Programs & Examples On #Permission denied

This tag refers to a situation in which you are refused access to a particular system, file, database, etc. that is protected. The most common cause of this is improper credentials (i.e. usernames, passwords, etc.)

Permission denied on CopyFile in VBS

for me adding / worked at the end of location of folder. Hence, if you are copying into folder, don't forget to put /

Error: EACCES: permission denied, access '/usr/local/lib/node_modules'

If you are facing this issue on you Mac. Follow these steps

First checking who is owner of this file by using below command

ls -la /usr/local/lib/node_modules

you will find some file like below one of them is below

drwxr-xr-x   3 root    wheel  768 May 29 02:21 node_modules

have you notice that above file is own by root, for make changes inside for you need to change owner ship of path.

you can use check who is current user by this command

id -un (in my case user is yamsol)

and then you can change by calling this command (just replace your user name with ownerName)

sudo chown -R ownerName: /usr/local/lib/node_modules

in my case as you know user is "yamsol" i will call this command in this way

sudo chown -R yamsol: /usr/local/lib/node_modules

thats it.

Node.js EACCES error when listening on most ports

Another approach is to make port redirection:

sudo iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 900 -j REDIRECT --to-port 3000

And run your server on >1024 port:

require('http').createServer().listen(3000);

ps the same could be done for https(443) port by the way.

.bashrc: Permission denied

The .bashrc file is in your user home directory (~/.bashrc or ~vagrant/.bashrc both resolve to the same path), inside the VM's filesystem. This file is invisible on the host machine, so you can't use any Windows editors to edit it directly.

You have two simple choices:

  1. Learn how to use a console-based text editor. My favourite is vi (or vim), which takes 15 minutes to learn the basics and is much quicker for simple edits than anything else.

    vi .bashrc

  2. Copy .bashrc out to /vagrant (which is a shared directory) and edit it using your Windows editors. Make sure not to save it back with any extensions.

    cp .bashrc /vagrant ... edit using your host machine ... cp /vagrant/.bashrc .

I'd recommend getting to know the command-line based editors. Once you're working inside the VM, it's best to stay there as otherwise you might just get confused.

You (the vagrant user) are the owner of your home .bashrc so you do have permissions to edit it.

Once edited, you can execute it by typing source .bashrc I prefer to logout and in again (there may be more than one file executed on login).

Executing a shell script from a PHP script

Without really knowing the complexity of the setup, I like the sudo route. First, you must configure sudo to permit your webserver to sudo run the given command as root. Then, you need to have the script that the webserver shell_exec's(testscript) run the command with sudo.

For A Debian box with Apache and sudo:

  1. Configure sudo:

    • As root, run the following to edit a new/dedicated configuration file for sudo:

      visudo -f /etc/sudoers.d/Webserver
      

      (or whatever you want to call your file in /etc/sudoers.d/)

    • Add the following to the file:

      www-data ALL = (root) NOPASSWD: <executable_file_path>
      

      where <executable_file_path> is the command that you need to be able to run as root with the full path in its name(say /bin/chown for the chown executable). If the executable will be run with the same arguments every time, you can add its arguments right after the executable file's name to further restrict its use.

      For example, say we always want to copy the same file in the /root/ directory, we would write the following:

      www-data ALL = (root) NOPASSWD: /bin/cp /root/test1 /root/test2
      
  2. Modify the script(testscript):

    Edit your script such that sudo appears before the command that requires root privileges(say sudo /bin/chown ... or sudo /bin/cp /root/test1 /root/test2). Make sure that the arguments specified in the sudo configuration file exactly match the arguments used with the executable in this file. So, for our example above, we would have the following in the script:

    sudo /bin/cp /root/test1 /root/test2
    

If you are still getting permission denied, the script file and it's parent directories' permissions may not allow the webserver to execute the script itself. Thus, you need to move the script to a more appropriate directory and/or change the script and parent directory's permissions to allow execution by www-data(user or group), which is beyond the scope of this tutorial.

Keep in mind:

When configuring sudo, the objective is to permit the command in it's most restricted form. For example, instead of permitting the general use of the cp command, you only allow the cp command if the arguments are, say, /root/test1 /root/test2. This means that cp's arguments(and cp's functionality cannot be altered).

C compile error: Id returned 1 exit status

1d returned 1 exit status error

First of all you have to create a project by clicking file new and then project and give project name select the language c or c++ and select empty also. Then your program is under that project... And then give a program name save it.... Ensure that your under some project to compile and run a program...

Permission denied on accessing host directory in Docker

Typically, permissions issues with a host volume mount are because the uid/gid inside the container does not have access to the file according to the uid/gid permissions of the file on the host. However, this specific case is different.

The dot at the end of the permission string, drwxr-xr-x., indicates SELinux is configured. When using a host mount with SELinux, you need to pass an extra option to the end of the volume definition:

  • The z option indicates that the bind mount content is shared among multiple containers.
  • The Z option indicates that the bind mount content is private and unshared.

Your volume mount command would then look like:

sudo docker run -i -v /data1/Downloads:/Downloads:z ubuntu bash

See more about host mounts with SELinux at: https://docs.docker.com/storage/bind-mounts/#configure-the-selinux-label


For others that see this issue with containers running as a different user, you need to ensure the uid/gid of the user inside the container has permissions to the file on the host. On production servers, this is often done by controlling the uid/gid in the image build process to match a uid/gid on the host that has access to the files (or even better, do not use host mounts in production).

A named volume is often preferred to host mounts because it will initialize the volume directory from the image directory, including any file ownership and permissions. This happens when the volume is empty and the container is created with the named volume.

MacOS users now have OSXFS which handles uid/gid's automatically between the Mac host and containers. One place it doesn't help with are files from inside the embedded VM that get mounted into the container, like /var/lib/docker.sock.

For development environments where the host uid/gid may change per developer, my preferred solution is to start the container with an entrypoint running as root, fix the uid/gid of the user inside the container to match the host volume uid/gid, and then use gosu to drop from root to the container user to run the application inside the container. The important script for this is fix-perms in my base image scripts, which can be found at: https://github.com/sudo-bmitch/docker-base

The important bit from the fix-perms script is:

# update the uid
if [ -n "$opt_u" ]; then
  OLD_UID=$(getent passwd "${opt_u}" | cut -f3 -d:)
  NEW_UID=$(stat -c "%u" "$1")
  if [ "$OLD_UID" != "$NEW_UID" ]; then
    echo "Changing UID of $opt_u from $OLD_UID to $NEW_UID"
    usermod -u "$NEW_UID" -o "$opt_u"
    if [ -n "$opt_r" ]; then
      find / -xdev -user "$OLD_UID" -exec chown -h "$opt_u" {} \;
    fi
  fi
fi

That gets the uid of the user inside the container, and the uid of the file, and if they do not match, calls usermod to adjust the uid. Lastly it does a recursive find to fix any files which have not changed uid's. I like this better than running a container with a -u $(id -u):$(id -g) flag because the above entrypoint code doesn't require each developer to run a script to start the container, and any files outside of the volume that are owned by the user will have their permissions corrected.


You can also have docker initialize a host directory from an image by using a named volume that performs a bind mount. This directory must exist in advance, and you need to provide an absolute path to the host directory, unlike host volumes in a compose file which can be relative paths. The directory must also be empty for docker to initialize it. Three different options for defining a named volume to a bind mount look like:

  # create the volume in advance
  $ docker volume create --driver local \
      --opt type=none \
      --opt device=/home/user/test \
      --opt o=bind \
      test_vol

  # create on the fly with --mount
  $ docker run -it --rm \
    --mount type=volume,dst=/container/path,volume-driver=local,volume-opt=type=none,volume-opt=o=bind,volume-opt=device=/home/user/test \
    foo

  # inside a docker-compose file
  ...
  volumes:
    bind-test:
      driver: local
      driver_opts:
        type: none
        o: bind
        device: /home/user/test
  ...

Lastly, if you try using user namespaces, you'll find that host volumes have permission issues because uid/gid's of the containers are shifted. In that scenario, it's probably easiest to avoid host volumes and only use named volumes.

Github permission denied: ssh add agent has no identities

first of all you need to go in your ssh directory
for this type following command in your terminal in mac or whatever you use in window

cd ~/.ssh

now it is in the ssh
here you can find all you ssh key/files related to your all projects. now, type the following command to show you if any ssh key available

ls

this will show you all available ssh, in my case there were two
now, you will need to start an agent to add a ssh in it. For this type following command

eval "$(ssh-agent -s)"

now last but not least you will add a ssh in this agent type following command

ssh-add ~/.ssh/your-ssh

replace

replace your-ssh with your ssh file name which you got a list form second step ls command

Cannot open output file, permission denied

This error usually occurs when the IDE has a problem due to a crash or other failure and it still has a hold on the EXE, preventing the user (yourself) from overwriting / deleting the EXE during a rebuild.

PHP fopen() Error: failed to open stream: Permission denied

[function.fopen]: failed to open stream

If you have access to your php.ini file, try enabling Fopen. Find the respective line and set it to be "on": & if in wp e.g localhost/wordpress/function.fopen in the php.ini :

allow_url_fopen = off
should bee this 
allow_url_fopen = On

And add this line below it:
allow_url_include = off
should bee this 
allow_url_include = on

How do I use sudo to redirect output to a location I don't have permission to write to?

The problem is that the command gets run under sudo, but the redirection gets run under your user. This is done by the shell and there is very little you can do about it.

sudo command > /some/file.log
`-----v-----'`-------v-------'
   command       redirection

The usual ways of bypassing this are:

  • Wrap the commands in a script which you call under sudo.

    If the commands and/or log file changes, you can make the script take these as arguments. For example:

    sudo log_script command /log/file.txt
    
  • Call a shell and pass the command line as a parameter with -c

    This is especially useful for one off compound commands. For example:

    sudo bash -c "{ command1 arg; command2 arg; } > /log/file.txt"
    

PermissionError: [Errno 13] Permission denied

EDIT

I am seeing a bit of activity on my answer so I decided to improve it a bit for those with this issue still

There are basically three main methods of achieving administrator execution privileges on Windows.

  1. Running as admin from cmd.exe
  2. Creating a shortcut to execute the file with elevated privileges
  3. Changing the permissions on the python executable (Not recommended)

1) Running cmd.exe as and admin

Since in Windows there is no sudo command you have to run the terminal (cmd.exe) as an administrator to achieve to level of permissions equivalent to sudo. You can do this two ways:

  1. Manually

    • Find cmd.exe in C:\Windows\system32
    • Right-click on it
    • Select Run as Administrator
    • It will then open the command prompt in the directory C:\Windows\system32
    • Travel to your project directory
    • Run your program
  2. Via key shortcuts

    • Press the windows key (between alt and ctrl usually) + X.
    • A small pop-up list containing various administrator tasks will appear.
    • Select Command Prompt (Admin)
    • Travel to your project directory
    • Run your program

By doing that you are running as Admin so this problem should not persist

2) Creating shortcut with elevated privileges

  1. Create a shortcut for python.exe
  2. Righ-click the shortcut and select Properties
  3. Change the shortcut target into something like "C:\path_to\python.exe" C:\path_to\your_script.py"
  4. Click "advanced" in the property panel of the shortcut, and click the option "run as administrator"

Answer contributed by delphifirst in this question

3) Changing the permissions on the python executable (Not recommended)

This is a possibility but I highly discourage you from doing so.

It just involves finding the python executable and setting it to run as administrator every time. Can and probably will cause problems with things like file creation (they will be admin only) or possibly modules that require NOT being an admin to run.

WinSCP: Permission denied. Error code: 3 Error message from server: Permission denied

You possibly do not have create permissions to the folder. So WinSCP fails to create a temporary file for the transfer.

You have two options:

R multiple conditions in if statement

Read this thread R - boolean operators && and ||.

Basically, the & is vectorized, i.e. it acts on each element of the comparison returning a logical array with the same dimension as the input. && is not, returning a single logical.

Understanding lambda in python and using it to pass multiple arguments

Why do you need to state both x and y before the :?

Because it's a function definition and it needs to know what parameters the function accepts, and in what order. It can't just look at the expression and use the variables names in that, because some of those names you might want to use existing local or global variable values for, and even if it did that, it wouldn't know what order it should expect to get them.

Your error message means that Tk is calling your lambda with one argument, while your lambda is written to accept no arguments. If you don't need the argument, just accept one and don't use it. (Demosthenex has the code, I would have posted it but was beaten to it.)

What's a good way to extend Error in JavaScript?

My 2 cents:

Why another answer?

a) Because accessing the Error.stack property (as in some answers) have a large performance penalty.

b) Because it is only one line.

c) Because the solution at https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error does not seems to preserve stack info.

//MyError class constructor
function MyError(msg){
    this.__proto__.__proto__ = Error.apply(null, arguments);
};

usage example

http://jsfiddle.net/luciotato/xXyeB/

What does it do?

this.__proto__.__proto__ is MyError.prototype.__proto__, so it is setting the __proto__ FOR ALL INSTANCES of MyError to a specific newly created Error. It keeps MyError class properties and methods and also puts the new Error properties (including .stack) in the __proto__ chain.

Obvious problem:

You can not have more than one instance of MyError with useful stack info.

Do not use this solution if you do not fully understand what this.__proto__.__proto__= does.

What is a good practice to check if an environmental variable exists or not?

To be on the safe side use

os.getenv('FOO') or 'bar'

A corner case with the above answers is when the environment variable is set but is empty

For this special case you get

print(os.getenv('FOO', 'bar'))
# prints new line - though you expected `bar`

or

if "FOO" in os.environ:
    print("FOO is here")
# prints FOO is here - however its not

To avoid this just use or

os.getenv('FOO') or 'bar'

Then you get

print(os.getenv('FOO') or 'bar')
# bar

When do we have empty environment variables?

You forgot to set the value in the .env file

# .env
FOO=

or exported as

$ export FOO=

or forgot to set it in settings.py

# settings.py
os.environ['FOO'] = ''

Update: if in doubt, check out these one-liners

>>> import os; os.environ['FOO'] = ''; print(os.getenv('FOO', 'bar'))

$ FOO= python -c "import os; print(os.getenv('FOO', 'bar'))"

How to delete an SVN project from SVN repository

Disposing of a Working Copy

Subversion doesn't track either the state or the existence of working copies on the server, so there's no server overhead to keeping working copies around. Likewise, there's no need to let the server know that you're going to delete a working copy.

If you're likely to use a working copy again, there's nothing wrong with just leaving it on disk until you're ready to use it again, at which point all it takes is an svn update to bring it up to date and ready for use.

However, if you're definitely not going to use a working copy again, you can safely delete the entire thing using whatever directory removal capabilities your operating system offers. We recommend that before you do so you run svn status and review any files listed in its output that are prefixed with a ? to make certain that they're not of importance.

from: http://svnbook.red-bean.com/en/1.7/svn.tour.cleanup.html

Using cURL with a username and password?

Or the same thing but different syntax

curl http://username:[email protected]/test/blah?something=123

How to call multiple functions with @click in vue?

This works for me when you need to open another dialog box by clicking a button inside a dialogue box and also close this one. Pass the values as params with a comma separator.

<v-btn absolute fab small slot="activator" top right color="primary" @click="(addTime = true),(ticketExpenseList = false)"><v-icon>add</v-icon></v-btn>

Executing a batch script on Windows shutdown

Programatically this can be achieved with SCHTASKS:

SCHTASKS /Create /SC ONEVENT /mo "Event[System[(EventID=1074)]]" /EC Security /tn on_shutdown_normal /tr "c:\some.bat" 

SCHTASKS /Create /SC ONEVENT /mo "Event[System[(EventID=6006)]]" /EC Security /tn on_shutdown_6006 /tr "c:\some.bat" 

SCHTASKS /Create /SC ONEVENT /mo "Event[System[(EventID=6008)]]" /EC Security /tn on_shutdown_6008 /tr "c:\some.bat" 

How to create empty data frame with column names specified in R?

Perhaps:

> data.frame(aname=NA, bname=NA)[numeric(0), ]
[1] aname bname
<0 rows> (or 0-length row.names)

unix diff side-to-side results?

If your files have inconsistent use of spaces and tabs, you may find it helpful to include the -t argument to expand the tabs:

diff -ty file1 file2

Retain precision with double in Java

Doubles are approximations of the decimal numbers in your Java source. You're seeing the consequence of the mismatch between the double (which is a binary-coded value) and your source (which is decimal-coded).

Java's producing the closest binary approximation. You can use the java.text.DecimalFormat to display a better-looking decimal value.

How can I save an image with PIL?

You should be able to simply let PIL get the filetype from extension, i.e. use:

j.save("C:/Users/User/Desktop/mesh_trans.bmp")

How to forward declare a template class in namespace std?

The problem is not that you can't forward-declare a template class. Yes, you do need to know all of the template parameters and their defaults to be able to forward-declare it correctly:

namespace std {
  template<class T, class Allocator = std::allocator<T>>
  class list;
}

But to make even such a forward declaration in namespace std is explicitly prohibited by the standard: the only thing you're allowed to put in std is a template specialisation, commonly std::less on a user-defined type. Someone else can cite the relevant text if necessary.

Just #include <list> and don't worry about it.

Oh, incidentally, any name containing double-underscores is reserved for use by the implementation, so you should use something like TEST_H instead of __TEST__. It's not going to generate a warning or an error, but if your program has a clash with an implementation-defined identifier, then it's not guaranteed to compile or run correctly: it's ill-formed. Also prohibited are names beginning with an underscore followed by a capital letter, among others. In general, don't start things with underscores unless you know what magic you're dealing with.

What does this thread join code mean?

From oracle documentation page on Joins

The join method allows one thread to wait for the completion of another.

If t1 is a Thread object whose thread is currently executing,

t1.join() : causes the current thread to pause execution until t1's thread terminates.

If t2 is a Thread object whose thread is currently executing,

t2.join(); causes the current thread to pause execution until t2's thread terminates.

join API is low level API, which has been introduced in earlier versions of java. Lot of things have been changed over a period of time (especially with jdk 1.5 release) on concurrency front.

You can achieve the same with java.util.concurrent API. Some of the examples are

  1. Using invokeAll on ExecutorService
  2. Using CountDownLatch
  3. Using ForkJoinPool or newWorkStealingPool of Executors(since java 8)

Refer to related SE questions:

wait until all threads finish their work in java

How to insert 1000 rows at a time

You can use the following CTE as well. You can just modify it as you find fit. But this will add the same values into the student CTE.

This will add 1000 records but you can change it to 10000 or to a maximum of 32767

;WITH thetable(rowid,sname,semail,spassword) AS
(
    SELECT 1  , 'name' , 'email' , 'password'
    UNION ALL
    SELECT rowid+1 ,'name' , 'email' , 'password' 
    FROM thetable WHERE rowid < 1000
)

SELECT rowid,sname,semail,spassword 
FROM thetable ORDER BY rowid
OPTION (MAXRECURSION 1000);

How to set cookies in laravel 5 independently inside controller

You may try this:

Cookie::queue($name, $value, $minutes);

This will queue the cookie to use it later and later it will be added with the response when response is ready to be sent. You may check the documentation on Laravel website.

Update (Retrieving A Cookie Value):

$value = Cookie::get('name');

Note: If you set a cookie in the current request then you'll be able to retrieve it on the next subsequent request.

Does delete on a pointer to a subclass call the base class destructor?

No. the pointer will be deleted. You should call the delete on A explicit in the destructor of B.

Sort a single String in Java

Without using Collections in Java:

import java.util.Scanner;

public class SortingaString {
    public static String Sort(String s1)
    {
        char ch[]=s1.toCharArray();         
        String res=" ";
        
        for(int i=0; i<ch.length ; i++)
        {
            for(int j=i+1;j<ch.length; j++)
            {
                if(ch[i]>=ch[j])
                {
                    char m=ch[i];
                    ch[i]=ch[j];
                    ch[j]=m;
                }
            }
            
            res=res+ch[i];
            
        }

        return res;
    }

    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        System.out.println("enter the string");
        
        String s1=sc.next();
        String ans=Sort( s1);
        
        System.out.println("after sorting=="+ans);
    }
}

Output:

enter the string==

sorting

after sorting== ginorst

C++ printing spaces or tabs given a user input integer

cout << "Enter amount of spaces you would like (integer)" << endl; 
cin >> n;
//print n spaces
for (int i = 0; i < n; ++i)
{
   cout << " " ;
}
cout <<endl;

What is the best algorithm for overriding GetHashCode?

This is a static helper class that implements Josh Bloch's implementation; and provides explicit overloads to "prevent" boxing, and also to implement the hash specifically for the long primitives.

You can pass a string comparison that matches your equals implementation.

Because the Hash output is always an int, you can just chain Hash calls.

using System;
using System.Collections;
using System.Collections.Generic;
using System.Reflection;
using System.Runtime.CompilerServices;


namespace Sc.Util.System
{
    /// <summary>
    /// Static methods that allow easy implementation of hashCode. Example usage:
    /// <code>
    /// public override int GetHashCode()
    ///     => HashCodeHelper.Seed
    ///         .Hash(primitiveField)
    ///         .Hsh(objectField)
    ///         .Hash(iEnumerableField);
    /// </code>
    /// </summary>
    public static class HashCodeHelper
    {
        /// <summary>
        /// An initial value for a hashCode, to which is added contributions from fields.
        /// Using a non-zero value decreases collisions of hashCode values.
        /// </summary>
        public const int Seed = 23;

        private const int oddPrimeNumber = 37;


        /// <summary>
        /// Rotates the seed against a prime number.
        /// </summary>
        /// <param name="aSeed">The hash's first term.</param>
        /// <returns>The new hash code.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        private static int rotateFirstTerm(int aSeed)
        {
            unchecked {
                return HashCodeHelper.oddPrimeNumber * aSeed;
            }
        }


        /// <summary>
        /// Contributes a boolean to the developing HashCode seed.
        /// </summary>
        /// <param name="aSeed">The developing HashCode value or seed.</param>
        /// <param name="aBoolean">The value to contribute.</param>
        /// <returns>The new hash code.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int Hash(this int aSeed, bool aBoolean)
        {
            unchecked {
                return HashCodeHelper.rotateFirstTerm(aSeed)
                        + (aBoolean
                                ? 1
                                : 0);
            }
        }

        /// <summary>
        /// Contributes a char to the developing HashCode seed.
        /// </summary>
        /// <param name="aSeed">The developing HashCode value or seed.</param>
        /// <param name="aChar">The value to contribute.</param>
        /// <returns>The new hash code.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int Hash(this int aSeed, char aChar)
        {
            unchecked {
                return HashCodeHelper.rotateFirstTerm(aSeed)
                        + aChar;
            }
        }

        /// <summary>
        /// Contributes an int to the developing HashCode seed.
        /// Note that byte and short are handled by this method, through implicit conversion.
        /// </summary>
        /// <param name="aSeed">The developing HashCode value or seed.</param>
        /// <param name="aInt">The value to contribute.</param>
        /// <returns>The new hash code.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int Hash(this int aSeed, int aInt)
        {
            unchecked {
                return HashCodeHelper.rotateFirstTerm(aSeed)
                        + aInt;
            }
        }

        /// <summary>
        /// Contributes a long to the developing HashCode seed.
        /// </summary>
        /// <param name="aSeed">The developing HashCode value or seed.</param>
        /// <param name="aLong">The value to contribute.</param>
        /// <returns>The new hash code.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int Hash(this int aSeed, long aLong)
        {
            unchecked {
                return HashCodeHelper.rotateFirstTerm(aSeed)
                        + (int)(aLong ^ (aLong >> 32));
            }
        }

        /// <summary>
        /// Contributes a float to the developing HashCode seed.
        /// </summary>
        /// <param name="aSeed">The developing HashCode value or seed.</param>
        /// <param name="aFloat">The value to contribute.</param>
        /// <returns>The new hash code.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int Hash(this int aSeed, float aFloat)
        {
            unchecked {
                return HashCodeHelper.rotateFirstTerm(aSeed)
                        + Convert.ToInt32(aFloat);
            }
        }

        /// <summary>
        /// Contributes a double to the developing HashCode seed.
        /// </summary>
        /// <param name="aSeed">The developing HashCode value or seed.</param>
        /// <param name="aDouble">The value to contribute.</param>
        /// <returns>The new hash code.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int Hash(this int aSeed, double aDouble)
            => aSeed.Hash(Convert.ToInt64(aDouble));

        /// <summary>
        /// Contributes a string to the developing HashCode seed.
        /// </summary>
        /// <param name="aSeed">The developing HashCode value or seed.</param>
        /// <param name="aString">The value to contribute.</param>
        /// <param name="stringComparison">Optional comparison that creates the hash.</param>
        /// <returns>The new hash code.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int Hash(
                this int aSeed,
                string aString,
                StringComparison stringComparison = StringComparison.Ordinal)
        {
            if (aString == null)
                return aSeed.Hash(0);
            switch (stringComparison) {
                case StringComparison.CurrentCulture :
                    return StringComparer.CurrentCulture.GetHashCode(aString);
                case StringComparison.CurrentCultureIgnoreCase :
                    return StringComparer.CurrentCultureIgnoreCase.GetHashCode(aString);
                case StringComparison.InvariantCulture :
                    return StringComparer.InvariantCulture.GetHashCode(aString);
                case StringComparison.InvariantCultureIgnoreCase :
                    return StringComparer.InvariantCultureIgnoreCase.GetHashCode(aString);
                case StringComparison.OrdinalIgnoreCase :
                    return StringComparer.OrdinalIgnoreCase.GetHashCode(aString);
                default :
                    return StringComparer.Ordinal.GetHashCode(aString);
            }
        }

        /// <summary>
        /// Contributes a possibly-null array to the developing HashCode seed.
        /// Each element may be a primitive, a reference, or a possibly-null array.
        /// </summary>
        /// <param name="aSeed">The developing HashCode value or seed.</param>
        /// <param name="aArray">CAN be null.</param>
        /// <returns>The new hash code.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int Hash(this int aSeed, IEnumerable aArray)
        {
            if (aArray == null)
                return aSeed.Hash(0);
            int countPlusOne = 1; // So it differs from null
            foreach (object item in aArray) {
                ++countPlusOne;
                if (item is IEnumerable arrayItem) {
                    if (!object.ReferenceEquals(aArray, arrayItem))
                        aSeed = aSeed.Hash(arrayItem); // recursive call!
                } else
                    aSeed = aSeed.Hash(item);
            }
            return aSeed.Hash(countPlusOne);
        }

        /// <summary>
        /// Contributes a possibly-null array to the developing HashCode seed.
        /// You must provide the hash function for each element.
        /// </summary>
        /// <param name="aSeed">The developing HashCode value or seed.</param>
        /// <param name="aArray">CAN be null.</param>
        /// <param name="hashElement">Required: yields the hash for each element
        /// in <paramref name="aArray"/>.</param>
        /// <returns>The new hash code.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int Hash<T>(this int aSeed, IEnumerable<T> aArray, Func<T, int> hashElement)
        {
            if (aArray == null)
                return aSeed.Hash(0);
            int countPlusOne = 1; // So it differs from null
            foreach (T item in aArray) {
                ++countPlusOne;
                aSeed = aSeed.Hash(hashElement(item));
            }
            return aSeed.Hash(countPlusOne);
        }

        /// <summary>
        /// Contributes a possibly-null object to the developing HashCode seed.
        /// </summary>
        /// <param name="aSeed">The developing HashCode value or seed.</param>
        /// <param name="aObject">CAN be null.</param>
        /// <returns>The new hash code.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int Hash(this int aSeed, object aObject)
        {
            switch (aObject) {
                case null :
                    return aSeed.Hash(0);
                case bool b :
                    return aSeed.Hash(b);
                case char c :
                    return aSeed.Hash(c);
                case int i :
                    return aSeed.Hash(i);
                case long l :
                    return aSeed.Hash(l);
                case float f :
                    return aSeed.Hash(f);
                case double d :
                    return aSeed.Hash(d);
                case string s :
                    return aSeed.Hash(s);
                case IEnumerable iEnumerable :
                    return aSeed.Hash(iEnumerable);
            }
            return aSeed.Hash(aObject.GetHashCode());
        }


        /// <summary>
        /// This utility method uses reflection to iterate all specified properties that are readable
        /// on the given object, excluding any property names given in the params arguments, and
        /// generates a hashcode.
        /// </summary>
        /// <param name="aSeed">The developing hash code, or the seed: if you have no seed, use
        /// the <see cref="Seed"/>.</param>
        /// <param name="aObject">CAN be null.</param>
        /// <param name="propertySelector"><see cref="BindingFlags"/> to select the properties to hash.</param>
        /// <param name="ignorePropertyNames">Optional.</param>
        /// <returns>A hash from the properties contributed to <c>aSeed</c>.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int HashAllProperties(
                this int aSeed,
                object aObject,
                BindingFlags propertySelector
                        = BindingFlags.Instance
                        | BindingFlags.Public
                        | BindingFlags.GetProperty,
                params string[] ignorePropertyNames)
        {
            if (aObject == null)
                return aSeed.Hash(0);
            if ((ignorePropertyNames != null)
                    && (ignorePropertyNames.Length != 0)) {
                foreach (PropertyInfo propertyInfo in aObject.GetType()
                        .GetProperties(propertySelector)) {
                    if (!propertyInfo.CanRead
                            || (Array.IndexOf(ignorePropertyNames, propertyInfo.Name) >= 0))
                        continue;
                    aSeed = aSeed.Hash(propertyInfo.GetValue(aObject));
                }
            } else {
                foreach (PropertyInfo propertyInfo in aObject.GetType()
                        .GetProperties(propertySelector)) {
                    if (propertyInfo.CanRead)
                        aSeed = aSeed.Hash(propertyInfo.GetValue(aObject));
                }
            }
            return aSeed;
        }


        /// <summary>
        /// NOTICE: this method is provided to contribute a <see cref="KeyValuePair{TKey,TValue}"/> to
        /// the developing HashCode seed; by hashing the key and the value independently. HOWEVER,
        /// this method has a different name since it will not be automatically invoked by
        /// <see cref="Hash(int,object)"/>, <see cref="Hash(int,IEnumerable)"/>,
        /// or <see cref="HashAllProperties"/> --- you MUST NOT mix this method with those unless
        /// you are sure that no KeyValuePair instances will be passed to those methods; or otherwise
        /// the generated hash code will not be consistent. This method itself ALSO will not invoke
        /// this method on the Key or Value here if that itself is a KeyValuePair.
        /// </summary>
        /// <param name="aSeed">The developing HashCode value or seed.</param>
        /// <param name="keyValuePair">The value to contribute.</param>
        /// <returns>The new hash code.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int HashKeyAndValue<TKey, TValue>(this int aSeed, KeyValuePair<TKey, TValue> keyValuePair)
            => aSeed.Hash(keyValuePair.Key)
                    .Hash(keyValuePair.Value);

        /// <summary>
        /// NOTICE: this method is provided to contribute a collection of <see cref="KeyValuePair{TKey,TValue}"/>
        /// to the developing HashCode seed; by hashing the key and the value independently. HOWEVER,
        /// this method has a different name since it will not be automatically invoked by
        /// <see cref="Hash(int,object)"/>, <see cref="Hash(int,IEnumerable)"/>,
        /// or <see cref="HashAllProperties"/> --- you MUST NOT mix this method with those unless
        /// you are sure that no KeyValuePair instances will be passed to those methods; or otherwise
        /// the generated hash code will not be consistent. This method itself ALSO will not invoke
        /// this method on a Key or Value here if that itself is a KeyValuePair or an Enumerable of
        /// KeyValuePair.
        /// </summary>
        /// <param name="aSeed">The developing HashCode value or seed.</param>
        /// <param name="keyValuePairs">The values to contribute.</param>
        /// <returns>The new hash code.</returns>
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static int HashKeysAndValues<TKey, TValue>(
                this int aSeed,
                IEnumerable<KeyValuePair<TKey, TValue>> keyValuePairs)
        {
            if (keyValuePairs == null)
                return aSeed.Hash(null);
            foreach (KeyValuePair<TKey, TValue> keyValuePair in keyValuePairs) {
                aSeed = aSeed.HashKeyAndValue(keyValuePair);
            }
            return aSeed;
        }
    }
}

How to convert CLOB to VARCHAR2 inside oracle pl/sql

Converting VARCHAR2 to CLOB

In PL/SQL a CLOB can be converted to a VARCHAR2 with a simple assignment, SUBSTR, and other methods. A simple assignment will only work if the CLOB is less then or equal to the size of the VARCHAR2. The limit is 32767 in PL/SQL and 4000 in SQL (although 12c allows 32767 in SQL).

For example, this code converts a small CLOB through a simple assignment and then coverts the beginning of a larger CLOB.

declare
    v_small_clob clob := lpad('0', 1000, '0');
    v_large_clob clob := lpad('0', 32767, '0') || lpad('0', 32767, '0');
    v_varchar2   varchar2(32767);
begin
    v_varchar2 := v_small_clob;
    v_varchar2 := substr(v_large_clob, 1, 32767);
end;

LONG?

The above code does not convert the value to a LONG. It merely looks that way because of limitations with PL/SQL debuggers and strings over 999 characters long.

For example, in PL/SQL Developer, open a Test window and add and debug the above code. Right-click on v_varchar2 and select "Add variable to Watches". Step through the code and the value will be set to "(Long Value)". There is a ... next to the text but it does not display the contents. PLSQL Developer Long Value

C#?

I suspect the real problem here is with C# but I don't know how enough about C# to debug the problem.

Keyboard shortcut to comment lines in Sublime Text 3

In Windows use ctrl + shift + : to comment for Python.

PHP code to remove everything but numbers

a much more practical way for those who do not want to use regex:

$data = filter_var($data, FILTER_SANITIZE_NUMBER_INT);

note: it works with phone numbers too.

How to compare each item in a list with the rest, only once?

Your solution is correct, but your outer loop is still longer than needed. You don't need to compare the last element with anything else because it's been already compared with all the others in the previous iterations. Your inner loop still prevents that, but since we're talking about collision detection you can save the unnecessary check.

Using the same language you used to illustrate your algorithm, you'd come with something like this:

for (int i = 0, i < mylist.size() - 1; ++i)
    for (int j = i + 1, j < mylist.size(); --j)
        compare(mylist[i], mylist[j])

CSS Background Image Not Displaying

If your path is correct then I think you don't have any element in you body section. Just define the height of the body and your code will work.

Modulo operator with negative values

The sign in such cases (i.e when one or both operands are negative) is implementation-defined. The spec says in §5.6/4 (C++03),

The binary / operator yields the quotient, and the binary % operator yields the remainder from the division of the first expression by the second. If the second operand of / or % is zero the behavior is undefined; otherwise (a/b)*b + a%b is equal to a. If both operands are nonnegative then the remainder is nonnegative; if not, the sign of the remainder is implementation-defined.

That is all the language has to say, as far as C++03 is concerned.

What is the alternative for ~ (user's home directory) on Windows command prompt?

Just wrote a script to do this without too much typing while maintaining portability as setting ~ to be %userprofile% needs a manual setup on each Windows PC while cloning and setting the directory as part of the PATH is mechanical.

https://github.com/yxliang01/Snippets/blob/master/windows/

"Actual or formal argument lists differs in length"

You try to instantiate an object of the Friends class like this:

Friends f = new Friends(friendsName, friendsAge);

The class does not have a constructor that takes parameters. You should either add the constructor, or create the object using the constructor that does exist and then use the set-methods. For example, instead of the above:

Friends f = new Friends();
f.setName(friendsName);
f.setAge(friendsAge);

How to use wait and notify in Java without IllegalMonitorStateException?

I'll right simple example show you the right way to use wait and notify in Java. So I'll create two class named ThreadA & ThreadB. ThreadA will call ThreadB.

public class ThreadA {
    public static void main(String[] args){
        ThreadB b = new ThreadB();//<----Create Instance for seconde class
        b.start();//<--------------------Launch thread

        synchronized(b){
            try{
                System.out.println("Waiting for b to complete...");
                b.wait();//<-------------WAIT until the finish thread for class B finish
            }catch(InterruptedException e){
                e.printStackTrace();
            }

            System.out.println("Total is: " + b.total);
        }
    }
} 

and for Class ThreadB:

class ThreadB extends Thread{
    int total;
    @Override
    public void run(){
        synchronized(this){
            for(int i=0; i<100 ; i++){
                total += i;
            }
            notify();//<----------------Notify the class wich wait until my    finish 
//and tell that I'm finish
            }
        }
    }

Get current directory name (without full path) in a Bash script

This thread is great! Here is one more flavor:

pwd | awk -F / '{print $NF}'

Error # 1045 - Cannot Log in to MySQL server -> phpmyadmin

sudo service mysql stop

sudo mysqld --skip-grant-tables &

mysql -u root mysql

Change MYSECRET with your new root password

UPDATE user SET Password=PASSWORD('MYSECRET') WHERE User='root'; FLUSH PRIVILEGES; exit;

error: member access into incomplete type : forward declaration of

Move doSomething definition outside of its class declaration and after B and also make add accessible to A by public-ing it or friend-ing it.

class B;

class A
{
    void doSomething(B * b);
};

class B
{
public:
    void add() {}
};

void A::doSomething(B * b)
{
    b->add();
}

How to assign string to bytes array

Arrays are values... slices are more like pointers. That is [n]type is not compatible with []type as they are fundamentally two different things. You can get a slice that points to an array by using arr[:] which returns a slice that has arr as it's backing storage.

One way to convert a slice of for example []byte to [20]byte is to actually allocate a [20]byte which you can do by using var [20]byte (as it's a value... no make needed) and then copy data into it:

buf := make([]byte, 10)
var arr [10]byte
copy(arr[:], buf)

Essentially what a lot of other answers get wrong is that []type is NOT an array.

[n]T and []T are completely different things!

When using reflect []T is not of kind Array but of kind Slice and [n]T is of kind Array.

You also can't use map[[]byte]T but you can use map[[n]byte]T.

This can sometimes be cumbersome because a lot of functions operate for example on []byte whereas some functions return [n]byte (most notably the hash functions in crypto/*). A sha256 hash for example is [32]byte and not []byte so when beginners try to write it to a file for example:

sum := sha256.Sum256(data)
w.Write(sum)

they will get an error. The correct way of is to use

w.Write(sum[:])

However, what is it that you want? Just accessing the string bytewise? You can easily convert a string to []byte using:

bytes := []byte(str)

but this isn't an array, it's a slice. Also, byte != rune. In case you want to operate on "characters" you need to use rune... not byte.

Getting Google+ profile picture url with user_id

UPDATE: Google stopped support for this method, that now returns a 404 (not found) error.


All this urls fetch the profile picture of a user:

https://www.google.com/s2/photos/profile/{user_id}
https://plus.google.com/s2/photos/profile/{user_id}
https://profiles.google.com/s2/photos/profile/{user_id}

They redirect to the same image url you get from Google API, an ugly link as
lh6.googleusercontent.com/-x1W2-XNKA-A/AAAAAAAAAAI/AAAAAAAAAAA/ooSNulbLz8U/photo.jpg

The simplest is to directly use like image source:

<img src="https://www.google.com/s2/photos/profile/{user_id}">

Otherwise to obtain exactly the same url of a Google API call you can read image headers,
for example in PHP:

$headers = get_headers("https://www.google.com/s2/photos/profile/{user_id}", 1);
echo "<img src=$headers[Location]>";

as described in article Fetch Google Plus Profile Picture using PHP.

How to list all the files in a commit?

try this command for name and changes number of line

git show --stat <commit-hash>

only show file names

git show --stat --name-only  <commit-hash>

for get last commit hash then try this command

git log -1

last commit with show files name and file status modify,create or delete

 git log -1 --oneline --name-status <commit-hash>

or for all

git log

for more advanced git log information read this article

https://devhints.io/git-log-format

https://devhints.io/git-log

CKEditor instance already exists

You can remove any ckeditor instance by remove method of ckeditor. Instance will be id or name of the textarea.

if (CKEDITOR.instances[instance_name]) {
    CKEDITOR.remove(CKEDITOR.instances[instance_name]);
}

CSS property to pad text inside of div

Padding is a way to add kind of a margin inside the Div.
Just Use

div { padding-left: 20px; }

And to mantain the size, you would have to -20px from the original width of the Div.

Convert file to byte array and vice versa

There is no such functionality but you can use a temporary file by File.createTempFile().

File temp = File.createTempFile(prefix, suffix);
// tell system to delete it when vm terminates.
temp.deleteOnExit();

ValidateRequest="false" doesn't work in Asp.Net 4

This works without changing the validation mode.

You have to use a System.Web.Helpers.Validation.Unvalidated helper from System.Web.WebPages.dll. It is going to return a UnvalidatedRequestValues object which allows to access the form and QueryString without validation.

For example,

var queryValue = Server.UrlDecode(Request.Unvalidated("MyQueryKey"));

Works for me for MVC3 and .NET 4.

Read .mat files in Python

Having MATLAB 2014b or newer installed, the MATLAB engine for Python could be used:

import matlab.engine
eng = matlab.engine.start_matlab()
content = eng.load("example.mat", nargout=1)

AngularJS ng-repeat handle empty list case

With the newer versions of angularjs the correct answer to this question is to use ng-if:

<ul>
  <li ng-if="list.length === 0">( No items in this list yet! )</li>
  <li ng-repeat="item in list">{{ item }}</li>
</ul>

This solution will not flicker when the list is about to download either because the list has to be defined and with a length of 0 for the message to display.

Here is a plunker to show it in use: http://plnkr.co/edit/in7ha1wTlpuVgamiOblS?p=preview

Tip: You can also show a loading text or spinner:

  <li ng-if="!list">( Loading... )</li>

Design DFA accepting binary strings divisible by a number 'n'

Below, I have written an answer for n equals to 5, but you can apply same approach to draw DFAs for any value of n and 'any positional number system' e.g binary, ternary...

First lean the term 'Complete DFA', A DFA defined on complete domain in d:Q × S?Q is called 'Complete DFA'. In other words we can say; in transition diagram of complete DFA there is no missing edge (e.g. from each state in Q there is one outgoing edge present for every language symbol in S). Note: Sometime we define partial DFA as d ? Q × S?Q (Read: How does “d:Q × S?Q” read in the definition of a DFA).

Design DFA accepting Binary numbers divisible by number 'n':

Step-1: When you divide a number ? by n then reminder can be either 0, 1, ..., (n - 2) or (n - 1). If remainder is 0 that means ? is divisible by n otherwise not. So, in my DFA there will be a state qr that would be corresponding to a remainder value r, where 0 <= r <= (n - 1), and total number of states in DFA is n.
After processing a number string ? over S, the end state is qr implies that ? % n => r (% reminder operator).

In any automata, the purpose of a state is like memory element. A state in an atomata stores some information like fan's switch that can tell whether the fan is in 'off' or in 'on' state. For n = 5, five states in DFA corresponding to five reminder information as follows:

  1. State q0 reached if reminder is 0. State q0 is the final state(accepting state). It is also an initial state.
  2. State q1 reaches if reminder is 1, a non-final state.
  3. State q2 if reminder is 2, a non-final state.
  4. State q3 if reminder is 3, a non-final state.
  5. State q4 if reminder is 4, a non-final state.

Using above information, we can start drawing transition diagram TD of five states as follows:

fig-1
Figure-1

So, 5 states for 5 remainder values. After processing a string ? if end-state becomes q0 that means decimal equivalent of input string is divisible by 5. In above figure q0 is marked final state as two concentric circle.
Additionally, I have defined a transition rule d:(q0, 0)?q0 as a self loop for symbol '0' at state q0, this is because decimal equivalent of any string consist of only '0' is 0 and 0 is a divisible by n.

Step-2: TD above is incomplete; and can only process strings of '0's. Now add some more edges so that it can process subsequent number's strings. Check table below, shows new transition rules those can be added next step:

+-------------------------------------+
¦Number¦Binary¦Remainder(%5)¦End-state¦
+------+------+-------------+---------¦
¦One   ¦1     ¦1            ¦q1       ¦
+------+------+-------------+---------¦
¦Two   ¦10    ¦2            ¦q2       ¦
+------+------+-------------+---------¦
¦Three ¦11    ¦3            ¦q3       ¦
+------+------+-------------+---------¦
¦Four  ¦100   ¦4            ¦q4       ¦
+-------------------------------------+
  1. To process binary string '1' there should be a transition rule d:(q0, 1)?q1
  2. Two:- binary representation is '10', end-state should be q2, and to process '10', we just need to add one more transition rule d:(q1, 0)?q2
    Path: ?(q0)-1?(q1)-0?(q2)
  3. Three:- in binary it is '11', end-state is q3, and we need to add a transition rule d:(q1, 1)?q3
    Path: ?(q0)-1?(q1)-1?(q3)
  4. Four:- in binary '100', end-state is q4. TD already processes prefix string '10' and we just need to add a new transition rule d:(q2, 0)?q4
    Path: ?(q0)-1?(q1)-0?(q2)-0?(q4)

fig-2 Figure-2

Step-3: Five = 101
Above transition diagram in figure-2 is still incomplete and there are many missing edges, for an example no transition is defined for d:(q2, 1)-?. And the rule should be present to process strings like '101'.
Because '101' = 5 is divisible by 5, and to accept '101' I will add d:(q2, 1)?q0 in above figure-2.
Path: ?(q0)-1?(q1)-0?(q2)-1?(q0)
with this new rule, transition diagram becomes as follows:

fig-3 Figure-3

Below in each step I pick next subsequent binary number to add a missing edge until I get TD as a 'complete DFA'.

Step-4: Six = 110.

We can process '11' in present TD in figure-3 as: ?(q0)-11?(q3) -0?(?). Because 6 % 5 = 1 this means to add one rule d:(q3, 0)?q1.

fig-4 Figure-4

Step-5: Seven = 111

+--------------------------------------------------------------+
¦Number¦Binary¦Remainder(%5)¦End-state¦ Path       ¦ Add       ¦
+------+------+-------------+---------+------------+-----------¦
¦Seven ¦111   ¦7 % 5 = 2    ¦q2       ¦ q0-11?q3   ¦ q3-1?q2    ¦
+--------------------------------------------------------------+

fig-5 Figure-5

Step-6: Eight = 1000

+----------------------------------------------------------+
¦Number¦Binary¦Remainder(%5)¦End-state¦ Path     ¦ Add     ¦
+------+------+-------------+---------+----------+---------¦
¦Eight ¦1000  ¦8 % 5 = 3    ¦q3       ¦q0-100?q4 ¦ q4-0?q3  ¦
+----------------------------------------------------------+

fig-6 Figure-6

Step-7: Nine = 1001

+----------------------------------------------------------+
¦Number¦Binary¦Remainder(%5)¦End-state¦ Path     ¦ Add     ¦
+------+------+-------------+---------+----------+---------¦
¦Nine  ¦1001  ¦9 % 5 = 4    ¦q4       ¦q0-100?q4 ¦ q4-1?q4  ¦
+----------------------------------------------------------+

fig-7 Figure-7

In TD-7, total number of edges are 10 == Q × S = 5 × 2. And it is a complete DFA that can accept all possible binary strings those decimal equivalent is divisible by 5.

Design DFA accepting Ternary numbers divisible by number n:

Step-1 Exactly same as for binary, use figure-1.

Step-2 Add Zero, One, Two

+------------------------------------------------------+
¦Decimal¦Ternary¦Remainder(%5)¦End-state¦   Add        ¦
+-------+-------+-------------+---------+--------------¦
¦Zero   ¦0      ¦0            ¦q0       ¦ d:(q0,0)?q0  ¦
+-------+-------+-------------+---------+--------------¦
¦One    ¦1      ¦1            ¦q1       ¦ d:(q0,1)?q1  ¦
+-------+-------+-------------+---------+--------------¦
¦Two    ¦2      ¦2            ¦q2       ¦ d:(q0,2)?q3  ¦
+------------------------------------------------------+

fig-8
Figure-8

Step-3 Add Three, Four, Five

+-----------------------------------------------------+
¦Decimal¦Ternary¦Remainder(%5)¦End-state¦  Add        ¦
+-------+-------+-------------+---------+-------------¦
¦Three  ¦10     ¦3            ¦q3       ¦ d:(q1,0)?q3 ¦
+-------+-------+-------------+---------+-------------¦
¦Four   ¦11     ¦4            ¦q4       ¦ d:(q1,1)?q4 ¦
+-------+-------+-------------+---------+-------------¦
¦Five   ¦12     ¦0            ¦q0       ¦ d:(q1,2)?q0 ¦
+-----------------------------------------------------+

fig-9
Figure-9

Step-4 Add Six, Seven, Eight

+-----------------------------------------------------+
¦Decimal¦Ternary¦Remainder(%5)¦End-state¦  Add        ¦
+-------+-------+-------------+---------+-------------¦
¦Six    ¦20     ¦1            ¦q1       ¦ d:(q2,0)?q1 ¦
+-------+-------+-------------+---------+-------------¦
¦Seven  ¦21     ¦2            ¦q2       ¦ d:(q2,1)?q2 ¦
+-------+-------+-------------+---------+-------------¦
¦Eight  ¦22     ¦3            ¦q3       ¦ d:(q2,2)?q3 ¦
+-----------------------------------------------------+

fig-10
Figure-10

Step-5 Add Nine, Ten, Eleven

+-----------------------------------------------------+
¦Decimal¦Ternary¦Remainder(%5)¦End-state¦  Add        ¦
+-------+-------+-------------+---------+-------------¦
¦Nine   ¦100    ¦4            ¦q4       ¦ d:(q3,0)?q4 ¦
+-------+-------+-------------+---------+-------------¦
¦Ten    ¦101    ¦0            ¦q0       ¦ d:(q3,1)?q0 ¦
+-------+-------+-------------+---------+-------------¦
¦Eleven ¦102    ¦1            ¦q1       ¦ d:(q3,2)?q1 ¦
+-----------------------------------------------------+

fig-11
Figure-11

Step-6 Add Twelve, Thirteen, Fourteen

+------------------------------------------------------+
¦Decimal ¦Ternary¦Remainder(%5)¦End-state¦  Add        ¦
+--------+-------+-------------+---------+-------------¦
¦Twelve  ¦110    ¦2            ¦q2       ¦ d:(q4,0)?q2 ¦
+--------+-------+-------------+---------+-------------¦
¦Thirteen¦111    ¦3            ¦q3       ¦ d:(q4,1)?q3 ¦
+--------+-------+-------------+---------+-------------¦
¦Fourteen¦112    ¦4            ¦q4       ¦ d:(q4,2)?q4 ¦
+------------------------------------------------------+

fig-12
Figure-12

Total number of edges in transition diagram figure-12 are 15 = Q × S = 5 * 3 (a complete DFA). And this DFA can accept all strings consist over {0, 1, 2} those decimal equivalent is divisible by 5.
If you notice at each step, in table there are three entries because at each step I add all possible outgoing edge from a state to make a complete DFA (and I add an edge so that qr state gets for remainder is r)!

To add further, remember union of two regular languages are also a regular. If you need to design a DFA that accepts binary strings those decimal equivalent is either divisible by 3 or 5, then draw two separate DFAs for divisible by 3 and 5 then union both DFAs to construct target DFA (for 1 <= n <= 10 your have to union 10 DFAs).

If you are asked to draw DFA that accepts binary strings such that decimal equivalent is divisible by 5 and 3 both then you are looking for DFA of divisible by 15 ( but what about 6 and 8?).

Note: DFAs drawn with this technique will be minimized DFA only when there is no common factor between number n and base e.g. there is no between 5 and 2 in first example, or between 5 and 3 in second example, hence both DFAs constructed above are minimized DFAs. If you are interested to read further about possible mini states for number n and base b read paper: Divisibility and State Complexity.

below I have added a Python script, I written it for fun while learning Python library pygraphviz. I am adding it I hope it can be helpful for someone in someway.

Design DFA for base 'b' number strings divisible by number 'n':

So we can apply above trick to draw DFA to recognize number strings in any base 'b' those are divisible a given number 'n'. In that DFA total number of states will be n (for n remainders) and number of edges should be equal to 'b' * 'n' — that is complete DFA: 'b' = number of symbols in language of DFA and 'n' = number of states.

Using above trick, below I have written a Python Script to Draw DFA for input base and number. In script, function divided_by_N populates DFA's transition rules in base * number steps. In each step-num, I convert num into number string num_s using function baseN(). To avoid processing each number string, I have used a temporary data-structure lookup_table. In each step, end-state for number string num_s is evaluated and stored in lookup_table to use in next step.

For transition graph of DFA, I have written a function draw_transition_graph using Pygraphviz library (very easy to use). To use this script you need to install graphviz. To add colorful edges in transition diagram, I randomly generates color codes for each symbol get_color_dict function.

#!/usr/bin/env python
import pygraphviz as pgv
from pprint import pprint
from random import choice as rchoice

def baseN(n, b, syms="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"):
    """ converts a number `n` into base `b` string """
    return ((n == 0) and syms[0]) or (
        baseN(n//b, b, syms).lstrip(syms[0]) + syms[n % b])

def divided_by_N(number, base):
    """
    constructs DFA that accepts given `base` number strings
    those are divisible by a given `number`
    """
    ACCEPTING_STATE = START_STATE = '0'
    SYMBOL_0 = '0'
    dfa = {
        str(from_state): {
            str(symbol): 'to_state' for symbol in range(base)
        }
        for from_state in range(number)
    }
    dfa[START_STATE][SYMBOL_0] = ACCEPTING_STATE
    # `lookup_table` keeps track: 'number string' -->[dfa]--> 'end_state'
    lookup_table = { SYMBOL_0: ACCEPTING_STATE }.setdefault
    for num in range(number * base):
        end_state = str(num % number)
        num_s = baseN(num, base)
        before_end_state = lookup_table(num_s[:-1], START_STATE)
        dfa[before_end_state][num_s[-1]] = end_state
        lookup_table(num_s, end_state)
    return dfa

def symcolrhexcodes(symbols):
    """
    returns dict of color codes mapped with alphabets symbol in symbols
    """
    return {
        symbol: '#'+''.join([
            rchoice("8A6C2B590D1F4E37") for _ in "FFFFFF"
        ])
        for symbol in symbols
    }

def draw_transition_graph(dfa, filename="filename"):
    ACCEPTING_STATE = START_STATE = '0'
    colors = symcolrhexcodes(dfa[START_STATE].keys())
    # draw transition graph
    tg = pgv.AGraph(strict=False, directed=True, decorate=True)
    for from_state in dfa:
        for symbol, to_state in dfa[from_state].iteritems():
            tg.add_edge("Q%s"%from_state, "Q%s"%to_state,
                        label=symbol, color=colors[symbol],
                        fontcolor=colors[symbol])

    # add intial edge from an invisible node!
    tg.add_node('null', shape='plaintext', label='start')
    tg.add_edge('null', "Q%s"%START_STATE,)

    # make end acception state as 'doublecircle'
    tg.get_node("Q%s"%ACCEPTING_STATE).attr['shape'] = 'doublecircle'
    tg.draw(filename, prog='circo')
    tg.close()

def print_transition_table(dfa):
    print("DFA accepting number string in base '%(base)s' "
            "those are divisible by '%(number)s':" % {
                'base': len(dfa['0']),
                'number': len(dfa),})
    pprint(dfa)

if __name__ == "__main__":
    number = input ("Enter NUMBER: ")
    base = input ("Enter BASE of number system: ")
    dfa = divided_by_N(number, base)

    print_transition_table(dfa)
    draw_transition_graph(dfa)

Execute it:

~/study/divide-5/script$ python script.py 
Enter NUMBER: 5
Enter BASE of number system: 4
DFA accepting number string in base '4' those are divisible by '5':
{'0': {'0': '0', '1': '1', '2': '2', '3': '3'},
 '1': {'0': '4', '1': '0', '2': '1', '3': '2'},
 '2': {'0': '3', '1': '4', '2': '0', '3': '1'},
 '3': {'0': '2', '1': '3', '2': '4', '3': '0'},
 '4': {'0': '1', '1': '2', '2': '3', '3': '4'}}
~/study/divide-5/script$ ls
script.py filename.png
~/study/divide-5/script$ display filename

Output:

base_4_divided_5_best
DFA accepting number strings in base 4 those are divisible by 5

Similarly, enter base = 4 and number = 7 to generate - dfa accepting number string in base '4' those are divisible by '7'
Btw, try changing filename to .png or .jpeg.

References those I use to write this script:
➊ Function baseN from "convert integer to a string in a given numeric base in python"
➋ To install "pygraphviz": "Python does not see pygraphviz"
➌ To learn use of Pygraphviz: "Python-FSM"
➍ To generate random hex color codes for each language symbol: "How would I make a random hexdigit code generator using .join and for loops?"

How can I use SUM() OVER()

if you are using SQL 2012 you should try

SELECT  ID, 
        AccountID, 
        Quantity, 
        SUM(Quantity) OVER (PARTITION BY AccountID ORDER BY AccountID rows between unbounded preceding and current row ) AS TopBorcT, 
FROM tCariH

if available, better order by date column.

What are these ^M's that keep showing up in my files in emacs?

If you don't have dos2unix utility installed on your system, you can create your own to get rid of Windows endline characters:

vi ~/dos2unix.bash:

with the following content

#!/bin/bash
tr -d '\r' < $1 > repl.tmp
mv -f repl.tmp $1

In your ~/.bashrc, add the line:

alias 'dos2unix=~/dos2unix.bash'

Applying

dos2unix file_from_PC.txt

will remove ^M characters at lines ends in file_from_PC.txt. You can check if you have those or not by using cat:

cat -v file_from_PC.txt

C# DateTime to UTC Time without changing the time

You can use the overloaded constructor of DateTime:

DateTime utcDateTime = new DateTime(dateTime.Year, dateTime.Month, dateTime.Day, dateTime.Hour, dateTime.Minute, dateTime.Second, DateTimeKind.Utc);

how to create virtual host on XAMPP

I'm a little late to the party, but I wrote this little bash script for Mac that creates a VirtualHost through the terminal:

#!/bin/bash

echo "Welcome to the VirtualHostCreator! Press <RETURN> to continue."

read

echo "Enter the name the VirtualHost you would like to create. No spaces or dashes, please."

read hostname

echo "Enter the document root of the VirtualHost."

read doc_root

echo "Creating VirtualHost \"$hostname\". You may be prompted for your password."

hosts_file="/etc/hosts"
vhosts_file="/Applications/XAMPP/xamppfiles/etc/extra/httpd-vhosts.conf"
restart_command="sudo /Applications/XAMPP/xamppfiles/xampp restart"

cat >> $vhosts_file << EndOfMessage
<VirtualHost ${hostname}>
    ServerName ${hostname}
    DocumentRoot "/Applications/XAMPP/xamppfiles/htdocs/${doc_root}"
</VirtualHost>
EndOfMessage

sudo sh -c "echo \"127.0.0.1       $hostname\" >> $hosts_file"

$restart_command

I'm sure there are a few improvements that can be made, and it only has the two required options for the vhost (server name and document root), but it does the job much more quickly and efficiently than opening and editing all the files manually, and also automatically restarts XAMPP afterwards.

This assumes that you have the default installation location for XAMPP, which can all be changed.

Understanding inplace=True

If you don't use inplace=True or you use inplace=False you basically get back a copy.

So for instance:

testdf.sort_values(inplace=True, by='volume', ascending=False)

will alter the structure with the data sorted in descending order.

then:

testdf2 = testdf.sort_values( by='volume', ascending=True)

will make testdf2 a copy. the values will all be the same but the sort will be reversed and you will have an independent object.

then given another column, say LongMA and you do:

testdf2.LongMA = testdf2.LongMA -1

the LongMA column in testdf will have the original values and testdf2 will have the decrimented values.

It is important to keep track of the difference as the chain of calculations grows and the copies of dataframes have their own lifecycle.

Storing JSON in database vs. having a new column for each key

You are trying to fit a non-relational model into a relational database, I think you would be better served using a NoSQL database such as MongoDB. There is no predefined schema which fits in with your requirement of having no limitation to the number of fields (see the typical MongoDB collection example). Check out the MongoDB documentation to get an idea of how you'd query your documents, e.g.

db.mycollection.find(
    {
      name: 'sann'
    }
)

Simultaneously merge multiple data.frames in a list

Another question asked specifically how to perform multiple left joins using dplyr in R . The question was marked as a duplicate of this one so I answer here, using the 3 sample data frames below:

x <- data.frame(i = c("a","b","c"), j = 1:3, stringsAsFactors=FALSE)
y <- data.frame(i = c("b","c","d"), k = 4:6, stringsAsFactors=FALSE)
z <- data.frame(i = c("c","d","a"), l = 7:9, stringsAsFactors=FALSE)

Update June 2018: I divided the answer in three sections representing three different ways to perform the merge. You probably want to use the purrr way if you are already using the tidyverse packages. For comparison purposes below, you'll find a base R version using the same sample dataset.


1) Join them with reduce from the purrr package:

The purrr package provides a reduce function which has a concise syntax:

library(tidyverse)
list(x, y, z) %>% reduce(left_join, by = "i")
#  A tibble: 3 x 4
#  i       j     k     l
#  <chr> <int> <int> <int>
# 1 a      1    NA     9
# 2 b      2     4    NA
# 3 c      3     5     7

You can also perform other joins, such as a full_join or inner_join:

list(x, y, z) %>% reduce(full_join, by = "i")
# A tibble: 4 x 4
# i       j     k     l
# <chr> <int> <int> <int>
# 1 a     1     NA     9
# 2 b     2     4      NA
# 3 c     3     5      7
# 4 d     NA    6      8

list(x, y, z) %>% reduce(inner_join, by = "i")
# A tibble: 1 x 4
# i       j     k     l
# <chr> <int> <int> <int>
# 1 c     3     5     7

2) dplyr::left_join() with base R Reduce():

list(x,y,z) %>%
    Reduce(function(dtf1,dtf2) left_join(dtf1,dtf2,by="i"), .)

#   i j  k  l
# 1 a 1 NA  9
# 2 b 2  4 NA
# 3 c 3  5  7

3) Base R merge() with base R Reduce():

And for comparison purposes, here is a base R version of the left join based on Charles's answer.

 Reduce(function(dtf1, dtf2) merge(dtf1, dtf2, by = "i", all.x = TRUE),
        list(x,y,z))
#   i j  k  l
# 1 a 1 NA  9
# 2 b 2  4 NA
# 3 c 3  5  7

Update one MySQL table with values from another

It depends what is a use of those tables, but you might consider putting trigger on original table on insert and update. When insert or update is done, update the second table based on only one item from the original table. It will be quicker.

Scikit-learn: How to obtain True Positive, True Negative, False Positive and False Negative

#False positive cases
train = pd.merge(X_train, y_train,left_index=True, right_index=True)
y_train_pred = pd.DataFrame(y_train_pred)
y_train_pred.rename(columns={0 :'Predicted'}, inplace=True )
train = train.reset_index(drop=True).merge(y_train_pred.reset_index(drop=True),
left_index=True,right_index=True)
train['FP'] = np.where((train['Banknote']=="Forged") & (train['Predicted']=="Genuine"),1,0)
train[train.FP != 0]

Automatically add all files in a folder to a target using CMake?

As of CMake 3.1+ the developers strongly discourage users from using file(GLOB or file(GLOB_RECURSE to collect lists of source files.

Note: We do not recommend using GLOB to collect a list of source files from your source tree. If no CMakeLists.txt file changes when a source is added or removed then the generated build system cannot know when to ask CMake to regenerate. The CONFIGURE_DEPENDS flag may not work reliably on all generators, or if a new generator is added in the future that cannot support it, projects using it will be stuck. Even if CONFIGURE_DEPENDS works reliably, there is still a cost to perform the check on every rebuild.

See the documentation here.

There are two goods answers ([1], [2]) here on SO detailing the reasons to manually list source files.


It is possible. E.g. with file(GLOB:

cmake_minimum_required(VERSION 2.8)

file(GLOB helloworld_SRC
     "*.h"
     "*.cpp"
)

add_executable(helloworld ${helloworld_SRC})

Note that this requires manual re-running of cmake if a source file is added or removed, since the generated build system does not know when to ask CMake to regenerate, and doing it at every build would increase the build time.

As of CMake 3.12, you can pass the CONFIGURE_DEPENDS flag to file(GLOB to automatically check and reset the file lists any time the build is invoked. You would write:

cmake_minimum_required(VERSION 3.12)

file(GLOB helloworld_SRC CONFIGURE_DEPENDS "*.h" "*.cpp")

This at least lets you avoid manually re-running CMake every time a file is added.

Double decimal formatting in Java

I know that this is an old topic, but If you really like to have the period instead of the comma, just save your result as X,00 into a String and then just simply change it for a period so you get the X.00

The simplest way is just to use replace.

String var = "X,00";
String newVar = var.replace(",",".");

The output will be the X.00 you wanted. Also to make it easy you can do it all at one and save it into a double variable:

Double var = Double.parseDouble(("X,00").replace(",",".");

I know that this reply is not useful right now but maybe someone that checks this forum will be looking for a quick solution like this.

toggle show/hide div with button?

This is how I hide and show content using a class. changing the class to nothing will change the display to block, changing the class to 'a' will show the display as none.

<!DOCTYPE html>
<html>
<head>
<style>
body  {
  background-color:#777777;
  }
block1{
  display:block; background-color:black; color:white; padding:20px; margin:20px;
  }
block1.a{
  display:none; background-color:black; color:white; padding:20px; margin:20px;
  }
</style>
</head>
<body>
<button onclick="document.getElementById('ID').setAttribute('class', '');">Open</button>
<button onclick="document.getElementById('ID').setAttribute('class', 'a');">Close</button>
<block1 id="ID" class="a">
<p>Testing</p>
</block1>
</body>
</html>

Sending private messages to user

If your looking to type up the message and then your bot will send it to the user, here is the code. It also has a role restriction on it :)

_x000D_
_x000D_
case 'dm':
  mentiondm = message.mentions.users.first();
  message.channel.bulkDelete(1);
  if (!message.member.roles.cache.some(role => role.name === "Owner")) return message.channel.send('Beep Boing: This command is way too powerful for you to use!');
  if (mentiondm == null) return message.reply('Beep Boing: No user to send message to!');
  mentionMessage = message.content.slice(3);
  mentiondm.send(mentionMessage);
  console.log('Message Sent!')
  break;
_x000D_
_x000D_
_x000D_

Where does PHP's error log reside in XAMPP?

As said above you can find PHP error log in windows. In c:\xampp\apache\logs\error.log. You can easily display the last logs by tail -f .\error.log

Check whether IIS is installed or not?

Refer this a step by step approach:

http://www.codeproject.com/Tips/365704/Install-IIS-on-Windows

For many users you have to enable the windows feature on then check IIS and then go with RUN followed by searching for inetmgr.

Checking whether the pip is installed?

Use command line and not python.
TLDR; On Windows, do:
python -m pip --version
OR
py -m pip --version

Details:

On Windows, ~> (open windows terminal)
Start (or Windows Key) > type "cmd" Press Enter
You should see a screen that looks like this enter image description here
To check to see if pip is installed.

python -m pip --version

if pip is installed, go ahead and use it. for example:

Z:\>python -m pip install selenium

if not installed, install pip, and you may need to
add its path to the environment variables.
(basic - windows)
add path to environment variables (basic+advanced)

if python is NOT installed you will get a result similar to the one below

enter image description here

Install python. add its path to environment variables.

UPDATE: for newer versions of python replace "python" with py - see @gimmegimme's comment and link https://packaging.python.org/guides/installing-using-pip-and-virtual-environments/

Integer to IP Address - C

Hint: break up the 32-bit integer to 4 8-bit integers, and print them out.

Something along the lines of this (not compiled, YMMV):

int i = 0xDEADBEEF; // some 32-bit integer
printf("%i.%i.%i.%i",
          (i >> 24) & 0xFF,
          (i >> 16) & 0xFF,
          (i >> 8) & 0xFF,
          i & 0xFF);

Skip over a value in the range function in python

what you could do, is put an if statement around everything inside the loop that you want kept away from the 50. e.g.

for i in range(0, len(list)):
    if i != 50:
        x= listRow(list, i)
        for j in range (#0 to len(list) not including x#)

Android Studio - No JVM Installation found

If it does not work after setting paths in environment variables correctly,
Reinstall Android Studio and it worked for me.

Convert a secure string to plain text

In PS 7, you can use ConvertFrom-SecureString and -AsPlainText:

 $UnsecurePassword = ConvertFrom-SecureString -SecureString $SecurePassword -AsPlainText

https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.security/ConvertFrom-SecureString?view=powershell-7#parameters

ConvertFrom-SecureString
           [-SecureString] <SecureString>
           [-AsPlainText]
           [<CommonParameters>]

Vector of Vectors to create matrix

You have to initialize the vector of vectors to the appropriate size before accessing any elements. You can do it like this:

// assumes using std::vector for brevity
vector<vector<int>> matrix(RR, vector<int>(CC));

This creates a vector of RR size CC vectors, filled with 0.

Add a CSS border on hover without moving the element

Try this it might solve your problem.

Css:

.item{padding-top:1px;}

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

HTML:

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

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

Determine which MySQL configuration file is being used

mysqld --help --verbose is dangerous. You can easily overwrite pidfile for running instance! use it with --pid-file=XYZ

Oh, and you can't really use it if you have more than 1 instance running. It will only show you default value.

Really good article about it:

How to find MySQL configuration file?

How can I get the baseurl of site?

I believe that the answers above doesn't consider when the site is not in the root of the website.

This is a for WebApi controller:

string baseUrl = (Url.Request.RequestUri.GetComponents(
                    UriComponents.SchemeAndServer, UriFormat.Unescaped).TrimEnd('/') 
                 + HttpContext.Current.Request.ApplicationPath).TrimEnd('/') ;

Your content must have a ListView whose id attribute is 'android.R.id.list'

One other thing that affected me: If you have multiple test devices, make sure you are making changes to the layout used by the device. In my case, I spent a while making changes to xmls in the "layout" directory until I discovered that my larger phone (which I switched to halfway through testing) was using xmls in the "layout-sw360dp" directory. Grrr!

Python: Assign Value if None Exists

I'm also coming from Ruby so I love the syntax foo ||= 7.

This is the closest thing I can find.

foo = foo if 'foo' in vars() else 7

I've seen people do this for a dict:

try:
    foo['bar']
except KeyError:
    foo['bar'] = 7

Upadate: However, I recently found this gem:

foo['bar'] = foo.get('bar', 7)

If you like that, then for a regular variable you could do something like this:

vars()['foo'] = vars().get('foo', 7)

Git SSH error: "Connect to host: Bad file number"

The key information is written in @Sam's answer but not really salient, so let's make it clear.

"Bad file number" is not informative, it's only a sign of running git's ssh on Windows.

The line which appears even without -v switch:

ssh: connect to host (some host or IP address) port 22: Bad file number

is actually irrelevant.

If you focus on it you'll waste your time as it is not a hint about what the actual problem is, just an effect of running git's ssh on Windows. It's not even a sign that the git or ssh install or configuration is wrong. Really, ignore it.

The very same command on Linux produced instead this message for me, which gave an actual hint about the problem:

ssh: connect to host (some host or IP address) port 22: Connection timed out

Actual solution: ignore "bad file number" and get more information

Focus on lines being added with -v on command line. In my case it was:

debug1: connect to address (some host or IP address) port 22: Attempt to connect timed out without establishing a connection

My problem was a typo in the IP address, but yours may be different.

Is this question about "bad file number", or about the many reasons why a connection could time out ?

If someone can prove that "bad file number" only appears when the actual reason is "connection time out" then it makes some sense to address why connection could time out.

Until that, "bad file number" is only a generic error message and this question is fully answered by saying "ignore it and look for other error messages".

EDIT: Qwertie mentioned that the error message is indeed generic, as it can happen on "Connection refused" also. This confirms the analysis.

Please don't clutter this question with general hints and answer, they have nothing to do with the actual topic (and title) of this question which is "Git SSH error: “Connect to host: Bad file number”". If using -v you have more informative message that deserve their own question, then open another question, then you can make a link to it.

How to fix Cannot find module 'typescript' in Angular 4?

I had a very similar problem after moving a working project to a new subdirectory on my file system. It turned out I had failed to move the file named .angular-cli.json to the subfolder along with everything else. After noticing that and moving the file into the subdirectory, all was back to normal.

Increment counter with loop

what led me to this page is that I set within a page then the inside of an included page I did the increment

and here is the problem

so to solve such a problem, simply use scope="request" when you declare the variable or the increment

//when you set the variale add scope="request"
<c:set var="nFilters" value="${0}" scope="request"/>
//the increment, it can be happened inside an included page
<c:set var="nFilters" value="${nFilters + 1}"  scope="request" />

hope this saves your time

How to add a changed file to an older (not last) commit in Git

Use git rebase. Specifically:

  1. Use git stash to store the changes you want to add.
  2. Use git rebase -i HEAD~10 (or however many commits back you want to see).
  3. Mark the commit in question (a0865...) for edit by changing the word pick at the start of the line into edit. Don't delete the other lines as that would delete the commits.[^vimnote]
  4. Save the rebase file, and git will drop back to the shell and wait for you to fix that commit.
  5. Pop the stash by using git stash pop
  6. Add your file with git add <file>.
  7. Amend the commit with git commit --amend --no-edit.
  8. Do a git rebase --continue which will rewrite the rest of your commits against the new one.
  9. Repeat from step 2 onwards if you have marked more than one commit for edit.

[^vimnote]: If you are using vim then you will have to hit the Insert key to edit, then Esc and type in :wq to save the file, quit the editor, and apply the changes. Alternatively, you can configure a user-friendly git commit editor with git config --global core.editor "nano".

How to count objects in PowerShell?

This will get you count:

get-alias | measure

You can work with the result as with object:

$m = get-alias | measure
$m.Count

And if you would like to have aliases in some variable also, you can use Tee-Object:

$m = get-alias | tee -Variable aliases | measure
$m.Count
$aliases

Some more info on Measure-Object cmdlet is on Technet.

Do not confuse it with Measure-Command cmdlet which is for time measuring. (again on Technet)

Detecting user leaving page with react-router

You can use this prompt.

import React, { Component } from "react";
import { BrowserRouter as Router, Route, Link, Prompt } from "react-router-dom";

function PreventingTransitionsExample() {
  return (
    <Router>
      <div>
        <ul>
          <li>
            <Link to="/">Form</Link>
          </li>
          <li>
            <Link to="/one">One</Link>
          </li>
          <li>
            <Link to="/two">Two</Link>
          </li>
        </ul>
        <Route path="/" exact component={Form} />
        <Route path="/one" render={() => <h3>One</h3>} />
        <Route path="/two" render={() => <h3>Two</h3>} />
      </div>
    </Router>
  );
}

class Form extends Component {
  state = { isBlocking: false };

  render() {
    let { isBlocking } = this.state;

    return (
      <form
        onSubmit={event => {
          event.preventDefault();
          event.target.reset();
          this.setState({
            isBlocking: false
          });
        }}
      >
        <Prompt
          when={isBlocking}
          message={location =>
            `Are you sure you want to go to ${location.pathname}`
          }
        />

        <p>
          Blocking?{" "}
          {isBlocking ? "Yes, click a link or the back button" : "Nope"}
        </p>

        <p>
          <input
            size="50"
            placeholder="type something to block transitions"
            onChange={event => {
              this.setState({
                isBlocking: event.target.value.length > 0
              });
            }}
          />
        </p>

        <p>
          <button>Submit to stop blocking</button>
        </p>
      </form>
    );
  }
}

export default PreventingTransitionsExample;

Trigger change event of dropdown

If you are trying to have linked drop downs, the best way to do it is to have a script that returns the a prebuilt select box and an AJAX call that requests it.

Here is the documentation for jQuery's Ajax method if you need it.

$(document).ready(function(){

    $('#countrylist').change(function(e){
        $this = $(e.target);
        $.ajax({
            type: "POST",
            url: "scriptname.asp", // Don't know asp/asp.net at all so you will have to do this bit
            data: { country: $this.val() },
            success:function(data){
                $('#stateBoxHook').html(data);
            }
        });
    });

});

Then have a span around your state select box with the id of "stateBoxHook"

How to call a function, PostgreSQL

I had this same issue while trying to test a very similar function that uses a SELECT statement to decide if a INSERT or an UPDATE should be done. This function was a re-write of a T-SQL stored procedure.
When I tested the function from the query window I got the error "query has no destination for result data". I finally figured out that because I used a SELECT statement inside the function that I could not test the function from the query window until I assigned the results of the SELECT to a local variable using an INTO statement. This fixed the problem.

If the original function in this thread was changed to the following it would work when called from the query window,

$BODY$
DECLARE
   v_temp integer;
BEGIN
SELECT 1 INTO v_temp
FROM "USERS"
WHERE "userID" = $1;

What does -save-dev mean in npm install grunt --save-dev

Documentation from npm for npm install <package-name> --save and npm install <package-name> --save-dev can be found here:

https://docs.npmjs.com/getting-started/using-a-package.json#the-save-and-save-dev-install-flags

A package.json file declares metadata about the module you are developing. Both aforementioned commands modify this package.json file. --save will declare the installed package (in this case, grunt) as a dependency for your module; --save-dev will declare it as a dependency for development of your module.

Ask yourself: will the installed package be required for use of my module, or will it only be required for developing it?

Invalid length for a Base-64 char array

The length of a base64 encoded string is always a multiple of 4. If it is not a multiple of 4, then = characters are appended until it is. A query string of the form ?name=value has problems when the value contains = charaters (some of them will be dropped, I don't recall the exact behavior). You may be able to get away with appending the right number of = characters before doing the base64 decode.

Edit 1

You may find that the value of UserNameToVerify has had "+"'s changed to " "'s so you may need to do something like so:

a = a.Replace(" ", "+");

This should get the length right;

int mod4 = a.Length % 4;
if (mod4 > 0 )
{
    a += new string('=', 4 - mod4);
}

Of course calling UrlEncode (as in LukeH's answer) should make this all moot.

Adding three months to a date in PHP

This answer is not exactly to this question. But I will add this since this question still searchable for how to add/deduct period from date.

$date = new DateTime('now');
$date->modify('+3 month'); // or you can use '-90 day' for deduct
$date = $date->format('Y-m-d h:i:s');
echo $date;

ASP.NET MVC passing an ID in an ActionLink to the controller

In MVC 4 you can link from one view to another controller passing the Id or Primary Key via

@Html.ActionLink("Select", "Create", "StudentApplication", new { id=item.PersonId }, null) 

jQuery - Getting form values for ajax POST

try as this code.

$.ajax({
        type: "POST",
        url: "http://rt.ja.com/includes/register.php?submit=1",
        data: "username="+username+"&email="+email+"&password="+password+"&passconf="+passconf,

        success: function(html)
        {   
            //alert(html);
            $('#userError').html(html);
            $("#userError").html(userChar);
            $("#userError").html(userTaken);
        }
    });

i think this will work definitely..

you can also use .serialize() function for sending data via jquery Ajax..

i.e: data : $("#registerSubmit").serialize()

Thanks.

WAMP error: Forbidden You don't have permission to access /phpmyadmin/ on this server

So all of these answers are basically the same one. They only address one idea: it has to be DNS related. Well, that is not the only part of this it turns out. After many changes, I was getting nowhere reading the next "same answer" hoping that it would just go my way.

What did the trick for me was to adjust my versions of Apache. I think what the deal was, is that the one of the configuration files get a path off or that the install due to IIS may have been messed up / or / or /etc. And so forcing a version change readdresses everything from your firewall to bad configurations.

In fact, when I switched back to Apache 2.4.2 it goes back to being a forbidden. And as soon as I go back to Apache 2.4.4 it comes back up. That rules out local network issues. I just wanted to point out that all of the answers here are the same and that I have been able to kill the forbidden by changing the Apache version.

Make a negative number positive

You want to wrap each number into Math.abs(). e.g.

System.out.println(Math.abs(-1));

prints out "1".

If you want to avoid writing the Math.-part, you can include the Math util statically. Just write

import static java.lang.Math.abs;

along with your imports, and you can refer to the abs()-function just by writing

System.out.println(abs(-1));

Getting the PublicKeyToken of .Net assemblies

1) The command is C:\Program Files\Microsoft SDKs\Windows\v6.0A\bin\sn -T {your.dll}

In the above example, the Microsoft SDK resides in C:\Program Files\Microsoft SDKs\Windows\v6.0A. Your environment may differ.

2) To get the public key token of any of your project, you can add sn.exe as part of your External Tools in Visual Studio. The steps are shown in this Microsoft link: How to: Create a Tool to Get the Public Key of an Assembly

How to make a 3-level collapsing menu in Bootstrap?

Bootstrap 3 dropped native support for nested collapsing menus, but there's a way to re-enable it with a 3rd party script. It's called SmartMenus. It means adding three new resources to your page, but it seamlessly supports Bootstrap 3.x with multiple levels of menus for nested <ul>/<li> elements with class="dropdown-menu". It automatically displays the proper caret indicator as well.

<head>
   ...
   <script src=".../jquery.smartmenus.min.js"></script>
   <script src=".../jquery.smartmenus.bootstrap.min.js"></script>
   ...
   <link rel="stylesheet" href=".../jquery.smartmenus.bootstrap.min.css"/>
   ...
</head>

Here's a demo page: http://vadikom.github.io/smartmenus/src/demo/bootstrap-navbar-fixed-top.html

Parsing JSON from XmlHttpRequest.responseJSON

I think you have to include jQuery to use responseJSON.

Without jQuery, you could try with responseText and try like eval("("+req.responseText+")");

UPDATE:Please read the comment regarding eval, you can test with eval, but don't use it in working extension.

OR

use json_parse : it does not use eval

PHP Connection failed: SQLSTATE[HY000] [2002] Connection refused

Using MAMP I changed the host=localhost to host=127.0.0.1. But a new issue came "connection refused"

Solved this by putting 'port' => '8889', in 'Datasources' => [

Git: See my last commit

By far the simplest command for this is:

git show --name-only

As it lists just the files in the last commit and doesn't give you the entire guts

An example of the output being:

commit  fkh889hiuhb069e44254b4925d2b580a602
Author: Kylo Ren <[email protected]>
Date:   Sat May 4 16:50:32 2168 -0700

Changed shield frequencies to prevent Millennium Falcon landing

 www/controllers/landing_ba_controller.js             
 www/controllers/landing_b_controller.js            
 www/controllers/landing_bp_controller.js          
 www/controllers/landing_h_controller.js          
 www/controllers/landing_w_controller.js  
 www/htdocs/robots.txt                        
 www/htdocs/templates/shields_FAQ.html       

Environment.GetFolderPath(...CommonApplicationData) is still returning "C:\Documents and Settings\" on Vista

Output on Windows 10

Fonts: C:\Windows\Fonts
CommonStartMenu: C:\ProgramData\Microsoft\Windows\Start Menu
CommonPrograms: C:\ProgramData\Microsoft\Windows\Start Menu\Programs
CommonStartup: C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup
CommonDesktopDirectory: C:\Users\Public\Desktop
CommonApplicationData: C:\ProgramData
Windows: C:\Windows
System: C:\Windows\system32
ProgramFiles: C:\Program Files (x86)
SystemX86: C:\Windows\SysWOW64
ProgramFilesX86: C:\Program Files (x86)
CommonProgramFiles: C:\Program Files (x86)\Common Files
CommonProgramFilesX86: C:\Program Files (x86)\Common Files
CommonTemplates: C:\ProgramData\Microsoft\Windows\Templates
CommonDocuments: C:\Users\Public\Documents
CommonAdminTools: C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Administrative Tools
CommonMusic: C:\Users\Public\Music
CommonPictures: C:\Users\Public\Pictures
CommonVideos: C:\Users\Public\Videos
Resources: C:\Windows\resources
LocalizedResources:
CommonOemLinks:

Code Snippet if you want to log your own

foreach(Environment.SpecialFolder f in Enum.GetValues(typeof(Environment.SpecialFolder)))
{
    string commonAppData = Environment.GetFolderPath(f);
    Console.WriteLine("{0}: {1}", f, commonAppData);
}
Console.ReadLine();

Select multiple columns by labels in pandas

Just pick the columns you want directly....

df[['A','E','I','C']]

How to remove single character from a String

To modify Strings, read about StringBuilder because it is mutable except for immutable String. Different operations can be found here https://docs.oracle.com/javase/tutorial/java/data/buffers.html. The code snippet below creates a StringBuilder and then append the given String and then delete the first character from the String and then convert it back from StringBuilder to a String.

StringBuilder sb = new StringBuilder();

sb.append(str);
sb.deleteCharAt(0);
str = sb.toString();

Difference between window.location.href, window.location.replace and window.location.assign

The part about not being able to use the Back button is a common misinterpretation. window.location.replace(URL) throws out the top ONE entry from the page history list, by overwriting it with the new entry, so the user can't easily go Back to that ONE particular webpage. The function does NOT wipe out the entire page history list, nor does it make the Back button completely non-functional.

(NO function nor combination of parameters that I know of can change or overwrite history list entries that you don't own absolutely for certain - browsers generally impelement this security limitation by simply not even defining any operation that might at all affect any entry other than the top one in the page history list. I shudder to think what sorts of dastardly things malware might do if such a function existed.)

If you really want to make the Back button non-functional (probably not "user friendly": think again if that's really what you want to do), "open" a brand new window. (You can "open" a popup that doesn't even have a "Back" button too ...but popups aren't very popular these days:-) If you want to keep your page showing no matter what the user does (again the "user friendliness" is questionable), set up a window.onunload handler that just reloads your page all over again clear from the very beginning every time.

How do you tell if caps lock is on using JavaScript?

In this below code it will be show alert when Caps lock on and they press key using shift.

if we return false; then current char will not append to text page.

$('#password').keypress(function(e) { 
    // e.keyCode is not work in FF, SO, it will
    // automatically get the value of e.which.  
    var s = String.fromCharCode( e.keyCode || e.which );
    if ( s.toUpperCase() === s && s.toLowerCase() !== s && !e.shiftKey ) {
            alert('caps is on');
            return false;
    }
else  if ( s.toUpperCase() !== s) {
            alert('caps is on and Shiftkey pressed');
            return false;
    }
});

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

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

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

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

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

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

Find the maximum value in a list of tuples in Python

Use max():

 
Using itemgetter():

In [53]: lis=[(101, 153), (255, 827), (361, 961)]

In [81]: from operator import itemgetter

In [82]: max(lis,key=itemgetter(1))[0]    #faster solution
Out[82]: 361

using lambda:

In [54]: max(lis,key=lambda item:item[1])
Out[54]: (361, 961)

In [55]: max(lis,key=lambda item:item[1])[0]
Out[55]: 361

timeit comparison:

In [30]: %timeit max(lis,key=itemgetter(1))
1000 loops, best of 3: 232 us per loop

In [31]: %timeit max(lis,key=lambda item:item[1])
1000 loops, best of 3: 556 us per loop

If hasClass then addClass to parent

You can't use $(this) since jQuery doesn't know what it is there. You seem to be overcomplicating things. You can do $('#content h1.aktiv').hide(). There's no reason to test to see if the class exists.

Populate a Drop down box from a mySQL table in PHP

At the top first set up database connection as follow:

<?php
$mysqli = new mysqli("localhost", "username", "password", "database") or die($this->mysqli->error);
$query= $mysqli->query("SELECT PcID from PC");
?> 

Then include the following code in HTML inside form

<select name="selected_pcid" id='selected_pcid'>

            <?php 

             while ($rows = $query->fetch_array(MYSQLI_ASSOC)) {
                        $value= $rows['id'];
                ?>
                 <option value="<?= $value?>"><?= $value?></option>
                <?php } ?>
             </select>

However, if you are using materialize css or any other out of the box css, make sure that select field is not hidden or disabled.

How to select only 1 row from oracle sql?

"FirstRow" Is a restriction and therefor it's place in the where clause not in the select clause. And it's called rownum

select * from dual where rownum = 1;

How to return value from Action()?

Use Func<T> rather than Action<T>.

Action<T> acts like a void method with parameter of type T, while Func<T> works like a function with no parameters and which returns an object of type T.

If you wish to give parameters to your function, use Func<TParameter1, TParameter2, ..., TReturn>.

Android Use Done button on Keyboard to click button

max.setOnKeyListener(new OnKeyListener(){
  @Override
  public boolean onKey(View v, int keyCode, KeyEvent event){
    if(keyCode == event.KEYCODE_ENTER){
        //do what you want
    }
  }
});

Angular 2 - innerHTML styling

update 2 ::slotted

::slotted is now supported by all new browsers and can be used with ViewEncapsulation.ShadowDom

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

update 1 ::ng-deep

/deep/ was deprecated and replaced by ::ng-deep.

::ng-deep is also already marked deprecated, but there is no replacement available yet.

When ViewEncapsulation.Native is properly supported by all browsers and supports styling accross shadow DOM boundaries, ::ng-deep will probably be discontinued.

original

Angular adds all kinds of CSS classes to the HTML it adds to the DOM to emulate shadow DOM CSS encapsulation to prevent styles of bleeding in and out of components. Angular also rewrites the CSS you add to match these added classes. For HTML added using [innerHTML] these classes are not added and the rewritten CSS doesn't match.

As a workaround try

  • for CSS added to the component
/* :host /deep/ mySelector { */
:host ::ng-deep mySelector { 
  background-color: blue;
}
  • for CSS added to index.html
/* body /deep/ mySelector { */
body ::ng-deep mySelector {
  background-color: green;
}

>>> (and the equivalent/deep/ but /deep/ works better with SASS) and ::shadow were added in 2.0.0-beta.10. They are similar to the shadow DOM CSS combinators (which are deprecated) and only work with encapsulation: ViewEncapsulation.Emulated which is the default in Angular2. They probably also work with ViewEncapsulation.None but are then only ignored because they are not necessary. These combinators are only an intermediate solution until more advanced features for cross-component styling is supported.

Another approach is to use

@Component({
  ...
  encapsulation: ViewEncapsulation.None,
})

for all components that block your CSS (depends on where you add the CSS and where the HTML is that you want to style - might be all components in your application)

Update

Example Plunker

Insert data through ajax into mysql database

I will tell you steps how you can insert data in ajax using PHP

AJAX Code

<script type="text/javascript">
function insertData() {
var student_name=$("#student_name").val();
var student_roll_no=$("#student_roll_no").val();
var student_class=$("#student_class").val();


// AJAX code to send data to php file.
    $.ajax({
        type: "POST",
        url: "insert-data.php",
        data: {student_name:student_name,student_roll_no:student_roll_no,student_class:s
         tudent_class},
        dataType: "JSON",
        success: function(data) {
         $("#message").html(data);
        $("p").addClass("alert alert-success");
        },
        error: function(err) {
        alert(err);
        }
    });

 }

</script>

PHP Code:

<?php

include('db.php');
$student_name=$_POST['student_name'];
$student_roll_no=$_POST['student_roll_no'];
$student_class=$_POST['student_class'];

$stmt = $DBcon->prepare("INSERT INTO 
student(student_name,student_roll_no,student_class) 
VALUES(:student_name, :student_roll_no,:student_class)");

 $stmt->bindparam(':student_name', $student_name);
 $stmt->bindparam(':student_roll_no', $student_roll_no);
 $stmt->bindparam(':student_class', $student_class);
 if($stmt->execute())
 {
  $res="Data Inserted Successfully:";
  echo json_encode($res);
  }
  else {
  $error="Not Inserted,Some Probelm occur.";
  echo json_encode($error);
  }



  ?>

You can customize it according to your needs. you can also check complete steps of AJAX Insert Data PHP

jquery ui Dialog: cannot call methods on dialog prior to initialization

If you cannot upgrade jQuery and you are getting:

Uncaught Error: cannot call methods on dialog prior to initialization; attempted to call method 'close'

You can work around it like so:

$(selector).closest('.ui-dialog-content').dialog('close');

Or if you control the view and know no other dialogs should be in use at all on the entire page, you could do:

$('.ui-dialog-content').dialog('close');

I would only recommend doing this if using closest causes a performance issue. There are likely other ways to work around it without doing a global close on all dialogs.

How to center text vertically with a large font-awesome icon?

I just had to do this myself, you need to do it the other way around.

  • do not play with the vertical-align of your text
  • play with the vertical align of the font-awesome icon
<div>
  <span class="icon icon-2x icon-camera" style=" vertical-align: middle;"></span>
  <span class="my-text">hello world</span>
</div>

Of course you could not use inline styles and target it with your own css class. But this works in a copy paste fashion.

See here: Vertical alignment of text and icon in button

If it were up to me however, I would not use the icon-2x. And simply specify the font-size myself, as in the following

<div class='my-fancy-container'>
    <span class='my-icon icon-file-text'></span>
    <span class='my-text'>Hello World</span>
</div>
.my-icon {
    vertical-align: middle;
    font-size: 40px;
}

.my-text {
    font-family: "Courier-new";
}

.my-fancy-container {
    border: 1px solid #ccc;
    border-radius: 6px;
    display: inline-block;
    margin: 60px;
    padding: 10px;
}

for a working example, please see JsFiddle

how to rename an index in a cluster?

You can use REINDEX to do that.

Reindex does not attempt to set up the destination index. It does not copy the settings of the source index. You should set up the destination index prior to running a _reindex action, including setting up mappings, shard counts, replicas, etc.

  1. First copy the index to a new name
POST /_reindex
{
  "source": {
    "index": "twitter"
  },
  "dest": {
    "index": "new_twitter"
  }
}
  1. Now delete the Index
DELETE /twitter

SQL, Postgres OIDs, What are they and why are they useful?

If you still use OID, it would be better to remove the dependency on it, because in recent versions of Postgres it is no longer supported. This can stop (temporarily until you solve it) your migration from version 10 to 12 for example.

See also: https://dev.to/rafaelbernard/postgresql-pgupgrade-from-10-to-12-566i

No Main class found in NetBeans

There could be a couple of things going wrong in this situation (assuming that you had code after your example and didn't just leave your code unbracketed).

First off, if you are running your entire project and not just the current file, make sure your project is the main project and the main class of the project is set to the correct file.

Otherwise, I have seen classmates with their code being fine but they still had this same problem. Sometimes, in Netbeans, a simple fix is to:

  1. Copy your current code (or back it up in a different location)
  2. Delete your current file
  3. Create a new main class in your project (you can name it the old one)
  4. Paste your code back in

If this doesn't work then try to clear the Netbeans cache, and if all else fails, then just do a clean un-installation and re-installation of Netbeans.

Set HTML element's style property in javascript

If you just want to change the color of the row, you could just access the style.backgroundColor property and set it.

Here is a quick link to a CSS property to JS conversion.

Location of the mongodb database on mac

The default data directory for MongoDB is /data/db.

This can be overridden by a dbpath option specified on the command line or in a configuration file.

If you install MongoDB via a package manager such as Homebrew or MacPorts these installs typically create a default data directory other than /data/db and set the dbpath in a configuration file.

If a dbpath was provided to mongod on startup you can check the value in the mongo shell:

db.serverCmdLineOpts()

You would see a value like:

"parsed" : {
    "dbpath" : "/usr/local/data"
},

Java converting Image to BufferedImage

If you use Kotlin, you can add an extension method to Image in the same manner Sri Harsha Chilakapati suggests.

fun Image.toBufferedImage(): BufferedImage {
    if (this is BufferedImage) {
        return this
    }
    val bufferedImage = BufferedImage(this.getWidth(null), this.getHeight(null), BufferedImage.TYPE_INT_ARGB)

    val graphics2D = bufferedImage.createGraphics()
    graphics2D.drawImage(this, 0, 0, null)
    graphics2D.dispose()

    return bufferedImage
}

And use it like this:

myImage.toBufferedImage()

How to select a value in dropdown javascript?

function setSelectedIndex(s, v) {
    for ( var i = 0; i < s.options.length; i++ ) {
        if ( s.options[i].value == v ) {
            s.options[i].selected = true;
            return;
        }
    }
}

Where s is the dropdown and v is the value

How to allow download of .json file with ASP.NET

Just had this issue but had to find the config for IIS Express so I could add the mime types. For me, it was located at C:\Users\<username>\Documents\IISExpress\config\applicationhost.config and I was able to add in the correct "mime map" there.

php REQUEST_URI

You can either use regex, or keep on using str_replace.

Eg.

$url = parse_url($_SERVER['REQUEST_URI']);

if ($url != '/') {
    parse_str($url['query']);
    echo $id;
    echo $othervar;
}

Output will be: http://www.testing.com/123/123

Making custom right-click context menus for my web-app

As Adrian said, the plugins are going to work the same way. There are three basic parts you're going to need:

1: Event handler for 'contextmenu' event:

$(document).bind("contextmenu", function(event) {
    event.preventDefault();
    $("<div class='custom-menu'>Custom menu</div>")
        .appendTo("body")
        .css({top: event.pageY + "px", left: event.pageX + "px"});
});

Here, you could bind the event handler to any selector that you want to show a menu for. I've chosen the entire document.

2: Event handler for 'click' event (to close the custom menu):

$(document).bind("click", function(event) {
    $("div.custom-menu").hide();
});

3: CSS to control the position of the menu:

.custom-menu {
    z-index:1000;
    position: absolute;
    background-color:#C0C0C0;
    border: 1px solid black;
    padding: 2px;
}

The important thing with the CSS is to include the z-index and position: absolute

It wouldn't be too tough to wrap all of this in a slick jQuery plugin.

You can see a simple demo here: http://jsfiddle.net/andrewwhitaker/fELma/

Replacing few values in a pandas dataframe column with another value

Just wanted to show that there is no performance difference between the 2 main ways of doing it:

df = pd.DataFrame(np.random.randint(0,10,size=(100, 4)), columns=list('ABCD'))

def loc():
    df1.loc[df1["A"] == 2] = 5
%timeit loc
19.9 ns ± 0.0873 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)


def replace():
    df2['A'].replace(
        to_replace=2,
        value=5,
        inplace=True
    )
%timeit replace
19.6 ns ± 0.509 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)

How to know the git username and email saved during configuration?

The command git config --list will list the settings. There you should also find user.name and user.email.

jasmine: Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL

What I did was: Added/Updated the following code:

framework: 'jasmine',
jasmineNodeOpts: 
{
    // Jasmine default timeout
    defaultTimeoutInterval: 60000,
    expectationResultHandler(passed, assertion) 
    {
      // do something
    },
}

How to keep a Python script output window open?

you can combine the answers before: (for Notepad++ User)

press F5 to run current script and type in command:

cmd /k python -i "$(FULL_CURRENT_PATH)"

in this way you stay in interactive mode after executing your Notepad++ python script and you are able to play around with your variables and so on :)

How to convert a boolean array to an int array

Numpy arrays have an astype method. Just do y.astype(int).

Note that it might not even be necessary to do this, depending on what you're using the array for. Bool will be autopromoted to int in many cases, so you can add it to int arrays without having to explicitly convert it:

>>> x
array([ True, False,  True], dtype=bool)
>>> x + [1, 2, 3]
array([2, 2, 4])

How to upload files in asp.net core?

 <form class="col-xs-12" method="post" action="/News/AddNews" enctype="multipart/form-data">

     <div class="form-group">
        <input type="file" class="form-control" name="image" />
     </div>

     <div class="form-group">
        <button type="submit" class="btn btn-primary col-xs-12">Add</button>
     </div>
  </form>

My Action Is

        [HttpPost]
        public IActionResult AddNews(IFormFile image)
        {
            Tbl_News tbl_News = new Tbl_News();
            if (image!=null)
            {

                //Set Key Name
                string ImageName= Guid.NewGuid().ToString() + Path.GetExtension(image.FileName);

                //Get url To Save
                string SavePath = Path.Combine(Directory.GetCurrentDirectory(),"wwwroot/img",ImageName);

                using(var stream=new FileStream(SavePath, FileMode.Create))
                {
                    image.CopyTo(stream);
                }
            }
            return View();
        }

How can I get key's value from dictionary in Swift?

For finding value use below

if let a = companies["AAPL"] {
   // a is the value
}

For traversing through the dictionary

for (key, value) in companies {
    print(key,"---", value)
}

Finally for searching key by value you firstly add the extension

extension Dictionary where Value: Equatable {
    func findKey(forValue val: Value) -> Key? {
        return first(where: { $1 == val })?.key
    }
}

Then just call

companies.findKey(val : "Apple Inc")

How should I use Outlook to send code snippets?

Here's what works for me, and is quickest and causes the least amount of pain / annoyance:

1) Paste you code snippet into sublime; make sure your syntax is looking good.

2) Right click and choose 'Copy as RTF'

3) Paste into your email

4) Done

MVC 4 @Scripts "does not exist"

One more for the pot - spent ages trying to work out the same problem - even though it was defined in the web.config for root and the root of Views. Turns out I'd mistakenly added it to the <system.web><pages><namespaces>, and not <system.web**.webPages.razor**><pages><namespaces> element.

Really easy to miss that!

Which websocket library to use with Node.js?

Update: This answer is outdated as newer versions of libraries mentioned are released since then.

Socket.IO v0.9 is outdated and a bit buggy, and Engine.IO is the interim successor. Socket.IO v1.0 (which will be released soon) will use Engine.IO and be much better than v0.9. I'd recommend you to use Engine.IO until Socket.IO v1.0 is released.

"ws" does not support fallback, so if the client browser does not support websockets, it won't work, unlike Socket.IO and Engine.IO which uses long-polling etc if websockets are not available. However, "ws" seems like the fastest library at the moment.

See my article comparing Socket.IO, Engine.IO and Primus: https://medium.com/p/b63bfca0539

How do I select a random value from an enumeration?

Here's an alternative version as an Extension Method using LINQ.

using System;
using System.Linq;

public static class EnumExtensions
{
    public static Enum GetRandomEnumValue(this Type t)
    {
        return Enum.GetValues(t)          // get values from Type provided
            .OfType<Enum>()               // casts to Enum
            .OrderBy(e => Guid.NewGuid()) // mess with order of results
            .FirstOrDefault();            // take first item in result
    }
}

public static class Program
{
    public enum SomeEnum
    {
        One = 1,
        Two = 2,
        Three = 3,
        Four = 4
    }

    public static void Main()
    {
        for(int i=0; i < 10; i++)
        {
            Console.WriteLine(typeof(SomeEnum).GetRandomEnumValue());
        }
    }           
}

Two
One
Four
Four
Four
Three
Two
Four
One
Three

class method generates "TypeError: ... got multiple values for keyword argument ..."

I want to add one more answer :

It happens when you try to pass positional parameter with wrong position order along with keyword argument in calling function.

there is difference between parameter and argument you can read in detail about here Arguments and Parameter in python

def hello(a,b=1, *args):
   print(a, b, *args)


hello(1, 2, 3, 4,a=12)

since we have three parameters :

a is positional parameter

b=1 is keyword and default parameter

*args is variable length parameter

so we first assign a as positional parameter , means we have to provide value to positional argument in its position order, here order matter. but we are passing argument 1 at the place of a in calling function and then we are also providing value to a , treating as keyword argument. now a have two values :

one is positional value: a=1

second is keyworded value which is a=12

Solution

We have to change hello(1, 2, 3, 4,a=12) to hello(1, 2, 3, 4,12) so now a will get only one positional value which is 1 and b will get value 2 and rest of values will get *args (variable length parameter)

additional information

if we want that *args should get 2,3,4 and a should get 1 and b should get 12

then we can do like this
def hello(a,*args,b=1): pass hello(1, 2, 3, 4,b=12)

Something more :

def hello(a,*c,b=1,**kwargs):
    print(b)
    print(c)
    print(a)
    print(kwargs)

hello(1,2,1,2,8,9,c=12)

output :

1

(2, 1, 2, 8, 9)

1

{'c': 12}

Angular 2: 404 error occur when I refresh through the browser

For people (like me) who really want PathLocationStrategy (i.e. html5Mode) instead of HashLocationStrategy, see How to: Configure your server to work with html5Mode from a third-party wiki:

When you have html5Mode enabled, the # character will no longer be used in your URLs. The # symbol is useful because it requires no server side configuration. Without #, the URL looks much nicer, but it also requires server side rewrites.

Here I only copy three examples from the wiki, in case the Wiki get lost. Other examples can be found by searching keyword "URL rewrite" (e.g. this answer for Firebase).

Apache

<VirtualHost *:80>
    ServerName my-app

    DocumentRoot /path/to/app

    <Directory /path/to/app>
        RewriteEngine on

        # Don't rewrite files or directories
        RewriteCond %{REQUEST_FILENAME} -f [OR]
        RewriteCond %{REQUEST_FILENAME} -d
        RewriteRule ^ - [L]

        # Rewrite everything else to index.html to allow HTML5 state links
        RewriteRule ^ index.html [L]
    </Directory>
</VirtualHost>

Documentation for rewrite module

nginx

server {
    server_name my-app;

    root /path/to/app;

    location / {
        try_files $uri $uri/ /index.html;
    }
}

Documentation for try_files

IIS

<system.webServer>
  <rewrite>
    <rules> 
      <rule name="Main Rule" stopProcessing="true">
        <match url=".*" />
        <conditions logicalGrouping="MatchAll">
          <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
          <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
        </conditions>
        <action type="Rewrite" url="/" />
      </rule>
    </rules>
  </rewrite>
</system.webServer>

fe_sendauth: no password supplied

Do not use passwords. Use peer authentication instead:

postgres://myuser@%2Fvar%2Frun%2Fpostgresql/mydb

Initializing ArrayList with some predefined values

If you just want to initialize outside of any method then use the initializer blocks :

import java.util.ArrayList;

public class Test {
private ArrayList<String> symbolsPresent = new ArrayList<String>();

// All you need is this block.
{
symbolsPresent = new ArrayList<String>();
symbolsPresent.add("ONE");
symbolsPresent.add("TWO");
symbolsPresent.add("THREE");
symbolsPresent.add("FOUR");
}


public ArrayList<String> getSymbolsPresent() {
    return symbolsPresent;
}

public void setSymbolsPresent(ArrayList<String> symbolsPresent) {
    this.symbolsPresent = symbolsPresent;
}

public static void main(String args[]) {    
    Test t = new Test();
    System.out.println("Symbols Present is" + t.symbolsPresent);

}    
}

How does the "view" method work in PyTorch?

weights.reshape(a, b) will return a new tensor with the same data as weights with size (a, b) as in it copies the data to another part of memory.

weights.resize_(a, b) returns the same tensor with a different shape. However, if the new shape results in fewer elements than the original tensor, some elements will be removed from the tensor (but not from memory). If the new shape results in more elements than the original tensor, new elements will be uninitialized in memory.

weights.view(a, b) will return a new tensor with the same data as weights with size (a, b)

Calculating text width

I found this solution works well and it inherits the origin font before sizing:

$.fn.textWidth = function(text){
  var org = $(this)
  var html = $('<span style="postion:absolute;width:auto;left:-9999px">' + (text || org.html()) + '</span>');
  if (!text) {
    html.css("font-family", org.css("font-family"));
    html.css("font-size", org.css("font-size"));
  }
  $('body').append(html);
  var width = html.width();
  html.remove();
  return width;
}

Connection string using Windows Authentication

Replace the username and password with Integrated Security=SSPI;

So the connection string should be

<connectionStrings> 
<add name="NorthwindContex" 
   connectionString="data source=localhost;
   initial catalog=northwind;persist security info=True; 
   Integrated Security=SSPI;" 
   providerName="System.Data.SqlClient" /> 
</connectionStrings> 

Django request.GET

since your form has a field called 'q', leaving it blank still sends an empty string.

try

if 'q' in request.GET and request.GET['q'] != "" :
     message
else
     error message

Set database timeout in Entity Framework

In the generated constructor code it should call OnContextCreated()

I added this partial class to solve the problem:

partial class MyContext: ObjectContext
{
    partial void OnContextCreated()
    {
        this.CommandTimeout = 300;
    }
}

Allowing Java to use an untrusted certificate for SSL/HTTPS connection

Here is some relevant code:

// Create a trust manager that does not validate certificate chains
TrustManager[] trustAllCerts = new TrustManager[]{
    new X509TrustManager() {
        public java.security.cert.X509Certificate[] getAcceptedIssuers() {
            return null;
        }
        public void checkClientTrusted(
            java.security.cert.X509Certificate[] certs, String authType) {
        }
        public void checkServerTrusted(
            java.security.cert.X509Certificate[] certs, String authType) {
        }
    }
};

// Install the all-trusting trust manager
try {
    SSLContext sc = SSLContext.getInstance("SSL");
    sc.init(null, trustAllCerts, new java.security.SecureRandom());
    HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
} catch (Exception e) {
}

// Now you can access an https URL without having the certificate in the truststore
try {
    URL url = new URL("https://hostname/index.html");
} catch (MalformedURLException e) {
}

This will completely disable SSL checking—just don't learn exception handling from such code!

To do what you want, you would have to implement a check in your TrustManager that prompts the user.

How do I remove objects from an array in Java?

You can use external library:

org.apache.commons.lang.ArrayUtils.remove(java.lang.Object[] array, int index)

It is in project Apache Commons Lang http://commons.apache.org/lang/

Where's my JSON data in my incoming Django request?

I had the same problem. I had been posting a complex JSON response, and I couldn't read my data using the request.POST dictionary.

My JSON POST data was:

//JavaScript code:
//Requires json2.js and jQuery.
var response = {data:[{"a":1, "b":2},{"a":2, "b":2}]}
json_response = JSON.stringify(response); // proper serialization method, read 
                                          // http://ejohn.org/blog/ecmascript-5-strict-mode-json-and-more/
$.post('url',json_response);

In this case you need to use method provided by aurealus. Read the request.body and deserialize it with the json stdlib.

#Django code:
import json
def save_data(request):
  if request.method == 'POST':
    json_data = json.loads(request.body) # request.raw_post_data w/ Django < 1.4
    try:
      data = json_data['data']
    except KeyError:
      HttpResponseServerError("Malformed data!")
    HttpResponse("Got json data")

Windows-1252 to UTF-8 encoding

How would you expect recode to know that a file is Windows-1252? In theory, I believe any file is a valid Windows-1252 file, as it maps every possible byte to a character.

Now there are certainly characteristics which would strongly suggest that it's UTF-8 - if it starts with the UTF-8 BOM, for example - but they wouldn't be definitive.

One option would be to detect whether it's actually a completely valid UTF-8 file first, I suppose... again, that would only be suggestive.

I'm not familiar with the recode tool itself, but you might want to see whether it's capable of recoding a file from and to the same encoding - if you do this with an invalid file (i.e. one which contains invalid UTF-8 byte sequences) it may well convert the invalid sequences into question marks or something similar. At that point you could detect that a file is valid UTF-8 by recoding it to UTF-8 and seeing whether the input and output are identical.

Alternatively, do this programmatically rather than using the recode utility - it would be quite straightforward in C#, for example.

Just to reiterate though: all of this is heuristic. If you really don't know the encoding of a file, nothing is going to tell you it with 100% accuracy.

Purpose of returning by const value?

It makes sure that the returned object (which is an RValue at that point) can't be modified. This makes sure the user can't do thinks like this:

myFunc() = Object(...);

That would work nicely if myFunc returned by reference, but is almost certainly a bug when returned by value (and probably won't be caught by the compiler). Of course in C++11 with its rvalues this convention doesn't make as much sense as it did earlier, since a const object can't be moved from, so this can have pretty heavy effects on performance.

Add ripple effect to my button with button background color?

In addition to Sudheesh R

Add Ripple Effect/Animation to a Android Button with button rectangle shape with corner

Create xml file res/drawable/your_file_name.xml

<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:color="@color/colorWhite"
    tools:targetApi="lollipop">
    <item android:id="@android:id/mask">
        <shape android:shape="rectangle">
            <solid android:color="@color/colorPrimaryDark" />
            <corners android:radius="50dp" />
        </shape>
    </item>

    <item android:id="@android:id/background">
        <shape android:shape="rectangle">
            <gradient
                android:angle="90"
                android:endColor="@color/colorAccent"
                android:startColor="@color/colorPrimary"
                android:type="linear" />
            <corners android:radius="50dp" />
        </shape>
    </item>
</ripple>

SQL Server JOIN missing NULL values

You can be explicit about the joins:

SELECT Table1.Col1, Table1.Col2, Table1.Col3, Table2.Col4
FROM Table1 INNER JOIN
     Table2
      ON (Table1.Col1 = Table2.Col1 or Table1.Col1 is NULL and Table2.Col1 is NULL) AND
         (Table1.Col2 = Table2.Col2 or Table1.Col2 is NULL and Table2.Col2 is NULL)

In practice, I would be more likely to use coalesce() in the join condition:

SELECT Table1.Col1, Table1.Col2, Table1.Col3, Table2.Col4
FROM Table1 INNER JOIN
     Table2
     ON (coalesce(Table1.Col1, '') = coalesce(Table2.Col1, '')) AND
        (coalesce(Table1.Col2, '') = coalesce(Table2.Col2, ''))

Where '' would be a value not in either of the tables.

Just a word of caution. In most databases, using any of these constructs prevents the use of indexes.

Checking if a string can be converted to float in Python

If you cared about performance (and I'm not suggesting you should), the try-based approach is the clear winner (compared with your partition-based approach or the regexp approach), as long as you don't expect a lot of invalid strings, in which case it's potentially slower (presumably due to the cost of exception handling).

Again, I'm not suggesting you care about performance, just giving you the data in case you're doing this 10 billion times a second, or something. Also, the partition-based code doesn't handle at least one valid string.

$ ./floatstr.py
F..
partition sad: 3.1102449894
partition happy: 2.09208488464
..
re sad: 7.76906108856
re happy: 7.09421992302
..
try sad: 12.1525540352
try happy: 1.44165301323
.
======================================================================
FAIL: test_partition (__main__.ConvertTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "./floatstr.py", line 48, in test_partition
    self.failUnless(is_float_partition("20e2"))
AssertionError

----------------------------------------------------------------------
Ran 8 tests in 33.670s

FAILED (failures=1)

Here's the code (Python 2.6, regexp taken from John Gietzen's answer):

def is_float_try(str):
    try:
        float(str)
        return True
    except ValueError:
        return False

import re
_float_regexp = re.compile(r"^[-+]?(?:\b[0-9]+(?:\.[0-9]*)?|\.[0-9]+\b)(?:[eE][-+]?[0-9]+\b)?$")
def is_float_re(str):
    return re.match(_float_regexp, str)


def is_float_partition(element):
    partition=element.partition('.')
    if (partition[0].isdigit() and partition[1]=='.' and partition[2].isdigit()) or (partition[0]=='' and partition[1]=='.' and pa\
rtition[2].isdigit()) or (partition[0].isdigit() and partition[1]=='.' and partition[2]==''):
        return True

if __name__ == '__main__':
    import unittest
    import timeit

    class ConvertTests(unittest.TestCase):
        def test_re(self):
            self.failUnless(is_float_re("20e2"))

        def test_try(self):
            self.failUnless(is_float_try("20e2"))

        def test_re_perf(self):
            print
            print 're sad:', timeit.Timer('floatstr.is_float_re("12.2x")', "import floatstr").timeit()
            print 're happy:', timeit.Timer('floatstr.is_float_re("12.2")', "import floatstr").timeit()

        def test_try_perf(self):
            print
            print 'try sad:', timeit.Timer('floatstr.is_float_try("12.2x")', "import floatstr").timeit()
            print 'try happy:', timeit.Timer('floatstr.is_float_try("12.2")', "import floatstr").timeit()

        def test_partition_perf(self):
            print
            print 'partition sad:', timeit.Timer('floatstr.is_float_partition("12.2x")', "import floatstr").timeit()
            print 'partition happy:', timeit.Timer('floatstr.is_float_partition("12.2")', "import floatstr").timeit()

        def test_partition(self):
            self.failUnless(is_float_partition("20e2"))

        def test_partition2(self):
            self.failUnless(is_float_partition(".2"))

        def test_partition3(self):
            self.failIf(is_float_partition("1234x.2"))

    unittest.main()

What are good grep tools for Windows?

If none of the solulutions is quite what you are looking for, perhaps you could write a wrapper to FindStr that does exactly what you require?

FindStr is pretty good anyway so it should just be knocking a GUI up (if you want it) and providing a few extra features (like combining it with Find to find the count of files which contain a specified string [mentioned above]).

This, of course, assumes you have the requirement, time and inclination to do this!

Replace Fragment inside a ViewPager

after research i found solution with short code. first of all create a public instance on fragment and just remove your fragment on onSaveInstanceState if fragment not recreating on orientation change.

 @Override
public void onSaveInstanceState(Bundle outState) {
    if (null != mCalFragment) {
        FragmentTransaction bt = getChildFragmentManager().beginTransaction();
        bt.remove(mFragment);
        bt.commit();
    }
    super.onSaveInstanceState(outState);
}

How to keep Docker container running after starting services?

I just had the same problem and I found out that if you are running your container with the -t and -d flag, it keeps running.

docker run -td <image>

Here is what the flags do (according to docker run --help):

-d, --detach=false         Run container in background and print container ID
-t, --tty=false            Allocate a pseudo-TTY

The most important one is the -t flag. -d just lets you run the container in the background.

Append date to filename in linux

You can use backticks.

$ echo myfilename-"`date +"%d-%m-%Y"`"

Yields:

myfilename-25-11-2009

link with target="_blank" does not open in new tab in Chrome

Your syntax for the target attribute is correct, but browsers need not honor it. They may interpret it as opening the destination in a new tab rather than new window, or they may completely ignore the attribute. Browsers have settings for such issues. Moreover, opening of new windows may be prevented by browser plugins (typically designed to prevent annoying advertisements).

There’s little you can do about this as an author. You might consider opening a new window with JavaScript instead, cf. to the accepted answer to target="_blank" is not working in firefox?, but browsers may be even more reluctant to let pages open new windows that way than via target.

target="_blank" is not working in firefox?

Check/Uncheck a checkbox on datagridview

Here is another example you can try

private void dataGridView_CellContentClick(object sender, DataGridViewCellEventArgs e)
    {
        if (e.ColumnIndex == dataGridView.Columns["Select"].Index)
        {
            dataGridView.EndEdit();

            if ((bool)dataGridView.Rows[e.RowIndex].Cells["Select"].Value)
            {
                //-- checking current select, needs to uncheck any other cells that are checked
                foreach(DataGridViewRow row in dataGridView.Rows)
                {
                    if (row.Index == e.RowIndex)
                    {
                        dataGridView.Rows[row.Index].SetValues(true);
                    }
                    else
                    {
                        dataGridView.Rows[row.Index].SetValues(false);
                    }
                }
            }
        }
    }

How to sort pandas data frame using values from several columns?

In my case, the accepted answer didn't work:

f.sort_values(by=["c1","c2"], ascending=[False, True])

Only the following worked as expected:

f = f.sort_values(by=["c1","c2"], ascending=[False, True])

HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))

This could also be an issue of building the code using a 64 bit configuration. You can try to select x86 as the build platform which can solve this issue. To do this right-click the solution and select Configuration Manager From there you can change the Platform of the project using the 32-bit .dll to x86

Exit while loop by user hitting ENTER key

Here is the best and simplest answer. Use try and except calls.

x = randint(1,9)
guess = -1

print "Guess the number below 10:"
while guess != x:
    try:
        guess = int(raw_input("Guess: "))

        if guess < x:
            print "Guess higher."
        elif guess > x:
            print "Guess lower."
        else:
            print "Correct."
    except:
        print "You did not put any number."

JavaScript Infinitely Looping slideshow with delays?

You can infinitely loop easily enough via recursion.

function it_keeps_going_and_going_and_going() {
  it_keeps_going_and_going_and_going();
}

it_keeps_going_and_going_and_going()

Best way to find os name and version in Unix/Linux platform

I prepared following commands to find concise information about a Linux system:

clear
echo "\n----------OS Information------------"
hostnamectl | grep "Static hostname:"
hostnamectl | tail -n 3
echo "\n----------Memory Information------------"
cat /proc/meminfo | grep MemTotal
echo "\n----------CPU Information------------"
echo -n "Number of core(s): "
cat /proc/cpuinfo | grep "processor" | wc -l
cat /proc/cpuinfo | grep "model name" | head -n 1
echo "\n----------Disk Information------------"
echo -n "Total Size: "
df -h --total | tail -n 1| awk '{print $2}'
echo -n "Used: "
df -h --total | tail -n 1| awk '{print $3}'
echo -n "Available: "
df -h --total | tail -n 1| awk '{print $4}'
echo "\n-------------------------------------\n"

Copy and paste in an sh file like info.sh and then run it using command sh info.sh

C library function to perform sort

While not in the standard library exactly, https://github.com/swenson/sort has just two header files you can include to get access to a wide range of incredibly fast sorting routings, like so:

#define SORT_NAME int64
#define SORT_TYPE int64_t
#define SORT_CMP(x, y) ((x) - (y))
#include "sort.h"
/* You now have access to int64_quick_sort, int64_tim_sort, etc., e.g., */
int64_quick_sort(arr, 128); /* Assumes you have some int *arr or int arr[128]; */

This should be at least twice as fast as the standard library qsort, since it doesn't use function pointers, and has many other sorting algorithm options to choose from.

It's in C89, so should work in basically every C compiler.

What does "#include <iostream>" do?

In order to read or write to the standard input/output streams you need to include it.

int main( int argc, char * argv[] )
{
    std::cout << "Hello World!" << std::endl;
    return 0;
}

That program will not compile unless you add #include <iostream>

The second line isn't necessary

using namespace std;

What that does is tell the compiler that symbol names defined in the std namespace are to be brought into your program's scope, so you can omit the namespace qualifier, and write for example

#include <iostream>
using namespace std;
int main( int argc, char * argv[] )
{
    cout << "Hello World!" << endl;
    return 0;
}

Notice you no longer need to refer to the output stream with the fully qualified name std::cout and can use the shorter name cout.

I personally don't like bringing in all symbols in the namespace of a header file... I'll individually select the symbols I want to be shorter... so I would do this:

#include <iostream>
using std::cout;
using std::endl;

int main( int argc, char * argv[] )
{
    cout << "Hello World!" << endl;
    return 0;
}

But that is a matter of personal preference.

set the width of select2 input (through Angular-ui directive)

You can try like this. It works for me

$("#MISSION_ID").select2();

On hide/show or ajax request, we have to reinitialize the select2 plugin

For example:

$("#offialNumberArea").show();
$("#eventNameArea").hide();

$('.selectCriteria').change(function(){
    var thisVal = $(this).val();
    if(thisVal == 'sailor'){
        $("#offialNumberArea").show();
        $("#eventNameArea").hide();
    }
    else
    {
        $("#offialNumberArea").hide();
        $("#eventNameArea").show();
        $("#MISSION_ID").select2();
    }
});

CSS background image to fit width, height should auto-scale in proportion

body{
    background-image: url(../url/imageName.jpg);
    background-attachment: fixed;
    background-size: auto 100%;
    background-position: center;
}

How can I temporarily disable a foreign key constraint in MySQL?

A very simple solution with phpMyAdmin:

  • In your table, go to the SQL tab
  • After you edit the SQL command that you want to run, there is a check box next to GO, named 'Enable foreign key checks' .
  • Uncheck this check box and run your SQL. It will be automatically rechecked after executing.

Javascript switch vs. if...else if...else

Is there a preformance difference in Javascript between a switch statement and an if...else if....else?

I don't think so, switch is useful/short if you want prevent multiple if-else conditions.

Is the behavior of switch and if...else if...else different across browsers? (FireFox, IE, Chrome, Opera, Safari)

Behavior is same across all browsers :)

Disable future dates after today in Jquery Ui Datepicker

maxDate: new Date() 

its working fine for me disable with current date in date range picker

Why are Python lambdas useful?

Pretty much anything you can do with lambda you can do better with either named functions or list and generator expressions.

Consequently, for the most part you should just one of those in basically any situation (except maybe for scratch code written in the interactive interpreter).

What is SaaS, PaaS and IaaS? With examples

SaaS: Software as a Service Cloud application services or “Software as a Service” (SaaS) are probably the most popular form of cloud computing and are easy to use. SaaS uses the Web to deliver applications that are managed by a third-party vendor and whose interface is accessed on the clients’ side. Most SaaS applications can be run directly from a Web browser, without any downloads or installations required. SaaS eliminates the need to install and run applications on individual computers. With SaaS, it’s easy for enterprises to streamline their maintenance and support, because everything can be managed by vendors: applications, runtime, data, middleware, O/S, virtualization, servers, storage, and networking. Gmail is one famous example of an SaaS mail provider.

PaaS: Platform as a Service The most complex of the three, cloud platform services or “Platform as a Service” (PaaS) deliver computational resources through a platform. What developers gain with PaaS is a framework they can build upon to develop or customize applications. PaaS makes the development, testing, and deployment of applications quick, simple, and cost-effective, eliminating the need to buy the underlying layers of hardware and software. One comparison between SaaS vs. PaaS has to do with what aspects must be managed by users, rather than providers: With PaaS, vendors still manage runtime, middleware, O/S, virtualization, servers, storage, and networking, but users manage applications and data.

IaaS: Infrastructure as a Service Cloud infrastructure services, known as “Infrastructure as a Service” (IaaS), deliver computer infrastructure (such as a platform virtualization environment), storage, and networking. Instead of having to purchase software, servers, or network equipment, users can buy these as a fully outsourced service that is usually billed according to the amount of resources consumed. Basically, in exchange for a rental fee, a third party allows you to install a virtual server on their IT infrastructure. Compared to SaaS and PaaS, IaaS users are responsible for managing more: applications, data, runtime, middleware, and O/S. Vendors still manage virtualization, servers, hard drives, storage, and networking. What users gain with IaaS is infrastructure on top of which they can install any required platforms. Users are responsible for updating these if new versions are released.

How to send email from localhost WAMP Server to send email Gmail Hotmail or so forth?

a) Open the "php.ini". For XAMPP,it is located in C:\XAMPP\php\php.ini. Find out if you are using WAMP or LAMP server. Note : Make a backup of php.ini file 

b) Search [mail function] in the php.ini file. 

You can find like below.
[mail function]
; For Win32 only.
; http://php.net/smtp
SMTP = localhost
; http://php.net/smtp-port
smtp_port = 25


; For Win32 only.
; http://php.net/sendmail-from
;sendmail_from = postmaster@localhost


Change the localhost to the smtp server name of your ISP. No need to change the smtp_port. Leave it as 25. Change sendmail_from from postmaster@localhost to your domain email address which will be used as from address.. 

So for me, it will become like this.
[mail function]
; For Win32 only.
SMTP = smtp.planetghost.com
smtp_port = 25
; For Win32 only.
sendmail_from = [email protected]
auth_username = [email protected]
auth_password = example_password


c) Restart the XAMPP or WAMP(apache server) so that changes will start working.

d) Now try to send the mail using the mail() function , 

mail("[email protected]","Success","Great, Localhost Mail works");

credit

================================================================================

Another way

Gmail servers use SMTP Authentication under SSL. I think that there is no way to use the mail() function under that circumstances, so you might want to check these alternatives:

  1. PEAR: Mail
  2. phpMailer

They both support SMTP auth under SSL.

Credit : Check reference answer here

Is it better to use "is" or "==" for number comparison in Python?

Others have answered your question, but I'll go into a little bit more detail:

Python's is compares identity - it asks the question "is this one thing actually the same object as this other thing" (similar to == in Java). So, there are some times when using is makes sense - the most common one being checking for None. Eg, foo is None. But, in general, it isn't what you want.

==, on the other hand, asks the question "is this one thing logically equivalent to this other thing". For example:

>>> [1, 2, 3] == [1, 2, 3]
True
>>> [1, 2, 3] is [1, 2, 3]
False

And this is true because classes can define the method they use to test for equality:

>>> class AlwaysEqual(object):
...     def __eq__(self, other):
...         return True
...
>>> always_equal = AlwaysEqual()
>>> always_equal == 42
True
>>> always_equal == None
True

But they cannot define the method used for testing identity (ie, they can't override is).

What is the difference between a stored procedure and a view?

@Patrick is correct with what he said, but to answer your other questions a View will create itself in Memory, and depending on the type of Joins, Data and if there is any aggregation done, it could be a quite memory hungry View.

Stored procedures do all their processing either using Temp Hash Table e.g #tmpTable1 or in memory using @tmpTable1. Depending on what you want to tell it to do.

A Stored Procedure is like a Function, but is called Directly by its name. instead of Functions which are actually used inside a query itself.

Obviously most of the time Memory tables are faster, if you are not retrieveing alot of data.

How do I sort a list of datetime or date objects?

You're getting None because list.sort() it operates in-place, meaning that it doesn't return anything, but modifies the list itself. You only need to call a.sort() without assigning it to a again.

There is a built in function sorted(), which returns a sorted version of the list - a = sorted(a) will do what you want as well.

How to create a video from images with FFmpeg?

-pattern_type glob

This great option makes it easier to select the images in many cases.

Slideshow video with one image per second

ffmpeg -framerate 1 -pattern_type glob -i '*.png' \
  -c:v libx264 -r 30 -pix_fmt yuv420p out.mp4

Add some music to it, cutoff when the presumably longer audio when the images end:

ffmpeg -framerate 1 -pattern_type glob -i '*.png' -i audio.ogg \
  -c:a copy -shortest -c:v libx264 -r 30 -pix_fmt yuv420p out.mp4

Here are two demos on YouTube:

Be a hippie and use the Theora patent-unencumbered video format:

ffmpeg -framerate 1 -pattern_type glob -i '*.png' -i audio.ogg \
  -c:a copy -shortest -c:v libtheora -r 30 -pix_fmt yuv420p out.ogg

Your images should of course be sorted alphabetically, typically as:

0001-first-thing.jpg
0002-second-thing.jpg
0003-and-third.jpg

and so on.

I would also first ensure that all images to be used have the same aspect ratio, possibly by cropping them with imagemagick or nomacs beforehand, so that ffmpeg will not have to make hard decisions. In particular, the width has to be divisible by 2, otherwise conversion fails with: "width not divisible by 2".

Normal speed video with one image per frame at 30 FPS

ffmpeg -framerate 30 -pattern_type glob -i '*.png' \
  -c:v libx264 -pix_fmt yuv420p out.mp4

Here's what it looks like:

GIF generated with: https://askubuntu.com/questions/648603/how-to-create-an-animated-gif-from-mp4-video-via-command-line/837574#837574

Add some audio to it:

ffmpeg -framerate 30 -pattern_type glob -i '*.png' \
  -i audio.ogg -c:a copy -shortest -c:v libx264 -pix_fmt yuv420p out.mp4

Result: https://www.youtube.com/watch?v=HG7c7lldhM4

These are the test media I've used:a

wget -O opengl-rotating-triangle.zip https://github.com/cirosantilli/media/blob/master/opengl-rotating-triangle.zip?raw=true
unzip opengl-rotating-triangle.zip
cd opengl-rotating-triangle
wget -O audio.ogg https://upload.wikimedia.org/wikipedia/commons/7/74/Alnitaque_%26_Moon_Shot_-_EURO_%28Extended_Mix%29.ogg

Images generated with: How to use GLUT/OpenGL to render to a file?

It is cool to observe how much the video compresses the image sequence way better than ZIP as it is able to compress across frames with specialized algorithms:

  • opengl-rotating-triangle.mp4: 340K
  • opengl-rotating-triangle.zip: 7.3M

Convert one music file to a video with a fixed image for YouTube upload

Answered at: https://superuser.com/questions/700419/how-to-convert-mp3-to-youtube-allowed-video-format/1472572#1472572

Full realistic slideshow case study setup step by step

There's a bit more to creating slideshows than running a single ffmpeg command, so here goes a more interesting detailed example inspired by this timeline.

Get the input media:

mkdir -p orig
cd orig
wget -O 1.png https://upload.wikimedia.org/wikipedia/commons/2/22/Australopithecus_afarensis.png
wget -O 2.jpg https://upload.wikimedia.org/wikipedia/commons/6/61/Homo_habilis-2.JPG
wget -O 3.jpg https://upload.wikimedia.org/wikipedia/commons/c/cb/Homo_erectus_new.JPG
wget -O 4.png https://upload.wikimedia.org/wikipedia/commons/1/1f/Homo_heidelbergensis_-_forensic_facial_reconstruction-crop.png
wget -O 5.jpg https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Sabaa_Nissan_Militiaman.jpg/450px-Sabaa_Nissan_Militiaman.jpg
wget -O audio.ogg https://upload.wikimedia.org/wikipedia/commons/7/74/Alnitaque_%26_Moon_Shot_-_EURO_%28Extended_Mix%29.ogg
cd ..

# Convert all to PNG for consistency.
# https://unix.stackexchange.com/questions/29869/converting-multiple-image-files-from-jpeg-to-pdf-format
# Hardlink the ones that are already PNG.
mkdir -p png
mogrify -format png -path png orig/*.jpg
ln -P orig/*.png png

Now we have a quick look at all image sizes to decide on the final aspect ratio:

identify png/*

which outputs:

png/1.png PNG 557x495 557x495+0+0 8-bit sRGB 653KB 0.000u 0:00.000
png/2.png PNG 664x800 664x800+0+0 8-bit sRGB 853KB 0.000u 0:00.000
png/3.png PNG 544x680 544x680+0+0 8-bit sRGB 442KB 0.000u 0:00.000
png/4.png PNG 207x238 207x238+0+0 8-bit sRGB 76.8KB 0.000u 0:00.000
png/5.png PNG 450x600 450x600+0+0 8-bit sRGB 627KB 0.000u 0:00.000

so the classic 480p (640x480 == 4/3) aspect ratio seems appropriate.

Do one conversion with minimal resizing to make widths even (TODO automate for any width, here I just manually looked at identify output and reduced width and height by one):

mkdir -p raw
convert png/1.png -resize 556x494 raw/1.png
ln -P png/2.png png/3.png png/4.png png/5.png raw
ffmpeg -framerate 1 -pattern_type glob -i 'raw/*.png' -i orig/audio.ogg -c:v libx264 -c:a copy -shortest -r 30 -pix_fmt yuv420p raw.mp4

This produces terrible output, because as seen from:

ffprobe raw.mp4

ffmpeg just takes the size of the first image, 556x494, and then converts all others to that exact size, breaking their aspect ratio.

Now let's convert the images to the target 480p aspect ratio automatically by cropping as per ImageMagick: how to minimally crop an image to a certain aspect ratio?

mkdir -p auto
mogrify -path auto -geometry 640x480^ -gravity center -crop 640x480+0+0 png/*.png
ffmpeg -framerate 1 -pattern_type glob -i 'auto/*.png' -i orig/audio.ogg -c:v libx264 -c:a copy -shortest -r 30 -pix_fmt yuv420p auto.mp4

So now, the aspect ratio is good, but inevitably some cropping had to be done, which kind of cut up interesting parts of the images.

The other option is to pad with black background to have the same aspect ratio as shown at: Resize to fit in a box and set background to black on "empty" part

mkdir -p black
ffmpeg -framerate 1 -pattern_type glob -i 'black/*.png' -i orig/audio.ogg -c:v libx264 -c:a copy -shortest -r 30 -pix_fmt yuv420p black.mp4

Generally speaking though, you will ideally be able to select images with the same or similar aspect ratios to avoid those problems in the first place.

About the CLI options

Note however that despite the name, -glob this is not as general as shell Glob patters, e.g.: -i '*' fails: https://trac.ffmpeg.org/ticket/3620 (apparently because filetype is deduced from extension).

-r 30 makes the -framerate 1 video 30 FPS to overcome bugs in players like VLC for low framerates: VLC freezes for low 1 FPS video created from images with ffmpeg Therefore it repeats each frame 30 times to keep the desired 1 image per second effect.

Next steps

You will also want to:

TODO: learn to cut and concatenate multiple audio files into the video without intermediate files, I'm pretty sure it's possible:

Tested on

ffmpeg 3.4.4, vlc 3.0.3, Ubuntu 18.04.

Bibliography

Difference between "this" and"super" keywords in Java

super() & this()

  • super() - to call parent class constructor.
  • this() - to call same class constructor.

NOTE:

  • We can use super() and this() only in constructor not anywhere else, any attempt to do so will lead to compile-time error.

  • We have to keep either super() or this() as the first line of the constructor but NOT both simultaneously.

super & this keyword

  • super - to call parent class members(variables and methods).
  • this - to call same class members(variables and methods).

NOTE: We can use both of them anywhere in a class except static areas(static block or method), any attempt to do so will lead to compile-time error.

How to use basic authorization in PHP curl

Try the following code :

$username='ABC';
$password='XYZ';
$URL='<URL>';

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$URL);
curl_setopt($ch, CURLOPT_TIMEOUT, 30); //timeout after 30 seconds
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
curl_setopt($ch, CURLOPT_USERPWD, "$username:$password");
$result=curl_exec ($ch);
$status_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);   //get status code
curl_close ($ch);

Moment.js transform to date object

I needed to have timezone information in my date string. I was originally using moment.tz(dateStr, 'America/New_York').toString(); but then I started getting errors about feeding that string back into moment.

I tried the moment.tz(dateStr, 'America/New_York').toDate(); but then I lost timezone information which I needed.

The only solution that returned a usable date string with timezone that could be fed back into moment was moment.tz(dateStr, 'America/New_York').format();

Add views below toolbar in CoordinatorLayout

Take the attribute

app:layout_behavior="@string/appbar_scrolling_view_behavior"

off the RecyclerView and put it on the FrameLayout that you are trying to show under the Toolbar.

I've found that one important thing the scrolling view behavior does is to layout the component below the toolbar. Because the FrameLayout has a descendant that will scroll (RecyclerView), the CoordinatorLayout will get those scrolling events for moving the Toolbar.


One other thing to be aware of: That layout behavior will cause the FrameLayout height to be sized as if the Toolbar is already scrolled, and with the Toolbar fully displayed the entire view is simply pushed down so that the bottom of the view is below the bottom of the CoordinatorLayout.

This was a surprise to me. I was expecting the view to be dynamically resized as the toolbar is scrolled up and down. So if you have a scrolling component with a fixed component at the bottom of your view, you won't see that bottom component until you have fully scrolled the Toolbar.

So when I wanted to anchor a button at the bottom of the UI, I worked around this by putting the button at the bottom of the CoordinatorLayout (android:layout_gravity="bottom") and adding a bottom margin equal to the button's height to the view beneath the toolbar.

adb devices command not working

I just got the same situation, Factory data reset worked well for me.

Is there an advantage to use a Synchronized Method instead of a Synchronized Block?

Most often I use this to synchronize access to a list or map but I don't want to block access to all methods of the object.

In the following code one thread modifying the list will not block waiting for a thread that is modifying the map. If the methods were synchronized on the object then each method would have to wait even though the modifications they are making would not conflict.

private List<Foo> myList = new ArrayList<Foo>();
private Map<String,Bar) myMap = new HashMap<String,Bar>();

public void put( String s, Bar b ) {
  synchronized( myMap ) {
    myMap.put( s,b );
    // then some thing that may take a while like a database access or RPC or notifying listeners
  }
}

public void hasKey( String s, ) {
  synchronized( myMap ) {
    myMap.hasKey( s );
  }
}

public void add( Foo f ) {
  synchronized( myList ) {
    myList.add( f );
// then some thing that may take a while like a database access or RPC or notifying listeners
  }
}

public Thing getMedianFoo() {
  Foo med = null;
  synchronized( myList ) {
    Collections.sort(myList);
    med = myList.get(myList.size()/2); 
  }
  return med;
}

Does C have a string type?

C does not and never has had a native string type. By convention, the language uses arrays of char terminated with a null char, i.e., with '\0'. Functions and macros in the language's standard libraries provide support for the null-terminated character arrays, e.g., strlen iterates over an array of char until it encounters a '\0' character and strcpy copies from the source string until it encounters a '\0'.

The use of null-terminated strings in C reflects the fact that C was intended to be only a little more high-level than assembly language. Zero-terminated strings were already directly supported at that time in assembly language for the PDP-10 and PDP-11.

It is worth noting that this property of C strings leads to quite a few nasty buffer overrun bugs, including serious security flaws. For example, if you forget to null-terminate a character string passed as the source argument to strcpy, the function will keep copying sequential bytes from whatever happens to be in memory past the end of the source string until it happens to encounter a 0, potentially overwriting whatever valuable information follows the destination string's location in memory.

In your code example, the string literal "Hello, world!" will be compiled into a 14-byte long array of char. The first 13 bytes will hold the letters, comma, space, and exclamation mark and the final byte will hold the null-terminator character '\0', automatically added for you by the compiler. If you were to access the array's last element, you would find it equal to 0. E.g.:

const char foo[] = "Hello, world!";
assert(foo[12] == '!');
assert(foo[13] == '\0');

However, in your example, message is only 10 bytes long. strcpy is going to write all 14 bytes, including the null-terminator, into memory starting at the address of message. The first 10 bytes will be written into the memory allocated on the stack for message and the remaining four bytes will simply be written on to the end of the stack. The consequence of writing those four extra bytes onto the stack is hard to predict in this case (in this simple example, it might not hurt a thing), but in real-world code it usually leads to corrupted data or memory access violation errors.

What is the connection string for localdb for version 11

1) Requires .NET framework 4 updated to at least 4.0.2. If you have 4.0.2, then you should have

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30319\SKUs\.NETFramework,Version=v4.0.2

If you have installed latest VS 2012 chances are that you already have 4.0.2. Just verify first.

2) Next you need to have an instance of LocalDb. By default you have an instance whose name is a single v character followed by the LocalDB release version number in the format xx.x. For example, v11.0 represents SQL Server 2012. Automatic instances are public by default. You can also have named instances which are private. Named instances provide isolation from other instances and can improve performance by reducing resource contention with other database users. You can check the status of instances using the SqlLocalDb.exe utility (run it from command line).

3) Next your connection string should look like:

"Server=(localdb)\\v11.0;Integrated Security=true;"

or

"Data Source=(localdb)\\test;Integrated Security=true;"

from your code. They both are the same. Notice the two \\ required because \v and \t means special characters. Also note that what appears after (localdb)\\ is the name of your LocalDb instance. v11.0 is the default public instance, test is something I have created manually which is private.

  1. If you have a database (.mdf file) already:

    "Server=(localdb)\\Test;Integrated Security=true;AttachDbFileName= myDbFile;"
    
  2. If you don't have a Sql Server database:

    "Server=(localdb)\\v11.0;Integrated Security=true;"
    

And you can create your own database programmatically:

a) to save it in the default location with default setting:

var query = "CREATE DATABASE myDbName;";

b) To save it in a specific location with your own custom settings:

// your db name
string dbName = "myDbName";

// path to your db files:
// ensure that the directory exists and you have read write permission.
string[] files = { Path.Combine(Application.StartupPath, dbName + ".mdf"), 
                   Path.Combine(Application.StartupPath, dbName + ".ldf") };

// db creation query:
// note that the data file and log file have different logical names
var query = "CREATE DATABASE " + dbName +
    " ON PRIMARY" +
    " (NAME = " + dbName + "_data," +
    " FILENAME = '" + files[0] + "'," +
    " SIZE = 3MB," +
    " MAXSIZE = 10MB," +
    " FILEGROWTH = 10%)" +

    " LOG ON" +
    " (NAME = " + dbName + "_log," +
    " FILENAME = '" + files[1] + "'," +
    " SIZE = 1MB," +
    " MAXSIZE = 5MB," +
    " FILEGROWTH = 10%)" +
    ";";

And execute!

A sample table can be loaded into the database with something like:

 @"CREATE TABLE supportContacts 
    (
        id int identity primary key, 
        type varchar(20), 
        details varchar(30)
    );
   INSERT INTO supportContacts
   (type, details)
   VALUES
   ('Email', '[email protected]'),
   ('Twitter', '@sqlfiddle');";

Note that SqlLocalDb.exe utility doesnt give you access to databases, you separately need sqlcmd utility which is sad..

EDIT: moved position of semicolon otherwise error would occur if code was copy/pasted

Remove a character at a certain position in a string - javascript

    var str = 'Hello World';
                str = setCharAt(str, 3, '');
                alert(str);

function setCharAt(str, index, chr)
        {
            if (index > str.length - 1) return str;
            return str.substr(0, index) + chr + str.substr(index + 1);
        }

How to set 24-hours format for date on java?

This will give you the date in 24 hour format.

    Date date = new Date();
    date.setHours(date.getHours() + 8);
    System.out.println(date);
    SimpleDateFormat simpDate;
    simpDate = new SimpleDateFormat("kk:mm:ss");
    System.out.println(simpDate.format(date));

How to determine the version of android SDK installed in computer?

I develope cross-plateform mobile applications Using Xamarin integrated in Visual Studio 2017.

I prefer to install and check all details of Android SDK from within the Visual Studio 2017. This can be found under the menu TOOLS -> Android -> Android SDK Manager.

Bellow is the Visual representation of the Adroid SDK Manager.enter image description here

jQuery: set selected value of dropdown list?

You can select dropdown option value by name

jQuery("#option_id").find("option:contains('Monday')").each(function()
{
 if( jQuery(this).text() == 'Monday' )
 {
  jQuery(this).attr("selected","selected");
  }
});

Reading a column from CSV file using JAVA

If you are using Java 7+, you may want to use NIO.2, e.g.:

Code:

public static void main(String[] args) throws Exception {

    File file = new File("test.csv");

    List<String> lines = Files.readAllLines(file.toPath(), 
            StandardCharsets.UTF_8);

    for (String line : lines) {
        String[] array = line.split(",", -1);
        System.out.println(array[0]);
    }

}

Output:

a
1RW
1RW
1RW
1RW
1RW
1RW
1R1W
1R1W
1R1W

SQL is null and = null

It's important to note, that NULL doesn't equal NULL.

NULL is not a value, and therefore cannot be compared to another value.

where x is null checks whether x is a null value.

where x = null is checking whether x equals NULL, which will never be true

failed to resolve com.android.support:appcompat-v7:22 and com.android.support:recyclerview-v7:21.1.2

It is easier to use "+" sign in the version number. For example

compile 'com.android.support:support-v4:22.0.+'
compile "com.android.support:appcompat-v7:22.0.+"

In this case you won't have to change versions for the same API number

How to execute INSERT statement using JdbcTemplate class from Spring Framework

You can alternatively use NamedParameterJdbcTemplate (naming can be useful when you have many parameters)

Map<String, Object> params = new HashMap<>();
params.put("var1",value1); 
params.put("var2",value2); 
namedJdbcTemplate.update(
    "INSERT INTO schema.tableName (column1, column2) VALUES (:var1, :var2)",
    params
);

What does the keyword "transient" mean in Java?

Google is your friend - first hit - also you might first have a look at what serialization is.

It marks a member variable not to be serialized when it is persisted to streams of bytes. When an object is transferred through the network, the object needs to be 'serialized'. Serialization converts the object state to serial bytes. Those bytes are sent over the network and the object is recreated from those bytes. Member variables marked by the java transient keyword are not transferred, they are lost intentionally.

Example from there, slightly modified (thanks @pgras):

public class Foo implements Serializable
 {
   private String saveMe;
   private transient String dontSaveMe;
   private transient String password;
   //...
 }

How to display count of notifications in app launcher icon

This is sample and best way for showing badge on notification launcher icon.

Add This Class in your application

public class BadgeUtils {

    public static void setBadge(Context context, int count) {
        setBadgeSamsung(context, count);
        setBadgeSony(context, count);
    }

    public static void clearBadge(Context context) {
        setBadgeSamsung(context, 0);
        clearBadgeSony(context);
    }


    private static void setBadgeSamsung(Context context, int count) {
        String launcherClassName = getLauncherClassName(context);
        if (launcherClassName == null) {
            return;
        }
        Intent intent = new Intent("android.intent.action.BADGE_COUNT_UPDATE");
        intent.putExtra("badge_count", count);
        intent.putExtra("badge_count_package_name", context.getPackageName());
        intent.putExtra("badge_count_class_name", launcherClassName);
        context.sendBroadcast(intent);
    }

    private static void setBadgeSony(Context context, int count) {
        String launcherClassName = getLauncherClassName(context);
        if (launcherClassName == null) {
            return;
        }

        Intent intent = new Intent();
        intent.setAction("com.sonyericsson.home.action.UPDATE_BADGE");
        intent.putExtra("com.sonyericsson.home.intent.extra.badge.ACTIVITY_NAME", launcherClassName);
        intent.putExtra("com.sonyericsson.home.intent.extra.badge.SHOW_MESSAGE", true);
        intent.putExtra("com.sonyericsson.home.intent.extra.badge.MESSAGE", String.valueOf(count));
        intent.putExtra("com.sonyericsson.home.intent.extra.badge.PACKAGE_NAME", context.getPackageName());

        context.sendBroadcast(intent);
    }


    private static void clearBadgeSony(Context context) {
        String launcherClassName = getLauncherClassName(context);
        if (launcherClassName == null) {
            return;
        }

        Intent intent = new Intent();
        intent.setAction("com.sonyericsson.home.action.UPDATE_BADGE");
        intent.putExtra("com.sonyericsson.home.intent.extra.badge.ACTIVITY_NAME", launcherClassName);
        intent.putExtra("com.sonyericsson.home.intent.extra.badge.SHOW_MESSAGE", false);
        intent.putExtra("com.sonyericsson.home.intent.extra.badge.MESSAGE", String.valueOf(0));
        intent.putExtra("com.sonyericsson.home.intent.extra.badge.PACKAGE_NAME", context.getPackageName());

        context.sendBroadcast(intent);
    }

    private static String getLauncherClassName(Context context) {

        PackageManager pm = context.getPackageManager();

        Intent intent = new Intent(Intent.ACTION_MAIN);
        intent.addCategory(Intent.CATEGORY_LAUNCHER);

        List<ResolveInfo> resolveInfos = pm.queryIntentActivities(intent, 0);
        for (ResolveInfo resolveInfo : resolveInfos) {
            String pkgName = resolveInfo.activityInfo.applicationInfo.packageName;
            if (pkgName.equalsIgnoreCase(context.getPackageName())) {
                String className = resolveInfo.activityInfo.name;
                return className;
            }
        }
        return null;
    }


}

==> MyGcmListenerService.java Use BadgeUtils class when notification comes.

public class MyGcmListenerService extends GcmListenerService { 

    private static final String TAG = "MyGcmListenerService"; 
    @Override
    public void onMessageReceived(String from, Bundle data) {

            String message = data.getString("Msg");
            String Type = data.getString("Type"); 
            Intent intent = new Intent(this, SplashActivity.class);
            intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
            PendingIntent pendingIntent = PendingIntent.getActivity(this, 0 /* Request code */, intent,
                    PendingIntent.FLAG_ONE_SHOT);

            Uri defaultSoundUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);

            NotificationCompat.BigTextStyle bigTextStyle= new NotificationCompat.BigTextStyle();

            bigTextStyle .setBigContentTitle(getString(R.string.app_name))
                    .bigText(message);
            NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this)
                    .setSmallIcon(getNotificationIcon())
                    .setContentTitle(getString(R.string.app_name))
                    .setContentText(message)
                    .setStyle(bigTextStyle) 
                    .setAutoCancel(true)
                    .setSound(defaultSoundUri)
                    .setContentIntent(pendingIntent);

            int color = getResources().getColor(R.color.appColor);
            notificationBuilder.setColor(color);
            NotificationManager notificationManager =
                    (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);


            int unOpenCount=AppUtill.getPreferenceInt("NOTICOUNT",this);
            unOpenCount=unOpenCount+1;

            AppUtill.savePreferenceLong("NOTICOUNT",unOpenCount,this);  
            notificationManager.notify(unOpenCount /* ID of notification */, notificationBuilder.build()); 

// This is for bladge on home icon          
        BadgeUtils.setBadge(MyGcmListenerService.this,(int)unOpenCount);

    }


    private int getNotificationIcon() {
        boolean useWhiteIcon = (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP);
        return useWhiteIcon ? R.drawable.notification_small_icon : R.drawable.icon_launcher;
    }
}

And clear notification from preference and also with badge count

 public class SplashActivity extends AppCompatActivity { 
                @Override
                protected void onCreate(Bundle savedInstanceState) {
                    super.onCreate(savedInstanceState);
                    setContentView(R.layout.activity_splash);

                    AppUtill.savePreferenceLong("NOTICOUNT",0,this);
                    BadgeUtils.clearBadge(this);
            }
    }
<uses-permission android:name="com.sonyericsson.home.permission.BROADCAST_BADGE" />

SQL Server Pivot Table with multiple column aggregates

The least complicated, most straight-forward way of doing this is by simply wrapping your main query with the pivot in a common table expression, then grouping/aggregating.

WITH PivotCTE AS
(
    select * from  mytransactions
    pivot (sum (totalcount) for country in ([Australia], [Austria])) as pvt
)
SELECT
    numericmonth,
    chardate,
    SUM(totalamount) AS totalamount,
    SUM(ISNULL(Australia, 0)) AS Australia,
    SUM(ISNULL(Austria, 0)) Austria
FROM PivotCTE
GROUP BY numericmonth, chardate

The ISNULL is to stop a NULL value from nullifying the sum (because NULL + any value = NULL)

Passing a String by Reference in Java?

String is a special class in Java. It is Thread Safe which means "Once a String instance is created, the content of the String instance will never changed ".

Here is what is going on for

 zText += "foo";

First, Java compiler will get the value of zText String instance, then create a new String instance whose value is zText appending "foo". So you know why the instance that zText point to does not changed. It is totally a new instance. In fact, even String "foo" is a new String instance. So, for this statement, Java will create two String instance, one is "foo", another is the value of zText append "foo". The rule is simple: The value of String instance will never be changed.

For method fillString, you can use a StringBuffer as parameter, or you can change it like this:

String fillString(String zText) {
    return zText += "foo";
}

How to always show the vertical scrollbar in a browser?

Just a note: In OS X Lion, overflow set to "scroll" behaves more like auto in that scrollbars will only show when being used. They will disappear when not in use. So if any the solutions above don't appear to be working that might be why.

This is what you'll need to fix it:

::-webkit-scrollbar {
  -webkit-appearance: none;
  width: 7px;
}
::-webkit-scrollbar-thumb {
  border-radius: 4px;
  background-color: rgba(0, 0, 0, .5);
  -webkit-box-shadow: 0 0 1px rgba(255, 255, 255, .5);
}

You can style it accordingly.

Javascript to sort contents of select element

For those who are looking to sort whether or not there are optgroup :

/**
 * Sorting options 
 * and optgroups
 * 
 * @param selElem select element
 * @param optionBeforeGroup ?bool if null ignores, if true option appear before group else option appear after group
 */
function sortSelect(selElem, optionBeforeGroup = null) {
    let initialValue = selElem.tagName === "SELECT" ? selElem.value : null; 
    let allChildrens = Array.prototype.slice.call(selElem.childNodes);
    let childrens = [];

    for (let i = 0; i < allChildrens.length; i++) {
        if (allChildrens[i].parentNode === selElem && ["OPTGROUP", "OPTION"].includes(allChildrens[i].tagName||"")) {
            if (allChildrens[i].tagName == "OPTGROUP") {
                sortSelect(allChildrens[i]);
            }
            childrens.push(allChildrens[i]);
        }
    }

    childrens.sort(function(a, b){
        let x = a.tagName == "OPTGROUP" ? a.getAttribute("label") : a.innerHTML;
        let y = b.tagName == "OPTGROUP" ? b.getAttribute("label") : b.innerHTML;
        x = typeof x === "undefined" || x === null ? "" : (x+"");
        y = typeof y === "undefined" || y === null ? "" : (y+"");

        if (optionBeforeGroup === null) {
            if (x.toLowerCase().trim() < y.toLowerCase().trim()) {return -1;}
            if (x.toLowerCase().trim() > y.toLowerCase().trim()) {return 1;}
        } else if (optionBeforeGroup === true) {
            if ((a.tagName == "OPTION" && b.tagName == "OPTGROUP") || x.toLowerCase().trim() < y.toLowerCase().trim()) {return -1;}
            if ((a.tagName == "OPTGROUP" && b.tagName == "OPTION") || x.toLowerCase().trim() > y.toLowerCase().trim()) {return 1;}
        } else if (optionBeforeGroup === false) {
            if ((a.tagName == "OPTGROUP" && b.tagName == "OPTION") || x.toLowerCase().trim() < y.toLowerCase().trim()) {return -1;}
            if ((a.tagName == "OPTION" && b.tagName == "OPTGROUP") || x.toLowerCase().trim() > y.toLowerCase().trim()) {return 1;}
        }
        return 0;
    });

    if (optionBeforeGroup !== null) {
        childrens.sort(function(a, b){
            if (optionBeforeGroup === true) {
                if (a.tagName == "OPTION" && b.tagName == "OPTGROUP") {return -1;}
                if (a.tagName == "OPTGROUP" && b.tagName == "OPTION") {return 1;}
            } else {
                if (a.tagName == "OPTGROUP" && b.tagName == "OPTION") {return -1;}
                if (a.tagName == "OPTION" && b.tagName == "OPTGROUP") {return 1;}
            }
            return 0;
        });
    }

    selElem.innerHTML = "";
    for (let i = 0; i < childrens.length; i++) {
        selElem.appendChild(childrens[i]);
    }

    if (selElem.tagName === "SELECT") {
        selElem.value = initialValue;
    }
}

How do Common Names (CN) and Subject Alternative Names (SAN) work together?

CABForum Baseline Requirements

I see no one has mentioned the section in the Baseline Requirements yet. I feel they are important.

Q: SSL - How do Common Names (CN) and Subject Alternative Names (SAN) work together?
A: Not at all. If there are SANs, then CN can be ignored. -- At least if the software that does the checking adheres very strictly to the CABForum's Baseline Requirements.

(So this means I can't answer the "Edit" to your question. Only the original question.)

CABForum Baseline Requirements, v. 1.2.5 (as of 2 April 2015), page 9-10:

9.2.2 Subject Distinguished Name Fields
a. Subject Common Name Field
Certificate Field: subject:commonName (OID 2.5.4.3)
Required/Optional: Deprecated (Discouraged, but not prohibited)
Contents: If present, this field MUST contain a single IP address or Fully-Qualified Domain Name that is one of the values contained in the Certificate’s subjectAltName extension (see Section 9.2.1).

EDIT: Links from @Bruno's comment

RFC 2818: HTTP Over TLS, 2000, Section 3.1: Server Identity:

If a subjectAltName extension of type dNSName is present, that MUST be used as the identity. Otherwise, the (most specific) Common Name field in the Subject field of the certificate MUST be used. Although the use of the Common Name is existing practice, it is deprecated and Certification Authorities are encouraged to use the dNSName instead.

RFC 6125: Representation and Verification of Domain-Based Application Service Identity within Internet Public Key Infrastructure Using X.509 (PKIX) Certificates in the Context of Transport Layer Security (TLS), 2011, Section 6.4.4: Checking of Common Names:

[...] if and only if the presented identifiers do not include a DNS-ID, SRV-ID, URI-ID, or any application-specific identifier types supported by the client, then the client MAY as a last resort check for a string whose form matches that of a fully qualified DNS domain name in a Common Name field of the subject field (i.e., a CN-ID).

How to change value of a request parameter in laravel

Use merge():

$request->merge([
    'user_id' => $modified_user_id_here,
]);

Simple! No need to transfer the entire $request->all() to another variable.

How do I add a margin between bootstrap columns without wrapping

Change the number of @grid-columns. Then use -offset. Changing the number of columns will allow you to control the amount of space between columns. E.g.

variables.less (approx line 294).

@grid-columns:              20;

someName.html

<div class="row">
  <div class="col-md-4 col-md-offset-1">First column</div>
  <div class="col-md-13 col-md-offset-1">Second column</div>
</div>

Using a dictionary to count the items in a list

>>> L = ['apple','red','apple','red','red','pear']
>>> from collections import defaultdict
>>> d = defaultdict(int)
>>> for i in L:
...   d[i] += 1
>>> d
defaultdict(<type 'int'>, {'pear': 1, 'apple': 2, 'red': 3})

How can I generate Unix timestamps?

public static Int32 GetTimeStamp()
    {
        try
        {
            Int32 unixTimeStamp;
            DateTime currentTime = DateTime.Now;
            DateTime zuluTime = currentTime.ToUniversalTime();
            DateTime unixEpoch = new DateTime(1970, 1, 1);
            unixTimeStamp = (Int32)(zuluTime.Subtract(unixEpoch)).TotalSeconds;
            return unixTimeStamp;
        }
        catch (Exception ex)
        {
            Debug.WriteLine(ex);
            return 0;
        }
    }

What's an easy way to read random line from a file in Unix command line?

perlfaq5: How do I select a random line from a file? Here's a reservoir-sampling algorithm from the Camel Book:

perl -e 'srand; rand($.) < 1 && ($line = $_) while <>; print $line;' file

This has a significant advantage in space over reading the whole file in. You can find a proof of this method in The Art of Computer Programming, Volume 2, Section 3.4.2, by Donald E. Knuth.

Ng-model does not update controller value

For me the problem was solved by stocking my datas into an object (here "datas").

_x000D_
_x000D_
NgApp.controller('MyController', function($scope) {_x000D_
_x000D_
   $scope.my_title = ""; // This don't work in ng-click function called_x000D_
_x000D_
   $scope.datas = {_x000D_
      'my_title' : "",_x000D_
   };_x000D_
_x000D_
   $scope.doAction = function() {_x000D_
         console.log($scope.my_title); // bad value_x000D_
         console.log($scope.datas.my_title); // Good Value binded by'ng-model'_x000D_
   }_x000D_
   _x000D_
_x000D_
});
_x000D_
_x000D_
_x000D_

I Hop it will help