar problem. Finally figured out the what was the root cause in my particular case. If you read the data from multiple XML files that lie in same folder you will parse also .DS_Store file. Before parsing add this condition

for file in files:
    if file.endswith('.xml'):
       run_your_code...

This trick helped me as well

SELECT INTO a table variable in T-SQL

One reason to use SELECT INTO is that it allows you to use IDENTITY:

SELECT IDENTITY(INT,1,1) AS Id, name
INTO #MyTable 
FROM (SELECT name FROM AnotherTable) AS t

This would not work with a table variable, which is too bad...

What is the apply function in Scala?

It comes from the idea that you often want to apply something to an object. The more accurate example is the one of factories. When you have a factory, you want to apply parameter to it to create an object.

Scala guys thought that, as it occurs in many situation, it could be nice to have a shortcut to call apply. Thus when you give parameters directly to an object, it's desugared as if you pass these parameters to the apply function of that object:

class MyAdder(x: Int) {
  def apply(y: Int) = x + y
}

val adder = new MyAdder(2)
val result = adder(4) // equivalent to x.apply(4)

It's often use in companion object, to provide a nice factory method for a class or a trait, here is an example:

trait A {
  val x: Int
  def myComplexStrategy: Int
}

object A {
  def apply(x: Int): A = new MyA(x)

  private class MyA(val x: Int) extends A {
    val myComplexStrategy = 42
  }
}

From the scala standard library, you might look at how scala.collection.Seq is implemented: Seq is a trait, thus new Seq(1, 2) won't compile but thanks to companion object and apply, you can call Seq(1, 2) and the implementation is chosen by the companion object.

How to create a file name with the current date & time in Python?

Here's some that I needed to include the date-time stamp in the folder name for dumping files from a web scraper.

# import time and OS modules to use to build file folder name
import time
import os 

# Build string for directory to hold files
# Output Configuration
#   drive_letter = Output device location (hard drive) 
#   folder_name = directory (folder) to receive and store PDF files

drive_letter = r'D:\\' 
folder_name = r'downloaded-files'
folder_time = datetime.now().strftime("%Y-%m-%d_%I-%M-%S_%p")
folder_to_save_files = drive_letter + folder_name + folder_time 

# IF no such folder exists, create one automatically
if not os.path.exists(folder_to_save_files):
    os.mkdir(folder_to_save_files)

What is the difference between == and equals() in Java?

You will have to override the equals function (along with others) to use this with custom classes.

The equals method compares the objects.

The == binary operator compares memory addresses.

Android: remove notification from notification bar

NotificationManager.cancel(id) is the correct answer. Yet you can remove in Android Oreo and later notifications by deleting the whole notification channel. This should delete all messages in the deleted channel.

Here is the example from the Android documentation:

NotificationManager mNotificationManager =
        (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
// The id of the channel.
String id = "my_channel_01";
mNotificationManager.deleteNotificationChannel(id);

How can I find the link URL by link text with XPath?

Think of the phrase in the square brackets as a WHERE clause in SQL.

So this query says, "select the "href" attribute (@) of an "a" tag that appears anywhere (//), but only where (the bracketed phrase) the textual contents of the "a" tag is equal to 'programming questions site'".

Failure [INSTALL_FAILED_INVALID_APK]

I have recently had this problem building a multi-module, multi-apk application. As it turns out, my top level gradle build was modifying the android:versionCode, and that was making it out of sync with the manifests in the dynamic feature modules. This took me hours to find the cause, and only minutes to solve.

I found that the android studio log itself,

idea.log

, tells me way more about the problem than the IDE did.

2020-02-05 22:52:56,206 [thread 246]   WARN -            #com.android.ddmlib - Failed to commit install session 986623974 with command cmd package install-commit 986623974. Error: INSTALL_FAILED_INVALID_APK: /data/app/vmdl986623974.tmp/1_mytestapp-afat-debug version code 1829 inconsistent with 18290 
2020-02-05 22:52:56,206 [thread 246]   WARN - a.run.tasks.AbstractDeployTask - Install failed: The application could not be installed: INSTALL_FAILED_INVALID_APK The APKs are invalid. 

Can a foreign key refer to a primary key in the same table?

Sure, why not? Let's say you have a Person table, with id, name, age, and parent_id, where parent_id is a foreign key to the same table. You wouldn't need to normalize the Person table to Parent and Child tables, that would be overkill.

Person
| id |  name | age | parent_id |
|----|-------|-----|-----------|
|  1 |   Tom |  50 |      null |
|  2 | Billy |  15 |         1 |

Something like this.

I suppose to maintain consistency, there would need to be at least 1 null value for parent_id, though. The one "alpha male" row.

EDIT: As the comments show, Sam found a good reason not to do this. It seems that in MySQL when you attempt to make edits to the primary key, even if you specify CASCADE ON UPDATE it won’t propagate the edit properly. Although primary keys are (usually) off-limits to editing in production, it is nevertheless a limitation not to be ignored. Thus I change my answer to:- you should probably avoid this practice unless you have pretty tight control over the production system (and can guarantee no one will implement a control that edits the PKs). I haven't tested it outside of MySQL.

What is the common header format of Python files?

I strongly favour minimal file headers, by which I mean just:

  • The hashbang (#! line) if this is an executable script
  • Module docstring
  • Imports, grouped in the standard way, eg:
  import os    # standard library
  import sys

  import requests  # 3rd party packages

  from mypackage import (  # local source
      mymodule,
      myothermodule,
  )

ie. three groups of imports, with a single blank line between them. Within each group, imports are sorted. The final group, imports from local source, can either be absolute imports as shown, or explicit relative imports.

Everything else is a waste of time, visual space, and is actively misleading.

If you have legal disclaimers or licencing info, it goes into a separate file. It does not need to infect every source code file. Your copyright should be part of this. People should be able to find it in your LICENSE file, not random source code.

Metadata such as authorship and dates is already maintained by your source control. There is no need to add a less-detailed, erroneous, and out-of-date version of the same info in the file itself.

I don't believe there is any other data that everyone needs to put into all their source files. You may have some particular requirement to do so, but such things apply, by definition, only to you. They have no place in “general headers recommended for everyone”.

How can I get the nth character of a string?

char* str = "HELLO";
char c = str[1];

Keep in mind that arrays and strings in C begin indexing at 0 rather than 1, so "H" is str[0], "E" is str[1], the first "L" is str[2] and so on.

error CS0234: The type or namespace name 'Script' does not exist in the namespace 'System.Web'

Since JsonSerializer is deprecated in .Net 4.0+ I used http://www.newtonsoft.com/json to solve this issue.

NuGet- > Install-Package Newtonsoft.Json

Importing data from a JSON file into R

An alternative package is RJSONIO. To convert a nested list, lapply can help:

l <- fromJSON('[{"winner":"68694999",  "votes":[ 
   {"ts":"Thu Mar 25 03:13:01 UTC 2010", "user":{"name":"Lamur","user_id":"68694999"}},   
   {"ts":"Thu Mar 25 03:13:08 UTC 2010", "user":{"name":"Lamur","user_id":"68694999"}}],   
  "lastVote":{"timestamp":1269486788526,"user":
   {"name":"Lamur","user_id":"68694999"}},"startPrice":0}]'
)
m <- lapply(
    l[[1]]$votes, 
    function(x) c(x$user['name'], x$user['user_id'], x['ts'])
)
m <- do.call(rbind, m)

gives information on the votes in your example.

How to draw a checkmark / tick using CSS?

i like this way because you don't need to create two components just one.

.checkmark:after {
    opacity: 1;
    height: 4em;
    width: 2em;
    -webkit-transform-origin: left top;
    transform-origin: left top;
    border-right: 2px solid #5cb85c;
    border-top: 2px solid #5cb85c;
    content: '';
    left: 2em;
    top: 4em;
    position: absolute;
}

Animation from Scott Galloway Pen

How do you discover model attributes in Rails?

To describe model I use following snippet

Model.columns.collect { |c| "#{c.name} (#{c.type})" }

Again this is if you are looking pretty print to describe you ActiveRecord without you going trough migrations or hopping that developer before you was nice enough to comment in attributes.

Does mobile Google Chrome support browser extensions?

Some extensions like blocksite use the accessibility service API to deploy extension like features to Chrome on Android. Might be worth a look through the play store. Otherwise, Firefox is your best bet, though many extensions don't work on mobile for some reason.

https://play.google.com/store/apps/details?id=co.blocksite&hl=en_US

How to Execute SQL Script File in Java?

For my simple project the user should be able to select SQL-files which get executed. As I was not happy with the other answers and I am using Flyway anyway I took a closer look at the Flyway code. DefaultSqlScriptExecutor is doing the actual execution, so I tried to figure out how to create an instance of DefaultSqlScriptExecutor.

Basically the following snippet loads a String splits it into the single statements and executes one by one. Flyway also provides other LoadableResources than StringResource e.g. FileSystemResource. But I have not taken a closer look at them.

As DefaultSqlScriptExecutor and the other classes are not officially documented by Flyway use the code-snippet with care.

public static void execSqlQueries(String sqlQueries, Configuration flyWayConf) throws SQLException {
  // create dependencies FlyWay needs to execute the SQL queries
  JdbcConnectionFactory jdbcConnectionFactory = new JdbcConnectionFactory(flyWayConf.getDataSource(),
      flyWayConf.getConnectRetries(),
      null);
  DatabaseType databaseType = jdbcConnectionFactory.getDatabaseType();
  ParsingContext parsingContext = new ParsingContext();
  SqlScriptFactory sqlScriptFactory = databaseType.createSqlScriptFactory(flyWayConf, parsingContext);
  Connection conn = flyWayConf.getDataSource().getConnection();
  JdbcTemplate jdbcTemp = new JdbcTemplate(conn);
  ResourceProvider resProv = flyWayConf.getResourceProvider();
  DefaultSqlScriptExecutor scriptExec = new DefaultSqlScriptExecutor(jdbcTemp, null, false, false, false, null);
  
  // Prepare and execute the actual queries
  StringResource sqlRes = new StringResource(sqlQueries);
  SqlScript sqlScript = sqlScriptFactory.createSqlScript(sqlRes, true, resProv);
  scriptExec.execute(sqlScript);
}

background: fixed no repeat not working on mobile

I have been busy using different posts and methods for two days trying to figure it out. I urge anyone to START by looking at the post by Eggs, and mess around with the codepen he and others have built.

This has been the only solution to work properly for me that I have found. I recommend his answer as a solution/ a good starting point at minimum for those of us still figuring out this problem in our own web applications.

I haven't gotten enough reputation yet to comment on his post, otherwise I would. I can't even vote on it yet or I would do that too.

This is the actual code I used:

html::before {
    content: ' ';
    display: block;
    background-image: url('path-to-your-image');
    background-position: bottom left; 
    /*For my instance this is how I have built my bg image. Indexes off the 
bottom left for consistency*/
    background-size: cover;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    position: fixed;
    z-index: -10; 
    /*I haven't tested my full app functionality after changing the z-index, but everything appears to work flawlessly right now.*/
}

I tried everything with his original code. When I had

background-position: center; 

chrome (on latest android update as of 1/8/18) would lag with updating the image's position, so when scrolling through the website there would be a patch of color where my navbar/URL bar of the browser was. Then it would disappear after the browser recalculated the image center(is what I assume was happening).

So, I recommend making an image around your footer or header like I did, and setting either top left/right or bottom left/right for your position.

In summary, THIS WORKS for me. So try it out if you're reading down this far and nothing has worked yet. Though you should've already hit the original post by now.

Thank you Eggs, and the other fellows you collaborated with on your Codepen.

How do you round UP a number in Python?

I'm surprised I haven't seen this answer yet round(x + 0.4999), so I'm going to put it down. Note that this works with any Python version. Changes made to the Python rounding scheme has made things difficult. See this post.

Without importing, I use:

def roundUp(num):
    return round(num + 0.49)

testCases = list(x*0.1 for x in range(0, 50))

print(testCases)
for test in testCases:
    print("{:5.2f}  -> {:5.2f}".format(test, roundUp(test)))

Why this works

From the docs

For the built-in types supporting round(), values are rounded to the closest multiple of 10 to the power minus n; if two multiples are equally close, rounding is done toward the even choice

Therefore 2.5 gets rounded to 2 and 3.5 gets rounded to 4. If this was not the case then rounding up could be done by adding 0.5, but we want to avoid getting to the halfway point. So, if you add 0.4999 you will get close, but with enough margin to be rounded to what you would normally expect. Of course, this will fail if the x + 0.4999 is equal to [n].5000, but that is unlikely.

Switch android x86 screen resolution

In VirtualBox you should add custom resolution via the command:

VBoxManage setextradata "VM name" "CustomVideoMode1" "800x480x16"

instead of editing a .vbox file.

This solution works fine for me!

Using Vim's tabs like buffers

If you want buffers to work like tabs, check out the tabline plugin.

That uses a single window, and adds a line on the top to simulate the tabs (just showing the list of buffers). This came out a long time ago when tabs were only supported in GVim but not in the command line vim. Since it is only operating with buffers, everything integrates well with the rest of vim.

Can I get the name of the current controller in the view?

controller_name holds the name of the controller used to serve the current view.

Java: get all variable names in a class

You can use any of the two based on your need:

Field[] fields = ClassName.class.getFields(); // returns inherited members but not private members.
Field[] fields = ClassName.class.getDeclaredFields(); // returns all members including private members but not inherited members.

To filter only the public fields from the above list (based on requirement) use below code:

List<Field> fieldList = Arrays.asList(fields).stream().filter(field -> Modifier.isPublic(field.getModifiers())).collect(
    Collectors.toList());

Assigning more than one class for one event

It's like this:

$('.tag.clickedTag').click(function (){ 
 // this will catch with two classes
}

$('.tag.clickedTag.otherclass').click(function (){ 
 // this will catch with three classes
}

$('.tag:not(.clickedTag)').click(function (){ 
 // this will catch tag without clickedTag
}

How to read large text file on windows?

The integrated Text-Viewer of Total Commander can open huge files (>10GB) for viewing without any problems. It also provides different views, e.g. a Hex-View.

Trying to detect browser close event

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />


<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.min.js"></script>

<script type="text/javascript" language="javascript">

var validNavigation = false;

function endSession() {
// Browser or broswer tab is closed
// Do sth here ...
alert("bye");
}

function wireUpEvents() {
/*
* For a list of events that triggers onbeforeunload on IE
* check http://msdn.microsoft.com/en-us/library/ms536907(VS.85).aspx
*/
window.onbeforeunload = function() {
  if (!validNavigation) {

            var ref="load";
      $.ajax({
            type: 'get',
            async: false,
            url: 'logout.php',
 data:
            {
                ref:ref               
            },
             success:function(data)
            {
                console.log(data);
            }
            });
     endSession();
  }
 }

// Attach the event keypress to exclude the F5 refresh
$(document).bind('keypress', function(e) {
if (e.keyCode == 116){
  validNavigation = true;
}
});

// Attach the event click for all links in the page
$("a").bind("click", function() {
validNavigation = true;
});

 // Attach the event submit for all forms in the page
 $("form").bind("submit", function() {
 validNavigation = true;
 });

 // Attach the event click for all inputs in the page
 $("input[type=submit]").bind("click", function() {
 validNavigation = true;
 });

}

// Wire up the events as soon as the DOM tree is ready
$(document).ready(function() {
wireUpEvents();  
}); 
</script> 

This is used for when logged in user close the browser or browser tab it will automatically logout the user account...

How are iloc and loc different?

  • DataFrame.loc() : Select rows by index value
  • DataFrame.iloc() : Select rows by rows number

example :

  1. Select first 5 rows of a table, df1 is your dataframe

df1.iloc[:5]

  1. Select first A, B rows of a table, df1 is your dataframe

df1.loc['A','B']

Is it possible to opt-out of dark mode on iOS 13?

If you are not using Xcode 11 or later (i,e iOS 13 or later SDK), your app has not automatically opted to support dark mode. So, there's no need to opt out of dark mode.

If you are using Xcode 11 or later, the system has automatically enabled dark mode for your app. There are two approaches to disable dark mode depending on your preference. You can disable it entirely or disable it for any specific window, view, or view controller.

Disable Dark Mode Entirely for your App

You can disable dark mode by including the UIUserInterfaceStyle key with a value as Light in your app’s Info.plist file.
UIUserInterfaceStyle as Light
This ignores the user's preference and always applies a light appearance to your app.

Disable dark mode for Window, View, or View Controller

You can force your interface to always appear in a light or dark style by setting the overrideUserInterfaceStyle property of the appropriate window, view, or view controller.

View controllers:

override func viewDidLoad() {
    super.viewDidLoad()
    /* view controller’s views and child view controllers 
     always adopt a light interface style. */
    overrideUserInterfaceStyle = .light
}

Views:

// The view and all of its subviews always adopt light style.
youView.overrideUserInterfaceStyle = .light

Window:

/* Everything in the window adopts the style, 
 including the root view controller and all presentation controllers that 
 display content in that window.*/
window.overrideUserInterfaceStyle = .light

Note: Apple strongly encourages to support dark mode in your app. So, you can only disable dark mode temporarily.

Read more here: Choosing a Specific Interface Style for Your iOS App

IE8 css selector

2013 update: IE10+ no longer supports conditional comments.

Original answer:

Some people seem to be confused because this does not answer the letter of the question, only the spirit - so for clarification:

There is no such thing as a browser selector. There are hacks that take advantage of bugs and/or glitches in specific browsers' CSS parsers, but relying on these are setting yourself up for failure. There is a standard, accepted way to deal with this:

Use conditional comments to target IE only.

Example:

<!--[if gte IE 8]>
<style>
(your style here)
</style>
<![endif]-->

Everything inside the two <!--> will be ignored by all non-IE browsers as a comment, and IE versions that are less than IE8 will skip it. Only IE8 and greater will process it. 2013 update: IE10+ will also ignore it as a comment.

How to change an application icon programmatically in Android?

Applying the suggestions mentioned, I've faced the issue of app getting killed whenever default icon gets changed to new icon. So have implemented the code with some tweaks. Step 1). In file AndroidManifest.xml, create for default activity with android:enabled="true" & other alias with android:enabled="false". Your will not contain but append those in with android:enabled="true".

       <activity
        android:name=".activities.SplashActivity"
        android:label="@string/app_name"
        android:screenOrientation="portrait"
        android:theme="@style/SplashTheme">

    </activity>
    <!-- <activity-alias used to change app icon dynamically>   : default icon, set enabled true    -->
    <activity-alias
        android:label="@string/app_name"
        android:icon="@mipmap/ic_launcher"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:name=".SplashActivityAlias1" <!--put any random name started with dot-->
        android:enabled="true"
        android:targetActivity=".activities.SplashActivity"> <!--target activity class path will be same for all alias-->
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.DEFAULT" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity-alias>
    <!-- <activity-alias used to change app icon dynamically>  : sale icon, set enabled false initially -->
    <activity-alias
        android:label="@string/app_name"
        android:icon="@drawable/ic_store_marker"
        android:roundIcon="@drawable/ic_store_marker"
        android:name=".SplashActivityAlias" <!--put any random name started with dot-->
        android:enabled="false"
        android:targetActivity=".activities.SplashActivity"> <!--target activity class path will be same for all alias-->
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.DEFAULT" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity-alias>

Step 2). Make a method that will be used to disable 1st activity-alias that contains default icon & enable 2nd alias that contains icon need to be changed.

/**
 * method to change the app icon dynamically
 *
 * @param context
 * @param isNewIcon  : true if new icon need to be set; false to set default 
 * icon
 */

public static void changeAppIconDynamically(Context context, boolean isNewIcon) {
    PackageManager pm = context.getApplicationContext().getPackageManager();
    if (isNewIcon) {
        pm.setComponentEnabledSetting(
                new ComponentName(context,
                        "com.example.dummy.SplashActivityAlias1"), //com.example.dummy will be your package
                PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
                PackageManager.DONT_KILL_APP);

        pm.setComponentEnabledSetting(
                new ComponentName(context,
                        "com.example.dummy.SplashActivityAlias"),
                PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
                PackageManager.DONT_KILL_APP);
    } else {
        pm.setComponentEnabledSetting(
                new ComponentName(context,
                        "com.example.dummy.SplashActivityAlias1"),
                PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
                PackageManager.DONT_KILL_APP);

        pm.setComponentEnabledSetting(
                new ComponentName(context,
                        "com.example.dummy.SplashActivityAlias"),
                PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
                PackageManager.DONT_KILL_APP);
    }
}

Step 3). Now call this method depending on your requirement, say on button click or date specific or occasion specific conditions, simply like -

// Switch app icon to new icon
    GeneralUtils.changeAppIconDynamically(EditProfileActivity.this, true);
// Switch app icon to default icon
            GeneralUtils.changeAppIconDynamically(EditProfileActivity.this, false);

Hope this will help those who face the issue of app getting killed on icon change. Happy Coding :)

how to display excel sheet in html page

You can upload it into Google Docs, and embed the Google Spreadsheet as detailed here: http://support.google.com/docs/bin/answer.py?hl=en&answer=55244

Set an environment variable in git bash

A normal variable is set by simply assigning it a value; note that no whitespace is allowed around the =:

HOME=c

An environment variable is a regular variable that has been marked for export to the environment.

export HOME
HOME=c

You can combine the assignment with the export statement.

export HOME=c

How do I run a terminal inside of Vim?

If enabled in your version of Vim, a terminal can be started with the :term command.

Terminal window support was added to Vim 8. It is an optional feature that can be enabled when compiling Vim with the +terminal feature. If your version of Vim has terminal support, :echo has('terminal') will output "1".

Entering :term will place you in Terminal-Job mode, where you can use the terminal as expected.

Within Terminal-Job mode, pressing Ctrl-W N or Ctrl-\ Ctrl-N switches the mode to Terminal-Normal, which allows the cursor to be moved and commands to be ran similarly to Vim's Normal mode. To switch back to Terminal-Job mode, press i.

Other answers mention similar functionality in Neovim.

Is log(n!) = T(n·log(n))?

See Stirling's Approximation:

ln(n!) = n*ln(n) - n + O(ln(n))

where the last 2 terms are less significant than the first one.

Fix height of a table row in HTML Table

my css

TR.gray-t {background:#949494;}
h3{
    padding-top:3px;
    font:bold 12px/2px Arial;
}

my html

<TR class='gray-t'>
<TD colspan='3'><h3>KAJANG</h3>

I decrease the 2nd size in font.

padding-top is used to fix the size in IE7.

Is there a function to copy an array in C/C++?

Just include the standard library in your code.

#include<algorithm>

Array size will be denoted as n

Your old Array

int oldArray[n]={10,20,30,40,50};

Declare New Array in which you have to copy your old array value

int newArray[n];

Use this

copy_n(oldArray,n,newArray);

Why std::cout instead of simply cout?

"std" is a namespace used for STL (Standard Template Library). Please refer to https://en.wikipedia.org/wiki/Namespace#Use_in_common_languages

You can either write using namespace std; before using any stl functions, variables or just insert std:: before them.

Initializing array of structures

It's a designated initializer, introduced with the C99 standard; it allows you to initialize specific members of a struct or union object by name. my_data is obviously a typedef for a struct type that has a member name of type char * or char [N].

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)'

How to recover the deleted files using "rm -R" command in linux server?

Not possible with standard unix commands. You might have luck with a file recovery utility. Also, be aware, using rm changes the table of contents to mark those blocks as available to be overwritten, so simply using your computer right now risks those blocks being overwritten permanently. If it's critical data, you should turn off the computer before the file sectors gets overwritten. Good luck!

Some restore utility: http://www.ubuntugeek.com/recover-deleted-files-with-foremostscalpel-in-ubuntu.html

Forum where this was previously answered: http://webcache.googleusercontent.com/search?q=cache:m4hiPw-_GekJ:ubuntuforums.org/archive/index.php/t-1134955.html+&cd=1&hl=en&ct=clnk&gl=us

Converting between strings and ArrayBuffers

In case you have binary data in a string (obtained from nodejs + readFile(..., 'binary'), or cypress + cy.fixture(..., 'binary'), etc), you can't use TextEncoder. It supports only utf8. Bytes with values >= 128 are each turned into 2 bytes.

ES2015:

a = Uint8Array.from(s, x => x.charCodeAt(0))

Uint8Array(33) [2, 134, 140, 186, 82, 70, 108, 182, 233, 40, 143, 247, 29, 76, 245, 206, 29, 87, 48, 160, 78, 225, 242, 56, 236, 201, 80, 80, 152, 118, 92, 144, 48

s = String.fromCharCode.apply(null, a)

"ºRFl¶é(÷LõÎW0 Náò8ìÉPPv\0"

List files in local git repo?

git ls-tree --full-tree -r HEAD and git ls-files return all files at once. For a large project with hundreds or thousands of files, and if you are interested in a particular file/directory, you may find more convenient to explore specific directories. You can do it by obtaining the ID/SHA-1 of the directory that you want to explore and then use git cat-file -p [ID/SHA-1 of directory]. For example:

git cat-file -p 14032aabd85b43a058cfc7025dd4fa9dd325ea97
100644 blob b93a4953fff68df523aa7656497ee339d6026d64    glyphicons-halflings-regular.eot
100644 blob 94fb5490a2ed10b2c69a4a567a4fd2e4f706d841    glyphicons-halflings-regular.svg
100644 blob 1413fc609ab6f21774de0cb7e01360095584f65b    glyphicons-halflings-regular.ttf
100644 blob 9e612858f802245ddcbf59788a0db942224bab35    glyphicons-halflings-regular.woff
100644 blob 64539b54c3751a6d9adb44c8e3a45ba5a73b77f0    glyphicons-halflings-regular.woff2

In the example above, 14032aabd85b43a058cfc7025dd4fa9dd325ea97 is the ID/SHA-1 of the directory that I wanted to explore. In this case, the result was that four files within that directory were being tracked by my Git repo. If the directory had additional files, it would mean those extra files were not being tracked. You can add files using git add <file>... of course.

joining two select statements

Not sure what you are trying to do, but you have two select clauses. Do this instead:

SELECT * 
FROM ( SELECT * 
       FROM orders_products 
       INNER JOIN orders ON orders_products.orders_id = orders.orders_id 
       WHERE products_id = 181) AS A
JOIN ( SELECT * 
       FROM orders_products 
       INNER JOIN orders ON orders_products.orders_id = orders.orders_id
       WHERE products_id = 180) AS B

ON A.orders_id=B.orders_id

Update:

You could probably reduce it to something like this:

SELECT o.orders_id, 
       op1.products_id, 
       op1.quantity, 
       op2.products_id, 
       op2.quantity
FROM orders o
INNER JOIN orders_products op1 on o.orders_id = op1.orders_id  
INNER JOIN orders_products op2 on o.orders_id = op2.orders_id  
WHERE op1.products_id = 180
AND op2.products_id = 181

How do you add swap to an EC2 instance?

You can add a 1 GB swap to your instance with these commands:

sudo dd if=/dev/zero of=/swapfile bs=1M count=1024
sudo mkswap /swapfile
sudo swapon /swapfile

To enable it by default after reboot, add this line to /etc/fstab:

/swapfile swap swap defaults 0 0

return results from a function (javascript, nodejs)

function routeToRoom(userId, passw, cb) {
    var roomId = 0;
    var nStore = require('nstore/lib/nstore').extend(require('nstore/lib/nstore/query')());
    var users = nStore.new('data/users.db', function() {
        users.find({
            user: userId,
            pass: passw
        }, function(err, results) {
            if (err) {
                roomId = -1;
            } else {
                roomId = results.creationix.room;
            }
            cb(roomId);
        });
    });
}
routeToRoom("alex", "123", function(id) {
    console.log(id);    
});

You need to use callbacks. That's how asynchronous IO works. Btw sys.puts is deprecated

Convert pandas DataFrame into list of lists

There is a built in method which would be the fastest method also, calling tolist on the .values np array:

df.values.tolist()

[[0.0, 3.61, 380.0, 3.0],
 [1.0, 3.67, 660.0, 3.0],
 [1.0, 3.19, 640.0, 4.0],
 [0.0, 2.93, 520.0, 4.0]]

Hour from DateTime? in 24 hours format

Try this:

//String.Format("{0:HH:mm}", dt);  // where dt is a DateTime variable

public static string FormatearHoraA24(DateTime? fechaHora)
{
    if (!fechaHora.HasValue)
        return "";

    return retornar = String.Format("{0:HH:mm}", (DateTime)fechaHora);
}

Equivalent of jQuery .hide() to set visibility: hidden

If you only need the standard functionality of hide only with visibility:hidden to keep the current layout you can use the callback function of hide to alter the css in the tag. Hide docs in jquery

An example :

$('#subs_selection_box').fadeOut('slow', function() {
      $(this).css({"visibility":"hidden"});
      $(this).css({"display":"block"});
});

This will use the normal cool animation to hide the div, but after the animation finish you set the visibility to hidden and display to block.

An example : http://jsfiddle.net/bTkKG/1/

I know you didnt want the $("#aa").css() solution, but you did not specify if it was because using only the css() method you lose the animation.

Boxplot in R showing the mean

abline(h=mean(x))

for a horizontal line (use v instead of h for vertical if you orient your boxplot horizontally), or

points(mean(x))

for a point. Use the parameter pch to change the symbol. You may want to colour them to improve visibility too.

Note that these are called after you have drawn the boxplot.

If you are using the formula interface, you would have to construct the vector of means. For example, taking the first example from ?boxplot:

boxplot(count ~ spray, data = InsectSprays, col = "lightgray")
means <- tapply(InsectSprays$count,InsectSprays$spray,mean)
points(means,col="red",pch=18)

If your data contains missing values, you might want to replace the last argument of the tapply function with function(x) mean(x,na.rm=T)

App.Config change value

For a .NET 4.0 console application, none of these worked for me. So I modified Kevn Aenmey's answer as below and it worked:

private static void UpdateSetting(string key, string value)
{
    Configuration configuration = ConfigurationManager.
        OpenExeConfiguration(Assembly.GetExecutingAssembly().Location);
    configuration.AppSettings.Settings[key].Value = value;
    configuration.Save();

    ConfigurationManager.RefreshSection("appSettings");
}

Only the first line is different, constructed upon the actual executing assembly.

SQL Server using wildcard within IN

How about something like this?

declare @search table
(
    searchString varchar(10)
)

-- add whatever criteria you want...
insert into @search select '0711%' union select '0712%'

select j.*
from jobdetails j
    join @search s on j.job_no like s.searchString

Remove the newline character in a list read from a file

Here are various optimisations and applications of proper Python style to make your code a lot neater. I've put in some optional code using the csv module, which is more desirable than parsing it manually. I've also put in a bit of namedtuple goodness, but I don't use the attributes that then provides. Names of the parts of the namedtuple are inaccurate, you'll need to correct them.

import csv
from collections import namedtuple
from time import localtime, strftime

# Method one, reading the file into lists manually (less desirable)
with open('grades.dat') as files:
    grades = [[e.strip() for e in s.split(',')] for s in files]

# Method two, using csv and namedtuple
StudentRecord = namedtuple('StudentRecord', 'id, lastname, firstname, something, homework1, homework2, homework3, homework4, homework5, homework6, homework7, exam1, exam2, exam3')
grades = map(StudentRecord._make, csv.reader(open('grades.dat')))
# Now you could have student.id, student.lastname, etc.
# Skipping the namedtuple, you could do grades = map(tuple, csv.reader(open('grades.dat')))

request = open('requests.dat', 'w')
cont = 'y'

while cont.lower() == 'y':
    answer = raw_input('Please enter the Student I.D. of whom you are looking: ')
    for student in grades:
        if answer == student[0]:
            print '%s, %s      %s      %s' % (student[1], student[2], student[0], student[3])
            time = strftime('%a, %b %d %Y %H:%M:%S', localtime())
            print time
            print 'Exams - %s, %s, %s' % student[11:14]
            print 'Homework - %s, %s, %s, %s, %s, %s, %s' % student[4:11]
            total = sum(int(x) for x in student[4:14])
            print 'Total points earned - %d' % total
            grade = total / 5.5
            if grade >= 90:
                letter = 'an A'
            elif grade >= 80:
                letter = 'a B'
            elif grade >= 70:
                letter = 'a C'
            elif grade >= 60:
                letter = 'a D'
            else:
                letter = 'an F'

            if letter = 'an A':
                print 'Grade: %s, that is equal to %s.' % (grade, letter)
            else:
                print 'Grade: %.2f, that is equal to %s.' % (grade, letter)

            request.write('%s %s, %s %s\n' % (student[0], student[1], student[2], time))


    print
    cont = raw_input('Would you like to search again? ')

print 'Goodbye.'

Get yesterday's date using Date

   Calendar cal = Calendar.getInstance();
   DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
   System.out.println("Today's date is "+dateFormat.format(cal.getTime()));

   cal.add(Calendar.DATE, -1);
   System.out.println("Yesterday's date was "+dateFormat.format(cal.getTime()));  

Use Calender Api

Unable to load script from assets index.android.bundle on windows

don't forget turn on internet in emulator device, I resovled this error, it work perfect :V I get this error because i turn off internet to test NetInfo :D

How to divide flask app into multiple py files?

This task can be accomplished without blueprints and tricky imports using Centralized URL Map

app.py

import views
from flask import Flask

app = Flask(__name__)

app.add_url_rule('/', view_func=views.index)
app.add_url_rule('/other', view_func=views.other)

if __name__ == '__main__':
    app.run(debug=True, use_reloader=True)

views.py

from flask import render_template

def index():
    return render_template('index.html')

def other():
    return render_template('other.html')

html5 localStorage error with Safari: "QUOTA_EXCEEDED_ERR: DOM Exception 22: An attempt was made to add something to storage that exceeded the quota."

I had the same problem using Ionic framework (Angular + Cordova). I know this not solve the problem, but it's the code for Angular Apps based on the answers above. You will have a ephemeral solution for localStorage on iOS version of Safari.

Here is the code:

angular.module('myApp.factories', [])
.factory('$fakeStorage', [
    function(){
        function FakeStorage() {};
        FakeStorage.prototype.setItem = function (key, value) {
            this[key] = value;
        };
        FakeStorage.prototype.getItem = function (key) {
            return typeof this[key] == 'undefined' ? null : this[key];
        }
        FakeStorage.prototype.removeItem = function (key) {
            this[key] = undefined;
        };
        FakeStorage.prototype.clear = function(){
            for (var key in this) {
                if( this.hasOwnProperty(key) )
                {
                    this.removeItem(key);
                }
            }
        };
        FakeStorage.prototype.key = function(index){
            return Object.keys(this)[index];
        };
        return new FakeStorage();
    }
])
.factory('$localstorage', [
    '$window', '$fakeStorage',
    function($window, $fakeStorage) {
        function isStorageSupported(storageName) 
        {
            var testKey = 'test',
                storage = $window[storageName];
            try
            {
                storage.setItem(testKey, '1');
                storage.removeItem(testKey);
                return true;
            } 
            catch (error) 
            {
                return false;
            }
        }
        var storage = isStorageSupported('localStorage') ? $window.localStorage : $fakeStorage;
        return {
            set: function(key, value) {
                storage.setItem(key, value);
            },
            get: function(key, defaultValue) {
                return storage.getItem(key) || defaultValue;
            },
            setObject: function(key, value) {
                storage.setItem(key, JSON.stringify(value));
            },
            getObject: function(key) {
                return JSON.parse(storage.getItem(key) || '{}');
            },
            remove: function(key){
                storage.removeItem(key);
            },
            clear: function() {
                storage.clear();
            },
            key: function(index){
                storage.key(index);
            }
        }
    }
]);

Source: https://gist.github.com/jorgecasar/61fda6590dc2bb17e871

Enjoy your coding!

How do I make case-insensitive queries on Mongodb?

MongoDB 3.4 now includes the ability to make a true case-insensitive index, which will dramtically increase the speed of case insensitive lookups on large datasets. It is made by specifying a collation with a strength of 2.

Probably the easiest way to do it is to set a collation on the database. Then all queries inherit that collation and will use it:

db.createCollection("cities", { collation: { locale: 'en_US', strength: 2 } } )
db.names.createIndex( { city: 1 } ) // inherits the default collation

You can also do it like this:

db.myCollection.createIndex({city: 1}, {collation: {locale: "en", strength: 2}});

And use it like this:

db.myCollection.find({city: "new york"}).collation({locale: "en", strength: 2});

This will return cities named "new york", "New York", "New york", etc.

For more info: https://jira.mongodb.org/browse/SERVER-90

Android: adb: Permission Denied

Without rooting: If you can't root your phone, use the run-as <package> command to be able to access data of your application.

Example:

$ adb exec-out run-as com.yourcompany.app ls -R /data/data/com.yourcompany.app/

exec-out executes the command without starting a shell and mangling the output.

$.focus() not working

Had this issue again just now, and believe it or not, all I had to do was close the developer tools. Apparently the Console tab has the focus priority over the page content.

How to write "Html.BeginForm" in Razor

The following code works fine:

@using (Html.BeginForm("Upload", "Upload", FormMethod.Post, 
                                      new { enctype = "multipart/form-data" }))
{
    @Html.ValidationSummary(true)
    <fieldset>
        Select a file <input type="file" name="file" />
        <input type="submit" value="Upload" />
    </fieldset>
}

and generates as expected:

<form action="/Upload/Upload" enctype="multipart/form-data" method="post">    
    <fieldset>
        Select a file <input type="file" name="file" />
        <input type="submit" value="Upload" />
    </fieldset>
</form>

On the other hand if you are writing this code inside the context of other server side construct such as an if or foreach you should remove the @ before the using. For example:

@if (SomeCondition)
{
    using (Html.BeginForm("Upload", "Upload", FormMethod.Post, 
                                      new { enctype = "multipart/form-data" }))
    {
        @Html.ValidationSummary(true)
        <fieldset>
            Select a file <input type="file" name="file" />
            <input type="submit" value="Upload" />
        </fieldset>
    }
}

As far as your server side code is concerned, here's how to proceed:

[HttpPost]
public ActionResult Upload(HttpPostedFileBase file) 
{
    if (file != null && file.ContentLength > 0) 
    {
        var fileName = Path.GetFileName(file.FileName);
        var path = Path.Combine(Server.MapPath("~/content/pics"), fileName);
        file.SaveAs(path);
    }
    return RedirectToAction("Upload");
}

Error occurred during initialization of VM Could not reserve enough space for object heap Could not create the Java virtual machine

If your computer is a 64bit, all you need to do is uninstall your Java x86 version and install a 64bit version. I had the same problem and this worked. Nothing further needs to be done.

Copy filtered data to another sheet using VBA

it needs to be .Row.count not Row.Number?

That's what I used and it works fine Sub TransfersToCleared() Dim ws As Worksheet Dim LastRow As Long Set ws = Application.Worksheets("Export (2)") 'Data Source LastRow = Range("A" & Rows.Count).End(xlUp).Row ws.Range("A2:AB" & LastRow).SpecialCells(xlCellTypeVisible).Copy

How to emulate a do-while loop in Python?

For me a typical while loop will be something like this:

xBool = True
# A counter to force a condition (eg. yCount = some integer value)

while xBool:
    # set up the condition (eg. if yCount > 0):
        (Do something)
        yCount = yCount - 1
    else:
        # (condition is not met, set xBool False)
        xBool = False

I could include a for..loop within the while loop as well, if situation so warrants, for looping through another set of condition.

Creating a pandas DataFrame from columns of other DataFrames with similar indexes

You can use concat:

In [11]: pd.concat([df1['c'], df2['c']], axis=1, keys=['df1', 'df2'])
Out[11]: 
                 df1       df2
2014-01-01       NaN -0.978535
2014-01-02 -0.106510 -0.519239
2014-01-03 -0.846100 -0.313153
2014-01-04 -0.014253 -1.040702
2014-01-05  0.315156 -0.329967
2014-01-06 -0.510577 -0.940901
2014-01-07       NaN -0.024608
2014-01-08       NaN -1.791899

[8 rows x 2 columns]

The axis argument determines the way the DataFrames are stacked:

df1 = pd.DataFrame([1, 2, 3])
df2 = pd.DataFrame(['a', 'b', 'c'])

pd.concat([df1, df2], axis=0)
   0
0  1
1  2
2  3
0  a
1  b
2  c

pd.concat([df1, df2], axis=1)

   0  0
0  1  a
1  2  b
2  3  c

How to concatenate two IEnumerable<T> into a new IEnumerable<T>?

The Concat method will return an object which implements IEnumerable<T> by returning an object (call it Cat) whose enumerator will attempt to use the two passed-in enumerable items (call them A and B) in sequence. If the passed-in enumerables represent sequences which will not change during the lifetime of Cat, and which can be read from without side-effects, then Cat may be used directly. Otherwise, it may be a good idea to call ToList() on Cat and use the resulting List<T> (which will represent a snapshot of the contents of A and B).

Some enumerables take a snapshot when enumeration begins, and will return data from that snapshot if the collection is modified during enumeration. If B is such an enumerable, then any change to B which occurs before Cat has reached the end of A will show up in Cat's enumeration, but changes which occur after that will not. Such semantics may likely be confusing; taking a snapshot of Cat can avoid such issues.

What is python's site-packages directory?

When you use --user option with pip, the package gets installed in user's folder instead of global folder and you won't need to run pip command with admin privileges.

The location of user's packages folder can be found using:

python -m site --user-site

This will print something like:

C:\Users\%USERNAME%\AppData\Roaming\Python\Python35\site-packages

When you don't use --user option with pip, the package gets installed in global folder given by:

python -c "import site; print(site.getsitepackages())"

This will print something like:

['C:\\Program Files\\Anaconda3', 'C:\\Program Files\\Anaconda3\\lib\\site-packages'

Note: Above printed values are for On Windows 10 with Anaconda 4.x installed with defaults.

How to get form input array into PHP array

Using this method should work:

$name = $_POST['name'];
$email = $_POST['account'];
while($explore=each($email)) {
    echo $explore['key'];
    echo "-";
    echo $explore['value'];
    echo "<br/>";
}

list.clear() vs list = new ArrayList<Integer>();

It's hard to know without a benchmark, but if you have lots of items in your ArrayList and the average size is lower, it might be faster to make a new ArrayList.

http://www.docjar.com/html/api/java/util/ArrayList.java.html

public void clear() {
    modCount++;

    // Let gc do its work
    for (int i = 0; i < size; i++)
        elementData[i] = null;

    size = 0;
}

Actual meaning of 'shell=True' in subprocess

An example where things could go wrong with Shell=True is shown here

>>> from subprocess import call
>>> filename = input("What file would you like to display?\n")
What file would you like to display?
non_existent; rm -rf / # THIS WILL DELETE EVERYTHING IN ROOT PARTITION!!!
>>> call("cat " + filename, shell=True) # Uh-oh. This will end badly...

Check the doc here: subprocess.call()

How do I return multiple values from a function in C?

One approach is to use macros. Place this in a header file multitype.h

#include <stdlib.h>

/* ============================= HELPER MACROS ============================= */

/* __typeof__(V) abbreviation */

#define TOF(V) __typeof__(V)

/* Expand variables list to list of typeof and variable names */

#define TO3(_0,_1,_2,_3) TOF(_0) v0; TOF(_1) v1; TOF(_2) v2; TOF(_3) v3;
#define TO2(_0,_1,_2)    TOF(_0) v0; TOF(_1) v1; TOF(_2) v2;
#define TO1(_0,_1)       TOF(_0) v0; TOF(_1) v1;
#define TO0(_0)          TOF(_0) v0;

#define TO_(_0,_1,_2,_3,TO_MACRO,...) TO_MACRO

#define TO(...) TO_(__VA_ARGS__,TO3,TO2,TO1,TO0)(__VA_ARGS__)

/* Assign to multitype */

#define MTA3(_0,_1,_2,_3) _0 = mtr.v0; _1 = mtr.v1; _2 = mtr.v2; _3 = mtr.v3;
#define MTA2(_0,_1,_2)    _0 = mtr.v0; _1 = mtr.v1; _2 = mtr.v2;
#define MTA1(_0,_1)       _0 = mtr.v0; _1 = mtr.v1;
#define MTA0(_0)          _0 = mtr.v0;

#define MTA_(_0,_1,_2,_3,MTA_MACRO,...) MTA_MACRO

#define MTA(...) MTA_(__VA_ARGS__,MTA3,MTA2,MTA1,MTA0)(__VA_ARGS__)

/* Return multitype if multiple arguments, return normally if only one */

#define MTR1(...) {                                                           \
    typedef struct mtr_s {                                                    \
      TO(__VA_ARGS__)                                                         \
    } mtr_t;                                                                  \
    mtr_t *mtr = malloc(sizeof(mtr_t));                                       \
    *mtr = (mtr_t){__VA_ARGS__};                                              \
    return mtr;                                                               \
  }

#define MTR0(_0) return(_0)

#define MTR_(_0,_1,_2,_3,MTR_MACRO,...) MTR_MACRO

/* ============================== API MACROS =============================== */

/* Declare return type before function */

typedef void* multitype;

#define multitype(...) multitype

/* Assign return values to variables */

#define let(...)                                                              \
  for(int mti = 0; !mti;)                                                     \
    for(multitype mt; mti < 2; mti++)                                         \
      if(mti) {                                                               \
        typedef struct mtr_s {                                                \
          TO(__VA_ARGS__)                                                     \
        } mtr_t;                                                              \
        mtr_t mtr = *(mtr_t*)mt;                                              \
        MTA(__VA_ARGS__)                                                      \
        free(mt);                                                             \
      } else                                                                  \
        mt

/* Return */

#define RETURN(...) MTR_(__VA_ARGS__,MTR1,MTR1,MTR1,MTR0)(__VA_ARGS__)

This makes it possible to return up to four variables from a function and assign them to up to four variables. As an example, you can use them like this:

multitype (int,float,double) fun() {
    int a = 55;
    float b = 3.9;
    double c = 24.15;

    RETURN (a,b,c);
}

int main(int argc, char *argv[]) {
    int x;
    float y;
    double z;

    let (x,y,z) = fun();

    printf("(%d, %f, %g\n)", x, y, z);

    return 0;
}

This is what it prints:

(55, 3.9, 24.15)

The solution may not be as portable because it requires C99 or later for variadic macros and for-statement variable declarations. But I think it was interesting enough to post here. Another issue is that the compiler will not warn you if you assign them the wrong values, so you have to be careful.

Additional examples, and a stack-based version of the code using unions, are available at my github repository.

"No rule to make target 'install'"... But Makefile exists

Could you provide a whole makefile? But right now I can tell - you should check that "install" target already exists. So, check Makefile whether it contains a

install: (anything there)

line. If not, there is no such target and so make has right. Probably you should use just "make" command to compile and then use it as is or install yourself, manually.

Install is not any standard of make, it is just a common target, that could exists, but not necessary.

how to display data values on Chart.js

I'd recommend using this plugin: https://github.com/chartjs/chartjs-plugin-datalabels

Labels can be added to your charts simply by importing the plugin to the js file e.g.:

import 'chartjs-plugin-datalabels'

And can be fine tuned using these docs: https://chartjs-plugin-datalabels.netlify.com/options.html

PHP String to Float

I was running in to a problem with the standard way to do this:

$string = "one";

$float = (float)$string;

echo $float; : ( Prints 0 )

If there isn't a valid number, the parser shouldn't return a number, it should throw an error. (This is a condition I'm trying to catch in my code, YMMV)

To fix this I have done the following:

$string = "one";

$float = is_numeric($string) ? (float)$string : null;

echo $float; : ( Prints nothing )

Then before further processing the conversion, I can check and return an error if there wasn't a valid parse of the string.

SQL Group By with an Order By

In Oracle, something like this works nicely to separate your counting and ordering a little better. I'm not sure if it will work in MySql 4.

select 'Tag', counts.cnt
from
  (
  select count(*) as cnt, 'Tag'
  from 'images-tags'
  group by 'tag'
  ) counts
order by counts.cnt desc

resize2fs: Bad magic number in super-block while trying to open

os: rhel7

After gparted, # xfs_growfs /dev/mapper/rhel-root did the trick on a living system.

$ df -h
Filesystem             Size  Used Avail Use% Mounted on
/dev/mapper/rhel-root   47G   47G   20M 100% /
devtmpfs               1.9G     0  1.9G   0% /dev
tmpfs                  1.9G     0  1.9G   0% /dev/shm
tmpfs                  1.9G  9.3M  1.9G   1% /run
tmpfs                  1.9G     0  1.9G   0% /sys/fs/cgroup
/dev/sda1             1014M  205M  810M  21% /boot
tmpfs                  379M  8.0K  379M   1% /run/user/42
tmpfs                  379M     0  379M   0% /run/user/1000


# lvresize -l +100%FREE /dev/mapper/rhel-root
  Size of logical volume rhel/root changed from <47.00 GiB (12031 extents) to <77.00 GiB (19711 extents).
  Logical volume rhel/root successfully resized.


# xfs_growfs /dev/mapper/rhel-root
meta-data=/dev/mapper/rhel-root  isize=512    agcount=7, agsize=1900032 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0 spinodes=0
data     =                       bsize=4096   blocks=12319744, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal               bsize=4096   blocks=3711, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 12319744 to 20184064


# df -h
Filesystem             Size  Used Avail Use% Mounted on
/dev/mapper/rhel-root   77G   47G   31G  62% /
devtmpfs               1.9G     0  1.9G   0% /dev
tmpfs                  1.9G     0  1.9G   0% /dev/shm
tmpfs                  1.9G  9.3M  1.9G   1% /run
tmpfs                  1.9G     0  1.9G   0% /sys/fs/cgroup
/dev/sda1             1014M  205M  810M  21% /boot
tmpfs                  379M  8.0K  379M   1% /run/user/42
tmpfs                  379M     0  379M   0% /run/user/1000

Failed to load c++ bson extension

I was trying to run node on virtual machine (vagrant) shared folder. That was a problem. My host machine is Windows, installed node on Windows and worked like a charm. So if you are using virtual machine, just try to run node server on host machine.

How do I set a column value to NULL in SQL Server Management Studio?

If you are using the table interface you can type in NULL (all caps)

otherwise you can run an update statement where you could:

Update table set ColumnName = NULL where [Filter for record here]

Extract values in Pandas value_counts()

Try this:

dataframe[column].value_counts().index.tolist()
['apple', 'sausage', 'banana', 'cheese']

Change value of variable with dplyr

We can use replace to change the values in 'mpg' to NA that corresponds to cyl==4.

mtcars %>%
     mutate(mpg=replace(mpg, cyl==4, NA)) %>%
     as.data.frame()

"This project is incompatible with the current version of Visual Studio"

This issue might be caused when using VS 2015 with Update 3 installed on one PC and without update 3 installed on another. This was the problem in my case.

How to use Python's "easy_install" on Windows ... it's not so easy

I also agree with the OP that all these things should come with Python already set. I guess we will have to deal with it until that day comes. Here is a solution that actually worked for me :

installing easy_install faster and easier

I hope it helps you or anyone with the same problem!

How can we generate getters and setters in Visual Studio?

In Visual Studio Community Edition 2015 you can select all the fields you want and then press Ctrl + . to automatically generate the properties.

You have to choose if you want to use the property instead of the field or not.

Passing parameters to a JQuery function

If you want to do an ajax call or a simple javascript function, don't forget to close your function with the return false

like this:

function DoAction(id, name) 
{ 
    // your code
    return false;
}

Unable to add window -- token null is not valid; is your activity running?

If you use another view make sure to use view.getContext() instead of this or getApplicationContext()

Is there an eval() function in Java?

There is no standard Java class or method that will do what you want. Your options include:

  • Select and use some third-party expression evaluation library. For example JEL or any of the half dozen libraries listed here.

  • Wrap the expression in the Java source code for a class with an eval method, send that to the Java compiler, and then load the resulting compiled class.

  • Use some scripting language that can be called from Java as an expression evaluator. Possibilities include Javascript, BeanShell, and so on.

  • Write your own expression evaluator from scratch.

The first approach is probably simplest. The second and third approaches are a potential security risk if you get the expression to be evaluated from an untrusted user. (Think code injection.)

EntityType 'IdentityUserLogin' has no key defined. Define the key for this EntityType

For those who use ASP.NET Identity 2.1 and have changed the primary key from the default string to either int or Guid, if you're still getting

EntityType 'xxxxUserLogin' has no key defined. Define the key for this EntityType.

EntityType 'xxxxUserRole' has no key defined. Define the key for this EntityType.

you probably just forgot to specify the new key type on IdentityDbContext:

public class AppIdentityDbContext : IdentityDbContext<
    AppUser, AppRole, int, AppUserLogin, AppUserRole, AppUserClaim>
{
    public AppIdentityDbContext()
        : base("MY_CONNECTION_STRING")
    {
    }
    ......
}

If you just have

public class AppIdentityDbContext : IdentityDbContext
{
    ......
}

or even

public class AppIdentityDbContext : IdentityDbContext<AppUser>
{
    ......
}

you will get that 'no key defined' error when you are trying to add migrations or update the database.

How to check if a variable is both null and /or undefined in JavaScript

A variable cannot be both null and undefined at the same time. However, the direct answer to your question is:

if (variable != null)

One =, not two.

There are two special clauses in the "abstract equality comparison algorithm" in the JavaScript spec devoted to the case of one operand being null and the other being undefined, and the result is true for == and false for !=. Thus if the value of the variable is undefined, it's not != null, and if it's not null, it's obviously not != null.

Now, the case of an identifier not being defined at all, either as a var or let, as a function parameter, or as a property of the global context is different. A reference to such an identifier is treated as an error at runtime. You could attempt a reference and catch the error:

var isDefined = false;
try {
  (variable);
  isDefined = true;
}
catch (x) {}

I would personally consider that a questionable practice however. For global symbols that may or may be there based on the presence or absence of some other library, or some similar situation, you can test for a window property (in browser JavaScript):

var isJqueryAvailable = window.jQuery != null;

or

var isJqueryAvailable = "jQuery" in window;

How do I search an SQL Server database for a string?

Here is the same script as submitted by user l--''''''---------'''''''''''', but corrected to work on a case-sensitive SQL instance, and with some other minor improvements.

DROP PROCEDURE IF EXISTS dbo.spFind_Text_In_Database
GO

CREATE PROCEDURE dbo.spFind_Text_In_Database
    @strText_To_Find NVARCHAR(4000),
    @bitExact_Match BIT = 0
AS
SET NOCOUNT ON

DECLARE @Temp TABLE(RowId INT IDENTITY(1,1), SchemaName sysname, TableName sysname, ColumnName SysName, DataType VARCHAR(100), DataFound BIT)

    INSERT  INTO @Temp(TableName,SchemaName, ColumnName, DataType)
    SELECT  C.TABLE_NAME, C.TABLE_SCHEMA, C.COLUMN_NAME, C.DATA_TYPE
    FROM    INFORMATION_SCHEMA.COLUMNS AS C
            INNER Join INFORMATION_SCHEMA.TABLES AS T
                ON C.TABLE_NAME = T.TABLE_NAME
        AND C.TABLE_SCHEMA = T.TABLE_SCHEMA
    WHERE   TABLE_TYPE = 'BASE TABLE'
            And DATA_TYPE In ('ntext','text','nvarchar','nchar','varchar','char')


DECLARE @i INT
DECLARE @MAX INT
DECLARE @TableName sysname
DECLARE @ColumnName sysname
DECLARE @SchemaName sysname
DECLARE @SQL NVARCHAR(4000)
DECLARE @PARAMETERS NVARCHAR(4000)
DECLARE @DataExists BIT
DECLARE @SQLTemplate NVARCHAR(4000)

SELECT  @SQLTemplate = CASE WHEN @bitExact_Match = 1
                            THEN 'If Exists(Select *
                                          From   ReplaceTableName
                                          Where  Convert(nVarChar(4000), [ReplaceColumnName])
                                                       = ''' + @strText_To_Find + '''
                                          )
                                     Set @DataExists = 1
                                 Else
                                     Set @DataExists = 0'
                            ELSE 'If Exists(Select *
                                          From   ReplaceTableName
                                          Where  Convert(nVarChar(4000), [ReplaceColumnName])
                                                       Like ''%' + @strText_To_Find + '%''
                                          )
                                     Set @DataExists = 1
                                 Else
                                     Set @DataExists = 0'
                            END,
        @PARAMETERS = '@DataExists Bit OUTPUT',
        @i = 1

SELECT @i = 1, @MAX = MAX(RowId)
FROM   @Temp

WHILE @i <= @MAX
    BEGIN
        SELECT  @SQL = REPLACE(REPLACE(@SQLTemplate, 'ReplaceTableName', QUOTENAME(SchemaName) + '.' + QUOTENAME(TableName)), 'ReplaceColumnName', ColumnName)
        FROM    @Temp
        WHERE   RowId = @i


        PRINT @SQL
        EXEC sp_executesql @SQL, @PARAMETERS, @DataExists = @DataExists OUTPUT

        IF @DataExists =1
            UPDATE @Temp SET DataFound = 1 WHERE RowId = @i

        SET @i = @i + 1
    END

SELECT  SchemaName,TableName, ColumnName
FROM    @Temp
WHERE   DataFound = 1
GO

Excel VBA Password via Hex Editor

New version, now you also have the GC= try to replace both DPB and GC with those

DPB="DBD9775A4B774B77B4894C77DFE8FE6D2CCEB951E8045C2AB7CA507D8F3AC7E3A7F59012A2" GC="BAB816BBF4BCF4BCF4"

password will be "test"

How to add an existing folder with files to SVN?

I don't use commands. You should be able to do this using the GUI:

  • Right-click an empty space in your My Documents folder, select TortoiseSVN > Repo-browser.
  • Enter http://subversion... (your URL path to your Subversion server/directory you will save to) as your path and select OK
  • Right-click the root directory in Repo and select Add folder. Give it the name of your project and create it.
  • Right-click the project folder in the Repo-browser and select Checkout. The Checkout directory will be your Visual Studio\Projects\{your project} folder. Select OK.
  • You will receive a warning that the folder is not empty. Say Yes to checkout/export to that folder - it will not overwrite your project files.
  • Open your project folder. You will see question marks on folders that are associated with your VS project that have not yet been added to Subversion. Select those folders using Ctrl + Click, then right-click one of the selected items and select TortoiseSVN > Add
  • Select OK on the prompt
  • Your files should add. Select OK on the Add Finished! dialog
  • Right-click in an empty area of the folder and select Refresh. You’ll see “+” icons on the folders/files, now
  • Right-click an empty area in the folder once again and select SVN Commit
  • Add a message regarding what you are committing and click OK

What does elementFormDefault do in XSD?

Consider the following ComplexType AuthorType used by author element

<xsd:complexType name="AuthorType">
  <!-- compositor goes here -->
  <xsd:sequence>
     <xsd:element name="name" type="xsd:string"/>
     <xsd:element name="phone" type="tns:Phone"/>
  </xsd:sequence>
  <xsd:attribute name="id" type="tns:AuthorId"/>
</xsd:complexType>
<xsd:element name="author" type="tns:AuthorType"/>

If elementFormDefault="unqualified"

then following XML Instance is valid

<x:author xmlns:x="http://example.org/publishing">
   <name>Aaron Skonnard</name>
   <phone>(801)390-4552</phone>
</x:author>

the authors's name attribute is allowed without specifying the namespace(unqualified). Any elements which are a part of <xsd:complexType> are considered as local to complexType.

if elementFormDefault="qualified"

then the instance should have the local elements qualified

<x:author xmlns:x="http://example.org/publishing">
   <x:name>Aaron Skonnard</name>
   <x:phone>(801)390-4552</phone>
</x:author>

please refer this link for more details

How can I remove the decimal part from JavaScript number?

With ES2015, Math.trunc() is available.

Math.trunc(2.3)                       // 2
Math.trunc(-2.3)                      // -2
Math.trunc(22222222222222222222222.3) // 2.2222222222222223e+22
Math.trunc("2.3")                     // 2
Math.trunc("two")                     // NaN
Math.trunc(NaN)                       // NaN

It's not supported in IE11 or below, but does work in Edge and every other modern browser.

How to use variables in a command in sed?

Say:

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

Note:

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

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

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

The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)

Check to see if the Remote Procedure Call (RPC) service is running. If it is, then it's a firewall issue between your workstation and the server. You can test it by temporary disabling the firewall and retrying the command.

Edit after comment:

Ok, it's a firewall issue. You'll have to either limit the ports WMI/RPC work on, or open a lot of ports in the McAfee firewall.

Here are a few sites that explain this:

  1. Microsoft KB for limiting ports
  2. McAfee site talking about the same thing

How does += (plus equal) work?

x+=y is shorthand in many languages for set x to x + y. The sum will be, as hinted by its name, the sum of the numbers in data.

What is the purpose of Node.js module.exports and how do you use it?

This has already been answered but I wanted to add some clarification...

You can use both exports and module.exports to import code into your application like this:

var mycode = require('./path/to/mycode');

The basic use case you'll see (e.g. in ExpressJS example code) is that you set properties on the exports object in a .js file that you then import using require()

So in a simple counting example, you could have:

(counter.js):

var count = 1;

exports.increment = function() {
    count++;
};

exports.getCount = function() {
    return count;
};

... then in your application (web.js, or really any other .js file):

var counting = require('./counter.js');

console.log(counting.getCount()); // 1
counting.increment();
console.log(counting.getCount()); // 2

In simple terms, you can think of required files as functions that return a single object, and you can add properties (strings, numbers, arrays, functions, anything) to the object that's returned by setting them on exports.

Sometimes you'll want the object returned from a require() call to be a function you can call, rather than just an object with properties. In that case you need to also set module.exports, like this:

(sayhello.js):

module.exports = exports = function() {
    console.log("Hello World!");
};

(app.js):

var sayHello = require('./sayhello.js');
sayHello(); // "Hello World!"

The difference between exports and module.exports is explained better in this answer here.

When I run `npm install`, it returns with `ERR! code EINTEGRITY` (npm 5.3.0)

I had a very similar problem, and in my case it worked by doing:

npm clean

This is the nuclear option since it clears every package from the cache as expained here.

Docker compose port mapping

It seems like the other answers here all misunderstood your question. If I understand correctly, you want to make requests to localhost:6379 (the default for redis) and have them be forwarded, automatically, to the same port on your redis container.

https://unix.stackexchange.com/a/101906/38639 helped me get to the right answer.

First, you'll need to install the nc command on your image. On CentOS, this package is called nmap-ncat, so in the example below, just replace this with the appropriate package if you are using a different OS as your base image.

Next, you'll need to tell it to run a certain command each time the container boots up. You can do this using CMD.

# Add this to your Dockerfile
RUN yum install -y --setopt=skip_missing_names_on_install=False nmap-ncat
COPY cmd.sh /usr/local/bin/cmd.sh
RUN chmod +x /usr/local/bin/cmd.sh
CMD ["/usr/local/bin/cmd.sh"]

Finally, we'll need to set up port-forwarding in cmd.sh. I found that nc, even with the -l and -k options, will occasionally terminate when a request is completed, so I'm using a while-loop to ensure that it's always running.

# cmd.sh
#! /usr/bin/env bash

while nc -l -p 6379 -k -c "nc redis 6379" || true; do true; done &

tail -f /dev/null # Or any other command that never exits

Is there an easy way to convert jquery code to javascript?

I can see a reason, unrelated to the original post, to automatically compile jQuery code into standard JavaScript:

16k -- or whatever the gzipped, minified jQuery library is -- might be too much for your website that is intended for a mobile browser. The w3c is recommending that all HTTP requests for mobile websites should be a maximum of 20k.

w3c specs for mobile

So I enjoy coding in my nice, terse, chained jQuery. But now I need to optimize for mobile. Should I really go back and do the difficult, tedious work of rewriting all the helper functions I used in the jQuery library? Or is there some kind of convenient app that will help me recompile?

That would be very sweet. Sadly, I don't think such a thing exists.

What do \t and \b do?

Backspace and tab both move the cursor position. Neither is truly a 'printable' character.

Your code says:

  1. print "foo"
  2. move the cursor back one space
  3. move the cursor forward to the next tabstop
  4. output "bar".

To get the output you expect, you need printf("foo\b \tbar"). Note the extra 'space'. That says:

  1. output "foo"
  2. move the cursor back one space
  3. output a ' ' (this replaces the second 'o').
  4. move the cursor forward to the next tabstop
  5. output "bar".

Most of the time it is inappropriate to use tabs and backspace for formatting your program output. Learn to use printf() formatting specifiers. Rendering of tabs can vary drastically depending on how the output is viewed.

This little script shows one way to alter your terminal's tab rendering. Tested on Ubuntu + gnome-terminal:

#!/bin/bash
tabs -8 
echo -e "\tnormal tabstop"
for x in `seq 2 10`; do
  tabs $x
  echo -e "\ttabstop=$x"
 done

tabs -8
echo -e "\tnormal tabstop"

Also see man setterm and regtabs.

And if you redirect your output or just write to a file, tabs will quite commonly be displayed as fewer than the standard 8 chars, especially in "programming" editors and IDEs.

So in otherwords:

printf("%-8s%s", "foo", "bar"); /* this will ALWAYS output "foo     bar" */
printf("foo\tbar"); /* who knows how this will be rendered */

IMHO, tabs in general are rarely appropriate for anything. An exception might be generating output for a program that requires tab-separated-value input files (similar to comma separated value).

Backspace '\b' is a different story... it should never be used to create a text file since it will just make a text editor spit out garbage. But it does have many applications in writing interactive command line programs that cannot be accomplished with format strings alone. If you find yourself needing it a lot, check out "ncurses", which gives you much better control over where your output goes on the terminal screen. And typically, since it's 2011 and not 1995, a GUI is usually easier to deal with for highly interactive programs. But again, there are exceptions. Like writing a telnet server or console for a new scripting language.

How to delete files older than X hours

You could to this trick: create a file 1 hour ago, and use the -newer file argument.

(Or use touch -t to create such a file).

Conflict with dependency 'com.android.support:support-annotations' in project ':app'. Resolved versions for app (26.1.0) and test app (27.1.1) differ.

Go to the build.gradle(Module App) in your project:

enter image description here

Follow the pic and change those version:

compileSdkVersion: 27
targetSdkVersion: 27

and if android studio version 2: Change the line with this line:

compile 'com.android.support:appcompat-v7:27.1.1'

else Change the line with this line:

implementation 'com.android.support:appcompat-v7:27.1.1'

and hopefully, you will solve your bug.

Defining arrays in Google Scripts

Try this

function readRows() {
  var sheet = SpreadsheetApp.getActiveSheet();
  var rows = sheet.getDataRange();
  var numRows = rows.getNumRows();
  //var values = rows.getValues();

  var Names = sheet.getRange("A2:A7");
  var Name = [
    Names.getCell(1, 1).getValue(),
    Names.getCell(2, 1).getValue(),
    .....
    Names.getCell(5, 1).getValue()]

You can define arrays simply as follows, instead of allocating and then assigning.

var arr = [1,2,3,5]

Your initial error was because of the following line, and ones like it

var Name[0] = Name_cell.getValue(); 

Since Name is already defined and you are assigning the values to its elements, you should skip the var, so just

Name[0] = Name_cell.getValue();

Pro tip: For most issues that, like this one, don't directly involve Google services, you are better off Googling for the way to do it in javascript in general.

Service will not start: error 1067: the process terminated unexpectedly

Goto:

Registry-> HKEY_LOCAL??_MACHINE-> System-> Cur??rentControlSet-> Servi??ces.

Find the concerned service & delete it. Close regedit. Reboot the PC & Re-install the concerned service. Now the error should be gone.

Matplotlib transparent line plots

After I plotted all the lines, I was able to set the transparency of all of them as follows:

for l in fig_field.gca().lines:
    l.set_alpha(.7)

EDIT: please see Joe's answer in the comments.

CROSS JOIN vs INNER JOIN in SQL

Inner Join

The join that displays only the rows that have a match in both the joined tables is known as inner join. This is default join in the query and view Designer.

Syntax for Inner Join

SELECT t1.column_name,t2.column_name
FROM table_name1 t1
INNER JOIN table_name2 t2
ON t1.column_name=t2.column_name

Cross Join

A cross join that produces Cartesian product of the tables that involved in the join. The size of a Cartesian product is the number of the rows in first table multiplied by the number of rows in the second table.

Syntax for Cross Join

SELECT * FROM table_name1
CROSS JOIN table_name2

Or we can write it in another way also

SELECT * FROM table_name1,table_name2

Now check the query below for Cross join

Example

SELECT * FROM UserDetails
CROSS JOIN OrderDetails

Or

SELECT * FROM UserDetails, OrderDetails

How to pass data using NotificationCenter in swift 3.0 and NSNotificationCenter in swift 2.0?

Swift 2.0

Pass info using userInfo which is a optional Dictionary of type [NSObject : AnyObject]?

  let imageDataDict:[String: UIImage] = ["image": image]

  // Post a notification
  NSNotificationCenter.defaultCenter().postNotificationName(notificationName, object: nil, userInfo: imageDataDict)

 // Register to receive notification in your class
 NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(self.showSpinningWheel(_:)), name: notificationName, object: nil)

 // handle notification
 func showSpinningWheel(notification: NSNotification) { 

  if let image = notification.userInfo?["image"] as? UIImage {
  // do something with your image   
  }
 }

Swift 3.0 version and above

The userInfo now takes [AnyHashable:Any]? as an argument, which we provide as a dictionary literal in Swift

  let imageDataDict:[String: UIImage] = ["image": image]

  // post a notification
  NotificationCenter.default.post(name: NSNotification.Name(rawValue: "notificationName"), object: nil, userInfo: imageDataDict) 
  // `default` is now a property, not a method call

 // Register to receive notification in your class
 NotificationCenter.default.addObserver(self, selector: #selector(self.showSpinningWheel(_:)), name: NSNotification.Name(rawValue: "notificationName"), object: nil)

 // handle notification
 // For swift 4.0 and above put @objc attribute in front of function Definition  
 func showSpinningWheel(_ notification: NSNotification) {

  if let image = notification.userInfo?["image"] as? UIImage {
  // do something with your image   
  }
 }

NOTE: Notification “names” are no longer strings, but are of type Notification.Name, hence why we are using NSNotification.Name(rawValue:"notificationName") and we can extend Notification.Name with our own custom notifications.

extension Notification.Name {
static let myNotification = Notification.Name("myNotification")
}

// and post notification like this
NotificationCenter.default.post(name: .myNotification, object: nil)

Why do many examples use `fig, ax = plt.subplots()` in Matplotlib/pyplot/python

In addition to the answers above, you can check the type of object using type(plt.subplots()) which returns a tuple, on the other hand, type(plt.subplot()) returns matplotlib.axes._subplots.AxesSubplot which you can't unpack.

Difference between Hive internal tables and external tables?

Consider this scenario which best suits for External Table:

A MapReduce (MR) job filters a huge log file to spit out n sub log files (e.g. each sub log file contains a specific message type log) and the output i.e n sub log files are stored in hdfs.

These log files are to be loaded into Hive tables for performing further analytic, in this scenario I would recommend an External Table(s), because the actual log files are generated and owned by an external process i.e. a MR job besides you can avoid an additional step of loading each generated log file into respective Hive table as well.

How to write to Console.Out during execution of an MSTest test

I had the same issue and I was "Running" the tests. If I instead "Debug" the tests the Debug output shows just fine like all others Trace and Console. I don't know though how to see the output if you "Run" the tests.

Why does C++ compilation take so long?

The biggest issues are:

1) The infinite header reparsing. Already mentioned. Mitigations (like #pragma once) usually only work per compilation unit, not per build.

2) The fact that the toolchain is often separated into multiple binaries (make, preprocessor, compiler, assembler, archiver, impdef, linker, and dlltool in extreme cases) that all have to reinitialize and reload all state all the time for each invocation (compiler, assembler) or every couple of files (archiver, linker, and dlltool).

See also this discussion on comp.compilers: http://compilers.iecc.com/comparch/article/03-11-078 specially this one:

http://compilers.iecc.com/comparch/article/02-07-128

Note that John, the moderator of comp.compilers seems to agree, and that this means it should be possible to achieve similar speeds for C too, if one integrates the toolchain fully and implements precompiled headers. Many commercial C compilers do this to some degree.

Note that the Unix model of factoring everything out to a separate binary is a kind of the worst case model for Windows (with its slow process creation). It is very noticable when comparing GCC build times between Windows and *nix, especially if the make/configure system also calls some programs just to obtain information.

Trim a string in C

#include "stdafx.h"
#include <string.h>
#include <ctype.h>

char* trim(char* input);


int _tmain(int argc, _TCHAR* argv[])
{
    char sz1[]="  MQRFH  ";
    char sz2[]=" MQRFH";
    char sz3[]="  MQR FH";
    char sz4[]="MQRFH  ";
    char sz5[]="MQRFH";
    char sz6[]="M";
    char sz7[]="M ";
    char sz8[]=" M";
    char sz9[]="";
    char sz10[]="        ";

    printf("sz1:[%s] %d\n",trim(sz1), strlen(sz1));
    printf("sz2:[%s] %d\n",trim(sz2), strlen(sz2));
    printf("sz3:[%s] %d\n",trim(sz3), strlen(sz3));
    printf("sz4:[%s] %d\n",trim(sz4), strlen(sz4));
    printf("sz5:[%s] %d\n",trim(sz5), strlen(sz5));
    printf("sz6:[%s] %d\n",trim(sz6), strlen(sz6));
    printf("sz7:[%s] %d\n",trim(sz7), strlen(sz7));
    printf("sz8:[%s] %d\n",trim(sz8), strlen(sz8));
    printf("sz9:[%s] %d\n",trim(sz9), strlen(sz9));
    printf("sz10:[%s] %d\n",trim(sz10), strlen(sz10));

    return 0;
}

char *ltrim(char *s) 
{     
    while(isspace(*s)) s++;     
    return s; 
}  

char *rtrim(char *s) 
{     
    char* back;
    int len = strlen(s);

    if(len == 0)
        return(s); 

    back = s + len;     
    while(isspace(*--back));     
    *(back+1) = '\0';     
    return s; 
}  

char *trim(char *s) 
{     
    return rtrim(ltrim(s));  
} 

Output:

sz1:[MQRFH] 9
sz2:[MQRFH] 6
sz3:[MQR FH] 8
sz4:[MQRFH] 7
sz5:[MQRFH] 5
sz6:[M] 1
sz7:[M] 2
sz8:[M] 2
sz9:[] 0
sz10:[] 8

How to get rid of blank pages in PDF exported from SSRS

If the pages are blank coming from SSRS, you need to tweak your report layout. This will be far more efficient than running the output through and post process to repair the side effects of a layout problem.

SSRS is very finicky when it comes to pushing the boundaries of the margins. It is easy to accidentally widen/lengthen the report just by adjusting text box or other control on the report. Check the width and height property of the report surface carefully and squeeze them as much as possible. Watch out for large headers and footers.

Xcode is not currently available from the Software Update server

Had the same issue and was getting the same error. When i ran xcode-select -p, it gave output as /Library/Developer/CommandLineTools. So that means xcode was already installed in my system. Then i ran steps as given on this answer. After which any command which required xcode ran successfully.

How do I make a PHP form that submits to self?

That will only work if register_globals is on, and it should never be on (unless of course you are defining that variable somewhere else).

Try setting the form's action attribute to ?...

<form method="post" action="?">
   ...
</form>

You can also set it to be blank (""), but older WebKit versions had a bug.

Byte[] to InputStream or OutputStream

we can convert byte[] array into input stream by using ByteArrayInputStream

String str = "Welcome to awesome Java World";
    byte[] content = str.getBytes();
    int size = content.length;
    InputStream is = null;
    byte[] b = new byte[size];
    is = new ByteArrayInputStream(content);

For full example please check here http://www.onlinecodegeek.com/2015/09/how-to-convert-byte-into-inputstream.html

Login with facebook android sdk app crash API 4

The official answer from Facebook (http://developers.facebook.com/bugs/282710765082535):

Mikhail,

The facebook android sdk no longer supports android 1.5 and 1.6. Please upgrade to the next api version.

Good luck with your implementation.

git stash apply version

If one is on a Windows machine and in PowerShell, one needs to quote the argument such as:

git stash apply "stash@{0}"

...or to apply the changes and remove from the stash:

git stash pop "stash@{0}"

Otherwise without the quotes you might get this error:

fatal: ambiguous argument 'stash@': unknown revision or path not in the working tree.

How do I get AWS_ACCESS_KEY_ID for Amazon?

It is very dangerous to create an access_key_id in "My Account ==> Security Credentials". Because the key has all authority. Please create "IAM" user and attach only some policies you need.

replace NULL with Blank value or Zero in sql server

You can use the COALESCE function to automatically return null values as 0. Syntax is as shown below:

SELECT COALESCE(total_amount, 0) from #Temp1

Android basics: running code in the UI thread

As of Android P you can use getMainExecutor():

getMainExecutor().execute(new Runnable() {
  @Override public void run() {
    // Code will run on the main thread
  }
});

From the Android developer docs:

Return an Executor that will run enqueued tasks on the main thread associated with this context. This is the thread used to dispatch calls to application components (activities, services, etc).

From the CommonsBlog:

You can call getMainExecutor() on Context to get an Executor that will execute its jobs on the main application thread. There are other ways of accomplishing this, using Looper and a custom Executor implementation, but this is simpler.

Is there a way to retrieve the view definition from a SQL Server using plain ADO?

Microsoft listed the following methods for getting the a View definition: http://technet.microsoft.com/en-us/library/ms175067.aspx


USE AdventureWorks2012;
GO
SELECT definition, uses_ansi_nulls, uses_quoted_identifier, is_schema_bound
FROM sys.sql_modules
WHERE object_id = OBJECT_ID('HumanResources.vEmployee'); 
GO

USE AdventureWorks2012; 
GO
SELECT OBJECT_DEFINITION (OBJECT_ID('HumanResources.vEmployee')) 
AS ObjectDefinition; 
GO

EXEC sp_helptext 'HumanResources.vEmployee';

How to access a preexisting collection with Mongoose?

Go to MongoDB website, Login > Connect > Connect Application > Copy > Paste in 'database_url' > Collections > Copy/Paste in 'collection' .

var mongoose = require("mongoose");
mongoose.connect(' database_url ');
var conn = mongoose.connection;
conn.on('error', console.error.bind(console, 'connection error:'));
conn.once('open', function () {

conn.db.collection(" collection ", function(err, collection){

    collection.find({}).toArray(function(err, data){
        console.log(data); // data printed in console
    })
});

});

Happy to Help. by RTTSS.

Java String.split() Regex

str.split (" ") 
res27: Array[java.lang.String] = Array(a, +, b, -, c, *, d, /, e, <, f, >, g, >=, h, <=, i, ==, j)

How to enable remote access of mysql in centos?

Bind-address XXX.XX.XX.XXX in /etc/my.cnf

comment line:

skip-networking

or

skip-external-locking

after edit hit service mysqld restart

login into mysql and hit this query:

GRANT ALL PRIVILEGES ON dbname.* TO 'username'@'%' IDENTIFIED BY 'password';

FLUSH PRIVILEGES;
quit;

add firewall rule:

iptables -I INPUT -i eth0 -p tcp --destination-port 3306 -j ACCEPT

Going to a specific line number using Less in Unix

From within less (in Linux):

 g and the line number to go forward

 G and the line number to go backwards

Used alone, g and G will take you to the first and last line in a file respectively; used with a number they are both equivalent.

An example; you want to go to line 320123 of a file,

press 'g' and after the colon type in the number 320123

Additionally you can type '-N' inside less to activate / deactivate the line numbers. You can as a matter of fact pass any command line switches from inside the program, such as -j or -N.

NOTE: You can provide the line number in the command line to start less (less +number -N) which will be much faster than doing it from inside the program:

less +12345 -N /var/log/hugelogfile

This will open a file displaying the line numbers and starting at line 12345

Source: man 1 less and built-in help in less (less 418)

How to add element into ArrayList in HashMap

I know, this is an old question. But just for the sake of completeness, the lambda version.

Map<String, List<Item>> items = new HashMap<>();
items.computeIfAbsent(key, k -> new ArrayList<>()).add(item);

Liquibase lock - reasons?

I appreciate this wasn't the OP's issue, but I ran into this issue recently with a different cause. For reference, I was using the Liquibase Maven plugin (liquibase-maven-plugin:3.1.1) with SQL Server.

Anyway, I'd erroneously copied and pasted a SQL Server "use" statement into one of my scripts that switches databases, so liquibase was running and updating the DATABASECHANGELOGLOCK, acquiring the lock in the correct database, but then switching databases to apply the changes. Not only could I NOT see my changes or liquibase audit in the correct database, but of course, when I ran liquibase again, it couldn't acquire the lock, as the lock had been released in the "wrong" database, and so was still locked in the "correct" database. I'd have expected liquibase to check the lock was still applied before releasing it, and maybe that is a bug in liquibase (I haven't checked yet), but it may well be addressed in later versions! That said, I suppose it could be considered a feature!

Quite a bit of a schoolboy error, I know, but I raise it here in case anyone runs into the same problem!

HowTo Generate List of SQL Server Jobs and their owners

A colleague told me about this stored procedure...

USE msdb

EXEC dbo.sp_help_job

Wait until flag=true

Similar to Lightbeard's answer, I use the following approach

function sleep(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
}

async function until(fn) {
    while (!fn()) {
        await sleep(0)
    }
}

async function myFunction(number) {
    let x = number
    ...
    ... more initialization

    await until(() => flag == true)

    ...
    ... do something
}

How to set the font style to bold, italic and underlined in an Android TextView?

For bold and italic whatever you are doing is correct for underscore use following code

HelloAndroid.java

 package com.example.helloandroid;

 import android.app.Activity;
 import android.os.Bundle;
 import android.text.SpannableString;
 import android.text.style.UnderlineSpan;
import android.widget.TextView;

public class HelloAndroid extends Activity {
TextView textview;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    textview = (TextView)findViewById(R.id.textview);
    SpannableString content = new SpannableString(getText(R.string.hello));
    content.setSpan(new UnderlineSpan(), 0, content.length(), 0);
    textview.setText(content);
}
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/textview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="@string/hello"
android:textStyle="bold|italic"/>

string.xml

<?xml version="1.0" encoding="utf-8"?>
 <resources>
  <string name="hello">Hello World, HelloAndroid!</string>
  <string name="app_name">Hello, Android</string>
</resources>

Getting multiple selected checkbox values in a string in javascript and PHP

I you are using jQuery you can put the checkboxes in a form and then use something like this:

var formData = jQuery("#" + formId).serialize();

$.ajax({
      type: "POST",
      url: url,
      data: formData,
      success: success
}); 

Will iOS launch my app into the background if it was force-quit by the user?

The answer is YES, but shouldn't use 'Background Fetch' or 'Remote notification'. PushKit is the answer you desire.

In summary, PushKit, the new framework in ios 8, is the new push notification mechanism which can silently launch your app into the background with no visual alert prompt even your app was killed by swiping out from app switcher, amazingly you even cannot see it from app switcher.

PushKit reference from Apple:

The PushKit framework provides the classes for your iOS apps to receive pushes from remote servers. Pushes can be of one of two types: standard and VoIP. Standard pushes can deliver notifications just as in previous versions of iOS. VoIP pushes provide additional functionality on top of the standard push that is needed to VoIP apps to perform on-demand processing of the push before displaying a notification to the user.

To deploy this new feature, please refer to this tutorial: https://zeropush.com/guide/guide-to-pushkit-and-voip - I've tested it on my device and it works as expected.

How to convert a hex string to hex number

Try this:

hex_str = "0xAD4"
hex_int = int(hex_str, 16)
new_int = hex_int + 0x200
print hex(new_int)

If you don't like the 0x in the beginning, replace the last line with

print hex(new_int)[2:]

Use String.split() with multiple delimiters

s.trim().split("[\\W]+") 

should work.

Uploading a file in Rails

There is a nice gem especially for uploading files : carrierwave. If the wiki does not help , there is a nice RailsCast about the best way to use it . Summarizing , there is a field type file in Rails forms , which invokes the file upload dialog. You can use it , but the 'magic' is done by carrierwave gem .

I don't know what do you mean with "how to write to a file" , but I hope this is a nice start.

How to run python script in webpage

Well, OP didn't say server or client side, so i will just leave this here in case someone like me is looking for client side:

http://skulpt.org/using.html

Skulpt is a implementation of Python to run at client side. Very interesting, no plugin required, just a simple JS.

Forgot Oracle username and password, how to retrieve?

The usernames are shown in the dba_users's username column, there is a script you can run called:

alter user username identified by password

You can get more information here - https://community.oracle.com/thread/632617?tstart=0

Passing HTML to template using Flask/Jinja2

From the jinja docs section HTML Escaping:

When automatic escaping is enabled everything is escaped by default except for values explicitly marked as safe. Those can either be marked by the application or in the template by using the |safe filter.

Example:

 <div class="info">
   {{data.email_content|safe}}
 </div>

Calling Objective-C method from C++ member function?

Sometimes renaming .cpp to .mm is not good idea, especially when project is crossplatform. In this case for xcode project I open xcode project file throught TextEdit, found string which contents interest file, it should be like:

/* OnlineManager.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = OnlineManager.cpp; sourceTree = "<group>"; };

and then change file type from sourcecode.cpp.cpp to sourcecode.cpp.objcpp

/* OnlineManager.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = **sourcecode.cpp.objcpp**; path = OnlineManager.cpp; sourceTree = "<group>"; };

It is equivalent to rename .cpp to .mm

ipynb import another ipynb file

Install ipynb from your command prompt

pip install import-ipynb

Import in your notebook file

import import_ipynb

Now use regular import command to import your file

import MyOtherNotebook

Python: How exactly can you take a string, split it, reverse it and join it back together again?

Not fitting 100% to this particular question but if you want to split from the back you can do it like this:

theStringInQuestion[::-1].split('/', 1)[1][::-1]

This code splits once at symbol '/' from behind.

Reset all the items in a form

I recently had to do this for Textboxes and Checkboxes but using JavaScript ...

How to reset textbox and checkbox controls in an ASP.net document

Here is the code ...

<script src="http://code.jquery.com/jquery-1.7.1.js" type="text/javascript"></script>

<script type="text/javascript">
      function ResetForm() {
          //get the all the Input type elements in the document
          var AllInputsElements = document.getElementsByTagName('input');
          var TotalInputs = AllInputsElements.length;

          //we have to find the checkboxes and uncheck them
          //note: <asp:checkbox renders to <input type="checkbox" after compiling, which is why we use 'input' above
          for(var i=0;i< TotalInputs ; i++ )
          {
            if(AllInputsElements[i].type =='checkbox')
            {
                AllInputsElements[i].checked = false;
            }
          }

          //reset all textbox controls
          $('input[type=text], textarea').val('');

          Page_ClientValidateReset();
          return false;
      }

      //This function resets all the validation controls so that they don't "fire" up
      //during a post-back.
      function Page_ClientValidateReset() {
          if (typeof (Page_Validators) != "undefined") {
              for (var i = 0; i < Page_Validators.length; i++) {
                  var validator = Page_Validators[i];
                  validator.isvalid = true;
                  ValidatorUpdateDisplay(validator);
              }
          }
      }
</script>

And call it with a button or any other method ...

<asp:button id="btnRESET" runat="server" onclientclick="return ResetForm();" text="RESET" width="100px"></asp:button>

If you don't use ValidationControls on your website, just remove all the code refering to it above and the call Page_ClientValidateReset();

I am sure you can expand it for any other control using the DOM. And since there is no post to the server, it's faster and no "flashing" either.

How to check if an user is logged in Symfony2 inside a controller?

SecurityContext will be deprecated in Symfony 3.0

Prior to Symfony 2.6 you would use SecurityContext.
SecurityContext will be deprecated in Symfony 3.0 in favour of the AuthorizationChecker.

For Symfony 2.6+ & Symfony 3.0 use AuthorizationChecker.


Symfony 2.6 (and below)

// Get our Security Context Object - [deprecated in 3.0]
$security_context = $this->get('security.context');
# e.g: $security_context->isGranted('ROLE_ADMIN');

// Get our Token (representing the currently logged in user)
$security_token = $security_context->getToken();
# e.g: $security_token->getUser();
# e.g: $security_token->isAuthenticated();
# [Careful]             ^ "Anonymous users are technically authenticated"

// Get our user from that security_token
$user = $security_token->getUser();
# e.g: $user->getEmail(); $user->isSuperAdmin(); $user->hasRole();

// Check for Roles on the $security_context
$isRoleAdmin = $security_context->isGranted('ROLE_ADMIN');
# e.g: (bool) true/false

Symfony 3.0+ (and from Symfony 2.6+)

security.context becomes security.authorization_checker.
We now get our token from security.token_storage instead of the security.context

// [New 3.0] Get our "authorization_checker" Object
$auth_checker = $this->get('security.authorization_checker');
# e.g: $auth_checker->isGranted('ROLE_ADMIN');

// Get our Token (representing the currently logged in user)
// [New 3.0] Get the `token_storage` object (instead of calling upon `security.context`)
$token = $this->get('security.token_storage')->getToken();
# e.g: $token->getUser();
# e.g: $token->isAuthenticated();
# [Careful]            ^ "Anonymous users are technically authenticated"

// Get our user from that token
$user = $token->getUser();
# e.g (w/ FOSUserBundle): $user->getEmail(); $user->isSuperAdmin(); $user->hasRole();

// [New 3.0] Check for Roles on the $auth_checker
$isRoleAdmin = $auth_checker->isGranted('ROLE_ADMIN');
// e.g: (bool) true/false

Read more here in the docs: AuthorizationChecker
How to do this in twig?: Symfony 2: How do I check if a user is not logged in inside a template?

Is there a way to get the XPath in Google Chrome?

Just right-click on the element you want the xpath for and you will see a menu item to copy it. This may not have existed when the OP made his post but it's certainly there now.

Confused about Service vs Factory

live example

" hello world " example

with factory / service / provider :

var myApp = angular.module('myApp', []);
 
//service style, probably the simplest one
myApp.service('helloWorldFromService', function() {
    this.sayHello = function() {
        return "Hello, World!"
    };
});
 
//factory style, more involved but more sophisticated
myApp.factory('helloWorldFromFactory', function() {
    return {
        sayHello: function() {
            return "Hello, World!"
        }
    };
});
    
//provider style, full blown, configurable version     
myApp.provider('helloWorld', function() {
    // In the provider function, you cannot inject any
    // service or factory. This can only be done at the
    // "$get" method.
 
    this.name = 'Default';
 
    this.$get = function() {
        var name = this.name;
        return {
            sayHello: function() {
                return "Hello, " + name + "!"
            }
        }
    };
 
    this.setName = function(name) {
        this.name = name;
    };
});
 
//hey, we can configure a provider!            
myApp.config(function(helloWorldProvider){
    helloWorldProvider.setName('World');
});
        
 
function MyCtrl($scope, helloWorld, helloWorldFromFactory, helloWorldFromService) {
    
    $scope.hellos = [
        helloWorld.sayHello(),
        helloWorldFromFactory.sayHello(),
        helloWorldFromService.sayHello()];
}?

Detecting negative numbers

I assume that the main idea is to find if number is negative and display it in correct format.

For those who use PHP5.3 might be interested in using Number Formatter Class - http://php.net/manual/en/class.numberformatter.php. This function, as well as range of other useful things, can format your number.

$profitLoss = 25000 - 55000;

$a= new \NumberFormatter("en-UK", \NumberFormatter::CURRENCY); 
$a->formatCurrency($profitLoss, 'EUR');
// would display (€30,000.00)

Here also a reference to why brackets are used for negative numbers: http://www.open.edu/openlearn/money-management/introduction-bookkeeping-and-accounting/content-section-1.7

How do you find the sum of all the numbers in an array in Java?

I use this:

public static long sum(int[] i_arr)
{
    long sum;
    int i;
    for(sum= 0, i= i_arr.length - 1; 0 <= i; sum+= i_arr[i--]);
    return sum;
}

How to remove all whitespace from a string?

Another approach can be taken into account

library(stringr)
str_replace_all(" xx yy 11 22  33 ", regex("\\s*"), "")

#[1] "xxyy112233"

\\s: Matches Space, tab, vertical tab, newline, form feed, carriage return

*: Matches at least 0 times

SoapFault exception: Could not connect to host

In our case, it was a Ciphers negotiation problem. We were getting this error randomly. We solved our problem by forcing a Cipher like this:

$soapClient = new SoapClient ('http://example.com/soap.asmx?wsdl',
    array (
        "stream_context" => stream_context_create (
            array (
                'ssl' => array (
                    'ciphers'=>'AES256-SHA'
                )
            )
        )
    )
);

Looks like PHP wasn't negotiating the same Ciphers at each service call.

DevTools failed to load SourceMap: Could not load content for chrome-extension

include.prepload.js file will have a line something like below. probably as the last line.

//# sourceMappingURL=include.prepload.js.map

Delete it and the error will go away.

Best way to check if column returns a null value (from database to .net application)

Just check for

if(table.rows[0][0] == null)
{
     //Whatever I want to do
}

or you could

if(t.Rows[0].IsNull(0))
{
     //Whatever I want to do
}

Excel how to fill all selected blank cells with text

If all the cells are under one column, you could just filter the column and then select "(blank)" and then insert any value into the cells. But be careful, press "alt + 4" to make sure you are inserting value into the visible cells only.

rename the columns name after cbind the data

You can also name columns directly in the cbind call, e.g.

cbind(date=c(0,1), high=c(2,3))

Output:

     date high
[1,]    0    2
[2,]    1    3

WampServer: php-win.exe The program can't start because MSVCR110.dll is missing

Windows 10 x64 released August 2015 - same issue arising. MSVCR110.dll is also found in the sysWOW64 folder (which is where I found it, copying to system32 does not help). To resolve:

  1. uninstall the x86 versions of VC 11 vcredist_x64/86.exe for 2012 and 2013
  2. uninstall WAMP Server 2.5
  3. delete (maybe back up first) the WAMP folder
  4. restart windows
  5. reinstall WAMP 2.5

Hopefully like me you have a MySQL database backup handy!

CSS hexadecimal RGBA?

Use red, green, blue to convert to RGBA:

background-color: rgba(red($color), green($color), blue($color), 0.2);

Bundler::GemNotFound: Could not find rake-10.3.2 in any of the sources

Bundler 2

If you need to update from bundler v1 to v2 follow this official guide.

For a fast solution:

  1. In root fo your application run bundle config set path "/bundle" to add a custom path for bundler use, in this case I set /bundle, you can use whatever.

    1.2 [Alternative solution] You can use a bundler file (~/.bundle/config) also, to use this I recommend set bundler folders in environment, like a Docker image, for example. Here the official guide.

  2. You don't need to delete your Gemfile.lock, It's a bad practice and this can cause other future problems. Commit Gemfile.lock normaly, sometimes you need to update your bundle with bundle install or install individual gem.

You can see all the configs for bundler version 2 here.

C# equivalent to Java's charAt()?

You can index into a string in C# like an array, and you get the character at that index.

Example:

In Java, you would say

str.charAt(8);

In C#, you would say

str[8];

OperationalError: database is locked

I disagree with @Patrick's answer which, by quoting this doc, implicitly links OP's problem (Database is locked) to this:

Switching to another database backend. At a certain point SQLite becomes too "lite" for real-world applications, and these sorts of concurrency errors indicate you've reached that point.

This is a bit "too easy" to incriminate SQlite for this problem (which is very powerful when correctly used; it's not only a toy for small databases, fun fact: An SQLite database is limited in size to 140 terabytes).

Unless you have a very busy server with thousands of connections at the same second, the reason for this Database is locked error is probably more a bad use of the API, than a problem inherent to SQlite which would be "too light". Here are more informations about Implementation Limits for SQLite.


Now the solution:

I had the same problem when I was using two scripts using the same database at the same time:

  • one was accessing the DB with write operations
  • the other was accessing the DB in read-only

Solution: always do cursor.close() as soon as possible after having done a (even read-only) query.

Here are more details.

Apache Server (xampp) doesn't run on Windows 10 (Port 80)

I know that maybe this problem was resolved but I had the same problem with different solution. For that, I am going to explain another possible solution. In my case, the port 80 was occupied by Skype (pid: 25252) and I did not know what programme was.

To see the program's pid which is using the port 80 you can use the command that other people said before:

netstat -aon | findstr 0.0:80

To kill the process using the pid (in the case that you do not know the programme) you have to open the CMD with administrator permission and use the next command:

taskkill /pid 25252

Other options with this command are here.

Node.js global variables

You can just use the global object.

var X = ['a', 'b', 'c'];
global.x = X;

console.log(x);
//['a', 'b', 'c']

awk - concatenate two string variable and assign to a third

You can also concatenate strings from across multiple lines with whitespaces.

$ cat file.txt
apple 10
oranges 22
grapes 7

Example 1:

awk '{aggr=aggr " " $2} END {print aggr}' file.txt
10 22 7

Example 2:

awk '{aggr=aggr ", " $1 ":" $2} END {print aggr}' file.txt
, apple:10, oranges:22, grapes:7

How to query for today's date and 7 days before data?

Query in Parado's answer is correct, if you want to use MySql too instead GETDATE() you must use (because you've tagged this question with Sql server and Mysql):

select * from tab
where DateCol between adddate(now(),-7) and now() 

Remove columns from dataframe where ALL values are NA

df[sapply(df, function(x) all(is.na(x)))] <- NULL

How to install latest version of git on CentOS 7.x/6.x

If git already installed first remove old git

sudo yum remove git*

Add IUS CentOS 7 repo

sudo yum -y install  https://repo.ius.io/ius-release-el7.rpm
sudo yum -y install  git2u-all

Now check git version after installing git2u-all package. If docker is installed on your machine then ius-release may create problem.

git --version

bingo!!

How to get the list of all database users

For the SQL Server Owner, you should be able to use:

select suser_sname(owner_sid) as 'Owner', state_desc, *
from sys.databases

For a list of SQL Users:

select * from master.sys.server_principals

Ref. SQL Server Tip: How to find the owner of a database through T-SQL

How do you test for the existence of a user in SQL Server?

Build error: "The process cannot access the file because it is being used by another process"

I had this issue (and its an issue I have seen in other places not just VS).

It's caused by Dropbox (in my case). After editing some code and hitting run, sometimes dropbox immediately locks the file (so it can process it).

Solution 1. Just hit run again

Solution 2. Pause dropbox. (not good if your using dropbox as your cloud backup)

Solution 3. Remove the build folder from dropboxes sync list.

Why is String immutable in Java?

String class is FINAL it mean you can't create any class to inherit it and change the basic structure and make the Sting mutable.

Another thing instance variable and methods of String class that are provided are such that you can't change String object once created.

The reason what you have added doesn't make the String immutable at all.This all says how the String is stored in heap.Also string pool make the huge difference in performance

How can I return the difference between two lists?

If you only want find missing values in b, you can do:

List toReturn = new ArrayList(a);
toReturn.removeAll(b);

return toReturn;

If you want to find out values which are present in either list you can execute upper code twice. With changed lists.

Remove non-ascii character in string

None of these answers properly handle tabs, newlines, carriage returns, and some don't handle extended ASCII and unicode. This will KEEP tabs & newlines, but remove control characters and anything out of the ASCII set. Click "Run this code snippet" button to test. There is some new javascript coming down the pipe so in the future (2020+?) you may have to do \u{FFFFF} but not yet

_x000D_
_x000D_
console.log("line 1\nline2 \n\ttabbed\nF??^?¯?^??????????????l????~¨??????_??????a?????"????????????v?¯?????i????o?????????????????????".replace(/[\x00-\x08\x0E-\x1F\x7F-\uFFFF]/g, ''))
_x000D_
_x000D_
_x000D_

SQL count rows in a table

The index statistics likely need to be current, but this will return the number of rows for all tables that are not MS_SHIPPED.

select o.name, i.rowcnt 
from sys.objects o join sys.sysindexes i 
on o.object_id = i.id
where o.is_ms_shipped = 0
and i.rowcnt > 0
order by o.name

How to configure Glassfish Server in Eclipse manually

To use Glassfish tools with Eclipse Luna you need Java 8. I also faced this problem because I had Java 7. If you have Java 7 in your environment then download eclipse Kepler. It will work fine.

Failed to resolve: com.google.firebase:firebase-core:16.0.1

Add maven { url "https://maven.google.com" } to your root level build.gradle file

repositories {
    maven { url "https://maven.google.com" }
    flatDir {
        dirs 'libs'
    }
}

How to remove item from list in C#?

Short answer:
Remove (from list results)

results.RemoveAll(r => r.ID == 2); will remove the item with ID 2 in results (in place).

Filter (without removing from original list results):

var filtered = result.Where(f => f.ID != 2); returns all items except the one with ID 2

Detailed answer:

I think .RemoveAll() is very flexible, because you can have a list of item IDs which you want to remove - please regard the following example.

If you have:

class myClass {
    public int ID; public string FirstName; public string LastName;
}

and assigned some values to results as follows:

var results = new List<myClass> {
    new myClass { ID=1, FirstName="Bill", LastName="Smith" },   // results[0]
    new myClass { ID=2, FirstName="John", LastName="Wilson" },  // results[1]
    new myClass { ID=3, FirstName="Doug", LastName="Berg" },    // results[2]
    new myClass { ID=4, FirstName="Bill", LastName="Wilson" }   // results[3]
};

Then you can define a list of IDs to remove:

var removeList = new List<int>() { 2, 3 };

And simply use this to remove them:

results.RemoveAll(r => removeList.Any(a => a==r.ID));

It will remove the items 2 and 3 and keep the items 1 and 4 - as specified by the removeList. Note that this happens in place, so there is no additional assigment required.

Of course, you can also use it on single items like:

results.RemoveAll(r => r.ID==4);

where it will remove Bill with ID 4 in our example.

A last thing to mention is that lists have an indexer, that is, they can also be accessed like a dynamic array, i.e. results[3] will give you the 4th element in the results list (because the first element has the index 0, the 2nd has index 1 etc).

So if you want to remove all entries where the first name is the same as in the 4th element of the results list, you can simply do it this way:

results.RemoveAll(r => results[3].FirstName == r.FirstName);

Note that afterwards, only John and Doug will remain in the list, Bill is removed (the first and last element in the example). Important is that the list will shrink automatically, so it has only 2 elements left - and hence the largest allowed index after executing RemoveAll in this example is 1
(which is results.Count() - 1).

Some Trivia: You can use this knowledge and create a local function

void myRemove()  { var last = results.Count() - 1; 
                   results.RemoveAll(r => results[last].FirstName == r.FirstName); }

What do you think will happen, if you call this function twice? Like

myRemove(); myRemove(); 

The first call will remove Bill at the first and last position, the second call will remove Doug and only John Wilson remains in the list.


DotNetFiddle: Run the demo

Note: Since C# Version 8, you can as well write results[^1] instead of var last = results.Count() - 1; and results[last]:

void myRemove() { results.RemoveAll(r => results[^1].FirstName == r.FirstName); }

So you would not need the local variable last anymore (see indices and ranges. For a list of all the new features in C#, look here).

MATLAB - multiple return values from a function?

Use the following in the function you will call and it will work just fine.

     [a b c] = yourfunction(optional)
     %your code
     a = 5;
     b = 7;
     c = 10;
     return
     end

This is a way to call the function both from another function and from the command terminal

     [aa bb cc] = yourfunction(optional);

The variables aa, bb and cc now hold the return variables.

Shell script to set environment variables

You need to run the script as source or the shorthand .

source ./myscript.sh

or

. ./myscript.sh

This will run within the existing shell, ensuring any variables created or modified by the script will be available after the script completes.

Running the script just using the filename will execute the script in a separate subshell.

MemoryStream - Cannot access a closed Stream

The problem is this block:

using (var sr = new StreamReader(ms))
{
    Console.WriteLine(sr.ReadToEnd());                        
}

When the StreamReader is closed (after leaving the using), it closes it's underlying stream as well, so now the MemoryStream is closed. When the StreamWriter gets closed, it tries to flush everything to the MemoryStream, but it is closed.

You should consider not putting the StreamReader in a using block.

Cannot find module '@angular/compiler'

Uninstall the Angular CLI and install the latest version of it.

npm uninstall angular-cli

npm install --save-dev @angular/cli@latest

jQuery autohide element after 5 seconds

You can try :

setTimeout(function() {
  $('#successMessage').fadeOut('fast');
}, 30000); // <-- time in milliseconds

If you used this then your div will be hide after 30 sec.I also tried this one and it worked for me.

Creating a file name as a timestamp in a batch job

Here is a locale independent solution (copy to a file named SetDateTimeComponents.cmd):

@echo off
REM This script taken from the following URL:
REM http://www.winnetmag.com/windowsscripting/article/articleid/9177/windowsscripting_9177.html

REM Create the date and time elements.
for /f "tokens=1-7 delims=:/-, " %%i in ('echo exit^|cmd /q /k"prompt $d $t"') do (
   for /f "tokens=2-4 delims=/-,() skip=1" %%a in ('echo.^|date') do (
      set dow=%%i
      set %%a=%%j
      set %%b=%%k
      set %%c=%%l
      set hh=%%m
      set min=%%n
      set ss=%%o
   )
)

REM Let's see the result.
echo %dow% %yy%-%mm%-%dd% @ %hh%:%min%:%ss%

I put all my .cmd scripts into the same folder (%SCRIPTROOT%); any script that needs date/time values will call SetDateTimeComponents.cmd as in the following example:

setlocal

@echo Initializing...
set SCRIPTROOT=%~dp0
set ERRLOG=C:\Oopsies.err

:: Log start time
call "%SCRIPTROOT%\SetDateTimeComponents.cmd" >nul
@echo === %dow% %yy%-%mm%-%dd% @ %hh%:%min%:%ss% : Start === >> %ERRLOG%

:: Perform some long running action and log errors to ERRLOG.

:: Log end time
call "%SCRIPTROOT%\SetDateTimeComponents.cmd" >nul
@echo === %dow% %yy%-%mm%-%dd% @ %hh%:%min%:%ss% : End === >> %ERRLOG%

As the example shows, you can call SetDateTimeComponents.cmd whenever you need to update the date/time values. Hiding the time parsing script in it's own SetDateTimeComponents.cmd file is a nice way to hide the ugly details, and, more importantly, avoid typos.

Search and replace a particular string in a file using Perl

Quick and dirty:

#!/usr/bin/perl -w

use strict;

open(FILE, "</tmp/yourfile.txt") || die "File not found";
my @lines = <FILE>;
close(FILE);

foreach(@lines) {
   $_ =~ s/<PREF>/ABCD/g;
}

open(FILE, ">/tmp/yourfile.txt") || die "File not found";
print FILE @lines;
close(FILE);

Perhaps it i a good idea not to write the result back to your original file; instead write it to a copy and check the result first.

How to determine the version of Gradle?

2019-05-08 Android Studios needs an upgrade. upgrade Android Studios to 3.3.- and the error with .R; goes away.

Also the above methods also work.

ajax jquery simple get request

var dataString = "flag=fetchmediaaudio&id="+id;

$.ajax
({
  type: "POST",
  url: "ajax.php",
  data: dataString,
  success: function(html)
  {
     alert(html);
  }
});

Renaming column names of a DataFrame in Spark Scala

def aliasAllColumns(t: DataFrame, p: String = "", s: String = ""): DataFrame =
{
  t.select( t.columns.map { c => t.col(c).as( p + c + s) } : _* )
}

In case is isn't obvious, this adds a prefix and a suffix to each of the current column names. This can be useful when you have two tables with one or more columns having the same name, and you wish to join them but still be able to disambiguate the columns in the resultant table. It sure would be nice if there were a similar way to do this in "normal" SQL.

How do I filter ForeignKey choices in a Django ModelForm?

To do this with a generic view, like CreateView...

class AddPhotoToProject(CreateView):
    """
    a view where a user can associate a photo with a project
    """
    model = Connection
    form_class = CreateConnectionForm


    def get_context_data(self, **kwargs):
        context = super(AddPhotoToProject, self).get_context_data(**kwargs)
        context['photo'] = self.kwargs['pk']
        context['form'].fields['project'].queryset = Project.objects.for_user(self.request.user)
        return context
    def form_valid(self, form):
        pobj = Photo.objects.get(pk=self.kwargs['pk'])
        obj = form.save(commit=False)
        obj.photo = pobj
        obj.save()

        return_json = {'success': True}

        if self.request.is_ajax():

            final_response = json.dumps(return_json)
            return HttpResponse(final_response)

        else:

            messages.success(self.request, 'photo was added to project!')
            return HttpResponseRedirect(reverse('MyPhotos'))

the most important part of that...

    context['form'].fields['project'].queryset = Project.objects.for_user(self.request.user)

, read my post here

iPhone 5 CSS media query

Another useful media feature is device-aspect-ratio.

Note that the iPhone 5 does not have a 16:9 aspect ratio. It is in fact 40:71.

iPhone < 5:
@media screen and (device-aspect-ratio: 2/3) {}

iPhone 5:
@media screen and (device-aspect-ratio: 40/71) {}

iPhone 6:
@media screen and (device-aspect-ratio: 375/667) {}

iPhone 6 Plus:
@media screen and (device-aspect-ratio: 16/9) {}

iPad:
@media screen and (device-aspect-ratio: 3/4) {}

Reference:
Media Queries @ W3C
iPhone Model Comparison
Aspect Ratio Calculator

Java output formatting for Strings

System.out.println(String.format("%-20s= %s" , "label", "content" ));
  • Where %s is a placeholder for you string.
  • The '-' makes the result left-justified.
  • 20 is the width of the first string

The output looks like this:

label               = content

As a reference I recommend Javadoc on formatter syntax

Javascript: Unicode string to hex

Remember that a JavaScript code unit is 16 bits wide. Therefore the hex string form will be 4 digits per code unit.

usage:

var str = "\u6f22\u5b57"; // "\u6f22\u5b57" === "??"
alert(str.hexEncode().hexDecode());

String to hex form:

String.prototype.hexEncode = function(){
    var hex, i;

    var result = "";
    for (i=0; i<this.length; i++) {
        hex = this.charCodeAt(i).toString(16);
        result += ("000"+hex).slice(-4);
    }

    return result
}

Back again:

String.prototype.hexDecode = function(){
    var j;
    var hexes = this.match(/.{1,4}/g) || [];
    var back = "";
    for(j = 0; j<hexes.length; j++) {
        back += String.fromCharCode(parseInt(hexes[j], 16));
    }

    return back;
}

git - remote add origin vs remote set-url origin

if you have existing project and you would like to add remote repository url then you need to do following command

git init

if you would like to add readme.md file then you can create it and add it using below command.

git add README.md

make your first commit using below command

git commit -m "first commit"

Now you completed all local repository process, now how you add remote repository url ? check below command this is for ssh url, you can change it for https.

git remote add origin [email protected]:user-name/repository-name.git

How you push your first commit see below command :

git push -u origin master

Android ADB doesn't see device

Not all USB cables can transfer data. Try using a different USB cable if your device is charging, but doesn't establish a connection to your machine.

It seems trivial. But it's worth a try if each and every other solution that normally works, doesn't.

The HTTP request is unauthorized with client authentication scheme 'Ntlm'. The authentication header received from the server was 'Negotiate,NTLM'

If both your client and service is installed on the same machine, and you are facing this problem with the correct (read: tried and tested elsewhere) client and service configurations, then this might be worth checking.

Check host entries in your host file

%windir%/system32/drivers/etc/hosts

Check to see if you are accessing your web service with a hostname, and that same hostname has been associated with an IP address in the hosts file mentioned above. If yes, NTLM/Windows credentials will NOT be passed from the client to the service as any request for that hostname will be routed again at the machine level.

Try either of the following

  • Remove the host entry of that hostname from the hosts file
  • OR
  • If removing host entry is not possible, then try accessing your service with another hostname. You might also try with IP address instead of hostname

Edit: Somehow the above situation is relevant on a load-balanced scenario. However, if removing the host entries is not possible, then disabling loop back check on the machine will help. Refer method 2 in the article https://support.microsoft.com/en-us/kb/896861

CSS: how to position element in lower right?

Set the CSS position: relative; on the box. This causes all absolute positions of objects inside to be relative to the corners of that box. Then set the following CSS on the "Bet 5 days ago" line:

position: absolute;
bottom: 0;
right: 0;

If you need to space the text farther away from the edge, you could change 0 to 2px or similar.