Programs & Examples On #Resource dll

.htaccess redirect all pages to new domain

If the new domain you are redirecting your old site to is on a diffrent host, you can simply use a Redirect

Redirect 301 /

This will redirect all requests from olddomain to the newdomain .

Redirect directive will not work or may cause a Redirect loop if your newdomain and olddomain both are on same host, in that case you'll need to use mod-rewrite to redirect based on the requested host header.

RewriteEngine on

RewriteCond %{HTTP_HOST} ^(www\.)?olddomain\.com$
RewriteRule ^{REQUEST_URI} [NE,L,R] 

What is the fastest way to send 100,000 HTTP requests in Python?

Using a thread pool is a good option, and will make this fairly easy. Unfortunately, python doesn't have a standard library that makes thread pools ultra easy. But here is a decent library that should get you started:

Code example from their site:

pool = ThreadPool(poolsize)
requests = makeRequests(some_callable, list_of_args, callback)
[pool.putRequest(req) for req in requests]

Hope this helps.

Finding non-numeric rows in dataframe in pandas?

In case you are working with a column with string values, you can use THE VERY USEFUL function series.str.isnumeric() like:

a = pd.Series(['hi','hola','2.31','288','312','1312', '0,21', '0.23'])

What i do is to copy that column to new column, and do a str.replace('.','') and str.replace(',','') then i select the numeric values. and:

a = a.str.replace('.','')
a = a.str.replace(',','') 

Out[15]: 0 False 1 False 2 True 3 True 4 True 5 True 6 True 7 True dtype: bool

Good luck all!

How to forcefully set IE's Compatibility Mode off from the server-side?

Update: More useful information What does <meta http-equiv="X-UA-Compatible" content="IE=edge"> do?

Maybe this url can help you: Activating Browser Modes with Doctype

Edit: Today we were able to override the compatibility view with: <meta http-equiv="X-UA-Compatible" content="IE=EmulateIE8" />

Image size (Python, OpenCV)

For me the easiest way is to take all the values returned by image.shape:

height, width, channels = img.shape

if you don't want the number of channels (useful to determine if the image is bgr or grayscale) just drop the value:

height, width, _ = img.shape

Count number of occurrences by month

Sooooo, I had this same question. here's my answer: COUNTIFS(sheet1!$A:$A,">="&D1,sheet1!$A:$A,"<="&D2)

you don't need to specify A2:A50, unless there are dates beyond row 50 that you wish to exclude. this is cleaner in the sense that you don't have to go back and adjust the rows as more PO data comes in on sheet1.

also, the reference to D1 and D2 are start and end dates (respectively) for each month. On sheet2, you could have a hidden column that translates April to 4/1/2014, May into 5/1/2014, etc. THen, D1 would reference the cell that contains 4/1/2014, and D2 would reference the cell that contains 5/1/2014.

if you want to sum, it works the same way, except that the first argument is the sum array (column or row) and then the rest of the ranges/arrays and arguments are the same as the countifs formula.

btw-this works in excel AND google sheets. cheers

Materialize CSS - Select Doesn't Seem to Render

Call the materialize css jquery code only after the html has rendered. So you can have a controller and then fire a service which calls the jquery code in the controller. This will render the select button alright. How ever if you try to use ngChange or ngSubmit it may not work due to the dynamic styling of the select tag.

PHP "pretty print" json_encode

Here's a function to pretty up your json: pretty_json

Flatten List in LINQ

iList.SelectMany(x => x).ToArray()

How to check if a process is in hang state (Linux)

you could check the files

/proc/[pid]/task/[thread ids]/status

Create an application setup in visual studio 2013

Apart from Install Shield and WiX, there is Inno Setup. Although I haven't tried it myself I have heard good things about it.

How can I read comma separated values from a text file in Java?

Use OpenCSV for reliability. Split should never be used for these kind of things. Here's a snippet from a program of my own, it's pretty straightforward. I check if a delimiter character was specified and use this one if it is, if not I use the default in OpenCSV (a comma). Then i read the header and fields

CSVReader reader = null;
try {
    if (delimiter > 0) {
        reader = new CSVReader(new FileReader(this.csvFile), this.delimiter);
    else {
        reader = new CSVReader(new FileReader(this.csvFile));

    // these should be the header fields
    header = reader.readNext();
    while ((fields = reader.readNext()) != null) {
        // more code
catch (IOException e) {

Android custom dropdown/popup menu

I know this is an old question, but I've found another answer that worked better for me and it doesn't seem to appear in any of the answers.

Create a layout xml:

<LinearLayout xmlns:android=""

    android:scaleType="fitXY" />



Create a ListPopupWindow and a map with the content:

ListPopupWindow popupWindow;
List<HashMap<String, Object>> data = new ArrayList<>();
HashMap<String, Object> map = new HashMap<>();
    map.put(TITLE, getString(R.string.left));
    map.put(ICON, R.drawable.left);
    map = new HashMap<>();
    map.put(TITLE, getString(R.string.right));
    map.put(ICON, R.drawable.right);

Then on click, display the menu using this function:

private void showListMenu(final View anchor) {
    popupWindow = new ListPopupWindow(this);

    ListAdapter adapter = new SimpleAdapter(
            new String[] {TITLE, ICON}, // These are just the keys that the data uses (constant strings)
            new int[] {,}); // The view ids to map the data to

    popupWindow.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            switch (position){
                case 0:
                case 1:
            runOnUiThread(new Runnable() {
                public void run() {

What to return if Spring MVC controller method doesn't return value?

You can simply return a ResponseEntity with the appropriate header:

@RequestMapping(value = "/updateSomeData" method = RequestMethod.POST)
public ResponseEntity updateDataThatDoesntRequireClientToBeNotified(...){
return new ResponseEntity(HttpStatus.OK)

How to work on UAC when installing XAMPP

This is a specific issue for Windows Vista, 7, 8 (and presumably newer).

User Account Control (UAC) is a feature in Windows that can help you stay in control of your computer by informing you when a program makes a change that requires administrator-level permission. UAC works by adjusting the permission level of your user account.

This is applied mostly to C:\Program Files. You may have noticed sometimes, that some applications can see files in C:\Program Files that does not exist there. You know why? Windows now tend to have "C:\Program Files" folder customized for every user. For example, old applications store config files (like .ini) in the same folder where the executable files are stored. In the good old days all users had the same configurations for such apps. In nowadays Windows stores configs in the special folder tied to the user account. Thus, now different users may have different configs while application still think that config files are in the same folder with the executables.

XAMPP does not like to have different config for different users. In fact it is not a config file for XAMPP, it is folders where you keep your projects and databases. The idea of XAMPP is to make projects same for all users. This is a source of a conflict with Windows.

All you need is to avoid installing XAMPP into C:\Program Files. Thus XAMPP will always use the original files for all users and there would be no confusion.

I recommend to install XAMPP into the special folder in root directory like in C:\XAMPP. But before you choose the folder you need to click on this warning message.

align images side by side in html

Try using this format

   <img src="img" alt="The Pulpit Rock" width="304" height="228">
   <figcaption>Fig1. - A view of the pulpit rock in Norway.</figcaption>

This will give you a real caption (just add the 2nd and 3rd imgs using Float:left like others suggested)

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

Use subscripting to access the value for a dictionary key. This will return an Optional:

let apple: String? = companies["AAPL"]


if let apple = companies["AAPL"] {
    // ...

You can also enumerate over all of the keys and values:

var companies = ["AAPL" : "Apple Inc", "GOOG" : "Google Inc", "AMZN" : ", Inc", "FB" : "Facebook Inc"]

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

Or enumerate over all of the values:

for value in Array(companies.values) {

Call to undefined function mysql_connect

One time I had a problem while using Off instead of off. And also check the pads one more time... The path has to be exact. Also add the following line to your environmental variable.

C:\your-apache-path\bin; C:\your-php-path\bin;C:\your-mysql-path\bin

If you are in Windows, right click My Computer, select properties, and navigate to the Advanced tab... (is Windows 7). Click on Advanced system settings first then select the Advanced tab and then Environmental variables. Select PATH and click on Edit. Make a copy of the string in a .txt file for back up (it might be empty)--- set your environmental variables... Log out and log back in.

Equivalent of SQL ISNULL in LINQ?

You can use the ?? operator to set the default value but first you must set the Nullable property to true in your dbml file in the required field (xx.Online)

var hht = from x in db.HandheldAssets
        join a in db.HandheldDevInfos on x.AssetID equals a.DevName into DevInfo
        from aa in DevInfo.DefaultIfEmpty()
        select new
        AssetID = x.AssetID,
        Status = xx.Online ?? false

Have a reloadData for a UITableView animate when changing

I can't comment on the top answer, but a swift implementation would be:

self.tableView.reloadSections([0], with: UITableViewRowAnimation.fade)

you could include as many sections as you want to update in the first argument for reloadSections.

Other animations available from the docs:

fade The inserted or deleted row or rows fade into or out of the table view.

right The inserted row or rows slide in from the right; the deleted row or rows slide out to the right.

left The inserted row or rows slide in from the left; the deleted row or rows slide out to the left.

top The inserted row or rows slide in from the top; the deleted row or rows slide out toward the top.

bottom The inserted row or rows slide in from the bottom; the deleted row or rows slide out toward the bottom.

case none The inserted or deleted rows use the default animations.

middle The table view attempts to keep the old and new cells centered in the space they did or will occupy. Available in iPhone 3.2.

automatic The table view chooses an appropriate animation style for you. (Introduced in iOS 5.0.)

Delete all nodes and relationships in neo4j 1.8

Neo4j cannot delete nodes that have a relation. You have to delete the relations before you can delete the nodes.

But, it is simple way to delete "ALL" nodes and "ALL" relationships with a simple chyper. This is the code:


--> DETACH DELETE will remove all of the nodes and relations by Match

How to set the current working directory?

import os
print os.getcwd()  # Prints the current working directory

To set the working directory:

os.chdir('c:\\Users\\uname\\desktop\\python')  # Provide the new path here

What is the difference between XML and XSD?

Basically an XSD file defines how the XML file is going to look like. It's a Schema file which defines the structure of the XML file. So it specifies what the possible fields are and what size they are going to be.

An XML file is an instance of XSD as it uses the rules defined in the XSD.

Show and hide a View with a slide up/down animation

You can start the correct Animation when the visibility of the LinearLayout changes by creating a new subclass of LinearLayout and overriding setVisibility() to start the Animations. Consider something like this:

public class SimpleViewAnimator extends LinearLayout
    private Animation inAnimation;
    private Animation outAnimation;

    public SimpleViewAnimator(Context context)

    public void setInAnimation(Animation inAnimation)
        this.inAnimation = inAnimation;

    public void setOutAnimation(Animation outAnimation)
        this.outAnimation = outAnimation;

    public void setVisibility(int visibility)
        if (getVisibility() != visibility)
            if (visibility == VISIBLE)
                if (inAnimation != null) startAnimation(inAnimation);
            else if ((visibility == INVISIBLE) || (visibility == GONE))
                if (outAnimation != null) startAnimation(outAnimation);


Cannot deserialize the current JSON array (e.g. [1,2,3])

You can use this to solve your problem:

private async void btn_Go_Click(object sender, RoutedEventArgs e)
    HttpClient webClient = new HttpClient();
    Uri uri = new Uri("" + txtVCode.Text);
    HttpResponseMessage response = await webClient.GetAsync(uri);
    var jsonString = await response.Content.ReadAsStringAsync();
    var _Data = JsonConvert.DeserializeObject <List<Student>>(jsonString);
    foreach (Student Student in _Data)
        tb1.Text = Student.student_name;

How to clear/delete the contents of a Tkinter Text widget?

this works

import tkinter as tk

How to get .pem file from .key and .crt files?

Additionally, if you don't want it to ask for a passphrase, then need to run the following command:

openssl rsa -in server.key -out server.key

How to find list intersection?

This is an example when you need Each element in the result should appear as many times as it shows in both arrays.

def intersection(nums1, nums2):
    #nums1 = [1,2,2,1]
    #nums2 = [2,2]
    #output = [2,2]
    #find first 2 and remove from target, continue iterating

    target, iterate = [nums1, nums2] if len(nums2) >= len(nums1) else [nums2, nums1] #iterate will look into target

    if len(target) == 0:
            return []

    i = 0
    store = []
    while i < len(iterate):

         element = iterate[i]

         if element in target:

         i += 1

    return store

Android SDK is missing, out of date, or is missing templates. Please ensure you are using SDK version 22 or later

1.Click on Configure

2.Then Choose Project Defaults

3.Click on Project Structure

4.Set android sdk path

You will find here "C:\User\YourPcname\AppData\Local\SDK"

Note: Sometime AppData may hidden if it will not show then enable show hidden content.

5.Apply Changes

6.Then Select Sdk From Configure option

7.Then Android sdk manager page is open

8.In bottom you will see Install packages option

9.Install them and enjoy.

How do I change the background color of a plot made with ggplot2

To avoid deprecated opts and theme_rect use:

myplot + theme(panel.background = element_rect(fill='green', colour='red'))

To define your own custom theme, based on theme_gray but with some of your changes and a few added extras including control of gridline colour/size (more options available to play with at

theme_jack <- function (base_size = 12, base_family = "") {
    theme_gray(base_size = base_size, base_family = base_family) %+replace% 
            axis.text = element_text(colour = "white"),
            axis.title.x = element_text(colour = "pink", size=rel(3)),
            axis.title.y = element_text(colour = "blue", angle=45),
            panel.background = element_rect(fill="green"),
            panel.grid.minor.y = element_line(size=3),
            panel.grid.major = element_line(colour = "orange"),
            plot.background = element_rect(fill="red")

To make your custom theme the default when ggplot is called in future, without masking:


If you want to change an element of the currently set theme:

theme_update(plot.background = element_rect(fill="pink"), axis.title.x = element_text(colour = "red"))

To store the current default theme as an object:

theme_pink <- theme_get()

Note that theme_pink is a list whereas theme_jack was a function. So to return the theme to theme_jack use theme_set(theme_jack()) whereas to return to theme_pink use theme_set(theme_pink).

You can replace theme_gray by theme_bw in the definition of theme_jack if you prefer. For your custom theme to resemble theme_bw but with all gridlines (x, y, major and minor) turned off:

theme_nogrid <- function (base_size = 12, base_family = "") {
    theme_bw(base_size = base_size, base_family = base_family) %+replace% 
            panel.grid = element_blank()

Finally a more radical theme useful when plotting choropleths or other maps in ggplot, based on discussion here but updated to avoid deprecation. The aim here is to remove the gray background, and any other features that might distract from the map.

theme_map <- function (base_size = 12, base_family = "") {
    theme_gray(base_size = base_size, base_family = base_family) %+replace% 
            axis.ticks.length=unit(0.3, "lines"),
            axis.ticks.margin=unit(0.5, "lines"),
            legend.background=element_rect(fill="white", colour=NA),
            legend.key.size=unit(1.2, "lines"),
            legend.title=element_text(size=rel(0.8), face="bold", hjust=0),
            panel.margin=unit(0, "lines"),
            plot.margin=unit(c(1, 1, 0.5, 0.5), "lines"),
            strip.background=element_rect(fill="grey90", colour="grey50"),
            strip.text.y=element_text(size=rel(0.8), angle=-90) 

Parsing date string in Go

This might be super late, but this is for people that might stumble on this problem and might want to use external package for parsing date string.

I've tried looking for a libraries and I found this one:

Example from the README:

package main

import (


var examples = []string{
    "May 8, 2009 5:57:51 PM",
    "Mon Jan  2 15:04:05 2006",
    "Mon Jan  2 15:04:05 MST 2006",
    "Mon Jan 02 15:04:05 -0700 2006",
    "Monday, 02-Jan-06 15:04:05 MST",
    "Mon, 02 Jan 2006 15:04:05 MST",
    "Tue, 11 Jul 2017 16:28:13 +0200 (CEST)",
    "Mon, 02 Jan 2006 15:04:05 -0700",
    "Thu, 4 Jan 2018 17:53:36 +0000",
    "Mon Aug 10 15:44:11 UTC+0100 2015",
    "Fri Jul 03 2015 18:04:07 GMT+0100 (GMT Daylight Time)",
    "12 Feb 2006, 19:17",
    "12 Feb 2006 19:17",
    "03 February 2013",
    //   mm/dd/yy
    "4/8/2014 22:05",
    "04/08/2014 22:05",
    "4/8/14 22:05",
    "04/2/2014 03:00:51",
    "8/8/1965 12:00:00 AM",
    "8/8/1965 01:00:01 PM",
    "8/8/1965 01:00 PM",
    "8/8/1965 1:00 PM",
    "8/8/1965 12:00 AM",
    "4/02/2014 03:00:51",
    "03/19/2012 10:11:59",
    "03/19/2012 10:11:59.3186369",
    // yyyy/mm/dd
    "2014/4/8 22:05",
    "2014/04/08 22:05",
    "2014/04/2 03:00:51",
    "2014/4/02 03:00:51",
    "2012/03/19 10:11:59",
    "2012/03/19 10:11:59.3186369",
    // Chinese
    //   yyyy-mm-ddThh
    //   yyyy-mm-dd hh:mm:ss
    "2014-04-26 17:24:37.3186369",
    "2012-08-03 18:31:59.257000000",
    "2014-04-26 17:24:37.123",
    "2013-04-01 22:43",
    "2013-04-01 22:43:22",
    "2014-12-16 06:20:00 UTC",
    "2014-12-16 06:20:00 GMT",
    "2014-04-26 05:24:37 PM",
    "2014-04-26 13:13:43 +0800",
    "2014-04-26 13:13:44 +09:00",
    "2012-08-03 18:31:59.257000000 +0000 UTC",
    "2015-09-30 18:48:56.35272715 +0000 UTC",
    "2015-02-18 00:12:00 +0000 GMT",
    "2015-02-18 00:12:00 +0000 UTC",
    "2017-07-19 03:21:51+00:00",
    "2014-05-11 08:20:13,787",
    // mm.dd.yy
    //  yyyymmdd and similar
    // unix seconds, ms

var (
    timezone = ""

func main() {
    flag.StringVar(&timezone, "timezone", "UTC", "Timezone aka `America/Los_Angeles` formatted time-zone")

    if timezone != "" {
        // NOTE:  This is very, very important to understand
        // time-parsing in go
        loc, err := time.LoadLocation(timezone)
        if err != nil {
        time.Local = loc

    table := termtables.CreateTable()

    table.AddHeaders("Input", "Parsed, and Output as %v")
    for _, dateExample := range examples {
        t, err := dateparse.ParseLocal(dateExample)
        if err != nil {
        table.AddRow(dateExample, fmt.Sprintf("%v", t))

How to convert "0" and "1" to false and true

If you don't want to convert.Just use;

 bool _status = status == "1" ? true : false;

Perhaps you will return the values as you want.

Viewing all defined variables

As RedBlueThing and analog said:

  • dir() gives a list of in scope variables
  • globals() gives a dictionary of global variables
  • locals() gives a dictionary of local variables

Using the interactive shell (version 2.6.9), after creating variables a = 1 and b = 2, running dir() gives

['__builtins__', '__doc__', '__name__', '__package__', 'a', 'b']

running locals() gives

{'a': 1, 'b': 2, '__builtins__': <module '__builtin__' (built-in)>, '__package__': None, '__name__': '__main__', '__doc__': None}

Running globals() gives exactly the same answer as locals() in this case.

I haven't gotten into any modules, so all the variables are available as both local and global variables. locals() and globals() list the values of the variables as well as the names; dir() only lists the names.

If I import a module and run locals() or globals() inside the module, dir() still gives only a small number of variables; it adds __file__ to the variables listed above. locals() and globals() also list the same variables, but in the process of printing out the dictionary value for __builtin__, it lists a far larger number of variables: built-in functions, exceptions, and types such as "'type': <type 'type'>", rather than just the brief <module '__builtin__' (built-in)> as shown above.

For more about dir() see Python 2.7 quick reference at New Mexico Tech or the dir() function at

For more about locals() and globals() see locals and globals at Dive Into Python and a page about globals at New Mexico Tech.

[Comment: @Kurt: You gave a link to enumerate-or-list-all-variables-in-a-program-of-your-favorite-language-here but that answer has a mistake in it. The problem there is: type(name) in that example will always return <type 'str'>. You do get a list of the variables, which answers the question, but with incorrect types listed beside them. This was not obvious in your example because all the variables happened to be strings anyway; however, what it's returning is the type of the name of the variable instead of the type of the variable. To fix this: instead of print type(name) use print eval('type(' + name + ')'). I apologize for posting a comment in the answer section but I don't have comment posting privileges, and the other question is closed.]

How to connect to remote Oracle DB with PL/SQL Developer?

I would recommend creating a TNSNAMES.ORA file. From your Oracle Client install directory, navigate to NETWORK\ADMIN. You may already have a file called TNSNAMES.ORA, if so edit it, else create it using your favorite text editor.

Next, simply add an entry like this:

    (ADDRESS = (PROTOCOL = TCP)(HOST = = 1521))

You can change MYDB to whatever you like, this is the identifier that applications will will use to find the database using the info from TNSNAMES.

Finally, login with MYDB as your database in PL/SQL Developer. It should automatically find the connection string in the TNSNAMES.ORA.

If that does not work, hit Help->About then click the icon with an "i" in it in the upper-lefthand corner. The fourth tab is the "TNS Names" tab, check it to confirm that it is loading the proper TNSNAMES.ORA file. If it is not, you may have multiple Oracle installations on your computer, and you will need to find the one that is in use.

Matching strings with wildcard

It is necessary to take into consideration, that Regex IsMatch gives true with XYZ, when checking match with Y*. To avoid it, I use "^" anchor

isMatch(str1, "^" + str2.Replace("*", ".*?"));  

So, full code to solve your problem is

    bool isMatchStr(string str1, string str2)
        string s1 = str1.Replace("*", ".*?");
        string s2 = str2.Replace("*", ".*?");
        bool r1 = Regex.IsMatch(s1, "^" + s2);
        bool r2 = Regex.IsMatch(s2, "^" + s1);
        return r1 || r2;

Setting width as a percentage using jQuery

Using the width function:


will turn:

<div id="somediv" />


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

What is a daemon thread in Java?

Daemon threads are as everybody explained, will not constrain JVM to exit, so basically its a happy thread for Application from exit point of view.

Want to add that daemon threads can be used when say I'm providing an API like pushing data to a 3rd party server / or JMS, I might need to aggregate data at the client JVM level and then send to JMS in a separate thread. I can make this thread as daemon thread, if this is not a mandatory data to be pushed to server. This kind of data is like log push / aggregation.

Regards, Manish

Javascript Iframe innerHTML


Convert time.Time to string


How to delete multiple rows in SQL where id = (x to y)

,@ERRFLAG  CHAR(1) = '0' OUTPUT    



DELETE tb_SampleTest
        CODE IN(
            SELECT Item.value('.', 'VARCHAR(20)')
            FROM  @CODE.nodes('RecordList/ID') AS x(Item)

    SET @ERRFLAG = 200


Get string value delete


How to test an Oracle Stored Procedure with RefCursor return type?

In SQL Developer you can right-click on the package body then select RUN. The 'Run PL/SQL' window will let you edit the PL/SQL Block. Clicking OK will give you a window pane titled 'Output Variables - Log' with an output variables tab. You can select your output variables on the left and the result is shown on the right side. Very handy and fast.

I've used Rapid with T-SQL and I think there was something similiar to this.

Writing your own delcare-begin-end script where you loop through the cursor, as with DCookie's example, is always a good exercise to do every now and then. It will work with anything and you will know that your code works.

How do I create a Linked List Data Structure in Java?

//slightly improved code without using collection framework

package com.test;

public class TestClass {

    private static Link last;
    private static Link first;

    public static void main(String[] args) {

        for(int i=0;i<5;i++){


    protected  static class Link {
        private int data;
        private Link nextlink;

        public Link(int d1) {
   = d1;

        public static void insert(int d1) {
            Link a = new Link(d1);
            a.nextlink = null;
            if (first != null) {
                last.nextlink = a;
                last = a;
            } else {
                first = a;
                last = a;
            System.out.println("Inserted -:"+d1);

        public static void deletefromFirst() {
                System.out.println("Deleting -:";
                first = first.nextlink;
                System.out.println("No elements in Linked List");

        public static void printList() {
            System.out.println("Elements in the list are");
            Link temp = first;
            while (temp != null) {
                temp = temp.nextlink;

Android Studio marks R in red with error message "cannot resolve symbol R", but build succeeds

Just Click on Build -> Rebuild Project option in your Android Studio.

XPath: select text node

Having the following XML:


How do I select either the first or the second text node via XPath?



This selects all text-node children of the top element (named "node") of the XML document.


This selects the first text-node child of the top element (named "node") of the XML document.


This selects the second text-node child of the top element (named "node") of the XML document.


This selects the someInteger-th text-node child of the top element (named "node") of the XML document. It is equivalent to the following XPath expression:

/node/text()[position() = someInteger]

Extracting Path from OpenFileDialog path/filename

if (openFileDialog1.ShowDialog(this) == DialogResult.OK)
    strfilename = openFileDialog1.InitialDirectory + openFileDialog1.FileName;

How to get the current directory in a C program?

Have you had a look at getcwd()?

#include <unistd.h>
char *getcwd(char *buf, size_t size);

Simple example:

#include <unistd.h>
#include <stdio.h>
#include <limits.h>

int main() {
   char cwd[PATH_MAX];
   if (getcwd(cwd, sizeof(cwd)) != NULL) {
       printf("Current working dir: %s\n", cwd);
   } else {
       perror("getcwd() error");
       return 1;
   return 0;

How to use the ConfigurationManager.AppSettings

ConfigurationManager.AppSettings is actually a property, so you need to use square brackets.

Overall, here's what you need to do:

SqlConnection con= new SqlConnection(ConfigurationManager.AppSettings["ConnectionString"]);

The problem is that you tried to set con to a string, which is not correct. You have to either pass it to the constructor or set con.ConnectionString property.

Javascript date regex DD/MM/YYYY

Scape slashes is simply use \ before / and it will be escaped. (\/=> /).

Otherwise you're regex DD/MM/YYYY could be next:



  • [0-9]: Just Numbers
  • {2} or {4}: Length 2 or 4. You could do {2,4} as well to length between two numbers (2 and 4 in this case)
  • [\/]: Character /
  • g : Global -- Or m: Multiline (Optional, see your requirements)
  • $: Anchor to end of string. (Optional, see your requirements)
  • ^: Start of string. (Optional, see your requirements)

An example of use:

var regex = /^[0-9]{2}[\/][0-9]{2}[\/][0-9]{4}$/g;

var dates = ["2009-10-09", "2009.10.09", "2009/10/09", "200910-09", "1990/10/09", 
    "2016/0/09", "2017/10/09", "2016/09/09", "20/09/2016", "21/09/2016", "22/09/2016",
    "23/09/2016", "19/09/2016", "18/09/2016", "25/09/2016", "21/09/2018"];

//Iterate array
        console.log(date + " matches with regex?");

Of course you can use as boolean:

     //do something

How to add an image to the "drawable" folder in Android Studio?

Copy the image then paste it to drawables in the resource folder of you project in android studio.Make sure the name of your image is not too long and does not have any spacial characters.Then click SRC(source) under properties and look for your image click on it then it will automatically get imported to you image view on you emulator.

querying WHERE condition to character length?

Sorry, I wasn't sure which SQL platform you're talking about:


$query = ("SELECT * FROM $db WHERE conditions AND LENGTH(col_name) = 3");


$query = ("SELECT * FROM $db WHERE conditions AND LEN(col_name) = 3");

The LENGTH() (MySQL) or LEN() (MSSQL) function will return the length of a string in a column that you can use as a condition in your WHERE clause.


I know this is really old but thought I'd expand my answer because, as Paulo Bueno rightly pointed out, you're most likely wanting the number of characters as opposed to the number of bytes. Thanks Paulo.

So, for MySQL there's the CHAR_LENGTH(). The following example highlights the difference between LENGTH() an CHAR_LENGTH():

    word VARCHAR(100)
) ENGINE INNODB DEFAULT CHARSET utf8mb4 COLLATE utf8mb4_unicode_ci;

INSERT INTO words(word) VALUES('??'), ('happy'), ('hayir');

SELECT word, LENGTH(word) as num_bytes, CHAR_LENGTH(word) AS num_characters FROM words;

| word   | num_bytes | num_characters |
| ??    |         6 |              2 |
| happy  |         5 |              5 |
| hayir  |         6 |              5 |

Be careful if you're dealing with multi-byte characters.

Sort a list of tuples by 2nd item (integer value)

>>> from operator import itemgetter
>>> data = [('abc', 121),('abc', 231),('abc', 148), ('abc',221)]
>>> sorted(data,key=itemgetter(1))
[('abc', 121), ('abc', 148), ('abc', 221), ('abc', 231)]

IMO using itemgetter is more readable in this case than the solution by @cheeken. It is also faster since almost all of the computation will be done on the c side (no pun intended) rather than through the use of lambda.

>python -m timeit -s "from operator import itemgetter; data = [('abc', 121),('abc', 231),('abc', 148), ('abc',221)]" "sorted(data,key=itemgetter(1))"
1000000 loops, best of 3: 1.22 usec per loop

>python -m timeit -s "data = [('abc', 121),('abc', 231),('abc', 148), ('abc',221)]" "sorted(data,key=lambda x: x[1])"
1000000 loops, best of 3: 1.4 usec per loop

SQL Server CTE and recursion example

    --DROP TABLE #Employee
    CREATE TABLE #Employee(EmpId BIGINT IDENTITY,EmpName VARCHAR(25),Designation VARCHAR(25),ManagerID BIGINT)

    INSERT INTO #Employee VALUES('M11M','Manager',NULL)
    INSERT INTO #Employee VALUES('P11P','Manager',NULL)

    INSERT INTO #Employee VALUES('AA','Clerk',1)
    INSERT INTO #Employee VALUES('AB','Assistant',1)
    INSERT INTO #Employee VALUES('ZC','Supervisor',2)
    INSERT INTO #Employee VALUES('ZD','Security',2)

    SELECT * FROM #Employee (NOLOCK)

    WITH Emp_CTE 
        SELECT EmpId,EmpName,Designation, ManagerID
              ,CASE WHEN ManagerID IS NULL THEN EmpId ELSE ManagerID END ManagerID_N
        FROM #Employee  
    select EmpId,EmpName,Designation, ManagerID
    FROM Emp_CTE
    order BY ManagerID_N, EmpId

Add table row in jQuery

if you have another variable you can access in <td> tag like that try.

This way I hope it would be helpful

var table = $('#yourTableId');
var text  = 'My Data in td';
var image = 'your/image.jpg'; 
var tr = (
  '<tr>' +
    '<td>'+ text +'</td>'+
    '<td>'+ text +'</td>'+
      '<img src="' + image + '" alt="yourImage">'+


Is there a difference between "throw" and "throw ex"?

let's understand the difference between throw and throw ex. I heard that in many .net interviews this common asked is being asked.

Just to give an overview of these two terms, throw and throw ex are both used to understand where the exception has occurred. Throw ex rewrites the stack trace of exception irrespective where actually has been thrown.

Let's understand with an example.

Let's understand first Throw.

static void Main(string[] args) {
    try {
    } catch (Exception ex) {
        Console.WriteLine(" -----------------Stack Trace Hierarchy -----------------");
        Console.WriteLine(" ---------------- Method Name / Target Site -------------- ");

static void M1() {
    try {
    } catch (Exception ex) {

static void M2() {
    throw new DivideByZeroException();

output of the above is below.

shows complete hierarchy and method name where actually the exception has thrown.. it is M2 -> M2. along with line numbers

enter image description here

Secondly.. lets understand by throw ex. Just replace throw with throw ex in M2 method catch block. as below.

enter image description here

output of throw ex code is as below..

enter image description here

You can see the difference in the output.. throw ex just ignores all the previous hierarchy and resets stack trace with line/method where throw ex is written.

POST data in JSON format

Here is an example using jQuery...

   <script type="text/javascript" src=""></script>
   <script type="text/javascript" src=""></script>
   <script type="text/javascript">
     $(function() {
       var frm = $(document.myform);
       var dat = JSON.stringify(frm.serializeArray());

       alert("I am about to POST this:\n\n" + dat);

         function(data) {
           alert("Response: " + data);

The jQuery serializeArray function creates a Javascript object with the form values. Then you can use JSON.stringify to convert that into a string, if needed. And you can remove your body onload, too.

JFrame background image

You can do:

setContentPane(new JLabel(new ImageIcon("resources/taverna.jpg")));

At first line of the Jframe class constructor, that works fine for me

How can I pass POST parameters in a URL?

I would like to share my implementation as well. It does require some JavaScript code though.

<form action="./index.php" id="homePage" method="post" style="display: none;">
    <input type="hidden" name="action" value="homePage" />

<a href="javascript:;" onclick="javascript:

The nice thing about this is that, contrary to GET requests, it doesn't show the parameters in the URL, which is safer.

How do I set multipart in axios with react?

If you are sending alphanumeric data try changing

'Content-Type': 'multipart/form-data'


'Content-Type': 'application/x-www-form-urlencoded'

If you are sending non-alphanumeric data try to remove 'Content-Type' at all.

If it still does not work, consider trying request-promise (at least to test whether it is really axios problem or not)

What's the location of the JavaFX runtime JAR file, jfxrt.jar, on Linux?

The location of jfxrt.jar in JDK 1.8 (Windows) is:

C:\Program Files\Java\jdk1.8.0_05\jre\lib\ext\jfxrt.jar

Visual Studio Code: format is not using indent settings

I sometimes have this same problem. VSCode will just suddenly lose it's mind and completely ignore any indentation setting I tell it, even though it's been indenting the same file just fine all day.

I have editor.tabSize set to 2 (as well as editor.formatOnSave set to true). When VSCode messes up a file, I use the options at the bottom of the editor to change indentation type and size, hoping something will work, but VSCode insists on actually using an indent size of 4.

The fix? Restart VSCode. It should come back with the indent status showing something wrong (in my case, 4). For me, I had to change the setting and then save for it to actually make the change, but that's probably because of my editor.formatOnSave setting.

I haven't figured out why it happens, but for me it's usually when I'm editing a nested object in a JS file. It will suddenly do very strange indentation within the object, even though I've been working in that file for a while and it's been indenting just fine.


Hai sridhar, I found an answer for your prob

ClientScript.RegisterClientScriptBlock(GetType(), "sas", "<script> alert('Inserted successfully');</script>", true);

change false to true

or try this

ScriptManager.RegisterClientScriptBlock(ursavebuttonID, typeof(LinkButton or button), "sas", "<script> alert('Inserted successfully');</script>", true);

SQL Server 2005 Using CHARINDEX() To split a string

Create FUNCTION [dbo].[fnSplitString] 
    @string NVARCHAR(200), 
    @delimiter CHAR(1) 
RETURNS @output TABLE(splitdata NVARCHAR(10) 
    DECLARE @start INT, @end INT 
    SELECT @start = 1, @end = CHARINDEX(@delimiter, @string) 
    WHILE @start < LEN(@string) + 1 BEGIN 
        IF @end = 0  
            SET @end = LEN(@string) + 1

        INSERT INTO @output (splitdata)  
        VALUES(SUBSTRING(@string, @start, @end - @start)) 
        SET @start = @end + 1 
        SET @end = CHARINDEX(@delimiter, @string, @start)


END**strong text**

Parse JSON in TSQL

SQL server 2016 supports json data parsing using OPENJSON. You can use OPENJSON to map json data to rows and columns.

Your json Data

 { "id" : 2,"name": "John"},
 { "id" : 5,"name": "John"}

Here is how you can handle json in sql

//@pJson is json data passed from code.  

INSERT INTO YourTable (id, Name)
 SELECT id, name
 WITH (id int,
       name nvarchar(max))

Here is a detailed article which covers this topic.

pandas get column average/mean

you can use


you will get basic statistics of the dataframe and to get mean of specific column you can use


No found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations:

I just solved this error happening in my tests.

Just make sure your test class has all dependencies in the attributes of the class being tested annotated with @MockBean so SpringBoot test context can wire your classes correctly.

Only if you are testing controller: you need also class annotations to load the Controller context propertly.

Check it out:

@DisplayName("UserController Adapter Test")
@AutoConfigureMockMvc(addFilters = false)
public class UserControllerTest {

private MockMvc mockMvc;

private ObjectMapper objectMapper;

private CreateUserCommand createUserCommand;

private GetUserListQuery getUserListQuery;

private GetUserQuery getUserQuery;

Swift - iOS - Dates and times in different format

extension String {

    func convertDatetring_TopreferredFormat(currentFormat: String, toFormat : String) ->  String {
        let dateFormator = DateFormatter()
        dateFormator.dateFormat = currentFormat
        let resultDate = self)
        dateFormator.dateFormat = toFormat
        return dateFormator.string(from: resultDate!)


Call from your view controller file as below.

"your_date_string".convertDatetring_TopreferredFormat(currentFormat: "yyyy-MM-dd HH:mm:ss.s", toFormat: "dd-MMM-yyyy h:mm a")

twitter bootstrap navbar fixed top overlapping site

use this class inside nav tag

class="navbar navbar-expand-lg navbar-light bg-light sticky-top"

For bootstrap 4

NSUserDefaults - How to tell if a key exists

Swift 3.0

if NSUserDefaults.standardUserDefaults().dictionaryRepresentation().contains({ $0.0 == "Your_Comparison_Key" }){
                    result = NSUserDefaults.standardUserDefaults().objectForKey(self.ticketDetail.ticket_id) as! String

Simpler way to check if variable is not equal to multiple string values?

You need to multi value check. Try using the following code :

    if(count(array_intersect($illstack,$val))===count($val)){ // all of $val is in $illstack}

How to do the Recursive SELECT query in MySQL?


Solution mentioned by @leftclickben is also effective. We can also use a stored procedure for the same.

CREATE PROCEDURE get_tree(IN id int)
 DECLARE child_id int;
 DECLARE prev_id int;
 SET prev_id = id;
 SET child_id=0;
 SELECT col3 into child_id 
 FROM table1 WHERE col1=id ;
 create TEMPORARY  table IF NOT EXISTS temp_table as (select * from table1 where 1=0);
 truncate table temp_table;
 WHILE child_id <> 0 DO
   insert into temp_table select * from table1 WHERE col1=prev_id;
   SET prev_id = child_id;
   SET child_id=0;
   SELECT col3 into child_id
   FROM TABLE1 WHERE col1=prev_id;
 select * from temp_table;
 END //

We are using temp table to store results of the output and as the temp tables are session based we wont there will be not be any issue regarding output data being incorrect.


Try this query:

    col1, col2, @pv := col3 as 'col3' 
    (SELECT @pv := 1) tmp
    col1 = @pv


| COL1 | COL2 | COL3 |
|    1 |    a |    5 |
|    5 |    d |    3 |
|    3 |    k |    7 |

parent_id value should be less than the child_id for this solution to work.

Response.Redirect to new window

I just found the answer and it works :)

You need to add the following to your server side link/button:

OnClientClick=" ='_blank';"

My entire button code looks something like:

<asp:LinkButton ID="myButton" runat="server" Text="Click Me!" 
                OnClientClick=" ='_blank';"/>

In the server side OnClick I do a Response.Redirect("MyPage.aspx"); and the page is opened in a new window.

The other part you need to add is to fix the form's target otherwise every link will open in a new window. To do so add the following in the header of your POPUP window.

<script type="text/javascript">
    function fixform() {
        if (opener.document.getElementById("aspnetForm").target != "_blank") return;
        opener.document.getElementById("aspnetForm").target = "";
        opener.document.getElementById("aspnetForm").action = opener.location.href;


<body onload="fixform()">

Difference between a theta join, equijoin and natural join

A theta join allows for arbitrary comparison relationships (such as ≥).

An equijoin is a theta join using the equality operator.

A natural join is an equijoin on attributes that have the same name in each relationship.

Additionally, a natural join removes the duplicate columns involved in the equality comparison so only 1 of each compared column remains; in rough relational algebraic terms: ? = pR,S-as ? ?aR=aS

How does Junit @Rule work?

The explanation for how it works:

JUnit wraps your test method in a Statement object so statement and Execute() runs your test. Then instead of calling statement.Execute() directly to run your test, JUnit passes the Statement to a TestRule with the @Rule annotation. The TestRule's "apply" function returns a new Statement given the Statement with your test. The new Statement's Execute() method can call the test Statement's execute method (or not, or call it multiple times), and do whatever it wants before and after.

Now, JUnit has a new Statement that does more than just run the test, and it can again pass that to any more rules before finally calling Execute.

Get the Highlighted/Selected text

Get highlighted text this way:


and of course a special treatment for ie:


Return current date plus 7 days

strtotime will automatically use the current unix timestamp to base your string annotation off of.

Just do:

$date = strtotime("+7 day");
echo date('M d, Y', $date);

Added Info For Future Visitors: If you need to pass a timestamp to the function, the below will work.

This will calculate 7 days from yesterday:

$timestamp = time()-86400;

$date = strtotime("+7 day", $timestamp);
echo date('M d, Y', $date);

How can I send an HTTP POST request to a server from Excel using VBA?

I did this before using the MSXML library and then using the XMLHttpRequest object, see here.

How do I check CPU and Memory Usage in Java?

Since Java 1.5 the JDK comes with a new tool: JConsole wich can show you the CPU and memory usage of any 1.5 or later JVM. It can do charts of these parameters, export to CSV, show the number of classes loaded, the number of instances, deadlocks, threads etc...

How can I make a "color map" plot in matlab?

gevang's answer is great. There's another way as well to do this directly by using pcolor. Code:

[X,Y] = meshgrid(-8:.5:8);
R = sqrt(X.^2 + Y.^2) + eps;
Z = sin(R)./R;
pcolor(X,Y,Z); shading flat;
pcolor(X,Y,Z); shading interp;


enter image description here

Also, pcolor is flat too, as show here (pcolor is the 2d base; the 3d figure above it is generated using mesh):

enter image description here

Comparing arrays in JUnit assertions, concise built-in way?

Class Assertions in org.junit.jupiter.api


public static void assertArrayEquals(int[] expected,
                                     int[] actual)

Div height 100% and expands to fit content

Here is what you should do in the CSS style, on the main div

display: block;
overflow: auto;

And do not touch height

Creating a custom JButton in Java

When I was first learning Java we had to make Yahtzee and I thought it would be cool to create custom Swing components and containers instead of just drawing everything on one JPanel. The benefit of extending Swing components, of course, is to have the ability to add support for keyboard shortcuts and other accessibility features that you can't do just by having a paint() method print a pretty picture. It may not be done the best way however, but it may be a good starting point for you.

Edit 8/6 - If it wasn't apparent from the images, each Die is a button you can click. This will move it to the DiceContainer below. Looking at the source code you can see that each Die button is drawn dynamically, based on its value.

alt text
alt text
alt text

Here are the basic steps:

  1. Create a class that extends JComponent
  2. Call parent constructor super() in your constructors
  3. Make sure you class implements MouseListener
  4. Put this in the constructor:

  5. Override these methods:

    public Dimension getPreferredSize()  
    public Dimension getMinimumSize()  
    public Dimension getMaximumSize()
  6. Override this method:

    public void paintComponent(Graphics g)

The amount of space you have to work with when drawing your button is defined by getPreferredSize(), assuming getMinimumSize() and getMaximumSize() return the same value. I haven't experimented too much with this but, depending on the layout you use for your GUI your button could look completely different.

And finally, the source code. In case I missed anything.

How to set image in imageview in android?

1> You can add image from layout itself:

                android:padding="2dp" />


2> Programmatically in java class:

ImageView ivYouImage= (ImageView)findViewById(;

OR for fragments:

View rowView= inflater.inflate(R.layout.your_layout, null, true);

ImageView ivYouImage= (ImageView) rowView.findViewById(;

Using comma as list separator with AngularJS

I like simbu's approach, but I ain't comfortable to use first-child or last-child. Instead I only modify the content of a repeating list-comma class.

.list-comma + .list-comma::before {
    content: ', ';
<span class="list-comma" ng-repeat="destination in destinations">

Controlling Spacing Between Table Cells

Check this fiddle. You are going to need to take a look at using border-collapse and border-spacing. There are some quirks for IE (as usual). This is based on an answer to this question.

table.test td {
  background-color: lime;
  margin: 12px 12px 12px 12px;
  padding: 12px 12px 12px 12px;

table.test {
  border-collapse: separate;
  border-spacing: 10px;
  *border-collapse: expression('separate', cellSpacing='10px');
<table class="test">

How do I use InputFilter to limit characters in an EditText in Android?

This is an old thread, but the purposed solutions all have issues (depending on device / Android version / Keyboard).


So eventually I went with a different approach, instead of using the InputFilter problematic implementation, I am using TextWatcher and the TextChangedListener of the EditText.


editText.addTextChangedListener(new TextWatcher() {

    public void afterTextChanged(Editable editable) {

        String originalText = editable.toString();
        int originalTextLength = originalText.length();
        int currentSelection = editText.getSelectionStart();

        // Create the filtered text
        StringBuilder sb = new StringBuilder();
        boolean hasChanged = false;
        for (int i = 0; i < originalTextLength; i++) {
            char currentChar = originalText.charAt(i);
            if (isAllowed(currentChar)) {
            } else {
                hasChanged = true;
                if (currentSelection >= i) {

        // If we filtered something, update the text and the cursor location
        if (hasChanged) {
            String newText = sb.toString();

    private boolean isAllowed(char c) {
        // TODO: Add the filter logic here
        return Character.isLetter(c) || Character.isSpaceChar(c);
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        // Do Nothing

    public void onTextChanged(CharSequence s, int start, int before, int count) {
        // Do Nothing

The reason InputFilter is not a good solution in Android is since it depends on the keyboard implementation. The Keyboard input is being filtered before the input is passed to the EditText. But, because some keyboards have different implementations for the InputFilter.filter() invocation, this is problematic.

On the other hand TextWatcher does not care about the keyboard implementation, it allows us to create a simple solution and be sure it will work on all devices.

How to include External CSS and JS file in Laravel 5

Ok so I was able to figure out for the version 5.2. You will first need to create assets folder in your public folder then put css folder and all css files into it then link it like this :

<link href="assets/css/bootstrap.min.css" rel="stylesheet">

Hope that helps!

Accessing localhost of PC from USB connected Android mobile device

I very much liked John's answer, but I'd like to give it with some changes to those that want to test some client//server configuration by running a client TCP on the USB connected Mobile and a server on the local PC.

First it's quite obvious that the won't work because this is a REAL hardware mobile and not a simulator.

So Follow John's instructions:

  • Unplug all network cables on PC and turn off wifi.
  • Turn off wifi on the android device
  • Connect android device to pc via USB
  • Turn on the "USB Tethering" (USB Modem/ USB Cellular Modem / USB ????? ????? ??????) in the android menu. (Under networks->more...->Tethering and portable hotspot")

    • This USB connection will act as a DHCP server for you single PC connection, so it'll assign your PC a dedicated (dynamic) IP in its local USB network. Now all you have to do is tell the client application this IP and port.
  • Get the IP of your PC (that has been assigned by the USB tether cable.) (open command prompt and type "ipconfig" then look for the IP that the USB network adapter has assigned, in Linux its ifconfig or Ubuntu's "Connection information" etc..)

  • Tell the application to connect to that IP (i.e. with something like (Java - client side):

    String        serverIP      = "";
    int           serverPort    = 5544;
    InetAddress   serverAddress = InetAddress.getByName(serverIP);
    Socket        socket         = new Socket(serverAddress, serverPort);


Getting vertical gridlines to appear in line plot in matplotlib

For only horizontal lines

ax = plt.axes()        
ax.yaxis.grid() # horizontal lines

This worked

How to read a CSV file into a .NET Datatable

I have been using OleDb provider. However, it has problems if you are reading in rows that have numeric values but you want them treated as text. However, you can get around that issue by creating a schema.ini file. Here is my method I used:

// using System.Data;
// using System.Data.OleDb;
// using System.Globalization;
// using System.IO;

static DataTable GetDataTableFromCsv(string path, bool isFirstRowHeader)
    string header = isFirstRowHeader ? "Yes" : "No";

    string pathOnly = Path.GetDirectoryName(path);
    string fileName = Path.GetFileName(path);

    string sql = @"SELECT * FROM [" + fileName + "]";

    using(OleDbConnection connection = new OleDbConnection(
              @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + pathOnly + 
              ";Extended Properties=\"Text;HDR=" + header + "\""))
    using(OleDbCommand command = new OleDbCommand(sql, connection))
    using(OleDbDataAdapter adapter = new OleDbDataAdapter(command))
        DataTable dataTable = new DataTable();
        dataTable.Locale = CultureInfo.CurrentCulture;
        return dataTable;

Assignment inside lambda expression in Python


[o for d in [{}] for o in lst if != "" or d.setdefault("", o) == o]

or using filter and lambda:

flag = {}
filter(lambda o: bool( or flag.setdefault("", o) == o, lst)

Previous Answer

OK, are you stuck on using filter and lambda?

It seems like this would be better served with a dictionary comprehension,

{ : o for o in input}.values()

I think the reason that Python doesn't allow assignment in a lambda is similar to why it doesn't allow assignment in a comprehension and that's got something to do with the fact that these things are evaluated on the C side and thus can give us an increase in speed. At least that's my impression after reading one of Guido's essays.

My guess is this would also go against the philosophy of having one right way of doing any one thing in Python.

Could not load dynamic library 'cudart64_101.dll' on tensorflow CPU-only installation

To install the prerequisites for GPU support in TensorFlow 2.1:

  1. Install your latest GPU drivers.
  2. Install CUDA 10.1.
    • If the CUDA installer reports "you are installing an older driver version", you may wish to choose a custom installation and deselect some components. Indeed, note that software bundled with CUDA including GeForce Experience, PhysX, a Display Driver, and Visual Studio integration are not required by TensorFlow.
    • Also note that TensorFlow requires a specific version of the CUDA Toolkit unless you build from source; for TensorFlow 2.1 and 2.2, this is currently version 10.1.
  3. Install cuDNN.
    1. Download cuDNN v7.6.4 for CUDA 10.1. This will require you to sign up to the NVIDIA Developer Program.
    2. Unzip to a suitable location and add the bin directory to your PATH.
  4. Install tensorflow by pip install tensorflow.
  5. You may need to restart your PC.

The OutputPath property is not set for this project

I had exact same error after adding a new configuration via ConfigurationManager in Visual Studio.

It turned out when the 'Production' configuration was added for the whole solution (and each project) the OutputPath element was not added to the .csproj files.

To fix, I went to the Build tab in project properties, changed OutputPath from \bin\Production\ to \bin\Production (deleted trailing \) and saved changes. This forced creation of the OutputPath element in the .csproj file and the project has built successfully.

Sounds like a glitch to me.

Oracle DateTime in Where Clause?

You could also do:


How to add a second x-axis in matplotlib

I'm taking a cue from the comments in @Dhara's answer, it sounds like you want to set a list of new_tick_locations by a function from the old x-axis to the new x-axis. The tick_function below takes in a numpy array of points, maps them to a new value and formats them:

import numpy as np
import matplotlib.pyplot as plt

fig = plt.figure()
ax1 = fig.add_subplot(111)
ax2 = ax1.twiny()

X = np.linspace(0,1,1000)
Y = np.cos(X*20)

ax1.set_xlabel(r"Original x-axis: $X$")

new_tick_locations = np.array([.2, .5, .9])

def tick_function(X):
    V = 1/(1+X)
    return ["%.3f" % z for z in V]

ax2.set_xlabel(r"Modified x-axis: $1/(1+X)$")

enter image description here

Dealing with "java.lang.OutOfMemoryError: PermGen space" error

Alternatively, you can switch to JRockit which handling permgen differently then sun's jvm. It generally has better performance as well.

How to sign in kubernetes dashboard?



type: NodePort for the Service

And then run this command:

kubectl apply -f kubernetes-dashboard.yaml

Find the exposed port with the command :

kubectl get services -n kube-system

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

Can't clone a github repo on Linux via HTTPS

You can manual disable ssl verfiy, and try again. :)

git config --global http.sslverify false

How to send a Post body in the HttpClient request in Windows Phone 8?

I implemented it in the following way. I wanted a generic MakeRequest method that could call my API and receive content for the body of the request - and also deserialise the response into the desired type. I create a Dictionary<string, string> object to house the content to be submitted, and then set the HttpRequestMessage Content property with it:

Generic method to call the API:

    private static T MakeRequest<T>(string httpMethod, string route, Dictionary<string, string> postParams = null)
        using (var client = new HttpClient())
            HttpRequestMessage requestMessage = new HttpRequestMessage(new HttpMethod(httpMethod), $"{_apiBaseUri}/{route}");

            if (postParams != null)
                requestMessage.Content = new FormUrlEncodedContent(postParams);   // This is where your content gets added to the request body

            HttpResponseMessage response = client.SendAsync(requestMessage).Result;

            string apiResponse = response.Content.ReadAsStringAsync().Result;
                // Attempt to deserialise the reponse to the desired type, otherwise throw an expetion with the response from the api.
                if (apiResponse != "")
                    return JsonConvert.DeserializeObject<T>(apiResponse);
                    throw new Exception();
            catch (Exception ex)
                throw new Exception($"An error ocurred while calling the API. It responded with the following message: {response.StatusCode} {response.ReasonPhrase}");

Call the method:

    public static CardInformation ValidateCard(string cardNumber, string country = "CAN")
        // Here you create your parameters to be added to the request content
        var postParams = new Dictionary<string, string> { { "cardNumber", cardNumber }, { "country", country } };
        // make a POST request to the "cards" endpoint and pass in the parameters
        return MakeRequest<CardInformation>("POST", "cards", postParams);

How do I add records to a DataGridView in VB.Net?

I think you should build a dataset/datatable in code and bind the grid to that.

installing requests module in python 2.7 windows

If you want to install requests directly you can use the "-m" (module) option available to python.

python.exe -m pip install requests

You can do this directly in PowerShell, though you may need to use the full python path (eg. C:\Python27\python.exe) instead of just python.exe.

As mentioned in the comments, if you have added Python to your path you can simply do:

python -m pip install requests

Posting array from form

You're already doing that, as a matter of fact. When the form is submitted, the data is passed through a post array ($_POST). Your process.php is receiving that array and redistributing its values as individual variables.

Eclipse: How do you change the highlight color of the currently selected method/expression?

After running around in the Preferences dialog, the following is the location at which the highlight color for "occurrences" can be changed:

General -> Editors -> Text Editors -> Annotations

Look for Occurences from the Annotation types list.

Then, be sure that Text as highlighted is selected, then choose the desired color.

And, a picture is worth a thousand words...

Preferences dialog

Image showing occurences highlighted in orange.

Java int to String - Integer.toString(i) vs new Integer(i).toString()

Although I like fhucho's recommendation of


The irony is that this method actually calls


Thus, use String.valueOf(i) if you like how it reads and you don't need radix, but also knowing that it is less efficient than Integer.toString(i).

Ruby Hash to array of values

hash  = { :a => ["a", "b", "c"], :b => ["b", "c"] }
hash.values #=> [["a","b","c"],["b","c"]]

How to continue the code on the next line in VBA

To have newline in code you use _


Dim a As Integer
a = 500 _
  + 80 _
  + 90

MsgBox a

Raw_Input() Is Not Defined

For Python 3.x, use input(). For Python 2.x, use raw_input(). Don't forget you can add a prompt string in your input() call to create one less print statement. input("GUESS THAT NUMBER!").

Is it possible to use pip to install a package from a private GitHub repository?

When I was installing from GitHub I was able to use:

pip install git+ssh://[email protected]/<username>/<projectname>.git#egg=<eggname>

But, since I had to run pip as sudo, the SSH keys were not working with GitHub any more, and "git clone" failed on "Permission denied (publickey)". Using git+https allowed me to run the command as sudo, and have GitHub ask me for my user/password.

sudo pip install git+<username>/<projectname>.git#egg=<eggname>

Installing lxml module in python

If you are encountering this issue on an Alpine based image try this :

apk add --update --no-cache g++ gcc libxml2-dev libxslt-dev python-dev libffi-dev openssl-dev make

// pip install -r requirements.txt

How can I get the first two digits of a number?

Comparing the O(n) time solution with the "constant time" O(1) solution provided in other answers goes to show that if the O(n) algorithm is fast enough, n may have to get very large before it is slower than a slow O(1).

The strings version is approx. 60% faster than the "maths" version for numbers of 20 or fewer digits. They become closer only when then number of digits approaches 200 digits

# the "maths" version
import math

def first_n_digits1(num, n):
    return num // 10 ** (int(math.log(num, 10)) - n + 1)

%timeit first_n_digits1(34523452452, 2)
1.21 µs ± 75 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

%timeit first_n_digits1(34523452452, 8)
1.24 µs ± 47.5 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

# 22 digits
%timeit first_n_digits1(3423234239472523452452, 2)
1.33 µs ± 59.4 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

%timeit first_n_digits1(3423234239472523452452, 15)
1.23 µs ± 61.2 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

# 196 digits
%timeit first_n_digits1(3423234239472523409283475908723908723409872390871243908172340987123409871234012089172340987734507612340981344509873123401234670350981234098123140987314509812734091823509871345109871234098172340987125988123452452, 39)
1.86 µs ± 21.8 ns per loop (mean ± std. dev. of 7 runs, 100000 loops each)

# The "string" verions
def first_n_digits2(num, n):
    return int(str(num)[:n])

%timeit first_n_digits2(34523452452, 2)
744 ns ± 28.1 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

%timeit first_n_digits2(34523452452, 8)
768 ns ± 42.7 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

# 22 digits
%timeit first_n_digits2(3423234239472523452452, 2)
767 ns ± 33.6 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

%timeit first_n_digits2(3423234239472523452452, 15)
830 ns ± 55.1 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

# 196 digits
%timeit first_n_digits2(3423234239472523409283475908723908723409872390871243908098712340987123401208917234098773450761234098134450987312340123467035098123409812314098734091823509871345109871234098172340987125988123452452, 39)
1.87 µs ± 140 ns per loop (mean ± std. dev. of 7 runs, 100000 loops each)

How do I use a custom Serializer with Jackson?

I wrote an example for a custom Timestamp.class serialization/deserialization, but you could use it for what ever you want.

When creating the object mapper do something like this:

public class JsonUtils {

    public static ObjectMapper objectMapper = null;

    static {
        objectMapper = new ObjectMapper();
        SimpleModule s = new SimpleModule();
        s.addSerializer(Timestamp.class, new TimestampSerializerTypeHandler());
        s.addDeserializer(Timestamp.class, new TimestampDeserializerTypeHandler());

for example in java ee you could initialize it with this:

import java.time.LocalDateTime;


import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;

public class JacksonConfig implements ContextResolver<ObjectMapper> {

    private final ObjectMapper objectMapper;

    public JacksonConfig() {
        objectMapper = new ObjectMapper();
        SimpleModule s = new SimpleModule();
        s.addSerializer(Timestamp.class, new TimestampSerializerTypeHandler());
        s.addDeserializer(Timestamp.class, new TimestampDeserializerTypeHandler());

    public ObjectMapper getContext(Class<?> type) {
        return objectMapper;

where the serializer should be something like this:

import java.sql.Timestamp;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;

public class TimestampSerializerTypeHandler extends JsonSerializer<Timestamp> {

    public void serialize(Timestamp value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonProcessingException {
        String stringValue = value.toString();
        if(stringValue != null && !stringValue.isEmpty() && !stringValue.equals("null")) {
        } else {

    public Class<Timestamp> handledType() {
        return Timestamp.class;

and deserializer something like this:

import java.sql.Timestamp;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
import com.fasterxml.jackson.databind.SerializerProvider;

public class TimestampDeserializerTypeHandler extends JsonDeserializer<Timestamp> {

    public Timestamp deserialize(JsonParser jp, DeserializationContext ds) throws IOException, JsonProcessingException {
        SqlTimestampConverter s = new SqlTimestampConverter();
        String value = jp.getValueAsString();
        if(value != null && !value.isEmpty() && !value.equals("null"))
            return (Timestamp) s.convert(Timestamp.class, value);
        return null;

    public Class<Timestamp> handledType() {
        return Timestamp.class;

Matching a space in regex

It seems to me like using a REGEX in this case would just be overkill. Why not just just strpos to find the space character. Also, there's nothing special about the space character in regular expressions, you should be able to search for it the same as you would search for any other character. That is, unless you disabled pattern whitespace, which would hardly be necessary in this case.

What's a good, free serial port monitor for reverse-engineering?

I hear a lot of good things about com0com, which is a software port emulator. You can "connect" a physical serial port through it, so that your software uses the (monitored) virtual port, and forwards all traffic to/from a physical port. I haven't used it myself, but I've seen it recommended here on SO a lot.

How do I UPDATE from a SELECT in SQL Server?

In SQL Server 2008 (or better), use MERGE

   USING other_table S 
      ON =
         AND S.tsql = 'cool'
      SET col1 = S.col1, 
          col2 = S.col2;


   USING (
          SELECT id, col1, col2 
            FROM other_table 
           WHERE tsql = 'cool'
         ) S
      ON =
      SET col1 = S.col1, 
          col2 = S.col2;

Limit Get-ChildItem recursion depth

I tried to limit Get-ChildItem recursion depth using Resolve-Path

$PATH = "."
$folder = get-item $PATH 
$FolderFullName = $Folder.FullName
$PATHs = Resolve-Path $FolderFullName\*\*\*\
$Folders = $PATHs | get-item | where {$_.PsIsContainer}

But this works fine :

gci "$PATH\*\*\*\*"

How do I force my .NET application to run as administrator?

You'll want to modify the manifest that gets embedded in the program. This works on Visual Studio 2008 and higher: Project + Add New Item, select "Application Manifest File". Change the <requestedExecutionLevel> element to:

 <requestedExecutionLevel level="requireAdministrator" uiAccess="false" />

The user gets the UAC prompt when they start the program. Use wisely; their patience can wear out quickly.

How to use Switch in SQL Server

Actually i am getting return value from a another sp into @temp and then it @temp =1 then i want to inc the count of @SelectoneCount by 1 and so on. Please let me know what is the correct syntax.

What's wrong with:

IF @Temp = 1 --Or @Temp = 2 also?
    SET @SelectoneCount = @SelectoneCount + 1

(Although this does reek of being procedural code - not usually the best way to use SQL)

How do I uninstall a Windows service if the files do not exist anymore?

From the command prompt, use the Windows "sc.exe" utility. You will run something like this:

sc delete <service-name>

Cross browser JavaScript (not jQuery...) scroll to top animation


var scrollIt = function(time) {
    // time = scroll time in ms
    var start = new Date().getTime(),
        scroll = document.documentElement.scrollTop + document.body.scrollTop,
        timer = setInterval(function() {
            var now = Math.min(time,(new Date().getTime())-start)/time;
                = document.body.scrollTop = (1-time)/start*scroll;
            if( now == 1) clearTimeout(timer);

How can I execute Shell script in Jenkinsfile?

Based on the number of views this question has, it looks like a lot of people are visiting this to see how to set up a job that executes a shell script.

These are the steps to execute a shell script in Jenkins:

  • In the main page of Jenkins select New Item.
  • Enter an item name like "my shell script job" and chose Freestyle project. Press OK.
  • On the configuration page, in the Build block click in the Add build step dropdown and select Execute shell.
  • In the textarea you can either paste a script or indicate how to run an existing script. So you can either say:

    echo "hello, today is $(date)" > /tmp/jenkins_test

    or just

  • Click Save.

Now the newly created job should appear in the main page of Jenkins, together with the other ones. Open it and select Build now to see if it works. Once it has finished pick that specific build from the build history and read the Console output to see if everything happened as desired.

You can get more details in the document Create a Jenkins shell script job in GitHub.

Difference between Parameters.Add(string, object) and Parameters.AddWithValue

When we use CommandObj.Parameter.Add() it takes 2 parameters, the first is procedure parameter and the second is its data type, while .AddWithValue() takes 2 parameters, the first is procedure parameter and the second is the data variable


for .AddWithValue


where ID is the parameter of stored procedure which data type is Int

Convert JS Object to form data

I might be a little late to the party but this is what I've created to convert a singular object to FormData.

function formData(formData, filesIgnore = []) {
  let data = new FormData();

  let files = filesIgnore;

  Object.entries(formData).forEach(([key, value]) => {
    if (typeof value === 'object' && !files.includes(key)) {
      data.append(key, JSON.stringify(value) || null);
    } else if (files.includes(key)) {
      data.append(key, value[0] || null);
    } else {
      data.append(key, value || null);

  return data;

How does it work? It will convert and return all properties expect File objects that you've set in the ignore list (2nd argument. If anyone could tell me a better way to determine this that would help!) into a json string using JSON.stringify. Then on your server you'll just need to convert it back into a JSON object.


let form = {
  first_name: 'John',
  last_name: 'Doe',
  details: {
    phone_number: 1234 5678 910,
    address: '123 Some Street',
  profile_picture: [object FileList] // set by your form file input. Currently only support 1 file per property.

function submit() {
  let data = formData(form, ['profile_picture']);'/url', data).then(res => {
    console.log('object uploaded');

I am still kinda new to Http requests and JavaScript so any feedback would be highly appreciated!

How to get child element by ID in JavaScript?


function looking for all dom objects inside the selected DOM. i.e.

<div id="mainDiv">
    <p>Paragraph 1</p>
    <p>Paragraph 2</p>
    <div id="innerDiv">
         <a href="#">link</a>
         <p>Paragraph 3</p>

here if you write;


you will get tree p elements together. On the other side,


Function searching in the just children DOMs of the selected DOM object. So, by this code you will get just paragraph 1 and paragraph 2. It is so beneficial to prevent browser doing unnecessary progress.

How to find the default JMX port number?

Now I need to connect that application from my local computer, but I don't know the JMX port number of the remote computer. Where can I find it? Or, must I restart that application with some VM parameters to specify the port number?

By default JMX does not publish on a port unless you specify the arguments from this page: How to activate JMX... # no longer required for JDK6 # careful with security implications # careful with security implications

If you are running you should be able to access any of those system properties to see if they have been set:

if (System.getProperty("") == null) {
    System.out.println("JMX remote is disabled");
} else [
    String portString = System.getProperty("");
    if (portString != null) {
        System.out.println("JMX running on port "
            + Integer.parseInt(portString));

Depending on how the server is connected, you might also have to specify the following parameter. As part of the initial JMX connection, jconsole connects up to the RMI port to determine which port the JMX server is running on. When you initially start up a JMX enabled application, it looks its own hostname to determine what address to return in that initial RMI transaction. If your hostname is not in /etc/hosts or if it is set to an incorrect interface address then you can override it with the following:

-Djava.rmi.server.hostname=<IP address>

As an aside, my SimpleJMX package allows you to define both the JMX server and the RMI port or set them both to the same port. The above port defined with is actually the RMI port. This tells the client what port the JMX server is running on.

Parsing JSON array into java.util.List with Gson

Definitely the easiest way to do that is using Gson's default parsing function fromJson().

There is an implementation of this function suitable for when you need to deserialize into any ParameterizedType (e.g., any List), which is fromJson(JsonElement json, Type typeOfT).

In your case, you just need to get the Type of a List<String> and then parse the JSON array into that Type, like this:

import java.lang.reflect.Type;

JsonElement yourJson = mapping.get("servers");
Type listType = new TypeToken<List<String>>() {}.getType();

List<String> yourList = new Gson().fromJson(yourJson, listType);

In your case yourJson is a JsonElement, but it could also be a String, any Reader or a JsonReader.

You may want to take a look at Gson API documentation.

Building a complete online payment gateway like Paypal

What you're talking about is becoming a payment service provider. I have been there and done that. It was a lot easier about 10 years ago than it is now, but if you have a phenomenal amount of time, money and patience available, it is still possible.

You will need to contact an acquiring bank. You didnt say what region of the world you are in, but by this I dont mean a local bank branch. Each major bank will generally have a separate card acquiring arm. So here in the UK we have (eg) Natwest bank, which uses Streamline (or Worldpay) as its acquiring arm. In total even though we have scores of major banks, they all end up using one of five or so card acquirers.

Happily, all UK card acquirers use a standard protocol for communication of authorisation requests, and end of day settlement. You will find minor quirks where some acquiring banks support some features and have slightly different syntax, but the differences are fairly minor. The UK standards are published by the Association for Payment Clearing Services (APACS) (which is now known as the UKPA). The standards are still commonly referred to as APACS 30 (authorization) and APACS 29 (settlement), but are now formally known as APACS 70 (books 1 through 7).

Although the APACS standard is widely supported across the UK (Amex and Discover accept messages in this format too) it is not used in other countries - each country has it's own - for example: Carte Bancaire in France, CartaSi in Italy, Sistema 4B in Spain, Dankort in Denmark etc. An effort is under way to unify the protocols across Europe - see

Communicating with the acquiring bank can be done a number of ways. Again though, it will depend on your region. In the UK (and most of Europe) we have one communications gateway that provides connectivity to all the major acquirers, they are called TNS and there are dozens of ways of communicating through them to the acquiring bank, from dialup 9600 baud modems, ISDN, HTTPS, VPN or dedicated line. Ultimately the authorisation request will be converted to X25 protocol, which is the protocol used by these acquiring banks when communicating with each other.

In summary then: it all depends on your region.

  • Contact a major bank and try to get through to their card acquiring arm.
  • Explain that you're setting up as a payment service provider, and request details on comms format for authorization requests and end of day settlement files
  • Set up a test merchant account and develop auth/settlement software and go through the accreditation process. Most acquirers help you through this process for free, but when you want to register as an accredited PSP some will request a fee.
  • you will need to comply with some regulations too, for example you may need to register as a payment institution

Once you are registered and accredited you'll then be able to accept customers and set up merchant accounts on behalf of the bank/s you're accredited against (bearing in mind that each acquirer will generally support multiple banks). Rinse and repeat with other acquirers as you see necessary.

Beyond that you have lots of other issues, mainly dealing with PCI-DSS. Thats a whole other topic and there are already some q&a's on this site regarding that. Like I say, its a phenomenal undertaking - most likely a multi-year project even for a reasonably sized team, but its certainly possible.

Update statement with inner join on Oracle

update table1  a 
   set a.col1='Y' 
 where exists(select 1 
                from table2 b
               where a.col1=b.col1 
                 and a.col2=b.col2

How to check the installed version of React-Native

To see what version you have on your Mac(Window also can run that code.), run react-native -v and you should get something like this:

enter image description here

If you want to know what version your project is running, look in /node_modules/react-native/package.json and look for the version key:

enter image description here

Get statistics for each group (such as count, mean, etc) using pandas GroupBy?

Create a group object and call methods like below example:

grp = df.groupby(['col1',  'col2',  'col3']) 


'mat-form-field' is not a known element - Angular 5 & Material2

You're trying to use the MatFormFieldComponent in SearchComponent but you're not importing the MatFormFieldModule (which exports MatFormFieldComponent); you only export it.

Your MaterialModule needs to import it.

  imports: [
  exports: [
  declarations: [
export class MaterialModule { }

Scrolling to element using webdriver?

You are trying to run Java code with Python. In Python/Selenium, the org.openqa.selenium.interactions.Actions are reflected in ActionChains class:

from selenium.webdriver.common.action_chains import ActionChains

element = driver.find_element_by_id("my-id")

actions = ActionChains(driver)

Or, you can also "scroll into view" via scrollIntoView():

driver.execute_script("arguments[0].scrollIntoView();", element)

If you are interested in the differences:

Most efficient way to map function over numpy array

I believe in newer version( I use 1.13) of numpy you can simply call the function by passing the numpy array to the fuction that you wrote for scalar type, it will automatically apply the function call to each element over the numpy array and return you another numpy array

>>> import numpy as np
>>> squarer = lambda t: t ** 2
>>> x = np.array([1, 2, 3, 4, 5])
>>> squarer(x)
array([ 1,  4,  9, 16, 25])

How to make a div fill a remaining horizontal space?

I had a similar issue and came up with the following which worked well


.top {
width: auto;
height: 100px;
background-color: black;
border: solid 2px purple;
overflow: hidden;
.left {
padding: 10px;
border: solid 2px black;
.right {
width: auto;
padding: 10px;
border: solid 2px orange;
overflow: hidden;
.content {
margin: auto;
width: 300px;
min-height: 300px;
padding: 10px;
border: dotted 2px gray;


<div class=top>top </div>
    <div class="left">left </div>
    <div class="right">
        <div class="content">right </div>

This method won't wrap when the window is shrunk but will auto expand the 'content' area. It will keep a static width for the site menu (left).

And for auto expanding content box and left vertical box(site menu) demo:

get the selected index value of <select> tag in php

Your form is valid. Only thing that comes to my mind is, after seeing your full html, is that you're passing your "default" value (which is not set!) instead of selecting something. Try as suggested by @Vina in the comment, i.e. giving it a selected option, or writing a default value

<select name="gender">
<option value="default">Select </option>    
<option value="male">   Male   </option>
<option value="female"> Female </option>


<select name="gender">
<option value="male" selected="selected">   Male   </option>
<option value="female"> Female </option>

When you get your $_POST vars, check for them being set; you can assign a default value, or just an empty string in case they're not there.

Most important thing, AVOID SQL INJECTIONS:

$fname   = isset($_POST["fname"]) ? mysql_real_escape_string($_POST['fname']) : '';
$lname   = isset($_POST['lname']) ? mysql_real_escape_string($_POST['lname']) : '';
$email   = isset($_POST['email']) ? mysql_real_escape_string($_POST['email']) : '';
you might also want to validate e-mail:
if($mail = filter_var($_POST['email'], FILTER_VALIDATE_EMAIL))
  $email = mysql_real_escape_string($_POST['email']);
  //die ('invalid email address');
  // or whatever, a default value? $email = '';
$paswod  = isset($_POST["paswod"]) ? mysql_real_escape_string($_POST['paswod']) : '';
$gender  = isset($_POST['gender']) ? mysql_real_escape_string($_POST['gender']) : '';

$query = mysql_query("SELECT Email FROM users WHERE Email = '".$email."')";
if(mysql_num_rows($query)> 0)
  echo 'userid is already there';
 $sql = "INSERT INTO users (FirstName, LastName, Email, Password, Gender)
         VALUES ('".$fname."','".$lname."','".$email."','".paswod."','".$gender."')";
$res = mysql_query($sql) or die('Error:'.mysql_error());
echo 'created';

PHP foreach change original array values

Use &:

foreach($arr as &$value) {
    $value = $newVal;

& passes a value of the array as a reference and does not create a new instance of the variable. Thus if you change the reference the original value will change.

PHP documentation for Passing by Reference

Edit 2018

This answer seems to be favored by a lot of people on the internet, which is why I decided to add more information and words of caution.
While pass by reference in foreach (or functions) is a clean and short solution, for many beginners this might be a dangerous pitfall.

  1. Loops in PHP don't have their own scope. - @Mark Amery

    This could be a serious problem when the variables are being reused in the same scope. Another SO question nicely illustrates why that might be a problem.

  2. As foreach relies on the internal array pointer in PHP 5, changing it within the loop may lead to unexpected behavior. - PHP docs for foreach.

    Unsetting a record or changing the hash value (the key) during the iteration on the same loop could lead to potentially unexpected behaviors in PHP < 7. The issue gets even more complicated when the array itself is a reference.

  3. Foreach performance.
    In general, PHP prefers pass by value due to the copy-on-write feature. It means that internally PHP will not create duplicate data unless the copy of it needs to be changed. It is debatable whether pass by reference in foreach would offer a performance improvement. As it is always the case, you need to test your specific scenario and determine which option uses less memory and CPU time. For more information see the SO post linked below by NikiC.

  4. Code readability.
    Creating references in PHP is something that quickly gets out of hand. If you are a novice and don't have full control of what you are doing, it is best to stay away from references. For more information about & operator take a look at this guide: Reference — What does this symbol mean in PHP?
    For those who want to learn more about this part of PHP language: PHP References Explained

A very nice technical explanation by @NikiC of the internal logic of PHP foreach loops:
How does PHP 'foreach' actually work?

Failed to resolve:

28.0.0 is the final version of support libraries. Android has migrated to AndroidX. To use the latest android libraries, Migrating to AndroidX

Edit: Versions 28.0.0-rc02 and 28.0.0 are now available.

I don't see any 28.0 version on Google Maven. Only 28.0.0-alpha1 and 28.0.0-alpha3. Just change it to either of those or how it was previously, i.e., with .+ which just means any version under 28 major release.

For an alpha appcompat release 28.+ makes more sense.

android:drawableLeft margin and/or padding

TextView has an android:drawablePadding property which should do the trick:


The padding between the drawables and the text.

Must be a dimension value, which is a floating point number appended with a unit such as "14.5sp". Available units are: px (pixels), dp (density-independent pixels), sp (scaled pixels based on preferred font size), in (inches), mm (millimeters).

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

This corresponds to the global attribute resource symbol drawablePadding.

Insert all data of a datagridview to database at once

for (int i = 0; i < dataGridView2.Rows.Count; i++)
SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=ID_Proof;Integrated Security=True");
                        SqlCommand cmd = new SqlCommand("INSERT INTO Restaurant (Customer_Name,Quantity,Price,Category,Subcategory,Item,Room_No,Tax,Service_Charge,Service_Tax,Order_Time) values (@customer,@quantity,@price,@category,@subcategory,@item,@roomno,@tax,@servicecharge,@sertax,@ordertime)", con);
                        MessageBox.Show("Added successfully!");

What is the difference between visibility:hidden and display:none?

There are a lot of detailed answers here, but I thought I should add this to address accessibility since there are implications.

display: none; and visibility: hidden; may not be read by all screen reader software. Keep in mind what visually-impaired users will experience.

The question also asks about synonyms. text-indent: -9999px; is one other that is roughly equivalent. The important difference with text-indent is that it will often be read by screen readers. It can be a bit of a bad experience as users can still tab to the link.

For accessibility, what I see used today is a combination of styles to hide an element while being visible to screen readers.

  clip: rect(1px, 1px, 1px, 1px);
  clip-path: inset(50%);
  height: 1px;
  width: 1px;
  margin: -1px;
  overflow: hidden;
  padding: 0;
  position: absolute;

A great practice is to create a "Skip to content" link to the anchor of the main body of content. Visually-impaired users probably don't want to listen to your full navigation tree on every single page. Make the link visually hidden. Users can just hit tab to access the link.

For more on accessibility and hidden content, see:

How do I check if string contains substring?

you can define an extension method and use it later.

String.prototype.contains = function(it) 
   return this.indexOf(it) != -1; 

so that you can use in your page anywhere like:

var str="hello how are you";

which returns true.

Refer below post for more extension helper methods. Javascript helper methods

How to Deserialize JSON data?

You can deserialize this really easily. The data's structure in C# is just List<string[]> so you could just do;

  List<string[]> data = JsonConvert.DeserializeObject<List<string[]>>(jsonString);

The above code is assuming you're using json.NET.

EDIT: Note the json is technically an array of string arrays. I prefer to use List<string[]> for my own declaration because it's imo more intuitive. It won't cause any problems for json.NET, if you want it to be an array of string arrays then you need to change the type to (I think) string[][] but there are some funny little gotcha's with jagged and 2D arrays in C# that I don't really know about so I just don't bother dealing with it here.

Angularjs ng-model doesn't work inside ng-if

We had this in many other cases, what we decided internally is to always have a wrapper for the controller/directive so that we don't need to think about it. Here is you example with our wrapper.

<script src=""></script>

    function main($scope) {
        $scope.thisScope = $scope;
        $scope.testa = false;
        $scope.testb = false;
        $scope.testc = false;
        $scope.testd = false;

<div ng-app >
    <div ng-controller="main">

        Test A: {{testa}}<br />
        Test B: {{testb}}<br />
        Test C: {{testc}}<br />
        Test D: {{testd}}<br />

            testa (without ng-if): <input type="checkbox" ng-model="thisScope.testa" />
        <div ng-if="!testa">
            testb (with ng-if): <input type="checkbox" ng-model="thisScope.testb" />
        <div ng-show="!testa">
            testc (with ng-show): <input type="checkbox" ng-model="thisScope.testc" />
        <div ng-hide="testa">
            testd (with ng-hide): <input type="checkbox" ng-model="thisScope.testd" />


Hopes this helps, Yishay not found error

here is your answer

String userName = "xxxx";
    String password = "xxxx";
    String url = ";databaseName=asdfzxcvqwer;integratedSecurity=true";

    try {
            connection = DriverManager.getConnection(url, userName, password); 

  } catch (Exception e)

Failed to connect to, reason: errno:111 Connection refused

Do this:

sudo rm /var/lib/mongodb/mongod.lock
sudo service mongod restart

If you are on Ubuntu 16.04 which you can figure out by runnign this:

lsb_release -a

You need to Create a new file at /lib/systemd/system/mongod.service with the following contents:

Description=High-performance, schema-free document-oriented database

ExecStart=/usr/bin/mongod --quiet --config /etc/mongod.conf


Spring,Request method 'POST' not supported

I had csrf enabled in my sprint security xml file, so I just added one line in the form:

<input type="hidden" name="${_csrf.parameterName}" value="${_csrf.token}" /> 

This way I was able to submit the form having the model attribute.

How to trigger a phone call when clicking a link in a web page on mobile phone

The proper URL scheme is tel:[number] so you would do

<a href="tel:5551234567"><img src="callme.jpg" /></a>

Run certain code every n seconds

Save yourself a schizophrenic episode and use the Advanced Python scheduler:

The code is so simple:

from apscheduler.scheduler import Scheduler

sched = Scheduler()

def some_job():
    print "Every 10 seconds"

sched.add_interval_job(some_job, seconds = 10)


Difference between ${} and $() in Bash

  1. $() means: "first evaluate this, and then evaluate the rest of the line".

    Ex :

    echo $(pwd)/myFile.txt

    will be interpreted as

    echo /my/path/myFile.txt

    On the other hand ${} expands a variable.


    echo ${MY_VAR}/myFile.txt

    will be interpreted as

    echo toto/myFile.txt
  2. Why can't I use it as bash$ while ((i=0;i<10;i++)); do echo $i; done

    I'm afraid the answer is just that the bash syntax for while just isn't the same as the syntax for for.

Remove part of string after "."

If the string should be of fixed length, then substr from base R can be used. But, we can get the position of the . with regexpr and use that in substr

substr(a, 1, regexpr("\\.", a)-1)
#[1] "NM_020506"    "NM_020519"    "NM_001030297" "NM_010281"    "NM_011419"    "NM_053155"   

how to set background image in submit button?

i do it like this cover button and the middle image that

<button><img src="foldername/imagename" width="30px" height= "30px"></button>

Use PHP composer to clone git repo

At the time of writing in 2013, this was one way to do it. Composer has added support for better ways: See @igorw 's answer


Git, Mercurial and SVN is supported by Composer.




If you have a repository you can write to: Add a composer.json file, or fix the existing one, and DON'T use the solution below.

Go to @igorw 's answer


This will override everything that Composer may be able to read from the original repository's composer.json, including the dependencies of the package and the autoloading.

Using the package type will transfer the burden of correctly defining everything onto you. The easier way is to have a composer.json file in the repository, and just use it.

This solution really only is for the rare cases where you have an abandoned ZIP download that you cannot alter, or a repository you can only read, but it isn't maintained anymore.

"repositories": [
        "package": {
          "name": "l3pp4rd/doctrine-extensions",
          "source": {
              "url": "",
              "type": "git",
"require": {
    "l3pp4rd/doctrine-extensions": "master"

Format LocalDateTime with Timezone in Java8

The prefix "Local" in JSR-310 (aka java.time-package in Java-8) does not indicate that there is a timezone information in internal state of that class (here: LocalDateTime). Despite the often misleading name such classes like LocalDateTime or LocalTime have NO timezone information or offset.

You tried to format such a temporal type (which does not contain any offset) with offset information (indicated by pattern symbol Z). So the formatter tries to access an unavailable information and has to throw the exception you observed.


Use a type which has such an offset or timezone information. In JSR-310 this is either OffsetDateTime (which contains an offset but not a timezone including DST-rules) or ZonedDateTime. You can watch out all supported fields of such a type by look-up on the method isSupported(TemporalField).. The field OffsetSeconds is supported in OffsetDateTime and ZonedDateTime, but not in LocalDateTime.

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd HH:mm:ss.SSSSSS Z");
String s =;

Font Awesome 5 font-family issue

the solution is call it like normal font:

@font-face {
font-family: "Font Awesome 5 Free-Regular-400";
src: url(../fonts/Font%20Awesome%205%20Free-Regular-400.otf) format("opentype");}

exec failed because the name not a valid identifier?

As was in my case if your sql is generated by concatenating or uses converts then sql at execute need to be prefixed with letter N as below


Exec N'Select bla..' 

the N defines string literal is unicode.

Refresh Page C# ASP.NET

You shouldn't use:

Page.Response.Redirect(Page.Request.Url.ToString(), true);

because this might cause a runtime error.

A better approach is:

Page.Response.Redirect(Page.Request.Url.ToString(), false);

C# find biggest number

If your numbers are a, b and c then:

    int a = 1;
    int b = 2;
    int c = 3;

    int d =  a > b ? a : b;
    return c > d ? c : d;

This could turn into one of those "how many different ways can we do this" type questions!

Extract and delete all .gz in a directory- Linux

Extract all gz files in current directory and its subdirectories:

 find . -name "*.gz" | xargs gunzip 

Fit cell width to content

I'm not sure if I understand your question, but I'll take a stab at it:

td {
    border: 1px solid #000;

tr td:last-child {
    width: 1%;
    white-space: nowrap;
<table style="width: 100%;">
        <td class="block">this should stretch</td>
        <td class="block">this should stretch</td>
        <td class="block">this should be the content width</td>

Get selected row item in DataGrid WPF

You can also:

DataRowView row = dataGrid.SelectedItem as DataRowView;

Objective-C: Reading a file line by line

Using category or extension to make our life a bit easier.

extension String {

    func lines() -> [String] {
        var lines = [String]()
        self.enumerateLines { (line, stop) -> () in
        return lines


// then
for line in string.lines() {
    // do the right thing

Partial Dependency (Databases)

If there is a Relation R(ABC)

|A | B | C |
|a | 1 | x |
|b | 1 | x |
|c | 1 | x |
|d | 2 | y |
|e | 2 | y |
|f | 3 | z |
|g | 3 | z |
F1: A --> B 
F2: B --> C

The Primary Key and Candidate Key is: A

As the closure of A+ = {ABC} or R --- So only attribute A is sufficient to find Relation R.

DEF-1: From Some Definitions (unknown source) - A partial dependency is a dependency when prime attribute (i.e., an attribute that is a part(or proper subset) of Candidate Key) determines non-prime attribute (i.e., an attribute that is not the part (or subset) of Candidate Key).

Hence, A is a prime(P) attribute and B, C are non-prime(NP) attributes.

So, from the above DEF-1,

CONSIDERATION-1:: F1: A --> B (P determines NP) --- It must be Partial Dependency.

CONSIDERATION-2:: F2: B --> C (NP determines NP) --- Transitive Dependency.

What I understood from @philipxy answer ( is...

CONSIDERATION-1:: F1: A --> B; Should be fully functional dependency because B is completely dependent on A and If we Remove A then there is no proper subset of (for complete clarification consider L.H.S. as X NOT BY SINGLE ATTRIBUTE) that could determine B.

For Example: If I consider F1: X --> Y where X = {A} and Y = {B} then if we remove A from X; i.e., X - {A} = {}; and an empty set is not considered generally (or not at all) to define functional dependency. So, there is no proper subset of X that could hold the dependency F1: X --> Y; Hence, it is fully functional dependency.

F1: A --> B If we remove A then there is no attribute that could hold functional dependency F1. Hence, F1 is fully functional dependency not partial dependency.

If F1 were, F1: AC --> B;
and F2 were, F2: C --> B; 
then on the removal of A;
C --> B that means B is still dependent on C; 
we can say F1 is partial dependecy.

So, @philipxy answer contradicts DEF-1 and CONSIDERATION-1 that is true and crystal clear.

Hence, F1: A --> B is Fully Functional Dependency not partial dependency.

I have considered X to show left hand side of functional dependency because single attribute couldn't have a proper subset of attributes. Here, I am considering X as a set of attributes and in current scenario X is {A}

-- For the source of DEF-1, please search on google you may be able to hit similar definitions. (Consider that DEF-1 is incorrect or do not work in the above-mentioned example).

annotation to make a private method public only for test classes

You can't do this, since then how could you even compile your tests? The compiler won't take the annotation into account.

There are two general approaches to this

The first is to use reflection to access the methods anyway

The second is to use package-private instead of private, then have your tests in the same package (but in a different module). They will essentially be private to other code, but your tests will still be able to access them.

Of course, if you do black-box testing, you shouldn't be accessing the private members anyway.

How do I open the "front camera" on the Android platform?

All older answers' methods are deprecated by Google (supposedly because of troubles like this), since API 21 you need to use the Camera 2 API:

This class was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications.

In the newer API you have almost complete power over the Android device camera and documentation explicitly advice to

String[] getCameraIdList()

and then use obtained CameraId to open the camera:

void openCamera(String cameraId, CameraDevice.StateCallback callback, Handler handler)

99% of the frontal cameras have id = "1", and the back camera id = "0" according to this:

Non-removable cameras use integers starting at 0 for their identifiers, while removable cameras have a unique identifier for each individual device, even if they are the same model.

However, this means if device situation is rare like just 1-frontal -camera tablet you need to count how many embedded cameras you have, and place the order of the camera by its importance ("0"). So CAMERA_FACING_FRONT == 1 CAMERA_FACING_BACK == 0, which implies that the back camera is more important than frontal.

I don't know about a uniform method to identify the frontal camera on all Android devices. Simply said, the Android OS inside the device can't really find out which camera is exactly where for some reasons: maybe the only camera hardcoded id is an integer representing its importance or maybe on some devices whichever side you turn will be .. "back".


Explicit Examples:

For the older API (it is not recommended, because it will not work on modern phones newer Android version and transfer is a pain-in-the-arse). Just use the same Integer CameraID (1) to open frontal camera like in this answer:

cam =;

If you trust OpenCV to do the camera part:



use the following for the frontal camera:


Parsing JSON object in PHP using json_decode

This appears to work:

$url = ',austria&format=json&num_of_days=5&key=8f2d1ea151085304102710%22';
$content = file_get_contents($url);
$json = json_decode($content, true);

foreach($json['data']['weather'] as $item) {
    print $item['date'];
    print ' - ';
    print $item['weatherDesc'][0]['value'];
    print ' - ';
    print '<img src="' . $item['weatherIconUrl'][0]['value'] . '" border="0" alt="" />';
    print '<br>';

If you set the second parameter of json_decode to true, you get an array, so you cant use the -> syntax. I would also suggest you install the JSONview Firefox extension, so you can view generated json documents in a nice formatted tree view similiar to how Firefox displays XML structures. This makes things a lot easier.

How do I display image in Alert/confirm box in Javascript?

Use jQuery dialog to show image, try this code

     <div id="divid">



first you have to include jQuery UI at your Page.

Working fiddle

How to install Selenium WebDriver on Mac OS

Mac already has Python and a package manager called easy_install, so open Terminal and type

sudo easy_install selenium

Batch / Find And Edit Lines in TXT file

You can always use "FAR" = "Find and Replace". It's written under java, so it works where Java works (pretty much everywhere). Works with directories and subdirectories, searches and replaces within files, also can renames them. Also can rename bulk files.Licence = free, for both individuals or comapnies. Very fast and maintained by the developer. Find it here:

Also you can use GrepWin. Works pretty much the same. You can find it here:

Select2() is not a function

I used the jQuery slim version and got this error. By using the normal jQuery version the issue got resolved.

Catching multiple exception types in one catch block

Besides fall-through, it's also possible to step over by using goto. It's very useful if you want to see the world burn.


class A_Error extends Exception {}
class B_Error extends Exception {}
class C_Error extends Exception {}

try {
    throw new A_Error();
catch (A_Error $e) { goto abc; }
catch (B_Error $e) { goto abc; }
catch (C_Error $e) {
    echo "Gotta Catch 'Em All\n";

Java way to check if a string is palindrome

Using reverse is overkill because you don't need to generate an extra string, you just need to query the existing one. The following example checks the first and last characters are the same, and then walks further inside the string checking the results each time. It returns as soon as s is not a palindrome.

The problem with the reverse approach is that it does all the work up front. It performs an expensive action on a string, then checks character by character until the strings are not equal and only then returns false if it is not a palindrome. If you are just comparing small strings all the time then this is fine, but if you want to defend yourself against bigger input then you should consider this algorithm.

boolean isPalindrome(String s) {
  int n = s.length();
  for (int i = 0; i < (n/2); ++i) {
     if (s.charAt(i) != s.charAt(n - i - 1)) {
         return false;

  return true;

SQL How to remove duplicates within select query?

You mention that there are date duplicates, but it appears they're quite unique down to the precision of seconds.

Can you clarify what precision of date you start considering dates duplicate - day, hour, minute?

In any case, you'll probably want to floor your datetime field. You didn't indicate which field is preferred when removing duplicates, so this query will prefer the last name in alphabetical order.

 SELECT MAX(owner_name), 
        --floored to the second
        dateadd(second,datediff(second,'2000-01-01',start_date),'2000-01-01') AS StartDate
 From   MyTable
 GROUP BY dateadd(second,datediff(second,'2000-01-01',start_date),'2000-01-01')

Example use of "continue" statement in Python?

Let's say we want to print all numbers which are not multiples of 3 and 5

for x in range(0, 101):
    if x % 3 ==0 or x % 5 == 0:
        #no more code is executed, we go to the next number 
    print x

Must JDBC Resultsets and Statements be closed separately although the Connection is closed afterwards?

Some convenience functions:

public static void silentCloseResultSets(Statement st) {
    try {
        while (!(!st.getMoreResults() && (st.getUpdateCount() == -1))) {}
    } catch (SQLException ignore) {}
public static void silentCloseResultSets(Statement ...statements) {
    for (Statement st: statements) silentCloseResultSets(st);

Print Currency Number Format in PHP

PHP has a function called money_format for doing this. Read about this here.

PHP remove special character from string

See example.

 * nv_get_plaintext()
 * @param mixed $string
 * @return
function nv_get_plaintext( $string, $keep_image = false, $keep_link = false )
    // Get image tags
    if( $keep_image )
        if( preg_match_all( "/\<img[^\>]*src=\"([^\"]*)\"[^\>]*\>/is", $string, $match ) )
            foreach( $match[0] as $key => $_m )
                $textimg = '';
                if( strpos( $match[1][$key], 'data:image/png;base64' ) === false )
                    $textimg = " " . $match[1][$key];
                if( preg_match_all( "/\<img[^\>]*alt=\"([^\"]+)\"[^\>]*\>/is", $_m, $m_alt ) )
                    $textimg .= " " . $m_alt[1][0];
                $string = str_replace( $_m, $textimg, $string );

    // Get link tags
    if( $keep_link )
        if( preg_match_all( "/\<a[^\>]*href=\"([^\"]+)\"[^\>]*\>(.*)\<\/a\>/isU", $string, $match ) )
            foreach( $match[0] as $key => $_m )
                $string = str_replace( $_m, $match[1][$key] . " " . $match[2][$key], $string );

    $string = str_replace( ' ', ' ', strip_tags( $string ) );
    return preg_replace( '/[ ]+/', ' ', $string );

Using OR in SQLAlchemy

SQLAlchemy overloads the bitwise operators &, | and ~ so instead of the ugly and hard-to-read prefix syntax with or_() and and_() (like in Bastien's answer) you can use these operators:

.filter((AddressBook.lastname == 'bulger') | (AddressBook.firstname == 'whitey'))

Note that the parentheses are not optional due to the precedence of the bitwise operators.

So your whole query could look like this:

addr = session.query(AddressBook) \
    .filter( == "boston") \
    .filter((AddressBook.lastname == 'bulger') | (AddressBook.firstname == 'whitey'))

pyplot scatter plot marker size

It is the area of the marker. I mean if you have s1 = 1000 and then s2 = 4000, the relation between the radius of each circle is: r_s2 = 2 * r_s1. See the following plot:

plt.scatter(2, 1, s=4000, c='r')
plt.scatter(2, 1, s=1000 ,c='b')
plt.scatter(2, 1, s=10, c='g')

enter image description here

I had the same doubt when I saw the post, so I did this example then I used a ruler on the screen to measure the radii.

Initialize array of strings

There is no right way, but you can initialize an array of literals:

char **values = (char *[]){"a", "b", "c"};

or you can allocate each and initialize it:

char **values = malloc(sizeof(char*) * s);
    values[i] = malloc(sizeof(char) * l);
    values[i] = "hello";

How to uninstall Ruby from /usr/local?

Edit: As suggested in comments. This solution is for Linux OS. That too if you have installed ruby manually from package-manager.

If you want to have multiple ruby versions, better to have RVM. In that case you don't need to remove ruby older version.

Still if want to remove then follow the steps below:

First you should find where Ruby is:

whereis ruby

will list all the places where it exists on your system, then you can remove all them explicitly. Or you can use something like this:

rm -rf /usr/local/lib/ruby
rm -rf /usr/lib/ruby
rm -f /usr/local/bin/ruby
rm -f /usr/bin/ruby
rm -f /usr/local/bin/irb
rm -f /usr/bin/irb
rm -f /usr/local/bin/gem
rm -f /usr/bin/gem

How do I get the App version and build number using Swift?

Xcode 9.4.1 Swift 4.1

Note the use of localizedInfoDictionary to pick up the right language version of the bundle display name.

var displayName: String?
var version: String?
var build: String?

override func viewDidLoad() {

    // Get display name, version and build

    if let displayName = Bundle.main.localizedInfoDictionary?["CFBundleDisplayName"] as? String {
        self.displayName = displayName
    if let version = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String {
        self.version = version
    if let build = Bundle.main.infoDictionary?["CFBundleVersion"] as? String { = build

How Stuff and 'For Xml Path' work in SQL Server?

This article covers various ways of concatenating strings in SQL, including an improved version of your code which doesn't XML-encode the concatenated values.

        SELECT ',' + name
        FROM temp1 As T2
        -- You only want to combine rows for a single ID here:
        WHERE T2.ID = T1.ID
        ORDER BY name
        FOR XML PATH (''), TYPE
    ).value('.', 'varchar(max)')
, 1, 1, '')
FROM temp1 As T1

To understand what's happening, start with the inner query:

SELECT ',' + name
FROM temp1 As T2
WHERE T2.ID = 42 -- Pick a random ID from the table

Because you're specifying FOR XML, you'll get a single row containing an XML fragment representing all of the rows.

Because you haven't specified a column alias for the first column, each row would be wrapped in an XML element with the name specified in brackets after the FOR XML PATH. For example, if you had FOR XML PATH ('X'), you'd get an XML document that looked like:


But, since you haven't specified an element name, you just get a list of values:


The .value('.', 'varchar(max)') simply retrieves the value from the resulting XML fragment, without XML-encoding any "special" characters. You now have a string that looks like:


The STUFF function then removes the leading comma, giving you a final result that looks like:


It looks quite confusing at first glance, but it does tend to perform quite well compared to some of the other options.

Conversion of a varchar data type to a datetime data type resulted in an out-of-range value in SQL query

I struggled with the same problem. I have stored dates in SQL Server with format 'YYYY-MM-DD HH:NN:SS' for about 20 years, but today that was not able anymore from a C# solution using OleDbCommand and a UPDATE query.

The solution to my problem was to remove the hyphen - in the format, so the resulting formatting is now 'YYYYMMDD HH:MM:SS'. I have no idea why my previous formatting not works anymore, but I suspect there is something to do with some Windows updates for ADO.

Xcode process launch failed: Security

Hey so the accepted answer works, except if you need to debug the initial launch of the app. However I think that answer is more of a work around, and not an actual solution. From my understanding this message occurs when you have some weirdness in your provisioning profile / cert setup so make extra sure everything is in tip-top shape in that dept. before ramming your head against the wall repeatedly.

What worked for me was as follows from the apple docs:

Provisioning Profiles Known Issue If you have upgraded to the GM seed from other betas you may see your apps crashing due to provisioning profile issues.


  1. Connect the device via USB to your Mac

  2. Launch Xcode Choose Window ->Devices

  3. Right click on the device in left column, choose "Show Provisioning Profiles"

  4. Click on the provisioning profile in question

  5. Press the "-" button Continue to removing all affected profiles.

  6. Re-install the app

Make sure you right click on the image of the device not the name of the device or you won't see the provisioning profiles option. I restored my new phone from an old backup and there was a lot of cruft hanging around, i also had 2 different dev. certs active (not sure why) but i deleted one, made a new profile got rid of all the profiles on device and it worked.

Hope this helps someone else.

Search an Oracle database for tables with specific column names?

The data you want is in the "cols" meta-data table:


This one will give you a list of tables that have all of the columns you want:

select distinct
  cols c1
  inner join
  cols c2
  inner join
  cols c3
  inner join
  cols c4
  inner join
  tab t
where T.TABTYPE = 'TABLE' --could be 'VIEW' if you wanted
  and upper(C1.COLUMN_NAME) like upper('%id%')
  and upper(C2.COLUMN_NAME) like upper('%fname%')
  and upper(C3.COLUMN_NAME) like upper('%lname%')
  and upper(C4.COLUMN_NAME) like upper('%address%')  

To do this in a different schema, just specify the schema in front of the table, as in


If you want to combine the searches of many schemas into one output result, then you could do this:


how to open .mat file without using MATLAB?

A .mat-file is a compressed binary file. It is not possible to open it with a text editor (except you have a special plugin as Dennis Jaheruddin says). Otherwise you will have to convert it into a text file (csv for example) with a script. This could be done by python for example: Read .mat files in Python.

Java JDBC - How to connect to Oracle using Service Name instead of SID

So there are two easy ways to make this work. The solution posted by Bert F works fine if you don't need to supply any other special Oracle-specific connection properties. The format for that is:


However, if you need to supply other Oracle-specific connection properties then you need to use the long TNSNAMES style. I had to do this recently to enable Oracle shared connections (where the server does its own connection pooling). The TNS format is:


If you're familiar with the Oracle TNSNAMES file format, then this should look familiar to you. If not then just Google it for the details.

How do I delete multiple rows in Entity Framework (without foreach)

See the answer 'favorite bit of code' that works

Here is how I used it:

     // Delete all rows from the WebLog table via the EF database context object
    // using a where clause that returns an IEnumerable typed list WebLog class 
    public IEnumerable<WebLog> DeleteAllWebLogEntries()
        IEnumerable<WebLog> myEntities = context.WebLog.Where(e => e.WebLog_ID > 0);

        return myEntities;

How to get ° character in a string in python?

Above answers assume that UTF8 encoding can safely be used - this one is specifically targetted for Windows.

The Windows console normaly uses CP850 encoding and not utf-8, so if you try to use a source file utf8-encoded, you get those 2 (incorrect) characters instead of a degree °.

Demonstration (using python 2.7 in a windows console):

deg = u'\xb0`  # utf code for degree
print deg.encode('utf8')

effectively outputs .

Fix: just force the correct encoding (or better use unicode):

local_encoding = 'cp850'    # adapt for other encodings
deg = u'\xb0'.encode(local_encoding)
print deg

or if you use a source file that explicitely defines an encoding:

# -*- coding: utf-8 -*-
local_encoding = 'cp850'  # adapt for other encodings
print " The current temperature in the country/city you've entered is " + temp_in_county_or_city + "°C.".decode('utf8').encode(local_encoding)

how to configure apache server to talk to HTTPS backend server?

In my case, my server was configured to work only in https mode, and error occured when I try to access http mode. So changing http://my-service to https://my-service helped.

how can I connect to a remote mongo server from Mac OS terminal

Another way to do this is:

mongo mongodb://mongoDbIPorDomain:port

Nginx - Customizing 404 page

These answers are no longer recommended since try_files works faster than if in this context. Simply add try_files in your php location block to test if the file exists, otherwise return a 404.

location ~ \.php {
    try_files $uri =404;

Left function in c#

var value = fac.GetCachedValue("Auto Print Clinical Warnings")
// 0 = Start at the first character
// 1 = The length of the string to grab
if (value.ToLower().SubString(0, 1) == "y")
    // Do your stuff.

How to add many functions in ONE ng-click?

Try this:

  • Make a collection of functions
  • Make a function that loops through and executes all the functions in the collection.
  • Add the function to the html
array = [
    function() {},
    function() {},
    function() {}

function loop() {
    array.forEach(item) {

ng - click = "loop()"

Convert char to int in C#

Has anyone considered using int.Parse() and int.TryParse() like this

int bar = int.Parse(foo.ToString());

Even better like this

int bar;
if (!int.TryParse(foo.ToString(), out bar))
    //Do something to correct the problem

It's a lot safer and less error prone

Move textfield when keyboard appears swift

Here is my version for a solution for Swift 2.2:

First register for Keyboard Show/Hide Notifications

                                                 selector: #selector(MessageThreadVC.keyboardWillShow(_:)),
                                                 name: UIKeyboardWillShowNotification,
                                                 object: nil)
                                                 selector: #selector(MessageThreadVC.keyboardWillHide(_:)),
                                                 name: UIKeyboardWillHideNotification,
                                                 object: nil)

Then in methods coresponding for those notifications move the main view up or down

func keyboardWillShow(sender: NSNotification) {
if let keyboardSize = (sender.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue() {
  self.view.frame.origin.y = -keyboardSize.height

func keyboardWillHide(sender: NSNotification) {
self.view.frame.origin.y = 0

The trick is in the "keyboardWillShow" part which get calls every time "QuickType Suggestion Bar" is expanded or collapsed. Then we always set the y coordinate of the main view which equals the negative value of total keyboard height (with or without the "QuickType bar" portion).

At the end do not forget to remove observers

deinit {