Programs & Examples On #Defragmentation

The process of decreasing the amount of fragmented files on a computer's system hard drive.

Running Groovy script from the command line

It will work on Linux kernel 2.6.28 (confirmed on 4.9.x). It won't work on FreeBSD and other Unix flavors.

Your /usr/local/bin/groovy is a shell script wrapping the Java runtime running Groovy.

See the Interpreter Scripts section of EXECVE(2) and EXECVE(2).

There is already an object named in the database

The below steps worked for me for the same issue:

Scenario:

I was trying to add 2 new fields to my existing model for Email functionality. The new fields are "IsEmailVerified" and "ActivationCode"

Steps i have followed:

1.Deleted old migration files under "Migrations" folder which are prevented me to do Update-Database 2.Reverted all my recent changes that i have did on the model

3.Run the below command:

Add-Migration -ConnectionProviderName System.Data.SqlClient -ConnectionString "Data Source=DESKTOP\SQLEXPRESS;Initial Catalog=Custom;Persist Security Info=True;User ID=sa;password=****"

4.Deleted the contents from Up() and Down() methods from migration file and left the methods empty

5.Run the below command:

Update-Database -ConnectionProviderName System.Data.SqlClient -ConnectionString "Data Source=DESKTOP\SQLEXPRESS;Initial Catalog=Custom;Persist Security Info=True;User ID=sa;password="***

  1. After executes the above step, model and DB looks sync.

  2. Now, i added the new properties in the model

         public bool IsEmailVerified { get; set; }
         public Guid ActivationCode { get; set; }
    
  3. Run the below command:

Add-Migration -ConnectionProviderName System.Data.SqlClient -ConnectionString "Data Source=DESKTOP\SQLEXPRESS;Initial Catalog=Custom;Persist Security Info=True;User ID=sa;password="***

  1. Now the migration file contains only my recent changes as below:

       public override void Up()
         {
             AddColumn("dbo.UserAccounts", "IsEmailVerified", c => c.Boolean(nullable: false));
             AddColumn("dbo.UserAccounts", "ActivationCode", c => c.Guid(nullable: false));
         }        
         public override void Down()
         {
             DropColumn("dbo.UserAccounts", "ActivationCode");
             DropColumn("dbo.UserAccounts", "IsEmailVerified");
         }
    
  2. Run the below command: Update-Database -ConnectionProviderName System.Data.SqlClient -ConnectionString "Data Source=DESKTOP\SQLEXPRESS;Initial Catalog=Custom;Persist Security Info=True;User ID=sa;password="***

11.Now i successfully updated the database with additional columns.

The below is updated table after the recent changes:

Table after the update migration

Setting up a git remote origin

For anyone who comes here, as I did, looking for the syntax to change origin to a different location you can find that documentation here: https://help.github.com/articles/changing-a-remote-s-url/. Using git remote add to do this will result in "fatal: remote origin already exists."

Nutshell: git remote set-url origin https://github.com/username/repo

(The marked answer is correct, I'm just hoping to help anyone as lost as I was... haha)

How do I find out what version of WordPress is running?

I know I'm super late regarding this topic but there's this easy to use library where you can easily get the version numbers of Worpress, PHP, Apache, and MySQL, all-in-one.

It is called the Wordpress Environment (W18T) library

<?php
include_once 'W18T.class.php';
$environment = new W18T();
echo $environment;
?>

Output

{
    "platform": {
        "name": "WordPress",
        "version": "4.9.1"
    },
    "interpreter": {
        "name": "PHP",
        "version": "7.2.0"
    },
    "web_server": {
        "name": "Apache",
        "version": "2.4.16"
    },
    "database_server": {
        "name": "MySQL",
        "version": "5.7.20"
    },
    "operating_system": {
        "name": "Darwin",
        "version": "17.0.0"
    }
}

I hope it helps.

Forward host port to docker container

A simple but relatively insecure way would be to use the --net=host option to docker run.

This option makes it so that the container uses the networking stack of the host. Then you can connect to services running on the host simply by using "localhost" as the hostname.

This is easier to configure because you won't have to configure the service to accept connections from the IP address of your docker container, and you won't have to tell the docker container a specific IP address or host name to connect to, just a port.

For example, you can test it out by running the following command, which assumes your image is called my_image, your image includes the telnet utility, and the service you want to connect to is on port 25:

docker run --rm -i -t --net=host my_image telnet localhost 25

If you consider doing it this way, please see the caution about security on this page:

https://docs.docker.com/articles/networking/

It says:

--net=host -- Tells Docker to skip placing the container inside of a separate network stack. In essence, this choice tells Docker to not containerize the container's networking! While container processes will still be confined to their own filesystem and process list and resource limits, a quick ip addr command will show you that, network-wise, they live “outside” in the main Docker host and have full access to its network interfaces. Note that this does not let the container reconfigure the host network stack — that would require --privileged=true — but it does let container processes open low-numbered ports like any other root process. It also allows the container to access local network services like D-bus. This can lead to processes in the container being able to do unexpected things like restart your computer. You should use this option with caution.

SSL handshake alert: unrecognized_name error since upgrade to Java 1.7.0

Java 7 introduced SNI support which is enabled by default. I have found out that certain misconfigured servers send an "Unrecognized Name" warning in the SSL handshake which is ignored by most clients... except for Java. As @Bob Kerns mentioned, the Oracle engineers refuse to "fix" this bug/feature.

As workaround, they suggest to set the jsse.enableSNIExtension property. To allow your programs to work without re-compiling, run your app as:

java -Djsse.enableSNIExtension=false yourClass

The property can also be set in the Java code, but it must be set before any SSL actions. Once the SSL library has loaded, you can change the property, but it won't have any effect on the SNI status. To disable SNI on runtime (with the aforementioned limitations), use:

System.setProperty("jsse.enableSNIExtension", "false");

The disadvantage of setting this flag is that SNI is disabled everywhere in the application. In order to make use of SNI and still support misconfigured servers:

  1. Create a SSLSocket with the host name you want to connect to. Let's name this sslsock.
  2. Try to run sslsock.startHandshake(). This will block until it is done or throw an exception on error. Whenever an error occurred in startHandshake(), get the exception message. If it equals to handshake alert: unrecognized_name, then you have found a misconfigured server.
  3. When you have received the unrecognized_name warning (fatal in Java), retry opening a SSLSocket, but this time without a host name. This effectively disables SNI (after all, the SNI extension is about adding a host name to the ClientHello message).

For the Webscarab SSL proxy, this commit implements the fall-back setup.

What does Java option -Xmx stand for?

The -Xmx option changes the maximum Heap Space for the VM. java -Xmx1024m means that the VM can allocate a maximum of 1024 MB. In layman terms this means that the application can use a maximum of 1024MB of memory.

Where to put Gradle configuration (i.e. credentials) that should not be committed?

~/.gradle/gradle.properties:

mavenUser=admin
mavenPassword=admin123

build.gradle:

...
authentication(userName: mavenUser, password: mavenPassword)

Make an image follow mouse pointer

by using jquery to register .mousemove to document to change the image .css left and top to event.pageX and event.pageY.

example as below http://jsfiddle.net/BfLAh/1/

_x000D_
_x000D_
$(document).mousemove(function(e) {
  $("#follow").css({
    left: e.pageX,
    top: e.pageY
  });
});
_x000D_
#follow {
  position: absolute;
  text-align: center;
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="follow"><img src="https://placekitten.com/96/140" /><br>Kitteh</br>
</div>
_x000D_
_x000D_
_x000D_

updated to follow slowly

http://jsfiddle.net/BfLAh/3/

for the orientation , you need to get the current css left and css top and compare with event.pageX and event.pageY , then set the image orientation with

-webkit-transform: rotate(-90deg); 
-moz-transform: rotate(-90deg); 

for the speed , you can set the jquery .animation duration to certain amount.

How do I get the file extension of a file in Java?

How about JFileChooser? It is not straightforward as you will need to parse its final output...

JFileChooser filechooser = new JFileChooser();
File file = new File("your.txt");
System.out.println("the extension type:"+filechooser.getTypeDescription(file));

which is a MIME type...

OK...I forget that you don't want to know its MIME type.

Interesting code in the following link: http://download.oracle.com/javase/tutorial/uiswing/components/filechooser.html

/*
 * Get the extension of a file.
 */  
public static String getExtension(File f) {
    String ext = null;
    String s = f.getName();
    int i = s.lastIndexOf('.');

    if (i > 0 &&  i < s.length() - 1) {
        ext = s.substring(i+1).toLowerCase();
    }
    return ext;
}

Related question: How do I trim a file extension from a String in Java?

Dropping a connected user from an Oracle 10g database schema

just use SQL :

disconnect; 

conn tiger/scott as sysdba;

How can I escape latex code received through user input?

Python’s raw strings are just a way to tell the Python interpreter that it should interpret backslashes as literal slashes. If you read strings entered by the user, they are already past the point where they could have been raw. Also, user input is most likely read in literally, i.e. “raw”.

This means the interpreting happens somewhere else. But if you know that it happens, why not escape the backslashes for whatever is interpreting it?

s = s.replace("\\", "\\\\")

(Note that you can't do r"\" as “a raw string cannot end in a single backslash”, but I could have used r"\\" as well for the second argument.)

If that doesn’t work, your user input is for some arcane reason interpreting the backslashes, so you’ll need a way to tell it to stop that.

Vim: insert the same characters across multiple lines

Use Ctrl+V to enter visual block mode
Move Up/Down to select the columns of text in the lines you want to comment.
Then hit Shift+i and type the text you want to insert.
Then hit Esc, wait 1 second and the inserted text will appear on every line

Handling a timeout error in python sockets

I had enough success just catchig socket.timeout and socket.error; although socket.error can be raised for lots of reasons. Be careful.

import socket
import logging

hostname='google.com'
port=443

try:
    sock = socket.create_connection((hostname, port), timeout=3)

except socket.timeout as err:
    logging.error(err)

except socket.error as err:
    logging.error(err)

How can I make a horizontal ListView in Android?

Have you looked into using a HorizontalScrollView to wrap your list items? That will allow each of your list items to be horizontally scrollable (what you put in there is up to you, and can make them dynamic items similar to ListView). This will work well if you are only after a single row of items.

How can I initialize a C# List in the same line I declare it. (IEnumerable string Collection Example)

This is one way.

List<int> list = new List<int>{ 1, 2, 3, 4, 5 };

This is another way.

List<int> list2 = new List<int>();

list2.Add(1);

list2.Add(2);

Same goes with strings.

Eg:

List<string> list3 = new List<string> { "Hello", "World" };

How to remove td border with html?

First

<table border="1">
      <tr>
        <td style='border:none;'>one</td>
        <td style='border:none;'>two</td>
      </tr>
      <tr>
        <td style='border:none;'>one</td>
        <td style='border:none;'>two</td>
    </tr>
    </table>

Second example

<table border="1" cellspacing="0" cellpadding="0">
  <tr>
    <td style='border-left:none;border-top:none'>one</td>
    <td style='border:none;'>two</td>
  </tr>
  <tr>
    <td style='border-left:none;border-bottom:none;border-top:none'>one</td>
    <td style='border:none;'>two</td>
</tr>
</table>

npm not working after clearing cache

"As of npm@5, the npm cache self-heals from corruption issues and data extracted from the cache is guaranteed to be valid. If you want to make sure everything is consistent, use

npm cache verify

instead."

Sniff HTTP packets for GET and POST requests from an application

You will have to use some sort of network sniffer if you want to get at this sort of data and you're likely to run into the same problem (pulling out the relevant data from the overall network traffic) with those that you do now with Wireshark.

Convert Python dict into a dataframe

In my case I wanted keys and values of a dict to be columns and values of DataFrame. So the only thing that worked for me was:

data = {'adjust_power': 'y', 'af_policy_r_submix_prio_adjust': '[null]', 'af_rf_info': '[null]', 'bat_ac': '3500', 'bat_capacity': '75'} 

columns = list(data.keys())
values = list(data.values())
arr_len = len(values)

pd.DataFrame(np.array(values, dtype=object).reshape(1, arr_len), columns=columns)

Differences between Oracle JDK and OpenJDK

  1. Oracle will deliver releases every three years, while OpenJDK will be released every six months.
  2. Oracle provides long term support for its releases. On the other hand, OpenJDK supports the changes to a release only until the next version is released.
  3. Oracle JDK was licensed under Oracle Binary Code License Agreement, whereas OpenJDK has the GNU General Public License (GNU GPL) version 2 with a linking exception.
  4. Oracle product has Flight Recorder, Java Mission Control, and Application Class-Data Sharing features, while OpenJDK has the Font Renderer feature.Also, Oracle has more Garbage Collection options and better renderers,
  5. Oracle JDK is fully developed by Oracle Corporation whereas the OpenJDK is developed by Oracle, OpenJDK, and the Java Community. However, the top-notch companies like Red Hat, Azul Systems, IBM, Apple Inc., SAP AG also take an active part in its development.

From Java 11 turn to a big change

Oracle will change its historical “BCL” license with a combination of an open source and commercial license

  • Oracle’s kit for Java 11 emits a warning when using the -XX:+UnlockCommercialFeatures option, whereas in OpenJDK builds, this option results in an error
  • Oracle JDK offers a configuration to provide usage log data to the “Advanced Management Console” tool
  • Oracle has always required third party cryptographic providers to be signed by a known certificate, while cryptography framework in OpenJDK has an open cryptographic interface, which means there is no restriction as to which providers can be used
  • Oracle JDK 11 will continue to include installers, branding, and JRE packaging, whereas OpenJDK builds are currently available as zip and tar.gz files
  • The javac –release command behaves differently for the Java 9 and Java 10 targets due to the presence of some additional modules in Oracle’s release
  • The output of the java –version and java -fullversion commands will distinguish Oracle’s builds from OpenJDK builds


Update : 25-Aug-2019



enter image description here

for more details oracle-vs-openjdk

See full command of running/stopped container in Docker

TL-DR

docker ps --no-trunc and docker inspect CONTAINER provide the entrypoint executed to start the container, along the command passed to, but that may miss some parts such as ${ANY_VAR} because container environment variables are not printed as resolved.

To overcome that, docker inspect CONTAINER has an advantage because it also allow to retrieve separately env variables and their values defined in the container from the Config.Env property.

docker ps and docker inspect provide information about the executed entrypoint and its command. Often, that is a wrapper entrypoint script (.sh) and not the "real" program started by the container. To get information on that, requesting process information with ps or /proc/1/cmdline help.


1) docker ps --no-trunc

It prints the entrypoint and the command executed for all running containers. While it prints the command passed to the entrypoint (if we pass that), it doesn't show value of docker env variables (such as $FOO or ${FOO}).
If our containers use env variables, it may be not enough.

For example, run an alpine container :

docker run --name alpine-example -e MY_VAR=/var alpine:latest sh -c 'ls $MY_VAR'

When use docker -ps such as :

docker ps -a --filter name=alpine-example --no-trunc

It prints :

CONTAINER ID           IMAGE               COMMAND                CREATED             STATUS                     PORTS               NAMES
5b064a6de6d8417...   alpine:latest       "sh -c 'ls $MY_VAR'"   2 minutes ago       Exited (0) 2 minutes ago                       alpine-example

We see the command passed to the entrypoint : sh -c 'ls $MY_VAR' but $MY_VAR is indeed not resolved.

2) docker inspect CONTAINER

When we inspect the alpine-example container :

docker inspect alpine-example | grep -4 Cmd

The command is also there but we don't still see the env variable value :

        "Cmd": [
            "sh",
            "-c",
            "ls $MY_VAR"
        ],

In fact, we could not see interpolated variables with these docker commands.
While as a trade-off, we could display separately both command and env variables for a container with docker inspect :

docker inspect  alpine-example  | grep -4 -E "Cmd|Env"

That prints :

        "Env": [
            "MY_VAR=/var",
            "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
        ],
        "Cmd": [
            "sh",
            "-c",
            "ls $MY_VAR"
        ]

A more docker way would be to use the --format flag of docker inspect that allows to specify JSON attributes to render :

docker inspect --format '{{.Name}} {{.Config.Cmd}}  {{ (.Config.Env) }}'  alpine-example

That outputs :

/alpine-example [sh -c ls $MY_VAR]  [MY_VAR=/var PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin]

3) Retrieve the started process from the container itself for running containers

The entrypoint and command executed by docker may be helpful but in some cases, it is not enough because that is "only" a wrapper entrypoint script (.sh) that is responsible to start the real/core process.
For example when I run a Nexus container, the command executed and shown to run the container is "sh -c ${SONATYPE_DIR}/start-nexus-repository-manager.sh".
For PostgreSQL that is "docker-entrypoint.sh postgres".

To get more information, we could execute on a running container docker exec CONTAINER ps aux.
It may print other processes that may not interest us.
To narrow to the initial process launched by the entrypoint, we could do :

docker exec CONTAINER ps -1

I specify 1 because the process executed by the entrypoint is generally the one with the 1 id.

Without ps, we could still find the information in /proc/1/cmdline (in most of Linux distros but not all). For example :

docker exec CONTAINER cat /proc/1/cmdline | sed -e "s/\x00/ /g"; echo    

If we have access to the docker host that started the container, another alternative to get the full command of the process executed by the entrypoint is : : execute ps -PID where PID is the local process created by the Docker daemon to run the container such as :

ps -$(docker container inspect --format '{{.State.Pid}}'  CONTAINER)

User-friendly formatting with docker ps

docker ps --no-trunc is not always easy to read.
Specifying columns to print and in a tabular format may make it better :

docker ps   --no-trunc  --format "table{{.Names}}\t{{.CreatedAt}}\t{{.Command}}"

Create an alias may help :

alias dps='docker ps   --no-trunc  --format "table{{.Names}}\t{{.CreatedAt}}\t{{.Command}}"'

Android Endless List

I've been working in another solution very similar to that, but, I am using a footerView to give the possibility to the user download more elements clicking the footerView, I am using a "menu" which is shown above the ListView and in the bottom of the parent view, this "menu" hides the bottom of the ListView, so, when the listView is scrolling the menu disappear and when scroll state is idle, the menu appear again, but when the user scrolls to the end of the listView, I "ask" to know if the footerView is shown in that case, the menu doesn't appear and the user can see the footerView to load more content. Here the code:

Regards.

listView.setOnScrollListener(new OnScrollListener() {

    @Override
    public void onScrollStateChanged(AbsListView view, int scrollState) {
        // TODO Auto-generated method stub
        if(scrollState == SCROLL_STATE_IDLE) {
            if(footerView.isShown()) {
                bottomView.setVisibility(LinearLayout.INVISIBLE);
            } else {
                bottomView.setVisibility(LinearLayout.VISIBLE);
            } else {
                bottomView.setVisibility(LinearLayout.INVISIBLE);
            }
        }
    }

    @Override
    public void onScroll(AbsListView view, int firstVisibleItem,
            int visibleItemCount, int totalItemCount) {

    }
});

Could not load file or assembly 'System.Web.Mvc'

Had the same issue and added all the assembly that they said but still got the same error.

turns out you need to make the "Specific Version" = False.

Specific version should be false.

JavaScript, getting value of a td with id name

To get the text content

document.getElementById ( "tdid" ).innerText

or

document.getElementById ( "tdid" ).textContent

var tdElem = document.getElementById ( "tdid" );
var tdText = tdElem.innerText | tdElem.textContent;

If you can use jQuery then you can use

$("#tdid").text();

To get the HTML content

var tdElem = document.getElementById ( "tdid" );
var tdText = tdElem.innerHTML;

in jQuery

$("#tdid").html();

python request with authentication (access_token)

>>> import requests
>>> response = requests.get('https://website.com/id', headers={'Authorization': 'access_token myToken'})

If the above doesnt work , try this:

>>> import requests
>>> response = requests.get('https://api.buildkite.com/v2/organizations/orgName/pipelines/pipelineName/builds/1230', headers={ 'Authorization': 'Bearer <your_token>' })
>>> print response.json()

Passing event and argument to v-on in Vue.js

Depending on what arguments you need to pass, especially for custom event handlers, you can do something like this:

<div @customEvent='(arg1) => myCallback(arg1, arg2)'>Hello!</div>

How to Get XML Node from XDocument

test.xml:

<?xml version="1.0" encoding="utf-8"?>
<Contacts>
  <Node>
    <ID>123</ID>
    <Name>ABC</Name>
  </Node>
  <Node>
    <ID>124</ID>
    <Name>DEF</Name>
  </Node>
</Contacts>

Select a single node:

XDocument XMLDoc = XDocument.Load("test.xml");
string id = "123"; // id to be selected

XElement Contact = (from xml2 in XMLDoc.Descendants("Node")
                    where xml2.Element("ID").Value == id
                    select xml2).FirstOrDefault();

Console.WriteLine(Contact.ToString());

Delete a single node:

XDocument XMLDoc = XDocument.Load("test.xml");
string id = "123";

var Contact = (from xml2 in XMLDoc.Descendants("Node")
               where xml2.Element("ID").Value == id
               select xml2).FirstOrDefault();

Contact.Remove();
XMLDoc.Save("test.xml");

Add new node:

XDocument XMLDoc = XDocument.Load("test.xml");

XElement newNode = new XElement("Node",
    new XElement("ID", "500"),
    new XElement("Name", "Whatever")
);

XMLDoc.Element("Contacts").Add(newNode);
XMLDoc.Save("test.xml");

How do I find the length (or dimensions, size) of a numpy matrix in python?

shape is a property of both numpy ndarray's and matrices.

A.shape

will return a tuple (m, n), where m is the number of rows, and n is the number of columns.

In fact, the numpy matrix object is built on top of the ndarray object, one of numpy's two fundamental objects (along with a universal function object), so it inherits from ndarray

How to change the sender's name or e-mail address in mutt?

For a one time change you can do this:

export EMAIL='[email protected]'; mutt -s "Elvis is dead" [email protected]

How do I see what character set a MySQL database / table / column is?

For all the databases you have on the server:

mysql> SELECT SCHEMA_NAME 'database', default_character_set_name 'charset', DEFAULT_COLLATION_NAME 'collation' FROM information_schema.SCHEMATA;

Output:

+----------------------------+---------+--------------------+
| database                   | charset | collation          |
+----------------------------+---------+--------------------+
| information_schema         | utf8    | utf8_general_ci    |
| my_database                | latin1  | latin1_swedish_ci  |
...
+----------------------------+---------+--------------------+

For a single Database:

mysql> USE my_database;
mysql> show variables like "character_set_database";

Output:

    +----------------------------+---------+
    | Variable_name              |  Value  |
    +----------------------------+---------+
    | character_set_database     |  latin1 | 
    +----------------------------+---------+

Getting the collation for Tables:

mysql> USE my_database;
mysql> SHOW TABLE STATUS WHERE NAME LIKE 'my_tablename';

OR - will output the complete SQL for create table:

mysql> show create table my_tablename


Getting the collation of columns:

mysql> SHOW FULL COLUMNS FROM my_tablename;

output:

+---------+--------------+--------------------+ ....
| field   | type         | collation          |
+---------+--------------+--------------------+ ....
| id      | int(10)      | (NULL)             |
| key     | varchar(255) | latin1_swedish_ci  |
| value   | varchar(255) | latin1_swedish_ci  |
+---------+--------------+--------------------+ ....

What are the ascii values of up down left right?

There is no real ascii codes for these keys as such, you will need to check out the scan codes for these keys, known as Make and Break key codes as per helppc's information. The reason the codes sounds 'ascii' is because the key codes are handled by the old BIOS interrupt 0x16 and keyboard interrupt 0x9.

                 Normal Mode            Num lock on
                 Make    Break        Make          Break
Down arrow       E0 50   E0 D0     E0 2A E0 50   E0 D0 E0 AA
Left arrow       E0 4B   E0 CB     E0 2A E0 4B   E0 CB E0 AA
Right arrow      E0 4D   E0 CD     E0 2A E0 4D   E0 CD E0 AA
Up arrow         E0 48   E0 C8     E0 2A E0 48   E0 C8 E0 AA

Hence by looking at the codes following E0 for the Make key code, such as 0x50, 0x4B, 0x4D, 0x48 respectively, that is where the confusion arise from looking at key-codes and treating them as 'ascii'... the answer is don't as the platform varies, the OS varies, under Windows it would have virtual key code corresponding to those keys, not necessarily the same as the BIOS codes, VK_UP, VK_DOWN, VK_LEFT, VK_RIGHT.. this will be found in your C++'s header file windows.h, as I recall in the SDK's include folder.

Do not rely on the key-codes to have the same 'identical ascii' codes shown here as the Operating system will reprogram the entire BIOS code in whatever the OS sees fit, naturally that would be expected because since the BIOS code is 16bit, and the OS (nowadays are 32bit protected mode), of course those codes from the BIOS will no longer be valid.

Hence the original keyboard interrupt 0x9 and BIOS interrupt 0x16 would be wiped from the memory after the BIOS loads it and when the protected mode OS starts loading, it would overwrite that area of memory and replace it with their own 32 bit protected mode handlers to deal with those keyboard scan codes.

Here is a code sample from the old days of DOS programming, using Borland C v3:

#include <bios.h>
int getKey(void){
    int key, lo, hi;
    key = bioskey(0);
    lo = key & 0x00FF;
    hi = (key & 0xFF00) >> 8;
    return (lo == 0) ? hi + 256 : lo;
}

This routine actually, returned the codes for up, down is 328 and 336 respectively, (I do not have the code for left and right actually, this is in my old cook book!) The actual scancode is found in the lo variable. Keys other than the A-Z,0-9, had a scan code of 0 via the bioskey routine.... the reason 256 is added, because variable lo has code of 0 and the hi variable would have the scan code and adds 256 on to it in order not to confuse with the 'ascii' codes...

ORACLE convert number to string

This should solve your problem:

select replace(to_char(a, '90D90'),'.00','')
from
(
select 50 a from dual
union
select 50.57 from dual
union
select 5.57 from dual
union
select 0.35 from dual
union
select 0.4 from dual
);

Give a look also as this SQL Fiddle for test.

What is the purpose of wrapping whole Javascript files in anonymous functions like “(function(){ … })()”?

In short

Summary

In its simplest form, this technique aims to wrap code inside a function scope.

It helps decreases chances of:

  • clashing with other applications/libraries
  • polluting superior (global most likely) scope

It does not detect when the document is ready - it is not some kind of document.onload nor window.onload

It is commonly known as an Immediately Invoked Function Expression (IIFE) or Self Executing Anonymous Function.

Code Explained

var someFunction = function(){ console.log('wagwan!'); };

(function() {                   /* function scope starts here */
  console.log('start of IIFE');

  var myNumber = 4;             /* number variable declaration */
  var myFunction = function(){  /* function variable declaration */
    console.log('formidable!'); 
  };
  var myObject = {              /* object variable declaration */
    anotherNumber : 1001, 
    anotherFunc : function(){ console.log('formidable!'); }
  };
  console.log('end of IIFE');
})();                           /* function scope ends */

someFunction();            // reachable, hence works: see in the console
myFunction();              // unreachable, will throw an error, see in the console
myObject.anotherFunc();    // unreachable, will throw an error, see in the console

In the example above, any variable defined in the function (i.e. declared using var) will be "private" and accessible within the function scope ONLY (as Vivin Paliath puts it). In other words, these variables are not visible/reachable outside the function. See live demo.

Javascript has function scoping. "Parameters and variables defined in a function are not visible outside of the function, and that a variable defined anywhere within a function is visible everywhere within the function." (from "Javascript: The Good Parts").


More details

Alternative Code

In the end, the code posted before could also be done as follows:

var someFunction = function(){ console.log('wagwan!'); };

var myMainFunction = function() {
  console.log('start of IIFE');

  var myNumber = 4;
  var myFunction = function(){ console.log('formidable!'); };
  var myObject = { 
    anotherNumber : 1001, 
    anotherFunc : function(){ console.log('formidable!'); }
  };
  console.log('end of IIFE');
};

myMainFunction();          // I CALL "myMainFunction" FUNCTION HERE
someFunction();            // reachable, hence works: see in the console
myFunction();              // unreachable, will throw an error, see in the console
myObject.anotherFunc();    // unreachable, will throw an error, see in the console

See live demo.


The Roots

Iteration 1

One day, someone probably thought "there must be a way to avoid naming 'myMainFunction', since all we want is to execute it immediately."

If you go back to the basics, you find out that:

  • expression: something evaluating to a value. i.e. 3+11/x
  • statement: line(s) of code doing something BUT it does not evaluate to a value. i.e. if(){}

Similarly, function expressions evaluate to a value. And one consequence (I assume?) is that they can be immediately invoked:

 var italianSayinSomething = function(){ console.log('mamamia!'); }();

So our more complex example becomes:

var someFunction = function(){ console.log('wagwan!'); };

var myMainFunction = function() {
  console.log('start of IIFE');

  var myNumber = 4;
  var myFunction = function(){ console.log('formidable!'); };
  var myObject = { 
    anotherNumber : 1001, 
    anotherFunc : function(){ console.log('formidable!'); }
  };
  console.log('end of IIFE');
}();

someFunction();            // reachable, hence works: see in the console
myFunction();              // unreachable, will throw an error, see in the console
myObject.anotherFunc();    // unreachable, will throw an error, see in the console

See live demo.

Iteration 2

The next step is the thought "why have var myMainFunction = if we don't even use it!?".

The answer is simple: try removing this, such as below:

 function(){ console.log('mamamia!'); }();

See live demo.

It won't work because "function declarations are not invokable".

The trick is that by removing var myMainFunction = we transformed the function expression into a function declaration. See the links in "Resources" for more details on this.

The next question is "why can't I keep it as a function expression with something other than var myMainFunction =?

The answer is "you can", and there are actually many ways you could do this: adding a +, a !, a -, or maybe wrapping in a pair of parenthesis (as it's now done by convention), and more I believe. As example:

 (function(){ console.log('mamamia!'); })(); // live demo: jsbin.com/zokuwodoco/1/edit?js,console.

or

 +function(){ console.log('mamamia!'); }(); // live demo: jsbin.com/wuwipiyazi/1/edit?js,console

or

 -function(){ console.log('mamamia!'); }(); // live demo: jsbin.com/wejupaheva/1/edit?js,console

So once the relevant modification is added to what was once our "Alternative Code", we return to the exact same code as the one used in the "Code Explained" example

var someFunction = function(){ console.log('wagwan!'); };

(function() {
  console.log('start of IIFE');

  var myNumber = 4;
  var myFunction = function(){ console.log('formidable!'); };
  var myObject = { 
    anotherNumber : 1001, 
    anotherFunc : function(){ console.log('formidable!'); }
  };
  console.log('end of IIFE');
})();

someFunction();            // reachable, hence works: see in the console
myFunction();              // unreachable, will throw an error, see in the console
myObject.anotherFunc();    // unreachable, will throw an error, see in the console

Read more about Expressions vs Statements:


Demystifying Scopes

One thing one might wonder is "what happens when you do NOT define the variable 'properly' inside the function -- i.e. do a simple assignment instead?"

(function() {
  var myNumber = 4;             /* number variable declaration */
  var myFunction = function(){  /* function variable declaration */
    console.log('formidable!'); 
  };
  var myObject = {              /* object variable declaration */
    anotherNumber : 1001, 
    anotherFunc : function(){ console.log('formidable!'); }
  };
  myOtherFunction = function(){  /* oops, an assignment instead of a declaration */
    console.log('haha. got ya!');
  };
})();
myOtherFunction();         // reachable, hence works: see in the console
window.myOtherFunction();  // works in the browser, myOtherFunction is then in the global scope
myFunction();              // unreachable, will throw an error, see in the console

See live demo.

Basically, if a variable that was not declared in its current scope is assigned a value, then "a look up the scope chain occurs until it finds the variable or hits the global scope (at which point it will create it)".

When in a browser environment (vs a server environment like nodejs) the global scope is defined by the window object. Hence we can do window.myOtherFunction().

My "Good practices" tip on this topic is to always use var when defining anything: whether it's a number, object or function, & even when in the global scope. This makes the code much simpler.

Note:

  • javascript does not have block scope (Update: block scope local variables added in ES6.)
  • javascript has only function scope & global scope (window scope in a browser environment)

Read more about Javascript Scopes:


Resources


Next Steps

Once you get this IIFE concept, it leads to the module pattern, which is commonly done by leveraging this IIFE pattern. Have fun :)

Why SQL Server throws Arithmetic overflow error converting int to data type numeric?

Precision and scale are often misunderstood. In numeric(3,2) you want 3 digits overall, but 2 to the right of the decimal. If you want 15 => 15.00 so the leading 1 causes the overflow (since if you want 2 digits to the right of the decimal, there is only room on the left for one more digit). With 4,2 there is no problem because all 4 digits fit.

Uncaught syntaxerror: unexpected identifier?

There are errors here :

var formTag = document.getElementsByTagName("form"), // form tag is an array
selectListItem = $('select'),
makeSelect = document.createElement('select'),
makeSelect.setAttribute("id", "groups");

The code must change to:

var formTag = document.getElementsByTagName("form");
var selectListItem = $('select');
var makeSelect = document.createElement('select');
makeSelect.setAttribute("id", "groups");

By the way, there is another error at line 129 :

var createLi.appendChild(createSubList);

Replace it with:

createLi.appendChild(createSubList);

The type arguments cannot be inferred from the usage. Try specifying the type arguments explicitly

I know this question already has an accepted answer, but for me, a .NET beginner, there was a simple solution to what I was doing wrong and I thought I'd share.

I had been doing this:

@Html.HiddenFor(Model.Foo.Bar.ID)

What worked for me was changing to this:

@Html.HiddenFor(m => m.Foo.Bar.ID)

(where "m" is an arbitrary string to represent the model object)

multiple conditions for JavaScript .includes() method

That can be done by using some/every methods of Array and RegEx.

To check whether ALL of words from list(array) are present in the string:

const multiSearchAnd = (text, searchWords) => (
  searchWords.every((el) => {
    return text.match(new RegExp(el,"i"))
  })
)

multiSearchAnd("Chelsey Dietrich Engineer 2018-12-11 Hire", ["cle", "hire"]) //returns false
multiSearchAnd("Chelsey Dietrich Engineer 2018-12-11 Hire", ["che", "hire"]) //returns true

To check whether ANY of words from list(array) are present in the string:

const multiSearchOr = (text, searchWords) => (
  searchWords.some((el) => {
    return text.match(new RegExp(el,"i"))
  })
)

multiSearchOr("Chelsey Dietrich Engineer 2018-12-11 Hire", ["che", "hire"]) //returns true
multiSearchOr("Chelsey Dietrich Engineer 2018-12-11 Hire", ["aaa", "hire"]) //returns true
multiSearchOr("Chelsey Dietrich Engineer 2018-12-11 Hire", ["che", "zzzz"]) //returns true
multiSearchOr("Chelsey Dietrich Engineer 2018-12-11 Hire", ["aaa", "1111"]) //returns false

Is it possible to view RabbitMQ message contents directly from the command line?

Here are the commands I use to get the contents of the queue:

RabbitMQ version 3.1.5 on Fedora linux using https://www.rabbitmq.com/management-cli.html

Here are my exchanges:

eric@dev ~ $ sudo python rabbitmqadmin list exchanges
+-------+--------------------+---------+-------------+---------+----------+
| vhost |        name        |  type   | auto_delete | durable | internal |
+-------+--------------------+---------+-------------+---------+----------+
| /     |                    | direct  | False       | True    | False    |
| /     | kowalski           | topic   | False       | True    | False    |
+-------+--------------------+---------+-------------+---------+----------+

Here is my queue:

eric@dev ~ $ sudo python rabbitmqadmin list queues
+-------+----------+-------------+-----------+---------+------------------------+---------------------+--------+----------+----------------+-------------------------+---------------------+--------+---------+
| vhost |   name   | auto_delete | consumers | durable | exclusive_consumer_tag |     idle_since      | memory | messages | messages_ready | messages_unacknowledged |        node         | policy | status  |
+-------+----------+-------------+-----------+---------+------------------------+---------------------+--------+----------+----------------+-------------------------+---------------------+--------+---------+
| /     | myqueue  | False       | 0         | True    |                        | 2014-09-10 13:32:18 | 13760  | 0        | 0              | 0                       |rabbit@ip-11-1-52-125|        | running |
+-------+----------+-------------+-----------+---------+------------------------+---------------------+--------+----------+----------------+-------------------------+---------------------+--------+---------+

Cram some items into myqueue:

curl -i -u guest:guest http://localhost:15672/api/exchanges/%2f/kowalski/publish -d '{"properties":{},"routing_key":"abcxyz","payload":"foobar","payload_encoding":"string"}'
HTTP/1.1 200 OK
Server: MochiWeb/1.1 WebMachine/1.10.0 (never breaks eye contact)
Date: Wed, 10 Sep 2014 17:46:59 GMT
content-type: application/json
Content-Length: 15
Cache-Control: no-cache

{"routed":true}

RabbitMQ see messages in queue:

eric@dev ~ $ sudo python rabbitmqadmin get queue=myqueue requeue=true count=10
+-------------+----------+---------------+---------------------------------------+---------------+------------------+------------+-------------+
| routing_key | exchange | message_count |                        payload        | payload_bytes | payload_encoding | properties | redelivered |
+-------------+----------+---------------+---------------------------------------+---------------+------------------+------------+-------------+
| abcxyz      | kowalski | 10            | foobar                                | 6             | string           |            | True        |
| abcxyz      | kowalski | 9             | {'testdata':'test'}                   | 19            | string           |            | True        |
| abcxyz      | kowalski | 8             | {'mykey':'myvalue'}                   | 19            | string           |            | True        |
| abcxyz      | kowalski | 7             | {'mykey':'myvalue'}                   | 19            | string           |            | True        |
+-------------+----------+---------------+---------------------------------------+---------------+------------------+------------+-------------+

How to get attribute of element from Selenium?

You are probably looking for get_attribute(). An example is shown here as well

def test_chart_renders_from_url(self):
    url = 'http://localhost:8000/analyse/'
    self.browser.get(url)
    org = driver.find_element_by_id('org')
    # Find the value of org?
    val = org.get_attribute("attribute name")

git diff file against its last change

If you are fine using a graphical tool this works very well:

gitk <file>

gitk now shows all commits where the file has been updated. Marking a commit will show you the diff against the previous commit in the list. This also works for directories, but then you also get to select the file to diff for the selected commit. Super useful!

Drop a temporary table if it exists

Check for the existence by retrieving its object_id:

if object_id('tempdb..##clients_keyword') is not null
    drop table ##clients_keyword

C++, How to determine if a Windows Process is running?

While writing a monitoring tool, i took a slightly different approach.

It felt a bit wasteful to spin up an extra thread just to use WaitForSingleObject or even the RegisterWaitForSingleObject (which does that for you). Since in my case i don't need to know the exact instant a process has closed, just that it indeed HAS closed.

I'm using the GetProcessTimes() instead:

https://msdn.microsoft.com/en-us/library/windows/desktop/ms683223(v=vs.85).aspx

GetProcessTimes() will return a FILETIME struct for the process's ExitTime only if the process has actually exited. So is just a matter of checking if the ExitTime struct is populated and if the time isn't 0;

This solution SHOULD account the case where a process has been killed but it's PID was reused by another process. GetProcessTimes needs a handle to the process, not the PID. So the OS should know that the handle is to a process that was running at some point, but not any more, and give you the exit time.

Relying on the ExitCode felt dirty :/

How do I get the old value of a changed cell in Excel VBA?

Private Sub Worksheet_Change(ByVal Target As Range)
vNEW = Target.Value
aNEW = Target.Address
Application.EnableEvents = False
Application.Undo
vOLD = Target.Value
Target.Value = vNEW
Application.EnableEvents = True
End Sub

"Cannot instantiate the type..."

You can use

Queue thequeue = new linkedlist();

or

Queue thequeue = new Priorityqueue();

Reason: Queue is an interface. So you can instantiate only its concrete subclass.

NodeJS w/Express Error: Cannot GET /

I had the same problem, so here's what I came up with. This is what my folder structure looked like when I ran node server.js

app/
  index.html
  server.js

After printing out the __dirname path, I realized that the __dirname path was where my server was running (app/).

So, the answer to your question is this:

If your server.js file is in the same folder as the files you are trying to render, then

app.use(express.static(__dirname + '/default.htm'));

should actually be

app.use(express.static(__dirname));

The only time you would want to use the original syntax that you had would be if you had a folder tree like so:

app/
  index.html
server.js

where index.html is in the app/ directory, whereas server.js is in the root directory (i.e. the same level as the app/ directory).

Overall, your code could look like:

var express = require('express');

var app = express();

app.use(express.static(__dirname));

app.listen(process.env.PORT);

How can I check if char* variable points to empty string?

Give it a chance:

Try getting string via function gets(string) then check condition as if(string[0] == '\0')

How can I verify if a Windows Service is running

I guess something like this would work:

Add System.ServiceProcess to your project references (It's on the .NET tab).

using System.ServiceProcess;

ServiceController sc = new ServiceController(SERVICENAME);

switch (sc.Status)
{
    case ServiceControllerStatus.Running:
        return "Running";
    case ServiceControllerStatus.Stopped:
        return "Stopped";
    case ServiceControllerStatus.Paused:
        return "Paused";
    case ServiceControllerStatus.StopPending:
        return "Stopping";
    case ServiceControllerStatus.StartPending:
        return "Starting";
    default:
        return "Status Changing";
}

Edit: There is also a method sc.WaitforStatus() that takes a desired status and a timeout, never used it but it may suit your needs.

Edit: Once you get the status, to get the status again you will need to call sc.Refresh() first.

Reference: ServiceController object in .NET.

Bind event to right mouse click

There is no built-in oncontextmenu event handler in jQuery, but you can do something like this:

$(document).ready(function(){ 
  document.oncontextmenu = function() {return false;};

  $(document).mousedown(function(e){ 
    if( e.button == 2 ) { 
      alert('Right mouse button!'); 
      return false; 
    } 
    return true; 
  }); 
});

Basically I cancel the oncontextmenu event of the DOM element to disable the browser context menu, and then I capture the mousedown event with jQuery, and there you can know in the event argument which button has been pressed.

You can try the above example here.

Access denied for user 'root'@'localhost' (using password: Yes) after password reset LINUX

I was able to solve this problem by executing this statement

sudo dpkg-reconfigure mysql-server-5.5

Which will change the root password.

Stop and Start a service via batch or cmd file?

Using the return codes from net start and net stop seems like the best method to me. Try a look at this: Net Start return codes.

Difference between @Mock and @InjectMocks

Many people have given a great explanation here about @Mock vs @InjectMocks. I like it, but I think our tests and application should be written in such a way that we shouldn't need to use @InjectMocks.

Reference for further reading with examples: https://tedvinke.wordpress.com/2014/02/13/mockito-why-you-should-not-use-injectmocks-annotation-to-autowire-fields/

jquery - fastest way to remove all rows from a very large table

$("#your-table-id").empty();

That's as fast as you get.

python exception message capturing

Use str(ex) to print execption

try:
   #your code
except ex:
   print(str(ex))

JavaScript Array splice vs slice

Splice and Slice both are Javascript Array functions.

Splice vs Slice

  1. The splice() method returns the removed item(s) in an array and slice() method returns the selected element(s) in an array, as a new array object.

  2. The splice() method changes the original array and slice() method doesn’t change the original array.

  3. The splice() method can take n number of arguments and slice() method takes 2 arguments.

Splice with Example

Argument 1: Index, Required. An integer that specifies at what position to add /remove items, Use negative values to specify the position from the end of the array.

Argument 2: Optional. The number of items to be removed. If set to 0(zero), no items will be removed. And if not passed, all item(s) from provided index will be removed.

Argument 3…n: Optional. The new item(s) to be added to the array.

_x000D_
_x000D_
var array=[1,2,3,4,5];_x000D_
console.log(array.splice(2));_x000D_
// shows [3, 4, 5], returned removed item(s) as a new array object._x000D_
 _x000D_
console.log(array);_x000D_
// shows [1, 2], original array altered._x000D_
 _x000D_
var array2=[6,7,8,9,0];_x000D_
console.log(array2.splice(2,1));_x000D_
// shows [8]_x000D_
 _x000D_
console.log(array2.splice(2,0));_x000D_
//shows [] , as no item(s) removed._x000D_
 _x000D_
console.log(array2);_x000D_
// shows [6,7,9,0]
_x000D_
_x000D_
_x000D_

Slice with Example

Argument 1: Required. An integer that specifies where to start the selection (The first element has an index of 0). Use negative numbers to select from the end of an array.

Argument 2: Optional. An integer that specifies where to end the selection but does not include. If omitted, all elements from the start position and to the end of the array will be selected. Use negative numbers to select from the end of an array.

_x000D_
_x000D_
var array=[1,2,3,4,5]_x000D_
console.log(array.slice(2));_x000D_
// shows [3, 4, 5], returned selected element(s)._x000D_
 _x000D_
console.log(array.slice(-2));_x000D_
// shows [4, 5], returned selected element(s)._x000D_
console.log(array);_x000D_
// shows [1, 2, 3, 4, 5], original array remains intact._x000D_
 _x000D_
var array2=[6,7,8,9,0];_x000D_
console.log(array2.slice(2,4));_x000D_
// shows [8, 9]_x000D_
 _x000D_
console.log(array2.slice(-2,4));_x000D_
// shows [9]_x000D_
 _x000D_
console.log(array2.slice(-3,-1));_x000D_
// shows [8, 9]_x000D_
 _x000D_
console.log(array2);_x000D_
// shows [6, 7, 8, 9, 0]
_x000D_
_x000D_
_x000D_

How to open a local disk file with JavaScript?

Because I have no life and I want those 4 reputation points so I can show my love to (upvote answers by) people who are actually good at coding I've shared my adaptation of Paolo Moretti's code. Just use openFile(function to be executed with file contents as first parameter).

_x000D_
_x000D_
function dispFile(contents) {_x000D_
  document.getElementById('contents').innerHTML=contents_x000D_
}_x000D_
function clickElem(elem) {_x000D_
 // Thx user1601638 on Stack Overflow (6/6/2018 - https://stackoverflow.com/questions/13405129/javascript-create-and-save-file )_x000D_
 var eventMouse = document.createEvent("MouseEvents")_x000D_
 eventMouse.initMouseEvent("click", true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null)_x000D_
 elem.dispatchEvent(eventMouse)_x000D_
}_x000D_
function openFile(func) {_x000D_
 readFile = function(e) {_x000D_
  var file = e.target.files[0];_x000D_
  if (!file) {_x000D_
   return;_x000D_
  }_x000D_
  var reader = new FileReader();_x000D_
  reader.onload = function(e) {_x000D_
   var contents = e.target.result;_x000D_
   fileInput.func(contents)_x000D_
   document.body.removeChild(fileInput)_x000D_
  }_x000D_
  reader.readAsText(file)_x000D_
 }_x000D_
 fileInput = document.createElement("input")_x000D_
 fileInput.type='file'_x000D_
 fileInput.style.display='none'_x000D_
 fileInput.onchange=readFile_x000D_
 fileInput.func=func_x000D_
 document.body.appendChild(fileInput)_x000D_
 clickElem(fileInput)_x000D_
}
_x000D_
Click the button then choose a file to see its contents displayed below._x000D_
<button onclick="openFile(dispFile)">Open a file</button>_x000D_
<pre id="contents"></pre>
_x000D_
_x000D_
_x000D_

How To change the column order of An Existing Table in SQL Server 2008

SQL query to change the id column into first:

ALTER TABLE `student` CHANGE `id` `id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT FIRST;

or by using:

ALTER TABLE `student` CHANGE `id` `id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT AFTER 'column_name' 

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

This jQuery-based answer posted by @user110902 was useful for me. However, I improved it a little to prevent a flaw mentioned in @B_N 's comment: it failed detecting CapsLock while you press Shift:

$('#example').keypress(function(e) { 
    var s = String.fromCharCode( e.which );
    if (( s.toUpperCase() === s && s.toLowerCase() !== s && !e.shiftKey )
    ||  ( s.toLowerCase() === s && s.toUpperCase() !== s && e.shiftKey )) {
        alert('caps is on');
    }
});

Like this, it will work even while pressing Shift.

Create an Android GPS tracking application

Basically you need following things to make location detector android app

Now if you write each of these module yourself then it needs much time and efforts. So it would be better to use ready resources that are being maintained already.

Using all these resources, you will be able to create an flawless android location detection app.

1. Location Listening

You will first need to listen for current location of user. You can use any of below libraries to quick start.

Google Play Location Samples

This library provide last known location, location updates

Location Manager

With this library you just need to provide a Configuration object with your requirements, and you will receive a location or a fail reason with all the stuff are described above handled.

Live Location Sharing

Use this open source repo of the Hypertrack Live app to build live location sharing experience within your app within a few hours. HyperTrack Live app helps you share your Live Location with friends and family through your favorite messaging app when you are on the way to meet up. HyperTrack Live uses HyperTrack APIs and SDKs.

2. Markers Library

Google Maps Android API utility library

  • Marker clustering — handles the display of a large number of points
  • Heat maps — display a large number of points as a heat map
  • IconGenerator — display text on your Markers
  • Poly decoding and encoding — compact encoding for paths, interoperability with Maps API web services
  • Spherical geometry — for example: computeDistance, computeHeading, computeArea
  • KML — displays KML data
  • GeoJSON — displays and styles GeoJSON data

3. Polyline Libraries

DrawRouteMaps

If you want to add route maps feature in your apps you can use DrawRouteMaps to make you work more easier. This is lib will help you to draw route maps between two point LatLng.

trail-android

Simple, smooth animation for route / polylines on google maps using projections. (WIP)

Google-Directions-Android

This project allows you to calculate the direction between two locations and display the route on a Google Map using the Google Directions API.

A map demo app for quick start with maps

Python equivalent of D3.js

You could use d3py a python module that generate xml pages embedding d3.js script. For example :

import d3py
import networkx as nx

import logging
logging.basicConfig(level=logging.DEBUG)

G = nx.Graph()
G.add_edge(1,2)
G.add_edge(1,3)
G.add_edge(3,2)
G.add_edge(3,4)
G.add_edge(4,2)

# use 'with' if you are writing a script and want to serve this up forever
with d3py.NetworkXFigure(G, width=500, height=500) as p:
    p += d3py.ForceLayout()
    p.show()

BasicHttpBinding vs WsHttpBinding vs WebHttpBinding

You're comparing apples to oranges here:

  • webHttpBinding is the REST-style binding, where you basically just hit a URL and get back a truckload of XML or JSON from the web service

  • basicHttpBinding and wsHttpBinding are two SOAP-based bindings which is quite different from REST. SOAP has the advantage of having WSDL and XSD to describe the service, its methods, and the data being passed around in great detail (REST doesn't have anything like that - yet). On the other hand, you can't just browse to a wsHttpBinding endpoint with your browser and look at XML - you have to use a SOAP client, e.g. the WcfTestClient or your own app.

So your first decision must be: REST vs. SOAP (or you can expose both types of endpoints from your service - that's possible, too).

Then, between basicHttpBinding and wsHttpBinding, there differences are as follows:

  • basicHttpBinding is the very basic binding - SOAP 1.1, not much in terms of security, not much else in terms of features - but compatible to just about any SOAP client out there --> great for interoperability, weak on features and security

  • wsHttpBinding is the full-blown binding, which supports a ton of WS-* features and standards - it has lots more security features, you can use sessionful connections, you can use reliable messaging, you can use transactional control - just a lot more stuff, but wsHttpBinding is also a lot *heavier" and adds a lot of overhead to your messages as they travel across the network

For an in-depth comparison (including a table and code examples) between the two check out this codeproject article: Differences between BasicHttpBinding and WsHttpBinding

Get top n records for each group of grouped results

Try this:

SELECT a.person, a.group, a.age FROM person AS a WHERE 
(SELECT COUNT(*) FROM person AS b 
WHERE b.group = a.group AND b.age >= a.age) <= 2 
ORDER BY a.group ASC, a.age DESC

DEMO

How to unsubscribe to a broadcast event in angularJS. How to remove function registered via $on

'$on' itself returns function for unregister

 var unregister=  $rootScope.$on('$stateChangeStart',
            function(event, toState, toParams, fromState, fromParams, options) { 
                alert('state changing'); 
            });

you can call unregister() function to unregister that listener

How to resolve this System.IO.FileNotFoundException

I hate to point out the obvious, but System.IO.FileNotFoundException means the program did not find the file you specified. So what you need to do is check what file your code is looking for in production.

To see what file your program is looking for in production (look at the FileName property of the exception), try these techniques:

Then look at the file system on the machine and see if the file exists. Most likely the case is that it doesn't exist.

How to determine a user's IP address in node

I have tried all of them didn't work though,

console.log(clientIp);
console.log(req.ip);

console.log(req.headers['x-forwarded-for']);
console.log(req.connection.remoteAddress);
console.log(req.socket.remoteAddress);
console.log(req.connection.socket.remoteAddress.split(",")[0]);

When running an Express app behind a proxy for me Nginx, you have to set the application variable trust proxy to true. Express offers a few other trust proxy values which you can review in their documentation, but below steps worked for me.

  1. app.set('trust proxy', true) in your Express app.

app.set('trust proxy', true);

  1. Add proxy_set_header X-Forwarded-For $remote_addr in the Nginx configuration for your server block.
  location /  {
                proxy_pass    http://localhost:3001;
                proxy_http_version 1.1;
                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection 'upgrade';
                proxy_set_header Host $host;
                proxy_set_header X-Forwarded-For $remote_addr;  # this line
                proxy_cache_bypass $http_upgrade; 
        }
  1. You can now read off the client’s IP address from the req.header('x-forwarded-for') or req.connection.remoteAddress; Full code for ipfilter
module.exports =  function(req, res, next) {
    let enable = true; // true/false
    let blacklist = ['x.x.x.x'];
    let whitelist = ['x.x.x.x'];
    let clientIp = req.header('x-forwarded-for') || req.connection.remoteAddress;
    if (!clientIp) {
        return res.json('Error');
    }
    if (enable
        && paths.some((path) => (path === req.originalUrl))) {

        let blacklist = blacklist || [];
        if (blacklist.some((ip) => clientIp.match(ip) !== null)) {
            return res.json({ status: 401, error: 'Your IP is black-listed !'});
        }
        let whitelist = whitelist || [];
        if (whitelist.length === 0 || whitelist.some((ip) => clientIp.match(ip) !== null)) {
            next();
            return;
        } else {
            return res.json({ status: 401, error: 'Your IP is not listed !'});
        }
    }
    next();
};

Heroku + node.js error (Web process failed to bind to $PORT within 60 seconds of launch)

Even if I'm too late but this might help someone who will get stuck too in the coming days. I faced the same issue but my problem was running many commands with npm start. I was running create tables and insert data before start the app and make 10 sec exceeds before running. So I removed those commands and problem solved.

Thanks

Get current URL from IFRAME

If your iframe is from another domain, (cross domain), the other answers are not going to help you... you will simply need to use this:

var currentUrl = document.referrer;

and - here you've got the main url!

Toggle show/hide on click with jQuery

$(document).ready( function(){
  $("button").click(function(){
    $("p").toggle(1000,'linear');
  });
});

Live Demo

How to create a BKS (BouncyCastle) format Java Keystore that contains a client certificate chain

Detailed Step by Step instructions I followed to achieve this

  • Download bouncycastle JAR from http://repo2.maven.org/maven2/org/bouncycastle/bcprov-ext-jdk15on/1.46/bcprov-ext-jdk15on-1.46.jar or take it from the "doc" folder.
  • Configure BouncyCastle for PC using one of the below methods.
    • Adding the BC Provider Statically (Recommended)
      • Copy the bcprov-ext-jdk15on-1.46.jar to each
        • D:\tools\jdk1.5.0_09\jre\lib\ext (JDK (bundled JRE)
        • D:\tools\jre1.5.0_09\lib\ext (JRE)
        • C:\ (location to be used in env variable)
      • Modify the java.security file under
        • D:\tools\jdk1.5.0_09\jre\lib\security
        • D:\tools\jre1.5.0_09\lib\security
        • and add the following entry
          • security.provider.7=org.bouncycastle.jce.provider.BouncyCastleProvider
      • Add the following environment variable in "User Variables" section
        • CLASSPATH=%CLASSPATH%;c:\bcprov-ext-jdk15on-1.46.jar
    • Add bcprov-ext-jdk15on-1.46.jar to CLASSPATH of your project and Add the following line in your code
      • Security.addProvider(new BouncyCastleProvider());
  • Generate the Keystore using Bouncy Castle
    • Run the following command
      • keytool -genkey -alias myproject -keystore C:/myproject.keystore -storepass myproject -storetype BKS -provider org.bouncycastle.jce.provider.BouncyCastleProvider
    • This generates the file C:\myproject.keystore
    • Run the following command to check if it is properly generated or not
      • keytool -list -keystore C:\myproject.keystore -storetype BKS
  • Configure BouncyCastle for TOMCAT

    • Open D:\tools\apache-tomcat-6.0.35\conf\server.xml and add the following entry

      • <Connector port="8443" keystorePass="myproject" alias="myproject" keystore="c:/myproject.keystore" keystoreType="BKS" SSLEnabled="true" clientAuth="false" protocol="HTTP/1.1" scheme="https" secure="true" sslProtocol="TLS" sslImplementationName="org.bouncycastle.jce.provider.BouncyCastleProvider"/>
    • Restart the server after these changes.

  • Configure BouncyCastle for Android Client
    • No need to configure since Android supports Bouncy Castle Version 1.46 internally in the provided "android.jar".
    • Just implement your version of HTTP Client (MyHttpClient.java can be found below) and set the following in code
      • SSLSocketFactory.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
    • If you don't do this, it gives an exception as below
      • javax.net.ssl.SSLException: hostname in certificate didn't match: <192.168.104.66> !=
    • In production mode, change the above code to
      • SSLSocketFactory.setHostnameVerifier(SSLSocketFactory.STRICT_HOSTNAME_VERIFIER);

MyHttpClient.java

package com.arisglobal.aglite.network;

import java.io.InputStream;
import java.security.KeyStore;

import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.conn.scheme.PlainSocketFactory;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.conn.SingleClientConnManager;

import com.arisglobal.aglite.activity.R;

import android.content.Context;

public class MyHttpClient extends DefaultHttpClient {

    final Context context;

    public MyHttpClient(Context context) {
        this.context = context;
    }

    @Override
    protected ClientConnectionManager createClientConnectionManager() {
        SchemeRegistry registry = new SchemeRegistry();

        registry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));

        // Register for port 443 our SSLSocketFactory with our keystore to the ConnectionManager
        registry.register(new Scheme("https", newSslSocketFactory(), 443));
        return new SingleClientConnManager(getParams(), registry);
    }

    private SSLSocketFactory newSslSocketFactory() {
        try {
            // Get an instance of the Bouncy Castle KeyStore format
            KeyStore trusted = KeyStore.getInstance("BKS");

            // Get the raw resource, which contains the keystore with your trusted certificates (root and any intermediate certs)
            InputStream in = context.getResources().openRawResource(R.raw.aglite);
            try {
                // Initialize the keystore with the provided trusted certificates.
                // Also provide the password of the keystore
                trusted.load(in, "aglite".toCharArray());
            } finally {
                in.close();
            }

            // Pass the keystore to the SSLSocketFactory. The factory is responsible for the verification of the server certificate.
            SSLSocketFactory sf = new SSLSocketFactory(trusted);

            // Hostname verification from certificate
            // http://hc.apache.org/httpcomponents-client-ga/tutorial/html/connmgmt.html#d4e506
            sf.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
            return sf;
        } catch (Exception e) {
            throw new AssertionError(e);
        }
    }
}

How to invoke the above code in your Activity class:

DefaultHttpClient client = new MyHttpClient(getApplicationContext());
HttpResponse response = client.execute(...);

Turning off auto indent when pasting text into vim

When working inside a terminal the vim-bracketed-paste vim plugin will automatically handle pastes without needing any keystrokes before or after the paste.

It works by detecting bracketed paste mode which is an escape sequence sent by "modern" x-term compatible terminals like iTerm2, gnome-terminal, and other terminals using libvte. As an added bonus it works also for tmux sessions. I am using it successfully with iTerm2 on a Mac connecting to a linux server and using tmux.

The controller for path was not found or does not implement IController

Also, for those who the solution above didn't work, here's is what worked for me:

I have a solution with multiple projects. All projects were in MVC3. I installed Visual Studio 2012 in my machine and it seems that some projects were automatically upgraded to MVC4.

I got this problem

The controller for path '/etc/etc' was not found or does not implement IController

because the project that handled that route was pointing to MVC4.

I had to manually update their references to use MVC3. You can also do that by opening the .csproj file with a text editor. Find the reference to MVC3 and remove this line:

<SpecificVersion>False</SpecificVersion>

Spring MVC - How to return simple String as JSON in Rest Controller

Add produces = "application/json" in @RequestMapping annotation like:

@RequestMapping(value = "api/login", method = RequestMethod.GET, produces = "application/json")

Hint: As a return value, i recommend to use ResponseEntity<List<T>> type. Because the produced data in JSON body need to be an array or an object according to its specifications, rather than a single simple string. It may causes problems sometimes (e.g. Observables in Angular2).

Difference:

returned String as json: "example"

returned List<String> as json: ["example"]

Maximum Java heap size of a 32-bit JVM on a 64-bit OS

The JROCKIT JVM currently owned by Oracle supports non-contiguous heap usage, thus allowing the 32 bit JVM to access more then 3.8 GB of memory when the JVM is running on a 64 bit windows OS. (2.8 GB when running on a 32 bit OS).

http://blogs.oracle.com/jrockit/entry/how_to_get_almost_3_gb_heap_on_windows

The JVM can be freely downloaded (registration required) at

http://www.oracle.com/technetwork/middleware/jrockit/downloads/index.html

Get Wordpress Category from Single Post

<div class="post_category">
        <?php $category = get_the_category();
             $allcategory = get_the_category(); 
        foreach ($allcategory as $category) {
        ?>
           <a class="btn"><?php echo $category->cat_name;; ?></a>
        <?php 
        }
        ?>
 </div>

How to implement if-else statement in XSLT?

You have to reimplement it using <xsl:choose> tag:

       <xsl:choose>
         <xsl:when test="$CreatedDate > $IDAppendedDate">
           <h2> mooooooooooooo </h2>
         </xsl:when>
         <xsl:otherwise>
          <h2> dooooooooooooo </h2>
         </xsl:otherwise>
       </xsl:choose>

Compare two files and write it to "match" and "nomatch" files

In Eztrieve it's really easy, below is an example how you could code it:

//STEP01   EXEC PGM=EZTPA00                                        
//FILEA    DD DSN=FILEA,DISP=SHR   
//FILEB    DD DSN=FILEB,DISP=SHR
//FILEC    DD DSN=FILEC.DIF,    
//            DISP=(NEW,CATLG,DELETE),                             
//            SPACE=(CYL,(100,50),RLSE),                           
//            UNIT=PRMDA,                                          
//            DCB=(RECFM=FB,LRECL=5200,BLKSIZE=0)                  
//SYSOUT   DD SYSOUT=*                                             
//SRTMSG   DD SYSOUT=*                                             
//SYSPRINT DD SYSOUT=*                                             
//SYSIN    DD *                                                    
 FILE FILEA                                                        
   FA-KEY       1   7 A                                         
   FA-REC1      8  10 A
   FA-REC2     18   5 A

 FILE FILEB                                                        
   FB-KEY       1   7 A                                         
   FB-REC1      8  10 A                                         
   FB-REC2     18   5 A                                         

 FILE FILEC                                                        

 FILE FILED                                                        
   FD-KEY       1   7 A                                         
   FD-REC1      8  10 A                                         
   FD-REC2     18   5 A                                         


 JOB INPUT (FILEA KEY FA-KEY FILEB KEY FB-KEY)                     
   IF MATCHED            
      FD-KEY   =  FB-KEY                                      
      FD-REC1  =  FA-REC1
      FD-REC2  =  FB-REC2
      PUT FILED
   ELSE
      IF FILEA
         PUT FILEC FROM FILEA                                         
      ELSE
         PUT FILEC FROM FILEB
      END-IF                                         
   END-IF                                                          
/*                       

How do I pass variables and data from PHP to JavaScript?

As per your code

<$php
     $val = $myService->getValue(); // Makes an API and database call
     echo '<span id="value">'.$val.'</span>';
$>

Now you can get value using DOM, use innerHTML of span id, in this case you don't need to do any call to server, or Ajax or another thing.

Your page will print it using PHP, and you JavaScript will get value using DOM.

jquery simple image slideshow tutorial

I dont know why you havent marked on of these gr8 answers... here is another option which would enable you and anyone else visiting to control transition speed and pause time

JAVASCRIPT

$(function () {

    /* SET PARAMETERS */
    var change_img_time     = 5000; 
    var transition_speed    = 100;

    var simple_slideshow    = $("#exampleSlider"),
        listItems           = simple_slideshow.children('li'),
        listLen             = listItems.length,
        i                   = 0,

        changeList = function () {

            listItems.eq(i).fadeOut(transition_speed, function () {
                i += 1;
                if (i === listLen) {
                    i = 0;
                }
                listItems.eq(i).fadeIn(transition_speed);
            });

        };

    listItems.not(':first').hide();
    setInterval(changeList, change_img_time);

});

.

HTML

<ul id="exampleSlider">
    <li><img src="http://placehold.it/500x250" alt="" /></li>
    <li><img src="http://placehold.it/500x250" alt="" /></li>
    <li><img src="http://placehold.it/500x250" alt="" /></li>
    <li><img src="http://placehold.it/500x250" alt="" /></li>
</ul>

.
If your keeping this simple its easy to keep it resposive
best to visit the: DEMO

.
If you want something with special transition FX (Still responsive) - check this out
DEMO WITH SPECIAL FX

Pass parameter to controller from @Html.ActionLink MVC 4

I have to pass two parameters like:

/Controller/Action/Param1Value/Param2Value

This way:

@Html.ActionLink(
    linkText,
    actionName,
    controllerName,
    routeValues: new {
        Param1Name= Param1Value, 
        Param2Name = Param2Value 
    },
    htmlAttributes: null
)

will generate this url

/Controller/Action/Param1Value?Param2Name=Param2Value

I used a workaround method by merging parameter two in parameter one and I get what I wanted:

@Html.ActionLink(
    linkText,
    actionName,
    controllerName,
    routeValues: new {
        Param1Name= "Param1Value / Param2Value" ,      
    },
    htmlAttributes: null
)

And I get :

/Controller/Action/Param1Value/Param2Value

How do I clear all options in a dropdown box?

var select = document.getElementById("DropList");
var length = select.options.length;
for (i = 0; i < length; i++) {
  select.options[i].remove();
}

Hope, this code will helps you

Jquery - How to get the style display attribute "none / block"

You could try:

$j('div.contextualError.ckgcellphone').css('display')

How to delete duplicates on a MySQL table?

This here will make the column column_name into a primary key, and in the meantime ignore all errors. So it will delete the rows with a duplicate value for column_name.

ALTER IGNORE TABLE `table_name` ADD PRIMARY KEY (`column_name`);

jQuery - If element has class do this

First, you're missing some parentheses in your conditional:

if ($("#about").hasClass("opened")) {
  $("#about").animate({right: "-700px"}, 2000);
}

But you can also simplify this to:

$('#about.opened').animate(...);

If #about doesn't have the opened class, it won't animate.

If the problem is with the animation itself, we'd need to know more about your element positioning (absolute? absolute inside relative parent? does the parent have layout?)

Simple URL GET/POST function in Python

requests

https://github.com/kennethreitz/requests/

Here's a few common ways to use it:

import requests
url = 'https://...'
payload = {'key1': 'value1', 'key2': 'value2'}

# GET
r = requests.get(url)

# GET with params in URL
r = requests.get(url, params=payload)

# POST with form-encoded data
r = requests.post(url, data=payload)

# POST with JSON 
import json
r = requests.post(url, data=json.dumps(payload))

# Response, status etc
r.text
r.status_code

httplib2

https://github.com/jcgregorio/httplib2

>>> from httplib2 import Http
>>> from urllib import urlencode
>>> h = Http()
>>> data = dict(name="Joe", comment="A test comment")
>>> resp, content = h.request("http://bitworking.org/news/223/Meet-Ares", "POST", urlencode(data))
>>> resp
{'status': '200', 'transfer-encoding': 'chunked', 'vary': 'Accept-Encoding,User-Agent',
 'server': 'Apache', 'connection': 'close', 'date': 'Tue, 31 Jul 2007 15:29:52 GMT', 
 'content-type': 'text/html'}

How to change the background color of Action Bar's Option Menu in Android 4.2?

Try this code. Add this snippet to your res>values>styles.xml

<style name="AppTheme" parent="AppBaseTheme">
    <item name="android:actionBarWidgetTheme">@style/Theme.stylingactionbar.widget</item>
</style>
<style name="PopupMenu" parent="@android:style/Widget.Holo.ListPopupWindow">
    <item name="android:popupBackground">@color/DarkSlateBlue</item>
 <!-- for @color you have to create a color.xml in res > values -->
</style>
<style name="Theme.stylingactionbar.widget" parent="@android:style/Theme.Holo">
    <item name="android:popupMenuStyle">@style/PopupMenu</item>
</style>

And in Manifest.xml add below snippet under application

 <application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"

     android:theme="@style/AppTheme"  >

How do I recursively delete a directory and its entire contents (files + sub dirs) in PHP?

Enhanced @Artefacto 's solution - corrected typos and simplified code, working for both - empty && non-empty directories .

  function recursive_rmdir($dir) { 
    if( is_dir($dir) ) { 
      $objects = array_diff( scandir($dir), array('..', '.') );
      foreach ($objects as $object) { 
        $objectPath = $dir."/".$object;
        if( is_dir($objectPath) )
          recursive_rmdir($objectPath);
        else
          unlink($objectPath); 
      } 
      rmdir($dir); 
    } 
  }

How can I make Bootstrap columns all the same height?

You can use below code

var heights = $(".row > div").map(function() {
    return $(this).height();
}).get(),
maxHeight = Math.max.apply(null, heights);
$(".row > div").height(maxHeight);

How do I verify that an Android apk is signed with a release certificate?

Use this command, (go to java < jdk < bin path in cmd prompt)

$ jarsigner -verify -verbose -certs my_application.apk

If you see "CN=Android Debug", this means the .apk was signed with the debug key generated by the Android SDK (means it is unsigned), otherwise you will find something for CN. For more details see: http://developer.android.com/guide/publishing/app-signing.html

Best way to style a TextBox in CSS

You could target all text boxes with input[type=text] and then explicitly define the class for the textboxes who need it.

You can code like below :

_x000D_
_x000D_
input[type=text] {_x000D_
  padding: 0;_x000D_
  height: 30px;_x000D_
  position: relative;_x000D_
  left: 0;_x000D_
  outline: none;_x000D_
  border: 1px solid #cdcdcd;_x000D_
  border-color: rgba(0, 0, 0, .15);_x000D_
  background-color: white;_x000D_
  font-size: 16px;_x000D_
}_x000D_
_x000D_
.advancedSearchTextbox {_x000D_
  width: 526px;_x000D_
  margin-right: -4px;_x000D_
}
_x000D_
<input type="text" class="advancedSearchTextBox" />
_x000D_
_x000D_
_x000D_

Using crontab to execute script every minute and another every 24 hours

every minute:

* * * * * /path/to/php /var/www/html/a.php

every 24hours (every midnight):

0 0 * * * /path/to/php /var/www/html/reset.php

See this reference for how crontab works: http://adminschoice.com/crontab-quick-reference, and this handy tool to build cron jobx: http://www.htmlbasix.com/crontab.shtml

How to assign an action for UIImageView object in Swift

You can put a UIButton with a transparent background over top of the UIImageView, and listen for a tap on the button before loading the image

Pandas: sum DataFrame rows for given columns

If you have just a few columns to sum, you can write:

df['e'] = df['a'] + df['b'] + df['d']

This creates new column e with the values:

   a  b   c  d   e
0  1  2  dd  5   8
1  2  3  ee  9  14
2  3  4  ff  1   8

For longer lists of columns, EdChum's answer is preferred.

Removing space from dataframe columns in pandas

  • To remove white spaces:

1) To remove white space everywhere:

df.columns = df.columns.str.replace(' ', '')

2) To remove white space at the beginning of string:

df.columns = df.columns.str.lstrip()

3) To remove white space at the end of string:

df.columns = df.columns.str.rstrip()

4) To remove white space at both ends:

df.columns = df.columns.str.strip()
  • To replace white spaces with other characters (underscore for instance):

5) To replace white space everywhere

df.columns = df.columns.str.replace(' ', '_')

6) To replace white space at the beginning:

df.columns = df.columns.str.replace('^ +', '_')

7) To replace white space at the end:

df.columns = df.columns.str.replace(' +$', '_')

8) To replace white space at both ends:

df.columns = df.columns.str.replace('^ +| +$', '_')

All above applies to a specific column as well, assume you have a column named col, then just do:

df[col] = df[col].str.strip()  # or .replace as above

Undefined index error PHP

this error occurred sometime method attribute ( valid passing method ) Error option : method="get" but called by $Fname = $_POST["name"]; or

       method="post" but  called by  $Fname = $_GET["name"];

More info visit http://www.doordie.co.in/index.php

How to check if a variable is an integer or a string?

if you want to check what it is:

>>>isinstance(1,str)
False
>>>isinstance('stuff',str)
True
>>>isinstance(1,int)
True
>>>isinstance('stuff',int)
False

if you want to get ints from raw_input

>>>x=raw_input('enter thing:')
enter thing: 3
>>>try: x = int(x)
   except: pass

>>>isinstance(x,int)
True

Creating a static class with no instances

There are two ways to do that (Python 2.6+):

static method

class Klass(object):
    @staticmethod
    def static_method():
        print "Hello World"

Klass.static_method()

module

your module file, called klass.py

def static_method():
    print "Hello World"

your code:

import klass

klass.static_method()

Buiding Hadoop with Eclipse / Maven - Missing artifact jdk.tools:jdk.tools:jar:1.6

I use below in my MR project.

<exclusions>
                <exclusion>
                    <artifactId>jdk.tools</artifactId>
                    <groupId>jdk.tools</groupId>
                </exclusion>
</exclusions>

Check if cookies are enabled

it is easy to detect whether the cookies is enabled:

  1. set a cookie.
  2. get the cookie

if you can get the cookie you set, the cookie is enabled, otherwise not.

BTW: it is a bad idea to Embedding the session id in the links and forms, it is bad for SEO. In my opinion, it is not very common that people dont want to enable cookies.

jQuery calculate sum of values in all text fields

?

$('.price').blur(function () {
    var sum = 0;
    $('.price').each(function() {
        sum += Number($(this).val());
    });

    // here, you have your sum
});?????????

display: flex not working on Internet Explorer

Am afraid this question has been answered a few times, Pls take a look at the following if it's related

OperationalError, no such column. Django

Deleting all your migrations in the migration folder of your django app, then run makemigrations followed by migrate commands. You should be able to get out of the woods.

What does "int 0x80" mean in assembly code?

int 0x80 is the assembly language instruction that is used to invoke system calls in Linux on x86 (i.e., Intel-compatible) processors.

http://www.linfo.org/int_0x80.html

HTML Input Box - Disable

<input type="text" disabled="disabled" />

See the W3C HTML Specification on the input tag for more information.

Is there a numpy builtin to reject outliers from a list

For a set of images (each image has 3 dimensions), where I wanted to reject outliers for each pixel I used:

mean = np.mean(imgs, axis=0)
std = np.std(imgs, axis=0)
mask = np.greater(0.5 * std + 1, np.abs(imgs - mean))
masked = np.multiply(imgs, mask)

Then it is possible to compute the mean:

masked_mean = np.divide(np.sum(masked, axis=0), np.sum(mask, axis=0))

(I use it for Background Subtraction)

How do you use Intent.FLAG_ACTIVITY_CLEAR_TOP to clear the Activity Stack?

@bitestar has the correct solution, but there is one more step:

It was hidden away in the docs, however you must change the launchMode of the Activity to anything other than standard. Otherwise it will be destroyed and recreated instead of being reset to the top.

iPhone system font

If you're doing programatic customisation, don't hard code the system font. Use UIFont systemFontOfSize:, UIFont boldSystemFontOfSize: and UIFont italicSystemFontOfSize (Apple documentation).

This has become especially relevant since iOS 7, which changed the system font to Helvetica Neue.

This has become super especially relevant since iOS 9, which changed the system font again to San Francisco.

addEventListener for keydown on Canvas

Set the tabindex of the canvas element to 1 or something like this

<canvas tabindex='1'></canvas>

It's an old trick to make any element focusable

How to add label in chart.js for pie chart

It is not necessary to use another library like newChart or use other people's pull requests to pull this off. All you have to do is define an options object and add the label wherever and however you want it in the tooltip.

var optionsPie = {
    tooltipTemplate: "<%= label %> - <%= value %>"
}

If you want the tooltip to be always shown you can make some other edits to the options:

 var optionsPie = {
        tooltipEvents: [],
        showTooltips: true,
        onAnimationComplete: function() {
            this.showTooltip(this.segments, true);
        },
        tooltipTemplate: "<%= label %> - <%= value %>"
    }

In your data items, you have to add the desired label property and value and that's all.

data = [
    {
        value: 480000,
        color:"#F7464A",
        highlight: "#FF5A5E",
        label: "Tobacco"
    }
];

Now, all you have to do is pass the options object after the data to the new Pie like this: new Chart(ctx).Pie(data,optionsPie) and you are done.

This probably works best for pies which are not very small in size.

Pie chart with labels

Making a POST call instead of GET using urllib2

Have a read of the urllib Missing Manual. Pulled from there is the following simple example of a POST request.

url = 'http://myserver/post_service'
data = urllib.urlencode({'name' : 'joe', 'age'  : '10'})
req = urllib2.Request(url, data)
response = urllib2.urlopen(req)
print response.read()

As suggested by @Michael Kent do consider requests, it's great.

EDIT: This said, I do not know why passing data to urlopen() does not result in a POST request; It should. I suspect your server is redirecting, or misbehaving.

Decoding base64 in batch

Here's a batch file, called base64encode.bat, that encodes base64.

@echo off
if not "%1" == "" goto :arg1exists
echo usage: base64encode input-file [output-file]
goto :eof
:arg1exists
set base64out=%2
if "%base64out%" == "" set base64out=con 
(
  set base64tmp=base64.tmp
  certutil -encode "%1" %base64tmp% > nul
  findstr /v /c:- %base64tmp%
  erase %base64tmp%
) > %base64out%

Flutter position stack widget in center

Have a look at this solution I came up with

Positioned( child: SizedBox( child: CircularProgressIndicator(), width: 50, height: 50,), left: MediaQuery.of(context).size.width / 2 - 25);

How to close a window using jQuery

You can only use the window.close function when you have opened the window using window.open(), so I use the following function:

function close_window(url){
    var newWindow = window.open('', '_self', ''); //open the current window
    window.close(url);
 }

Can functions be passed as parameters?

Yes, consider some of these examples:

package main

import "fmt"

// convert types take an int and return a string value.
type convert func(int) string

// value implements convert, returning x as string.
func value(x int) string {
    return fmt.Sprintf("%v", x)
}

// quote123 passes 123 to convert func and returns quoted string.
func quote123(fn convert) string {
    return fmt.Sprintf("%q", fn(123))
}

func main() {
    var result string

    result = value(123)
    fmt.Println(result)
    // Output: 123

    result = quote123(value)
    fmt.Println(result)
    // Output: "123"

    result = quote123(func(x int) string { return fmt.Sprintf("%b", x) })
    fmt.Println(result)
    // Output: "1111011"

    foo := func(x int) string { return "foo" }
    result = quote123(foo)
    fmt.Println(result)
    // Output: "foo"

    _ = convert(foo) // confirm foo satisfies convert at runtime

    // fails due to argument type
    // _ = convert(func(x float64) string { return "" })
}

Play: http://play.golang.org/p/XNMtrDUDS0

Tour: https://tour.golang.org/moretypes/25 (Function Closures)

Validate decimal numbers in JavaScript - IsNumeric()

I'd like to add the following:

1. IsNumeric('0x89f') => true
2. IsNumeric('075') => true

Positive hex numbers start with 0x and negative hex numbers start with -0x. Positive oct numbers start with 0 and negative oct numbers start with -0. This one takes most of what has already been mentioned into consideration, but includes hex and octal numbers, negative scientific, Infinity and has removed decimal scientific (4e3.2 is not valid).

function IsNumeric(input){
  var RE = /^-?(0|INF|(0[1-7][0-7]*)|(0x[0-9a-fA-F]+)|((0|[1-9][0-9]*|(?=[\.,]))([\.,][0-9]+)?([eE]-?\d+)?))$/;
  return (RE.test(input));
}

How can I detect when the mouse leaves the window?

If you are using jQuery then how about this short and sweet code -

$(document).mouseleave(function () {
    console.log('out');
});

This event will trigger whenever the mouse is not in your page as you want. Just change the function to do whatever you want.

And you could also use:

$(document).mouseenter(function () {
    console.log('in');
});

To trigger when the mouse enters back to the page again.

Source: https://stackoverflow.com/a/16029966/895724

Pandas timeseries plot setting x-axis major and minor ticks and labels

Both pandas and matplotlib.dates use matplotlib.units for locating the ticks.

But while matplotlib.dates has convenient ways to set the ticks manually, pandas seems to have the focus on auto formatting so far (you can have a look at the code for date conversion and formatting in pandas).

So for the moment it seems more reasonable to use matplotlib.dates (as mentioned by @BrenBarn in his comment).

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt 
import matplotlib.dates as dates

idx = pd.date_range('2011-05-01', '2011-07-01')
s = pd.Series(np.random.randn(len(idx)), index=idx)

fig, ax = plt.subplots()
ax.plot_date(idx.to_pydatetime(), s, 'v-')
ax.xaxis.set_minor_locator(dates.WeekdayLocator(byweekday=(1),
                                                interval=1))
ax.xaxis.set_minor_formatter(dates.DateFormatter('%d\n%a'))
ax.xaxis.grid(True, which="minor")
ax.yaxis.grid()
ax.xaxis.set_major_locator(dates.MonthLocator())
ax.xaxis.set_major_formatter(dates.DateFormatter('\n\n\n%b\n%Y'))
plt.tight_layout()
plt.show()

pandas_like_date_fomatting

(my locale is German, so that Tuesday [Tue] becomes Dienstag [Di])

Difference between onCreate() and onStart()?

Take a look on life cycle of Activity enter image description here

Where

***onCreate()***

Called when the activity is first created. This is where you should do all of your normal static set up: create views, bind data to lists, etc. This method also provides you with a Bundle containing the activity's previously frozen state, if there was one. Always followed by onStart().

***onStart()***

Called when the activity is becoming visible to the user. Followed by onResume() if the activity comes to the foreground, or onStop() if it becomes hidden.

And you can write your simple class to take a look when these methods call

public class TestActivity extends Activity {
    /** Called when the activity is first created. */

    private final static String TAG = "TestActivity";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Log.i(TAG, "On Create .....");
    }
    /* (non-Javadoc)
    * @see android.app.Activity#onDestroy()
    */
    @Override
    protected void onDestroy() { 
        super.onDestroy();
        Log.i(TAG, "On Destroy .....");
    }
    /* (non-Javadoc)
    * @see android.app.Activity#onPause()
    */
    @Override
    protected void onPause() { 
        super.onPause();
        Log.i(TAG, "On Pause .....");
    }

    /* (non-Javadoc)
    * @see android.app.Activity#onRestart()
    */
    @Override
    protected void onRestart() {
        super.onRestart();
        Log.i(TAG, "On Restart .....");
    }

    /* (non-Javadoc)
    * @see android.app.Activity#onResume()
    */
    @Override
    protected void onResume() {
        super.onResume();
        Log.i(TAG, "On Resume .....");
    }

    /* (non-Javadoc)
    * @see android.app.Activity#onStart()
    */
    @Override
    protected void onStart() {
        super.onStart();
        Log.i(TAG, "On Start .....");
    }
    /* (non-Javadoc)
    * @see android.app.Activity#onStop()
    */
    @Override
    protected void onStop() {
        super.onStop();
        Log.i(TAG, "On Stop .....");
    }
}

Hope this will clear your confusion.

And take a look here for details.

Lifecycle Methods in Details is a very good example and demo application, which is a very good article to understand the life cycle.

How to multiply individual elements of a list with a number?

Here is a functional approach using map, itertools.repeat and operator.mul:

import operator
from itertools import repeat


def scalar_multiplication(vector, scalar):
    yield from map(operator.mul, vector, repeat(scalar))

Example of usage:

>>> v = [1, 2, 3, 4]
>>> c = 3
>>> list(scalar_multiplication(v, c))
[3, 6, 9, 12]

How to determine if a point is in a 2D triangle?

I needed point in triangle check in "controlable environment" when you're absolutely sure that triangles will be clockwise. So, I took Perro Azul's jsfiddle and modified it as suggested by coproc for such cases; also removed redundant 0.5 and 2 multiplications because they're just cancel each other.

http://jsfiddle.net/dog_funtom/H7D7g/

_x000D_
_x000D_
var ctx = $("canvas")[0].getContext("2d");_x000D_
var W = 500;_x000D_
var H = 500;_x000D_
_x000D_
var point = {_x000D_
    x: W / 2,_x000D_
    y: H / 2_x000D_
};_x000D_
var triangle = randomTriangle();_x000D_
_x000D_
$("canvas").click(function (evt) {_x000D_
    point.x = evt.pageX - $(this).offset().left;_x000D_
    point.y = evt.pageY - $(this).offset().top;_x000D_
    test();_x000D_
});_x000D_
_x000D_
$("canvas").dblclick(function (evt) {_x000D_
    triangle = randomTriangle();_x000D_
    test();_x000D_
});_x000D_
_x000D_
test();_x000D_
_x000D_
function test() {_x000D_
    var result = ptInTriangle(point, triangle.a, triangle.b, triangle.c);_x000D_
_x000D_
    var info = "point = (" + point.x + "," + point.y + ")\n";_x000D_
    info += "triangle.a = (" + triangle.a.x + "," + triangle.a.y + ")\n";_x000D_
    info += "triangle.b = (" + triangle.b.x + "," + triangle.b.y + ")\n";_x000D_
    info += "triangle.c = (" + triangle.c.x + "," + triangle.c.y + ")\n";_x000D_
    info += "result = " + (result ? "true" : "false");_x000D_
_x000D_
    $("#result").text(info);_x000D_
    render();_x000D_
}_x000D_
_x000D_
function ptInTriangle(p, p0, p1, p2) {_x000D_
    var s = (p0.y * p2.x - p0.x * p2.y + (p2.y - p0.y) * p.x + (p0.x - p2.x) * p.y);_x000D_
    var t = (p0.x * p1.y - p0.y * p1.x + (p0.y - p1.y) * p.x + (p1.x - p0.x) * p.y);_x000D_
_x000D_
    if (s <= 0 || t <= 0) return false;_x000D_
_x000D_
    var A = (-p1.y * p2.x + p0.y * (-p1.x + p2.x) + p0.x * (p1.y - p2.y) + p1.x * p2.y);_x000D_
_x000D_
    return (s + t) < A;_x000D_
}_x000D_
_x000D_
function checkClockwise(p0, p1, p2) {_x000D_
    var A = (-p1.y * p2.x + p0.y * (-p1.x + p2.x) + p0.x * (p1.y - p2.y) + p1.x * p2.y);_x000D_
    return A > 0;_x000D_
}_x000D_
_x000D_
function render() {_x000D_
    ctx.fillStyle = "#CCC";_x000D_
    ctx.fillRect(0, 0, 500, 500);_x000D_
    drawTriangle(triangle.a, triangle.b, triangle.c);_x000D_
    drawPoint(point);_x000D_
}_x000D_
_x000D_
function drawTriangle(p0, p1, p2) {_x000D_
    ctx.fillStyle = "#999";_x000D_
    ctx.beginPath();_x000D_
    ctx.moveTo(p0.x, p0.y);_x000D_
    ctx.lineTo(p1.x, p1.y);_x000D_
    ctx.lineTo(p2.x, p2.y);_x000D_
    ctx.closePath();_x000D_
    ctx.fill();_x000D_
    ctx.fillStyle = "#000";_x000D_
    ctx.font = "12px monospace";_x000D_
    ctx.fillText("1", p0.x, p0.y);_x000D_
    ctx.fillText("2", p1.x, p1.y);_x000D_
    ctx.fillText("3", p2.x, p2.y);_x000D_
}_x000D_
_x000D_
function drawPoint(p) {_x000D_
    ctx.fillStyle = "#F00";_x000D_
    ctx.beginPath();_x000D_
    ctx.arc(p.x, p.y, 5, 0, 2 * Math.PI);_x000D_
    ctx.fill();_x000D_
}_x000D_
_x000D_
function rand(min, max) {_x000D_
    return Math.floor(Math.random() * (max - min + 1)) + min;_x000D_
}_x000D_
_x000D_
function randomTriangle() {_x000D_
    while (true) {_x000D_
        var result = {_x000D_
            a: {_x000D_
                x: rand(0, W),_x000D_
                y: rand(0, H)_x000D_
            },_x000D_
            b: {_x000D_
                x: rand(0, W),_x000D_
                y: rand(0, H)_x000D_
            },_x000D_
            c: {_x000D_
                x: rand(0, W),_x000D_
                y: rand(0, H)_x000D_
            }_x000D_
        };_x000D_
        if (checkClockwise(result.a, result.b, result.c)) return result;_x000D_
    }_x000D_
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>_x000D_
<pre>Click: place the point._x000D_
Double click: random triangle.</pre>_x000D_
_x000D_
<pre id="result"></pre>_x000D_
_x000D_
<canvas width="500" height="500"></canvas>
_x000D_
_x000D_
_x000D_

Here is equivalent C# code for Unity:

public static bool IsPointInClockwiseTriangle(Vector2 p, Vector2 p0, Vector2 p1, Vector2 p2)
{
    var s = (p0.y * p2.x - p0.x * p2.y + (p2.y - p0.y) * p.x + (p0.x - p2.x) * p.y);
    var t = (p0.x * p1.y - p0.y * p1.x + (p0.y - p1.y) * p.x + (p1.x - p0.x) * p.y);

    if (s <= 0 || t <= 0)
        return false;

    var A = (-p1.y * p2.x + p0.y * (-p1.x + p2.x) + p0.x * (p1.y - p2.y) + p1.x * p2.y);

    return (s + t) < A;
}

Python: How to ignore an exception and proceed?

Try this:

try:
    blah()
except:
    pass

Can I make a function available in every controller in angular?

AngularJs has "Services" and "Factories" just for problems like yours.These are used to have something global between Controllers, Directives, Other Services or any other angularjs components..You can defined functions, store data, make calculate functions or whatever you want inside Services and use them in AngularJs Components as Global.like

angular.module('MyModule', [...])
  .service('MyService', ['$http', function($http){
    return {
       users: [...],
       getUserFriends: function(userId){
          return $http({
            method: 'GET',
            url: '/api/user/friends/' + userId
          });
       }
       ....
    }
  }])

if you need more

Find More About Why We Need AngularJs Services and Factories

Logical XOR operator in C++?

Here is how I think you write an XOR comparison in C++:

bool a = true;   // Test by changing to true or false
bool b = false;  // Test by changing to true or false
if (a == !b)     // THIS IS YOUR XOR comparison
{
    // do whatever
}

Proof

XOR TABLE
 a   b  XOR
--- --- ---
 T   T   F
 T   F   T
 F   T   T
 F   F   F

a == !b TABLE
 a   b  !b  a == !b
--- --- --- -------
 T   T   F     F
 T   F   T     T
 F   T   F     T
 F   F   T     F

The proof is that an exhaustive study of inputs and outputs shows that in the two tables, for every input set the result is always the identical in the two tables.

Therefore, the original question being how to write:

return (A==5) ^^ (B==5)

The answer would be

return (A==5) == !(B==5);

Or if you like, write

return !(A==5) == (B==5);

How to pass multiple parameter to @Directives (@Components) in Angular with TypeScript?

From the Documentation

As with components, you can add as many directive property bindings as you need by stringing them along in the template.

Add an input property to HighlightDirective called defaultColor:

@Input() defaultColor: string;

Markup

<p [myHighlight]="color" defaultColor="violet">
  Highlight me too!
</p>

Angular knows that the defaultColor binding belongs to the HighlightDirective because you made it public with the @Input decorator.

Either way, the @Input decorator tells Angular that this property is public and available for binding by a parent component. Without @Input, Angular refuses to bind to the property.

For your example

With many parameters

Add properties into the Directive class with @Input() decorator

@Directive({
    selector: '[selectable]'
})
export class SelectableDirective{
    private el: HTMLElement;

    @Input('selectable') option:any;   
    @Input('first') f;
    @Input('second') s;

    ...
}

And in the template pass bound properties to your li element

<li *ngFor = 'let opt of currentQuestion.options' 
    [selectable] = 'opt' 
    [first]='YourParameterHere'
    [second]='YourParameterHere'
    (selectedOption) = 'onOptionSelection($event)'>
    {{opt.option}}
</li>

Here on the li element we have a directive with name selectable. In the selectable we have two @Input()'s, f with name first and s with name second. We have applied these two on the li properties with name [first] and [second]. And our directive will find these properties on that li element, which are set for him with @Input() decorator. So selectable, [first] and [second] will be bound to every directive on li, which has property with these names.

With single parameter

@Directive({
    selector: '[selectable]'
})
export class SelectableDirective{
    private el: HTMLElement;

    @Input('selectable') option:any;   
    @Input('params') params;

    ...
}

Markup

<li *ngFor = 'let opt of currentQuestion.options' 
    [selectable] = 'opt' 
    [params]='{firstParam: 1, seconParam: 2, thirdParam: 3}'
    (selectedOption) = 'onOptionSelection($event)'>
    {{opt.option}}
</li>

git pull displays "fatal: Couldn't find remote ref refs/heads/xxxx" and hangs up

I have same error. Problem was that branch was deleted, released. But in PhpStorm I still could see it in remote branches. I could checkout as local branch. And then doing git pull was giving this error.

So need to check if this brnach really exists remotely.

running php script (php function) in linux bash

I was in need to decode URL in a Bash script. So I decide to use PHP in this way:

$ cat url-decode.sh
#!/bin/bash
URL='url=https%3a%2f%2f1%2fecp%2f'
/usr/bin/php -r '$arg1 = $argv[1];echo rawurldecode($arg1);' "$URL"

Sample output:

$ ./url-decode.sh 
url=https://1/ecp/

Triangle Draw Method

There is no direct method to draw a triangle. You can use drawPolygon() method for this. It takes three parameters in the following form: drawPolygon(int x[],int y[], int number_of_points); To draw a triangle: (Specify the x coordinates in array x and y coordinates in array y and number of points which will be equal to the elements of both the arrays.Like in triangle you will have 3 x coordinates and 3 y coordinates which means you have 3 points in total.) Suppose you want to draw the triangle using the following points:(100,50),(70,100),(130,100) Do the following inside public void paint(Graphics g):

int x[]={100,70,130};
int y[]={50,100,100};
g.drawPolygon(x,y,3);

Similarly you can draw any shape using as many points as you want.

IE8 issue with Twitter Bootstrap 3

I had this same issue when transitioning from Bootstrap 2 to 3. I'd already got respond.js and html5shiv.js and set my meta to edge. I'd missed that from 2 to 3 the navbar element type had changed. In Bootstrap 2 it was nav. In Bootstrap 3 it's now header. So to fully resolve the problem I had to

<meta http-equiv="X-UA-Compatible" content="IE=edge">

Put this right after I'd loaded my css:

<!--[if lt IE 9]>  
    <script src="~/Content/compatibility/html5shiv.js"></script>
    <script src="~/Content/compatibility/respond.min.js"></script>
<![endif]-->

and then change

<nav class="navbar" role="navigation">
</nav>

to

<header class="navbar" role="navigation">
</header>

Oh and for good measure I also added

<meta name="viewport" content="width=device-width, initial-scale=1.0">

simply because that's what the Bootstrap site itself has.

How do I use a 32-bit ODBC driver on 64-bit Server 2008 when the installer doesn't create a standard DSN?

Open IIS manager, select Application Pools, select the application pool you are using, click on Advanced Settings in the right-hand menu. Under General, set "Enable 32-Bit Applications" to "True".

how to get request path with express req object

//auth required or redirect
app.use('/account', function(req, res, next) {
  console.log(req.path);
  if ( !req.session.user ) {
    res.redirect('/login?ref='+req.path);
  } else {
    next();
  }
});

req.path is / when it should be /account ??

The reason for this is that Express subtracts the path your handler function is mounted on, which is '/account' in this case.

Why do they do this?

Because it makes it easier to reuse the handler function. You can make a handler function that does different things for req.path === '/' and req.path === '/goodbye' for example:

function sendGreeting(req, res, next) {
  res.send(req.path == '/goodbye' ? 'Farewell!' : 'Hello there!')
}

Then you can mount it to multiple endpoints:

app.use('/world', sendGreeting)
app.use('/aliens', sendGreeting)

Giving:

/world           ==>  Hello there!
/world/goodbye   ==>  Farewell!
/aliens          ==>  Hello there!
/aliens/goodbye  ==>  Farewell!

What is the path for the startup folder in windows 2008 server

You can easily reach them by using the Run window and entering:

shell:startup

and

shell:common startup

Source.

How to disable GCC warnings for a few lines of code

I had same issue with external libraries like ROS headers. I like to use following options in CMakeLists.txt for stricter compilation:

set(CMAKE_CXX_FLAGS "-std=c++0x -Wall -Wextra -Wstrict-aliasing -pedantic -Werror -Wunreachable-code ${CMAKE_CXX_FLAGS}")

However doing this causes all kind of pedantic errors in externally included libraries as well. The solution is to disable all pedantic warnings before you include external libraries and re-enable like this:

//save compiler switches
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpedantic"

//Bad headers with problem goes here
#include <ros/ros.h>
#include <sensor_msgs/LaserScan.h>

//restore compiler switches
#pragma GCC diagnostic pop

git add only modified changes and ignore untracked files

Ideally your .gitignore should prevent the untracked ( and ignored )files from being shown in status, added using git add etc. So I would ask you to correct your .gitignore

You can do git add -u so that it will stage the modified and deleted files.

You can also do git commit -a to commit only the modified and deleted files.

Note that if you have Git of version before 2.0 and used git add ., then you would need to use git add -u . (See "Difference of “git add -A” and “git add .").

How to make popup look at the centre of the screen?

If the effect you want is to center in the center of the screen no matter where you've scrolled to, it's even simpler than that:

In your CSS use (for example)

div.centered{
  width: 100px;
  height: 50px;
  position:fixed; 
  top: calc(50% - 25px); // half of width
  left: calc(50% - 50px); // half of height
}

No JS required.

using nth-child in tables tr td

table tr td:nth-child(2) {
    background: #ccc;
}

Working example: http://jsfiddle.net/gqr3J/

Django: Display Choice Value

For every field that has choices set, the object will have a get_FOO_display() method, where FOO is the name of the field. This method returns the “human-readable” value of the field.

In Views

person = Person.objects.filter(to_be_listed=True)
context['gender'] = person.get_gender_display()

In Template

{{ person.get_gender_display }}

Documentation of get_FOO_display()

How to bind list to dataGridView?

Instead of create the new Container class you can use a dataTable.

DataTable dt = new DataTable();
dt.Columns.Add("My first column Name");

dt.Rows.Add(new object[] { "Item 1" });
dt.Rows.Add(new object[] { "Item number 2" });
dt.Rows.Add(new object[] { "Item number three" });

myDataGridView.DataSource = dt;

More about this problem you can find here: http://psworld.pl/Programming/BindingListOfString

Sort a two dimensional array based on one column

If you are looking for easy one liners to sort 2d array, then here you go.


Sort String[][] arr in ascending order by first column

Arrays.sort(arr, (a, b) -> a[0].compareTo(b[0]);

Sort String[][] arr in descending order by first column

Arrays.sort(arr, (a, b) -> b[0].compareTo(a[0]);

Sort String[][] arr in ascending order by second column

Arrays.sort(arr, (a, b) -> a[1].compareTo(b[1]);

Sort String[][] arr in descending order by second column

Arrays.sort(arr, (a, b) -> b[1].compareTo(a[1]);

Sort int[][] arr in ascending order by first column

Arrays.sort(arr, (a, b) -> Integer.compare(a[0], b[0]));

or

Arrays.sort(arr, (a, b) -> a[0] - b[0]);

Sort int[][] arr in descending order by first column

Arrays.sort(arr, (a, b) -> Integer.compare(b[0], a[0]));

or

Arrays.sort(arr, (a, b) -> b[0] - a[0]);

Sort int[][] arr in ascending order by second column

Arrays.sort(arr, (a, b) -> Integer.compare(a[1], b[1]));

or

Arrays.sort(arr, (a, b) -> a[1] - b[1]);

Sort int[][] arr in descending order by second column

Arrays.sort(arr, (a, b) -> Integer.compare(b[1], a[1]));

or

Arrays.sort(arr, (a, b) -> b[1] - a[1]);

Bootstrap 3 collapse accordion: collapse all works but then cannot expand all while maintaining data-parent

For whatever reason $('.panel-collapse').collapse({'toggle': true, 'parent': '#accordion'}); only seems to work the first time and it only works to expand the collapsible. (I tried to start with a expanded collapsible and it wouldn't collapse.)

It could just be something that runs once the first time you initialize collapse with those parameters.

You will have more luck using the show and hide methods.

Here is an example:

$(function() {

  var $active = true;

  $('.panel-title > a').click(function(e) {
    e.preventDefault();
  });

  $('.collapse-init').on('click', function() {
    if(!$active) {
      $active = true;
      $('.panel-title > a').attr('data-toggle', 'collapse');
      $('.panel-collapse').collapse('hide');
      $(this).html('Click to disable accordion behavior');
    } else {
      $active = false;
      $('.panel-collapse').collapse('show');
      $('.panel-title > a').attr('data-toggle','');
      $(this).html('Click to enable accordion behavior');
    }
  });

});

http://bootply.com/98201

Update

Granted KyleMit seems to have a way better handle on this then me. I'm impressed with his answer and understanding.

I don't understand what's going on or why the show seemed to be toggling in some places.

But After messing around for a while.. Finally came with the following solution:

$(function() {
  var transition = false;
  var $active = true;

  $('.panel-title > a').click(function(e) {
    e.preventDefault();
  });

  $('#accordion').on('show.bs.collapse',function(){
    if($active){
        $('#accordion .in').collapse('hide');
    }
  });

  $('#accordion').on('hidden.bs.collapse',function(){
    if(transition){
        transition = false;
        $('.panel-collapse').collapse('show');
    }
  });

  $('.collapse-init').on('click', function() {
    $('.collapse-init').prop('disabled','true');
    if(!$active) {
      $active = true;
      $('.panel-title > a').attr('data-toggle', 'collapse');
      $('.panel-collapse').collapse('hide');
      $(this).html('Click to disable accordion behavior');
    } else {
      $active = false;
      if($('.panel-collapse.in').length){
        transition = true;
        $('.panel-collapse.in').collapse('hide');       
      }
      else{
        $('.panel-collapse').collapse('show');
      }
      $('.panel-title > a').attr('data-toggle','');
      $(this).html('Click to enable accordion behavior');
    }
    setTimeout(function(){
        $('.collapse-init').prop('disabled','');
    },800);
  });
});

http://bootply.com/98239

Modular multiplicative inverse function in Python

Here is my code, it might be sloppy but it seems to work for me anyway.

# a is the number you want the inverse for
# b is the modulus

def mod_inverse(a, b):
    r = -1
    B = b
    A = a
    eq_set = []
    full_set = []
    mod_set = []

    #euclid's algorithm
    while r!=1 and r!=0:
        r = b%a
        q = b//a
        eq_set = [r, b, a, q*-1]
        b = a
        a = r
        full_set.append(eq_set)

    for i in range(0, 4):
        mod_set.append(full_set[-1][i])

    mod_set.insert(2, 1)
    counter = 0

    #extended euclid's algorithm
    for i in range(1, len(full_set)):
        if counter%2 == 0:
            mod_set[2] = full_set[-1*(i+1)][3]*mod_set[4]+mod_set[2]
            mod_set[3] = full_set[-1*(i+1)][1]

        elif counter%2 != 0:
            mod_set[4] = full_set[-1*(i+1)][3]*mod_set[2]+mod_set[4]
            mod_set[1] = full_set[-1*(i+1)][1]

        counter += 1

    if mod_set[3] == B:
        return mod_set[2]%B
    return mod_set[4]%B

Magento - How to add/remove links on my account navigation?

Also, you need to do something like this in config.xml if you are developing a customized module

    <frontend>
        <layout>
            <updates>
                <hpcustomer>
                    <file>hpcustomer.xml</file>
                </hpcustomer>
            </updates>
        </layout>
    </frontend>

How to check if a std::thread is still running?

Create a mutex that the running thread and the calling thread both have access to. When the running thread starts it locks the mutex, and when it ends it unlocks the mutex. To check if the thread is still running, the calling thread calls mutex.try_lock(). The return value of that is the status of the thread. (Just make sure to unlock the mutex if the try_lock worked)

One small problem with this, mutex.try_lock() will return false between the time the thread is created, and when it locks the mutex, but this can be avoided using a slightly more complex method.

jquery beforeunload when closing (not leaving) the page?

You can do this by using JQuery.

For example ,

<a href="your URL" id="navigate"> click here </a>

Your JQuery will be,

$(document).ready(function(){

    $('a').on('mousedown', stopNavigate);

    $('a').on('mouseleave', function () {
           $(window).on('beforeunload', function(){
                  return 'Are you sure you want to leave?';
           });
    });
});

function stopNavigate(){    
    $(window).off('beforeunload');
}

And to get the Leave message alert will be,

$(window).on('beforeunload', function(){
      return 'Are you sure you want to leave?';
});

$(window).on('unload', function(){

         logout();

});

This solution works in all browsers and I have tested it.

How to create a shortcut using PowerShell

Beginning PowerShell 5.0 New-Item, Remove-Item, and Get-ChildItem have been enhanced to support creating and managing symbolic links. The ItemType parameter for New-Item accepts a new value, SymbolicLink. Now you can create symbolic links in a single line by running the New-Item cmdlet.

New-Item -ItemType SymbolicLink -Path "C:\temp" -Name "calc.lnk" -Value "c:\windows\system32\calc.exe"

Be Carefull a SymbolicLink is different from a Shortcut, shortcuts are just a file. They have a size (A small one, that just references where they point) and they require an application to support that filetype in order to be used. A symbolic link is filesystem level, and everything sees it as the original file. An application needs no special support to use a symbolic link.

Anyway if you want to create a Run As Administrator shortcut using Powershell you can use

$file="c:\temp\calc.lnk"
$bytes = [System.IO.File]::ReadAllBytes($file)
$bytes[0x15] = $bytes[0x15] -bor 0x20 #set byte 21 (0x15) bit 6 (0x20) ON (Use –bor to set RunAsAdministrator option and –bxor to unset)
[System.IO.File]::WriteAllBytes($file, $bytes)

If anybody want to change something else in a .LNK file you can refer to official Microsoft documentation.

Setting dynamic scope variables in AngularJs - scope.<some_string>

If you were trying to do what I imagine you were trying to do, then you only have to treat scope like a regular JS object.

This is what I use for an API success response for JSON data array...

function(data){

    $scope.subjects = [];

    $.each(data, function(i,subject){
        //Store array of data types
        $scope.subjects.push(subject.name);

        //Split data in to arrays
        $scope[subject.name] = subject.data;
    });
}

Now {{subjects}} will return an array of data subject names, and in my example there would be a scope attribute for {{jobs}}, {{customers}}, {{staff}}, etc. from $scope.jobs, $scope.customers, $scope.staff

Google Script to see if text contains a value

I used the Google Apps Script method indexOf() and its results were wrong. So I wrote the small function Myindexof(), instead of indexOf:

function Myindexof(s,text)
{
  var lengths = s.length;
  var lengtht = text.length;
  for (var i = 0;i < lengths - lengtht + 1;i++)
  {
    if (s.substring(i,lengtht + i) == text)
      return i;
  }
  return -1;
}

var s = 'Hello!';
var text = 'llo';
if (Myindexof(s,text) > -1)
   Logger.log('yes');
else
   Logger.log('no');

Gradle - Move a folder from ABC to XYZ

Your task declaration is incorrectly combining the Copy task type and project.copy method, resulting in a task that has nothing to copy and thus never runs. Besides, Copy isn't the right choice for renaming a directory. There is no Gradle API for renaming, but a bit of Groovy code (leveraging Java's File API) will do. Assuming Project1 is the project directory:

task renABCToXYZ {     doLast {         file("ABC").renameTo(file("XYZ"))     } } 

Looking at the bigger picture, it's probably better to add the renaming logic (i.e. the doLast task action) to the task that produces ABC.

Ansible: filter a list by its attributes

I've submitted a pull request (available in Ansible 2.2+) that will make this kinds of situations easier by adding jmespath query support on Ansible. In your case it would work like:

- debug: msg="{{ addresses | json_query(\"private_man[?type=='fixed'].addr\") }}"

would return:

ok: [localhost] => {
    "msg": [
        "172.16.1.100"
    ]
}

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

In my case, I was inflating a PopupMenu at the very beginning of the activity i.e on onCreate()... I fixed it by putting it in a Handler

  new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                PopupMenu popuMenu=new PopupMenu(SplashScreen.this,binding.progressBar);
                popuMenu.inflate(R.menu.bottom_nav_menu);
                popuMenu.show();
            }
        },100);

rails bundle clean

If you are using Bundler 1.1 or later you can use bundle clean, just as you imagined you could. This is redundant if you're using bundle install --path (Bundler manages the location you specified with --path, so takes responsibility for removing outdated gems), but if you've used Bundler to install the gems as system gems then bundle clean --force will delete any system gems not required by your Gemfile. Blindingly obvious caveat: don't do this if you have other apps that rely on system gems that aren't in your Gemfile!

Pat Shaughnessy has a good description of bundle clean and other new additions in bundler 1.1.

How to configure welcome file list in web.xml

You need to put the JSP file in /index.jsp instead of in /WEB-INF/jsp/index.jsp. This way the whole servlet is superflous by the way.

WebContent
 |-- META-INF
 |-- WEB-INF
 |    `-- web.xml
 `-- index.jsp

If you're absolutely positive that you need to invoke a servlet this strange way, then you should map it on an URL pattern of /index.jsp instead of /index. You only need to change it to get the request dispatcher from request instead of from config and get rid of the whole init() method.

In case you actually intend to have a "home page servlet" (and thus not a welcome file — which has an entirely different purpose; namely the default file which sould be served when a folder is being requested, which is thus not specifically the root folder), then you should be mapping the servlet on the empty string URL pattern.

<servlet-mapping>
    <servlet-name>index</servlet-name>
    <url-pattern></url-pattern>
</servlet-mapping>

See also Difference between / and /* in servlet mapping url pattern.

compare two list and return not matching items using linq

The naive approach:

MsgList.Where(x => !SentList.Any(y => y.MsgID == x.MsgID))

Be aware this will take up to m*n operations as it compares every MsgID in SentList to each in MsgList ("up to" because it will short-circuit when it does happen to match).

Strip out HTML and Special Characters

Here's a function I've been using that I've put together from various threads around the net that removes everything, all tags and leaves you with a perfect phrase. Does anyone know how to modify this script to allow periods (.) ? In other words, leave everything 'as is' but leave the periods alone or other punctuation like and ! or a comma? let me know.

function stripAlpha( $item )

{

    $search     = array( 
         '@<script[^>]*?>.*?</script>@si'   // Strip out javascript 
        ,'@<style[^>]*?>.*?</style>@siU'    // Strip style tags properly 
        ,'@<[\/\!]*?[^<>]*?>@si'            // Strip out HTML tags
        ,'@<![\s\S]*?–[ \t\n\r]*>@'         // Strip multi-line comments including CDATA
        ,'/\s{2,}/'
        ,'/(\s){2,}/'

    );

    $pattern    = array(

         '#[^a-zA-Z ]#'                     // Non alpha characters
        ,'/\s+/'                            // More than one whitespace

    );

    $replace    = array(
         ''
        ,' '

    );

    $item = preg_replace( $search, '', html_entity_decode( $item ) );
    $item = trim( preg_replace( $pattern, $replace, strip_tags( $item ) ) );
    return $item;

}

React Error: Target Container is not a DOM Element

webpack solution

If you got this error while working in React with webpack and HMR.

You need to create template index.html and save it in src folder:

<html>
    <body>
       <div id="root"></root>
    </body>
</html>

Now when we have template with id="root" we need to tell webpack to generate index.html which will mirror our index.html file.

To do that:

plugins: [
    new HtmlWebpackPlugin({
        title: "Application name",
        template: './src/index.html'
    })
],

template property will tell webpack how to build index.html file.

Remove characters except digits from string using Python?

along the lines of bayer's answer:

''.join(i for i in s if i.isdigit())

Youtube API Limitations

A little bit late, but you can request a higher quote here: https://support.google.com/youtube/contact/yt_api_form

No module named serial

You do not have serial package installed.

Try pip install serial to install the module.

Alternatively, install it in binary form from here:

Install Pyserial for Windows

Note that you always install precompiled binaries at your own risk.

How do I add a ToolTip to a control?

ToolTip in C# is very easy to add to almost all UI controls. You don't need to add any MouseHover event for this.

This is how to do it-

  1. Add a ToolTip object to your form. One object is enough for the entire form. ToolTip toolTip = new ToolTip();

  2. Add the control to the tooltip with the desired text.

    toolTip.SetToolTip(Button1,"Click here");

Parse an URL in JavaScript

This should fix a few edge-cases in kobe's answer:

function getQueryParam(url, key) {
  var queryStartPos = url.indexOf('?');
  if (queryStartPos === -1) {
    return;
  }
  var params = url.substring(queryStartPos + 1).split('&');
  for (var i = 0; i < params.length; i++) {
    var pairs = params[i].split('=');
    if (decodeURIComponent(pairs.shift()) == key) {
      return decodeURIComponent(pairs.join('='));
    }
  }
}

getQueryParam('http://example.com/form_image_edit.php?img_id=33', 'img_id');
// outputs "33"

change background image in body

If you have JQuery loaded already, you can just do this:

$('body').css('background-image', 'url(../images/backgrounds/header-top.jpg)');

EDIT:

First load JQuery in the head tag:

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js" type="text/javascript"></script>

Then call the Javascript to change the background image when something happens on the page, like when it finishes loading:

<script type="text/javascript">
    $(document).ready(function() {
        $('body').css('background-image', 'url(../images/backgrounds/header-top.jpg)');
    });
</script>

ALTER TABLE on dependent column

you can drop the Constraint which is restricting you. If the column has access to other table. suppose a view is accessing the column which you are altering then it wont let you alter the column unless you drop the view. and after making changes you can recreate the view.

enter image description here

How to convert milliseconds into a readable date?

Building on lonesomeday's example (upvote that answer not this one), I ran into this output:

undefined NaN, NaN

_x000D_
_x000D_
var datetime = '1324339200000'; //LOOK HERE_x000D_
_x000D_
function prettyDate(date) {_x000D_
  var months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',_x000D_
                'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];_x000D_
_x000D_
  return months[date.getUTCMonth()] + ' ' + date.getUTCDate() + ', ' + date.getUTCFullYear();_x000D_
}_x000D_
_x000D_
console.log(prettyDate(new Date(datetime))); //AND HERE
_x000D_
_x000D_
_x000D_

The cause was using a string as input. To fix it, prefix the string with a plus sign:

prettyDate(new Date(+datetime));

_x000D_
_x000D_
var datetime = '1324339200000';_x000D_
_x000D_
function prettyDate(date) {_x000D_
  var months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',_x000D_
                'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];_x000D_
_x000D_
  return months[date.getUTCMonth()] + ' ' + date.getUTCDate() + ', ' + date.getUTCFullYear();_x000D_
}_x000D_
_x000D_
console.log(prettyDate(new Date(+datetime))); //HERE
_x000D_
_x000D_
_x000D_

To add Hours/Minutes to the output:

_x000D_
_x000D_
var datetime = '1485010730253';_x000D_
_x000D_
function prettyDate(date) {_x000D_
  var months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',_x000D_
                'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];_x000D_
_x000D_
  return months[date.getUTCMonth()] +' '+ date.getUTCDate()+ ', '+ date.getUTCHours() +':'+ date.getUTCMinutes();_x000D_
}_x000D_
_x000D_
console.log(prettyDate(new Date(+datetime)));
_x000D_
_x000D_
_x000D_

How to correct TypeError: Unicode-objects must be encoded before hashing?

You must have to define encoding format like utf-8, Try this easy way,

This example generates a random number using the SHA256 algorithm:

>>> import hashlib
>>> hashlib.sha256(str(random.getrandbits(256)).encode('utf-8')).hexdigest()
'cd183a211ed2434eac4f31b317c573c50e6c24e3a28b82ddcb0bf8bedf387a9f'

Web scraping with Java

You might look into jwht-scrapper!

This is a complete scrapping framework that has all the features a developper could expect from a web scrapper:

It works with (jwht-htmltopojo)[https://github.com/whimtrip/jwht-htmltopojo) lib which itsef uses Jsoup mentionned by several other people here.

Together they will help you built awesome scrappers mapping directly HTML to POJOs and bypassing any classical scrapping problems in only a matter of minutes!

Hope this might help some people here!

Disclaimer, I am the one who developed it, feel free to let me know your remarks!

Why does the 'int' object is not callable error occur when using the sum() function?

You probably redefined your "sum" function to be an integer data type. So it is rightly telling you that an integer is not something you can pass a range.

To fix this, restart your interpreter.

Python 2.7.3 (default, Apr 20 2012, 22:44:07) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> data1 = range(0, 1000, 3)
>>> data2 = range(0, 1000, 5)
>>> data3 = list(set(data1 + data2)) # makes new list without duplicates
>>> total = sum(data3) # calculate sum of data3 list's elements
>>> print total
233168

If you shadow the sum builtin, you can get the error you are seeing

>>> sum = 0
>>> total = sum(data3) # calculate sum of data3 list's elements
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'int' object is not callable

Also, note that sum will work fine on the set there is no need to convert it to a list

Real escape string and PDO

PDO offers an alternative designed to replace mysql_escape_string() with the PDO::quote() method.

Here is an excerpt from the PHP website:

<?php
    $conn = new PDO('sqlite:/home/lynn/music.sql3');

    /* Simple string */
    $string = 'Nice';
    print "Unquoted string: $string\n";
    print "Quoted string: " . $conn->quote($string) . "\n";
?>

The above code will output:

Unquoted string: Nice
Quoted string: 'Nice'

How to get the real path of Java application at runtime?

And what about using this.getClass().getProtectionDomain().getCodeSource().getLocation()?

View JSON file in Browser

For Firefox's Bookmarks JSON files, use this excellent Bookmarklet:

javascript:(function(){var E=document.getElementsByTagName('PRE')[0],T=E.innerHTML,i=0,r1,r2;t=new Array();while(/("uri":"([^"]*)")/g.exec(T)){r1=RegExp.$1;r2=RegExp.$2;if(/^https?:/.exec(r2)){t[i++]='['+(i)+']:<a href='+r2+'>'+r2+'<\/a>';}}with(window.open().document){for(i=0;t[i];i++)write(t[i]+'<br>');close();}})();

Source: "alterna" from forums.Mozillazine.org: http://forums.mozillazine.org/viewtopic.php?p=5551705#p5551705

How to select only date from a DATETIME field in MySQL?

You can use select DATE(time) from appointment_details for date only

or

You can use select TIME(time) from appointment_details for time only

What are file descriptors, explained in simple terms?

Addition to above all simplified responses.

If you are working with files in bash script, it's better to use file descriptor.

For example: If you want to read and write from/to the file "test.txt", use the file descriptor as show below:

FILE=$1 # give the name of file in the command line
exec 5<>$FILE # '5' here act as the file descriptor

# Reading from the file line by line using file descriptor
while read LINE; do
    echo "$LINE"
done <&5

# Writing to the file using descriptor
echo "Adding the date: `date`" >&5 
exec 5<&- # Closing a file descriptor

Where can I find a list of keyboard keycodes?

I know this was asked awhile back, but I found a comprehensive list of the virtual keyboard key codes right in MSDN, for use in C/C++. This also includes the mouse events. Note it is different than the javascript key codes (I noticed it around the VK_OEM section).

Here's the link:
http://msdn.microsoft.com/en-us/library/windows/desktop/dd375731(v=vs.85).aspx

Load dimension value from res/values/dimension.xml from source code

For those who just need to save some int value in the resources, you can do the following.

integers.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <integer name="default_value">100</integer>
</resources> 

Code

int defaultValue = getResources().getInteger(R.integer.default_value);

How to read the value of a private field from a different class in Java?

Reflection isn't the only way to resolve your issue (which is to access the private functionality/behaviour of a class/component)

An alternative solution is to extract the class from the .jar, decompile it using (say) Jode or Jad, change the field (or add an accessor), and recompile it against the original .jar. Then put the new .class ahead of the .jar in the classpath, or reinsert it in the .jar. (the jar utility allows you to extract and reinsert to an existing .jar)

As noted below, this resolves the wider issue of accessing/changing private state rather than simply accessing/changing a field.

This requires the .jar not to be signed, of course.

How to get the current loop index when using Iterator?

What kind of collection? If it's an implementation of the List interface then you could just use it.nextIndex() - 1.

The specified type member is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported

In this case, one of the easiest and best approach is to first cast it to list and then use where or select.

result = result.ToList().where(p => date >= p.DOB);

Immutable vs Mutable types

Difference between Mutable and Immutable objects

Definitions

Mutable object: Object that can be changed after creating it.
Immutable object: Object that cannot be changed after creating it.

In python if you change the value of the immutable object it will create a new object.

Mutable Objects

Here are the objects in Python that are of mutable type:

  1. list
  2. Dictionary
  3. Set
  4. bytearray
  5. user defined classes

Immutable Objects

Here are the objects in Python that are of immutable type:

  1. int
  2. float
  3. decimal
  4. complex
  5. bool
  6. string
  7. tuple
  8. range
  9. frozenset
  10. bytes

Some Unanswered Questions

Questions: Is string an immutable type?
Answer: yes it is, but can you explain this: Proof 1:

a = "Hello"
a +=" World"
print a

Output

"Hello World"

In the above example the string got once created as "Hello" then changed to "Hello World". This implies that the string is of the mutable type. But it is not when we check its identity to see whether it is of a mutable type or not.

a = "Hello"
identity_a = id(a)
a += " World"
new_identity_a = id(a)
if identity_a != new_identity_a:
    print "String is Immutable"

Output

String is Immutable

Proof 2:

a = "Hello World"
a[0] = "M"

Output

TypeError 'str' object does not support item assignment

Questions: Is Tuple an immutable type?
Answer: yes, it is. Proof 1:

tuple_a = (1,)
tuple_a[0] = (2,)
print a

Output

'tuple' object does not support item assignment

Get exit code of a background process

A simple example, similar to the solutions above. This doesn't require monitoring any process output. The next example uses tail to follow output.

$ echo '#!/bin/bash' > tmp.sh
$ echo 'sleep 30; exit 5' >> tmp.sh
$ chmod +x tmp.sh
$ ./tmp.sh &
[1] 7454
$ pid=$!
$ wait $pid
[1]+  Exit 5                  ./tmp.sh
$ echo $?
5

Use tail to follow process output and quit when the process is complete.

$ echo '#!/bin/bash' > tmp.sh
$ echo 'i=0; while let "$i < 10"; do sleep 5; echo "$i"; let i=$i+1; done; exit 5;' >> tmp.sh
$ chmod +x tmp.sh
$ ./tmp.sh
0
1
2
^C
$ ./tmp.sh > /tmp/tmp.log 2>&1 &
[1] 7673
$ pid=$!
$ tail -f --pid $pid /tmp/tmp.log
0
1
2
3
4
5
6
7
8
9
[1]+  Exit 5                  ./tmp.sh > /tmp/tmp.log 2>&1
$ wait $pid
$ echo $?
5

Join a list of items with different types as string in Python

How come no-one seems to like repr?
python 3.7.2:

>>> int_list = [1, 2, 3, 4, 5]
>>> print(repr(int_list))
[1, 2, 3, 4, 5]
>>> 

Take care though, it's an explicit representation. An example shows:

#Print repr(object) backwards
>>> print(repr(int_list)[::-1])
]5 ,4 ,3 ,2 ,1[
>>> 

more info at pydocs-repr

What are the differences between Mustache.js and Handlebars.js?

One subtle but significant difference is in the way the two libraries approach scope. Mustache will fall back to parent scope if it can't find a variable within the current context; Handlebars will return a blank string.

This is barely mentioned in the GitHub README, where there's one line for it:

Handlebars deviates from Mustache slightly in that it does not perform recursive lookup by default.

However, as noted there, there is a flag to make Handlebars behave in the same way as Mustache -- but it affects performance.

This has an effect on the way you can use # variables as conditionals.

For example in Mustache you can do this:

{{#variable}}<span class="text">{{variable}}</span>{{/variable}}

It basically means "if variable exists and is truthy, print a span with the variable in it". But in Handlebars, you would either have to:

  • use {{this}} instead
  • use a parent path, i.e., {{../variable}} to get back out to relevant scope
  • define a child variable value within the parent variable object

More details on this, if you want them, here.

How to convert all elements in an array to integer in JavaScript?

var inp=readLine();//reading the input as one line string
var nums=inp.split(" ").map(Number);//making an array of numbers
console.log(nums);`

input : 1 9 0 65 5 7 output:[ 1, 9, 0, 65, 5, 7 ]

what if we dont use .map(Number)

code

var inp=readLine();//reading the input as one line string
var nums=inp.split(" ");//making an array of strings
console.log(nums);

input : 1 9 0 65 5 7 output:[ '1', '9', '0', '65', '5', '7']

Convert float to std::string in C++

This tutorial gives a simple, yet elegant, solution, which i transcribe:

#include <sstream>
#include <string>
#include <stdexcept>

class BadConversion : public std::runtime_error {
public:
  BadConversion(std::string const& s)
    : std::runtime_error(s)
    { }
};

inline std::string stringify(double x)
{
  std::ostringstream o;
  if (!(o << x))
    throw BadConversion("stringify(double)");
  return o.str();
}
...
std::string my_val = stringify(val);

How to stop/cancel 'git log' command in terminal?

You can hit the key q (for quit) and it should take you to the prompt.

Please see this link.

How to extract extension from filename string in Javascript?

get the value in the variable & then separate its extension just like this.

var find_file_ext=document.getElementById('filename').value;
var file_ext=/[^.]+$/.exec(find_file_ext); 

This will help you.

How to find reason of failed Build without any error or warning

Seems that there are multiple answers to this question, so I'll add mine from personal experience hoping it will save someone time/stress.

Make sure all the projects in your solution are targeting the same .NET version.

Similar to OP, there were 0 errors but the build kept failing. However, there was one warning entry (buried in between several hundred useless XML warnings...) saying that one project was targeting a different .NET version than a project that was referencing it. The entire issue was that one project within my solution was targeting .NET 4.5.2, when the rest were targeting 4.5.1. It should work even with this discrepancy (hence why it was just a warning) but unfortunately, it broke the build.

The strange part was that it built/ran fine for a while, but suddenly the build started failing one time causing this issue. Not sure what I did for it to start complaining about differing .NET target versions, but I feel that there are just some mysteries in Visual Studio that will never be solved.

Maven: add a dependency to a jar by relative path

You can use eclipse to generate a runnable Jar : Export/Runable Jar file

HashSet vs LinkedHashSet

HashSet: Unordered actually. if u passing the parameter means

Set<Integer> set=new HashSet<Integer>();
for(int i=0;i<set.length;i++)
{
  SOP(set)`enter code here`
}

Out Put: May be 2,1,3 not predictable. next time another order.

LinkedHashSet() which produce FIFO Order.

On Selenium WebDriver how to get Text from Span Tag

PHP way of getting text from span tag:

$spanText = $this->webDriver->findElement(WebDriverBy::xpath("//*[@id='specInformation']/tbody/tr[2]/td[1]/span[1]"))->getText();

How to use sys.exit() in Python

In tandem with what Pedro Fontez said a few replies up, you seemed to never call the sys module initially, nor did you manage to stick the required () at the end of sys.exit:

so:

import sys

and when finished:

sys.exit()

Select multiple columns by labels in pandas

How do I select multiple columns by labels in pandas?

Multiple label-based range slicing is not easily supported with pandas, but position-based slicing is, so let's try that instead:

loc = df.columns.get_loc
df.iloc[:, np.r_[loc('A'):loc('C')+1, loc('E'), loc('G'):loc('I')+1]]

          A         B         C         E         G         H         I
0 -1.666330  0.321260 -1.768185 -0.034774  0.023294  0.533451 -0.241990
1  0.911498  3.408758  0.419618 -0.462590  0.739092  1.103940  0.116119
2  1.243001 -0.867370  1.058194  0.314196  0.887469  0.471137 -1.361059
3 -0.525165  0.676371  0.325831 -1.152202  0.606079  1.002880  2.032663
4  0.706609 -0.424726  0.308808  1.994626  0.626522 -0.033057  1.725315
5  0.879802 -1.961398  0.131694 -0.931951 -0.242822 -1.056038  0.550346
6  0.199072  0.969283  0.347008 -2.611489  0.282920 -0.334618  0.243583
7  1.234059  1.000687  0.863572  0.412544  0.569687 -0.684413 -0.357968
8 -0.299185  0.566009 -0.859453 -0.564557 -0.562524  0.233489 -0.039145
9  0.937637 -2.171174 -1.940916 -1.553634  0.619965 -0.664284 -0.151388

Note that the +1 is added because when using iloc the rightmost index is exclusive.


Comments on Other Solutions

  • filter is a nice and simple method for OP's headers, but this might not generalise well to arbitrary column names.

  • The "location-based" solution with loc is a little closer to the ideal, but you cannot avoid creating intermediate DataFrames (that are eventually thrown out and garbage collected) to compute the final result range -- something that we would ideally like to avoid.

  • Lastly, "pick your columns directly" is good advice as long as you have a manageably small number of columns to pick. It will, however not be applicable in some cases where ranges span dozens (or possibly hundreds) of columns.

Jaxb, Class has two properties of the same name

I did trial and error and got the conclusion that, you only have to use either of both @XMLElement or @XmlAccessorType(XmlAccessType.FIELD).

When to use which?

case 1 : If your field names and element name you want to use in xml file are different then you have to use @XMLElement(name="elementName"). As this will bind fields with that element name and display in XML file.

case 2 : If fields names and respective element name in xml both are same then you can simply use @XmlAccessorType(XmlAccessType.FIELD)

Is there an online application that automatically draws tree structures for phrases/sentences?

In short, yes. I assume you're looking to parse English: for that you can use the Link Parser from Carnegie Mellon.

It is important to remember that there are many theories of syntax, that can give completely different-looking phrase structure trees; further, the trees are different for each language, and tools may not exist for those languages.

As a note for the future: if you need a sentence parsed out and tag it as linguistics (and syntax or whatnot, if that's available), someone can probably parse it out for you and guide you through it.

Is it possible to start a shell session in a running container (without ssh)

Since things are achanging, at the moment the recommended way of accessing a running container is using nsenter.

You can find more information on this github repository. But in general you can use nsenter like this:

PID=$(docker inspect --format {{.State.Pid}} <container_name_or_ID>)
nsenter --target $PID --mount --uts --ipc --net --pid

or you can use the wrapper docker-enter:

docker-enter <container_name_or_ID>

A nice explanation on the topic can be found on Jérôme Petazzoni's blog entry: Why you don't need to run sshd in your docker containers

Call function with setInterval in jQuery?

To write the best code, you "should" use the latter approach, with a function reference:

var refreshId = setInterval(function() {}, 5000);

or

function test() {}
var refreshId = setInterval(test, 5000);

but your approach of

function test() {}
var refreshId = setInterval("test()", 5000);

is basically valid, too (as long as test() is global).

Note that there is no such thing really as "in jQuery". You're still writing the Javascript language; you're just using some pre-made functions that are the jQuery library.

htaccess Access-Control-Allow-Origin

In Zend Framework 2.0 i had this problem. Can be solved in two way .htaccess or php header i prefer .htaccess so i modified .htaccess from:

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^.*$ - [NC,L]
RewriteRule ^.*$ index.php [NC,L]

to

RewriteEngine On

<IfModule mod_headers.c>
    Header set Access-Control-Allow-Origin "*"
</IfModule>

RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^.*$ - [NC,L]
RewriteRule ^.*$ index.php [NC,L]

and it start to work

List all of the possible goals in Maven 2?

A Build Lifecycle is Made Up of Phases

Each of these build lifecycles is defined by a different list of build phases, wherein a build phase represents a stage in the lifecycle.

For example, the default lifecycle comprises of the following phases (for a complete list of the lifecycle phases, refer to the Lifecycle Reference):

  • validate - validate the project is correct and all necessary information is available
  • compile - compile the source code of the project
  • test - test the compiled source code using a suitable unit testing framework. These tests should not require the code be packaged or deployed
  • package - take the compiled code and package it in its distributable format, such as a JAR. verify - run any checks on results of integration tests to ensure quality criteria are met
  • install - install the package into the local repository, for use as a dependency in other projects locally
  • deploy - done in the build environment, copies the final package to the remote repository for sharing with other developers and projects.

These lifecycle phases (plus the other lifecycle phases not shown here) are executed sequentially to complete the default lifecycle. Given the lifecycle phases above, this means that when the default lifecycle is used, Maven will first validate the project, then will try to compile the sources, run those against the tests, package the binaries (e.g. jar), run integration tests against that package, verify the integration tests, install the verified package to the local repository, then deploy the installed package to a remote repository.

Source: https://maven.apache.org/guides/introduction/introduction-to-the-lifecycle.html

Can I convert long to int?

It can convert by

Convert.ToInt32 method

But it will throw an OverflowException if it the value is outside range of the Int32 Type. A basic test will show us how it works:

long[] numbers = { Int64.MinValue, -1, 0, 121, 340, Int64.MaxValue };
int result;
foreach (long number in numbers)
{
   try {
         result = Convert.ToInt32(number);
        Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                    number.GetType().Name, number,
                    result.GetType().Name, result);
     }
     catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.",
                    number.GetType().Name, number);
     }
}
// The example displays the following output:
//    The Int64 value -9223372036854775808 is outside the range of the Int32 type.
//    Converted the Int64 value -1 to the Int32 value -1.
//    Converted the Int64 value 0 to the Int32 value 0.
//    Converted the Int64 value 121 to the Int32 value 121.
//    Converted the Int64 value 340 to the Int32 value 340.
//    The Int64 value 9223372036854775807 is outside the range of the Int32 type.

Here there is a longer explanation.

How to exclude records with certain values in sql select

SELECT SC.StoreId 
FROM StoreClients SC
WHERE SC.StoreId NOT IN (SELECT StoreId FROM StoreClients WHERE ClientId = 5)

In this way neither JOIN nor GROUP BY is necessary.

Difference between window.location.href and top.location.href

The first one adds an item to your history in that you can (or should be able to) click "Back" and go back to the current page.

The second replaces the current history item so you can't go back to it.

See window.location:

  • assign(url): Load the document at the provided URL.

  • replace(url): Replace the current document with the one at the provided URL. The difference from the assign() method is that after using replace() the current page will not be saved in session history, meaning the user won't be able to use the Back button to navigate to it.

window.location.href = url;

is favoured over:

window.location = url;

WARNING: Setting property 'source' to 'org.eclipse.jst.jee.server:appname' did not find a matching property

You can change the eclipse tomcat server configuration. Open the server view, double click on you server to open server configuration. Then click to activate "Publish module contents to separate XML files". Finally, restart your server, the message must disappear.

Source: http://www.albeesonline.com/blog/2008/11/29/warning-setpropertiesruleserverserviceenginehostcontext-setting-property/