Programs & Examples On #Filesystems

A file system is a way of organizing data on a computer system. Typically a file system consists of files, folders (normally a special kind of file) and an API that can be used for interacting with files.

Get size of folder or file

in linux if you want to sort directories then du -hs * | sort -h

Determine file creation date in Java

This is a basic example of how to get the creation date of a file in Java, using BasicFileAttributes class:

   Path path = Paths.get("C:\\Users\\jorgesys\\workspaceJava\\myfile.txt");
    BasicFileAttributes attr;
    try {
    attr = Files.readAttributes(path, BasicFileAttributes.class);
    System.out.println("Creation date: " + attr.creationTime());
    //System.out.println("Last access date: " + attr.lastAccessTime());
    //System.out.println("Last modified date: " + attr.lastModifiedTime());
    } catch (IOException e) {
    System.out.println("oops error! " + e.getMessage());
}

fs: how do I locate a parent folder?

If you not positive on where the parent is, this will get you the path;

var path = require('path'),
    __parentDir = path.dirname(module.parent.filename);

fs.readFile(__parentDir + '/foo.bar');

How do I find the mime-type of a file with php?

mime_content_type() is deprecated, so you won't be able to count on it working in the future. There is a "fileinfo" PECL extension, but I haven't heard good things about it.

If you are running on a *nix server, you can do the following, which has worked fine for me:

$file = escapeshellarg( $filename );
$mime = shell_exec("file -bi " . $file);
$filename should probably include the absolute path.

Python causing: IOError: [Errno 28] No space left on device: '../results/32766.html' on disk with lots of space

In my case, when I run df -i it shows me that my number of inodes are full and then I have to delete some of the small files or folder. Otherwise it will not allow us to create files or folders once inodes get full.

All you have to do is delete files or folder that has not taken up full space but is responsible for filling inodes.

Has Windows 7 Fixed the 255 Character File Path Limit?

Workarounds are not solutions, therefore the answer is "No".

Still looking for workarounds, here are possible solutions: http://support.code42.com/CrashPlan/Latest/Troubleshooting/Windows_File_Paths_Longer_Than_255_Characters

How can I determine whether a specific file is open in Windows?

Try Unlocker.

The Unlocker site has a nifty chart (scroll down after following the link) that shows a comparison to other tools. Obviously such comparisons are usually biased since they are typically written by the tool author, but the chart at least lists the alternatives so that you can try them for yourself.

How to get a path to the desktop for current user in C#?

string path = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);

How do you iterate through every file/directory recursively in standard C++?

If you are on Windows, you can use the FindFirstFile together with FindNextFile API. You can use FindFileData.dwFileAttributes to check if a given path is a file or a directory. If it's a directory, you can recursively repeat the algorithm.

Here, I have put together some code that lists all the files on a Windows machine.

http://dreams-soft.com/projects/traverse-directory

Iterate through every file in one directory

Dir has also shorter syntax to get an array of all files from directory:

Dir['dir/to/files/*'].each do |fname|
    # do something with fname
end

Can you call Directory.GetFiles() with multiple filters?

There is also a descent solution which seems not to have any memory or performance overhead and be quite elegant:

string[] filters = new[]{"*.jpg", "*.png", "*.gif"};
string[] filePaths = filters.SelectMany(f => Directory.GetFiles(basePath, f)).ToArray();

Trying to create a file in Android: open failed: EROFS (Read-only file system)

I have tried this with and without the WRITE_INTERNAL_STORAGE permission.

There is no WRITE_INTERNAL_STORAGE permission in Android.

How do I create this file for writing?

You don't, except perhaps on a rooted device, if your app is running with superuser privileges. You are trying to write to the root of internal storage, which apps do not have access to.

Please use the version of the FileOutputStream constructor that takes a File object. Create that File object based off of some location that you can write to, such as:

  • getFilesDir() (called on your Activity or other Context)
  • getExternalFilesDir() (called on your Activity or other Context)

The latter will require WRITE_EXTERNAL_STORAGE as a permission.

Is there an easier way than writing it to a file then reading from it again?

You can temporarily put it in a static data member.

because many people don't have SD card slots

"SD card slots" are irrelevant, by and large. 99% of Android device users will have external storage -- the exception will be 4+ year old devices where the user removed their SD card. Devices manufactured since mid-2010 have external storage as part of on-board flash, not as removable media.

Open directory dialog

The Ookii VistaFolderBrowserDialog is the one you want.

If you only want the Folder Browser from Ooki Dialogs and nothing else then download the Source, cherry-pick the files you need for the Folder browser (hint: 7 files) and it builds fine in .NET 4.5.2. I had to add a reference to System.Drawing. Compare the references in the original project to yours.

How do you figure out which files? Open your app and Ookii in different Visual Studio instances. Add VistaFolderBrowserDialog.cs to your app and keep adding files until the build errors go away. You find the dependencies in the Ookii project - Control-Click the one you want to follow back to its source (pun intended).

Here are the files you need if you're too lazy to do that ...

NativeMethods.cs
SafeHandles.cs
VistaFolderBrowserDialog.cs
\ Interop
   COMGuids.cs
   ErrorHelper.cs
   ShellComInterfaces.cs
   ShellWrapperDefinitions.cs

Edit line 197 in VistaFolderBrowserDialog.cs unless you want to include their Resources.Resx

throw new InvalidOperationException(Properties.Resources.FolderBrowserDialogNoRootFolder);

throw new InvalidOperationException("Unable to retrieve the root folder.");

Add their copyright notice to your app as per their license.txt

The code in \Ookii.Dialogs.Wpf.Sample\MainWindow.xaml.cs line 160-169 is an example you can use but you will need to remove this, from MessageBox.Show(this, for WPF.

Works on My Machine [TM]

Get an image extension from an uploaded file in Laravel

Do something like this:

if($request->hasFile('video')){

    $video=$request->file('video');
    $filename=str_random(20).".".$video->extension(); 
    $path = Storage::putFileAs(
            '/', $video, $filename
     );
    $data['video']=$filename;
 }

How do I include a file over 2 directories back?

Try This

this example is one directory back

require_once('../images/yourimg.png');

this example is two directory back

require_once('../../images/yourimg.png');

NTFS performance and large volumes of files and directories

When you create a folder with N entries, you create a list of N items at file-system level. This list is a system-wide shared data structure. If you then start modifying this list continuously by adding/removing entries, I expect at least some lock contention over shared data. This contention - theoretically - can negatively affect performance.

For read-only scenarios I can't imagine any reason for performance degradation of directories with large number of entries.

Node.js - Find home directory in platform agnostic way

os.homedir() was added by this PR and is part of the public 4.0.0 release of nodejs.


Example usage:

const os = require('os');

console.log(os.homedir());

How can I find all of the distinct file extensions in a folder hierarchy?

In Python using generators for very large directories, including blank extensions, and getting the number of times each extension shows up:

import json
import collections
import itertools
import os

root = '/home/andres'
files = itertools.chain.from_iterable((
    files for _,_,files in os.walk(root)
    ))
counter = collections.Counter(
    (os.path.splitext(file_)[1] for file_ in files)
)
print json.dumps(counter, indent=2)

Wait Until File Is Completely Written

I would like to add an answer here, because this worked for me. I used time delays, while loops, everything I could think of.

I had the Windows Explorer window of the output folder open. I closed it, and everything worked like a charm.

I hope this helps someone.

Most efficient way to check if a file is empty in Java on Windows

Try FileReader, this reader is meant to read stream of character, while FileInputStream is meant to read raw data.

From the Javadoc:

FileReader is meant for reading streams of characters. For reading streams of raw bytes, consider using a FileInputStream.

Since you wanna read a log file, FileReader is the class to use IMO.

Node.js check if path is file or directory

The following should tell you. From the docs:

fs.lstatSync(path_string).isDirectory() 

Objects returned from fs.stat() and fs.lstat() are of this type.

stats.isFile()
stats.isDirectory()
stats.isBlockDevice()
stats.isCharacterDevice()
stats.isSymbolicLink() (only valid with fs.lstat())
stats.isFIFO()
stats.isSocket()

NOTE:

The above solution will throw an Error if; for ex, the file or directory doesn't exist.

If you want a true or false approach, try fs.existsSync(dirPath) && fs.lstatSync(dirPath).isDirectory(); as mentioned by Joseph in the comments below.

SQLite3 database or disk is full / the database disk image is malformed

Cloning the current database from the sqlite3 commandline worked for me.

.open /path/to/database/corrupted_database.sqlite3
.clone /path/to/database/new_database.sqlite3

In the Django setting file change the database name

DATABASES = {
'default': {
    'ENGINE': 'django.db.backends.sqlite3',
    'NAME': os.path.join(BASE_DIR, 'new_database.sqlite3'),
}}

Notepad++ cached files location

I lost somehow my temporary notepad++ files, they weren't showing in tabs. So I did some search in appdata folder, and I found all my temporary files there. It seems that they are stored there for a long time.

C:\Users\USER\AppData\Roaming\Notepad++\backup

or

%AppData%\Notepad++\backup

How to recursively find and list the latest modified files in a directory with subdirectories and times

The following returns you a string of the timestamp and the name of the file with the most recent timestamp:

find $Directory -type f -printf "%TY-%Tm-%Td-%TH-%TM-%TS %p\n" | sed -r 's/([[:digit:]]{2})\.([[:digit:]]{2,})/\1-\2/' |     sort --field-separator='-' -nrk1 -nrk2 -nrk3 -nrk4 -nrk5 -nrk6 -nrk7 | head -n 1

Resulting in an output of the form: <yy-mm-dd-hh-mm-ss.nanosec> <filename>

How do I find the parent directory in C#?

Since nothing else I have found helps to solve this in a truly normalized way, here is another answer.

Note that some answers to similar questions try to use the Uri type, but that struggles with trailing slashes vs. no trailing slashes too.

My other answer on this page works for operations that put the file system to work, but if we want to have the resolved path right now (such as for comparison reasons), without going through the file system, C:/Temp/.. and C:/ would be considered different. Without going through the file system, navigating in that manner does not provide us with a normalized, properly comparable path.

What can we do?

We will build on the following discovery:

Path.GetDirectoryName(path + "/") ?? "" will reliably give us a directory path without a trailing slash.

  • Adding a slash (as string, not as char) will treat a null path the same as it treats "".
  • GetDirectoryName will refrain from discarding the last path component thanks to the added slash.
  • GetDirectoryName will normalize slashes and navigational dots.
  • This includes the removal of any trailing slashes.
  • This includes collapsing .. by navigating up.
  • GetDirectoryName will return null for an empty path, which we coalesce to "".

How do we use this?

First, normalize the input path:

dirPath = Path.GetDirectoryName(dirPath + "/") ?? "";

Then, we can get the parent directory, and we can repeat this operation any number of times to navigate further up:

// This is reliable if path results from this or the previous operation
path = Path.GetDirectoryName(path);

Note that we have never touched the file system. No part of the path needs to exist, as it would if we had used DirectoryInfo.

How to copy a file from one directory to another using PHP?

copy will do this. Please check the php-manual. Simple Google search should answer your last two questions ;)

copy all files and folders from one drive to another drive using DOS (command prompt)

xcopy "C:\SomeFolderName" "D:\SomeFolderName" /h /i /c /k /e /r /y

Use the above command. It will definitely work.

In this command data will be copied from c:\ to D:\, even folders and system files as well. Here's what the flags do:

  • /h copies hidden and system files also
  • /i if destination does not exist and copying more than one file, assume that destination must be a directory
  • /c continue copying even if error occurs
  • /k copies attributes
  • /e copies directories and subdirectories, including empty ones
  • /r overwrites read-only files
  • /y suppress prompting to confirm whether you want to overwrite a file

Check whether a path is valid in Python without creating a file at the path's target

With Python 3, how about:

try:
    with open(filename, 'x') as tempfile: # OSError if file exists or is invalid
        pass
except OSError:
    # handle error here

With the 'x' option we also don't have to worry about race conditions. See documentation here.

Now, this WILL create a very shortlived temporary file if it does not exist already - unless the name is invalid. If you can live with that, it simplifies things a lot.

Getting the folder name from a path

Simple & clean. Only uses System.IO.FileSystem - works like a charm:

string path = "C:/folder1/folder2/file.txt";
string folder = new DirectoryInfo(path).Name;

How to get directory size in PHP

Just another function using native php functions.

function dirSize($dir)
    {
        $dirSize = 0;
        if(!is_dir($dir)){return false;};
        $files = scandir($dir);if(!$files){return false;}
        $files = array_diff($files, array('.','..'));

        foreach ($files as $file) {
            if(is_dir("$dir/$file")){
                 $dirSize += dirSize("$dir/$file");
            }else{
                $dirSize += filesize("$dir/$file");
            }
        }
        return $dirSize;
    }

NOTE: this function returns the files sizes, NOT the size on disk

best way to get folder and file list in Javascript

I don't like adding new package into my project just to handle this simple task.

And also, I try my best to avoid RECURSIVE algorithm.... since, for most cases it is slower compared to non Recursive one.

So I made a function to get all the folder content (and its sub folder).... NON-Recursively

var getDirectoryContent = function(dirPath) {
    /* 
        get list of files and directories from given dirPath and all it's sub directories
        NON RECURSIVE ALGORITHM
        By. Dreamsavior
    */
    var RESULT = {'files':[], 'dirs':[]};

    var fs = fs||require('fs');
    if (Boolean(dirPath) == false) {
        return RESULT;
    }
    if (fs.existsSync(dirPath) == false) {
        console.warn("Path does not exist : ", dirPath);
        return RESULT;
    }

    var directoryList = []
    var DIRECTORY_SEPARATOR = "\\";
    if (dirPath[dirPath.length -1] !== DIRECTORY_SEPARATOR) dirPath = dirPath+DIRECTORY_SEPARATOR;

    directoryList.push(dirPath); // initial

    while (directoryList.length > 0) {
        var thisDir  = directoryList.shift(); 
        if (Boolean(fs.existsSync(thisDir) && fs.lstatSync(thisDir).isDirectory()) == false) continue;

        var thisDirContent = fs.readdirSync(thisDir);
        while (thisDirContent.length > 0) { 
            var thisFile  = thisDirContent.shift(); 
            var objPath = thisDir+thisFile

            if (fs.existsSync(objPath) == false) continue;
            if (fs.lstatSync(objPath).isDirectory()) { // is a directory
                let thisDirPath = objPath+DIRECTORY_SEPARATOR; 
                directoryList.push(thisDirPath);
                RESULT['dirs'].push(thisDirPath);

            } else  { // is a file
                RESULT['files'].push(objPath); 

            } 
        } 

    }
    return RESULT;
}

the only drawback of this function is that this is Synchronous function... You have been warned ;)

Quickly create a large file on a Linux system

You can use "yes" command also. The syntax is fairly simple:

#yes >> myfile

Press "Ctrl + C" to stop this, else it will eat up all your space available.

To clean this file run:

#>myfile

will clean this file.

How to check type of files without extensions in python?

In the case of images, you can use the imghdr module.

>>> import imghdr
>>> imghdr.what('8e5d7e9d873e2a9db0e31f9dfc11cf47')  # You can pass a file name or a file object as first param. See doc for optional 2nd param.
'png'

Python 2 imghdr doc
Python 3 imghdr doc

Server.MapPath("."), Server.MapPath("~"), Server.MapPath(@"\"), Server.MapPath("/"). What is the difference?

1) Server.MapPath(".") -- Returns the "Current Physical Directory" of the file (e.g. aspx) being executed.

Ex. Suppose D:\WebApplications\Collage\Departments

2) Server.MapPath("..") -- Returns the "Parent Directory"

Ex. D:\WebApplications\Collage

3) Server.MapPath("~") -- Returns the "Physical Path to the Root of the Application"

Ex. D:\WebApplications\Collage

4) Server.MapPath("/") -- Returns the physical path to the root of the Domain Name

Ex. C:\Inetpub\wwwroot

Loop code for each file in a directory

Try GLOB()

$dir = "/etc/php5/*";  

// Open a known directory, and proceed to read its contents  
foreach(glob($dir) as $file)  
{  
    echo "filename: $file : filetype: " . filetype($file) . "<br />";  
}  

How to recursively find the latest modified file in a directory?

I use something similar all the time, as well as the top-k list of most recently modified files. For large directory trees, it can be much faster to avoid sorting. In the case of just top-1 most recently modified file:

find . -type f -printf '%T@ %p\n' | perl -ne '@a=split(/\s+/, $_, 2); ($t,$f)=@a if $a[0]>$t; print $f if eof()'

On a directory containing 1.7 million files, I get the most recent one in 3.4s, a speed-up of 7.5x against the 25.5s solution using sort.

Storing a file in a database as opposed to the file system?

While performance is an issue, I think modern database designs have made it much less of an issue for small files.

Performance aside, it also depends on just how tightly-coupled the data is. If the file contains data that is closely related to the fields of the database, then it conceptually belongs close to it and may be stored in a blob. If it contains information which could potentially relate to multiple records or may have some use outside of the context of the database, then it belongs outside. For example, an image on a web page is fetched on a separate request from the page that links to it, so it may belong outside (depending on the specific design and security considerations).

Our compromise, and I don't promise it's the best, has been to store smallish XML files in the database but images and other files outside it.

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

import os

def get_mount_point(pathname):
    "Get the mount point of the filesystem containing pathname"
    pathname= os.path.normcase(os.path.realpath(pathname))
    parent_device= path_device= os.stat(pathname).st_dev
    while parent_device == path_device:
        mount_point= pathname
        pathname= os.path.dirname(pathname)
        if pathname == mount_point: break
        parent_device= os.stat(pathname).st_dev
    return mount_point

def get_mounted_device(pathname):
    "Get the device mounted at pathname"
    # uses "/proc/mounts"
    pathname= os.path.normcase(pathname) # might be unnecessary here
    try:
        with open("/proc/mounts", "r") as ifp:
            for line in ifp:
                fields= line.rstrip('\n').split()
                # note that line above assumes that
                # no mount points contain whitespace
                if fields[1] == pathname:
                    return fields[0]
    except EnvironmentError:
        pass
    return None # explicit

def get_fs_freespace(pathname):
    "Get the free space of the filesystem containing pathname"
    stat= os.statvfs(pathname)
    # use f_bfree for superuser, or f_bavail if filesystem
    # has reserved space for superuser
    return stat.f_bfree*stat.f_bsize

Some sample pathnames on my computer:

path 'trash':
  mp /home /dev/sda4
  free 6413754368
path 'smov':
  mp /mnt/S /dev/sde
  free 86761562112
path '/usr/local/lib':
  mp / rootfs
  free 2184364032
path '/proc/self/cmdline':
  mp /proc proc
  free 0

PS

if on Python =3.3, there's shutil.disk_usage(path) which returns a named tuple of (total, used, free) expressed in bytes.

How to list only top level directories in Python?

Filter the list using os.path.isdir to detect directories.

filter(os.path.isdir, os.listdir(os.getcwd()))

nodejs - How to read and output jpg image?

Here is how you can read the entire file contents, and if done successfully, start a webserver which displays the JPG image in response to every request:

var http = require('http')
var fs = require('fs')

fs.readFile('image.jpg', function(err, data) {
  if (err) throw err // Fail if the file can't be read.
  http.createServer(function(req, res) {
    res.writeHead(200, {'Content-Type': 'image/jpeg'})
    res.end(data) // Send the file data to the browser.
  }).listen(8124)
  console.log('Server running at http://localhost:8124/')
})

Note that the server is launched by the "readFile" callback function and the response header has Content-Type: image/jpeg.

[Edit] You could even embed the image in an HTML page directly by using an <img> with a data URI source. For example:

  res.writeHead(200, {'Content-Type': 'text/html'});
  res.write('<html><body><img src="data:image/jpeg;base64,')
  res.write(Buffer.from(data).toString('base64'));
  res.end('"/></body></html>');

Internal and external fragmentation

I am an operating system that only allocates you memory in 10mb partitions.

Internal Fragmentation

  • You ask for 17mb of memory
  • I give you 20mb of memory

Fulfilling this request has just led to 3mb of internal fragmentation.

External Fragmentation

  • You ask for 20mb of memory
  • I give you 20mb of memory
  • The 20mb of memory that I give you is not immediately contiguous next to another existing piece of allocated memory. In so handing you this memory, I have "split" a single unallocated space into two spaces.

Fulfilling this request has just led to external fragmentation

What is the difference between VFAT and FAT32 file systems?

Copied from http://technet.microsoft.com/en-us/library/cc750354.aspx

What's FAT?

FAT may sound like a strange name for a file system, but it's actually an acronym for File Allocation Table. Introduced in 1981, FAT is ancient in computer terms. Because of its age, most operating systems, including Microsoft Windows NT®, Windows 98, the Macintosh OS, and some versions of UNIX, offer support for FAT.

The FAT file system limits filenames to the 8.3 naming convention, meaning that a filename can have no more than eight characters before the period and no more than three after. Filenames in a FAT file system must also begin with a letter or number, and they can't contain spaces. Filenames aren't case sensitive.

What About VFAT?

Perhaps you've also heard of a file system called VFAT. VFAT is an extension of the FAT file system and was introduced with Windows 95. VFAT maintains backward compatibility with FAT but relaxes the rules. For example, VFAT filenames can contain up to 255 characters, spaces, and multiple periods. Although VFAT preserves the case of filenames, it's not considered case sensitive.

When you create a long filename (longer than 8.3) with VFAT, the file system actually creates two different filenames. One is the actual long filename. This name is visible to Windows 95, Windows 98, and Windows NT (4.0 and later). The second filename is called an MS-DOS® alias. An MS-DOS alias is an abbreviated form of the long filename. The file system creates the MS-DOS alias by taking the first six characters of the long filename (not counting spaces), followed by the tilde [~] and a numeric trailer. For example, the filename Brien's Document.txt would have an alias of BRIEN'~1.txt.

An interesting side effect results from the way VFAT stores its long filenames. When you create a long filename with VFAT, it uses one directory entry for the MS-DOS alias and another entry for every 13 characters of the long filename. In theory, a single long filename could occupy up to 21 directory entries. The root directory has a limit of 512 files, but if you were to use the maximum length long filenames in the root directory, you could cut this limit to a mere 24 files. Therefore, you should use long filenames very sparingly in the root directory. Other directories aren't affected by this limit.

You may be wondering why we're discussing VFAT. The reason is it's becoming more common than FAT, but aside from the differences I mentioned above, VFAT has the same limitations. When you tell Windows NT to format a partition as FAT, it actually formats the partition as VFAT. The only time you'll have a true FAT partition under Windows NT 4.0 is when you use another operating system, such as MS-DOS, to format the partition.

FAT32

FAT32 is actually an extension of FAT and VFAT, first introduced with Windows 95 OEM Service Release 2 (OSR2). FAT32 greatly enhances the VFAT file system but it does have its drawbacks.

The greatest advantage to FAT32 is that it dramatically increases the amount of free hard disk space. To illustrate this point, consider that a FAT partition (also known as a FAT16 partition) allows only a certain number of clusters per partition. Therefore, as your partition size increases, the cluster size must also increase. For example, a 512-MB FAT partition has a cluster size of 8K, while a 2-GB partition has a cluster size of 32K.

This may not sound like a big deal until you consider that the FAT file system only works in single cluster increments. For example, on a 2-GB partition, a 1-byte file will occupy the entire cluster, thereby consuming 32K, or roughly 32,000 times the amount of space that the file should consume. This rule applies to every file on your hard disk, so you can see how much space can be wasted.

Converting a partition to FAT32 reduces the cluster size (and overcomes the 2-GB partition size limit). For partitions 8 GB and smaller, the cluster size is reduced to a mere 4K. As you can imagine, it's not uncommon to gain back hundreds of megabytes by converting a partition to FAT32, especially if the partition contains a lot of small files.

Note: This section of the quote/ article (1999) is out of date. Updated info quote below.

As I mentioned, FAT32 does have limitations. Unfortunately, it isn't compatible with any operating system other than Windows 98 and the OSR2 version of Windows 95. However, Windows 2000 will be able to read FAT32 partitions.

The other disadvantage is that your disk utilities and antivirus software must be FAT32-aware. Otherwise, they could interpret the new file structure as an error and try to correct it, thus destroying data in the process.

Finally, I should mention that converting to FAT32 is a one-way process. Once you've converted to FAT32, you can't convert the partition back to FAT16. Therefore, before converting to FAT32, you need to consider whether the computer will ever be used in a dual-boot environment. I should also point out that although other operating systems such as Windows NT can't directly read a FAT32 partition, they can read it across the network. Therefore, it's no problem to share information stored on a FAT32 partition with other computers on a network that run older operating systems.

Updated mentioned in comment by Doktor-J (assimilated to update out of date answer in case comment is ever lost):

I'd just like to point out that most modern operating systems (WinXP/Vista/7/8, MacOS X, most if not all Linux variants) can read FAT32, contrary to what the second-to-last paragraph suggests.

The original article was written in 1999, and being posted on a Microsoft website, probably wasn't concerned with non-Microsoft operating systems anyways.

The operating systems "excluded" by that paragraph are probably the original Windows 95, Windows NT 4.0, Windows 3.1, DOS, etc.

jQuery: read text file from file system

This doesn't work and it shouldn't because it would be a giant security hole.

Have a look at the new File System API. It allows you to request access to a virtual, sandboxed filesystem governed by the browser. You will have to request your user to "upload" their file into the sandboxed filesystem once, but afterwards you can work with it very elegantly.

While this definitely is the future, it is still highly experimental and only works in Google Chrome as far as CanIUse knows.

Exploring Docker container's file system

The docker exec command to run a command in a running container can help in multiple cases.


Usage:  docker exec [OPTIONS] CONTAINER COMMAND [ARG...]

Run a command in a running container

Options:
  -d, --detach               Detached mode: run command in the background
      --detach-keys string   Override the key sequence for detaching a
                             container
  -e, --env list             Set environment variables
  -i, --interactive          Keep STDIN open even if not attached
      --privileged           Give extended privileges to the command
  -t, --tty                  Allocate a pseudo-TTY
  -u, --user string          Username or UID (format:
                             [:])
  -w, --workdir string       Working directory inside the container

For example :

1) Accessing in bash to the running container filesystem :

docker exec -it containerId bash 

2) Accessing in bash to the running container filesystem as root to be able to have required rights :

docker exec -it -u root containerId bash  

This is particularly useful to be able to do some processing as root in a container.

3) Accessing in bash to the running container filesystem with a specific working directory :

docker exec -it -w /var/lib containerId bash 

What is the best place for storing uploaded images, SQL database or disk file system?

It depends on your requirements, specially volume, users and frequency of search. But, for small or medium office, the best option is to use an application like Apple Photos or Adobe Lighroom. They are specialized to store, catalog, index, and organize this kind of resource. But, for large organizations, with strong requirements of storage and high number of users, it is recommend instantiate an Content Management plataform with a Digital Asset Management, like Nuxeo or Alfresco; both offers very good resources do manage very large volumes of data with simplified methods to retrive them. And, very important: there is an free (open source) option for both platforms.

Check if a string is a valid Windows directory (folder) path

I actually disagree with SLaks. That solution did not work for me. Exception did not happen as expected. But this code worked for me:

if(System.IO.Directory.Exists(path))
{
    ...
}

How can a file be copied?

Function Copies
metadata
Copies
permissions
Uses file object Destination
may be directory
shutil.copy No Yes No Yes
shutil.copyfile No No No No
shutil.copy2 Yes Yes No Yes
shutil.copyfileobj No No Yes No

Linux delete file with size 0

you would want to use find:

 find . -size 0 -delete

How do I check if a given string is a legal/valid file name under Windows?

Also CON, PRN, AUX, NUL, COM# and a few others are never legal filenames in any directory with any extension.

How do I programmatically change file permissions?

In addition to erickson's suggestions, there's also jna, which allows you to call native libraries without using jni. It's shockingly easy to use, and I've used it on a couple of projects with great success.

The only caveat is that it's slower than jni, so if you're doing this to a very large number of files that might be an issue for you.

(Editing to add example)

Here's a complete jna chmod example:

import com.sun.jna.Library;
import com.sun.jna.Native;

public class Main {
    private static CLibrary libc = (CLibrary) Native.loadLibrary("c", CLibrary.class);

    public static void main(String[] args) {
        libc.chmod("/path/to/file", 0755);
    }
}

interface CLibrary extends Library {
    public int chmod(String path, int mode);
}

What is Android's file system?

It depends on what filesystem, for example /system and /data are yaffs2 while /sdcard is vfat. This is the output of mount:

rootfs / rootfs ro 0 0
tmpfs /dev tmpfs rw,mode=755 0 0
devpts /dev/pts devpts rw,mode=600 0 0
proc /proc proc rw 0 0
sysfs /sys sysfs rw 0 0
tmpfs /sqlite_stmt_journals tmpfs rw,size=4096k 0 0
none /dev/cpuctl cgroup rw,cpu 0 0
/dev/block/mtdblock0 /system yaffs2 ro 0 0
/dev/block/mtdblock1 /data yaffs2 rw,nosuid,nodev 0 0
/dev/block/mtdblock2 /cache yaffs2 rw,nosuid,nodev 0 0
/dev/block//vold/179:0 /sdcard vfat rw,dirsync,nosuid,nodev,noexec,uid=1000,gid=1015,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0

and with respect to other filesystems supported, this is the list

nodev   sysfs
nodev   rootfs
nodev   bdev
nodev   proc
nodev   cgroup
nodev   binfmt_misc
nodev   sockfs
nodev   pipefs
nodev   anon_inodefs
nodev   tmpfs
nodev   inotifyfs
nodev   devpts
nodev   ramfs
         vfat
         msdos
nodev   nfsd
nodev   smbfs
         yaffs
         yaffs2
nodev   rpc_pipefs

Remove directory which is not empty

A quick and dirty way (maybe for testing) could be to directly use the exec or spawn method to invoke OS call to remove the directory. Read more on NodeJs child_process.

let exec = require('child_process').exec
exec('rm -Rf /tmp/*.zip', callback)

Downsides are:

  1. You are depending on underlying OS i.e. the same method would run in unix/linux but probably not in windows.
  2. You cannot hijack the process on conditions or errors. You just give the task to underlying OS and wait for the exit code to be returned.

Benefits:

  1. These processes can run asynchronously.
  2. You can listen for the output/error of the command, hence command output is not lost. If operation is not completed, you can check the error code and retry.

What tool to use to draw file tree diagram

Why could you not just make a file structure on the Windows file system and populate it with your desired names, then use a screen grabber like HyperSnap (or the ubiquitous Alt-PrtScr) to capture a section of the Explorer window.

I did this when 'demoing' an internet application which would have collapsible sections, I just had to create files that looked like my desired entries.

HyperSnap gives JPGs at least (probably others but I've never bothered to investigate).

Or you could screen capture the icons +/- from Explorer and use them within MS Word Draw itself to do your picture, but I've never been able to get MS Word Draw to behave itself properly.

How many files can I put in a directory?

If the time involved in implementing a directory partitioning scheme is minimal, I am in favor of it. The first time you have to debug a problem that involves manipulating a 10000-file directory via the console you will understand.

As an example, F-Spot stores photo files as YYYY\MM\DD\filename.ext, which means the largest directory I have had to deal with while manually manipulating my ~20000-photo collection is about 800 files. This also makes the files more easily browsable from a third party application. Never assume that your software is the only thing that will be accessing your software's files.

Why can't I do <img src="C:/localfile.jpg">?

Newtang's observation about the security rules aside, how are you going to know that anyone who views your page will have the correct images at c:\localfile.jpg? You can't. Even if you think you can, you can't. It presupposes a windows environment, for one thing.

Delete directories recursively in Java

If you have Spring, you can use FileSystemUtils.deleteRecursively:

import org.springframework.util.FileSystemUtils;

boolean success = FileSystemUtils.deleteRecursively(new File("directory"));

Path.Combine absolute with relative path strings

What Works:

string relativePath = "..\\bling.txt";
string baseDirectory = "C:\\blah\\";
string absolutePath = Path.GetFullPath(baseDirectory + relativePath);

(result: absolutePath="C:\bling.txt")

What doesn't work

string relativePath = "..\\bling.txt";
Uri baseAbsoluteUri = new Uri("C:\\blah\\");
string absolutePath = new Uri(baseAbsoluteUri, relativePath).AbsolutePath;

(result: absolutePath="C:/blah/bling.txt")

How do you determine the ideal buffer size when using FileInputStream?

Reading files using Java NIO's FileChannel and MappedByteBuffer will most likely result in a solution that will be much faster than any solution involving FileInputStream. Basically, memory-map large files, and use direct buffers for small ones.

How to create a directory using Ansible

Easiest way to make a directory in Ansible.

  • name: Create your_directory if it doesn't exist. file: path: /etc/your_directory

OR

You want to give sudo privileges to that directory.

  • name: Create your_directory if it doesn't exist. file: path: /etc/your_directory mode: '777'

GIT_DISCOVERY_ACROSS_FILESYSTEM not set

In short, git is trying to access a repo it considers on another filesystem and to tell it explicitly that you're okay with this, you must set the environment variable GIT_DISCOVERY_ACROSS_FILESYSTEM=1

I'm working in a CI/CD environment and using a dockerized git so I have to set it in that environment docker run -e GIT_DISCOVERY_ACROSS_FILESYSTEM=1 -v $(pwd):/git --rm alpine/git rev-parse --short HEAD\'

If you're curious: Above mounts $(pwd) into the git docker container and passes "rev-parse --short HEAD" to the git command in the container, which it then runs against that mounted volums.

How can I search sub-folders using glob.glob module?

(The first options are of course mentioned in other answers, here the goal is to show that glob uses os.scandir internally, and provide a direct answer with this).


Using glob

As explained before, with Python 3.5+, it's easy:

import glob
for f in glob.glob('d:/temp/**/*', recursive=True):
    print(f)

#d:\temp\New folder
#d:\temp\New Text Document - Copy.txt
#d:\temp\New folder\New Text Document - Copy.txt
#d:\temp\New folder\New Text Document.txt

Using pathlib

from pathlib import Path
for f in Path('d:/temp').glob('**/*'):
    print(f)

Using os.scandir

os.scandir is what glob does internally. So here is how to do it directly, with a use of yield:

def listpath(path):
    for f in os.scandir(path):
        f2 = os.path.join(path, f)
        if os.path.isdir(f):
            yield f2
            yield from listpath(f2)
        else:
            yield f2

for f in listpath('d:\\temp'):
    print(f)

Get a filtered list of files in a directory

import os

dir="/path/to/dir"
[x[0]+"/"+f for x in os.walk(dir) for f in x[2] if f.endswith(".jpg")]

This will give you a list of jpg files with their full path. You can replace x[0]+"/"+f with f for just filenames. You can also replace f.endswith(".jpg") with whatever string condition you wish.

How to uninstall a windows service and delete its files without rebooting

If in .net ( I'm not sure if it works for all windows services)

  • Stop the service (THis may be why you're having a problem.)
  • InstallUtil -u [name of executable]
  • Installutil -i [name of executable]
  • Start the service again...

Unless I'm changing the service's public interface, I often deploy upgraded versions of my services without even unistalling/reinstalling... ALl I do is stop the service, replace the files and restart the service again...

What's the best way to check if a file exists in C?

FILE *file;
    if((file = fopen("sample.txt","r"))!=NULL)
        {
            // file exists
            fclose(file);
        }
    else
        {
            //File not found, no memory leak since 'file' == NULL
            //fclose(file) would cause an error
        }

How to use glob() to find files recursively?

based on other answers this is my current working implementation, which retrieves nested xml files in a root directory:

files = []
for root, dirnames, filenames in os.walk(myDir):
    files.extend(glob.glob(root + "/*.xml"))

I'm really having fun with python :)

No space left on device

Maybe you are out of inodes. Try df -i

                     2591792  136322 2455470    6% /home
/dev/sdb1            1887488 1887488       0  100% /data

Disk used 6% but inode table full.

open_basedir restriction in effect. File(/) is not within the allowed path(s):

If you're running this with php file.php. You need to edit php.ini Find this file:

: locate php.ini
/etc/php/php.ini

And append file's path to open_basedir property:

open_basedir = /srv/http/:/home/:/tmp/:/usr/share/pear/:/usr/share/webapps/:/etc/webapps/:/run/media/andrew/ext4/protected

How to determine MIME type of file in android?

I faced similar problem. So far I know result may different for different names, so finally came to this solution.

public String getMimeType(String filePath) {
    String type = null;
    String extension = null;
    int i = filePath.lastIndexOf('.');
    if (i > 0)
        extension = filePath.substring(i+1);
    if (extension != null)
        type = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
    return type;
}  

How to set TLS version on apache HttpClient

Using -Dhttps.protocols=TLSv1.2 JVM argument didn't work for me. What worked is the following code

RequestConfig.Builder requestBuilder = RequestConfig.custom();
//other configuration, for example
requestBuilder = requestBuilder.setConnectTimeout(1000);

SSLContext sslContext = SSLContextBuilder.create().useProtocol("TLSv1.2").build();

HttpClientBuilder builder = HttpClientBuilder.create();
builder.setDefaultRequestConfig(requestBuilder.build());
builder.setProxy(new HttpHost("your.proxy.com", 3333)); //if you have proxy
builder.setSSLContext(sslContext);

HttpClient client = builder.build();

Use the following JVM argument to verify

-Djavax.net.debug=all

How to index an element of a list object in R

Indexing a list is done using double bracket, i.e. hypo_list[[1]] (e.g. have a look here: http://www.r-tutor.com/r-introduction/list). BTW: read.table does not return a table but a dataframe (see value section in ?read.table). So you will have a list of dataframes, rather than a list of table objects. The principal mechanism is identical for tables and dataframes though.

Note: In R, the index for the first entry is a 1 (not 0 like in some other languages).

Dataframes

l <- list(anscombe, iris)   # put dfs in list
l[[1]]             # returns anscombe dataframe

anscombe[1:2, 2]   # access first two rows and second column of dataset
[1] 10  8

l[[1]][1:2, 2]     # the same but selecting the dataframe from the list first
[1] 10  8

Table objects

tbl1 <- table(sample(1:5, 50, rep=T))
tbl2 <- table(sample(1:5, 50, rep=T))
l <- list(tbl1, tbl2)  # put tables in a list

tbl1[1:2]              # access first two elements of table 1 

Now with the list

l[[1]]                 # access first table from the list

1  2  3  4  5 
9 11 12  9  9 

l[[1]][1:2]            # access first two elements in first table

1  2 
9 11 

Correct way to create rounded corners in Twitter Bootstrap

I guess it is what you are looking for: http://blogsh.de/tag/bootstrap-less/

@import 'bootstrap.less';
div.my-class {
    .border-radius( 5px );
}

You can use it because there is a mixin:

.border-radius(@radius: 5px) {
  -webkit-border-radius: @radius;
     -moz-border-radius: @radius;
          border-radius: @radius;
}

For Bootstrap 3, there are 4 mixins you can use...

.border-top-radius(@radius);
.border-right-radius(@radius);
.border-bottom-radius(@radius);
.border-left-radius(@radius);

or you can make your own mixin using the top 4 to do it in one shot.

.border-radius(@radius){
    .border-top-radius(@radius);
    .border-right-radius(@radius);
    .border-bottom-radius(@radius);
    .border-left-radius(@radius);
}

How to get only the last part of a path in Python?

path = "/folderA/folderB/folderC/folderD/"
last = path.split('/').pop()

VBA Subscript out of range - error 9

Suggest the following simplification: capture return value from Workbooks.Add instead of subscripting Windows() afterward, as follows:

Set wkb = Workbooks.Add
wkb.SaveAs ...

wkb.Activate ' instead of Windows(expression).Activate


General Philosophy Advice:

Avoid use Excel's built-ins: ActiveWorkbook, ActiveSheet, and Selection: capture return values, and, favor qualified expressions instead.

Use the built-ins only once and only in outermost macros(subs) and capture at macro start, e.g.

Set wkb = ActiveWorkbook
Set wks = ActiveSheet
Set sel = Selection

During and within macros do not rely on these built-in names, instead capture return values, e.g.

Set wkb = Workbooks.Add 'instead of Workbooks.Add without return value capture
wkb.Activate 'instead of Activeworkbook.Activate

Also, try to use qualified expressions, e.g.

wkb.Sheets("Sheet3").Name = "foo" ' instead of Sheets("Sheet3").Name = "foo"

or

Set newWks = wkb.Sheets.Add
newWks.Name = "bar" 'instead of ActiveSheet.Name = "bar"

Use qualified expressions, e.g.

newWks.Name = "bar" 'instead of `xyz.Select` followed by Selection.Name = "bar" 

These methods will work better in general, give less confusing results, will be more robust when refactoring (e.g. moving lines of code around within and between methods) and, will work better across versions of Excel. Selection, for example, changes differently during macro execution from one version of Excel to another.

Also please note that you'll likely find that you don't need to .Activate nearly as much when using more qualified expressions. (This can mean the for the user the screen will flicker less.) Thus the whole line Windows(expression).Activate could simply be eliminated instead of even being replaced by wkb.Activate.

(Also note: I think the .Select statements you show are not contributing and can be omitted.)

(I think that Excel's macro recorder is responsible for promoting this more fragile style of programming using ActiveSheet, ActiveWorkbook, Selection, and Select so much; this style leaves a lot of room for improvement.)

String contains - ignore case

If you won't go with regex:

"ABCDEFGHIJKLMNOP".toLowerCase().contains("gHi".toLowerCase())

Check if int is between two numbers

You are human, and therefore you understand what the term "10 < x < 20" suppose to mean. The computer doesn't have this intuition, so it reads it as: "(10 < x) < 20".

For example, if x = 15, it will calculate:

(10 < x) => TRUE

"TRUE < 20" => ???

In C programming, it will be worse, since there are no True\False values. If x = 5, the calculation will be:

10 < x => 0 (the value of False)

0 < 20 => non-0 number (True)

and therefore "10 < 5 < 20" will return True! :S

how to create a window with two buttons that will open a new window

You add your ActionListener twice to button. So correct your code for button2 to

  JButton button2 = new JButton("hello agin2");
  panel.add(button2);
  button2.addActionListener (new Action2());//note the button2 here instead of button

Furthermore, perform your Swing operations on the correct thread by using EventQueue.invokeLater

What is meant with "const" at end of function declaration?

A "const function", denoted with the keyword const after a function declaration, makes it a compiler error for this class function to change a member variable of the class. However, reading of a class variables is okay inside of the function, but writing inside of this function will generate a compiler error.

Another way of thinking about such "const function" is by viewing a class function as a normal function taking an implicit this pointer. So a method int Foo::Bar(int random_arg) (without the const at the end) results in a function like int Foo_Bar(Foo* this, int random_arg), and a call such as Foo f; f.Bar(4) will internally correspond to something like Foo f; Foo_Bar(&f, 4). Now adding the const at the end (int Foo::Bar(int random_arg) const) can then be understood as a declaration with a const this pointer: int Foo_Bar(const Foo* this, int random_arg). Since the type of this in such case is const, no modifications of member variables are possible.

It is possible to loosen the "const function" restriction of not allowing the function to write to any variable of a class. To allow some of the variables to be writable even when the function is marked as a "const function", these class variables are marked with the keyword mutable. Thus, if a class variable is marked as mutable, and a "const function" writes to this variable then the code will compile cleanly and the variable is possible to change. (C++11)

As usual when dealing with the const keyword, changing the location of the const key word in a C++ statement has entirely different meanings. The above usage of const only applies when adding const to the end of the function declaration after the parenthesis.

const is a highly overused qualifier in C++: the syntax and ordering is often not straightforward in combination with pointers. Some readings about const correctness and the const keyword:

Const correctness

The C++ 'const' Declaration: Why & How

Facebook api: (#4) Application request limit reached

The Facebook API limit isn't really documented, but apparently it's something like: 600 calls per 600 seconds, per token & per IP. As the site is restricted, quoting the relevant part:

After some testing and discussion with the Facebook platform team, there is no official limit I'm aware of or can find in the documentation. However, I've found 600 calls per 600 seconds, per token & per IP to be about where they stop you. I've also seen some application based rate limiting but don't have any numbers.

As a general rule, one call per second should not get rate limited. On the surface this seems very restrictive but remember you can batch certain calls and use the subscription API to get changes.

As you can access the Graph API on the client side via the Javascript SDK; I think if you travel your request for photos from the client, you won't hit any application limit as it's the user (each one with unique id) who's fetching data, not your application server (unique ID).

This may mean a huge refactor if everything you do go through a server. But it seems like the best solution if you have so many request (as it'll give a breath to your server).

Else, you can try batch request, but I guess you're already going this way if you have big traffic.


If nothing of this works, according to the Facebook Platform Policy you should contact them.

If you exceed, or plan to exceed, any of the following thresholds please contact us as you may be subject to additional terms: (>5M MAU) or (>100M API calls per day) or (>50M impressions per day).

How to add a custom CA Root certificate to the CA Store used by pip in Windows?

I think nt86's solution is the most appropriate because it leverages the underlying Windows infrastructure (certificate store). But it doesn't explain how to install python-certifi-win32 to start with since pip is non functional.

The trick is to use --trustedhost to install python-certifi-win32 and then after that, pip will automatically use the windows certificate store to load the certificate used by the proxy.

So in a nutshell, you should do:

pip install python-certifi-win32 -trustedhost pypi.org

and after that you should be good to go

Save Javascript objects in sessionStorage

Could you not 'stringify' your object...then use sessionStorage.setItem() to store that string representation of your object...then when you need it sessionStorage.getItem() and then use $.parseJSON() to get it back out?

Working example http://jsfiddle.net/pKXMa/

Combining paste() and expression() functions in plot labels

If x^2 and y^2 were expressions already given in the variable squared, this solves the problem:

labNames <- c('xLab','yLab')
squared <- c(expression('x'^2), expression('y'^2))

xlab <- eval(bquote(expression(.(labNames[1]) ~ .(squared[1][[1]]))))
ylab <- eval(bquote(expression(.(labNames[2]) ~ .(squared[2][[1]]))))

plot(c(1:10), xlab = xlab, ylab = ylab)

Please note the [[1]] behind squared[1]. It gives you the content of "expression(...)" between the brackets without any escape characters.

PHP: merge two arrays while keeping keys instead of reindexing?

Two arrays can be easily added or union without chaning their original indexing by + operator. This will be very help full in laravel and codeigniter select dropdown.

 $empty_option = array(
         ''=>'Select Option'
          );

 $option_list = array(
          1=>'Red',
          2=>'White',
          3=>'Green',
         );

  $arr_option = $empty_option + $option_list;

Output will be :

$arr_option = array(
   ''=>'Select Option'
   1=>'Red',
   2=>'White',
   3=>'Green',
 );

Matching a Forward Slash with a regex

If you want to use / you need to escape it with a \

var word = /\/(\w+)/ig;

How to set a background image in Xcode using swift?

Background Image from API in swift 4 (with Kingfisher) :

import UIKit
import Kingfisher

extension UIView {

func addBackgroundImage(imgUrl: String, placeHolder: String){
    let backgroundImage = UIImageView(frame: self.bounds)
    backgroundImage.kf.setImage(with: URL(string: imgUrl), placeholder: UIImage(named: placeHolder))
    backgroundImage.contentMode = UIViewContentMode.scaleAspectFill
    self.insertSubview(backgroundImage, at: 0)

}
}

Usage:

someview.addBackgroundImage(imgUrl: "yourImgUrl", placeHolder: "placeHolderName")

Why does overflow:hidden not work in a <td>?

I'm not familiar with the specific issue, but you could stick a div, etc inside the td and set overflow on that.

Not Able To Debug App In Android Studio

Here's a little oops that may catch some: It's pretty easy to accidentally have a filter typed in for the logcat output window (the text box with the magnifying glass) and forget about it. That which will potentially filter out all output and make it look like nothing is there.

Android: Difference between onInterceptTouchEvent and dispatchTouchEvent?

Small answer:

onInterceptTouchEvent comes before setOnTouchListener.

Using NSPredicate to filter an NSArray based on NSDictionary keys

#import <Foundation/Foundation.h>
// clang -framework Foundation Siegfried.m 
    int
main() {
    NSArray *arr = @[
        @{@"1" : @"Fafner"},
        @{@"1" : @"Fasolt"}
    ];
    NSPredicate *p = [NSPredicate predicateWithFormat:
        @"SELF['1'] CONTAINS 'e'"];
    NSArray *res = [arr filteredArrayUsingPredicate:p];
    NSLog(@"Siegfried %@", res);
    return 0;
}

How is OAuth 2 different from OAuth 1?

OAuth 2.0 promises to simplify things in following ways:

  1. SSL is required for all the communications required to generate the token. This is a huge decrease in complexity because those complex signatures are no longer required.
  2. Signatures are not required for the actual API calls once the token has been generated -- SSL is also strongly recommended here.
  3. Once the token was generated, OAuth 1.0 required that the client send two security tokens on every API call, and use both to generate the signature. OAuth 2.0 has only one security token, and no signature is required.
  4. It is clearly specified which parts of the protocol are implemented by the "resource owner," which is the actual server that implements the API, and which parts may be implemented by a separate "authorization server." That will make it easier for products like Apigee to offer OAuth 2.0 support to existing APIs.

Source:http://blog.apigee.com/detail/oauth_differences

IBOutlet and IBAction

Interface Builder uses them to determine what members and messages can be 'wired' up to the interface controls you are using in your window/view.

IBOutlet and IBAction are purely there as markers that Interface Builder looks for when it parses your code at design time, they don't have any affect on the code generated by the compiler.

Getting RAW Soap Data from a Web Reference Client running in ASP.net

It looks like Tim Carter's solution doesn't work if the call to the web reference throws an exception. I've been trying to get at the raw web resonse so I can examine it (in code) in the error handler once the exception is thrown. However, I'm finding that the response log written by Tim's method is blank when the call throws an exception. I don't completely understand the code, but it appears that Tim's method cuts into the process after the point where .Net has already invalidated and discarded the web response.

I'm working with a client that's developing a web service manually with low level coding. At this point, they are adding their own internal process error messages as HTML formatted messages into the response BEFORE the SOAP formatted response. Of course, the automagic .Net web reference blows up on this. If I could get at the raw HTTP response after an exception is thrown, I could look for and parse any SOAP response within the mixed returning HTTP response and know that they received my data OK or not.

Later ...

Here's a solution that does work, even after an execption (note that I'm only after the response - could get the request too):

namespace ChuckBevitt
{
    class GetRawResponseSoapExtension : SoapExtension
    {
        //must override these three methods
        public override object GetInitializer(LogicalMethodInfo methodInfo, SoapExtensionAttribute attribute)
        {
            return null;
        }
        public override object GetInitializer(Type serviceType)
        {
            return null;
        }
        public override void Initialize(object initializer)
        {
        }

        private bool IsResponse = false;

        public override void ProcessMessage(SoapMessage message)
        {
            //Note that ProcessMessage gets called AFTER ChainStream.
            //That's why I'm looking for AfterSerialize, rather than BeforeDeserialize
            if (message.Stage == SoapMessageStage.AfterSerialize)
                IsResponse = true;
            else
                IsResponse = false;
        }

        public override Stream ChainStream(Stream stream)
        {
            if (IsResponse)
            {
                StreamReader sr = new StreamReader(stream);
                string response = sr.ReadToEnd();
                sr.Close();
                sr.Dispose();

                File.WriteAllText(@"C:\test.txt", response);

                byte[] ResponseBytes = Encoding.ASCII.GetBytes(response);
                MemoryStream ms = new MemoryStream(ResponseBytes);
                return ms;

            }
            else
                return stream;
        }
    }
}

Here's how you configure it in the config file:

<configuration>
     ...
  <system.web>
    <webServices>
      <soapExtensionTypes>
        <add type="ChuckBevitt.GetRawResponseSoapExtension, TestCallWebService"
           priority="1" group="0" />
      </soapExtensionTypes>
    </webServices>
  </system.web>
</configuration>

"TestCallWebService" shoud be replaced with the name of the library (that happened to be the name of the test console app I was working in).

You really shouldn't have to go to ChainStream; you should be able to do it more simply from ProcessMessage as:

public override void ProcessMessage(SoapMessage message)
{
    if (message.Stage == SoapMessageStage.BeforeDeserialize)
    {
        StreamReader sr = new StreamReader(message.Stream);
        File.WriteAllText(@"C:\test.txt", sr.ReadToEnd());
        message.Stream.Position = 0; //Will blow up 'cause type of stream ("ConnectStream") doesn't alow seek so can't reset position
    }
}

If you look up SoapMessage.Stream, it's supposed to be a read-only stream that you can use to inspect the data at this point. This is a screw-up 'cause if you do read the stream, subsequent processing bombs with no data found errors (stream was at end) and you can't reset the position to the beginning.

Interestingly, if you do both methods, the ChainStream and the ProcessMessage ways, the ProcessMessage method will work because you changed the stream type from ConnectStream to MemoryStream in ChainStream, and MemoryStream does allow seek operations. (I tried casting the ConnectStream to MemoryStream - wasn't allow.)

So ..... Microsoft should either allow seek operations on the ChainStream type or make the SoapMessage.Stream truly a read-only copy as it's supposed to be. (Write your congressman, etc...)

One further point. After creating a way to retreive the raw HTTP response after an exception, I still didn't get the full response (as determined by a HTTP sniffer). This was because when the development web service added the HTML error messages to the beginning of the response, it didn't adjust the Content-Length header, so the Content-Length value was less than the size of the actual response body. All I got was the Content-Length value number of characters - the rest were missing. Obviously, when .Net reads the response stream, it just reads the Content-Length number of characters and doesn't allow for the Content-Length value possibily being wrong. This is as it should be; but if the Content-Length header value is wrong, the only way you'll ever get the entire response body is with a HTTP sniffer (I user HTTP Analyzer from http://www.ieinspector.com).

Read all files in a folder and apply a function to each data frame

Here is a tidyverse option that might not the most elegant, but offers some flexibility in terms of what is included in the summary:

library(tidyverse)
dir_path <- '~/path/to/data/directory/'
file_pattern <- 'Df\\.[0-9]\\.csv' # regex pattern to match the file name format

read_dir <- function(dir_path, file_name){
  read_csv(paste0(dir_path, file_name)) %>% 
    mutate(file_name = file_name) %>%                # add the file name as a column              
    gather(variable, value, A:B) %>%                 # convert the data from wide to long
    group_by(file_name, variable) %>% 
    summarize(sum = sum(value, na.rm = TRUE),
              min = min(value, na.rm = TRUE),
              mean = mean(value, na.rm = TRUE),
              median = median(value, na.rm = TRUE),
              max = max(value, na.rm = TRUE))
  }

df_summary <- 
  list.files(dir_path, pattern = file_pattern) %>% 
  map_df(~ read_dir(dir_path, .))

df_summary
# A tibble: 8 x 7
# Groups:   file_name [?]
  file_name variable   sum   min  mean median   max
  <chr>     <chr>    <int> <dbl> <dbl>  <dbl> <dbl>
1 Df.1.csv  A           34     4  5.67    5.5     8
2 Df.1.csv  B           22     1  3.67    3       9
3 Df.2.csv  A           21     1  3.5     3.5     6
4 Df.2.csv  B           16     1  2.67    2.5     5
5 Df.3.csv  A           30     0  5       5      11
6 Df.3.csv  B           43     1  7.17    6.5    15
7 Df.4.csv  A           21     0  3.5     3       8
8 Df.4.csv  B           42     1  7       6      16

Verify a method call using Moq

You're checking the wrong method. Moq requires that you Setup (and then optionally Verify) the method in the dependency class.

You should be doing something more like this:

class MyClassTest
{
    [TestMethod]
    public void MyMethodTest()
    {
        string action = "test";
        Mock<SomeClass> mockSomeClass = new Mock<SomeClass>();

        mockSomeClass.Setup(mock => mock.DoSomething());

        MyClass myClass = new MyClass(mockSomeClass.Object);
        myClass.MyMethod(action);

        // Explicitly verify each expectation...
        mockSomeClass.Verify(mock => mock.DoSomething(), Times.Once());

        // ...or verify everything.
        // mockSomeClass.VerifyAll();
    }
}

In other words, you are verifying that calling MyClass#MyMethod, your class will definitely call SomeClass#DoSomething once in that process. Note that you don't need the Times argument; I was just demonstrating its value.

Get latitude and longitude automatically using php, API

I think allow_url_fopen on your apache server is disabled. you need to trun it on.

kindly change allow_url_fopen = 0 to allow_url_fopen = 1

Don't forget to restart your Apache server after changing it.

How to solve SQL Server Error 1222 i.e Unlock a SQL Server table

In the SQL Server Management Studio, to find out details of the active transaction, execute following command

DBCC opentran()

You will get the detail of the active transaction, then from the SPID of the active transaction, get the detail about the SPID using following commands

exec sp_who2 <SPID>
exec sp_lock <SPID>

For example, if SPID is 69 then execute the command as

exec sp_who2 69
exec sp_lock 69

Now , you can kill that process using the following command

KILL 69

I hope this helps :)

How to convert numbers to words without using num2word library?

if Number > 19 and Number < 99:
    textNumber = str(Number)
    firstDigit, secondDigit = textNumber
    firstWord = num2words2[int(firstDigit)]
    secondWord = num2words1[int(secondDigit)]
    word = firstWord + secondWord 
if Number <20 and Number > 0:
    word = num2words1[Number]
if Number > 99:
    error

Is there a portable way to get the current username in Python?

Combined pwd and getpass approach, based on other answers:

try:
  import pwd
except ImportError:
  import getpass
  pwd = None

def current_user():
  if pwd:
    return pwd.getpwuid(os.geteuid()).pw_name
  else:
    return getpass.getuser()

Jquery click not working with ipad

Thanks to the previous commenters I found all the following worked for me:

Either adding an onclick stub to the element

onclick="void(0);" 

or user a cursor pointer style

style="cursor:pointer;"

or as in my existing code my jquery code needed tap added

$(document).on('click tap','.ciAddLike',function(event)
{
    alert('like added!'); // stopped working in ios safari until tap added
});

I am adding a cross-reference back to the Apple Docs for those interested. See Apple Docs:Making Events Clickable

(I'm not sure exactly when my hybrid app stopped processing clicks but I seem to remember they worked iOS 7 and earlier.)

Difference between PACKETS and FRAMES

A packet is a general term for a formatted unit of data carried by a network. It is not necessarily connected to a specific OSI model layer.

For example, in the Ethernet protocol on the physical layer (layer 1), the unit of data is called an "Ethernet packet", which has an Ethernet frame (layer 2) as its payload. But the unit of data of the Network layer (layer 3) is also called a "packet".

A frame is also a unit of data transmission. In computer networking the term is only used in the context of the Data link layer (layer 2).

Another semantical difference between packet and frame is that a frame envelops your payload with a header and a trailer, just like a painting in a frame, while a packet usually only has a header.

But in the end they mean roughly the same thing and the distinction is used to avoid confusion and repetition when talking about the different layers.

Can I try/catch a warning?

I would only recommend using @ to suppress warnings when it's a straight forward operation (e.g. $prop = @($high/($width - $depth)); to skip division by zero warnings). However in most cases it's better to handle.

How to set corner radius of imageView?

You can define border radius of any view providing an "User defined Runtime Attributes", providing key path "layer.cornerRadius" of type string and then the value of radius you need ;) See attached images below:

Configuring in XCode

Result in emulator

MySQL JOIN with LIMIT 1 on joined table

Replace the tables with yours:

SELECT * FROM works w 
LEFT JOIN 
(SELECT photoPath, photoUrl, videoUrl FROM workmedias LIMIT 1) AS wm ON wm.idWork = w.idWork

Fill DataTable from SQL Server database

Try with following:

public DataTable fillDataTable(string table)
    {
        string query = "SELECT * FROM dstut.dbo." +table;

        SqlConnection sqlConn = new SqlConnection(conSTR);
        sqlConn.Open();
        SqlCommand cmd = new SqlCommand(query, sqlConn);
        SqlDataAdapter da=new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        da.Fill(dt);
        sqlConn.Close();
        return dt;
    }

Hope it is helpful.

How to make the corners of a button round?

You can also use the card layout like below

  <androidx.cardview.widget.CardView
        android:layout_width="match_parent"
        android:layout_height="60dp"
        app:cardCornerRadius="30dp">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"

            >

            <TextView
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:gravity="center"
                android:text="Template"

                />

        </LinearLayout>

    </androidx.cardview.widget.CardView>

OpenCV & Python - Image too big to display

Although I was expecting an automatic solution (fitting to the screen automatically), resizing solves the problem as well.

import cv2
cv2.namedWindow("output", cv2.WINDOW_NORMAL)        # Create window with freedom of dimensions
im = cv2.imread("earth.jpg")                        # Read image
imS = cv2.resize(im, (960, 540))                    # Resize image
cv2.imshow("output", imS)                            # Show image
cv2.waitKey(0)                                      # Display the image infinitely until any keypress

How to use parameters with HttpPost

You can also use this approach in case you want to pass some http parameters and send a json request:

(note: I have added in some extra code just incase it helps any other future readers)

public void postJsonWithHttpParams() throws URISyntaxException, UnsupportedEncodingException, IOException {

    //add the http parameters you wish to pass
    List<NameValuePair> postParameters = new ArrayList<>();
    postParameters.add(new BasicNameValuePair("param1", "param1_value"));
    postParameters.add(new BasicNameValuePair("param2", "param2_value"));

    //Build the server URI together with the parameters you wish to pass
    URIBuilder uriBuilder = new URIBuilder("http://google.ug");
    uriBuilder.addParameters(postParameters);

    HttpPost postRequest = new HttpPost(uriBuilder.build());
    postRequest.setHeader("Content-Type", "application/json");

    //this is your JSON string you are sending as a request
    String yourJsonString = "{\"str1\":\"a value\",\"str2\":\"another value\"} ";

    //pass the json string request in the entity
    HttpEntity entity = new ByteArrayEntity(yourJsonString.getBytes("UTF-8"));
    postRequest.setEntity(entity);

    //create a socketfactory in order to use an http connection manager
    PlainConnectionSocketFactory plainSocketFactory = PlainConnectionSocketFactory.getSocketFactory();
    Registry<ConnectionSocketFactory> connSocketFactoryRegistry = RegistryBuilder.<ConnectionSocketFactory>create()
            .register("http", plainSocketFactory)
            .build();

    PoolingHttpClientConnectionManager connManager = new PoolingHttpClientConnectionManager(connSocketFactoryRegistry);

    connManager.setMaxTotal(20);
    connManager.setDefaultMaxPerRoute(20);

    RequestConfig defaultRequestConfig = RequestConfig.custom()
            .setSocketTimeout(HttpClientPool.connTimeout)
            .setConnectTimeout(HttpClientPool.connTimeout)
            .setConnectionRequestTimeout(HttpClientPool.readTimeout)
            .build();

    // Build the http client.
    CloseableHttpClient httpclient = HttpClients.custom()
            .setConnectionManager(connManager)
            .setDefaultRequestConfig(defaultRequestConfig)
            .build();

    CloseableHttpResponse response = httpclient.execute(postRequest);

    //Read the response
    String responseString = "";

    int statusCode = response.getStatusLine().getStatusCode();
    String message = response.getStatusLine().getReasonPhrase();

    HttpEntity responseHttpEntity = response.getEntity();

    InputStream content = responseHttpEntity.getContent();

    BufferedReader buffer = new BufferedReader(new InputStreamReader(content));
    String line;

    while ((line = buffer.readLine()) != null) {
        responseString += line;
    }

    //release all resources held by the responseHttpEntity
    EntityUtils.consume(responseHttpEntity);

    //close the stream
    response.close();

    // Close the connection manager.
    connManager.close();
}

Is it possible to implement a Python for range loop without an iterator variable?

The general idiom for assigning to a value that isn't used is to name it _.

for _ in range(times):
    do_stuff()

Query to list all users of a certain group

If the DC is Win2k3 SP2 or above, you can use something like:

(&(objectCategory=user)(memberOf:1.2.840.113556.1.4.1941:=CN=GroupOne,OU=Security Groups,OU=Groups,DC=example,DC=com))

to get the nested group membership.

Source: https://ldapwiki.com/wiki/Active%20Directory%20Group%20Related%20Searches

Using sudo with Python script

I used this for python 3.5. I did it using subprocess module.Using the password like this is very insecure.

The subprocess module takes command as a list of strings so either create a list beforehand using split() or pass the whole list later. Read the documentation for moreinformation.

#!/usr/bin/env python
import subprocess

sudoPassword = 'mypass'
command = 'mount -t vboxsf myfolder /home/myuser/myfolder'.split()

cmd1 = subprocess.Popen(['echo',sudoPassword], stdout=subprocess.PIPE)
cmd2 = subprocess.Popen(['sudo','-S'] + command, stdin=cmd1.stdout, stdout=subprocess.PIPE)

output = cmd2.stdout.read.decode()

PHP error: "The zip extension and unzip command are both missing, skipping."

Actually composer nowadays seems to work without the zip command line command, so installing php-zip should be enough --- BUT it would display a warning:

As there is no 'unzip' command installed zip files are being unpacked using the PHP zip extension. This may cause invalid reports of corrupted archives. Installing 'unzip' may remediate them.

See also Is there a problem with using php-zip (composer warns about it)

subtract two times in python

instead of using time try timedelta:

from datetime import timedelta

t1 = timedelta(hours=7, minutes=36)
t2 = timedelta(hours=11, minutes=32)
t3 = timedelta(hours=13, minutes=7)
t4 = timedelta(hours=21, minutes=0)

arrival = t2 - t1
lunch = (t3 - t2 - timedelta(hours=1))
departure = t4 - t3

print(arrival, lunch, departure)

XML Parsing - Read a Simple XML File and Retrieve Values

Easy way to parse the xml is to use the LINQ to XML

for example you have the following xml file

<library>
    <track id="1" genre="Rap" time="3:24">
        <name>Who We Be RMX (feat. 2Pac)</name>
        <artist>DMX</artist>
        <album>The Dogz Mixtape: Who's Next?!</album>
    </track>
    <track id="2" genre="Rap" time="5:06">
        <name>Angel (ft. Regina Bell)</name>
        <artist>DMX</artist>
        <album>...And Then There Was X</album>
    </track>
    <track id="3" genre="Break Beat" time="6:16">
        <name>Dreaming Your Dreams</name>
        <artist>Hybrid</artist>
        <album>Wide Angle</album>
    </track>
    <track id="4" genre="Break Beat" time="9:38">
        <name>Finished Symphony</name>
        <artist>Hybrid</artist>
        <album>Wide Angle</album>
    </track>
<library>

For reading this file, you can use the following code:

public void Read(string  fileName)
{
    XDocument doc = XDocument.Load(fileName);

    foreach (XElement el in doc.Root.Elements())
    {
        Console.WriteLine("{0} {1}", el.Name, el.Attribute("id").Value);
        Console.WriteLine("  Attributes:");
        foreach (XAttribute attr in el.Attributes())
            Console.WriteLine("    {0}", attr);
        Console.WriteLine("  Elements:");

        foreach (XElement element in el.Elements())
            Console.WriteLine("    {0}: {1}", element.Name, element.Value);
    }
}

How to write logs in text file when using java.util.logging.Logger

Location of log file can be control through logging.properties file. And it can be passed as JVM parameter ex : java -Djava.util.logging.config.file=/scratch/user/config/logging.properties

Details: https://docs.oracle.com/cd/E23549_01/doc.1111/e14568/handler.htm

Configuring the File handler

To send logs to a file, add FileHandler to the handlers property in the logging.properties file. This will enable file logging globally.

handlers= java.util.logging.FileHandler Configure the handler by setting the following properties:

java.util.logging.FileHandler.pattern=<home directory>/logs/oaam.log
java.util.logging.FileHandler.limit=50000
java.util.logging.FileHandler.count=1
java.util.logging.FileHandler.formatter=java.util.logging.SimpleFormatter

java.util.logging.FileHandler.pattern specifies the location and pattern of the output file. The default setting is your home directory.

java.util.logging.FileHandler.limit specifies, in bytes, the maximum amount that the logger writes to any one file.

java.util.logging.FileHandler.count specifies how many output files to cycle through.

java.util.logging.FileHandler.formatter specifies the java.util.logging formatter class that the file handler class uses to format the log messages. SimpleFormatter writes brief "human-readable" summaries of log records.


To instruct java to use this configuration file instead of $JDK_HOME/jre/lib/logging.properties:

java -Djava.util.logging.config.file=/scratch/user/config/logging.properties

How to send an email with Gmail as provider using Python?

This Works

Create Gmail APP Password!

After you create that then create a file called sendgmail.py

Then add this code:

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# =============================================================================
# Created By  : Jeromie Kirchoff
# Created Date: Mon Aug 02 17:46:00 PDT 2018
# =============================================================================
# Imports
# =============================================================================
import smtplib

# =============================================================================
# SET EMAIL LOGIN REQUIREMENTS
# =============================================================================
gmail_user = '[email protected]'
gmail_app_password = 'YOUR-GOOGLE-APPLICATION-PASSWORD!!!!'

# =============================================================================
# SET THE INFO ABOUT THE SAID EMAIL
# =============================================================================
sent_from = gmail_user
sent_to = ['[email protected]', '[email protected]']
sent_subject = "Where are all my Robot Women at?"
sent_body = ("Hey, what's up? friend!\n\n"
             "I hope you have been well!\n"
             "\n"
             "Cheers,\n"
             "Jay\n")

email_text = """\
From: %s
To: %s
Subject: %s

%s
""" % (sent_from, ", ".join(sent_to), sent_subject, sent_body)

# =============================================================================
# SEND EMAIL OR DIE TRYING!!!
# Details: http://www.samlogic.net/articles/smtp-commands-reference.htm
# =============================================================================

try:
    server = smtplib.SMTP_SSL('smtp.gmail.com', 465)
    server.ehlo()
    server.login(gmail_user, gmail_app_password)
    server.sendmail(sent_from, sent_to, email_text)
    server.close()

    print('Email sent!')
except Exception as exception:
    print("Error: %s!\n\n" % exception)

So, if you are successful, will see an image like this:

I tested by sending an email from and to myself.

Successful email sent.

Note: I have 2-Step Verification enabled on my account. App Password works with this! (for gmail smtp setup, you must go to https://support.google.com/accounts/answer/185833?hl=en and follow the below steps)

This setting is not available for accounts with 2-Step Verification enabled. Such accounts require an application-specific password for less secure apps access.

Less secure app access... This setting is not available for accounts with 2-Step Verification enabled.

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

I recently had to build a fall back system which included any number of fallback images. Here's how I did it using a simple JavaScript function.

HTML

<img src="some_image.tiff"
    onerror="fallBackImg(this);"
    data-fallIndex="1"
    data-fallback1="some_image.png"
    data-fallback2="some_image.jpg">

JavaScript

function fallBackImg(elem){
    elem.onerror = null;
    let index = +elem.dataset.fallIndex;
    elem.src = elem.dataset[`fallback${index}`];
    index++;
    elem.dataset.fallbackindex = index;
}

I feel like it's a pretty lightweight way of handling many fallback images.

In Python, when to use a Dictionary, List or Set?

Lists are what they seem - a list of values. Each one of them is numbered, starting from zero - the first one is numbered zero, the second 1, the third 2, etc. You can remove values from the list, and add new values to the end. Example: Your many cats' names.

Tuples are just like lists, but you can't change their values. The values that you give it first up, are the values that you are stuck with for the rest of the program. Again, each value is numbered starting from zero, for easy reference. Example: the names of the months of the year.

Dictionaries are similar to what their name suggests - a dictionary. In a dictionary, you have an 'index' of words, and for each of them a definition. In python, the word is called a 'key', and the definition a 'value'. The values in a dictionary aren't numbered - tare similar to what their name suggests - a dictionary. In a dictionary, you have an 'index' of words, and for each of them a definition. In python, the word is called a 'key', and the definition a 'value'. The values in a dictionary aren't numbered - they aren't in any specific order, either - the key does the same thing. You can add, remove, and modify the values in dictionaries. Example: telephone book.

Convert Pandas column containing NaNs to dtype `int`

You could use .dropna() if it is OK to drop the rows with the NaN values.

df = df.dropna(subset=['id'])

Alternatively, use .fillna() and .astype() to replace the NaN with values and convert them to int.

I ran into this problem when processing a CSV file with large integers, while some of them were missing (NaN). Using float as the type was not an option, because I might loose the precision.

My solution was to use str as the intermediate type. Then you can convert the string to int as you please later in the code. I replaced NaN with 0, but you could choose any value.

df = pd.read_csv(filename, dtype={'id':str})
df["id"] = df["id"].fillna("0").astype(int)

For the illustration, here is an example how floats may loose the precision:

s = "12345678901234567890"
f = float(s)
i = int(f)
i2 = int(s)
print (f, i, i2)

And the output is:

1.2345678901234567e+19 12345678901234567168 12345678901234567890

How to get the number of columns in a matrix?

Use the size() function.

>> size(A,2)

Ans =

   3

The second argument specifies the dimension of which number of elements are required which will be '2' if you want the number of columns.

Official documentation.

How to remove a Gitlab project?

  1. Open project
  2. Setting (In the left sidebar)
  3. General
  4. Advanced Setting (Click on Expand)
  5. Remove Project (Bottom of the Page)
  6. Confirm (By typing project name and press Confirm button)

Datatables - Setting column width

I would suggest not using pixels for sWidth, instead use percentages. Like below:

   "aoColumnDefs": [
  { "sWidth": "20%", "aTargets": [ 0 ] }, <- start from zero
  { "sWidth": "5%", "aTargets": [ 1 ] },
  { "sWidth": "10%", "aTargets": [ 2 ] },
  { "sWidth": "5%", "aTargets": [ 3 ] },
  { "sWidth": "40%", "aTargets": [ 4 ] },
  { "sWidth": "5%", "aTargets": [ 5 ] },
  { "sWidth": "15%", "aTargets": [ 6 ] }
],
     aoColumns : [
      { "sWidth": "20%"},
      { "sWidth": "5%"},
      { "sWidth": "10%"},
      { "sWidth": "5%"},
      { "sWidth": "40%"},
      { "sWidth": "5%"},
      { "sWidth": "15%"}
    ]
});

Hope it helps.

Converting .NET DateTime to JSON

If you're having trouble getting to the time information, you can try something like this:

    d.date = d.date.replace('/Date(', '');
    d.date = d.date.replace(')/', '');  
    var expDate = new Date(parseInt(d.date));

Internet Explorer 11 detection

Using this RegExp seems works for IE 10 and IE 11:

function isIE(){
    return /Trident\/|MSIE/.test(window.navigator.userAgent);
}

I do not have a IE older than IE 10 to test this.

How to convert a string from uppercase to lowercase in Bash?

If you define your variable using declare (old: typeset) then you can state the case of the value throughout the variable's use.

$ declare -u FOO=AbCxxx
$ echo $FOO
ABCXXX

"-l" does lc.

Enable IIS7 gzip

Global Gzip in HttpModule

If you don't have access to the final IIS instance (shared hosting...) you can create a HttpModule that adds this code to every HttpApplication.Begin_Request event :

HttpContext context = HttpContext.Current;
context.Response.Filter = new GZipStream(context.Response.Filter, CompressionMode.Compress);
HttpContext.Current.Response.AppendHeader("Content-encoding", "gzip");
HttpContext.Current.Response.Cache.VaryByHeaders["Accept-encoding"] = true;

Testing

Kudos, no solution is done without testing. I like to use the Firefox plugin "Liveheaders" it shows all the information about every http message between the browser and server, including compression, file size (which you could compare to the file size on the server).

Python - Convert a bytes array into JSON format

You can simply use,

import json

json.loads(my_bytes_value)

How do I reference to another (open or closed) workbook, and pull values back, in VBA? - Excel 2007

You will have to open the file in one way or another if you want to access the data within it. Obviously, one way is to open it in your Excel application instance, e.g.:-

(untested code)

Dim wbk As Workbook
Set wbk = Workbooks.Open("C:\myworkbook.xls")

' now you can manipulate the data in the workbook anyway you want, e.g. '

Dim x As Variant
x = wbk.Worksheets("Sheet1").Range("A6").Value

Call wbk.Worksheets("Sheet2").Range("A1:G100").Copy
Call ThisWorbook.Worksheets("Target").Range("A1").PasteSpecial(xlPasteValues)
Application.CutCopyMode = False

' etc '

Call wbk.Close(False)

Another way to do it would be to use the Excel ADODB provider to open a connection to the file and then use SQL to select data from the sheet you want, but since you are anyway working from within Excel I don't believe there is any reason to do this rather than just open the workbook. Note that there are optional parameters for the Workbooks.Open() method to open the workbook as read-only, etc.

What is the Java ?: operator called and what does it do?

Yes, it is a shorthand form of

int count;
if (isHere)
    count = getHereCount(index);
else
    count = getAwayCount(index);

It's called the conditional operator. Many people (erroneously) call it the ternary operator, because it's the only ternary (three-argument) operator in Java, C, C++, and probably many other languages. But theoretically there could be another ternary operator, whereas there can only be one conditional operator.

The official name is given in the Java Language Specification:

§15.25 Conditional Operator ? :

The conditional operator ? : uses the boolean value of one expression to decide which of two other expressions should be evaluated.

Note that both branches must lead to methods with return values:

It is a compile-time error for either the second or the third operand expression to be an invocation of a void method.

In fact, by the grammar of expression statements (§14.8), it is not permitted for a conditional expression to appear in any context where an invocation of a void method could appear.

So, if doSomething() and doSomethingElse() are void methods, you cannot compress this:

if (someBool)
    doSomething();
else
    doSomethingElse();

into this:

someBool ? doSomething() : doSomethingElse();

Simple words:

booleanCondition ? executeThisPartIfBooleanConditionIsTrue : executeThisPartIfBooleanConditionIsFalse 

Docker is installed but Docker Compose is not ? why?

I'm on debian, I found something quite natural to do :

apt-get install docker-compose

and it did the job (not tested on centos)

Proper way to concatenate variable strings

Good question. But I think there is no good answer which fits your criteria. The best I can think of is to use an extra vars file.

A task like this:

- include_vars: concat.yml

And in concat.yml you have your definition:

newvar: "{{ var1 }}-{{ var2 }}-{{ var3 }}"

Interview question: Check if one string is a rotation of other string

First make sure s1 and s2 are of the same length. Then check to see if s2 is a substring of s1 concatenated with s1:

algorithm checkRotation(string s1, string s2) 
  if( len(s1) != len(s2))
    return false
  if( substring(s2,concat(s1,s1))
    return true
  return false
end

In Java:

boolean isRotation(String s1,String s2) {
    return (s1.length() == s2.length()) && ((s1+s1).indexOf(s2) != -1);
}

Execute the setInterval function without delay the first time

Here's a simple version for novices without all the messing around. It just declares the function, calls it, then starts the interval. That's it.

_x000D_
_x000D_
//Declare your function here_x000D_
function My_Function(){_x000D_
  console.log("foo");_x000D_
}    _x000D_
_x000D_
//Call the function first_x000D_
My_Function();_x000D_
_x000D_
//Set the interval_x000D_
var interval = window.setInterval( My_Function, 500 );
_x000D_
_x000D_
_x000D_

Passing data through intent using Serializable

Try to pass the serializable list using Bundle.Serializable:

Bundle bundle = new Bundle();
bundle.putSerializable("value", all_thumbs);
intent.putExtras(bundle);

And in SomeClass Activity get it as:

Intent intent = this.getIntent();
Bundle bundle = intent.getExtras();

List<Thumbnail> thumbs=
               (List<Thumbnail>)bundle.getSerializable("value");

A network-related or instance-specific error occurred while establishing a connection to SQL Server

Sql Server fire this error when your application don't have enough rights to access the database. there are several reason about this error . To fix this error you should follow the following instruction.

  1. Try to connect sql server from your server using management studio . if you use windows authentication to connect sql server then set your application pool identity to server administrator .

  2. if you use sql server authentication then check you connection string in web.config of your web application and set user id and password of sql server which allows you to log in .

  3. if your database in other server(access remote database) then first of enable remote access of sql server form sql server property from sql server management studio and enable TCP/IP form sql server configuration manager .

  4. after doing all these stuff and you still can't access the database then check firewall of server form where you are trying to access the database and add one rule in firewall to enable port of sql server(by default sql server use 1433 , to check port of sql server you need to check sql server configuration manager network protocol TCP/IP port).

  5. if your sql server is running on named instance then you need to write port number with sql serer name for example 117.312.21.21/nameofsqlserver,1433.

  6. If you are using cloud hosting like amazon aws or microsoft azure then server or instance will running behind cloud firewall so you need to enable 1433 port in cloud firewall if you have default instance or specific port for sql server for named instance.

  7. If you are using amazon RDS or SQL azure then you need to enable port from security group of that instance.

  8. If you are accessing sql server through sql server authentication mode them make sure you enabled "SQL Server and Windows Authentication Mode" sql server instance property. enter image description here

    1. Restart your sql server instance after making any changes in property as some changes will require restart.

if you further face any difficulty then you need to provide more information about your web site and sql server .

Plotting multiple curves same graph and same scale

My solution is to use ggplot2. It takes care of these types of things automatically. The biggest thing is to arrange the data appropriately.

y1 <- c(100, 200, 300, 400, 500)
y2 <- c(1, 2, 3, 4, 5)
x <- c(1, 2, 3, 4, 5)
df <- data.frame(x=rep(x,2), y=c(y1, y2), class=c(rep("y1", 5), rep("y2", 5)))

Then use ggplot2 to plot it

library(ggplot2)
ggplot(df, aes(x=x, y=y, color=class)) + geom_point()

This is saying plot the data in df, and separate the points by class.

The plot generated isenter image description here

How to clone an InputStream?

You can't clone it, and how you are going to solve your problem depends on what the source of the data is.

One solution is to read all data from the InputStream into a byte array, and then create a ByteArrayInputStream around that byte array, and pass that input stream into your method.

Edit 1: That is, if the other method also needs to read the same data. I.e you want to "reset" the stream.

Javascript setInterval not working

Change setInterval("func",10000) to either setInterval(funcName, 10000) or setInterval("funcName()",10000). The former is the recommended method.

Building with Lombok's @Slf4j and Intellij: Cannot find symbol log

If you are using maven, try adding Lombok path to maven-compiler-plugin list of annotation processor as shown below.

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.8.1</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
                <annotationProcessorPaths>
                    <path>
                        <groupId>org.mapstruct</groupId>
                        <artifactId>mapstruct-processor</artifactId>
                        <version>1.3.0.Final</version>
                    </path>
                    <path>
                        <groupId>org.projectlombok</groupId>
                        <artifactId>lombok</artifactId>
                        <version>1.18.10</version>
                    </path>
                </annotationProcessorPaths>
            </configuration>
        </plugin>

Change the version as per your version of Lombok. Other than that ensure you have done the following

  • installed the Lombok plugin for Intellij.
  • Enabled annotation processing for your project under File -> Settings -> Build, Execution, Deployment -> Compiler -> Annotation Processor. For me both, Obtain processors from project classpath and Processor path is working. So not sure what will work for you, but try whichever works.

And rather than shooting in the dark for hours. Reading a little bit how annotation processors work and are used by compiler may help. so have quick read below.

http://hannesdorfmann.com/annotation-processing/annotationprocessing101

How to dynamically build a JSON object with Python?

  • json.loads take a string as input and returns a dictionary as output.
  • json.dumps take a dictionary as input and returns a string as output.

If you need to convert JSON data into a python object, it can do so with Python3, in one line without additional installations, using SimpleNamespace and object_hook:

from string

import json
from types import SimpleNamespace

string = '{"foo":3, "bar":{"x":1, "y":2}}'

# Parse JSON into an object with attributes corresponding to dict keys.
x = json.loads(string, object_hook=lambda d: SimpleNamespace(**d))

print(x.foo)
print(x.bar.x)
print(x.bar.y)

output:

3
1
2

from file:

JSON object: data.json

{
    "foo": 3,
    "bar": {
        "x": 1,
        "y": 2
    }
}
import json
from types import SimpleNamespace

with open("data.json") as fh:
    string = fh.read()

# Parse JSON into an object with attributes corresponding to dict keys.
x = json.loads(string, object_hook=lambda d: SimpleNamespace(**d))

print(x.foo)
print(x.bar.x)
print(x.bar.y)

output:

3
1
2

from requests

import json
from types import SimpleNamespace
import requests

r = requests.get('https://api.github.com/users/MilovanTomasevic')

# Parse JSON into an object with attributes corresponding to dict keys.
x = json.loads(r.text, object_hook=lambda d: SimpleNamespace(**d))

print(x.name)
print(x.company)
print(x.blog)

output:

Milovan Tomaševic
NLB
milovantomasevic.com

For more beautiful and faster access to JSON response from API, take a look at this response.

How to make Java 6, which fails SSL connection with "SSL peer shut down incorrectly", succeed like Java 7?

It seems that in the debug log for Java 6 the request is send in SSLv2 format.

main, WRITE: SSLv2 client hello message, length = 110

This is not mentioned as enabled by default in Java 7.
Change the client to use SSLv3 and above to avoid such interoperability issues.

Look for differences in JSSE providers in Java 7 and Java 6

ActionLink htmlAttributes

The problem is that your anonymous object property data-icon has an invalid name. C# properties cannot have dashes in their names. There are two ways you can get around that:

Use an underscore instead of dash (MVC will automatically replace the underscore with a dash in the emitted HTML):

@Html.ActionLink("Edit", "edit", "markets",
      new { id = 1 },
      new {@class="ui-btn-right", data_icon="gear"})

Use the overload that takes in a dictionary:

@Html.ActionLink("Edit", "edit", "markets",
      new { id = 1 },
      new Dictionary<string, object> { { "class", "ui-btn-right" }, { "data-icon", "gear" } });

Finding sum of elements in Swift array

Swift 3

If you have an array of generic objects and you want to sum some object property then:

class A: NSObject {
    var value = 0
    init(value: Int) {
       self.value = value
    }
}

let array = [A(value: 2), A(value: 4)]      
let sum = array.reduce(0, { $0 + $1.value })
//                           ^       ^
//                        $0=result  $1=next A object
print(sum) // 6 

Despite of the shorter form, many times you may prefer the classic for-cycle:

let array = [A(value: 2), A(value: 4)]
var sum = 0
array.forEach({ sum += $0.value}) 
// or
for element in array {
   sum += element.value
}

Get only part of an Array in Java?

public static int[] range(int[] array, int start, int end){
        int returner[] = new int[end-start];
        for(int x = 0; x <= end-start-1; x++){
            returner[x] = array[x+start];
        }
        return returner;
    }

this is a way to do the same thing as Array.copyOfRange but without importing anything

Executing a stored procedure within a stored procedure

Inline Stored procedure we using as per our need. Example like different Same parameter with different values we have to use in queries..

Create Proc SP1
(
 @ID int,
 @Name varchar(40)
 -- etc parameter list, If you don't have any parameter then no need to pass.
 )

  AS
  BEGIN

  -- Here we have some opereations

 -- If there is any Error Before Executing SP2 then SP will stop executing.

  Exec SP2 @ID,@Name,@SomeID OUTPUT 

 -- ,etc some other parameter also we can use OutPut parameters like 

 -- @SomeID is useful for some other operations for condition checking insertion etc.

 -- If you have any Error in you SP2 then also it will stop executing.

 -- If you want to do any other operation after executing SP2 that we can do here.

END

How to convert a string to lower or upper case in Ruby

The .swapcase method transforms the uppercase latters in a string to lowercase and the lowercase letters to uppercase.

'TESTING'.swapcase #=> testing
'testing'.swapcase #=> TESTING

How to check whether a string contains a substring in Ruby

If case is irrelevant, then a case-insensitive regular expression is a good solution:

'aBcDe' =~ /bcd/i  # evaluates as true

This will also work for multi-line strings.

See Ruby's Regexp class for more information.

How to Get the HTTP Post data in C#?

This code will list out all the form variables that are being sent in a POST. This way you can see if you have the proper names of the post values.

string[] keys = Request.Form.AllKeys;
for (int i= 0; i < keys.Length; i++) 
{
   Response.Write(keys[i] + ": " + Request.Form[keys[i]] + "<br>");
}

Detecting request type in PHP (GET, POST, PUT or DELETE)

You can use getenv function and don't have to work with a $_SERVER variable:

getenv('REQUEST_METHOD');

More info:

http://php.net/manual/en/function.getenv.php

PHP how to get local IP of system

$_SERVER['REMOTE_ADDR']
  • PHP_SELF Returns the filename of the current script with the path relative to the root

  • SERVER_PROTOCOL Returns the name and revision of the page-requested protocol

  • REQUEST_METHOD Returns the request method used to access the page

  • DOCUMENT_ROOT Returns the root directory under which the current script is executing

SQL Server query to find all current database names

You can also use these ways:

EXEC sp_helpdb

and:

SELECT name FROM sys.sysdatabases

Recommended Read:

Don't forget to have a look at sysdatabases VS sys.sysdatabases

A similar thread.

process.waitFor() never returns

Here is a method that works for me. NOTE: There is some code within this method that may not apply to you, so try and ignore it. For example "logStandardOut(...), git-bash, etc".

private String exeShellCommand(String doCommand, String inDir, boolean ignoreErrors) {
logStandardOut("> %s", doCommand);

ProcessBuilder builder = new ProcessBuilder();
StringBuilder stdOut = new StringBuilder();
StringBuilder stdErr = new StringBuilder();

boolean isWindows = System.getProperty("os.name").toLowerCase().startsWith("windows");
if (isWindows) {
  String gitBashPathForWindows = "C:\\Program Files\\Git\\bin\\bash";
  builder.command(gitBashPathForWindows, "-c", doCommand);
} else {
  builder.command("bash", "-c", doCommand);
}

//Do we need to change dirs?
if (inDir != null) {
  builder.directory(new File(inDir));
}

//Execute it
Process process = null;
BufferedReader brStdOut;
BufferedReader brStdErr;
try {
  //Start the command line process
  process = builder.start();

  //This hangs on a large file
  // https://stackoverflow.com/questions/5483830/process-waitfor-never-returns
  //exitCode = process.waitFor();

  //This will have both StdIn and StdErr
  brStdOut = new BufferedReader(new InputStreamReader(process.getInputStream()));
  brStdErr = new BufferedReader(new InputStreamReader(process.getErrorStream()));

  //Get the process output
  String line = null;
  String newLineCharacter = System.getProperty("line.separator");

  while (process.isAlive()) {
    //Read the stdOut
    while ((line = brStdOut.readLine()) != null) {
      stdOut.append(line + newLineCharacter);
    }

    //Read the stdErr
    while ((line = brStdErr.readLine()) != null) {
      stdErr.append(line + newLineCharacter);
    }

    //Nothing else to read, lets pause for a bit before trying again
    process.waitFor(100, TimeUnit.MILLISECONDS);
  }

  //Read anything left, after the process exited
  while ((line = brStdOut.readLine()) != null) {
    stdOut.append(line + newLineCharacter);
  }

  //Read anything left, after the process exited
  while ((line = brStdErr.readLine()) != null) {
    stdErr.append(line + newLineCharacter);
  }

  //cleanup
  if (brStdOut != null) {
    brStdOut.close();
  }

  if (brStdErr != null) {
    brStdOut.close();
  }

  //Log non-zero exit values
  if (!ignoreErrors && process.exitValue() != 0) {
    String exMsg = String.format("%s%nprocess.exitValue=%s", stdErr, process.exitValue());
    throw new ExecuteCommandException(exMsg);
  }

} catch (ExecuteCommandException e) {
  throw e;
} catch (Exception e) {
  throw new ExecuteCommandException(stdErr.toString(), e);
} finally {
  //Log the results
  logStandardOut(stdOut.toString());
  logStandardError(stdErr.toString());
}

return stdOut.toString();

}

org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update

You can find your sample code completely here: http://www.java2s.com/Code/Java/Hibernate/OneToManyMappingbasedonSet.htm

Have a look and check the differences. specially the even_id in :

<set name="attendees" cascade="all">
    <key column="event_id"/>
    <one-to-many class="Attendee"/>
</set> 

Best way to check if a drop down list contains a value?

If the function return Nothing, you can try this below

if (ddlCustomerNumber.Items.FindByText(
    GetCustomerNumberCookie().ToString()) != Nothing)
{
...
}

How to slice a Pandas Data Frame by position?

dataframe[:n] - Will return first n-1 rows

How to toggle (hide / show) sidebar div using jQuery

$(document).ready(function () {
    $(".trigger").click(function () {
        $("#sidebar").toggle("fast");
        $("#sidebar").toggleClass("active");
        return false;
    });
});


<div>
    <a class="trigger" href="#">
        <img id="icon-menu" alt='menu' height='50' src="Images/Push Pin.png" width='50' />
    </a>
</div>
<div id="sidebar">
</div>

Instead #sidebar give the id of ur div.

How do MySQL indexes work?

In MySQL InnoDB, there are two types of index.

  1. Primary key which is called clustered index. Index key words are stored with real record data in the B+Tree leaf node.

  2. Secondary key which is non clustered index. These index only store primary key's key words along with their own index key words in the B+Tree leaf node. So when searching from secondary index, it will first find its primary key index key words and scan the primary key B+Tree to find the real data records. This will make secondary index slower compared to primary index search. However, if the select columns are all in the secondary index, then no need to look up primary index B+Tree again. This is called covering index.

How can I tell jackson to ignore a property for which I don't have control over the source code?

Using Java Class

new ObjectMapper().configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)

Using Annotation

@JsonIgnoreProperties(ignoreUnknown=true)

How to check if any fields in a form are empty in php

Specify POST method in form
<form name="registrationform" action="register.php" method="post">


your form code

</form>

Validate email with a regex in jQuery

function mailValidation(val) {
    var expr = /^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$/;

    if (!expr.test(val)) {
        $('#errEmail').text('Please enter valid email.');
    }
    else {
        $('#errEmail').hide();
    }
}

How do I get current scope dom-element in AngularJS controller?

The better and correct solution is to have a directive. The scope is the same, whether in the controller of the directive or the main controller. Use $element to do DOM operations. The method defined in the directive controller is accessible in the main controller.

Example, finding a child element:

var app = angular.module('myapp', []);
app.directive("testDir", function () {
    function link(scope, element) { 

    }
    return {
        restrict: "AE", 
        link: link, 
        controller:function($scope,$element){
            $scope.name2 = 'this is second name';
            var barGridSection = $element.find('#barGridSection'); //helps to find the child element.
    }
    };
})

app.controller('mainController', function ($scope) {
$scope.name='this is first name'
});

Maven in Eclipse: step by step installation

The latest version of Eclipse (Luna) and Spring Tool Suite (STS) come pre-packaged with support for Maven, GIT and Java 8.

Defining static const integer members in class definition

As of C++11 you can use:

static constexpr int N = 10;

This theoretically still requires you to define the constant in a .cpp file, but as long as you don't take the address of N it is very unlikely that any compiler implementation will produce an error ;).

target input by type and name (selector)

You want a multiple attribute selector

$("input[type='checkbox'][name='ProductCode']").each(function(){ ...

or

$("input:checkbox[name='ProductCode']").each(function(){ ...

It would be better to use a CSS class to identify those that you want to select however as a lot of the modern browsers implement the document.getElementsByClassName method which will be used to select elements and be much faster than selecting by the name attribute

What is the difference between T(n) and O(n)?

one is Big "O"

one is Big Theta

http://en.wikipedia.org/wiki/Big_O_notation

Big O means your algorithm will execute in no more steps than in given expression(n^2)

Big Omega means your algorithm will execute in no fewer steps than in the given expression(n^2)

When both condition are true for the same expression, you can use the big theta notation....

What is the difference between putting a property on application.yml or bootstrap.yml in spring boot?

Bootstrap.yml is the first file loaded when you start spring boot application and application.property is loaded when application starts. So, you keep, may be your config server's credentials etc., in bootstrap.yml which is required during loading application and then in application.properties you keep may be database URL etc.

What dependency is missing for org.springframework.web.bind.annotation.RequestMapping?

This solution WORKS , I had the same issue and after hours I came up to this:

(1) Go to your pom.xml

(2) Add this Dependency :

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>4.1.6.RELEASE</version>
    </dependency>


(3) Run your Project

How to use Sublime over SSH

This is the easiest way to locally edit files which live on remote host where you have previously setup ssh to remote IP

# issue on local box

sudo apt-get install sshfs   # on local host install sshfs ( linux )

# on local box create secure mount of remote directory

export REMOTE_IP=107.170.58.249 # remote host IP

sshfs myremoteuserid@${REMOTE_IP}:/your/remote/dir  /your/local/dir # for example

Done !!!

Now on local host just start editing files ... when you list dir locally it may not list anything until you cd into subdir or list a specific file ... lazy loading ... this does not impact editing files

subl /your/local/dir/magnum_opus.go # local file edit using sublime text

so above is actually editing remote file at

/your/remote/dir/magnum_opus.go  # remote file on box $REMOTE_IP

For OSX or Windows see this tut from the kind folk over on Digital Ocean

How can I get a list of all open named pipes in Windows?

I stumbled across a feature in Chrome that will list out all open named pipes by navigating to "file://.//pipe//"

Since I can't seem to find any reference to this and it has been very helpful to me, I thought I might share.

A non-blocking read on a subprocess.PIPE in Python

The select module helps you determine where the next useful input is.

However, you're almost always happier with separate threads. One does a blocking read the stdin, another does wherever it is you don't want blocked.

How to set Internet options for Android emulator?

for the records since this is an old post and since nobody mentioned it, check if you forgot (as I did) to set the android.permission.INTERNET flag in AndroidManifest.xml as, i.e.:

    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.google.android.webviewdemo">
<uses-permission android:name="android.permission.INTERNET"/>
    <application android:icon="@drawable/icon">
        <activity android:name=".WebViewDemo" android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest> 

catch forEach last iteration

const arr= [1, 2, 3]
arr.forEach(function(element){
 if(arr[arr.length-1] === element){
  console.log("Last Element")
 }
})

SVG drop shadow using css3

Here's an example of applying dropshadow to some svg using the 'filter' property. If you want to control the opacity of the dropshadow have a look at this example. The slope attribute controls how much opacity to give to the dropshadow.

Relevant bits from the example:

<filter id="dropshadow" height="130%">
  <feGaussianBlur in="SourceAlpha" stdDeviation="3"/> <!-- stdDeviation is how much to blur -->
  <feOffset dx="2" dy="2" result="offsetblur"/> <!-- how much to offset -->
  <feComponentTransfer>
    <feFuncA type="linear" slope="0.5"/> <!-- slope is the opacity of the shadow -->
  </feComponentTransfer>
  <feMerge> 
    <feMergeNode/> <!-- this contains the offset blurred image -->
    <feMergeNode in="SourceGraphic"/> <!-- this contains the element that the filter is applied to -->
  </feMerge>
</filter>
<circle r="10" style="filter:url(#dropshadow)"/>

Box-shadow is defined to work on CSS boxes (read: rectangles), while svg is a bit more expressive than just rectangles. Read the SVG Primer to learn a bit more about what you can do with SVG filters.

Rails 3 migrations: Adding reference column?

With the two previous steps stated above, you're still missing the foreign key constraint. This should work:

  class AddUserReferenceToTester < ActiveRecord::Migration
      def change
          add_column :testers, :user_id, :integer, references: :users
      end
  end

hibernate - get id after save object

The session.save(object) returns the id of the object, or you could alternatively call the id getter method after performing a save.

Save() return value:

Serializable save(Object object) throws HibernateException

Returns:

the generated identifier

Getter method example:

UserDetails entity:

@Entity
public class UserDetails {
    @Id
    @GeneratedValue
    private int id;
    private String name;

    // Constructor, Setters & Getters
}

Logic to test the id's :

Session session = HibernateUtil.getSessionFactory().getCurrentSession();
session.getTransaction().begin();
UserDetails user1 = new UserDetails("user1");
UserDetails user2 = new UserDetails("user2");

//int userId = (Integer) session.save(user1); // if you want to save the id to some variable

System.out.println("before save : user id's = "+user1.getId() + " , " + user2.getId());

session.save(user1);
session.save(user2);

System.out.println("after save : user id's = "+user1.getId() + " , " + user2.getId());

session.getTransaction().commit();

Output of this code:

before save : user id's = 0 , 0

after save : user id's = 1 , 2

As per this output, you can see that the id's were not set before we save the UserDetails entity, once you save the entities then Hibernate set's the id's for your objects - user1 and user2

Moving Panel in Visual Studio Code to right side

As of October 2018 (version 1.29) the button in @mvvijesh's answer no longer exists.

You now have 2 options. Right click the panel's toolbar (nowhere else on the panel will work) and choose "move panel right/bottom":

Or choose "View: Toggle Panel Position" from the command palette.

Source: VSCode update notes: https://code.visualstudio.com/updates/v1_29#_panel-position-button-to-context-menu

How do I get a file extension in PHP?

Here is an example. Suppose $filename is "example.txt",

$ext = substr($filename, strrpos($filename, '.', -1), strlen($filename));

So $ext will be ".txt".

How to get HttpContext.Current in ASP.NET Core?

Necromancing.
YES YOU CAN, and this is how.
A secret tip for those migrating large junks chunks of code:
The following method is an evil carbuncle of a hack which is actively engaged in carrying out the express work of satan (in the eyes of .NET Core framework developers), but it works:

In public class Startup

add a property

public IConfigurationRoot Configuration { get; }

And then add a singleton IHttpContextAccessor to DI in ConfigureServices.

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddSingleton<Microsoft.AspNetCore.Http.IHttpContextAccessor, Microsoft.AspNetCore.Http.HttpContextAccessor>();

Then in Configure

    public void Configure(
              IApplicationBuilder app
             ,IHostingEnvironment env
             ,ILoggerFactory loggerFactory
    )
    {

add the DI Parameter IServiceProvider svp, so the method looks like:

    public void Configure(
           IApplicationBuilder app
          ,IHostingEnvironment env
          ,ILoggerFactory loggerFactory
          ,IServiceProvider svp)
    {

Next, create a replacement class for System.Web:

namespace System.Web
{

    namespace Hosting
    {
        public static class HostingEnvironment 
        {
            public static bool m_IsHosted;

            static HostingEnvironment()
            {
                m_IsHosted = false;
            }

            public static bool IsHosted
            {
                get
                {
                    return m_IsHosted;
                }
            }
        }
    }


    public static class HttpContext
    {
        public static IServiceProvider ServiceProvider;

        static HttpContext()
        { }


        public static Microsoft.AspNetCore.Http.HttpContext Current
        {
            get
            {
                // var factory2 = ServiceProvider.GetService<Microsoft.AspNetCore.Http.IHttpContextAccessor>();
                object factory = ServiceProvider.GetService(typeof(Microsoft.AspNetCore.Http.IHttpContextAccessor));

                // Microsoft.AspNetCore.Http.HttpContextAccessor fac =(Microsoft.AspNetCore.Http.HttpContextAccessor)factory;
                Microsoft.AspNetCore.Http.HttpContext context = ((Microsoft.AspNetCore.Http.HttpContextAccessor)factory).HttpContext;
                // context.Response.WriteAsync("Test");

                return context;
            }
        }


    } // End Class HttpContext 


}

Now in Configure, where you added the IServiceProvider svp, save this service provider into the static variable "ServiceProvider" in the just created dummy class System.Web.HttpContext (System.Web.HttpContext.ServiceProvider)

and set HostingEnvironment.IsHosted to true

System.Web.Hosting.HostingEnvironment.m_IsHosted = true;

this is essentially what System.Web did, just that you never saw it (I guess the variable was declared as internal instead of public).

// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IServiceProvider svp)
{
    loggerFactory.AddConsole(Configuration.GetSection("Logging"));
    loggerFactory.AddDebug();

    ServiceProvider = svp;
    System.Web.HttpContext.ServiceProvider = svp;
    System.Web.Hosting.HostingEnvironment.m_IsHosted = true;


    app.UseCookieAuthentication(new CookieAuthenticationOptions()
    {
        AuthenticationScheme = "MyCookieMiddlewareInstance",
        LoginPath = new Microsoft.AspNetCore.Http.PathString("/Account/Unauthorized/"),
        AccessDeniedPath = new Microsoft.AspNetCore.Http.PathString("/Account/Forbidden/"),
        AutomaticAuthenticate = true,
        AutomaticChallenge = true,
        CookieSecure = Microsoft.AspNetCore.Http.CookieSecurePolicy.SameAsRequest

       , CookieHttpOnly=false

    });

Like in ASP.NET Web-Forms, you'll get a NullReference when you're trying to access a HttpContext when there is none, such as it used to be in Application_Start in global.asax.

I stress again, this only works if you actually added

services.AddSingleton<Microsoft.AspNetCore.Http.IHttpContextAccessor, Microsoft.AspNetCore.Http.HttpContextAccessor>();

like I wrote you should.
Welcome to the ServiceLocator pattern within the DI pattern ;)
For risks and side effects, ask your resident doctor or pharmacist - or study the sources of .NET Core at github.com/aspnet, and do some testing.


Perhaps a more maintainable method would be adding this helper class

namespace System.Web
{

    public static class HttpContext
    {
        private static Microsoft.AspNetCore.Http.IHttpContextAccessor m_httpContextAccessor;


        public static void Configure(Microsoft.AspNetCore.Http.IHttpContextAccessor httpContextAccessor)
        {
            m_httpContextAccessor = httpContextAccessor;
        }


        public static Microsoft.AspNetCore.Http.HttpContext Current
        {
            get
            {
                return m_httpContextAccessor.HttpContext;
            }
        }


    }


}

And then calling HttpContext.Configure in Startup->Configure

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IServiceProvider svp)
{
    loggerFactory.AddConsole(Configuration.GetSection("Logging"));
    loggerFactory.AddDebug();


    System.Web.HttpContext.Configure(app.ApplicationServices.
        GetRequiredService<Microsoft.AspNetCore.Http.IHttpContextAccessor>()
    );

Empty or Null value display in SSRS text boxes

Either in SQL or in report code (as per adolf garlic's function suggestion)

At this moment in time, I'd do it in the report. I have very few reports against a busy OLTP server and an underwhelmed report server. If I had a different mix I'd do it in SQL.

Either way is acceptable...

HTML input file selection event not firing upon selecting the same file

handleChange({target}) {
    const files = target.files
    target.value = ''
}

How to sign in kubernetes dashboard?

Download https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/alternative/kubernetes-dashboard.yaml

add

type: NodePort for the Service

And then run this command:

kubectl apply -f kubernetes-dashboard.yaml

Find the exposed port with the command :

kubectl get services -n kube-system

You should be able to get the dashboard at http://hostname:exposedport/ with no authentication

The listener supports no services

The database registers its service name(s) with the listener when it starts up. If it is unable to do so then it tries again periodically - so if the listener starts after the database then there can be a delay before the service is recognised.

If the database isn't running, though, nothing will have registered the service, so you shouldn't expect the listener to know about it - lsnrctl status or lsnrctl services won't report a service that isn't registered yet.

You can start the database up without the listener; from the Oracle account and with your ORACLE_HOME, ORACLE_SID and PATH set you can do:

sqlplus /nolog

Then from the SQL*Plus prompt:

connect / as sysdba
startup

Or through the Grid infrastructure, from the grid account, use the srvctl start database command:

srvctl start database -d db_unique_name [-o start_options] [-n node_name]

You might want to look at whether the database is set to auto-start in your oratab file, and depending on what you're using whether it should have started automatically. If you're expecting it to be running and it isn't, or you try to start it and it won't come up, then that's a whole different scenario - you'd need to look at the error messages, alert log, possibly trace files etc. to see exactly why it won't start, and if you can't figure it out, maybe ask on Database Adminsitrators rather than on Stack Overflow.


If the database can't see +DATA then ASM may not be running; you can see how to start that here; or using srvctl start asm. As the documentation says, make sure you do that from the grid home, not the database home.

How to get the ASCII value of a character

You are looking for:

ord()

In Python, how do you convert a `datetime` object to seconds?

To get the Unix time (seconds since January 1, 1970):

>>> import datetime, time
>>> t = datetime.datetime(2011, 10, 21, 0, 0)
>>> time.mktime(t.timetuple())
1319148000.0

How do I center this form in css?

Another solution (without a wrapper) would be to set the form to display: table, which would make it act like a table so it would have the width of its largest child, and then apply margin: 0 auto to center it.

form {
    display: table;
    margin: 0 auto;
}

Credit goes to: https://stackoverflow.com/a/49378738/7841955

CSS hexadecimal RGBA?

I found the answer after posting the enhancement to the question. Sorry!

MS Excel helped!

simply add the Hex prefix to the hex colour value to add an alpha that has the equivalent opacity as the % value.

(in rbga the percentage opacity is expressed as a decimal as mentioned above)

Opacity %   255 Step        2 digit HEX prefix
0%          0.00            00
5%          12.75           0C
10%         25.50           19
15%         38.25           26
20%         51.00           33
25%         63.75           3F
30%         76.50           4C
35%         89.25           59
40%         102.00          66
45%         114.75          72
50%         127.50          7F
55%         140.25          8C
60%         153.00          99
65%         165.75          A5
70%         178.50          B2
75%         191.25          BF
80%         204.00          CC
85%         216.75          D8
90%         229.50          E5
95%         242.25          F2
100%        255.00          FF

How can I SELECT multiple columns within a CASE WHEN on SQL Server?

Actually you can do it.

Although, someone should note that repeating the CASE statements are not bad as it seems. SQL Server's query optimizer is smart enough to not execute the CASE twice so that you won't get any performance hit because of that.

Additionally, someone might use the following logic to not repeat the CASE (if it suits you..)

INSERT INTO dbo.T1
(
    Col1,
    Col2,
    Col3
)
SELECT
    1,
    SUBSTRING(MyCase.MergedColumns, 0, CHARINDEX('%', MyCase.MergedColumns)),
    SUBSTRING(MyCase.MergedColumns, CHARINDEX('%', MyCase.MergedColumns) + 1, LEN(MyCase.MergedColumns) - CHARINDEX('%', MyCase.MergedColumns))
FROM
    dbo.T1 t
LEFT OUTER JOIN
(
    SELECT CASE WHEN 1 = 1 THEN '2%3' END MergedColumns
) AS MyCase ON 1 = 1

This will insert the values (1, 2, 3) for each record in the table T1. This uses a delimiter '%' to split the merged columns. You can write your own split function depending on your needs (e.g. for handling null records or using complex delimiter for varchar fields etc.). But the main logic is that you should join the CASE statement and select from the result set of the join with using a split logic.

Create 3D array using Python

The right way would be

[[[0 for _ in range(n)] for _ in range(n)] for _ in range(n)]

(What you're trying to do should be written like (for NxNxN)

[[[0]*n]*n]*n

but that is not correct, see @Adaman comment why).

How to get http headers in flask?

If any one's trying to fetch all headers that were passed then just simply use:

dict(request.headers)

it gives you all the headers in a dict from which you can actually do whatever ops you want to. In my use case I had to forward all headers to another API since the python API was a proxy

How to split a string after specific character in SQL Server and update this value to specific column

From: http://www.sql-server-helper.com/error-messages/msg-536.aspx

To use function LEFT if not all data is in the form '1/12' you need this in the second line above:

Set Col2 = LEFT(Col1, ISNULL(NULLIF(CHARINDEX('/', Col1) - 1, -1), LEN(Col1)))

User Authentication in ASP.NET Web API

I am working on a MVC5/Web API project and needed to be able to get authorization for the Web Api methods. When my index view is first loaded I make a call to the 'token' Web API method which I believe is created automatically.

The client side code (CoffeeScript) to get the token is:

getAuthenticationToken = (username, password) ->
    dataToSend = "username=" + username + "&password=" + password
    dataToSend += "&grant_type=password"
    $.post("/token", dataToSend).success saveAccessToken

If successful the following is called, which saves the authentication token locally:

saveAccessToken = (response) ->
    window.authenticationToken = response.access_token

Then if I need to make an Ajax call to a Web API method that has the [Authorize] tag I simply add the following header to my Ajax call:

{ "Authorization": "Bearer " + window.authenticationToken }

Downloading video from YouTube

To all interested:

The "Coding for fun" book's chapter 4 "InnerTube: Download, Convert, and Sync YouTube Videos" deals with the topic. The code and discussion are at http://www.c4fbook.com/InnerTube.

[PLEASE BEWARE] While the overall concepts are valid some years after the publication, non-documented details of the youtube internals the project relies on can have changed (see the comment at the bottom of the page behind the second link).

gcc warning" 'will be initialized after'

The order of initialization doesn’t matter. All fields are initialized in the order of their definition in their class/struct. But if the order in initialization list is different gcc/g++ generate this warning. Only change the initialization order to avoid this warning. But you can't define field using in initialization before its construct. It will be a runtime error. So you change the order of definition. Be careful and keep attention!

How to create a List with a dynamic object type

It appears you might be a bit confused as to how the .Add method works. I will refer directly to your code in my explanation.

Basically in C#, the .Add method of a List of objects does not COPY new added objects into the list, it merely copies a reference to the object (it's address) into the List. So the reason every value in the list is pointing to the same value is because you've only created 1 new DyObj. So your list essentially looks like this.

DyObjectsList[0] = &DyObj; // pointing to DyObj
DyObjectsList[1] = &DyObj; // pointing to the same DyObj
DyObjectsList[2] = &DyObj; // pointing to the same DyObj

...

The easiest way to fix your code is to create a new DyObj for every .Add. Putting the new inside of the block with the .Add would accomplish this goal in this particular instance.

var DyObjectsList = new List<dynamic>; 
if (condition1) { 
    dynamic DyObj = new ExpandoObject(); 
    DyObj.Required = true; 
    DyObj.Message = "Message 1"; 
    DyObjectsList .Add(DyObj); 
} 
if (condition2) { 
    dynamic DyObj = new ExpandoObject(); 
    DyObj.Required = false; 
    DyObj.Message = "Message 2"; 
    DyObjectsList .Add(DyObj); 
} 

your resulting List essentially looks like this

DyObjectsList[0] = &DyObj0; // pointing to a DyObj
DyObjectsList[1] = &DyObj1; // pointing to a different DyObj
DyObjectsList[2] = &DyObj2; // pointing to another DyObj

Now in some other languages this approach wouldn't work, because as you leave the block, the objects declared in the scope of the block could go out of scope and be destroyed. Thus you would be left with a collection of pointers, pointing to garbage.

However in C#, if a reference to the new DyObjs exists when you leave the block (and they do exist in your List because of the .Add operation) then C# does not release the memory associated with that pointer. Therefore the Objects you created in that block persist and your List contains pointers to valid objects and your code works.

inverting image in Python with OpenCV

Alternatively, you could invert the image using the bitwise_not function of OpenCV:

imagem = cv2.bitwise_not(imagem)

I liked this example.

Stacking DIVs on top of each other?

All the answers seem pretty old :) I'd prefer CSS grid for a better page layout (absolute divs can be overridden by other divs in the page.)

<div class="container">
  <div class="inner" style="background-color: white;"></div>
  <div class="inner" style="background-color: red;"></div>
  <div class="inner" style="background-color: green;"></div>
  <div class="inner" style="background-color: blue;"></div>
  <div class="inner" style="background-color: purple;"></div>
  <div class="inner no-display" style="background-color: black;"></div>
</div>

<style>
.container {
  width: 300px;
  height: 300px;
  margin: 0 auto;
  background-color: yellow;
  display: grid;
  place-items: center;
  grid-template-areas:
                  "inners";
}

.inner {
  grid-area: inners;
  height: 100px;
  width: 100px;
}

.no-display {
  display: none;
}
</style>

Here's a working link

How can I find a specific element in a List<T>?

You can also use LINQ extensions:

string id = "hello";
MyClass result = list.Where(m => m.GetId() == id).First();

How to align a div inside td element using CSS class

I cannot help you much without a small (possibly reduced) snippit of the problem. If the problem is what I think it is then it's because a div by default takes up 100% width, and as such cannot be aligned.

What you may be after is to align the inline elements inside the div (such as text) with text-align:center; otherwise you may consider setting the div to display:inline-block;

If you do go down the inline-block route then you may have to consider my favorite IE hack.

width:100px;
display:inline-block;
zoom:1; //IE only
*display:inline; //IE only

Happy Coding :)

How to launch an Activity from another Application in Android

Since kotlin is becoming very popular these days, I think it's appropriate to provide a simple solution in Kotlin as well.

    var launchIntent: Intent? = null
    try {
        launchIntent = packageManager.getLaunchIntentForPackage("applicationId")
    } catch (ignored: Exception) {
    }
    if (launchIntent == null) {
        startActivity(Intent(Intent.ACTION_VIEW).setData(Uri.parse("https://play.google.com/store/apps/details?id=" + "applicationId")))
    } else {
        startActivity(launchIntent)
    }

Why I got " cannot be resolved to a type" error?

I had wrong package names:

main.java.hello and main.test.hello rather than com.blabla.hello.

  1. I renamed my src-folder to src/main/java and created another src-folder src/test/java.
  2. I renamed my package within src/main/java to com.blabla.hello
  3. I created another package with the same name in src/test/java.

Use success() or complete() in AJAX call

Well, speaking from quarantine, the complete() in $.ajax is like finally in try catch block.

If you use try catch block in any programming language, it doesn't matter whether you execute a thing successfully or got an error in execution. the finally{} block will always be executed.

Same goes for complete() in $.ajax, whether you get success() response or error() the complete() function always will be called once the execution has been done.

Laravel Controller Subfolder routing

For ** Laravel 5 or Laravel 5.1 LTS both **, if you have multiple Controllers in Admin folder, Route::group will be really helpful for you. For example:

Update: Works with Laravel 5.4

My folder Structure:

Http
----Controllers
    ----Api
          ----V1
                 PostsApiController.php
                 CommentsApiController.php
    PostsController.php

PostAPIController:

<?php namespace App\Http\Controllers\Api\V1;

use App\Http\Requests;
use App\Http\Controllers\Controller;   
use Illuminate\Http\Request;

class PostApiController extends Controller {  
...

In My Route.php, I set namespace group to Api\V1 and overall it looks like:

Route::group(
        [           
            'namespace' => 'Api\V1',
            'prefix' => 'v1',
        ], function(){

            Route::get('posts', ['uses'=>'PostsApiController@index']);
            Route::get('posts/{id}', ['uses'=>'PostssAPIController@show']);

    });

For move details to create sub-folder visit this link.

HTTP response header content disposition for attachments

This has nothing to do with the MIME type, but the Content-Disposition header, which should be something like:

Content-Disposition: attachment; filename=genome.jpeg;

Make sure it is actually correctly passed to the client (not filtered by the server, proxy or something). Also you could try to change the order of writing headers and set them before getting output stream.

Laravel - Session store not set on request

Laravel 5.3+ web middleware group is automatically applied to your routes/web.php file by the RouteServiceProvider.

Unless you modify kernel $middlewareGroups array in an unsupported order, probably you are trying to inject requests as a regular dependency from the constructor.

Use request as

public function show(Request $request){

}

instead of

public function __construct(Request $request){

}

Toolbar navigation icon never set

Use setNavigationIcon to change it. don't forget create ActionBarDrawerToggle first!

sample code work for me:

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);


    drawer = (DrawerLayout)findViewById(R.id.drawer_layout);

    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);

    toggle.syncState();

    toolbar.setNavigationIcon(R.drawable.ic_menu);

How to master AngularJS?

The #angularjs IRC channel on freenode.net is a great way to get real-time responses.

Advice for getting help via IRC:

  1. Have a relatively specific question to ask.
  2. If possible, demonstrate your issue using Plunker or JSFiddle.
  3. Pick "prime time" hours to ask (Mid-afternoon to evening, EST works well for me.)
  4. Don't pop in, ask a question, and leave 2 minutes later when someone doesn't answer immediately. Most of us only check IRC periodically.

How to make input type= file Should accept only pdf and xls

If you want the file upload control to Limit the types of files user can upload on a button click then this is the way..

<script type="text/JavaScript">
<!-- Begin
function TestFileType( fileName, fileTypes ) {
if (!fileName) return;

dots = fileName.split(".")
//get the part AFTER the LAST period.
fileType = "." + dots[dots.length-1];

return (fileTypes.join(".").indexOf(fileType) != -1) ?
alert('That file is OK!') : 
alert("Please only upload files that end in types: \n\n" + (fileTypes.join(" .")) + "\n\nPlease select a new file and try again.");
}
// -->
</script>

You can then call the function from an event like the onClick of the above button, which looks like:

onClick="TestFileType(this.form.uploadfile.value, ['gif', 'jpg', 'png', 'jpeg']);"

You can change this to: PDF and XLS

You can see it implemented over here: Demo

How to add bootstrap in angular 6 project?

For Angular Version 11+

Configuration

The styles and scripts options in your angular.json configuration now allow to reference a package directly:

before: "styles": ["../node_modules/bootstrap/dist/css/bootstrap.css"]
after: "styles": ["bootstrap/dist/css/bootstrap.css"]

          "builder": "@angular-devkit/build-angular:browser",
          "options": {
            "outputPath": "dist/ng6",
            "index": "src/index.html",
            "main": "src/main.ts",
            "polyfills": "src/polyfills.ts",
            "tsConfig": "src/tsconfig.app.json",
            "assets": [
              "src/favicon.ico",
              "src/assets"
            ],
            "styles": [
              "src/styles.css","bootstrap/dist/css/bootstrap.min.css"

            ],
            "scripts": [
                       "jquery/dist/jquery.min.js",
                       "bootstrap/dist/js/bootstrap.min.js"
                       ]
          },

Angular Version 10 and below

You are using Angular v6 not 2

Angular v6 Onwards

CLI projects in angular 6 onwards will be using angular.json instead of .angular-cli.json for build and project configuration.

Each CLI workspace has projects, each project has targets, and each target can have configurations.Docs

. {
  "projects": {
    "my-project-name": {
      "projectType": "application",
      "architect": {
        "build": {
          "configurations": {
            "production": {},
            "demo": {},
            "staging": {},
          }
        },
        "serve": {},
        "extract-i18n": {},
        "test": {},
      }
    },
    "my-project-name-e2e": {}
  },
}

OPTION-1
execute npm install bootstrap@4 jquery --save
The JavaScript parts of Bootstrap are dependent on jQuery. So you need the jQuery JavaScript library file too.

In your angular.json add the file paths to the styles and scripts array in under build target
NOTE: Before v6 the Angular CLI project configuration was stored in <PATH_TO_PROJECT>/.angular-cli.json. As of v6 the location of the file changed to angular.json. Since there is no longer a leading dot, the file is no longer hidden by default and is on the same level.
which also means that file paths in angular.json should not contain leading dots and slash

i.e you can provide an absolute path instead of a relative path

In .angular-cli.json file Path was "../node_modules/"
In angular.json it is "node_modules/"

 "build": {
          "builder": "@angular-devkit/build-angular:browser",
          "options": {
            "outputPath": "dist/ng6",
            "index": "src/index.html",
            "main": "src/main.ts",
            "polyfills": "src/polyfills.ts",
            "tsConfig": "src/tsconfig.app.json",
            "assets": [
              "src/favicon.ico",
              "src/assets"
            ],
            "styles": [
              "src/styles.css","node_modules/bootstrap/dist/css/bootstrap.min.css"
               
            ],
            "scripts": ["node_modules/jquery/dist/jquery.min.js",
                       "node_modules/bootstrap/dist/js/bootstrap.min.js"]
          },

OPTION 2
Add files from CDN (Content Delivery Network) to your project CDN LINK

Open file src/index.html and insert

the <link> element at the end of the head section to include the Bootstrap CSS file
a <script> element to include jQuery at the bottom of the body section
a <script> element to include Popper.js at the bottom of the body section
a <script> element to include the Bootstrap JavaScript file at the bottom of the body section

  <!doctype html>
    <html>
    <head>
      <meta charset="utf-8">
      <title>Angular</title>
      <base href="/">
      <meta name="viewport" content="width=device-width, initial-scale=1">
      <link rel="icon" type="image/x-icon" href="favicon.ico">
      <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
    </head>
    <body>
      <app-root>Loading...</app-root>
      <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
    </body>
    </html>

OPTION 3
Execute npm install bootstrap
In src/styles.css add the following line:

@import "~bootstrap/dist/css/bootstrap.css";

OPTION-4
ng-bootstrap It contains a set of native Angular directives based on Bootstrap’s markup and CSS. As a result, it's not dependent on jQuery or Bootstrap’s JavaScript

npm install --save @ng-bootstrap/ng-bootstrap

After Installation import it in your root module and register it in @NgModule imports` array

import {NgbModule} from '@ng-bootstrap/ng-bootstrap';
@NgModule({
  declarations: [AppComponent, ...],
  imports: [NgbModule.forRoot(), ...],
  bootstrap: [AppComponent]
})

NOTE
ng-bootstrap requires Bootstrap's 4 css to be added in your project. you need to Install it explicitly via:
npm install bootstrap@4 --save In your angular.json add the file paths to the styles array in under build target

   "styles": [
      "src/styles.css",
      "node_modules/bootstrap/dist/css/bootstrap.min.css"
   ],

P.S Do Restart Your server

`ng serve || npm start`

Getting java.net.SocketTimeoutException: Connection timed out in android

I was facing this problem and the solution was to restart my modem (router). I could get connection for my app to internet after that.

I think the library I am using is not managing connections properly because it happeend just few times.

HTML select drop-down with an input field

You can use input text with "list" attribute, which refers to the datalist of values.

_x000D_
_x000D_
<input type="text" name="city" list="cityname">_x000D_
    <datalist id="cityname">_x000D_
      <option value="Boston">_x000D_
      <option value="Cambridge">_x000D_
    </datalist>
_x000D_
_x000D_
_x000D_

This creates a free text input field that also has a drop-down to select predefined choices. Attribution for example and more information: https://www.w3.org/wiki/HTML/Elements/datalist

.NET Out Of Memory Exception - Used 1.3GB but have 16GB installed

If you have 32-bit Windows, this method is not working without following settings.

  1. Run prompt cmd.exe (important : Run As Administrator)
  2. type bcdedit.exe and run
  3. Look at the "increaseuserva" params and there is no then write following statement
  4. bcdedit /set increaseuserva 3072
  5. and again step 2 and check params

We added this settings and this block started.

if exist "$(DevEnvDir)..\tools\vsvars32.bat" (
   call "$(DevEnvDir)..\tools\vsvars32.bat"
   editbin /largeaddressaware "$(TargetPath)"
)

More info - command increaseuserva: https://docs.microsoft.com/en-us/windows-hardware/drivers/devtest/bcdedit--set

Set scroll position

... Or just replace body by documentElement:

document.documentElement.scrollTop = 0;

how to create inline style with :before and :after

If you really need it inline, for example because you are loading some user-defined colors dynamically, you can always add a <style> element right before your content.

<style>#project-slide-1:before { color: #ff0000; }</style>
<div id="project-slide-1" class="project-slide"> ... </div>

Example use case with PHP and some (wordpress inspired) dummy functions:

<style>#project-slide-<?php the_ID() ?>:before { color: <?php the_field('color') ?>; }</style>
<div id="project-slide-<?php the_ID() ?>" class="project-slide"> ... </div>

Since HTML 5.2 it is valid to place style elements inside the body, although it is still recommend to place style elements in the head.

Reference: https://www.w3.org/TR/html52/document-metadata.html#the-style-element

How to add a hook to the application context initialization event?

Since Spring 4.2 you can use @EventListener (documentation)

@Component
class MyClassWithEventListeners {

    @EventListener({ContextRefreshedEvent.class})
    void contextRefreshedEvent() {
        System.out.println("a context refreshed event happened");
    }
}

How can I convert byte size into a human-readable format in Java?

Kotlin Version via Extension Property

If you are using kotlin, it's pretty easy to format file size by these extension properties. It is loop-free and completely based on pure math.


HumanizeUtils.kt

import java.io.File
import kotlin.math.log2
import kotlin.math.pow

/**
 * @author aminography
 */

val File.formatSize: String
    get() = length().formatAsFileSize

val Int.formatAsFileSize: String
    get() = toLong().formatAsFileSize

val Long.formatAsFileSize: String
    get() = log2(if (this != 0L) toDouble() else 1.0).toInt().div(10).let {
        val precision = when (it) {
            0 -> 0; 1 -> 1; else -> 2
        }
        val prefix = arrayOf("", "K", "M", "G", "T", "P", "E", "Z", "Y")
        String.format("%.${precision}f ${prefix[it]}B", toDouble() / 2.0.pow(it * 10.0))
    }

Usage:

println("0:          " + 0.formatAsFileSize)
println("170:        " + 170.formatAsFileSize)
println("14356:      " + 14356.formatAsFileSize)
println("968542985:  " + 968542985.formatAsFileSize)
println("8729842496: " + 8729842496.formatAsFileSize)

println("file: " + file.formatSize)

Result:

0:          0 B
170:        170 B
14356:      14.0 KB
968542985:  923.67 MB
8729842496: 8.13 GB

file: 6.15 MB

How to Calculate Jump Target Address and Branch Target Address?

For small functions like this you could just count by hand how many hops it is to the target, from the instruction under the branch instruction. If it branches backwards make that hop number negative. if that number doesn't require all 16 bits, then for every number to the left of the most significant of your hop number, make them 1's, if the hop number is positive make them all 0's Since most branches are close to they're targets, this saves you a lot of extra arithmetic for most cases.

  • chris

Android, getting resource ID from string?

You can use this function to get resource ID.

public static int getResourceId(String pVariableName, String pResourcename, String pPackageName) 
{
    try {
        return getResources().getIdentifier(pVariableName, pResourcename, pPackageName);
    } catch (Exception e) {
        e.printStackTrace();
        return -1;
    } 
}

So if you want to get for drawable call function like this

getResourceId("myIcon", "drawable", getPackageName());

and for string you can call it like this

getResourceId("myAppName", "string", getPackageName());

Read this

Find (and kill) process locking port 3000 on Mac

lsof -P | grep ':3000' | awk '{print $2}'

This will give you just the pid, tested on MacOS.

Equivalent VB keyword for 'break'

In both Visual Basic 6.0 and VB.NET you would use:

  • Exit For to break from For loop
  • Wend to break from While loop
  • Exit Do to break from Do loop

depending on the loop type. See Exit Statements for more details.

How to write JUnit test with Spring Autowire?

Make sure you have imported the correct package. If I remeber correctly there are two different packages for Autowiring. Should be :org.springframework.beans.factory.annotation.Autowired;

Also this looks wierd to me :

@ContextConfiguration("classpath*:conf/components.xml")

Here is an example that works fine for me :

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = { "/applicationContext_mock.xml" })
public class OwnerIntegrationTest {

    @Autowired
    OwnerService ownerService;

    @Before
    public void setup() {

        ownerService.cleanList();

    }

    @Test
    public void testOwners() {

        Owner owner = new Owner("Bengt", "Karlsson", "Ankavägen 3");
        owner = ownerService.createOwner(owner);
        assertEquals("Check firstName : ", "Bengt", owner.getFirstName());
        assertTrue("Check that Id exist: ", owner.getId() > 0);

        owner.setLastName("Larsson");
        ownerService.updateOwner(owner);
        owner = ownerService.getOwner(owner.getId());
        assertEquals("Name is changed", "Larsson", owner.getLastName());

    }

if statement in ng-click

We can add ng-click event conditionally without using disabled class.

HTML:

  <input ng-click="profileForm.$valid && updateMyProfile()" name="submit" id="submit" value="Save" class="submit" type="submit">

RecyclerView - Get view at particular position

You can make ArrayList of ViewHolder :

 ArrayList<MyViewHolder> myViewHolders = new ArrayList<>();
 ArrayList<MyViewHolder> myViewHolders2 = new ArrayList<>();

and, all store ViewHolder(s) in the list like :

 @Override
    public void onBindViewHolder(@NonNull final MyViewHolder holder, final int position) {
        final String str = arrayList.get(position);

        myViewHolders.add(position,holder);
}

and add/remove other ViewHolder in the ArrayList as per your requirement.

java.lang.OutOfMemoryError: Java heap space in Maven

I have solved this problem on my side by 2 ways:

  1. Adding this configuration in pom.xml

    <configuration><argLine>-Xmx1024m</argLine></configuration>
    
  2. Switch to used JDK 1.7 instead of 1.6

How to add a button dynamically using jquery

To add dynamic button on the fly;

<!DOCTYPE html>
<html>
<head>
     <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
     <script type="text/javascript">
        function newButtonClickListener() {
                alert("Hello World");
        }
         function test() {
            var r = $('<input/>').attr({
                         type: "button",
                         id: "field",
                         value: "New Button",
                         onclick: "newButtonClickListener()"
                    });

            $("body").append(r);
         }
     </script>
</head>
<body>
     <button onclick="test()">Insert after</button><br/> 
</body>
</html>

Demo link

SQL Server 2005 How Create a Unique Constraint?

ALTER TABLE dbo.<tablename> ADD CONSTRAINT
            <namingconventionconstraint> UNIQUE NONCLUSTERED
    (
                <columnname>
    ) ON [PRIMARY]

Maximum concurrent connections to MySQL

As per the MySQL docs: http://dev.mysql.com/doc/refman/5.0/en/server-system-variables.html#sysvar_max_user_connections

 maximum range: 4,294,967,295  (e.g. 2**32 - 1)

You'd probably run out of memory, file handles, and network sockets, on your server long before you got anywhere close to that limit.

What is thread Safe in java?

Thread safe simply means that it may be used from multiple threads at the same time without causing problems. This can mean that access to any resources are synchronized, or whatever.

VBA Object doesn't support this property or method

Object doesn't support this property or method.

Think of it like if anything after the dot is called on an object. It's like a chain.

An object is a class instance. A class instance supports some properties defined in that class type definition. It exposes whatever intelli-sense in VBE tells you (there are some hidden members but it's not related to this). So after each dot . you get intelli-sense (that white dropdown) trying to help you pick the correct action.

(you can start either way - front to back or back to front, once you understand how this works you'll be able to identify where the problem occurs)

Type this much anywhere in your code area

Dim a As Worksheets
a.

you get help from VBE, it's a little dropdown called Intelli-sense

enter image description here

It lists all available actions that particular object exposes to any user. You can't see the .Selection member of the Worksheets() class. That's what the error tells you exactly.

Object doesn't support this property or method.

If you look at the example on MSDN

Worksheets("GRA").Activate
iAreaCount = Selection.Areas.Count

It activates the sheet first then calls the Selection... it's not connected together because Selection is not a member of Worksheets() class. Simply, you can't prefix the Selection

What about

Sub DisplayColumnCount()
    Dim iAreaCount As Integer
    Dim i As Integer

    Worksheets("GRA").Activate
    iAreaCount = Selection.Areas.Count

    If iAreaCount <= 1 Then
        MsgBox "The selection contains " & Selection.Columns.Count & " columns."
    Else
        For i = 1 To iAreaCount
        MsgBox "Area " & i & " of the selection contains " & _
        Selection.Areas(i).Columns.Count & " columns."
        Next i
    End If
End Sub

from HERE

MySQL: Insert datetime into other datetime field

Try

    UPDATE products SET former_date=20111218131717 WHERE id=1

Alternatively, you might want to look at using the STR_TO_DATE (see STR_TO_DATE(str,format)) function.

Link to download apache http server for 64bit windows.

Check out the link given it has Apache HTTP Server 2.4.2 x86 and x64 Windows Installers http://www.anindya.com/apache-http-server-2-4-2-x86-and-x64-windows-installers/

Do I commit the package-lock.json file created by npm 5?

Disable package-lock.json globally

type the following in your terminal:

npm config set package-lock false

this really work for me like magic

How To Execute SSH Commands Via PHP

For those using the Symfony framework, the phpseclib can also be used to connect via SSH. It can be installed using composer:

composer require phpseclib/phpseclib

Next, simply use it as follows:

use phpseclib\Net\SSH2;

// Within a controller for example:
$ssh = new SSH2('hostname or ip');
if (!$ssh->login('username', 'password')) {
    // Login failed, do something
}

$return_value = $ssh->exec('command');

How to send PUT, DELETE HTTP request in HttpURLConnection?

there is a simple way for delete and put request, you can simply do it by adding a "_method" parameter to your post request and write "PUT" or "DELETE" for its value!

Virtualbox "port forward" from Guest to Host

Network communication Host -> Guest

Connect to the Guest and find out the ip address:

ifconfig 

example of result (ip address is 10.0.2.15):

eth0      Link encap:Ethernet  HWaddr 08:00:27:AE:36:99
          inet addr:10.0.2.15  Bcast:10.0.2.255  Mask:255.255.255.0

Go to Vbox instance window -> Menu -> Network adapters:

  • adapter should be NAT
  • click on "port forwarding"
  • insert new record (+ icon)
    • for host ip enter 127.0.0.1, and for guest ip address you got from prev. step (in my case it is 10.0.2.15)
    • in your case port is 8000 - put it on both, but you can change host port if you prefer

Go to host system and try it in browser:

http://127.0.0.1:8000

or your network ip address (find out on the host machine by running: ipconfig).

Network communication Guest -> Host

In this case port forwarding is not needed, the communication goes over the LAN back to the host.

On the host machine - find out your netw ip address:

ipconfig

example of result:

IP Address. . . . . . . . . . . . : 192.168.5.1

On the guest machine you can communicate directly with the host, e.g. check it with ping:

# ping 192.168.5.1
PING 192.168.5.1 (192.168.5.1) 56(84) bytes of data.
64 bytes from 192.168.5.1: icmp_seq=1 ttl=128 time=2.30 ms
...

Firewall issues?

@Stranger suggested that in some cases it would be necessary to open used port (8000 or whichever is used) in firewall like this (example for ufw firewall, I haven't tested):

sudo ufw allow 8000 

How can I debug javascript on Android?

Try:

  1. open the page that you want to debug
  2. while on that page, in the address bar of a stock Android browser, type:

    about:debug 
    

    (Note nothing happens, but some new options have been enabled.)

Works on the devices I have tried. Read more on Android browser's about:debug, what do those settings do?

Edit: What also helps to retrieve more information like line number is to add this code to your script:

window.onerror = function (message, url, lineNo){
    console.log('Error: ' + message + '\n' + 'Line Number: ' + lineNo);
    return true;
}

How to display special characters in PHP

So I try htmlspecialchars() or htmlentities() which outputs <p>Résumé<p> and the browser renders <p>Résumé<p>.

If you've got it working where it displays Résumé with <p></p> tags around it, then just don't convert the paragraph, only your string. Then the paragraph will be rendered as HTML and your string will be displayed within.

How to redirect to another page using PHP

The simplest approach is that your script validates the form-posted login data "on top" of the script before any output.

If the login is valid you'll redirect using the "header" function.

Even if you use "ob_start()" it sometimes happens that you miss a single whitespace which results in output. But you will see a statement in your error logs then.

<?php
ob_start();
if (FORMPOST) {
    if (POSTED_DATA_VALID) {
        header("Location: https://www.yoursite.com/profile/");
        ob_end_flush();
        exit;
    }
}
/** YOUR LOGINBOX OUTPUT, ERROR MESSAGES ... **/
ob_end_flush();
?>

How to find the Windows version from the PowerShell command line

[solved]

#copy all the code below:
#save file as .ps1 run and see the magic

 Get-WmiObject -Class Win32_OperatingSystem | ForEach-Object -MemberName Caption
 (Get-CimInstance Win32_OperatingSystem).version


#-------------comment-------------#
#-----finding windows version-----#

$version= (Get-CimInstance Win32_OperatingSystem).version
$length= $version.Length
$index= $version.IndexOf(".")
[int]$windows= $version.Remove($index,$length-2)  
$windows
#-----------end------------------#
#-----------comment-----------------#

Implementing two interfaces in a class with same method. Which interface method is overridden?

Well if they are both the same it doesn't matter. It implements both of them with a single concrete method per interface method.

Shortcut for echo "<pre>";print_r($myarray);echo "</pre>";

If you are using XDebug simply use

var_dump($variable);

This will dump the variable like print_r does - but nicely formatted and in a <pre>.

(If you don't use XDebug then var_dump will be as badly formated as print_r without <pre>.)

scp copy directory to another server with private key auth

The command looks quite fine. Could you try to run -v (verbose mode) and then we can figure out what it is wrong on the authentication?

Also as mention in the other answer, maybe could be this issue - that you need to convert the keys (answered already here): How to convert SSH keypairs generated using PuttyGen(Windows) into key-pairs used by ssh-agent and KeyChain(Linux) OR http://winscp.net/eng/docs/ui_puttygen (depending what you need)

PHP - Move a file into a different folder on the server

If you want to move the file in new path with keep original file name. use this:

$source_file = 'foo/image.jpg';
$destination_path = 'bar/';
rename($source_file, $destination_path . pathinfo($source_file, PATHINFO_BASENAME));

Where can I find MySQL logs in phpMyAdmin?

I had the same problem of @rutherford, today the new phpMyAdmin's 3.4.11.1 GUI is different, so I figure out it's better if someone improves the answers with updated info.

Full mysql logs can be found in:

"Status"->"Binary Log"

This is the answer, doesn't matter if you're using MAMP, XAMPP, LAMP, etc.

Setting the value of checkbox to true or false with jQuery

var checkbox = $( "#checkbox" );
checkbox.val( checkbox[0].checked ? "true" : "false" );

This will set the value of the checkbox to "true" or "false" (value property is a string), depending whether it's unchecked or checked.

Works in jQuery >= 1.0

How to edit a text file in my terminal

If you are still inside the vi editor, you might be in a different mode from the one you want. Hit ESC a couple of times (until it rings or flashes) and then "i" to enter INSERT mode or "a" to enter APPEND mode (they are the same, just start before or after current character).

If you are back at the command prompt, make sure you can locate the file, then navigate to that directory and perform the mentioned "vi helloWorld.txt". Once you are in the editor, you'll need to check the vi reference to know how to perform the editions you want (you may want to google "vi reference" or "vi cheat sheet").

Once the edition is done, hit ESC again, then type :wq to save your work or :q! to quit without saving.

For quick reference, here you have a text-based cheat sheet.

Docker for Windows error: "Hardware assisted virtualization and data execution protection must be enabled in the BIOS"

If the problem persists probably Hyper-V on your system is corrupted, so

Go in Control Panel -> [Programs] -> [Windows Features] and completely uncheck all Hyper-V related components. Restart the system.

Enable Hyper-V again. Restart.

JavaFX "Location is required." even though it is in the same package

The root directory for the loader is in the 'resources' folder for a maven project. So if you have src/main/java then the fxml file path should start from: src/main/resources

https://maven.apache.org/guides/introduction/introduction-to-the-standard-directory-layout.html

How to insert close button in popover for Bootstrap

Here's a "cheat" solution:

Follow the usual directions for a dismissable popup.

Then slap an 'X' in the box with CSS.

CSS:

.popover-header::after {
    content: "X";
    position: absolute;
    top: 1ex;
    right: 1ex;
}

JQUERY:

$('.popover-dismiss').popover({
    trigger: 'focus'
});

HTML:

<a data-toggle="popover" data-trigger="focus" tabindex="0"  title="Native Hawaiian or Other Pacific Islander" data-content="A person having origins in any of the original peoples of Hawaii, Guam, Samoa, or other Pacific Islands.">?</a>

Technically speaking that makes it dismissable if someone clicks something other than the "X" but that's not a problem in my scenario at least.

DateTime to javascript date

I know this is a little late, but here's the solution I had to come up with for handling dates when you want to be timezone independent. Essentially it involves converting everything to UTC.

From Javascript to Server:

Send out dates as epoch values with the timezone offset removed.

var d = new Date(2015,0,1) // Jan 1, 2015
// Ajax Request to server ...
$.ajax({
  url: '/target',
  params: { date: d.getTime() - (d.getTimezoneOffset() * 60 * 1000) }
});

The server then recieves 1420070400000 as the date epoch.

On the Server side, convert that epoch value to a datetime object:

DateTime d = new DateTime(1970, 1, 1, 0, 0, 0).AddMilliseconds(epoch);

At this point the date is just the date/time provided by the user as they provided it. Effectively it is UTC.

Going the other way:

When the server pulls data from the database, presumably in UTC, get the difference as an epoch (making sure that both date objects are either local or UTC):

long ms = (long)utcDate.Subtract(new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).TotalMilliseconds;

or

long ms = (long)localDate.Subtract(new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Local)).TotalMilliseconds;

When javascript receives this value, create a new date object. However, this date object is going to be assumed local time, so you need to offset it by the current timezone:

var epochValue = 1420070400000 // value pulled from server.
var utcDateVal = new Date(epochValue);
var actualDate = new Date(utcDateVal.getTime() + (utcDateVal.getTimezoneOffset() * 60 * 1000))

console.log(utcDateVal); // Wed Dec 31 2014 19:00:00 GMT-0500 (Eastern Standard Time)
console.log(actualDate); // Thu Jan 01 2015 00:00:00 GMT-0500 (Eastern Standard Time)

As far as I know, this should work for any time zone where you need to display dates that are timezone independent.

How set maximum date in datepicker dialog in android?

Here's a Kotlin extension function:

fun EditText.transformIntoDatePicker(context: Context, format: String, maxDate: Date? = null) {
    isFocusableInTouchMode = false
    isClickable = true
    isFocusable = false

    val myCalendar = Calendar.getInstance()
    val datePickerOnDataSetListener =
        DatePickerDialog.OnDateSetListener { _, year, monthOfYear, dayOfMonth ->
            myCalendar.set(Calendar.YEAR, year)
            myCalendar.set(Calendar.MONTH, monthOfYear)
            myCalendar.set(Calendar.DAY_OF_MONTH, dayOfMonth)
            val sdf = SimpleDateFormat(format, Locale.UK)
            setText(sdf.format(myCalendar.time))
        }

    setOnClickListener {
        DatePickerDialog(
            context, datePickerOnDataSetListener, myCalendar
                .get(Calendar.YEAR), myCalendar.get(Calendar.MONTH),
            myCalendar.get(Calendar.DAY_OF_MONTH)
        ).run {
            maxDate?.time?.also { datePicker.maxDate = it }
            show()
        }
    }
}

Usage:

In Activity:

editText.transformIntoDatePicker(this, "MM/dd/yyyy")
editText.transformIntoDatePicker(this, "MM/dd/yyyy", Date())

In Fragments:

editText.transformIntoDatePicker(requireContext(), "MM/dd/yyyy")
editText.transformIntoDatePicker(requireContext(), "MM/dd/yyyy", Date())

How to make a JSONP request from Javascript without JQuery?

the way I use jsonp like below:

function jsonp(uri) {
    return new Promise(function(resolve, reject) {
        var id = '_' + Math.round(10000 * Math.random());
        var callbackName = 'jsonp_callback_' + id;
        window[callbackName] = function(data) {
            delete window[callbackName];
            var ele = document.getElementById(id);
            ele.parentNode.removeChild(ele);
            resolve(data);
        }

        var src = uri + '&callback=' + callbackName;
        var script = document.createElement('script');
        script.src = src;
        script.id = id;
        script.addEventListener('error', reject);
        (document.getElementsByTagName('head')[0] || document.body || document.documentElement).appendChild(script)
    });
}

then use 'jsonp' method like this:

jsonp('http://xxx/cors').then(function(data){
    console.log(data);
});

reference:

JavaScript XMLHttpRequest using JsonP

http://www.w3ctech.com/topic/721 (talk about the way of use Promise)

Why use a READ UNCOMMITTED isolation level?

This will give you dirty reads, and show you transactions that's not committed yet. That is the most obvious answer. I don't think its a good idea to use this just to speed up your reads. There is other ways of doing that if you use a good database design.

Its also interesting to note whats not happening. READ UNCOMMITTED does not only ignore other table locks. It's also not causing any locks in its own.

Consider you are generating a large report, or you are migrating data out of your database using a large and possibly complex SELECT statement. This will cause a shared lock that's may be escalated to a shared table lock for the duration of your transaction. Other transactions may read from the table, but updates are impossible. This may be a bad idea if its a production database since the production may stop completely.

If you are using READ UNCOMMITTED you will not set a shared lock on the table. You may get the result from some new transactions or you may not depending where it the table the data were inserted and how long your SELECT transaction have read. You may also get the same data twice if for example a page split occurs (the data will be copied to another location in the data file).

So, if its very important for you that data can be inserted while doing your SELECT, READ UNCOMMITTED may make sense. You have to consider that your report may contain some errors, but if its based on millions of rows and only a few of them are updated while selecting the result this may be "good enough". Your transaction may also fail all together since the uniqueness of a row may not be guaranteed.

A better way altogether may be to use SNAPSHOT ISOLATION LEVEL but your applications may need some adjustments to use this. One example of this is if your application takes an exclusive lock on a row to prevent others from reading it and go into edit mode in the UI. SNAPSHOT ISOLATION LEVEL does also come with a considerable performance penalty (especially on disk). But you may overcome that by throwing hardware on the problem. :)

You may also consider restoring a backup of the database to use for reporting or loading data into a data warehouse.

Rollback to last git commit

An easy foolproof way to UNDO local file changes since the last commit is to place them in a new branch:

git branch changes
git checkout changes
git add .
git commit

This leaves the changes in the new branch. Return to the original branch to find it back to the last commit:

git checkout master

The new branch is a good place to practice different ways to revert changes without risk of messing up the original branch.

How to install Hibernate Tools in Eclipse?

Once you have copied the plugins and features folder to eclipse (eg. c:\program files\eclipse (or whereever you installed it). You will see a features and plugins folder there already) you can check if hibernate has installed by going to Help > Software updates > installed software. If hibernate is not listed close eclipse and launch it again via a command window with this command "eclipse -clean".

Critical t values in R

The code you posted gives the critical value for a one-sided test (Hence the answer to you question is simply:

abs(qt(0.25, 40)) # 75% confidence, 1 sided (same as qt(0.75, 40))
abs(qt(0.01, 40)) # 99% confidence, 1 sided (same as qt(0.99, 40))

Note that the t-distribution is symmetric. For a 2-sided test (say with 99% confidence) you can use the critical value

abs(qt(0.01/2, 40)) # 99% confidence, 2 sided

Solution to INSTALL_FAILED_INSUFFICIENT_STORAGE error on Android

Workaround:

Compile as 2.1 without android:installLocation="preferExternal".

OK?

Compile as 2.2 including android:installLocation="preferExternal".

This will still install on SDK version less than 8 (the XML tag is ignored).

How to update core-js to core-js@3 dependency?

You update core-js with the following command:

npm install --save core-js@^3

If you read the React Docs you will find that the command is derived from when you need to upgrade React itself.

How to remove youtube branding after embedding video in web page?

It turns out this is either a poorly documented, intentionally misleading, or undocumented interaction between the "controls" param and the "modestbranding" param. There is no way to remove YouTube's logo from an embedded YouTube video, at least while the video controls are exposed. All you get to do is choose how and when you want the logo to appear. Here are the details:

If controls = 1 and modestbranding = 1, then the YouTube logo is bigger, is on the video still image as a grayscale watermark in the lower right, and shows when the play controls are exposed as a big gray scale watermark in the lower right. example: <iframe width="560" height="315" src="https://www.youtube.com/embed/Z6ytvzNlmRo?rel=0&amp;controls=1&amp&amp;showinfo=0&amp;modestbranding=1" frameborder="0"></iframe>

If controls = 1 and modestbranding = 0 (our change here), then the YouTube logo is smaller, is not on the video still image as a grayscale watermark in the lower right, and shows only when the controls are exposed as a white icon in the lower right. example: <iframe width="560" height="315" src="https://www.youtube.com/embed/Z6ytvzNlmRo?rel=0&amp;controls=1&amp&amp;showinfo=0&amp;modestbranding=0" frameborder="0"></iframe>

If controls = 0, then the modestbranding param is ignored and the YouTube logo is bigger, is on the video still image as a grayscale watermark in the lower right, the watermark appears on hover of a playing video, and the watermark appears in the lower right of any paused video. example: <iframe width="560" height="315" src="https://www.youtube.com/embed/Z6ytvzNlmRo?rel=0&amp;controls=0&amp&amp;showinfo=0&amp;modestbranding=1" frameborder="0"></iframe>

MongoDb query condition on comparing 2 fields

If your query consists only of the $where operator, you can pass in just the JavaScript expression:

db.T.find("this.Grade1 > this.Grade2");

For greater performance, run an aggregate operation that has a $redact pipeline to filter the documents which satisfy the given condition.

The $redact pipeline incorporates the functionality of $project and $match to implement field level redaction where it will return all documents matching the condition using $$KEEP and removes from the pipeline results those that don't match using the $$PRUNE variable.


Running the following aggregate operation filter the documents more efficiently than using $where for large collections as this uses a single pipeline and native MongoDB operators, rather than JavaScript evaluations with $where, which can slow down the query:

db.T.aggregate([
    {
        "$redact": {
            "$cond": [
                { "$gt": [ "$Grade1", "$Grade2" ] },
                "$$KEEP",
                "$$PRUNE"
            ]
        }
    }
])

which is a more simplified version of incorporating the two pipelines $project and $match:

db.T.aggregate([
    {
        "$project": {
            "isGrade1Greater": { "$cmp": [ "$Grade1", "$Grade2" ] },
            "Grade1": 1,
            "Grade2": 1,
            "OtherFields": 1,
            ...
        }
    },
    { "$match": { "isGrade1Greater": 1 } }
])

With MongoDB 3.4 and newer:

db.T.aggregate([
    {
        "$addFields": {
            "isGrade1Greater": { "$cmp": [ "$Grade1", "$Grade2" ] }
        }
    },
    { "$match": { "isGrade1Greater": 1 } }
])

JavaScript get window X/Y position for scroll

function FastScrollUp()
{
     window.scroll(0,0)
};

function FastScrollDown()
{
     $i = document.documentElement.scrollHeight ; 
     window.scroll(0,$i)
};
 var step = 20;
 var h,t;
 var y = 0;
function SmoothScrollUp()
{
     h = document.documentElement.scrollHeight;
     y += step;
     window.scrollBy(0, -step)
     if(y >= h )
       {clearTimeout(t); y = 0; return;}
     t = setTimeout(function(){SmoothScrollUp()},20);

};


function SmoothScrollDown()
{
     h = document.documentElement.scrollHeight;
     y += step;
     window.scrollBy(0, step)
     if(y >= h )
       {clearTimeout(t); y = 0; return;}
     t = setTimeout(function(){SmoothScrollDown()},20);

}

How to use querySelectorAll only for elements that have a specific attribute set?

You can use querySelectorAll() like this:

var test = document.querySelectorAll('input[value][type="checkbox"]:not([value=""])');

This translates to:

get all inputs with the attribute "value" and has the attribute "value" that is not blank.

In this demo, it disables the checkbox with a non-blank value.

Get first day of week in PHP?

I found this quite frustrating given that my timezone is Australian and that strtotime() hates UK dates.

If the current day is a Sunday, then strtotime("monday this week") will return the day after.

To overcome this:

Caution: This is only valid for Australian/UK dates

$startOfWeek = (date('l') == 'Monday') ? date('d/m/Y 00:00') : date('d/m/Y', strtotime("last monday 00:00"));
$endOfWeek = (date('l') == 'Sunday') ? date('d/m/Y 23:59:59') : date('d/m/Y', strtotime("sunday 23:59:59"));

How to filter data in dataview

Eg:

Datatable newTable =  new DataTable();

            foreach(string s1 in list)
            {
                if (s1 != string.Empty) {
                    dvProducts.RowFilter = "(CODE like '" + serachText + "*') AND (CODE <> '" + s1 + "')";
                    foreach(DataRow dr in dvProducts.ToTable().Rows)
                    {
                       newTable.ImportRow(dr);
                    }
                }
            }
ListView1.DataSource = newTable;
ListView1.DataBind();

How do you concatenate Lists in C#?

Take a look at my implementation. It's safe from null lists.

 IList<string> all= new List<string>();

 if (letterForm.SecretaryPhone!=null)// first list may be null
     all=all.Concat(letterForm.SecretaryPhone).ToList();

 if (letterForm.EmployeePhone != null)// second list may be null
     all= all.Concat(letterForm.EmployeePhone).ToList(); 

 if (letterForm.DepartmentManagerName != null) // this is not list (its just string variable) so wrap it inside list then concat it 
     all = all.Concat(new []{letterForm.DepartmentManagerPhone}).ToList();

Hide the browse button on a input type=file

Just add negative text intent as so:

input[type=file] {
  text-indent: -120px;
}

before:

enter image description here

after:

enter image description here

How to show Page Loading div until the page has finished loading?

Based on @mehyaa answer, but much shorter:

HTML (right after <body>):

<img id = "loading" src = "loading.gif" alt = "Loading indicator">

CSS:

#loading {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 32px;
  height: 32px;
  /* 1/2 of the height and width of the actual gif */
  margin: -16px 0 0 -16px;
  z-index: 100;
  }

Javascript (jQuery, since I'm already using it):

$(window).load(function() {
  $('#loading').remove();
  });

Variable length (Dynamic) Arrays in Java

Yes: use ArrayList.

In Java, "normal" arrays are fixed-size. You have to give them a size and can't expand them or contract them. To change the size, you have to make a new array and copy the data you want - which is inefficient and a pain for you.

Fortunately, there are all kinds of built-in classes that implement common data structures, and other useful tools too. You'll want to check the Java 6 API for a full list of them.

One caveat: ArrayList can only hold objects (e.g. Integers), not primitives (e.g. ints). In MOST cases, autoboxing/autounboxing will take care of this for you silently, but you could get some weird behavior depending on what you're doing.

How to find if directory exists in Python

As in:

In [3]: os.path.exists('/d/temp')
Out[3]: True

Probably toss in a os.path.isdir(...) to be sure.